rust: add `.rustfmt.toml`
[linux-2.6-block.git] / lib / Kconfig.debug
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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
32ef9e50 267 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
f9b3cd24 268 help
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269 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
270 if using clang without clang's integrated assembler, and gdb 7.0+.
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271
272 If you have consumers of DWARF debug info that are not ready for
273 newer revisions of DWARF, you may wish to choose this or have your
274 config select this.
275
276config DEBUG_INFO_DWARF5
277 bool "Generate DWARF Version 5 debuginfo"
278 select DEBUG_INFO
279 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
280 help
281 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
282 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
283 draft features until 7.0), and gdb 8.0+.
284
285 Changes to the structure of debug info in Version 5 allow for around
286 15-18% savings in resulting image and debug info section sizes as
287 compared to DWARF Version 4. DWARF Version 5 standardizes previous
288 extensions such as accelerators for symbol indexing and the format
289 for fission (.dwo/.dwp) files. Users may not want to select this
290 config if they rely on tooling that has not yet been updated to
291 support DWARF Version 5.
292
293endchoice # "Debug information"
6dfc0665 294
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295if DEBUG_INFO
296
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297config DEBUG_INFO_REDUCED
298 bool "Reduce debugging information"
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299 help
300 If you say Y here gcc is instructed to generate less debugging
301 information for structure types. This means that tools that
302 need full debugging information (like kgdb or systemtap) won't
303 be happy. But if you merely need debugging information to
304 resolve line numbers there is no loss. Advantage is that
305 build directory object sizes shrink dramatically over a full
306 DEBUG_INFO build and compile times are reduced too.
307 Only works with newer gcc versions.
308
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309config DEBUG_INFO_COMPRESSED
310 bool "Compressed debugging information"
10e68b02 311 depends on $(cc-option,-gz=zlib)
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312 depends on $(ld-option,--compress-debug-sections=zlib)
313 help
314 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
315 5.0+, binutils 2.26+, and zlib.
316
317 Users of dpkg-deb via scripts/package/builddeb may find an increase in
318 size of their debug .deb packages with this config set, due to the
319 debug info being compressed with zlib, then the object files being
320 recompressed with a different compression scheme. But this is still
321 preferable to setting $KDEB_COMPRESS to "none" which would be even
322 larger.
323
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324config DEBUG_INFO_SPLIT
325 bool "Produce split debuginfo in .dwo files"
9d937444 326 depends on $(cc-option,-gsplit-dwarf)
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327 help
328 Generate debug info into separate .dwo files. This significantly
329 reduces the build directory size for builds with DEBUG_INFO,
330 because it stores the information only once on disk in .dwo
331 files instead of multiple times in object files and executables.
332 In addition the debug information is also compressed.
333
334 Requires recent gcc (4.7+) and recent gdb/binutils.
335 Any tool that packages or reads debug information would need
336 to know about the .dwo files and include them.
337 Incompatible with older versions of ccache.
338
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339config DEBUG_INFO_BTF
340 bool "Generate BTF typeinfo"
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341 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
342 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
d9847eb8 343 depends on BPF_SYSCALL
52deda95 344 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
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345 help
346 Generate deduplicated BTF type information from DWARF debug info.
347 Turning this on expects presence of pahole tool, which will convert
348 DWARF type info into equivalent deduplicated BTF type info.
349
5f9ae91f 350config PAHOLE_HAS_SPLIT_BTF
6323c813 351 def_bool PAHOLE_VERSION >= 119
5f9ae91f 352
7472d5a6 353config PAHOLE_HAS_BTF_TAG
6323c813 354 def_bool PAHOLE_VERSION >= 123
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355 depends on CC_IS_CLANG
356 help
357 Decide whether pahole emits btf_tag attributes (btf_type_tag and
358 btf_decl_tag) or not. Currently only clang compiler implements
359 these attributes, so make the config depend on CC_IS_CLANG.
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360
361config DEBUG_INFO_BTF_MODULES
362 def_bool y
363 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
364 help
365 Generate compact split BTF type information for kernel modules.
366
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367config MODULE_ALLOW_BTF_MISMATCH
368 bool "Allow loading modules with non-matching BTF type info"
369 depends on DEBUG_INFO_BTF_MODULES
370 help
371 For modules whose split BTF does not match vmlinux, load without
372 BTF rather than refusing to load. The default behavior with
373 module BTF enabled is to reject modules with such mismatches;
374 this option will still load module BTF where possible but ignore
375 it when a mismatch is found.
376
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377config GDB_SCRIPTS
378 bool "Provide GDB scripts for kernel debugging"
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379 help
380 This creates the required links to GDB helper scripts in the
381 build directory. If you load vmlinux into gdb, the helper
382 scripts will be automatically imported by gdb as well, and
383 additional functions are available to analyze a Linux kernel
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384 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
385 for further details.
3ee7b3fa 386
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387endif # DEBUG_INFO
388
35bb5b1e 389config FRAME_WARN
a83e4ca2 390 int "Warn for stack frames larger than"
35bb5b1e 391 range 0 8192
0e07f663 392 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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393 default 2048 if PARISC
394 default 1536 if (!64BIT && XTENSA)
395 default 1024 if !64BIT
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396 default 2048 if 64BIT
397 help
398 Tell gcc to warn at build time for stack frames larger than this.
399 Setting this too low will cause a lot of warnings.
400 Setting it to 0 disables the warning.
35bb5b1e 401
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402config STRIP_ASM_SYMS
403 bool "Strip assembler-generated symbols during link"
404 default n
405 help
406 Strip internal assembler-generated symbols during a link (symbols
407 that look like '.Lxxx') so they don't pollute the output of
408 get_wchan() and suchlike.
409
1873e870 410config READABLE_ASM
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411 bool "Generate readable assembler code"
412 depends on DEBUG_KERNEL
7d73c3e9 413 depends on CC_IS_GCC
bf4735a4 414 help
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415 Disable some compiler optimizations that tend to generate human unreadable
416 assembler output. This may make the kernel slightly slower, but it helps
417 to keep kernel developers who have to stare a lot at assembler listings
418 sane.
bf4735a4 419
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420config HEADERS_INSTALL
421 bool "Install uapi headers to usr/include"
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422 depends on !UML
423 help
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424 This option will install uapi headers (headers exported to user-space)
425 into the usr/include directory for use during the kernel build.
426 This is unneeded for building the kernel itself, but needed for some
427 user-space program samples. It is also needed by some features such
428 as uapi header sanity checks.
429
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430config DEBUG_SECTION_MISMATCH
431 bool "Enable full Section mismatch analysis"
7d73c3e9 432 depends on CC_IS_GCC
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433 help
434 The section mismatch analysis checks if there are illegal
435 references from one section to another section.
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436 During linktime or runtime, some sections are dropped;
437 any use of code/data previously in these sections would
91341d4b 438 most likely result in an oops.
e809ab01 439 In the code, functions and variables are annotated with
0db0628d 440 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 441 which results in the code/data being placed in specific sections.
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442 The section mismatch analysis is always performed after a full
443 kernel build, and enabling this option causes the following
b7dca6dd 444 additional step to occur:
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445 - Add the option -fno-inline-functions-called-once to gcc commands.
446 When inlining a function annotated with __init in a non-init
447 function, we would lose the section information and thus
91341d4b 448 the analysis would not catch the illegal reference.
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449 This option tells gcc to inline less (but it does result in
450 a larger kernel).
91341d4b 451
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452config SECTION_MISMATCH_WARN_ONLY
453 bool "Make section mismatch errors non-fatal"
454 default y
455 help
456 If you say N here, the build process will fail if there are any
457 section mismatch, instead of just throwing warnings.
458
459 If unsure, say Y.
460
cf536e18 461config DEBUG_FORCE_FUNCTION_ALIGN_64B
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462 bool "Force all function address 64B aligned"
463 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
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464 help
465 There are cases that a commit from one domain changes the function
466 address alignment of other domains, and cause magic performance
467 bump (regression or improvement). Enable this option will help to
468 verify if the bump is caused by function alignment changes, while
469 it will slightly increase the kernel size and affect icache usage.
470
471 It is mainly for debug and performance tuning use.
472
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473#
474# Select this config option from the architecture Kconfig, if it
475# is preferred to always offer frame pointers as a config
476# option on the architecture (regardless of KERNEL_DEBUG):
477#
478config ARCH_WANT_FRAME_POINTERS
479 bool
f346f4b3 480
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481config FRAME_POINTER
482 bool "Compile the kernel with frame pointers"
a687a533 483 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 484 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 485 help
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486 If you say Y here the resulting kernel image will be slightly
487 larger and slower, but it gives very useful debugging information
488 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 489
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490config OBJTOOL
491 bool
492
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493config STACK_VALIDATION
494 bool "Compile-time stack metadata validation"
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495 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
496 select OBJTOOL
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497 default n
498 help
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499 Validate frame pointer rules at compile-time. This helps ensure that
500 runtime stack traces are more reliable.
ee9f8fce 501
b9ab5ebb 502 For more information, see
d6a21f2d 503 tools/objtool/Documentation/objtool.txt.
b9ab5ebb 504
0f620cef 505config NOINSTR_VALIDATION
6804c1af 506 bool
489e355b 507 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
03f16cd0 508 select OBJTOOL
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509 default y
510
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511config VMLINUX_MAP
512 bool "Generate vmlinux.map file when linking"
513 depends on EXPERT
514 help
515 Selecting this option will pass "-Map=vmlinux.map" to ld
516 when linking vmlinux. That file can be useful for verifying
517 and debugging magic section games, and for seeing which
518 pieces of code get eliminated with
519 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
520
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521config DEBUG_FORCE_WEAK_PER_CPU
522 bool "Force weak per-cpu definitions"
523 depends on DEBUG_KERNEL
8446f1d3 524 help
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525 s390 and alpha require percpu variables in modules to be
526 defined weak to work around addressing range issue which
527 puts the following two restrictions on percpu variable
528 definitions.
8446f1d3 529
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530 1. percpu symbols must be unique whether static or not
531 2. percpu variables can't be defined inside a function
8446f1d3 532
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533 To ensure that generic code follows the above rules, this
534 option forces all percpu variables to be defined as weak.
5f329089 535
6dfc0665 536endmenu # "Compiler options"
8446f1d3 537
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538menu "Generic Kernel Debugging Instruments"
539
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540config MAGIC_SYSRQ
541 bool "Magic SysRq key"
542 depends on !UML
543 help
544 If you say Y here, you will have some control over the system even
545 if the system crashes for example during kernel debugging (e.g., you
546 will be able to flush the buffer cache to disk, reboot the system
547 immediately or dump some status information). This is accomplished
548 by pressing various keys while holding SysRq (Alt+PrintScreen). It
549 also works on a serial console (on PC hardware at least), if you
550 send a BREAK and then within 5 seconds a command keypress. The
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551 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
552 Don't say Y unless you really know what this hack does.
8446f1d3 553
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554config MAGIC_SYSRQ_DEFAULT_ENABLE
555 hex "Enable magic SysRq key functions by default"
556 depends on MAGIC_SYSRQ
557 default 0x1
558 help
559 Specifies which SysRq key functions are enabled by default.
560 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 561 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 562
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563config MAGIC_SYSRQ_SERIAL
564 bool "Enable magic SysRq key over serial"
565 depends on MAGIC_SYSRQ
566 default y
567 help
568 Many embedded boards have a disconnected TTL level serial which can
569 generate some garbage that can lead to spurious false sysrq detects.
570 This option allows you to decide whether you want to enable the
571 magic SysRq key.
572
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573config MAGIC_SYSRQ_SERIAL_SEQUENCE
574 string "Char sequence that enables magic SysRq over serial"
575 depends on MAGIC_SYSRQ_SERIAL
576 default ""
577 help
578 Specifies a sequence of characters that can follow BREAK to enable
579 SysRq on a serial console.
580
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581 If unsure, leave an empty string and the option will not be enabled.
582
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583config DEBUG_FS
584 bool "Debug Filesystem"
585 help
586 debugfs is a virtual file system that kernel developers use to put
587 debugging files into. Enable this option to be able to read and
588 write to these files.
589
590 For detailed documentation on the debugfs API, see
591 Documentation/filesystems/.
592
593 If unsure, say N.
594
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595choice
596 prompt "Debugfs default access"
597 depends on DEBUG_FS
598 default DEBUG_FS_ALLOW_ALL
599 help
600 This selects the default access restrictions for debugfs.
601 It can be overridden with kernel command line option
602 debugfs=[on,no-mount,off]. The restrictions apply for API access
603 and filesystem registration.
604
605config DEBUG_FS_ALLOW_ALL
606 bool "Access normal"
607 help
608 No restrictions apply. Both API and filesystem registration
609 is on. This is the normal default operation.
610
611config DEBUG_FS_DISALLOW_MOUNT
612 bool "Do not register debugfs as filesystem"
613 help
614 The API is open but filesystem is not loaded. Clients can still do
615 their work and read with debug tools that do not need
616 debugfs filesystem.
617
618config DEBUG_FS_ALLOW_NONE
619 bool "No access"
620 help
621 Access is off. Clients get -PERM when trying to create nodes in
622 debugfs tree and debugfs is not registered as a filesystem.
623 Client can then back-off or continue without debugfs access.
624
625endchoice
626
6210b640 627source "lib/Kconfig.kgdb"
6210b640 628source "lib/Kconfig.ubsan"
2645d432 629source "lib/Kconfig.kcsan"
6210b640
CD
630
631endmenu
632
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ED
633menu "Networking Debugging"
634
635source "net/Kconfig.debug"
636
637endmenu # "Networking Debugging"
c66d7a27 638
0610c8a8 639menu "Memory Debugging"
fef2c9bc 640
8636a1f9 641source "mm/Kconfig.debug"
fef2c9bc 642
0610c8a8
DH
643config DEBUG_OBJECTS
644 bool "Debug object operations"
645 depends on DEBUG_KERNEL
9c44bc03 646 help
0610c8a8
DH
647 If you say Y here, additional code will be inserted into the
648 kernel to track the life time of various objects and validate
649 the operations on those objects.
9c44bc03 650
0610c8a8
DH
651config DEBUG_OBJECTS_SELFTEST
652 bool "Debug objects selftest"
653 depends on DEBUG_OBJECTS
654 help
655 This enables the selftest of the object debug code.
9c44bc03 656
0610c8a8
DH
657config DEBUG_OBJECTS_FREE
658 bool "Debug objects in freed memory"
659 depends on DEBUG_OBJECTS
660 help
661 This enables checks whether a k/v free operation frees an area
662 which contains an object which has not been deactivated
663 properly. This can make kmalloc/kfree-intensive workloads
664 much slower.
3ac7fe5a 665
c6f3a97f
TG
666config DEBUG_OBJECTS_TIMERS
667 bool "Debug timer objects"
668 depends on DEBUG_OBJECTS
669 help
670 If you say Y here, additional code will be inserted into the
671 timer routines to track the life time of timer objects and
672 validate the timer operations.
673
dc186ad7
TG
674config DEBUG_OBJECTS_WORK
675 bool "Debug work objects"
676 depends on DEBUG_OBJECTS
677 help
678 If you say Y here, additional code will be inserted into the
679 work queue routines to track the life time of work objects and
680 validate the work operations.
681
551d55a9
MD
682config DEBUG_OBJECTS_RCU_HEAD
683 bool "Debug RCU callbacks objects"
fc2ecf7e 684 depends on DEBUG_OBJECTS
551d55a9
MD
685 help
686 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
687
e2852ae8
TH
688config DEBUG_OBJECTS_PERCPU_COUNTER
689 bool "Debug percpu counter objects"
690 depends on DEBUG_OBJECTS
691 help
692 If you say Y here, additional code will be inserted into the
693 percpu counter routines to track the life time of percpu counter
694 objects and validate the percpu counter operations.
695
3ae70205
IM
696config DEBUG_OBJECTS_ENABLE_DEFAULT
697 int "debug_objects bootup default value (0-1)"
68d4b3df
KK
698 range 0 1
699 default "1"
700 depends on DEBUG_OBJECTS
701 help
702 Debug objects boot parameter default value
3ae70205 703
5035ebc6 704config SHRINKER_DEBUG
5035ebc6
RG
705 bool "Enable shrinker debugging support"
706 depends on DEBUG_FS
707 help
708 Say Y to enable the shrinker debugfs interface which provides
709 visibility into the kernel memory shrinkers subsystem.
710 Disable it to avoid an extra memory footprint.
711
b69ec42b
CM
712config HAVE_DEBUG_KMEMLEAK
713 bool
714
3bba00d7
CM
715config DEBUG_KMEMLEAK
716 bool "Kernel memory leak detector"
525c1f92 717 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 718 select DEBUG_FS
3bba00d7
CM
719 select STACKTRACE if STACKTRACE_SUPPORT
720 select KALLSYMS
b60e26a2 721 select CRC32
3bba00d7
CM
722 help
723 Say Y here if you want to enable the memory leak
724 detector. The memory allocation/freeing is traced in a way
725 similar to the Boehm's conservative garbage collector, the
726 difference being that the orphan objects are not freed but
727 only shown in /sys/kernel/debug/kmemleak. Enabling this
728 feature will introduce an overhead to memory
700199b0 729 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
730 details.
731
0610c8a8
DH
732 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
733 of finding leaks due to the slab objects poisoning.
734
735 In order to access the kmemleak file, debugfs needs to be
736 mounted (usually at /sys/kernel/debug).
737
c5665868
CM
738config DEBUG_KMEMLEAK_MEM_POOL_SIZE
739 int "Kmemleak memory pool size"
0610c8a8 740 depends on DEBUG_KMEMLEAK
c59180ae 741 range 200 1000000
b751c52b 742 default 16000
0610c8a8
DH
743 help
744 Kmemleak must track all the memory allocations to avoid
745 reporting false positives. Since memory may be allocated or
c5665868
CM
746 freed before kmemleak is fully initialised, use a static pool
747 of metadata objects to track such callbacks. After kmemleak is
748 fully initialised, this memory pool acts as an emergency one
749 if slab allocations fail.
0610c8a8
DH
750
751config DEBUG_KMEMLEAK_TEST
752 tristate "Simple test for the kernel memory leak detector"
753 depends on DEBUG_KMEMLEAK && m
754 help
755 This option enables a module that explicitly leaks memory.
756
757 If unsure, say N.
758
759config DEBUG_KMEMLEAK_DEFAULT_OFF
760 bool "Default kmemleak to off"
761 depends on DEBUG_KMEMLEAK
762 help
763 Say Y here to disable kmemleak by default. It can then be enabled
764 on the command line via kmemleak=on.
765
d53ce042
SK
766config DEBUG_KMEMLEAK_AUTO_SCAN
767 bool "Enable kmemleak auto scan thread on boot up"
768 default y
769 depends on DEBUG_KMEMLEAK
770 help
771 Depending on the cpu, kmemleak scan may be cpu intensive and can
772 stall user tasks at times. This option enables/disables automatic
773 kmemleak scan at boot up.
774
775 Say N here to disable kmemleak auto scan thread to stop automatic
776 scanning. Disabling this option disables automatic reporting of
777 memory leaks.
778
779 If unsure, say Y.
780
0610c8a8
DH
781config DEBUG_STACK_USAGE
782 bool "Stack utilization instrumentation"
6c31da34 783 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
784 help
785 Enables the display of the minimum amount of free stack which each
786 task has ever had available in the sysrq-T and sysrq-P debug output.
787
788 This option will slow down process creation somewhat.
789
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CD
790config SCHED_STACK_END_CHECK
791 bool "Detect stack corruption on calls to schedule()"
792 depends on DEBUG_KERNEL
793 default n
794 help
795 This option checks for a stack overrun on calls to schedule().
796 If the stack end location is found to be over written always panic as
797 the content of the corrupted region can no longer be trusted.
798 This is to ensure no erroneous behaviour occurs which could result in
799 data corruption or a sporadic crash at a later stage once the region
800 is examined. The runtime overhead introduced is minimal.
801
399145f9
AK
802config ARCH_HAS_DEBUG_VM_PGTABLE
803 bool
804 help
805 An architecture should select this when it can successfully
806 build and run DEBUG_VM_PGTABLE.
807
0610c8a8
DH
808config DEBUG_VM
809 bool "Debug VM"
810 depends on DEBUG_KERNEL
811 help
812 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 813 that may impact performance.
0610c8a8
DH
814
815 If unsure, say N.
816
4f115147
DB
817config DEBUG_VM_VMACACHE
818 bool "Debug VMA caching"
819 depends on DEBUG_VM
820 help
821 Enable this to turn on VMA caching debug information. Doing so
822 can cause significant overhead, so only enable it in non-production
823 environments.
824
825 If unsure, say N.
826
0610c8a8
DH
827config DEBUG_VM_RB
828 bool "Debug VM red-black trees"
829 depends on DEBUG_VM
830 help
a663dad6 831 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
832
833 If unsure, say N.
834
95ad9755
KS
835config DEBUG_VM_PGFLAGS
836 bool "Debug page-flags operations"
837 depends on DEBUG_VM
838 help
839 Enables extra validation on page flags operations.
840
841 If unsure, say N.
842
399145f9
AK
843config DEBUG_VM_PGTABLE
844 bool "Debug arch page table for semantics compliance"
845 depends on MMU
846 depends on ARCH_HAS_DEBUG_VM_PGTABLE
847 default y if DEBUG_VM
848 help
849 This option provides a debug method which can be used to test
850 architecture page table helper functions on various platforms in
851 verifying if they comply with expected generic MM semantics. This
852 will help architecture code in making sure that any changes or
853 new additions of these helpers still conform to expected
854 semantics of the generic MM. Platforms will have to opt in for
855 this through ARCH_HAS_DEBUG_VM_PGTABLE.
856
857 If unsure, say N.
858
fa5b6ec9
LA
859config ARCH_HAS_DEBUG_VIRTUAL
860 bool
861
0610c8a8
DH
862config DEBUG_VIRTUAL
863 bool "Debug VM translations"
fa5b6ec9 864 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
865 help
866 Enable some costly sanity checks in virtual to page code. This can
867 catch mistakes with virt_to_page() and friends.
868
869 If unsure, say N.
870
871config DEBUG_NOMMU_REGIONS
872 bool "Debug the global anon/private NOMMU mapping region tree"
873 depends on DEBUG_KERNEL && !MMU
874 help
875 This option causes the global tree of anonymous and private mapping
876 regions to be regularly checked for invalid topology.
877
878config DEBUG_MEMORY_INIT
879 bool "Debug memory initialisation" if EXPERT
880 default !EXPERT
881 help
882 Enable this for additional checks during memory initialisation.
883 The sanity checks verify aspects of the VM such as the memory model
884 and other information provided by the architecture. Verbose
885 information will be printed at KERN_DEBUG loglevel depending
886 on the mminit_loglevel= command-line option.
887
888 If unsure, say Y
889
890config MEMORY_NOTIFIER_ERROR_INJECT
891 tristate "Memory hotplug notifier error injection module"
50f9481e 892 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
0610c8a8
DH
893 help
894 This option provides the ability to inject artificial errors to
895 memory hotplug notifier chain callbacks. It is controlled through
896 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
897
898 If the notifier call chain should be failed with some events
899 notified, write the error code to "actions/<notifier event>/error".
900
901 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
902
903 # cd /sys/kernel/debug/notifier-error-inject/memory
904 # echo -12 > actions/MEM_GOING_OFFLINE/error
905 # echo offline > /sys/devices/system/memory/memoryXXX/state
906 bash: echo: write error: Cannot allocate memory
907
908 To compile this code as a module, choose M here: the module will
909 be called memory-notifier-error-inject.
910
911 If unsure, say N.
912
913config DEBUG_PER_CPU_MAPS
914 bool "Debug access to per_cpu maps"
915 depends on DEBUG_KERNEL
916 depends on SMP
917 help
918 Say Y to verify that the per_cpu map being accessed has
919 been set up. This adds a fair amount of code to kernel memory
920 and decreases performance.
921
922 Say N if unsure.
923
6e799cb6
TG
924config DEBUG_KMAP_LOCAL
925 bool "Debug kmap_local temporary mappings"
926 depends on DEBUG_KERNEL && KMAP_LOCAL
927 help
928 This option enables additional error checking for the kmap_local
929 infrastructure. Disable for production use.
930
0e91a0c6
TG
931config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
932 bool
933
934config DEBUG_KMAP_LOCAL_FORCE_MAP
935 bool "Enforce kmap_local temporary mappings"
936 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
937 select KMAP_LOCAL
938 select DEBUG_KMAP_LOCAL
939 help
940 This option enforces temporary mappings through the kmap_local
941 mechanism for non-highmem pages and on non-highmem systems.
942 Disable this for production systems!
943
0610c8a8
DH
944config DEBUG_HIGHMEM
945 bool "Highmem debugging"
946 depends on DEBUG_KERNEL && HIGHMEM
0e91a0c6 947 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
6e799cb6 948 select DEBUG_KMAP_LOCAL
0610c8a8 949 help
b1357c9f
GU
950 This option enables additional error checking for high memory
951 systems. Disable for production systems.
0610c8a8
DH
952
953config HAVE_DEBUG_STACKOVERFLOW
954 bool
955
956config DEBUG_STACKOVERFLOW
957 bool "Check for stack overflows"
958 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 959 help
0610c8a8 960 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 961 and exception stacks (if your architecture uses them). This
0610c8a8
DH
962 option will show detailed messages if free stack space drops
963 below a certain limit.
964
965 These kinds of bugs usually occur when call-chains in the
966 kernel get too deep, especially when interrupts are
967 involved.
968
969 Use this in cases where you see apparently random memory
970 corruption, especially if it appears in 'struct thread_info'
971
972 If in doubt, say "N".
973
0b24becc 974source "lib/Kconfig.kasan"
0ce20dd8 975source "lib/Kconfig.kfence"
0b24becc 976
0610c8a8
DH
977endmenu # "Memory Debugging"
978
a304e1b8
DW
979config DEBUG_SHIRQ
980 bool "Debug shared IRQ handlers"
0244ad00 981 depends on DEBUG_KERNEL
a304e1b8 982 help
0a2fae2a
WS
983 Enable this to generate a spurious interrupt just before a shared
984 interrupt handler is deregistered (generating one when registering
985 is currently disabled). Drivers need to handle this correctly. Some
986 don't and need to be caught.
a304e1b8 987
f43a289d
CD
988menu "Debug Oops, Lockups and Hangs"
989
990config PANIC_ON_OOPS
991 bool "Panic on Oops"
992 help
993 Say Y here to enable the kernel to panic when it oopses. This
994 has the same effect as setting oops=panic on the kernel command
995 line.
996
997 This feature is useful to ensure that the kernel does not do
998 anything erroneous after an oops which could result in data
999 corruption or other issues.
1000
1001 Say N if unsure.
1002
1003config PANIC_ON_OOPS_VALUE
1004 int
1005 range 0 1
1006 default 0 if !PANIC_ON_OOPS
1007 default 1 if PANIC_ON_OOPS
1008
1009config PANIC_TIMEOUT
1010 int "panic timeout"
1011 default 0
1012 help
9d5b134f 1013 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
1014 the kernel panics. If n = 0, then we wait forever. A timeout
1015 value n > 0 will wait n seconds before rebooting, while a timeout
1016 value n < 0 will reboot immediately.
92aef8fb 1017
58687acb 1018config LOCKUP_DETECTOR
05a4a952
NP
1019 bool
1020
1021config SOFTLOCKUP_DETECTOR
1022 bool "Detect Soft Lockups"
dea20a3f 1023 depends on DEBUG_KERNEL && !S390
05a4a952 1024 select LOCKUP_DETECTOR
8446f1d3 1025 help
58687acb 1026 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 1027 soft lockups.
58687acb
DZ
1028
1029 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 1030 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
1031 chance to run. The current stack trace is displayed upon
1032 detection and the system will stay locked up.
8446f1d3 1033
5f00ae0d
RD
1034config BOOTPARAM_SOFTLOCKUP_PANIC
1035 bool "Panic (Reboot) On Soft Lockups"
1036 depends on SOFTLOCKUP_DETECTOR
1037 help
1038 Say Y here to enable the kernel to panic on "soft lockups",
1039 which are bugs that cause the kernel to loop in kernel
1040 mode for more than 20 seconds (configurable using the watchdog_thresh
1041 sysctl), without giving other tasks a chance to run.
1042
1043 The panic can be used in combination with panic_timeout,
1044 to cause the system to reboot automatically after a
1045 lockup has been detected. This feature is useful for
1046 high-availability systems that have uptime guarantees and
1047 where a lockup must be resolved ASAP.
1048
1049 Say N if unsure.
1050
05a4a952
NP
1051config HARDLOCKUP_DETECTOR_PERF
1052 bool
1053 select SOFTLOCKUP_DETECTOR
1054
7edaeb68
TG
1055#
1056# Enables a timestamp based low pass filter to compensate for perf based
1057# hard lockup detection which runs too fast due to turbo modes.
1058#
1059config HARDLOCKUP_CHECK_TIMESTAMP
1060 bool
1061
05a4a952
NP
1062#
1063# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1064# lockup detector rather than the perf based detector.
1065#
1066config HARDLOCKUP_DETECTOR
1067 bool "Detect Hard Lockups"
1068 depends on DEBUG_KERNEL && !S390
1069 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1070 select LOCKUP_DETECTOR
1071 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
05a4a952
NP
1072 help
1073 Say Y here to enable the kernel to act as a watchdog to detect
1074 hard lockups.
1075
58687acb 1076 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 1077 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
1078 chance to run. The current stack trace is displayed upon detection
1079 and the system will stay locked up.
8446f1d3 1080
fef2c9bc
DZ
1081config BOOTPARAM_HARDLOCKUP_PANIC
1082 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 1083 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1084 help
1085 Say Y here to enable the kernel to panic on "hard lockups",
1086 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1087 mode with interrupts disabled for more than 10 seconds (configurable
1088 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1089
1090 Say N if unsure.
1091
e162b39a
MSB
1092config DETECT_HUNG_TASK
1093 bool "Detect Hung Tasks"
1094 depends on DEBUG_KERNEL
05a4a952 1095 default SOFTLOCKUP_DETECTOR
e162b39a 1096 help
0610c8a8
DH
1097 Say Y here to enable the kernel to detect "hung tasks",
1098 which are bugs that cause the task to be stuck in
96b03ab8 1099 uninterruptible "D" state indefinitely.
1da177e4 1100
0610c8a8
DH
1101 When a hung task is detected, the kernel will print the
1102 current stack trace (which you should report), but the
1103 task will stay in uninterruptible state. If lockdep is
1104 enabled then all held locks will also be reported. This
1105 feature has negligible overhead.
871751e2 1106
0610c8a8
DH
1107config DEFAULT_HUNG_TASK_TIMEOUT
1108 int "Default timeout for hung task detection (in seconds)"
1109 depends on DETECT_HUNG_TASK
1110 default 120
f0630fff 1111 help
0610c8a8
DH
1112 This option controls the default timeout (in seconds) used
1113 to determine when a task has become non-responsive and should
1114 be considered hung.
f0630fff 1115
0610c8a8
DH
1116 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1117 sysctl or by writing a value to
1118 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1119
0610c8a8
DH
1120 A timeout of 0 disables the check. The default is two minutes.
1121 Keeping the default should be fine in most cases.
b69ec42b 1122
0610c8a8
DH
1123config BOOTPARAM_HUNG_TASK_PANIC
1124 bool "Panic (Reboot) On Hung Tasks"
1125 depends on DETECT_HUNG_TASK
3bba00d7 1126 help
0610c8a8
DH
1127 Say Y here to enable the kernel to panic on "hung tasks",
1128 which are bugs that cause the kernel to leave a task stuck
1129 in uninterruptible "D" state.
3bba00d7 1130
0610c8a8
DH
1131 The panic can be used in combination with panic_timeout,
1132 to cause the system to reboot automatically after a
1133 hung task has been detected. This feature is useful for
1134 high-availability systems that have uptime guarantees and
1135 where a hung tasks must be resolved ASAP.
bf96d1e3 1136
0610c8a8 1137 Say N if unsure.
bf96d1e3 1138
82607adc
TH
1139config WQ_WATCHDOG
1140 bool "Detect Workqueue Stalls"
1141 depends on DEBUG_KERNEL
1142 help
1143 Say Y here to enable stall detection on workqueues. If a
1144 worker pool doesn't make forward progress on a pending work
1145 item for over a given amount of time, 30s by default, a
1146 warning message is printed along with dump of workqueue
1147 state. This can be configured through kernel parameter
1148 "workqueue.watchdog_thresh" and its sysfs counterpart.
1149
30428ef5
KK
1150config TEST_LOCKUP
1151 tristate "Test module to generate lockups"
63646bc9 1152 depends on m
30428ef5
KK
1153 help
1154 This builds the "test_lockup" module that helps to make sure
1155 that watchdogs and lockup detectors are working properly.
1156
1157 Depending on module parameters it could emulate soft or hard
1158 lockup, "hung task", or locking arbitrary lock for a long time.
1159 Also it could generate series of lockups with cooling-down periods.
1160
1161 If unsure, say N.
1162
92aef8fb
DH
1163endmenu # "Debug lockups and hangs"
1164
ebebdd09 1165menu "Scheduler Debugging"
5800dc3c 1166
0610c8a8
DH
1167config SCHED_DEBUG
1168 bool "Collect scheduler debugging info"
1169 depends on DEBUG_KERNEL && PROC_FS
1170 default y
0822ee4a 1171 help
0610c8a8
DH
1172 If you say Y here, the /proc/sched_debug file will be provided
1173 that can help debug the scheduler. The runtime overhead of this
1174 option is minimal.
0822ee4a 1175
f6db8347
NR
1176config SCHED_INFO
1177 bool
1178 default n
1179
0610c8a8
DH
1180config SCHEDSTATS
1181 bool "Collect scheduler statistics"
1182 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1183 select SCHED_INFO
0610c8a8
DH
1184 help
1185 If you say Y here, additional code will be inserted into the
1186 scheduler and related routines to collect statistics about
1187 scheduler behavior and provide them in /proc/schedstat. These
1188 stats may be useful for both tuning and debugging the scheduler
1189 If you aren't debugging the scheduler or trying to tune a specific
1190 application, you can say N to avoid the very slight overhead
1191 this adds.
0822ee4a 1192
ebebdd09 1193endmenu
0d9e2632 1194
3c17ad19
JS
1195config DEBUG_TIMEKEEPING
1196 bool "Enable extra timekeeping sanity checking"
1197 help
1198 This option will enable additional timekeeping sanity checks
1199 which may be helpful when diagnosing issues where timekeeping
1200 problems are suspected.
1201
1202 This may include checks in the timekeeping hotpaths, so this
1203 option may have a (very small) performance impact to some
1204 workloads.
1205
1206 If unsure, say N.
1207
1da177e4
LT
1208config DEBUG_PREEMPT
1209 bool "Debug preemptible kernel"
9f472869 1210 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1211 default y
1212 help
1213 If you say Y here then the kernel will use a debug variant of the
1214 commonly used smp_processor_id() function and will print warnings
1215 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1216 will detect preemption count underflows.
1217
9eade16b
DH
1218menu "Lock Debugging (spinlocks, mutexes, etc...)"
1219
f07cbebb
WL
1220config LOCK_DEBUGGING_SUPPORT
1221 bool
1222 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1223 default y
1224
19193bca
WL
1225config PROVE_LOCKING
1226 bool "Lock debugging: prove locking correctness"
1227 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1228 select LOCKDEP
1229 select DEBUG_SPINLOCK
bb630f9f 1230 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca 1231 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1232 select DEBUG_RWSEMS
19193bca
WL
1233 select DEBUG_WW_MUTEX_SLOWPATH
1234 select DEBUG_LOCK_ALLOC
8fd8ad5c 1235 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1236 select TRACE_IRQFLAGS
1237 default n
1238 help
1239 This feature enables the kernel to prove that all locking
1240 that occurs in the kernel runtime is mathematically
1241 correct: that under no circumstance could an arbitrary (and
1242 not yet triggered) combination of observed locking
1243 sequences (on an arbitrary number of CPUs, running an
1244 arbitrary number of tasks and interrupt contexts) cause a
1245 deadlock.
1246
1247 In short, this feature enables the kernel to report locking
1248 related deadlocks before they actually occur.
1249
1250 The proof does not depend on how hard and complex a
1251 deadlock scenario would be to trigger: how many
1252 participant CPUs, tasks and irq-contexts would be needed
1253 for it to trigger. The proof also does not depend on
1254 timing: if a race and a resulting deadlock is possible
1255 theoretically (no matter how unlikely the race scenario
1256 is), it will be proven so and will immediately be
1257 reported by the kernel (once the event is observed that
1258 makes the deadlock theoretically possible).
1259
1260 If a deadlock is impossible (i.e. the locking rules, as
1261 observed by the kernel, are mathematically correct), the
1262 kernel reports nothing.
1263
1264 NOTE: this feature can also be enabled for rwlocks, mutexes
1265 and rwsems - in which case all dependencies between these
1266 different locking variants are observed and mapped too, and
1267 the proof of observed correctness is also maintained for an
1268 arbitrary combination of these separate locking variants.
1269
387b1468 1270 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1271
de8f5e4f
PZ
1272config PROVE_RAW_LOCK_NESTING
1273 bool "Enable raw_spinlock - spinlock nesting checks"
1274 depends on PROVE_LOCKING
1275 default n
1276 help
1277 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1278 that the lock nesting rules for PREEMPT_RT enabled kernels are
1279 not violated.
1280
1281 NOTE: There are known nesting problems. So if you enable this
1282 option expect lockdep splats until these problems have been fully
1283 addressed which is work in progress. This config switch allows to
1284 identify and analyze these problems. It will be removed and the
9dbbc3b9 1285 check permanently enabled once the main issues have been fixed.
de8f5e4f
PZ
1286
1287 If unsure, select N.
1288
19193bca
WL
1289config LOCK_STAT
1290 bool "Lock usage statistics"
1291 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1292 select LOCKDEP
1293 select DEBUG_SPINLOCK
bb630f9f 1294 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca
WL
1295 select DEBUG_RT_MUTEXES if RT_MUTEXES
1296 select DEBUG_LOCK_ALLOC
1297 default n
1298 help
1299 This feature enables tracking lock contention points
1300
387b1468 1301 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1302
1303 This also enables lock events required by "perf lock",
1304 subcommand of perf.
1305 If you want to use "perf lock", you also need to turn on
1306 CONFIG_EVENT_TRACING.
1307
1308 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1309 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1310
e7eebaf6
IM
1311config DEBUG_RT_MUTEXES
1312 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1313 depends on DEBUG_KERNEL && RT_MUTEXES
1314 help
1315 This allows rt mutex semantics violations and rt mutex related
1316 deadlocks (lockups) to be detected and reported automatically.
1317
1da177e4 1318config DEBUG_SPINLOCK
4d9f34ad 1319 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1320 depends on DEBUG_KERNEL
e335e3eb 1321 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1322 help
1323 Say Y here and build SMP to catch missing spinlock initialization
1324 and certain other kinds of spinlock errors commonly made. This is
1325 best used in conjunction with the NMI watchdog so that spinlock
1326 deadlocks are also debuggable.
1327
4d9f34ad
IM
1328config DEBUG_MUTEXES
1329 bool "Mutex debugging: basic checks"
bb630f9f 1330 depends on DEBUG_KERNEL && !PREEMPT_RT
4d9f34ad
IM
1331 help
1332 This feature allows mutex semantics violations to be detected and
1333 reported.
1334
23010027
DV
1335config DEBUG_WW_MUTEX_SLOWPATH
1336 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1337 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1338 select DEBUG_LOCK_ALLOC
1339 select DEBUG_SPINLOCK
bb630f9f
TG
1340 select DEBUG_MUTEXES if !PREEMPT_RT
1341 select DEBUG_RT_MUTEXES if PREEMPT_RT
23010027
DV
1342 help
1343 This feature enables slowpath testing for w/w mutex users by
1344 injecting additional -EDEADLK wound/backoff cases. Together with
1345 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1346 will test all possible w/w mutex interface abuse with the
1347 exception of simply not acquiring all the required locks.
4d692373
RC
1348 Note that this feature can introduce significant overhead, so
1349 it really should not be enabled in a production or distro kernel,
1350 even a debug kernel. If you are a driver writer, enable it. If
1351 you are a distro, do not.
23010027 1352
5149cbac
WL
1353config DEBUG_RWSEMS
1354 bool "RW Semaphore debugging: basic checks"
c71fd893 1355 depends on DEBUG_KERNEL
5149cbac 1356 help
c71fd893
WL
1357 This debugging feature allows mismatched rw semaphore locks
1358 and unlocks to be detected and reported.
5149cbac 1359
4d9f34ad
IM
1360config DEBUG_LOCK_ALLOC
1361 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1362 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1363 select DEBUG_SPINLOCK
bb630f9f 1364 select DEBUG_MUTEXES if !PREEMPT_RT
f5694788 1365 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1366 select LOCKDEP
1367 help
1368 This feature will check whether any held lock (spinlock, rwlock,
1369 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1370 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1371 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1372 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1373 held during task exit.
1374
4d9f34ad
IM
1375config LOCKDEP
1376 bool
f07cbebb 1377 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1378 select STACKTRACE
4d9f34ad
IM
1379 select KALLSYMS
1380 select KALLSYMS_ALL
1381
395102db
DJ
1382config LOCKDEP_SMALL
1383 bool
1384
5dc33592
TH
1385config LOCKDEP_BITS
1386 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1387 depends on LOCKDEP && !LOCKDEP_SMALL
1388 range 10 30
1389 default 15
1390 help
1391 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1392
1393config LOCKDEP_CHAINS_BITS
1394 int "Bitsize for MAX_LOCKDEP_CHAINS"
1395 depends on LOCKDEP && !LOCKDEP_SMALL
1396 range 10 30
1397 default 16
1398 help
1399 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1400
1401config LOCKDEP_STACK_TRACE_BITS
1402 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1403 depends on LOCKDEP && !LOCKDEP_SMALL
1404 range 10 30
1405 default 19
1406 help
1407 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1408
1409config LOCKDEP_STACK_TRACE_HASH_BITS
1410 int "Bitsize for STACK_TRACE_HASH_SIZE"
1411 depends on LOCKDEP && !LOCKDEP_SMALL
1412 range 10 30
1413 default 14
1414 help
1415 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1416
1417config LOCKDEP_CIRCULAR_QUEUE_BITS
1418 int "Bitsize for elements in circular_queue struct"
1419 depends on LOCKDEP
1420 range 10 30
1421 default 12
1422 help
1423 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1424
4d9f34ad
IM
1425config DEBUG_LOCKDEP
1426 bool "Lock dependency engine debugging"
517e7aa5 1427 depends on DEBUG_KERNEL && LOCKDEP
997acaf6 1428 select DEBUG_IRQFLAGS
4d9f34ad
IM
1429 help
1430 If you say Y here, the lock dependency engine will do
1431 additional runtime checks to debug itself, at the price
1432 of more runtime overhead.
1433
d902db1e
FW
1434config DEBUG_ATOMIC_SLEEP
1435 bool "Sleep inside atomic section checking"
e8f7c70f 1436 select PREEMPT_COUNT
1da177e4 1437 depends on DEBUG_KERNEL
87a4c375 1438 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1439 help
1440 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1441 noisy if they are called inside atomic sections: when a spinlock is
1442 held, inside an rcu read side critical section, inside preempt disabled
1443 sections, inside an interrupt, etc...
1da177e4 1444
cae2ed9a
IM
1445config DEBUG_LOCKING_API_SELFTESTS
1446 bool "Locking API boot-time self-tests"
1447 depends on DEBUG_KERNEL
1448 help
1449 Say Y here if you want the kernel to run a short self-test during
1450 bootup. The self-test checks whether common types of locking bugs
1451 are detected by debugging mechanisms or not. (if you disable
9dbbc3b9 1452 lock debugging then those bugs won't be detected of course.)
cae2ed9a
IM
1453 The following locking APIs are covered: spinlocks, rwlocks,
1454 mutexes and rwsems.
1455
0af3fe1e
PM
1456config LOCK_TORTURE_TEST
1457 tristate "torture tests for locking"
1458 depends on DEBUG_KERNEL
1459 select TORTURE_TEST
0af3fe1e
PM
1460 help
1461 This option provides a kernel module that runs torture tests
1462 on kernel locking primitives. The kernel module may be built
1463 after the fact on the running kernel to be tested, if desired.
1464
1465 Say Y here if you want kernel locking-primitive torture tests
1466 to be built into the kernel.
1467 Say M if you want these torture tests to build as a module.
1468 Say N if you are unsure.
1469
f2a5fec1
CW
1470config WW_MUTEX_SELFTEST
1471 tristate "Wait/wound mutex selftests"
1472 help
1473 This option provides a kernel module that runs tests on the
1474 on the struct ww_mutex locking API.
1475
1476 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1477 with this test harness.
1478
1479 Say M if you want these self tests to build as a module.
1480 Say N if you are unsure.
1481
e9d338a0
PM
1482config SCF_TORTURE_TEST
1483 tristate "torture tests for smp_call_function*()"
1484 depends on DEBUG_KERNEL
1485 select TORTURE_TEST
1486 help
1487 This option provides a kernel module that runs torture tests
1488 on the smp_call_function() family of primitives. The kernel
1489 module may be built after the fact on the running kernel to
1490 be tested, if desired.
1491
35feb604
PM
1492config CSD_LOCK_WAIT_DEBUG
1493 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1494 depends on DEBUG_KERNEL
1495 depends on 64BIT
1496 default n
1497 help
1498 This option enables debug prints when CPUs are slow to respond
1499 to the smp_call_function*() IPI wrappers. These debug prints
1500 include the IPI handler function currently executing (if any)
1501 and relevant stack traces.
1502
9eade16b 1503endmenu # lock debugging
8637c099 1504
9eade16b 1505config TRACE_IRQFLAGS
ed004953 1506 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1507 bool
5ca43f6c 1508 help
9eade16b
DH
1509 Enables hooks to interrupt enabling and disabling for
1510 either tracing or lock debugging.
5ca43f6c 1511
ed004953 1512config TRACE_IRQFLAGS_NMI
1513 def_bool y
1514 depends on TRACE_IRQFLAGS
1515 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1516
997acaf6
MR
1517config DEBUG_IRQFLAGS
1518 bool "Debug IRQ flag manipulation"
1519 help
1520 Enables checks for potentially unsafe enabling or disabling of
1521 interrupts, such as calling raw_local_irq_restore() when interrupts
1522 are enabled.
1523
8637c099 1524config STACKTRACE
0c38e1fe 1525 bool "Stack backtrace support"
8637c099 1526 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1527 help
1528 This option causes the kernel to create a /proc/pid/stack for
1529 every process, showing its current stack trace.
1530 It is also used by various kernel debugging features that require
1531 stack trace generation.
5ca43f6c 1532
eecabf56
TT
1533config WARN_ALL_UNSEEDED_RANDOM
1534 bool "Warn for all uses of unseeded randomness"
1535 default n
d06bfd19
JD
1536 help
1537 Some parts of the kernel contain bugs relating to their use of
1538 cryptographically secure random numbers before it's actually possible
1539 to generate those numbers securely. This setting ensures that these
1540 flaws don't go unnoticed, by enabling a message, should this ever
1541 occur. This will allow people with obscure setups to know when things
1542 are going wrong, so that they might contact developers about fixing
1543 it.
1544
eecabf56
TT
1545 Unfortunately, on some models of some architectures getting
1546 a fully seeded CRNG is extremely difficult, and so this can
1547 result in dmesg getting spammed for a surprisingly long
1548 time. This is really bad from a security perspective, and
1549 so architecture maintainers really need to do what they can
1550 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1551 However, since users cannot do anything actionable to
cc1e127b 1552 address this, by default this option is disabled.
eecabf56
TT
1553
1554 Say Y here if you want to receive warnings for all uses of
1555 unseeded randomness. This will be of use primarily for
4c5d114e 1556 those developers interested in improving the security of
eecabf56
TT
1557 Linux kernels running on their architecture (or
1558 subarchitecture).
d06bfd19 1559
1da177e4
LT
1560config DEBUG_KOBJECT
1561 bool "kobject debugging"
1562 depends on DEBUG_KERNEL
1563 help
1564 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1565 to the syslog.
1da177e4 1566
c817a67e
RK
1567config DEBUG_KOBJECT_RELEASE
1568 bool "kobject release debugging"
2a999aa0 1569 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1570 help
1571 kobjects are reference counted objects. This means that their
1572 last reference count put is not predictable, and the kobject can
b6c69474 1573 live on past the point at which a driver decides to drop its
c817a67e
RK
1574 initial reference to the kobject gained on allocation. An
1575 example of this would be a struct device which has just been
1576 unregistered.
1577
1578 However, some buggy drivers assume that after such an operation,
1579 the memory backing the kobject can be immediately freed. This
1580 goes completely against the principles of a refcounted object.
1581
1582 If you say Y here, the kernel will delay the release of kobjects
1583 on the last reference count to improve the visibility of this
1584 kind of kobject release bug.
1585
9b2a60c4
CM
1586config HAVE_DEBUG_BUGVERBOSE
1587 bool
1588
3be5cbcd 1589menu "Debug kernel data structures"
1da177e4 1590
199a9afc
DJ
1591config DEBUG_LIST
1592 bool "Debug linked list manipulation"
4520bcb2 1593 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1594 help
1595 Enable this to turn on extended checks in the linked-list
1596 walking routines.
1597
1598 If unsure, say N.
1599
8e18faea 1600config DEBUG_PLIST
b8cfff68
DS
1601 bool "Debug priority linked list manipulation"
1602 depends on DEBUG_KERNEL
1603 help
1604 Enable this to turn on extended checks in the priority-ordered
1605 linked-list (plist) walking routines. This checks the entire
1606 list multiple times during each manipulation.
1607
1608 If unsure, say N.
1609
d6ec0842
JA
1610config DEBUG_SG
1611 bool "Debug SG table operations"
1612 depends on DEBUG_KERNEL
1613 help
1614 Enable this to turn on checks on scatter-gather tables. This can
1615 help find problems with drivers that do not properly initialize
1616 their sg tables.
1617
1618 If unsure, say N.
1619
1b2439db
AV
1620config DEBUG_NOTIFIERS
1621 bool "Debug notifier call chains"
1622 depends on DEBUG_KERNEL
1623 help
1624 Enable this to turn on sanity checking for notifier call chains.
1625 This is most useful for kernel developers to make sure that
1626 modules properly unregister themselves from notifier chains.
1627 This is a relatively cheap check but if you care about maximum
1628 performance, say N.
1629
3be5cbcd
CD
1630config BUG_ON_DATA_CORRUPTION
1631 bool "Trigger a BUG when data corruption is detected"
1632 select DEBUG_LIST
1633 help
1634 Select this option if the kernel should BUG when it encounters
1635 data corruption in kernel memory structures when they get checked
1636 for validity.
1637
1638 If unsure, say N.
1639
1640endmenu
1641
e0e81739
DH
1642config DEBUG_CREDENTIALS
1643 bool "Debug credential management"
1644 depends on DEBUG_KERNEL
1645 help
1646 Enable this to turn on some debug checking for credential
1647 management. The additional code keeps track of the number of
1648 pointers from task_structs to any given cred struct, and checks to
1649 see that this number never exceeds the usage count of the cred
1650 struct.
1651
1652 Furthermore, if SELinux is enabled, this also checks that the
1653 security pointer in the cred struct is never seen to be invalid.
1654
1655 If unsure, say N.
1656
43a0a2a7 1657source "kernel/rcu/Kconfig.debug"
2f03e3ca 1658
f303fccb
TH
1659config DEBUG_WQ_FORCE_RR_CPU
1660 bool "Force round-robin CPU selection for unbound work items"
1661 depends on DEBUG_KERNEL
1662 default n
1663 help
1664 Workqueue used to implicitly guarantee that work items queued
1665 without explicit CPU specified are put on the local CPU. This
1666 guarantee is no longer true and while local CPU is still
1667 preferred work items may be put on foreign CPUs. Kernel
1668 parameter "workqueue.debug_force_rr_cpu" is added to force
1669 round-robin CPU selection to flush out usages which depend on the
1670 now broken guarantee. This config option enables the debug
1671 feature by default. When enabled, memory and cache locality will
1672 be impacted.
1673
757c989b
TG
1674config CPU_HOTPLUG_STATE_CONTROL
1675 bool "Enable CPU hotplug state control"
1676 depends on DEBUG_KERNEL
1677 depends on HOTPLUG_CPU
1678 default n
1679 help
1680 Allows to write steps between "offline" and "online" to the CPUs
1681 sysfs target file so states can be stepped granular. This is a debug
1682 option for now as the hotplug machinery cannot be stopped and
1683 restarted at arbitrary points yet.
1684
1685 Say N if your are unsure.
1686
09a74952
CD
1687config LATENCYTOP
1688 bool "Latency measuring infrastructure"
1689 depends on DEBUG_KERNEL
1690 depends on STACKTRACE_SUPPORT
1691 depends on PROC_FS
7d37cb2c 1692 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
09a74952
CD
1693 select KALLSYMS
1694 select KALLSYMS_ALL
1695 select STACKTRACE
1696 select SCHEDSTATS
09a74952
CD
1697 help
1698 Enable this option if you want to use the LatencyTOP tool
1699 to find out which userspace is blocking on what kernel operations.
1700
1701source "kernel/trace/Kconfig"
1702
1703config PROVIDE_OHCI1394_DMA_INIT
1704 bool "Remote debugging over FireWire early on boot"
1705 depends on PCI && X86
1706 help
1707 If you want to debug problems which hang or crash the kernel early
1708 on boot and the crashing machine has a FireWire port, you can use
1709 this feature to remotely access the memory of the crashed machine
1710 over FireWire. This employs remote DMA as part of the OHCI1394
1711 specification which is now the standard for FireWire controllers.
1712
1713 With remote DMA, you can monitor the printk buffer remotely using
1714 firescope and access all memory below 4GB using fireproxy from gdb.
1715 Even controlling a kernel debugger is possible using remote DMA.
1716
1717 Usage:
1718
1719 If ohci1394_dma=early is used as boot parameter, it will initialize
1720 all OHCI1394 controllers which are found in the PCI config space.
1721
1722 As all changes to the FireWire bus such as enabling and disabling
1723 devices cause a bus reset and thereby disable remote DMA for all
1724 devices, be sure to have the cable plugged and FireWire enabled on
1725 the debugging host before booting the debug target for debugging.
1726
1727 This code (~1k) is freed after boot. By then, the firewire stack
1728 in charge of the OHCI-1394 controllers should be used instead.
1729
a74e2a22 1730 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1731
045f6d79
CD
1732source "samples/Kconfig"
1733
1734config ARCH_HAS_DEVMEM_IS_ALLOWED
1735 bool
1736
1737config STRICT_DEVMEM
1738 bool "Filter access to /dev/mem"
1739 depends on MMU && DEVMEM
527701ed 1740 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
045f6d79
CD
1741 default y if PPC || X86 || ARM64
1742 help
1743 If this option is disabled, you allow userspace (root) access to all
1744 of memory, including kernel and userspace memory. Accidental
1745 access to this is obviously disastrous, but specific access can
1746 be used by people debugging the kernel. Note that with PAT support
1747 enabled, even in this case there are restrictions on /dev/mem
1748 use due to the cache aliasing requirements.
1749
1750 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1751 file only allows userspace access to PCI space and the BIOS code and
1752 data regions. This is sufficient for dosemu and X and all common
1753 users of /dev/mem.
1754
1755 If in doubt, say Y.
1756
1757config IO_STRICT_DEVMEM
1758 bool "Filter I/O access to /dev/mem"
1759 depends on STRICT_DEVMEM
1760 help
1761 If this option is disabled, you allow userspace (root) access to all
1762 io-memory regardless of whether a driver is actively using that
1763 range. Accidental access to this is obviously disastrous, but
1764 specific access can be used by people debugging kernel drivers.
1765
1766 If this option is switched on, the /dev/mem file only allows
1767 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1768 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1769 if the driver using a given range cannot be disabled.
1770
1771 If in doubt, say Y.
1772
1773menu "$(SRCARCH) Debugging"
1774
1775source "arch/$(SRCARCH)/Kconfig.debug"
1776
1777endmenu
1778
1779menu "Kernel Testing and Coverage"
1780
09a74952
CD
1781source "lib/kunit/Kconfig"
1782
8d438288
AM
1783config NOTIFIER_ERROR_INJECTION
1784 tristate "Notifier error injection"
1785 depends on DEBUG_KERNEL
1786 select DEBUG_FS
1787 help
e41e85cc 1788 This option provides the ability to inject artificial errors to
8d438288
AM
1789 specified notifier chain callbacks. It is useful to test the error
1790 handling of notifier call chain failures.
1791
1792 Say N if unsure.
1793
048b9c35
AM
1794config PM_NOTIFIER_ERROR_INJECT
1795 tristate "PM notifier error injection module"
1796 depends on PM && NOTIFIER_ERROR_INJECTION
1797 default m if PM_DEBUG
1798 help
e41e85cc 1799 This option provides the ability to inject artificial errors to
048b9c35
AM
1800 PM notifier chain callbacks. It is controlled through debugfs
1801 interface /sys/kernel/debug/notifier-error-inject/pm
1802
1803 If the notifier call chain should be failed with some events
1804 notified, write the error code to "actions/<notifier event>/error".
1805
1806 Example: Inject PM suspend error (-12 = -ENOMEM)
1807
1808 # cd /sys/kernel/debug/notifier-error-inject/pm/
1809 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1810 # echo mem > /sys/power/state
1811 bash: echo: write error: Cannot allocate memory
1812
1813 To compile this code as a module, choose M here: the module will
1814 be called pm-notifier-error-inject.
1815
1816 If unsure, say N.
1817
d526e85f
BH
1818config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1819 tristate "OF reconfig notifier error injection module"
1820 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1821 help
e41e85cc 1822 This option provides the ability to inject artificial errors to
d526e85f 1823 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1824 through debugfs interface under
d526e85f 1825 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1826
1827 If the notifier call chain should be failed with some events
1828 notified, write the error code to "actions/<notifier event>/error".
1829
1830 To compile this code as a module, choose M here: the module will
e12a95f4 1831 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1832
1833 If unsure, say N.
1834
02fff96a
NA
1835config NETDEV_NOTIFIER_ERROR_INJECT
1836 tristate "Netdev notifier error injection module"
1837 depends on NET && NOTIFIER_ERROR_INJECTION
1838 help
1839 This option provides the ability to inject artificial errors to
1840 netdevice notifier chain callbacks. It is controlled through debugfs
1841 interface /sys/kernel/debug/notifier-error-inject/netdev
1842
1843 If the notifier call chain should be failed with some events
1844 notified, write the error code to "actions/<notifier event>/error".
1845
1846 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1847
1848 # cd /sys/kernel/debug/notifier-error-inject/netdev
1849 # echo -22 > actions/NETDEV_CHANGEMTU/error
1850 # ip link set eth0 mtu 1024
1851 RTNETLINK answers: Invalid argument
1852
1853 To compile this code as a module, choose M here: the module will
1854 be called netdev-notifier-error-inject.
1855
1856 If unsure, say N.
1857
f1b4bd06
MP
1858config FUNCTION_ERROR_INJECTION
1859 def_bool y
1860 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1861
6ff1cb35 1862config FAULT_INJECTION
1ab8509a
AM
1863 bool "Fault-injection framework"
1864 depends on DEBUG_KERNEL
329409ae
AM
1865 help
1866 Provide fault-injection framework.
1867 For more details, see Documentation/fault-injection/.
6ff1cb35 1868
8a8b6502 1869config FAILSLAB
1ab8509a
AM
1870 bool "Fault-injection capability for kmalloc"
1871 depends on FAULT_INJECTION
773ff60e 1872 depends on SLAB || SLUB
8a8b6502 1873 help
1ab8509a 1874 Provide fault-injection capability for kmalloc.
8a8b6502 1875
933e312e 1876config FAIL_PAGE_ALLOC
29b46fa3 1877 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1878 depends on FAULT_INJECTION
933e312e 1879 help
1ab8509a 1880 Provide fault-injection capability for alloc_pages().
933e312e 1881
2c739ced
AL
1882config FAULT_INJECTION_USERCOPY
1883 bool "Fault injection capability for usercopy functions"
1884 depends on FAULT_INJECTION
1885 help
1886 Provides fault-injection capability to inject failures
1887 in usercopy functions (copy_from_user(), get_user(), ...).
1888
c17bb495 1889config FAIL_MAKE_REQUEST
86327d19 1890 bool "Fault-injection capability for disk IO"
581d4e28 1891 depends on FAULT_INJECTION && BLOCK
c17bb495 1892 help
1ab8509a 1893 Provide fault-injection capability for disk IO.
c17bb495 1894
581d4e28 1895config FAIL_IO_TIMEOUT
f4d01439 1896 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1897 depends on FAULT_INJECTION && BLOCK
1898 help
1899 Provide fault-injection capability on end IO handling. This
1900 will make the block layer "forget" an interrupt as configured,
1901 thus exercising the error handling.
1902
1903 Only works with drivers that use the generic timeout handling,
9dbbc3b9 1904 for others it won't do anything.
581d4e28 1905
ab51fbab
DB
1906config FAIL_FUTEX
1907 bool "Fault-injection capability for futexes"
1908 select DEBUG_FS
1909 depends on FAULT_INJECTION && FUTEX
1910 help
1911 Provide fault-injection capability for futexes.
1912
f1b4bd06
MP
1913config FAULT_INJECTION_DEBUG_FS
1914 bool "Debugfs entries for fault-injection capabilities"
1915 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1916 help
1917 Enable configuration of fault-injection capabilities via debugfs.
1918
4b1a29a7
MH
1919config FAIL_FUNCTION
1920 bool "Fault-injection capability for functions"
1921 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1922 help
1923 Provide function-based fault-injection capability.
1924 This will allow you to override a specific function with a return
1925 with given return value. As a result, function caller will see
1926 an error value and have to handle it. This is useful to test the
1927 error handling in various subsystems.
1928
f1b4bd06
MP
1929config FAIL_MMC_REQUEST
1930 bool "Fault-injection capability for MMC IO"
1931 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1932 help
f1b4bd06
MP
1933 Provide fault-injection capability for MMC IO.
1934 This will make the mmc core return data errors. This is
1935 useful to test the error handling in the mmc block device
1936 and to test how the mmc host driver handles retries from
1937 the block device.
1df49008 1938
c782af25
CL
1939config FAIL_SUNRPC
1940 bool "Fault-injection capability for SunRPC"
1941 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
1942 help
1943 Provide fault-injection capability for SunRPC and
1944 its consumers.
1945
1df49008
AM
1946config FAULT_INJECTION_STACKTRACE_FILTER
1947 bool "stacktrace filter for fault-injection capabilities"
1948 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 1949 depends on !X86_64
1df49008 1950 select STACKTRACE
7d37cb2c 1951 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1df49008
AM
1952 help
1953 Provide stacktrace filter for fault-injection capabilities
267c4025 1954
09a74952
CD
1955config ARCH_HAS_KCOV
1956 bool
cc3fa840 1957 help
09a74952
CD
1958 An architecture should select this when it can successfully
1959 build and run with CONFIG_KCOV. This typically requires
1960 disabling instrumentation for some early boot code.
cc3fa840 1961
09a74952
CD
1962config CC_HAS_SANCOV_TRACE_PC
1963 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 1964
cc3fa840 1965
09a74952
CD
1966config KCOV
1967 bool "Code coverage for fuzzing"
1968 depends on ARCH_HAS_KCOV
1969 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
22102f45 1970 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
bece04b5 1971 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
09a74952
CD
1972 select DEBUG_FS
1973 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
22102f45 1974 select OBJTOOL if HAVE_NOINSTR_HACK
09a74952
CD
1975 help
1976 KCOV exposes kernel code coverage information in a form suitable
1977 for coverage-guided fuzzing (randomized testing).
cc3fa840 1978
09a74952
CD
1979 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1980 different machines and across reboots. If you need stable PC values,
1981 disable RANDOMIZE_BASE.
cc3fa840 1982
09a74952 1983 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 1984
09a74952
CD
1985config KCOV_ENABLE_COMPARISONS
1986 bool "Enable comparison operands collection by KCOV"
1987 depends on KCOV
1988 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1989 help
1990 KCOV also exposes operands of every comparison in the instrumented
1991 code along with operand sizes and PCs of the comparison instructions.
1992 These operands can be used by fuzzing engines to improve the quality
1993 of fuzzing coverage.
cc3fa840 1994
09a74952
CD
1995config KCOV_INSTRUMENT_ALL
1996 bool "Instrument all code by default"
1997 depends on KCOV
1998 default y
1999 help
2000 If you are doing generic system call fuzzing (like e.g. syzkaller),
2001 then you will want to instrument the whole kernel and you should
2002 say y here. If you are doing more targeted fuzzing (like e.g.
2003 filesystem fuzzing with AFL) then you will want to enable coverage
2004 for more specific subsets of files, and should say n here.
84bc809e 2005
5ff3b30a
AK
2006config KCOV_IRQ_AREA_SIZE
2007 hex "Size of interrupt coverage collection area in words"
2008 depends on KCOV
2009 default 0x40000
2010 help
2011 KCOV uses preallocated per-cpu areas to collect coverage from
2012 soft interrupts. This specifies the size of those areas in the
2013 number of unsigned long words.
2014
d3deafaa
VL
2015menuconfig RUNTIME_TESTING_MENU
2016 bool "Runtime Testing"
908009e8 2017 def_bool y
d3deafaa
VL
2018
2019if RUNTIME_TESTING_MENU
881c5149
DH
2020
2021config LKDTM
2022 tristate "Linux Kernel Dump Test Tool Module"
2023 depends on DEBUG_FS
881c5149
DH
2024 help
2025 This module enables testing of the different dumping mechanisms by
2026 inducing system failures at predefined crash points.
2027 If you don't need it: say N
2028 Choose M here to compile this code as a module. The module will be
2029 called lkdtm.
2030
2031 Documentation on how to use the module can be found in
10ffebbe 2032 Documentation/fault-injection/provoke-crashes.rst
881c5149 2033
d3c0ca49
SV
2034config CPUMASK_KUNIT_TEST
2035 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
c41e8866
SV
2036 depends on KUNIT
2037 default KUNIT_ALL_TESTS
2038 help
2039 Enable to turn on cpumask tests, running at boot or module load time.
2040
d3c0ca49
SV
2041 For more information on KUnit and unit tests in general, please refer
2042 to the KUnit documentation in Documentation/dev-tools/kunit/.
2043
c41e8866
SV
2044 If unsure, say N.
2045
881c5149 2046config TEST_LIST_SORT
ebd09577
DL
2047 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2048 depends on KUNIT
2049 default KUNIT_ALL_TESTS
881c5149
DH
2050 help
2051 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
2052 executed only once during system boot (so affects only boot time),
2053 or at module load time.
881c5149
DH
2054
2055 If unsure, say N.
2056
6e24628d
IR
2057config TEST_MIN_HEAP
2058 tristate "Min heap test"
2059 depends on DEBUG_KERNEL || m
2060 help
2061 Enable this to turn on min heap function tests. This test is
2062 executed only once during system boot (so affects only boot time),
2063 or at module load time.
2064
2065 If unsure, say N.
2066
c5adae95 2067config TEST_SORT
36f33b56
DL
2068 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2069 depends on KUNIT
2070 default KUNIT_ALL_TESTS
c5adae95 2071 help
5c4e6798
GU
2072 This option enables the self-test function of 'sort()' at boot,
2073 or at module load time.
c5adae95
KF
2074
2075 If unsure, say N.
2076
5086ea4b
MR
2077config TEST_DIV64
2078 tristate "64bit/32bit division and modulo test"
2079 depends on DEBUG_KERNEL || m
2080 help
2081 Enable this to turn on 'do_div()' function test. This test is
2082 executed only once during system boot (so affects only boot time),
2083 or at module load time.
2084
2085 If unsure, say N.
2086
881c5149 2087config KPROBES_SANITY_TEST
dcbb2ee2 2088 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
881c5149
DH
2089 depends on DEBUG_KERNEL
2090 depends on KPROBES
e44e81c5 2091 depends on KUNIT
dcbb2ee2 2092 default KUNIT_ALL_TESTS
881c5149
DH
2093 help
2094 This option provides for testing basic kprobes functionality on
5a6cf77f 2095 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
2096 verified for functionality.
2097
2098 Say N if you are unsure.
2099
f4616fab
MH
2100config FPROBE_SANITY_TEST
2101 bool "Self test for fprobe"
2102 depends on DEBUG_KERNEL
2103 depends on FPROBE
2104 depends on KUNIT=y
2105 help
2106 This option will enable testing the fprobe when the system boot.
2107 A series of tests are made to verify that the fprobe is functioning
2108 properly.
2109
2110 Say N if you are unsure.
2111
881c5149
DH
2112config BACKTRACE_SELF_TEST
2113 tristate "Self test for the backtrace code"
2114 depends on DEBUG_KERNEL
881c5149
DH
2115 help
2116 This option provides a kernel module that can be used to test
2117 the kernel stack backtrace code. This option is not useful
2118 for distributions or general kernels, but only for kernel
2119 developers working on architecture code.
2120
2121 Note that if you want to also test saved backtraces, you will
2122 have to enable STACKTRACE as well.
2123
2124 Say N if you are unsure.
2125
914a7b50
ED
2126config TEST_REF_TRACKER
2127 tristate "Self test for reference tracker"
2128 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2129 select REF_TRACKER
2130 help
2131 This option provides a kernel module performing tests
2132 using reference tracker infrastructure.
2133
2134 Say N if you are unsure.
2135
910a742d
ML
2136config RBTREE_TEST
2137 tristate "Red-Black tree test"
7c993e11 2138 depends on DEBUG_KERNEL
910a742d
ML
2139 help
2140 A benchmark measuring the performance of the rbtree library.
2141 Also includes rbtree invariant checks.
2142
4b4f3acc
FB
2143config REED_SOLOMON_TEST
2144 tristate "Reed-Solomon library test"
2145 depends on DEBUG_KERNEL || m
2146 select REED_SOLOMON
2147 select REED_SOLOMON_ENC16
2148 select REED_SOLOMON_DEC16
2149 help
2150 This option enables the self-test function of rslib at boot,
2151 or at module load time.
2152
2153 If unsure, say N.
2154
fff3fd8a
ML
2155config INTERVAL_TREE_TEST
2156 tristate "Interval tree test"
0f789b67 2157 depends on DEBUG_KERNEL
a88cc108 2158 select INTERVAL_TREE
fff3fd8a
ML
2159 help
2160 A benchmark measuring the performance of the interval tree library
2161
623fd807
GT
2162config PERCPU_TEST
2163 tristate "Per cpu operations test"
2164 depends on m && DEBUG_KERNEL
2165 help
2166 Enable this option to build test module which validates per-cpu
2167 operations.
2168
2169 If unsure, say N.
2170
881c5149 2171config ATOMIC64_SELFTEST
55ded955 2172 tristate "Perform an atomic64_t self-test"
881c5149 2173 help
55ded955
GU
2174 Enable this option to test the atomic64_t functions at boot or
2175 at module load time.
881c5149
DH
2176
2177 If unsure, say N.
2178
2179config ASYNC_RAID6_TEST
2180 tristate "Self test for hardware accelerated raid6 recovery"
2181 depends on ASYNC_RAID6_RECOV
2182 select ASYNC_MEMCPY
a7f7f624 2183 help
881c5149
DH
2184 This is a one-shot self test that permutes through the
2185 recovery of all the possible two disk failure scenarios for a
2186 N-disk array. Recovery is performed with the asynchronous
2187 raid6 recovery routines, and will optionally use an offload
2188 engine if one is available.
2189
2190 If unsure, say N.
2191
64d1d77a
AS
2192config TEST_HEXDUMP
2193 tristate "Test functions located in the hexdump module at runtime"
2194
b2ff70a0
MC
2195config STRING_SELFTEST
2196 tristate "Test string functions at runtime"
2197
881c5149
DH
2198config TEST_STRING_HELPERS
2199 tristate "Test functions located in the string_helpers module at runtime"
2200
0b0600c8
TH
2201config TEST_STRSCPY
2202 tristate "Test strscpy*() family of functions at runtime"
2203
881c5149
DH
2204config TEST_KSTRTOX
2205 tristate "Test kstrto*() family of functions at runtime"
2206
707cc728
RV
2207config TEST_PRINTF
2208 tristate "Test printf() family of functions at runtime"
2209
50f530e1
RF
2210config TEST_SCANF
2211 tristate "Test scanf() family of functions at runtime"
2212
5fd003f5
DD
2213config TEST_BITMAP
2214 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2215 help
2216 Enable this option to test the bitmap functions at boot.
2217
2218 If unsure, say N.
2219
cfaff0e5
AS
2220config TEST_UUID
2221 tristate "Test functions located in the uuid module at runtime"
2222
ad3d6c72
MW
2223config TEST_XARRAY
2224 tristate "Test the XArray code at runtime"
2225
7e1e7763 2226config TEST_RHASHTABLE
9d6dbe1b 2227 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2228 help
2229 Enable this option to test the rhashtable functions at boot.
2230
2231 If unsure, say N.
2232
88168bf3
IB
2233config TEST_SIPHASH
2234 tristate "Perform selftest on siphash functions"
468a9428 2235 help
88168bf3
IB
2236 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2237 functions on boot (or module load).
468a9428
GS
2238
2239 This is intended to help people writing architecture-specific
2240 optimized versions. If unsure, say N.
2241
8ab8ba38
MW
2242config TEST_IDA
2243 tristate "Perform selftest on IDA functions"
2244
44091d29
JP
2245config TEST_PARMAN
2246 tristate "Perform selftest on priority array manager"
44091d29
JP
2247 depends on PARMAN
2248 help
2249 Enable this option to test priority array manager on boot
2250 (or module load).
2251
2252 If unsure, say N.
2253
6aed82de
DL
2254config TEST_IRQ_TIMINGS
2255 bool "IRQ timings selftest"
2256 depends on IRQ_TIMINGS
2257 help
2258 Enable this option to test the irq timings code on boot.
2259
2260 If unsure, say N.
2261
8a6f0b47 2262config TEST_LKM
93e9ef83 2263 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2264 depends on m
2265 help
2266 This builds the "test_module" module that emits "Hello, world"
2267 on printk when loaded. It is designed to be used for basic
2268 evaluation of the module loading subsystem (for example when
2269 validating module verification). It lacks any extra dependencies,
2270 and will not normally be loaded by the system unless explicitly
2271 requested by name.
2272
2273 If unsure, say N.
2274
c348c163 2275config TEST_BITOPS
6af132f3 2276 tristate "Test module for compilation of bitops operations"
c348c163
JB
2277 depends on m
2278 help
2279 This builds the "test_bitops" module that is much like the
2280 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2281 set/clear_bit macros and get_count_order/long to make sure there are
2282 no compiler warnings from C=1 sparse checker or -Wextra
2283 compilations. It has no dependencies and doesn't run or load unless
2284 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2285
2286 If unsure, say N.
2287
3f21a6b7
URS
2288config TEST_VMALLOC
2289 tristate "Test module for stress/performance analysis of vmalloc allocator"
2290 default n
2291 depends on MMU
2292 depends on m
2293 help
2294 This builds the "test_vmalloc" module that should be used for
2295 stress and performance analysis. So, any new change for vmalloc
2296 subsystem can be evaluated from performance and stability point
2297 of view.
2298
2299 If unsure, say N.
2300
3e2a4c18
KC
2301config TEST_USER_COPY
2302 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2303 depends on m
2304 help
2305 This builds the "test_user_copy" module that runs sanity checks
2306 on the copy_to/from_user infrastructure, making sure basic
2307 user/kernel boundary testing is working. If it fails to load,
2308 a regression has been detected in the user/kernel memory boundary
2309 protections.
2310
2311 If unsure, say N.
2312
64a8946b
AS
2313config TEST_BPF
2314 tristate "Test BPF filter functionality"
98920ba6 2315 depends on m && NET
64a8946b
AS
2316 help
2317 This builds the "test_bpf" module that runs various test vectors
2318 against the BPF interpreter or BPF JIT compiler depending on the
2319 current setting. This is in particular useful for BPF JIT compiler
2320 development, but also to run regression tests against changes in
3c731eba
AS
2321 the interpreter code. It also enables test stubs for eBPF maps and
2322 verifier used by user space verifier testsuite.
64a8946b
AS
2323
2324 If unsure, say N.
2325
509e56b3
MB
2326config TEST_BLACKHOLE_DEV
2327 tristate "Test blackhole netdev functionality"
2328 depends on m && NET
2329 help
2330 This builds the "test_blackhole_dev" module that validates the
2331 data path through this blackhole netdev.
2332
2333 If unsure, say N.
2334
dceeb3e7 2335config FIND_BIT_BENCHMARK
4441fca0 2336 tristate "Test find_bit functions"
4441fca0
YN
2337 help
2338 This builds the "test_find_bit" module that measure find_*_bit()
2339 functions performance.
2340
2341 If unsure, say N.
2342
0a8adf58
KC
2343config TEST_FIRMWARE
2344 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2345 depends on FW_LOADER
2346 help
2347 This builds the "test_firmware" module that creates a userspace
2348 interface for testing firmware loading. This can be used to
2349 control the triggering of firmware loading without needing an
2350 actual firmware-using device. The contents can be rechecked by
2351 userspace.
2352
2353 If unsure, say N.
2354
9308f2f9
LR
2355config TEST_SYSCTL
2356 tristate "sysctl test driver"
9308f2f9
LR
2357 depends on PROC_SYSCTL
2358 help
2359 This builds the "test_sysctl" module. This driver enables to test the
2360 proc sysctl interfaces available to drivers safely without affecting
2361 production knobs which might alter system functionality.
2362
2363 If unsure, say N.
2364
d2585f51 2365config BITFIELD_KUNIT
dcbb2ee2 2366 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
d2585f51 2367 depends on KUNIT
dcbb2ee2 2368 default KUNIT_ALL_TESTS
d2585f51
VMI
2369 help
2370 Enable this option to test the bitfield functions at boot.
2371
2372 KUnit tests run during boot and output the results to the debug log
2373 in TAP format (http://testanything.org/). Only useful for kernel devs
2374 running the KUnit test harness, and not intended for inclusion into a
2375 production build.
2376
2377 For more information on KUnit and unit tests in general please refer
2378 to the KUnit documentation in Documentation/dev-tools/kunit/.
2379
2380 If unsure, say N.
2381
0acc968f
IB
2382config HASH_KUNIT_TEST
2383 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2384 depends on KUNIT
2385 default KUNIT_ALL_TESTS
2386 help
2387 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2388 integer (<linux/hash.h>) hash functions on boot.
2389
2390 KUnit tests run during boot and output the results to the debug log
2391 in TAP format (https://testanything.org/). Only useful for kernel devs
2392 running the KUnit test harness, and not intended for inclusion into a
2393 production build.
2394
2395 For more information on KUnit and unit tests in general please refer
2396 to the KUnit documentation in Documentation/dev-tools/kunit/.
2397
2398 This is intended to help people writing architecture-specific
2399 optimized versions. If unsure, say N.
2400
5df38ca6 2401config RESOURCE_KUNIT_TEST
dcbb2ee2 2402 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
5df38ca6 2403 depends on KUNIT
dcbb2ee2 2404 default KUNIT_ALL_TESTS
5df38ca6
AS
2405 help
2406 This builds the resource API unit test.
2407 Tests the logic of API provided by resource.c and ioport.h.
2408 For more information on KUnit and unit tests in general please refer
2409 to the KUnit documentation in Documentation/dev-tools/kunit/.
2410
2411 If unsure, say N.
2412
2cb80dbb 2413config SYSCTL_KUNIT_TEST
5f215aab 2414 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2415 depends on KUNIT
5f215aab 2416 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2417 help
2418 This builds the proc sysctl unit test, which runs on boot.
2419 Tests the API contract and implementation correctness of sysctl.
2420 For more information on KUnit and unit tests in general please refer
2421 to the KUnit documentation in Documentation/dev-tools/kunit/.
2422
2423 If unsure, say N.
2424
ea2dd7c0 2425config LIST_KUNIT_TEST
5f215aab 2426 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2427 depends on KUNIT
5f215aab 2428 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2429 help
2430 This builds the linked list KUnit test suite.
2431 It tests that the API and basic functionality of the list_head type
2432 and associated macros.
2433
2434 KUnit tests run during boot and output the results to the debug log
d89775fc 2435 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2436 running the KUnit test harness, and not intended for inclusion into a
2437 production build.
2438
2439 For more information on KUnit and unit tests in general please refer
2440 to the KUnit documentation in Documentation/dev-tools/kunit/.
2441
2442 If unsure, say N.
2443
33d599f0
MV
2444config LINEAR_RANGES_TEST
2445 tristate "KUnit test for linear_ranges"
2446 depends on KUNIT
2447 select LINEAR_RANGES
2448 help
2449 This builds the linear_ranges unit test, which runs on boot.
2450 Tests the linear_ranges logic correctness.
2451 For more information on KUnit and unit tests in general please refer
7546861a
AS
2452 to the KUnit documentation in Documentation/dev-tools/kunit/.
2453
2454 If unsure, say N.
2455
2456config CMDLINE_KUNIT_TEST
dcbb2ee2 2457 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
7546861a 2458 depends on KUNIT
dcbb2ee2 2459 default KUNIT_ALL_TESTS
7546861a
AS
2460 help
2461 This builds the cmdline API unit test.
2462 Tests the logic of API provided by cmdline.c.
2463 For more information on KUnit and unit tests in general please refer
33d599f0
MV
2464 to the KUnit documentation in Documentation/dev-tools/kunit/.
2465
2466 If unsure, say N.
2467
6d511020 2468config BITS_TEST
dcbb2ee2 2469 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
6d511020 2470 depends on KUNIT
dcbb2ee2 2471 default KUNIT_ALL_TESTS
6d511020
RF
2472 help
2473 This builds the bits unit test.
2474 Tests the logic of macros defined in bits.h.
2475 For more information on KUnit and unit tests in general please refer
2476 to the KUnit documentation in Documentation/dev-tools/kunit/.
2477
2478 If unsure, say N.
2479
1f9f78b1
OG
2480config SLUB_KUNIT_TEST
2481 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2482 depends on SLUB_DEBUG && KUNIT
2483 default KUNIT_ALL_TESTS
2484 help
2485 This builds SLUB allocator unit test.
2486 Tests SLUB cache debugging functionality.
2487 For more information on KUnit and unit tests in general please refer
2488 to the KUnit documentation in Documentation/dev-tools/kunit/.
2489
2490 If unsure, say N.
2491
b6c75c4a
TP
2492config RATIONAL_KUNIT_TEST
2493 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
8ba739ed 2494 depends on KUNIT && RATIONAL
b6c75c4a
TP
2495 default KUNIT_ALL_TESTS
2496 help
2497 This builds the rational math unit test.
2498 For more information on KUnit and unit tests in general please refer
2499 to the KUnit documentation in Documentation/dev-tools/kunit/.
2500
2501 If unsure, say N.
2502
bb95ebbe
KC
2503config MEMCPY_KUNIT_TEST
2504 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2505 depends on KUNIT
2506 default KUNIT_ALL_TESTS
2507 help
2508 Builds unit tests for memcpy(), memmove(), and memset() functions.
2509 For more information on KUnit and unit tests in general please refer
2510 to the KUnit documentation in Documentation/dev-tools/kunit/.
2511
2512 If unsure, say N.
2513
617f55e2
KC
2514config OVERFLOW_KUNIT_TEST
2515 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2516 depends on KUNIT
2517 default KUNIT_ALL_TESTS
2518 help
2519 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2520 related functions.
2521
2522 For more information on KUnit and unit tests in general please refer
2523 to the KUnit documentation in Documentation/dev-tools/kunit/.
2524
2525 If unsure, say N.
2526
02788ebc
KC
2527config STACKINIT_KUNIT_TEST
2528 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2529 depends on KUNIT
2530 default KUNIT_ALL_TESTS
2531 help
2532 Test if the kernel is zero-initializing stack variables and
2533 padding. Coverage is controlled by compiler flags,
2534 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2535 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2536 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2537
e704f93a
DR
2538config TEST_UDELAY
2539 tristate "udelay test driver"
e704f93a
DR
2540 help
2541 This builds the "udelay_test" module that helps to make sure
2542 that udelay() is working properly.
2543
2544 If unsure, say N.
2545
2bf9e0ab
IM
2546config TEST_STATIC_KEYS
2547 tristate "Test static keys"
579e1acb
JB
2548 depends on m
2549 help
2bf9e0ab 2550 Test the static key interfaces.
579e1acb
JB
2551
2552 If unsure, say N.
2553
d9c6a72d
LR
2554config TEST_KMOD
2555 tristate "kmod stress tester"
d9c6a72d 2556 depends on m
d9c6a72d 2557 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2558 depends on BLOCK
bbd2e05f 2559 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
d9c6a72d
LR
2560 select TEST_LKM
2561 select XFS_FS
2562 select TUN
2563 select BTRFS_FS
2564 help
2565 Test the kernel's module loading mechanism: kmod. kmod implements
2566 support to load modules using the Linux kernel's usermode helper.
2567 This test provides a series of tests against kmod.
2568
2569 Although technically you can either build test_kmod as a module or
2570 into the kernel we disallow building it into the kernel since
2571 it stress tests request_module() and this will very likely cause
2572 some issues by taking over precious threads available from other
2573 module load requests, ultimately this could be fatal.
2574
2575 To run tests run:
2576
2577 tools/testing/selftests/kmod/kmod.sh --help
2578
2579 If unsure, say N.
2580
e4dace36
FF
2581config TEST_DEBUG_VIRTUAL
2582 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2583 depends on DEBUG_VIRTUAL
2584 help
2585 Test the kernel's ability to detect incorrect calls to
2586 virt_to_phys() done against the non-linear part of the
2587 kernel's virtual address map.
2588
2589 If unsure, say N.
2590
ce76d938
AS
2591config TEST_MEMCAT_P
2592 tristate "Test memcat_p() helper function"
2593 help
2594 Test the memcat_p() helper for correctly merging two
2595 pointer arrays together.
2596
2597 If unsure, say N.
2598
a2818ee4
JL
2599config TEST_LIVEPATCH
2600 tristate "Test livepatching"
2601 default n
bae05437 2602 depends on DYNAMIC_DEBUG
a2818ee4
JL
2603 depends on LIVEPATCH
2604 depends on m
2605 help
2606 Test kernel livepatching features for correctness. The tests will
2607 load test modules that will be livepatched in various scenarios.
2608
2609 To run all the livepatching tests:
2610
2611 make -C tools/testing/selftests TARGETS=livepatch run_tests
2612
2613 Alternatively, individual tests may be invoked:
2614
2615 tools/testing/selftests/livepatch/test-callbacks.sh
2616 tools/testing/selftests/livepatch/test-livepatch.sh
2617 tools/testing/selftests/livepatch/test-shadow-vars.sh
2618
2619 If unsure, say N.
2620
0a020d41
JP
2621config TEST_OBJAGG
2622 tristate "Perform selftest on object aggreration manager"
2623 default n
2624 depends on OBJAGG
2625 help
2626 Enable this option to test object aggregation manager on boot
2627 (or module load).
2628
5015a300
AP
2629config TEST_MEMINIT
2630 tristate "Test heap/page initialization"
2631 help
2632 Test if the kernel is zero-initializing heap and page allocations.
2633 This can be useful to test init_on_alloc and init_on_free features.
2634
2635 If unsure, say N.
2636
b2ef9f5a
RC
2637config TEST_HMM
2638 tristate "Test HMM (Heterogeneous Memory Management)"
2639 depends on TRANSPARENT_HUGEPAGE
2640 depends on DEVICE_PRIVATE
2641 select HMM_MIRROR
2642 select MMU_NOTIFIER
2643 help
2644 This is a pseudo device driver solely for testing HMM.
2645 Say M here if you want to build the HMM test module.
2646 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2647
2648 If unsure, say N.
2649
e320d301
MWO
2650config TEST_FREE_PAGES
2651 tristate "Test freeing pages"
2652 help
2653 Test that a memory leak does not occur due to a race between
2654 freeing a block of pages and a speculative page reference.
2655 Loading this module is safe if your kernel has the bug fixed.
2656 If the bug is not fixed, it will leak gigabytes of memory and
2657 probably OOM your system.
2658
4185b3b9
PA
2659config TEST_FPU
2660 tristate "Test floating point operations in kernel space"
2661 depends on X86 && !KCOV_INSTRUMENT_ALL
2662 help
2663 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2664 which will trigger a sequence of floating point operations. This is used
2665 for self-testing floating point control register setting in
2666 kernel_fpu_begin().
2667
2668 If unsure, say N.
2669
1253b9b8
PM
2670config TEST_CLOCKSOURCE_WATCHDOG
2671 tristate "Test clocksource watchdog in kernel space"
2672 depends on CLOCKSOURCE_WATCHDOG
2673 help
2674 Enable this option to create a kernel module that will trigger
2675 a test of the clocksource watchdog. This module may be loaded
2676 via modprobe or insmod in which case it will run upon being
2677 loaded, or it may be built in, in which case it will run
2678 shortly after boot.
2679
2680 If unsure, say N.
2681
d3deafaa 2682endif # RUNTIME_TESTING_MENU
cc3fa840 2683
dce44566
AK
2684config ARCH_USE_MEMTEST
2685 bool
2686 help
2687 An architecture should select this when it uses early_memtest()
2688 during boot process.
2689
cc3fa840
RD
2690config MEMTEST
2691 bool "Memtest"
dce44566 2692 depends on ARCH_USE_MEMTEST
a7f7f624 2693 help
cc3fa840 2694 This option adds a kernel parameter 'memtest', which allows memtest
dce44566 2695 to be set and executed.
cc3fa840
RD
2696 memtest=0, mean disabled; -- default
2697 memtest=1, mean do 1 test pattern;
2698 ...
2699 memtest=17, mean do 17 test patterns.
2700 If you are unsure how to answer this question, answer N.
2701
21266be9 2702
06ec64b8 2703
af9ca6f9
BB
2704config HYPERV_TESTING
2705 bool "Microsoft Hyper-V driver testing"
2706 default n
2707 depends on HYPERV && DEBUG_FS
2708 help
2709 Select this option to enable Hyper-V vmbus testing.
2710
045f6d79
CD
2711endmenu # "Kernel Testing and Coverage"
2712
75442fb0
MCC
2713source "Documentation/Kconfig"
2714
06ec64b8 2715endmenu # Kernel hacking