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Thomas Gleixnerec8f24b2019-05-19 13:07:45 +01001# SPDX-License-Identifier: GPL-2.0-only
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002menu "Kernel hacking"
3
Dave Hansen604ff0d2013-07-01 13:04:49 -07004menu "printk and dmesg options"
Linus Torvalds1da177e2005-04-16 15:20:36 -07005
6config PRINTK_TIME
7 bool "Show timing information on printks"
Randy Dunlapd3b8b6e2006-12-06 20:36:38 -08008 depends on PRINTK
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 help
Kay Sievers649e6ee2012-05-10 04:30:45 +020010 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -020019 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Tetsuo Handa15ff2062018-12-18 06:05:04 +090021config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
Olof Johanssona8cfdc62016-12-12 16:45:56 -080038config CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
40 range 1 15
41 default "7"
42 help
43 Default loglevel to determine what will be printed on the console.
44
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
48
Borislav Petkov50f4d9b2016-12-19 16:23:15 -080049 Note: This does not affect the log level of un-prefixed printk()
Olof Johanssona8cfdc62016-12-12 16:45:56 -080050 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
51 option.
52
Hans de Goede22eceb82018-06-19 13:57:26 +020053config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
55 range 1 15
56 default "4"
57 help
58 loglevel to use when "quiet" is passed on the kernel commandline.
59
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
63
Alex Elder42a9dc02014-08-06 16:09:01 -070064config MESSAGE_LOGLEVEL_DEFAULT
Mandeep Singh Baines5af5bcb2011-03-22 16:34:23 -070065 int "Default message log level (1-7)"
66 range 1 7
67 default "4"
68 help
69 Default log level for printk statements with no specified priority.
70
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
73 priority.
74
Olof Johanssona8cfdc62016-12-12 16:45:56 -080075 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
78
Dave Hansen604ff0d2013-07-01 13:04:49 -070079config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
82 help
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
86 using "boot_delay=N".
87
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
96
97config DYNAMIC_DEBUG
98 bool "Enable dynamic printk() support"
99 default n
100 depends on PRINTK
Greg Kroah-Hartman239a5792020-02-10 13:11:42 -0800101 depends on (DEBUG_FS || PROC_FS)
Orson Zhaiceabef72020-06-07 21:40:14 -0700102 select DYNAMIC_DEBUG_CORE
Dave Hansen604ff0d2013-07-01 13:04:49 -0700103 help
104
105 Compiles debug level messages into the kernel, which would not
106 otherwise be available at runtime. These messages can then be
107 enabled/disabled based on various levels of scope - per source file,
108 function, module, format string, and line number. This mechanism
109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
110 enlarges the kernel text size by about 2%.
111
112 If a source file is compiled with DEBUG flag set, any
113 pr_debug() calls in it are enabled by default, but can be
114 disabled at runtime as below. Note that DEBUG flag is
115 turned on by many CONFIG_*DEBUG* options.
116
117 Usage:
118
119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
Greg Kroah-Hartman239a5792020-02-10 13:11:42 -0800120 which is contained in the 'debugfs' filesystem or procfs.
121 Thus, the debugfs or procfs filesystem must first be mounted before
122 making use of this feature.
Dave Hansen604ff0d2013-07-01 13:04:49 -0700123 We refer the control file as: <debugfs>/dynamic_debug/control. This
124 file contains a list of the debug statements that can be enabled. The
125 format for each line of the file is:
126
127 filename:lineno [module]function flags format
128
129 filename : source file of the debug statement
130 lineno : line number of the debug statement
131 module : module that contains the debug statement
132 function : function that contains the debug statement
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800133 flags : '=p' means the line is turned 'on' for printing
134 format : the format used for the debug statement
Dave Hansen604ff0d2013-07-01 13:04:49 -0700135
136 From a live system:
137
138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
139 # filename:lineno [module]function flags format
140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
143
144 Example usage:
145
146 // enable the message at line 1603 of file svcsock.c
147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
148 <debugfs>/dynamic_debug/control
149
150 // enable all the messages in file svcsock.c
151 nullarbor:~ # echo -n 'file svcsock.c +p' >
152 <debugfs>/dynamic_debug/control
153
154 // enable all the messages in the NFS server module
155 nullarbor:~ # echo -n 'module nfsd +p' >
156 <debugfs>/dynamic_debug/control
157
158 // enable all 12 messages in the function svc_process()
159 nullarbor:~ # echo -n 'func svc_process +p' >
160 <debugfs>/dynamic_debug/control
161
162 // disable all 12 messages in the function svc_process()
163 nullarbor:~ # echo -n 'func svc_process -p' >
164 <debugfs>/dynamic_debug/control
165
Hans Holmbergf8998c22017-03-16 09:37:32 +0100166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
167 information.
Dave Hansen604ff0d2013-07-01 13:04:49 -0700168
Orson Zhaiceabef72020-06-07 21:40:14 -0700169config DYNAMIC_DEBUG_CORE
170 bool "Enable core function of dynamic debug support"
171 depends on PRINTK
172 depends on (DEBUG_FS || PROC_FS)
173 help
174 Enable core functional support of dynamic debug. It is useful
175 when you want to tie dynamic debug to your kernel modules with
176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
177 the case of embedded system where the kernel image size is
178 sensitive for people.
179
Rasmus Villemoes57f56772019-10-15 21:07:05 +0200180config SYMBOLIC_ERRNAME
181 bool "Support symbolic error names in printf"
182 default y if PRINTK
183 help
184 If you say Y here, the kernel's printf implementation will
185 be able to print symbolic error names such as ENOSPC instead
186 of the number 28. It makes the kernel image slightly larger
187 (about 3KB), but can make the kernel logs easier to read.
188
Changbin Du2b05bb72019-12-06 17:04:03 -0800189config DEBUG_BUGVERBOSE
190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
192 default y
193 help
194 Say Y here to make BUG() panics output the file name and line number
195 of the BUG call as well as the EIP and oops trace. This aids
196 debugging but costs about 70-100K of memory.
197
Dave Hansen604ff0d2013-07-01 13:04:49 -0700198endmenu # "printk and dmesg options"
199
Dave Hansen6dfc0662013-07-01 13:04:46 -0700200menu "Compile-time checks and compiler options"
201
202config DEBUG_INFO
203 bool "Compile the kernel with debug info"
Linus Torvalds12b13832014-02-04 12:20:01 -0800204 depends on DEBUG_KERNEL && !COMPILE_TEST
Dave Hansen6dfc0662013-07-01 13:04:46 -0700205 help
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800206 If you say Y here the resulting kernel image will include
Dave Hansen6dfc0662013-07-01 13:04:46 -0700207 debugging info resulting in a larger kernel image.
208 This adds debug symbols to the kernel and modules (gcc -g), and
209 is needed if you intend to use kernel crashdump or binary object
210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
211 Say Y here only if you plan to debug the kernel.
212
213 If unsure, say N.
214
215config DEBUG_INFO_REDUCED
216 bool "Reduce debugging information"
217 depends on DEBUG_INFO
218 help
219 If you say Y here gcc is instructed to generate less debugging
220 information for structure types. This means that tools that
221 need full debugging information (like kgdb or systemtap) won't
222 be happy. But if you merely need debugging information to
223 resolve line numbers there is no loss. Advantage is that
224 build directory object sizes shrink dramatically over a full
225 DEBUG_INFO build and compile times are reduced too.
226 Only works with newer gcc versions.
227
Nick Desaulniers10e68b022020-05-26 10:18:29 -0700228config DEBUG_INFO_COMPRESSED
229 bool "Compressed debugging information"
230 depends on DEBUG_INFO
231 depends on $(cc-option,-gz=zlib)
Nick Desaulniers10e68b022020-05-26 10:18:29 -0700232 depends on $(ld-option,--compress-debug-sections=zlib)
233 help
234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
235 5.0+, binutils 2.26+, and zlib.
236
237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
238 size of their debug .deb packages with this config set, due to the
239 debug info being compressed with zlib, then the object files being
240 recompressed with a different compression scheme. But this is still
241 preferable to setting $KDEB_COMPRESS to "none" which would be even
242 larger.
243
Andi Kleen866ced92014-07-30 20:50:18 +0200244config DEBUG_INFO_SPLIT
245 bool "Produce split debuginfo in .dwo files"
Arnd Bergmanna687a532018-03-07 23:30:54 +0100246 depends on DEBUG_INFO
Masahiro Yamada9d937442019-02-22 16:56:09 +0900247 depends on $(cc-option,-gsplit-dwarf)
Andi Kleen866ced92014-07-30 20:50:18 +0200248 help
249 Generate debug info into separate .dwo files. This significantly
250 reduces the build directory size for builds with DEBUG_INFO,
251 because it stores the information only once on disk in .dwo
252 files instead of multiple times in object files and executables.
253 In addition the debug information is also compressed.
254
255 Requires recent gcc (4.7+) and recent gdb/binutils.
256 Any tool that packages or reads debug information would need
257 to know about the .dwo files and include them.
258 Incompatible with older versions of ccache.
259
Andi Kleenbfaf2dd2014-07-30 20:50:19 +0200260config DEBUG_INFO_DWARF4
261 bool "Generate dwarf4 debuginfo"
262 depends on DEBUG_INFO
Masahiro Yamada9d937442019-02-22 16:56:09 +0900263 depends on $(cc-option,-gdwarf-4)
Andi Kleenbfaf2dd2014-07-30 20:50:19 +0200264 help
265 Generate dwarf4 debug info. This requires recent versions
266 of gcc and gdb. It makes the debug information larger.
267 But it significantly improves the success of resolving
268 variables in gdb on optimized code.
269
Andrii Nakryikoe83b9f52019-04-02 09:49:50 -0700270config DEBUG_INFO_BTF
271 bool "Generate BTF typeinfo"
272 depends on DEBUG_INFO
Slava Bacherikov7d32e692020-04-02 23:41:39 +0300273 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
274 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
Andrii Nakryikoe83b9f52019-04-02 09:49:50 -0700275 help
276 Generate deduplicated BTF type information from DWARF debug info.
277 Turning this on expects presence of pahole tool, which will convert
278 DWARF type info into equivalent deduplicated BTF type info.
279
Jan Kiszka3ee7b3f2015-02-17 13:46:36 -0800280config GDB_SCRIPTS
281 bool "Provide GDB scripts for kernel debugging"
282 depends on DEBUG_INFO
283 help
284 This creates the required links to GDB helper scripts in the
285 build directory. If you load vmlinux into gdb, the helper
286 scripts will be automatically imported by gdb as well, and
287 additional functions are available to analyze a Linux kernel
Andreas Platschek700199b02016-12-14 15:05:40 -0800288 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
289 for further details.
Jan Kiszka3ee7b3f2015-02-17 13:46:36 -0800290
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700291config ENABLE_MUST_CHECK
292 bool "Enable __must_check logic"
293 default y
294 help
295 Enable the __must_check logic in the kernel build. Disable this to
296 suppress the "warning: ignoring return value of 'foo', declared with
297 attribute warn_unused_result" messages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298
Andi Kleen35bb5b12008-02-22 15:15:03 +0100299config FRAME_WARN
Masahiro Yamadaa83e4ca2020-02-17 00:19:36 +0900300 int "Warn for stack frames larger than"
Andi Kleen35bb5b12008-02-22 15:15:03 +0100301 range 0 8192
Kees Cook0e07f662016-10-27 17:46:41 -0700302 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
Helge Deller432654d2017-09-11 21:41:43 +0200303 default 1280 if (!64BIT && PARISC)
304 default 1024 if (!64BIT && !PARISC)
Andi Kleen35bb5b12008-02-22 15:15:03 +0100305 default 2048 if 64BIT
306 help
307 Tell gcc to warn at build time for stack frames larger than this.
308 Setting this too low will cause a lot of warnings.
309 Setting it to 0 disables the warning.
Andi Kleen35bb5b12008-02-22 15:15:03 +0100310
Randy Dunlap99657c72009-09-18 12:49:22 -0700311config STRIP_ASM_SYMS
312 bool "Strip assembler-generated symbols during link"
313 default n
314 help
315 Strip internal assembler-generated symbols during a link (symbols
316 that look like '.Lxxx') so they don't pollute the output of
317 get_wchan() and suchlike.
318
Andi Kleen1873e872012-03-28 11:51:18 -0700319config READABLE_ASM
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800320 bool "Generate readable assembler code"
321 depends on DEBUG_KERNEL
Don Mullisbf4735a2006-12-10 02:18:37 -0800322 help
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800323 Disable some compiler optimizations that tend to generate human unreadable
324 assembler output. This may make the kernel slightly slower, but it helps
325 to keep kernel developers who have to stare a lot at assembler listings
326 sane.
Don Mullisbf4735a2006-12-10 02:18:37 -0800327
Masahiro Yamadae949f4c2019-06-04 19:13:59 +0900328config HEADERS_INSTALL
329 bool "Install uapi headers to usr/include"
Don Mullisbf4735a2006-12-10 02:18:37 -0800330 depends on !UML
331 help
Masahiro Yamadae949f4c2019-06-04 19:13:59 +0900332 This option will install uapi headers (headers exported to user-space)
333 into the usr/include directory for use during the kernel build.
334 This is unneeded for building the kernel itself, but needed for some
335 user-space program samples. It is also needed by some features such
336 as uapi header sanity checks.
337
Sam Ravnborg91341d42008-01-21 21:31:44 +0100338config DEBUG_SECTION_MISMATCH
339 bool "Enable full Section mismatch analysis"
Sam Ravnborg91341d42008-01-21 21:31:44 +0100340 help
341 The section mismatch analysis checks if there are illegal
342 references from one section to another section.
Michael Wittene809ab02011-04-17 04:08:48 +0000343 During linktime or runtime, some sections are dropped;
344 any use of code/data previously in these sections would
Sam Ravnborg91341d42008-01-21 21:31:44 +0100345 most likely result in an oops.
Michael Wittene809ab02011-04-17 04:08:48 +0000346 In the code, functions and variables are annotated with
Paul Gortmaker0db06282013-06-19 14:53:51 -0400347 __init,, etc. (see the full list in include/linux/init.h),
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100348 which results in the code/data being placed in specific sections.
Michael Wittene809ab02011-04-17 04:08:48 +0000349 The section mismatch analysis is always performed after a full
350 kernel build, and enabling this option causes the following
Masahiro Yamadab7dca6d2019-07-17 15:17:57 +0900351 additional step to occur:
Michael Wittene809ab02011-04-17 04:08:48 +0000352 - Add the option -fno-inline-functions-called-once to gcc commands.
353 When inlining a function annotated with __init in a non-init
354 function, we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100355 the analysis would not catch the illegal reference.
Michael Wittene809ab02011-04-17 04:08:48 +0000356 This option tells gcc to inline less (but it does result in
357 a larger kernel).
Sam Ravnborg91341d42008-01-21 21:31:44 +0100358
Nicolas Boichat47490ec2015-10-06 09:44:42 +1030359config SECTION_MISMATCH_WARN_ONLY
360 bool "Make section mismatch errors non-fatal"
361 default y
362 help
363 If you say N here, the build process will fail if there are any
364 section mismatch, instead of just throwing warnings.
365
366 If unsure, say Y.
367
Feng Tang09c60542020-08-11 18:34:13 -0700368config DEBUG_FORCE_FUNCTION_ALIGN_32B
369 bool "Force all function address 32B aligned" if EXPERT
370 help
371 There are cases that a commit from one domain changes the function
372 address alignment of other domains, and cause magic performance
373 bump (regression or improvement). Enable this option will help to
374 verify if the bump is caused by function alignment changes, while
375 it will slightly increase the kernel size and affect icache usage.
376
377 It is mainly for debug and performance tuning use.
378
Dave Hansen6dfc0662013-07-01 13:04:46 -0700379#
380# Select this config option from the architecture Kconfig, if it
381# is preferred to always offer frame pointers as a config
382# option on the architecture (regardless of KERNEL_DEBUG):
383#
384config ARCH_WANT_FRAME_POINTERS
385 bool
Dave Hansen6dfc0662013-07-01 13:04:46 -0700386
387config FRAME_POINTER
388 bool "Compile the kernel with frame pointers"
Arnd Bergmanna687a532018-03-07 23:30:54 +0100389 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
Dave Hansen6dfc0662013-07-01 13:04:46 -0700390 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
391 help
392 If you say Y here the resulting kernel image will be slightly
393 larger and slower, but it gives very useful debugging information
394 in case of kernel bugs. (precise oopses/stacktraces/warnings)
395
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -0600396config STACK_VALIDATION
397 bool "Compile-time stack metadata validation"
398 depends on HAVE_STACK_VALIDATION
399 default n
400 help
401 Add compile-time checks to validate stack metadata, including frame
402 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
403 that runtime stack traces are more reliable.
404
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500405 This is also a prerequisite for generation of ORC unwind data, which
Josh Poimboeuf11af8472017-10-13 15:02:00 -0500406 is needed for CONFIG_UNWINDER_ORC.
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500407
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -0600408 For more information, see
409 tools/objtool/Documentation/stack-validation.txt.
410
Peter Zijlstra6804c1a2020-03-18 13:33:54 +0100411config VMLINUX_VALIDATION
412 bool
413 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
414 default y
415
Dave Hansen6dfc0662013-07-01 13:04:46 -0700416config DEBUG_FORCE_WEAK_PER_CPU
417 bool "Force weak per-cpu definitions"
418 depends on DEBUG_KERNEL
419 help
420 s390 and alpha require percpu variables in modules to be
421 defined weak to work around addressing range issue which
422 puts the following two restrictions on percpu variable
423 definitions.
424
425 1. percpu symbols must be unique whether static or not
426 2. percpu variables can't be defined inside a function
427
428 To ensure that generic code follows the above rules, this
429 option forces all percpu variables to be defined as weak.
430
431endmenu # "Compiler options"
432
Changbin Du6210b642019-12-06 17:03:42 -0800433menu "Generic Kernel Debugging Instruments"
434
Dave Hansen6dfc0662013-07-01 13:04:46 -0700435config MAGIC_SYSRQ
436 bool "Magic SysRq key"
437 depends on !UML
438 help
439 If you say Y here, you will have some control over the system even
440 if the system crashes for example during kernel debugging (e.g., you
441 will be able to flush the buffer cache to disk, reboot the system
442 immediately or dump some status information). This is accomplished
443 by pressing various keys while holding SysRq (Alt+PrintScreen). It
444 also works on a serial console (on PC hardware at least), if you
445 send a BREAK and then within 5 seconds a command keypress. The
Hans Holmbergf8998c22017-03-16 09:37:32 +0100446 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
447 Don't say Y unless you really know what this hack does.
Dave Hansen6dfc0662013-07-01 13:04:46 -0700448
Ben Hutchings8eaede42013-10-07 01:05:46 +0100449config MAGIC_SYSRQ_DEFAULT_ENABLE
450 hex "Enable magic SysRq key functions by default"
451 depends on MAGIC_SYSRQ
452 default 0x1
453 help
454 Specifies which SysRq key functions are enabled by default.
455 This may be set to 1 or 0 to enable or disable them all, or
Hans Holmbergf8998c22017-03-16 09:37:32 +0100456 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
Ben Hutchings8eaede42013-10-07 01:05:46 +0100457
Felix Fietkau732dbf32016-12-22 08:31:34 +0100458config MAGIC_SYSRQ_SERIAL
459 bool "Enable magic SysRq key over serial"
460 depends on MAGIC_SYSRQ
461 default y
462 help
463 Many embedded boards have a disconnected TTL level serial which can
464 generate some garbage that can lead to spurious false sysrq detects.
465 This option allows you to decide whether you want to enable the
466 magic SysRq key.
467
Dmitry Safonov68af4312020-03-02 17:51:35 +0000468config MAGIC_SYSRQ_SERIAL_SEQUENCE
469 string "Char sequence that enables magic SysRq over serial"
470 depends on MAGIC_SYSRQ_SERIAL
471 default ""
472 help
473 Specifies a sequence of characters that can follow BREAK to enable
474 SysRq on a serial console.
475
Dmitry Safonovd3394b32020-03-06 15:31:56 +0000476 If unsure, leave an empty string and the option will not be enabled.
477
Changbin Duec29a5c2019-12-06 17:04:06 -0800478config DEBUG_FS
479 bool "Debug Filesystem"
480 help
481 debugfs is a virtual file system that kernel developers use to put
482 debugging files into. Enable this option to be able to read and
483 write to these files.
484
485 For detailed documentation on the debugfs API, see
486 Documentation/filesystems/.
487
488 If unsure, say N.
489
Peter Enderborga24c6f72020-07-16 09:15:11 +0200490choice
491 prompt "Debugfs default access"
492 depends on DEBUG_FS
493 default DEBUG_FS_ALLOW_ALL
494 help
495 This selects the default access restrictions for debugfs.
496 It can be overridden with kernel command line option
497 debugfs=[on,no-mount,off]. The restrictions apply for API access
498 and filesystem registration.
499
500config DEBUG_FS_ALLOW_ALL
501 bool "Access normal"
502 help
503 No restrictions apply. Both API and filesystem registration
504 is on. This is the normal default operation.
505
506config DEBUG_FS_DISALLOW_MOUNT
507 bool "Do not register debugfs as filesystem"
508 help
509 The API is open but filesystem is not loaded. Clients can still do
510 their work and read with debug tools that do not need
511 debugfs filesystem.
512
513config DEBUG_FS_ALLOW_NONE
514 bool "No access"
515 help
516 Access is off. Clients get -PERM when trying to create nodes in
517 debugfs tree and debugfs is not registered as a filesystem.
518 Client can then back-off or continue without debugfs access.
519
520endchoice
521
Changbin Du6210b642019-12-06 17:03:42 -0800522source "lib/Kconfig.kgdb"
523
524source "lib/Kconfig.ubsan"
525
526endmenu
527
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800528config DEBUG_KERNEL
529 bool "Kernel debugging"
530 help
531 Say Y here if you are developing drivers or trying to debug and
532 identify kernel problems.
533
Sinan Kayac66d7a22019-05-14 15:44:00 -0700534config DEBUG_MISC
535 bool "Miscellaneous debug code"
536 default DEBUG_KERNEL
537 depends on DEBUG_KERNEL
538 help
539 Say Y here if you need to enable miscellaneous debug code that should
540 be under a more specific debug option but isn't.
541
542
Dave Hansen0610c8a2013-07-01 13:04:43 -0700543menu "Memory Debugging"
David Woodhousea304e1b2007-02-12 00:52:00 -0800544
Masahiro Yamada8636a1f2018-12-11 20:01:04 +0900545source "mm/Kconfig.debug"
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800546
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700547config DEBUG_OBJECTS
548 bool "Debug object operations"
549 depends on DEBUG_KERNEL
550 help
551 If you say Y here, additional code will be inserted into the
552 kernel to track the life time of various objects and validate
553 the operations on those objects.
554
555config DEBUG_OBJECTS_SELFTEST
556 bool "Debug objects selftest"
557 depends on DEBUG_OBJECTS
558 help
559 This enables the selftest of the object debug code.
560
561config DEBUG_OBJECTS_FREE
562 bool "Debug objects in freed memory"
563 depends on DEBUG_OBJECTS
564 help
565 This enables checks whether a k/v free operation frees an area
566 which contains an object which has not been deactivated
567 properly. This can make kmalloc/kfree-intensive workloads
568 much slower.
569
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700570config DEBUG_OBJECTS_TIMERS
571 bool "Debug timer objects"
572 depends on DEBUG_OBJECTS
573 help
574 If you say Y here, additional code will be inserted into the
575 timer routines to track the life time of timer objects and
576 validate the timer operations.
577
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900578config DEBUG_OBJECTS_WORK
579 bool "Debug work objects"
580 depends on DEBUG_OBJECTS
581 help
582 If you say Y here, additional code will be inserted into the
583 work queue routines to track the life time of work objects and
584 validate the work operations.
585
Mathieu Desnoyers551d55a2010-04-17 08:48:42 -0400586config DEBUG_OBJECTS_RCU_HEAD
587 bool "Debug RCU callbacks objects"
Mathieu Desnoyersfc2ecf72011-02-23 09:42:14 -0800588 depends on DEBUG_OBJECTS
Mathieu Desnoyers551d55a2010-04-17 08:48:42 -0400589 help
590 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
591
Tejun Heoe2852ae2010-10-26 14:23:05 -0700592config DEBUG_OBJECTS_PERCPU_COUNTER
593 bool "Debug percpu counter objects"
594 depends on DEBUG_OBJECTS
595 help
596 If you say Y here, additional code will be inserted into the
597 percpu counter routines to track the life time of percpu counter
598 objects and validate the percpu counter operations.
599
Ingo Molnar3ae70202008-11-26 10:02:00 +0100600config DEBUG_OBJECTS_ENABLE_DEFAULT
601 int "debug_objects bootup default value (0-1)"
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800602 range 0 1
603 default "1"
604 depends on DEBUG_OBJECTS
605 help
606 Debug objects boot parameter default value
Ingo Molnar3ae70202008-11-26 10:02:00 +0100607
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800609 bool "Debug slab memory allocations"
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -0800610 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 help
612 Say Y here to have the kernel do limited verification on memory
613 allocation as well as poisoning memory on free to catch use of freed
614 memory. This can make kmalloc/kfree-intensive workloads much slower.
615
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700616config SLUB_DEBUG_ON
617 bool "SLUB debugging on by default"
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -0800618 depends on SLUB && SLUB_DEBUG
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700619 default n
620 help
621 Boot with debugging on by default. SLUB boots by default with
622 the runtime debug capabilities switched off. Enabling this is
623 equivalent to specifying the "slub_debug" parameter on boot.
624 There is no support for more fine grained debug control like
625 possible with slub_debug=xxx. SLUB debugging may be switched
626 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
627 "slub_debug=-".
628
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800629config SLUB_STATS
630 default n
631 bool "Enable SLUB performance statistics"
Christoph Lameterab4d5ed2010-10-05 13:57:26 -0500632 depends on SLUB && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800633 help
634 SLUB statistics are useful to debug SLUBs allocation behavior in
635 order find ways to optimize the allocator. This should never be
636 enabled for production use since keeping statistics slows down
637 the allocator by a few percentage points. The slabinfo command
638 supports the determination of the most active slabs to figure
639 out which slabs are relevant to a particular load.
640 Try running: slabinfo -DA
641
Catalin Marinasb69ec422012-10-08 16:28:11 -0700642config HAVE_DEBUG_KMEMLEAK
643 bool
644
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100645config DEBUG_KMEMLEAK
646 bool "Kernel memory leak detector"
Kees Cook525c1f92013-01-16 18:54:16 -0800647 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
Catalin Marinas79e0d9b2011-04-27 17:06:19 +0100648 select DEBUG_FS
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100649 select STACKTRACE if STACKTRACE_SUPPORT
650 select KALLSYMS
Randy Dunlapb60e26a2009-11-06 15:33:45 -0800651 select CRC32
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100652 help
653 Say Y here if you want to enable the memory leak
654 detector. The memory allocation/freeing is traced in a way
655 similar to the Boehm's conservative garbage collector, the
656 difference being that the orphan objects are not freed but
657 only shown in /sys/kernel/debug/kmemleak. Enabling this
658 feature will introduce an overhead to memory
Andreas Platschek700199b02016-12-14 15:05:40 -0800659 allocations. See Documentation/dev-tools/kmemleak.rst for more
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100660 details.
661
Catalin Marinasbf96d1e2009-06-23 14:40:27 +0100662 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
663 of finding leaks due to the slab objects poisoning.
664
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100665 In order to access the kmemleak file, debugfs needs to be
666 mounted (usually at /sys/kernel/debug).
667
Catalin Marinasc5665862019-09-23 15:34:05 -0700668config DEBUG_KMEMLEAK_MEM_POOL_SIZE
669 int "Kmemleak memory pool size"
Catalin Marinasa9d90582009-06-25 10:16:11 +0100670 depends on DEBUG_KMEMLEAK
Qian Caic59180a2019-09-23 15:34:10 -0700671 range 200 1000000
Nicolas Boichatb751c522019-09-23 15:33:55 -0700672 default 16000
Catalin Marinasa9d90582009-06-25 10:16:11 +0100673 help
674 Kmemleak must track all the memory allocations to avoid
675 reporting false positives. Since memory may be allocated or
Catalin Marinasc5665862019-09-23 15:34:05 -0700676 freed before kmemleak is fully initialised, use a static pool
677 of metadata objects to track such callbacks. After kmemleak is
678 fully initialised, this memory pool acts as an emergency one
679 if slab allocations fail.
Catalin Marinasa9d90582009-06-25 10:16:11 +0100680
Catalin Marinas0822ee42009-06-11 13:24:14 +0100681config DEBUG_KMEMLEAK_TEST
682 tristate "Simple test for the kernel memory leak detector"
Daniel Baluta97182692011-04-04 15:06:44 -0700683 depends on DEBUG_KMEMLEAK && m
Catalin Marinas0822ee42009-06-11 13:24:14 +0100684 help
Daniel Baluta97182692011-04-04 15:06:44 -0700685 This option enables a module that explicitly leaks memory.
Catalin Marinas0822ee42009-06-11 13:24:14 +0100686
687 If unsure, say N.
688
Jason Baronab0155a2010-07-19 11:54:17 +0100689config DEBUG_KMEMLEAK_DEFAULT_OFF
690 bool "Default kmemleak to off"
691 depends on DEBUG_KMEMLEAK
692 help
693 Say Y here to disable kmemleak by default. It can then be enabled
694 on the command line via kmemleak=on.
695
Sri Krishna chowdaryd53ce042018-12-28 00:38:54 -0800696config DEBUG_KMEMLEAK_AUTO_SCAN
697 bool "Enable kmemleak auto scan thread on boot up"
698 default y
699 depends on DEBUG_KMEMLEAK
700 help
701 Depending on the cpu, kmemleak scan may be cpu intensive and can
702 stall user tasks at times. This option enables/disables automatic
703 kmemleak scan at boot up.
704
705 Say N here to disable kmemleak auto scan thread to stop automatic
706 scanning. Disabling this option disables automatic reporting of
707 memory leaks.
708
709 If unsure, say Y.
710
Dave Hansen0610c8a2013-07-01 13:04:43 -0700711config DEBUG_STACK_USAGE
712 bool "Stack utilization instrumentation"
Helge Deller6c31da32016-03-19 17:54:10 +0100713 depends on DEBUG_KERNEL && !IA64
Dave Hansen0610c8a2013-07-01 13:04:43 -0700714 help
715 Enables the display of the minimum amount of free stack which each
716 task has ever had available in the sysrq-T and sysrq-P debug output.
717
718 This option will slow down process creation somewhat.
719
Changbin Dudc9b9632019-12-06 17:03:57 -0800720config SCHED_STACK_END_CHECK
721 bool "Detect stack corruption on calls to schedule()"
722 depends on DEBUG_KERNEL
723 default n
724 help
725 This option checks for a stack overrun on calls to schedule().
726 If the stack end location is found to be over written always panic as
727 the content of the corrupted region can no longer be trusted.
728 This is to ensure no erroneous behaviour occurs which could result in
729 data corruption or a sporadic crash at a later stage once the region
730 is examined. The runtime overhead introduced is minimal.
731
Anshuman Khandual399145f2020-06-04 16:47:15 -0700732config ARCH_HAS_DEBUG_VM_PGTABLE
733 bool
734 help
735 An architecture should select this when it can successfully
736 build and run DEBUG_VM_PGTABLE.
737
Dave Hansen0610c8a2013-07-01 13:04:43 -0700738config DEBUG_VM
739 bool "Debug VM"
740 depends on DEBUG_KERNEL
741 help
742 Enable this to turn on extended checks in the virtual-memory system
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800743 that may impact performance.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700744
745 If unsure, say N.
746
Davidlohr Bueso4f115142014-06-04 16:06:46 -0700747config DEBUG_VM_VMACACHE
748 bool "Debug VMA caching"
749 depends on DEBUG_VM
750 help
751 Enable this to turn on VMA caching debug information. Doing so
752 can cause significant overhead, so only enable it in non-production
753 environments.
754
755 If unsure, say N.
756
Dave Hansen0610c8a2013-07-01 13:04:43 -0700757config DEBUG_VM_RB
758 bool "Debug VM red-black trees"
759 depends on DEBUG_VM
760 help
Davidlohr Buesoa663dad2014-04-18 15:07:22 -0700761 Enable VM red-black tree debugging information and extra validations.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700762
763 If unsure, say N.
764
Kirill A. Shutemov95ad9752016-01-15 16:51:21 -0800765config DEBUG_VM_PGFLAGS
766 bool "Debug page-flags operations"
767 depends on DEBUG_VM
768 help
769 Enables extra validation on page flags operations.
770
771 If unsure, say N.
772
Anshuman Khandual399145f2020-06-04 16:47:15 -0700773config DEBUG_VM_PGTABLE
774 bool "Debug arch page table for semantics compliance"
775 depends on MMU
776 depends on ARCH_HAS_DEBUG_VM_PGTABLE
777 default y if DEBUG_VM
778 help
779 This option provides a debug method which can be used to test
780 architecture page table helper functions on various platforms in
781 verifying if they comply with expected generic MM semantics. This
782 will help architecture code in making sure that any changes or
783 new additions of these helpers still conform to expected
784 semantics of the generic MM. Platforms will have to opt in for
785 this through ARCH_HAS_DEBUG_VM_PGTABLE.
786
787 If unsure, say N.
788
Laura Abbottfa5b6ec2017-01-10 13:35:40 -0800789config ARCH_HAS_DEBUG_VIRTUAL
790 bool
791
Dave Hansen0610c8a2013-07-01 13:04:43 -0700792config DEBUG_VIRTUAL
793 bool "Debug VM translations"
Laura Abbottfa5b6ec2017-01-10 13:35:40 -0800794 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
Dave Hansen0610c8a2013-07-01 13:04:43 -0700795 help
796 Enable some costly sanity checks in virtual to page code. This can
797 catch mistakes with virt_to_page() and friends.
798
799 If unsure, say N.
800
801config DEBUG_NOMMU_REGIONS
802 bool "Debug the global anon/private NOMMU mapping region tree"
803 depends on DEBUG_KERNEL && !MMU
804 help
805 This option causes the global tree of anonymous and private mapping
806 regions to be regularly checked for invalid topology.
807
808config DEBUG_MEMORY_INIT
809 bool "Debug memory initialisation" if EXPERT
810 default !EXPERT
811 help
812 Enable this for additional checks during memory initialisation.
813 The sanity checks verify aspects of the VM such as the memory model
814 and other information provided by the architecture. Verbose
815 information will be printed at KERN_DEBUG loglevel depending
816 on the mminit_loglevel= command-line option.
817
818 If unsure, say Y
819
820config MEMORY_NOTIFIER_ERROR_INJECT
821 tristate "Memory hotplug notifier error injection module"
822 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
823 help
824 This option provides the ability to inject artificial errors to
825 memory hotplug notifier chain callbacks. It is controlled through
826 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
827
828 If the notifier call chain should be failed with some events
829 notified, write the error code to "actions/<notifier event>/error".
830
831 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
832
833 # cd /sys/kernel/debug/notifier-error-inject/memory
834 # echo -12 > actions/MEM_GOING_OFFLINE/error
835 # echo offline > /sys/devices/system/memory/memoryXXX/state
836 bash: echo: write error: Cannot allocate memory
837
838 To compile this code as a module, choose M here: the module will
839 be called memory-notifier-error-inject.
840
841 If unsure, say N.
842
843config DEBUG_PER_CPU_MAPS
844 bool "Debug access to per_cpu maps"
845 depends on DEBUG_KERNEL
846 depends on SMP
847 help
848 Say Y to verify that the per_cpu map being accessed has
849 been set up. This adds a fair amount of code to kernel memory
850 and decreases performance.
851
852 Say N if unsure.
853
854config DEBUG_HIGHMEM
855 bool "Highmem debugging"
856 depends on DEBUG_KERNEL && HIGHMEM
857 help
Geert Uytterhoevenb1357c92014-04-14 18:55:50 +0200858 This option enables additional error checking for high memory
859 systems. Disable for production systems.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700860
861config HAVE_DEBUG_STACKOVERFLOW
862 bool
863
864config DEBUG_STACKOVERFLOW
865 bool "Check for stack overflows"
866 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900867 help
Dave Hansen0610c8a2013-07-01 13:04:43 -0700868 Say Y here if you want to check for overflows of kernel, IRQ
Borislav Petkovedb0ec02015-01-25 19:50:34 +0100869 and exception stacks (if your architecture uses them). This
Dave Hansen0610c8a2013-07-01 13:04:43 -0700870 option will show detailed messages if free stack space drops
871 below a certain limit.
872
873 These kinds of bugs usually occur when call-chains in the
874 kernel get too deep, especially when interrupts are
875 involved.
876
877 Use this in cases where you see apparently random memory
878 corruption, especially if it appears in 'struct thread_info'
879
880 If in doubt, say "N".
881
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -0800882source "lib/Kconfig.kasan"
883
Dave Hansen0610c8a2013-07-01 13:04:43 -0700884endmenu # "Memory Debugging"
885
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886config DEBUG_SHIRQ
887 bool "Debug shared IRQ handlers"
Martin Schwidefsky0244ad02013-08-30 09:39:53 +0200888 depends on DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 help
Wolfram Sang0a2fae22020-07-03 00:20:24 +0200890 Enable this to generate a spurious interrupt just before a shared
891 interrupt handler is deregistered (generating one when registering
892 is currently disabled). Drivers need to handle this correctly. Some
893 don't and need to be caught.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
Changbin Duf43a2892019-12-06 17:03:54 -0800895menu "Debug Oops, Lockups and Hangs"
896
897config PANIC_ON_OOPS
898 bool "Panic on Oops"
899 help
900 Say Y here to enable the kernel to panic when it oopses. This
901 has the same effect as setting oops=panic on the kernel command
902 line.
903
904 This feature is useful to ensure that the kernel does not do
905 anything erroneous after an oops which could result in data
906 corruption or other issues.
907
908 Say N if unsure.
909
910config PANIC_ON_OOPS_VALUE
911 int
912 range 0 1
913 default 0 if !PANIC_ON_OOPS
914 default 1 if PANIC_ON_OOPS
915
916config PANIC_TIMEOUT
917 int "panic timeout"
918 default 0
919 help
920 Set the timeout value (in seconds) until a reboot occurs when the
921 the kernel panics. If n = 0, then we wait forever. A timeout
922 value n > 0 will wait n seconds before rebooting, while a timeout
923 value n < 0 will reboot immediately.
Dave Hansen92aef8fb2013-07-01 13:04:50 -0700924
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925config LOCKUP_DETECTOR
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700926 bool
927
928config SOFTLOCKUP_DETECTOR
929 bool "Detect Soft Lockups"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 depends on DEBUG_KERNEL && !S390
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700931 select LOCKUP_DETECTOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 help
933 Say Y here to enable the kernel to act as a watchdog to detect
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700934 soft lockups.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
936 Softlockups are bugs that cause the kernel to loop in kernel
937 mode for more than 20 seconds, without giving other tasks a
938 chance to run. The current stack trace is displayed upon
939 detection and the system will stay locked up.
940
Randy Dunlap5f00ae02018-04-10 16:32:51 -0700941config BOOTPARAM_SOFTLOCKUP_PANIC
942 bool "Panic (Reboot) On Soft Lockups"
943 depends on SOFTLOCKUP_DETECTOR
944 help
945 Say Y here to enable the kernel to panic on "soft lockups",
946 which are bugs that cause the kernel to loop in kernel
947 mode for more than 20 seconds (configurable using the watchdog_thresh
948 sysctl), without giving other tasks a chance to run.
949
950 The panic can be used in combination with panic_timeout,
951 to cause the system to reboot automatically after a
952 lockup has been detected. This feature is useful for
953 high-availability systems that have uptime guarantees and
954 where a lockup must be resolved ASAP.
955
956 Say N if unsure.
957
958config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
959 int
960 depends on SOFTLOCKUP_DETECTOR
961 range 0 1
962 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
963 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
964
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700965config HARDLOCKUP_DETECTOR_PERF
966 bool
967 select SOFTLOCKUP_DETECTOR
968
969#
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200970# Enables a timestamp based low pass filter to compensate for perf based
971# hard lockup detection which runs too fast due to turbo modes.
972#
973config HARDLOCKUP_CHECK_TIMESTAMP
974 bool
975
976#
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700977# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
978# lockup detector rather than the perf based detector.
979#
980config HARDLOCKUP_DETECTOR
981 bool "Detect Hard Lockups"
982 depends on DEBUG_KERNEL && !S390
983 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
984 select LOCKUP_DETECTOR
985 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
986 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
987 help
988 Say Y here to enable the kernel to act as a watchdog to detect
989 hard lockups.
990
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 Hardlockups are bugs that cause the CPU to loop in kernel mode
992 for more than 10 seconds, without letting other interrupts have a
993 chance to run. The current stack trace is displayed upon detection
994 and the system will stay locked up.
995
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996config BOOTPARAM_HARDLOCKUP_PANIC
997 bool "Panic (Reboot) On Hard Lockups"
998 depends on HARDLOCKUP_DETECTOR
999 help
1000 Say Y here to enable the kernel to panic on "hard lockups",
1001 which are bugs that cause the kernel to loop in kernel
1002 mode with interrupts disabled for more than 10 seconds (configurable
1003 using the watchdog_thresh sysctl).
1004
1005 Say N if unsure.
1006
1007config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1008 int
1009 depends on HARDLOCKUP_DETECTOR
1010 range 0 1
1011 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1012 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1013
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014config DETECT_HUNG_TASK
1015 bool "Detect Hung Tasks"
1016 depends on DEBUG_KERNEL
Nicholas Piggin05a4a952017-07-12 14:35:46 -07001017 default SOFTLOCKUP_DETECTOR
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 help
1019 Say Y here to enable the kernel to detect "hung tasks",
1020 which are bugs that cause the task to be stuck in
Vivien Didelot96b03ab2016-09-22 16:55:13 -04001021 uninterruptible "D" state indefinitely.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
1023 When a hung task is detected, the kernel will print the
1024 current stack trace (which you should report), but the
1025 task will stay in uninterruptible state. If lockdep is
1026 enabled then all held locks will also be reported. This
1027 feature has negligible overhead.
Al Viro871751e2006-03-25 03:06:39 -08001028
1029config DEFAULT_HUNG_TASK_TIMEOUT
1030 int "Default timeout for hung task detection (in seconds)"
1031 depends on DETECT_HUNG_TASK
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032 default 120
1033 help
Ingo Molnar8637c092006-07-03 00:24:38 -07001034 This option controls the default timeout (in seconds) used
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 to determine when a task has become non-responsive and should
1036 be considered hung.
1037
1038 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1039 sysctl or by writing a value to
1040 /proc/sys/kernel/hung_task_timeout_secs.
1041
Ingo Molnare7eebaf2006-06-27 02:54:55 -07001042 A timeout of 0 disables the check. The default is two minutes.
1043 Keeping the default should be fine in most cases.
Ingo Molnare7eebaf2006-06-27 02:54:55 -07001044
1045config BOOTPARAM_HUNG_TASK_PANIC
1046 bool "Panic (Reboot) On Hung Tasks"
1047 depends on DETECT_HUNG_TASK
1048 help
1049 Say Y here to enable the kernel to panic on "hung tasks",
1050 which are bugs that cause the kernel to leave a task stuck
1051 in uninterruptible "D" state.
1052
1053 The panic can be used in combination with panic_timeout,
Thomas Gleixner61a87122006-06-27 02:54:56 -07001054 to cause the system to reboot automatically after a
1055 hung task has been detected. This feature is useful for
Roman Zippela1583d32006-06-27 02:55:00 -07001056 high-availability systems that have uptime guarantees and
Thomas Gleixner61a87122006-06-27 02:54:56 -07001057 where a hung tasks must be resolved ASAP.
1058
1059 Say N if unsure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060
Hugh Dickins048c8bc2006-11-01 05:44:54 +11001061config BOOTPARAM_HUNG_TASK_PANIC_VALUE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 int
1063 depends on DETECT_HUNG_TASK
1064 range 0 1
1065 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1066 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1067
Tejun Heo82607adc2015-12-08 11:28:04 -05001068config WQ_WATCHDOG
1069 bool "Detect Workqueue Stalls"
1070 depends on DEBUG_KERNEL
1071 help
1072 Say Y here to enable stall detection on workqueues. If a
1073 worker pool doesn't make forward progress on a pending work
1074 item for over a given amount of time, 30s by default, a
1075 warning message is printed along with dump of workqueue
1076 state. This can be configured through kernel parameter
1077 "workqueue.watchdog_thresh" and its sysfs counterpart.
1078
Konstantin Khlebnikov30428ef2020-04-06 20:09:47 -07001079config TEST_LOCKUP
1080 tristate "Test module to generate lockups"
Tiezhu Yang63646bc2020-08-11 18:34:44 -07001081 depends on m
Konstantin Khlebnikov30428ef2020-04-06 20:09:47 -07001082 help
1083 This builds the "test_lockup" module that helps to make sure
1084 that watchdogs and lockup detectors are working properly.
1085
1086 Depending on module parameters it could emulate soft or hard
1087 lockup, "hung task", or locking arbitrary lock for a long time.
1088 Also it could generate series of lockups with cooling-down periods.
1089
1090 If unsure, say N.
1091
Dave Hansen92aef8fb2013-07-01 13:04:50 -07001092endmenu # "Debug lockups and hangs"
1093
Changbin Duebebdd02019-12-06 17:04:00 -08001094menu "Scheduler Debugging"
Jason Baron5800dc32013-11-25 23:23:04 +00001095
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096config SCHED_DEBUG
1097 bool "Collect scheduler debugging info"
1098 depends on DEBUG_KERNEL && PROC_FS
1099 default y
1100 help
1101 If you say Y here, the /proc/sched_debug file will be provided
1102 that can help debug the scheduler. The runtime overhead of this
1103 option is minimal.
1104
Naveen N. Raof6db8342015-06-25 23:53:37 +05301105config SCHED_INFO
1106 bool
1107 default n
1108
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109config SCHEDSTATS
1110 bool "Collect scheduler statistics"
1111 depends on DEBUG_KERNEL && PROC_FS
Naveen N. Raof6db8342015-06-25 23:53:37 +05301112 select SCHED_INFO
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 help
1114 If you say Y here, additional code will be inserted into the
1115 scheduler and related routines to collect statistics about
1116 scheduler behavior and provide them in /proc/schedstat. These
1117 stats may be useful for both tuning and debugging the scheduler
1118 If you aren't debugging the scheduler or trying to tune a specific
1119 application, you can say N to avoid the very slight overhead
1120 this adds.
1121
Changbin Duebebdd02019-12-06 17:04:00 -08001122endmenu
Aaron Tomlin0d9e2632014-09-12 14:16:19 +01001123
John Stultz3c17ad12015-03-11 21:16:32 -07001124config DEBUG_TIMEKEEPING
1125 bool "Enable extra timekeeping sanity checking"
1126 help
1127 This option will enable additional timekeeping sanity checks
1128 which may be helpful when diagnosing issues where timekeeping
1129 problems are suspected.
1130
1131 This may include checks in the timekeeping hotpaths, so this
1132 option may have a (very small) performance impact to some
1133 workloads.
1134
1135 If unsure, say N.
1136
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137config DEBUG_PREEMPT
1138 bool "Debug preemptible kernel"
Sebastian Andrzej Siewior9f472862019-10-15 21:18:19 +02001139 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 default y
1141 help
1142 If you say Y here then the kernel will use a debug variant of the
1143 commonly used smp_processor_id() function and will print warnings
1144 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1145 will detect preemption count underflows.
1146
Dave Hansen9eade162013-07-01 13:04:47 -07001147menu "Lock Debugging (spinlocks, mutexes, etc...)"
1148
Waiman Longf07cbeb2018-03-30 17:27:59 -04001149config LOCK_DEBUGGING_SUPPORT
1150 bool
1151 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1152 default y
1153
Waiman Long19193bc2018-03-30 17:28:00 -04001154config PROVE_LOCKING
1155 bool "Lock debugging: prove locking correctness"
1156 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1157 select LOCKDEP
1158 select DEBUG_SPINLOCK
1159 select DEBUG_MUTEXES
1160 select DEBUG_RT_MUTEXES if RT_MUTEXES
Waiman Longc71fd892019-05-20 16:59:00 -04001161 select DEBUG_RWSEMS
Waiman Long19193bc2018-03-30 17:28:00 -04001162 select DEBUG_WW_MUTEX_SLOWPATH
1163 select DEBUG_LOCK_ALLOC
Ahmed S. Darwish8fd8ad52020-07-20 17:55:13 +02001164 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
Waiman Long19193bc2018-03-30 17:28:00 -04001165 select TRACE_IRQFLAGS
1166 default n
1167 help
1168 This feature enables the kernel to prove that all locking
1169 that occurs in the kernel runtime is mathematically
1170 correct: that under no circumstance could an arbitrary (and
1171 not yet triggered) combination of observed locking
1172 sequences (on an arbitrary number of CPUs, running an
1173 arbitrary number of tasks and interrupt contexts) cause a
1174 deadlock.
1175
1176 In short, this feature enables the kernel to report locking
1177 related deadlocks before they actually occur.
1178
1179 The proof does not depend on how hard and complex a
1180 deadlock scenario would be to trigger: how many
1181 participant CPUs, tasks and irq-contexts would be needed
1182 for it to trigger. The proof also does not depend on
1183 timing: if a race and a resulting deadlock is possible
1184 theoretically (no matter how unlikely the race scenario
1185 is), it will be proven so and will immediately be
1186 reported by the kernel (once the event is observed that
1187 makes the deadlock theoretically possible).
1188
1189 If a deadlock is impossible (i.e. the locking rules, as
1190 observed by the kernel, are mathematically correct), the
1191 kernel reports nothing.
1192
1193 NOTE: this feature can also be enabled for rwlocks, mutexes
1194 and rwsems - in which case all dependencies between these
1195 different locking variants are observed and mapped too, and
1196 the proof of observed correctness is also maintained for an
1197 arbitrary combination of these separate locking variants.
1198
Mauro Carvalho Chehab387b1462019-04-10 08:32:41 -03001199 For more details, see Documentation/locking/lockdep-design.rst.
Waiman Long19193bc2018-03-30 17:28:00 -04001200
Peter Zijlstrade8f5e42020-03-21 12:26:01 +01001201config PROVE_RAW_LOCK_NESTING
1202 bool "Enable raw_spinlock - spinlock nesting checks"
1203 depends on PROVE_LOCKING
1204 default n
1205 help
1206 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1207 that the lock nesting rules for PREEMPT_RT enabled kernels are
1208 not violated.
1209
1210 NOTE: There are known nesting problems. So if you enable this
1211 option expect lockdep splats until these problems have been fully
1212 addressed which is work in progress. This config switch allows to
1213 identify and analyze these problems. It will be removed and the
1214 check permanentely enabled once the main issues have been fixed.
1215
1216 If unsure, select N.
1217
Waiman Long19193bc2018-03-30 17:28:00 -04001218config LOCK_STAT
1219 bool "Lock usage statistics"
1220 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1221 select LOCKDEP
1222 select DEBUG_SPINLOCK
1223 select DEBUG_MUTEXES
1224 select DEBUG_RT_MUTEXES if RT_MUTEXES
1225 select DEBUG_LOCK_ALLOC
1226 default n
1227 help
1228 This feature enables tracking lock contention points
1229
Mauro Carvalho Chehab387b1462019-04-10 08:32:41 -03001230 For more details, see Documentation/locking/lockstat.rst
Waiman Long19193bc2018-03-30 17:28:00 -04001231
1232 This also enables lock events required by "perf lock",
1233 subcommand of perf.
1234 If you want to use "perf lock", you also need to turn on
1235 CONFIG_EVENT_TRACING.
1236
1237 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1238 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1239
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240config DEBUG_RT_MUTEXES
1241 bool "RT Mutex debugging, deadlock detection"
1242 depends on DEBUG_KERNEL && RT_MUTEXES
1243 help
1244 This allows rt mutex semantics violations and rt mutex related
1245 deadlocks (lockups) to be detected and reported automatically.
1246
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001248 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 depends on DEBUG_KERNEL
Raghavendra K Te335e3e2012-03-22 15:25:08 +05301250 select UNINLINE_SPIN_UNLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 help
1252 Say Y here and build SMP to catch missing spinlock initialization
1253 and certain other kinds of spinlock errors commonly made. This is
1254 best used in conjunction with the NMI watchdog so that spinlock
1255 deadlocks are also debuggable.
1256
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001257config DEBUG_MUTEXES
1258 bool "Mutex debugging: basic checks"
1259 depends on DEBUG_KERNEL
1260 help
1261 This feature allows mutex semantics violations to be detected and
1262 reported.
1263
Daniel Vetter23010022013-06-20 13:31:17 +02001264config DEBUG_WW_MUTEX_SLOWPATH
1265 bool "Wait/wound mutex debugging: Slowpath testing"
Waiman Longf07cbeb2018-03-30 17:27:59 -04001266 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Daniel Vetter23010022013-06-20 13:31:17 +02001267 select DEBUG_LOCK_ALLOC
1268 select DEBUG_SPINLOCK
1269 select DEBUG_MUTEXES
1270 help
1271 This feature enables slowpath testing for w/w mutex users by
1272 injecting additional -EDEADLK wound/backoff cases. Together with
1273 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1274 will test all possible w/w mutex interface abuse with the
1275 exception of simply not acquiring all the required locks.
Rob Clark4d692372014-08-27 11:19:26 -04001276 Note that this feature can introduce significant overhead, so
1277 it really should not be enabled in a production or distro kernel,
1278 even a debug kernel. If you are a driver writer, enable it. If
1279 you are a distro, do not.
Daniel Vetter23010022013-06-20 13:31:17 +02001280
Waiman Long5149cba2018-03-30 17:27:58 -04001281config DEBUG_RWSEMS
1282 bool "RW Semaphore debugging: basic checks"
Waiman Longc71fd892019-05-20 16:59:00 -04001283 depends on DEBUG_KERNEL
Waiman Long5149cba2018-03-30 17:27:58 -04001284 help
Waiman Longc71fd892019-05-20 16:59:00 -04001285 This debugging feature allows mismatched rw semaphore locks
1286 and unlocks to be detected and reported.
Waiman Long5149cba2018-03-30 17:27:58 -04001287
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001288config DEBUG_LOCK_ALLOC
1289 bool "Lock debugging: detect incorrect freeing of live locks"
Waiman Longf07cbeb2018-03-30 17:27:59 -04001290 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001291 select DEBUG_SPINLOCK
1292 select DEBUG_MUTEXES
Peter Zijlstraf5694782016-09-19 12:15:37 +02001293 select DEBUG_RT_MUTEXES if RT_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001294 select LOCKDEP
1295 help
1296 This feature will check whether any held lock (spinlock, rwlock,
1297 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1298 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1299 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1300 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1301 held during task exit.
1302
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001303config LOCKDEP
1304 bool
Waiman Longf07cbeb2018-03-30 17:27:59 -04001305 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001306 select STACKTRACE
Stefan Agnerf9b58e82018-09-30 23:02:33 +01001307 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001308 select KALLSYMS
1309 select KALLSYMS_ALL
1310
Daniel Jordan395102d2017-04-10 11:50:52 -04001311config LOCKDEP_SMALL
1312 bool
1313
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001314config DEBUG_LOCKDEP
1315 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -07001316 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001317 help
1318 If you say Y here, the lock dependency engine will do
1319 additional runtime checks to debug itself, at the price
1320 of more runtime overhead.
1321
Frederic Weisbeckerd902db12011-06-08 19:31:56 +02001322config DEBUG_ATOMIC_SLEEP
1323 bool "Sleep inside atomic section checking"
Frederic Weisbeckere8f7c702011-06-08 01:51:02 +02001324 select PREEMPT_COUNT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 depends on DEBUG_KERNEL
Christoph Hellwig87a4c372018-07-31 13:39:32 +02001326 depends on !ARCH_NO_PREEMPT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 help
1328 If you say Y here, various routines which may sleep will become very
Frederic Weisbeckerd902db12011-06-08 19:31:56 +02001329 noisy if they are called inside atomic sections: when a spinlock is
1330 held, inside an rcu read side critical section, inside preempt disabled
1331 sections, inside an interrupt, etc...
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332
Ingo Molnarcae2ed92006-07-03 00:24:48 -07001333config DEBUG_LOCKING_API_SELFTESTS
1334 bool "Locking API boot-time self-tests"
1335 depends on DEBUG_KERNEL
1336 help
1337 Say Y here if you want the kernel to run a short self-test during
1338 bootup. The self-test checks whether common types of locking bugs
1339 are detected by debugging mechanisms or not. (if you disable
1340 lock debugging then those bugs wont be detected of course.)
1341 The following locking APIs are covered: spinlocks, rwlocks,
1342 mutexes and rwsems.
1343
Paul E. McKenney0af3fe12014-02-04 15:51:41 -08001344config LOCK_TORTURE_TEST
1345 tristate "torture tests for locking"
1346 depends on DEBUG_KERNEL
1347 select TORTURE_TEST
Paul E. McKenney0af3fe12014-02-04 15:51:41 -08001348 help
1349 This option provides a kernel module that runs torture tests
1350 on kernel locking primitives. The kernel module may be built
1351 after the fact on the running kernel to be tested, if desired.
1352
1353 Say Y here if you want kernel locking-primitive torture tests
1354 to be built into the kernel.
1355 Say M if you want these torture tests to build as a module.
1356 Say N if you are unsure.
1357
Chris Wilsonf2a5fec2016-12-01 11:47:06 +00001358config WW_MUTEX_SELFTEST
1359 tristate "Wait/wound mutex selftests"
1360 help
1361 This option provides a kernel module that runs tests on the
1362 on the struct ww_mutex locking API.
1363
1364 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1365 with this test harness.
1366
1367 Say M if you want these self tests to build as a module.
1368 Say N if you are unsure.
1369
Dave Hansen9eade162013-07-01 13:04:47 -07001370endmenu # lock debugging
1371
1372config TRACE_IRQFLAGS
peterz@infradead.orged004952020-07-27 14:48:52 +02001373 depends on TRACE_IRQFLAGS_SUPPORT
Dave Hansen9eade162013-07-01 13:04:47 -07001374 bool
1375 help
1376 Enables hooks to interrupt enabling and disabling for
1377 either tracing or lock debugging.
1378
peterz@infradead.orged004952020-07-27 14:48:52 +02001379config TRACE_IRQFLAGS_NMI
1380 def_bool y
1381 depends on TRACE_IRQFLAGS
1382 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1383
Ingo Molnar8637c092006-07-03 00:24:38 -07001384config STACKTRACE
Dave Jones0c38e1f2014-08-29 15:18:35 -07001385 bool "Stack backtrace support"
Ingo Molnar8637c092006-07-03 00:24:38 -07001386 depends on STACKTRACE_SUPPORT
Dave Jones0c38e1f2014-08-29 15:18:35 -07001387 help
1388 This option causes the kernel to create a /proc/pid/stack for
1389 every process, showing its current stack trace.
1390 It is also used by various kernel debugging features that require
1391 stack trace generation.
Ingo Molnar8637c092006-07-03 00:24:38 -07001392
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001393config WARN_ALL_UNSEEDED_RANDOM
1394 bool "Warn for all uses of unseeded randomness"
1395 default n
Jason A. Donenfeldd06bfd12017-06-07 23:06:55 -04001396 help
1397 Some parts of the kernel contain bugs relating to their use of
1398 cryptographically secure random numbers before it's actually possible
1399 to generate those numbers securely. This setting ensures that these
1400 flaws don't go unnoticed, by enabling a message, should this ever
1401 occur. This will allow people with obscure setups to know when things
1402 are going wrong, so that they might contact developers about fixing
1403 it.
1404
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001405 Unfortunately, on some models of some architectures getting
1406 a fully seeded CRNG is extremely difficult, and so this can
1407 result in dmesg getting spammed for a surprisingly long
1408 time. This is really bad from a security perspective, and
1409 so architecture maintainers really need to do what they can
1410 to get the CRNG seeded sooner after the system is booted.
Thibaut Sautereau4c5d1142018-09-04 15:46:23 -07001411 However, since users cannot do anything actionable to
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001412 address this, by default the kernel will issue only a single
1413 warning for the first use of unseeded randomness.
1414
1415 Say Y here if you want to receive warnings for all uses of
1416 unseeded randomness. This will be of use primarily for
Thibaut Sautereau4c5d1142018-09-04 15:46:23 -07001417 those developers interested in improving the security of
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001418 Linux kernels running on their architecture (or
1419 subarchitecture).
Jason A. Donenfeldd06bfd12017-06-07 23:06:55 -04001420
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421config DEBUG_KOBJECT
1422 bool "kobject debugging"
1423 depends on DEBUG_KERNEL
1424 help
1425 If you say Y here, some extra kobject debugging messages will be sent
Mike Rapoportaca52c32018-10-30 15:07:44 -07001426 to the syslog.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427
Russell Kingc817a672013-06-27 15:06:14 +01001428config DEBUG_KOBJECT_RELEASE
1429 bool "kobject release debugging"
Linus Torvalds2a999aa2013-10-29 08:33:36 -07001430 depends on DEBUG_OBJECTS_TIMERS
Russell Kingc817a672013-06-27 15:06:14 +01001431 help
1432 kobjects are reference counted objects. This means that their
1433 last reference count put is not predictable, and the kobject can
1434 live on past the point at which a driver decides to drop it's
1435 initial reference to the kobject gained on allocation. An
1436 example of this would be a struct device which has just been
1437 unregistered.
1438
1439 However, some buggy drivers assume that after such an operation,
1440 the memory backing the kobject can be immediately freed. This
1441 goes completely against the principles of a refcounted object.
1442
1443 If you say Y here, the kernel will delay the release of kobjects
1444 on the last reference count to improve the visibility of this
1445 kind of kobject release bug.
1446
Catalin Marinas9b2a60c2012-10-08 16:28:13 -07001447config HAVE_DEBUG_BUGVERBOSE
1448 bool
1449
Changbin Du3be5cbc2019-12-06 17:03:48 -08001450menu "Debug kernel data structures"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451
Dave Jones199a9af2006-09-29 01:59:00 -07001452config DEBUG_LIST
1453 bool "Debug linked list manipulation"
Arnd Bergmann4520bcb2016-08-26 17:42:00 +02001454 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
Dave Jones199a9af2006-09-29 01:59:00 -07001455 help
1456 Enable this to turn on extended checks in the linked-list
1457 walking routines.
1458
1459 If unsure, say N.
1460
Davidlohr Bueso8e18fae2019-05-14 15:42:46 -07001461config DEBUG_PLIST
Dan Streetmanb8cfff62014-06-04 16:11:54 -07001462 bool "Debug priority linked list manipulation"
1463 depends on DEBUG_KERNEL
1464 help
1465 Enable this to turn on extended checks in the priority-ordered
1466 linked-list (plist) walking routines. This checks the entire
1467 list multiple times during each manipulation.
1468
1469 If unsure, say N.
1470
Jens Axboed6ec0842007-10-22 20:01:06 +02001471config DEBUG_SG
1472 bool "Debug SG table operations"
1473 depends on DEBUG_KERNEL
1474 help
1475 Enable this to turn on checks on scatter-gather tables. This can
1476 help find problems with drivers that do not properly initialize
1477 their sg tables.
1478
1479 If unsure, say N.
1480
Arjan van de Ven1b2439d2008-08-15 15:29:38 -07001481config DEBUG_NOTIFIERS
1482 bool "Debug notifier call chains"
1483 depends on DEBUG_KERNEL
1484 help
1485 Enable this to turn on sanity checking for notifier call chains.
1486 This is most useful for kernel developers to make sure that
1487 modules properly unregister themselves from notifier chains.
1488 This is a relatively cheap check but if you care about maximum
1489 performance, say N.
1490
Changbin Du3be5cbc2019-12-06 17:03:48 -08001491config BUG_ON_DATA_CORRUPTION
1492 bool "Trigger a BUG when data corruption is detected"
1493 select DEBUG_LIST
1494 help
1495 Select this option if the kernel should BUG when it encounters
1496 data corruption in kernel memory structures when they get checked
1497 for validity.
1498
1499 If unsure, say N.
1500
1501endmenu
1502
David Howellse0e81732009-09-02 09:13:40 +01001503config DEBUG_CREDENTIALS
1504 bool "Debug credential management"
1505 depends on DEBUG_KERNEL
1506 help
1507 Enable this to turn on some debug checking for credential
1508 management. The additional code keeps track of the number of
1509 pointers from task_structs to any given cred struct, and checks to
1510 see that this number never exceeds the usage count of the cred
1511 struct.
1512
1513 Furthermore, if SELinux is enabled, this also checks that the
1514 security pointer in the cred struct is never seen to be invalid.
1515
1516 If unsure, say N.
1517
Paul E. McKenney43a0a2a2017-05-17 09:19:44 -07001518source "kernel/rcu/Kconfig.debug"
Dave Hansen2f03e3c2013-01-07 08:19:23 -08001519
Tejun Heof303fccb2016-02-09 17:59:38 -05001520config DEBUG_WQ_FORCE_RR_CPU
1521 bool "Force round-robin CPU selection for unbound work items"
1522 depends on DEBUG_KERNEL
1523 default n
1524 help
1525 Workqueue used to implicitly guarantee that work items queued
1526 without explicit CPU specified are put on the local CPU. This
1527 guarantee is no longer true and while local CPU is still
1528 preferred work items may be put on foreign CPUs. Kernel
1529 parameter "workqueue.debug_force_rr_cpu" is added to force
1530 round-robin CPU selection to flush out usages which depend on the
1531 now broken guarantee. This config option enables the debug
1532 feature by default. When enabled, memory and cache locality will
1533 be impacted.
1534
Tejun Heo870d6652008-08-25 19:47:25 +09001535config DEBUG_BLOCK_EXT_DEVT
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -08001536 bool "Force extended block device numbers and spread them"
Tejun Heo870d6652008-08-25 19:47:25 +09001537 depends on DEBUG_KERNEL
1538 depends on BLOCK
Jens Axboe759f8ca2008-08-29 09:06:29 +02001539 default n
Tejun Heo870d6652008-08-25 19:47:25 +09001540 help
Tejun Heo0e11e342008-10-13 10:46:01 +02001541 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1542 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1543 YOU ARE DOING. Distros, please enable this and fix whatever
1544 is broken.
1545
Tejun Heo870d6652008-08-25 19:47:25 +09001546 Conventionally, block device numbers are allocated from
1547 predetermined contiguous area. However, extended block area
1548 may introduce non-contiguous block device numbers. This
1549 option forces most block device numbers to be allocated from
1550 the extended space and spreads them to discover kernel or
1551 userland code paths which assume predetermined contiguous
1552 device number allocation.
1553
Tejun Heo55dc7db2008-09-01 13:44:35 +02001554 Note that turning on this debug option shuffles all the
1555 device numbers for all IDE and SCSI devices including libata
1556 ones, so root partition specified using device number
1557 directly (via rdev or root=MAJ:MIN) won't work anymore.
1558 Textual device names (root=/dev/sdXn) will continue to work.
1559
Tejun Heo870d6652008-08-25 19:47:25 +09001560 Say N if you are unsure.
1561
Thomas Gleixner757c9892016-02-26 18:43:32 +00001562config CPU_HOTPLUG_STATE_CONTROL
1563 bool "Enable CPU hotplug state control"
1564 depends on DEBUG_KERNEL
1565 depends on HOTPLUG_CPU
1566 default n
1567 help
1568 Allows to write steps between "offline" and "online" to the CPUs
1569 sysfs target file so states can be stepped granular. This is a debug
1570 option for now as the hotplug machinery cannot be stopped and
1571 restarted at arbitrary points yet.
1572
1573 Say N if your are unsure.
1574
Changbin Du09a74952019-12-06 17:03:51 -08001575config LATENCYTOP
1576 bool "Latency measuring infrastructure"
1577 depends on DEBUG_KERNEL
1578 depends on STACKTRACE_SUPPORT
1579 depends on PROC_FS
1580 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1581 select KALLSYMS
1582 select KALLSYMS_ALL
1583 select STACKTRACE
1584 select SCHEDSTATS
1585 select SCHED_DEBUG
1586 help
1587 Enable this option if you want to use the LatencyTOP tool
1588 to find out which userspace is blocking on what kernel operations.
1589
1590source "kernel/trace/Kconfig"
1591
1592config PROVIDE_OHCI1394_DMA_INIT
1593 bool "Remote debugging over FireWire early on boot"
1594 depends on PCI && X86
1595 help
1596 If you want to debug problems which hang or crash the kernel early
1597 on boot and the crashing machine has a FireWire port, you can use
1598 this feature to remotely access the memory of the crashed machine
1599 over FireWire. This employs remote DMA as part of the OHCI1394
1600 specification which is now the standard for FireWire controllers.
1601
1602 With remote DMA, you can monitor the printk buffer remotely using
1603 firescope and access all memory below 4GB using fireproxy from gdb.
1604 Even controlling a kernel debugger is possible using remote DMA.
1605
1606 Usage:
1607
1608 If ohci1394_dma=early is used as boot parameter, it will initialize
1609 all OHCI1394 controllers which are found in the PCI config space.
1610
1611 As all changes to the FireWire bus such as enabling and disabling
1612 devices cause a bus reset and thereby disable remote DMA for all
1613 devices, be sure to have the cable plugged and FireWire enabled on
1614 the debugging host before booting the debug target for debugging.
1615
1616 This code (~1k) is freed after boot. By then, the firewire stack
1617 in charge of the OHCI-1394 controllers should be used instead.
1618
Mauro Carvalho Chehaba74e2a22020-05-01 17:37:50 +02001619 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
Changbin Du09a74952019-12-06 17:03:51 -08001620
Changbin Du045f6d72019-12-17 20:51:56 -08001621source "samples/Kconfig"
1622
Ingo Molnar28336be2019-12-30 08:10:51 +01001623source "lib/Kconfig.kcsan"
1624
Changbin Du045f6d72019-12-17 20:51:56 -08001625config ARCH_HAS_DEVMEM_IS_ALLOWED
1626 bool
1627
1628config STRICT_DEVMEM
1629 bool "Filter access to /dev/mem"
1630 depends on MMU && DEVMEM
1631 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1632 default y if PPC || X86 || ARM64
1633 help
1634 If this option is disabled, you allow userspace (root) access to all
1635 of memory, including kernel and userspace memory. Accidental
1636 access to this is obviously disastrous, but specific access can
1637 be used by people debugging the kernel. Note that with PAT support
1638 enabled, even in this case there are restrictions on /dev/mem
1639 use due to the cache aliasing requirements.
1640
1641 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1642 file only allows userspace access to PCI space and the BIOS code and
1643 data regions. This is sufficient for dosemu and X and all common
1644 users of /dev/mem.
1645
1646 If in doubt, say Y.
1647
1648config IO_STRICT_DEVMEM
1649 bool "Filter I/O access to /dev/mem"
1650 depends on STRICT_DEVMEM
1651 help
1652 If this option is disabled, you allow userspace (root) access to all
1653 io-memory regardless of whether a driver is actively using that
1654 range. Accidental access to this is obviously disastrous, but
1655 specific access can be used by people debugging kernel drivers.
1656
1657 If this option is switched on, the /dev/mem file only allows
1658 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1659 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1660 if the driver using a given range cannot be disabled.
1661
1662 If in doubt, say Y.
1663
1664menu "$(SRCARCH) Debugging"
1665
1666source "arch/$(SRCARCH)/Kconfig.debug"
1667
1668endmenu
1669
1670menu "Kernel Testing and Coverage"
1671
Changbin Du09a74952019-12-06 17:03:51 -08001672source "lib/kunit/Kconfig"
1673
Akinobu Mita8d438282012-07-30 14:43:02 -07001674config NOTIFIER_ERROR_INJECTION
1675 tristate "Notifier error injection"
1676 depends on DEBUG_KERNEL
1677 select DEBUG_FS
1678 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001679 This option provides the ability to inject artificial errors to
Akinobu Mita8d438282012-07-30 14:43:02 -07001680 specified notifier chain callbacks. It is useful to test the error
1681 handling of notifier call chain failures.
1682
1683 Say N if unsure.
1684
Akinobu Mita048b9c32012-07-30 14:43:07 -07001685config PM_NOTIFIER_ERROR_INJECT
1686 tristate "PM notifier error injection module"
1687 depends on PM && NOTIFIER_ERROR_INJECTION
1688 default m if PM_DEBUG
1689 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001690 This option provides the ability to inject artificial errors to
Akinobu Mita048b9c32012-07-30 14:43:07 -07001691 PM notifier chain callbacks. It is controlled through debugfs
1692 interface /sys/kernel/debug/notifier-error-inject/pm
1693
1694 If the notifier call chain should be failed with some events
1695 notified, write the error code to "actions/<notifier event>/error".
1696
1697 Example: Inject PM suspend error (-12 = -ENOMEM)
1698
1699 # cd /sys/kernel/debug/notifier-error-inject/pm/
1700 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1701 # echo mem > /sys/power/state
1702 bash: echo: write error: Cannot allocate memory
1703
1704 To compile this code as a module, choose M here: the module will
1705 be called pm-notifier-error-inject.
1706
1707 If unsure, say N.
1708
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001709config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1710 tristate "OF reconfig notifier error injection module"
1711 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001712 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001713 This option provides the ability to inject artificial errors to
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001714 OF reconfig notifier chain callbacks. It is controlled
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001715 through debugfs interface under
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001716 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001717
1718 If the notifier call chain should be failed with some events
1719 notified, write the error code to "actions/<notifier event>/error".
1720
1721 To compile this code as a module, choose M here: the module will
Akinobu Mitae12a95f2013-04-30 15:28:49 -07001722 be called of-reconfig-notifier-error-inject.
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001723
1724 If unsure, say N.
1725
Nikolay Aleksandrov02fff962015-11-28 13:45:28 +01001726config NETDEV_NOTIFIER_ERROR_INJECT
1727 tristate "Netdev notifier error injection module"
1728 depends on NET && NOTIFIER_ERROR_INJECTION
1729 help
1730 This option provides the ability to inject artificial errors to
1731 netdevice notifier chain callbacks. It is controlled through debugfs
1732 interface /sys/kernel/debug/notifier-error-inject/netdev
1733
1734 If the notifier call chain should be failed with some events
1735 notified, write the error code to "actions/<notifier event>/error".
1736
1737 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1738
1739 # cd /sys/kernel/debug/notifier-error-inject/netdev
1740 # echo -22 > actions/NETDEV_CHANGEMTU/error
1741 # ip link set eth0 mtu 1024
1742 RTNETLINK answers: Invalid argument
1743
1744 To compile this code as a module, choose M here: the module will
1745 be called netdev-notifier-error-inject.
1746
1747 If unsure, say N.
1748
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001749config FUNCTION_ERROR_INJECTION
1750 def_bool y
1751 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1752
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001753config FAULT_INJECTION
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001754 bool "Fault-injection framework"
1755 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -08001756 help
1757 Provide fault-injection framework.
1758 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001759
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001760config FAILSLAB
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001761 bool "Fault-injection capability for kmalloc"
1762 depends on FAULT_INJECTION
Akinobu Mita773ff602008-12-23 19:37:01 +09001763 depends on SLAB || SLUB
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001764 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001765 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001766
Akinobu Mita933e3122006-12-08 02:39:45 -08001767config FAIL_PAGE_ALLOC
Qiujun Huang29b46fa2020-04-06 20:12:49 -07001768 bool "Fault-injection capability for alloc_pages()"
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001769 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -08001770 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001771 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -08001772
Akinobu Mitac17bb492006-12-08 02:39:46 -08001773config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +01001774 bool "Fault-injection capability for disk IO"
Jens Axboe581d4e22008-09-14 05:56:33 -07001775 depends on FAULT_INJECTION && BLOCK
Akinobu Mitac17bb492006-12-08 02:39:46 -08001776 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001777 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -08001778
Jens Axboe581d4e22008-09-14 05:56:33 -07001779config FAIL_IO_TIMEOUT
Takuya Yoshikawaf4d01432010-07-21 16:05:53 +09001780 bool "Fault-injection capability for faking disk interrupts"
Jens Axboe581d4e22008-09-14 05:56:33 -07001781 depends on FAULT_INJECTION && BLOCK
1782 help
1783 Provide fault-injection capability on end IO handling. This
1784 will make the block layer "forget" an interrupt as configured,
1785 thus exercising the error handling.
1786
1787 Only works with drivers that use the generic timeout handling,
1788 for others it wont do anything.
1789
Davidlohr Buesoab51fba2015-06-29 23:26:02 -07001790config FAIL_FUTEX
1791 bool "Fault-injection capability for futexes"
1792 select DEBUG_FS
1793 depends on FAULT_INJECTION && FUTEX
1794 help
1795 Provide fault-injection capability for futexes.
1796
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001797config FAULT_INJECTION_DEBUG_FS
1798 bool "Debugfs entries for fault-injection capabilities"
1799 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1800 help
1801 Enable configuration of fault-injection capabilities via debugfs.
1802
Masami Hiramatsu4b1a29a2018-01-13 02:56:03 +09001803config FAIL_FUNCTION
1804 bool "Fault-injection capability for functions"
1805 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1806 help
1807 Provide function-based fault-injection capability.
1808 This will allow you to override a specific function with a return
1809 with given return value. As a result, function caller will see
1810 an error value and have to handle it. This is useful to test the
1811 error handling in various subsystems.
1812
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001813config FAIL_MMC_REQUEST
1814 bool "Fault-injection capability for MMC IO"
1815 depends on FAULT_INJECTION_DEBUG_FS && MMC
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001816 help
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001817 Provide fault-injection capability for MMC IO.
1818 This will make the mmc core return data errors. This is
1819 useful to test the error handling in the mmc block device
1820 and to test how the mmc host driver handles retries from
1821 the block device.
Akinobu Mita1df49002007-02-20 13:57:56 -08001822
1823config FAULT_INJECTION_STACKTRACE_FILTER
1824 bool "stacktrace filter for fault-injection capabilities"
1825 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -07001826 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -08001827 select STACKTRACE
Stefan Agnerf9b58e82018-09-30 23:02:33 +01001828 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
Akinobu Mita1df49002007-02-20 13:57:56 -08001829 help
1830 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -07001831
Changbin Du09a74952019-12-06 17:03:51 -08001832config ARCH_HAS_KCOV
1833 bool
Arjan van de Ven97455122008-01-25 21:08:34 +01001834 help
Changbin Du09a74952019-12-06 17:03:51 -08001835 An architecture should select this when it can successfully
1836 build and run with CONFIG_KCOV. This typically requires
1837 disabling instrumentation for some early boot code.
Arjan van de Ven97455122008-01-25 21:08:34 +01001838
Changbin Du09a74952019-12-06 17:03:51 -08001839config CC_HAS_SANCOV_TRACE_PC
1840 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001841
Changbin Du09a74952019-12-06 17:03:51 -08001842
1843config KCOV
1844 bool "Code coverage for fuzzing"
1845 depends on ARCH_HAS_KCOV
1846 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1847 select DEBUG_FS
1848 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001849 help
Changbin Du09a74952019-12-06 17:03:51 -08001850 KCOV exposes kernel code coverage information in a form suitable
1851 for coverage-guided fuzzing (randomized testing).
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001852
Changbin Du09a74952019-12-06 17:03:51 -08001853 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1854 different machines and across reboots. If you need stable PC values,
1855 disable RANDOMIZE_BASE.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001856
Changbin Du09a74952019-12-06 17:03:51 -08001857 For more details, see Documentation/dev-tools/kcov.rst.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001858
Changbin Du09a74952019-12-06 17:03:51 -08001859config KCOV_ENABLE_COMPARISONS
1860 bool "Enable comparison operands collection by KCOV"
1861 depends on KCOV
1862 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1863 help
1864 KCOV also exposes operands of every comparison in the instrumented
1865 code along with operand sizes and PCs of the comparison instructions.
1866 These operands can be used by fuzzing engines to improve the quality
1867 of fuzzing coverage.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001868
Changbin Du09a74952019-12-06 17:03:51 -08001869config KCOV_INSTRUMENT_ALL
1870 bool "Instrument all code by default"
1871 depends on KCOV
1872 default y
1873 help
1874 If you are doing generic system call fuzzing (like e.g. syzkaller),
1875 then you will want to instrument the whole kernel and you should
1876 say y here. If you are doing more targeted fuzzing (like e.g.
1877 filesystem fuzzing with AFL) then you will want to enable coverage
1878 for more specific subsets of files, and should say n here.
Brendan Higgins84bc8092019-09-23 02:02:36 -07001879
Andrey Konovalov5ff3b302020-06-04 16:46:04 -07001880config KCOV_IRQ_AREA_SIZE
1881 hex "Size of interrupt coverage collection area in words"
1882 depends on KCOV
1883 default 0x40000
1884 help
1885 KCOV uses preallocated per-cpu areas to collect coverage from
1886 soft interrupts. This specifies the size of those areas in the
1887 number of unsigned long words.
1888
Vincent Legolld3deafa2018-02-06 15:38:38 -08001889menuconfig RUNTIME_TESTING_MENU
1890 bool "Runtime Testing"
Anders Roxell908009e82018-02-21 14:46:05 -08001891 def_bool y
Vincent Legolld3deafa2018-02-06 15:38:38 -08001892
1893if RUNTIME_TESTING_MENU
Dave Hansen881c5142013-07-01 13:04:44 -07001894
1895config LKDTM
1896 tristate "Linux Kernel Dump Test Tool Module"
1897 depends on DEBUG_FS
Dave Hansen881c5142013-07-01 13:04:44 -07001898 help
1899 This module enables testing of the different dumping mechanisms by
1900 inducing system failures at predefined crash points.
1901 If you don't need it: say N
1902 Choose M here to compile this code as a module. The module will be
1903 called lkdtm.
1904
1905 Documentation on how to use the module can be found in
Mauro Carvalho Chehab10ffebb2019-06-12 14:52:44 -03001906 Documentation/fault-injection/provoke-crashes.rst
Dave Hansen881c5142013-07-01 13:04:44 -07001907
1908config TEST_LIST_SORT
Geert Uytterhoevene327fd72017-05-08 15:55:26 -07001909 tristate "Linked list sorting test"
1910 depends on DEBUG_KERNEL || m
Dave Hansen881c5142013-07-01 13:04:44 -07001911 help
1912 Enable this to turn on 'list_sort()' function test. This test is
Geert Uytterhoevene327fd72017-05-08 15:55:26 -07001913 executed only once during system boot (so affects only boot time),
1914 or at module load time.
Dave Hansen881c5142013-07-01 13:04:44 -07001915
1916 If unsure, say N.
1917
Ian Rogers6e246282020-02-13 23:51:29 -08001918config TEST_MIN_HEAP
1919 tristate "Min heap test"
1920 depends on DEBUG_KERNEL || m
1921 help
1922 Enable this to turn on min heap function tests. This test is
1923 executed only once during system boot (so affects only boot time),
1924 or at module load time.
1925
1926 If unsure, say N.
1927
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001928config TEST_SORT
Geert Uytterhoeven5c4e6792017-05-08 15:55:23 -07001929 tristate "Array-based sort test"
1930 depends on DEBUG_KERNEL || m
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001931 help
Geert Uytterhoeven5c4e6792017-05-08 15:55:23 -07001932 This option enables the self-test function of 'sort()' at boot,
1933 or at module load time.
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001934
1935 If unsure, say N.
1936
Dave Hansen881c5142013-07-01 13:04:44 -07001937config KPROBES_SANITY_TEST
1938 bool "Kprobes sanity tests"
1939 depends on DEBUG_KERNEL
1940 depends on KPROBES
Dave Hansen881c5142013-07-01 13:04:44 -07001941 help
1942 This option provides for testing basic kprobes functionality on
Masami Hiramatsu5a6cf772018-06-20 01:05:07 +09001943 boot. Samples of kprobe and kretprobe are inserted and
Dave Hansen881c5142013-07-01 13:04:44 -07001944 verified for functionality.
1945
1946 Say N if you are unsure.
1947
1948config BACKTRACE_SELF_TEST
1949 tristate "Self test for the backtrace code"
1950 depends on DEBUG_KERNEL
Dave Hansen881c5142013-07-01 13:04:44 -07001951 help
1952 This option provides a kernel module that can be used to test
1953 the kernel stack backtrace code. This option is not useful
1954 for distributions or general kernels, but only for kernel
1955 developers working on architecture code.
1956
1957 Note that if you want to also test saved backtraces, you will
1958 have to enable STACKTRACE as well.
1959
1960 Say N if you are unsure.
1961
Michel Lespinasse910a7422012-10-08 16:30:39 -07001962config RBTREE_TEST
1963 tristate "Red-Black tree test"
Cody P Schafer7c993e12013-09-11 14:25:19 -07001964 depends on DEBUG_KERNEL
Michel Lespinasse910a7422012-10-08 16:30:39 -07001965 help
1966 A benchmark measuring the performance of the rbtree library.
1967 Also includes rbtree invariant checks.
1968
Ferdinand Blomqvist4b4f3ac2019-06-20 17:10:33 +03001969config REED_SOLOMON_TEST
1970 tristate "Reed-Solomon library test"
1971 depends on DEBUG_KERNEL || m
1972 select REED_SOLOMON
1973 select REED_SOLOMON_ENC16
1974 select REED_SOLOMON_DEC16
1975 help
1976 This option enables the self-test function of rslib at boot,
1977 or at module load time.
1978
1979 If unsure, say N.
1980
Michel Lespinassefff3fd82012-10-08 16:31:23 -07001981config INTERVAL_TREE_TEST
1982 tristate "Interval tree test"
Davidlohr Bueso0f789b62017-07-10 15:51:43 -07001983 depends on DEBUG_KERNEL
Chris Wilsona88cc102014-03-17 12:21:54 +00001984 select INTERVAL_TREE
Michel Lespinassefff3fd82012-10-08 16:31:23 -07001985 help
1986 A benchmark measuring the performance of the interval tree library
1987
Greg Thelen623fd802013-11-12 15:08:34 -08001988config PERCPU_TEST
1989 tristate "Per cpu operations test"
1990 depends on m && DEBUG_KERNEL
1991 help
1992 Enable this option to build test module which validates per-cpu
1993 operations.
1994
1995 If unsure, say N.
1996
Dave Hansen881c5142013-07-01 13:04:44 -07001997config ATOMIC64_SELFTEST
Geert Uytterhoeven55ded952017-02-24 15:00:55 -08001998 tristate "Perform an atomic64_t self-test"
Dave Hansen881c5142013-07-01 13:04:44 -07001999 help
Geert Uytterhoeven55ded952017-02-24 15:00:55 -08002000 Enable this option to test the atomic64_t functions at boot or
2001 at module load time.
Dave Hansen881c5142013-07-01 13:04:44 -07002002
2003 If unsure, say N.
2004
2005config ASYNC_RAID6_TEST
2006 tristate "Self test for hardware accelerated raid6 recovery"
2007 depends on ASYNC_RAID6_RECOV
2008 select ASYNC_MEMCPY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002009 help
Dave Hansen881c5142013-07-01 13:04:44 -07002010 This is a one-shot self test that permutes through the
2011 recovery of all the possible two disk failure scenarios for a
2012 N-disk array. Recovery is performed with the asynchronous
2013 raid6 recovery routines, and will optionally use an offload
2014 engine if one is available.
2015
2016 If unsure, say N.
2017
Andy Shevchenko64d1d772015-02-12 15:02:21 -08002018config TEST_HEXDUMP
2019 tristate "Test functions located in the hexdump module at runtime"
2020
Dave Hansen881c5142013-07-01 13:04:44 -07002021config TEST_STRING_HELPERS
2022 tristate "Test functions located in the string_helpers module at runtime"
2023
Tobin C. Harding0b0600c82019-04-05 12:58:59 +11002024config TEST_STRSCPY
2025 tristate "Test strscpy*() family of functions at runtime"
2026
Dave Hansen881c5142013-07-01 13:04:44 -07002027config TEST_KSTRTOX
2028 tristate "Test kstrto*() family of functions at runtime"
2029
Rasmus Villemoes707cc722015-11-06 16:30:29 -08002030config TEST_PRINTF
2031 tristate "Test printf() family of functions at runtime"
2032
David Decotigny5fd003f2016-02-19 09:24:00 -05002033config TEST_BITMAP
2034 tristate "Test bitmap_*() family of functions at runtime"
David Decotigny5fd003f2016-02-19 09:24:00 -05002035 help
2036 Enable this option to test the bitmap functions at boot.
2037
2038 If unsure, say N.
2039
Johannes Berg0e2dc702018-06-20 08:58:30 +02002040config TEST_BITFIELD
2041 tristate "Test bitfield functions at runtime"
2042 help
2043 Enable this option to test the bitfield functions at boot.
2044
2045 If unsure, say N.
2046
Andy Shevchenkocfaff0e2016-05-30 17:40:41 +03002047config TEST_UUID
2048 tristate "Test functions located in the uuid module at runtime"
2049
Matthew Wilcoxad3d6c72017-11-07 14:57:46 -05002050config TEST_XARRAY
2051 tristate "Test the XArray code at runtime"
2052
Rasmus Villemoes455a35a2018-05-08 00:36:28 +02002053config TEST_OVERFLOW
2054 tristate "Test check_*_overflow() functions at runtime"
2055
Thomas Graf7e1e7762014-08-02 11:47:44 +02002056config TEST_RHASHTABLE
Geert Uytterhoeven9d6dbe12015-01-29 15:40:25 +01002057 tristate "Perform selftest on resizable hash table"
Thomas Graf7e1e7762014-08-02 11:47:44 +02002058 help
2059 Enable this option to test the rhashtable functions at boot.
2060
2061 If unsure, say N.
2062
George Spelvin468a9422016-05-26 22:11:51 -04002063config TEST_HASH
2064 tristate "Perform selftest on hash functions"
George Spelvin468a9422016-05-26 22:11:51 -04002065 help
Jason A. Donenfeld2c956a62017-01-08 13:54:00 +01002066 Enable this option to test the kernel's integer (<linux/hash.h>),
2067 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2068 hash functions on boot (or module load).
George Spelvin468a9422016-05-26 22:11:51 -04002069
2070 This is intended to help people writing architecture-specific
2071 optimized versions. If unsure, say N.
2072
Matthew Wilcox8ab8ba32018-06-18 16:59:29 -04002073config TEST_IDA
2074 tristate "Perform selftest on IDA functions"
2075
Jiri Pirko44091d22017-02-03 10:29:06 +01002076config TEST_PARMAN
2077 tristate "Perform selftest on priority array manager"
Jiri Pirko44091d22017-02-03 10:29:06 +01002078 depends on PARMAN
2079 help
2080 Enable this option to test priority array manager on boot
2081 (or module load).
2082
2083 If unsure, say N.
2084
Daniel Lezcano6aed82d2019-05-27 22:55:19 +02002085config TEST_IRQ_TIMINGS
2086 bool "IRQ timings selftest"
2087 depends on IRQ_TIMINGS
2088 help
2089 Enable this option to test the irq timings code on boot.
2090
2091 If unsure, say N.
2092
Valentin Rothberg8a6f0b42014-10-13 15:51:38 -07002093config TEST_LKM
Kees Cook93e9ef82014-01-23 15:54:37 -08002094 tristate "Test module loading with 'hello world' module"
Kees Cook93e9ef82014-01-23 15:54:37 -08002095 depends on m
2096 help
2097 This builds the "test_module" module that emits "Hello, world"
2098 on printk when loaded. It is designed to be used for basic
2099 evaluation of the module loading subsystem (for example when
2100 validating module verification). It lacks any extra dependencies,
2101 and will not normally be loaded by the system unless explicitly
2102 requested by name.
2103
2104 If unsure, say N.
2105
Jesse Brandeburgc348c162020-06-04 16:50:27 -07002106config TEST_BITOPS
Wei Yang6af132f2020-06-10 18:41:53 -07002107 tristate "Test module for compilation of bitops operations"
Jesse Brandeburgc348c162020-06-04 16:50:27 -07002108 depends on m
2109 help
2110 This builds the "test_bitops" module that is much like the
2111 TEST_LKM module except that it does a basic exercise of the
Wei Yang6af132f2020-06-10 18:41:53 -07002112 set/clear_bit macros and get_count_order/long to make sure there are
2113 no compiler warnings from C=1 sparse checker or -Wextra
2114 compilations. It has no dependencies and doesn't run or load unless
2115 explicitly requested by name. for example: modprobe test_bitops.
Jesse Brandeburgc348c162020-06-04 16:50:27 -07002116
2117 If unsure, say N.
2118
Uladzislau Rezki (Sony)3f21a6b2019-03-05 15:43:34 -08002119config TEST_VMALLOC
2120 tristate "Test module for stress/performance analysis of vmalloc allocator"
2121 default n
2122 depends on MMU
2123 depends on m
2124 help
2125 This builds the "test_vmalloc" module that should be used for
2126 stress and performance analysis. So, any new change for vmalloc
2127 subsystem can be evaluated from performance and stability point
2128 of view.
2129
2130 If unsure, say N.
2131
Kees Cook3e2a4c12014-01-23 15:54:38 -08002132config TEST_USER_COPY
2133 tristate "Test user/kernel boundary protections"
Kees Cook3e2a4c12014-01-23 15:54:38 -08002134 depends on m
2135 help
2136 This builds the "test_user_copy" module that runs sanity checks
2137 on the copy_to/from_user infrastructure, making sure basic
2138 user/kernel boundary testing is working. If it fails to load,
2139 a regression has been detected in the user/kernel memory boundary
2140 protections.
2141
2142 If unsure, say N.
2143
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002144config TEST_BPF
2145 tristate "Test BPF filter functionality"
Randy Dunlap98920ba2014-05-13 09:58:44 -07002146 depends on m && NET
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002147 help
2148 This builds the "test_bpf" module that runs various test vectors
2149 against the BPF interpreter or BPF JIT compiler depending on the
2150 current setting. This is in particular useful for BPF JIT compiler
2151 development, but also to run regression tests against changes in
Alexei Starovoitov3c731eb2014-09-26 00:17:07 -07002152 the interpreter code. It also enables test stubs for eBPF maps and
2153 verifier used by user space verifier testsuite.
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002154
2155 If unsure, say N.
2156
Mahesh Bandewar509e56b2019-07-01 14:39:01 -07002157config TEST_BLACKHOLE_DEV
2158 tristate "Test blackhole netdev functionality"
2159 depends on m && NET
2160 help
2161 This builds the "test_blackhole_dev" module that validates the
2162 data path through this blackhole netdev.
2163
2164 If unsure, say N.
2165
Yury Norovdceeb3e2018-02-06 15:38:27 -08002166config FIND_BIT_BENCHMARK
Yury Norov4441fca2017-11-17 15:28:31 -08002167 tristate "Test find_bit functions"
Yury Norov4441fca2017-11-17 15:28:31 -08002168 help
2169 This builds the "test_find_bit" module that measure find_*_bit()
2170 functions performance.
2171
2172 If unsure, say N.
2173
Kees Cook0a8adf52014-07-14 14:38:12 -07002174config TEST_FIRMWARE
2175 tristate "Test firmware loading via userspace interface"
Kees Cook0a8adf52014-07-14 14:38:12 -07002176 depends on FW_LOADER
2177 help
2178 This builds the "test_firmware" module that creates a userspace
2179 interface for testing firmware loading. This can be used to
2180 control the triggering of firmware loading without needing an
2181 actual firmware-using device. The contents can be rechecked by
2182 userspace.
2183
2184 If unsure, say N.
2185
Luis R. Rodriguez9308f2f2017-07-12 14:33:43 -07002186config TEST_SYSCTL
2187 tristate "sysctl test driver"
Luis R. Rodriguez9308f2f2017-07-12 14:33:43 -07002188 depends on PROC_SYSCTL
2189 help
2190 This builds the "test_sysctl" module. This driver enables to test the
2191 proc sysctl interfaces available to drivers safely without affecting
2192 production knobs which might alter system functionality.
2193
2194 If unsure, say N.
2195
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002196config SYSCTL_KUNIT_TEST
Anders Roxell5f215aab2020-05-11 15:14:29 +02002197 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002198 depends on KUNIT
Anders Roxell5f215aab2020-05-11 15:14:29 +02002199 default KUNIT_ALL_TESTS
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002200 help
2201 This builds the proc sysctl unit test, which runs on boot.
2202 Tests the API contract and implementation correctness of sysctl.
2203 For more information on KUnit and unit tests in general please refer
2204 to the KUnit documentation in Documentation/dev-tools/kunit/.
2205
2206 If unsure, say N.
2207
David Gowea2dd7c2019-10-24 15:46:31 -07002208config LIST_KUNIT_TEST
Anders Roxell5f215aab2020-05-11 15:14:29 +02002209 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
David Gowea2dd7c2019-10-24 15:46:31 -07002210 depends on KUNIT
Anders Roxell5f215aab2020-05-11 15:14:29 +02002211 default KUNIT_ALL_TESTS
David Gowea2dd7c2019-10-24 15:46:31 -07002212 help
2213 This builds the linked list KUnit test suite.
2214 It tests that the API and basic functionality of the list_head type
2215 and associated macros.
2216
2217 KUnit tests run during boot and output the results to the debug log
2218 in TAP format (http://testanything.org/). Only useful for kernel devs
2219 running the KUnit test harness, and not intended for inclusion into a
2220 production build.
2221
2222 For more information on KUnit and unit tests in general please refer
2223 to the KUnit documentation in Documentation/dev-tools/kunit/.
2224
2225 If unsure, say N.
2226
Matti Vaittinen33d599f2020-05-08 18:40:43 +03002227config LINEAR_RANGES_TEST
2228 tristate "KUnit test for linear_ranges"
2229 depends on KUNIT
2230 select LINEAR_RANGES
2231 help
2232 This builds the linear_ranges unit test, which runs on boot.
2233 Tests the linear_ranges logic correctness.
2234 For more information on KUnit and unit tests in general please refer
2235 to the KUnit documentation in Documentation/dev-tools/kunit/.
2236
2237 If unsure, say N.
2238
David Rileye704f932014-06-16 14:58:32 -07002239config TEST_UDELAY
2240 tristate "udelay test driver"
David Rileye704f932014-06-16 14:58:32 -07002241 help
2242 This builds the "udelay_test" module that helps to make sure
2243 that udelay() is working properly.
2244
2245 If unsure, say N.
2246
Ingo Molnar2bf9e0a2015-08-03 11:42:57 +02002247config TEST_STATIC_KEYS
2248 tristate "Test static keys"
Jason Baron579e1ac2015-07-30 03:59:44 +00002249 depends on m
2250 help
Ingo Molnar2bf9e0a2015-08-03 11:42:57 +02002251 Test the static key interfaces.
Jason Baron579e1ac2015-07-30 03:59:44 +00002252
2253 If unsure, say N.
2254
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002255config TEST_KMOD
2256 tristate "kmod stress tester"
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002257 depends on m
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002258 depends on NETDEVICES && NET_CORE && INET # for TUN
YueHaibingae3d6a32019-04-25 22:23:44 -07002259 depends on BLOCK
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002260 select TEST_LKM
2261 select XFS_FS
2262 select TUN
2263 select BTRFS_FS
2264 help
2265 Test the kernel's module loading mechanism: kmod. kmod implements
2266 support to load modules using the Linux kernel's usermode helper.
2267 This test provides a series of tests against kmod.
2268
2269 Although technically you can either build test_kmod as a module or
2270 into the kernel we disallow building it into the kernel since
2271 it stress tests request_module() and this will very likely cause
2272 some issues by taking over precious threads available from other
2273 module load requests, ultimately this could be fatal.
2274
2275 To run tests run:
2276
2277 tools/testing/selftests/kmod/kmod.sh --help
2278
2279 If unsure, say N.
2280
Florian Fainellie4dace32017-09-08 16:15:31 -07002281config TEST_DEBUG_VIRTUAL
2282 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2283 depends on DEBUG_VIRTUAL
2284 help
2285 Test the kernel's ability to detect incorrect calls to
2286 virt_to_phys() done against the non-linear part of the
2287 kernel's virtual address map.
2288
2289 If unsure, say N.
2290
Alexander Shishkince76d932018-10-05 15:43:05 +03002291config TEST_MEMCAT_P
2292 tristate "Test memcat_p() helper function"
2293 help
2294 Test the memcat_p() helper for correctly merging two
2295 pointer arrays together.
2296
2297 If unsure, say N.
2298
Joe Lawrencea2818ee2019-01-09 13:43:29 +01002299config TEST_LIVEPATCH
2300 tristate "Test livepatching"
2301 default n
Joe Lawrencebae05432019-01-31 11:41:24 -05002302 depends on DYNAMIC_DEBUG
Joe Lawrencea2818ee2019-01-09 13:43:29 +01002303 depends on LIVEPATCH
2304 depends on m
2305 help
2306 Test kernel livepatching features for correctness. The tests will
2307 load test modules that will be livepatched in various scenarios.
2308
2309 To run all the livepatching tests:
2310
2311 make -C tools/testing/selftests TARGETS=livepatch run_tests
2312
2313 Alternatively, individual tests may be invoked:
2314
2315 tools/testing/selftests/livepatch/test-callbacks.sh
2316 tools/testing/selftests/livepatch/test-livepatch.sh
2317 tools/testing/selftests/livepatch/test-shadow-vars.sh
2318
2319 If unsure, say N.
2320
Jiri Pirko0a020d42018-11-14 08:22:28 +00002321config TEST_OBJAGG
2322 tristate "Perform selftest on object aggreration manager"
2323 default n
2324 depends on OBJAGG
2325 help
2326 Enable this option to test object aggregation manager on boot
2327 (or module load).
2328
Jiri Pirko0a020d42018-11-14 08:22:28 +00002329
Kees Cook50ceaa95e2019-01-23 12:24:32 -07002330config TEST_STACKINIT
2331 tristate "Test level of stack variable initialization"
2332 help
2333 Test if the kernel is zero-initializing stack variables and
2334 padding. Coverage is controlled by compiler flags,
2335 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2336 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2337
2338 If unsure, say N.
2339
Alexander Potapenko5015a302019-07-16 16:27:27 -07002340config TEST_MEMINIT
2341 tristate "Test heap/page initialization"
2342 help
2343 Test if the kernel is zero-initializing heap and page allocations.
2344 This can be useful to test init_on_alloc and init_on_free features.
2345
2346 If unsure, say N.
2347
Ralph Campbellb2ef9f52020-04-22 12:50:26 -07002348config TEST_HMM
2349 tristate "Test HMM (Heterogeneous Memory Management)"
2350 depends on TRANSPARENT_HUGEPAGE
2351 depends on DEVICE_PRIVATE
2352 select HMM_MIRROR
2353 select MMU_NOTIFIER
2354 help
2355 This is a pseudo device driver solely for testing HMM.
2356 Say M here if you want to build the HMM test module.
2357 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2358
2359 If unsure, say N.
2360
Petteri Aimonen4185b3b2020-06-18 16:37:37 +02002361config TEST_FPU
2362 tristate "Test floating point operations in kernel space"
2363 depends on X86 && !KCOV_INSTRUMENT_ALL
2364 help
2365 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2366 which will trigger a sequence of floating point operations. This is used
2367 for self-testing floating point control register setting in
2368 kernel_fpu_begin().
2369
2370 If unsure, say N.
2371
Vincent Legolld3deafa2018-02-06 15:38:38 -08002372endif # RUNTIME_TESTING_MENU
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002373
2374config MEMTEST
2375 bool "Memtest"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002376 help
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002377 This option adds a kernel parameter 'memtest', which allows memtest
2378 to be set.
2379 memtest=0, mean disabled; -- default
2380 memtest=1, mean do 1 test pattern;
2381 ...
2382 memtest=17, mean do 17 test patterns.
2383 If you are unsure how to answer this question, answer N.
2384
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002385
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002386
Branden Bonabyaf9ca6f2019-10-03 17:01:49 -04002387config HYPERV_TESTING
2388 bool "Microsoft Hyper-V driver testing"
2389 default n
2390 depends on HYPERV && DEBUG_FS
2391 help
2392 Select this option to enable Hyper-V vmbus testing.
2393
Changbin Du045f6d72019-12-17 20:51:56 -08002394endmenu # "Kernel Testing and Coverage"
2395
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002396endmenu # Kernel hacking