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