blob: 50c1f5f08e6f17952295dd561e519299776423ae [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
245 help
246 Generate deduplicated BTF type information from DWARF debug info.
247 Turning this on expects presence of pahole tool, which will convert
248 DWARF type info into equivalent deduplicated BTF type info.
249
Jan Kiszka3ee7b3f2015-02-17 13:46:36 -0800250config GDB_SCRIPTS
251 bool "Provide GDB scripts for kernel debugging"
252 depends on DEBUG_INFO
253 help
254 This creates the required links to GDB helper scripts in the
255 build directory. If you load vmlinux into gdb, the helper
256 scripts will be automatically imported by gdb as well, and
257 additional functions are available to analyze a Linux kernel
Andreas Platschek700199b02016-12-14 15:05:40 -0800258 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
259 for further details.
Jan Kiszka3ee7b3f2015-02-17 13:46:36 -0800260
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700261config ENABLE_MUST_CHECK
262 bool "Enable __must_check logic"
263 default y
264 help
265 Enable the __must_check logic in the kernel build. Disable this to
266 suppress the "warning: ignoring return value of 'foo', declared with
267 attribute warn_unused_result" messages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
Andi Kleen35bb5b12008-02-22 15:15:03 +0100269config FRAME_WARN
Masahiro Yamadaa83e4ca2020-02-17 00:19:36 +0900270 int "Warn for stack frames larger than"
Andi Kleen35bb5b12008-02-22 15:15:03 +0100271 range 0 8192
Kees Cook0e07f662016-10-27 17:46:41 -0700272 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
Helge Deller432654d2017-09-11 21:41:43 +0200273 default 1280 if (!64BIT && PARISC)
274 default 1024 if (!64BIT && !PARISC)
Andi Kleen35bb5b12008-02-22 15:15:03 +0100275 default 2048 if 64BIT
276 help
277 Tell gcc to warn at build time for stack frames larger than this.
278 Setting this too low will cause a lot of warnings.
279 Setting it to 0 disables the warning.
Andi Kleen35bb5b12008-02-22 15:15:03 +0100280
Randy Dunlap99657c72009-09-18 12:49:22 -0700281config STRIP_ASM_SYMS
282 bool "Strip assembler-generated symbols during link"
283 default n
284 help
285 Strip internal assembler-generated symbols during a link (symbols
286 that look like '.Lxxx') so they don't pollute the output of
287 get_wchan() and suchlike.
288
Andi Kleen1873e872012-03-28 11:51:18 -0700289config READABLE_ASM
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800290 bool "Generate readable assembler code"
291 depends on DEBUG_KERNEL
Don Mullisbf4735a2006-12-10 02:18:37 -0800292 help
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800293 Disable some compiler optimizations that tend to generate human unreadable
294 assembler output. This may make the kernel slightly slower, but it helps
295 to keep kernel developers who have to stare a lot at assembler listings
296 sane.
Don Mullisbf4735a2006-12-10 02:18:37 -0800297
Masahiro Yamadae949f4c2019-06-04 19:13:59 +0900298config HEADERS_INSTALL
299 bool "Install uapi headers to usr/include"
Don Mullisbf4735a2006-12-10 02:18:37 -0800300 depends on !UML
301 help
Masahiro Yamadae949f4c2019-06-04 19:13:59 +0900302 This option will install uapi headers (headers exported to user-space)
303 into the usr/include directory for use during the kernel build.
304 This is unneeded for building the kernel itself, but needed for some
305 user-space program samples. It is also needed by some features such
306 as uapi header sanity checks.
307
Sam Ravnborg91341d42008-01-21 21:31:44 +0100308config DEBUG_SECTION_MISMATCH
309 bool "Enable full Section mismatch analysis"
Sam Ravnborg91341d42008-01-21 21:31:44 +0100310 help
311 The section mismatch analysis checks if there are illegal
312 references from one section to another section.
Michael Wittene809ab02011-04-17 04:08:48 +0000313 During linktime or runtime, some sections are dropped;
314 any use of code/data previously in these sections would
Sam Ravnborg91341d42008-01-21 21:31:44 +0100315 most likely result in an oops.
Michael Wittene809ab02011-04-17 04:08:48 +0000316 In the code, functions and variables are annotated with
Paul Gortmaker0db06282013-06-19 14:53:51 -0400317 __init,, etc. (see the full list in include/linux/init.h),
Geert Uytterhoevend6fbfa42008-01-30 11:13:23 +0100318 which results in the code/data being placed in specific sections.
Michael Wittene809ab02011-04-17 04:08:48 +0000319 The section mismatch analysis is always performed after a full
320 kernel build, and enabling this option causes the following
Masahiro Yamadab7dca6d2019-07-17 15:17:57 +0900321 additional step to occur:
Michael Wittene809ab02011-04-17 04:08:48 +0000322 - Add the option -fno-inline-functions-called-once to gcc commands.
323 When inlining a function annotated with __init in a non-init
324 function, we would lose the section information and thus
Sam Ravnborg91341d42008-01-21 21:31:44 +0100325 the analysis would not catch the illegal reference.
Michael Wittene809ab02011-04-17 04:08:48 +0000326 This option tells gcc to inline less (but it does result in
327 a larger kernel).
Sam Ravnborg91341d42008-01-21 21:31:44 +0100328
Nicolas Boichat47490ec2015-10-06 09:44:42 +1030329config SECTION_MISMATCH_WARN_ONLY
330 bool "Make section mismatch errors non-fatal"
331 default y
332 help
333 If you say N here, the build process will fail if there are any
334 section mismatch, instead of just throwing warnings.
335
336 If unsure, say Y.
337
Dave Hansen6dfc0662013-07-01 13:04:46 -0700338#
339# Select this config option from the architecture Kconfig, if it
340# is preferred to always offer frame pointers as a config
341# option on the architecture (regardless of KERNEL_DEBUG):
342#
343config ARCH_WANT_FRAME_POINTERS
344 bool
Dave Hansen6dfc0662013-07-01 13:04:46 -0700345
346config FRAME_POINTER
347 bool "Compile the kernel with frame pointers"
Arnd Bergmanna687a532018-03-07 23:30:54 +0100348 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
Dave Hansen6dfc0662013-07-01 13:04:46 -0700349 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
350 help
351 If you say Y here the resulting kernel image will be slightly
352 larger and slower, but it gives very useful debugging information
353 in case of kernel bugs. (precise oopses/stacktraces/warnings)
354
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -0600355config STACK_VALIDATION
356 bool "Compile-time stack metadata validation"
357 depends on HAVE_STACK_VALIDATION
358 default n
359 help
360 Add compile-time checks to validate stack metadata, including frame
361 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
362 that runtime stack traces are more reliable.
363
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500364 This is also a prerequisite for generation of ORC unwind data, which
Josh Poimboeuf11af8472017-10-13 15:02:00 -0500365 is needed for CONFIG_UNWINDER_ORC.
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500366
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -0600367 For more information, see
368 tools/objtool/Documentation/stack-validation.txt.
369
Dave Hansen6dfc0662013-07-01 13:04:46 -0700370config DEBUG_FORCE_WEAK_PER_CPU
371 bool "Force weak per-cpu definitions"
372 depends on DEBUG_KERNEL
373 help
374 s390 and alpha require percpu variables in modules to be
375 defined weak to work around addressing range issue which
376 puts the following two restrictions on percpu variable
377 definitions.
378
379 1. percpu symbols must be unique whether static or not
380 2. percpu variables can't be defined inside a function
381
382 To ensure that generic code follows the above rules, this
383 option forces all percpu variables to be defined as weak.
384
385endmenu # "Compiler options"
386
Changbin Du6210b642019-12-06 17:03:42 -0800387menu "Generic Kernel Debugging Instruments"
388
Dave Hansen6dfc0662013-07-01 13:04:46 -0700389config MAGIC_SYSRQ
390 bool "Magic SysRq key"
391 depends on !UML
392 help
393 If you say Y here, you will have some control over the system even
394 if the system crashes for example during kernel debugging (e.g., you
395 will be able to flush the buffer cache to disk, reboot the system
396 immediately or dump some status information). This is accomplished
397 by pressing various keys while holding SysRq (Alt+PrintScreen). It
398 also works on a serial console (on PC hardware at least), if you
399 send a BREAK and then within 5 seconds a command keypress. The
Hans Holmbergf8998c22017-03-16 09:37:32 +0100400 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
401 Don't say Y unless you really know what this hack does.
Dave Hansen6dfc0662013-07-01 13:04:46 -0700402
Ben Hutchings8eaede42013-10-07 01:05:46 +0100403config MAGIC_SYSRQ_DEFAULT_ENABLE
404 hex "Enable magic SysRq key functions by default"
405 depends on MAGIC_SYSRQ
406 default 0x1
407 help
408 Specifies which SysRq key functions are enabled by default.
409 This may be set to 1 or 0 to enable or disable them all, or
Hans Holmbergf8998c22017-03-16 09:37:32 +0100410 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
Ben Hutchings8eaede42013-10-07 01:05:46 +0100411
Felix Fietkau732dbf32016-12-22 08:31:34 +0100412config MAGIC_SYSRQ_SERIAL
413 bool "Enable magic SysRq key over serial"
414 depends on MAGIC_SYSRQ
415 default y
416 help
417 Many embedded boards have a disconnected TTL level serial which can
418 generate some garbage that can lead to spurious false sysrq detects.
419 This option allows you to decide whether you want to enable the
420 magic SysRq key.
421
Dmitry Safonov68af4312020-03-02 17:51:35 +0000422config MAGIC_SYSRQ_SERIAL_SEQUENCE
423 string "Char sequence that enables magic SysRq over serial"
424 depends on MAGIC_SYSRQ_SERIAL
425 default ""
426 help
427 Specifies a sequence of characters that can follow BREAK to enable
428 SysRq on a serial console.
429
Dmitry Safonovd3394b32020-03-06 15:31:56 +0000430 If unsure, leave an empty string and the option will not be enabled.
431
Changbin Duec29a5c2019-12-06 17:04:06 -0800432config DEBUG_FS
433 bool "Debug Filesystem"
434 help
435 debugfs is a virtual file system that kernel developers use to put
436 debugging files into. Enable this option to be able to read and
437 write to these files.
438
439 For detailed documentation on the debugfs API, see
440 Documentation/filesystems/.
441
442 If unsure, say N.
443
Changbin Du6210b642019-12-06 17:03:42 -0800444source "lib/Kconfig.kgdb"
445
446source "lib/Kconfig.ubsan"
447
448endmenu
449
Adrian Bunkf346f4b2006-01-09 20:54:51 -0800450config DEBUG_KERNEL
451 bool "Kernel debugging"
452 help
453 Say Y here if you are developing drivers or trying to debug and
454 identify kernel problems.
455
Sinan Kayac66d7a22019-05-14 15:44:00 -0700456config DEBUG_MISC
457 bool "Miscellaneous debug code"
458 default DEBUG_KERNEL
459 depends on DEBUG_KERNEL
460 help
461 Say Y here if you need to enable miscellaneous debug code that should
462 be under a more specific debug option but isn't.
463
464
Dave Hansen0610c8a2013-07-01 13:04:43 -0700465menu "Memory Debugging"
David Woodhousea304e1b2007-02-12 00:52:00 -0800466
Masahiro Yamada8636a1f2018-12-11 20:01:04 +0900467source "mm/Kconfig.debug"
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800468
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700469config DEBUG_OBJECTS
470 bool "Debug object operations"
471 depends on DEBUG_KERNEL
472 help
473 If you say Y here, additional code will be inserted into the
474 kernel to track the life time of various objects and validate
475 the operations on those objects.
476
477config DEBUG_OBJECTS_SELFTEST
478 bool "Debug objects selftest"
479 depends on DEBUG_OBJECTS
480 help
481 This enables the selftest of the object debug code.
482
483config DEBUG_OBJECTS_FREE
484 bool "Debug objects in freed memory"
485 depends on DEBUG_OBJECTS
486 help
487 This enables checks whether a k/v free operation frees an area
488 which contains an object which has not been deactivated
489 properly. This can make kmalloc/kfree-intensive workloads
490 much slower.
491
Thomas Gleixnerc6f3a972008-04-30 00:55:03 -0700492config DEBUG_OBJECTS_TIMERS
493 bool "Debug timer objects"
494 depends on DEBUG_OBJECTS
495 help
496 If you say Y here, additional code will be inserted into the
497 timer routines to track the life time of timer objects and
498 validate the timer operations.
499
Thomas Gleixnerdc186ad2009-11-16 01:09:48 +0900500config DEBUG_OBJECTS_WORK
501 bool "Debug work objects"
502 depends on DEBUG_OBJECTS
503 help
504 If you say Y here, additional code will be inserted into the
505 work queue routines to track the life time of work objects and
506 validate the work operations.
507
Mathieu Desnoyers551d55a2010-04-17 08:48:42 -0400508config DEBUG_OBJECTS_RCU_HEAD
509 bool "Debug RCU callbacks objects"
Mathieu Desnoyersfc2ecf72011-02-23 09:42:14 -0800510 depends on DEBUG_OBJECTS
Mathieu Desnoyers551d55a2010-04-17 08:48:42 -0400511 help
512 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
513
Tejun Heoe2852ae2010-10-26 14:23:05 -0700514config DEBUG_OBJECTS_PERCPU_COUNTER
515 bool "Debug percpu counter objects"
516 depends on DEBUG_OBJECTS
517 help
518 If you say Y here, additional code will be inserted into the
519 percpu counter routines to track the life time of percpu counter
520 objects and validate the percpu counter operations.
521
Ingo Molnar3ae70202008-11-26 10:02:00 +0100522config DEBUG_OBJECTS_ENABLE_DEFAULT
523 int "debug_objects bootup default value (0-1)"
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800524 range 0 1
525 default "1"
526 depends on DEBUG_OBJECTS
527 help
528 Debug objects boot parameter default value
Ingo Molnar3ae70202008-11-26 10:02:00 +0100529
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530config DEBUG_SLAB
Andrew Morton4a2f0ac2006-03-25 03:07:22 -0800531 bool "Debug slab memory allocations"
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -0800532 depends on DEBUG_KERNEL && SLAB
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 help
534 Say Y here to have the kernel do limited verification on memory
535 allocation as well as poisoning memory on free to catch use of freed
536 memory. This can make kmalloc/kfree-intensive workloads much slower.
537
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700538config SLUB_DEBUG_ON
539 bool "SLUB debugging on by default"
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -0800540 depends on SLUB && SLUB_DEBUG
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700541 default n
542 help
543 Boot with debugging on by default. SLUB boots by default with
544 the runtime debug capabilities switched off. Enabling this is
545 equivalent to specifying the "slub_debug" parameter on boot.
546 There is no support for more fine grained debug control like
547 possible with slub_debug=xxx. SLUB debugging may be switched
548 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
549 "slub_debug=-".
550
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800551config SLUB_STATS
552 default n
553 bool "Enable SLUB performance statistics"
Christoph Lameterab4d5ed2010-10-05 13:57:26 -0500554 depends on SLUB && SYSFS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800555 help
556 SLUB statistics are useful to debug SLUBs allocation behavior in
557 order find ways to optimize the allocator. This should never be
558 enabled for production use since keeping statistics slows down
559 the allocator by a few percentage points. The slabinfo command
560 supports the determination of the most active slabs to figure
561 out which slabs are relevant to a particular load.
562 Try running: slabinfo -DA
563
Catalin Marinasb69ec422012-10-08 16:28:11 -0700564config HAVE_DEBUG_KMEMLEAK
565 bool
566
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100567config DEBUG_KMEMLEAK
568 bool "Kernel memory leak detector"
Kees Cook525c1f92013-01-16 18:54:16 -0800569 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
Catalin Marinas79e0d9b2011-04-27 17:06:19 +0100570 select DEBUG_FS
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100571 select STACKTRACE if STACKTRACE_SUPPORT
572 select KALLSYMS
Randy Dunlapb60e26a2009-11-06 15:33:45 -0800573 select CRC32
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100574 help
575 Say Y here if you want to enable the memory leak
576 detector. The memory allocation/freeing is traced in a way
577 similar to the Boehm's conservative garbage collector, the
578 difference being that the orphan objects are not freed but
579 only shown in /sys/kernel/debug/kmemleak. Enabling this
580 feature will introduce an overhead to memory
Andreas Platschek700199b02016-12-14 15:05:40 -0800581 allocations. See Documentation/dev-tools/kmemleak.rst for more
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100582 details.
583
Catalin Marinasbf96d1e2009-06-23 14:40:27 +0100584 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
585 of finding leaks due to the slab objects poisoning.
586
Catalin Marinas3bba00d2009-06-11 13:24:13 +0100587 In order to access the kmemleak file, debugfs needs to be
588 mounted (usually at /sys/kernel/debug).
589
Catalin Marinasc5665862019-09-23 15:34:05 -0700590config DEBUG_KMEMLEAK_MEM_POOL_SIZE
591 int "Kmemleak memory pool size"
Catalin Marinasa9d90582009-06-25 10:16:11 +0100592 depends on DEBUG_KMEMLEAK
Qian Caic59180a2019-09-23 15:34:10 -0700593 range 200 1000000
Nicolas Boichatb751c522019-09-23 15:33:55 -0700594 default 16000
Catalin Marinasa9d90582009-06-25 10:16:11 +0100595 help
596 Kmemleak must track all the memory allocations to avoid
597 reporting false positives. Since memory may be allocated or
Catalin Marinasc5665862019-09-23 15:34:05 -0700598 freed before kmemleak is fully initialised, use a static pool
599 of metadata objects to track such callbacks. After kmemleak is
600 fully initialised, this memory pool acts as an emergency one
601 if slab allocations fail.
Catalin Marinasa9d90582009-06-25 10:16:11 +0100602
Catalin Marinas0822ee42009-06-11 13:24:14 +0100603config DEBUG_KMEMLEAK_TEST
604 tristate "Simple test for the kernel memory leak detector"
Daniel Baluta97182692011-04-04 15:06:44 -0700605 depends on DEBUG_KMEMLEAK && m
Catalin Marinas0822ee42009-06-11 13:24:14 +0100606 help
Daniel Baluta97182692011-04-04 15:06:44 -0700607 This option enables a module that explicitly leaks memory.
Catalin Marinas0822ee42009-06-11 13:24:14 +0100608
609 If unsure, say N.
610
Jason Baronab0155a2010-07-19 11:54:17 +0100611config DEBUG_KMEMLEAK_DEFAULT_OFF
612 bool "Default kmemleak to off"
613 depends on DEBUG_KMEMLEAK
614 help
615 Say Y here to disable kmemleak by default. It can then be enabled
616 on the command line via kmemleak=on.
617
Sri Krishna chowdaryd53ce042018-12-28 00:38:54 -0800618config DEBUG_KMEMLEAK_AUTO_SCAN
619 bool "Enable kmemleak auto scan thread on boot up"
620 default y
621 depends on DEBUG_KMEMLEAK
622 help
623 Depending on the cpu, kmemleak scan may be cpu intensive and can
624 stall user tasks at times. This option enables/disables automatic
625 kmemleak scan at boot up.
626
627 Say N here to disable kmemleak auto scan thread to stop automatic
628 scanning. Disabling this option disables automatic reporting of
629 memory leaks.
630
631 If unsure, say Y.
632
Dave Hansen0610c8a2013-07-01 13:04:43 -0700633config DEBUG_STACK_USAGE
634 bool "Stack utilization instrumentation"
Helge Deller6c31da32016-03-19 17:54:10 +0100635 depends on DEBUG_KERNEL && !IA64
Dave Hansen0610c8a2013-07-01 13:04:43 -0700636 help
637 Enables the display of the minimum amount of free stack which each
638 task has ever had available in the sysrq-T and sysrq-P debug output.
639
640 This option will slow down process creation somewhat.
641
Changbin Dudc9b9632019-12-06 17:03:57 -0800642config SCHED_STACK_END_CHECK
643 bool "Detect stack corruption on calls to schedule()"
644 depends on DEBUG_KERNEL
645 default n
646 help
647 This option checks for a stack overrun on calls to schedule().
648 If the stack end location is found to be over written always panic as
649 the content of the corrupted region can no longer be trusted.
650 This is to ensure no erroneous behaviour occurs which could result in
651 data corruption or a sporadic crash at a later stage once the region
652 is examined. The runtime overhead introduced is minimal.
653
Dave Hansen0610c8a2013-07-01 13:04:43 -0700654config DEBUG_VM
655 bool "Debug VM"
656 depends on DEBUG_KERNEL
657 help
658 Enable this to turn on extended checks in the virtual-memory system
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -0800659 that may impact performance.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700660
661 If unsure, say N.
662
Davidlohr Bueso4f115142014-06-04 16:06:46 -0700663config DEBUG_VM_VMACACHE
664 bool "Debug VMA caching"
665 depends on DEBUG_VM
666 help
667 Enable this to turn on VMA caching debug information. Doing so
668 can cause significant overhead, so only enable it in non-production
669 environments.
670
671 If unsure, say N.
672
Dave Hansen0610c8a2013-07-01 13:04:43 -0700673config DEBUG_VM_RB
674 bool "Debug VM red-black trees"
675 depends on DEBUG_VM
676 help
Davidlohr Buesoa663dad2014-04-18 15:07:22 -0700677 Enable VM red-black tree debugging information and extra validations.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700678
679 If unsure, say N.
680
Kirill A. Shutemov95ad9752016-01-15 16:51:21 -0800681config DEBUG_VM_PGFLAGS
682 bool "Debug page-flags operations"
683 depends on DEBUG_VM
684 help
685 Enables extra validation on page flags operations.
686
687 If unsure, say N.
688
Laura Abbottfa5b6ec2017-01-10 13:35:40 -0800689config ARCH_HAS_DEBUG_VIRTUAL
690 bool
691
Dave Hansen0610c8a2013-07-01 13:04:43 -0700692config DEBUG_VIRTUAL
693 bool "Debug VM translations"
Laura Abbottfa5b6ec2017-01-10 13:35:40 -0800694 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
Dave Hansen0610c8a2013-07-01 13:04:43 -0700695 help
696 Enable some costly sanity checks in virtual to page code. This can
697 catch mistakes with virt_to_page() and friends.
698
699 If unsure, say N.
700
701config DEBUG_NOMMU_REGIONS
702 bool "Debug the global anon/private NOMMU mapping region tree"
703 depends on DEBUG_KERNEL && !MMU
704 help
705 This option causes the global tree of anonymous and private mapping
706 regions to be regularly checked for invalid topology.
707
708config DEBUG_MEMORY_INIT
709 bool "Debug memory initialisation" if EXPERT
710 default !EXPERT
711 help
712 Enable this for additional checks during memory initialisation.
713 The sanity checks verify aspects of the VM such as the memory model
714 and other information provided by the architecture. Verbose
715 information will be printed at KERN_DEBUG loglevel depending
716 on the mminit_loglevel= command-line option.
717
718 If unsure, say Y
719
720config MEMORY_NOTIFIER_ERROR_INJECT
721 tristate "Memory hotplug notifier error injection module"
722 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
723 help
724 This option provides the ability to inject artificial errors to
725 memory hotplug notifier chain callbacks. It is controlled through
726 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
727
728 If the notifier call chain should be failed with some events
729 notified, write the error code to "actions/<notifier event>/error".
730
731 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
732
733 # cd /sys/kernel/debug/notifier-error-inject/memory
734 # echo -12 > actions/MEM_GOING_OFFLINE/error
735 # echo offline > /sys/devices/system/memory/memoryXXX/state
736 bash: echo: write error: Cannot allocate memory
737
738 To compile this code as a module, choose M here: the module will
739 be called memory-notifier-error-inject.
740
741 If unsure, say N.
742
743config DEBUG_PER_CPU_MAPS
744 bool "Debug access to per_cpu maps"
745 depends on DEBUG_KERNEL
746 depends on SMP
747 help
748 Say Y to verify that the per_cpu map being accessed has
749 been set up. This adds a fair amount of code to kernel memory
750 and decreases performance.
751
752 Say N if unsure.
753
754config DEBUG_HIGHMEM
755 bool "Highmem debugging"
756 depends on DEBUG_KERNEL && HIGHMEM
757 help
Geert Uytterhoevenb1357c92014-04-14 18:55:50 +0200758 This option enables additional error checking for high memory
759 systems. Disable for production systems.
Dave Hansen0610c8a2013-07-01 13:04:43 -0700760
761config HAVE_DEBUG_STACKOVERFLOW
762 bool
763
764config DEBUG_STACKOVERFLOW
765 bool "Check for stack overflows"
766 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
767 ---help---
768 Say Y here if you want to check for overflows of kernel, IRQ
Borislav Petkovedb0ec02015-01-25 19:50:34 +0100769 and exception stacks (if your architecture uses them). This
Dave Hansen0610c8a2013-07-01 13:04:43 -0700770 option will show detailed messages if free stack space drops
771 below a certain limit.
772
773 These kinds of bugs usually occur when call-chains in the
774 kernel get too deep, especially when interrupts are
775 involved.
776
777 Use this in cases where you see apparently random memory
778 corruption, especially if it appears in 'struct thread_info'
779
780 If in doubt, say "N".
781
Andrey Ryabinin0b24bec2015-02-13 14:39:17 -0800782source "lib/Kconfig.kasan"
783
Dave Hansen0610c8a2013-07-01 13:04:43 -0700784endmenu # "Memory Debugging"
785
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786config DEBUG_SHIRQ
787 bool "Debug shared IRQ handlers"
Martin Schwidefsky0244ad02013-08-30 09:39:53 +0200788 depends on DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 help
790 Enable this to generate a spurious interrupt as soon as a shared
791 interrupt handler is registered, and just before one is deregistered.
792 Drivers ought to be able to handle interrupts coming in at those
793 points; some don't and need to be caught.
794
Changbin Duf43a2892019-12-06 17:03:54 -0800795menu "Debug Oops, Lockups and Hangs"
796
797config PANIC_ON_OOPS
798 bool "Panic on Oops"
799 help
800 Say Y here to enable the kernel to panic when it oopses. This
801 has the same effect as setting oops=panic on the kernel command
802 line.
803
804 This feature is useful to ensure that the kernel does not do
805 anything erroneous after an oops which could result in data
806 corruption or other issues.
807
808 Say N if unsure.
809
810config PANIC_ON_OOPS_VALUE
811 int
812 range 0 1
813 default 0 if !PANIC_ON_OOPS
814 default 1 if PANIC_ON_OOPS
815
816config PANIC_TIMEOUT
817 int "panic timeout"
818 default 0
819 help
820 Set the timeout value (in seconds) until a reboot occurs when the
821 the kernel panics. If n = 0, then we wait forever. A timeout
822 value n > 0 will wait n seconds before rebooting, while a timeout
823 value n < 0 will reboot immediately.
Dave Hansen92aef8fb2013-07-01 13:04:50 -0700824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825config LOCKUP_DETECTOR
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700826 bool
827
828config SOFTLOCKUP_DETECTOR
829 bool "Detect Soft Lockups"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 depends on DEBUG_KERNEL && !S390
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700831 select LOCKUP_DETECTOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 help
833 Say Y here to enable the kernel to act as a watchdog to detect
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700834 soft lockups.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835
836 Softlockups are bugs that cause the kernel to loop in kernel
837 mode for more than 20 seconds, without giving other tasks a
838 chance to run. The current stack trace is displayed upon
839 detection and the system will stay locked up.
840
Randy Dunlap5f00ae02018-04-10 16:32:51 -0700841config BOOTPARAM_SOFTLOCKUP_PANIC
842 bool "Panic (Reboot) On Soft Lockups"
843 depends on SOFTLOCKUP_DETECTOR
844 help
845 Say Y here to enable the kernel to panic on "soft lockups",
846 which are bugs that cause the kernel to loop in kernel
847 mode for more than 20 seconds (configurable using the watchdog_thresh
848 sysctl), without giving other tasks a chance to run.
849
850 The panic can be used in combination with panic_timeout,
851 to cause the system to reboot automatically after a
852 lockup has been detected. This feature is useful for
853 high-availability systems that have uptime guarantees and
854 where a lockup must be resolved ASAP.
855
856 Say N if unsure.
857
858config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
859 int
860 depends on SOFTLOCKUP_DETECTOR
861 range 0 1
862 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
863 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
864
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700865config HARDLOCKUP_DETECTOR_PERF
866 bool
867 select SOFTLOCKUP_DETECTOR
868
869#
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200870# Enables a timestamp based low pass filter to compensate for perf based
871# hard lockup detection which runs too fast due to turbo modes.
872#
873config HARDLOCKUP_CHECK_TIMESTAMP
874 bool
875
876#
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700877# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
878# lockup detector rather than the perf based detector.
879#
880config HARDLOCKUP_DETECTOR
881 bool "Detect Hard Lockups"
882 depends on DEBUG_KERNEL && !S390
883 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
884 select LOCKUP_DETECTOR
885 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
886 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
887 help
888 Say Y here to enable the kernel to act as a watchdog to detect
889 hard lockups.
890
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 Hardlockups are bugs that cause the CPU to loop in kernel mode
892 for more than 10 seconds, without letting other interrupts have a
893 chance to run. The current stack trace is displayed upon detection
894 and the system will stay locked up.
895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896config BOOTPARAM_HARDLOCKUP_PANIC
897 bool "Panic (Reboot) On Hard Lockups"
898 depends on HARDLOCKUP_DETECTOR
899 help
900 Say Y here to enable the kernel to panic on "hard lockups",
901 which are bugs that cause the kernel to loop in kernel
902 mode with interrupts disabled for more than 10 seconds (configurable
903 using the watchdog_thresh sysctl).
904
905 Say N if unsure.
906
907config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
908 int
909 depends on HARDLOCKUP_DETECTOR
910 range 0 1
911 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
912 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914config DETECT_HUNG_TASK
915 bool "Detect Hung Tasks"
916 depends on DEBUG_KERNEL
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700917 default SOFTLOCKUP_DETECTOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 help
919 Say Y here to enable the kernel to detect "hung tasks",
920 which are bugs that cause the task to be stuck in
Vivien Didelot96b03ab2016-09-22 16:55:13 -0400921 uninterruptible "D" state indefinitely.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922
923 When a hung task is detected, the kernel will print the
924 current stack trace (which you should report), but the
925 task will stay in uninterruptible state. If lockdep is
926 enabled then all held locks will also be reported. This
927 feature has negligible overhead.
Al Viro871751e2006-03-25 03:06:39 -0800928
929config DEFAULT_HUNG_TASK_TIMEOUT
930 int "Default timeout for hung task detection (in seconds)"
931 depends on DETECT_HUNG_TASK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 default 120
933 help
Ingo Molnar8637c092006-07-03 00:24:38 -0700934 This option controls the default timeout (in seconds) used
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 to determine when a task has become non-responsive and should
936 be considered hung.
937
938 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
939 sysctl or by writing a value to
940 /proc/sys/kernel/hung_task_timeout_secs.
941
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700942 A timeout of 0 disables the check. The default is two minutes.
943 Keeping the default should be fine in most cases.
Ingo Molnare7eebaf2006-06-27 02:54:55 -0700944
945config BOOTPARAM_HUNG_TASK_PANIC
946 bool "Panic (Reboot) On Hung Tasks"
947 depends on DETECT_HUNG_TASK
948 help
949 Say Y here to enable the kernel to panic on "hung tasks",
950 which are bugs that cause the kernel to leave a task stuck
951 in uninterruptible "D" state.
952
953 The panic can be used in combination with panic_timeout,
Thomas Gleixner61a87122006-06-27 02:54:56 -0700954 to cause the system to reboot automatically after a
955 hung task has been detected. This feature is useful for
Roman Zippela1583d32006-06-27 02:55:00 -0700956 high-availability systems that have uptime guarantees and
Thomas Gleixner61a87122006-06-27 02:54:56 -0700957 where a hung tasks must be resolved ASAP.
958
959 Say N if unsure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960
Hugh Dickins048c8bc2006-11-01 05:44:54 +1100961config BOOTPARAM_HUNG_TASK_PANIC_VALUE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 int
963 depends on DETECT_HUNG_TASK
964 range 0 1
965 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
966 default 1 if BOOTPARAM_HUNG_TASK_PANIC
967
Tejun Heo82607adc2015-12-08 11:28:04 -0500968config WQ_WATCHDOG
969 bool "Detect Workqueue Stalls"
970 depends on DEBUG_KERNEL
971 help
972 Say Y here to enable stall detection on workqueues. If a
973 worker pool doesn't make forward progress on a pending work
974 item for over a given amount of time, 30s by default, a
975 warning message is printed along with dump of workqueue
976 state. This can be configured through kernel parameter
977 "workqueue.watchdog_thresh" and its sysfs counterpart.
978
Konstantin Khlebnikov30428ef2020-04-06 20:09:47 -0700979config TEST_LOCKUP
980 tristate "Test module to generate lockups"
981 help
982 This builds the "test_lockup" module that helps to make sure
983 that watchdogs and lockup detectors are working properly.
984
985 Depending on module parameters it could emulate soft or hard
986 lockup, "hung task", or locking arbitrary lock for a long time.
987 Also it could generate series of lockups with cooling-down periods.
988
989 If unsure, say N.
990
Dave Hansen92aef8fb2013-07-01 13:04:50 -0700991endmenu # "Debug lockups and hangs"
992
Changbin Duebebdd02019-12-06 17:04:00 -0800993menu "Scheduler Debugging"
Jason Baron5800dc32013-11-25 23:23:04 +0000994
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995config SCHED_DEBUG
996 bool "Collect scheduler debugging info"
997 depends on DEBUG_KERNEL && PROC_FS
998 default y
999 help
1000 If you say Y here, the /proc/sched_debug file will be provided
1001 that can help debug the scheduler. The runtime overhead of this
1002 option is minimal.
1003
Naveen N. Raof6db8342015-06-25 23:53:37 +05301004config SCHED_INFO
1005 bool
1006 default n
1007
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008config SCHEDSTATS
1009 bool "Collect scheduler statistics"
1010 depends on DEBUG_KERNEL && PROC_FS
Naveen N. Raof6db8342015-06-25 23:53:37 +05301011 select SCHED_INFO
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 help
1013 If you say Y here, additional code will be inserted into the
1014 scheduler and related routines to collect statistics about
1015 scheduler behavior and provide them in /proc/schedstat. These
1016 stats may be useful for both tuning and debugging the scheduler
1017 If you aren't debugging the scheduler or trying to tune a specific
1018 application, you can say N to avoid the very slight overhead
1019 this adds.
1020
Changbin Duebebdd02019-12-06 17:04:00 -08001021endmenu
Aaron Tomlin0d9e2632014-09-12 14:16:19 +01001022
John Stultz3c17ad12015-03-11 21:16:32 -07001023config DEBUG_TIMEKEEPING
1024 bool "Enable extra timekeeping sanity checking"
1025 help
1026 This option will enable additional timekeeping sanity checks
1027 which may be helpful when diagnosing issues where timekeeping
1028 problems are suspected.
1029
1030 This may include checks in the timekeeping hotpaths, so this
1031 option may have a (very small) performance impact to some
1032 workloads.
1033
1034 If unsure, say N.
1035
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036config DEBUG_PREEMPT
1037 bool "Debug preemptible kernel"
Sebastian Andrzej Siewior9f472862019-10-15 21:18:19 +02001038 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 default y
1040 help
1041 If you say Y here then the kernel will use a debug variant of the
1042 commonly used smp_processor_id() function and will print warnings
1043 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1044 will detect preemption count underflows.
1045
Dave Hansen9eade162013-07-01 13:04:47 -07001046menu "Lock Debugging (spinlocks, mutexes, etc...)"
1047
Waiman Longf07cbeb2018-03-30 17:27:59 -04001048config LOCK_DEBUGGING_SUPPORT
1049 bool
1050 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1051 default y
1052
Waiman Long19193bc2018-03-30 17:28:00 -04001053config PROVE_LOCKING
1054 bool "Lock debugging: prove locking correctness"
1055 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1056 select LOCKDEP
1057 select DEBUG_SPINLOCK
1058 select DEBUG_MUTEXES
1059 select DEBUG_RT_MUTEXES if RT_MUTEXES
Waiman Longc71fd892019-05-20 16:59:00 -04001060 select DEBUG_RWSEMS
Waiman Long19193bc2018-03-30 17:28:00 -04001061 select DEBUG_WW_MUTEX_SLOWPATH
1062 select DEBUG_LOCK_ALLOC
1063 select TRACE_IRQFLAGS
1064 default n
1065 help
1066 This feature enables the kernel to prove that all locking
1067 that occurs in the kernel runtime is mathematically
1068 correct: that under no circumstance could an arbitrary (and
1069 not yet triggered) combination of observed locking
1070 sequences (on an arbitrary number of CPUs, running an
1071 arbitrary number of tasks and interrupt contexts) cause a
1072 deadlock.
1073
1074 In short, this feature enables the kernel to report locking
1075 related deadlocks before they actually occur.
1076
1077 The proof does not depend on how hard and complex a
1078 deadlock scenario would be to trigger: how many
1079 participant CPUs, tasks and irq-contexts would be needed
1080 for it to trigger. The proof also does not depend on
1081 timing: if a race and a resulting deadlock is possible
1082 theoretically (no matter how unlikely the race scenario
1083 is), it will be proven so and will immediately be
1084 reported by the kernel (once the event is observed that
1085 makes the deadlock theoretically possible).
1086
1087 If a deadlock is impossible (i.e. the locking rules, as
1088 observed by the kernel, are mathematically correct), the
1089 kernel reports nothing.
1090
1091 NOTE: this feature can also be enabled for rwlocks, mutexes
1092 and rwsems - in which case all dependencies between these
1093 different locking variants are observed and mapped too, and
1094 the proof of observed correctness is also maintained for an
1095 arbitrary combination of these separate locking variants.
1096
Mauro Carvalho Chehab387b1462019-04-10 08:32:41 -03001097 For more details, see Documentation/locking/lockdep-design.rst.
Waiman Long19193bc2018-03-30 17:28:00 -04001098
Peter Zijlstrade8f5e42020-03-21 12:26:01 +01001099config PROVE_RAW_LOCK_NESTING
1100 bool "Enable raw_spinlock - spinlock nesting checks"
1101 depends on PROVE_LOCKING
1102 default n
1103 help
1104 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1105 that the lock nesting rules for PREEMPT_RT enabled kernels are
1106 not violated.
1107
1108 NOTE: There are known nesting problems. So if you enable this
1109 option expect lockdep splats until these problems have been fully
1110 addressed which is work in progress. This config switch allows to
1111 identify and analyze these problems. It will be removed and the
1112 check permanentely enabled once the main issues have been fixed.
1113
1114 If unsure, select N.
1115
Waiman Long19193bc2018-03-30 17:28:00 -04001116config LOCK_STAT
1117 bool "Lock usage statistics"
1118 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1119 select LOCKDEP
1120 select DEBUG_SPINLOCK
1121 select DEBUG_MUTEXES
1122 select DEBUG_RT_MUTEXES if RT_MUTEXES
1123 select DEBUG_LOCK_ALLOC
1124 default n
1125 help
1126 This feature enables tracking lock contention points
1127
Mauro Carvalho Chehab387b1462019-04-10 08:32:41 -03001128 For more details, see Documentation/locking/lockstat.rst
Waiman Long19193bc2018-03-30 17:28:00 -04001129
1130 This also enables lock events required by "perf lock",
1131 subcommand of perf.
1132 If you want to use "perf lock", you also need to turn on
1133 CONFIG_EVENT_TRACING.
1134
1135 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1136 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1137
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138config DEBUG_RT_MUTEXES
1139 bool "RT Mutex debugging, deadlock detection"
1140 depends on DEBUG_KERNEL && RT_MUTEXES
1141 help
1142 This allows rt mutex semantics violations and rt mutex related
1143 deadlocks (lockups) to be detected and reported automatically.
1144
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145config DEBUG_SPINLOCK
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001146 bool "Spinlock and rw-lock debugging: basic checks"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 depends on DEBUG_KERNEL
Raghavendra K Te335e3e2012-03-22 15:25:08 +05301148 select UNINLINE_SPIN_UNLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 help
1150 Say Y here and build SMP to catch missing spinlock initialization
1151 and certain other kinds of spinlock errors commonly made. This is
1152 best used in conjunction with the NMI watchdog so that spinlock
1153 deadlocks are also debuggable.
1154
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001155config DEBUG_MUTEXES
1156 bool "Mutex debugging: basic checks"
1157 depends on DEBUG_KERNEL
1158 help
1159 This feature allows mutex semantics violations to be detected and
1160 reported.
1161
Daniel Vetter23010022013-06-20 13:31:17 +02001162config DEBUG_WW_MUTEX_SLOWPATH
1163 bool "Wait/wound mutex debugging: Slowpath testing"
Waiman Longf07cbeb2018-03-30 17:27:59 -04001164 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Daniel Vetter23010022013-06-20 13:31:17 +02001165 select DEBUG_LOCK_ALLOC
1166 select DEBUG_SPINLOCK
1167 select DEBUG_MUTEXES
1168 help
1169 This feature enables slowpath testing for w/w mutex users by
1170 injecting additional -EDEADLK wound/backoff cases. Together with
1171 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1172 will test all possible w/w mutex interface abuse with the
1173 exception of simply not acquiring all the required locks.
Rob Clark4d692372014-08-27 11:19:26 -04001174 Note that this feature can introduce significant overhead, so
1175 it really should not be enabled in a production or distro kernel,
1176 even a debug kernel. If you are a driver writer, enable it. If
1177 you are a distro, do not.
Daniel Vetter23010022013-06-20 13:31:17 +02001178
Waiman Long5149cba2018-03-30 17:27:58 -04001179config DEBUG_RWSEMS
1180 bool "RW Semaphore debugging: basic checks"
Waiman Longc71fd892019-05-20 16:59:00 -04001181 depends on DEBUG_KERNEL
Waiman Long5149cba2018-03-30 17:27:58 -04001182 help
Waiman Longc71fd892019-05-20 16:59:00 -04001183 This debugging feature allows mismatched rw semaphore locks
1184 and unlocks to be detected and reported.
Waiman Long5149cba2018-03-30 17:27:58 -04001185
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001186config DEBUG_LOCK_ALLOC
1187 bool "Lock debugging: detect incorrect freeing of live locks"
Waiman Longf07cbeb2018-03-30 17:27:59 -04001188 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001189 select DEBUG_SPINLOCK
1190 select DEBUG_MUTEXES
Peter Zijlstraf5694782016-09-19 12:15:37 +02001191 select DEBUG_RT_MUTEXES if RT_MUTEXES
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001192 select LOCKDEP
1193 help
1194 This feature will check whether any held lock (spinlock, rwlock,
1195 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1196 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1197 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1198 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1199 held during task exit.
1200
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001201config LOCKDEP
1202 bool
Waiman Longf07cbeb2018-03-30 17:27:59 -04001203 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001204 select STACKTRACE
Stefan Agnerf9b58e82018-09-30 23:02:33 +01001205 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001206 select KALLSYMS
1207 select KALLSYMS_ALL
1208
Daniel Jordan395102d2017-04-10 11:50:52 -04001209config LOCKDEP_SMALL
1210 bool
1211
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001212config DEBUG_LOCKDEP
1213 bool "Lock dependency engine debugging"
Adrian Bunk517e7aa2006-07-14 00:24:32 -07001214 depends on DEBUG_KERNEL && LOCKDEP
Ingo Molnar4d9f34a2006-07-03 00:24:55 -07001215 help
1216 If you say Y here, the lock dependency engine will do
1217 additional runtime checks to debug itself, at the price
1218 of more runtime overhead.
1219
Frederic Weisbeckerd902db12011-06-08 19:31:56 +02001220config DEBUG_ATOMIC_SLEEP
1221 bool "Sleep inside atomic section checking"
Frederic Weisbeckere8f7c702011-06-08 01:51:02 +02001222 select PREEMPT_COUNT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 depends on DEBUG_KERNEL
Christoph Hellwig87a4c372018-07-31 13:39:32 +02001224 depends on !ARCH_NO_PREEMPT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 help
1226 If you say Y here, various routines which may sleep will become very
Frederic Weisbeckerd902db12011-06-08 19:31:56 +02001227 noisy if they are called inside atomic sections: when a spinlock is
1228 held, inside an rcu read side critical section, inside preempt disabled
1229 sections, inside an interrupt, etc...
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230
Ingo Molnarcae2ed92006-07-03 00:24:48 -07001231config DEBUG_LOCKING_API_SELFTESTS
1232 bool "Locking API boot-time self-tests"
1233 depends on DEBUG_KERNEL
1234 help
1235 Say Y here if you want the kernel to run a short self-test during
1236 bootup. The self-test checks whether common types of locking bugs
1237 are detected by debugging mechanisms or not. (if you disable
1238 lock debugging then those bugs wont be detected of course.)
1239 The following locking APIs are covered: spinlocks, rwlocks,
1240 mutexes and rwsems.
1241
Paul E. McKenney0af3fe12014-02-04 15:51:41 -08001242config LOCK_TORTURE_TEST
1243 tristate "torture tests for locking"
1244 depends on DEBUG_KERNEL
1245 select TORTURE_TEST
Paul E. McKenney0af3fe12014-02-04 15:51:41 -08001246 help
1247 This option provides a kernel module that runs torture tests
1248 on kernel locking primitives. The kernel module may be built
1249 after the fact on the running kernel to be tested, if desired.
1250
1251 Say Y here if you want kernel locking-primitive torture tests
1252 to be built into the kernel.
1253 Say M if you want these torture tests to build as a module.
1254 Say N if you are unsure.
1255
Chris Wilsonf2a5fec2016-12-01 11:47:06 +00001256config WW_MUTEX_SELFTEST
1257 tristate "Wait/wound mutex selftests"
1258 help
1259 This option provides a kernel module that runs tests on the
1260 on the struct ww_mutex locking API.
1261
1262 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1263 with this test harness.
1264
1265 Say M if you want these self tests to build as a module.
1266 Say N if you are unsure.
1267
Dave Hansen9eade162013-07-01 13:04:47 -07001268endmenu # lock debugging
1269
1270config TRACE_IRQFLAGS
1271 bool
1272 help
1273 Enables hooks to interrupt enabling and disabling for
1274 either tracing or lock debugging.
1275
Ingo Molnar8637c092006-07-03 00:24:38 -07001276config STACKTRACE
Dave Jones0c38e1f2014-08-29 15:18:35 -07001277 bool "Stack backtrace support"
Ingo Molnar8637c092006-07-03 00:24:38 -07001278 depends on STACKTRACE_SUPPORT
Dave Jones0c38e1f2014-08-29 15:18:35 -07001279 help
1280 This option causes the kernel to create a /proc/pid/stack for
1281 every process, showing its current stack trace.
1282 It is also used by various kernel debugging features that require
1283 stack trace generation.
Ingo Molnar8637c092006-07-03 00:24:38 -07001284
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001285config WARN_ALL_UNSEEDED_RANDOM
1286 bool "Warn for all uses of unseeded randomness"
1287 default n
Jason A. Donenfeldd06bfd12017-06-07 23:06:55 -04001288 help
1289 Some parts of the kernel contain bugs relating to their use of
1290 cryptographically secure random numbers before it's actually possible
1291 to generate those numbers securely. This setting ensures that these
1292 flaws don't go unnoticed, by enabling a message, should this ever
1293 occur. This will allow people with obscure setups to know when things
1294 are going wrong, so that they might contact developers about fixing
1295 it.
1296
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001297 Unfortunately, on some models of some architectures getting
1298 a fully seeded CRNG is extremely difficult, and so this can
1299 result in dmesg getting spammed for a surprisingly long
1300 time. This is really bad from a security perspective, and
1301 so architecture maintainers really need to do what they can
1302 to get the CRNG seeded sooner after the system is booted.
Thibaut Sautereau4c5d1142018-09-04 15:46:23 -07001303 However, since users cannot do anything actionable to
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001304 address this, by default the kernel will issue only a single
1305 warning for the first use of unseeded randomness.
1306
1307 Say Y here if you want to receive warnings for all uses of
1308 unseeded randomness. This will be of use primarily for
Thibaut Sautereau4c5d1142018-09-04 15:46:23 -07001309 those developers interested in improving the security of
Theodore Ts'oeecabf52017-06-08 04:16:59 -04001310 Linux kernels running on their architecture (or
1311 subarchitecture).
Jason A. Donenfeldd06bfd12017-06-07 23:06:55 -04001312
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313config DEBUG_KOBJECT
1314 bool "kobject debugging"
1315 depends on DEBUG_KERNEL
1316 help
1317 If you say Y here, some extra kobject debugging messages will be sent
Mike Rapoportaca52c32018-10-30 15:07:44 -07001318 to the syslog.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319
Russell Kingc817a672013-06-27 15:06:14 +01001320config DEBUG_KOBJECT_RELEASE
1321 bool "kobject release debugging"
Linus Torvalds2a999aa2013-10-29 08:33:36 -07001322 depends on DEBUG_OBJECTS_TIMERS
Russell Kingc817a672013-06-27 15:06:14 +01001323 help
1324 kobjects are reference counted objects. This means that their
1325 last reference count put is not predictable, and the kobject can
1326 live on past the point at which a driver decides to drop it's
1327 initial reference to the kobject gained on allocation. An
1328 example of this would be a struct device which has just been
1329 unregistered.
1330
1331 However, some buggy drivers assume that after such an operation,
1332 the memory backing the kobject can be immediately freed. This
1333 goes completely against the principles of a refcounted object.
1334
1335 If you say Y here, the kernel will delay the release of kobjects
1336 on the last reference count to improve the visibility of this
1337 kind of kobject release bug.
1338
Catalin Marinas9b2a60c2012-10-08 16:28:13 -07001339config HAVE_DEBUG_BUGVERBOSE
1340 bool
1341
Changbin Du3be5cbc2019-12-06 17:03:48 -08001342menu "Debug kernel data structures"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343
Dave Jones199a9af2006-09-29 01:59:00 -07001344config DEBUG_LIST
1345 bool "Debug linked list manipulation"
Arnd Bergmann4520bcb2016-08-26 17:42:00 +02001346 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
Dave Jones199a9af2006-09-29 01:59:00 -07001347 help
1348 Enable this to turn on extended checks in the linked-list
1349 walking routines.
1350
1351 If unsure, say N.
1352
Davidlohr Bueso8e18fae2019-05-14 15:42:46 -07001353config DEBUG_PLIST
Dan Streetmanb8cfff62014-06-04 16:11:54 -07001354 bool "Debug priority linked list manipulation"
1355 depends on DEBUG_KERNEL
1356 help
1357 Enable this to turn on extended checks in the priority-ordered
1358 linked-list (plist) walking routines. This checks the entire
1359 list multiple times during each manipulation.
1360
1361 If unsure, say N.
1362
Jens Axboed6ec0842007-10-22 20:01:06 +02001363config DEBUG_SG
1364 bool "Debug SG table operations"
1365 depends on DEBUG_KERNEL
1366 help
1367 Enable this to turn on checks on scatter-gather tables. This can
1368 help find problems with drivers that do not properly initialize
1369 their sg tables.
1370
1371 If unsure, say N.
1372
Arjan van de Ven1b2439d2008-08-15 15:29:38 -07001373config DEBUG_NOTIFIERS
1374 bool "Debug notifier call chains"
1375 depends on DEBUG_KERNEL
1376 help
1377 Enable this to turn on sanity checking for notifier call chains.
1378 This is most useful for kernel developers to make sure that
1379 modules properly unregister themselves from notifier chains.
1380 This is a relatively cheap check but if you care about maximum
1381 performance, say N.
1382
Changbin Du3be5cbc2019-12-06 17:03:48 -08001383config BUG_ON_DATA_CORRUPTION
1384 bool "Trigger a BUG when data corruption is detected"
1385 select DEBUG_LIST
1386 help
1387 Select this option if the kernel should BUG when it encounters
1388 data corruption in kernel memory structures when they get checked
1389 for validity.
1390
1391 If unsure, say N.
1392
1393endmenu
1394
David Howellse0e81732009-09-02 09:13:40 +01001395config DEBUG_CREDENTIALS
1396 bool "Debug credential management"
1397 depends on DEBUG_KERNEL
1398 help
1399 Enable this to turn on some debug checking for credential
1400 management. The additional code keeps track of the number of
1401 pointers from task_structs to any given cred struct, and checks to
1402 see that this number never exceeds the usage count of the cred
1403 struct.
1404
1405 Furthermore, if SELinux is enabled, this also checks that the
1406 security pointer in the cred struct is never seen to be invalid.
1407
1408 If unsure, say N.
1409
Paul E. McKenney43a0a2a2017-05-17 09:19:44 -07001410source "kernel/rcu/Kconfig.debug"
Dave Hansen2f03e3c2013-01-07 08:19:23 -08001411
Tejun Heof303fccb2016-02-09 17:59:38 -05001412config DEBUG_WQ_FORCE_RR_CPU
1413 bool "Force round-robin CPU selection for unbound work items"
1414 depends on DEBUG_KERNEL
1415 default n
1416 help
1417 Workqueue used to implicitly guarantee that work items queued
1418 without explicit CPU specified are put on the local CPU. This
1419 guarantee is no longer true and while local CPU is still
1420 preferred work items may be put on foreign CPUs. Kernel
1421 parameter "workqueue.debug_force_rr_cpu" is added to force
1422 round-robin CPU selection to flush out usages which depend on the
1423 now broken guarantee. This config option enables the debug
1424 feature by default. When enabled, memory and cache locality will
1425 be impacted.
1426
Tejun Heo870d6652008-08-25 19:47:25 +09001427config DEBUG_BLOCK_EXT_DEVT
Krzysztof Kozlowski68d4b3d2019-12-06 17:04:08 -08001428 bool "Force extended block device numbers and spread them"
Tejun Heo870d6652008-08-25 19:47:25 +09001429 depends on DEBUG_KERNEL
1430 depends on BLOCK
Jens Axboe759f8ca2008-08-29 09:06:29 +02001431 default n
Tejun Heo870d6652008-08-25 19:47:25 +09001432 help
Tejun Heo0e11e342008-10-13 10:46:01 +02001433 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1434 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1435 YOU ARE DOING. Distros, please enable this and fix whatever
1436 is broken.
1437
Tejun Heo870d6652008-08-25 19:47:25 +09001438 Conventionally, block device numbers are allocated from
1439 predetermined contiguous area. However, extended block area
1440 may introduce non-contiguous block device numbers. This
1441 option forces most block device numbers to be allocated from
1442 the extended space and spreads them to discover kernel or
1443 userland code paths which assume predetermined contiguous
1444 device number allocation.
1445
Tejun Heo55dc7db2008-09-01 13:44:35 +02001446 Note that turning on this debug option shuffles all the
1447 device numbers for all IDE and SCSI devices including libata
1448 ones, so root partition specified using device number
1449 directly (via rdev or root=MAJ:MIN) won't work anymore.
1450 Textual device names (root=/dev/sdXn) will continue to work.
1451
Tejun Heo870d6652008-08-25 19:47:25 +09001452 Say N if you are unsure.
1453
Thomas Gleixner757c9892016-02-26 18:43:32 +00001454config CPU_HOTPLUG_STATE_CONTROL
1455 bool "Enable CPU hotplug state control"
1456 depends on DEBUG_KERNEL
1457 depends on HOTPLUG_CPU
1458 default n
1459 help
1460 Allows to write steps between "offline" and "online" to the CPUs
1461 sysfs target file so states can be stepped granular. This is a debug
1462 option for now as the hotplug machinery cannot be stopped and
1463 restarted at arbitrary points yet.
1464
1465 Say N if your are unsure.
1466
Changbin Du09a74952019-12-06 17:03:51 -08001467config LATENCYTOP
1468 bool "Latency measuring infrastructure"
1469 depends on DEBUG_KERNEL
1470 depends on STACKTRACE_SUPPORT
1471 depends on PROC_FS
1472 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1473 select KALLSYMS
1474 select KALLSYMS_ALL
1475 select STACKTRACE
1476 select SCHEDSTATS
1477 select SCHED_DEBUG
1478 help
1479 Enable this option if you want to use the LatencyTOP tool
1480 to find out which userspace is blocking on what kernel operations.
1481
1482source "kernel/trace/Kconfig"
1483
1484config PROVIDE_OHCI1394_DMA_INIT
1485 bool "Remote debugging over FireWire early on boot"
1486 depends on PCI && X86
1487 help
1488 If you want to debug problems which hang or crash the kernel early
1489 on boot and the crashing machine has a FireWire port, you can use
1490 this feature to remotely access the memory of the crashed machine
1491 over FireWire. This employs remote DMA as part of the OHCI1394
1492 specification which is now the standard for FireWire controllers.
1493
1494 With remote DMA, you can monitor the printk buffer remotely using
1495 firescope and access all memory below 4GB using fireproxy from gdb.
1496 Even controlling a kernel debugger is possible using remote DMA.
1497
1498 Usage:
1499
1500 If ohci1394_dma=early is used as boot parameter, it will initialize
1501 all OHCI1394 controllers which are found in the PCI config space.
1502
1503 As all changes to the FireWire bus such as enabling and disabling
1504 devices cause a bus reset and thereby disable remote DMA for all
1505 devices, be sure to have the cable plugged and FireWire enabled on
1506 the debugging host before booting the debug target for debugging.
1507
1508 This code (~1k) is freed after boot. By then, the firewire stack
1509 in charge of the OHCI-1394 controllers should be used instead.
1510
1511 See Documentation/debugging-via-ohci1394.txt for more information.
1512
Changbin Du045f6d72019-12-17 20:51:56 -08001513source "samples/Kconfig"
1514
1515config ARCH_HAS_DEVMEM_IS_ALLOWED
1516 bool
1517
1518config STRICT_DEVMEM
1519 bool "Filter access to /dev/mem"
1520 depends on MMU && DEVMEM
1521 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1522 default y if PPC || X86 || ARM64
1523 help
1524 If this option is disabled, you allow userspace (root) access to all
1525 of memory, including kernel and userspace memory. Accidental
1526 access to this is obviously disastrous, but specific access can
1527 be used by people debugging the kernel. Note that with PAT support
1528 enabled, even in this case there are restrictions on /dev/mem
1529 use due to the cache aliasing requirements.
1530
1531 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1532 file only allows userspace access to PCI space and the BIOS code and
1533 data regions. This is sufficient for dosemu and X and all common
1534 users of /dev/mem.
1535
1536 If in doubt, say Y.
1537
1538config IO_STRICT_DEVMEM
1539 bool "Filter I/O access to /dev/mem"
1540 depends on STRICT_DEVMEM
1541 help
1542 If this option is disabled, you allow userspace (root) access to all
1543 io-memory regardless of whether a driver is actively using that
1544 range. Accidental access to this is obviously disastrous, but
1545 specific access can be used by people debugging kernel drivers.
1546
1547 If this option is switched on, the /dev/mem file only allows
1548 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1549 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1550 if the driver using a given range cannot be disabled.
1551
1552 If in doubt, say Y.
1553
1554menu "$(SRCARCH) Debugging"
1555
1556source "arch/$(SRCARCH)/Kconfig.debug"
1557
1558endmenu
1559
1560menu "Kernel Testing and Coverage"
1561
Changbin Du09a74952019-12-06 17:03:51 -08001562source "lib/kunit/Kconfig"
1563
Akinobu Mita8d438282012-07-30 14:43:02 -07001564config NOTIFIER_ERROR_INJECTION
1565 tristate "Notifier error injection"
1566 depends on DEBUG_KERNEL
1567 select DEBUG_FS
1568 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001569 This option provides the ability to inject artificial errors to
Akinobu Mita8d438282012-07-30 14:43:02 -07001570 specified notifier chain callbacks. It is useful to test the error
1571 handling of notifier call chain failures.
1572
1573 Say N if unsure.
1574
Akinobu Mita048b9c32012-07-30 14:43:07 -07001575config PM_NOTIFIER_ERROR_INJECT
1576 tristate "PM notifier error injection module"
1577 depends on PM && NOTIFIER_ERROR_INJECTION
1578 default m if PM_DEBUG
1579 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001580 This option provides the ability to inject artificial errors to
Akinobu Mita048b9c32012-07-30 14:43:07 -07001581 PM notifier chain callbacks. It is controlled through debugfs
1582 interface /sys/kernel/debug/notifier-error-inject/pm
1583
1584 If the notifier call chain should be failed with some events
1585 notified, write the error code to "actions/<notifier event>/error".
1586
1587 Example: Inject PM suspend error (-12 = -ENOMEM)
1588
1589 # cd /sys/kernel/debug/notifier-error-inject/pm/
1590 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1591 # echo mem > /sys/power/state
1592 bash: echo: write error: Cannot allocate memory
1593
1594 To compile this code as a module, choose M here: the module will
1595 be called pm-notifier-error-inject.
1596
1597 If unsure, say N.
1598
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001599config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1600 tristate "OF reconfig notifier error injection module"
1601 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001602 help
Masanari Iidae41e85c2012-11-30 16:44:39 +09001603 This option provides the ability to inject artificial errors to
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001604 OF reconfig notifier chain callbacks. It is controlled
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001605 through debugfs interface under
Benjamin Herrenschmidtd526e852012-12-14 10:32:52 +11001606 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001607
1608 If the notifier call chain should be failed with some events
1609 notified, write the error code to "actions/<notifier event>/error".
1610
1611 To compile this code as a module, choose M here: the module will
Akinobu Mitae12a95f2013-04-30 15:28:49 -07001612 be called of-reconfig-notifier-error-inject.
Akinobu Mita08dfb4d2012-07-30 14:43:13 -07001613
1614 If unsure, say N.
1615
Nikolay Aleksandrov02fff962015-11-28 13:45:28 +01001616config NETDEV_NOTIFIER_ERROR_INJECT
1617 tristate "Netdev notifier error injection module"
1618 depends on NET && NOTIFIER_ERROR_INJECTION
1619 help
1620 This option provides the ability to inject artificial errors to
1621 netdevice notifier chain callbacks. It is controlled through debugfs
1622 interface /sys/kernel/debug/notifier-error-inject/netdev
1623
1624 If the notifier call chain should be failed with some events
1625 notified, write the error code to "actions/<notifier event>/error".
1626
1627 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1628
1629 # cd /sys/kernel/debug/notifier-error-inject/netdev
1630 # echo -22 > actions/NETDEV_CHANGEMTU/error
1631 # ip link set eth0 mtu 1024
1632 RTNETLINK answers: Invalid argument
1633
1634 To compile this code as a module, choose M here: the module will
1635 be called netdev-notifier-error-inject.
1636
1637 If unsure, say N.
1638
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001639config FUNCTION_ERROR_INJECTION
1640 def_bool y
1641 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1642
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001643config FAULT_INJECTION
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001644 bool "Fault-injection framework"
1645 depends on DEBUG_KERNEL
Akinobu Mita329409a2006-12-08 02:39:48 -08001646 help
1647 Provide fault-injection framework.
1648 For more details, see Documentation/fault-injection/.
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001649
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001650config FAILSLAB
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001651 bool "Fault-injection capability for kmalloc"
1652 depends on FAULT_INJECTION
Akinobu Mita773ff602008-12-23 19:37:01 +09001653 depends on SLAB || SLUB
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001654 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001655 Provide fault-injection capability for kmalloc.
Akinobu Mita8a8b6502006-12-08 02:39:44 -08001656
Akinobu Mita933e3122006-12-08 02:39:45 -08001657config FAIL_PAGE_ALLOC
Qiujun Huang29b46fa2020-04-06 20:12:49 -07001658 bool "Fault-injection capability for alloc_pages()"
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001659 depends on FAULT_INJECTION
Akinobu Mita933e3122006-12-08 02:39:45 -08001660 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001661 Provide fault-injection capability for alloc_pages().
Akinobu Mita933e3122006-12-08 02:39:45 -08001662
Akinobu Mitac17bb492006-12-08 02:39:46 -08001663config FAIL_MAKE_REQUEST
Dave Jones86327d12006-12-12 20:16:36 +01001664 bool "Fault-injection capability for disk IO"
Jens Axboe581d4e22008-09-14 05:56:33 -07001665 depends on FAULT_INJECTION && BLOCK
Akinobu Mitac17bb492006-12-08 02:39:46 -08001666 help
Andrew Morton1ab8509a2006-12-08 02:39:49 -08001667 Provide fault-injection capability for disk IO.
Akinobu Mitac17bb492006-12-08 02:39:46 -08001668
Jens Axboe581d4e22008-09-14 05:56:33 -07001669config FAIL_IO_TIMEOUT
Takuya Yoshikawaf4d01432010-07-21 16:05:53 +09001670 bool "Fault-injection capability for faking disk interrupts"
Jens Axboe581d4e22008-09-14 05:56:33 -07001671 depends on FAULT_INJECTION && BLOCK
1672 help
1673 Provide fault-injection capability on end IO handling. This
1674 will make the block layer "forget" an interrupt as configured,
1675 thus exercising the error handling.
1676
1677 Only works with drivers that use the generic timeout handling,
1678 for others it wont do anything.
1679
Davidlohr Buesoab51fba2015-06-29 23:26:02 -07001680config FAIL_FUTEX
1681 bool "Fault-injection capability for futexes"
1682 select DEBUG_FS
1683 depends on FAULT_INJECTION && FUTEX
1684 help
1685 Provide fault-injection capability for futexes.
1686
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001687config FAULT_INJECTION_DEBUG_FS
1688 bool "Debugfs entries for fault-injection capabilities"
1689 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1690 help
1691 Enable configuration of fault-injection capabilities via debugfs.
1692
Masami Hiramatsu4b1a29a2018-01-13 02:56:03 +09001693config FAIL_FUNCTION
1694 bool "Fault-injection capability for functions"
1695 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1696 help
1697 Provide function-based fault-injection capability.
1698 This will allow you to override a specific function with a return
1699 with given return value. As a result, function caller will see
1700 an error value and have to handle it. This is useful to test the
1701 error handling in various subsystems.
1702
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001703config FAIL_MMC_REQUEST
1704 bool "Fault-injection capability for MMC IO"
1705 depends on FAULT_INJECTION_DEBUG_FS && MMC
Akinobu Mita6ff1cb32006-12-08 02:39:43 -08001706 help
Mikulas Patockaf1b4bd02018-06-14 15:27:48 -07001707 Provide fault-injection capability for MMC IO.
1708 This will make the mmc core return data errors. This is
1709 useful to test the error handling in the mmc block device
1710 and to test how the mmc host driver handles retries from
1711 the block device.
Akinobu Mita1df49002007-02-20 13:57:56 -08001712
1713config FAULT_INJECTION_STACKTRACE_FILTER
1714 bool "stacktrace filter for fault-injection capabilities"
1715 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
Akinobu Mita6d690dc2007-05-12 10:36:53 -07001716 depends on !X86_64
Akinobu Mita1df49002007-02-20 13:57:56 -08001717 select STACKTRACE
Stefan Agnerf9b58e82018-09-30 23:02:33 +01001718 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
Akinobu Mita1df49002007-02-20 13:57:56 -08001719 help
1720 Provide stacktrace filter for fault-injection capabilities
Mathieu Desnoyers267c4022007-10-18 23:41:07 -07001721
Changbin Du09a74952019-12-06 17:03:51 -08001722config ARCH_HAS_KCOV
1723 bool
Arjan van de Ven97455122008-01-25 21:08:34 +01001724 help
Changbin Du09a74952019-12-06 17:03:51 -08001725 An architecture should select this when it can successfully
1726 build and run with CONFIG_KCOV. This typically requires
1727 disabling instrumentation for some early boot code.
Arjan van de Ven97455122008-01-25 21:08:34 +01001728
Changbin Du09a74952019-12-06 17:03:51 -08001729config CC_HAS_SANCOV_TRACE_PC
1730 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001731
Changbin Du09a74952019-12-06 17:03:51 -08001732
1733config KCOV
1734 bool "Code coverage for fuzzing"
1735 depends on ARCH_HAS_KCOV
1736 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1737 select DEBUG_FS
1738 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001739 help
Changbin Du09a74952019-12-06 17:03:51 -08001740 KCOV exposes kernel code coverage information in a form suitable
1741 for coverage-guided fuzzing (randomized testing).
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001742
Changbin Du09a74952019-12-06 17:03:51 -08001743 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1744 different machines and across reboots. If you need stable PC values,
1745 disable RANDOMIZE_BASE.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001746
Changbin Du09a74952019-12-06 17:03:51 -08001747 For more details, see Documentation/dev-tools/kcov.rst.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001748
Changbin Du09a74952019-12-06 17:03:51 -08001749config KCOV_ENABLE_COMPARISONS
1750 bool "Enable comparison operands collection by KCOV"
1751 depends on KCOV
1752 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1753 help
1754 KCOV also exposes operands of every comparison in the instrumented
1755 code along with operand sizes and PCs of the comparison instructions.
1756 These operands can be used by fuzzing engines to improve the quality
1757 of fuzzing coverage.
Randy Dunlapcc3fa842017-10-13 15:57:33 -07001758
Changbin Du09a74952019-12-06 17:03:51 -08001759config KCOV_INSTRUMENT_ALL
1760 bool "Instrument all code by default"
1761 depends on KCOV
1762 default y
1763 help
1764 If you are doing generic system call fuzzing (like e.g. syzkaller),
1765 then you will want to instrument the whole kernel and you should
1766 say y here. If you are doing more targeted fuzzing (like e.g.
1767 filesystem fuzzing with AFL) then you will want to enable coverage
1768 for more specific subsets of files, and should say n here.
Brendan Higgins84bc8092019-09-23 02:02:36 -07001769
Vincent Legolld3deafa2018-02-06 15:38:38 -08001770menuconfig RUNTIME_TESTING_MENU
1771 bool "Runtime Testing"
Anders Roxell908009e82018-02-21 14:46:05 -08001772 def_bool y
Vincent Legolld3deafa2018-02-06 15:38:38 -08001773
1774if RUNTIME_TESTING_MENU
Dave Hansen881c5142013-07-01 13:04:44 -07001775
1776config LKDTM
1777 tristate "Linux Kernel Dump Test Tool Module"
1778 depends on DEBUG_FS
Dave Hansen881c5142013-07-01 13:04:44 -07001779 help
1780 This module enables testing of the different dumping mechanisms by
1781 inducing system failures at predefined crash points.
1782 If you don't need it: say N
1783 Choose M here to compile this code as a module. The module will be
1784 called lkdtm.
1785
1786 Documentation on how to use the module can be found in
Mauro Carvalho Chehab10ffebb2019-06-12 14:52:44 -03001787 Documentation/fault-injection/provoke-crashes.rst
Dave Hansen881c5142013-07-01 13:04:44 -07001788
1789config TEST_LIST_SORT
Geert Uytterhoevene327fd72017-05-08 15:55:26 -07001790 tristate "Linked list sorting test"
1791 depends on DEBUG_KERNEL || m
Dave Hansen881c5142013-07-01 13:04:44 -07001792 help
1793 Enable this to turn on 'list_sort()' function test. This test is
Geert Uytterhoevene327fd72017-05-08 15:55:26 -07001794 executed only once during system boot (so affects only boot time),
1795 or at module load time.
Dave Hansen881c5142013-07-01 13:04:44 -07001796
1797 If unsure, say N.
1798
Ian Rogers6e246282020-02-13 23:51:29 -08001799config TEST_MIN_HEAP
1800 tristate "Min heap test"
1801 depends on DEBUG_KERNEL || m
1802 help
1803 Enable this to turn on min heap function tests. This test is
1804 executed only once during system boot (so affects only boot time),
1805 or at module load time.
1806
1807 If unsure, say N.
1808
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001809config TEST_SORT
Geert Uytterhoeven5c4e6792017-05-08 15:55:23 -07001810 tristate "Array-based sort test"
1811 depends on DEBUG_KERNEL || m
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001812 help
Geert Uytterhoeven5c4e6792017-05-08 15:55:23 -07001813 This option enables the self-test function of 'sort()' at boot,
1814 or at module load time.
Kostenzer Felixc5adae92017-02-24 15:01:07 -08001815
1816 If unsure, say N.
1817
Dave Hansen881c5142013-07-01 13:04:44 -07001818config KPROBES_SANITY_TEST
1819 bool "Kprobes sanity tests"
1820 depends on DEBUG_KERNEL
1821 depends on KPROBES
Dave Hansen881c5142013-07-01 13:04:44 -07001822 help
1823 This option provides for testing basic kprobes functionality on
Masami Hiramatsu5a6cf772018-06-20 01:05:07 +09001824 boot. Samples of kprobe and kretprobe are inserted and
Dave Hansen881c5142013-07-01 13:04:44 -07001825 verified for functionality.
1826
1827 Say N if you are unsure.
1828
1829config BACKTRACE_SELF_TEST
1830 tristate "Self test for the backtrace code"
1831 depends on DEBUG_KERNEL
Dave Hansen881c5142013-07-01 13:04:44 -07001832 help
1833 This option provides a kernel module that can be used to test
1834 the kernel stack backtrace code. This option is not useful
1835 for distributions or general kernels, but only for kernel
1836 developers working on architecture code.
1837
1838 Note that if you want to also test saved backtraces, you will
1839 have to enable STACKTRACE as well.
1840
1841 Say N if you are unsure.
1842
Michel Lespinasse910a7422012-10-08 16:30:39 -07001843config RBTREE_TEST
1844 tristate "Red-Black tree test"
Cody P Schafer7c993e12013-09-11 14:25:19 -07001845 depends on DEBUG_KERNEL
Michel Lespinasse910a7422012-10-08 16:30:39 -07001846 help
1847 A benchmark measuring the performance of the rbtree library.
1848 Also includes rbtree invariant checks.
1849
Ferdinand Blomqvist4b4f3ac2019-06-20 17:10:33 +03001850config REED_SOLOMON_TEST
1851 tristate "Reed-Solomon library test"
1852 depends on DEBUG_KERNEL || m
1853 select REED_SOLOMON
1854 select REED_SOLOMON_ENC16
1855 select REED_SOLOMON_DEC16
1856 help
1857 This option enables the self-test function of rslib at boot,
1858 or at module load time.
1859
1860 If unsure, say N.
1861
Michel Lespinassefff3fd82012-10-08 16:31:23 -07001862config INTERVAL_TREE_TEST
1863 tristate "Interval tree test"
Davidlohr Bueso0f789b62017-07-10 15:51:43 -07001864 depends on DEBUG_KERNEL
Chris Wilsona88cc102014-03-17 12:21:54 +00001865 select INTERVAL_TREE
Michel Lespinassefff3fd82012-10-08 16:31:23 -07001866 help
1867 A benchmark measuring the performance of the interval tree library
1868
Greg Thelen623fd802013-11-12 15:08:34 -08001869config PERCPU_TEST
1870 tristate "Per cpu operations test"
1871 depends on m && DEBUG_KERNEL
1872 help
1873 Enable this option to build test module which validates per-cpu
1874 operations.
1875
1876 If unsure, say N.
1877
Dave Hansen881c5142013-07-01 13:04:44 -07001878config ATOMIC64_SELFTEST
Geert Uytterhoeven55ded952017-02-24 15:00:55 -08001879 tristate "Perform an atomic64_t self-test"
Dave Hansen881c5142013-07-01 13:04:44 -07001880 help
Geert Uytterhoeven55ded952017-02-24 15:00:55 -08001881 Enable this option to test the atomic64_t functions at boot or
1882 at module load time.
Dave Hansen881c5142013-07-01 13:04:44 -07001883
1884 If unsure, say N.
1885
1886config ASYNC_RAID6_TEST
1887 tristate "Self test for hardware accelerated raid6 recovery"
1888 depends on ASYNC_RAID6_RECOV
1889 select ASYNC_MEMCPY
1890 ---help---
1891 This is a one-shot self test that permutes through the
1892 recovery of all the possible two disk failure scenarios for a
1893 N-disk array. Recovery is performed with the asynchronous
1894 raid6 recovery routines, and will optionally use an offload
1895 engine if one is available.
1896
1897 If unsure, say N.
1898
Andy Shevchenko64d1d772015-02-12 15:02:21 -08001899config TEST_HEXDUMP
1900 tristate "Test functions located in the hexdump module at runtime"
1901
Dave Hansen881c5142013-07-01 13:04:44 -07001902config TEST_STRING_HELPERS
1903 tristate "Test functions located in the string_helpers module at runtime"
1904
Tobin C. Harding0b0600c82019-04-05 12:58:59 +11001905config TEST_STRSCPY
1906 tristate "Test strscpy*() family of functions at runtime"
1907
Dave Hansen881c5142013-07-01 13:04:44 -07001908config TEST_KSTRTOX
1909 tristate "Test kstrto*() family of functions at runtime"
1910
Rasmus Villemoes707cc722015-11-06 16:30:29 -08001911config TEST_PRINTF
1912 tristate "Test printf() family of functions at runtime"
1913
David Decotigny5fd003f2016-02-19 09:24:00 -05001914config TEST_BITMAP
1915 tristate "Test bitmap_*() family of functions at runtime"
David Decotigny5fd003f2016-02-19 09:24:00 -05001916 help
1917 Enable this option to test the bitmap functions at boot.
1918
1919 If unsure, say N.
1920
Johannes Berg0e2dc702018-06-20 08:58:30 +02001921config TEST_BITFIELD
1922 tristate "Test bitfield functions at runtime"
1923 help
1924 Enable this option to test the bitfield functions at boot.
1925
1926 If unsure, say N.
1927
Andy Shevchenkocfaff0e2016-05-30 17:40:41 +03001928config TEST_UUID
1929 tristate "Test functions located in the uuid module at runtime"
1930
Matthew Wilcoxad3d6c72017-11-07 14:57:46 -05001931config TEST_XARRAY
1932 tristate "Test the XArray code at runtime"
1933
Rasmus Villemoes455a35a2018-05-08 00:36:28 +02001934config TEST_OVERFLOW
1935 tristate "Test check_*_overflow() functions at runtime"
1936
Thomas Graf7e1e7762014-08-02 11:47:44 +02001937config TEST_RHASHTABLE
Geert Uytterhoeven9d6dbe12015-01-29 15:40:25 +01001938 tristate "Perform selftest on resizable hash table"
Thomas Graf7e1e7762014-08-02 11:47:44 +02001939 help
1940 Enable this option to test the rhashtable functions at boot.
1941
1942 If unsure, say N.
1943
George Spelvin468a9422016-05-26 22:11:51 -04001944config TEST_HASH
1945 tristate "Perform selftest on hash functions"
George Spelvin468a9422016-05-26 22:11:51 -04001946 help
Jason A. Donenfeld2c956a62017-01-08 13:54:00 +01001947 Enable this option to test the kernel's integer (<linux/hash.h>),
1948 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
1949 hash functions on boot (or module load).
George Spelvin468a9422016-05-26 22:11:51 -04001950
1951 This is intended to help people writing architecture-specific
1952 optimized versions. If unsure, say N.
1953
Matthew Wilcox8ab8ba32018-06-18 16:59:29 -04001954config TEST_IDA
1955 tristate "Perform selftest on IDA functions"
1956
Jiri Pirko44091d22017-02-03 10:29:06 +01001957config TEST_PARMAN
1958 tristate "Perform selftest on priority array manager"
Jiri Pirko44091d22017-02-03 10:29:06 +01001959 depends on PARMAN
1960 help
1961 Enable this option to test priority array manager on boot
1962 (or module load).
1963
1964 If unsure, say N.
1965
Daniel Lezcano6aed82d2019-05-27 22:55:19 +02001966config TEST_IRQ_TIMINGS
1967 bool "IRQ timings selftest"
1968 depends on IRQ_TIMINGS
1969 help
1970 Enable this option to test the irq timings code on boot.
1971
1972 If unsure, say N.
1973
Valentin Rothberg8a6f0b42014-10-13 15:51:38 -07001974config TEST_LKM
Kees Cook93e9ef82014-01-23 15:54:37 -08001975 tristate "Test module loading with 'hello world' module"
Kees Cook93e9ef82014-01-23 15:54:37 -08001976 depends on m
1977 help
1978 This builds the "test_module" module that emits "Hello, world"
1979 on printk when loaded. It is designed to be used for basic
1980 evaluation of the module loading subsystem (for example when
1981 validating module verification). It lacks any extra dependencies,
1982 and will not normally be loaded by the system unless explicitly
1983 requested by name.
1984
1985 If unsure, say N.
1986
Uladzislau Rezki (Sony)3f21a6b2019-03-05 15:43:34 -08001987config TEST_VMALLOC
1988 tristate "Test module for stress/performance analysis of vmalloc allocator"
1989 default n
1990 depends on MMU
1991 depends on m
1992 help
1993 This builds the "test_vmalloc" module that should be used for
1994 stress and performance analysis. So, any new change for vmalloc
1995 subsystem can be evaluated from performance and stability point
1996 of view.
1997
1998 If unsure, say N.
1999
Kees Cook3e2a4c12014-01-23 15:54:38 -08002000config TEST_USER_COPY
2001 tristate "Test user/kernel boundary protections"
Kees Cook3e2a4c12014-01-23 15:54:38 -08002002 depends on m
2003 help
2004 This builds the "test_user_copy" module that runs sanity checks
2005 on the copy_to/from_user infrastructure, making sure basic
2006 user/kernel boundary testing is working. If it fails to load,
2007 a regression has been detected in the user/kernel memory boundary
2008 protections.
2009
2010 If unsure, say N.
2011
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002012config TEST_BPF
2013 tristate "Test BPF filter functionality"
Randy Dunlap98920ba2014-05-13 09:58:44 -07002014 depends on m && NET
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002015 help
2016 This builds the "test_bpf" module that runs various test vectors
2017 against the BPF interpreter or BPF JIT compiler depending on the
2018 current setting. This is in particular useful for BPF JIT compiler
2019 development, but also to run regression tests against changes in
Alexei Starovoitov3c731eb2014-09-26 00:17:07 -07002020 the interpreter code. It also enables test stubs for eBPF maps and
2021 verifier used by user space verifier testsuite.
Alexei Starovoitov64a89462014-05-08 14:10:52 -07002022
2023 If unsure, say N.
2024
Mahesh Bandewar509e56b2019-07-01 14:39:01 -07002025config TEST_BLACKHOLE_DEV
2026 tristate "Test blackhole netdev functionality"
2027 depends on m && NET
2028 help
2029 This builds the "test_blackhole_dev" module that validates the
2030 data path through this blackhole netdev.
2031
2032 If unsure, say N.
2033
Yury Norovdceeb3e2018-02-06 15:38:27 -08002034config FIND_BIT_BENCHMARK
Yury Norov4441fca2017-11-17 15:28:31 -08002035 tristate "Test find_bit functions"
Yury Norov4441fca2017-11-17 15:28:31 -08002036 help
2037 This builds the "test_find_bit" module that measure find_*_bit()
2038 functions performance.
2039
2040 If unsure, say N.
2041
Kees Cook0a8adf52014-07-14 14:38:12 -07002042config TEST_FIRMWARE
2043 tristate "Test firmware loading via userspace interface"
Kees Cook0a8adf52014-07-14 14:38:12 -07002044 depends on FW_LOADER
2045 help
2046 This builds the "test_firmware" module that creates a userspace
2047 interface for testing firmware loading. This can be used to
2048 control the triggering of firmware loading without needing an
2049 actual firmware-using device. The contents can be rechecked by
2050 userspace.
2051
2052 If unsure, say N.
2053
Luis R. Rodriguez9308f2f2017-07-12 14:33:43 -07002054config TEST_SYSCTL
2055 tristate "sysctl test driver"
Luis R. Rodriguez9308f2f2017-07-12 14:33:43 -07002056 depends on PROC_SYSCTL
2057 help
2058 This builds the "test_sysctl" module. This driver enables to test the
2059 proc sysctl interfaces available to drivers safely without affecting
2060 production knobs which might alter system functionality.
2061
2062 If unsure, say N.
2063
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002064config SYSCTL_KUNIT_TEST
Alan Maguirec475c772020-01-06 22:28:20 +00002065 tristate "KUnit test for sysctl"
Iurii Zaikin2cb80db2019-09-23 02:02:47 -07002066 depends on KUNIT
2067 help
2068 This builds the proc sysctl unit test, which runs on boot.
2069 Tests the API contract and implementation correctness of sysctl.
2070 For more information on KUnit and unit tests in general please refer
2071 to the KUnit documentation in Documentation/dev-tools/kunit/.
2072
2073 If unsure, say N.
2074
David Gowea2dd7c2019-10-24 15:46:31 -07002075config LIST_KUNIT_TEST
Alan Maguirec475c772020-01-06 22:28:20 +00002076 tristate "KUnit Test for Kernel Linked-list structures"
David Gowea2dd7c2019-10-24 15:46:31 -07002077 depends on KUNIT
2078 help
2079 This builds the linked list KUnit test suite.
2080 It tests that the API and basic functionality of the list_head type
2081 and associated macros.
2082
2083 KUnit tests run during boot and output the results to the debug log
2084 in TAP format (http://testanything.org/). Only useful for kernel devs
2085 running the KUnit test harness, and not intended for inclusion into a
2086 production build.
2087
2088 For more information on KUnit and unit tests in general please refer
2089 to the KUnit documentation in Documentation/dev-tools/kunit/.
2090
2091 If unsure, say N.
2092
David Rileye704f932014-06-16 14:58:32 -07002093config TEST_UDELAY
2094 tristate "udelay test driver"
David Rileye704f932014-06-16 14:58:32 -07002095 help
2096 This builds the "udelay_test" module that helps to make sure
2097 that udelay() is working properly.
2098
2099 If unsure, say N.
2100
Ingo Molnar2bf9e0a2015-08-03 11:42:57 +02002101config TEST_STATIC_KEYS
2102 tristate "Test static keys"
Jason Baron579e1ac2015-07-30 03:59:44 +00002103 depends on m
2104 help
Ingo Molnar2bf9e0a2015-08-03 11:42:57 +02002105 Test the static key interfaces.
Jason Baron579e1ac2015-07-30 03:59:44 +00002106
2107 If unsure, say N.
2108
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002109config TEST_KMOD
2110 tristate "kmod stress tester"
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002111 depends on m
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002112 depends on NETDEVICES && NET_CORE && INET # for TUN
YueHaibingae3d6a32019-04-25 22:23:44 -07002113 depends on BLOCK
Luis R. Rodriguezd9c6a722017-07-14 14:50:08 -07002114 select TEST_LKM
2115 select XFS_FS
2116 select TUN
2117 select BTRFS_FS
2118 help
2119 Test the kernel's module loading mechanism: kmod. kmod implements
2120 support to load modules using the Linux kernel's usermode helper.
2121 This test provides a series of tests against kmod.
2122
2123 Although technically you can either build test_kmod as a module or
2124 into the kernel we disallow building it into the kernel since
2125 it stress tests request_module() and this will very likely cause
2126 some issues by taking over precious threads available from other
2127 module load requests, ultimately this could be fatal.
2128
2129 To run tests run:
2130
2131 tools/testing/selftests/kmod/kmod.sh --help
2132
2133 If unsure, say N.
2134
Florian Fainellie4dace32017-09-08 16:15:31 -07002135config TEST_DEBUG_VIRTUAL
2136 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2137 depends on DEBUG_VIRTUAL
2138 help
2139 Test the kernel's ability to detect incorrect calls to
2140 virt_to_phys() done against the non-linear part of the
2141 kernel's virtual address map.
2142
2143 If unsure, say N.
2144
Alexander Shishkince76d932018-10-05 15:43:05 +03002145config TEST_MEMCAT_P
2146 tristate "Test memcat_p() helper function"
2147 help
2148 Test the memcat_p() helper for correctly merging two
2149 pointer arrays together.
2150
2151 If unsure, say N.
2152
Joe Lawrencea2818ee2019-01-09 13:43:29 +01002153config TEST_LIVEPATCH
2154 tristate "Test livepatching"
2155 default n
Joe Lawrencebae05432019-01-31 11:41:24 -05002156 depends on DYNAMIC_DEBUG
Joe Lawrencea2818ee2019-01-09 13:43:29 +01002157 depends on LIVEPATCH
2158 depends on m
2159 help
2160 Test kernel livepatching features for correctness. The tests will
2161 load test modules that will be livepatched in various scenarios.
2162
2163 To run all the livepatching tests:
2164
2165 make -C tools/testing/selftests TARGETS=livepatch run_tests
2166
2167 Alternatively, individual tests may be invoked:
2168
2169 tools/testing/selftests/livepatch/test-callbacks.sh
2170 tools/testing/selftests/livepatch/test-livepatch.sh
2171 tools/testing/selftests/livepatch/test-shadow-vars.sh
2172
2173 If unsure, say N.
2174
Jiri Pirko0a020d42018-11-14 08:22:28 +00002175config TEST_OBJAGG
2176 tristate "Perform selftest on object aggreration manager"
2177 default n
2178 depends on OBJAGG
2179 help
2180 Enable this option to test object aggregation manager on boot
2181 (or module load).
2182
Jiri Pirko0a020d42018-11-14 08:22:28 +00002183
Kees Cook50ceaa95e2019-01-23 12:24:32 -07002184config TEST_STACKINIT
2185 tristate "Test level of stack variable initialization"
2186 help
2187 Test if the kernel is zero-initializing stack variables and
2188 padding. Coverage is controlled by compiler flags,
2189 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2190 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2191
2192 If unsure, say N.
2193
Alexander Potapenko5015a302019-07-16 16:27:27 -07002194config TEST_MEMINIT
2195 tristate "Test heap/page initialization"
2196 help
2197 Test if the kernel is zero-initializing heap and page allocations.
2198 This can be useful to test init_on_alloc and init_on_free features.
2199
2200 If unsure, say N.
2201
Vincent Legolld3deafa2018-02-06 15:38:38 -08002202endif # RUNTIME_TESTING_MENU
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002203
2204config MEMTEST
2205 bool "Memtest"
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002206 ---help---
2207 This option adds a kernel parameter 'memtest', which allows memtest
2208 to be set.
2209 memtest=0, mean disabled; -- default
2210 memtest=1, mean do 1 test pattern;
2211 ...
2212 memtest=17, mean do 17 test patterns.
2213 If you are unsure how to answer this question, answer N.
2214
Randy Dunlapcc3fa842017-10-13 15:57:33 -07002215
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002216
Branden Bonabyaf9ca6f2019-10-03 17:01:49 -04002217config HYPERV_TESTING
2218 bool "Microsoft Hyper-V driver testing"
2219 default n
2220 depends on HYPERV && DEBUG_FS
2221 help
2222 Select this option to enable Hyper-V vmbus testing.
2223
Changbin Du045f6d72019-12-17 20:51:56 -08002224endmenu # "Kernel Testing and Coverage"
2225
Christoph Hellwig06ec64b2018-07-31 13:39:31 +02002226endmenu # Kernel hacking