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 jiffy" 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 generates .uleb128 with label differences for DWARF v5, a feature that
235 # older binutils ports do not support when utilizing RISC-V style linker
236 # relaxation: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
237 config AS_HAS_NON_CONST_ULEB128
238 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
241 prompt "Debug information"
242 depends on DEBUG_KERNEL
244 Selecting something other than "None" results in a kernel image
245 that will include debugging info resulting in a larger kernel image.
246 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
250 Choose which version of DWARF debug info to emit. If unsure,
251 select "Toolchain default".
253 config DEBUG_INFO_NONE
254 bool "Disable debug information"
256 Do not build the kernel with debugging information, which will
257 result in a faster and smaller build.
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
260 bool "Rely on the toolchain's implicit default DWARF version"
262 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
264 The implicit default version of DWARF debug info produced by a
265 toolchain changes over time.
267 This can break consumers of the debug info that haven't upgraded to
268 support newer revisions, and prevent testing newer versions, but
269 those should be less common scenarios.
271 config DEBUG_INFO_DWARF4
272 bool "Generate DWARF Version 4 debuginfo"
274 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
276 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
277 if using clang without clang's integrated assembler, and gdb 7.0+.
279 If you have consumers of DWARF debug info that are not ready for
280 newer revisions of DWARF, you may wish to choose this or have your
283 config DEBUG_INFO_DWARF5
284 bool "Generate DWARF Version 5 debuginfo"
286 depends on !ARCH_HAS_BROKEN_DWARF5
287 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
289 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
290 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
291 draft features until 7.0), and gdb 8.0+.
293 Changes to the structure of debug info in Version 5 allow for around
294 15-18% savings in resulting image and debug info section sizes as
295 compared to DWARF Version 4. DWARF Version 5 standardizes previous
296 extensions such as accelerators for symbol indexing and the format
297 for fission (.dwo/.dwp) files. Users may not want to select this
298 config if they rely on tooling that has not yet been updated to
299 support DWARF Version 5.
301 endchoice # "Debug information"
305 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information"
308 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. This means that tools that
310 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need debugging information to
312 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions.
318 prompt "Compressed Debug information"
320 Compress the resulting debug info. Results in smaller debug info sections,
321 but requires that consumers are able to decompress the results.
323 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
325 config DEBUG_INFO_COMPRESSED_NONE
326 bool "Don't compress debug information"
328 Don't compress debug info sections.
330 config DEBUG_INFO_COMPRESSED_ZLIB
331 bool "Compress debugging information with zlib"
332 depends on $(cc-option,-gz=zlib)
333 depends on $(ld-option,--compress-debug-sections=zlib)
335 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
336 5.0+, binutils 2.26+, and zlib.
338 Users of dpkg-deb via scripts/package/builddeb may find an increase in
339 size of their debug .deb packages with this config set, due to the
340 debug info being compressed with zlib, then the object files being
341 recompressed with a different compression scheme. But this is still
342 preferable to setting $KDEB_COMPRESS to "none" which would be even
345 config DEBUG_INFO_COMPRESSED_ZSTD
346 bool "Compress debugging information with zstd"
347 depends on $(cc-option,-gz=zstd)
348 depends on $(ld-option,--compress-debug-sections=zstd)
350 Compress the debug information using zstd. This may provide better
351 compression than zlib, for about the same time costs, but requires newer
352 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
355 endchoice # "Compressed Debug information"
357 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo files"
359 depends on $(cc-option,-gsplit-dwarf)
360 # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
362 # https://github.com/llvm/llvm-project/issues/56642
363 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
364 depends on !RISCV || GCC_VERSION >= 120000
366 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information only once on disk in .dwo
369 files instead of multiple times in object files and executables.
370 In addition the debug information is also compressed.
372 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debug information would need
374 to know about the .dwo files and include them.
375 Incompatible with older versions of ccache.
377 config DEBUG_INFO_BTF
378 bool "Generate BTF type information"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
381 depends on BPF_SYSCALL
382 depends on PAHOLE_VERSION >= 116
383 depends on DEBUG_INFO_DWARF4 || PAHOLE_VERSION >= 121
384 # pahole uses elfutils, which does not have support for Hexagon relocations
387 Generate deduplicated BTF type information from DWARF debug info.
388 Turning this on requires pahole v1.16 or later (v1.21 or later to
389 support DWARF 5), which will convert DWARF type info into equivalent
390 deduplicated BTF type info.
392 config PAHOLE_HAS_SPLIT_BTF
393 def_bool PAHOLE_VERSION >= 119
395 config PAHOLE_HAS_BTF_TAG
396 def_bool PAHOLE_VERSION >= 123
397 depends on CC_IS_CLANG
399 Decide whether pahole emits btf_tag attributes (btf_type_tag and
400 btf_decl_tag) or not. Currently only clang compiler implements
401 these attributes, so make the config depend on CC_IS_CLANG.
403 config PAHOLE_HAS_LANG_EXCLUDE
404 def_bool PAHOLE_VERSION >= 124
406 Support for the --lang_exclude flag which makes pahole exclude
407 compilation units from the supplied language. Used in Kbuild to
408 omit Rust CUs which are not supported in version 1.24 of pahole,
409 otherwise it would emit malformed kernel and module binaries when
410 using DEBUG_INFO_BTF_MODULES.
412 config DEBUG_INFO_BTF_MODULES
413 bool "Generate BTF type information for kernel modules"
415 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
417 Generate compact split BTF type information for kernel modules.
419 config MODULE_ALLOW_BTF_MISMATCH
420 bool "Allow loading modules with non-matching BTF type info"
421 depends on DEBUG_INFO_BTF_MODULES
423 For modules whose split BTF does not match vmlinux, load without
424 BTF rather than refusing to load. The default behavior with
425 module BTF enabled is to reject modules with such mismatches;
426 this option will still load module BTF where possible but ignore
427 it when a mismatch is found.
430 bool "Provide GDB scripts for kernel debugging"
432 This creates the required links to GDB helper scripts in the
433 build directory. If you load vmlinux into gdb, the helper
434 scripts will be automatically imported by gdb as well, and
435 additional functions are available to analyze a Linux kernel
436 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
442 int "Warn for stack frames larger than"
445 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
446 default 2048 if PARISC
447 default 1536 if (!64BIT && XTENSA)
448 default 1280 if KASAN && !64BIT
449 default 1024 if !64BIT
450 default 2048 if 64BIT
452 Tell the compiler to warn at build time for stack frames larger than this.
453 Setting this too low will cause a lot of warnings.
454 Setting it to 0 disables the warning.
456 config STRIP_ASM_SYMS
457 bool "Strip assembler-generated symbols during link"
460 Strip internal assembler-generated symbols during a link (symbols
461 that look like '.Lxxx') so they don't pollute the output of
462 get_wchan() and suchlike.
465 bool "Generate readable assembler code"
466 depends on DEBUG_KERNEL
469 Disable some compiler optimizations that tend to generate human unreadable
470 assembler output. This may make the kernel slightly slower, but it helps
471 to keep kernel developers who have to stare a lot at assembler listings
474 config HEADERS_INSTALL
475 bool "Install uapi headers to usr/include"
478 This option will install uapi headers (headers exported to user-space)
479 into the usr/include directory for use during the kernel build.
480 This is unneeded for building the kernel itself, but needed for some
481 user-space program samples. It is also needed by some features such
482 as uapi header sanity checks.
484 config DEBUG_SECTION_MISMATCH
485 bool "Enable full Section mismatch analysis"
488 The section mismatch analysis checks if there are illegal
489 references from one section to another section.
490 During linktime or runtime, some sections are dropped;
491 any use of code/data previously in these sections would
492 most likely result in an oops.
493 In the code, functions and variables are annotated with
494 __init,, etc. (see the full list in include/linux/init.h),
495 which results in the code/data being placed in specific sections.
496 The section mismatch analysis is always performed after a full
497 kernel build, and enabling this option causes the following
498 additional step to occur:
499 - Add the option -fno-inline-functions-called-once to gcc commands.
500 When inlining a function annotated with __init in a non-init
501 function, we would lose the section information and thus
502 the analysis would not catch the illegal reference.
503 This option tells gcc to inline less (but it does result in
506 config SECTION_MISMATCH_WARN_ONLY
507 bool "Make section mismatch errors non-fatal"
510 If you say N here, the build process will fail if there are any
511 section mismatch, instead of just throwing warnings.
515 config DEBUG_FORCE_FUNCTION_ALIGN_64B
516 bool "Force all function address 64B aligned"
517 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
518 select FUNCTION_ALIGNMENT_64B
520 There are cases that a commit from one domain changes the function
521 address alignment of other domains, and cause magic performance
522 bump (regression or improvement). Enable this option will help to
523 verify if the bump is caused by function alignment changes, while
524 it will slightly increase the kernel size and affect icache usage.
526 It is mainly for debug and performance tuning use.
529 # Select this config option from the architecture Kconfig, if it
530 # is preferred to always offer frame pointers as a config
531 # option on the architecture (regardless of KERNEL_DEBUG):
533 config ARCH_WANT_FRAME_POINTERS
537 bool "Compile the kernel with frame pointers"
538 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
539 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
541 If you say Y here the resulting kernel image will be slightly
542 larger and slower, but it gives very useful debugging information
543 in case of kernel bugs. (precise oopses/stacktraces/warnings)
548 config STACK_VALIDATION
549 bool "Compile-time stack metadata validation"
550 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
554 Validate frame pointer rules at compile-time. This helps ensure that
555 runtime stack traces are more reliable.
557 For more information, see
558 tools/objtool/Documentation/objtool.txt.
560 config NOINSTR_VALIDATION
562 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
567 bool "Generate vmlinux.map file when linking"
570 Selecting this option will pass "-Map=vmlinux.map" to ld
571 when linking vmlinux. That file can be useful for verifying
572 and debugging magic section games, and for seeing which
573 pieces of code get eliminated with
574 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
576 config BUILTIN_MODULE_RANGES
577 bool "Generate address range information for builtin modules"
579 depends on VMLINUX_MAP
581 When modules are built into the kernel, there will be no module name
582 associated with its symbols in /proc/kallsyms. Tracers may want to
583 identify symbols by module name and symbol name regardless of whether
584 the module is configured as loadable or not.
586 This option generates modules.builtin.ranges in the build tree with
587 offset ranges (per ELF section) for the module(s) they belong to.
588 It also records an anchor symbol to determine the load address of the
591 config DEBUG_FORCE_WEAK_PER_CPU
592 bool "Force weak per-cpu definitions"
593 depends on DEBUG_KERNEL
595 s390 and alpha require percpu variables in modules to be
596 defined weak to work around addressing range issue which
597 puts the following two restrictions on percpu variable
600 1. percpu symbols must be unique whether static or not
601 2. percpu variables can't be defined inside a function
603 To ensure that generic code follows the above rules, this
604 option forces all percpu variables to be defined as weak.
606 endmenu # "Compiler options"
608 menu "Generic Kernel Debugging Instruments"
611 bool "Magic SysRq key"
614 If you say Y here, you will have some control over the system even
615 if the system crashes for example during kernel debugging (e.g., you
616 will be able to flush the buffer cache to disk, reboot the system
617 immediately or dump some status information). This is accomplished
618 by pressing various keys while holding SysRq (Alt+PrintScreen). It
619 also works on a serial console (on PC hardware at least), if you
620 send a BREAK and then within 5 seconds a command keypress. The
621 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
622 Don't say Y unless you really know what this hack does.
624 config MAGIC_SYSRQ_DEFAULT_ENABLE
625 hex "Enable magic SysRq key functions by default"
626 depends on MAGIC_SYSRQ
629 Specifies which SysRq key functions are enabled by default.
630 This may be set to 1 or 0 to enable or disable them all, or
631 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
633 config MAGIC_SYSRQ_SERIAL
634 bool "Enable magic SysRq key over serial"
635 depends on MAGIC_SYSRQ
638 Many embedded boards have a disconnected TTL level serial which can
639 generate some garbage that can lead to spurious false sysrq detects.
640 This option allows you to decide whether you want to enable the
643 config MAGIC_SYSRQ_SERIAL_SEQUENCE
644 string "Char sequence that enables magic SysRq over serial"
645 depends on MAGIC_SYSRQ_SERIAL
648 Specifies a sequence of characters that can follow BREAK to enable
649 SysRq on a serial console.
651 If unsure, leave an empty string and the option will not be enabled.
654 bool "Debug Filesystem"
656 debugfs is a virtual file system that kernel developers use to put
657 debugging files into. Enable this option to be able to read and
658 write to these files.
660 For detailed documentation on the debugfs API, see
661 Documentation/filesystems/.
666 prompt "Debugfs default access"
668 default DEBUG_FS_ALLOW_ALL
670 This selects the default access restrictions for debugfs.
671 It can be overridden with kernel command line option
672 debugfs=[on,no-mount,off]. The restrictions apply for API access
673 and filesystem registration.
675 config DEBUG_FS_ALLOW_ALL
678 No restrictions apply. Both API and filesystem registration
679 is on. This is the normal default operation.
681 config DEBUG_FS_DISALLOW_MOUNT
682 bool "Do not register debugfs as filesystem"
684 The API is open but filesystem is not loaded. Clients can still do
685 their work and read with debug tools that do not need
688 config DEBUG_FS_ALLOW_NONE
691 Access is off. Clients get -PERM when trying to create nodes in
692 debugfs tree and debugfs is not registered as a filesystem.
693 Client can then back-off or continue without debugfs access.
697 source "lib/Kconfig.kgdb"
698 source "lib/Kconfig.ubsan"
699 source "lib/Kconfig.kcsan"
703 menu "Networking Debugging"
705 source "net/Kconfig.debug"
707 endmenu # "Networking Debugging"
709 menu "Memory Debugging"
711 source "mm/Kconfig.debug"
714 bool "Debug object operations"
715 depends on DEBUG_KERNEL
717 If you say Y here, additional code will be inserted into the
718 kernel to track the life time of various objects and validate
719 the operations on those objects.
721 config DEBUG_OBJECTS_SELFTEST
722 bool "Debug objects selftest"
723 depends on DEBUG_OBJECTS
725 This enables the selftest of the object debug code.
727 config DEBUG_OBJECTS_FREE
728 bool "Debug objects in freed memory"
729 depends on DEBUG_OBJECTS
731 This enables checks whether a k/v free operation frees an area
732 which contains an object which has not been deactivated
733 properly. This can make kmalloc/kfree-intensive workloads
736 config DEBUG_OBJECTS_TIMERS
737 bool "Debug timer objects"
738 depends on DEBUG_OBJECTS
740 If you say Y here, additional code will be inserted into the
741 timer routines to track the life time of timer objects and
742 validate the timer operations.
744 config DEBUG_OBJECTS_WORK
745 bool "Debug work objects"
746 depends on DEBUG_OBJECTS
748 If you say Y here, additional code will be inserted into the
749 work queue routines to track the life time of work objects and
750 validate the work operations.
752 config DEBUG_OBJECTS_RCU_HEAD
753 bool "Debug RCU callbacks objects"
754 depends on DEBUG_OBJECTS
756 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
758 config DEBUG_OBJECTS_PERCPU_COUNTER
759 bool "Debug percpu counter objects"
760 depends on DEBUG_OBJECTS
762 If you say Y here, additional code will be inserted into the
763 percpu counter routines to track the life time of percpu counter
764 objects and validate the percpu counter operations.
766 config DEBUG_OBJECTS_ENABLE_DEFAULT
767 int "debug_objects bootup default value (0-1)"
770 depends on DEBUG_OBJECTS
772 Debug objects boot parameter default value
774 config SHRINKER_DEBUG
775 bool "Enable shrinker debugging support"
778 Say Y to enable the shrinker debugfs interface which provides
779 visibility into the kernel memory shrinkers subsystem.
780 Disable it to avoid an extra memory footprint.
782 config DEBUG_STACK_USAGE
783 bool "Stack utilization instrumentation"
784 depends on DEBUG_KERNEL
786 Enables the display of the minimum amount of free stack which each
787 task has ever had available in the sysrq-T and sysrq-P debug output.
788 Also emits a message to dmesg when a process exits if that process
789 used more stack space than previously exiting processes.
791 This option will slow down process creation somewhat.
793 config SCHED_STACK_END_CHECK
794 bool "Detect stack corruption on calls to schedule()"
795 depends on DEBUG_KERNEL
798 This option checks for a stack overrun on calls to schedule().
799 If the stack end location is found to be over written always panic as
800 the content of the corrupted region can no longer be trusted.
801 This is to ensure no erroneous behaviour occurs which could result in
802 data corruption or a sporadic crash at a later stage once the region
803 is examined. The runtime overhead introduced is minimal.
805 config ARCH_HAS_DEBUG_VM_PGTABLE
808 An architecture should select this when it can successfully
809 build and run DEBUG_VM_PGTABLE.
811 config DEBUG_VM_IRQSOFF
812 def_bool DEBUG_VM && !PREEMPT_RT
816 depends on DEBUG_KERNEL
818 Enable this to turn on extended checks in the virtual-memory system
819 that may impact performance.
823 config DEBUG_VM_SHOOT_LAZIES
824 bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
826 depends on MMU_LAZY_TLB_SHOOTDOWN
828 Enable additional IPIs that ensure lazy tlb mm references are removed
829 before the mm is freed.
833 config DEBUG_VM_MAPLE_TREE
834 bool "Debug VM maple trees"
836 select DEBUG_MAPLE_TREE
838 Enable VM maple tree debugging information and extra validations.
843 bool "Debug VM red-black trees"
846 Enable VM red-black tree debugging information and extra validations.
850 config DEBUG_VM_PGFLAGS
851 bool "Debug page-flags operations"
854 Enables extra validation on page flags operations.
858 config DEBUG_VM_PGTABLE
859 bool "Debug arch page table for semantics compliance"
861 depends on ARCH_HAS_DEBUG_VM_PGTABLE
862 default y if DEBUG_VM
864 This option provides a debug method which can be used to test
865 architecture page table helper functions on various platforms in
866 verifying if they comply with expected generic MM semantics. This
867 will help architecture code in making sure that any changes or
868 new additions of these helpers still conform to expected
869 semantics of the generic MM. Platforms will have to opt in for
870 this through ARCH_HAS_DEBUG_VM_PGTABLE.
874 config ARCH_HAS_DEBUG_VIRTUAL
878 bool "Debug VM translations"
879 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
881 Enable some costly sanity checks in virtual to page code. This can
882 catch mistakes with virt_to_page() and friends.
886 config DEBUG_NOMMU_REGIONS
887 bool "Debug the global anon/private NOMMU mapping region tree"
888 depends on DEBUG_KERNEL && !MMU
890 This option causes the global tree of anonymous and private mapping
891 regions to be regularly checked for invalid topology.
893 config DEBUG_MEMORY_INIT
894 bool "Debug memory initialisation" if EXPERT
897 Enable this for additional checks during memory initialisation.
898 The sanity checks verify aspects of the VM such as the memory model
899 and other information provided by the architecture. Verbose
900 information will be printed at KERN_DEBUG loglevel depending
901 on the mminit_loglevel= command-line option.
905 config MEMORY_NOTIFIER_ERROR_INJECT
906 tristate "Memory hotplug notifier error injection module"
907 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
909 This option provides the ability to inject artificial errors to
910 memory hotplug notifier chain callbacks. It is controlled through
911 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
913 If the notifier call chain should be failed with some events
914 notified, write the error code to "actions/<notifier event>/error".
916 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
918 # cd /sys/kernel/debug/notifier-error-inject/memory
919 # echo -12 > actions/MEM_GOING_OFFLINE/error
920 # echo offline > /sys/devices/system/memory/memoryXXX/state
921 bash: echo: write error: Cannot allocate memory
923 To compile this code as a module, choose M here: the module will
924 be called memory-notifier-error-inject.
928 config DEBUG_PER_CPU_MAPS
929 bool "Debug access to per_cpu maps"
930 depends on DEBUG_KERNEL
933 Say Y to verify that the per_cpu map being accessed has
934 been set up. This adds a fair amount of code to kernel memory
935 and decreases performance.
939 config DEBUG_KMAP_LOCAL
940 bool "Debug kmap_local temporary mappings"
941 depends on DEBUG_KERNEL && KMAP_LOCAL
943 This option enables additional error checking for the kmap_local
944 infrastructure. Disable for production use.
946 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
949 config DEBUG_KMAP_LOCAL_FORCE_MAP
950 bool "Enforce kmap_local temporary mappings"
951 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
953 select DEBUG_KMAP_LOCAL
955 This option enforces temporary mappings through the kmap_local
956 mechanism for non-highmem pages and on non-highmem systems.
957 Disable this for production systems!
960 bool "Highmem debugging"
961 depends on DEBUG_KERNEL && HIGHMEM
962 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
963 select DEBUG_KMAP_LOCAL
965 This option enables additional error checking for high memory
966 systems. Disable for production systems.
968 config HAVE_DEBUG_STACKOVERFLOW
971 config DEBUG_STACKOVERFLOW
972 bool "Check for stack overflows"
973 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
975 Say Y here if you want to check for overflows of kernel, IRQ
976 and exception stacks (if your architecture uses them). This
977 option will show detailed messages if free stack space drops
978 below a certain limit.
980 These kinds of bugs usually occur when call-chains in the
981 kernel get too deep, especially when interrupts are
984 Use this in cases where you see apparently random memory
985 corruption, especially if it appears in 'struct thread_info'
987 If in doubt, say "N".
993 config MEM_ALLOC_PROFILING
994 bool "Enable memory allocation profiling"
997 depends on !DEBUG_FORCE_WEAK_PER_CPU
999 select PAGE_EXTENSION
1002 Track allocation source code and record total allocation size
1003 initiated at that code location. The mechanism can be used to track
1004 memory leaks with a low performance and memory impact.
1006 config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
1007 bool "Enable memory allocation profiling by default"
1009 depends on MEM_ALLOC_PROFILING
1011 config MEM_ALLOC_PROFILING_DEBUG
1012 bool "Memory allocation profiler debugging"
1014 depends on MEM_ALLOC_PROFILING
1015 select MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
1017 Adds warnings with helpful error messages for memory allocation
1020 source "lib/Kconfig.kasan"
1021 source "lib/Kconfig.kfence"
1022 source "lib/Kconfig.kmsan"
1024 endmenu # "Memory Debugging"
1027 bool "Debug shared IRQ handlers"
1028 depends on DEBUG_KERNEL
1030 Enable this to generate a spurious interrupt just before a shared
1031 interrupt handler is deregistered (generating one when registering
1032 is currently disabled). Drivers need to handle this correctly. Some
1033 don't and need to be caught.
1035 menu "Debug Oops, Lockups and Hangs"
1037 config PANIC_ON_OOPS
1038 bool "Panic on Oops"
1040 Say Y here to enable the kernel to panic when it oopses. This
1041 has the same effect as setting oops=panic on the kernel command
1044 This feature is useful to ensure that the kernel does not do
1045 anything erroneous after an oops which could result in data
1046 corruption or other issues.
1050 config PANIC_ON_OOPS_VALUE
1053 default 0 if !PANIC_ON_OOPS
1054 default 1 if PANIC_ON_OOPS
1056 config PANIC_TIMEOUT
1060 Set the timeout value (in seconds) until a reboot occurs when
1061 the kernel panics. If n = 0, then we wait forever. A timeout
1062 value n > 0 will wait n seconds before rebooting, while a timeout
1063 value n < 0 will reboot immediately. This setting can be overridden
1064 with the kernel command line option panic=, and from userspace via
1065 /proc/sys/kernel/panic.
1067 config LOCKUP_DETECTOR
1070 config SOFTLOCKUP_DETECTOR
1071 bool "Detect Soft Lockups"
1072 depends on DEBUG_KERNEL && !S390
1073 select LOCKUP_DETECTOR
1075 Say Y here to enable the kernel to act as a watchdog to detect
1078 Softlockups are bugs that cause the kernel to loop in kernel
1079 mode for more than 20 seconds, without giving other tasks a
1080 chance to run. The current stack trace is displayed upon
1081 detection and the system will stay locked up.
1083 config SOFTLOCKUP_DETECTOR_INTR_STORM
1084 bool "Detect Interrupt Storm in Soft Lockups"
1085 depends on SOFTLOCKUP_DETECTOR && IRQ_TIME_ACCOUNTING
1086 select GENERIC_IRQ_STAT_SNAPSHOT
1087 default y if NR_CPUS <= 128
1089 Say Y here to enable the kernel to detect interrupt storm
1090 during "soft lockups".
1092 "soft lockups" can be caused by a variety of reasons. If one is
1093 caused by an interrupt storm, then the storming interrupts will not
1094 be on the callstack. To detect this case, it is necessary to report
1095 the CPU stats and the interrupt counts during the "soft lockups".
1097 config BOOTPARAM_SOFTLOCKUP_PANIC
1098 bool "Panic (Reboot) On Soft Lockups"
1099 depends on SOFTLOCKUP_DETECTOR
1101 Say Y here to enable the kernel to panic on "soft lockups",
1102 which are bugs that cause the kernel to loop in kernel
1103 mode for more than 20 seconds (configurable using the watchdog_thresh
1104 sysctl), without giving other tasks a chance to run.
1106 The panic can be used in combination with panic_timeout,
1107 to cause the system to reboot automatically after a
1108 lockup has been detected. This feature is useful for
1109 high-availability systems that have uptime guarantees and
1110 where a lockup must be resolved ASAP.
1114 config HAVE_HARDLOCKUP_DETECTOR_BUDDY
1120 # Global switch whether to build a hardlockup detector at all. It is available
1121 # only when the architecture supports at least one implementation. There are
1122 # two exceptions. The hardlockup detector is never enabled on:
1124 # s390: it reported many false positives there
1126 # sparc64: has a custom implementation which is not using the common
1127 # hardlockup command line options and sysctl interface.
1129 config HARDLOCKUP_DETECTOR
1130 bool "Detect Hard Lockups"
1131 depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
1132 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1133 imply HARDLOCKUP_DETECTOR_PERF
1134 imply HARDLOCKUP_DETECTOR_BUDDY
1135 imply HARDLOCKUP_DETECTOR_ARCH
1136 select LOCKUP_DETECTOR
1139 Say Y here to enable the kernel to act as a watchdog to detect
1142 Hardlockups are bugs that cause the CPU to loop in kernel mode
1143 for more than 10 seconds, without letting other interrupts have a
1144 chance to run. The current stack trace is displayed upon detection
1145 and the system will stay locked up.
1148 # Note that arch-specific variants are always preferred.
1150 config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1151 bool "Prefer the buddy CPU hardlockup detector"
1152 depends on HARDLOCKUP_DETECTOR
1153 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
1154 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1156 Say Y here to prefer the buddy hardlockup detector over the perf one.
1158 With the buddy detector, each CPU uses its softlockup hrtimer
1159 to check that the next CPU is processing hrtimer interrupts by
1160 verifying that a counter is increasing.
1162 This hardlockup detector is useful on systems that don't have
1163 an arch-specific hardlockup detector or if resources needed
1164 for the hardlockup detector are better used for other things.
1166 config HARDLOCKUP_DETECTOR_PERF
1168 depends on HARDLOCKUP_DETECTOR
1169 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
1170 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1171 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1173 config HARDLOCKUP_DETECTOR_BUDDY
1175 depends on HARDLOCKUP_DETECTOR
1176 depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1177 depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
1178 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1179 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1181 config HARDLOCKUP_DETECTOR_ARCH
1183 depends on HARDLOCKUP_DETECTOR
1184 depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1186 The arch-specific implementation of the hardlockup detector will
1190 # Both the "perf" and "buddy" hardlockup detectors count hrtimer
1191 # interrupts. This config enables functions managing this common code.
1193 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1195 select SOFTLOCKUP_DETECTOR
1198 # Enables a timestamp based low pass filter to compensate for perf based
1199 # hard lockup detection which runs too fast due to turbo modes.
1201 config HARDLOCKUP_CHECK_TIMESTAMP
1204 config BOOTPARAM_HARDLOCKUP_PANIC
1205 bool "Panic (Reboot) On Hard Lockups"
1206 depends on HARDLOCKUP_DETECTOR
1208 Say Y here to enable the kernel to panic on "hard lockups",
1209 which are bugs that cause the kernel to loop in kernel
1210 mode with interrupts disabled for more than 10 seconds (configurable
1211 using the watchdog_thresh sysctl).
1215 config DETECT_HUNG_TASK
1216 bool "Detect Hung Tasks"
1217 depends on DEBUG_KERNEL
1218 default SOFTLOCKUP_DETECTOR
1220 Say Y here to enable the kernel to detect "hung tasks",
1221 which are bugs that cause the task to be stuck in
1222 uninterruptible "D" state indefinitely.
1224 When a hung task is detected, the kernel will print the
1225 current stack trace (which you should report), but the
1226 task will stay in uninterruptible state. If lockdep is
1227 enabled then all held locks will also be reported. This
1228 feature has negligible overhead.
1230 config DEFAULT_HUNG_TASK_TIMEOUT
1231 int "Default timeout for hung task detection (in seconds)"
1232 depends on DETECT_HUNG_TASK
1235 This option controls the default timeout (in seconds) used
1236 to determine when a task has become non-responsive and should
1239 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1240 sysctl or by writing a value to
1241 /proc/sys/kernel/hung_task_timeout_secs.
1243 A timeout of 0 disables the check. The default is two minutes.
1244 Keeping the default should be fine in most cases.
1246 config BOOTPARAM_HUNG_TASK_PANIC
1247 bool "Panic (Reboot) On Hung Tasks"
1248 depends on DETECT_HUNG_TASK
1250 Say Y here to enable the kernel to panic on "hung tasks",
1251 which are bugs that cause the kernel to leave a task stuck
1252 in uninterruptible "D" state.
1254 The panic can be used in combination with panic_timeout,
1255 to cause the system to reboot automatically after a
1256 hung task has been detected. This feature is useful for
1257 high-availability systems that have uptime guarantees and
1258 where a hung tasks must be resolved ASAP.
1263 bool "Detect Workqueue Stalls"
1264 depends on DEBUG_KERNEL
1266 Say Y here to enable stall detection on workqueues. If a
1267 worker pool doesn't make forward progress on a pending work
1268 item for over a given amount of time, 30s by default, a
1269 warning message is printed along with dump of workqueue
1270 state. This can be configured through kernel parameter
1271 "workqueue.watchdog_thresh" and its sysfs counterpart.
1273 config WQ_CPU_INTENSIVE_REPORT
1274 bool "Report per-cpu work items which hog CPU for too long"
1275 depends on DEBUG_KERNEL
1277 Say Y here to enable reporting of concurrency-managed per-cpu work
1278 items that hog CPUs for longer than
1279 workqueue.cpu_intensive_thresh_us. Workqueue automatically
1280 detects and excludes them from concurrency management to prevent
1281 them from stalling other per-cpu work items. Occassional
1282 triggering may not necessarily indicate a problem. Repeated
1283 triggering likely indicates that the work item should be switched
1284 to use an unbound workqueue.
1287 tristate "Test module to generate lockups"
1290 This builds the "test_lockup" module that helps to make sure
1291 that watchdogs and lockup detectors are working properly.
1293 Depending on module parameters it could emulate soft or hard
1294 lockup, "hung task", or locking arbitrary lock for a long time.
1295 Also it could generate series of lockups with cooling-down periods.
1299 endmenu # "Debug lockups and hangs"
1301 menu "Scheduler Debugging"
1304 bool "Collect scheduler debugging info"
1305 depends on DEBUG_KERNEL && DEBUG_FS
1308 If you say Y here, the /sys/kernel/debug/sched file will be provided
1309 that can help debug the scheduler. The runtime overhead of this
1317 bool "Collect scheduler statistics"
1321 If you say Y here, additional code will be inserted into the
1322 scheduler and related routines to collect statistics about
1323 scheduler behavior and provide them in /proc/schedstat. These
1324 stats may be useful for both tuning and debugging the scheduler
1325 If you aren't debugging the scheduler or trying to tune a specific
1326 application, you can say N to avoid the very slight overhead
1331 config DEBUG_PREEMPT
1332 bool "Debug preemptible kernel"
1333 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1335 If you say Y here then the kernel will use a debug variant of the
1336 commonly used smp_processor_id() function and will print warnings
1337 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1338 will detect preemption count underflows.
1340 This option has potential to introduce high runtime overhead,
1341 depending on workload as it triggers debugging routines for each
1342 this_cpu operation. It should only be used for debugging purposes.
1344 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1346 config LOCK_DEBUGGING_SUPPORT
1348 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1351 config PROVE_LOCKING
1352 bool "Lock debugging: prove locking correctness"
1353 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1355 select DEBUG_SPINLOCK
1356 select DEBUG_MUTEXES if !PREEMPT_RT
1357 select DEBUG_RT_MUTEXES if RT_MUTEXES
1358 select DEBUG_RWSEMS if !PREEMPT_RT
1359 select DEBUG_WW_MUTEX_SLOWPATH
1360 select DEBUG_LOCK_ALLOC
1361 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1362 select TRACE_IRQFLAGS
1365 This feature enables the kernel to prove that all locking
1366 that occurs in the kernel runtime is mathematically
1367 correct: that under no circumstance could an arbitrary (and
1368 not yet triggered) combination of observed locking
1369 sequences (on an arbitrary number of CPUs, running an
1370 arbitrary number of tasks and interrupt contexts) cause a
1373 In short, this feature enables the kernel to report locking
1374 related deadlocks before they actually occur.
1376 The proof does not depend on how hard and complex a
1377 deadlock scenario would be to trigger: how many
1378 participant CPUs, tasks and irq-contexts would be needed
1379 for it to trigger. The proof also does not depend on
1380 timing: if a race and a resulting deadlock is possible
1381 theoretically (no matter how unlikely the race scenario
1382 is), it will be proven so and will immediately be
1383 reported by the kernel (once the event is observed that
1384 makes the deadlock theoretically possible).
1386 If a deadlock is impossible (i.e. the locking rules, as
1387 observed by the kernel, are mathematically correct), the
1388 kernel reports nothing.
1390 NOTE: this feature can also be enabled for rwlocks, mutexes
1391 and rwsems - in which case all dependencies between these
1392 different locking variants are observed and mapped too, and
1393 the proof of observed correctness is also maintained for an
1394 arbitrary combination of these separate locking variants.
1396 For more details, see Documentation/locking/lockdep-design.rst.
1398 config PROVE_RAW_LOCK_NESTING
1400 depends on PROVE_LOCKING
1403 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1404 that the lock nesting rules for PREEMPT_RT enabled kernels are
1408 bool "Lock usage statistics"
1409 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1411 select DEBUG_SPINLOCK
1412 select DEBUG_MUTEXES if !PREEMPT_RT
1413 select DEBUG_RT_MUTEXES if RT_MUTEXES
1414 select DEBUG_LOCK_ALLOC
1417 This feature enables tracking lock contention points
1419 For more details, see Documentation/locking/lockstat.rst
1421 This also enables lock events required by "perf lock",
1423 If you want to use "perf lock", you also need to turn on
1424 CONFIG_EVENT_TRACING.
1426 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1427 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1429 config DEBUG_RT_MUTEXES
1430 bool "RT Mutex debugging, deadlock detection"
1431 depends on DEBUG_KERNEL && RT_MUTEXES
1433 This allows rt mutex semantics violations and rt mutex related
1434 deadlocks (lockups) to be detected and reported automatically.
1436 config DEBUG_SPINLOCK
1437 bool "Spinlock and rw-lock debugging: basic checks"
1438 depends on DEBUG_KERNEL
1439 select UNINLINE_SPIN_UNLOCK
1441 Say Y here and build SMP to catch missing spinlock initialization
1442 and certain other kinds of spinlock errors commonly made. This is
1443 best used in conjunction with the NMI watchdog so that spinlock
1444 deadlocks are also debuggable.
1446 config DEBUG_MUTEXES
1447 bool "Mutex debugging: basic checks"
1448 depends on DEBUG_KERNEL && !PREEMPT_RT
1450 This feature allows mutex semantics violations to be detected and
1453 config DEBUG_WW_MUTEX_SLOWPATH
1454 bool "Wait/wound mutex debugging: Slowpath testing"
1455 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1456 select DEBUG_LOCK_ALLOC
1457 select DEBUG_SPINLOCK
1458 select DEBUG_MUTEXES if !PREEMPT_RT
1459 select DEBUG_RT_MUTEXES if PREEMPT_RT
1461 This feature enables slowpath testing for w/w mutex users by
1462 injecting additional -EDEADLK wound/backoff cases. Together with
1463 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1464 will test all possible w/w mutex interface abuse with the
1465 exception of simply not acquiring all the required locks.
1466 Note that this feature can introduce significant overhead, so
1467 it really should not be enabled in a production or distro kernel,
1468 even a debug kernel. If you are a driver writer, enable it. If
1469 you are a distro, do not.
1472 bool "RW Semaphore debugging: basic checks"
1473 depends on DEBUG_KERNEL && !PREEMPT_RT
1475 This debugging feature allows mismatched rw semaphore locks
1476 and unlocks to be detected and reported.
1478 config DEBUG_LOCK_ALLOC
1479 bool "Lock debugging: detect incorrect freeing of live locks"
1480 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1481 select DEBUG_SPINLOCK
1482 select DEBUG_MUTEXES if !PREEMPT_RT
1483 select DEBUG_RT_MUTEXES if RT_MUTEXES
1486 This feature will check whether any held lock (spinlock, rwlock,
1487 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1488 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1489 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1490 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1491 held during task exit.
1495 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 config LOCKDEP_SMALL
1504 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1505 depends on LOCKDEP && !LOCKDEP_SMALL
1509 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1511 config LOCKDEP_CHAINS_BITS
1512 int "Bitsize for MAX_LOCKDEP_CHAINS"
1513 depends on LOCKDEP && !LOCKDEP_SMALL
1517 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1519 config LOCKDEP_STACK_TRACE_BITS
1520 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1521 depends on LOCKDEP && !LOCKDEP_SMALL
1525 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1527 config LOCKDEP_STACK_TRACE_HASH_BITS
1528 int "Bitsize for STACK_TRACE_HASH_SIZE"
1529 depends on LOCKDEP && !LOCKDEP_SMALL
1533 Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1535 config LOCKDEP_CIRCULAR_QUEUE_BITS
1536 int "Bitsize for elements in circular_queue struct"
1541 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1543 config DEBUG_LOCKDEP
1544 bool "Lock dependency engine debugging"
1545 depends on DEBUG_KERNEL && LOCKDEP
1546 select DEBUG_IRQFLAGS
1548 If you say Y here, the lock dependency engine will do
1549 additional runtime checks to debug itself, at the price
1550 of more runtime overhead.
1552 config DEBUG_ATOMIC_SLEEP
1553 bool "Sleep inside atomic section checking"
1554 select PREEMPT_COUNT
1555 depends on DEBUG_KERNEL
1556 depends on !ARCH_NO_PREEMPT
1558 If you say Y here, various routines which may sleep will become very
1559 noisy if they are called inside atomic sections: when a spinlock is
1560 held, inside an rcu read side critical section, inside preempt disabled
1561 sections, inside an interrupt, etc...
1563 config DEBUG_LOCKING_API_SELFTESTS
1564 bool "Locking API boot-time self-tests"
1565 depends on DEBUG_KERNEL
1567 Say Y here if you want the kernel to run a short self-test during
1568 bootup. The self-test checks whether common types of locking bugs
1569 are detected by debugging mechanisms or not. (if you disable
1570 lock debugging then those bugs won't be detected of course.)
1571 The following locking APIs are covered: spinlocks, rwlocks,
1574 config LOCK_TORTURE_TEST
1575 tristate "torture tests for locking"
1576 depends on DEBUG_KERNEL
1579 This option provides a kernel module that runs torture tests
1580 on kernel locking primitives. The kernel module may be built
1581 after the fact on the running kernel to be tested, if desired.
1583 Say Y here if you want kernel locking-primitive torture tests
1584 to be built into the kernel.
1585 Say M if you want these torture tests to build as a module.
1586 Say N if you are unsure.
1588 config WW_MUTEX_SELFTEST
1589 tristate "Wait/wound mutex selftests"
1591 This option provides a kernel module that runs tests on the
1592 on the struct ww_mutex locking API.
1594 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1595 with this test harness.
1597 Say M if you want these self tests to build as a module.
1598 Say N if you are unsure.
1600 config SCF_TORTURE_TEST
1601 tristate "torture tests for smp_call_function*()"
1602 depends on DEBUG_KERNEL
1605 This option provides a kernel module that runs torture tests
1606 on the smp_call_function() family of primitives. The kernel
1607 module may be built after the fact on the running kernel to
1608 be tested, if desired.
1610 config CSD_LOCK_WAIT_DEBUG
1611 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1612 depends on DEBUG_KERNEL
1617 This option enables debug prints when CPUs are slow to respond
1618 to the smp_call_function*() IPI wrappers. These debug prints
1619 include the IPI handler function currently executing (if any)
1620 and relevant stack traces.
1622 config CSD_LOCK_WAIT_DEBUG_DEFAULT
1623 bool "Default csd_lock_wait() debugging on at boot time"
1624 depends on CSD_LOCK_WAIT_DEBUG
1628 This option causes the csdlock_debug= kernel boot parameter to
1629 default to 1 (basic debugging) instead of 0 (no debugging).
1631 endmenu # lock debugging
1633 config TRACE_IRQFLAGS
1634 depends on TRACE_IRQFLAGS_SUPPORT
1637 Enables hooks to interrupt enabling and disabling for
1638 either tracing or lock debugging.
1640 config TRACE_IRQFLAGS_NMI
1642 depends on TRACE_IRQFLAGS
1643 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1645 config NMI_CHECK_CPU
1646 bool "Debugging for CPUs failing to respond to backtrace requests"
1647 depends on DEBUG_KERNEL
1651 Enables debug prints when a CPU fails to respond to a given
1652 backtrace NMI. These prints provide some reasons why a CPU
1653 might legitimately be failing to respond, for example, if it
1654 is offline of if ignore_nmis is set.
1656 config DEBUG_IRQFLAGS
1657 bool "Debug IRQ flag manipulation"
1659 Enables checks for potentially unsafe enabling or disabling of
1660 interrupts, such as calling raw_local_irq_restore() when interrupts
1664 bool "Stack backtrace support"
1665 depends on STACKTRACE_SUPPORT
1667 This option causes the kernel to create a /proc/pid/stack for
1668 every process, showing its current stack trace.
1669 It is also used by various kernel debugging features that require
1670 stack trace generation.
1672 config WARN_ALL_UNSEEDED_RANDOM
1673 bool "Warn for all uses of unseeded randomness"
1676 Some parts of the kernel contain bugs relating to their use of
1677 cryptographically secure random numbers before it's actually possible
1678 to generate those numbers securely. This setting ensures that these
1679 flaws don't go unnoticed, by enabling a message, should this ever
1680 occur. This will allow people with obscure setups to know when things
1681 are going wrong, so that they might contact developers about fixing
1684 Unfortunately, on some models of some architectures getting
1685 a fully seeded CRNG is extremely difficult, and so this can
1686 result in dmesg getting spammed for a surprisingly long
1687 time. This is really bad from a security perspective, and
1688 so architecture maintainers really need to do what they can
1689 to get the CRNG seeded sooner after the system is booted.
1690 However, since users cannot do anything actionable to
1691 address this, by default this option is disabled.
1693 Say Y here if you want to receive warnings for all uses of
1694 unseeded randomness. This will be of use primarily for
1695 those developers interested in improving the security of
1696 Linux kernels running on their architecture (or
1699 config DEBUG_KOBJECT
1700 bool "kobject debugging"
1701 depends on DEBUG_KERNEL
1703 If you say Y here, some extra kobject debugging messages will be sent
1706 config DEBUG_KOBJECT_RELEASE
1707 bool "kobject release debugging"
1708 depends on DEBUG_OBJECTS_TIMERS
1710 kobjects are reference counted objects. This means that their
1711 last reference count put is not predictable, and the kobject can
1712 live on past the point at which a driver decides to drop its
1713 initial reference to the kobject gained on allocation. An
1714 example of this would be a struct device which has just been
1717 However, some buggy drivers assume that after such an operation,
1718 the memory backing the kobject can be immediately freed. This
1719 goes completely against the principles of a refcounted object.
1721 If you say Y here, the kernel will delay the release of kobjects
1722 on the last reference count to improve the visibility of this
1723 kind of kobject release bug.
1725 config HAVE_DEBUG_BUGVERBOSE
1728 menu "Debug kernel data structures"
1731 bool "Debug linked list manipulation"
1732 depends on DEBUG_KERNEL
1733 select LIST_HARDENED
1735 Enable this to turn on extended checks in the linked-list walking
1738 This option trades better quality error reports for performance, and
1739 is more suitable for kernel debugging. If you care about performance,
1740 you should only enable CONFIG_LIST_HARDENED instead.
1745 bool "Debug priority linked list manipulation"
1746 depends on DEBUG_KERNEL
1748 Enable this to turn on extended checks in the priority-ordered
1749 linked-list (plist) walking routines. This checks the entire
1750 list multiple times during each manipulation.
1755 bool "Debug SG table operations"
1756 depends on DEBUG_KERNEL
1758 Enable this to turn on checks on scatter-gather tables. This can
1759 help find problems with drivers that do not properly initialize
1764 config DEBUG_NOTIFIERS
1765 bool "Debug notifier call chains"
1766 depends on DEBUG_KERNEL
1768 Enable this to turn on sanity checking for notifier call chains.
1769 This is most useful for kernel developers to make sure that
1770 modules properly unregister themselves from notifier chains.
1771 This is a relatively cheap check but if you care about maximum
1774 config DEBUG_CLOSURES
1775 bool "Debug closures (bcache async widgits)"
1779 Keeps all active closures in a linked list and provides a debugfs
1780 interface to list them, which makes it possible to see asynchronous
1781 operations that get stuck.
1783 config DEBUG_MAPLE_TREE
1784 bool "Debug maple trees"
1785 depends on DEBUG_KERNEL
1787 Enable maple tree debugging information and extra validations.
1793 source "kernel/rcu/Kconfig.debug"
1795 config DEBUG_WQ_FORCE_RR_CPU
1796 bool "Force round-robin CPU selection for unbound work items"
1797 depends on DEBUG_KERNEL
1800 Workqueue used to implicitly guarantee that work items queued
1801 without explicit CPU specified are put on the local CPU. This
1802 guarantee is no longer true and while local CPU is still
1803 preferred work items may be put on foreign CPUs. Kernel
1804 parameter "workqueue.debug_force_rr_cpu" is added to force
1805 round-robin CPU selection to flush out usages which depend on the
1806 now broken guarantee. This config option enables the debug
1807 feature by default. When enabled, memory and cache locality will
1810 config CPU_HOTPLUG_STATE_CONTROL
1811 bool "Enable CPU hotplug state control"
1812 depends on DEBUG_KERNEL
1813 depends on HOTPLUG_CPU
1816 Allows to write steps between "offline" and "online" to the CPUs
1817 sysfs target file so states can be stepped granular. This is a debug
1818 option for now as the hotplug machinery cannot be stopped and
1819 restarted at arbitrary points yet.
1821 Say N if your are unsure.
1824 bool "Latency measuring infrastructure"
1825 depends on DEBUG_KERNEL
1826 depends on STACKTRACE_SUPPORT
1828 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1834 Enable this option if you want to use the LatencyTOP tool
1835 to find out which userspace is blocking on what kernel operations.
1837 config DEBUG_CGROUP_REF
1838 bool "Disable inlining of cgroup css reference count functions"
1839 depends on DEBUG_KERNEL
1844 Force cgroup css reference count functions to not be inlined so
1845 that they can be kprobed for debugging.
1847 source "kernel/trace/Kconfig"
1849 config PROVIDE_OHCI1394_DMA_INIT
1850 bool "Remote debugging over FireWire early on boot"
1851 depends on PCI && X86
1853 If you want to debug problems which hang or crash the kernel early
1854 on boot and the crashing machine has a FireWire port, you can use
1855 this feature to remotely access the memory of the crashed machine
1856 over FireWire. This employs remote DMA as part of the OHCI1394
1857 specification which is now the standard for FireWire controllers.
1859 With remote DMA, you can monitor the printk buffer remotely using
1860 firescope and access all memory below 4GB using fireproxy from gdb.
1861 Even controlling a kernel debugger is possible using remote DMA.
1865 If ohci1394_dma=early is used as boot parameter, it will initialize
1866 all OHCI1394 controllers which are found in the PCI config space.
1868 As all changes to the FireWire bus such as enabling and disabling
1869 devices cause a bus reset and thereby disable remote DMA for all
1870 devices, be sure to have the cable plugged and FireWire enabled on
1871 the debugging host before booting the debug target for debugging.
1873 This code (~1k) is freed after boot. By then, the firewire stack
1874 in charge of the OHCI-1394 controllers should be used instead.
1876 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1878 source "samples/Kconfig"
1880 config ARCH_HAS_DEVMEM_IS_ALLOWED
1883 config STRICT_DEVMEM
1884 bool "Filter access to /dev/mem"
1885 depends on MMU && DEVMEM
1886 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1887 default y if PPC || X86 || ARM64 || S390
1889 If this option is disabled, you allow userspace (root) access to all
1890 of memory, including kernel and userspace memory. Accidental
1891 access to this is obviously disastrous, but specific access can
1892 be used by people debugging the kernel. Note that with PAT support
1893 enabled, even in this case there are restrictions on /dev/mem
1894 use due to the cache aliasing requirements.
1896 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1897 file only allows userspace access to PCI space and the BIOS code and
1898 data regions. This is sufficient for dosemu and X and all common
1903 config IO_STRICT_DEVMEM
1904 bool "Filter I/O access to /dev/mem"
1905 depends on STRICT_DEVMEM
1907 If this option is disabled, you allow userspace (root) access to all
1908 io-memory regardless of whether a driver is actively using that
1909 range. Accidental access to this is obviously disastrous, but
1910 specific access can be used by people debugging kernel drivers.
1912 If this option is switched on, the /dev/mem file only allows
1913 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1914 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1915 if the driver using a given range cannot be disabled.
1919 menu "$(SRCARCH) Debugging"
1921 source "arch/$(SRCARCH)/Kconfig.debug"
1925 menu "Kernel Testing and Coverage"
1927 source "lib/kunit/Kconfig"
1929 config NOTIFIER_ERROR_INJECTION
1930 tristate "Notifier error injection"
1931 depends on DEBUG_KERNEL
1934 This option provides the ability to inject artificial errors to
1935 specified notifier chain callbacks. It is useful to test the error
1936 handling of notifier call chain failures.
1940 config PM_NOTIFIER_ERROR_INJECT
1941 tristate "PM notifier error injection module"
1942 depends on PM && NOTIFIER_ERROR_INJECTION
1943 default m if PM_DEBUG
1945 This option provides the ability to inject artificial errors to
1946 PM notifier chain callbacks. It is controlled through debugfs
1947 interface /sys/kernel/debug/notifier-error-inject/pm
1949 If the notifier call chain should be failed with some events
1950 notified, write the error code to "actions/<notifier event>/error".
1952 Example: Inject PM suspend error (-12 = -ENOMEM)
1954 # cd /sys/kernel/debug/notifier-error-inject/pm/
1955 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1956 # echo mem > /sys/power/state
1957 bash: echo: write error: Cannot allocate memory
1959 To compile this code as a module, choose M here: the module will
1960 be called pm-notifier-error-inject.
1964 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1965 tristate "OF reconfig notifier error injection module"
1966 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1968 This option provides the ability to inject artificial errors to
1969 OF reconfig notifier chain callbacks. It is controlled
1970 through debugfs interface under
1971 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1973 If the notifier call chain should be failed with some events
1974 notified, write the error code to "actions/<notifier event>/error".
1976 To compile this code as a module, choose M here: the module will
1977 be called of-reconfig-notifier-error-inject.
1981 config NETDEV_NOTIFIER_ERROR_INJECT
1982 tristate "Netdev notifier error injection module"
1983 depends on NET && NOTIFIER_ERROR_INJECTION
1985 This option provides the ability to inject artificial errors to
1986 netdevice notifier chain callbacks. It is controlled through debugfs
1987 interface /sys/kernel/debug/notifier-error-inject/netdev
1989 If the notifier call chain should be failed with some events
1990 notified, write the error code to "actions/<notifier event>/error".
1992 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1994 # cd /sys/kernel/debug/notifier-error-inject/netdev
1995 # echo -22 > actions/NETDEV_CHANGEMTU/error
1996 # ip link set eth0 mtu 1024
1997 RTNETLINK answers: Invalid argument
1999 To compile this code as a module, choose M here: the module will
2000 be called netdev-notifier-error-inject.
2004 config FUNCTION_ERROR_INJECTION
2005 bool "Fault-injections of functions"
2006 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2008 Add fault injections into various functions that are annotated with
2009 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
2010 value of these functions. This is useful to test error paths of code.
2014 config FAULT_INJECTION
2015 bool "Fault-injection framework"
2016 depends on DEBUG_KERNEL
2018 Provide fault-injection framework.
2019 For more details, see Documentation/fault-injection/.
2022 bool "Fault-injection capability for kmalloc"
2023 depends on FAULT_INJECTION
2025 Provide fault-injection capability for kmalloc.
2027 config FAIL_PAGE_ALLOC
2028 bool "Fault-injection capability for alloc_pages()"
2029 depends on FAULT_INJECTION
2031 Provide fault-injection capability for alloc_pages().
2033 config FAULT_INJECTION_USERCOPY
2034 bool "Fault injection capability for usercopy functions"
2035 depends on FAULT_INJECTION
2037 Provides fault-injection capability to inject failures
2038 in usercopy functions (copy_from_user(), get_user(), ...).
2040 config FAIL_MAKE_REQUEST
2041 bool "Fault-injection capability for disk IO"
2042 depends on FAULT_INJECTION && BLOCK
2044 Provide fault-injection capability for disk IO.
2046 config FAIL_IO_TIMEOUT
2047 bool "Fault-injection capability for faking disk interrupts"
2048 depends on FAULT_INJECTION && BLOCK
2050 Provide fault-injection capability on end IO handling. This
2051 will make the block layer "forget" an interrupt as configured,
2052 thus exercising the error handling.
2054 Only works with drivers that use the generic timeout handling,
2055 for others it won't do anything.
2058 bool "Fault-injection capability for futexes"
2060 depends on FAULT_INJECTION && FUTEX
2062 Provide fault-injection capability for futexes.
2064 config FAULT_INJECTION_DEBUG_FS
2065 bool "Debugfs entries for fault-injection capabilities"
2066 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2068 Enable configuration of fault-injection capabilities via debugfs.
2070 config FAIL_FUNCTION
2071 bool "Fault-injection capability for functions"
2072 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2074 Provide function-based fault-injection capability.
2075 This will allow you to override a specific function with a return
2076 with given return value. As a result, function caller will see
2077 an error value and have to handle it. This is useful to test the
2078 error handling in various subsystems.
2080 config FAIL_MMC_REQUEST
2081 bool "Fault-injection capability for MMC IO"
2082 depends on FAULT_INJECTION_DEBUG_FS && MMC
2084 Provide fault-injection capability for MMC IO.
2085 This will make the mmc core return data errors. This is
2086 useful to test the error handling in the mmc block device
2087 and to test how the mmc host driver handles retries from
2091 bool "Fault-injection capability for SunRPC"
2092 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2094 Provide fault-injection capability for SunRPC and
2097 config FAIL_SKB_REALLOC
2098 bool "Fault-injection capability forcing skb to reallocate"
2099 depends on FAULT_INJECTION_DEBUG_FS
2101 Provide fault-injection capability that forces the skb to be
2102 reallocated, catching possible invalid pointers to the skb.
2104 For more information, check
2105 Documentation/dev-tools/fault-injection/fault-injection.rst
2107 config FAULT_INJECTION_CONFIGFS
2108 bool "Configfs interface for fault-injection capabilities"
2109 depends on FAULT_INJECTION
2112 This option allows configfs-based drivers to dynamically configure
2113 fault-injection via configfs. Each parameter for driver-specific
2114 fault-injection can be made visible as a configfs attribute in a
2118 config FAULT_INJECTION_STACKTRACE_FILTER
2119 bool "stacktrace filter for fault-injection capabilities"
2120 depends on FAULT_INJECTION
2121 depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
2123 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2125 Provide stacktrace filter for fault-injection capabilities
2127 config ARCH_HAS_KCOV
2130 An architecture should select this when it can successfully
2131 build and run with CONFIG_KCOV. This typically requires
2132 disabling instrumentation for some early boot code.
2134 config CC_HAS_SANCOV_TRACE_PC
2135 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2139 bool "Code coverage for fuzzing"
2140 depends on ARCH_HAS_KCOV
2141 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2142 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2143 GCC_VERSION >= 120000 || CC_IS_CLANG
2145 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2146 select OBJTOOL if HAVE_NOINSTR_HACK
2148 KCOV exposes kernel code coverage information in a form suitable
2149 for coverage-guided fuzzing (randomized testing).
2151 For more details, see Documentation/dev-tools/kcov.rst.
2153 config KCOV_ENABLE_COMPARISONS
2154 bool "Enable comparison operands collection by KCOV"
2156 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2158 KCOV also exposes operands of every comparison in the instrumented
2159 code along with operand sizes and PCs of the comparison instructions.
2160 These operands can be used by fuzzing engines to improve the quality
2161 of fuzzing coverage.
2163 config KCOV_INSTRUMENT_ALL
2164 bool "Instrument all code by default"
2168 If you are doing generic system call fuzzing (like e.g. syzkaller),
2169 then you will want to instrument the whole kernel and you should
2170 say y here. If you are doing more targeted fuzzing (like e.g.
2171 filesystem fuzzing with AFL) then you will want to enable coverage
2172 for more specific subsets of files, and should say n here.
2174 config KCOV_IRQ_AREA_SIZE
2175 hex "Size of interrupt coverage collection area in words"
2179 KCOV uses preallocated per-cpu areas to collect coverage from
2180 soft interrupts. This specifies the size of those areas in the
2181 number of unsigned long words.
2183 config KCOV_SELFTEST
2184 bool "Perform short selftests on boot"
2187 Run short KCOV coverage collection selftests on boot.
2188 On test failure, causes the kernel to panic. Recommended to be
2189 enabled, ensuring critical functionality works as intended.
2191 menuconfig RUNTIME_TESTING_MENU
2192 bool "Runtime Testing"
2195 if RUNTIME_TESTING_MENU
2198 tristate "Dhrystone benchmark test"
2200 Enable this to include the Dhrystone 2.1 benchmark. This test
2201 calculates the number of Dhrystones per second, and the number of
2202 DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2203 by 1757 (the number of Dhrystones per second obtained on the VAX
2204 11/780, nominally a 1 MIPS machine).
2206 To run the benchmark, it needs to be enabled explicitly, either from
2207 the kernel command line (when built-in), or from userspace (when
2208 built-in or modular).
2210 Run once during kernel boot:
2214 Set number of iterations from kernel command line:
2216 test_dhry.iterations=<n>
2218 Set number of iterations from userspace:
2220 echo <n> > /sys/module/test_dhry/parameters/iterations
2222 Trigger manual run from userspace:
2224 echo y > /sys/module/test_dhry/parameters/run
2226 If the number of iterations is <= 0, the test will devise a suitable
2227 number of iterations (test runs for at least 2s) automatically.
2228 This process takes ca. 4s.
2233 tristate "Linux Kernel Dump Test Tool Module"
2236 This module enables testing of the different dumping mechanisms by
2237 inducing system failures at predefined crash points.
2238 If you don't need it: say N
2239 Choose M here to compile this code as a module. The module will be
2242 Documentation on how to use the module can be found in
2243 Documentation/fault-injection/provoke-crashes.rst
2245 config CPUMASK_KUNIT_TEST
2246 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2248 default KUNIT_ALL_TESTS
2250 Enable to turn on cpumask tests, running at boot or module load time.
2252 For more information on KUnit and unit tests in general, please refer
2253 to the KUnit documentation in Documentation/dev-tools/kunit/.
2257 config TEST_LIST_SORT
2258 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2260 default KUNIT_ALL_TESTS
2262 Enable this to turn on 'list_sort()' function test. This test is
2263 executed only once during system boot (so affects only boot time),
2264 or at module load time.
2268 config TEST_MIN_HEAP
2269 tristate "Min heap test"
2270 depends on DEBUG_KERNEL || m
2272 Enable this to turn on min heap function tests. This test is
2273 executed only once during system boot (so affects only boot time),
2274 or at module load time.
2279 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2281 default KUNIT_ALL_TESTS
2283 This option enables the self-test function of 'sort()' at boot,
2284 or at module load time.
2289 tristate "64bit/32bit division and modulo test"
2290 depends on DEBUG_KERNEL || m
2292 Enable this to turn on 'do_div()' function test. This test is
2293 executed only once during system boot (so affects only boot time),
2294 or at module load time.
2298 config TEST_MULDIV64
2299 tristate "mul_u64_u64_div_u64() test"
2300 depends on DEBUG_KERNEL || m
2302 Enable this to turn on 'mul_u64_u64_div_u64()' function test.
2303 This test is executed only once during system boot (so affects
2304 only boot time), or at module load time.
2308 config TEST_IOV_ITER
2309 tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2312 default KUNIT_ALL_TESTS
2314 Enable this to turn on testing of the operation of the I/O iterator
2315 (iov_iter). This test is executed only once during system boot (so
2316 affects only boot time), or at module load time.
2320 config KPROBES_SANITY_TEST
2321 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2322 depends on DEBUG_KERNEL
2325 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2326 default KUNIT_ALL_TESTS
2328 This option provides for testing basic kprobes functionality on
2329 boot. Samples of kprobe and kretprobe are inserted and
2330 verified for functionality.
2332 Say N if you are unsure.
2334 config FPROBE_SANITY_TEST
2335 bool "Self test for fprobe"
2336 depends on DEBUG_KERNEL
2340 This option will enable testing the fprobe when the system boot.
2341 A series of tests are made to verify that the fprobe is functioning
2344 Say N if you are unsure.
2346 config BACKTRACE_SELF_TEST
2347 tristate "Self test for the backtrace code"
2348 depends on DEBUG_KERNEL
2350 This option provides a kernel module that can be used to test
2351 the kernel stack backtrace code. This option is not useful
2352 for distributions or general kernels, but only for kernel
2353 developers working on architecture code.
2355 Note that if you want to also test saved backtraces, you will
2356 have to enable STACKTRACE as well.
2358 Say N if you are unsure.
2360 config TEST_REF_TRACKER
2361 tristate "Self test for reference tracker"
2362 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2365 This option provides a kernel module performing tests
2366 using reference tracker infrastructure.
2368 Say N if you are unsure.
2371 tristate "Red-Black tree test"
2372 depends on DEBUG_KERNEL
2374 A benchmark measuring the performance of the rbtree library.
2375 Also includes rbtree invariant checks.
2377 config REED_SOLOMON_TEST
2378 tristate "Reed-Solomon library test"
2379 depends on DEBUG_KERNEL || m
2381 select REED_SOLOMON_ENC16
2382 select REED_SOLOMON_DEC16
2384 This option enables the self-test function of rslib at boot,
2385 or at module load time.
2389 config INTERVAL_TREE_TEST
2390 tristate "Interval tree test"
2391 depends on DEBUG_KERNEL
2392 select INTERVAL_TREE
2394 A benchmark measuring the performance of the interval tree library
2397 tristate "Per cpu operations test"
2398 depends on m && DEBUG_KERNEL
2400 Enable this option to build test module which validates per-cpu
2405 config ATOMIC64_SELFTEST
2406 tristate "Perform an atomic64_t self-test"
2408 Enable this option to test the atomic64_t functions at boot or
2409 at module load time.
2413 config ASYNC_RAID6_TEST
2414 tristate "Self test for hardware accelerated raid6 recovery"
2415 depends on ASYNC_RAID6_RECOV
2418 This is a one-shot self test that permutes through the
2419 recovery of all the possible two disk failure scenarios for a
2420 N-disk array. Recovery is performed with the asynchronous
2421 raid6 recovery routines, and will optionally use an offload
2422 engine if one is available.
2427 tristate "Test functions located in the hexdump module at runtime"
2429 config STRING_KUNIT_TEST
2430 tristate "KUnit test string functions at runtime" if !KUNIT_ALL_TESTS
2432 default KUNIT_ALL_TESTS
2434 config STRING_HELPERS_KUNIT_TEST
2435 tristate "KUnit test string helpers at runtime" if !KUNIT_ALL_TESTS
2437 default KUNIT_ALL_TESTS
2440 tristate "Test kstrto*() family of functions at runtime"
2443 tristate "Test printf() family of functions at runtime"
2446 tristate "Test scanf() family of functions at runtime"
2449 tristate "Test bitmap_*() family of functions at runtime"
2451 Enable this option to test the bitmap functions at boot.
2456 tristate "Test functions located in the uuid module at runtime"
2459 tristate "Test the XArray code at runtime"
2461 config TEST_MAPLE_TREE
2462 tristate "Test the Maple Tree code at runtime or module load"
2464 Enable this option to test the maple tree code functions at boot, or
2465 when the module is loaded. Enable "Debug Maple Trees" will enable
2466 more verbose output on failures.
2470 config TEST_RHASHTABLE
2471 tristate "Perform selftest on resizable hash table"
2473 Enable this option to test the rhashtable functions at boot.
2478 tristate "Perform selftest on IDA functions"
2481 tristate "Perform selftest on priority array manager"
2484 Enable this option to test priority array manager on boot
2489 config TEST_IRQ_TIMINGS
2490 bool "IRQ timings selftest"
2491 depends on IRQ_TIMINGS
2493 Enable this option to test the irq timings code on boot.
2498 tristate "Test module loading with 'hello world' module"
2501 This builds the "test_module" module that emits "Hello, world"
2502 on printk when loaded. It is designed to be used for basic
2503 evaluation of the module loading subsystem (for example when
2504 validating module verification). It lacks any extra dependencies,
2505 and will not normally be loaded by the system unless explicitly
2511 tristate "Test module for compilation of bitops operations"
2513 This builds the "test_bitops" module that is much like the
2514 TEST_LKM module except that it does a basic exercise of the
2515 set/clear_bit macros and get_count_order/long to make sure there are
2516 no compiler warnings from C=1 sparse checker or -Wextra
2517 compilations. It has no dependencies and doesn't run or load unless
2518 explicitly requested by name. for example: modprobe test_bitops.
2523 tristate "Test module for stress/performance analysis of vmalloc allocator"
2528 This builds the "test_vmalloc" module that should be used for
2529 stress and performance analysis. So, any new change for vmalloc
2530 subsystem can be evaluated from performance and stability point
2536 tristate "Test BPF filter functionality"
2539 This builds the "test_bpf" module that runs various test vectors
2540 against the BPF interpreter or BPF JIT compiler depending on the
2541 current setting. This is in particular useful for BPF JIT compiler
2542 development, but also to run regression tests against changes in
2543 the interpreter code. It also enables test stubs for eBPF maps and
2544 verifier used by user space verifier testsuite.
2548 config TEST_BLACKHOLE_DEV
2549 tristate "Test blackhole netdev functionality"
2552 This builds the "test_blackhole_dev" module that validates the
2553 data path through this blackhole netdev.
2557 config FIND_BIT_BENCHMARK
2558 tristate "Test find_bit functions"
2560 This builds the "test_find_bit" module that measure find_*_bit()
2561 functions performance.
2565 config TEST_FIRMWARE
2566 tristate "Test firmware loading via userspace interface"
2567 depends on FW_LOADER
2569 This builds the "test_firmware" module that creates a userspace
2570 interface for testing firmware loading. This can be used to
2571 control the triggering of firmware loading without needing an
2572 actual firmware-using device. The contents can be rechecked by
2578 tristate "sysctl test driver"
2579 depends on PROC_SYSCTL
2581 This builds the "test_sysctl" module. This driver enables to test the
2582 proc sysctl interfaces available to drivers safely without affecting
2583 production knobs which might alter system functionality.
2587 config BITFIELD_KUNIT
2588 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2590 default KUNIT_ALL_TESTS
2592 Enable this option to test the bitfield functions at boot.
2594 KUnit tests run during boot and output the results to the debug log
2595 in TAP format (http://testanything.org/). Only useful for kernel devs
2596 running the KUnit test harness, and not intended for inclusion into a
2599 For more information on KUnit and unit tests in general please refer
2600 to the KUnit documentation in Documentation/dev-tools/kunit/.
2604 config CHECKSUM_KUNIT
2605 tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2607 default KUNIT_ALL_TESTS
2609 Enable this option to test the checksum functions at boot.
2611 KUnit tests run during boot and output the results to the debug log
2612 in TAP format (http://testanything.org/). Only useful for kernel devs
2613 running the KUnit test harness, and not intended for inclusion into a
2616 For more information on KUnit and unit tests in general please refer
2617 to the KUnit documentation in Documentation/dev-tools/kunit/.
2621 config HASH_KUNIT_TEST
2622 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2624 default KUNIT_ALL_TESTS
2626 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2627 integer (<linux/hash.h>) hash functions on boot.
2629 KUnit tests run during boot and output the results to the debug log
2630 in TAP format (https://testanything.org/). Only useful for kernel devs
2631 running the KUnit test harness, and not intended for inclusion into a
2634 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Documentation/dev-tools/kunit/.
2637 This is intended to help people writing architecture-specific
2638 optimized versions. If unsure, say N.
2640 config RESOURCE_KUNIT_TEST
2641 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2643 default KUNIT_ALL_TESTS
2644 select GET_FREE_REGION
2646 This builds the resource API unit test.
2647 Tests the logic of API provided by resource.c and ioport.h.
2648 For more information on KUnit and unit tests in general please refer
2649 to the KUnit documentation in Documentation/dev-tools/kunit/.
2653 config SYSCTL_KUNIT_TEST
2654 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2656 default KUNIT_ALL_TESTS
2658 This builds the proc sysctl unit test, which runs on boot.
2659 Tests the API contract and implementation correctness of sysctl.
2660 For more information on KUnit and unit tests in general please refer
2661 to the KUnit documentation in Documentation/dev-tools/kunit/.
2665 config LIST_KUNIT_TEST
2666 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2668 default KUNIT_ALL_TESTS
2670 This builds the linked list KUnit test suite.
2671 It tests that the API and basic functionality of the list_head type
2672 and associated macros.
2674 KUnit tests run during boot and output the results to the debug log
2675 in TAP format (https://testanything.org/). Only useful for kernel devs
2676 running the KUnit test harness, and not intended for inclusion into a
2679 For more information on KUnit and unit tests in general please refer
2680 to the KUnit documentation in Documentation/dev-tools/kunit/.
2684 config HASHTABLE_KUNIT_TEST
2685 tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2687 default KUNIT_ALL_TESTS
2689 This builds the hashtable KUnit test suite.
2690 It tests the basic functionality of the API defined in
2691 include/linux/hashtable.h. For more information on KUnit and
2692 unit tests in general please refer to the KUnit documentation
2693 in Documentation/dev-tools/kunit/.
2697 config LINEAR_RANGES_TEST
2698 tristate "KUnit test for linear_ranges"
2700 select LINEAR_RANGES
2702 This builds the linear_ranges unit test, which runs on boot.
2703 Tests the linear_ranges logic correctness.
2704 For more information on KUnit and unit tests in general please refer
2705 to the KUnit documentation in Documentation/dev-tools/kunit/.
2709 config CMDLINE_KUNIT_TEST
2710 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2712 default KUNIT_ALL_TESTS
2714 This builds the cmdline API unit test.
2715 Tests the logic of API provided by cmdline.c.
2716 For more information on KUnit and unit tests in general please refer
2717 to the KUnit documentation in Documentation/dev-tools/kunit/.
2722 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2724 default KUNIT_ALL_TESTS
2726 This builds the bits unit test.
2727 Tests the logic of macros defined in bits.h.
2728 For more information on KUnit and unit tests in general please refer
2729 to the KUnit documentation in Documentation/dev-tools/kunit/.
2733 config SLUB_KUNIT_TEST
2734 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2735 depends on SLUB_DEBUG && KUNIT
2736 default KUNIT_ALL_TESTS
2738 This builds SLUB allocator unit test.
2739 Tests SLUB cache debugging functionality.
2740 For more information on KUnit and unit tests in general please refer
2741 to the KUnit documentation in Documentation/dev-tools/kunit/.
2745 config RATIONAL_KUNIT_TEST
2746 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2747 depends on KUNIT && RATIONAL
2748 default KUNIT_ALL_TESTS
2750 This builds the rational math unit test.
2751 For more information on KUnit and unit tests in general please refer
2752 to the KUnit documentation in Documentation/dev-tools/kunit/.
2756 config MEMCPY_KUNIT_TEST
2757 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2759 default KUNIT_ALL_TESTS
2761 Builds unit tests for memcpy(), memmove(), and memset() functions.
2762 For more information on KUnit and unit tests in general please refer
2763 to the KUnit documentation in Documentation/dev-tools/kunit/.
2767 config IS_SIGNED_TYPE_KUNIT_TEST
2768 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2770 default KUNIT_ALL_TESTS
2772 Builds unit tests for the is_signed_type() macro.
2774 For more information on KUnit and unit tests in general please refer
2775 to the KUnit documentation in Documentation/dev-tools/kunit/.
2779 config OVERFLOW_KUNIT_TEST
2780 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2782 default KUNIT_ALL_TESTS
2784 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2787 For more information on KUnit and unit tests in general please refer
2788 to the KUnit documentation in Documentation/dev-tools/kunit/.
2792 config STACKINIT_KUNIT_TEST
2793 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2795 default KUNIT_ALL_TESTS
2797 Test if the kernel is zero-initializing stack variables and
2798 padding. Coverage is controlled by compiler flags,
2799 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2800 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2801 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2803 config FORTIFY_KUNIT_TEST
2804 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2806 default KUNIT_ALL_TESTS
2808 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2809 by the str*() and mem*() family of functions. For testing runtime
2810 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2812 config HW_BREAKPOINT_KUNIT_TEST
2813 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2814 depends on HAVE_HW_BREAKPOINT
2816 default KUNIT_ALL_TESTS
2818 Tests for hw_breakpoint constraints accounting.
2822 config SIPHASH_KUNIT_TEST
2823 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2825 default KUNIT_ALL_TESTS
2827 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2828 functions on boot (or module load).
2830 This is intended to help people writing architecture-specific
2831 optimized versions. If unsure, say N.
2833 config USERCOPY_KUNIT_TEST
2834 tristate "KUnit Test for user/kernel boundary protections"
2836 default KUNIT_ALL_TESTS
2838 This builds the "usercopy_kunit" module that runs sanity checks
2839 on the copy_to/from_user infrastructure, making sure basic
2840 user/kernel boundary testing is working.
2843 tristate "udelay test driver"
2845 This builds the "udelay_test" module that helps to make sure
2846 that udelay() is working properly.
2850 config TEST_STATIC_KEYS
2851 tristate "Test static keys"
2854 Test the static key interfaces.
2858 config TEST_DYNAMIC_DEBUG
2859 tristate "Test DYNAMIC_DEBUG"
2860 depends on DYNAMIC_DEBUG
2862 This module registers a tracer callback to count enabled
2863 pr_debugs in a 'do_debugging' function, then alters their
2864 enablements, calls the function, and compares counts.
2869 tristate "kmod stress tester"
2871 depends on NETDEVICES && NET_CORE && INET # for TUN
2873 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2879 Test the kernel's module loading mechanism: kmod. kmod implements
2880 support to load modules using the Linux kernel's usermode helper.
2881 This test provides a series of tests against kmod.
2883 Although technically you can either build test_kmod as a module or
2884 into the kernel we disallow building it into the kernel since
2885 it stress tests request_module() and this will very likely cause
2886 some issues by taking over precious threads available from other
2887 module load requests, ultimately this could be fatal.
2891 tools/testing/selftests/kmod/kmod.sh --help
2895 config TEST_DEBUG_VIRTUAL
2896 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2897 depends on DEBUG_VIRTUAL
2899 Test the kernel's ability to detect incorrect calls to
2900 virt_to_phys() done against the non-linear part of the
2901 kernel's virtual address map.
2905 config TEST_MEMCAT_P
2906 tristate "Test memcat_p() helper function"
2908 Test the memcat_p() helper for correctly merging two
2909 pointer arrays together.
2914 tristate "Perform selftest on object aggreration manager"
2918 Enable this option to test object aggregation manager on boot
2922 tristate "Test heap/page initialization"
2924 Test if the kernel is zero-initializing heap and page allocations.
2925 This can be useful to test init_on_alloc and init_on_free features.
2930 tristate "Test HMM (Heterogeneous Memory Management)"
2931 depends on TRANSPARENT_HUGEPAGE
2932 depends on DEVICE_PRIVATE
2936 This is a pseudo device driver solely for testing HMM.
2937 Say M here if you want to build the HMM test module.
2938 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2942 config TEST_FREE_PAGES
2943 tristate "Test freeing pages"
2945 Test that a memory leak does not occur due to a race between
2946 freeing a block of pages and a speculative page reference.
2947 Loading this module is safe if your kernel has the bug fixed.
2948 If the bug is not fixed, it will leak gigabytes of memory and
2949 probably OOM your system.
2952 tristate "Test floating point operations in kernel space"
2953 depends on ARCH_HAS_KERNEL_FPU_SUPPORT && !KCOV_INSTRUMENT_ALL
2955 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2956 which will trigger a sequence of floating point operations. This is used
2957 for self-testing floating point control register setting in
2962 config TEST_CLOCKSOURCE_WATCHDOG
2963 tristate "Test clocksource watchdog in kernel space"
2964 depends on CLOCKSOURCE_WATCHDOG
2966 Enable this option to create a kernel module that will trigger
2967 a test of the clocksource watchdog. This module may be loaded
2968 via modprobe or insmod in which case it will run upon being
2969 loaded, or it may be built in, in which case it will run
2975 tristate "Test module for correctness and stress of objpool"
2977 depends on m && DEBUG_KERNEL
2979 This builds the "test_objpool" module that should be used for
2980 correctness verification and concurrent testings of objects
2981 allocation and reclamation.
2985 endif # RUNTIME_TESTING_MENU
2987 config ARCH_USE_MEMTEST
2990 An architecture should select this when it uses early_memtest()
2991 during boot process.
2995 depends on ARCH_USE_MEMTEST
2997 This option adds a kernel parameter 'memtest', which allows memtest
2998 to be set and executed.
2999 memtest=0, mean disabled; -- default
3000 memtest=1, mean do 1 test pattern;
3002 memtest=17, mean do 17 test patterns.
3003 If you are unsure how to answer this question, answer N.
3007 config HYPERV_TESTING
3008 bool "Microsoft Hyper-V driver testing"
3010 depends on HYPERV && DEBUG_FS
3012 Select this option to enable Hyper-V vmbus testing.
3014 endmenu # "Kernel Testing and Coverage"
3018 config RUST_DEBUG_ASSERTIONS
3019 bool "Debug assertions"
3022 Enables rustc's `-Cdebug-assertions` codegen option.
3024 This flag lets you turn `cfg(debug_assertions)` conditional
3025 compilation on or off. This can be used to enable extra debugging
3026 code in development but not in production. For example, it controls
3027 the behavior of the standard library's `debug_assert!` macro.
3029 Note that this will apply to all Rust code, including `core`.
3033 config RUST_OVERFLOW_CHECKS
3034 bool "Overflow checks"
3038 Enables rustc's `-Coverflow-checks` codegen option.
3040 This flag allows you to control the behavior of runtime integer
3041 overflow. When overflow-checks are enabled, a Rust panic will occur
3044 Note that this will apply to all Rust code, including `core`.
3048 config RUST_BUILD_ASSERT_ALLOW
3049 bool "Allow unoptimized build-time assertions"
3052 Controls how `build_error!` and `build_assert!` are handled during the build.
3054 If calls to them exist in the binary, it may indicate a violated invariant
3055 or that the optimizer failed to verify the invariant during compilation.
3057 This should not happen, thus by default the build is aborted. However,
3058 as an escape hatch, you can choose Y here to ignore them during build
3059 and let the check be carried at runtime (with `panic!` being called if
3064 config RUST_KERNEL_DOCTESTS
3065 bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3066 depends on RUST && KUNIT=y
3067 default KUNIT_ALL_TESTS
3069 This builds the documentation tests of the `kernel` crate
3072 For more information on KUnit and unit tests in general,
3073 please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3079 endmenu # Kernel hacking
3082 tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS
3084 default KUNIT_ALL_TESTS
3086 This option enables the KUnit test suite for the int_pow function,
3087 which performs integer exponentiation. The test suite is designed to
3088 verify that the implementation of int_pow correctly computes the power
3089 of a given base raised to a given exponent.
3091 Enabling this option will include tests that check various scenarios
3092 and edge cases to ensure the accuracy and reliability of the exponentiation
projects / J-linux.git / blob