objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"
[linux-2.6-block.git] / lib / Kconfig.debug
CommitLineData
ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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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
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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
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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
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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()
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61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option.
63
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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
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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
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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
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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
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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,
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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.
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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
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144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
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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
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177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information.
604ff0dc 179
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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
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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
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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
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209endmenu # "printk and dmesg options"
210
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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
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225menu "Compile-time checks and compiler options"
226
227config DEBUG_INFO
f9b3cd24 228 bool
6dfc0665 229 help
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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
234choice
235 prompt "Debug information"
236 depends on DEBUG_KERNEL
237 help
238 Selecting something other than "None" results in a kernel image
239 that will include debugging info resulting in a larger kernel image.
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240 This adds debug symbols to the kernel and modules (gcc -g), and
241 is needed if you intend to use kernel crashdump or binary object
242 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
6dfc0665 243
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244 Choose which version of DWARF debug info to emit. If unsure,
245 select "Toolchain default".
246
247config DEBUG_INFO_NONE
248 bool "Disable debug information"
249 help
250 Do not build the kernel with debugging information, which will
251 result in a faster and smaller build.
252
253config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
254 bool "Rely on the toolchain's implicit default DWARF version"
255 select DEBUG_INFO
256 help
257 The implicit default version of DWARF debug info produced by a
258 toolchain changes over time.
259
260 This can break consumers of the debug info that haven't upgraded to
261 support newer revisions, and prevent testing newer versions, but
262 those should be less common scenarios.
263
264config DEBUG_INFO_DWARF4
265 bool "Generate DWARF Version 4 debuginfo"
266 select DEBUG_INFO
267 help
268 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
269
270 If you have consumers of DWARF debug info that are not ready for
271 newer revisions of DWARF, you may wish to choose this or have your
272 config select this.
273
274config DEBUG_INFO_DWARF5
275 bool "Generate DWARF Version 5 debuginfo"
276 select DEBUG_INFO
277 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
278 help
279 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
280 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
281 draft features until 7.0), and gdb 8.0+.
282
283 Changes to the structure of debug info in Version 5 allow for around
284 15-18% savings in resulting image and debug info section sizes as
285 compared to DWARF Version 4. DWARF Version 5 standardizes previous
286 extensions such as accelerators for symbol indexing and the format
287 for fission (.dwo/.dwp) files. Users may not want to select this
288 config if they rely on tooling that has not yet been updated to
289 support DWARF Version 5.
290
291endchoice # "Debug information"
6dfc0665 292
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293if DEBUG_INFO
294
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295config DEBUG_INFO_REDUCED
296 bool "Reduce debugging information"
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297 help
298 If you say Y here gcc is instructed to generate less debugging
299 information for structure types. This means that tools that
300 need full debugging information (like kgdb or systemtap) won't
301 be happy. But if you merely need debugging information to
302 resolve line numbers there is no loss. Advantage is that
303 build directory object sizes shrink dramatically over a full
304 DEBUG_INFO build and compile times are reduced too.
305 Only works with newer gcc versions.
306
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307config DEBUG_INFO_COMPRESSED
308 bool "Compressed debugging information"
10e68b02 309 depends on $(cc-option,-gz=zlib)
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310 depends on $(ld-option,--compress-debug-sections=zlib)
311 help
312 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
313 5.0+, binutils 2.26+, and zlib.
314
315 Users of dpkg-deb via scripts/package/builddeb may find an increase in
316 size of their debug .deb packages with this config set, due to the
317 debug info being compressed with zlib, then the object files being
318 recompressed with a different compression scheme. But this is still
319 preferable to setting $KDEB_COMPRESS to "none" which would be even
320 larger.
321
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322config DEBUG_INFO_SPLIT
323 bool "Produce split debuginfo in .dwo files"
9d937444 324 depends on $(cc-option,-gsplit-dwarf)
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325 help
326 Generate debug info into separate .dwo files. This significantly
327 reduces the build directory size for builds with DEBUG_INFO,
328 because it stores the information only once on disk in .dwo
329 files instead of multiple times in object files and executables.
330 In addition the debug information is also compressed.
331
332 Requires recent gcc (4.7+) and recent gdb/binutils.
333 Any tool that packages or reads debug information would need
334 to know about the .dwo files and include them.
335 Incompatible with older versions of ccache.
336
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337config DEBUG_INFO_BTF
338 bool "Generate BTF typeinfo"
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339 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
340 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
d9847eb8 341 depends on BPF_SYSCALL
52deda95 342 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
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343 help
344 Generate deduplicated BTF type information from DWARF debug info.
345 Turning this on expects presence of pahole tool, which will convert
346 DWARF type info into equivalent deduplicated BTF type info.
347
5f9ae91f 348config PAHOLE_HAS_SPLIT_BTF
6323c813 349 def_bool PAHOLE_VERSION >= 119
5f9ae91f 350
7472d5a6 351config PAHOLE_HAS_BTF_TAG
6323c813 352 def_bool PAHOLE_VERSION >= 123
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353 depends on CC_IS_CLANG
354 help
355 Decide whether pahole emits btf_tag attributes (btf_type_tag and
356 btf_decl_tag) or not. Currently only clang compiler implements
357 these attributes, so make the config depend on CC_IS_CLANG.
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358
359config DEBUG_INFO_BTF_MODULES
360 def_bool y
361 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
362 help
363 Generate compact split BTF type information for kernel modules.
364
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365config MODULE_ALLOW_BTF_MISMATCH
366 bool "Allow loading modules with non-matching BTF type info"
367 depends on DEBUG_INFO_BTF_MODULES
368 help
369 For modules whose split BTF does not match vmlinux, load without
370 BTF rather than refusing to load. The default behavior with
371 module BTF enabled is to reject modules with such mismatches;
372 this option will still load module BTF where possible but ignore
373 it when a mismatch is found.
374
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375config GDB_SCRIPTS
376 bool "Provide GDB scripts for kernel debugging"
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377 help
378 This creates the required links to GDB helper scripts in the
379 build directory. If you load vmlinux into gdb, the helper
380 scripts will be automatically imported by gdb as well, and
381 additional functions are available to analyze a Linux kernel
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382 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
383 for further details.
3ee7b3fa 384
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385endif # DEBUG_INFO
386
35bb5b1e 387config FRAME_WARN
a83e4ca2 388 int "Warn for stack frames larger than"
35bb5b1e 389 range 0 8192
0e07f663 390 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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391 default 2048 if PARISC
392 default 1536 if (!64BIT && XTENSA)
393 default 1024 if !64BIT
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394 default 2048 if 64BIT
395 help
396 Tell gcc to warn at build time for stack frames larger than this.
397 Setting this too low will cause a lot of warnings.
398 Setting it to 0 disables the warning.
35bb5b1e 399
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400config STRIP_ASM_SYMS
401 bool "Strip assembler-generated symbols during link"
402 default n
403 help
404 Strip internal assembler-generated symbols during a link (symbols
405 that look like '.Lxxx') so they don't pollute the output of
406 get_wchan() and suchlike.
407
1873e870 408config READABLE_ASM
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409 bool "Generate readable assembler code"
410 depends on DEBUG_KERNEL
7d73c3e9 411 depends on CC_IS_GCC
bf4735a4 412 help
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413 Disable some compiler optimizations that tend to generate human unreadable
414 assembler output. This may make the kernel slightly slower, but it helps
415 to keep kernel developers who have to stare a lot at assembler listings
416 sane.
bf4735a4 417
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418config HEADERS_INSTALL
419 bool "Install uapi headers to usr/include"
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420 depends on !UML
421 help
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422 This option will install uapi headers (headers exported to user-space)
423 into the usr/include directory for use during the kernel build.
424 This is unneeded for building the kernel itself, but needed for some
425 user-space program samples. It is also needed by some features such
426 as uapi header sanity checks.
427
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428config DEBUG_SECTION_MISMATCH
429 bool "Enable full Section mismatch analysis"
7d73c3e9 430 depends on CC_IS_GCC
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431 help
432 The section mismatch analysis checks if there are illegal
433 references from one section to another section.
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434 During linktime or runtime, some sections are dropped;
435 any use of code/data previously in these sections would
91341d4b 436 most likely result in an oops.
e809ab01 437 In the code, functions and variables are annotated with
0db0628d 438 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 439 which results in the code/data being placed in specific sections.
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440 The section mismatch analysis is always performed after a full
441 kernel build, and enabling this option causes the following
b7dca6dd 442 additional step to occur:
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443 - Add the option -fno-inline-functions-called-once to gcc commands.
444 When inlining a function annotated with __init in a non-init
445 function, we would lose the section information and thus
91341d4b 446 the analysis would not catch the illegal reference.
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447 This option tells gcc to inline less (but it does result in
448 a larger kernel).
91341d4b 449
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450config SECTION_MISMATCH_WARN_ONLY
451 bool "Make section mismatch errors non-fatal"
452 default y
453 help
454 If you say N here, the build process will fail if there are any
455 section mismatch, instead of just throwing warnings.
456
457 If unsure, say Y.
458
cf536e18 459config DEBUG_FORCE_FUNCTION_ALIGN_64B
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460 bool "Force all function address 64B aligned"
461 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
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462 help
463 There are cases that a commit from one domain changes the function
464 address alignment of other domains, and cause magic performance
465 bump (regression or improvement). Enable this option will help to
466 verify if the bump is caused by function alignment changes, while
467 it will slightly increase the kernel size and affect icache usage.
468
469 It is mainly for debug and performance tuning use.
470
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471#
472# Select this config option from the architecture Kconfig, if it
473# is preferred to always offer frame pointers as a config
474# option on the architecture (regardless of KERNEL_DEBUG):
475#
476config ARCH_WANT_FRAME_POINTERS
477 bool
f346f4b3 478
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479config FRAME_POINTER
480 bool "Compile the kernel with frame pointers"
a687a533 481 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 482 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 483 help
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484 If you say Y here the resulting kernel image will be slightly
485 larger and slower, but it gives very useful debugging information
486 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 487
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488config OBJTOOL
489 bool
490
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491config STACK_VALIDATION
492 bool "Compile-time stack metadata validation"
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493 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
494 select OBJTOOL
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495 default n
496 help
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497 Validate frame pointer rules at compile-time. This helps ensure that
498 runtime stack traces are more reliable.
ee9f8fce 499
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500 For more information, see
501 tools/objtool/Documentation/stack-validation.txt.
502
0f620cef 503config NOINSTR_VALIDATION
6804c1af 504 bool
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505 depends on HAVE_OBJTOOL && DEBUG_ENTRY
506 select OBJTOOL
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507 default y
508
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509config VMLINUX_MAP
510 bool "Generate vmlinux.map file when linking"
511 depends on EXPERT
512 help
513 Selecting this option will pass "-Map=vmlinux.map" to ld
514 when linking vmlinux. That file can be useful for verifying
515 and debugging magic section games, and for seeing which
516 pieces of code get eliminated with
517 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
518
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519config DEBUG_FORCE_WEAK_PER_CPU
520 bool "Force weak per-cpu definitions"
521 depends on DEBUG_KERNEL
8446f1d3 522 help
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523 s390 and alpha require percpu variables in modules to be
524 defined weak to work around addressing range issue which
525 puts the following two restrictions on percpu variable
526 definitions.
8446f1d3 527
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528 1. percpu symbols must be unique whether static or not
529 2. percpu variables can't be defined inside a function
8446f1d3 530
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531 To ensure that generic code follows the above rules, this
532 option forces all percpu variables to be defined as weak.
5f329089 533
6dfc0665 534endmenu # "Compiler options"
8446f1d3 535
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536menu "Generic Kernel Debugging Instruments"
537
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538config MAGIC_SYSRQ
539 bool "Magic SysRq key"
540 depends on !UML
541 help
542 If you say Y here, you will have some control over the system even
543 if the system crashes for example during kernel debugging (e.g., you
544 will be able to flush the buffer cache to disk, reboot the system
545 immediately or dump some status information). This is accomplished
546 by pressing various keys while holding SysRq (Alt+PrintScreen). It
547 also works on a serial console (on PC hardware at least), if you
548 send a BREAK and then within 5 seconds a command keypress. The
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549 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
550 Don't say Y unless you really know what this hack does.
8446f1d3 551
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552config MAGIC_SYSRQ_DEFAULT_ENABLE
553 hex "Enable magic SysRq key functions by default"
554 depends on MAGIC_SYSRQ
555 default 0x1
556 help
557 Specifies which SysRq key functions are enabled by default.
558 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 559 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 560
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561config MAGIC_SYSRQ_SERIAL
562 bool "Enable magic SysRq key over serial"
563 depends on MAGIC_SYSRQ
564 default y
565 help
566 Many embedded boards have a disconnected TTL level serial which can
567 generate some garbage that can lead to spurious false sysrq detects.
568 This option allows you to decide whether you want to enable the
569 magic SysRq key.
570
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571config MAGIC_SYSRQ_SERIAL_SEQUENCE
572 string "Char sequence that enables magic SysRq over serial"
573 depends on MAGIC_SYSRQ_SERIAL
574 default ""
575 help
576 Specifies a sequence of characters that can follow BREAK to enable
577 SysRq on a serial console.
578
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579 If unsure, leave an empty string and the option will not be enabled.
580
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581config DEBUG_FS
582 bool "Debug Filesystem"
583 help
584 debugfs is a virtual file system that kernel developers use to put
585 debugging files into. Enable this option to be able to read and
586 write to these files.
587
588 For detailed documentation on the debugfs API, see
589 Documentation/filesystems/.
590
591 If unsure, say N.
592
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593choice
594 prompt "Debugfs default access"
595 depends on DEBUG_FS
596 default DEBUG_FS_ALLOW_ALL
597 help
598 This selects the default access restrictions for debugfs.
599 It can be overridden with kernel command line option
600 debugfs=[on,no-mount,off]. The restrictions apply for API access
601 and filesystem registration.
602
603config DEBUG_FS_ALLOW_ALL
604 bool "Access normal"
605 help
606 No restrictions apply. Both API and filesystem registration
607 is on. This is the normal default operation.
608
609config DEBUG_FS_DISALLOW_MOUNT
610 bool "Do not register debugfs as filesystem"
611 help
612 The API is open but filesystem is not loaded. Clients can still do
613 their work and read with debug tools that do not need
614 debugfs filesystem.
615
616config DEBUG_FS_ALLOW_NONE
617 bool "No access"
618 help
619 Access is off. Clients get -PERM when trying to create nodes in
620 debugfs tree and debugfs is not registered as a filesystem.
621 Client can then back-off or continue without debugfs access.
622
623endchoice
624
6210b640 625source "lib/Kconfig.kgdb"
6210b640 626source "lib/Kconfig.ubsan"
2645d432 627source "lib/Kconfig.kcsan"
6210b640
CD
628
629endmenu
630
4d92b95f
ED
631menu "Networking Debugging"
632
633source "net/Kconfig.debug"
634
635endmenu # "Networking Debugging"
c66d7a27 636
0610c8a8 637menu "Memory Debugging"
fef2c9bc 638
8636a1f9 639source "mm/Kconfig.debug"
fef2c9bc 640
0610c8a8
DH
641config DEBUG_OBJECTS
642 bool "Debug object operations"
643 depends on DEBUG_KERNEL
9c44bc03 644 help
0610c8a8
DH
645 If you say Y here, additional code will be inserted into the
646 kernel to track the life time of various objects and validate
647 the operations on those objects.
9c44bc03 648
0610c8a8
DH
649config DEBUG_OBJECTS_SELFTEST
650 bool "Debug objects selftest"
651 depends on DEBUG_OBJECTS
652 help
653 This enables the selftest of the object debug code.
9c44bc03 654
0610c8a8
DH
655config DEBUG_OBJECTS_FREE
656 bool "Debug objects in freed memory"
657 depends on DEBUG_OBJECTS
658 help
659 This enables checks whether a k/v free operation frees an area
660 which contains an object which has not been deactivated
661 properly. This can make kmalloc/kfree-intensive workloads
662 much slower.
3ac7fe5a 663
c6f3a97f
TG
664config DEBUG_OBJECTS_TIMERS
665 bool "Debug timer objects"
666 depends on DEBUG_OBJECTS
667 help
668 If you say Y here, additional code will be inserted into the
669 timer routines to track the life time of timer objects and
670 validate the timer operations.
671
dc186ad7
TG
672config DEBUG_OBJECTS_WORK
673 bool "Debug work objects"
674 depends on DEBUG_OBJECTS
675 help
676 If you say Y here, additional code will be inserted into the
677 work queue routines to track the life time of work objects and
678 validate the work operations.
679
551d55a9
MD
680config DEBUG_OBJECTS_RCU_HEAD
681 bool "Debug RCU callbacks objects"
fc2ecf7e 682 depends on DEBUG_OBJECTS
551d55a9
MD
683 help
684 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
685
e2852ae8
TH
686config DEBUG_OBJECTS_PERCPU_COUNTER
687 bool "Debug percpu counter objects"
688 depends on DEBUG_OBJECTS
689 help
690 If you say Y here, additional code will be inserted into the
691 percpu counter routines to track the life time of percpu counter
692 objects and validate the percpu counter operations.
693
3ae70205
IM
694config DEBUG_OBJECTS_ENABLE_DEFAULT
695 int "debug_objects bootup default value (0-1)"
68d4b3df
KK
696 range 0 1
697 default "1"
698 depends on DEBUG_OBJECTS
699 help
700 Debug objects boot parameter default value
3ae70205 701
1da177e4 702config DEBUG_SLAB
4a2f0acf 703 bool "Debug slab memory allocations"
4675ff05 704 depends on DEBUG_KERNEL && SLAB
1da177e4
LT
705 help
706 Say Y here to have the kernel do limited verification on memory
707 allocation as well as poisoning memory on free to catch use of freed
708 memory. This can make kmalloc/kfree-intensive workloads much slower.
709
f0630fff
CL
710config SLUB_DEBUG_ON
711 bool "SLUB debugging on by default"
4675ff05 712 depends on SLUB && SLUB_DEBUG
f0630fff
CL
713 default n
714 help
715 Boot with debugging on by default. SLUB boots by default with
716 the runtime debug capabilities switched off. Enabling this is
717 equivalent to specifying the "slub_debug" parameter on boot.
718 There is no support for more fine grained debug control like
719 possible with slub_debug=xxx. SLUB debugging may be switched
720 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
721 "slub_debug=-".
722
8ff12cfc
CL
723config SLUB_STATS
724 default n
725 bool "Enable SLUB performance statistics"
ab4d5ed5 726 depends on SLUB && SYSFS
8ff12cfc
CL
727 help
728 SLUB statistics are useful to debug SLUBs allocation behavior in
729 order find ways to optimize the allocator. This should never be
730 enabled for production use since keeping statistics slows down
731 the allocator by a few percentage points. The slabinfo command
732 supports the determination of the most active slabs to figure
733 out which slabs are relevant to a particular load.
734 Try running: slabinfo -DA
735
b69ec42b
CM
736config HAVE_DEBUG_KMEMLEAK
737 bool
738
3bba00d7
CM
739config DEBUG_KMEMLEAK
740 bool "Kernel memory leak detector"
525c1f92 741 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 742 select DEBUG_FS
3bba00d7
CM
743 select STACKTRACE if STACKTRACE_SUPPORT
744 select KALLSYMS
b60e26a2 745 select CRC32
3bba00d7
CM
746 help
747 Say Y here if you want to enable the memory leak
748 detector. The memory allocation/freeing is traced in a way
749 similar to the Boehm's conservative garbage collector, the
750 difference being that the orphan objects are not freed but
751 only shown in /sys/kernel/debug/kmemleak. Enabling this
752 feature will introduce an overhead to memory
700199b0 753 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
754 details.
755
0610c8a8
DH
756 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
757 of finding leaks due to the slab objects poisoning.
758
759 In order to access the kmemleak file, debugfs needs to be
760 mounted (usually at /sys/kernel/debug).
761
c5665868
CM
762config DEBUG_KMEMLEAK_MEM_POOL_SIZE
763 int "Kmemleak memory pool size"
0610c8a8 764 depends on DEBUG_KMEMLEAK
c59180ae 765 range 200 1000000
b751c52b 766 default 16000
0610c8a8
DH
767 help
768 Kmemleak must track all the memory allocations to avoid
769 reporting false positives. Since memory may be allocated or
c5665868
CM
770 freed before kmemleak is fully initialised, use a static pool
771 of metadata objects to track such callbacks. After kmemleak is
772 fully initialised, this memory pool acts as an emergency one
773 if slab allocations fail.
0610c8a8
DH
774
775config DEBUG_KMEMLEAK_TEST
776 tristate "Simple test for the kernel memory leak detector"
777 depends on DEBUG_KMEMLEAK && m
778 help
779 This option enables a module that explicitly leaks memory.
780
781 If unsure, say N.
782
783config DEBUG_KMEMLEAK_DEFAULT_OFF
784 bool "Default kmemleak to off"
785 depends on DEBUG_KMEMLEAK
786 help
787 Say Y here to disable kmemleak by default. It can then be enabled
788 on the command line via kmemleak=on.
789
d53ce042
SK
790config DEBUG_KMEMLEAK_AUTO_SCAN
791 bool "Enable kmemleak auto scan thread on boot up"
792 default y
793 depends on DEBUG_KMEMLEAK
794 help
795 Depending on the cpu, kmemleak scan may be cpu intensive and can
796 stall user tasks at times. This option enables/disables automatic
797 kmemleak scan at boot up.
798
799 Say N here to disable kmemleak auto scan thread to stop automatic
800 scanning. Disabling this option disables automatic reporting of
801 memory leaks.
802
803 If unsure, say Y.
804
0610c8a8
DH
805config DEBUG_STACK_USAGE
806 bool "Stack utilization instrumentation"
6c31da34 807 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
808 help
809 Enables the display of the minimum amount of free stack which each
810 task has ever had available in the sysrq-T and sysrq-P debug output.
811
812 This option will slow down process creation somewhat.
813
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CD
814config SCHED_STACK_END_CHECK
815 bool "Detect stack corruption on calls to schedule()"
816 depends on DEBUG_KERNEL
817 default n
818 help
819 This option checks for a stack overrun on calls to schedule().
820 If the stack end location is found to be over written always panic as
821 the content of the corrupted region can no longer be trusted.
822 This is to ensure no erroneous behaviour occurs which could result in
823 data corruption or a sporadic crash at a later stage once the region
824 is examined. The runtime overhead introduced is minimal.
825
399145f9
AK
826config ARCH_HAS_DEBUG_VM_PGTABLE
827 bool
828 help
829 An architecture should select this when it can successfully
830 build and run DEBUG_VM_PGTABLE.
831
0610c8a8
DH
832config DEBUG_VM
833 bool "Debug VM"
834 depends on DEBUG_KERNEL
835 help
836 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 837 that may impact performance.
0610c8a8
DH
838
839 If unsure, say N.
840
4f115147
DB
841config DEBUG_VM_VMACACHE
842 bool "Debug VMA caching"
843 depends on DEBUG_VM
844 help
845 Enable this to turn on VMA caching debug information. Doing so
846 can cause significant overhead, so only enable it in non-production
847 environments.
848
849 If unsure, say N.
850
0610c8a8
DH
851config DEBUG_VM_RB
852 bool "Debug VM red-black trees"
853 depends on DEBUG_VM
854 help
a663dad6 855 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
856
857 If unsure, say N.
858
95ad9755
KS
859config DEBUG_VM_PGFLAGS
860 bool "Debug page-flags operations"
861 depends on DEBUG_VM
862 help
863 Enables extra validation on page flags operations.
864
865 If unsure, say N.
866
399145f9
AK
867config DEBUG_VM_PGTABLE
868 bool "Debug arch page table for semantics compliance"
869 depends on MMU
870 depends on ARCH_HAS_DEBUG_VM_PGTABLE
871 default y if DEBUG_VM
872 help
873 This option provides a debug method which can be used to test
874 architecture page table helper functions on various platforms in
875 verifying if they comply with expected generic MM semantics. This
876 will help architecture code in making sure that any changes or
877 new additions of these helpers still conform to expected
878 semantics of the generic MM. Platforms will have to opt in for
879 this through ARCH_HAS_DEBUG_VM_PGTABLE.
880
881 If unsure, say N.
882
fa5b6ec9
LA
883config ARCH_HAS_DEBUG_VIRTUAL
884 bool
885
0610c8a8
DH
886config DEBUG_VIRTUAL
887 bool "Debug VM translations"
fa5b6ec9 888 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
889 help
890 Enable some costly sanity checks in virtual to page code. This can
891 catch mistakes with virt_to_page() and friends.
892
893 If unsure, say N.
894
895config DEBUG_NOMMU_REGIONS
896 bool "Debug the global anon/private NOMMU mapping region tree"
897 depends on DEBUG_KERNEL && !MMU
898 help
899 This option causes the global tree of anonymous and private mapping
900 regions to be regularly checked for invalid topology.
901
902config DEBUG_MEMORY_INIT
903 bool "Debug memory initialisation" if EXPERT
904 default !EXPERT
905 help
906 Enable this for additional checks during memory initialisation.
907 The sanity checks verify aspects of the VM such as the memory model
908 and other information provided by the architecture. Verbose
909 information will be printed at KERN_DEBUG loglevel depending
910 on the mminit_loglevel= command-line option.
911
912 If unsure, say Y
913
914config MEMORY_NOTIFIER_ERROR_INJECT
915 tristate "Memory hotplug notifier error injection module"
50f9481e 916 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
0610c8a8
DH
917 help
918 This option provides the ability to inject artificial errors to
919 memory hotplug notifier chain callbacks. It is controlled through
920 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
921
922 If the notifier call chain should be failed with some events
923 notified, write the error code to "actions/<notifier event>/error".
924
925 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
926
927 # cd /sys/kernel/debug/notifier-error-inject/memory
928 # echo -12 > actions/MEM_GOING_OFFLINE/error
929 # echo offline > /sys/devices/system/memory/memoryXXX/state
930 bash: echo: write error: Cannot allocate memory
931
932 To compile this code as a module, choose M here: the module will
933 be called memory-notifier-error-inject.
934
935 If unsure, say N.
936
937config DEBUG_PER_CPU_MAPS
938 bool "Debug access to per_cpu maps"
939 depends on DEBUG_KERNEL
940 depends on SMP
941 help
942 Say Y to verify that the per_cpu map being accessed has
943 been set up. This adds a fair amount of code to kernel memory
944 and decreases performance.
945
946 Say N if unsure.
947
6e799cb6
TG
948config DEBUG_KMAP_LOCAL
949 bool "Debug kmap_local temporary mappings"
950 depends on DEBUG_KERNEL && KMAP_LOCAL
951 help
952 This option enables additional error checking for the kmap_local
953 infrastructure. Disable for production use.
954
0e91a0c6
TG
955config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
956 bool
957
958config DEBUG_KMAP_LOCAL_FORCE_MAP
959 bool "Enforce kmap_local temporary mappings"
960 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
961 select KMAP_LOCAL
962 select DEBUG_KMAP_LOCAL
963 help
964 This option enforces temporary mappings through the kmap_local
965 mechanism for non-highmem pages and on non-highmem systems.
966 Disable this for production systems!
967
0610c8a8
DH
968config DEBUG_HIGHMEM
969 bool "Highmem debugging"
970 depends on DEBUG_KERNEL && HIGHMEM
0e91a0c6 971 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
6e799cb6 972 select DEBUG_KMAP_LOCAL
0610c8a8 973 help
b1357c9f
GU
974 This option enables additional error checking for high memory
975 systems. Disable for production systems.
0610c8a8
DH
976
977config HAVE_DEBUG_STACKOVERFLOW
978 bool
979
980config DEBUG_STACKOVERFLOW
981 bool "Check for stack overflows"
982 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 983 help
0610c8a8 984 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 985 and exception stacks (if your architecture uses them). This
0610c8a8
DH
986 option will show detailed messages if free stack space drops
987 below a certain limit.
988
989 These kinds of bugs usually occur when call-chains in the
990 kernel get too deep, especially when interrupts are
991 involved.
992
993 Use this in cases where you see apparently random memory
994 corruption, especially if it appears in 'struct thread_info'
995
996 If in doubt, say "N".
997
0b24becc 998source "lib/Kconfig.kasan"
0ce20dd8 999source "lib/Kconfig.kfence"
0b24becc 1000
0610c8a8
DH
1001endmenu # "Memory Debugging"
1002
a304e1b8
DW
1003config DEBUG_SHIRQ
1004 bool "Debug shared IRQ handlers"
0244ad00 1005 depends on DEBUG_KERNEL
a304e1b8 1006 help
0a2fae2a
WS
1007 Enable this to generate a spurious interrupt just before a shared
1008 interrupt handler is deregistered (generating one when registering
1009 is currently disabled). Drivers need to handle this correctly. Some
1010 don't and need to be caught.
a304e1b8 1011
f43a289d
CD
1012menu "Debug Oops, Lockups and Hangs"
1013
1014config PANIC_ON_OOPS
1015 bool "Panic on Oops"
1016 help
1017 Say Y here to enable the kernel to panic when it oopses. This
1018 has the same effect as setting oops=panic on the kernel command
1019 line.
1020
1021 This feature is useful to ensure that the kernel does not do
1022 anything erroneous after an oops which could result in data
1023 corruption or other issues.
1024
1025 Say N if unsure.
1026
1027config PANIC_ON_OOPS_VALUE
1028 int
1029 range 0 1
1030 default 0 if !PANIC_ON_OOPS
1031 default 1 if PANIC_ON_OOPS
1032
1033config PANIC_TIMEOUT
1034 int "panic timeout"
1035 default 0
1036 help
9d5b134f 1037 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
1038 the kernel panics. If n = 0, then we wait forever. A timeout
1039 value n > 0 will wait n seconds before rebooting, while a timeout
1040 value n < 0 will reboot immediately.
92aef8fb 1041
58687acb 1042config LOCKUP_DETECTOR
05a4a952
NP
1043 bool
1044
1045config SOFTLOCKUP_DETECTOR
1046 bool "Detect Soft Lockups"
dea20a3f 1047 depends on DEBUG_KERNEL && !S390
05a4a952 1048 select LOCKUP_DETECTOR
8446f1d3 1049 help
58687acb 1050 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 1051 soft lockups.
58687acb
DZ
1052
1053 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 1054 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
1055 chance to run. The current stack trace is displayed upon
1056 detection and the system will stay locked up.
8446f1d3 1057
5f00ae0d
RD
1058config BOOTPARAM_SOFTLOCKUP_PANIC
1059 bool "Panic (Reboot) On Soft Lockups"
1060 depends on SOFTLOCKUP_DETECTOR
1061 help
1062 Say Y here to enable the kernel to panic on "soft lockups",
1063 which are bugs that cause the kernel to loop in kernel
1064 mode for more than 20 seconds (configurable using the watchdog_thresh
1065 sysctl), without giving other tasks a chance to run.
1066
1067 The panic can be used in combination with panic_timeout,
1068 to cause the system to reboot automatically after a
1069 lockup has been detected. This feature is useful for
1070 high-availability systems that have uptime guarantees and
1071 where a lockup must be resolved ASAP.
1072
1073 Say N if unsure.
1074
1075config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
1076 int
1077 depends on SOFTLOCKUP_DETECTOR
1078 range 0 1
1079 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
1080 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
1081
05a4a952
NP
1082config HARDLOCKUP_DETECTOR_PERF
1083 bool
1084 select SOFTLOCKUP_DETECTOR
1085
7edaeb68
TG
1086#
1087# Enables a timestamp based low pass filter to compensate for perf based
1088# hard lockup detection which runs too fast due to turbo modes.
1089#
1090config HARDLOCKUP_CHECK_TIMESTAMP
1091 bool
1092
05a4a952
NP
1093#
1094# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1095# lockup detector rather than the perf based detector.
1096#
1097config HARDLOCKUP_DETECTOR
1098 bool "Detect Hard Lockups"
1099 depends on DEBUG_KERNEL && !S390
1100 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1101 select LOCKUP_DETECTOR
1102 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
05a4a952
NP
1103 help
1104 Say Y here to enable the kernel to act as a watchdog to detect
1105 hard lockups.
1106
58687acb 1107 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 1108 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
1109 chance to run. The current stack trace is displayed upon detection
1110 and the system will stay locked up.
8446f1d3 1111
fef2c9bc
DZ
1112config BOOTPARAM_HARDLOCKUP_PANIC
1113 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 1114 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1115 help
1116 Say Y here to enable the kernel to panic on "hard lockups",
1117 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1118 mode with interrupts disabled for more than 10 seconds (configurable
1119 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1120
1121 Say N if unsure.
1122
1123config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1124 int
8f1f66ed 1125 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1126 range 0 1
1127 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1128 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1129
e162b39a
MSB
1130config DETECT_HUNG_TASK
1131 bool "Detect Hung Tasks"
1132 depends on DEBUG_KERNEL
05a4a952 1133 default SOFTLOCKUP_DETECTOR
e162b39a 1134 help
0610c8a8
DH
1135 Say Y here to enable the kernel to detect "hung tasks",
1136 which are bugs that cause the task to be stuck in
96b03ab8 1137 uninterruptible "D" state indefinitely.
1da177e4 1138
0610c8a8
DH
1139 When a hung task is detected, the kernel will print the
1140 current stack trace (which you should report), but the
1141 task will stay in uninterruptible state. If lockdep is
1142 enabled then all held locks will also be reported. This
1143 feature has negligible overhead.
871751e2 1144
0610c8a8
DH
1145config DEFAULT_HUNG_TASK_TIMEOUT
1146 int "Default timeout for hung task detection (in seconds)"
1147 depends on DETECT_HUNG_TASK
1148 default 120
f0630fff 1149 help
0610c8a8
DH
1150 This option controls the default timeout (in seconds) used
1151 to determine when a task has become non-responsive and should
1152 be considered hung.
f0630fff 1153
0610c8a8
DH
1154 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1155 sysctl or by writing a value to
1156 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1157
0610c8a8
DH
1158 A timeout of 0 disables the check. The default is two minutes.
1159 Keeping the default should be fine in most cases.
b69ec42b 1160
0610c8a8
DH
1161config BOOTPARAM_HUNG_TASK_PANIC
1162 bool "Panic (Reboot) On Hung Tasks"
1163 depends on DETECT_HUNG_TASK
3bba00d7 1164 help
0610c8a8
DH
1165 Say Y here to enable the kernel to panic on "hung tasks",
1166 which are bugs that cause the kernel to leave a task stuck
1167 in uninterruptible "D" state.
3bba00d7 1168
0610c8a8
DH
1169 The panic can be used in combination with panic_timeout,
1170 to cause the system to reboot automatically after a
1171 hung task has been detected. This feature is useful for
1172 high-availability systems that have uptime guarantees and
1173 where a hung tasks must be resolved ASAP.
bf96d1e3 1174
0610c8a8 1175 Say N if unsure.
bf96d1e3 1176
0610c8a8
DH
1177config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1178 int
1179 depends on DETECT_HUNG_TASK
1180 range 0 1
1181 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1182 default 1 if BOOTPARAM_HUNG_TASK_PANIC
3bba00d7 1183
82607adc
TH
1184config WQ_WATCHDOG
1185 bool "Detect Workqueue Stalls"
1186 depends on DEBUG_KERNEL
1187 help
1188 Say Y here to enable stall detection on workqueues. If a
1189 worker pool doesn't make forward progress on a pending work
1190 item for over a given amount of time, 30s by default, a
1191 warning message is printed along with dump of workqueue
1192 state. This can be configured through kernel parameter
1193 "workqueue.watchdog_thresh" and its sysfs counterpart.
1194
30428ef5
KK
1195config TEST_LOCKUP
1196 tristate "Test module to generate lockups"
63646bc9 1197 depends on m
30428ef5
KK
1198 help
1199 This builds the "test_lockup" module that helps to make sure
1200 that watchdogs and lockup detectors are working properly.
1201
1202 Depending on module parameters it could emulate soft or hard
1203 lockup, "hung task", or locking arbitrary lock for a long time.
1204 Also it could generate series of lockups with cooling-down periods.
1205
1206 If unsure, say N.
1207
92aef8fb
DH
1208endmenu # "Debug lockups and hangs"
1209
ebebdd09 1210menu "Scheduler Debugging"
5800dc3c 1211
0610c8a8
DH
1212config SCHED_DEBUG
1213 bool "Collect scheduler debugging info"
1214 depends on DEBUG_KERNEL && PROC_FS
1215 default y
0822ee4a 1216 help
0610c8a8
DH
1217 If you say Y here, the /proc/sched_debug file will be provided
1218 that can help debug the scheduler. The runtime overhead of this
1219 option is minimal.
0822ee4a 1220
f6db8347
NR
1221config SCHED_INFO
1222 bool
1223 default n
1224
0610c8a8
DH
1225config SCHEDSTATS
1226 bool "Collect scheduler statistics"
1227 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1228 select SCHED_INFO
0610c8a8
DH
1229 help
1230 If you say Y here, additional code will be inserted into the
1231 scheduler and related routines to collect statistics about
1232 scheduler behavior and provide them in /proc/schedstat. These
1233 stats may be useful for both tuning and debugging the scheduler
1234 If you aren't debugging the scheduler or trying to tune a specific
1235 application, you can say N to avoid the very slight overhead
1236 this adds.
0822ee4a 1237
ebebdd09 1238endmenu
0d9e2632 1239
3c17ad19
JS
1240config DEBUG_TIMEKEEPING
1241 bool "Enable extra timekeeping sanity checking"
1242 help
1243 This option will enable additional timekeeping sanity checks
1244 which may be helpful when diagnosing issues where timekeeping
1245 problems are suspected.
1246
1247 This may include checks in the timekeeping hotpaths, so this
1248 option may have a (very small) performance impact to some
1249 workloads.
1250
1251 If unsure, say N.
1252
1da177e4
LT
1253config DEBUG_PREEMPT
1254 bool "Debug preemptible kernel"
9f472869 1255 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1256 default y
1257 help
1258 If you say Y here then the kernel will use a debug variant of the
1259 commonly used smp_processor_id() function and will print warnings
1260 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1261 will detect preemption count underflows.
1262
9eade16b
DH
1263menu "Lock Debugging (spinlocks, mutexes, etc...)"
1264
f07cbebb
WL
1265config LOCK_DEBUGGING_SUPPORT
1266 bool
1267 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1268 default y
1269
19193bca
WL
1270config PROVE_LOCKING
1271 bool "Lock debugging: prove locking correctness"
1272 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1273 select LOCKDEP
1274 select DEBUG_SPINLOCK
bb630f9f 1275 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca 1276 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1277 select DEBUG_RWSEMS
19193bca
WL
1278 select DEBUG_WW_MUTEX_SLOWPATH
1279 select DEBUG_LOCK_ALLOC
8fd8ad5c 1280 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1281 select TRACE_IRQFLAGS
1282 default n
1283 help
1284 This feature enables the kernel to prove that all locking
1285 that occurs in the kernel runtime is mathematically
1286 correct: that under no circumstance could an arbitrary (and
1287 not yet triggered) combination of observed locking
1288 sequences (on an arbitrary number of CPUs, running an
1289 arbitrary number of tasks and interrupt contexts) cause a
1290 deadlock.
1291
1292 In short, this feature enables the kernel to report locking
1293 related deadlocks before they actually occur.
1294
1295 The proof does not depend on how hard and complex a
1296 deadlock scenario would be to trigger: how many
1297 participant CPUs, tasks and irq-contexts would be needed
1298 for it to trigger. The proof also does not depend on
1299 timing: if a race and a resulting deadlock is possible
1300 theoretically (no matter how unlikely the race scenario
1301 is), it will be proven so and will immediately be
1302 reported by the kernel (once the event is observed that
1303 makes the deadlock theoretically possible).
1304
1305 If a deadlock is impossible (i.e. the locking rules, as
1306 observed by the kernel, are mathematically correct), the
1307 kernel reports nothing.
1308
1309 NOTE: this feature can also be enabled for rwlocks, mutexes
1310 and rwsems - in which case all dependencies between these
1311 different locking variants are observed and mapped too, and
1312 the proof of observed correctness is also maintained for an
1313 arbitrary combination of these separate locking variants.
1314
387b1468 1315 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1316
de8f5e4f
PZ
1317config PROVE_RAW_LOCK_NESTING
1318 bool "Enable raw_spinlock - spinlock nesting checks"
1319 depends on PROVE_LOCKING
1320 default n
1321 help
1322 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1323 that the lock nesting rules for PREEMPT_RT enabled kernels are
1324 not violated.
1325
1326 NOTE: There are known nesting problems. So if you enable this
1327 option expect lockdep splats until these problems have been fully
1328 addressed which is work in progress. This config switch allows to
1329 identify and analyze these problems. It will be removed and the
9dbbc3b9 1330 check permanently enabled once the main issues have been fixed.
de8f5e4f
PZ
1331
1332 If unsure, select N.
1333
19193bca
WL
1334config LOCK_STAT
1335 bool "Lock usage statistics"
1336 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1337 select LOCKDEP
1338 select DEBUG_SPINLOCK
bb630f9f 1339 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca
WL
1340 select DEBUG_RT_MUTEXES if RT_MUTEXES
1341 select DEBUG_LOCK_ALLOC
1342 default n
1343 help
1344 This feature enables tracking lock contention points
1345
387b1468 1346 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1347
1348 This also enables lock events required by "perf lock",
1349 subcommand of perf.
1350 If you want to use "perf lock", you also need to turn on
1351 CONFIG_EVENT_TRACING.
1352
1353 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1354 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1355
e7eebaf6
IM
1356config DEBUG_RT_MUTEXES
1357 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1358 depends on DEBUG_KERNEL && RT_MUTEXES
1359 help
1360 This allows rt mutex semantics violations and rt mutex related
1361 deadlocks (lockups) to be detected and reported automatically.
1362
1da177e4 1363config DEBUG_SPINLOCK
4d9f34ad 1364 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1365 depends on DEBUG_KERNEL
e335e3eb 1366 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1367 help
1368 Say Y here and build SMP to catch missing spinlock initialization
1369 and certain other kinds of spinlock errors commonly made. This is
1370 best used in conjunction with the NMI watchdog so that spinlock
1371 deadlocks are also debuggable.
1372
4d9f34ad
IM
1373config DEBUG_MUTEXES
1374 bool "Mutex debugging: basic checks"
bb630f9f 1375 depends on DEBUG_KERNEL && !PREEMPT_RT
4d9f34ad
IM
1376 help
1377 This feature allows mutex semantics violations to be detected and
1378 reported.
1379
23010027
DV
1380config DEBUG_WW_MUTEX_SLOWPATH
1381 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1382 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1383 select DEBUG_LOCK_ALLOC
1384 select DEBUG_SPINLOCK
bb630f9f
TG
1385 select DEBUG_MUTEXES if !PREEMPT_RT
1386 select DEBUG_RT_MUTEXES if PREEMPT_RT
23010027
DV
1387 help
1388 This feature enables slowpath testing for w/w mutex users by
1389 injecting additional -EDEADLK wound/backoff cases. Together with
1390 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1391 will test all possible w/w mutex interface abuse with the
1392 exception of simply not acquiring all the required locks.
4d692373
RC
1393 Note that this feature can introduce significant overhead, so
1394 it really should not be enabled in a production or distro kernel,
1395 even a debug kernel. If you are a driver writer, enable it. If
1396 you are a distro, do not.
23010027 1397
5149cbac
WL
1398config DEBUG_RWSEMS
1399 bool "RW Semaphore debugging: basic checks"
c71fd893 1400 depends on DEBUG_KERNEL
5149cbac 1401 help
c71fd893
WL
1402 This debugging feature allows mismatched rw semaphore locks
1403 and unlocks to be detected and reported.
5149cbac 1404
4d9f34ad
IM
1405config DEBUG_LOCK_ALLOC
1406 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1407 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1408 select DEBUG_SPINLOCK
bb630f9f 1409 select DEBUG_MUTEXES if !PREEMPT_RT
f5694788 1410 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1411 select LOCKDEP
1412 help
1413 This feature will check whether any held lock (spinlock, rwlock,
1414 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1415 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1416 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1417 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1418 held during task exit.
1419
4d9f34ad
IM
1420config LOCKDEP
1421 bool
f07cbebb 1422 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1423 select STACKTRACE
4d9f34ad
IM
1424 select KALLSYMS
1425 select KALLSYMS_ALL
1426
395102db
DJ
1427config LOCKDEP_SMALL
1428 bool
1429
5dc33592
TH
1430config LOCKDEP_BITS
1431 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1432 depends on LOCKDEP && !LOCKDEP_SMALL
1433 range 10 30
1434 default 15
1435 help
1436 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1437
1438config LOCKDEP_CHAINS_BITS
1439 int "Bitsize for MAX_LOCKDEP_CHAINS"
1440 depends on LOCKDEP && !LOCKDEP_SMALL
1441 range 10 30
1442 default 16
1443 help
1444 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1445
1446config LOCKDEP_STACK_TRACE_BITS
1447 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1448 depends on LOCKDEP && !LOCKDEP_SMALL
1449 range 10 30
1450 default 19
1451 help
1452 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1453
1454config LOCKDEP_STACK_TRACE_HASH_BITS
1455 int "Bitsize for STACK_TRACE_HASH_SIZE"
1456 depends on LOCKDEP && !LOCKDEP_SMALL
1457 range 10 30
1458 default 14
1459 help
1460 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1461
1462config LOCKDEP_CIRCULAR_QUEUE_BITS
1463 int "Bitsize for elements in circular_queue struct"
1464 depends on LOCKDEP
1465 range 10 30
1466 default 12
1467 help
1468 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1469
4d9f34ad
IM
1470config DEBUG_LOCKDEP
1471 bool "Lock dependency engine debugging"
517e7aa5 1472 depends on DEBUG_KERNEL && LOCKDEP
997acaf6 1473 select DEBUG_IRQFLAGS
4d9f34ad
IM
1474 help
1475 If you say Y here, the lock dependency engine will do
1476 additional runtime checks to debug itself, at the price
1477 of more runtime overhead.
1478
d902db1e
FW
1479config DEBUG_ATOMIC_SLEEP
1480 bool "Sleep inside atomic section checking"
e8f7c70f 1481 select PREEMPT_COUNT
1da177e4 1482 depends on DEBUG_KERNEL
87a4c375 1483 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1484 help
1485 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1486 noisy if they are called inside atomic sections: when a spinlock is
1487 held, inside an rcu read side critical section, inside preempt disabled
1488 sections, inside an interrupt, etc...
1da177e4 1489
cae2ed9a
IM
1490config DEBUG_LOCKING_API_SELFTESTS
1491 bool "Locking API boot-time self-tests"
1492 depends on DEBUG_KERNEL
1493 help
1494 Say Y here if you want the kernel to run a short self-test during
1495 bootup. The self-test checks whether common types of locking bugs
1496 are detected by debugging mechanisms or not. (if you disable
9dbbc3b9 1497 lock debugging then those bugs won't be detected of course.)
cae2ed9a
IM
1498 The following locking APIs are covered: spinlocks, rwlocks,
1499 mutexes and rwsems.
1500
0af3fe1e
PM
1501config LOCK_TORTURE_TEST
1502 tristate "torture tests for locking"
1503 depends on DEBUG_KERNEL
1504 select TORTURE_TEST
0af3fe1e
PM
1505 help
1506 This option provides a kernel module that runs torture tests
1507 on kernel locking primitives. The kernel module may be built
1508 after the fact on the running kernel to be tested, if desired.
1509
1510 Say Y here if you want kernel locking-primitive torture tests
1511 to be built into the kernel.
1512 Say M if you want these torture tests to build as a module.
1513 Say N if you are unsure.
1514
f2a5fec1
CW
1515config WW_MUTEX_SELFTEST
1516 tristate "Wait/wound mutex selftests"
1517 help
1518 This option provides a kernel module that runs tests on the
1519 on the struct ww_mutex locking API.
1520
1521 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1522 with this test harness.
1523
1524 Say M if you want these self tests to build as a module.
1525 Say N if you are unsure.
1526
e9d338a0
PM
1527config SCF_TORTURE_TEST
1528 tristate "torture tests for smp_call_function*()"
1529 depends on DEBUG_KERNEL
1530 select TORTURE_TEST
1531 help
1532 This option provides a kernel module that runs torture tests
1533 on the smp_call_function() family of primitives. The kernel
1534 module may be built after the fact on the running kernel to
1535 be tested, if desired.
1536
35feb604
PM
1537config CSD_LOCK_WAIT_DEBUG
1538 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1539 depends on DEBUG_KERNEL
1540 depends on 64BIT
1541 default n
1542 help
1543 This option enables debug prints when CPUs are slow to respond
1544 to the smp_call_function*() IPI wrappers. These debug prints
1545 include the IPI handler function currently executing (if any)
1546 and relevant stack traces.
1547
3c5b9039
DW
1548choice
1549 prompt "Lock debugging: prove subsystem device_lock() correctness"
1550 depends on PROVE_LOCKING
1551 help
1552 For subsystems that have instrumented their usage of the device_lock()
1553 with nested annotations, enable lock dependency checking. The locking
1554 hierarchy 'subclass' identifiers are not compatible across
1555 sub-systems, so only one can be enabled at a time.
1556
1557config PROVE_NVDIMM_LOCKING
1558 bool "NVDIMM"
1559 depends on LIBNVDIMM
1560 help
1561 Enable lockdep to validate nd_device_lock() usage.
1562
1563config PROVE_CXL_LOCKING
1564 bool "CXL"
1565 depends on CXL_BUS
1566 help
1567 Enable lockdep to validate cxl_device_lock() usage.
1568
1569endchoice
1570
9eade16b 1571endmenu # lock debugging
8637c099 1572
9eade16b 1573config TRACE_IRQFLAGS
ed004953 1574 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1575 bool
5ca43f6c 1576 help
9eade16b
DH
1577 Enables hooks to interrupt enabling and disabling for
1578 either tracing or lock debugging.
5ca43f6c 1579
ed004953 1580config TRACE_IRQFLAGS_NMI
1581 def_bool y
1582 depends on TRACE_IRQFLAGS
1583 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1584
997acaf6
MR
1585config DEBUG_IRQFLAGS
1586 bool "Debug IRQ flag manipulation"
1587 help
1588 Enables checks for potentially unsafe enabling or disabling of
1589 interrupts, such as calling raw_local_irq_restore() when interrupts
1590 are enabled.
1591
8637c099 1592config STACKTRACE
0c38e1fe 1593 bool "Stack backtrace support"
8637c099 1594 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1595 help
1596 This option causes the kernel to create a /proc/pid/stack for
1597 every process, showing its current stack trace.
1598 It is also used by various kernel debugging features that require
1599 stack trace generation.
5ca43f6c 1600
eecabf56
TT
1601config WARN_ALL_UNSEEDED_RANDOM
1602 bool "Warn for all uses of unseeded randomness"
1603 default n
d06bfd19
JD
1604 help
1605 Some parts of the kernel contain bugs relating to their use of
1606 cryptographically secure random numbers before it's actually possible
1607 to generate those numbers securely. This setting ensures that these
1608 flaws don't go unnoticed, by enabling a message, should this ever
1609 occur. This will allow people with obscure setups to know when things
1610 are going wrong, so that they might contact developers about fixing
1611 it.
1612
eecabf56
TT
1613 Unfortunately, on some models of some architectures getting
1614 a fully seeded CRNG is extremely difficult, and so this can
1615 result in dmesg getting spammed for a surprisingly long
1616 time. This is really bad from a security perspective, and
1617 so architecture maintainers really need to do what they can
1618 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1619 However, since users cannot do anything actionable to
eecabf56
TT
1620 address this, by default the kernel will issue only a single
1621 warning for the first use of unseeded randomness.
1622
1623 Say Y here if you want to receive warnings for all uses of
1624 unseeded randomness. This will be of use primarily for
4c5d114e 1625 those developers interested in improving the security of
eecabf56
TT
1626 Linux kernels running on their architecture (or
1627 subarchitecture).
d06bfd19 1628
1da177e4
LT
1629config DEBUG_KOBJECT
1630 bool "kobject debugging"
1631 depends on DEBUG_KERNEL
1632 help
1633 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1634 to the syslog.
1da177e4 1635
c817a67e
RK
1636config DEBUG_KOBJECT_RELEASE
1637 bool "kobject release debugging"
2a999aa0 1638 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1639 help
1640 kobjects are reference counted objects. This means that their
1641 last reference count put is not predictable, and the kobject can
1642 live on past the point at which a driver decides to drop it's
1643 initial reference to the kobject gained on allocation. An
1644 example of this would be a struct device which has just been
1645 unregistered.
1646
1647 However, some buggy drivers assume that after such an operation,
1648 the memory backing the kobject can be immediately freed. This
1649 goes completely against the principles of a refcounted object.
1650
1651 If you say Y here, the kernel will delay the release of kobjects
1652 on the last reference count to improve the visibility of this
1653 kind of kobject release bug.
1654
9b2a60c4
CM
1655config HAVE_DEBUG_BUGVERBOSE
1656 bool
1657
3be5cbcd 1658menu "Debug kernel data structures"
1da177e4 1659
199a9afc
DJ
1660config DEBUG_LIST
1661 bool "Debug linked list manipulation"
4520bcb2 1662 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1663 help
1664 Enable this to turn on extended checks in the linked-list
1665 walking routines.
1666
1667 If unsure, say N.
1668
8e18faea 1669config DEBUG_PLIST
b8cfff68
DS
1670 bool "Debug priority linked list manipulation"
1671 depends on DEBUG_KERNEL
1672 help
1673 Enable this to turn on extended checks in the priority-ordered
1674 linked-list (plist) walking routines. This checks the entire
1675 list multiple times during each manipulation.
1676
1677 If unsure, say N.
1678
d6ec0842
JA
1679config DEBUG_SG
1680 bool "Debug SG table operations"
1681 depends on DEBUG_KERNEL
1682 help
1683 Enable this to turn on checks on scatter-gather tables. This can
1684 help find problems with drivers that do not properly initialize
1685 their sg tables.
1686
1687 If unsure, say N.
1688
1b2439db
AV
1689config DEBUG_NOTIFIERS
1690 bool "Debug notifier call chains"
1691 depends on DEBUG_KERNEL
1692 help
1693 Enable this to turn on sanity checking for notifier call chains.
1694 This is most useful for kernel developers to make sure that
1695 modules properly unregister themselves from notifier chains.
1696 This is a relatively cheap check but if you care about maximum
1697 performance, say N.
1698
3be5cbcd
CD
1699config BUG_ON_DATA_CORRUPTION
1700 bool "Trigger a BUG when data corruption is detected"
1701 select DEBUG_LIST
1702 help
1703 Select this option if the kernel should BUG when it encounters
1704 data corruption in kernel memory structures when they get checked
1705 for validity.
1706
1707 If unsure, say N.
1708
1709endmenu
1710
e0e81739
DH
1711config DEBUG_CREDENTIALS
1712 bool "Debug credential management"
1713 depends on DEBUG_KERNEL
1714 help
1715 Enable this to turn on some debug checking for credential
1716 management. The additional code keeps track of the number of
1717 pointers from task_structs to any given cred struct, and checks to
1718 see that this number never exceeds the usage count of the cred
1719 struct.
1720
1721 Furthermore, if SELinux is enabled, this also checks that the
1722 security pointer in the cred struct is never seen to be invalid.
1723
1724 If unsure, say N.
1725
43a0a2a7 1726source "kernel/rcu/Kconfig.debug"
2f03e3ca 1727
f303fccb
TH
1728config DEBUG_WQ_FORCE_RR_CPU
1729 bool "Force round-robin CPU selection for unbound work items"
1730 depends on DEBUG_KERNEL
1731 default n
1732 help
1733 Workqueue used to implicitly guarantee that work items queued
1734 without explicit CPU specified are put on the local CPU. This
1735 guarantee is no longer true and while local CPU is still
1736 preferred work items may be put on foreign CPUs. Kernel
1737 parameter "workqueue.debug_force_rr_cpu" is added to force
1738 round-robin CPU selection to flush out usages which depend on the
1739 now broken guarantee. This config option enables the debug
1740 feature by default. When enabled, memory and cache locality will
1741 be impacted.
1742
757c989b
TG
1743config CPU_HOTPLUG_STATE_CONTROL
1744 bool "Enable CPU hotplug state control"
1745 depends on DEBUG_KERNEL
1746 depends on HOTPLUG_CPU
1747 default n
1748 help
1749 Allows to write steps between "offline" and "online" to the CPUs
1750 sysfs target file so states can be stepped granular. This is a debug
1751 option for now as the hotplug machinery cannot be stopped and
1752 restarted at arbitrary points yet.
1753
1754 Say N if your are unsure.
1755
09a74952
CD
1756config LATENCYTOP
1757 bool "Latency measuring infrastructure"
1758 depends on DEBUG_KERNEL
1759 depends on STACKTRACE_SUPPORT
1760 depends on PROC_FS
7d37cb2c 1761 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
09a74952
CD
1762 select KALLSYMS
1763 select KALLSYMS_ALL
1764 select STACKTRACE
1765 select SCHEDSTATS
09a74952
CD
1766 help
1767 Enable this option if you want to use the LatencyTOP tool
1768 to find out which userspace is blocking on what kernel operations.
1769
1770source "kernel/trace/Kconfig"
1771
1772config PROVIDE_OHCI1394_DMA_INIT
1773 bool "Remote debugging over FireWire early on boot"
1774 depends on PCI && X86
1775 help
1776 If you want to debug problems which hang or crash the kernel early
1777 on boot and the crashing machine has a FireWire port, you can use
1778 this feature to remotely access the memory of the crashed machine
1779 over FireWire. This employs remote DMA as part of the OHCI1394
1780 specification which is now the standard for FireWire controllers.
1781
1782 With remote DMA, you can monitor the printk buffer remotely using
1783 firescope and access all memory below 4GB using fireproxy from gdb.
1784 Even controlling a kernel debugger is possible using remote DMA.
1785
1786 Usage:
1787
1788 If ohci1394_dma=early is used as boot parameter, it will initialize
1789 all OHCI1394 controllers which are found in the PCI config space.
1790
1791 As all changes to the FireWire bus such as enabling and disabling
1792 devices cause a bus reset and thereby disable remote DMA for all
1793 devices, be sure to have the cable plugged and FireWire enabled on
1794 the debugging host before booting the debug target for debugging.
1795
1796 This code (~1k) is freed after boot. By then, the firewire stack
1797 in charge of the OHCI-1394 controllers should be used instead.
1798
a74e2a22 1799 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1800
045f6d79
CD
1801source "samples/Kconfig"
1802
1803config ARCH_HAS_DEVMEM_IS_ALLOWED
1804 bool
1805
1806config STRICT_DEVMEM
1807 bool "Filter access to /dev/mem"
1808 depends on MMU && DEVMEM
527701ed 1809 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
045f6d79
CD
1810 default y if PPC || X86 || ARM64
1811 help
1812 If this option is disabled, you allow userspace (root) access to all
1813 of memory, including kernel and userspace memory. Accidental
1814 access to this is obviously disastrous, but specific access can
1815 be used by people debugging the kernel. Note that with PAT support
1816 enabled, even in this case there are restrictions on /dev/mem
1817 use due to the cache aliasing requirements.
1818
1819 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1820 file only allows userspace access to PCI space and the BIOS code and
1821 data regions. This is sufficient for dosemu and X and all common
1822 users of /dev/mem.
1823
1824 If in doubt, say Y.
1825
1826config IO_STRICT_DEVMEM
1827 bool "Filter I/O access to /dev/mem"
1828 depends on STRICT_DEVMEM
1829 help
1830 If this option is disabled, you allow userspace (root) access to all
1831 io-memory regardless of whether a driver is actively using that
1832 range. Accidental access to this is obviously disastrous, but
1833 specific access can be used by people debugging kernel drivers.
1834
1835 If this option is switched on, the /dev/mem file only allows
1836 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1837 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1838 if the driver using a given range cannot be disabled.
1839
1840 If in doubt, say Y.
1841
1842menu "$(SRCARCH) Debugging"
1843
1844source "arch/$(SRCARCH)/Kconfig.debug"
1845
1846endmenu
1847
1848menu "Kernel Testing and Coverage"
1849
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1850source "lib/kunit/Kconfig"
1851
8d438288
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1852config NOTIFIER_ERROR_INJECTION
1853 tristate "Notifier error injection"
1854 depends on DEBUG_KERNEL
1855 select DEBUG_FS
1856 help
e41e85cc 1857 This option provides the ability to inject artificial errors to
8d438288
AM
1858 specified notifier chain callbacks. It is useful to test the error
1859 handling of notifier call chain failures.
1860
1861 Say N if unsure.
1862
048b9c35
AM
1863config PM_NOTIFIER_ERROR_INJECT
1864 tristate "PM notifier error injection module"
1865 depends on PM && NOTIFIER_ERROR_INJECTION
1866 default m if PM_DEBUG
1867 help
e41e85cc 1868 This option provides the ability to inject artificial errors to
048b9c35
AM
1869 PM notifier chain callbacks. It is controlled through debugfs
1870 interface /sys/kernel/debug/notifier-error-inject/pm
1871
1872 If the notifier call chain should be failed with some events
1873 notified, write the error code to "actions/<notifier event>/error".
1874
1875 Example: Inject PM suspend error (-12 = -ENOMEM)
1876
1877 # cd /sys/kernel/debug/notifier-error-inject/pm/
1878 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1879 # echo mem > /sys/power/state
1880 bash: echo: write error: Cannot allocate memory
1881
1882 To compile this code as a module, choose M here: the module will
1883 be called pm-notifier-error-inject.
1884
1885 If unsure, say N.
1886
d526e85f
BH
1887config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1888 tristate "OF reconfig notifier error injection module"
1889 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1890 help
e41e85cc 1891 This option provides the ability to inject artificial errors to
d526e85f 1892 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1893 through debugfs interface under
d526e85f 1894 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1895
1896 If the notifier call chain should be failed with some events
1897 notified, write the error code to "actions/<notifier event>/error".
1898
1899 To compile this code as a module, choose M here: the module will
e12a95f4 1900 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1901
1902 If unsure, say N.
1903
02fff96a
NA
1904config NETDEV_NOTIFIER_ERROR_INJECT
1905 tristate "Netdev notifier error injection module"
1906 depends on NET && NOTIFIER_ERROR_INJECTION
1907 help
1908 This option provides the ability to inject artificial errors to
1909 netdevice notifier chain callbacks. It is controlled through debugfs
1910 interface /sys/kernel/debug/notifier-error-inject/netdev
1911
1912 If the notifier call chain should be failed with some events
1913 notified, write the error code to "actions/<notifier event>/error".
1914
1915 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1916
1917 # cd /sys/kernel/debug/notifier-error-inject/netdev
1918 # echo -22 > actions/NETDEV_CHANGEMTU/error
1919 # ip link set eth0 mtu 1024
1920 RTNETLINK answers: Invalid argument
1921
1922 To compile this code as a module, choose M here: the module will
1923 be called netdev-notifier-error-inject.
1924
1925 If unsure, say N.
1926
f1b4bd06
MP
1927config FUNCTION_ERROR_INJECTION
1928 def_bool y
1929 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1930
6ff1cb35 1931config FAULT_INJECTION
1ab8509a
AM
1932 bool "Fault-injection framework"
1933 depends on DEBUG_KERNEL
329409ae
AM
1934 help
1935 Provide fault-injection framework.
1936 For more details, see Documentation/fault-injection/.
6ff1cb35 1937
8a8b6502 1938config FAILSLAB
1ab8509a
AM
1939 bool "Fault-injection capability for kmalloc"
1940 depends on FAULT_INJECTION
773ff60e 1941 depends on SLAB || SLUB
8a8b6502 1942 help
1ab8509a 1943 Provide fault-injection capability for kmalloc.
8a8b6502 1944
933e312e 1945config FAIL_PAGE_ALLOC
29b46fa3 1946 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1947 depends on FAULT_INJECTION
933e312e 1948 help
1ab8509a 1949 Provide fault-injection capability for alloc_pages().
933e312e 1950
2c739ced
AL
1951config FAULT_INJECTION_USERCOPY
1952 bool "Fault injection capability for usercopy functions"
1953 depends on FAULT_INJECTION
1954 help
1955 Provides fault-injection capability to inject failures
1956 in usercopy functions (copy_from_user(), get_user(), ...).
1957
c17bb495 1958config FAIL_MAKE_REQUEST
86327d19 1959 bool "Fault-injection capability for disk IO"
581d4e28 1960 depends on FAULT_INJECTION && BLOCK
c17bb495 1961 help
1ab8509a 1962 Provide fault-injection capability for disk IO.
c17bb495 1963
581d4e28 1964config FAIL_IO_TIMEOUT
f4d01439 1965 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1966 depends on FAULT_INJECTION && BLOCK
1967 help
1968 Provide fault-injection capability on end IO handling. This
1969 will make the block layer "forget" an interrupt as configured,
1970 thus exercising the error handling.
1971
1972 Only works with drivers that use the generic timeout handling,
9dbbc3b9 1973 for others it won't do anything.
581d4e28 1974
ab51fbab
DB
1975config FAIL_FUTEX
1976 bool "Fault-injection capability for futexes"
1977 select DEBUG_FS
1978 depends on FAULT_INJECTION && FUTEX
1979 help
1980 Provide fault-injection capability for futexes.
1981
f1b4bd06
MP
1982config FAULT_INJECTION_DEBUG_FS
1983 bool "Debugfs entries for fault-injection capabilities"
1984 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1985 help
1986 Enable configuration of fault-injection capabilities via debugfs.
1987
4b1a29a7
MH
1988config FAIL_FUNCTION
1989 bool "Fault-injection capability for functions"
1990 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1991 help
1992 Provide function-based fault-injection capability.
1993 This will allow you to override a specific function with a return
1994 with given return value. As a result, function caller will see
1995 an error value and have to handle it. This is useful to test the
1996 error handling in various subsystems.
1997
f1b4bd06
MP
1998config FAIL_MMC_REQUEST
1999 bool "Fault-injection capability for MMC IO"
2000 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 2001 help
f1b4bd06
MP
2002 Provide fault-injection capability for MMC IO.
2003 This will make the mmc core return data errors. This is
2004 useful to test the error handling in the mmc block device
2005 and to test how the mmc host driver handles retries from
2006 the block device.
1df49008 2007
c782af25
CL
2008config FAIL_SUNRPC
2009 bool "Fault-injection capability for SunRPC"
2010 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2011 help
2012 Provide fault-injection capability for SunRPC and
2013 its consumers.
2014
1df49008
AM
2015config FAULT_INJECTION_STACKTRACE_FILTER
2016 bool "stacktrace filter for fault-injection capabilities"
2017 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 2018 depends on !X86_64
1df49008 2019 select STACKTRACE
7d37cb2c 2020 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1df49008
AM
2021 help
2022 Provide stacktrace filter for fault-injection capabilities
267c4025 2023
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2024config ARCH_HAS_KCOV
2025 bool
cc3fa840 2026 help
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CD
2027 An architecture should select this when it can successfully
2028 build and run with CONFIG_KCOV. This typically requires
2029 disabling instrumentation for some early boot code.
cc3fa840 2030
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CD
2031config CC_HAS_SANCOV_TRACE_PC
2032 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 2033
cc3fa840 2034
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CD
2035config KCOV
2036 bool "Code coverage for fuzzing"
2037 depends on ARCH_HAS_KCOV
2038 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
22102f45 2039 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
bece04b5 2040 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
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CD
2041 select DEBUG_FS
2042 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
22102f45 2043 select OBJTOOL if HAVE_NOINSTR_HACK
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CD
2044 help
2045 KCOV exposes kernel code coverage information in a form suitable
2046 for coverage-guided fuzzing (randomized testing).
cc3fa840 2047
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CD
2048 If RANDOMIZE_BASE is enabled, PC values will not be stable across
2049 different machines and across reboots. If you need stable PC values,
2050 disable RANDOMIZE_BASE.
cc3fa840 2051
09a74952 2052 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 2053
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CD
2054config KCOV_ENABLE_COMPARISONS
2055 bool "Enable comparison operands collection by KCOV"
2056 depends on KCOV
2057 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2058 help
2059 KCOV also exposes operands of every comparison in the instrumented
2060 code along with operand sizes and PCs of the comparison instructions.
2061 These operands can be used by fuzzing engines to improve the quality
2062 of fuzzing coverage.
cc3fa840 2063
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CD
2064config KCOV_INSTRUMENT_ALL
2065 bool "Instrument all code by default"
2066 depends on KCOV
2067 default y
2068 help
2069 If you are doing generic system call fuzzing (like e.g. syzkaller),
2070 then you will want to instrument the whole kernel and you should
2071 say y here. If you are doing more targeted fuzzing (like e.g.
2072 filesystem fuzzing with AFL) then you will want to enable coverage
2073 for more specific subsets of files, and should say n here.
84bc809e 2074
5ff3b30a
AK
2075config KCOV_IRQ_AREA_SIZE
2076 hex "Size of interrupt coverage collection area in words"
2077 depends on KCOV
2078 default 0x40000
2079 help
2080 KCOV uses preallocated per-cpu areas to collect coverage from
2081 soft interrupts. This specifies the size of those areas in the
2082 number of unsigned long words.
2083
d3deafaa
VL
2084menuconfig RUNTIME_TESTING_MENU
2085 bool "Runtime Testing"
908009e8 2086 def_bool y
d3deafaa
VL
2087
2088if RUNTIME_TESTING_MENU
881c5149
DH
2089
2090config LKDTM
2091 tristate "Linux Kernel Dump Test Tool Module"
2092 depends on DEBUG_FS
881c5149
DH
2093 help
2094 This module enables testing of the different dumping mechanisms by
2095 inducing system failures at predefined crash points.
2096 If you don't need it: say N
2097 Choose M here to compile this code as a module. The module will be
2098 called lkdtm.
2099
2100 Documentation on how to use the module can be found in
10ffebbe 2101 Documentation/fault-injection/provoke-crashes.rst
881c5149
DH
2102
2103config TEST_LIST_SORT
ebd09577
DL
2104 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2105 depends on KUNIT
2106 default KUNIT_ALL_TESTS
881c5149
DH
2107 help
2108 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
2109 executed only once during system boot (so affects only boot time),
2110 or at module load time.
881c5149
DH
2111
2112 If unsure, say N.
2113
6e24628d
IR
2114config TEST_MIN_HEAP
2115 tristate "Min heap test"
2116 depends on DEBUG_KERNEL || m
2117 help
2118 Enable this to turn on min heap function tests. This test is
2119 executed only once during system boot (so affects only boot time),
2120 or at module load time.
2121
2122 If unsure, say N.
2123
c5adae95 2124config TEST_SORT
36f33b56
DL
2125 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2126 depends on KUNIT
2127 default KUNIT_ALL_TESTS
c5adae95 2128 help
5c4e6798
GU
2129 This option enables the self-test function of 'sort()' at boot,
2130 or at module load time.
c5adae95
KF
2131
2132 If unsure, say N.
2133
5086ea4b
MR
2134config TEST_DIV64
2135 tristate "64bit/32bit division and modulo test"
2136 depends on DEBUG_KERNEL || m
2137 help
2138 Enable this to turn on 'do_div()' function test. This test is
2139 executed only once during system boot (so affects only boot time),
2140 or at module load time.
2141
2142 If unsure, say N.
2143
881c5149 2144config KPROBES_SANITY_TEST
e44e81c5 2145 tristate "Kprobes sanity tests"
881c5149
DH
2146 depends on DEBUG_KERNEL
2147 depends on KPROBES
e44e81c5 2148 depends on KUNIT
881c5149
DH
2149 help
2150 This option provides for testing basic kprobes functionality on
5a6cf77f 2151 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
2152 verified for functionality.
2153
2154 Say N if you are unsure.
2155
f4616fab
MH
2156config FPROBE_SANITY_TEST
2157 bool "Self test for fprobe"
2158 depends on DEBUG_KERNEL
2159 depends on FPROBE
2160 depends on KUNIT=y
2161 help
2162 This option will enable testing the fprobe when the system boot.
2163 A series of tests are made to verify that the fprobe is functioning
2164 properly.
2165
2166 Say N if you are unsure.
2167
881c5149
DH
2168config BACKTRACE_SELF_TEST
2169 tristate "Self test for the backtrace code"
2170 depends on DEBUG_KERNEL
881c5149
DH
2171 help
2172 This option provides a kernel module that can be used to test
2173 the kernel stack backtrace code. This option is not useful
2174 for distributions or general kernels, but only for kernel
2175 developers working on architecture code.
2176
2177 Note that if you want to also test saved backtraces, you will
2178 have to enable STACKTRACE as well.
2179
2180 Say N if you are unsure.
2181
914a7b50
ED
2182config TEST_REF_TRACKER
2183 tristate "Self test for reference tracker"
2184 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2185 select REF_TRACKER
2186 help
2187 This option provides a kernel module performing tests
2188 using reference tracker infrastructure.
2189
2190 Say N if you are unsure.
2191
910a742d
ML
2192config RBTREE_TEST
2193 tristate "Red-Black tree test"
7c993e11 2194 depends on DEBUG_KERNEL
910a742d
ML
2195 help
2196 A benchmark measuring the performance of the rbtree library.
2197 Also includes rbtree invariant checks.
2198
4b4f3acc
FB
2199config REED_SOLOMON_TEST
2200 tristate "Reed-Solomon library test"
2201 depends on DEBUG_KERNEL || m
2202 select REED_SOLOMON
2203 select REED_SOLOMON_ENC16
2204 select REED_SOLOMON_DEC16
2205 help
2206 This option enables the self-test function of rslib at boot,
2207 or at module load time.
2208
2209 If unsure, say N.
2210
fff3fd8a
ML
2211config INTERVAL_TREE_TEST
2212 tristate "Interval tree test"
0f789b67 2213 depends on DEBUG_KERNEL
a88cc108 2214 select INTERVAL_TREE
fff3fd8a
ML
2215 help
2216 A benchmark measuring the performance of the interval tree library
2217
623fd807
GT
2218config PERCPU_TEST
2219 tristate "Per cpu operations test"
2220 depends on m && DEBUG_KERNEL
2221 help
2222 Enable this option to build test module which validates per-cpu
2223 operations.
2224
2225 If unsure, say N.
2226
881c5149 2227config ATOMIC64_SELFTEST
55ded955 2228 tristate "Perform an atomic64_t self-test"
881c5149 2229 help
55ded955
GU
2230 Enable this option to test the atomic64_t functions at boot or
2231 at module load time.
881c5149
DH
2232
2233 If unsure, say N.
2234
2235config ASYNC_RAID6_TEST
2236 tristate "Self test for hardware accelerated raid6 recovery"
2237 depends on ASYNC_RAID6_RECOV
2238 select ASYNC_MEMCPY
a7f7f624 2239 help
881c5149
DH
2240 This is a one-shot self test that permutes through the
2241 recovery of all the possible two disk failure scenarios for a
2242 N-disk array. Recovery is performed with the asynchronous
2243 raid6 recovery routines, and will optionally use an offload
2244 engine if one is available.
2245
2246 If unsure, say N.
2247
64d1d77a
AS
2248config TEST_HEXDUMP
2249 tristate "Test functions located in the hexdump module at runtime"
2250
b2ff70a0
MC
2251config STRING_SELFTEST
2252 tristate "Test string functions at runtime"
2253
881c5149
DH
2254config TEST_STRING_HELPERS
2255 tristate "Test functions located in the string_helpers module at runtime"
2256
0b0600c8
TH
2257config TEST_STRSCPY
2258 tristate "Test strscpy*() family of functions at runtime"
2259
881c5149
DH
2260config TEST_KSTRTOX
2261 tristate "Test kstrto*() family of functions at runtime"
2262
707cc728
RV
2263config TEST_PRINTF
2264 tristate "Test printf() family of functions at runtime"
2265
50f530e1
RF
2266config TEST_SCANF
2267 tristate "Test scanf() family of functions at runtime"
2268
5fd003f5
DD
2269config TEST_BITMAP
2270 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2271 help
2272 Enable this option to test the bitmap functions at boot.
2273
2274 If unsure, say N.
2275
cfaff0e5
AS
2276config TEST_UUID
2277 tristate "Test functions located in the uuid module at runtime"
2278
ad3d6c72
MW
2279config TEST_XARRAY
2280 tristate "Test the XArray code at runtime"
2281
7e1e7763 2282config TEST_RHASHTABLE
9d6dbe1b 2283 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2284 help
2285 Enable this option to test the rhashtable functions at boot.
2286
2287 If unsure, say N.
2288
88168bf3
IB
2289config TEST_SIPHASH
2290 tristate "Perform selftest on siphash functions"
468a9428 2291 help
88168bf3
IB
2292 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2293 functions on boot (or module load).
468a9428
GS
2294
2295 This is intended to help people writing architecture-specific
2296 optimized versions. 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
VMI
2421config BITFIELD_KUNIT
2422 tristate "KUnit test bitfield functions at runtime"
2423 depends on KUNIT
2424 help
2425 Enable this option to test the bitfield functions at boot.
2426
2427 KUnit tests run during boot and output the results to the debug log
2428 in TAP format (http://testanything.org/). Only useful for kernel devs
2429 running the KUnit test harness, and not intended for inclusion into a
2430 production build.
2431
2432 For more information on KUnit and unit tests in general please refer
2433 to the KUnit documentation in Documentation/dev-tools/kunit/.
2434
2435 If unsure, say N.
2436
0acc968f
IB
2437config HASH_KUNIT_TEST
2438 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2439 depends on KUNIT
2440 default KUNIT_ALL_TESTS
2441 help
2442 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2443 integer (<linux/hash.h>) hash functions on boot.
2444
2445 KUnit tests run during boot and output the results to the debug log
2446 in TAP format (https://testanything.org/). Only useful for kernel devs
2447 running the KUnit test harness, and not intended for inclusion into a
2448 production build.
2449
2450 For more information on KUnit and unit tests in general please refer
2451 to the KUnit documentation in Documentation/dev-tools/kunit/.
2452
2453 This is intended to help people writing architecture-specific
2454 optimized versions. If unsure, say N.
2455
5df38ca6
AS
2456config RESOURCE_KUNIT_TEST
2457 tristate "KUnit test for resource API"
2458 depends on KUNIT
2459 help
2460 This builds the resource API unit test.
2461 Tests the logic of API provided by resource.c and ioport.h.
2462 For more information on KUnit and unit tests in general please refer
2463 to the KUnit documentation in Documentation/dev-tools/kunit/.
2464
2465 If unsure, say N.
2466
2cb80dbb 2467config SYSCTL_KUNIT_TEST
5f215aab 2468 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2469 depends on KUNIT
5f215aab 2470 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2471 help
2472 This builds the proc sysctl unit test, which runs on boot.
2473 Tests the API contract and implementation correctness of sysctl.
2474 For more information on KUnit and unit tests in general please refer
2475 to the KUnit documentation in Documentation/dev-tools/kunit/.
2476
2477 If unsure, say N.
2478
ea2dd7c0 2479config LIST_KUNIT_TEST
5f215aab 2480 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2481 depends on KUNIT
5f215aab 2482 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2483 help
2484 This builds the linked list KUnit test suite.
2485 It tests that the API and basic functionality of the list_head type
2486 and associated macros.
2487
2488 KUnit tests run during boot and output the results to the debug log
d89775fc 2489 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2490 running the KUnit test harness, and not intended for inclusion into a
2491 production build.
2492
2493 For more information on KUnit and unit tests in general please refer
2494 to the KUnit documentation in Documentation/dev-tools/kunit/.
2495
2496 If unsure, say N.
2497
33d599f0
MV
2498config LINEAR_RANGES_TEST
2499 tristate "KUnit test for linear_ranges"
2500 depends on KUNIT
2501 select LINEAR_RANGES
2502 help
2503 This builds the linear_ranges unit test, which runs on boot.
2504 Tests the linear_ranges logic correctness.
2505 For more information on KUnit and unit tests in general please refer
7546861a
AS
2506 to the KUnit documentation in Documentation/dev-tools/kunit/.
2507
2508 If unsure, say N.
2509
2510config CMDLINE_KUNIT_TEST
2511 tristate "KUnit test for cmdline API"
2512 depends on KUNIT
2513 help
2514 This builds the cmdline API unit test.
2515 Tests the logic of API provided by cmdline.c.
2516 For more information on KUnit and unit tests in general please refer
33d599f0
MV
2517 to the KUnit documentation in Documentation/dev-tools/kunit/.
2518
2519 If unsure, say N.
2520
6d511020
RF
2521config BITS_TEST
2522 tristate "KUnit test for bits.h"
2523 depends on KUNIT
2524 help
2525 This builds the bits unit test.
2526 Tests the logic of macros defined in bits.h.
2527 For more information on KUnit and unit tests in general please refer
2528 to the KUnit documentation in Documentation/dev-tools/kunit/.
2529
2530 If unsure, say N.
2531
1f9f78b1
OG
2532config SLUB_KUNIT_TEST
2533 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2534 depends on SLUB_DEBUG && KUNIT
2535 default KUNIT_ALL_TESTS
2536 help
2537 This builds SLUB allocator unit test.
2538 Tests SLUB cache debugging functionality.
2539 For more information on KUnit and unit tests in general please refer
2540 to the KUnit documentation in Documentation/dev-tools/kunit/.
2541
2542 If unsure, say N.
2543
b6c75c4a
TP
2544config RATIONAL_KUNIT_TEST
2545 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
8ba739ed 2546 depends on KUNIT && RATIONAL
b6c75c4a
TP
2547 default KUNIT_ALL_TESTS
2548 help
2549 This builds the rational math unit test.
2550 For more information on KUnit and unit tests in general please refer
2551 to the KUnit documentation in Documentation/dev-tools/kunit/.
2552
2553 If unsure, say N.
2554
bb95ebbe
KC
2555config MEMCPY_KUNIT_TEST
2556 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2557 depends on KUNIT
2558 default KUNIT_ALL_TESTS
2559 help
2560 Builds unit tests for memcpy(), memmove(), and memset() functions.
2561 For more information on KUnit and unit tests in general please refer
2562 to the KUnit documentation in Documentation/dev-tools/kunit/.
2563
2564 If unsure, say N.
2565
617f55e2
KC
2566config OVERFLOW_KUNIT_TEST
2567 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2568 depends on KUNIT
2569 default KUNIT_ALL_TESTS
2570 help
2571 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2572 related functions.
2573
2574 For more information on KUnit and unit tests in general please refer
2575 to the KUnit documentation in Documentation/dev-tools/kunit/.
2576
2577 If unsure, say N.
2578
02788ebc
KC
2579config STACKINIT_KUNIT_TEST
2580 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2581 depends on KUNIT
2582 default KUNIT_ALL_TESTS
2583 help
2584 Test if the kernel is zero-initializing stack variables and
2585 padding. Coverage is controlled by compiler flags,
2586 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2587 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2588 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2589
e704f93a
DR
2590config TEST_UDELAY
2591 tristate "udelay test driver"
e704f93a
DR
2592 help
2593 This builds the "udelay_test" module that helps to make sure
2594 that udelay() is working properly.
2595
2596 If unsure, say N.
2597
2bf9e0ab
IM
2598config TEST_STATIC_KEYS
2599 tristate "Test static keys"
579e1acb
JB
2600 depends on m
2601 help
2bf9e0ab 2602 Test the static key interfaces.
579e1acb
JB
2603
2604 If unsure, say N.
2605
d9c6a72d
LR
2606config TEST_KMOD
2607 tristate "kmod stress tester"
d9c6a72d 2608 depends on m
d9c6a72d 2609 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2610 depends on BLOCK
bbd2e05f 2611 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
d9c6a72d
LR
2612 select TEST_LKM
2613 select XFS_FS
2614 select TUN
2615 select BTRFS_FS
2616 help
2617 Test the kernel's module loading mechanism: kmod. kmod implements
2618 support to load modules using the Linux kernel's usermode helper.
2619 This test provides a series of tests against kmod.
2620
2621 Although technically you can either build test_kmod as a module or
2622 into the kernel we disallow building it into the kernel since
2623 it stress tests request_module() and this will very likely cause
2624 some issues by taking over precious threads available from other
2625 module load requests, ultimately this could be fatal.
2626
2627 To run tests run:
2628
2629 tools/testing/selftests/kmod/kmod.sh --help
2630
2631 If unsure, say N.
2632
e4dace36
FF
2633config TEST_DEBUG_VIRTUAL
2634 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2635 depends on DEBUG_VIRTUAL
2636 help
2637 Test the kernel's ability to detect incorrect calls to
2638 virt_to_phys() done against the non-linear part of the
2639 kernel's virtual address map.
2640
2641 If unsure, say N.
2642
ce76d938
AS
2643config TEST_MEMCAT_P
2644 tristate "Test memcat_p() helper function"
2645 help
2646 Test the memcat_p() helper for correctly merging two
2647 pointer arrays together.
2648
2649 If unsure, say N.
2650
a2818ee4
JL
2651config TEST_LIVEPATCH
2652 tristate "Test livepatching"
2653 default n
bae05437 2654 depends on DYNAMIC_DEBUG
a2818ee4
JL
2655 depends on LIVEPATCH
2656 depends on m
2657 help
2658 Test kernel livepatching features for correctness. The tests will
2659 load test modules that will be livepatched in various scenarios.
2660
2661 To run all the livepatching tests:
2662
2663 make -C tools/testing/selftests TARGETS=livepatch run_tests
2664
2665 Alternatively, individual tests may be invoked:
2666
2667 tools/testing/selftests/livepatch/test-callbacks.sh
2668 tools/testing/selftests/livepatch/test-livepatch.sh
2669 tools/testing/selftests/livepatch/test-shadow-vars.sh
2670
2671 If unsure, say N.
2672
0a020d41
JP
2673config TEST_OBJAGG
2674 tristate "Perform selftest on object aggreration manager"
2675 default n
2676 depends on OBJAGG
2677 help
2678 Enable this option to test object aggregation manager on boot
2679 (or module load).
2680
5015a300
AP
2681config TEST_MEMINIT
2682 tristate "Test heap/page initialization"
2683 help
2684 Test if the kernel is zero-initializing heap and page allocations.
2685 This can be useful to test init_on_alloc and init_on_free features.
2686
2687 If unsure, say N.
2688
b2ef9f5a
RC
2689config TEST_HMM
2690 tristate "Test HMM (Heterogeneous Memory Management)"
2691 depends on TRANSPARENT_HUGEPAGE
2692 depends on DEVICE_PRIVATE
2693 select HMM_MIRROR
2694 select MMU_NOTIFIER
2695 help
2696 This is a pseudo device driver solely for testing HMM.
2697 Say M here if you want to build the HMM test module.
2698 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2699
2700 If unsure, say N.
2701
e320d301
MWO
2702config TEST_FREE_PAGES
2703 tristate "Test freeing pages"
2704 help
2705 Test that a memory leak does not occur due to a race between
2706 freeing a block of pages and a speculative page reference.
2707 Loading this module is safe if your kernel has the bug fixed.
2708 If the bug is not fixed, it will leak gigabytes of memory and
2709 probably OOM your system.
2710
4185b3b9
PA
2711config TEST_FPU
2712 tristate "Test floating point operations in kernel space"
2713 depends on X86 && !KCOV_INSTRUMENT_ALL
2714 help
2715 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2716 which will trigger a sequence of floating point operations. This is used
2717 for self-testing floating point control register setting in
2718 kernel_fpu_begin().
2719
2720 If unsure, say N.
2721
1253b9b8
PM
2722config TEST_CLOCKSOURCE_WATCHDOG
2723 tristate "Test clocksource watchdog in kernel space"
2724 depends on CLOCKSOURCE_WATCHDOG
2725 help
2726 Enable this option to create a kernel module that will trigger
2727 a test of the clocksource watchdog. This module may be loaded
2728 via modprobe or insmod in which case it will run upon being
2729 loaded, or it may be built in, in which case it will run
2730 shortly after boot.
2731
2732 If unsure, say N.
2733
d3deafaa 2734endif # RUNTIME_TESTING_MENU
cc3fa840 2735
dce44566
AK
2736config ARCH_USE_MEMTEST
2737 bool
2738 help
2739 An architecture should select this when it uses early_memtest()
2740 during boot process.
2741
cc3fa840
RD
2742config MEMTEST
2743 bool "Memtest"
dce44566 2744 depends on ARCH_USE_MEMTEST
a7f7f624 2745 help
cc3fa840 2746 This option adds a kernel parameter 'memtest', which allows memtest
dce44566 2747 to be set and executed.
cc3fa840
RD
2748 memtest=0, mean disabled; -- default
2749 memtest=1, mean do 1 test pattern;
2750 ...
2751 memtest=17, mean do 17 test patterns.
2752 If you are unsure how to answer this question, answer N.
2753
21266be9 2754
06ec64b8 2755
af9ca6f9
BB
2756config HYPERV_TESTING
2757 bool "Microsoft Hyper-V driver testing"
2758 default n
2759 depends on HYPERV && DEBUG_FS
2760 help
2761 Select this option to enable Hyper-V vmbus testing.
2762
045f6d79
CD
2763endmenu # "Kernel Testing and Coverage"
2764
75442fb0
MCC
2765source "Documentation/Kconfig"
2766
06ec64b8 2767endmenu # Kernel hacking