xref: /linux/lib/Kconfig.debug (revision 23794bec1cb606fee9e4876f0e86f592e1301f58)
1# SPDX-License-Identifier: GPL-2.0-only
2menu "Kernel hacking"
3
4menu "printk and dmesg options"
5
6config PRINTK_TIME
7	bool "Show timing information on printks"
8	depends on PRINTK
9	help
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.
13
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.
17
18	  The behavior is also controlled by the kernel command line
19	  parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
20
21config PRINTK_CALLER
22	bool "Show caller information on printks"
23	depends on PRINTK
24	help
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)
27	  to every message.
28
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.
33
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
36	  sysfs interface.
37
38config PRINTK_EXECUTION_CTX
39	bool
40	depends on PRINTK
41	help
42	  This option extends struct printk_info to include extra execution
43	  context in printk, such as task name and CPU number from where the
44	  message originated. This is useful for correlating printk messages
45	  with specific execution contexts.
46
47	  This is automatically enabled when a console driver that supports
48	  execution context is selected.
49
50config STACKTRACE_BUILD_ID
51	bool "Show build ID information in stacktraces"
52	depends on PRINTK
53	help
54	  Selecting this option adds build ID information for symbols in
55	  stacktraces printed with the printk format '%p[SR]b'.
56
57	  This option is intended for distros where debuginfo is not easily
58	  accessible but can be downloaded given the build ID of the vmlinux or
59	  kernel module where the function is located.
60
61config CONSOLE_LOGLEVEL_DEFAULT
62	int "Default console loglevel (1-15)"
63	range 1 15
64	default "7"
65	help
66	  Default loglevel to determine what will be printed on the console.
67
68	  Setting a default here is equivalent to passing in loglevel=<x> in
69	  the kernel bootargs. loglevel=<x> continues to override whatever
70	  value is specified here as well.
71
72	  Note: This does not affect the log level of un-prefixed printk()
73	  usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
74	  option.
75
76config CONSOLE_LOGLEVEL_QUIET
77	int "quiet console loglevel (1-15)"
78	range 1 15
79	default "4"
80	help
81	  loglevel to use when "quiet" is passed on the kernel commandline.
82
83	  When "quiet" is passed on the kernel commandline this loglevel
84	  will be used as the loglevel. IOW passing "quiet" will be the
85	  equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
86
87config MESSAGE_LOGLEVEL_DEFAULT
88	int "Default message log level (1-7)"
89	range 1 7
90	default "4"
91	help
92	  Default log level for printk statements with no specified priority.
93
94	  This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
95	  that are auditing their logs closely may want to set it to a lower
96	  priority.
97
98	  Note: This does not affect what message level gets printed on the console
99	  by default. To change that, use loglevel=<x> in the kernel bootargs,
100	  or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
101
102config BOOT_PRINTK_DELAY
103	bool "Delay each boot printk message by N milliseconds"
104	depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
105	help
106	  This build option allows you to read kernel boot messages
107	  by inserting a short delay after each one.  The delay is
108	  specified in milliseconds on the kernel command line,
109	  using "boot_delay=N".
110
111	  It is likely that you would also need to use "lpj=M" to preset
112	  the "loops per jiffy" value.
113	  See a previous boot log for the "lpj" value to use for your
114	  system, and then set "lpj=M" before setting "boot_delay=N".
115	  NOTE:  Using this option may adversely affect SMP systems.
116	  I.e., processors other than the first one may not boot up.
117	  BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
118	  what it believes to be lockup conditions.
119
120config DYNAMIC_DEBUG
121	bool "Enable dynamic printk() support"
122	default n
123	depends on PRINTK
124	depends on (DEBUG_FS || PROC_FS)
125	select DYNAMIC_DEBUG_CORE
126	help
127
128	  Compiles debug level messages into the kernel, which would not
129	  otherwise be available at runtime. These messages can then be
130	  enabled/disabled based on various levels of scope - per source file,
131	  function, module, format string, and line number. This mechanism
132	  implicitly compiles in all pr_debug() and dev_dbg() calls, which
133	  enlarges the kernel text size by about 2%.
134
135	  If a source file is compiled with DEBUG flag set, any
136	  pr_debug() calls in it are enabled by default, but can be
137	  disabled at runtime as below.  Note that DEBUG flag is
138	  turned on by many CONFIG_*DEBUG* options.
139
140	  Usage:
141
142	  Dynamic debugging is controlled via the 'dynamic_debug/control' file,
143	  which is contained in the 'debugfs' filesystem or procfs.
144	  Thus, the debugfs or procfs filesystem must first be mounted before
145	  making use of this feature.
146	  We refer the control file as: <debugfs>/dynamic_debug/control. This
147	  file contains a list of the debug statements that can be enabled. The
148	  format for each line of the file is:
149
150		filename:lineno [module]function flags format
151
152	  filename : source file of the debug statement
153	  lineno : line number of the debug statement
154	  module : module that contains the debug statement
155	  function : function that contains the debug statement
156	  flags : '=p' means the line is turned 'on' for printing
157	  format : the format used for the debug statement
158
159	  From a live system:
160
161		nullarbor:~ # cat <debugfs>/dynamic_debug/control
162		# filename:lineno [module]function flags format
163		fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
164		fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
165		fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
166
167	  Example usage:
168
169		// enable the message at line 1603 of file svcsock.c
170		nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
171						<debugfs>/dynamic_debug/control
172
173		// enable all the messages in file svcsock.c
174		nullarbor:~ # echo -n 'file svcsock.c +p' >
175						<debugfs>/dynamic_debug/control
176
177		// enable all the messages in the NFS server module
178		nullarbor:~ # echo -n 'module nfsd +p' >
179						<debugfs>/dynamic_debug/control
180
181		// enable all 12 messages in the function svc_process()
182		nullarbor:~ # echo -n 'func svc_process +p' >
183						<debugfs>/dynamic_debug/control
184
185		// disable all 12 messages in the function svc_process()
186		nullarbor:~ # echo -n 'func svc_process -p' >
187						<debugfs>/dynamic_debug/control
188
189	  See Documentation/admin-guide/dynamic-debug-howto.rst for additional
190	  information.
191
192config DYNAMIC_DEBUG_CORE
193	bool "Enable core function of dynamic debug support"
194	depends on PRINTK
195	depends on (DEBUG_FS || PROC_FS)
196	help
197	  Enable core functional support of dynamic debug. It is useful
198	  when you want to tie dynamic debug to your kernel modules with
199	  DYNAMIC_DEBUG_MODULE defined for each of them, especially for
200	  the case of embedded system where the kernel image size is
201	  sensitive for people.
202
203config SYMBOLIC_ERRNAME
204	bool "Support symbolic error names in printf"
205	default y if PRINTK
206	help
207	  If you say Y here, the kernel's printf implementation will
208	  be able to print symbolic error names such as ENOSPC instead
209	  of the number 28. It makes the kernel image slightly larger
210	  (about 3KB), but can make the kernel logs easier to read.
211
212config DEBUG_BUGVERBOSE
213	bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
214	depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
215	default y
216	help
217	  Say Y here to make BUG() panics output the file name and line number
218	  of the BUG call as well as the EIP and oops trace.  This aids
219	  debugging but costs about 70-100K of memory.
220
221config DEBUG_BUGVERBOSE_DETAILED
222	bool "Verbose WARN_ON_ONCE() reporting (adds 100K)" if DEBUG_BUGVERBOSE
223	help
224	  Say Y here to make WARN_ON_ONCE() output the condition string of the
225	  warning, in addition to the file name and line number.
226	  This helps debugging, but costs about 100K of memory.
227
228	  Say N if unsure.
229
230
231endmenu # "printk and dmesg options"
232
233config DEBUG_KERNEL
234	bool "Kernel debugging"
235	help
236	  Say Y here if you are developing drivers or trying to debug and
237	  identify kernel problems.
238
239config DEBUG_MISC
240	bool "Miscellaneous debug code"
241	default DEBUG_KERNEL
242	depends on DEBUG_KERNEL
243	help
244	  Say Y here if you need to enable miscellaneous debug code that should
245	  be under a more specific debug option but isn't.
246
247menu "Compile-time checks and compiler options"
248
249config DEBUG_INFO
250	bool
251	help
252	  A kernel debug info option other than "None" has been selected
253	  in the "Debug information" choice below, indicating that debug
254	  information will be generated for build targets.
255
256# Clang generates .uleb128 with label differences for DWARF v5, a feature that
257# older binutils ports do not support when utilizing RISC-V style linker
258# relaxation: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
259config AS_HAS_NON_CONST_ULEB128
260	def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
261
262choice
263	prompt "Debug information"
264	depends on DEBUG_KERNEL
265	help
266	  Selecting something other than "None" results in a kernel image
267	  that will include debugging info resulting in a larger kernel image.
268	  This adds debug symbols to the kernel and modules (gcc -g), and
269	  is needed if you intend to use kernel crashdump or binary object
270	  tools like crash, kgdb, LKCD, gdb, etc on the kernel.
271
272	  Choose which version of DWARF debug info to emit. If unsure,
273	  select "Toolchain default".
274
275config DEBUG_INFO_NONE
276	bool "Disable debug information"
277	help
278	  Do not build the kernel with debugging information, which will
279	  result in a faster and smaller build.
280
281config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
282	bool "Rely on the toolchain's implicit default DWARF version"
283	select DEBUG_INFO
284	depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
285	help
286	  The implicit default version of DWARF debug info produced by a
287	  toolchain changes over time.
288
289	  This can break consumers of the debug info that haven't upgraded to
290	  support newer revisions, and prevent testing newer versions, but
291	  those should be less common scenarios.
292
293config DEBUG_INFO_DWARF4
294	bool "Generate DWARF Version 4 debuginfo"
295	select DEBUG_INFO
296	depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
297	help
298	  Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
299	  if using clang without clang's integrated assembler, and gdb 7.0+.
300
301	  If you have consumers of DWARF debug info that are not ready for
302	  newer revisions of DWARF, you may wish to choose this or have your
303	  config select this.
304
305config DEBUG_INFO_DWARF5
306	bool "Generate DWARF Version 5 debuginfo"
307	select DEBUG_INFO
308	depends on !ARCH_HAS_BROKEN_DWARF5
309	depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
310	help
311	  Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
312	  5.0+ accepts the -gdwarf-5 flag but only had partial support for some
313	  draft features until 7.0), and gdb 8.0+.
314
315	  Changes to the structure of debug info in Version 5 allow for around
316	  15-18% savings in resulting image and debug info section sizes as
317	  compared to DWARF Version 4. DWARF Version 5 standardizes previous
318	  extensions such as accelerators for symbol indexing and the format
319	  for fission (.dwo/.dwp) files. Users may not want to select this
320	  config if they rely on tooling that has not yet been updated to
321	  support DWARF Version 5.
322
323endchoice # "Debug information"
324
325if DEBUG_INFO
326
327config DEBUG_INFO_REDUCED
328	bool "Reduce debugging information"
329	help
330	  If you say Y here gcc is instructed to generate less debugging
331	  information for structure types. This means that tools that
332	  need full debugging information (like kgdb or systemtap) won't
333	  be happy. But if you merely need debugging information to
334	  resolve line numbers there is no loss. Advantage is that
335	  build directory object sizes shrink dramatically over a full
336	  DEBUG_INFO build and compile times are reduced too.
337	  Only works with newer gcc versions.
338
339choice
340	prompt "Compressed Debug information"
341	help
342	  Compress the resulting debug info. Results in smaller debug info sections,
343	  but requires that consumers are able to decompress the results.
344
345	  If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
346
347config DEBUG_INFO_COMPRESSED_NONE
348	bool "Don't compress debug information"
349	help
350	  Don't compress debug info sections.
351
352config DEBUG_INFO_COMPRESSED_ZLIB
353	bool "Compress debugging information with zlib"
354	depends on $(cc-option,-gz=zlib)
355	depends on $(ld-option,--compress-debug-sections=zlib)
356	help
357	  Compress the debug information using zlib.
358
359	  Users of dpkg-deb via debian/rules may find an increase in
360	  size of their debug .deb packages with this config set, due to the
361	  debug info being compressed with zlib, then the object files being
362	  recompressed with a different compression scheme. But this is still
363	  preferable to setting KDEB_COMPRESS or DPKG_DEB_COMPRESSOR_TYPE to
364	  "none" which would be even larger.
365
366config DEBUG_INFO_COMPRESSED_ZSTD
367	bool "Compress debugging information with zstd"
368	depends on $(cc-option,-gz=zstd)
369	depends on $(ld-option,--compress-debug-sections=zstd)
370	help
371	  Compress the debug information using zstd.  This may provide better
372	  compression than zlib, for about the same time costs, but requires newer
373	  toolchain support.  Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
374	  zstd.
375
376endchoice # "Compressed Debug information"
377
378config DEBUG_INFO_SPLIT
379	bool "Produce split debuginfo in .dwo files"
380	depends on $(cc-option,-gsplit-dwarf)
381	# RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
382	# prior to 12.x:
383	# https://github.com/llvm/llvm-project/issues/56642
384	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
385	depends on !RISCV || GCC_VERSION >= 120000
386	help
387	  Generate debug info into separate .dwo files. This significantly
388	  reduces the build directory size for builds with DEBUG_INFO,
389	  because it stores the information only once on disk in .dwo
390	  files instead of multiple times in object files and executables.
391	  In addition the debug information is also compressed.
392
393	  Requires recent gcc (4.7+) and recent gdb/binutils.
394	  Any tool that packages or reads debug information would need
395	  to know about the .dwo files and include them.
396	  Incompatible with older versions of ccache.
397
398config DEBUG_INFO_BTF
399	bool "Generate BTF type information"
400	depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
401	depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
402	depends on BPF_SYSCALL
403	depends on PAHOLE_VERSION >= 116
404	depends on DEBUG_INFO_DWARF4 || PAHOLE_VERSION >= 121
405	# pahole uses elfutils, which does not have support for Hexagon relocations
406	depends on !HEXAGON
407	help
408	  Generate deduplicated BTF type information from DWARF debug info.
409	  Turning this on requires pahole v1.16 or later (v1.21 or later to
410	  support DWARF 5), which will convert DWARF type info into equivalent
411	  deduplicated BTF type info.
412
413config PAHOLE_HAS_SPLIT_BTF
414	def_bool PAHOLE_VERSION >= 119
415
416config PAHOLE_HAS_BTF_TAG
417	def_bool PAHOLE_VERSION >= 123
418	depends on CC_IS_CLANG
419	help
420	  Decide whether pahole emits btf_tag attributes (btf_type_tag and
421	  btf_decl_tag) or not. Currently only clang compiler implements
422	  these attributes, so make the config depend on CC_IS_CLANG.
423
424config PAHOLE_HAS_LANG_EXCLUDE
425	def_bool PAHOLE_VERSION >= 124
426	help
427	  Support for the --lang_exclude flag which makes pahole exclude
428	  compilation units from the supplied language. Used in Kbuild to
429	  omit Rust CUs which are not supported in version 1.24 of pahole,
430	  otherwise it would emit malformed kernel and module binaries when
431	  using DEBUG_INFO_BTF_MODULES.
432
433config DEBUG_INFO_BTF_MODULES
434	bool "Generate BTF type information for kernel modules"
435	default y
436	depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
437	help
438	  Generate compact split BTF type information for kernel modules.
439
440config MODULE_ALLOW_BTF_MISMATCH
441	bool "Allow loading modules with non-matching BTF type info"
442	depends on DEBUG_INFO_BTF_MODULES
443	help
444	  For modules whose split BTF does not match vmlinux, load without
445	  BTF rather than refusing to load. The default behavior with
446	  module BTF enabled is to reject modules with such mismatches;
447	  this option will still load module BTF where possible but ignore
448	  it when a mismatch is found.
449
450config GDB_SCRIPTS
451	bool "Provide GDB scripts for kernel debugging"
452	help
453	  This creates the required links to GDB helper scripts in the
454	  build directory. If you load vmlinux into gdb, the helper
455	  scripts will be automatically imported by gdb as well, and
456	  additional functions are available to analyze a Linux kernel
457	  instance. See Documentation/process/debugging/gdb-kernel-debugging.rst
458	  for further details.
459
460endif # DEBUG_INFO
461
462config FRAME_WARN
463	int "Warn for stack frames larger than"
464	range 0 8192
465	default 0 if KMSAN
466	default 2048 if GCC_PLUGIN_LATENT_ENTROPY
467	default 2048 if PARISC
468	default 1536 if (!64BIT && XTENSA)
469	default 1280 if !64BIT
470	default 2048 if 64BIT
471	help
472	  Tell the compiler to warn at build time for stack frames larger than this.
473	  Setting this too low will cause a lot of warnings.
474	  Setting it to 0 disables the warning.
475
476config STRIP_ASM_SYMS
477	bool "Strip assembler-generated symbols during link"
478	default n
479	help
480	  Strip internal assembler-generated symbols during a link (symbols
481	  that look like '.Lxxx') so they don't pollute the output of
482	  get_wchan() and suchlike.
483
484config READABLE_ASM
485	bool "Generate readable assembler code"
486	depends on DEBUG_KERNEL
487	depends on CC_IS_GCC
488	help
489	  Disable some compiler optimizations that tend to generate human unreadable
490	  assembler output. This may make the kernel slightly slower, but it helps
491	  to keep kernel developers who have to stare a lot at assembler listings
492	  sane.
493
494config HEADERS_INSTALL
495	bool "Install uapi headers to usr/include"
496	help
497	  This option will install uapi headers (headers exported to user-space)
498	  into the usr/include directory for use during the kernel build.
499	  This is unneeded for building the kernel itself, but needed for some
500	  user-space program samples. It is also needed by some features such
501	  as uapi header sanity checks.
502
503config DEBUG_SECTION_MISMATCH
504	bool "Enable full Section mismatch analysis"
505	depends on CC_IS_GCC
506	help
507	  The section mismatch analysis checks if there are illegal references
508	  from one section to another. During linktime or runtime, some
509	  sections are dropped; any use of code/data previously in these
510	  sections would most likely result in an oops.
511
512	  In the code, functions and variables are annotated with __init,
513	  __initdata, and so on (see the full list in include/linux/init.h).
514	  This directs the toolchain to place code/data in specific sections.
515
516	  The section mismatch analysis is always performed after a full
517	  kernel build, and enabling this option causes the option
518	  -fno-inline-functions-called-once to be added to gcc commands.
519
520	  However, when inlining a function annotated with __init in
521	  a non-init function, we would lose the section information and thus
522	  the analysis would not catch the illegal reference.  This option
523	  tells gcc to inline less (but it does result in a larger kernel).
524
525config SECTION_MISMATCH_WARN_ONLY
526	bool "Make section mismatch errors non-fatal"
527	default y
528	help
529	  If you say N here, the build process will fail if there are any
530	  section mismatch, instead of just throwing warnings.
531
532	  If unsure, say Y.
533
534config DEBUG_FORCE_FUNCTION_ALIGN_64B
535	bool "Force all function address 64B aligned"
536	depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
537	select FUNCTION_ALIGNMENT_64B
538	help
539	  There are cases that a commit from one domain changes the function
540	  address alignment of other domains, and cause magic performance
541	  bump (regression or improvement). Enable this option will help to
542	  verify if the bump is caused by function alignment changes, while
543	  it will slightly increase the kernel size and affect icache usage.
544
545	  It is mainly for debug and performance tuning use.
546
547#
548# Select this config option from the architecture Kconfig, if it
549# is preferred to always offer frame pointers as a config
550# option on the architecture (regardless of KERNEL_DEBUG):
551#
552config ARCH_WANT_FRAME_POINTERS
553	bool
554
555config FRAME_POINTER
556	bool "Compile the kernel with frame pointers"
557	depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
558	default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
559	help
560	  If you say Y here the resulting kernel image will be slightly
561	  larger and slower, but it gives very useful debugging information
562	  in case of kernel bugs. (precise oopses/stacktraces/warnings)
563
564config OBJTOOL
565	bool
566
567config OBJTOOL_WERROR
568	bool "Upgrade objtool warnings to errors"
569	depends on OBJTOOL && !COMPILE_TEST
570	help
571	  Fail the build on objtool warnings.
572
573	  Objtool warnings can indicate kernel instability, including boot
574	  failures.  This option is highly recommended.
575
576	  If unsure, say Y.
577
578config STACK_VALIDATION
579	bool "Compile-time stack metadata validation"
580	depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
581	select OBJTOOL
582	default n
583	help
584	  Validate frame pointer rules at compile-time.  This helps ensure that
585	  runtime stack traces are more reliable.
586
587	  For more information, see
588	  tools/objtool/Documentation/objtool.txt.
589
590config NOINSTR_VALIDATION
591	bool
592	depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
593	select OBJTOOL
594	default y
595
596config VMLINUX_MAP
597	bool "Generate vmlinux.map file when linking"
598	depends on EXPERT
599	help
600	  Selecting this option will pass "-Map=vmlinux.map" to ld
601	  when linking vmlinux. That file can be useful for verifying
602	  and debugging magic section games, and for seeing which
603	  pieces of code get eliminated with
604	  CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
605
606config BUILTIN_MODULE_RANGES
607	bool "Generate address range information for builtin modules"
608	depends on !LTO
609	depends on VMLINUX_MAP
610	help
611	 When modules are built into the kernel, there will be no module name
612	 associated with its symbols in /proc/kallsyms.  Tracers may want to
613	 identify symbols by module name and symbol name regardless of whether
614	 the module is configured as loadable or not.
615
616	 This option generates modules.builtin.ranges in the build tree with
617	 offset ranges (per ELF section) for the module(s) they belong to.
618	 It also records an anchor symbol to determine the load address of the
619	 section.
620
621config DEBUG_FORCE_WEAK_PER_CPU
622	bool "Force weak per-cpu definitions"
623	depends on DEBUG_KERNEL
624	help
625	  s390 and alpha require percpu variables in modules to be
626	  defined weak to work around addressing range issue which
627	  puts the following two restrictions on percpu variable
628	  definitions.
629
630	  1. percpu symbols must be unique whether static or not
631	  2. percpu variables can't be defined inside a function
632
633	  To ensure that generic code follows the above rules, this
634	  option forces all percpu variables to be defined as weak.
635
636endmenu # "Compiler options"
637
638menu "Generic Kernel Debugging Instruments"
639
640config MAGIC_SYSRQ
641	bool "Magic SysRq key"
642	depends on !UML
643	help
644	  If you say Y here, you will have some control over the system even
645	  if the system crashes for example during kernel debugging (e.g., you
646	  will be able to flush the buffer cache to disk, reboot the system
647	  immediately or dump some status information). This is accomplished
648	  by pressing various keys while holding SysRq (Alt+PrintScreen). It
649	  also works on a serial console (on PC hardware at least), if you
650	  send a BREAK and then within 5 seconds a command keypress. The
651	  keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
652	  Don't say Y unless you really know what this hack does.
653
654config MAGIC_SYSRQ_DEFAULT_ENABLE
655	hex "Enable magic SysRq key functions by default"
656	depends on MAGIC_SYSRQ
657	default 0x1
658	help
659	  Specifies which SysRq key functions are enabled by default.
660	  This may be set to 1 or 0 to enable or disable them all, or
661	  to a bitmask as described in Documentation/admin-guide/sysrq.rst.
662
663config MAGIC_SYSRQ_SERIAL
664	bool "Enable magic SysRq key over serial"
665	depends on MAGIC_SYSRQ
666	default y
667	help
668	  Many embedded boards have a disconnected TTL level serial which can
669	  generate some garbage that can lead to spurious false sysrq detects.
670	  This option allows you to decide whether you want to enable the
671	  magic SysRq key.
672
673config MAGIC_SYSRQ_SERIAL_SEQUENCE
674	string "Char sequence that enables magic SysRq over serial"
675	depends on MAGIC_SYSRQ_SERIAL
676	default ""
677	help
678	  Specifies a sequence of characters that can follow BREAK to enable
679	  SysRq on a serial console.
680
681	  If unsure, leave an empty string and the option will not be enabled.
682
683config DEBUG_FS
684	bool "Debug Filesystem"
685	help
686	  debugfs is a virtual file system that kernel developers use to put
687	  debugging files into.  Enable this option to be able to read and
688	  write to these files.
689
690	  For detailed documentation on the debugfs API, see
691	  Documentation/filesystems/.
692
693	  If unsure, say N.
694
695choice
696	prompt "Debugfs default access"
697	depends on DEBUG_FS
698	default DEBUG_FS_ALLOW_ALL
699	help
700	  This selects the default access restrictions for debugfs.
701	  It can be overridden with kernel command line option
702	  debugfs=[on,off]. The restrictions apply for API access
703	  and filesystem registration.
704
705config DEBUG_FS_ALLOW_ALL
706	bool "Access normal"
707	help
708	  No restrictions apply. Both API and filesystem registration
709	  is on. This is the normal default operation.
710
711config DEBUG_FS_ALLOW_NONE
712	bool "No access"
713	help
714	  Access is off. Clients get -PERM when trying to create nodes in
715	  debugfs tree and debugfs is not registered as a filesystem.
716	  Client can then back-off or continue without debugfs access.
717
718endchoice
719
720source "lib/Kconfig.kgdb"
721source "lib/Kconfig.ubsan"
722source "lib/Kconfig.kcsan"
723
724endmenu
725
726menu "Networking Debugging"
727
728source "net/Kconfig.debug"
729
730endmenu # "Networking Debugging"
731
732menu "Memory Debugging"
733
734source "mm/Kconfig.debug"
735
736config DEBUG_OBJECTS
737	bool "Debug object operations"
738	depends on DEBUG_KERNEL
739	help
740	  If you say Y here, additional code will be inserted into the
741	  kernel to track the life time of various objects and validate
742	  the operations on those objects.
743
744config DEBUG_OBJECTS_SELFTEST
745	bool "Debug objects selftest"
746	depends on DEBUG_OBJECTS
747	help
748	  This enables the selftest of the object debug code.
749
750config DEBUG_OBJECTS_FREE
751	bool "Debug objects in freed memory"
752	depends on DEBUG_OBJECTS
753	help
754	  This enables checks whether a k/v free operation frees an area
755	  which contains an object which has not been deactivated
756	  properly. This can make kmalloc/kfree-intensive workloads
757	  much slower.
758
759config DEBUG_OBJECTS_TIMERS
760	bool "Debug timer objects"
761	depends on DEBUG_OBJECTS
762	help
763	  If you say Y here, additional code will be inserted into the
764	  timer routines to track the life time of timer objects and
765	  validate the timer operations.
766
767config DEBUG_OBJECTS_WORK
768	bool "Debug work objects"
769	depends on DEBUG_OBJECTS
770	help
771	  If you say Y here, additional code will be inserted into the
772	  work queue routines to track the life time of work objects and
773	  validate the work operations.
774
775config DEBUG_OBJECTS_RCU_HEAD
776	bool "Debug RCU callbacks objects"
777	depends on DEBUG_OBJECTS
778	help
779	  Enable this to turn on debugging of RCU list heads (call_rcu() usage).
780
781config DEBUG_OBJECTS_PERCPU_COUNTER
782	bool "Debug percpu counter objects"
783	depends on DEBUG_OBJECTS
784	help
785	  If you say Y here, additional code will be inserted into the
786	  percpu counter routines to track the life time of percpu counter
787	  objects and validate the percpu counter operations.
788
789config DEBUG_OBJECTS_ENABLE_DEFAULT
790	int "debug_objects bootup default value (0-1)"
791	range 0 1
792	default "1"
793	depends on DEBUG_OBJECTS
794	help
795	  Debug objects boot parameter default value
796
797config SHRINKER_DEBUG
798	bool "Enable shrinker debugging support"
799	depends on DEBUG_FS
800	help
801	  Say Y to enable the shrinker debugfs interface which provides
802	  visibility into the kernel memory shrinkers subsystem.
803	  Disable it to avoid an extra memory footprint.
804
805config DEBUG_STACK_USAGE
806	bool "Stack utilization instrumentation"
807	depends on DEBUG_KERNEL
808	help
809	  Enables the display of the minimum amount of free stack which each
810	  task has ever had available in the sysrq-T and sysrq-P debug output.
811	  Also emits a message to dmesg when a process exits if that process
812	  used more stack space than previously exiting processes.
813
814	  This option will slow down process creation somewhat.
815
816config SCHED_STACK_END_CHECK
817	bool "Detect stack corruption on calls to schedule()"
818	depends on DEBUG_KERNEL
819	default n
820	help
821	  This option checks for a stack overrun on calls to schedule().
822	  If the stack end location is found to be over written always panic as
823	  the content of the corrupted region can no longer be trusted.
824	  This is to ensure no erroneous behaviour occurs which could result in
825	  data corruption or a sporadic crash at a later stage once the region
826	  is examined. The runtime overhead introduced is minimal.
827
828config ARCH_HAS_DEBUG_VM_PGTABLE
829	bool
830	help
831	  An architecture should select this when it can successfully
832	  build and run DEBUG_VM_PGTABLE.
833
834config DEBUG_VFS
835	bool "Debug VFS"
836	depends on DEBUG_KERNEL
837	help
838	  Enable this to turn on extended checks in the VFS layer that may impact
839	  performance.
840
841	  If unsure, say N.
842
843config DEBUG_VM_IRQSOFF
844	def_bool DEBUG_VM && !PREEMPT_RT
845
846config DEBUG_VM
847	bool "Debug VM"
848	depends on DEBUG_KERNEL
849	help
850	  Enable this to turn on extended checks in the virtual-memory system
851	  that may impact performance.
852
853	  If unsure, say N.
854
855config DEBUG_VM_SHOOT_LAZIES
856	bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
857	depends on DEBUG_VM
858	depends on MMU_LAZY_TLB_SHOOTDOWN
859	help
860	  Enable additional IPIs that ensure lazy tlb mm references are removed
861	  before the mm is freed.
862
863	  If unsure, say N.
864
865config DEBUG_VM_MAPLE_TREE
866	bool "Debug VM maple trees"
867	depends on DEBUG_VM
868	select DEBUG_MAPLE_TREE
869	help
870	  Enable VM maple tree debugging information and extra validations.
871
872	  If unsure, say N.
873
874config DEBUG_VM_RB
875	bool "Debug VM red-black trees"
876	depends on DEBUG_VM
877	help
878	  Enable VM red-black tree debugging information and extra validations.
879
880	  If unsure, say N.
881
882config DEBUG_VM_PGFLAGS
883	bool "Debug page-flags operations"
884	depends on DEBUG_VM
885	help
886	  Enables extra validation on page flags operations.
887
888	  If unsure, say N.
889
890config DEBUG_VM_PGTABLE
891	bool "Debug arch page table for semantics compliance"
892	depends on MMU
893	depends on ARCH_HAS_DEBUG_VM_PGTABLE
894	default y if DEBUG_VM
895	help
896	  This option provides a debug method which can be used to test
897	  architecture page table helper functions on various platforms in
898	  verifying if they comply with expected generic MM semantics. This
899	  will help architecture code in making sure that any changes or
900	  new additions of these helpers still conform to expected
901	  semantics of the generic MM. Platforms will have to opt in for
902	  this through ARCH_HAS_DEBUG_VM_PGTABLE.
903
904	  If unsure, say N.
905
906config ARCH_HAS_DEBUG_VIRTUAL
907	bool
908
909config DEBUG_VIRTUAL
910	bool "Debug VM translations"
911	depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
912	help
913	  Enable some costly sanity checks in virtual to page code. This can
914	  catch mistakes with virt_to_page() and friends.
915
916	  If unsure, say N.
917
918config DEBUG_NOMMU_REGIONS
919	bool "Debug the global anon/private NOMMU mapping region tree"
920	depends on DEBUG_KERNEL && !MMU
921	help
922	  This option causes the global tree of anonymous and private mapping
923	  regions to be regularly checked for invalid topology.
924
925config DEBUG_MEMORY_INIT
926	bool "Debug memory initialisation" if EXPERT
927	default !EXPERT
928	help
929	  Enable this for additional checks during memory initialisation.
930	  The sanity checks verify aspects of the VM such as the memory model
931	  and other information provided by the architecture. Verbose
932	  information will be printed at KERN_DEBUG loglevel depending
933	  on the mminit_loglevel= command-line option.
934
935	  If unsure, say Y
936
937config MEMORY_NOTIFIER_ERROR_INJECT
938	tristate "Memory hotplug notifier error injection module"
939	depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
940	help
941	  This option provides the ability to inject artificial errors to
942	  memory hotplug notifier chain callbacks.  It is controlled through
943	  debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
944
945	  If the notifier call chain should be failed with some events
946	  notified, write the error code to "actions/<notifier event>/error".
947
948	  Example: Inject memory hotplug offline error (-12 == -ENOMEM)
949
950	  # cd /sys/kernel/debug/notifier-error-inject/memory
951	  # echo -12 > actions/MEM_GOING_OFFLINE/error
952	  # echo offline > /sys/devices/system/memory/memoryXXX/state
953	  bash: echo: write error: Cannot allocate memory
954
955	  To compile this code as a module, choose M here: the module will
956	  be called memory-notifier-error-inject.
957
958	  If unsure, say N.
959
960config DEBUG_PER_CPU_MAPS
961	bool "Debug access to per_cpu maps"
962	depends on DEBUG_KERNEL
963	depends on SMP
964	help
965	  Say Y to verify that the per_cpu map being accessed has
966	  been set up. This adds a fair amount of code to kernel memory
967	  and decreases performance.
968
969	  Say N if unsure.
970
971config DEBUG_KMAP_LOCAL
972	bool "Debug kmap_local temporary mappings"
973	depends on DEBUG_KERNEL && KMAP_LOCAL
974	help
975	  This option enables additional error checking for the kmap_local
976	  infrastructure.  Disable for production use.
977
978config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
979	bool
980
981config DEBUG_KMAP_LOCAL_FORCE_MAP
982	bool "Enforce kmap_local temporary mappings"
983	depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
984	select KMAP_LOCAL
985	select DEBUG_KMAP_LOCAL
986	help
987	  This option enforces temporary mappings through the kmap_local
988	  mechanism for non-highmem pages and on non-highmem systems.
989	  Disable this for production systems!
990
991config DEBUG_HIGHMEM
992	bool "Highmem debugging"
993	depends on DEBUG_KERNEL && HIGHMEM
994	select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
995	select DEBUG_KMAP_LOCAL
996	help
997	  This option enables additional error checking for high memory
998	  systems.  Disable for production systems.
999
1000config HAVE_DEBUG_STACKOVERFLOW
1001	bool
1002
1003config DEBUG_STACKOVERFLOW
1004	bool "Check for stack overflows"
1005	depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
1006	help
1007	  Say Y here if you want to check for overflows of kernel, IRQ
1008	  and exception stacks (if your architecture uses them). This
1009	  option will show detailed messages if free stack space drops
1010	  below a certain limit.
1011
1012	  These kinds of bugs usually occur when call-chains in the
1013	  kernel get too deep, especially when interrupts are
1014	  involved.
1015
1016	  Use this in cases where you see apparently random memory
1017	  corruption, especially if it appears in 'struct thread_info'
1018
1019	  If in doubt, say "N".
1020
1021config CODE_TAGGING
1022	bool
1023	select KALLSYMS
1024
1025config MEM_ALLOC_PROFILING
1026	bool "Enable memory allocation profiling"
1027	default n
1028	depends on MMU
1029	depends on PROC_FS
1030	depends on !DEBUG_FORCE_WEAK_PER_CPU
1031	select CODE_TAGGING
1032	select PAGE_EXTENSION
1033	select SLAB_OBJ_EXT
1034	help
1035	  Track allocation source code and record total allocation size
1036	  initiated at that code location. The mechanism can be used to track
1037	  memory leaks with a low performance and memory impact.
1038
1039config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
1040	bool "Enable memory allocation profiling by default"
1041	default y
1042	depends on MEM_ALLOC_PROFILING
1043
1044config MEM_ALLOC_PROFILING_DEBUG
1045	bool "Memory allocation profiler debugging"
1046	default n
1047	depends on MEM_ALLOC_PROFILING
1048	select MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
1049	help
1050	  Adds warnings with helpful error messages for memory allocation
1051	  profiling.
1052
1053source "lib/Kconfig.kasan"
1054source "lib/Kconfig.kfence"
1055source "lib/Kconfig.kmsan"
1056
1057endmenu # "Memory Debugging"
1058
1059config DEBUG_SHIRQ
1060	bool "Debug shared IRQ handlers"
1061	depends on DEBUG_KERNEL
1062	help
1063	  Enable this to generate a spurious interrupt just before a shared
1064	  interrupt handler is deregistered (generating one when registering
1065	  is currently disabled). Drivers need to handle this correctly. Some
1066	  don't and need to be caught.
1067
1068menu "Debug Oops, Lockups and Hangs"
1069
1070config PANIC_ON_OOPS
1071	bool "Panic on Oops"
1072	help
1073	  Say Y here to enable the kernel to panic when it oopses. This
1074	  has the same effect as setting oops=panic on the kernel command
1075	  line.
1076
1077	  This feature is useful to ensure that the kernel does not do
1078	  anything erroneous after an oops which could result in data
1079	  corruption or other issues.
1080
1081	  Say N if unsure.
1082
1083config PANIC_TIMEOUT
1084	int "panic timeout"
1085	default 0
1086	help
1087	  Set the timeout value (in seconds) until a reboot occurs when
1088	  the kernel panics. If n = 0, then we wait forever. A timeout
1089	  value n > 0 will wait n seconds before rebooting, while a timeout
1090	  value n < 0 will reboot immediately. This setting can be overridden
1091	  with the kernel command line option panic=, and from userspace via
1092	  /proc/sys/kernel/panic.
1093
1094config LOCKUP_DETECTOR
1095	bool
1096
1097config SOFTLOCKUP_DETECTOR
1098	bool "Detect Soft Lockups"
1099	depends on DEBUG_KERNEL && !S390
1100	select LOCKUP_DETECTOR
1101	help
1102	  Say Y here to enable the kernel to act as a watchdog to detect
1103	  soft lockups.
1104
1105	  Softlockups are bugs that cause the kernel to loop in kernel
1106	  mode for more than 20 seconds, without giving other tasks a
1107	  chance to run.  The current stack trace is displayed upon
1108	  detection and the system will stay locked up.
1109
1110config SOFTLOCKUP_DETECTOR_INTR_STORM
1111	bool "Detect Interrupt Storm in Soft Lockups"
1112	depends on SOFTLOCKUP_DETECTOR && IRQ_TIME_ACCOUNTING
1113	select GENERIC_IRQ_STAT_SNAPSHOT
1114	default y if NR_CPUS <= 128
1115	help
1116	  Say Y here to enable the kernel to detect interrupt storm
1117	  during "soft lockups".
1118
1119	  "soft lockups" can be caused by a variety of reasons. If one is
1120	  caused by an interrupt storm, then the storming interrupts will not
1121	  be on the callstack. To detect this case, it is necessary to report
1122	  the CPU stats and the interrupt counts during the "soft lockups".
1123
1124config BOOTPARAM_SOFTLOCKUP_PANIC
1125	bool "Panic (Reboot) On Soft Lockups"
1126	depends on SOFTLOCKUP_DETECTOR
1127	help
1128	  Say Y here to enable the kernel to panic on "soft lockups",
1129	  which are bugs that cause the kernel to loop in kernel
1130	  mode for more than 20 seconds (configurable using the watchdog_thresh
1131	  sysctl), without giving other tasks a chance to run.
1132
1133	  The panic can be used in combination with panic_timeout,
1134	  to cause the system to reboot automatically after a
1135	  lockup has been detected. This feature is useful for
1136	  high-availability systems that have uptime guarantees and
1137	  where a lockup must be resolved ASAP.
1138
1139	  Say N if unsure.
1140
1141config HAVE_HARDLOCKUP_DETECTOR_BUDDY
1142	bool
1143	depends on SMP
1144	default y
1145
1146#
1147# Global switch whether to build a hardlockup detector at all. It is available
1148# only when the architecture supports at least one implementation. There are
1149# two exceptions. The hardlockup detector is never enabled on:
1150#
1151#	s390: it reported many false positives there
1152#
1153#	sparc64: has a custom implementation which is not using the common
1154#		hardlockup command line options and sysctl interface.
1155#
1156config HARDLOCKUP_DETECTOR
1157	bool "Detect Hard Lockups"
1158	depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
1159	depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1160	imply HARDLOCKUP_DETECTOR_PERF
1161	imply HARDLOCKUP_DETECTOR_BUDDY
1162	imply HARDLOCKUP_DETECTOR_ARCH
1163	select LOCKUP_DETECTOR
1164
1165	help
1166	  Say Y here to enable the kernel to act as a watchdog to detect
1167	  hard lockups.
1168
1169	  Hardlockups are bugs that cause the CPU to loop in kernel mode
1170	  for more than 10 seconds, without letting other interrupts have a
1171	  chance to run.  The current stack trace is displayed upon detection
1172	  and the system will stay locked up.
1173
1174#
1175# Note that arch-specific variants are always preferred.
1176#
1177config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1178	bool "Prefer the buddy CPU hardlockup detector"
1179	depends on HARDLOCKUP_DETECTOR
1180	depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
1181	depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1182	help
1183	  Say Y here to prefer the buddy hardlockup detector over the perf one.
1184
1185	  With the buddy detector, each CPU uses its softlockup hrtimer
1186	  to check that the next CPU is processing hrtimer interrupts by
1187	  verifying that a counter is increasing.
1188
1189	  This hardlockup detector is useful on systems that don't have
1190	  an arch-specific hardlockup detector or if resources needed
1191	  for the hardlockup detector are better used for other things.
1192
1193config HARDLOCKUP_DETECTOR_PERF
1194	bool
1195	depends on HARDLOCKUP_DETECTOR
1196	depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
1197	depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1198	select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1199
1200config HARDLOCKUP_DETECTOR_BUDDY
1201	bool
1202	depends on HARDLOCKUP_DETECTOR
1203	depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1204	depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
1205	depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1206	select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1207
1208config HARDLOCKUP_DETECTOR_ARCH
1209	bool
1210	depends on HARDLOCKUP_DETECTOR
1211	depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1212	help
1213	  The arch-specific implementation of the hardlockup detector will
1214	  be used.
1215
1216#
1217# Both the "perf" and "buddy" hardlockup detectors count hrtimer
1218# interrupts. This config enables functions managing this common code.
1219#
1220config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1221	bool
1222	select SOFTLOCKUP_DETECTOR
1223
1224#
1225# Enables a timestamp based low pass filter to compensate for perf based
1226# hard lockup detection which runs too fast due to turbo modes.
1227#
1228config HARDLOCKUP_CHECK_TIMESTAMP
1229	bool
1230
1231config BOOTPARAM_HARDLOCKUP_PANIC
1232	bool "Panic (Reboot) On Hard Lockups"
1233	depends on HARDLOCKUP_DETECTOR
1234	help
1235	  Say Y here to enable the kernel to panic on "hard lockups",
1236	  which are bugs that cause the kernel to loop in kernel
1237	  mode with interrupts disabled for more than 10 seconds (configurable
1238	  using the watchdog_thresh sysctl).
1239
1240	  Say N if unsure.
1241
1242config DETECT_HUNG_TASK
1243	bool "Detect Hung Tasks"
1244	depends on DEBUG_KERNEL
1245	default SOFTLOCKUP_DETECTOR
1246	help
1247	  Say Y here to enable the kernel to detect "hung tasks",
1248	  which are bugs that cause the task to be stuck in
1249	  uninterruptible "D" state indefinitely.
1250
1251	  When a hung task is detected, the kernel will print the
1252	  current stack trace (which you should report), but the
1253	  task will stay in uninterruptible state. If lockdep is
1254	  enabled then all held locks will also be reported. This
1255	  feature has negligible overhead.
1256
1257config DEFAULT_HUNG_TASK_TIMEOUT
1258	int "Default timeout for hung task detection (in seconds)"
1259	depends on DETECT_HUNG_TASK
1260	default 120
1261	help
1262	  This option controls the default timeout (in seconds) used
1263	  to determine when a task has become non-responsive and should
1264	  be considered hung.
1265
1266	  It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1267	  sysctl or by writing a value to
1268	  /proc/sys/kernel/hung_task_timeout_secs.
1269
1270	  A timeout of 0 disables the check.  The default is two minutes.
1271	  Keeping the default should be fine in most cases.
1272
1273config BOOTPARAM_HUNG_TASK_PANIC
1274	int "Number of hung tasks to trigger kernel panic"
1275	depends on DETECT_HUNG_TASK
1276	default 0
1277	help
1278	  When set to a non-zero value, a kernel panic will be triggered
1279	  if the number of hung tasks found during a single scan reaches
1280	  this value.
1281
1282	  The panic can be used in combination with panic_timeout,
1283	  to cause the system to reboot automatically after a
1284	  hung task has been detected. This feature is useful for
1285	  high-availability systems that have uptime guarantees and
1286	  where a hung tasks must be resolved ASAP.
1287
1288	  Say N if unsure.
1289
1290config DETECT_HUNG_TASK_BLOCKER
1291	bool "Dump Hung Tasks Blocker"
1292	depends on DETECT_HUNG_TASK
1293	depends on !PREEMPT_RT
1294	default y
1295	help
1296	  Say Y here to show the blocker task's stacktrace who acquires
1297	  the mutex lock which "hung tasks" are waiting.
1298	  This will add overhead a bit but shows suspicious tasks and
1299	  call trace if it comes from waiting a mutex.
1300
1301config WQ_WATCHDOG
1302	bool "Detect Workqueue Stalls"
1303	depends on DEBUG_KERNEL
1304	help
1305	  Say Y here to enable stall detection on workqueues.  If a
1306	  worker pool doesn't make forward progress on a pending work
1307	  item for over a given amount of time, 30s by default, a
1308	  warning message is printed along with dump of workqueue
1309	  state.  This can be configured through kernel parameter
1310	  "workqueue.watchdog_thresh" and its sysfs counterpart.
1311
1312config WQ_CPU_INTENSIVE_REPORT
1313	bool "Report per-cpu work items which hog CPU for too long"
1314	depends on DEBUG_KERNEL
1315	help
1316	  Say Y here to enable reporting of concurrency-managed per-cpu work
1317	  items that hog CPUs for longer than
1318	  workqueue.cpu_intensive_thresh_us. Workqueue automatically
1319	  detects and excludes them from concurrency management to prevent
1320	  them from stalling other per-cpu work items. Occassional
1321	  triggering may not necessarily indicate a problem. Repeated
1322	  triggering likely indicates that the work item should be switched
1323	  to use an unbound workqueue.
1324
1325config TEST_LOCKUP
1326	tristate "Test module to generate lockups"
1327	depends on m
1328	help
1329	  This builds the "test_lockup" module that helps to make sure
1330	  that watchdogs and lockup detectors are working properly.
1331
1332	  Depending on module parameters it could emulate soft or hard
1333	  lockup, "hung task", or locking arbitrary lock for a long time.
1334	  Also it could generate series of lockups with cooling-down periods.
1335
1336	  If unsure, say N.
1337
1338endmenu # "Debug lockups and hangs"
1339
1340menu "Scheduler Debugging"
1341
1342config SCHED_INFO
1343	bool
1344	default n
1345
1346config SCHEDSTATS
1347	bool "Collect scheduler statistics"
1348	depends on PROC_FS
1349	select SCHED_INFO
1350	help
1351	  If you say Y here, additional code will be inserted into the
1352	  scheduler and related routines to collect statistics about
1353	  scheduler behavior and provide them in /proc/schedstat.  These
1354	  stats may be useful for both tuning and debugging the scheduler
1355	  If you aren't debugging the scheduler or trying to tune a specific
1356	  application, you can say N to avoid the very slight overhead
1357	  this adds.
1358
1359endmenu
1360
1361config DEBUG_PREEMPT
1362	bool "Debug preemptible kernel"
1363	depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1364	help
1365	  If you say Y here then the kernel will use a debug variant of the
1366	  commonly used smp_processor_id() function and will print warnings
1367	  if kernel code uses it in a preemption-unsafe way. Also, the kernel
1368	  will detect preemption count underflows.
1369
1370	  This option has potential to introduce high runtime overhead,
1371	  depending on workload as it triggers debugging routines for each
1372	  this_cpu operation. It should only be used for debugging purposes.
1373
1374menu "Lock Debugging (spinlocks, mutexes, etc...)"
1375
1376config LOCK_DEBUGGING_SUPPORT
1377	bool
1378	depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1379	default y
1380
1381config PROVE_LOCKING
1382	bool "Lock debugging: prove locking correctness"
1383	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1384	select LOCKDEP
1385	select DEBUG_SPINLOCK
1386	select DEBUG_MUTEXES if !PREEMPT_RT
1387	select DEBUG_RT_MUTEXES if RT_MUTEXES
1388	select DEBUG_RWSEMS if !PREEMPT_RT
1389	select DEBUG_WW_MUTEX_SLOWPATH
1390	select DEBUG_LOCK_ALLOC
1391	select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1392	select TRACE_IRQFLAGS
1393	default n
1394	help
1395	 This feature enables the kernel to prove that all locking
1396	 that occurs in the kernel runtime is mathematically
1397	 correct: that under no circumstance could an arbitrary (and
1398	 not yet triggered) combination of observed locking
1399	 sequences (on an arbitrary number of CPUs, running an
1400	 arbitrary number of tasks and interrupt contexts) cause a
1401	 deadlock.
1402
1403	 In short, this feature enables the kernel to report locking
1404	 related deadlocks before they actually occur.
1405
1406	 The proof does not depend on how hard and complex a
1407	 deadlock scenario would be to trigger: how many
1408	 participant CPUs, tasks and irq-contexts would be needed
1409	 for it to trigger. The proof also does not depend on
1410	 timing: if a race and a resulting deadlock is possible
1411	 theoretically (no matter how unlikely the race scenario
1412	 is), it will be proven so and will immediately be
1413	 reported by the kernel (once the event is observed that
1414	 makes the deadlock theoretically possible).
1415
1416	 If a deadlock is impossible (i.e. the locking rules, as
1417	 observed by the kernel, are mathematically correct), the
1418	 kernel reports nothing.
1419
1420	 NOTE: this feature can also be enabled for rwlocks, mutexes
1421	 and rwsems - in which case all dependencies between these
1422	 different locking variants are observed and mapped too, and
1423	 the proof of observed correctness is also maintained for an
1424	 arbitrary combination of these separate locking variants.
1425
1426	 For more details, see Documentation/locking/lockdep-design.rst.
1427
1428config PROVE_RAW_LOCK_NESTING
1429	bool "Enable raw_spinlock - spinlock nesting checks" if !ARCH_SUPPORTS_RT
1430	depends on PROVE_LOCKING
1431	default y if ARCH_SUPPORTS_RT
1432	help
1433	 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1434	 that the lock nesting rules for PREEMPT_RT enabled kernels are
1435	 not violated.
1436
1437config LOCK_STAT
1438	bool "Lock usage statistics"
1439	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1440	select LOCKDEP
1441	select DEBUG_SPINLOCK
1442	select DEBUG_MUTEXES if !PREEMPT_RT
1443	select DEBUG_RT_MUTEXES if RT_MUTEXES
1444	select DEBUG_LOCK_ALLOC
1445	default n
1446	help
1447	 This feature enables tracking lock contention points
1448
1449	 For more details, see Documentation/locking/lockstat.rst
1450
1451	 This also enables lock events required by "perf lock",
1452	 subcommand of perf.
1453	 If you want to use "perf lock", you also need to turn on
1454	 CONFIG_EVENT_TRACING.
1455
1456	 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1457	 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1458
1459config DEBUG_RT_MUTEXES
1460	bool "RT Mutex debugging, deadlock detection"
1461	depends on DEBUG_KERNEL && RT_MUTEXES
1462	help
1463	 This allows rt mutex semantics violations and rt mutex related
1464	 deadlocks (lockups) to be detected and reported automatically.
1465
1466config DEBUG_SPINLOCK
1467	bool "Spinlock and rw-lock debugging: basic checks"
1468	depends on DEBUG_KERNEL
1469	select UNINLINE_SPIN_UNLOCK
1470	help
1471	  Say Y here and build SMP to catch missing spinlock initialization
1472	  and certain other kinds of spinlock errors commonly made.  This is
1473	  best used in conjunction with the NMI watchdog so that spinlock
1474	  deadlocks are also debuggable.
1475
1476config DEBUG_MUTEXES
1477	bool "Mutex debugging: basic checks"
1478	depends on DEBUG_KERNEL && !PREEMPT_RT
1479	help
1480	 This feature allows mutex semantics violations to be detected and
1481	 reported.
1482
1483config DEBUG_WW_MUTEX_SLOWPATH
1484	bool "Wait/wound mutex debugging: Slowpath testing"
1485	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1486	select DEBUG_LOCK_ALLOC
1487	select DEBUG_SPINLOCK
1488	select DEBUG_MUTEXES if !PREEMPT_RT
1489	select DEBUG_RT_MUTEXES if PREEMPT_RT
1490	help
1491	 This feature enables slowpath testing for w/w mutex users by
1492	 injecting additional -EDEADLK wound/backoff cases. Together with
1493	 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1494	 will test all possible w/w mutex interface abuse with the
1495	 exception of simply not acquiring all the required locks.
1496	 Note that this feature can introduce significant overhead, so
1497	 it really should not be enabled in a production or distro kernel,
1498	 even a debug kernel.  If you are a driver writer, enable it.  If
1499	 you are a distro, do not.
1500
1501config DEBUG_RWSEMS
1502	bool "RW Semaphore debugging: basic checks"
1503	depends on DEBUG_KERNEL && !PREEMPT_RT
1504	help
1505	  This debugging feature allows mismatched rw semaphore locks
1506	  and unlocks to be detected and reported.
1507
1508config DEBUG_LOCK_ALLOC
1509	bool "Lock debugging: detect incorrect freeing of live locks"
1510	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1511	select DEBUG_SPINLOCK
1512	select DEBUG_MUTEXES if !PREEMPT_RT
1513	select DEBUG_RT_MUTEXES if RT_MUTEXES
1514	select LOCKDEP
1515	help
1516	 This feature will check whether any held lock (spinlock, rwlock,
1517	 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1518	 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1519	 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1520	 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1521	 held during task exit.
1522
1523config LOCKDEP
1524	bool
1525	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1526	select STACKTRACE
1527	select KALLSYMS
1528	select KALLSYMS_ALL
1529
1530config LOCKDEP_SMALL
1531	bool
1532
1533config LOCKDEP_BITS
1534	int "Size for MAX_LOCKDEP_ENTRIES (as Nth power of 2)"
1535	depends on LOCKDEP && !LOCKDEP_SMALL
1536	range 10 24
1537	default 15
1538	help
1539	  Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1540
1541config LOCKDEP_CHAINS_BITS
1542	int "Size for MAX_LOCKDEP_CHAINS (as Nth power of 2)"
1543	depends on LOCKDEP && !LOCKDEP_SMALL
1544	range 10 21
1545	default 16
1546	help
1547	  Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1548
1549config LOCKDEP_STACK_TRACE_BITS
1550	int "Size for MAX_STACK_TRACE_ENTRIES (as Nth power of 2)"
1551	depends on LOCKDEP && !LOCKDEP_SMALL
1552	range 10 26
1553	default 19
1554	help
1555	  Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1556
1557config LOCKDEP_STACK_TRACE_HASH_BITS
1558	int "Size for STACK_TRACE_HASH_SIZE (as Nth power of 2)"
1559	depends on LOCKDEP && !LOCKDEP_SMALL
1560	range 10 26
1561	default 14
1562	help
1563	  Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1564
1565config LOCKDEP_CIRCULAR_QUEUE_BITS
1566	int "Size for elements in circular_queue struct (as Nth power of 2)"
1567	depends on LOCKDEP
1568	range 10 26
1569	default 12
1570	help
1571	  Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1572
1573config DEBUG_LOCKDEP
1574	bool "Lock dependency engine debugging"
1575	depends on DEBUG_KERNEL && LOCKDEP
1576	select DEBUG_IRQFLAGS
1577	help
1578	  If you say Y here, the lock dependency engine will do
1579	  additional runtime checks to debug itself, at the price
1580	  of more runtime overhead.
1581
1582config DEBUG_ATOMIC_SLEEP
1583	bool "Sleep inside atomic section checking"
1584	select PREEMPT_COUNT
1585	depends on DEBUG_KERNEL
1586	depends on !ARCH_NO_PREEMPT
1587	help
1588	  If you say Y here, various routines which may sleep will become very
1589	  noisy if they are called inside atomic sections: when a spinlock is
1590	  held, inside an rcu read side critical section, inside preempt disabled
1591	  sections, inside an interrupt, etc...
1592
1593config DEBUG_LOCKING_API_SELFTESTS
1594	bool "Locking API boot-time self-tests"
1595	depends on DEBUG_KERNEL
1596	help
1597	  Say Y here if you want the kernel to run a short self-test during
1598	  bootup. The self-test checks whether common types of locking bugs
1599	  are detected by debugging mechanisms or not. (if you disable
1600	  lock debugging then those bugs won't be detected of course.)
1601	  The following locking APIs are covered: spinlocks, rwlocks,
1602	  mutexes and rwsems.
1603
1604config LOCK_TORTURE_TEST
1605	tristate "torture tests for locking"
1606	depends on DEBUG_KERNEL
1607	select TORTURE_TEST
1608	help
1609	  This option provides a kernel module that runs torture tests
1610	  on kernel locking primitives.  The kernel module may be built
1611	  after the fact on the running kernel to be tested, if desired.
1612
1613	  Say Y here if you want kernel locking-primitive torture tests
1614	  to be built into the kernel.
1615	  Say M if you want these torture tests to build as a module.
1616	  Say N if you are unsure.
1617
1618config WW_MUTEX_SELFTEST
1619	tristate "Wait/wound mutex selftests"
1620	help
1621	  This option provides a kernel module that runs tests on the
1622	  on the struct ww_mutex locking API.
1623
1624	  It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1625	  with this test harness.
1626
1627	  Say M if you want these self tests to build as a module.
1628	  Say N if you are unsure.
1629
1630config SCF_TORTURE_TEST
1631	tristate "torture tests for smp_call_function*()"
1632	depends on DEBUG_KERNEL
1633	select TORTURE_TEST
1634	help
1635	  This option provides a kernel module that runs torture tests
1636	  on the smp_call_function() family of primitives.  The kernel
1637	  module may be built after the fact on the running kernel to
1638	  be tested, if desired.
1639
1640config CSD_LOCK_WAIT_DEBUG
1641	bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1642	depends on DEBUG_KERNEL
1643	depends on SMP
1644	depends on 64BIT
1645	default n
1646	help
1647	  This option enables debug prints when CPUs are slow to respond
1648	  to the smp_call_function*() IPI wrappers.  These debug prints
1649	  include the IPI handler function currently executing (if any)
1650	  and relevant stack traces.
1651
1652config CSD_LOCK_WAIT_DEBUG_DEFAULT
1653	bool "Default csd_lock_wait() debugging on at boot time"
1654	depends on CSD_LOCK_WAIT_DEBUG
1655	depends on 64BIT
1656	default n
1657	help
1658	  This option causes the csdlock_debug= kernel boot parameter to
1659	  default to 1 (basic debugging) instead of 0 (no debugging).
1660
1661endmenu # lock debugging
1662
1663config TRACE_IRQFLAGS
1664	depends on TRACE_IRQFLAGS_SUPPORT
1665	bool
1666	help
1667	  Enables hooks to interrupt enabling and disabling for
1668	  either tracing or lock debugging.
1669
1670config TRACE_IRQFLAGS_NMI
1671	def_bool y
1672	depends on TRACE_IRQFLAGS
1673	depends on TRACE_IRQFLAGS_NMI_SUPPORT
1674
1675config NMI_CHECK_CPU
1676	bool "Debugging for CPUs failing to respond to backtrace requests"
1677	depends on DEBUG_KERNEL
1678	depends on X86
1679	default n
1680	help
1681	  Enables debug prints when a CPU fails to respond to a given
1682	  backtrace NMI.  These prints provide some reasons why a CPU
1683	  might legitimately be failing to respond, for example, if it
1684	  is offline of if ignore_nmis is set.
1685
1686config DEBUG_IRQFLAGS
1687	bool "Debug IRQ flag manipulation"
1688	help
1689	  Enables checks for potentially unsafe enabling or disabling of
1690	  interrupts, such as calling raw_local_irq_restore() when interrupts
1691	  are enabled.
1692
1693config STACKTRACE
1694	bool "Stack backtrace support"
1695	depends on STACKTRACE_SUPPORT
1696	help
1697	  This option causes the kernel to create a /proc/pid/stack for
1698	  every process, showing its current stack trace.
1699	  It is also used by various kernel debugging features that require
1700	  stack trace generation.
1701
1702config WARN_ALL_UNSEEDED_RANDOM
1703	bool "Warn for all uses of unseeded randomness"
1704	default n
1705	help
1706	  Some parts of the kernel contain bugs relating to their use of
1707	  cryptographically secure random numbers before it's actually possible
1708	  to generate those numbers securely. This setting ensures that these
1709	  flaws don't go unnoticed, by enabling a message, should this ever
1710	  occur. This will allow people with obscure setups to know when things
1711	  are going wrong, so that they might contact developers about fixing
1712	  it.
1713
1714	  Unfortunately, on some models of some architectures getting
1715	  a fully seeded CRNG is extremely difficult, and so this can
1716	  result in dmesg getting spammed for a surprisingly long
1717	  time.  This is really bad from a security perspective, and
1718	  so architecture maintainers really need to do what they can
1719	  to get the CRNG seeded sooner after the system is booted.
1720	  However, since users cannot do anything actionable to
1721	  address this, by default this option is disabled.
1722
1723	  Say Y here if you want to receive warnings for all uses of
1724	  unseeded randomness.  This will be of use primarily for
1725	  those developers interested in improving the security of
1726	  Linux kernels running on their architecture (or
1727	  subarchitecture).
1728
1729config DEBUG_KOBJECT
1730	bool "kobject debugging"
1731	depends on DEBUG_KERNEL
1732	help
1733	  If you say Y here, some extra kobject debugging messages will be sent
1734	  to the syslog.
1735
1736config DEBUG_KOBJECT_RELEASE
1737	bool "kobject release debugging"
1738	depends on DEBUG_OBJECTS_TIMERS
1739	help
1740	  kobjects are reference counted objects.  This means that their
1741	  last reference count put is not predictable, and the kobject can
1742	  live on past the point at which a driver decides to drop its
1743	  initial reference to the kobject gained on allocation.  An
1744	  example of this would be a struct device which has just been
1745	  unregistered.
1746
1747	  However, some buggy drivers assume that after such an operation,
1748	  the memory backing the kobject can be immediately freed.  This
1749	  goes completely against the principles of a refcounted object.
1750
1751	  If you say Y here, the kernel will delay the release of kobjects
1752	  on the last reference count to improve the visibility of this
1753	  kind of kobject release bug.
1754
1755config HAVE_DEBUG_BUGVERBOSE
1756	bool
1757
1758menu "Debug kernel data structures"
1759
1760config DEBUG_LIST
1761	bool "Debug linked list manipulation"
1762	depends on DEBUG_KERNEL
1763	select LIST_HARDENED
1764	help
1765	  Enable this to turn on extended checks in the linked-list walking
1766	  routines.
1767
1768	  This option trades better quality error reports for performance, and
1769	  is more suitable for kernel debugging. If you care about performance,
1770	  you should only enable CONFIG_LIST_HARDENED instead.
1771
1772	  If unsure, say N.
1773
1774config DEBUG_PLIST
1775	bool "Debug priority linked list manipulation"
1776	depends on DEBUG_KERNEL
1777	help
1778	  Enable this to turn on extended checks in the priority-ordered
1779	  linked-list (plist) walking routines.  This checks the entire
1780	  list multiple times during each manipulation.
1781
1782	  If unsure, say N.
1783
1784config DEBUG_SG
1785	bool "Debug SG table operations"
1786	depends on DEBUG_KERNEL
1787	help
1788	  Enable this to turn on checks on scatter-gather tables. This can
1789	  help find problems with drivers that do not properly initialize
1790	  their sg tables.
1791
1792	  If unsure, say N.
1793
1794config DEBUG_NOTIFIERS
1795	bool "Debug notifier call chains"
1796	depends on DEBUG_KERNEL
1797	help
1798	  Enable this to turn on sanity checking for notifier call chains.
1799	  This is most useful for kernel developers to make sure that
1800	  modules properly unregister themselves from notifier chains.
1801	  This is a relatively cheap check but if you care about maximum
1802	  performance, say N.
1803
1804config DEBUG_CLOSURES
1805	bool "Debug closures (bcache async widgits)"
1806	depends on CLOSURES
1807	select DEBUG_FS
1808	help
1809	  Keeps all active closures in a linked list and provides a debugfs
1810	  interface to list them, which makes it possible to see asynchronous
1811	  operations that get stuck.
1812
1813config DEBUG_MAPLE_TREE
1814	bool "Debug maple trees"
1815	depends on DEBUG_KERNEL
1816	help
1817	  Enable maple tree debugging information and extra validations.
1818
1819	  If unsure, say N.
1820
1821endmenu
1822
1823source "kernel/rcu/Kconfig.debug"
1824
1825config DEBUG_WQ_FORCE_RR_CPU
1826	bool "Force round-robin CPU selection for unbound work items"
1827	depends on DEBUG_KERNEL
1828	default n
1829	help
1830	  Workqueue used to implicitly guarantee that work items queued
1831	  without explicit CPU specified are put on the local CPU.  This
1832	  guarantee is no longer true and while local CPU is still
1833	  preferred work items may be put on foreign CPUs.  Kernel
1834	  parameter "workqueue.debug_force_rr_cpu" is added to force
1835	  round-robin CPU selection to flush out usages which depend on the
1836	  now broken guarantee.  This config option enables the debug
1837	  feature by default.  When enabled, memory and cache locality will
1838	  be impacted.
1839
1840config CPU_HOTPLUG_STATE_CONTROL
1841	bool "Enable CPU hotplug state control"
1842	depends on DEBUG_KERNEL
1843	depends on HOTPLUG_CPU
1844	default n
1845	help
1846	  Allows to write steps between "offline" and "online" to the CPUs
1847	  sysfs target file so states can be stepped granular. This is a debug
1848	  option for now as the hotplug machinery cannot be stopped and
1849	  restarted at arbitrary points yet.
1850
1851	  Say N if your are unsure.
1852
1853config LATENCYTOP
1854	bool "Latency measuring infrastructure"
1855	depends on DEBUG_KERNEL
1856	depends on STACKTRACE_SUPPORT
1857	depends on PROC_FS
1858	depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1859	select KALLSYMS
1860	select KALLSYMS_ALL
1861	select STACKTRACE
1862	select SCHEDSTATS
1863	help
1864	  Enable this option if you want to use the LatencyTOP tool
1865	  to find out which userspace is blocking on what kernel operations.
1866
1867config DEBUG_CGROUP_REF
1868	bool "Disable inlining of cgroup css reference count functions"
1869	depends on DEBUG_KERNEL
1870	depends on CGROUPS
1871	depends on KPROBES
1872	default n
1873	help
1874	  Force cgroup css reference count functions to not be inlined so
1875	  that they can be kprobed for debugging.
1876
1877source "kernel/trace/Kconfig"
1878
1879config PROVIDE_OHCI1394_DMA_INIT
1880	bool "Remote debugging over FireWire early on boot"
1881	depends on PCI && X86
1882	help
1883	  If you want to debug problems which hang or crash the kernel early
1884	  on boot and the crashing machine has a FireWire port, you can use
1885	  this feature to remotely access the memory of the crashed machine
1886	  over FireWire. This employs remote DMA as part of the OHCI1394
1887	  specification which is now the standard for FireWire controllers.
1888
1889	  With remote DMA, you can monitor the printk buffer remotely using
1890	  firescope and access all memory below 4GB using fireproxy from gdb.
1891	  Even controlling a kernel debugger is possible using remote DMA.
1892
1893	  Usage:
1894
1895	  If ohci1394_dma=early is used as boot parameter, it will initialize
1896	  all OHCI1394 controllers which are found in the PCI config space.
1897
1898	  As all changes to the FireWire bus such as enabling and disabling
1899	  devices cause a bus reset and thereby disable remote DMA for all
1900	  devices, be sure to have the cable plugged and FireWire enabled on
1901	  the debugging host before booting the debug target for debugging.
1902
1903	  This code (~1k) is freed after boot. By then, the firewire stack
1904	  in charge of the OHCI-1394 controllers should be used instead.
1905
1906	  See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1907
1908source "samples/Kconfig"
1909
1910config ARCH_HAS_DEVMEM_IS_ALLOWED
1911	bool
1912
1913config STRICT_DEVMEM
1914	bool "Filter access to /dev/mem"
1915	depends on MMU && DEVMEM
1916	depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1917	default y if PPC || X86 || ARM64 || S390
1918	help
1919	  If this option is disabled, you allow userspace (root) access to all
1920	  of memory, including kernel and userspace memory. Accidental
1921	  access to this is obviously disastrous, but specific access can
1922	  be used by people debugging the kernel. Note that with PAT support
1923	  enabled, even in this case there are restrictions on /dev/mem
1924	  use due to the cache aliasing requirements.
1925
1926	  If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1927	  file only allows userspace access to PCI space and the BIOS code and
1928	  data regions.  This is sufficient for dosemu and X and all common
1929	  users of /dev/mem.
1930
1931	  If in doubt, say Y.
1932
1933config IO_STRICT_DEVMEM
1934	bool "Filter I/O access to /dev/mem"
1935	depends on STRICT_DEVMEM
1936	help
1937	  If this option is disabled, you allow userspace (root) access to all
1938	  io-memory regardless of whether a driver is actively using that
1939	  range.  Accidental access to this is obviously disastrous, but
1940	  specific access can be used by people debugging kernel drivers.
1941
1942	  If this option is switched on, the /dev/mem file only allows
1943	  userspace access to *idle* io-memory ranges (see /proc/iomem) This
1944	  may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1945	  if the driver using a given range cannot be disabled.
1946
1947	  If in doubt, say Y.
1948
1949menu "$(SRCARCH) Debugging"
1950
1951source "arch/$(SRCARCH)/Kconfig.debug"
1952
1953endmenu
1954
1955menu "Kernel Testing and Coverage"
1956
1957source "lib/kunit/Kconfig"
1958
1959config NOTIFIER_ERROR_INJECTION
1960	tristate "Notifier error injection"
1961	depends on DEBUG_KERNEL
1962	select DEBUG_FS
1963	help
1964	  This option provides the ability to inject artificial errors to
1965	  specified notifier chain callbacks. It is useful to test the error
1966	  handling of notifier call chain failures.
1967
1968	  Say N if unsure.
1969
1970config PM_NOTIFIER_ERROR_INJECT
1971	tristate "PM notifier error injection module"
1972	depends on PM && NOTIFIER_ERROR_INJECTION
1973	default m if PM_DEBUG
1974	help
1975	  This option provides the ability to inject artificial errors to
1976	  PM notifier chain callbacks.  It is controlled through debugfs
1977	  interface /sys/kernel/debug/notifier-error-inject/pm
1978
1979	  If the notifier call chain should be failed with some events
1980	  notified, write the error code to "actions/<notifier event>/error".
1981
1982	  Example: Inject PM suspend error (-12 = -ENOMEM)
1983
1984	  # cd /sys/kernel/debug/notifier-error-inject/pm/
1985	  # echo -12 > actions/PM_SUSPEND_PREPARE/error
1986	  # echo mem > /sys/power/state
1987	  bash: echo: write error: Cannot allocate memory
1988
1989	  To compile this code as a module, choose M here: the module will
1990	  be called pm-notifier-error-inject.
1991
1992	  If unsure, say N.
1993
1994config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1995	tristate "OF reconfig notifier error injection module"
1996	depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1997	help
1998	  This option provides the ability to inject artificial errors to
1999	  OF reconfig notifier chain callbacks.  It is controlled
2000	  through debugfs interface under
2001	  /sys/kernel/debug/notifier-error-inject/OF-reconfig/
2002
2003	  If the notifier call chain should be failed with some events
2004	  notified, write the error code to "actions/<notifier event>/error".
2005
2006	  To compile this code as a module, choose M here: the module will
2007	  be called of-reconfig-notifier-error-inject.
2008
2009	  If unsure, say N.
2010
2011config NETDEV_NOTIFIER_ERROR_INJECT
2012	tristate "Netdev notifier error injection module"
2013	depends on NET && NOTIFIER_ERROR_INJECTION
2014	help
2015	  This option provides the ability to inject artificial errors to
2016	  netdevice notifier chain callbacks.  It is controlled through debugfs
2017	  interface /sys/kernel/debug/notifier-error-inject/netdev
2018
2019	  If the notifier call chain should be failed with some events
2020	  notified, write the error code to "actions/<notifier event>/error".
2021
2022	  Example: Inject netdevice mtu change error (-22 = -EINVAL)
2023
2024	  # cd /sys/kernel/debug/notifier-error-inject/netdev
2025	  # echo -22 > actions/NETDEV_CHANGEMTU/error
2026	  # ip link set eth0 mtu 1024
2027	  RTNETLINK answers: Invalid argument
2028
2029	  To compile this code as a module, choose M here: the module will
2030	  be called netdev-notifier-error-inject.
2031
2032	  If unsure, say N.
2033
2034config FUNCTION_ERROR_INJECTION
2035	bool "Fault-injections of functions"
2036	depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2037	help
2038	  Add fault injections into various functions that are annotated with
2039	  ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
2040	  value of these functions. This is useful to test error paths of code.
2041
2042	  If unsure, say N
2043
2044config FAULT_INJECTION
2045	bool "Fault-injection framework"
2046	depends on DEBUG_KERNEL
2047	help
2048	  Provide fault-injection framework.
2049	  For more details, see Documentation/fault-injection/.
2050
2051config FAILSLAB
2052	bool "Fault-injection capability for kmalloc"
2053	depends on FAULT_INJECTION
2054	help
2055	  Provide fault-injection capability for kmalloc.
2056
2057config FAIL_PAGE_ALLOC
2058	bool "Fault-injection capability for alloc_pages()"
2059	depends on FAULT_INJECTION
2060	help
2061	  Provide fault-injection capability for alloc_pages().
2062
2063config FAULT_INJECTION_USERCOPY
2064	bool "Fault injection capability for usercopy functions"
2065	depends on FAULT_INJECTION
2066	help
2067	  Provides fault-injection capability to inject failures
2068	  in usercopy functions (copy_from_user(), get_user(), ...).
2069
2070config FAIL_MAKE_REQUEST
2071	bool "Fault-injection capability for disk IO"
2072	depends on FAULT_INJECTION && BLOCK
2073	help
2074	  Provide fault-injection capability for disk IO.
2075
2076config FAIL_IO_TIMEOUT
2077	bool "Fault-injection capability for faking disk interrupts"
2078	depends on FAULT_INJECTION && BLOCK
2079	help
2080	  Provide fault-injection capability on end IO handling. This
2081	  will make the block layer "forget" an interrupt as configured,
2082	  thus exercising the error handling.
2083
2084	  Only works with drivers that use the generic timeout handling,
2085	  for others it won't do anything.
2086
2087config FAIL_FUTEX
2088	bool "Fault-injection capability for futexes"
2089	select DEBUG_FS
2090	depends on FAULT_INJECTION && FUTEX
2091	help
2092	  Provide fault-injection capability for futexes.
2093
2094config FAULT_INJECTION_DEBUG_FS
2095	bool "Debugfs entries for fault-injection capabilities"
2096	depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2097	help
2098	  Enable configuration of fault-injection capabilities via debugfs.
2099
2100config FAIL_FUNCTION
2101	bool "Fault-injection capability for functions"
2102	depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2103	help
2104	  Provide function-based fault-injection capability.
2105	  This will allow you to override a specific function with a return
2106	  with given return value. As a result, function caller will see
2107	  an error value and have to handle it. This is useful to test the
2108	  error handling in various subsystems.
2109
2110config FAIL_MMC_REQUEST
2111	bool "Fault-injection capability for MMC IO"
2112	depends on FAULT_INJECTION_DEBUG_FS && MMC
2113	help
2114	  Provide fault-injection capability for MMC IO.
2115	  This will make the mmc core return data errors. This is
2116	  useful to test the error handling in the mmc block device
2117	  and to test how the mmc host driver handles retries from
2118	  the block device.
2119
2120config FAIL_SUNRPC
2121	bool "Fault-injection capability for SunRPC"
2122	depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2123	help
2124	  Provide fault-injection capability for SunRPC and
2125	  its consumers.
2126
2127config FAIL_SKB_REALLOC
2128	bool "Fault-injection capability forcing skb to reallocate"
2129	depends on FAULT_INJECTION_DEBUG_FS
2130	help
2131	  Provide fault-injection capability that forces the skb to be
2132	  reallocated, catching possible invalid pointers to the skb.
2133
2134	  For more information, check
2135	  Documentation/fault-injection/fault-injection.rst
2136
2137config FAULT_INJECTION_CONFIGFS
2138	bool "Configfs interface for fault-injection capabilities"
2139	depends on FAULT_INJECTION
2140	select CONFIGFS_FS
2141	help
2142	  This option allows configfs-based drivers to dynamically configure
2143	  fault-injection via configfs.  Each parameter for driver-specific
2144	  fault-injection can be made visible as a configfs attribute in a
2145	  configfs group.
2146
2147
2148config FAULT_INJECTION_STACKTRACE_FILTER
2149	bool "stacktrace filter for fault-injection capabilities"
2150	depends on FAULT_INJECTION
2151	depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
2152	select STACKTRACE
2153	depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2154	help
2155	  Provide stacktrace filter for fault-injection capabilities
2156
2157config ARCH_HAS_KCOV
2158	bool
2159	help
2160	  An architecture should select this when it can successfully
2161	  build and run with CONFIG_KCOV. This typically requires
2162	  disabling instrumentation for some early boot code.
2163
2164config KCOV
2165	bool "Code coverage for fuzzing"
2166	depends on ARCH_HAS_KCOV
2167	depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2168		   GCC_VERSION >= 120000 || CC_IS_CLANG
2169	select DEBUG_FS
2170	select OBJTOOL if HAVE_NOINSTR_HACK
2171	help
2172	  KCOV exposes kernel code coverage information in a form suitable
2173	  for coverage-guided fuzzing (randomized testing).
2174
2175	  For more details, see Documentation/dev-tools/kcov.rst.
2176
2177config KCOV_ENABLE_COMPARISONS
2178	bool "Enable comparison operands collection by KCOV"
2179	depends on KCOV
2180	depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2181	help
2182	  KCOV also exposes operands of every comparison in the instrumented
2183	  code along with operand sizes and PCs of the comparison instructions.
2184	  These operands can be used by fuzzing engines to improve the quality
2185	  of fuzzing coverage.
2186
2187config KCOV_INSTRUMENT_ALL
2188	bool "Instrument all code by default"
2189	depends on KCOV
2190	default y
2191	help
2192	  If you are doing generic system call fuzzing (like e.g. syzkaller),
2193	  then you will want to instrument the whole kernel and you should
2194	  say y here. If you are doing more targeted fuzzing (like e.g.
2195	  filesystem fuzzing with AFL) then you will want to enable coverage
2196	  for more specific subsets of files, and should say n here.
2197
2198config KCOV_IRQ_AREA_SIZE
2199	hex "Size of interrupt coverage collection area in words"
2200	depends on KCOV
2201	default 0x40000
2202	help
2203	  KCOV uses preallocated per-cpu areas to collect coverage from
2204	  soft interrupts. This specifies the size of those areas in the
2205	  number of unsigned long words.
2206
2207config KCOV_SELFTEST
2208	bool "Perform short selftests on boot"
2209	depends on KCOV
2210	help
2211	  Run short KCOV coverage collection selftests on boot.
2212	  On test failure, causes the kernel to panic. Recommended to be
2213	  enabled, ensuring critical functionality works as intended.
2214
2215menuconfig RUNTIME_TESTING_MENU
2216	bool "Runtime Testing"
2217	default y
2218
2219if RUNTIME_TESTING_MENU
2220
2221config TEST_DHRY
2222	tristate "Dhrystone benchmark test"
2223	help
2224	  Enable this to include the Dhrystone 2.1 benchmark.  This test
2225	  calculates the number of Dhrystones per second, and the number of
2226	  DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2227	  by 1757 (the number of Dhrystones per second obtained on the VAX
2228	  11/780, nominally a 1 MIPS machine).
2229
2230	  To run the benchmark, it needs to be enabled explicitly, either from
2231	  the kernel command line (when built-in), or from userspace (when
2232	  built-in or modular).
2233
2234	  Run once during kernel boot:
2235
2236	      test_dhry.run
2237
2238	  Set number of iterations from kernel command line:
2239
2240	      test_dhry.iterations=<n>
2241
2242	  Set number of iterations from userspace:
2243
2244	      echo <n> > /sys/module/test_dhry/parameters/iterations
2245
2246	  Trigger manual run from userspace:
2247
2248	      echo y > /sys/module/test_dhry/parameters/run
2249
2250	  If the number of iterations is <= 0, the test will devise a suitable
2251	  number of iterations (test runs for at least 2s) automatically.
2252	  This process takes ca. 4s.
2253
2254	  If unsure, say N.
2255
2256config LKDTM
2257	tristate "Linux Kernel Dump Test Tool Module"
2258	depends on DEBUG_FS
2259	help
2260	This module enables testing of the different dumping mechanisms by
2261	inducing system failures at predefined crash points.
2262	If you don't need it: say N
2263	Choose M here to compile this code as a module. The module will be
2264	called lkdtm.
2265
2266	Documentation on how to use the module can be found in
2267	Documentation/fault-injection/provoke-crashes.rst
2268
2269config CPUMASK_KUNIT_TEST
2270	tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2271	depends on KUNIT
2272	default KUNIT_ALL_TESTS
2273	help
2274	  Enable to turn on cpumask tests, running at boot or module load time.
2275
2276	  For more information on KUnit and unit tests in general, please refer
2277	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2278
2279	  If unsure, say N.
2280
2281config TEST_LIST_SORT
2282	tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2283	depends on KUNIT
2284	default KUNIT_ALL_TESTS
2285	help
2286	  Enable this to turn on 'list_sort()' function test. This test is
2287	  executed only once during system boot (so affects only boot time),
2288	  or at module load time.
2289
2290	  If unsure, say N.
2291
2292config TEST_MIN_HEAP
2293	tristate "Min heap test"
2294	depends on DEBUG_KERNEL || m
2295	help
2296	  Enable this to turn on min heap function tests. This test is
2297	  executed only once during system boot (so affects only boot time),
2298	  or at module load time.
2299
2300	  If unsure, say N.
2301
2302config TEST_SORT
2303	tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2304	depends on KUNIT
2305	default KUNIT_ALL_TESTS
2306	help
2307	  This option enables the self-test function of 'sort()' at boot,
2308	  or at module load time.
2309
2310	  If unsure, say N.
2311
2312config TEST_DIV64
2313	tristate "64bit/32bit division and modulo test"
2314	depends on DEBUG_KERNEL || m
2315	help
2316	  Enable this to turn on 'do_div()' function test. This test is
2317	  executed only once during system boot (so affects only boot time),
2318	  or at module load time.
2319
2320	  If unsure, say N.
2321
2322config TEST_MULDIV64
2323	tristate "mul_u64_u64_div_u64() test"
2324	depends on DEBUG_KERNEL || m
2325	help
2326	  Enable this to turn on 'mul_u64_u64_div_u64()' function test.
2327	  This test is executed only once during system boot (so affects
2328	  only boot time), or at module load time.
2329
2330	  If unsure, say N.
2331
2332config TEST_IOV_ITER
2333	tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2334	depends on KUNIT
2335	depends on MMU
2336	default KUNIT_ALL_TESTS
2337	help
2338	  Enable this to turn on testing of the operation of the I/O iterator
2339	  (iov_iter). This test is executed only once during system boot (so
2340	  affects only boot time), or at module load time.
2341
2342	  If unsure, say N.
2343
2344config KPROBES_SANITY_TEST
2345	tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2346	depends on DEBUG_KERNEL
2347	depends on KPROBES
2348	depends on KUNIT
2349	select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2350	default KUNIT_ALL_TESTS
2351	help
2352	  This option provides for testing basic kprobes functionality on
2353	  boot. Samples of kprobe and kretprobe are inserted and
2354	  verified for functionality.
2355
2356	  Say N if you are unsure.
2357
2358config FPROBE_SANITY_TEST
2359	bool "Self test for fprobe"
2360	depends on DEBUG_KERNEL
2361	depends on FPROBE
2362	depends on KUNIT=y
2363	help
2364	  This option will enable testing the fprobe when the system boot.
2365	  A series of tests are made to verify that the fprobe is functioning
2366	  properly.
2367
2368	  Say N if you are unsure.
2369
2370config BACKTRACE_SELF_TEST
2371	tristate "Self test for the backtrace code"
2372	depends on DEBUG_KERNEL
2373	help
2374	  This option provides a kernel module that can be used to test
2375	  the kernel stack backtrace code. This option is not useful
2376	  for distributions or general kernels, but only for kernel
2377	  developers working on architecture code.
2378
2379	  Note that if you want to also test saved backtraces, you will
2380	  have to enable STACKTRACE as well.
2381
2382	  Say N if you are unsure.
2383
2384config TEST_REF_TRACKER
2385	tristate "Self test for reference tracker"
2386	depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2387	select REF_TRACKER
2388	help
2389	  This option provides a kernel module performing tests
2390	  using reference tracker infrastructure.
2391
2392	  Say N if you are unsure.
2393
2394config RBTREE_TEST
2395	tristate "Red-Black tree test"
2396	depends on DEBUG_KERNEL
2397	help
2398	  A benchmark measuring the performance of the rbtree library.
2399	  Also includes rbtree invariant checks.
2400
2401config REED_SOLOMON_TEST
2402	tristate "Reed-Solomon library test"
2403	depends on DEBUG_KERNEL || m
2404	select REED_SOLOMON
2405	select REED_SOLOMON_ENC16
2406	select REED_SOLOMON_DEC16
2407	help
2408	  This option enables the self-test function of rslib at boot,
2409	  or at module load time.
2410
2411	  If unsure, say N.
2412
2413config INTERVAL_TREE_TEST
2414	tristate "Interval tree test"
2415	depends on DEBUG_KERNEL
2416	select INTERVAL_TREE
2417	help
2418	  A benchmark measuring the performance of the interval tree library
2419
2420config PERCPU_TEST
2421	tristate "Per cpu operations test"
2422	depends on m && DEBUG_KERNEL
2423	help
2424	  Enable this option to build test module which validates per-cpu
2425	  operations.
2426
2427	  If unsure, say N.
2428
2429config ATOMIC64_SELFTEST
2430	tristate "Perform an atomic64_t self-test"
2431	help
2432	  Enable this option to test the atomic64_t functions at boot or
2433	  at module load time.
2434
2435	  If unsure, say N.
2436
2437config ASYNC_RAID6_TEST
2438	tristate "Self test for hardware accelerated raid6 recovery"
2439	depends on ASYNC_RAID6_RECOV
2440	select ASYNC_MEMCPY
2441	help
2442	  This is a one-shot self test that permutes through the
2443	  recovery of all the possible two disk failure scenarios for a
2444	  N-disk array.  Recovery is performed with the asynchronous
2445	  raid6 recovery routines, and will optionally use an offload
2446	  engine if one is available.
2447
2448	  If unsure, say N.
2449
2450config TEST_HEXDUMP
2451	tristate "Test functions located in the hexdump module at runtime"
2452
2453config PRINTF_KUNIT_TEST
2454	tristate "KUnit test printf() family of functions at runtime" if !KUNIT_ALL_TESTS
2455	depends on KUNIT
2456	default KUNIT_ALL_TESTS
2457	help
2458	  Enable this option to test the printf functions at runtime.
2459
2460	  If unsure, say N.
2461
2462config SCANF_KUNIT_TEST
2463	tristate "KUnit test scanf() family of functions at runtime" if !KUNIT_ALL_TESTS
2464	depends on KUNIT
2465	default KUNIT_ALL_TESTS
2466	help
2467	  Enable this option to test the scanf functions at runtime.
2468
2469	  If unsure, say N.
2470
2471config SEQ_BUF_KUNIT_TEST
2472	tristate "KUnit test for seq_buf" if !KUNIT_ALL_TESTS
2473	depends on KUNIT
2474	default KUNIT_ALL_TESTS
2475	help
2476	  This builds unit tests for the seq_buf library.
2477
2478	  If unsure, say N.
2479
2480config STRING_KUNIT_TEST
2481	tristate "KUnit test string functions at runtime" if !KUNIT_ALL_TESTS
2482	depends on KUNIT
2483	default KUNIT_ALL_TESTS
2484
2485config STRING_HELPERS_KUNIT_TEST
2486	tristate "KUnit test string helpers at runtime" if !KUNIT_ALL_TESTS
2487	depends on KUNIT
2488	default KUNIT_ALL_TESTS
2489
2490config FFS_KUNIT_TEST
2491	tristate "KUnit test ffs-family functions at runtime" if !KUNIT_ALL_TESTS
2492	depends on KUNIT
2493	default KUNIT_ALL_TESTS
2494	help
2495	  This builds KUnit tests for ffs-family bit manipulation functions
2496	  including ffs(), __ffs(), fls(), __fls(), fls64(), and __ffs64().
2497
2498	  These tests validate mathematical correctness, edge case handling,
2499	  and cross-architecture consistency of bit scanning functions.
2500
2501	  For more information on KUnit and unit tests in general,
2502	  please refer to Documentation/dev-tools/kunit/.
2503
2504config TEST_KSTRTOX
2505	tristate "Test kstrto*() family of functions at runtime"
2506
2507config TEST_BITMAP
2508	tristate "Test bitmap_*() family of functions at runtime"
2509	help
2510	  Enable this option to test the bitmap functions at boot.
2511
2512	  If unsure, say N.
2513
2514config TEST_UUID
2515	tristate "Test functions located in the uuid module at runtime"
2516
2517config TEST_XARRAY
2518	tristate "Test the XArray code at runtime"
2519
2520config TEST_MAPLE_TREE
2521	tristate "Test the Maple Tree code at runtime or module load"
2522	help
2523	  Enable this option to test the maple tree code functions at boot, or
2524	  when the module is loaded. Enable "Debug Maple Trees" will enable
2525	  more verbose output on failures.
2526
2527	  If unsure, say N.
2528
2529config TEST_RHASHTABLE
2530	tristate "Perform selftest on resizable hash table"
2531	help
2532	  Enable this option to test the rhashtable functions at boot.
2533
2534	  If unsure, say N.
2535
2536config TEST_IDA
2537	tristate "Perform selftest on IDA functions"
2538
2539config TEST_MISC_MINOR
2540	bool "miscdevice KUnit test" if !KUNIT_ALL_TESTS
2541	depends on KUNIT=y
2542	default KUNIT_ALL_TESTS
2543	help
2544	  Kunit test for miscdevice API, specially its behavior in respect to
2545	  static and dynamic minor numbers.
2546
2547	  KUnit tests run during boot and output the results to the debug log
2548	  in TAP format (https://testanything.org/). Only useful for kernel devs
2549	  running the KUnit test harness, and not intended for inclusion into a
2550	  production build.
2551
2552	  For more information on KUnit and unit tests in general please refer
2553	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2554
2555	  If unsure, say N.
2556
2557config TEST_PARMAN
2558	tristate "Perform selftest on priority array manager"
2559	depends on PARMAN
2560	help
2561	  Enable this option to test priority array manager on boot
2562	  (or module load).
2563
2564	  If unsure, say N.
2565
2566config TEST_IRQ_TIMINGS
2567	bool "IRQ timings selftest"
2568	depends on IRQ_TIMINGS
2569	help
2570	  Enable this option to test the irq timings code on boot.
2571
2572	  If unsure, say N.
2573
2574config TEST_LKM
2575	tristate "Test module loading with 'hello world' module"
2576	depends on m
2577	help
2578	  This builds the "test_module" module that emits "Hello, world"
2579	  on printk when loaded. It is designed to be used for basic
2580	  evaluation of the module loading subsystem (for example when
2581	  validating module verification). It lacks any extra dependencies,
2582	  and will not normally be loaded by the system unless explicitly
2583	  requested by name.
2584
2585	  If unsure, say N.
2586
2587config TEST_BITOPS
2588	tristate "Test module for compilation of bitops operations"
2589	help
2590	  This builds the "test_bitops" module that is much like the
2591	  TEST_LKM module except that it does a basic exercise of the
2592	  set/clear_bit macros and get_count_order/long to make sure there are
2593	  no compiler warnings from C=1 sparse checker or -Wextra
2594	  compilations. It has no dependencies and doesn't run or load unless
2595	  explicitly requested by name.  for example: modprobe test_bitops.
2596
2597	  If unsure, say N.
2598
2599config TEST_VMALLOC
2600	tristate "Test module for stress/performance analysis of vmalloc allocator"
2601	default n
2602	depends on MMU
2603	help
2604	  This builds the "test_vmalloc" module that should be used for
2605	  stress and performance analysis. So, any new change for vmalloc
2606	  subsystem can be evaluated from performance and stability point
2607	  of view.
2608
2609	  If unsure, say N.
2610
2611config TEST_BPF
2612	tristate "Test BPF filter functionality"
2613	depends on m && NET
2614	help
2615	  This builds the "test_bpf" module that runs various test vectors
2616	  against the BPF interpreter or BPF JIT compiler depending on the
2617	  current setting. This is in particular useful for BPF JIT compiler
2618	  development, but also to run regression tests against changes in
2619	  the interpreter code. It also enables test stubs for eBPF maps and
2620	  verifier used by user space verifier testsuite.
2621
2622	  If unsure, say N.
2623
2624config FIND_BIT_BENCHMARK
2625	tristate "Test find_bit functions"
2626	help
2627	  This builds the "test_find_bit" module that measure find_*_bit()
2628	  functions performance.
2629
2630	  If unsure, say N.
2631
2632config FIND_BIT_BENCHMARK_RUST
2633	tristate "Test find_bit functions in Rust"
2634	depends on RUST
2635	help
2636	  This builds the "find_bit_benchmark_rust" module. It is a micro
2637          benchmark that measures the performance of Rust functions that
2638          correspond to the find_*_bit() operations in C. It follows the
2639          FIND_BIT_BENCHMARK closely but will in general not yield same
2640          numbers due to extra bounds checks and overhead of foreign
2641          function calls.
2642
2643	  If unsure, say N.
2644
2645config TEST_FIRMWARE
2646	tristate "Test firmware loading via userspace interface"
2647	depends on FW_LOADER
2648	help
2649	  This builds the "test_firmware" module that creates a userspace
2650	  interface for testing firmware loading. This can be used to
2651	  control the triggering of firmware loading without needing an
2652	  actual firmware-using device. The contents can be rechecked by
2653	  userspace.
2654
2655	  If unsure, say N.
2656
2657config TEST_SYSCTL
2658	tristate "sysctl test driver"
2659	depends on PROC_SYSCTL
2660	help
2661	  This builds the "test_sysctl" module. This driver enables to test the
2662	  proc sysctl interfaces available to drivers safely without affecting
2663	  production knobs which might alter system functionality.
2664
2665	  If unsure, say N.
2666
2667config BITFIELD_KUNIT
2668	tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2669	depends on KUNIT
2670	default KUNIT_ALL_TESTS
2671	help
2672	  Enable this option to test the bitfield functions at boot.
2673
2674	  KUnit tests run during boot and output the results to the debug log
2675	  in TAP format (http://testanything.org/). Only useful for kernel devs
2676	  running the KUnit test harness, and not intended for inclusion into a
2677	  production build.
2678
2679	  For more information on KUnit and unit tests in general please refer
2680	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2681
2682	  If unsure, say N.
2683
2684config CHECKSUM_KUNIT
2685	tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2686	depends on KUNIT
2687	default KUNIT_ALL_TESTS
2688	help
2689	  Enable this option to test the checksum functions at boot.
2690
2691	  KUnit tests run during boot and output the results to the debug log
2692	  in TAP format (http://testanything.org/). Only useful for kernel devs
2693	  running the KUnit test harness, and not intended for inclusion into a
2694	  production build.
2695
2696	  For more information on KUnit and unit tests in general please refer
2697	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2698
2699	  If unsure, say N.
2700
2701config UTIL_MACROS_KUNIT
2702	tristate "KUnit test util_macros.h functions at runtime" if !KUNIT_ALL_TESTS
2703	depends on KUNIT
2704	default KUNIT_ALL_TESTS
2705	help
2706	  Enable this option to test the util_macros.h function at boot.
2707
2708	  KUnit tests run during boot and output the results to the debug log
2709	  in TAP format (http://testanything.org/). Only useful for kernel devs
2710	  running the KUnit test harness, and not intended for inclusion into a
2711	  production build.
2712
2713	  For more information on KUnit and unit tests in general please refer
2714	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2715
2716	  If unsure, say N.
2717
2718config HASH_KUNIT_TEST
2719	tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2720	depends on KUNIT
2721	default KUNIT_ALL_TESTS
2722	help
2723	  Enable this option to test the kernel's string (<linux/stringhash.h>), and
2724	  integer (<linux/hash.h>) hash functions on boot.
2725
2726	  KUnit tests run during boot and output the results to the debug log
2727	  in TAP format (https://testanything.org/). Only useful for kernel devs
2728	  running the KUnit test harness, and not intended for inclusion into a
2729	  production build.
2730
2731	  For more information on KUnit and unit tests in general please refer
2732	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2733
2734	  This is intended to help people writing architecture-specific
2735	  optimized versions. If unsure, say N.
2736
2737config RESOURCE_KUNIT_TEST
2738	tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2739	depends on KUNIT
2740	default KUNIT_ALL_TESTS
2741	select GET_FREE_REGION
2742	help
2743	  This builds the resource API unit test.
2744	  Tests the logic of API provided by resource.c and ioport.h.
2745	  For more information on KUnit and unit tests in general please refer
2746	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2747
2748	  If unsure, say N.
2749
2750config SYSCTL_KUNIT_TEST
2751	tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2752	depends on KUNIT
2753	default KUNIT_ALL_TESTS
2754	help
2755	  This builds the proc sysctl unit test, which runs on boot.
2756	  Tests the API contract and implementation correctness of sysctl.
2757	  For more information on KUnit and unit tests in general please refer
2758	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2759
2760	  If unsure, say N.
2761
2762config KFIFO_KUNIT_TEST
2763	tristate "KUnit Test for the generic kernel FIFO implementation" if !KUNIT_ALL_TESTS
2764	depends on KUNIT
2765	default KUNIT_ALL_TESTS
2766	help
2767	  This builds the generic FIFO implementation KUnit test suite.
2768	  It tests that the API and basic functionality of the kfifo type
2769	  and associated macros.
2770
2771	  For more information on KUnit and unit tests in general please refer
2772	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2773
2774	  If unsure, say N.
2775
2776config LIST_KUNIT_TEST
2777	tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2778	depends on KUNIT
2779	default KUNIT_ALL_TESTS
2780	help
2781	  This builds the linked list KUnit test suite.
2782	  It tests that the API and basic functionality of the list_head type
2783	  and associated macros.
2784
2785	  KUnit tests run during boot and output the results to the debug log
2786	  in TAP format (https://testanything.org/). Only useful for kernel devs
2787	  running the KUnit test harness, and not intended for inclusion into a
2788	  production build.
2789
2790	  For more information on KUnit and unit tests in general please refer
2791	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2792
2793	  If unsure, say N.
2794
2795config HASHTABLE_KUNIT_TEST
2796	tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2797	depends on KUNIT
2798	default KUNIT_ALL_TESTS
2799	help
2800	  This builds the hashtable KUnit test suite.
2801	  It tests the basic functionality of the API defined in
2802	  include/linux/hashtable.h. For more information on KUnit and
2803	  unit tests in general please refer to the KUnit documentation
2804	  in Documentation/dev-tools/kunit/.
2805
2806	  If unsure, say N.
2807
2808config LINEAR_RANGES_TEST
2809	tristate "KUnit test for linear_ranges"
2810	depends on KUNIT
2811	select LINEAR_RANGES
2812	help
2813	  This builds the linear_ranges unit test, which runs on boot.
2814	  Tests the linear_ranges logic correctness.
2815	  For more information on KUnit and unit tests in general please refer
2816	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2817
2818	  If unsure, say N.
2819
2820config CMDLINE_KUNIT_TEST
2821	tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2822	depends on KUNIT
2823	default KUNIT_ALL_TESTS
2824	help
2825	  This builds the cmdline API unit test.
2826	  Tests the logic of API provided by cmdline.c.
2827	  For more information on KUnit and unit tests in general please refer
2828	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2829
2830	  If unsure, say N.
2831
2832config BASE64_KUNIT
2833	tristate "KUnit test for base64 decoding and encoding" if !KUNIT_ALL_TESTS
2834	depends on KUNIT
2835	default KUNIT_ALL_TESTS
2836	help
2837	  This builds the base64 unit tests.
2838
2839	  The tests cover the encoding and decoding logic of Base64 functions
2840	  in the kernel.
2841	  In addition to correctness checks, simple performance benchmarks
2842	  for both encoding and decoding are also included.
2843
2844	  For more information on KUnit and unit tests in general please refer
2845	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2846
2847	  If unsure, say N.
2848
2849config BITS_TEST
2850	tristate "KUnit test for bit functions and macros" if !KUNIT_ALL_TESTS
2851	depends on KUNIT
2852	default KUNIT_ALL_TESTS
2853	help
2854	  This builds the bits unit test.
2855	  Tests the logic of macros defined in bits.h.
2856	  For more information on KUnit and unit tests in general please refer
2857	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2858
2859	  If unsure, say N.
2860
2861config SLUB_KUNIT_TEST
2862	tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2863	depends on SLUB_DEBUG && KUNIT
2864	default KUNIT_ALL_TESTS
2865	help
2866	  This builds SLUB allocator unit test.
2867	  Tests SLUB cache debugging functionality.
2868	  For more information on KUnit and unit tests in general please refer
2869	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2870
2871	  If unsure, say N.
2872
2873config RATIONAL_KUNIT_TEST
2874	tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2875	depends on KUNIT && RATIONAL
2876	default KUNIT_ALL_TESTS
2877	help
2878	  This builds the rational math unit test.
2879	  For more information on KUnit and unit tests in general please refer
2880	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2881
2882	  If unsure, say N.
2883
2884config MEMCPY_KUNIT_TEST
2885	tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2886	depends on KUNIT
2887	default KUNIT_ALL_TESTS
2888	help
2889	  Builds unit tests for memcpy(), memmove(), and memset() functions.
2890	  For more information on KUnit and unit tests in general please refer
2891	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2892
2893	  If unsure, say N.
2894
2895config IS_SIGNED_TYPE_KUNIT_TEST
2896	tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2897	depends on KUNIT
2898	default KUNIT_ALL_TESTS
2899	help
2900	  Builds unit tests for the is_signed_type() macro.
2901
2902	  For more information on KUnit and unit tests in general please refer
2903	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2904
2905	  If unsure, say N.
2906
2907config OVERFLOW_KUNIT_TEST
2908	tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2909	depends on KUNIT
2910	default KUNIT_ALL_TESTS
2911	help
2912	  Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2913	  related functions.
2914
2915	  For more information on KUnit and unit tests in general please refer
2916	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2917
2918	  If unsure, say N.
2919
2920config RANDSTRUCT_KUNIT_TEST
2921	tristate "Test randstruct structure layout randomization at runtime" if !KUNIT_ALL_TESTS
2922	depends on KUNIT
2923	default KUNIT_ALL_TESTS
2924	help
2925	  Builds unit tests for the checking CONFIG_RANDSTRUCT=y, which
2926	  randomizes structure layouts.
2927
2928config STACKINIT_KUNIT_TEST
2929	tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2930	depends on KUNIT
2931	default KUNIT_ALL_TESTS
2932	help
2933	  Test if the kernel is zero-initializing stack variables and
2934	  padding. Coverage is controlled by compiler flags,
2935	  CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_ALL_ZERO.
2936
2937config FORTIFY_KUNIT_TEST
2938	tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2939	depends on KUNIT
2940	default KUNIT_ALL_TESTS
2941	help
2942	  Builds unit tests for checking internals of FORTIFY_SOURCE as used
2943	  by the str*() and mem*() family of functions. For testing runtime
2944	  traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2945
2946config LONGEST_SYM_KUNIT_TEST
2947	tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS
2948	depends on KUNIT && KPROBES
2949	depends on !PREFIX_SYMBOLS && !CFI && !GCOV_KERNEL
2950	default KUNIT_ALL_TESTS
2951	help
2952	  Tests the longest symbol possible
2953
2954	  If unsure, say N.
2955
2956config HW_BREAKPOINT_KUNIT_TEST
2957	bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2958	depends on HAVE_HW_BREAKPOINT
2959	depends on KUNIT=y
2960	default KUNIT_ALL_TESTS
2961	help
2962	  Tests for hw_breakpoint constraints accounting.
2963
2964	  If unsure, say N.
2965
2966config SIPHASH_KUNIT_TEST
2967	tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2968	depends on KUNIT
2969	default KUNIT_ALL_TESTS
2970	help
2971	  Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2972	  functions on boot (or module load).
2973
2974	  This is intended to help people writing architecture-specific
2975	  optimized versions.  If unsure, say N.
2976
2977config USERCOPY_KUNIT_TEST
2978	tristate "KUnit Test for user/kernel boundary protections"
2979	depends on KUNIT
2980	default KUNIT_ALL_TESTS
2981	help
2982	  This builds the "usercopy_kunit" module that runs sanity checks
2983	  on the copy_to/from_user infrastructure, making sure basic
2984	  user/kernel boundary testing is working.
2985
2986config BLACKHOLE_DEV_KUNIT_TEST
2987	tristate "Test blackhole netdev functionality" if !KUNIT_ALL_TESTS
2988	depends on NET
2989	depends on KUNIT
2990	default KUNIT_ALL_TESTS
2991	help
2992	  This builds the "blackhole_dev_kunit" module that validates the
2993	  data path through this blackhole netdev.
2994
2995	  If unsure, say N.
2996
2997config TEST_UDELAY
2998	tristate "udelay test driver"
2999	help
3000	  This builds the "udelay_test" module that helps to make sure
3001	  that udelay() is working properly.
3002
3003	  If unsure, say N.
3004
3005config TEST_STATIC_KEYS
3006	tristate "Test static keys"
3007	depends on m
3008	help
3009	  Test the static key interfaces.
3010
3011	  If unsure, say N.
3012
3013config TEST_DYNAMIC_DEBUG
3014	tristate "Test DYNAMIC_DEBUG"
3015	depends on DYNAMIC_DEBUG
3016	help
3017	  This module registers a tracer callback to count enabled
3018	  pr_debugs in a 'do_debugging' function, then alters their
3019	  enablements, calls the function, and compares counts.
3020
3021	  If unsure, say N.
3022
3023config TEST_KMOD
3024	tristate "kmod stress tester"
3025	depends on m
3026	select TEST_LKM
3027	help
3028	  Test the kernel's module loading mechanism: kmod. kmod implements
3029	  support to load modules using the Linux kernel's usermode helper.
3030	  This test provides a series of tests against kmod.
3031
3032	  Although technically you can either build test_kmod as a module or
3033	  into the kernel we disallow building it into the kernel since
3034	  it stress tests request_module() and this will very likely cause
3035	  some issues by taking over precious threads available from other
3036	  module load requests, ultimately this could be fatal.
3037
3038	  To run tests run:
3039
3040	  tools/testing/selftests/kmod/kmod.sh --help
3041
3042	  If unsure, say N.
3043
3044config TEST_RUNTIME
3045	bool
3046
3047config TEST_RUNTIME_MODULE
3048	bool
3049
3050config TEST_KALLSYMS
3051	tristate "module kallsyms find_symbol() test"
3052	depends on m
3053	select TEST_RUNTIME
3054	select TEST_RUNTIME_MODULE
3055	select TEST_KALLSYMS_A
3056	select TEST_KALLSYMS_B
3057	select TEST_KALLSYMS_C
3058	select TEST_KALLSYMS_D
3059	help
3060	  This allows us to stress test find_symbol() through the kallsyms
3061	  used to place symbols on the kernel ELF kallsyms and modules kallsyms
3062	  where we place kernel symbols such as exported symbols.
3063
3064	  We have four test modules:
3065
3066	  A: has KALLSYSMS_NUMSYMS exported symbols
3067	  B: uses one of A's symbols
3068	  C: adds KALLSYMS_SCALE_FACTOR * KALLSYSMS_NUMSYMS exported
3069	  D: adds 2 * the symbols than C
3070
3071	  We stress test find_symbol() through two means:
3072
3073	  1) Upon load of B it will trigger simplify_symbols() to look for the
3074	  one symbol it uses from the module A with tons of symbols. This is an
3075	  indirect way for us to have B call resolve_symbol_wait() upon module
3076	  load. This will eventually call find_symbol() which will eventually
3077	  try to find the symbols used with find_exported_symbol_in_section().
3078	  find_exported_symbol_in_section() uses bsearch() so a binary search
3079	  for each symbol. Binary search will at worst be O(log(n)) so the
3080	  larger TEST_MODULE_KALLSYSMS the worse the search.
3081
3082	  2) The selftests should load C first, before B. Upon B's load towards
3083	  the end right before we call module B's init routine we get
3084	  complete_formation() called on the module. That will first check
3085	  for duplicate symbols with the call to verify_exported_symbols().
3086	  That is when we'll force iteration on module C's insane symbol list.
3087	  Since it has 10 * KALLSYMS_NUMSYMS it means we can first test
3088	  just loading B without C. The amount of time it takes to load C Vs
3089	  B can give us an idea of the impact growth of the symbol space and
3090	  give us projection. Module A only uses one symbol from B so to allow
3091	  this scaling in module C to be proportional, if it used more symbols
3092	  then the first test would be doing more and increasing just the
3093	  search space would be slightly different. The last module, module D
3094	  will just increase the search space by twice the number of symbols in
3095	  C so to allow for full projects.
3096
3097	  tools/testing/selftests/module/find_symbol.sh
3098
3099	  The current defaults will incur a build delay of about 7 minutes
3100	  on an x86_64 with only 8 cores. Enable this only if you want to
3101	  stress test find_symbol() with thousands of symbols. At the same
3102	  time this is also useful to test building modules with thousands of
3103	  symbols, and if BTF is enabled this also stress tests adding BTF
3104	  information for each module. Currently enabling many more symbols
3105	  will segfault the build system.
3106
3107	  If unsure, say N.
3108
3109if TEST_KALLSYMS
3110
3111config TEST_KALLSYMS_A
3112	tristate
3113	depends on m
3114
3115config TEST_KALLSYMS_B
3116	tristate
3117	depends on m
3118
3119config TEST_KALLSYMS_C
3120	tristate
3121	depends on m
3122
3123config TEST_KALLSYMS_D
3124	tristate
3125	depends on m
3126
3127choice
3128	prompt "Kallsym test range"
3129	default TEST_KALLSYMS_LARGE
3130	help
3131	  Selecting something other than "Fast" will enable tests which slow
3132	  down the build and may crash your build.
3133
3134config TEST_KALLSYMS_FAST
3135	bool "Fast builds"
3136	help
3137	  You won't really be testing kallsysms, so this just helps fast builds
3138	  when allmodconfig is used..
3139
3140config TEST_KALLSYMS_LARGE
3141	bool "Enable testing kallsyms with large exports"
3142	help
3143	  This will enable larger number of symbols. This will slow down
3144	  your build considerably.
3145
3146config TEST_KALLSYMS_MAX
3147	bool "Known kallsysms limits"
3148	help
3149	  This will enable exports to the point we know we'll start crashing
3150	  builds.
3151
3152endchoice
3153
3154config TEST_KALLSYMS_NUMSYMS
3155	int "test kallsyms number of symbols"
3156	range 2 10000
3157	default 2 if TEST_KALLSYMS_FAST
3158	default 100 if TEST_KALLSYMS_LARGE
3159	default 10000 if TEST_KALLSYMS_MAX
3160	help
3161	  The number of symbols to create on TEST_KALLSYMS_A, only one of which
3162	  module TEST_KALLSYMS_B will use. This also will be used
3163	  for how many symbols TEST_KALLSYMS_C will have, scaled up by
3164	  TEST_KALLSYMS_SCALE_FACTOR. Note that setting this to 10,000 will
3165	  trigger a segfault today, don't use anything close to it unless
3166	  you are aware that this should not be used for automated build tests.
3167
3168config TEST_KALLSYMS_SCALE_FACTOR
3169	int "test kallsyms scale factor"
3170	default 8
3171	help
3172	  How many more unusued symbols will TEST_KALLSYSMS_C have than
3173	  TEST_KALLSYMS_A. If 8, then module C will have 8 * syms
3174	  than module A. Then TEST_KALLSYMS_D will have double the amount
3175	  of symbols than C so to allow projections.
3176
3177endif # TEST_KALLSYMS
3178
3179config TEST_DEBUG_VIRTUAL
3180	tristate "Test CONFIG_DEBUG_VIRTUAL feature"
3181	depends on DEBUG_VIRTUAL
3182	help
3183	  Test the kernel's ability to detect incorrect calls to
3184	  virt_to_phys() done against the non-linear part of the
3185	  kernel's virtual address map.
3186
3187	  If unsure, say N.
3188
3189config TEST_MEMCAT_P
3190	tristate "Test memcat_p() helper function"
3191	help
3192	  Test the memcat_p() helper for correctly merging two
3193	  pointer arrays together.
3194
3195	  If unsure, say N.
3196
3197config TEST_OBJAGG
3198	tristate "Perform selftest on object aggreration manager"
3199	default n
3200	depends on OBJAGG
3201	help
3202	  Enable this option to test object aggregation manager on boot
3203	  (or module load).
3204
3205config TEST_MEMINIT
3206	tristate "Test heap/page initialization"
3207	help
3208	  Test if the kernel is zero-initializing heap and page allocations.
3209	  This can be useful to test init_on_alloc and init_on_free features.
3210
3211	  If unsure, say N.
3212
3213config TEST_HMM
3214	tristate "Test HMM (Heterogeneous Memory Management)"
3215	depends on TRANSPARENT_HUGEPAGE
3216	depends on DEVICE_PRIVATE
3217	select HMM_MIRROR
3218	select MMU_NOTIFIER
3219	help
3220	  This is a pseudo device driver solely for testing HMM.
3221	  Say M here if you want to build the HMM test module.
3222	  Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
3223
3224	  If unsure, say N.
3225
3226config TEST_FREE_PAGES
3227	tristate "Test freeing pages"
3228	help
3229	  Test that a memory leak does not occur due to a race between
3230	  freeing a block of pages and a speculative page reference.
3231	  Loading this module is safe if your kernel has the bug fixed.
3232	  If the bug is not fixed, it will leak gigabytes of memory and
3233	  probably OOM your system.
3234
3235config TEST_FPU
3236	tristate "Test floating point operations in kernel space"
3237	depends on ARCH_HAS_KERNEL_FPU_SUPPORT && !KCOV_INSTRUMENT_ALL
3238	help
3239	  Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
3240	  which will trigger a sequence of floating point operations. This is used
3241	  for self-testing floating point control register setting in
3242	  kernel_fpu_begin().
3243
3244	  If unsure, say N.
3245
3246config TEST_CLOCKSOURCE_WATCHDOG
3247	tristate "Test clocksource watchdog in kernel space"
3248	depends on CLOCKSOURCE_WATCHDOG
3249	help
3250	  Enable this option to create a kernel module that will trigger
3251	  a test of the clocksource watchdog.  This module may be loaded
3252	  via modprobe or insmod in which case it will run upon being
3253	  loaded, or it may be built in, in which case it will run
3254	  shortly after boot.
3255
3256	  If unsure, say N.
3257
3258config TEST_OBJPOOL
3259	tristate "Test module for correctness and stress of objpool"
3260	default n
3261	depends on m && DEBUG_KERNEL
3262	help
3263	  This builds the "test_objpool" module that should be used for
3264	  correctness verification and concurrent testings of objects
3265	  allocation and reclamation.
3266
3267	  If unsure, say N.
3268
3269config TEST_KEXEC_HANDOVER
3270	bool "Test for Kexec HandOver"
3271	default n
3272	depends on KEXEC_HANDOVER
3273	help
3274	  This option enables test for Kexec HandOver (KHO).
3275	  The test consists of two parts: saving kernel data before kexec and
3276	  restoring the data after kexec and verifying that it was properly
3277	  handed over. This test module creates and saves data on the boot of
3278	  the first kernel and restores and verifies the data on the boot of
3279	  kexec'ed kernel.
3280
3281	  For detailed documentation about KHO, see Documentation/core-api/kho.
3282
3283	  To run the test run:
3284
3285	  tools/testing/selftests/kho/vmtest.sh -h
3286
3287	  If unsure, say N.
3288
3289config RATELIMIT_KUNIT_TEST
3290	tristate "KUnit Test for correctness and stress of ratelimit" if !KUNIT_ALL_TESTS
3291	depends on KUNIT
3292	default KUNIT_ALL_TESTS
3293	help
3294	  This builds the "test_ratelimit" module that should be used
3295	  for correctness verification and concurrent testings of rate
3296	  limiting.
3297
3298	  If unsure, say N.
3299
3300config INT_POW_KUNIT_TEST
3301	tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS
3302	depends on KUNIT
3303	default KUNIT_ALL_TESTS
3304	help
3305	  This option enables the KUnit test suite for the int_pow function,
3306	  which performs integer exponentiation. The test suite is designed to
3307	  verify that the implementation of int_pow correctly computes the power
3308	  of a given base raised to a given exponent.
3309
3310	  Enabling this option will include tests that check various scenarios
3311	  and edge cases to ensure the accuracy and reliability of the exponentiation
3312	  function.
3313
3314	  If unsure, say N
3315
3316config INT_SQRT_KUNIT_TEST
3317	tristate "Integer square root test" if !KUNIT_ALL_TESTS
3318	depends on KUNIT
3319	default KUNIT_ALL_TESTS
3320	help
3321	  This option enables the KUnit test suite for the int_sqrt() function,
3322	  which performs square root calculation. The test suite checks
3323	  various scenarios, including edge cases, to ensure correctness.
3324
3325	  Enabling this option will include tests that check various scenarios
3326	  and edge cases to ensure the accuracy and reliability of the square root
3327	  function.
3328
3329	  If unsure, say N
3330
3331config INT_LOG_KUNIT_TEST
3332        tristate "Integer log (int_log) test" if !KUNIT_ALL_TESTS
3333        depends on KUNIT
3334        default KUNIT_ALL_TESTS
3335        help
3336          This option enables the KUnit test suite for the int_log library, which
3337          provides two functions to compute the integer logarithm in base 2 and
3338          base 10, called respectively as intlog2 and intlog10.
3339
3340          If unsure, say N
3341
3342config GCD_KUNIT_TEST
3343	tristate "Greatest common divisor test" if !KUNIT_ALL_TESTS
3344	depends on KUNIT
3345	default KUNIT_ALL_TESTS
3346	help
3347	  This option enables the KUnit test suite for the gcd() function,
3348	  which computes the greatest common divisor of two numbers.
3349
3350	  This test suite verifies the correctness of gcd() across various
3351	  scenarios, including edge cases.
3352
3353	  If unsure, say N
3354
3355config PRIME_NUMBERS_KUNIT_TEST
3356	tristate "Prime number generator test" if !KUNIT_ALL_TESTS
3357	depends on KUNIT
3358	depends on PRIME_NUMBERS
3359	default KUNIT_ALL_TESTS
3360	help
3361	  This option enables the KUnit test suite for the {is,next}_prime_number
3362	  functions.
3363
3364	  Enabling this option will include tests that compare the prime number
3365	  generator functions against a brute force implementation.
3366
3367	  If unsure, say N
3368
3369endif # RUNTIME_TESTING_MENU
3370
3371config ARCH_USE_MEMTEST
3372	bool
3373	help
3374	  An architecture should select this when it uses early_memtest()
3375	  during boot process.
3376
3377config MEMTEST
3378	bool "Memtest"
3379	depends on ARCH_USE_MEMTEST
3380	help
3381	  This option adds a kernel parameter 'memtest', which allows memtest
3382	  to be set and executed.
3383	        memtest=0, mean disabled; -- default
3384	        memtest=1, mean do 1 test pattern;
3385	        ...
3386	        memtest=17, mean do 17 test patterns.
3387	  If you are unsure how to answer this question, answer N.
3388
3389
3390
3391config HYPERV_TESTING
3392	bool "Microsoft Hyper-V driver testing"
3393	default n
3394	depends on HYPERV && DEBUG_FS
3395	help
3396	  Select this option to enable Hyper-V vmbus testing.
3397
3398endmenu # "Kernel Testing and Coverage"
3399
3400menu "Rust hacking"
3401
3402config RUST_DEBUG_ASSERTIONS
3403	bool "Debug assertions"
3404	depends on RUST
3405	help
3406	  Enables rustc's `-Cdebug-assertions` codegen option.
3407
3408	  This flag lets you turn `cfg(debug_assertions)` conditional
3409	  compilation on or off. This can be used to enable extra debugging
3410	  code in development but not in production. For example, it controls
3411	  the behavior of the standard library's `debug_assert!` macro.
3412
3413	  Note that this will apply to all Rust code, including `core`.
3414
3415	  If unsure, say N.
3416
3417config RUST_OVERFLOW_CHECKS
3418	bool "Overflow checks"
3419	default y
3420	depends on RUST
3421	help
3422	  Enables rustc's `-Coverflow-checks` codegen option.
3423
3424	  This flag allows you to control the behavior of runtime integer
3425	  overflow. When overflow-checks are enabled, a Rust panic will occur
3426	  on overflow.
3427
3428	  Note that this will apply to all Rust code, including `core`.
3429
3430	  If unsure, say Y.
3431
3432config RUST_BUILD_ASSERT_ALLOW
3433	bool "Allow unoptimized build-time assertions"
3434	depends on RUST
3435	help
3436	  Controls how `build_error!` and `build_assert!` are handled during the build.
3437
3438	  If calls to them exist in the binary, it may indicate a violated invariant
3439	  or that the optimizer failed to verify the invariant during compilation.
3440
3441	  This should not happen, thus by default the build is aborted. However,
3442	  as an escape hatch, you can choose Y here to ignore them during build
3443	  and let the check be carried at runtime (with `panic!` being called if
3444	  the check fails).
3445
3446	  If unsure, say N.
3447
3448config RUST_KERNEL_DOCTESTS
3449	bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3450	depends on RUST && KUNIT=y
3451	default KUNIT_ALL_TESTS
3452	help
3453	  This builds the documentation tests of the `kernel` crate
3454	  as KUnit tests.
3455
3456	  For more information on KUnit and unit tests in general,
3457	  please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3458
3459	  If unsure, say N.
3460
3461endmenu # "Rust"
3462
3463endmenu # Kernel hacking
3464