1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 menu "Kernel hacking" 2 menu "Kernel hacking"
3 3
4 menu "printk and dmesg options" 4 menu "printk and dmesg options"
5 5
6 config PRINTK_TIME 6 config PRINTK_TIME
7 bool "Show timing information on print 7 bool "Show timing information on printks"
8 depends on PRINTK 8 depends on PRINTK
9 help 9 help
10 Selecting this option causes time st 10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output o 11 messages to be added to the output of the syslog() system
12 call and at the console. 12 call and at the console.
13 13
14 The timestamp is always recorded int 14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifi 15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp 16 be included, not that the timestamp is recorded.
17 17
18 The behavior is also controlled by t 18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documen 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
20 20
21 config PRINTK_CALLER 21 config PRINTK_CALLER
22 bool "Show caller information on print 22 bool "Show caller information on printks"
23 depends on PRINTK 23 depends on PRINTK
24 help 24 help
25 Selecting this option causes printk( 25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "proces 26 in task context) or a caller "processor id" (if not in task context)
27 to every message. 27 to every message.
28 28
29 This option is intended for environm 29 This option is intended for environments where multiple threads
30 concurrently call printk() for many 30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where thes 31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple 32 line which was divided into multiple lines due to race) came from.
33 33
34 Since toggling after boot makes the 34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the k 35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface. 36 sysfs interface.
37 37
38 config STACKTRACE_BUILD_ID 38 config STACKTRACE_BUILD_ID
39 bool "Show build ID information in sta 39 bool "Show build ID information in stacktraces"
40 depends on PRINTK 40 depends on PRINTK
41 help 41 help
42 Selecting this option adds build ID 42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk 43 stacktraces printed with the printk format '%p[SR]b'.
44 44
45 This option is intended for distros 45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded giv 46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is 47 kernel module where the function is located.
48 48
49 config CONSOLE_LOGLEVEL_DEFAULT 49 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)" 50 int "Default console loglevel (1-15)"
51 range 1 15 51 range 1 15
52 default "7" 52 default "7"
53 help 53 help
54 Default loglevel to determine what w 54 Default loglevel to determine what will be printed on the console.
55 55
56 Setting a default here is equivalent 56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> co 57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well. 58 value is specified here as well.
59 59
60 Note: This does not affect the log l 60 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is control 61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option. 62 option.
63 63
64 config CONSOLE_LOGLEVEL_QUIET 64 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)" 65 int "quiet console loglevel (1-15)"
66 range 1 15 66 range 1 15
67 default "4" 67 default "4"
68 help 68 help
69 loglevel to use when "quiet" is pass 69 loglevel to use when "quiet" is passed on the kernel commandline.
70 70
71 When "quiet" is passed on the kernel 71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW pa 72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CON 73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74 74
75 config MESSAGE_LOGLEVEL_DEFAULT 75 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)" 76 int "Default message log level (1-7)"
77 range 1 7 77 range 1 7
78 default "4" 78 default "4"
79 help 79 help
80 Default log level for printk stateme 80 Default log level for printk statements with no specified priority.
81 81
82 This was hard-coded to KERN_WARNING 82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely 83 that are auditing their logs closely may want to set it to a lower
84 priority. 84 priority.
85 85
86 Note: This does not affect what mess 86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use logl 87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL 88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89 89
90 config BOOT_PRINTK_DELAY 90 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message b 91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && G 92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help 93 help
94 This build option allows you to read 94 This build option allows you to read kernel boot messages
95 by inserting a short delay after eac 95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the ker 96 specified in milliseconds on the kernel command line,
97 using "boot_delay=N". 97 using "boot_delay=N".
98 98
99 It is likely that you would also nee 99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value. 100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj 101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before 102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adverse 103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the firs 104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOC 105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup condit 106 what it believes to be lockup conditions.
107 107
108 config DYNAMIC_DEBUG 108 config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support" 109 bool "Enable dynamic printk() support"
110 default n 110 default n
111 depends on PRINTK 111 depends on PRINTK
112 depends on (DEBUG_FS || PROC_FS) 112 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE 113 select DYNAMIC_DEBUG_CORE
114 help 114 help
115 115
116 Compiles debug level messages into t 116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 121 enlarges the kernel text size by about 2%.
122 122
123 If a source file is compiled with DE 123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 126 turned on by many CONFIG_*DEBUG* options.
127 127
128 Usage: 128 Usage:
129 129
130 Dynamic debugging is controlled via 130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' 131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesyst 132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature. 133 making use of this feature.
134 We refer the control file as: <debug 134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 136 format for each line of the file is:
137 137
138 filename:lineno [module]functi 138 filename:lineno [module]function flags format
139 139
140 filename : source file of the debug 140 filename : source file of the debug statement
141 lineno : line number of the debug st 141 lineno : line number of the debug statement
142 module : module that contains the de 142 module : module that contains the debug statement
143 function : function that contains th 143 function : function that contains the debug statement
144 flags : '=p' means the line is turne 144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb 145 format : the format used for the debug statement
146 146
147 From a live system: 147 From a live system:
148 148
149 nullarbor:~ # cat <debugfs>/dy 149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 154
155 Example usage: 155 Example usage:
156 156
157 // enable the message at line 157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 159 <debugfs>/dynamic_debug/control
160 160
161 // enable all the messages in 161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 163 <debugfs>/dynamic_debug/control
164 164
165 // enable all the messages in 165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 166 nullarbor:~ # echo -n 'module nfsd +p' >
167 167 <debugfs>/dynamic_debug/control
168 168
169 // enable all 12 messages in t 169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 170 nullarbor:~ # echo -n 'func svc_process +p' >
171 171 <debugfs>/dynamic_debug/control
172 172
173 // disable all 12 messages in 173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 174 nullarbor:~ # echo -n 'func svc_process -p' >
175 175 <debugfs>/dynamic_debug/control
176 176
177 See Documentation/admin-guide/dynami 177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 178 information.
179 179
180 config DYNAMIC_DEBUG_CORE 180 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic 181 bool "Enable core function of dynamic debug support"
182 depends on PRINTK 182 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS) 183 depends on (DEBUG_FS || PROC_FS)
184 help 184 help
185 Enable core functional support of dy 185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug t 186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for eac 187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where th 188 the case of embedded system where the kernel image size is
189 sensitive for people. 189 sensitive for people.
190 190
191 config SYMBOLIC_ERRNAME 191 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in 192 bool "Support symbolic error names in printf"
193 default y if PRINTK 193 default y if PRINTK
194 help 194 help
195 If you say Y here, the kernel's prin 195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error name 196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kerne 197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel 198 (about 3KB), but can make the kernel logs easier to read.
199 199
200 config DEBUG_BUGVERBOSE 200 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70 201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE 202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y 203 default y
204 help 204 help
205 Say Y here to make BUG() panics outp 205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP a 206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of 207 debugging but costs about 70-100K of memory.
208 208
209 endmenu # "printk and dmesg options" 209 endmenu # "printk and dmesg options"
210 210
211 config DEBUG_KERNEL 211 config DEBUG_KERNEL
212 bool "Kernel debugging" 212 bool "Kernel debugging"
213 help 213 help
214 Say Y here if you are developing dri 214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems. 215 identify kernel problems.
216 216
217 config DEBUG_MISC 217 config DEBUG_MISC
218 bool "Miscellaneous debug code" 218 bool "Miscellaneous debug code"
219 default DEBUG_KERNEL 219 default DEBUG_KERNEL
220 depends on DEBUG_KERNEL 220 depends on DEBUG_KERNEL
221 help 221 help
222 Say Y here if you need to enable mis 222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug optio 223 be under a more specific debug option but isn't.
224 224
225 menu "Compile-time checks and compiler options 225 menu "Compile-time checks and compiler options"
226 226
227 config DEBUG_INFO 227 config DEBUG_INFO
228 bool 228 bool
229 help 229 help
230 A kernel debug info option other tha 230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice be 231 in the "Debug information" choice below, indicating that debug
232 information will be generated for bu 232 information will be generated for build targets.
233 233
234 # Clang generates .uleb128 with label differen !! 234 # Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
235 # older binutils ports do not support when uti !! 235 # some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
236 # relaxation: https://sourceware.org/bugzilla/ !! 236 config AS_HAS_NON_CONST_LEB128
237 config AS_HAS_NON_CONST_ULEB128 <<
238 def_bool $(as-instr,.uleb128 .Lexpr_en 237 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
239 238
240 choice 239 choice
241 prompt "Debug information" 240 prompt "Debug information"
242 depends on DEBUG_KERNEL 241 depends on DEBUG_KERNEL
243 help 242 help
244 Selecting something other than "None 243 Selecting something other than "None" results in a kernel image
245 that will include debugging info res 244 that will include debugging info resulting in a larger kernel image.
246 This adds debug symbols to the kerne 245 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 246 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 247 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
249 248
250 Choose which version of DWARF debug 249 Choose which version of DWARF debug info to emit. If unsure,
251 select "Toolchain default". 250 select "Toolchain default".
252 251
253 config DEBUG_INFO_NONE 252 config DEBUG_INFO_NONE
254 bool "Disable debug information" 253 bool "Disable debug information"
255 help 254 help
256 Do not build the kernel with debuggi 255 Do not build the kernel with debugging information, which will
257 result in a faster and smaller build 256 result in a faster and smaller build.
258 257
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT 258 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
260 bool "Rely on the toolchain's implicit 259 bool "Rely on the toolchain's implicit default DWARF version"
261 select DEBUG_INFO 260 select DEBUG_INFO
262 depends on !CC_IS_CLANG || AS_IS_LLVM !! 261 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
263 help 262 help
264 The implicit default version of DWAR 263 The implicit default version of DWARF debug info produced by a
265 toolchain changes over time. 264 toolchain changes over time.
266 265
267 This can break consumers of the debu 266 This can break consumers of the debug info that haven't upgraded to
268 support newer revisions, and prevent 267 support newer revisions, and prevent testing newer versions, but
269 those should be less common scenario 268 those should be less common scenarios.
270 269
271 config DEBUG_INFO_DWARF4 270 config DEBUG_INFO_DWARF4
272 bool "Generate DWARF Version 4 debugin 271 bool "Generate DWARF Version 4 debuginfo"
273 select DEBUG_INFO 272 select DEBUG_INFO
274 depends on !CC_IS_CLANG || AS_IS_LLVM 273 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
275 help 274 help
276 Generate DWARF v4 debug info. This r 275 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
277 if using clang without clang's integ 276 if using clang without clang's integrated assembler, and gdb 7.0+.
278 277
279 If you have consumers of DWARF debug 278 If you have consumers of DWARF debug info that are not ready for
280 newer revisions of DWARF, you may wi 279 newer revisions of DWARF, you may wish to choose this or have your
281 config select this. 280 config select this.
282 281
283 config DEBUG_INFO_DWARF5 282 config DEBUG_INFO_DWARF5
284 bool "Generate DWARF Version 5 debugin 283 bool "Generate DWARF Version 5 debuginfo"
285 select DEBUG_INFO 284 select DEBUG_INFO
286 depends on !ARCH_HAS_BROKEN_DWARF5 !! 285 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
287 depends on !CC_IS_CLANG || AS_IS_LLVM <<
288 help 286 help
289 Generate DWARF v5 debug info. Requir 287 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
290 5.0+ accepts the -gdwarf-5 flag but 288 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
291 draft features until 7.0), and gdb 8 289 draft features until 7.0), and gdb 8.0+.
292 290
293 Changes to the structure of debug in 291 Changes to the structure of debug info in Version 5 allow for around
294 15-18% savings in resulting image an 292 15-18% savings in resulting image and debug info section sizes as
295 compared to DWARF Version 4. DWARF V 293 compared to DWARF Version 4. DWARF Version 5 standardizes previous
296 extensions such as accelerators for 294 extensions such as accelerators for symbol indexing and the format
297 for fission (.dwo/.dwp) files. Users 295 for fission (.dwo/.dwp) files. Users may not want to select this
298 config if they rely on tooling that 296 config if they rely on tooling that has not yet been updated to
299 support DWARF Version 5. 297 support DWARF Version 5.
300 298
301 endchoice # "Debug information" 299 endchoice # "Debug information"
302 300
303 if DEBUG_INFO 301 if DEBUG_INFO
304 302
305 config DEBUG_INFO_REDUCED 303 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 304 bool "Reduce debugging information"
307 help 305 help
308 If you say Y here gcc is instructed 306 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 307 information for structure types. This means that tools that
310 need full debugging information (lik 308 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 309 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 310 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 311 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 312 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 313 Only works with newer gcc versions.
316 314
317 choice 315 choice
318 prompt "Compressed Debug information" 316 prompt "Compressed Debug information"
319 help 317 help
320 Compress the resulting debug info. R 318 Compress the resulting debug info. Results in smaller debug info sections,
321 but requires that consumers are able 319 but requires that consumers are able to decompress the results.
322 320
323 If unsure, choose DEBUG_INFO_COMPRES 321 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
324 322
325 config DEBUG_INFO_COMPRESSED_NONE 323 config DEBUG_INFO_COMPRESSED_NONE
326 bool "Don't compress debug information 324 bool "Don't compress debug information"
327 help 325 help
328 Don't compress debug info sections. 326 Don't compress debug info sections.
329 327
330 config DEBUG_INFO_COMPRESSED_ZLIB 328 config DEBUG_INFO_COMPRESSED_ZLIB
331 bool "Compress debugging information w 329 bool "Compress debugging information with zlib"
332 depends on $(cc-option,-gz=zlib) 330 depends on $(cc-option,-gz=zlib)
333 depends on $(ld-option,--compress-debu 331 depends on $(ld-option,--compress-debug-sections=zlib)
334 help 332 help
335 Compress the debug information using 333 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
336 5.0+, binutils 2.26+, and zlib. 334 5.0+, binutils 2.26+, and zlib.
337 335
338 Users of dpkg-deb via scripts/packag 336 Users of dpkg-deb via scripts/package/builddeb may find an increase in
339 size of their debug .deb packages wi 337 size of their debug .deb packages with this config set, due to the
340 debug info being compressed with zli 338 debug info being compressed with zlib, then the object files being
341 recompressed with a different compre 339 recompressed with a different compression scheme. But this is still
342 preferable to setting $KDEB_COMPRESS 340 preferable to setting $KDEB_COMPRESS to "none" which would be even
343 larger. 341 larger.
344 342
345 config DEBUG_INFO_COMPRESSED_ZSTD 343 config DEBUG_INFO_COMPRESSED_ZSTD
346 bool "Compress debugging information w 344 bool "Compress debugging information with zstd"
347 depends on $(cc-option,-gz=zstd) 345 depends on $(cc-option,-gz=zstd)
348 depends on $(ld-option,--compress-debu 346 depends on $(ld-option,--compress-debug-sections=zstd)
349 help 347 help
350 Compress the debug information using 348 Compress the debug information using zstd. This may provide better
351 compression than zlib, for about the 349 compression than zlib, for about the same time costs, but requires newer
352 toolchain support. Requires GCC 13. 350 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
353 zstd. 351 zstd.
354 352
355 endchoice # "Compressed Debug information" 353 endchoice # "Compressed Debug information"
356 354
357 config DEBUG_INFO_SPLIT 355 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 356 bool "Produce split debuginfo in .dwo files"
359 depends on $(cc-option,-gsplit-dwarf) 357 depends on $(cc-option,-gsplit-dwarf)
360 # RISC-V linker relaxation + -gsplit-d 358 # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
361 # prior to 12.x: 359 # prior to 12.x:
362 # https://github.com/llvm/llvm-project 360 # https://github.com/llvm/llvm-project/issues/56642
363 # https://gcc.gnu.org/bugzilla/show_bu 361 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
364 depends on !RISCV || GCC_VERSION >= 12 362 depends on !RISCV || GCC_VERSION >= 120000
365 help 363 help
366 Generate debug info into separate .d 364 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 365 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 366 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 367 files instead of multiple times in object files and executables.
370 In addition the debug information is 368 In addition the debug information is also compressed.
371 369
372 Requires recent gcc (4.7+) and recen 370 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 371 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 372 to know about the .dwo files and include them.
375 Incompatible with older versions of 373 Incompatible with older versions of ccache.
376 374
377 config DEBUG_INFO_BTF 375 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" 376 bool "Generate BTF type information"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG 377 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || C 378 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
381 depends on BPF_SYSCALL 379 depends on BPF_SYSCALL
382 depends on !DEBUG_INFO_DWARF5 || PAHOL 380 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
383 # pahole uses elfutils, which does not <<
384 depends on !HEXAGON <<
385 help 381 help
386 Generate deduplicated BTF type infor 382 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 383 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 384 DWARF type info into equivalent deduplicated BTF type info.
389 385
390 config PAHOLE_HAS_SPLIT_BTF 386 config PAHOLE_HAS_SPLIT_BTF
391 def_bool PAHOLE_VERSION >= 119 387 def_bool PAHOLE_VERSION >= 119
392 388
393 config PAHOLE_HAS_BTF_TAG 389 config PAHOLE_HAS_BTF_TAG
394 def_bool PAHOLE_VERSION >= 123 390 def_bool PAHOLE_VERSION >= 123
395 depends on CC_IS_CLANG 391 depends on CC_IS_CLANG
396 help 392 help
397 Decide whether pahole emits btf_tag 393 Decide whether pahole emits btf_tag attributes (btf_type_tag and
398 btf_decl_tag) or not. Currently only 394 btf_decl_tag) or not. Currently only clang compiler implements
399 these attributes, so make the config 395 these attributes, so make the config depend on CC_IS_CLANG.
400 396
401 config PAHOLE_HAS_LANG_EXCLUDE 397 config PAHOLE_HAS_LANG_EXCLUDE
402 def_bool PAHOLE_VERSION >= 124 398 def_bool PAHOLE_VERSION >= 124
403 help 399 help
404 Support for the --lang_exclude flag 400 Support for the --lang_exclude flag which makes pahole exclude
405 compilation units from the supplied 401 compilation units from the supplied language. Used in Kbuild to
406 omit Rust CUs which are not supporte 402 omit Rust CUs which are not supported in version 1.24 of pahole,
407 otherwise it would emit malformed ke 403 otherwise it would emit malformed kernel and module binaries when
408 using DEBUG_INFO_BTF_MODULES. 404 using DEBUG_INFO_BTF_MODULES.
409 405
410 config DEBUG_INFO_BTF_MODULES 406 config DEBUG_INFO_BTF_MODULES
411 bool "Generate BTF type information fo 407 bool "Generate BTF type information for kernel modules"
412 default y 408 default y
413 depends on DEBUG_INFO_BTF && MODULES & 409 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
414 help 410 help
415 Generate compact split BTF type info 411 Generate compact split BTF type information for kernel modules.
416 412
417 config MODULE_ALLOW_BTF_MISMATCH 413 config MODULE_ALLOW_BTF_MISMATCH
418 bool "Allow loading modules with non-m 414 bool "Allow loading modules with non-matching BTF type info"
419 depends on DEBUG_INFO_BTF_MODULES 415 depends on DEBUG_INFO_BTF_MODULES
420 help 416 help
421 For modules whose split BTF does not 417 For modules whose split BTF does not match vmlinux, load without
422 BTF rather than refusing to load. Th 418 BTF rather than refusing to load. The default behavior with
423 module BTF enabled is to reject modu 419 module BTF enabled is to reject modules with such mismatches;
424 this option will still load module B 420 this option will still load module BTF where possible but ignore
425 it when a mismatch is found. 421 it when a mismatch is found.
426 422
427 config GDB_SCRIPTS 423 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 424 bool "Provide GDB scripts for kernel debugging"
429 help 425 help
430 This creates the required links to G 426 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 427 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 428 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 429 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 430 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 431 for further details.
436 432
437 endif # DEBUG_INFO 433 endif # DEBUG_INFO
438 434
439 config FRAME_WARN 435 config FRAME_WARN
440 int "Warn for stack frames larger than 436 int "Warn for stack frames larger than"
441 range 0 8192 437 range 0 8192
442 default 0 if KMSAN 438 default 0 if KMSAN
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 439 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC 440 default 2048 if PARISC
445 default 1536 if (!64BIT && XTENSA) 441 default 1536 if (!64BIT && XTENSA)
446 default 1280 if KASAN && !64BIT 442 default 1280 if KASAN && !64BIT
447 default 1024 if !64BIT 443 default 1024 if !64BIT
448 default 2048 if 64BIT 444 default 2048 if 64BIT
449 help 445 help
450 Tell the compiler to warn at build t 446 Tell the compiler to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 447 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 448 Setting it to 0 disables the warning.
453 449
454 config STRIP_ASM_SYMS 450 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 451 bool "Strip assembler-generated symbols during link"
456 default n 452 default n
457 help 453 help
458 Strip internal assembler-generated s 454 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 455 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 456 get_wchan() and suchlike.
461 457
462 config READABLE_ASM 458 config READABLE_ASM
463 bool "Generate readable assembler code 459 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 460 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC 461 depends on CC_IS_GCC
466 help 462 help
467 Disable some compiler optimizations 463 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 464 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 465 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 466 sane.
471 467
472 config HEADERS_INSTALL 468 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 469 bool "Install uapi headers to usr/include"
474 depends on !UML 470 depends on !UML
475 help 471 help
476 This option will install uapi header 472 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 473 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 474 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 475 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 476 as uapi header sanity checks.
481 477
482 config DEBUG_SECTION_MISMATCH 478 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 479 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC 480 depends on CC_IS_GCC
485 help 481 help
486 The section mismatch analysis checks 482 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 483 references from one section to another section.
488 During linktime or runtime, some sec 484 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 485 any use of code/data previously in these sections would
490 most likely result in an oops. 486 most likely result in an oops.
491 In the code, functions and variables 487 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 488 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 489 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 490 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 491 kernel build, and enabling this option causes the following
496 additional step to occur: 492 additional step to occur:
497 - Add the option -fno-inline-functio 493 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 494 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 495 function, we would lose the section information and thus
500 the analysis would not catch the i 496 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 497 This option tells gcc to inline less (but it does result in
502 a larger kernel). 498 a larger kernel).
503 499
504 config SECTION_MISMATCH_WARN_ONLY 500 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 501 bool "Make section mismatch errors non-fatal"
506 default y 502 default y
507 help 503 help
508 If you say N here, the build process 504 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 505 section mismatch, instead of just throwing warnings.
510 506
511 If unsure, say Y. 507 If unsure, say Y.
512 508
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B 509 config DEBUG_FORCE_FUNCTION_ALIGN_64B
514 bool "Force all function address 64B a 510 bool "Force all function address 64B aligned"
515 depends on EXPERT && (X86_64 || ARM64 511 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
516 select FUNCTION_ALIGNMENT_64B 512 select FUNCTION_ALIGNMENT_64B
517 help 513 help
518 There are cases that a commit from o 514 There are cases that a commit from one domain changes the function
519 address alignment of other domains, 515 address alignment of other domains, and cause magic performance
520 bump (regression or improvement). En 516 bump (regression or improvement). Enable this option will help to
521 verify if the bump is caused by func 517 verify if the bump is caused by function alignment changes, while
522 it will slightly increase the kernel 518 it will slightly increase the kernel size and affect icache usage.
523 519
524 It is mainly for debug and performan 520 It is mainly for debug and performance tuning use.
525 521
526 # 522 #
527 # Select this config option from the architect 523 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 524 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 525 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 526 #
531 config ARCH_WANT_FRAME_POINTERS 527 config ARCH_WANT_FRAME_POINTERS
532 bool 528 bool
533 529
534 config FRAME_POINTER 530 config FRAME_POINTER
535 bool "Compile the kernel with frame po 531 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 532 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 533 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 534 help
539 If you say Y here the resulting kern 535 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 536 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 537 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 538
543 config OBJTOOL 539 config OBJTOOL
544 bool 540 bool
545 541
546 config STACK_VALIDATION 542 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 543 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN 544 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
549 select OBJTOOL 545 select OBJTOOL
550 default n 546 default n
551 help 547 help
552 Validate frame pointer rules at comp 548 Validate frame pointer rules at compile-time. This helps ensure that
553 runtime stack traces are more reliab 549 runtime stack traces are more reliable.
554 550
555 For more information, see 551 For more information, see
556 tools/objtool/Documentation/objtool. 552 tools/objtool/Documentation/objtool.txt.
557 553
558 config NOINSTR_VALIDATION 554 config NOINSTR_VALIDATION
559 bool 555 bool
560 depends on HAVE_NOINSTR_VALIDATION && 556 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
561 select OBJTOOL 557 select OBJTOOL
562 default y 558 default y
563 559
564 config VMLINUX_MAP 560 config VMLINUX_MAP
565 bool "Generate vmlinux.map file when l 561 bool "Generate vmlinux.map file when linking"
566 depends on EXPERT 562 depends on EXPERT
567 help 563 help
568 Selecting this option will pass "-Ma 564 Selecting this option will pass "-Map=vmlinux.map" to ld
569 when linking vmlinux. That file can 565 when linking vmlinux. That file can be useful for verifying
570 and debugging magic section games, a 566 and debugging magic section games, and for seeing which
571 pieces of code get eliminated with 567 pieces of code get eliminated with
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION 568 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
573 569
574 config DEBUG_FORCE_WEAK_PER_CPU 570 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 571 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 572 depends on DEBUG_KERNEL
577 help 573 help
578 s390 and alpha require percpu variab 574 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 575 defined weak to work around addressing range issue which
580 puts the following two restrictions 576 puts the following two restrictions on percpu variable
581 definitions. 577 definitions.
582 578
583 1. percpu symbols must be unique whe 579 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 580 2. percpu variables can't be defined inside a function
585 581
586 To ensure that generic code follows 582 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 583 option forces all percpu variables to be defined as weak.
588 584
589 endmenu # "Compiler options" 585 endmenu # "Compiler options"
590 586
591 menu "Generic Kernel Debugging Instruments" 587 menu "Generic Kernel Debugging Instruments"
592 588
593 config MAGIC_SYSRQ 589 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 590 bool "Magic SysRq key"
595 depends on !UML 591 depends on !UML
596 help 592 help
597 If you say Y here, you will have som 593 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 594 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 595 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 596 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 597 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 598 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 599 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 600 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 601 Don't say Y unless you really know what this hack does.
606 602
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 603 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 604 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 605 depends on MAGIC_SYSRQ
610 default 0x1 606 default 0x1
611 help 607 help
612 Specifies which SysRq key functions 608 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 609 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 610 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 611
616 config MAGIC_SYSRQ_SERIAL 612 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 613 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 614 depends on MAGIC_SYSRQ
619 default y 615 default y
620 help 616 help
621 Many embedded boards have a disconne 617 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 618 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 619 This option allows you to decide whether you want to enable the
624 magic SysRq key. 620 magic SysRq key.
625 621
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE 622 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627 string "Char sequence that enables mag 623 string "Char sequence that enables magic SysRq over serial"
628 depends on MAGIC_SYSRQ_SERIAL 624 depends on MAGIC_SYSRQ_SERIAL
629 default "" 625 default ""
630 help 626 help
631 Specifies a sequence of characters t 627 Specifies a sequence of characters that can follow BREAK to enable
632 SysRq on a serial console. 628 SysRq on a serial console.
633 629
634 If unsure, leave an empty string and 630 If unsure, leave an empty string and the option will not be enabled.
635 631
636 config DEBUG_FS 632 config DEBUG_FS
637 bool "Debug Filesystem" 633 bool "Debug Filesystem"
638 help 634 help
639 debugfs is a virtual file system tha 635 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 636 debugging files into. Enable this option to be able to read and
641 write to these files. 637 write to these files.
642 638
643 For detailed documentation on the de 639 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 640 Documentation/filesystems/.
645 641
646 If unsure, say N. 642 If unsure, say N.
647 643
648 choice 644 choice
649 prompt "Debugfs default access" 645 prompt "Debugfs default access"
650 depends on DEBUG_FS 646 depends on DEBUG_FS
651 default DEBUG_FS_ALLOW_ALL 647 default DEBUG_FS_ALLOW_ALL
652 help 648 help
653 This selects the default access rest 649 This selects the default access restrictions for debugfs.
654 It can be overridden with kernel com 650 It can be overridden with kernel command line option
655 debugfs=[on,no-mount,off]. The restr 651 debugfs=[on,no-mount,off]. The restrictions apply for API access
656 and filesystem registration. 652 and filesystem registration.
657 653
658 config DEBUG_FS_ALLOW_ALL 654 config DEBUG_FS_ALLOW_ALL
659 bool "Access normal" 655 bool "Access normal"
660 help 656 help
661 No restrictions apply. Both API and 657 No restrictions apply. Both API and filesystem registration
662 is on. This is the normal default op 658 is on. This is the normal default operation.
663 659
664 config DEBUG_FS_DISALLOW_MOUNT 660 config DEBUG_FS_DISALLOW_MOUNT
665 bool "Do not register debugfs as files 661 bool "Do not register debugfs as filesystem"
666 help 662 help
667 The API is open but filesystem is no 663 The API is open but filesystem is not loaded. Clients can still do
668 their work and read with debug tools 664 their work and read with debug tools that do not need
669 debugfs filesystem. 665 debugfs filesystem.
670 666
671 config DEBUG_FS_ALLOW_NONE 667 config DEBUG_FS_ALLOW_NONE
672 bool "No access" 668 bool "No access"
673 help 669 help
674 Access is off. Clients get -PERM whe 670 Access is off. Clients get -PERM when trying to create nodes in
675 debugfs tree and debugfs is not regi 671 debugfs tree and debugfs is not registered as a filesystem.
676 Client can then back-off or continue 672 Client can then back-off or continue without debugfs access.
677 673
678 endchoice 674 endchoice
679 675
680 source "lib/Kconfig.kgdb" 676 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan" 677 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" 678 source "lib/Kconfig.kcsan"
683 679
684 endmenu 680 endmenu
685 681
686 menu "Networking Debugging" 682 menu "Networking Debugging"
687 683
688 source "net/Kconfig.debug" 684 source "net/Kconfig.debug"
689 685
690 endmenu # "Networking Debugging" 686 endmenu # "Networking Debugging"
691 687
692 menu "Memory Debugging" 688 menu "Memory Debugging"
693 689
694 source "mm/Kconfig.debug" 690 source "mm/Kconfig.debug"
695 691
696 config DEBUG_OBJECTS 692 config DEBUG_OBJECTS
697 bool "Debug object operations" 693 bool "Debug object operations"
698 depends on DEBUG_KERNEL 694 depends on DEBUG_KERNEL
699 help 695 help
700 If you say Y here, additional code w 696 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 697 kernel to track the life time of various objects and validate
702 the operations on those objects. 698 the operations on those objects.
703 699
704 config DEBUG_OBJECTS_SELFTEST 700 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 701 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 702 depends on DEBUG_OBJECTS
707 help 703 help
708 This enables the selftest of the obj 704 This enables the selftest of the object debug code.
709 705
710 config DEBUG_OBJECTS_FREE 706 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 707 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 708 depends on DEBUG_OBJECTS
713 help 709 help
714 This enables checks whether a k/v fr 710 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 711 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 712 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 713 much slower.
718 714
719 config DEBUG_OBJECTS_TIMERS 715 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 716 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 717 depends on DEBUG_OBJECTS
722 help 718 help
723 If you say Y here, additional code w 719 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 720 timer routines to track the life time of timer objects and
725 validate the timer operations. 721 validate the timer operations.
726 722
727 config DEBUG_OBJECTS_WORK 723 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 724 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 725 depends on DEBUG_OBJECTS
730 help 726 help
731 If you say Y here, additional code w 727 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 728 work queue routines to track the life time of work objects and
733 validate the work operations. 729 validate the work operations.
734 730
735 config DEBUG_OBJECTS_RCU_HEAD 731 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 732 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 733 depends on DEBUG_OBJECTS
738 help 734 help
739 Enable this to turn on debugging of 735 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 736
741 config DEBUG_OBJECTS_PERCPU_COUNTER 737 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 738 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 739 depends on DEBUG_OBJECTS
744 help 740 help
745 If you say Y here, additional code w 741 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 742 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 743 objects and validate the percpu counter operations.
748 744
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 745 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 746 int "debug_objects bootup default value (0-1)"
751 range 0 1 747 range 0 1
752 default "1" 748 default "1"
753 depends on DEBUG_OBJECTS 749 depends on DEBUG_OBJECTS
754 help 750 help
755 Debug objects boot parameter default 751 Debug objects boot parameter default value
756 752
757 config SHRINKER_DEBUG 753 config SHRINKER_DEBUG
758 bool "Enable shrinker debugging suppor 754 bool "Enable shrinker debugging support"
759 depends on DEBUG_FS 755 depends on DEBUG_FS
760 help 756 help
761 Say Y to enable the shrinker debugfs 757 Say Y to enable the shrinker debugfs interface which provides
762 visibility into the kernel memory sh 758 visibility into the kernel memory shrinkers subsystem.
763 Disable it to avoid an extra memory 759 Disable it to avoid an extra memory footprint.
764 760
765 config DEBUG_STACK_USAGE 761 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 762 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 763 depends on DEBUG_KERNEL && !IA64
768 help 764 help
769 Enables the display of the minimum a 765 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 766 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 <<
773 767
774 This option will slow down process c 768 This option will slow down process creation somewhat.
775 769
776 config SCHED_STACK_END_CHECK 770 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 771 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 772 depends on DEBUG_KERNEL
779 default n 773 default n
780 help 774 help
781 This option checks for a stack overr 775 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 776 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 777 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 778 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 779 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 780 is examined. The runtime overhead introduced is minimal.
787 781
788 config ARCH_HAS_DEBUG_VM_PGTABLE 782 config ARCH_HAS_DEBUG_VM_PGTABLE
789 bool 783 bool
790 help 784 help
791 An architecture should select this w 785 An architecture should select this when it can successfully
792 build and run DEBUG_VM_PGTABLE. 786 build and run DEBUG_VM_PGTABLE.
793 787
794 config DEBUG_VM_IRQSOFF 788 config DEBUG_VM_IRQSOFF
795 def_bool DEBUG_VM && !PREEMPT_RT 789 def_bool DEBUG_VM && !PREEMPT_RT
796 790
797 config DEBUG_VM 791 config DEBUG_VM
798 bool "Debug VM" 792 bool "Debug VM"
799 depends on DEBUG_KERNEL 793 depends on DEBUG_KERNEL
800 help 794 help
801 Enable this to turn on extended chec 795 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 796 that may impact performance.
803 797
804 If unsure, say N. 798 If unsure, say N.
805 799
806 config DEBUG_VM_SHOOT_LAZIES 800 config DEBUG_VM_SHOOT_LAZIES
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp 801 bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
808 depends on DEBUG_VM 802 depends on DEBUG_VM
809 depends on MMU_LAZY_TLB_SHOOTDOWN 803 depends on MMU_LAZY_TLB_SHOOTDOWN
810 help 804 help
811 Enable additional IPIs that ensure l 805 Enable additional IPIs that ensure lazy tlb mm references are removed
812 before the mm is freed. 806 before the mm is freed.
813 807
814 If unsure, say N. 808 If unsure, say N.
815 809
816 config DEBUG_VM_MAPLE_TREE 810 config DEBUG_VM_MAPLE_TREE
817 bool "Debug VM maple trees" 811 bool "Debug VM maple trees"
818 depends on DEBUG_VM 812 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE 813 select DEBUG_MAPLE_TREE
820 help 814 help
821 Enable VM maple tree debugging infor 815 Enable VM maple tree debugging information and extra validations.
822 816
823 If unsure, say N. 817 If unsure, say N.
824 818
825 config DEBUG_VM_RB 819 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 820 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 821 depends on DEBUG_VM
828 help 822 help
829 Enable VM red-black tree debugging i 823 Enable VM red-black tree debugging information and extra validations.
830 824
831 If unsure, say N. 825 If unsure, say N.
832 826
833 config DEBUG_VM_PGFLAGS 827 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 828 bool "Debug page-flags operations"
835 depends on DEBUG_VM 829 depends on DEBUG_VM
836 help 830 help
837 Enables extra validation on page fla 831 Enables extra validation on page flags operations.
838 832
839 If unsure, say N. 833 If unsure, say N.
840 834
841 config DEBUG_VM_PGTABLE 835 config DEBUG_VM_PGTABLE
842 bool "Debug arch page table for semant 836 bool "Debug arch page table for semantics compliance"
843 depends on MMU 837 depends on MMU
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE 838 depends on ARCH_HAS_DEBUG_VM_PGTABLE
845 default y if DEBUG_VM 839 default y if DEBUG_VM
846 help 840 help
847 This option provides a debug method 841 This option provides a debug method which can be used to test
848 architecture page table helper funct 842 architecture page table helper functions on various platforms in
849 verifying if they comply with expect 843 verifying if they comply with expected generic MM semantics. This
850 will help architecture code in makin 844 will help architecture code in making sure that any changes or
851 new additions of these helpers still 845 new additions of these helpers still conform to expected
852 semantics of the generic MM. Platfor 846 semantics of the generic MM. Platforms will have to opt in for
853 this through ARCH_HAS_DEBUG_VM_PGTAB 847 this through ARCH_HAS_DEBUG_VM_PGTABLE.
854 848
855 If unsure, say N. 849 If unsure, say N.
856 850
857 config ARCH_HAS_DEBUG_VIRTUAL 851 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 852 bool
859 853
860 config DEBUG_VIRTUAL 854 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 855 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 856 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 857 help
864 Enable some costly sanity checks in 858 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 859 catch mistakes with virt_to_page() and friends.
866 860
867 If unsure, say N. 861 If unsure, say N.
868 862
869 config DEBUG_NOMMU_REGIONS 863 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 864 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 865 depends on DEBUG_KERNEL && !MMU
872 help 866 help
873 This option causes the global tree o 867 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 868 regions to be regularly checked for invalid topology.
875 869
876 config DEBUG_MEMORY_INIT 870 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 871 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 872 default !EXPERT
879 help 873 help
880 Enable this for additional checks du 874 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 875 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 876 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 877 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 878 on the mminit_loglevel= command-line option.
885 879
886 If unsure, say Y 880 If unsure, say Y
887 881
888 config MEMORY_NOTIFIER_ERROR_INJECT 882 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 883 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ 884 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
891 help 885 help
892 This option provides the ability to 886 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 887 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 888 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 889
896 If the notifier call chain should be 890 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 891 notified, write the error code to "actions/<notifier event>/error".
898 892
899 Example: Inject memory hotplug offli 893 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 894
901 # cd /sys/kernel/debug/notifier-erro 895 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 896 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 897 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 898 bash: echo: write error: Cannot allocate memory
905 899
906 To compile this code as a module, ch 900 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 901 be called memory-notifier-error-inject.
908 902
909 If unsure, say N. 903 If unsure, say N.
910 904
911 config DEBUG_PER_CPU_MAPS 905 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 906 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 907 depends on DEBUG_KERNEL
914 depends on SMP 908 depends on SMP
915 help 909 help
916 Say Y to verify that the per_cpu map 910 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 911 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 912 and decreases performance.
919 913
920 Say N if unsure. 914 Say N if unsure.
921 915
922 config DEBUG_KMAP_LOCAL 916 config DEBUG_KMAP_LOCAL
923 bool "Debug kmap_local temporary mappi 917 bool "Debug kmap_local temporary mappings"
924 depends on DEBUG_KERNEL && KMAP_LOCAL 918 depends on DEBUG_KERNEL && KMAP_LOCAL
925 help 919 help
926 This option enables additional error 920 This option enables additional error checking for the kmap_local
927 infrastructure. Disable for product 921 infrastructure. Disable for production use.
928 922
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP 923 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
930 bool 924 bool
931 925
932 config DEBUG_KMAP_LOCAL_FORCE_MAP 926 config DEBUG_KMAP_LOCAL_FORCE_MAP
933 bool "Enforce kmap_local temporary map 927 bool "Enforce kmap_local temporary mappings"
934 depends on DEBUG_KERNEL && ARCH_SUPPOR 928 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935 select KMAP_LOCAL 929 select KMAP_LOCAL
936 select DEBUG_KMAP_LOCAL 930 select DEBUG_KMAP_LOCAL
937 help 931 help
938 This option enforces temporary mappi 932 This option enforces temporary mappings through the kmap_local
939 mechanism for non-highmem pages and 933 mechanism for non-highmem pages and on non-highmem systems.
940 Disable this for production systems! 934 Disable this for production systems!
941 935
942 config DEBUG_HIGHMEM 936 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 937 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 938 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A 939 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
946 select DEBUG_KMAP_LOCAL 940 select DEBUG_KMAP_LOCAL
947 help 941 help
948 This option enables additional error 942 This option enables additional error checking for high memory
949 systems. Disable for production sys 943 systems. Disable for production systems.
950 944
951 config HAVE_DEBUG_STACKOVERFLOW 945 config HAVE_DEBUG_STACKOVERFLOW
952 bool 946 bool
953 947
954 config DEBUG_STACKOVERFLOW 948 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 949 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 950 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help 951 help
958 Say Y here if you want to check for 952 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 953 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 954 option will show detailed messages if free stack space drops
961 below a certain limit. 955 below a certain limit.
962 956
963 These kinds of bugs usually occur wh 957 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 958 kernel get too deep, especially when interrupts are
965 involved. 959 involved.
966 960
967 Use this in cases where you see appa 961 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 962 corruption, especially if it appears in 'struct thread_info'
969 963
970 If in doubt, say "N". 964 If in doubt, say "N".
971 965
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" 966 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" 967 source "lib/Kconfig.kfence"
1005 source "lib/Kconfig.kmsan" 968 source "lib/Kconfig.kmsan"
1006 969
1007 endmenu # "Memory Debugging" 970 endmenu # "Memory Debugging"
1008 971
1009 config DEBUG_SHIRQ 972 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 973 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 974 depends on DEBUG_KERNEL
1012 help 975 help
1013 Enable this to generate a spurious 976 Enable this to generate a spurious interrupt just before a shared
1014 interrupt handler is deregistered ( 977 interrupt handler is deregistered (generating one when registering
1015 is currently disabled). Drivers nee 978 is currently disabled). Drivers need to handle this correctly. Some
1016 don't and need to be caught. 979 don't and need to be caught.
1017 980
1018 menu "Debug Oops, Lockups and Hangs" 981 menu "Debug Oops, Lockups and Hangs"
1019 982
1020 config PANIC_ON_OOPS 983 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 984 bool "Panic on Oops"
1022 help 985 help
1023 Say Y here to enable the kernel to 986 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 987 has the same effect as setting oops=panic on the kernel command
1025 line. 988 line.
1026 989
1027 This feature is useful to ensure th 990 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 991 anything erroneous after an oops which could result in data
1029 corruption or other issues. 992 corruption or other issues.
1030 993
1031 Say N if unsure. 994 Say N if unsure.
1032 995
1033 config PANIC_ON_OOPS_VALUE 996 config PANIC_ON_OOPS_VALUE
1034 int 997 int
1035 range 0 1 998 range 0 1
1036 default 0 if !PANIC_ON_OOPS 999 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 1000 default 1 if PANIC_ON_OOPS
1038 1001
1039 config PANIC_TIMEOUT 1002 config PANIC_TIMEOUT
1040 int "panic timeout" 1003 int "panic timeout"
1041 default 0 1004 default 0
1042 help 1005 help
1043 Set the timeout value (in seconds) 1006 Set the timeout value (in seconds) until a reboot occurs when
1044 the kernel panics. If n = 0, then w 1007 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 1008 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 1009 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 1010
1050 config LOCKUP_DETECTOR 1011 config LOCKUP_DETECTOR
1051 bool 1012 bool
1052 1013
1053 config SOFTLOCKUP_DETECTOR 1014 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 1015 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 1016 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 1017 select LOCKUP_DETECTOR
1057 help 1018 help
1058 Say Y here to enable the kernel to 1019 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 1020 soft lockups.
1060 1021
1061 Softlockups are bugs that cause the 1022 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 1023 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 1024 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 1025 detection and the system will stay locked up.
1065 1026
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 1027 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 1028 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 1029 depends on SOFTLOCKUP_DETECTOR
1083 help 1030 help
1084 Say Y here to enable the kernel to 1031 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 1032 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 1033 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 1034 sysctl), without giving other tasks a chance to run.
1088 1035
1089 The panic can be used in combinatio 1036 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 1037 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 1038 lockup has been detected. This feature is useful for
1092 high-availability systems that have 1039 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 1040 where a lockup must be resolved ASAP.
1094 1041
1095 Say N if unsure. 1042 Say N if unsure.
1096 1043
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY 1044 config HAVE_HARDLOCKUP_DETECTOR_BUDDY
1098 bool 1045 bool
1099 depends on SMP 1046 depends on SMP
1100 default y 1047 default y
1101 1048
1102 # 1049 #
1103 # Global switch whether to build a hardlockup 1050 # Global switch whether to build a hardlockup detector at all. It is available
1104 # only when the architecture supports at leas 1051 # only when the architecture supports at least one implementation. There are
1105 # two exceptions. The hardlockup detector is 1052 # two exceptions. The hardlockup detector is never enabled on:
1106 # 1053 #
1107 # s390: it reported many false positive 1054 # s390: it reported many false positives there
1108 # 1055 #
1109 # sparc64: has a custom implementation 1056 # sparc64: has a custom implementation which is not using the common
1110 # hardlockup command line optio 1057 # hardlockup command line options and sysctl interface.
1111 # 1058 #
1112 config HARDLOCKUP_DETECTOR 1059 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 1060 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! 1061 depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P 1062 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1116 imply HARDLOCKUP_DETECTOR_PERF 1063 imply HARDLOCKUP_DETECTOR_PERF
1117 imply HARDLOCKUP_DETECTOR_BUDDY 1064 imply HARDLOCKUP_DETECTOR_BUDDY
1118 imply HARDLOCKUP_DETECTOR_ARCH 1065 imply HARDLOCKUP_DETECTOR_ARCH
1119 select LOCKUP_DETECTOR 1066 select LOCKUP_DETECTOR
1120 1067
1121 help 1068 help
1122 Say Y here to enable the kernel to 1069 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 1070 hard lockups.
1124 1071
1125 Hardlockups are bugs that cause the 1072 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 1073 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 1074 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 1075 and the system will stay locked up.
1129 1076
1130 # 1077 #
1131 # Note that arch-specific variants are always 1078 # Note that arch-specific variants are always preferred.
1132 # 1079 #
1133 config HARDLOCKUP_DETECTOR_PREFER_BUDDY 1080 config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1134 bool "Prefer the buddy CPU hardlockup 1081 bool "Prefer the buddy CPU hardlockup detector"
1135 depends on HARDLOCKUP_DETECTOR 1082 depends on HARDLOCKUP_DETECTOR
1136 depends on HAVE_HARDLOCKUP_DETECTOR_P 1083 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
1137 depends on !HAVE_HARDLOCKUP_DETECTOR_ 1084 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1138 help 1085 help
1139 Say Y here to prefer the buddy hard 1086 Say Y here to prefer the buddy hardlockup detector over the perf one.
1140 1087
1141 With the buddy detector, each CPU u 1088 With the buddy detector, each CPU uses its softlockup hrtimer
1142 to check that the next CPU is proce 1089 to check that the next CPU is processing hrtimer interrupts by
1143 verifying that a counter is increas 1090 verifying that a counter is increasing.
1144 1091
1145 This hardlockup detector is useful 1092 This hardlockup detector is useful on systems that don't have
1146 an arch-specific hardlockup detecto 1093 an arch-specific hardlockup detector or if resources needed
1147 for the hardlockup detector are bet 1094 for the hardlockup detector are better used for other things.
1148 1095
1149 config HARDLOCKUP_DETECTOR_PERF 1096 config HARDLOCKUP_DETECTOR_PERF
1150 bool 1097 bool
1151 depends on HARDLOCKUP_DETECTOR 1098 depends on HARDLOCKUP_DETECTOR
1152 depends on HAVE_HARDLOCKUP_DETECTOR_P 1099 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
1153 depends on !HAVE_HARDLOCKUP_DETECTOR_ 1100 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1154 select HARDLOCKUP_DETECTOR_COUNTS_HRT 1101 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1155 1102
1156 config HARDLOCKUP_DETECTOR_BUDDY 1103 config HARDLOCKUP_DETECTOR_BUDDY
1157 bool 1104 bool
1158 depends on HARDLOCKUP_DETECTOR 1105 depends on HARDLOCKUP_DETECTOR
1159 depends on HAVE_HARDLOCKUP_DETECTOR_B 1106 depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1160 depends on !HAVE_HARDLOCKUP_DETECTOR_ 1107 depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
1161 depends on !HAVE_HARDLOCKUP_DETECTOR_ 1108 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1162 select HARDLOCKUP_DETECTOR_COUNTS_HRT 1109 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1163 1110
1164 config HARDLOCKUP_DETECTOR_ARCH 1111 config HARDLOCKUP_DETECTOR_ARCH
1165 bool 1112 bool
1166 depends on HARDLOCKUP_DETECTOR 1113 depends on HARDLOCKUP_DETECTOR
1167 depends on HAVE_HARDLOCKUP_DETECTOR_A 1114 depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1168 help 1115 help
1169 The arch-specific implementation of 1116 The arch-specific implementation of the hardlockup detector will
1170 be used. 1117 be used.
1171 1118
1172 # 1119 #
1173 # Both the "perf" and "buddy" hardlockup dete 1120 # Both the "perf" and "buddy" hardlockup detectors count hrtimer
1174 # interrupts. This config enables functions m 1121 # interrupts. This config enables functions managing this common code.
1175 # 1122 #
1176 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER 1123 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1177 bool 1124 bool
1178 select SOFTLOCKUP_DETECTOR 1125 select SOFTLOCKUP_DETECTOR
1179 1126
1180 # 1127 #
1181 # Enables a timestamp based low pass filter t 1128 # Enables a timestamp based low pass filter to compensate for perf based
1182 # hard lockup detection which runs too fast d 1129 # hard lockup detection which runs too fast due to turbo modes.
1183 # 1130 #
1184 config HARDLOCKUP_CHECK_TIMESTAMP 1131 config HARDLOCKUP_CHECK_TIMESTAMP
1185 bool 1132 bool
1186 1133
1187 config BOOTPARAM_HARDLOCKUP_PANIC 1134 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 1135 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 1136 depends on HARDLOCKUP_DETECTOR
1190 help 1137 help
1191 Say Y here to enable the kernel to 1138 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 1139 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 1140 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 1141 using the watchdog_thresh sysctl).
1195 1142
1196 Say N if unsure. 1143 Say N if unsure.
1197 1144
1198 config DETECT_HUNG_TASK 1145 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 1146 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 1147 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 1148 default SOFTLOCKUP_DETECTOR
1202 help 1149 help
1203 Say Y here to enable the kernel to 1150 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 1151 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 1152 uninterruptible "D" state indefinitely.
1206 1153
1207 When a hung task is detected, the k 1154 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 1155 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 1156 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 1157 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 1158 feature has negligible overhead.
1212 1159
1213 config DEFAULT_HUNG_TASK_TIMEOUT 1160 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 1161 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 1162 depends on DETECT_HUNG_TASK
1216 default 120 1163 default 120
1217 help 1164 help
1218 This option controls the default ti 1165 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 1166 to determine when a task has become non-responsive and should
1220 be considered hung. 1167 be considered hung.
1221 1168
1222 It can be adjusted at runtime via t 1169 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 1170 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 1171 /proc/sys/kernel/hung_task_timeout_secs.
1225 1172
1226 A timeout of 0 disables the check. 1173 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 1174 Keeping the default should be fine in most cases.
1228 1175
1229 config BOOTPARAM_HUNG_TASK_PANIC 1176 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 1177 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 1178 depends on DETECT_HUNG_TASK
1232 help 1179 help
1233 Say Y here to enable the kernel to 1180 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 1181 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 1182 in uninterruptible "D" state.
1236 1183
1237 The panic can be used in combinatio 1184 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 1185 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 1186 hung task has been detected. This feature is useful for
1240 high-availability systems that have 1187 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 1188 where a hung tasks must be resolved ASAP.
1242 1189
1243 Say N if unsure. 1190 Say N if unsure.
1244 1191
1245 config WQ_WATCHDOG 1192 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 1193 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 1194 depends on DEBUG_KERNEL
1248 help 1195 help
1249 Say Y here to enable stall detectio 1196 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 1197 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 1198 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 1199 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 1200 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 1201 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 1202
1256 config WQ_CPU_INTENSIVE_REPORT 1203 config WQ_CPU_INTENSIVE_REPORT
1257 bool "Report per-cpu work items which 1204 bool "Report per-cpu work items which hog CPU for too long"
1258 depends on DEBUG_KERNEL 1205 depends on DEBUG_KERNEL
1259 help 1206 help
1260 Say Y here to enable reporting of c 1207 Say Y here to enable reporting of concurrency-managed per-cpu work
1261 items that hog CPUs for longer than 1208 items that hog CPUs for longer than
1262 workqueue.cpu_intensive_thresh_us. 1209 workqueue.cpu_intensive_thresh_us. Workqueue automatically
1263 detects and excludes them from conc 1210 detects and excludes them from concurrency management to prevent
1264 them from stalling other per-cpu wo 1211 them from stalling other per-cpu work items. Occassional
1265 triggering may not necessarily indi 1212 triggering may not necessarily indicate a problem. Repeated
1266 triggering likely indicates that th 1213 triggering likely indicates that the work item should be switched
1267 to use an unbound workqueue. 1214 to use an unbound workqueue.
1268 1215
1269 config TEST_LOCKUP 1216 config TEST_LOCKUP
1270 tristate "Test module to generate loc 1217 tristate "Test module to generate lockups"
1271 depends on m 1218 depends on m
1272 help 1219 help
1273 This builds the "test_lockup" modul 1220 This builds the "test_lockup" module that helps to make sure
1274 that watchdogs and lockup detectors 1221 that watchdogs and lockup detectors are working properly.
1275 1222
1276 Depending on module parameters it c 1223 Depending on module parameters it could emulate soft or hard
1277 lockup, "hung task", or locking arb 1224 lockup, "hung task", or locking arbitrary lock for a long time.
1278 Also it could generate series of lo 1225 Also it could generate series of lockups with cooling-down periods.
1279 1226
1280 If unsure, say N. 1227 If unsure, say N.
1281 1228
1282 endmenu # "Debug lockups and hangs" 1229 endmenu # "Debug lockups and hangs"
1283 1230
1284 menu "Scheduler Debugging" 1231 menu "Scheduler Debugging"
1285 1232
1286 config SCHED_DEBUG 1233 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 1234 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS 1235 depends on DEBUG_KERNEL && DEBUG_FS
1289 default y 1236 default y
1290 help 1237 help
1291 If you say Y here, the /sys/kernel/ 1238 If you say Y here, the /sys/kernel/debug/sched file will be provided
1292 that can help debug the scheduler. 1239 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 1240 option is minimal.
1294 1241
1295 config SCHED_INFO 1242 config SCHED_INFO
1296 bool 1243 bool
1297 default n 1244 default n
1298 1245
1299 config SCHEDSTATS 1246 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1247 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1248 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1249 select SCHED_INFO
1303 help 1250 help
1304 If you say Y here, additional code 1251 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1252 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1253 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1254 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1255 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1256 application, you can say N to avoid the very slight overhead
1310 this adds. 1257 this adds.
1311 1258
1312 endmenu 1259 endmenu
1313 1260
1314 config DEBUG_TIMEKEEPING 1261 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1262 bool "Enable extra timekeeping sanity checking"
1316 help 1263 help
1317 This option will enable additional 1264 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1265 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1266 problems are suspected.
1320 1267
1321 This may include checks in the time 1268 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1269 option may have a (very small) performance impact to some
1323 workloads. 1270 workloads.
1324 1271
1325 If unsure, say N. 1272 If unsure, say N.
1326 1273
1327 config DEBUG_PREEMPT 1274 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1275 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION 1276 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1330 help 1277 help
1331 If you say Y here then the kernel w 1278 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1279 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1280 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1281 will detect preemption count underflows.
1335 1282
1336 This option has potential to introd 1283 This option has potential to introduce high runtime overhead,
1337 depending on workload as it trigger 1284 depending on workload as it triggers debugging routines for each
1338 this_cpu operation. It should only 1285 this_cpu operation. It should only be used for debugging purposes.
1339 1286
1340 menu "Lock Debugging (spinlocks, mutexes, etc 1287 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1288
1342 config LOCK_DEBUGGING_SUPPORT 1289 config LOCK_DEBUGGING_SUPPORT
1343 bool 1290 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1291 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1292 default y
1346 1293
1347 config PROVE_LOCKING 1294 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1295 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1296 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1297 select LOCKDEP
1351 select DEBUG_SPINLOCK 1298 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT 1299 select DEBUG_MUTEXES if !PREEMPT_RT
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1300 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1301 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1302 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1303 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE 1304 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358 select TRACE_IRQFLAGS 1305 select TRACE_IRQFLAGS
1359 default n 1306 default n
1360 help 1307 help
1361 This feature enables the kernel to p 1308 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1309 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1310 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1311 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1312 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1313 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1314 deadlock.
1368 1315
1369 In short, this feature enables the k 1316 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1317 related deadlocks before they actually occur.
1371 1318
1372 The proof does not depend on how har 1319 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1320 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1321 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1322 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1323 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1324 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1325 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1326 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1327 makes the deadlock theoretically possible).
1381 1328
1382 If a deadlock is impossible (i.e. th 1329 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1330 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1331 kernel reports nothing.
1385 1332
1386 NOTE: this feature can also be enabl 1333 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1334 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1335 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1336 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1337 arbitrary combination of these separate locking variants.
1391 1338
1392 For more details, see Documentation/ 1339 For more details, see Documentation/locking/lockdep-design.rst.
1393 1340
1394 config PROVE_RAW_LOCK_NESTING 1341 config PROVE_RAW_LOCK_NESTING
1395 bool "Enable raw_spinlock - spinlock 1342 bool "Enable raw_spinlock - spinlock nesting checks"
1396 depends on PROVE_LOCKING 1343 depends on PROVE_LOCKING
1397 default n 1344 default n
1398 help 1345 help
1399 Enable the raw_spinlock vs. spinlock 1346 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400 that the lock nesting rules for PREE 1347 that the lock nesting rules for PREEMPT_RT enabled kernels are
1401 not violated. 1348 not violated.
1402 1349
1403 NOTE: There are known nesting proble 1350 NOTE: There are known nesting problems. So if you enable this
1404 option expect lockdep splats until t 1351 option expect lockdep splats until these problems have been fully
1405 addressed which is work in progress. 1352 addressed which is work in progress. This config switch allows to
1406 identify and analyze these problems. 1353 identify and analyze these problems. It will be removed and the
1407 check permanently enabled once the m 1354 check permanently enabled once the main issues have been fixed.
1408 1355
1409 If unsure, select N. 1356 If unsure, select N.
1410 1357
1411 config LOCK_STAT 1358 config LOCK_STAT
1412 bool "Lock usage statistics" 1359 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1360 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1361 select LOCKDEP
1415 select DEBUG_SPINLOCK 1362 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT 1363 select DEBUG_MUTEXES if !PREEMPT_RT
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1364 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1365 select DEBUG_LOCK_ALLOC
1419 default n 1366 default n
1420 help 1367 help
1421 This feature enables tracking lock c 1368 This feature enables tracking lock contention points
1422 1369
1423 For more details, see Documentation/ 1370 For more details, see Documentation/locking/lockstat.rst
1424 1371
1425 This also enables lock events requir 1372 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1373 subcommand of perf.
1427 If you want to use "perf lock", you 1374 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1375 CONFIG_EVENT_TRACING.
1429 1376
1430 CONFIG_LOCK_STAT defines "contended" 1377 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1378 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1379
1433 config DEBUG_RT_MUTEXES 1380 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1381 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1382 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1383 help
1437 This allows rt mutex semantics viola 1384 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1385 deadlocks (lockups) to be detected and reported automatically.
1439 1386
1440 config DEBUG_SPINLOCK 1387 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1388 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1389 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1390 select UNINLINE_SPIN_UNLOCK
1444 help 1391 help
1445 Say Y here and build SMP to catch m 1392 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1393 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1394 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1395 deadlocks are also debuggable.
1449 1396
1450 config DEBUG_MUTEXES 1397 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1398 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R 1399 depends on DEBUG_KERNEL && !PREEMPT_RT
1453 help 1400 help
1454 This feature allows mutex semantics 1401 This feature allows mutex semantics violations to be detected and
1455 reported. 1402 reported.
1456 1403
1457 config DEBUG_WW_MUTEX_SLOWPATH 1404 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1405 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1406 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1407 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1408 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT 1409 select DEBUG_MUTEXES if !PREEMPT_RT
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT 1410 select DEBUG_RT_MUTEXES if PREEMPT_RT
1464 help 1411 help
1465 This feature enables slowpath testin 1412 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1413 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1414 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1415 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1416 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1417 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1418 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1419 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1420 you are a distro, do not.
1474 1421
1475 config DEBUG_RWSEMS 1422 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1423 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1424 depends on DEBUG_KERNEL
1478 help 1425 help
1479 This debugging feature allows misma 1426 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1427 and unlocks to be detected and reported.
1481 1428
1482 config DEBUG_LOCK_ALLOC 1429 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1430 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1431 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1432 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT 1433 select DEBUG_MUTEXES if !PREEMPT_RT
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1434 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1435 select LOCKDEP
1489 help 1436 help
1490 This feature will check whether any 1437 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1438 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1439 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1440 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1441 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1442 held during task exit.
1496 1443
1497 config LOCKDEP 1444 config LOCKDEP
1498 bool 1445 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1446 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1447 select STACKTRACE
1501 select KALLSYMS 1448 select KALLSYMS
1502 select KALLSYMS_ALL 1449 select KALLSYMS_ALL
1503 1450
1504 config LOCKDEP_SMALL 1451 config LOCKDEP_SMALL
1505 bool 1452 bool
1506 1453
1507 config LOCKDEP_BITS 1454 config LOCKDEP_BITS
1508 int "Bitsize for MAX_LOCKDEP_ENTRIES" 1455 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1509 depends on LOCKDEP && !LOCKDEP_SMALL 1456 depends on LOCKDEP && !LOCKDEP_SMALL
1510 range 10 30 1457 range 10 30
1511 default 15 1458 default 15
1512 help 1459 help
1513 Try increasing this value if you hi 1460 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1514 1461
1515 config LOCKDEP_CHAINS_BITS 1462 config LOCKDEP_CHAINS_BITS
1516 int "Bitsize for MAX_LOCKDEP_CHAINS" 1463 int "Bitsize for MAX_LOCKDEP_CHAINS"
1517 depends on LOCKDEP && !LOCKDEP_SMALL 1464 depends on LOCKDEP && !LOCKDEP_SMALL
1518 range 10 30 1465 range 10 30
1519 default 16 1466 default 16
1520 help 1467 help
1521 Try increasing this value if you hi 1468 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1522 1469
1523 config LOCKDEP_STACK_TRACE_BITS 1470 config LOCKDEP_STACK_TRACE_BITS
1524 int "Bitsize for MAX_STACK_TRACE_ENTR 1471 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1525 depends on LOCKDEP && !LOCKDEP_SMALL 1472 depends on LOCKDEP && !LOCKDEP_SMALL
1526 range 10 30 1473 range 10 30
1527 default 19 1474 default 19
1528 help 1475 help
1529 Try increasing this value if you hi 1476 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1530 1477
1531 config LOCKDEP_STACK_TRACE_HASH_BITS 1478 config LOCKDEP_STACK_TRACE_HASH_BITS
1532 int "Bitsize for STACK_TRACE_HASH_SIZ 1479 int "Bitsize for STACK_TRACE_HASH_SIZE"
1533 depends on LOCKDEP && !LOCKDEP_SMALL 1480 depends on LOCKDEP && !LOCKDEP_SMALL
1534 range 10 30 1481 range 10 30
1535 default 14 1482 default 14
1536 help 1483 help
1537 Try increasing this value if you ne 1484 Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1538 1485
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS 1486 config LOCKDEP_CIRCULAR_QUEUE_BITS
1540 int "Bitsize for elements in circular 1487 int "Bitsize for elements in circular_queue struct"
1541 depends on LOCKDEP 1488 depends on LOCKDEP
1542 range 10 30 1489 range 10 30
1543 default 12 1490 default 12
1544 help 1491 help
1545 Try increasing this value if you hi 1492 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1546 1493
1547 config DEBUG_LOCKDEP 1494 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1495 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1496 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS 1497 select DEBUG_IRQFLAGS
1551 help 1498 help
1552 If you say Y here, the lock depende 1499 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1500 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1501 of more runtime overhead.
1555 1502
1556 config DEBUG_ATOMIC_SLEEP 1503 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1504 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1505 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1506 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1507 depends on !ARCH_NO_PREEMPT
1561 help 1508 help
1562 If you say Y here, various routines 1509 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1510 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1511 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1512 sections, inside an interrupt, etc...
1566 1513
1567 config DEBUG_LOCKING_API_SELFTESTS 1514 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1515 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1516 depends on DEBUG_KERNEL
1570 help 1517 help
1571 Say Y here if you want the kernel t 1518 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1519 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1520 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' 1521 lock debugging then those bugs won't be detected of course.)
1575 The following locking APIs are cove 1522 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1523 mutexes and rwsems.
1577 1524
1578 config LOCK_TORTURE_TEST 1525 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1526 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1527 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1528 select TORTURE_TEST
1582 help 1529 help
1583 This option provides a kernel modul 1530 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1531 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1532 after the fact on the running kernel to be tested, if desired.
1586 1533
1587 Say Y here if you want kernel locki 1534 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1535 to be built into the kernel.
1589 Say M if you want these torture tes 1536 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1537 Say N if you are unsure.
1591 1538
1592 config WW_MUTEX_SELFTEST 1539 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1540 tristate "Wait/wound mutex selftests"
1594 help 1541 help
1595 This option provides a kernel modul 1542 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1543 on the struct ww_mutex locking API.
1597 1544
1598 It is recommended to enable DEBUG_W 1545 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1546 with this test harness.
1600 1547
1601 Say M if you want these self tests 1548 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1549 Say N if you are unsure.
1603 1550
1604 config SCF_TORTURE_TEST 1551 config SCF_TORTURE_TEST
1605 tristate "torture tests for smp_call_ 1552 tristate "torture tests for smp_call_function*()"
1606 depends on DEBUG_KERNEL 1553 depends on DEBUG_KERNEL
1607 select TORTURE_TEST 1554 select TORTURE_TEST
1608 help 1555 help
1609 This option provides a kernel modul 1556 This option provides a kernel module that runs torture tests
1610 on the smp_call_function() family o 1557 on the smp_call_function() family of primitives. The kernel
1611 module may be built after the fact 1558 module may be built after the fact on the running kernel to
1612 be tested, if desired. 1559 be tested, if desired.
1613 1560
1614 config CSD_LOCK_WAIT_DEBUG 1561 config CSD_LOCK_WAIT_DEBUG
1615 bool "Debugging for csd_lock_wait(), 1562 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616 depends on DEBUG_KERNEL 1563 depends on DEBUG_KERNEL
1617 depends on 64BIT 1564 depends on 64BIT
1618 default n 1565 default n
1619 help 1566 help
1620 This option enables debug prints wh 1567 This option enables debug prints when CPUs are slow to respond
1621 to the smp_call_function*() IPI wra 1568 to the smp_call_function*() IPI wrappers. These debug prints
1622 include the IPI handler function cu 1569 include the IPI handler function currently executing (if any)
1623 and relevant stack traces. 1570 and relevant stack traces.
1624 1571
1625 config CSD_LOCK_WAIT_DEBUG_DEFAULT 1572 config CSD_LOCK_WAIT_DEBUG_DEFAULT
1626 bool "Default csd_lock_wait() debuggi 1573 bool "Default csd_lock_wait() debugging on at boot time"
1627 depends on CSD_LOCK_WAIT_DEBUG 1574 depends on CSD_LOCK_WAIT_DEBUG
1628 depends on 64BIT 1575 depends on 64BIT
1629 default n 1576 default n
1630 help 1577 help
1631 This option causes the csdlock_debu 1578 This option causes the csdlock_debug= kernel boot parameter to
1632 default to 1 (basic debugging) inst 1579 default to 1 (basic debugging) instead of 0 (no debugging).
1633 1580
1634 endmenu # lock debugging 1581 endmenu # lock debugging
1635 1582
1636 config TRACE_IRQFLAGS 1583 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT 1584 depends on TRACE_IRQFLAGS_SUPPORT
1638 bool 1585 bool
1639 help 1586 help
1640 Enables hooks to interrupt enabling 1587 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1588 either tracing or lock debugging.
1642 1589
1643 config TRACE_IRQFLAGS_NMI 1590 config TRACE_IRQFLAGS_NMI
1644 def_bool y 1591 def_bool y
1645 depends on TRACE_IRQFLAGS 1592 depends on TRACE_IRQFLAGS
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT 1593 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647 1594
1648 config NMI_CHECK_CPU 1595 config NMI_CHECK_CPU
1649 bool "Debugging for CPUs failing to r 1596 bool "Debugging for CPUs failing to respond to backtrace requests"
1650 depends on DEBUG_KERNEL 1597 depends on DEBUG_KERNEL
1651 depends on X86 1598 depends on X86
1652 default n 1599 default n
1653 help 1600 help
1654 Enables debug prints when a CPU fai 1601 Enables debug prints when a CPU fails to respond to a given
1655 backtrace NMI. These prints provid 1602 backtrace NMI. These prints provide some reasons why a CPU
1656 might legitimately be failing to re 1603 might legitimately be failing to respond, for example, if it
1657 is offline of if ignore_nmis is set 1604 is offline of if ignore_nmis is set.
1658 1605
1659 config DEBUG_IRQFLAGS 1606 config DEBUG_IRQFLAGS
1660 bool "Debug IRQ flag manipulation" 1607 bool "Debug IRQ flag manipulation"
1661 help 1608 help
1662 Enables checks for potentially unsa 1609 Enables checks for potentially unsafe enabling or disabling of
1663 interrupts, such as calling raw_loc 1610 interrupts, such as calling raw_local_irq_restore() when interrupts
1664 are enabled. 1611 are enabled.
1665 1612
1666 config STACKTRACE 1613 config STACKTRACE
1667 bool "Stack backtrace support" 1614 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1615 depends on STACKTRACE_SUPPORT
1669 help 1616 help
1670 This option causes the kernel to cr 1617 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1618 every process, showing its current stack trace.
1672 It is also used by various kernel d 1619 It is also used by various kernel debugging features that require
1673 stack trace generation. 1620 stack trace generation.
1674 1621
1675 config WARN_ALL_UNSEEDED_RANDOM 1622 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1623 bool "Warn for all uses of unseeded randomness"
1677 default n 1624 default n
1678 help 1625 help
1679 Some parts of the kernel contain bu 1626 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1627 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1628 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1629 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1630 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1631 are going wrong, so that they might contact developers about fixing
1685 it. 1632 it.
1686 1633
1687 Unfortunately, on some models of so 1634 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1635 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1636 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1637 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1638 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1639 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1640 However, since users cannot do anything actionable to
1694 address this, by default this optio 1641 address this, by default this option is disabled.
1695 1642
1696 Say Y here if you want to receive w 1643 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1644 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1645 those developers interested in improving the security of
1699 Linux kernels running on their arch 1646 Linux kernels running on their architecture (or
1700 subarchitecture). 1647 subarchitecture).
1701 1648
1702 config DEBUG_KOBJECT 1649 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1650 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1651 depends on DEBUG_KERNEL
1705 help 1652 help
1706 If you say Y here, some extra kobje 1653 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1654 to the syslog.
1708 1655
1709 config DEBUG_KOBJECT_RELEASE 1656 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1657 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1658 depends on DEBUG_OBJECTS_TIMERS
1712 help 1659 help
1713 kobjects are reference counted obje 1660 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1661 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d 1662 live on past the point at which a driver decides to drop its
1716 initial reference to the kobject ga 1663 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1664 example of this would be a struct device which has just been
1718 unregistered. 1665 unregistered.
1719 1666
1720 However, some buggy drivers assume 1667 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1668 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1669 goes completely against the principles of a refcounted object.
1723 1670
1724 If you say Y here, the kernel will 1671 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1672 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1673 kind of kobject release bug.
1727 1674
1728 config HAVE_DEBUG_BUGVERBOSE 1675 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1676 bool
1730 1677
1731 menu "Debug kernel data structures" 1678 menu "Debug kernel data structures"
1732 1679
1733 config DEBUG_LIST 1680 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1681 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL 1682 depends on DEBUG_KERNEL
1736 select LIST_HARDENED 1683 select LIST_HARDENED
1737 help 1684 help
1738 Enable this to turn on extended che 1685 Enable this to turn on extended checks in the linked-list walking
1739 routines. 1686 routines.
1740 1687
1741 This option trades better quality e 1688 This option trades better quality error reports for performance, and
1742 is more suitable for kernel debuggi 1689 is more suitable for kernel debugging. If you care about performance,
1743 you should only enable CONFIG_LIST_ 1690 you should only enable CONFIG_LIST_HARDENED instead.
1744 1691
1745 If unsure, say N. 1692 If unsure, say N.
1746 1693
1747 config DEBUG_PLIST 1694 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1695 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1696 depends on DEBUG_KERNEL
1750 help 1697 help
1751 Enable this to turn on extended che 1698 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1699 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1700 list multiple times during each manipulation.
1754 1701
1755 If unsure, say N. 1702 If unsure, say N.
1756 1703
1757 config DEBUG_SG 1704 config DEBUG_SG
1758 bool "Debug SG table operations" 1705 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1706 depends on DEBUG_KERNEL
1760 help 1707 help
1761 Enable this to turn on checks on sc 1708 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1709 help find problems with drivers that do not properly initialize
1763 their sg tables. 1710 their sg tables.
1764 1711
1765 If unsure, say N. 1712 If unsure, say N.
1766 1713
1767 config DEBUG_NOTIFIERS 1714 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1715 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1716 depends on DEBUG_KERNEL
1770 help 1717 help
1771 Enable this to turn on sanity check 1718 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1719 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1720 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1721 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1722 performance, say N.
1776 1723
1777 config DEBUG_CLOSURES <<
1778 bool "Debug closures (bcache async wi <<
1779 depends on CLOSURES <<
1780 select DEBUG_FS <<
1781 help <<
1782 Keeps all active closures in a link <<
1783 interface to list them, which makes <<
1784 operations that get stuck. <<
1785 <<
1786 config DEBUG_MAPLE_TREE 1724 config DEBUG_MAPLE_TREE
1787 bool "Debug maple trees" 1725 bool "Debug maple trees"
1788 depends on DEBUG_KERNEL 1726 depends on DEBUG_KERNEL
1789 help 1727 help
1790 Enable maple tree debugging informa 1728 Enable maple tree debugging information and extra validations.
1791 1729
1792 If unsure, say N. 1730 If unsure, say N.
1793 1731
1794 endmenu 1732 endmenu
1795 1733
1796 source "kernel/rcu/Kconfig.debug" 1734 source "kernel/rcu/Kconfig.debug"
1797 1735
1798 config DEBUG_WQ_FORCE_RR_CPU 1736 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1737 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1738 depends on DEBUG_KERNEL
1801 default n 1739 default n
1802 help 1740 help
1803 Workqueue used to implicitly guaran 1741 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1742 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1743 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1744 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1745 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1746 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1747 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1748 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1749 be impacted.
1812 1750
1813 config CPU_HOTPLUG_STATE_CONTROL 1751 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1752 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1753 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1754 depends on HOTPLUG_CPU
1817 default n 1755 default n
1818 help 1756 help
1819 Allows to write steps between "offl 1757 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1758 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1759 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1760 restarted at arbitrary points yet.
1823 1761
1824 Say N if your are unsure. 1762 Say N if your are unsure.
1825 1763
1826 config LATENCYTOP 1764 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1765 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1766 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1767 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1768 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P 1769 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832 select KALLSYMS 1770 select KALLSYMS
1833 select KALLSYMS_ALL 1771 select KALLSYMS_ALL
1834 select STACKTRACE 1772 select STACKTRACE
1835 select SCHEDSTATS 1773 select SCHEDSTATS
1836 help 1774 help
1837 Enable this option if you want to u 1775 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1776 to find out which userspace is blocking on what kernel operations.
1839 1777
1840 config DEBUG_CGROUP_REF 1778 config DEBUG_CGROUP_REF
1841 bool "Disable inlining of cgroup css 1779 bool "Disable inlining of cgroup css reference count functions"
1842 depends on DEBUG_KERNEL 1780 depends on DEBUG_KERNEL
1843 depends on CGROUPS 1781 depends on CGROUPS
1844 depends on KPROBES 1782 depends on KPROBES
1845 default n 1783 default n
1846 help 1784 help
1847 Force cgroup css reference count fu 1785 Force cgroup css reference count functions to not be inlined so
1848 that they can be kprobed for debugg 1786 that they can be kprobed for debugging.
1849 1787
1850 source "kernel/trace/Kconfig" 1788 source "kernel/trace/Kconfig"
1851 1789
1852 config PROVIDE_OHCI1394_DMA_INIT 1790 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1791 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1792 depends on PCI && X86
1855 help 1793 help
1856 If you want to debug problems which 1794 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1795 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1796 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1797 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1798 specification which is now the standard for FireWire controllers.
1861 1799
1862 With remote DMA, you can monitor th 1800 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1801 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1802 Even controlling a kernel debugger is possible using remote DMA.
1865 1803
1866 Usage: 1804 Usage:
1867 1805
1868 If ohci1394_dma=early is used as bo 1806 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1807 all OHCI1394 controllers which are found in the PCI config space.
1870 1808
1871 As all changes to the FireWire bus 1809 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1810 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1811 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1812 the debugging host before booting the debug target for debugging.
1875 1813
1876 This code (~1k) is freed after boot 1814 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1815 in charge of the OHCI-1394 controllers should be used instead.
1878 1816
1879 See Documentation/core-api/debuggin 1817 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880 1818
1881 source "samples/Kconfig" 1819 source "samples/Kconfig"
1882 1820
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1821 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1822 bool
1885 1823
1886 config STRICT_DEVMEM 1824 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1825 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1826 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED 1827 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1828 default y if PPC || X86 || ARM64
1891 help 1829 help
1892 If this option is disabled, you all 1830 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1831 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1832 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1833 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1834 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1835 use due to the cache aliasing requirements.
1898 1836
1899 If this option is switched on, and 1837 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1838 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1839 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1840 users of /dev/mem.
1903 1841
1904 If in doubt, say Y. 1842 If in doubt, say Y.
1905 1843
1906 config IO_STRICT_DEVMEM 1844 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1845 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1846 depends on STRICT_DEVMEM
1909 help 1847 help
1910 If this option is disabled, you all 1848 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1849 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1850 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1851 specific access can be used by people debugging kernel drivers.
1914 1852
1915 If this option is switched on, the 1853 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1854 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1855 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1856 if the driver using a given range cannot be disabled.
1919 1857
1920 If in doubt, say Y. 1858 If in doubt, say Y.
1921 1859
1922 menu "$(SRCARCH) Debugging" 1860 menu "$(SRCARCH) Debugging"
1923 1861
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1862 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1863
1926 endmenu 1864 endmenu
1927 1865
1928 menu "Kernel Testing and Coverage" 1866 menu "Kernel Testing and Coverage"
1929 1867
1930 source "lib/kunit/Kconfig" 1868 source "lib/kunit/Kconfig"
1931 1869
1932 config NOTIFIER_ERROR_INJECTION 1870 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1871 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1872 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1873 select DEBUG_FS
1936 help 1874 help
1937 This option provides the ability to 1875 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1876 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1877 handling of notifier call chain failures.
1940 1878
1941 Say N if unsure. 1879 Say N if unsure.
1942 1880
1943 config PM_NOTIFIER_ERROR_INJECT 1881 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1882 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1883 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1884 default m if PM_DEBUG
1947 help 1885 help
1948 This option provides the ability to 1886 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1887 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1888 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1889
1952 If the notifier call chain should b 1890 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1891 notified, write the error code to "actions/<notifier event>/error".
1954 1892
1955 Example: Inject PM suspend error (- 1893 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1894
1957 # cd /sys/kernel/debug/notifier-err 1895 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1896 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1897 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1898 bash: echo: write error: Cannot allocate memory
1961 1899
1962 To compile this code as a module, c 1900 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1901 be called pm-notifier-error-inject.
1964 1902
1965 If unsure, say N. 1903 If unsure, say N.
1966 1904
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1905 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1906 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1907 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1908 help
1971 This option provides the ability to 1909 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1910 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1911 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1912 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1913
1976 If the notifier call chain should b 1914 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1915 notified, write the error code to "actions/<notifier event>/error".
1978 1916
1979 To compile this code as a module, c 1917 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1918 be called of-reconfig-notifier-error-inject.
1981 1919
1982 If unsure, say N. 1920 If unsure, say N.
1983 1921
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1922 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1923 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1924 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1925 help
1988 This option provides the ability to 1926 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1927 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1928 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1929
1992 If the notifier call chain should b 1930 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1931 notified, write the error code to "actions/<notifier event>/error".
1994 1932
1995 Example: Inject netdevice mtu chang 1933 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1934
1997 # cd /sys/kernel/debug/notifier-err 1935 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1936 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1937 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1938 RTNETLINK answers: Invalid argument
2001 1939
2002 To compile this code as a module, c 1940 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1941 be called netdev-notifier-error-inject.
2004 1942
2005 If unsure, say N. 1943 If unsure, say N.
2006 1944
2007 config FUNCTION_ERROR_INJECTION 1945 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" 1946 bool "Fault-injections of functions"
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1947 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010 help 1948 help
2011 Add fault injections into various f 1949 Add fault injections into various functions that are annotated with
2012 ALLOW_ERROR_INJECTION() in the kern 1950 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
2013 value of these functions. This is u 1951 value of these functions. This is useful to test error paths of code.
2014 1952
2015 If unsure, say N 1953 If unsure, say N
2016 1954
2017 config FAULT_INJECTION 1955 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1956 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1957 depends on DEBUG_KERNEL
2020 help 1958 help
2021 Provide fault-injection framework. 1959 Provide fault-injection framework.
2022 For more details, see Documentation 1960 For more details, see Documentation/fault-injection/.
2023 1961
2024 config FAILSLAB 1962 config FAILSLAB
2025 bool "Fault-injection capability for 1963 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1964 depends on FAULT_INJECTION
>> 1965 depends on SLAB || SLUB
2027 help 1966 help
2028 Provide fault-injection capability 1967 Provide fault-injection capability for kmalloc.
2029 1968
2030 config FAIL_PAGE_ALLOC 1969 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for 1970 bool "Fault-injection capability for alloc_pages()"
2032 depends on FAULT_INJECTION 1971 depends on FAULT_INJECTION
2033 help 1972 help
2034 Provide fault-injection capability 1973 Provide fault-injection capability for alloc_pages().
2035 1974
2036 config FAULT_INJECTION_USERCOPY 1975 config FAULT_INJECTION_USERCOPY
2037 bool "Fault injection capability for 1976 bool "Fault injection capability for usercopy functions"
2038 depends on FAULT_INJECTION 1977 depends on FAULT_INJECTION
2039 help 1978 help
2040 Provides fault-injection capability 1979 Provides fault-injection capability to inject failures
2041 in usercopy functions (copy_from_us 1980 in usercopy functions (copy_from_user(), get_user(), ...).
2042 1981
2043 config FAIL_MAKE_REQUEST 1982 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1983 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1984 depends on FAULT_INJECTION && BLOCK
2046 help 1985 help
2047 Provide fault-injection capability 1986 Provide fault-injection capability for disk IO.
2048 1987
2049 config FAIL_IO_TIMEOUT 1988 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1989 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1990 depends on FAULT_INJECTION && BLOCK
2052 help 1991 help
2053 Provide fault-injection capability 1992 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1993 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1994 thus exercising the error handling.
2056 1995
2057 Only works with drivers that use th 1996 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. 1997 for others it won't do anything.
2059 1998
2060 config FAIL_FUTEX 1999 config FAIL_FUTEX
2061 bool "Fault-injection capability for 2000 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 2001 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 2002 depends on FAULT_INJECTION && FUTEX
2064 help 2003 help
2065 Provide fault-injection capability 2004 Provide fault-injection capability for futexes.
2066 2005
2067 config FAULT_INJECTION_DEBUG_FS 2006 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 2007 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 2008 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 2009 help
2071 Enable configuration of fault-injec 2010 Enable configuration of fault-injection capabilities via debugfs.
2072 2011
2073 config FAIL_FUNCTION 2012 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 2013 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 2014 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 2015 help
2077 Provide function-based fault-inject 2016 Provide function-based fault-injection capability.
2078 This will allow you to override a s 2017 This will allow you to override a specific function with a return
2079 with given return value. As a resul 2018 with given return value. As a result, function caller will see
2080 an error value and have to handle i 2019 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 2020 error handling in various subsystems.
2082 2021
2083 config FAIL_MMC_REQUEST 2022 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 2023 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 2024 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 2025 help
2087 Provide fault-injection capability 2026 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 2027 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 2028 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 2029 and to test how the mmc host driver handles retries from
2091 the block device. 2030 the block device.
2092 2031
2093 config FAIL_SUNRPC 2032 config FAIL_SUNRPC
2094 bool "Fault-injection capability for 2033 bool "Fault-injection capability for SunRPC"
2095 depends on FAULT_INJECTION_DEBUG_FS & 2034 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2096 help 2035 help
2097 Provide fault-injection capability 2036 Provide fault-injection capability for SunRPC and
2098 its consumers. 2037 its consumers.
2099 2038
2100 config FAULT_INJECTION_CONFIGFS 2039 config FAULT_INJECTION_CONFIGFS
2101 bool "Configfs interface for fault-in 2040 bool "Configfs interface for fault-injection capabilities"
2102 depends on FAULT_INJECTION 2041 depends on FAULT_INJECTION
2103 select CONFIGFS_FS 2042 select CONFIGFS_FS
2104 help 2043 help
2105 This option allows configfs-based d 2044 This option allows configfs-based drivers to dynamically configure
2106 fault-injection via configfs. Each 2045 fault-injection via configfs. Each parameter for driver-specific
2107 fault-injection can be made visible 2046 fault-injection can be made visible as a configfs attribute in a
2108 configfs group. 2047 configfs group.
2109 2048
2110 2049
2111 config FAULT_INJECTION_STACKTRACE_FILTER 2050 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 2051 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION 2052 depends on FAULT_INJECTION
2114 depends on (FAULT_INJECTION_DEBUG_FS 2053 depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
2115 select STACKTRACE 2054 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P 2055 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117 help 2056 help
2118 Provide stacktrace filter for fault 2057 Provide stacktrace filter for fault-injection capabilities
2119 2058
2120 config ARCH_HAS_KCOV 2059 config ARCH_HAS_KCOV
2121 bool 2060 bool
2122 help 2061 help
2123 An architecture should select this 2062 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 2063 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 2064 disabling instrumentation for some early boot code.
2126 2065
2127 config CC_HAS_SANCOV_TRACE_PC 2066 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 2067 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 2068
2130 2069
2131 config KCOV 2070 config KCOV
2132 bool "Code coverage for fuzzing" 2071 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 2072 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 2073 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2135 depends on !ARCH_WANTS_NO_INSTR || HA 2074 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2136 GCC_VERSION >= 120000 || C !! 2075 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
2137 select DEBUG_FS 2076 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 2077 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK 2078 select OBJTOOL if HAVE_NOINSTR_HACK
2140 help 2079 help
2141 KCOV exposes kernel code coverage i 2080 KCOV exposes kernel code coverage information in a form suitable
2142 for coverage-guided fuzzing (random 2081 for coverage-guided fuzzing (randomized testing).
2143 2082
>> 2083 If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> 2084 different machines and across reboots. If you need stable PC values,
>> 2085 disable RANDOMIZE_BASE.
>> 2086
2144 For more details, see Documentation 2087 For more details, see Documentation/dev-tools/kcov.rst.
2145 2088
2146 config KCOV_ENABLE_COMPARISONS 2089 config KCOV_ENABLE_COMPARISONS
2147 bool "Enable comparison operands coll 2090 bool "Enable comparison operands collection by KCOV"
2148 depends on KCOV 2091 depends on KCOV
2149 depends on $(cc-option,-fsanitize-cov 2092 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150 help 2093 help
2151 KCOV also exposes operands of every 2094 KCOV also exposes operands of every comparison in the instrumented
2152 code along with operand sizes and P 2095 code along with operand sizes and PCs of the comparison instructions.
2153 These operands can be used by fuzzi 2096 These operands can be used by fuzzing engines to improve the quality
2154 of fuzzing coverage. 2097 of fuzzing coverage.
2155 2098
2156 config KCOV_INSTRUMENT_ALL 2099 config KCOV_INSTRUMENT_ALL
2157 bool "Instrument all code by default" 2100 bool "Instrument all code by default"
2158 depends on KCOV 2101 depends on KCOV
2159 default y 2102 default y
2160 help 2103 help
2161 If you are doing generic system cal 2104 If you are doing generic system call fuzzing (like e.g. syzkaller),
2162 then you will want to instrument th 2105 then you will want to instrument the whole kernel and you should
2163 say y here. If you are doing more t 2106 say y here. If you are doing more targeted fuzzing (like e.g.
2164 filesystem fuzzing with AFL) then y 2107 filesystem fuzzing with AFL) then you will want to enable coverage
2165 for more specific subsets of files, 2108 for more specific subsets of files, and should say n here.
2166 2109
2167 config KCOV_IRQ_AREA_SIZE 2110 config KCOV_IRQ_AREA_SIZE
2168 hex "Size of interrupt coverage colle 2111 hex "Size of interrupt coverage collection area in words"
2169 depends on KCOV 2112 depends on KCOV
2170 default 0x40000 2113 default 0x40000
2171 help 2114 help
2172 KCOV uses preallocated per-cpu area 2115 KCOV uses preallocated per-cpu areas to collect coverage from
2173 soft interrupts. This specifies the 2116 soft interrupts. This specifies the size of those areas in the
2174 number of unsigned long words. 2117 number of unsigned long words.
2175 2118
2176 menuconfig RUNTIME_TESTING_MENU 2119 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 2120 bool "Runtime Testing"
2178 default y !! 2121 def_bool y
2179 2122
2180 if RUNTIME_TESTING_MENU 2123 if RUNTIME_TESTING_MENU
2181 2124
2182 config TEST_DHRY 2125 config TEST_DHRY
2183 tristate "Dhrystone benchmark test" 2126 tristate "Dhrystone benchmark test"
2184 help 2127 help
2185 Enable this to include the Dhryston 2128 Enable this to include the Dhrystone 2.1 benchmark. This test
2186 calculates the number of Dhrystones 2129 calculates the number of Dhrystones per second, and the number of
2187 DMIPS (Dhrystone MIPS) obtained whe 2130 DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2188 by 1757 (the number of Dhrystones p 2131 by 1757 (the number of Dhrystones per second obtained on the VAX
2189 11/780, nominally a 1 MIPS machine) 2132 11/780, nominally a 1 MIPS machine).
2190 2133
2191 To run the benchmark, it needs to b 2134 To run the benchmark, it needs to be enabled explicitly, either from
2192 the kernel command line (when built 2135 the kernel command line (when built-in), or from userspace (when
2193 built-in or modular). !! 2136 built-in or modular.
2194 2137
2195 Run once during kernel boot: 2138 Run once during kernel boot:
2196 2139
2197 test_dhry.run 2140 test_dhry.run
2198 2141
2199 Set number of iterations from kerne 2142 Set number of iterations from kernel command line:
2200 2143
2201 test_dhry.iterations=<n> 2144 test_dhry.iterations=<n>
2202 2145
2203 Set number of iterations from users 2146 Set number of iterations from userspace:
2204 2147
2205 echo <n> > /sys/module/test_dhr 2148 echo <n> > /sys/module/test_dhry/parameters/iterations
2206 2149
2207 Trigger manual run from userspace: 2150 Trigger manual run from userspace:
2208 2151
2209 echo y > /sys/module/test_dhry/ 2152 echo y > /sys/module/test_dhry/parameters/run
2210 2153
2211 If the number of iterations is <= 0 2154 If the number of iterations is <= 0, the test will devise a suitable
2212 number of iterations (test runs for 2155 number of iterations (test runs for at least 2s) automatically.
2213 This process takes ca. 4s. 2156 This process takes ca. 4s.
2214 2157
2215 If unsure, say N. 2158 If unsure, say N.
2216 2159
2217 config LKDTM 2160 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 2161 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 2162 depends on DEBUG_FS
2220 help 2163 help
2221 This module enables testing of the di 2164 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 2165 inducing system failures at predefined crash points.
2223 If you don't need it: say N 2166 If you don't need it: say N
2224 Choose M here to compile this code as 2167 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 2168 called lkdtm.
2226 2169
2227 Documentation on how to use the modul 2170 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 2171 Documentation/fault-injection/provoke-crashes.rst
2229 2172
2230 config CPUMASK_KUNIT_TEST 2173 config CPUMASK_KUNIT_TEST
2231 tristate "KUnit test for cpumask" if 2174 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2232 depends on KUNIT 2175 depends on KUNIT
2233 default KUNIT_ALL_TESTS 2176 default KUNIT_ALL_TESTS
2234 help 2177 help
2235 Enable to turn on cpumask tests, ru 2178 Enable to turn on cpumask tests, running at boot or module load time.
2236 2179
2237 For more information on KUnit and u 2180 For more information on KUnit and unit tests in general, please refer
2238 to the KUnit documentation in Docum 2181 to the KUnit documentation in Documentation/dev-tools/kunit/.
2239 2182
2240 If unsure, say N. 2183 If unsure, say N.
2241 2184
2242 config TEST_LIST_SORT 2185 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i 2186 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2244 depends on KUNIT 2187 depends on KUNIT
2245 default KUNIT_ALL_TESTS 2188 default KUNIT_ALL_TESTS
2246 help 2189 help
2247 Enable this to turn on 'list_sort() 2190 Enable this to turn on 'list_sort()' function test. This test is
2248 executed only once during system bo 2191 executed only once during system boot (so affects only boot time),
2249 or at module load time. 2192 or at module load time.
2250 2193
2251 If unsure, say N. 2194 If unsure, say N.
2252 2195
2253 config TEST_MIN_HEAP 2196 config TEST_MIN_HEAP
2254 tristate "Min heap test" 2197 tristate "Min heap test"
2255 depends on DEBUG_KERNEL || m 2198 depends on DEBUG_KERNEL || m
2256 help 2199 help
2257 Enable this to turn on min heap fun 2200 Enable this to turn on min heap function tests. This test is
2258 executed only once during system bo 2201 executed only once during system boot (so affects only boot time),
2259 or at module load time. 2202 or at module load time.
2260 2203
2261 If unsure, say N. 2204 If unsure, say N.
2262 2205
2263 config TEST_SORT 2206 config TEST_SORT
2264 tristate "Array-based sort test" if ! 2207 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2265 depends on KUNIT 2208 depends on KUNIT
2266 default KUNIT_ALL_TESTS 2209 default KUNIT_ALL_TESTS
2267 help 2210 help
2268 This option enables the self-test f 2211 This option enables the self-test function of 'sort()' at boot,
2269 or at module load time. 2212 or at module load time.
2270 2213
2271 If unsure, say N. 2214 If unsure, say N.
2272 2215
2273 config TEST_DIV64 2216 config TEST_DIV64
2274 tristate "64bit/32bit division and mo 2217 tristate "64bit/32bit division and modulo test"
2275 depends on DEBUG_KERNEL || m 2218 depends on DEBUG_KERNEL || m
2276 help 2219 help
2277 Enable this to turn on 'do_div()' f 2220 Enable this to turn on 'do_div()' function test. This test is
2278 executed only once during system bo 2221 executed only once during system boot (so affects only boot time),
2279 or at module load time. 2222 or at module load time.
2280 2223
2281 If unsure, say N. 2224 If unsure, say N.
2282 2225
2283 config TEST_IOV_ITER 2226 config TEST_IOV_ITER
2284 tristate "Test iov_iter operation" if 2227 tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2285 depends on KUNIT 2228 depends on KUNIT
2286 depends on MMU 2229 depends on MMU
2287 default KUNIT_ALL_TESTS 2230 default KUNIT_ALL_TESTS
2288 help 2231 help
2289 Enable this to turn on testing of t 2232 Enable this to turn on testing of the operation of the I/O iterator
2290 (iov_iter). This test is executed o 2233 (iov_iter). This test is executed only once during system boot (so
2291 affects only boot time), or at modu 2234 affects only boot time), or at module load time.
2292 2235
2293 If unsure, say N. 2236 If unsure, say N.
2294 2237
2295 config KPROBES_SANITY_TEST 2238 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K 2239 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2297 depends on DEBUG_KERNEL 2240 depends on DEBUG_KERNEL
2298 depends on KPROBES 2241 depends on KPROBES
2299 depends on KUNIT 2242 depends on KUNIT
2300 select STACKTRACE if ARCH_CORRECT_STA 2243 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2301 default KUNIT_ALL_TESTS 2244 default KUNIT_ALL_TESTS
2302 help 2245 help
2303 This option provides for testing ba 2246 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 2247 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 2248 verified for functionality.
2306 2249
2307 Say N if you are unsure. 2250 Say N if you are unsure.
2308 2251
2309 config FPROBE_SANITY_TEST 2252 config FPROBE_SANITY_TEST
2310 bool "Self test for fprobe" 2253 bool "Self test for fprobe"
2311 depends on DEBUG_KERNEL 2254 depends on DEBUG_KERNEL
2312 depends on FPROBE 2255 depends on FPROBE
2313 depends on KUNIT=y 2256 depends on KUNIT=y
2314 help 2257 help
2315 This option will enable testing the 2258 This option will enable testing the fprobe when the system boot.
2316 A series of tests are made to verif 2259 A series of tests are made to verify that the fprobe is functioning
2317 properly. 2260 properly.
2318 2261
2319 Say N if you are unsure. 2262 Say N if you are unsure.
2320 2263
2321 config BACKTRACE_SELF_TEST 2264 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 2265 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 2266 depends on DEBUG_KERNEL
2324 help 2267 help
2325 This option provides a kernel modul 2268 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 2269 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 2270 for distributions or general kernels, but only for kernel
2328 developers working on architecture 2271 developers working on architecture code.
2329 2272
2330 Note that if you want to also test 2273 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 2274 have to enable STACKTRACE as well.
2332 2275
2333 Say N if you are unsure. 2276 Say N if you are unsure.
2334 2277
2335 config TEST_REF_TRACKER 2278 config TEST_REF_TRACKER
2336 tristate "Self test for reference tra 2279 tristate "Self test for reference tracker"
2337 depends on DEBUG_KERNEL && STACKTRACE 2280 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2338 select REF_TRACKER 2281 select REF_TRACKER
2339 help 2282 help
2340 This option provides a kernel modul 2283 This option provides a kernel module performing tests
2341 using reference tracker infrastruct 2284 using reference tracker infrastructure.
2342 2285
2343 Say N if you are unsure. 2286 Say N if you are unsure.
2344 2287
2345 config RBTREE_TEST 2288 config RBTREE_TEST
2346 tristate "Red-Black tree test" 2289 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 2290 depends on DEBUG_KERNEL
2348 help 2291 help
2349 A benchmark measuring the performan 2292 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 2293 Also includes rbtree invariant checks.
2351 2294
2352 config REED_SOLOMON_TEST 2295 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 2296 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 2297 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 2298 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 2299 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 2300 select REED_SOLOMON_DEC16
2358 help 2301 help
2359 This option enables the self-test f 2302 This option enables the self-test function of rslib at boot,
2360 or at module load time. 2303 or at module load time.
2361 2304
2362 If unsure, say N. 2305 If unsure, say N.
2363 2306
2364 config INTERVAL_TREE_TEST 2307 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 2308 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 2309 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 2310 select INTERVAL_TREE
2368 help 2311 help
2369 A benchmark measuring the performan 2312 A benchmark measuring the performance of the interval tree library
2370 2313
2371 config PERCPU_TEST 2314 config PERCPU_TEST
2372 tristate "Per cpu operations test" 2315 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 2316 depends on m && DEBUG_KERNEL
2374 help 2317 help
2375 Enable this option to build test mo 2318 Enable this option to build test module which validates per-cpu
2376 operations. 2319 operations.
2377 2320
2378 If unsure, say N. 2321 If unsure, say N.
2379 2322
2380 config ATOMIC64_SELFTEST 2323 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 2324 tristate "Perform an atomic64_t self-test"
2382 help 2325 help
2383 Enable this option to test the atom 2326 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 2327 at module load time.
2385 2328
2386 If unsure, say N. 2329 If unsure, say N.
2387 2330
2388 config ASYNC_RAID6_TEST 2331 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 2332 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 2333 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 2334 select ASYNC_MEMCPY
2392 help 2335 help
2393 This is a one-shot self test that p 2336 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 2337 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 2338 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 2339 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 2340 engine if one is available.
2398 2341
2399 If unsure, say N. 2342 If unsure, say N.
2400 2343
2401 config TEST_HEXDUMP 2344 config TEST_HEXDUMP
2402 tristate "Test functions located in t 2345 tristate "Test functions located in the hexdump module at runtime"
2403 2346
2404 config STRING_KUNIT_TEST !! 2347 config STRING_SELFTEST
2405 tristate "KUnit test string functions !! 2348 tristate "Test string functions at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 2349
2409 config STRING_HELPERS_KUNIT_TEST !! 2350 config TEST_STRING_HELPERS
2410 tristate "KUnit test string helpers a !! 2351 tristate "Test functions located in the string_helpers module at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 2352
2414 config TEST_KSTRTOX 2353 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 2354 tristate "Test kstrto*() family of functions at runtime"
2416 2355
2417 config TEST_PRINTF 2356 config TEST_PRINTF
2418 tristate "Test printf() family of fun 2357 tristate "Test printf() family of functions at runtime"
2419 2358
2420 config TEST_SCANF 2359 config TEST_SCANF
2421 tristate "Test scanf() family of func 2360 tristate "Test scanf() family of functions at runtime"
2422 2361
2423 config TEST_BITMAP 2362 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 2363 tristate "Test bitmap_*() family of functions at runtime"
2425 help 2364 help
2426 Enable this option to test the bitm 2365 Enable this option to test the bitmap functions at boot.
2427 2366
2428 If unsure, say N. 2367 If unsure, say N.
2429 2368
2430 config TEST_UUID 2369 config TEST_UUID
2431 tristate "Test functions located in t 2370 tristate "Test functions located in the uuid module at runtime"
2432 2371
2433 config TEST_XARRAY 2372 config TEST_XARRAY
2434 tristate "Test the XArray code at run 2373 tristate "Test the XArray code at runtime"
2435 2374
2436 config TEST_MAPLE_TREE 2375 config TEST_MAPLE_TREE
2437 tristate "Test the Maple Tree code at 2376 tristate "Test the Maple Tree code at runtime or module load"
2438 help 2377 help
2439 Enable this option to test the mapl 2378 Enable this option to test the maple tree code functions at boot, or
2440 when the module is loaded. Enable " 2379 when the module is loaded. Enable "Debug Maple Trees" will enable
2441 more verbose output on failures. 2380 more verbose output on failures.
2442 2381
2443 If unsure, say N. 2382 If unsure, say N.
2444 2383
2445 config TEST_RHASHTABLE 2384 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 2385 tristate "Perform selftest on resizable hash table"
2447 help 2386 help
2448 Enable this option to test the rhas 2387 Enable this option to test the rhashtable functions at boot.
2449 2388
2450 If unsure, say N. 2389 If unsure, say N.
2451 2390
2452 config TEST_IDA 2391 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 2392 tristate "Perform selftest on IDA functions"
2454 2393
2455 config TEST_PARMAN 2394 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 2395 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 2396 depends on PARMAN
2458 help 2397 help
2459 Enable this option to test priority 2398 Enable this option to test priority array manager on boot
2460 (or module load). 2399 (or module load).
2461 2400
2462 If unsure, say N. 2401 If unsure, say N.
2463 2402
2464 config TEST_IRQ_TIMINGS 2403 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 2404 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 2405 depends on IRQ_TIMINGS
2467 help 2406 help
2468 Enable this option to test the irq 2407 Enable this option to test the irq timings code on boot.
2469 2408
2470 If unsure, say N. 2409 If unsure, say N.
2471 2410
2472 config TEST_LKM 2411 config TEST_LKM
2473 tristate "Test module loading with 'h 2412 tristate "Test module loading with 'hello world' module"
2474 depends on m 2413 depends on m
2475 help 2414 help
2476 This builds the "test_module" modul 2415 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 2416 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 2417 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 2418 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 2419 and will not normally be loaded by the system unless explicitly
2481 requested by name. 2420 requested by name.
2482 2421
2483 If unsure, say N. 2422 If unsure, say N.
2484 2423
2485 config TEST_BITOPS 2424 config TEST_BITOPS
2486 tristate "Test module for compilation 2425 tristate "Test module for compilation of bitops operations"
>> 2426 depends on m
2487 help 2427 help
2488 This builds the "test_bitops" modul 2428 This builds the "test_bitops" module that is much like the
2489 TEST_LKM module except that it does 2429 TEST_LKM module except that it does a basic exercise of the
2490 set/clear_bit macros and get_count_ 2430 set/clear_bit macros and get_count_order/long to make sure there are
2491 no compiler warnings from C=1 spars 2431 no compiler warnings from C=1 sparse checker or -Wextra
2492 compilations. It has no dependencie 2432 compilations. It has no dependencies and doesn't run or load unless
2493 explicitly requested by name. for 2433 explicitly requested by name. for example: modprobe test_bitops.
2494 2434
2495 If unsure, say N. 2435 If unsure, say N.
2496 2436
2497 config TEST_VMALLOC 2437 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 2438 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 2439 default n
2500 depends on MMU 2440 depends on MMU
2501 depends on m 2441 depends on m
2502 help 2442 help
2503 This builds the "test_vmalloc" modu 2443 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 2444 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 2445 subsystem can be evaluated from performance and stability point
2506 of view. 2446 of view.
2507 2447
2508 If unsure, say N. 2448 If unsure, say N.
2509 2449
>> 2450 config TEST_USER_COPY
>> 2451 tristate "Test user/kernel boundary protections"
>> 2452 depends on m
>> 2453 help
>> 2454 This builds the "test_user_copy" module that runs sanity checks
>> 2455 on the copy_to/from_user infrastructure, making sure basic
>> 2456 user/kernel boundary testing is working. If it fails to load,
>> 2457 a regression has been detected in the user/kernel memory boundary
>> 2458 protections.
>> 2459
>> 2460 If unsure, say N.
>> 2461
2510 config TEST_BPF 2462 config TEST_BPF
2511 tristate "Test BPF filter functionali 2463 tristate "Test BPF filter functionality"
2512 depends on m && NET 2464 depends on m && NET
2513 help 2465 help
2514 This builds the "test_bpf" module t 2466 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 2467 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 2468 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 2469 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 2470 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 2471 verifier used by user space verifier testsuite.
2520 2472
2521 If unsure, say N. 2473 If unsure, say N.
2522 2474
2523 config TEST_BLACKHOLE_DEV 2475 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 2476 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 2477 depends on m && NET
2526 help 2478 help
2527 This builds the "test_blackhole_dev 2479 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 2480 data path through this blackhole netdev.
2529 2481
2530 If unsure, say N. 2482 If unsure, say N.
2531 2483
2532 config FIND_BIT_BENCHMARK 2484 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 2485 tristate "Test find_bit functions"
2534 help 2486 help
2535 This builds the "test_find_bit" mod 2487 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2488 functions performance.
2537 2489
2538 If unsure, say N. 2490 If unsure, say N.
2539 2491
2540 config TEST_FIRMWARE 2492 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2493 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2494 depends on FW_LOADER
2543 help 2495 help
2544 This builds the "test_firmware" mod 2496 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2497 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2498 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2499 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2500 userspace.
2549 2501
2550 If unsure, say N. 2502 If unsure, say N.
2551 2503
2552 config TEST_SYSCTL 2504 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2505 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2506 depends on PROC_SYSCTL
2555 help 2507 help
2556 This builds the "test_sysctl" modul 2508 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2509 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2510 production knobs which might alter system functionality.
2559 2511
2560 If unsure, say N. 2512 If unsure, say N.
2561 2513
2562 config BITFIELD_KUNIT 2514 config BITFIELD_KUNIT
2563 tristate "KUnit test bitfield functio 2515 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2564 depends on KUNIT 2516 depends on KUNIT
2565 default KUNIT_ALL_TESTS 2517 default KUNIT_ALL_TESTS
2566 help 2518 help
2567 Enable this option to test the bitf 2519 Enable this option to test the bitfield functions at boot.
2568 2520
2569 KUnit tests run during boot and out 2521 KUnit tests run during boot and output the results to the debug log
2570 in TAP format (http://testanything. 2522 in TAP format (http://testanything.org/). Only useful for kernel devs
2571 running the KUnit test harness, and 2523 running the KUnit test harness, and not intended for inclusion into a
2572 production build. 2524 production build.
2573 2525
2574 For more information on KUnit and u 2526 For more information on KUnit and unit tests in general please refer
2575 to the KUnit documentation in Docum 2527 to the KUnit documentation in Documentation/dev-tools/kunit/.
2576 2528
2577 If unsure, say N. 2529 If unsure, say N.
2578 2530
2579 config CHECKSUM_KUNIT 2531 config CHECKSUM_KUNIT
2580 tristate "KUnit test checksum functio 2532 tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2581 depends on KUNIT 2533 depends on KUNIT
2582 default KUNIT_ALL_TESTS 2534 default KUNIT_ALL_TESTS
2583 help 2535 help
2584 Enable this option to test the chec 2536 Enable this option to test the checksum functions at boot.
2585 2537
2586 KUnit tests run during boot and out 2538 KUnit tests run during boot and output the results to the debug log
2587 in TAP format (http://testanything. 2539 in TAP format (http://testanything.org/). Only useful for kernel devs
2588 running the KUnit test harness, and 2540 running the KUnit test harness, and not intended for inclusion into a
2589 production build. 2541 production build.
2590 2542
2591 For more information on KUnit and u 2543 For more information on KUnit and unit tests in general please refer
2592 to the KUnit documentation in Docum 2544 to the KUnit documentation in Documentation/dev-tools/kunit/.
2593 2545
2594 If unsure, say N. 2546 If unsure, say N.
2595 2547
2596 config HASH_KUNIT_TEST 2548 config HASH_KUNIT_TEST
2597 tristate "KUnit Test for integer hash 2549 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2598 depends on KUNIT 2550 depends on KUNIT
2599 default KUNIT_ALL_TESTS 2551 default KUNIT_ALL_TESTS
2600 help 2552 help
2601 Enable this option to test the kern 2553 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2602 integer (<linux/hash.h>) hash funct 2554 integer (<linux/hash.h>) hash functions on boot.
2603 2555
2604 KUnit tests run during boot and out 2556 KUnit tests run during boot and output the results to the debug log
2605 in TAP format (https://testanything 2557 in TAP format (https://testanything.org/). Only useful for kernel devs
2606 running the KUnit test harness, and 2558 running the KUnit test harness, and not intended for inclusion into a
2607 production build. 2559 production build.
2608 2560
2609 For more information on KUnit and u 2561 For more information on KUnit and unit tests in general please refer
2610 to the KUnit documentation in Docum 2562 to the KUnit documentation in Documentation/dev-tools/kunit/.
2611 2563
2612 This is intended to help people wri 2564 This is intended to help people writing architecture-specific
2613 optimized versions. If unsure, say 2565 optimized versions. If unsure, say N.
2614 2566
2615 config RESOURCE_KUNIT_TEST 2567 config RESOURCE_KUNIT_TEST
2616 tristate "KUnit test for resource API 2568 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2617 depends on KUNIT 2569 depends on KUNIT
2618 default KUNIT_ALL_TESTS 2570 default KUNIT_ALL_TESTS
2619 help 2571 help
2620 This builds the resource API unit t 2572 This builds the resource API unit test.
2621 Tests the logic of API provided by 2573 Tests the logic of API provided by resource.c and ioport.h.
2622 For more information on KUnit and u 2574 For more information on KUnit and unit tests in general please refer
2623 to the KUnit documentation in Docum 2575 to the KUnit documentation in Documentation/dev-tools/kunit/.
2624 2576
2625 If unsure, say N. 2577 If unsure, say N.
2626 2578
2627 config SYSCTL_KUNIT_TEST 2579 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! 2580 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629 depends on KUNIT 2581 depends on KUNIT
2630 default KUNIT_ALL_TESTS 2582 default KUNIT_ALL_TESTS
2631 help 2583 help
2632 This builds the proc sysctl unit te 2584 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2585 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2586 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2587 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2588
2637 If unsure, say N. 2589 If unsure, say N.
2638 2590
2639 config LIST_KUNIT_TEST 2591 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke 2592 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641 depends on KUNIT 2593 depends on KUNIT
2642 default KUNIT_ALL_TESTS 2594 default KUNIT_ALL_TESTS
2643 help 2595 help
2644 This builds the linked list KUnit t 2596 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2597 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2598 and associated macros.
2647 2599
2648 KUnit tests run during boot and out 2600 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything 2601 in TAP format (https://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2602 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2603 production build.
2652 2604
2653 For more information on KUnit and u 2605 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2606 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2607
2656 If unsure, say N. 2608 If unsure, say N.
2657 2609
2658 config HASHTABLE_KUNIT_TEST 2610 config HASHTABLE_KUNIT_TEST
2659 tristate "KUnit Test for Kernel Hasht 2611 tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2660 depends on KUNIT 2612 depends on KUNIT
2661 default KUNIT_ALL_TESTS 2613 default KUNIT_ALL_TESTS
2662 help 2614 help
2663 This builds the hashtable KUnit tes 2615 This builds the hashtable KUnit test suite.
2664 It tests the basic functionality of 2616 It tests the basic functionality of the API defined in
2665 include/linux/hashtable.h. For more 2617 include/linux/hashtable.h. For more information on KUnit and
2666 unit tests in general please refer 2618 unit tests in general please refer to the KUnit documentation
2667 in Documentation/dev-tools/kunit/. 2619 in Documentation/dev-tools/kunit/.
2668 2620
2669 If unsure, say N. 2621 If unsure, say N.
2670 2622
2671 config LINEAR_RANGES_TEST 2623 config LINEAR_RANGES_TEST
2672 tristate "KUnit test for linear_range 2624 tristate "KUnit test for linear_ranges"
2673 depends on KUNIT 2625 depends on KUNIT
2674 select LINEAR_RANGES 2626 select LINEAR_RANGES
2675 help 2627 help
2676 This builds the linear_ranges unit 2628 This builds the linear_ranges unit test, which runs on boot.
2677 Tests the linear_ranges logic corre 2629 Tests the linear_ranges logic correctness.
2678 For more information on KUnit and u 2630 For more information on KUnit and unit tests in general please refer
2679 to the KUnit documentation in Docum 2631 to the KUnit documentation in Documentation/dev-tools/kunit/.
2680 2632
2681 If unsure, say N. 2633 If unsure, say N.
2682 2634
2683 config CMDLINE_KUNIT_TEST 2635 config CMDLINE_KUNIT_TEST
2684 tristate "KUnit test for cmdline API" 2636 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2685 depends on KUNIT 2637 depends on KUNIT
2686 default KUNIT_ALL_TESTS 2638 default KUNIT_ALL_TESTS
2687 help 2639 help
2688 This builds the cmdline API unit te 2640 This builds the cmdline API unit test.
2689 Tests the logic of API provided by 2641 Tests the logic of API provided by cmdline.c.
2690 For more information on KUnit and u 2642 For more information on KUnit and unit tests in general please refer
2691 to the KUnit documentation in Docum 2643 to the KUnit documentation in Documentation/dev-tools/kunit/.
2692 2644
2693 If unsure, say N. 2645 If unsure, say N.
2694 2646
2695 config BITS_TEST 2647 config BITS_TEST
2696 tristate "KUnit test for bits.h" if ! 2648 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2697 depends on KUNIT 2649 depends on KUNIT
2698 default KUNIT_ALL_TESTS 2650 default KUNIT_ALL_TESTS
2699 help 2651 help
2700 This builds the bits unit test. 2652 This builds the bits unit test.
2701 Tests the logic of macros defined i 2653 Tests the logic of macros defined in bits.h.
2702 For more information on KUnit and u 2654 For more information on KUnit and unit tests in general please refer
2703 to the KUnit documentation in Docum 2655 to the KUnit documentation in Documentation/dev-tools/kunit/.
2704 2656
2705 If unsure, say N. 2657 If unsure, say N.
2706 2658
2707 config SLUB_KUNIT_TEST 2659 config SLUB_KUNIT_TEST
2708 tristate "KUnit test for SLUB cache e 2660 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2709 depends on SLUB_DEBUG && KUNIT 2661 depends on SLUB_DEBUG && KUNIT
2710 default KUNIT_ALL_TESTS 2662 default KUNIT_ALL_TESTS
2711 help 2663 help
2712 This builds SLUB allocator unit tes 2664 This builds SLUB allocator unit test.
2713 Tests SLUB cache debugging function 2665 Tests SLUB cache debugging functionality.
2714 For more information on KUnit and u 2666 For more information on KUnit and unit tests in general please refer
2715 to the KUnit documentation in Docum 2667 to the KUnit documentation in Documentation/dev-tools/kunit/.
2716 2668
2717 If unsure, say N. 2669 If unsure, say N.
2718 2670
2719 config RATIONAL_KUNIT_TEST 2671 config RATIONAL_KUNIT_TEST
2720 tristate "KUnit test for rational.c" 2672 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2721 depends on KUNIT && RATIONAL 2673 depends on KUNIT && RATIONAL
2722 default KUNIT_ALL_TESTS 2674 default KUNIT_ALL_TESTS
2723 help 2675 help
2724 This builds the rational math unit 2676 This builds the rational math unit test.
2725 For more information on KUnit and u 2677 For more information on KUnit and unit tests in general please refer
2726 to the KUnit documentation in Docum 2678 to the KUnit documentation in Documentation/dev-tools/kunit/.
2727 2679
2728 If unsure, say N. 2680 If unsure, say N.
2729 2681
2730 config MEMCPY_KUNIT_TEST 2682 config MEMCPY_KUNIT_TEST
2731 tristate "Test memcpy(), memmove(), a 2683 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2732 depends on KUNIT 2684 depends on KUNIT
2733 default KUNIT_ALL_TESTS 2685 default KUNIT_ALL_TESTS
2734 help 2686 help
2735 Builds unit tests for memcpy(), mem 2687 Builds unit tests for memcpy(), memmove(), and memset() functions.
2736 For more information on KUnit and u 2688 For more information on KUnit and unit tests in general please refer
2737 to the KUnit documentation in Docum 2689 to the KUnit documentation in Documentation/dev-tools/kunit/.
2738 2690
2739 If unsure, say N. 2691 If unsure, say N.
2740 2692
>> 2693 config MEMCPY_SLOW_KUNIT_TEST
>> 2694 bool "Include exhaustive memcpy tests"
>> 2695 depends on MEMCPY_KUNIT_TEST
>> 2696 default y
>> 2697 help
>> 2698 Some memcpy tests are quite exhaustive in checking for overlaps
>> 2699 and bit ranges. These can be very slow, so they are split out
>> 2700 as a separate config, in case they need to be disabled.
>> 2701
>> 2702 Note this config option will be replaced by the use of KUnit test
>> 2703 attributes.
>> 2704
2741 config IS_SIGNED_TYPE_KUNIT_TEST 2705 config IS_SIGNED_TYPE_KUNIT_TEST
2742 tristate "Test is_signed_type() macro 2706 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2743 depends on KUNIT 2707 depends on KUNIT
2744 default KUNIT_ALL_TESTS 2708 default KUNIT_ALL_TESTS
2745 help 2709 help
2746 Builds unit tests for the is_signed 2710 Builds unit tests for the is_signed_type() macro.
2747 2711
2748 For more information on KUnit and u 2712 For more information on KUnit and unit tests in general please refer
2749 to the KUnit documentation in Docum 2713 to the KUnit documentation in Documentation/dev-tools/kunit/.
2750 2714
2751 If unsure, say N. 2715 If unsure, say N.
2752 2716
2753 config OVERFLOW_KUNIT_TEST 2717 config OVERFLOW_KUNIT_TEST
2754 tristate "Test check_*_overflow() fun 2718 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2755 depends on KUNIT 2719 depends on KUNIT
2756 default KUNIT_ALL_TESTS 2720 default KUNIT_ALL_TESTS
2757 help 2721 help
2758 Builds unit tests for the check_*_o 2722 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2759 related functions. 2723 related functions.
2760 2724
2761 For more information on KUnit and u 2725 For more information on KUnit and unit tests in general please refer
2762 to the KUnit documentation in Docum 2726 to the KUnit documentation in Documentation/dev-tools/kunit/.
2763 2727
2764 If unsure, say N. 2728 If unsure, say N.
2765 2729
2766 config STACKINIT_KUNIT_TEST 2730 config STACKINIT_KUNIT_TEST
2767 tristate "Test level of stack variabl 2731 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2768 depends on KUNIT 2732 depends on KUNIT
2769 default KUNIT_ALL_TESTS 2733 default KUNIT_ALL_TESTS
2770 help 2734 help
2771 Test if the kernel is zero-initiali 2735 Test if the kernel is zero-initializing stack variables and
2772 padding. Coverage is controlled by 2736 padding. Coverage is controlled by compiler flags,
2773 CONFIG_INIT_STACK_ALL_PATTERN, CONF 2737 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2774 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFI 2738 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2775 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYR 2739 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2776 2740
2777 config FORTIFY_KUNIT_TEST 2741 config FORTIFY_KUNIT_TEST
2778 tristate "Test fortified str*() and m 2742 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2779 depends on KUNIT !! 2743 depends on KUNIT && FORTIFY_SOURCE
2780 default KUNIT_ALL_TESTS 2744 default KUNIT_ALL_TESTS
2781 help 2745 help
2782 Builds unit tests for checking inte 2746 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2783 by the str*() and mem*() family of 2747 by the str*() and mem*() family of functions. For testing runtime
2784 traps of FORTIFY_SOURCE, see LKDTM' 2748 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2785 2749
2786 config HW_BREAKPOINT_KUNIT_TEST 2750 config HW_BREAKPOINT_KUNIT_TEST
2787 bool "Test hw_breakpoint constraints 2751 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2788 depends on HAVE_HW_BREAKPOINT 2752 depends on HAVE_HW_BREAKPOINT
2789 depends on KUNIT=y 2753 depends on KUNIT=y
2790 default KUNIT_ALL_TESTS 2754 default KUNIT_ALL_TESTS
2791 help 2755 help
2792 Tests for hw_breakpoint constraints 2756 Tests for hw_breakpoint constraints accounting.
2793 2757
2794 If unsure, say N. 2758 If unsure, say N.
2795 2759
>> 2760 config STRCAT_KUNIT_TEST
>> 2761 tristate "Test strcat() family of functions at runtime" if !KUNIT_ALL_TESTS
>> 2762 depends on KUNIT
>> 2763 default KUNIT_ALL_TESTS
>> 2764
>> 2765 config STRSCPY_KUNIT_TEST
>> 2766 tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
>> 2767 depends on KUNIT
>> 2768 default KUNIT_ALL_TESTS
>> 2769
2796 config SIPHASH_KUNIT_TEST 2770 config SIPHASH_KUNIT_TEST
2797 tristate "Perform selftest on siphash 2771 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2798 depends on KUNIT 2772 depends on KUNIT
2799 default KUNIT_ALL_TESTS 2773 default KUNIT_ALL_TESTS
2800 help 2774 help
2801 Enable this option to test the kern 2775 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2802 functions on boot (or module load). 2776 functions on boot (or module load).
2803 2777
2804 This is intended to help people wri 2778 This is intended to help people writing architecture-specific
2805 optimized versions. If unsure, say 2779 optimized versions. If unsure, say N.
2806 2780
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 2781 config TEST_UDELAY
2817 tristate "udelay test driver" 2782 tristate "udelay test driver"
2818 help 2783 help
2819 This builds the "udelay_test" modul 2784 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2785 that udelay() is working properly.
2821 2786
2822 If unsure, say N. 2787 If unsure, say N.
2823 2788
2824 config TEST_STATIC_KEYS 2789 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2790 tristate "Test static keys"
2826 depends on m 2791 depends on m
2827 help 2792 help
2828 Test the static key interfaces. 2793 Test the static key interfaces.
2829 2794
2830 If unsure, say N. 2795 If unsure, say N.
2831 2796
2832 config TEST_DYNAMIC_DEBUG 2797 config TEST_DYNAMIC_DEBUG
2833 tristate "Test DYNAMIC_DEBUG" 2798 tristate "Test DYNAMIC_DEBUG"
2834 depends on DYNAMIC_DEBUG 2799 depends on DYNAMIC_DEBUG
2835 help 2800 help
2836 This module registers a tracer call 2801 This module registers a tracer callback to count enabled
2837 pr_debugs in a 'do_debugging' funct 2802 pr_debugs in a 'do_debugging' function, then alters their
2838 enablements, calls the function, an 2803 enablements, calls the function, and compares counts.
2839 2804
2840 If unsure, say N. 2805 If unsure, say N.
2841 2806
2842 config TEST_KMOD 2807 config TEST_KMOD
2843 tristate "kmod stress tester" 2808 tristate "kmod stress tester"
2844 depends on m 2809 depends on m
2845 depends on NETDEVICES && NET_CORE && 2810 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2811 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB 2812 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2848 select TEST_LKM 2813 select TEST_LKM
2849 select XFS_FS 2814 select XFS_FS
2850 select TUN 2815 select TUN
2851 select BTRFS_FS 2816 select BTRFS_FS
2852 help 2817 help
2853 Test the kernel's module loading me 2818 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2819 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2820 This test provides a series of tests against kmod.
2856 2821
2857 Although technically you can either 2822 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2823 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2824 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2825 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2826 module load requests, ultimately this could be fatal.
2862 2827
2863 To run tests run: 2828 To run tests run:
2864 2829
2865 tools/testing/selftests/kmod/kmod.s 2830 tools/testing/selftests/kmod/kmod.sh --help
2866 2831
2867 If unsure, say N. 2832 If unsure, say N.
2868 2833
2869 config TEST_DEBUG_VIRTUAL 2834 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2835 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2836 depends on DEBUG_VIRTUAL
2872 help 2837 help
2873 Test the kernel's ability to detect 2838 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2839 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2840 kernel's virtual address map.
2876 2841
2877 If unsure, say N. 2842 If unsure, say N.
2878 2843
2879 config TEST_MEMCAT_P 2844 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2845 tristate "Test memcat_p() helper function"
2881 help 2846 help
2882 Test the memcat_p() helper for corr 2847 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2848 pointer arrays together.
2884 2849
2885 If unsure, say N. 2850 If unsure, say N.
2886 2851
>> 2852 config TEST_LIVEPATCH
>> 2853 tristate "Test livepatching"
>> 2854 default n
>> 2855 depends on DYNAMIC_DEBUG
>> 2856 depends on LIVEPATCH
>> 2857 depends on m
>> 2858 help
>> 2859 Test kernel livepatching features for correctness. The tests will
>> 2860 load test modules that will be livepatched in various scenarios.
>> 2861
>> 2862 To run all the livepatching tests:
>> 2863
>> 2864 make -C tools/testing/selftests TARGETS=livepatch run_tests
>> 2865
>> 2866 Alternatively, individual tests may be invoked:
>> 2867
>> 2868 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2869 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2870 tools/testing/selftests/livepatch/test-shadow-vars.sh
>> 2871
>> 2872 If unsure, say N.
>> 2873
2887 config TEST_OBJAGG 2874 config TEST_OBJAGG
2888 tristate "Perform selftest on object 2875 tristate "Perform selftest on object aggreration manager"
2889 default n 2876 default n
2890 depends on OBJAGG 2877 depends on OBJAGG
2891 help 2878 help
2892 Enable this option to test object a 2879 Enable this option to test object aggregation manager on boot
2893 (or module load). 2880 (or module load).
2894 2881
2895 config TEST_MEMINIT 2882 config TEST_MEMINIT
2896 tristate "Test heap/page initializati 2883 tristate "Test heap/page initialization"
2897 help 2884 help
2898 Test if the kernel is zero-initiali 2885 Test if the kernel is zero-initializing heap and page allocations.
2899 This can be useful to test init_on_ 2886 This can be useful to test init_on_alloc and init_on_free features.
2900 2887
2901 If unsure, say N. 2888 If unsure, say N.
2902 2889
2903 config TEST_HMM 2890 config TEST_HMM
2904 tristate "Test HMM (Heterogeneous Mem 2891 tristate "Test HMM (Heterogeneous Memory Management)"
2905 depends on TRANSPARENT_HUGEPAGE 2892 depends on TRANSPARENT_HUGEPAGE
2906 depends on DEVICE_PRIVATE 2893 depends on DEVICE_PRIVATE
2907 select HMM_MIRROR 2894 select HMM_MIRROR
2908 select MMU_NOTIFIER 2895 select MMU_NOTIFIER
2909 help 2896 help
2910 This is a pseudo device driver sole 2897 This is a pseudo device driver solely for testing HMM.
2911 Say M here if you want to build the 2898 Say M here if you want to build the HMM test module.
2912 Doing so will allow you to run tool 2899 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913 2900
2914 If unsure, say N. 2901 If unsure, say N.
2915 2902
2916 config TEST_FREE_PAGES 2903 config TEST_FREE_PAGES
2917 tristate "Test freeing pages" 2904 tristate "Test freeing pages"
2918 help 2905 help
2919 Test that a memory leak does not oc 2906 Test that a memory leak does not occur due to a race between
2920 freeing a block of pages and a spec 2907 freeing a block of pages and a speculative page reference.
2921 Loading this module is safe if your 2908 Loading this module is safe if your kernel has the bug fixed.
2922 If the bug is not fixed, it will le 2909 If the bug is not fixed, it will leak gigabytes of memory and
2923 probably OOM your system. 2910 probably OOM your system.
2924 2911
2925 config TEST_FPU 2912 config TEST_FPU
2926 tristate "Test floating point operati 2913 tristate "Test floating point operations in kernel space"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2914 depends on X86 && !KCOV_INSTRUMENT_ALL
2928 help 2915 help
2929 Enable this option to add /sys/kern 2916 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930 which will trigger a sequence of fl 2917 which will trigger a sequence of floating point operations. This is used
2931 for self-testing floating point con 2918 for self-testing floating point control register setting in
2932 kernel_fpu_begin(). 2919 kernel_fpu_begin().
2933 2920
2934 If unsure, say N. 2921 If unsure, say N.
2935 2922
2936 config TEST_CLOCKSOURCE_WATCHDOG 2923 config TEST_CLOCKSOURCE_WATCHDOG
2937 tristate "Test clocksource watchdog i 2924 tristate "Test clocksource watchdog in kernel space"
2938 depends on CLOCKSOURCE_WATCHDOG 2925 depends on CLOCKSOURCE_WATCHDOG
2939 help 2926 help
2940 Enable this option to create a kern 2927 Enable this option to create a kernel module that will trigger
2941 a test of the clocksource watchdog. 2928 a test of the clocksource watchdog. This module may be loaded
2942 via modprobe or insmod in which cas 2929 via modprobe or insmod in which case it will run upon being
2943 loaded, or it may be built in, in w 2930 loaded, or it may be built in, in which case it will run
2944 shortly after boot. 2931 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 2932
2957 If unsure, say N. 2933 If unsure, say N.
2958 2934
2959 endif # RUNTIME_TESTING_MENU 2935 endif # RUNTIME_TESTING_MENU
2960 2936
2961 config ARCH_USE_MEMTEST 2937 config ARCH_USE_MEMTEST
2962 bool 2938 bool
2963 help 2939 help
2964 An architecture should select this 2940 An architecture should select this when it uses early_memtest()
2965 during boot process. 2941 during boot process.
2966 2942
2967 config MEMTEST 2943 config MEMTEST
2968 bool "Memtest" 2944 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST 2945 depends on ARCH_USE_MEMTEST
2970 help 2946 help
2971 This option adds a kernel parameter 2947 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. 2948 to be set and executed.
2973 memtest=0, mean disabled; -- 2949 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2950 memtest=1, mean do 1 test pattern;
2975 ... 2951 ...
2976 memtest=17, mean do 17 test p 2952 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2953 If you are unsure how to answer this question, answer N.
2978 2954
2979 2955
2980 2956
2981 config HYPERV_TESTING 2957 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2958 bool "Microsoft Hyper-V driver testing"
2983 default n 2959 default n
2984 depends on HYPERV && DEBUG_FS 2960 depends on HYPERV && DEBUG_FS
2985 help 2961 help
2986 Select this option to enable Hyper- 2962 Select this option to enable Hyper-V vmbus testing.
2987 2963
2988 endmenu # "Kernel Testing and Coverage" 2964 endmenu # "Kernel Testing and Coverage"
2989 2965
2990 menu "Rust hacking" 2966 menu "Rust hacking"
2991 2967
2992 config RUST_DEBUG_ASSERTIONS 2968 config RUST_DEBUG_ASSERTIONS
2993 bool "Debug assertions" 2969 bool "Debug assertions"
2994 depends on RUST 2970 depends on RUST
2995 help 2971 help
2996 Enables rustc's `-Cdebug-assertions 2972 Enables rustc's `-Cdebug-assertions` codegen option.
2997 2973
2998 This flag lets you turn `cfg(debug_ 2974 This flag lets you turn `cfg(debug_assertions)` conditional
2999 compilation on or off. This can be 2975 compilation on or off. This can be used to enable extra debugging
3000 code in development but not in prod 2976 code in development but not in production. For example, it controls
3001 the behavior of the standard librar 2977 the behavior of the standard library's `debug_assert!` macro.
3002 2978
3003 Note that this will apply to all Ru 2979 Note that this will apply to all Rust code, including `core`.
3004 2980
3005 If unsure, say N. 2981 If unsure, say N.
3006 2982
3007 config RUST_OVERFLOW_CHECKS 2983 config RUST_OVERFLOW_CHECKS
3008 bool "Overflow checks" 2984 bool "Overflow checks"
3009 default y 2985 default y
3010 depends on RUST 2986 depends on RUST
3011 help 2987 help
3012 Enables rustc's `-Coverflow-checks` 2988 Enables rustc's `-Coverflow-checks` codegen option.
3013 2989
3014 This flag allows you to control the 2990 This flag allows you to control the behavior of runtime integer
3015 overflow. When overflow-checks are 2991 overflow. When overflow-checks are enabled, a Rust panic will occur
3016 on overflow. 2992 on overflow.
3017 2993
3018 Note that this will apply to all Ru 2994 Note that this will apply to all Rust code, including `core`.
3019 2995
3020 If unsure, say Y. 2996 If unsure, say Y.
3021 2997
3022 config RUST_BUILD_ASSERT_ALLOW 2998 config RUST_BUILD_ASSERT_ALLOW
3023 bool "Allow unoptimized build-time as 2999 bool "Allow unoptimized build-time assertions"
3024 depends on RUST 3000 depends on RUST
3025 help 3001 help
3026 Controls how are `build_error!` and 3002 Controls how are `build_error!` and `build_assert!` handled during build.
3027 3003
3028 If calls to them exist in the binar 3004 If calls to them exist in the binary, it may indicate a violated invariant
3029 or that the optimizer failed to ver 3005 or that the optimizer failed to verify the invariant during compilation.
3030 3006
3031 This should not happen, thus by def 3007 This should not happen, thus by default the build is aborted. However,
3032 as an escape hatch, you can choose 3008 as an escape hatch, you can choose Y here to ignore them during build
3033 and let the check be carried at run 3009 and let the check be carried at runtime (with `panic!` being called if
3034 the check fails). 3010 the check fails).
3035 3011
3036 If unsure, say N. 3012 If unsure, say N.
3037 3013
3038 config RUST_KERNEL_DOCTESTS 3014 config RUST_KERNEL_DOCTESTS
3039 bool "Doctests for the `kernel` crate 3015 bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3040 depends on RUST && KUNIT=y 3016 depends on RUST && KUNIT=y
3041 default KUNIT_ALL_TESTS 3017 default KUNIT_ALL_TESTS
3042 help 3018 help
3043 This builds the documentation tests 3019 This builds the documentation tests of the `kernel` crate
3044 as KUnit tests. 3020 as KUnit tests.
3045 3021
3046 For more information on KUnit and u 3022 For more information on KUnit and unit tests in general,
3047 please refer to the KUnit documenta 3023 please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3048 3024
3049 If unsure, say N. 3025 If unsure, say N.
3050 3026
3051 endmenu # "Rust" 3027 endmenu # "Rust"
3052 3028
3053 endmenu # Kernel hacking 3029 endmenu # Kernel hacking
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