bpf, arm64: Feed byte-offset into bpf line info
[linux-2.6-block.git] / lib / Kconfig.debug
CommitLineData
ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
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21config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
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38config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
40 depends on PRINTK
41 help
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
44
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
48
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49config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
51 range 1 15
52 default "7"
53 help
54 Default loglevel to determine what will be printed on the console.
55
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
59
50f4d9bd 60 Note: This does not affect the log level of un-prefixed printk()
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61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option.
63
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64config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
66 range 1 15
67 default "4"
68 help
69 loglevel to use when "quiet" is passed on the kernel commandline.
70
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74
42a9dc0b 75config MESSAGE_LOGLEVEL_DEFAULT
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76 int "Default message log level (1-7)"
77 range 1 7
78 default "4"
79 help
80 Default log level for printk statements with no specified priority.
81
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
84 priority.
85
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86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89
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90config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
97 using "boot_delay=N".
98
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
107
108config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support"
110 default n
111 depends on PRINTK
239a5791 112 depends on (DEBUG_FS || PROC_FS)
ceabef7d 113 select DYNAMIC_DEBUG_CORE
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114 help
115
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
122
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
127
128 Usage:
129
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
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134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
137
138 filename:lineno [module]function flags format
139
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
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144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
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146
147 From a live system:
148
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154
155 Example usage:
156
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
160
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
164
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
168
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
172
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
176
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177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information.
604ff0dc 179
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180config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
182 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS)
184 help
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
190
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191config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
193 default y if PRINTK
194 help
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
199
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200config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y
204 help
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
208
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209endmenu # "printk and dmesg options"
210
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211menu "Compile-time checks and compiler options"
212
213config DEBUG_INFO
214 bool "Compile the kernel with debug info"
12b13835 215 depends on DEBUG_KERNEL && !COMPILE_TEST
6dfc0665 216 help
68d4b3df 217 If you say Y here the resulting kernel image will include
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218 debugging info resulting in a larger kernel image.
219 This adds debug symbols to the kernel and modules (gcc -g), and
220 is needed if you intend to use kernel crashdump or binary object
221 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
222 Say Y here only if you plan to debug the kernel.
223
224 If unsure, say N.
225
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226if DEBUG_INFO
227
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228config DEBUG_INFO_REDUCED
229 bool "Reduce debugging information"
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230 help
231 If you say Y here gcc is instructed to generate less debugging
232 information for structure types. This means that tools that
233 need full debugging information (like kgdb or systemtap) won't
234 be happy. But if you merely need debugging information to
235 resolve line numbers there is no loss. Advantage is that
236 build directory object sizes shrink dramatically over a full
237 DEBUG_INFO build and compile times are reduced too.
238 Only works with newer gcc versions.
239
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240config DEBUG_INFO_COMPRESSED
241 bool "Compressed debugging information"
10e68b02 242 depends on $(cc-option,-gz=zlib)
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243 depends on $(ld-option,--compress-debug-sections=zlib)
244 help
245 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
246 5.0+, binutils 2.26+, and zlib.
247
248 Users of dpkg-deb via scripts/package/builddeb may find an increase in
249 size of their debug .deb packages with this config set, due to the
250 debug info being compressed with zlib, then the object files being
251 recompressed with a different compression scheme. But this is still
252 preferable to setting $KDEB_COMPRESS to "none" which would be even
253 larger.
254
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255config DEBUG_INFO_SPLIT
256 bool "Produce split debuginfo in .dwo files"
9d937444 257 depends on $(cc-option,-gsplit-dwarf)
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258 help
259 Generate debug info into separate .dwo files. This significantly
260 reduces the build directory size for builds with DEBUG_INFO,
261 because it stores the information only once on disk in .dwo
262 files instead of multiple times in object files and executables.
263 In addition the debug information is also compressed.
264
265 Requires recent gcc (4.7+) and recent gdb/binutils.
266 Any tool that packages or reads debug information would need
267 to know about the .dwo files and include them.
268 Incompatible with older versions of ccache.
269
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270choice
271 prompt "DWARF version"
272 help
273 Which version of DWARF debug info to emit.
274
275config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
276 bool "Rely on the toolchain's implicit default DWARF version"
277 help
278 The implicit default version of DWARF debug info produced by a
279 toolchain changes over time.
280
281 This can break consumers of the debug info that haven't upgraded to
282 support newer revisions, and prevent testing newer versions, but
283 those should be less common scenarios.
284
285 If unsure, say Y.
286
bfaf2dd3 287config DEBUG_INFO_DWARF4
a66049e2 288 bool "Generate DWARF Version 4 debuginfo"
bfaf2dd3 289 help
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290 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
291
292 If you have consumers of DWARF debug info that are not ready for
293 newer revisions of DWARF, you may wish to choose this or have your
294 config select this.
295
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296config DEBUG_INFO_DWARF5
297 bool "Generate DWARF Version 5 debuginfo"
c0a5c81c 298 depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
42d9b379 299 depends on !DEBUG_INFO_BTF || PAHOLE_VERSION >= 121
bfaf2dd3 300 help
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301 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
302 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
303 draft features until 7.0), and gdb 8.0+.
304
305 Changes to the structure of debug info in Version 5 allow for around
306 15-18% savings in resulting image and debug info section sizes as
307 compared to DWARF Version 4. DWARF Version 5 standardizes previous
308 extensions such as accelerators for symbol indexing and the format
309 for fission (.dwo/.dwp) files. Users may not want to select this
310 config if they rely on tooling that has not yet been updated to
311 support DWARF Version 5.
312
a66049e2 313endchoice # "DWARF version"
bfaf2dd3 314
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315config DEBUG_INFO_BTF
316 bool "Generate BTF typeinfo"
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317 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
318 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
d9847eb8 319 depends on BPF_SYSCALL
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320 help
321 Generate deduplicated BTF type information from DWARF debug info.
322 Turning this on expects presence of pahole tool, which will convert
323 DWARF type info into equivalent deduplicated BTF type info.
324
5f9ae91f 325config PAHOLE_HAS_SPLIT_BTF
6323c813 326 def_bool PAHOLE_VERSION >= 119
5f9ae91f 327
7472d5a6 328config PAHOLE_HAS_BTF_TAG
6323c813 329 def_bool PAHOLE_VERSION >= 123
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330 depends on CC_IS_CLANG
331 help
332 Decide whether pahole emits btf_tag attributes (btf_type_tag and
333 btf_decl_tag) or not. Currently only clang compiler implements
334 these attributes, so make the config depend on CC_IS_CLANG.
335
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336config DEBUG_INFO_BTF_MODULES
337 def_bool y
338 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
339 help
340 Generate compact split BTF type information for kernel modules.
341
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342config GDB_SCRIPTS
343 bool "Provide GDB scripts for kernel debugging"
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344 help
345 This creates the required links to GDB helper scripts in the
346 build directory. If you load vmlinux into gdb, the helper
347 scripts will be automatically imported by gdb as well, and
348 additional functions are available to analyze a Linux kernel
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349 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
350 for further details.
3ee7b3fa 351
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352endif # DEBUG_INFO
353
35bb5b1e 354config FRAME_WARN
a83e4ca2 355 int "Warn for stack frames larger than"
35bb5b1e 356 range 0 8192
0e07f663 357 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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358 default 2048 if PARISC
359 default 1536 if (!64BIT && XTENSA)
360 default 1024 if !64BIT
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361 default 2048 if 64BIT
362 help
363 Tell gcc to warn at build time for stack frames larger than this.
364 Setting this too low will cause a lot of warnings.
365 Setting it to 0 disables the warning.
35bb5b1e 366
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367config STRIP_ASM_SYMS
368 bool "Strip assembler-generated symbols during link"
369 default n
370 help
371 Strip internal assembler-generated symbols during a link (symbols
372 that look like '.Lxxx') so they don't pollute the output of
373 get_wchan() and suchlike.
374
1873e870 375config READABLE_ASM
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376 bool "Generate readable assembler code"
377 depends on DEBUG_KERNEL
7d73c3e9 378 depends on CC_IS_GCC
bf4735a4 379 help
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380 Disable some compiler optimizations that tend to generate human unreadable
381 assembler output. This may make the kernel slightly slower, but it helps
382 to keep kernel developers who have to stare a lot at assembler listings
383 sane.
bf4735a4 384
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385config HEADERS_INSTALL
386 bool "Install uapi headers to usr/include"
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387 depends on !UML
388 help
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389 This option will install uapi headers (headers exported to user-space)
390 into the usr/include directory for use during the kernel build.
391 This is unneeded for building the kernel itself, but needed for some
392 user-space program samples. It is also needed by some features such
393 as uapi header sanity checks.
394
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395config DEBUG_SECTION_MISMATCH
396 bool "Enable full Section mismatch analysis"
7d73c3e9 397 depends on CC_IS_GCC
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398 help
399 The section mismatch analysis checks if there are illegal
400 references from one section to another section.
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401 During linktime or runtime, some sections are dropped;
402 any use of code/data previously in these sections would
91341d4b 403 most likely result in an oops.
e809ab01 404 In the code, functions and variables are annotated with
0db0628d 405 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 406 which results in the code/data being placed in specific sections.
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407 The section mismatch analysis is always performed after a full
408 kernel build, and enabling this option causes the following
b7dca6dd 409 additional step to occur:
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410 - Add the option -fno-inline-functions-called-once to gcc commands.
411 When inlining a function annotated with __init in a non-init
412 function, we would lose the section information and thus
91341d4b 413 the analysis would not catch the illegal reference.
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414 This option tells gcc to inline less (but it does result in
415 a larger kernel).
91341d4b 416
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417config SECTION_MISMATCH_WARN_ONLY
418 bool "Make section mismatch errors non-fatal"
419 default y
420 help
421 If you say N here, the build process will fail if there are any
422 section mismatch, instead of just throwing warnings.
423
424 If unsure, say Y.
425
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426config DEBUG_FORCE_FUNCTION_ALIGN_64B
427 bool "Force all function address 64B aligned" if EXPERT
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428 help
429 There are cases that a commit from one domain changes the function
430 address alignment of other domains, and cause magic performance
431 bump (regression or improvement). Enable this option will help to
432 verify if the bump is caused by function alignment changes, while
433 it will slightly increase the kernel size and affect icache usage.
434
435 It is mainly for debug and performance tuning use.
436
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437#
438# Select this config option from the architecture Kconfig, if it
439# is preferred to always offer frame pointers as a config
440# option on the architecture (regardless of KERNEL_DEBUG):
441#
442config ARCH_WANT_FRAME_POINTERS
443 bool
f346f4b3 444
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445config FRAME_POINTER
446 bool "Compile the kernel with frame pointers"
a687a533 447 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 448 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 449 help
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450 If you say Y here the resulting kernel image will be slightly
451 larger and slower, but it gives very useful debugging information
452 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 453
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454config STACK_VALIDATION
455 bool "Compile-time stack metadata validation"
456 depends on HAVE_STACK_VALIDATION
457 default n
458 help
459 Add compile-time checks to validate stack metadata, including frame
460 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
461 that runtime stack traces are more reliable.
462
ee9f8fce 463 This is also a prerequisite for generation of ORC unwind data, which
11af8474 464 is needed for CONFIG_UNWINDER_ORC.
ee9f8fce 465
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466 For more information, see
467 tools/objtool/Documentation/stack-validation.txt.
468
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469config VMLINUX_VALIDATION
470 bool
db2b0c5d 471 depends on STACK_VALIDATION && DEBUG_ENTRY
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472 default y
473
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474config VMLINUX_MAP
475 bool "Generate vmlinux.map file when linking"
476 depends on EXPERT
477 help
478 Selecting this option will pass "-Map=vmlinux.map" to ld
479 when linking vmlinux. That file can be useful for verifying
480 and debugging magic section games, and for seeing which
481 pieces of code get eliminated with
482 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
483
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484config DEBUG_FORCE_WEAK_PER_CPU
485 bool "Force weak per-cpu definitions"
486 depends on DEBUG_KERNEL
8446f1d3 487 help
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488 s390 and alpha require percpu variables in modules to be
489 defined weak to work around addressing range issue which
490 puts the following two restrictions on percpu variable
491 definitions.
8446f1d3 492
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493 1. percpu symbols must be unique whether static or not
494 2. percpu variables can't be defined inside a function
8446f1d3 495
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496 To ensure that generic code follows the above rules, this
497 option forces all percpu variables to be defined as weak.
5f329089 498
6dfc0665 499endmenu # "Compiler options"
8446f1d3 500
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501menu "Generic Kernel Debugging Instruments"
502
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503config MAGIC_SYSRQ
504 bool "Magic SysRq key"
505 depends on !UML
506 help
507 If you say Y here, you will have some control over the system even
508 if the system crashes for example during kernel debugging (e.g., you
509 will be able to flush the buffer cache to disk, reboot the system
510 immediately or dump some status information). This is accomplished
511 by pressing various keys while holding SysRq (Alt+PrintScreen). It
512 also works on a serial console (on PC hardware at least), if you
513 send a BREAK and then within 5 seconds a command keypress. The
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514 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
515 Don't say Y unless you really know what this hack does.
8446f1d3 516
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517config MAGIC_SYSRQ_DEFAULT_ENABLE
518 hex "Enable magic SysRq key functions by default"
519 depends on MAGIC_SYSRQ
520 default 0x1
521 help
522 Specifies which SysRq key functions are enabled by default.
523 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 524 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 525
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526config MAGIC_SYSRQ_SERIAL
527 bool "Enable magic SysRq key over serial"
528 depends on MAGIC_SYSRQ
529 default y
530 help
531 Many embedded boards have a disconnected TTL level serial which can
532 generate some garbage that can lead to spurious false sysrq detects.
533 This option allows you to decide whether you want to enable the
534 magic SysRq key.
535
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536config MAGIC_SYSRQ_SERIAL_SEQUENCE
537 string "Char sequence that enables magic SysRq over serial"
538 depends on MAGIC_SYSRQ_SERIAL
539 default ""
540 help
541 Specifies a sequence of characters that can follow BREAK to enable
542 SysRq on a serial console.
543
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544 If unsure, leave an empty string and the option will not be enabled.
545
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546config DEBUG_FS
547 bool "Debug Filesystem"
548 help
549 debugfs is a virtual file system that kernel developers use to put
550 debugging files into. Enable this option to be able to read and
551 write to these files.
552
553 For detailed documentation on the debugfs API, see
554 Documentation/filesystems/.
555
556 If unsure, say N.
557
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558choice
559 prompt "Debugfs default access"
560 depends on DEBUG_FS
561 default DEBUG_FS_ALLOW_ALL
562 help
563 This selects the default access restrictions for debugfs.
564 It can be overridden with kernel command line option
565 debugfs=[on,no-mount,off]. The restrictions apply for API access
566 and filesystem registration.
567
568config DEBUG_FS_ALLOW_ALL
569 bool "Access normal"
570 help
571 No restrictions apply. Both API and filesystem registration
572 is on. This is the normal default operation.
573
574config DEBUG_FS_DISALLOW_MOUNT
575 bool "Do not register debugfs as filesystem"
576 help
577 The API is open but filesystem is not loaded. Clients can still do
578 their work and read with debug tools that do not need
579 debugfs filesystem.
580
581config DEBUG_FS_ALLOW_NONE
582 bool "No access"
583 help
584 Access is off. Clients get -PERM when trying to create nodes in
585 debugfs tree and debugfs is not registered as a filesystem.
586 Client can then back-off or continue without debugfs access.
587
588endchoice
589
6210b640 590source "lib/Kconfig.kgdb"
6210b640 591source "lib/Kconfig.ubsan"
2645d432 592source "lib/Kconfig.kcsan"
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593
594endmenu
595
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596config DEBUG_KERNEL
597 bool "Kernel debugging"
fef2c9bc 598 help
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599 Say Y here if you are developing drivers or trying to debug and
600 identify kernel problems.
fef2c9bc 601
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602config DEBUG_MISC
603 bool "Miscellaneous debug code"
604 default DEBUG_KERNEL
605 depends on DEBUG_KERNEL
606 help
607 Say Y here if you need to enable miscellaneous debug code that should
608 be under a more specific debug option but isn't.
609
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ED
610menu "Networking Debugging"
611
612source "net/Kconfig.debug"
613
614endmenu # "Networking Debugging"
c66d7a27 615
0610c8a8 616menu "Memory Debugging"
fef2c9bc 617
8636a1f9 618source "mm/Kconfig.debug"
fef2c9bc 619
0610c8a8
DH
620config DEBUG_OBJECTS
621 bool "Debug object operations"
622 depends on DEBUG_KERNEL
9c44bc03 623 help
0610c8a8
DH
624 If you say Y here, additional code will be inserted into the
625 kernel to track the life time of various objects and validate
626 the operations on those objects.
9c44bc03 627
0610c8a8
DH
628config DEBUG_OBJECTS_SELFTEST
629 bool "Debug objects selftest"
630 depends on DEBUG_OBJECTS
631 help
632 This enables the selftest of the object debug code.
9c44bc03 633
0610c8a8
DH
634config DEBUG_OBJECTS_FREE
635 bool "Debug objects in freed memory"
636 depends on DEBUG_OBJECTS
637 help
638 This enables checks whether a k/v free operation frees an area
639 which contains an object which has not been deactivated
640 properly. This can make kmalloc/kfree-intensive workloads
641 much slower.
3ac7fe5a 642
c6f3a97f
TG
643config DEBUG_OBJECTS_TIMERS
644 bool "Debug timer objects"
645 depends on DEBUG_OBJECTS
646 help
647 If you say Y here, additional code will be inserted into the
648 timer routines to track the life time of timer objects and
649 validate the timer operations.
650
dc186ad7
TG
651config DEBUG_OBJECTS_WORK
652 bool "Debug work objects"
653 depends on DEBUG_OBJECTS
654 help
655 If you say Y here, additional code will be inserted into the
656 work queue routines to track the life time of work objects and
657 validate the work operations.
658
551d55a9
MD
659config DEBUG_OBJECTS_RCU_HEAD
660 bool "Debug RCU callbacks objects"
fc2ecf7e 661 depends on DEBUG_OBJECTS
551d55a9
MD
662 help
663 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
664
e2852ae8
TH
665config DEBUG_OBJECTS_PERCPU_COUNTER
666 bool "Debug percpu counter objects"
667 depends on DEBUG_OBJECTS
668 help
669 If you say Y here, additional code will be inserted into the
670 percpu counter routines to track the life time of percpu counter
671 objects and validate the percpu counter operations.
672
3ae70205
IM
673config DEBUG_OBJECTS_ENABLE_DEFAULT
674 int "debug_objects bootup default value (0-1)"
68d4b3df
KK
675 range 0 1
676 default "1"
677 depends on DEBUG_OBJECTS
678 help
679 Debug objects boot parameter default value
3ae70205 680
1da177e4 681config DEBUG_SLAB
4a2f0acf 682 bool "Debug slab memory allocations"
4675ff05 683 depends on DEBUG_KERNEL && SLAB
1da177e4
LT
684 help
685 Say Y here to have the kernel do limited verification on memory
686 allocation as well as poisoning memory on free to catch use of freed
687 memory. This can make kmalloc/kfree-intensive workloads much slower.
688
f0630fff
CL
689config SLUB_DEBUG_ON
690 bool "SLUB debugging on by default"
4675ff05 691 depends on SLUB && SLUB_DEBUG
f0630fff
CL
692 default n
693 help
694 Boot with debugging on by default. SLUB boots by default with
695 the runtime debug capabilities switched off. Enabling this is
696 equivalent to specifying the "slub_debug" parameter on boot.
697 There is no support for more fine grained debug control like
698 possible with slub_debug=xxx. SLUB debugging may be switched
699 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
700 "slub_debug=-".
701
8ff12cfc
CL
702config SLUB_STATS
703 default n
704 bool "Enable SLUB performance statistics"
ab4d5ed5 705 depends on SLUB && SYSFS
8ff12cfc
CL
706 help
707 SLUB statistics are useful to debug SLUBs allocation behavior in
708 order find ways to optimize the allocator. This should never be
709 enabled for production use since keeping statistics slows down
710 the allocator by a few percentage points. The slabinfo command
711 supports the determination of the most active slabs to figure
712 out which slabs are relevant to a particular load.
713 Try running: slabinfo -DA
714
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CM
715config HAVE_DEBUG_KMEMLEAK
716 bool
717
3bba00d7
CM
718config DEBUG_KMEMLEAK
719 bool "Kernel memory leak detector"
525c1f92 720 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 721 select DEBUG_FS
3bba00d7
CM
722 select STACKTRACE if STACKTRACE_SUPPORT
723 select KALLSYMS
b60e26a2 724 select CRC32
3bba00d7
CM
725 help
726 Say Y here if you want to enable the memory leak
727 detector. The memory allocation/freeing is traced in a way
728 similar to the Boehm's conservative garbage collector, the
729 difference being that the orphan objects are not freed but
730 only shown in /sys/kernel/debug/kmemleak. Enabling this
731 feature will introduce an overhead to memory
700199b0 732 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
733 details.
734
0610c8a8
DH
735 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
736 of finding leaks due to the slab objects poisoning.
737
738 In order to access the kmemleak file, debugfs needs to be
739 mounted (usually at /sys/kernel/debug).
740
c5665868
CM
741config DEBUG_KMEMLEAK_MEM_POOL_SIZE
742 int "Kmemleak memory pool size"
0610c8a8 743 depends on DEBUG_KMEMLEAK
c59180ae 744 range 200 1000000
b751c52b 745 default 16000
0610c8a8
DH
746 help
747 Kmemleak must track all the memory allocations to avoid
748 reporting false positives. Since memory may be allocated or
c5665868
CM
749 freed before kmemleak is fully initialised, use a static pool
750 of metadata objects to track such callbacks. After kmemleak is
751 fully initialised, this memory pool acts as an emergency one
752 if slab allocations fail.
0610c8a8
DH
753
754config DEBUG_KMEMLEAK_TEST
755 tristate "Simple test for the kernel memory leak detector"
756 depends on DEBUG_KMEMLEAK && m
757 help
758 This option enables a module that explicitly leaks memory.
759
760 If unsure, say N.
761
762config DEBUG_KMEMLEAK_DEFAULT_OFF
763 bool "Default kmemleak to off"
764 depends on DEBUG_KMEMLEAK
765 help
766 Say Y here to disable kmemleak by default. It can then be enabled
767 on the command line via kmemleak=on.
768
d53ce042
SK
769config DEBUG_KMEMLEAK_AUTO_SCAN
770 bool "Enable kmemleak auto scan thread on boot up"
771 default y
772 depends on DEBUG_KMEMLEAK
773 help
774 Depending on the cpu, kmemleak scan may be cpu intensive and can
775 stall user tasks at times. This option enables/disables automatic
776 kmemleak scan at boot up.
777
778 Say N here to disable kmemleak auto scan thread to stop automatic
779 scanning. Disabling this option disables automatic reporting of
780 memory leaks.
781
782 If unsure, say Y.
783
0610c8a8
DH
784config DEBUG_STACK_USAGE
785 bool "Stack utilization instrumentation"
6c31da34 786 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
787 help
788 Enables the display of the minimum amount of free stack which each
789 task has ever had available in the sysrq-T and sysrq-P debug output.
790
791 This option will slow down process creation somewhat.
792
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CD
793config SCHED_STACK_END_CHECK
794 bool "Detect stack corruption on calls to schedule()"
795 depends on DEBUG_KERNEL
796 default n
797 help
798 This option checks for a stack overrun on calls to schedule().
799 If the stack end location is found to be over written always panic as
800 the content of the corrupted region can no longer be trusted.
801 This is to ensure no erroneous behaviour occurs which could result in
802 data corruption or a sporadic crash at a later stage once the region
803 is examined. The runtime overhead introduced is minimal.
804
399145f9
AK
805config ARCH_HAS_DEBUG_VM_PGTABLE
806 bool
807 help
808 An architecture should select this when it can successfully
809 build and run DEBUG_VM_PGTABLE.
810
0610c8a8
DH
811config DEBUG_VM
812 bool "Debug VM"
813 depends on DEBUG_KERNEL
814 help
815 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 816 that may impact performance.
0610c8a8
DH
817
818 If unsure, say N.
819
4f115147
DB
820config DEBUG_VM_VMACACHE
821 bool "Debug VMA caching"
822 depends on DEBUG_VM
823 help
824 Enable this to turn on VMA caching debug information. Doing so
825 can cause significant overhead, so only enable it in non-production
826 environments.
827
828 If unsure, say N.
829
0610c8a8
DH
830config DEBUG_VM_RB
831 bool "Debug VM red-black trees"
832 depends on DEBUG_VM
833 help
a663dad6 834 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
835
836 If unsure, say N.
837
95ad9755
KS
838config DEBUG_VM_PGFLAGS
839 bool "Debug page-flags operations"
840 depends on DEBUG_VM
841 help
842 Enables extra validation on page flags operations.
843
844 If unsure, say N.
845
399145f9
AK
846config DEBUG_VM_PGTABLE
847 bool "Debug arch page table for semantics compliance"
848 depends on MMU
849 depends on ARCH_HAS_DEBUG_VM_PGTABLE
850 default y if DEBUG_VM
851 help
852 This option provides a debug method which can be used to test
853 architecture page table helper functions on various platforms in
854 verifying if they comply with expected generic MM semantics. This
855 will help architecture code in making sure that any changes or
856 new additions of these helpers still conform to expected
857 semantics of the generic MM. Platforms will have to opt in for
858 this through ARCH_HAS_DEBUG_VM_PGTABLE.
859
860 If unsure, say N.
861
fa5b6ec9
LA
862config ARCH_HAS_DEBUG_VIRTUAL
863 bool
864
0610c8a8
DH
865config DEBUG_VIRTUAL
866 bool "Debug VM translations"
fa5b6ec9 867 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
868 help
869 Enable some costly sanity checks in virtual to page code. This can
870 catch mistakes with virt_to_page() and friends.
871
872 If unsure, say N.
873
874config DEBUG_NOMMU_REGIONS
875 bool "Debug the global anon/private NOMMU mapping region tree"
876 depends on DEBUG_KERNEL && !MMU
877 help
878 This option causes the global tree of anonymous and private mapping
879 regions to be regularly checked for invalid topology.
880
881config DEBUG_MEMORY_INIT
882 bool "Debug memory initialisation" if EXPERT
883 default !EXPERT
884 help
885 Enable this for additional checks during memory initialisation.
886 The sanity checks verify aspects of the VM such as the memory model
887 and other information provided by the architecture. Verbose
888 information will be printed at KERN_DEBUG loglevel depending
889 on the mminit_loglevel= command-line option.
890
891 If unsure, say Y
892
893config MEMORY_NOTIFIER_ERROR_INJECT
894 tristate "Memory hotplug notifier error injection module"
50f9481e 895 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
0610c8a8
DH
896 help
897 This option provides the ability to inject artificial errors to
898 memory hotplug notifier chain callbacks. It is controlled through
899 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
900
901 If the notifier call chain should be failed with some events
902 notified, write the error code to "actions/<notifier event>/error".
903
904 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
905
906 # cd /sys/kernel/debug/notifier-error-inject/memory
907 # echo -12 > actions/MEM_GOING_OFFLINE/error
908 # echo offline > /sys/devices/system/memory/memoryXXX/state
909 bash: echo: write error: Cannot allocate memory
910
911 To compile this code as a module, choose M here: the module will
912 be called memory-notifier-error-inject.
913
914 If unsure, say N.
915
916config DEBUG_PER_CPU_MAPS
917 bool "Debug access to per_cpu maps"
918 depends on DEBUG_KERNEL
919 depends on SMP
920 help
921 Say Y to verify that the per_cpu map being accessed has
922 been set up. This adds a fair amount of code to kernel memory
923 and decreases performance.
924
925 Say N if unsure.
926
6e799cb6
TG
927config DEBUG_KMAP_LOCAL
928 bool "Debug kmap_local temporary mappings"
929 depends on DEBUG_KERNEL && KMAP_LOCAL
930 help
931 This option enables additional error checking for the kmap_local
932 infrastructure. Disable for production use.
933
0e91a0c6
TG
934config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935 bool
936
937config DEBUG_KMAP_LOCAL_FORCE_MAP
938 bool "Enforce kmap_local temporary mappings"
939 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
940 select KMAP_LOCAL
941 select DEBUG_KMAP_LOCAL
942 help
943 This option enforces temporary mappings through the kmap_local
944 mechanism for non-highmem pages and on non-highmem systems.
945 Disable this for production systems!
946
0610c8a8
DH
947config DEBUG_HIGHMEM
948 bool "Highmem debugging"
949 depends on DEBUG_KERNEL && HIGHMEM
0e91a0c6 950 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
6e799cb6 951 select DEBUG_KMAP_LOCAL
0610c8a8 952 help
b1357c9f
GU
953 This option enables additional error checking for high memory
954 systems. Disable for production systems.
0610c8a8
DH
955
956config HAVE_DEBUG_STACKOVERFLOW
957 bool
958
959config DEBUG_STACKOVERFLOW
960 bool "Check for stack overflows"
961 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 962 help
0610c8a8 963 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 964 and exception stacks (if your architecture uses them). This
0610c8a8
DH
965 option will show detailed messages if free stack space drops
966 below a certain limit.
967
968 These kinds of bugs usually occur when call-chains in the
969 kernel get too deep, especially when interrupts are
970 involved.
971
972 Use this in cases where you see apparently random memory
973 corruption, especially if it appears in 'struct thread_info'
974
975 If in doubt, say "N".
976
0b24becc 977source "lib/Kconfig.kasan"
0ce20dd8 978source "lib/Kconfig.kfence"
0b24becc 979
0610c8a8
DH
980endmenu # "Memory Debugging"
981
a304e1b8
DW
982config DEBUG_SHIRQ
983 bool "Debug shared IRQ handlers"
0244ad00 984 depends on DEBUG_KERNEL
a304e1b8 985 help
0a2fae2a
WS
986 Enable this to generate a spurious interrupt just before a shared
987 interrupt handler is deregistered (generating one when registering
988 is currently disabled). Drivers need to handle this correctly. Some
989 don't and need to be caught.
a304e1b8 990
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CD
991menu "Debug Oops, Lockups and Hangs"
992
993config PANIC_ON_OOPS
994 bool "Panic on Oops"
995 help
996 Say Y here to enable the kernel to panic when it oopses. This
997 has the same effect as setting oops=panic on the kernel command
998 line.
999
1000 This feature is useful to ensure that the kernel does not do
1001 anything erroneous after an oops which could result in data
1002 corruption or other issues.
1003
1004 Say N if unsure.
1005
1006config PANIC_ON_OOPS_VALUE
1007 int
1008 range 0 1
1009 default 0 if !PANIC_ON_OOPS
1010 default 1 if PANIC_ON_OOPS
1011
1012config PANIC_TIMEOUT
1013 int "panic timeout"
1014 default 0
1015 help
9d5b134f 1016 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
1017 the kernel panics. If n = 0, then we wait forever. A timeout
1018 value n > 0 will wait n seconds before rebooting, while a timeout
1019 value n < 0 will reboot immediately.
92aef8fb 1020
58687acb 1021config LOCKUP_DETECTOR
05a4a952
NP
1022 bool
1023
1024config SOFTLOCKUP_DETECTOR
1025 bool "Detect Soft Lockups"
dea20a3f 1026 depends on DEBUG_KERNEL && !S390
05a4a952 1027 select LOCKUP_DETECTOR
8446f1d3 1028 help
58687acb 1029 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 1030 soft lockups.
58687acb
DZ
1031
1032 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 1033 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
1034 chance to run. The current stack trace is displayed upon
1035 detection and the system will stay locked up.
8446f1d3 1036
5f00ae0d
RD
1037config BOOTPARAM_SOFTLOCKUP_PANIC
1038 bool "Panic (Reboot) On Soft Lockups"
1039 depends on SOFTLOCKUP_DETECTOR
1040 help
1041 Say Y here to enable the kernel to panic on "soft lockups",
1042 which are bugs that cause the kernel to loop in kernel
1043 mode for more than 20 seconds (configurable using the watchdog_thresh
1044 sysctl), without giving other tasks a chance to run.
1045
1046 The panic can be used in combination with panic_timeout,
1047 to cause the system to reboot automatically after a
1048 lockup has been detected. This feature is useful for
1049 high-availability systems that have uptime guarantees and
1050 where a lockup must be resolved ASAP.
1051
1052 Say N if unsure.
1053
1054config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
1055 int
1056 depends on SOFTLOCKUP_DETECTOR
1057 range 0 1
1058 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
1059 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
1060
05a4a952
NP
1061config HARDLOCKUP_DETECTOR_PERF
1062 bool
1063 select SOFTLOCKUP_DETECTOR
1064
7edaeb68
TG
1065#
1066# Enables a timestamp based low pass filter to compensate for perf based
1067# hard lockup detection which runs too fast due to turbo modes.
1068#
1069config HARDLOCKUP_CHECK_TIMESTAMP
1070 bool
1071
05a4a952
NP
1072#
1073# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1074# lockup detector rather than the perf based detector.
1075#
1076config HARDLOCKUP_DETECTOR
1077 bool "Detect Hard Lockups"
1078 depends on DEBUG_KERNEL && !S390
1079 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1080 select LOCKUP_DETECTOR
1081 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
05a4a952
NP
1082 help
1083 Say Y here to enable the kernel to act as a watchdog to detect
1084 hard lockups.
1085
58687acb 1086 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 1087 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
1088 chance to run. The current stack trace is displayed upon detection
1089 and the system will stay locked up.
8446f1d3 1090
fef2c9bc
DZ
1091config BOOTPARAM_HARDLOCKUP_PANIC
1092 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 1093 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1094 help
1095 Say Y here to enable the kernel to panic on "hard lockups",
1096 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1097 mode with interrupts disabled for more than 10 seconds (configurable
1098 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1099
1100 Say N if unsure.
1101
1102config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1103 int
8f1f66ed 1104 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1105 range 0 1
1106 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1107 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1108
e162b39a
MSB
1109config DETECT_HUNG_TASK
1110 bool "Detect Hung Tasks"
1111 depends on DEBUG_KERNEL
05a4a952 1112 default SOFTLOCKUP_DETECTOR
e162b39a 1113 help
0610c8a8
DH
1114 Say Y here to enable the kernel to detect "hung tasks",
1115 which are bugs that cause the task to be stuck in
96b03ab8 1116 uninterruptible "D" state indefinitely.
1da177e4 1117
0610c8a8
DH
1118 When a hung task is detected, the kernel will print the
1119 current stack trace (which you should report), but the
1120 task will stay in uninterruptible state. If lockdep is
1121 enabled then all held locks will also be reported. This
1122 feature has negligible overhead.
871751e2 1123
0610c8a8
DH
1124config DEFAULT_HUNG_TASK_TIMEOUT
1125 int "Default timeout for hung task detection (in seconds)"
1126 depends on DETECT_HUNG_TASK
1127 default 120
f0630fff 1128 help
0610c8a8
DH
1129 This option controls the default timeout (in seconds) used
1130 to determine when a task has become non-responsive and should
1131 be considered hung.
f0630fff 1132
0610c8a8
DH
1133 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1134 sysctl or by writing a value to
1135 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1136
0610c8a8
DH
1137 A timeout of 0 disables the check. The default is two minutes.
1138 Keeping the default should be fine in most cases.
b69ec42b 1139
0610c8a8
DH
1140config BOOTPARAM_HUNG_TASK_PANIC
1141 bool "Panic (Reboot) On Hung Tasks"
1142 depends on DETECT_HUNG_TASK
3bba00d7 1143 help
0610c8a8
DH
1144 Say Y here to enable the kernel to panic on "hung tasks",
1145 which are bugs that cause the kernel to leave a task stuck
1146 in uninterruptible "D" state.
3bba00d7 1147
0610c8a8
DH
1148 The panic can be used in combination with panic_timeout,
1149 to cause the system to reboot automatically after a
1150 hung task has been detected. This feature is useful for
1151 high-availability systems that have uptime guarantees and
1152 where a hung tasks must be resolved ASAP.
bf96d1e3 1153
0610c8a8 1154 Say N if unsure.
bf96d1e3 1155
0610c8a8
DH
1156config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1157 int
1158 depends on DETECT_HUNG_TASK
1159 range 0 1
1160 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1161 default 1 if BOOTPARAM_HUNG_TASK_PANIC
3bba00d7 1162
82607adc
TH
1163config WQ_WATCHDOG
1164 bool "Detect Workqueue Stalls"
1165 depends on DEBUG_KERNEL
1166 help
1167 Say Y here to enable stall detection on workqueues. If a
1168 worker pool doesn't make forward progress on a pending work
1169 item for over a given amount of time, 30s by default, a
1170 warning message is printed along with dump of workqueue
1171 state. This can be configured through kernel parameter
1172 "workqueue.watchdog_thresh" and its sysfs counterpart.
1173
30428ef5
KK
1174config TEST_LOCKUP
1175 tristate "Test module to generate lockups"
63646bc9 1176 depends on m
30428ef5
KK
1177 help
1178 This builds the "test_lockup" module that helps to make sure
1179 that watchdogs and lockup detectors are working properly.
1180
1181 Depending on module parameters it could emulate soft or hard
1182 lockup, "hung task", or locking arbitrary lock for a long time.
1183 Also it could generate series of lockups with cooling-down periods.
1184
1185 If unsure, say N.
1186
92aef8fb
DH
1187endmenu # "Debug lockups and hangs"
1188
ebebdd09 1189menu "Scheduler Debugging"
5800dc3c 1190
0610c8a8
DH
1191config SCHED_DEBUG
1192 bool "Collect scheduler debugging info"
1193 depends on DEBUG_KERNEL && PROC_FS
1194 default y
0822ee4a 1195 help
0610c8a8
DH
1196 If you say Y here, the /proc/sched_debug file will be provided
1197 that can help debug the scheduler. The runtime overhead of this
1198 option is minimal.
0822ee4a 1199
f6db8347
NR
1200config SCHED_INFO
1201 bool
1202 default n
1203
0610c8a8
DH
1204config SCHEDSTATS
1205 bool "Collect scheduler statistics"
1206 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1207 select SCHED_INFO
0610c8a8
DH
1208 help
1209 If you say Y here, additional code will be inserted into the
1210 scheduler and related routines to collect statistics about
1211 scheduler behavior and provide them in /proc/schedstat. These
1212 stats may be useful for both tuning and debugging the scheduler
1213 If you aren't debugging the scheduler or trying to tune a specific
1214 application, you can say N to avoid the very slight overhead
1215 this adds.
0822ee4a 1216
ebebdd09 1217endmenu
0d9e2632 1218
3c17ad19
JS
1219config DEBUG_TIMEKEEPING
1220 bool "Enable extra timekeeping sanity checking"
1221 help
1222 This option will enable additional timekeeping sanity checks
1223 which may be helpful when diagnosing issues where timekeeping
1224 problems are suspected.
1225
1226 This may include checks in the timekeeping hotpaths, so this
1227 option may have a (very small) performance impact to some
1228 workloads.
1229
1230 If unsure, say N.
1231
1da177e4
LT
1232config DEBUG_PREEMPT
1233 bool "Debug preemptible kernel"
9f472869 1234 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1235 default y
1236 help
1237 If you say Y here then the kernel will use a debug variant of the
1238 commonly used smp_processor_id() function and will print warnings
1239 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1240 will detect preemption count underflows.
1241
9eade16b
DH
1242menu "Lock Debugging (spinlocks, mutexes, etc...)"
1243
f07cbebb
WL
1244config LOCK_DEBUGGING_SUPPORT
1245 bool
1246 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1247 default y
1248
19193bca
WL
1249config PROVE_LOCKING
1250 bool "Lock debugging: prove locking correctness"
1251 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1252 select LOCKDEP
1253 select DEBUG_SPINLOCK
bb630f9f 1254 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca 1255 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1256 select DEBUG_RWSEMS
19193bca
WL
1257 select DEBUG_WW_MUTEX_SLOWPATH
1258 select DEBUG_LOCK_ALLOC
8fd8ad5c 1259 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1260 select TRACE_IRQFLAGS
1261 default n
1262 help
1263 This feature enables the kernel to prove that all locking
1264 that occurs in the kernel runtime is mathematically
1265 correct: that under no circumstance could an arbitrary (and
1266 not yet triggered) combination of observed locking
1267 sequences (on an arbitrary number of CPUs, running an
1268 arbitrary number of tasks and interrupt contexts) cause a
1269 deadlock.
1270
1271 In short, this feature enables the kernel to report locking
1272 related deadlocks before they actually occur.
1273
1274 The proof does not depend on how hard and complex a
1275 deadlock scenario would be to trigger: how many
1276 participant CPUs, tasks and irq-contexts would be needed
1277 for it to trigger. The proof also does not depend on
1278 timing: if a race and a resulting deadlock is possible
1279 theoretically (no matter how unlikely the race scenario
1280 is), it will be proven so and will immediately be
1281 reported by the kernel (once the event is observed that
1282 makes the deadlock theoretically possible).
1283
1284 If a deadlock is impossible (i.e. the locking rules, as
1285 observed by the kernel, are mathematically correct), the
1286 kernel reports nothing.
1287
1288 NOTE: this feature can also be enabled for rwlocks, mutexes
1289 and rwsems - in which case all dependencies between these
1290 different locking variants are observed and mapped too, and
1291 the proof of observed correctness is also maintained for an
1292 arbitrary combination of these separate locking variants.
1293
387b1468 1294 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1295
de8f5e4f
PZ
1296config PROVE_RAW_LOCK_NESTING
1297 bool "Enable raw_spinlock - spinlock nesting checks"
1298 depends on PROVE_LOCKING
1299 default n
1300 help
1301 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1302 that the lock nesting rules for PREEMPT_RT enabled kernels are
1303 not violated.
1304
1305 NOTE: There are known nesting problems. So if you enable this
1306 option expect lockdep splats until these problems have been fully
1307 addressed which is work in progress. This config switch allows to
1308 identify and analyze these problems. It will be removed and the
9dbbc3b9 1309 check permanently enabled once the main issues have been fixed.
de8f5e4f
PZ
1310
1311 If unsure, select N.
1312
19193bca
WL
1313config LOCK_STAT
1314 bool "Lock usage statistics"
1315 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1316 select LOCKDEP
1317 select DEBUG_SPINLOCK
bb630f9f 1318 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca
WL
1319 select DEBUG_RT_MUTEXES if RT_MUTEXES
1320 select DEBUG_LOCK_ALLOC
1321 default n
1322 help
1323 This feature enables tracking lock contention points
1324
387b1468 1325 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1326
1327 This also enables lock events required by "perf lock",
1328 subcommand of perf.
1329 If you want to use "perf lock", you also need to turn on
1330 CONFIG_EVENT_TRACING.
1331
1332 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1333 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1334
e7eebaf6
IM
1335config DEBUG_RT_MUTEXES
1336 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1337 depends on DEBUG_KERNEL && RT_MUTEXES
1338 help
1339 This allows rt mutex semantics violations and rt mutex related
1340 deadlocks (lockups) to be detected and reported automatically.
1341
1da177e4 1342config DEBUG_SPINLOCK
4d9f34ad 1343 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1344 depends on DEBUG_KERNEL
e335e3eb 1345 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1346 help
1347 Say Y here and build SMP to catch missing spinlock initialization
1348 and certain other kinds of spinlock errors commonly made. This is
1349 best used in conjunction with the NMI watchdog so that spinlock
1350 deadlocks are also debuggable.
1351
4d9f34ad
IM
1352config DEBUG_MUTEXES
1353 bool "Mutex debugging: basic checks"
bb630f9f 1354 depends on DEBUG_KERNEL && !PREEMPT_RT
4d9f34ad
IM
1355 help
1356 This feature allows mutex semantics violations to be detected and
1357 reported.
1358
23010027
DV
1359config DEBUG_WW_MUTEX_SLOWPATH
1360 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1361 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1362 select DEBUG_LOCK_ALLOC
1363 select DEBUG_SPINLOCK
bb630f9f
TG
1364 select DEBUG_MUTEXES if !PREEMPT_RT
1365 select DEBUG_RT_MUTEXES if PREEMPT_RT
23010027
DV
1366 help
1367 This feature enables slowpath testing for w/w mutex users by
1368 injecting additional -EDEADLK wound/backoff cases. Together with
1369 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1370 will test all possible w/w mutex interface abuse with the
1371 exception of simply not acquiring all the required locks.
4d692373
RC
1372 Note that this feature can introduce significant overhead, so
1373 it really should not be enabled in a production or distro kernel,
1374 even a debug kernel. If you are a driver writer, enable it. If
1375 you are a distro, do not.
23010027 1376
5149cbac
WL
1377config DEBUG_RWSEMS
1378 bool "RW Semaphore debugging: basic checks"
c71fd893 1379 depends on DEBUG_KERNEL
5149cbac 1380 help
c71fd893
WL
1381 This debugging feature allows mismatched rw semaphore locks
1382 and unlocks to be detected and reported.
5149cbac 1383
4d9f34ad
IM
1384config DEBUG_LOCK_ALLOC
1385 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1386 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1387 select DEBUG_SPINLOCK
bb630f9f 1388 select DEBUG_MUTEXES if !PREEMPT_RT
f5694788 1389 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1390 select LOCKDEP
1391 help
1392 This feature will check whether any held lock (spinlock, rwlock,
1393 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1394 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1395 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1396 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1397 held during task exit.
1398
4d9f34ad
IM
1399config LOCKDEP
1400 bool
f07cbebb 1401 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1402 select STACKTRACE
4d9f34ad
IM
1403 select KALLSYMS
1404 select KALLSYMS_ALL
1405
395102db
DJ
1406config LOCKDEP_SMALL
1407 bool
1408
5dc33592
TH
1409config LOCKDEP_BITS
1410 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1411 depends on LOCKDEP && !LOCKDEP_SMALL
1412 range 10 30
1413 default 15
1414 help
1415 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1416
1417config LOCKDEP_CHAINS_BITS
1418 int "Bitsize for MAX_LOCKDEP_CHAINS"
1419 depends on LOCKDEP && !LOCKDEP_SMALL
1420 range 10 30
1421 default 16
1422 help
1423 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1424
1425config LOCKDEP_STACK_TRACE_BITS
1426 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1427 depends on LOCKDEP && !LOCKDEP_SMALL
1428 range 10 30
1429 default 19
1430 help
1431 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1432
1433config LOCKDEP_STACK_TRACE_HASH_BITS
1434 int "Bitsize for STACK_TRACE_HASH_SIZE"
1435 depends on LOCKDEP && !LOCKDEP_SMALL
1436 range 10 30
1437 default 14
1438 help
1439 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1440
1441config LOCKDEP_CIRCULAR_QUEUE_BITS
1442 int "Bitsize for elements in circular_queue struct"
1443 depends on LOCKDEP
1444 range 10 30
1445 default 12
1446 help
1447 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1448
4d9f34ad
IM
1449config DEBUG_LOCKDEP
1450 bool "Lock dependency engine debugging"
517e7aa5 1451 depends on DEBUG_KERNEL && LOCKDEP
997acaf6 1452 select DEBUG_IRQFLAGS
4d9f34ad
IM
1453 help
1454 If you say Y here, the lock dependency engine will do
1455 additional runtime checks to debug itself, at the price
1456 of more runtime overhead.
1457
d902db1e
FW
1458config DEBUG_ATOMIC_SLEEP
1459 bool "Sleep inside atomic section checking"
e8f7c70f 1460 select PREEMPT_COUNT
1da177e4 1461 depends on DEBUG_KERNEL
87a4c375 1462 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1463 help
1464 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1465 noisy if they are called inside atomic sections: when a spinlock is
1466 held, inside an rcu read side critical section, inside preempt disabled
1467 sections, inside an interrupt, etc...
1da177e4 1468
cae2ed9a
IM
1469config DEBUG_LOCKING_API_SELFTESTS
1470 bool "Locking API boot-time self-tests"
1471 depends on DEBUG_KERNEL
1472 help
1473 Say Y here if you want the kernel to run a short self-test during
1474 bootup. The self-test checks whether common types of locking bugs
1475 are detected by debugging mechanisms or not. (if you disable
9dbbc3b9 1476 lock debugging then those bugs won't be detected of course.)
cae2ed9a
IM
1477 The following locking APIs are covered: spinlocks, rwlocks,
1478 mutexes and rwsems.
1479
0af3fe1e
PM
1480config LOCK_TORTURE_TEST
1481 tristate "torture tests for locking"
1482 depends on DEBUG_KERNEL
1483 select TORTURE_TEST
0af3fe1e
PM
1484 help
1485 This option provides a kernel module that runs torture tests
1486 on kernel locking primitives. The kernel module may be built
1487 after the fact on the running kernel to be tested, if desired.
1488
1489 Say Y here if you want kernel locking-primitive torture tests
1490 to be built into the kernel.
1491 Say M if you want these torture tests to build as a module.
1492 Say N if you are unsure.
1493
f2a5fec1
CW
1494config WW_MUTEX_SELFTEST
1495 tristate "Wait/wound mutex selftests"
1496 help
1497 This option provides a kernel module that runs tests on the
1498 on the struct ww_mutex locking API.
1499
1500 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1501 with this test harness.
1502
1503 Say M if you want these self tests to build as a module.
1504 Say N if you are unsure.
1505
e9d338a0
PM
1506config SCF_TORTURE_TEST
1507 tristate "torture tests for smp_call_function*()"
1508 depends on DEBUG_KERNEL
1509 select TORTURE_TEST
1510 help
1511 This option provides a kernel module that runs torture tests
1512 on the smp_call_function() family of primitives. The kernel
1513 module may be built after the fact on the running kernel to
1514 be tested, if desired.
1515
35feb604
PM
1516config CSD_LOCK_WAIT_DEBUG
1517 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1518 depends on DEBUG_KERNEL
1519 depends on 64BIT
1520 default n
1521 help
1522 This option enables debug prints when CPUs are slow to respond
1523 to the smp_call_function*() IPI wrappers. These debug prints
1524 include the IPI handler function currently executing (if any)
1525 and relevant stack traces.
1526
9eade16b 1527endmenu # lock debugging
8637c099 1528
9eade16b 1529config TRACE_IRQFLAGS
ed004953 1530 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1531 bool
5ca43f6c 1532 help
9eade16b
DH
1533 Enables hooks to interrupt enabling and disabling for
1534 either tracing or lock debugging.
5ca43f6c 1535
ed004953 1536config TRACE_IRQFLAGS_NMI
1537 def_bool y
1538 depends on TRACE_IRQFLAGS
1539 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1540
997acaf6
MR
1541config DEBUG_IRQFLAGS
1542 bool "Debug IRQ flag manipulation"
1543 help
1544 Enables checks for potentially unsafe enabling or disabling of
1545 interrupts, such as calling raw_local_irq_restore() when interrupts
1546 are enabled.
1547
8637c099 1548config STACKTRACE
0c38e1fe 1549 bool "Stack backtrace support"
8637c099 1550 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1551 help
1552 This option causes the kernel to create a /proc/pid/stack for
1553 every process, showing its current stack trace.
1554 It is also used by various kernel debugging features that require
1555 stack trace generation.
5ca43f6c 1556
eecabf56
TT
1557config WARN_ALL_UNSEEDED_RANDOM
1558 bool "Warn for all uses of unseeded randomness"
1559 default n
d06bfd19
JD
1560 help
1561 Some parts of the kernel contain bugs relating to their use of
1562 cryptographically secure random numbers before it's actually possible
1563 to generate those numbers securely. This setting ensures that these
1564 flaws don't go unnoticed, by enabling a message, should this ever
1565 occur. This will allow people with obscure setups to know when things
1566 are going wrong, so that they might contact developers about fixing
1567 it.
1568
eecabf56
TT
1569 Unfortunately, on some models of some architectures getting
1570 a fully seeded CRNG is extremely difficult, and so this can
1571 result in dmesg getting spammed for a surprisingly long
1572 time. This is really bad from a security perspective, and
1573 so architecture maintainers really need to do what they can
1574 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1575 However, since users cannot do anything actionable to
eecabf56
TT
1576 address this, by default the kernel will issue only a single
1577 warning for the first use of unseeded randomness.
1578
1579 Say Y here if you want to receive warnings for all uses of
1580 unseeded randomness. This will be of use primarily for
4c5d114e 1581 those developers interested in improving the security of
eecabf56
TT
1582 Linux kernels running on their architecture (or
1583 subarchitecture).
d06bfd19 1584
1da177e4
LT
1585config DEBUG_KOBJECT
1586 bool "kobject debugging"
1587 depends on DEBUG_KERNEL
1588 help
1589 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1590 to the syslog.
1da177e4 1591
c817a67e
RK
1592config DEBUG_KOBJECT_RELEASE
1593 bool "kobject release debugging"
2a999aa0 1594 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1595 help
1596 kobjects are reference counted objects. This means that their
1597 last reference count put is not predictable, and the kobject can
1598 live on past the point at which a driver decides to drop it's
1599 initial reference to the kobject gained on allocation. An
1600 example of this would be a struct device which has just been
1601 unregistered.
1602
1603 However, some buggy drivers assume that after such an operation,
1604 the memory backing the kobject can be immediately freed. This
1605 goes completely against the principles of a refcounted object.
1606
1607 If you say Y here, the kernel will delay the release of kobjects
1608 on the last reference count to improve the visibility of this
1609 kind of kobject release bug.
1610
9b2a60c4
CM
1611config HAVE_DEBUG_BUGVERBOSE
1612 bool
1613
3be5cbcd 1614menu "Debug kernel data structures"
1da177e4 1615
199a9afc
DJ
1616config DEBUG_LIST
1617 bool "Debug linked list manipulation"
4520bcb2 1618 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1619 help
1620 Enable this to turn on extended checks in the linked-list
1621 walking routines.
1622
1623 If unsure, say N.
1624
8e18faea 1625config DEBUG_PLIST
b8cfff68
DS
1626 bool "Debug priority linked list manipulation"
1627 depends on DEBUG_KERNEL
1628 help
1629 Enable this to turn on extended checks in the priority-ordered
1630 linked-list (plist) walking routines. This checks the entire
1631 list multiple times during each manipulation.
1632
1633 If unsure, say N.
1634
d6ec0842
JA
1635config DEBUG_SG
1636 bool "Debug SG table operations"
1637 depends on DEBUG_KERNEL
1638 help
1639 Enable this to turn on checks on scatter-gather tables. This can
1640 help find problems with drivers that do not properly initialize
1641 their sg tables.
1642
1643 If unsure, say N.
1644
1b2439db
AV
1645config DEBUG_NOTIFIERS
1646 bool "Debug notifier call chains"
1647 depends on DEBUG_KERNEL
1648 help
1649 Enable this to turn on sanity checking for notifier call chains.
1650 This is most useful for kernel developers to make sure that
1651 modules properly unregister themselves from notifier chains.
1652 This is a relatively cheap check but if you care about maximum
1653 performance, say N.
1654
3be5cbcd
CD
1655config BUG_ON_DATA_CORRUPTION
1656 bool "Trigger a BUG when data corruption is detected"
1657 select DEBUG_LIST
1658 help
1659 Select this option if the kernel should BUG when it encounters
1660 data corruption in kernel memory structures when they get checked
1661 for validity.
1662
1663 If unsure, say N.
1664
1665endmenu
1666
e0e81739
DH
1667config DEBUG_CREDENTIALS
1668 bool "Debug credential management"
1669 depends on DEBUG_KERNEL
1670 help
1671 Enable this to turn on some debug checking for credential
1672 management. The additional code keeps track of the number of
1673 pointers from task_structs to any given cred struct, and checks to
1674 see that this number never exceeds the usage count of the cred
1675 struct.
1676
1677 Furthermore, if SELinux is enabled, this also checks that the
1678 security pointer in the cred struct is never seen to be invalid.
1679
1680 If unsure, say N.
1681
43a0a2a7 1682source "kernel/rcu/Kconfig.debug"
2f03e3ca 1683
f303fccb
TH
1684config DEBUG_WQ_FORCE_RR_CPU
1685 bool "Force round-robin CPU selection for unbound work items"
1686 depends on DEBUG_KERNEL
1687 default n
1688 help
1689 Workqueue used to implicitly guarantee that work items queued
1690 without explicit CPU specified are put on the local CPU. This
1691 guarantee is no longer true and while local CPU is still
1692 preferred work items may be put on foreign CPUs. Kernel
1693 parameter "workqueue.debug_force_rr_cpu" is added to force
1694 round-robin CPU selection to flush out usages which depend on the
1695 now broken guarantee. This config option enables the debug
1696 feature by default. When enabled, memory and cache locality will
1697 be impacted.
1698
757c989b
TG
1699config CPU_HOTPLUG_STATE_CONTROL
1700 bool "Enable CPU hotplug state control"
1701 depends on DEBUG_KERNEL
1702 depends on HOTPLUG_CPU
1703 default n
1704 help
1705 Allows to write steps between "offline" and "online" to the CPUs
1706 sysfs target file so states can be stepped granular. This is a debug
1707 option for now as the hotplug machinery cannot be stopped and
1708 restarted at arbitrary points yet.
1709
1710 Say N if your are unsure.
1711
09a74952
CD
1712config LATENCYTOP
1713 bool "Latency measuring infrastructure"
1714 depends on DEBUG_KERNEL
1715 depends on STACKTRACE_SUPPORT
1716 depends on PROC_FS
7d37cb2c 1717 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
09a74952
CD
1718 select KALLSYMS
1719 select KALLSYMS_ALL
1720 select STACKTRACE
1721 select SCHEDSTATS
09a74952
CD
1722 help
1723 Enable this option if you want to use the LatencyTOP tool
1724 to find out which userspace is blocking on what kernel operations.
1725
1726source "kernel/trace/Kconfig"
1727
1728config PROVIDE_OHCI1394_DMA_INIT
1729 bool "Remote debugging over FireWire early on boot"
1730 depends on PCI && X86
1731 help
1732 If you want to debug problems which hang or crash the kernel early
1733 on boot and the crashing machine has a FireWire port, you can use
1734 this feature to remotely access the memory of the crashed machine
1735 over FireWire. This employs remote DMA as part of the OHCI1394
1736 specification which is now the standard for FireWire controllers.
1737
1738 With remote DMA, you can monitor the printk buffer remotely using
1739 firescope and access all memory below 4GB using fireproxy from gdb.
1740 Even controlling a kernel debugger is possible using remote DMA.
1741
1742 Usage:
1743
1744 If ohci1394_dma=early is used as boot parameter, it will initialize
1745 all OHCI1394 controllers which are found in the PCI config space.
1746
1747 As all changes to the FireWire bus such as enabling and disabling
1748 devices cause a bus reset and thereby disable remote DMA for all
1749 devices, be sure to have the cable plugged and FireWire enabled on
1750 the debugging host before booting the debug target for debugging.
1751
1752 This code (~1k) is freed after boot. By then, the firewire stack
1753 in charge of the OHCI-1394 controllers should be used instead.
1754
a74e2a22 1755 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1756
045f6d79
CD
1757source "samples/Kconfig"
1758
1759config ARCH_HAS_DEVMEM_IS_ALLOWED
1760 bool
1761
1762config STRICT_DEVMEM
1763 bool "Filter access to /dev/mem"
1764 depends on MMU && DEVMEM
527701ed 1765 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
045f6d79
CD
1766 default y if PPC || X86 || ARM64
1767 help
1768 If this option is disabled, you allow userspace (root) access to all
1769 of memory, including kernel and userspace memory. Accidental
1770 access to this is obviously disastrous, but specific access can
1771 be used by people debugging the kernel. Note that with PAT support
1772 enabled, even in this case there are restrictions on /dev/mem
1773 use due to the cache aliasing requirements.
1774
1775 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1776 file only allows userspace access to PCI space and the BIOS code and
1777 data regions. This is sufficient for dosemu and X and all common
1778 users of /dev/mem.
1779
1780 If in doubt, say Y.
1781
1782config IO_STRICT_DEVMEM
1783 bool "Filter I/O access to /dev/mem"
1784 depends on STRICT_DEVMEM
1785 help
1786 If this option is disabled, you allow userspace (root) access to all
1787 io-memory regardless of whether a driver is actively using that
1788 range. Accidental access to this is obviously disastrous, but
1789 specific access can be used by people debugging kernel drivers.
1790
1791 If this option is switched on, the /dev/mem file only allows
1792 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1793 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1794 if the driver using a given range cannot be disabled.
1795
1796 If in doubt, say Y.
1797
1798menu "$(SRCARCH) Debugging"
1799
1800source "arch/$(SRCARCH)/Kconfig.debug"
1801
1802endmenu
1803
1804menu "Kernel Testing and Coverage"
1805
09a74952
CD
1806source "lib/kunit/Kconfig"
1807
8d438288
AM
1808config NOTIFIER_ERROR_INJECTION
1809 tristate "Notifier error injection"
1810 depends on DEBUG_KERNEL
1811 select DEBUG_FS
1812 help
e41e85cc 1813 This option provides the ability to inject artificial errors to
8d438288
AM
1814 specified notifier chain callbacks. It is useful to test the error
1815 handling of notifier call chain failures.
1816
1817 Say N if unsure.
1818
048b9c35
AM
1819config PM_NOTIFIER_ERROR_INJECT
1820 tristate "PM notifier error injection module"
1821 depends on PM && NOTIFIER_ERROR_INJECTION
1822 default m if PM_DEBUG
1823 help
e41e85cc 1824 This option provides the ability to inject artificial errors to
048b9c35
AM
1825 PM notifier chain callbacks. It is controlled through debugfs
1826 interface /sys/kernel/debug/notifier-error-inject/pm
1827
1828 If the notifier call chain should be failed with some events
1829 notified, write the error code to "actions/<notifier event>/error".
1830
1831 Example: Inject PM suspend error (-12 = -ENOMEM)
1832
1833 # cd /sys/kernel/debug/notifier-error-inject/pm/
1834 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1835 # echo mem > /sys/power/state
1836 bash: echo: write error: Cannot allocate memory
1837
1838 To compile this code as a module, choose M here: the module will
1839 be called pm-notifier-error-inject.
1840
1841 If unsure, say N.
1842
d526e85f
BH
1843config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1844 tristate "OF reconfig notifier error injection module"
1845 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1846 help
e41e85cc 1847 This option provides the ability to inject artificial errors to
d526e85f 1848 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1849 through debugfs interface under
d526e85f 1850 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1851
1852 If the notifier call chain should be failed with some events
1853 notified, write the error code to "actions/<notifier event>/error".
1854
1855 To compile this code as a module, choose M here: the module will
e12a95f4 1856 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1857
1858 If unsure, say N.
1859
02fff96a
NA
1860config NETDEV_NOTIFIER_ERROR_INJECT
1861 tristate "Netdev notifier error injection module"
1862 depends on NET && NOTIFIER_ERROR_INJECTION
1863 help
1864 This option provides the ability to inject artificial errors to
1865 netdevice notifier chain callbacks. It is controlled through debugfs
1866 interface /sys/kernel/debug/notifier-error-inject/netdev
1867
1868 If the notifier call chain should be failed with some events
1869 notified, write the error code to "actions/<notifier event>/error".
1870
1871 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1872
1873 # cd /sys/kernel/debug/notifier-error-inject/netdev
1874 # echo -22 > actions/NETDEV_CHANGEMTU/error
1875 # ip link set eth0 mtu 1024
1876 RTNETLINK answers: Invalid argument
1877
1878 To compile this code as a module, choose M here: the module will
1879 be called netdev-notifier-error-inject.
1880
1881 If unsure, say N.
1882
f1b4bd06
MP
1883config FUNCTION_ERROR_INJECTION
1884 def_bool y
1885 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1886
6ff1cb35 1887config FAULT_INJECTION
1ab8509a
AM
1888 bool "Fault-injection framework"
1889 depends on DEBUG_KERNEL
329409ae
AM
1890 help
1891 Provide fault-injection framework.
1892 For more details, see Documentation/fault-injection/.
6ff1cb35 1893
8a8b6502 1894config FAILSLAB
1ab8509a
AM
1895 bool "Fault-injection capability for kmalloc"
1896 depends on FAULT_INJECTION
773ff60e 1897 depends on SLAB || SLUB
8a8b6502 1898 help
1ab8509a 1899 Provide fault-injection capability for kmalloc.
8a8b6502 1900
933e312e 1901config FAIL_PAGE_ALLOC
29b46fa3 1902 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1903 depends on FAULT_INJECTION
933e312e 1904 help
1ab8509a 1905 Provide fault-injection capability for alloc_pages().
933e312e 1906
2c739ced
AL
1907config FAULT_INJECTION_USERCOPY
1908 bool "Fault injection capability for usercopy functions"
1909 depends on FAULT_INJECTION
1910 help
1911 Provides fault-injection capability to inject failures
1912 in usercopy functions (copy_from_user(), get_user(), ...).
1913
c17bb495 1914config FAIL_MAKE_REQUEST
86327d19 1915 bool "Fault-injection capability for disk IO"
581d4e28 1916 depends on FAULT_INJECTION && BLOCK
c17bb495 1917 help
1ab8509a 1918 Provide fault-injection capability for disk IO.
c17bb495 1919
581d4e28 1920config FAIL_IO_TIMEOUT
f4d01439 1921 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1922 depends on FAULT_INJECTION && BLOCK
1923 help
1924 Provide fault-injection capability on end IO handling. This
1925 will make the block layer "forget" an interrupt as configured,
1926 thus exercising the error handling.
1927
1928 Only works with drivers that use the generic timeout handling,
9dbbc3b9 1929 for others it won't do anything.
581d4e28 1930
ab51fbab
DB
1931config FAIL_FUTEX
1932 bool "Fault-injection capability for futexes"
1933 select DEBUG_FS
1934 depends on FAULT_INJECTION && FUTEX
1935 help
1936 Provide fault-injection capability for futexes.
1937
f1b4bd06
MP
1938config FAULT_INJECTION_DEBUG_FS
1939 bool "Debugfs entries for fault-injection capabilities"
1940 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1941 help
1942 Enable configuration of fault-injection capabilities via debugfs.
1943
4b1a29a7
MH
1944config FAIL_FUNCTION
1945 bool "Fault-injection capability for functions"
1946 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1947 help
1948 Provide function-based fault-injection capability.
1949 This will allow you to override a specific function with a return
1950 with given return value. As a result, function caller will see
1951 an error value and have to handle it. This is useful to test the
1952 error handling in various subsystems.
1953
f1b4bd06
MP
1954config FAIL_MMC_REQUEST
1955 bool "Fault-injection capability for MMC IO"
1956 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1957 help
f1b4bd06
MP
1958 Provide fault-injection capability for MMC IO.
1959 This will make the mmc core return data errors. This is
1960 useful to test the error handling in the mmc block device
1961 and to test how the mmc host driver handles retries from
1962 the block device.
1df49008 1963
c782af25
CL
1964config FAIL_SUNRPC
1965 bool "Fault-injection capability for SunRPC"
1966 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
1967 help
1968 Provide fault-injection capability for SunRPC and
1969 its consumers.
1970
1df49008
AM
1971config FAULT_INJECTION_STACKTRACE_FILTER
1972 bool "stacktrace filter for fault-injection capabilities"
1973 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 1974 depends on !X86_64
1df49008 1975 select STACKTRACE
7d37cb2c 1976 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1df49008
AM
1977 help
1978 Provide stacktrace filter for fault-injection capabilities
267c4025 1979
09a74952
CD
1980config ARCH_HAS_KCOV
1981 bool
cc3fa840 1982 help
09a74952
CD
1983 An architecture should select this when it can successfully
1984 build and run with CONFIG_KCOV. This typically requires
1985 disabling instrumentation for some early boot code.
cc3fa840 1986
09a74952
CD
1987config CC_HAS_SANCOV_TRACE_PC
1988 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 1989
cc3fa840 1990
09a74952
CD
1991config KCOV
1992 bool "Code coverage for fuzzing"
1993 depends on ARCH_HAS_KCOV
1994 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
bece04b5
ME
1995 depends on !ARCH_WANTS_NO_INSTR || STACK_VALIDATION || \
1996 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
09a74952
CD
1997 select DEBUG_FS
1998 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1999 help
2000 KCOV exposes kernel code coverage information in a form suitable
2001 for coverage-guided fuzzing (randomized testing).
cc3fa840 2002
09a74952
CD
2003 If RANDOMIZE_BASE is enabled, PC values will not be stable across
2004 different machines and across reboots. If you need stable PC values,
2005 disable RANDOMIZE_BASE.
cc3fa840 2006
09a74952 2007 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 2008
09a74952
CD
2009config KCOV_ENABLE_COMPARISONS
2010 bool "Enable comparison operands collection by KCOV"
2011 depends on KCOV
2012 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2013 help
2014 KCOV also exposes operands of every comparison in the instrumented
2015 code along with operand sizes and PCs of the comparison instructions.
2016 These operands can be used by fuzzing engines to improve the quality
2017 of fuzzing coverage.
cc3fa840 2018
09a74952
CD
2019config KCOV_INSTRUMENT_ALL
2020 bool "Instrument all code by default"
2021 depends on KCOV
2022 default y
2023 help
2024 If you are doing generic system call fuzzing (like e.g. syzkaller),
2025 then you will want to instrument the whole kernel and you should
2026 say y here. If you are doing more targeted fuzzing (like e.g.
2027 filesystem fuzzing with AFL) then you will want to enable coverage
2028 for more specific subsets of files, and should say n here.
84bc809e 2029
5ff3b30a
AK
2030config KCOV_IRQ_AREA_SIZE
2031 hex "Size of interrupt coverage collection area in words"
2032 depends on KCOV
2033 default 0x40000
2034 help
2035 KCOV uses preallocated per-cpu areas to collect coverage from
2036 soft interrupts. This specifies the size of those areas in the
2037 number of unsigned long words.
2038
d3deafaa
VL
2039menuconfig RUNTIME_TESTING_MENU
2040 bool "Runtime Testing"
908009e8 2041 def_bool y
d3deafaa
VL
2042
2043if RUNTIME_TESTING_MENU
881c5149
DH
2044
2045config LKDTM
2046 tristate "Linux Kernel Dump Test Tool Module"
2047 depends on DEBUG_FS
881c5149
DH
2048 help
2049 This module enables testing of the different dumping mechanisms by
2050 inducing system failures at predefined crash points.
2051 If you don't need it: say N
2052 Choose M here to compile this code as a module. The module will be
2053 called lkdtm.
2054
2055 Documentation on how to use the module can be found in
10ffebbe 2056 Documentation/fault-injection/provoke-crashes.rst
881c5149
DH
2057
2058config TEST_LIST_SORT
ebd09577
DL
2059 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2060 depends on KUNIT
2061 default KUNIT_ALL_TESTS
881c5149
DH
2062 help
2063 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
2064 executed only once during system boot (so affects only boot time),
2065 or at module load time.
881c5149
DH
2066
2067 If unsure, say N.
2068
6e24628d
IR
2069config TEST_MIN_HEAP
2070 tristate "Min heap test"
2071 depends on DEBUG_KERNEL || m
2072 help
2073 Enable this to turn on min heap function tests. This test is
2074 executed only once during system boot (so affects only boot time),
2075 or at module load time.
2076
2077 If unsure, say N.
2078
c5adae95 2079config TEST_SORT
36f33b56
DL
2080 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2081 depends on KUNIT
2082 default KUNIT_ALL_TESTS
c5adae95 2083 help
5c4e6798
GU
2084 This option enables the self-test function of 'sort()' at boot,
2085 or at module load time.
c5adae95
KF
2086
2087 If unsure, say N.
2088
5086ea4b
MR
2089config TEST_DIV64
2090 tristate "64bit/32bit division and modulo test"
2091 depends on DEBUG_KERNEL || m
2092 help
2093 Enable this to turn on 'do_div()' function test. This test is
2094 executed only once during system boot (so affects only boot time),
2095 or at module load time.
2096
2097 If unsure, say N.
2098
881c5149 2099config KPROBES_SANITY_TEST
e44e81c5 2100 tristate "Kprobes sanity tests"
881c5149
DH
2101 depends on DEBUG_KERNEL
2102 depends on KPROBES
e44e81c5 2103 depends on KUNIT
881c5149
DH
2104 help
2105 This option provides for testing basic kprobes functionality on
5a6cf77f 2106 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
2107 verified for functionality.
2108
2109 Say N if you are unsure.
2110
2111config BACKTRACE_SELF_TEST
2112 tristate "Self test for the backtrace code"
2113 depends on DEBUG_KERNEL
881c5149
DH
2114 help
2115 This option provides a kernel module that can be used to test
2116 the kernel stack backtrace code. This option is not useful
2117 for distributions or general kernels, but only for kernel
2118 developers working on architecture code.
2119
2120 Note that if you want to also test saved backtraces, you will
2121 have to enable STACKTRACE as well.
2122
2123 Say N if you are unsure.
2124
914a7b50
ED
2125config TEST_REF_TRACKER
2126 tristate "Self test for reference tracker"
2127 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2128 select REF_TRACKER
2129 help
2130 This option provides a kernel module performing tests
2131 using reference tracker infrastructure.
2132
2133 Say N if you are unsure.
2134
910a742d
ML
2135config RBTREE_TEST
2136 tristate "Red-Black tree test"
7c993e11 2137 depends on DEBUG_KERNEL
910a742d
ML
2138 help
2139 A benchmark measuring the performance of the rbtree library.
2140 Also includes rbtree invariant checks.
2141
4b4f3acc
FB
2142config REED_SOLOMON_TEST
2143 tristate "Reed-Solomon library test"
2144 depends on DEBUG_KERNEL || m
2145 select REED_SOLOMON
2146 select REED_SOLOMON_ENC16
2147 select REED_SOLOMON_DEC16
2148 help
2149 This option enables the self-test function of rslib at boot,
2150 or at module load time.
2151
2152 If unsure, say N.
2153
fff3fd8a
ML
2154config INTERVAL_TREE_TEST
2155 tristate "Interval tree test"
0f789b67 2156 depends on DEBUG_KERNEL
a88cc108 2157 select INTERVAL_TREE
fff3fd8a
ML
2158 help
2159 A benchmark measuring the performance of the interval tree library
2160
623fd807
GT
2161config PERCPU_TEST
2162 tristate "Per cpu operations test"
2163 depends on m && DEBUG_KERNEL
2164 help
2165 Enable this option to build test module which validates per-cpu
2166 operations.
2167
2168 If unsure, say N.
2169
881c5149 2170config ATOMIC64_SELFTEST
55ded955 2171 tristate "Perform an atomic64_t self-test"
881c5149 2172 help
55ded955
GU
2173 Enable this option to test the atomic64_t functions at boot or
2174 at module load time.
881c5149
DH
2175
2176 If unsure, say N.
2177
2178config ASYNC_RAID6_TEST
2179 tristate "Self test for hardware accelerated raid6 recovery"
2180 depends on ASYNC_RAID6_RECOV
2181 select ASYNC_MEMCPY
a7f7f624 2182 help
881c5149
DH
2183 This is a one-shot self test that permutes through the
2184 recovery of all the possible two disk failure scenarios for a
2185 N-disk array. Recovery is performed with the asynchronous
2186 raid6 recovery routines, and will optionally use an offload
2187 engine if one is available.
2188
2189 If unsure, say N.
2190
64d1d77a
AS
2191config TEST_HEXDUMP
2192 tristate "Test functions located in the hexdump module at runtime"
2193
b2ff70a0
MC
2194config STRING_SELFTEST
2195 tristate "Test string functions at runtime"
2196
881c5149
DH
2197config TEST_STRING_HELPERS
2198 tristate "Test functions located in the string_helpers module at runtime"
2199
0b0600c8
TH
2200config TEST_STRSCPY
2201 tristate "Test strscpy*() family of functions at runtime"
2202
881c5149
DH
2203config TEST_KSTRTOX
2204 tristate "Test kstrto*() family of functions at runtime"
2205
707cc728
RV
2206config TEST_PRINTF
2207 tristate "Test printf() family of functions at runtime"
2208
50f530e1
RF
2209config TEST_SCANF
2210 tristate "Test scanf() family of functions at runtime"
2211
5fd003f5
DD
2212config TEST_BITMAP
2213 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2214 help
2215 Enable this option to test the bitmap functions at boot.
2216
2217 If unsure, say N.
2218
cfaff0e5
AS
2219config TEST_UUID
2220 tristate "Test functions located in the uuid module at runtime"
2221
ad3d6c72
MW
2222config TEST_XARRAY
2223 tristate "Test the XArray code at runtime"
2224
455a35a6
RV
2225config TEST_OVERFLOW
2226 tristate "Test check_*_overflow() functions at runtime"
2227
7e1e7763 2228config TEST_RHASHTABLE
9d6dbe1b 2229 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2230 help
2231 Enable this option to test the rhashtable functions at boot.
2232
2233 If unsure, say N.
2234
88168bf3
IB
2235config TEST_SIPHASH
2236 tristate "Perform selftest on siphash functions"
468a9428 2237 help
88168bf3
IB
2238 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2239 functions on boot (or module load).
468a9428
GS
2240
2241 This is intended to help people writing architecture-specific
2242 optimized versions. If unsure, say N.
2243
8ab8ba38
MW
2244config TEST_IDA
2245 tristate "Perform selftest on IDA functions"
2246
44091d29
JP
2247config TEST_PARMAN
2248 tristate "Perform selftest on priority array manager"
44091d29
JP
2249 depends on PARMAN
2250 help
2251 Enable this option to test priority array manager on boot
2252 (or module load).
2253
2254 If unsure, say N.
2255
6aed82de
DL
2256config TEST_IRQ_TIMINGS
2257 bool "IRQ timings selftest"
2258 depends on IRQ_TIMINGS
2259 help
2260 Enable this option to test the irq timings code on boot.
2261
2262 If unsure, say N.
2263
8a6f0b47 2264config TEST_LKM
93e9ef83 2265 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2266 depends on m
2267 help
2268 This builds the "test_module" module that emits "Hello, world"
2269 on printk when loaded. It is designed to be used for basic
2270 evaluation of the module loading subsystem (for example when
2271 validating module verification). It lacks any extra dependencies,
2272 and will not normally be loaded by the system unless explicitly
2273 requested by name.
2274
2275 If unsure, say N.
2276
c348c163 2277config TEST_BITOPS
6af132f3 2278 tristate "Test module for compilation of bitops operations"
c348c163
JB
2279 depends on m
2280 help
2281 This builds the "test_bitops" module that is much like the
2282 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2283 set/clear_bit macros and get_count_order/long to make sure there are
2284 no compiler warnings from C=1 sparse checker or -Wextra
2285 compilations. It has no dependencies and doesn't run or load unless
2286 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2287
2288 If unsure, say N.
2289
3f21a6b7
URS
2290config TEST_VMALLOC
2291 tristate "Test module for stress/performance analysis of vmalloc allocator"
2292 default n
2293 depends on MMU
2294 depends on m
2295 help
2296 This builds the "test_vmalloc" module that should be used for
2297 stress and performance analysis. So, any new change for vmalloc
2298 subsystem can be evaluated from performance and stability point
2299 of view.
2300
2301 If unsure, say N.
2302
3e2a4c18
KC
2303config TEST_USER_COPY
2304 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2305 depends on m
2306 help
2307 This builds the "test_user_copy" module that runs sanity checks
2308 on the copy_to/from_user infrastructure, making sure basic
2309 user/kernel boundary testing is working. If it fails to load,
2310 a regression has been detected in the user/kernel memory boundary
2311 protections.
2312
2313 If unsure, say N.
2314
64a8946b
AS
2315config TEST_BPF
2316 tristate "Test BPF filter functionality"
98920ba6 2317 depends on m && NET
64a8946b
AS
2318 help
2319 This builds the "test_bpf" module that runs various test vectors
2320 against the BPF interpreter or BPF JIT compiler depending on the
2321 current setting. This is in particular useful for BPF JIT compiler
2322 development, but also to run regression tests against changes in
3c731eba
AS
2323 the interpreter code. It also enables test stubs for eBPF maps and
2324 verifier used by user space verifier testsuite.
64a8946b
AS
2325
2326 If unsure, say N.
2327
509e56b3
MB
2328config TEST_BLACKHOLE_DEV
2329 tristate "Test blackhole netdev functionality"
2330 depends on m && NET
2331 help
2332 This builds the "test_blackhole_dev" module that validates the
2333 data path through this blackhole netdev.
2334
2335 If unsure, say N.
2336
dceeb3e7 2337config FIND_BIT_BENCHMARK
4441fca0 2338 tristate "Test find_bit functions"
4441fca0
YN
2339 help
2340 This builds the "test_find_bit" module that measure find_*_bit()
2341 functions performance.
2342
2343 If unsure, say N.
2344
0a8adf58
KC
2345config TEST_FIRMWARE
2346 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2347 depends on FW_LOADER
2348 help
2349 This builds the "test_firmware" module that creates a userspace
2350 interface for testing firmware loading. This can be used to
2351 control the triggering of firmware loading without needing an
2352 actual firmware-using device. The contents can be rechecked by
2353 userspace.
2354
2355 If unsure, say N.
2356
9308f2f9
LR
2357config TEST_SYSCTL
2358 tristate "sysctl test driver"
9308f2f9
LR
2359 depends on PROC_SYSCTL
2360 help
2361 This builds the "test_sysctl" module. This driver enables to test the
2362 proc sysctl interfaces available to drivers safely without affecting
2363 production knobs which might alter system functionality.
2364
2365 If unsure, say N.
2366
d2585f51
VMI
2367config BITFIELD_KUNIT
2368 tristate "KUnit test bitfield functions at runtime"
2369 depends on KUNIT
2370 help
2371 Enable this option to test the bitfield functions at boot.
2372
2373 KUnit tests run during boot and output the results to the debug log
2374 in TAP format (http://testanything.org/). Only useful for kernel devs
2375 running the KUnit test harness, and not intended for inclusion into a
2376 production build.
2377
2378 For more information on KUnit and unit tests in general please refer
2379 to the KUnit documentation in Documentation/dev-tools/kunit/.
2380
2381 If unsure, say N.
2382
0acc968f
IB
2383config HASH_KUNIT_TEST
2384 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2385 depends on KUNIT
2386 default KUNIT_ALL_TESTS
2387 help
2388 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2389 integer (<linux/hash.h>) hash functions on boot.
2390
2391 KUnit tests run during boot and output the results to the debug log
2392 in TAP format (https://testanything.org/). Only useful for kernel devs
2393 running the KUnit test harness, and not intended for inclusion into a
2394 production build.
2395
2396 For more information on KUnit and unit tests in general please refer
2397 to the KUnit documentation in Documentation/dev-tools/kunit/.
2398
2399 This is intended to help people writing architecture-specific
2400 optimized versions. If unsure, say N.
2401
5df38ca6
AS
2402config RESOURCE_KUNIT_TEST
2403 tristate "KUnit test for resource API"
2404 depends on KUNIT
2405 help
2406 This builds the resource API unit test.
2407 Tests the logic of API provided by resource.c and ioport.h.
2408 For more information on KUnit and unit tests in general please refer
2409 to the KUnit documentation in Documentation/dev-tools/kunit/.
2410
2411 If unsure, say N.
2412
2cb80dbb 2413config SYSCTL_KUNIT_TEST
5f215aab 2414 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2415 depends on KUNIT
5f215aab 2416 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2417 help
2418 This builds the proc sysctl unit test, which runs on boot.
2419 Tests the API contract and implementation correctness of sysctl.
2420 For more information on KUnit and unit tests in general please refer
2421 to the KUnit documentation in Documentation/dev-tools/kunit/.
2422
2423 If unsure, say N.
2424
ea2dd7c0 2425config LIST_KUNIT_TEST
5f215aab 2426 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2427 depends on KUNIT
5f215aab 2428 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2429 help
2430 This builds the linked list KUnit test suite.
2431 It tests that the API and basic functionality of the list_head type
2432 and associated macros.
2433
2434 KUnit tests run during boot and output the results to the debug log
d89775fc 2435 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2436 running the KUnit test harness, and not intended for inclusion into a
2437 production build.
2438
2439 For more information on KUnit and unit tests in general please refer
2440 to the KUnit documentation in Documentation/dev-tools/kunit/.
2441
2442 If unsure, say N.
2443
33d599f0
MV
2444config LINEAR_RANGES_TEST
2445 tristate "KUnit test for linear_ranges"
2446 depends on KUNIT
2447 select LINEAR_RANGES
2448 help
2449 This builds the linear_ranges unit test, which runs on boot.
2450 Tests the linear_ranges logic correctness.
2451 For more information on KUnit and unit tests in general please refer
7546861a
AS
2452 to the KUnit documentation in Documentation/dev-tools/kunit/.
2453
2454 If unsure, say N.
2455
2456config CMDLINE_KUNIT_TEST
2457 tristate "KUnit test for cmdline API"
2458 depends on KUNIT
2459 help
2460 This builds the cmdline API unit test.
2461 Tests the logic of API provided by cmdline.c.
2462 For more information on KUnit and unit tests in general please refer
33d599f0
MV
2463 to the KUnit documentation in Documentation/dev-tools/kunit/.
2464
2465 If unsure, say N.
2466
6d511020
RF
2467config BITS_TEST
2468 tristate "KUnit test for bits.h"
2469 depends on KUNIT
2470 help
2471 This builds the bits unit test.
2472 Tests the logic of macros defined in bits.h.
2473 For more information on KUnit and unit tests in general please refer
2474 to the KUnit documentation in Documentation/dev-tools/kunit/.
2475
2476 If unsure, say N.
2477
1f9f78b1
OG
2478config SLUB_KUNIT_TEST
2479 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2480 depends on SLUB_DEBUG && KUNIT
2481 default KUNIT_ALL_TESTS
2482 help
2483 This builds SLUB allocator unit test.
2484 Tests SLUB cache debugging functionality.
2485 For more information on KUnit and unit tests in general please refer
2486 to the KUnit documentation in Documentation/dev-tools/kunit/.
2487
2488 If unsure, say N.
2489
b6c75c4a
TP
2490config RATIONAL_KUNIT_TEST
2491 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
8ba739ed 2492 depends on KUNIT && RATIONAL
b6c75c4a
TP
2493 default KUNIT_ALL_TESTS
2494 help
2495 This builds the rational math unit test.
2496 For more information on KUnit and unit tests in general please refer
2497 to the KUnit documentation in Documentation/dev-tools/kunit/.
2498
2499 If unsure, say N.
2500
bb95ebbe
KC
2501config MEMCPY_KUNIT_TEST
2502 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2503 depends on KUNIT
2504 default KUNIT_ALL_TESTS
2505 help
2506 Builds unit tests for memcpy(), memmove(), and memset() functions.
2507 For more information on KUnit and unit tests in general please refer
2508 to the KUnit documentation in Documentation/dev-tools/kunit/.
2509
2510 If unsure, say N.
2511
e704f93a
DR
2512config TEST_UDELAY
2513 tristate "udelay test driver"
e704f93a
DR
2514 help
2515 This builds the "udelay_test" module that helps to make sure
2516 that udelay() is working properly.
2517
2518 If unsure, say N.
2519
2bf9e0ab
IM
2520config TEST_STATIC_KEYS
2521 tristate "Test static keys"
579e1acb
JB
2522 depends on m
2523 help
2bf9e0ab 2524 Test the static key interfaces.
579e1acb
JB
2525
2526 If unsure, say N.
2527
d9c6a72d
LR
2528config TEST_KMOD
2529 tristate "kmod stress tester"
d9c6a72d 2530 depends on m
d9c6a72d 2531 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2532 depends on BLOCK
bbd2e05f 2533 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
d9c6a72d
LR
2534 select TEST_LKM
2535 select XFS_FS
2536 select TUN
2537 select BTRFS_FS
2538 help
2539 Test the kernel's module loading mechanism: kmod. kmod implements
2540 support to load modules using the Linux kernel's usermode helper.
2541 This test provides a series of tests against kmod.
2542
2543 Although technically you can either build test_kmod as a module or
2544 into the kernel we disallow building it into the kernel since
2545 it stress tests request_module() and this will very likely cause
2546 some issues by taking over precious threads available from other
2547 module load requests, ultimately this could be fatal.
2548
2549 To run tests run:
2550
2551 tools/testing/selftests/kmod/kmod.sh --help
2552
2553 If unsure, say N.
2554
e4dace36
FF
2555config TEST_DEBUG_VIRTUAL
2556 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2557 depends on DEBUG_VIRTUAL
2558 help
2559 Test the kernel's ability to detect incorrect calls to
2560 virt_to_phys() done against the non-linear part of the
2561 kernel's virtual address map.
2562
2563 If unsure, say N.
2564
ce76d938
AS
2565config TEST_MEMCAT_P
2566 tristate "Test memcat_p() helper function"
2567 help
2568 Test the memcat_p() helper for correctly merging two
2569 pointer arrays together.
2570
2571 If unsure, say N.
2572
a2818ee4
JL
2573config TEST_LIVEPATCH
2574 tristate "Test livepatching"
2575 default n
bae05437 2576 depends on DYNAMIC_DEBUG
a2818ee4
JL
2577 depends on LIVEPATCH
2578 depends on m
2579 help
2580 Test kernel livepatching features for correctness. The tests will
2581 load test modules that will be livepatched in various scenarios.
2582
2583 To run all the livepatching tests:
2584
2585 make -C tools/testing/selftests TARGETS=livepatch run_tests
2586
2587 Alternatively, individual tests may be invoked:
2588
2589 tools/testing/selftests/livepatch/test-callbacks.sh
2590 tools/testing/selftests/livepatch/test-livepatch.sh
2591 tools/testing/selftests/livepatch/test-shadow-vars.sh
2592
2593 If unsure, say N.
2594
0a020d41
JP
2595config TEST_OBJAGG
2596 tristate "Perform selftest on object aggreration manager"
2597 default n
2598 depends on OBJAGG
2599 help
2600 Enable this option to test object aggregation manager on boot
2601 (or module load).
2602
0a020d41 2603
50ceaa95
KC
2604config TEST_STACKINIT
2605 tristate "Test level of stack variable initialization"
2606 help
2607 Test if the kernel is zero-initializing stack variables and
2608 padding. Coverage is controlled by compiler flags,
2609 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2610 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2611
2612 If unsure, say N.
2613
5015a300
AP
2614config TEST_MEMINIT
2615 tristate "Test heap/page initialization"
2616 help
2617 Test if the kernel is zero-initializing heap and page allocations.
2618 This can be useful to test init_on_alloc and init_on_free features.
2619
2620 If unsure, say N.
2621
b2ef9f5a
RC
2622config TEST_HMM
2623 tristate "Test HMM (Heterogeneous Memory Management)"
2624 depends on TRANSPARENT_HUGEPAGE
2625 depends on DEVICE_PRIVATE
2626 select HMM_MIRROR
2627 select MMU_NOTIFIER
2628 help
2629 This is a pseudo device driver solely for testing HMM.
2630 Say M here if you want to build the HMM test module.
2631 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2632
2633 If unsure, say N.
2634
e320d301
MWO
2635config TEST_FREE_PAGES
2636 tristate "Test freeing pages"
2637 help
2638 Test that a memory leak does not occur due to a race between
2639 freeing a block of pages and a speculative page reference.
2640 Loading this module is safe if your kernel has the bug fixed.
2641 If the bug is not fixed, it will leak gigabytes of memory and
2642 probably OOM your system.
2643
4185b3b9
PA
2644config TEST_FPU
2645 tristate "Test floating point operations in kernel space"
2646 depends on X86 && !KCOV_INSTRUMENT_ALL
2647 help
2648 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2649 which will trigger a sequence of floating point operations. This is used
2650 for self-testing floating point control register setting in
2651 kernel_fpu_begin().
2652
2653 If unsure, say N.
2654
1253b9b8
PM
2655config TEST_CLOCKSOURCE_WATCHDOG
2656 tristate "Test clocksource watchdog in kernel space"
2657 depends on CLOCKSOURCE_WATCHDOG
2658 help
2659 Enable this option to create a kernel module that will trigger
2660 a test of the clocksource watchdog. This module may be loaded
2661 via modprobe or insmod in which case it will run upon being
2662 loaded, or it may be built in, in which case it will run
2663 shortly after boot.
2664
2665 If unsure, say N.
2666
d3deafaa 2667endif # RUNTIME_TESTING_MENU
cc3fa840 2668
dce44566
AK
2669config ARCH_USE_MEMTEST
2670 bool
2671 help
2672 An architecture should select this when it uses early_memtest()
2673 during boot process.
2674
cc3fa840
RD
2675config MEMTEST
2676 bool "Memtest"
dce44566 2677 depends on ARCH_USE_MEMTEST
a7f7f624 2678 help
cc3fa840 2679 This option adds a kernel parameter 'memtest', which allows memtest
dce44566 2680 to be set and executed.
cc3fa840
RD
2681 memtest=0, mean disabled; -- default
2682 memtest=1, mean do 1 test pattern;
2683 ...
2684 memtest=17, mean do 17 test patterns.
2685 If you are unsure how to answer this question, answer N.
2686
21266be9 2687
06ec64b8 2688
af9ca6f9
BB
2689config HYPERV_TESTING
2690 bool "Microsoft Hyper-V driver testing"
2691 default n
2692 depends on HYPERV && DEBUG_FS
2693 help
2694 Select this option to enable Hyper-V vmbus testing.
2695
045f6d79
CD
2696endmenu # "Kernel Testing and Coverage"
2697
75442fb0
MCC
2698source "Documentation/Kconfig"
2699
06ec64b8 2700endmenu # Kernel hacking