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TOMOYO Linux Cross Reference
Linux/lib/Kconfig.debug

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

Diff markup

Differences between /lib/Kconfig.debug (Architecture i386) and /lib/Kconfig.debug (Architecture alpha)


  1 # SPDX-License-Identifier: GPL-2.0-only             1 # SPDX-License-Identifier: GPL-2.0-only
  2 menu "Kernel hacking"                               2 menu "Kernel hacking"
  3                                                     3 
  4 menu "printk and dmesg options"                     4 menu "printk and dmesg options"
  5                                                     5 
  6 config PRINTK_TIME                                  6 config PRINTK_TIME
  7         bool "Show timing information on print      7         bool "Show timing information on printks"
  8         depends on PRINTK                           8         depends on PRINTK
  9         help                                        9         help
 10           Selecting this option causes time st     10           Selecting this option causes time stamps of the printk()
 11           messages to be added to the output o     11           messages to be added to the output of the syslog() system
 12           call and at the console.                 12           call and at the console.
 13                                                    13 
 14           The timestamp is always recorded int     14           The timestamp is always recorded internally, and exported
 15           to /dev/kmsg. This flag just specifi     15           to /dev/kmsg. This flag just specifies if the timestamp should
 16           be included, not that the timestamp      16           be included, not that the timestamp is recorded.
 17                                                    17 
 18           The behavior is also controlled by t     18           The behavior is also controlled by the kernel command line
 19           parameter printk.time=1. See Documen     19           parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
 20                                                    20 
 21 config PRINTK_CALLER                               21 config PRINTK_CALLER
 22         bool "Show caller information on print     22         bool "Show caller information on printks"
 23         depends on PRINTK                          23         depends on PRINTK
 24         help                                       24         help
 25           Selecting this option causes printk(     25           Selecting this option causes printk() to add a caller "thread id" (if
 26           in task context) or a caller "proces     26           in task context) or a caller "processor id" (if not in task context)
 27           to every message.                        27           to every message.
 28                                                    28 
 29           This option is intended for environm     29           This option is intended for environments where multiple threads
 30           concurrently call printk() for many      30           concurrently call printk() for many times, for it is difficult to
 31           interpret without knowing where thes     31           interpret without knowing where these lines (or sometimes individual
 32           line which was divided into multiple     32           line which was divided into multiple lines due to race) came from.
 33                                                    33 
 34           Since toggling after boot makes the      34           Since toggling after boot makes the code racy, currently there is
 35           no option to enable/disable at the k     35           no option to enable/disable at the kernel command line parameter or
 36           sysfs interface.                         36           sysfs interface.
 37                                                    37 
 38 config STACKTRACE_BUILD_ID                         38 config STACKTRACE_BUILD_ID
 39         bool "Show build ID information in sta     39         bool "Show build ID information in stacktraces"
 40         depends on PRINTK                          40         depends on PRINTK
 41         help                                       41         help
 42           Selecting this option adds build ID      42           Selecting this option adds build ID information for symbols in
 43           stacktraces printed with the printk      43           stacktraces printed with the printk format '%p[SR]b'.
 44                                                    44 
 45           This option is intended for distros      45           This option is intended for distros where debuginfo is not easily
 46           accessible but can be downloaded giv     46           accessible but can be downloaded given the build ID of the vmlinux or
 47           kernel module where the function is      47           kernel module where the function is located.
 48                                                    48 
 49 config CONSOLE_LOGLEVEL_DEFAULT                    49 config CONSOLE_LOGLEVEL_DEFAULT
 50         int "Default console loglevel (1-15)"      50         int "Default console loglevel (1-15)"
 51         range 1 15                                 51         range 1 15
 52         default "7"                                52         default "7"
 53         help                                       53         help
 54           Default loglevel to determine what w     54           Default loglevel to determine what will be printed on the console.
 55                                                    55 
 56           Setting a default here is equivalent     56           Setting a default here is equivalent to passing in loglevel=<x> in
 57           the kernel bootargs. loglevel=<x> co     57           the kernel bootargs. loglevel=<x> continues to override whatever
 58           value is specified here as well.         58           value is specified here as well.
 59                                                    59 
 60           Note: This does not affect the log l     60           Note: This does not affect the log level of un-prefixed printk()
 61           usage in the kernel. That is control     61           usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
 62           option.                                  62           option.
 63                                                    63 
 64 config CONSOLE_LOGLEVEL_QUIET                      64 config CONSOLE_LOGLEVEL_QUIET
 65         int "quiet console loglevel (1-15)"        65         int "quiet console loglevel (1-15)"
 66         range 1 15                                 66         range 1 15
 67         default "4"                                67         default "4"
 68         help                                       68         help
 69           loglevel to use when "quiet" is pass     69           loglevel to use when "quiet" is passed on the kernel commandline.
 70                                                    70 
 71           When "quiet" is passed on the kernel     71           When "quiet" is passed on the kernel commandline this loglevel
 72           will be used as the loglevel. IOW pa     72           will be used as the loglevel. IOW passing "quiet" will be the
 73           equivalent of passing "loglevel=<CON     73           equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
 74                                                    74 
 75 config MESSAGE_LOGLEVEL_DEFAULT                    75 config MESSAGE_LOGLEVEL_DEFAULT
 76         int "Default message log level (1-7)"      76         int "Default message log level (1-7)"
 77         range 1 7                                  77         range 1 7
 78         default "4"                                78         default "4"
 79         help                                       79         help
 80           Default log level for printk stateme     80           Default log level for printk statements with no specified priority.
 81                                                    81 
 82           This was hard-coded to KERN_WARNING      82           This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
 83           that are auditing their logs closely     83           that are auditing their logs closely may want to set it to a lower
 84           priority.                                84           priority.
 85                                                    85 
 86           Note: This does not affect what mess     86           Note: This does not affect what message level gets printed on the console
 87           by default. To change that, use logl     87           by default. To change that, use loglevel=<x> in the kernel bootargs,
 88           or pick a different CONSOLE_LOGLEVEL     88           or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
 89                                                    89 
 90 config BOOT_PRINTK_DELAY                           90 config BOOT_PRINTK_DELAY
 91         bool "Delay each boot printk message b     91         bool "Delay each boot printk message by N milliseconds"
 92         depends on DEBUG_KERNEL && PRINTK && G     92         depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 93         help                                       93         help
 94           This build option allows you to read     94           This build option allows you to read kernel boot messages
 95           by inserting a short delay after eac     95           by inserting a short delay after each one.  The delay is
 96           specified in milliseconds on the ker     96           specified in milliseconds on the kernel command line,
 97           using "boot_delay=N".                    97           using "boot_delay=N".
 98                                                    98 
 99           It is likely that you would also nee     99           It is likely that you would also need to use "lpj=M" to preset
100           the "loops per jiffie" value.           100           the "loops per jiffie" value.
101           See a previous boot log for the "lpj    101           See a previous boot log for the "lpj" value to use for your
102           system, and then set "lpj=M" before     102           system, and then set "lpj=M" before setting "boot_delay=N".
103           NOTE:  Using this option may adverse    103           NOTE:  Using this option may adversely affect SMP systems.
104           I.e., processors other than the firs    104           I.e., processors other than the first one may not boot up.
105           BOOT_PRINTK_DELAY also may cause LOC    105           BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106           what it believes to be lockup condit    106           what it believes to be lockup conditions.
107                                                   107 
108 config DYNAMIC_DEBUG                              108 config DYNAMIC_DEBUG
109         bool "Enable dynamic printk() support"    109         bool "Enable dynamic printk() support"
110         default n                                 110         default n
111         depends on PRINTK                         111         depends on PRINTK
112         depends on (DEBUG_FS || PROC_FS)          112         depends on (DEBUG_FS || PROC_FS)
113         select DYNAMIC_DEBUG_CORE                 113         select DYNAMIC_DEBUG_CORE
114         help                                      114         help
115                                                   115 
116           Compiles debug level messages into t    116           Compiles debug level messages into the kernel, which would not
117           otherwise be available at runtime. T    117           otherwise be available at runtime. These messages can then be
118           enabled/disabled based on various le    118           enabled/disabled based on various levels of scope - per source file,
119           function, module, format string, and    119           function, module, format string, and line number. This mechanism
120           implicitly compiles in all pr_debug(    120           implicitly compiles in all pr_debug() and dev_dbg() calls, which
121           enlarges the kernel text size by abo    121           enlarges the kernel text size by about 2%.
122                                                   122 
123           If a source file is compiled with DE    123           If a source file is compiled with DEBUG flag set, any
124           pr_debug() calls in it are enabled b    124           pr_debug() calls in it are enabled by default, but can be
125           disabled at runtime as below.  Note     125           disabled at runtime as below.  Note that DEBUG flag is
126           turned on by many CONFIG_*DEBUG* opt    126           turned on by many CONFIG_*DEBUG* options.
127                                                   127 
128           Usage:                                  128           Usage:
129                                                   129 
130           Dynamic debugging is controlled via     130           Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131           which is contained in the 'debugfs'     131           which is contained in the 'debugfs' filesystem or procfs.
132           Thus, the debugfs or procfs filesyst    132           Thus, the debugfs or procfs filesystem must first be mounted before
133           making use of this feature.             133           making use of this feature.
134           We refer the control file as: <debug    134           We refer the control file as: <debugfs>/dynamic_debug/control. This
135           file contains a list of the debug st    135           file contains a list of the debug statements that can be enabled. The
136           format for each line of the file is:    136           format for each line of the file is:
137                                                   137 
138                 filename:lineno [module]functi    138                 filename:lineno [module]function flags format
139                                                   139 
140           filename : source file of the debug     140           filename : source file of the debug statement
141           lineno : line number of the debug st    141           lineno : line number of the debug statement
142           module : module that contains the de    142           module : module that contains the debug statement
143           function : function that contains th    143           function : function that contains the debug statement
144           flags : '=p' means the line is turne    144           flags : '=p' means the line is turned 'on' for printing
145           format : the format used for the deb    145           format : the format used for the debug statement
146                                                   146 
147           From a live system:                     147           From a live system:
148                                                   148 
149                 nullarbor:~ # cat <debugfs>/dy    149                 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150                 # filename:lineno [module]func    150                 # filename:lineno [module]function flags format
151                 fs/aio.c:222 [aio]__put_ioctx     151                 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152                 fs/aio.c:248 [aio]ioctx_alloc     152                 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153                 fs/aio.c:1770 [aio]sys_io_canc    153                 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154                                                   154 
155           Example usage:                          155           Example usage:
156                                                   156 
157                 // enable the message at line     157                 // enable the message at line 1603 of file svcsock.c
158                 nullarbor:~ # echo -n 'file sv    158                 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159                                                   159                                                 <debugfs>/dynamic_debug/control
160                                                   160 
161                 // enable all the messages in     161                 // enable all the messages in file svcsock.c
162                 nullarbor:~ # echo -n 'file sv    162                 nullarbor:~ # echo -n 'file svcsock.c +p' >
163                                                   163                                                 <debugfs>/dynamic_debug/control
164                                                   164 
165                 // enable all the messages in     165                 // enable all the messages in the NFS server module
166                 nullarbor:~ # echo -n 'module     166                 nullarbor:~ # echo -n 'module nfsd +p' >
167                                                   167                                                 <debugfs>/dynamic_debug/control
168                                                   168 
169                 // enable all 12 messages in t    169                 // enable all 12 messages in the function svc_process()
170                 nullarbor:~ # echo -n 'func sv    170                 nullarbor:~ # echo -n 'func svc_process +p' >
171                                                   171                                                 <debugfs>/dynamic_debug/control
172                                                   172 
173                 // disable all 12 messages in     173                 // disable all 12 messages in the function svc_process()
174                 nullarbor:~ # echo -n 'func sv    174                 nullarbor:~ # echo -n 'func svc_process -p' >
175                                                   175                                                 <debugfs>/dynamic_debug/control
176                                                   176 
177           See Documentation/admin-guide/dynami    177           See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178           information.                            178           information.
179                                                   179 
180 config DYNAMIC_DEBUG_CORE                         180 config DYNAMIC_DEBUG_CORE
181         bool "Enable core function of dynamic     181         bool "Enable core function of dynamic debug support"
182         depends on PRINTK                         182         depends on PRINTK
183         depends on (DEBUG_FS || PROC_FS)          183         depends on (DEBUG_FS || PROC_FS)
184         help                                      184         help
185           Enable core functional support of dy    185           Enable core functional support of dynamic debug. It is useful
186           when you want to tie dynamic debug t    186           when you want to tie dynamic debug to your kernel modules with
187           DYNAMIC_DEBUG_MODULE defined for eac    187           DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188           the case of embedded system where th    188           the case of embedded system where the kernel image size is
189           sensitive for people.                   189           sensitive for people.
190                                                   190 
191 config SYMBOLIC_ERRNAME                           191 config SYMBOLIC_ERRNAME
192         bool "Support symbolic error names in     192         bool "Support symbolic error names in printf"
193         default y if PRINTK                       193         default y if PRINTK
194         help                                      194         help
195           If you say Y here, the kernel's prin    195           If you say Y here, the kernel's printf implementation will
196           be able to print symbolic error name    196           be able to print symbolic error names such as ENOSPC instead
197           of the number 28. It makes the kerne    197           of the number 28. It makes the kernel image slightly larger
198           (about 3KB), but can make the kernel    198           (about 3KB), but can make the kernel logs easier to read.
199                                                   199 
200 config DEBUG_BUGVERBOSE                           200 config DEBUG_BUGVERBOSE
201         bool "Verbose BUG() reporting (adds 70    201         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202         depends on BUG && (GENERIC_BUG || HAVE    202         depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203         default y                                 203         default y
204         help                                      204         help
205           Say Y here to make BUG() panics outp    205           Say Y here to make BUG() panics output the file name and line number
206           of the BUG call as well as the EIP a    206           of the BUG call as well as the EIP and oops trace.  This aids
207           debugging but costs about 70-100K of    207           debugging but costs about 70-100K of memory.
208                                                   208 
209 endmenu # "printk and dmesg options"              209 endmenu # "printk and dmesg options"
210                                                   210 
211 config DEBUG_KERNEL                               211 config DEBUG_KERNEL
212         bool "Kernel debugging"                   212         bool "Kernel debugging"
213         help                                      213         help
214           Say Y here if you are developing dri    214           Say Y here if you are developing drivers or trying to debug and
215           identify kernel problems.               215           identify kernel problems.
216                                                   216 
217 config DEBUG_MISC                                 217 config DEBUG_MISC
218         bool "Miscellaneous debug code"           218         bool "Miscellaneous debug code"
219         default DEBUG_KERNEL                      219         default DEBUG_KERNEL
220         depends on DEBUG_KERNEL                   220         depends on DEBUG_KERNEL
221         help                                      221         help
222           Say Y here if you need to enable mis    222           Say Y here if you need to enable miscellaneous debug code that should
223           be under a more specific debug optio    223           be under a more specific debug option but isn't.
224                                                   224 
225 menu "Compile-time checks and compiler options    225 menu "Compile-time checks and compiler options"
226                                                   226 
227 config DEBUG_INFO                                 227 config DEBUG_INFO
228         bool                                      228         bool
229         help                                      229         help
230           A kernel debug info option other tha    230           A kernel debug info option other than "None" has been selected
231           in the "Debug information" choice be    231           in the "Debug information" choice below, indicating that debug
232           information will be generated for bu    232           information will be generated for build targets.
233                                                   233 
234 # Clang generates .uleb128 with label differen    234 # Clang generates .uleb128 with label differences for DWARF v5, a feature that
235 # older binutils ports do not support when uti    235 # older binutils ports do not support when utilizing RISC-V style linker
236 # relaxation: https://sourceware.org/bugzilla/    236 # relaxation: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
237 config AS_HAS_NON_CONST_ULEB128                   237 config AS_HAS_NON_CONST_ULEB128
238         def_bool $(as-instr,.uleb128 .Lexpr_en    238         def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
239                                                   239 
240 choice                                            240 choice
241         prompt "Debug information"                241         prompt "Debug information"
242         depends on DEBUG_KERNEL                   242         depends on DEBUG_KERNEL
243         help                                      243         help
244           Selecting something other than "None    244           Selecting something other than "None" results in a kernel image
245           that will include debugging info res    245           that will include debugging info resulting in a larger kernel image.
246           This adds debug symbols to the kerne    246           This adds debug symbols to the kernel and modules (gcc -g), and
247           is needed if you intend to use kerne    247           is needed if you intend to use kernel crashdump or binary object
248           tools like crash, kgdb, LKCD, gdb, e    248           tools like crash, kgdb, LKCD, gdb, etc on the kernel.
249                                                   249 
250           Choose which version of DWARF debug     250           Choose which version of DWARF debug info to emit. If unsure,
251           select "Toolchain default".             251           select "Toolchain default".
252                                                   252 
253 config DEBUG_INFO_NONE                            253 config DEBUG_INFO_NONE
254         bool "Disable debug information"          254         bool "Disable debug information"
255         help                                      255         help
256           Do not build the kernel with debuggi    256           Do not build the kernel with debugging information, which will
257           result in a faster and smaller build    257           result in a faster and smaller build.
258                                                   258 
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT         259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
260         bool "Rely on the toolchain's implicit    260         bool "Rely on the toolchain's implicit default DWARF version"
261         select DEBUG_INFO                         261         select DEBUG_INFO
262         depends on !CC_IS_CLANG || AS_IS_LLVM     262         depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
263         help                                      263         help
264           The implicit default version of DWAR    264           The implicit default version of DWARF debug info produced by a
265           toolchain changes over time.            265           toolchain changes over time.
266                                                   266 
267           This can break consumers of the debu    267           This can break consumers of the debug info that haven't upgraded to
268           support newer revisions, and prevent    268           support newer revisions, and prevent testing newer versions, but
269           those should be less common scenario    269           those should be less common scenarios.
270                                                   270 
271 config DEBUG_INFO_DWARF4                          271 config DEBUG_INFO_DWARF4
272         bool "Generate DWARF Version 4 debugin    272         bool "Generate DWARF Version 4 debuginfo"
273         select DEBUG_INFO                         273         select DEBUG_INFO
274         depends on !CC_IS_CLANG || AS_IS_LLVM     274         depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
275         help                                      275         help
276           Generate DWARF v4 debug info. This r    276           Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
277           if using clang without clang's integ    277           if using clang without clang's integrated assembler, and gdb 7.0+.
278                                                   278 
279           If you have consumers of DWARF debug    279           If you have consumers of DWARF debug info that are not ready for
280           newer revisions of DWARF, you may wi    280           newer revisions of DWARF, you may wish to choose this or have your
281           config select this.                     281           config select this.
282                                                   282 
283 config DEBUG_INFO_DWARF5                          283 config DEBUG_INFO_DWARF5
284         bool "Generate DWARF Version 5 debugin    284         bool "Generate DWARF Version 5 debuginfo"
285         select DEBUG_INFO                         285         select DEBUG_INFO
286         depends on !ARCH_HAS_BROKEN_DWARF5        286         depends on !ARCH_HAS_BROKEN_DWARF5
287         depends on !CC_IS_CLANG || AS_IS_LLVM     287         depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
288         help                                      288         help
289           Generate DWARF v5 debug info. Requir    289           Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
290           5.0+ accepts the -gdwarf-5 flag but     290           5.0+ accepts the -gdwarf-5 flag but only had partial support for some
291           draft features until 7.0), and gdb 8    291           draft features until 7.0), and gdb 8.0+.
292                                                   292 
293           Changes to the structure of debug in    293           Changes to the structure of debug info in Version 5 allow for around
294           15-18% savings in resulting image an    294           15-18% savings in resulting image and debug info section sizes as
295           compared to DWARF Version 4. DWARF V    295           compared to DWARF Version 4. DWARF Version 5 standardizes previous
296           extensions such as accelerators for     296           extensions such as accelerators for symbol indexing and the format
297           for fission (.dwo/.dwp) files. Users    297           for fission (.dwo/.dwp) files. Users may not want to select this
298           config if they rely on tooling that     298           config if they rely on tooling that has not yet been updated to
299           support DWARF Version 5.                299           support DWARF Version 5.
300                                                   300 
301 endchoice # "Debug information"                   301 endchoice # "Debug information"
302                                                   302 
303 if DEBUG_INFO                                     303 if DEBUG_INFO
304                                                   304 
305 config DEBUG_INFO_REDUCED                         305 config DEBUG_INFO_REDUCED
306         bool "Reduce debugging information"       306         bool "Reduce debugging information"
307         help                                      307         help
308           If you say Y here gcc is instructed     308           If you say Y here gcc is instructed to generate less debugging
309           information for structure types. Thi    309           information for structure types. This means that tools that
310           need full debugging information (lik    310           need full debugging information (like kgdb or systemtap) won't
311           be happy. But if you merely need deb    311           be happy. But if you merely need debugging information to
312           resolve line numbers there is no los    312           resolve line numbers there is no loss. Advantage is that
313           build directory object sizes shrink     313           build directory object sizes shrink dramatically over a full
314           DEBUG_INFO build and compile times a    314           DEBUG_INFO build and compile times are reduced too.
315           Only works with newer gcc versions.     315           Only works with newer gcc versions.
316                                                   316 
317 choice                                            317 choice
318         prompt "Compressed Debug information"     318         prompt "Compressed Debug information"
319         help                                      319         help
320           Compress the resulting debug info. R    320           Compress the resulting debug info. Results in smaller debug info sections,
321           but requires that consumers are able    321           but requires that consumers are able to decompress the results.
322                                                   322 
323           If unsure, choose DEBUG_INFO_COMPRES    323           If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
324                                                   324 
325 config DEBUG_INFO_COMPRESSED_NONE                 325 config DEBUG_INFO_COMPRESSED_NONE
326         bool "Don't compress debug information    326         bool "Don't compress debug information"
327         help                                      327         help
328           Don't compress debug info sections.     328           Don't compress debug info sections.
329                                                   329 
330 config DEBUG_INFO_COMPRESSED_ZLIB                 330 config DEBUG_INFO_COMPRESSED_ZLIB
331         bool "Compress debugging information w    331         bool "Compress debugging information with zlib"
332         depends on $(cc-option,-gz=zlib)          332         depends on $(cc-option,-gz=zlib)
333         depends on $(ld-option,--compress-debu    333         depends on $(ld-option,--compress-debug-sections=zlib)
334         help                                      334         help
335           Compress the debug information using    335           Compress the debug information using zlib.  Requires GCC 5.0+ or Clang
336           5.0+, binutils 2.26+, and zlib.         336           5.0+, binutils 2.26+, and zlib.
337                                                   337 
338           Users of dpkg-deb via scripts/packag    338           Users of dpkg-deb via scripts/package/builddeb may find an increase in
339           size of their debug .deb packages wi    339           size of their debug .deb packages with this config set, due to the
340           debug info being compressed with zli    340           debug info being compressed with zlib, then the object files being
341           recompressed with a different compre    341           recompressed with a different compression scheme. But this is still
342           preferable to setting $KDEB_COMPRESS    342           preferable to setting $KDEB_COMPRESS to "none" which would be even
343           larger.                                 343           larger.
344                                                   344 
345 config DEBUG_INFO_COMPRESSED_ZSTD                 345 config DEBUG_INFO_COMPRESSED_ZSTD
346         bool "Compress debugging information w    346         bool "Compress debugging information with zstd"
347         depends on $(cc-option,-gz=zstd)          347         depends on $(cc-option,-gz=zstd)
348         depends on $(ld-option,--compress-debu    348         depends on $(ld-option,--compress-debug-sections=zstd)
349         help                                      349         help
350           Compress the debug information using    350           Compress the debug information using zstd.  This may provide better
351           compression than zlib, for about the    351           compression than zlib, for about the same time costs, but requires newer
352           toolchain support.  Requires GCC 13.    352           toolchain support.  Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
353           zstd.                                   353           zstd.
354                                                   354 
355 endchoice # "Compressed Debug information"        355 endchoice # "Compressed Debug information"
356                                                   356 
357 config DEBUG_INFO_SPLIT                           357 config DEBUG_INFO_SPLIT
358         bool "Produce split debuginfo in .dwo     358         bool "Produce split debuginfo in .dwo files"
359         depends on $(cc-option,-gsplit-dwarf)     359         depends on $(cc-option,-gsplit-dwarf)
360         # RISC-V linker relaxation + -gsplit-d    360         # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
361         # prior to 12.x:                          361         # prior to 12.x:
362         # https://github.com/llvm/llvm-project    362         # https://github.com/llvm/llvm-project/issues/56642
363         # https://gcc.gnu.org/bugzilla/show_bu    363         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
364         depends on !RISCV || GCC_VERSION >= 12    364         depends on !RISCV || GCC_VERSION >= 120000
365         help                                      365         help
366           Generate debug info into separate .d    366           Generate debug info into separate .dwo files. This significantly
367           reduces the build directory size for    367           reduces the build directory size for builds with DEBUG_INFO,
368           because it stores the information on    368           because it stores the information only once on disk in .dwo
369           files instead of multiple times in o    369           files instead of multiple times in object files and executables.
370           In addition the debug information is    370           In addition the debug information is also compressed.
371                                                   371 
372           Requires recent gcc (4.7+) and recen    372           Requires recent gcc (4.7+) and recent gdb/binutils.
373           Any tool that packages or reads debu    373           Any tool that packages or reads debug information would need
374           to know about the .dwo files and inc    374           to know about the .dwo files and include them.
375           Incompatible with older versions of     375           Incompatible with older versions of ccache.
376                                                   376 
377 config DEBUG_INFO_BTF                             377 config DEBUG_INFO_BTF
378         bool "Generate BTF type information"      378         bool "Generate BTF type information"
379         depends on !DEBUG_INFO_SPLIT && !DEBUG    379         depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380         depends on !GCC_PLUGIN_RANDSTRUCT || C    380         depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
381         depends on BPF_SYSCALL                    381         depends on BPF_SYSCALL
382         depends on !DEBUG_INFO_DWARF5 || PAHOL    382         depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
383         # pahole uses elfutils, which does not    383         # pahole uses elfutils, which does not have support for Hexagon relocations
384         depends on !HEXAGON                       384         depends on !HEXAGON
385         help                                      385         help
386           Generate deduplicated BTF type infor    386           Generate deduplicated BTF type information from DWARF debug info.
387           Turning this on expects presence of     387           Turning this on expects presence of pahole tool, which will convert
388           DWARF type info into equivalent dedu    388           DWARF type info into equivalent deduplicated BTF type info.
389                                                   389 
390 config PAHOLE_HAS_SPLIT_BTF                       390 config PAHOLE_HAS_SPLIT_BTF
391         def_bool PAHOLE_VERSION >= 119            391         def_bool PAHOLE_VERSION >= 119
392                                                   392 
393 config PAHOLE_HAS_BTF_TAG                         393 config PAHOLE_HAS_BTF_TAG
394         def_bool PAHOLE_VERSION >= 123            394         def_bool PAHOLE_VERSION >= 123
395         depends on CC_IS_CLANG                    395         depends on CC_IS_CLANG
396         help                                      396         help
397           Decide whether pahole emits btf_tag     397           Decide whether pahole emits btf_tag attributes (btf_type_tag and
398           btf_decl_tag) or not. Currently only    398           btf_decl_tag) or not. Currently only clang compiler implements
399           these attributes, so make the config    399           these attributes, so make the config depend on CC_IS_CLANG.
400                                                   400 
401 config PAHOLE_HAS_LANG_EXCLUDE                    401 config PAHOLE_HAS_LANG_EXCLUDE
402         def_bool PAHOLE_VERSION >= 124            402         def_bool PAHOLE_VERSION >= 124
403         help                                      403         help
404           Support for the --lang_exclude flag     404           Support for the --lang_exclude flag which makes pahole exclude
405           compilation units from the supplied     405           compilation units from the supplied language. Used in Kbuild to
406           omit Rust CUs which are not supporte    406           omit Rust CUs which are not supported in version 1.24 of pahole,
407           otherwise it would emit malformed ke    407           otherwise it would emit malformed kernel and module binaries when
408           using DEBUG_INFO_BTF_MODULES.           408           using DEBUG_INFO_BTF_MODULES.
409                                                   409 
410 config DEBUG_INFO_BTF_MODULES                     410 config DEBUG_INFO_BTF_MODULES
411         bool "Generate BTF type information fo    411         bool "Generate BTF type information for kernel modules"
412         default y                                 412         default y
413         depends on DEBUG_INFO_BTF && MODULES &    413         depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
414         help                                      414         help
415           Generate compact split BTF type info    415           Generate compact split BTF type information for kernel modules.
416                                                   416 
417 config MODULE_ALLOW_BTF_MISMATCH                  417 config MODULE_ALLOW_BTF_MISMATCH
418         bool "Allow loading modules with non-m    418         bool "Allow loading modules with non-matching BTF type info"
419         depends on DEBUG_INFO_BTF_MODULES         419         depends on DEBUG_INFO_BTF_MODULES
420         help                                      420         help
421           For modules whose split BTF does not    421           For modules whose split BTF does not match vmlinux, load without
422           BTF rather than refusing to load. Th    422           BTF rather than refusing to load. The default behavior with
423           module BTF enabled is to reject modu    423           module BTF enabled is to reject modules with such mismatches;
424           this option will still load module B    424           this option will still load module BTF where possible but ignore
425           it when a mismatch is found.            425           it when a mismatch is found.
426                                                   426 
427 config GDB_SCRIPTS                                427 config GDB_SCRIPTS
428         bool "Provide GDB scripts for kernel d    428         bool "Provide GDB scripts for kernel debugging"
429         help                                      429         help
430           This creates the required links to G    430           This creates the required links to GDB helper scripts in the
431           build directory. If you load vmlinux    431           build directory. If you load vmlinux into gdb, the helper
432           scripts will be automatically import    432           scripts will be automatically imported by gdb as well, and
433           additional functions are available t    433           additional functions are available to analyze a Linux kernel
434           instance. See Documentation/dev-tool    434           instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435           for further details.                    435           for further details.
436                                                   436 
437 endif # DEBUG_INFO                                437 endif # DEBUG_INFO
438                                                   438 
439 config FRAME_WARN                                 439 config FRAME_WARN
440         int "Warn for stack frames larger than    440         int "Warn for stack frames larger than"
441         range 0 8192                              441         range 0 8192
442         default 0 if KMSAN                        442         default 0 if KMSAN
443         default 2048 if GCC_PLUGIN_LATENT_ENTR    443         default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444         default 2048 if PARISC                    444         default 2048 if PARISC
445         default 1536 if (!64BIT && XTENSA)        445         default 1536 if (!64BIT && XTENSA)
446         default 1280 if KASAN && !64BIT           446         default 1280 if KASAN && !64BIT
447         default 1024 if !64BIT                    447         default 1024 if !64BIT
448         default 2048 if 64BIT                     448         default 2048 if 64BIT
449         help                                      449         help
450           Tell the compiler to warn at build t    450           Tell the compiler to warn at build time for stack frames larger than this.
451           Setting this too low will cause a lo    451           Setting this too low will cause a lot of warnings.
452           Setting it to 0 disables the warning    452           Setting it to 0 disables the warning.
453                                                   453 
454 config STRIP_ASM_SYMS                             454 config STRIP_ASM_SYMS
455         bool "Strip assembler-generated symbol    455         bool "Strip assembler-generated symbols during link"
456         default n                                 456         default n
457         help                                      457         help
458           Strip internal assembler-generated s    458           Strip internal assembler-generated symbols during a link (symbols
459           that look like '.Lxxx') so they don'    459           that look like '.Lxxx') so they don't pollute the output of
460           get_wchan() and suchlike.               460           get_wchan() and suchlike.
461                                                   461 
462 config READABLE_ASM                               462 config READABLE_ASM
463         bool "Generate readable assembler code    463         bool "Generate readable assembler code"
464         depends on DEBUG_KERNEL                   464         depends on DEBUG_KERNEL
465         depends on CC_IS_GCC                      465         depends on CC_IS_GCC
466         help                                      466         help
467           Disable some compiler optimizations     467           Disable some compiler optimizations that tend to generate human unreadable
468           assembler output. This may make the     468           assembler output. This may make the kernel slightly slower, but it helps
469           to keep kernel developers who have t    469           to keep kernel developers who have to stare a lot at assembler listings
470           sane.                                   470           sane.
471                                                   471 
472 config HEADERS_INSTALL                            472 config HEADERS_INSTALL
473         bool "Install uapi headers to usr/incl    473         bool "Install uapi headers to usr/include"
474         depends on !UML                           474         depends on !UML
475         help                                      475         help
476           This option will install uapi header    476           This option will install uapi headers (headers exported to user-space)
477           into the usr/include directory for u    477           into the usr/include directory for use during the kernel build.
478           This is unneeded for building the ke    478           This is unneeded for building the kernel itself, but needed for some
479           user-space program samples. It is al    479           user-space program samples. It is also needed by some features such
480           as uapi header sanity checks.           480           as uapi header sanity checks.
481                                                   481 
482 config DEBUG_SECTION_MISMATCH                     482 config DEBUG_SECTION_MISMATCH
483         bool "Enable full Section mismatch ana    483         bool "Enable full Section mismatch analysis"
484         depends on CC_IS_GCC                      484         depends on CC_IS_GCC
485         help                                      485         help
486           The section mismatch analysis checks    486           The section mismatch analysis checks if there are illegal
487           references from one section to anoth    487           references from one section to another section.
488           During linktime or runtime, some sec    488           During linktime or runtime, some sections are dropped;
489           any use of code/data previously in t    489           any use of code/data previously in these sections would
490           most likely result in an oops.          490           most likely result in an oops.
491           In the code, functions and variables    491           In the code, functions and variables are annotated with
492           __init,, etc. (see the full list in     492           __init,, etc. (see the full list in include/linux/init.h),
493           which results in the code/data being    493           which results in the code/data being placed in specific sections.
494           The section mismatch analysis is alw    494           The section mismatch analysis is always performed after a full
495           kernel build, and enabling this opti    495           kernel build, and enabling this option causes the following
496           additional step to occur:               496           additional step to occur:
497           - Add the option -fno-inline-functio    497           - Add the option -fno-inline-functions-called-once to gcc commands.
498             When inlining a function annotated    498             When inlining a function annotated with __init in a non-init
499             function, we would lose the sectio    499             function, we would lose the section information and thus
500             the analysis would not catch the i    500             the analysis would not catch the illegal reference.
501             This option tells gcc to inline le    501             This option tells gcc to inline less (but it does result in
502             a larger kernel).                     502             a larger kernel).
503                                                   503 
504 config SECTION_MISMATCH_WARN_ONLY                 504 config SECTION_MISMATCH_WARN_ONLY
505         bool "Make section mismatch errors non    505         bool "Make section mismatch errors non-fatal"
506         default y                                 506         default y
507         help                                      507         help
508           If you say N here, the build process    508           If you say N here, the build process will fail if there are any
509           section mismatch, instead of just th    509           section mismatch, instead of just throwing warnings.
510                                                   510 
511           If unsure, say Y.                       511           If unsure, say Y.
512                                                   512 
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B             513 config DEBUG_FORCE_FUNCTION_ALIGN_64B
514         bool "Force all function address 64B a    514         bool "Force all function address 64B aligned"
515         depends on EXPERT && (X86_64 || ARM64     515         depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
516         select FUNCTION_ALIGNMENT_64B             516         select FUNCTION_ALIGNMENT_64B
517         help                                      517         help
518           There are cases that a commit from o    518           There are cases that a commit from one domain changes the function
519           address alignment of other domains,     519           address alignment of other domains, and cause magic performance
520           bump (regression or improvement). En    520           bump (regression or improvement). Enable this option will help to
521           verify if the bump is caused by func    521           verify if the bump is caused by function alignment changes, while
522           it will slightly increase the kernel    522           it will slightly increase the kernel size and affect icache usage.
523                                                   523 
524           It is mainly for debug and performan    524           It is mainly for debug and performance tuning use.
525                                                   525 
526 #                                                 526 #
527 # Select this config option from the architect    527 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers     528 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE    529 # option on the architecture (regardless of KERNEL_DEBUG):
530 #                                                 530 #
531 config ARCH_WANT_FRAME_POINTERS                   531 config ARCH_WANT_FRAME_POINTERS
532         bool                                      532         bool
533                                                   533 
534 config FRAME_POINTER                              534 config FRAME_POINTER
535         bool "Compile the kernel with frame po    535         bool "Compile the kernel with frame pointers"
536         depends on DEBUG_KERNEL && (M68K || UM    536         depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537         default y if (DEBUG_INFO && UML) || AR    537         default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538         help                                      538         help
539           If you say Y here the resulting kern    539           If you say Y here the resulting kernel image will be slightly
540           larger and slower, but it gives very    540           larger and slower, but it gives very useful debugging information
541           in case of kernel bugs. (precise oop    541           in case of kernel bugs. (precise oopses/stacktraces/warnings)
542                                                   542 
543 config OBJTOOL                                    543 config OBJTOOL
544         bool                                      544         bool
545                                                   545 
546 config STACK_VALIDATION                           546 config STACK_VALIDATION
547         bool "Compile-time stack metadata vali    547         bool "Compile-time stack metadata validation"
548         depends on HAVE_STACK_VALIDATION && UN    548         depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
549         select OBJTOOL                            549         select OBJTOOL
550         default n                                 550         default n
551         help                                      551         help
552           Validate frame pointer rules at comp    552           Validate frame pointer rules at compile-time.  This helps ensure that
553           runtime stack traces are more reliab    553           runtime stack traces are more reliable.
554                                                   554 
555           For more information, see               555           For more information, see
556           tools/objtool/Documentation/objtool.    556           tools/objtool/Documentation/objtool.txt.
557                                                   557 
558 config NOINSTR_VALIDATION                         558 config NOINSTR_VALIDATION
559         bool                                      559         bool
560         depends on HAVE_NOINSTR_VALIDATION &&     560         depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
561         select OBJTOOL                            561         select OBJTOOL
562         default y                                 562         default y
563                                                   563 
564 config VMLINUX_MAP                                564 config VMLINUX_MAP
565         bool "Generate vmlinux.map file when l    565         bool "Generate vmlinux.map file when linking"
566         depends on EXPERT                         566         depends on EXPERT
567         help                                      567         help
568           Selecting this option will pass "-Ma    568           Selecting this option will pass "-Map=vmlinux.map" to ld
569           when linking vmlinux. That file can     569           when linking vmlinux. That file can be useful for verifying
570           and debugging magic section games, a    570           and debugging magic section games, and for seeing which
571           pieces of code get eliminated with      571           pieces of code get eliminated with
572           CONFIG_LD_DEAD_CODE_DATA_ELIMINATION    572           CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
573                                                   573 
574 config DEBUG_FORCE_WEAK_PER_CPU                   574 config DEBUG_FORCE_WEAK_PER_CPU
575         bool "Force weak per-cpu definitions"     575         bool "Force weak per-cpu definitions"
576         depends on DEBUG_KERNEL                   576         depends on DEBUG_KERNEL
577         help                                      577         help
578           s390 and alpha require percpu variab    578           s390 and alpha require percpu variables in modules to be
579           defined weak to work around addressi    579           defined weak to work around addressing range issue which
580           puts the following two restrictions     580           puts the following two restrictions on percpu variable
581           definitions.                            581           definitions.
582                                                   582 
583           1. percpu symbols must be unique whe    583           1. percpu symbols must be unique whether static or not
584           2. percpu variables can't be defined    584           2. percpu variables can't be defined inside a function
585                                                   585 
586           To ensure that generic code follows     586           To ensure that generic code follows the above rules, this
587           option forces all percpu variables t    587           option forces all percpu variables to be defined as weak.
588                                                   588 
589 endmenu # "Compiler options"                      589 endmenu # "Compiler options"
590                                                   590 
591 menu "Generic Kernel Debugging Instruments"       591 menu "Generic Kernel Debugging Instruments"
592                                                   592 
593 config MAGIC_SYSRQ                                593 config MAGIC_SYSRQ
594         bool "Magic SysRq key"                    594         bool "Magic SysRq key"
595         depends on !UML                           595         depends on !UML
596         help                                      596         help
597           If you say Y here, you will have som    597           If you say Y here, you will have some control over the system even
598           if the system crashes for example du    598           if the system crashes for example during kernel debugging (e.g., you
599           will be able to flush the buffer cac    599           will be able to flush the buffer cache to disk, reboot the system
600           immediately or dump some status info    600           immediately or dump some status information). This is accomplished
601           by pressing various keys while holdi    601           by pressing various keys while holding SysRq (Alt+PrintScreen). It
602           also works on a serial console (on P    602           also works on a serial console (on PC hardware at least), if you
603           send a BREAK and then within 5 secon    603           send a BREAK and then within 5 seconds a command keypress. The
604           keys are documented in <file:Documen    604           keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605           Don't say Y unless you really know w    605           Don't say Y unless you really know what this hack does.
606                                                   606 
607 config MAGIC_SYSRQ_DEFAULT_ENABLE                 607 config MAGIC_SYSRQ_DEFAULT_ENABLE
608         hex "Enable magic SysRq key functions     608         hex "Enable magic SysRq key functions by default"
609         depends on MAGIC_SYSRQ                    609         depends on MAGIC_SYSRQ
610         default 0x1                               610         default 0x1
611         help                                      611         help
612           Specifies which SysRq key functions     612           Specifies which SysRq key functions are enabled by default.
613           This may be set to 1 or 0 to enable     613           This may be set to 1 or 0 to enable or disable them all, or
614           to a bitmask as described in Documen    614           to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615                                                   615 
616 config MAGIC_SYSRQ_SERIAL                         616 config MAGIC_SYSRQ_SERIAL
617         bool "Enable magic SysRq key over seri    617         bool "Enable magic SysRq key over serial"
618         depends on MAGIC_SYSRQ                    618         depends on MAGIC_SYSRQ
619         default y                                 619         default y
620         help                                      620         help
621           Many embedded boards have a disconne    621           Many embedded boards have a disconnected TTL level serial which can
622           generate some garbage that can lead     622           generate some garbage that can lead to spurious false sysrq detects.
623           This option allows you to decide whe    623           This option allows you to decide whether you want to enable the
624           magic SysRq key.                        624           magic SysRq key.
625                                                   625 
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE                626 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627         string "Char sequence that enables mag    627         string "Char sequence that enables magic SysRq over serial"
628         depends on MAGIC_SYSRQ_SERIAL             628         depends on MAGIC_SYSRQ_SERIAL
629         default ""                                629         default ""
630         help                                      630         help
631           Specifies a sequence of characters t    631           Specifies a sequence of characters that can follow BREAK to enable
632           SysRq on a serial console.              632           SysRq on a serial console.
633                                                   633 
634           If unsure, leave an empty string and    634           If unsure, leave an empty string and the option will not be enabled.
635                                                   635 
636 config DEBUG_FS                                   636 config DEBUG_FS
637         bool "Debug Filesystem"                   637         bool "Debug Filesystem"
638         help                                      638         help
639           debugfs is a virtual file system tha    639           debugfs is a virtual file system that kernel developers use to put
640           debugging files into.  Enable this o    640           debugging files into.  Enable this option to be able to read and
641           write to these files.                   641           write to these files.
642                                                   642 
643           For detailed documentation on the de    643           For detailed documentation on the debugfs API, see
644           Documentation/filesystems/.             644           Documentation/filesystems/.
645                                                   645 
646           If unsure, say N.                       646           If unsure, say N.
647                                                   647 
648 choice                                            648 choice
649         prompt "Debugfs default access"           649         prompt "Debugfs default access"
650         depends on DEBUG_FS                       650         depends on DEBUG_FS
651         default DEBUG_FS_ALLOW_ALL                651         default DEBUG_FS_ALLOW_ALL
652         help                                      652         help
653           This selects the default access rest    653           This selects the default access restrictions for debugfs.
654           It can be overridden with kernel com    654           It can be overridden with kernel command line option
655           debugfs=[on,no-mount,off]. The restr    655           debugfs=[on,no-mount,off]. The restrictions apply for API access
656           and filesystem registration.            656           and filesystem registration.
657                                                   657 
658 config DEBUG_FS_ALLOW_ALL                         658 config DEBUG_FS_ALLOW_ALL
659         bool "Access normal"                      659         bool "Access normal"
660         help                                      660         help
661           No restrictions apply. Both API and     661           No restrictions apply. Both API and filesystem registration
662           is on. This is the normal default op    662           is on. This is the normal default operation.
663                                                   663 
664 config DEBUG_FS_DISALLOW_MOUNT                    664 config DEBUG_FS_DISALLOW_MOUNT
665         bool "Do not register debugfs as files    665         bool "Do not register debugfs as filesystem"
666         help                                      666         help
667           The API is open but filesystem is no    667           The API is open but filesystem is not loaded. Clients can still do
668           their work and read with debug tools    668           their work and read with debug tools that do not need
669           debugfs filesystem.                     669           debugfs filesystem.
670                                                   670 
671 config DEBUG_FS_ALLOW_NONE                        671 config DEBUG_FS_ALLOW_NONE
672         bool "No access"                          672         bool "No access"
673         help                                      673         help
674           Access is off. Clients get -PERM whe    674           Access is off. Clients get -PERM when trying to create nodes in
675           debugfs tree and debugfs is not regi    675           debugfs tree and debugfs is not registered as a filesystem.
676           Client can then back-off or continue    676           Client can then back-off or continue without debugfs access.
677                                                   677 
678 endchoice                                         678 endchoice
679                                                   679 
680 source "lib/Kconfig.kgdb"                         680 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan"                        681 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan"                        682 source "lib/Kconfig.kcsan"
683                                                   683 
684 endmenu                                           684 endmenu
685                                                   685 
686 menu "Networking Debugging"                       686 menu "Networking Debugging"
687                                                   687 
688 source "net/Kconfig.debug"                        688 source "net/Kconfig.debug"
689                                                   689 
690 endmenu # "Networking Debugging"                  690 endmenu # "Networking Debugging"
691                                                   691 
692 menu "Memory Debugging"                           692 menu "Memory Debugging"
693                                                   693 
694 source "mm/Kconfig.debug"                         694 source "mm/Kconfig.debug"
695                                                   695 
696 config DEBUG_OBJECTS                              696 config DEBUG_OBJECTS
697         bool "Debug object operations"            697         bool "Debug object operations"
698         depends on DEBUG_KERNEL                   698         depends on DEBUG_KERNEL
699         help                                      699         help
700           If you say Y here, additional code w    700           If you say Y here, additional code will be inserted into the
701           kernel to track the life time of var    701           kernel to track the life time of various objects and validate
702           the operations on those objects.        702           the operations on those objects.
703                                                   703 
704 config DEBUG_OBJECTS_SELFTEST                     704 config DEBUG_OBJECTS_SELFTEST
705         bool "Debug objects selftest"             705         bool "Debug objects selftest"
706         depends on DEBUG_OBJECTS                  706         depends on DEBUG_OBJECTS
707         help                                      707         help
708           This enables the selftest of the obj    708           This enables the selftest of the object debug code.
709                                                   709 
710 config DEBUG_OBJECTS_FREE                         710 config DEBUG_OBJECTS_FREE
711         bool "Debug objects in freed memory"      711         bool "Debug objects in freed memory"
712         depends on DEBUG_OBJECTS                  712         depends on DEBUG_OBJECTS
713         help                                      713         help
714           This enables checks whether a k/v fr    714           This enables checks whether a k/v free operation frees an area
715           which contains an object which has n    715           which contains an object which has not been deactivated
716           properly. This can make kmalloc/kfre    716           properly. This can make kmalloc/kfree-intensive workloads
717           much slower.                            717           much slower.
718                                                   718 
719 config DEBUG_OBJECTS_TIMERS                       719 config DEBUG_OBJECTS_TIMERS
720         bool "Debug timer objects"                720         bool "Debug timer objects"
721         depends on DEBUG_OBJECTS                  721         depends on DEBUG_OBJECTS
722         help                                      722         help
723           If you say Y here, additional code w    723           If you say Y here, additional code will be inserted into the
724           timer routines to track the life tim    724           timer routines to track the life time of timer objects and
725           validate the timer operations.          725           validate the timer operations.
726                                                   726 
727 config DEBUG_OBJECTS_WORK                         727 config DEBUG_OBJECTS_WORK
728         bool "Debug work objects"                 728         bool "Debug work objects"
729         depends on DEBUG_OBJECTS                  729         depends on DEBUG_OBJECTS
730         help                                      730         help
731           If you say Y here, additional code w    731           If you say Y here, additional code will be inserted into the
732           work queue routines to track the lif    732           work queue routines to track the life time of work objects and
733           validate the work operations.           733           validate the work operations.
734                                                   734 
735 config DEBUG_OBJECTS_RCU_HEAD                     735 config DEBUG_OBJECTS_RCU_HEAD
736         bool "Debug RCU callbacks objects"        736         bool "Debug RCU callbacks objects"
737         depends on DEBUG_OBJECTS                  737         depends on DEBUG_OBJECTS
738         help                                      738         help
739           Enable this to turn on debugging of     739           Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740                                                   740 
741 config DEBUG_OBJECTS_PERCPU_COUNTER               741 config DEBUG_OBJECTS_PERCPU_COUNTER
742         bool "Debug percpu counter objects"       742         bool "Debug percpu counter objects"
743         depends on DEBUG_OBJECTS                  743         depends on DEBUG_OBJECTS
744         help                                      744         help
745           If you say Y here, additional code w    745           If you say Y here, additional code will be inserted into the
746           percpu counter routines to track the    746           percpu counter routines to track the life time of percpu counter
747           objects and validate the percpu coun    747           objects and validate the percpu counter operations.
748                                                   748 
749 config DEBUG_OBJECTS_ENABLE_DEFAULT               749 config DEBUG_OBJECTS_ENABLE_DEFAULT
750         int "debug_objects bootup default valu    750         int "debug_objects bootup default value (0-1)"
751         range 0 1                                 751         range 0 1
752         default "1"                               752         default "1"
753         depends on DEBUG_OBJECTS                  753         depends on DEBUG_OBJECTS
754         help                                      754         help
755           Debug objects boot parameter default    755           Debug objects boot parameter default value
756                                                   756 
757 config SHRINKER_DEBUG                             757 config SHRINKER_DEBUG
758         bool "Enable shrinker debugging suppor    758         bool "Enable shrinker debugging support"
759         depends on DEBUG_FS                       759         depends on DEBUG_FS
760         help                                      760         help
761           Say Y to enable the shrinker debugfs    761           Say Y to enable the shrinker debugfs interface which provides
762           visibility into the kernel memory sh    762           visibility into the kernel memory shrinkers subsystem.
763           Disable it to avoid an extra memory     763           Disable it to avoid an extra memory footprint.
764                                                   764 
765 config DEBUG_STACK_USAGE                          765 config DEBUG_STACK_USAGE
766         bool "Stack utilization instrumentatio    766         bool "Stack utilization instrumentation"
767         depends on DEBUG_KERNEL                   767         depends on DEBUG_KERNEL
768         help                                      768         help
769           Enables the display of the minimum a    769           Enables the display of the minimum amount of free stack which each
770           task has ever had available in the s    770           task has ever had available in the sysrq-T and sysrq-P debug output.
771           Also emits a message to dmesg when a    771           Also emits a message to dmesg when a process exits if that process
772           used more stack space than previousl    772           used more stack space than previously exiting processes.
773                                                   773 
774           This option will slow down process c    774           This option will slow down process creation somewhat.
775                                                   775 
776 config SCHED_STACK_END_CHECK                      776 config SCHED_STACK_END_CHECK
777         bool "Detect stack corruption on calls    777         bool "Detect stack corruption on calls to schedule()"
778         depends on DEBUG_KERNEL                   778         depends on DEBUG_KERNEL
779         default n                                 779         default n
780         help                                      780         help
781           This option checks for a stack overr    781           This option checks for a stack overrun on calls to schedule().
782           If the stack end location is found t    782           If the stack end location is found to be over written always panic as
783           the content of the corrupted region     783           the content of the corrupted region can no longer be trusted.
784           This is to ensure no erroneous behav    784           This is to ensure no erroneous behaviour occurs which could result in
785           data corruption or a sporadic crash     785           data corruption or a sporadic crash at a later stage once the region
786           is examined. The runtime overhead in    786           is examined. The runtime overhead introduced is minimal.
787                                                   787 
788 config ARCH_HAS_DEBUG_VM_PGTABLE                  788 config ARCH_HAS_DEBUG_VM_PGTABLE
789         bool                                      789         bool
790         help                                      790         help
791           An architecture should select this w    791           An architecture should select this when it can successfully
792           build and run DEBUG_VM_PGTABLE.         792           build and run DEBUG_VM_PGTABLE.
793                                                   793 
794 config DEBUG_VM_IRQSOFF                           794 config DEBUG_VM_IRQSOFF
795         def_bool DEBUG_VM && !PREEMPT_RT          795         def_bool DEBUG_VM && !PREEMPT_RT
796                                                   796 
797 config DEBUG_VM                                   797 config DEBUG_VM
798         bool "Debug VM"                           798         bool "Debug VM"
799         depends on DEBUG_KERNEL                   799         depends on DEBUG_KERNEL
800         help                                      800         help
801           Enable this to turn on extended chec    801           Enable this to turn on extended checks in the virtual-memory system
802           that may impact performance.            802           that may impact performance.
803                                                   803 
804           If unsure, say N.                       804           If unsure, say N.
805                                                   805 
806 config DEBUG_VM_SHOOT_LAZIES                      806 config DEBUG_VM_SHOOT_LAZIES
807         bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp    807         bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
808         depends on DEBUG_VM                       808         depends on DEBUG_VM
809         depends on MMU_LAZY_TLB_SHOOTDOWN         809         depends on MMU_LAZY_TLB_SHOOTDOWN
810         help                                      810         help
811           Enable additional IPIs that ensure l    811           Enable additional IPIs that ensure lazy tlb mm references are removed
812           before the mm is freed.                 812           before the mm is freed.
813                                                   813 
814           If unsure, say N.                       814           If unsure, say N.
815                                                   815 
816 config DEBUG_VM_MAPLE_TREE                        816 config DEBUG_VM_MAPLE_TREE
817         bool "Debug VM maple trees"               817         bool "Debug VM maple trees"
818         depends on DEBUG_VM                       818         depends on DEBUG_VM
819         select DEBUG_MAPLE_TREE                   819         select DEBUG_MAPLE_TREE
820         help                                      820         help
821           Enable VM maple tree debugging infor    821           Enable VM maple tree debugging information and extra validations.
822                                                   822 
823           If unsure, say N.                       823           If unsure, say N.
824                                                   824 
825 config DEBUG_VM_RB                                825 config DEBUG_VM_RB
826         bool "Debug VM red-black trees"           826         bool "Debug VM red-black trees"
827         depends on DEBUG_VM                       827         depends on DEBUG_VM
828         help                                      828         help
829           Enable VM red-black tree debugging i    829           Enable VM red-black tree debugging information and extra validations.
830                                                   830 
831           If unsure, say N.                       831           If unsure, say N.
832                                                   832 
833 config DEBUG_VM_PGFLAGS                           833 config DEBUG_VM_PGFLAGS
834         bool "Debug page-flags operations"        834         bool "Debug page-flags operations"
835         depends on DEBUG_VM                       835         depends on DEBUG_VM
836         help                                      836         help
837           Enables extra validation on page fla    837           Enables extra validation on page flags operations.
838                                                   838 
839           If unsure, say N.                       839           If unsure, say N.
840                                                   840 
841 config DEBUG_VM_PGTABLE                           841 config DEBUG_VM_PGTABLE
842         bool "Debug arch page table for semant    842         bool "Debug arch page table for semantics compliance"
843         depends on MMU                            843         depends on MMU
844         depends on ARCH_HAS_DEBUG_VM_PGTABLE      844         depends on ARCH_HAS_DEBUG_VM_PGTABLE
845         default y if DEBUG_VM                     845         default y if DEBUG_VM
846         help                                      846         help
847           This option provides a debug method     847           This option provides a debug method which can be used to test
848           architecture page table helper funct    848           architecture page table helper functions on various platforms in
849           verifying if they comply with expect    849           verifying if they comply with expected generic MM semantics. This
850           will help architecture code in makin    850           will help architecture code in making sure that any changes or
851           new additions of these helpers still    851           new additions of these helpers still conform to expected
852           semantics of the generic MM. Platfor    852           semantics of the generic MM. Platforms will have to opt in for
853           this through ARCH_HAS_DEBUG_VM_PGTAB    853           this through ARCH_HAS_DEBUG_VM_PGTABLE.
854                                                   854 
855           If unsure, say N.                       855           If unsure, say N.
856                                                   856 
857 config ARCH_HAS_DEBUG_VIRTUAL                     857 config ARCH_HAS_DEBUG_VIRTUAL
858         bool                                      858         bool
859                                                   859 
860 config DEBUG_VIRTUAL                              860 config DEBUG_VIRTUAL
861         bool "Debug VM translations"              861         bool "Debug VM translations"
862         depends on DEBUG_KERNEL && ARCH_HAS_DE    862         depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863         help                                      863         help
864           Enable some costly sanity checks in     864           Enable some costly sanity checks in virtual to page code. This can
865           catch mistakes with virt_to_page() a    865           catch mistakes with virt_to_page() and friends.
866                                                   866 
867           If unsure, say N.                       867           If unsure, say N.
868                                                   868 
869 config DEBUG_NOMMU_REGIONS                        869 config DEBUG_NOMMU_REGIONS
870         bool "Debug the global anon/private NO    870         bool "Debug the global anon/private NOMMU mapping region tree"
871         depends on DEBUG_KERNEL && !MMU           871         depends on DEBUG_KERNEL && !MMU
872         help                                      872         help
873           This option causes the global tree o    873           This option causes the global tree of anonymous and private mapping
874           regions to be regularly checked for     874           regions to be regularly checked for invalid topology.
875                                                   875 
876 config DEBUG_MEMORY_INIT                          876 config DEBUG_MEMORY_INIT
877         bool "Debug memory initialisation" if     877         bool "Debug memory initialisation" if EXPERT
878         default !EXPERT                           878         default !EXPERT
879         help                                      879         help
880           Enable this for additional checks du    880           Enable this for additional checks during memory initialisation.
881           The sanity checks verify aspects of     881           The sanity checks verify aspects of the VM such as the memory model
882           and other information provided by th    882           and other information provided by the architecture. Verbose
883           information will be printed at KERN_    883           information will be printed at KERN_DEBUG loglevel depending
884           on the mminit_loglevel= command-line    884           on the mminit_loglevel= command-line option.
885                                                   885 
886           If unsure, say Y                        886           If unsure, say Y
887                                                   887 
888 config MEMORY_NOTIFIER_ERROR_INJECT               888 config MEMORY_NOTIFIER_ERROR_INJECT
889         tristate "Memory hotplug notifier erro    889         tristate "Memory hotplug notifier error injection module"
890         depends on MEMORY_HOTPLUG && NOTIFIER_    890         depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
891         help                                      891         help
892           This option provides the ability to     892           This option provides the ability to inject artificial errors to
893           memory hotplug notifier chain callba    893           memory hotplug notifier chain callbacks.  It is controlled through
894           debugfs interface under /sys/kernel/    894           debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895                                                   895 
896           If the notifier call chain should be    896           If the notifier call chain should be failed with some events
897           notified, write the error code to "a    897           notified, write the error code to "actions/<notifier event>/error".
898                                                   898 
899           Example: Inject memory hotplug offli    899           Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900                                                   900 
901           # cd /sys/kernel/debug/notifier-erro    901           # cd /sys/kernel/debug/notifier-error-inject/memory
902           # echo -12 > actions/MEM_GOING_OFFLI    902           # echo -12 > actions/MEM_GOING_OFFLINE/error
903           # echo offline > /sys/devices/system    903           # echo offline > /sys/devices/system/memory/memoryXXX/state
904           bash: echo: write error: Cannot allo    904           bash: echo: write error: Cannot allocate memory
905                                                   905 
906           To compile this code as a module, ch    906           To compile this code as a module, choose M here: the module will
907           be called memory-notifier-error-inje    907           be called memory-notifier-error-inject.
908                                                   908 
909           If unsure, say N.                       909           If unsure, say N.
910                                                   910 
911 config DEBUG_PER_CPU_MAPS                         911 config DEBUG_PER_CPU_MAPS
912         bool "Debug access to per_cpu maps"       912         bool "Debug access to per_cpu maps"
913         depends on DEBUG_KERNEL                   913         depends on DEBUG_KERNEL
914         depends on SMP                            914         depends on SMP
915         help                                      915         help
916           Say Y to verify that the per_cpu map    916           Say Y to verify that the per_cpu map being accessed has
917           been set up. This adds a fair amount    917           been set up. This adds a fair amount of code to kernel memory
918           and decreases performance.              918           and decreases performance.
919                                                   919 
920           Say N if unsure.                        920           Say N if unsure.
921                                                   921 
922 config DEBUG_KMAP_LOCAL                           922 config DEBUG_KMAP_LOCAL
923         bool "Debug kmap_local temporary mappi    923         bool "Debug kmap_local temporary mappings"
924         depends on DEBUG_KERNEL && KMAP_LOCAL     924         depends on DEBUG_KERNEL && KMAP_LOCAL
925         help                                      925         help
926           This option enables additional error    926           This option enables additional error checking for the kmap_local
927           infrastructure.  Disable for product    927           infrastructure.  Disable for production use.
928                                                   928 
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP         929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
930         bool                                      930         bool
931                                                   931 
932 config DEBUG_KMAP_LOCAL_FORCE_MAP                 932 config DEBUG_KMAP_LOCAL_FORCE_MAP
933         bool "Enforce kmap_local temporary map    933         bool "Enforce kmap_local temporary mappings"
934         depends on DEBUG_KERNEL && ARCH_SUPPOR    934         depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935         select KMAP_LOCAL                         935         select KMAP_LOCAL
936         select DEBUG_KMAP_LOCAL                   936         select DEBUG_KMAP_LOCAL
937         help                                      937         help
938           This option enforces temporary mappi    938           This option enforces temporary mappings through the kmap_local
939           mechanism for non-highmem pages and     939           mechanism for non-highmem pages and on non-highmem systems.
940           Disable this for production systems!    940           Disable this for production systems!
941                                                   941 
942 config DEBUG_HIGHMEM                              942 config DEBUG_HIGHMEM
943         bool "Highmem debugging"                  943         bool "Highmem debugging"
944         depends on DEBUG_KERNEL && HIGHMEM        944         depends on DEBUG_KERNEL && HIGHMEM
945         select DEBUG_KMAP_LOCAL_FORCE_MAP if A    945         select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
946         select DEBUG_KMAP_LOCAL                   946         select DEBUG_KMAP_LOCAL
947         help                                      947         help
948           This option enables additional error    948           This option enables additional error checking for high memory
949           systems.  Disable for production sys    949           systems.  Disable for production systems.
950                                                   950 
951 config HAVE_DEBUG_STACKOVERFLOW                   951 config HAVE_DEBUG_STACKOVERFLOW
952         bool                                      952         bool
953                                                   953 
954 config DEBUG_STACKOVERFLOW                        954 config DEBUG_STACKOVERFLOW
955         bool "Check for stack overflows"          955         bool "Check for stack overflows"
956         depends on DEBUG_KERNEL && HAVE_DEBUG_    956         depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957         help                                      957         help
958           Say Y here if you want to check for     958           Say Y here if you want to check for overflows of kernel, IRQ
959           and exception stacks (if your archit    959           and exception stacks (if your architecture uses them). This
960           option will show detailed messages i    960           option will show detailed messages if free stack space drops
961           below a certain limit.                  961           below a certain limit.
962                                                   962 
963           These kinds of bugs usually occur wh    963           These kinds of bugs usually occur when call-chains in the
964           kernel get too deep, especially when    964           kernel get too deep, especially when interrupts are
965           involved.                               965           involved.
966                                                   966 
967           Use this in cases where you see appa    967           Use this in cases where you see apparently random memory
968           corruption, especially if it appears    968           corruption, especially if it appears in 'struct thread_info'
969                                                   969 
970           If in doubt, say "N".                   970           If in doubt, say "N".
971                                                   971 
972 config CODE_TAGGING                               972 config CODE_TAGGING
973         bool                                      973         bool
974         select KALLSYMS                           974         select KALLSYMS
975                                                   975 
976 config MEM_ALLOC_PROFILING                        976 config MEM_ALLOC_PROFILING
977         bool "Enable memory allocation profili    977         bool "Enable memory allocation profiling"
978         default n                                 978         default n
979         depends on PROC_FS                        979         depends on PROC_FS
980         depends on !DEBUG_FORCE_WEAK_PER_CPU      980         depends on !DEBUG_FORCE_WEAK_PER_CPU
981         select CODE_TAGGING                       981         select CODE_TAGGING
982         select PAGE_EXTENSION                     982         select PAGE_EXTENSION
983         select SLAB_OBJ_EXT                       983         select SLAB_OBJ_EXT
984         help                                      984         help
985           Track allocation source code and rec    985           Track allocation source code and record total allocation size
986           initiated at that code location. The    986           initiated at that code location. The mechanism can be used to track
987           memory leaks with a low performance     987           memory leaks with a low performance and memory impact.
988                                                   988 
989 config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT     989 config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
990         bool "Enable memory allocation profili    990         bool "Enable memory allocation profiling by default"
991         default y                                 991         default y
992         depends on MEM_ALLOC_PROFILING            992         depends on MEM_ALLOC_PROFILING
993                                                   993 
994 config MEM_ALLOC_PROFILING_DEBUG                  994 config MEM_ALLOC_PROFILING_DEBUG
995         bool "Memory allocation profiler debug    995         bool "Memory allocation profiler debugging"
996         default n                                 996         default n
997         depends on MEM_ALLOC_PROFILING            997         depends on MEM_ALLOC_PROFILING
998         select MEM_ALLOC_PROFILING_ENABLED_BY_    998         select MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
999         help                                      999         help
1000           Adds warnings with helpful error me    1000           Adds warnings with helpful error messages for memory allocation
1001           profiling.                             1001           profiling.
1002                                                  1002 
1003 source "lib/Kconfig.kasan"                       1003 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence"                      1004 source "lib/Kconfig.kfence"
1005 source "lib/Kconfig.kmsan"                       1005 source "lib/Kconfig.kmsan"
1006                                                  1006 
1007 endmenu # "Memory Debugging"                     1007 endmenu # "Memory Debugging"
1008                                                  1008 
1009 config DEBUG_SHIRQ                               1009 config DEBUG_SHIRQ
1010         bool "Debug shared IRQ handlers"         1010         bool "Debug shared IRQ handlers"
1011         depends on DEBUG_KERNEL                  1011         depends on DEBUG_KERNEL
1012         help                                     1012         help
1013           Enable this to generate a spurious     1013           Enable this to generate a spurious interrupt just before a shared
1014           interrupt handler is deregistered (    1014           interrupt handler is deregistered (generating one when registering
1015           is currently disabled). Drivers nee    1015           is currently disabled). Drivers need to handle this correctly. Some
1016           don't and need to be caught.           1016           don't and need to be caught.
1017                                                  1017 
1018 menu "Debug Oops, Lockups and Hangs"             1018 menu "Debug Oops, Lockups and Hangs"
1019                                                  1019 
1020 config PANIC_ON_OOPS                             1020 config PANIC_ON_OOPS
1021         bool "Panic on Oops"                     1021         bool "Panic on Oops"
1022         help                                     1022         help
1023           Say Y here to enable the kernel to     1023           Say Y here to enable the kernel to panic when it oopses. This
1024           has the same effect as setting oops    1024           has the same effect as setting oops=panic on the kernel command
1025           line.                                  1025           line.
1026                                                  1026 
1027           This feature is useful to ensure th    1027           This feature is useful to ensure that the kernel does not do
1028           anything erroneous after an oops wh    1028           anything erroneous after an oops which could result in data
1029           corruption or other issues.            1029           corruption or other issues.
1030                                                  1030 
1031           Say N if unsure.                       1031           Say N if unsure.
1032                                                  1032 
1033 config PANIC_ON_OOPS_VALUE                       1033 config PANIC_ON_OOPS_VALUE
1034         int                                      1034         int
1035         range 0 1                                1035         range 0 1
1036         default 0 if !PANIC_ON_OOPS              1036         default 0 if !PANIC_ON_OOPS
1037         default 1 if PANIC_ON_OOPS               1037         default 1 if PANIC_ON_OOPS
1038                                                  1038 
1039 config PANIC_TIMEOUT                             1039 config PANIC_TIMEOUT
1040         int "panic timeout"                      1040         int "panic timeout"
1041         default 0                                1041         default 0
1042         help                                     1042         help
1043           Set the timeout value (in seconds)     1043           Set the timeout value (in seconds) until a reboot occurs when
1044           the kernel panics. If n = 0, then w    1044           the kernel panics. If n = 0, then we wait forever. A timeout
1045           value n > 0 will wait n seconds bef    1045           value n > 0 will wait n seconds before rebooting, while a timeout
1046           value n < 0 will reboot immediately    1046           value n < 0 will reboot immediately. This setting can be overridden
1047           with the kernel command line option    1047           with the kernel command line option panic=, and from userspace via
1048           /proc/sys/kernel/panic.                1048           /proc/sys/kernel/panic.
1049                                                  1049 
1050 config LOCKUP_DETECTOR                           1050 config LOCKUP_DETECTOR
1051         bool                                     1051         bool
1052                                                  1052 
1053 config SOFTLOCKUP_DETECTOR                       1053 config SOFTLOCKUP_DETECTOR
1054         bool "Detect Soft Lockups"               1054         bool "Detect Soft Lockups"
1055         depends on DEBUG_KERNEL && !S390         1055         depends on DEBUG_KERNEL && !S390
1056         select LOCKUP_DETECTOR                   1056         select LOCKUP_DETECTOR
1057         help                                     1057         help
1058           Say Y here to enable the kernel to     1058           Say Y here to enable the kernel to act as a watchdog to detect
1059           soft lockups.                          1059           soft lockups.
1060                                                  1060 
1061           Softlockups are bugs that cause the    1061           Softlockups are bugs that cause the kernel to loop in kernel
1062           mode for more than 20 seconds, with    1062           mode for more than 20 seconds, without giving other tasks a
1063           chance to run.  The current stack t    1063           chance to run.  The current stack trace is displayed upon
1064           detection and the system will stay     1064           detection and the system will stay locked up.
1065                                                  1065 
1066 config SOFTLOCKUP_DETECTOR_INTR_STORM            1066 config SOFTLOCKUP_DETECTOR_INTR_STORM
1067         bool "Detect Interrupt Storm in Soft     1067         bool "Detect Interrupt Storm in Soft Lockups"
1068         depends on SOFTLOCKUP_DETECTOR && IRQ    1068         depends on SOFTLOCKUP_DETECTOR && IRQ_TIME_ACCOUNTING
1069         select GENERIC_IRQ_STAT_SNAPSHOT         1069         select GENERIC_IRQ_STAT_SNAPSHOT
1070         default y if NR_CPUS <= 128              1070         default y if NR_CPUS <= 128
1071         help                                     1071         help
1072           Say Y here to enable the kernel to     1072           Say Y here to enable the kernel to detect interrupt storm
1073           during "soft lockups".                 1073           during "soft lockups".
1074                                                  1074 
1075           "soft lockups" can be caused by a v    1075           "soft lockups" can be caused by a variety of reasons. If one is
1076           caused by an interrupt storm, then     1076           caused by an interrupt storm, then the storming interrupts will not
1077           be on the callstack. To detect this    1077           be on the callstack. To detect this case, it is necessary to report
1078           the CPU stats and the interrupt cou    1078           the CPU stats and the interrupt counts during the "soft lockups".
1079                                                  1079 
1080 config BOOTPARAM_SOFTLOCKUP_PANIC                1080 config BOOTPARAM_SOFTLOCKUP_PANIC
1081         bool "Panic (Reboot) On Soft Lockups"    1081         bool "Panic (Reboot) On Soft Lockups"
1082         depends on SOFTLOCKUP_DETECTOR           1082         depends on SOFTLOCKUP_DETECTOR
1083         help                                     1083         help
1084           Say Y here to enable the kernel to     1084           Say Y here to enable the kernel to panic on "soft lockups",
1085           which are bugs that cause the kerne    1085           which are bugs that cause the kernel to loop in kernel
1086           mode for more than 20 seconds (conf    1086           mode for more than 20 seconds (configurable using the watchdog_thresh
1087           sysctl), without giving other tasks    1087           sysctl), without giving other tasks a chance to run.
1088                                                  1088 
1089           The panic can be used in combinatio    1089           The panic can be used in combination with panic_timeout,
1090           to cause the system to reboot autom    1090           to cause the system to reboot automatically after a
1091           lockup has been detected. This feat    1091           lockup has been detected. This feature is useful for
1092           high-availability systems that have    1092           high-availability systems that have uptime guarantees and
1093           where a lockup must be resolved ASA    1093           where a lockup must be resolved ASAP.
1094                                                  1094 
1095           Say N if unsure.                       1095           Say N if unsure.
1096                                                  1096 
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY            1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY
1098         bool                                     1098         bool
1099         depends on SMP                           1099         depends on SMP
1100         default y                                1100         default y
1101                                                  1101 
1102 #                                                1102 #
1103 # Global switch whether to build a hardlockup    1103 # Global switch whether to build a hardlockup detector at all. It is available
1104 # only when the architecture supports at leas    1104 # only when the architecture supports at least one implementation. There are
1105 # two exceptions. The hardlockup detector is     1105 # two exceptions. The hardlockup detector is never enabled on:
1106 #                                                1106 #
1107 #       s390: it reported many false positive    1107 #       s390: it reported many false positives there
1108 #                                                1108 #
1109 #       sparc64: has a custom implementation     1109 #       sparc64: has a custom implementation which is not using the common
1110 #               hardlockup command line optio    1110 #               hardlockup command line options and sysctl interface.
1111 #                                                1111 #
1112 config HARDLOCKUP_DETECTOR                       1112 config HARDLOCKUP_DETECTOR
1113         bool "Detect Hard Lockups"               1113         bool "Detect Hard Lockups"
1114         depends on DEBUG_KERNEL && !S390 && !    1114         depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
1115         depends on HAVE_HARDLOCKUP_DETECTOR_P    1115         depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1116         imply HARDLOCKUP_DETECTOR_PERF           1116         imply HARDLOCKUP_DETECTOR_PERF
1117         imply HARDLOCKUP_DETECTOR_BUDDY          1117         imply HARDLOCKUP_DETECTOR_BUDDY
1118         imply HARDLOCKUP_DETECTOR_ARCH           1118         imply HARDLOCKUP_DETECTOR_ARCH
1119         select LOCKUP_DETECTOR                   1119         select LOCKUP_DETECTOR
1120                                                  1120 
1121         help                                     1121         help
1122           Say Y here to enable the kernel to     1122           Say Y here to enable the kernel to act as a watchdog to detect
1123           hard lockups.                          1123           hard lockups.
1124                                                  1124 
1125           Hardlockups are bugs that cause the    1125           Hardlockups are bugs that cause the CPU to loop in kernel mode
1126           for more than 10 seconds, without l    1126           for more than 10 seconds, without letting other interrupts have a
1127           chance to run.  The current stack t    1127           chance to run.  The current stack trace is displayed upon detection
1128           and the system will stay locked up.    1128           and the system will stay locked up.
1129                                                  1129 
1130 #                                                1130 #
1131 # Note that arch-specific variants are always    1131 # Note that arch-specific variants are always preferred.
1132 #                                                1132 #
1133 config HARDLOCKUP_DETECTOR_PREFER_BUDDY          1133 config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1134         bool "Prefer the buddy CPU hardlockup    1134         bool "Prefer the buddy CPU hardlockup detector"
1135         depends on HARDLOCKUP_DETECTOR           1135         depends on HARDLOCKUP_DETECTOR
1136         depends on HAVE_HARDLOCKUP_DETECTOR_P    1136         depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
1137         depends on !HAVE_HARDLOCKUP_DETECTOR_    1137         depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1138         help                                     1138         help
1139           Say Y here to prefer the buddy hard    1139           Say Y here to prefer the buddy hardlockup detector over the perf one.
1140                                                  1140 
1141           With the buddy detector, each CPU u    1141           With the buddy detector, each CPU uses its softlockup hrtimer
1142           to check that the next CPU is proce    1142           to check that the next CPU is processing hrtimer interrupts by
1143           verifying that a counter is increas    1143           verifying that a counter is increasing.
1144                                                  1144 
1145           This hardlockup detector is useful     1145           This hardlockup detector is useful on systems that don't have
1146           an arch-specific hardlockup detecto    1146           an arch-specific hardlockup detector or if resources needed
1147           for the hardlockup detector are bet    1147           for the hardlockup detector are better used for other things.
1148                                                  1148 
1149 config HARDLOCKUP_DETECTOR_PERF                  1149 config HARDLOCKUP_DETECTOR_PERF
1150         bool                                     1150         bool
1151         depends on HARDLOCKUP_DETECTOR           1151         depends on HARDLOCKUP_DETECTOR
1152         depends on HAVE_HARDLOCKUP_DETECTOR_P    1152         depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
1153         depends on !HAVE_HARDLOCKUP_DETECTOR_    1153         depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1154         select HARDLOCKUP_DETECTOR_COUNTS_HRT    1154         select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1155                                                  1155 
1156 config HARDLOCKUP_DETECTOR_BUDDY                 1156 config HARDLOCKUP_DETECTOR_BUDDY
1157         bool                                     1157         bool
1158         depends on HARDLOCKUP_DETECTOR           1158         depends on HARDLOCKUP_DETECTOR
1159         depends on HAVE_HARDLOCKUP_DETECTOR_B    1159         depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1160         depends on !HAVE_HARDLOCKUP_DETECTOR_    1160         depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
1161         depends on !HAVE_HARDLOCKUP_DETECTOR_    1161         depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1162         select HARDLOCKUP_DETECTOR_COUNTS_HRT    1162         select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1163                                                  1163 
1164 config HARDLOCKUP_DETECTOR_ARCH                  1164 config HARDLOCKUP_DETECTOR_ARCH
1165         bool                                     1165         bool
1166         depends on HARDLOCKUP_DETECTOR           1166         depends on HARDLOCKUP_DETECTOR
1167         depends on HAVE_HARDLOCKUP_DETECTOR_A    1167         depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1168         help                                     1168         help
1169           The arch-specific implementation of    1169           The arch-specific implementation of the hardlockup detector will
1170           be used.                               1170           be used.
1171                                                  1171 
1172 #                                                1172 #
1173 # Both the "perf" and "buddy" hardlockup dete    1173 # Both the "perf" and "buddy" hardlockup detectors count hrtimer
1174 # interrupts. This config enables functions m    1174 # interrupts. This config enables functions managing this common code.
1175 #                                                1175 #
1176 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER        1176 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1177         bool                                     1177         bool
1178         select SOFTLOCKUP_DETECTOR               1178         select SOFTLOCKUP_DETECTOR
1179                                                  1179 
1180 #                                                1180 #
1181 # Enables a timestamp based low pass filter t    1181 # Enables a timestamp based low pass filter to compensate for perf based
1182 # hard lockup detection which runs too fast d    1182 # hard lockup detection which runs too fast due to turbo modes.
1183 #                                                1183 #
1184 config HARDLOCKUP_CHECK_TIMESTAMP                1184 config HARDLOCKUP_CHECK_TIMESTAMP
1185         bool                                     1185         bool
1186                                                  1186 
1187 config BOOTPARAM_HARDLOCKUP_PANIC                1187 config BOOTPARAM_HARDLOCKUP_PANIC
1188         bool "Panic (Reboot) On Hard Lockups"    1188         bool "Panic (Reboot) On Hard Lockups"
1189         depends on HARDLOCKUP_DETECTOR           1189         depends on HARDLOCKUP_DETECTOR
1190         help                                     1190         help
1191           Say Y here to enable the kernel to     1191           Say Y here to enable the kernel to panic on "hard lockups",
1192           which are bugs that cause the kerne    1192           which are bugs that cause the kernel to loop in kernel
1193           mode with interrupts disabled for m    1193           mode with interrupts disabled for more than 10 seconds (configurable
1194           using the watchdog_thresh sysctl).     1194           using the watchdog_thresh sysctl).
1195                                                  1195 
1196           Say N if unsure.                       1196           Say N if unsure.
1197                                                  1197 
1198 config DETECT_HUNG_TASK                          1198 config DETECT_HUNG_TASK
1199         bool "Detect Hung Tasks"                 1199         bool "Detect Hung Tasks"
1200         depends on DEBUG_KERNEL                  1200         depends on DEBUG_KERNEL
1201         default SOFTLOCKUP_DETECTOR              1201         default SOFTLOCKUP_DETECTOR
1202         help                                     1202         help
1203           Say Y here to enable the kernel to     1203           Say Y here to enable the kernel to detect "hung tasks",
1204           which are bugs that cause the task     1204           which are bugs that cause the task to be stuck in
1205           uninterruptible "D" state indefinit    1205           uninterruptible "D" state indefinitely.
1206                                                  1206 
1207           When a hung task is detected, the k    1207           When a hung task is detected, the kernel will print the
1208           current stack trace (which you shou    1208           current stack trace (which you should report), but the
1209           task will stay in uninterruptible s    1209           task will stay in uninterruptible state. If lockdep is
1210           enabled then all held locks will al    1210           enabled then all held locks will also be reported. This
1211           feature has negligible overhead.       1211           feature has negligible overhead.
1212                                                  1212 
1213 config DEFAULT_HUNG_TASK_TIMEOUT                 1213 config DEFAULT_HUNG_TASK_TIMEOUT
1214         int "Default timeout for hung task de    1214         int "Default timeout for hung task detection (in seconds)"
1215         depends on DETECT_HUNG_TASK              1215         depends on DETECT_HUNG_TASK
1216         default 120                              1216         default 120
1217         help                                     1217         help
1218           This option controls the default ti    1218           This option controls the default timeout (in seconds) used
1219           to determine when a task has become    1219           to determine when a task has become non-responsive and should
1220           be considered hung.                    1220           be considered hung.
1221                                                  1221 
1222           It can be adjusted at runtime via t    1222           It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223           sysctl or by writing a value to        1223           sysctl or by writing a value to
1224           /proc/sys/kernel/hung_task_timeout_    1224           /proc/sys/kernel/hung_task_timeout_secs.
1225                                                  1225 
1226           A timeout of 0 disables the check.     1226           A timeout of 0 disables the check.  The default is two minutes.
1227           Keeping the default should be fine     1227           Keeping the default should be fine in most cases.
1228                                                  1228 
1229 config BOOTPARAM_HUNG_TASK_PANIC                 1229 config BOOTPARAM_HUNG_TASK_PANIC
1230         bool "Panic (Reboot) On Hung Tasks"      1230         bool "Panic (Reboot) On Hung Tasks"
1231         depends on DETECT_HUNG_TASK              1231         depends on DETECT_HUNG_TASK
1232         help                                     1232         help
1233           Say Y here to enable the kernel to     1233           Say Y here to enable the kernel to panic on "hung tasks",
1234           which are bugs that cause the kerne    1234           which are bugs that cause the kernel to leave a task stuck
1235           in uninterruptible "D" state.          1235           in uninterruptible "D" state.
1236                                                  1236 
1237           The panic can be used in combinatio    1237           The panic can be used in combination with panic_timeout,
1238           to cause the system to reboot autom    1238           to cause the system to reboot automatically after a
1239           hung task has been detected. This f    1239           hung task has been detected. This feature is useful for
1240           high-availability systems that have    1240           high-availability systems that have uptime guarantees and
1241           where a hung tasks must be resolved    1241           where a hung tasks must be resolved ASAP.
1242                                                  1242 
1243           Say N if unsure.                       1243           Say N if unsure.
1244                                                  1244 
1245 config WQ_WATCHDOG                               1245 config WQ_WATCHDOG
1246         bool "Detect Workqueue Stalls"           1246         bool "Detect Workqueue Stalls"
1247         depends on DEBUG_KERNEL                  1247         depends on DEBUG_KERNEL
1248         help                                     1248         help
1249           Say Y here to enable stall detectio    1249           Say Y here to enable stall detection on workqueues.  If a
1250           worker pool doesn't make forward pr    1250           worker pool doesn't make forward progress on a pending work
1251           item for over a given amount of tim    1251           item for over a given amount of time, 30s by default, a
1252           warning message is printed along wi    1252           warning message is printed along with dump of workqueue
1253           state.  This can be configured thro    1253           state.  This can be configured through kernel parameter
1254           "workqueue.watchdog_thresh" and its    1254           "workqueue.watchdog_thresh" and its sysfs counterpart.
1255                                                  1255 
1256 config WQ_CPU_INTENSIVE_REPORT                   1256 config WQ_CPU_INTENSIVE_REPORT
1257         bool "Report per-cpu work items which    1257         bool "Report per-cpu work items which hog CPU for too long"
1258         depends on DEBUG_KERNEL                  1258         depends on DEBUG_KERNEL
1259         help                                     1259         help
1260           Say Y here to enable reporting of c    1260           Say Y here to enable reporting of concurrency-managed per-cpu work
1261           items that hog CPUs for longer than    1261           items that hog CPUs for longer than
1262           workqueue.cpu_intensive_thresh_us.     1262           workqueue.cpu_intensive_thresh_us. Workqueue automatically
1263           detects and excludes them from conc    1263           detects and excludes them from concurrency management to prevent
1264           them from stalling other per-cpu wo    1264           them from stalling other per-cpu work items. Occassional
1265           triggering may not necessarily indi    1265           triggering may not necessarily indicate a problem. Repeated
1266           triggering likely indicates that th    1266           triggering likely indicates that the work item should be switched
1267           to use an unbound workqueue.           1267           to use an unbound workqueue.
1268                                                  1268 
1269 config TEST_LOCKUP                               1269 config TEST_LOCKUP
1270         tristate "Test module to generate loc    1270         tristate "Test module to generate lockups"
1271         depends on m                             1271         depends on m
1272         help                                     1272         help
1273           This builds the "test_lockup" modul    1273           This builds the "test_lockup" module that helps to make sure
1274           that watchdogs and lockup detectors    1274           that watchdogs and lockup detectors are working properly.
1275                                                  1275 
1276           Depending on module parameters it c    1276           Depending on module parameters it could emulate soft or hard
1277           lockup, "hung task", or locking arb    1277           lockup, "hung task", or locking arbitrary lock for a long time.
1278           Also it could generate series of lo    1278           Also it could generate series of lockups with cooling-down periods.
1279                                                  1279 
1280           If unsure, say N.                      1280           If unsure, say N.
1281                                                  1281 
1282 endmenu # "Debug lockups and hangs"              1282 endmenu # "Debug lockups and hangs"
1283                                                  1283 
1284 menu "Scheduler Debugging"                       1284 menu "Scheduler Debugging"
1285                                                  1285 
1286 config SCHED_DEBUG                               1286 config SCHED_DEBUG
1287         bool "Collect scheduler debugging inf    1287         bool "Collect scheduler debugging info"
1288         depends on DEBUG_KERNEL && DEBUG_FS      1288         depends on DEBUG_KERNEL && DEBUG_FS
1289         default y                                1289         default y
1290         help                                     1290         help
1291           If you say Y here, the /sys/kernel/    1291           If you say Y here, the /sys/kernel/debug/sched file will be provided
1292           that can help debug the scheduler.     1292           that can help debug the scheduler. The runtime overhead of this
1293           option is minimal.                     1293           option is minimal.
1294                                                  1294 
1295 config SCHED_INFO                                1295 config SCHED_INFO
1296         bool                                     1296         bool
1297         default n                                1297         default n
1298                                                  1298 
1299 config SCHEDSTATS                                1299 config SCHEDSTATS
1300         bool "Collect scheduler statistics"      1300         bool "Collect scheduler statistics"
1301         depends on PROC_FS                       1301         depends on PROC_FS
1302         select SCHED_INFO                        1302         select SCHED_INFO
1303         help                                     1303         help
1304           If you say Y here, additional code     1304           If you say Y here, additional code will be inserted into the
1305           scheduler and related routines to c    1305           scheduler and related routines to collect statistics about
1306           scheduler behavior and provide them    1306           scheduler behavior and provide them in /proc/schedstat.  These
1307           stats may be useful for both tuning    1307           stats may be useful for both tuning and debugging the scheduler
1308           If you aren't debugging the schedul    1308           If you aren't debugging the scheduler or trying to tune a specific
1309           application, you can say N to avoid    1309           application, you can say N to avoid the very slight overhead
1310           this adds.                             1310           this adds.
1311                                                  1311 
1312 endmenu                                          1312 endmenu
1313                                                  1313 
1314 config DEBUG_TIMEKEEPING                         1314 config DEBUG_TIMEKEEPING
1315         bool "Enable extra timekeeping sanity    1315         bool "Enable extra timekeeping sanity checking"
1316         help                                     1316         help
1317           This option will enable additional     1317           This option will enable additional timekeeping sanity checks
1318           which may be helpful when diagnosin    1318           which may be helpful when diagnosing issues where timekeeping
1319           problems are suspected.                1319           problems are suspected.
1320                                                  1320 
1321           This may include checks in the time    1321           This may include checks in the timekeeping hotpaths, so this
1322           option may have a (very small) perf    1322           option may have a (very small) performance impact to some
1323           workloads.                             1323           workloads.
1324                                                  1324 
1325           If unsure, say N.                      1325           If unsure, say N.
1326                                                  1326 
1327 config DEBUG_PREEMPT                             1327 config DEBUG_PREEMPT
1328         bool "Debug preemptible kernel"          1328         bool "Debug preemptible kernel"
1329         depends on DEBUG_KERNEL && PREEMPTION    1329         depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1330         help                                     1330         help
1331           If you say Y here then the kernel w    1331           If you say Y here then the kernel will use a debug variant of the
1332           commonly used smp_processor_id() fu    1332           commonly used smp_processor_id() function and will print warnings
1333           if kernel code uses it in a preempt    1333           if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334           will detect preemption count underf    1334           will detect preemption count underflows.
1335                                                  1335 
1336           This option has potential to introd    1336           This option has potential to introduce high runtime overhead,
1337           depending on workload as it trigger    1337           depending on workload as it triggers debugging routines for each
1338           this_cpu operation. It should only     1338           this_cpu operation. It should only be used for debugging purposes.
1339                                                  1339 
1340 menu "Lock Debugging (spinlocks, mutexes, etc    1340 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341                                                  1341 
1342 config LOCK_DEBUGGING_SUPPORT                    1342 config LOCK_DEBUGGING_SUPPORT
1343         bool                                     1343         bool
1344         depends on TRACE_IRQFLAGS_SUPPORT &&     1344         depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345         default y                                1345         default y
1346                                                  1346 
1347 config PROVE_LOCKING                             1347 config PROVE_LOCKING
1348         bool "Lock debugging: prove locking c    1348         bool "Lock debugging: prove locking correctness"
1349         depends on DEBUG_KERNEL && LOCK_DEBUG    1349         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350         select LOCKDEP                           1350         select LOCKDEP
1351         select DEBUG_SPINLOCK                    1351         select DEBUG_SPINLOCK
1352         select DEBUG_MUTEXES if !PREEMPT_RT      1352         select DEBUG_MUTEXES if !PREEMPT_RT
1353         select DEBUG_RT_MUTEXES if RT_MUTEXES    1353         select DEBUG_RT_MUTEXES if RT_MUTEXES
1354         select DEBUG_RWSEMS if !PREEMPT_RT       1354         select DEBUG_RWSEMS if !PREEMPT_RT
1355         select DEBUG_WW_MUTEX_SLOWPATH           1355         select DEBUG_WW_MUTEX_SLOWPATH
1356         select DEBUG_LOCK_ALLOC                  1356         select DEBUG_LOCK_ALLOC
1357         select PREEMPT_COUNT if !ARCH_NO_PREE    1357         select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358         select TRACE_IRQFLAGS                    1358         select TRACE_IRQFLAGS
1359         default n                                1359         default n
1360         help                                     1360         help
1361          This feature enables the kernel to p    1361          This feature enables the kernel to prove that all locking
1362          that occurs in the kernel runtime is    1362          that occurs in the kernel runtime is mathematically
1363          correct: that under no circumstance     1363          correct: that under no circumstance could an arbitrary (and
1364          not yet triggered) combination of ob    1364          not yet triggered) combination of observed locking
1365          sequences (on an arbitrary number of    1365          sequences (on an arbitrary number of CPUs, running an
1366          arbitrary number of tasks and interr    1366          arbitrary number of tasks and interrupt contexts) cause a
1367          deadlock.                               1367          deadlock.
1368                                                  1368 
1369          In short, this feature enables the k    1369          In short, this feature enables the kernel to report locking
1370          related deadlocks before they actual    1370          related deadlocks before they actually occur.
1371                                                  1371 
1372          The proof does not depend on how har    1372          The proof does not depend on how hard and complex a
1373          deadlock scenario would be to trigge    1373          deadlock scenario would be to trigger: how many
1374          participant CPUs, tasks and irq-cont    1374          participant CPUs, tasks and irq-contexts would be needed
1375          for it to trigger. The proof also do    1375          for it to trigger. The proof also does not depend on
1376          timing: if a race and a resulting de    1376          timing: if a race and a resulting deadlock is possible
1377          theoretically (no matter how unlikel    1377          theoretically (no matter how unlikely the race scenario
1378          is), it will be proven so and will i    1378          is), it will be proven so and will immediately be
1379          reported by the kernel (once the eve    1379          reported by the kernel (once the event is observed that
1380          makes the deadlock theoretically pos    1380          makes the deadlock theoretically possible).
1381                                                  1381 
1382          If a deadlock is impossible (i.e. th    1382          If a deadlock is impossible (i.e. the locking rules, as
1383          observed by the kernel, are mathemat    1383          observed by the kernel, are mathematically correct), the
1384          kernel reports nothing.                 1384          kernel reports nothing.
1385                                                  1385 
1386          NOTE: this feature can also be enabl    1386          NOTE: this feature can also be enabled for rwlocks, mutexes
1387          and rwsems - in which case all depen    1387          and rwsems - in which case all dependencies between these
1388          different locking variants are obser    1388          different locking variants are observed and mapped too, and
1389          the proof of observed correctness is    1389          the proof of observed correctness is also maintained for an
1390          arbitrary combination of these separ    1390          arbitrary combination of these separate locking variants.
1391                                                  1391 
1392          For more details, see Documentation/    1392          For more details, see Documentation/locking/lockdep-design.rst.
1393                                                  1393 
1394 config PROVE_RAW_LOCK_NESTING                    1394 config PROVE_RAW_LOCK_NESTING
1395         bool "Enable raw_spinlock - spinlock     1395         bool "Enable raw_spinlock - spinlock nesting checks"
1396         depends on PROVE_LOCKING                 1396         depends on PROVE_LOCKING
1397         default n                                1397         default n
1398         help                                     1398         help
1399          Enable the raw_spinlock vs. spinlock    1399          Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400          that the lock nesting rules for PREE    1400          that the lock nesting rules for PREEMPT_RT enabled kernels are
1401          not violated.                           1401          not violated.
1402                                                  1402 
1403          NOTE: There are known nesting proble    1403          NOTE: There are known nesting problems. So if you enable this
1404          option expect lockdep splats until t    1404          option expect lockdep splats until these problems have been fully
1405          addressed which is work in progress.    1405          addressed which is work in progress. This config switch allows to
1406          identify and analyze these problems.    1406          identify and analyze these problems. It will be removed and the
1407          check permanently enabled once the m    1407          check permanently enabled once the main issues have been fixed.
1408                                                  1408 
1409          If unsure, select N.                    1409          If unsure, select N.
1410                                                  1410 
1411 config LOCK_STAT                                 1411 config LOCK_STAT
1412         bool "Lock usage statistics"             1412         bool "Lock usage statistics"
1413         depends on DEBUG_KERNEL && LOCK_DEBUG    1413         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414         select LOCKDEP                           1414         select LOCKDEP
1415         select DEBUG_SPINLOCK                    1415         select DEBUG_SPINLOCK
1416         select DEBUG_MUTEXES if !PREEMPT_RT      1416         select DEBUG_MUTEXES if !PREEMPT_RT
1417         select DEBUG_RT_MUTEXES if RT_MUTEXES    1417         select DEBUG_RT_MUTEXES if RT_MUTEXES
1418         select DEBUG_LOCK_ALLOC                  1418         select DEBUG_LOCK_ALLOC
1419         default n                                1419         default n
1420         help                                     1420         help
1421          This feature enables tracking lock c    1421          This feature enables tracking lock contention points
1422                                                  1422 
1423          For more details, see Documentation/    1423          For more details, see Documentation/locking/lockstat.rst
1424                                                  1424 
1425          This also enables lock events requir    1425          This also enables lock events required by "perf lock",
1426          subcommand of perf.                     1426          subcommand of perf.
1427          If you want to use "perf lock", you     1427          If you want to use "perf lock", you also need to turn on
1428          CONFIG_EVENT_TRACING.                   1428          CONFIG_EVENT_TRACING.
1429                                                  1429 
1430          CONFIG_LOCK_STAT defines "contended"    1430          CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431          (CONFIG_LOCKDEP defines "acquire" an    1431          (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432                                                  1432 
1433 config DEBUG_RT_MUTEXES                          1433 config DEBUG_RT_MUTEXES
1434         bool "RT Mutex debugging, deadlock de    1434         bool "RT Mutex debugging, deadlock detection"
1435         depends on DEBUG_KERNEL && RT_MUTEXES    1435         depends on DEBUG_KERNEL && RT_MUTEXES
1436         help                                     1436         help
1437          This allows rt mutex semantics viola    1437          This allows rt mutex semantics violations and rt mutex related
1438          deadlocks (lockups) to be detected a    1438          deadlocks (lockups) to be detected and reported automatically.
1439                                                  1439 
1440 config DEBUG_SPINLOCK                            1440 config DEBUG_SPINLOCK
1441         bool "Spinlock and rw-lock debugging:    1441         bool "Spinlock and rw-lock debugging: basic checks"
1442         depends on DEBUG_KERNEL                  1442         depends on DEBUG_KERNEL
1443         select UNINLINE_SPIN_UNLOCK              1443         select UNINLINE_SPIN_UNLOCK
1444         help                                     1444         help
1445           Say Y here and build SMP to catch m    1445           Say Y here and build SMP to catch missing spinlock initialization
1446           and certain other kinds of spinlock    1446           and certain other kinds of spinlock errors commonly made.  This is
1447           best used in conjunction with the N    1447           best used in conjunction with the NMI watchdog so that spinlock
1448           deadlocks are also debuggable.         1448           deadlocks are also debuggable.
1449                                                  1449 
1450 config DEBUG_MUTEXES                             1450 config DEBUG_MUTEXES
1451         bool "Mutex debugging: basic checks"     1451         bool "Mutex debugging: basic checks"
1452         depends on DEBUG_KERNEL && !PREEMPT_R    1452         depends on DEBUG_KERNEL && !PREEMPT_RT
1453         help                                     1453         help
1454          This feature allows mutex semantics     1454          This feature allows mutex semantics violations to be detected and
1455          reported.                               1455          reported.
1456                                                  1456 
1457 config DEBUG_WW_MUTEX_SLOWPATH                   1457 config DEBUG_WW_MUTEX_SLOWPATH
1458         bool "Wait/wound mutex debugging: Slo    1458         bool "Wait/wound mutex debugging: Slowpath testing"
1459         depends on DEBUG_KERNEL && LOCK_DEBUG    1459         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460         select DEBUG_LOCK_ALLOC                  1460         select DEBUG_LOCK_ALLOC
1461         select DEBUG_SPINLOCK                    1461         select DEBUG_SPINLOCK
1462         select DEBUG_MUTEXES if !PREEMPT_RT      1462         select DEBUG_MUTEXES if !PREEMPT_RT
1463         select DEBUG_RT_MUTEXES if PREEMPT_RT    1463         select DEBUG_RT_MUTEXES if PREEMPT_RT
1464         help                                     1464         help
1465          This feature enables slowpath testin    1465          This feature enables slowpath testing for w/w mutex users by
1466          injecting additional -EDEADLK wound/    1466          injecting additional -EDEADLK wound/backoff cases. Together with
1467          the full mutex checks enabled with (    1467          the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468          will test all possible w/w mutex int    1468          will test all possible w/w mutex interface abuse with the
1469          exception of simply not acquiring al    1469          exception of simply not acquiring all the required locks.
1470          Note that this feature can introduce    1470          Note that this feature can introduce significant overhead, so
1471          it really should not be enabled in a    1471          it really should not be enabled in a production or distro kernel,
1472          even a debug kernel.  If you are a d    1472          even a debug kernel.  If you are a driver writer, enable it.  If
1473          you are a distro, do not.               1473          you are a distro, do not.
1474                                                  1474 
1475 config DEBUG_RWSEMS                              1475 config DEBUG_RWSEMS
1476         bool "RW Semaphore debugging: basic c    1476         bool "RW Semaphore debugging: basic checks"
1477         depends on DEBUG_KERNEL && !PREEMPT_R    1477         depends on DEBUG_KERNEL && !PREEMPT_RT
1478         help                                     1478         help
1479           This debugging feature allows misma    1479           This debugging feature allows mismatched rw semaphore locks
1480           and unlocks to be detected and repo    1480           and unlocks to be detected and reported.
1481                                                  1481 
1482 config DEBUG_LOCK_ALLOC                          1482 config DEBUG_LOCK_ALLOC
1483         bool "Lock debugging: detect incorrec    1483         bool "Lock debugging: detect incorrect freeing of live locks"
1484         depends on DEBUG_KERNEL && LOCK_DEBUG    1484         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485         select DEBUG_SPINLOCK                    1485         select DEBUG_SPINLOCK
1486         select DEBUG_MUTEXES if !PREEMPT_RT      1486         select DEBUG_MUTEXES if !PREEMPT_RT
1487         select DEBUG_RT_MUTEXES if RT_MUTEXES    1487         select DEBUG_RT_MUTEXES if RT_MUTEXES
1488         select LOCKDEP                           1488         select LOCKDEP
1489         help                                     1489         help
1490          This feature will check whether any     1490          This feature will check whether any held lock (spinlock, rwlock,
1491          mutex or rwsem) is incorrectly freed    1491          mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492          memory-freeing routines (kfree(), km    1492          memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493          vfree(), etc.), whether a live lock     1493          vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494          spin_lock_init()/mutex_init()/etc.,     1494          spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495          held during task exit.                  1495          held during task exit.
1496                                                  1496 
1497 config LOCKDEP                                   1497 config LOCKDEP
1498         bool                                     1498         bool
1499         depends on DEBUG_KERNEL && LOCK_DEBUG    1499         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500         select STACKTRACE                        1500         select STACKTRACE
1501         select KALLSYMS                          1501         select KALLSYMS
1502         select KALLSYMS_ALL                      1502         select KALLSYMS_ALL
1503                                                  1503 
1504 config LOCKDEP_SMALL                             1504 config LOCKDEP_SMALL
1505         bool                                     1505         bool
1506                                                  1506 
1507 config LOCKDEP_BITS                              1507 config LOCKDEP_BITS
1508         int "Bitsize for MAX_LOCKDEP_ENTRIES"    1508         int "Bitsize for MAX_LOCKDEP_ENTRIES"
1509         depends on LOCKDEP && !LOCKDEP_SMALL     1509         depends on LOCKDEP && !LOCKDEP_SMALL
1510         range 10 30                              1510         range 10 30
1511         default 15                               1511         default 15
1512         help                                     1512         help
1513           Try increasing this value if you hi    1513           Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1514                                                  1514 
1515 config LOCKDEP_CHAINS_BITS                       1515 config LOCKDEP_CHAINS_BITS
1516         int "Bitsize for MAX_LOCKDEP_CHAINS"     1516         int "Bitsize for MAX_LOCKDEP_CHAINS"
1517         depends on LOCKDEP && !LOCKDEP_SMALL     1517         depends on LOCKDEP && !LOCKDEP_SMALL
1518         range 10 30                              1518         range 10 30
1519         default 16                               1519         default 16
1520         help                                     1520         help
1521           Try increasing this value if you hi    1521           Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1522                                                  1522 
1523 config LOCKDEP_STACK_TRACE_BITS                  1523 config LOCKDEP_STACK_TRACE_BITS
1524         int "Bitsize for MAX_STACK_TRACE_ENTR    1524         int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1525         depends on LOCKDEP && !LOCKDEP_SMALL     1525         depends on LOCKDEP && !LOCKDEP_SMALL
1526         range 10 30                              1526         range 10 30
1527         default 19                               1527         default 19
1528         help                                     1528         help
1529           Try increasing this value if you hi    1529           Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1530                                                  1530 
1531 config LOCKDEP_STACK_TRACE_HASH_BITS             1531 config LOCKDEP_STACK_TRACE_HASH_BITS
1532         int "Bitsize for STACK_TRACE_HASH_SIZ    1532         int "Bitsize for STACK_TRACE_HASH_SIZE"
1533         depends on LOCKDEP && !LOCKDEP_SMALL     1533         depends on LOCKDEP && !LOCKDEP_SMALL
1534         range 10 30                              1534         range 10 30
1535         default 14                               1535         default 14
1536         help                                     1536         help
1537           Try increasing this value if you ne    1537           Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1538                                                  1538 
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS               1539 config LOCKDEP_CIRCULAR_QUEUE_BITS
1540         int "Bitsize for elements in circular    1540         int "Bitsize for elements in circular_queue struct"
1541         depends on LOCKDEP                       1541         depends on LOCKDEP
1542         range 10 30                              1542         range 10 30
1543         default 12                               1543         default 12
1544         help                                     1544         help
1545           Try increasing this value if you hi    1545           Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1546                                                  1546 
1547 config DEBUG_LOCKDEP                             1547 config DEBUG_LOCKDEP
1548         bool "Lock dependency engine debuggin    1548         bool "Lock dependency engine debugging"
1549         depends on DEBUG_KERNEL && LOCKDEP       1549         depends on DEBUG_KERNEL && LOCKDEP
1550         select DEBUG_IRQFLAGS                    1550         select DEBUG_IRQFLAGS
1551         help                                     1551         help
1552           If you say Y here, the lock depende    1552           If you say Y here, the lock dependency engine will do
1553           additional runtime checks to debug     1553           additional runtime checks to debug itself, at the price
1554           of more runtime overhead.              1554           of more runtime overhead.
1555                                                  1555 
1556 config DEBUG_ATOMIC_SLEEP                        1556 config DEBUG_ATOMIC_SLEEP
1557         bool "Sleep inside atomic section che    1557         bool "Sleep inside atomic section checking"
1558         select PREEMPT_COUNT                     1558         select PREEMPT_COUNT
1559         depends on DEBUG_KERNEL                  1559         depends on DEBUG_KERNEL
1560         depends on !ARCH_NO_PREEMPT              1560         depends on !ARCH_NO_PREEMPT
1561         help                                     1561         help
1562           If you say Y here, various routines    1562           If you say Y here, various routines which may sleep will become very
1563           noisy if they are called inside ato    1563           noisy if they are called inside atomic sections: when a spinlock is
1564           held, inside an rcu read side criti    1564           held, inside an rcu read side critical section, inside preempt disabled
1565           sections, inside an interrupt, etc.    1565           sections, inside an interrupt, etc...
1566                                                  1566 
1567 config DEBUG_LOCKING_API_SELFTESTS               1567 config DEBUG_LOCKING_API_SELFTESTS
1568         bool "Locking API boot-time self-test    1568         bool "Locking API boot-time self-tests"
1569         depends on DEBUG_KERNEL                  1569         depends on DEBUG_KERNEL
1570         help                                     1570         help
1571           Say Y here if you want the kernel t    1571           Say Y here if you want the kernel to run a short self-test during
1572           bootup. The self-test checks whethe    1572           bootup. The self-test checks whether common types of locking bugs
1573           are detected by debugging mechanism    1573           are detected by debugging mechanisms or not. (if you disable
1574           lock debugging then those bugs won'    1574           lock debugging then those bugs won't be detected of course.)
1575           The following locking APIs are cove    1575           The following locking APIs are covered: spinlocks, rwlocks,
1576           mutexes and rwsems.                    1576           mutexes and rwsems.
1577                                                  1577 
1578 config LOCK_TORTURE_TEST                         1578 config LOCK_TORTURE_TEST
1579         tristate "torture tests for locking"     1579         tristate "torture tests for locking"
1580         depends on DEBUG_KERNEL                  1580         depends on DEBUG_KERNEL
1581         select TORTURE_TEST                      1581         select TORTURE_TEST
1582         help                                     1582         help
1583           This option provides a kernel modul    1583           This option provides a kernel module that runs torture tests
1584           on kernel locking primitives.  The     1584           on kernel locking primitives.  The kernel module may be built
1585           after the fact on the running kerne    1585           after the fact on the running kernel to be tested, if desired.
1586                                                  1586 
1587           Say Y here if you want kernel locki    1587           Say Y here if you want kernel locking-primitive torture tests
1588           to be built into the kernel.           1588           to be built into the kernel.
1589           Say M if you want these torture tes    1589           Say M if you want these torture tests to build as a module.
1590           Say N if you are unsure.               1590           Say N if you are unsure.
1591                                                  1591 
1592 config WW_MUTEX_SELFTEST                         1592 config WW_MUTEX_SELFTEST
1593         tristate "Wait/wound mutex selftests"    1593         tristate "Wait/wound mutex selftests"
1594         help                                     1594         help
1595           This option provides a kernel modul    1595           This option provides a kernel module that runs tests on the
1596           on the struct ww_mutex locking API.    1596           on the struct ww_mutex locking API.
1597                                                  1597 
1598           It is recommended to enable DEBUG_W    1598           It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599           with this test harness.                1599           with this test harness.
1600                                                  1600 
1601           Say M if you want these self tests     1601           Say M if you want these self tests to build as a module.
1602           Say N if you are unsure.               1602           Say N if you are unsure.
1603                                                  1603 
1604 config SCF_TORTURE_TEST                          1604 config SCF_TORTURE_TEST
1605         tristate "torture tests for smp_call_    1605         tristate "torture tests for smp_call_function*()"
1606         depends on DEBUG_KERNEL                  1606         depends on DEBUG_KERNEL
1607         select TORTURE_TEST                      1607         select TORTURE_TEST
1608         help                                     1608         help
1609           This option provides a kernel modul    1609           This option provides a kernel module that runs torture tests
1610           on the smp_call_function() family o    1610           on the smp_call_function() family of primitives.  The kernel
1611           module may be built after the fact     1611           module may be built after the fact on the running kernel to
1612           be tested, if desired.                 1612           be tested, if desired.
1613                                                  1613 
1614 config CSD_LOCK_WAIT_DEBUG                       1614 config CSD_LOCK_WAIT_DEBUG
1615         bool "Debugging for csd_lock_wait(),     1615         bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616         depends on DEBUG_KERNEL                  1616         depends on DEBUG_KERNEL
1617         depends on 64BIT                         1617         depends on 64BIT
1618         default n                                1618         default n
1619         help                                     1619         help
1620           This option enables debug prints wh    1620           This option enables debug prints when CPUs are slow to respond
1621           to the smp_call_function*() IPI wra    1621           to the smp_call_function*() IPI wrappers.  These debug prints
1622           include the IPI handler function cu    1622           include the IPI handler function currently executing (if any)
1623           and relevant stack traces.             1623           and relevant stack traces.
1624                                                  1624 
1625 config CSD_LOCK_WAIT_DEBUG_DEFAULT               1625 config CSD_LOCK_WAIT_DEBUG_DEFAULT
1626         bool "Default csd_lock_wait() debuggi    1626         bool "Default csd_lock_wait() debugging on at boot time"
1627         depends on CSD_LOCK_WAIT_DEBUG           1627         depends on CSD_LOCK_WAIT_DEBUG
1628         depends on 64BIT                         1628         depends on 64BIT
1629         default n                                1629         default n
1630         help                                     1630         help
1631           This option causes the csdlock_debu    1631           This option causes the csdlock_debug= kernel boot parameter to
1632           default to 1 (basic debugging) inst    1632           default to 1 (basic debugging) instead of 0 (no debugging).
1633                                                  1633 
1634 endmenu # lock debugging                         1634 endmenu # lock debugging
1635                                                  1635 
1636 config TRACE_IRQFLAGS                            1636 config TRACE_IRQFLAGS
1637         depends on TRACE_IRQFLAGS_SUPPORT        1637         depends on TRACE_IRQFLAGS_SUPPORT
1638         bool                                     1638         bool
1639         help                                     1639         help
1640           Enables hooks to interrupt enabling    1640           Enables hooks to interrupt enabling and disabling for
1641           either tracing or lock debugging.      1641           either tracing or lock debugging.
1642                                                  1642 
1643 config TRACE_IRQFLAGS_NMI                        1643 config TRACE_IRQFLAGS_NMI
1644         def_bool y                               1644         def_bool y
1645         depends on TRACE_IRQFLAGS                1645         depends on TRACE_IRQFLAGS
1646         depends on TRACE_IRQFLAGS_NMI_SUPPORT    1646         depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647                                                  1647 
1648 config NMI_CHECK_CPU                             1648 config NMI_CHECK_CPU
1649         bool "Debugging for CPUs failing to r    1649         bool "Debugging for CPUs failing to respond to backtrace requests"
1650         depends on DEBUG_KERNEL                  1650         depends on DEBUG_KERNEL
1651         depends on X86                           1651         depends on X86
1652         default n                                1652         default n
1653         help                                     1653         help
1654           Enables debug prints when a CPU fai    1654           Enables debug prints when a CPU fails to respond to a given
1655           backtrace NMI.  These prints provid    1655           backtrace NMI.  These prints provide some reasons why a CPU
1656           might legitimately be failing to re    1656           might legitimately be failing to respond, for example, if it
1657           is offline of if ignore_nmis is set    1657           is offline of if ignore_nmis is set.
1658                                                  1658 
1659 config DEBUG_IRQFLAGS                            1659 config DEBUG_IRQFLAGS
1660         bool "Debug IRQ flag manipulation"       1660         bool "Debug IRQ flag manipulation"
1661         help                                     1661         help
1662           Enables checks for potentially unsa    1662           Enables checks for potentially unsafe enabling or disabling of
1663           interrupts, such as calling raw_loc    1663           interrupts, such as calling raw_local_irq_restore() when interrupts
1664           are enabled.                           1664           are enabled.
1665                                                  1665 
1666 config STACKTRACE                                1666 config STACKTRACE
1667         bool "Stack backtrace support"           1667         bool "Stack backtrace support"
1668         depends on STACKTRACE_SUPPORT            1668         depends on STACKTRACE_SUPPORT
1669         help                                     1669         help
1670           This option causes the kernel to cr    1670           This option causes the kernel to create a /proc/pid/stack for
1671           every process, showing its current     1671           every process, showing its current stack trace.
1672           It is also used by various kernel d    1672           It is also used by various kernel debugging features that require
1673           stack trace generation.                1673           stack trace generation.
1674                                                  1674 
1675 config WARN_ALL_UNSEEDED_RANDOM                  1675 config WARN_ALL_UNSEEDED_RANDOM
1676         bool "Warn for all uses of unseeded r    1676         bool "Warn for all uses of unseeded randomness"
1677         default n                                1677         default n
1678         help                                     1678         help
1679           Some parts of the kernel contain bu    1679           Some parts of the kernel contain bugs relating to their use of
1680           cryptographically secure random num    1680           cryptographically secure random numbers before it's actually possible
1681           to generate those numbers securely.    1681           to generate those numbers securely. This setting ensures that these
1682           flaws don't go unnoticed, by enabli    1682           flaws don't go unnoticed, by enabling a message, should this ever
1683           occur. This will allow people with     1683           occur. This will allow people with obscure setups to know when things
1684           are going wrong, so that they might    1684           are going wrong, so that they might contact developers about fixing
1685           it.                                    1685           it.
1686                                                  1686 
1687           Unfortunately, on some models of so    1687           Unfortunately, on some models of some architectures getting
1688           a fully seeded CRNG is extremely di    1688           a fully seeded CRNG is extremely difficult, and so this can
1689           result in dmesg getting spammed for    1689           result in dmesg getting spammed for a surprisingly long
1690           time.  This is really bad from a se    1690           time.  This is really bad from a security perspective, and
1691           so architecture maintainers really     1691           so architecture maintainers really need to do what they can
1692           to get the CRNG seeded sooner after    1692           to get the CRNG seeded sooner after the system is booted.
1693           However, since users cannot do anyt    1693           However, since users cannot do anything actionable to
1694           address this, by default this optio    1694           address this, by default this option is disabled.
1695                                                  1695 
1696           Say Y here if you want to receive w    1696           Say Y here if you want to receive warnings for all uses of
1697           unseeded randomness.  This will be     1697           unseeded randomness.  This will be of use primarily for
1698           those developers interested in impr    1698           those developers interested in improving the security of
1699           Linux kernels running on their arch    1699           Linux kernels running on their architecture (or
1700           subarchitecture).                      1700           subarchitecture).
1701                                                  1701 
1702 config DEBUG_KOBJECT                             1702 config DEBUG_KOBJECT
1703         bool "kobject debugging"                 1703         bool "kobject debugging"
1704         depends on DEBUG_KERNEL                  1704         depends on DEBUG_KERNEL
1705         help                                     1705         help
1706           If you say Y here, some extra kobje    1706           If you say Y here, some extra kobject debugging messages will be sent
1707           to the syslog.                         1707           to the syslog.
1708                                                  1708 
1709 config DEBUG_KOBJECT_RELEASE                     1709 config DEBUG_KOBJECT_RELEASE
1710         bool "kobject release debugging"         1710         bool "kobject release debugging"
1711         depends on DEBUG_OBJECTS_TIMERS          1711         depends on DEBUG_OBJECTS_TIMERS
1712         help                                     1712         help
1713           kobjects are reference counted obje    1713           kobjects are reference counted objects.  This means that their
1714           last reference count put is not pre    1714           last reference count put is not predictable, and the kobject can
1715           live on past the point at which a d    1715           live on past the point at which a driver decides to drop its
1716           initial reference to the kobject ga    1716           initial reference to the kobject gained on allocation.  An
1717           example of this would be a struct d    1717           example of this would be a struct device which has just been
1718           unregistered.                          1718           unregistered.
1719                                                  1719 
1720           However, some buggy drivers assume     1720           However, some buggy drivers assume that after such an operation,
1721           the memory backing the kobject can     1721           the memory backing the kobject can be immediately freed.  This
1722           goes completely against the princip    1722           goes completely against the principles of a refcounted object.
1723                                                  1723 
1724           If you say Y here, the kernel will     1724           If you say Y here, the kernel will delay the release of kobjects
1725           on the last reference count to impr    1725           on the last reference count to improve the visibility of this
1726           kind of kobject release bug.           1726           kind of kobject release bug.
1727                                                  1727 
1728 config HAVE_DEBUG_BUGVERBOSE                     1728 config HAVE_DEBUG_BUGVERBOSE
1729         bool                                     1729         bool
1730                                                  1730 
1731 menu "Debug kernel data structures"              1731 menu "Debug kernel data structures"
1732                                                  1732 
1733 config DEBUG_LIST                                1733 config DEBUG_LIST
1734         bool "Debug linked list manipulation"    1734         bool "Debug linked list manipulation"
1735         depends on DEBUG_KERNEL                  1735         depends on DEBUG_KERNEL
1736         select LIST_HARDENED                     1736         select LIST_HARDENED
1737         help                                     1737         help
1738           Enable this to turn on extended che    1738           Enable this to turn on extended checks in the linked-list walking
1739           routines.                              1739           routines.
1740                                                  1740 
1741           This option trades better quality e    1741           This option trades better quality error reports for performance, and
1742           is more suitable for kernel debuggi    1742           is more suitable for kernel debugging. If you care about performance,
1743           you should only enable CONFIG_LIST_    1743           you should only enable CONFIG_LIST_HARDENED instead.
1744                                                  1744 
1745           If unsure, say N.                      1745           If unsure, say N.
1746                                                  1746 
1747 config DEBUG_PLIST                               1747 config DEBUG_PLIST
1748         bool "Debug priority linked list mani    1748         bool "Debug priority linked list manipulation"
1749         depends on DEBUG_KERNEL                  1749         depends on DEBUG_KERNEL
1750         help                                     1750         help
1751           Enable this to turn on extended che    1751           Enable this to turn on extended checks in the priority-ordered
1752           linked-list (plist) walking routine    1752           linked-list (plist) walking routines.  This checks the entire
1753           list multiple times during each man    1753           list multiple times during each manipulation.
1754                                                  1754 
1755           If unsure, say N.                      1755           If unsure, say N.
1756                                                  1756 
1757 config DEBUG_SG                                  1757 config DEBUG_SG
1758         bool "Debug SG table operations"         1758         bool "Debug SG table operations"
1759         depends on DEBUG_KERNEL                  1759         depends on DEBUG_KERNEL
1760         help                                     1760         help
1761           Enable this to turn on checks on sc    1761           Enable this to turn on checks on scatter-gather tables. This can
1762           help find problems with drivers tha    1762           help find problems with drivers that do not properly initialize
1763           their sg tables.                       1763           their sg tables.
1764                                                  1764 
1765           If unsure, say N.                      1765           If unsure, say N.
1766                                                  1766 
1767 config DEBUG_NOTIFIERS                           1767 config DEBUG_NOTIFIERS
1768         bool "Debug notifier call chains"        1768         bool "Debug notifier call chains"
1769         depends on DEBUG_KERNEL                  1769         depends on DEBUG_KERNEL
1770         help                                     1770         help
1771           Enable this to turn on sanity check    1771           Enable this to turn on sanity checking for notifier call chains.
1772           This is most useful for kernel deve    1772           This is most useful for kernel developers to make sure that
1773           modules properly unregister themsel    1773           modules properly unregister themselves from notifier chains.
1774           This is a relatively cheap check bu    1774           This is a relatively cheap check but if you care about maximum
1775           performance, say N.                    1775           performance, say N.
1776                                                  1776 
1777 config DEBUG_CLOSURES                            1777 config DEBUG_CLOSURES
1778         bool "Debug closures (bcache async wi    1778         bool "Debug closures (bcache async widgits)"
1779         depends on CLOSURES                      1779         depends on CLOSURES
1780         select DEBUG_FS                          1780         select DEBUG_FS
1781         help                                     1781         help
1782           Keeps all active closures in a link    1782           Keeps all active closures in a linked list and provides a debugfs
1783           interface to list them, which makes    1783           interface to list them, which makes it possible to see asynchronous
1784           operations that get stuck.             1784           operations that get stuck.
1785                                                  1785 
1786 config DEBUG_MAPLE_TREE                          1786 config DEBUG_MAPLE_TREE
1787         bool "Debug maple trees"                 1787         bool "Debug maple trees"
1788         depends on DEBUG_KERNEL                  1788         depends on DEBUG_KERNEL
1789         help                                     1789         help
1790           Enable maple tree debugging informa    1790           Enable maple tree debugging information and extra validations.
1791                                                  1791 
1792           If unsure, say N.                      1792           If unsure, say N.
1793                                                  1793 
1794 endmenu                                          1794 endmenu
1795                                                  1795 
1796 source "kernel/rcu/Kconfig.debug"                1796 source "kernel/rcu/Kconfig.debug"
1797                                                  1797 
1798 config DEBUG_WQ_FORCE_RR_CPU                     1798 config DEBUG_WQ_FORCE_RR_CPU
1799         bool "Force round-robin CPU selection    1799         bool "Force round-robin CPU selection for unbound work items"
1800         depends on DEBUG_KERNEL                  1800         depends on DEBUG_KERNEL
1801         default n                                1801         default n
1802         help                                     1802         help
1803           Workqueue used to implicitly guaran    1803           Workqueue used to implicitly guarantee that work items queued
1804           without explicit CPU specified are     1804           without explicit CPU specified are put on the local CPU.  This
1805           guarantee is no longer true and whi    1805           guarantee is no longer true and while local CPU is still
1806           preferred work items may be put on     1806           preferred work items may be put on foreign CPUs.  Kernel
1807           parameter "workqueue.debug_force_rr    1807           parameter "workqueue.debug_force_rr_cpu" is added to force
1808           round-robin CPU selection to flush     1808           round-robin CPU selection to flush out usages which depend on the
1809           now broken guarantee.  This config     1809           now broken guarantee.  This config option enables the debug
1810           feature by default.  When enabled,     1810           feature by default.  When enabled, memory and cache locality will
1811           be impacted.                           1811           be impacted.
1812                                                  1812 
1813 config CPU_HOTPLUG_STATE_CONTROL                 1813 config CPU_HOTPLUG_STATE_CONTROL
1814         bool "Enable CPU hotplug state contro    1814         bool "Enable CPU hotplug state control"
1815         depends on DEBUG_KERNEL                  1815         depends on DEBUG_KERNEL
1816         depends on HOTPLUG_CPU                   1816         depends on HOTPLUG_CPU
1817         default n                                1817         default n
1818         help                                     1818         help
1819           Allows to write steps between "offl    1819           Allows to write steps between "offline" and "online" to the CPUs
1820           sysfs target file so states can be     1820           sysfs target file so states can be stepped granular. This is a debug
1821           option for now as the hotplug machi    1821           option for now as the hotplug machinery cannot be stopped and
1822           restarted at arbitrary points yet.     1822           restarted at arbitrary points yet.
1823                                                  1823 
1824           Say N if your are unsure.              1824           Say N if your are unsure.
1825                                                  1825 
1826 config LATENCYTOP                                1826 config LATENCYTOP
1827         bool "Latency measuring infrastructur    1827         bool "Latency measuring infrastructure"
1828         depends on DEBUG_KERNEL                  1828         depends on DEBUG_KERNEL
1829         depends on STACKTRACE_SUPPORT            1829         depends on STACKTRACE_SUPPORT
1830         depends on PROC_FS                       1830         depends on PROC_FS
1831         depends on FRAME_POINTER || MIPS || P    1831         depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832         select KALLSYMS                          1832         select KALLSYMS
1833         select KALLSYMS_ALL                      1833         select KALLSYMS_ALL
1834         select STACKTRACE                        1834         select STACKTRACE
1835         select SCHEDSTATS                        1835         select SCHEDSTATS
1836         help                                     1836         help
1837           Enable this option if you want to u    1837           Enable this option if you want to use the LatencyTOP tool
1838           to find out which userspace is bloc    1838           to find out which userspace is blocking on what kernel operations.
1839                                                  1839 
1840 config DEBUG_CGROUP_REF                          1840 config DEBUG_CGROUP_REF
1841         bool "Disable inlining of cgroup css     1841         bool "Disable inlining of cgroup css reference count functions"
1842         depends on DEBUG_KERNEL                  1842         depends on DEBUG_KERNEL
1843         depends on CGROUPS                       1843         depends on CGROUPS
1844         depends on KPROBES                       1844         depends on KPROBES
1845         default n                                1845         default n
1846         help                                     1846         help
1847           Force cgroup css reference count fu    1847           Force cgroup css reference count functions to not be inlined so
1848           that they can be kprobed for debugg    1848           that they can be kprobed for debugging.
1849                                                  1849 
1850 source "kernel/trace/Kconfig"                    1850 source "kernel/trace/Kconfig"
1851                                                  1851 
1852 config PROVIDE_OHCI1394_DMA_INIT                 1852 config PROVIDE_OHCI1394_DMA_INIT
1853         bool "Remote debugging over FireWire     1853         bool "Remote debugging over FireWire early on boot"
1854         depends on PCI && X86                    1854         depends on PCI && X86
1855         help                                     1855         help
1856           If you want to debug problems which    1856           If you want to debug problems which hang or crash the kernel early
1857           on boot and the crashing machine ha    1857           on boot and the crashing machine has a FireWire port, you can use
1858           this feature to remotely access the    1858           this feature to remotely access the memory of the crashed machine
1859           over FireWire. This employs remote     1859           over FireWire. This employs remote DMA as part of the OHCI1394
1860           specification which is now the stan    1860           specification which is now the standard for FireWire controllers.
1861                                                  1861 
1862           With remote DMA, you can monitor th    1862           With remote DMA, you can monitor the printk buffer remotely using
1863           firescope and access all memory bel    1863           firescope and access all memory below 4GB using fireproxy from gdb.
1864           Even controlling a kernel debugger     1864           Even controlling a kernel debugger is possible using remote DMA.
1865                                                  1865 
1866           Usage:                                 1866           Usage:
1867                                                  1867 
1868           If ohci1394_dma=early is used as bo    1868           If ohci1394_dma=early is used as boot parameter, it will initialize
1869           all OHCI1394 controllers which are     1869           all OHCI1394 controllers which are found in the PCI config space.
1870                                                  1870 
1871           As all changes to the FireWire bus     1871           As all changes to the FireWire bus such as enabling and disabling
1872           devices cause a bus reset and there    1872           devices cause a bus reset and thereby disable remote DMA for all
1873           devices, be sure to have the cable     1873           devices, be sure to have the cable plugged and FireWire enabled on
1874           the debugging host before booting t    1874           the debugging host before booting the debug target for debugging.
1875                                                  1875 
1876           This code (~1k) is freed after boot    1876           This code (~1k) is freed after boot. By then, the firewire stack
1877           in charge of the OHCI-1394 controll    1877           in charge of the OHCI-1394 controllers should be used instead.
1878                                                  1878 
1879           See Documentation/core-api/debuggin    1879           See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880                                                  1880 
1881 source "samples/Kconfig"                         1881 source "samples/Kconfig"
1882                                                  1882 
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED                1883 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884         bool                                     1884         bool
1885                                                  1885 
1886 config STRICT_DEVMEM                             1886 config STRICT_DEVMEM
1887         bool "Filter access to /dev/mem"         1887         bool "Filter access to /dev/mem"
1888         depends on MMU && DEVMEM                 1888         depends on MMU && DEVMEM
1889         depends on ARCH_HAS_DEVMEM_IS_ALLOWED    1889         depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1890         default y if PPC || X86 || ARM64         1890         default y if PPC || X86 || ARM64
1891         help                                     1891         help
1892           If this option is disabled, you all    1892           If this option is disabled, you allow userspace (root) access to all
1893           of memory, including kernel and use    1893           of memory, including kernel and userspace memory. Accidental
1894           access to this is obviously disastr    1894           access to this is obviously disastrous, but specific access can
1895           be used by people debugging the ker    1895           be used by people debugging the kernel. Note that with PAT support
1896           enabled, even in this case there ar    1896           enabled, even in this case there are restrictions on /dev/mem
1897           use due to the cache aliasing requi    1897           use due to the cache aliasing requirements.
1898                                                  1898 
1899           If this option is switched on, and     1899           If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900           file only allows userspace access t    1900           file only allows userspace access to PCI space and the BIOS code and
1901           data regions.  This is sufficient f    1901           data regions.  This is sufficient for dosemu and X and all common
1902           users of /dev/mem.                     1902           users of /dev/mem.
1903                                                  1903 
1904           If in doubt, say Y.                    1904           If in doubt, say Y.
1905                                                  1905 
1906 config IO_STRICT_DEVMEM                          1906 config IO_STRICT_DEVMEM
1907         bool "Filter I/O access to /dev/mem"     1907         bool "Filter I/O access to /dev/mem"
1908         depends on STRICT_DEVMEM                 1908         depends on STRICT_DEVMEM
1909         help                                     1909         help
1910           If this option is disabled, you all    1910           If this option is disabled, you allow userspace (root) access to all
1911           io-memory regardless of whether a d    1911           io-memory regardless of whether a driver is actively using that
1912           range.  Accidental access to this i    1912           range.  Accidental access to this is obviously disastrous, but
1913           specific access can be used by peop    1913           specific access can be used by people debugging kernel drivers.
1914                                                  1914 
1915           If this option is switched on, the     1915           If this option is switched on, the /dev/mem file only allows
1916           userspace access to *idle* io-memor    1916           userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917           may break traditional users of /dev    1917           may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918           if the driver using a given range c    1918           if the driver using a given range cannot be disabled.
1919                                                  1919 
1920           If in doubt, say Y.                    1920           If in doubt, say Y.
1921                                                  1921 
1922 menu "$(SRCARCH) Debugging"                      1922 menu "$(SRCARCH) Debugging"
1923                                                  1923 
1924 source "arch/$(SRCARCH)/Kconfig.debug"           1924 source "arch/$(SRCARCH)/Kconfig.debug"
1925                                                  1925 
1926 endmenu                                          1926 endmenu
1927                                                  1927 
1928 menu "Kernel Testing and Coverage"               1928 menu "Kernel Testing and Coverage"
1929                                                  1929 
1930 source "lib/kunit/Kconfig"                       1930 source "lib/kunit/Kconfig"
1931                                                  1931 
1932 config NOTIFIER_ERROR_INJECTION                  1932 config NOTIFIER_ERROR_INJECTION
1933         tristate "Notifier error injection"      1933         tristate "Notifier error injection"
1934         depends on DEBUG_KERNEL                  1934         depends on DEBUG_KERNEL
1935         select DEBUG_FS                          1935         select DEBUG_FS
1936         help                                     1936         help
1937           This option provides the ability to    1937           This option provides the ability to inject artificial errors to
1938           specified notifier chain callbacks.    1938           specified notifier chain callbacks. It is useful to test the error
1939           handling of notifier call chain fai    1939           handling of notifier call chain failures.
1940                                                  1940 
1941           Say N if unsure.                       1941           Say N if unsure.
1942                                                  1942 
1943 config PM_NOTIFIER_ERROR_INJECT                  1943 config PM_NOTIFIER_ERROR_INJECT
1944         tristate "PM notifier error injection    1944         tristate "PM notifier error injection module"
1945         depends on PM && NOTIFIER_ERROR_INJEC    1945         depends on PM && NOTIFIER_ERROR_INJECTION
1946         default m if PM_DEBUG                    1946         default m if PM_DEBUG
1947         help                                     1947         help
1948           This option provides the ability to    1948           This option provides the ability to inject artificial errors to
1949           PM notifier chain callbacks.  It is    1949           PM notifier chain callbacks.  It is controlled through debugfs
1950           interface /sys/kernel/debug/notifie    1950           interface /sys/kernel/debug/notifier-error-inject/pm
1951                                                  1951 
1952           If the notifier call chain should b    1952           If the notifier call chain should be failed with some events
1953           notified, write the error code to "    1953           notified, write the error code to "actions/<notifier event>/error".
1954                                                  1954 
1955           Example: Inject PM suspend error (-    1955           Example: Inject PM suspend error (-12 = -ENOMEM)
1956                                                  1956 
1957           # cd /sys/kernel/debug/notifier-err    1957           # cd /sys/kernel/debug/notifier-error-inject/pm/
1958           # echo -12 > actions/PM_SUSPEND_PRE    1958           # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959           # echo mem > /sys/power/state          1959           # echo mem > /sys/power/state
1960           bash: echo: write error: Cannot all    1960           bash: echo: write error: Cannot allocate memory
1961                                                  1961 
1962           To compile this code as a module, c    1962           To compile this code as a module, choose M here: the module will
1963           be called pm-notifier-error-inject.    1963           be called pm-notifier-error-inject.
1964                                                  1964 
1965           If unsure, say N.                      1965           If unsure, say N.
1966                                                  1966 
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT         1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968         tristate "OF reconfig notifier error     1968         tristate "OF reconfig notifier error injection module"
1969         depends on OF_DYNAMIC && NOTIFIER_ERR    1969         depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970         help                                     1970         help
1971           This option provides the ability to    1971           This option provides the ability to inject artificial errors to
1972           OF reconfig notifier chain callback    1972           OF reconfig notifier chain callbacks.  It is controlled
1973           through debugfs interface under        1973           through debugfs interface under
1974           /sys/kernel/debug/notifier-error-in    1974           /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975                                                  1975 
1976           If the notifier call chain should b    1976           If the notifier call chain should be failed with some events
1977           notified, write the error code to "    1977           notified, write the error code to "actions/<notifier event>/error".
1978                                                  1978 
1979           To compile this code as a module, c    1979           To compile this code as a module, choose M here: the module will
1980           be called of-reconfig-notifier-erro    1980           be called of-reconfig-notifier-error-inject.
1981                                                  1981 
1982           If unsure, say N.                      1982           If unsure, say N.
1983                                                  1983 
1984 config NETDEV_NOTIFIER_ERROR_INJECT              1984 config NETDEV_NOTIFIER_ERROR_INJECT
1985         tristate "Netdev notifier error injec    1985         tristate "Netdev notifier error injection module"
1986         depends on NET && NOTIFIER_ERROR_INJE    1986         depends on NET && NOTIFIER_ERROR_INJECTION
1987         help                                     1987         help
1988           This option provides the ability to    1988           This option provides the ability to inject artificial errors to
1989           netdevice notifier chain callbacks.    1989           netdevice notifier chain callbacks.  It is controlled through debugfs
1990           interface /sys/kernel/debug/notifie    1990           interface /sys/kernel/debug/notifier-error-inject/netdev
1991                                                  1991 
1992           If the notifier call chain should b    1992           If the notifier call chain should be failed with some events
1993           notified, write the error code to "    1993           notified, write the error code to "actions/<notifier event>/error".
1994                                                  1994 
1995           Example: Inject netdevice mtu chang    1995           Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996                                                  1996 
1997           # cd /sys/kernel/debug/notifier-err    1997           # cd /sys/kernel/debug/notifier-error-inject/netdev
1998           # echo -22 > actions/NETDEV_CHANGEM    1998           # echo -22 > actions/NETDEV_CHANGEMTU/error
1999           # ip link set eth0 mtu 1024            1999           # ip link set eth0 mtu 1024
2000           RTNETLINK answers: Invalid argument    2000           RTNETLINK answers: Invalid argument
2001                                                  2001 
2002           To compile this code as a module, c    2002           To compile this code as a module, choose M here: the module will
2003           be called netdev-notifier-error-inj    2003           be called netdev-notifier-error-inject.
2004                                                  2004 
2005           If unsure, say N.                      2005           If unsure, say N.
2006                                                  2006 
2007 config FUNCTION_ERROR_INJECTION                  2007 config FUNCTION_ERROR_INJECTION
2008         bool "Fault-injections of functions"     2008         bool "Fault-injections of functions"
2009         depends on HAVE_FUNCTION_ERROR_INJECT    2009         depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010         help                                     2010         help
2011           Add fault injections into various f    2011           Add fault injections into various functions that are annotated with
2012           ALLOW_ERROR_INJECTION() in the kern    2012           ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
2013           value of these functions. This is u    2013           value of these functions. This is useful to test error paths of code.
2014                                                  2014 
2015           If unsure, say N                       2015           If unsure, say N
2016                                                  2016 
2017 config FAULT_INJECTION                           2017 config FAULT_INJECTION
2018         bool "Fault-injection framework"         2018         bool "Fault-injection framework"
2019         depends on DEBUG_KERNEL                  2019         depends on DEBUG_KERNEL
2020         help                                     2020         help
2021           Provide fault-injection framework.     2021           Provide fault-injection framework.
2022           For more details, see Documentation    2022           For more details, see Documentation/fault-injection/.
2023                                                  2023 
2024 config FAILSLAB                                  2024 config FAILSLAB
2025         bool "Fault-injection capability for     2025         bool "Fault-injection capability for kmalloc"
2026         depends on FAULT_INJECTION               2026         depends on FAULT_INJECTION
2027         help                                     2027         help
2028           Provide fault-injection capability     2028           Provide fault-injection capability for kmalloc.
2029                                                  2029 
2030 config FAIL_PAGE_ALLOC                           2030 config FAIL_PAGE_ALLOC
2031         bool "Fault-injection capability for     2031         bool "Fault-injection capability for alloc_pages()"
2032         depends on FAULT_INJECTION               2032         depends on FAULT_INJECTION
2033         help                                     2033         help
2034           Provide fault-injection capability     2034           Provide fault-injection capability for alloc_pages().
2035                                                  2035 
2036 config FAULT_INJECTION_USERCOPY                  2036 config FAULT_INJECTION_USERCOPY
2037         bool "Fault injection capability for     2037         bool "Fault injection capability for usercopy functions"
2038         depends on FAULT_INJECTION               2038         depends on FAULT_INJECTION
2039         help                                     2039         help
2040           Provides fault-injection capability    2040           Provides fault-injection capability to inject failures
2041           in usercopy functions (copy_from_us    2041           in usercopy functions (copy_from_user(), get_user(), ...).
2042                                                  2042 
2043 config FAIL_MAKE_REQUEST                         2043 config FAIL_MAKE_REQUEST
2044         bool "Fault-injection capability for     2044         bool "Fault-injection capability for disk IO"
2045         depends on FAULT_INJECTION && BLOCK      2045         depends on FAULT_INJECTION && BLOCK
2046         help                                     2046         help
2047           Provide fault-injection capability     2047           Provide fault-injection capability for disk IO.
2048                                                  2048 
2049 config FAIL_IO_TIMEOUT                           2049 config FAIL_IO_TIMEOUT
2050         bool "Fault-injection capability for     2050         bool "Fault-injection capability for faking disk interrupts"
2051         depends on FAULT_INJECTION && BLOCK      2051         depends on FAULT_INJECTION && BLOCK
2052         help                                     2052         help
2053           Provide fault-injection capability     2053           Provide fault-injection capability on end IO handling. This
2054           will make the block layer "forget"     2054           will make the block layer "forget" an interrupt as configured,
2055           thus exercising the error handling.    2055           thus exercising the error handling.
2056                                                  2056 
2057           Only works with drivers that use th    2057           Only works with drivers that use the generic timeout handling,
2058           for others it won't do anything.       2058           for others it won't do anything.
2059                                                  2059 
2060 config FAIL_FUTEX                                2060 config FAIL_FUTEX
2061         bool "Fault-injection capability for     2061         bool "Fault-injection capability for futexes"
2062         select DEBUG_FS                          2062         select DEBUG_FS
2063         depends on FAULT_INJECTION && FUTEX      2063         depends on FAULT_INJECTION && FUTEX
2064         help                                     2064         help
2065           Provide fault-injection capability     2065           Provide fault-injection capability for futexes.
2066                                                  2066 
2067 config FAULT_INJECTION_DEBUG_FS                  2067 config FAULT_INJECTION_DEBUG_FS
2068         bool "Debugfs entries for fault-injec    2068         bool "Debugfs entries for fault-injection capabilities"
2069         depends on FAULT_INJECTION && SYSFS &    2069         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070         help                                     2070         help
2071           Enable configuration of fault-injec    2071           Enable configuration of fault-injection capabilities via debugfs.
2072                                                  2072 
2073 config FAIL_FUNCTION                             2073 config FAIL_FUNCTION
2074         bool "Fault-injection capability for     2074         bool "Fault-injection capability for functions"
2075         depends on FAULT_INJECTION_DEBUG_FS &    2075         depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076         help                                     2076         help
2077           Provide function-based fault-inject    2077           Provide function-based fault-injection capability.
2078           This will allow you to override a s    2078           This will allow you to override a specific function with a return
2079           with given return value. As a resul    2079           with given return value. As a result, function caller will see
2080           an error value and have to handle i    2080           an error value and have to handle it. This is useful to test the
2081           error handling in various subsystem    2081           error handling in various subsystems.
2082                                                  2082 
2083 config FAIL_MMC_REQUEST                          2083 config FAIL_MMC_REQUEST
2084         bool "Fault-injection capability for     2084         bool "Fault-injection capability for MMC IO"
2085         depends on FAULT_INJECTION_DEBUG_FS &    2085         depends on FAULT_INJECTION_DEBUG_FS && MMC
2086         help                                     2086         help
2087           Provide fault-injection capability     2087           Provide fault-injection capability for MMC IO.
2088           This will make the mmc core return     2088           This will make the mmc core return data errors. This is
2089           useful to test the error handling i    2089           useful to test the error handling in the mmc block device
2090           and to test how the mmc host driver    2090           and to test how the mmc host driver handles retries from
2091           the block device.                      2091           the block device.
2092                                                  2092 
2093 config FAIL_SUNRPC                               2093 config FAIL_SUNRPC
2094         bool "Fault-injection capability for     2094         bool "Fault-injection capability for SunRPC"
2095         depends on FAULT_INJECTION_DEBUG_FS &    2095         depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2096         help                                     2096         help
2097           Provide fault-injection capability     2097           Provide fault-injection capability for SunRPC and
2098           its consumers.                         2098           its consumers.
2099                                                  2099 
2100 config FAULT_INJECTION_CONFIGFS                  2100 config FAULT_INJECTION_CONFIGFS
2101         bool "Configfs interface for fault-in    2101         bool "Configfs interface for fault-injection capabilities"
2102         depends on FAULT_INJECTION               2102         depends on FAULT_INJECTION
2103         select CONFIGFS_FS                       2103         select CONFIGFS_FS
2104         help                                     2104         help
2105           This option allows configfs-based d    2105           This option allows configfs-based drivers to dynamically configure
2106           fault-injection via configfs.  Each    2106           fault-injection via configfs.  Each parameter for driver-specific
2107           fault-injection can be made visible    2107           fault-injection can be made visible as a configfs attribute in a
2108           configfs group.                        2108           configfs group.
2109                                                  2109 
2110                                                  2110 
2111 config FAULT_INJECTION_STACKTRACE_FILTER         2111 config FAULT_INJECTION_STACKTRACE_FILTER
2112         bool "stacktrace filter for fault-inj    2112         bool "stacktrace filter for fault-injection capabilities"
2113         depends on FAULT_INJECTION               2113         depends on FAULT_INJECTION
2114         depends on (FAULT_INJECTION_DEBUG_FS     2114         depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
2115         select STACKTRACE                        2115         select STACKTRACE
2116         depends on FRAME_POINTER || MIPS || P    2116         depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117         help                                     2117         help
2118           Provide stacktrace filter for fault    2118           Provide stacktrace filter for fault-injection capabilities
2119                                                  2119 
2120 config ARCH_HAS_KCOV                             2120 config ARCH_HAS_KCOV
2121         bool                                     2121         bool
2122         help                                     2122         help
2123           An architecture should select this     2123           An architecture should select this when it can successfully
2124           build and run with CONFIG_KCOV. Thi    2124           build and run with CONFIG_KCOV. This typically requires
2125           disabling instrumentation for some     2125           disabling instrumentation for some early boot code.
2126                                                  2126 
2127 config CC_HAS_SANCOV_TRACE_PC                    2127 config CC_HAS_SANCOV_TRACE_PC
2128         def_bool $(cc-option,-fsanitize-cover    2128         def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129                                                  2129 
2130                                                  2130 
2131 config KCOV                                      2131 config KCOV
2132         bool "Code coverage for fuzzing"         2132         bool "Code coverage for fuzzing"
2133         depends on ARCH_HAS_KCOV                 2133         depends on ARCH_HAS_KCOV
2134         depends on CC_HAS_SANCOV_TRACE_PC ||     2134         depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2135         depends on !ARCH_WANTS_NO_INSTR || HA    2135         depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2136                    GCC_VERSION >= 120000 || C    2136                    GCC_VERSION >= 120000 || CC_IS_CLANG
2137         select DEBUG_FS                          2137         select DEBUG_FS
2138         select GCC_PLUGIN_SANCOV if !CC_HAS_S    2138         select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139         select OBJTOOL if HAVE_NOINSTR_HACK      2139         select OBJTOOL if HAVE_NOINSTR_HACK
2140         help                                     2140         help
2141           KCOV exposes kernel code coverage i    2141           KCOV exposes kernel code coverage information in a form suitable
2142           for coverage-guided fuzzing (random    2142           for coverage-guided fuzzing (randomized testing).
2143                                                  2143 
2144           For more details, see Documentation    2144           For more details, see Documentation/dev-tools/kcov.rst.
2145                                                  2145 
2146 config KCOV_ENABLE_COMPARISONS                   2146 config KCOV_ENABLE_COMPARISONS
2147         bool "Enable comparison operands coll    2147         bool "Enable comparison operands collection by KCOV"
2148         depends on KCOV                          2148         depends on KCOV
2149         depends on $(cc-option,-fsanitize-cov    2149         depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150         help                                     2150         help
2151           KCOV also exposes operands of every    2151           KCOV also exposes operands of every comparison in the instrumented
2152           code along with operand sizes and P    2152           code along with operand sizes and PCs of the comparison instructions.
2153           These operands can be used by fuzzi    2153           These operands can be used by fuzzing engines to improve the quality
2154           of fuzzing coverage.                   2154           of fuzzing coverage.
2155                                                  2155 
2156 config KCOV_INSTRUMENT_ALL                       2156 config KCOV_INSTRUMENT_ALL
2157         bool "Instrument all code by default"    2157         bool "Instrument all code by default"
2158         depends on KCOV                          2158         depends on KCOV
2159         default y                                2159         default y
2160         help                                     2160         help
2161           If you are doing generic system cal    2161           If you are doing generic system call fuzzing (like e.g. syzkaller),
2162           then you will want to instrument th    2162           then you will want to instrument the whole kernel and you should
2163           say y here. If you are doing more t    2163           say y here. If you are doing more targeted fuzzing (like e.g.
2164           filesystem fuzzing with AFL) then y    2164           filesystem fuzzing with AFL) then you will want to enable coverage
2165           for more specific subsets of files,    2165           for more specific subsets of files, and should say n here.
2166                                                  2166 
2167 config KCOV_IRQ_AREA_SIZE                        2167 config KCOV_IRQ_AREA_SIZE
2168         hex "Size of interrupt coverage colle    2168         hex "Size of interrupt coverage collection area in words"
2169         depends on KCOV                          2169         depends on KCOV
2170         default 0x40000                          2170         default 0x40000
2171         help                                     2171         help
2172           KCOV uses preallocated per-cpu area    2172           KCOV uses preallocated per-cpu areas to collect coverage from
2173           soft interrupts. This specifies the    2173           soft interrupts. This specifies the size of those areas in the
2174           number of unsigned long words.         2174           number of unsigned long words.
2175                                                  2175 
2176 menuconfig RUNTIME_TESTING_MENU                  2176 menuconfig RUNTIME_TESTING_MENU
2177         bool "Runtime Testing"                   2177         bool "Runtime Testing"
2178         default y                                2178         default y
2179                                                  2179 
2180 if RUNTIME_TESTING_MENU                          2180 if RUNTIME_TESTING_MENU
2181                                                  2181 
2182 config TEST_DHRY                                 2182 config TEST_DHRY
2183         tristate "Dhrystone benchmark test"      2183         tristate "Dhrystone benchmark test"
2184         help                                     2184         help
2185           Enable this to include the Dhryston    2185           Enable this to include the Dhrystone 2.1 benchmark.  This test
2186           calculates the number of Dhrystones    2186           calculates the number of Dhrystones per second, and the number of
2187           DMIPS (Dhrystone MIPS) obtained whe    2187           DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2188           by 1757 (the number of Dhrystones p    2188           by 1757 (the number of Dhrystones per second obtained on the VAX
2189           11/780, nominally a 1 MIPS machine)    2189           11/780, nominally a 1 MIPS machine).
2190                                                  2190 
2191           To run the benchmark, it needs to b    2191           To run the benchmark, it needs to be enabled explicitly, either from
2192           the kernel command line (when built    2192           the kernel command line (when built-in), or from userspace (when
2193           built-in or modular).                  2193           built-in or modular).
2194                                                  2194 
2195           Run once during kernel boot:           2195           Run once during kernel boot:
2196                                                  2196 
2197               test_dhry.run                      2197               test_dhry.run
2198                                                  2198 
2199           Set number of iterations from kerne    2199           Set number of iterations from kernel command line:
2200                                                  2200 
2201               test_dhry.iterations=<n>           2201               test_dhry.iterations=<n>
2202                                                  2202 
2203           Set number of iterations from users    2203           Set number of iterations from userspace:
2204                                                  2204 
2205               echo <n> > /sys/module/test_dhr    2205               echo <n> > /sys/module/test_dhry/parameters/iterations
2206                                                  2206 
2207           Trigger manual run from userspace:     2207           Trigger manual run from userspace:
2208                                                  2208 
2209               echo y > /sys/module/test_dhry/    2209               echo y > /sys/module/test_dhry/parameters/run
2210                                                  2210 
2211           If the number of iterations is <= 0    2211           If the number of iterations is <= 0, the test will devise a suitable
2212           number of iterations (test runs for    2212           number of iterations (test runs for at least 2s) automatically.
2213           This process takes ca. 4s.             2213           This process takes ca. 4s.
2214                                                  2214 
2215           If unsure, say N.                      2215           If unsure, say N.
2216                                                  2216 
2217 config LKDTM                                     2217 config LKDTM
2218         tristate "Linux Kernel Dump Test Tool    2218         tristate "Linux Kernel Dump Test Tool Module"
2219         depends on DEBUG_FS                      2219         depends on DEBUG_FS
2220         help                                     2220         help
2221         This module enables testing of the di    2221         This module enables testing of the different dumping mechanisms by
2222         inducing system failures at predefine    2222         inducing system failures at predefined crash points.
2223         If you don't need it: say N              2223         If you don't need it: say N
2224         Choose M here to compile this code as    2224         Choose M here to compile this code as a module. The module will be
2225         called lkdtm.                            2225         called lkdtm.
2226                                                  2226 
2227         Documentation on how to use the modul    2227         Documentation on how to use the module can be found in
2228         Documentation/fault-injection/provoke    2228         Documentation/fault-injection/provoke-crashes.rst
2229                                                  2229 
2230 config CPUMASK_KUNIT_TEST                        2230 config CPUMASK_KUNIT_TEST
2231         tristate "KUnit test for cpumask" if     2231         tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2232         depends on KUNIT                         2232         depends on KUNIT
2233         default KUNIT_ALL_TESTS                  2233         default KUNIT_ALL_TESTS
2234         help                                     2234         help
2235           Enable to turn on cpumask tests, ru    2235           Enable to turn on cpumask tests, running at boot or module load time.
2236                                                  2236 
2237           For more information on KUnit and u    2237           For more information on KUnit and unit tests in general, please refer
2238           to the KUnit documentation in Docum    2238           to the KUnit documentation in Documentation/dev-tools/kunit/.
2239                                                  2239 
2240           If unsure, say N.                      2240           If unsure, say N.
2241                                                  2241 
2242 config TEST_LIST_SORT                            2242 config TEST_LIST_SORT
2243         tristate "Linked list sorting test" i    2243         tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2244         depends on KUNIT                         2244         depends on KUNIT
2245         default KUNIT_ALL_TESTS                  2245         default KUNIT_ALL_TESTS
2246         help                                     2246         help
2247           Enable this to turn on 'list_sort()    2247           Enable this to turn on 'list_sort()' function test. This test is
2248           executed only once during system bo    2248           executed only once during system boot (so affects only boot time),
2249           or at module load time.                2249           or at module load time.
2250                                                  2250 
2251           If unsure, say N.                      2251           If unsure, say N.
2252                                                  2252 
2253 config TEST_MIN_HEAP                             2253 config TEST_MIN_HEAP
2254         tristate "Min heap test"                 2254         tristate "Min heap test"
2255         depends on DEBUG_KERNEL || m             2255         depends on DEBUG_KERNEL || m
2256         help                                     2256         help
2257           Enable this to turn on min heap fun    2257           Enable this to turn on min heap function tests. This test is
2258           executed only once during system bo    2258           executed only once during system boot (so affects only boot time),
2259           or at module load time.                2259           or at module load time.
2260                                                  2260 
2261           If unsure, say N.                      2261           If unsure, say N.
2262                                                  2262 
2263 config TEST_SORT                                 2263 config TEST_SORT
2264         tristate "Array-based sort test" if !    2264         tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2265         depends on KUNIT                         2265         depends on KUNIT
2266         default KUNIT_ALL_TESTS                  2266         default KUNIT_ALL_TESTS
2267         help                                     2267         help
2268           This option enables the self-test f    2268           This option enables the self-test function of 'sort()' at boot,
2269           or at module load time.                2269           or at module load time.
2270                                                  2270 
2271           If unsure, say N.                      2271           If unsure, say N.
2272                                                  2272 
2273 config TEST_DIV64                                2273 config TEST_DIV64
2274         tristate "64bit/32bit division and mo    2274         tristate "64bit/32bit division and modulo test"
2275         depends on DEBUG_KERNEL || m             2275         depends on DEBUG_KERNEL || m
2276         help                                     2276         help
2277           Enable this to turn on 'do_div()' f    2277           Enable this to turn on 'do_div()' function test. This test is
2278           executed only once during system bo    2278           executed only once during system boot (so affects only boot time),
2279           or at module load time.                2279           or at module load time.
2280                                                  2280 
2281           If unsure, say N.                      2281           If unsure, say N.
2282                                                  2282 
2283 config TEST_IOV_ITER                             2283 config TEST_IOV_ITER
2284         tristate "Test iov_iter operation" if    2284         tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2285         depends on KUNIT                         2285         depends on KUNIT
2286         depends on MMU                           2286         depends on MMU
2287         default KUNIT_ALL_TESTS                  2287         default KUNIT_ALL_TESTS
2288         help                                     2288         help
2289           Enable this to turn on testing of t    2289           Enable this to turn on testing of the operation of the I/O iterator
2290           (iov_iter). This test is executed o    2290           (iov_iter). This test is executed only once during system boot (so
2291           affects only boot time), or at modu    2291           affects only boot time), or at module load time.
2292                                                  2292 
2293           If unsure, say N.                      2293           If unsure, say N.
2294                                                  2294 
2295 config KPROBES_SANITY_TEST                       2295 config KPROBES_SANITY_TEST
2296         tristate "Kprobes sanity tests" if !K    2296         tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2297         depends on DEBUG_KERNEL                  2297         depends on DEBUG_KERNEL
2298         depends on KPROBES                       2298         depends on KPROBES
2299         depends on KUNIT                         2299         depends on KUNIT
2300         select STACKTRACE if ARCH_CORRECT_STA    2300         select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2301         default KUNIT_ALL_TESTS                  2301         default KUNIT_ALL_TESTS
2302         help                                     2302         help
2303           This option provides for testing ba    2303           This option provides for testing basic kprobes functionality on
2304           boot. Samples of kprobe and kretpro    2304           boot. Samples of kprobe and kretprobe are inserted and
2305           verified for functionality.            2305           verified for functionality.
2306                                                  2306 
2307           Say N if you are unsure.               2307           Say N if you are unsure.
2308                                                  2308 
2309 config FPROBE_SANITY_TEST                        2309 config FPROBE_SANITY_TEST
2310         bool "Self test for fprobe"              2310         bool "Self test for fprobe"
2311         depends on DEBUG_KERNEL                  2311         depends on DEBUG_KERNEL
2312         depends on FPROBE                        2312         depends on FPROBE
2313         depends on KUNIT=y                       2313         depends on KUNIT=y
2314         help                                     2314         help
2315           This option will enable testing the    2315           This option will enable testing the fprobe when the system boot.
2316           A series of tests are made to verif    2316           A series of tests are made to verify that the fprobe is functioning
2317           properly.                              2317           properly.
2318                                                  2318 
2319           Say N if you are unsure.               2319           Say N if you are unsure.
2320                                                  2320 
2321 config BACKTRACE_SELF_TEST                       2321 config BACKTRACE_SELF_TEST
2322         tristate "Self test for the backtrace    2322         tristate "Self test for the backtrace code"
2323         depends on DEBUG_KERNEL                  2323         depends on DEBUG_KERNEL
2324         help                                     2324         help
2325           This option provides a kernel modul    2325           This option provides a kernel module that can be used to test
2326           the kernel stack backtrace code. Th    2326           the kernel stack backtrace code. This option is not useful
2327           for distributions or general kernel    2327           for distributions or general kernels, but only for kernel
2328           developers working on architecture     2328           developers working on architecture code.
2329                                                  2329 
2330           Note that if you want to also test     2330           Note that if you want to also test saved backtraces, you will
2331           have to enable STACKTRACE as well.     2331           have to enable STACKTRACE as well.
2332                                                  2332 
2333           Say N if you are unsure.               2333           Say N if you are unsure.
2334                                                  2334 
2335 config TEST_REF_TRACKER                          2335 config TEST_REF_TRACKER
2336         tristate "Self test for reference tra    2336         tristate "Self test for reference tracker"
2337         depends on DEBUG_KERNEL && STACKTRACE    2337         depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2338         select REF_TRACKER                       2338         select REF_TRACKER
2339         help                                     2339         help
2340           This option provides a kernel modul    2340           This option provides a kernel module performing tests
2341           using reference tracker infrastruct    2341           using reference tracker infrastructure.
2342                                                  2342 
2343           Say N if you are unsure.               2343           Say N if you are unsure.
2344                                                  2344 
2345 config RBTREE_TEST                               2345 config RBTREE_TEST
2346         tristate "Red-Black tree test"           2346         tristate "Red-Black tree test"
2347         depends on DEBUG_KERNEL                  2347         depends on DEBUG_KERNEL
2348         help                                     2348         help
2349           A benchmark measuring the performan    2349           A benchmark measuring the performance of the rbtree library.
2350           Also includes rbtree invariant chec    2350           Also includes rbtree invariant checks.
2351                                                  2351 
2352 config REED_SOLOMON_TEST                         2352 config REED_SOLOMON_TEST
2353         tristate "Reed-Solomon library test"     2353         tristate "Reed-Solomon library test"
2354         depends on DEBUG_KERNEL || m             2354         depends on DEBUG_KERNEL || m
2355         select REED_SOLOMON                      2355         select REED_SOLOMON
2356         select REED_SOLOMON_ENC16                2356         select REED_SOLOMON_ENC16
2357         select REED_SOLOMON_DEC16                2357         select REED_SOLOMON_DEC16
2358         help                                     2358         help
2359           This option enables the self-test f    2359           This option enables the self-test function of rslib at boot,
2360           or at module load time.                2360           or at module load time.
2361                                                  2361 
2362           If unsure, say N.                      2362           If unsure, say N.
2363                                                  2363 
2364 config INTERVAL_TREE_TEST                        2364 config INTERVAL_TREE_TEST
2365         tristate "Interval tree test"            2365         tristate "Interval tree test"
2366         depends on DEBUG_KERNEL                  2366         depends on DEBUG_KERNEL
2367         select INTERVAL_TREE                     2367         select INTERVAL_TREE
2368         help                                     2368         help
2369           A benchmark measuring the performan    2369           A benchmark measuring the performance of the interval tree library
2370                                                  2370 
2371 config PERCPU_TEST                               2371 config PERCPU_TEST
2372         tristate "Per cpu operations test"       2372         tristate "Per cpu operations test"
2373         depends on m && DEBUG_KERNEL             2373         depends on m && DEBUG_KERNEL
2374         help                                     2374         help
2375           Enable this option to build test mo    2375           Enable this option to build test module which validates per-cpu
2376           operations.                            2376           operations.
2377                                                  2377 
2378           If unsure, say N.                      2378           If unsure, say N.
2379                                                  2379 
2380 config ATOMIC64_SELFTEST                         2380 config ATOMIC64_SELFTEST
2381         tristate "Perform an atomic64_t self-    2381         tristate "Perform an atomic64_t self-test"
2382         help                                     2382         help
2383           Enable this option to test the atom    2383           Enable this option to test the atomic64_t functions at boot or
2384           at module load time.                   2384           at module load time.
2385                                                  2385 
2386           If unsure, say N.                      2386           If unsure, say N.
2387                                                  2387 
2388 config ASYNC_RAID6_TEST                          2388 config ASYNC_RAID6_TEST
2389         tristate "Self test for hardware acce    2389         tristate "Self test for hardware accelerated raid6 recovery"
2390         depends on ASYNC_RAID6_RECOV             2390         depends on ASYNC_RAID6_RECOV
2391         select ASYNC_MEMCPY                      2391         select ASYNC_MEMCPY
2392         help                                     2392         help
2393           This is a one-shot self test that p    2393           This is a one-shot self test that permutes through the
2394           recovery of all the possible two di    2394           recovery of all the possible two disk failure scenarios for a
2395           N-disk array.  Recovery is performe    2395           N-disk array.  Recovery is performed with the asynchronous
2396           raid6 recovery routines, and will o    2396           raid6 recovery routines, and will optionally use an offload
2397           engine if one is available.            2397           engine if one is available.
2398                                                  2398 
2399           If unsure, say N.                      2399           If unsure, say N.
2400                                                  2400 
2401 config TEST_HEXDUMP                              2401 config TEST_HEXDUMP
2402         tristate "Test functions located in t    2402         tristate "Test functions located in the hexdump module at runtime"
2403                                                  2403 
2404 config STRING_KUNIT_TEST                         2404 config STRING_KUNIT_TEST
2405         tristate "KUnit test string functions    2405         tristate "KUnit test string functions at runtime" if !KUNIT_ALL_TESTS
2406         depends on KUNIT                         2406         depends on KUNIT
2407         default KUNIT_ALL_TESTS                  2407         default KUNIT_ALL_TESTS
2408                                                  2408 
2409 config STRING_HELPERS_KUNIT_TEST                 2409 config STRING_HELPERS_KUNIT_TEST
2410         tristate "KUnit test string helpers a    2410         tristate "KUnit test string helpers at runtime" if !KUNIT_ALL_TESTS
2411         depends on KUNIT                         2411         depends on KUNIT
2412         default KUNIT_ALL_TESTS                  2412         default KUNIT_ALL_TESTS
2413                                                  2413 
2414 config TEST_KSTRTOX                              2414 config TEST_KSTRTOX
2415         tristate "Test kstrto*() family of fu    2415         tristate "Test kstrto*() family of functions at runtime"
2416                                                  2416 
2417 config TEST_PRINTF                               2417 config TEST_PRINTF
2418         tristate "Test printf() family of fun    2418         tristate "Test printf() family of functions at runtime"
2419                                                  2419 
2420 config TEST_SCANF                                2420 config TEST_SCANF
2421         tristate "Test scanf() family of func    2421         tristate "Test scanf() family of functions at runtime"
2422                                                  2422 
2423 config TEST_BITMAP                               2423 config TEST_BITMAP
2424         tristate "Test bitmap_*() family of f    2424         tristate "Test bitmap_*() family of functions at runtime"
2425         help                                     2425         help
2426           Enable this option to test the bitm    2426           Enable this option to test the bitmap functions at boot.
2427                                                  2427 
2428           If unsure, say N.                      2428           If unsure, say N.
2429                                                  2429 
2430 config TEST_UUID                                 2430 config TEST_UUID
2431         tristate "Test functions located in t    2431         tristate "Test functions located in the uuid module at runtime"
2432                                                  2432 
2433 config TEST_XARRAY                               2433 config TEST_XARRAY
2434         tristate "Test the XArray code at run    2434         tristate "Test the XArray code at runtime"
2435                                                  2435 
2436 config TEST_MAPLE_TREE                           2436 config TEST_MAPLE_TREE
2437         tristate "Test the Maple Tree code at    2437         tristate "Test the Maple Tree code at runtime or module load"
2438         help                                     2438         help
2439           Enable this option to test the mapl    2439           Enable this option to test the maple tree code functions at boot, or
2440           when the module is loaded. Enable "    2440           when the module is loaded. Enable "Debug Maple Trees" will enable
2441           more verbose output on failures.       2441           more verbose output on failures.
2442                                                  2442 
2443           If unsure, say N.                      2443           If unsure, say N.
2444                                                  2444 
2445 config TEST_RHASHTABLE                           2445 config TEST_RHASHTABLE
2446         tristate "Perform selftest on resizab    2446         tristate "Perform selftest on resizable hash table"
2447         help                                     2447         help
2448           Enable this option to test the rhas    2448           Enable this option to test the rhashtable functions at boot.
2449                                                  2449 
2450           If unsure, say N.                      2450           If unsure, say N.
2451                                                  2451 
2452 config TEST_IDA                                  2452 config TEST_IDA
2453         tristate "Perform selftest on IDA fun    2453         tristate "Perform selftest on IDA functions"
2454                                                  2454 
2455 config TEST_PARMAN                               2455 config TEST_PARMAN
2456         tristate "Perform selftest on priorit    2456         tristate "Perform selftest on priority array manager"
2457         depends on PARMAN                        2457         depends on PARMAN
2458         help                                     2458         help
2459           Enable this option to test priority    2459           Enable this option to test priority array manager on boot
2460           (or module load).                      2460           (or module load).
2461                                                  2461 
2462           If unsure, say N.                      2462           If unsure, say N.
2463                                                  2463 
2464 config TEST_IRQ_TIMINGS                          2464 config TEST_IRQ_TIMINGS
2465         bool "IRQ timings selftest"              2465         bool "IRQ timings selftest"
2466         depends on IRQ_TIMINGS                   2466         depends on IRQ_TIMINGS
2467         help                                     2467         help
2468           Enable this option to test the irq     2468           Enable this option to test the irq timings code on boot.
2469                                                  2469 
2470           If unsure, say N.                      2470           If unsure, say N.
2471                                                  2471 
2472 config TEST_LKM                                  2472 config TEST_LKM
2473         tristate "Test module loading with 'h    2473         tristate "Test module loading with 'hello world' module"
2474         depends on m                             2474         depends on m
2475         help                                     2475         help
2476           This builds the "test_module" modul    2476           This builds the "test_module" module that emits "Hello, world"
2477           on printk when loaded. It is design    2477           on printk when loaded. It is designed to be used for basic
2478           evaluation of the module loading su    2478           evaluation of the module loading subsystem (for example when
2479           validating module verification). It    2479           validating module verification). It lacks any extra dependencies,
2480           and will not normally be loaded by     2480           and will not normally be loaded by the system unless explicitly
2481           requested by name.                     2481           requested by name.
2482                                                  2482 
2483           If unsure, say N.                      2483           If unsure, say N.
2484                                                  2484 
2485 config TEST_BITOPS                               2485 config TEST_BITOPS
2486         tristate "Test module for compilation    2486         tristate "Test module for compilation of bitops operations"
2487         help                                     2487         help
2488           This builds the "test_bitops" modul    2488           This builds the "test_bitops" module that is much like the
2489           TEST_LKM module except that it does    2489           TEST_LKM module except that it does a basic exercise of the
2490           set/clear_bit macros and get_count_    2490           set/clear_bit macros and get_count_order/long to make sure there are
2491           no compiler warnings from C=1 spars    2491           no compiler warnings from C=1 sparse checker or -Wextra
2492           compilations. It has no dependencie    2492           compilations. It has no dependencies and doesn't run or load unless
2493           explicitly requested by name.  for     2493           explicitly requested by name.  for example: modprobe test_bitops.
2494                                                  2494 
2495           If unsure, say N.                      2495           If unsure, say N.
2496                                                  2496 
2497 config TEST_VMALLOC                              2497 config TEST_VMALLOC
2498         tristate "Test module for stress/perf    2498         tristate "Test module for stress/performance analysis of vmalloc allocator"
2499         default n                                2499         default n
2500        depends on MMU                            2500        depends on MMU
2501         depends on m                             2501         depends on m
2502         help                                     2502         help
2503           This builds the "test_vmalloc" modu    2503           This builds the "test_vmalloc" module that should be used for
2504           stress and performance analysis. So    2504           stress and performance analysis. So, any new change for vmalloc
2505           subsystem can be evaluated from per    2505           subsystem can be evaluated from performance and stability point
2506           of view.                               2506           of view.
2507                                                  2507 
2508           If unsure, say N.                      2508           If unsure, say N.
2509                                                  2509 
2510 config TEST_BPF                                  2510 config TEST_BPF
2511         tristate "Test BPF filter functionali    2511         tristate "Test BPF filter functionality"
2512         depends on m && NET                      2512         depends on m && NET
2513         help                                     2513         help
2514           This builds the "test_bpf" module t    2514           This builds the "test_bpf" module that runs various test vectors
2515           against the BPF interpreter or BPF     2515           against the BPF interpreter or BPF JIT compiler depending on the
2516           current setting. This is in particu    2516           current setting. This is in particular useful for BPF JIT compiler
2517           development, but also to run regres    2517           development, but also to run regression tests against changes in
2518           the interpreter code. It also enabl    2518           the interpreter code. It also enables test stubs for eBPF maps and
2519           verifier used by user space verifie    2519           verifier used by user space verifier testsuite.
2520                                                  2520 
2521           If unsure, say N.                      2521           If unsure, say N.
2522                                                  2522 
2523 config TEST_BLACKHOLE_DEV                        2523 config TEST_BLACKHOLE_DEV
2524         tristate "Test blackhole netdev funct    2524         tristate "Test blackhole netdev functionality"
2525         depends on m && NET                      2525         depends on m && NET
2526         help                                     2526         help
2527           This builds the "test_blackhole_dev    2527           This builds the "test_blackhole_dev" module that validates the
2528           data path through this blackhole ne    2528           data path through this blackhole netdev.
2529                                                  2529 
2530           If unsure, say N.                      2530           If unsure, say N.
2531                                                  2531 
2532 config FIND_BIT_BENCHMARK                        2532 config FIND_BIT_BENCHMARK
2533         tristate "Test find_bit functions"       2533         tristate "Test find_bit functions"
2534         help                                     2534         help
2535           This builds the "test_find_bit" mod    2535           This builds the "test_find_bit" module that measure find_*_bit()
2536           functions performance.                 2536           functions performance.
2537                                                  2537 
2538           If unsure, say N.                      2538           If unsure, say N.
2539                                                  2539 
2540 config TEST_FIRMWARE                             2540 config TEST_FIRMWARE
2541         tristate "Test firmware loading via u    2541         tristate "Test firmware loading via userspace interface"
2542         depends on FW_LOADER                     2542         depends on FW_LOADER
2543         help                                     2543         help
2544           This builds the "test_firmware" mod    2544           This builds the "test_firmware" module that creates a userspace
2545           interface for testing firmware load    2545           interface for testing firmware loading. This can be used to
2546           control the triggering of firmware     2546           control the triggering of firmware loading without needing an
2547           actual firmware-using device. The c    2547           actual firmware-using device. The contents can be rechecked by
2548           userspace.                             2548           userspace.
2549                                                  2549 
2550           If unsure, say N.                      2550           If unsure, say N.
2551                                                  2551 
2552 config TEST_SYSCTL                               2552 config TEST_SYSCTL
2553         tristate "sysctl test driver"            2553         tristate "sysctl test driver"
2554         depends on PROC_SYSCTL                   2554         depends on PROC_SYSCTL
2555         help                                     2555         help
2556           This builds the "test_sysctl" modul    2556           This builds the "test_sysctl" module. This driver enables to test the
2557           proc sysctl interfaces available to    2557           proc sysctl interfaces available to drivers safely without affecting
2558           production knobs which might alter     2558           production knobs which might alter system functionality.
2559                                                  2559 
2560           If unsure, say N.                      2560           If unsure, say N.
2561                                                  2561 
2562 config BITFIELD_KUNIT                            2562 config BITFIELD_KUNIT
2563         tristate "KUnit test bitfield functio    2563         tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2564         depends on KUNIT                         2564         depends on KUNIT
2565         default KUNIT_ALL_TESTS                  2565         default KUNIT_ALL_TESTS
2566         help                                     2566         help
2567           Enable this option to test the bitf    2567           Enable this option to test the bitfield functions at boot.
2568                                                  2568 
2569           KUnit tests run during boot and out    2569           KUnit tests run during boot and output the results to the debug log
2570           in TAP format (http://testanything.    2570           in TAP format (http://testanything.org/). Only useful for kernel devs
2571           running the KUnit test harness, and    2571           running the KUnit test harness, and not intended for inclusion into a
2572           production build.                      2572           production build.
2573                                                  2573 
2574           For more information on KUnit and u    2574           For more information on KUnit and unit tests in general please refer
2575           to the KUnit documentation in Docum    2575           to the KUnit documentation in Documentation/dev-tools/kunit/.
2576                                                  2576 
2577           If unsure, say N.                      2577           If unsure, say N.
2578                                                  2578 
2579 config CHECKSUM_KUNIT                            2579 config CHECKSUM_KUNIT
2580         tristate "KUnit test checksum functio    2580         tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2581         depends on KUNIT                         2581         depends on KUNIT
2582         default KUNIT_ALL_TESTS                  2582         default KUNIT_ALL_TESTS
2583         help                                     2583         help
2584           Enable this option to test the chec    2584           Enable this option to test the checksum functions at boot.
2585                                                  2585 
2586           KUnit tests run during boot and out    2586           KUnit tests run during boot and output the results to the debug log
2587           in TAP format (http://testanything.    2587           in TAP format (http://testanything.org/). Only useful for kernel devs
2588           running the KUnit test harness, and    2588           running the KUnit test harness, and not intended for inclusion into a
2589           production build.                      2589           production build.
2590                                                  2590 
2591           For more information on KUnit and u    2591           For more information on KUnit and unit tests in general please refer
2592           to the KUnit documentation in Docum    2592           to the KUnit documentation in Documentation/dev-tools/kunit/.
2593                                                  2593 
2594           If unsure, say N.                      2594           If unsure, say N.
2595                                                  2595 
2596 config HASH_KUNIT_TEST                           2596 config HASH_KUNIT_TEST
2597         tristate "KUnit Test for integer hash    2597         tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2598         depends on KUNIT                         2598         depends on KUNIT
2599         default KUNIT_ALL_TESTS                  2599         default KUNIT_ALL_TESTS
2600         help                                     2600         help
2601           Enable this option to test the kern    2601           Enable this option to test the kernel's string (<linux/stringhash.h>), and
2602           integer (<linux/hash.h>) hash funct    2602           integer (<linux/hash.h>) hash functions on boot.
2603                                                  2603 
2604           KUnit tests run during boot and out    2604           KUnit tests run during boot and output the results to the debug log
2605           in TAP format (https://testanything    2605           in TAP format (https://testanything.org/). Only useful for kernel devs
2606           running the KUnit test harness, and    2606           running the KUnit test harness, and not intended for inclusion into a
2607           production build.                      2607           production build.
2608                                                  2608 
2609           For more information on KUnit and u    2609           For more information on KUnit and unit tests in general please refer
2610           to the KUnit documentation in Docum    2610           to the KUnit documentation in Documentation/dev-tools/kunit/.
2611                                                  2611 
2612           This is intended to help people wri    2612           This is intended to help people writing architecture-specific
2613           optimized versions. If unsure, say     2613           optimized versions. If unsure, say N.
2614                                                  2614 
2615 config RESOURCE_KUNIT_TEST                       2615 config RESOURCE_KUNIT_TEST
2616         tristate "KUnit test for resource API    2616         tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2617         depends on KUNIT                         2617         depends on KUNIT
2618         default KUNIT_ALL_TESTS                  2618         default KUNIT_ALL_TESTS
2619         help                                     2619         help
2620           This builds the resource API unit t    2620           This builds the resource API unit test.
2621           Tests the logic of API provided by     2621           Tests the logic of API provided by resource.c and ioport.h.
2622           For more information on KUnit and u    2622           For more information on KUnit and unit tests in general please refer
2623           to the KUnit documentation in Docum    2623           to the KUnit documentation in Documentation/dev-tools/kunit/.
2624                                                  2624 
2625           If unsure, say N.                      2625           If unsure, say N.
2626                                                  2626 
2627 config SYSCTL_KUNIT_TEST                         2627 config SYSCTL_KUNIT_TEST
2628         tristate "KUnit test for sysctl" if !    2628         tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629         depends on KUNIT                         2629         depends on KUNIT
2630         default KUNIT_ALL_TESTS                  2630         default KUNIT_ALL_TESTS
2631         help                                     2631         help
2632           This builds the proc sysctl unit te    2632           This builds the proc sysctl unit test, which runs on boot.
2633           Tests the API contract and implemen    2633           Tests the API contract and implementation correctness of sysctl.
2634           For more information on KUnit and u    2634           For more information on KUnit and unit tests in general please refer
2635           to the KUnit documentation in Docum    2635           to the KUnit documentation in Documentation/dev-tools/kunit/.
2636                                                  2636 
2637           If unsure, say N.                      2637           If unsure, say N.
2638                                                  2638 
2639 config LIST_KUNIT_TEST                           2639 config LIST_KUNIT_TEST
2640         tristate "KUnit Test for Kernel Linke    2640         tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641         depends on KUNIT                         2641         depends on KUNIT
2642         default KUNIT_ALL_TESTS                  2642         default KUNIT_ALL_TESTS
2643         help                                     2643         help
2644           This builds the linked list KUnit t    2644           This builds the linked list KUnit test suite.
2645           It tests that the API and basic fun    2645           It tests that the API and basic functionality of the list_head type
2646           and associated macros.                 2646           and associated macros.
2647                                                  2647 
2648           KUnit tests run during boot and out    2648           KUnit tests run during boot and output the results to the debug log
2649           in TAP format (https://testanything    2649           in TAP format (https://testanything.org/). Only useful for kernel devs
2650           running the KUnit test harness, and    2650           running the KUnit test harness, and not intended for inclusion into a
2651           production build.                      2651           production build.
2652                                                  2652 
2653           For more information on KUnit and u    2653           For more information on KUnit and unit tests in general please refer
2654           to the KUnit documentation in Docum    2654           to the KUnit documentation in Documentation/dev-tools/kunit/.
2655                                                  2655 
2656           If unsure, say N.                      2656           If unsure, say N.
2657                                                  2657 
2658 config HASHTABLE_KUNIT_TEST                      2658 config HASHTABLE_KUNIT_TEST
2659         tristate "KUnit Test for Kernel Hasht    2659         tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2660         depends on KUNIT                         2660         depends on KUNIT
2661         default KUNIT_ALL_TESTS                  2661         default KUNIT_ALL_TESTS
2662         help                                     2662         help
2663           This builds the hashtable KUnit tes    2663           This builds the hashtable KUnit test suite.
2664           It tests the basic functionality of    2664           It tests the basic functionality of the API defined in
2665           include/linux/hashtable.h. For more    2665           include/linux/hashtable.h. For more information on KUnit and
2666           unit tests in general please refer     2666           unit tests in general please refer to the KUnit documentation
2667           in Documentation/dev-tools/kunit/.     2667           in Documentation/dev-tools/kunit/.
2668                                                  2668 
2669           If unsure, say N.                      2669           If unsure, say N.
2670                                                  2670 
2671 config LINEAR_RANGES_TEST                        2671 config LINEAR_RANGES_TEST
2672         tristate "KUnit test for linear_range    2672         tristate "KUnit test for linear_ranges"
2673         depends on KUNIT                         2673         depends on KUNIT
2674         select LINEAR_RANGES                     2674         select LINEAR_RANGES
2675         help                                     2675         help
2676           This builds the linear_ranges unit     2676           This builds the linear_ranges unit test, which runs on boot.
2677           Tests the linear_ranges logic corre    2677           Tests the linear_ranges logic correctness.
2678           For more information on KUnit and u    2678           For more information on KUnit and unit tests in general please refer
2679           to the KUnit documentation in Docum    2679           to the KUnit documentation in Documentation/dev-tools/kunit/.
2680                                                  2680 
2681           If unsure, say N.                      2681           If unsure, say N.
2682                                                  2682 
2683 config CMDLINE_KUNIT_TEST                        2683 config CMDLINE_KUNIT_TEST
2684         tristate "KUnit test for cmdline API"    2684         tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2685         depends on KUNIT                         2685         depends on KUNIT
2686         default KUNIT_ALL_TESTS                  2686         default KUNIT_ALL_TESTS
2687         help                                     2687         help
2688           This builds the cmdline API unit te    2688           This builds the cmdline API unit test.
2689           Tests the logic of API provided by     2689           Tests the logic of API provided by cmdline.c.
2690           For more information on KUnit and u    2690           For more information on KUnit and unit tests in general please refer
2691           to the KUnit documentation in Docum    2691           to the KUnit documentation in Documentation/dev-tools/kunit/.
2692                                                  2692 
2693           If unsure, say N.                      2693           If unsure, say N.
2694                                                  2694 
2695 config BITS_TEST                                 2695 config BITS_TEST
2696         tristate "KUnit test for bits.h" if !    2696         tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2697         depends on KUNIT                         2697         depends on KUNIT
2698         default KUNIT_ALL_TESTS                  2698         default KUNIT_ALL_TESTS
2699         help                                     2699         help
2700           This builds the bits unit test.        2700           This builds the bits unit test.
2701           Tests the logic of macros defined i    2701           Tests the logic of macros defined in bits.h.
2702           For more information on KUnit and u    2702           For more information on KUnit and unit tests in general please refer
2703           to the KUnit documentation in Docum    2703           to the KUnit documentation in Documentation/dev-tools/kunit/.
2704                                                  2704 
2705           If unsure, say N.                      2705           If unsure, say N.
2706                                                  2706 
2707 config SLUB_KUNIT_TEST                           2707 config SLUB_KUNIT_TEST
2708         tristate "KUnit test for SLUB cache e    2708         tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2709         depends on SLUB_DEBUG && KUNIT           2709         depends on SLUB_DEBUG && KUNIT
2710         default KUNIT_ALL_TESTS                  2710         default KUNIT_ALL_TESTS
2711         help                                     2711         help
2712           This builds SLUB allocator unit tes    2712           This builds SLUB allocator unit test.
2713           Tests SLUB cache debugging function    2713           Tests SLUB cache debugging functionality.
2714           For more information on KUnit and u    2714           For more information on KUnit and unit tests in general please refer
2715           to the KUnit documentation in Docum    2715           to the KUnit documentation in Documentation/dev-tools/kunit/.
2716                                                  2716 
2717           If unsure, say N.                      2717           If unsure, say N.
2718                                                  2718 
2719 config RATIONAL_KUNIT_TEST                       2719 config RATIONAL_KUNIT_TEST
2720         tristate "KUnit test for rational.c"     2720         tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2721         depends on KUNIT && RATIONAL             2721         depends on KUNIT && RATIONAL
2722         default KUNIT_ALL_TESTS                  2722         default KUNIT_ALL_TESTS
2723         help                                     2723         help
2724           This builds the rational math unit     2724           This builds the rational math unit test.
2725           For more information on KUnit and u    2725           For more information on KUnit and unit tests in general please refer
2726           to the KUnit documentation in Docum    2726           to the KUnit documentation in Documentation/dev-tools/kunit/.
2727                                                  2727 
2728           If unsure, say N.                      2728           If unsure, say N.
2729                                                  2729 
2730 config MEMCPY_KUNIT_TEST                         2730 config MEMCPY_KUNIT_TEST
2731         tristate "Test memcpy(), memmove(), a    2731         tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2732         depends on KUNIT                         2732         depends on KUNIT
2733         default KUNIT_ALL_TESTS                  2733         default KUNIT_ALL_TESTS
2734         help                                     2734         help
2735           Builds unit tests for memcpy(), mem    2735           Builds unit tests for memcpy(), memmove(), and memset() functions.
2736           For more information on KUnit and u    2736           For more information on KUnit and unit tests in general please refer
2737           to the KUnit documentation in Docum    2737           to the KUnit documentation in Documentation/dev-tools/kunit/.
2738                                                  2738 
2739           If unsure, say N.                      2739           If unsure, say N.
2740                                                  2740 
2741 config IS_SIGNED_TYPE_KUNIT_TEST                 2741 config IS_SIGNED_TYPE_KUNIT_TEST
2742         tristate "Test is_signed_type() macro    2742         tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2743         depends on KUNIT                         2743         depends on KUNIT
2744         default KUNIT_ALL_TESTS                  2744         default KUNIT_ALL_TESTS
2745         help                                     2745         help
2746           Builds unit tests for the is_signed    2746           Builds unit tests for the is_signed_type() macro.
2747                                                  2747 
2748           For more information on KUnit and u    2748           For more information on KUnit and unit tests in general please refer
2749           to the KUnit documentation in Docum    2749           to the KUnit documentation in Documentation/dev-tools/kunit/.
2750                                                  2750 
2751           If unsure, say N.                      2751           If unsure, say N.
2752                                                  2752 
2753 config OVERFLOW_KUNIT_TEST                       2753 config OVERFLOW_KUNIT_TEST
2754         tristate "Test check_*_overflow() fun    2754         tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2755         depends on KUNIT                         2755         depends on KUNIT
2756         default KUNIT_ALL_TESTS                  2756         default KUNIT_ALL_TESTS
2757         help                                     2757         help
2758           Builds unit tests for the check_*_o    2758           Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2759           related functions.                     2759           related functions.
2760                                                  2760 
2761           For more information on KUnit and u    2761           For more information on KUnit and unit tests in general please refer
2762           to the KUnit documentation in Docum    2762           to the KUnit documentation in Documentation/dev-tools/kunit/.
2763                                                  2763 
2764           If unsure, say N.                      2764           If unsure, say N.
2765                                                  2765 
2766 config STACKINIT_KUNIT_TEST                      2766 config STACKINIT_KUNIT_TEST
2767         tristate "Test level of stack variabl    2767         tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2768         depends on KUNIT                         2768         depends on KUNIT
2769         default KUNIT_ALL_TESTS                  2769         default KUNIT_ALL_TESTS
2770         help                                     2770         help
2771           Test if the kernel is zero-initiali    2771           Test if the kernel is zero-initializing stack variables and
2772           padding. Coverage is controlled by     2772           padding. Coverage is controlled by compiler flags,
2773           CONFIG_INIT_STACK_ALL_PATTERN, CONF    2773           CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2774           CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFI    2774           CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2775           or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYR    2775           or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2776                                                  2776 
2777 config FORTIFY_KUNIT_TEST                        2777 config FORTIFY_KUNIT_TEST
2778         tristate "Test fortified str*() and m    2778         tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2779         depends on KUNIT                         2779         depends on KUNIT
2780         default KUNIT_ALL_TESTS                  2780         default KUNIT_ALL_TESTS
2781         help                                     2781         help
2782           Builds unit tests for checking inte    2782           Builds unit tests for checking internals of FORTIFY_SOURCE as used
2783           by the str*() and mem*() family of     2783           by the str*() and mem*() family of functions. For testing runtime
2784           traps of FORTIFY_SOURCE, see LKDTM'    2784           traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2785                                                  2785 
2786 config HW_BREAKPOINT_KUNIT_TEST                  2786 config HW_BREAKPOINT_KUNIT_TEST
2787         bool "Test hw_breakpoint constraints     2787         bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2788         depends on HAVE_HW_BREAKPOINT            2788         depends on HAVE_HW_BREAKPOINT
2789         depends on KUNIT=y                       2789         depends on KUNIT=y
2790         default KUNIT_ALL_TESTS                  2790         default KUNIT_ALL_TESTS
2791         help                                     2791         help
2792           Tests for hw_breakpoint constraints    2792           Tests for hw_breakpoint constraints accounting.
2793                                                  2793 
2794           If unsure, say N.                      2794           If unsure, say N.
2795                                                  2795 
2796 config SIPHASH_KUNIT_TEST                        2796 config SIPHASH_KUNIT_TEST
2797         tristate "Perform selftest on siphash    2797         tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2798         depends on KUNIT                         2798         depends on KUNIT
2799         default KUNIT_ALL_TESTS                  2799         default KUNIT_ALL_TESTS
2800         help                                     2800         help
2801           Enable this option to test the kern    2801           Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2802           functions on boot (or module load).    2802           functions on boot (or module load).
2803                                                  2803 
2804           This is intended to help people wri    2804           This is intended to help people writing architecture-specific
2805           optimized versions.  If unsure, say    2805           optimized versions.  If unsure, say N.
2806                                                  2806 
2807 config USERCOPY_KUNIT_TEST                       2807 config USERCOPY_KUNIT_TEST
2808         tristate "KUnit Test for user/kernel     2808         tristate "KUnit Test for user/kernel boundary protections"
2809         depends on KUNIT                         2809         depends on KUNIT
2810         default KUNIT_ALL_TESTS                  2810         default KUNIT_ALL_TESTS
2811         help                                     2811         help
2812           This builds the "usercopy_kunit" mo    2812           This builds the "usercopy_kunit" module that runs sanity checks
2813           on the copy_to/from_user infrastruc    2813           on the copy_to/from_user infrastructure, making sure basic
2814           user/kernel boundary testing is wor    2814           user/kernel boundary testing is working.
2815                                                  2815 
2816 config TEST_UDELAY                               2816 config TEST_UDELAY
2817         tristate "udelay test driver"            2817         tristate "udelay test driver"
2818         help                                     2818         help
2819           This builds the "udelay_test" modul    2819           This builds the "udelay_test" module that helps to make sure
2820           that udelay() is working properly.     2820           that udelay() is working properly.
2821                                                  2821 
2822           If unsure, say N.                      2822           If unsure, say N.
2823                                                  2823 
2824 config TEST_STATIC_KEYS                          2824 config TEST_STATIC_KEYS
2825         tristate "Test static keys"              2825         tristate "Test static keys"
2826         depends on m                             2826         depends on m
2827         help                                     2827         help
2828           Test the static key interfaces.        2828           Test the static key interfaces.
2829                                                  2829 
2830           If unsure, say N.                      2830           If unsure, say N.
2831                                                  2831 
2832 config TEST_DYNAMIC_DEBUG                        2832 config TEST_DYNAMIC_DEBUG
2833         tristate "Test DYNAMIC_DEBUG"            2833         tristate "Test DYNAMIC_DEBUG"
2834         depends on DYNAMIC_DEBUG                 2834         depends on DYNAMIC_DEBUG
2835         help                                     2835         help
2836           This module registers a tracer call    2836           This module registers a tracer callback to count enabled
2837           pr_debugs in a 'do_debugging' funct    2837           pr_debugs in a 'do_debugging' function, then alters their
2838           enablements, calls the function, an    2838           enablements, calls the function, and compares counts.
2839                                                  2839 
2840           If unsure, say N.                      2840           If unsure, say N.
2841                                                  2841 
2842 config TEST_KMOD                                 2842 config TEST_KMOD
2843         tristate "kmod stress tester"            2843         tristate "kmod stress tester"
2844         depends on m                             2844         depends on m
2845         depends on NETDEVICES && NET_CORE &&     2845         depends on NETDEVICES && NET_CORE && INET # for TUN
2846         depends on BLOCK                         2846         depends on BLOCK
2847         depends on PAGE_SIZE_LESS_THAN_256KB     2847         depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2848         select TEST_LKM                          2848         select TEST_LKM
2849         select XFS_FS                            2849         select XFS_FS
2850         select TUN                               2850         select TUN
2851         select BTRFS_FS                          2851         select BTRFS_FS
2852         help                                     2852         help
2853           Test the kernel's module loading me    2853           Test the kernel's module loading mechanism: kmod. kmod implements
2854           support to load modules using the L    2854           support to load modules using the Linux kernel's usermode helper.
2855           This test provides a series of test    2855           This test provides a series of tests against kmod.
2856                                                  2856 
2857           Although technically you can either    2857           Although technically you can either build test_kmod as a module or
2858           into the kernel we disallow buildin    2858           into the kernel we disallow building it into the kernel since
2859           it stress tests request_module() an    2859           it stress tests request_module() and this will very likely cause
2860           some issues by taking over precious    2860           some issues by taking over precious threads available from other
2861           module load requests, ultimately th    2861           module load requests, ultimately this could be fatal.
2862                                                  2862 
2863           To run tests run:                      2863           To run tests run:
2864                                                  2864 
2865           tools/testing/selftests/kmod/kmod.s    2865           tools/testing/selftests/kmod/kmod.sh --help
2866                                                  2866 
2867           If unsure, say N.                      2867           If unsure, say N.
2868                                                  2868 
2869 config TEST_DEBUG_VIRTUAL                        2869 config TEST_DEBUG_VIRTUAL
2870         tristate "Test CONFIG_DEBUG_VIRTUAL f    2870         tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871         depends on DEBUG_VIRTUAL                 2871         depends on DEBUG_VIRTUAL
2872         help                                     2872         help
2873           Test the kernel's ability to detect    2873           Test the kernel's ability to detect incorrect calls to
2874           virt_to_phys() done against the non    2874           virt_to_phys() done against the non-linear part of the
2875           kernel's virtual address map.          2875           kernel's virtual address map.
2876                                                  2876 
2877           If unsure, say N.                      2877           If unsure, say N.
2878                                                  2878 
2879 config TEST_MEMCAT_P                             2879 config TEST_MEMCAT_P
2880         tristate "Test memcat_p() helper func    2880         tristate "Test memcat_p() helper function"
2881         help                                     2881         help
2882           Test the memcat_p() helper for corr    2882           Test the memcat_p() helper for correctly merging two
2883           pointer arrays together.               2883           pointer arrays together.
2884                                                  2884 
2885           If unsure, say N.                      2885           If unsure, say N.
2886                                                  2886 
2887 config TEST_OBJAGG                               2887 config TEST_OBJAGG
2888         tristate "Perform selftest on object     2888         tristate "Perform selftest on object aggreration manager"
2889         default n                                2889         default n
2890         depends on OBJAGG                        2890         depends on OBJAGG
2891         help                                     2891         help
2892           Enable this option to test object a    2892           Enable this option to test object aggregation manager on boot
2893           (or module load).                      2893           (or module load).
2894                                                  2894 
2895 config TEST_MEMINIT                              2895 config TEST_MEMINIT
2896         tristate "Test heap/page initializati    2896         tristate "Test heap/page initialization"
2897         help                                     2897         help
2898           Test if the kernel is zero-initiali    2898           Test if the kernel is zero-initializing heap and page allocations.
2899           This can be useful to test init_on_    2899           This can be useful to test init_on_alloc and init_on_free features.
2900                                                  2900 
2901           If unsure, say N.                      2901           If unsure, say N.
2902                                                  2902 
2903 config TEST_HMM                                  2903 config TEST_HMM
2904         tristate "Test HMM (Heterogeneous Mem    2904         tristate "Test HMM (Heterogeneous Memory Management)"
2905         depends on TRANSPARENT_HUGEPAGE          2905         depends on TRANSPARENT_HUGEPAGE
2906         depends on DEVICE_PRIVATE                2906         depends on DEVICE_PRIVATE
2907         select HMM_MIRROR                        2907         select HMM_MIRROR
2908         select MMU_NOTIFIER                      2908         select MMU_NOTIFIER
2909         help                                     2909         help
2910           This is a pseudo device driver sole    2910           This is a pseudo device driver solely for testing HMM.
2911           Say M here if you want to build the    2911           Say M here if you want to build the HMM test module.
2912           Doing so will allow you to run tool    2912           Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913                                                  2913 
2914           If unsure, say N.                      2914           If unsure, say N.
2915                                                  2915 
2916 config TEST_FREE_PAGES                           2916 config TEST_FREE_PAGES
2917         tristate "Test freeing pages"            2917         tristate "Test freeing pages"
2918         help                                     2918         help
2919           Test that a memory leak does not oc    2919           Test that a memory leak does not occur due to a race between
2920           freeing a block of pages and a spec    2920           freeing a block of pages and a speculative page reference.
2921           Loading this module is safe if your    2921           Loading this module is safe if your kernel has the bug fixed.
2922           If the bug is not fixed, it will le    2922           If the bug is not fixed, it will leak gigabytes of memory and
2923           probably OOM your system.              2923           probably OOM your system.
2924                                                  2924 
2925 config TEST_FPU                                  2925 config TEST_FPU
2926         tristate "Test floating point operati    2926         tristate "Test floating point operations in kernel space"
2927         depends on ARCH_HAS_KERNEL_FPU_SUPPOR    2927         depends on ARCH_HAS_KERNEL_FPU_SUPPORT && !KCOV_INSTRUMENT_ALL
2928         help                                     2928         help
2929           Enable this option to add /sys/kern    2929           Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930           which will trigger a sequence of fl    2930           which will trigger a sequence of floating point operations. This is used
2931           for self-testing floating point con    2931           for self-testing floating point control register setting in
2932           kernel_fpu_begin().                    2932           kernel_fpu_begin().
2933                                                  2933 
2934           If unsure, say N.                      2934           If unsure, say N.
2935                                                  2935 
2936 config TEST_CLOCKSOURCE_WATCHDOG                 2936 config TEST_CLOCKSOURCE_WATCHDOG
2937         tristate "Test clocksource watchdog i    2937         tristate "Test clocksource watchdog in kernel space"
2938         depends on CLOCKSOURCE_WATCHDOG          2938         depends on CLOCKSOURCE_WATCHDOG
2939         help                                     2939         help
2940           Enable this option to create a kern    2940           Enable this option to create a kernel module that will trigger
2941           a test of the clocksource watchdog.    2941           a test of the clocksource watchdog.  This module may be loaded
2942           via modprobe or insmod in which cas    2942           via modprobe or insmod in which case it will run upon being
2943           loaded, or it may be built in, in w    2943           loaded, or it may be built in, in which case it will run
2944           shortly after boot.                    2944           shortly after boot.
2945                                                  2945 
2946           If unsure, say N.                      2946           If unsure, say N.
2947                                                  2947 
2948 config TEST_OBJPOOL                              2948 config TEST_OBJPOOL
2949         tristate "Test module for correctness    2949         tristate "Test module for correctness and stress of objpool"
2950         default n                                2950         default n
2951         depends on m && DEBUG_KERNEL             2951         depends on m && DEBUG_KERNEL
2952         help                                     2952         help
2953           This builds the "test_objpool" modu    2953           This builds the "test_objpool" module that should be used for
2954           correctness verification and concur    2954           correctness verification and concurrent testings of objects
2955           allocation and reclamation.            2955           allocation and reclamation.
2956                                                  2956 
2957           If unsure, say N.                      2957           If unsure, say N.
2958                                                  2958 
2959 endif # RUNTIME_TESTING_MENU                     2959 endif # RUNTIME_TESTING_MENU
2960                                                  2960 
2961 config ARCH_USE_MEMTEST                          2961 config ARCH_USE_MEMTEST
2962         bool                                     2962         bool
2963         help                                     2963         help
2964           An architecture should select this     2964           An architecture should select this when it uses early_memtest()
2965           during boot process.                   2965           during boot process.
2966                                                  2966 
2967 config MEMTEST                                   2967 config MEMTEST
2968         bool "Memtest"                           2968         bool "Memtest"
2969         depends on ARCH_USE_MEMTEST              2969         depends on ARCH_USE_MEMTEST
2970         help                                     2970         help
2971           This option adds a kernel parameter    2971           This option adds a kernel parameter 'memtest', which allows memtest
2972           to be set and executed.                2972           to be set and executed.
2973                 memtest=0, mean disabled; --     2973                 memtest=0, mean disabled; -- default
2974                 memtest=1, mean do 1 test pat    2974                 memtest=1, mean do 1 test pattern;
2975                 ...                              2975                 ...
2976                 memtest=17, mean do 17 test p    2976                 memtest=17, mean do 17 test patterns.
2977           If you are unsure how to answer thi    2977           If you are unsure how to answer this question, answer N.
2978                                                  2978 
2979                                                  2979 
2980                                                  2980 
2981 config HYPERV_TESTING                            2981 config HYPERV_TESTING
2982         bool "Microsoft Hyper-V driver testin    2982         bool "Microsoft Hyper-V driver testing"
2983         default n                                2983         default n
2984         depends on HYPERV && DEBUG_FS            2984         depends on HYPERV && DEBUG_FS
2985         help                                     2985         help
2986           Select this option to enable Hyper-    2986           Select this option to enable Hyper-V vmbus testing.
2987                                                  2987 
2988 endmenu # "Kernel Testing and Coverage"          2988 endmenu # "Kernel Testing and Coverage"
2989                                                  2989 
2990 menu "Rust hacking"                              2990 menu "Rust hacking"
2991                                                  2991 
2992 config RUST_DEBUG_ASSERTIONS                     2992 config RUST_DEBUG_ASSERTIONS
2993         bool "Debug assertions"                  2993         bool "Debug assertions"
2994         depends on RUST                          2994         depends on RUST
2995         help                                     2995         help
2996           Enables rustc's `-Cdebug-assertions    2996           Enables rustc's `-Cdebug-assertions` codegen option.
2997                                                  2997 
2998           This flag lets you turn `cfg(debug_    2998           This flag lets you turn `cfg(debug_assertions)` conditional
2999           compilation on or off. This can be     2999           compilation on or off. This can be used to enable extra debugging
3000           code in development but not in prod    3000           code in development but not in production. For example, it controls
3001           the behavior of the standard librar    3001           the behavior of the standard library's `debug_assert!` macro.
3002                                                  3002 
3003           Note that this will apply to all Ru    3003           Note that this will apply to all Rust code, including `core`.
3004                                                  3004 
3005           If unsure, say N.                      3005           If unsure, say N.
3006                                                  3006 
3007 config RUST_OVERFLOW_CHECKS                      3007 config RUST_OVERFLOW_CHECKS
3008         bool "Overflow checks"                   3008         bool "Overflow checks"
3009         default y                                3009         default y
3010         depends on RUST                          3010         depends on RUST
3011         help                                     3011         help
3012           Enables rustc's `-Coverflow-checks`    3012           Enables rustc's `-Coverflow-checks` codegen option.
3013                                                  3013 
3014           This flag allows you to control the    3014           This flag allows you to control the behavior of runtime integer
3015           overflow. When overflow-checks are     3015           overflow. When overflow-checks are enabled, a Rust panic will occur
3016           on overflow.                           3016           on overflow.
3017                                                  3017 
3018           Note that this will apply to all Ru    3018           Note that this will apply to all Rust code, including `core`.
3019                                                  3019 
3020           If unsure, say Y.                      3020           If unsure, say Y.
3021                                                  3021 
3022 config RUST_BUILD_ASSERT_ALLOW                   3022 config RUST_BUILD_ASSERT_ALLOW
3023         bool "Allow unoptimized build-time as    3023         bool "Allow unoptimized build-time assertions"
3024         depends on RUST                          3024         depends on RUST
3025         help                                     3025         help
3026           Controls how are `build_error!` and    3026           Controls how are `build_error!` and `build_assert!` handled during build.
3027                                                  3027 
3028           If calls to them exist in the binar    3028           If calls to them exist in the binary, it may indicate a violated invariant
3029           or that the optimizer failed to ver    3029           or that the optimizer failed to verify the invariant during compilation.
3030                                                  3030 
3031           This should not happen, thus by def    3031           This should not happen, thus by default the build is aborted. However,
3032           as an escape hatch, you can choose     3032           as an escape hatch, you can choose Y here to ignore them during build
3033           and let the check be carried at run    3033           and let the check be carried at runtime (with `panic!` being called if
3034           the check fails).                      3034           the check fails).
3035                                                  3035 
3036           If unsure, say N.                      3036           If unsure, say N.
3037                                                  3037 
3038 config RUST_KERNEL_DOCTESTS                      3038 config RUST_KERNEL_DOCTESTS
3039         bool "Doctests for the `kernel` crate    3039         bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3040         depends on RUST && KUNIT=y               3040         depends on RUST && KUNIT=y
3041         default KUNIT_ALL_TESTS                  3041         default KUNIT_ALL_TESTS
3042         help                                     3042         help
3043           This builds the documentation tests    3043           This builds the documentation tests of the `kernel` crate
3044           as KUnit tests.                        3044           as KUnit tests.
3045                                                  3045 
3046           For more information on KUnit and u    3046           For more information on KUnit and unit tests in general,
3047           please refer to the KUnit documenta    3047           please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3048                                                  3048 
3049           If unsure, say N.                      3049           If unsure, say N.
3050                                                  3050 
3051 endmenu # "Rust"                                 3051 endmenu # "Rust"
3052                                                  3052 
3053 endmenu # Kernel hacking                         3053 endmenu # Kernel hacking
                                                      

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