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.
234 # Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
235 # some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
236 config AS_HAS_NON_CONST_LEB128
237 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
240 prompt "Debug information"
241 depends on DEBUG_KERNEL
243 Selecting something other than "None" results in a kernel image
244 that will include debugging info resulting in a larger kernel image.
245 This adds debug symbols to the kernel and modules (gcc -g), and
246 is needed if you intend to use kernel crashdump or binary object
247 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
249 Choose which version of DWARF debug info to emit. If unsure,
250 select "Toolchain default".
252 config DEBUG_INFO_NONE
253 bool "Disable debug information"
255 Do not build the kernel with debugging information, which will
256 result in a faster and smaller build.
258 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
259 bool "Rely on the toolchain's implicit default DWARF version"
261 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
263 The implicit default version of DWARF debug info produced by a
264 toolchain changes over time.
266 This can break consumers of the debug info that haven't upgraded to
267 support newer revisions, and prevent testing newer versions, but
268 those should be less common scenarios.
270 config DEBUG_INFO_DWARF4
271 bool "Generate DWARF Version 4 debuginfo"
273 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
275 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
276 if using clang without clang's integrated assembler, and gdb 7.0+.
278 If you have consumers of DWARF debug info that are not ready for
279 newer revisions of DWARF, you may wish to choose this or have your
282 config DEBUG_INFO_DWARF5
283 bool "Generate DWARF Version 5 debuginfo"
285 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
287 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
288 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
289 draft features until 7.0), and gdb 8.0+.
291 Changes to the structure of debug info in Version 5 allow for around
292 15-18% savings in resulting image and debug info section sizes as
293 compared to DWARF Version 4. DWARF Version 5 standardizes previous
294 extensions such as accelerators for symbol indexing and the format
295 for fission (.dwo/.dwp) files. Users may not want to select this
296 config if they rely on tooling that has not yet been updated to
297 support DWARF Version 5.
299 endchoice # "Debug information"
303 config DEBUG_INFO_REDUCED
304 bool "Reduce debugging information"
306 If you say Y here gcc is instructed to generate less debugging
307 information for structure types. This means that tools that
308 need full debugging information (like kgdb or systemtap) won't
309 be happy. But if you merely need debugging information to
310 resolve line numbers there is no loss. Advantage is that
311 build directory object sizes shrink dramatically over a full
312 DEBUG_INFO build and compile times are reduced too.
313 Only works with newer gcc versions.
316 prompt "Compressed Debug information"
318 Compress the resulting debug info. Results in smaller debug info sections,
319 but requires that consumers are able to decompress the results.
321 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
323 config DEBUG_INFO_COMPRESSED_NONE
324 bool "Don't compress debug information"
326 Don't compress debug info sections.
328 config DEBUG_INFO_COMPRESSED_ZLIB
329 bool "Compress debugging information with zlib"
330 depends on $(cc-option,-gz=zlib)
331 depends on $(ld-option,--compress-debug-sections=zlib)
333 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
334 5.0+, binutils 2.26+, and zlib.
336 Users of dpkg-deb via scripts/package/builddeb may find an increase in
337 size of their debug .deb packages with this config set, due to the
338 debug info being compressed with zlib, then the object files being
339 recompressed with a different compression scheme. But this is still
340 preferable to setting $KDEB_COMPRESS to "none" which would be even
343 config DEBUG_INFO_COMPRESSED_ZSTD
344 bool "Compress debugging information with zstd"
345 depends on $(cc-option,-gz=zstd)
346 depends on $(ld-option,--compress-debug-sections=zstd)
348 Compress the debug information using zstd. This may provide better
349 compression than zlib, for about the same time costs, but requires newer
350 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
353 endchoice # "Compressed Debug information"
355 config DEBUG_INFO_SPLIT
356 bool "Produce split debuginfo in .dwo files"
357 depends on $(cc-option,-gsplit-dwarf)
358 # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
360 # https://github.com/llvm/llvm-project/issues/56642
361 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
362 depends on !RISCV || GCC_VERSION >= 120000
364 Generate debug info into separate .dwo files. This significantly
365 reduces the build directory size for builds with DEBUG_INFO,
366 because it stores the information only once on disk in .dwo
367 files instead of multiple times in object files and executables.
368 In addition the debug information is also compressed.
370 Requires recent gcc (4.7+) and recent gdb/binutils.
371 Any tool that packages or reads debug information would need
372 to know about the .dwo files and include them.
373 Incompatible with older versions of ccache.
375 config DEBUG_INFO_BTF
376 bool "Generate BTF typeinfo"
377 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
378 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
379 depends on BPF_SYSCALL
380 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
381 # pahole uses elfutils, which does not have support for Hexagon relocations
384 Generate deduplicated BTF type information from DWARF debug info.
385 Turning this on expects presence of pahole tool, which will convert
386 DWARF type info into equivalent deduplicated BTF type info.
388 config PAHOLE_HAS_SPLIT_BTF
389 def_bool PAHOLE_VERSION >= 119
391 config PAHOLE_HAS_BTF_TAG
392 def_bool PAHOLE_VERSION >= 123
393 depends on CC_IS_CLANG
395 Decide whether pahole emits btf_tag attributes (btf_type_tag and
396 btf_decl_tag) or not. Currently only clang compiler implements
397 these attributes, so make the config depend on CC_IS_CLANG.
399 config PAHOLE_HAS_LANG_EXCLUDE
400 def_bool PAHOLE_VERSION >= 124
402 Support for the --lang_exclude flag which makes pahole exclude
403 compilation units from the supplied language. Used in Kbuild to
404 omit Rust CUs which are not supported in version 1.24 of pahole,
405 otherwise it would emit malformed kernel and module binaries when
406 using DEBUG_INFO_BTF_MODULES.
408 config DEBUG_INFO_BTF_MODULES
410 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
412 Generate compact split BTF type information for kernel modules.
414 config MODULE_ALLOW_BTF_MISMATCH
415 bool "Allow loading modules with non-matching BTF type info"
416 depends on DEBUG_INFO_BTF_MODULES
418 For modules whose split BTF does not match vmlinux, load without
419 BTF rather than refusing to load. The default behavior with
420 module BTF enabled is to reject modules with such mismatches;
421 this option will still load module BTF where possible but ignore
422 it when a mismatch is found.
425 bool "Provide GDB scripts for kernel debugging"
427 This creates the required links to GDB helper scripts in the
428 build directory. If you load vmlinux into gdb, the helper
429 scripts will be automatically imported by gdb as well, and
430 additional functions are available to analyze a Linux kernel
431 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
437 int "Warn for stack frames larger than"
440 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
441 default 2048 if PARISC
442 default 1536 if (!64BIT && XTENSA)
443 default 1280 if KASAN && !64BIT
444 default 1024 if !64BIT
445 default 2048 if 64BIT
447 Tell the compiler to warn at build time for stack frames larger than this.
448 Setting this too low will cause a lot of warnings.
449 Setting it to 0 disables the warning.
451 config STRIP_ASM_SYMS
452 bool "Strip assembler-generated symbols during link"
455 Strip internal assembler-generated symbols during a link (symbols
456 that look like '.Lxxx') so they don't pollute the output of
457 get_wchan() and suchlike.
460 bool "Generate readable assembler code"
461 depends on DEBUG_KERNEL
464 Disable some compiler optimizations that tend to generate human unreadable
465 assembler output. This may make the kernel slightly slower, but it helps
466 to keep kernel developers who have to stare a lot at assembler listings
469 config HEADERS_INSTALL
470 bool "Install uapi headers to usr/include"
473 This option will install uapi headers (headers exported to user-space)
474 into the usr/include directory for use during the kernel build.
475 This is unneeded for building the kernel itself, but needed for some
476 user-space program samples. It is also needed by some features such
477 as uapi header sanity checks.
479 config DEBUG_SECTION_MISMATCH
480 bool "Enable full Section mismatch analysis"
483 The section mismatch analysis checks if there are illegal
484 references from one section to another section.
485 During linktime or runtime, some sections are dropped;
486 any use of code/data previously in these sections would
487 most likely result in an oops.
488 In the code, functions and variables are annotated with
489 __init,, etc. (see the full list in include/linux/init.h),
490 which results in the code/data being placed in specific sections.
491 The section mismatch analysis is always performed after a full
492 kernel build, and enabling this option causes the following
493 additional step to occur:
494 - Add the option -fno-inline-functions-called-once to gcc commands.
495 When inlining a function annotated with __init in a non-init
496 function, we would lose the section information and thus
497 the analysis would not catch the illegal reference.
498 This option tells gcc to inline less (but it does result in
501 config SECTION_MISMATCH_WARN_ONLY
502 bool "Make section mismatch errors non-fatal"
505 If you say N here, the build process will fail if there are any
506 section mismatch, instead of just throwing warnings.
510 config DEBUG_FORCE_FUNCTION_ALIGN_64B
511 bool "Force all function address 64B aligned"
512 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
513 select FUNCTION_ALIGNMENT_64B
515 There are cases that a commit from one domain changes the function
516 address alignment of other domains, and cause magic performance
517 bump (regression or improvement). Enable this option will help to
518 verify if the bump is caused by function alignment changes, while
519 it will slightly increase the kernel size and affect icache usage.
521 It is mainly for debug and performance tuning use.
524 # Select this config option from the architecture Kconfig, if it
525 # is preferred to always offer frame pointers as a config
526 # option on the architecture (regardless of KERNEL_DEBUG):
528 config ARCH_WANT_FRAME_POINTERS
532 bool "Compile the kernel with frame pointers"
533 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
534 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
536 If you say Y here the resulting kernel image will be slightly
537 larger and slower, but it gives very useful debugging information
538 in case of kernel bugs. (precise oopses/stacktraces/warnings)
543 config STACK_VALIDATION
544 bool "Compile-time stack metadata validation"
545 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
549 Validate frame pointer rules at compile-time. This helps ensure that
550 runtime stack traces are more reliable.
552 For more information, see
553 tools/objtool/Documentation/objtool.txt.
555 config NOINSTR_VALIDATION
557 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
562 bool "Generate vmlinux.map file when linking"
565 Selecting this option will pass "-Map=vmlinux.map" to ld
566 when linking vmlinux. That file can be useful for verifying
567 and debugging magic section games, and for seeing which
568 pieces of code get eliminated with
569 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
571 config DEBUG_FORCE_WEAK_PER_CPU
572 bool "Force weak per-cpu definitions"
573 depends on DEBUG_KERNEL
575 s390 and alpha require percpu variables in modules to be
576 defined weak to work around addressing range issue which
577 puts the following two restrictions on percpu variable
580 1. percpu symbols must be unique whether static or not
581 2. percpu variables can't be defined inside a function
583 To ensure that generic code follows the above rules, this
584 option forces all percpu variables to be defined as weak.
586 endmenu # "Compiler options"
588 menu "Generic Kernel Debugging Instruments"
591 bool "Magic SysRq key"
594 If you say Y here, you will have some control over the system even
595 if the system crashes for example during kernel debugging (e.g., you
596 will be able to flush the buffer cache to disk, reboot the system
597 immediately or dump some status information). This is accomplished
598 by pressing various keys while holding SysRq (Alt+PrintScreen). It
599 also works on a serial console (on PC hardware at least), if you
600 send a BREAK and then within 5 seconds a command keypress. The
601 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
602 Don't say Y unless you really know what this hack does.
604 config MAGIC_SYSRQ_DEFAULT_ENABLE
605 hex "Enable magic SysRq key functions by default"
606 depends on MAGIC_SYSRQ
609 Specifies which SysRq key functions are enabled by default.
610 This may be set to 1 or 0 to enable or disable them all, or
611 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
613 config MAGIC_SYSRQ_SERIAL
614 bool "Enable magic SysRq key over serial"
615 depends on MAGIC_SYSRQ
618 Many embedded boards have a disconnected TTL level serial which can
619 generate some garbage that can lead to spurious false sysrq detects.
620 This option allows you to decide whether you want to enable the
623 config MAGIC_SYSRQ_SERIAL_SEQUENCE
624 string "Char sequence that enables magic SysRq over serial"
625 depends on MAGIC_SYSRQ_SERIAL
628 Specifies a sequence of characters that can follow BREAK to enable
629 SysRq on a serial console.
631 If unsure, leave an empty string and the option will not be enabled.
634 bool "Debug Filesystem"
636 debugfs is a virtual file system that kernel developers use to put
637 debugging files into. Enable this option to be able to read and
638 write to these files.
640 For detailed documentation on the debugfs API, see
641 Documentation/filesystems/.
646 prompt "Debugfs default access"
648 default DEBUG_FS_ALLOW_ALL
650 This selects the default access restrictions for debugfs.
651 It can be overridden with kernel command line option
652 debugfs=[on,no-mount,off]. The restrictions apply for API access
653 and filesystem registration.
655 config DEBUG_FS_ALLOW_ALL
658 No restrictions apply. Both API and filesystem registration
659 is on. This is the normal default operation.
661 config DEBUG_FS_DISALLOW_MOUNT
662 bool "Do not register debugfs as filesystem"
664 The API is open but filesystem is not loaded. Clients can still do
665 their work and read with debug tools that do not need
668 config DEBUG_FS_ALLOW_NONE
671 Access is off. Clients get -PERM when trying to create nodes in
672 debugfs tree and debugfs is not registered as a filesystem.
673 Client can then back-off or continue without debugfs access.
677 source "lib/Kconfig.kgdb"
678 source "lib/Kconfig.ubsan"
679 source "lib/Kconfig.kcsan"
683 menu "Networking Debugging"
685 source "net/Kconfig.debug"
687 endmenu # "Networking Debugging"
689 menu "Memory Debugging"
691 source "mm/Kconfig.debug"
694 bool "Debug object operations"
695 depends on DEBUG_KERNEL
697 If you say Y here, additional code will be inserted into the
698 kernel to track the life time of various objects and validate
699 the operations on those objects.
701 config DEBUG_OBJECTS_SELFTEST
702 bool "Debug objects selftest"
703 depends on DEBUG_OBJECTS
705 This enables the selftest of the object debug code.
707 config DEBUG_OBJECTS_FREE
708 bool "Debug objects in freed memory"
709 depends on DEBUG_OBJECTS
711 This enables checks whether a k/v free operation frees an area
712 which contains an object which has not been deactivated
713 properly. This can make kmalloc/kfree-intensive workloads
716 config DEBUG_OBJECTS_TIMERS
717 bool "Debug timer objects"
718 depends on DEBUG_OBJECTS
720 If you say Y here, additional code will be inserted into the
721 timer routines to track the life time of timer objects and
722 validate the timer operations.
724 config DEBUG_OBJECTS_WORK
725 bool "Debug work objects"
726 depends on DEBUG_OBJECTS
728 If you say Y here, additional code will be inserted into the
729 work queue routines to track the life time of work objects and
730 validate the work operations.
732 config DEBUG_OBJECTS_RCU_HEAD
733 bool "Debug RCU callbacks objects"
734 depends on DEBUG_OBJECTS
736 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
738 config DEBUG_OBJECTS_PERCPU_COUNTER
739 bool "Debug percpu counter objects"
740 depends on DEBUG_OBJECTS
742 If you say Y here, additional code will be inserted into the
743 percpu counter routines to track the life time of percpu counter
744 objects and validate the percpu counter operations.
746 config DEBUG_OBJECTS_ENABLE_DEFAULT
747 int "debug_objects bootup default value (0-1)"
750 depends on DEBUG_OBJECTS
752 Debug objects boot parameter default value
754 config SHRINKER_DEBUG
755 bool "Enable shrinker debugging support"
758 Say Y to enable the shrinker debugfs interface which provides
759 visibility into the kernel memory shrinkers subsystem.
760 Disable it to avoid an extra memory footprint.
762 config DEBUG_STACK_USAGE
763 bool "Stack utilization instrumentation"
764 depends on DEBUG_KERNEL
766 Enables the display of the minimum amount of free stack which each
767 task has ever had available in the sysrq-T and sysrq-P debug output.
768 Also emits a message to dmesg when a process exits if that process
769 used more stack space than previously exiting processes.
771 This option will slow down process creation somewhat.
773 config SCHED_STACK_END_CHECK
774 bool "Detect stack corruption on calls to schedule()"
775 depends on DEBUG_KERNEL
778 This option checks for a stack overrun on calls to schedule().
779 If the stack end location is found to be over written always panic as
780 the content of the corrupted region can no longer be trusted.
781 This is to ensure no erroneous behaviour occurs which could result in
782 data corruption or a sporadic crash at a later stage once the region
783 is examined. The runtime overhead introduced is minimal.
785 config ARCH_HAS_DEBUG_VM_PGTABLE
788 An architecture should select this when it can successfully
789 build and run DEBUG_VM_PGTABLE.
791 config DEBUG_VM_IRQSOFF
792 def_bool DEBUG_VM && !PREEMPT_RT
796 depends on DEBUG_KERNEL
798 Enable this to turn on extended checks in the virtual-memory system
799 that may impact performance.
803 config DEBUG_VM_SHOOT_LAZIES
804 bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
806 depends on MMU_LAZY_TLB_SHOOTDOWN
808 Enable additional IPIs that ensure lazy tlb mm references are removed
809 before the mm is freed.
813 config DEBUG_VM_MAPLE_TREE
814 bool "Debug VM maple trees"
816 select DEBUG_MAPLE_TREE
818 Enable VM maple tree debugging information and extra validations.
823 bool "Debug VM red-black trees"
826 Enable VM red-black tree debugging information and extra validations.
830 config DEBUG_VM_PGFLAGS
831 bool "Debug page-flags operations"
834 Enables extra validation on page flags operations.
838 config DEBUG_VM_PGTABLE
839 bool "Debug arch page table for semantics compliance"
841 depends on ARCH_HAS_DEBUG_VM_PGTABLE
842 default y if DEBUG_VM
844 This option provides a debug method which can be used to test
845 architecture page table helper functions on various platforms in
846 verifying if they comply with expected generic MM semantics. This
847 will help architecture code in making sure that any changes or
848 new additions of these helpers still conform to expected
849 semantics of the generic MM. Platforms will have to opt in for
850 this through ARCH_HAS_DEBUG_VM_PGTABLE.
854 config ARCH_HAS_DEBUG_VIRTUAL
858 bool "Debug VM translations"
859 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
861 Enable some costly sanity checks in virtual to page code. This can
862 catch mistakes with virt_to_page() and friends.
866 config DEBUG_NOMMU_REGIONS
867 bool "Debug the global anon/private NOMMU mapping region tree"
868 depends on DEBUG_KERNEL && !MMU
870 This option causes the global tree of anonymous and private mapping
871 regions to be regularly checked for invalid topology.
873 config DEBUG_MEMORY_INIT
874 bool "Debug memory initialisation" if EXPERT
877 Enable this for additional checks during memory initialisation.
878 The sanity checks verify aspects of the VM such as the memory model
879 and other information provided by the architecture. Verbose
880 information will be printed at KERN_DEBUG loglevel depending
881 on the mminit_loglevel= command-line option.
885 config MEMORY_NOTIFIER_ERROR_INJECT
886 tristate "Memory hotplug notifier error injection module"
887 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
889 This option provides the ability to inject artificial errors to
890 memory hotplug notifier chain callbacks. It is controlled through
891 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
893 If the notifier call chain should be failed with some events
894 notified, write the error code to "actions/<notifier event>/error".
896 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
898 # cd /sys/kernel/debug/notifier-error-inject/memory
899 # echo -12 > actions/MEM_GOING_OFFLINE/error
900 # echo offline > /sys/devices/system/memory/memoryXXX/state
901 bash: echo: write error: Cannot allocate memory
903 To compile this code as a module, choose M here: the module will
904 be called memory-notifier-error-inject.
908 config DEBUG_PER_CPU_MAPS
909 bool "Debug access to per_cpu maps"
910 depends on DEBUG_KERNEL
913 Say Y to verify that the per_cpu map being accessed has
914 been set up. This adds a fair amount of code to kernel memory
915 and decreases performance.
919 config DEBUG_KMAP_LOCAL
920 bool "Debug kmap_local temporary mappings"
921 depends on DEBUG_KERNEL && KMAP_LOCAL
923 This option enables additional error checking for the kmap_local
924 infrastructure. Disable for production use.
926 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
929 config DEBUG_KMAP_LOCAL_FORCE_MAP
930 bool "Enforce kmap_local temporary mappings"
931 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
933 select DEBUG_KMAP_LOCAL
935 This option enforces temporary mappings through the kmap_local
936 mechanism for non-highmem pages and on non-highmem systems.
937 Disable this for production systems!
940 bool "Highmem debugging"
941 depends on DEBUG_KERNEL && HIGHMEM
942 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
943 select DEBUG_KMAP_LOCAL
945 This option enables additional error checking for high memory
946 systems. Disable for production systems.
948 config HAVE_DEBUG_STACKOVERFLOW
951 config DEBUG_STACKOVERFLOW
952 bool "Check for stack overflows"
953 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
955 Say Y here if you want to check for overflows of kernel, IRQ
956 and exception stacks (if your architecture uses them). This
957 option will show detailed messages if free stack space drops
958 below a certain limit.
960 These kinds of bugs usually occur when call-chains in the
961 kernel get too deep, especially when interrupts are
964 Use this in cases where you see apparently random memory
965 corruption, especially if it appears in 'struct thread_info'
967 If in doubt, say "N".
969 source "lib/Kconfig.kasan"
970 source "lib/Kconfig.kfence"
971 source "lib/Kconfig.kmsan"
973 endmenu # "Memory Debugging"
976 bool "Debug shared IRQ handlers"
977 depends on DEBUG_KERNEL
979 Enable this to generate a spurious interrupt just before a shared
980 interrupt handler is deregistered (generating one when registering
981 is currently disabled). Drivers need to handle this correctly. Some
982 don't and need to be caught.
984 menu "Debug Oops, Lockups and Hangs"
989 Say Y here to enable the kernel to panic when it oopses. This
990 has the same effect as setting oops=panic on the kernel command
993 This feature is useful to ensure that the kernel does not do
994 anything erroneous after an oops which could result in data
995 corruption or other issues.
999 config PANIC_ON_OOPS_VALUE
1002 default 0 if !PANIC_ON_OOPS
1003 default 1 if PANIC_ON_OOPS
1005 config PANIC_TIMEOUT
1009 Set the timeout value (in seconds) until a reboot occurs when
1010 the kernel panics. If n = 0, then we wait forever. A timeout
1011 value n > 0 will wait n seconds before rebooting, while a timeout
1012 value n < 0 will reboot immediately.
1014 config LOCKUP_DETECTOR
1017 config SOFTLOCKUP_DETECTOR
1018 bool "Detect Soft Lockups"
1019 depends on DEBUG_KERNEL && !S390
1020 select LOCKUP_DETECTOR
1022 Say Y here to enable the kernel to act as a watchdog to detect
1025 Softlockups are bugs that cause the kernel to loop in kernel
1026 mode for more than 20 seconds, without giving other tasks a
1027 chance to run. The current stack trace is displayed upon
1028 detection and the system will stay locked up.
1030 config BOOTPARAM_SOFTLOCKUP_PANIC
1031 bool "Panic (Reboot) On Soft Lockups"
1032 depends on SOFTLOCKUP_DETECTOR
1034 Say Y here to enable the kernel to panic on "soft lockups",
1035 which are bugs that cause the kernel to loop in kernel
1036 mode for more than 20 seconds (configurable using the watchdog_thresh
1037 sysctl), without giving other tasks a chance to run.
1039 The panic can be used in combination with panic_timeout,
1040 to cause the system to reboot automatically after a
1041 lockup has been detected. This feature is useful for
1042 high-availability systems that have uptime guarantees and
1043 where a lockup must be resolved ASAP.
1047 config HAVE_HARDLOCKUP_DETECTOR_BUDDY
1053 # Global switch whether to build a hardlockup detector at all. It is available
1054 # only when the architecture supports at least one implementation. There are
1055 # two exceptions. The hardlockup detector is never enabled on:
1057 # s390: it reported many false positives there
1059 # sparc64: has a custom implementation which is not using the common
1060 # hardlockup command line options and sysctl interface.
1062 config HARDLOCKUP_DETECTOR
1063 bool "Detect Hard Lockups"
1064 depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
1065 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1066 imply HARDLOCKUP_DETECTOR_PERF
1067 imply HARDLOCKUP_DETECTOR_BUDDY
1068 imply HARDLOCKUP_DETECTOR_ARCH
1069 select LOCKUP_DETECTOR
1072 Say Y here to enable the kernel to act as a watchdog to detect
1075 Hardlockups are bugs that cause the CPU to loop in kernel mode
1076 for more than 10 seconds, without letting other interrupts have a
1077 chance to run. The current stack trace is displayed upon detection
1078 and the system will stay locked up.
1081 # Note that arch-specific variants are always preferred.
1083 config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1084 bool "Prefer the buddy CPU hardlockup detector"
1085 depends on HARDLOCKUP_DETECTOR
1086 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
1087 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1089 Say Y here to prefer the buddy hardlockup detector over the perf one.
1091 With the buddy detector, each CPU uses its softlockup hrtimer
1092 to check that the next CPU is processing hrtimer interrupts by
1093 verifying that a counter is increasing.
1095 This hardlockup detector is useful on systems that don't have
1096 an arch-specific hardlockup detector or if resources needed
1097 for the hardlockup detector are better used for other things.
1099 config HARDLOCKUP_DETECTOR_PERF
1101 depends on HARDLOCKUP_DETECTOR
1102 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
1103 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1104 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1106 config HARDLOCKUP_DETECTOR_BUDDY
1108 depends on HARDLOCKUP_DETECTOR
1109 depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1110 depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
1111 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1112 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1114 config HARDLOCKUP_DETECTOR_ARCH
1116 depends on HARDLOCKUP_DETECTOR
1117 depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1119 The arch-specific implementation of the hardlockup detector will
1123 # Both the "perf" and "buddy" hardlockup detectors count hrtimer
1124 # interrupts. This config enables functions managing this common code.
1126 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1128 select SOFTLOCKUP_DETECTOR
1131 # Enables a timestamp based low pass filter to compensate for perf based
1132 # hard lockup detection which runs too fast due to turbo modes.
1134 config HARDLOCKUP_CHECK_TIMESTAMP
1137 config BOOTPARAM_HARDLOCKUP_PANIC
1138 bool "Panic (Reboot) On Hard Lockups"
1139 depends on HARDLOCKUP_DETECTOR
1141 Say Y here to enable the kernel to panic on "hard lockups",
1142 which are bugs that cause the kernel to loop in kernel
1143 mode with interrupts disabled for more than 10 seconds (configurable
1144 using the watchdog_thresh sysctl).
1148 config DETECT_HUNG_TASK
1149 bool "Detect Hung Tasks"
1150 depends on DEBUG_KERNEL
1151 default SOFTLOCKUP_DETECTOR
1153 Say Y here to enable the kernel to detect "hung tasks",
1154 which are bugs that cause the task to be stuck in
1155 uninterruptible "D" state indefinitely.
1157 When a hung task is detected, the kernel will print the
1158 current stack trace (which you should report), but the
1159 task will stay in uninterruptible state. If lockdep is
1160 enabled then all held locks will also be reported. This
1161 feature has negligible overhead.
1163 config DEFAULT_HUNG_TASK_TIMEOUT
1164 int "Default timeout for hung task detection (in seconds)"
1165 depends on DETECT_HUNG_TASK
1168 This option controls the default timeout (in seconds) used
1169 to determine when a task has become non-responsive and should
1172 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1173 sysctl or by writing a value to
1174 /proc/sys/kernel/hung_task_timeout_secs.
1176 A timeout of 0 disables the check. The default is two minutes.
1177 Keeping the default should be fine in most cases.
1179 config BOOTPARAM_HUNG_TASK_PANIC
1180 bool "Panic (Reboot) On Hung Tasks"
1181 depends on DETECT_HUNG_TASK
1183 Say Y here to enable the kernel to panic on "hung tasks",
1184 which are bugs that cause the kernel to leave a task stuck
1185 in uninterruptible "D" state.
1187 The panic can be used in combination with panic_timeout,
1188 to cause the system to reboot automatically after a
1189 hung task has been detected. This feature is useful for
1190 high-availability systems that have uptime guarantees and
1191 where a hung tasks must be resolved ASAP.
1196 bool "Detect Workqueue Stalls"
1197 depends on DEBUG_KERNEL
1199 Say Y here to enable stall detection on workqueues. If a
1200 worker pool doesn't make forward progress on a pending work
1201 item for over a given amount of time, 30s by default, a
1202 warning message is printed along with dump of workqueue
1203 state. This can be configured through kernel parameter
1204 "workqueue.watchdog_thresh" and its sysfs counterpart.
1206 config WQ_CPU_INTENSIVE_REPORT
1207 bool "Report per-cpu work items which hog CPU for too long"
1208 depends on DEBUG_KERNEL
1210 Say Y here to enable reporting of concurrency-managed per-cpu work
1211 items that hog CPUs for longer than
1212 workqueue.cpu_intensive_thresh_us. Workqueue automatically
1213 detects and excludes them from concurrency management to prevent
1214 them from stalling other per-cpu work items. Occassional
1215 triggering may not necessarily indicate a problem. Repeated
1216 triggering likely indicates that the work item should be switched
1217 to use an unbound workqueue.
1220 tristate "Test module to generate lockups"
1223 This builds the "test_lockup" module that helps to make sure
1224 that watchdogs and lockup detectors are working properly.
1226 Depending on module parameters it could emulate soft or hard
1227 lockup, "hung task", or locking arbitrary lock for a long time.
1228 Also it could generate series of lockups with cooling-down periods.
1232 endmenu # "Debug lockups and hangs"
1234 menu "Scheduler Debugging"
1237 bool "Collect scheduler debugging info"
1238 depends on DEBUG_KERNEL && DEBUG_FS
1241 If you say Y here, the /sys/kernel/debug/sched file will be provided
1242 that can help debug the scheduler. The runtime overhead of this
1250 bool "Collect scheduler statistics"
1251 depends on DEBUG_KERNEL && PROC_FS
1254 If you say Y here, additional code will be inserted into the
1255 scheduler and related routines to collect statistics about
1256 scheduler behavior and provide them in /proc/schedstat. These
1257 stats may be useful for both tuning and debugging the scheduler
1258 If you aren't debugging the scheduler or trying to tune a specific
1259 application, you can say N to avoid the very slight overhead
1264 config DEBUG_TIMEKEEPING
1265 bool "Enable extra timekeeping sanity checking"
1267 This option will enable additional timekeeping sanity checks
1268 which may be helpful when diagnosing issues where timekeeping
1269 problems are suspected.
1271 This may include checks in the timekeeping hotpaths, so this
1272 option may have a (very small) performance impact to some
1277 config DEBUG_PREEMPT
1278 bool "Debug preemptible kernel"
1279 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1281 If you say Y here then the kernel will use a debug variant of the
1282 commonly used smp_processor_id() function and will print warnings
1283 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1284 will detect preemption count underflows.
1286 This option has potential to introduce high runtime overhead,
1287 depending on workload as it triggers debugging routines for each
1288 this_cpu operation. It should only be used for debugging purposes.
1290 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1292 config LOCK_DEBUGGING_SUPPORT
1294 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1297 config PROVE_LOCKING
1298 bool "Lock debugging: prove locking correctness"
1299 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1301 select DEBUG_SPINLOCK
1302 select DEBUG_MUTEXES if !PREEMPT_RT
1303 select DEBUG_RT_MUTEXES if RT_MUTEXES
1305 select DEBUG_WW_MUTEX_SLOWPATH
1306 select DEBUG_LOCK_ALLOC
1307 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1308 select TRACE_IRQFLAGS
1311 This feature enables the kernel to prove that all locking
1312 that occurs in the kernel runtime is mathematically
1313 correct: that under no circumstance could an arbitrary (and
1314 not yet triggered) combination of observed locking
1315 sequences (on an arbitrary number of CPUs, running an
1316 arbitrary number of tasks and interrupt contexts) cause a
1319 In short, this feature enables the kernel to report locking
1320 related deadlocks before they actually occur.
1322 The proof does not depend on how hard and complex a
1323 deadlock scenario would be to trigger: how many
1324 participant CPUs, tasks and irq-contexts would be needed
1325 for it to trigger. The proof also does not depend on
1326 timing: if a race and a resulting deadlock is possible
1327 theoretically (no matter how unlikely the race scenario
1328 is), it will be proven so and will immediately be
1329 reported by the kernel (once the event is observed that
1330 makes the deadlock theoretically possible).
1332 If a deadlock is impossible (i.e. the locking rules, as
1333 observed by the kernel, are mathematically correct), the
1334 kernel reports nothing.
1336 NOTE: this feature can also be enabled for rwlocks, mutexes
1337 and rwsems - in which case all dependencies between these
1338 different locking variants are observed and mapped too, and
1339 the proof of observed correctness is also maintained for an
1340 arbitrary combination of these separate locking variants.
1342 For more details, see Documentation/locking/lockdep-design.rst.
1344 config PROVE_RAW_LOCK_NESTING
1345 bool "Enable raw_spinlock - spinlock nesting checks"
1346 depends on PROVE_LOCKING
1349 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1350 that the lock nesting rules for PREEMPT_RT enabled kernels are
1353 NOTE: There are known nesting problems. So if you enable this
1354 option expect lockdep splats until these problems have been fully
1355 addressed which is work in progress. This config switch allows to
1356 identify and analyze these problems. It will be removed and the
1357 check permanently enabled once the main issues have been fixed.
1359 If unsure, select N.
1362 bool "Lock usage statistics"
1363 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1365 select DEBUG_SPINLOCK
1366 select DEBUG_MUTEXES if !PREEMPT_RT
1367 select DEBUG_RT_MUTEXES if RT_MUTEXES
1368 select DEBUG_LOCK_ALLOC
1371 This feature enables tracking lock contention points
1373 For more details, see Documentation/locking/lockstat.rst
1375 This also enables lock events required by "perf lock",
1377 If you want to use "perf lock", you also need to turn on
1378 CONFIG_EVENT_TRACING.
1380 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1381 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1383 config DEBUG_RT_MUTEXES
1384 bool "RT Mutex debugging, deadlock detection"
1385 depends on DEBUG_KERNEL && RT_MUTEXES
1387 This allows rt mutex semantics violations and rt mutex related
1388 deadlocks (lockups) to be detected and reported automatically.
1390 config DEBUG_SPINLOCK
1391 bool "Spinlock and rw-lock debugging: basic checks"
1392 depends on DEBUG_KERNEL
1393 select UNINLINE_SPIN_UNLOCK
1395 Say Y here and build SMP to catch missing spinlock initialization
1396 and certain other kinds of spinlock errors commonly made. This is
1397 best used in conjunction with the NMI watchdog so that spinlock
1398 deadlocks are also debuggable.
1400 config DEBUG_MUTEXES
1401 bool "Mutex debugging: basic checks"
1402 depends on DEBUG_KERNEL && !PREEMPT_RT
1404 This feature allows mutex semantics violations to be detected and
1407 config DEBUG_WW_MUTEX_SLOWPATH
1408 bool "Wait/wound mutex debugging: Slowpath testing"
1409 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1410 select DEBUG_LOCK_ALLOC
1411 select DEBUG_SPINLOCK
1412 select DEBUG_MUTEXES if !PREEMPT_RT
1413 select DEBUG_RT_MUTEXES if PREEMPT_RT
1415 This feature enables slowpath testing for w/w mutex users by
1416 injecting additional -EDEADLK wound/backoff cases. Together with
1417 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1418 will test all possible w/w mutex interface abuse with the
1419 exception of simply not acquiring all the required locks.
1420 Note that this feature can introduce significant overhead, so
1421 it really should not be enabled in a production or distro kernel,
1422 even a debug kernel. If you are a driver writer, enable it. If
1423 you are a distro, do not.
1426 bool "RW Semaphore debugging: basic checks"
1427 depends on DEBUG_KERNEL
1429 This debugging feature allows mismatched rw semaphore locks
1430 and unlocks to be detected and reported.
1432 config DEBUG_LOCK_ALLOC
1433 bool "Lock debugging: detect incorrect freeing of live locks"
1434 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1435 select DEBUG_SPINLOCK
1436 select DEBUG_MUTEXES if !PREEMPT_RT
1437 select DEBUG_RT_MUTEXES if RT_MUTEXES
1440 This feature will check whether any held lock (spinlock, rwlock,
1441 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1442 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1443 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1444 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1445 held during task exit.
1449 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1454 config LOCKDEP_SMALL
1458 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1459 depends on LOCKDEP && !LOCKDEP_SMALL
1463 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1465 config LOCKDEP_CHAINS_BITS
1466 int "Bitsize for MAX_LOCKDEP_CHAINS"
1467 depends on LOCKDEP && !LOCKDEP_SMALL
1471 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1473 config LOCKDEP_STACK_TRACE_BITS
1474 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1475 depends on LOCKDEP && !LOCKDEP_SMALL
1479 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1481 config LOCKDEP_STACK_TRACE_HASH_BITS
1482 int "Bitsize for STACK_TRACE_HASH_SIZE"
1483 depends on LOCKDEP && !LOCKDEP_SMALL
1487 Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1489 config LOCKDEP_CIRCULAR_QUEUE_BITS
1490 int "Bitsize for elements in circular_queue struct"
1495 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1497 config DEBUG_LOCKDEP
1498 bool "Lock dependency engine debugging"
1499 depends on DEBUG_KERNEL && LOCKDEP
1500 select DEBUG_IRQFLAGS
1502 If you say Y here, the lock dependency engine will do
1503 additional runtime checks to debug itself, at the price
1504 of more runtime overhead.
1506 config DEBUG_ATOMIC_SLEEP
1507 bool "Sleep inside atomic section checking"
1508 select PREEMPT_COUNT
1509 depends on DEBUG_KERNEL
1510 depends on !ARCH_NO_PREEMPT
1512 If you say Y here, various routines which may sleep will become very
1513 noisy if they are called inside atomic sections: when a spinlock is
1514 held, inside an rcu read side critical section, inside preempt disabled
1515 sections, inside an interrupt, etc...
1517 config DEBUG_LOCKING_API_SELFTESTS
1518 bool "Locking API boot-time self-tests"
1519 depends on DEBUG_KERNEL
1521 Say Y here if you want the kernel to run a short self-test during
1522 bootup. The self-test checks whether common types of locking bugs
1523 are detected by debugging mechanisms or not. (if you disable
1524 lock debugging then those bugs won't be detected of course.)
1525 The following locking APIs are covered: spinlocks, rwlocks,
1528 config LOCK_TORTURE_TEST
1529 tristate "torture tests for locking"
1530 depends on DEBUG_KERNEL
1533 This option provides a kernel module that runs torture tests
1534 on kernel locking primitives. The kernel module may be built
1535 after the fact on the running kernel to be tested, if desired.
1537 Say Y here if you want kernel locking-primitive torture tests
1538 to be built into the kernel.
1539 Say M if you want these torture tests to build as a module.
1540 Say N if you are unsure.
1542 config WW_MUTEX_SELFTEST
1543 tristate "Wait/wound mutex selftests"
1545 This option provides a kernel module that runs tests on the
1546 on the struct ww_mutex locking API.
1548 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1549 with this test harness.
1551 Say M if you want these self tests to build as a module.
1552 Say N if you are unsure.
1554 config SCF_TORTURE_TEST
1555 tristate "torture tests for smp_call_function*()"
1556 depends on DEBUG_KERNEL
1559 This option provides a kernel module that runs torture tests
1560 on the smp_call_function() family of primitives. The kernel
1561 module may be built after the fact on the running kernel to
1562 be tested, if desired.
1564 config CSD_LOCK_WAIT_DEBUG
1565 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1566 depends on DEBUG_KERNEL
1570 This option enables debug prints when CPUs are slow to respond
1571 to the smp_call_function*() IPI wrappers. These debug prints
1572 include the IPI handler function currently executing (if any)
1573 and relevant stack traces.
1575 config CSD_LOCK_WAIT_DEBUG_DEFAULT
1576 bool "Default csd_lock_wait() debugging on at boot time"
1577 depends on CSD_LOCK_WAIT_DEBUG
1581 This option causes the csdlock_debug= kernel boot parameter to
1582 default to 1 (basic debugging) instead of 0 (no debugging).
1584 endmenu # lock debugging
1586 config TRACE_IRQFLAGS
1587 depends on TRACE_IRQFLAGS_SUPPORT
1590 Enables hooks to interrupt enabling and disabling for
1591 either tracing or lock debugging.
1593 config TRACE_IRQFLAGS_NMI
1595 depends on TRACE_IRQFLAGS
1596 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1598 config NMI_CHECK_CPU
1599 bool "Debugging for CPUs failing to respond to backtrace requests"
1600 depends on DEBUG_KERNEL
1604 Enables debug prints when a CPU fails to respond to a given
1605 backtrace NMI. These prints provide some reasons why a CPU
1606 might legitimately be failing to respond, for example, if it
1607 is offline of if ignore_nmis is set.
1609 config DEBUG_IRQFLAGS
1610 bool "Debug IRQ flag manipulation"
1612 Enables checks for potentially unsafe enabling or disabling of
1613 interrupts, such as calling raw_local_irq_restore() when interrupts
1617 bool "Stack backtrace support"
1618 depends on STACKTRACE_SUPPORT
1620 This option causes the kernel to create a /proc/pid/stack for
1621 every process, showing its current stack trace.
1622 It is also used by various kernel debugging features that require
1623 stack trace generation.
1625 config WARN_ALL_UNSEEDED_RANDOM
1626 bool "Warn for all uses of unseeded randomness"
1629 Some parts of the kernel contain bugs relating to their use of
1630 cryptographically secure random numbers before it's actually possible
1631 to generate those numbers securely. This setting ensures that these
1632 flaws don't go unnoticed, by enabling a message, should this ever
1633 occur. This will allow people with obscure setups to know when things
1634 are going wrong, so that they might contact developers about fixing
1637 Unfortunately, on some models of some architectures getting
1638 a fully seeded CRNG is extremely difficult, and so this can
1639 result in dmesg getting spammed for a surprisingly long
1640 time. This is really bad from a security perspective, and
1641 so architecture maintainers really need to do what they can
1642 to get the CRNG seeded sooner after the system is booted.
1643 However, since users cannot do anything actionable to
1644 address this, by default this option is disabled.
1646 Say Y here if you want to receive warnings for all uses of
1647 unseeded randomness. This will be of use primarily for
1648 those developers interested in improving the security of
1649 Linux kernels running on their architecture (or
1652 config DEBUG_KOBJECT
1653 bool "kobject debugging"
1654 depends on DEBUG_KERNEL
1656 If you say Y here, some extra kobject debugging messages will be sent
1659 config DEBUG_KOBJECT_RELEASE
1660 bool "kobject release debugging"
1661 depends on DEBUG_OBJECTS_TIMERS
1663 kobjects are reference counted objects. This means that their
1664 last reference count put is not predictable, and the kobject can
1665 live on past the point at which a driver decides to drop its
1666 initial reference to the kobject gained on allocation. An
1667 example of this would be a struct device which has just been
1670 However, some buggy drivers assume that after such an operation,
1671 the memory backing the kobject can be immediately freed. This
1672 goes completely against the principles of a refcounted object.
1674 If you say Y here, the kernel will delay the release of kobjects
1675 on the last reference count to improve the visibility of this
1676 kind of kobject release bug.
1678 config HAVE_DEBUG_BUGVERBOSE
1681 menu "Debug kernel data structures"
1684 bool "Debug linked list manipulation"
1685 depends on DEBUG_KERNEL
1686 select LIST_HARDENED
1688 Enable this to turn on extended checks in the linked-list walking
1691 This option trades better quality error reports for performance, and
1692 is more suitable for kernel debugging. If you care about performance,
1693 you should only enable CONFIG_LIST_HARDENED instead.
1698 bool "Debug priority linked list manipulation"
1699 depends on DEBUG_KERNEL
1701 Enable this to turn on extended checks in the priority-ordered
1702 linked-list (plist) walking routines. This checks the entire
1703 list multiple times during each manipulation.
1708 bool "Debug SG table operations"
1709 depends on DEBUG_KERNEL
1711 Enable this to turn on checks on scatter-gather tables. This can
1712 help find problems with drivers that do not properly initialize
1717 config DEBUG_NOTIFIERS
1718 bool "Debug notifier call chains"
1719 depends on DEBUG_KERNEL
1721 Enable this to turn on sanity checking for notifier call chains.
1722 This is most useful for kernel developers to make sure that
1723 modules properly unregister themselves from notifier chains.
1724 This is a relatively cheap check but if you care about maximum
1727 config DEBUG_CLOSURES
1728 bool "Debug closures (bcache async widgits)"
1732 Keeps all active closures in a linked list and provides a debugfs
1733 interface to list them, which makes it possible to see asynchronous
1734 operations that get stuck.
1736 config DEBUG_MAPLE_TREE
1737 bool "Debug maple trees"
1738 depends on DEBUG_KERNEL
1740 Enable maple tree debugging information and extra validations.
1746 source "kernel/rcu/Kconfig.debug"
1748 config DEBUG_WQ_FORCE_RR_CPU
1749 bool "Force round-robin CPU selection for unbound work items"
1750 depends on DEBUG_KERNEL
1753 Workqueue used to implicitly guarantee that work items queued
1754 without explicit CPU specified are put on the local CPU. This
1755 guarantee is no longer true and while local CPU is still
1756 preferred work items may be put on foreign CPUs. Kernel
1757 parameter "workqueue.debug_force_rr_cpu" is added to force
1758 round-robin CPU selection to flush out usages which depend on the
1759 now broken guarantee. This config option enables the debug
1760 feature by default. When enabled, memory and cache locality will
1763 config CPU_HOTPLUG_STATE_CONTROL
1764 bool "Enable CPU hotplug state control"
1765 depends on DEBUG_KERNEL
1766 depends on HOTPLUG_CPU
1769 Allows to write steps between "offline" and "online" to the CPUs
1770 sysfs target file so states can be stepped granular. This is a debug
1771 option for now as the hotplug machinery cannot be stopped and
1772 restarted at arbitrary points yet.
1774 Say N if your are unsure.
1777 bool "Latency measuring infrastructure"
1778 depends on DEBUG_KERNEL
1779 depends on STACKTRACE_SUPPORT
1781 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1787 Enable this option if you want to use the LatencyTOP tool
1788 to find out which userspace is blocking on what kernel operations.
1790 config DEBUG_CGROUP_REF
1791 bool "Disable inlining of cgroup css reference count functions"
1792 depends on DEBUG_KERNEL
1797 Force cgroup css reference count functions to not be inlined so
1798 that they can be kprobed for debugging.
1800 source "kernel/trace/Kconfig"
1802 config PROVIDE_OHCI1394_DMA_INIT
1803 bool "Remote debugging over FireWire early on boot"
1804 depends on PCI && X86
1806 If you want to debug problems which hang or crash the kernel early
1807 on boot and the crashing machine has a FireWire port, you can use
1808 this feature to remotely access the memory of the crashed machine
1809 over FireWire. This employs remote DMA as part of the OHCI1394
1810 specification which is now the standard for FireWire controllers.
1812 With remote DMA, you can monitor the printk buffer remotely using
1813 firescope and access all memory below 4GB using fireproxy from gdb.
1814 Even controlling a kernel debugger is possible using remote DMA.
1818 If ohci1394_dma=early is used as boot parameter, it will initialize
1819 all OHCI1394 controllers which are found in the PCI config space.
1821 As all changes to the FireWire bus such as enabling and disabling
1822 devices cause a bus reset and thereby disable remote DMA for all
1823 devices, be sure to have the cable plugged and FireWire enabled on
1824 the debugging host before booting the debug target for debugging.
1826 This code (~1k) is freed after boot. By then, the firewire stack
1827 in charge of the OHCI-1394 controllers should be used instead.
1829 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1831 source "samples/Kconfig"
1833 config ARCH_HAS_DEVMEM_IS_ALLOWED
1836 config STRICT_DEVMEM
1837 bool "Filter access to /dev/mem"
1838 depends on MMU && DEVMEM
1839 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1840 default y if PPC || X86 || ARM64
1842 If this option is disabled, you allow userspace (root) access to all
1843 of memory, including kernel and userspace memory. Accidental
1844 access to this is obviously disastrous, but specific access can
1845 be used by people debugging the kernel. Note that with PAT support
1846 enabled, even in this case there are restrictions on /dev/mem
1847 use due to the cache aliasing requirements.
1849 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1850 file only allows userspace access to PCI space and the BIOS code and
1851 data regions. This is sufficient for dosemu and X and all common
1856 config IO_STRICT_DEVMEM
1857 bool "Filter I/O access to /dev/mem"
1858 depends on STRICT_DEVMEM
1860 If this option is disabled, you allow userspace (root) access to all
1861 io-memory regardless of whether a driver is actively using that
1862 range. Accidental access to this is obviously disastrous, but
1863 specific access can be used by people debugging kernel drivers.
1865 If this option is switched on, the /dev/mem file only allows
1866 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1867 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1868 if the driver using a given range cannot be disabled.
1872 menu "$(SRCARCH) Debugging"
1874 source "arch/$(SRCARCH)/Kconfig.debug"
1878 menu "Kernel Testing and Coverage"
1880 source "lib/kunit/Kconfig"
1882 config NOTIFIER_ERROR_INJECTION
1883 tristate "Notifier error injection"
1884 depends on DEBUG_KERNEL
1887 This option provides the ability to inject artificial errors to
1888 specified notifier chain callbacks. It is useful to test the error
1889 handling of notifier call chain failures.
1893 config PM_NOTIFIER_ERROR_INJECT
1894 tristate "PM notifier error injection module"
1895 depends on PM && NOTIFIER_ERROR_INJECTION
1896 default m if PM_DEBUG
1898 This option provides the ability to inject artificial errors to
1899 PM notifier chain callbacks. It is controlled through debugfs
1900 interface /sys/kernel/debug/notifier-error-inject/pm
1902 If the notifier call chain should be failed with some events
1903 notified, write the error code to "actions/<notifier event>/error".
1905 Example: Inject PM suspend error (-12 = -ENOMEM)
1907 # cd /sys/kernel/debug/notifier-error-inject/pm/
1908 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1909 # echo mem > /sys/power/state
1910 bash: echo: write error: Cannot allocate memory
1912 To compile this code as a module, choose M here: the module will
1913 be called pm-notifier-error-inject.
1917 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1918 tristate "OF reconfig notifier error injection module"
1919 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1921 This option provides the ability to inject artificial errors to
1922 OF reconfig notifier chain callbacks. It is controlled
1923 through debugfs interface under
1924 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1926 If the notifier call chain should be failed with some events
1927 notified, write the error code to "actions/<notifier event>/error".
1929 To compile this code as a module, choose M here: the module will
1930 be called of-reconfig-notifier-error-inject.
1934 config NETDEV_NOTIFIER_ERROR_INJECT
1935 tristate "Netdev notifier error injection module"
1936 depends on NET && NOTIFIER_ERROR_INJECTION
1938 This option provides the ability to inject artificial errors to
1939 netdevice notifier chain callbacks. It is controlled through debugfs
1940 interface /sys/kernel/debug/notifier-error-inject/netdev
1942 If the notifier call chain should be failed with some events
1943 notified, write the error code to "actions/<notifier event>/error".
1945 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1947 # cd /sys/kernel/debug/notifier-error-inject/netdev
1948 # echo -22 > actions/NETDEV_CHANGEMTU/error
1949 # ip link set eth0 mtu 1024
1950 RTNETLINK answers: Invalid argument
1952 To compile this code as a module, choose M here: the module will
1953 be called netdev-notifier-error-inject.
1957 config FUNCTION_ERROR_INJECTION
1958 bool "Fault-injections of functions"
1959 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1961 Add fault injections into various functions that are annotated with
1962 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
1963 value of these functions. This is useful to test error paths of code.
1967 config FAULT_INJECTION
1968 bool "Fault-injection framework"
1969 depends on DEBUG_KERNEL
1971 Provide fault-injection framework.
1972 For more details, see Documentation/fault-injection/.
1975 bool "Fault-injection capability for kmalloc"
1976 depends on FAULT_INJECTION
1978 Provide fault-injection capability for kmalloc.
1980 config FAIL_PAGE_ALLOC
1981 bool "Fault-injection capability for alloc_pages()"
1982 depends on FAULT_INJECTION
1984 Provide fault-injection capability for alloc_pages().
1986 config FAULT_INJECTION_USERCOPY
1987 bool "Fault injection capability for usercopy functions"
1988 depends on FAULT_INJECTION
1990 Provides fault-injection capability to inject failures
1991 in usercopy functions (copy_from_user(), get_user(), ...).
1993 config FAIL_MAKE_REQUEST
1994 bool "Fault-injection capability for disk IO"
1995 depends on FAULT_INJECTION && BLOCK
1997 Provide fault-injection capability for disk IO.
1999 config FAIL_IO_TIMEOUT
2000 bool "Fault-injection capability for faking disk interrupts"
2001 depends on FAULT_INJECTION && BLOCK
2003 Provide fault-injection capability on end IO handling. This
2004 will make the block layer "forget" an interrupt as configured,
2005 thus exercising the error handling.
2007 Only works with drivers that use the generic timeout handling,
2008 for others it won't do anything.
2011 bool "Fault-injection capability for futexes"
2013 depends on FAULT_INJECTION && FUTEX
2015 Provide fault-injection capability for futexes.
2017 config FAULT_INJECTION_DEBUG_FS
2018 bool "Debugfs entries for fault-injection capabilities"
2019 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2021 Enable configuration of fault-injection capabilities via debugfs.
2023 config FAIL_FUNCTION
2024 bool "Fault-injection capability for functions"
2025 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2027 Provide function-based fault-injection capability.
2028 This will allow you to override a specific function with a return
2029 with given return value. As a result, function caller will see
2030 an error value and have to handle it. This is useful to test the
2031 error handling in various subsystems.
2033 config FAIL_MMC_REQUEST
2034 bool "Fault-injection capability for MMC IO"
2035 depends on FAULT_INJECTION_DEBUG_FS && MMC
2037 Provide fault-injection capability for MMC IO.
2038 This will make the mmc core return data errors. This is
2039 useful to test the error handling in the mmc block device
2040 and to test how the mmc host driver handles retries from
2044 bool "Fault-injection capability for SunRPC"
2045 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2047 Provide fault-injection capability for SunRPC and
2050 config FAULT_INJECTION_CONFIGFS
2051 bool "Configfs interface for fault-injection capabilities"
2052 depends on FAULT_INJECTION
2055 This option allows configfs-based drivers to dynamically configure
2056 fault-injection via configfs. Each parameter for driver-specific
2057 fault-injection can be made visible as a configfs attribute in a
2061 config FAULT_INJECTION_STACKTRACE_FILTER
2062 bool "stacktrace filter for fault-injection capabilities"
2063 depends on FAULT_INJECTION
2064 depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
2066 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2068 Provide stacktrace filter for fault-injection capabilities
2070 config ARCH_HAS_KCOV
2073 An architecture should select this when it can successfully
2074 build and run with CONFIG_KCOV. This typically requires
2075 disabling instrumentation for some early boot code.
2077 config CC_HAS_SANCOV_TRACE_PC
2078 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2082 bool "Code coverage for fuzzing"
2083 depends on ARCH_HAS_KCOV
2084 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2085 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2086 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
2088 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2089 select OBJTOOL if HAVE_NOINSTR_HACK
2091 KCOV exposes kernel code coverage information in a form suitable
2092 for coverage-guided fuzzing (randomized testing).
2094 For more details, see Documentation/dev-tools/kcov.rst.
2096 config KCOV_ENABLE_COMPARISONS
2097 bool "Enable comparison operands collection by KCOV"
2099 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2101 KCOV also exposes operands of every comparison in the instrumented
2102 code along with operand sizes and PCs of the comparison instructions.
2103 These operands can be used by fuzzing engines to improve the quality
2104 of fuzzing coverage.
2106 config KCOV_INSTRUMENT_ALL
2107 bool "Instrument all code by default"
2111 If you are doing generic system call fuzzing (like e.g. syzkaller),
2112 then you will want to instrument the whole kernel and you should
2113 say y here. If you are doing more targeted fuzzing (like e.g.
2114 filesystem fuzzing with AFL) then you will want to enable coverage
2115 for more specific subsets of files, and should say n here.
2117 config KCOV_IRQ_AREA_SIZE
2118 hex "Size of interrupt coverage collection area in words"
2122 KCOV uses preallocated per-cpu areas to collect coverage from
2123 soft interrupts. This specifies the size of those areas in the
2124 number of unsigned long words.
2126 menuconfig RUNTIME_TESTING_MENU
2127 bool "Runtime Testing"
2130 if RUNTIME_TESTING_MENU
2133 tristate "Dhrystone benchmark test"
2135 Enable this to include the Dhrystone 2.1 benchmark. This test
2136 calculates the number of Dhrystones per second, and the number of
2137 DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2138 by 1757 (the number of Dhrystones per second obtained on the VAX
2139 11/780, nominally a 1 MIPS machine).
2141 To run the benchmark, it needs to be enabled explicitly, either from
2142 the kernel command line (when built-in), or from userspace (when
2143 built-in or modular.
2145 Run once during kernel boot:
2149 Set number of iterations from kernel command line:
2151 test_dhry.iterations=<n>
2153 Set number of iterations from userspace:
2155 echo <n> > /sys/module/test_dhry/parameters/iterations
2157 Trigger manual run from userspace:
2159 echo y > /sys/module/test_dhry/parameters/run
2161 If the number of iterations is <= 0, the test will devise a suitable
2162 number of iterations (test runs for at least 2s) automatically.
2163 This process takes ca. 4s.
2168 tristate "Linux Kernel Dump Test Tool Module"
2171 This module enables testing of the different dumping mechanisms by
2172 inducing system failures at predefined crash points.
2173 If you don't need it: say N
2174 Choose M here to compile this code as a module. The module will be
2177 Documentation on how to use the module can be found in
2178 Documentation/fault-injection/provoke-crashes.rst
2180 config CPUMASK_KUNIT_TEST
2181 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2183 default KUNIT_ALL_TESTS
2185 Enable to turn on cpumask tests, running at boot or module load time.
2187 For more information on KUnit and unit tests in general, please refer
2188 to the KUnit documentation in Documentation/dev-tools/kunit/.
2192 config TEST_LIST_SORT
2193 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2195 default KUNIT_ALL_TESTS
2197 Enable this to turn on 'list_sort()' function test. This test is
2198 executed only once during system boot (so affects only boot time),
2199 or at module load time.
2203 config TEST_MIN_HEAP
2204 tristate "Min heap test"
2205 depends on DEBUG_KERNEL || m
2207 Enable this to turn on min heap function tests. This test is
2208 executed only once during system boot (so affects only boot time),
2209 or at module load time.
2214 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2216 default KUNIT_ALL_TESTS
2218 This option enables the self-test function of 'sort()' at boot,
2219 or at module load time.
2224 tristate "64bit/32bit division and modulo test"
2225 depends on DEBUG_KERNEL || m
2227 Enable this to turn on 'do_div()' function test. This test is
2228 executed only once during system boot (so affects only boot time),
2229 or at module load time.
2233 config TEST_IOV_ITER
2234 tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2236 default KUNIT_ALL_TESTS
2238 Enable this to turn on testing of the operation of the I/O iterator
2239 (iov_iter). This test is executed only once during system boot (so
2240 affects only boot time), or at module load time.
2244 config KPROBES_SANITY_TEST
2245 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2246 depends on DEBUG_KERNEL
2249 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2250 default KUNIT_ALL_TESTS
2252 This option provides for testing basic kprobes functionality on
2253 boot. Samples of kprobe and kretprobe are inserted and
2254 verified for functionality.
2256 Say N if you are unsure.
2258 config FPROBE_SANITY_TEST
2259 bool "Self test for fprobe"
2260 depends on DEBUG_KERNEL
2264 This option will enable testing the fprobe when the system boot.
2265 A series of tests are made to verify that the fprobe is functioning
2268 Say N if you are unsure.
2270 config BACKTRACE_SELF_TEST
2271 tristate "Self test for the backtrace code"
2272 depends on DEBUG_KERNEL
2274 This option provides a kernel module that can be used to test
2275 the kernel stack backtrace code. This option is not useful
2276 for distributions or general kernels, but only for kernel
2277 developers working on architecture code.
2279 Note that if you want to also test saved backtraces, you will
2280 have to enable STACKTRACE as well.
2282 Say N if you are unsure.
2284 config TEST_REF_TRACKER
2285 tristate "Self test for reference tracker"
2286 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2289 This option provides a kernel module performing tests
2290 using reference tracker infrastructure.
2292 Say N if you are unsure.
2295 tristate "Red-Black tree test"
2296 depends on DEBUG_KERNEL
2298 A benchmark measuring the performance of the rbtree library.
2299 Also includes rbtree invariant checks.
2301 config REED_SOLOMON_TEST
2302 tristate "Reed-Solomon library test"
2303 depends on DEBUG_KERNEL || m
2305 select REED_SOLOMON_ENC16
2306 select REED_SOLOMON_DEC16
2308 This option enables the self-test function of rslib at boot,
2309 or at module load time.
2313 config INTERVAL_TREE_TEST
2314 tristate "Interval tree test"
2315 depends on DEBUG_KERNEL
2316 select INTERVAL_TREE
2318 A benchmark measuring the performance of the interval tree library
2321 tristate "Per cpu operations test"
2322 depends on m && DEBUG_KERNEL
2324 Enable this option to build test module which validates per-cpu
2329 config ATOMIC64_SELFTEST
2330 tristate "Perform an atomic64_t self-test"
2332 Enable this option to test the atomic64_t functions at boot or
2333 at module load time.
2337 config ASYNC_RAID6_TEST
2338 tristate "Self test for hardware accelerated raid6 recovery"
2339 depends on ASYNC_RAID6_RECOV
2342 This is a one-shot self test that permutes through the
2343 recovery of all the possible two disk failure scenarios for a
2344 N-disk array. Recovery is performed with the asynchronous
2345 raid6 recovery routines, and will optionally use an offload
2346 engine if one is available.
2351 tristate "Test functions located in the hexdump module at runtime"
2353 config STRING_SELFTEST
2354 tristate "Test string functions at runtime"
2356 config TEST_STRING_HELPERS
2357 tristate "Test functions located in the string_helpers module at runtime"
2360 tristate "Test kstrto*() family of functions at runtime"
2363 tristate "Test printf() family of functions at runtime"
2366 tristate "Test scanf() family of functions at runtime"
2369 tristate "Test bitmap_*() family of functions at runtime"
2371 Enable this option to test the bitmap functions at boot.
2376 tristate "Test functions located in the uuid module at runtime"
2379 tristate "Test the XArray code at runtime"
2381 config TEST_MAPLE_TREE
2382 tristate "Test the Maple Tree code at runtime or module load"
2384 Enable this option to test the maple tree code functions at boot, or
2385 when the module is loaded. Enable "Debug Maple Trees" will enable
2386 more verbose output on failures.
2390 config TEST_RHASHTABLE
2391 tristate "Perform selftest on resizable hash table"
2393 Enable this option to test the rhashtable functions at boot.
2398 tristate "Perform selftest on IDA functions"
2401 tristate "Perform selftest on priority array manager"
2404 Enable this option to test priority array manager on boot
2409 config TEST_IRQ_TIMINGS
2410 bool "IRQ timings selftest"
2411 depends on IRQ_TIMINGS
2413 Enable this option to test the irq timings code on boot.
2418 tristate "Test module loading with 'hello world' module"
2421 This builds the "test_module" module that emits "Hello, world"
2422 on printk when loaded. It is designed to be used for basic
2423 evaluation of the module loading subsystem (for example when
2424 validating module verification). It lacks any extra dependencies,
2425 and will not normally be loaded by the system unless explicitly
2431 tristate "Test module for compilation of bitops operations"
2434 This builds the "test_bitops" module that is much like the
2435 TEST_LKM module except that it does a basic exercise of the
2436 set/clear_bit macros and get_count_order/long to make sure there are
2437 no compiler warnings from C=1 sparse checker or -Wextra
2438 compilations. It has no dependencies and doesn't run or load unless
2439 explicitly requested by name. for example: modprobe test_bitops.
2444 tristate "Test module for stress/performance analysis of vmalloc allocator"
2449 This builds the "test_vmalloc" module that should be used for
2450 stress and performance analysis. So, any new change for vmalloc
2451 subsystem can be evaluated from performance and stability point
2456 config TEST_USER_COPY
2457 tristate "Test user/kernel boundary protections"
2460 This builds the "test_user_copy" module that runs sanity checks
2461 on the copy_to/from_user infrastructure, making sure basic
2462 user/kernel boundary testing is working. If it fails to load,
2463 a regression has been detected in the user/kernel memory boundary
2469 tristate "Test BPF filter functionality"
2472 This builds the "test_bpf" module that runs various test vectors
2473 against the BPF interpreter or BPF JIT compiler depending on the
2474 current setting. This is in particular useful for BPF JIT compiler
2475 development, but also to run regression tests against changes in
2476 the interpreter code. It also enables test stubs for eBPF maps and
2477 verifier used by user space verifier testsuite.
2481 config TEST_BLACKHOLE_DEV
2482 tristate "Test blackhole netdev functionality"
2485 This builds the "test_blackhole_dev" module that validates the
2486 data path through this blackhole netdev.
2490 config FIND_BIT_BENCHMARK
2491 tristate "Test find_bit functions"
2493 This builds the "test_find_bit" module that measure find_*_bit()
2494 functions performance.
2498 config TEST_FIRMWARE
2499 tristate "Test firmware loading via userspace interface"
2500 depends on FW_LOADER
2502 This builds the "test_firmware" module that creates a userspace
2503 interface for testing firmware loading. This can be used to
2504 control the triggering of firmware loading without needing an
2505 actual firmware-using device. The contents can be rechecked by
2511 tristate "sysctl test driver"
2512 depends on PROC_SYSCTL
2514 This builds the "test_sysctl" module. This driver enables to test the
2515 proc sysctl interfaces available to drivers safely without affecting
2516 production knobs which might alter system functionality.
2520 config BITFIELD_KUNIT
2521 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2523 default KUNIT_ALL_TESTS
2525 Enable this option to test the bitfield functions at boot.
2527 KUnit tests run during boot and output the results to the debug log
2528 in TAP format (http://testanything.org/). Only useful for kernel devs
2529 running the KUnit test harness, and not intended for inclusion into a
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 CHECKSUM_KUNIT
2538 tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2540 default KUNIT_ALL_TESTS
2542 Enable this option to test the checksum functions at boot.
2544 KUnit tests run during boot and output the results to the debug log
2545 in TAP format (http://testanything.org/). Only useful for kernel devs
2546 running the KUnit test harness, and not intended for inclusion into a
2549 For more information on KUnit and unit tests in general please refer
2550 to the KUnit documentation in Documentation/dev-tools/kunit/.
2554 config HASH_KUNIT_TEST
2555 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2557 default KUNIT_ALL_TESTS
2559 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2560 integer (<linux/hash.h>) hash functions on boot.
2562 KUnit tests run during boot and output the results to the debug log
2563 in TAP format (https://testanything.org/). Only useful for kernel devs
2564 running the KUnit test harness, and not intended for inclusion into a
2567 For more information on KUnit and unit tests in general please refer
2568 to the KUnit documentation in Documentation/dev-tools/kunit/.
2570 This is intended to help people writing architecture-specific
2571 optimized versions. If unsure, say N.
2573 config RESOURCE_KUNIT_TEST
2574 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2576 default KUNIT_ALL_TESTS
2578 This builds the resource API unit test.
2579 Tests the logic of API provided by resource.c and ioport.h.
2580 For more information on KUnit and unit tests in general please refer
2581 to the KUnit documentation in Documentation/dev-tools/kunit/.
2585 config SYSCTL_KUNIT_TEST
2586 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2588 default KUNIT_ALL_TESTS
2590 This builds the proc sysctl unit test, which runs on boot.
2591 Tests the API contract and implementation correctness of sysctl.
2592 For more information on KUnit and unit tests in general please refer
2593 to the KUnit documentation in Documentation/dev-tools/kunit/.
2597 config LIST_KUNIT_TEST
2598 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2600 default KUNIT_ALL_TESTS
2602 This builds the linked list KUnit test suite.
2603 It tests that the API and basic functionality of the list_head type
2604 and associated macros.
2606 KUnit tests run during boot and output the results to the debug log
2607 in TAP format (https://testanything.org/). Only useful for kernel devs
2608 running the KUnit test harness, and not intended for inclusion into a
2611 For more information on KUnit and unit tests in general please refer
2612 to the KUnit documentation in Documentation/dev-tools/kunit/.
2616 config HASHTABLE_KUNIT_TEST
2617 tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2619 default KUNIT_ALL_TESTS
2621 This builds the hashtable KUnit test suite.
2622 It tests the basic functionality of the API defined in
2623 include/linux/hashtable.h. For more information on KUnit and
2624 unit tests in general please refer to the KUnit documentation
2625 in Documentation/dev-tools/kunit/.
2629 config LINEAR_RANGES_TEST
2630 tristate "KUnit test for linear_ranges"
2632 select LINEAR_RANGES
2634 This builds the linear_ranges unit test, which runs on boot.
2635 Tests the linear_ranges logic correctness.
2636 For more information on KUnit and unit tests in general please refer
2637 to the KUnit documentation in Documentation/dev-tools/kunit/.
2641 config CMDLINE_KUNIT_TEST
2642 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2644 default KUNIT_ALL_TESTS
2646 This builds the cmdline API unit test.
2647 Tests the logic of API provided by cmdline.c.
2648 For more information on KUnit and unit tests in general please refer
2649 to the KUnit documentation in Documentation/dev-tools/kunit/.
2654 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2656 default KUNIT_ALL_TESTS
2658 This builds the bits unit test.
2659 Tests the logic of macros defined in bits.h.
2660 For more information on KUnit and unit tests in general please refer
2661 to the KUnit documentation in Documentation/dev-tools/kunit/.
2665 config SLUB_KUNIT_TEST
2666 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2667 depends on SLUB_DEBUG && KUNIT
2668 default KUNIT_ALL_TESTS
2670 This builds SLUB allocator unit test.
2671 Tests SLUB cache debugging functionality.
2672 For more information on KUnit and unit tests in general please refer
2673 to the KUnit documentation in Documentation/dev-tools/kunit/.
2677 config RATIONAL_KUNIT_TEST
2678 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2679 depends on KUNIT && RATIONAL
2680 default KUNIT_ALL_TESTS
2682 This builds the rational math unit test.
2683 For more information on KUnit and unit tests in general please refer
2684 to the KUnit documentation in Documentation/dev-tools/kunit/.
2688 config MEMCPY_KUNIT_TEST
2689 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2691 default KUNIT_ALL_TESTS
2693 Builds unit tests for memcpy(), memmove(), and memset() functions.
2694 For more information on KUnit and unit tests in general please refer
2695 to the KUnit documentation in Documentation/dev-tools/kunit/.
2699 config MEMCPY_SLOW_KUNIT_TEST
2700 bool "Include exhaustive memcpy tests"
2701 depends on MEMCPY_KUNIT_TEST
2704 Some memcpy tests are quite exhaustive in checking for overlaps
2705 and bit ranges. These can be very slow, so they are split out
2706 as a separate config, in case they need to be disabled.
2708 Note this config option will be replaced by the use of KUnit test
2711 config IS_SIGNED_TYPE_KUNIT_TEST
2712 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2714 default KUNIT_ALL_TESTS
2716 Builds unit tests for the is_signed_type() macro.
2718 For more information on KUnit and unit tests in general please refer
2719 to the KUnit documentation in Documentation/dev-tools/kunit/.
2723 config OVERFLOW_KUNIT_TEST
2724 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2726 default KUNIT_ALL_TESTS
2728 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2731 For more information on KUnit and unit tests in general please refer
2732 to the KUnit documentation in Documentation/dev-tools/kunit/.
2736 config STACKINIT_KUNIT_TEST
2737 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2739 default KUNIT_ALL_TESTS
2741 Test if the kernel is zero-initializing stack variables and
2742 padding. Coverage is controlled by compiler flags,
2743 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2744 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2745 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2747 config FORTIFY_KUNIT_TEST
2748 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2749 depends on KUNIT && FORTIFY_SOURCE
2750 default KUNIT_ALL_TESTS
2752 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2753 by the str*() and mem*() family of functions. For testing runtime
2754 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2756 config HW_BREAKPOINT_KUNIT_TEST
2757 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2758 depends on HAVE_HW_BREAKPOINT
2760 default KUNIT_ALL_TESTS
2762 Tests for hw_breakpoint constraints accounting.
2766 config STRCAT_KUNIT_TEST
2767 tristate "Test strcat() family of functions at runtime" if !KUNIT_ALL_TESTS
2769 default KUNIT_ALL_TESTS
2771 config STRSCPY_KUNIT_TEST
2772 tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
2774 default KUNIT_ALL_TESTS
2776 config SIPHASH_KUNIT_TEST
2777 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2779 default KUNIT_ALL_TESTS
2781 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2782 functions on boot (or module load).
2784 This is intended to help people writing architecture-specific
2785 optimized versions. If unsure, say N.
2788 tristate "udelay test driver"
2790 This builds the "udelay_test" module that helps to make sure
2791 that udelay() is working properly.
2795 config TEST_STATIC_KEYS
2796 tristate "Test static keys"
2799 Test the static key interfaces.
2803 config TEST_DYNAMIC_DEBUG
2804 tristate "Test DYNAMIC_DEBUG"
2805 depends on DYNAMIC_DEBUG
2807 This module registers a tracer callback to count enabled
2808 pr_debugs in a 'do_debugging' function, then alters their
2809 enablements, calls the function, and compares counts.
2814 tristate "kmod stress tester"
2816 depends on NETDEVICES && NET_CORE && INET # for TUN
2818 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2824 Test the kernel's module loading mechanism: kmod. kmod implements
2825 support to load modules using the Linux kernel's usermode helper.
2826 This test provides a series of tests against kmod.
2828 Although technically you can either build test_kmod as a module or
2829 into the kernel we disallow building it into the kernel since
2830 it stress tests request_module() and this will very likely cause
2831 some issues by taking over precious threads available from other
2832 module load requests, ultimately this could be fatal.
2836 tools/testing/selftests/kmod/kmod.sh --help
2840 config TEST_DEBUG_VIRTUAL
2841 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2842 depends on DEBUG_VIRTUAL
2844 Test the kernel's ability to detect incorrect calls to
2845 virt_to_phys() done against the non-linear part of the
2846 kernel's virtual address map.
2850 config TEST_MEMCAT_P
2851 tristate "Test memcat_p() helper function"
2853 Test the memcat_p() helper for correctly merging two
2854 pointer arrays together.
2858 config TEST_LIVEPATCH
2859 tristate "Test livepatching"
2861 depends on DYNAMIC_DEBUG
2862 depends on LIVEPATCH
2865 Test kernel livepatching features for correctness. The tests will
2866 load test modules that will be livepatched in various scenarios.
2868 To run all the livepatching tests:
2870 make -C tools/testing/selftests TARGETS=livepatch run_tests
2872 Alternatively, individual tests may be invoked:
2874 tools/testing/selftests/livepatch/test-callbacks.sh
2875 tools/testing/selftests/livepatch/test-livepatch.sh
2876 tools/testing/selftests/livepatch/test-shadow-vars.sh
2881 tristate "Perform selftest on object aggreration manager"
2885 Enable this option to test object aggregation manager on boot
2889 tristate "Test heap/page initialization"
2891 Test if the kernel is zero-initializing heap and page allocations.
2892 This can be useful to test init_on_alloc and init_on_free features.
2897 tristate "Test HMM (Heterogeneous Memory Management)"
2898 depends on TRANSPARENT_HUGEPAGE
2899 depends on DEVICE_PRIVATE
2903 This is a pseudo device driver solely for testing HMM.
2904 Say M here if you want to build the HMM test module.
2905 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2909 config TEST_FREE_PAGES
2910 tristate "Test freeing pages"
2912 Test that a memory leak does not occur due to a race between
2913 freeing a block of pages and a speculative page reference.
2914 Loading this module is safe if your kernel has the bug fixed.
2915 If the bug is not fixed, it will leak gigabytes of memory and
2916 probably OOM your system.
2919 tristate "Test floating point operations in kernel space"
2920 depends on X86 && !KCOV_INSTRUMENT_ALL
2922 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2923 which will trigger a sequence of floating point operations. This is used
2924 for self-testing floating point control register setting in
2929 config TEST_CLOCKSOURCE_WATCHDOG
2930 tristate "Test clocksource watchdog in kernel space"
2931 depends on CLOCKSOURCE_WATCHDOG
2933 Enable this option to create a kernel module that will trigger
2934 a test of the clocksource watchdog. This module may be loaded
2935 via modprobe or insmod in which case it will run upon being
2936 loaded, or it may be built in, in which case it will run
2942 tristate "Test module for correctness and stress of objpool"
2944 depends on m && DEBUG_KERNEL
2946 This builds the "test_objpool" module that should be used for
2947 correctness verification and concurrent testings of objects
2948 allocation and reclamation.
2952 endif # RUNTIME_TESTING_MENU
2954 config ARCH_USE_MEMTEST
2957 An architecture should select this when it uses early_memtest()
2958 during boot process.
2962 depends on ARCH_USE_MEMTEST
2964 This option adds a kernel parameter 'memtest', which allows memtest
2965 to be set and executed.
2966 memtest=0, mean disabled; -- default
2967 memtest=1, mean do 1 test pattern;
2969 memtest=17, mean do 17 test patterns.
2970 If you are unsure how to answer this question, answer N.
2974 config HYPERV_TESTING
2975 bool "Microsoft Hyper-V driver testing"
2977 depends on HYPERV && DEBUG_FS
2979 Select this option to enable Hyper-V vmbus testing.
2981 endmenu # "Kernel Testing and Coverage"
2985 config RUST_DEBUG_ASSERTIONS
2986 bool "Debug assertions"
2989 Enables rustc's `-Cdebug-assertions` codegen option.
2991 This flag lets you turn `cfg(debug_assertions)` conditional
2992 compilation on or off. This can be used to enable extra debugging
2993 code in development but not in production. For example, it controls
2994 the behavior of the standard library's `debug_assert!` macro.
2996 Note that this will apply to all Rust code, including `core`.
3000 config RUST_OVERFLOW_CHECKS
3001 bool "Overflow checks"
3005 Enables rustc's `-Coverflow-checks` codegen option.
3007 This flag allows you to control the behavior of runtime integer
3008 overflow. When overflow-checks are enabled, a Rust panic will occur
3011 Note that this will apply to all Rust code, including `core`.
3015 config RUST_BUILD_ASSERT_ALLOW
3016 bool "Allow unoptimized build-time assertions"
3019 Controls how are `build_error!` and `build_assert!` handled during build.
3021 If calls to them exist in the binary, it may indicate a violated invariant
3022 or that the optimizer failed to verify the invariant during compilation.
3024 This should not happen, thus by default the build is aborted. However,
3025 as an escape hatch, you can choose Y here to ignore them during build
3026 and let the check be carried at runtime (with `panic!` being called if
3031 config RUST_KERNEL_DOCTESTS
3032 bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3033 depends on RUST && KUNIT=y
3034 default KUNIT_ALL_TESTS
3036 This builds the documentation tests of the `kernel` crate
3039 For more information on KUnit and unit tests in general,
3040 please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3046 endmenu # Kernel hacking