1 # SPDX-License-Identifier: GPL-2.0-only
4 menu "printk and dmesg options"
7 bool "Show timing information on printks"
10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
22 bool "Show caller information on printks"
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
38 config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
49 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
54 Default loglevel to determine what will be printed on the console.
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
60 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
64 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
69 loglevel to use when "quiet" is passed on the kernel commandline.
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
75 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)"
80 Default log level for printk statements with no specified priority.
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
90 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
109 bool "Enable dynamic printk() support"
112 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
138 filename:lineno [module]function flags format
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
180 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
183 depends on (DEBUG_FS || PROC_FS)
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
191 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
200 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
209 endmenu # "printk and dmesg options"
212 bool "Kernel debugging"
214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems.
218 bool "Miscellaneous debug code"
220 depends on DEBUG_KERNEL
222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug option but isn't.
225 menu "Compile-time checks and compiler options"
230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice below, indicating that debug
232 information will be generated for build targets.
235 prompt "Debug information"
236 depends on DEBUG_KERNEL
238 Selecting something other than "None" results in a kernel image
239 that will include debugging info resulting in a larger kernel image.
240 This adds debug symbols to the kernel and modules (gcc -g), and
241 is needed if you intend to use kernel crashdump or binary object
242 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
244 Choose which version of DWARF debug info to emit. If unsure,
245 select "Toolchain default".
247 config DEBUG_INFO_NONE
248 bool "Disable debug information"
250 Do not build the kernel with debugging information, which will
251 result in a faster and smaller build.
253 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
254 bool "Rely on the toolchain's implicit default DWARF version"
256 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502)
258 The implicit default version of DWARF debug info produced by a
259 toolchain changes over time.
261 This can break consumers of the debug info that haven't upgraded to
262 support newer revisions, and prevent testing newer versions, but
263 those should be less common scenarios.
265 config DEBUG_INFO_DWARF4
266 bool "Generate DWARF Version 4 debuginfo"
268 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
270 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
271 if using clang without clang's integrated assembler, and gdb 7.0+.
273 If you have consumers of DWARF debug info that are not ready for
274 newer revisions of DWARF, you may wish to choose this or have your
277 config DEBUG_INFO_DWARF5
278 bool "Generate DWARF Version 5 debuginfo"
280 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
282 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
283 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
284 draft features until 7.0), and gdb 8.0+.
286 Changes to the structure of debug info in Version 5 allow for around
287 15-18% savings in resulting image and debug info section sizes as
288 compared to DWARF Version 4. DWARF Version 5 standardizes previous
289 extensions such as accelerators for symbol indexing and the format
290 for fission (.dwo/.dwp) files. Users may not want to select this
291 config if they rely on tooling that has not yet been updated to
292 support DWARF Version 5.
294 endchoice # "Debug information"
298 config DEBUG_INFO_REDUCED
299 bool "Reduce debugging information"
301 If you say Y here gcc is instructed to generate less debugging
302 information for structure types. This means that tools that
303 need full debugging information (like kgdb or systemtap) won't
304 be happy. But if you merely need debugging information to
305 resolve line numbers there is no loss. Advantage is that
306 build directory object sizes shrink dramatically over a full
307 DEBUG_INFO build and compile times are reduced too.
308 Only works with newer gcc versions.
310 config DEBUG_INFO_COMPRESSED
311 bool "Compressed debugging information"
312 depends on $(cc-option,-gz=zlib)
313 depends on $(ld-option,--compress-debug-sections=zlib)
315 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
316 5.0+, binutils 2.26+, and zlib.
318 Users of dpkg-deb via scripts/package/builddeb may find an increase in
319 size of their debug .deb packages with this config set, due to the
320 debug info being compressed with zlib, then the object files being
321 recompressed with a different compression scheme. But this is still
322 preferable to setting $KDEB_COMPRESS to "none" which would be even
325 config DEBUG_INFO_SPLIT
326 bool "Produce split debuginfo in .dwo files"
327 depends on $(cc-option,-gsplit-dwarf)
329 Generate debug info into separate .dwo files. This significantly
330 reduces the build directory size for builds with DEBUG_INFO,
331 because it stores the information only once on disk in .dwo
332 files instead of multiple times in object files and executables.
333 In addition the debug information is also compressed.
335 Requires recent gcc (4.7+) and recent gdb/binutils.
336 Any tool that packages or reads debug information would need
337 to know about the .dwo files and include them.
338 Incompatible with older versions of ccache.
340 config DEBUG_INFO_BTF
341 bool "Generate BTF typeinfo"
342 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
343 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
344 depends on BPF_SYSCALL
345 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
347 Generate deduplicated BTF type information from DWARF debug info.
348 Turning this on expects presence of pahole tool, which will convert
349 DWARF type info into equivalent deduplicated BTF type info.
351 config PAHOLE_HAS_SPLIT_BTF
352 def_bool PAHOLE_VERSION >= 119
354 config PAHOLE_HAS_BTF_TAG
355 def_bool PAHOLE_VERSION >= 123
356 depends on CC_IS_CLANG
358 Decide whether pahole emits btf_tag attributes (btf_type_tag and
359 btf_decl_tag) or not. Currently only clang compiler implements
360 these attributes, so make the config depend on CC_IS_CLANG.
362 config DEBUG_INFO_BTF_MODULES
364 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
366 Generate compact split BTF type information for kernel modules.
368 config MODULE_ALLOW_BTF_MISMATCH
369 bool "Allow loading modules with non-matching BTF type info"
370 depends on DEBUG_INFO_BTF_MODULES
372 For modules whose split BTF does not match vmlinux, load without
373 BTF rather than refusing to load. The default behavior with
374 module BTF enabled is to reject modules with such mismatches;
375 this option will still load module BTF where possible but ignore
376 it when a mismatch is found.
379 bool "Provide GDB scripts for kernel debugging"
381 This creates the required links to GDB helper scripts in the
382 build directory. If you load vmlinux into gdb, the helper
383 scripts will be automatically imported by gdb as well, and
384 additional functions are available to analyze a Linux kernel
385 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
391 int "Warn for stack frames larger than"
393 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
394 default 2048 if PARISC
395 default 1536 if (!64BIT && XTENSA)
396 default 1024 if !64BIT
397 default 2048 if 64BIT
399 Tell gcc to warn at build time for stack frames larger than this.
400 Setting this too low will cause a lot of warnings.
401 Setting it to 0 disables the warning.
403 config STRIP_ASM_SYMS
404 bool "Strip assembler-generated symbols during link"
407 Strip internal assembler-generated symbols during a link (symbols
408 that look like '.Lxxx') so they don't pollute the output of
409 get_wchan() and suchlike.
412 bool "Generate readable assembler code"
413 depends on DEBUG_KERNEL
416 Disable some compiler optimizations that tend to generate human unreadable
417 assembler output. This may make the kernel slightly slower, but it helps
418 to keep kernel developers who have to stare a lot at assembler listings
421 config HEADERS_INSTALL
422 bool "Install uapi headers to usr/include"
425 This option will install uapi headers (headers exported to user-space)
426 into the usr/include directory for use during the kernel build.
427 This is unneeded for building the kernel itself, but needed for some
428 user-space program samples. It is also needed by some features such
429 as uapi header sanity checks.
431 config DEBUG_SECTION_MISMATCH
432 bool "Enable full Section mismatch analysis"
435 The section mismatch analysis checks if there are illegal
436 references from one section to another section.
437 During linktime or runtime, some sections are dropped;
438 any use of code/data previously in these sections would
439 most likely result in an oops.
440 In the code, functions and variables are annotated with
441 __init,, etc. (see the full list in include/linux/init.h),
442 which results in the code/data being placed in specific sections.
443 The section mismatch analysis is always performed after a full
444 kernel build, and enabling this option causes the following
445 additional step to occur:
446 - Add the option -fno-inline-functions-called-once to gcc commands.
447 When inlining a function annotated with __init in a non-init
448 function, we would lose the section information and thus
449 the analysis would not catch the illegal reference.
450 This option tells gcc to inline less (but it does result in
453 config SECTION_MISMATCH_WARN_ONLY
454 bool "Make section mismatch errors non-fatal"
457 If you say N here, the build process will fail if there are any
458 section mismatch, instead of just throwing warnings.
462 config DEBUG_FORCE_FUNCTION_ALIGN_64B
463 bool "Force all function address 64B aligned"
464 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
466 There are cases that a commit from one domain changes the function
467 address alignment of other domains, and cause magic performance
468 bump (regression or improvement). Enable this option will help to
469 verify if the bump is caused by function alignment changes, while
470 it will slightly increase the kernel size and affect icache usage.
472 It is mainly for debug and performance tuning use.
475 # Select this config option from the architecture Kconfig, if it
476 # is preferred to always offer frame pointers as a config
477 # option on the architecture (regardless of KERNEL_DEBUG):
479 config ARCH_WANT_FRAME_POINTERS
483 bool "Compile the kernel with frame pointers"
484 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
485 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
487 If you say Y here the resulting kernel image will be slightly
488 larger and slower, but it gives very useful debugging information
489 in case of kernel bugs. (precise oopses/stacktraces/warnings)
494 config STACK_VALIDATION
495 bool "Compile-time stack metadata validation"
496 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
500 Validate frame pointer rules at compile-time. This helps ensure that
501 runtime stack traces are more reliable.
503 For more information, see
504 tools/objtool/Documentation/objtool.txt.
506 config NOINSTR_VALIDATION
508 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
513 bool "Generate vmlinux.map file when linking"
516 Selecting this option will pass "-Map=vmlinux.map" to ld
517 when linking vmlinux. That file can be useful for verifying
518 and debugging magic section games, and for seeing which
519 pieces of code get eliminated with
520 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
522 config DEBUG_FORCE_WEAK_PER_CPU
523 bool "Force weak per-cpu definitions"
524 depends on DEBUG_KERNEL
526 s390 and alpha require percpu variables in modules to be
527 defined weak to work around addressing range issue which
528 puts the following two restrictions on percpu variable
531 1. percpu symbols must be unique whether static or not
532 2. percpu variables can't be defined inside a function
534 To ensure that generic code follows the above rules, this
535 option forces all percpu variables to be defined as weak.
537 endmenu # "Compiler options"
539 menu "Generic Kernel Debugging Instruments"
542 bool "Magic SysRq key"
545 If you say Y here, you will have some control over the system even
546 if the system crashes for example during kernel debugging (e.g., you
547 will be able to flush the buffer cache to disk, reboot the system
548 immediately or dump some status information). This is accomplished
549 by pressing various keys while holding SysRq (Alt+PrintScreen). It
550 also works on a serial console (on PC hardware at least), if you
551 send a BREAK and then within 5 seconds a command keypress. The
552 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
553 Don't say Y unless you really know what this hack does.
555 config MAGIC_SYSRQ_DEFAULT_ENABLE
556 hex "Enable magic SysRq key functions by default"
557 depends on MAGIC_SYSRQ
560 Specifies which SysRq key functions are enabled by default.
561 This may be set to 1 or 0 to enable or disable them all, or
562 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
564 config MAGIC_SYSRQ_SERIAL
565 bool "Enable magic SysRq key over serial"
566 depends on MAGIC_SYSRQ
569 Many embedded boards have a disconnected TTL level serial which can
570 generate some garbage that can lead to spurious false sysrq detects.
571 This option allows you to decide whether you want to enable the
574 config MAGIC_SYSRQ_SERIAL_SEQUENCE
575 string "Char sequence that enables magic SysRq over serial"
576 depends on MAGIC_SYSRQ_SERIAL
579 Specifies a sequence of characters that can follow BREAK to enable
580 SysRq on a serial console.
582 If unsure, leave an empty string and the option will not be enabled.
585 bool "Debug Filesystem"
587 debugfs is a virtual file system that kernel developers use to put
588 debugging files into. Enable this option to be able to read and
589 write to these files.
591 For detailed documentation on the debugfs API, see
592 Documentation/filesystems/.
597 prompt "Debugfs default access"
599 default DEBUG_FS_ALLOW_ALL
601 This selects the default access restrictions for debugfs.
602 It can be overridden with kernel command line option
603 debugfs=[on,no-mount,off]. The restrictions apply for API access
604 and filesystem registration.
606 config DEBUG_FS_ALLOW_ALL
609 No restrictions apply. Both API and filesystem registration
610 is on. This is the normal default operation.
612 config DEBUG_FS_DISALLOW_MOUNT
613 bool "Do not register debugfs as filesystem"
615 The API is open but filesystem is not loaded. Clients can still do
616 their work and read with debug tools that do not need
619 config DEBUG_FS_ALLOW_NONE
622 Access is off. Clients get -PERM when trying to create nodes in
623 debugfs tree and debugfs is not registered as a filesystem.
624 Client can then back-off or continue without debugfs access.
628 source "lib/Kconfig.kgdb"
629 source "lib/Kconfig.ubsan"
630 source "lib/Kconfig.kcsan"
634 menu "Networking Debugging"
636 source "net/Kconfig.debug"
638 endmenu # "Networking Debugging"
640 menu "Memory Debugging"
642 source "mm/Kconfig.debug"
645 bool "Debug object operations"
646 depends on DEBUG_KERNEL
648 If you say Y here, additional code will be inserted into the
649 kernel to track the life time of various objects and validate
650 the operations on those objects.
652 config DEBUG_OBJECTS_SELFTEST
653 bool "Debug objects selftest"
654 depends on DEBUG_OBJECTS
656 This enables the selftest of the object debug code.
658 config DEBUG_OBJECTS_FREE
659 bool "Debug objects in freed memory"
660 depends on DEBUG_OBJECTS
662 This enables checks whether a k/v free operation frees an area
663 which contains an object which has not been deactivated
664 properly. This can make kmalloc/kfree-intensive workloads
667 config DEBUG_OBJECTS_TIMERS
668 bool "Debug timer objects"
669 depends on DEBUG_OBJECTS
671 If you say Y here, additional code will be inserted into the
672 timer routines to track the life time of timer objects and
673 validate the timer operations.
675 config DEBUG_OBJECTS_WORK
676 bool "Debug work objects"
677 depends on DEBUG_OBJECTS
679 If you say Y here, additional code will be inserted into the
680 work queue routines to track the life time of work objects and
681 validate the work operations.
683 config DEBUG_OBJECTS_RCU_HEAD
684 bool "Debug RCU callbacks objects"
685 depends on DEBUG_OBJECTS
687 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
689 config DEBUG_OBJECTS_PERCPU_COUNTER
690 bool "Debug percpu counter objects"
691 depends on DEBUG_OBJECTS
693 If you say Y here, additional code will be inserted into the
694 percpu counter routines to track the life time of percpu counter
695 objects and validate the percpu counter operations.
697 config DEBUG_OBJECTS_ENABLE_DEFAULT
698 int "debug_objects bootup default value (0-1)"
701 depends on DEBUG_OBJECTS
703 Debug objects boot parameter default value
705 config SHRINKER_DEBUG
706 bool "Enable shrinker debugging support"
709 Say Y to enable the shrinker debugfs interface which provides
710 visibility into the kernel memory shrinkers subsystem.
711 Disable it to avoid an extra memory footprint.
713 config HAVE_DEBUG_KMEMLEAK
716 config DEBUG_KMEMLEAK
717 bool "Kernel memory leak detector"
718 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
720 select STACKTRACE if STACKTRACE_SUPPORT
724 Say Y here if you want to enable the memory leak
725 detector. The memory allocation/freeing is traced in a way
726 similar to the Boehm's conservative garbage collector, the
727 difference being that the orphan objects are not freed but
728 only shown in /sys/kernel/debug/kmemleak. Enabling this
729 feature will introduce an overhead to memory
730 allocations. See Documentation/dev-tools/kmemleak.rst for more
733 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
734 of finding leaks due to the slab objects poisoning.
736 In order to access the kmemleak file, debugfs needs to be
737 mounted (usually at /sys/kernel/debug).
739 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
740 int "Kmemleak memory pool size"
741 depends on DEBUG_KMEMLEAK
745 Kmemleak must track all the memory allocations to avoid
746 reporting false positives. Since memory may be allocated or
747 freed before kmemleak is fully initialised, use a static pool
748 of metadata objects to track such callbacks. After kmemleak is
749 fully initialised, this memory pool acts as an emergency one
750 if slab allocations fail.
752 config DEBUG_KMEMLEAK_TEST
753 tristate "Simple test for the kernel memory leak detector"
754 depends on DEBUG_KMEMLEAK && m
756 This option enables a module that explicitly leaks memory.
760 config DEBUG_KMEMLEAK_DEFAULT_OFF
761 bool "Default kmemleak to off"
762 depends on DEBUG_KMEMLEAK
764 Say Y here to disable kmemleak by default. It can then be enabled
765 on the command line via kmemleak=on.
767 config DEBUG_KMEMLEAK_AUTO_SCAN
768 bool "Enable kmemleak auto scan thread on boot up"
770 depends on DEBUG_KMEMLEAK
772 Depending on the cpu, kmemleak scan may be cpu intensive and can
773 stall user tasks at times. This option enables/disables automatic
774 kmemleak scan at boot up.
776 Say N here to disable kmemleak auto scan thread to stop automatic
777 scanning. Disabling this option disables automatic reporting of
782 config DEBUG_STACK_USAGE
783 bool "Stack utilization instrumentation"
784 depends on DEBUG_KERNEL && !IA64
786 Enables the display of the minimum amount of free stack which each
787 task has ever had available in the sysrq-T and sysrq-P debug output.
789 This option will slow down process creation somewhat.
791 config SCHED_STACK_END_CHECK
792 bool "Detect stack corruption on calls to schedule()"
793 depends on DEBUG_KERNEL
796 This option checks for a stack overrun on calls to schedule().
797 If the stack end location is found to be over written always panic as
798 the content of the corrupted region can no longer be trusted.
799 This is to ensure no erroneous behaviour occurs which could result in
800 data corruption or a sporadic crash at a later stage once the region
801 is examined. The runtime overhead introduced is minimal.
803 config ARCH_HAS_DEBUG_VM_PGTABLE
806 An architecture should select this when it can successfully
807 build and run DEBUG_VM_PGTABLE.
809 config DEBUG_VM_IRQSOFF
810 def_bool DEBUG_VM && !PREEMPT_RT
814 depends on DEBUG_KERNEL
816 Enable this to turn on extended checks in the virtual-memory system
817 that may impact performance.
821 config DEBUG_VM_VMACACHE
822 bool "Debug VMA caching"
825 Enable this to turn on VMA caching debug information. Doing so
826 can cause significant overhead, so only enable it in non-production
832 bool "Debug VM red-black trees"
835 Enable VM red-black tree debugging information and extra validations.
839 config DEBUG_VM_PGFLAGS
840 bool "Debug page-flags operations"
843 Enables extra validation on page flags operations.
847 config DEBUG_VM_PGTABLE
848 bool "Debug arch page table for semantics compliance"
850 depends on ARCH_HAS_DEBUG_VM_PGTABLE
851 default y if DEBUG_VM
853 This option provides a debug method which can be used to test
854 architecture page table helper functions on various platforms in
855 verifying if they comply with expected generic MM semantics. This
856 will help architecture code in making sure that any changes or
857 new additions of these helpers still conform to expected
858 semantics of the generic MM. Platforms will have to opt in for
859 this through ARCH_HAS_DEBUG_VM_PGTABLE.
863 config ARCH_HAS_DEBUG_VIRTUAL
867 bool "Debug VM translations"
868 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
870 Enable some costly sanity checks in virtual to page code. This can
871 catch mistakes with virt_to_page() and friends.
875 config DEBUG_NOMMU_REGIONS
876 bool "Debug the global anon/private NOMMU mapping region tree"
877 depends on DEBUG_KERNEL && !MMU
879 This option causes the global tree of anonymous and private mapping
880 regions to be regularly checked for invalid topology.
882 config DEBUG_MEMORY_INIT
883 bool "Debug memory initialisation" if EXPERT
886 Enable this for additional checks during memory initialisation.
887 The sanity checks verify aspects of the VM such as the memory model
888 and other information provided by the architecture. Verbose
889 information will be printed at KERN_DEBUG loglevel depending
890 on the mminit_loglevel= command-line option.
894 config MEMORY_NOTIFIER_ERROR_INJECT
895 tristate "Memory hotplug notifier error injection module"
896 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
898 This option provides the ability to inject artificial errors to
899 memory hotplug notifier chain callbacks. It is controlled through
900 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
902 If the notifier call chain should be failed with some events
903 notified, write the error code to "actions/<notifier event>/error".
905 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
907 # cd /sys/kernel/debug/notifier-error-inject/memory
908 # echo -12 > actions/MEM_GOING_OFFLINE/error
909 # echo offline > /sys/devices/system/memory/memoryXXX/state
910 bash: echo: write error: Cannot allocate memory
912 To compile this code as a module, choose M here: the module will
913 be called memory-notifier-error-inject.
917 config DEBUG_PER_CPU_MAPS
918 bool "Debug access to per_cpu maps"
919 depends on DEBUG_KERNEL
922 Say Y to verify that the per_cpu map being accessed has
923 been set up. This adds a fair amount of code to kernel memory
924 and decreases performance.
928 config DEBUG_KMAP_LOCAL
929 bool "Debug kmap_local temporary mappings"
930 depends on DEBUG_KERNEL && KMAP_LOCAL
932 This option enables additional error checking for the kmap_local
933 infrastructure. Disable for production use.
935 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
938 config DEBUG_KMAP_LOCAL_FORCE_MAP
939 bool "Enforce kmap_local temporary mappings"
940 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
942 select DEBUG_KMAP_LOCAL
944 This option enforces temporary mappings through the kmap_local
945 mechanism for non-highmem pages and on non-highmem systems.
946 Disable this for production systems!
949 bool "Highmem debugging"
950 depends on DEBUG_KERNEL && HIGHMEM
951 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
952 select DEBUG_KMAP_LOCAL
954 This option enables additional error checking for high memory
955 systems. Disable for production systems.
957 config HAVE_DEBUG_STACKOVERFLOW
960 config DEBUG_STACKOVERFLOW
961 bool "Check for stack overflows"
962 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
964 Say Y here if you want to check for overflows of kernel, IRQ
965 and exception stacks (if your architecture uses them). This
966 option will show detailed messages if free stack space drops
967 below a certain limit.
969 These kinds of bugs usually occur when call-chains in the
970 kernel get too deep, especially when interrupts are
973 Use this in cases where you see apparently random memory
974 corruption, especially if it appears in 'struct thread_info'
976 If in doubt, say "N".
978 source "lib/Kconfig.kasan"
979 source "lib/Kconfig.kfence"
981 endmenu # "Memory Debugging"
984 bool "Debug shared IRQ handlers"
985 depends on DEBUG_KERNEL
987 Enable this to generate a spurious interrupt just before a shared
988 interrupt handler is deregistered (generating one when registering
989 is currently disabled). Drivers need to handle this correctly. Some
990 don't and need to be caught.
992 menu "Debug Oops, Lockups and Hangs"
997 Say Y here to enable the kernel to panic when it oopses. This
998 has the same effect as setting oops=panic on the kernel command
1001 This feature is useful to ensure that the kernel does not do
1002 anything erroneous after an oops which could result in data
1003 corruption or other issues.
1007 config PANIC_ON_OOPS_VALUE
1010 default 0 if !PANIC_ON_OOPS
1011 default 1 if PANIC_ON_OOPS
1013 config PANIC_TIMEOUT
1017 Set the timeout value (in seconds) until a reboot occurs when
1018 the kernel panics. If n = 0, then we wait forever. A timeout
1019 value n > 0 will wait n seconds before rebooting, while a timeout
1020 value n < 0 will reboot immediately.
1022 config LOCKUP_DETECTOR
1025 config SOFTLOCKUP_DETECTOR
1026 bool "Detect Soft Lockups"
1027 depends on DEBUG_KERNEL && !S390
1028 select LOCKUP_DETECTOR
1030 Say Y here to enable the kernel to act as a watchdog to detect
1033 Softlockups are bugs that cause the kernel to loop in kernel
1034 mode for more than 20 seconds, without giving other tasks a
1035 chance to run. The current stack trace is displayed upon
1036 detection and the system will stay locked up.
1038 config BOOTPARAM_SOFTLOCKUP_PANIC
1039 bool "Panic (Reboot) On Soft Lockups"
1040 depends on SOFTLOCKUP_DETECTOR
1042 Say Y here to enable the kernel to panic on "soft lockups",
1043 which are bugs that cause the kernel to loop in kernel
1044 mode for more than 20 seconds (configurable using the watchdog_thresh
1045 sysctl), without giving other tasks a chance to run.
1047 The panic can be used in combination with panic_timeout,
1048 to cause the system to reboot automatically after a
1049 lockup has been detected. This feature is useful for
1050 high-availability systems that have uptime guarantees and
1051 where a lockup must be resolved ASAP.
1055 config HARDLOCKUP_DETECTOR_PERF
1057 select SOFTLOCKUP_DETECTOR
1060 # Enables a timestamp based low pass filter to compensate for perf based
1061 # hard lockup detection which runs too fast due to turbo modes.
1063 config HARDLOCKUP_CHECK_TIMESTAMP
1067 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1068 # lockup detector rather than the perf based detector.
1070 config HARDLOCKUP_DETECTOR
1071 bool "Detect Hard Lockups"
1072 depends on DEBUG_KERNEL && !S390
1073 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1074 select LOCKUP_DETECTOR
1075 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1077 Say Y here to enable the kernel to act as a watchdog to detect
1080 Hardlockups are bugs that cause the CPU to loop in kernel mode
1081 for more than 10 seconds, without letting other interrupts have a
1082 chance to run. The current stack trace is displayed upon detection
1083 and the system will stay locked up.
1085 config BOOTPARAM_HARDLOCKUP_PANIC
1086 bool "Panic (Reboot) On Hard Lockups"
1087 depends on HARDLOCKUP_DETECTOR
1089 Say Y here to enable the kernel to panic on "hard lockups",
1090 which are bugs that cause the kernel to loop in kernel
1091 mode with interrupts disabled for more than 10 seconds (configurable
1092 using the watchdog_thresh sysctl).
1096 config DETECT_HUNG_TASK
1097 bool "Detect Hung Tasks"
1098 depends on DEBUG_KERNEL
1099 default SOFTLOCKUP_DETECTOR
1101 Say Y here to enable the kernel to detect "hung tasks",
1102 which are bugs that cause the task to be stuck in
1103 uninterruptible "D" state indefinitely.
1105 When a hung task is detected, the kernel will print the
1106 current stack trace (which you should report), but the
1107 task will stay in uninterruptible state. If lockdep is
1108 enabled then all held locks will also be reported. This
1109 feature has negligible overhead.
1111 config DEFAULT_HUNG_TASK_TIMEOUT
1112 int "Default timeout for hung task detection (in seconds)"
1113 depends on DETECT_HUNG_TASK
1116 This option controls the default timeout (in seconds) used
1117 to determine when a task has become non-responsive and should
1120 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1121 sysctl or by writing a value to
1122 /proc/sys/kernel/hung_task_timeout_secs.
1124 A timeout of 0 disables the check. The default is two minutes.
1125 Keeping the default should be fine in most cases.
1127 config BOOTPARAM_HUNG_TASK_PANIC
1128 bool "Panic (Reboot) On Hung Tasks"
1129 depends on DETECT_HUNG_TASK
1131 Say Y here to enable the kernel to panic on "hung tasks",
1132 which are bugs that cause the kernel to leave a task stuck
1133 in uninterruptible "D" state.
1135 The panic can be used in combination with panic_timeout,
1136 to cause the system to reboot automatically after a
1137 hung task has been detected. This feature is useful for
1138 high-availability systems that have uptime guarantees and
1139 where a hung tasks must be resolved ASAP.
1144 bool "Detect Workqueue Stalls"
1145 depends on DEBUG_KERNEL
1147 Say Y here to enable stall detection on workqueues. If a
1148 worker pool doesn't make forward progress on a pending work
1149 item for over a given amount of time, 30s by default, a
1150 warning message is printed along with dump of workqueue
1151 state. This can be configured through kernel parameter
1152 "workqueue.watchdog_thresh" and its sysfs counterpart.
1155 tristate "Test module to generate lockups"
1158 This builds the "test_lockup" module that helps to make sure
1159 that watchdogs and lockup detectors are working properly.
1161 Depending on module parameters it could emulate soft or hard
1162 lockup, "hung task", or locking arbitrary lock for a long time.
1163 Also it could generate series of lockups with cooling-down periods.
1167 endmenu # "Debug lockups and hangs"
1169 menu "Scheduler Debugging"
1172 bool "Collect scheduler debugging info"
1173 depends on DEBUG_KERNEL && PROC_FS
1176 If you say Y here, the /proc/sched_debug file will be provided
1177 that can help debug the scheduler. The runtime overhead of this
1185 bool "Collect scheduler statistics"
1186 depends on DEBUG_KERNEL && PROC_FS
1189 If you say Y here, additional code will be inserted into the
1190 scheduler and related routines to collect statistics about
1191 scheduler behavior and provide them in /proc/schedstat. These
1192 stats may be useful for both tuning and debugging the scheduler
1193 If you aren't debugging the scheduler or trying to tune a specific
1194 application, you can say N to avoid the very slight overhead
1199 config DEBUG_TIMEKEEPING
1200 bool "Enable extra timekeeping sanity checking"
1202 This option will enable additional timekeeping sanity checks
1203 which may be helpful when diagnosing issues where timekeeping
1204 problems are suspected.
1206 This may include checks in the timekeeping hotpaths, so this
1207 option may have a (very small) performance impact to some
1212 config DEBUG_PREEMPT
1213 bool "Debug preemptible kernel"
1214 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1217 If you say Y here then the kernel will use a debug variant of the
1218 commonly used smp_processor_id() function and will print warnings
1219 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1220 will detect preemption count underflows.
1222 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1224 config LOCK_DEBUGGING_SUPPORT
1226 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1229 config PROVE_LOCKING
1230 bool "Lock debugging: prove locking correctness"
1231 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1233 select DEBUG_SPINLOCK
1234 select DEBUG_MUTEXES if !PREEMPT_RT
1235 select DEBUG_RT_MUTEXES if RT_MUTEXES
1237 select DEBUG_WW_MUTEX_SLOWPATH
1238 select DEBUG_LOCK_ALLOC
1239 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1240 select TRACE_IRQFLAGS
1243 This feature enables the kernel to prove that all locking
1244 that occurs in the kernel runtime is mathematically
1245 correct: that under no circumstance could an arbitrary (and
1246 not yet triggered) combination of observed locking
1247 sequences (on an arbitrary number of CPUs, running an
1248 arbitrary number of tasks and interrupt contexts) cause a
1251 In short, this feature enables the kernel to report locking
1252 related deadlocks before they actually occur.
1254 The proof does not depend on how hard and complex a
1255 deadlock scenario would be to trigger: how many
1256 participant CPUs, tasks and irq-contexts would be needed
1257 for it to trigger. The proof also does not depend on
1258 timing: if a race and a resulting deadlock is possible
1259 theoretically (no matter how unlikely the race scenario
1260 is), it will be proven so and will immediately be
1261 reported by the kernel (once the event is observed that
1262 makes the deadlock theoretically possible).
1264 If a deadlock is impossible (i.e. the locking rules, as
1265 observed by the kernel, are mathematically correct), the
1266 kernel reports nothing.
1268 NOTE: this feature can also be enabled for rwlocks, mutexes
1269 and rwsems - in which case all dependencies between these
1270 different locking variants are observed and mapped too, and
1271 the proof of observed correctness is also maintained for an
1272 arbitrary combination of these separate locking variants.
1274 For more details, see Documentation/locking/lockdep-design.rst.
1276 config PROVE_RAW_LOCK_NESTING
1277 bool "Enable raw_spinlock - spinlock nesting checks"
1278 depends on PROVE_LOCKING
1281 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1282 that the lock nesting rules for PREEMPT_RT enabled kernels are
1285 NOTE: There are known nesting problems. So if you enable this
1286 option expect lockdep splats until these problems have been fully
1287 addressed which is work in progress. This config switch allows to
1288 identify and analyze these problems. It will be removed and the
1289 check permanently enabled once the main issues have been fixed.
1291 If unsure, select N.
1294 bool "Lock usage statistics"
1295 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1297 select DEBUG_SPINLOCK
1298 select DEBUG_MUTEXES if !PREEMPT_RT
1299 select DEBUG_RT_MUTEXES if RT_MUTEXES
1300 select DEBUG_LOCK_ALLOC
1303 This feature enables tracking lock contention points
1305 For more details, see Documentation/locking/lockstat.rst
1307 This also enables lock events required by "perf lock",
1309 If you want to use "perf lock", you also need to turn on
1310 CONFIG_EVENT_TRACING.
1312 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1313 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1315 config DEBUG_RT_MUTEXES
1316 bool "RT Mutex debugging, deadlock detection"
1317 depends on DEBUG_KERNEL && RT_MUTEXES
1319 This allows rt mutex semantics violations and rt mutex related
1320 deadlocks (lockups) to be detected and reported automatically.
1322 config DEBUG_SPINLOCK
1323 bool "Spinlock and rw-lock debugging: basic checks"
1324 depends on DEBUG_KERNEL
1325 select UNINLINE_SPIN_UNLOCK
1327 Say Y here and build SMP to catch missing spinlock initialization
1328 and certain other kinds of spinlock errors commonly made. This is
1329 best used in conjunction with the NMI watchdog so that spinlock
1330 deadlocks are also debuggable.
1332 config DEBUG_MUTEXES
1333 bool "Mutex debugging: basic checks"
1334 depends on DEBUG_KERNEL && !PREEMPT_RT
1336 This feature allows mutex semantics violations to be detected and
1339 config DEBUG_WW_MUTEX_SLOWPATH
1340 bool "Wait/wound mutex debugging: Slowpath testing"
1341 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1342 select DEBUG_LOCK_ALLOC
1343 select DEBUG_SPINLOCK
1344 select DEBUG_MUTEXES if !PREEMPT_RT
1345 select DEBUG_RT_MUTEXES if PREEMPT_RT
1347 This feature enables slowpath testing for w/w mutex users by
1348 injecting additional -EDEADLK wound/backoff cases. Together with
1349 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1350 will test all possible w/w mutex interface abuse with the
1351 exception of simply not acquiring all the required locks.
1352 Note that this feature can introduce significant overhead, so
1353 it really should not be enabled in a production or distro kernel,
1354 even a debug kernel. If you are a driver writer, enable it. If
1355 you are a distro, do not.
1358 bool "RW Semaphore debugging: basic checks"
1359 depends on DEBUG_KERNEL
1361 This debugging feature allows mismatched rw semaphore locks
1362 and unlocks to be detected and reported.
1364 config DEBUG_LOCK_ALLOC
1365 bool "Lock debugging: detect incorrect freeing of live locks"
1366 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1367 select DEBUG_SPINLOCK
1368 select DEBUG_MUTEXES if !PREEMPT_RT
1369 select DEBUG_RT_MUTEXES if RT_MUTEXES
1372 This feature will check whether any held lock (spinlock, rwlock,
1373 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1374 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1375 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1376 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1377 held during task exit.
1381 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1386 config LOCKDEP_SMALL
1390 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1391 depends on LOCKDEP && !LOCKDEP_SMALL
1395 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1397 config LOCKDEP_CHAINS_BITS
1398 int "Bitsize for MAX_LOCKDEP_CHAINS"
1399 depends on LOCKDEP && !LOCKDEP_SMALL
1403 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1405 config LOCKDEP_STACK_TRACE_BITS
1406 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1407 depends on LOCKDEP && !LOCKDEP_SMALL
1411 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1413 config LOCKDEP_STACK_TRACE_HASH_BITS
1414 int "Bitsize for STACK_TRACE_HASH_SIZE"
1415 depends on LOCKDEP && !LOCKDEP_SMALL
1419 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1421 config LOCKDEP_CIRCULAR_QUEUE_BITS
1422 int "Bitsize for elements in circular_queue struct"
1427 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1429 config DEBUG_LOCKDEP
1430 bool "Lock dependency engine debugging"
1431 depends on DEBUG_KERNEL && LOCKDEP
1432 select DEBUG_IRQFLAGS
1434 If you say Y here, the lock dependency engine will do
1435 additional runtime checks to debug itself, at the price
1436 of more runtime overhead.
1438 config DEBUG_ATOMIC_SLEEP
1439 bool "Sleep inside atomic section checking"
1440 select PREEMPT_COUNT
1441 depends on DEBUG_KERNEL
1442 depends on !ARCH_NO_PREEMPT
1444 If you say Y here, various routines which may sleep will become very
1445 noisy if they are called inside atomic sections: when a spinlock is
1446 held, inside an rcu read side critical section, inside preempt disabled
1447 sections, inside an interrupt, etc...
1449 config DEBUG_LOCKING_API_SELFTESTS
1450 bool "Locking API boot-time self-tests"
1451 depends on DEBUG_KERNEL
1453 Say Y here if you want the kernel to run a short self-test during
1454 bootup. The self-test checks whether common types of locking bugs
1455 are detected by debugging mechanisms or not. (if you disable
1456 lock debugging then those bugs won't be detected of course.)
1457 The following locking APIs are covered: spinlocks, rwlocks,
1460 config LOCK_TORTURE_TEST
1461 tristate "torture tests for locking"
1462 depends on DEBUG_KERNEL
1465 This option provides a kernel module that runs torture tests
1466 on kernel locking primitives. The kernel module may be built
1467 after the fact on the running kernel to be tested, if desired.
1469 Say Y here if you want kernel locking-primitive torture tests
1470 to be built into the kernel.
1471 Say M if you want these torture tests to build as a module.
1472 Say N if you are unsure.
1474 config WW_MUTEX_SELFTEST
1475 tristate "Wait/wound mutex selftests"
1477 This option provides a kernel module that runs tests on the
1478 on the struct ww_mutex locking API.
1480 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1481 with this test harness.
1483 Say M if you want these self tests to build as a module.
1484 Say N if you are unsure.
1486 config SCF_TORTURE_TEST
1487 tristate "torture tests for smp_call_function*()"
1488 depends on DEBUG_KERNEL
1491 This option provides a kernel module that runs torture tests
1492 on the smp_call_function() family of primitives. The kernel
1493 module may be built after the fact on the running kernel to
1494 be tested, if desired.
1496 config CSD_LOCK_WAIT_DEBUG
1497 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1498 depends on DEBUG_KERNEL
1502 This option enables debug prints when CPUs are slow to respond
1503 to the smp_call_function*() IPI wrappers. These debug prints
1504 include the IPI handler function currently executing (if any)
1505 and relevant stack traces.
1507 endmenu # lock debugging
1509 config TRACE_IRQFLAGS
1510 depends on TRACE_IRQFLAGS_SUPPORT
1513 Enables hooks to interrupt enabling and disabling for
1514 either tracing or lock debugging.
1516 config TRACE_IRQFLAGS_NMI
1518 depends on TRACE_IRQFLAGS
1519 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1521 config DEBUG_IRQFLAGS
1522 bool "Debug IRQ flag manipulation"
1524 Enables checks for potentially unsafe enabling or disabling of
1525 interrupts, such as calling raw_local_irq_restore() when interrupts
1529 bool "Stack backtrace support"
1530 depends on STACKTRACE_SUPPORT
1532 This option causes the kernel to create a /proc/pid/stack for
1533 every process, showing its current stack trace.
1534 It is also used by various kernel debugging features that require
1535 stack trace generation.
1537 config WARN_ALL_UNSEEDED_RANDOM
1538 bool "Warn for all uses of unseeded randomness"
1541 Some parts of the kernel contain bugs relating to their use of
1542 cryptographically secure random numbers before it's actually possible
1543 to generate those numbers securely. This setting ensures that these
1544 flaws don't go unnoticed, by enabling a message, should this ever
1545 occur. This will allow people with obscure setups to know when things
1546 are going wrong, so that they might contact developers about fixing
1549 Unfortunately, on some models of some architectures getting
1550 a fully seeded CRNG is extremely difficult, and so this can
1551 result in dmesg getting spammed for a surprisingly long
1552 time. This is really bad from a security perspective, and
1553 so architecture maintainers really need to do what they can
1554 to get the CRNG seeded sooner after the system is booted.
1555 However, since users cannot do anything actionable to
1556 address this, by default this option is disabled.
1558 Say Y here if you want to receive warnings for all uses of
1559 unseeded randomness. This will be of use primarily for
1560 those developers interested in improving the security of
1561 Linux kernels running on their architecture (or
1564 config DEBUG_KOBJECT
1565 bool "kobject debugging"
1566 depends on DEBUG_KERNEL
1568 If you say Y here, some extra kobject debugging messages will be sent
1571 config DEBUG_KOBJECT_RELEASE
1572 bool "kobject release debugging"
1573 depends on DEBUG_OBJECTS_TIMERS
1575 kobjects are reference counted objects. This means that their
1576 last reference count put is not predictable, and the kobject can
1577 live on past the point at which a driver decides to drop its
1578 initial reference to the kobject gained on allocation. An
1579 example of this would be a struct device which has just been
1582 However, some buggy drivers assume that after such an operation,
1583 the memory backing the kobject can be immediately freed. This
1584 goes completely against the principles of a refcounted object.
1586 If you say Y here, the kernel will delay the release of kobjects
1587 on the last reference count to improve the visibility of this
1588 kind of kobject release bug.
1590 config HAVE_DEBUG_BUGVERBOSE
1593 menu "Debug kernel data structures"
1596 bool "Debug linked list manipulation"
1597 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1599 Enable this to turn on extended checks in the linked-list
1605 bool "Debug priority linked list manipulation"
1606 depends on DEBUG_KERNEL
1608 Enable this to turn on extended checks in the priority-ordered
1609 linked-list (plist) walking routines. This checks the entire
1610 list multiple times during each manipulation.
1615 bool "Debug SG table operations"
1616 depends on DEBUG_KERNEL
1618 Enable this to turn on checks on scatter-gather tables. This can
1619 help find problems with drivers that do not properly initialize
1624 config DEBUG_NOTIFIERS
1625 bool "Debug notifier call chains"
1626 depends on DEBUG_KERNEL
1628 Enable this to turn on sanity checking for notifier call chains.
1629 This is most useful for kernel developers to make sure that
1630 modules properly unregister themselves from notifier chains.
1631 This is a relatively cheap check but if you care about maximum
1634 config BUG_ON_DATA_CORRUPTION
1635 bool "Trigger a BUG when data corruption is detected"
1638 Select this option if the kernel should BUG when it encounters
1639 data corruption in kernel memory structures when they get checked
1646 config DEBUG_CREDENTIALS
1647 bool "Debug credential management"
1648 depends on DEBUG_KERNEL
1650 Enable this to turn on some debug checking for credential
1651 management. The additional code keeps track of the number of
1652 pointers from task_structs to any given cred struct, and checks to
1653 see that this number never exceeds the usage count of the cred
1656 Furthermore, if SELinux is enabled, this also checks that the
1657 security pointer in the cred struct is never seen to be invalid.
1661 source "kernel/rcu/Kconfig.debug"
1663 config DEBUG_WQ_FORCE_RR_CPU
1664 bool "Force round-robin CPU selection for unbound work items"
1665 depends on DEBUG_KERNEL
1668 Workqueue used to implicitly guarantee that work items queued
1669 without explicit CPU specified are put on the local CPU. This
1670 guarantee is no longer true and while local CPU is still
1671 preferred work items may be put on foreign CPUs. Kernel
1672 parameter "workqueue.debug_force_rr_cpu" is added to force
1673 round-robin CPU selection to flush out usages which depend on the
1674 now broken guarantee. This config option enables the debug
1675 feature by default. When enabled, memory and cache locality will
1678 config CPU_HOTPLUG_STATE_CONTROL
1679 bool "Enable CPU hotplug state control"
1680 depends on DEBUG_KERNEL
1681 depends on HOTPLUG_CPU
1684 Allows to write steps between "offline" and "online" to the CPUs
1685 sysfs target file so states can be stepped granular. This is a debug
1686 option for now as the hotplug machinery cannot be stopped and
1687 restarted at arbitrary points yet.
1689 Say N if your are unsure.
1692 bool "Latency measuring infrastructure"
1693 depends on DEBUG_KERNEL
1694 depends on STACKTRACE_SUPPORT
1696 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1702 Enable this option if you want to use the LatencyTOP tool
1703 to find out which userspace is blocking on what kernel operations.
1705 source "kernel/trace/Kconfig"
1707 config PROVIDE_OHCI1394_DMA_INIT
1708 bool "Remote debugging over FireWire early on boot"
1709 depends on PCI && X86
1711 If you want to debug problems which hang or crash the kernel early
1712 on boot and the crashing machine has a FireWire port, you can use
1713 this feature to remotely access the memory of the crashed machine
1714 over FireWire. This employs remote DMA as part of the OHCI1394
1715 specification which is now the standard for FireWire controllers.
1717 With remote DMA, you can monitor the printk buffer remotely using
1718 firescope and access all memory below 4GB using fireproxy from gdb.
1719 Even controlling a kernel debugger is possible using remote DMA.
1723 If ohci1394_dma=early is used as boot parameter, it will initialize
1724 all OHCI1394 controllers which are found in the PCI config space.
1726 As all changes to the FireWire bus such as enabling and disabling
1727 devices cause a bus reset and thereby disable remote DMA for all
1728 devices, be sure to have the cable plugged and FireWire enabled on
1729 the debugging host before booting the debug target for debugging.
1731 This code (~1k) is freed after boot. By then, the firewire stack
1732 in charge of the OHCI-1394 controllers should be used instead.
1734 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1736 source "samples/Kconfig"
1738 config ARCH_HAS_DEVMEM_IS_ALLOWED
1741 config STRICT_DEVMEM
1742 bool "Filter access to /dev/mem"
1743 depends on MMU && DEVMEM
1744 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1745 default y if PPC || X86 || ARM64
1747 If this option is disabled, you allow userspace (root) access to all
1748 of memory, including kernel and userspace memory. Accidental
1749 access to this is obviously disastrous, but specific access can
1750 be used by people debugging the kernel. Note that with PAT support
1751 enabled, even in this case there are restrictions on /dev/mem
1752 use due to the cache aliasing requirements.
1754 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1755 file only allows userspace access to PCI space and the BIOS code and
1756 data regions. This is sufficient for dosemu and X and all common
1761 config IO_STRICT_DEVMEM
1762 bool "Filter I/O access to /dev/mem"
1763 depends on STRICT_DEVMEM
1765 If this option is disabled, you allow userspace (root) access to all
1766 io-memory regardless of whether a driver is actively using that
1767 range. Accidental access to this is obviously disastrous, but
1768 specific access can be used by people debugging kernel drivers.
1770 If this option is switched on, the /dev/mem file only allows
1771 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1772 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1773 if the driver using a given range cannot be disabled.
1777 menu "$(SRCARCH) Debugging"
1779 source "arch/$(SRCARCH)/Kconfig.debug"
1783 menu "Kernel Testing and Coverage"
1785 source "lib/kunit/Kconfig"
1787 config NOTIFIER_ERROR_INJECTION
1788 tristate "Notifier error injection"
1789 depends on DEBUG_KERNEL
1792 This option provides the ability to inject artificial errors to
1793 specified notifier chain callbacks. It is useful to test the error
1794 handling of notifier call chain failures.
1798 config PM_NOTIFIER_ERROR_INJECT
1799 tristate "PM notifier error injection module"
1800 depends on PM && NOTIFIER_ERROR_INJECTION
1801 default m if PM_DEBUG
1803 This option provides the ability to inject artificial errors to
1804 PM notifier chain callbacks. It is controlled through debugfs
1805 interface /sys/kernel/debug/notifier-error-inject/pm
1807 If the notifier call chain should be failed with some events
1808 notified, write the error code to "actions/<notifier event>/error".
1810 Example: Inject PM suspend error (-12 = -ENOMEM)
1812 # cd /sys/kernel/debug/notifier-error-inject/pm/
1813 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1814 # echo mem > /sys/power/state
1815 bash: echo: write error: Cannot allocate memory
1817 To compile this code as a module, choose M here: the module will
1818 be called pm-notifier-error-inject.
1822 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1823 tristate "OF reconfig notifier error injection module"
1824 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1826 This option provides the ability to inject artificial errors to
1827 OF reconfig notifier chain callbacks. It is controlled
1828 through debugfs interface under
1829 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1831 If the notifier call chain should be failed with some events
1832 notified, write the error code to "actions/<notifier event>/error".
1834 To compile this code as a module, choose M here: the module will
1835 be called of-reconfig-notifier-error-inject.
1839 config NETDEV_NOTIFIER_ERROR_INJECT
1840 tristate "Netdev notifier error injection module"
1841 depends on NET && NOTIFIER_ERROR_INJECTION
1843 This option provides the ability to inject artificial errors to
1844 netdevice notifier chain callbacks. It is controlled through debugfs
1845 interface /sys/kernel/debug/notifier-error-inject/netdev
1847 If the notifier call chain should be failed with some events
1848 notified, write the error code to "actions/<notifier event>/error".
1850 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1852 # cd /sys/kernel/debug/notifier-error-inject/netdev
1853 # echo -22 > actions/NETDEV_CHANGEMTU/error
1854 # ip link set eth0 mtu 1024
1855 RTNETLINK answers: Invalid argument
1857 To compile this code as a module, choose M here: the module will
1858 be called netdev-notifier-error-inject.
1862 config FUNCTION_ERROR_INJECTION
1864 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1866 config FAULT_INJECTION
1867 bool "Fault-injection framework"
1868 depends on DEBUG_KERNEL
1870 Provide fault-injection framework.
1871 For more details, see Documentation/fault-injection/.
1874 bool "Fault-injection capability for kmalloc"
1875 depends on FAULT_INJECTION
1876 depends on SLAB || SLUB
1878 Provide fault-injection capability for kmalloc.
1880 config FAIL_PAGE_ALLOC
1881 bool "Fault-injection capability for alloc_pages()"
1882 depends on FAULT_INJECTION
1884 Provide fault-injection capability for alloc_pages().
1886 config FAULT_INJECTION_USERCOPY
1887 bool "Fault injection capability for usercopy functions"
1888 depends on FAULT_INJECTION
1890 Provides fault-injection capability to inject failures
1891 in usercopy functions (copy_from_user(), get_user(), ...).
1893 config FAIL_MAKE_REQUEST
1894 bool "Fault-injection capability for disk IO"
1895 depends on FAULT_INJECTION && BLOCK
1897 Provide fault-injection capability for disk IO.
1899 config FAIL_IO_TIMEOUT
1900 bool "Fault-injection capability for faking disk interrupts"
1901 depends on FAULT_INJECTION && BLOCK
1903 Provide fault-injection capability on end IO handling. This
1904 will make the block layer "forget" an interrupt as configured,
1905 thus exercising the error handling.
1907 Only works with drivers that use the generic timeout handling,
1908 for others it won't do anything.
1911 bool "Fault-injection capability for futexes"
1913 depends on FAULT_INJECTION && FUTEX
1915 Provide fault-injection capability for futexes.
1917 config FAULT_INJECTION_DEBUG_FS
1918 bool "Debugfs entries for fault-injection capabilities"
1919 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1921 Enable configuration of fault-injection capabilities via debugfs.
1923 config FAIL_FUNCTION
1924 bool "Fault-injection capability for functions"
1925 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1927 Provide function-based fault-injection capability.
1928 This will allow you to override a specific function with a return
1929 with given return value. As a result, function caller will see
1930 an error value and have to handle it. This is useful to test the
1931 error handling in various subsystems.
1933 config FAIL_MMC_REQUEST
1934 bool "Fault-injection capability for MMC IO"
1935 depends on FAULT_INJECTION_DEBUG_FS && MMC
1937 Provide fault-injection capability for MMC IO.
1938 This will make the mmc core return data errors. This is
1939 useful to test the error handling in the mmc block device
1940 and to test how the mmc host driver handles retries from
1944 bool "Fault-injection capability for SunRPC"
1945 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
1947 Provide fault-injection capability for SunRPC and
1950 config FAULT_INJECTION_STACKTRACE_FILTER
1951 bool "stacktrace filter for fault-injection capabilities"
1952 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1955 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1957 Provide stacktrace filter for fault-injection capabilities
1959 config ARCH_HAS_KCOV
1962 An architecture should select this when it can successfully
1963 build and run with CONFIG_KCOV. This typically requires
1964 disabling instrumentation for some early boot code.
1966 config CC_HAS_SANCOV_TRACE_PC
1967 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1971 bool "Code coverage for fuzzing"
1972 depends on ARCH_HAS_KCOV
1973 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1974 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
1975 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
1977 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1978 select OBJTOOL if HAVE_NOINSTR_HACK
1980 KCOV exposes kernel code coverage information in a form suitable
1981 for coverage-guided fuzzing (randomized testing).
1983 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1984 different machines and across reboots. If you need stable PC values,
1985 disable RANDOMIZE_BASE.
1987 For more details, see Documentation/dev-tools/kcov.rst.
1989 config KCOV_ENABLE_COMPARISONS
1990 bool "Enable comparison operands collection by KCOV"
1992 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1994 KCOV also exposes operands of every comparison in the instrumented
1995 code along with operand sizes and PCs of the comparison instructions.
1996 These operands can be used by fuzzing engines to improve the quality
1997 of fuzzing coverage.
1999 config KCOV_INSTRUMENT_ALL
2000 bool "Instrument all code by default"
2004 If you are doing generic system call fuzzing (like e.g. syzkaller),
2005 then you will want to instrument the whole kernel and you should
2006 say y here. If you are doing more targeted fuzzing (like e.g.
2007 filesystem fuzzing with AFL) then you will want to enable coverage
2008 for more specific subsets of files, and should say n here.
2010 config KCOV_IRQ_AREA_SIZE
2011 hex "Size of interrupt coverage collection area in words"
2015 KCOV uses preallocated per-cpu areas to collect coverage from
2016 soft interrupts. This specifies the size of those areas in the
2017 number of unsigned long words.
2019 menuconfig RUNTIME_TESTING_MENU
2020 bool "Runtime Testing"
2023 if RUNTIME_TESTING_MENU
2026 tristate "Linux Kernel Dump Test Tool Module"
2029 This module enables testing of the different dumping mechanisms by
2030 inducing system failures at predefined crash points.
2031 If you don't need it: say N
2032 Choose M here to compile this code as a module. The module will be
2035 Documentation on how to use the module can be found in
2036 Documentation/fault-injection/provoke-crashes.rst
2038 config CPUMASK_KUNIT_TEST
2039 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2041 default KUNIT_ALL_TESTS
2043 Enable to turn on cpumask tests, running at boot or module load time.
2045 For more information on KUnit and unit tests in general, please refer
2046 to the KUnit documentation in Documentation/dev-tools/kunit/.
2050 config TEST_LIST_SORT
2051 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2053 default KUNIT_ALL_TESTS
2055 Enable this to turn on 'list_sort()' function test. This test is
2056 executed only once during system boot (so affects only boot time),
2057 or at module load time.
2061 config TEST_MIN_HEAP
2062 tristate "Min heap test"
2063 depends on DEBUG_KERNEL || m
2065 Enable this to turn on min heap function tests. This test is
2066 executed only once during system boot (so affects only boot time),
2067 or at module load time.
2072 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2074 default KUNIT_ALL_TESTS
2076 This option enables the self-test function of 'sort()' at boot,
2077 or at module load time.
2082 tristate "64bit/32bit division and modulo test"
2083 depends on DEBUG_KERNEL || m
2085 Enable this to turn on 'do_div()' function test. This test is
2086 executed only once during system boot (so affects only boot time),
2087 or at module load time.
2091 config KPROBES_SANITY_TEST
2092 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2093 depends on DEBUG_KERNEL
2096 default KUNIT_ALL_TESTS
2098 This option provides for testing basic kprobes functionality on
2099 boot. Samples of kprobe and kretprobe are inserted and
2100 verified for functionality.
2102 Say N if you are unsure.
2104 config FPROBE_SANITY_TEST
2105 bool "Self test for fprobe"
2106 depends on DEBUG_KERNEL
2110 This option will enable testing the fprobe when the system boot.
2111 A series of tests are made to verify that the fprobe is functioning
2114 Say N if you are unsure.
2116 config BACKTRACE_SELF_TEST
2117 tristate "Self test for the backtrace code"
2118 depends on DEBUG_KERNEL
2120 This option provides a kernel module that can be used to test
2121 the kernel stack backtrace code. This option is not useful
2122 for distributions or general kernels, but only for kernel
2123 developers working on architecture code.
2125 Note that if you want to also test saved backtraces, you will
2126 have to enable STACKTRACE as well.
2128 Say N if you are unsure.
2130 config TEST_REF_TRACKER
2131 tristate "Self test for reference tracker"
2132 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2135 This option provides a kernel module performing tests
2136 using reference tracker infrastructure.
2138 Say N if you are unsure.
2141 tristate "Red-Black tree test"
2142 depends on DEBUG_KERNEL
2144 A benchmark measuring the performance of the rbtree library.
2145 Also includes rbtree invariant checks.
2147 config REED_SOLOMON_TEST
2148 tristate "Reed-Solomon library test"
2149 depends on DEBUG_KERNEL || m
2151 select REED_SOLOMON_ENC16
2152 select REED_SOLOMON_DEC16
2154 This option enables the self-test function of rslib at boot,
2155 or at module load time.
2159 config INTERVAL_TREE_TEST
2160 tristate "Interval tree test"
2161 depends on DEBUG_KERNEL
2162 select INTERVAL_TREE
2164 A benchmark measuring the performance of the interval tree library
2167 tristate "Per cpu operations test"
2168 depends on m && DEBUG_KERNEL
2170 Enable this option to build test module which validates per-cpu
2175 config ATOMIC64_SELFTEST
2176 tristate "Perform an atomic64_t self-test"
2178 Enable this option to test the atomic64_t functions at boot or
2179 at module load time.
2183 config ASYNC_RAID6_TEST
2184 tristate "Self test for hardware accelerated raid6 recovery"
2185 depends on ASYNC_RAID6_RECOV
2188 This is a one-shot self test that permutes through the
2189 recovery of all the possible two disk failure scenarios for a
2190 N-disk array. Recovery is performed with the asynchronous
2191 raid6 recovery routines, and will optionally use an offload
2192 engine if one is available.
2197 tristate "Test functions located in the hexdump module at runtime"
2199 config STRING_SELFTEST
2200 tristate "Test string functions at runtime"
2202 config TEST_STRING_HELPERS
2203 tristate "Test functions located in the string_helpers module at runtime"
2206 tristate "Test strscpy*() family of functions at runtime"
2209 tristate "Test kstrto*() family of functions at runtime"
2212 tristate "Test printf() family of functions at runtime"
2215 tristate "Test scanf() family of functions at runtime"
2218 tristate "Test bitmap_*() family of functions at runtime"
2220 Enable this option to test the bitmap functions at boot.
2225 tristate "Test functions located in the uuid module at runtime"
2228 tristate "Test the XArray code at runtime"
2230 config TEST_RHASHTABLE
2231 tristate "Perform selftest on resizable hash table"
2233 Enable this option to test the rhashtable functions at boot.
2238 tristate "Perform selftest on siphash functions"
2240 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2241 functions on boot (or module load).
2243 This is intended to help people writing architecture-specific
2244 optimized versions. If unsure, say N.
2247 tristate "Perform selftest on IDA functions"
2250 tristate "Perform selftest on priority array manager"
2253 Enable this option to test priority array manager on boot
2258 config TEST_IRQ_TIMINGS
2259 bool "IRQ timings selftest"
2260 depends on IRQ_TIMINGS
2262 Enable this option to test the irq timings code on boot.
2267 tristate "Test module loading with 'hello world' module"
2270 This builds the "test_module" module that emits "Hello, world"
2271 on printk when loaded. It is designed to be used for basic
2272 evaluation of the module loading subsystem (for example when
2273 validating module verification). It lacks any extra dependencies,
2274 and will not normally be loaded by the system unless explicitly
2280 tristate "Test module for compilation of bitops operations"
2283 This builds the "test_bitops" module that is much like the
2284 TEST_LKM module except that it does a basic exercise of the
2285 set/clear_bit macros and get_count_order/long to make sure there are
2286 no compiler warnings from C=1 sparse checker or -Wextra
2287 compilations. It has no dependencies and doesn't run or load unless
2288 explicitly requested by name. for example: modprobe test_bitops.
2293 tristate "Test module for stress/performance analysis of vmalloc allocator"
2298 This builds the "test_vmalloc" module that should be used for
2299 stress and performance analysis. So, any new change for vmalloc
2300 subsystem can be evaluated from performance and stability point
2305 config TEST_USER_COPY
2306 tristate "Test user/kernel boundary protections"
2309 This builds the "test_user_copy" module that runs sanity checks
2310 on the copy_to/from_user infrastructure, making sure basic
2311 user/kernel boundary testing is working. If it fails to load,
2312 a regression has been detected in the user/kernel memory boundary
2318 tristate "Test BPF filter functionality"
2321 This builds the "test_bpf" module that runs various test vectors
2322 against the BPF interpreter or BPF JIT compiler depending on the
2323 current setting. This is in particular useful for BPF JIT compiler
2324 development, but also to run regression tests against changes in
2325 the interpreter code. It also enables test stubs for eBPF maps and
2326 verifier used by user space verifier testsuite.
2330 config TEST_BLACKHOLE_DEV
2331 tristate "Test blackhole netdev functionality"
2334 This builds the "test_blackhole_dev" module that validates the
2335 data path through this blackhole netdev.
2339 config FIND_BIT_BENCHMARK
2340 tristate "Test find_bit functions"
2342 This builds the "test_find_bit" module that measure find_*_bit()
2343 functions performance.
2347 config TEST_FIRMWARE
2348 tristate "Test firmware loading via userspace interface"
2349 depends on FW_LOADER
2351 This builds the "test_firmware" module that creates a userspace
2352 interface for testing firmware loading. This can be used to
2353 control the triggering of firmware loading without needing an
2354 actual firmware-using device. The contents can be rechecked by
2360 tristate "sysctl test driver"
2361 depends on PROC_SYSCTL
2363 This builds the "test_sysctl" module. This driver enables to test the
2364 proc sysctl interfaces available to drivers safely without affecting
2365 production knobs which might alter system functionality.
2369 config BITFIELD_KUNIT
2370 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2372 default KUNIT_ALL_TESTS
2374 Enable this option to test the bitfield functions at boot.
2376 KUnit tests run during boot and output the results to the debug log
2377 in TAP format (http://testanything.org/). Only useful for kernel devs
2378 running the KUnit test harness, and not intended for inclusion into a
2381 For more information on KUnit and unit tests in general please refer
2382 to the KUnit documentation in Documentation/dev-tools/kunit/.
2386 config HASH_KUNIT_TEST
2387 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2389 default KUNIT_ALL_TESTS
2391 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2392 integer (<linux/hash.h>) hash functions on boot.
2394 KUnit tests run during boot and output the results to the debug log
2395 in TAP format (https://testanything.org/). Only useful for kernel devs
2396 running the KUnit test harness, and not intended for inclusion into a
2399 For more information on KUnit and unit tests in general please refer
2400 to the KUnit documentation in Documentation/dev-tools/kunit/.
2402 This is intended to help people writing architecture-specific
2403 optimized versions. If unsure, say N.
2405 config RESOURCE_KUNIT_TEST
2406 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2408 default KUNIT_ALL_TESTS
2410 This builds the resource API unit test.
2411 Tests the logic of API provided by resource.c and ioport.h.
2412 For more information on KUnit and unit tests in general please refer
2413 to the KUnit documentation in Documentation/dev-tools/kunit/.
2417 config SYSCTL_KUNIT_TEST
2418 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2420 default KUNIT_ALL_TESTS
2422 This builds the proc sysctl unit test, which runs on boot.
2423 Tests the API contract and implementation correctness of sysctl.
2424 For more information on KUnit and unit tests in general please refer
2425 to the KUnit documentation in Documentation/dev-tools/kunit/.
2429 config LIST_KUNIT_TEST
2430 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2432 default KUNIT_ALL_TESTS
2434 This builds the linked list KUnit test suite.
2435 It tests that the API and basic functionality of the list_head type
2436 and associated macros.
2438 KUnit tests run during boot and output the results to the debug log
2439 in TAP format (https://testanything.org/). Only useful for kernel devs
2440 running the KUnit test harness, and not intended for inclusion into a
2443 For more information on KUnit and unit tests in general please refer
2444 to the KUnit documentation in Documentation/dev-tools/kunit/.
2448 config LINEAR_RANGES_TEST
2449 tristate "KUnit test for linear_ranges"
2451 select LINEAR_RANGES
2453 This builds the linear_ranges unit test, which runs on boot.
2454 Tests the linear_ranges logic correctness.
2455 For more information on KUnit and unit tests in general please refer
2456 to the KUnit documentation in Documentation/dev-tools/kunit/.
2460 config CMDLINE_KUNIT_TEST
2461 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2463 default KUNIT_ALL_TESTS
2465 This builds the cmdline API unit test.
2466 Tests the logic of API provided by cmdline.c.
2467 For more information on KUnit and unit tests in general please refer
2468 to the KUnit documentation in Documentation/dev-tools/kunit/.
2473 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2475 default KUNIT_ALL_TESTS
2477 This builds the bits unit test.
2478 Tests the logic of macros defined in bits.h.
2479 For more information on KUnit and unit tests in general please refer
2480 to the KUnit documentation in Documentation/dev-tools/kunit/.
2484 config SLUB_KUNIT_TEST
2485 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2486 depends on SLUB_DEBUG && KUNIT
2487 default KUNIT_ALL_TESTS
2489 This builds SLUB allocator unit test.
2490 Tests SLUB cache debugging functionality.
2491 For more information on KUnit and unit tests in general please refer
2492 to the KUnit documentation in Documentation/dev-tools/kunit/.
2496 config RATIONAL_KUNIT_TEST
2497 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2498 depends on KUNIT && RATIONAL
2499 default KUNIT_ALL_TESTS
2501 This builds the rational math unit test.
2502 For more information on KUnit and unit tests in general please refer
2503 to the KUnit documentation in Documentation/dev-tools/kunit/.
2507 config MEMCPY_KUNIT_TEST
2508 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2510 default KUNIT_ALL_TESTS
2512 Builds unit tests for memcpy(), memmove(), and memset() functions.
2513 For more information on KUnit and unit tests in general please refer
2514 to the KUnit documentation in Documentation/dev-tools/kunit/.
2518 config IS_SIGNED_TYPE_KUNIT_TEST
2519 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2521 default KUNIT_ALL_TESTS
2523 Builds unit tests for the is_signed_type() macro.
2525 For more information on KUnit and unit tests in general please refer
2526 to the KUnit documentation in Documentation/dev-tools/kunit/.
2530 config OVERFLOW_KUNIT_TEST
2531 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2533 default KUNIT_ALL_TESTS
2535 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2538 For more information on KUnit and unit tests in general please refer
2539 to the KUnit documentation in Documentation/dev-tools/kunit/.
2543 config STACKINIT_KUNIT_TEST
2544 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2546 default KUNIT_ALL_TESTS
2548 Test if the kernel is zero-initializing stack variables and
2549 padding. Coverage is controlled by compiler flags,
2550 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2551 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2552 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2554 config FORTIFY_KUNIT_TEST
2555 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2556 depends on KUNIT && FORTIFY_SOURCE
2557 default KUNIT_ALL_TESTS
2559 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2560 by the str*() and mem*() family of functions. For testing runtime
2561 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2563 config HW_BREAKPOINT_KUNIT_TEST
2564 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2565 depends on HAVE_HW_BREAKPOINT
2567 default KUNIT_ALL_TESTS
2569 Tests for hw_breakpoint constraints accounting.
2574 tristate "udelay test driver"
2576 This builds the "udelay_test" module that helps to make sure
2577 that udelay() is working properly.
2581 config TEST_STATIC_KEYS
2582 tristate "Test static keys"
2585 Test the static key interfaces.
2589 config TEST_DYNAMIC_DEBUG
2590 tristate "Test DYNAMIC_DEBUG"
2591 depends on DYNAMIC_DEBUG
2593 This module registers a tracer callback to count enabled
2594 pr_debugs in a 'do_debugging' function, then alters their
2595 enablements, calls the function, and compares counts.
2600 tristate "kmod stress tester"
2602 depends on NETDEVICES && NET_CORE && INET # for TUN
2604 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2610 Test the kernel's module loading mechanism: kmod. kmod implements
2611 support to load modules using the Linux kernel's usermode helper.
2612 This test provides a series of tests against kmod.
2614 Although technically you can either build test_kmod as a module or
2615 into the kernel we disallow building it into the kernel since
2616 it stress tests request_module() and this will very likely cause
2617 some issues by taking over precious threads available from other
2618 module load requests, ultimately this could be fatal.
2622 tools/testing/selftests/kmod/kmod.sh --help
2626 config TEST_DEBUG_VIRTUAL
2627 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2628 depends on DEBUG_VIRTUAL
2630 Test the kernel's ability to detect incorrect calls to
2631 virt_to_phys() done against the non-linear part of the
2632 kernel's virtual address map.
2636 config TEST_MEMCAT_P
2637 tristate "Test memcat_p() helper function"
2639 Test the memcat_p() helper for correctly merging two
2640 pointer arrays together.
2644 config TEST_LIVEPATCH
2645 tristate "Test livepatching"
2647 depends on DYNAMIC_DEBUG
2648 depends on LIVEPATCH
2651 Test kernel livepatching features for correctness. The tests will
2652 load test modules that will be livepatched in various scenarios.
2654 To run all the livepatching tests:
2656 make -C tools/testing/selftests TARGETS=livepatch run_tests
2658 Alternatively, individual tests may be invoked:
2660 tools/testing/selftests/livepatch/test-callbacks.sh
2661 tools/testing/selftests/livepatch/test-livepatch.sh
2662 tools/testing/selftests/livepatch/test-shadow-vars.sh
2667 tristate "Perform selftest on object aggreration manager"
2671 Enable this option to test object aggregation manager on boot
2675 tristate "Test heap/page initialization"
2677 Test if the kernel is zero-initializing heap and page allocations.
2678 This can be useful to test init_on_alloc and init_on_free features.
2683 tristate "Test HMM (Heterogeneous Memory Management)"
2684 depends on TRANSPARENT_HUGEPAGE
2685 depends on DEVICE_PRIVATE
2689 This is a pseudo device driver solely for testing HMM.
2690 Say M here if you want to build the HMM test module.
2691 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2695 config TEST_FREE_PAGES
2696 tristate "Test freeing pages"
2698 Test that a memory leak does not occur due to a race between
2699 freeing a block of pages and a speculative page reference.
2700 Loading this module is safe if your kernel has the bug fixed.
2701 If the bug is not fixed, it will leak gigabytes of memory and
2702 probably OOM your system.
2705 tristate "Test floating point operations in kernel space"
2706 depends on X86 && !KCOV_INSTRUMENT_ALL
2708 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2709 which will trigger a sequence of floating point operations. This is used
2710 for self-testing floating point control register setting in
2715 config TEST_CLOCKSOURCE_WATCHDOG
2716 tristate "Test clocksource watchdog in kernel space"
2717 depends on CLOCKSOURCE_WATCHDOG
2719 Enable this option to create a kernel module that will trigger
2720 a test of the clocksource watchdog. This module may be loaded
2721 via modprobe or insmod in which case it will run upon being
2722 loaded, or it may be built in, in which case it will run
2727 endif # RUNTIME_TESTING_MENU
2729 config ARCH_USE_MEMTEST
2732 An architecture should select this when it uses early_memtest()
2733 during boot process.
2737 depends on ARCH_USE_MEMTEST
2739 This option adds a kernel parameter 'memtest', which allows memtest
2740 to be set and executed.
2741 memtest=0, mean disabled; -- default
2742 memtest=1, mean do 1 test pattern;
2744 memtest=17, mean do 17 test patterns.
2745 If you are unsure how to answer this question, answer N.
2749 config HYPERV_TESTING
2750 bool "Microsoft Hyper-V driver testing"
2752 depends on HYPERV && DEBUG_FS
2754 Select this option to enable Hyper-V vmbus testing.
2756 endmenu # "Kernel Testing and Coverage"
2760 config RUST_DEBUG_ASSERTIONS
2761 bool "Debug assertions"
2764 Enables rustc's `-Cdebug-assertions` codegen option.
2766 This flag lets you turn `cfg(debug_assertions)` conditional
2767 compilation on or off. This can be used to enable extra debugging
2768 code in development but not in production. For example, it controls
2769 the behavior of the standard library's `debug_assert!` macro.
2771 Note that this will apply to all Rust code, including `core`.
2775 config RUST_OVERFLOW_CHECKS
2776 bool "Overflow checks"
2780 Enables rustc's `-Coverflow-checks` codegen option.
2782 This flag allows you to control the behavior of runtime integer
2783 overflow. When overflow-checks are enabled, a Rust panic will occur
2786 Note that this will apply to all Rust code, including `core`.
2792 source "Documentation/Kconfig"
2794 endmenu # Kernel hacking
projects / platform / kernel / linux-starfive.git / blob