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.
217 config DEBUG_INFO_REDUCED
218 bool "Reduce debugging information"
220 If you say Y here gcc is instructed to generate less debugging
221 information for structure types. This means that tools that
222 need full debugging information (like kgdb or systemtap) won't
223 be happy. But if you merely need debugging information to
224 resolve line numbers there is no loss. Advantage is that
225 build directory object sizes shrink dramatically over a full
226 DEBUG_INFO build and compile times are reduced too.
227 Only works with newer gcc versions.
229 config DEBUG_INFO_COMPRESSED
230 bool "Compressed debugging information"
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 $(cc-option,-gsplit-dwarf)
248 Generate debug info into separate .dwo files. This significantly
249 reduces the build directory size for builds with DEBUG_INFO,
250 because it stores the information only once on disk in .dwo
251 files instead of multiple times in object files and executables.
252 In addition the debug information is also compressed.
254 Requires recent gcc (4.7+) and recent gdb/binutils.
255 Any tool that packages or reads debug information would need
256 to know about the .dwo files and include them.
257 Incompatible with older versions of ccache.
260 prompt "DWARF version"
262 Which version of DWARF debug info to emit.
264 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
265 bool "Rely on the toolchain's implicit default DWARF version"
267 The implicit default version of DWARF debug info produced by a
268 toolchain changes over time.
270 This can break consumers of the debug info that haven't upgraded to
271 support newer revisions, and prevent testing newer versions, but
272 those should be less common scenarios.
276 config DEBUG_INFO_DWARF4
277 bool "Generate DWARF Version 4 debuginfo"
279 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
281 If you have consumers of DWARF debug info that are not ready for
282 newer revisions of DWARF, you may wish to choose this or have your
285 config DEBUG_INFO_DWARF5
286 bool "Generate DWARF Version 5 debuginfo"
287 depends on GCC_VERSION >= 50000 || CC_IS_CLANG
288 depends on CC_IS_GCC || $(success,$(srctree)/scripts/test_dwarf5_support.sh $(CC) $(CLANG_FLAGS))
289 depends on !DEBUG_INFO_BTF
291 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
292 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
293 draft features until 7.0), and gdb 8.0+.
295 Changes to the structure of debug info in Version 5 allow for around
296 15-18% savings in resulting image and debug info section sizes as
297 compared to DWARF Version 4. DWARF Version 5 standardizes previous
298 extensions such as accelerators for symbol indexing and the format
299 for fission (.dwo/.dwp) files. Users may not want to select this
300 config if they rely on tooling that has not yet been updated to
301 support DWARF Version 5.
303 endchoice # "DWARF version"
305 config DEBUG_INFO_BTF
306 bool "Generate BTF typeinfo"
307 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
308 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
310 Generate deduplicated BTF type information from DWARF debug info.
311 Turning this on expects presence of pahole tool, which will convert
312 DWARF type info into equivalent deduplicated BTF type info.
314 config PAHOLE_HAS_SPLIT_BTF
315 def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119")
317 config DEBUG_INFO_BTF_MODULES
319 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
321 Generate compact split BTF type information for kernel modules.
324 bool "Provide GDB scripts for kernel debugging"
326 This creates the required links to GDB helper scripts in the
327 build directory. If you load vmlinux into gdb, the helper
328 scripts will be automatically imported by gdb as well, and
329 additional functions are available to analyze a Linux kernel
330 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
336 int "Warn for stack frames larger than"
338 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
339 default 1280 if (!64BIT && PARISC)
340 default 1024 if (!64BIT && !PARISC)
341 default 2048 if 64BIT
343 Tell gcc to warn at build time for stack frames larger than this.
344 Setting this too low will cause a lot of warnings.
345 Setting it to 0 disables the warning.
347 config STRIP_ASM_SYMS
348 bool "Strip assembler-generated symbols during link"
351 Strip internal assembler-generated symbols during a link (symbols
352 that look like '.Lxxx') so they don't pollute the output of
353 get_wchan() and suchlike.
356 bool "Generate readable assembler code"
357 depends on DEBUG_KERNEL
359 Disable some compiler optimizations that tend to generate human unreadable
360 assembler output. This may make the kernel slightly slower, but it helps
361 to keep kernel developers who have to stare a lot at assembler listings
364 config HEADERS_INSTALL
365 bool "Install uapi headers to usr/include"
368 This option will install uapi headers (headers exported to user-space)
369 into the usr/include directory for use during the kernel build.
370 This is unneeded for building the kernel itself, but needed for some
371 user-space program samples. It is also needed by some features such
372 as uapi header sanity checks.
374 config DEBUG_SECTION_MISMATCH
375 bool "Enable full Section mismatch analysis"
377 The section mismatch analysis checks if there are illegal
378 references from one section to another section.
379 During linktime or runtime, some sections are dropped;
380 any use of code/data previously in these sections would
381 most likely result in an oops.
382 In the code, functions and variables are annotated with
383 __init,, etc. (see the full list in include/linux/init.h),
384 which results in the code/data being placed in specific sections.
385 The section mismatch analysis is always performed after a full
386 kernel build, and enabling this option causes the following
387 additional step to occur:
388 - Add the option -fno-inline-functions-called-once to gcc commands.
389 When inlining a function annotated with __init in a non-init
390 function, we would lose the section information and thus
391 the analysis would not catch the illegal reference.
392 This option tells gcc to inline less (but it does result in
395 config SECTION_MISMATCH_WARN_ONLY
396 bool "Make section mismatch errors non-fatal"
399 If you say N here, the build process will fail if there are any
400 section mismatch, instead of just throwing warnings.
404 config DEBUG_FORCE_FUNCTION_ALIGN_32B
405 bool "Force all function address 32B aligned" if EXPERT
407 There are cases that a commit from one domain changes the function
408 address alignment of other domains, and cause magic performance
409 bump (regression or improvement). Enable this option will help to
410 verify if the bump is caused by function alignment changes, while
411 it will slightly increase the kernel size and affect icache usage.
413 It is mainly for debug and performance tuning use.
416 # Select this config option from the architecture Kconfig, if it
417 # is preferred to always offer frame pointers as a config
418 # option on the architecture (regardless of KERNEL_DEBUG):
420 config ARCH_WANT_FRAME_POINTERS
424 bool "Compile the kernel with frame pointers"
425 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
426 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
428 If you say Y here the resulting kernel image will be slightly
429 larger and slower, but it gives very useful debugging information
430 in case of kernel bugs. (precise oopses/stacktraces/warnings)
432 config STACK_VALIDATION
433 bool "Compile-time stack metadata validation"
434 depends on HAVE_STACK_VALIDATION
437 Add compile-time checks to validate stack metadata, including frame
438 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
439 that runtime stack traces are more reliable.
441 This is also a prerequisite for generation of ORC unwind data, which
442 is needed for CONFIG_UNWINDER_ORC.
444 For more information, see
445 tools/objtool/Documentation/stack-validation.txt.
447 config VMLINUX_VALIDATION
449 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
452 config DEBUG_FORCE_WEAK_PER_CPU
453 bool "Force weak per-cpu definitions"
454 depends on DEBUG_KERNEL
456 s390 and alpha require percpu variables in modules to be
457 defined weak to work around addressing range issue which
458 puts the following two restrictions on percpu variable
461 1. percpu symbols must be unique whether static or not
462 2. percpu variables can't be defined inside a function
464 To ensure that generic code follows the above rules, this
465 option forces all percpu variables to be defined as weak.
467 endmenu # "Compiler options"
469 menu "Generic Kernel Debugging Instruments"
472 bool "Magic SysRq key"
475 If you say Y here, you will have some control over the system even
476 if the system crashes for example during kernel debugging (e.g., you
477 will be able to flush the buffer cache to disk, reboot the system
478 immediately or dump some status information). This is accomplished
479 by pressing various keys while holding SysRq (Alt+PrintScreen). It
480 also works on a serial console (on PC hardware at least), if you
481 send a BREAK and then within 5 seconds a command keypress. The
482 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
483 Don't say Y unless you really know what this hack does.
485 config MAGIC_SYSRQ_DEFAULT_ENABLE
486 hex "Enable magic SysRq key functions by default"
487 depends on MAGIC_SYSRQ
490 Specifies which SysRq key functions are enabled by default.
491 This may be set to 1 or 0 to enable or disable them all, or
492 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
494 config MAGIC_SYSRQ_SERIAL
495 bool "Enable magic SysRq key over serial"
496 depends on MAGIC_SYSRQ
499 Many embedded boards have a disconnected TTL level serial which can
500 generate some garbage that can lead to spurious false sysrq detects.
501 This option allows you to decide whether you want to enable the
504 config MAGIC_SYSRQ_SERIAL_SEQUENCE
505 string "Char sequence that enables magic SysRq over serial"
506 depends on MAGIC_SYSRQ_SERIAL
509 Specifies a sequence of characters that can follow BREAK to enable
510 SysRq on a serial console.
512 If unsure, leave an empty string and the option will not be enabled.
515 bool "Debug Filesystem"
517 debugfs is a virtual file system that kernel developers use to put
518 debugging files into. Enable this option to be able to read and
519 write to these files.
521 For detailed documentation on the debugfs API, see
522 Documentation/filesystems/.
527 prompt "Debugfs default access"
529 default DEBUG_FS_ALLOW_ALL
531 This selects the default access restrictions for debugfs.
532 It can be overridden with kernel command line option
533 debugfs=[on,no-mount,off]. The restrictions apply for API access
534 and filesystem registration.
536 config DEBUG_FS_ALLOW_ALL
539 No restrictions apply. Both API and filesystem registration
540 is on. This is the normal default operation.
542 config DEBUG_FS_DISALLOW_MOUNT
543 bool "Do not register debugfs as filesystem"
545 The API is open but filesystem is not loaded. Clients can still do
546 their work and read with debug tools that do not need
549 config DEBUG_FS_ALLOW_NONE
552 Access is off. Clients get -PERM when trying to create nodes in
553 debugfs tree and debugfs is not registered as a filesystem.
554 Client can then back-off or continue without debugfs access.
558 source "lib/Kconfig.kgdb"
559 source "lib/Kconfig.ubsan"
560 source "lib/Kconfig.kcsan"
565 bool "Kernel debugging"
567 Say Y here if you are developing drivers or trying to debug and
568 identify kernel problems.
571 bool "Miscellaneous debug code"
573 depends on DEBUG_KERNEL
575 Say Y here if you need to enable miscellaneous debug code that should
576 be under a more specific debug option but isn't.
579 menu "Memory Debugging"
581 source "mm/Kconfig.debug"
584 bool "Debug object operations"
585 depends on DEBUG_KERNEL
587 If you say Y here, additional code will be inserted into the
588 kernel to track the life time of various objects and validate
589 the operations on those objects.
591 config DEBUG_OBJECTS_SELFTEST
592 bool "Debug objects selftest"
593 depends on DEBUG_OBJECTS
595 This enables the selftest of the object debug code.
597 config DEBUG_OBJECTS_FREE
598 bool "Debug objects in freed memory"
599 depends on DEBUG_OBJECTS
601 This enables checks whether a k/v free operation frees an area
602 which contains an object which has not been deactivated
603 properly. This can make kmalloc/kfree-intensive workloads
606 config DEBUG_OBJECTS_TIMERS
607 bool "Debug timer objects"
608 depends on DEBUG_OBJECTS
610 If you say Y here, additional code will be inserted into the
611 timer routines to track the life time of timer objects and
612 validate the timer operations.
614 config DEBUG_OBJECTS_WORK
615 bool "Debug work objects"
616 depends on DEBUG_OBJECTS
618 If you say Y here, additional code will be inserted into the
619 work queue routines to track the life time of work objects and
620 validate the work operations.
622 config DEBUG_OBJECTS_RCU_HEAD
623 bool "Debug RCU callbacks objects"
624 depends on DEBUG_OBJECTS
626 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
628 config DEBUG_OBJECTS_PERCPU_COUNTER
629 bool "Debug percpu counter objects"
630 depends on DEBUG_OBJECTS
632 If you say Y here, additional code will be inserted into the
633 percpu counter routines to track the life time of percpu counter
634 objects and validate the percpu counter operations.
636 config DEBUG_OBJECTS_ENABLE_DEFAULT
637 int "debug_objects bootup default value (0-1)"
640 depends on DEBUG_OBJECTS
642 Debug objects boot parameter default value
645 bool "Debug slab memory allocations"
646 depends on DEBUG_KERNEL && SLAB
648 Say Y here to have the kernel do limited verification on memory
649 allocation as well as poisoning memory on free to catch use of freed
650 memory. This can make kmalloc/kfree-intensive workloads much slower.
653 bool "SLUB debugging on by default"
654 depends on SLUB && SLUB_DEBUG
657 Boot with debugging on by default. SLUB boots by default with
658 the runtime debug capabilities switched off. Enabling this is
659 equivalent to specifying the "slub_debug" parameter on boot.
660 There is no support for more fine grained debug control like
661 possible with slub_debug=xxx. SLUB debugging may be switched
662 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
667 bool "Enable SLUB performance statistics"
668 depends on SLUB && SYSFS
670 SLUB statistics are useful to debug SLUBs allocation behavior in
671 order find ways to optimize the allocator. This should never be
672 enabled for production use since keeping statistics slows down
673 the allocator by a few percentage points. The slabinfo command
674 supports the determination of the most active slabs to figure
675 out which slabs are relevant to a particular load.
676 Try running: slabinfo -DA
678 config HAVE_DEBUG_KMEMLEAK
681 config DEBUG_KMEMLEAK
682 bool "Kernel memory leak detector"
683 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
685 select STACKTRACE if STACKTRACE_SUPPORT
689 Say Y here if you want to enable the memory leak
690 detector. The memory allocation/freeing is traced in a way
691 similar to the Boehm's conservative garbage collector, the
692 difference being that the orphan objects are not freed but
693 only shown in /sys/kernel/debug/kmemleak. Enabling this
694 feature will introduce an overhead to memory
695 allocations. See Documentation/dev-tools/kmemleak.rst for more
698 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
699 of finding leaks due to the slab objects poisoning.
701 In order to access the kmemleak file, debugfs needs to be
702 mounted (usually at /sys/kernel/debug).
704 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
705 int "Kmemleak memory pool size"
706 depends on DEBUG_KMEMLEAK
710 Kmemleak must track all the memory allocations to avoid
711 reporting false positives. Since memory may be allocated or
712 freed before kmemleak is fully initialised, use a static pool
713 of metadata objects to track such callbacks. After kmemleak is
714 fully initialised, this memory pool acts as an emergency one
715 if slab allocations fail.
717 config DEBUG_KMEMLEAK_TEST
718 tristate "Simple test for the kernel memory leak detector"
719 depends on DEBUG_KMEMLEAK && m
721 This option enables a module that explicitly leaks memory.
725 config DEBUG_KMEMLEAK_DEFAULT_OFF
726 bool "Default kmemleak to off"
727 depends on DEBUG_KMEMLEAK
729 Say Y here to disable kmemleak by default. It can then be enabled
730 on the command line via kmemleak=on.
732 config DEBUG_KMEMLEAK_AUTO_SCAN
733 bool "Enable kmemleak auto scan thread on boot up"
735 depends on DEBUG_KMEMLEAK
737 Depending on the cpu, kmemleak scan may be cpu intensive and can
738 stall user tasks at times. This option enables/disables automatic
739 kmemleak scan at boot up.
741 Say N here to disable kmemleak auto scan thread to stop automatic
742 scanning. Disabling this option disables automatic reporting of
747 config DEBUG_STACK_USAGE
748 bool "Stack utilization instrumentation"
749 depends on DEBUG_KERNEL && !IA64
751 Enables the display of the minimum amount of free stack which each
752 task has ever had available in the sysrq-T and sysrq-P debug output.
754 This option will slow down process creation somewhat.
756 config SCHED_STACK_END_CHECK
757 bool "Detect stack corruption on calls to schedule()"
758 depends on DEBUG_KERNEL
761 This option checks for a stack overrun on calls to schedule().
762 If the stack end location is found to be over written always panic as
763 the content of the corrupted region can no longer be trusted.
764 This is to ensure no erroneous behaviour occurs which could result in
765 data corruption or a sporadic crash at a later stage once the region
766 is examined. The runtime overhead introduced is minimal.
768 config ARCH_HAS_DEBUG_VM_PGTABLE
771 An architecture should select this when it can successfully
772 build and run DEBUG_VM_PGTABLE.
776 depends on DEBUG_KERNEL
778 Enable this to turn on extended checks in the virtual-memory system
779 that may impact performance.
783 config DEBUG_VM_VMACACHE
784 bool "Debug VMA caching"
787 Enable this to turn on VMA caching debug information. Doing so
788 can cause significant overhead, so only enable it in non-production
794 bool "Debug VM red-black trees"
797 Enable VM red-black tree debugging information and extra validations.
801 config DEBUG_VM_PGFLAGS
802 bool "Debug page-flags operations"
805 Enables extra validation on page flags operations.
809 config DEBUG_VM_PGTABLE
810 bool "Debug arch page table for semantics compliance"
812 depends on ARCH_HAS_DEBUG_VM_PGTABLE
813 default y if DEBUG_VM
815 This option provides a debug method which can be used to test
816 architecture page table helper functions on various platforms in
817 verifying if they comply with expected generic MM semantics. This
818 will help architecture code in making sure that any changes or
819 new additions of these helpers still conform to expected
820 semantics of the generic MM. Platforms will have to opt in for
821 this through ARCH_HAS_DEBUG_VM_PGTABLE.
825 config ARCH_HAS_DEBUG_VIRTUAL
829 bool "Debug VM translations"
830 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
832 Enable some costly sanity checks in virtual to page code. This can
833 catch mistakes with virt_to_page() and friends.
837 config DEBUG_NOMMU_REGIONS
838 bool "Debug the global anon/private NOMMU mapping region tree"
839 depends on DEBUG_KERNEL && !MMU
841 This option causes the global tree of anonymous and private mapping
842 regions to be regularly checked for invalid topology.
844 config DEBUG_MEMORY_INIT
845 bool "Debug memory initialisation" if EXPERT
848 Enable this for additional checks during memory initialisation.
849 The sanity checks verify aspects of the VM such as the memory model
850 and other information provided by the architecture. Verbose
851 information will be printed at KERN_DEBUG loglevel depending
852 on the mminit_loglevel= command-line option.
856 config MEMORY_NOTIFIER_ERROR_INJECT
857 tristate "Memory hotplug notifier error injection module"
858 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
860 This option provides the ability to inject artificial errors to
861 memory hotplug notifier chain callbacks. It is controlled through
862 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
864 If the notifier call chain should be failed with some events
865 notified, write the error code to "actions/<notifier event>/error".
867 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
869 # cd /sys/kernel/debug/notifier-error-inject/memory
870 # echo -12 > actions/MEM_GOING_OFFLINE/error
871 # echo offline > /sys/devices/system/memory/memoryXXX/state
872 bash: echo: write error: Cannot allocate memory
874 To compile this code as a module, choose M here: the module will
875 be called memory-notifier-error-inject.
879 config DEBUG_PER_CPU_MAPS
880 bool "Debug access to per_cpu maps"
881 depends on DEBUG_KERNEL
884 Say Y to verify that the per_cpu map being accessed has
885 been set up. This adds a fair amount of code to kernel memory
886 and decreases performance.
890 config DEBUG_KMAP_LOCAL
891 bool "Debug kmap_local temporary mappings"
892 depends on DEBUG_KERNEL && KMAP_LOCAL
894 This option enables additional error checking for the kmap_local
895 infrastructure. Disable for production use.
897 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
900 config DEBUG_KMAP_LOCAL_FORCE_MAP
901 bool "Enforce kmap_local temporary mappings"
902 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
904 select DEBUG_KMAP_LOCAL
906 This option enforces temporary mappings through the kmap_local
907 mechanism for non-highmem pages and on non-highmem systems.
908 Disable this for production systems!
911 bool "Highmem debugging"
912 depends on DEBUG_KERNEL && HIGHMEM
913 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
914 select DEBUG_KMAP_LOCAL
916 This option enables additional error checking for high memory
917 systems. Disable for production systems.
919 config HAVE_DEBUG_STACKOVERFLOW
922 config DEBUG_STACKOVERFLOW
923 bool "Check for stack overflows"
924 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
926 Say Y here if you want to check for overflows of kernel, IRQ
927 and exception stacks (if your architecture uses them). This
928 option will show detailed messages if free stack space drops
929 below a certain limit.
931 These kinds of bugs usually occur when call-chains in the
932 kernel get too deep, especially when interrupts are
935 Use this in cases where you see apparently random memory
936 corruption, especially if it appears in 'struct thread_info'
938 If in doubt, say "N".
940 source "lib/Kconfig.kasan"
941 source "lib/Kconfig.kfence"
943 endmenu # "Memory Debugging"
946 bool "Debug shared IRQ handlers"
947 depends on DEBUG_KERNEL
949 Enable this to generate a spurious interrupt just before a shared
950 interrupt handler is deregistered (generating one when registering
951 is currently disabled). Drivers need to handle this correctly. Some
952 don't and need to be caught.
954 menu "Debug Oops, Lockups and Hangs"
959 Say Y here to enable the kernel to panic when it oopses. This
960 has the same effect as setting oops=panic on the kernel command
963 This feature is useful to ensure that the kernel does not do
964 anything erroneous after an oops which could result in data
965 corruption or other issues.
969 config PANIC_ON_OOPS_VALUE
972 default 0 if !PANIC_ON_OOPS
973 default 1 if PANIC_ON_OOPS
979 Set the timeout value (in seconds) until a reboot occurs when
980 the kernel panics. If n = 0, then we wait forever. A timeout
981 value n > 0 will wait n seconds before rebooting, while a timeout
982 value n < 0 will reboot immediately.
984 config LOCKUP_DETECTOR
987 config SOFTLOCKUP_DETECTOR
988 bool "Detect Soft Lockups"
989 depends on DEBUG_KERNEL && !S390
990 select LOCKUP_DETECTOR
992 Say Y here to enable the kernel to act as a watchdog to detect
995 Softlockups are bugs that cause the kernel to loop in kernel
996 mode for more than 20 seconds, without giving other tasks a
997 chance to run. The current stack trace is displayed upon
998 detection and the system will stay locked up.
1000 config BOOTPARAM_SOFTLOCKUP_PANIC
1001 bool "Panic (Reboot) On Soft Lockups"
1002 depends on SOFTLOCKUP_DETECTOR
1004 Say Y here to enable the kernel to panic on "soft lockups",
1005 which are bugs that cause the kernel to loop in kernel
1006 mode for more than 20 seconds (configurable using the watchdog_thresh
1007 sysctl), without giving other tasks a chance to run.
1009 The panic can be used in combination with panic_timeout,
1010 to cause the system to reboot automatically after a
1011 lockup has been detected. This feature is useful for
1012 high-availability systems that have uptime guarantees and
1013 where a lockup must be resolved ASAP.
1017 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
1019 depends on SOFTLOCKUP_DETECTOR
1021 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
1022 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
1024 config HARDLOCKUP_DETECTOR_PERF
1026 select SOFTLOCKUP_DETECTOR
1029 # Enables a timestamp based low pass filter to compensate for perf based
1030 # hard lockup detection which runs too fast due to turbo modes.
1032 config HARDLOCKUP_CHECK_TIMESTAMP
1036 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1037 # lockup detector rather than the perf based detector.
1039 config HARDLOCKUP_DETECTOR
1040 bool "Detect Hard Lockups"
1041 depends on DEBUG_KERNEL && !S390
1042 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1043 select LOCKUP_DETECTOR
1044 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1045 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1047 Say Y here to enable the kernel to act as a watchdog to detect
1050 Hardlockups are bugs that cause the CPU to loop in kernel mode
1051 for more than 10 seconds, without letting other interrupts have a
1052 chance to run. The current stack trace is displayed upon detection
1053 and the system will stay locked up.
1055 config BOOTPARAM_HARDLOCKUP_PANIC
1056 bool "Panic (Reboot) On Hard Lockups"
1057 depends on HARDLOCKUP_DETECTOR
1059 Say Y here to enable the kernel to panic on "hard lockups",
1060 which are bugs that cause the kernel to loop in kernel
1061 mode with interrupts disabled for more than 10 seconds (configurable
1062 using the watchdog_thresh sysctl).
1066 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1068 depends on HARDLOCKUP_DETECTOR
1070 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1071 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1073 config DETECT_HUNG_TASK
1074 bool "Detect Hung Tasks"
1075 depends on DEBUG_KERNEL
1076 default SOFTLOCKUP_DETECTOR
1078 Say Y here to enable the kernel to detect "hung tasks",
1079 which are bugs that cause the task to be stuck in
1080 uninterruptible "D" state indefinitely.
1082 When a hung task is detected, the kernel will print the
1083 current stack trace (which you should report), but the
1084 task will stay in uninterruptible state. If lockdep is
1085 enabled then all held locks will also be reported. This
1086 feature has negligible overhead.
1088 config DEFAULT_HUNG_TASK_TIMEOUT
1089 int "Default timeout for hung task detection (in seconds)"
1090 depends on DETECT_HUNG_TASK
1093 This option controls the default timeout (in seconds) used
1094 to determine when a task has become non-responsive and should
1097 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1098 sysctl or by writing a value to
1099 /proc/sys/kernel/hung_task_timeout_secs.
1101 A timeout of 0 disables the check. The default is two minutes.
1102 Keeping the default should be fine in most cases.
1104 config BOOTPARAM_HUNG_TASK_PANIC
1105 bool "Panic (Reboot) On Hung Tasks"
1106 depends on DETECT_HUNG_TASK
1108 Say Y here to enable the kernel to panic on "hung tasks",
1109 which are bugs that cause the kernel to leave a task stuck
1110 in uninterruptible "D" state.
1112 The panic can be used in combination with panic_timeout,
1113 to cause the system to reboot automatically after a
1114 hung task has been detected. This feature is useful for
1115 high-availability systems that have uptime guarantees and
1116 where a hung tasks must be resolved ASAP.
1120 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1122 depends on DETECT_HUNG_TASK
1124 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1125 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1128 bool "Detect Workqueue Stalls"
1129 depends on DEBUG_KERNEL
1131 Say Y here to enable stall detection on workqueues. If a
1132 worker pool doesn't make forward progress on a pending work
1133 item for over a given amount of time, 30s by default, a
1134 warning message is printed along with dump of workqueue
1135 state. This can be configured through kernel parameter
1136 "workqueue.watchdog_thresh" and its sysfs counterpart.
1139 tristate "Test module to generate lockups"
1142 This builds the "test_lockup" module that helps to make sure
1143 that watchdogs and lockup detectors are working properly.
1145 Depending on module parameters it could emulate soft or hard
1146 lockup, "hung task", or locking arbitrary lock for a long time.
1147 Also it could generate series of lockups with cooling-down periods.
1151 endmenu # "Debug lockups and hangs"
1153 menu "Scheduler Debugging"
1156 bool "Collect scheduler debugging info"
1157 depends on DEBUG_KERNEL && PROC_FS
1160 If you say Y here, the /proc/sched_debug file will be provided
1161 that can help debug the scheduler. The runtime overhead of this
1169 bool "Collect scheduler statistics"
1170 depends on DEBUG_KERNEL && PROC_FS
1173 If you say Y here, additional code will be inserted into the
1174 scheduler and related routines to collect statistics about
1175 scheduler behavior and provide them in /proc/schedstat. These
1176 stats may be useful for both tuning and debugging the scheduler
1177 If you aren't debugging the scheduler or trying to tune a specific
1178 application, you can say N to avoid the very slight overhead
1183 config DEBUG_TIMEKEEPING
1184 bool "Enable extra timekeeping sanity checking"
1186 This option will enable additional timekeeping sanity checks
1187 which may be helpful when diagnosing issues where timekeeping
1188 problems are suspected.
1190 This may include checks in the timekeeping hotpaths, so this
1191 option may have a (very small) performance impact to some
1196 config DEBUG_PREEMPT
1197 bool "Debug preemptible kernel"
1198 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1201 If you say Y here then the kernel will use a debug variant of the
1202 commonly used smp_processor_id() function and will print warnings
1203 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1204 will detect preemption count underflows.
1206 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1208 config LOCK_DEBUGGING_SUPPORT
1210 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1213 config PROVE_LOCKING
1214 bool "Lock debugging: prove locking correctness"
1215 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1217 select DEBUG_SPINLOCK
1218 select DEBUG_MUTEXES
1219 select DEBUG_RT_MUTEXES if RT_MUTEXES
1221 select DEBUG_WW_MUTEX_SLOWPATH
1222 select DEBUG_LOCK_ALLOC
1223 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1224 select TRACE_IRQFLAGS
1227 This feature enables the kernel to prove that all locking
1228 that occurs in the kernel runtime is mathematically
1229 correct: that under no circumstance could an arbitrary (and
1230 not yet triggered) combination of observed locking
1231 sequences (on an arbitrary number of CPUs, running an
1232 arbitrary number of tasks and interrupt contexts) cause a
1235 In short, this feature enables the kernel to report locking
1236 related deadlocks before they actually occur.
1238 The proof does not depend on how hard and complex a
1239 deadlock scenario would be to trigger: how many
1240 participant CPUs, tasks and irq-contexts would be needed
1241 for it to trigger. The proof also does not depend on
1242 timing: if a race and a resulting deadlock is possible
1243 theoretically (no matter how unlikely the race scenario
1244 is), it will be proven so and will immediately be
1245 reported by the kernel (once the event is observed that
1246 makes the deadlock theoretically possible).
1248 If a deadlock is impossible (i.e. the locking rules, as
1249 observed by the kernel, are mathematically correct), the
1250 kernel reports nothing.
1252 NOTE: this feature can also be enabled for rwlocks, mutexes
1253 and rwsems - in which case all dependencies between these
1254 different locking variants are observed and mapped too, and
1255 the proof of observed correctness is also maintained for an
1256 arbitrary combination of these separate locking variants.
1258 For more details, see Documentation/locking/lockdep-design.rst.
1260 config PROVE_RAW_LOCK_NESTING
1261 bool "Enable raw_spinlock - spinlock nesting checks"
1262 depends on PROVE_LOCKING
1265 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1266 that the lock nesting rules for PREEMPT_RT enabled kernels are
1269 NOTE: There are known nesting problems. So if you enable this
1270 option expect lockdep splats until these problems have been fully
1271 addressed which is work in progress. This config switch allows to
1272 identify and analyze these problems. It will be removed and the
1273 check permanentely enabled once the main issues have been fixed.
1275 If unsure, select N.
1278 bool "Lock usage statistics"
1279 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1281 select DEBUG_SPINLOCK
1282 select DEBUG_MUTEXES
1283 select DEBUG_RT_MUTEXES if RT_MUTEXES
1284 select DEBUG_LOCK_ALLOC
1287 This feature enables tracking lock contention points
1289 For more details, see Documentation/locking/lockstat.rst
1291 This also enables lock events required by "perf lock",
1293 If you want to use "perf lock", you also need to turn on
1294 CONFIG_EVENT_TRACING.
1296 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1297 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1299 config DEBUG_RT_MUTEXES
1300 bool "RT Mutex debugging, deadlock detection"
1301 depends on DEBUG_KERNEL && RT_MUTEXES
1303 This allows rt mutex semantics violations and rt mutex related
1304 deadlocks (lockups) to be detected and reported automatically.
1306 config DEBUG_SPINLOCK
1307 bool "Spinlock and rw-lock debugging: basic checks"
1308 depends on DEBUG_KERNEL
1309 select UNINLINE_SPIN_UNLOCK
1311 Say Y here and build SMP to catch missing spinlock initialization
1312 and certain other kinds of spinlock errors commonly made. This is
1313 best used in conjunction with the NMI watchdog so that spinlock
1314 deadlocks are also debuggable.
1316 config DEBUG_MUTEXES
1317 bool "Mutex debugging: basic checks"
1318 depends on DEBUG_KERNEL
1320 This feature allows mutex semantics violations to be detected and
1323 config DEBUG_WW_MUTEX_SLOWPATH
1324 bool "Wait/wound mutex debugging: Slowpath testing"
1325 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1326 select DEBUG_LOCK_ALLOC
1327 select DEBUG_SPINLOCK
1328 select DEBUG_MUTEXES
1330 This feature enables slowpath testing for w/w mutex users by
1331 injecting additional -EDEADLK wound/backoff cases. Together with
1332 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1333 will test all possible w/w mutex interface abuse with the
1334 exception of simply not acquiring all the required locks.
1335 Note that this feature can introduce significant overhead, so
1336 it really should not be enabled in a production or distro kernel,
1337 even a debug kernel. If you are a driver writer, enable it. If
1338 you are a distro, do not.
1341 bool "RW Semaphore debugging: basic checks"
1342 depends on DEBUG_KERNEL
1344 This debugging feature allows mismatched rw semaphore locks
1345 and unlocks to be detected and reported.
1347 config DEBUG_LOCK_ALLOC
1348 bool "Lock debugging: detect incorrect freeing of live locks"
1349 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select DEBUG_SPINLOCK
1351 select DEBUG_MUTEXES
1352 select DEBUG_RT_MUTEXES if RT_MUTEXES
1355 This feature will check whether any held lock (spinlock, rwlock,
1356 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1357 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1358 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1359 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1360 held during task exit.
1364 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1366 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1370 config LOCKDEP_SMALL
1374 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1375 depends on LOCKDEP && !LOCKDEP_SMALL
1379 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1381 config LOCKDEP_CHAINS_BITS
1382 int "Bitsize for MAX_LOCKDEP_CHAINS"
1383 depends on LOCKDEP && !LOCKDEP_SMALL
1387 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1389 config LOCKDEP_STACK_TRACE_BITS
1390 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1391 depends on LOCKDEP && !LOCKDEP_SMALL
1395 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1397 config LOCKDEP_STACK_TRACE_HASH_BITS
1398 int "Bitsize for STACK_TRACE_HASH_SIZE"
1399 depends on LOCKDEP && !LOCKDEP_SMALL
1403 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1405 config LOCKDEP_CIRCULAR_QUEUE_BITS
1406 int "Bitsize for elements in circular_queue struct"
1411 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1413 config DEBUG_LOCKDEP
1414 bool "Lock dependency engine debugging"
1415 depends on DEBUG_KERNEL && LOCKDEP
1416 select DEBUG_IRQFLAGS
1418 If you say Y here, the lock dependency engine will do
1419 additional runtime checks to debug itself, at the price
1420 of more runtime overhead.
1422 config DEBUG_ATOMIC_SLEEP
1423 bool "Sleep inside atomic section checking"
1424 select PREEMPT_COUNT
1425 depends on DEBUG_KERNEL
1426 depends on !ARCH_NO_PREEMPT
1428 If you say Y here, various routines which may sleep will become very
1429 noisy if they are called inside atomic sections: when a spinlock is
1430 held, inside an rcu read side critical section, inside preempt disabled
1431 sections, inside an interrupt, etc...
1433 config DEBUG_LOCKING_API_SELFTESTS
1434 bool "Locking API boot-time self-tests"
1435 depends on DEBUG_KERNEL
1437 Say Y here if you want the kernel to run a short self-test during
1438 bootup. The self-test checks whether common types of locking bugs
1439 are detected by debugging mechanisms or not. (if you disable
1440 lock debugging then those bugs wont be detected of course.)
1441 The following locking APIs are covered: spinlocks, rwlocks,
1444 config LOCK_TORTURE_TEST
1445 tristate "torture tests for locking"
1446 depends on DEBUG_KERNEL
1449 This option provides a kernel module that runs torture tests
1450 on kernel locking primitives. The kernel module may be built
1451 after the fact on the running kernel to be tested, if desired.
1453 Say Y here if you want kernel locking-primitive torture tests
1454 to be built into the kernel.
1455 Say M if you want these torture tests to build as a module.
1456 Say N if you are unsure.
1458 config WW_MUTEX_SELFTEST
1459 tristate "Wait/wound mutex selftests"
1461 This option provides a kernel module that runs tests on the
1462 on the struct ww_mutex locking API.
1464 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1465 with this test harness.
1467 Say M if you want these self tests to build as a module.
1468 Say N if you are unsure.
1470 config SCF_TORTURE_TEST
1471 tristate "torture tests for smp_call_function*()"
1472 depends on DEBUG_KERNEL
1475 This option provides a kernel module that runs torture tests
1476 on the smp_call_function() family of primitives. The kernel
1477 module may be built after the fact on the running kernel to
1478 be tested, if desired.
1480 config CSD_LOCK_WAIT_DEBUG
1481 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1482 depends on DEBUG_KERNEL
1486 This option enables debug prints when CPUs are slow to respond
1487 to the smp_call_function*() IPI wrappers. These debug prints
1488 include the IPI handler function currently executing (if any)
1489 and relevant stack traces.
1491 endmenu # lock debugging
1493 config TRACE_IRQFLAGS
1494 depends on TRACE_IRQFLAGS_SUPPORT
1497 Enables hooks to interrupt enabling and disabling for
1498 either tracing or lock debugging.
1500 config TRACE_IRQFLAGS_NMI
1502 depends on TRACE_IRQFLAGS
1503 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1505 config DEBUG_IRQFLAGS
1506 bool "Debug IRQ flag manipulation"
1508 Enables checks for potentially unsafe enabling or disabling of
1509 interrupts, such as calling raw_local_irq_restore() when interrupts
1513 bool "Stack backtrace support"
1514 depends on STACKTRACE_SUPPORT
1516 This option causes the kernel to create a /proc/pid/stack for
1517 every process, showing its current stack trace.
1518 It is also used by various kernel debugging features that require
1519 stack trace generation.
1521 config WARN_ALL_UNSEEDED_RANDOM
1522 bool "Warn for all uses of unseeded randomness"
1525 Some parts of the kernel contain bugs relating to their use of
1526 cryptographically secure random numbers before it's actually possible
1527 to generate those numbers securely. This setting ensures that these
1528 flaws don't go unnoticed, by enabling a message, should this ever
1529 occur. This will allow people with obscure setups to know when things
1530 are going wrong, so that they might contact developers about fixing
1533 Unfortunately, on some models of some architectures getting
1534 a fully seeded CRNG is extremely difficult, and so this can
1535 result in dmesg getting spammed for a surprisingly long
1536 time. This is really bad from a security perspective, and
1537 so architecture maintainers really need to do what they can
1538 to get the CRNG seeded sooner after the system is booted.
1539 However, since users cannot do anything actionable to
1540 address this, by default the kernel will issue only a single
1541 warning for the first use of unseeded randomness.
1543 Say Y here if you want to receive warnings for all uses of
1544 unseeded randomness. This will be of use primarily for
1545 those developers interested in improving the security of
1546 Linux kernels running on their architecture (or
1549 config DEBUG_KOBJECT
1550 bool "kobject debugging"
1551 depends on DEBUG_KERNEL
1553 If you say Y here, some extra kobject debugging messages will be sent
1556 config DEBUG_KOBJECT_RELEASE
1557 bool "kobject release debugging"
1558 depends on DEBUG_OBJECTS_TIMERS
1560 kobjects are reference counted objects. This means that their
1561 last reference count put is not predictable, and the kobject can
1562 live on past the point at which a driver decides to drop it's
1563 initial reference to the kobject gained on allocation. An
1564 example of this would be a struct device which has just been
1567 However, some buggy drivers assume that after such an operation,
1568 the memory backing the kobject can be immediately freed. This
1569 goes completely against the principles of a refcounted object.
1571 If you say Y here, the kernel will delay the release of kobjects
1572 on the last reference count to improve the visibility of this
1573 kind of kobject release bug.
1575 config HAVE_DEBUG_BUGVERBOSE
1578 menu "Debug kernel data structures"
1581 bool "Debug linked list manipulation"
1582 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1584 Enable this to turn on extended checks in the linked-list
1590 bool "Debug priority linked list manipulation"
1591 depends on DEBUG_KERNEL
1593 Enable this to turn on extended checks in the priority-ordered
1594 linked-list (plist) walking routines. This checks the entire
1595 list multiple times during each manipulation.
1600 bool "Debug SG table operations"
1601 depends on DEBUG_KERNEL
1603 Enable this to turn on checks on scatter-gather tables. This can
1604 help find problems with drivers that do not properly initialize
1609 config DEBUG_NOTIFIERS
1610 bool "Debug notifier call chains"
1611 depends on DEBUG_KERNEL
1613 Enable this to turn on sanity checking for notifier call chains.
1614 This is most useful for kernel developers to make sure that
1615 modules properly unregister themselves from notifier chains.
1616 This is a relatively cheap check but if you care about maximum
1619 config BUG_ON_DATA_CORRUPTION
1620 bool "Trigger a BUG when data corruption is detected"
1623 Select this option if the kernel should BUG when it encounters
1624 data corruption in kernel memory structures when they get checked
1631 config DEBUG_CREDENTIALS
1632 bool "Debug credential management"
1633 depends on DEBUG_KERNEL
1635 Enable this to turn on some debug checking for credential
1636 management. The additional code keeps track of the number of
1637 pointers from task_structs to any given cred struct, and checks to
1638 see that this number never exceeds the usage count of the cred
1641 Furthermore, if SELinux is enabled, this also checks that the
1642 security pointer in the cred struct is never seen to be invalid.
1646 source "kernel/rcu/Kconfig.debug"
1648 config DEBUG_WQ_FORCE_RR_CPU
1649 bool "Force round-robin CPU selection for unbound work items"
1650 depends on DEBUG_KERNEL
1653 Workqueue used to implicitly guarantee that work items queued
1654 without explicit CPU specified are put on the local CPU. This
1655 guarantee is no longer true and while local CPU is still
1656 preferred work items may be put on foreign CPUs. Kernel
1657 parameter "workqueue.debug_force_rr_cpu" is added to force
1658 round-robin CPU selection to flush out usages which depend on the
1659 now broken guarantee. This config option enables the debug
1660 feature by default. When enabled, memory and cache locality will
1663 config DEBUG_BLOCK_EXT_DEVT
1664 bool "Force extended block device numbers and spread them"
1665 depends on DEBUG_KERNEL
1669 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1670 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1671 YOU ARE DOING. Distros, please enable this and fix whatever
1674 Conventionally, block device numbers are allocated from
1675 predetermined contiguous area. However, extended block area
1676 may introduce non-contiguous block device numbers. This
1677 option forces most block device numbers to be allocated from
1678 the extended space and spreads them to discover kernel or
1679 userland code paths which assume predetermined contiguous
1680 device number allocation.
1682 Note that turning on this debug option shuffles all the
1683 device numbers for all IDE and SCSI devices including libata
1684 ones, so root partition specified using device number
1685 directly (via rdev or root=MAJ:MIN) won't work anymore.
1686 Textual device names (root=/dev/sdXn) will continue to work.
1688 Say N if you are unsure.
1690 config CPU_HOTPLUG_STATE_CONTROL
1691 bool "Enable CPU hotplug state control"
1692 depends on DEBUG_KERNEL
1693 depends on HOTPLUG_CPU
1696 Allows to write steps between "offline" and "online" to the CPUs
1697 sysfs target file so states can be stepped granular. This is a debug
1698 option for now as the hotplug machinery cannot be stopped and
1699 restarted at arbitrary points yet.
1701 Say N if your are unsure.
1704 bool "Latency measuring infrastructure"
1705 depends on DEBUG_KERNEL
1706 depends on STACKTRACE_SUPPORT
1708 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1714 Enable this option if you want to use the LatencyTOP tool
1715 to find out which userspace is blocking on what kernel operations.
1717 source "kernel/trace/Kconfig"
1719 config PROVIDE_OHCI1394_DMA_INIT
1720 bool "Remote debugging over FireWire early on boot"
1721 depends on PCI && X86
1723 If you want to debug problems which hang or crash the kernel early
1724 on boot and the crashing machine has a FireWire port, you can use
1725 this feature to remotely access the memory of the crashed machine
1726 over FireWire. This employs remote DMA as part of the OHCI1394
1727 specification which is now the standard for FireWire controllers.
1729 With remote DMA, you can monitor the printk buffer remotely using
1730 firescope and access all memory below 4GB using fireproxy from gdb.
1731 Even controlling a kernel debugger is possible using remote DMA.
1735 If ohci1394_dma=early is used as boot parameter, it will initialize
1736 all OHCI1394 controllers which are found in the PCI config space.
1738 As all changes to the FireWire bus such as enabling and disabling
1739 devices cause a bus reset and thereby disable remote DMA for all
1740 devices, be sure to have the cable plugged and FireWire enabled on
1741 the debugging host before booting the debug target for debugging.
1743 This code (~1k) is freed after boot. By then, the firewire stack
1744 in charge of the OHCI-1394 controllers should be used instead.
1746 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1748 source "samples/Kconfig"
1750 config ARCH_HAS_DEVMEM_IS_ALLOWED
1753 config STRICT_DEVMEM
1754 bool "Filter access to /dev/mem"
1755 depends on MMU && DEVMEM
1756 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1757 default y if PPC || X86 || ARM64
1759 If this option is disabled, you allow userspace (root) access to all
1760 of memory, including kernel and userspace memory. Accidental
1761 access to this is obviously disastrous, but specific access can
1762 be used by people debugging the kernel. Note that with PAT support
1763 enabled, even in this case there are restrictions on /dev/mem
1764 use due to the cache aliasing requirements.
1766 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1767 file only allows userspace access to PCI space and the BIOS code and
1768 data regions. This is sufficient for dosemu and X and all common
1773 config IO_STRICT_DEVMEM
1774 bool "Filter I/O access to /dev/mem"
1775 depends on STRICT_DEVMEM
1777 If this option is disabled, you allow userspace (root) access to all
1778 io-memory regardless of whether a driver is actively using that
1779 range. Accidental access to this is obviously disastrous, but
1780 specific access can be used by people debugging kernel drivers.
1782 If this option is switched on, the /dev/mem file only allows
1783 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1784 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1785 if the driver using a given range cannot be disabled.
1789 menu "$(SRCARCH) Debugging"
1791 source "arch/$(SRCARCH)/Kconfig.debug"
1795 menu "Kernel Testing and Coverage"
1797 source "lib/kunit/Kconfig"
1799 config NOTIFIER_ERROR_INJECTION
1800 tristate "Notifier error injection"
1801 depends on DEBUG_KERNEL
1804 This option provides the ability to inject artificial errors to
1805 specified notifier chain callbacks. It is useful to test the error
1806 handling of notifier call chain failures.
1810 config PM_NOTIFIER_ERROR_INJECT
1811 tristate "PM notifier error injection module"
1812 depends on PM && NOTIFIER_ERROR_INJECTION
1813 default m if PM_DEBUG
1815 This option provides the ability to inject artificial errors to
1816 PM notifier chain callbacks. It is controlled through debugfs
1817 interface /sys/kernel/debug/notifier-error-inject/pm
1819 If the notifier call chain should be failed with some events
1820 notified, write the error code to "actions/<notifier event>/error".
1822 Example: Inject PM suspend error (-12 = -ENOMEM)
1824 # cd /sys/kernel/debug/notifier-error-inject/pm/
1825 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1826 # echo mem > /sys/power/state
1827 bash: echo: write error: Cannot allocate memory
1829 To compile this code as a module, choose M here: the module will
1830 be called pm-notifier-error-inject.
1834 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1835 tristate "OF reconfig notifier error injection module"
1836 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1838 This option provides the ability to inject artificial errors to
1839 OF reconfig notifier chain callbacks. It is controlled
1840 through debugfs interface under
1841 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1843 If the notifier call chain should be failed with some events
1844 notified, write the error code to "actions/<notifier event>/error".
1846 To compile this code as a module, choose M here: the module will
1847 be called of-reconfig-notifier-error-inject.
1851 config NETDEV_NOTIFIER_ERROR_INJECT
1852 tristate "Netdev notifier error injection module"
1853 depends on NET && NOTIFIER_ERROR_INJECTION
1855 This option provides the ability to inject artificial errors to
1856 netdevice notifier chain callbacks. It is controlled through debugfs
1857 interface /sys/kernel/debug/notifier-error-inject/netdev
1859 If the notifier call chain should be failed with some events
1860 notified, write the error code to "actions/<notifier event>/error".
1862 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1864 # cd /sys/kernel/debug/notifier-error-inject/netdev
1865 # echo -22 > actions/NETDEV_CHANGEMTU/error
1866 # ip link set eth0 mtu 1024
1867 RTNETLINK answers: Invalid argument
1869 To compile this code as a module, choose M here: the module will
1870 be called netdev-notifier-error-inject.
1874 config FUNCTION_ERROR_INJECTION
1876 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1878 config FAULT_INJECTION
1879 bool "Fault-injection framework"
1880 depends on DEBUG_KERNEL
1882 Provide fault-injection framework.
1883 For more details, see Documentation/fault-injection/.
1886 bool "Fault-injection capability for kmalloc"
1887 depends on FAULT_INJECTION
1888 depends on SLAB || SLUB
1890 Provide fault-injection capability for kmalloc.
1892 config FAIL_PAGE_ALLOC
1893 bool "Fault-injection capability for alloc_pages()"
1894 depends on FAULT_INJECTION
1896 Provide fault-injection capability for alloc_pages().
1898 config FAULT_INJECTION_USERCOPY
1899 bool "Fault injection capability for usercopy functions"
1900 depends on FAULT_INJECTION
1902 Provides fault-injection capability to inject failures
1903 in usercopy functions (copy_from_user(), get_user(), ...).
1905 config FAIL_MAKE_REQUEST
1906 bool "Fault-injection capability for disk IO"
1907 depends on FAULT_INJECTION && BLOCK
1909 Provide fault-injection capability for disk IO.
1911 config FAIL_IO_TIMEOUT
1912 bool "Fault-injection capability for faking disk interrupts"
1913 depends on FAULT_INJECTION && BLOCK
1915 Provide fault-injection capability on end IO handling. This
1916 will make the block layer "forget" an interrupt as configured,
1917 thus exercising the error handling.
1919 Only works with drivers that use the generic timeout handling,
1920 for others it wont do anything.
1923 bool "Fault-injection capability for futexes"
1925 depends on FAULT_INJECTION && FUTEX
1927 Provide fault-injection capability for futexes.
1929 config FAULT_INJECTION_DEBUG_FS
1930 bool "Debugfs entries for fault-injection capabilities"
1931 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1933 Enable configuration of fault-injection capabilities via debugfs.
1935 config FAIL_FUNCTION
1936 bool "Fault-injection capability for functions"
1937 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1939 Provide function-based fault-injection capability.
1940 This will allow you to override a specific function with a return
1941 with given return value. As a result, function caller will see
1942 an error value and have to handle it. This is useful to test the
1943 error handling in various subsystems.
1945 config FAIL_MMC_REQUEST
1946 bool "Fault-injection capability for MMC IO"
1947 depends on FAULT_INJECTION_DEBUG_FS && MMC
1949 Provide fault-injection capability for MMC IO.
1950 This will make the mmc core return data errors. This is
1951 useful to test the error handling in the mmc block device
1952 and to test how the mmc host driver handles retries from
1955 config FAULT_INJECTION_STACKTRACE_FILTER
1956 bool "stacktrace filter for fault-injection capabilities"
1957 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1960 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1962 Provide stacktrace filter for fault-injection capabilities
1964 config ARCH_HAS_KCOV
1967 An architecture should select this when it can successfully
1968 build and run with CONFIG_KCOV. This typically requires
1969 disabling instrumentation for some early boot code.
1971 config CC_HAS_SANCOV_TRACE_PC
1972 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1976 bool "Code coverage for fuzzing"
1977 depends on ARCH_HAS_KCOV
1978 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1980 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1982 KCOV exposes kernel code coverage information in a form suitable
1983 for coverage-guided fuzzing (randomized testing).
1985 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1986 different machines and across reboots. If you need stable PC values,
1987 disable RANDOMIZE_BASE.
1989 For more details, see Documentation/dev-tools/kcov.rst.
1991 config KCOV_ENABLE_COMPARISONS
1992 bool "Enable comparison operands collection by KCOV"
1994 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1996 KCOV also exposes operands of every comparison in the instrumented
1997 code along with operand sizes and PCs of the comparison instructions.
1998 These operands can be used by fuzzing engines to improve the quality
1999 of fuzzing coverage.
2001 config KCOV_INSTRUMENT_ALL
2002 bool "Instrument all code by default"
2006 If you are doing generic system call fuzzing (like e.g. syzkaller),
2007 then you will want to instrument the whole kernel and you should
2008 say y here. If you are doing more targeted fuzzing (like e.g.
2009 filesystem fuzzing with AFL) then you will want to enable coverage
2010 for more specific subsets of files, and should say n here.
2012 config KCOV_IRQ_AREA_SIZE
2013 hex "Size of interrupt coverage collection area in words"
2017 KCOV uses preallocated per-cpu areas to collect coverage from
2018 soft interrupts. This specifies the size of those areas in the
2019 number of unsigned long words.
2021 menuconfig RUNTIME_TESTING_MENU
2022 bool "Runtime Testing"
2025 if RUNTIME_TESTING_MENU
2028 tristate "Linux Kernel Dump Test Tool Module"
2031 This module enables testing of the different dumping mechanisms by
2032 inducing system failures at predefined crash points.
2033 If you don't need it: say N
2034 Choose M here to compile this code as a module. The module will be
2037 Documentation on how to use the module can be found in
2038 Documentation/fault-injection/provoke-crashes.rst
2040 config TEST_LIST_SORT
2041 tristate "Linked list sorting test"
2042 depends on DEBUG_KERNEL || m
2044 Enable this to turn on 'list_sort()' function test. This test is
2045 executed only once during system boot (so affects only boot time),
2046 or at module load time.
2050 config TEST_MIN_HEAP
2051 tristate "Min heap test"
2052 depends on DEBUG_KERNEL || m
2054 Enable this to turn on min heap function tests. This test is
2055 executed only once during system boot (so affects only boot time),
2056 or at module load time.
2061 tristate "Array-based sort test"
2062 depends on DEBUG_KERNEL || m
2064 This option enables the self-test function of 'sort()' at boot,
2065 or at module load time.
2069 config KPROBES_SANITY_TEST
2070 bool "Kprobes sanity tests"
2071 depends on DEBUG_KERNEL
2074 This option provides for testing basic kprobes functionality on
2075 boot. Samples of kprobe and kretprobe are inserted and
2076 verified for functionality.
2078 Say N if you are unsure.
2080 config BACKTRACE_SELF_TEST
2081 tristate "Self test for the backtrace code"
2082 depends on DEBUG_KERNEL
2084 This option provides a kernel module that can be used to test
2085 the kernel stack backtrace code. This option is not useful
2086 for distributions or general kernels, but only for kernel
2087 developers working on architecture code.
2089 Note that if you want to also test saved backtraces, you will
2090 have to enable STACKTRACE as well.
2092 Say N if you are unsure.
2095 tristate "Red-Black tree test"
2096 depends on DEBUG_KERNEL
2098 A benchmark measuring the performance of the rbtree library.
2099 Also includes rbtree invariant checks.
2101 config REED_SOLOMON_TEST
2102 tristate "Reed-Solomon library test"
2103 depends on DEBUG_KERNEL || m
2105 select REED_SOLOMON_ENC16
2106 select REED_SOLOMON_DEC16
2108 This option enables the self-test function of rslib at boot,
2109 or at module load time.
2113 config INTERVAL_TREE_TEST
2114 tristate "Interval tree test"
2115 depends on DEBUG_KERNEL
2116 select INTERVAL_TREE
2118 A benchmark measuring the performance of the interval tree library
2121 tristate "Per cpu operations test"
2122 depends on m && DEBUG_KERNEL
2124 Enable this option to build test module which validates per-cpu
2129 config ATOMIC64_SELFTEST
2130 tristate "Perform an atomic64_t self-test"
2132 Enable this option to test the atomic64_t functions at boot or
2133 at module load time.
2137 config ASYNC_RAID6_TEST
2138 tristate "Self test for hardware accelerated raid6 recovery"
2139 depends on ASYNC_RAID6_RECOV
2142 This is a one-shot self test that permutes through the
2143 recovery of all the possible two disk failure scenarios for a
2144 N-disk array. Recovery is performed with the asynchronous
2145 raid6 recovery routines, and will optionally use an offload
2146 engine if one is available.
2151 tristate "Test functions located in the hexdump module at runtime"
2153 config TEST_STRING_HELPERS
2154 tristate "Test functions located in the string_helpers module at runtime"
2157 tristate "Test strscpy*() family of functions at runtime"
2160 tristate "Test kstrto*() family of functions at runtime"
2163 tristate "Test printf() family of functions at runtime"
2166 tristate "Test bitmap_*() family of functions at runtime"
2168 Enable this option to test the bitmap functions at boot.
2173 tristate "Test functions located in the uuid module at runtime"
2176 tristate "Test the XArray code at runtime"
2178 config TEST_OVERFLOW
2179 tristate "Test check_*_overflow() functions at runtime"
2181 config TEST_RHASHTABLE
2182 tristate "Perform selftest on resizable hash table"
2184 Enable this option to test the rhashtable functions at boot.
2189 tristate "Perform selftest on hash functions"
2191 Enable this option to test the kernel's integer (<linux/hash.h>),
2192 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2193 hash functions on boot (or module load).
2195 This is intended to help people writing architecture-specific
2196 optimized versions. If unsure, say N.
2199 tristate "Perform selftest on IDA functions"
2202 tristate "Perform selftest on priority array manager"
2205 Enable this option to test priority array manager on boot
2210 config TEST_IRQ_TIMINGS
2211 bool "IRQ timings selftest"
2212 depends on IRQ_TIMINGS
2214 Enable this option to test the irq timings code on boot.
2219 tristate "Test module loading with 'hello world' module"
2222 This builds the "test_module" module that emits "Hello, world"
2223 on printk when loaded. It is designed to be used for basic
2224 evaluation of the module loading subsystem (for example when
2225 validating module verification). It lacks any extra dependencies,
2226 and will not normally be loaded by the system unless explicitly
2232 tristate "Test module for compilation of bitops operations"
2235 This builds the "test_bitops" module that is much like the
2236 TEST_LKM module except that it does a basic exercise of the
2237 set/clear_bit macros and get_count_order/long to make sure there are
2238 no compiler warnings from C=1 sparse checker or -Wextra
2239 compilations. It has no dependencies and doesn't run or load unless
2240 explicitly requested by name. for example: modprobe test_bitops.
2245 tristate "Test module for stress/performance analysis of vmalloc allocator"
2250 This builds the "test_vmalloc" module that should be used for
2251 stress and performance analysis. So, any new change for vmalloc
2252 subsystem can be evaluated from performance and stability point
2257 config TEST_USER_COPY
2258 tristate "Test user/kernel boundary protections"
2261 This builds the "test_user_copy" module that runs sanity checks
2262 on the copy_to/from_user infrastructure, making sure basic
2263 user/kernel boundary testing is working. If it fails to load,
2264 a regression has been detected in the user/kernel memory boundary
2270 tristate "Test BPF filter functionality"
2273 This builds the "test_bpf" module that runs various test vectors
2274 against the BPF interpreter or BPF JIT compiler depending on the
2275 current setting. This is in particular useful for BPF JIT compiler
2276 development, but also to run regression tests against changes in
2277 the interpreter code. It also enables test stubs for eBPF maps and
2278 verifier used by user space verifier testsuite.
2282 config TEST_BLACKHOLE_DEV
2283 tristate "Test blackhole netdev functionality"
2286 This builds the "test_blackhole_dev" module that validates the
2287 data path through this blackhole netdev.
2291 config FIND_BIT_BENCHMARK
2292 tristate "Test find_bit functions"
2294 This builds the "test_find_bit" module that measure find_*_bit()
2295 functions performance.
2299 config TEST_FIRMWARE
2300 tristate "Test firmware loading via userspace interface"
2301 depends on FW_LOADER
2303 This builds the "test_firmware" module that creates a userspace
2304 interface for testing firmware loading. This can be used to
2305 control the triggering of firmware loading without needing an
2306 actual firmware-using device. The contents can be rechecked by
2312 tristate "sysctl test driver"
2313 depends on PROC_SYSCTL
2315 This builds the "test_sysctl" module. This driver enables to test the
2316 proc sysctl interfaces available to drivers safely without affecting
2317 production knobs which might alter system functionality.
2321 config BITFIELD_KUNIT
2322 tristate "KUnit test bitfield functions at runtime"
2325 Enable this option to test the bitfield functions at boot.
2327 KUnit tests run during boot and output the results to the debug log
2328 in TAP format (http://testanything.org/). Only useful for kernel devs
2329 running the KUnit test harness, and not intended for inclusion into a
2332 For more information on KUnit and unit tests in general please refer
2333 to the KUnit documentation in Documentation/dev-tools/kunit/.
2337 config RESOURCE_KUNIT_TEST
2338 tristate "KUnit test for resource API"
2341 This builds the resource API unit test.
2342 Tests the logic of API provided by resource.c and ioport.h.
2343 For more information on KUnit and unit tests in general please refer
2344 to the KUnit documentation in Documentation/dev-tools/kunit/.
2348 config SYSCTL_KUNIT_TEST
2349 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2351 default KUNIT_ALL_TESTS
2353 This builds the proc sysctl unit test, which runs on boot.
2354 Tests the API contract and implementation correctness of sysctl.
2355 For more information on KUnit and unit tests in general please refer
2356 to the KUnit documentation in Documentation/dev-tools/kunit/.
2360 config LIST_KUNIT_TEST
2361 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2363 default KUNIT_ALL_TESTS
2365 This builds the linked list KUnit test suite.
2366 It tests that the API and basic functionality of the list_head type
2367 and associated macros.
2369 KUnit tests run during boot and output the results to the debug log
2370 in TAP format (https://testanything.org/). Only useful for kernel devs
2371 running the KUnit test harness, and not intended for inclusion into a
2374 For more information on KUnit and unit tests in general please refer
2375 to the KUnit documentation in Documentation/dev-tools/kunit/.
2379 config LINEAR_RANGES_TEST
2380 tristate "KUnit test for linear_ranges"
2382 select LINEAR_RANGES
2384 This builds the linear_ranges unit test, which runs on boot.
2385 Tests the linear_ranges logic correctness.
2386 For more information on KUnit and unit tests in general please refer
2387 to the KUnit documentation in Documentation/dev-tools/kunit/.
2391 config CMDLINE_KUNIT_TEST
2392 tristate "KUnit test for cmdline API"
2395 This builds the cmdline API unit test.
2396 Tests the logic of API provided by cmdline.c.
2397 For more information on KUnit and unit tests in general please refer
2398 to the KUnit documentation in Documentation/dev-tools/kunit/.
2403 tristate "KUnit test for bits.h"
2406 This builds the bits unit test.
2407 Tests the logic of macros defined in bits.h.
2408 For more information on KUnit and unit tests in general please refer
2409 to the KUnit documentation in Documentation/dev-tools/kunit/.
2414 tristate "udelay test driver"
2416 This builds the "udelay_test" module that helps to make sure
2417 that udelay() is working properly.
2421 config TEST_STATIC_KEYS
2422 tristate "Test static keys"
2425 Test the static key interfaces.
2430 tristate "kmod stress tester"
2432 depends on NETDEVICES && NET_CORE && INET # for TUN
2439 Test the kernel's module loading mechanism: kmod. kmod implements
2440 support to load modules using the Linux kernel's usermode helper.
2441 This test provides a series of tests against kmod.
2443 Although technically you can either build test_kmod as a module or
2444 into the kernel we disallow building it into the kernel since
2445 it stress tests request_module() and this will very likely cause
2446 some issues by taking over precious threads available from other
2447 module load requests, ultimately this could be fatal.
2451 tools/testing/selftests/kmod/kmod.sh --help
2455 config TEST_DEBUG_VIRTUAL
2456 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2457 depends on DEBUG_VIRTUAL
2459 Test the kernel's ability to detect incorrect calls to
2460 virt_to_phys() done against the non-linear part of the
2461 kernel's virtual address map.
2465 config TEST_MEMCAT_P
2466 tristate "Test memcat_p() helper function"
2468 Test the memcat_p() helper for correctly merging two
2469 pointer arrays together.
2473 config TEST_LIVEPATCH
2474 tristate "Test livepatching"
2476 depends on DYNAMIC_DEBUG
2477 depends on LIVEPATCH
2480 Test kernel livepatching features for correctness. The tests will
2481 load test modules that will be livepatched in various scenarios.
2483 To run all the livepatching tests:
2485 make -C tools/testing/selftests TARGETS=livepatch run_tests
2487 Alternatively, individual tests may be invoked:
2489 tools/testing/selftests/livepatch/test-callbacks.sh
2490 tools/testing/selftests/livepatch/test-livepatch.sh
2491 tools/testing/selftests/livepatch/test-shadow-vars.sh
2496 tristate "Perform selftest on object aggreration manager"
2500 Enable this option to test object aggregation manager on boot
2504 config TEST_STACKINIT
2505 tristate "Test level of stack variable initialization"
2507 Test if the kernel is zero-initializing stack variables and
2508 padding. Coverage is controlled by compiler flags,
2509 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2510 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2515 tristate "Test heap/page initialization"
2517 Test if the kernel is zero-initializing heap and page allocations.
2518 This can be useful to test init_on_alloc and init_on_free features.
2523 tristate "Test HMM (Heterogeneous Memory Management)"
2524 depends on TRANSPARENT_HUGEPAGE
2525 depends on DEVICE_PRIVATE
2529 This is a pseudo device driver solely for testing HMM.
2530 Say M here if you want to build the HMM test module.
2531 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2535 config TEST_FREE_PAGES
2536 tristate "Test freeing pages"
2538 Test that a memory leak does not occur due to a race between
2539 freeing a block of pages and a speculative page reference.
2540 Loading this module is safe if your kernel has the bug fixed.
2541 If the bug is not fixed, it will leak gigabytes of memory and
2542 probably OOM your system.
2545 tristate "Test floating point operations in kernel space"
2546 depends on X86 && !KCOV_INSTRUMENT_ALL
2548 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2549 which will trigger a sequence of floating point operations. This is used
2550 for self-testing floating point control register setting in
2555 endif # RUNTIME_TESTING_MENU
2560 This option adds a kernel parameter 'memtest', which allows memtest
2562 memtest=0, mean disabled; -- default
2563 memtest=1, mean do 1 test pattern;
2565 memtest=17, mean do 17 test patterns.
2566 If you are unsure how to answer this question, answer N.
2570 config HYPERV_TESTING
2571 bool "Microsoft Hyper-V driver testing"
2573 depends on HYPERV && DEBUG_FS
2575 Select this option to enable Hyper-V vmbus testing.
2577 endmenu # "Kernel Testing and Coverage"
2579 source "Documentation/Kconfig"
2581 endmenu # Kernel hacking
projects / linux-2.6-microblaze.git / blob