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"
211 menu "Compile-time checks and compiler options"
214 bool "Compile the kernel with debug info"
215 depends on DEBUG_KERNEL && !COMPILE_TEST
217 If you say Y here the resulting kernel image will include
218 debugging info resulting in a larger kernel image.
219 This adds debug symbols to the kernel and modules (gcc -g), and
220 is needed if you intend to use kernel crashdump or binary object
221 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
222 Say Y here only if you plan to debug the kernel.
228 config DEBUG_INFO_REDUCED
229 bool "Reduce debugging information"
231 If you say Y here gcc is instructed to generate less debugging
232 information for structure types. This means that tools that
233 need full debugging information (like kgdb or systemtap) won't
234 be happy. But if you merely need debugging information to
235 resolve line numbers there is no loss. Advantage is that
236 build directory object sizes shrink dramatically over a full
237 DEBUG_INFO build and compile times are reduced too.
238 Only works with newer gcc versions.
240 config DEBUG_INFO_COMPRESSED
241 bool "Compressed debugging information"
242 depends on $(cc-option,-gz=zlib)
243 depends on $(ld-option,--compress-debug-sections=zlib)
245 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
246 5.0+, binutils 2.26+, and zlib.
248 Users of dpkg-deb via scripts/package/builddeb may find an increase in
249 size of their debug .deb packages with this config set, due to the
250 debug info being compressed with zlib, then the object files being
251 recompressed with a different compression scheme. But this is still
252 preferable to setting $KDEB_COMPRESS to "none" which would be even
255 config DEBUG_INFO_SPLIT
256 bool "Produce split debuginfo in .dwo files"
257 depends on $(cc-option,-gsplit-dwarf)
259 Generate debug info into separate .dwo files. This significantly
260 reduces the build directory size for builds with DEBUG_INFO,
261 because it stores the information only once on disk in .dwo
262 files instead of multiple times in object files and executables.
263 In addition the debug information is also compressed.
265 Requires recent gcc (4.7+) and recent gdb/binutils.
266 Any tool that packages or reads debug information would need
267 to know about the .dwo files and include them.
268 Incompatible with older versions of ccache.
271 prompt "DWARF version"
273 Which version of DWARF debug info to emit.
275 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
276 bool "Rely on the toolchain's implicit default DWARF version"
278 The implicit default version of DWARF debug info produced by a
279 toolchain changes over time.
281 This can break consumers of the debug info that haven't upgraded to
282 support newer revisions, and prevent testing newer versions, but
283 those should be less common scenarios.
287 config DEBUG_INFO_DWARF4
288 bool "Generate DWARF Version 4 debuginfo"
290 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
292 If you have consumers of DWARF debug info that are not ready for
293 newer revisions of DWARF, you may wish to choose this or have your
296 config DEBUG_INFO_DWARF5
297 bool "Generate DWARF Version 5 debuginfo"
298 depends on GCC_VERSION >= 50000 || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
299 depends on !DEBUG_INFO_BTF
301 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
302 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
303 draft features until 7.0), and gdb 8.0+.
305 Changes to the structure of debug info in Version 5 allow for around
306 15-18% savings in resulting image and debug info section sizes as
307 compared to DWARF Version 4. DWARF Version 5 standardizes previous
308 extensions such as accelerators for symbol indexing and the format
309 for fission (.dwo/.dwp) files. Users may not want to select this
310 config if they rely on tooling that has not yet been updated to
311 support DWARF Version 5.
313 endchoice # "DWARF version"
315 config DEBUG_INFO_BTF
316 bool "Generate BTF typeinfo"
317 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
318 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
320 Generate deduplicated BTF type information from DWARF debug info.
321 Turning this on expects presence of pahole tool, which will convert
322 DWARF type info into equivalent deduplicated BTF type info.
324 config PAHOLE_HAS_SPLIT_BTF
325 def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119")
327 config PAHOLE_HAS_ZEROSIZE_PERCPU_SUPPORT
328 def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "122")
330 config DEBUG_INFO_BTF_MODULES
332 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
334 Generate compact split BTF type information for kernel modules.
337 bool "Provide GDB scripts for kernel debugging"
339 This creates the required links to GDB helper scripts in the
340 build directory. If you load vmlinux into gdb, the helper
341 scripts will be automatically imported by gdb as well, and
342 additional functions are available to analyze a Linux kernel
343 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
349 int "Warn for stack frames larger than"
351 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
352 default 1280 if (!64BIT && PARISC)
353 default 1024 if (!64BIT && !PARISC)
354 default 2048 if 64BIT
356 Tell gcc to warn at build time for stack frames larger than this.
357 Setting this too low will cause a lot of warnings.
358 Setting it to 0 disables the warning.
360 config STRIP_ASM_SYMS
361 bool "Strip assembler-generated symbols during link"
364 Strip internal assembler-generated symbols during a link (symbols
365 that look like '.Lxxx') so they don't pollute the output of
366 get_wchan() and suchlike.
369 bool "Generate readable assembler code"
370 depends on DEBUG_KERNEL
372 Disable some compiler optimizations that tend to generate human unreadable
373 assembler output. This may make the kernel slightly slower, but it helps
374 to keep kernel developers who have to stare a lot at assembler listings
377 config HEADERS_INSTALL
378 bool "Install uapi headers to usr/include"
381 This option will install uapi headers (headers exported to user-space)
382 into the usr/include directory for use during the kernel build.
383 This is unneeded for building the kernel itself, but needed for some
384 user-space program samples. It is also needed by some features such
385 as uapi header sanity checks.
387 config DEBUG_SECTION_MISMATCH
388 bool "Enable full Section mismatch analysis"
390 The section mismatch analysis checks if there are illegal
391 references from one section to another section.
392 During linktime or runtime, some sections are dropped;
393 any use of code/data previously in these sections would
394 most likely result in an oops.
395 In the code, functions and variables are annotated with
396 __init,, etc. (see the full list in include/linux/init.h),
397 which results in the code/data being placed in specific sections.
398 The section mismatch analysis is always performed after a full
399 kernel build, and enabling this option causes the following
400 additional step to occur:
401 - Add the option -fno-inline-functions-called-once to gcc commands.
402 When inlining a function annotated with __init in a non-init
403 function, we would lose the section information and thus
404 the analysis would not catch the illegal reference.
405 This option tells gcc to inline less (but it does result in
408 config SECTION_MISMATCH_WARN_ONLY
409 bool "Make section mismatch errors non-fatal"
412 If you say N here, the build process will fail if there are any
413 section mismatch, instead of just throwing warnings.
417 config DEBUG_FORCE_FUNCTION_ALIGN_64B
418 bool "Force all function address 64B aligned" if EXPERT
420 There are cases that a commit from one domain changes the function
421 address alignment of other domains, and cause magic performance
422 bump (regression or improvement). Enable this option will help to
423 verify if the bump is caused by function alignment changes, while
424 it will slightly increase the kernel size and affect icache usage.
426 It is mainly for debug and performance tuning use.
429 # Select this config option from the architecture Kconfig, if it
430 # is preferred to always offer frame pointers as a config
431 # option on the architecture (regardless of KERNEL_DEBUG):
433 config ARCH_WANT_FRAME_POINTERS
437 bool "Compile the kernel with frame pointers"
438 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
439 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
441 If you say Y here the resulting kernel image will be slightly
442 larger and slower, but it gives very useful debugging information
443 in case of kernel bugs. (precise oopses/stacktraces/warnings)
445 config STACK_VALIDATION
446 bool "Compile-time stack metadata validation"
447 depends on HAVE_STACK_VALIDATION
450 Add compile-time checks to validate stack metadata, including frame
451 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
452 that runtime stack traces are more reliable.
454 This is also a prerequisite for generation of ORC unwind data, which
455 is needed for CONFIG_UNWINDER_ORC.
457 For more information, see
458 tools/objtool/Documentation/stack-validation.txt.
460 config VMLINUX_VALIDATION
462 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
466 bool "Generate vmlinux.map file when linking"
469 Selecting this option will pass "-Map=vmlinux.map" to ld
470 when linking vmlinux. That file can be useful for verifying
471 and debugging magic section games, and for seeing which
472 pieces of code get eliminated with
473 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
475 config DEBUG_FORCE_WEAK_PER_CPU
476 bool "Force weak per-cpu definitions"
477 depends on DEBUG_KERNEL
479 s390 and alpha require percpu variables in modules to be
480 defined weak to work around addressing range issue which
481 puts the following two restrictions on percpu variable
484 1. percpu symbols must be unique whether static or not
485 2. percpu variables can't be defined inside a function
487 To ensure that generic code follows the above rules, this
488 option forces all percpu variables to be defined as weak.
490 endmenu # "Compiler options"
492 menu "Generic Kernel Debugging Instruments"
495 bool "Magic SysRq key"
498 If you say Y here, you will have some control over the system even
499 if the system crashes for example during kernel debugging (e.g., you
500 will be able to flush the buffer cache to disk, reboot the system
501 immediately or dump some status information). This is accomplished
502 by pressing various keys while holding SysRq (Alt+PrintScreen). It
503 also works on a serial console (on PC hardware at least), if you
504 send a BREAK and then within 5 seconds a command keypress. The
505 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
506 Don't say Y unless you really know what this hack does.
508 config MAGIC_SYSRQ_DEFAULT_ENABLE
509 hex "Enable magic SysRq key functions by default"
510 depends on MAGIC_SYSRQ
513 Specifies which SysRq key functions are enabled by default.
514 This may be set to 1 or 0 to enable or disable them all, or
515 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
517 config MAGIC_SYSRQ_SERIAL
518 bool "Enable magic SysRq key over serial"
519 depends on MAGIC_SYSRQ
522 Many embedded boards have a disconnected TTL level serial which can
523 generate some garbage that can lead to spurious false sysrq detects.
524 This option allows you to decide whether you want to enable the
527 config MAGIC_SYSRQ_SERIAL_SEQUENCE
528 string "Char sequence that enables magic SysRq over serial"
529 depends on MAGIC_SYSRQ_SERIAL
532 Specifies a sequence of characters that can follow BREAK to enable
533 SysRq on a serial console.
535 If unsure, leave an empty string and the option will not be enabled.
538 bool "Debug Filesystem"
540 debugfs is a virtual file system that kernel developers use to put
541 debugging files into. Enable this option to be able to read and
542 write to these files.
544 For detailed documentation on the debugfs API, see
545 Documentation/filesystems/.
550 prompt "Debugfs default access"
552 default DEBUG_FS_ALLOW_ALL
554 This selects the default access restrictions for debugfs.
555 It can be overridden with kernel command line option
556 debugfs=[on,no-mount,off]. The restrictions apply for API access
557 and filesystem registration.
559 config DEBUG_FS_ALLOW_ALL
562 No restrictions apply. Both API and filesystem registration
563 is on. This is the normal default operation.
565 config DEBUG_FS_DISALLOW_MOUNT
566 bool "Do not register debugfs as filesystem"
568 The API is open but filesystem is not loaded. Clients can still do
569 their work and read with debug tools that do not need
572 config DEBUG_FS_ALLOW_NONE
575 Access is off. Clients get -PERM when trying to create nodes in
576 debugfs tree and debugfs is not registered as a filesystem.
577 Client can then back-off or continue without debugfs access.
581 source "lib/Kconfig.kgdb"
582 source "lib/Kconfig.ubsan"
583 source "lib/Kconfig.kcsan"
588 bool "Kernel debugging"
590 Say Y here if you are developing drivers or trying to debug and
591 identify kernel problems.
594 bool "Miscellaneous debug code"
596 depends on DEBUG_KERNEL
598 Say Y here if you need to enable miscellaneous debug code that should
599 be under a more specific debug option but isn't.
602 menu "Memory Debugging"
604 source "mm/Kconfig.debug"
607 bool "Debug object operations"
608 depends on DEBUG_KERNEL
610 If you say Y here, additional code will be inserted into the
611 kernel to track the life time of various objects and validate
612 the operations on those objects.
614 config DEBUG_OBJECTS_SELFTEST
615 bool "Debug objects selftest"
616 depends on DEBUG_OBJECTS
618 This enables the selftest of the object debug code.
620 config DEBUG_OBJECTS_FREE
621 bool "Debug objects in freed memory"
622 depends on DEBUG_OBJECTS
624 This enables checks whether a k/v free operation frees an area
625 which contains an object which has not been deactivated
626 properly. This can make kmalloc/kfree-intensive workloads
629 config DEBUG_OBJECTS_TIMERS
630 bool "Debug timer objects"
631 depends on DEBUG_OBJECTS
633 If you say Y here, additional code will be inserted into the
634 timer routines to track the life time of timer objects and
635 validate the timer operations.
637 config DEBUG_OBJECTS_WORK
638 bool "Debug work objects"
639 depends on DEBUG_OBJECTS
641 If you say Y here, additional code will be inserted into the
642 work queue routines to track the life time of work objects and
643 validate the work operations.
645 config DEBUG_OBJECTS_RCU_HEAD
646 bool "Debug RCU callbacks objects"
647 depends on DEBUG_OBJECTS
649 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
651 config DEBUG_OBJECTS_PERCPU_COUNTER
652 bool "Debug percpu counter objects"
653 depends on DEBUG_OBJECTS
655 If you say Y here, additional code will be inserted into the
656 percpu counter routines to track the life time of percpu counter
657 objects and validate the percpu counter operations.
659 config DEBUG_OBJECTS_ENABLE_DEFAULT
660 int "debug_objects bootup default value (0-1)"
663 depends on DEBUG_OBJECTS
665 Debug objects boot parameter default value
668 bool "Debug slab memory allocations"
669 depends on DEBUG_KERNEL && SLAB
671 Say Y here to have the kernel do limited verification on memory
672 allocation as well as poisoning memory on free to catch use of freed
673 memory. This can make kmalloc/kfree-intensive workloads much slower.
676 bool "SLUB debugging on by default"
677 depends on SLUB && SLUB_DEBUG
680 Boot with debugging on by default. SLUB boots by default with
681 the runtime debug capabilities switched off. Enabling this is
682 equivalent to specifying the "slub_debug" parameter on boot.
683 There is no support for more fine grained debug control like
684 possible with slub_debug=xxx. SLUB debugging may be switched
685 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
690 bool "Enable SLUB performance statistics"
691 depends on SLUB && SYSFS
693 SLUB statistics are useful to debug SLUBs allocation behavior in
694 order find ways to optimize the allocator. This should never be
695 enabled for production use since keeping statistics slows down
696 the allocator by a few percentage points. The slabinfo command
697 supports the determination of the most active slabs to figure
698 out which slabs are relevant to a particular load.
699 Try running: slabinfo -DA
701 config HAVE_DEBUG_KMEMLEAK
704 config DEBUG_KMEMLEAK
705 bool "Kernel memory leak detector"
706 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
708 select STACKTRACE if STACKTRACE_SUPPORT
712 Say Y here if you want to enable the memory leak
713 detector. The memory allocation/freeing is traced in a way
714 similar to the Boehm's conservative garbage collector, the
715 difference being that the orphan objects are not freed but
716 only shown in /sys/kernel/debug/kmemleak. Enabling this
717 feature will introduce an overhead to memory
718 allocations. See Documentation/dev-tools/kmemleak.rst for more
721 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
722 of finding leaks due to the slab objects poisoning.
724 In order to access the kmemleak file, debugfs needs to be
725 mounted (usually at /sys/kernel/debug).
727 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
728 int "Kmemleak memory pool size"
729 depends on DEBUG_KMEMLEAK
733 Kmemleak must track all the memory allocations to avoid
734 reporting false positives. Since memory may be allocated or
735 freed before kmemleak is fully initialised, use a static pool
736 of metadata objects to track such callbacks. After kmemleak is
737 fully initialised, this memory pool acts as an emergency one
738 if slab allocations fail.
740 config DEBUG_KMEMLEAK_TEST
741 tristate "Simple test for the kernel memory leak detector"
742 depends on DEBUG_KMEMLEAK && m
744 This option enables a module that explicitly leaks memory.
748 config DEBUG_KMEMLEAK_DEFAULT_OFF
749 bool "Default kmemleak to off"
750 depends on DEBUG_KMEMLEAK
752 Say Y here to disable kmemleak by default. It can then be enabled
753 on the command line via kmemleak=on.
755 config DEBUG_KMEMLEAK_AUTO_SCAN
756 bool "Enable kmemleak auto scan thread on boot up"
758 depends on DEBUG_KMEMLEAK
760 Depending on the cpu, kmemleak scan may be cpu intensive and can
761 stall user tasks at times. This option enables/disables automatic
762 kmemleak scan at boot up.
764 Say N here to disable kmemleak auto scan thread to stop automatic
765 scanning. Disabling this option disables automatic reporting of
770 config DEBUG_STACK_USAGE
771 bool "Stack utilization instrumentation"
772 depends on DEBUG_KERNEL && !IA64
774 Enables the display of the minimum amount of free stack which each
775 task has ever had available in the sysrq-T and sysrq-P debug output.
777 This option will slow down process creation somewhat.
779 config SCHED_STACK_END_CHECK
780 bool "Detect stack corruption on calls to schedule()"
781 depends on DEBUG_KERNEL
784 This option checks for a stack overrun on calls to schedule().
785 If the stack end location is found to be over written always panic as
786 the content of the corrupted region can no longer be trusted.
787 This is to ensure no erroneous behaviour occurs which could result in
788 data corruption or a sporadic crash at a later stage once the region
789 is examined. The runtime overhead introduced is minimal.
791 config ARCH_HAS_DEBUG_VM_PGTABLE
794 An architecture should select this when it can successfully
795 build and run DEBUG_VM_PGTABLE.
799 depends on DEBUG_KERNEL
801 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance.
806 config DEBUG_VM_VMACACHE
807 bool "Debug VMA caching"
810 Enable this to turn on VMA caching debug information. Doing so
811 can cause significant overhead, so only enable it in non-production
817 bool "Debug VM red-black trees"
820 Enable VM red-black tree debugging information and extra validations.
824 config DEBUG_VM_PGFLAGS
825 bool "Debug page-flags operations"
828 Enables extra validation on page flags operations.
832 config DEBUG_VM_PGTABLE
833 bool "Debug arch page table for semantics compliance"
835 depends on ARCH_HAS_DEBUG_VM_PGTABLE
836 default y if DEBUG_VM
838 This option provides a debug method which can be used to test
839 architecture page table helper functions on various platforms in
840 verifying if they comply with expected generic MM semantics. This
841 will help architecture code in making sure that any changes or
842 new additions of these helpers still conform to expected
843 semantics of the generic MM. Platforms will have to opt in for
844 this through ARCH_HAS_DEBUG_VM_PGTABLE.
848 config ARCH_HAS_DEBUG_VIRTUAL
852 bool "Debug VM translations"
853 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
855 Enable some costly sanity checks in virtual to page code. This can
856 catch mistakes with virt_to_page() and friends.
860 config DEBUG_NOMMU_REGIONS
861 bool "Debug the global anon/private NOMMU mapping region tree"
862 depends on DEBUG_KERNEL && !MMU
864 This option causes the global tree of anonymous and private mapping
865 regions to be regularly checked for invalid topology.
867 config DEBUG_MEMORY_INIT
868 bool "Debug memory initialisation" if EXPERT
871 Enable this for additional checks during memory initialisation.
872 The sanity checks verify aspects of the VM such as the memory model
873 and other information provided by the architecture. Verbose
874 information will be printed at KERN_DEBUG loglevel depending
875 on the mminit_loglevel= command-line option.
879 config MEMORY_NOTIFIER_ERROR_INJECT
880 tristate "Memory hotplug notifier error injection module"
881 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
883 This option provides the ability to inject artificial errors to
884 memory hotplug notifier chain callbacks. It is controlled through
885 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
887 If the notifier call chain should be failed with some events
888 notified, write the error code to "actions/<notifier event>/error".
890 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
892 # cd /sys/kernel/debug/notifier-error-inject/memory
893 # echo -12 > actions/MEM_GOING_OFFLINE/error
894 # echo offline > /sys/devices/system/memory/memoryXXX/state
895 bash: echo: write error: Cannot allocate memory
897 To compile this code as a module, choose M here: the module will
898 be called memory-notifier-error-inject.
902 config DEBUG_PER_CPU_MAPS
903 bool "Debug access to per_cpu maps"
904 depends on DEBUG_KERNEL
907 Say Y to verify that the per_cpu map being accessed has
908 been set up. This adds a fair amount of code to kernel memory
909 and decreases performance.
913 config DEBUG_KMAP_LOCAL
914 bool "Debug kmap_local temporary mappings"
915 depends on DEBUG_KERNEL && KMAP_LOCAL
917 This option enables additional error checking for the kmap_local
918 infrastructure. Disable for production use.
920 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
923 config DEBUG_KMAP_LOCAL_FORCE_MAP
924 bool "Enforce kmap_local temporary mappings"
925 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
927 select DEBUG_KMAP_LOCAL
929 This option enforces temporary mappings through the kmap_local
930 mechanism for non-highmem pages and on non-highmem systems.
931 Disable this for production systems!
934 bool "Highmem debugging"
935 depends on DEBUG_KERNEL && HIGHMEM
936 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
937 select DEBUG_KMAP_LOCAL
939 This option enables additional error checking for high memory
940 systems. Disable for production systems.
942 config HAVE_DEBUG_STACKOVERFLOW
945 config DEBUG_STACKOVERFLOW
946 bool "Check for stack overflows"
947 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
949 Say Y here if you want to check for overflows of kernel, IRQ
950 and exception stacks (if your architecture uses them). This
951 option will show detailed messages if free stack space drops
952 below a certain limit.
954 These kinds of bugs usually occur when call-chains in the
955 kernel get too deep, especially when interrupts are
958 Use this in cases where you see apparently random memory
959 corruption, especially if it appears in 'struct thread_info'
961 If in doubt, say "N".
963 source "lib/Kconfig.kasan"
964 source "lib/Kconfig.kfence"
966 endmenu # "Memory Debugging"
969 bool "Debug shared IRQ handlers"
970 depends on DEBUG_KERNEL
972 Enable this to generate a spurious interrupt just before a shared
973 interrupt handler is deregistered (generating one when registering
974 is currently disabled). Drivers need to handle this correctly. Some
975 don't and need to be caught.
977 menu "Debug Oops, Lockups and Hangs"
982 Say Y here to enable the kernel to panic when it oopses. This
983 has the same effect as setting oops=panic on the kernel command
986 This feature is useful to ensure that the kernel does not do
987 anything erroneous after an oops which could result in data
988 corruption or other issues.
992 config PANIC_ON_OOPS_VALUE
995 default 0 if !PANIC_ON_OOPS
996 default 1 if PANIC_ON_OOPS
1002 Set the timeout value (in seconds) until a reboot occurs when
1003 the kernel panics. If n = 0, then we wait forever. A timeout
1004 value n > 0 will wait n seconds before rebooting, while a timeout
1005 value n < 0 will reboot immediately.
1007 config LOCKUP_DETECTOR
1010 config SOFTLOCKUP_DETECTOR
1011 bool "Detect Soft Lockups"
1012 depends on DEBUG_KERNEL && !S390
1013 select LOCKUP_DETECTOR
1015 Say Y here to enable the kernel to act as a watchdog to detect
1018 Softlockups are bugs that cause the kernel to loop in kernel
1019 mode for more than 20 seconds, without giving other tasks a
1020 chance to run. The current stack trace is displayed upon
1021 detection and the system will stay locked up.
1023 config BOOTPARAM_SOFTLOCKUP_PANIC
1024 bool "Panic (Reboot) On Soft Lockups"
1025 depends on SOFTLOCKUP_DETECTOR
1027 Say Y here to enable the kernel to panic on "soft lockups",
1028 which are bugs that cause the kernel to loop in kernel
1029 mode for more than 20 seconds (configurable using the watchdog_thresh
1030 sysctl), without giving other tasks a chance to run.
1032 The panic can be used in combination with panic_timeout,
1033 to cause the system to reboot automatically after a
1034 lockup has been detected. This feature is useful for
1035 high-availability systems that have uptime guarantees and
1036 where a lockup must be resolved ASAP.
1040 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
1042 depends on SOFTLOCKUP_DETECTOR
1044 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
1045 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
1047 config HARDLOCKUP_DETECTOR_PERF
1049 select SOFTLOCKUP_DETECTOR
1052 # Enables a timestamp based low pass filter to compensate for perf based
1053 # hard lockup detection which runs too fast due to turbo modes.
1055 config HARDLOCKUP_CHECK_TIMESTAMP
1059 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1060 # lockup detector rather than the perf based detector.
1062 config HARDLOCKUP_DETECTOR
1063 bool "Detect Hard Lockups"
1064 depends on DEBUG_KERNEL && !S390
1065 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1066 select LOCKUP_DETECTOR
1067 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1068 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1070 Say Y here to enable the kernel to act as a watchdog to detect
1073 Hardlockups are bugs that cause the CPU to loop in kernel mode
1074 for more than 10 seconds, without letting other interrupts have a
1075 chance to run. The current stack trace is displayed upon detection
1076 and the system will stay locked up.
1078 config BOOTPARAM_HARDLOCKUP_PANIC
1079 bool "Panic (Reboot) On Hard Lockups"
1080 depends on HARDLOCKUP_DETECTOR
1082 Say Y here to enable the kernel to panic on "hard lockups",
1083 which are bugs that cause the kernel to loop in kernel
1084 mode with interrupts disabled for more than 10 seconds (configurable
1085 using the watchdog_thresh sysctl).
1089 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1091 depends on HARDLOCKUP_DETECTOR
1093 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1094 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
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.
1143 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1145 depends on DETECT_HUNG_TASK
1147 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1148 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1151 bool "Detect Workqueue Stalls"
1152 depends on DEBUG_KERNEL
1154 Say Y here to enable stall detection on workqueues. If a
1155 worker pool doesn't make forward progress on a pending work
1156 item for over a given amount of time, 30s by default, a
1157 warning message is printed along with dump of workqueue
1158 state. This can be configured through kernel parameter
1159 "workqueue.watchdog_thresh" and its sysfs counterpart.
1162 tristate "Test module to generate lockups"
1165 This builds the "test_lockup" module that helps to make sure
1166 that watchdogs and lockup detectors are working properly.
1168 Depending on module parameters it could emulate soft or hard
1169 lockup, "hung task", or locking arbitrary lock for a long time.
1170 Also it could generate series of lockups with cooling-down periods.
1174 endmenu # "Debug lockups and hangs"
1176 menu "Scheduler Debugging"
1179 bool "Collect scheduler debugging info"
1180 depends on DEBUG_KERNEL && PROC_FS
1183 If you say Y here, the /proc/sched_debug file will be provided
1184 that can help debug the scheduler. The runtime overhead of this
1192 bool "Collect scheduler statistics"
1193 depends on DEBUG_KERNEL && PROC_FS
1196 If you say Y here, additional code will be inserted into the
1197 scheduler and related routines to collect statistics about
1198 scheduler behavior and provide them in /proc/schedstat. These
1199 stats may be useful for both tuning and debugging the scheduler
1200 If you aren't debugging the scheduler or trying to tune a specific
1201 application, you can say N to avoid the very slight overhead
1206 config DEBUG_TIMEKEEPING
1207 bool "Enable extra timekeeping sanity checking"
1209 This option will enable additional timekeeping sanity checks
1210 which may be helpful when diagnosing issues where timekeeping
1211 problems are suspected.
1213 This may include checks in the timekeeping hotpaths, so this
1214 option may have a (very small) performance impact to some
1219 config DEBUG_PREEMPT
1220 bool "Debug preemptible kernel"
1221 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1224 If you say Y here then the kernel will use a debug variant of the
1225 commonly used smp_processor_id() function and will print warnings
1226 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1227 will detect preemption count underflows.
1229 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1231 config LOCK_DEBUGGING_SUPPORT
1233 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1236 config PROVE_LOCKING
1237 bool "Lock debugging: prove locking correctness"
1238 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1240 select DEBUG_SPINLOCK
1241 select DEBUG_MUTEXES
1242 select DEBUG_RT_MUTEXES if RT_MUTEXES
1244 select DEBUG_WW_MUTEX_SLOWPATH
1245 select DEBUG_LOCK_ALLOC
1246 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1247 select TRACE_IRQFLAGS
1250 This feature enables the kernel to prove that all locking
1251 that occurs in the kernel runtime is mathematically
1252 correct: that under no circumstance could an arbitrary (and
1253 not yet triggered) combination of observed locking
1254 sequences (on an arbitrary number of CPUs, running an
1255 arbitrary number of tasks and interrupt contexts) cause a
1258 In short, this feature enables the kernel to report locking
1259 related deadlocks before they actually occur.
1261 The proof does not depend on how hard and complex a
1262 deadlock scenario would be to trigger: how many
1263 participant CPUs, tasks and irq-contexts would be needed
1264 for it to trigger. The proof also does not depend on
1265 timing: if a race and a resulting deadlock is possible
1266 theoretically (no matter how unlikely the race scenario
1267 is), it will be proven so and will immediately be
1268 reported by the kernel (once the event is observed that
1269 makes the deadlock theoretically possible).
1271 If a deadlock is impossible (i.e. the locking rules, as
1272 observed by the kernel, are mathematically correct), the
1273 kernel reports nothing.
1275 NOTE: this feature can also be enabled for rwlocks, mutexes
1276 and rwsems - in which case all dependencies between these
1277 different locking variants are observed and mapped too, and
1278 the proof of observed correctness is also maintained for an
1279 arbitrary combination of these separate locking variants.
1281 For more details, see Documentation/locking/lockdep-design.rst.
1283 config PROVE_RAW_LOCK_NESTING
1284 bool "Enable raw_spinlock - spinlock nesting checks"
1285 depends on PROVE_LOCKING
1288 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1289 that the lock nesting rules for PREEMPT_RT enabled kernels are
1292 NOTE: There are known nesting problems. So if you enable this
1293 option expect lockdep splats until these problems have been fully
1294 addressed which is work in progress. This config switch allows to
1295 identify and analyze these problems. It will be removed and the
1296 check permanently enabled once the main issues have been fixed.
1298 If unsure, select N.
1301 bool "Lock usage statistics"
1302 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1304 select DEBUG_SPINLOCK
1305 select DEBUG_MUTEXES
1306 select DEBUG_RT_MUTEXES if RT_MUTEXES
1307 select DEBUG_LOCK_ALLOC
1310 This feature enables tracking lock contention points
1312 For more details, see Documentation/locking/lockstat.rst
1314 This also enables lock events required by "perf lock",
1316 If you want to use "perf lock", you also need to turn on
1317 CONFIG_EVENT_TRACING.
1319 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1320 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1322 config DEBUG_RT_MUTEXES
1323 bool "RT Mutex debugging, deadlock detection"
1324 depends on DEBUG_KERNEL && RT_MUTEXES
1326 This allows rt mutex semantics violations and rt mutex related
1327 deadlocks (lockups) to be detected and reported automatically.
1329 config DEBUG_SPINLOCK
1330 bool "Spinlock and rw-lock debugging: basic checks"
1331 depends on DEBUG_KERNEL
1332 select UNINLINE_SPIN_UNLOCK
1334 Say Y here and build SMP to catch missing spinlock initialization
1335 and certain other kinds of spinlock errors commonly made. This is
1336 best used in conjunction with the NMI watchdog so that spinlock
1337 deadlocks are also debuggable.
1339 config DEBUG_MUTEXES
1340 bool "Mutex debugging: basic checks"
1341 depends on DEBUG_KERNEL
1343 This feature allows mutex semantics violations to be detected and
1346 config DEBUG_WW_MUTEX_SLOWPATH
1347 bool "Wait/wound mutex debugging: Slowpath testing"
1348 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1349 select DEBUG_LOCK_ALLOC
1350 select DEBUG_SPINLOCK
1351 select DEBUG_MUTEXES
1353 This feature enables slowpath testing for w/w mutex users by
1354 injecting additional -EDEADLK wound/backoff cases. Together with
1355 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1356 will test all possible w/w mutex interface abuse with the
1357 exception of simply not acquiring all the required locks.
1358 Note that this feature can introduce significant overhead, so
1359 it really should not be enabled in a production or distro kernel,
1360 even a debug kernel. If you are a driver writer, enable it. If
1361 you are a distro, do not.
1364 bool "RW Semaphore debugging: basic checks"
1365 depends on DEBUG_KERNEL
1367 This debugging feature allows mismatched rw semaphore locks
1368 and unlocks to be detected and reported.
1370 config DEBUG_LOCK_ALLOC
1371 bool "Lock debugging: detect incorrect freeing of live locks"
1372 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1373 select DEBUG_SPINLOCK
1374 select DEBUG_MUTEXES
1375 select DEBUG_RT_MUTEXES if RT_MUTEXES
1378 This feature will check whether any held lock (spinlock, rwlock,
1379 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1380 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1381 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1382 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1383 held during task exit.
1387 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1392 config LOCKDEP_SMALL
1396 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1397 depends on LOCKDEP && !LOCKDEP_SMALL
1401 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1403 config LOCKDEP_CHAINS_BITS
1404 int "Bitsize for MAX_LOCKDEP_CHAINS"
1405 depends on LOCKDEP && !LOCKDEP_SMALL
1409 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1411 config LOCKDEP_STACK_TRACE_BITS
1412 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1413 depends on LOCKDEP && !LOCKDEP_SMALL
1417 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1419 config LOCKDEP_STACK_TRACE_HASH_BITS
1420 int "Bitsize for STACK_TRACE_HASH_SIZE"
1421 depends on LOCKDEP && !LOCKDEP_SMALL
1425 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1427 config LOCKDEP_CIRCULAR_QUEUE_BITS
1428 int "Bitsize for elements in circular_queue struct"
1433 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1435 config DEBUG_LOCKDEP
1436 bool "Lock dependency engine debugging"
1437 depends on DEBUG_KERNEL && LOCKDEP
1438 select DEBUG_IRQFLAGS
1440 If you say Y here, the lock dependency engine will do
1441 additional runtime checks to debug itself, at the price
1442 of more runtime overhead.
1444 config DEBUG_ATOMIC_SLEEP
1445 bool "Sleep inside atomic section checking"
1446 select PREEMPT_COUNT
1447 depends on DEBUG_KERNEL
1448 depends on !ARCH_NO_PREEMPT
1450 If you say Y here, various routines which may sleep will become very
1451 noisy if they are called inside atomic sections: when a spinlock is
1452 held, inside an rcu read side critical section, inside preempt disabled
1453 sections, inside an interrupt, etc...
1455 config DEBUG_LOCKING_API_SELFTESTS
1456 bool "Locking API boot-time self-tests"
1457 depends on DEBUG_KERNEL
1459 Say Y here if you want the kernel to run a short self-test during
1460 bootup. The self-test checks whether common types of locking bugs
1461 are detected by debugging mechanisms or not. (if you disable
1462 lock debugging then those bugs won't be detected of course.)
1463 The following locking APIs are covered: spinlocks, rwlocks,
1466 config LOCK_TORTURE_TEST
1467 tristate "torture tests for locking"
1468 depends on DEBUG_KERNEL
1471 This option provides a kernel module that runs torture tests
1472 on kernel locking primitives. The kernel module may be built
1473 after the fact on the running kernel to be tested, if desired.
1475 Say Y here if you want kernel locking-primitive torture tests
1476 to be built into the kernel.
1477 Say M if you want these torture tests to build as a module.
1478 Say N if you are unsure.
1480 config WW_MUTEX_SELFTEST
1481 tristate "Wait/wound mutex selftests"
1483 This option provides a kernel module that runs tests on the
1484 on the struct ww_mutex locking API.
1486 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1487 with this test harness.
1489 Say M if you want these self tests to build as a module.
1490 Say N if you are unsure.
1492 config SCF_TORTURE_TEST
1493 tristate "torture tests for smp_call_function*()"
1494 depends on DEBUG_KERNEL
1497 This option provides a kernel module that runs torture tests
1498 on the smp_call_function() family of primitives. The kernel
1499 module may be built after the fact on the running kernel to
1500 be tested, if desired.
1502 config CSD_LOCK_WAIT_DEBUG
1503 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1504 depends on DEBUG_KERNEL
1508 This option enables debug prints when CPUs are slow to respond
1509 to the smp_call_function*() IPI wrappers. These debug prints
1510 include the IPI handler function currently executing (if any)
1511 and relevant stack traces.
1513 endmenu # lock debugging
1515 config TRACE_IRQFLAGS
1516 depends on TRACE_IRQFLAGS_SUPPORT
1519 Enables hooks to interrupt enabling and disabling for
1520 either tracing or lock debugging.
1522 config TRACE_IRQFLAGS_NMI
1524 depends on TRACE_IRQFLAGS
1525 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1527 config DEBUG_IRQFLAGS
1528 bool "Debug IRQ flag manipulation"
1530 Enables checks for potentially unsafe enabling or disabling of
1531 interrupts, such as calling raw_local_irq_restore() when interrupts
1535 bool "Stack backtrace support"
1536 depends on STACKTRACE_SUPPORT
1538 This option causes the kernel to create a /proc/pid/stack for
1539 every process, showing its current stack trace.
1540 It is also used by various kernel debugging features that require
1541 stack trace generation.
1543 config WARN_ALL_UNSEEDED_RANDOM
1544 bool "Warn for all uses of unseeded randomness"
1547 Some parts of the kernel contain bugs relating to their use of
1548 cryptographically secure random numbers before it's actually possible
1549 to generate those numbers securely. This setting ensures that these
1550 flaws don't go unnoticed, by enabling a message, should this ever
1551 occur. This will allow people with obscure setups to know when things
1552 are going wrong, so that they might contact developers about fixing
1555 Unfortunately, on some models of some architectures getting
1556 a fully seeded CRNG is extremely difficult, and so this can
1557 result in dmesg getting spammed for a surprisingly long
1558 time. This is really bad from a security perspective, and
1559 so architecture maintainers really need to do what they can
1560 to get the CRNG seeded sooner after the system is booted.
1561 However, since users cannot do anything actionable to
1562 address this, by default the kernel will issue only a single
1563 warning for the first use of unseeded randomness.
1565 Say Y here if you want to receive warnings for all uses of
1566 unseeded randomness. This will be of use primarily for
1567 those developers interested in improving the security of
1568 Linux kernels running on their architecture (or
1571 config DEBUG_KOBJECT
1572 bool "kobject debugging"
1573 depends on DEBUG_KERNEL
1575 If you say Y here, some extra kobject debugging messages will be sent
1578 config DEBUG_KOBJECT_RELEASE
1579 bool "kobject release debugging"
1580 depends on DEBUG_OBJECTS_TIMERS
1582 kobjects are reference counted objects. This means that their
1583 last reference count put is not predictable, and the kobject can
1584 live on past the point at which a driver decides to drop it's
1585 initial reference to the kobject gained on allocation. An
1586 example of this would be a struct device which has just been
1589 However, some buggy drivers assume that after such an operation,
1590 the memory backing the kobject can be immediately freed. This
1591 goes completely against the principles of a refcounted object.
1593 If you say Y here, the kernel will delay the release of kobjects
1594 on the last reference count to improve the visibility of this
1595 kind of kobject release bug.
1597 config HAVE_DEBUG_BUGVERBOSE
1600 menu "Debug kernel data structures"
1603 bool "Debug linked list manipulation"
1604 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1606 Enable this to turn on extended checks in the linked-list
1612 bool "Debug priority linked list manipulation"
1613 depends on DEBUG_KERNEL
1615 Enable this to turn on extended checks in the priority-ordered
1616 linked-list (plist) walking routines. This checks the entire
1617 list multiple times during each manipulation.
1622 bool "Debug SG table operations"
1623 depends on DEBUG_KERNEL
1625 Enable this to turn on checks on scatter-gather tables. This can
1626 help find problems with drivers that do not properly initialize
1631 config DEBUG_NOTIFIERS
1632 bool "Debug notifier call chains"
1633 depends on DEBUG_KERNEL
1635 Enable this to turn on sanity checking for notifier call chains.
1636 This is most useful for kernel developers to make sure that
1637 modules properly unregister themselves from notifier chains.
1638 This is a relatively cheap check but if you care about maximum
1641 config BUG_ON_DATA_CORRUPTION
1642 bool "Trigger a BUG when data corruption is detected"
1645 Select this option if the kernel should BUG when it encounters
1646 data corruption in kernel memory structures when they get checked
1653 config DEBUG_CREDENTIALS
1654 bool "Debug credential management"
1655 depends on DEBUG_KERNEL
1657 Enable this to turn on some debug checking for credential
1658 management. The additional code keeps track of the number of
1659 pointers from task_structs to any given cred struct, and checks to
1660 see that this number never exceeds the usage count of the cred
1663 Furthermore, if SELinux is enabled, this also checks that the
1664 security pointer in the cred struct is never seen to be invalid.
1668 source "kernel/rcu/Kconfig.debug"
1670 config DEBUG_WQ_FORCE_RR_CPU
1671 bool "Force round-robin CPU selection for unbound work items"
1672 depends on DEBUG_KERNEL
1675 Workqueue used to implicitly guarantee that work items queued
1676 without explicit CPU specified are put on the local CPU. This
1677 guarantee is no longer true and while local CPU is still
1678 preferred work items may be put on foreign CPUs. Kernel
1679 parameter "workqueue.debug_force_rr_cpu" is added to force
1680 round-robin CPU selection to flush out usages which depend on the
1681 now broken guarantee. This config option enables the debug
1682 feature by default. When enabled, memory and cache locality will
1685 config DEBUG_BLOCK_EXT_DEVT
1686 bool "Force extended block device numbers and spread them"
1687 depends on DEBUG_KERNEL
1691 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1692 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1693 YOU ARE DOING. Distros, please enable this and fix whatever
1696 Conventionally, block device numbers are allocated from
1697 predetermined contiguous area. However, extended block area
1698 may introduce non-contiguous block device numbers. This
1699 option forces most block device numbers to be allocated from
1700 the extended space and spreads them to discover kernel or
1701 userland code paths which assume predetermined contiguous
1702 device number allocation.
1704 Note that turning on this debug option shuffles all the
1705 device numbers for all IDE and SCSI devices including libata
1706 ones, so root partition specified using device number
1707 directly (via rdev or root=MAJ:MIN) won't work anymore.
1708 Textual device names (root=/dev/sdXn) will continue to work.
1710 Say N if you are unsure.
1712 config CPU_HOTPLUG_STATE_CONTROL
1713 bool "Enable CPU hotplug state control"
1714 depends on DEBUG_KERNEL
1715 depends on HOTPLUG_CPU
1718 Allows to write steps between "offline" and "online" to the CPUs
1719 sysfs target file so states can be stepped granular. This is a debug
1720 option for now as the hotplug machinery cannot be stopped and
1721 restarted at arbitrary points yet.
1723 Say N if your are unsure.
1726 bool "Latency measuring infrastructure"
1727 depends on DEBUG_KERNEL
1728 depends on STACKTRACE_SUPPORT
1730 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1736 Enable this option if you want to use the LatencyTOP tool
1737 to find out which userspace is blocking on what kernel operations.
1739 source "kernel/trace/Kconfig"
1741 config PROVIDE_OHCI1394_DMA_INIT
1742 bool "Remote debugging over FireWire early on boot"
1743 depends on PCI && X86
1745 If you want to debug problems which hang or crash the kernel early
1746 on boot and the crashing machine has a FireWire port, you can use
1747 this feature to remotely access the memory of the crashed machine
1748 over FireWire. This employs remote DMA as part of the OHCI1394
1749 specification which is now the standard for FireWire controllers.
1751 With remote DMA, you can monitor the printk buffer remotely using
1752 firescope and access all memory below 4GB using fireproxy from gdb.
1753 Even controlling a kernel debugger is possible using remote DMA.
1757 If ohci1394_dma=early is used as boot parameter, it will initialize
1758 all OHCI1394 controllers which are found in the PCI config space.
1760 As all changes to the FireWire bus such as enabling and disabling
1761 devices cause a bus reset and thereby disable remote DMA for all
1762 devices, be sure to have the cable plugged and FireWire enabled on
1763 the debugging host before booting the debug target for debugging.
1765 This code (~1k) is freed after boot. By then, the firewire stack
1766 in charge of the OHCI-1394 controllers should be used instead.
1768 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1770 source "samples/Kconfig"
1772 config ARCH_HAS_DEVMEM_IS_ALLOWED
1775 config STRICT_DEVMEM
1776 bool "Filter access to /dev/mem"
1777 depends on MMU && DEVMEM
1778 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1779 default y if PPC || X86 || ARM64
1781 If this option is disabled, you allow userspace (root) access to all
1782 of memory, including kernel and userspace memory. Accidental
1783 access to this is obviously disastrous, but specific access can
1784 be used by people debugging the kernel. Note that with PAT support
1785 enabled, even in this case there are restrictions on /dev/mem
1786 use due to the cache aliasing requirements.
1788 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1789 file only allows userspace access to PCI space and the BIOS code and
1790 data regions. This is sufficient for dosemu and X and all common
1795 config IO_STRICT_DEVMEM
1796 bool "Filter I/O access to /dev/mem"
1797 depends on STRICT_DEVMEM
1799 If this option is disabled, you allow userspace (root) access to all
1800 io-memory regardless of whether a driver is actively using that
1801 range. Accidental access to this is obviously disastrous, but
1802 specific access can be used by people debugging kernel drivers.
1804 If this option is switched on, the /dev/mem file only allows
1805 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1806 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1807 if the driver using a given range cannot be disabled.
1811 menu "$(SRCARCH) Debugging"
1813 source "arch/$(SRCARCH)/Kconfig.debug"
1817 menu "Kernel Testing and Coverage"
1819 source "lib/kunit/Kconfig"
1821 config NOTIFIER_ERROR_INJECTION
1822 tristate "Notifier error injection"
1823 depends on DEBUG_KERNEL
1826 This option provides the ability to inject artificial errors to
1827 specified notifier chain callbacks. It is useful to test the error
1828 handling of notifier call chain failures.
1832 config PM_NOTIFIER_ERROR_INJECT
1833 tristate "PM notifier error injection module"
1834 depends on PM && NOTIFIER_ERROR_INJECTION
1835 default m if PM_DEBUG
1837 This option provides the ability to inject artificial errors to
1838 PM notifier chain callbacks. It is controlled through debugfs
1839 interface /sys/kernel/debug/notifier-error-inject/pm
1841 If the notifier call chain should be failed with some events
1842 notified, write the error code to "actions/<notifier event>/error".
1844 Example: Inject PM suspend error (-12 = -ENOMEM)
1846 # cd /sys/kernel/debug/notifier-error-inject/pm/
1847 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1848 # echo mem > /sys/power/state
1849 bash: echo: write error: Cannot allocate memory
1851 To compile this code as a module, choose M here: the module will
1852 be called pm-notifier-error-inject.
1856 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1857 tristate "OF reconfig notifier error injection module"
1858 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1860 This option provides the ability to inject artificial errors to
1861 OF reconfig notifier chain callbacks. It is controlled
1862 through debugfs interface under
1863 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1865 If the notifier call chain should be failed with some events
1866 notified, write the error code to "actions/<notifier event>/error".
1868 To compile this code as a module, choose M here: the module will
1869 be called of-reconfig-notifier-error-inject.
1873 config NETDEV_NOTIFIER_ERROR_INJECT
1874 tristate "Netdev notifier error injection module"
1875 depends on NET && NOTIFIER_ERROR_INJECTION
1877 This option provides the ability to inject artificial errors to
1878 netdevice notifier chain callbacks. It is controlled through debugfs
1879 interface /sys/kernel/debug/notifier-error-inject/netdev
1881 If the notifier call chain should be failed with some events
1882 notified, write the error code to "actions/<notifier event>/error".
1884 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1886 # cd /sys/kernel/debug/notifier-error-inject/netdev
1887 # echo -22 > actions/NETDEV_CHANGEMTU/error
1888 # ip link set eth0 mtu 1024
1889 RTNETLINK answers: Invalid argument
1891 To compile this code as a module, choose M here: the module will
1892 be called netdev-notifier-error-inject.
1896 config FUNCTION_ERROR_INJECTION
1898 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1900 config FAULT_INJECTION
1901 bool "Fault-injection framework"
1902 depends on DEBUG_KERNEL
1904 Provide fault-injection framework.
1905 For more details, see Documentation/fault-injection/.
1908 bool "Fault-injection capability for kmalloc"
1909 depends on FAULT_INJECTION
1910 depends on SLAB || SLUB
1912 Provide fault-injection capability for kmalloc.
1914 config FAIL_PAGE_ALLOC
1915 bool "Fault-injection capability for alloc_pages()"
1916 depends on FAULT_INJECTION
1918 Provide fault-injection capability for alloc_pages().
1920 config FAULT_INJECTION_USERCOPY
1921 bool "Fault injection capability for usercopy functions"
1922 depends on FAULT_INJECTION
1924 Provides fault-injection capability to inject failures
1925 in usercopy functions (copy_from_user(), get_user(), ...).
1927 config FAIL_MAKE_REQUEST
1928 bool "Fault-injection capability for disk IO"
1929 depends on FAULT_INJECTION && BLOCK
1931 Provide fault-injection capability for disk IO.
1933 config FAIL_IO_TIMEOUT
1934 bool "Fault-injection capability for faking disk interrupts"
1935 depends on FAULT_INJECTION && BLOCK
1937 Provide fault-injection capability on end IO handling. This
1938 will make the block layer "forget" an interrupt as configured,
1939 thus exercising the error handling.
1941 Only works with drivers that use the generic timeout handling,
1942 for others it won't do anything.
1945 bool "Fault-injection capability for futexes"
1947 depends on FAULT_INJECTION && FUTEX
1949 Provide fault-injection capability for futexes.
1951 config FAULT_INJECTION_DEBUG_FS
1952 bool "Debugfs entries for fault-injection capabilities"
1953 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1955 Enable configuration of fault-injection capabilities via debugfs.
1957 config FAIL_FUNCTION
1958 bool "Fault-injection capability for functions"
1959 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1961 Provide function-based fault-injection capability.
1962 This will allow you to override a specific function with a return
1963 with given return value. As a result, function caller will see
1964 an error value and have to handle it. This is useful to test the
1965 error handling in various subsystems.
1967 config FAIL_MMC_REQUEST
1968 bool "Fault-injection capability for MMC IO"
1969 depends on FAULT_INJECTION_DEBUG_FS && MMC
1971 Provide fault-injection capability for MMC IO.
1972 This will make the mmc core return data errors. This is
1973 useful to test the error handling in the mmc block device
1974 and to test how the mmc host driver handles retries from
1977 config FAULT_INJECTION_STACKTRACE_FILTER
1978 bool "stacktrace filter for fault-injection capabilities"
1979 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1982 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1984 Provide stacktrace filter for fault-injection capabilities
1986 config ARCH_HAS_KCOV
1989 An architecture should select this when it can successfully
1990 build and run with CONFIG_KCOV. This typically requires
1991 disabling instrumentation for some early boot code.
1993 config CC_HAS_SANCOV_TRACE_PC
1994 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1998 bool "Code coverage for fuzzing"
1999 depends on ARCH_HAS_KCOV
2000 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2002 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2004 KCOV exposes kernel code coverage information in a form suitable
2005 for coverage-guided fuzzing (randomized testing).
2007 If RANDOMIZE_BASE is enabled, PC values will not be stable across
2008 different machines and across reboots. If you need stable PC values,
2009 disable RANDOMIZE_BASE.
2011 For more details, see Documentation/dev-tools/kcov.rst.
2013 config KCOV_ENABLE_COMPARISONS
2014 bool "Enable comparison operands collection by KCOV"
2016 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2018 KCOV also exposes operands of every comparison in the instrumented
2019 code along with operand sizes and PCs of the comparison instructions.
2020 These operands can be used by fuzzing engines to improve the quality
2021 of fuzzing coverage.
2023 config KCOV_INSTRUMENT_ALL
2024 bool "Instrument all code by default"
2028 If you are doing generic system call fuzzing (like e.g. syzkaller),
2029 then you will want to instrument the whole kernel and you should
2030 say y here. If you are doing more targeted fuzzing (like e.g.
2031 filesystem fuzzing with AFL) then you will want to enable coverage
2032 for more specific subsets of files, and should say n here.
2034 config KCOV_IRQ_AREA_SIZE
2035 hex "Size of interrupt coverage collection area in words"
2039 KCOV uses preallocated per-cpu areas to collect coverage from
2040 soft interrupts. This specifies the size of those areas in the
2041 number of unsigned long words.
2043 menuconfig RUNTIME_TESTING_MENU
2044 bool "Runtime Testing"
2047 if RUNTIME_TESTING_MENU
2050 tristate "Linux Kernel Dump Test Tool Module"
2053 This module enables testing of the different dumping mechanisms by
2054 inducing system failures at predefined crash points.
2055 If you don't need it: say N
2056 Choose M here to compile this code as a module. The module will be
2059 Documentation on how to use the module can be found in
2060 Documentation/fault-injection/provoke-crashes.rst
2062 config TEST_LIST_SORT
2063 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2065 default KUNIT_ALL_TESTS
2067 Enable this to turn on 'list_sort()' function test. This test is
2068 executed only once during system boot (so affects only boot time),
2069 or at module load time.
2073 config TEST_MIN_HEAP
2074 tristate "Min heap test"
2075 depends on DEBUG_KERNEL || m
2077 Enable this to turn on min heap function tests. This test is
2078 executed only once during system boot (so affects only boot time),
2079 or at module load time.
2084 tristate "Array-based sort test"
2085 depends on DEBUG_KERNEL || m
2087 This option enables the self-test function of 'sort()' at boot,
2088 or at module load time.
2093 tristate "64bit/32bit division and modulo test"
2094 depends on DEBUG_KERNEL || m
2096 Enable this to turn on 'do_div()' function test. This test is
2097 executed only once during system boot (so affects only boot time),
2098 or at module load time.
2102 config KPROBES_SANITY_TEST
2103 bool "Kprobes sanity tests"
2104 depends on DEBUG_KERNEL
2107 This option provides for testing basic kprobes functionality on
2108 boot. Samples of kprobe and kretprobe are inserted and
2109 verified for functionality.
2111 Say N if you are unsure.
2113 config BACKTRACE_SELF_TEST
2114 tristate "Self test for the backtrace code"
2115 depends on DEBUG_KERNEL
2117 This option provides a kernel module that can be used to test
2118 the kernel stack backtrace code. This option is not useful
2119 for distributions or general kernels, but only for kernel
2120 developers working on architecture code.
2122 Note that if you want to also test saved backtraces, you will
2123 have to enable STACKTRACE as well.
2125 Say N if you are unsure.
2128 tristate "Red-Black tree test"
2129 depends on DEBUG_KERNEL
2131 A benchmark measuring the performance of the rbtree library.
2132 Also includes rbtree invariant checks.
2134 config REED_SOLOMON_TEST
2135 tristate "Reed-Solomon library test"
2136 depends on DEBUG_KERNEL || m
2138 select REED_SOLOMON_ENC16
2139 select REED_SOLOMON_DEC16
2141 This option enables the self-test function of rslib at boot,
2142 or at module load time.
2146 config INTERVAL_TREE_TEST
2147 tristate "Interval tree test"
2148 depends on DEBUG_KERNEL
2149 select INTERVAL_TREE
2151 A benchmark measuring the performance of the interval tree library
2154 tristate "Per cpu operations test"
2155 depends on m && DEBUG_KERNEL
2157 Enable this option to build test module which validates per-cpu
2162 config ATOMIC64_SELFTEST
2163 tristate "Perform an atomic64_t self-test"
2165 Enable this option to test the atomic64_t functions at boot or
2166 at module load time.
2170 config ASYNC_RAID6_TEST
2171 tristate "Self test for hardware accelerated raid6 recovery"
2172 depends on ASYNC_RAID6_RECOV
2175 This is a one-shot self test that permutes through the
2176 recovery of all the possible two disk failure scenarios for a
2177 N-disk array. Recovery is performed with the asynchronous
2178 raid6 recovery routines, and will optionally use an offload
2179 engine if one is available.
2184 tristate "Test functions located in the hexdump module at runtime"
2186 config TEST_STRING_HELPERS
2187 tristate "Test functions located in the string_helpers module at runtime"
2190 tristate "Test strscpy*() family of functions at runtime"
2193 tristate "Test kstrto*() family of functions at runtime"
2196 tristate "Test printf() family of functions at runtime"
2199 tristate "Test scanf() family of functions at runtime"
2202 tristate "Test bitmap_*() family of functions at runtime"
2204 Enable this option to test the bitmap functions at boot.
2209 tristate "Test functions located in the uuid module at runtime"
2212 tristate "Test the XArray code at runtime"
2214 config TEST_OVERFLOW
2215 tristate "Test check_*_overflow() functions at runtime"
2217 config TEST_RHASHTABLE
2218 tristate "Perform selftest on resizable hash table"
2220 Enable this option to test the rhashtable functions at boot.
2225 tristate "Perform selftest on hash functions"
2227 Enable this option to test the kernel's integer (<linux/hash.h>),
2228 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2229 hash functions on boot (or module load).
2231 This is intended to help people writing architecture-specific
2232 optimized versions. If unsure, say N.
2235 tristate "Perform selftest on IDA functions"
2238 tristate "Perform selftest on priority array manager"
2241 Enable this option to test priority array manager on boot
2246 config TEST_IRQ_TIMINGS
2247 bool "IRQ timings selftest"
2248 depends on IRQ_TIMINGS
2250 Enable this option to test the irq timings code on boot.
2255 tristate "Test module loading with 'hello world' module"
2258 This builds the "test_module" module that emits "Hello, world"
2259 on printk when loaded. It is designed to be used for basic
2260 evaluation of the module loading subsystem (for example when
2261 validating module verification). It lacks any extra dependencies,
2262 and will not normally be loaded by the system unless explicitly
2268 tristate "Test module for compilation of bitops operations"
2271 This builds the "test_bitops" module that is much like the
2272 TEST_LKM module except that it does a basic exercise of the
2273 set/clear_bit macros and get_count_order/long to make sure there are
2274 no compiler warnings from C=1 sparse checker or -Wextra
2275 compilations. It has no dependencies and doesn't run or load unless
2276 explicitly requested by name. for example: modprobe test_bitops.
2281 tristate "Test module for stress/performance analysis of vmalloc allocator"
2286 This builds the "test_vmalloc" module that should be used for
2287 stress and performance analysis. So, any new change for vmalloc
2288 subsystem can be evaluated from performance and stability point
2293 config TEST_USER_COPY
2294 tristate "Test user/kernel boundary protections"
2297 This builds the "test_user_copy" module that runs sanity checks
2298 on the copy_to/from_user infrastructure, making sure basic
2299 user/kernel boundary testing is working. If it fails to load,
2300 a regression has been detected in the user/kernel memory boundary
2306 tristate "Test BPF filter functionality"
2309 This builds the "test_bpf" module that runs various test vectors
2310 against the BPF interpreter or BPF JIT compiler depending on the
2311 current setting. This is in particular useful for BPF JIT compiler
2312 development, but also to run regression tests against changes in
2313 the interpreter code. It also enables test stubs for eBPF maps and
2314 verifier used by user space verifier testsuite.
2318 config TEST_BLACKHOLE_DEV
2319 tristate "Test blackhole netdev functionality"
2322 This builds the "test_blackhole_dev" module that validates the
2323 data path through this blackhole netdev.
2327 config FIND_BIT_BENCHMARK
2328 tristate "Test find_bit functions"
2330 This builds the "test_find_bit" module that measure find_*_bit()
2331 functions performance.
2335 config TEST_FIRMWARE
2336 tristate "Test firmware loading via userspace interface"
2337 depends on FW_LOADER
2339 This builds the "test_firmware" module that creates a userspace
2340 interface for testing firmware loading. This can be used to
2341 control the triggering of firmware loading without needing an
2342 actual firmware-using device. The contents can be rechecked by
2348 tristate "sysctl test driver"
2349 depends on PROC_SYSCTL
2351 This builds the "test_sysctl" module. This driver enables to test the
2352 proc sysctl interfaces available to drivers safely without affecting
2353 production knobs which might alter system functionality.
2357 config BITFIELD_KUNIT
2358 tristate "KUnit test bitfield functions at runtime"
2361 Enable this option to test the bitfield functions at boot.
2363 KUnit tests run during boot and output the results to the debug log
2364 in TAP format (http://testanything.org/). Only useful for kernel devs
2365 running the KUnit test harness, and not intended for inclusion into a
2368 For more information on KUnit and unit tests in general please refer
2369 to the KUnit documentation in Documentation/dev-tools/kunit/.
2373 config RESOURCE_KUNIT_TEST
2374 tristate "KUnit test for resource API"
2377 This builds the resource API unit test.
2378 Tests the logic of API provided by resource.c and ioport.h.
2379 For more information on KUnit and unit tests in general please refer
2380 to the KUnit documentation in Documentation/dev-tools/kunit/.
2384 config SYSCTL_KUNIT_TEST
2385 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2387 default KUNIT_ALL_TESTS
2389 This builds the proc sysctl unit test, which runs on boot.
2390 Tests the API contract and implementation correctness of sysctl.
2391 For more information on KUnit and unit tests in general please refer
2392 to the KUnit documentation in Documentation/dev-tools/kunit/.
2396 config LIST_KUNIT_TEST
2397 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2399 default KUNIT_ALL_TESTS
2401 This builds the linked list KUnit test suite.
2402 It tests that the API and basic functionality of the list_head type
2403 and associated macros.
2405 KUnit tests run during boot and output the results to the debug log
2406 in TAP format (https://testanything.org/). Only useful for kernel devs
2407 running the KUnit test harness, and not intended for inclusion into a
2410 For more information on KUnit and unit tests in general please refer
2411 to the KUnit documentation in Documentation/dev-tools/kunit/.
2415 config LINEAR_RANGES_TEST
2416 tristate "KUnit test for linear_ranges"
2418 select LINEAR_RANGES
2420 This builds the linear_ranges unit test, which runs on boot.
2421 Tests the linear_ranges logic correctness.
2422 For more information on KUnit and unit tests in general please refer
2423 to the KUnit documentation in Documentation/dev-tools/kunit/.
2427 config CMDLINE_KUNIT_TEST
2428 tristate "KUnit test for cmdline API"
2431 This builds the cmdline API unit test.
2432 Tests the logic of API provided by cmdline.c.
2433 For more information on KUnit and unit tests in general please refer
2434 to the KUnit documentation in Documentation/dev-tools/kunit/.
2439 tristate "KUnit test for bits.h"
2442 This builds the bits unit test.
2443 Tests the logic of macros defined in bits.h.
2444 For more information on KUnit and unit tests in general please refer
2445 to the KUnit documentation in Documentation/dev-tools/kunit/.
2449 config SLUB_KUNIT_TEST
2450 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2451 depends on SLUB_DEBUG && KUNIT
2452 default KUNIT_ALL_TESTS
2454 This builds SLUB allocator unit test.
2455 Tests SLUB cache debugging functionality.
2456 For more information on KUnit and unit tests in general please refer
2457 to the KUnit documentation in Documentation/dev-tools/kunit/.
2461 config RATIONAL_KUNIT_TEST
2462 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2465 default KUNIT_ALL_TESTS
2467 This builds the rational math unit test.
2468 For more information on KUnit and unit tests in general please refer
2469 to the KUnit documentation in Documentation/dev-tools/kunit/.
2474 tristate "udelay test driver"
2476 This builds the "udelay_test" module that helps to make sure
2477 that udelay() is working properly.
2481 config TEST_STATIC_KEYS
2482 tristate "Test static keys"
2485 Test the static key interfaces.
2490 tristate "kmod stress tester"
2492 depends on NETDEVICES && NET_CORE && INET # for TUN
2499 Test the kernel's module loading mechanism: kmod. kmod implements
2500 support to load modules using the Linux kernel's usermode helper.
2501 This test provides a series of tests against kmod.
2503 Although technically you can either build test_kmod as a module or
2504 into the kernel we disallow building it into the kernel since
2505 it stress tests request_module() and this will very likely cause
2506 some issues by taking over precious threads available from other
2507 module load requests, ultimately this could be fatal.
2511 tools/testing/selftests/kmod/kmod.sh --help
2515 config TEST_DEBUG_VIRTUAL
2516 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2517 depends on DEBUG_VIRTUAL
2519 Test the kernel's ability to detect incorrect calls to
2520 virt_to_phys() done against the non-linear part of the
2521 kernel's virtual address map.
2525 config TEST_MEMCAT_P
2526 tristate "Test memcat_p() helper function"
2528 Test the memcat_p() helper for correctly merging two
2529 pointer arrays together.
2533 config TEST_LIVEPATCH
2534 tristate "Test livepatching"
2536 depends on DYNAMIC_DEBUG
2537 depends on LIVEPATCH
2540 Test kernel livepatching features for correctness. The tests will
2541 load test modules that will be livepatched in various scenarios.
2543 To run all the livepatching tests:
2545 make -C tools/testing/selftests TARGETS=livepatch run_tests
2547 Alternatively, individual tests may be invoked:
2549 tools/testing/selftests/livepatch/test-callbacks.sh
2550 tools/testing/selftests/livepatch/test-livepatch.sh
2551 tools/testing/selftests/livepatch/test-shadow-vars.sh
2556 tristate "Perform selftest on object aggreration manager"
2560 Enable this option to test object aggregation manager on boot
2564 config TEST_STACKINIT
2565 tristate "Test level of stack variable initialization"
2567 Test if the kernel is zero-initializing stack variables and
2568 padding. Coverage is controlled by compiler flags,
2569 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2570 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2575 tristate "Test heap/page initialization"
2577 Test if the kernel is zero-initializing heap and page allocations.
2578 This can be useful to test init_on_alloc and init_on_free features.
2583 tristate "Test HMM (Heterogeneous Memory Management)"
2584 depends on TRANSPARENT_HUGEPAGE
2585 depends on DEVICE_PRIVATE
2589 This is a pseudo device driver solely for testing HMM.
2590 Say M here if you want to build the HMM test module.
2591 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2595 config TEST_FREE_PAGES
2596 tristate "Test freeing pages"
2598 Test that a memory leak does not occur due to a race between
2599 freeing a block of pages and a speculative page reference.
2600 Loading this module is safe if your kernel has the bug fixed.
2601 If the bug is not fixed, it will leak gigabytes of memory and
2602 probably OOM your system.
2605 tristate "Test floating point operations in kernel space"
2606 depends on X86 && !KCOV_INSTRUMENT_ALL
2608 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2609 which will trigger a sequence of floating point operations. This is used
2610 for self-testing floating point control register setting in
2615 config TEST_CLOCKSOURCE_WATCHDOG
2616 tristate "Test clocksource watchdog in kernel space"
2617 depends on CLOCKSOURCE_WATCHDOG
2619 Enable this option to create a kernel module that will trigger
2620 a test of the clocksource watchdog. This module may be loaded
2621 via modprobe or insmod in which case it will run upon being
2622 loaded, or it may be built in, in which case it will run
2627 endif # RUNTIME_TESTING_MENU
2629 config ARCH_USE_MEMTEST
2632 An architecture should select this when it uses early_memtest()
2633 during boot process.
2637 depends on ARCH_USE_MEMTEST
2639 This option adds a kernel parameter 'memtest', which allows memtest
2640 to be set and executed.
2641 memtest=0, mean disabled; -- default
2642 memtest=1, mean do 1 test pattern;
2644 memtest=17, mean do 17 test patterns.
2645 If you are unsure how to answer this question, answer N.
2649 config HYPERV_TESTING
2650 bool "Microsoft Hyper-V driver testing"
2652 depends on HYPERV && DEBUG_FS
2654 Select this option to enable Hyper-V vmbus testing.
2656 endmenu # "Kernel Testing and Coverage"
2658 source "Documentation/Kconfig"
2660 endmenu # Kernel hacking
projects / linux-2.6-microblaze.git / blob