blob: 0217ed126f77775273bb503b54510d728025025a [file] [log] [blame]
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)
Dave Hansen604ff0d2013-07-01 13:04:49 -0700102 help
103
104 Compiles debug level messages into the kernel, which would not
105 otherwise be available at runtime. These messages can then be
106 enabled/disabled based on various levels of scope - per source file,
107 function, module, format string, and line number. This mechanism
108 implicitly compiles in all pr_debug() and dev_dbg() calls, which
109 enlarges the kernel text size by about 2%.
110
111 If a source file is compiled with DEBUG flag set, any
112 pr_debug() calls in it are enabled by default, but can be
113 disabled at runtime as below. Note that DEBUG flag is
114 turned on by many CONFIG_*DEBUG* options.
115
116 Usage:
117
118 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
Greg Kroah-Hartman239a5792020-02-10 13:11:42 -0800119 which is contained in the 'debugfs' filesystem or procfs.
120 Thus, the debugfs or procfs filesystem must first be mounted before
121 making use of this feature.
Dave Hansen604ff0d2013-07-01 13:04:49 -0700122 We refer the control file as: <debugfs>/dynamic_debug/control. This
123 file contains a list of the debug statements that can be enabled. The
124 format for each line of the file is:
125
126 filename:lineno [module]function flags format
127
128 filename : source file of the debug statement
129 lineno : line number of the debug statement
130 module : module that contains the debug statement
131 function : function that contains the debug statement
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800132 flags : '=p' means the line is turned 'on' for printing
133 format : the format used for the debug statement
Dave Hansen604ff0d2013-07-01 13:04:49 -0700134
135 From a live system:
136
137 nullarbor:~ # cat <debugfs>/dynamic_debug/control
138 # filename:lineno [module]function flags format
139 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
140 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
141 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
142
143 Example usage:
144
145 // enable the message at line 1603 of file svcsock.c
146 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
147 <debugfs>/dynamic_debug/control
148
149 // enable all the messages in file svcsock.c
150 nullarbor:~ # echo -n 'file svcsock.c +p' >
151 <debugfs>/dynamic_debug/control
152
153 // enable all the messages in the NFS server module
154 nullarbor:~ # echo -n 'module nfsd +p' >
155 <debugfs>/dynamic_debug/control
156
157 // enable all 12 messages in the function svc_process()
158 nullarbor:~ # echo -n 'func svc_process +p' >
159 <debugfs>/dynamic_debug/control
160
161 // disable all 12 messages in the function svc_process()
162 nullarbor:~ # echo -n 'func svc_process -p' >
163 <debugfs>/dynamic_debug/control
164
Hans Holmbergf8998c22017-03-16 09:37:32 +0100165 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
166 information.
Dave Hansen604ff0d2013-07-01 13:04:49 -0700167
Rasmus Villemoes57f56772019-10-15 21:07:05 +0200168config SYMBOLIC_ERRNAME
169 bool "Support symbolic error names in printf"
170 default y if PRINTK
171 help
172 If you say Y here, the kernel's printf implementation will
173 be able to print symbolic error names such as ENOSPC instead
174 of the number 28. It makes the kernel image slightly larger
175 (about 3KB), but can make the kernel logs easier to read.
176
Changbin Du2b05bb72019-12-06 17:04:03 -0800177config DEBUG_BUGVERBOSE
178 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
179 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
180 default y
181 help
182 Say Y here to make BUG() panics output the file name and line number
183 of the BUG call as well as the EIP and oops trace. This aids
184 debugging but costs about 70-100K of memory.
185
Dave Hansen604ff0d2013-07-01 13:04:49 -0700186endmenu # "printk and dmesg options"
187
Dave Hansen6dfc0662013-07-01 13:04:46 -0700188menu "Compile-time checks and compiler options"
189
190config DEBUG_INFO
191 bool "Compile the kernel with debug info"
Linus Torvalds12b13832014-02-04 12:20:01 -0800192 depends on DEBUG_KERNEL && !COMPILE_TEST
Dave Hansen6dfc0662013-07-01 13:04:46 -0700193 help
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800194 If you say Y here the resulting kernel image will include
Dave Hansen6dfc0662013-07-01 13:04:46 -0700195 debugging info resulting in a larger kernel image.
196 This adds debug symbols to the kernel and modules (gcc -g), and
197 is needed if you intend to use kernel crashdump or binary object
198 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
199 Say Y here only if you plan to debug the kernel.
200
201 If unsure, say N.
202
203config DEBUG_INFO_REDUCED
204 bool "Reduce debugging information"
205 depends on DEBUG_INFO
206 help
207 If you say Y here gcc is instructed to generate less debugging
208 information for structure types. This means that tools that
209 need full debugging information (like kgdb or systemtap) won't
210 be happy. But if you merely need debugging information to
211 resolve line numbers there is no loss. Advantage is that
212 build directory object sizes shrink dramatically over a full
213 DEBUG_INFO build and compile times are reduced too.
214 Only works with newer gcc versions.
215
Andi Kleen866ced92014-07-30 20:50:18 +0200216config DEBUG_INFO_SPLIT
217 bool "Produce split debuginfo in .dwo files"
Arnd Bergmanna687a532018-03-07 23:30:54 +0100218 depends on DEBUG_INFO
Masahiro Yamada9d937442019-02-22 16:56:09 +0900219 depends on $(cc-option,-gsplit-dwarf)
Andi Kleen866ced92014-07-30 20:50:18 +0200220 help
221 Generate debug info into separate .dwo files. This significantly
222 reduces the build directory size for builds with DEBUG_INFO,
223 because it stores the information only once on disk in .dwo
224 files instead of multiple times in object files and executables.
225 In addition the debug information is also compressed.
226
227 Requires recent gcc (4.7+) and recent gdb/binutils.
228 Any tool that packages or reads debug information would need
229 to know about the .dwo files and include them.
230 Incompatible with older versions of ccache.
231
Andi Kleenbfaf2dd2014-07-30 20:50:19 +0200232config DEBUG_INFO_DWARF4
233 bool "Generate dwarf4 debuginfo"
234 depends on DEBUG_INFO
Masahiro Yamada9d937442019-02-22 16:56:09 +0900235 depends on $(cc-option,-gdwarf-4)
Andi Kleenbfaf2dd2014-07-30 20:50:19 +0200236 help
237 Generate dwarf4 debug info. This requires recent versions
238 of gcc and gdb. It makes the debug information larger.
239 But it significantly improves the success of resolving
240 variables in gdb on optimized code.
241
Andrii Nakryikoe83b9f52019-04-02 09:49:50 -0700242config DEBUG_INFO_BTF
243 bool "Generate BTF typeinfo"
244 depends on DEBUG_INFO
Slava Bacherikov7d32e692020-04-02 23:41:39 +0300245 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
246 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
Andrii Nakryikoe83b9f52019-04-02 09:49:50 -0700247 help
248 Generate deduplicated BTF type information from DWARF debug info.
249 Turning this on expects presence of pahole tool, which will convert
250 DWARF type info into equivalent deduplicated BTF type info.
251
Jan Kiszka3ee7b3f2015-02-17 13:46:36 -0800252config GDB_SCRIPTS
253 bool "Provide GDB scripts for kernel debugging"
254 depends on DEBUG_INFO
255 help
256 This creates the required links to GDB helper scripts in the
257 build directory. If you load vmlinux into gdb, the helper
258 scripts will be automatically imported by gdb as well, and
259 additional functions are available to analyze a Linux kernel
Andreas Platschek700199b02016-12-14 15:05:40 -0800260 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
261 for further details.
Jan Kiszka3ee7b3f2015-02-17 13:46:36 -0800262
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700263config ENABLE_MUST_CHECK
264 bool "Enable __must_check logic"
265 default y
266 help
267 Enable the __must_check logic in the kernel build. Disable this to
268 suppress the "warning: ignoring return value of 'foo', declared with
269 attribute warn_unused_result" messages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
Andi Kleen35bb5b12008-02-22 15:15:03 +0100271config FRAME_WARN
Masahiro Yamadaa83e4ca2020-02-17 00:19:36 +0900272 int "Warn for stack frames larger than"
Andi Kleen35bb5b12008-02-22 15:15:03 +0100273 range 0 8192
Kees Cook0e07f662016-10-27 17:46:41 -0700274 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
Helge Deller432654d2017-09-11 21:41:43 +0200275 default 1280 if (!64BIT && PARISC)
276 default 1024 if (!64BIT && !PARISC)
Andi Kleen35bb5b12008-02-22 15:15:03 +0100277 default 2048 if 64BIT
278 help
279 Tell gcc to warn at build time for stack frames larger than this.
280 Setting this too low will cause a lot of warnings.
281 Setting it to 0 disables the warning.
Andi Kleen35bb5b12008-02-22 15:15:03 +0100282
Randy Dunlap99657c72009-09-18 12:49:22 -0700283config STRIP_ASM_SYMS
284 bool "Strip assembler-generated symbols during link"
285 default n
286 help
287 Strip internal assembler-generated symbols during a link (symbols
288 that look like '.Lxxx') so they don't pollute the output of
289 get_wchan() and suchlike.
290
Andi Kleen1873e872012-03-28 11:51:18 -0700291config READABLE_ASM
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800292 bool "Generate readable assembler code"
293 depends on DEBUG_KERNEL
Don Mullisbf4735a2006-12-10 02:18:37 -0800294 help
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800295 Disable some compiler optimizations that tend to generate human unreadable
296 assembler output. This may make the kernel slightly slower, but it helps
297 to keep kernel developers who have to stare a lot at assembler listings
298 sane.
Don Mullisbf4735a2006-12-10 02:18:37 -0800299
Masahiro Yamadae949f4c2019-06-04 19:13:59 +0900300config HEADERS_INSTALL
301 bool "Install uapi headers to usr/include"
Don Mullisbf4735a2006-12-10 02:18:37 -0800302 depends on !UML
303 help
Masahiro Yamadae949f4c2019-06-04 19:13:59 +0900304 This option will install uapi headers (headers exported to user-space)
305 into the usr/include directory for use during the kernel build.
306 This is unneeded for building the kernel itself, but needed for some
307 user-space program samples. It is also needed by some features such
308 as uapi header sanity checks.
309
Sam Ravnborg91341d42008-01-21 21:31:44 +0100310config DEBUG_SECTION_MISMATCH
311 bool "Enable full Section mismatch analysis"
Sam Ravnborg91341d42008-01-21 21:31:44 +0100312 help
313 The section mismatch analysis checks if there are illegal
314 references from one section to another section.
Michael Wittene809ab02011-04-17 04:08:48 +0000315 During linktime or runtime, some sections are dropped;
316 any use of code/data previously in these sections would
Sam Ravnborg91341d42008-01-21 21:31:44 +0100317 most likely result in an oops.
Michael Wittene809ab02011-04-17 04:08:48 +0000318 In the code, functions and variables are annotated with
Paul Gortmaker0db06282013-06-19 14:53:51 -0400319 __init,, etc. (see the full list in include/linux/init.h),
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100320 which results in the code/data being placed in specific sections.
Michael Wittene809ab02011-04-17 04:08:48 +0000321 The section mismatch analysis is always performed after a full
322 kernel build, and enabling this option causes the following
Masahiro Yamadab7dca6d2019-07-17 15:17:57 +0900323 additional step to occur:
Michael Wittene809ab02011-04-17 04:08:48 +0000324 - Add the option -fno-inline-functions-called-once to gcc commands.
325 When inlining a function annotated with __init in a non-init
326 function, we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100327 the analysis would not catch the illegal reference.
Michael Wittene809ab02011-04-17 04:08:48 +0000328 This option tells gcc to inline less (but it does result in
329 a larger kernel).
Sam Ravnborg91341d42008-01-21 21:31:44 +0100330
Nicolas Boichat47490ec2015-10-06 09:44:42 +1030331config SECTION_MISMATCH_WARN_ONLY
332 bool "Make section mismatch errors non-fatal"
333 default y
334 help
335 If you say N here, the build process will fail if there are any
336 section mismatch, instead of just throwing warnings.
337
338 If unsure, say Y.
339
Dave Hansen6dfc0662013-07-01 13:04:46 -0700340#
341# Select this config option from the architecture Kconfig, if it
342# is preferred to always offer frame pointers as a config
343# option on the architecture (regardless of KERNEL_DEBUG):
344#
345config ARCH_WANT_FRAME_POINTERS
346 bool
Dave Hansen6dfc0662013-07-01 13:04:46 -0700347
348config FRAME_POINTER
349 bool "Compile the kernel with frame pointers"
Arnd Bergmanna687a532018-03-07 23:30:54 +0100350 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
Dave Hansen6dfc0662013-07-01 13:04:46 -0700351 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
352 help
353 If you say Y here the resulting kernel image will be slightly
354 larger and slower, but it gives very useful debugging information
355 in case of kernel bugs. (precise oopses/stacktraces/warnings)
356
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -0600357config STACK_VALIDATION
358 bool "Compile-time stack metadata validation"
359 depends on HAVE_STACK_VALIDATION
360 default n
361 help
362 Add compile-time checks to validate stack metadata, including frame
363 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
364 that runtime stack traces are more reliable.
365
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500366 This is also a prerequisite for generation of ORC unwind data, which
Josh Poimboeuf11af8472017-10-13 15:02:00 -0500367 is needed for CONFIG_UNWINDER_ORC.
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500368
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -0600369 For more information, see
370 tools/objtool/Documentation/stack-validation.txt.
371
Peter Zijlstra6804c1a2020-03-18 13:33:54 +0100372config VMLINUX_VALIDATION
373 bool
374 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
375 default y
376
Dave Hansen6dfc0662013-07-01 13:04:46 -0700377config DEBUG_FORCE_WEAK_PER_CPU
378 bool "Force weak per-cpu definitions"
379 depends on DEBUG_KERNEL
380 help
381 s390 and alpha require percpu variables in modules to be
382 defined weak to work around addressing range issue which
383 puts the following two restrictions on percpu variable
384 definitions.
385
386 1. percpu symbols must be unique whether static or not
387 2. percpu variables can't be defined inside a function
388
389 To ensure that generic code follows the above rules, this
390 option forces all percpu variables to be defined as weak.
391
392endmenu # "Compiler options"
393
Changbin Du6210b642019-12-06 17:03:42 -0800394menu "Generic Kernel Debugging Instruments"
395
Dave Hansen6dfc0662013-07-01 13:04:46 -0700396config MAGIC_SYSRQ
397 bool "Magic SysRq key"
398 depends on !UML
399 help
400 If you say Y here, you will have some control over the system even
401 if the system crashes for example during kernel debugging (e.g., you
402 will be able to flush the buffer cache to disk, reboot the system
403 immediately or dump some status information). This is accomplished
404 by pressing various keys while holding SysRq (Alt+PrintScreen). It
405 also works on a serial console (on PC hardware at least), if you
406 send a BREAK and then within 5 seconds a command keypress. The
Hans Holmbergf8998c22017-03-16 09:37:32 +0100407 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
408 Don't say Y unless you really know what this hack does.
Dave Hansen6dfc0662013-07-01 13:04:46 -0700409
Ben Hutchings8eaede42013-10-07 01:05:46 +0100410config MAGIC_SYSRQ_DEFAULT_ENABLE
411 hex "Enable magic SysRq key functions by default"
412 depends on MAGIC_SYSRQ
413 default 0x1
414 help
415 Specifies which SysRq key functions are enabled by default.
416 This may be set to 1 or 0 to enable or disable them all, or
Hans Holmbergf8998c22017-03-16 09:37:32 +0100417 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
Ben Hutchings8eaede42013-10-07 01:05:46 +0100418
Felix Fietkau732dbf32016-12-22 08:31:34 +0100419config MAGIC_SYSRQ_SERIAL
420 bool "Enable magic SysRq key over serial"
421 depends on MAGIC_SYSRQ
422 default y
423 help
424 Many embedded boards have a disconnected TTL level serial which can
425 generate some garbage that can lead to spurious false sysrq detects.
426 This option allows you to decide whether you want to enable the
427 magic SysRq key.
428
Dmitry Safonov68af4312020-03-02 17:51:35 +0000429config MAGIC_SYSRQ_SERIAL_SEQUENCE
430 string "Char sequence that enables magic SysRq over serial"
431 depends on MAGIC_SYSRQ_SERIAL
432 default ""
433 help
434 Specifies a sequence of characters that can follow BREAK to enable
435 SysRq on a serial console.
436
Dmitry Safonovd3394b32020-03-06 15:31:56 +0000437 If unsure, leave an empty string and the option will not be enabled.
438
Changbin Duec29a5c2019-12-06 17:04:06 -0800439config DEBUG_FS
440 bool "Debug Filesystem"
441 help
442 debugfs is a virtual file system that kernel developers use to put
443 debugging files into. Enable this option to be able to read and
444 write to these files.
445
446 For detailed documentation on the debugfs API, see
447 Documentation/filesystems/.
448
449 If unsure, say N.
450
Changbin Du6210b642019-12-06 17:03:42 -0800451source "lib/Kconfig.kgdb"
452
453source "lib/Kconfig.ubsan"
454
455endmenu
456
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800457config DEBUG_KERNEL
458 bool "Kernel debugging"
459 help
460 Say Y here if you are developing drivers or trying to debug and
461 identify kernel problems.
462
Sinan Kayac66d7a22019-05-14 15:44:00 -0700463config DEBUG_MISC
464 bool "Miscellaneous debug code"
465 default DEBUG_KERNEL
466 depends on DEBUG_KERNEL
467 help
468 Say Y here if you need to enable miscellaneous debug code that should
469 be under a more specific debug option but isn't.
470
471
Dave Hansen0610c8a2013-07-01 13:04:43 -0700472menu "Memory Debugging"
David Woodhousea304e1b2007-02-12 00:52:00 -0800473
Masahiro Yamada8636a1f2018-12-11 20:01:04 +0900474source "mm/Kconfig.debug"
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800475
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700476config DEBUG_OBJECTS
477 bool "Debug object operations"
478 depends on DEBUG_KERNEL
479 help
480 If you say Y here, additional code will be inserted into the
481 kernel to track the life time of various objects and validate
482 the operations on those objects.
483
484config DEBUG_OBJECTS_SELFTEST
485 bool "Debug objects selftest"
486 depends on DEBUG_OBJECTS
487 help
488 This enables the selftest of the object debug code.
489
490config DEBUG_OBJECTS_FREE
491 bool "Debug objects in freed memory"
492 depends on DEBUG_OBJECTS
493 help
494 This enables checks whether a k/v free operation frees an area
495 which contains an object which has not been deactivated
496 properly. This can make kmalloc/kfree-intensive workloads
497 much slower.
498
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700499config DEBUG_OBJECTS_TIMERS
500 bool "Debug timer objects"
501 depends on DEBUG_OBJECTS
502 help
503 If you say Y here, additional code will be inserted into the
504 timer routines to track the life time of timer objects and
505 validate the timer operations.
506
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900507config DEBUG_OBJECTS_WORK
508 bool "Debug work objects"
509 depends on DEBUG_OBJECTS
510 help
511 If you say Y here, additional code will be inserted into the
512 work queue routines to track the life time of work objects and
513 validate the work operations.
514
Mathieu Desnoyers551d55a2010-04-17 08:48:42 -0400515config DEBUG_OBJECTS_RCU_HEAD
516 bool "Debug RCU callbacks objects"
Mathieu Desnoyersfc2ecf72011-02-23 09:42:14 -0800517 depends on DEBUG_OBJECTS
Mathieu Desnoyers551d55a2010-04-17 08:48:42 -0400518 help
519 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
520
Tejun Heoe2852ae2010-10-26 14:23:05 -0700521config DEBUG_OBJECTS_PERCPU_COUNTER
522 bool "Debug percpu counter objects"
523 depends on DEBUG_OBJECTS
524 help
525 If you say Y here, additional code will be inserted into the
526 percpu counter routines to track the life time of percpu counter
527 objects and validate the percpu counter operations.
528
Ingo Molnar3ae70202008-11-26 10:02:00 +0100529config DEBUG_OBJECTS_ENABLE_DEFAULT
530 int "debug_objects bootup default value (0-1)"
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800531 range 0 1
532 default "1"
533 depends on DEBUG_OBJECTS
534 help
535 Debug objects boot parameter default value
Ingo Molnar3ae70202008-11-26 10:02:00 +0100536
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800538 bool "Debug slab memory allocations"
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -0800539 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 help
541 Say Y here to have the kernel do limited verification on memory
542 allocation as well as poisoning memory on free to catch use of freed
543 memory. This can make kmalloc/kfree-intensive workloads much slower.
544
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700545config SLUB_DEBUG_ON
546 bool "SLUB debugging on by default"
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -0800547 depends on SLUB && SLUB_DEBUG
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700548 default n
549 help
550 Boot with debugging on by default. SLUB boots by default with
551 the runtime debug capabilities switched off. Enabling this is
552 equivalent to specifying the "slub_debug" parameter on boot.
553 There is no support for more fine grained debug control like
554 possible with slub_debug=xxx. SLUB debugging may be switched
555 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
556 "slub_debug=-".
557
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800558config SLUB_STATS
559 default n
560 bool "Enable SLUB performance statistics"
Christoph Lameterab4d5ed2010-10-05 13:57:26 -0500561 depends on SLUB && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800562 help
563 SLUB statistics are useful to debug SLUBs allocation behavior in
564 order find ways to optimize the allocator. This should never be
565 enabled for production use since keeping statistics slows down
566 the allocator by a few percentage points. The slabinfo command
567 supports the determination of the most active slabs to figure
568 out which slabs are relevant to a particular load.
569 Try running: slabinfo -DA
570
Catalin Marinasb69ec422012-10-08 16:28:11 -0700571config HAVE_DEBUG_KMEMLEAK
572 bool
573
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100574config DEBUG_KMEMLEAK
575 bool "Kernel memory leak detector"
Kees Cook525c1f92013-01-16 18:54:16 -0800576 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
Catalin Marinas79e0d9b2011-04-27 17:06:19 +0100577 select DEBUG_FS
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100578 select STACKTRACE if STACKTRACE_SUPPORT
579 select KALLSYMS
Randy Dunlapb60e26a2009-11-06 15:33:45 -0800580 select CRC32
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100581 help
582 Say Y here if you want to enable the memory leak
583 detector. The memory allocation/freeing is traced in a way
584 similar to the Boehm's conservative garbage collector, the
585 difference being that the orphan objects are not freed but
586 only shown in /sys/kernel/debug/kmemleak. Enabling this
587 feature will introduce an overhead to memory
Andreas Platschek700199b02016-12-14 15:05:40 -0800588 allocations. See Documentation/dev-tools/kmemleak.rst for more
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100589 details.
590
Catalin Marinasbf96d1e2009-06-23 14:40:27 +0100591 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
592 of finding leaks due to the slab objects poisoning.
593
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100594 In order to access the kmemleak file, debugfs needs to be
595 mounted (usually at /sys/kernel/debug).
596
Catalin Marinasc5665862019-09-23 15:34:05 -0700597config DEBUG_KMEMLEAK_MEM_POOL_SIZE
598 int "Kmemleak memory pool size"
Catalin Marinasa9d90582009-06-25 10:16:11 +0100599 depends on DEBUG_KMEMLEAK
Qian Caic59180a2019-09-23 15:34:10 -0700600 range 200 1000000
Nicolas Boichatb751c522019-09-23 15:33:55 -0700601 default 16000
Catalin Marinasa9d90582009-06-25 10:16:11 +0100602 help
603 Kmemleak must track all the memory allocations to avoid
604 reporting false positives. Since memory may be allocated or
Catalin Marinasc5665862019-09-23 15:34:05 -0700605 freed before kmemleak is fully initialised, use a static pool
606 of metadata objects to track such callbacks. After kmemleak is
607 fully initialised, this memory pool acts as an emergency one
608 if slab allocations fail.
Catalin Marinasa9d90582009-06-25 10:16:11 +0100609
Catalin Marinas0822ee42009-06-11 13:24:14 +0100610config DEBUG_KMEMLEAK_TEST
611 tristate "Simple test for the kernel memory leak detector"
Daniel Baluta97182692011-04-04 15:06:44 -0700612 depends on DEBUG_KMEMLEAK && m
Catalin Marinas0822ee42009-06-11 13:24:14 +0100613 help
Daniel Baluta97182692011-04-04 15:06:44 -0700614 This option enables a module that explicitly leaks memory.
Catalin Marinas0822ee42009-06-11 13:24:14 +0100615
616 If unsure, say N.
617
Jason Baronab0155a2010-07-19 11:54:17 +0100618config DEBUG_KMEMLEAK_DEFAULT_OFF
619 bool "Default kmemleak to off"
620 depends on DEBUG_KMEMLEAK
621 help
622 Say Y here to disable kmemleak by default. It can then be enabled
623 on the command line via kmemleak=on.
624
Sri Krishna chowdaryd53ce042018-12-28 00:38:54 -0800625config DEBUG_KMEMLEAK_AUTO_SCAN
626 bool "Enable kmemleak auto scan thread on boot up"
627 default y
628 depends on DEBUG_KMEMLEAK
629 help
630 Depending on the cpu, kmemleak scan may be cpu intensive and can
631 stall user tasks at times. This option enables/disables automatic
632 kmemleak scan at boot up.
633
634 Say N here to disable kmemleak auto scan thread to stop automatic
635 scanning. Disabling this option disables automatic reporting of
636 memory leaks.
637
638 If unsure, say Y.
639
Dave Hansen0610c8a2013-07-01 13:04:43 -0700640config DEBUG_STACK_USAGE
641 bool "Stack utilization instrumentation"
Helge Deller6c31da32016-03-19 17:54:10 +0100642 depends on DEBUG_KERNEL && !IA64
Dave Hansen0610c8a2013-07-01 13:04:43 -0700643 help
644 Enables the display of the minimum amount of free stack which each
645 task has ever had available in the sysrq-T and sysrq-P debug output.
646
647 This option will slow down process creation somewhat.
648
Changbin Dudc9b9632019-12-06 17:03:57 -0800649config SCHED_STACK_END_CHECK
650 bool "Detect stack corruption on calls to schedule()"
651 depends on DEBUG_KERNEL
652 default n
653 help
654 This option checks for a stack overrun on calls to schedule().
655 If the stack end location is found to be over written always panic as
656 the content of the corrupted region can no longer be trusted.
657 This is to ensure no erroneous behaviour occurs which could result in
658 data corruption or a sporadic crash at a later stage once the region
659 is examined. The runtime overhead introduced is minimal.
660
Dave Hansen0610c8a2013-07-01 13:04:43 -0700661config DEBUG_VM
662 bool "Debug VM"
663 depends on DEBUG_KERNEL
664 help
665 Enable this to turn on extended checks in the virtual-memory system
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800666 that may impact performance.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700667
668 If unsure, say N.
669
Davidlohr Bueso4f115142014-06-04 16:06:46 -0700670config DEBUG_VM_VMACACHE
671 bool "Debug VMA caching"
672 depends on DEBUG_VM
673 help
674 Enable this to turn on VMA caching debug information. Doing so
675 can cause significant overhead, so only enable it in non-production
676 environments.
677
678 If unsure, say N.
679
Dave Hansen0610c8a2013-07-01 13:04:43 -0700680config DEBUG_VM_RB
681 bool "Debug VM red-black trees"
682 depends on DEBUG_VM
683 help
Davidlohr Buesoa663dad2014-04-18 15:07:22 -0700684 Enable VM red-black tree debugging information and extra validations.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700685
686 If unsure, say N.
687
Kirill A. Shutemov95ad9752016-01-15 16:51:21 -0800688config DEBUG_VM_PGFLAGS
689 bool "Debug page-flags operations"
690 depends on DEBUG_VM
691 help
692 Enables extra validation on page flags operations.
693
694 If unsure, say N.
695
Laura Abbottfa5b6ec2017-01-10 13:35:40 -0800696config ARCH_HAS_DEBUG_VIRTUAL
697 bool
698
Dave Hansen0610c8a2013-07-01 13:04:43 -0700699config DEBUG_VIRTUAL
700 bool "Debug VM translations"
Laura Abbottfa5b6ec2017-01-10 13:35:40 -0800701 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
Dave Hansen0610c8a2013-07-01 13:04:43 -0700702 help
703 Enable some costly sanity checks in virtual to page code. This can
704 catch mistakes with virt_to_page() and friends.
705
706 If unsure, say N.
707
708config DEBUG_NOMMU_REGIONS
709 bool "Debug the global anon/private NOMMU mapping region tree"
710 depends on DEBUG_KERNEL && !MMU
711 help
712 This option causes the global tree of anonymous and private mapping
713 regions to be regularly checked for invalid topology.
714
715config DEBUG_MEMORY_INIT
716 bool "Debug memory initialisation" if EXPERT
717 default !EXPERT
718 help
719 Enable this for additional checks during memory initialisation.
720 The sanity checks verify aspects of the VM such as the memory model
721 and other information provided by the architecture. Verbose
722 information will be printed at KERN_DEBUG loglevel depending
723 on the mminit_loglevel= command-line option.
724
725 If unsure, say Y
726
727config MEMORY_NOTIFIER_ERROR_INJECT
728 tristate "Memory hotplug notifier error injection module"
729 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
730 help
731 This option provides the ability to inject artificial errors to
732 memory hotplug notifier chain callbacks. It is controlled through
733 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
734
735 If the notifier call chain should be failed with some events
736 notified, write the error code to "actions/<notifier event>/error".
737
738 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
739
740 # cd /sys/kernel/debug/notifier-error-inject/memory
741 # echo -12 > actions/MEM_GOING_OFFLINE/error
742 # echo offline > /sys/devices/system/memory/memoryXXX/state
743 bash: echo: write error: Cannot allocate memory
744
745 To compile this code as a module, choose M here: the module will
746 be called memory-notifier-error-inject.
747
748 If unsure, say N.
749
750config DEBUG_PER_CPU_MAPS
751 bool "Debug access to per_cpu maps"
752 depends on DEBUG_KERNEL
753 depends on SMP
754 help
755 Say Y to verify that the per_cpu map being accessed has
756 been set up. This adds a fair amount of code to kernel memory
757 and decreases performance.
758
759 Say N if unsure.
760
761config DEBUG_HIGHMEM
762 bool "Highmem debugging"
763 depends on DEBUG_KERNEL && HIGHMEM
764 help
Geert Uytterhoevenb1357c92014-04-14 18:55:50 +0200765 This option enables additional error checking for high memory
766 systems. Disable for production systems.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700767
768config HAVE_DEBUG_STACKOVERFLOW
769 bool
770
771config DEBUG_STACKOVERFLOW
772 bool "Check for stack overflows"
773 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
774 ---help---
775 Say Y here if you want to check for overflows of kernel, IRQ
Borislav Petkovedb0ec02015-01-25 19:50:34 +0100776 and exception stacks (if your architecture uses them). This
Dave Hansen0610c8a2013-07-01 13:04:43 -0700777 option will show detailed messages if free stack space drops
778 below a certain limit.
779
780 These kinds of bugs usually occur when call-chains in the
781 kernel get too deep, especially when interrupts are
782 involved.
783
784 Use this in cases where you see apparently random memory
785 corruption, especially if it appears in 'struct thread_info'
786
787 If in doubt, say "N".
788
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -0800789source "lib/Kconfig.kasan"
790
Dave Hansen0610c8a2013-07-01 13:04:43 -0700791endmenu # "Memory Debugging"
792
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793config DEBUG_SHIRQ
794 bool "Debug shared IRQ handlers"
Martin Schwidefsky0244ad02013-08-30 09:39:53 +0200795 depends on DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 help
797 Enable this to generate a spurious interrupt as soon as a shared
798 interrupt handler is registered, and just before one is deregistered.
799 Drivers ought to be able to handle interrupts coming in at those
800 points; some don't and need to be caught.
801
Changbin Duf43a2892019-12-06 17:03:54 -0800802menu "Debug Oops, Lockups and Hangs"
803
804config PANIC_ON_OOPS
805 bool "Panic on Oops"
806 help
807 Say Y here to enable the kernel to panic when it oopses. This
808 has the same effect as setting oops=panic on the kernel command
809 line.
810
811 This feature is useful to ensure that the kernel does not do
812 anything erroneous after an oops which could result in data
813 corruption or other issues.
814
815 Say N if unsure.
816
817config PANIC_ON_OOPS_VALUE
818 int
819 range 0 1
820 default 0 if !PANIC_ON_OOPS
821 default 1 if PANIC_ON_OOPS
822
823config PANIC_TIMEOUT
824 int "panic timeout"
825 default 0
826 help
827 Set the timeout value (in seconds) until a reboot occurs when the
828 the kernel panics. If n = 0, then we wait forever. A timeout
829 value n > 0 will wait n seconds before rebooting, while a timeout
830 value n < 0 will reboot immediately.
Dave Hansen92aef8fb2013-07-01 13:04:50 -0700831
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832config LOCKUP_DETECTOR
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700833 bool
834
835config SOFTLOCKUP_DETECTOR
836 bool "Detect Soft Lockups"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 depends on DEBUG_KERNEL && !S390
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700838 select LOCKUP_DETECTOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 help
840 Say Y here to enable the kernel to act as a watchdog to detect
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700841 soft lockups.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 Softlockups are bugs that cause the kernel to loop in kernel
844 mode for more than 20 seconds, without giving other tasks a
845 chance to run. The current stack trace is displayed upon
846 detection and the system will stay locked up.
847
Randy Dunlap5f00ae02018-04-10 16:32:51 -0700848config BOOTPARAM_SOFTLOCKUP_PANIC
849 bool "Panic (Reboot) On Soft Lockups"
850 depends on SOFTLOCKUP_DETECTOR
851 help
852 Say Y here to enable the kernel to panic on "soft lockups",
853 which are bugs that cause the kernel to loop in kernel
854 mode for more than 20 seconds (configurable using the watchdog_thresh
855 sysctl), without giving other tasks a chance to run.
856
857 The panic can be used in combination with panic_timeout,
858 to cause the system to reboot automatically after a
859 lockup has been detected. This feature is useful for
860 high-availability systems that have uptime guarantees and
861 where a lockup must be resolved ASAP.
862
863 Say N if unsure.
864
865config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
866 int
867 depends on SOFTLOCKUP_DETECTOR
868 range 0 1
869 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
870 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
871
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700872config HARDLOCKUP_DETECTOR_PERF
873 bool
874 select SOFTLOCKUP_DETECTOR
875
876#
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200877# Enables a timestamp based low pass filter to compensate for perf based
878# hard lockup detection which runs too fast due to turbo modes.
879#
880config HARDLOCKUP_CHECK_TIMESTAMP
881 bool
882
883#
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700884# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
885# lockup detector rather than the perf based detector.
886#
887config HARDLOCKUP_DETECTOR
888 bool "Detect Hard Lockups"
889 depends on DEBUG_KERNEL && !S390
890 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
891 select LOCKUP_DETECTOR
892 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
893 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
894 help
895 Say Y here to enable the kernel to act as a watchdog to detect
896 hard lockups.
897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 Hardlockups are bugs that cause the CPU to loop in kernel mode
899 for more than 10 seconds, without letting other interrupts have a
900 chance to run. The current stack trace is displayed upon detection
901 and the system will stay locked up.
902
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903config BOOTPARAM_HARDLOCKUP_PANIC
904 bool "Panic (Reboot) On Hard Lockups"
905 depends on HARDLOCKUP_DETECTOR
906 help
907 Say Y here to enable the kernel to panic on "hard lockups",
908 which are bugs that cause the kernel to loop in kernel
909 mode with interrupts disabled for more than 10 seconds (configurable
910 using the watchdog_thresh sysctl).
911
912 Say N if unsure.
913
914config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
915 int
916 depends on HARDLOCKUP_DETECTOR
917 range 0 1
918 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
919 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
920
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921config DETECT_HUNG_TASK
922 bool "Detect Hung Tasks"
923 depends on DEBUG_KERNEL
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700924 default SOFTLOCKUP_DETECTOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 help
926 Say Y here to enable the kernel to detect "hung tasks",
927 which are bugs that cause the task to be stuck in
Vivien Didelot96b03ab2016-09-22 16:55:13 -0400928 uninterruptible "D" state indefinitely.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929
930 When a hung task is detected, the kernel will print the
931 current stack trace (which you should report), but the
932 task will stay in uninterruptible state. If lockdep is
933 enabled then all held locks will also be reported. This
934 feature has negligible overhead.
Al Viro871751e2006-03-25 03:06:39 -0800935
936config DEFAULT_HUNG_TASK_TIMEOUT
937 int "Default timeout for hung task detection (in seconds)"
938 depends on DETECT_HUNG_TASK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 default 120
940 help
Ingo Molnar8637c092006-07-03 00:24:38 -0700941 This option controls the default timeout (in seconds) used
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942 to determine when a task has become non-responsive and should
943 be considered hung.
944
945 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
946 sysctl or by writing a value to
947 /proc/sys/kernel/hung_task_timeout_secs.
948
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700949 A timeout of 0 disables the check. The default is two minutes.
950 Keeping the default should be fine in most cases.
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700951
952config BOOTPARAM_HUNG_TASK_PANIC
953 bool "Panic (Reboot) On Hung Tasks"
954 depends on DETECT_HUNG_TASK
955 help
956 Say Y here to enable the kernel to panic on "hung tasks",
957 which are bugs that cause the kernel to leave a task stuck
958 in uninterruptible "D" state.
959
960 The panic can be used in combination with panic_timeout,
Thomas Gleixner61a87122006-06-27 02:54:56 -0700961 to cause the system to reboot automatically after a
962 hung task has been detected. This feature is useful for
Roman Zippela1583d32006-06-27 02:55:00 -0700963 high-availability systems that have uptime guarantees and
Thomas Gleixner61a87122006-06-27 02:54:56 -0700964 where a hung tasks must be resolved ASAP.
965
966 Say N if unsure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100968config BOOTPARAM_HUNG_TASK_PANIC_VALUE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 int
970 depends on DETECT_HUNG_TASK
971 range 0 1
972 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
973 default 1 if BOOTPARAM_HUNG_TASK_PANIC
974
Tejun Heo82607adc2015-12-08 11:28:04 -0500975config WQ_WATCHDOG
976 bool "Detect Workqueue Stalls"
977 depends on DEBUG_KERNEL
978 help
979 Say Y here to enable stall detection on workqueues. If a
980 worker pool doesn't make forward progress on a pending work
981 item for over a given amount of time, 30s by default, a
982 warning message is printed along with dump of workqueue
983 state. This can be configured through kernel parameter
984 "workqueue.watchdog_thresh" and its sysfs counterpart.
985
Konstantin Khlebnikov30428ef2020-04-06 20:09:47 -0700986config TEST_LOCKUP
987 tristate "Test module to generate lockups"
988 help
989 This builds the "test_lockup" module that helps to make sure
990 that watchdogs and lockup detectors are working properly.
991
992 Depending on module parameters it could emulate soft or hard
993 lockup, "hung task", or locking arbitrary lock for a long time.
994 Also it could generate series of lockups with cooling-down periods.
995
996 If unsure, say N.
997
Dave Hansen92aef8fb2013-07-01 13:04:50 -0700998endmenu # "Debug lockups and hangs"
999
Changbin Duebebdd02019-12-06 17:04:00 -08001000menu "Scheduler Debugging"
Jason Baron5800dc32013-11-25 23:23:04 +00001001
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002config SCHED_DEBUG
1003 bool "Collect scheduler debugging info"
1004 depends on DEBUG_KERNEL && PROC_FS
1005 default y
1006 help
1007 If you say Y here, the /proc/sched_debug file will be provided
1008 that can help debug the scheduler. The runtime overhead of this
1009 option is minimal.
1010
Naveen N. Raof6db8342015-06-25 23:53:37 +05301011config SCHED_INFO
1012 bool
1013 default n
1014
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015config SCHEDSTATS
1016 bool "Collect scheduler statistics"
1017 depends on DEBUG_KERNEL && PROC_FS
Naveen N. Raof6db8342015-06-25 23:53:37 +05301018 select SCHED_INFO
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 help
1020 If you say Y here, additional code will be inserted into the
1021 scheduler and related routines to collect statistics about
1022 scheduler behavior and provide them in /proc/schedstat. These
1023 stats may be useful for both tuning and debugging the scheduler
1024 If you aren't debugging the scheduler or trying to tune a specific
1025 application, you can say N to avoid the very slight overhead
1026 this adds.
1027
Changbin Duebebdd02019-12-06 17:04:00 -08001028endmenu
Aaron Tomlin0d9e2632014-09-12 14:16:19 +01001029
John Stultz3c17ad12015-03-11 21:16:32 -07001030config DEBUG_TIMEKEEPING
1031 bool "Enable extra timekeeping sanity checking"
1032 help
1033 This option will enable additional timekeeping sanity checks
1034 which may be helpful when diagnosing issues where timekeeping
1035 problems are suspected.
1036
1037 This may include checks in the timekeeping hotpaths, so this
1038 option may have a (very small) performance impact to some
1039 workloads.
1040
1041 If unsure, say N.
1042
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043config DEBUG_PREEMPT
1044 bool "Debug preemptible kernel"
Sebastian Andrzej Siewior9f472862019-10-15 21:18:19 +02001045 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 default y
1047 help
1048 If you say Y here then the kernel will use a debug variant of the
1049 commonly used smp_processor_id() function and will print warnings
1050 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1051 will detect preemption count underflows.
1052
Dave Hansen9eade162013-07-01 13:04:47 -07001053menu "Lock Debugging (spinlocks, mutexes, etc...)"
1054
Waiman Longf07cbeb2018-03-30 17:27:59 -04001055config LOCK_DEBUGGING_SUPPORT
1056 bool
1057 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1058 default y
1059
Waiman Long19193bc2018-03-30 17:28:00 -04001060config PROVE_LOCKING
1061 bool "Lock debugging: prove locking correctness"
1062 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1063 select LOCKDEP
1064 select DEBUG_SPINLOCK
1065 select DEBUG_MUTEXES
1066 select DEBUG_RT_MUTEXES if RT_MUTEXES
Waiman Longc71fd892019-05-20 16:59:00 -04001067 select DEBUG_RWSEMS
Waiman Long19193bc2018-03-30 17:28:00 -04001068 select DEBUG_WW_MUTEX_SLOWPATH
1069 select DEBUG_LOCK_ALLOC
1070 select TRACE_IRQFLAGS
1071 default n
1072 help
1073 This feature enables the kernel to prove that all locking
1074 that occurs in the kernel runtime is mathematically
1075 correct: that under no circumstance could an arbitrary (and
1076 not yet triggered) combination of observed locking
1077 sequences (on an arbitrary number of CPUs, running an
1078 arbitrary number of tasks and interrupt contexts) cause a
1079 deadlock.
1080
1081 In short, this feature enables the kernel to report locking
1082 related deadlocks before they actually occur.
1083
1084 The proof does not depend on how hard and complex a
1085 deadlock scenario would be to trigger: how many
1086 participant CPUs, tasks and irq-contexts would be needed
1087 for it to trigger. The proof also does not depend on
1088 timing: if a race and a resulting deadlock is possible
1089 theoretically (no matter how unlikely the race scenario
1090 is), it will be proven so and will immediately be
1091 reported by the kernel (once the event is observed that
1092 makes the deadlock theoretically possible).
1093
1094 If a deadlock is impossible (i.e. the locking rules, as
1095 observed by the kernel, are mathematically correct), the
1096 kernel reports nothing.
1097
1098 NOTE: this feature can also be enabled for rwlocks, mutexes
1099 and rwsems - in which case all dependencies between these
1100 different locking variants are observed and mapped too, and
1101 the proof of observed correctness is also maintained for an
1102 arbitrary combination of these separate locking variants.
1103
Mauro Carvalho Chehab387b1462019-04-10 08:32:41 -03001104 For more details, see Documentation/locking/lockdep-design.rst.
Waiman Long19193bc2018-03-30 17:28:00 -04001105
Peter Zijlstrade8f5e42020-03-21 12:26:01 +01001106config PROVE_RAW_LOCK_NESTING
1107 bool "Enable raw_spinlock - spinlock nesting checks"
1108 depends on PROVE_LOCKING
1109 default n
1110 help
1111 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1112 that the lock nesting rules for PREEMPT_RT enabled kernels are
1113 not violated.
1114
1115 NOTE: There are known nesting problems. So if you enable this
1116 option expect lockdep splats until these problems have been fully
1117 addressed which is work in progress. This config switch allows to
1118 identify and analyze these problems. It will be removed and the
1119 check permanentely enabled once the main issues have been fixed.
1120
1121 If unsure, select N.
1122
Waiman Long19193bc2018-03-30 17:28:00 -04001123config LOCK_STAT
1124 bool "Lock usage statistics"
1125 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1126 select LOCKDEP
1127 select DEBUG_SPINLOCK
1128 select DEBUG_MUTEXES
1129 select DEBUG_RT_MUTEXES if RT_MUTEXES
1130 select DEBUG_LOCK_ALLOC
1131 default n
1132 help
1133 This feature enables tracking lock contention points
1134
Mauro Carvalho Chehab387b1462019-04-10 08:32:41 -03001135 For more details, see Documentation/locking/lockstat.rst
Waiman Long19193bc2018-03-30 17:28:00 -04001136
1137 This also enables lock events required by "perf lock",
1138 subcommand of perf.
1139 If you want to use "perf lock", you also need to turn on
1140 CONFIG_EVENT_TRACING.
1141
1142 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1143 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1144
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145config DEBUG_RT_MUTEXES
1146 bool "RT Mutex debugging, deadlock detection"
1147 depends on DEBUG_KERNEL && RT_MUTEXES
1148 help
1149 This allows rt mutex semantics violations and rt mutex related
1150 deadlocks (lockups) to be detected and reported automatically.
1151
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001153 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 depends on DEBUG_KERNEL
Raghavendra K Te335e3e2012-03-22 15:25:08 +05301155 select UNINLINE_SPIN_UNLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 help
1157 Say Y here and build SMP to catch missing spinlock initialization
1158 and certain other kinds of spinlock errors commonly made. This is
1159 best used in conjunction with the NMI watchdog so that spinlock
1160 deadlocks are also debuggable.
1161
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001162config DEBUG_MUTEXES
1163 bool "Mutex debugging: basic checks"
1164 depends on DEBUG_KERNEL
1165 help
1166 This feature allows mutex semantics violations to be detected and
1167 reported.
1168
Daniel Vetter23010022013-06-20 13:31:17 +02001169config DEBUG_WW_MUTEX_SLOWPATH
1170 bool "Wait/wound mutex debugging: Slowpath testing"
Waiman Longf07cbeb2018-03-30 17:27:59 -04001171 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Daniel Vetter23010022013-06-20 13:31:17 +02001172 select DEBUG_LOCK_ALLOC
1173 select DEBUG_SPINLOCK
1174 select DEBUG_MUTEXES
1175 help
1176 This feature enables slowpath testing for w/w mutex users by
1177 injecting additional -EDEADLK wound/backoff cases. Together with
1178 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1179 will test all possible w/w mutex interface abuse with the
1180 exception of simply not acquiring all the required locks.
Rob Clark4d692372014-08-27 11:19:26 -04001181 Note that this feature can introduce significant overhead, so
1182 it really should not be enabled in a production or distro kernel,
1183 even a debug kernel. If you are a driver writer, enable it. If
1184 you are a distro, do not.
Daniel Vetter23010022013-06-20 13:31:17 +02001185
Waiman Long5149cba2018-03-30 17:27:58 -04001186config DEBUG_RWSEMS
1187 bool "RW Semaphore debugging: basic checks"
Waiman Longc71fd892019-05-20 16:59:00 -04001188 depends on DEBUG_KERNEL
Waiman Long5149cba2018-03-30 17:27:58 -04001189 help
Waiman Longc71fd892019-05-20 16:59:00 -04001190 This debugging feature allows mismatched rw semaphore locks
1191 and unlocks to be detected and reported.
Waiman Long5149cba2018-03-30 17:27:58 -04001192
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001193config DEBUG_LOCK_ALLOC
1194 bool "Lock debugging: detect incorrect freeing of live locks"
Waiman Longf07cbeb2018-03-30 17:27:59 -04001195 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001196 select DEBUG_SPINLOCK
1197 select DEBUG_MUTEXES
Peter Zijlstraf5694782016-09-19 12:15:37 +02001198 select DEBUG_RT_MUTEXES if RT_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001199 select LOCKDEP
1200 help
1201 This feature will check whether any held lock (spinlock, rwlock,
1202 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1203 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1204 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1205 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1206 held during task exit.
1207
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001208config LOCKDEP
1209 bool
Waiman Longf07cbeb2018-03-30 17:27:59 -04001210 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001211 select STACKTRACE
Stefan Agnerf9b58e82018-09-30 23:02:33 +01001212 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001213 select KALLSYMS
1214 select KALLSYMS_ALL
1215
Daniel Jordan395102d2017-04-10 11:50:52 -04001216config LOCKDEP_SMALL
1217 bool
1218
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001219config DEBUG_LOCKDEP
1220 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -07001221 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001222 help
1223 If you say Y here, the lock dependency engine will do
1224 additional runtime checks to debug itself, at the price
1225 of more runtime overhead.
1226
Frederic Weisbeckerd902db12011-06-08 19:31:56 +02001227config DEBUG_ATOMIC_SLEEP
1228 bool "Sleep inside atomic section checking"
Frederic Weisbeckere8f7c702011-06-08 01:51:02 +02001229 select PREEMPT_COUNT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 depends on DEBUG_KERNEL
Christoph Hellwig87a4c372018-07-31 13:39:32 +02001231 depends on !ARCH_NO_PREEMPT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 help
1233 If you say Y here, various routines which may sleep will become very
Frederic Weisbeckerd902db12011-06-08 19:31:56 +02001234 noisy if they are called inside atomic sections: when a spinlock is
1235 held, inside an rcu read side critical section, inside preempt disabled
1236 sections, inside an interrupt, etc...
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237
Ingo Molnarcae2ed92006-07-03 00:24:48 -07001238config DEBUG_LOCKING_API_SELFTESTS
1239 bool "Locking API boot-time self-tests"
1240 depends on DEBUG_KERNEL
1241 help
1242 Say Y here if you want the kernel to run a short self-test during
1243 bootup. The self-test checks whether common types of locking bugs
1244 are detected by debugging mechanisms or not. (if you disable
1245 lock debugging then those bugs wont be detected of course.)
1246 The following locking APIs are covered: spinlocks, rwlocks,
1247 mutexes and rwsems.
1248
Paul E. McKenney0af3fe12014-02-04 15:51:41 -08001249config LOCK_TORTURE_TEST
1250 tristate "torture tests for locking"
1251 depends on DEBUG_KERNEL
1252 select TORTURE_TEST
Paul E. McKenney0af3fe12014-02-04 15:51:41 -08001253 help
1254 This option provides a kernel module that runs torture tests
1255 on kernel locking primitives. The kernel module may be built
1256 after the fact on the running kernel to be tested, if desired.
1257
1258 Say Y here if you want kernel locking-primitive torture tests
1259 to be built into the kernel.
1260 Say M if you want these torture tests to build as a module.
1261 Say N if you are unsure.
1262
Chris Wilsonf2a5fec2016-12-01 11:47:06 +00001263config WW_MUTEX_SELFTEST
1264 tristate "Wait/wound mutex selftests"
1265 help
1266 This option provides a kernel module that runs tests on the
1267 on the struct ww_mutex locking API.
1268
1269 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1270 with this test harness.
1271
1272 Say M if you want these self tests to build as a module.
1273 Say N if you are unsure.
1274
Dave Hansen9eade162013-07-01 13:04:47 -07001275endmenu # lock debugging
1276
1277config TRACE_IRQFLAGS
1278 bool
1279 help
1280 Enables hooks to interrupt enabling and disabling for
1281 either tracing or lock debugging.
1282
Ingo Molnar8637c092006-07-03 00:24:38 -07001283config STACKTRACE
Dave Jones0c38e1f2014-08-29 15:18:35 -07001284 bool "Stack backtrace support"
Ingo Molnar8637c092006-07-03 00:24:38 -07001285 depends on STACKTRACE_SUPPORT
Dave Jones0c38e1f2014-08-29 15:18:35 -07001286 help
1287 This option causes the kernel to create a /proc/pid/stack for
1288 every process, showing its current stack trace.
1289 It is also used by various kernel debugging features that require
1290 stack trace generation.
Ingo Molnar8637c092006-07-03 00:24:38 -07001291
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001292config WARN_ALL_UNSEEDED_RANDOM
1293 bool "Warn for all uses of unseeded randomness"
1294 default n
Jason A. Donenfeldd06bfd12017-06-07 23:06:55 -04001295 help
1296 Some parts of the kernel contain bugs relating to their use of
1297 cryptographically secure random numbers before it's actually possible
1298 to generate those numbers securely. This setting ensures that these
1299 flaws don't go unnoticed, by enabling a message, should this ever
1300 occur. This will allow people with obscure setups to know when things
1301 are going wrong, so that they might contact developers about fixing
1302 it.
1303
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001304 Unfortunately, on some models of some architectures getting
1305 a fully seeded CRNG is extremely difficult, and so this can
1306 result in dmesg getting spammed for a surprisingly long
1307 time. This is really bad from a security perspective, and
1308 so architecture maintainers really need to do what they can
1309 to get the CRNG seeded sooner after the system is booted.
Thibaut Sautereau4c5d1142018-09-04 15:46:23 -07001310 However, since users cannot do anything actionable to
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001311 address this, by default the kernel will issue only a single
1312 warning for the first use of unseeded randomness.
1313
1314 Say Y here if you want to receive warnings for all uses of
1315 unseeded randomness. This will be of use primarily for
Thibaut Sautereau4c5d1142018-09-04 15:46:23 -07001316 those developers interested in improving the security of
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001317 Linux kernels running on their architecture (or
1318 subarchitecture).
Jason A. Donenfeldd06bfd12017-06-07 23:06:55 -04001319
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320config DEBUG_KOBJECT
1321 bool "kobject debugging"
1322 depends on DEBUG_KERNEL
1323 help
1324 If you say Y here, some extra kobject debugging messages will be sent
Mike Rapoportaca52c32018-10-30 15:07:44 -07001325 to the syslog.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326
Russell Kingc817a672013-06-27 15:06:14 +01001327config DEBUG_KOBJECT_RELEASE
1328 bool "kobject release debugging"
Linus Torvalds2a999aa2013-10-29 08:33:36 -07001329 depends on DEBUG_OBJECTS_TIMERS
Russell Kingc817a672013-06-27 15:06:14 +01001330 help
1331 kobjects are reference counted objects. This means that their
1332 last reference count put is not predictable, and the kobject can
1333 live on past the point at which a driver decides to drop it's
1334 initial reference to the kobject gained on allocation. An
1335 example of this would be a struct device which has just been
1336 unregistered.
1337
1338 However, some buggy drivers assume that after such an operation,
1339 the memory backing the kobject can be immediately freed. This
1340 goes completely against the principles of a refcounted object.
1341
1342 If you say Y here, the kernel will delay the release of kobjects
1343 on the last reference count to improve the visibility of this
1344 kind of kobject release bug.
1345
Catalin Marinas9b2a60c2012-10-08 16:28:13 -07001346config HAVE_DEBUG_BUGVERBOSE
1347 bool
1348
Changbin Du3be5cbc2019-12-06 17:03:48 -08001349menu "Debug kernel data structures"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350
Dave Jones199a9af2006-09-29 01:59:00 -07001351config DEBUG_LIST
1352 bool "Debug linked list manipulation"
Arnd Bergmann4520bcb2016-08-26 17:42:00 +02001353 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
Dave Jones199a9af2006-09-29 01:59:00 -07001354 help
1355 Enable this to turn on extended checks in the linked-list
1356 walking routines.
1357
1358 If unsure, say N.
1359
Davidlohr Bueso8e18fae2019-05-14 15:42:46 -07001360config DEBUG_PLIST
Dan Streetmanb8cfff62014-06-04 16:11:54 -07001361 bool "Debug priority linked list manipulation"
1362 depends on DEBUG_KERNEL
1363 help
1364 Enable this to turn on extended checks in the priority-ordered
1365 linked-list (plist) walking routines. This checks the entire
1366 list multiple times during each manipulation.
1367
1368 If unsure, say N.
1369
Jens Axboed6ec0842007-10-22 20:01:06 +02001370config DEBUG_SG
1371 bool "Debug SG table operations"
1372 depends on DEBUG_KERNEL
1373 help
1374 Enable this to turn on checks on scatter-gather tables. This can
1375 help find problems with drivers that do not properly initialize
1376 their sg tables.
1377
1378 If unsure, say N.
1379
Arjan van de Ven1b2439d2008-08-15 15:29:38 -07001380config DEBUG_NOTIFIERS
1381 bool "Debug notifier call chains"
1382 depends on DEBUG_KERNEL
1383 help
1384 Enable this to turn on sanity checking for notifier call chains.
1385 This is most useful for kernel developers to make sure that
1386 modules properly unregister themselves from notifier chains.
1387 This is a relatively cheap check but if you care about maximum
1388 performance, say N.
1389
Changbin Du3be5cbc2019-12-06 17:03:48 -08001390config BUG_ON_DATA_CORRUPTION
1391 bool "Trigger a BUG when data corruption is detected"
1392 select DEBUG_LIST
1393 help
1394 Select this option if the kernel should BUG when it encounters
1395 data corruption in kernel memory structures when they get checked
1396 for validity.
1397
1398 If unsure, say N.
1399
1400endmenu
1401
David Howellse0e81732009-09-02 09:13:40 +01001402config DEBUG_CREDENTIALS
1403 bool "Debug credential management"
1404 depends on DEBUG_KERNEL
1405 help
1406 Enable this to turn on some debug checking for credential
1407 management. The additional code keeps track of the number of
1408 pointers from task_structs to any given cred struct, and checks to
1409 see that this number never exceeds the usage count of the cred
1410 struct.
1411
1412 Furthermore, if SELinux is enabled, this also checks that the
1413 security pointer in the cred struct is never seen to be invalid.
1414
1415 If unsure, say N.
1416
Paul E. McKenney43a0a2a2017-05-17 09:19:44 -07001417source "kernel/rcu/Kconfig.debug"
Dave Hansen2f03e3c2013-01-07 08:19:23 -08001418
Tejun Heof303fccb2016-02-09 17:59:38 -05001419config DEBUG_WQ_FORCE_RR_CPU
1420 bool "Force round-robin CPU selection for unbound work items"
1421 depends on DEBUG_KERNEL
1422 default n
1423 help
1424 Workqueue used to implicitly guarantee that work items queued
1425 without explicit CPU specified are put on the local CPU. This
1426 guarantee is no longer true and while local CPU is still
1427 preferred work items may be put on foreign CPUs. Kernel
1428 parameter "workqueue.debug_force_rr_cpu" is added to force
1429 round-robin CPU selection to flush out usages which depend on the
1430 now broken guarantee. This config option enables the debug
1431 feature by default. When enabled, memory and cache locality will
1432 be impacted.
1433
Tejun Heo870d6652008-08-25 19:47:25 +09001434config DEBUG_BLOCK_EXT_DEVT
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -08001435 bool "Force extended block device numbers and spread them"
Tejun Heo870d6652008-08-25 19:47:25 +09001436 depends on DEBUG_KERNEL
1437 depends on BLOCK
Jens Axboe759f8ca2008-08-29 09:06:29 +02001438 default n
Tejun Heo870d6652008-08-25 19:47:25 +09001439 help
Tejun Heo0e11e342008-10-13 10:46:01 +02001440 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1441 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1442 YOU ARE DOING. Distros, please enable this and fix whatever
1443 is broken.
1444
Tejun Heo870d6652008-08-25 19:47:25 +09001445 Conventionally, block device numbers are allocated from
1446 predetermined contiguous area. However, extended block area
1447 may introduce non-contiguous block device numbers. This
1448 option forces most block device numbers to be allocated from
1449 the extended space and spreads them to discover kernel or
1450 userland code paths which assume predetermined contiguous
1451 device number allocation.
1452
Tejun Heo55dc7db2008-09-01 13:44:35 +02001453 Note that turning on this debug option shuffles all the
1454 device numbers for all IDE and SCSI devices including libata
1455 ones, so root partition specified using device number
1456 directly (via rdev or root=MAJ:MIN) won't work anymore.
1457 Textual device names (root=/dev/sdXn) will continue to work.
1458
Tejun Heo870d6652008-08-25 19:47:25 +09001459 Say N if you are unsure.
1460
Thomas Gleixner757c9892016-02-26 18:43:32 +00001461config CPU_HOTPLUG_STATE_CONTROL
1462 bool "Enable CPU hotplug state control"
1463 depends on DEBUG_KERNEL
1464 depends on HOTPLUG_CPU
1465 default n
1466 help
1467 Allows to write steps between "offline" and "online" to the CPUs
1468 sysfs target file so states can be stepped granular. This is a debug
1469 option for now as the hotplug machinery cannot be stopped and
1470 restarted at arbitrary points yet.
1471
1472 Say N if your are unsure.
1473
Changbin Du09a74952019-12-06 17:03:51 -08001474config LATENCYTOP
1475 bool "Latency measuring infrastructure"
1476 depends on DEBUG_KERNEL
1477 depends on STACKTRACE_SUPPORT
1478 depends on PROC_FS
1479 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1480 select KALLSYMS
1481 select KALLSYMS_ALL
1482 select STACKTRACE
1483 select SCHEDSTATS
1484 select SCHED_DEBUG
1485 help
1486 Enable this option if you want to use the LatencyTOP tool
1487 to find out which userspace is blocking on what kernel operations.
1488
1489source "kernel/trace/Kconfig"
1490
1491config PROVIDE_OHCI1394_DMA_INIT
1492 bool "Remote debugging over FireWire early on boot"
1493 depends on PCI && X86
1494 help
1495 If you want to debug problems which hang or crash the kernel early
1496 on boot and the crashing machine has a FireWire port, you can use
1497 this feature to remotely access the memory of the crashed machine
1498 over FireWire. This employs remote DMA as part of the OHCI1394
1499 specification which is now the standard for FireWire controllers.
1500
1501 With remote DMA, you can monitor the printk buffer remotely using
1502 firescope and access all memory below 4GB using fireproxy from gdb.
1503 Even controlling a kernel debugger is possible using remote DMA.
1504
1505 Usage:
1506
1507 If ohci1394_dma=early is used as boot parameter, it will initialize
1508 all OHCI1394 controllers which are found in the PCI config space.
1509
1510 As all changes to the FireWire bus such as enabling and disabling
1511 devices cause a bus reset and thereby disable remote DMA for all
1512 devices, be sure to have the cable plugged and FireWire enabled on
1513 the debugging host before booting the debug target for debugging.
1514
1515 This code (~1k) is freed after boot. By then, the firewire stack
1516 in charge of the OHCI-1394 controllers should be used instead.
1517
Mauro Carvalho Chehaba74e2a22020-05-01 17:37:50 +02001518 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
Changbin Du09a74952019-12-06 17:03:51 -08001519
Changbin Du045f6d72019-12-17 20:51:56 -08001520source "samples/Kconfig"
1521
1522config ARCH_HAS_DEVMEM_IS_ALLOWED
1523 bool
1524
1525config STRICT_DEVMEM
1526 bool "Filter access to /dev/mem"
1527 depends on MMU && DEVMEM
1528 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1529 default y if PPC || X86 || ARM64
1530 help
1531 If this option is disabled, you allow userspace (root) access to all
1532 of memory, including kernel and userspace memory. Accidental
1533 access to this is obviously disastrous, but specific access can
1534 be used by people debugging the kernel. Note that with PAT support
1535 enabled, even in this case there are restrictions on /dev/mem
1536 use due to the cache aliasing requirements.
1537
1538 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1539 file only allows userspace access to PCI space and the BIOS code and
1540 data regions. This is sufficient for dosemu and X and all common
1541 users of /dev/mem.
1542
1543 If in doubt, say Y.
1544
1545config IO_STRICT_DEVMEM
1546 bool "Filter I/O access to /dev/mem"
1547 depends on STRICT_DEVMEM
1548 help
1549 If this option is disabled, you allow userspace (root) access to all
1550 io-memory regardless of whether a driver is actively using that
1551 range. Accidental access to this is obviously disastrous, but
1552 specific access can be used by people debugging kernel drivers.
1553
1554 If this option is switched on, the /dev/mem file only allows
1555 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1556 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1557 if the driver using a given range cannot be disabled.
1558
1559 If in doubt, say Y.
1560
1561menu "$(SRCARCH) Debugging"
1562
1563source "arch/$(SRCARCH)/Kconfig.debug"
1564
1565endmenu
1566
1567menu "Kernel Testing and Coverage"
1568
Changbin Du09a74952019-12-06 17:03:51 -08001569source "lib/kunit/Kconfig"
1570
Akinobu Mita8d438282012-07-30 14:43:02 -07001571config NOTIFIER_ERROR_INJECTION
1572 tristate "Notifier error injection"
1573 depends on DEBUG_KERNEL
1574 select DEBUG_FS
1575 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001576 This option provides the ability to inject artificial errors to
Akinobu Mita8d438282012-07-30 14:43:02 -07001577 specified notifier chain callbacks. It is useful to test the error
1578 handling of notifier call chain failures.
1579
1580 Say N if unsure.
1581
Akinobu Mita048b9c32012-07-30 14:43:07 -07001582config PM_NOTIFIER_ERROR_INJECT
1583 tristate "PM notifier error injection module"
1584 depends on PM && NOTIFIER_ERROR_INJECTION
1585 default m if PM_DEBUG
1586 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001587 This option provides the ability to inject artificial errors to
Akinobu Mita048b9c32012-07-30 14:43:07 -07001588 PM notifier chain callbacks. It is controlled through debugfs
1589 interface /sys/kernel/debug/notifier-error-inject/pm
1590
1591 If the notifier call chain should be failed with some events
1592 notified, write the error code to "actions/<notifier event>/error".
1593
1594 Example: Inject PM suspend error (-12 = -ENOMEM)
1595
1596 # cd /sys/kernel/debug/notifier-error-inject/pm/
1597 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1598 # echo mem > /sys/power/state
1599 bash: echo: write error: Cannot allocate memory
1600
1601 To compile this code as a module, choose M here: the module will
1602 be called pm-notifier-error-inject.
1603
1604 If unsure, say N.
1605
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001606config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1607 tristate "OF reconfig notifier error injection module"
1608 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001609 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001610 This option provides the ability to inject artificial errors to
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001611 OF reconfig notifier chain callbacks. It is controlled
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001612 through debugfs interface under
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001613 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001614
1615 If the notifier call chain should be failed with some events
1616 notified, write the error code to "actions/<notifier event>/error".
1617
1618 To compile this code as a module, choose M here: the module will
Akinobu Mitae12a95f2013-04-30 15:28:49 -07001619 be called of-reconfig-notifier-error-inject.
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001620
1621 If unsure, say N.
1622
Nikolay Aleksandrov02fff962015-11-28 13:45:28 +01001623config NETDEV_NOTIFIER_ERROR_INJECT
1624 tristate "Netdev notifier error injection module"
1625 depends on NET && NOTIFIER_ERROR_INJECTION
1626 help
1627 This option provides the ability to inject artificial errors to
1628 netdevice notifier chain callbacks. It is controlled through debugfs
1629 interface /sys/kernel/debug/notifier-error-inject/netdev
1630
1631 If the notifier call chain should be failed with some events
1632 notified, write the error code to "actions/<notifier event>/error".
1633
1634 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1635
1636 # cd /sys/kernel/debug/notifier-error-inject/netdev
1637 # echo -22 > actions/NETDEV_CHANGEMTU/error
1638 # ip link set eth0 mtu 1024
1639 RTNETLINK answers: Invalid argument
1640
1641 To compile this code as a module, choose M here: the module will
1642 be called netdev-notifier-error-inject.
1643
1644 If unsure, say N.
1645
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001646config FUNCTION_ERROR_INJECTION
1647 def_bool y
1648 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1649
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001650config FAULT_INJECTION
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001651 bool "Fault-injection framework"
1652 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -08001653 help
1654 Provide fault-injection framework.
1655 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001656
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001657config FAILSLAB
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001658 bool "Fault-injection capability for kmalloc"
1659 depends on FAULT_INJECTION
Akinobu Mita773ff602008-12-23 19:37:01 +09001660 depends on SLAB || SLUB
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001661 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001662 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001663
Akinobu Mita933e3122006-12-08 02:39:45 -08001664config FAIL_PAGE_ALLOC
Qiujun Huang29b46fa2020-04-06 20:12:49 -07001665 bool "Fault-injection capability for alloc_pages()"
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001666 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -08001667 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001668 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -08001669
Akinobu Mitac17bb492006-12-08 02:39:46 -08001670config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +01001671 bool "Fault-injection capability for disk IO"
Jens Axboe581d4e22008-09-14 05:56:33 -07001672 depends on FAULT_INJECTION && BLOCK
Akinobu Mitac17bb492006-12-08 02:39:46 -08001673 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001674 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -08001675
Jens Axboe581d4e22008-09-14 05:56:33 -07001676config FAIL_IO_TIMEOUT
Takuya Yoshikawaf4d01432010-07-21 16:05:53 +09001677 bool "Fault-injection capability for faking disk interrupts"
Jens Axboe581d4e22008-09-14 05:56:33 -07001678 depends on FAULT_INJECTION && BLOCK
1679 help
1680 Provide fault-injection capability on end IO handling. This
1681 will make the block layer "forget" an interrupt as configured,
1682 thus exercising the error handling.
1683
1684 Only works with drivers that use the generic timeout handling,
1685 for others it wont do anything.
1686
Davidlohr Buesoab51fba2015-06-29 23:26:02 -07001687config FAIL_FUTEX
1688 bool "Fault-injection capability for futexes"
1689 select DEBUG_FS
1690 depends on FAULT_INJECTION && FUTEX
1691 help
1692 Provide fault-injection capability for futexes.
1693
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001694config FAULT_INJECTION_DEBUG_FS
1695 bool "Debugfs entries for fault-injection capabilities"
1696 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1697 help
1698 Enable configuration of fault-injection capabilities via debugfs.
1699
Masami Hiramatsu4b1a29a2018-01-13 02:56:03 +09001700config FAIL_FUNCTION
1701 bool "Fault-injection capability for functions"
1702 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1703 help
1704 Provide function-based fault-injection capability.
1705 This will allow you to override a specific function with a return
1706 with given return value. As a result, function caller will see
1707 an error value and have to handle it. This is useful to test the
1708 error handling in various subsystems.
1709
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001710config FAIL_MMC_REQUEST
1711 bool "Fault-injection capability for MMC IO"
1712 depends on FAULT_INJECTION_DEBUG_FS && MMC
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001713 help
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001714 Provide fault-injection capability for MMC IO.
1715 This will make the mmc core return data errors. This is
1716 useful to test the error handling in the mmc block device
1717 and to test how the mmc host driver handles retries from
1718 the block device.
Akinobu Mita1df49002007-02-20 13:57:56 -08001719
1720config FAULT_INJECTION_STACKTRACE_FILTER
1721 bool "stacktrace filter for fault-injection capabilities"
1722 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -07001723 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -08001724 select STACKTRACE
Stefan Agnerf9b58e82018-09-30 23:02:33 +01001725 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
Akinobu Mita1df49002007-02-20 13:57:56 -08001726 help
1727 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -07001728
Changbin Du09a74952019-12-06 17:03:51 -08001729config ARCH_HAS_KCOV
1730 bool
Arjan van de Ven97455122008-01-25 21:08:34 +01001731 help
Changbin Du09a74952019-12-06 17:03:51 -08001732 An architecture should select this when it can successfully
1733 build and run with CONFIG_KCOV. This typically requires
1734 disabling instrumentation for some early boot code.
Arjan van de Ven97455122008-01-25 21:08:34 +01001735
Changbin Du09a74952019-12-06 17:03:51 -08001736config CC_HAS_SANCOV_TRACE_PC
1737 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001738
Changbin Du09a74952019-12-06 17:03:51 -08001739
1740config KCOV
1741 bool "Code coverage for fuzzing"
1742 depends on ARCH_HAS_KCOV
1743 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1744 select DEBUG_FS
1745 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001746 help
Changbin Du09a74952019-12-06 17:03:51 -08001747 KCOV exposes kernel code coverage information in a form suitable
1748 for coverage-guided fuzzing (randomized testing).
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001749
Changbin Du09a74952019-12-06 17:03:51 -08001750 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1751 different machines and across reboots. If you need stable PC values,
1752 disable RANDOMIZE_BASE.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001753
Changbin Du09a74952019-12-06 17:03:51 -08001754 For more details, see Documentation/dev-tools/kcov.rst.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001755
Changbin Du09a74952019-12-06 17:03:51 -08001756config KCOV_ENABLE_COMPARISONS
1757 bool "Enable comparison operands collection by KCOV"
1758 depends on KCOV
1759 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1760 help
1761 KCOV also exposes operands of every comparison in the instrumented
1762 code along with operand sizes and PCs of the comparison instructions.
1763 These operands can be used by fuzzing engines to improve the quality
1764 of fuzzing coverage.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001765
Changbin Du09a74952019-12-06 17:03:51 -08001766config KCOV_INSTRUMENT_ALL
1767 bool "Instrument all code by default"
1768 depends on KCOV
1769 default y
1770 help
1771 If you are doing generic system call fuzzing (like e.g. syzkaller),
1772 then you will want to instrument the whole kernel and you should
1773 say y here. If you are doing more targeted fuzzing (like e.g.
1774 filesystem fuzzing with AFL) then you will want to enable coverage
1775 for more specific subsets of files, and should say n here.
Brendan Higgins84bc8092019-09-23 02:02:36 -07001776
Vincent Legolld3deafa2018-02-06 15:38:38 -08001777menuconfig RUNTIME_TESTING_MENU
1778 bool "Runtime Testing"
Anders Roxell908009e82018-02-21 14:46:05 -08001779 def_bool y
Vincent Legolld3deafa2018-02-06 15:38:38 -08001780
1781if RUNTIME_TESTING_MENU
Dave Hansen881c5142013-07-01 13:04:44 -07001782
1783config LKDTM
1784 tristate "Linux Kernel Dump Test Tool Module"
1785 depends on DEBUG_FS
Dave Hansen881c5142013-07-01 13:04:44 -07001786 help
1787 This module enables testing of the different dumping mechanisms by
1788 inducing system failures at predefined crash points.
1789 If you don't need it: say N
1790 Choose M here to compile this code as a module. The module will be
1791 called lkdtm.
1792
1793 Documentation on how to use the module can be found in
Mauro Carvalho Chehab10ffebb2019-06-12 14:52:44 -03001794 Documentation/fault-injection/provoke-crashes.rst
Dave Hansen881c5142013-07-01 13:04:44 -07001795
1796config TEST_LIST_SORT
Geert Uytterhoevene327fd72017-05-08 15:55:26 -07001797 tristate "Linked list sorting test"
1798 depends on DEBUG_KERNEL || m
Dave Hansen881c5142013-07-01 13:04:44 -07001799 help
1800 Enable this to turn on 'list_sort()' function test. This test is
Geert Uytterhoevene327fd72017-05-08 15:55:26 -07001801 executed only once during system boot (so affects only boot time),
1802 or at module load time.
Dave Hansen881c5142013-07-01 13:04:44 -07001803
1804 If unsure, say N.
1805
Ian Rogers6e246282020-02-13 23:51:29 -08001806config TEST_MIN_HEAP
1807 tristate "Min heap test"
1808 depends on DEBUG_KERNEL || m
1809 help
1810 Enable this to turn on min heap function tests. This test is
1811 executed only once during system boot (so affects only boot time),
1812 or at module load time.
1813
1814 If unsure, say N.
1815
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001816config TEST_SORT
Geert Uytterhoeven5c4e6792017-05-08 15:55:23 -07001817 tristate "Array-based sort test"
1818 depends on DEBUG_KERNEL || m
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001819 help
Geert Uytterhoeven5c4e6792017-05-08 15:55:23 -07001820 This option enables the self-test function of 'sort()' at boot,
1821 or at module load time.
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001822
1823 If unsure, say N.
1824
Dave Hansen881c5142013-07-01 13:04:44 -07001825config KPROBES_SANITY_TEST
1826 bool "Kprobes sanity tests"
1827 depends on DEBUG_KERNEL
1828 depends on KPROBES
Dave Hansen881c5142013-07-01 13:04:44 -07001829 help
1830 This option provides for testing basic kprobes functionality on
Masami Hiramatsu5a6cf772018-06-20 01:05:07 +09001831 boot. Samples of kprobe and kretprobe are inserted and
Dave Hansen881c5142013-07-01 13:04:44 -07001832 verified for functionality.
1833
1834 Say N if you are unsure.
1835
1836config BACKTRACE_SELF_TEST
1837 tristate "Self test for the backtrace code"
1838 depends on DEBUG_KERNEL
Dave Hansen881c5142013-07-01 13:04:44 -07001839 help
1840 This option provides a kernel module that can be used to test
1841 the kernel stack backtrace code. This option is not useful
1842 for distributions or general kernels, but only for kernel
1843 developers working on architecture code.
1844
1845 Note that if you want to also test saved backtraces, you will
1846 have to enable STACKTRACE as well.
1847
1848 Say N if you are unsure.
1849
Michel Lespinasse910a7422012-10-08 16:30:39 -07001850config RBTREE_TEST
1851 tristate "Red-Black tree test"
Cody P Schafer7c993e12013-09-11 14:25:19 -07001852 depends on DEBUG_KERNEL
Michel Lespinasse910a7422012-10-08 16:30:39 -07001853 help
1854 A benchmark measuring the performance of the rbtree library.
1855 Also includes rbtree invariant checks.
1856
Ferdinand Blomqvist4b4f3ac2019-06-20 17:10:33 +03001857config REED_SOLOMON_TEST
1858 tristate "Reed-Solomon library test"
1859 depends on DEBUG_KERNEL || m
1860 select REED_SOLOMON
1861 select REED_SOLOMON_ENC16
1862 select REED_SOLOMON_DEC16
1863 help
1864 This option enables the self-test function of rslib at boot,
1865 or at module load time.
1866
1867 If unsure, say N.
1868
Michel Lespinassefff3fd82012-10-08 16:31:23 -07001869config INTERVAL_TREE_TEST
1870 tristate "Interval tree test"
Davidlohr Bueso0f789b62017-07-10 15:51:43 -07001871 depends on DEBUG_KERNEL
Chris Wilsona88cc102014-03-17 12:21:54 +00001872 select INTERVAL_TREE
Michel Lespinassefff3fd82012-10-08 16:31:23 -07001873 help
1874 A benchmark measuring the performance of the interval tree library
1875
Greg Thelen623fd802013-11-12 15:08:34 -08001876config PERCPU_TEST
1877 tristate "Per cpu operations test"
1878 depends on m && DEBUG_KERNEL
1879 help
1880 Enable this option to build test module which validates per-cpu
1881 operations.
1882
1883 If unsure, say N.
1884
Dave Hansen881c5142013-07-01 13:04:44 -07001885config ATOMIC64_SELFTEST
Geert Uytterhoeven55ded952017-02-24 15:00:55 -08001886 tristate "Perform an atomic64_t self-test"
Dave Hansen881c5142013-07-01 13:04:44 -07001887 help
Geert Uytterhoeven55ded952017-02-24 15:00:55 -08001888 Enable this option to test the atomic64_t functions at boot or
1889 at module load time.
Dave Hansen881c5142013-07-01 13:04:44 -07001890
1891 If unsure, say N.
1892
1893config ASYNC_RAID6_TEST
1894 tristate "Self test for hardware accelerated raid6 recovery"
1895 depends on ASYNC_RAID6_RECOV
1896 select ASYNC_MEMCPY
1897 ---help---
1898 This is a one-shot self test that permutes through the
1899 recovery of all the possible two disk failure scenarios for a
1900 N-disk array. Recovery is performed with the asynchronous
1901 raid6 recovery routines, and will optionally use an offload
1902 engine if one is available.
1903
1904 If unsure, say N.
1905
Andy Shevchenko64d1d772015-02-12 15:02:21 -08001906config TEST_HEXDUMP
1907 tristate "Test functions located in the hexdump module at runtime"
1908
Dave Hansen881c5142013-07-01 13:04:44 -07001909config TEST_STRING_HELPERS
1910 tristate "Test functions located in the string_helpers module at runtime"
1911
Tobin C. Harding0b0600c2019-04-05 12:58:59 +11001912config TEST_STRSCPY
1913 tristate "Test strscpy*() family of functions at runtime"
1914
Dave Hansen881c5142013-07-01 13:04:44 -07001915config TEST_KSTRTOX
1916 tristate "Test kstrto*() family of functions at runtime"
1917
Rasmus Villemoes707cc722015-11-06 16:30:29 -08001918config TEST_PRINTF
1919 tristate "Test printf() family of functions at runtime"
1920
David Decotigny5fd003f2016-02-19 09:24:00 -05001921config TEST_BITMAP
1922 tristate "Test bitmap_*() family of functions at runtime"
David Decotigny5fd003f2016-02-19 09:24:00 -05001923 help
1924 Enable this option to test the bitmap functions at boot.
1925
1926 If unsure, say N.
1927
Johannes Berg0e2dc702018-06-20 08:58:30 +02001928config TEST_BITFIELD
1929 tristate "Test bitfield functions at runtime"
1930 help
1931 Enable this option to test the bitfield functions at boot.
1932
1933 If unsure, say N.
1934
Andy Shevchenkocfaff0e2016-05-30 17:40:41 +03001935config TEST_UUID
1936 tristate "Test functions located in the uuid module at runtime"
1937
Matthew Wilcoxad3d6c72017-11-07 14:57:46 -05001938config TEST_XARRAY
1939 tristate "Test the XArray code at runtime"
1940
Rasmus Villemoes455a35a2018-05-08 00:36:28 +02001941config TEST_OVERFLOW
1942 tristate "Test check_*_overflow() functions at runtime"
1943
Thomas Graf7e1e7762014-08-02 11:47:44 +02001944config TEST_RHASHTABLE
Geert Uytterhoeven9d6dbe12015-01-29 15:40:25 +01001945 tristate "Perform selftest on resizable hash table"
Thomas Graf7e1e7762014-08-02 11:47:44 +02001946 help
1947 Enable this option to test the rhashtable functions at boot.
1948
1949 If unsure, say N.
1950
George Spelvin468a9422016-05-26 22:11:51 -04001951config TEST_HASH
1952 tristate "Perform selftest on hash functions"
George Spelvin468a9422016-05-26 22:11:51 -04001953 help
Jason A. Donenfeld2c956a62017-01-08 13:54:00 +01001954 Enable this option to test the kernel's integer (<linux/hash.h>),
1955 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
1956 hash functions on boot (or module load).
George Spelvin468a9422016-05-26 22:11:51 -04001957
1958 This is intended to help people writing architecture-specific
1959 optimized versions. If unsure, say N.
1960
Matthew Wilcox8ab8ba32018-06-18 16:59:29 -04001961config TEST_IDA
1962 tristate "Perform selftest on IDA functions"
1963
Jiri Pirko44091d22017-02-03 10:29:06 +01001964config TEST_PARMAN
1965 tristate "Perform selftest on priority array manager"
Jiri Pirko44091d22017-02-03 10:29:06 +01001966 depends on PARMAN
1967 help
1968 Enable this option to test priority array manager on boot
1969 (or module load).
1970
1971 If unsure, say N.
1972
Daniel Lezcano6aed82d2019-05-27 22:55:19 +02001973config TEST_IRQ_TIMINGS
1974 bool "IRQ timings selftest"
1975 depends on IRQ_TIMINGS
1976 help
1977 Enable this option to test the irq timings code on boot.
1978
1979 If unsure, say N.
1980
Valentin Rothberg8a6f0b42014-10-13 15:51:38 -07001981config TEST_LKM
Kees Cook93e9ef82014-01-23 15:54:37 -08001982 tristate "Test module loading with 'hello world' module"
Kees Cook93e9ef82014-01-23 15:54:37 -08001983 depends on m
1984 help
1985 This builds the "test_module" module that emits "Hello, world"
1986 on printk when loaded. It is designed to be used for basic
1987 evaluation of the module loading subsystem (for example when
1988 validating module verification). It lacks any extra dependencies,
1989 and will not normally be loaded by the system unless explicitly
1990 requested by name.
1991
1992 If unsure, say N.
1993
Uladzislau Rezki (Sony)3f21a6b2019-03-05 15:43:34 -08001994config TEST_VMALLOC
1995 tristate "Test module for stress/performance analysis of vmalloc allocator"
1996 default n
1997 depends on MMU
1998 depends on m
1999 help
2000 This builds the "test_vmalloc" module that should be used for
2001 stress and performance analysis. So, any new change for vmalloc
2002 subsystem can be evaluated from performance and stability point
2003 of view.
2004
2005 If unsure, say N.
2006
Kees Cook3e2a4c12014-01-23 15:54:38 -08002007config TEST_USER_COPY
2008 tristate "Test user/kernel boundary protections"
Kees Cook3e2a4c12014-01-23 15:54:38 -08002009 depends on m
2010 help
2011 This builds the "test_user_copy" module that runs sanity checks
2012 on the copy_to/from_user infrastructure, making sure basic
2013 user/kernel boundary testing is working. If it fails to load,
2014 a regression has been detected in the user/kernel memory boundary
2015 protections.
2016
2017 If unsure, say N.
2018
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002019config TEST_BPF
2020 tristate "Test BPF filter functionality"
Randy Dunlap98920ba2014-05-13 09:58:44 -07002021 depends on m && NET
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002022 help
2023 This builds the "test_bpf" module that runs various test vectors
2024 against the BPF interpreter or BPF JIT compiler depending on the
2025 current setting. This is in particular useful for BPF JIT compiler
2026 development, but also to run regression tests against changes in
Alexei Starovoitov3c731eb2014-09-26 00:17:07 -07002027 the interpreter code. It also enables test stubs for eBPF maps and
2028 verifier used by user space verifier testsuite.
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002029
2030 If unsure, say N.
2031
Mahesh Bandewar509e56b2019-07-01 14:39:01 -07002032config TEST_BLACKHOLE_DEV
2033 tristate "Test blackhole netdev functionality"
2034 depends on m && NET
2035 help
2036 This builds the "test_blackhole_dev" module that validates the
2037 data path through this blackhole netdev.
2038
2039 If unsure, say N.
2040
Yury Norovdceeb3e2018-02-06 15:38:27 -08002041config FIND_BIT_BENCHMARK
Yury Norov4441fca2017-11-17 15:28:31 -08002042 tristate "Test find_bit functions"
Yury Norov4441fca2017-11-17 15:28:31 -08002043 help
2044 This builds the "test_find_bit" module that measure find_*_bit()
2045 functions performance.
2046
2047 If unsure, say N.
2048
Kees Cook0a8adf52014-07-14 14:38:12 -07002049config TEST_FIRMWARE
2050 tristate "Test firmware loading via userspace interface"
Kees Cook0a8adf52014-07-14 14:38:12 -07002051 depends on FW_LOADER
2052 help
2053 This builds the "test_firmware" module that creates a userspace
2054 interface for testing firmware loading. This can be used to
2055 control the triggering of firmware loading without needing an
2056 actual firmware-using device. The contents can be rechecked by
2057 userspace.
2058
2059 If unsure, say N.
2060
Luis R. Rodriguez9308f2f2017-07-12 14:33:43 -07002061config TEST_SYSCTL
2062 tristate "sysctl test driver"
Luis R. Rodriguez9308f2f2017-07-12 14:33:43 -07002063 depends on PROC_SYSCTL
2064 help
2065 This builds the "test_sysctl" module. This driver enables to test the
2066 proc sysctl interfaces available to drivers safely without affecting
2067 production knobs which might alter system functionality.
2068
2069 If unsure, say N.
2070
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002071config SYSCTL_KUNIT_TEST
Alan Maguirec475c772020-01-06 22:28:20 +00002072 tristate "KUnit test for sysctl"
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002073 depends on KUNIT
2074 help
2075 This builds the proc sysctl unit test, which runs on boot.
2076 Tests the API contract and implementation correctness of sysctl.
2077 For more information on KUnit and unit tests in general please refer
2078 to the KUnit documentation in Documentation/dev-tools/kunit/.
2079
2080 If unsure, say N.
2081
David Gowea2dd7c2019-10-24 15:46:31 -07002082config LIST_KUNIT_TEST
Alan Maguirec475c772020-01-06 22:28:20 +00002083 tristate "KUnit Test for Kernel Linked-list structures"
David Gowea2dd7c2019-10-24 15:46:31 -07002084 depends on KUNIT
2085 help
2086 This builds the linked list KUnit test suite.
2087 It tests that the API and basic functionality of the list_head type
2088 and associated macros.
2089
2090 KUnit tests run during boot and output the results to the debug log
2091 in TAP format (http://testanything.org/). Only useful for kernel devs
2092 running the KUnit test harness, and not intended for inclusion into a
2093 production build.
2094
2095 For more information on KUnit and unit tests in general please refer
2096 to the KUnit documentation in Documentation/dev-tools/kunit/.
2097
2098 If unsure, say N.
2099
Matti Vaittinen33d599f2020-05-08 18:40:43 +03002100config LINEAR_RANGES_TEST
2101 tristate "KUnit test for linear_ranges"
2102 depends on KUNIT
2103 select LINEAR_RANGES
2104 help
2105 This builds the linear_ranges unit test, which runs on boot.
2106 Tests the linear_ranges logic correctness.
2107 For more information on KUnit and unit tests in general please refer
2108 to the KUnit documentation in Documentation/dev-tools/kunit/.
2109
2110 If unsure, say N.
2111
David Rileye704f932014-06-16 14:58:32 -07002112config TEST_UDELAY
2113 tristate "udelay test driver"
David Rileye704f932014-06-16 14:58:32 -07002114 help
2115 This builds the "udelay_test" module that helps to make sure
2116 that udelay() is working properly.
2117
2118 If unsure, say N.
2119
Ingo Molnar2bf9e0a2015-08-03 11:42:57 +02002120config TEST_STATIC_KEYS
2121 tristate "Test static keys"
Jason Baron579e1ac2015-07-30 03:59:44 +00002122 depends on m
2123 help
Ingo Molnar2bf9e0a2015-08-03 11:42:57 +02002124 Test the static key interfaces.
Jason Baron579e1ac2015-07-30 03:59:44 +00002125
2126 If unsure, say N.
2127
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002128config TEST_KMOD
2129 tristate "kmod stress tester"
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002130 depends on m
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002131 depends on NETDEVICES && NET_CORE && INET # for TUN
YueHaibingae3d6a32019-04-25 22:23:44 -07002132 depends on BLOCK
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002133 select TEST_LKM
2134 select XFS_FS
2135 select TUN
2136 select BTRFS_FS
2137 help
2138 Test the kernel's module loading mechanism: kmod. kmod implements
2139 support to load modules using the Linux kernel's usermode helper.
2140 This test provides a series of tests against kmod.
2141
2142 Although technically you can either build test_kmod as a module or
2143 into the kernel we disallow building it into the kernel since
2144 it stress tests request_module() and this will very likely cause
2145 some issues by taking over precious threads available from other
2146 module load requests, ultimately this could be fatal.
2147
2148 To run tests run:
2149
2150 tools/testing/selftests/kmod/kmod.sh --help
2151
2152 If unsure, say N.
2153
Florian Fainellie4dace32017-09-08 16:15:31 -07002154config TEST_DEBUG_VIRTUAL
2155 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2156 depends on DEBUG_VIRTUAL
2157 help
2158 Test the kernel's ability to detect incorrect calls to
2159 virt_to_phys() done against the non-linear part of the
2160 kernel's virtual address map.
2161
2162 If unsure, say N.
2163
Alexander Shishkince76d932018-10-05 15:43:05 +03002164config TEST_MEMCAT_P
2165 tristate "Test memcat_p() helper function"
2166 help
2167 Test the memcat_p() helper for correctly merging two
2168 pointer arrays together.
2169
2170 If unsure, say N.
2171
Joe Lawrencea2818ee2019-01-09 13:43:29 +01002172config TEST_LIVEPATCH
2173 tristate "Test livepatching"
2174 default n
Joe Lawrencebae05432019-01-31 11:41:24 -05002175 depends on DYNAMIC_DEBUG
Joe Lawrencea2818ee2019-01-09 13:43:29 +01002176 depends on LIVEPATCH
2177 depends on m
2178 help
2179 Test kernel livepatching features for correctness. The tests will
2180 load test modules that will be livepatched in various scenarios.
2181
2182 To run all the livepatching tests:
2183
2184 make -C tools/testing/selftests TARGETS=livepatch run_tests
2185
2186 Alternatively, individual tests may be invoked:
2187
2188 tools/testing/selftests/livepatch/test-callbacks.sh
2189 tools/testing/selftests/livepatch/test-livepatch.sh
2190 tools/testing/selftests/livepatch/test-shadow-vars.sh
2191
2192 If unsure, say N.
2193
Jiri Pirko0a020d42018-11-14 08:22:28 +00002194config TEST_OBJAGG
2195 tristate "Perform selftest on object aggreration manager"
2196 default n
2197 depends on OBJAGG
2198 help
2199 Enable this option to test object aggregation manager on boot
2200 (or module load).
2201
Jiri Pirko0a020d42018-11-14 08:22:28 +00002202
Kees Cook50ceaa95e2019-01-23 12:24:32 -07002203config TEST_STACKINIT
2204 tristate "Test level of stack variable initialization"
2205 help
2206 Test if the kernel is zero-initializing stack variables and
2207 padding. Coverage is controlled by compiler flags,
2208 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2209 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2210
2211 If unsure, say N.
2212
Alexander Potapenko5015a302019-07-16 16:27:27 -07002213config TEST_MEMINIT
2214 tristate "Test heap/page initialization"
2215 help
2216 Test if the kernel is zero-initializing heap and page allocations.
2217 This can be useful to test init_on_alloc and init_on_free features.
2218
2219 If unsure, say N.
2220
Ralph Campbellb2ef9f52020-04-22 12:50:26 -07002221config TEST_HMM
2222 tristate "Test HMM (Heterogeneous Memory Management)"
2223 depends on TRANSPARENT_HUGEPAGE
2224 depends on DEVICE_PRIVATE
2225 select HMM_MIRROR
2226 select MMU_NOTIFIER
2227 help
2228 This is a pseudo device driver solely for testing HMM.
2229 Say M here if you want to build the HMM test module.
2230 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2231
2232 If unsure, say N.
2233
Vincent Legolld3deafa2018-02-06 15:38:38 -08002234endif # RUNTIME_TESTING_MENU
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002235
2236config MEMTEST
2237 bool "Memtest"
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002238 ---help---
2239 This option adds a kernel parameter 'memtest', which allows memtest
2240 to be set.
2241 memtest=0, mean disabled; -- default
2242 memtest=1, mean do 1 test pattern;
2243 ...
2244 memtest=17, mean do 17 test patterns.
2245 If you are unsure how to answer this question, answer N.
2246
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002247
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002248
Branden Bonabyaf9ca6f2019-10-03 17:01:49 -04002249config HYPERV_TESTING
2250 bool "Microsoft Hyper-V driver testing"
2251 default n
2252 depends on HYPERV && DEBUG_FS
2253 help
2254 Select this option to enable Hyper-V vmbus testing.
2255
Changbin Du045f6d72019-12-17 20:51:56 -08002256endmenu # "Kernel Testing and Coverage"
2257
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002258endmenu # Kernel hacking