kbuild: check the minimum assembler version in Kconfig
[linux-2.6-block.git] / lib / Kconfig.debug
CommitLineData
ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
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21config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
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38config CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
40 range 1 15
41 default "7"
42 help
43 Default loglevel to determine what will be printed on the console.
44
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
48
50f4d9bd 49 Note: This does not affect the log level of un-prefixed printk()
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50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
51 option.
52
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53config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
55 range 1 15
56 default "4"
57 help
58 loglevel to use when "quiet" is passed on the kernel commandline.
59
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
63
42a9dc0b 64config MESSAGE_LOGLEVEL_DEFAULT
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65 int "Default message log level (1-7)"
66 range 1 7
67 default "4"
68 help
69 Default log level for printk statements with no specified priority.
70
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
73 priority.
74
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75 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
78
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79config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
82 help
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
86 using "boot_delay=N".
87
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
96
97config DYNAMIC_DEBUG
98 bool "Enable dynamic printk() support"
99 default n
100 depends on PRINTK
239a5791 101 depends on (DEBUG_FS || PROC_FS)
ceabef7d 102 select DYNAMIC_DEBUG_CORE
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103 help
104
105 Compiles debug level messages into the kernel, which would not
106 otherwise be available at runtime. These messages can then be
107 enabled/disabled based on various levels of scope - per source file,
108 function, module, format string, and line number. This mechanism
109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
110 enlarges the kernel text size by about 2%.
111
112 If a source file is compiled with DEBUG flag set, any
113 pr_debug() calls in it are enabled by default, but can be
114 disabled at runtime as below. Note that DEBUG flag is
115 turned on by many CONFIG_*DEBUG* options.
116
117 Usage:
118
119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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120 which is contained in the 'debugfs' filesystem or procfs.
121 Thus, the debugfs or procfs filesystem must first be mounted before
122 making use of this feature.
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123 We refer the control file as: <debugfs>/dynamic_debug/control. This
124 file contains a list of the debug statements that can be enabled. The
125 format for each line of the file is:
126
127 filename:lineno [module]function flags format
128
129 filename : source file of the debug statement
130 lineno : line number of the debug statement
131 module : module that contains the debug statement
132 function : function that contains the debug statement
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133 flags : '=p' means the line is turned 'on' for printing
134 format : the format used for the debug statement
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135
136 From a live system:
137
138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
139 # filename:lineno [module]function flags format
140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
143
144 Example usage:
145
146 // enable the message at line 1603 of file svcsock.c
147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
148 <debugfs>/dynamic_debug/control
149
150 // enable all the messages in file svcsock.c
151 nullarbor:~ # echo -n 'file svcsock.c +p' >
152 <debugfs>/dynamic_debug/control
153
154 // enable all the messages in the NFS server module
155 nullarbor:~ # echo -n 'module nfsd +p' >
156 <debugfs>/dynamic_debug/control
157
158 // enable all 12 messages in the function svc_process()
159 nullarbor:~ # echo -n 'func svc_process +p' >
160 <debugfs>/dynamic_debug/control
161
162 // disable all 12 messages in the function svc_process()
163 nullarbor:~ # echo -n 'func svc_process -p' >
164 <debugfs>/dynamic_debug/control
165
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166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
167 information.
604ff0dc 168
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169config DYNAMIC_DEBUG_CORE
170 bool "Enable core function of dynamic debug support"
171 depends on PRINTK
172 depends on (DEBUG_FS || PROC_FS)
173 help
174 Enable core functional support of dynamic debug. It is useful
175 when you want to tie dynamic debug to your kernel modules with
176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
177 the case of embedded system where the kernel image size is
178 sensitive for people.
179
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180config SYMBOLIC_ERRNAME
181 bool "Support symbolic error names in printf"
182 default y if PRINTK
183 help
184 If you say Y here, the kernel's printf implementation will
185 be able to print symbolic error names such as ENOSPC instead
186 of the number 28. It makes the kernel image slightly larger
187 (about 3KB), but can make the kernel logs easier to read.
188
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189config DEBUG_BUGVERBOSE
190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
192 default y
193 help
194 Say Y here to make BUG() panics output the file name and line number
195 of the BUG call as well as the EIP and oops trace. This aids
196 debugging but costs about 70-100K of memory.
197
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198endmenu # "printk and dmesg options"
199
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200menu "Compile-time checks and compiler options"
201
202config DEBUG_INFO
203 bool "Compile the kernel with debug info"
12b13835 204 depends on DEBUG_KERNEL && !COMPILE_TEST
6dfc0665 205 help
68d4b3df 206 If you say Y here the resulting kernel image will include
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207 debugging info resulting in a larger kernel image.
208 This adds debug symbols to the kernel and modules (gcc -g), and
209 is needed if you intend to use kernel crashdump or binary object
210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
211 Say Y here only if you plan to debug the kernel.
212
213 If unsure, say N.
214
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215if DEBUG_INFO
216
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217config DEBUG_INFO_REDUCED
218 bool "Reduce debugging information"
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219 help
220 If you say Y here gcc is instructed to generate less debugging
221 information for structure types. This means that tools that
222 need full debugging information (like kgdb or systemtap) won't
223 be happy. But if you merely need debugging information to
224 resolve line numbers there is no loss. Advantage is that
225 build directory object sizes shrink dramatically over a full
226 DEBUG_INFO build and compile times are reduced too.
227 Only works with newer gcc versions.
228
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229config DEBUG_INFO_COMPRESSED
230 bool "Compressed debugging information"
10e68b02 231 depends on $(cc-option,-gz=zlib)
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232 depends on $(ld-option,--compress-debug-sections=zlib)
233 help
234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
235 5.0+, binutils 2.26+, and zlib.
236
237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
238 size of their debug .deb packages with this config set, due to the
239 debug info being compressed with zlib, then the object files being
240 recompressed with a different compression scheme. But this is still
241 preferable to setting $KDEB_COMPRESS to "none" which would be even
242 larger.
243
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244config DEBUG_INFO_SPLIT
245 bool "Produce split debuginfo in .dwo files"
9d937444 246 depends on $(cc-option,-gsplit-dwarf)
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247 help
248 Generate debug info into separate .dwo files. This significantly
249 reduces the build directory size for builds with DEBUG_INFO,
250 because it stores the information only once on disk in .dwo
251 files instead of multiple times in object files and executables.
252 In addition the debug information is also compressed.
253
254 Requires recent gcc (4.7+) and recent gdb/binutils.
255 Any tool that packages or reads debug information would need
256 to know about the .dwo files and include them.
257 Incompatible with older versions of ccache.
258
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259choice
260 prompt "DWARF version"
261 help
262 Which version of DWARF debug info to emit.
263
264config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
265 bool "Rely on the toolchain's implicit default DWARF version"
266 help
267 The implicit default version of DWARF debug info produced by a
268 toolchain changes over time.
269
270 This can break consumers of the debug info that haven't upgraded to
271 support newer revisions, and prevent testing newer versions, but
272 those should be less common scenarios.
273
274 If unsure, say Y.
275
bfaf2dd3 276config DEBUG_INFO_DWARF4
a66049e2 277 bool "Generate DWARF Version 4 debuginfo"
bfaf2dd3 278 help
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279 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
280
281 If you have consumers of DWARF debug info that are not ready for
282 newer revisions of DWARF, you may wish to choose this or have your
283 config select this.
284
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285config DEBUG_INFO_DWARF5
286 bool "Generate DWARF Version 5 debuginfo"
287 depends on GCC_VERSION >= 50000 || CC_IS_CLANG
288 depends on CC_IS_GCC || $(success,$(srctree)/scripts/test_dwarf5_support.sh $(CC) $(CLANG_FLAGS))
289 depends on !DEBUG_INFO_BTF
bfaf2dd3 290 help
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291 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
292 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
293 draft features until 7.0), and gdb 8.0+.
294
295 Changes to the structure of debug info in Version 5 allow for around
296 15-18% savings in resulting image and debug info section sizes as
297 compared to DWARF Version 4. DWARF Version 5 standardizes previous
298 extensions such as accelerators for symbol indexing and the format
299 for fission (.dwo/.dwp) files. Users may not want to select this
300 config if they rely on tooling that has not yet been updated to
301 support DWARF Version 5.
302
a66049e2 303endchoice # "DWARF version"
bfaf2dd3 304
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305config DEBUG_INFO_BTF
306 bool "Generate BTF typeinfo"
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307 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
308 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
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309 help
310 Generate deduplicated BTF type information from DWARF debug info.
311 Turning this on expects presence of pahole tool, which will convert
312 DWARF type info into equivalent deduplicated BTF type info.
313
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314config PAHOLE_HAS_SPLIT_BTF
315 def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119")
316
317config DEBUG_INFO_BTF_MODULES
318 def_bool y
319 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
320 help
321 Generate compact split BTF type information for kernel modules.
322
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323config GDB_SCRIPTS
324 bool "Provide GDB scripts for kernel debugging"
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325 help
326 This creates the required links to GDB helper scripts in the
327 build directory. If you load vmlinux into gdb, the helper
328 scripts will be automatically imported by gdb as well, and
329 additional functions are available to analyze a Linux kernel
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330 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
331 for further details.
3ee7b3fa 332
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333endif # DEBUG_INFO
334
35bb5b1e 335config FRAME_WARN
a83e4ca2 336 int "Warn for stack frames larger than"
35bb5b1e 337 range 0 8192
0e07f663 338 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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339 default 1280 if (!64BIT && PARISC)
340 default 1024 if (!64BIT && !PARISC)
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341 default 2048 if 64BIT
342 help
343 Tell gcc to warn at build time for stack frames larger than this.
344 Setting this too low will cause a lot of warnings.
345 Setting it to 0 disables the warning.
35bb5b1e 346
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347config STRIP_ASM_SYMS
348 bool "Strip assembler-generated symbols during link"
349 default n
350 help
351 Strip internal assembler-generated symbols during a link (symbols
352 that look like '.Lxxx') so they don't pollute the output of
353 get_wchan() and suchlike.
354
1873e870 355config READABLE_ASM
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356 bool "Generate readable assembler code"
357 depends on DEBUG_KERNEL
bf4735a4 358 help
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359 Disable some compiler optimizations that tend to generate human unreadable
360 assembler output. This may make the kernel slightly slower, but it helps
361 to keep kernel developers who have to stare a lot at assembler listings
362 sane.
bf4735a4 363
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364config HEADERS_INSTALL
365 bool "Install uapi headers to usr/include"
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366 depends on !UML
367 help
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368 This option will install uapi headers (headers exported to user-space)
369 into the usr/include directory for use during the kernel build.
370 This is unneeded for building the kernel itself, but needed for some
371 user-space program samples. It is also needed by some features such
372 as uapi header sanity checks.
373
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374config DEBUG_SECTION_MISMATCH
375 bool "Enable full Section mismatch analysis"
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376 help
377 The section mismatch analysis checks if there are illegal
378 references from one section to another section.
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379 During linktime or runtime, some sections are dropped;
380 any use of code/data previously in these sections would
91341d4b 381 most likely result in an oops.
e809ab01 382 In the code, functions and variables are annotated with
0db0628d 383 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 384 which results in the code/data being placed in specific sections.
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385 The section mismatch analysis is always performed after a full
386 kernel build, and enabling this option causes the following
b7dca6dd 387 additional step to occur:
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388 - Add the option -fno-inline-functions-called-once to gcc commands.
389 When inlining a function annotated with __init in a non-init
390 function, we would lose the section information and thus
91341d4b 391 the analysis would not catch the illegal reference.
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392 This option tells gcc to inline less (but it does result in
393 a larger kernel).
91341d4b 394
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395config SECTION_MISMATCH_WARN_ONLY
396 bool "Make section mismatch errors non-fatal"
397 default y
398 help
399 If you say N here, the build process will fail if there are any
400 section mismatch, instead of just throwing warnings.
401
402 If unsure, say Y.
403
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404config DEBUG_FORCE_FUNCTION_ALIGN_32B
405 bool "Force all function address 32B aligned" if EXPERT
406 help
407 There are cases that a commit from one domain changes the function
408 address alignment of other domains, and cause magic performance
409 bump (regression or improvement). Enable this option will help to
410 verify if the bump is caused by function alignment changes, while
411 it will slightly increase the kernel size and affect icache usage.
412
413 It is mainly for debug and performance tuning use.
414
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415#
416# Select this config option from the architecture Kconfig, if it
417# is preferred to always offer frame pointers as a config
418# option on the architecture (regardless of KERNEL_DEBUG):
419#
420config ARCH_WANT_FRAME_POINTERS
421 bool
f346f4b3 422
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423config FRAME_POINTER
424 bool "Compile the kernel with frame pointers"
a687a533 425 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 426 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 427 help
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428 If you say Y here the resulting kernel image will be slightly
429 larger and slower, but it gives very useful debugging information
430 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 431
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432config STACK_VALIDATION
433 bool "Compile-time stack metadata validation"
434 depends on HAVE_STACK_VALIDATION
435 default n
436 help
437 Add compile-time checks to validate stack metadata, including frame
438 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
439 that runtime stack traces are more reliable.
440
ee9f8fce 441 This is also a prerequisite for generation of ORC unwind data, which
11af8474 442 is needed for CONFIG_UNWINDER_ORC.
ee9f8fce 443
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444 For more information, see
445 tools/objtool/Documentation/stack-validation.txt.
446
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447config VMLINUX_VALIDATION
448 bool
449 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
450 default y
451
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452config VMLINUX_MAP
453 bool "Generate vmlinux.map file when linking"
454 depends on EXPERT
455 help
456 Selecting this option will pass "-Map=vmlinux.map" to ld
457 when linking vmlinux. That file can be useful for verifying
458 and debugging magic section games, and for seeing which
459 pieces of code get eliminated with
460 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
461
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462config DEBUG_FORCE_WEAK_PER_CPU
463 bool "Force weak per-cpu definitions"
464 depends on DEBUG_KERNEL
8446f1d3 465 help
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466 s390 and alpha require percpu variables in modules to be
467 defined weak to work around addressing range issue which
468 puts the following two restrictions on percpu variable
469 definitions.
8446f1d3 470
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471 1. percpu symbols must be unique whether static or not
472 2. percpu variables can't be defined inside a function
8446f1d3 473
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474 To ensure that generic code follows the above rules, this
475 option forces all percpu variables to be defined as weak.
5f329089 476
6dfc0665 477endmenu # "Compiler options"
8446f1d3 478
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479menu "Generic Kernel Debugging Instruments"
480
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481config MAGIC_SYSRQ
482 bool "Magic SysRq key"
483 depends on !UML
484 help
485 If you say Y here, you will have some control over the system even
486 if the system crashes for example during kernel debugging (e.g., you
487 will be able to flush the buffer cache to disk, reboot the system
488 immediately or dump some status information). This is accomplished
489 by pressing various keys while holding SysRq (Alt+PrintScreen). It
490 also works on a serial console (on PC hardware at least), if you
491 send a BREAK and then within 5 seconds a command keypress. The
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492 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
493 Don't say Y unless you really know what this hack does.
8446f1d3 494
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495config MAGIC_SYSRQ_DEFAULT_ENABLE
496 hex "Enable magic SysRq key functions by default"
497 depends on MAGIC_SYSRQ
498 default 0x1
499 help
500 Specifies which SysRq key functions are enabled by default.
501 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 502 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 503
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504config MAGIC_SYSRQ_SERIAL
505 bool "Enable magic SysRq key over serial"
506 depends on MAGIC_SYSRQ
507 default y
508 help
509 Many embedded boards have a disconnected TTL level serial which can
510 generate some garbage that can lead to spurious false sysrq detects.
511 This option allows you to decide whether you want to enable the
512 magic SysRq key.
513
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514config MAGIC_SYSRQ_SERIAL_SEQUENCE
515 string "Char sequence that enables magic SysRq over serial"
516 depends on MAGIC_SYSRQ_SERIAL
517 default ""
518 help
519 Specifies a sequence of characters that can follow BREAK to enable
520 SysRq on a serial console.
521
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522 If unsure, leave an empty string and the option will not be enabled.
523
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524config DEBUG_FS
525 bool "Debug Filesystem"
526 help
527 debugfs is a virtual file system that kernel developers use to put
528 debugging files into. Enable this option to be able to read and
529 write to these files.
530
531 For detailed documentation on the debugfs API, see
532 Documentation/filesystems/.
533
534 If unsure, say N.
535
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536choice
537 prompt "Debugfs default access"
538 depends on DEBUG_FS
539 default DEBUG_FS_ALLOW_ALL
540 help
541 This selects the default access restrictions for debugfs.
542 It can be overridden with kernel command line option
543 debugfs=[on,no-mount,off]. The restrictions apply for API access
544 and filesystem registration.
545
546config DEBUG_FS_ALLOW_ALL
547 bool "Access normal"
548 help
549 No restrictions apply. Both API and filesystem registration
550 is on. This is the normal default operation.
551
552config DEBUG_FS_DISALLOW_MOUNT
553 bool "Do not register debugfs as filesystem"
554 help
555 The API is open but filesystem is not loaded. Clients can still do
556 their work and read with debug tools that do not need
557 debugfs filesystem.
558
559config DEBUG_FS_ALLOW_NONE
560 bool "No access"
561 help
562 Access is off. Clients get -PERM when trying to create nodes in
563 debugfs tree and debugfs is not registered as a filesystem.
564 Client can then back-off or continue without debugfs access.
565
566endchoice
567
6210b640 568source "lib/Kconfig.kgdb"
6210b640 569source "lib/Kconfig.ubsan"
2645d432 570source "lib/Kconfig.kcsan"
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571
572endmenu
573
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574config DEBUG_KERNEL
575 bool "Kernel debugging"
fef2c9bc 576 help
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577 Say Y here if you are developing drivers or trying to debug and
578 identify kernel problems.
fef2c9bc 579
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580config DEBUG_MISC
581 bool "Miscellaneous debug code"
582 default DEBUG_KERNEL
583 depends on DEBUG_KERNEL
584 help
585 Say Y here if you need to enable miscellaneous debug code that should
586 be under a more specific debug option but isn't.
587
588
0610c8a8 589menu "Memory Debugging"
fef2c9bc 590
8636a1f9 591source "mm/Kconfig.debug"
fef2c9bc 592
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593config DEBUG_OBJECTS
594 bool "Debug object operations"
595 depends on DEBUG_KERNEL
9c44bc03 596 help
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597 If you say Y here, additional code will be inserted into the
598 kernel to track the life time of various objects and validate
599 the operations on those objects.
9c44bc03 600
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601config DEBUG_OBJECTS_SELFTEST
602 bool "Debug objects selftest"
603 depends on DEBUG_OBJECTS
604 help
605 This enables the selftest of the object debug code.
9c44bc03 606
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607config DEBUG_OBJECTS_FREE
608 bool "Debug objects in freed memory"
609 depends on DEBUG_OBJECTS
610 help
611 This enables checks whether a k/v free operation frees an area
612 which contains an object which has not been deactivated
613 properly. This can make kmalloc/kfree-intensive workloads
614 much slower.
3ac7fe5a 615
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TG
616config DEBUG_OBJECTS_TIMERS
617 bool "Debug timer objects"
618 depends on DEBUG_OBJECTS
619 help
620 If you say Y here, additional code will be inserted into the
621 timer routines to track the life time of timer objects and
622 validate the timer operations.
623
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TG
624config DEBUG_OBJECTS_WORK
625 bool "Debug work objects"
626 depends on DEBUG_OBJECTS
627 help
628 If you say Y here, additional code will be inserted into the
629 work queue routines to track the life time of work objects and
630 validate the work operations.
631
551d55a9
MD
632config DEBUG_OBJECTS_RCU_HEAD
633 bool "Debug RCU callbacks objects"
fc2ecf7e 634 depends on DEBUG_OBJECTS
551d55a9
MD
635 help
636 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
637
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TH
638config DEBUG_OBJECTS_PERCPU_COUNTER
639 bool "Debug percpu counter objects"
640 depends on DEBUG_OBJECTS
641 help
642 If you say Y here, additional code will be inserted into the
643 percpu counter routines to track the life time of percpu counter
644 objects and validate the percpu counter operations.
645
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IM
646config DEBUG_OBJECTS_ENABLE_DEFAULT
647 int "debug_objects bootup default value (0-1)"
68d4b3df
KK
648 range 0 1
649 default "1"
650 depends on DEBUG_OBJECTS
651 help
652 Debug objects boot parameter default value
3ae70205 653
1da177e4 654config DEBUG_SLAB
4a2f0acf 655 bool "Debug slab memory allocations"
4675ff05 656 depends on DEBUG_KERNEL && SLAB
1da177e4
LT
657 help
658 Say Y here to have the kernel do limited verification on memory
659 allocation as well as poisoning memory on free to catch use of freed
660 memory. This can make kmalloc/kfree-intensive workloads much slower.
661
f0630fff
CL
662config SLUB_DEBUG_ON
663 bool "SLUB debugging on by default"
4675ff05 664 depends on SLUB && SLUB_DEBUG
f0630fff
CL
665 default n
666 help
667 Boot with debugging on by default. SLUB boots by default with
668 the runtime debug capabilities switched off. Enabling this is
669 equivalent to specifying the "slub_debug" parameter on boot.
670 There is no support for more fine grained debug control like
671 possible with slub_debug=xxx. SLUB debugging may be switched
672 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
673 "slub_debug=-".
674
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CL
675config SLUB_STATS
676 default n
677 bool "Enable SLUB performance statistics"
ab4d5ed5 678 depends on SLUB && SYSFS
8ff12cfc
CL
679 help
680 SLUB statistics are useful to debug SLUBs allocation behavior in
681 order find ways to optimize the allocator. This should never be
682 enabled for production use since keeping statistics slows down
683 the allocator by a few percentage points. The slabinfo command
684 supports the determination of the most active slabs to figure
685 out which slabs are relevant to a particular load.
686 Try running: slabinfo -DA
687
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CM
688config HAVE_DEBUG_KMEMLEAK
689 bool
690
3bba00d7
CM
691config DEBUG_KMEMLEAK
692 bool "Kernel memory leak detector"
525c1f92 693 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 694 select DEBUG_FS
3bba00d7
CM
695 select STACKTRACE if STACKTRACE_SUPPORT
696 select KALLSYMS
b60e26a2 697 select CRC32
3bba00d7
CM
698 help
699 Say Y here if you want to enable the memory leak
700 detector. The memory allocation/freeing is traced in a way
701 similar to the Boehm's conservative garbage collector, the
702 difference being that the orphan objects are not freed but
703 only shown in /sys/kernel/debug/kmemleak. Enabling this
704 feature will introduce an overhead to memory
700199b0 705 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
706 details.
707
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DH
708 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
709 of finding leaks due to the slab objects poisoning.
710
711 In order to access the kmemleak file, debugfs needs to be
712 mounted (usually at /sys/kernel/debug).
713
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CM
714config DEBUG_KMEMLEAK_MEM_POOL_SIZE
715 int "Kmemleak memory pool size"
0610c8a8 716 depends on DEBUG_KMEMLEAK
c59180ae 717 range 200 1000000
b751c52b 718 default 16000
0610c8a8
DH
719 help
720 Kmemleak must track all the memory allocations to avoid
721 reporting false positives. Since memory may be allocated or
c5665868
CM
722 freed before kmemleak is fully initialised, use a static pool
723 of metadata objects to track such callbacks. After kmemleak is
724 fully initialised, this memory pool acts as an emergency one
725 if slab allocations fail.
0610c8a8
DH
726
727config DEBUG_KMEMLEAK_TEST
728 tristate "Simple test for the kernel memory leak detector"
729 depends on DEBUG_KMEMLEAK && m
730 help
731 This option enables a module that explicitly leaks memory.
732
733 If unsure, say N.
734
735config DEBUG_KMEMLEAK_DEFAULT_OFF
736 bool "Default kmemleak to off"
737 depends on DEBUG_KMEMLEAK
738 help
739 Say Y here to disable kmemleak by default. It can then be enabled
740 on the command line via kmemleak=on.
741
d53ce042
SK
742config DEBUG_KMEMLEAK_AUTO_SCAN
743 bool "Enable kmemleak auto scan thread on boot up"
744 default y
745 depends on DEBUG_KMEMLEAK
746 help
747 Depending on the cpu, kmemleak scan may be cpu intensive and can
748 stall user tasks at times. This option enables/disables automatic
749 kmemleak scan at boot up.
750
751 Say N here to disable kmemleak auto scan thread to stop automatic
752 scanning. Disabling this option disables automatic reporting of
753 memory leaks.
754
755 If unsure, say Y.
756
0610c8a8
DH
757config DEBUG_STACK_USAGE
758 bool "Stack utilization instrumentation"
6c31da34 759 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
760 help
761 Enables the display of the minimum amount of free stack which each
762 task has ever had available in the sysrq-T and sysrq-P debug output.
763
764 This option will slow down process creation somewhat.
765
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766config SCHED_STACK_END_CHECK
767 bool "Detect stack corruption on calls to schedule()"
768 depends on DEBUG_KERNEL
769 default n
770 help
771 This option checks for a stack overrun on calls to schedule().
772 If the stack end location is found to be over written always panic as
773 the content of the corrupted region can no longer be trusted.
774 This is to ensure no erroneous behaviour occurs which could result in
775 data corruption or a sporadic crash at a later stage once the region
776 is examined. The runtime overhead introduced is minimal.
777
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778config ARCH_HAS_DEBUG_VM_PGTABLE
779 bool
780 help
781 An architecture should select this when it can successfully
782 build and run DEBUG_VM_PGTABLE.
783
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DH
784config DEBUG_VM
785 bool "Debug VM"
786 depends on DEBUG_KERNEL
787 help
788 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 789 that may impact performance.
0610c8a8
DH
790
791 If unsure, say N.
792
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DB
793config DEBUG_VM_VMACACHE
794 bool "Debug VMA caching"
795 depends on DEBUG_VM
796 help
797 Enable this to turn on VMA caching debug information. Doing so
798 can cause significant overhead, so only enable it in non-production
799 environments.
800
801 If unsure, say N.
802
0610c8a8
DH
803config DEBUG_VM_RB
804 bool "Debug VM red-black trees"
805 depends on DEBUG_VM
806 help
a663dad6 807 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
808
809 If unsure, say N.
810
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KS
811config DEBUG_VM_PGFLAGS
812 bool "Debug page-flags operations"
813 depends on DEBUG_VM
814 help
815 Enables extra validation on page flags operations.
816
817 If unsure, say N.
818
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819config DEBUG_VM_PGTABLE
820 bool "Debug arch page table for semantics compliance"
821 depends on MMU
822 depends on ARCH_HAS_DEBUG_VM_PGTABLE
823 default y if DEBUG_VM
824 help
825 This option provides a debug method which can be used to test
826 architecture page table helper functions on various platforms in
827 verifying if they comply with expected generic MM semantics. This
828 will help architecture code in making sure that any changes or
829 new additions of these helpers still conform to expected
830 semantics of the generic MM. Platforms will have to opt in for
831 this through ARCH_HAS_DEBUG_VM_PGTABLE.
832
833 If unsure, say N.
834
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LA
835config ARCH_HAS_DEBUG_VIRTUAL
836 bool
837
0610c8a8
DH
838config DEBUG_VIRTUAL
839 bool "Debug VM translations"
fa5b6ec9 840 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
841 help
842 Enable some costly sanity checks in virtual to page code. This can
843 catch mistakes with virt_to_page() and friends.
844
845 If unsure, say N.
846
847config DEBUG_NOMMU_REGIONS
848 bool "Debug the global anon/private NOMMU mapping region tree"
849 depends on DEBUG_KERNEL && !MMU
850 help
851 This option causes the global tree of anonymous and private mapping
852 regions to be regularly checked for invalid topology.
853
854config DEBUG_MEMORY_INIT
855 bool "Debug memory initialisation" if EXPERT
856 default !EXPERT
857 help
858 Enable this for additional checks during memory initialisation.
859 The sanity checks verify aspects of the VM such as the memory model
860 and other information provided by the architecture. Verbose
861 information will be printed at KERN_DEBUG loglevel depending
862 on the mminit_loglevel= command-line option.
863
864 If unsure, say Y
865
866config MEMORY_NOTIFIER_ERROR_INJECT
867 tristate "Memory hotplug notifier error injection module"
868 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
869 help
870 This option provides the ability to inject artificial errors to
871 memory hotplug notifier chain callbacks. It is controlled through
872 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
873
874 If the notifier call chain should be failed with some events
875 notified, write the error code to "actions/<notifier event>/error".
876
877 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
878
879 # cd /sys/kernel/debug/notifier-error-inject/memory
880 # echo -12 > actions/MEM_GOING_OFFLINE/error
881 # echo offline > /sys/devices/system/memory/memoryXXX/state
882 bash: echo: write error: Cannot allocate memory
883
884 To compile this code as a module, choose M here: the module will
885 be called memory-notifier-error-inject.
886
887 If unsure, say N.
888
889config DEBUG_PER_CPU_MAPS
890 bool "Debug access to per_cpu maps"
891 depends on DEBUG_KERNEL
892 depends on SMP
893 help
894 Say Y to verify that the per_cpu map being accessed has
895 been set up. This adds a fair amount of code to kernel memory
896 and decreases performance.
897
898 Say N if unsure.
899
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TG
900config DEBUG_KMAP_LOCAL
901 bool "Debug kmap_local temporary mappings"
902 depends on DEBUG_KERNEL && KMAP_LOCAL
903 help
904 This option enables additional error checking for the kmap_local
905 infrastructure. Disable for production use.
906
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TG
907config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
908 bool
909
910config DEBUG_KMAP_LOCAL_FORCE_MAP
911 bool "Enforce kmap_local temporary mappings"
912 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
913 select KMAP_LOCAL
914 select DEBUG_KMAP_LOCAL
915 help
916 This option enforces temporary mappings through the kmap_local
917 mechanism for non-highmem pages and on non-highmem systems.
918 Disable this for production systems!
919
0610c8a8
DH
920config DEBUG_HIGHMEM
921 bool "Highmem debugging"
922 depends on DEBUG_KERNEL && HIGHMEM
0e91a0c6 923 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
6e799cb6 924 select DEBUG_KMAP_LOCAL
0610c8a8 925 help
b1357c9f
GU
926 This option enables additional error checking for high memory
927 systems. Disable for production systems.
0610c8a8
DH
928
929config HAVE_DEBUG_STACKOVERFLOW
930 bool
931
932config DEBUG_STACKOVERFLOW
933 bool "Check for stack overflows"
934 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 935 help
0610c8a8 936 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 937 and exception stacks (if your architecture uses them). This
0610c8a8
DH
938 option will show detailed messages if free stack space drops
939 below a certain limit.
940
941 These kinds of bugs usually occur when call-chains in the
942 kernel get too deep, especially when interrupts are
943 involved.
944
945 Use this in cases where you see apparently random memory
946 corruption, especially if it appears in 'struct thread_info'
947
948 If in doubt, say "N".
949
0b24becc 950source "lib/Kconfig.kasan"
0ce20dd8 951source "lib/Kconfig.kfence"
0b24becc 952
0610c8a8
DH
953endmenu # "Memory Debugging"
954
a304e1b8
DW
955config DEBUG_SHIRQ
956 bool "Debug shared IRQ handlers"
0244ad00 957 depends on DEBUG_KERNEL
a304e1b8 958 help
0a2fae2a
WS
959 Enable this to generate a spurious interrupt just before a shared
960 interrupt handler is deregistered (generating one when registering
961 is currently disabled). Drivers need to handle this correctly. Some
962 don't and need to be caught.
a304e1b8 963
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CD
964menu "Debug Oops, Lockups and Hangs"
965
966config PANIC_ON_OOPS
967 bool "Panic on Oops"
968 help
969 Say Y here to enable the kernel to panic when it oopses. This
970 has the same effect as setting oops=panic on the kernel command
971 line.
972
973 This feature is useful to ensure that the kernel does not do
974 anything erroneous after an oops which could result in data
975 corruption or other issues.
976
977 Say N if unsure.
978
979config PANIC_ON_OOPS_VALUE
980 int
981 range 0 1
982 default 0 if !PANIC_ON_OOPS
983 default 1 if PANIC_ON_OOPS
984
985config PANIC_TIMEOUT
986 int "panic timeout"
987 default 0
988 help
9d5b134f 989 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
990 the kernel panics. If n = 0, then we wait forever. A timeout
991 value n > 0 will wait n seconds before rebooting, while a timeout
992 value n < 0 will reboot immediately.
92aef8fb 993
58687acb 994config LOCKUP_DETECTOR
05a4a952
NP
995 bool
996
997config SOFTLOCKUP_DETECTOR
998 bool "Detect Soft Lockups"
dea20a3f 999 depends on DEBUG_KERNEL && !S390
05a4a952 1000 select LOCKUP_DETECTOR
8446f1d3 1001 help
58687acb 1002 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 1003 soft lockups.
58687acb
DZ
1004
1005 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 1006 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
1007 chance to run. The current stack trace is displayed upon
1008 detection and the system will stay locked up.
8446f1d3 1009
5f00ae0d
RD
1010config BOOTPARAM_SOFTLOCKUP_PANIC
1011 bool "Panic (Reboot) On Soft Lockups"
1012 depends on SOFTLOCKUP_DETECTOR
1013 help
1014 Say Y here to enable the kernel to panic on "soft lockups",
1015 which are bugs that cause the kernel to loop in kernel
1016 mode for more than 20 seconds (configurable using the watchdog_thresh
1017 sysctl), without giving other tasks a chance to run.
1018
1019 The panic can be used in combination with panic_timeout,
1020 to cause the system to reboot automatically after a
1021 lockup has been detected. This feature is useful for
1022 high-availability systems that have uptime guarantees and
1023 where a lockup must be resolved ASAP.
1024
1025 Say N if unsure.
1026
1027config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
1028 int
1029 depends on SOFTLOCKUP_DETECTOR
1030 range 0 1
1031 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
1032 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
1033
05a4a952
NP
1034config HARDLOCKUP_DETECTOR_PERF
1035 bool
1036 select SOFTLOCKUP_DETECTOR
1037
7edaeb68
TG
1038#
1039# Enables a timestamp based low pass filter to compensate for perf based
1040# hard lockup detection which runs too fast due to turbo modes.
1041#
1042config HARDLOCKUP_CHECK_TIMESTAMP
1043 bool
1044
05a4a952
NP
1045#
1046# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1047# lockup detector rather than the perf based detector.
1048#
1049config HARDLOCKUP_DETECTOR
1050 bool "Detect Hard Lockups"
1051 depends on DEBUG_KERNEL && !S390
1052 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1053 select LOCKUP_DETECTOR
1054 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1055 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1056 help
1057 Say Y here to enable the kernel to act as a watchdog to detect
1058 hard lockups.
1059
58687acb 1060 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 1061 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
1062 chance to run. The current stack trace is displayed upon detection
1063 and the system will stay locked up.
8446f1d3 1064
fef2c9bc
DZ
1065config BOOTPARAM_HARDLOCKUP_PANIC
1066 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 1067 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1068 help
1069 Say Y here to enable the kernel to panic on "hard lockups",
1070 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1071 mode with interrupts disabled for more than 10 seconds (configurable
1072 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1073
1074 Say N if unsure.
1075
1076config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1077 int
8f1f66ed 1078 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1079 range 0 1
1080 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1081 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1082
e162b39a
MSB
1083config DETECT_HUNG_TASK
1084 bool "Detect Hung Tasks"
1085 depends on DEBUG_KERNEL
05a4a952 1086 default SOFTLOCKUP_DETECTOR
e162b39a 1087 help
0610c8a8
DH
1088 Say Y here to enable the kernel to detect "hung tasks",
1089 which are bugs that cause the task to be stuck in
96b03ab8 1090 uninterruptible "D" state indefinitely.
1da177e4 1091
0610c8a8
DH
1092 When a hung task is detected, the kernel will print the
1093 current stack trace (which you should report), but the
1094 task will stay in uninterruptible state. If lockdep is
1095 enabled then all held locks will also be reported. This
1096 feature has negligible overhead.
871751e2 1097
0610c8a8
DH
1098config DEFAULT_HUNG_TASK_TIMEOUT
1099 int "Default timeout for hung task detection (in seconds)"
1100 depends on DETECT_HUNG_TASK
1101 default 120
f0630fff 1102 help
0610c8a8
DH
1103 This option controls the default timeout (in seconds) used
1104 to determine when a task has become non-responsive and should
1105 be considered hung.
f0630fff 1106
0610c8a8
DH
1107 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1108 sysctl or by writing a value to
1109 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1110
0610c8a8
DH
1111 A timeout of 0 disables the check. The default is two minutes.
1112 Keeping the default should be fine in most cases.
b69ec42b 1113
0610c8a8
DH
1114config BOOTPARAM_HUNG_TASK_PANIC
1115 bool "Panic (Reboot) On Hung Tasks"
1116 depends on DETECT_HUNG_TASK
3bba00d7 1117 help
0610c8a8
DH
1118 Say Y here to enable the kernel to panic on "hung tasks",
1119 which are bugs that cause the kernel to leave a task stuck
1120 in uninterruptible "D" state.
3bba00d7 1121
0610c8a8
DH
1122 The panic can be used in combination with panic_timeout,
1123 to cause the system to reboot automatically after a
1124 hung task has been detected. This feature is useful for
1125 high-availability systems that have uptime guarantees and
1126 where a hung tasks must be resolved ASAP.
bf96d1e3 1127
0610c8a8 1128 Say N if unsure.
bf96d1e3 1129
0610c8a8
DH
1130config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1131 int
1132 depends on DETECT_HUNG_TASK
1133 range 0 1
1134 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1135 default 1 if BOOTPARAM_HUNG_TASK_PANIC
3bba00d7 1136
82607adc
TH
1137config WQ_WATCHDOG
1138 bool "Detect Workqueue Stalls"
1139 depends on DEBUG_KERNEL
1140 help
1141 Say Y here to enable stall detection on workqueues. If a
1142 worker pool doesn't make forward progress on a pending work
1143 item for over a given amount of time, 30s by default, a
1144 warning message is printed along with dump of workqueue
1145 state. This can be configured through kernel parameter
1146 "workqueue.watchdog_thresh" and its sysfs counterpart.
1147
30428ef5
KK
1148config TEST_LOCKUP
1149 tristate "Test module to generate lockups"
63646bc9 1150 depends on m
30428ef5
KK
1151 help
1152 This builds the "test_lockup" module that helps to make sure
1153 that watchdogs and lockup detectors are working properly.
1154
1155 Depending on module parameters it could emulate soft or hard
1156 lockup, "hung task", or locking arbitrary lock for a long time.
1157 Also it could generate series of lockups with cooling-down periods.
1158
1159 If unsure, say N.
1160
92aef8fb
DH
1161endmenu # "Debug lockups and hangs"
1162
ebebdd09 1163menu "Scheduler Debugging"
5800dc3c 1164
0610c8a8
DH
1165config SCHED_DEBUG
1166 bool "Collect scheduler debugging info"
1167 depends on DEBUG_KERNEL && PROC_FS
1168 default y
0822ee4a 1169 help
0610c8a8
DH
1170 If you say Y here, the /proc/sched_debug file will be provided
1171 that can help debug the scheduler. The runtime overhead of this
1172 option is minimal.
0822ee4a 1173
f6db8347
NR
1174config SCHED_INFO
1175 bool
1176 default n
1177
0610c8a8
DH
1178config SCHEDSTATS
1179 bool "Collect scheduler statistics"
1180 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1181 select SCHED_INFO
0610c8a8
DH
1182 help
1183 If you say Y here, additional code will be inserted into the
1184 scheduler and related routines to collect statistics about
1185 scheduler behavior and provide them in /proc/schedstat. These
1186 stats may be useful for both tuning and debugging the scheduler
1187 If you aren't debugging the scheduler or trying to tune a specific
1188 application, you can say N to avoid the very slight overhead
1189 this adds.
0822ee4a 1190
ebebdd09 1191endmenu
0d9e2632 1192
3c17ad19
JS
1193config DEBUG_TIMEKEEPING
1194 bool "Enable extra timekeeping sanity checking"
1195 help
1196 This option will enable additional timekeeping sanity checks
1197 which may be helpful when diagnosing issues where timekeeping
1198 problems are suspected.
1199
1200 This may include checks in the timekeeping hotpaths, so this
1201 option may have a (very small) performance impact to some
1202 workloads.
1203
1204 If unsure, say N.
1205
1da177e4
LT
1206config DEBUG_PREEMPT
1207 bool "Debug preemptible kernel"
9f472869 1208 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1209 default y
1210 help
1211 If you say Y here then the kernel will use a debug variant of the
1212 commonly used smp_processor_id() function and will print warnings
1213 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1214 will detect preemption count underflows.
1215
9eade16b
DH
1216menu "Lock Debugging (spinlocks, mutexes, etc...)"
1217
f07cbebb
WL
1218config LOCK_DEBUGGING_SUPPORT
1219 bool
1220 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1221 default y
1222
19193bca
WL
1223config PROVE_LOCKING
1224 bool "Lock debugging: prove locking correctness"
1225 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1226 select LOCKDEP
1227 select DEBUG_SPINLOCK
1228 select DEBUG_MUTEXES
1229 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1230 select DEBUG_RWSEMS
19193bca
WL
1231 select DEBUG_WW_MUTEX_SLOWPATH
1232 select DEBUG_LOCK_ALLOC
8fd8ad5c 1233 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1234 select TRACE_IRQFLAGS
1235 default n
1236 help
1237 This feature enables the kernel to prove that all locking
1238 that occurs in the kernel runtime is mathematically
1239 correct: that under no circumstance could an arbitrary (and
1240 not yet triggered) combination of observed locking
1241 sequences (on an arbitrary number of CPUs, running an
1242 arbitrary number of tasks and interrupt contexts) cause a
1243 deadlock.
1244
1245 In short, this feature enables the kernel to report locking
1246 related deadlocks before they actually occur.
1247
1248 The proof does not depend on how hard and complex a
1249 deadlock scenario would be to trigger: how many
1250 participant CPUs, tasks and irq-contexts would be needed
1251 for it to trigger. The proof also does not depend on
1252 timing: if a race and a resulting deadlock is possible
1253 theoretically (no matter how unlikely the race scenario
1254 is), it will be proven so and will immediately be
1255 reported by the kernel (once the event is observed that
1256 makes the deadlock theoretically possible).
1257
1258 If a deadlock is impossible (i.e. the locking rules, as
1259 observed by the kernel, are mathematically correct), the
1260 kernel reports nothing.
1261
1262 NOTE: this feature can also be enabled for rwlocks, mutexes
1263 and rwsems - in which case all dependencies between these
1264 different locking variants are observed and mapped too, and
1265 the proof of observed correctness is also maintained for an
1266 arbitrary combination of these separate locking variants.
1267
387b1468 1268 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1269
de8f5e4f
PZ
1270config PROVE_RAW_LOCK_NESTING
1271 bool "Enable raw_spinlock - spinlock nesting checks"
1272 depends on PROVE_LOCKING
1273 default n
1274 help
1275 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1276 that the lock nesting rules for PREEMPT_RT enabled kernels are
1277 not violated.
1278
1279 NOTE: There are known nesting problems. So if you enable this
1280 option expect lockdep splats until these problems have been fully
1281 addressed which is work in progress. This config switch allows to
1282 identify and analyze these problems. It will be removed and the
1283 check permanentely enabled once the main issues have been fixed.
1284
1285 If unsure, select N.
1286
19193bca
WL
1287config LOCK_STAT
1288 bool "Lock usage statistics"
1289 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1290 select LOCKDEP
1291 select DEBUG_SPINLOCK
1292 select DEBUG_MUTEXES
1293 select DEBUG_RT_MUTEXES if RT_MUTEXES
1294 select DEBUG_LOCK_ALLOC
1295 default n
1296 help
1297 This feature enables tracking lock contention points
1298
387b1468 1299 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1300
1301 This also enables lock events required by "perf lock",
1302 subcommand of perf.
1303 If you want to use "perf lock", you also need to turn on
1304 CONFIG_EVENT_TRACING.
1305
1306 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1307 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1308
e7eebaf6
IM
1309config DEBUG_RT_MUTEXES
1310 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1311 depends on DEBUG_KERNEL && RT_MUTEXES
1312 help
1313 This allows rt mutex semantics violations and rt mutex related
1314 deadlocks (lockups) to be detected and reported automatically.
1315
1da177e4 1316config DEBUG_SPINLOCK
4d9f34ad 1317 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1318 depends on DEBUG_KERNEL
e335e3eb 1319 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1320 help
1321 Say Y here and build SMP to catch missing spinlock initialization
1322 and certain other kinds of spinlock errors commonly made. This is
1323 best used in conjunction with the NMI watchdog so that spinlock
1324 deadlocks are also debuggable.
1325
4d9f34ad
IM
1326config DEBUG_MUTEXES
1327 bool "Mutex debugging: basic checks"
1328 depends on DEBUG_KERNEL
1329 help
1330 This feature allows mutex semantics violations to be detected and
1331 reported.
1332
23010027
DV
1333config DEBUG_WW_MUTEX_SLOWPATH
1334 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1335 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1336 select DEBUG_LOCK_ALLOC
1337 select DEBUG_SPINLOCK
1338 select DEBUG_MUTEXES
1339 help
1340 This feature enables slowpath testing for w/w mutex users by
1341 injecting additional -EDEADLK wound/backoff cases. Together with
1342 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1343 will test all possible w/w mutex interface abuse with the
1344 exception of simply not acquiring all the required locks.
4d692373
RC
1345 Note that this feature can introduce significant overhead, so
1346 it really should not be enabled in a production or distro kernel,
1347 even a debug kernel. If you are a driver writer, enable it. If
1348 you are a distro, do not.
23010027 1349
5149cbac
WL
1350config DEBUG_RWSEMS
1351 bool "RW Semaphore debugging: basic checks"
c71fd893 1352 depends on DEBUG_KERNEL
5149cbac 1353 help
c71fd893
WL
1354 This debugging feature allows mismatched rw semaphore locks
1355 and unlocks to be detected and reported.
5149cbac 1356
4d9f34ad
IM
1357config DEBUG_LOCK_ALLOC
1358 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1359 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad
IM
1360 select DEBUG_SPINLOCK
1361 select DEBUG_MUTEXES
f5694788 1362 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1363 select LOCKDEP
1364 help
1365 This feature will check whether any held lock (spinlock, rwlock,
1366 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1367 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1368 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1369 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1370 held during task exit.
1371
4d9f34ad
IM
1372config LOCKDEP
1373 bool
f07cbebb 1374 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1375 select STACKTRACE
f9b58e8c 1376 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
4d9f34ad
IM
1377 select KALLSYMS
1378 select KALLSYMS_ALL
1379
395102db
DJ
1380config LOCKDEP_SMALL
1381 bool
1382
4d9f34ad
IM
1383config DEBUG_LOCKDEP
1384 bool "Lock dependency engine debugging"
517e7aa5 1385 depends on DEBUG_KERNEL && LOCKDEP
997acaf6 1386 select DEBUG_IRQFLAGS
4d9f34ad
IM
1387 help
1388 If you say Y here, the lock dependency engine will do
1389 additional runtime checks to debug itself, at the price
1390 of more runtime overhead.
1391
d902db1e
FW
1392config DEBUG_ATOMIC_SLEEP
1393 bool "Sleep inside atomic section checking"
e8f7c70f 1394 select PREEMPT_COUNT
1da177e4 1395 depends on DEBUG_KERNEL
87a4c375 1396 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1397 help
1398 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1399 noisy if they are called inside atomic sections: when a spinlock is
1400 held, inside an rcu read side critical section, inside preempt disabled
1401 sections, inside an interrupt, etc...
1da177e4 1402
cae2ed9a
IM
1403config DEBUG_LOCKING_API_SELFTESTS
1404 bool "Locking API boot-time self-tests"
1405 depends on DEBUG_KERNEL
1406 help
1407 Say Y here if you want the kernel to run a short self-test during
1408 bootup. The self-test checks whether common types of locking bugs
1409 are detected by debugging mechanisms or not. (if you disable
1410 lock debugging then those bugs wont be detected of course.)
1411 The following locking APIs are covered: spinlocks, rwlocks,
1412 mutexes and rwsems.
1413
0af3fe1e
PM
1414config LOCK_TORTURE_TEST
1415 tristate "torture tests for locking"
1416 depends on DEBUG_KERNEL
1417 select TORTURE_TEST
0af3fe1e
PM
1418 help
1419 This option provides a kernel module that runs torture tests
1420 on kernel locking primitives. The kernel module may be built
1421 after the fact on the running kernel to be tested, if desired.
1422
1423 Say Y here if you want kernel locking-primitive torture tests
1424 to be built into the kernel.
1425 Say M if you want these torture tests to build as a module.
1426 Say N if you are unsure.
1427
f2a5fec1
CW
1428config WW_MUTEX_SELFTEST
1429 tristate "Wait/wound mutex selftests"
1430 help
1431 This option provides a kernel module that runs tests on the
1432 on the struct ww_mutex locking API.
1433
1434 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1435 with this test harness.
1436
1437 Say M if you want these self tests to build as a module.
1438 Say N if you are unsure.
1439
e9d338a0
PM
1440config SCF_TORTURE_TEST
1441 tristate "torture tests for smp_call_function*()"
1442 depends on DEBUG_KERNEL
1443 select TORTURE_TEST
1444 help
1445 This option provides a kernel module that runs torture tests
1446 on the smp_call_function() family of primitives. The kernel
1447 module may be built after the fact on the running kernel to
1448 be tested, if desired.
1449
35feb604
PM
1450config CSD_LOCK_WAIT_DEBUG
1451 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1452 depends on DEBUG_KERNEL
1453 depends on 64BIT
1454 default n
1455 help
1456 This option enables debug prints when CPUs are slow to respond
1457 to the smp_call_function*() IPI wrappers. These debug prints
1458 include the IPI handler function currently executing (if any)
1459 and relevant stack traces.
1460
9eade16b 1461endmenu # lock debugging
8637c099 1462
9eade16b 1463config TRACE_IRQFLAGS
ed004953 1464 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1465 bool
5ca43f6c 1466 help
9eade16b
DH
1467 Enables hooks to interrupt enabling and disabling for
1468 either tracing or lock debugging.
5ca43f6c 1469
ed004953 1470config TRACE_IRQFLAGS_NMI
1471 def_bool y
1472 depends on TRACE_IRQFLAGS
1473 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1474
997acaf6
MR
1475config DEBUG_IRQFLAGS
1476 bool "Debug IRQ flag manipulation"
1477 help
1478 Enables checks for potentially unsafe enabling or disabling of
1479 interrupts, such as calling raw_local_irq_restore() when interrupts
1480 are enabled.
1481
8637c099 1482config STACKTRACE
0c38e1fe 1483 bool "Stack backtrace support"
8637c099 1484 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1485 help
1486 This option causes the kernel to create a /proc/pid/stack for
1487 every process, showing its current stack trace.
1488 It is also used by various kernel debugging features that require
1489 stack trace generation.
5ca43f6c 1490
eecabf56
TT
1491config WARN_ALL_UNSEEDED_RANDOM
1492 bool "Warn for all uses of unseeded randomness"
1493 default n
d06bfd19
JD
1494 help
1495 Some parts of the kernel contain bugs relating to their use of
1496 cryptographically secure random numbers before it's actually possible
1497 to generate those numbers securely. This setting ensures that these
1498 flaws don't go unnoticed, by enabling a message, should this ever
1499 occur. This will allow people with obscure setups to know when things
1500 are going wrong, so that they might contact developers about fixing
1501 it.
1502
eecabf56
TT
1503 Unfortunately, on some models of some architectures getting
1504 a fully seeded CRNG is extremely difficult, and so this can
1505 result in dmesg getting spammed for a surprisingly long
1506 time. This is really bad from a security perspective, and
1507 so architecture maintainers really need to do what they can
1508 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1509 However, since users cannot do anything actionable to
eecabf56
TT
1510 address this, by default the kernel will issue only a single
1511 warning for the first use of unseeded randomness.
1512
1513 Say Y here if you want to receive warnings for all uses of
1514 unseeded randomness. This will be of use primarily for
4c5d114e 1515 those developers interested in improving the security of
eecabf56
TT
1516 Linux kernels running on their architecture (or
1517 subarchitecture).
d06bfd19 1518
1da177e4
LT
1519config DEBUG_KOBJECT
1520 bool "kobject debugging"
1521 depends on DEBUG_KERNEL
1522 help
1523 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1524 to the syslog.
1da177e4 1525
c817a67e
RK
1526config DEBUG_KOBJECT_RELEASE
1527 bool "kobject release debugging"
2a999aa0 1528 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1529 help
1530 kobjects are reference counted objects. This means that their
1531 last reference count put is not predictable, and the kobject can
1532 live on past the point at which a driver decides to drop it's
1533 initial reference to the kobject gained on allocation. An
1534 example of this would be a struct device which has just been
1535 unregistered.
1536
1537 However, some buggy drivers assume that after such an operation,
1538 the memory backing the kobject can be immediately freed. This
1539 goes completely against the principles of a refcounted object.
1540
1541 If you say Y here, the kernel will delay the release of kobjects
1542 on the last reference count to improve the visibility of this
1543 kind of kobject release bug.
1544
9b2a60c4
CM
1545config HAVE_DEBUG_BUGVERBOSE
1546 bool
1547
3be5cbcd 1548menu "Debug kernel data structures"
1da177e4 1549
199a9afc
DJ
1550config DEBUG_LIST
1551 bool "Debug linked list manipulation"
4520bcb2 1552 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1553 help
1554 Enable this to turn on extended checks in the linked-list
1555 walking routines.
1556
1557 If unsure, say N.
1558
8e18faea 1559config DEBUG_PLIST
b8cfff68
DS
1560 bool "Debug priority linked list manipulation"
1561 depends on DEBUG_KERNEL
1562 help
1563 Enable this to turn on extended checks in the priority-ordered
1564 linked-list (plist) walking routines. This checks the entire
1565 list multiple times during each manipulation.
1566
1567 If unsure, say N.
1568
d6ec0842
JA
1569config DEBUG_SG
1570 bool "Debug SG table operations"
1571 depends on DEBUG_KERNEL
1572 help
1573 Enable this to turn on checks on scatter-gather tables. This can
1574 help find problems with drivers that do not properly initialize
1575 their sg tables.
1576
1577 If unsure, say N.
1578
1b2439db
AV
1579config DEBUG_NOTIFIERS
1580 bool "Debug notifier call chains"
1581 depends on DEBUG_KERNEL
1582 help
1583 Enable this to turn on sanity checking for notifier call chains.
1584 This is most useful for kernel developers to make sure that
1585 modules properly unregister themselves from notifier chains.
1586 This is a relatively cheap check but if you care about maximum
1587 performance, say N.
1588
3be5cbcd
CD
1589config BUG_ON_DATA_CORRUPTION
1590 bool "Trigger a BUG when data corruption is detected"
1591 select DEBUG_LIST
1592 help
1593 Select this option if the kernel should BUG when it encounters
1594 data corruption in kernel memory structures when they get checked
1595 for validity.
1596
1597 If unsure, say N.
1598
1599endmenu
1600
e0e81739
DH
1601config DEBUG_CREDENTIALS
1602 bool "Debug credential management"
1603 depends on DEBUG_KERNEL
1604 help
1605 Enable this to turn on some debug checking for credential
1606 management. The additional code keeps track of the number of
1607 pointers from task_structs to any given cred struct, and checks to
1608 see that this number never exceeds the usage count of the cred
1609 struct.
1610
1611 Furthermore, if SELinux is enabled, this also checks that the
1612 security pointer in the cred struct is never seen to be invalid.
1613
1614 If unsure, say N.
1615
43a0a2a7 1616source "kernel/rcu/Kconfig.debug"
2f03e3ca 1617
f303fccb
TH
1618config DEBUG_WQ_FORCE_RR_CPU
1619 bool "Force round-robin CPU selection for unbound work items"
1620 depends on DEBUG_KERNEL
1621 default n
1622 help
1623 Workqueue used to implicitly guarantee that work items queued
1624 without explicit CPU specified are put on the local CPU. This
1625 guarantee is no longer true and while local CPU is still
1626 preferred work items may be put on foreign CPUs. Kernel
1627 parameter "workqueue.debug_force_rr_cpu" is added to force
1628 round-robin CPU selection to flush out usages which depend on the
1629 now broken guarantee. This config option enables the debug
1630 feature by default. When enabled, memory and cache locality will
1631 be impacted.
1632
870d6656 1633config DEBUG_BLOCK_EXT_DEVT
68d4b3df 1634 bool "Force extended block device numbers and spread them"
870d6656
TH
1635 depends on DEBUG_KERNEL
1636 depends on BLOCK
759f8ca3 1637 default n
870d6656 1638 help
0e11e342
TH
1639 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1640 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1641 YOU ARE DOING. Distros, please enable this and fix whatever
1642 is broken.
1643
870d6656
TH
1644 Conventionally, block device numbers are allocated from
1645 predetermined contiguous area. However, extended block area
1646 may introduce non-contiguous block device numbers. This
1647 option forces most block device numbers to be allocated from
1648 the extended space and spreads them to discover kernel or
1649 userland code paths which assume predetermined contiguous
1650 device number allocation.
1651
55dc7db7
TH
1652 Note that turning on this debug option shuffles all the
1653 device numbers for all IDE and SCSI devices including libata
1654 ones, so root partition specified using device number
1655 directly (via rdev or root=MAJ:MIN) won't work anymore.
1656 Textual device names (root=/dev/sdXn) will continue to work.
1657
870d6656
TH
1658 Say N if you are unsure.
1659
757c989b
TG
1660config CPU_HOTPLUG_STATE_CONTROL
1661 bool "Enable CPU hotplug state control"
1662 depends on DEBUG_KERNEL
1663 depends on HOTPLUG_CPU
1664 default n
1665 help
1666 Allows to write steps between "offline" and "online" to the CPUs
1667 sysfs target file so states can be stepped granular. This is a debug
1668 option for now as the hotplug machinery cannot be stopped and
1669 restarted at arbitrary points yet.
1670
1671 Say N if your are unsure.
1672
09a74952
CD
1673config LATENCYTOP
1674 bool "Latency measuring infrastructure"
1675 depends on DEBUG_KERNEL
1676 depends on STACKTRACE_SUPPORT
1677 depends on PROC_FS
1678 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1679 select KALLSYMS
1680 select KALLSYMS_ALL
1681 select STACKTRACE
1682 select SCHEDSTATS
1683 select SCHED_DEBUG
1684 help
1685 Enable this option if you want to use the LatencyTOP tool
1686 to find out which userspace is blocking on what kernel operations.
1687
1688source "kernel/trace/Kconfig"
1689
1690config PROVIDE_OHCI1394_DMA_INIT
1691 bool "Remote debugging over FireWire early on boot"
1692 depends on PCI && X86
1693 help
1694 If you want to debug problems which hang or crash the kernel early
1695 on boot and the crashing machine has a FireWire port, you can use
1696 this feature to remotely access the memory of the crashed machine
1697 over FireWire. This employs remote DMA as part of the OHCI1394
1698 specification which is now the standard for FireWire controllers.
1699
1700 With remote DMA, you can monitor the printk buffer remotely using
1701 firescope and access all memory below 4GB using fireproxy from gdb.
1702 Even controlling a kernel debugger is possible using remote DMA.
1703
1704 Usage:
1705
1706 If ohci1394_dma=early is used as boot parameter, it will initialize
1707 all OHCI1394 controllers which are found in the PCI config space.
1708
1709 As all changes to the FireWire bus such as enabling and disabling
1710 devices cause a bus reset and thereby disable remote DMA for all
1711 devices, be sure to have the cable plugged and FireWire enabled on
1712 the debugging host before booting the debug target for debugging.
1713
1714 This code (~1k) is freed after boot. By then, the firewire stack
1715 in charge of the OHCI-1394 controllers should be used instead.
1716
a74e2a22 1717 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1718
045f6d79
CD
1719source "samples/Kconfig"
1720
1721config ARCH_HAS_DEVMEM_IS_ALLOWED
1722 bool
1723
1724config STRICT_DEVMEM
1725 bool "Filter access to /dev/mem"
1726 depends on MMU && DEVMEM
527701ed 1727 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
045f6d79
CD
1728 default y if PPC || X86 || ARM64
1729 help
1730 If this option is disabled, you allow userspace (root) access to all
1731 of memory, including kernel and userspace memory. Accidental
1732 access to this is obviously disastrous, but specific access can
1733 be used by people debugging the kernel. Note that with PAT support
1734 enabled, even in this case there are restrictions on /dev/mem
1735 use due to the cache aliasing requirements.
1736
1737 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1738 file only allows userspace access to PCI space and the BIOS code and
1739 data regions. This is sufficient for dosemu and X and all common
1740 users of /dev/mem.
1741
1742 If in doubt, say Y.
1743
1744config IO_STRICT_DEVMEM
1745 bool "Filter I/O access to /dev/mem"
1746 depends on STRICT_DEVMEM
1747 help
1748 If this option is disabled, you allow userspace (root) access to all
1749 io-memory regardless of whether a driver is actively using that
1750 range. Accidental access to this is obviously disastrous, but
1751 specific access can be used by people debugging kernel drivers.
1752
1753 If this option is switched on, the /dev/mem file only allows
1754 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1755 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1756 if the driver using a given range cannot be disabled.
1757
1758 If in doubt, say Y.
1759
1760menu "$(SRCARCH) Debugging"
1761
1762source "arch/$(SRCARCH)/Kconfig.debug"
1763
1764endmenu
1765
1766menu "Kernel Testing and Coverage"
1767
09a74952
CD
1768source "lib/kunit/Kconfig"
1769
8d438288
AM
1770config NOTIFIER_ERROR_INJECTION
1771 tristate "Notifier error injection"
1772 depends on DEBUG_KERNEL
1773 select DEBUG_FS
1774 help
e41e85cc 1775 This option provides the ability to inject artificial errors to
8d438288
AM
1776 specified notifier chain callbacks. It is useful to test the error
1777 handling of notifier call chain failures.
1778
1779 Say N if unsure.
1780
048b9c35
AM
1781config PM_NOTIFIER_ERROR_INJECT
1782 tristate "PM notifier error injection module"
1783 depends on PM && NOTIFIER_ERROR_INJECTION
1784 default m if PM_DEBUG
1785 help
e41e85cc 1786 This option provides the ability to inject artificial errors to
048b9c35
AM
1787 PM notifier chain callbacks. It is controlled through debugfs
1788 interface /sys/kernel/debug/notifier-error-inject/pm
1789
1790 If the notifier call chain should be failed with some events
1791 notified, write the error code to "actions/<notifier event>/error".
1792
1793 Example: Inject PM suspend error (-12 = -ENOMEM)
1794
1795 # cd /sys/kernel/debug/notifier-error-inject/pm/
1796 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1797 # echo mem > /sys/power/state
1798 bash: echo: write error: Cannot allocate memory
1799
1800 To compile this code as a module, choose M here: the module will
1801 be called pm-notifier-error-inject.
1802
1803 If unsure, say N.
1804
d526e85f
BH
1805config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1806 tristate "OF reconfig notifier error injection module"
1807 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1808 help
e41e85cc 1809 This option provides the ability to inject artificial errors to
d526e85f 1810 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1811 through debugfs interface under
d526e85f 1812 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1813
1814 If the notifier call chain should be failed with some events
1815 notified, write the error code to "actions/<notifier event>/error".
1816
1817 To compile this code as a module, choose M here: the module will
e12a95f4 1818 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1819
1820 If unsure, say N.
1821
02fff96a
NA
1822config NETDEV_NOTIFIER_ERROR_INJECT
1823 tristate "Netdev notifier error injection module"
1824 depends on NET && NOTIFIER_ERROR_INJECTION
1825 help
1826 This option provides the ability to inject artificial errors to
1827 netdevice notifier chain callbacks. It is controlled through debugfs
1828 interface /sys/kernel/debug/notifier-error-inject/netdev
1829
1830 If the notifier call chain should be failed with some events
1831 notified, write the error code to "actions/<notifier event>/error".
1832
1833 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1834
1835 # cd /sys/kernel/debug/notifier-error-inject/netdev
1836 # echo -22 > actions/NETDEV_CHANGEMTU/error
1837 # ip link set eth0 mtu 1024
1838 RTNETLINK answers: Invalid argument
1839
1840 To compile this code as a module, choose M here: the module will
1841 be called netdev-notifier-error-inject.
1842
1843 If unsure, say N.
1844
f1b4bd06
MP
1845config FUNCTION_ERROR_INJECTION
1846 def_bool y
1847 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1848
6ff1cb35 1849config FAULT_INJECTION
1ab8509a
AM
1850 bool "Fault-injection framework"
1851 depends on DEBUG_KERNEL
329409ae
AM
1852 help
1853 Provide fault-injection framework.
1854 For more details, see Documentation/fault-injection/.
6ff1cb35 1855
8a8b6502 1856config FAILSLAB
1ab8509a
AM
1857 bool "Fault-injection capability for kmalloc"
1858 depends on FAULT_INJECTION
773ff60e 1859 depends on SLAB || SLUB
8a8b6502 1860 help
1ab8509a 1861 Provide fault-injection capability for kmalloc.
8a8b6502 1862
933e312e 1863config FAIL_PAGE_ALLOC
29b46fa3 1864 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1865 depends on FAULT_INJECTION
933e312e 1866 help
1ab8509a 1867 Provide fault-injection capability for alloc_pages().
933e312e 1868
2c739ced
AL
1869config FAULT_INJECTION_USERCOPY
1870 bool "Fault injection capability for usercopy functions"
1871 depends on FAULT_INJECTION
1872 help
1873 Provides fault-injection capability to inject failures
1874 in usercopy functions (copy_from_user(), get_user(), ...).
1875
c17bb495 1876config FAIL_MAKE_REQUEST
86327d19 1877 bool "Fault-injection capability for disk IO"
581d4e28 1878 depends on FAULT_INJECTION && BLOCK
c17bb495 1879 help
1ab8509a 1880 Provide fault-injection capability for disk IO.
c17bb495 1881
581d4e28 1882config FAIL_IO_TIMEOUT
f4d01439 1883 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1884 depends on FAULT_INJECTION && BLOCK
1885 help
1886 Provide fault-injection capability on end IO handling. This
1887 will make the block layer "forget" an interrupt as configured,
1888 thus exercising the error handling.
1889
1890 Only works with drivers that use the generic timeout handling,
1891 for others it wont do anything.
1892
ab51fbab
DB
1893config FAIL_FUTEX
1894 bool "Fault-injection capability for futexes"
1895 select DEBUG_FS
1896 depends on FAULT_INJECTION && FUTEX
1897 help
1898 Provide fault-injection capability for futexes.
1899
f1b4bd06
MP
1900config FAULT_INJECTION_DEBUG_FS
1901 bool "Debugfs entries for fault-injection capabilities"
1902 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1903 help
1904 Enable configuration of fault-injection capabilities via debugfs.
1905
4b1a29a7
MH
1906config FAIL_FUNCTION
1907 bool "Fault-injection capability for functions"
1908 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1909 help
1910 Provide function-based fault-injection capability.
1911 This will allow you to override a specific function with a return
1912 with given return value. As a result, function caller will see
1913 an error value and have to handle it. This is useful to test the
1914 error handling in various subsystems.
1915
f1b4bd06
MP
1916config FAIL_MMC_REQUEST
1917 bool "Fault-injection capability for MMC IO"
1918 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1919 help
f1b4bd06
MP
1920 Provide fault-injection capability for MMC IO.
1921 This will make the mmc core return data errors. This is
1922 useful to test the error handling in the mmc block device
1923 and to test how the mmc host driver handles retries from
1924 the block device.
1df49008
AM
1925
1926config FAULT_INJECTION_STACKTRACE_FILTER
1927 bool "stacktrace filter for fault-injection capabilities"
1928 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 1929 depends on !X86_64
1df49008 1930 select STACKTRACE
f9b58e8c 1931 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1df49008
AM
1932 help
1933 Provide stacktrace filter for fault-injection capabilities
267c4025 1934
09a74952
CD
1935config ARCH_HAS_KCOV
1936 bool
cc3fa840 1937 help
09a74952
CD
1938 An architecture should select this when it can successfully
1939 build and run with CONFIG_KCOV. This typically requires
1940 disabling instrumentation for some early boot code.
cc3fa840 1941
09a74952
CD
1942config CC_HAS_SANCOV_TRACE_PC
1943 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 1944
cc3fa840 1945
09a74952
CD
1946config KCOV
1947 bool "Code coverage for fuzzing"
1948 depends on ARCH_HAS_KCOV
1949 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1950 select DEBUG_FS
1951 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1952 help
1953 KCOV exposes kernel code coverage information in a form suitable
1954 for coverage-guided fuzzing (randomized testing).
cc3fa840 1955
09a74952
CD
1956 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1957 different machines and across reboots. If you need stable PC values,
1958 disable RANDOMIZE_BASE.
cc3fa840 1959
09a74952 1960 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 1961
09a74952
CD
1962config KCOV_ENABLE_COMPARISONS
1963 bool "Enable comparison operands collection by KCOV"
1964 depends on KCOV
1965 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1966 help
1967 KCOV also exposes operands of every comparison in the instrumented
1968 code along with operand sizes and PCs of the comparison instructions.
1969 These operands can be used by fuzzing engines to improve the quality
1970 of fuzzing coverage.
cc3fa840 1971
09a74952
CD
1972config KCOV_INSTRUMENT_ALL
1973 bool "Instrument all code by default"
1974 depends on KCOV
1975 default y
1976 help
1977 If you are doing generic system call fuzzing (like e.g. syzkaller),
1978 then you will want to instrument the whole kernel and you should
1979 say y here. If you are doing more targeted fuzzing (like e.g.
1980 filesystem fuzzing with AFL) then you will want to enable coverage
1981 for more specific subsets of files, and should say n here.
84bc809e 1982
5ff3b30a
AK
1983config KCOV_IRQ_AREA_SIZE
1984 hex "Size of interrupt coverage collection area in words"
1985 depends on KCOV
1986 default 0x40000
1987 help
1988 KCOV uses preallocated per-cpu areas to collect coverage from
1989 soft interrupts. This specifies the size of those areas in the
1990 number of unsigned long words.
1991
d3deafaa
VL
1992menuconfig RUNTIME_TESTING_MENU
1993 bool "Runtime Testing"
908009e8 1994 def_bool y
d3deafaa
VL
1995
1996if RUNTIME_TESTING_MENU
881c5149
DH
1997
1998config LKDTM
1999 tristate "Linux Kernel Dump Test Tool Module"
2000 depends on DEBUG_FS
881c5149
DH
2001 help
2002 This module enables testing of the different dumping mechanisms by
2003 inducing system failures at predefined crash points.
2004 If you don't need it: say N
2005 Choose M here to compile this code as a module. The module will be
2006 called lkdtm.
2007
2008 Documentation on how to use the module can be found in
10ffebbe 2009 Documentation/fault-injection/provoke-crashes.rst
881c5149
DH
2010
2011config TEST_LIST_SORT
e327fd7c
GU
2012 tristate "Linked list sorting test"
2013 depends on DEBUG_KERNEL || m
881c5149
DH
2014 help
2015 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
2016 executed only once during system boot (so affects only boot time),
2017 or at module load time.
881c5149
DH
2018
2019 If unsure, say N.
2020
6e24628d
IR
2021config TEST_MIN_HEAP
2022 tristate "Min heap test"
2023 depends on DEBUG_KERNEL || m
2024 help
2025 Enable this to turn on min heap function tests. This test is
2026 executed only once during system boot (so affects only boot time),
2027 or at module load time.
2028
2029 If unsure, say N.
2030
c5adae95 2031config TEST_SORT
5c4e6798
GU
2032 tristate "Array-based sort test"
2033 depends on DEBUG_KERNEL || m
c5adae95 2034 help
5c4e6798
GU
2035 This option enables the self-test function of 'sort()' at boot,
2036 or at module load time.
c5adae95
KF
2037
2038 If unsure, say N.
2039
881c5149
DH
2040config KPROBES_SANITY_TEST
2041 bool "Kprobes sanity tests"
2042 depends on DEBUG_KERNEL
2043 depends on KPROBES
881c5149
DH
2044 help
2045 This option provides for testing basic kprobes functionality on
5a6cf77f 2046 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
2047 verified for functionality.
2048
2049 Say N if you are unsure.
2050
2051config BACKTRACE_SELF_TEST
2052 tristate "Self test for the backtrace code"
2053 depends on DEBUG_KERNEL
881c5149
DH
2054 help
2055 This option provides a kernel module that can be used to test
2056 the kernel stack backtrace code. This option is not useful
2057 for distributions or general kernels, but only for kernel
2058 developers working on architecture code.
2059
2060 Note that if you want to also test saved backtraces, you will
2061 have to enable STACKTRACE as well.
2062
2063 Say N if you are unsure.
2064
910a742d
ML
2065config RBTREE_TEST
2066 tristate "Red-Black tree test"
7c993e11 2067 depends on DEBUG_KERNEL
910a742d
ML
2068 help
2069 A benchmark measuring the performance of the rbtree library.
2070 Also includes rbtree invariant checks.
2071
4b4f3acc
FB
2072config REED_SOLOMON_TEST
2073 tristate "Reed-Solomon library test"
2074 depends on DEBUG_KERNEL || m
2075 select REED_SOLOMON
2076 select REED_SOLOMON_ENC16
2077 select REED_SOLOMON_DEC16
2078 help
2079 This option enables the self-test function of rslib at boot,
2080 or at module load time.
2081
2082 If unsure, say N.
2083
fff3fd8a
ML
2084config INTERVAL_TREE_TEST
2085 tristate "Interval tree test"
0f789b67 2086 depends on DEBUG_KERNEL
a88cc108 2087 select INTERVAL_TREE
fff3fd8a
ML
2088 help
2089 A benchmark measuring the performance of the interval tree library
2090
623fd807
GT
2091config PERCPU_TEST
2092 tristate "Per cpu operations test"
2093 depends on m && DEBUG_KERNEL
2094 help
2095 Enable this option to build test module which validates per-cpu
2096 operations.
2097
2098 If unsure, say N.
2099
881c5149 2100config ATOMIC64_SELFTEST
55ded955 2101 tristate "Perform an atomic64_t self-test"
881c5149 2102 help
55ded955
GU
2103 Enable this option to test the atomic64_t functions at boot or
2104 at module load time.
881c5149
DH
2105
2106 If unsure, say N.
2107
2108config ASYNC_RAID6_TEST
2109 tristate "Self test for hardware accelerated raid6 recovery"
2110 depends on ASYNC_RAID6_RECOV
2111 select ASYNC_MEMCPY
a7f7f624 2112 help
881c5149
DH
2113 This is a one-shot self test that permutes through the
2114 recovery of all the possible two disk failure scenarios for a
2115 N-disk array. Recovery is performed with the asynchronous
2116 raid6 recovery routines, and will optionally use an offload
2117 engine if one is available.
2118
2119 If unsure, say N.
2120
64d1d77a
AS
2121config TEST_HEXDUMP
2122 tristate "Test functions located in the hexdump module at runtime"
2123
881c5149
DH
2124config TEST_STRING_HELPERS
2125 tristate "Test functions located in the string_helpers module at runtime"
2126
0b0600c8
TH
2127config TEST_STRSCPY
2128 tristate "Test strscpy*() family of functions at runtime"
2129
881c5149
DH
2130config TEST_KSTRTOX
2131 tristate "Test kstrto*() family of functions at runtime"
2132
707cc728
RV
2133config TEST_PRINTF
2134 tristate "Test printf() family of functions at runtime"
2135
5fd003f5
DD
2136config TEST_BITMAP
2137 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2138 help
2139 Enable this option to test the bitmap functions at boot.
2140
2141 If unsure, say N.
2142
cfaff0e5
AS
2143config TEST_UUID
2144 tristate "Test functions located in the uuid module at runtime"
2145
ad3d6c72
MW
2146config TEST_XARRAY
2147 tristate "Test the XArray code at runtime"
2148
455a35a6
RV
2149config TEST_OVERFLOW
2150 tristate "Test check_*_overflow() functions at runtime"
2151
7e1e7763 2152config TEST_RHASHTABLE
9d6dbe1b 2153 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2154 help
2155 Enable this option to test the rhashtable functions at boot.
2156
2157 If unsure, say N.
2158
468a9428
GS
2159config TEST_HASH
2160 tristate "Perform selftest on hash functions"
468a9428 2161 help
2c956a60
JD
2162 Enable this option to test the kernel's integer (<linux/hash.h>),
2163 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2164 hash functions on boot (or module load).
468a9428
GS
2165
2166 This is intended to help people writing architecture-specific
2167 optimized versions. If unsure, say N.
2168
8ab8ba38
MW
2169config TEST_IDA
2170 tristate "Perform selftest on IDA functions"
2171
44091d29
JP
2172config TEST_PARMAN
2173 tristate "Perform selftest on priority array manager"
44091d29
JP
2174 depends on PARMAN
2175 help
2176 Enable this option to test priority array manager on boot
2177 (or module load).
2178
2179 If unsure, say N.
2180
6aed82de
DL
2181config TEST_IRQ_TIMINGS
2182 bool "IRQ timings selftest"
2183 depends on IRQ_TIMINGS
2184 help
2185 Enable this option to test the irq timings code on boot.
2186
2187 If unsure, say N.
2188
8a6f0b47 2189config TEST_LKM
93e9ef83 2190 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2191 depends on m
2192 help
2193 This builds the "test_module" module that emits "Hello, world"
2194 on printk when loaded. It is designed to be used for basic
2195 evaluation of the module loading subsystem (for example when
2196 validating module verification). It lacks any extra dependencies,
2197 and will not normally be loaded by the system unless explicitly
2198 requested by name.
2199
2200 If unsure, say N.
2201
c348c163 2202config TEST_BITOPS
6af132f3 2203 tristate "Test module for compilation of bitops operations"
c348c163
JB
2204 depends on m
2205 help
2206 This builds the "test_bitops" module that is much like the
2207 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2208 set/clear_bit macros and get_count_order/long to make sure there are
2209 no compiler warnings from C=1 sparse checker or -Wextra
2210 compilations. It has no dependencies and doesn't run or load unless
2211 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2212
2213 If unsure, say N.
2214
3f21a6b7
URS
2215config TEST_VMALLOC
2216 tristate "Test module for stress/performance analysis of vmalloc allocator"
2217 default n
2218 depends on MMU
2219 depends on m
2220 help
2221 This builds the "test_vmalloc" module that should be used for
2222 stress and performance analysis. So, any new change for vmalloc
2223 subsystem can be evaluated from performance and stability point
2224 of view.
2225
2226 If unsure, say N.
2227
3e2a4c18
KC
2228config TEST_USER_COPY
2229 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2230 depends on m
2231 help
2232 This builds the "test_user_copy" module that runs sanity checks
2233 on the copy_to/from_user infrastructure, making sure basic
2234 user/kernel boundary testing is working. If it fails to load,
2235 a regression has been detected in the user/kernel memory boundary
2236 protections.
2237
2238 If unsure, say N.
2239
64a8946b
AS
2240config TEST_BPF
2241 tristate "Test BPF filter functionality"
98920ba6 2242 depends on m && NET
64a8946b
AS
2243 help
2244 This builds the "test_bpf" module that runs various test vectors
2245 against the BPF interpreter or BPF JIT compiler depending on the
2246 current setting. This is in particular useful for BPF JIT compiler
2247 development, but also to run regression tests against changes in
3c731eba
AS
2248 the interpreter code. It also enables test stubs for eBPF maps and
2249 verifier used by user space verifier testsuite.
64a8946b
AS
2250
2251 If unsure, say N.
2252
509e56b3
MB
2253config TEST_BLACKHOLE_DEV
2254 tristate "Test blackhole netdev functionality"
2255 depends on m && NET
2256 help
2257 This builds the "test_blackhole_dev" module that validates the
2258 data path through this blackhole netdev.
2259
2260 If unsure, say N.
2261
dceeb3e7 2262config FIND_BIT_BENCHMARK
4441fca0 2263 tristate "Test find_bit functions"
4441fca0
YN
2264 help
2265 This builds the "test_find_bit" module that measure find_*_bit()
2266 functions performance.
2267
2268 If unsure, say N.
2269
0a8adf58
KC
2270config TEST_FIRMWARE
2271 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2272 depends on FW_LOADER
2273 help
2274 This builds the "test_firmware" module that creates a userspace
2275 interface for testing firmware loading. This can be used to
2276 control the triggering of firmware loading without needing an
2277 actual firmware-using device. The contents can be rechecked by
2278 userspace.
2279
2280 If unsure, say N.
2281
9308f2f9
LR
2282config TEST_SYSCTL
2283 tristate "sysctl test driver"
9308f2f9
LR
2284 depends on PROC_SYSCTL
2285 help
2286 This builds the "test_sysctl" module. This driver enables to test the
2287 proc sysctl interfaces available to drivers safely without affecting
2288 production knobs which might alter system functionality.
2289
2290 If unsure, say N.
2291
d2585f51
VMI
2292config BITFIELD_KUNIT
2293 tristate "KUnit test bitfield functions at runtime"
2294 depends on KUNIT
2295 help
2296 Enable this option to test the bitfield functions at boot.
2297
2298 KUnit tests run during boot and output the results to the debug log
2299 in TAP format (http://testanything.org/). Only useful for kernel devs
2300 running the KUnit test harness, and not intended for inclusion into a
2301 production build.
2302
2303 For more information on KUnit and unit tests in general please refer
2304 to the KUnit documentation in Documentation/dev-tools/kunit/.
2305
2306 If unsure, say N.
2307
5df38ca6
AS
2308config RESOURCE_KUNIT_TEST
2309 tristate "KUnit test for resource API"
2310 depends on KUNIT
2311 help
2312 This builds the resource API unit test.
2313 Tests the logic of API provided by resource.c and ioport.h.
2314 For more information on KUnit and unit tests in general please refer
2315 to the KUnit documentation in Documentation/dev-tools/kunit/.
2316
2317 If unsure, say N.
2318
2cb80dbb 2319config SYSCTL_KUNIT_TEST
5f215aab 2320 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2321 depends on KUNIT
5f215aab 2322 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2323 help
2324 This builds the proc sysctl unit test, which runs on boot.
2325 Tests the API contract and implementation correctness of sysctl.
2326 For more information on KUnit and unit tests in general please refer
2327 to the KUnit documentation in Documentation/dev-tools/kunit/.
2328
2329 If unsure, say N.
2330
ea2dd7c0 2331config LIST_KUNIT_TEST
5f215aab 2332 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2333 depends on KUNIT
5f215aab 2334 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2335 help
2336 This builds the linked list KUnit test suite.
2337 It tests that the API and basic functionality of the list_head type
2338 and associated macros.
2339
2340 KUnit tests run during boot and output the results to the debug log
d89775fc 2341 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2342 running the KUnit test harness, and not intended for inclusion into a
2343 production build.
2344
2345 For more information on KUnit and unit tests in general please refer
2346 to the KUnit documentation in Documentation/dev-tools/kunit/.
2347
2348 If unsure, say N.
2349
33d599f0
MV
2350config LINEAR_RANGES_TEST
2351 tristate "KUnit test for linear_ranges"
2352 depends on KUNIT
2353 select LINEAR_RANGES
2354 help
2355 This builds the linear_ranges unit test, which runs on boot.
2356 Tests the linear_ranges logic correctness.
2357 For more information on KUnit and unit tests in general please refer
7546861a
AS
2358 to the KUnit documentation in Documentation/dev-tools/kunit/.
2359
2360 If unsure, say N.
2361
2362config CMDLINE_KUNIT_TEST
2363 tristate "KUnit test for cmdline API"
2364 depends on KUNIT
2365 help
2366 This builds the cmdline API unit test.
2367 Tests the logic of API provided by cmdline.c.
2368 For more information on KUnit and unit tests in general please refer
33d599f0
MV
2369 to the KUnit documentation in Documentation/dev-tools/kunit/.
2370
2371 If unsure, say N.
2372
6d511020
RF
2373config BITS_TEST
2374 tristate "KUnit test for bits.h"
2375 depends on KUNIT
2376 help
2377 This builds the bits unit test.
2378 Tests the logic of macros defined in bits.h.
2379 For more information on KUnit and unit tests in general please refer
2380 to the KUnit documentation in Documentation/dev-tools/kunit/.
2381
2382 If unsure, say N.
2383
e704f93a
DR
2384config TEST_UDELAY
2385 tristate "udelay test driver"
e704f93a
DR
2386 help
2387 This builds the "udelay_test" module that helps to make sure
2388 that udelay() is working properly.
2389
2390 If unsure, say N.
2391
2bf9e0ab
IM
2392config TEST_STATIC_KEYS
2393 tristate "Test static keys"
579e1acb
JB
2394 depends on m
2395 help
2bf9e0ab 2396 Test the static key interfaces.
579e1acb
JB
2397
2398 If unsure, say N.
2399
d9c6a72d
LR
2400config TEST_KMOD
2401 tristate "kmod stress tester"
d9c6a72d 2402 depends on m
d9c6a72d 2403 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2404 depends on BLOCK
d9c6a72d
LR
2405 select TEST_LKM
2406 select XFS_FS
2407 select TUN
2408 select BTRFS_FS
2409 help
2410 Test the kernel's module loading mechanism: kmod. kmod implements
2411 support to load modules using the Linux kernel's usermode helper.
2412 This test provides a series of tests against kmod.
2413
2414 Although technically you can either build test_kmod as a module or
2415 into the kernel we disallow building it into the kernel since
2416 it stress tests request_module() and this will very likely cause
2417 some issues by taking over precious threads available from other
2418 module load requests, ultimately this could be fatal.
2419
2420 To run tests run:
2421
2422 tools/testing/selftests/kmod/kmod.sh --help
2423
2424 If unsure, say N.
2425
e4dace36
FF
2426config TEST_DEBUG_VIRTUAL
2427 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2428 depends on DEBUG_VIRTUAL
2429 help
2430 Test the kernel's ability to detect incorrect calls to
2431 virt_to_phys() done against the non-linear part of the
2432 kernel's virtual address map.
2433
2434 If unsure, say N.
2435
ce76d938
AS
2436config TEST_MEMCAT_P
2437 tristate "Test memcat_p() helper function"
2438 help
2439 Test the memcat_p() helper for correctly merging two
2440 pointer arrays together.
2441
2442 If unsure, say N.
2443
a2818ee4
JL
2444config TEST_LIVEPATCH
2445 tristate "Test livepatching"
2446 default n
bae05437 2447 depends on DYNAMIC_DEBUG
a2818ee4
JL
2448 depends on LIVEPATCH
2449 depends on m
2450 help
2451 Test kernel livepatching features for correctness. The tests will
2452 load test modules that will be livepatched in various scenarios.
2453
2454 To run all the livepatching tests:
2455
2456 make -C tools/testing/selftests TARGETS=livepatch run_tests
2457
2458 Alternatively, individual tests may be invoked:
2459
2460 tools/testing/selftests/livepatch/test-callbacks.sh
2461 tools/testing/selftests/livepatch/test-livepatch.sh
2462 tools/testing/selftests/livepatch/test-shadow-vars.sh
2463
2464 If unsure, say N.
2465
0a020d41
JP
2466config TEST_OBJAGG
2467 tristate "Perform selftest on object aggreration manager"
2468 default n
2469 depends on OBJAGG
2470 help
2471 Enable this option to test object aggregation manager on boot
2472 (or module load).
2473
0a020d41 2474
50ceaa95
KC
2475config TEST_STACKINIT
2476 tristate "Test level of stack variable initialization"
2477 help
2478 Test if the kernel is zero-initializing stack variables and
2479 padding. Coverage is controlled by compiler flags,
2480 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2481 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2482
2483 If unsure, say N.
2484
5015a300
AP
2485config TEST_MEMINIT
2486 tristate "Test heap/page initialization"
2487 help
2488 Test if the kernel is zero-initializing heap and page allocations.
2489 This can be useful to test init_on_alloc and init_on_free features.
2490
2491 If unsure, say N.
2492
b2ef9f5a
RC
2493config TEST_HMM
2494 tristate "Test HMM (Heterogeneous Memory Management)"
2495 depends on TRANSPARENT_HUGEPAGE
2496 depends on DEVICE_PRIVATE
2497 select HMM_MIRROR
2498 select MMU_NOTIFIER
2499 help
2500 This is a pseudo device driver solely for testing HMM.
2501 Say M here if you want to build the HMM test module.
2502 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2503
2504 If unsure, say N.
2505
e320d301
MWO
2506config TEST_FREE_PAGES
2507 tristate "Test freeing pages"
2508 help
2509 Test that a memory leak does not occur due to a race between
2510 freeing a block of pages and a speculative page reference.
2511 Loading this module is safe if your kernel has the bug fixed.
2512 If the bug is not fixed, it will leak gigabytes of memory and
2513 probably OOM your system.
2514
4185b3b9
PA
2515config TEST_FPU
2516 tristate "Test floating point operations in kernel space"
2517 depends on X86 && !KCOV_INSTRUMENT_ALL
2518 help
2519 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2520 which will trigger a sequence of floating point operations. This is used
2521 for self-testing floating point control register setting in
2522 kernel_fpu_begin().
2523
2524 If unsure, say N.
2525
d3deafaa 2526endif # RUNTIME_TESTING_MENU
cc3fa840
RD
2527
2528config MEMTEST
2529 bool "Memtest"
a7f7f624 2530 help
cc3fa840
RD
2531 This option adds a kernel parameter 'memtest', which allows memtest
2532 to be set.
2533 memtest=0, mean disabled; -- default
2534 memtest=1, mean do 1 test pattern;
2535 ...
2536 memtest=17, mean do 17 test patterns.
2537 If you are unsure how to answer this question, answer N.
2538
21266be9 2539
06ec64b8 2540
af9ca6f9
BB
2541config HYPERV_TESTING
2542 bool "Microsoft Hyper-V driver testing"
2543 default n
2544 depends on HYPERV && DEBUG_FS
2545 help
2546 Select this option to enable Hyper-V vmbus testing.
2547
045f6d79
CD
2548endmenu # "Kernel Testing and Coverage"
2549
75442fb0
MCC
2550source "Documentation/Kconfig"
2551
06ec64b8 2552endmenu # Kernel hacking