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TOMOYO Linux Cross Reference
Linux/lib/Kconfig.debug

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Diff markup

Differences between /lib/Kconfig.debug (Version linux-6.11.5) and /lib/Kconfig.debug (Version linux-5.13.19)


  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                     << 
 39         bool "Show build ID information in sta << 
 40         depends on PRINTK                      << 
 41         help                                   << 
 42           Selecting this option adds build ID  << 
 43           stacktraces printed with the printk  << 
 44                                                << 
 45           This option is intended for distros  << 
 46           accessible but can be downloaded giv << 
 47           kernel module where the function is  << 
 48                                                << 
 49 config CONSOLE_LOGLEVEL_DEFAULT                    38 config CONSOLE_LOGLEVEL_DEFAULT
 50         int "Default console loglevel (1-15)"      39         int "Default console loglevel (1-15)"
 51         range 1 15                                 40         range 1 15
 52         default "7"                                41         default "7"
 53         help                                       42         help
 54           Default loglevel to determine what w     43           Default loglevel to determine what will be printed on the console.
 55                                                    44 
 56           Setting a default here is equivalent     45           Setting a default here is equivalent to passing in loglevel=<x> in
 57           the kernel bootargs. loglevel=<x> co     46           the kernel bootargs. loglevel=<x> continues to override whatever
 58           value is specified here as well.         47           value is specified here as well.
 59                                                    48 
 60           Note: This does not affect the log l     49           Note: This does not affect the log level of un-prefixed printk()
 61           usage in the kernel. That is control     50           usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
 62           option.                                  51           option.
 63                                                    52 
 64 config CONSOLE_LOGLEVEL_QUIET                      53 config CONSOLE_LOGLEVEL_QUIET
 65         int "quiet console loglevel (1-15)"        54         int "quiet console loglevel (1-15)"
 66         range 1 15                                 55         range 1 15
 67         default "4"                                56         default "4"
 68         help                                       57         help
 69           loglevel to use when "quiet" is pass     58           loglevel to use when "quiet" is passed on the kernel commandline.
 70                                                    59 
 71           When "quiet" is passed on the kernel     60           When "quiet" is passed on the kernel commandline this loglevel
 72           will be used as the loglevel. IOW pa     61           will be used as the loglevel. IOW passing "quiet" will be the
 73           equivalent of passing "loglevel=<CON     62           equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
 74                                                    63 
 75 config MESSAGE_LOGLEVEL_DEFAULT                    64 config MESSAGE_LOGLEVEL_DEFAULT
 76         int "Default message log level (1-7)"      65         int "Default message log level (1-7)"
 77         range 1 7                                  66         range 1 7
 78         default "4"                                67         default "4"
 79         help                                       68         help
 80           Default log level for printk stateme     69           Default log level for printk statements with no specified priority.
 81                                                    70 
 82           This was hard-coded to KERN_WARNING      71           This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
 83           that are auditing their logs closely     72           that are auditing their logs closely may want to set it to a lower
 84           priority.                                73           priority.
 85                                                    74 
 86           Note: This does not affect what mess     75           Note: This does not affect what message level gets printed on the console
 87           by default. To change that, use logl     76           by default. To change that, use loglevel=<x> in the kernel bootargs,
 88           or pick a different CONSOLE_LOGLEVEL     77           or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
 89                                                    78 
 90 config BOOT_PRINTK_DELAY                           79 config BOOT_PRINTK_DELAY
 91         bool "Delay each boot printk message b     80         bool "Delay each boot printk message by N milliseconds"
 92         depends on DEBUG_KERNEL && PRINTK && G     81         depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 93         help                                       82         help
 94           This build option allows you to read     83           This build option allows you to read kernel boot messages
 95           by inserting a short delay after eac     84           by inserting a short delay after each one.  The delay is
 96           specified in milliseconds on the ker     85           specified in milliseconds on the kernel command line,
 97           using "boot_delay=N".                    86           using "boot_delay=N".
 98                                                    87 
 99           It is likely that you would also nee     88           It is likely that you would also need to use "lpj=M" to preset
100           the "loops per jiffie" value.            89           the "loops per jiffie" value.
101           See a previous boot log for the "lpj     90           See a previous boot log for the "lpj" value to use for your
102           system, and then set "lpj=M" before      91           system, and then set "lpj=M" before setting "boot_delay=N".
103           NOTE:  Using this option may adverse     92           NOTE:  Using this option may adversely affect SMP systems.
104           I.e., processors other than the firs     93           I.e., processors other than the first one may not boot up.
105           BOOT_PRINTK_DELAY also may cause LOC     94           BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106           what it believes to be lockup condit     95           what it believes to be lockup conditions.
107                                                    96 
108 config DYNAMIC_DEBUG                               97 config DYNAMIC_DEBUG
109         bool "Enable dynamic printk() support"     98         bool "Enable dynamic printk() support"
110         default n                                  99         default n
111         depends on PRINTK                         100         depends on PRINTK
112         depends on (DEBUG_FS || PROC_FS)          101         depends on (DEBUG_FS || PROC_FS)
113         select DYNAMIC_DEBUG_CORE                 102         select DYNAMIC_DEBUG_CORE
114         help                                      103         help
115                                                   104 
116           Compiles debug level messages into t    105           Compiles debug level messages into the kernel, which would not
117           otherwise be available at runtime. T    106           otherwise be available at runtime. These messages can then be
118           enabled/disabled based on various le    107           enabled/disabled based on various levels of scope - per source file,
119           function, module, format string, and    108           function, module, format string, and line number. This mechanism
120           implicitly compiles in all pr_debug(    109           implicitly compiles in all pr_debug() and dev_dbg() calls, which
121           enlarges the kernel text size by abo    110           enlarges the kernel text size by about 2%.
122                                                   111 
123           If a source file is compiled with DE    112           If a source file is compiled with DEBUG flag set, any
124           pr_debug() calls in it are enabled b    113           pr_debug() calls in it are enabled by default, but can be
125           disabled at runtime as below.  Note     114           disabled at runtime as below.  Note that DEBUG flag is
126           turned on by many CONFIG_*DEBUG* opt    115           turned on by many CONFIG_*DEBUG* options.
127                                                   116 
128           Usage:                                  117           Usage:
129                                                   118 
130           Dynamic debugging is controlled via     119           Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131           which is contained in the 'debugfs'     120           which is contained in the 'debugfs' filesystem or procfs.
132           Thus, the debugfs or procfs filesyst    121           Thus, the debugfs or procfs filesystem must first be mounted before
133           making use of this feature.             122           making use of this feature.
134           We refer the control file as: <debug    123           We refer the control file as: <debugfs>/dynamic_debug/control. This
135           file contains a list of the debug st    124           file contains a list of the debug statements that can be enabled. The
136           format for each line of the file is:    125           format for each line of the file is:
137                                                   126 
138                 filename:lineno [module]functi    127                 filename:lineno [module]function flags format
139                                                   128 
140           filename : source file of the debug     129           filename : source file of the debug statement
141           lineno : line number of the debug st    130           lineno : line number of the debug statement
142           module : module that contains the de    131           module : module that contains the debug statement
143           function : function that contains th    132           function : function that contains the debug statement
144           flags : '=p' means the line is turne    133           flags : '=p' means the line is turned 'on' for printing
145           format : the format used for the deb    134           format : the format used for the debug statement
146                                                   135 
147           From a live system:                     136           From a live system:
148                                                   137 
149                 nullarbor:~ # cat <debugfs>/dy    138                 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150                 # filename:lineno [module]func    139                 # filename:lineno [module]function flags format
151                 fs/aio.c:222 [aio]__put_ioctx     140                 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152                 fs/aio.c:248 [aio]ioctx_alloc     141                 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153                 fs/aio.c:1770 [aio]sys_io_canc    142                 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154                                                   143 
155           Example usage:                          144           Example usage:
156                                                   145 
157                 // enable the message at line     146                 // enable the message at line 1603 of file svcsock.c
158                 nullarbor:~ # echo -n 'file sv    147                 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159                                                   148                                                 <debugfs>/dynamic_debug/control
160                                                   149 
161                 // enable all the messages in     150                 // enable all the messages in file svcsock.c
162                 nullarbor:~ # echo -n 'file sv    151                 nullarbor:~ # echo -n 'file svcsock.c +p' >
163                                                   152                                                 <debugfs>/dynamic_debug/control
164                                                   153 
165                 // enable all the messages in     154                 // enable all the messages in the NFS server module
166                 nullarbor:~ # echo -n 'module     155                 nullarbor:~ # echo -n 'module nfsd +p' >
167                                                   156                                                 <debugfs>/dynamic_debug/control
168                                                   157 
169                 // enable all 12 messages in t    158                 // enable all 12 messages in the function svc_process()
170                 nullarbor:~ # echo -n 'func sv    159                 nullarbor:~ # echo -n 'func svc_process +p' >
171                                                   160                                                 <debugfs>/dynamic_debug/control
172                                                   161 
173                 // disable all 12 messages in     162                 // disable all 12 messages in the function svc_process()
174                 nullarbor:~ # echo -n 'func sv    163                 nullarbor:~ # echo -n 'func svc_process -p' >
175                                                   164                                                 <debugfs>/dynamic_debug/control
176                                                   165 
177           See Documentation/admin-guide/dynami    166           See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178           information.                            167           information.
179                                                   168 
180 config DYNAMIC_DEBUG_CORE                         169 config DYNAMIC_DEBUG_CORE
181         bool "Enable core function of dynamic     170         bool "Enable core function of dynamic debug support"
182         depends on PRINTK                         171         depends on PRINTK
183         depends on (DEBUG_FS || PROC_FS)          172         depends on (DEBUG_FS || PROC_FS)
184         help                                      173         help
185           Enable core functional support of dy    174           Enable core functional support of dynamic debug. It is useful
186           when you want to tie dynamic debug t    175           when you want to tie dynamic debug to your kernel modules with
187           DYNAMIC_DEBUG_MODULE defined for eac    176           DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188           the case of embedded system where th    177           the case of embedded system where the kernel image size is
189           sensitive for people.                   178           sensitive for people.
190                                                   179 
191 config SYMBOLIC_ERRNAME                           180 config SYMBOLIC_ERRNAME
192         bool "Support symbolic error names in     181         bool "Support symbolic error names in printf"
193         default y if PRINTK                       182         default y if PRINTK
194         help                                      183         help
195           If you say Y here, the kernel's prin    184           If you say Y here, the kernel's printf implementation will
196           be able to print symbolic error name    185           be able to print symbolic error names such as ENOSPC instead
197           of the number 28. It makes the kerne    186           of the number 28. It makes the kernel image slightly larger
198           (about 3KB), but can make the kernel    187           (about 3KB), but can make the kernel logs easier to read.
199                                                   188 
200 config DEBUG_BUGVERBOSE                           189 config DEBUG_BUGVERBOSE
201         bool "Verbose BUG() reporting (adds 70    190         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202         depends on BUG && (GENERIC_BUG || HAVE    191         depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203         default y                                 192         default y
204         help                                      193         help
205           Say Y here to make BUG() panics outp    194           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    195           of the BUG call as well as the EIP and oops trace.  This aids
207           debugging but costs about 70-100K of    196           debugging but costs about 70-100K of memory.
208                                                   197 
209 endmenu # "printk and dmesg options"              198 endmenu # "printk and dmesg options"
210                                                   199 
211 config DEBUG_KERNEL                            << 
212         bool "Kernel debugging"                << 
213         help                                   << 
214           Say Y here if you are developing dri << 
215           identify kernel problems.            << 
216                                                << 
217 config DEBUG_MISC                              << 
218         bool "Miscellaneous debug code"        << 
219         default DEBUG_KERNEL                   << 
220         depends on DEBUG_KERNEL                << 
221         help                                   << 
222           Say Y here if you need to enable mis << 
223           be under a more specific debug optio << 
224                                                << 
225 menu "Compile-time checks and compiler options    200 menu "Compile-time checks and compiler options"
226                                                   201 
227 config DEBUG_INFO                                 202 config DEBUG_INFO
228         bool                                   !! 203         bool "Compile the kernel with debug info"
229         help                                   !! 204         depends on DEBUG_KERNEL && !COMPILE_TEST
230           A kernel debug info option other tha << 
231           in the "Debug information" choice be << 
232           information will be generated for bu << 
233                                                << 
234 # Clang generates .uleb128 with label differen << 
235 # older binutils ports do not support when uti << 
236 # relaxation: https://sourceware.org/bugzilla/ << 
237 config AS_HAS_NON_CONST_ULEB128                << 
238         def_bool $(as-instr,.uleb128 .Lexpr_en << 
239                                                << 
240 choice                                         << 
241         prompt "Debug information"             << 
242         depends on DEBUG_KERNEL                << 
243         help                                      205         help
244           Selecting something other than "None !! 206           If you say Y here the resulting kernel image will include
245           that will include debugging info res !! 207           debugging info resulting in a larger kernel image.
246           This adds debug symbols to the kerne    208           This adds debug symbols to the kernel and modules (gcc -g), and
247           is needed if you intend to use kerne    209           is needed if you intend to use kernel crashdump or binary object
248           tools like crash, kgdb, LKCD, gdb, e    210           tools like crash, kgdb, LKCD, gdb, etc on the kernel.
                                                   >> 211           Say Y here only if you plan to debug the kernel.
249                                                   212 
250           Choose which version of DWARF debug  !! 213           If unsure, say N.
251           select "Toolchain default".          << 
252                                                << 
253 config DEBUG_INFO_NONE                         << 
254         bool "Disable debug information"       << 
255         help                                   << 
256           Do not build the kernel with debuggi << 
257           result in a faster and smaller build << 
258                                                << 
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT      << 
260         bool "Rely on the toolchain's implicit << 
261         select DEBUG_INFO                      << 
262         depends on !CC_IS_CLANG || AS_IS_LLVM  << 
263         help                                   << 
264           The implicit default version of DWAR << 
265           toolchain changes over time.         << 
266                                                << 
267           This can break consumers of the debu << 
268           support newer revisions, and prevent << 
269           those should be less common scenario << 
270                                                << 
271 config DEBUG_INFO_DWARF4                       << 
272         bool "Generate DWARF Version 4 debugin << 
273         select DEBUG_INFO                      << 
274         depends on !CC_IS_CLANG || AS_IS_LLVM  << 
275         help                                   << 
276           Generate DWARF v4 debug info. This r << 
277           if using clang without clang's integ << 
278                                                << 
279           If you have consumers of DWARF debug << 
280           newer revisions of DWARF, you may wi << 
281           config select this.                  << 
282                                                << 
283 config DEBUG_INFO_DWARF5                       << 
284         bool "Generate DWARF Version 5 debugin << 
285         select DEBUG_INFO                      << 
286         depends on !ARCH_HAS_BROKEN_DWARF5     << 
287         depends on !CC_IS_CLANG || AS_IS_LLVM  << 
288         help                                   << 
289           Generate DWARF v5 debug info. Requir << 
290           5.0+ accepts the -gdwarf-5 flag but  << 
291           draft features until 7.0), and gdb 8 << 
292                                                << 
293           Changes to the structure of debug in << 
294           15-18% savings in resulting image an << 
295           compared to DWARF Version 4. DWARF V << 
296           extensions such as accelerators for  << 
297           for fission (.dwo/.dwp) files. Users << 
298           config if they rely on tooling that  << 
299           support DWARF Version 5.             << 
300                                                << 
301 endchoice # "Debug information"                << 
302                                                   214 
303 if DEBUG_INFO                                     215 if DEBUG_INFO
304                                                   216 
305 config DEBUG_INFO_REDUCED                         217 config DEBUG_INFO_REDUCED
306         bool "Reduce debugging information"       218         bool "Reduce debugging information"
307         help                                      219         help
308           If you say Y here gcc is instructed     220           If you say Y here gcc is instructed to generate less debugging
309           information for structure types. Thi    221           information for structure types. This means that tools that
310           need full debugging information (lik    222           need full debugging information (like kgdb or systemtap) won't
311           be happy. But if you merely need deb    223           be happy. But if you merely need debugging information to
312           resolve line numbers there is no los    224           resolve line numbers there is no loss. Advantage is that
313           build directory object sizes shrink     225           build directory object sizes shrink dramatically over a full
314           DEBUG_INFO build and compile times a    226           DEBUG_INFO build and compile times are reduced too.
315           Only works with newer gcc versions.     227           Only works with newer gcc versions.
316                                                   228 
317 choice                                         !! 229 config DEBUG_INFO_COMPRESSED
318         prompt "Compressed Debug information"  !! 230         bool "Compressed debugging information"
319         help                                   << 
320           Compress the resulting debug info. R << 
321           but requires that consumers are able << 
322                                                << 
323           If unsure, choose DEBUG_INFO_COMPRES << 
324                                                << 
325 config DEBUG_INFO_COMPRESSED_NONE              << 
326         bool "Don't compress debug information << 
327         help                                   << 
328           Don't compress debug info sections.  << 
329                                                << 
330 config DEBUG_INFO_COMPRESSED_ZLIB              << 
331         bool "Compress debugging information w << 
332         depends on $(cc-option,-gz=zlib)          231         depends on $(cc-option,-gz=zlib)
333         depends on $(ld-option,--compress-debu    232         depends on $(ld-option,--compress-debug-sections=zlib)
334         help                                      233         help
335           Compress the debug information using    234           Compress the debug information using zlib.  Requires GCC 5.0+ or Clang
336           5.0+, binutils 2.26+, and zlib.         235           5.0+, binutils 2.26+, and zlib.
337                                                   236 
338           Users of dpkg-deb via scripts/packag    237           Users of dpkg-deb via scripts/package/builddeb may find an increase in
339           size of their debug .deb packages wi    238           size of their debug .deb packages with this config set, due to the
340           debug info being compressed with zli    239           debug info being compressed with zlib, then the object files being
341           recompressed with a different compre    240           recompressed with a different compression scheme. But this is still
342           preferable to setting $KDEB_COMPRESS    241           preferable to setting $KDEB_COMPRESS to "none" which would be even
343           larger.                                 242           larger.
344                                                   243 
345 config DEBUG_INFO_COMPRESSED_ZSTD              << 
346         bool "Compress debugging information w << 
347         depends on $(cc-option,-gz=zstd)       << 
348         depends on $(ld-option,--compress-debu << 
349         help                                   << 
350           Compress the debug information using << 
351           compression than zlib, for about the << 
352           toolchain support.  Requires GCC 13. << 
353           zstd.                                << 
354                                                << 
355 endchoice # "Compressed Debug information"     << 
356                                                << 
357 config DEBUG_INFO_SPLIT                           244 config DEBUG_INFO_SPLIT
358         bool "Produce split debuginfo in .dwo     245         bool "Produce split debuginfo in .dwo files"
359         depends on $(cc-option,-gsplit-dwarf)     246         depends on $(cc-option,-gsplit-dwarf)
360         # RISC-V linker relaxation + -gsplit-d << 
361         # prior to 12.x:                       << 
362         # https://github.com/llvm/llvm-project << 
363         # https://gcc.gnu.org/bugzilla/show_bu << 
364         depends on !RISCV || GCC_VERSION >= 12 << 
365         help                                      247         help
366           Generate debug info into separate .d    248           Generate debug info into separate .dwo files. This significantly
367           reduces the build directory size for    249           reduces the build directory size for builds with DEBUG_INFO,
368           because it stores the information on    250           because it stores the information only once on disk in .dwo
369           files instead of multiple times in o    251           files instead of multiple times in object files and executables.
370           In addition the debug information is    252           In addition the debug information is also compressed.
371                                                   253 
372           Requires recent gcc (4.7+) and recen    254           Requires recent gcc (4.7+) and recent gdb/binutils.
373           Any tool that packages or reads debu    255           Any tool that packages or reads debug information would need
374           to know about the .dwo files and inc    256           to know about the .dwo files and include them.
375           Incompatible with older versions of     257           Incompatible with older versions of ccache.
376                                                   258 
                                                   >> 259 choice
                                                   >> 260         prompt "DWARF version"
                                                   >> 261         help
                                                   >> 262           Which version of DWARF debug info to emit.
                                                   >> 263 
                                                   >> 264 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
                                                   >> 265         bool "Rely on the toolchain's implicit default DWARF version"
                                                   >> 266         help
                                                   >> 267           The implicit default version of DWARF debug info produced by a
                                                   >> 268           toolchain changes over time.
                                                   >> 269 
                                                   >> 270           This can break consumers of the debug info that haven't upgraded to
                                                   >> 271           support newer revisions, and prevent testing newer versions, but
                                                   >> 272           those should be less common scenarios.
                                                   >> 273 
                                                   >> 274           If unsure, say Y.
                                                   >> 275 
                                                   >> 276 config DEBUG_INFO_DWARF4
                                                   >> 277         bool "Generate DWARF Version 4 debuginfo"
                                                   >> 278         help
                                                   >> 279           Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
                                                   >> 280 
                                                   >> 281           If you have consumers of DWARF debug info that are not ready for
                                                   >> 282           newer revisions of DWARF, you may wish to choose this or have your
                                                   >> 283           config select this.
                                                   >> 284 
                                                   >> 285 config DEBUG_INFO_DWARF5
                                                   >> 286         bool "Generate DWARF Version 5 debuginfo"
                                                   >> 287         depends on GCC_VERSION >= 50000 || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
                                                   >> 288         depends on !DEBUG_INFO_BTF
                                                   >> 289         help
                                                   >> 290           Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
                                                   >> 291           5.0+ accepts the -gdwarf-5 flag but only had partial support for some
                                                   >> 292           draft features until 7.0), and gdb 8.0+.
                                                   >> 293 
                                                   >> 294           Changes to the structure of debug info in Version 5 allow for around
                                                   >> 295           15-18% savings in resulting image and debug info section sizes as
                                                   >> 296           compared to DWARF Version 4. DWARF Version 5 standardizes previous
                                                   >> 297           extensions such as accelerators for symbol indexing and the format
                                                   >> 298           for fission (.dwo/.dwp) files. Users may not want to select this
                                                   >> 299           config if they rely on tooling that has not yet been updated to
                                                   >> 300           support DWARF Version 5.
                                                   >> 301 
                                                   >> 302 endchoice # "DWARF version"
                                                   >> 303 
377 config DEBUG_INFO_BTF                             304 config DEBUG_INFO_BTF
378         bool "Generate BTF type information"   !! 305         bool "Generate BTF typeinfo"
379         depends on !DEBUG_INFO_SPLIT && !DEBUG    306         depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380         depends on !GCC_PLUGIN_RANDSTRUCT || C    307         depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
381         depends on BPF_SYSCALL                 << 
382         depends on !DEBUG_INFO_DWARF5 || PAHOL << 
383         # pahole uses elfutils, which does not << 
384         depends on !HEXAGON                    << 
385         help                                      308         help
386           Generate deduplicated BTF type infor    309           Generate deduplicated BTF type information from DWARF debug info.
387           Turning this on expects presence of     310           Turning this on expects presence of pahole tool, which will convert
388           DWARF type info into equivalent dedu    311           DWARF type info into equivalent deduplicated BTF type info.
389                                                   312 
390 config PAHOLE_HAS_SPLIT_BTF                       313 config PAHOLE_HAS_SPLIT_BTF
391         def_bool PAHOLE_VERSION >= 119         !! 314         def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119")
392                                                << 
393 config PAHOLE_HAS_BTF_TAG                      << 
394         def_bool PAHOLE_VERSION >= 123         << 
395         depends on CC_IS_CLANG                 << 
396         help                                   << 
397           Decide whether pahole emits btf_tag  << 
398           btf_decl_tag) or not. Currently only << 
399           these attributes, so make the config << 
400                                                << 
401 config PAHOLE_HAS_LANG_EXCLUDE                 << 
402         def_bool PAHOLE_VERSION >= 124         << 
403         help                                   << 
404           Support for the --lang_exclude flag  << 
405           compilation units from the supplied  << 
406           omit Rust CUs which are not supporte << 
407           otherwise it would emit malformed ke << 
408           using DEBUG_INFO_BTF_MODULES.        << 
409                                                   315 
410 config DEBUG_INFO_BTF_MODULES                     316 config DEBUG_INFO_BTF_MODULES
411         bool "Generate BTF type information fo !! 317         def_bool y
412         default y                              << 
413         depends on DEBUG_INFO_BTF && MODULES &    318         depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
414         help                                      319         help
415           Generate compact split BTF type info    320           Generate compact split BTF type information for kernel modules.
416                                                   321 
417 config MODULE_ALLOW_BTF_MISMATCH               << 
418         bool "Allow loading modules with non-m << 
419         depends on DEBUG_INFO_BTF_MODULES      << 
420         help                                   << 
421           For modules whose split BTF does not << 
422           BTF rather than refusing to load. Th << 
423           module BTF enabled is to reject modu << 
424           this option will still load module B << 
425           it when a mismatch is found.         << 
426                                                << 
427 config GDB_SCRIPTS                                322 config GDB_SCRIPTS
428         bool "Provide GDB scripts for kernel d    323         bool "Provide GDB scripts for kernel debugging"
429         help                                      324         help
430           This creates the required links to G    325           This creates the required links to GDB helper scripts in the
431           build directory. If you load vmlinux    326           build directory. If you load vmlinux into gdb, the helper
432           scripts will be automatically import    327           scripts will be automatically imported by gdb as well, and
433           additional functions are available t    328           additional functions are available to analyze a Linux kernel
434           instance. See Documentation/dev-tool    329           instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435           for further details.                    330           for further details.
436                                                   331 
437 endif # DEBUG_INFO                                332 endif # DEBUG_INFO
438                                                   333 
439 config FRAME_WARN                                 334 config FRAME_WARN
440         int "Warn for stack frames larger than    335         int "Warn for stack frames larger than"
441         range 0 8192                              336         range 0 8192
442         default 0 if KMSAN                     << 
443         default 2048 if GCC_PLUGIN_LATENT_ENTR    337         default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444         default 2048 if PARISC                 !! 338         default 1280 if (!64BIT && PARISC)
445         default 1536 if (!64BIT && XTENSA)     !! 339         default 1024 if (!64BIT && !PARISC)
446         default 1280 if KASAN && !64BIT        << 
447         default 1024 if !64BIT                 << 
448         default 2048 if 64BIT                     340         default 2048 if 64BIT
449         help                                      341         help
450           Tell the compiler to warn at build t !! 342           Tell gcc to warn at build time for stack frames larger than this.
451           Setting this too low will cause a lo    343           Setting this too low will cause a lot of warnings.
452           Setting it to 0 disables the warning    344           Setting it to 0 disables the warning.
453                                                   345 
454 config STRIP_ASM_SYMS                             346 config STRIP_ASM_SYMS
455         bool "Strip assembler-generated symbol    347         bool "Strip assembler-generated symbols during link"
456         default n                                 348         default n
457         help                                      349         help
458           Strip internal assembler-generated s    350           Strip internal assembler-generated symbols during a link (symbols
459           that look like '.Lxxx') so they don'    351           that look like '.Lxxx') so they don't pollute the output of
460           get_wchan() and suchlike.               352           get_wchan() and suchlike.
461                                                   353 
462 config READABLE_ASM                               354 config READABLE_ASM
463         bool "Generate readable assembler code    355         bool "Generate readable assembler code"
464         depends on DEBUG_KERNEL                   356         depends on DEBUG_KERNEL
465         depends on CC_IS_GCC                   << 
466         help                                      357         help
467           Disable some compiler optimizations     358           Disable some compiler optimizations that tend to generate human unreadable
468           assembler output. This may make the     359           assembler output. This may make the kernel slightly slower, but it helps
469           to keep kernel developers who have t    360           to keep kernel developers who have to stare a lot at assembler listings
470           sane.                                   361           sane.
471                                                   362 
472 config HEADERS_INSTALL                            363 config HEADERS_INSTALL
473         bool "Install uapi headers to usr/incl    364         bool "Install uapi headers to usr/include"
474         depends on !UML                           365         depends on !UML
475         help                                      366         help
476           This option will install uapi header    367           This option will install uapi headers (headers exported to user-space)
477           into the usr/include directory for u    368           into the usr/include directory for use during the kernel build.
478           This is unneeded for building the ke    369           This is unneeded for building the kernel itself, but needed for some
479           user-space program samples. It is al    370           user-space program samples. It is also needed by some features such
480           as uapi header sanity checks.           371           as uapi header sanity checks.
481                                                   372 
482 config DEBUG_SECTION_MISMATCH                     373 config DEBUG_SECTION_MISMATCH
483         bool "Enable full Section mismatch ana    374         bool "Enable full Section mismatch analysis"
484         depends on CC_IS_GCC                   << 
485         help                                      375         help
486           The section mismatch analysis checks    376           The section mismatch analysis checks if there are illegal
487           references from one section to anoth    377           references from one section to another section.
488           During linktime or runtime, some sec    378           During linktime or runtime, some sections are dropped;
489           any use of code/data previously in t    379           any use of code/data previously in these sections would
490           most likely result in an oops.          380           most likely result in an oops.
491           In the code, functions and variables    381           In the code, functions and variables are annotated with
492           __init,, etc. (see the full list in     382           __init,, etc. (see the full list in include/linux/init.h),
493           which results in the code/data being    383           which results in the code/data being placed in specific sections.
494           The section mismatch analysis is alw    384           The section mismatch analysis is always performed after a full
495           kernel build, and enabling this opti    385           kernel build, and enabling this option causes the following
496           additional step to occur:               386           additional step to occur:
497           - Add the option -fno-inline-functio    387           - Add the option -fno-inline-functions-called-once to gcc commands.
498             When inlining a function annotated    388             When inlining a function annotated with __init in a non-init
499             function, we would lose the sectio    389             function, we would lose the section information and thus
500             the analysis would not catch the i    390             the analysis would not catch the illegal reference.
501             This option tells gcc to inline le    391             This option tells gcc to inline less (but it does result in
502             a larger kernel).                     392             a larger kernel).
503                                                   393 
504 config SECTION_MISMATCH_WARN_ONLY                 394 config SECTION_MISMATCH_WARN_ONLY
505         bool "Make section mismatch errors non    395         bool "Make section mismatch errors non-fatal"
506         default y                                 396         default y
507         help                                      397         help
508           If you say N here, the build process    398           If you say N here, the build process will fail if there are any
509           section mismatch, instead of just th    399           section mismatch, instead of just throwing warnings.
510                                                   400 
511           If unsure, say Y.                       401           If unsure, say Y.
512                                                   402 
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B          !! 403 config DEBUG_FORCE_FUNCTION_ALIGN_32B
514         bool "Force all function address 64B a !! 404         bool "Force all function address 32B aligned" if EXPERT
515         depends on EXPERT && (X86_64 || ARM64  << 
516         select FUNCTION_ALIGNMENT_64B          << 
517         help                                      405         help
518           There are cases that a commit from o    406           There are cases that a commit from one domain changes the function
519           address alignment of other domains,     407           address alignment of other domains, and cause magic performance
520           bump (regression or improvement). En    408           bump (regression or improvement). Enable this option will help to
521           verify if the bump is caused by func    409           verify if the bump is caused by function alignment changes, while
522           it will slightly increase the kernel    410           it will slightly increase the kernel size and affect icache usage.
523                                                   411 
524           It is mainly for debug and performan    412           It is mainly for debug and performance tuning use.
525                                                   413 
526 #                                                 414 #
527 # Select this config option from the architect    415 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers     416 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE    417 # option on the architecture (regardless of KERNEL_DEBUG):
530 #                                                 418 #
531 config ARCH_WANT_FRAME_POINTERS                   419 config ARCH_WANT_FRAME_POINTERS
532         bool                                      420         bool
533                                                   421 
534 config FRAME_POINTER                              422 config FRAME_POINTER
535         bool "Compile the kernel with frame po    423         bool "Compile the kernel with frame pointers"
536         depends on DEBUG_KERNEL && (M68K || UM    424         depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537         default y if (DEBUG_INFO && UML) || AR    425         default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538         help                                      426         help
539           If you say Y here the resulting kern    427           If you say Y here the resulting kernel image will be slightly
540           larger and slower, but it gives very    428           larger and slower, but it gives very useful debugging information
541           in case of kernel bugs. (precise oop    429           in case of kernel bugs. (precise oopses/stacktraces/warnings)
542                                                   430 
543 config OBJTOOL                                 << 
544         bool                                   << 
545                                                << 
546 config STACK_VALIDATION                           431 config STACK_VALIDATION
547         bool "Compile-time stack metadata vali    432         bool "Compile-time stack metadata validation"
548         depends on HAVE_STACK_VALIDATION && UN !! 433         depends on HAVE_STACK_VALIDATION
549         select OBJTOOL                         << 
550         default n                                 434         default n
551         help                                      435         help
552           Validate frame pointer rules at comp !! 436           Add compile-time checks to validate stack metadata, including frame
553           runtime stack traces are more reliab !! 437           pointers (if CONFIG_FRAME_POINTER is enabled).  This helps ensure
                                                   >> 438           that runtime stack traces are more reliable.
                                                   >> 439 
                                                   >> 440           This is also a prerequisite for generation of ORC unwind data, which
                                                   >> 441           is needed for CONFIG_UNWINDER_ORC.
554                                                   442 
555           For more information, see               443           For more information, see
556           tools/objtool/Documentation/objtool. !! 444           tools/objtool/Documentation/stack-validation.txt.
557                                                   445 
558 config NOINSTR_VALIDATION                      !! 446 config VMLINUX_VALIDATION
559         bool                                      447         bool
560         depends on HAVE_NOINSTR_VALIDATION &&  !! 448         depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
561         select OBJTOOL                         << 
562         default y                                 449         default y
563                                                   450 
564 config VMLINUX_MAP                                451 config VMLINUX_MAP
565         bool "Generate vmlinux.map file when l    452         bool "Generate vmlinux.map file when linking"
566         depends on EXPERT                         453         depends on EXPERT
567         help                                      454         help
568           Selecting this option will pass "-Ma    455           Selecting this option will pass "-Map=vmlinux.map" to ld
569           when linking vmlinux. That file can     456           when linking vmlinux. That file can be useful for verifying
570           and debugging magic section games, a    457           and debugging magic section games, and for seeing which
571           pieces of code get eliminated with      458           pieces of code get eliminated with
572           CONFIG_LD_DEAD_CODE_DATA_ELIMINATION    459           CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
573                                                   460 
574 config DEBUG_FORCE_WEAK_PER_CPU                   461 config DEBUG_FORCE_WEAK_PER_CPU
575         bool "Force weak per-cpu definitions"     462         bool "Force weak per-cpu definitions"
576         depends on DEBUG_KERNEL                   463         depends on DEBUG_KERNEL
577         help                                      464         help
578           s390 and alpha require percpu variab    465           s390 and alpha require percpu variables in modules to be
579           defined weak to work around addressi    466           defined weak to work around addressing range issue which
580           puts the following two restrictions     467           puts the following two restrictions on percpu variable
581           definitions.                            468           definitions.
582                                                   469 
583           1. percpu symbols must be unique whe    470           1. percpu symbols must be unique whether static or not
584           2. percpu variables can't be defined    471           2. percpu variables can't be defined inside a function
585                                                   472 
586           To ensure that generic code follows     473           To ensure that generic code follows the above rules, this
587           option forces all percpu variables t    474           option forces all percpu variables to be defined as weak.
588                                                   475 
589 endmenu # "Compiler options"                      476 endmenu # "Compiler options"
590                                                   477 
591 menu "Generic Kernel Debugging Instruments"       478 menu "Generic Kernel Debugging Instruments"
592                                                   479 
593 config MAGIC_SYSRQ                                480 config MAGIC_SYSRQ
594         bool "Magic SysRq key"                    481         bool "Magic SysRq key"
595         depends on !UML                           482         depends on !UML
596         help                                      483         help
597           If you say Y here, you will have som    484           If you say Y here, you will have some control over the system even
598           if the system crashes for example du    485           if the system crashes for example during kernel debugging (e.g., you
599           will be able to flush the buffer cac    486           will be able to flush the buffer cache to disk, reboot the system
600           immediately or dump some status info    487           immediately or dump some status information). This is accomplished
601           by pressing various keys while holdi    488           by pressing various keys while holding SysRq (Alt+PrintScreen). It
602           also works on a serial console (on P    489           also works on a serial console (on PC hardware at least), if you
603           send a BREAK and then within 5 secon    490           send a BREAK and then within 5 seconds a command keypress. The
604           keys are documented in <file:Documen    491           keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605           Don't say Y unless you really know w    492           Don't say Y unless you really know what this hack does.
606                                                   493 
607 config MAGIC_SYSRQ_DEFAULT_ENABLE                 494 config MAGIC_SYSRQ_DEFAULT_ENABLE
608         hex "Enable magic SysRq key functions     495         hex "Enable magic SysRq key functions by default"
609         depends on MAGIC_SYSRQ                    496         depends on MAGIC_SYSRQ
610         default 0x1                               497         default 0x1
611         help                                      498         help
612           Specifies which SysRq key functions     499           Specifies which SysRq key functions are enabled by default.
613           This may be set to 1 or 0 to enable     500           This may be set to 1 or 0 to enable or disable them all, or
614           to a bitmask as described in Documen    501           to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615                                                   502 
616 config MAGIC_SYSRQ_SERIAL                         503 config MAGIC_SYSRQ_SERIAL
617         bool "Enable magic SysRq key over seri    504         bool "Enable magic SysRq key over serial"
618         depends on MAGIC_SYSRQ                    505         depends on MAGIC_SYSRQ
619         default y                                 506         default y
620         help                                      507         help
621           Many embedded boards have a disconne    508           Many embedded boards have a disconnected TTL level serial which can
622           generate some garbage that can lead     509           generate some garbage that can lead to spurious false sysrq detects.
623           This option allows you to decide whe    510           This option allows you to decide whether you want to enable the
624           magic SysRq key.                        511           magic SysRq key.
625                                                   512 
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE                513 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627         string "Char sequence that enables mag    514         string "Char sequence that enables magic SysRq over serial"
628         depends on MAGIC_SYSRQ_SERIAL             515         depends on MAGIC_SYSRQ_SERIAL
629         default ""                                516         default ""
630         help                                      517         help
631           Specifies a sequence of characters t    518           Specifies a sequence of characters that can follow BREAK to enable
632           SysRq on a serial console.              519           SysRq on a serial console.
633                                                   520 
634           If unsure, leave an empty string and    521           If unsure, leave an empty string and the option will not be enabled.
635                                                   522 
636 config DEBUG_FS                                   523 config DEBUG_FS
637         bool "Debug Filesystem"                   524         bool "Debug Filesystem"
638         help                                      525         help
639           debugfs is a virtual file system tha    526           debugfs is a virtual file system that kernel developers use to put
640           debugging files into.  Enable this o    527           debugging files into.  Enable this option to be able to read and
641           write to these files.                   528           write to these files.
642                                                   529 
643           For detailed documentation on the de    530           For detailed documentation on the debugfs API, see
644           Documentation/filesystems/.             531           Documentation/filesystems/.
645                                                   532 
646           If unsure, say N.                       533           If unsure, say N.
647                                                   534 
648 choice                                            535 choice
649         prompt "Debugfs default access"           536         prompt "Debugfs default access"
650         depends on DEBUG_FS                       537         depends on DEBUG_FS
651         default DEBUG_FS_ALLOW_ALL                538         default DEBUG_FS_ALLOW_ALL
652         help                                      539         help
653           This selects the default access rest    540           This selects the default access restrictions for debugfs.
654           It can be overridden with kernel com    541           It can be overridden with kernel command line option
655           debugfs=[on,no-mount,off]. The restr    542           debugfs=[on,no-mount,off]. The restrictions apply for API access
656           and filesystem registration.            543           and filesystem registration.
657                                                   544 
658 config DEBUG_FS_ALLOW_ALL                         545 config DEBUG_FS_ALLOW_ALL
659         bool "Access normal"                      546         bool "Access normal"
660         help                                      547         help
661           No restrictions apply. Both API and     548           No restrictions apply. Both API and filesystem registration
662           is on. This is the normal default op    549           is on. This is the normal default operation.
663                                                   550 
664 config DEBUG_FS_DISALLOW_MOUNT                    551 config DEBUG_FS_DISALLOW_MOUNT
665         bool "Do not register debugfs as files    552         bool "Do not register debugfs as filesystem"
666         help                                      553         help
667           The API is open but filesystem is no    554           The API is open but filesystem is not loaded. Clients can still do
668           their work and read with debug tools    555           their work and read with debug tools that do not need
669           debugfs filesystem.                     556           debugfs filesystem.
670                                                   557 
671 config DEBUG_FS_ALLOW_NONE                        558 config DEBUG_FS_ALLOW_NONE
672         bool "No access"                          559         bool "No access"
673         help                                      560         help
674           Access is off. Clients get -PERM whe    561           Access is off. Clients get -PERM when trying to create nodes in
675           debugfs tree and debugfs is not regi    562           debugfs tree and debugfs is not registered as a filesystem.
676           Client can then back-off or continue    563           Client can then back-off or continue without debugfs access.
677                                                   564 
678 endchoice                                         565 endchoice
679                                                   566 
680 source "lib/Kconfig.kgdb"                         567 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan"                        568 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan"                        569 source "lib/Kconfig.kcsan"
683                                                   570 
684 endmenu                                           571 endmenu
685                                                   572 
686 menu "Networking Debugging"                    !! 573 config DEBUG_KERNEL
                                                   >> 574         bool "Kernel debugging"
                                                   >> 575         help
                                                   >> 576           Say Y here if you are developing drivers or trying to debug and
                                                   >> 577           identify kernel problems.
687                                                   578 
688 source "net/Kconfig.debug"                     !! 579 config DEBUG_MISC
                                                   >> 580         bool "Miscellaneous debug code"
                                                   >> 581         default DEBUG_KERNEL
                                                   >> 582         depends on DEBUG_KERNEL
                                                   >> 583         help
                                                   >> 584           Say Y here if you need to enable miscellaneous debug code that should
                                                   >> 585           be under a more specific debug option but isn't.
689                                                   586 
690 endmenu # "Networking Debugging"               << 
691                                                   587 
692 menu "Memory Debugging"                           588 menu "Memory Debugging"
693                                                   589 
694 source "mm/Kconfig.debug"                         590 source "mm/Kconfig.debug"
695                                                   591 
696 config DEBUG_OBJECTS                              592 config DEBUG_OBJECTS
697         bool "Debug object operations"            593         bool "Debug object operations"
698         depends on DEBUG_KERNEL                   594         depends on DEBUG_KERNEL
699         help                                      595         help
700           If you say Y here, additional code w    596           If you say Y here, additional code will be inserted into the
701           kernel to track the life time of var    597           kernel to track the life time of various objects and validate
702           the operations on those objects.        598           the operations on those objects.
703                                                   599 
704 config DEBUG_OBJECTS_SELFTEST                     600 config DEBUG_OBJECTS_SELFTEST
705         bool "Debug objects selftest"             601         bool "Debug objects selftest"
706         depends on DEBUG_OBJECTS                  602         depends on DEBUG_OBJECTS
707         help                                      603         help
708           This enables the selftest of the obj    604           This enables the selftest of the object debug code.
709                                                   605 
710 config DEBUG_OBJECTS_FREE                         606 config DEBUG_OBJECTS_FREE
711         bool "Debug objects in freed memory"      607         bool "Debug objects in freed memory"
712         depends on DEBUG_OBJECTS                  608         depends on DEBUG_OBJECTS
713         help                                      609         help
714           This enables checks whether a k/v fr    610           This enables checks whether a k/v free operation frees an area
715           which contains an object which has n    611           which contains an object which has not been deactivated
716           properly. This can make kmalloc/kfre    612           properly. This can make kmalloc/kfree-intensive workloads
717           much slower.                            613           much slower.
718                                                   614 
719 config DEBUG_OBJECTS_TIMERS                       615 config DEBUG_OBJECTS_TIMERS
720         bool "Debug timer objects"                616         bool "Debug timer objects"
721         depends on DEBUG_OBJECTS                  617         depends on DEBUG_OBJECTS
722         help                                      618         help
723           If you say Y here, additional code w    619           If you say Y here, additional code will be inserted into the
724           timer routines to track the life tim    620           timer routines to track the life time of timer objects and
725           validate the timer operations.          621           validate the timer operations.
726                                                   622 
727 config DEBUG_OBJECTS_WORK                         623 config DEBUG_OBJECTS_WORK
728         bool "Debug work objects"                 624         bool "Debug work objects"
729         depends on DEBUG_OBJECTS                  625         depends on DEBUG_OBJECTS
730         help                                      626         help
731           If you say Y here, additional code w    627           If you say Y here, additional code will be inserted into the
732           work queue routines to track the lif    628           work queue routines to track the life time of work objects and
733           validate the work operations.           629           validate the work operations.
734                                                   630 
735 config DEBUG_OBJECTS_RCU_HEAD                     631 config DEBUG_OBJECTS_RCU_HEAD
736         bool "Debug RCU callbacks objects"        632         bool "Debug RCU callbacks objects"
737         depends on DEBUG_OBJECTS                  633         depends on DEBUG_OBJECTS
738         help                                      634         help
739           Enable this to turn on debugging of     635           Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740                                                   636 
741 config DEBUG_OBJECTS_PERCPU_COUNTER               637 config DEBUG_OBJECTS_PERCPU_COUNTER
742         bool "Debug percpu counter objects"       638         bool "Debug percpu counter objects"
743         depends on DEBUG_OBJECTS                  639         depends on DEBUG_OBJECTS
744         help                                      640         help
745           If you say Y here, additional code w    641           If you say Y here, additional code will be inserted into the
746           percpu counter routines to track the    642           percpu counter routines to track the life time of percpu counter
747           objects and validate the percpu coun    643           objects and validate the percpu counter operations.
748                                                   644 
749 config DEBUG_OBJECTS_ENABLE_DEFAULT               645 config DEBUG_OBJECTS_ENABLE_DEFAULT
750         int "debug_objects bootup default valu    646         int "debug_objects bootup default value (0-1)"
751         range 0 1                                 647         range 0 1
752         default "1"                               648         default "1"
753         depends on DEBUG_OBJECTS                  649         depends on DEBUG_OBJECTS
754         help                                      650         help
755           Debug objects boot parameter default    651           Debug objects boot parameter default value
756                                                   652 
757 config SHRINKER_DEBUG                          !! 653 config DEBUG_SLAB
758         bool "Enable shrinker debugging suppor !! 654         bool "Debug slab memory allocations"
759         depends on DEBUG_FS                    !! 655         depends on DEBUG_KERNEL && SLAB
                                                   >> 656         help
                                                   >> 657           Say Y here to have the kernel do limited verification on memory
                                                   >> 658           allocation as well as poisoning memory on free to catch use of freed
                                                   >> 659           memory. This can make kmalloc/kfree-intensive workloads much slower.
                                                   >> 660 
                                                   >> 661 config SLUB_DEBUG_ON
                                                   >> 662         bool "SLUB debugging on by default"
                                                   >> 663         depends on SLUB && SLUB_DEBUG
                                                   >> 664         default n
                                                   >> 665         help
                                                   >> 666           Boot with debugging on by default. SLUB boots by default with
                                                   >> 667           the runtime debug capabilities switched off. Enabling this is
                                                   >> 668           equivalent to specifying the "slub_debug" parameter on boot.
                                                   >> 669           There is no support for more fine grained debug control like
                                                   >> 670           possible with slub_debug=xxx. SLUB debugging may be switched
                                                   >> 671           off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
                                                   >> 672           "slub_debug=-".
                                                   >> 673 
                                                   >> 674 config SLUB_STATS
                                                   >> 675         default n
                                                   >> 676         bool "Enable SLUB performance statistics"
                                                   >> 677         depends on SLUB && SYSFS
                                                   >> 678         help
                                                   >> 679           SLUB statistics are useful to debug SLUBs allocation behavior in
                                                   >> 680           order find ways to optimize the allocator. This should never be
                                                   >> 681           enabled for production use since keeping statistics slows down
                                                   >> 682           the allocator by a few percentage points. The slabinfo command
                                                   >> 683           supports the determination of the most active slabs to figure
                                                   >> 684           out which slabs are relevant to a particular load.
                                                   >> 685           Try running: slabinfo -DA
                                                   >> 686 
                                                   >> 687 config HAVE_DEBUG_KMEMLEAK
                                                   >> 688         bool
                                                   >> 689 
                                                   >> 690 config DEBUG_KMEMLEAK
                                                   >> 691         bool "Kernel memory leak detector"
                                                   >> 692         depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
                                                   >> 693         select DEBUG_FS
                                                   >> 694         select STACKTRACE if STACKTRACE_SUPPORT
                                                   >> 695         select KALLSYMS
                                                   >> 696         select CRC32
                                                   >> 697         help
                                                   >> 698           Say Y here if you want to enable the memory leak
                                                   >> 699           detector. The memory allocation/freeing is traced in a way
                                                   >> 700           similar to the Boehm's conservative garbage collector, the
                                                   >> 701           difference being that the orphan objects are not freed but
                                                   >> 702           only shown in /sys/kernel/debug/kmemleak. Enabling this
                                                   >> 703           feature will introduce an overhead to memory
                                                   >> 704           allocations. See Documentation/dev-tools/kmemleak.rst for more
                                                   >> 705           details.
                                                   >> 706 
                                                   >> 707           Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
                                                   >> 708           of finding leaks due to the slab objects poisoning.
                                                   >> 709 
                                                   >> 710           In order to access the kmemleak file, debugfs needs to be
                                                   >> 711           mounted (usually at /sys/kernel/debug).
                                                   >> 712 
                                                   >> 713 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
                                                   >> 714         int "Kmemleak memory pool size"
                                                   >> 715         depends on DEBUG_KMEMLEAK
                                                   >> 716         range 200 1000000
                                                   >> 717         default 16000
                                                   >> 718         help
                                                   >> 719           Kmemleak must track all the memory allocations to avoid
                                                   >> 720           reporting false positives. Since memory may be allocated or
                                                   >> 721           freed before kmemleak is fully initialised, use a static pool
                                                   >> 722           of metadata objects to track such callbacks. After kmemleak is
                                                   >> 723           fully initialised, this memory pool acts as an emergency one
                                                   >> 724           if slab allocations fail.
                                                   >> 725 
                                                   >> 726 config DEBUG_KMEMLEAK_TEST
                                                   >> 727         tristate "Simple test for the kernel memory leak detector"
                                                   >> 728         depends on DEBUG_KMEMLEAK && m
                                                   >> 729         help
                                                   >> 730           This option enables a module that explicitly leaks memory.
                                                   >> 731 
                                                   >> 732           If unsure, say N.
                                                   >> 733 
                                                   >> 734 config DEBUG_KMEMLEAK_DEFAULT_OFF
                                                   >> 735         bool "Default kmemleak to off"
                                                   >> 736         depends on DEBUG_KMEMLEAK
                                                   >> 737         help
                                                   >> 738           Say Y here to disable kmemleak by default. It can then be enabled
                                                   >> 739           on the command line via kmemleak=on.
                                                   >> 740 
                                                   >> 741 config DEBUG_KMEMLEAK_AUTO_SCAN
                                                   >> 742         bool "Enable kmemleak auto scan thread on boot up"
                                                   >> 743         default y
                                                   >> 744         depends on DEBUG_KMEMLEAK
760         help                                      745         help
761           Say Y to enable the shrinker debugfs !! 746           Depending on the cpu, kmemleak scan may be cpu intensive and can
762           visibility into the kernel memory sh !! 747           stall user tasks at times. This option enables/disables automatic
763           Disable it to avoid an extra memory  !! 748           kmemleak scan at boot up.
                                                   >> 749 
                                                   >> 750           Say N here to disable kmemleak auto scan thread to stop automatic
                                                   >> 751           scanning. Disabling this option disables automatic reporting of
                                                   >> 752           memory leaks.
                                                   >> 753 
                                                   >> 754           If unsure, say Y.
764                                                   755 
765 config DEBUG_STACK_USAGE                          756 config DEBUG_STACK_USAGE
766         bool "Stack utilization instrumentatio    757         bool "Stack utilization instrumentation"
767         depends on DEBUG_KERNEL                !! 758         depends on DEBUG_KERNEL && !IA64
768         help                                      759         help
769           Enables the display of the minimum a    760           Enables the display of the minimum amount of free stack which each
770           task has ever had available in the s    761           task has ever had available in the sysrq-T and sysrq-P debug output.
771           Also emits a message to dmesg when a << 
772           used more stack space than previousl << 
773                                                   762 
774           This option will slow down process c    763           This option will slow down process creation somewhat.
775                                                   764 
776 config SCHED_STACK_END_CHECK                      765 config SCHED_STACK_END_CHECK
777         bool "Detect stack corruption on calls    766         bool "Detect stack corruption on calls to schedule()"
778         depends on DEBUG_KERNEL                   767         depends on DEBUG_KERNEL
779         default n                                 768         default n
780         help                                      769         help
781           This option checks for a stack overr    770           This option checks for a stack overrun on calls to schedule().
782           If the stack end location is found t    771           If the stack end location is found to be over written always panic as
783           the content of the corrupted region     772           the content of the corrupted region can no longer be trusted.
784           This is to ensure no erroneous behav    773           This is to ensure no erroneous behaviour occurs which could result in
785           data corruption or a sporadic crash     774           data corruption or a sporadic crash at a later stage once the region
786           is examined. The runtime overhead in    775           is examined. The runtime overhead introduced is minimal.
787                                                   776 
788 config ARCH_HAS_DEBUG_VM_PGTABLE                  777 config ARCH_HAS_DEBUG_VM_PGTABLE
789         bool                                      778         bool
790         help                                      779         help
791           An architecture should select this w    780           An architecture should select this when it can successfully
792           build and run DEBUG_VM_PGTABLE.         781           build and run DEBUG_VM_PGTABLE.
793                                                   782 
794 config DEBUG_VM_IRQSOFF                        << 
795         def_bool DEBUG_VM && !PREEMPT_RT       << 
796                                                << 
797 config DEBUG_VM                                   783 config DEBUG_VM
798         bool "Debug VM"                           784         bool "Debug VM"
799         depends on DEBUG_KERNEL                   785         depends on DEBUG_KERNEL
800         help                                      786         help
801           Enable this to turn on extended chec    787           Enable this to turn on extended checks in the virtual-memory system
802           that may impact performance.            788           that may impact performance.
803                                                   789 
804           If unsure, say N.                       790           If unsure, say N.
805                                                   791 
806 config DEBUG_VM_SHOOT_LAZIES                   !! 792 config DEBUG_VM_VMACACHE
807         bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 793         bool "Debug VMA caching"
808         depends on DEBUG_VM                    << 
809         depends on MMU_LAZY_TLB_SHOOTDOWN      << 
810         help                                   << 
811           Enable additional IPIs that ensure l << 
812           before the mm is freed.              << 
813                                                << 
814           If unsure, say N.                    << 
815                                                << 
816 config DEBUG_VM_MAPLE_TREE                     << 
817         bool "Debug VM maple trees"            << 
818         depends on DEBUG_VM                       794         depends on DEBUG_VM
819         select DEBUG_MAPLE_TREE                << 
820         help                                      795         help
821           Enable VM maple tree debugging infor !! 796           Enable this to turn on VMA caching debug information. Doing so
                                                   >> 797           can cause significant overhead, so only enable it in non-production
                                                   >> 798           environments.
822                                                   799 
823           If unsure, say N.                       800           If unsure, say N.
824                                                   801 
825 config DEBUG_VM_RB                                802 config DEBUG_VM_RB
826         bool "Debug VM red-black trees"           803         bool "Debug VM red-black trees"
827         depends on DEBUG_VM                       804         depends on DEBUG_VM
828         help                                      805         help
829           Enable VM red-black tree debugging i    806           Enable VM red-black tree debugging information and extra validations.
830                                                   807 
831           If unsure, say N.                       808           If unsure, say N.
832                                                   809 
833 config DEBUG_VM_PGFLAGS                           810 config DEBUG_VM_PGFLAGS
834         bool "Debug page-flags operations"        811         bool "Debug page-flags operations"
835         depends on DEBUG_VM                       812         depends on DEBUG_VM
836         help                                      813         help
837           Enables extra validation on page fla    814           Enables extra validation on page flags operations.
838                                                   815 
839           If unsure, say N.                       816           If unsure, say N.
840                                                   817 
841 config DEBUG_VM_PGTABLE                           818 config DEBUG_VM_PGTABLE
842         bool "Debug arch page table for semant    819         bool "Debug arch page table for semantics compliance"
843         depends on MMU                            820         depends on MMU
844         depends on ARCH_HAS_DEBUG_VM_PGTABLE      821         depends on ARCH_HAS_DEBUG_VM_PGTABLE
845         default y if DEBUG_VM                     822         default y if DEBUG_VM
846         help                                      823         help
847           This option provides a debug method     824           This option provides a debug method which can be used to test
848           architecture page table helper funct    825           architecture page table helper functions on various platforms in
849           verifying if they comply with expect    826           verifying if they comply with expected generic MM semantics. This
850           will help architecture code in makin    827           will help architecture code in making sure that any changes or
851           new additions of these helpers still    828           new additions of these helpers still conform to expected
852           semantics of the generic MM. Platfor    829           semantics of the generic MM. Platforms will have to opt in for
853           this through ARCH_HAS_DEBUG_VM_PGTAB    830           this through ARCH_HAS_DEBUG_VM_PGTABLE.
854                                                   831 
855           If unsure, say N.                       832           If unsure, say N.
856                                                   833 
857 config ARCH_HAS_DEBUG_VIRTUAL                     834 config ARCH_HAS_DEBUG_VIRTUAL
858         bool                                      835         bool
859                                                   836 
860 config DEBUG_VIRTUAL                              837 config DEBUG_VIRTUAL
861         bool "Debug VM translations"              838         bool "Debug VM translations"
862         depends on DEBUG_KERNEL && ARCH_HAS_DE    839         depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863         help                                      840         help
864           Enable some costly sanity checks in     841           Enable some costly sanity checks in virtual to page code. This can
865           catch mistakes with virt_to_page() a    842           catch mistakes with virt_to_page() and friends.
866                                                   843 
867           If unsure, say N.                       844           If unsure, say N.
868                                                   845 
869 config DEBUG_NOMMU_REGIONS                        846 config DEBUG_NOMMU_REGIONS
870         bool "Debug the global anon/private NO    847         bool "Debug the global anon/private NOMMU mapping region tree"
871         depends on DEBUG_KERNEL && !MMU           848         depends on DEBUG_KERNEL && !MMU
872         help                                      849         help
873           This option causes the global tree o    850           This option causes the global tree of anonymous and private mapping
874           regions to be regularly checked for     851           regions to be regularly checked for invalid topology.
875                                                   852 
876 config DEBUG_MEMORY_INIT                          853 config DEBUG_MEMORY_INIT
877         bool "Debug memory initialisation" if     854         bool "Debug memory initialisation" if EXPERT
878         default !EXPERT                           855         default !EXPERT
879         help                                      856         help
880           Enable this for additional checks du    857           Enable this for additional checks during memory initialisation.
881           The sanity checks verify aspects of     858           The sanity checks verify aspects of the VM such as the memory model
882           and other information provided by th    859           and other information provided by the architecture. Verbose
883           information will be printed at KERN_    860           information will be printed at KERN_DEBUG loglevel depending
884           on the mminit_loglevel= command-line    861           on the mminit_loglevel= command-line option.
885                                                   862 
886           If unsure, say Y                        863           If unsure, say Y
887                                                   864 
888 config MEMORY_NOTIFIER_ERROR_INJECT               865 config MEMORY_NOTIFIER_ERROR_INJECT
889         tristate "Memory hotplug notifier erro    866         tristate "Memory hotplug notifier error injection module"
890         depends on MEMORY_HOTPLUG && NOTIFIER_ !! 867         depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891         help                                      868         help
892           This option provides the ability to     869           This option provides the ability to inject artificial errors to
893           memory hotplug notifier chain callba    870           memory hotplug notifier chain callbacks.  It is controlled through
894           debugfs interface under /sys/kernel/    871           debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895                                                   872 
896           If the notifier call chain should be    873           If the notifier call chain should be failed with some events
897           notified, write the error code to "a    874           notified, write the error code to "actions/<notifier event>/error".
898                                                   875 
899           Example: Inject memory hotplug offli    876           Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900                                                   877 
901           # cd /sys/kernel/debug/notifier-erro    878           # cd /sys/kernel/debug/notifier-error-inject/memory
902           # echo -12 > actions/MEM_GOING_OFFLI    879           # echo -12 > actions/MEM_GOING_OFFLINE/error
903           # echo offline > /sys/devices/system    880           # echo offline > /sys/devices/system/memory/memoryXXX/state
904           bash: echo: write error: Cannot allo    881           bash: echo: write error: Cannot allocate memory
905                                                   882 
906           To compile this code as a module, ch    883           To compile this code as a module, choose M here: the module will
907           be called memory-notifier-error-inje    884           be called memory-notifier-error-inject.
908                                                   885 
909           If unsure, say N.                       886           If unsure, say N.
910                                                   887 
911 config DEBUG_PER_CPU_MAPS                         888 config DEBUG_PER_CPU_MAPS
912         bool "Debug access to per_cpu maps"       889         bool "Debug access to per_cpu maps"
913         depends on DEBUG_KERNEL                   890         depends on DEBUG_KERNEL
914         depends on SMP                            891         depends on SMP
915         help                                      892         help
916           Say Y to verify that the per_cpu map    893           Say Y to verify that the per_cpu map being accessed has
917           been set up. This adds a fair amount    894           been set up. This adds a fair amount of code to kernel memory
918           and decreases performance.              895           and decreases performance.
919                                                   896 
920           Say N if unsure.                        897           Say N if unsure.
921                                                   898 
922 config DEBUG_KMAP_LOCAL                           899 config DEBUG_KMAP_LOCAL
923         bool "Debug kmap_local temporary mappi    900         bool "Debug kmap_local temporary mappings"
924         depends on DEBUG_KERNEL && KMAP_LOCAL     901         depends on DEBUG_KERNEL && KMAP_LOCAL
925         help                                      902         help
926           This option enables additional error    903           This option enables additional error checking for the kmap_local
927           infrastructure.  Disable for product    904           infrastructure.  Disable for production use.
928                                                   905 
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP         906 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
930         bool                                      907         bool
931                                                   908 
932 config DEBUG_KMAP_LOCAL_FORCE_MAP                 909 config DEBUG_KMAP_LOCAL_FORCE_MAP
933         bool "Enforce kmap_local temporary map    910         bool "Enforce kmap_local temporary mappings"
934         depends on DEBUG_KERNEL && ARCH_SUPPOR    911         depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935         select KMAP_LOCAL                         912         select KMAP_LOCAL
936         select DEBUG_KMAP_LOCAL                   913         select DEBUG_KMAP_LOCAL
937         help                                      914         help
938           This option enforces temporary mappi    915           This option enforces temporary mappings through the kmap_local
939           mechanism for non-highmem pages and     916           mechanism for non-highmem pages and on non-highmem systems.
940           Disable this for production systems!    917           Disable this for production systems!
941                                                   918 
942 config DEBUG_HIGHMEM                              919 config DEBUG_HIGHMEM
943         bool "Highmem debugging"                  920         bool "Highmem debugging"
944         depends on DEBUG_KERNEL && HIGHMEM        921         depends on DEBUG_KERNEL && HIGHMEM
945         select DEBUG_KMAP_LOCAL_FORCE_MAP if A    922         select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
946         select DEBUG_KMAP_LOCAL                   923         select DEBUG_KMAP_LOCAL
947         help                                      924         help
948           This option enables additional error    925           This option enables additional error checking for high memory
949           systems.  Disable for production sys    926           systems.  Disable for production systems.
950                                                   927 
951 config HAVE_DEBUG_STACKOVERFLOW                   928 config HAVE_DEBUG_STACKOVERFLOW
952         bool                                      929         bool
953                                                   930 
954 config DEBUG_STACKOVERFLOW                        931 config DEBUG_STACKOVERFLOW
955         bool "Check for stack overflows"          932         bool "Check for stack overflows"
956         depends on DEBUG_KERNEL && HAVE_DEBUG_    933         depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957         help                                      934         help
958           Say Y here if you want to check for     935           Say Y here if you want to check for overflows of kernel, IRQ
959           and exception stacks (if your archit    936           and exception stacks (if your architecture uses them). This
960           option will show detailed messages i    937           option will show detailed messages if free stack space drops
961           below a certain limit.                  938           below a certain limit.
962                                                   939 
963           These kinds of bugs usually occur wh    940           These kinds of bugs usually occur when call-chains in the
964           kernel get too deep, especially when    941           kernel get too deep, especially when interrupts are
965           involved.                               942           involved.
966                                                   943 
967           Use this in cases where you see appa    944           Use this in cases where you see apparently random memory
968           corruption, especially if it appears    945           corruption, especially if it appears in 'struct thread_info'
969                                                   946 
970           If in doubt, say "N".                   947           If in doubt, say "N".
971                                                   948 
972 config CODE_TAGGING                            << 
973         bool                                   << 
974         select KALLSYMS                        << 
975                                                << 
976 config MEM_ALLOC_PROFILING                     << 
977         bool "Enable memory allocation profili << 
978         default n                              << 
979         depends on PROC_FS                     << 
980         depends on !DEBUG_FORCE_WEAK_PER_CPU   << 
981         select CODE_TAGGING                    << 
982         select PAGE_EXTENSION                  << 
983         select SLAB_OBJ_EXT                    << 
984         help                                   << 
985           Track allocation source code and rec << 
986           initiated at that code location. The << 
987           memory leaks with a low performance  << 
988                                                << 
989 config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT  << 
990         bool "Enable memory allocation profili << 
991         default y                              << 
992         depends on MEM_ALLOC_PROFILING         << 
993                                                << 
994 config MEM_ALLOC_PROFILING_DEBUG               << 
995         bool "Memory allocation profiler debug << 
996         default n                              << 
997         depends on MEM_ALLOC_PROFILING         << 
998         select MEM_ALLOC_PROFILING_ENABLED_BY_ << 
999         help                                   << 
1000           Adds warnings with helpful error me << 
1001           profiling.                          << 
1002                                               << 
1003 source "lib/Kconfig.kasan"                       949 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence"                      950 source "lib/Kconfig.kfence"
1005 source "lib/Kconfig.kmsan"                    << 
1006                                                  951 
1007 endmenu # "Memory Debugging"                     952 endmenu # "Memory Debugging"
1008                                                  953 
1009 config DEBUG_SHIRQ                               954 config DEBUG_SHIRQ
1010         bool "Debug shared IRQ handlers"         955         bool "Debug shared IRQ handlers"
1011         depends on DEBUG_KERNEL                  956         depends on DEBUG_KERNEL
1012         help                                     957         help
1013           Enable this to generate a spurious     958           Enable this to generate a spurious interrupt just before a shared
1014           interrupt handler is deregistered (    959           interrupt handler is deregistered (generating one when registering
1015           is currently disabled). Drivers nee    960           is currently disabled). Drivers need to handle this correctly. Some
1016           don't and need to be caught.           961           don't and need to be caught.
1017                                                  962 
1018 menu "Debug Oops, Lockups and Hangs"             963 menu "Debug Oops, Lockups and Hangs"
1019                                                  964 
1020 config PANIC_ON_OOPS                             965 config PANIC_ON_OOPS
1021         bool "Panic on Oops"                     966         bool "Panic on Oops"
1022         help                                     967         help
1023           Say Y here to enable the kernel to     968           Say Y here to enable the kernel to panic when it oopses. This
1024           has the same effect as setting oops    969           has the same effect as setting oops=panic on the kernel command
1025           line.                                  970           line.
1026                                                  971 
1027           This feature is useful to ensure th    972           This feature is useful to ensure that the kernel does not do
1028           anything erroneous after an oops wh    973           anything erroneous after an oops which could result in data
1029           corruption or other issues.            974           corruption or other issues.
1030                                                  975 
1031           Say N if unsure.                       976           Say N if unsure.
1032                                                  977 
1033 config PANIC_ON_OOPS_VALUE                       978 config PANIC_ON_OOPS_VALUE
1034         int                                      979         int
1035         range 0 1                                980         range 0 1
1036         default 0 if !PANIC_ON_OOPS              981         default 0 if !PANIC_ON_OOPS
1037         default 1 if PANIC_ON_OOPS               982         default 1 if PANIC_ON_OOPS
1038                                                  983 
1039 config PANIC_TIMEOUT                             984 config PANIC_TIMEOUT
1040         int "panic timeout"                      985         int "panic timeout"
1041         default 0                                986         default 0
1042         help                                     987         help
1043           Set the timeout value (in seconds)     988           Set the timeout value (in seconds) until a reboot occurs when
1044           the kernel panics. If n = 0, then w    989           the kernel panics. If n = 0, then we wait forever. A timeout
1045           value n > 0 will wait n seconds bef    990           value n > 0 will wait n seconds before rebooting, while a timeout
1046           value n < 0 will reboot immediately !! 991           value n < 0 will reboot immediately.
1047           with the kernel command line option << 
1048           /proc/sys/kernel/panic.             << 
1049                                                  992 
1050 config LOCKUP_DETECTOR                           993 config LOCKUP_DETECTOR
1051         bool                                     994         bool
1052                                                  995 
1053 config SOFTLOCKUP_DETECTOR                       996 config SOFTLOCKUP_DETECTOR
1054         bool "Detect Soft Lockups"               997         bool "Detect Soft Lockups"
1055         depends on DEBUG_KERNEL && !S390         998         depends on DEBUG_KERNEL && !S390
1056         select LOCKUP_DETECTOR                   999         select LOCKUP_DETECTOR
1057         help                                     1000         help
1058           Say Y here to enable the kernel to     1001           Say Y here to enable the kernel to act as a watchdog to detect
1059           soft lockups.                          1002           soft lockups.
1060                                                  1003 
1061           Softlockups are bugs that cause the    1004           Softlockups are bugs that cause the kernel to loop in kernel
1062           mode for more than 20 seconds, with    1005           mode for more than 20 seconds, without giving other tasks a
1063           chance to run.  The current stack t    1006           chance to run.  The current stack trace is displayed upon
1064           detection and the system will stay     1007           detection and the system will stay locked up.
1065                                                  1008 
1066 config SOFTLOCKUP_DETECTOR_INTR_STORM         << 
1067         bool "Detect Interrupt Storm in Soft  << 
1068         depends on SOFTLOCKUP_DETECTOR && IRQ << 
1069         select GENERIC_IRQ_STAT_SNAPSHOT      << 
1070         default y if NR_CPUS <= 128           << 
1071         help                                  << 
1072           Say Y here to enable the kernel to  << 
1073           during "soft lockups".              << 
1074                                               << 
1075           "soft lockups" can be caused by a v << 
1076           caused by an interrupt storm, then  << 
1077           be on the callstack. To detect this << 
1078           the CPU stats and the interrupt cou << 
1079                                               << 
1080 config BOOTPARAM_SOFTLOCKUP_PANIC                1009 config BOOTPARAM_SOFTLOCKUP_PANIC
1081         bool "Panic (Reboot) On Soft Lockups"    1010         bool "Panic (Reboot) On Soft Lockups"
1082         depends on SOFTLOCKUP_DETECTOR           1011         depends on SOFTLOCKUP_DETECTOR
1083         help                                     1012         help
1084           Say Y here to enable the kernel to     1013           Say Y here to enable the kernel to panic on "soft lockups",
1085           which are bugs that cause the kerne    1014           which are bugs that cause the kernel to loop in kernel
1086           mode for more than 20 seconds (conf    1015           mode for more than 20 seconds (configurable using the watchdog_thresh
1087           sysctl), without giving other tasks    1016           sysctl), without giving other tasks a chance to run.
1088                                                  1017 
1089           The panic can be used in combinatio    1018           The panic can be used in combination with panic_timeout,
1090           to cause the system to reboot autom    1019           to cause the system to reboot automatically after a
1091           lockup has been detected. This feat    1020           lockup has been detected. This feature is useful for
1092           high-availability systems that have    1021           high-availability systems that have uptime guarantees and
1093           where a lockup must be resolved ASA    1022           where a lockup must be resolved ASAP.
1094                                                  1023 
1095           Say N if unsure.                       1024           Say N if unsure.
1096                                                  1025 
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY         !! 1026 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
                                                   >> 1027         int
                                                   >> 1028         depends on SOFTLOCKUP_DETECTOR
                                                   >> 1029         range 0 1
                                                   >> 1030         default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
                                                   >> 1031         default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
                                                   >> 1032 
                                                   >> 1033 config HARDLOCKUP_DETECTOR_PERF
1098         bool                                     1034         bool
1099         depends on SMP                        !! 1035         select SOFTLOCKUP_DETECTOR
1100         default y                             << 
1101                                                  1036 
1102 #                                                1037 #
1103 # Global switch whether to build a hardlockup !! 1038 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 1039 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is  << 
1106 #                                                1040 #
1107 #       s390: it reported many false positive !! 1041 config HARDLOCKUP_CHECK_TIMESTAMP
                                                   >> 1042         bool
                                                   >> 1043 
1108 #                                                1044 #
1109 #       sparc64: has a custom implementation  !! 1045 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 #               hardlockup command line optio !! 1046 # lockup detector rather than the perf based detector.
1111 #                                                1047 #
1112 config HARDLOCKUP_DETECTOR                       1048 config HARDLOCKUP_DETECTOR
1113         bool "Detect Hard Lockups"               1049         bool "Detect Hard Lockups"
1114         depends on DEBUG_KERNEL && !S390 && ! !! 1050         depends on DEBUG_KERNEL && !S390
1115         depends on HAVE_HARDLOCKUP_DETECTOR_P !! 1051         depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1116         imply HARDLOCKUP_DETECTOR_PERF        << 
1117         imply HARDLOCKUP_DETECTOR_BUDDY       << 
1118         imply HARDLOCKUP_DETECTOR_ARCH        << 
1119         select LOCKUP_DETECTOR                   1052         select LOCKUP_DETECTOR
1120                                               !! 1053         select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
                                                   >> 1054         select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121         help                                     1055         help
1122           Say Y here to enable the kernel to     1056           Say Y here to enable the kernel to act as a watchdog to detect
1123           hard lockups.                          1057           hard lockups.
1124                                                  1058 
1125           Hardlockups are bugs that cause the    1059           Hardlockups are bugs that cause the CPU to loop in kernel mode
1126           for more than 10 seconds, without l    1060           for more than 10 seconds, without letting other interrupts have a
1127           chance to run.  The current stack t    1061           chance to run.  The current stack trace is displayed upon detection
1128           and the system will stay locked up.    1062           and the system will stay locked up.
1129                                                  1063 
1130 #                                             << 
1131 # Note that arch-specific variants are always << 
1132 #                                             << 
1133 config HARDLOCKUP_DETECTOR_PREFER_BUDDY       << 
1134         bool "Prefer the buddy CPU hardlockup << 
1135         depends on HARDLOCKUP_DETECTOR        << 
1136         depends on HAVE_HARDLOCKUP_DETECTOR_P << 
1137         depends on !HAVE_HARDLOCKUP_DETECTOR_ << 
1138         help                                  << 
1139           Say Y here to prefer the buddy hard << 
1140                                               << 
1141           With the buddy detector, each CPU u << 
1142           to check that the next CPU is proce << 
1143           verifying that a counter is increas << 
1144                                               << 
1145           This hardlockup detector is useful  << 
1146           an arch-specific hardlockup detecto << 
1147           for the hardlockup detector are bet << 
1148                                               << 
1149 config HARDLOCKUP_DETECTOR_PERF               << 
1150         bool                                  << 
1151         depends on HARDLOCKUP_DETECTOR        << 
1152         depends on HAVE_HARDLOCKUP_DETECTOR_P << 
1153         depends on !HAVE_HARDLOCKUP_DETECTOR_ << 
1154         select HARDLOCKUP_DETECTOR_COUNTS_HRT << 
1155                                               << 
1156 config HARDLOCKUP_DETECTOR_BUDDY              << 
1157         bool                                  << 
1158         depends on HARDLOCKUP_DETECTOR        << 
1159         depends on HAVE_HARDLOCKUP_DETECTOR_B << 
1160         depends on !HAVE_HARDLOCKUP_DETECTOR_ << 
1161         depends on !HAVE_HARDLOCKUP_DETECTOR_ << 
1162         select HARDLOCKUP_DETECTOR_COUNTS_HRT << 
1163                                               << 
1164 config HARDLOCKUP_DETECTOR_ARCH               << 
1165         bool                                  << 
1166         depends on HARDLOCKUP_DETECTOR        << 
1167         depends on HAVE_HARDLOCKUP_DETECTOR_A << 
1168         help                                  << 
1169           The arch-specific implementation of << 
1170           be used.                            << 
1171                                               << 
1172 #                                             << 
1173 # Both the "perf" and "buddy" hardlockup dete << 
1174 # interrupts. This config enables functions m << 
1175 #                                             << 
1176 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER     << 
1177         bool                                  << 
1178         select SOFTLOCKUP_DETECTOR            << 
1179                                               << 
1180 #                                             << 
1181 # Enables a timestamp based low pass filter t << 
1182 # hard lockup detection which runs too fast d << 
1183 #                                             << 
1184 config HARDLOCKUP_CHECK_TIMESTAMP             << 
1185         bool                                  << 
1186                                               << 
1187 config BOOTPARAM_HARDLOCKUP_PANIC                1064 config BOOTPARAM_HARDLOCKUP_PANIC
1188         bool "Panic (Reboot) On Hard Lockups"    1065         bool "Panic (Reboot) On Hard Lockups"
1189         depends on HARDLOCKUP_DETECTOR           1066         depends on HARDLOCKUP_DETECTOR
1190         help                                     1067         help
1191           Say Y here to enable the kernel to     1068           Say Y here to enable the kernel to panic on "hard lockups",
1192           which are bugs that cause the kerne    1069           which are bugs that cause the kernel to loop in kernel
1193           mode with interrupts disabled for m    1070           mode with interrupts disabled for more than 10 seconds (configurable
1194           using the watchdog_thresh sysctl).     1071           using the watchdog_thresh sysctl).
1195                                                  1072 
1196           Say N if unsure.                       1073           Say N if unsure.
1197                                                  1074 
                                                   >> 1075 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
                                                   >> 1076         int
                                                   >> 1077         depends on HARDLOCKUP_DETECTOR
                                                   >> 1078         range 0 1
                                                   >> 1079         default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
                                                   >> 1080         default 1 if BOOTPARAM_HARDLOCKUP_PANIC
                                                   >> 1081 
1198 config DETECT_HUNG_TASK                          1082 config DETECT_HUNG_TASK
1199         bool "Detect Hung Tasks"                 1083         bool "Detect Hung Tasks"
1200         depends on DEBUG_KERNEL                  1084         depends on DEBUG_KERNEL
1201         default SOFTLOCKUP_DETECTOR              1085         default SOFTLOCKUP_DETECTOR
1202         help                                     1086         help
1203           Say Y here to enable the kernel to     1087           Say Y here to enable the kernel to detect "hung tasks",
1204           which are bugs that cause the task     1088           which are bugs that cause the task to be stuck in
1205           uninterruptible "D" state indefinit    1089           uninterruptible "D" state indefinitely.
1206                                                  1090 
1207           When a hung task is detected, the k    1091           When a hung task is detected, the kernel will print the
1208           current stack trace (which you shou    1092           current stack trace (which you should report), but the
1209           task will stay in uninterruptible s    1093           task will stay in uninterruptible state. If lockdep is
1210           enabled then all held locks will al    1094           enabled then all held locks will also be reported. This
1211           feature has negligible overhead.       1095           feature has negligible overhead.
1212                                                  1096 
1213 config DEFAULT_HUNG_TASK_TIMEOUT                 1097 config DEFAULT_HUNG_TASK_TIMEOUT
1214         int "Default timeout for hung task de    1098         int "Default timeout for hung task detection (in seconds)"
1215         depends on DETECT_HUNG_TASK              1099         depends on DETECT_HUNG_TASK
1216         default 120                              1100         default 120
1217         help                                     1101         help
1218           This option controls the default ti    1102           This option controls the default timeout (in seconds) used
1219           to determine when a task has become    1103           to determine when a task has become non-responsive and should
1220           be considered hung.                    1104           be considered hung.
1221                                                  1105 
1222           It can be adjusted at runtime via t    1106           It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223           sysctl or by writing a value to        1107           sysctl or by writing a value to
1224           /proc/sys/kernel/hung_task_timeout_    1108           /proc/sys/kernel/hung_task_timeout_secs.
1225                                                  1109 
1226           A timeout of 0 disables the check.     1110           A timeout of 0 disables the check.  The default is two minutes.
1227           Keeping the default should be fine     1111           Keeping the default should be fine in most cases.
1228                                                  1112 
1229 config BOOTPARAM_HUNG_TASK_PANIC                 1113 config BOOTPARAM_HUNG_TASK_PANIC
1230         bool "Panic (Reboot) On Hung Tasks"      1114         bool "Panic (Reboot) On Hung Tasks"
1231         depends on DETECT_HUNG_TASK              1115         depends on DETECT_HUNG_TASK
1232         help                                     1116         help
1233           Say Y here to enable the kernel to     1117           Say Y here to enable the kernel to panic on "hung tasks",
1234           which are bugs that cause the kerne    1118           which are bugs that cause the kernel to leave a task stuck
1235           in uninterruptible "D" state.          1119           in uninterruptible "D" state.
1236                                                  1120 
1237           The panic can be used in combinatio    1121           The panic can be used in combination with panic_timeout,
1238           to cause the system to reboot autom    1122           to cause the system to reboot automatically after a
1239           hung task has been detected. This f    1123           hung task has been detected. This feature is useful for
1240           high-availability systems that have    1124           high-availability systems that have uptime guarantees and
1241           where a hung tasks must be resolved    1125           where a hung tasks must be resolved ASAP.
1242                                                  1126 
1243           Say N if unsure.                       1127           Say N if unsure.
1244                                                  1128 
                                                   >> 1129 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
                                                   >> 1130         int
                                                   >> 1131         depends on DETECT_HUNG_TASK
                                                   >> 1132         range 0 1
                                                   >> 1133         default 0 if !BOOTPARAM_HUNG_TASK_PANIC
                                                   >> 1134         default 1 if BOOTPARAM_HUNG_TASK_PANIC
                                                   >> 1135 
1245 config WQ_WATCHDOG                               1136 config WQ_WATCHDOG
1246         bool "Detect Workqueue Stalls"           1137         bool "Detect Workqueue Stalls"
1247         depends on DEBUG_KERNEL                  1138         depends on DEBUG_KERNEL
1248         help                                     1139         help
1249           Say Y here to enable stall detectio    1140           Say Y here to enable stall detection on workqueues.  If a
1250           worker pool doesn't make forward pr    1141           worker pool doesn't make forward progress on a pending work
1251           item for over a given amount of tim    1142           item for over a given amount of time, 30s by default, a
1252           warning message is printed along wi    1143           warning message is printed along with dump of workqueue
1253           state.  This can be configured thro    1144           state.  This can be configured through kernel parameter
1254           "workqueue.watchdog_thresh" and its    1145           "workqueue.watchdog_thresh" and its sysfs counterpart.
1255                                                  1146 
1256 config WQ_CPU_INTENSIVE_REPORT                << 
1257         bool "Report per-cpu work items which << 
1258         depends on DEBUG_KERNEL               << 
1259         help                                  << 
1260           Say Y here to enable reporting of c << 
1261           items that hog CPUs for longer than << 
1262           workqueue.cpu_intensive_thresh_us.  << 
1263           detects and excludes them from conc << 
1264           them from stalling other per-cpu wo << 
1265           triggering may not necessarily indi << 
1266           triggering likely indicates that th << 
1267           to use an unbound workqueue.        << 
1268                                               << 
1269 config TEST_LOCKUP                               1147 config TEST_LOCKUP
1270         tristate "Test module to generate loc    1148         tristate "Test module to generate lockups"
1271         depends on m                             1149         depends on m
1272         help                                     1150         help
1273           This builds the "test_lockup" modul    1151           This builds the "test_lockup" module that helps to make sure
1274           that watchdogs and lockup detectors    1152           that watchdogs and lockup detectors are working properly.
1275                                                  1153 
1276           Depending on module parameters it c    1154           Depending on module parameters it could emulate soft or hard
1277           lockup, "hung task", or locking arb    1155           lockup, "hung task", or locking arbitrary lock for a long time.
1278           Also it could generate series of lo    1156           Also it could generate series of lockups with cooling-down periods.
1279                                                  1157 
1280           If unsure, say N.                      1158           If unsure, say N.
1281                                                  1159 
1282 endmenu # "Debug lockups and hangs"              1160 endmenu # "Debug lockups and hangs"
1283                                                  1161 
1284 menu "Scheduler Debugging"                       1162 menu "Scheduler Debugging"
1285                                                  1163 
1286 config SCHED_DEBUG                               1164 config SCHED_DEBUG
1287         bool "Collect scheduler debugging inf    1165         bool "Collect scheduler debugging info"
1288         depends on DEBUG_KERNEL && DEBUG_FS   !! 1166         depends on DEBUG_KERNEL && PROC_FS
1289         default y                                1167         default y
1290         help                                     1168         help
1291           If you say Y here, the /sys/kernel/ !! 1169           If you say Y here, the /proc/sched_debug file will be provided
1292           that can help debug the scheduler.     1170           that can help debug the scheduler. The runtime overhead of this
1293           option is minimal.                     1171           option is minimal.
1294                                                  1172 
1295 config SCHED_INFO                                1173 config SCHED_INFO
1296         bool                                     1174         bool
1297         default n                                1175         default n
1298                                                  1176 
1299 config SCHEDSTATS                                1177 config SCHEDSTATS
1300         bool "Collect scheduler statistics"      1178         bool "Collect scheduler statistics"
1301         depends on PROC_FS                    !! 1179         depends on DEBUG_KERNEL && PROC_FS
1302         select SCHED_INFO                        1180         select SCHED_INFO
1303         help                                     1181         help
1304           If you say Y here, additional code     1182           If you say Y here, additional code will be inserted into the
1305           scheduler and related routines to c    1183           scheduler and related routines to collect statistics about
1306           scheduler behavior and provide them    1184           scheduler behavior and provide them in /proc/schedstat.  These
1307           stats may be useful for both tuning    1185           stats may be useful for both tuning and debugging the scheduler
1308           If you aren't debugging the schedul    1186           If you aren't debugging the scheduler or trying to tune a specific
1309           application, you can say N to avoid    1187           application, you can say N to avoid the very slight overhead
1310           this adds.                             1188           this adds.
1311                                                  1189 
1312 endmenu                                          1190 endmenu
1313                                                  1191 
1314 config DEBUG_TIMEKEEPING                         1192 config DEBUG_TIMEKEEPING
1315         bool "Enable extra timekeeping sanity    1193         bool "Enable extra timekeeping sanity checking"
1316         help                                     1194         help
1317           This option will enable additional     1195           This option will enable additional timekeeping sanity checks
1318           which may be helpful when diagnosin    1196           which may be helpful when diagnosing issues where timekeeping
1319           problems are suspected.                1197           problems are suspected.
1320                                                  1198 
1321           This may include checks in the time    1199           This may include checks in the timekeeping hotpaths, so this
1322           option may have a (very small) perf    1200           option may have a (very small) performance impact to some
1323           workloads.                             1201           workloads.
1324                                                  1202 
1325           If unsure, say N.                      1203           If unsure, say N.
1326                                                  1204 
1327 config DEBUG_PREEMPT                             1205 config DEBUG_PREEMPT
1328         bool "Debug preemptible kernel"          1206         bool "Debug preemptible kernel"
1329         depends on DEBUG_KERNEL && PREEMPTION    1207         depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
                                                   >> 1208         default y
1330         help                                     1209         help
1331           If you say Y here then the kernel w    1210           If you say Y here then the kernel will use a debug variant of the
1332           commonly used smp_processor_id() fu    1211           commonly used smp_processor_id() function and will print warnings
1333           if kernel code uses it in a preempt    1212           if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334           will detect preemption count underf    1213           will detect preemption count underflows.
1335                                                  1214 
1336           This option has potential to introd << 
1337           depending on workload as it trigger << 
1338           this_cpu operation. It should only  << 
1339                                               << 
1340 menu "Lock Debugging (spinlocks, mutexes, etc    1215 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341                                                  1216 
1342 config LOCK_DEBUGGING_SUPPORT                    1217 config LOCK_DEBUGGING_SUPPORT
1343         bool                                     1218         bool
1344         depends on TRACE_IRQFLAGS_SUPPORT &&     1219         depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345         default y                                1220         default y
1346                                                  1221 
1347 config PROVE_LOCKING                             1222 config PROVE_LOCKING
1348         bool "Lock debugging: prove locking c    1223         bool "Lock debugging: prove locking correctness"
1349         depends on DEBUG_KERNEL && LOCK_DEBUG    1224         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350         select LOCKDEP                           1225         select LOCKDEP
1351         select DEBUG_SPINLOCK                    1226         select DEBUG_SPINLOCK
1352         select DEBUG_MUTEXES if !PREEMPT_RT   !! 1227         select DEBUG_MUTEXES
1353         select DEBUG_RT_MUTEXES if RT_MUTEXES    1228         select DEBUG_RT_MUTEXES if RT_MUTEXES
1354         select DEBUG_RWSEMS if !PREEMPT_RT    !! 1229         select DEBUG_RWSEMS
1355         select DEBUG_WW_MUTEX_SLOWPATH           1230         select DEBUG_WW_MUTEX_SLOWPATH
1356         select DEBUG_LOCK_ALLOC                  1231         select DEBUG_LOCK_ALLOC
1357         select PREEMPT_COUNT if !ARCH_NO_PREE    1232         select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358         select TRACE_IRQFLAGS                    1233         select TRACE_IRQFLAGS
1359         default n                                1234         default n
1360         help                                     1235         help
1361          This feature enables the kernel to p    1236          This feature enables the kernel to prove that all locking
1362          that occurs in the kernel runtime is    1237          that occurs in the kernel runtime is mathematically
1363          correct: that under no circumstance     1238          correct: that under no circumstance could an arbitrary (and
1364          not yet triggered) combination of ob    1239          not yet triggered) combination of observed locking
1365          sequences (on an arbitrary number of    1240          sequences (on an arbitrary number of CPUs, running an
1366          arbitrary number of tasks and interr    1241          arbitrary number of tasks and interrupt contexts) cause a
1367          deadlock.                               1242          deadlock.
1368                                                  1243 
1369          In short, this feature enables the k    1244          In short, this feature enables the kernel to report locking
1370          related deadlocks before they actual    1245          related deadlocks before they actually occur.
1371                                                  1246 
1372          The proof does not depend on how har    1247          The proof does not depend on how hard and complex a
1373          deadlock scenario would be to trigge    1248          deadlock scenario would be to trigger: how many
1374          participant CPUs, tasks and irq-cont    1249          participant CPUs, tasks and irq-contexts would be needed
1375          for it to trigger. The proof also do    1250          for it to trigger. The proof also does not depend on
1376          timing: if a race and a resulting de    1251          timing: if a race and a resulting deadlock is possible
1377          theoretically (no matter how unlikel    1252          theoretically (no matter how unlikely the race scenario
1378          is), it will be proven so and will i    1253          is), it will be proven so and will immediately be
1379          reported by the kernel (once the eve    1254          reported by the kernel (once the event is observed that
1380          makes the deadlock theoretically pos    1255          makes the deadlock theoretically possible).
1381                                                  1256 
1382          If a deadlock is impossible (i.e. th    1257          If a deadlock is impossible (i.e. the locking rules, as
1383          observed by the kernel, are mathemat    1258          observed by the kernel, are mathematically correct), the
1384          kernel reports nothing.                 1259          kernel reports nothing.
1385                                                  1260 
1386          NOTE: this feature can also be enabl    1261          NOTE: this feature can also be enabled for rwlocks, mutexes
1387          and rwsems - in which case all depen    1262          and rwsems - in which case all dependencies between these
1388          different locking variants are obser    1263          different locking variants are observed and mapped too, and
1389          the proof of observed correctness is    1264          the proof of observed correctness is also maintained for an
1390          arbitrary combination of these separ    1265          arbitrary combination of these separate locking variants.
1391                                                  1266 
1392          For more details, see Documentation/    1267          For more details, see Documentation/locking/lockdep-design.rst.
1393                                                  1268 
1394 config PROVE_RAW_LOCK_NESTING                    1269 config PROVE_RAW_LOCK_NESTING
1395         bool "Enable raw_spinlock - spinlock     1270         bool "Enable raw_spinlock - spinlock nesting checks"
1396         depends on PROVE_LOCKING                 1271         depends on PROVE_LOCKING
1397         default n                                1272         default n
1398         help                                     1273         help
1399          Enable the raw_spinlock vs. spinlock    1274          Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400          that the lock nesting rules for PREE    1275          that the lock nesting rules for PREEMPT_RT enabled kernels are
1401          not violated.                           1276          not violated.
1402                                                  1277 
1403          NOTE: There are known nesting proble    1278          NOTE: There are known nesting problems. So if you enable this
1404          option expect lockdep splats until t    1279          option expect lockdep splats until these problems have been fully
1405          addressed which is work in progress.    1280          addressed which is work in progress. This config switch allows to
1406          identify and analyze these problems.    1281          identify and analyze these problems. It will be removed and the
1407          check permanently enabled once the m !! 1282          check permanentely enabled once the main issues have been fixed.
1408                                                  1283 
1409          If unsure, select N.                    1284          If unsure, select N.
1410                                                  1285 
1411 config LOCK_STAT                                 1286 config LOCK_STAT
1412         bool "Lock usage statistics"             1287         bool "Lock usage statistics"
1413         depends on DEBUG_KERNEL && LOCK_DEBUG    1288         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414         select LOCKDEP                           1289         select LOCKDEP
1415         select DEBUG_SPINLOCK                    1290         select DEBUG_SPINLOCK
1416         select DEBUG_MUTEXES if !PREEMPT_RT   !! 1291         select DEBUG_MUTEXES
1417         select DEBUG_RT_MUTEXES if RT_MUTEXES    1292         select DEBUG_RT_MUTEXES if RT_MUTEXES
1418         select DEBUG_LOCK_ALLOC                  1293         select DEBUG_LOCK_ALLOC
1419         default n                                1294         default n
1420         help                                     1295         help
1421          This feature enables tracking lock c    1296          This feature enables tracking lock contention points
1422                                                  1297 
1423          For more details, see Documentation/    1298          For more details, see Documentation/locking/lockstat.rst
1424                                                  1299 
1425          This also enables lock events requir    1300          This also enables lock events required by "perf lock",
1426          subcommand of perf.                     1301          subcommand of perf.
1427          If you want to use "perf lock", you     1302          If you want to use "perf lock", you also need to turn on
1428          CONFIG_EVENT_TRACING.                   1303          CONFIG_EVENT_TRACING.
1429                                                  1304 
1430          CONFIG_LOCK_STAT defines "contended"    1305          CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431          (CONFIG_LOCKDEP defines "acquire" an    1306          (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432                                                  1307 
1433 config DEBUG_RT_MUTEXES                          1308 config DEBUG_RT_MUTEXES
1434         bool "RT Mutex debugging, deadlock de    1309         bool "RT Mutex debugging, deadlock detection"
1435         depends on DEBUG_KERNEL && RT_MUTEXES    1310         depends on DEBUG_KERNEL && RT_MUTEXES
1436         help                                     1311         help
1437          This allows rt mutex semantics viola    1312          This allows rt mutex semantics violations and rt mutex related
1438          deadlocks (lockups) to be detected a    1313          deadlocks (lockups) to be detected and reported automatically.
1439                                                  1314 
1440 config DEBUG_SPINLOCK                            1315 config DEBUG_SPINLOCK
1441         bool "Spinlock and rw-lock debugging:    1316         bool "Spinlock and rw-lock debugging: basic checks"
1442         depends on DEBUG_KERNEL                  1317         depends on DEBUG_KERNEL
1443         select UNINLINE_SPIN_UNLOCK              1318         select UNINLINE_SPIN_UNLOCK
1444         help                                     1319         help
1445           Say Y here and build SMP to catch m    1320           Say Y here and build SMP to catch missing spinlock initialization
1446           and certain other kinds of spinlock    1321           and certain other kinds of spinlock errors commonly made.  This is
1447           best used in conjunction with the N    1322           best used in conjunction with the NMI watchdog so that spinlock
1448           deadlocks are also debuggable.         1323           deadlocks are also debuggable.
1449                                                  1324 
1450 config DEBUG_MUTEXES                             1325 config DEBUG_MUTEXES
1451         bool "Mutex debugging: basic checks"     1326         bool "Mutex debugging: basic checks"
1452         depends on DEBUG_KERNEL && !PREEMPT_R !! 1327         depends on DEBUG_KERNEL
1453         help                                     1328         help
1454          This feature allows mutex semantics     1329          This feature allows mutex semantics violations to be detected and
1455          reported.                               1330          reported.
1456                                                  1331 
1457 config DEBUG_WW_MUTEX_SLOWPATH                   1332 config DEBUG_WW_MUTEX_SLOWPATH
1458         bool "Wait/wound mutex debugging: Slo    1333         bool "Wait/wound mutex debugging: Slowpath testing"
1459         depends on DEBUG_KERNEL && LOCK_DEBUG    1334         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460         select DEBUG_LOCK_ALLOC                  1335         select DEBUG_LOCK_ALLOC
1461         select DEBUG_SPINLOCK                    1336         select DEBUG_SPINLOCK
1462         select DEBUG_MUTEXES if !PREEMPT_RT   !! 1337         select DEBUG_MUTEXES
1463         select DEBUG_RT_MUTEXES if PREEMPT_RT << 
1464         help                                     1338         help
1465          This feature enables slowpath testin    1339          This feature enables slowpath testing for w/w mutex users by
1466          injecting additional -EDEADLK wound/    1340          injecting additional -EDEADLK wound/backoff cases. Together with
1467          the full mutex checks enabled with (    1341          the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468          will test all possible w/w mutex int    1342          will test all possible w/w mutex interface abuse with the
1469          exception of simply not acquiring al    1343          exception of simply not acquiring all the required locks.
1470          Note that this feature can introduce    1344          Note that this feature can introduce significant overhead, so
1471          it really should not be enabled in a    1345          it really should not be enabled in a production or distro kernel,
1472          even a debug kernel.  If you are a d    1346          even a debug kernel.  If you are a driver writer, enable it.  If
1473          you are a distro, do not.               1347          you are a distro, do not.
1474                                                  1348 
1475 config DEBUG_RWSEMS                              1349 config DEBUG_RWSEMS
1476         bool "RW Semaphore debugging: basic c    1350         bool "RW Semaphore debugging: basic checks"
1477         depends on DEBUG_KERNEL && !PREEMPT_R !! 1351         depends on DEBUG_KERNEL
1478         help                                     1352         help
1479           This debugging feature allows misma    1353           This debugging feature allows mismatched rw semaphore locks
1480           and unlocks to be detected and repo    1354           and unlocks to be detected and reported.
1481                                                  1355 
1482 config DEBUG_LOCK_ALLOC                          1356 config DEBUG_LOCK_ALLOC
1483         bool "Lock debugging: detect incorrec    1357         bool "Lock debugging: detect incorrect freeing of live locks"
1484         depends on DEBUG_KERNEL && LOCK_DEBUG    1358         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485         select DEBUG_SPINLOCK                    1359         select DEBUG_SPINLOCK
1486         select DEBUG_MUTEXES if !PREEMPT_RT   !! 1360         select DEBUG_MUTEXES
1487         select DEBUG_RT_MUTEXES if RT_MUTEXES    1361         select DEBUG_RT_MUTEXES if RT_MUTEXES
1488         select LOCKDEP                           1362         select LOCKDEP
1489         help                                     1363         help
1490          This feature will check whether any     1364          This feature will check whether any held lock (spinlock, rwlock,
1491          mutex or rwsem) is incorrectly freed    1365          mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492          memory-freeing routines (kfree(), km    1366          memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493          vfree(), etc.), whether a live lock     1367          vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494          spin_lock_init()/mutex_init()/etc.,     1368          spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495          held during task exit.                  1369          held during task exit.
1496                                                  1370 
1497 config LOCKDEP                                   1371 config LOCKDEP
1498         bool                                     1372         bool
1499         depends on DEBUG_KERNEL && LOCK_DEBUG    1373         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500         select STACKTRACE                        1374         select STACKTRACE
1501         select KALLSYMS                          1375         select KALLSYMS
1502         select KALLSYMS_ALL                      1376         select KALLSYMS_ALL
1503                                                  1377 
1504 config LOCKDEP_SMALL                             1378 config LOCKDEP_SMALL
1505         bool                                     1379         bool
1506                                                  1380 
1507 config LOCKDEP_BITS                              1381 config LOCKDEP_BITS
1508         int "Bitsize for MAX_LOCKDEP_ENTRIES"    1382         int "Bitsize for MAX_LOCKDEP_ENTRIES"
1509         depends on LOCKDEP && !LOCKDEP_SMALL     1383         depends on LOCKDEP && !LOCKDEP_SMALL
1510         range 10 30                              1384         range 10 30
1511         default 15                               1385         default 15
1512         help                                     1386         help
1513           Try increasing this value if you hi    1387           Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1514                                                  1388 
1515 config LOCKDEP_CHAINS_BITS                       1389 config LOCKDEP_CHAINS_BITS
1516         int "Bitsize for MAX_LOCKDEP_CHAINS"     1390         int "Bitsize for MAX_LOCKDEP_CHAINS"
1517         depends on LOCKDEP && !LOCKDEP_SMALL     1391         depends on LOCKDEP && !LOCKDEP_SMALL
1518         range 10 30                              1392         range 10 30
1519         default 16                               1393         default 16
1520         help                                     1394         help
1521           Try increasing this value if you hi    1395           Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1522                                                  1396 
1523 config LOCKDEP_STACK_TRACE_BITS                  1397 config LOCKDEP_STACK_TRACE_BITS
1524         int "Bitsize for MAX_STACK_TRACE_ENTR    1398         int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1525         depends on LOCKDEP && !LOCKDEP_SMALL     1399         depends on LOCKDEP && !LOCKDEP_SMALL
1526         range 10 30                              1400         range 10 30
1527         default 19                               1401         default 19
1528         help                                     1402         help
1529           Try increasing this value if you hi    1403           Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1530                                                  1404 
1531 config LOCKDEP_STACK_TRACE_HASH_BITS             1405 config LOCKDEP_STACK_TRACE_HASH_BITS
1532         int "Bitsize for STACK_TRACE_HASH_SIZ    1406         int "Bitsize for STACK_TRACE_HASH_SIZE"
1533         depends on LOCKDEP && !LOCKDEP_SMALL     1407         depends on LOCKDEP && !LOCKDEP_SMALL
1534         range 10 30                              1408         range 10 30
1535         default 14                               1409         default 14
1536         help                                     1410         help
1537           Try increasing this value if you ne !! 1411           Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1538                                                  1412 
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS               1413 config LOCKDEP_CIRCULAR_QUEUE_BITS
1540         int "Bitsize for elements in circular    1414         int "Bitsize for elements in circular_queue struct"
1541         depends on LOCKDEP                       1415         depends on LOCKDEP
1542         range 10 30                              1416         range 10 30
1543         default 12                               1417         default 12
1544         help                                     1418         help
1545           Try increasing this value if you hi    1419           Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1546                                                  1420 
1547 config DEBUG_LOCKDEP                             1421 config DEBUG_LOCKDEP
1548         bool "Lock dependency engine debuggin    1422         bool "Lock dependency engine debugging"
1549         depends on DEBUG_KERNEL && LOCKDEP       1423         depends on DEBUG_KERNEL && LOCKDEP
1550         select DEBUG_IRQFLAGS                    1424         select DEBUG_IRQFLAGS
1551         help                                     1425         help
1552           If you say Y here, the lock depende    1426           If you say Y here, the lock dependency engine will do
1553           additional runtime checks to debug     1427           additional runtime checks to debug itself, at the price
1554           of more runtime overhead.              1428           of more runtime overhead.
1555                                                  1429 
1556 config DEBUG_ATOMIC_SLEEP                        1430 config DEBUG_ATOMIC_SLEEP
1557         bool "Sleep inside atomic section che    1431         bool "Sleep inside atomic section checking"
1558         select PREEMPT_COUNT                     1432         select PREEMPT_COUNT
1559         depends on DEBUG_KERNEL                  1433         depends on DEBUG_KERNEL
1560         depends on !ARCH_NO_PREEMPT              1434         depends on !ARCH_NO_PREEMPT
1561         help                                     1435         help
1562           If you say Y here, various routines    1436           If you say Y here, various routines which may sleep will become very
1563           noisy if they are called inside ato    1437           noisy if they are called inside atomic sections: when a spinlock is
1564           held, inside an rcu read side criti    1438           held, inside an rcu read side critical section, inside preempt disabled
1565           sections, inside an interrupt, etc.    1439           sections, inside an interrupt, etc...
1566                                                  1440 
1567 config DEBUG_LOCKING_API_SELFTESTS               1441 config DEBUG_LOCKING_API_SELFTESTS
1568         bool "Locking API boot-time self-test    1442         bool "Locking API boot-time self-tests"
1569         depends on DEBUG_KERNEL                  1443         depends on DEBUG_KERNEL
1570         help                                     1444         help
1571           Say Y here if you want the kernel t    1445           Say Y here if you want the kernel to run a short self-test during
1572           bootup. The self-test checks whethe    1446           bootup. The self-test checks whether common types of locking bugs
1573           are detected by debugging mechanism    1447           are detected by debugging mechanisms or not. (if you disable
1574           lock debugging then those bugs won' !! 1448           lock debugging then those bugs wont be detected of course.)
1575           The following locking APIs are cove    1449           The following locking APIs are covered: spinlocks, rwlocks,
1576           mutexes and rwsems.                    1450           mutexes and rwsems.
1577                                                  1451 
1578 config LOCK_TORTURE_TEST                         1452 config LOCK_TORTURE_TEST
1579         tristate "torture tests for locking"     1453         tristate "torture tests for locking"
1580         depends on DEBUG_KERNEL                  1454         depends on DEBUG_KERNEL
1581         select TORTURE_TEST                      1455         select TORTURE_TEST
1582         help                                     1456         help
1583           This option provides a kernel modul    1457           This option provides a kernel module that runs torture tests
1584           on kernel locking primitives.  The     1458           on kernel locking primitives.  The kernel module may be built
1585           after the fact on the running kerne    1459           after the fact on the running kernel to be tested, if desired.
1586                                                  1460 
1587           Say Y here if you want kernel locki    1461           Say Y here if you want kernel locking-primitive torture tests
1588           to be built into the kernel.           1462           to be built into the kernel.
1589           Say M if you want these torture tes    1463           Say M if you want these torture tests to build as a module.
1590           Say N if you are unsure.               1464           Say N if you are unsure.
1591                                                  1465 
1592 config WW_MUTEX_SELFTEST                         1466 config WW_MUTEX_SELFTEST
1593         tristate "Wait/wound mutex selftests"    1467         tristate "Wait/wound mutex selftests"
1594         help                                     1468         help
1595           This option provides a kernel modul    1469           This option provides a kernel module that runs tests on the
1596           on the struct ww_mutex locking API.    1470           on the struct ww_mutex locking API.
1597                                                  1471 
1598           It is recommended to enable DEBUG_W    1472           It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599           with this test harness.                1473           with this test harness.
1600                                                  1474 
1601           Say M if you want these self tests     1475           Say M if you want these self tests to build as a module.
1602           Say N if you are unsure.               1476           Say N if you are unsure.
1603                                                  1477 
1604 config SCF_TORTURE_TEST                          1478 config SCF_TORTURE_TEST
1605         tristate "torture tests for smp_call_    1479         tristate "torture tests for smp_call_function*()"
1606         depends on DEBUG_KERNEL                  1480         depends on DEBUG_KERNEL
1607         select TORTURE_TEST                      1481         select TORTURE_TEST
1608         help                                     1482         help
1609           This option provides a kernel modul    1483           This option provides a kernel module that runs torture tests
1610           on the smp_call_function() family o    1484           on the smp_call_function() family of primitives.  The kernel
1611           module may be built after the fact     1485           module may be built after the fact on the running kernel to
1612           be tested, if desired.                 1486           be tested, if desired.
1613                                                  1487 
1614 config CSD_LOCK_WAIT_DEBUG                       1488 config CSD_LOCK_WAIT_DEBUG
1615         bool "Debugging for csd_lock_wait(),     1489         bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616         depends on DEBUG_KERNEL                  1490         depends on DEBUG_KERNEL
1617         depends on 64BIT                         1491         depends on 64BIT
1618         default n                                1492         default n
1619         help                                     1493         help
1620           This option enables debug prints wh    1494           This option enables debug prints when CPUs are slow to respond
1621           to the smp_call_function*() IPI wra    1495           to the smp_call_function*() IPI wrappers.  These debug prints
1622           include the IPI handler function cu    1496           include the IPI handler function currently executing (if any)
1623           and relevant stack traces.             1497           and relevant stack traces.
1624                                                  1498 
1625 config CSD_LOCK_WAIT_DEBUG_DEFAULT            << 
1626         bool "Default csd_lock_wait() debuggi << 
1627         depends on CSD_LOCK_WAIT_DEBUG        << 
1628         depends on 64BIT                      << 
1629         default n                             << 
1630         help                                  << 
1631           This option causes the csdlock_debu << 
1632           default to 1 (basic debugging) inst << 
1633                                               << 
1634 endmenu # lock debugging                         1499 endmenu # lock debugging
1635                                                  1500 
1636 config TRACE_IRQFLAGS                            1501 config TRACE_IRQFLAGS
1637         depends on TRACE_IRQFLAGS_SUPPORT        1502         depends on TRACE_IRQFLAGS_SUPPORT
1638         bool                                     1503         bool
1639         help                                     1504         help
1640           Enables hooks to interrupt enabling    1505           Enables hooks to interrupt enabling and disabling for
1641           either tracing or lock debugging.      1506           either tracing or lock debugging.
1642                                                  1507 
1643 config TRACE_IRQFLAGS_NMI                        1508 config TRACE_IRQFLAGS_NMI
1644         def_bool y                               1509         def_bool y
1645         depends on TRACE_IRQFLAGS                1510         depends on TRACE_IRQFLAGS
1646         depends on TRACE_IRQFLAGS_NMI_SUPPORT    1511         depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647                                                  1512 
1648 config NMI_CHECK_CPU                          << 
1649         bool "Debugging for CPUs failing to r << 
1650         depends on DEBUG_KERNEL               << 
1651         depends on X86                        << 
1652         default n                             << 
1653         help                                  << 
1654           Enables debug prints when a CPU fai << 
1655           backtrace NMI.  These prints provid << 
1656           might legitimately be failing to re << 
1657           is offline of if ignore_nmis is set << 
1658                                               << 
1659 config DEBUG_IRQFLAGS                            1513 config DEBUG_IRQFLAGS
1660         bool "Debug IRQ flag manipulation"       1514         bool "Debug IRQ flag manipulation"
1661         help                                     1515         help
1662           Enables checks for potentially unsa    1516           Enables checks for potentially unsafe enabling or disabling of
1663           interrupts, such as calling raw_loc    1517           interrupts, such as calling raw_local_irq_restore() when interrupts
1664           are enabled.                           1518           are enabled.
1665                                                  1519 
1666 config STACKTRACE                                1520 config STACKTRACE
1667         bool "Stack backtrace support"           1521         bool "Stack backtrace support"
1668         depends on STACKTRACE_SUPPORT            1522         depends on STACKTRACE_SUPPORT
1669         help                                     1523         help
1670           This option causes the kernel to cr    1524           This option causes the kernel to create a /proc/pid/stack for
1671           every process, showing its current     1525           every process, showing its current stack trace.
1672           It is also used by various kernel d    1526           It is also used by various kernel debugging features that require
1673           stack trace generation.                1527           stack trace generation.
1674                                                  1528 
1675 config WARN_ALL_UNSEEDED_RANDOM                  1529 config WARN_ALL_UNSEEDED_RANDOM
1676         bool "Warn for all uses of unseeded r    1530         bool "Warn for all uses of unseeded randomness"
1677         default n                                1531         default n
1678         help                                     1532         help
1679           Some parts of the kernel contain bu    1533           Some parts of the kernel contain bugs relating to their use of
1680           cryptographically secure random num    1534           cryptographically secure random numbers before it's actually possible
1681           to generate those numbers securely.    1535           to generate those numbers securely. This setting ensures that these
1682           flaws don't go unnoticed, by enabli    1536           flaws don't go unnoticed, by enabling a message, should this ever
1683           occur. This will allow people with     1537           occur. This will allow people with obscure setups to know when things
1684           are going wrong, so that they might    1538           are going wrong, so that they might contact developers about fixing
1685           it.                                    1539           it.
1686                                                  1540 
1687           Unfortunately, on some models of so    1541           Unfortunately, on some models of some architectures getting
1688           a fully seeded CRNG is extremely di    1542           a fully seeded CRNG is extremely difficult, and so this can
1689           result in dmesg getting spammed for    1543           result in dmesg getting spammed for a surprisingly long
1690           time.  This is really bad from a se    1544           time.  This is really bad from a security perspective, and
1691           so architecture maintainers really     1545           so architecture maintainers really need to do what they can
1692           to get the CRNG seeded sooner after    1546           to get the CRNG seeded sooner after the system is booted.
1693           However, since users cannot do anyt    1547           However, since users cannot do anything actionable to
1694           address this, by default this optio !! 1548           address this, by default the kernel will issue only a single
                                                   >> 1549           warning for the first use of unseeded randomness.
1695                                                  1550 
1696           Say Y here if you want to receive w    1551           Say Y here if you want to receive warnings for all uses of
1697           unseeded randomness.  This will be     1552           unseeded randomness.  This will be of use primarily for
1698           those developers interested in impr    1553           those developers interested in improving the security of
1699           Linux kernels running on their arch    1554           Linux kernels running on their architecture (or
1700           subarchitecture).                      1555           subarchitecture).
1701                                                  1556 
1702 config DEBUG_KOBJECT                             1557 config DEBUG_KOBJECT
1703         bool "kobject debugging"                 1558         bool "kobject debugging"
1704         depends on DEBUG_KERNEL                  1559         depends on DEBUG_KERNEL
1705         help                                     1560         help
1706           If you say Y here, some extra kobje    1561           If you say Y here, some extra kobject debugging messages will be sent
1707           to the syslog.                         1562           to the syslog.
1708                                                  1563 
1709 config DEBUG_KOBJECT_RELEASE                     1564 config DEBUG_KOBJECT_RELEASE
1710         bool "kobject release debugging"         1565         bool "kobject release debugging"
1711         depends on DEBUG_OBJECTS_TIMERS          1566         depends on DEBUG_OBJECTS_TIMERS
1712         help                                     1567         help
1713           kobjects are reference counted obje    1568           kobjects are reference counted objects.  This means that their
1714           last reference count put is not pre    1569           last reference count put is not predictable, and the kobject can
1715           live on past the point at which a d !! 1570           live on past the point at which a driver decides to drop it's
1716           initial reference to the kobject ga    1571           initial reference to the kobject gained on allocation.  An
1717           example of this would be a struct d    1572           example of this would be a struct device which has just been
1718           unregistered.                          1573           unregistered.
1719                                                  1574 
1720           However, some buggy drivers assume     1575           However, some buggy drivers assume that after such an operation,
1721           the memory backing the kobject can     1576           the memory backing the kobject can be immediately freed.  This
1722           goes completely against the princip    1577           goes completely against the principles of a refcounted object.
1723                                                  1578 
1724           If you say Y here, the kernel will     1579           If you say Y here, the kernel will delay the release of kobjects
1725           on the last reference count to impr    1580           on the last reference count to improve the visibility of this
1726           kind of kobject release bug.           1581           kind of kobject release bug.
1727                                                  1582 
1728 config HAVE_DEBUG_BUGVERBOSE                     1583 config HAVE_DEBUG_BUGVERBOSE
1729         bool                                     1584         bool
1730                                                  1585 
1731 menu "Debug kernel data structures"              1586 menu "Debug kernel data structures"
1732                                                  1587 
1733 config DEBUG_LIST                                1588 config DEBUG_LIST
1734         bool "Debug linked list manipulation"    1589         bool "Debug linked list manipulation"
1735         depends on DEBUG_KERNEL               !! 1590         depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736         select LIST_HARDENED                  << 
1737         help                                     1591         help
1738           Enable this to turn on extended che !! 1592           Enable this to turn on extended checks in the linked-list
1739           routines.                           !! 1593           walking routines.
1740                                               << 
1741           This option trades better quality e << 
1742           is more suitable for kernel debuggi << 
1743           you should only enable CONFIG_LIST_ << 
1744                                                  1594 
1745           If unsure, say N.                      1595           If unsure, say N.
1746                                                  1596 
1747 config DEBUG_PLIST                               1597 config DEBUG_PLIST
1748         bool "Debug priority linked list mani    1598         bool "Debug priority linked list manipulation"
1749         depends on DEBUG_KERNEL                  1599         depends on DEBUG_KERNEL
1750         help                                     1600         help
1751           Enable this to turn on extended che    1601           Enable this to turn on extended checks in the priority-ordered
1752           linked-list (plist) walking routine    1602           linked-list (plist) walking routines.  This checks the entire
1753           list multiple times during each man    1603           list multiple times during each manipulation.
1754                                                  1604 
1755           If unsure, say N.                      1605           If unsure, say N.
1756                                                  1606 
1757 config DEBUG_SG                                  1607 config DEBUG_SG
1758         bool "Debug SG table operations"         1608         bool "Debug SG table operations"
1759         depends on DEBUG_KERNEL                  1609         depends on DEBUG_KERNEL
1760         help                                     1610         help
1761           Enable this to turn on checks on sc    1611           Enable this to turn on checks on scatter-gather tables. This can
1762           help find problems with drivers tha    1612           help find problems with drivers that do not properly initialize
1763           their sg tables.                       1613           their sg tables.
1764                                                  1614 
1765           If unsure, say N.                      1615           If unsure, say N.
1766                                                  1616 
1767 config DEBUG_NOTIFIERS                           1617 config DEBUG_NOTIFIERS
1768         bool "Debug notifier call chains"        1618         bool "Debug notifier call chains"
1769         depends on DEBUG_KERNEL                  1619         depends on DEBUG_KERNEL
1770         help                                     1620         help
1771           Enable this to turn on sanity check    1621           Enable this to turn on sanity checking for notifier call chains.
1772           This is most useful for kernel deve    1622           This is most useful for kernel developers to make sure that
1773           modules properly unregister themsel    1623           modules properly unregister themselves from notifier chains.
1774           This is a relatively cheap check bu    1624           This is a relatively cheap check but if you care about maximum
1775           performance, say N.                    1625           performance, say N.
1776                                                  1626 
1777 config DEBUG_CLOSURES                         !! 1627 config BUG_ON_DATA_CORRUPTION
1778         bool "Debug closures (bcache async wi !! 1628         bool "Trigger a BUG when data corruption is detected"
1779         depends on CLOSURES                   !! 1629         select DEBUG_LIST
1780         select DEBUG_FS                       !! 1630         help
1781         help                                  !! 1631           Select this option if the kernel should BUG when it encounters
1782           Keeps all active closures in a link !! 1632           data corruption in kernel memory structures when they get checked
1783           interface to list them, which makes !! 1633           for validity.
1784           operations that get stuck.          << 
1785                                                  1634 
1786 config DEBUG_MAPLE_TREE                       !! 1635           If unsure, say N.
1787         bool "Debug maple trees"              !! 1636 
                                                   >> 1637 endmenu
                                                   >> 1638 
                                                   >> 1639 config DEBUG_CREDENTIALS
                                                   >> 1640         bool "Debug credential management"
1788         depends on DEBUG_KERNEL                  1641         depends on DEBUG_KERNEL
1789         help                                     1642         help
1790           Enable maple tree debugging informa !! 1643           Enable this to turn on some debug checking for credential
                                                   >> 1644           management.  The additional code keeps track of the number of
                                                   >> 1645           pointers from task_structs to any given cred struct, and checks to
                                                   >> 1646           see that this number never exceeds the usage count of the cred
                                                   >> 1647           struct.
1791                                                  1648 
1792           If unsure, say N.                   !! 1649           Furthermore, if SELinux is enabled, this also checks that the
                                                   >> 1650           security pointer in the cred struct is never seen to be invalid.
1793                                                  1651 
1794 endmenu                                       !! 1652           If unsure, say N.
1795                                                  1653 
1796 source "kernel/rcu/Kconfig.debug"                1654 source "kernel/rcu/Kconfig.debug"
1797                                                  1655 
1798 config DEBUG_WQ_FORCE_RR_CPU                     1656 config DEBUG_WQ_FORCE_RR_CPU
1799         bool "Force round-robin CPU selection    1657         bool "Force round-robin CPU selection for unbound work items"
1800         depends on DEBUG_KERNEL                  1658         depends on DEBUG_KERNEL
1801         default n                                1659         default n
1802         help                                     1660         help
1803           Workqueue used to implicitly guaran    1661           Workqueue used to implicitly guarantee that work items queued
1804           without explicit CPU specified are     1662           without explicit CPU specified are put on the local CPU.  This
1805           guarantee is no longer true and whi    1663           guarantee is no longer true and while local CPU is still
1806           preferred work items may be put on     1664           preferred work items may be put on foreign CPUs.  Kernel
1807           parameter "workqueue.debug_force_rr    1665           parameter "workqueue.debug_force_rr_cpu" is added to force
1808           round-robin CPU selection to flush     1666           round-robin CPU selection to flush out usages which depend on the
1809           now broken guarantee.  This config     1667           now broken guarantee.  This config option enables the debug
1810           feature by default.  When enabled,     1668           feature by default.  When enabled, memory and cache locality will
1811           be impacted.                           1669           be impacted.
1812                                                  1670 
                                                   >> 1671 config DEBUG_BLOCK_EXT_DEVT
                                                   >> 1672         bool "Force extended block device numbers and spread them"
                                                   >> 1673         depends on DEBUG_KERNEL
                                                   >> 1674         depends on BLOCK
                                                   >> 1675         default n
                                                   >> 1676         help
                                                   >> 1677           BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
                                                   >> 1678           SOME DISTRIBUTIONS.  DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
                                                   >> 1679           YOU ARE DOING.  Distros, please enable this and fix whatever
                                                   >> 1680           is broken.
                                                   >> 1681 
                                                   >> 1682           Conventionally, block device numbers are allocated from
                                                   >> 1683           predetermined contiguous area.  However, extended block area
                                                   >> 1684           may introduce non-contiguous block device numbers.  This
                                                   >> 1685           option forces most block device numbers to be allocated from
                                                   >> 1686           the extended space and spreads them to discover kernel or
                                                   >> 1687           userland code paths which assume predetermined contiguous
                                                   >> 1688           device number allocation.
                                                   >> 1689 
                                                   >> 1690           Note that turning on this debug option shuffles all the
                                                   >> 1691           device numbers for all IDE and SCSI devices including libata
                                                   >> 1692           ones, so root partition specified using device number
                                                   >> 1693           directly (via rdev or root=MAJ:MIN) won't work anymore.
                                                   >> 1694           Textual device names (root=/dev/sdXn) will continue to work.
                                                   >> 1695 
                                                   >> 1696           Say N if you are unsure.
                                                   >> 1697 
1813 config CPU_HOTPLUG_STATE_CONTROL                 1698 config CPU_HOTPLUG_STATE_CONTROL
1814         bool "Enable CPU hotplug state contro    1699         bool "Enable CPU hotplug state control"
1815         depends on DEBUG_KERNEL                  1700         depends on DEBUG_KERNEL
1816         depends on HOTPLUG_CPU                   1701         depends on HOTPLUG_CPU
1817         default n                                1702         default n
1818         help                                     1703         help
1819           Allows to write steps between "offl    1704           Allows to write steps between "offline" and "online" to the CPUs
1820           sysfs target file so states can be     1705           sysfs target file so states can be stepped granular. This is a debug
1821           option for now as the hotplug machi    1706           option for now as the hotplug machinery cannot be stopped and
1822           restarted at arbitrary points yet.     1707           restarted at arbitrary points yet.
1823                                                  1708 
1824           Say N if your are unsure.              1709           Say N if your are unsure.
1825                                                  1710 
1826 config LATENCYTOP                                1711 config LATENCYTOP
1827         bool "Latency measuring infrastructur    1712         bool "Latency measuring infrastructure"
1828         depends on DEBUG_KERNEL                  1713         depends on DEBUG_KERNEL
1829         depends on STACKTRACE_SUPPORT            1714         depends on STACKTRACE_SUPPORT
1830         depends on PROC_FS                       1715         depends on PROC_FS
1831         depends on FRAME_POINTER || MIPS || P    1716         depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832         select KALLSYMS                          1717         select KALLSYMS
1833         select KALLSYMS_ALL                      1718         select KALLSYMS_ALL
1834         select STACKTRACE                        1719         select STACKTRACE
1835         select SCHEDSTATS                        1720         select SCHEDSTATS
1836         help                                     1721         help
1837           Enable this option if you want to u    1722           Enable this option if you want to use the LatencyTOP tool
1838           to find out which userspace is bloc    1723           to find out which userspace is blocking on what kernel operations.
1839                                                  1724 
1840 config DEBUG_CGROUP_REF                       << 
1841         bool "Disable inlining of cgroup css  << 
1842         depends on DEBUG_KERNEL               << 
1843         depends on CGROUPS                    << 
1844         depends on KPROBES                    << 
1845         default n                             << 
1846         help                                  << 
1847           Force cgroup css reference count fu << 
1848           that they can be kprobed for debugg << 
1849                                               << 
1850 source "kernel/trace/Kconfig"                    1725 source "kernel/trace/Kconfig"
1851                                                  1726 
1852 config PROVIDE_OHCI1394_DMA_INIT                 1727 config PROVIDE_OHCI1394_DMA_INIT
1853         bool "Remote debugging over FireWire     1728         bool "Remote debugging over FireWire early on boot"
1854         depends on PCI && X86                    1729         depends on PCI && X86
1855         help                                     1730         help
1856           If you want to debug problems which    1731           If you want to debug problems which hang or crash the kernel early
1857           on boot and the crashing machine ha    1732           on boot and the crashing machine has a FireWire port, you can use
1858           this feature to remotely access the    1733           this feature to remotely access the memory of the crashed machine
1859           over FireWire. This employs remote     1734           over FireWire. This employs remote DMA as part of the OHCI1394
1860           specification which is now the stan    1735           specification which is now the standard for FireWire controllers.
1861                                                  1736 
1862           With remote DMA, you can monitor th    1737           With remote DMA, you can monitor the printk buffer remotely using
1863           firescope and access all memory bel    1738           firescope and access all memory below 4GB using fireproxy from gdb.
1864           Even controlling a kernel debugger     1739           Even controlling a kernel debugger is possible using remote DMA.
1865                                                  1740 
1866           Usage:                                 1741           Usage:
1867                                                  1742 
1868           If ohci1394_dma=early is used as bo    1743           If ohci1394_dma=early is used as boot parameter, it will initialize
1869           all OHCI1394 controllers which are     1744           all OHCI1394 controllers which are found in the PCI config space.
1870                                                  1745 
1871           As all changes to the FireWire bus     1746           As all changes to the FireWire bus such as enabling and disabling
1872           devices cause a bus reset and there    1747           devices cause a bus reset and thereby disable remote DMA for all
1873           devices, be sure to have the cable     1748           devices, be sure to have the cable plugged and FireWire enabled on
1874           the debugging host before booting t    1749           the debugging host before booting the debug target for debugging.
1875                                                  1750 
1876           This code (~1k) is freed after boot    1751           This code (~1k) is freed after boot. By then, the firewire stack
1877           in charge of the OHCI-1394 controll    1752           in charge of the OHCI-1394 controllers should be used instead.
1878                                                  1753 
1879           See Documentation/core-api/debuggin    1754           See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880                                                  1755 
1881 source "samples/Kconfig"                         1756 source "samples/Kconfig"
1882                                                  1757 
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED                1758 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884         bool                                     1759         bool
1885                                                  1760 
1886 config STRICT_DEVMEM                             1761 config STRICT_DEVMEM
1887         bool "Filter access to /dev/mem"         1762         bool "Filter access to /dev/mem"
1888         depends on MMU && DEVMEM                 1763         depends on MMU && DEVMEM
1889         depends on ARCH_HAS_DEVMEM_IS_ALLOWED    1764         depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1890         default y if PPC || X86 || ARM64         1765         default y if PPC || X86 || ARM64
1891         help                                     1766         help
1892           If this option is disabled, you all    1767           If this option is disabled, you allow userspace (root) access to all
1893           of memory, including kernel and use    1768           of memory, including kernel and userspace memory. Accidental
1894           access to this is obviously disastr    1769           access to this is obviously disastrous, but specific access can
1895           be used by people debugging the ker    1770           be used by people debugging the kernel. Note that with PAT support
1896           enabled, even in this case there ar    1771           enabled, even in this case there are restrictions on /dev/mem
1897           use due to the cache aliasing requi    1772           use due to the cache aliasing requirements.
1898                                                  1773 
1899           If this option is switched on, and     1774           If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900           file only allows userspace access t    1775           file only allows userspace access to PCI space and the BIOS code and
1901           data regions.  This is sufficient f    1776           data regions.  This is sufficient for dosemu and X and all common
1902           users of /dev/mem.                     1777           users of /dev/mem.
1903                                                  1778 
1904           If in doubt, say Y.                    1779           If in doubt, say Y.
1905                                                  1780 
1906 config IO_STRICT_DEVMEM                          1781 config IO_STRICT_DEVMEM
1907         bool "Filter I/O access to /dev/mem"     1782         bool "Filter I/O access to /dev/mem"
1908         depends on STRICT_DEVMEM                 1783         depends on STRICT_DEVMEM
1909         help                                     1784         help
1910           If this option is disabled, you all    1785           If this option is disabled, you allow userspace (root) access to all
1911           io-memory regardless of whether a d    1786           io-memory regardless of whether a driver is actively using that
1912           range.  Accidental access to this i    1787           range.  Accidental access to this is obviously disastrous, but
1913           specific access can be used by peop    1788           specific access can be used by people debugging kernel drivers.
1914                                                  1789 
1915           If this option is switched on, the     1790           If this option is switched on, the /dev/mem file only allows
1916           userspace access to *idle* io-memor    1791           userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917           may break traditional users of /dev    1792           may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918           if the driver using a given range c    1793           if the driver using a given range cannot be disabled.
1919                                                  1794 
1920           If in doubt, say Y.                    1795           If in doubt, say Y.
1921                                                  1796 
1922 menu "$(SRCARCH) Debugging"                      1797 menu "$(SRCARCH) Debugging"
1923                                                  1798 
1924 source "arch/$(SRCARCH)/Kconfig.debug"           1799 source "arch/$(SRCARCH)/Kconfig.debug"
1925                                                  1800 
1926 endmenu                                          1801 endmenu
1927                                                  1802 
1928 menu "Kernel Testing and Coverage"               1803 menu "Kernel Testing and Coverage"
1929                                                  1804 
1930 source "lib/kunit/Kconfig"                       1805 source "lib/kunit/Kconfig"
1931                                                  1806 
1932 config NOTIFIER_ERROR_INJECTION                  1807 config NOTIFIER_ERROR_INJECTION
1933         tristate "Notifier error injection"      1808         tristate "Notifier error injection"
1934         depends on DEBUG_KERNEL                  1809         depends on DEBUG_KERNEL
1935         select DEBUG_FS                          1810         select DEBUG_FS
1936         help                                     1811         help
1937           This option provides the ability to    1812           This option provides the ability to inject artificial errors to
1938           specified notifier chain callbacks.    1813           specified notifier chain callbacks. It is useful to test the error
1939           handling of notifier call chain fai    1814           handling of notifier call chain failures.
1940                                                  1815 
1941           Say N if unsure.                       1816           Say N if unsure.
1942                                                  1817 
1943 config PM_NOTIFIER_ERROR_INJECT                  1818 config PM_NOTIFIER_ERROR_INJECT
1944         tristate "PM notifier error injection    1819         tristate "PM notifier error injection module"
1945         depends on PM && NOTIFIER_ERROR_INJEC    1820         depends on PM && NOTIFIER_ERROR_INJECTION
1946         default m if PM_DEBUG                    1821         default m if PM_DEBUG
1947         help                                     1822         help
1948           This option provides the ability to    1823           This option provides the ability to inject artificial errors to
1949           PM notifier chain callbacks.  It is    1824           PM notifier chain callbacks.  It is controlled through debugfs
1950           interface /sys/kernel/debug/notifie    1825           interface /sys/kernel/debug/notifier-error-inject/pm
1951                                                  1826 
1952           If the notifier call chain should b    1827           If the notifier call chain should be failed with some events
1953           notified, write the error code to "    1828           notified, write the error code to "actions/<notifier event>/error".
1954                                                  1829 
1955           Example: Inject PM suspend error (-    1830           Example: Inject PM suspend error (-12 = -ENOMEM)
1956                                                  1831 
1957           # cd /sys/kernel/debug/notifier-err    1832           # cd /sys/kernel/debug/notifier-error-inject/pm/
1958           # echo -12 > actions/PM_SUSPEND_PRE    1833           # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959           # echo mem > /sys/power/state          1834           # echo mem > /sys/power/state
1960           bash: echo: write error: Cannot all    1835           bash: echo: write error: Cannot allocate memory
1961                                                  1836 
1962           To compile this code as a module, c    1837           To compile this code as a module, choose M here: the module will
1963           be called pm-notifier-error-inject.    1838           be called pm-notifier-error-inject.
1964                                                  1839 
1965           If unsure, say N.                      1840           If unsure, say N.
1966                                                  1841 
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT         1842 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968         tristate "OF reconfig notifier error     1843         tristate "OF reconfig notifier error injection module"
1969         depends on OF_DYNAMIC && NOTIFIER_ERR    1844         depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970         help                                     1845         help
1971           This option provides the ability to    1846           This option provides the ability to inject artificial errors to
1972           OF reconfig notifier chain callback    1847           OF reconfig notifier chain callbacks.  It is controlled
1973           through debugfs interface under        1848           through debugfs interface under
1974           /sys/kernel/debug/notifier-error-in    1849           /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975                                                  1850 
1976           If the notifier call chain should b    1851           If the notifier call chain should be failed with some events
1977           notified, write the error code to "    1852           notified, write the error code to "actions/<notifier event>/error".
1978                                                  1853 
1979           To compile this code as a module, c    1854           To compile this code as a module, choose M here: the module will
1980           be called of-reconfig-notifier-erro    1855           be called of-reconfig-notifier-error-inject.
1981                                                  1856 
1982           If unsure, say N.                      1857           If unsure, say N.
1983                                                  1858 
1984 config NETDEV_NOTIFIER_ERROR_INJECT              1859 config NETDEV_NOTIFIER_ERROR_INJECT
1985         tristate "Netdev notifier error injec    1860         tristate "Netdev notifier error injection module"
1986         depends on NET && NOTIFIER_ERROR_INJE    1861         depends on NET && NOTIFIER_ERROR_INJECTION
1987         help                                     1862         help
1988           This option provides the ability to    1863           This option provides the ability to inject artificial errors to
1989           netdevice notifier chain callbacks.    1864           netdevice notifier chain callbacks.  It is controlled through debugfs
1990           interface /sys/kernel/debug/notifie    1865           interface /sys/kernel/debug/notifier-error-inject/netdev
1991                                                  1866 
1992           If the notifier call chain should b    1867           If the notifier call chain should be failed with some events
1993           notified, write the error code to "    1868           notified, write the error code to "actions/<notifier event>/error".
1994                                                  1869 
1995           Example: Inject netdevice mtu chang    1870           Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996                                                  1871 
1997           # cd /sys/kernel/debug/notifier-err    1872           # cd /sys/kernel/debug/notifier-error-inject/netdev
1998           # echo -22 > actions/NETDEV_CHANGEM    1873           # echo -22 > actions/NETDEV_CHANGEMTU/error
1999           # ip link set eth0 mtu 1024            1874           # ip link set eth0 mtu 1024
2000           RTNETLINK answers: Invalid argument    1875           RTNETLINK answers: Invalid argument
2001                                                  1876 
2002           To compile this code as a module, c    1877           To compile this code as a module, choose M here: the module will
2003           be called netdev-notifier-error-inj    1878           be called netdev-notifier-error-inject.
2004                                                  1879 
2005           If unsure, say N.                      1880           If unsure, say N.
2006                                                  1881 
2007 config FUNCTION_ERROR_INJECTION                  1882 config FUNCTION_ERROR_INJECTION
2008         bool "Fault-injections of functions"  !! 1883         def_bool y
2009         depends on HAVE_FUNCTION_ERROR_INJECT    1884         depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010         help                                  << 
2011           Add fault injections into various f << 
2012           ALLOW_ERROR_INJECTION() in the kern << 
2013           value of these functions. This is u << 
2014                                               << 
2015           If unsure, say N                    << 
2016                                                  1885 
2017 config FAULT_INJECTION                           1886 config FAULT_INJECTION
2018         bool "Fault-injection framework"         1887         bool "Fault-injection framework"
2019         depends on DEBUG_KERNEL                  1888         depends on DEBUG_KERNEL
2020         help                                     1889         help
2021           Provide fault-injection framework.     1890           Provide fault-injection framework.
2022           For more details, see Documentation    1891           For more details, see Documentation/fault-injection/.
2023                                                  1892 
2024 config FAILSLAB                                  1893 config FAILSLAB
2025         bool "Fault-injection capability for     1894         bool "Fault-injection capability for kmalloc"
2026         depends on FAULT_INJECTION               1895         depends on FAULT_INJECTION
                                                   >> 1896         depends on SLAB || SLUB
2027         help                                     1897         help
2028           Provide fault-injection capability     1898           Provide fault-injection capability for kmalloc.
2029                                                  1899 
2030 config FAIL_PAGE_ALLOC                           1900 config FAIL_PAGE_ALLOC
2031         bool "Fault-injection capability for     1901         bool "Fault-injection capability for alloc_pages()"
2032         depends on FAULT_INJECTION               1902         depends on FAULT_INJECTION
2033         help                                     1903         help
2034           Provide fault-injection capability     1904           Provide fault-injection capability for alloc_pages().
2035                                                  1905 
2036 config FAULT_INJECTION_USERCOPY                  1906 config FAULT_INJECTION_USERCOPY
2037         bool "Fault injection capability for     1907         bool "Fault injection capability for usercopy functions"
2038         depends on FAULT_INJECTION               1908         depends on FAULT_INJECTION
2039         help                                     1909         help
2040           Provides fault-injection capability    1910           Provides fault-injection capability to inject failures
2041           in usercopy functions (copy_from_us    1911           in usercopy functions (copy_from_user(), get_user(), ...).
2042                                                  1912 
2043 config FAIL_MAKE_REQUEST                         1913 config FAIL_MAKE_REQUEST
2044         bool "Fault-injection capability for     1914         bool "Fault-injection capability for disk IO"
2045         depends on FAULT_INJECTION && BLOCK      1915         depends on FAULT_INJECTION && BLOCK
2046         help                                     1916         help
2047           Provide fault-injection capability     1917           Provide fault-injection capability for disk IO.
2048                                                  1918 
2049 config FAIL_IO_TIMEOUT                           1919 config FAIL_IO_TIMEOUT
2050         bool "Fault-injection capability for     1920         bool "Fault-injection capability for faking disk interrupts"
2051         depends on FAULT_INJECTION && BLOCK      1921         depends on FAULT_INJECTION && BLOCK
2052         help                                     1922         help
2053           Provide fault-injection capability     1923           Provide fault-injection capability on end IO handling. This
2054           will make the block layer "forget"     1924           will make the block layer "forget" an interrupt as configured,
2055           thus exercising the error handling.    1925           thus exercising the error handling.
2056                                                  1926 
2057           Only works with drivers that use th    1927           Only works with drivers that use the generic timeout handling,
2058           for others it won't do anything.    !! 1928           for others it wont do anything.
2059                                                  1929 
2060 config FAIL_FUTEX                                1930 config FAIL_FUTEX
2061         bool "Fault-injection capability for     1931         bool "Fault-injection capability for futexes"
2062         select DEBUG_FS                          1932         select DEBUG_FS
2063         depends on FAULT_INJECTION && FUTEX      1933         depends on FAULT_INJECTION && FUTEX
2064         help                                     1934         help
2065           Provide fault-injection capability     1935           Provide fault-injection capability for futexes.
2066                                                  1936 
2067 config FAULT_INJECTION_DEBUG_FS                  1937 config FAULT_INJECTION_DEBUG_FS
2068         bool "Debugfs entries for fault-injec    1938         bool "Debugfs entries for fault-injection capabilities"
2069         depends on FAULT_INJECTION && SYSFS &    1939         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070         help                                     1940         help
2071           Enable configuration of fault-injec    1941           Enable configuration of fault-injection capabilities via debugfs.
2072                                                  1942 
2073 config FAIL_FUNCTION                             1943 config FAIL_FUNCTION
2074         bool "Fault-injection capability for     1944         bool "Fault-injection capability for functions"
2075         depends on FAULT_INJECTION_DEBUG_FS &    1945         depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076         help                                     1946         help
2077           Provide function-based fault-inject    1947           Provide function-based fault-injection capability.
2078           This will allow you to override a s    1948           This will allow you to override a specific function with a return
2079           with given return value. As a resul    1949           with given return value. As a result, function caller will see
2080           an error value and have to handle i    1950           an error value and have to handle it. This is useful to test the
2081           error handling in various subsystem    1951           error handling in various subsystems.
2082                                                  1952 
2083 config FAIL_MMC_REQUEST                          1953 config FAIL_MMC_REQUEST
2084         bool "Fault-injection capability for     1954         bool "Fault-injection capability for MMC IO"
2085         depends on FAULT_INJECTION_DEBUG_FS &    1955         depends on FAULT_INJECTION_DEBUG_FS && MMC
2086         help                                     1956         help
2087           Provide fault-injection capability     1957           Provide fault-injection capability for MMC IO.
2088           This will make the mmc core return     1958           This will make the mmc core return data errors. This is
2089           useful to test the error handling i    1959           useful to test the error handling in the mmc block device
2090           and to test how the mmc host driver    1960           and to test how the mmc host driver handles retries from
2091           the block device.                      1961           the block device.
2092                                                  1962 
2093 config FAIL_SUNRPC                            << 
2094         bool "Fault-injection capability for  << 
2095         depends on FAULT_INJECTION_DEBUG_FS & << 
2096         help                                  << 
2097           Provide fault-injection capability  << 
2098           its consumers.                      << 
2099                                               << 
2100 config FAULT_INJECTION_CONFIGFS               << 
2101         bool "Configfs interface for fault-in << 
2102         depends on FAULT_INJECTION            << 
2103         select CONFIGFS_FS                    << 
2104         help                                  << 
2105           This option allows configfs-based d << 
2106           fault-injection via configfs.  Each << 
2107           fault-injection can be made visible << 
2108           configfs group.                     << 
2109                                               << 
2110                                               << 
2111 config FAULT_INJECTION_STACKTRACE_FILTER         1963 config FAULT_INJECTION_STACKTRACE_FILTER
2112         bool "stacktrace filter for fault-inj    1964         bool "stacktrace filter for fault-injection capabilities"
2113         depends on FAULT_INJECTION            !! 1965         depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114         depends on (FAULT_INJECTION_DEBUG_FS  !! 1966         depends on !X86_64
2115         select STACKTRACE                        1967         select STACKTRACE
2116         depends on FRAME_POINTER || MIPS || P    1968         depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117         help                                     1969         help
2118           Provide stacktrace filter for fault    1970           Provide stacktrace filter for fault-injection capabilities
2119                                                  1971 
2120 config ARCH_HAS_KCOV                             1972 config ARCH_HAS_KCOV
2121         bool                                     1973         bool
2122         help                                     1974         help
2123           An architecture should select this     1975           An architecture should select this when it can successfully
2124           build and run with CONFIG_KCOV. Thi    1976           build and run with CONFIG_KCOV. This typically requires
2125           disabling instrumentation for some     1977           disabling instrumentation for some early boot code.
2126                                                  1978 
2127 config CC_HAS_SANCOV_TRACE_PC                    1979 config CC_HAS_SANCOV_TRACE_PC
2128         def_bool $(cc-option,-fsanitize-cover    1980         def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129                                                  1981 
2130                                                  1982 
2131 config KCOV                                      1983 config KCOV
2132         bool "Code coverage for fuzzing"         1984         bool "Code coverage for fuzzing"
2133         depends on ARCH_HAS_KCOV                 1985         depends on ARCH_HAS_KCOV
2134         depends on CC_HAS_SANCOV_TRACE_PC ||     1986         depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2135         depends on !ARCH_WANTS_NO_INSTR || HA << 
2136                    GCC_VERSION >= 120000 || C << 
2137         select DEBUG_FS                          1987         select DEBUG_FS
2138         select GCC_PLUGIN_SANCOV if !CC_HAS_S    1988         select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139         select OBJTOOL if HAVE_NOINSTR_HACK   << 
2140         help                                     1989         help
2141           KCOV exposes kernel code coverage i    1990           KCOV exposes kernel code coverage information in a form suitable
2142           for coverage-guided fuzzing (random    1991           for coverage-guided fuzzing (randomized testing).
2143                                                  1992 
                                                   >> 1993           If RANDOMIZE_BASE is enabled, PC values will not be stable across
                                                   >> 1994           different machines and across reboots. If you need stable PC values,
                                                   >> 1995           disable RANDOMIZE_BASE.
                                                   >> 1996 
2144           For more details, see Documentation    1997           For more details, see Documentation/dev-tools/kcov.rst.
2145                                                  1998 
2146 config KCOV_ENABLE_COMPARISONS                   1999 config KCOV_ENABLE_COMPARISONS
2147         bool "Enable comparison operands coll    2000         bool "Enable comparison operands collection by KCOV"
2148         depends on KCOV                          2001         depends on KCOV
2149         depends on $(cc-option,-fsanitize-cov    2002         depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150         help                                     2003         help
2151           KCOV also exposes operands of every    2004           KCOV also exposes operands of every comparison in the instrumented
2152           code along with operand sizes and P    2005           code along with operand sizes and PCs of the comparison instructions.
2153           These operands can be used by fuzzi    2006           These operands can be used by fuzzing engines to improve the quality
2154           of fuzzing coverage.                   2007           of fuzzing coverage.
2155                                                  2008 
2156 config KCOV_INSTRUMENT_ALL                       2009 config KCOV_INSTRUMENT_ALL
2157         bool "Instrument all code by default"    2010         bool "Instrument all code by default"
2158         depends on KCOV                          2011         depends on KCOV
2159         default y                                2012         default y
2160         help                                     2013         help
2161           If you are doing generic system cal    2014           If you are doing generic system call fuzzing (like e.g. syzkaller),
2162           then you will want to instrument th    2015           then you will want to instrument the whole kernel and you should
2163           say y here. If you are doing more t    2016           say y here. If you are doing more targeted fuzzing (like e.g.
2164           filesystem fuzzing with AFL) then y    2017           filesystem fuzzing with AFL) then you will want to enable coverage
2165           for more specific subsets of files,    2018           for more specific subsets of files, and should say n here.
2166                                                  2019 
2167 config KCOV_IRQ_AREA_SIZE                        2020 config KCOV_IRQ_AREA_SIZE
2168         hex "Size of interrupt coverage colle    2021         hex "Size of interrupt coverage collection area in words"
2169         depends on KCOV                          2022         depends on KCOV
2170         default 0x40000                          2023         default 0x40000
2171         help                                     2024         help
2172           KCOV uses preallocated per-cpu area    2025           KCOV uses preallocated per-cpu areas to collect coverage from
2173           soft interrupts. This specifies the    2026           soft interrupts. This specifies the size of those areas in the
2174           number of unsigned long words.         2027           number of unsigned long words.
2175                                                  2028 
2176 menuconfig RUNTIME_TESTING_MENU                  2029 menuconfig RUNTIME_TESTING_MENU
2177         bool "Runtime Testing"                   2030         bool "Runtime Testing"
2178         default y                             !! 2031         def_bool y
2179                                                  2032 
2180 if RUNTIME_TESTING_MENU                          2033 if RUNTIME_TESTING_MENU
2181                                                  2034 
2182 config TEST_DHRY                              << 
2183         tristate "Dhrystone benchmark test"   << 
2184         help                                  << 
2185           Enable this to include the Dhryston << 
2186           calculates the number of Dhrystones << 
2187           DMIPS (Dhrystone MIPS) obtained whe << 
2188           by 1757 (the number of Dhrystones p << 
2189           11/780, nominally a 1 MIPS machine) << 
2190                                               << 
2191           To run the benchmark, it needs to b << 
2192           the kernel command line (when built << 
2193           built-in or modular).               << 
2194                                               << 
2195           Run once during kernel boot:        << 
2196                                               << 
2197               test_dhry.run                   << 
2198                                               << 
2199           Set number of iterations from kerne << 
2200                                               << 
2201               test_dhry.iterations=<n>        << 
2202                                               << 
2203           Set number of iterations from users << 
2204                                               << 
2205               echo <n> > /sys/module/test_dhr << 
2206                                               << 
2207           Trigger manual run from userspace:  << 
2208                                               << 
2209               echo y > /sys/module/test_dhry/ << 
2210                                               << 
2211           If the number of iterations is <= 0 << 
2212           number of iterations (test runs for << 
2213           This process takes ca. 4s.          << 
2214                                               << 
2215           If unsure, say N.                   << 
2216                                               << 
2217 config LKDTM                                     2035 config LKDTM
2218         tristate "Linux Kernel Dump Test Tool    2036         tristate "Linux Kernel Dump Test Tool Module"
2219         depends on DEBUG_FS                      2037         depends on DEBUG_FS
2220         help                                     2038         help
2221         This module enables testing of the di    2039         This module enables testing of the different dumping mechanisms by
2222         inducing system failures at predefine    2040         inducing system failures at predefined crash points.
2223         If you don't need it: say N              2041         If you don't need it: say N
2224         Choose M here to compile this code as    2042         Choose M here to compile this code as a module. The module will be
2225         called lkdtm.                            2043         called lkdtm.
2226                                                  2044 
2227         Documentation on how to use the modul    2045         Documentation on how to use the module can be found in
2228         Documentation/fault-injection/provoke    2046         Documentation/fault-injection/provoke-crashes.rst
2229                                                  2047 
2230 config CPUMASK_KUNIT_TEST                     << 
2231         tristate "KUnit test for cpumask" if  << 
2232         depends on KUNIT                      << 
2233         default KUNIT_ALL_TESTS               << 
2234         help                                  << 
2235           Enable to turn on cpumask tests, ru << 
2236                                               << 
2237           For more information on KUnit and u << 
2238           to the KUnit documentation in Docum << 
2239                                               << 
2240           If unsure, say N.                   << 
2241                                               << 
2242 config TEST_LIST_SORT                            2048 config TEST_LIST_SORT
2243         tristate "Linked list sorting test" i !! 2049         tristate "Linked list sorting test"
2244         depends on KUNIT                      !! 2050         depends on DEBUG_KERNEL || m
2245         default KUNIT_ALL_TESTS               << 
2246         help                                     2051         help
2247           Enable this to turn on 'list_sort()    2052           Enable this to turn on 'list_sort()' function test. This test is
2248           executed only once during system bo    2053           executed only once during system boot (so affects only boot time),
2249           or at module load time.                2054           or at module load time.
2250                                                  2055 
2251           If unsure, say N.                      2056           If unsure, say N.
2252                                                  2057 
2253 config TEST_MIN_HEAP                             2058 config TEST_MIN_HEAP
2254         tristate "Min heap test"                 2059         tristate "Min heap test"
2255         depends on DEBUG_KERNEL || m             2060         depends on DEBUG_KERNEL || m
2256         help                                     2061         help
2257           Enable this to turn on min heap fun    2062           Enable this to turn on min heap function tests. This test is
2258           executed only once during system bo    2063           executed only once during system boot (so affects only boot time),
2259           or at module load time.                2064           or at module load time.
2260                                                  2065 
2261           If unsure, say N.                      2066           If unsure, say N.
2262                                                  2067 
2263 config TEST_SORT                                 2068 config TEST_SORT
2264         tristate "Array-based sort test" if ! !! 2069         tristate "Array-based sort test"
2265         depends on KUNIT                      !! 2070         depends on DEBUG_KERNEL || m
2266         default KUNIT_ALL_TESTS               << 
2267         help                                     2071         help
2268           This option enables the self-test f    2072           This option enables the self-test function of 'sort()' at boot,
2269           or at module load time.                2073           or at module load time.
2270                                                  2074 
2271           If unsure, say N.                      2075           If unsure, say N.
2272                                                  2076 
2273 config TEST_DIV64                                2077 config TEST_DIV64
2274         tristate "64bit/32bit division and mo    2078         tristate "64bit/32bit division and modulo test"
2275         depends on DEBUG_KERNEL || m             2079         depends on DEBUG_KERNEL || m
2276         help                                     2080         help
2277           Enable this to turn on 'do_div()' f    2081           Enable this to turn on 'do_div()' function test. This test is
2278           executed only once during system bo    2082           executed only once during system boot (so affects only boot time),
2279           or at module load time.                2083           or at module load time.
2280                                                  2084 
2281           If unsure, say N.                      2085           If unsure, say N.
2282                                                  2086 
2283 config TEST_IOV_ITER                          << 
2284         tristate "Test iov_iter operation" if << 
2285         depends on KUNIT                      << 
2286         depends on MMU                        << 
2287         default KUNIT_ALL_TESTS               << 
2288         help                                  << 
2289           Enable this to turn on testing of t << 
2290           (iov_iter). This test is executed o << 
2291           affects only boot time), or at modu << 
2292                                               << 
2293           If unsure, say N.                   << 
2294                                               << 
2295 config KPROBES_SANITY_TEST                       2087 config KPROBES_SANITY_TEST
2296         tristate "Kprobes sanity tests" if !K !! 2088         bool "Kprobes sanity tests"
2297         depends on DEBUG_KERNEL                  2089         depends on DEBUG_KERNEL
2298         depends on KPROBES                       2090         depends on KPROBES
2299         depends on KUNIT                      << 
2300         select STACKTRACE if ARCH_CORRECT_STA << 
2301         default KUNIT_ALL_TESTS               << 
2302         help                                     2091         help
2303           This option provides for testing ba    2092           This option provides for testing basic kprobes functionality on
2304           boot. Samples of kprobe and kretpro    2093           boot. Samples of kprobe and kretprobe are inserted and
2305           verified for functionality.            2094           verified for functionality.
2306                                                  2095 
2307           Say N if you are unsure.               2096           Say N if you are unsure.
2308                                                  2097 
2309 config FPROBE_SANITY_TEST                     << 
2310         bool "Self test for fprobe"           << 
2311         depends on DEBUG_KERNEL               << 
2312         depends on FPROBE                     << 
2313         depends on KUNIT=y                    << 
2314         help                                  << 
2315           This option will enable testing the << 
2316           A series of tests are made to verif << 
2317           properly.                           << 
2318                                               << 
2319           Say N if you are unsure.            << 
2320                                               << 
2321 config BACKTRACE_SELF_TEST                       2098 config BACKTRACE_SELF_TEST
2322         tristate "Self test for the backtrace    2099         tristate "Self test for the backtrace code"
2323         depends on DEBUG_KERNEL                  2100         depends on DEBUG_KERNEL
2324         help                                     2101         help
2325           This option provides a kernel modul    2102           This option provides a kernel module that can be used to test
2326           the kernel stack backtrace code. Th    2103           the kernel stack backtrace code. This option is not useful
2327           for distributions or general kernel    2104           for distributions or general kernels, but only for kernel
2328           developers working on architecture     2105           developers working on architecture code.
2329                                                  2106 
2330           Note that if you want to also test     2107           Note that if you want to also test saved backtraces, you will
2331           have to enable STACKTRACE as well.     2108           have to enable STACKTRACE as well.
2332                                                  2109 
2333           Say N if you are unsure.               2110           Say N if you are unsure.
2334                                                  2111 
2335 config TEST_REF_TRACKER                       << 
2336         tristate "Self test for reference tra << 
2337         depends on DEBUG_KERNEL && STACKTRACE << 
2338         select REF_TRACKER                    << 
2339         help                                  << 
2340           This option provides a kernel modul << 
2341           using reference tracker infrastruct << 
2342                                               << 
2343           Say N if you are unsure.            << 
2344                                               << 
2345 config RBTREE_TEST                               2112 config RBTREE_TEST
2346         tristate "Red-Black tree test"           2113         tristate "Red-Black tree test"
2347         depends on DEBUG_KERNEL                  2114         depends on DEBUG_KERNEL
2348         help                                     2115         help
2349           A benchmark measuring the performan    2116           A benchmark measuring the performance of the rbtree library.
2350           Also includes rbtree invariant chec    2117           Also includes rbtree invariant checks.
2351                                                  2118 
2352 config REED_SOLOMON_TEST                         2119 config REED_SOLOMON_TEST
2353         tristate "Reed-Solomon library test"     2120         tristate "Reed-Solomon library test"
2354         depends on DEBUG_KERNEL || m             2121         depends on DEBUG_KERNEL || m
2355         select REED_SOLOMON                      2122         select REED_SOLOMON
2356         select REED_SOLOMON_ENC16                2123         select REED_SOLOMON_ENC16
2357         select REED_SOLOMON_DEC16                2124         select REED_SOLOMON_DEC16
2358         help                                     2125         help
2359           This option enables the self-test f    2126           This option enables the self-test function of rslib at boot,
2360           or at module load time.                2127           or at module load time.
2361                                                  2128 
2362           If unsure, say N.                      2129           If unsure, say N.
2363                                                  2130 
2364 config INTERVAL_TREE_TEST                        2131 config INTERVAL_TREE_TEST
2365         tristate "Interval tree test"            2132         tristate "Interval tree test"
2366         depends on DEBUG_KERNEL                  2133         depends on DEBUG_KERNEL
2367         select INTERVAL_TREE                     2134         select INTERVAL_TREE
2368         help                                     2135         help
2369           A benchmark measuring the performan    2136           A benchmark measuring the performance of the interval tree library
2370                                                  2137 
2371 config PERCPU_TEST                               2138 config PERCPU_TEST
2372         tristate "Per cpu operations test"       2139         tristate "Per cpu operations test"
2373         depends on m && DEBUG_KERNEL             2140         depends on m && DEBUG_KERNEL
2374         help                                     2141         help
2375           Enable this option to build test mo    2142           Enable this option to build test module which validates per-cpu
2376           operations.                            2143           operations.
2377                                                  2144 
2378           If unsure, say N.                      2145           If unsure, say N.
2379                                                  2146 
2380 config ATOMIC64_SELFTEST                         2147 config ATOMIC64_SELFTEST
2381         tristate "Perform an atomic64_t self-    2148         tristate "Perform an atomic64_t self-test"
2382         help                                     2149         help
2383           Enable this option to test the atom    2150           Enable this option to test the atomic64_t functions at boot or
2384           at module load time.                   2151           at module load time.
2385                                                  2152 
2386           If unsure, say N.                      2153           If unsure, say N.
2387                                                  2154 
2388 config ASYNC_RAID6_TEST                          2155 config ASYNC_RAID6_TEST
2389         tristate "Self test for hardware acce    2156         tristate "Self test for hardware accelerated raid6 recovery"
2390         depends on ASYNC_RAID6_RECOV             2157         depends on ASYNC_RAID6_RECOV
2391         select ASYNC_MEMCPY                      2158         select ASYNC_MEMCPY
2392         help                                     2159         help
2393           This is a one-shot self test that p    2160           This is a one-shot self test that permutes through the
2394           recovery of all the possible two di    2161           recovery of all the possible two disk failure scenarios for a
2395           N-disk array.  Recovery is performe    2162           N-disk array.  Recovery is performed with the asynchronous
2396           raid6 recovery routines, and will o    2163           raid6 recovery routines, and will optionally use an offload
2397           engine if one is available.            2164           engine if one is available.
2398                                                  2165 
2399           If unsure, say N.                      2166           If unsure, say N.
2400                                                  2167 
2401 config TEST_HEXDUMP                              2168 config TEST_HEXDUMP
2402         tristate "Test functions located in t    2169         tristate "Test functions located in the hexdump module at runtime"
2403                                                  2170 
2404 config STRING_KUNIT_TEST                      !! 2171 config TEST_STRING_HELPERS
2405         tristate "KUnit test string functions !! 2172         tristate "Test functions located in the string_helpers module at runtime"
2406         depends on KUNIT                      << 
2407         default KUNIT_ALL_TESTS               << 
2408                                                  2173 
2409 config STRING_HELPERS_KUNIT_TEST              !! 2174 config TEST_STRSCPY
2410         tristate "KUnit test string helpers a !! 2175         tristate "Test strscpy*() family of functions at runtime"
2411         depends on KUNIT                      << 
2412         default KUNIT_ALL_TESTS               << 
2413                                                  2176 
2414 config TEST_KSTRTOX                              2177 config TEST_KSTRTOX
2415         tristate "Test kstrto*() family of fu    2178         tristate "Test kstrto*() family of functions at runtime"
2416                                                  2179 
2417 config TEST_PRINTF                               2180 config TEST_PRINTF
2418         tristate "Test printf() family of fun    2181         tristate "Test printf() family of functions at runtime"
2419                                                  2182 
2420 config TEST_SCANF                             << 
2421         tristate "Test scanf() family of func << 
2422                                               << 
2423 config TEST_BITMAP                               2183 config TEST_BITMAP
2424         tristate "Test bitmap_*() family of f    2184         tristate "Test bitmap_*() family of functions at runtime"
2425         help                                     2185         help
2426           Enable this option to test the bitm    2186           Enable this option to test the bitmap functions at boot.
2427                                                  2187 
2428           If unsure, say N.                      2188           If unsure, say N.
2429                                                  2189 
2430 config TEST_UUID                                 2190 config TEST_UUID
2431         tristate "Test functions located in t    2191         tristate "Test functions located in the uuid module at runtime"
2432                                                  2192 
2433 config TEST_XARRAY                               2193 config TEST_XARRAY
2434         tristate "Test the XArray code at run    2194         tristate "Test the XArray code at runtime"
2435                                                  2195 
2436 config TEST_MAPLE_TREE                        !! 2196 config TEST_OVERFLOW
2437         tristate "Test the Maple Tree code at !! 2197         tristate "Test check_*_overflow() functions at runtime"
2438         help                                  << 
2439           Enable this option to test the mapl << 
2440           when the module is loaded. Enable " << 
2441           more verbose output on failures.    << 
2442                                               << 
2443           If unsure, say N.                   << 
2444                                                  2198 
2445 config TEST_RHASHTABLE                           2199 config TEST_RHASHTABLE
2446         tristate "Perform selftest on resizab    2200         tristate "Perform selftest on resizable hash table"
2447         help                                     2201         help
2448           Enable this option to test the rhas    2202           Enable this option to test the rhashtable functions at boot.
2449                                                  2203 
2450           If unsure, say N.                      2204           If unsure, say N.
2451                                                  2205 
                                                   >> 2206 config TEST_HASH
                                                   >> 2207         tristate "Perform selftest on hash functions"
                                                   >> 2208         help
                                                   >> 2209           Enable this option to test the kernel's integer (<linux/hash.h>),
                                                   >> 2210           string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
                                                   >> 2211           hash functions on boot (or module load).
                                                   >> 2212 
                                                   >> 2213           This is intended to help people writing architecture-specific
                                                   >> 2214           optimized versions.  If unsure, say N.
                                                   >> 2215 
2452 config TEST_IDA                                  2216 config TEST_IDA
2453         tristate "Perform selftest on IDA fun    2217         tristate "Perform selftest on IDA functions"
2454                                                  2218 
2455 config TEST_PARMAN                               2219 config TEST_PARMAN
2456         tristate "Perform selftest on priorit    2220         tristate "Perform selftest on priority array manager"
2457         depends on PARMAN                        2221         depends on PARMAN
2458         help                                     2222         help
2459           Enable this option to test priority    2223           Enable this option to test priority array manager on boot
2460           (or module load).                      2224           (or module load).
2461                                                  2225 
2462           If unsure, say N.                      2226           If unsure, say N.
2463                                                  2227 
2464 config TEST_IRQ_TIMINGS                          2228 config TEST_IRQ_TIMINGS
2465         bool "IRQ timings selftest"              2229         bool "IRQ timings selftest"
2466         depends on IRQ_TIMINGS                   2230         depends on IRQ_TIMINGS
2467         help                                     2231         help
2468           Enable this option to test the irq     2232           Enable this option to test the irq timings code on boot.
2469                                                  2233 
2470           If unsure, say N.                      2234           If unsure, say N.
2471                                                  2235 
2472 config TEST_LKM                                  2236 config TEST_LKM
2473         tristate "Test module loading with 'h    2237         tristate "Test module loading with 'hello world' module"
2474         depends on m                             2238         depends on m
2475         help                                     2239         help
2476           This builds the "test_module" modul    2240           This builds the "test_module" module that emits "Hello, world"
2477           on printk when loaded. It is design    2241           on printk when loaded. It is designed to be used for basic
2478           evaluation of the module loading su    2242           evaluation of the module loading subsystem (for example when
2479           validating module verification). It    2243           validating module verification). It lacks any extra dependencies,
2480           and will not normally be loaded by     2244           and will not normally be loaded by the system unless explicitly
2481           requested by name.                     2245           requested by name.
2482                                                  2246 
2483           If unsure, say N.                      2247           If unsure, say N.
2484                                                  2248 
2485 config TEST_BITOPS                               2249 config TEST_BITOPS
2486         tristate "Test module for compilation    2250         tristate "Test module for compilation of bitops operations"
                                                   >> 2251         depends on m
2487         help                                     2252         help
2488           This builds the "test_bitops" modul    2253           This builds the "test_bitops" module that is much like the
2489           TEST_LKM module except that it does    2254           TEST_LKM module except that it does a basic exercise of the
2490           set/clear_bit macros and get_count_    2255           set/clear_bit macros and get_count_order/long to make sure there are
2491           no compiler warnings from C=1 spars    2256           no compiler warnings from C=1 sparse checker or -Wextra
2492           compilations. It has no dependencie    2257           compilations. It has no dependencies and doesn't run or load unless
2493           explicitly requested by name.  for     2258           explicitly requested by name.  for example: modprobe test_bitops.
2494                                                  2259 
2495           If unsure, say N.                      2260           If unsure, say N.
2496                                                  2261 
2497 config TEST_VMALLOC                              2262 config TEST_VMALLOC
2498         tristate "Test module for stress/perf    2263         tristate "Test module for stress/performance analysis of vmalloc allocator"
2499         default n                                2264         default n
2500        depends on MMU                            2265        depends on MMU
2501         depends on m                             2266         depends on m
2502         help                                     2267         help
2503           This builds the "test_vmalloc" modu    2268           This builds the "test_vmalloc" module that should be used for
2504           stress and performance analysis. So    2269           stress and performance analysis. So, any new change for vmalloc
2505           subsystem can be evaluated from per    2270           subsystem can be evaluated from performance and stability point
2506           of view.                               2271           of view.
2507                                                  2272 
2508           If unsure, say N.                      2273           If unsure, say N.
2509                                                  2274 
                                                   >> 2275 config TEST_USER_COPY
                                                   >> 2276         tristate "Test user/kernel boundary protections"
                                                   >> 2277         depends on m
                                                   >> 2278         help
                                                   >> 2279           This builds the "test_user_copy" module that runs sanity checks
                                                   >> 2280           on the copy_to/from_user infrastructure, making sure basic
                                                   >> 2281           user/kernel boundary testing is working. If it fails to load,
                                                   >> 2282           a regression has been detected in the user/kernel memory boundary
                                                   >> 2283           protections.
                                                   >> 2284 
                                                   >> 2285           If unsure, say N.
                                                   >> 2286 
2510 config TEST_BPF                                  2287 config TEST_BPF
2511         tristate "Test BPF filter functionali    2288         tristate "Test BPF filter functionality"
2512         depends on m && NET                      2289         depends on m && NET
2513         help                                     2290         help
2514           This builds the "test_bpf" module t    2291           This builds the "test_bpf" module that runs various test vectors
2515           against the BPF interpreter or BPF     2292           against the BPF interpreter or BPF JIT compiler depending on the
2516           current setting. This is in particu    2293           current setting. This is in particular useful for BPF JIT compiler
2517           development, but also to run regres    2294           development, but also to run regression tests against changes in
2518           the interpreter code. It also enabl    2295           the interpreter code. It also enables test stubs for eBPF maps and
2519           verifier used by user space verifie    2296           verifier used by user space verifier testsuite.
2520                                                  2297 
2521           If unsure, say N.                      2298           If unsure, say N.
2522                                                  2299 
2523 config TEST_BLACKHOLE_DEV                        2300 config TEST_BLACKHOLE_DEV
2524         tristate "Test blackhole netdev funct    2301         tristate "Test blackhole netdev functionality"
2525         depends on m && NET                      2302         depends on m && NET
2526         help                                     2303         help
2527           This builds the "test_blackhole_dev    2304           This builds the "test_blackhole_dev" module that validates the
2528           data path through this blackhole ne    2305           data path through this blackhole netdev.
2529                                                  2306 
2530           If unsure, say N.                      2307           If unsure, say N.
2531                                                  2308 
2532 config FIND_BIT_BENCHMARK                        2309 config FIND_BIT_BENCHMARK
2533         tristate "Test find_bit functions"       2310         tristate "Test find_bit functions"
2534         help                                     2311         help
2535           This builds the "test_find_bit" mod    2312           This builds the "test_find_bit" module that measure find_*_bit()
2536           functions performance.                 2313           functions performance.
2537                                                  2314 
2538           If unsure, say N.                      2315           If unsure, say N.
2539                                                  2316 
2540 config TEST_FIRMWARE                             2317 config TEST_FIRMWARE
2541         tristate "Test firmware loading via u    2318         tristate "Test firmware loading via userspace interface"
2542         depends on FW_LOADER                     2319         depends on FW_LOADER
2543         help                                     2320         help
2544           This builds the "test_firmware" mod    2321           This builds the "test_firmware" module that creates a userspace
2545           interface for testing firmware load    2322           interface for testing firmware loading. This can be used to
2546           control the triggering of firmware     2323           control the triggering of firmware loading without needing an
2547           actual firmware-using device. The c    2324           actual firmware-using device. The contents can be rechecked by
2548           userspace.                             2325           userspace.
2549                                                  2326 
2550           If unsure, say N.                      2327           If unsure, say N.
2551                                                  2328 
2552 config TEST_SYSCTL                               2329 config TEST_SYSCTL
2553         tristate "sysctl test driver"            2330         tristate "sysctl test driver"
2554         depends on PROC_SYSCTL                   2331         depends on PROC_SYSCTL
2555         help                                     2332         help
2556           This builds the "test_sysctl" modul    2333           This builds the "test_sysctl" module. This driver enables to test the
2557           proc sysctl interfaces available to    2334           proc sysctl interfaces available to drivers safely without affecting
2558           production knobs which might alter     2335           production knobs which might alter system functionality.
2559                                                  2336 
2560           If unsure, say N.                      2337           If unsure, say N.
2561                                                  2338 
2562 config BITFIELD_KUNIT                            2339 config BITFIELD_KUNIT
2563         tristate "KUnit test bitfield functio !! 2340         tristate "KUnit test bitfield functions at runtime"
2564         depends on KUNIT                         2341         depends on KUNIT
2565         default KUNIT_ALL_TESTS               << 
2566         help                                     2342         help
2567           Enable this option to test the bitf    2343           Enable this option to test the bitfield functions at boot.
2568                                                  2344 
2569           KUnit tests run during boot and out    2345           KUnit tests run during boot and output the results to the debug log
2570           in TAP format (http://testanything.    2346           in TAP format (http://testanything.org/). Only useful for kernel devs
2571           running the KUnit test harness, and    2347           running the KUnit test harness, and not intended for inclusion into a
2572           production build.                      2348           production build.
2573                                                  2349 
2574           For more information on KUnit and u    2350           For more information on KUnit and unit tests in general please refer
2575           to the KUnit documentation in Docum    2351           to the KUnit documentation in Documentation/dev-tools/kunit/.
2576                                                  2352 
2577           If unsure, say N.                      2353           If unsure, say N.
2578                                                  2354 
2579 config CHECKSUM_KUNIT                         << 
2580         tristate "KUnit test checksum functio << 
2581         depends on KUNIT                      << 
2582         default KUNIT_ALL_TESTS               << 
2583         help                                  << 
2584           Enable this option to test the chec << 
2585                                               << 
2586           KUnit tests run during boot and out << 
2587           in TAP format (http://testanything. << 
2588           running the KUnit test harness, and << 
2589           production build.                   << 
2590                                               << 
2591           For more information on KUnit and u << 
2592           to the KUnit documentation in Docum << 
2593                                               << 
2594           If unsure, say N.                   << 
2595                                               << 
2596 config HASH_KUNIT_TEST                        << 
2597         tristate "KUnit Test for integer hash << 
2598         depends on KUNIT                      << 
2599         default KUNIT_ALL_TESTS               << 
2600         help                                  << 
2601           Enable this option to test the kern << 
2602           integer (<linux/hash.h>) hash funct << 
2603                                               << 
2604           KUnit tests run during boot and out << 
2605           in TAP format (https://testanything << 
2606           running the KUnit test harness, and << 
2607           production build.                   << 
2608                                               << 
2609           For more information on KUnit and u << 
2610           to the KUnit documentation in Docum << 
2611                                               << 
2612           This is intended to help people wri << 
2613           optimized versions. If unsure, say  << 
2614                                               << 
2615 config RESOURCE_KUNIT_TEST                       2355 config RESOURCE_KUNIT_TEST
2616         tristate "KUnit test for resource API !! 2356         tristate "KUnit test for resource API"
2617         depends on KUNIT                         2357         depends on KUNIT
2618         default KUNIT_ALL_TESTS               << 
2619         help                                     2358         help
2620           This builds the resource API unit t    2359           This builds the resource API unit test.
2621           Tests the logic of API provided by     2360           Tests the logic of API provided by resource.c and ioport.h.
2622           For more information on KUnit and u    2361           For more information on KUnit and unit tests in general please refer
2623           to the KUnit documentation in Docum    2362           to the KUnit documentation in Documentation/dev-tools/kunit/.
2624                                                  2363 
2625           If unsure, say N.                      2364           If unsure, say N.
2626                                                  2365 
2627 config SYSCTL_KUNIT_TEST                         2366 config SYSCTL_KUNIT_TEST
2628         tristate "KUnit test for sysctl" if !    2367         tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629         depends on KUNIT                         2368         depends on KUNIT
2630         default KUNIT_ALL_TESTS                  2369         default KUNIT_ALL_TESTS
2631         help                                     2370         help
2632           This builds the proc sysctl unit te    2371           This builds the proc sysctl unit test, which runs on boot.
2633           Tests the API contract and implemen    2372           Tests the API contract and implementation correctness of sysctl.
2634           For more information on KUnit and u    2373           For more information on KUnit and unit tests in general please refer
2635           to the KUnit documentation in Docum    2374           to the KUnit documentation in Documentation/dev-tools/kunit/.
2636                                                  2375 
2637           If unsure, say N.                      2376           If unsure, say N.
2638                                                  2377 
2639 config LIST_KUNIT_TEST                           2378 config LIST_KUNIT_TEST
2640         tristate "KUnit Test for Kernel Linke    2379         tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641         depends on KUNIT                         2380         depends on KUNIT
2642         default KUNIT_ALL_TESTS                  2381         default KUNIT_ALL_TESTS
2643         help                                     2382         help
2644           This builds the linked list KUnit t    2383           This builds the linked list KUnit test suite.
2645           It tests that the API and basic fun    2384           It tests that the API and basic functionality of the list_head type
2646           and associated macros.                 2385           and associated macros.
2647                                                  2386 
2648           KUnit tests run during boot and out    2387           KUnit tests run during boot and output the results to the debug log
2649           in TAP format (https://testanything    2388           in TAP format (https://testanything.org/). Only useful for kernel devs
2650           running the KUnit test harness, and    2389           running the KUnit test harness, and not intended for inclusion into a
2651           production build.                      2390           production build.
2652                                                  2391 
2653           For more information on KUnit and u    2392           For more information on KUnit and unit tests in general please refer
2654           to the KUnit documentation in Docum    2393           to the KUnit documentation in Documentation/dev-tools/kunit/.
2655                                                  2394 
2656           If unsure, say N.                      2395           If unsure, say N.
2657                                                  2396 
2658 config HASHTABLE_KUNIT_TEST                   << 
2659         tristate "KUnit Test for Kernel Hasht << 
2660         depends on KUNIT                      << 
2661         default KUNIT_ALL_TESTS               << 
2662         help                                  << 
2663           This builds the hashtable KUnit tes << 
2664           It tests the basic functionality of << 
2665           include/linux/hashtable.h. For more << 
2666           unit tests in general please refer  << 
2667           in Documentation/dev-tools/kunit/.  << 
2668                                               << 
2669           If unsure, say N.                   << 
2670                                               << 
2671 config LINEAR_RANGES_TEST                        2397 config LINEAR_RANGES_TEST
2672         tristate "KUnit test for linear_range    2398         tristate "KUnit test for linear_ranges"
2673         depends on KUNIT                         2399         depends on KUNIT
2674         select LINEAR_RANGES                     2400         select LINEAR_RANGES
2675         help                                     2401         help
2676           This builds the linear_ranges unit     2402           This builds the linear_ranges unit test, which runs on boot.
2677           Tests the linear_ranges logic corre    2403           Tests the linear_ranges logic correctness.
2678           For more information on KUnit and u    2404           For more information on KUnit and unit tests in general please refer
2679           to the KUnit documentation in Docum    2405           to the KUnit documentation in Documentation/dev-tools/kunit/.
2680                                                  2406 
2681           If unsure, say N.                      2407           If unsure, say N.
2682                                                  2408 
2683 config CMDLINE_KUNIT_TEST                        2409 config CMDLINE_KUNIT_TEST
2684         tristate "KUnit test for cmdline API" !! 2410         tristate "KUnit test for cmdline API"
2685         depends on KUNIT                         2411         depends on KUNIT
2686         default KUNIT_ALL_TESTS               << 
2687         help                                     2412         help
2688           This builds the cmdline API unit te    2413           This builds the cmdline API unit test.
2689           Tests the logic of API provided by     2414           Tests the logic of API provided by cmdline.c.
2690           For more information on KUnit and u    2415           For more information on KUnit and unit tests in general please refer
2691           to the KUnit documentation in Docum    2416           to the KUnit documentation in Documentation/dev-tools/kunit/.
2692                                                  2417 
2693           If unsure, say N.                      2418           If unsure, say N.
2694                                                  2419 
2695 config BITS_TEST                                 2420 config BITS_TEST
2696         tristate "KUnit test for bits.h" if ! !! 2421         tristate "KUnit test for bits.h"
2697         depends on KUNIT                         2422         depends on KUNIT
2698         default KUNIT_ALL_TESTS               << 
2699         help                                     2423         help
2700           This builds the bits unit test.        2424           This builds the bits unit test.
2701           Tests the logic of macros defined i    2425           Tests the logic of macros defined in bits.h.
2702           For more information on KUnit and u    2426           For more information on KUnit and unit tests in general please refer
2703           to the KUnit documentation in Docum    2427           to the KUnit documentation in Documentation/dev-tools/kunit/.
2704                                                  2428 
2705           If unsure, say N.                      2429           If unsure, say N.
2706                                                  2430 
2707 config SLUB_KUNIT_TEST                        << 
2708         tristate "KUnit test for SLUB cache e << 
2709         depends on SLUB_DEBUG && KUNIT        << 
2710         default KUNIT_ALL_TESTS               << 
2711         help                                  << 
2712           This builds SLUB allocator unit tes << 
2713           Tests SLUB cache debugging function << 
2714           For more information on KUnit and u << 
2715           to the KUnit documentation in Docum << 
2716                                               << 
2717           If unsure, say N.                   << 
2718                                               << 
2719 config RATIONAL_KUNIT_TEST                    << 
2720         tristate "KUnit test for rational.c"  << 
2721         depends on KUNIT && RATIONAL          << 
2722         default KUNIT_ALL_TESTS               << 
2723         help                                  << 
2724           This builds the rational math unit  << 
2725           For more information on KUnit and u << 
2726           to the KUnit documentation in Docum << 
2727                                               << 
2728           If unsure, say N.                   << 
2729                                               << 
2730 config MEMCPY_KUNIT_TEST                      << 
2731         tristate "Test memcpy(), memmove(), a << 
2732         depends on KUNIT                      << 
2733         default KUNIT_ALL_TESTS               << 
2734         help                                  << 
2735           Builds unit tests for memcpy(), mem << 
2736           For more information on KUnit and u << 
2737           to the KUnit documentation in Docum << 
2738                                               << 
2739           If unsure, say N.                   << 
2740                                               << 
2741 config IS_SIGNED_TYPE_KUNIT_TEST              << 
2742         tristate "Test is_signed_type() macro << 
2743         depends on KUNIT                      << 
2744         default KUNIT_ALL_TESTS               << 
2745         help                                  << 
2746           Builds unit tests for the is_signed << 
2747                                               << 
2748           For more information on KUnit and u << 
2749           to the KUnit documentation in Docum << 
2750                                               << 
2751           If unsure, say N.                   << 
2752                                               << 
2753 config OVERFLOW_KUNIT_TEST                    << 
2754         tristate "Test check_*_overflow() fun << 
2755         depends on KUNIT                      << 
2756         default KUNIT_ALL_TESTS               << 
2757         help                                  << 
2758           Builds unit tests for the check_*_o << 
2759           related functions.                  << 
2760                                               << 
2761           For more information on KUnit and u << 
2762           to the KUnit documentation in Docum << 
2763                                               << 
2764           If unsure, say N.                   << 
2765                                               << 
2766 config STACKINIT_KUNIT_TEST                   << 
2767         tristate "Test level of stack variabl << 
2768         depends on KUNIT                      << 
2769         default KUNIT_ALL_TESTS               << 
2770         help                                  << 
2771           Test if the kernel is zero-initiali << 
2772           padding. Coverage is controlled by  << 
2773           CONFIG_INIT_STACK_ALL_PATTERN, CONF << 
2774           CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFI << 
2775           or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYR << 
2776                                               << 
2777 config FORTIFY_KUNIT_TEST                     << 
2778         tristate "Test fortified str*() and m << 
2779         depends on KUNIT                      << 
2780         default KUNIT_ALL_TESTS               << 
2781         help                                  << 
2782           Builds unit tests for checking inte << 
2783           by the str*() and mem*() family of  << 
2784           traps of FORTIFY_SOURCE, see LKDTM' << 
2785                                               << 
2786 config HW_BREAKPOINT_KUNIT_TEST               << 
2787         bool "Test hw_breakpoint constraints  << 
2788         depends on HAVE_HW_BREAKPOINT         << 
2789         depends on KUNIT=y                    << 
2790         default KUNIT_ALL_TESTS               << 
2791         help                                  << 
2792           Tests for hw_breakpoint constraints << 
2793                                               << 
2794           If unsure, say N.                   << 
2795                                               << 
2796 config SIPHASH_KUNIT_TEST                     << 
2797         tristate "Perform selftest on siphash << 
2798         depends on KUNIT                      << 
2799         default KUNIT_ALL_TESTS               << 
2800         help                                  << 
2801           Enable this option to test the kern << 
2802           functions on boot (or module load). << 
2803                                               << 
2804           This is intended to help people wri << 
2805           optimized versions.  If unsure, say << 
2806                                               << 
2807 config USERCOPY_KUNIT_TEST                    << 
2808         tristate "KUnit Test for user/kernel  << 
2809         depends on KUNIT                      << 
2810         default KUNIT_ALL_TESTS               << 
2811         help                                  << 
2812           This builds the "usercopy_kunit" mo << 
2813           on the copy_to/from_user infrastruc << 
2814           user/kernel boundary testing is wor << 
2815                                               << 
2816 config TEST_UDELAY                               2431 config TEST_UDELAY
2817         tristate "udelay test driver"            2432         tristate "udelay test driver"
2818         help                                     2433         help
2819           This builds the "udelay_test" modul    2434           This builds the "udelay_test" module that helps to make sure
2820           that udelay() is working properly.     2435           that udelay() is working properly.
2821                                                  2436 
2822           If unsure, say N.                      2437           If unsure, say N.
2823                                                  2438 
2824 config TEST_STATIC_KEYS                          2439 config TEST_STATIC_KEYS
2825         tristate "Test static keys"              2440         tristate "Test static keys"
2826         depends on m                             2441         depends on m
2827         help                                     2442         help
2828           Test the static key interfaces.        2443           Test the static key interfaces.
2829                                                  2444 
2830           If unsure, say N.                      2445           If unsure, say N.
2831                                                  2446 
2832 config TEST_DYNAMIC_DEBUG                     << 
2833         tristate "Test DYNAMIC_DEBUG"         << 
2834         depends on DYNAMIC_DEBUG              << 
2835         help                                  << 
2836           This module registers a tracer call << 
2837           pr_debugs in a 'do_debugging' funct << 
2838           enablements, calls the function, an << 
2839                                               << 
2840           If unsure, say N.                   << 
2841                                               << 
2842 config TEST_KMOD                                 2447 config TEST_KMOD
2843         tristate "kmod stress tester"            2448         tristate "kmod stress tester"
2844         depends on m                             2449         depends on m
2845         depends on NETDEVICES && NET_CORE &&     2450         depends on NETDEVICES && NET_CORE && INET # for TUN
2846         depends on BLOCK                         2451         depends on BLOCK
2847         depends on PAGE_SIZE_LESS_THAN_256KB  << 
2848         select TEST_LKM                          2452         select TEST_LKM
2849         select XFS_FS                            2453         select XFS_FS
2850         select TUN                               2454         select TUN
2851         select BTRFS_FS                          2455         select BTRFS_FS
2852         help                                     2456         help
2853           Test the kernel's module loading me    2457           Test the kernel's module loading mechanism: kmod. kmod implements
2854           support to load modules using the L    2458           support to load modules using the Linux kernel's usermode helper.
2855           This test provides a series of test    2459           This test provides a series of tests against kmod.
2856                                                  2460 
2857           Although technically you can either    2461           Although technically you can either build test_kmod as a module or
2858           into the kernel we disallow buildin    2462           into the kernel we disallow building it into the kernel since
2859           it stress tests request_module() an    2463           it stress tests request_module() and this will very likely cause
2860           some issues by taking over precious    2464           some issues by taking over precious threads available from other
2861           module load requests, ultimately th    2465           module load requests, ultimately this could be fatal.
2862                                                  2466 
2863           To run tests run:                      2467           To run tests run:
2864                                                  2468 
2865           tools/testing/selftests/kmod/kmod.s    2469           tools/testing/selftests/kmod/kmod.sh --help
2866                                                  2470 
2867           If unsure, say N.                      2471           If unsure, say N.
2868                                                  2472 
2869 config TEST_DEBUG_VIRTUAL                        2473 config TEST_DEBUG_VIRTUAL
2870         tristate "Test CONFIG_DEBUG_VIRTUAL f    2474         tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871         depends on DEBUG_VIRTUAL                 2475         depends on DEBUG_VIRTUAL
2872         help                                     2476         help
2873           Test the kernel's ability to detect    2477           Test the kernel's ability to detect incorrect calls to
2874           virt_to_phys() done against the non    2478           virt_to_phys() done against the non-linear part of the
2875           kernel's virtual address map.          2479           kernel's virtual address map.
2876                                                  2480 
2877           If unsure, say N.                      2481           If unsure, say N.
2878                                                  2482 
2879 config TEST_MEMCAT_P                             2483 config TEST_MEMCAT_P
2880         tristate "Test memcat_p() helper func    2484         tristate "Test memcat_p() helper function"
2881         help                                     2485         help
2882           Test the memcat_p() helper for corr    2486           Test the memcat_p() helper for correctly merging two
2883           pointer arrays together.               2487           pointer arrays together.
2884                                                  2488 
2885           If unsure, say N.                      2489           If unsure, say N.
2886                                                  2490 
                                                   >> 2491 config TEST_LIVEPATCH
                                                   >> 2492         tristate "Test livepatching"
                                                   >> 2493         default n
                                                   >> 2494         depends on DYNAMIC_DEBUG
                                                   >> 2495         depends on LIVEPATCH
                                                   >> 2496         depends on m
                                                   >> 2497         help
                                                   >> 2498           Test kernel livepatching features for correctness.  The tests will
                                                   >> 2499           load test modules that will be livepatched in various scenarios.
                                                   >> 2500 
                                                   >> 2501           To run all the livepatching tests:
                                                   >> 2502 
                                                   >> 2503           make -C tools/testing/selftests TARGETS=livepatch run_tests
                                                   >> 2504 
                                                   >> 2505           Alternatively, individual tests may be invoked:
                                                   >> 2506 
                                                   >> 2507           tools/testing/selftests/livepatch/test-callbacks.sh
                                                   >> 2508           tools/testing/selftests/livepatch/test-livepatch.sh
                                                   >> 2509           tools/testing/selftests/livepatch/test-shadow-vars.sh
                                                   >> 2510 
                                                   >> 2511           If unsure, say N.
                                                   >> 2512 
2887 config TEST_OBJAGG                               2513 config TEST_OBJAGG
2888         tristate "Perform selftest on object     2514         tristate "Perform selftest on object aggreration manager"
2889         default n                                2515         default n
2890         depends on OBJAGG                        2516         depends on OBJAGG
2891         help                                     2517         help
2892           Enable this option to test object a    2518           Enable this option to test object aggregation manager on boot
2893           (or module load).                      2519           (or module load).
2894                                                  2520 
                                                   >> 2521 
                                                   >> 2522 config TEST_STACKINIT
                                                   >> 2523         tristate "Test level of stack variable initialization"
                                                   >> 2524         help
                                                   >> 2525           Test if the kernel is zero-initializing stack variables and
                                                   >> 2526           padding. Coverage is controlled by compiler flags,
                                                   >> 2527           CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
                                                   >> 2528           or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
                                                   >> 2529 
                                                   >> 2530           If unsure, say N.
                                                   >> 2531 
2895 config TEST_MEMINIT                              2532 config TEST_MEMINIT
2896         tristate "Test heap/page initializati    2533         tristate "Test heap/page initialization"
2897         help                                     2534         help
2898           Test if the kernel is zero-initiali    2535           Test if the kernel is zero-initializing heap and page allocations.
2899           This can be useful to test init_on_    2536           This can be useful to test init_on_alloc and init_on_free features.
2900                                                  2537 
2901           If unsure, say N.                      2538           If unsure, say N.
2902                                                  2539 
2903 config TEST_HMM                                  2540 config TEST_HMM
2904         tristate "Test HMM (Heterogeneous Mem    2541         tristate "Test HMM (Heterogeneous Memory Management)"
2905         depends on TRANSPARENT_HUGEPAGE          2542         depends on TRANSPARENT_HUGEPAGE
2906         depends on DEVICE_PRIVATE                2543         depends on DEVICE_PRIVATE
2907         select HMM_MIRROR                        2544         select HMM_MIRROR
2908         select MMU_NOTIFIER                      2545         select MMU_NOTIFIER
2909         help                                     2546         help
2910           This is a pseudo device driver sole    2547           This is a pseudo device driver solely for testing HMM.
2911           Say M here if you want to build the    2548           Say M here if you want to build the HMM test module.
2912           Doing so will allow you to run tool    2549           Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913                                                  2550 
2914           If unsure, say N.                      2551           If unsure, say N.
2915                                                  2552 
2916 config TEST_FREE_PAGES                           2553 config TEST_FREE_PAGES
2917         tristate "Test freeing pages"            2554         tristate "Test freeing pages"
2918         help                                     2555         help
2919           Test that a memory leak does not oc    2556           Test that a memory leak does not occur due to a race between
2920           freeing a block of pages and a spec    2557           freeing a block of pages and a speculative page reference.
2921           Loading this module is safe if your    2558           Loading this module is safe if your kernel has the bug fixed.
2922           If the bug is not fixed, it will le    2559           If the bug is not fixed, it will leak gigabytes of memory and
2923           probably OOM your system.              2560           probably OOM your system.
2924                                                  2561 
2925 config TEST_FPU                                  2562 config TEST_FPU
2926         tristate "Test floating point operati    2563         tristate "Test floating point operations in kernel space"
2927         depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2564         depends on X86 && !KCOV_INSTRUMENT_ALL
2928         help                                     2565         help
2929           Enable this option to add /sys/kern    2566           Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930           which will trigger a sequence of fl    2567           which will trigger a sequence of floating point operations. This is used
2931           for self-testing floating point con    2568           for self-testing floating point control register setting in
2932           kernel_fpu_begin().                    2569           kernel_fpu_begin().
2933                                                  2570 
2934           If unsure, say N.                      2571           If unsure, say N.
2935                                                  2572 
2936 config TEST_CLOCKSOURCE_WATCHDOG              << 
2937         tristate "Test clocksource watchdog i << 
2938         depends on CLOCKSOURCE_WATCHDOG       << 
2939         help                                  << 
2940           Enable this option to create a kern << 
2941           a test of the clocksource watchdog. << 
2942           via modprobe or insmod in which cas << 
2943           loaded, or it may be built in, in w << 
2944           shortly after boot.                 << 
2945                                               << 
2946           If unsure, say N.                   << 
2947                                               << 
2948 config TEST_OBJPOOL                           << 
2949         tristate "Test module for correctness << 
2950         default n                             << 
2951         depends on m && DEBUG_KERNEL          << 
2952         help                                  << 
2953           This builds the "test_objpool" modu << 
2954           correctness verification and concur << 
2955           allocation and reclamation.         << 
2956                                               << 
2957           If unsure, say N.                   << 
2958                                               << 
2959 endif # RUNTIME_TESTING_MENU                     2573 endif # RUNTIME_TESTING_MENU
2960                                                  2574 
2961 config ARCH_USE_MEMTEST                          2575 config ARCH_USE_MEMTEST
2962         bool                                     2576         bool
2963         help                                     2577         help
2964           An architecture should select this     2578           An architecture should select this when it uses early_memtest()
2965           during boot process.                   2579           during boot process.
2966                                                  2580 
2967 config MEMTEST                                   2581 config MEMTEST
2968         bool "Memtest"                           2582         bool "Memtest"
2969         depends on ARCH_USE_MEMTEST              2583         depends on ARCH_USE_MEMTEST
2970         help                                     2584         help
2971           This option adds a kernel parameter    2585           This option adds a kernel parameter 'memtest', which allows memtest
2972           to be set and executed.                2586           to be set and executed.
2973                 memtest=0, mean disabled; --     2587                 memtest=0, mean disabled; -- default
2974                 memtest=1, mean do 1 test pat    2588                 memtest=1, mean do 1 test pattern;
2975                 ...                              2589                 ...
2976                 memtest=17, mean do 17 test p    2590                 memtest=17, mean do 17 test patterns.
2977           If you are unsure how to answer thi    2591           If you are unsure how to answer this question, answer N.
2978                                                  2592 
2979                                                  2593 
2980                                                  2594 
2981 config HYPERV_TESTING                            2595 config HYPERV_TESTING
2982         bool "Microsoft Hyper-V driver testin    2596         bool "Microsoft Hyper-V driver testing"
2983         default n                                2597         default n
2984         depends on HYPERV && DEBUG_FS            2598         depends on HYPERV && DEBUG_FS
2985         help                                     2599         help
2986           Select this option to enable Hyper-    2600           Select this option to enable Hyper-V vmbus testing.
2987                                                  2601 
2988 endmenu # "Kernel Testing and Coverage"          2602 endmenu # "Kernel Testing and Coverage"
2989                                                  2603 
2990 menu "Rust hacking"                           !! 2604 source "Documentation/Kconfig"
2991                                               << 
2992 config RUST_DEBUG_ASSERTIONS                  << 
2993         bool "Debug assertions"               << 
2994         depends on RUST                       << 
2995         help                                  << 
2996           Enables rustc's `-Cdebug-assertions << 
2997                                               << 
2998           This flag lets you turn `cfg(debug_ << 
2999           compilation on or off. This can be  << 
3000           code in development but not in prod << 
3001           the behavior of the standard librar << 
3002                                               << 
3003           Note that this will apply to all Ru << 
3004                                               << 
3005           If unsure, say N.                   << 
3006                                               << 
3007 config RUST_OVERFLOW_CHECKS                   << 
3008         bool "Overflow checks"                << 
3009         default y                             << 
3010         depends on RUST                       << 
3011         help                                  << 
3012           Enables rustc's `-Coverflow-checks` << 
3013                                               << 
3014           This flag allows you to control the << 
3015           overflow. When overflow-checks are  << 
3016           on overflow.                        << 
3017                                               << 
3018           Note that this will apply to all Ru << 
3019                                               << 
3020           If unsure, say Y.                   << 
3021                                               << 
3022 config RUST_BUILD_ASSERT_ALLOW                << 
3023         bool "Allow unoptimized build-time as << 
3024         depends on RUST                       << 
3025         help                                  << 
3026           Controls how are `build_error!` and << 
3027                                               << 
3028           If calls to them exist in the binar << 
3029           or that the optimizer failed to ver << 
3030                                               << 
3031           This should not happen, thus by def << 
3032           as an escape hatch, you can choose  << 
3033           and let the check be carried at run << 
3034           the check fails).                   << 
3035                                               << 
3036           If unsure, say N.                   << 
3037                                               << 
3038 config RUST_KERNEL_DOCTESTS                   << 
3039         bool "Doctests for the `kernel` crate << 
3040         depends on RUST && KUNIT=y            << 
3041         default KUNIT_ALL_TESTS               << 
3042         help                                  << 
3043           This builds the documentation tests << 
3044           as KUnit tests.                     << 
3045                                               << 
3046           For more information on KUnit and u << 
3047           please refer to the KUnit documenta << 
3048                                               << 
3049           If unsure, say N.                   << 
3050                                               << 
3051 endmenu # "Rust"                              << 
3052                                                  2605 
3053 endmenu # Kernel hacking                         2606 endmenu # Kernel hacking
                                                      

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