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 CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
43 Default loglevel to determine what will be printed on the console.
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
49 Note: This does not affect the log level of un-prefixed printk()
50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
53 config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
58 loglevel to use when "quiet" is passed on the kernel commandline.
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
64 config MESSAGE_LOGLEVEL_DEFAULT
65 int "Default message log level (1-7)"
69 Default log level for printk statements with no specified priority.
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
75 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
79 config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
98 bool "Enable dynamic printk() support"
101 depends on (DEBUG_FS || PROC_FS)
102 select DYNAMIC_DEBUG_CORE
105 Compiles debug level messages into the kernel, which would not
106 otherwise be available at runtime. These messages can then be
107 enabled/disabled based on various levels of scope - per source file,
108 function, module, format string, and line number. This mechanism
109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
110 enlarges the kernel text size by about 2%.
112 If a source file is compiled with DEBUG flag set, any
113 pr_debug() calls in it are enabled by default, but can be
114 disabled at runtime as below. Note that DEBUG flag is
115 turned on by many CONFIG_*DEBUG* options.
119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
120 which is contained in the 'debugfs' filesystem or procfs.
121 Thus, the debugfs or procfs filesystem must first be mounted before
122 making use of this feature.
123 We refer the control file as: <debugfs>/dynamic_debug/control. This
124 file contains a list of the debug statements that can be enabled. The
125 format for each line of the file is:
127 filename:lineno [module]function flags format
129 filename : source file of the debug statement
130 lineno : line number of the debug statement
131 module : module that contains the debug statement
132 function : function that contains the debug statement
133 flags : '=p' means the line is turned 'on' for printing
134 format : the format used for the debug statement
138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
139 # filename:lineno [module]function flags format
140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
146 // enable the message at line 1603 of file svcsock.c
147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
148 <debugfs>/dynamic_debug/control
150 // enable all the messages in file svcsock.c
151 nullarbor:~ # echo -n 'file svcsock.c +p' >
152 <debugfs>/dynamic_debug/control
154 // enable all the messages in the NFS server module
155 nullarbor:~ # echo -n 'module nfsd +p' >
156 <debugfs>/dynamic_debug/control
158 // enable all 12 messages in the function svc_process()
159 nullarbor:~ # echo -n 'func svc_process +p' >
160 <debugfs>/dynamic_debug/control
162 // disable all 12 messages in the function svc_process()
163 nullarbor:~ # echo -n 'func svc_process -p' >
164 <debugfs>/dynamic_debug/control
166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
169 config DYNAMIC_DEBUG_CORE
170 bool "Enable core function of dynamic debug support"
172 depends on (DEBUG_FS || PROC_FS)
174 Enable core functional support of dynamic debug. It is useful
175 when you want to tie dynamic debug to your kernel modules with
176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
177 the case of embedded system where the kernel image size is
178 sensitive for people.
180 config SYMBOLIC_ERRNAME
181 bool "Support symbolic error names in printf"
184 If you say Y here, the kernel's printf implementation will
185 be able to print symbolic error names such as ENOSPC instead
186 of the number 28. It makes the kernel image slightly larger
187 (about 3KB), but can make the kernel logs easier to read.
189 config DEBUG_BUGVERBOSE
190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
194 Say Y here to make BUG() panics output the file name and line number
195 of the BUG call as well as the EIP and oops trace. This aids
196 debugging but costs about 70-100K of memory.
198 endmenu # "printk and dmesg options"
200 menu "Compile-time checks and compiler options"
203 bool "Compile the kernel with debug info"
204 depends on DEBUG_KERNEL && !COMPILE_TEST
206 If you say Y here the resulting kernel image will include
207 debugging info resulting in a larger kernel image.
208 This adds debug symbols to the kernel and modules (gcc -g), and
209 is needed if you intend to use kernel crashdump or binary object
210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
211 Say Y here only if you plan to debug the kernel.
215 config DEBUG_INFO_REDUCED
216 bool "Reduce debugging information"
217 depends on DEBUG_INFO
219 If you say Y here gcc is instructed to generate less debugging
220 information for structure types. This means that tools that
221 need full debugging information (like kgdb or systemtap) won't
222 be happy. But if you merely need debugging information to
223 resolve line numbers there is no loss. Advantage is that
224 build directory object sizes shrink dramatically over a full
225 DEBUG_INFO build and compile times are reduced too.
226 Only works with newer gcc versions.
228 config DEBUG_INFO_COMPRESSED
229 bool "Compressed debugging information"
230 depends on DEBUG_INFO
231 depends on $(cc-option,-gz=zlib)
232 depends on $(ld-option,--compress-debug-sections=zlib)
234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
235 5.0+, binutils 2.26+, and zlib.
237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
238 size of their debug .deb packages with this config set, due to the
239 debug info being compressed with zlib, then the object files being
240 recompressed with a different compression scheme. But this is still
241 preferable to setting $KDEB_COMPRESS to "none" which would be even
244 config DEBUG_INFO_SPLIT
245 bool "Produce split debuginfo in .dwo files"
246 depends on DEBUG_INFO
247 depends on $(cc-option,-gsplit-dwarf)
249 Generate debug info into separate .dwo files. This significantly
250 reduces the build directory size for builds with DEBUG_INFO,
251 because it stores the information only once on disk in .dwo
252 files instead of multiple times in object files and executables.
253 In addition the debug information is also compressed.
255 Requires recent gcc (4.7+) and recent gdb/binutils.
256 Any tool that packages or reads debug information would need
257 to know about the .dwo files and include them.
258 Incompatible with older versions of ccache.
260 config DEBUG_INFO_DWARF4
261 bool "Generate dwarf4 debuginfo"
262 depends on DEBUG_INFO
263 depends on $(cc-option,-gdwarf-4)
265 Generate dwarf4 debug info. This requires recent versions
266 of gcc and gdb. It makes the debug information larger.
267 But it significantly improves the success of resolving
268 variables in gdb on optimized code.
270 config DEBUG_INFO_BTF
271 bool "Generate BTF typeinfo"
272 depends on DEBUG_INFO
273 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
274 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
276 Generate deduplicated BTF type information from DWARF debug info.
277 Turning this on expects presence of pahole tool, which will convert
278 DWARF type info into equivalent deduplicated BTF type info.
281 bool "Provide GDB scripts for kernel debugging"
282 depends on DEBUG_INFO
284 This creates the required links to GDB helper scripts in the
285 build directory. If you load vmlinux into gdb, the helper
286 scripts will be automatically imported by gdb as well, and
287 additional functions are available to analyze a Linux kernel
288 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
291 config ENABLE_MUST_CHECK
292 bool "Enable __must_check logic"
295 Enable the __must_check logic in the kernel build. Disable this to
296 suppress the "warning: ignoring return value of 'foo', declared with
297 attribute warn_unused_result" messages.
300 int "Warn for stack frames larger than"
302 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
303 default 1280 if (!64BIT && PARISC)
304 default 1024 if (!64BIT && !PARISC)
305 default 2048 if 64BIT
307 Tell gcc to warn at build time for stack frames larger than this.
308 Setting this too low will cause a lot of warnings.
309 Setting it to 0 disables the warning.
311 config STRIP_ASM_SYMS
312 bool "Strip assembler-generated symbols during link"
315 Strip internal assembler-generated symbols during a link (symbols
316 that look like '.Lxxx') so they don't pollute the output of
317 get_wchan() and suchlike.
320 bool "Generate readable assembler code"
321 depends on DEBUG_KERNEL
323 Disable some compiler optimizations that tend to generate human unreadable
324 assembler output. This may make the kernel slightly slower, but it helps
325 to keep kernel developers who have to stare a lot at assembler listings
328 config HEADERS_INSTALL
329 bool "Install uapi headers to usr/include"
332 This option will install uapi headers (headers exported to user-space)
333 into the usr/include directory for use during the kernel build.
334 This is unneeded for building the kernel itself, but needed for some
335 user-space program samples. It is also needed by some features such
336 as uapi header sanity checks.
338 config DEBUG_SECTION_MISMATCH
339 bool "Enable full Section mismatch analysis"
341 The section mismatch analysis checks if there are illegal
342 references from one section to another section.
343 During linktime or runtime, some sections are dropped;
344 any use of code/data previously in these sections would
345 most likely result in an oops.
346 In the code, functions and variables are annotated with
347 __init,, etc. (see the full list in include/linux/init.h),
348 which results in the code/data being placed in specific sections.
349 The section mismatch analysis is always performed after a full
350 kernel build, and enabling this option causes the following
351 additional step to occur:
352 - Add the option -fno-inline-functions-called-once to gcc commands.
353 When inlining a function annotated with __init in a non-init
354 function, we would lose the section information and thus
355 the analysis would not catch the illegal reference.
356 This option tells gcc to inline less (but it does result in
359 config SECTION_MISMATCH_WARN_ONLY
360 bool "Make section mismatch errors non-fatal"
363 If you say N here, the build process will fail if there are any
364 section mismatch, instead of just throwing warnings.
368 config DEBUG_FORCE_FUNCTION_ALIGN_32B
369 bool "Force all function address 32B aligned" if EXPERT
371 There are cases that a commit from one domain changes the function
372 address alignment of other domains, and cause magic performance
373 bump (regression or improvement). Enable this option will help to
374 verify if the bump is caused by function alignment changes, while
375 it will slightly increase the kernel size and affect icache usage.
377 It is mainly for debug and performance tuning use.
380 # Select this config option from the architecture Kconfig, if it
381 # is preferred to always offer frame pointers as a config
382 # option on the architecture (regardless of KERNEL_DEBUG):
384 config ARCH_WANT_FRAME_POINTERS
388 bool "Compile the kernel with frame pointers"
389 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
390 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
392 If you say Y here the resulting kernel image will be slightly
393 larger and slower, but it gives very useful debugging information
394 in case of kernel bugs. (precise oopses/stacktraces/warnings)
396 config STACK_VALIDATION
397 bool "Compile-time stack metadata validation"
398 depends on HAVE_STACK_VALIDATION
401 Add compile-time checks to validate stack metadata, including frame
402 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
403 that runtime stack traces are more reliable.
405 This is also a prerequisite for generation of ORC unwind data, which
406 is needed for CONFIG_UNWINDER_ORC.
408 For more information, see
409 tools/objtool/Documentation/stack-validation.txt.
411 config VMLINUX_VALIDATION
413 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
416 config DEBUG_FORCE_WEAK_PER_CPU
417 bool "Force weak per-cpu definitions"
418 depends on DEBUG_KERNEL
420 s390 and alpha require percpu variables in modules to be
421 defined weak to work around addressing range issue which
422 puts the following two restrictions on percpu variable
425 1. percpu symbols must be unique whether static or not
426 2. percpu variables can't be defined inside a function
428 To ensure that generic code follows the above rules, this
429 option forces all percpu variables to be defined as weak.
431 endmenu # "Compiler options"
433 menu "Generic Kernel Debugging Instruments"
436 bool "Magic SysRq key"
439 If you say Y here, you will have some control over the system even
440 if the system crashes for example during kernel debugging (e.g., you
441 will be able to flush the buffer cache to disk, reboot the system
442 immediately or dump some status information). This is accomplished
443 by pressing various keys while holding SysRq (Alt+PrintScreen). It
444 also works on a serial console (on PC hardware at least), if you
445 send a BREAK and then within 5 seconds a command keypress. The
446 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
447 Don't say Y unless you really know what this hack does.
449 config MAGIC_SYSRQ_DEFAULT_ENABLE
450 hex "Enable magic SysRq key functions by default"
451 depends on MAGIC_SYSRQ
454 Specifies which SysRq key functions are enabled by default.
455 This may be set to 1 or 0 to enable or disable them all, or
456 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
458 config MAGIC_SYSRQ_SERIAL
459 bool "Enable magic SysRq key over serial"
460 depends on MAGIC_SYSRQ
463 Many embedded boards have a disconnected TTL level serial which can
464 generate some garbage that can lead to spurious false sysrq detects.
465 This option allows you to decide whether you want to enable the
468 config MAGIC_SYSRQ_SERIAL_SEQUENCE
469 string "Char sequence that enables magic SysRq over serial"
470 depends on MAGIC_SYSRQ_SERIAL
473 Specifies a sequence of characters that can follow BREAK to enable
474 SysRq on a serial console.
476 If unsure, leave an empty string and the option will not be enabled.
479 bool "Debug Filesystem"
481 debugfs is a virtual file system that kernel developers use to put
482 debugging files into. Enable this option to be able to read and
483 write to these files.
485 For detailed documentation on the debugfs API, see
486 Documentation/filesystems/.
491 prompt "Debugfs default access"
493 default DEBUG_FS_ALLOW_ALL
495 This selects the default access restrictions for debugfs.
496 It can be overridden with kernel command line option
497 debugfs=[on,no-mount,off]. The restrictions apply for API access
498 and filesystem registration.
500 config DEBUG_FS_ALLOW_ALL
503 No restrictions apply. Both API and filesystem registration
504 is on. This is the normal default operation.
506 config DEBUG_FS_DISALLOW_MOUNT
507 bool "Do not register debugfs as filesystem"
509 The API is open but filesystem is not loaded. Clients can still do
510 their work and read with debug tools that do not need
513 config DEBUG_FS_ALLOW_NONE
516 Access is off. Clients get -PERM when trying to create nodes in
517 debugfs tree and debugfs is not registered as a filesystem.
518 Client can then back-off or continue without debugfs access.
522 source "lib/Kconfig.kgdb"
523 source "lib/Kconfig.ubsan"
524 source "lib/Kconfig.kcsan"
529 bool "Kernel debugging"
531 Say Y here if you are developing drivers or trying to debug and
532 identify kernel problems.
535 bool "Miscellaneous debug code"
537 depends on DEBUG_KERNEL
539 Say Y here if you need to enable miscellaneous debug code that should
540 be under a more specific debug option but isn't.
543 menu "Memory Debugging"
545 source "mm/Kconfig.debug"
548 bool "Debug object operations"
549 depends on DEBUG_KERNEL
551 If you say Y here, additional code will be inserted into the
552 kernel to track the life time of various objects and validate
553 the operations on those objects.
555 config DEBUG_OBJECTS_SELFTEST
556 bool "Debug objects selftest"
557 depends on DEBUG_OBJECTS
559 This enables the selftest of the object debug code.
561 config DEBUG_OBJECTS_FREE
562 bool "Debug objects in freed memory"
563 depends on DEBUG_OBJECTS
565 This enables checks whether a k/v free operation frees an area
566 which contains an object which has not been deactivated
567 properly. This can make kmalloc/kfree-intensive workloads
570 config DEBUG_OBJECTS_TIMERS
571 bool "Debug timer objects"
572 depends on DEBUG_OBJECTS
574 If you say Y here, additional code will be inserted into the
575 timer routines to track the life time of timer objects and
576 validate the timer operations.
578 config DEBUG_OBJECTS_WORK
579 bool "Debug work objects"
580 depends on DEBUG_OBJECTS
582 If you say Y here, additional code will be inserted into the
583 work queue routines to track the life time of work objects and
584 validate the work operations.
586 config DEBUG_OBJECTS_RCU_HEAD
587 bool "Debug RCU callbacks objects"
588 depends on DEBUG_OBJECTS
590 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
592 config DEBUG_OBJECTS_PERCPU_COUNTER
593 bool "Debug percpu counter objects"
594 depends on DEBUG_OBJECTS
596 If you say Y here, additional code will be inserted into the
597 percpu counter routines to track the life time of percpu counter
598 objects and validate the percpu counter operations.
600 config DEBUG_OBJECTS_ENABLE_DEFAULT
601 int "debug_objects bootup default value (0-1)"
604 depends on DEBUG_OBJECTS
606 Debug objects boot parameter default value
609 bool "Debug slab memory allocations"
610 depends on DEBUG_KERNEL && SLAB
612 Say Y here to have the kernel do limited verification on memory
613 allocation as well as poisoning memory on free to catch use of freed
614 memory. This can make kmalloc/kfree-intensive workloads much slower.
617 bool "SLUB debugging on by default"
618 depends on SLUB && SLUB_DEBUG
621 Boot with debugging on by default. SLUB boots by default with
622 the runtime debug capabilities switched off. Enabling this is
623 equivalent to specifying the "slub_debug" parameter on boot.
624 There is no support for more fine grained debug control like
625 possible with slub_debug=xxx. SLUB debugging may be switched
626 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
631 bool "Enable SLUB performance statistics"
632 depends on SLUB && SYSFS
634 SLUB statistics are useful to debug SLUBs allocation behavior in
635 order find ways to optimize the allocator. This should never be
636 enabled for production use since keeping statistics slows down
637 the allocator by a few percentage points. The slabinfo command
638 supports the determination of the most active slabs to figure
639 out which slabs are relevant to a particular load.
640 Try running: slabinfo -DA
642 config HAVE_DEBUG_KMEMLEAK
645 config DEBUG_KMEMLEAK
646 bool "Kernel memory leak detector"
647 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
649 select STACKTRACE if STACKTRACE_SUPPORT
653 Say Y here if you want to enable the memory leak
654 detector. The memory allocation/freeing is traced in a way
655 similar to the Boehm's conservative garbage collector, the
656 difference being that the orphan objects are not freed but
657 only shown in /sys/kernel/debug/kmemleak. Enabling this
658 feature will introduce an overhead to memory
659 allocations. See Documentation/dev-tools/kmemleak.rst for more
662 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
663 of finding leaks due to the slab objects poisoning.
665 In order to access the kmemleak file, debugfs needs to be
666 mounted (usually at /sys/kernel/debug).
668 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
669 int "Kmemleak memory pool size"
670 depends on DEBUG_KMEMLEAK
674 Kmemleak must track all the memory allocations to avoid
675 reporting false positives. Since memory may be allocated or
676 freed before kmemleak is fully initialised, use a static pool
677 of metadata objects to track such callbacks. After kmemleak is
678 fully initialised, this memory pool acts as an emergency one
679 if slab allocations fail.
681 config DEBUG_KMEMLEAK_TEST
682 tristate "Simple test for the kernel memory leak detector"
683 depends on DEBUG_KMEMLEAK && m
685 This option enables a module that explicitly leaks memory.
689 config DEBUG_KMEMLEAK_DEFAULT_OFF
690 bool "Default kmemleak to off"
691 depends on DEBUG_KMEMLEAK
693 Say Y here to disable kmemleak by default. It can then be enabled
694 on the command line via kmemleak=on.
696 config DEBUG_KMEMLEAK_AUTO_SCAN
697 bool "Enable kmemleak auto scan thread on boot up"
699 depends on DEBUG_KMEMLEAK
701 Depending on the cpu, kmemleak scan may be cpu intensive and can
702 stall user tasks at times. This option enables/disables automatic
703 kmemleak scan at boot up.
705 Say N here to disable kmemleak auto scan thread to stop automatic
706 scanning. Disabling this option disables automatic reporting of
711 config DEBUG_STACK_USAGE
712 bool "Stack utilization instrumentation"
713 depends on DEBUG_KERNEL && !IA64
715 Enables the display of the minimum amount of free stack which each
716 task has ever had available in the sysrq-T and sysrq-P debug output.
718 This option will slow down process creation somewhat.
720 config SCHED_STACK_END_CHECK
721 bool "Detect stack corruption on calls to schedule()"
722 depends on DEBUG_KERNEL
725 This option checks for a stack overrun on calls to schedule().
726 If the stack end location is found to be over written always panic as
727 the content of the corrupted region can no longer be trusted.
728 This is to ensure no erroneous behaviour occurs which could result in
729 data corruption or a sporadic crash at a later stage once the region
730 is examined. The runtime overhead introduced is minimal.
732 config ARCH_HAS_DEBUG_VM_PGTABLE
735 An architecture should select this when it can successfully
736 build and run DEBUG_VM_PGTABLE.
740 depends on DEBUG_KERNEL
742 Enable this to turn on extended checks in the virtual-memory system
743 that may impact performance.
747 config DEBUG_VM_VMACACHE
748 bool "Debug VMA caching"
751 Enable this to turn on VMA caching debug information. Doing so
752 can cause significant overhead, so only enable it in non-production
758 bool "Debug VM red-black trees"
761 Enable VM red-black tree debugging information and extra validations.
765 config DEBUG_VM_PGFLAGS
766 bool "Debug page-flags operations"
769 Enables extra validation on page flags operations.
773 config DEBUG_VM_PGTABLE
774 bool "Debug arch page table for semantics compliance"
776 depends on ARCH_HAS_DEBUG_VM_PGTABLE
777 default y if DEBUG_VM
779 This option provides a debug method which can be used to test
780 architecture page table helper functions on various platforms in
781 verifying if they comply with expected generic MM semantics. This
782 will help architecture code in making sure that any changes or
783 new additions of these helpers still conform to expected
784 semantics of the generic MM. Platforms will have to opt in for
785 this through ARCH_HAS_DEBUG_VM_PGTABLE.
789 config ARCH_HAS_DEBUG_VIRTUAL
793 bool "Debug VM translations"
794 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
796 Enable some costly sanity checks in virtual to page code. This can
797 catch mistakes with virt_to_page() and friends.
801 config DEBUG_NOMMU_REGIONS
802 bool "Debug the global anon/private NOMMU mapping region tree"
803 depends on DEBUG_KERNEL && !MMU
805 This option causes the global tree of anonymous and private mapping
806 regions to be regularly checked for invalid topology.
808 config DEBUG_MEMORY_INIT
809 bool "Debug memory initialisation" if EXPERT
812 Enable this for additional checks during memory initialisation.
813 The sanity checks verify aspects of the VM such as the memory model
814 and other information provided by the architecture. Verbose
815 information will be printed at KERN_DEBUG loglevel depending
816 on the mminit_loglevel= command-line option.
820 config MEMORY_NOTIFIER_ERROR_INJECT
821 tristate "Memory hotplug notifier error injection module"
822 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
824 This option provides the ability to inject artificial errors to
825 memory hotplug notifier chain callbacks. It is controlled through
826 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
828 If the notifier call chain should be failed with some events
829 notified, write the error code to "actions/<notifier event>/error".
831 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
833 # cd /sys/kernel/debug/notifier-error-inject/memory
834 # echo -12 > actions/MEM_GOING_OFFLINE/error
835 # echo offline > /sys/devices/system/memory/memoryXXX/state
836 bash: echo: write error: Cannot allocate memory
838 To compile this code as a module, choose M here: the module will
839 be called memory-notifier-error-inject.
843 config DEBUG_PER_CPU_MAPS
844 bool "Debug access to per_cpu maps"
845 depends on DEBUG_KERNEL
848 Say Y to verify that the per_cpu map being accessed has
849 been set up. This adds a fair amount of code to kernel memory
850 and decreases performance.
855 bool "Highmem debugging"
856 depends on DEBUG_KERNEL && HIGHMEM
858 This option enables additional error checking for high memory
859 systems. Disable for production systems.
861 config HAVE_DEBUG_STACKOVERFLOW
864 config DEBUG_STACKOVERFLOW
865 bool "Check for stack overflows"
866 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
868 Say Y here if you want to check for overflows of kernel, IRQ
869 and exception stacks (if your architecture uses them). This
870 option will show detailed messages if free stack space drops
871 below a certain limit.
873 These kinds of bugs usually occur when call-chains in the
874 kernel get too deep, especially when interrupts are
877 Use this in cases where you see apparently random memory
878 corruption, especially if it appears in 'struct thread_info'
880 If in doubt, say "N".
882 source "lib/Kconfig.kasan"
884 endmenu # "Memory Debugging"
887 bool "Debug shared IRQ handlers"
888 depends on DEBUG_KERNEL
890 Enable this to generate a spurious interrupt just before a shared
891 interrupt handler is deregistered (generating one when registering
892 is currently disabled). Drivers need to handle this correctly. Some
893 don't and need to be caught.
895 menu "Debug Oops, Lockups and Hangs"
900 Say Y here to enable the kernel to panic when it oopses. This
901 has the same effect as setting oops=panic on the kernel command
904 This feature is useful to ensure that the kernel does not do
905 anything erroneous after an oops which could result in data
906 corruption or other issues.
910 config PANIC_ON_OOPS_VALUE
913 default 0 if !PANIC_ON_OOPS
914 default 1 if PANIC_ON_OOPS
920 Set the timeout value (in seconds) until a reboot occurs when
921 the kernel panics. If n = 0, then we wait forever. A timeout
922 value n > 0 will wait n seconds before rebooting, while a timeout
923 value n < 0 will reboot immediately.
925 config LOCKUP_DETECTOR
928 config SOFTLOCKUP_DETECTOR
929 bool "Detect Soft Lockups"
930 depends on DEBUG_KERNEL && !S390
931 select LOCKUP_DETECTOR
933 Say Y here to enable the kernel to act as a watchdog to detect
936 Softlockups are bugs that cause the kernel to loop in kernel
937 mode for more than 20 seconds, without giving other tasks a
938 chance to run. The current stack trace is displayed upon
939 detection and the system will stay locked up.
941 config BOOTPARAM_SOFTLOCKUP_PANIC
942 bool "Panic (Reboot) On Soft Lockups"
943 depends on SOFTLOCKUP_DETECTOR
945 Say Y here to enable the kernel to panic on "soft lockups",
946 which are bugs that cause the kernel to loop in kernel
947 mode for more than 20 seconds (configurable using the watchdog_thresh
948 sysctl), without giving other tasks a chance to run.
950 The panic can be used in combination with panic_timeout,
951 to cause the system to reboot automatically after a
952 lockup has been detected. This feature is useful for
953 high-availability systems that have uptime guarantees and
954 where a lockup must be resolved ASAP.
958 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
960 depends on SOFTLOCKUP_DETECTOR
962 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
963 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
965 config HARDLOCKUP_DETECTOR_PERF
967 select SOFTLOCKUP_DETECTOR
970 # Enables a timestamp based low pass filter to compensate for perf based
971 # hard lockup detection which runs too fast due to turbo modes.
973 config HARDLOCKUP_CHECK_TIMESTAMP
977 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
978 # lockup detector rather than the perf based detector.
980 config HARDLOCKUP_DETECTOR
981 bool "Detect Hard Lockups"
982 depends on DEBUG_KERNEL && !S390
983 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
984 select LOCKUP_DETECTOR
985 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
986 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
988 Say Y here to enable the kernel to act as a watchdog to detect
991 Hardlockups are bugs that cause the CPU to loop in kernel mode
992 for more than 10 seconds, without letting other interrupts have a
993 chance to run. The current stack trace is displayed upon detection
994 and the system will stay locked up.
996 config BOOTPARAM_HARDLOCKUP_PANIC
997 bool "Panic (Reboot) On Hard Lockups"
998 depends on HARDLOCKUP_DETECTOR
1000 Say Y here to enable the kernel to panic on "hard lockups",
1001 which are bugs that cause the kernel to loop in kernel
1002 mode with interrupts disabled for more than 10 seconds (configurable
1003 using the watchdog_thresh sysctl).
1007 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1009 depends on HARDLOCKUP_DETECTOR
1011 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1012 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1014 config DETECT_HUNG_TASK
1015 bool "Detect Hung Tasks"
1016 depends on DEBUG_KERNEL
1017 default SOFTLOCKUP_DETECTOR
1019 Say Y here to enable the kernel to detect "hung tasks",
1020 which are bugs that cause the task to be stuck in
1021 uninterruptible "D" state indefinitely.
1023 When a hung task is detected, the kernel will print the
1024 current stack trace (which you should report), but the
1025 task will stay in uninterruptible state. If lockdep is
1026 enabled then all held locks will also be reported. This
1027 feature has negligible overhead.
1029 config DEFAULT_HUNG_TASK_TIMEOUT
1030 int "Default timeout for hung task detection (in seconds)"
1031 depends on DETECT_HUNG_TASK
1034 This option controls the default timeout (in seconds) used
1035 to determine when a task has become non-responsive and should
1038 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1039 sysctl or by writing a value to
1040 /proc/sys/kernel/hung_task_timeout_secs.
1042 A timeout of 0 disables the check. The default is two minutes.
1043 Keeping the default should be fine in most cases.
1045 config BOOTPARAM_HUNG_TASK_PANIC
1046 bool "Panic (Reboot) On Hung Tasks"
1047 depends on DETECT_HUNG_TASK
1049 Say Y here to enable the kernel to panic on "hung tasks",
1050 which are bugs that cause the kernel to leave a task stuck
1051 in uninterruptible "D" state.
1053 The panic can be used in combination with panic_timeout,
1054 to cause the system to reboot automatically after a
1055 hung task has been detected. This feature is useful for
1056 high-availability systems that have uptime guarantees and
1057 where a hung tasks must be resolved ASAP.
1061 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1063 depends on DETECT_HUNG_TASK
1065 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1066 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1069 bool "Detect Workqueue Stalls"
1070 depends on DEBUG_KERNEL
1072 Say Y here to enable stall detection on workqueues. If a
1073 worker pool doesn't make forward progress on a pending work
1074 item for over a given amount of time, 30s by default, a
1075 warning message is printed along with dump of workqueue
1076 state. This can be configured through kernel parameter
1077 "workqueue.watchdog_thresh" and its sysfs counterpart.
1080 tristate "Test module to generate lockups"
1083 This builds the "test_lockup" module that helps to make sure
1084 that watchdogs and lockup detectors are working properly.
1086 Depending on module parameters it could emulate soft or hard
1087 lockup, "hung task", or locking arbitrary lock for a long time.
1088 Also it could generate series of lockups with cooling-down periods.
1092 endmenu # "Debug lockups and hangs"
1094 menu "Scheduler Debugging"
1097 bool "Collect scheduler debugging info"
1098 depends on DEBUG_KERNEL && PROC_FS
1101 If you say Y here, the /proc/sched_debug file will be provided
1102 that can help debug the scheduler. The runtime overhead of this
1110 bool "Collect scheduler statistics"
1111 depends on DEBUG_KERNEL && PROC_FS
1114 If you say Y here, additional code will be inserted into the
1115 scheduler and related routines to collect statistics about
1116 scheduler behavior and provide them in /proc/schedstat. These
1117 stats may be useful for both tuning and debugging the scheduler
1118 If you aren't debugging the scheduler or trying to tune a specific
1119 application, you can say N to avoid the very slight overhead
1124 config DEBUG_TIMEKEEPING
1125 bool "Enable extra timekeeping sanity checking"
1127 This option will enable additional timekeeping sanity checks
1128 which may be helpful when diagnosing issues where timekeeping
1129 problems are suspected.
1131 This may include checks in the timekeeping hotpaths, so this
1132 option may have a (very small) performance impact to some
1137 config DEBUG_PREEMPT
1138 bool "Debug preemptible kernel"
1139 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1142 If you say Y here then the kernel will use a debug variant of the
1143 commonly used smp_processor_id() function and will print warnings
1144 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1145 will detect preemption count underflows.
1147 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1149 config LOCK_DEBUGGING_SUPPORT
1151 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1154 config PROVE_LOCKING
1155 bool "Lock debugging: prove locking correctness"
1156 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1158 select DEBUG_SPINLOCK
1159 select DEBUG_MUTEXES
1160 select DEBUG_RT_MUTEXES if RT_MUTEXES
1162 select DEBUG_WW_MUTEX_SLOWPATH
1163 select DEBUG_LOCK_ALLOC
1164 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1165 select TRACE_IRQFLAGS
1168 This feature enables the kernel to prove that all locking
1169 that occurs in the kernel runtime is mathematically
1170 correct: that under no circumstance could an arbitrary (and
1171 not yet triggered) combination of observed locking
1172 sequences (on an arbitrary number of CPUs, running an
1173 arbitrary number of tasks and interrupt contexts) cause a
1176 In short, this feature enables the kernel to report locking
1177 related deadlocks before they actually occur.
1179 The proof does not depend on how hard and complex a
1180 deadlock scenario would be to trigger: how many
1181 participant CPUs, tasks and irq-contexts would be needed
1182 for it to trigger. The proof also does not depend on
1183 timing: if a race and a resulting deadlock is possible
1184 theoretically (no matter how unlikely the race scenario
1185 is), it will be proven so and will immediately be
1186 reported by the kernel (once the event is observed that
1187 makes the deadlock theoretically possible).
1189 If a deadlock is impossible (i.e. the locking rules, as
1190 observed by the kernel, are mathematically correct), the
1191 kernel reports nothing.
1193 NOTE: this feature can also be enabled for rwlocks, mutexes
1194 and rwsems - in which case all dependencies between these
1195 different locking variants are observed and mapped too, and
1196 the proof of observed correctness is also maintained for an
1197 arbitrary combination of these separate locking variants.
1199 For more details, see Documentation/locking/lockdep-design.rst.
1201 config PROVE_RAW_LOCK_NESTING
1202 bool "Enable raw_spinlock - spinlock nesting checks"
1203 depends on PROVE_LOCKING
1206 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1207 that the lock nesting rules for PREEMPT_RT enabled kernels are
1210 NOTE: There are known nesting problems. So if you enable this
1211 option expect lockdep splats until these problems have been fully
1212 addressed which is work in progress. This config switch allows to
1213 identify and analyze these problems. It will be removed and the
1214 check permanentely enabled once the main issues have been fixed.
1216 If unsure, select N.
1219 bool "Lock usage statistics"
1220 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1222 select DEBUG_SPINLOCK
1223 select DEBUG_MUTEXES
1224 select DEBUG_RT_MUTEXES if RT_MUTEXES
1225 select DEBUG_LOCK_ALLOC
1228 This feature enables tracking lock contention points
1230 For more details, see Documentation/locking/lockstat.rst
1232 This also enables lock events required by "perf lock",
1234 If you want to use "perf lock", you also need to turn on
1235 CONFIG_EVENT_TRACING.
1237 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1238 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1240 config DEBUG_RT_MUTEXES
1241 bool "RT Mutex debugging, deadlock detection"
1242 depends on DEBUG_KERNEL && RT_MUTEXES
1244 This allows rt mutex semantics violations and rt mutex related
1245 deadlocks (lockups) to be detected and reported automatically.
1247 config DEBUG_SPINLOCK
1248 bool "Spinlock and rw-lock debugging: basic checks"
1249 depends on DEBUG_KERNEL
1250 select UNINLINE_SPIN_UNLOCK
1252 Say Y here and build SMP to catch missing spinlock initialization
1253 and certain other kinds of spinlock errors commonly made. This is
1254 best used in conjunction with the NMI watchdog so that spinlock
1255 deadlocks are also debuggable.
1257 config DEBUG_MUTEXES
1258 bool "Mutex debugging: basic checks"
1259 depends on DEBUG_KERNEL
1261 This feature allows mutex semantics violations to be detected and
1264 config DEBUG_WW_MUTEX_SLOWPATH
1265 bool "Wait/wound mutex debugging: Slowpath testing"
1266 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1267 select DEBUG_LOCK_ALLOC
1268 select DEBUG_SPINLOCK
1269 select DEBUG_MUTEXES
1271 This feature enables slowpath testing for w/w mutex users by
1272 injecting additional -EDEADLK wound/backoff cases. Together with
1273 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1274 will test all possible w/w mutex interface abuse with the
1275 exception of simply not acquiring all the required locks.
1276 Note that this feature can introduce significant overhead, so
1277 it really should not be enabled in a production or distro kernel,
1278 even a debug kernel. If you are a driver writer, enable it. If
1279 you are a distro, do not.
1282 bool "RW Semaphore debugging: basic checks"
1283 depends on DEBUG_KERNEL
1285 This debugging feature allows mismatched rw semaphore locks
1286 and unlocks to be detected and reported.
1288 config DEBUG_LOCK_ALLOC
1289 bool "Lock debugging: detect incorrect freeing of live locks"
1290 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1291 select DEBUG_SPINLOCK
1292 select DEBUG_MUTEXES
1293 select DEBUG_RT_MUTEXES if RT_MUTEXES
1296 This feature will check whether any held lock (spinlock, rwlock,
1297 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1298 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1299 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1300 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1301 held during task exit.
1305 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1307 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1311 config LOCKDEP_SMALL
1314 config DEBUG_LOCKDEP
1315 bool "Lock dependency engine debugging"
1316 depends on DEBUG_KERNEL && LOCKDEP
1318 If you say Y here, the lock dependency engine will do
1319 additional runtime checks to debug itself, at the price
1320 of more runtime overhead.
1322 config DEBUG_ATOMIC_SLEEP
1323 bool "Sleep inside atomic section checking"
1324 select PREEMPT_COUNT
1325 depends on DEBUG_KERNEL
1326 depends on !ARCH_NO_PREEMPT
1328 If you say Y here, various routines which may sleep will become very
1329 noisy if they are called inside atomic sections: when a spinlock is
1330 held, inside an rcu read side critical section, inside preempt disabled
1331 sections, inside an interrupt, etc...
1333 config DEBUG_LOCKING_API_SELFTESTS
1334 bool "Locking API boot-time self-tests"
1335 depends on DEBUG_KERNEL
1337 Say Y here if you want the kernel to run a short self-test during
1338 bootup. The self-test checks whether common types of locking bugs
1339 are detected by debugging mechanisms or not. (if you disable
1340 lock debugging then those bugs wont be detected of course.)
1341 The following locking APIs are covered: spinlocks, rwlocks,
1344 config LOCK_TORTURE_TEST
1345 tristate "torture tests for locking"
1346 depends on DEBUG_KERNEL
1349 This option provides a kernel module that runs torture tests
1350 on kernel locking primitives. The kernel module may be built
1351 after the fact on the running kernel to be tested, if desired.
1353 Say Y here if you want kernel locking-primitive torture tests
1354 to be built into the kernel.
1355 Say M if you want these torture tests to build as a module.
1356 Say N if you are unsure.
1358 config WW_MUTEX_SELFTEST
1359 tristate "Wait/wound mutex selftests"
1361 This option provides a kernel module that runs tests on the
1362 on the struct ww_mutex locking API.
1364 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1365 with this test harness.
1367 Say M if you want these self tests to build as a module.
1368 Say N if you are unsure.
1370 config SCF_TORTURE_TEST
1371 tristate "torture tests for smp_call_function*()"
1372 depends on DEBUG_KERNEL
1375 This option provides a kernel module that runs torture tests
1376 on the smp_call_function() family of primitives. The kernel
1377 module may be built after the fact on the running kernel to
1378 be tested, if desired.
1380 config CSD_LOCK_WAIT_DEBUG
1381 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1382 depends on DEBUG_KERNEL
1386 This option enables debug prints when CPUs are slow to respond
1387 to the smp_call_function*() IPI wrappers. These debug prints
1388 include the IPI handler function currently executing (if any)
1389 and relevant stack traces.
1391 endmenu # lock debugging
1393 config TRACE_IRQFLAGS
1394 depends on TRACE_IRQFLAGS_SUPPORT
1397 Enables hooks to interrupt enabling and disabling for
1398 either tracing or lock debugging.
1400 config TRACE_IRQFLAGS_NMI
1402 depends on TRACE_IRQFLAGS
1403 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1406 bool "Stack backtrace support"
1407 depends on STACKTRACE_SUPPORT
1409 This option causes the kernel to create a /proc/pid/stack for
1410 every process, showing its current stack trace.
1411 It is also used by various kernel debugging features that require
1412 stack trace generation.
1414 config WARN_ALL_UNSEEDED_RANDOM
1415 bool "Warn for all uses of unseeded randomness"
1418 Some parts of the kernel contain bugs relating to their use of
1419 cryptographically secure random numbers before it's actually possible
1420 to generate those numbers securely. This setting ensures that these
1421 flaws don't go unnoticed, by enabling a message, should this ever
1422 occur. This will allow people with obscure setups to know when things
1423 are going wrong, so that they might contact developers about fixing
1426 Unfortunately, on some models of some architectures getting
1427 a fully seeded CRNG is extremely difficult, and so this can
1428 result in dmesg getting spammed for a surprisingly long
1429 time. This is really bad from a security perspective, and
1430 so architecture maintainers really need to do what they can
1431 to get the CRNG seeded sooner after the system is booted.
1432 However, since users cannot do anything actionable to
1433 address this, by default the kernel will issue only a single
1434 warning for the first use of unseeded randomness.
1436 Say Y here if you want to receive warnings for all uses of
1437 unseeded randomness. This will be of use primarily for
1438 those developers interested in improving the security of
1439 Linux kernels running on their architecture (or
1442 config DEBUG_KOBJECT
1443 bool "kobject debugging"
1444 depends on DEBUG_KERNEL
1446 If you say Y here, some extra kobject debugging messages will be sent
1449 config DEBUG_KOBJECT_RELEASE
1450 bool "kobject release debugging"
1451 depends on DEBUG_OBJECTS_TIMERS
1453 kobjects are reference counted objects. This means that their
1454 last reference count put is not predictable, and the kobject can
1455 live on past the point at which a driver decides to drop it's
1456 initial reference to the kobject gained on allocation. An
1457 example of this would be a struct device which has just been
1460 However, some buggy drivers assume that after such an operation,
1461 the memory backing the kobject can be immediately freed. This
1462 goes completely against the principles of a refcounted object.
1464 If you say Y here, the kernel will delay the release of kobjects
1465 on the last reference count to improve the visibility of this
1466 kind of kobject release bug.
1468 config HAVE_DEBUG_BUGVERBOSE
1471 menu "Debug kernel data structures"
1474 bool "Debug linked list manipulation"
1475 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1477 Enable this to turn on extended checks in the linked-list
1483 bool "Debug priority linked list manipulation"
1484 depends on DEBUG_KERNEL
1486 Enable this to turn on extended checks in the priority-ordered
1487 linked-list (plist) walking routines. This checks the entire
1488 list multiple times during each manipulation.
1493 bool "Debug SG table operations"
1494 depends on DEBUG_KERNEL
1496 Enable this to turn on checks on scatter-gather tables. This can
1497 help find problems with drivers that do not properly initialize
1502 config DEBUG_NOTIFIERS
1503 bool "Debug notifier call chains"
1504 depends on DEBUG_KERNEL
1506 Enable this to turn on sanity checking for notifier call chains.
1507 This is most useful for kernel developers to make sure that
1508 modules properly unregister themselves from notifier chains.
1509 This is a relatively cheap check but if you care about maximum
1512 config BUG_ON_DATA_CORRUPTION
1513 bool "Trigger a BUG when data corruption is detected"
1516 Select this option if the kernel should BUG when it encounters
1517 data corruption in kernel memory structures when they get checked
1524 config DEBUG_CREDENTIALS
1525 bool "Debug credential management"
1526 depends on DEBUG_KERNEL
1528 Enable this to turn on some debug checking for credential
1529 management. The additional code keeps track of the number of
1530 pointers from task_structs to any given cred struct, and checks to
1531 see that this number never exceeds the usage count of the cred
1534 Furthermore, if SELinux is enabled, this also checks that the
1535 security pointer in the cred struct is never seen to be invalid.
1539 source "kernel/rcu/Kconfig.debug"
1541 config DEBUG_WQ_FORCE_RR_CPU
1542 bool "Force round-robin CPU selection for unbound work items"
1543 depends on DEBUG_KERNEL
1546 Workqueue used to implicitly guarantee that work items queued
1547 without explicit CPU specified are put on the local CPU. This
1548 guarantee is no longer true and while local CPU is still
1549 preferred work items may be put on foreign CPUs. Kernel
1550 parameter "workqueue.debug_force_rr_cpu" is added to force
1551 round-robin CPU selection to flush out usages which depend on the
1552 now broken guarantee. This config option enables the debug
1553 feature by default. When enabled, memory and cache locality will
1556 config DEBUG_BLOCK_EXT_DEVT
1557 bool "Force extended block device numbers and spread them"
1558 depends on DEBUG_KERNEL
1562 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1563 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1564 YOU ARE DOING. Distros, please enable this and fix whatever
1567 Conventionally, block device numbers are allocated from
1568 predetermined contiguous area. However, extended block area
1569 may introduce non-contiguous block device numbers. This
1570 option forces most block device numbers to be allocated from
1571 the extended space and spreads them to discover kernel or
1572 userland code paths which assume predetermined contiguous
1573 device number allocation.
1575 Note that turning on this debug option shuffles all the
1576 device numbers for all IDE and SCSI devices including libata
1577 ones, so root partition specified using device number
1578 directly (via rdev or root=MAJ:MIN) won't work anymore.
1579 Textual device names (root=/dev/sdXn) will continue to work.
1581 Say N if you are unsure.
1583 config CPU_HOTPLUG_STATE_CONTROL
1584 bool "Enable CPU hotplug state control"
1585 depends on DEBUG_KERNEL
1586 depends on HOTPLUG_CPU
1589 Allows to write steps between "offline" and "online" to the CPUs
1590 sysfs target file so states can be stepped granular. This is a debug
1591 option for now as the hotplug machinery cannot be stopped and
1592 restarted at arbitrary points yet.
1594 Say N if your are unsure.
1597 bool "Latency measuring infrastructure"
1598 depends on DEBUG_KERNEL
1599 depends on STACKTRACE_SUPPORT
1601 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1608 Enable this option if you want to use the LatencyTOP tool
1609 to find out which userspace is blocking on what kernel operations.
1611 source "kernel/trace/Kconfig"
1613 config PROVIDE_OHCI1394_DMA_INIT
1614 bool "Remote debugging over FireWire early on boot"
1615 depends on PCI && X86
1617 If you want to debug problems which hang or crash the kernel early
1618 on boot and the crashing machine has a FireWire port, you can use
1619 this feature to remotely access the memory of the crashed machine
1620 over FireWire. This employs remote DMA as part of the OHCI1394
1621 specification which is now the standard for FireWire controllers.
1623 With remote DMA, you can monitor the printk buffer remotely using
1624 firescope and access all memory below 4GB using fireproxy from gdb.
1625 Even controlling a kernel debugger is possible using remote DMA.
1629 If ohci1394_dma=early is used as boot parameter, it will initialize
1630 all OHCI1394 controllers which are found in the PCI config space.
1632 As all changes to the FireWire bus such as enabling and disabling
1633 devices cause a bus reset and thereby disable remote DMA for all
1634 devices, be sure to have the cable plugged and FireWire enabled on
1635 the debugging host before booting the debug target for debugging.
1637 This code (~1k) is freed after boot. By then, the firewire stack
1638 in charge of the OHCI-1394 controllers should be used instead.
1640 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1642 source "samples/Kconfig"
1644 config ARCH_HAS_DEVMEM_IS_ALLOWED
1647 config STRICT_DEVMEM
1648 bool "Filter access to /dev/mem"
1649 depends on MMU && DEVMEM
1650 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1651 default y if PPC || X86 || ARM64
1653 If this option is disabled, you allow userspace (root) access to all
1654 of memory, including kernel and userspace memory. Accidental
1655 access to this is obviously disastrous, but specific access can
1656 be used by people debugging the kernel. Note that with PAT support
1657 enabled, even in this case there are restrictions on /dev/mem
1658 use due to the cache aliasing requirements.
1660 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1661 file only allows userspace access to PCI space and the BIOS code and
1662 data regions. This is sufficient for dosemu and X and all common
1667 config IO_STRICT_DEVMEM
1668 bool "Filter I/O access to /dev/mem"
1669 depends on STRICT_DEVMEM
1671 If this option is disabled, you allow userspace (root) access to all
1672 io-memory regardless of whether a driver is actively using that
1673 range. Accidental access to this is obviously disastrous, but
1674 specific access can be used by people debugging kernel drivers.
1676 If this option is switched on, the /dev/mem file only allows
1677 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1678 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1679 if the driver using a given range cannot be disabled.
1683 menu "$(SRCARCH) Debugging"
1685 source "arch/$(SRCARCH)/Kconfig.debug"
1689 menu "Kernel Testing and Coverage"
1691 source "lib/kunit/Kconfig"
1693 config NOTIFIER_ERROR_INJECTION
1694 tristate "Notifier error injection"
1695 depends on DEBUG_KERNEL
1698 This option provides the ability to inject artificial errors to
1699 specified notifier chain callbacks. It is useful to test the error
1700 handling of notifier call chain failures.
1704 config PM_NOTIFIER_ERROR_INJECT
1705 tristate "PM notifier error injection module"
1706 depends on PM && NOTIFIER_ERROR_INJECTION
1707 default m if PM_DEBUG
1709 This option provides the ability to inject artificial errors to
1710 PM notifier chain callbacks. It is controlled through debugfs
1711 interface /sys/kernel/debug/notifier-error-inject/pm
1713 If the notifier call chain should be failed with some events
1714 notified, write the error code to "actions/<notifier event>/error".
1716 Example: Inject PM suspend error (-12 = -ENOMEM)
1718 # cd /sys/kernel/debug/notifier-error-inject/pm/
1719 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1720 # echo mem > /sys/power/state
1721 bash: echo: write error: Cannot allocate memory
1723 To compile this code as a module, choose M here: the module will
1724 be called pm-notifier-error-inject.
1728 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1729 tristate "OF reconfig notifier error injection module"
1730 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1732 This option provides the ability to inject artificial errors to
1733 OF reconfig notifier chain callbacks. It is controlled
1734 through debugfs interface under
1735 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1737 If the notifier call chain should be failed with some events
1738 notified, write the error code to "actions/<notifier event>/error".
1740 To compile this code as a module, choose M here: the module will
1741 be called of-reconfig-notifier-error-inject.
1745 config NETDEV_NOTIFIER_ERROR_INJECT
1746 tristate "Netdev notifier error injection module"
1747 depends on NET && NOTIFIER_ERROR_INJECTION
1749 This option provides the ability to inject artificial errors to
1750 netdevice notifier chain callbacks. It is controlled through debugfs
1751 interface /sys/kernel/debug/notifier-error-inject/netdev
1753 If the notifier call chain should be failed with some events
1754 notified, write the error code to "actions/<notifier event>/error".
1756 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1758 # cd /sys/kernel/debug/notifier-error-inject/netdev
1759 # echo -22 > actions/NETDEV_CHANGEMTU/error
1760 # ip link set eth0 mtu 1024
1761 RTNETLINK answers: Invalid argument
1763 To compile this code as a module, choose M here: the module will
1764 be called netdev-notifier-error-inject.
1768 config FUNCTION_ERROR_INJECTION
1770 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1772 config FAULT_INJECTION
1773 bool "Fault-injection framework"
1774 depends on DEBUG_KERNEL
1776 Provide fault-injection framework.
1777 For more details, see Documentation/fault-injection/.
1780 bool "Fault-injection capability for kmalloc"
1781 depends on FAULT_INJECTION
1782 depends on SLAB || SLUB
1784 Provide fault-injection capability for kmalloc.
1786 config FAIL_PAGE_ALLOC
1787 bool "Fault-injection capability for alloc_pages()"
1788 depends on FAULT_INJECTION
1790 Provide fault-injection capability for alloc_pages().
1792 config FAIL_MAKE_REQUEST
1793 bool "Fault-injection capability for disk IO"
1794 depends on FAULT_INJECTION && BLOCK
1796 Provide fault-injection capability for disk IO.
1798 config FAIL_IO_TIMEOUT
1799 bool "Fault-injection capability for faking disk interrupts"
1800 depends on FAULT_INJECTION && BLOCK
1802 Provide fault-injection capability on end IO handling. This
1803 will make the block layer "forget" an interrupt as configured,
1804 thus exercising the error handling.
1806 Only works with drivers that use the generic timeout handling,
1807 for others it wont do anything.
1810 bool "Fault-injection capability for futexes"
1812 depends on FAULT_INJECTION && FUTEX
1814 Provide fault-injection capability for futexes.
1816 config FAULT_INJECTION_DEBUG_FS
1817 bool "Debugfs entries for fault-injection capabilities"
1818 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1820 Enable configuration of fault-injection capabilities via debugfs.
1822 config FAIL_FUNCTION
1823 bool "Fault-injection capability for functions"
1824 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1826 Provide function-based fault-injection capability.
1827 This will allow you to override a specific function with a return
1828 with given return value. As a result, function caller will see
1829 an error value and have to handle it. This is useful to test the
1830 error handling in various subsystems.
1832 config FAIL_MMC_REQUEST
1833 bool "Fault-injection capability for MMC IO"
1834 depends on FAULT_INJECTION_DEBUG_FS && MMC
1836 Provide fault-injection capability for MMC IO.
1837 This will make the mmc core return data errors. This is
1838 useful to test the error handling in the mmc block device
1839 and to test how the mmc host driver handles retries from
1842 config FAULT_INJECTION_STACKTRACE_FILTER
1843 bool "stacktrace filter for fault-injection capabilities"
1844 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1847 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1849 Provide stacktrace filter for fault-injection capabilities
1851 config ARCH_HAS_KCOV
1854 An architecture should select this when it can successfully
1855 build and run with CONFIG_KCOV. This typically requires
1856 disabling instrumentation for some early boot code.
1858 config CC_HAS_SANCOV_TRACE_PC
1859 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1863 bool "Code coverage for fuzzing"
1864 depends on ARCH_HAS_KCOV
1865 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1867 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1869 KCOV exposes kernel code coverage information in a form suitable
1870 for coverage-guided fuzzing (randomized testing).
1872 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1873 different machines and across reboots. If you need stable PC values,
1874 disable RANDOMIZE_BASE.
1876 For more details, see Documentation/dev-tools/kcov.rst.
1878 config KCOV_ENABLE_COMPARISONS
1879 bool "Enable comparison operands collection by KCOV"
1881 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1883 KCOV also exposes operands of every comparison in the instrumented
1884 code along with operand sizes and PCs of the comparison instructions.
1885 These operands can be used by fuzzing engines to improve the quality
1886 of fuzzing coverage.
1888 config KCOV_INSTRUMENT_ALL
1889 bool "Instrument all code by default"
1893 If you are doing generic system call fuzzing (like e.g. syzkaller),
1894 then you will want to instrument the whole kernel and you should
1895 say y here. If you are doing more targeted fuzzing (like e.g.
1896 filesystem fuzzing with AFL) then you will want to enable coverage
1897 for more specific subsets of files, and should say n here.
1899 config KCOV_IRQ_AREA_SIZE
1900 hex "Size of interrupt coverage collection area in words"
1904 KCOV uses preallocated per-cpu areas to collect coverage from
1905 soft interrupts. This specifies the size of those areas in the
1906 number of unsigned long words.
1908 menuconfig RUNTIME_TESTING_MENU
1909 bool "Runtime Testing"
1912 if RUNTIME_TESTING_MENU
1915 tristate "Linux Kernel Dump Test Tool Module"
1918 This module enables testing of the different dumping mechanisms by
1919 inducing system failures at predefined crash points.
1920 If you don't need it: say N
1921 Choose M here to compile this code as a module. The module will be
1924 Documentation on how to use the module can be found in
1925 Documentation/fault-injection/provoke-crashes.rst
1927 config TEST_LIST_SORT
1928 tristate "Linked list sorting test"
1929 depends on DEBUG_KERNEL || m
1931 Enable this to turn on 'list_sort()' function test. This test is
1932 executed only once during system boot (so affects only boot time),
1933 or at module load time.
1937 config TEST_MIN_HEAP
1938 tristate "Min heap test"
1939 depends on DEBUG_KERNEL || m
1941 Enable this to turn on min heap function tests. This test is
1942 executed only once during system boot (so affects only boot time),
1943 or at module load time.
1948 tristate "Array-based sort test"
1949 depends on DEBUG_KERNEL || m
1951 This option enables the self-test function of 'sort()' at boot,
1952 or at module load time.
1956 config KPROBES_SANITY_TEST
1957 bool "Kprobes sanity tests"
1958 depends on DEBUG_KERNEL
1961 This option provides for testing basic kprobes functionality on
1962 boot. Samples of kprobe and kretprobe are inserted and
1963 verified for functionality.
1965 Say N if you are unsure.
1967 config BACKTRACE_SELF_TEST
1968 tristate "Self test for the backtrace code"
1969 depends on DEBUG_KERNEL
1971 This option provides a kernel module that can be used to test
1972 the kernel stack backtrace code. This option is not useful
1973 for distributions or general kernels, but only for kernel
1974 developers working on architecture code.
1976 Note that if you want to also test saved backtraces, you will
1977 have to enable STACKTRACE as well.
1979 Say N if you are unsure.
1982 tristate "Red-Black tree test"
1983 depends on DEBUG_KERNEL
1985 A benchmark measuring the performance of the rbtree library.
1986 Also includes rbtree invariant checks.
1988 config REED_SOLOMON_TEST
1989 tristate "Reed-Solomon library test"
1990 depends on DEBUG_KERNEL || m
1992 select REED_SOLOMON_ENC16
1993 select REED_SOLOMON_DEC16
1995 This option enables the self-test function of rslib at boot,
1996 or at module load time.
2000 config INTERVAL_TREE_TEST
2001 tristate "Interval tree test"
2002 depends on DEBUG_KERNEL
2003 select INTERVAL_TREE
2005 A benchmark measuring the performance of the interval tree library
2008 tristate "Per cpu operations test"
2009 depends on m && DEBUG_KERNEL
2011 Enable this option to build test module which validates per-cpu
2016 config ATOMIC64_SELFTEST
2017 tristate "Perform an atomic64_t self-test"
2019 Enable this option to test the atomic64_t functions at boot or
2020 at module load time.
2024 config ASYNC_RAID6_TEST
2025 tristate "Self test for hardware accelerated raid6 recovery"
2026 depends on ASYNC_RAID6_RECOV
2029 This is a one-shot self test that permutes through the
2030 recovery of all the possible two disk failure scenarios for a
2031 N-disk array. Recovery is performed with the asynchronous
2032 raid6 recovery routines, and will optionally use an offload
2033 engine if one is available.
2038 tristate "Test functions located in the hexdump module at runtime"
2040 config TEST_STRING_HELPERS
2041 tristate "Test functions located in the string_helpers module at runtime"
2044 tristate "Test strscpy*() family of functions at runtime"
2047 tristate "Test kstrto*() family of functions at runtime"
2050 tristate "Test printf() family of functions at runtime"
2053 tristate "Test bitmap_*() family of functions at runtime"
2055 Enable this option to test the bitmap functions at boot.
2059 config TEST_BITFIELD
2060 tristate "Test bitfield functions at runtime"
2062 Enable this option to test the bitfield functions at boot.
2067 tristate "Test functions located in the uuid module at runtime"
2070 tristate "Test the XArray code at runtime"
2072 config TEST_OVERFLOW
2073 tristate "Test check_*_overflow() functions at runtime"
2075 config TEST_RHASHTABLE
2076 tristate "Perform selftest on resizable hash table"
2078 Enable this option to test the rhashtable functions at boot.
2083 tristate "Perform selftest on hash functions"
2085 Enable this option to test the kernel's integer (<linux/hash.h>),
2086 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2087 hash functions on boot (or module load).
2089 This is intended to help people writing architecture-specific
2090 optimized versions. If unsure, say N.
2093 tristate "Perform selftest on IDA functions"
2096 tristate "Perform selftest on priority array manager"
2099 Enable this option to test priority array manager on boot
2104 config TEST_IRQ_TIMINGS
2105 bool "IRQ timings selftest"
2106 depends on IRQ_TIMINGS
2108 Enable this option to test the irq timings code on boot.
2113 tristate "Test module loading with 'hello world' module"
2116 This builds the "test_module" module that emits "Hello, world"
2117 on printk when loaded. It is designed to be used for basic
2118 evaluation of the module loading subsystem (for example when
2119 validating module verification). It lacks any extra dependencies,
2120 and will not normally be loaded by the system unless explicitly
2126 tristate "Test module for compilation of bitops operations"
2129 This builds the "test_bitops" module that is much like the
2130 TEST_LKM module except that it does a basic exercise of the
2131 set/clear_bit macros and get_count_order/long to make sure there are
2132 no compiler warnings from C=1 sparse checker or -Wextra
2133 compilations. It has no dependencies and doesn't run or load unless
2134 explicitly requested by name. for example: modprobe test_bitops.
2139 tristate "Test module for stress/performance analysis of vmalloc allocator"
2144 This builds the "test_vmalloc" module that should be used for
2145 stress and performance analysis. So, any new change for vmalloc
2146 subsystem can be evaluated from performance and stability point
2151 config TEST_USER_COPY
2152 tristate "Test user/kernel boundary protections"
2155 This builds the "test_user_copy" module that runs sanity checks
2156 on the copy_to/from_user infrastructure, making sure basic
2157 user/kernel boundary testing is working. If it fails to load,
2158 a regression has been detected in the user/kernel memory boundary
2164 tristate "Test BPF filter functionality"
2167 This builds the "test_bpf" module that runs various test vectors
2168 against the BPF interpreter or BPF JIT compiler depending on the
2169 current setting. This is in particular useful for BPF JIT compiler
2170 development, but also to run regression tests against changes in
2171 the interpreter code. It also enables test stubs for eBPF maps and
2172 verifier used by user space verifier testsuite.
2176 config TEST_BLACKHOLE_DEV
2177 tristate "Test blackhole netdev functionality"
2180 This builds the "test_blackhole_dev" module that validates the
2181 data path through this blackhole netdev.
2185 config FIND_BIT_BENCHMARK
2186 tristate "Test find_bit functions"
2188 This builds the "test_find_bit" module that measure find_*_bit()
2189 functions performance.
2193 config TEST_FIRMWARE
2194 tristate "Test firmware loading via userspace interface"
2195 depends on FW_LOADER
2197 This builds the "test_firmware" module that creates a userspace
2198 interface for testing firmware loading. This can be used to
2199 control the triggering of firmware loading without needing an
2200 actual firmware-using device. The contents can be rechecked by
2206 tristate "sysctl test driver"
2207 depends on PROC_SYSCTL
2209 This builds the "test_sysctl" module. This driver enables to test the
2210 proc sysctl interfaces available to drivers safely without affecting
2211 production knobs which might alter system functionality.
2215 config SYSCTL_KUNIT_TEST
2216 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2218 default KUNIT_ALL_TESTS
2220 This builds the proc sysctl unit test, which runs on boot.
2221 Tests the API contract and implementation correctness of sysctl.
2222 For more information on KUnit and unit tests in general please refer
2223 to the KUnit documentation in Documentation/dev-tools/kunit/.
2227 config LIST_KUNIT_TEST
2228 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2230 default KUNIT_ALL_TESTS
2232 This builds the linked list KUnit test suite.
2233 It tests that the API and basic functionality of the list_head type
2234 and associated macros.
2236 KUnit tests run during boot and output the results to the debug log
2237 in TAP format (https://testanything.org/). Only useful for kernel devs
2238 running the KUnit test harness, and not intended for inclusion into a
2241 For more information on KUnit and unit tests in general please refer
2242 to the KUnit documentation in Documentation/dev-tools/kunit/.
2246 config LINEAR_RANGES_TEST
2247 tristate "KUnit test for linear_ranges"
2249 select LINEAR_RANGES
2251 This builds the linear_ranges unit test, which runs on boot.
2252 Tests the linear_ranges logic correctness.
2253 For more information on KUnit and unit tests in general please refer
2254 to the KUnit documentation in Documentation/dev-tools/kunit/.
2259 tristate "KUnit test for bits.h"
2262 This builds the bits unit test.
2263 Tests the logic of macros defined in bits.h.
2264 For more information on KUnit and unit tests in general please refer
2265 to the KUnit documentation in Documentation/dev-tools/kunit/.
2270 tristate "udelay test driver"
2272 This builds the "udelay_test" module that helps to make sure
2273 that udelay() is working properly.
2277 config TEST_STATIC_KEYS
2278 tristate "Test static keys"
2281 Test the static key interfaces.
2286 tristate "kmod stress tester"
2288 depends on NETDEVICES && NET_CORE && INET # for TUN
2295 Test the kernel's module loading mechanism: kmod. kmod implements
2296 support to load modules using the Linux kernel's usermode helper.
2297 This test provides a series of tests against kmod.
2299 Although technically you can either build test_kmod as a module or
2300 into the kernel we disallow building it into the kernel since
2301 it stress tests request_module() and this will very likely cause
2302 some issues by taking over precious threads available from other
2303 module load requests, ultimately this could be fatal.
2307 tools/testing/selftests/kmod/kmod.sh --help
2311 config TEST_DEBUG_VIRTUAL
2312 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2313 depends on DEBUG_VIRTUAL
2315 Test the kernel's ability to detect incorrect calls to
2316 virt_to_phys() done against the non-linear part of the
2317 kernel's virtual address map.
2321 config TEST_MEMCAT_P
2322 tristate "Test memcat_p() helper function"
2324 Test the memcat_p() helper for correctly merging two
2325 pointer arrays together.
2329 config TEST_LIVEPATCH
2330 tristate "Test livepatching"
2332 depends on DYNAMIC_DEBUG
2333 depends on LIVEPATCH
2336 Test kernel livepatching features for correctness. The tests will
2337 load test modules that will be livepatched in various scenarios.
2339 To run all the livepatching tests:
2341 make -C tools/testing/selftests TARGETS=livepatch run_tests
2343 Alternatively, individual tests may be invoked:
2345 tools/testing/selftests/livepatch/test-callbacks.sh
2346 tools/testing/selftests/livepatch/test-livepatch.sh
2347 tools/testing/selftests/livepatch/test-shadow-vars.sh
2352 tristate "Perform selftest on object aggreration manager"
2356 Enable this option to test object aggregation manager on boot
2360 config TEST_STACKINIT
2361 tristate "Test level of stack variable initialization"
2363 Test if the kernel is zero-initializing stack variables and
2364 padding. Coverage is controlled by compiler flags,
2365 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2366 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2371 tristate "Test heap/page initialization"
2373 Test if the kernel is zero-initializing heap and page allocations.
2374 This can be useful to test init_on_alloc and init_on_free features.
2379 tristate "Test HMM (Heterogeneous Memory Management)"
2380 depends on TRANSPARENT_HUGEPAGE
2381 depends on DEVICE_PRIVATE
2385 This is a pseudo device driver solely for testing HMM.
2386 Say M here if you want to build the HMM test module.
2387 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2392 tristate "Test floating point operations in kernel space"
2393 depends on X86 && !KCOV_INSTRUMENT_ALL
2395 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2396 which will trigger a sequence of floating point operations. This is used
2397 for self-testing floating point control register setting in
2402 endif # RUNTIME_TESTING_MENU
2407 This option adds a kernel parameter 'memtest', which allows memtest
2409 memtest=0, mean disabled; -- default
2410 memtest=1, mean do 1 test pattern;
2412 memtest=17, mean do 17 test patterns.
2413 If you are unsure how to answer this question, answer N.
2417 config HYPERV_TESTING
2418 bool "Microsoft Hyper-V driver testing"
2420 depends on HYPERV && DEBUG_FS
2422 Select this option to enable Hyper-V vmbus testing.
2424 endmenu # "Kernel Testing and Coverage"
2426 endmenu # Kernel hacking