mm/swapfile: add cond_resched() in get_swap_pages()
[linux-block.git] / lib / Kconfig.debug
CommitLineData
ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
06ec64b8
CH
2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
1da177e4
LT
5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
649e6ee3
KS
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
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
15ff2069
TH
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
22f4e66d
SB
38config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
40 depends on PRINTK
41 help
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
44
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
48
a8cfdc68
OJ
49config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
51 range 1 15
52 default "7"
53 help
54 Default loglevel to determine what will be printed on the console.
55
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
59
50f4d9bd 60 Note: This does not affect the log level of un-prefixed printk()
a8cfdc68
OJ
61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option.
63
22eceb8b
HG
64config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
66 range 1 15
67 default "4"
68 help
69 loglevel to use when "quiet" is passed on the kernel commandline.
70
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74
42a9dc0b 75config MESSAGE_LOGLEVEL_DEFAULT
5af5bcb8
MSB
76 int "Default message log level (1-7)"
77 range 1 7
78 default "4"
79 help
80 Default log level for printk statements with no specified priority.
81
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
84 priority.
85
a8cfdc68
OJ
86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89
604ff0dc
DH
90config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
97 using "boot_delay=N".
98
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
107
108config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support"
110 default n
111 depends on PRINTK
239a5791 112 depends on (DEBUG_FS || PROC_FS)
ceabef7d 113 select DYNAMIC_DEBUG_CORE
604ff0dc
DH
114 help
115
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
122
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
127
128 Usage:
129
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
239a5791
GKH
131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
604ff0dc
DH
134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
137
138 filename:lineno [module]function flags format
139
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
68d4b3df
KK
144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
604ff0dc
DH
146
147 From a live system:
148
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154
155 Example usage:
156
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
160
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
164
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
168
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
172
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
176
f8998c22
HH
177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information.
604ff0dc 179
ceabef7d
OZ
180config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
182 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS)
184 help
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
190
57f5677e
RV
191config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
193 default y if PRINTK
194 help
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
199
2b05bb75
CD
200config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y
204 help
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
208
604ff0dc
DH
209endmenu # "printk and dmesg options"
210
f9b3cd24
KC
211config DEBUG_KERNEL
212 bool "Kernel debugging"
213 help
214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems.
216
217config DEBUG_MISC
218 bool "Miscellaneous debug code"
219 default DEBUG_KERNEL
220 depends on DEBUG_KERNEL
221 help
222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug option but isn't.
224
6dfc0665
DH
225menu "Compile-time checks and compiler options"
226
227config DEBUG_INFO
f9b3cd24 228 bool
6dfc0665 229 help
f9b3cd24
KC
230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice below, indicating that debug
232 information will be generated for build targets.
233
0a6de78c
NC
234# Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
235# some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
236config AS_HAS_NON_CONST_LEB128
237 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
238
f9b3cd24
KC
239choice
240 prompt "Debug information"
241 depends on DEBUG_KERNEL
242 help
243 Selecting something other than "None" results in a kernel image
244 that will include debugging info resulting in a larger kernel image.
6dfc0665
DH
245 This adds debug symbols to the kernel and modules (gcc -g), and
246 is needed if you intend to use kernel crashdump or binary object
247 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
6dfc0665 248
f9b3cd24
KC
249 Choose which version of DWARF debug info to emit. If unsure,
250 select "Toolchain default".
251
252config DEBUG_INFO_NONE
253 bool "Disable debug information"
254 help
255 Do not build the kernel with debugging information, which will
256 result in a faster and smaller build.
257
258config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
259 bool "Rely on the toolchain's implicit default DWARF version"
260 select DEBUG_INFO
0a6de78c 261 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
f9b3cd24
KC
262 help
263 The implicit default version of DWARF debug info produced by a
264 toolchain changes over time.
265
266 This can break consumers of the debug info that haven't upgraded to
267 support newer revisions, and prevent testing newer versions, but
268 those should be less common scenarios.
269
270config DEBUG_INFO_DWARF4
271 bool "Generate DWARF Version 4 debuginfo"
272 select DEBUG_INFO
4f001a21 273 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
f9b3cd24 274 help
32ef9e50
ND
275 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
276 if using clang without clang's integrated assembler, and gdb 7.0+.
f9b3cd24
KC
277
278 If you have consumers of DWARF debug info that are not ready for
279 newer revisions of DWARF, you may wish to choose this or have your
280 config select this.
281
282config DEBUG_INFO_DWARF5
283 bool "Generate DWARF Version 5 debuginfo"
284 select DEBUG_INFO
0a6de78c 285 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
f9b3cd24
KC
286 help
287 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
288 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
289 draft features until 7.0), and gdb 8.0+.
290
291 Changes to the structure of debug info in Version 5 allow for around
292 15-18% savings in resulting image and debug info section sizes as
293 compared to DWARF Version 4. DWARF Version 5 standardizes previous
294 extensions such as accelerators for symbol indexing and the format
295 for fission (.dwo/.dwp) files. Users may not want to select this
296 config if they rely on tooling that has not yet been updated to
297 support DWARF Version 5.
298
299endchoice # "Debug information"
6dfc0665 300
695afd3d
SD
301if DEBUG_INFO
302
6dfc0665
DH
303config DEBUG_INFO_REDUCED
304 bool "Reduce debugging information"
6dfc0665
DH
305 help
306 If you say Y here gcc is instructed to generate less debugging
307 information for structure types. This means that tools that
308 need full debugging information (like kgdb or systemtap) won't
309 be happy. But if you merely need debugging information to
310 resolve line numbers there is no loss. Advantage is that
311 build directory object sizes shrink dramatically over a full
312 DEBUG_INFO build and compile times are reduced too.
313 Only works with newer gcc versions.
314
9f8fe647
ND
315choice
316 prompt "Compressed Debug information"
317 help
318 Compress the resulting debug info. Results in smaller debug info sections,
319 but requires that consumers are able to decompress the results.
320
321 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
322
323config DEBUG_INFO_COMPRESSED_NONE
324 bool "Don't compress debug information"
325 help
326 Don't compress debug info sections.
327
328config DEBUG_INFO_COMPRESSED_ZLIB
329 bool "Compress debugging information with zlib"
10e68b02 330 depends on $(cc-option,-gz=zlib)
10e68b02
ND
331 depends on $(ld-option,--compress-debug-sections=zlib)
332 help
333 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
334 5.0+, binutils 2.26+, and zlib.
335
336 Users of dpkg-deb via scripts/package/builddeb may find an increase in
337 size of their debug .deb packages with this config set, due to the
338 debug info being compressed with zlib, then the object files being
339 recompressed with a different compression scheme. But this is still
340 preferable to setting $KDEB_COMPRESS to "none" which would be even
341 larger.
342
9f8fe647
ND
343config DEBUG_INFO_COMPRESSED_ZSTD
344 bool "Compress debugging information with zstd"
345 depends on $(cc-option,-gz=zstd)
346 depends on $(ld-option,--compress-debug-sections=zstd)
347 help
348 Compress the debug information using zstd. This may provide better
349 compression than zlib, for about the same time costs, but requires newer
350 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
351 zstd.
352
353endchoice # "Compressed Debug information"
354
866ced95
AK
355config DEBUG_INFO_SPLIT
356 bool "Produce split debuginfo in .dwo files"
9d937444 357 depends on $(cc-option,-gsplit-dwarf)
866ced95
AK
358 help
359 Generate debug info into separate .dwo files. This significantly
360 reduces the build directory size for builds with DEBUG_INFO,
361 because it stores the information only once on disk in .dwo
362 files instead of multiple times in object files and executables.
363 In addition the debug information is also compressed.
364
365 Requires recent gcc (4.7+) and recent gdb/binutils.
366 Any tool that packages or reads debug information would need
367 to know about the .dwo files and include them.
368 Incompatible with older versions of ccache.
369
e83b9f55
AN
370config DEBUG_INFO_BTF
371 bool "Generate BTF typeinfo"
7d32e693
SB
372 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
373 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
d9847eb8 374 depends on BPF_SYSCALL
52deda95 375 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
e83b9f55
AN
376 help
377 Generate deduplicated BTF type information from DWARF debug info.
378 Turning this on expects presence of pahole tool, which will convert
379 DWARF type info into equivalent deduplicated BTF type info.
380
5f9ae91f 381config PAHOLE_HAS_SPLIT_BTF
6323c813 382 def_bool PAHOLE_VERSION >= 119
5f9ae91f 383
7472d5a6 384config PAHOLE_HAS_BTF_TAG
6323c813 385 def_bool PAHOLE_VERSION >= 123
7472d5a6
YS
386 depends on CC_IS_CLANG
387 help
388 Decide whether pahole emits btf_tag attributes (btf_type_tag and
389 btf_decl_tag) or not. Currently only clang compiler implements
390 these attributes, so make the config depend on CC_IS_CLANG.
5f9ae91f
AN
391
392config DEBUG_INFO_BTF_MODULES
393 def_bool y
394 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
395 help
396 Generate compact split BTF type information for kernel modules.
397
5e214f2e
CB
398config MODULE_ALLOW_BTF_MISMATCH
399 bool "Allow loading modules with non-matching BTF type info"
400 depends on DEBUG_INFO_BTF_MODULES
401 help
402 For modules whose split BTF does not match vmlinux, load without
403 BTF rather than refusing to load. The default behavior with
404 module BTF enabled is to reject modules with such mismatches;
405 this option will still load module BTF where possible but ignore
406 it when a mismatch is found.
407
3ee7b3fa
JK
408config GDB_SCRIPTS
409 bool "Provide GDB scripts for kernel debugging"
3ee7b3fa
JK
410 help
411 This creates the required links to GDB helper scripts in the
412 build directory. If you load vmlinux into gdb, the helper
413 scripts will be automatically imported by gdb as well, and
414 additional functions are available to analyze a Linux kernel
700199b0
AP
415 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
416 for further details.
3ee7b3fa 417
695afd3d
SD
418endif # DEBUG_INFO
419
35bb5b1e 420config FRAME_WARN
a83e4ca2 421 int "Warn for stack frames larger than"
35bb5b1e 422 range 0 8192
ac66998d 423 default 0 if KMSAN
0e07f663 424 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
8d192bec
HD
425 default 2048 if PARISC
426 default 1536 if (!64BIT && XTENSA)
152fe65f 427 default 1280 if KASAN && !64BIT
8d192bec 428 default 1024 if !64BIT
35bb5b1e
AK
429 default 2048 if 64BIT
430 help
921757bc 431 Tell the compiler to warn at build time for stack frames larger than this.
35bb5b1e
AK
432 Setting this too low will cause a lot of warnings.
433 Setting it to 0 disables the warning.
35bb5b1e 434
99657c78
RD
435config STRIP_ASM_SYMS
436 bool "Strip assembler-generated symbols during link"
437 default n
438 help
439 Strip internal assembler-generated symbols during a link (symbols
440 that look like '.Lxxx') so they don't pollute the output of
441 get_wchan() and suchlike.
442
1873e870 443config READABLE_ASM
68d4b3df
KK
444 bool "Generate readable assembler code"
445 depends on DEBUG_KERNEL
7d73c3e9 446 depends on CC_IS_GCC
bf4735a4 447 help
68d4b3df
KK
448 Disable some compiler optimizations that tend to generate human unreadable
449 assembler output. This may make the kernel slightly slower, but it helps
450 to keep kernel developers who have to stare a lot at assembler listings
451 sane.
bf4735a4 452
e949f4c2
MY
453config HEADERS_INSTALL
454 bool "Install uapi headers to usr/include"
bf4735a4
DM
455 depends on !UML
456 help
e949f4c2
MY
457 This option will install uapi headers (headers exported to user-space)
458 into the usr/include directory for use during the kernel build.
459 This is unneeded for building the kernel itself, but needed for some
460 user-space program samples. It is also needed by some features such
461 as uapi header sanity checks.
462
91341d4b
SR
463config DEBUG_SECTION_MISMATCH
464 bool "Enable full Section mismatch analysis"
7d73c3e9 465 depends on CC_IS_GCC
91341d4b
SR
466 help
467 The section mismatch analysis checks if there are illegal
468 references from one section to another section.
e809ab01
MW
469 During linktime or runtime, some sections are dropped;
470 any use of code/data previously in these sections would
91341d4b 471 most likely result in an oops.
e809ab01 472 In the code, functions and variables are annotated with
0db0628d 473 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 474 which results in the code/data being placed in specific sections.
e809ab01
MW
475 The section mismatch analysis is always performed after a full
476 kernel build, and enabling this option causes the following
b7dca6dd 477 additional step to occur:
e809ab01
MW
478 - Add the option -fno-inline-functions-called-once to gcc commands.
479 When inlining a function annotated with __init in a non-init
480 function, we would lose the section information and thus
91341d4b 481 the analysis would not catch the illegal reference.
e809ab01
MW
482 This option tells gcc to inline less (but it does result in
483 a larger kernel).
91341d4b 484
47490ec1
NB
485config SECTION_MISMATCH_WARN_ONLY
486 bool "Make section mismatch errors non-fatal"
487 default y
488 help
489 If you say N here, the build process will fail if there are any
490 section mismatch, instead of just throwing warnings.
491
492 If unsure, say Y.
493
cf536e18 494config DEBUG_FORCE_FUNCTION_ALIGN_64B
1bf18da6
FT
495 bool "Force all function address 64B aligned"
496 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
d49a0626 497 select FUNCTION_ALIGNMENT_64B
09c60546
FT
498 help
499 There are cases that a commit from one domain changes the function
500 address alignment of other domains, and cause magic performance
501 bump (regression or improvement). Enable this option will help to
502 verify if the bump is caused by function alignment changes, while
503 it will slightly increase the kernel size and affect icache usage.
504
505 It is mainly for debug and performance tuning use.
506
6dfc0665
DH
507#
508# Select this config option from the architecture Kconfig, if it
509# is preferred to always offer frame pointers as a config
510# option on the architecture (regardless of KERNEL_DEBUG):
511#
512config ARCH_WANT_FRAME_POINTERS
513 bool
f346f4b3 514
6dfc0665
DH
515config FRAME_POINTER
516 bool "Compile the kernel with frame pointers"
a687a533 517 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 518 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 519 help
6dfc0665
DH
520 If you say Y here the resulting kernel image will be slightly
521 larger and slower, but it gives very useful debugging information
522 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 523
03f16cd0
JP
524config OBJTOOL
525 bool
526
b9ab5ebb
JP
527config STACK_VALIDATION
528 bool "Compile-time stack metadata validation"
03f16cd0
JP
529 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
530 select OBJTOOL
b9ab5ebb
JP
531 default n
532 help
03f16cd0
JP
533 Validate frame pointer rules at compile-time. This helps ensure that
534 runtime stack traces are more reliable.
ee9f8fce 535
b9ab5ebb 536 For more information, see
d6a21f2d 537 tools/objtool/Documentation/objtool.txt.
b9ab5ebb 538
0f620cef 539config NOINSTR_VALIDATION
6804c1af 540 bool
489e355b 541 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
03f16cd0 542 select OBJTOOL
6804c1af
PZ
543 default y
544
5cc12472
RV
545config VMLINUX_MAP
546 bool "Generate vmlinux.map file when linking"
547 depends on EXPERT
548 help
549 Selecting this option will pass "-Map=vmlinux.map" to ld
550 when linking vmlinux. That file can be useful for verifying
551 and debugging magic section games, and for seeing which
552 pieces of code get eliminated with
553 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
554
6dfc0665
DH
555config DEBUG_FORCE_WEAK_PER_CPU
556 bool "Force weak per-cpu definitions"
557 depends on DEBUG_KERNEL
8446f1d3 558 help
6dfc0665
DH
559 s390 and alpha require percpu variables in modules to be
560 defined weak to work around addressing range issue which
561 puts the following two restrictions on percpu variable
562 definitions.
8446f1d3 563
6dfc0665
DH
564 1. percpu symbols must be unique whether static or not
565 2. percpu variables can't be defined inside a function
8446f1d3 566
6dfc0665
DH
567 To ensure that generic code follows the above rules, this
568 option forces all percpu variables to be defined as weak.
5f329089 569
6dfc0665 570endmenu # "Compiler options"
8446f1d3 571
6210b640
CD
572menu "Generic Kernel Debugging Instruments"
573
6dfc0665
DH
574config MAGIC_SYSRQ
575 bool "Magic SysRq key"
576 depends on !UML
577 help
578 If you say Y here, you will have some control over the system even
579 if the system crashes for example during kernel debugging (e.g., you
580 will be able to flush the buffer cache to disk, reboot the system
581 immediately or dump some status information). This is accomplished
582 by pressing various keys while holding SysRq (Alt+PrintScreen). It
583 also works on a serial console (on PC hardware at least), if you
584 send a BREAK and then within 5 seconds a command keypress. The
f8998c22
HH
585 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
586 Don't say Y unless you really know what this hack does.
8446f1d3 587
8eaede49
BH
588config MAGIC_SYSRQ_DEFAULT_ENABLE
589 hex "Enable magic SysRq key functions by default"
590 depends on MAGIC_SYSRQ
591 default 0x1
592 help
593 Specifies which SysRq key functions are enabled by default.
594 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 595 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 596
732dbf3a
FF
597config MAGIC_SYSRQ_SERIAL
598 bool "Enable magic SysRq key over serial"
599 depends on MAGIC_SYSRQ
600 default y
601 help
602 Many embedded boards have a disconnected TTL level serial which can
603 generate some garbage that can lead to spurious false sysrq detects.
604 This option allows you to decide whether you want to enable the
605 magic SysRq key.
606
68af4317
DS
607config MAGIC_SYSRQ_SERIAL_SEQUENCE
608 string "Char sequence that enables magic SysRq over serial"
609 depends on MAGIC_SYSRQ_SERIAL
610 default ""
611 help
612 Specifies a sequence of characters that can follow BREAK to enable
613 SysRq on a serial console.
614
d3394b3d
DS
615 If unsure, leave an empty string and the option will not be enabled.
616
ec29a5c1
CD
617config DEBUG_FS
618 bool "Debug Filesystem"
619 help
620 debugfs is a virtual file system that kernel developers use to put
621 debugging files into. Enable this option to be able to read and
622 write to these files.
623
624 For detailed documentation on the debugfs API, see
625 Documentation/filesystems/.
626
627 If unsure, say N.
628
a24c6f7b
PE
629choice
630 prompt "Debugfs default access"
631 depends on DEBUG_FS
632 default DEBUG_FS_ALLOW_ALL
633 help
634 This selects the default access restrictions for debugfs.
635 It can be overridden with kernel command line option
636 debugfs=[on,no-mount,off]. The restrictions apply for API access
637 and filesystem registration.
638
639config DEBUG_FS_ALLOW_ALL
640 bool "Access normal"
641 help
642 No restrictions apply. Both API and filesystem registration
643 is on. This is the normal default operation.
644
645config DEBUG_FS_DISALLOW_MOUNT
646 bool "Do not register debugfs as filesystem"
647 help
648 The API is open but filesystem is not loaded. Clients can still do
649 their work and read with debug tools that do not need
650 debugfs filesystem.
651
652config DEBUG_FS_ALLOW_NONE
653 bool "No access"
654 help
655 Access is off. Clients get -PERM when trying to create nodes in
656 debugfs tree and debugfs is not registered as a filesystem.
657 Client can then back-off or continue without debugfs access.
658
659endchoice
660
6210b640 661source "lib/Kconfig.kgdb"
6210b640 662source "lib/Kconfig.ubsan"
2645d432 663source "lib/Kconfig.kcsan"
6210b640
CD
664
665endmenu
666
4d92b95f
ED
667menu "Networking Debugging"
668
669source "net/Kconfig.debug"
670
671endmenu # "Networking Debugging"
c66d7a27 672
0610c8a8 673menu "Memory Debugging"
fef2c9bc 674
8636a1f9 675source "mm/Kconfig.debug"
fef2c9bc 676
0610c8a8
DH
677config DEBUG_OBJECTS
678 bool "Debug object operations"
679 depends on DEBUG_KERNEL
9c44bc03 680 help
0610c8a8
DH
681 If you say Y here, additional code will be inserted into the
682 kernel to track the life time of various objects and validate
683 the operations on those objects.
9c44bc03 684
0610c8a8
DH
685config DEBUG_OBJECTS_SELFTEST
686 bool "Debug objects selftest"
687 depends on DEBUG_OBJECTS
688 help
689 This enables the selftest of the object debug code.
9c44bc03 690
0610c8a8
DH
691config DEBUG_OBJECTS_FREE
692 bool "Debug objects in freed memory"
693 depends on DEBUG_OBJECTS
694 help
695 This enables checks whether a k/v free operation frees an area
696 which contains an object which has not been deactivated
697 properly. This can make kmalloc/kfree-intensive workloads
698 much slower.
3ac7fe5a 699
c6f3a97f
TG
700config DEBUG_OBJECTS_TIMERS
701 bool "Debug timer objects"
702 depends on DEBUG_OBJECTS
703 help
704 If you say Y here, additional code will be inserted into the
705 timer routines to track the life time of timer objects and
706 validate the timer operations.
707
dc186ad7
TG
708config DEBUG_OBJECTS_WORK
709 bool "Debug work objects"
710 depends on DEBUG_OBJECTS
711 help
712 If you say Y here, additional code will be inserted into the
713 work queue routines to track the life time of work objects and
714 validate the work operations.
715
551d55a9
MD
716config DEBUG_OBJECTS_RCU_HEAD
717 bool "Debug RCU callbacks objects"
fc2ecf7e 718 depends on DEBUG_OBJECTS
551d55a9
MD
719 help
720 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
721
e2852ae8
TH
722config DEBUG_OBJECTS_PERCPU_COUNTER
723 bool "Debug percpu counter objects"
724 depends on DEBUG_OBJECTS
725 help
726 If you say Y here, additional code will be inserted into the
727 percpu counter routines to track the life time of percpu counter
728 objects and validate the percpu counter operations.
729
3ae70205
IM
730config DEBUG_OBJECTS_ENABLE_DEFAULT
731 int "debug_objects bootup default value (0-1)"
68d4b3df
KK
732 range 0 1
733 default "1"
734 depends on DEBUG_OBJECTS
735 help
736 Debug objects boot parameter default value
3ae70205 737
5035ebc6 738config SHRINKER_DEBUG
5035ebc6
RG
739 bool "Enable shrinker debugging support"
740 depends on DEBUG_FS
741 help
742 Say Y to enable the shrinker debugfs interface which provides
743 visibility into the kernel memory shrinkers subsystem.
744 Disable it to avoid an extra memory footprint.
745
b69ec42b
CM
746config HAVE_DEBUG_KMEMLEAK
747 bool
748
3bba00d7
CM
749config DEBUG_KMEMLEAK
750 bool "Kernel memory leak detector"
525c1f92 751 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 752 select DEBUG_FS
3bba00d7
CM
753 select STACKTRACE if STACKTRACE_SUPPORT
754 select KALLSYMS
b60e26a2 755 select CRC32
56a61617 756 select STACKDEPOT
993f57e0 757 select STACKDEPOT_ALWAYS_INIT if !DEBUG_KMEMLEAK_DEFAULT_OFF
3bba00d7
CM
758 help
759 Say Y here if you want to enable the memory leak
760 detector. The memory allocation/freeing is traced in a way
761 similar to the Boehm's conservative garbage collector, the
762 difference being that the orphan objects are not freed but
763 only shown in /sys/kernel/debug/kmemleak. Enabling this
764 feature will introduce an overhead to memory
700199b0 765 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
766 details.
767
0610c8a8
DH
768 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
769 of finding leaks due to the slab objects poisoning.
770
771 In order to access the kmemleak file, debugfs needs to be
772 mounted (usually at /sys/kernel/debug).
773
c5665868
CM
774config DEBUG_KMEMLEAK_MEM_POOL_SIZE
775 int "Kmemleak memory pool size"
0610c8a8 776 depends on DEBUG_KMEMLEAK
c59180ae 777 range 200 1000000
b751c52b 778 default 16000
0610c8a8
DH
779 help
780 Kmemleak must track all the memory allocations to avoid
781 reporting false positives. Since memory may be allocated or
c5665868
CM
782 freed before kmemleak is fully initialised, use a static pool
783 of metadata objects to track such callbacks. After kmemleak is
784 fully initialised, this memory pool acts as an emergency one
785 if slab allocations fail.
0610c8a8
DH
786
787config DEBUG_KMEMLEAK_TEST
788 tristate "Simple test for the kernel memory leak detector"
789 depends on DEBUG_KMEMLEAK && m
790 help
791 This option enables a module that explicitly leaks memory.
792
793 If unsure, say N.
794
795config DEBUG_KMEMLEAK_DEFAULT_OFF
796 bool "Default kmemleak to off"
797 depends on DEBUG_KMEMLEAK
798 help
799 Say Y here to disable kmemleak by default. It can then be enabled
800 on the command line via kmemleak=on.
801
d53ce042
SK
802config DEBUG_KMEMLEAK_AUTO_SCAN
803 bool "Enable kmemleak auto scan thread on boot up"
804 default y
805 depends on DEBUG_KMEMLEAK
806 help
807 Depending on the cpu, kmemleak scan may be cpu intensive and can
808 stall user tasks at times. This option enables/disables automatic
809 kmemleak scan at boot up.
810
811 Say N here to disable kmemleak auto scan thread to stop automatic
812 scanning. Disabling this option disables automatic reporting of
813 memory leaks.
814
815 If unsure, say Y.
816
0610c8a8
DH
817config DEBUG_STACK_USAGE
818 bool "Stack utilization instrumentation"
6c31da34 819 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
820 help
821 Enables the display of the minimum amount of free stack which each
822 task has ever had available in the sysrq-T and sysrq-P debug output.
823
824 This option will slow down process creation somewhat.
825
dc9b9638
CD
826config SCHED_STACK_END_CHECK
827 bool "Detect stack corruption on calls to schedule()"
828 depends on DEBUG_KERNEL
829 default n
830 help
831 This option checks for a stack overrun on calls to schedule().
832 If the stack end location is found to be over written always panic as
833 the content of the corrupted region can no longer be trusted.
834 This is to ensure no erroneous behaviour occurs which could result in
835 data corruption or a sporadic crash at a later stage once the region
836 is examined. The runtime overhead introduced is minimal.
837
399145f9
AK
838config ARCH_HAS_DEBUG_VM_PGTABLE
839 bool
840 help
841 An architecture should select this when it can successfully
842 build and run DEBUG_VM_PGTABLE.
843
a738e9ba
TG
844config DEBUG_VM_IRQSOFF
845 def_bool DEBUG_VM && !PREEMPT_RT
846
0610c8a8
DH
847config DEBUG_VM
848 bool "Debug VM"
849 depends on DEBUG_KERNEL
850 help
851 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 852 that may impact performance.
0610c8a8
DH
853
854 If unsure, say N.
855
54a611b6
LH
856config DEBUG_VM_MAPLE_TREE
857 bool "Debug VM maple trees"
4f115147 858 depends on DEBUG_VM
54a611b6 859 select DEBUG_MAPLE_TREE
4f115147 860 help
54a611b6 861 Enable VM maple tree debugging information and extra validations.
4f115147
DB
862
863 If unsure, say N.
864
0610c8a8
DH
865config DEBUG_VM_RB
866 bool "Debug VM red-black trees"
867 depends on DEBUG_VM
868 help
a663dad6 869 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
870
871 If unsure, say N.
872
95ad9755
KS
873config DEBUG_VM_PGFLAGS
874 bool "Debug page-flags operations"
875 depends on DEBUG_VM
876 help
877 Enables extra validation on page flags operations.
878
879 If unsure, say N.
880
399145f9
AK
881config DEBUG_VM_PGTABLE
882 bool "Debug arch page table for semantics compliance"
883 depends on MMU
884 depends on ARCH_HAS_DEBUG_VM_PGTABLE
885 default y if DEBUG_VM
886 help
887 This option provides a debug method which can be used to test
888 architecture page table helper functions on various platforms in
889 verifying if they comply with expected generic MM semantics. This
890 will help architecture code in making sure that any changes or
891 new additions of these helpers still conform to expected
892 semantics of the generic MM. Platforms will have to opt in for
893 this through ARCH_HAS_DEBUG_VM_PGTABLE.
894
895 If unsure, say N.
896
fa5b6ec9
LA
897config ARCH_HAS_DEBUG_VIRTUAL
898 bool
899
0610c8a8
DH
900config DEBUG_VIRTUAL
901 bool "Debug VM translations"
fa5b6ec9 902 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
903 help
904 Enable some costly sanity checks in virtual to page code. This can
905 catch mistakes with virt_to_page() and friends.
906
907 If unsure, say N.
908
909config DEBUG_NOMMU_REGIONS
910 bool "Debug the global anon/private NOMMU mapping region tree"
911 depends on DEBUG_KERNEL && !MMU
912 help
913 This option causes the global tree of anonymous and private mapping
914 regions to be regularly checked for invalid topology.
915
916config DEBUG_MEMORY_INIT
917 bool "Debug memory initialisation" if EXPERT
918 default !EXPERT
919 help
920 Enable this for additional checks during memory initialisation.
921 The sanity checks verify aspects of the VM such as the memory model
922 and other information provided by the architecture. Verbose
923 information will be printed at KERN_DEBUG loglevel depending
924 on the mminit_loglevel= command-line option.
925
926 If unsure, say Y
927
928config MEMORY_NOTIFIER_ERROR_INJECT
929 tristate "Memory hotplug notifier error injection module"
50f9481e 930 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
0610c8a8
DH
931 help
932 This option provides the ability to inject artificial errors to
933 memory hotplug notifier chain callbacks. It is controlled through
934 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
935
936 If the notifier call chain should be failed with some events
937 notified, write the error code to "actions/<notifier event>/error".
938
939 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
940
941 # cd /sys/kernel/debug/notifier-error-inject/memory
942 # echo -12 > actions/MEM_GOING_OFFLINE/error
943 # echo offline > /sys/devices/system/memory/memoryXXX/state
944 bash: echo: write error: Cannot allocate memory
945
946 To compile this code as a module, choose M here: the module will
947 be called memory-notifier-error-inject.
948
949 If unsure, say N.
950
951config DEBUG_PER_CPU_MAPS
952 bool "Debug access to per_cpu maps"
953 depends on DEBUG_KERNEL
954 depends on SMP
955 help
956 Say Y to verify that the per_cpu map being accessed has
957 been set up. This adds a fair amount of code to kernel memory
958 and decreases performance.
959
960 Say N if unsure.
961
6e799cb6
TG
962config DEBUG_KMAP_LOCAL
963 bool "Debug kmap_local temporary mappings"
964 depends on DEBUG_KERNEL && KMAP_LOCAL
965 help
966 This option enables additional error checking for the kmap_local
967 infrastructure. Disable for production use.
968
0e91a0c6
TG
969config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
970 bool
971
972config DEBUG_KMAP_LOCAL_FORCE_MAP
973 bool "Enforce kmap_local temporary mappings"
974 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
975 select KMAP_LOCAL
976 select DEBUG_KMAP_LOCAL
977 help
978 This option enforces temporary mappings through the kmap_local
979 mechanism for non-highmem pages and on non-highmem systems.
980 Disable this for production systems!
981
0610c8a8
DH
982config DEBUG_HIGHMEM
983 bool "Highmem debugging"
984 depends on DEBUG_KERNEL && HIGHMEM
0e91a0c6 985 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
6e799cb6 986 select DEBUG_KMAP_LOCAL
0610c8a8 987 help
b1357c9f
GU
988 This option enables additional error checking for high memory
989 systems. Disable for production systems.
0610c8a8
DH
990
991config HAVE_DEBUG_STACKOVERFLOW
992 bool
993
994config DEBUG_STACKOVERFLOW
995 bool "Check for stack overflows"
996 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 997 help
0610c8a8 998 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 999 and exception stacks (if your architecture uses them). This
0610c8a8
DH
1000 option will show detailed messages if free stack space drops
1001 below a certain limit.
1002
1003 These kinds of bugs usually occur when call-chains in the
1004 kernel get too deep, especially when interrupts are
1005 involved.
1006
1007 Use this in cases where you see apparently random memory
1008 corruption, especially if it appears in 'struct thread_info'
1009
1010 If in doubt, say "N".
1011
0b24becc 1012source "lib/Kconfig.kasan"
0ce20dd8 1013source "lib/Kconfig.kfence"
f80be457 1014source "lib/Kconfig.kmsan"
0b24becc 1015
0610c8a8
DH
1016endmenu # "Memory Debugging"
1017
a304e1b8
DW
1018config DEBUG_SHIRQ
1019 bool "Debug shared IRQ handlers"
0244ad00 1020 depends on DEBUG_KERNEL
a304e1b8 1021 help
0a2fae2a
WS
1022 Enable this to generate a spurious interrupt just before a shared
1023 interrupt handler is deregistered (generating one when registering
1024 is currently disabled). Drivers need to handle this correctly. Some
1025 don't and need to be caught.
a304e1b8 1026
f43a289d
CD
1027menu "Debug Oops, Lockups and Hangs"
1028
1029config PANIC_ON_OOPS
1030 bool "Panic on Oops"
1031 help
1032 Say Y here to enable the kernel to panic when it oopses. This
1033 has the same effect as setting oops=panic on the kernel command
1034 line.
1035
1036 This feature is useful to ensure that the kernel does not do
1037 anything erroneous after an oops which could result in data
1038 corruption or other issues.
1039
1040 Say N if unsure.
1041
1042config PANIC_ON_OOPS_VALUE
1043 int
1044 range 0 1
1045 default 0 if !PANIC_ON_OOPS
1046 default 1 if PANIC_ON_OOPS
1047
1048config PANIC_TIMEOUT
1049 int "panic timeout"
1050 default 0
1051 help
9d5b134f 1052 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
1053 the kernel panics. If n = 0, then we wait forever. A timeout
1054 value n > 0 will wait n seconds before rebooting, while a timeout
1055 value n < 0 will reboot immediately.
92aef8fb 1056
58687acb 1057config LOCKUP_DETECTOR
05a4a952
NP
1058 bool
1059
1060config SOFTLOCKUP_DETECTOR
1061 bool "Detect Soft Lockups"
dea20a3f 1062 depends on DEBUG_KERNEL && !S390
05a4a952 1063 select LOCKUP_DETECTOR
8446f1d3 1064 help
58687acb 1065 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 1066 soft lockups.
58687acb
DZ
1067
1068 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 1069 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
1070 chance to run. The current stack trace is displayed upon
1071 detection and the system will stay locked up.
8446f1d3 1072
5f00ae0d
RD
1073config BOOTPARAM_SOFTLOCKUP_PANIC
1074 bool "Panic (Reboot) On Soft Lockups"
1075 depends on SOFTLOCKUP_DETECTOR
1076 help
1077 Say Y here to enable the kernel to panic on "soft lockups",
1078 which are bugs that cause the kernel to loop in kernel
1079 mode for more than 20 seconds (configurable using the watchdog_thresh
1080 sysctl), without giving other tasks a chance to run.
1081
1082 The panic can be used in combination with panic_timeout,
1083 to cause the system to reboot automatically after a
1084 lockup has been detected. This feature is useful for
1085 high-availability systems that have uptime guarantees and
1086 where a lockup must be resolved ASAP.
1087
1088 Say N if unsure.
1089
05a4a952
NP
1090config HARDLOCKUP_DETECTOR_PERF
1091 bool
1092 select SOFTLOCKUP_DETECTOR
1093
7edaeb68
TG
1094#
1095# Enables a timestamp based low pass filter to compensate for perf based
1096# hard lockup detection which runs too fast due to turbo modes.
1097#
1098config HARDLOCKUP_CHECK_TIMESTAMP
1099 bool
1100
05a4a952
NP
1101#
1102# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1103# lockup detector rather than the perf based detector.
1104#
1105config HARDLOCKUP_DETECTOR
1106 bool "Detect Hard Lockups"
1107 depends on DEBUG_KERNEL && !S390
1108 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1109 select LOCKUP_DETECTOR
1110 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
05a4a952
NP
1111 help
1112 Say Y here to enable the kernel to act as a watchdog to detect
1113 hard lockups.
1114
58687acb 1115 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 1116 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
1117 chance to run. The current stack trace is displayed upon detection
1118 and the system will stay locked up.
8446f1d3 1119
fef2c9bc
DZ
1120config BOOTPARAM_HARDLOCKUP_PANIC
1121 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 1122 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1123 help
1124 Say Y here to enable the kernel to panic on "hard lockups",
1125 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1126 mode with interrupts disabled for more than 10 seconds (configurable
1127 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1128
1129 Say N if unsure.
1130
e162b39a
MSB
1131config DETECT_HUNG_TASK
1132 bool "Detect Hung Tasks"
1133 depends on DEBUG_KERNEL
05a4a952 1134 default SOFTLOCKUP_DETECTOR
e162b39a 1135 help
0610c8a8
DH
1136 Say Y here to enable the kernel to detect "hung tasks",
1137 which are bugs that cause the task to be stuck in
96b03ab8 1138 uninterruptible "D" state indefinitely.
1da177e4 1139
0610c8a8
DH
1140 When a hung task is detected, the kernel will print the
1141 current stack trace (which you should report), but the
1142 task will stay in uninterruptible state. If lockdep is
1143 enabled then all held locks will also be reported. This
1144 feature has negligible overhead.
871751e2 1145
0610c8a8
DH
1146config DEFAULT_HUNG_TASK_TIMEOUT
1147 int "Default timeout for hung task detection (in seconds)"
1148 depends on DETECT_HUNG_TASK
1149 default 120
f0630fff 1150 help
0610c8a8
DH
1151 This option controls the default timeout (in seconds) used
1152 to determine when a task has become non-responsive and should
1153 be considered hung.
f0630fff 1154
0610c8a8
DH
1155 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1156 sysctl or by writing a value to
1157 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1158
0610c8a8
DH
1159 A timeout of 0 disables the check. The default is two minutes.
1160 Keeping the default should be fine in most cases.
b69ec42b 1161
0610c8a8
DH
1162config BOOTPARAM_HUNG_TASK_PANIC
1163 bool "Panic (Reboot) On Hung Tasks"
1164 depends on DETECT_HUNG_TASK
3bba00d7 1165 help
0610c8a8
DH
1166 Say Y here to enable the kernel to panic on "hung tasks",
1167 which are bugs that cause the kernel to leave a task stuck
1168 in uninterruptible "D" state.
3bba00d7 1169
0610c8a8
DH
1170 The panic can be used in combination with panic_timeout,
1171 to cause the system to reboot automatically after a
1172 hung task has been detected. This feature is useful for
1173 high-availability systems that have uptime guarantees and
1174 where a hung tasks must be resolved ASAP.
bf96d1e3 1175
0610c8a8 1176 Say N if unsure.
bf96d1e3 1177
82607adc
TH
1178config WQ_WATCHDOG
1179 bool "Detect Workqueue Stalls"
1180 depends on DEBUG_KERNEL
1181 help
1182 Say Y here to enable stall detection on workqueues. If a
1183 worker pool doesn't make forward progress on a pending work
1184 item for over a given amount of time, 30s by default, a
1185 warning message is printed along with dump of workqueue
1186 state. This can be configured through kernel parameter
1187 "workqueue.watchdog_thresh" and its sysfs counterpart.
1188
30428ef5
KK
1189config TEST_LOCKUP
1190 tristate "Test module to generate lockups"
63646bc9 1191 depends on m
30428ef5
KK
1192 help
1193 This builds the "test_lockup" module that helps to make sure
1194 that watchdogs and lockup detectors are working properly.
1195
1196 Depending on module parameters it could emulate soft or hard
1197 lockup, "hung task", or locking arbitrary lock for a long time.
1198 Also it could generate series of lockups with cooling-down periods.
1199
1200 If unsure, say N.
1201
92aef8fb
DH
1202endmenu # "Debug lockups and hangs"
1203
ebebdd09 1204menu "Scheduler Debugging"
5800dc3c 1205
0610c8a8
DH
1206config SCHED_DEBUG
1207 bool "Collect scheduler debugging info"
1208 depends on DEBUG_KERNEL && PROC_FS
1209 default y
0822ee4a 1210 help
0610c8a8
DH
1211 If you say Y here, the /proc/sched_debug file will be provided
1212 that can help debug the scheduler. The runtime overhead of this
1213 option is minimal.
0822ee4a 1214
f6db8347
NR
1215config SCHED_INFO
1216 bool
1217 default n
1218
0610c8a8
DH
1219config SCHEDSTATS
1220 bool "Collect scheduler statistics"
1221 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1222 select SCHED_INFO
0610c8a8
DH
1223 help
1224 If you say Y here, additional code will be inserted into the
1225 scheduler and related routines to collect statistics about
1226 scheduler behavior and provide them in /proc/schedstat. These
1227 stats may be useful for both tuning and debugging the scheduler
1228 If you aren't debugging the scheduler or trying to tune a specific
1229 application, you can say N to avoid the very slight overhead
1230 this adds.
0822ee4a 1231
ebebdd09 1232endmenu
0d9e2632 1233
3c17ad19
JS
1234config DEBUG_TIMEKEEPING
1235 bool "Enable extra timekeeping sanity checking"
1236 help
1237 This option will enable additional timekeeping sanity checks
1238 which may be helpful when diagnosing issues where timekeeping
1239 problems are suspected.
1240
1241 This may include checks in the timekeeping hotpaths, so this
1242 option may have a (very small) performance impact to some
1243 workloads.
1244
1245 If unsure, say N.
1246
1da177e4
LT
1247config DEBUG_PREEMPT
1248 bool "Debug preemptible kernel"
9f472869 1249 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1250 default y
1251 help
1252 If you say Y here then the kernel will use a debug variant of the
1253 commonly used smp_processor_id() function and will print warnings
1254 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1255 will detect preemption count underflows.
1256
9eade16b
DH
1257menu "Lock Debugging (spinlocks, mutexes, etc...)"
1258
f07cbebb
WL
1259config LOCK_DEBUGGING_SUPPORT
1260 bool
1261 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1262 default y
1263
19193bca
WL
1264config PROVE_LOCKING
1265 bool "Lock debugging: prove locking correctness"
1266 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1267 select LOCKDEP
1268 select DEBUG_SPINLOCK
bb630f9f 1269 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca 1270 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1271 select DEBUG_RWSEMS
19193bca
WL
1272 select DEBUG_WW_MUTEX_SLOWPATH
1273 select DEBUG_LOCK_ALLOC
8fd8ad5c 1274 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1275 select TRACE_IRQFLAGS
1276 default n
1277 help
1278 This feature enables the kernel to prove that all locking
1279 that occurs in the kernel runtime is mathematically
1280 correct: that under no circumstance could an arbitrary (and
1281 not yet triggered) combination of observed locking
1282 sequences (on an arbitrary number of CPUs, running an
1283 arbitrary number of tasks and interrupt contexts) cause a
1284 deadlock.
1285
1286 In short, this feature enables the kernel to report locking
1287 related deadlocks before they actually occur.
1288
1289 The proof does not depend on how hard and complex a
1290 deadlock scenario would be to trigger: how many
1291 participant CPUs, tasks and irq-contexts would be needed
1292 for it to trigger. The proof also does not depend on
1293 timing: if a race and a resulting deadlock is possible
1294 theoretically (no matter how unlikely the race scenario
1295 is), it will be proven so and will immediately be
1296 reported by the kernel (once the event is observed that
1297 makes the deadlock theoretically possible).
1298
1299 If a deadlock is impossible (i.e. the locking rules, as
1300 observed by the kernel, are mathematically correct), the
1301 kernel reports nothing.
1302
1303 NOTE: this feature can also be enabled for rwlocks, mutexes
1304 and rwsems - in which case all dependencies between these
1305 different locking variants are observed and mapped too, and
1306 the proof of observed correctness is also maintained for an
1307 arbitrary combination of these separate locking variants.
1308
387b1468 1309 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1310
de8f5e4f
PZ
1311config PROVE_RAW_LOCK_NESTING
1312 bool "Enable raw_spinlock - spinlock nesting checks"
1313 depends on PROVE_LOCKING
1314 default n
1315 help
1316 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1317 that the lock nesting rules for PREEMPT_RT enabled kernels are
1318 not violated.
1319
1320 NOTE: There are known nesting problems. So if you enable this
1321 option expect lockdep splats until these problems have been fully
1322 addressed which is work in progress. This config switch allows to
1323 identify and analyze these problems. It will be removed and the
9dbbc3b9 1324 check permanently enabled once the main issues have been fixed.
de8f5e4f
PZ
1325
1326 If unsure, select N.
1327
19193bca
WL
1328config LOCK_STAT
1329 bool "Lock usage statistics"
1330 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1331 select LOCKDEP
1332 select DEBUG_SPINLOCK
bb630f9f 1333 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca
WL
1334 select DEBUG_RT_MUTEXES if RT_MUTEXES
1335 select DEBUG_LOCK_ALLOC
1336 default n
1337 help
1338 This feature enables tracking lock contention points
1339
387b1468 1340 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1341
1342 This also enables lock events required by "perf lock",
1343 subcommand of perf.
1344 If you want to use "perf lock", you also need to turn on
1345 CONFIG_EVENT_TRACING.
1346
1347 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1348 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1349
e7eebaf6
IM
1350config DEBUG_RT_MUTEXES
1351 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1352 depends on DEBUG_KERNEL && RT_MUTEXES
1353 help
1354 This allows rt mutex semantics violations and rt mutex related
1355 deadlocks (lockups) to be detected and reported automatically.
1356
1da177e4 1357config DEBUG_SPINLOCK
4d9f34ad 1358 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1359 depends on DEBUG_KERNEL
e335e3eb 1360 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1361 help
1362 Say Y here and build SMP to catch missing spinlock initialization
1363 and certain other kinds of spinlock errors commonly made. This is
1364 best used in conjunction with the NMI watchdog so that spinlock
1365 deadlocks are also debuggable.
1366
4d9f34ad
IM
1367config DEBUG_MUTEXES
1368 bool "Mutex debugging: basic checks"
bb630f9f 1369 depends on DEBUG_KERNEL && !PREEMPT_RT
4d9f34ad
IM
1370 help
1371 This feature allows mutex semantics violations to be detected and
1372 reported.
1373
23010027
DV
1374config DEBUG_WW_MUTEX_SLOWPATH
1375 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1376 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1377 select DEBUG_LOCK_ALLOC
1378 select DEBUG_SPINLOCK
bb630f9f
TG
1379 select DEBUG_MUTEXES if !PREEMPT_RT
1380 select DEBUG_RT_MUTEXES if PREEMPT_RT
23010027
DV
1381 help
1382 This feature enables slowpath testing for w/w mutex users by
1383 injecting additional -EDEADLK wound/backoff cases. Together with
1384 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1385 will test all possible w/w mutex interface abuse with the
1386 exception of simply not acquiring all the required locks.
4d692373
RC
1387 Note that this feature can introduce significant overhead, so
1388 it really should not be enabled in a production or distro kernel,
1389 even a debug kernel. If you are a driver writer, enable it. If
1390 you are a distro, do not.
23010027 1391
5149cbac
WL
1392config DEBUG_RWSEMS
1393 bool "RW Semaphore debugging: basic checks"
c71fd893 1394 depends on DEBUG_KERNEL
5149cbac 1395 help
c71fd893
WL
1396 This debugging feature allows mismatched rw semaphore locks
1397 and unlocks to be detected and reported.
5149cbac 1398
4d9f34ad
IM
1399config DEBUG_LOCK_ALLOC
1400 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1401 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1402 select DEBUG_SPINLOCK
bb630f9f 1403 select DEBUG_MUTEXES if !PREEMPT_RT
f5694788 1404 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1405 select LOCKDEP
1406 help
1407 This feature will check whether any held lock (spinlock, rwlock,
1408 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1409 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1410 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1411 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1412 held during task exit.
1413
4d9f34ad
IM
1414config LOCKDEP
1415 bool
f07cbebb 1416 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1417 select STACKTRACE
4d9f34ad
IM
1418 select KALLSYMS
1419 select KALLSYMS_ALL
1420
395102db
DJ
1421config LOCKDEP_SMALL
1422 bool
1423
5dc33592
TH
1424config LOCKDEP_BITS
1425 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1426 depends on LOCKDEP && !LOCKDEP_SMALL
1427 range 10 30
1428 default 15
1429 help
1430 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1431
1432config LOCKDEP_CHAINS_BITS
1433 int "Bitsize for MAX_LOCKDEP_CHAINS"
1434 depends on LOCKDEP && !LOCKDEP_SMALL
1435 range 10 30
1436 default 16
1437 help
1438 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1439
1440config LOCKDEP_STACK_TRACE_BITS
1441 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1442 depends on LOCKDEP && !LOCKDEP_SMALL
1443 range 10 30
1444 default 19
1445 help
1446 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1447
1448config LOCKDEP_STACK_TRACE_HASH_BITS
1449 int "Bitsize for STACK_TRACE_HASH_SIZE"
1450 depends on LOCKDEP && !LOCKDEP_SMALL
1451 range 10 30
1452 default 14
1453 help
1454 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1455
1456config LOCKDEP_CIRCULAR_QUEUE_BITS
1457 int "Bitsize for elements in circular_queue struct"
1458 depends on LOCKDEP
1459 range 10 30
1460 default 12
1461 help
1462 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1463
4d9f34ad
IM
1464config DEBUG_LOCKDEP
1465 bool "Lock dependency engine debugging"
517e7aa5 1466 depends on DEBUG_KERNEL && LOCKDEP
997acaf6 1467 select DEBUG_IRQFLAGS
4d9f34ad
IM
1468 help
1469 If you say Y here, the lock dependency engine will do
1470 additional runtime checks to debug itself, at the price
1471 of more runtime overhead.
1472
d902db1e
FW
1473config DEBUG_ATOMIC_SLEEP
1474 bool "Sleep inside atomic section checking"
e8f7c70f 1475 select PREEMPT_COUNT
1da177e4 1476 depends on DEBUG_KERNEL
87a4c375 1477 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1478 help
1479 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1480 noisy if they are called inside atomic sections: when a spinlock is
1481 held, inside an rcu read side critical section, inside preempt disabled
1482 sections, inside an interrupt, etc...
1da177e4 1483
cae2ed9a
IM
1484config DEBUG_LOCKING_API_SELFTESTS
1485 bool "Locking API boot-time self-tests"
1486 depends on DEBUG_KERNEL
1487 help
1488 Say Y here if you want the kernel to run a short self-test during
1489 bootup. The self-test checks whether common types of locking bugs
1490 are detected by debugging mechanisms or not. (if you disable
9dbbc3b9 1491 lock debugging then those bugs won't be detected of course.)
cae2ed9a
IM
1492 The following locking APIs are covered: spinlocks, rwlocks,
1493 mutexes and rwsems.
1494
0af3fe1e
PM
1495config LOCK_TORTURE_TEST
1496 tristate "torture tests for locking"
1497 depends on DEBUG_KERNEL
1498 select TORTURE_TEST
0af3fe1e
PM
1499 help
1500 This option provides a kernel module that runs torture tests
1501 on kernel locking primitives. The kernel module may be built
1502 after the fact on the running kernel to be tested, if desired.
1503
1504 Say Y here if you want kernel locking-primitive torture tests
1505 to be built into the kernel.
1506 Say M if you want these torture tests to build as a module.
1507 Say N if you are unsure.
1508
f2a5fec1
CW
1509config WW_MUTEX_SELFTEST
1510 tristate "Wait/wound mutex selftests"
1511 help
1512 This option provides a kernel module that runs tests on the
1513 on the struct ww_mutex locking API.
1514
1515 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1516 with this test harness.
1517
1518 Say M if you want these self tests to build as a module.
1519 Say N if you are unsure.
1520
e9d338a0
PM
1521config SCF_TORTURE_TEST
1522 tristate "torture tests for smp_call_function*()"
1523 depends on DEBUG_KERNEL
1524 select TORTURE_TEST
1525 help
1526 This option provides a kernel module that runs torture tests
1527 on the smp_call_function() family of primitives. The kernel
1528 module may be built after the fact on the running kernel to
1529 be tested, if desired.
1530
35feb604
PM
1531config CSD_LOCK_WAIT_DEBUG
1532 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1533 depends on DEBUG_KERNEL
1534 depends on 64BIT
1535 default n
1536 help
1537 This option enables debug prints when CPUs are slow to respond
1538 to the smp_call_function*() IPI wrappers. These debug prints
1539 include the IPI handler function currently executing (if any)
1540 and relevant stack traces.
1541
9eade16b 1542endmenu # lock debugging
8637c099 1543
9eade16b 1544config TRACE_IRQFLAGS
ed004953 1545 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1546 bool
5ca43f6c 1547 help
9eade16b
DH
1548 Enables hooks to interrupt enabling and disabling for
1549 either tracing or lock debugging.
5ca43f6c 1550
ed004953 1551config TRACE_IRQFLAGS_NMI
1552 def_bool y
1553 depends on TRACE_IRQFLAGS
1554 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1555
997acaf6
MR
1556config DEBUG_IRQFLAGS
1557 bool "Debug IRQ flag manipulation"
1558 help
1559 Enables checks for potentially unsafe enabling or disabling of
1560 interrupts, such as calling raw_local_irq_restore() when interrupts
1561 are enabled.
1562
8637c099 1563config STACKTRACE
0c38e1fe 1564 bool "Stack backtrace support"
8637c099 1565 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1566 help
1567 This option causes the kernel to create a /proc/pid/stack for
1568 every process, showing its current stack trace.
1569 It is also used by various kernel debugging features that require
1570 stack trace generation.
5ca43f6c 1571
eecabf56
TT
1572config WARN_ALL_UNSEEDED_RANDOM
1573 bool "Warn for all uses of unseeded randomness"
1574 default n
d06bfd19
JD
1575 help
1576 Some parts of the kernel contain bugs relating to their use of
1577 cryptographically secure random numbers before it's actually possible
1578 to generate those numbers securely. This setting ensures that these
1579 flaws don't go unnoticed, by enabling a message, should this ever
1580 occur. This will allow people with obscure setups to know when things
1581 are going wrong, so that they might contact developers about fixing
1582 it.
1583
eecabf56
TT
1584 Unfortunately, on some models of some architectures getting
1585 a fully seeded CRNG is extremely difficult, and so this can
1586 result in dmesg getting spammed for a surprisingly long
1587 time. This is really bad from a security perspective, and
1588 so architecture maintainers really need to do what they can
1589 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1590 However, since users cannot do anything actionable to
cc1e127b 1591 address this, by default this option is disabled.
eecabf56
TT
1592
1593 Say Y here if you want to receive warnings for all uses of
1594 unseeded randomness. This will be of use primarily for
4c5d114e 1595 those developers interested in improving the security of
eecabf56
TT
1596 Linux kernels running on their architecture (or
1597 subarchitecture).
d06bfd19 1598
1da177e4
LT
1599config DEBUG_KOBJECT
1600 bool "kobject debugging"
1601 depends on DEBUG_KERNEL
1602 help
1603 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1604 to the syslog.
1da177e4 1605
c817a67e
RK
1606config DEBUG_KOBJECT_RELEASE
1607 bool "kobject release debugging"
2a999aa0 1608 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1609 help
1610 kobjects are reference counted objects. This means that their
1611 last reference count put is not predictable, and the kobject can
b6c69474 1612 live on past the point at which a driver decides to drop its
c817a67e
RK
1613 initial reference to the kobject gained on allocation. An
1614 example of this would be a struct device which has just been
1615 unregistered.
1616
1617 However, some buggy drivers assume that after such an operation,
1618 the memory backing the kobject can be immediately freed. This
1619 goes completely against the principles of a refcounted object.
1620
1621 If you say Y here, the kernel will delay the release of kobjects
1622 on the last reference count to improve the visibility of this
1623 kind of kobject release bug.
1624
9b2a60c4
CM
1625config HAVE_DEBUG_BUGVERBOSE
1626 bool
1627
3be5cbcd 1628menu "Debug kernel data structures"
1da177e4 1629
199a9afc
DJ
1630config DEBUG_LIST
1631 bool "Debug linked list manipulation"
4520bcb2 1632 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1633 help
1634 Enable this to turn on extended checks in the linked-list
1635 walking routines.
1636
1637 If unsure, say N.
1638
8e18faea 1639config DEBUG_PLIST
b8cfff68
DS
1640 bool "Debug priority linked list manipulation"
1641 depends on DEBUG_KERNEL
1642 help
1643 Enable this to turn on extended checks in the priority-ordered
1644 linked-list (plist) walking routines. This checks the entire
1645 list multiple times during each manipulation.
1646
1647 If unsure, say N.
1648
d6ec0842
JA
1649config DEBUG_SG
1650 bool "Debug SG table operations"
1651 depends on DEBUG_KERNEL
1652 help
1653 Enable this to turn on checks on scatter-gather tables. This can
1654 help find problems with drivers that do not properly initialize
1655 their sg tables.
1656
1657 If unsure, say N.
1658
1b2439db
AV
1659config DEBUG_NOTIFIERS
1660 bool "Debug notifier call chains"
1661 depends on DEBUG_KERNEL
1662 help
1663 Enable this to turn on sanity checking for notifier call chains.
1664 This is most useful for kernel developers to make sure that
1665 modules properly unregister themselves from notifier chains.
1666 This is a relatively cheap check but if you care about maximum
1667 performance, say N.
1668
3be5cbcd
CD
1669config BUG_ON_DATA_CORRUPTION
1670 bool "Trigger a BUG when data corruption is detected"
1671 select DEBUG_LIST
1672 help
1673 Select this option if the kernel should BUG when it encounters
1674 data corruption in kernel memory structures when they get checked
1675 for validity.
1676
1677 If unsure, say N.
1678
54a611b6
LH
1679config DEBUG_MAPLE_TREE
1680 bool "Debug maple trees"
1681 depends on DEBUG_KERNEL
1682 help
1683 Enable maple tree debugging information and extra validations.
1684
1685 If unsure, say N.
1686
3be5cbcd
CD
1687endmenu
1688
e0e81739
DH
1689config DEBUG_CREDENTIALS
1690 bool "Debug credential management"
1691 depends on DEBUG_KERNEL
1692 help
1693 Enable this to turn on some debug checking for credential
1694 management. The additional code keeps track of the number of
1695 pointers from task_structs to any given cred struct, and checks to
1696 see that this number never exceeds the usage count of the cred
1697 struct.
1698
1699 Furthermore, if SELinux is enabled, this also checks that the
1700 security pointer in the cred struct is never seen to be invalid.
1701
1702 If unsure, say N.
1703
43a0a2a7 1704source "kernel/rcu/Kconfig.debug"
2f03e3ca 1705
f303fccb
TH
1706config DEBUG_WQ_FORCE_RR_CPU
1707 bool "Force round-robin CPU selection for unbound work items"
1708 depends on DEBUG_KERNEL
1709 default n
1710 help
1711 Workqueue used to implicitly guarantee that work items queued
1712 without explicit CPU specified are put on the local CPU. This
1713 guarantee is no longer true and while local CPU is still
1714 preferred work items may be put on foreign CPUs. Kernel
1715 parameter "workqueue.debug_force_rr_cpu" is added to force
1716 round-robin CPU selection to flush out usages which depend on the
1717 now broken guarantee. This config option enables the debug
1718 feature by default. When enabled, memory and cache locality will
1719 be impacted.
1720
757c989b
TG
1721config CPU_HOTPLUG_STATE_CONTROL
1722 bool "Enable CPU hotplug state control"
1723 depends on DEBUG_KERNEL
1724 depends on HOTPLUG_CPU
1725 default n
1726 help
1727 Allows to write steps between "offline" and "online" to the CPUs
1728 sysfs target file so states can be stepped granular. This is a debug
1729 option for now as the hotplug machinery cannot be stopped and
1730 restarted at arbitrary points yet.
1731
1732 Say N if your are unsure.
1733
09a74952
CD
1734config LATENCYTOP
1735 bool "Latency measuring infrastructure"
1736 depends on DEBUG_KERNEL
1737 depends on STACKTRACE_SUPPORT
1738 depends on PROC_FS
7d37cb2c 1739 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
09a74952
CD
1740 select KALLSYMS
1741 select KALLSYMS_ALL
1742 select STACKTRACE
1743 select SCHEDSTATS
09a74952
CD
1744 help
1745 Enable this option if you want to use the LatencyTOP tool
1746 to find out which userspace is blocking on what kernel operations.
1747
6ab42860
TH
1748config DEBUG_CGROUP_REF
1749 bool "Disable inlining of cgroup css reference count functions"
1750 depends on DEBUG_KERNEL
1751 depends on CGROUPS
1752 depends on KPROBES
1753 default n
1754 help
1755 Force cgroup css reference count functions to not be inlined so
1756 that they can be kprobed for debugging.
1757
09a74952
CD
1758source "kernel/trace/Kconfig"
1759
1760config PROVIDE_OHCI1394_DMA_INIT
1761 bool "Remote debugging over FireWire early on boot"
1762 depends on PCI && X86
1763 help
1764 If you want to debug problems which hang or crash the kernel early
1765 on boot and the crashing machine has a FireWire port, you can use
1766 this feature to remotely access the memory of the crashed machine
1767 over FireWire. This employs remote DMA as part of the OHCI1394
1768 specification which is now the standard for FireWire controllers.
1769
1770 With remote DMA, you can monitor the printk buffer remotely using
1771 firescope and access all memory below 4GB using fireproxy from gdb.
1772 Even controlling a kernel debugger is possible using remote DMA.
1773
1774 Usage:
1775
1776 If ohci1394_dma=early is used as boot parameter, it will initialize
1777 all OHCI1394 controllers which are found in the PCI config space.
1778
1779 As all changes to the FireWire bus such as enabling and disabling
1780 devices cause a bus reset and thereby disable remote DMA for all
1781 devices, be sure to have the cable plugged and FireWire enabled on
1782 the debugging host before booting the debug target for debugging.
1783
1784 This code (~1k) is freed after boot. By then, the firewire stack
1785 in charge of the OHCI-1394 controllers should be used instead.
1786
a74e2a22 1787 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1788
045f6d79
CD
1789source "samples/Kconfig"
1790
1791config ARCH_HAS_DEVMEM_IS_ALLOWED
1792 bool
1793
1794config STRICT_DEVMEM
1795 bool "Filter access to /dev/mem"
1796 depends on MMU && DEVMEM
527701ed 1797 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
045f6d79
CD
1798 default y if PPC || X86 || ARM64
1799 help
1800 If this option is disabled, you allow userspace (root) access to all
1801 of memory, including kernel and userspace memory. Accidental
1802 access to this is obviously disastrous, but specific access can
1803 be used by people debugging the kernel. Note that with PAT support
1804 enabled, even in this case there are restrictions on /dev/mem
1805 use due to the cache aliasing requirements.
1806
1807 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1808 file only allows userspace access to PCI space and the BIOS code and
1809 data regions. This is sufficient for dosemu and X and all common
1810 users of /dev/mem.
1811
1812 If in doubt, say Y.
1813
1814config IO_STRICT_DEVMEM
1815 bool "Filter I/O access to /dev/mem"
1816 depends on STRICT_DEVMEM
1817 help
1818 If this option is disabled, you allow userspace (root) access to all
1819 io-memory regardless of whether a driver is actively using that
1820 range. Accidental access to this is obviously disastrous, but
1821 specific access can be used by people debugging kernel drivers.
1822
1823 If this option is switched on, the /dev/mem file only allows
1824 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1825 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1826 if the driver using a given range cannot be disabled.
1827
1828 If in doubt, say Y.
1829
1830menu "$(SRCARCH) Debugging"
1831
1832source "arch/$(SRCARCH)/Kconfig.debug"
1833
1834endmenu
1835
1836menu "Kernel Testing and Coverage"
1837
09a74952
CD
1838source "lib/kunit/Kconfig"
1839
8d438288
AM
1840config NOTIFIER_ERROR_INJECTION
1841 tristate "Notifier error injection"
1842 depends on DEBUG_KERNEL
1843 select DEBUG_FS
1844 help
e41e85cc 1845 This option provides the ability to inject artificial errors to
8d438288
AM
1846 specified notifier chain callbacks. It is useful to test the error
1847 handling of notifier call chain failures.
1848
1849 Say N if unsure.
1850
048b9c35
AM
1851config PM_NOTIFIER_ERROR_INJECT
1852 tristate "PM notifier error injection module"
1853 depends on PM && NOTIFIER_ERROR_INJECTION
1854 default m if PM_DEBUG
1855 help
e41e85cc 1856 This option provides the ability to inject artificial errors to
048b9c35
AM
1857 PM notifier chain callbacks. It is controlled through debugfs
1858 interface /sys/kernel/debug/notifier-error-inject/pm
1859
1860 If the notifier call chain should be failed with some events
1861 notified, write the error code to "actions/<notifier event>/error".
1862
1863 Example: Inject PM suspend error (-12 = -ENOMEM)
1864
1865 # cd /sys/kernel/debug/notifier-error-inject/pm/
1866 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1867 # echo mem > /sys/power/state
1868 bash: echo: write error: Cannot allocate memory
1869
1870 To compile this code as a module, choose M here: the module will
1871 be called pm-notifier-error-inject.
1872
1873 If unsure, say N.
1874
d526e85f
BH
1875config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1876 tristate "OF reconfig notifier error injection module"
1877 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1878 help
e41e85cc 1879 This option provides the ability to inject artificial errors to
d526e85f 1880 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1881 through debugfs interface under
d526e85f 1882 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1883
1884 If the notifier call chain should be failed with some events
1885 notified, write the error code to "actions/<notifier event>/error".
1886
1887 To compile this code as a module, choose M here: the module will
e12a95f4 1888 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1889
1890 If unsure, say N.
1891
02fff96a
NA
1892config NETDEV_NOTIFIER_ERROR_INJECT
1893 tristate "Netdev notifier error injection module"
1894 depends on NET && NOTIFIER_ERROR_INJECTION
1895 help
1896 This option provides the ability to inject artificial errors to
1897 netdevice notifier chain callbacks. It is controlled through debugfs
1898 interface /sys/kernel/debug/notifier-error-inject/netdev
1899
1900 If the notifier call chain should be failed with some events
1901 notified, write the error code to "actions/<notifier event>/error".
1902
1903 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1904
1905 # cd /sys/kernel/debug/notifier-error-inject/netdev
1906 # echo -22 > actions/NETDEV_CHANGEMTU/error
1907 # ip link set eth0 mtu 1024
1908 RTNETLINK answers: Invalid argument
1909
1910 To compile this code as a module, choose M here: the module will
1911 be called netdev-notifier-error-inject.
1912
1913 If unsure, say N.
1914
f1b4bd06 1915config FUNCTION_ERROR_INJECTION
a4412fdd 1916 bool "Fault-injections of functions"
f1b4bd06 1917 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
a4412fdd
SRG
1918 help
1919 Add fault injections into various functions that are annotated with
1920 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
1921 value of theses functions. This is useful to test error paths of code.
1922
1923 If unsure, say N
f1b4bd06 1924
6ff1cb35 1925config FAULT_INJECTION
1ab8509a
AM
1926 bool "Fault-injection framework"
1927 depends on DEBUG_KERNEL
329409ae
AM
1928 help
1929 Provide fault-injection framework.
1930 For more details, see Documentation/fault-injection/.
6ff1cb35 1931
8a8b6502 1932config FAILSLAB
1ab8509a
AM
1933 bool "Fault-injection capability for kmalloc"
1934 depends on FAULT_INJECTION
773ff60e 1935 depends on SLAB || SLUB
8a8b6502 1936 help
1ab8509a 1937 Provide fault-injection capability for kmalloc.
8a8b6502 1938
933e312e 1939config FAIL_PAGE_ALLOC
29b46fa3 1940 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1941 depends on FAULT_INJECTION
933e312e 1942 help
1ab8509a 1943 Provide fault-injection capability for alloc_pages().
933e312e 1944
2c739ced
AL
1945config FAULT_INJECTION_USERCOPY
1946 bool "Fault injection capability for usercopy functions"
1947 depends on FAULT_INJECTION
1948 help
1949 Provides fault-injection capability to inject failures
1950 in usercopy functions (copy_from_user(), get_user(), ...).
1951
c17bb495 1952config FAIL_MAKE_REQUEST
86327d19 1953 bool "Fault-injection capability for disk IO"
581d4e28 1954 depends on FAULT_INJECTION && BLOCK
c17bb495 1955 help
1ab8509a 1956 Provide fault-injection capability for disk IO.
c17bb495 1957
581d4e28 1958config FAIL_IO_TIMEOUT
f4d01439 1959 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1960 depends on FAULT_INJECTION && BLOCK
1961 help
1962 Provide fault-injection capability on end IO handling. This
1963 will make the block layer "forget" an interrupt as configured,
1964 thus exercising the error handling.
1965
1966 Only works with drivers that use the generic timeout handling,
9dbbc3b9 1967 for others it won't do anything.
581d4e28 1968
ab51fbab
DB
1969config FAIL_FUTEX
1970 bool "Fault-injection capability for futexes"
1971 select DEBUG_FS
1972 depends on FAULT_INJECTION && FUTEX
1973 help
1974 Provide fault-injection capability for futexes.
1975
f1b4bd06
MP
1976config FAULT_INJECTION_DEBUG_FS
1977 bool "Debugfs entries for fault-injection capabilities"
1978 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1979 help
1980 Enable configuration of fault-injection capabilities via debugfs.
1981
4b1a29a7
MH
1982config FAIL_FUNCTION
1983 bool "Fault-injection capability for functions"
1984 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1985 help
1986 Provide function-based fault-injection capability.
1987 This will allow you to override a specific function with a return
1988 with given return value. As a result, function caller will see
1989 an error value and have to handle it. This is useful to test the
1990 error handling in various subsystems.
1991
f1b4bd06
MP
1992config FAIL_MMC_REQUEST
1993 bool "Fault-injection capability for MMC IO"
1994 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1995 help
f1b4bd06
MP
1996 Provide fault-injection capability for MMC IO.
1997 This will make the mmc core return data errors. This is
1998 useful to test the error handling in the mmc block device
1999 and to test how the mmc host driver handles retries from
2000 the block device.
1df49008 2001
c782af25
CL
2002config FAIL_SUNRPC
2003 bool "Fault-injection capability for SunRPC"
2004 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2005 help
2006 Provide fault-injection capability for SunRPC and
2007 its consumers.
2008
1df49008
AM
2009config FAULT_INJECTION_STACKTRACE_FILTER
2010 bool "stacktrace filter for fault-injection capabilities"
2011 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2012 select STACKTRACE
7d37cb2c 2013 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1df49008
AM
2014 help
2015 Provide stacktrace filter for fault-injection capabilities
267c4025 2016
09a74952
CD
2017config ARCH_HAS_KCOV
2018 bool
cc3fa840 2019 help
09a74952
CD
2020 An architecture should select this when it can successfully
2021 build and run with CONFIG_KCOV. This typically requires
2022 disabling instrumentation for some early boot code.
cc3fa840 2023
09a74952
CD
2024config CC_HAS_SANCOV_TRACE_PC
2025 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 2026
cc3fa840 2027
09a74952
CD
2028config KCOV
2029 bool "Code coverage for fuzzing"
2030 depends on ARCH_HAS_KCOV
2031 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
22102f45 2032 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
bece04b5 2033 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
09a74952
CD
2034 select DEBUG_FS
2035 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
22102f45 2036 select OBJTOOL if HAVE_NOINSTR_HACK
09a74952
CD
2037 help
2038 KCOV exposes kernel code coverage information in a form suitable
2039 for coverage-guided fuzzing (randomized testing).
cc3fa840 2040
09a74952
CD
2041 If RANDOMIZE_BASE is enabled, PC values will not be stable across
2042 different machines and across reboots. If you need stable PC values,
2043 disable RANDOMIZE_BASE.
cc3fa840 2044
09a74952 2045 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 2046
09a74952
CD
2047config KCOV_ENABLE_COMPARISONS
2048 bool "Enable comparison operands collection by KCOV"
2049 depends on KCOV
2050 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2051 help
2052 KCOV also exposes operands of every comparison in the instrumented
2053 code along with operand sizes and PCs of the comparison instructions.
2054 These operands can be used by fuzzing engines to improve the quality
2055 of fuzzing coverage.
cc3fa840 2056
09a74952
CD
2057config KCOV_INSTRUMENT_ALL
2058 bool "Instrument all code by default"
2059 depends on KCOV
2060 default y
2061 help
2062 If you are doing generic system call fuzzing (like e.g. syzkaller),
2063 then you will want to instrument the whole kernel and you should
2064 say y here. If you are doing more targeted fuzzing (like e.g.
2065 filesystem fuzzing with AFL) then you will want to enable coverage
2066 for more specific subsets of files, and should say n here.
84bc809e 2067
5ff3b30a
AK
2068config KCOV_IRQ_AREA_SIZE
2069 hex "Size of interrupt coverage collection area in words"
2070 depends on KCOV
2071 default 0x40000
2072 help
2073 KCOV uses preallocated per-cpu areas to collect coverage from
2074 soft interrupts. This specifies the size of those areas in the
2075 number of unsigned long words.
2076
d3deafaa
VL
2077menuconfig RUNTIME_TESTING_MENU
2078 bool "Runtime Testing"
908009e8 2079 def_bool y
d3deafaa
VL
2080
2081if RUNTIME_TESTING_MENU
881c5149
DH
2082
2083config LKDTM
2084 tristate "Linux Kernel Dump Test Tool Module"
2085 depends on DEBUG_FS
881c5149
DH
2086 help
2087 This module enables testing of the different dumping mechanisms by
2088 inducing system failures at predefined crash points.
2089 If you don't need it: say N
2090 Choose M here to compile this code as a module. The module will be
2091 called lkdtm.
2092
2093 Documentation on how to use the module can be found in
10ffebbe 2094 Documentation/fault-injection/provoke-crashes.rst
881c5149 2095
d3c0ca49
SV
2096config CPUMASK_KUNIT_TEST
2097 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
c41e8866
SV
2098 depends on KUNIT
2099 default KUNIT_ALL_TESTS
2100 help
2101 Enable to turn on cpumask tests, running at boot or module load time.
2102
d3c0ca49
SV
2103 For more information on KUnit and unit tests in general, please refer
2104 to the KUnit documentation in Documentation/dev-tools/kunit/.
2105
c41e8866
SV
2106 If unsure, say N.
2107
881c5149 2108config TEST_LIST_SORT
ebd09577
DL
2109 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2110 depends on KUNIT
2111 default KUNIT_ALL_TESTS
881c5149
DH
2112 help
2113 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
2114 executed only once during system boot (so affects only boot time),
2115 or at module load time.
881c5149
DH
2116
2117 If unsure, say N.
2118
6e24628d
IR
2119config TEST_MIN_HEAP
2120 tristate "Min heap test"
2121 depends on DEBUG_KERNEL || m
2122 help
2123 Enable this to turn on min heap function tests. This test is
2124 executed only once during system boot (so affects only boot time),
2125 or at module load time.
2126
2127 If unsure, say N.
2128
c5adae95 2129config TEST_SORT
36f33b56
DL
2130 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2131 depends on KUNIT
2132 default KUNIT_ALL_TESTS
c5adae95 2133 help
5c4e6798
GU
2134 This option enables the self-test function of 'sort()' at boot,
2135 or at module load time.
c5adae95
KF
2136
2137 If unsure, say N.
2138
5086ea4b
MR
2139config TEST_DIV64
2140 tristate "64bit/32bit division and modulo test"
2141 depends on DEBUG_KERNEL || m
2142 help
2143 Enable this to turn on 'do_div()' function test. This test is
2144 executed only once during system boot (so affects only boot time),
2145 or at module load time.
2146
2147 If unsure, say N.
2148
881c5149 2149config KPROBES_SANITY_TEST
dcbb2ee2 2150 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
881c5149
DH
2151 depends on DEBUG_KERNEL
2152 depends on KPROBES
e44e81c5 2153 depends on KUNIT
de3db3f8 2154 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
dcbb2ee2 2155 default KUNIT_ALL_TESTS
881c5149
DH
2156 help
2157 This option provides for testing basic kprobes functionality on
5a6cf77f 2158 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
2159 verified for functionality.
2160
2161 Say N if you are unsure.
2162
f4616fab
MH
2163config FPROBE_SANITY_TEST
2164 bool "Self test for fprobe"
2165 depends on DEBUG_KERNEL
2166 depends on FPROBE
2167 depends on KUNIT=y
2168 help
2169 This option will enable testing the fprobe when the system boot.
2170 A series of tests are made to verify that the fprobe is functioning
2171 properly.
2172
2173 Say N if you are unsure.
2174
881c5149
DH
2175config BACKTRACE_SELF_TEST
2176 tristate "Self test for the backtrace code"
2177 depends on DEBUG_KERNEL
881c5149
DH
2178 help
2179 This option provides a kernel module that can be used to test
2180 the kernel stack backtrace code. This option is not useful
2181 for distributions or general kernels, but only for kernel
2182 developers working on architecture code.
2183
2184 Note that if you want to also test saved backtraces, you will
2185 have to enable STACKTRACE as well.
2186
2187 Say N if you are unsure.
2188
914a7b50
ED
2189config TEST_REF_TRACKER
2190 tristate "Self test for reference tracker"
2191 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2192 select REF_TRACKER
2193 help
2194 This option provides a kernel module performing tests
2195 using reference tracker infrastructure.
2196
2197 Say N if you are unsure.
2198
910a742d
ML
2199config RBTREE_TEST
2200 tristate "Red-Black tree test"
7c993e11 2201 depends on DEBUG_KERNEL
910a742d
ML
2202 help
2203 A benchmark measuring the performance of the rbtree library.
2204 Also includes rbtree invariant checks.
2205
4b4f3acc
FB
2206config REED_SOLOMON_TEST
2207 tristate "Reed-Solomon library test"
2208 depends on DEBUG_KERNEL || m
2209 select REED_SOLOMON
2210 select REED_SOLOMON_ENC16
2211 select REED_SOLOMON_DEC16
2212 help
2213 This option enables the self-test function of rslib at boot,
2214 or at module load time.
2215
2216 If unsure, say N.
2217
fff3fd8a
ML
2218config INTERVAL_TREE_TEST
2219 tristate "Interval tree test"
0f789b67 2220 depends on DEBUG_KERNEL
a88cc108 2221 select INTERVAL_TREE
fff3fd8a
ML
2222 help
2223 A benchmark measuring the performance of the interval tree library
2224
623fd807
GT
2225config PERCPU_TEST
2226 tristate "Per cpu operations test"
2227 depends on m && DEBUG_KERNEL
2228 help
2229 Enable this option to build test module which validates per-cpu
2230 operations.
2231
2232 If unsure, say N.
2233
881c5149 2234config ATOMIC64_SELFTEST
55ded955 2235 tristate "Perform an atomic64_t self-test"
881c5149 2236 help
55ded955
GU
2237 Enable this option to test the atomic64_t functions at boot or
2238 at module load time.
881c5149
DH
2239
2240 If unsure, say N.
2241
2242config ASYNC_RAID6_TEST
2243 tristate "Self test for hardware accelerated raid6 recovery"
2244 depends on ASYNC_RAID6_RECOV
2245 select ASYNC_MEMCPY
a7f7f624 2246 help
881c5149
DH
2247 This is a one-shot self test that permutes through the
2248 recovery of all the possible two disk failure scenarios for a
2249 N-disk array. Recovery is performed with the asynchronous
2250 raid6 recovery routines, and will optionally use an offload
2251 engine if one is available.
2252
2253 If unsure, say N.
2254
64d1d77a
AS
2255config TEST_HEXDUMP
2256 tristate "Test functions located in the hexdump module at runtime"
2257
b2ff70a0
MC
2258config STRING_SELFTEST
2259 tristate "Test string functions at runtime"
2260
881c5149
DH
2261config TEST_STRING_HELPERS
2262 tristate "Test functions located in the string_helpers module at runtime"
2263
2264config TEST_KSTRTOX
2265 tristate "Test kstrto*() family of functions at runtime"
2266
707cc728
RV
2267config TEST_PRINTF
2268 tristate "Test printf() family of functions at runtime"
2269
50f530e1
RF
2270config TEST_SCANF
2271 tristate "Test scanf() family of functions at runtime"
2272
5fd003f5
DD
2273config TEST_BITMAP
2274 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2275 help
2276 Enable this option to test the bitmap functions at boot.
2277
2278 If unsure, say N.
2279
cfaff0e5
AS
2280config TEST_UUID
2281 tristate "Test functions located in the uuid module at runtime"
2282
ad3d6c72
MW
2283config TEST_XARRAY
2284 tristate "Test the XArray code at runtime"
2285
120b1162 2286config TEST_MAPLE_TREE
845aad0a 2287 depends on DEBUG_KERNEL
120b1162
LH
2288 select DEBUG_MAPLE_TREE
2289 tristate "Test the Maple Tree code at runtime"
2290
7e1e7763 2291config TEST_RHASHTABLE
9d6dbe1b 2292 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2293 help
2294 Enable this option to test the rhashtable functions at boot.
2295
2296 If unsure, say N.
2297
8ab8ba38
MW
2298config TEST_IDA
2299 tristate "Perform selftest on IDA functions"
2300
44091d29
JP
2301config TEST_PARMAN
2302 tristate "Perform selftest on priority array manager"
44091d29
JP
2303 depends on PARMAN
2304 help
2305 Enable this option to test priority array manager on boot
2306 (or module load).
2307
2308 If unsure, say N.
2309
6aed82de
DL
2310config TEST_IRQ_TIMINGS
2311 bool "IRQ timings selftest"
2312 depends on IRQ_TIMINGS
2313 help
2314 Enable this option to test the irq timings code on boot.
2315
2316 If unsure, say N.
2317
8a6f0b47 2318config TEST_LKM
93e9ef83 2319 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2320 depends on m
2321 help
2322 This builds the "test_module" module that emits "Hello, world"
2323 on printk when loaded. It is designed to be used for basic
2324 evaluation of the module loading subsystem (for example when
2325 validating module verification). It lacks any extra dependencies,
2326 and will not normally be loaded by the system unless explicitly
2327 requested by name.
2328
2329 If unsure, say N.
2330
c348c163 2331config TEST_BITOPS
6af132f3 2332 tristate "Test module for compilation of bitops operations"
c348c163
JB
2333 depends on m
2334 help
2335 This builds the "test_bitops" module that is much like the
2336 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2337 set/clear_bit macros and get_count_order/long to make sure there are
2338 no compiler warnings from C=1 sparse checker or -Wextra
2339 compilations. It has no dependencies and doesn't run or load unless
2340 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2341
2342 If unsure, say N.
2343
3f21a6b7
URS
2344config TEST_VMALLOC
2345 tristate "Test module for stress/performance analysis of vmalloc allocator"
2346 default n
2347 depends on MMU
2348 depends on m
2349 help
2350 This builds the "test_vmalloc" module that should be used for
2351 stress and performance analysis. So, any new change for vmalloc
2352 subsystem can be evaluated from performance and stability point
2353 of view.
2354
2355 If unsure, say N.
2356
3e2a4c18
KC
2357config TEST_USER_COPY
2358 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2359 depends on m
2360 help
2361 This builds the "test_user_copy" module that runs sanity checks
2362 on the copy_to/from_user infrastructure, making sure basic
2363 user/kernel boundary testing is working. If it fails to load,
2364 a regression has been detected in the user/kernel memory boundary
2365 protections.
2366
2367 If unsure, say N.
2368
64a8946b
AS
2369config TEST_BPF
2370 tristate "Test BPF filter functionality"
98920ba6 2371 depends on m && NET
64a8946b
AS
2372 help
2373 This builds the "test_bpf" module that runs various test vectors
2374 against the BPF interpreter or BPF JIT compiler depending on the
2375 current setting. This is in particular useful for BPF JIT compiler
2376 development, but also to run regression tests against changes in
3c731eba
AS
2377 the interpreter code. It also enables test stubs for eBPF maps and
2378 verifier used by user space verifier testsuite.
64a8946b
AS
2379
2380 If unsure, say N.
2381
509e56b3
MB
2382config TEST_BLACKHOLE_DEV
2383 tristate "Test blackhole netdev functionality"
2384 depends on m && NET
2385 help
2386 This builds the "test_blackhole_dev" module that validates the
2387 data path through this blackhole netdev.
2388
2389 If unsure, say N.
2390
dceeb3e7 2391config FIND_BIT_BENCHMARK
4441fca0 2392 tristate "Test find_bit functions"
4441fca0
YN
2393 help
2394 This builds the "test_find_bit" module that measure find_*_bit()
2395 functions performance.
2396
2397 If unsure, say N.
2398
0a8adf58
KC
2399config TEST_FIRMWARE
2400 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2401 depends on FW_LOADER
2402 help
2403 This builds the "test_firmware" module that creates a userspace
2404 interface for testing firmware loading. This can be used to
2405 control the triggering of firmware loading without needing an
2406 actual firmware-using device. The contents can be rechecked by
2407 userspace.
2408
2409 If unsure, say N.
2410
9308f2f9
LR
2411config TEST_SYSCTL
2412 tristate "sysctl test driver"
9308f2f9
LR
2413 depends on PROC_SYSCTL
2414 help
2415 This builds the "test_sysctl" module. This driver enables to test the
2416 proc sysctl interfaces available to drivers safely without affecting
2417 production knobs which might alter system functionality.
2418
2419 If unsure, say N.
2420
d2585f51 2421config BITFIELD_KUNIT
dcbb2ee2 2422 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
d2585f51 2423 depends on KUNIT
dcbb2ee2 2424 default KUNIT_ALL_TESTS
d2585f51
VMI
2425 help
2426 Enable this option to test the bitfield functions at boot.
2427
2428 KUnit tests run during boot and output the results to the debug log
2429 in TAP format (http://testanything.org/). Only useful for kernel devs
2430 running the KUnit test harness, and not intended for inclusion into a
2431 production build.
2432
2433 For more information on KUnit and unit tests in general please refer
2434 to the KUnit documentation in Documentation/dev-tools/kunit/.
2435
2436 If unsure, say N.
2437
0acc968f
IB
2438config HASH_KUNIT_TEST
2439 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2440 depends on KUNIT
2441 default KUNIT_ALL_TESTS
2442 help
2443 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2444 integer (<linux/hash.h>) hash functions on boot.
2445
2446 KUnit tests run during boot and output the results to the debug log
2447 in TAP format (https://testanything.org/). Only useful for kernel devs
2448 running the KUnit test harness, and not intended for inclusion into a
2449 production build.
2450
2451 For more information on KUnit and unit tests in general please refer
2452 to the KUnit documentation in Documentation/dev-tools/kunit/.
2453
2454 This is intended to help people writing architecture-specific
2455 optimized versions. If unsure, say N.
2456
5df38ca6 2457config RESOURCE_KUNIT_TEST
dcbb2ee2 2458 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
5df38ca6 2459 depends on KUNIT
dcbb2ee2 2460 default KUNIT_ALL_TESTS
5df38ca6
AS
2461 help
2462 This builds the resource API unit test.
2463 Tests the logic of API provided by resource.c and ioport.h.
2464 For more information on KUnit and unit tests in general please refer
2465 to the KUnit documentation in Documentation/dev-tools/kunit/.
2466
2467 If unsure, say N.
2468
2cb80dbb 2469config SYSCTL_KUNIT_TEST
5f215aab 2470 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2471 depends on KUNIT
5f215aab 2472 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2473 help
2474 This builds the proc sysctl unit test, which runs on boot.
2475 Tests the API contract and implementation correctness of sysctl.
2476 For more information on KUnit and unit tests in general please refer
2477 to the KUnit documentation in Documentation/dev-tools/kunit/.
2478
2479 If unsure, say N.
2480
ea2dd7c0 2481config LIST_KUNIT_TEST
5f215aab 2482 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2483 depends on KUNIT
5f215aab 2484 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2485 help
2486 This builds the linked list KUnit test suite.
2487 It tests that the API and basic functionality of the list_head type
2488 and associated macros.
2489
2490 KUnit tests run during boot and output the results to the debug log
d89775fc 2491 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2492 running the KUnit test harness, and not intended for inclusion into a
2493 production build.
2494
2495 For more information on KUnit and unit tests in general please refer
2496 to the KUnit documentation in Documentation/dev-tools/kunit/.
2497
2498 If unsure, say N.
2499
33d599f0
MV
2500config LINEAR_RANGES_TEST
2501 tristate "KUnit test for linear_ranges"
2502 depends on KUNIT
2503 select LINEAR_RANGES
2504 help
2505 This builds the linear_ranges unit test, which runs on boot.
2506 Tests the linear_ranges logic correctness.
2507 For more information on KUnit and unit tests in general please refer
7546861a
AS
2508 to the KUnit documentation in Documentation/dev-tools/kunit/.
2509
2510 If unsure, say N.
2511
2512config CMDLINE_KUNIT_TEST
dcbb2ee2 2513 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
7546861a 2514 depends on KUNIT
dcbb2ee2 2515 default KUNIT_ALL_TESTS
7546861a
AS
2516 help
2517 This builds the cmdline API unit test.
2518 Tests the logic of API provided by cmdline.c.
2519 For more information on KUnit and unit tests in general please refer
33d599f0
MV
2520 to the KUnit documentation in Documentation/dev-tools/kunit/.
2521
2522 If unsure, say N.
2523
6d511020 2524config BITS_TEST
dcbb2ee2 2525 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
6d511020 2526 depends on KUNIT
dcbb2ee2 2527 default KUNIT_ALL_TESTS
6d511020
RF
2528 help
2529 This builds the bits unit test.
2530 Tests the logic of macros defined in bits.h.
2531 For more information on KUnit and unit tests in general please refer
2532 to the KUnit documentation in Documentation/dev-tools/kunit/.
2533
2534 If unsure, say N.
2535
1f9f78b1
OG
2536config SLUB_KUNIT_TEST
2537 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2538 depends on SLUB_DEBUG && KUNIT
2539 default KUNIT_ALL_TESTS
2540 help
2541 This builds SLUB allocator unit test.
2542 Tests SLUB cache debugging functionality.
2543 For more information on KUnit and unit tests in general please refer
2544 to the KUnit documentation in Documentation/dev-tools/kunit/.
2545
2546 If unsure, say N.
2547
b6c75c4a
TP
2548config RATIONAL_KUNIT_TEST
2549 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
8ba739ed 2550 depends on KUNIT && RATIONAL
b6c75c4a
TP
2551 default KUNIT_ALL_TESTS
2552 help
2553 This builds the rational math unit test.
2554 For more information on KUnit and unit tests in general please refer
2555 to the KUnit documentation in Documentation/dev-tools/kunit/.
2556
2557 If unsure, say N.
2558
bb95ebbe
KC
2559config MEMCPY_KUNIT_TEST
2560 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2561 depends on KUNIT
2562 default KUNIT_ALL_TESTS
2563 help
2564 Builds unit tests for memcpy(), memmove(), and memset() functions.
2565 For more information on KUnit and unit tests in general please refer
2566 to the KUnit documentation in Documentation/dev-tools/kunit/.
2567
2568 If unsure, say N.
2569
addbeea6
BVA
2570config IS_SIGNED_TYPE_KUNIT_TEST
2571 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2572 depends on KUNIT
2573 default KUNIT_ALL_TESTS
2574 help
2575 Builds unit tests for the is_signed_type() macro.
2576
2577 For more information on KUnit and unit tests in general please refer
2578 to the KUnit documentation in Documentation/dev-tools/kunit/.
2579
2580 If unsure, say N.
2581
617f55e2
KC
2582config OVERFLOW_KUNIT_TEST
2583 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2584 depends on KUNIT
2585 default KUNIT_ALL_TESTS
2586 help
2587 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2588 related functions.
2589
2590 For more information on KUnit and unit tests in general please refer
2591 to the KUnit documentation in Documentation/dev-tools/kunit/.
2592
2593 If unsure, say N.
2594
02788ebc
KC
2595config STACKINIT_KUNIT_TEST
2596 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2597 depends on KUNIT
2598 default KUNIT_ALL_TESTS
2599 help
2600 Test if the kernel is zero-initializing stack variables and
2601 padding. Coverage is controlled by compiler flags,
2602 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2603 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2604 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2605
875bfd52
KC
2606config FORTIFY_KUNIT_TEST
2607 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2608 depends on KUNIT && FORTIFY_SOURCE
2609 default KUNIT_ALL_TESTS
2610 help
2611 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2612 by the str*() and mem*() family of functions. For testing runtime
2613 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2614
724c299c
ME
2615config HW_BREAKPOINT_KUNIT_TEST
2616 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2617 depends on HAVE_HW_BREAKPOINT
2618 depends on KUNIT=y
2619 default KUNIT_ALL_TESTS
2620 help
2621 Tests for hw_breakpoint constraints accounting.
2622
2623 If unsure, say N.
2624
41eefc46
KC
2625config STRSCPY_KUNIT_TEST
2626 tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
2627 depends on KUNIT
2628 default KUNIT_ALL_TESTS
2629
fb3d88ab
KC
2630config SIPHASH_KUNIT_TEST
2631 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2632 depends on KUNIT
2633 default KUNIT_ALL_TESTS
2634 help
2635 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2636 functions on boot (or module load).
2637
2638 This is intended to help people writing architecture-specific
2639 optimized versions. If unsure, say N.
2640
e704f93a
DR
2641config TEST_UDELAY
2642 tristate "udelay test driver"
e704f93a
DR
2643 help
2644 This builds the "udelay_test" module that helps to make sure
2645 that udelay() is working properly.
2646
2647 If unsure, say N.
2648
2bf9e0ab
IM
2649config TEST_STATIC_KEYS
2650 tristate "Test static keys"
579e1acb
JB
2651 depends on m
2652 help
2bf9e0ab 2653 Test the static key interfaces.
579e1acb
JB
2654
2655 If unsure, say N.
2656
683263a5
JC
2657config TEST_DYNAMIC_DEBUG
2658 tristate "Test DYNAMIC_DEBUG"
2659 depends on DYNAMIC_DEBUG
2660 help
2661 This module registers a tracer callback to count enabled
2662 pr_debugs in a 'do_debugging' function, then alters their
2663 enablements, calls the function, and compares counts.
2664
2665 If unsure, say N.
2666
d9c6a72d
LR
2667config TEST_KMOD
2668 tristate "kmod stress tester"
d9c6a72d 2669 depends on m
d9c6a72d 2670 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2671 depends on BLOCK
bbd2e05f 2672 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
d9c6a72d
LR
2673 select TEST_LKM
2674 select XFS_FS
2675 select TUN
2676 select BTRFS_FS
2677 help
2678 Test the kernel's module loading mechanism: kmod. kmod implements
2679 support to load modules using the Linux kernel's usermode helper.
2680 This test provides a series of tests against kmod.
2681
2682 Although technically you can either build test_kmod as a module or
2683 into the kernel we disallow building it into the kernel since
2684 it stress tests request_module() and this will very likely cause
2685 some issues by taking over precious threads available from other
2686 module load requests, ultimately this could be fatal.
2687
2688 To run tests run:
2689
2690 tools/testing/selftests/kmod/kmod.sh --help
2691
2692 If unsure, say N.
2693
e4dace36
FF
2694config TEST_DEBUG_VIRTUAL
2695 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2696 depends on DEBUG_VIRTUAL
2697 help
2698 Test the kernel's ability to detect incorrect calls to
2699 virt_to_phys() done against the non-linear part of the
2700 kernel's virtual address map.
2701
2702 If unsure, say N.
2703
ce76d938
AS
2704config TEST_MEMCAT_P
2705 tristate "Test memcat_p() helper function"
2706 help
2707 Test the memcat_p() helper for correctly merging two
2708 pointer arrays together.
2709
2710 If unsure, say N.
2711
a2818ee4
JL
2712config TEST_LIVEPATCH
2713 tristate "Test livepatching"
2714 default n
bae05437 2715 depends on DYNAMIC_DEBUG
a2818ee4
JL
2716 depends on LIVEPATCH
2717 depends on m
2718 help
2719 Test kernel livepatching features for correctness. The tests will
2720 load test modules that will be livepatched in various scenarios.
2721
2722 To run all the livepatching tests:
2723
2724 make -C tools/testing/selftests TARGETS=livepatch run_tests
2725
2726 Alternatively, individual tests may be invoked:
2727
2728 tools/testing/selftests/livepatch/test-callbacks.sh
2729 tools/testing/selftests/livepatch/test-livepatch.sh
2730 tools/testing/selftests/livepatch/test-shadow-vars.sh
2731
2732 If unsure, say N.
2733
0a020d41
JP
2734config TEST_OBJAGG
2735 tristate "Perform selftest on object aggreration manager"
2736 default n
2737 depends on OBJAGG
2738 help
2739 Enable this option to test object aggregation manager on boot
2740 (or module load).
2741
5015a300
AP
2742config TEST_MEMINIT
2743 tristate "Test heap/page initialization"
2744 help
2745 Test if the kernel is zero-initializing heap and page allocations.
2746 This can be useful to test init_on_alloc and init_on_free features.
2747
2748 If unsure, say N.
2749
b2ef9f5a
RC
2750config TEST_HMM
2751 tristate "Test HMM (Heterogeneous Memory Management)"
2752 depends on TRANSPARENT_HUGEPAGE
2753 depends on DEVICE_PRIVATE
2754 select HMM_MIRROR
2755 select MMU_NOTIFIER
2756 help
2757 This is a pseudo device driver solely for testing HMM.
2758 Say M here if you want to build the HMM test module.
2759 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2760
2761 If unsure, say N.
2762
e320d301
MWO
2763config TEST_FREE_PAGES
2764 tristate "Test freeing pages"
2765 help
2766 Test that a memory leak does not occur due to a race between
2767 freeing a block of pages and a speculative page reference.
2768 Loading this module is safe if your kernel has the bug fixed.
2769 If the bug is not fixed, it will leak gigabytes of memory and
2770 probably OOM your system.
2771
4185b3b9
PA
2772config TEST_FPU
2773 tristate "Test floating point operations in kernel space"
2774 depends on X86 && !KCOV_INSTRUMENT_ALL
2775 help
2776 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2777 which will trigger a sequence of floating point operations. This is used
2778 for self-testing floating point control register setting in
2779 kernel_fpu_begin().
2780
2781 If unsure, say N.
2782
1253b9b8
PM
2783config TEST_CLOCKSOURCE_WATCHDOG
2784 tristate "Test clocksource watchdog in kernel space"
2785 depends on CLOCKSOURCE_WATCHDOG
2786 help
2787 Enable this option to create a kernel module that will trigger
2788 a test of the clocksource watchdog. This module may be loaded
2789 via modprobe or insmod in which case it will run upon being
2790 loaded, or it may be built in, in which case it will run
2791 shortly after boot.
2792
2793 If unsure, say N.
2794
d3deafaa 2795endif # RUNTIME_TESTING_MENU
cc3fa840 2796
dce44566
AK
2797config ARCH_USE_MEMTEST
2798 bool
2799 help
2800 An architecture should select this when it uses early_memtest()
2801 during boot process.
2802
cc3fa840
RD
2803config MEMTEST
2804 bool "Memtest"
dce44566 2805 depends on ARCH_USE_MEMTEST
a7f7f624 2806 help
cc3fa840 2807 This option adds a kernel parameter 'memtest', which allows memtest
dce44566 2808 to be set and executed.
cc3fa840
RD
2809 memtest=0, mean disabled; -- default
2810 memtest=1, mean do 1 test pattern;
2811 ...
2812 memtest=17, mean do 17 test patterns.
2813 If you are unsure how to answer this question, answer N.
2814
21266be9 2815
06ec64b8 2816
af9ca6f9
BB
2817config HYPERV_TESTING
2818 bool "Microsoft Hyper-V driver testing"
2819 default n
2820 depends on HYPERV && DEBUG_FS
2821 help
2822 Select this option to enable Hyper-V vmbus testing.
2823
045f6d79
CD
2824endmenu # "Kernel Testing and Coverage"
2825
2f7ab126
MO
2826menu "Rust hacking"
2827
2828config RUST_DEBUG_ASSERTIONS
2829 bool "Debug assertions"
2830 depends on RUST
2831 help
2832 Enables rustc's `-Cdebug-assertions` codegen option.
2833
2834 This flag lets you turn `cfg(debug_assertions)` conditional
2835 compilation on or off. This can be used to enable extra debugging
2836 code in development but not in production. For example, it controls
2837 the behavior of the standard library's `debug_assert!` macro.
2838
2839 Note that this will apply to all Rust code, including `core`.
2840
2841 If unsure, say N.
2842
2843config RUST_OVERFLOW_CHECKS
2844 bool "Overflow checks"
2845 default y
2846 depends on RUST
2847 help
2848 Enables rustc's `-Coverflow-checks` codegen option.
2849
2850 This flag allows you to control the behavior of runtime integer
2851 overflow. When overflow-checks are enabled, a Rust panic will occur
2852 on overflow.
2853
2854 Note that this will apply to all Rust code, including `core`.
2855
2856 If unsure, say Y.
2857
ecaa6ddf
GG
2858config RUST_BUILD_ASSERT_ALLOW
2859 bool "Allow unoptimized build-time assertions"
2860 depends on RUST
2861 help
2862 Controls how are `build_error!` and `build_assert!` handled during build.
2863
2864 If calls to them exist in the binary, it may indicate a violated invariant
2865 or that the optimizer failed to verify the invariant during compilation.
2866
2867 This should not happen, thus by default the build is aborted. However,
2868 as an escape hatch, you can choose Y here to ignore them during build
2869 and let the check be carried at runtime (with `panic!` being called if
2870 the check fails).
2871
2872 If unsure, say N.
2873
2f7ab126
MO
2874endmenu # "Rust"
2875
75442fb0
MCC
2876source "Documentation/Kconfig"
2877
06ec64b8 2878endmenu # Kernel hacking