1 # SPDX-License-Identifier: GPL-2.0-only
4 menu "printk and dmesg options"
7 bool "Show timing information on printks"
10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
22 bool "Show caller information on printks"
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
38 config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
49 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
54 Default loglevel to determine what will be printed on the console.
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
60 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
64 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
69 loglevel to use when "quiet" is passed on the kernel commandline.
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
75 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)"
80 Default log level for printk statements with no specified priority.
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
90 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
109 bool "Enable dynamic printk() support"
112 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
138 filename:lineno [module]function flags format
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
180 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
183 depends on (DEBUG_FS || PROC_FS)
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
191 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
200 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
209 endmenu # "printk and dmesg options"
212 bool "Kernel debugging"
214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems.
218 bool "Miscellaneous debug code"
220 depends on DEBUG_KERNEL
222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug option but isn't.
225 menu "Compile-time checks and compiler options"
230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice below, indicating that debug
232 information will be generated for build targets.
234 # Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
235 # some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
236 config AS_HAS_NON_CONST_LEB128
237 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
240 prompt "Debug information"
241 depends on DEBUG_KERNEL
243 Selecting something other than "None" results in a kernel image
244 that will include debugging info resulting in a larger kernel image.
245 This adds debug symbols to the kernel and modules (gcc -g), and
246 is needed if you intend to use kernel crashdump or binary object
247 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
249 Choose which version of DWARF debug info to emit. If unsure,
250 select "Toolchain default".
252 config DEBUG_INFO_NONE
253 bool "Disable debug information"
255 Do not build the kernel with debugging information, which will
256 result in a faster and smaller build.
258 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
259 bool "Rely on the toolchain's implicit default DWARF version"
261 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
263 The implicit default version of DWARF debug info produced by a
264 toolchain changes over time.
266 This can break consumers of the debug info that haven't upgraded to
267 support newer revisions, and prevent testing newer versions, but
268 those should be less common scenarios.
270 config DEBUG_INFO_DWARF4
271 bool "Generate DWARF Version 4 debuginfo"
273 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
275 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
276 if using clang without clang's integrated assembler, and gdb 7.0+.
278 If you have consumers of DWARF debug info that are not ready for
279 newer revisions of DWARF, you may wish to choose this or have your
282 config DEBUG_INFO_DWARF5
283 bool "Generate DWARF Version 5 debuginfo"
285 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
287 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
288 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
289 draft features until 7.0), and gdb 8.0+.
291 Changes to the structure of debug info in Version 5 allow for around
292 15-18% savings in resulting image and debug info section sizes as
293 compared to DWARF Version 4. DWARF Version 5 standardizes previous
294 extensions such as accelerators for symbol indexing and the format
295 for fission (.dwo/.dwp) files. Users may not want to select this
296 config if they rely on tooling that has not yet been updated to
297 support DWARF Version 5.
299 endchoice # "Debug information"
303 config DEBUG_INFO_REDUCED
304 bool "Reduce debugging information"
306 If you say Y here gcc is instructed to generate less debugging
307 information for structure types. This means that tools that
308 need full debugging information (like kgdb or systemtap) won't
309 be happy. But if you merely need debugging information to
310 resolve line numbers there is no loss. Advantage is that
311 build directory object sizes shrink dramatically over a full
312 DEBUG_INFO build and compile times are reduced too.
313 Only works with newer gcc versions.
316 prompt "Compressed Debug information"
318 Compress the resulting debug info. Results in smaller debug info sections,
319 but requires that consumers are able to decompress the results.
321 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
323 config DEBUG_INFO_COMPRESSED_NONE
324 bool "Don't compress debug information"
326 Don't compress debug info sections.
328 config DEBUG_INFO_COMPRESSED_ZLIB
329 bool "Compress debugging information with zlib"
330 depends on $(cc-option,-gz=zlib)
331 depends on $(ld-option,--compress-debug-sections=zlib)
333 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
334 5.0+, binutils 2.26+, and zlib.
336 Users of dpkg-deb via scripts/package/builddeb may find an increase in
337 size of their debug .deb packages with this config set, due to the
338 debug info being compressed with zlib, then the object files being
339 recompressed with a different compression scheme. But this is still
340 preferable to setting $KDEB_COMPRESS to "none" which would be even
343 config DEBUG_INFO_COMPRESSED_ZSTD
344 bool "Compress debugging information with zstd"
345 depends on $(cc-option,-gz=zstd)
346 depends on $(ld-option,--compress-debug-sections=zstd)
348 Compress the debug information using zstd. This may provide better
349 compression than zlib, for about the same time costs, but requires newer
350 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
353 endchoice # "Compressed Debug information"
355 config DEBUG_INFO_SPLIT
356 bool "Produce split debuginfo in .dwo files"
357 depends on $(cc-option,-gsplit-dwarf)
358 # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
360 # https://github.com/llvm/llvm-project/issues/56642
361 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
362 depends on !RISCV || GCC_VERSION >= 120000
364 Generate debug info into separate .dwo files. This significantly
365 reduces the build directory size for builds with DEBUG_INFO,
366 because it stores the information only once on disk in .dwo
367 files instead of multiple times in object files and executables.
368 In addition the debug information is also compressed.
370 Requires recent gcc (4.7+) and recent gdb/binutils.
371 Any tool that packages or reads debug information would need
372 to know about the .dwo files and include them.
373 Incompatible with older versions of ccache.
375 config DEBUG_INFO_BTF
376 bool "Generate BTF typeinfo"
377 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
378 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
379 depends on BPF_SYSCALL
380 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
382 Generate deduplicated BTF type information from DWARF debug info.
383 Turning this on expects presence of pahole tool, which will convert
384 DWARF type info into equivalent deduplicated BTF type info.
386 config PAHOLE_HAS_SPLIT_BTF
387 def_bool PAHOLE_VERSION >= 119
389 config PAHOLE_HAS_BTF_TAG
390 def_bool PAHOLE_VERSION >= 123
391 depends on CC_IS_CLANG
393 Decide whether pahole emits btf_tag attributes (btf_type_tag and
394 btf_decl_tag) or not. Currently only clang compiler implements
395 these attributes, so make the config depend on CC_IS_CLANG.
397 config PAHOLE_HAS_LANG_EXCLUDE
398 def_bool PAHOLE_VERSION >= 124
400 Support for the --lang_exclude flag which makes pahole exclude
401 compilation units from the supplied language. Used in Kbuild to
402 omit Rust CUs which are not supported in version 1.24 of pahole,
403 otherwise it would emit malformed kernel and module binaries when
404 using DEBUG_INFO_BTF_MODULES.
406 config DEBUG_INFO_BTF_MODULES
408 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
410 Generate compact split BTF type information for kernel modules.
412 config MODULE_ALLOW_BTF_MISMATCH
413 bool "Allow loading modules with non-matching BTF type info"
414 depends on DEBUG_INFO_BTF_MODULES
416 For modules whose split BTF does not match vmlinux, load without
417 BTF rather than refusing to load. The default behavior with
418 module BTF enabled is to reject modules with such mismatches;
419 this option will still load module BTF where possible but ignore
420 it when a mismatch is found.
423 bool "Provide GDB scripts for kernel debugging"
425 This creates the required links to GDB helper scripts in the
426 build directory. If you load vmlinux into gdb, the helper
427 scripts will be automatically imported by gdb as well, and
428 additional functions are available to analyze a Linux kernel
429 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 int "Warn for stack frames larger than"
438 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
439 default 2048 if PARISC
440 default 1536 if (!64BIT && XTENSA)
441 default 1280 if KASAN && !64BIT
442 default 1024 if !64BIT
443 default 2048 if 64BIT
445 Tell the compiler to warn at build time for stack frames larger than this.
446 Setting this too low will cause a lot of warnings.
447 Setting it to 0 disables the warning.
449 config STRIP_ASM_SYMS
450 bool "Strip assembler-generated symbols during link"
453 Strip internal assembler-generated symbols during a link (symbols
454 that look like '.Lxxx') so they don't pollute the output of
455 get_wchan() and suchlike.
458 bool "Generate readable assembler code"
459 depends on DEBUG_KERNEL
462 Disable some compiler optimizations that tend to generate human unreadable
463 assembler output. This may make the kernel slightly slower, but it helps
464 to keep kernel developers who have to stare a lot at assembler listings
467 config HEADERS_INSTALL
468 bool "Install uapi headers to usr/include"
471 This option will install uapi headers (headers exported to user-space)
472 into the usr/include directory for use during the kernel build.
473 This is unneeded for building the kernel itself, but needed for some
474 user-space program samples. It is also needed by some features such
475 as uapi header sanity checks.
477 config DEBUG_SECTION_MISMATCH
478 bool "Enable full Section mismatch analysis"
481 The section mismatch analysis checks if there are illegal
482 references from one section to another section.
483 During linktime or runtime, some sections are dropped;
484 any use of code/data previously in these sections would
485 most likely result in an oops.
486 In the code, functions and variables are annotated with
487 __init,, etc. (see the full list in include/linux/init.h),
488 which results in the code/data being placed in specific sections.
489 The section mismatch analysis is always performed after a full
490 kernel build, and enabling this option causes the following
491 additional step to occur:
492 - Add the option -fno-inline-functions-called-once to gcc commands.
493 When inlining a function annotated with __init in a non-init
494 function, we would lose the section information and thus
495 the analysis would not catch the illegal reference.
496 This option tells gcc to inline less (but it does result in
499 config SECTION_MISMATCH_WARN_ONLY
500 bool "Make section mismatch errors non-fatal"
503 If you say N here, the build process will fail if there are any
504 section mismatch, instead of just throwing warnings.
508 config DEBUG_FORCE_FUNCTION_ALIGN_64B
509 bool "Force all function address 64B aligned"
510 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
511 select FUNCTION_ALIGNMENT_64B
513 There are cases that a commit from one domain changes the function
514 address alignment of other domains, and cause magic performance
515 bump (regression or improvement). Enable this option will help to
516 verify if the bump is caused by function alignment changes, while
517 it will slightly increase the kernel size and affect icache usage.
519 It is mainly for debug and performance tuning use.
522 # Select this config option from the architecture Kconfig, if it
523 # is preferred to always offer frame pointers as a config
524 # option on the architecture (regardless of KERNEL_DEBUG):
526 config ARCH_WANT_FRAME_POINTERS
530 bool "Compile the kernel with frame pointers"
531 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
532 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
534 If you say Y here the resulting kernel image will be slightly
535 larger and slower, but it gives very useful debugging information
536 in case of kernel bugs. (precise oopses/stacktraces/warnings)
541 config STACK_VALIDATION
542 bool "Compile-time stack metadata validation"
543 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
547 Validate frame pointer rules at compile-time. This helps ensure that
548 runtime stack traces are more reliable.
550 For more information, see
551 tools/objtool/Documentation/objtool.txt.
553 config NOINSTR_VALIDATION
555 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
560 bool "Generate vmlinux.map file when linking"
563 Selecting this option will pass "-Map=vmlinux.map" to ld
564 when linking vmlinux. That file can be useful for verifying
565 and debugging magic section games, and for seeing which
566 pieces of code get eliminated with
567 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
569 config DEBUG_FORCE_WEAK_PER_CPU
570 bool "Force weak per-cpu definitions"
571 depends on DEBUG_KERNEL
573 s390 and alpha require percpu variables in modules to be
574 defined weak to work around addressing range issue which
575 puts the following two restrictions on percpu variable
578 1. percpu symbols must be unique whether static or not
579 2. percpu variables can't be defined inside a function
581 To ensure that generic code follows the above rules, this
582 option forces all percpu variables to be defined as weak.
584 endmenu # "Compiler options"
586 menu "Generic Kernel Debugging Instruments"
589 bool "Magic SysRq key"
592 If you say Y here, you will have some control over the system even
593 if the system crashes for example during kernel debugging (e.g., you
594 will be able to flush the buffer cache to disk, reboot the system
595 immediately or dump some status information). This is accomplished
596 by pressing various keys while holding SysRq (Alt+PrintScreen). It
597 also works on a serial console (on PC hardware at least), if you
598 send a BREAK and then within 5 seconds a command keypress. The
599 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
600 Don't say Y unless you really know what this hack does.
602 config MAGIC_SYSRQ_DEFAULT_ENABLE
603 hex "Enable magic SysRq key functions by default"
604 depends on MAGIC_SYSRQ
607 Specifies which SysRq key functions are enabled by default.
608 This may be set to 1 or 0 to enable or disable them all, or
609 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
611 config MAGIC_SYSRQ_SERIAL
612 bool "Enable magic SysRq key over serial"
613 depends on MAGIC_SYSRQ
616 Many embedded boards have a disconnected TTL level serial which can
617 generate some garbage that can lead to spurious false sysrq detects.
618 This option allows you to decide whether you want to enable the
621 config MAGIC_SYSRQ_SERIAL_SEQUENCE
622 string "Char sequence that enables magic SysRq over serial"
623 depends on MAGIC_SYSRQ_SERIAL
626 Specifies a sequence of characters that can follow BREAK to enable
627 SysRq on a serial console.
629 If unsure, leave an empty string and the option will not be enabled.
632 bool "Debug Filesystem"
634 debugfs is a virtual file system that kernel developers use to put
635 debugging files into. Enable this option to be able to read and
636 write to these files.
638 For detailed documentation on the debugfs API, see
639 Documentation/filesystems/.
644 prompt "Debugfs default access"
646 default DEBUG_FS_ALLOW_ALL
648 This selects the default access restrictions for debugfs.
649 It can be overridden with kernel command line option
650 debugfs=[on,no-mount,off]. The restrictions apply for API access
651 and filesystem registration.
653 config DEBUG_FS_ALLOW_ALL
656 No restrictions apply. Both API and filesystem registration
657 is on. This is the normal default operation.
659 config DEBUG_FS_DISALLOW_MOUNT
660 bool "Do not register debugfs as filesystem"
662 The API is open but filesystem is not loaded. Clients can still do
663 their work and read with debug tools that do not need
666 config DEBUG_FS_ALLOW_NONE
669 Access is off. Clients get -PERM when trying to create nodes in
670 debugfs tree and debugfs is not registered as a filesystem.
671 Client can then back-off or continue without debugfs access.
675 source "lib/Kconfig.kgdb"
676 source "lib/Kconfig.ubsan"
677 source "lib/Kconfig.kcsan"
681 menu "Networking Debugging"
683 source "net/Kconfig.debug"
685 endmenu # "Networking Debugging"
687 menu "Memory Debugging"
689 source "mm/Kconfig.debug"
692 bool "Debug object operations"
693 depends on DEBUG_KERNEL
695 If you say Y here, additional code will be inserted into the
696 kernel to track the life time of various objects and validate
697 the operations on those objects.
699 config DEBUG_OBJECTS_SELFTEST
700 bool "Debug objects selftest"
701 depends on DEBUG_OBJECTS
703 This enables the selftest of the object debug code.
705 config DEBUG_OBJECTS_FREE
706 bool "Debug objects in freed memory"
707 depends on DEBUG_OBJECTS
709 This enables checks whether a k/v free operation frees an area
710 which contains an object which has not been deactivated
711 properly. This can make kmalloc/kfree-intensive workloads
714 config DEBUG_OBJECTS_TIMERS
715 bool "Debug timer objects"
716 depends on DEBUG_OBJECTS
718 If you say Y here, additional code will be inserted into the
719 timer routines to track the life time of timer objects and
720 validate the timer operations.
722 config DEBUG_OBJECTS_WORK
723 bool "Debug work objects"
724 depends on DEBUG_OBJECTS
726 If you say Y here, additional code will be inserted into the
727 work queue routines to track the life time of work objects and
728 validate the work operations.
730 config DEBUG_OBJECTS_RCU_HEAD
731 bool "Debug RCU callbacks objects"
732 depends on DEBUG_OBJECTS
734 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
736 config DEBUG_OBJECTS_PERCPU_COUNTER
737 bool "Debug percpu counter objects"
738 depends on DEBUG_OBJECTS
740 If you say Y here, additional code will be inserted into the
741 percpu counter routines to track the life time of percpu counter
742 objects and validate the percpu counter operations.
744 config DEBUG_OBJECTS_ENABLE_DEFAULT
745 int "debug_objects bootup default value (0-1)"
748 depends on DEBUG_OBJECTS
750 Debug objects boot parameter default value
752 config SHRINKER_DEBUG
753 bool "Enable shrinker debugging support"
756 Say Y to enable the shrinker debugfs interface which provides
757 visibility into the kernel memory shrinkers subsystem.
758 Disable it to avoid an extra memory footprint.
760 config DEBUG_STACK_USAGE
761 bool "Stack utilization instrumentation"
762 depends on DEBUG_KERNEL
764 Enables the display of the minimum amount of free stack which each
765 task has ever had available in the sysrq-T and sysrq-P debug output.
767 This option will slow down process creation somewhat.
769 config SCHED_STACK_END_CHECK
770 bool "Detect stack corruption on calls to schedule()"
771 depends on DEBUG_KERNEL
774 This option checks for a stack overrun on calls to schedule().
775 If the stack end location is found to be over written always panic as
776 the content of the corrupted region can no longer be trusted.
777 This is to ensure no erroneous behaviour occurs which could result in
778 data corruption or a sporadic crash at a later stage once the region
779 is examined. The runtime overhead introduced is minimal.
781 config ARCH_HAS_DEBUG_VM_PGTABLE
784 An architecture should select this when it can successfully
785 build and run DEBUG_VM_PGTABLE.
787 config DEBUG_VM_IRQSOFF
788 def_bool DEBUG_VM && !PREEMPT_RT
792 depends on DEBUG_KERNEL
794 Enable this to turn on extended checks in the virtual-memory system
795 that may impact performance.
799 config DEBUG_VM_SHOOT_LAZIES
800 bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
802 depends on MMU_LAZY_TLB_SHOOTDOWN
804 Enable additional IPIs that ensure lazy tlb mm references are removed
805 before the mm is freed.
809 config DEBUG_VM_MAPLE_TREE
810 bool "Debug VM maple trees"
812 select DEBUG_MAPLE_TREE
814 Enable VM maple tree debugging information and extra validations.
819 bool "Debug VM red-black trees"
822 Enable VM red-black tree debugging information and extra validations.
826 config DEBUG_VM_PGFLAGS
827 bool "Debug page-flags operations"
830 Enables extra validation on page flags operations.
834 config DEBUG_VM_PGTABLE
835 bool "Debug arch page table for semantics compliance"
837 depends on ARCH_HAS_DEBUG_VM_PGTABLE
838 default y if DEBUG_VM
840 This option provides a debug method which can be used to test
841 architecture page table helper functions on various platforms in
842 verifying if they comply with expected generic MM semantics. This
843 will help architecture code in making sure that any changes or
844 new additions of these helpers still conform to expected
845 semantics of the generic MM. Platforms will have to opt in for
846 this through ARCH_HAS_DEBUG_VM_PGTABLE.
850 config ARCH_HAS_DEBUG_VIRTUAL
854 bool "Debug VM translations"
855 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
857 Enable some costly sanity checks in virtual to page code. This can
858 catch mistakes with virt_to_page() and friends.
862 config DEBUG_NOMMU_REGIONS
863 bool "Debug the global anon/private NOMMU mapping region tree"
864 depends on DEBUG_KERNEL && !MMU
866 This option causes the global tree of anonymous and private mapping
867 regions to be regularly checked for invalid topology.
869 config DEBUG_MEMORY_INIT
870 bool "Debug memory initialisation" if EXPERT
873 Enable this for additional checks during memory initialisation.
874 The sanity checks verify aspects of the VM such as the memory model
875 and other information provided by the architecture. Verbose
876 information will be printed at KERN_DEBUG loglevel depending
877 on the mminit_loglevel= command-line option.
881 config MEMORY_NOTIFIER_ERROR_INJECT
882 tristate "Memory hotplug notifier error injection module"
883 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
885 This option provides the ability to inject artificial errors to
886 memory hotplug notifier chain callbacks. It is controlled through
887 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
889 If the notifier call chain should be failed with some events
890 notified, write the error code to "actions/<notifier event>/error".
892 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
894 # cd /sys/kernel/debug/notifier-error-inject/memory
895 # echo -12 > actions/MEM_GOING_OFFLINE/error
896 # echo offline > /sys/devices/system/memory/memoryXXX/state
897 bash: echo: write error: Cannot allocate memory
899 To compile this code as a module, choose M here: the module will
900 be called memory-notifier-error-inject.
904 config DEBUG_PER_CPU_MAPS
905 bool "Debug access to per_cpu maps"
906 depends on DEBUG_KERNEL
909 Say Y to verify that the per_cpu map being accessed has
910 been set up. This adds a fair amount of code to kernel memory
911 and decreases performance.
915 config DEBUG_KMAP_LOCAL
916 bool "Debug kmap_local temporary mappings"
917 depends on DEBUG_KERNEL && KMAP_LOCAL
919 This option enables additional error checking for the kmap_local
920 infrastructure. Disable for production use.
922 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
925 config DEBUG_KMAP_LOCAL_FORCE_MAP
926 bool "Enforce kmap_local temporary mappings"
927 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
929 select DEBUG_KMAP_LOCAL
931 This option enforces temporary mappings through the kmap_local
932 mechanism for non-highmem pages and on non-highmem systems.
933 Disable this for production systems!
936 bool "Highmem debugging"
937 depends on DEBUG_KERNEL && HIGHMEM
938 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
939 select DEBUG_KMAP_LOCAL
941 This option enables additional error checking for high memory
942 systems. Disable for production systems.
944 config HAVE_DEBUG_STACKOVERFLOW
947 config DEBUG_STACKOVERFLOW
948 bool "Check for stack overflows"
949 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
951 Say Y here if you want to check for overflows of kernel, IRQ
952 and exception stacks (if your architecture uses them). This
953 option will show detailed messages if free stack space drops
954 below a certain limit.
956 These kinds of bugs usually occur when call-chains in the
957 kernel get too deep, especially when interrupts are
960 Use this in cases where you see apparently random memory
961 corruption, especially if it appears in 'struct thread_info'
963 If in doubt, say "N".
965 source "lib/Kconfig.kasan"
966 source "lib/Kconfig.kfence"
967 source "lib/Kconfig.kmsan"
969 endmenu # "Memory Debugging"
972 bool "Debug shared IRQ handlers"
973 depends on DEBUG_KERNEL
975 Enable this to generate a spurious interrupt just before a shared
976 interrupt handler is deregistered (generating one when registering
977 is currently disabled). Drivers need to handle this correctly. Some
978 don't and need to be caught.
980 menu "Debug Oops, Lockups and Hangs"
985 Say Y here to enable the kernel to panic when it oopses. This
986 has the same effect as setting oops=panic on the kernel command
989 This feature is useful to ensure that the kernel does not do
990 anything erroneous after an oops which could result in data
991 corruption or other issues.
995 config PANIC_ON_OOPS_VALUE
998 default 0 if !PANIC_ON_OOPS
999 default 1 if PANIC_ON_OOPS
1001 config PANIC_TIMEOUT
1005 Set the timeout value (in seconds) until a reboot occurs when
1006 the kernel panics. If n = 0, then we wait forever. A timeout
1007 value n > 0 will wait n seconds before rebooting, while a timeout
1008 value n < 0 will reboot immediately.
1010 config LOCKUP_DETECTOR
1013 config SOFTLOCKUP_DETECTOR
1014 bool "Detect Soft Lockups"
1015 depends on DEBUG_KERNEL && !S390
1016 select LOCKUP_DETECTOR
1018 Say Y here to enable the kernel to act as a watchdog to detect
1021 Softlockups are bugs that cause the kernel to loop in kernel
1022 mode for more than 20 seconds, without giving other tasks a
1023 chance to run. The current stack trace is displayed upon
1024 detection and the system will stay locked up.
1026 config BOOTPARAM_SOFTLOCKUP_PANIC
1027 bool "Panic (Reboot) On Soft Lockups"
1028 depends on SOFTLOCKUP_DETECTOR
1030 Say Y here to enable the kernel to panic on "soft lockups",
1031 which are bugs that cause the kernel to loop in kernel
1032 mode for more than 20 seconds (configurable using the watchdog_thresh
1033 sysctl), without giving other tasks a chance to run.
1035 The panic can be used in combination with panic_timeout,
1036 to cause the system to reboot automatically after a
1037 lockup has been detected. This feature is useful for
1038 high-availability systems that have uptime guarantees and
1039 where a lockup must be resolved ASAP.
1043 config HAVE_HARDLOCKUP_DETECTOR_BUDDY
1049 # Global switch whether to build a hardlockup detector at all. It is available
1050 # only when the architecture supports at least one implementation. There are
1051 # two exceptions. The hardlockup detector is never enabled on:
1053 # s390: it reported many false positives there
1055 # sparc64: has a custom implementation which is not using the common
1056 # hardlockup command line options and sysctl interface.
1058 config HARDLOCKUP_DETECTOR
1059 bool "Detect Hard Lockups"
1060 depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
1061 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1062 imply HARDLOCKUP_DETECTOR_PERF
1063 imply HARDLOCKUP_DETECTOR_BUDDY
1064 imply HARDLOCKUP_DETECTOR_ARCH
1065 select LOCKUP_DETECTOR
1068 Say Y here to enable the kernel to act as a watchdog to detect
1071 Hardlockups are bugs that cause the CPU to loop in kernel mode
1072 for more than 10 seconds, without letting other interrupts have a
1073 chance to run. The current stack trace is displayed upon detection
1074 and the system will stay locked up.
1077 # Note that arch-specific variants are always preferred.
1079 config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1080 bool "Prefer the buddy CPU hardlockup detector"
1081 depends on HARDLOCKUP_DETECTOR
1082 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
1083 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1085 Say Y here to prefer the buddy hardlockup detector over the perf one.
1087 With the buddy detector, each CPU uses its softlockup hrtimer
1088 to check that the next CPU is processing hrtimer interrupts by
1089 verifying that a counter is increasing.
1091 This hardlockup detector is useful on systems that don't have
1092 an arch-specific hardlockup detector or if resources needed
1093 for the hardlockup detector are better used for other things.
1095 config HARDLOCKUP_DETECTOR_PERF
1097 depends on HARDLOCKUP_DETECTOR
1098 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
1099 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1100 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1102 config HARDLOCKUP_DETECTOR_BUDDY
1104 depends on HARDLOCKUP_DETECTOR
1105 depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1106 depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
1107 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1108 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1110 config HARDLOCKUP_DETECTOR_ARCH
1112 depends on HARDLOCKUP_DETECTOR
1113 depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1115 The arch-specific implementation of the hardlockup detector will
1119 # Both the "perf" and "buddy" hardlockup detectors count hrtimer
1120 # interrupts. This config enables functions managing this common code.
1122 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1124 select SOFTLOCKUP_DETECTOR
1127 # Enables a timestamp based low pass filter to compensate for perf based
1128 # hard lockup detection which runs too fast due to turbo modes.
1130 config HARDLOCKUP_CHECK_TIMESTAMP
1133 config BOOTPARAM_HARDLOCKUP_PANIC
1134 bool "Panic (Reboot) On Hard Lockups"
1135 depends on HARDLOCKUP_DETECTOR
1137 Say Y here to enable the kernel to panic on "hard lockups",
1138 which are bugs that cause the kernel to loop in kernel
1139 mode with interrupts disabled for more than 10 seconds (configurable
1140 using the watchdog_thresh sysctl).
1144 config DETECT_HUNG_TASK
1145 bool "Detect Hung Tasks"
1146 depends on DEBUG_KERNEL
1147 default SOFTLOCKUP_DETECTOR
1149 Say Y here to enable the kernel to detect "hung tasks",
1150 which are bugs that cause the task to be stuck in
1151 uninterruptible "D" state indefinitely.
1153 When a hung task is detected, the kernel will print the
1154 current stack trace (which you should report), but the
1155 task will stay in uninterruptible state. If lockdep is
1156 enabled then all held locks will also be reported. This
1157 feature has negligible overhead.
1159 config DEFAULT_HUNG_TASK_TIMEOUT
1160 int "Default timeout for hung task detection (in seconds)"
1161 depends on DETECT_HUNG_TASK
1164 This option controls the default timeout (in seconds) used
1165 to determine when a task has become non-responsive and should
1168 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1169 sysctl or by writing a value to
1170 /proc/sys/kernel/hung_task_timeout_secs.
1172 A timeout of 0 disables the check. The default is two minutes.
1173 Keeping the default should be fine in most cases.
1175 config BOOTPARAM_HUNG_TASK_PANIC
1176 bool "Panic (Reboot) On Hung Tasks"
1177 depends on DETECT_HUNG_TASK
1179 Say Y here to enable the kernel to panic on "hung tasks",
1180 which are bugs that cause the kernel to leave a task stuck
1181 in uninterruptible "D" state.
1183 The panic can be used in combination with panic_timeout,
1184 to cause the system to reboot automatically after a
1185 hung task has been detected. This feature is useful for
1186 high-availability systems that have uptime guarantees and
1187 where a hung tasks must be resolved ASAP.
1192 bool "Detect Workqueue Stalls"
1193 depends on DEBUG_KERNEL
1195 Say Y here to enable stall detection on workqueues. If a
1196 worker pool doesn't make forward progress on a pending work
1197 item for over a given amount of time, 30s by default, a
1198 warning message is printed along with dump of workqueue
1199 state. This can be configured through kernel parameter
1200 "workqueue.watchdog_thresh" and its sysfs counterpart.
1202 config WQ_CPU_INTENSIVE_REPORT
1203 bool "Report per-cpu work items which hog CPU for too long"
1204 depends on DEBUG_KERNEL
1206 Say Y here to enable reporting of concurrency-managed per-cpu work
1207 items that hog CPUs for longer than
1208 workqueue.cpu_intensive_thresh_us. Workqueue automatically
1209 detects and excludes them from concurrency management to prevent
1210 them from stalling other per-cpu work items. Occassional
1211 triggering may not necessarily indicate a problem. Repeated
1212 triggering likely indicates that the work item should be switched
1213 to use an unbound workqueue.
1216 tristate "Test module to generate lockups"
1219 This builds the "test_lockup" module that helps to make sure
1220 that watchdogs and lockup detectors are working properly.
1222 Depending on module parameters it could emulate soft or hard
1223 lockup, "hung task", or locking arbitrary lock for a long time.
1224 Also it could generate series of lockups with cooling-down periods.
1228 endmenu # "Debug lockups and hangs"
1230 menu "Scheduler Debugging"
1233 bool "Collect scheduler debugging info"
1234 depends on DEBUG_KERNEL && DEBUG_FS
1237 If you say Y here, the /sys/kernel/debug/sched file will be provided
1238 that can help debug the scheduler. The runtime overhead of this
1246 bool "Collect scheduler statistics"
1247 depends on DEBUG_KERNEL && PROC_FS
1250 If you say Y here, additional code will be inserted into the
1251 scheduler and related routines to collect statistics about
1252 scheduler behavior and provide them in /proc/schedstat. These
1253 stats may be useful for both tuning and debugging the scheduler
1254 If you aren't debugging the scheduler or trying to tune a specific
1255 application, you can say N to avoid the very slight overhead
1260 config DEBUG_TIMEKEEPING
1261 bool "Enable extra timekeeping sanity checking"
1263 This option will enable additional timekeeping sanity checks
1264 which may be helpful when diagnosing issues where timekeeping
1265 problems are suspected.
1267 This may include checks in the timekeeping hotpaths, so this
1268 option may have a (very small) performance impact to some
1273 config DEBUG_PREEMPT
1274 bool "Debug preemptible kernel"
1275 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1277 If you say Y here then the kernel will use a debug variant of the
1278 commonly used smp_processor_id() function and will print warnings
1279 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1280 will detect preemption count underflows.
1282 This option has potential to introduce high runtime overhead,
1283 depending on workload as it triggers debugging routines for each
1284 this_cpu operation. It should only be used for debugging purposes.
1286 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1288 config LOCK_DEBUGGING_SUPPORT
1290 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1293 config PROVE_LOCKING
1294 bool "Lock debugging: prove locking correctness"
1295 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1297 select DEBUG_SPINLOCK
1298 select DEBUG_MUTEXES if !PREEMPT_RT
1299 select DEBUG_RT_MUTEXES if RT_MUTEXES
1301 select DEBUG_WW_MUTEX_SLOWPATH
1302 select DEBUG_LOCK_ALLOC
1303 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1304 select TRACE_IRQFLAGS
1307 This feature enables the kernel to prove that all locking
1308 that occurs in the kernel runtime is mathematically
1309 correct: that under no circumstance could an arbitrary (and
1310 not yet triggered) combination of observed locking
1311 sequences (on an arbitrary number of CPUs, running an
1312 arbitrary number of tasks and interrupt contexts) cause a
1315 In short, this feature enables the kernel to report locking
1316 related deadlocks before they actually occur.
1318 The proof does not depend on how hard and complex a
1319 deadlock scenario would be to trigger: how many
1320 participant CPUs, tasks and irq-contexts would be needed
1321 for it to trigger. The proof also does not depend on
1322 timing: if a race and a resulting deadlock is possible
1323 theoretically (no matter how unlikely the race scenario
1324 is), it will be proven so and will immediately be
1325 reported by the kernel (once the event is observed that
1326 makes the deadlock theoretically possible).
1328 If a deadlock is impossible (i.e. the locking rules, as
1329 observed by the kernel, are mathematically correct), the
1330 kernel reports nothing.
1332 NOTE: this feature can also be enabled for rwlocks, mutexes
1333 and rwsems - in which case all dependencies between these
1334 different locking variants are observed and mapped too, and
1335 the proof of observed correctness is also maintained for an
1336 arbitrary combination of these separate locking variants.
1338 For more details, see Documentation/locking/lockdep-design.rst.
1340 config PROVE_RAW_LOCK_NESTING
1341 bool "Enable raw_spinlock - spinlock nesting checks"
1342 depends on PROVE_LOCKING
1345 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1346 that the lock nesting rules for PREEMPT_RT enabled kernels are
1349 NOTE: There are known nesting problems. So if you enable this
1350 option expect lockdep splats until these problems have been fully
1351 addressed which is work in progress. This config switch allows to
1352 identify and analyze these problems. It will be removed and the
1353 check permanently enabled once the main issues have been fixed.
1355 If unsure, select N.
1358 bool "Lock usage statistics"
1359 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1361 select DEBUG_SPINLOCK
1362 select DEBUG_MUTEXES if !PREEMPT_RT
1363 select DEBUG_RT_MUTEXES if RT_MUTEXES
1364 select DEBUG_LOCK_ALLOC
1367 This feature enables tracking lock contention points
1369 For more details, see Documentation/locking/lockstat.rst
1371 This also enables lock events required by "perf lock",
1373 If you want to use "perf lock", you also need to turn on
1374 CONFIG_EVENT_TRACING.
1376 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1377 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1379 config DEBUG_RT_MUTEXES
1380 bool "RT Mutex debugging, deadlock detection"
1381 depends on DEBUG_KERNEL && RT_MUTEXES
1383 This allows rt mutex semantics violations and rt mutex related
1384 deadlocks (lockups) to be detected and reported automatically.
1386 config DEBUG_SPINLOCK
1387 bool "Spinlock and rw-lock debugging: basic checks"
1388 depends on DEBUG_KERNEL
1389 select UNINLINE_SPIN_UNLOCK
1391 Say Y here and build SMP to catch missing spinlock initialization
1392 and certain other kinds of spinlock errors commonly made. This is
1393 best used in conjunction with the NMI watchdog so that spinlock
1394 deadlocks are also debuggable.
1396 config DEBUG_MUTEXES
1397 bool "Mutex debugging: basic checks"
1398 depends on DEBUG_KERNEL && !PREEMPT_RT
1400 This feature allows mutex semantics violations to be detected and
1403 config DEBUG_WW_MUTEX_SLOWPATH
1404 bool "Wait/wound mutex debugging: Slowpath testing"
1405 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1406 select DEBUG_LOCK_ALLOC
1407 select DEBUG_SPINLOCK
1408 select DEBUG_MUTEXES if !PREEMPT_RT
1409 select DEBUG_RT_MUTEXES if PREEMPT_RT
1411 This feature enables slowpath testing for w/w mutex users by
1412 injecting additional -EDEADLK wound/backoff cases. Together with
1413 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1414 will test all possible w/w mutex interface abuse with the
1415 exception of simply not acquiring all the required locks.
1416 Note that this feature can introduce significant overhead, so
1417 it really should not be enabled in a production or distro kernel,
1418 even a debug kernel. If you are a driver writer, enable it. If
1419 you are a distro, do not.
1422 bool "RW Semaphore debugging: basic checks"
1423 depends on DEBUG_KERNEL
1425 This debugging feature allows mismatched rw semaphore locks
1426 and unlocks to be detected and reported.
1428 config DEBUG_LOCK_ALLOC
1429 bool "Lock debugging: detect incorrect freeing of live locks"
1430 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1431 select DEBUG_SPINLOCK
1432 select DEBUG_MUTEXES if !PREEMPT_RT
1433 select DEBUG_RT_MUTEXES if RT_MUTEXES
1436 This feature will check whether any held lock (spinlock, rwlock,
1437 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1438 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1439 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1440 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1441 held during task exit.
1445 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1450 config LOCKDEP_SMALL
1454 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1455 depends on LOCKDEP && !LOCKDEP_SMALL
1459 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1461 config LOCKDEP_CHAINS_BITS
1462 int "Bitsize for MAX_LOCKDEP_CHAINS"
1463 depends on LOCKDEP && !LOCKDEP_SMALL
1467 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1469 config LOCKDEP_STACK_TRACE_BITS
1470 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1471 depends on LOCKDEP && !LOCKDEP_SMALL
1475 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1477 config LOCKDEP_STACK_TRACE_HASH_BITS
1478 int "Bitsize for STACK_TRACE_HASH_SIZE"
1479 depends on LOCKDEP && !LOCKDEP_SMALL
1483 Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1485 config LOCKDEP_CIRCULAR_QUEUE_BITS
1486 int "Bitsize for elements in circular_queue struct"
1491 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1493 config DEBUG_LOCKDEP
1494 bool "Lock dependency engine debugging"
1495 depends on DEBUG_KERNEL && LOCKDEP
1496 select DEBUG_IRQFLAGS
1498 If you say Y here, the lock dependency engine will do
1499 additional runtime checks to debug itself, at the price
1500 of more runtime overhead.
1502 config DEBUG_ATOMIC_SLEEP
1503 bool "Sleep inside atomic section checking"
1504 select PREEMPT_COUNT
1505 depends on DEBUG_KERNEL
1506 depends on !ARCH_NO_PREEMPT
1508 If you say Y here, various routines which may sleep will become very
1509 noisy if they are called inside atomic sections: when a spinlock is
1510 held, inside an rcu read side critical section, inside preempt disabled
1511 sections, inside an interrupt, etc...
1513 config DEBUG_LOCKING_API_SELFTESTS
1514 bool "Locking API boot-time self-tests"
1515 depends on DEBUG_KERNEL
1517 Say Y here if you want the kernel to run a short self-test during
1518 bootup. The self-test checks whether common types of locking bugs
1519 are detected by debugging mechanisms or not. (if you disable
1520 lock debugging then those bugs won't be detected of course.)
1521 The following locking APIs are covered: spinlocks, rwlocks,
1524 config LOCK_TORTURE_TEST
1525 tristate "torture tests for locking"
1526 depends on DEBUG_KERNEL
1529 This option provides a kernel module that runs torture tests
1530 on kernel locking primitives. The kernel module may be built
1531 after the fact on the running kernel to be tested, if desired.
1533 Say Y here if you want kernel locking-primitive torture tests
1534 to be built into the kernel.
1535 Say M if you want these torture tests to build as a module.
1536 Say N if you are unsure.
1538 config WW_MUTEX_SELFTEST
1539 tristate "Wait/wound mutex selftests"
1541 This option provides a kernel module that runs tests on the
1542 on the struct ww_mutex locking API.
1544 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1545 with this test harness.
1547 Say M if you want these self tests to build as a module.
1548 Say N if you are unsure.
1550 config SCF_TORTURE_TEST
1551 tristate "torture tests for smp_call_function*()"
1552 depends on DEBUG_KERNEL
1555 This option provides a kernel module that runs torture tests
1556 on the smp_call_function() family of primitives. The kernel
1557 module may be built after the fact on the running kernel to
1558 be tested, if desired.
1560 config CSD_LOCK_WAIT_DEBUG
1561 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1562 depends on DEBUG_KERNEL
1566 This option enables debug prints when CPUs are slow to respond
1567 to the smp_call_function*() IPI wrappers. These debug prints
1568 include the IPI handler function currently executing (if any)
1569 and relevant stack traces.
1571 config CSD_LOCK_WAIT_DEBUG_DEFAULT
1572 bool "Default csd_lock_wait() debugging on at boot time"
1573 depends on CSD_LOCK_WAIT_DEBUG
1577 This option causes the csdlock_debug= kernel boot parameter to
1578 default to 1 (basic debugging) instead of 0 (no debugging).
1580 endmenu # lock debugging
1582 config TRACE_IRQFLAGS
1583 depends on TRACE_IRQFLAGS_SUPPORT
1586 Enables hooks to interrupt enabling and disabling for
1587 either tracing or lock debugging.
1589 config TRACE_IRQFLAGS_NMI
1591 depends on TRACE_IRQFLAGS
1592 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1594 config NMI_CHECK_CPU
1595 bool "Debugging for CPUs failing to respond to backtrace requests"
1596 depends on DEBUG_KERNEL
1600 Enables debug prints when a CPU fails to respond to a given
1601 backtrace NMI. These prints provide some reasons why a CPU
1602 might legitimately be failing to respond, for example, if it
1603 is offline of if ignore_nmis is set.
1605 config DEBUG_IRQFLAGS
1606 bool "Debug IRQ flag manipulation"
1608 Enables checks for potentially unsafe enabling or disabling of
1609 interrupts, such as calling raw_local_irq_restore() when interrupts
1613 bool "Stack backtrace support"
1614 depends on STACKTRACE_SUPPORT
1616 This option causes the kernel to create a /proc/pid/stack for
1617 every process, showing its current stack trace.
1618 It is also used by various kernel debugging features that require
1619 stack trace generation.
1621 config WARN_ALL_UNSEEDED_RANDOM
1622 bool "Warn for all uses of unseeded randomness"
1625 Some parts of the kernel contain bugs relating to their use of
1626 cryptographically secure random numbers before it's actually possible
1627 to generate those numbers securely. This setting ensures that these
1628 flaws don't go unnoticed, by enabling a message, should this ever
1629 occur. This will allow people with obscure setups to know when things
1630 are going wrong, so that they might contact developers about fixing
1633 Unfortunately, on some models of some architectures getting
1634 a fully seeded CRNG is extremely difficult, and so this can
1635 result in dmesg getting spammed for a surprisingly long
1636 time. This is really bad from a security perspective, and
1637 so architecture maintainers really need to do what they can
1638 to get the CRNG seeded sooner after the system is booted.
1639 However, since users cannot do anything actionable to
1640 address this, by default this option is disabled.
1642 Say Y here if you want to receive warnings for all uses of
1643 unseeded randomness. This will be of use primarily for
1644 those developers interested in improving the security of
1645 Linux kernels running on their architecture (or
1648 config DEBUG_KOBJECT
1649 bool "kobject debugging"
1650 depends on DEBUG_KERNEL
1652 If you say Y here, some extra kobject debugging messages will be sent
1655 config DEBUG_KOBJECT_RELEASE
1656 bool "kobject release debugging"
1657 depends on DEBUG_OBJECTS_TIMERS
1659 kobjects are reference counted objects. This means that their
1660 last reference count put is not predictable, and the kobject can
1661 live on past the point at which a driver decides to drop its
1662 initial reference to the kobject gained on allocation. An
1663 example of this would be a struct device which has just been
1666 However, some buggy drivers assume that after such an operation,
1667 the memory backing the kobject can be immediately freed. This
1668 goes completely against the principles of a refcounted object.
1670 If you say Y here, the kernel will delay the release of kobjects
1671 on the last reference count to improve the visibility of this
1672 kind of kobject release bug.
1674 config HAVE_DEBUG_BUGVERBOSE
1677 menu "Debug kernel data structures"
1680 bool "Debug linked list manipulation"
1681 depends on DEBUG_KERNEL
1682 select LIST_HARDENED
1684 Enable this to turn on extended checks in the linked-list walking
1687 This option trades better quality error reports for performance, and
1688 is more suitable for kernel debugging. If you care about performance,
1689 you should only enable CONFIG_LIST_HARDENED instead.
1694 bool "Debug priority linked list manipulation"
1695 depends on DEBUG_KERNEL
1697 Enable this to turn on extended checks in the priority-ordered
1698 linked-list (plist) walking routines. This checks the entire
1699 list multiple times during each manipulation.
1704 bool "Debug SG table operations"
1705 depends on DEBUG_KERNEL
1707 Enable this to turn on checks on scatter-gather tables. This can
1708 help find problems with drivers that do not properly initialize
1713 config DEBUG_NOTIFIERS
1714 bool "Debug notifier call chains"
1715 depends on DEBUG_KERNEL
1717 Enable this to turn on sanity checking for notifier call chains.
1718 This is most useful for kernel developers to make sure that
1719 modules properly unregister themselves from notifier chains.
1720 This is a relatively cheap check but if you care about maximum
1723 config DEBUG_CLOSURES
1724 bool "Debug closures (bcache async widgits)"
1728 Keeps all active closures in a linked list and provides a debugfs
1729 interface to list them, which makes it possible to see asynchronous
1730 operations that get stuck.
1732 config DEBUG_MAPLE_TREE
1733 bool "Debug maple trees"
1734 depends on DEBUG_KERNEL
1736 Enable maple tree debugging information and extra validations.
1742 config DEBUG_CREDENTIALS
1743 bool "Debug credential management"
1744 depends on DEBUG_KERNEL
1746 Enable this to turn on some debug checking for credential
1747 management. The additional code keeps track of the number of
1748 pointers from task_structs to any given cred struct, and checks to
1749 see that this number never exceeds the usage count of the cred
1752 Furthermore, if SELinux is enabled, this also checks that the
1753 security pointer in the cred struct is never seen to be invalid.
1757 source "kernel/rcu/Kconfig.debug"
1759 config DEBUG_WQ_FORCE_RR_CPU
1760 bool "Force round-robin CPU selection for unbound work items"
1761 depends on DEBUG_KERNEL
1764 Workqueue used to implicitly guarantee that work items queued
1765 without explicit CPU specified are put on the local CPU. This
1766 guarantee is no longer true and while local CPU is still
1767 preferred work items may be put on foreign CPUs. Kernel
1768 parameter "workqueue.debug_force_rr_cpu" is added to force
1769 round-robin CPU selection to flush out usages which depend on the
1770 now broken guarantee. This config option enables the debug
1771 feature by default. When enabled, memory and cache locality will
1774 config CPU_HOTPLUG_STATE_CONTROL
1775 bool "Enable CPU hotplug state control"
1776 depends on DEBUG_KERNEL
1777 depends on HOTPLUG_CPU
1780 Allows to write steps between "offline" and "online" to the CPUs
1781 sysfs target file so states can be stepped granular. This is a debug
1782 option for now as the hotplug machinery cannot be stopped and
1783 restarted at arbitrary points yet.
1785 Say N if your are unsure.
1788 bool "Latency measuring infrastructure"
1789 depends on DEBUG_KERNEL
1790 depends on STACKTRACE_SUPPORT
1792 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1798 Enable this option if you want to use the LatencyTOP tool
1799 to find out which userspace is blocking on what kernel operations.
1801 config DEBUG_CGROUP_REF
1802 bool "Disable inlining of cgroup css reference count functions"
1803 depends on DEBUG_KERNEL
1808 Force cgroup css reference count functions to not be inlined so
1809 that they can be kprobed for debugging.
1811 source "kernel/trace/Kconfig"
1813 config PROVIDE_OHCI1394_DMA_INIT
1814 bool "Remote debugging over FireWire early on boot"
1815 depends on PCI && X86
1817 If you want to debug problems which hang or crash the kernel early
1818 on boot and the crashing machine has a FireWire port, you can use
1819 this feature to remotely access the memory of the crashed machine
1820 over FireWire. This employs remote DMA as part of the OHCI1394
1821 specification which is now the standard for FireWire controllers.
1823 With remote DMA, you can monitor the printk buffer remotely using
1824 firescope and access all memory below 4GB using fireproxy from gdb.
1825 Even controlling a kernel debugger is possible using remote DMA.
1829 If ohci1394_dma=early is used as boot parameter, it will initialize
1830 all OHCI1394 controllers which are found in the PCI config space.
1832 As all changes to the FireWire bus such as enabling and disabling
1833 devices cause a bus reset and thereby disable remote DMA for all
1834 devices, be sure to have the cable plugged and FireWire enabled on
1835 the debugging host before booting the debug target for debugging.
1837 This code (~1k) is freed after boot. By then, the firewire stack
1838 in charge of the OHCI-1394 controllers should be used instead.
1840 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1842 source "samples/Kconfig"
1844 config ARCH_HAS_DEVMEM_IS_ALLOWED
1847 config STRICT_DEVMEM
1848 bool "Filter access to /dev/mem"
1849 depends on MMU && DEVMEM
1850 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1851 default y if PPC || X86 || ARM64
1853 If this option is disabled, you allow userspace (root) access to all
1854 of memory, including kernel and userspace memory. Accidental
1855 access to this is obviously disastrous, but specific access can
1856 be used by people debugging the kernel. Note that with PAT support
1857 enabled, even in this case there are restrictions on /dev/mem
1858 use due to the cache aliasing requirements.
1860 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1861 file only allows userspace access to PCI space and the BIOS code and
1862 data regions. This is sufficient for dosemu and X and all common
1867 config IO_STRICT_DEVMEM
1868 bool "Filter I/O access to /dev/mem"
1869 depends on STRICT_DEVMEM
1871 If this option is disabled, you allow userspace (root) access to all
1872 io-memory regardless of whether a driver is actively using that
1873 range. Accidental access to this is obviously disastrous, but
1874 specific access can be used by people debugging kernel drivers.
1876 If this option is switched on, the /dev/mem file only allows
1877 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1878 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1879 if the driver using a given range cannot be disabled.
1883 menu "$(SRCARCH) Debugging"
1885 source "arch/$(SRCARCH)/Kconfig.debug"
1889 menu "Kernel Testing and Coverage"
1891 source "lib/kunit/Kconfig"
1893 config NOTIFIER_ERROR_INJECTION
1894 tristate "Notifier error injection"
1895 depends on DEBUG_KERNEL
1898 This option provides the ability to inject artificial errors to
1899 specified notifier chain callbacks. It is useful to test the error
1900 handling of notifier call chain failures.
1904 config PM_NOTIFIER_ERROR_INJECT
1905 tristate "PM notifier error injection module"
1906 depends on PM && NOTIFIER_ERROR_INJECTION
1907 default m if PM_DEBUG
1909 This option provides the ability to inject artificial errors to
1910 PM notifier chain callbacks. It is controlled through debugfs
1911 interface /sys/kernel/debug/notifier-error-inject/pm
1913 If the notifier call chain should be failed with some events
1914 notified, write the error code to "actions/<notifier event>/error".
1916 Example: Inject PM suspend error (-12 = -ENOMEM)
1918 # cd /sys/kernel/debug/notifier-error-inject/pm/
1919 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1920 # echo mem > /sys/power/state
1921 bash: echo: write error: Cannot allocate memory
1923 To compile this code as a module, choose M here: the module will
1924 be called pm-notifier-error-inject.
1928 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1929 tristate "OF reconfig notifier error injection module"
1930 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1932 This option provides the ability to inject artificial errors to
1933 OF reconfig notifier chain callbacks. It is controlled
1934 through debugfs interface under
1935 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1937 If the notifier call chain should be failed with some events
1938 notified, write the error code to "actions/<notifier event>/error".
1940 To compile this code as a module, choose M here: the module will
1941 be called of-reconfig-notifier-error-inject.
1945 config NETDEV_NOTIFIER_ERROR_INJECT
1946 tristate "Netdev notifier error injection module"
1947 depends on NET && NOTIFIER_ERROR_INJECTION
1949 This option provides the ability to inject artificial errors to
1950 netdevice notifier chain callbacks. It is controlled through debugfs
1951 interface /sys/kernel/debug/notifier-error-inject/netdev
1953 If the notifier call chain should be failed with some events
1954 notified, write the error code to "actions/<notifier event>/error".
1956 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1958 # cd /sys/kernel/debug/notifier-error-inject/netdev
1959 # echo -22 > actions/NETDEV_CHANGEMTU/error
1960 # ip link set eth0 mtu 1024
1961 RTNETLINK answers: Invalid argument
1963 To compile this code as a module, choose M here: the module will
1964 be called netdev-notifier-error-inject.
1968 config FUNCTION_ERROR_INJECTION
1969 bool "Fault-injections of functions"
1970 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1972 Add fault injections into various functions that are annotated with
1973 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
1974 value of these functions. This is useful to test error paths of code.
1978 config FAULT_INJECTION
1979 bool "Fault-injection framework"
1980 depends on DEBUG_KERNEL
1982 Provide fault-injection framework.
1983 For more details, see Documentation/fault-injection/.
1986 bool "Fault-injection capability for kmalloc"
1987 depends on FAULT_INJECTION
1988 depends on SLAB || SLUB
1990 Provide fault-injection capability for kmalloc.
1992 config FAIL_PAGE_ALLOC
1993 bool "Fault-injection capability for alloc_pages()"
1994 depends on FAULT_INJECTION
1996 Provide fault-injection capability for alloc_pages().
1998 config FAULT_INJECTION_USERCOPY
1999 bool "Fault injection capability for usercopy functions"
2000 depends on FAULT_INJECTION
2002 Provides fault-injection capability to inject failures
2003 in usercopy functions (copy_from_user(), get_user(), ...).
2005 config FAIL_MAKE_REQUEST
2006 bool "Fault-injection capability for disk IO"
2007 depends on FAULT_INJECTION && BLOCK
2009 Provide fault-injection capability for disk IO.
2011 config FAIL_IO_TIMEOUT
2012 bool "Fault-injection capability for faking disk interrupts"
2013 depends on FAULT_INJECTION && BLOCK
2015 Provide fault-injection capability on end IO handling. This
2016 will make the block layer "forget" an interrupt as configured,
2017 thus exercising the error handling.
2019 Only works with drivers that use the generic timeout handling,
2020 for others it won't do anything.
2023 bool "Fault-injection capability for futexes"
2025 depends on FAULT_INJECTION && FUTEX
2027 Provide fault-injection capability for futexes.
2029 config FAULT_INJECTION_DEBUG_FS
2030 bool "Debugfs entries for fault-injection capabilities"
2031 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2033 Enable configuration of fault-injection capabilities via debugfs.
2035 config FAIL_FUNCTION
2036 bool "Fault-injection capability for functions"
2037 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2039 Provide function-based fault-injection capability.
2040 This will allow you to override a specific function with a return
2041 with given return value. As a result, function caller will see
2042 an error value and have to handle it. This is useful to test the
2043 error handling in various subsystems.
2045 config FAIL_MMC_REQUEST
2046 bool "Fault-injection capability for MMC IO"
2047 depends on FAULT_INJECTION_DEBUG_FS && MMC
2049 Provide fault-injection capability for MMC IO.
2050 This will make the mmc core return data errors. This is
2051 useful to test the error handling in the mmc block device
2052 and to test how the mmc host driver handles retries from
2056 bool "Fault-injection capability for SunRPC"
2057 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2059 Provide fault-injection capability for SunRPC and
2062 config FAULT_INJECTION_CONFIGFS
2063 bool "Configfs interface for fault-injection capabilities"
2064 depends on FAULT_INJECTION
2067 This option allows configfs-based drivers to dynamically configure
2068 fault-injection via configfs. Each parameter for driver-specific
2069 fault-injection can be made visible as a configfs attribute in a
2073 config FAULT_INJECTION_STACKTRACE_FILTER
2074 bool "stacktrace filter for fault-injection capabilities"
2075 depends on FAULT_INJECTION
2076 depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
2078 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2080 Provide stacktrace filter for fault-injection capabilities
2082 config ARCH_HAS_KCOV
2085 An architecture should select this when it can successfully
2086 build and run with CONFIG_KCOV. This typically requires
2087 disabling instrumentation for some early boot code.
2089 config CC_HAS_SANCOV_TRACE_PC
2090 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2094 bool "Code coverage for fuzzing"
2095 depends on ARCH_HAS_KCOV
2096 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2097 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2098 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
2100 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2101 select OBJTOOL if HAVE_NOINSTR_HACK
2103 KCOV exposes kernel code coverage information in a form suitable
2104 for coverage-guided fuzzing (randomized testing).
2106 If RANDOMIZE_BASE is enabled, PC values will not be stable across
2107 different machines and across reboots. If you need stable PC values,
2108 disable RANDOMIZE_BASE.
2110 For more details, see Documentation/dev-tools/kcov.rst.
2112 config KCOV_ENABLE_COMPARISONS
2113 bool "Enable comparison operands collection by KCOV"
2115 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2117 KCOV also exposes operands of every comparison in the instrumented
2118 code along with operand sizes and PCs of the comparison instructions.
2119 These operands can be used by fuzzing engines to improve the quality
2120 of fuzzing coverage.
2122 config KCOV_INSTRUMENT_ALL
2123 bool "Instrument all code by default"
2127 If you are doing generic system call fuzzing (like e.g. syzkaller),
2128 then you will want to instrument the whole kernel and you should
2129 say y here. If you are doing more targeted fuzzing (like e.g.
2130 filesystem fuzzing with AFL) then you will want to enable coverage
2131 for more specific subsets of files, and should say n here.
2133 config KCOV_IRQ_AREA_SIZE
2134 hex "Size of interrupt coverage collection area in words"
2138 KCOV uses preallocated per-cpu areas to collect coverage from
2139 soft interrupts. This specifies the size of those areas in the
2140 number of unsigned long words.
2142 menuconfig RUNTIME_TESTING_MENU
2143 bool "Runtime Testing"
2146 if RUNTIME_TESTING_MENU
2149 tristate "Dhrystone benchmark test"
2151 Enable this to include the Dhrystone 2.1 benchmark. This test
2152 calculates the number of Dhrystones per second, and the number of
2153 DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2154 by 1757 (the number of Dhrystones per second obtained on the VAX
2155 11/780, nominally a 1 MIPS machine).
2157 To run the benchmark, it needs to be enabled explicitly, either from
2158 the kernel command line (when built-in), or from userspace (when
2159 built-in or modular.
2161 Run once during kernel boot:
2165 Set number of iterations from kernel command line:
2167 test_dhry.iterations=<n>
2169 Set number of iterations from userspace:
2171 echo <n> > /sys/module/test_dhry/parameters/iterations
2173 Trigger manual run from userspace:
2175 echo y > /sys/module/test_dhry/parameters/run
2177 If the number of iterations is <= 0, the test will devise a suitable
2178 number of iterations (test runs for at least 2s) automatically.
2179 This process takes ca. 4s.
2184 tristate "Linux Kernel Dump Test Tool Module"
2187 This module enables testing of the different dumping mechanisms by
2188 inducing system failures at predefined crash points.
2189 If you don't need it: say N
2190 Choose M here to compile this code as a module. The module will be
2193 Documentation on how to use the module can be found in
2194 Documentation/fault-injection/provoke-crashes.rst
2196 config CPUMASK_KUNIT_TEST
2197 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2199 default KUNIT_ALL_TESTS
2201 Enable to turn on cpumask tests, running at boot or module load time.
2203 For more information on KUnit and unit tests in general, please refer
2204 to the KUnit documentation in Documentation/dev-tools/kunit/.
2208 config TEST_LIST_SORT
2209 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2211 default KUNIT_ALL_TESTS
2213 Enable this to turn on 'list_sort()' function test. This test is
2214 executed only once during system boot (so affects only boot time),
2215 or at module load time.
2219 config TEST_MIN_HEAP
2220 tristate "Min heap test"
2221 depends on DEBUG_KERNEL || m
2223 Enable this to turn on min heap function tests. This test is
2224 executed only once during system boot (so affects only boot time),
2225 or at module load time.
2230 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2232 default KUNIT_ALL_TESTS
2234 This option enables the self-test function of 'sort()' at boot,
2235 or at module load time.
2240 tristate "64bit/32bit division and modulo test"
2241 depends on DEBUG_KERNEL || m
2243 Enable this to turn on 'do_div()' function test. This test is
2244 executed only once during system boot (so affects only boot time),
2245 or at module load time.
2249 config TEST_IOV_ITER
2250 tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2252 default KUNIT_ALL_TESTS
2254 Enable this to turn on testing of the operation of the I/O iterator
2255 (iov_iter). This test is executed only once during system boot (so
2256 affects only boot time), or at module load time.
2260 config KPROBES_SANITY_TEST
2261 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2262 depends on DEBUG_KERNEL
2265 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2266 default KUNIT_ALL_TESTS
2268 This option provides for testing basic kprobes functionality on
2269 boot. Samples of kprobe and kretprobe are inserted and
2270 verified for functionality.
2272 Say N if you are unsure.
2274 config FPROBE_SANITY_TEST
2275 bool "Self test for fprobe"
2276 depends on DEBUG_KERNEL
2280 This option will enable testing the fprobe when the system boot.
2281 A series of tests are made to verify that the fprobe is functioning
2284 Say N if you are unsure.
2286 config BACKTRACE_SELF_TEST
2287 tristate "Self test for the backtrace code"
2288 depends on DEBUG_KERNEL
2290 This option provides a kernel module that can be used to test
2291 the kernel stack backtrace code. This option is not useful
2292 for distributions or general kernels, but only for kernel
2293 developers working on architecture code.
2295 Note that if you want to also test saved backtraces, you will
2296 have to enable STACKTRACE as well.
2298 Say N if you are unsure.
2300 config TEST_REF_TRACKER
2301 tristate "Self test for reference tracker"
2302 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2305 This option provides a kernel module performing tests
2306 using reference tracker infrastructure.
2308 Say N if you are unsure.
2311 tristate "Red-Black tree test"
2312 depends on DEBUG_KERNEL
2314 A benchmark measuring the performance of the rbtree library.
2315 Also includes rbtree invariant checks.
2317 config REED_SOLOMON_TEST
2318 tristate "Reed-Solomon library test"
2319 depends on DEBUG_KERNEL || m
2321 select REED_SOLOMON_ENC16
2322 select REED_SOLOMON_DEC16
2324 This option enables the self-test function of rslib at boot,
2325 or at module load time.
2329 config INTERVAL_TREE_TEST
2330 tristate "Interval tree test"
2331 depends on DEBUG_KERNEL
2332 select INTERVAL_TREE
2334 A benchmark measuring the performance of the interval tree library
2337 tristate "Per cpu operations test"
2338 depends on m && DEBUG_KERNEL
2340 Enable this option to build test module which validates per-cpu
2345 config ATOMIC64_SELFTEST
2346 tristate "Perform an atomic64_t self-test"
2348 Enable this option to test the atomic64_t functions at boot or
2349 at module load time.
2353 config ASYNC_RAID6_TEST
2354 tristate "Self test for hardware accelerated raid6 recovery"
2355 depends on ASYNC_RAID6_RECOV
2358 This is a one-shot self test that permutes through the
2359 recovery of all the possible two disk failure scenarios for a
2360 N-disk array. Recovery is performed with the asynchronous
2361 raid6 recovery routines, and will optionally use an offload
2362 engine if one is available.
2367 tristate "Test functions located in the hexdump module at runtime"
2369 config STRING_SELFTEST
2370 tristate "Test string functions at runtime"
2372 config TEST_STRING_HELPERS
2373 tristate "Test functions located in the string_helpers module at runtime"
2376 tristate "Test kstrto*() family of functions at runtime"
2379 tristate "Test printf() family of functions at runtime"
2382 tristate "Test scanf() family of functions at runtime"
2385 tristate "Test bitmap_*() family of functions at runtime"
2387 Enable this option to test the bitmap functions at boot.
2392 tristate "Test functions located in the uuid module at runtime"
2395 tristate "Test the XArray code at runtime"
2397 config TEST_MAPLE_TREE
2398 tristate "Test the Maple Tree code at runtime or module load"
2400 Enable this option to test the maple tree code functions at boot, or
2401 when the module is loaded. Enable "Debug Maple Trees" will enable
2402 more verbose output on failures.
2406 config TEST_RHASHTABLE
2407 tristate "Perform selftest on resizable hash table"
2409 Enable this option to test the rhashtable functions at boot.
2414 tristate "Perform selftest on IDA functions"
2417 tristate "Perform selftest on priority array manager"
2420 Enable this option to test priority array manager on boot
2425 config TEST_IRQ_TIMINGS
2426 bool "IRQ timings selftest"
2427 depends on IRQ_TIMINGS
2429 Enable this option to test the irq timings code on boot.
2434 tristate "Test module loading with 'hello world' module"
2437 This builds the "test_module" module that emits "Hello, world"
2438 on printk when loaded. It is designed to be used for basic
2439 evaluation of the module loading subsystem (for example when
2440 validating module verification). It lacks any extra dependencies,
2441 and will not normally be loaded by the system unless explicitly
2447 tristate "Test module for compilation of bitops operations"
2450 This builds the "test_bitops" module that is much like the
2451 TEST_LKM module except that it does a basic exercise of the
2452 set/clear_bit macros and get_count_order/long to make sure there are
2453 no compiler warnings from C=1 sparse checker or -Wextra
2454 compilations. It has no dependencies and doesn't run or load unless
2455 explicitly requested by name. for example: modprobe test_bitops.
2460 tristate "Test module for stress/performance analysis of vmalloc allocator"
2465 This builds the "test_vmalloc" module that should be used for
2466 stress and performance analysis. So, any new change for vmalloc
2467 subsystem can be evaluated from performance and stability point
2472 config TEST_USER_COPY
2473 tristate "Test user/kernel boundary protections"
2476 This builds the "test_user_copy" module that runs sanity checks
2477 on the copy_to/from_user infrastructure, making sure basic
2478 user/kernel boundary testing is working. If it fails to load,
2479 a regression has been detected in the user/kernel memory boundary
2485 tristate "Test BPF filter functionality"
2488 This builds the "test_bpf" module that runs various test vectors
2489 against the BPF interpreter or BPF JIT compiler depending on the
2490 current setting. This is in particular useful for BPF JIT compiler
2491 development, but also to run regression tests against changes in
2492 the interpreter code. It also enables test stubs for eBPF maps and
2493 verifier used by user space verifier testsuite.
2497 config TEST_BLACKHOLE_DEV
2498 tristate "Test blackhole netdev functionality"
2501 This builds the "test_blackhole_dev" module that validates the
2502 data path through this blackhole netdev.
2506 config FIND_BIT_BENCHMARK
2507 tristate "Test find_bit functions"
2509 This builds the "test_find_bit" module that measure find_*_bit()
2510 functions performance.
2514 config TEST_FIRMWARE
2515 tristate "Test firmware loading via userspace interface"
2516 depends on FW_LOADER
2518 This builds the "test_firmware" module that creates a userspace
2519 interface for testing firmware loading. This can be used to
2520 control the triggering of firmware loading without needing an
2521 actual firmware-using device. The contents can be rechecked by
2527 tristate "sysctl test driver"
2528 depends on PROC_SYSCTL
2530 This builds the "test_sysctl" module. This driver enables to test the
2531 proc sysctl interfaces available to drivers safely without affecting
2532 production knobs which might alter system functionality.
2536 config BITFIELD_KUNIT
2537 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2539 default KUNIT_ALL_TESTS
2541 Enable this option to test the bitfield functions at boot.
2543 KUnit tests run during boot and output the results to the debug log
2544 in TAP format (http://testanything.org/). Only useful for kernel devs
2545 running the KUnit test harness, and not intended for inclusion into a
2548 For more information on KUnit and unit tests in general please refer
2549 to the KUnit documentation in Documentation/dev-tools/kunit/.
2553 config CHECKSUM_KUNIT
2554 tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2556 default KUNIT_ALL_TESTS
2558 Enable this option to test the checksum functions at boot.
2560 KUnit tests run during boot and output the results to the debug log
2561 in TAP format (http://testanything.org/). Only useful for kernel devs
2562 running the KUnit test harness, and not intended for inclusion into a
2565 For more information on KUnit and unit tests in general please refer
2566 to the KUnit documentation in Documentation/dev-tools/kunit/.
2570 config HASH_KUNIT_TEST
2571 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2573 default KUNIT_ALL_TESTS
2575 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2576 integer (<linux/hash.h>) hash functions on boot.
2578 KUnit tests run during boot and output the results to the debug log
2579 in TAP format (https://testanything.org/). Only useful for kernel devs
2580 running the KUnit test harness, and not intended for inclusion into a
2583 For more information on KUnit and unit tests in general please refer
2584 to the KUnit documentation in Documentation/dev-tools/kunit/.
2586 This is intended to help people writing architecture-specific
2587 optimized versions. If unsure, say N.
2589 config RESOURCE_KUNIT_TEST
2590 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2592 default KUNIT_ALL_TESTS
2594 This builds the resource API unit test.
2595 Tests the logic of API provided by resource.c and ioport.h.
2596 For more information on KUnit and unit tests in general please refer
2597 to the KUnit documentation in Documentation/dev-tools/kunit/.
2601 config SYSCTL_KUNIT_TEST
2602 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2604 default KUNIT_ALL_TESTS
2606 This builds the proc sysctl unit test, which runs on boot.
2607 Tests the API contract and implementation correctness of sysctl.
2608 For more information on KUnit and unit tests in general please refer
2609 to the KUnit documentation in Documentation/dev-tools/kunit/.
2613 config LIST_KUNIT_TEST
2614 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2616 default KUNIT_ALL_TESTS
2618 This builds the linked list KUnit test suite.
2619 It tests that the API and basic functionality of the list_head type
2620 and associated macros.
2622 KUnit tests run during boot and output the results to the debug log
2623 in TAP format (https://testanything.org/). Only useful for kernel devs
2624 running the KUnit test harness, and not intended for inclusion into a
2627 For more information on KUnit and unit tests in general please refer
2628 to the KUnit documentation in Documentation/dev-tools/kunit/.
2632 config HASHTABLE_KUNIT_TEST
2633 tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2635 default KUNIT_ALL_TESTS
2637 This builds the hashtable KUnit test suite.
2638 It tests the basic functionality of the API defined in
2639 include/linux/hashtable.h. For more information on KUnit and
2640 unit tests in general please refer to the KUnit documentation
2641 in Documentation/dev-tools/kunit/.
2645 config LINEAR_RANGES_TEST
2646 tristate "KUnit test for linear_ranges"
2648 select LINEAR_RANGES
2650 This builds the linear_ranges unit test, which runs on boot.
2651 Tests the linear_ranges logic correctness.
2652 For more information on KUnit and unit tests in general please refer
2653 to the KUnit documentation in Documentation/dev-tools/kunit/.
2657 config CMDLINE_KUNIT_TEST
2658 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2660 default KUNIT_ALL_TESTS
2662 This builds the cmdline API unit test.
2663 Tests the logic of API provided by cmdline.c.
2664 For more information on KUnit and unit tests in general please refer
2665 to the KUnit documentation in Documentation/dev-tools/kunit/.
2670 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2672 default KUNIT_ALL_TESTS
2674 This builds the bits unit test.
2675 Tests the logic of macros defined in bits.h.
2676 For more information on KUnit and unit tests in general please refer
2677 to the KUnit documentation in Documentation/dev-tools/kunit/.
2681 config SLUB_KUNIT_TEST
2682 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2683 depends on SLUB_DEBUG && KUNIT
2684 default KUNIT_ALL_TESTS
2686 This builds SLUB allocator unit test.
2687 Tests SLUB cache debugging functionality.
2688 For more information on KUnit and unit tests in general please refer
2689 to the KUnit documentation in Documentation/dev-tools/kunit/.
2693 config RATIONAL_KUNIT_TEST
2694 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2695 depends on KUNIT && RATIONAL
2696 default KUNIT_ALL_TESTS
2698 This builds the rational math unit test.
2699 For more information on KUnit and unit tests in general please refer
2700 to the KUnit documentation in Documentation/dev-tools/kunit/.
2704 config MEMCPY_KUNIT_TEST
2705 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2707 default KUNIT_ALL_TESTS
2709 Builds unit tests for memcpy(), memmove(), and memset() functions.
2710 For more information on KUnit and unit tests in general please refer
2711 to the KUnit documentation in Documentation/dev-tools/kunit/.
2715 config MEMCPY_SLOW_KUNIT_TEST
2716 bool "Include exhaustive memcpy tests"
2717 depends on MEMCPY_KUNIT_TEST
2720 Some memcpy tests are quite exhaustive in checking for overlaps
2721 and bit ranges. These can be very slow, so they are split out
2722 as a separate config, in case they need to be disabled.
2724 Note this config option will be replaced by the use of KUnit test
2727 config IS_SIGNED_TYPE_KUNIT_TEST
2728 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2730 default KUNIT_ALL_TESTS
2732 Builds unit tests for the is_signed_type() macro.
2734 For more information on KUnit and unit tests in general please refer
2735 to the KUnit documentation in Documentation/dev-tools/kunit/.
2739 config OVERFLOW_KUNIT_TEST
2740 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2742 default KUNIT_ALL_TESTS
2744 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2747 For more information on KUnit and unit tests in general please refer
2748 to the KUnit documentation in Documentation/dev-tools/kunit/.
2752 config STACKINIT_KUNIT_TEST
2753 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2755 default KUNIT_ALL_TESTS
2757 Test if the kernel is zero-initializing stack variables and
2758 padding. Coverage is controlled by compiler flags,
2759 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2760 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2761 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2763 config FORTIFY_KUNIT_TEST
2764 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2765 depends on KUNIT && FORTIFY_SOURCE
2766 default KUNIT_ALL_TESTS
2768 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2769 by the str*() and mem*() family of functions. For testing runtime
2770 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2772 config HW_BREAKPOINT_KUNIT_TEST
2773 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2774 depends on HAVE_HW_BREAKPOINT
2776 default KUNIT_ALL_TESTS
2778 Tests for hw_breakpoint constraints accounting.
2782 config STRCAT_KUNIT_TEST
2783 tristate "Test strcat() family of functions at runtime" if !KUNIT_ALL_TESTS
2785 default KUNIT_ALL_TESTS
2787 config STRSCPY_KUNIT_TEST
2788 tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
2790 default KUNIT_ALL_TESTS
2792 config SIPHASH_KUNIT_TEST
2793 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2795 default KUNIT_ALL_TESTS
2797 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2798 functions on boot (or module load).
2800 This is intended to help people writing architecture-specific
2801 optimized versions. If unsure, say N.
2804 tristate "udelay test driver"
2806 This builds the "udelay_test" module that helps to make sure
2807 that udelay() is working properly.
2811 config TEST_STATIC_KEYS
2812 tristate "Test static keys"
2815 Test the static key interfaces.
2819 config TEST_DYNAMIC_DEBUG
2820 tristate "Test DYNAMIC_DEBUG"
2821 depends on DYNAMIC_DEBUG
2823 This module registers a tracer callback to count enabled
2824 pr_debugs in a 'do_debugging' function, then alters their
2825 enablements, calls the function, and compares counts.
2830 tristate "kmod stress tester"
2832 depends on NETDEVICES && NET_CORE && INET # for TUN
2834 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2840 Test the kernel's module loading mechanism: kmod. kmod implements
2841 support to load modules using the Linux kernel's usermode helper.
2842 This test provides a series of tests against kmod.
2844 Although technically you can either build test_kmod as a module or
2845 into the kernel we disallow building it into the kernel since
2846 it stress tests request_module() and this will very likely cause
2847 some issues by taking over precious threads available from other
2848 module load requests, ultimately this could be fatal.
2852 tools/testing/selftests/kmod/kmod.sh --help
2856 config TEST_DEBUG_VIRTUAL
2857 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2858 depends on DEBUG_VIRTUAL
2860 Test the kernel's ability to detect incorrect calls to
2861 virt_to_phys() done against the non-linear part of the
2862 kernel's virtual address map.
2866 config TEST_MEMCAT_P
2867 tristate "Test memcat_p() helper function"
2869 Test the memcat_p() helper for correctly merging two
2870 pointer arrays together.
2874 config TEST_LIVEPATCH
2875 tristate "Test livepatching"
2877 depends on DYNAMIC_DEBUG
2878 depends on LIVEPATCH
2881 Test kernel livepatching features for correctness. The tests will
2882 load test modules that will be livepatched in various scenarios.
2884 To run all the livepatching tests:
2886 make -C tools/testing/selftests TARGETS=livepatch run_tests
2888 Alternatively, individual tests may be invoked:
2890 tools/testing/selftests/livepatch/test-callbacks.sh
2891 tools/testing/selftests/livepatch/test-livepatch.sh
2892 tools/testing/selftests/livepatch/test-shadow-vars.sh
2897 tristate "Perform selftest on object aggreration manager"
2901 Enable this option to test object aggregation manager on boot
2905 tristate "Test heap/page initialization"
2907 Test if the kernel is zero-initializing heap and page allocations.
2908 This can be useful to test init_on_alloc and init_on_free features.
2913 tristate "Test HMM (Heterogeneous Memory Management)"
2914 depends on TRANSPARENT_HUGEPAGE
2915 depends on DEVICE_PRIVATE
2919 This is a pseudo device driver solely for testing HMM.
2920 Say M here if you want to build the HMM test module.
2921 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2925 config TEST_FREE_PAGES
2926 tristate "Test freeing pages"
2928 Test that a memory leak does not occur due to a race between
2929 freeing a block of pages and a speculative page reference.
2930 Loading this module is safe if your kernel has the bug fixed.
2931 If the bug is not fixed, it will leak gigabytes of memory and
2932 probably OOM your system.
2935 tristate "Test floating point operations in kernel space"
2936 depends on X86 && !KCOV_INSTRUMENT_ALL
2938 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2939 which will trigger a sequence of floating point operations. This is used
2940 for self-testing floating point control register setting in
2945 config TEST_CLOCKSOURCE_WATCHDOG
2946 tristate "Test clocksource watchdog in kernel space"
2947 depends on CLOCKSOURCE_WATCHDOG
2949 Enable this option to create a kernel module that will trigger
2950 a test of the clocksource watchdog. This module may be loaded
2951 via modprobe or insmod in which case it will run upon being
2952 loaded, or it may be built in, in which case it will run
2958 tristate "Test module for correctness and stress of objpool"
2960 depends on m && DEBUG_KERNEL
2962 This builds the "test_objpool" module that should be used for
2963 correctness verification and concurrent testings of objects
2964 allocation and reclamation.
2968 endif # RUNTIME_TESTING_MENU
2970 config ARCH_USE_MEMTEST
2973 An architecture should select this when it uses early_memtest()
2974 during boot process.
2978 depends on ARCH_USE_MEMTEST
2980 This option adds a kernel parameter 'memtest', which allows memtest
2981 to be set and executed.
2982 memtest=0, mean disabled; -- default
2983 memtest=1, mean do 1 test pattern;
2985 memtest=17, mean do 17 test patterns.
2986 If you are unsure how to answer this question, answer N.
2990 config HYPERV_TESTING
2991 bool "Microsoft Hyper-V driver testing"
2993 depends on HYPERV && DEBUG_FS
2995 Select this option to enable Hyper-V vmbus testing.
2997 endmenu # "Kernel Testing and Coverage"
3001 config RUST_DEBUG_ASSERTIONS
3002 bool "Debug assertions"
3005 Enables rustc's `-Cdebug-assertions` codegen option.
3007 This flag lets you turn `cfg(debug_assertions)` conditional
3008 compilation on or off. This can be used to enable extra debugging
3009 code in development but not in production. For example, it controls
3010 the behavior of the standard library's `debug_assert!` macro.
3012 Note that this will apply to all Rust code, including `core`.
3016 config RUST_OVERFLOW_CHECKS
3017 bool "Overflow checks"
3021 Enables rustc's `-Coverflow-checks` codegen option.
3023 This flag allows you to control the behavior of runtime integer
3024 overflow. When overflow-checks are enabled, a Rust panic will occur
3027 Note that this will apply to all Rust code, including `core`.
3031 config RUST_BUILD_ASSERT_ALLOW
3032 bool "Allow unoptimized build-time assertions"
3035 Controls how are `build_error!` and `build_assert!` handled during build.
3037 If calls to them exist in the binary, it may indicate a violated invariant
3038 or that the optimizer failed to verify the invariant during compilation.
3040 This should not happen, thus by default the build is aborted. However,
3041 as an escape hatch, you can choose Y here to ignore them during build
3042 and let the check be carried at runtime (with `panic!` being called if
3047 config RUST_KERNEL_DOCTESTS
3048 bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3049 depends on RUST && KUNIT=y
3050 default KUNIT_ALL_TESTS
3052 This builds the documentation tests of the `kernel` crate
3055 For more information on KUnit and unit tests in general,
3056 please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3062 endmenu # Kernel hacking
projects / linux.git / blob