1 # SPDX-License-Identifier: GPL-2.0-only
4 menu "printk and dmesg options"
7 bool "Show timing information on printks"
10 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.
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.
18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
22 bool "Show caller information on printks"
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)
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.
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
38 config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
49 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
54 Default loglevel to determine what will be printed on the console.
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
60 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
64 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
69 loglevel to use when "quiet" is passed on the kernel commandline.
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
75 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)"
80 Default log level for printk statements with no specified priority.
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
90 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
109 bool "Enable dynamic printk() support"
112 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
138 filename:lineno [module]function flags format
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
180 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
183 depends on (DEBUG_FS || PROC_FS)
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
191 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
200 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
209 endmenu # "printk and dmesg options"
212 bool "Kernel debugging"
214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems.
218 bool "Miscellaneous debug code"
220 depends on DEBUG_KERNEL
222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug option but isn't.
225 menu "Compile-time checks and compiler options"
230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice below, indicating that debug
232 information will be generated for build targets.
235 prompt "Debug information"
236 depends on DEBUG_KERNEL
238 Selecting something other than "None" results in a kernel image
239 that will include debugging info resulting in a larger kernel image.
240 This adds debug symbols to the kernel and modules (gcc -g), and
241 is needed if you intend to use kernel crashdump or binary object
242 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
244 Choose which version of DWARF debug info to emit. If unsure,
245 select "Toolchain default".
247 config DEBUG_INFO_NONE
248 bool "Disable debug information"
250 Do not build the kernel with debugging information, which will
251 result in a faster and smaller build.
253 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
254 bool "Rely on the toolchain's implicit default DWARF version"
257 The implicit default version of DWARF debug info produced by a
258 toolchain changes over time.
260 This can break consumers of the debug info that haven't upgraded to
261 support newer revisions, and prevent testing newer versions, but
262 those should be less common scenarios.
264 config DEBUG_INFO_DWARF4
265 bool "Generate DWARF Version 4 debuginfo"
267 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
269 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
270 if using clang without clang's integrated assembler, and gdb 7.0+.
272 If you have consumers of DWARF debug info that are not ready for
273 newer revisions of DWARF, you may wish to choose this or have your
276 config DEBUG_INFO_DWARF5
277 bool "Generate DWARF Version 5 debuginfo"
279 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
281 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
282 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
283 draft features until 7.0), and gdb 8.0+.
285 Changes to the structure of debug info in Version 5 allow for around
286 15-18% savings in resulting image and debug info section sizes as
287 compared to DWARF Version 4. DWARF Version 5 standardizes previous
288 extensions such as accelerators for symbol indexing and the format
289 for fission (.dwo/.dwp) files. Users may not want to select this
290 config if they rely on tooling that has not yet been updated to
291 support DWARF Version 5.
293 endchoice # "Debug information"
297 config DEBUG_INFO_REDUCED
298 bool "Reduce debugging information"
300 If you say Y here gcc is instructed to generate less debugging
301 information for structure types. This means that tools that
302 need full debugging information (like kgdb or systemtap) won't
303 be happy. But if you merely need debugging information to
304 resolve line numbers there is no loss. Advantage is that
305 build directory object sizes shrink dramatically over a full
306 DEBUG_INFO build and compile times are reduced too.
307 Only works with newer gcc versions.
309 config DEBUG_INFO_COMPRESSED
310 bool "Compressed debugging information"
311 depends on $(cc-option,-gz=zlib)
312 depends on $(ld-option,--compress-debug-sections=zlib)
314 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
315 5.0+, binutils 2.26+, and zlib.
317 Users of dpkg-deb via scripts/package/builddeb may find an increase in
318 size of their debug .deb packages with this config set, due to the
319 debug info being compressed with zlib, then the object files being
320 recompressed with a different compression scheme. But this is still
321 preferable to setting $KDEB_COMPRESS to "none" which would be even
324 config DEBUG_INFO_SPLIT
325 bool "Produce split debuginfo in .dwo files"
326 depends on $(cc-option,-gsplit-dwarf)
328 Generate debug info into separate .dwo files. This significantly
329 reduces the build directory size for builds with DEBUG_INFO,
330 because it stores the information only once on disk in .dwo
331 files instead of multiple times in object files and executables.
332 In addition the debug information is also compressed.
334 Requires recent gcc (4.7+) and recent gdb/binutils.
335 Any tool that packages or reads debug information would need
336 to know about the .dwo files and include them.
337 Incompatible with older versions of ccache.
339 config DEBUG_INFO_BTF
340 bool "Generate BTF typeinfo"
341 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
342 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
343 depends on BPF_SYSCALL
344 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
346 Generate deduplicated BTF type information from DWARF debug info.
347 Turning this on expects presence of pahole tool, which will convert
348 DWARF type info into equivalent deduplicated BTF type info.
350 config PAHOLE_HAS_SPLIT_BTF
351 def_bool PAHOLE_VERSION >= 119
353 config PAHOLE_HAS_BTF_TAG
354 def_bool PAHOLE_VERSION >= 123
355 depends on CC_IS_CLANG
357 Decide whether pahole emits btf_tag attributes (btf_type_tag and
358 btf_decl_tag) or not. Currently only clang compiler implements
359 these attributes, so make the config depend on CC_IS_CLANG.
361 config DEBUG_INFO_BTF_MODULES
363 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
365 Generate compact split BTF type information for kernel modules.
367 config MODULE_ALLOW_BTF_MISMATCH
368 bool "Allow loading modules with non-matching BTF type info"
369 depends on DEBUG_INFO_BTF_MODULES
371 For modules whose split BTF does not match vmlinux, load without
372 BTF rather than refusing to load. The default behavior with
373 module BTF enabled is to reject modules with such mismatches;
374 this option will still load module BTF where possible but ignore
375 it when a mismatch is found.
378 bool "Provide GDB scripts for kernel debugging"
380 This creates the required links to GDB helper scripts in the
381 build directory. If you load vmlinux into gdb, the helper
382 scripts will be automatically imported by gdb as well, and
383 additional functions are available to analyze a Linux kernel
384 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
390 int "Warn for stack frames larger than"
392 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
393 default 2048 if PARISC
394 default 1536 if (!64BIT && XTENSA)
395 default 1024 if !64BIT
396 default 2048 if 64BIT
398 Tell gcc to warn at build time for stack frames larger than this.
399 Setting this too low will cause a lot of warnings.
400 Setting it to 0 disables the warning.
402 config STRIP_ASM_SYMS
403 bool "Strip assembler-generated symbols during link"
406 Strip internal assembler-generated symbols during a link (symbols
407 that look like '.Lxxx') so they don't pollute the output of
408 get_wchan() and suchlike.
411 bool "Generate readable assembler code"
412 depends on DEBUG_KERNEL
415 Disable some compiler optimizations that tend to generate human unreadable
416 assembler output. This may make the kernel slightly slower, but it helps
417 to keep kernel developers who have to stare a lot at assembler listings
420 config HEADERS_INSTALL
421 bool "Install uapi headers to usr/include"
424 This option will install uapi headers (headers exported to user-space)
425 into the usr/include directory for use during the kernel build.
426 This is unneeded for building the kernel itself, but needed for some
427 user-space program samples. It is also needed by some features such
428 as uapi header sanity checks.
430 config DEBUG_SECTION_MISMATCH
431 bool "Enable full Section mismatch analysis"
434 The section mismatch analysis checks if there are illegal
435 references from one section to another section.
436 During linktime or runtime, some sections are dropped;
437 any use of code/data previously in these sections would
438 most likely result in an oops.
439 In the code, functions and variables are annotated with
440 __init,, etc. (see the full list in include/linux/init.h),
441 which results in the code/data being placed in specific sections.
442 The section mismatch analysis is always performed after a full
443 kernel build, and enabling this option causes the following
444 additional step to occur:
445 - Add the option -fno-inline-functions-called-once to gcc commands.
446 When inlining a function annotated with __init in a non-init
447 function, we would lose the section information and thus
448 the analysis would not catch the illegal reference.
449 This option tells gcc to inline less (but it does result in
452 config SECTION_MISMATCH_WARN_ONLY
453 bool "Make section mismatch errors non-fatal"
456 If you say N here, the build process will fail if there are any
457 section mismatch, instead of just throwing warnings.
461 config DEBUG_FORCE_FUNCTION_ALIGN_64B
462 bool "Force all function address 64B aligned"
463 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
465 There are cases that a commit from one domain changes the function
466 address alignment of other domains, and cause magic performance
467 bump (regression or improvement). Enable this option will help to
468 verify if the bump is caused by function alignment changes, while
469 it will slightly increase the kernel size and affect icache usage.
471 It is mainly for debug and performance tuning use.
474 # Select this config option from the architecture Kconfig, if it
475 # is preferred to always offer frame pointers as a config
476 # option on the architecture (regardless of KERNEL_DEBUG):
478 config ARCH_WANT_FRAME_POINTERS
482 bool "Compile the kernel with frame pointers"
483 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
484 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
486 If you say Y here the resulting kernel image will be slightly
487 larger and slower, but it gives very useful debugging information
488 in case of kernel bugs. (precise oopses/stacktraces/warnings)
493 config STACK_VALIDATION
494 bool "Compile-time stack metadata validation"
495 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
499 Validate frame pointer rules at compile-time. This helps ensure that
500 runtime stack traces are more reliable.
502 For more information, see
503 tools/objtool/Documentation/objtool.txt.
505 config NOINSTR_VALIDATION
507 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
512 bool "Generate vmlinux.map file when linking"
515 Selecting this option will pass "-Map=vmlinux.map" to ld
516 when linking vmlinux. That file can be useful for verifying
517 and debugging magic section games, and for seeing which
518 pieces of code get eliminated with
519 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
521 config DEBUG_FORCE_WEAK_PER_CPU
522 bool "Force weak per-cpu definitions"
523 depends on DEBUG_KERNEL
525 s390 and alpha require percpu variables in modules to be
526 defined weak to work around addressing range issue which
527 puts the following two restrictions on percpu variable
530 1. percpu symbols must be unique whether static or not
531 2. percpu variables can't be defined inside a function
533 To ensure that generic code follows the above rules, this
534 option forces all percpu variables to be defined as weak.
536 endmenu # "Compiler options"
538 menu "Generic Kernel Debugging Instruments"
541 bool "Magic SysRq key"
544 If you say Y here, you will have some control over the system even
545 if the system crashes for example during kernel debugging (e.g., you
546 will be able to flush the buffer cache to disk, reboot the system
547 immediately or dump some status information). This is accomplished
548 by pressing various keys while holding SysRq (Alt+PrintScreen). It
549 also works on a serial console (on PC hardware at least), if you
550 send a BREAK and then within 5 seconds a command keypress. The
551 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
552 Don't say Y unless you really know what this hack does.
554 config MAGIC_SYSRQ_DEFAULT_ENABLE
555 hex "Enable magic SysRq key functions by default"
556 depends on MAGIC_SYSRQ
559 Specifies which SysRq key functions are enabled by default.
560 This may be set to 1 or 0 to enable or disable them all, or
561 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
563 config MAGIC_SYSRQ_SERIAL
564 bool "Enable magic SysRq key over serial"
565 depends on MAGIC_SYSRQ
568 Many embedded boards have a disconnected TTL level serial which can
569 generate some garbage that can lead to spurious false sysrq detects.
570 This option allows you to decide whether you want to enable the
573 config MAGIC_SYSRQ_SERIAL_SEQUENCE
574 string "Char sequence that enables magic SysRq over serial"
575 depends on MAGIC_SYSRQ_SERIAL
578 Specifies a sequence of characters that can follow BREAK to enable
579 SysRq on a serial console.
581 If unsure, leave an empty string and the option will not be enabled.
584 bool "Debug Filesystem"
586 debugfs is a virtual file system that kernel developers use to put
587 debugging files into. Enable this option to be able to read and
588 write to these files.
590 For detailed documentation on the debugfs API, see
591 Documentation/filesystems/.
596 prompt "Debugfs default access"
598 default DEBUG_FS_ALLOW_ALL
600 This selects the default access restrictions for debugfs.
601 It can be overridden with kernel command line option
602 debugfs=[on,no-mount,off]. The restrictions apply for API access
603 and filesystem registration.
605 config DEBUG_FS_ALLOW_ALL
608 No restrictions apply. Both API and filesystem registration
609 is on. This is the normal default operation.
611 config DEBUG_FS_DISALLOW_MOUNT
612 bool "Do not register debugfs as filesystem"
614 The API is open but filesystem is not loaded. Clients can still do
615 their work and read with debug tools that do not need
618 config DEBUG_FS_ALLOW_NONE
621 Access is off. Clients get -PERM when trying to create nodes in
622 debugfs tree and debugfs is not registered as a filesystem.
623 Client can then back-off or continue without debugfs access.
627 source "lib/Kconfig.kgdb"
628 source "lib/Kconfig.ubsan"
629 source "lib/Kconfig.kcsan"
633 menu "Networking Debugging"
635 source "net/Kconfig.debug"
637 endmenu # "Networking Debugging"
639 menu "Memory Debugging"
641 source "mm/Kconfig.debug"
644 bool "Debug object operations"
645 depends on DEBUG_KERNEL
647 If you say Y here, additional code will be inserted into the
648 kernel to track the life time of various objects and validate
649 the operations on those objects.
651 config DEBUG_OBJECTS_SELFTEST
652 bool "Debug objects selftest"
653 depends on DEBUG_OBJECTS
655 This enables the selftest of the object debug code.
657 config DEBUG_OBJECTS_FREE
658 bool "Debug objects in freed memory"
659 depends on DEBUG_OBJECTS
661 This enables checks whether a k/v free operation frees an area
662 which contains an object which has not been deactivated
663 properly. This can make kmalloc/kfree-intensive workloads
666 config DEBUG_OBJECTS_TIMERS
667 bool "Debug timer objects"
668 depends on DEBUG_OBJECTS
670 If you say Y here, additional code will be inserted into the
671 timer routines to track the life time of timer objects and
672 validate the timer operations.
674 config DEBUG_OBJECTS_WORK
675 bool "Debug work objects"
676 depends on DEBUG_OBJECTS
678 If you say Y here, additional code will be inserted into the
679 work queue routines to track the life time of work objects and
680 validate the work operations.
682 config DEBUG_OBJECTS_RCU_HEAD
683 bool "Debug RCU callbacks objects"
684 depends on DEBUG_OBJECTS
686 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
688 config DEBUG_OBJECTS_PERCPU_COUNTER
689 bool "Debug percpu counter objects"
690 depends on DEBUG_OBJECTS
692 If you say Y here, additional code will be inserted into the
693 percpu counter routines to track the life time of percpu counter
694 objects and validate the percpu counter operations.
696 config DEBUG_OBJECTS_ENABLE_DEFAULT
697 int "debug_objects bootup default value (0-1)"
700 depends on DEBUG_OBJECTS
702 Debug objects boot parameter default value
704 config SHRINKER_DEBUG
705 bool "Enable shrinker debugging support"
708 Say Y to enable the shrinker debugfs interface which provides
709 visibility into the kernel memory shrinkers subsystem.
710 Disable it to avoid an extra memory footprint.
712 config HAVE_DEBUG_KMEMLEAK
715 config DEBUG_KMEMLEAK
716 bool "Kernel memory leak detector"
717 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
719 select STACKTRACE if STACKTRACE_SUPPORT
723 Say Y here if you want to enable the memory leak
724 detector. The memory allocation/freeing is traced in a way
725 similar to the Boehm's conservative garbage collector, the
726 difference being that the orphan objects are not freed but
727 only shown in /sys/kernel/debug/kmemleak. Enabling this
728 feature will introduce an overhead to memory
729 allocations. See Documentation/dev-tools/kmemleak.rst for more
732 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
733 of finding leaks due to the slab objects poisoning.
735 In order to access the kmemleak file, debugfs needs to be
736 mounted (usually at /sys/kernel/debug).
738 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
739 int "Kmemleak memory pool size"
740 depends on DEBUG_KMEMLEAK
744 Kmemleak must track all the memory allocations to avoid
745 reporting false positives. Since memory may be allocated or
746 freed before kmemleak is fully initialised, use a static pool
747 of metadata objects to track such callbacks. After kmemleak is
748 fully initialised, this memory pool acts as an emergency one
749 if slab allocations fail.
751 config DEBUG_KMEMLEAK_TEST
752 tristate "Simple test for the kernel memory leak detector"
753 depends on DEBUG_KMEMLEAK && m
755 This option enables a module that explicitly leaks memory.
759 config DEBUG_KMEMLEAK_DEFAULT_OFF
760 bool "Default kmemleak to off"
761 depends on DEBUG_KMEMLEAK
763 Say Y here to disable kmemleak by default. It can then be enabled
764 on the command line via kmemleak=on.
766 config DEBUG_KMEMLEAK_AUTO_SCAN
767 bool "Enable kmemleak auto scan thread on boot up"
769 depends on DEBUG_KMEMLEAK
771 Depending on the cpu, kmemleak scan may be cpu intensive and can
772 stall user tasks at times. This option enables/disables automatic
773 kmemleak scan at boot up.
775 Say N here to disable kmemleak auto scan thread to stop automatic
776 scanning. Disabling this option disables automatic reporting of
781 config DEBUG_STACK_USAGE
782 bool "Stack utilization instrumentation"
783 depends on DEBUG_KERNEL && !IA64
785 Enables the display of the minimum amount of free stack which each
786 task has ever had available in the sysrq-T and sysrq-P debug output.
788 This option will slow down process creation somewhat.
790 config SCHED_STACK_END_CHECK
791 bool "Detect stack corruption on calls to schedule()"
792 depends on DEBUG_KERNEL
795 This option checks for a stack overrun on calls to schedule().
796 If the stack end location is found to be over written always panic as
797 the content of the corrupted region can no longer be trusted.
798 This is to ensure no erroneous behaviour occurs which could result in
799 data corruption or a sporadic crash at a later stage once the region
800 is examined. The runtime overhead introduced is minimal.
802 config ARCH_HAS_DEBUG_VM_PGTABLE
805 An architecture should select this when it can successfully
806 build and run DEBUG_VM_PGTABLE.
808 config DEBUG_VM_IRQSOFF
809 def_bool DEBUG_VM && !PREEMPT_RT
813 depends on DEBUG_KERNEL
815 Enable this to turn on extended checks in the virtual-memory system
816 that may impact performance.
820 config DEBUG_VM_MAPLE_TREE
821 bool "Debug VM maple trees"
823 select DEBUG_MAPLE_TREE
825 Enable VM maple tree debugging information and extra validations.
830 bool "Debug VM red-black trees"
833 Enable VM red-black tree debugging information and extra validations.
837 config DEBUG_VM_PGFLAGS
838 bool "Debug page-flags operations"
841 Enables extra validation on page flags operations.
845 config DEBUG_VM_PGTABLE
846 bool "Debug arch page table for semantics compliance"
848 depends on ARCH_HAS_DEBUG_VM_PGTABLE
849 default y if DEBUG_VM
851 This option provides a debug method which can be used to test
852 architecture page table helper functions on various platforms in
853 verifying if they comply with expected generic MM semantics. This
854 will help architecture code in making sure that any changes or
855 new additions of these helpers still conform to expected
856 semantics of the generic MM. Platforms will have to opt in for
857 this through ARCH_HAS_DEBUG_VM_PGTABLE.
861 config ARCH_HAS_DEBUG_VIRTUAL
865 bool "Debug VM translations"
866 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
868 Enable some costly sanity checks in virtual to page code. This can
869 catch mistakes with virt_to_page() and friends.
873 config DEBUG_NOMMU_REGIONS
874 bool "Debug the global anon/private NOMMU mapping region tree"
875 depends on DEBUG_KERNEL && !MMU
877 This option causes the global tree of anonymous and private mapping
878 regions to be regularly checked for invalid topology.
880 config DEBUG_MEMORY_INIT
881 bool "Debug memory initialisation" if EXPERT
884 Enable this for additional checks during memory initialisation.
885 The sanity checks verify aspects of the VM such as the memory model
886 and other information provided by the architecture. Verbose
887 information will be printed at KERN_DEBUG loglevel depending
888 on the mminit_loglevel= command-line option.
892 config MEMORY_NOTIFIER_ERROR_INJECT
893 tristate "Memory hotplug notifier error injection module"
894 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
896 This option provides the ability to inject artificial errors to
897 memory hotplug notifier chain callbacks. It is controlled through
898 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
900 If the notifier call chain should be failed with some events
901 notified, write the error code to "actions/<notifier event>/error".
903 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
905 # cd /sys/kernel/debug/notifier-error-inject/memory
906 # echo -12 > actions/MEM_GOING_OFFLINE/error
907 # echo offline > /sys/devices/system/memory/memoryXXX/state
908 bash: echo: write error: Cannot allocate memory
910 To compile this code as a module, choose M here: the module will
911 be called memory-notifier-error-inject.
915 config DEBUG_PER_CPU_MAPS
916 bool "Debug access to per_cpu maps"
917 depends on DEBUG_KERNEL
920 Say Y to verify that the per_cpu map being accessed has
921 been set up. This adds a fair amount of code to kernel memory
922 and decreases performance.
926 config DEBUG_KMAP_LOCAL
927 bool "Debug kmap_local temporary mappings"
928 depends on DEBUG_KERNEL && KMAP_LOCAL
930 This option enables additional error checking for the kmap_local
931 infrastructure. Disable for production use.
933 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
936 config DEBUG_KMAP_LOCAL_FORCE_MAP
937 bool "Enforce kmap_local temporary mappings"
938 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
940 select DEBUG_KMAP_LOCAL
942 This option enforces temporary mappings through the kmap_local
943 mechanism for non-highmem pages and on non-highmem systems.
944 Disable this for production systems!
947 bool "Highmem debugging"
948 depends on DEBUG_KERNEL && HIGHMEM
949 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
950 select DEBUG_KMAP_LOCAL
952 This option enables additional error checking for high memory
953 systems. Disable for production systems.
955 config HAVE_DEBUG_STACKOVERFLOW
958 config DEBUG_STACKOVERFLOW
959 bool "Check for stack overflows"
960 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
962 Say Y here if you want to check for overflows of kernel, IRQ
963 and exception stacks (if your architecture uses them). This
964 option will show detailed messages if free stack space drops
965 below a certain limit.
967 These kinds of bugs usually occur when call-chains in the
968 kernel get too deep, especially when interrupts are
971 Use this in cases where you see apparently random memory
972 corruption, especially if it appears in 'struct thread_info'
974 If in doubt, say "N".
976 source "lib/Kconfig.kasan"
977 source "lib/Kconfig.kfence"
978 source "lib/Kconfig.kmsan"
980 endmenu # "Memory Debugging"
983 bool "Debug shared IRQ handlers"
984 depends on DEBUG_KERNEL
986 Enable this to generate a spurious interrupt just before a shared
987 interrupt handler is deregistered (generating one when registering
988 is currently disabled). Drivers need to handle this correctly. Some
989 don't and need to be caught.
991 menu "Debug Oops, Lockups and Hangs"
996 Say Y here to enable the kernel to panic when it oopses. This
997 has the same effect as setting oops=panic on the kernel command
1000 This feature is useful to ensure that the kernel does not do
1001 anything erroneous after an oops which could result in data
1002 corruption or other issues.
1006 config PANIC_ON_OOPS_VALUE
1009 default 0 if !PANIC_ON_OOPS
1010 default 1 if PANIC_ON_OOPS
1012 config PANIC_TIMEOUT
1016 Set the timeout value (in seconds) until a reboot occurs when
1017 the kernel panics. If n = 0, then we wait forever. A timeout
1018 value n > 0 will wait n seconds before rebooting, while a timeout
1019 value n < 0 will reboot immediately.
1021 config LOCKUP_DETECTOR
1024 config SOFTLOCKUP_DETECTOR
1025 bool "Detect Soft Lockups"
1026 depends on DEBUG_KERNEL && !S390
1027 select LOCKUP_DETECTOR
1029 Say Y here to enable the kernel to act as a watchdog to detect
1032 Softlockups are bugs that cause the kernel to loop in kernel
1033 mode for more than 20 seconds, without giving other tasks a
1034 chance to run. The current stack trace is displayed upon
1035 detection and the system will stay locked up.
1037 config BOOTPARAM_SOFTLOCKUP_PANIC
1038 bool "Panic (Reboot) On Soft Lockups"
1039 depends on SOFTLOCKUP_DETECTOR
1041 Say Y here to enable the kernel to panic on "soft lockups",
1042 which are bugs that cause the kernel to loop in kernel
1043 mode for more than 20 seconds (configurable using the watchdog_thresh
1044 sysctl), without giving other tasks a chance to run.
1046 The panic can be used in combination with panic_timeout,
1047 to cause the system to reboot automatically after a
1048 lockup has been detected. This feature is useful for
1049 high-availability systems that have uptime guarantees and
1050 where a lockup must be resolved ASAP.
1054 config HARDLOCKUP_DETECTOR_PERF
1056 select SOFTLOCKUP_DETECTOR
1059 # Enables a timestamp based low pass filter to compensate for perf based
1060 # hard lockup detection which runs too fast due to turbo modes.
1062 config HARDLOCKUP_CHECK_TIMESTAMP
1066 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1067 # lockup detector rather than the perf based detector.
1069 config HARDLOCKUP_DETECTOR
1070 bool "Detect Hard Lockups"
1071 depends on DEBUG_KERNEL && !S390
1072 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1073 select LOCKUP_DETECTOR
1074 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1076 Say Y here to enable the kernel to act as a watchdog to detect
1079 Hardlockups are bugs that cause the CPU to loop in kernel mode
1080 for more than 10 seconds, without letting other interrupts have a
1081 chance to run. The current stack trace is displayed upon detection
1082 and the system will stay locked up.
1084 config BOOTPARAM_HARDLOCKUP_PANIC
1085 bool "Panic (Reboot) On Hard Lockups"
1086 depends on HARDLOCKUP_DETECTOR
1088 Say Y here to enable the kernel to panic on "hard lockups",
1089 which are bugs that cause the kernel to loop in kernel
1090 mode with interrupts disabled for more than 10 seconds (configurable
1091 using the watchdog_thresh sysctl).
1095 config DETECT_HUNG_TASK
1096 bool "Detect Hung Tasks"
1097 depends on DEBUG_KERNEL
1098 default SOFTLOCKUP_DETECTOR
1100 Say Y here to enable the kernel to detect "hung tasks",
1101 which are bugs that cause the task to be stuck in
1102 uninterruptible "D" state indefinitely.
1104 When a hung task is detected, the kernel will print the
1105 current stack trace (which you should report), but the
1106 task will stay in uninterruptible state. If lockdep is
1107 enabled then all held locks will also be reported. This
1108 feature has negligible overhead.
1110 config DEFAULT_HUNG_TASK_TIMEOUT
1111 int "Default timeout for hung task detection (in seconds)"
1112 depends on DETECT_HUNG_TASK
1115 This option controls the default timeout (in seconds) used
1116 to determine when a task has become non-responsive and should
1119 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1120 sysctl or by writing a value to
1121 /proc/sys/kernel/hung_task_timeout_secs.
1123 A timeout of 0 disables the check. The default is two minutes.
1124 Keeping the default should be fine in most cases.
1126 config BOOTPARAM_HUNG_TASK_PANIC
1127 bool "Panic (Reboot) On Hung Tasks"
1128 depends on DETECT_HUNG_TASK
1130 Say Y here to enable the kernel to panic on "hung tasks",
1131 which are bugs that cause the kernel to leave a task stuck
1132 in uninterruptible "D" state.
1134 The panic can be used in combination with panic_timeout,
1135 to cause the system to reboot automatically after a
1136 hung task has been detected. This feature is useful for
1137 high-availability systems that have uptime guarantees and
1138 where a hung tasks must be resolved ASAP.
1143 bool "Detect Workqueue Stalls"
1144 depends on DEBUG_KERNEL
1146 Say Y here to enable stall detection on workqueues. If a
1147 worker pool doesn't make forward progress on a pending work
1148 item for over a given amount of time, 30s by default, a
1149 warning message is printed along with dump of workqueue
1150 state. This can be configured through kernel parameter
1151 "workqueue.watchdog_thresh" and its sysfs counterpart.
1154 tristate "Test module to generate lockups"
1157 This builds the "test_lockup" module that helps to make sure
1158 that watchdogs and lockup detectors are working properly.
1160 Depending on module parameters it could emulate soft or hard
1161 lockup, "hung task", or locking arbitrary lock for a long time.
1162 Also it could generate series of lockups with cooling-down periods.
1166 endmenu # "Debug lockups and hangs"
1168 menu "Scheduler Debugging"
1171 bool "Collect scheduler debugging info"
1172 depends on DEBUG_KERNEL && PROC_FS
1175 If you say Y here, the /proc/sched_debug file will be provided
1176 that can help debug the scheduler. The runtime overhead of this
1184 bool "Collect scheduler statistics"
1185 depends on DEBUG_KERNEL && PROC_FS
1188 If you say Y here, additional code will be inserted into the
1189 scheduler and related routines to collect statistics about
1190 scheduler behavior and provide them in /proc/schedstat. These
1191 stats may be useful for both tuning and debugging the scheduler
1192 If you aren't debugging the scheduler or trying to tune a specific
1193 application, you can say N to avoid the very slight overhead
1198 config DEBUG_TIMEKEEPING
1199 bool "Enable extra timekeeping sanity checking"
1201 This option will enable additional timekeeping sanity checks
1202 which may be helpful when diagnosing issues where timekeeping
1203 problems are suspected.
1205 This may include checks in the timekeeping hotpaths, so this
1206 option may have a (very small) performance impact to some
1211 config DEBUG_PREEMPT
1212 bool "Debug preemptible kernel"
1213 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1216 If you say Y here then the kernel will use a debug variant of the
1217 commonly used smp_processor_id() function and will print warnings
1218 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1219 will detect preemption count underflows.
1221 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1223 config LOCK_DEBUGGING_SUPPORT
1225 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1228 config PROVE_LOCKING
1229 bool "Lock debugging: prove locking correctness"
1230 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1232 select DEBUG_SPINLOCK
1233 select DEBUG_MUTEXES if !PREEMPT_RT
1234 select DEBUG_RT_MUTEXES if RT_MUTEXES
1236 select DEBUG_WW_MUTEX_SLOWPATH
1237 select DEBUG_LOCK_ALLOC
1238 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1239 select TRACE_IRQFLAGS
1242 This feature enables the kernel to prove that all locking
1243 that occurs in the kernel runtime is mathematically
1244 correct: that under no circumstance could an arbitrary (and
1245 not yet triggered) combination of observed locking
1246 sequences (on an arbitrary number of CPUs, running an
1247 arbitrary number of tasks and interrupt contexts) cause a
1250 In short, this feature enables the kernel to report locking
1251 related deadlocks before they actually occur.
1253 The proof does not depend on how hard and complex a
1254 deadlock scenario would be to trigger: how many
1255 participant CPUs, tasks and irq-contexts would be needed
1256 for it to trigger. The proof also does not depend on
1257 timing: if a race and a resulting deadlock is possible
1258 theoretically (no matter how unlikely the race scenario
1259 is), it will be proven so and will immediately be
1260 reported by the kernel (once the event is observed that
1261 makes the deadlock theoretically possible).
1263 If a deadlock is impossible (i.e. the locking rules, as
1264 observed by the kernel, are mathematically correct), the
1265 kernel reports nothing.
1267 NOTE: this feature can also be enabled for rwlocks, mutexes
1268 and rwsems - in which case all dependencies between these
1269 different locking variants are observed and mapped too, and
1270 the proof of observed correctness is also maintained for an
1271 arbitrary combination of these separate locking variants.
1273 For more details, see Documentation/locking/lockdep-design.rst.
1275 config PROVE_RAW_LOCK_NESTING
1276 bool "Enable raw_spinlock - spinlock nesting checks"
1277 depends on PROVE_LOCKING
1280 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1281 that the lock nesting rules for PREEMPT_RT enabled kernels are
1284 NOTE: There are known nesting problems. So if you enable this
1285 option expect lockdep splats until these problems have been fully
1286 addressed which is work in progress. This config switch allows to
1287 identify and analyze these problems. It will be removed and the
1288 check permanently enabled once the main issues have been fixed.
1290 If unsure, select N.
1293 bool "Lock usage statistics"
1294 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1296 select DEBUG_SPINLOCK
1297 select DEBUG_MUTEXES if !PREEMPT_RT
1298 select DEBUG_RT_MUTEXES if RT_MUTEXES
1299 select DEBUG_LOCK_ALLOC
1302 This feature enables tracking lock contention points
1304 For more details, see Documentation/locking/lockstat.rst
1306 This also enables lock events required by "perf lock",
1308 If you want to use "perf lock", you also need to turn on
1309 CONFIG_EVENT_TRACING.
1311 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1312 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1314 config DEBUG_RT_MUTEXES
1315 bool "RT Mutex debugging, deadlock detection"
1316 depends on DEBUG_KERNEL && RT_MUTEXES
1318 This allows rt mutex semantics violations and rt mutex related
1319 deadlocks (lockups) to be detected and reported automatically.
1321 config DEBUG_SPINLOCK
1322 bool "Spinlock and rw-lock debugging: basic checks"
1323 depends on DEBUG_KERNEL
1324 select UNINLINE_SPIN_UNLOCK
1326 Say Y here and build SMP to catch missing spinlock initialization
1327 and certain other kinds of spinlock errors commonly made. This is
1328 best used in conjunction with the NMI watchdog so that spinlock
1329 deadlocks are also debuggable.
1331 config DEBUG_MUTEXES
1332 bool "Mutex debugging: basic checks"
1333 depends on DEBUG_KERNEL && !PREEMPT_RT
1335 This feature allows mutex semantics violations to be detected and
1338 config DEBUG_WW_MUTEX_SLOWPATH
1339 bool "Wait/wound mutex debugging: Slowpath testing"
1340 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1341 select DEBUG_LOCK_ALLOC
1342 select DEBUG_SPINLOCK
1343 select DEBUG_MUTEXES if !PREEMPT_RT
1344 select DEBUG_RT_MUTEXES if PREEMPT_RT
1346 This feature enables slowpath testing for w/w mutex users by
1347 injecting additional -EDEADLK wound/backoff cases. Together with
1348 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1349 will test all possible w/w mutex interface abuse with the
1350 exception of simply not acquiring all the required locks.
1351 Note that this feature can introduce significant overhead, so
1352 it really should not be enabled in a production or distro kernel,
1353 even a debug kernel. If you are a driver writer, enable it. If
1354 you are a distro, do not.
1357 bool "RW Semaphore debugging: basic checks"
1358 depends on DEBUG_KERNEL
1360 This debugging feature allows mismatched rw semaphore locks
1361 and unlocks to be detected and reported.
1363 config DEBUG_LOCK_ALLOC
1364 bool "Lock debugging: detect incorrect freeing of live locks"
1365 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1366 select DEBUG_SPINLOCK
1367 select DEBUG_MUTEXES if !PREEMPT_RT
1368 select DEBUG_RT_MUTEXES if RT_MUTEXES
1371 This feature will check whether any held lock (spinlock, rwlock,
1372 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1373 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1374 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1375 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1376 held during task exit.
1380 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1385 config LOCKDEP_SMALL
1389 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1390 depends on LOCKDEP && !LOCKDEP_SMALL
1394 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1396 config LOCKDEP_CHAINS_BITS
1397 int "Bitsize for MAX_LOCKDEP_CHAINS"
1398 depends on LOCKDEP && !LOCKDEP_SMALL
1402 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1404 config LOCKDEP_STACK_TRACE_BITS
1405 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1406 depends on LOCKDEP && !LOCKDEP_SMALL
1410 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1412 config LOCKDEP_STACK_TRACE_HASH_BITS
1413 int "Bitsize for STACK_TRACE_HASH_SIZE"
1414 depends on LOCKDEP && !LOCKDEP_SMALL
1418 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1420 config LOCKDEP_CIRCULAR_QUEUE_BITS
1421 int "Bitsize for elements in circular_queue struct"
1426 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1428 config DEBUG_LOCKDEP
1429 bool "Lock dependency engine debugging"
1430 depends on DEBUG_KERNEL && LOCKDEP
1431 select DEBUG_IRQFLAGS
1433 If you say Y here, the lock dependency engine will do
1434 additional runtime checks to debug itself, at the price
1435 of more runtime overhead.
1437 config DEBUG_ATOMIC_SLEEP
1438 bool "Sleep inside atomic section checking"
1439 select PREEMPT_COUNT
1440 depends on DEBUG_KERNEL
1441 depends on !ARCH_NO_PREEMPT
1443 If you say Y here, various routines which may sleep will become very
1444 noisy if they are called inside atomic sections: when a spinlock is
1445 held, inside an rcu read side critical section, inside preempt disabled
1446 sections, inside an interrupt, etc...
1448 config DEBUG_LOCKING_API_SELFTESTS
1449 bool "Locking API boot-time self-tests"
1450 depends on DEBUG_KERNEL
1452 Say Y here if you want the kernel to run a short self-test during
1453 bootup. The self-test checks whether common types of locking bugs
1454 are detected by debugging mechanisms or not. (if you disable
1455 lock debugging then those bugs won't be detected of course.)
1456 The following locking APIs are covered: spinlocks, rwlocks,
1459 config LOCK_TORTURE_TEST
1460 tristate "torture tests for locking"
1461 depends on DEBUG_KERNEL
1464 This option provides a kernel module that runs torture tests
1465 on kernel locking primitives. The kernel module may be built
1466 after the fact on the running kernel to be tested, if desired.
1468 Say Y here if you want kernel locking-primitive torture tests
1469 to be built into the kernel.
1470 Say M if you want these torture tests to build as a module.
1471 Say N if you are unsure.
1473 config WW_MUTEX_SELFTEST
1474 tristate "Wait/wound mutex selftests"
1476 This option provides a kernel module that runs tests on the
1477 on the struct ww_mutex locking API.
1479 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1480 with this test harness.
1482 Say M if you want these self tests to build as a module.
1483 Say N if you are unsure.
1485 config SCF_TORTURE_TEST
1486 tristate "torture tests for smp_call_function*()"
1487 depends on DEBUG_KERNEL
1490 This option provides a kernel module that runs torture tests
1491 on the smp_call_function() family of primitives. The kernel
1492 module may be built after the fact on the running kernel to
1493 be tested, if desired.
1495 config CSD_LOCK_WAIT_DEBUG
1496 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1497 depends on DEBUG_KERNEL
1501 This option enables debug prints when CPUs are slow to respond
1502 to the smp_call_function*() IPI wrappers. These debug prints
1503 include the IPI handler function currently executing (if any)
1504 and relevant stack traces.
1506 endmenu # lock debugging
1508 config TRACE_IRQFLAGS
1509 depends on TRACE_IRQFLAGS_SUPPORT
1512 Enables hooks to interrupt enabling and disabling for
1513 either tracing or lock debugging.
1515 config TRACE_IRQFLAGS_NMI
1517 depends on TRACE_IRQFLAGS
1518 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1520 config DEBUG_IRQFLAGS
1521 bool "Debug IRQ flag manipulation"
1523 Enables checks for potentially unsafe enabling or disabling of
1524 interrupts, such as calling raw_local_irq_restore() when interrupts
1528 bool "Stack backtrace support"
1529 depends on STACKTRACE_SUPPORT
1531 This option causes the kernel to create a /proc/pid/stack for
1532 every process, showing its current stack trace.
1533 It is also used by various kernel debugging features that require
1534 stack trace generation.
1536 config WARN_ALL_UNSEEDED_RANDOM
1537 bool "Warn for all uses of unseeded randomness"
1540 Some parts of the kernel contain bugs relating to their use of
1541 cryptographically secure random numbers before it's actually possible
1542 to generate those numbers securely. This setting ensures that these
1543 flaws don't go unnoticed, by enabling a message, should this ever
1544 occur. This will allow people with obscure setups to know when things
1545 are going wrong, so that they might contact developers about fixing
1548 Unfortunately, on some models of some architectures getting
1549 a fully seeded CRNG is extremely difficult, and so this can
1550 result in dmesg getting spammed for a surprisingly long
1551 time. This is really bad from a security perspective, and
1552 so architecture maintainers really need to do what they can
1553 to get the CRNG seeded sooner after the system is booted.
1554 However, since users cannot do anything actionable to
1555 address this, by default this option is disabled.
1557 Say Y here if you want to receive warnings for all uses of
1558 unseeded randomness. This will be of use primarily for
1559 those developers interested in improving the security of
1560 Linux kernels running on their architecture (or
1563 config DEBUG_KOBJECT
1564 bool "kobject debugging"
1565 depends on DEBUG_KERNEL
1567 If you say Y here, some extra kobject debugging messages will be sent
1570 config DEBUG_KOBJECT_RELEASE
1571 bool "kobject release debugging"
1572 depends on DEBUG_OBJECTS_TIMERS
1574 kobjects are reference counted objects. This means that their
1575 last reference count put is not predictable, and the kobject can
1576 live on past the point at which a driver decides to drop its
1577 initial reference to the kobject gained on allocation. An
1578 example of this would be a struct device which has just been
1581 However, some buggy drivers assume that after such an operation,
1582 the memory backing the kobject can be immediately freed. This
1583 goes completely against the principles of a refcounted object.
1585 If you say Y here, the kernel will delay the release of kobjects
1586 on the last reference count to improve the visibility of this
1587 kind of kobject release bug.
1589 config HAVE_DEBUG_BUGVERBOSE
1592 menu "Debug kernel data structures"
1595 bool "Debug linked list manipulation"
1596 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1598 Enable this to turn on extended checks in the linked-list
1604 bool "Debug priority linked list manipulation"
1605 depends on DEBUG_KERNEL
1607 Enable this to turn on extended checks in the priority-ordered
1608 linked-list (plist) walking routines. This checks the entire
1609 list multiple times during each manipulation.
1614 bool "Debug SG table operations"
1615 depends on DEBUG_KERNEL
1617 Enable this to turn on checks on scatter-gather tables. This can
1618 help find problems with drivers that do not properly initialize
1623 config DEBUG_NOTIFIERS
1624 bool "Debug notifier call chains"
1625 depends on DEBUG_KERNEL
1627 Enable this to turn on sanity checking for notifier call chains.
1628 This is most useful for kernel developers to make sure that
1629 modules properly unregister themselves from notifier chains.
1630 This is a relatively cheap check but if you care about maximum
1633 config BUG_ON_DATA_CORRUPTION
1634 bool "Trigger a BUG when data corruption is detected"
1637 Select this option if the kernel should BUG when it encounters
1638 data corruption in kernel memory structures when they get checked
1643 config DEBUG_MAPLE_TREE
1644 bool "Debug maple trees"
1645 depends on DEBUG_KERNEL
1647 Enable maple tree debugging information and extra validations.
1653 config DEBUG_CREDENTIALS
1654 bool "Debug credential management"
1655 depends on DEBUG_KERNEL
1657 Enable this to turn on some debug checking for credential
1658 management. The additional code keeps track of the number of
1659 pointers from task_structs to any given cred struct, and checks to
1660 see that this number never exceeds the usage count of the cred
1663 Furthermore, if SELinux is enabled, this also checks that the
1664 security pointer in the cred struct is never seen to be invalid.
1668 source "kernel/rcu/Kconfig.debug"
1670 config DEBUG_WQ_FORCE_RR_CPU
1671 bool "Force round-robin CPU selection for unbound work items"
1672 depends on DEBUG_KERNEL
1675 Workqueue used to implicitly guarantee that work items queued
1676 without explicit CPU specified are put on the local CPU. This
1677 guarantee is no longer true and while local CPU is still
1678 preferred work items may be put on foreign CPUs. Kernel
1679 parameter "workqueue.debug_force_rr_cpu" is added to force
1680 round-robin CPU selection to flush out usages which depend on the
1681 now broken guarantee. This config option enables the debug
1682 feature by default. When enabled, memory and cache locality will
1685 config CPU_HOTPLUG_STATE_CONTROL
1686 bool "Enable CPU hotplug state control"
1687 depends on DEBUG_KERNEL
1688 depends on HOTPLUG_CPU
1691 Allows to write steps between "offline" and "online" to the CPUs
1692 sysfs target file so states can be stepped granular. This is a debug
1693 option for now as the hotplug machinery cannot be stopped and
1694 restarted at arbitrary points yet.
1696 Say N if your are unsure.
1699 bool "Latency measuring infrastructure"
1700 depends on DEBUG_KERNEL
1701 depends on STACKTRACE_SUPPORT
1703 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1709 Enable this option if you want to use the LatencyTOP tool
1710 to find out which userspace is blocking on what kernel operations.
1712 source "kernel/trace/Kconfig"
1714 config PROVIDE_OHCI1394_DMA_INIT
1715 bool "Remote debugging over FireWire early on boot"
1716 depends on PCI && X86
1718 If you want to debug problems which hang or crash the kernel early
1719 on boot and the crashing machine has a FireWire port, you can use
1720 this feature to remotely access the memory of the crashed machine
1721 over FireWire. This employs remote DMA as part of the OHCI1394
1722 specification which is now the standard for FireWire controllers.
1724 With remote DMA, you can monitor the printk buffer remotely using
1725 firescope and access all memory below 4GB using fireproxy from gdb.
1726 Even controlling a kernel debugger is possible using remote DMA.
1730 If ohci1394_dma=early is used as boot parameter, it will initialize
1731 all OHCI1394 controllers which are found in the PCI config space.
1733 As all changes to the FireWire bus such as enabling and disabling
1734 devices cause a bus reset and thereby disable remote DMA for all
1735 devices, be sure to have the cable plugged and FireWire enabled on
1736 the debugging host before booting the debug target for debugging.
1738 This code (~1k) is freed after boot. By then, the firewire stack
1739 in charge of the OHCI-1394 controllers should be used instead.
1741 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1743 source "samples/Kconfig"
1745 config ARCH_HAS_DEVMEM_IS_ALLOWED
1748 config STRICT_DEVMEM
1749 bool "Filter access to /dev/mem"
1750 depends on MMU && DEVMEM
1751 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1752 default y if PPC || X86 || ARM64
1754 If this option is disabled, you allow userspace (root) access to all
1755 of memory, including kernel and userspace memory. Accidental
1756 access to this is obviously disastrous, but specific access can
1757 be used by people debugging the kernel. Note that with PAT support
1758 enabled, even in this case there are restrictions on /dev/mem
1759 use due to the cache aliasing requirements.
1761 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1762 file only allows userspace access to PCI space and the BIOS code and
1763 data regions. This is sufficient for dosemu and X and all common
1768 config IO_STRICT_DEVMEM
1769 bool "Filter I/O access to /dev/mem"
1770 depends on STRICT_DEVMEM
1772 If this option is disabled, you allow userspace (root) access to all
1773 io-memory regardless of whether a driver is actively using that
1774 range. Accidental access to this is obviously disastrous, but
1775 specific access can be used by people debugging kernel drivers.
1777 If this option is switched on, the /dev/mem file only allows
1778 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1779 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1780 if the driver using a given range cannot be disabled.
1784 menu "$(SRCARCH) Debugging"
1786 source "arch/$(SRCARCH)/Kconfig.debug"
1790 menu "Kernel Testing and Coverage"
1792 source "lib/kunit/Kconfig"
1794 config NOTIFIER_ERROR_INJECTION
1795 tristate "Notifier error injection"
1796 depends on DEBUG_KERNEL
1799 This option provides the ability to inject artificial errors to
1800 specified notifier chain callbacks. It is useful to test the error
1801 handling of notifier call chain failures.
1805 config PM_NOTIFIER_ERROR_INJECT
1806 tristate "PM notifier error injection module"
1807 depends on PM && NOTIFIER_ERROR_INJECTION
1808 default m if PM_DEBUG
1810 This option provides the ability to inject artificial errors to
1811 PM notifier chain callbacks. It is controlled through debugfs
1812 interface /sys/kernel/debug/notifier-error-inject/pm
1814 If the notifier call chain should be failed with some events
1815 notified, write the error code to "actions/<notifier event>/error".
1817 Example: Inject PM suspend error (-12 = -ENOMEM)
1819 # cd /sys/kernel/debug/notifier-error-inject/pm/
1820 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1821 # echo mem > /sys/power/state
1822 bash: echo: write error: Cannot allocate memory
1824 To compile this code as a module, choose M here: the module will
1825 be called pm-notifier-error-inject.
1829 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1830 tristate "OF reconfig notifier error injection module"
1831 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1833 This option provides the ability to inject artificial errors to
1834 OF reconfig notifier chain callbacks. It is controlled
1835 through debugfs interface under
1836 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1838 If the notifier call chain should be failed with some events
1839 notified, write the error code to "actions/<notifier event>/error".
1841 To compile this code as a module, choose M here: the module will
1842 be called of-reconfig-notifier-error-inject.
1846 config NETDEV_NOTIFIER_ERROR_INJECT
1847 tristate "Netdev notifier error injection module"
1848 depends on NET && NOTIFIER_ERROR_INJECTION
1850 This option provides the ability to inject artificial errors to
1851 netdevice notifier chain callbacks. It is controlled through debugfs
1852 interface /sys/kernel/debug/notifier-error-inject/netdev
1854 If the notifier call chain should be failed with some events
1855 notified, write the error code to "actions/<notifier event>/error".
1857 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1859 # cd /sys/kernel/debug/notifier-error-inject/netdev
1860 # echo -22 > actions/NETDEV_CHANGEMTU/error
1861 # ip link set eth0 mtu 1024
1862 RTNETLINK answers: Invalid argument
1864 To compile this code as a module, choose M here: the module will
1865 be called netdev-notifier-error-inject.
1869 config FUNCTION_ERROR_INJECTION
1871 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1873 config FAULT_INJECTION
1874 bool "Fault-injection framework"
1875 depends on DEBUG_KERNEL
1877 Provide fault-injection framework.
1878 For more details, see Documentation/fault-injection/.
1881 bool "Fault-injection capability for kmalloc"
1882 depends on FAULT_INJECTION
1883 depends on SLAB || SLUB
1885 Provide fault-injection capability for kmalloc.
1887 config FAIL_PAGE_ALLOC
1888 bool "Fault-injection capability for alloc_pages()"
1889 depends on FAULT_INJECTION
1891 Provide fault-injection capability for alloc_pages().
1893 config FAULT_INJECTION_USERCOPY
1894 bool "Fault injection capability for usercopy functions"
1895 depends on FAULT_INJECTION
1897 Provides fault-injection capability to inject failures
1898 in usercopy functions (copy_from_user(), get_user(), ...).
1900 config FAIL_MAKE_REQUEST
1901 bool "Fault-injection capability for disk IO"
1902 depends on FAULT_INJECTION && BLOCK
1904 Provide fault-injection capability for disk IO.
1906 config FAIL_IO_TIMEOUT
1907 bool "Fault-injection capability for faking disk interrupts"
1908 depends on FAULT_INJECTION && BLOCK
1910 Provide fault-injection capability on end IO handling. This
1911 will make the block layer "forget" an interrupt as configured,
1912 thus exercising the error handling.
1914 Only works with drivers that use the generic timeout handling,
1915 for others it won't do anything.
1918 bool "Fault-injection capability for futexes"
1920 depends on FAULT_INJECTION && FUTEX
1922 Provide fault-injection capability for futexes.
1924 config FAULT_INJECTION_DEBUG_FS
1925 bool "Debugfs entries for fault-injection capabilities"
1926 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1928 Enable configuration of fault-injection capabilities via debugfs.
1930 config FAIL_FUNCTION
1931 bool "Fault-injection capability for functions"
1932 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1934 Provide function-based fault-injection capability.
1935 This will allow you to override a specific function with a return
1936 with given return value. As a result, function caller will see
1937 an error value and have to handle it. This is useful to test the
1938 error handling in various subsystems.
1940 config FAIL_MMC_REQUEST
1941 bool "Fault-injection capability for MMC IO"
1942 depends on FAULT_INJECTION_DEBUG_FS && MMC
1944 Provide fault-injection capability for MMC IO.
1945 This will make the mmc core return data errors. This is
1946 useful to test the error handling in the mmc block device
1947 and to test how the mmc host driver handles retries from
1951 bool "Fault-injection capability for SunRPC"
1952 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
1954 Provide fault-injection capability for SunRPC and
1957 config FAULT_INJECTION_STACKTRACE_FILTER
1958 bool "stacktrace filter for fault-injection capabilities"
1959 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1962 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1964 Provide stacktrace filter for fault-injection capabilities
1966 config ARCH_HAS_KCOV
1969 An architecture should select this when it can successfully
1970 build and run with CONFIG_KCOV. This typically requires
1971 disabling instrumentation for some early boot code.
1973 config CC_HAS_SANCOV_TRACE_PC
1974 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1978 bool "Code coverage for fuzzing"
1979 depends on ARCH_HAS_KCOV
1980 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1981 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
1982 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
1984 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1985 select OBJTOOL if HAVE_NOINSTR_HACK
1987 KCOV exposes kernel code coverage information in a form suitable
1988 for coverage-guided fuzzing (randomized testing).
1990 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1991 different machines and across reboots. If you need stable PC values,
1992 disable RANDOMIZE_BASE.
1994 For more details, see Documentation/dev-tools/kcov.rst.
1996 config KCOV_ENABLE_COMPARISONS
1997 bool "Enable comparison operands collection by KCOV"
1999 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2001 KCOV also exposes operands of every comparison in the instrumented
2002 code along with operand sizes and PCs of the comparison instructions.
2003 These operands can be used by fuzzing engines to improve the quality
2004 of fuzzing coverage.
2006 config KCOV_INSTRUMENT_ALL
2007 bool "Instrument all code by default"
2011 If you are doing generic system call fuzzing (like e.g. syzkaller),
2012 then you will want to instrument the whole kernel and you should
2013 say y here. If you are doing more targeted fuzzing (like e.g.
2014 filesystem fuzzing with AFL) then you will want to enable coverage
2015 for more specific subsets of files, and should say n here.
2017 config KCOV_IRQ_AREA_SIZE
2018 hex "Size of interrupt coverage collection area in words"
2022 KCOV uses preallocated per-cpu areas to collect coverage from
2023 soft interrupts. This specifies the size of those areas in the
2024 number of unsigned long words.
2026 menuconfig RUNTIME_TESTING_MENU
2027 bool "Runtime Testing"
2030 if RUNTIME_TESTING_MENU
2033 tristate "Linux Kernel Dump Test Tool Module"
2036 This module enables testing of the different dumping mechanisms by
2037 inducing system failures at predefined crash points.
2038 If you don't need it: say N
2039 Choose M here to compile this code as a module. The module will be
2042 Documentation on how to use the module can be found in
2043 Documentation/fault-injection/provoke-crashes.rst
2045 config CPUMASK_KUNIT_TEST
2046 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2048 default KUNIT_ALL_TESTS
2050 Enable to turn on cpumask tests, running at boot or module load time.
2052 For more information on KUnit and unit tests in general, please refer
2053 to the KUnit documentation in Documentation/dev-tools/kunit/.
2057 config TEST_LIST_SORT
2058 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2060 default KUNIT_ALL_TESTS
2062 Enable this to turn on 'list_sort()' function test. This test is
2063 executed only once during system boot (so affects only boot time),
2064 or at module load time.
2068 config TEST_MIN_HEAP
2069 tristate "Min heap test"
2070 depends on DEBUG_KERNEL || m
2072 Enable this to turn on min heap function tests. This test is
2073 executed only once during system boot (so affects only boot time),
2074 or at module load time.
2079 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2081 default KUNIT_ALL_TESTS
2083 This option enables the self-test function of 'sort()' at boot,
2084 or at module load time.
2089 tristate "64bit/32bit division and modulo test"
2090 depends on DEBUG_KERNEL || m
2092 Enable this to turn on 'do_div()' function test. This test is
2093 executed only once during system boot (so affects only boot time),
2094 or at module load time.
2098 config KPROBES_SANITY_TEST
2099 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2100 depends on DEBUG_KERNEL
2103 default KUNIT_ALL_TESTS
2105 This option provides for testing basic kprobes functionality on
2106 boot. Samples of kprobe and kretprobe are inserted and
2107 verified for functionality.
2109 Say N if you are unsure.
2111 config FPROBE_SANITY_TEST
2112 bool "Self test for fprobe"
2113 depends on DEBUG_KERNEL
2117 This option will enable testing the fprobe when the system boot.
2118 A series of tests are made to verify that the fprobe is functioning
2121 Say N if you are unsure.
2123 config BACKTRACE_SELF_TEST
2124 tristate "Self test for the backtrace code"
2125 depends on DEBUG_KERNEL
2127 This option provides a kernel module that can be used to test
2128 the kernel stack backtrace code. This option is not useful
2129 for distributions or general kernels, but only for kernel
2130 developers working on architecture code.
2132 Note that if you want to also test saved backtraces, you will
2133 have to enable STACKTRACE as well.
2135 Say N if you are unsure.
2137 config TEST_REF_TRACKER
2138 tristate "Self test for reference tracker"
2139 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2142 This option provides a kernel module performing tests
2143 using reference tracker infrastructure.
2145 Say N if you are unsure.
2148 tristate "Red-Black tree test"
2149 depends on DEBUG_KERNEL
2151 A benchmark measuring the performance of the rbtree library.
2152 Also includes rbtree invariant checks.
2154 config REED_SOLOMON_TEST
2155 tristate "Reed-Solomon library test"
2156 depends on DEBUG_KERNEL || m
2158 select REED_SOLOMON_ENC16
2159 select REED_SOLOMON_DEC16
2161 This option enables the self-test function of rslib at boot,
2162 or at module load time.
2166 config INTERVAL_TREE_TEST
2167 tristate "Interval tree test"
2168 depends on DEBUG_KERNEL
2169 select INTERVAL_TREE
2171 A benchmark measuring the performance of the interval tree library
2174 tristate "Per cpu operations test"
2175 depends on m && DEBUG_KERNEL
2177 Enable this option to build test module which validates per-cpu
2182 config ATOMIC64_SELFTEST
2183 tristate "Perform an atomic64_t self-test"
2185 Enable this option to test the atomic64_t functions at boot or
2186 at module load time.
2190 config ASYNC_RAID6_TEST
2191 tristate "Self test for hardware accelerated raid6 recovery"
2192 depends on ASYNC_RAID6_RECOV
2195 This is a one-shot self test that permutes through the
2196 recovery of all the possible two disk failure scenarios for a
2197 N-disk array. Recovery is performed with the asynchronous
2198 raid6 recovery routines, and will optionally use an offload
2199 engine if one is available.
2204 tristate "Test functions located in the hexdump module at runtime"
2206 config STRING_SELFTEST
2207 tristate "Test string functions at runtime"
2209 config TEST_STRING_HELPERS
2210 tristate "Test functions located in the string_helpers module at runtime"
2213 tristate "Test strscpy*() family of functions at runtime"
2216 tristate "Test kstrto*() family of functions at runtime"
2219 tristate "Test printf() family of functions at runtime"
2222 tristate "Test scanf() family of functions at runtime"
2225 tristate "Test bitmap_*() family of functions at runtime"
2227 Enable this option to test the bitmap functions at boot.
2232 tristate "Test functions located in the uuid module at runtime"
2235 tristate "Test the XArray code at runtime"
2237 config TEST_RHASHTABLE
2238 tristate "Perform selftest on resizable hash table"
2240 Enable this option to test the rhashtable functions at boot.
2245 tristate "Perform selftest on siphash functions"
2247 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2248 functions on boot (or module load).
2250 This is intended to help people writing architecture-specific
2251 optimized versions. If unsure, say N.
2254 tristate "Perform selftest on IDA functions"
2257 tristate "Perform selftest on priority array manager"
2260 Enable this option to test priority array manager on boot
2265 config TEST_IRQ_TIMINGS
2266 bool "IRQ timings selftest"
2267 depends on IRQ_TIMINGS
2269 Enable this option to test the irq timings code on boot.
2274 tristate "Test module loading with 'hello world' module"
2277 This builds the "test_module" module that emits "Hello, world"
2278 on printk when loaded. It is designed to be used for basic
2279 evaluation of the module loading subsystem (for example when
2280 validating module verification). It lacks any extra dependencies,
2281 and will not normally be loaded by the system unless explicitly
2287 tristate "Test module for compilation of bitops operations"
2290 This builds the "test_bitops" module that is much like the
2291 TEST_LKM module except that it does a basic exercise of the
2292 set/clear_bit macros and get_count_order/long to make sure there are
2293 no compiler warnings from C=1 sparse checker or -Wextra
2294 compilations. It has no dependencies and doesn't run or load unless
2295 explicitly requested by name. for example: modprobe test_bitops.
2300 tristate "Test module for stress/performance analysis of vmalloc allocator"
2305 This builds the "test_vmalloc" module that should be used for
2306 stress and performance analysis. So, any new change for vmalloc
2307 subsystem can be evaluated from performance and stability point
2312 config TEST_USER_COPY
2313 tristate "Test user/kernel boundary protections"
2316 This builds the "test_user_copy" module that runs sanity checks
2317 on the copy_to/from_user infrastructure, making sure basic
2318 user/kernel boundary testing is working. If it fails to load,
2319 a regression has been detected in the user/kernel memory boundary
2325 tristate "Test BPF filter functionality"
2328 This builds the "test_bpf" module that runs various test vectors
2329 against the BPF interpreter or BPF JIT compiler depending on the
2330 current setting. This is in particular useful for BPF JIT compiler
2331 development, but also to run regression tests against changes in
2332 the interpreter code. It also enables test stubs for eBPF maps and
2333 verifier used by user space verifier testsuite.
2337 config TEST_BLACKHOLE_DEV
2338 tristate "Test blackhole netdev functionality"
2341 This builds the "test_blackhole_dev" module that validates the
2342 data path through this blackhole netdev.
2346 config FIND_BIT_BENCHMARK
2347 tristate "Test find_bit functions"
2349 This builds the "test_find_bit" module that measure find_*_bit()
2350 functions performance.
2354 config TEST_FIRMWARE
2355 tristate "Test firmware loading via userspace interface"
2356 depends on FW_LOADER
2358 This builds the "test_firmware" module that creates a userspace
2359 interface for testing firmware loading. This can be used to
2360 control the triggering of firmware loading without needing an
2361 actual firmware-using device. The contents can be rechecked by
2367 tristate "sysctl test driver"
2368 depends on PROC_SYSCTL
2370 This builds the "test_sysctl" module. This driver enables to test the
2371 proc sysctl interfaces available to drivers safely without affecting
2372 production knobs which might alter system functionality.
2376 config BITFIELD_KUNIT
2377 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2379 default KUNIT_ALL_TESTS
2381 Enable this option to test the bitfield functions at boot.
2383 KUnit tests run during boot and output the results to the debug log
2384 in TAP format (http://testanything.org/). Only useful for kernel devs
2385 running the KUnit test harness, and not intended for inclusion into a
2388 For more information on KUnit and unit tests in general please refer
2389 to the KUnit documentation in Documentation/dev-tools/kunit/.
2393 config HASH_KUNIT_TEST
2394 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2396 default KUNIT_ALL_TESTS
2398 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2399 integer (<linux/hash.h>) hash functions on boot.
2401 KUnit tests run during boot and output the results to the debug log
2402 in TAP format (https://testanything.org/). Only useful for kernel devs
2403 running the KUnit test harness, and not intended for inclusion into a
2406 For more information on KUnit and unit tests in general please refer
2407 to the KUnit documentation in Documentation/dev-tools/kunit/.
2409 This is intended to help people writing architecture-specific
2410 optimized versions. If unsure, say N.
2412 config RESOURCE_KUNIT_TEST
2413 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2415 default KUNIT_ALL_TESTS
2417 This builds the resource API unit test.
2418 Tests the logic of API provided by resource.c and ioport.h.
2419 For more information on KUnit and unit tests in general please refer
2420 to the KUnit documentation in Documentation/dev-tools/kunit/.
2424 config SYSCTL_KUNIT_TEST
2425 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2427 default KUNIT_ALL_TESTS
2429 This builds the proc sysctl unit test, which runs on boot.
2430 Tests the API contract and implementation correctness of sysctl.
2431 For more information on KUnit and unit tests in general please refer
2432 to the KUnit documentation in Documentation/dev-tools/kunit/.
2436 config LIST_KUNIT_TEST
2437 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2439 default KUNIT_ALL_TESTS
2441 This builds the linked list KUnit test suite.
2442 It tests that the API and basic functionality of the list_head type
2443 and associated macros.
2445 KUnit tests run during boot and output the results to the debug log
2446 in TAP format (https://testanything.org/). Only useful for kernel devs
2447 running the KUnit test harness, and not intended for inclusion into a
2450 For more information on KUnit and unit tests in general please refer
2451 to the KUnit documentation in Documentation/dev-tools/kunit/.
2455 config LINEAR_RANGES_TEST
2456 tristate "KUnit test for linear_ranges"
2458 select LINEAR_RANGES
2460 This builds the linear_ranges unit test, which runs on boot.
2461 Tests the linear_ranges logic correctness.
2462 For more information on KUnit and unit tests in general please refer
2463 to the KUnit documentation in Documentation/dev-tools/kunit/.
2467 config CMDLINE_KUNIT_TEST
2468 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2470 default KUNIT_ALL_TESTS
2472 This builds the cmdline API unit test.
2473 Tests the logic of API provided by cmdline.c.
2474 For more information on KUnit and unit tests in general please refer
2475 to the KUnit documentation in Documentation/dev-tools/kunit/.
2480 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2482 default KUNIT_ALL_TESTS
2484 This builds the bits unit test.
2485 Tests the logic of macros defined in bits.h.
2486 For more information on KUnit and unit tests in general please refer
2487 to the KUnit documentation in Documentation/dev-tools/kunit/.
2491 config SLUB_KUNIT_TEST
2492 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2493 depends on SLUB_DEBUG && KUNIT
2494 default KUNIT_ALL_TESTS
2496 This builds SLUB allocator unit test.
2497 Tests SLUB cache debugging functionality.
2498 For more information on KUnit and unit tests in general please refer
2499 to the KUnit documentation in Documentation/dev-tools/kunit/.
2503 config RATIONAL_KUNIT_TEST
2504 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2505 depends on KUNIT && RATIONAL
2506 default KUNIT_ALL_TESTS
2508 This builds the rational math unit test.
2509 For more information on KUnit and unit tests in general please refer
2510 to the KUnit documentation in Documentation/dev-tools/kunit/.
2514 config MEMCPY_KUNIT_TEST
2515 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2517 default KUNIT_ALL_TESTS
2519 Builds unit tests for memcpy(), memmove(), and memset() functions.
2520 For more information on KUnit and unit tests in general please refer
2521 to the KUnit documentation in Documentation/dev-tools/kunit/.
2525 config IS_SIGNED_TYPE_KUNIT_TEST
2526 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2528 default KUNIT_ALL_TESTS
2530 Builds unit tests for the is_signed_type() macro.
2532 For more information on KUnit and unit tests in general please refer
2533 to the KUnit documentation in Documentation/dev-tools/kunit/.
2537 config OVERFLOW_KUNIT_TEST
2538 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2540 default KUNIT_ALL_TESTS
2542 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2545 For more information on KUnit and unit tests in general please refer
2546 to the KUnit documentation in Documentation/dev-tools/kunit/.
2550 config STACKINIT_KUNIT_TEST
2551 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2553 default KUNIT_ALL_TESTS
2555 Test if the kernel is zero-initializing stack variables and
2556 padding. Coverage is controlled by compiler flags,
2557 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2558 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2559 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2561 config FORTIFY_KUNIT_TEST
2562 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2563 depends on KUNIT && FORTIFY_SOURCE
2564 default KUNIT_ALL_TESTS
2566 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2567 by the str*() and mem*() family of functions. For testing runtime
2568 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2570 config HW_BREAKPOINT_KUNIT_TEST
2571 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2572 depends on HAVE_HW_BREAKPOINT
2574 default KUNIT_ALL_TESTS
2576 Tests for hw_breakpoint constraints accounting.
2581 tristate "udelay test driver"
2583 This builds the "udelay_test" module that helps to make sure
2584 that udelay() is working properly.
2588 config TEST_STATIC_KEYS
2589 tristate "Test static keys"
2592 Test the static key interfaces.
2596 config TEST_DYNAMIC_DEBUG
2597 tristate "Test DYNAMIC_DEBUG"
2598 depends on DYNAMIC_DEBUG
2600 This module registers a tracer callback to count enabled
2601 pr_debugs in a 'do_debugging' function, then alters their
2602 enablements, calls the function, and compares counts.
2607 tristate "kmod stress tester"
2609 depends on NETDEVICES && NET_CORE && INET # for TUN
2611 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2617 Test the kernel's module loading mechanism: kmod. kmod implements
2618 support to load modules using the Linux kernel's usermode helper.
2619 This test provides a series of tests against kmod.
2621 Although technically you can either build test_kmod as a module or
2622 into the kernel we disallow building it into the kernel since
2623 it stress tests request_module() and this will very likely cause
2624 some issues by taking over precious threads available from other
2625 module load requests, ultimately this could be fatal.
2629 tools/testing/selftests/kmod/kmod.sh --help
2633 config TEST_DEBUG_VIRTUAL
2634 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2635 depends on DEBUG_VIRTUAL
2637 Test the kernel's ability to detect incorrect calls to
2638 virt_to_phys() done against the non-linear part of the
2639 kernel's virtual address map.
2643 config TEST_MEMCAT_P
2644 tristate "Test memcat_p() helper function"
2646 Test the memcat_p() helper for correctly merging two
2647 pointer arrays together.
2651 config TEST_LIVEPATCH
2652 tristate "Test livepatching"
2654 depends on DYNAMIC_DEBUG
2655 depends on LIVEPATCH
2658 Test kernel livepatching features for correctness. The tests will
2659 load test modules that will be livepatched in various scenarios.
2661 To run all the livepatching tests:
2663 make -C tools/testing/selftests TARGETS=livepatch run_tests
2665 Alternatively, individual tests may be invoked:
2667 tools/testing/selftests/livepatch/test-callbacks.sh
2668 tools/testing/selftests/livepatch/test-livepatch.sh
2669 tools/testing/selftests/livepatch/test-shadow-vars.sh
2674 tristate "Perform selftest on object aggreration manager"
2678 Enable this option to test object aggregation manager on boot
2682 tristate "Test heap/page initialization"
2684 Test if the kernel is zero-initializing heap and page allocations.
2685 This can be useful to test init_on_alloc and init_on_free features.
2690 tristate "Test HMM (Heterogeneous Memory Management)"
2691 depends on TRANSPARENT_HUGEPAGE
2692 depends on DEVICE_PRIVATE
2696 This is a pseudo device driver solely for testing HMM.
2697 Say M here if you want to build the HMM test module.
2698 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2702 config TEST_FREE_PAGES
2703 tristate "Test freeing pages"
2705 Test that a memory leak does not occur due to a race between
2706 freeing a block of pages and a speculative page reference.
2707 Loading this module is safe if your kernel has the bug fixed.
2708 If the bug is not fixed, it will leak gigabytes of memory and
2709 probably OOM your system.
2712 tristate "Test floating point operations in kernel space"
2713 depends on X86 && !KCOV_INSTRUMENT_ALL
2715 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2716 which will trigger a sequence of floating point operations. This is used
2717 for self-testing floating point control register setting in
2722 config TEST_CLOCKSOURCE_WATCHDOG
2723 tristate "Test clocksource watchdog in kernel space"
2724 depends on CLOCKSOURCE_WATCHDOG
2726 Enable this option to create a kernel module that will trigger
2727 a test of the clocksource watchdog. This module may be loaded
2728 via modprobe or insmod in which case it will run upon being
2729 loaded, or it may be built in, in which case it will run
2734 endif # RUNTIME_TESTING_MENU
2736 config ARCH_USE_MEMTEST
2739 An architecture should select this when it uses early_memtest()
2740 during boot process.
2744 depends on ARCH_USE_MEMTEST
2746 This option adds a kernel parameter 'memtest', which allows memtest
2747 to be set and executed.
2748 memtest=0, mean disabled; -- default
2749 memtest=1, mean do 1 test pattern;
2751 memtest=17, mean do 17 test patterns.
2752 If you are unsure how to answer this question, answer N.
2756 config HYPERV_TESTING
2757 bool "Microsoft Hyper-V driver testing"
2759 depends on HYPERV && DEBUG_FS
2761 Select this option to enable Hyper-V vmbus testing.
2763 endmenu # "Kernel Testing and Coverage"
2767 config RUST_DEBUG_ASSERTIONS
2768 bool "Debug assertions"
2771 Enables rustc's `-Cdebug-assertions` codegen option.
2773 This flag lets you turn `cfg(debug_assertions)` conditional
2774 compilation on or off. This can be used to enable extra debugging
2775 code in development but not in production. For example, it controls
2776 the behavior of the standard library's `debug_assert!` macro.
2778 Note that this will apply to all Rust code, including `core`.
2782 config RUST_OVERFLOW_CHECKS
2783 bool "Overflow checks"
2787 Enables rustc's `-Coverflow-checks` codegen option.
2789 This flag allows you to control the behavior of runtime integer
2790 overflow. When overflow-checks are enabled, a Rust panic will occur
2793 Note that this will apply to all Rust code, including `core`.
2799 source "Documentation/Kconfig"
2801 endmenu # Kernel hacking
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