1 # SPDX-License-Identifier: GPL-2.0-only
4 menu "printk and dmesg options"
7 bool "Show timing information on printks"
10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
22 bool "Show caller information on printks"
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
38 config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
49 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
54 Default loglevel to determine what will be printed on the console.
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
60 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
64 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
69 loglevel to use when "quiet" is passed on the kernel commandline.
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
75 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)"
80 Default log level for printk statements with no specified priority.
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
90 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
109 bool "Enable dynamic printk() support"
112 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
138 filename:lineno [module]function flags format
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
180 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
183 depends on (DEBUG_FS || PROC_FS)
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
191 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
200 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
209 endmenu # "printk and dmesg options"
212 bool "Kernel debugging"
214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems.
218 bool "Miscellaneous debug code"
220 depends on DEBUG_KERNEL
222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug option but isn't.
225 menu "Compile-time checks and compiler options"
230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice below, indicating that debug
232 information will be generated for build targets.
235 prompt "Debug information"
236 depends on DEBUG_KERNEL
238 Selecting something other than "None" results in a kernel image
239 that will include debugging info resulting in a larger kernel image.
240 This adds debug symbols to the kernel and modules (gcc -g), and
241 is needed if you intend to use kernel crashdump or binary object
242 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
244 Choose which version of DWARF debug info to emit. If unsure,
245 select "Toolchain default".
247 config DEBUG_INFO_NONE
248 bool "Disable debug information"
250 Do not build the kernel with debugging information, which will
251 result in a faster and smaller build.
253 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
254 bool "Rely on the toolchain's implicit default DWARF version"
257 The implicit default version of DWARF debug info produced by a
258 toolchain changes over time.
260 This can break consumers of the debug info that haven't upgraded to
261 support newer revisions, and prevent testing newer versions, but
262 those should be less common scenarios.
264 config DEBUG_INFO_DWARF4
265 bool "Generate DWARF Version 4 debuginfo"
268 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
270 If you have consumers of DWARF debug info that are not ready for
271 newer revisions of DWARF, you may wish to choose this or have your
274 config DEBUG_INFO_DWARF5
275 bool "Generate DWARF Version 5 debuginfo"
277 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
279 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
280 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
281 draft features until 7.0), and gdb 8.0+.
283 Changes to the structure of debug info in Version 5 allow for around
284 15-18% savings in resulting image and debug info section sizes as
285 compared to DWARF Version 4. DWARF Version 5 standardizes previous
286 extensions such as accelerators for symbol indexing and the format
287 for fission (.dwo/.dwp) files. Users may not want to select this
288 config if they rely on tooling that has not yet been updated to
289 support DWARF Version 5.
291 endchoice # "Debug information"
295 config DEBUG_INFO_REDUCED
296 bool "Reduce debugging information"
298 If you say Y here gcc is instructed to generate less debugging
299 information for structure types. This means that tools that
300 need full debugging information (like kgdb or systemtap) won't
301 be happy. But if you merely need debugging information to
302 resolve line numbers there is no loss. Advantage is that
303 build directory object sizes shrink dramatically over a full
304 DEBUG_INFO build and compile times are reduced too.
305 Only works with newer gcc versions.
307 config DEBUG_INFO_COMPRESSED
308 bool "Compressed debugging information"
309 depends on $(cc-option,-gz=zlib)
310 depends on $(ld-option,--compress-debug-sections=zlib)
312 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
313 5.0+, binutils 2.26+, and zlib.
315 Users of dpkg-deb via scripts/package/builddeb may find an increase in
316 size of their debug .deb packages with this config set, due to the
317 debug info being compressed with zlib, then the object files being
318 recompressed with a different compression scheme. But this is still
319 preferable to setting $KDEB_COMPRESS to "none" which would be even
322 config DEBUG_INFO_SPLIT
323 bool "Produce split debuginfo in .dwo files"
324 depends on $(cc-option,-gsplit-dwarf)
326 Generate debug info into separate .dwo files. This significantly
327 reduces the build directory size for builds with DEBUG_INFO,
328 because it stores the information only once on disk in .dwo
329 files instead of multiple times in object files and executables.
330 In addition the debug information is also compressed.
332 Requires recent gcc (4.7+) and recent gdb/binutils.
333 Any tool that packages or reads debug information would need
334 to know about the .dwo files and include them.
335 Incompatible with older versions of ccache.
337 config DEBUG_INFO_BTF
338 bool "Generate BTF typeinfo"
339 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
340 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
341 depends on BPF_SYSCALL
342 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
344 Generate deduplicated BTF type information from DWARF debug info.
345 Turning this on expects presence of pahole tool, which will convert
346 DWARF type info into equivalent deduplicated BTF type info.
348 config PAHOLE_HAS_SPLIT_BTF
349 def_bool PAHOLE_VERSION >= 119
351 config PAHOLE_HAS_BTF_TAG
352 def_bool PAHOLE_VERSION >= 123
353 depends on CC_IS_CLANG
355 Decide whether pahole emits btf_tag attributes (btf_type_tag and
356 btf_decl_tag) or not. Currently only clang compiler implements
357 these attributes, so make the config depend on CC_IS_CLANG.
359 config DEBUG_INFO_BTF_MODULES
361 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
363 Generate compact split BTF type information for kernel modules.
365 config MODULE_ALLOW_BTF_MISMATCH
366 bool "Allow loading modules with non-matching BTF type info"
367 depends on DEBUG_INFO_BTF_MODULES
369 For modules whose split BTF does not match vmlinux, load without
370 BTF rather than refusing to load. The default behavior with
371 module BTF enabled is to reject modules with such mismatches;
372 this option will still load module BTF where possible but ignore
373 it when a mismatch is found.
376 bool "Provide GDB scripts for kernel debugging"
378 This creates the required links to GDB helper scripts in the
379 build directory. If you load vmlinux into gdb, the helper
380 scripts will be automatically imported by gdb as well, and
381 additional functions are available to analyze a Linux kernel
382 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
388 int "Warn for stack frames larger than"
390 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
391 default 2048 if PARISC
392 default 1536 if (!64BIT && XTENSA)
393 default 1024 if !64BIT
394 default 2048 if 64BIT
396 Tell gcc to warn at build time for stack frames larger than this.
397 Setting this too low will cause a lot of warnings.
398 Setting it to 0 disables the warning.
400 config STRIP_ASM_SYMS
401 bool "Strip assembler-generated symbols during link"
404 Strip internal assembler-generated symbols during a link (symbols
405 that look like '.Lxxx') so they don't pollute the output of
406 get_wchan() and suchlike.
409 bool "Generate readable assembler code"
410 depends on DEBUG_KERNEL
413 Disable some compiler optimizations that tend to generate human unreadable
414 assembler output. This may make the kernel slightly slower, but it helps
415 to keep kernel developers who have to stare a lot at assembler listings
418 config HEADERS_INSTALL
419 bool "Install uapi headers to usr/include"
422 This option will install uapi headers (headers exported to user-space)
423 into the usr/include directory for use during the kernel build.
424 This is unneeded for building the kernel itself, but needed for some
425 user-space program samples. It is also needed by some features such
426 as uapi header sanity checks.
428 config DEBUG_SECTION_MISMATCH
429 bool "Enable full Section mismatch analysis"
432 The section mismatch analysis checks if there are illegal
433 references from one section to another section.
434 During linktime or runtime, some sections are dropped;
435 any use of code/data previously in these sections would
436 most likely result in an oops.
437 In the code, functions and variables are annotated with
438 __init,, etc. (see the full list in include/linux/init.h),
439 which results in the code/data being placed in specific sections.
440 The section mismatch analysis is always performed after a full
441 kernel build, and enabling this option causes the following
442 additional step to occur:
443 - Add the option -fno-inline-functions-called-once to gcc commands.
444 When inlining a function annotated with __init in a non-init
445 function, we would lose the section information and thus
446 the analysis would not catch the illegal reference.
447 This option tells gcc to inline less (but it does result in
450 config SECTION_MISMATCH_WARN_ONLY
451 bool "Make section mismatch errors non-fatal"
454 If you say N here, the build process will fail if there are any
455 section mismatch, instead of just throwing warnings.
459 config DEBUG_FORCE_FUNCTION_ALIGN_64B
460 bool "Force all function address 64B aligned"
461 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
463 There are cases that a commit from one domain changes the function
464 address alignment of other domains, and cause magic performance
465 bump (regression or improvement). Enable this option will help to
466 verify if the bump is caused by function alignment changes, while
467 it will slightly increase the kernel size and affect icache usage.
469 It is mainly for debug and performance tuning use.
472 # Select this config option from the architecture Kconfig, if it
473 # is preferred to always offer frame pointers as a config
474 # option on the architecture (regardless of KERNEL_DEBUG):
476 config ARCH_WANT_FRAME_POINTERS
480 bool "Compile the kernel with frame pointers"
481 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
482 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
484 If you say Y here the resulting kernel image will be slightly
485 larger and slower, but it gives very useful debugging information
486 in case of kernel bugs. (precise oopses/stacktraces/warnings)
491 config STACK_VALIDATION
492 bool "Compile-time stack metadata validation"
493 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
497 Validate frame pointer rules at compile-time. This helps ensure that
498 runtime stack traces are more reliable.
500 For more information, see
501 tools/objtool/Documentation/stack-validation.txt.
503 config NOINSTR_VALIDATION
505 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
510 bool "Generate vmlinux.map file when linking"
513 Selecting this option will pass "-Map=vmlinux.map" to ld
514 when linking vmlinux. That file can be useful for verifying
515 and debugging magic section games, and for seeing which
516 pieces of code get eliminated with
517 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
519 config DEBUG_FORCE_WEAK_PER_CPU
520 bool "Force weak per-cpu definitions"
521 depends on DEBUG_KERNEL
523 s390 and alpha require percpu variables in modules to be
524 defined weak to work around addressing range issue which
525 puts the following two restrictions on percpu variable
528 1. percpu symbols must be unique whether static or not
529 2. percpu variables can't be defined inside a function
531 To ensure that generic code follows the above rules, this
532 option forces all percpu variables to be defined as weak.
534 endmenu # "Compiler options"
536 menu "Generic Kernel Debugging Instruments"
539 bool "Magic SysRq key"
542 If you say Y here, you will have some control over the system even
543 if the system crashes for example during kernel debugging (e.g., you
544 will be able to flush the buffer cache to disk, reboot the system
545 immediately or dump some status information). This is accomplished
546 by pressing various keys while holding SysRq (Alt+PrintScreen). It
547 also works on a serial console (on PC hardware at least), if you
548 send a BREAK and then within 5 seconds a command keypress. The
549 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
550 Don't say Y unless you really know what this hack does.
552 config MAGIC_SYSRQ_DEFAULT_ENABLE
553 hex "Enable magic SysRq key functions by default"
554 depends on MAGIC_SYSRQ
557 Specifies which SysRq key functions are enabled by default.
558 This may be set to 1 or 0 to enable or disable them all, or
559 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
561 config MAGIC_SYSRQ_SERIAL
562 bool "Enable magic SysRq key over serial"
563 depends on MAGIC_SYSRQ
566 Many embedded boards have a disconnected TTL level serial which can
567 generate some garbage that can lead to spurious false sysrq detects.
568 This option allows you to decide whether you want to enable the
571 config MAGIC_SYSRQ_SERIAL_SEQUENCE
572 string "Char sequence that enables magic SysRq over serial"
573 depends on MAGIC_SYSRQ_SERIAL
576 Specifies a sequence of characters that can follow BREAK to enable
577 SysRq on a serial console.
579 If unsure, leave an empty string and the option will not be enabled.
582 bool "Debug Filesystem"
584 debugfs is a virtual file system that kernel developers use to put
585 debugging files into. Enable this option to be able to read and
586 write to these files.
588 For detailed documentation on the debugfs API, see
589 Documentation/filesystems/.
594 prompt "Debugfs default access"
596 default DEBUG_FS_ALLOW_ALL
598 This selects the default access restrictions for debugfs.
599 It can be overridden with kernel command line option
600 debugfs=[on,no-mount,off]. The restrictions apply for API access
601 and filesystem registration.
603 config DEBUG_FS_ALLOW_ALL
606 No restrictions apply. Both API and filesystem registration
607 is on. This is the normal default operation.
609 config DEBUG_FS_DISALLOW_MOUNT
610 bool "Do not register debugfs as filesystem"
612 The API is open but filesystem is not loaded. Clients can still do
613 their work and read with debug tools that do not need
616 config DEBUG_FS_ALLOW_NONE
619 Access is off. Clients get -PERM when trying to create nodes in
620 debugfs tree and debugfs is not registered as a filesystem.
621 Client can then back-off or continue without debugfs access.
625 source "lib/Kconfig.kgdb"
626 source "lib/Kconfig.ubsan"
627 source "lib/Kconfig.kcsan"
631 menu "Networking Debugging"
633 source "net/Kconfig.debug"
635 endmenu # "Networking Debugging"
637 menu "Memory Debugging"
639 source "mm/Kconfig.debug"
642 bool "Debug object operations"
643 depends on DEBUG_KERNEL
645 If you say Y here, additional code will be inserted into the
646 kernel to track the life time of various objects and validate
647 the operations on those objects.
649 config DEBUG_OBJECTS_SELFTEST
650 bool "Debug objects selftest"
651 depends on DEBUG_OBJECTS
653 This enables the selftest of the object debug code.
655 config DEBUG_OBJECTS_FREE
656 bool "Debug objects in freed memory"
657 depends on DEBUG_OBJECTS
659 This enables checks whether a k/v free operation frees an area
660 which contains an object which has not been deactivated
661 properly. This can make kmalloc/kfree-intensive workloads
664 config DEBUG_OBJECTS_TIMERS
665 bool "Debug timer objects"
666 depends on DEBUG_OBJECTS
668 If you say Y here, additional code will be inserted into the
669 timer routines to track the life time of timer objects and
670 validate the timer operations.
672 config DEBUG_OBJECTS_WORK
673 bool "Debug work objects"
674 depends on DEBUG_OBJECTS
676 If you say Y here, additional code will be inserted into the
677 work queue routines to track the life time of work objects and
678 validate the work operations.
680 config DEBUG_OBJECTS_RCU_HEAD
681 bool "Debug RCU callbacks objects"
682 depends on DEBUG_OBJECTS
684 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
686 config DEBUG_OBJECTS_PERCPU_COUNTER
687 bool "Debug percpu counter objects"
688 depends on DEBUG_OBJECTS
690 If you say Y here, additional code will be inserted into the
691 percpu counter routines to track the life time of percpu counter
692 objects and validate the percpu counter operations.
694 config DEBUG_OBJECTS_ENABLE_DEFAULT
695 int "debug_objects bootup default value (0-1)"
698 depends on DEBUG_OBJECTS
700 Debug objects boot parameter default value
702 config HAVE_DEBUG_KMEMLEAK
705 config DEBUG_KMEMLEAK
706 bool "Kernel memory leak detector"
707 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
709 select STACKTRACE if STACKTRACE_SUPPORT
713 Say Y here if you want to enable the memory leak
714 detector. The memory allocation/freeing is traced in a way
715 similar to the Boehm's conservative garbage collector, the
716 difference being that the orphan objects are not freed but
717 only shown in /sys/kernel/debug/kmemleak. Enabling this
718 feature will introduce an overhead to memory
719 allocations. See Documentation/dev-tools/kmemleak.rst for more
722 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
723 of finding leaks due to the slab objects poisoning.
725 In order to access the kmemleak file, debugfs needs to be
726 mounted (usually at /sys/kernel/debug).
728 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
729 int "Kmemleak memory pool size"
730 depends on DEBUG_KMEMLEAK
734 Kmemleak must track all the memory allocations to avoid
735 reporting false positives. Since memory may be allocated or
736 freed before kmemleak is fully initialised, use a static pool
737 of metadata objects to track such callbacks. After kmemleak is
738 fully initialised, this memory pool acts as an emergency one
739 if slab allocations fail.
741 config DEBUG_KMEMLEAK_TEST
742 tristate "Simple test for the kernel memory leak detector"
743 depends on DEBUG_KMEMLEAK && m
745 This option enables a module that explicitly leaks memory.
749 config DEBUG_KMEMLEAK_DEFAULT_OFF
750 bool "Default kmemleak to off"
751 depends on DEBUG_KMEMLEAK
753 Say Y here to disable kmemleak by default. It can then be enabled
754 on the command line via kmemleak=on.
756 config DEBUG_KMEMLEAK_AUTO_SCAN
757 bool "Enable kmemleak auto scan thread on boot up"
759 depends on DEBUG_KMEMLEAK
761 Depending on the cpu, kmemleak scan may be cpu intensive and can
762 stall user tasks at times. This option enables/disables automatic
763 kmemleak scan at boot up.
765 Say N here to disable kmemleak auto scan thread to stop automatic
766 scanning. Disabling this option disables automatic reporting of
771 config DEBUG_STACK_USAGE
772 bool "Stack utilization instrumentation"
773 depends on DEBUG_KERNEL && !IA64
775 Enables the display of the minimum amount of free stack which each
776 task has ever had available in the sysrq-T and sysrq-P debug output.
778 This option will slow down process creation somewhat.
780 config SCHED_STACK_END_CHECK
781 bool "Detect stack corruption on calls to schedule()"
782 depends on DEBUG_KERNEL
785 This option checks for a stack overrun on calls to schedule().
786 If the stack end location is found to be over written always panic as
787 the content of the corrupted region can no longer be trusted.
788 This is to ensure no erroneous behaviour occurs which could result in
789 data corruption or a sporadic crash at a later stage once the region
790 is examined. The runtime overhead introduced is minimal.
792 config ARCH_HAS_DEBUG_VM_PGTABLE
795 An architecture should select this when it can successfully
796 build and run DEBUG_VM_PGTABLE.
800 depends on DEBUG_KERNEL
802 Enable this to turn on extended checks in the virtual-memory system
803 that may impact performance.
807 config DEBUG_VM_VMACACHE
808 bool "Debug VMA caching"
811 Enable this to turn on VMA caching debug information. Doing so
812 can cause significant overhead, so only enable it in non-production
818 bool "Debug VM red-black trees"
821 Enable VM red-black tree debugging information and extra validations.
825 config DEBUG_VM_PGFLAGS
826 bool "Debug page-flags operations"
829 Enables extra validation on page flags operations.
833 config DEBUG_VM_PGTABLE
834 bool "Debug arch page table for semantics compliance"
836 depends on ARCH_HAS_DEBUG_VM_PGTABLE
837 default y if DEBUG_VM
839 This option provides a debug method which can be used to test
840 architecture page table helper functions on various platforms in
841 verifying if they comply with expected generic MM semantics. This
842 will help architecture code in making sure that any changes or
843 new additions of these helpers still conform to expected
844 semantics of the generic MM. Platforms will have to opt in for
845 this through ARCH_HAS_DEBUG_VM_PGTABLE.
849 config ARCH_HAS_DEBUG_VIRTUAL
853 bool "Debug VM translations"
854 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
856 Enable some costly sanity checks in virtual to page code. This can
857 catch mistakes with virt_to_page() and friends.
861 config DEBUG_NOMMU_REGIONS
862 bool "Debug the global anon/private NOMMU mapping region tree"
863 depends on DEBUG_KERNEL && !MMU
865 This option causes the global tree of anonymous and private mapping
866 regions to be regularly checked for invalid topology.
868 config DEBUG_MEMORY_INIT
869 bool "Debug memory initialisation" if EXPERT
872 Enable this for additional checks during memory initialisation.
873 The sanity checks verify aspects of the VM such as the memory model
874 and other information provided by the architecture. Verbose
875 information will be printed at KERN_DEBUG loglevel depending
876 on the mminit_loglevel= command-line option.
880 config MEMORY_NOTIFIER_ERROR_INJECT
881 tristate "Memory hotplug notifier error injection module"
882 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
884 This option provides the ability to inject artificial errors to
885 memory hotplug notifier chain callbacks. It is controlled through
886 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
888 If the notifier call chain should be failed with some events
889 notified, write the error code to "actions/<notifier event>/error".
891 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
893 # cd /sys/kernel/debug/notifier-error-inject/memory
894 # echo -12 > actions/MEM_GOING_OFFLINE/error
895 # echo offline > /sys/devices/system/memory/memoryXXX/state
896 bash: echo: write error: Cannot allocate memory
898 To compile this code as a module, choose M here: the module will
899 be called memory-notifier-error-inject.
903 config DEBUG_PER_CPU_MAPS
904 bool "Debug access to per_cpu maps"
905 depends on DEBUG_KERNEL
908 Say Y to verify that the per_cpu map being accessed has
909 been set up. This adds a fair amount of code to kernel memory
910 and decreases performance.
914 config DEBUG_KMAP_LOCAL
915 bool "Debug kmap_local temporary mappings"
916 depends on DEBUG_KERNEL && KMAP_LOCAL
918 This option enables additional error checking for the kmap_local
919 infrastructure. Disable for production use.
921 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
924 config DEBUG_KMAP_LOCAL_FORCE_MAP
925 bool "Enforce kmap_local temporary mappings"
926 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
928 select DEBUG_KMAP_LOCAL
930 This option enforces temporary mappings through the kmap_local
931 mechanism for non-highmem pages and on non-highmem systems.
932 Disable this for production systems!
935 bool "Highmem debugging"
936 depends on DEBUG_KERNEL && HIGHMEM
937 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
938 select DEBUG_KMAP_LOCAL
940 This option enables additional error checking for high memory
941 systems. Disable for production systems.
943 config HAVE_DEBUG_STACKOVERFLOW
946 config DEBUG_STACKOVERFLOW
947 bool "Check for stack overflows"
948 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
950 Say Y here if you want to check for overflows of kernel, IRQ
951 and exception stacks (if your architecture uses them). This
952 option will show detailed messages if free stack space drops
953 below a certain limit.
955 These kinds of bugs usually occur when call-chains in the
956 kernel get too deep, especially when interrupts are
959 Use this in cases where you see apparently random memory
960 corruption, especially if it appears in 'struct thread_info'
962 If in doubt, say "N".
964 source "lib/Kconfig.kasan"
965 source "lib/Kconfig.kfence"
967 endmenu # "Memory Debugging"
970 bool "Debug shared IRQ handlers"
971 depends on DEBUG_KERNEL
973 Enable this to generate a spurious interrupt just before a shared
974 interrupt handler is deregistered (generating one when registering
975 is currently disabled). Drivers need to handle this correctly. Some
976 don't and need to be caught.
978 menu "Debug Oops, Lockups and Hangs"
983 Say Y here to enable the kernel to panic when it oopses. This
984 has the same effect as setting oops=panic on the kernel command
987 This feature is useful to ensure that the kernel does not do
988 anything erroneous after an oops which could result in data
989 corruption or other issues.
993 config PANIC_ON_OOPS_VALUE
996 default 0 if !PANIC_ON_OOPS
997 default 1 if PANIC_ON_OOPS
1003 Set the timeout value (in seconds) until a reboot occurs when
1004 the kernel panics. If n = 0, then we wait forever. A timeout
1005 value n > 0 will wait n seconds before rebooting, while a timeout
1006 value n < 0 will reboot immediately.
1008 config LOCKUP_DETECTOR
1011 config SOFTLOCKUP_DETECTOR
1012 bool "Detect Soft Lockups"
1013 depends on DEBUG_KERNEL && !S390
1014 select LOCKUP_DETECTOR
1016 Say Y here to enable the kernel to act as a watchdog to detect
1019 Softlockups are bugs that cause the kernel to loop in kernel
1020 mode for more than 20 seconds, without giving other tasks a
1021 chance to run. The current stack trace is displayed upon
1022 detection and the system will stay locked up.
1024 config BOOTPARAM_SOFTLOCKUP_PANIC
1025 bool "Panic (Reboot) On Soft Lockups"
1026 depends on SOFTLOCKUP_DETECTOR
1028 Say Y here to enable the kernel to panic on "soft lockups",
1029 which are bugs that cause the kernel to loop in kernel
1030 mode for more than 20 seconds (configurable using the watchdog_thresh
1031 sysctl), without giving other tasks a chance to run.
1033 The panic can be used in combination with panic_timeout,
1034 to cause the system to reboot automatically after a
1035 lockup has been detected. This feature is useful for
1036 high-availability systems that have uptime guarantees and
1037 where a lockup must be resolved ASAP.
1041 config HARDLOCKUP_DETECTOR_PERF
1043 select SOFTLOCKUP_DETECTOR
1046 # Enables a timestamp based low pass filter to compensate for perf based
1047 # hard lockup detection which runs too fast due to turbo modes.
1049 config HARDLOCKUP_CHECK_TIMESTAMP
1053 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1054 # lockup detector rather than the perf based detector.
1056 config HARDLOCKUP_DETECTOR
1057 bool "Detect Hard Lockups"
1058 depends on DEBUG_KERNEL && !S390
1059 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1060 select LOCKUP_DETECTOR
1061 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1063 Say Y here to enable the kernel to act as a watchdog to detect
1066 Hardlockups are bugs that cause the CPU to loop in kernel mode
1067 for more than 10 seconds, without letting other interrupts have a
1068 chance to run. The current stack trace is displayed upon detection
1069 and the system will stay locked up.
1071 config BOOTPARAM_HARDLOCKUP_PANIC
1072 bool "Panic (Reboot) On Hard Lockups"
1073 depends on HARDLOCKUP_DETECTOR
1075 Say Y here to enable the kernel to panic on "hard lockups",
1076 which are bugs that cause the kernel to loop in kernel
1077 mode with interrupts disabled for more than 10 seconds (configurable
1078 using the watchdog_thresh sysctl).
1082 config DETECT_HUNG_TASK
1083 bool "Detect Hung Tasks"
1084 depends on DEBUG_KERNEL
1085 default SOFTLOCKUP_DETECTOR
1087 Say Y here to enable the kernel to detect "hung tasks",
1088 which are bugs that cause the task to be stuck in
1089 uninterruptible "D" state indefinitely.
1091 When a hung task is detected, the kernel will print the
1092 current stack trace (which you should report), but the
1093 task will stay in uninterruptible state. If lockdep is
1094 enabled then all held locks will also be reported. This
1095 feature has negligible overhead.
1097 config DEFAULT_HUNG_TASK_TIMEOUT
1098 int "Default timeout for hung task detection (in seconds)"
1099 depends on DETECT_HUNG_TASK
1102 This option controls the default timeout (in seconds) used
1103 to determine when a task has become non-responsive and should
1106 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1107 sysctl or by writing a value to
1108 /proc/sys/kernel/hung_task_timeout_secs.
1110 A timeout of 0 disables the check. The default is two minutes.
1111 Keeping the default should be fine in most cases.
1113 config BOOTPARAM_HUNG_TASK_PANIC
1114 bool "Panic (Reboot) On Hung Tasks"
1115 depends on DETECT_HUNG_TASK
1117 Say Y here to enable the kernel to panic on "hung tasks",
1118 which are bugs that cause the kernel to leave a task stuck
1119 in uninterruptible "D" state.
1121 The panic can be used in combination with panic_timeout,
1122 to cause the system to reboot automatically after a
1123 hung task has been detected. This feature is useful for
1124 high-availability systems that have uptime guarantees and
1125 where a hung tasks must be resolved ASAP.
1130 bool "Detect Workqueue Stalls"
1131 depends on DEBUG_KERNEL
1133 Say Y here to enable stall detection on workqueues. If a
1134 worker pool doesn't make forward progress on a pending work
1135 item for over a given amount of time, 30s by default, a
1136 warning message is printed along with dump of workqueue
1137 state. This can be configured through kernel parameter
1138 "workqueue.watchdog_thresh" and its sysfs counterpart.
1141 tristate "Test module to generate lockups"
1144 This builds the "test_lockup" module that helps to make sure
1145 that watchdogs and lockup detectors are working properly.
1147 Depending on module parameters it could emulate soft or hard
1148 lockup, "hung task", or locking arbitrary lock for a long time.
1149 Also it could generate series of lockups with cooling-down periods.
1153 endmenu # "Debug lockups and hangs"
1155 menu "Scheduler Debugging"
1158 bool "Collect scheduler debugging info"
1159 depends on DEBUG_KERNEL && PROC_FS
1162 If you say Y here, the /proc/sched_debug file will be provided
1163 that can help debug the scheduler. The runtime overhead of this
1171 bool "Collect scheduler statistics"
1172 depends on DEBUG_KERNEL && PROC_FS
1175 If you say Y here, additional code will be inserted into the
1176 scheduler and related routines to collect statistics about
1177 scheduler behavior and provide them in /proc/schedstat. These
1178 stats may be useful for both tuning and debugging the scheduler
1179 If you aren't debugging the scheduler or trying to tune a specific
1180 application, you can say N to avoid the very slight overhead
1185 config DEBUG_TIMEKEEPING
1186 bool "Enable extra timekeeping sanity checking"
1188 This option will enable additional timekeeping sanity checks
1189 which may be helpful when diagnosing issues where timekeeping
1190 problems are suspected.
1192 This may include checks in the timekeeping hotpaths, so this
1193 option may have a (very small) performance impact to some
1198 config DEBUG_PREEMPT
1199 bool "Debug preemptible kernel"
1200 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1203 If you say Y here then the kernel will use a debug variant of the
1204 commonly used smp_processor_id() function and will print warnings
1205 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1206 will detect preemption count underflows.
1208 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1210 config LOCK_DEBUGGING_SUPPORT
1212 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1215 config PROVE_LOCKING
1216 bool "Lock debugging: prove locking correctness"
1217 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1219 select DEBUG_SPINLOCK
1220 select DEBUG_MUTEXES if !PREEMPT_RT
1221 select DEBUG_RT_MUTEXES if RT_MUTEXES
1223 select DEBUG_WW_MUTEX_SLOWPATH
1224 select DEBUG_LOCK_ALLOC
1225 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1226 select TRACE_IRQFLAGS
1229 This feature enables the kernel to prove that all locking
1230 that occurs in the kernel runtime is mathematically
1231 correct: that under no circumstance could an arbitrary (and
1232 not yet triggered) combination of observed locking
1233 sequences (on an arbitrary number of CPUs, running an
1234 arbitrary number of tasks and interrupt contexts) cause a
1237 In short, this feature enables the kernel to report locking
1238 related deadlocks before they actually occur.
1240 The proof does not depend on how hard and complex a
1241 deadlock scenario would be to trigger: how many
1242 participant CPUs, tasks and irq-contexts would be needed
1243 for it to trigger. The proof also does not depend on
1244 timing: if a race and a resulting deadlock is possible
1245 theoretically (no matter how unlikely the race scenario
1246 is), it will be proven so and will immediately be
1247 reported by the kernel (once the event is observed that
1248 makes the deadlock theoretically possible).
1250 If a deadlock is impossible (i.e. the locking rules, as
1251 observed by the kernel, are mathematically correct), the
1252 kernel reports nothing.
1254 NOTE: this feature can also be enabled for rwlocks, mutexes
1255 and rwsems - in which case all dependencies between these
1256 different locking variants are observed and mapped too, and
1257 the proof of observed correctness is also maintained for an
1258 arbitrary combination of these separate locking variants.
1260 For more details, see Documentation/locking/lockdep-design.rst.
1262 config PROVE_RAW_LOCK_NESTING
1263 bool "Enable raw_spinlock - spinlock nesting checks"
1264 depends on PROVE_LOCKING
1267 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1268 that the lock nesting rules for PREEMPT_RT enabled kernels are
1271 NOTE: There are known nesting problems. So if you enable this
1272 option expect lockdep splats until these problems have been fully
1273 addressed which is work in progress. This config switch allows to
1274 identify and analyze these problems. It will be removed and the
1275 check permanently enabled once the main issues have been fixed.
1277 If unsure, select N.
1280 bool "Lock usage statistics"
1281 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1283 select DEBUG_SPINLOCK
1284 select DEBUG_MUTEXES if !PREEMPT_RT
1285 select DEBUG_RT_MUTEXES if RT_MUTEXES
1286 select DEBUG_LOCK_ALLOC
1289 This feature enables tracking lock contention points
1291 For more details, see Documentation/locking/lockstat.rst
1293 This also enables lock events required by "perf lock",
1295 If you want to use "perf lock", you also need to turn on
1296 CONFIG_EVENT_TRACING.
1298 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1299 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1301 config DEBUG_RT_MUTEXES
1302 bool "RT Mutex debugging, deadlock detection"
1303 depends on DEBUG_KERNEL && RT_MUTEXES
1305 This allows rt mutex semantics violations and rt mutex related
1306 deadlocks (lockups) to be detected and reported automatically.
1308 config DEBUG_SPINLOCK
1309 bool "Spinlock and rw-lock debugging: basic checks"
1310 depends on DEBUG_KERNEL
1311 select UNINLINE_SPIN_UNLOCK
1313 Say Y here and build SMP to catch missing spinlock initialization
1314 and certain other kinds of spinlock errors commonly made. This is
1315 best used in conjunction with the NMI watchdog so that spinlock
1316 deadlocks are also debuggable.
1318 config DEBUG_MUTEXES
1319 bool "Mutex debugging: basic checks"
1320 depends on DEBUG_KERNEL && !PREEMPT_RT
1322 This feature allows mutex semantics violations to be detected and
1325 config DEBUG_WW_MUTEX_SLOWPATH
1326 bool "Wait/wound mutex debugging: Slowpath testing"
1327 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1328 select DEBUG_LOCK_ALLOC
1329 select DEBUG_SPINLOCK
1330 select DEBUG_MUTEXES if !PREEMPT_RT
1331 select DEBUG_RT_MUTEXES if PREEMPT_RT
1333 This feature enables slowpath testing for w/w mutex users by
1334 injecting additional -EDEADLK wound/backoff cases. Together with
1335 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1336 will test all possible w/w mutex interface abuse with the
1337 exception of simply not acquiring all the required locks.
1338 Note that this feature can introduce significant overhead, so
1339 it really should not be enabled in a production or distro kernel,
1340 even a debug kernel. If you are a driver writer, enable it. If
1341 you are a distro, do not.
1344 bool "RW Semaphore debugging: basic checks"
1345 depends on DEBUG_KERNEL
1347 This debugging feature allows mismatched rw semaphore locks
1348 and unlocks to be detected and reported.
1350 config DEBUG_LOCK_ALLOC
1351 bool "Lock debugging: detect incorrect freeing of live locks"
1352 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1353 select DEBUG_SPINLOCK
1354 select DEBUG_MUTEXES if !PREEMPT_RT
1355 select DEBUG_RT_MUTEXES if RT_MUTEXES
1358 This feature will check whether any held lock (spinlock, rwlock,
1359 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1360 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1361 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1362 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1363 held during task exit.
1367 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1372 config LOCKDEP_SMALL
1376 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1377 depends on LOCKDEP && !LOCKDEP_SMALL
1381 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1383 config LOCKDEP_CHAINS_BITS
1384 int "Bitsize for MAX_LOCKDEP_CHAINS"
1385 depends on LOCKDEP && !LOCKDEP_SMALL
1389 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1391 config LOCKDEP_STACK_TRACE_BITS
1392 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1393 depends on LOCKDEP && !LOCKDEP_SMALL
1397 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1399 config LOCKDEP_STACK_TRACE_HASH_BITS
1400 int "Bitsize for STACK_TRACE_HASH_SIZE"
1401 depends on LOCKDEP && !LOCKDEP_SMALL
1405 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1407 config LOCKDEP_CIRCULAR_QUEUE_BITS
1408 int "Bitsize for elements in circular_queue struct"
1413 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1415 config DEBUG_LOCKDEP
1416 bool "Lock dependency engine debugging"
1417 depends on DEBUG_KERNEL && LOCKDEP
1418 select DEBUG_IRQFLAGS
1420 If you say Y here, the lock dependency engine will do
1421 additional runtime checks to debug itself, at the price
1422 of more runtime overhead.
1424 config DEBUG_ATOMIC_SLEEP
1425 bool "Sleep inside atomic section checking"
1426 select PREEMPT_COUNT
1427 depends on DEBUG_KERNEL
1428 depends on !ARCH_NO_PREEMPT
1430 If you say Y here, various routines which may sleep will become very
1431 noisy if they are called inside atomic sections: when a spinlock is
1432 held, inside an rcu read side critical section, inside preempt disabled
1433 sections, inside an interrupt, etc...
1435 config DEBUG_LOCKING_API_SELFTESTS
1436 bool "Locking API boot-time self-tests"
1437 depends on DEBUG_KERNEL
1439 Say Y here if you want the kernel to run a short self-test during
1440 bootup. The self-test checks whether common types of locking bugs
1441 are detected by debugging mechanisms or not. (if you disable
1442 lock debugging then those bugs won't be detected of course.)
1443 The following locking APIs are covered: spinlocks, rwlocks,
1446 config LOCK_TORTURE_TEST
1447 tristate "torture tests for locking"
1448 depends on DEBUG_KERNEL
1451 This option provides a kernel module that runs torture tests
1452 on kernel locking primitives. The kernel module may be built
1453 after the fact on the running kernel to be tested, if desired.
1455 Say Y here if you want kernel locking-primitive torture tests
1456 to be built into the kernel.
1457 Say M if you want these torture tests to build as a module.
1458 Say N if you are unsure.
1460 config WW_MUTEX_SELFTEST
1461 tristate "Wait/wound mutex selftests"
1463 This option provides a kernel module that runs tests on the
1464 on the struct ww_mutex locking API.
1466 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1467 with this test harness.
1469 Say M if you want these self tests to build as a module.
1470 Say N if you are unsure.
1472 config SCF_TORTURE_TEST
1473 tristate "torture tests for smp_call_function*()"
1474 depends on DEBUG_KERNEL
1477 This option provides a kernel module that runs torture tests
1478 on the smp_call_function() family of primitives. The kernel
1479 module may be built after the fact on the running kernel to
1480 be tested, if desired.
1482 config CSD_LOCK_WAIT_DEBUG
1483 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1484 depends on DEBUG_KERNEL
1488 This option enables debug prints when CPUs are slow to respond
1489 to the smp_call_function*() IPI wrappers. These debug prints
1490 include the IPI handler function currently executing (if any)
1491 and relevant stack traces.
1493 endmenu # lock debugging
1495 config TRACE_IRQFLAGS
1496 depends on TRACE_IRQFLAGS_SUPPORT
1499 Enables hooks to interrupt enabling and disabling for
1500 either tracing or lock debugging.
1502 config TRACE_IRQFLAGS_NMI
1504 depends on TRACE_IRQFLAGS
1505 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1507 config DEBUG_IRQFLAGS
1508 bool "Debug IRQ flag manipulation"
1510 Enables checks for potentially unsafe enabling or disabling of
1511 interrupts, such as calling raw_local_irq_restore() when interrupts
1515 bool "Stack backtrace support"
1516 depends on STACKTRACE_SUPPORT
1518 This option causes the kernel to create a /proc/pid/stack for
1519 every process, showing its current stack trace.
1520 It is also used by various kernel debugging features that require
1521 stack trace generation.
1523 config WARN_ALL_UNSEEDED_RANDOM
1524 bool "Warn for all uses of unseeded randomness"
1527 Some parts of the kernel contain bugs relating to their use of
1528 cryptographically secure random numbers before it's actually possible
1529 to generate those numbers securely. This setting ensures that these
1530 flaws don't go unnoticed, by enabling a message, should this ever
1531 occur. This will allow people with obscure setups to know when things
1532 are going wrong, so that they might contact developers about fixing
1535 Unfortunately, on some models of some architectures getting
1536 a fully seeded CRNG is extremely difficult, and so this can
1537 result in dmesg getting spammed for a surprisingly long
1538 time. This is really bad from a security perspective, and
1539 so architecture maintainers really need to do what they can
1540 to get the CRNG seeded sooner after the system is booted.
1541 However, since users cannot do anything actionable to
1542 address this, by default this option is disabled.
1544 Say Y here if you want to receive warnings for all uses of
1545 unseeded randomness. This will be of use primarily for
1546 those developers interested in improving the security of
1547 Linux kernels running on their architecture (or
1550 config DEBUG_KOBJECT
1551 bool "kobject debugging"
1552 depends on DEBUG_KERNEL
1554 If you say Y here, some extra kobject debugging messages will be sent
1557 config DEBUG_KOBJECT_RELEASE
1558 bool "kobject release debugging"
1559 depends on DEBUG_OBJECTS_TIMERS
1561 kobjects are reference counted objects. This means that their
1562 last reference count put is not predictable, and the kobject can
1563 live on past the point at which a driver decides to drop it's
1564 initial reference to the kobject gained on allocation. An
1565 example of this would be a struct device which has just been
1568 However, some buggy drivers assume that after such an operation,
1569 the memory backing the kobject can be immediately freed. This
1570 goes completely against the principles of a refcounted object.
1572 If you say Y here, the kernel will delay the release of kobjects
1573 on the last reference count to improve the visibility of this
1574 kind of kobject release bug.
1576 config HAVE_DEBUG_BUGVERBOSE
1579 menu "Debug kernel data structures"
1582 bool "Debug linked list manipulation"
1583 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1585 Enable this to turn on extended checks in the linked-list
1591 bool "Debug priority linked list manipulation"
1592 depends on DEBUG_KERNEL
1594 Enable this to turn on extended checks in the priority-ordered
1595 linked-list (plist) walking routines. This checks the entire
1596 list multiple times during each manipulation.
1601 bool "Debug SG table operations"
1602 depends on DEBUG_KERNEL
1604 Enable this to turn on checks on scatter-gather tables. This can
1605 help find problems with drivers that do not properly initialize
1610 config DEBUG_NOTIFIERS
1611 bool "Debug notifier call chains"
1612 depends on DEBUG_KERNEL
1614 Enable this to turn on sanity checking for notifier call chains.
1615 This is most useful for kernel developers to make sure that
1616 modules properly unregister themselves from notifier chains.
1617 This is a relatively cheap check but if you care about maximum
1620 config BUG_ON_DATA_CORRUPTION
1621 bool "Trigger a BUG when data corruption is detected"
1624 Select this option if the kernel should BUG when it encounters
1625 data corruption in kernel memory structures when they get checked
1632 config DEBUG_CREDENTIALS
1633 bool "Debug credential management"
1634 depends on DEBUG_KERNEL
1636 Enable this to turn on some debug checking for credential
1637 management. The additional code keeps track of the number of
1638 pointers from task_structs to any given cred struct, and checks to
1639 see that this number never exceeds the usage count of the cred
1642 Furthermore, if SELinux is enabled, this also checks that the
1643 security pointer in the cred struct is never seen to be invalid.
1647 source "kernel/rcu/Kconfig.debug"
1649 config DEBUG_WQ_FORCE_RR_CPU
1650 bool "Force round-robin CPU selection for unbound work items"
1651 depends on DEBUG_KERNEL
1654 Workqueue used to implicitly guarantee that work items queued
1655 without explicit CPU specified are put on the local CPU. This
1656 guarantee is no longer true and while local CPU is still
1657 preferred work items may be put on foreign CPUs. Kernel
1658 parameter "workqueue.debug_force_rr_cpu" is added to force
1659 round-robin CPU selection to flush out usages which depend on the
1660 now broken guarantee. This config option enables the debug
1661 feature by default. When enabled, memory and cache locality will
1664 config CPU_HOTPLUG_STATE_CONTROL
1665 bool "Enable CPU hotplug state control"
1666 depends on DEBUG_KERNEL
1667 depends on HOTPLUG_CPU
1670 Allows to write steps between "offline" and "online" to the CPUs
1671 sysfs target file so states can be stepped granular. This is a debug
1672 option for now as the hotplug machinery cannot be stopped and
1673 restarted at arbitrary points yet.
1675 Say N if your are unsure.
1678 bool "Latency measuring infrastructure"
1679 depends on DEBUG_KERNEL
1680 depends on STACKTRACE_SUPPORT
1682 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1688 Enable this option if you want to use the LatencyTOP tool
1689 to find out which userspace is blocking on what kernel operations.
1691 source "kernel/trace/Kconfig"
1693 config PROVIDE_OHCI1394_DMA_INIT
1694 bool "Remote debugging over FireWire early on boot"
1695 depends on PCI && X86
1697 If you want to debug problems which hang or crash the kernel early
1698 on boot and the crashing machine has a FireWire port, you can use
1699 this feature to remotely access the memory of the crashed machine
1700 over FireWire. This employs remote DMA as part of the OHCI1394
1701 specification which is now the standard for FireWire controllers.
1703 With remote DMA, you can monitor the printk buffer remotely using
1704 firescope and access all memory below 4GB using fireproxy from gdb.
1705 Even controlling a kernel debugger is possible using remote DMA.
1709 If ohci1394_dma=early is used as boot parameter, it will initialize
1710 all OHCI1394 controllers which are found in the PCI config space.
1712 As all changes to the FireWire bus such as enabling and disabling
1713 devices cause a bus reset and thereby disable remote DMA for all
1714 devices, be sure to have the cable plugged and FireWire enabled on
1715 the debugging host before booting the debug target for debugging.
1717 This code (~1k) is freed after boot. By then, the firewire stack
1718 in charge of the OHCI-1394 controllers should be used instead.
1720 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1722 source "samples/Kconfig"
1724 config ARCH_HAS_DEVMEM_IS_ALLOWED
1727 config STRICT_DEVMEM
1728 bool "Filter access to /dev/mem"
1729 depends on MMU && DEVMEM
1730 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1731 default y if PPC || X86 || ARM64
1733 If this option is disabled, you allow userspace (root) access to all
1734 of memory, including kernel and userspace memory. Accidental
1735 access to this is obviously disastrous, but specific access can
1736 be used by people debugging the kernel. Note that with PAT support
1737 enabled, even in this case there are restrictions on /dev/mem
1738 use due to the cache aliasing requirements.
1740 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1741 file only allows userspace access to PCI space and the BIOS code and
1742 data regions. This is sufficient for dosemu and X and all common
1747 config IO_STRICT_DEVMEM
1748 bool "Filter I/O access to /dev/mem"
1749 depends on STRICT_DEVMEM
1751 If this option is disabled, you allow userspace (root) access to all
1752 io-memory regardless of whether a driver is actively using that
1753 range. Accidental access to this is obviously disastrous, but
1754 specific access can be used by people debugging kernel drivers.
1756 If this option is switched on, the /dev/mem file only allows
1757 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1758 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1759 if the driver using a given range cannot be disabled.
1763 menu "$(SRCARCH) Debugging"
1765 source "arch/$(SRCARCH)/Kconfig.debug"
1769 menu "Kernel Testing and Coverage"
1771 source "lib/kunit/Kconfig"
1773 config NOTIFIER_ERROR_INJECTION
1774 tristate "Notifier error injection"
1775 depends on DEBUG_KERNEL
1778 This option provides the ability to inject artificial errors to
1779 specified notifier chain callbacks. It is useful to test the error
1780 handling of notifier call chain failures.
1784 config PM_NOTIFIER_ERROR_INJECT
1785 tristate "PM notifier error injection module"
1786 depends on PM && NOTIFIER_ERROR_INJECTION
1787 default m if PM_DEBUG
1789 This option provides the ability to inject artificial errors to
1790 PM notifier chain callbacks. It is controlled through debugfs
1791 interface /sys/kernel/debug/notifier-error-inject/pm
1793 If the notifier call chain should be failed with some events
1794 notified, write the error code to "actions/<notifier event>/error".
1796 Example: Inject PM suspend error (-12 = -ENOMEM)
1798 # cd /sys/kernel/debug/notifier-error-inject/pm/
1799 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1800 # echo mem > /sys/power/state
1801 bash: echo: write error: Cannot allocate memory
1803 To compile this code as a module, choose M here: the module will
1804 be called pm-notifier-error-inject.
1808 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1809 tristate "OF reconfig notifier error injection module"
1810 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1812 This option provides the ability to inject artificial errors to
1813 OF reconfig notifier chain callbacks. It is controlled
1814 through debugfs interface under
1815 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1817 If the notifier call chain should be failed with some events
1818 notified, write the error code to "actions/<notifier event>/error".
1820 To compile this code as a module, choose M here: the module will
1821 be called of-reconfig-notifier-error-inject.
1825 config NETDEV_NOTIFIER_ERROR_INJECT
1826 tristate "Netdev notifier error injection module"
1827 depends on NET && NOTIFIER_ERROR_INJECTION
1829 This option provides the ability to inject artificial errors to
1830 netdevice notifier chain callbacks. It is controlled through debugfs
1831 interface /sys/kernel/debug/notifier-error-inject/netdev
1833 If the notifier call chain should be failed with some events
1834 notified, write the error code to "actions/<notifier event>/error".
1836 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1838 # cd /sys/kernel/debug/notifier-error-inject/netdev
1839 # echo -22 > actions/NETDEV_CHANGEMTU/error
1840 # ip link set eth0 mtu 1024
1841 RTNETLINK answers: Invalid argument
1843 To compile this code as a module, choose M here: the module will
1844 be called netdev-notifier-error-inject.
1848 config FUNCTION_ERROR_INJECTION
1850 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1852 config FAULT_INJECTION
1853 bool "Fault-injection framework"
1854 depends on DEBUG_KERNEL
1856 Provide fault-injection framework.
1857 For more details, see Documentation/fault-injection/.
1860 bool "Fault-injection capability for kmalloc"
1861 depends on FAULT_INJECTION
1862 depends on SLAB || SLUB
1864 Provide fault-injection capability for kmalloc.
1866 config FAIL_PAGE_ALLOC
1867 bool "Fault-injection capability for alloc_pages()"
1868 depends on FAULT_INJECTION
1870 Provide fault-injection capability for alloc_pages().
1872 config FAULT_INJECTION_USERCOPY
1873 bool "Fault injection capability for usercopy functions"
1874 depends on FAULT_INJECTION
1876 Provides fault-injection capability to inject failures
1877 in usercopy functions (copy_from_user(), get_user(), ...).
1879 config FAIL_MAKE_REQUEST
1880 bool "Fault-injection capability for disk IO"
1881 depends on FAULT_INJECTION && BLOCK
1883 Provide fault-injection capability for disk IO.
1885 config FAIL_IO_TIMEOUT
1886 bool "Fault-injection capability for faking disk interrupts"
1887 depends on FAULT_INJECTION && BLOCK
1889 Provide fault-injection capability on end IO handling. This
1890 will make the block layer "forget" an interrupt as configured,
1891 thus exercising the error handling.
1893 Only works with drivers that use the generic timeout handling,
1894 for others it won't do anything.
1897 bool "Fault-injection capability for futexes"
1899 depends on FAULT_INJECTION && FUTEX
1901 Provide fault-injection capability for futexes.
1903 config FAULT_INJECTION_DEBUG_FS
1904 bool "Debugfs entries for fault-injection capabilities"
1905 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1907 Enable configuration of fault-injection capabilities via debugfs.
1909 config FAIL_FUNCTION
1910 bool "Fault-injection capability for functions"
1911 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1913 Provide function-based fault-injection capability.
1914 This will allow you to override a specific function with a return
1915 with given return value. As a result, function caller will see
1916 an error value and have to handle it. This is useful to test the
1917 error handling in various subsystems.
1919 config FAIL_MMC_REQUEST
1920 bool "Fault-injection capability for MMC IO"
1921 depends on FAULT_INJECTION_DEBUG_FS && MMC
1923 Provide fault-injection capability for MMC IO.
1924 This will make the mmc core return data errors. This is
1925 useful to test the error handling in the mmc block device
1926 and to test how the mmc host driver handles retries from
1930 bool "Fault-injection capability for SunRPC"
1931 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
1933 Provide fault-injection capability for SunRPC and
1936 config FAULT_INJECTION_STACKTRACE_FILTER
1937 bool "stacktrace filter for fault-injection capabilities"
1938 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1941 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1943 Provide stacktrace filter for fault-injection capabilities
1945 config ARCH_HAS_KCOV
1948 An architecture should select this when it can successfully
1949 build and run with CONFIG_KCOV. This typically requires
1950 disabling instrumentation for some early boot code.
1952 config CC_HAS_SANCOV_TRACE_PC
1953 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1957 bool "Code coverage for fuzzing"
1958 depends on ARCH_HAS_KCOV
1959 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1960 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
1961 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
1963 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1964 select OBJTOOL if HAVE_NOINSTR_HACK
1966 KCOV exposes kernel code coverage information in a form suitable
1967 for coverage-guided fuzzing (randomized testing).
1969 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1970 different machines and across reboots. If you need stable PC values,
1971 disable RANDOMIZE_BASE.
1973 For more details, see Documentation/dev-tools/kcov.rst.
1975 config KCOV_ENABLE_COMPARISONS
1976 bool "Enable comparison operands collection by KCOV"
1978 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1980 KCOV also exposes operands of every comparison in the instrumented
1981 code along with operand sizes and PCs of the comparison instructions.
1982 These operands can be used by fuzzing engines to improve the quality
1983 of fuzzing coverage.
1985 config KCOV_INSTRUMENT_ALL
1986 bool "Instrument all code by default"
1990 If you are doing generic system call fuzzing (like e.g. syzkaller),
1991 then you will want to instrument the whole kernel and you should
1992 say y here. If you are doing more targeted fuzzing (like e.g.
1993 filesystem fuzzing with AFL) then you will want to enable coverage
1994 for more specific subsets of files, and should say n here.
1996 config KCOV_IRQ_AREA_SIZE
1997 hex "Size of interrupt coverage collection area in words"
2001 KCOV uses preallocated per-cpu areas to collect coverage from
2002 soft interrupts. This specifies the size of those areas in the
2003 number of unsigned long words.
2005 menuconfig RUNTIME_TESTING_MENU
2006 bool "Runtime Testing"
2009 if RUNTIME_TESTING_MENU
2012 tristate "Linux Kernel Dump Test Tool Module"
2015 This module enables testing of the different dumping mechanisms by
2016 inducing system failures at predefined crash points.
2017 If you don't need it: say N
2018 Choose M here to compile this code as a module. The module will be
2021 Documentation on how to use the module can be found in
2022 Documentation/fault-injection/provoke-crashes.rst
2024 config TEST_LIST_SORT
2025 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2027 default KUNIT_ALL_TESTS
2029 Enable this to turn on 'list_sort()' function test. This test is
2030 executed only once during system boot (so affects only boot time),
2031 or at module load time.
2035 config TEST_MIN_HEAP
2036 tristate "Min heap test"
2037 depends on DEBUG_KERNEL || m
2039 Enable this to turn on min heap function tests. This test is
2040 executed only once during system boot (so affects only boot time),
2041 or at module load time.
2046 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2048 default KUNIT_ALL_TESTS
2050 This option enables the self-test function of 'sort()' at boot,
2051 or at module load time.
2056 tristate "64bit/32bit division and modulo test"
2057 depends on DEBUG_KERNEL || m
2059 Enable this to turn on 'do_div()' function test. This test is
2060 executed only once during system boot (so affects only boot time),
2061 or at module load time.
2065 config KPROBES_SANITY_TEST
2066 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2067 depends on DEBUG_KERNEL
2070 default KUNIT_ALL_TESTS
2072 This option provides for testing basic kprobes functionality on
2073 boot. Samples of kprobe and kretprobe are inserted and
2074 verified for functionality.
2076 Say N if you are unsure.
2078 config FPROBE_SANITY_TEST
2079 bool "Self test for fprobe"
2080 depends on DEBUG_KERNEL
2084 This option will enable testing the fprobe when the system boot.
2085 A series of tests are made to verify that the fprobe is functioning
2088 Say N if you are unsure.
2090 config BACKTRACE_SELF_TEST
2091 tristate "Self test for the backtrace code"
2092 depends on DEBUG_KERNEL
2094 This option provides a kernel module that can be used to test
2095 the kernel stack backtrace code. This option is not useful
2096 for distributions or general kernels, but only for kernel
2097 developers working on architecture code.
2099 Note that if you want to also test saved backtraces, you will
2100 have to enable STACKTRACE as well.
2102 Say N if you are unsure.
2104 config TEST_REF_TRACKER
2105 tristate "Self test for reference tracker"
2106 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2109 This option provides a kernel module performing tests
2110 using reference tracker infrastructure.
2112 Say N if you are unsure.
2115 tristate "Red-Black tree test"
2116 depends on DEBUG_KERNEL
2118 A benchmark measuring the performance of the rbtree library.
2119 Also includes rbtree invariant checks.
2121 config REED_SOLOMON_TEST
2122 tristate "Reed-Solomon library test"
2123 depends on DEBUG_KERNEL || m
2125 select REED_SOLOMON_ENC16
2126 select REED_SOLOMON_DEC16
2128 This option enables the self-test function of rslib at boot,
2129 or at module load time.
2133 config INTERVAL_TREE_TEST
2134 tristate "Interval tree test"
2135 depends on DEBUG_KERNEL
2136 select INTERVAL_TREE
2138 A benchmark measuring the performance of the interval tree library
2141 tristate "Per cpu operations test"
2142 depends on m && DEBUG_KERNEL
2144 Enable this option to build test module which validates per-cpu
2149 config ATOMIC64_SELFTEST
2150 tristate "Perform an atomic64_t self-test"
2152 Enable this option to test the atomic64_t functions at boot or
2153 at module load time.
2157 config ASYNC_RAID6_TEST
2158 tristate "Self test for hardware accelerated raid6 recovery"
2159 depends on ASYNC_RAID6_RECOV
2162 This is a one-shot self test that permutes through the
2163 recovery of all the possible two disk failure scenarios for a
2164 N-disk array. Recovery is performed with the asynchronous
2165 raid6 recovery routines, and will optionally use an offload
2166 engine if one is available.
2171 tristate "Test functions located in the hexdump module at runtime"
2173 config STRING_SELFTEST
2174 tristate "Test string functions at runtime"
2176 config TEST_STRING_HELPERS
2177 tristate "Test functions located in the string_helpers module at runtime"
2180 tristate "Test strscpy*() family of functions at runtime"
2183 tristate "Test kstrto*() family of functions at runtime"
2186 tristate "Test printf() family of functions at runtime"
2189 tristate "Test scanf() family of functions at runtime"
2192 tristate "Test bitmap_*() family of functions at runtime"
2194 Enable this option to test the bitmap functions at boot.
2199 tristate "Test functions located in the uuid module at runtime"
2202 tristate "Test the XArray code at runtime"
2204 config TEST_RHASHTABLE
2205 tristate "Perform selftest on resizable hash table"
2207 Enable this option to test the rhashtable functions at boot.
2212 tristate "Perform selftest on siphash functions"
2214 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2215 functions on boot (or module load).
2217 This is intended to help people writing architecture-specific
2218 optimized versions. If unsure, say N.
2221 tristate "Perform selftest on IDA functions"
2224 tristate "Perform selftest on priority array manager"
2227 Enable this option to test priority array manager on boot
2232 config TEST_IRQ_TIMINGS
2233 bool "IRQ timings selftest"
2234 depends on IRQ_TIMINGS
2236 Enable this option to test the irq timings code on boot.
2241 tristate "Test module loading with 'hello world' module"
2244 This builds the "test_module" module that emits "Hello, world"
2245 on printk when loaded. It is designed to be used for basic
2246 evaluation of the module loading subsystem (for example when
2247 validating module verification). It lacks any extra dependencies,
2248 and will not normally be loaded by the system unless explicitly
2254 tristate "Test module for compilation of bitops operations"
2257 This builds the "test_bitops" module that is much like the
2258 TEST_LKM module except that it does a basic exercise of the
2259 set/clear_bit macros and get_count_order/long to make sure there are
2260 no compiler warnings from C=1 sparse checker or -Wextra
2261 compilations. It has no dependencies and doesn't run or load unless
2262 explicitly requested by name. for example: modprobe test_bitops.
2267 tristate "Test module for stress/performance analysis of vmalloc allocator"
2272 This builds the "test_vmalloc" module that should be used for
2273 stress and performance analysis. So, any new change for vmalloc
2274 subsystem can be evaluated from performance and stability point
2279 config TEST_USER_COPY
2280 tristate "Test user/kernel boundary protections"
2283 This builds the "test_user_copy" module that runs sanity checks
2284 on the copy_to/from_user infrastructure, making sure basic
2285 user/kernel boundary testing is working. If it fails to load,
2286 a regression has been detected in the user/kernel memory boundary
2292 tristate "Test BPF filter functionality"
2295 This builds the "test_bpf" module that runs various test vectors
2296 against the BPF interpreter or BPF JIT compiler depending on the
2297 current setting. This is in particular useful for BPF JIT compiler
2298 development, but also to run regression tests against changes in
2299 the interpreter code. It also enables test stubs for eBPF maps and
2300 verifier used by user space verifier testsuite.
2304 config TEST_BLACKHOLE_DEV
2305 tristate "Test blackhole netdev functionality"
2308 This builds the "test_blackhole_dev" module that validates the
2309 data path through this blackhole netdev.
2313 config FIND_BIT_BENCHMARK
2314 tristate "Test find_bit functions"
2316 This builds the "test_find_bit" module that measure find_*_bit()
2317 functions performance.
2321 config TEST_FIRMWARE
2322 tristate "Test firmware loading via userspace interface"
2323 depends on FW_LOADER
2325 This builds the "test_firmware" module that creates a userspace
2326 interface for testing firmware loading. This can be used to
2327 control the triggering of firmware loading without needing an
2328 actual firmware-using device. The contents can be rechecked by
2334 tristate "sysctl test driver"
2335 depends on PROC_SYSCTL
2337 This builds the "test_sysctl" module. This driver enables to test the
2338 proc sysctl interfaces available to drivers safely without affecting
2339 production knobs which might alter system functionality.
2343 config BITFIELD_KUNIT
2344 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2346 default KUNIT_ALL_TESTS
2348 Enable this option to test the bitfield functions at boot.
2350 KUnit tests run during boot and output the results to the debug log
2351 in TAP format (http://testanything.org/). Only useful for kernel devs
2352 running the KUnit test harness, and not intended for inclusion into a
2355 For more information on KUnit and unit tests in general please refer
2356 to the KUnit documentation in Documentation/dev-tools/kunit/.
2360 config HASH_KUNIT_TEST
2361 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2363 default KUNIT_ALL_TESTS
2365 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2366 integer (<linux/hash.h>) hash functions on boot.
2368 KUnit tests run during boot and output the results to the debug log
2369 in TAP format (https://testanything.org/). Only useful for kernel devs
2370 running the KUnit test harness, and not intended for inclusion into a
2373 For more information on KUnit and unit tests in general please refer
2374 to the KUnit documentation in Documentation/dev-tools/kunit/.
2376 This is intended to help people writing architecture-specific
2377 optimized versions. If unsure, say N.
2379 config RESOURCE_KUNIT_TEST
2380 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2382 default KUNIT_ALL_TESTS
2384 This builds the resource API unit test.
2385 Tests the logic of API provided by resource.c and ioport.h.
2386 For more information on KUnit and unit tests in general please refer
2387 to the KUnit documentation in Documentation/dev-tools/kunit/.
2391 config SYSCTL_KUNIT_TEST
2392 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2394 default KUNIT_ALL_TESTS
2396 This builds the proc sysctl unit test, which runs on boot.
2397 Tests the API contract and implementation correctness of sysctl.
2398 For more information on KUnit and unit tests in general please refer
2399 to the KUnit documentation in Documentation/dev-tools/kunit/.
2403 config LIST_KUNIT_TEST
2404 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2406 default KUNIT_ALL_TESTS
2408 This builds the linked list KUnit test suite.
2409 It tests that the API and basic functionality of the list_head type
2410 and associated macros.
2412 KUnit tests run during boot and output the results to the debug log
2413 in TAP format (https://testanything.org/). Only useful for kernel devs
2414 running the KUnit test harness, and not intended for inclusion into a
2417 For more information on KUnit and unit tests in general please refer
2418 to the KUnit documentation in Documentation/dev-tools/kunit/.
2422 config LINEAR_RANGES_TEST
2423 tristate "KUnit test for linear_ranges"
2425 select LINEAR_RANGES
2427 This builds the linear_ranges unit test, which runs on boot.
2428 Tests the linear_ranges logic correctness.
2429 For more information on KUnit and unit tests in general please refer
2430 to the KUnit documentation in Documentation/dev-tools/kunit/.
2434 config CMDLINE_KUNIT_TEST
2435 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2437 default KUNIT_ALL_TESTS
2439 This builds the cmdline API unit test.
2440 Tests the logic of API provided by cmdline.c.
2441 For more information on KUnit and unit tests in general please refer
2442 to the KUnit documentation in Documentation/dev-tools/kunit/.
2447 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2449 default KUNIT_ALL_TESTS
2451 This builds the bits unit test.
2452 Tests the logic of macros defined in bits.h.
2453 For more information on KUnit and unit tests in general please refer
2454 to the KUnit documentation in Documentation/dev-tools/kunit/.
2458 config SLUB_KUNIT_TEST
2459 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2460 depends on SLUB_DEBUG && KUNIT
2461 default KUNIT_ALL_TESTS
2463 This builds SLUB allocator unit test.
2464 Tests SLUB cache debugging functionality.
2465 For more information on KUnit and unit tests in general please refer
2466 to the KUnit documentation in Documentation/dev-tools/kunit/.
2470 config RATIONAL_KUNIT_TEST
2471 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2472 depends on KUNIT && RATIONAL
2473 default KUNIT_ALL_TESTS
2475 This builds the rational math unit test.
2476 For more information on KUnit and unit tests in general please refer
2477 to the KUnit documentation in Documentation/dev-tools/kunit/.
2481 config MEMCPY_KUNIT_TEST
2482 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2484 default KUNIT_ALL_TESTS
2486 Builds unit tests for memcpy(), memmove(), and memset() functions.
2487 For more information on KUnit and unit tests in general please refer
2488 to the KUnit documentation in Documentation/dev-tools/kunit/.
2492 config OVERFLOW_KUNIT_TEST
2493 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2495 default KUNIT_ALL_TESTS
2497 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2500 For more information on KUnit and unit tests in general please refer
2501 to the KUnit documentation in Documentation/dev-tools/kunit/.
2505 config STACKINIT_KUNIT_TEST
2506 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2508 default KUNIT_ALL_TESTS
2510 Test if the kernel is zero-initializing stack variables and
2511 padding. Coverage is controlled by compiler flags,
2512 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2513 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2514 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2517 tristate "udelay test driver"
2519 This builds the "udelay_test" module that helps to make sure
2520 that udelay() is working properly.
2524 config TEST_STATIC_KEYS
2525 tristate "Test static keys"
2528 Test the static key interfaces.
2533 tristate "kmod stress tester"
2535 depends on NETDEVICES && NET_CORE && INET # for TUN
2537 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2543 Test the kernel's module loading mechanism: kmod. kmod implements
2544 support to load modules using the Linux kernel's usermode helper.
2545 This test provides a series of tests against kmod.
2547 Although technically you can either build test_kmod as a module or
2548 into the kernel we disallow building it into the kernel since
2549 it stress tests request_module() and this will very likely cause
2550 some issues by taking over precious threads available from other
2551 module load requests, ultimately this could be fatal.
2555 tools/testing/selftests/kmod/kmod.sh --help
2559 config TEST_DEBUG_VIRTUAL
2560 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2561 depends on DEBUG_VIRTUAL
2563 Test the kernel's ability to detect incorrect calls to
2564 virt_to_phys() done against the non-linear part of the
2565 kernel's virtual address map.
2569 config TEST_MEMCAT_P
2570 tristate "Test memcat_p() helper function"
2572 Test the memcat_p() helper for correctly merging two
2573 pointer arrays together.
2577 config TEST_LIVEPATCH
2578 tristate "Test livepatching"
2580 depends on DYNAMIC_DEBUG
2581 depends on LIVEPATCH
2584 Test kernel livepatching features for correctness. The tests will
2585 load test modules that will be livepatched in various scenarios.
2587 To run all the livepatching tests:
2589 make -C tools/testing/selftests TARGETS=livepatch run_tests
2591 Alternatively, individual tests may be invoked:
2593 tools/testing/selftests/livepatch/test-callbacks.sh
2594 tools/testing/selftests/livepatch/test-livepatch.sh
2595 tools/testing/selftests/livepatch/test-shadow-vars.sh
2600 tristate "Perform selftest on object aggreration manager"
2604 Enable this option to test object aggregation manager on boot
2608 tristate "Test heap/page initialization"
2610 Test if the kernel is zero-initializing heap and page allocations.
2611 This can be useful to test init_on_alloc and init_on_free features.
2616 tristate "Test HMM (Heterogeneous Memory Management)"
2617 depends on TRANSPARENT_HUGEPAGE
2618 depends on DEVICE_PRIVATE
2622 This is a pseudo device driver solely for testing HMM.
2623 Say M here if you want to build the HMM test module.
2624 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2628 config TEST_FREE_PAGES
2629 tristate "Test freeing pages"
2631 Test that a memory leak does not occur due to a race between
2632 freeing a block of pages and a speculative page reference.
2633 Loading this module is safe if your kernel has the bug fixed.
2634 If the bug is not fixed, it will leak gigabytes of memory and
2635 probably OOM your system.
2638 tristate "Test floating point operations in kernel space"
2639 depends on X86 && !KCOV_INSTRUMENT_ALL
2641 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2642 which will trigger a sequence of floating point operations. This is used
2643 for self-testing floating point control register setting in
2648 config TEST_CLOCKSOURCE_WATCHDOG
2649 tristate "Test clocksource watchdog in kernel space"
2650 depends on CLOCKSOURCE_WATCHDOG
2652 Enable this option to create a kernel module that will trigger
2653 a test of the clocksource watchdog. This module may be loaded
2654 via modprobe or insmod in which case it will run upon being
2655 loaded, or it may be built in, in which case it will run
2660 endif # RUNTIME_TESTING_MENU
2662 config ARCH_USE_MEMTEST
2665 An architecture should select this when it uses early_memtest()
2666 during boot process.
2670 depends on ARCH_USE_MEMTEST
2672 This option adds a kernel parameter 'memtest', which allows memtest
2673 to be set and executed.
2674 memtest=0, mean disabled; -- default
2675 memtest=1, mean do 1 test pattern;
2677 memtest=17, mean do 17 test patterns.
2678 If you are unsure how to answer this question, answer N.
2682 config HYPERV_TESTING
2683 bool "Microsoft Hyper-V driver testing"
2685 depends on HYPERV && DEBUG_FS
2687 Select this option to enable Hyper-V vmbus testing.
2689 endmenu # "Kernel Testing and Coverage"
2691 source "Documentation/Kconfig"
2693 endmenu # Kernel hacking
projects / linux-2.6-microblaze.git / blob