Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
[linux-2.6-block.git] / lib / Kconfig.debug
CommitLineData
ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
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21config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
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38config STACKTRACE_BUILD_ID
39 bool "Show build ID information in stacktraces"
40 depends on PRINTK
41 help
42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk format '%p[SR]b'.
44
45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is located.
48
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49config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)"
51 range 1 15
52 default "7"
53 help
54 Default loglevel to determine what will be printed on the console.
55
56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well.
59
50f4d9bd 60 Note: This does not affect the log level of un-prefixed printk()
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61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option.
63
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64config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)"
66 range 1 15
67 default "4"
68 help
69 loglevel to use when "quiet" is passed on the kernel commandline.
70
71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74
42a9dc0b 75config MESSAGE_LOGLEVEL_DEFAULT
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76 int "Default message log level (1-7)"
77 range 1 7
78 default "4"
79 help
80 Default log level for printk statements with no specified priority.
81
82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely may want to set it to a lower
84 priority.
85
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86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89
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90config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help
94 This build option allows you to read kernel boot messages
95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the kernel command line,
97 using "boot_delay=N".
98
99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup conditions.
107
108config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support"
110 default n
111 depends on PRINTK
239a5791 112 depends on (DEBUG_FS || PROC_FS)
ceabef7d 113 select DYNAMIC_DEBUG_CORE
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114 help
115
116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by about 2%.
122
123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* options.
127
128 Usage:
129
130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature.
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134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is:
137
138 filename:lineno [module]function flags format
139
140 filename : source file of the debug statement
141 lineno : line number of the debug statement
142 module : module that contains the debug statement
143 function : function that contains the debug statement
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144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the debug statement
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146
147 From a live system:
148
149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154
155 Example usage:
156
157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 <debugfs>/dynamic_debug/control
160
161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 <debugfs>/dynamic_debug/control
164
165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module nfsd +p' >
167 <debugfs>/dynamic_debug/control
168
169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func svc_process +p' >
171 <debugfs>/dynamic_debug/control
172
173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func svc_process -p' >
175 <debugfs>/dynamic_debug/control
176
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177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information.
604ff0dc 179
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180config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic debug support"
182 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS)
184 help
185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where the kernel image size is
189 sensitive for people.
190
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191config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in printf"
193 default y if PRINTK
194 help
195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel logs easier to read.
199
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200config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y
204 help
205 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of memory.
208
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209endmenu # "printk and dmesg options"
210
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211config DEBUG_KERNEL
212 bool "Kernel debugging"
213 help
214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems.
216
217config DEBUG_MISC
218 bool "Miscellaneous debug code"
219 default DEBUG_KERNEL
220 depends on DEBUG_KERNEL
221 help
222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug option but isn't.
224
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225menu "Compile-time checks and compiler options"
226
227config DEBUG_INFO
f9b3cd24 228 bool
6dfc0665 229 help
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230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice below, indicating that debug
232 information will be generated for build targets.
233
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234# Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
235# some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
236config AS_HAS_NON_CONST_LEB128
237 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
238
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239choice
240 prompt "Debug information"
241 depends on DEBUG_KERNEL
242 help
243 Selecting something other than "None" results in a kernel image
244 that will include debugging info resulting in a larger kernel image.
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245 This adds debug symbols to the kernel and modules (gcc -g), and
246 is needed if you intend to use kernel crashdump or binary object
247 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
6dfc0665 248
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249 Choose which version of DWARF debug info to emit. If unsure,
250 select "Toolchain default".
251
252config DEBUG_INFO_NONE
253 bool "Disable debug information"
254 help
255 Do not build the kernel with debugging information, which will
256 result in a faster and smaller build.
257
258config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
259 bool "Rely on the toolchain's implicit default DWARF version"
260 select DEBUG_INFO
0a6de78c 261 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
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262 help
263 The implicit default version of DWARF debug info produced by a
264 toolchain changes over time.
265
266 This can break consumers of the debug info that haven't upgraded to
267 support newer revisions, and prevent testing newer versions, but
268 those should be less common scenarios.
269
270config DEBUG_INFO_DWARF4
271 bool "Generate DWARF Version 4 debuginfo"
272 select DEBUG_INFO
4f001a21 273 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
f9b3cd24 274 help
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275 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
276 if using clang without clang's integrated assembler, and gdb 7.0+.
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277
278 If you have consumers of DWARF debug info that are not ready for
279 newer revisions of DWARF, you may wish to choose this or have your
280 config select this.
281
282config DEBUG_INFO_DWARF5
283 bool "Generate DWARF Version 5 debuginfo"
284 select DEBUG_INFO
0a6de78c 285 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
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286 help
287 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
288 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
289 draft features until 7.0), and gdb 8.0+.
290
291 Changes to the structure of debug info in Version 5 allow for around
292 15-18% savings in resulting image and debug info section sizes as
293 compared to DWARF Version 4. DWARF Version 5 standardizes previous
294 extensions such as accelerators for symbol indexing and the format
295 for fission (.dwo/.dwp) files. Users may not want to select this
296 config if they rely on tooling that has not yet been updated to
297 support DWARF Version 5.
298
299endchoice # "Debug information"
6dfc0665 300
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301if DEBUG_INFO
302
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303config DEBUG_INFO_REDUCED
304 bool "Reduce debugging information"
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305 help
306 If you say Y here gcc is instructed to generate less debugging
307 information for structure types. This means that tools that
308 need full debugging information (like kgdb or systemtap) won't
309 be happy. But if you merely need debugging information to
310 resolve line numbers there is no loss. Advantage is that
311 build directory object sizes shrink dramatically over a full
312 DEBUG_INFO build and compile times are reduced too.
313 Only works with newer gcc versions.
314
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315choice
316 prompt "Compressed Debug information"
317 help
318 Compress the resulting debug info. Results in smaller debug info sections,
319 but requires that consumers are able to decompress the results.
320
321 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
322
323config DEBUG_INFO_COMPRESSED_NONE
324 bool "Don't compress debug information"
325 help
326 Don't compress debug info sections.
327
328config DEBUG_INFO_COMPRESSED_ZLIB
329 bool "Compress debugging information with zlib"
10e68b02 330 depends on $(cc-option,-gz=zlib)
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331 depends on $(ld-option,--compress-debug-sections=zlib)
332 help
333 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
334 5.0+, binutils 2.26+, and zlib.
335
336 Users of dpkg-deb via scripts/package/builddeb may find an increase in
337 size of their debug .deb packages with this config set, due to the
338 debug info being compressed with zlib, then the object files being
339 recompressed with a different compression scheme. But this is still
340 preferable to setting $KDEB_COMPRESS to "none" which would be even
341 larger.
342
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343config DEBUG_INFO_COMPRESSED_ZSTD
344 bool "Compress debugging information with zstd"
345 depends on $(cc-option,-gz=zstd)
346 depends on $(ld-option,--compress-debug-sections=zstd)
347 help
348 Compress the debug information using zstd. This may provide better
349 compression than zlib, for about the same time costs, but requires newer
350 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
351 zstd.
352
353endchoice # "Compressed Debug information"
354
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355config DEBUG_INFO_SPLIT
356 bool "Produce split debuginfo in .dwo files"
9d937444 357 depends on $(cc-option,-gsplit-dwarf)
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358 # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
359 # prior to 12.x:
360 # https://github.com/llvm/llvm-project/issues/56642
361 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
362 depends on !RISCV || GCC_VERSION >= 120000
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363 help
364 Generate debug info into separate .dwo files. This significantly
365 reduces the build directory size for builds with DEBUG_INFO,
366 because it stores the information only once on disk in .dwo
367 files instead of multiple times in object files and executables.
368 In addition the debug information is also compressed.
369
370 Requires recent gcc (4.7+) and recent gdb/binutils.
371 Any tool that packages or reads debug information would need
372 to know about the .dwo files and include them.
373 Incompatible with older versions of ccache.
374
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375config DEBUG_INFO_BTF
376 bool "Generate BTF typeinfo"
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377 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
378 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
d9847eb8 379 depends on BPF_SYSCALL
52deda95 380 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
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381 # pahole uses elfutils, which does not have support for Hexagon relocations
382 depends on !HEXAGON
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383 help
384 Generate deduplicated BTF type information from DWARF debug info.
385 Turning this on expects presence of pahole tool, which will convert
386 DWARF type info into equivalent deduplicated BTF type info.
387
5f9ae91f 388config PAHOLE_HAS_SPLIT_BTF
6323c813 389 def_bool PAHOLE_VERSION >= 119
5f9ae91f 390
7472d5a6 391config PAHOLE_HAS_BTF_TAG
6323c813 392 def_bool PAHOLE_VERSION >= 123
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393 depends on CC_IS_CLANG
394 help
395 Decide whether pahole emits btf_tag attributes (btf_type_tag and
396 btf_decl_tag) or not. Currently only clang compiler implements
397 these attributes, so make the config depend on CC_IS_CLANG.
5f9ae91f 398
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399config PAHOLE_HAS_LANG_EXCLUDE
400 def_bool PAHOLE_VERSION >= 124
401 help
402 Support for the --lang_exclude flag which makes pahole exclude
403 compilation units from the supplied language. Used in Kbuild to
404 omit Rust CUs which are not supported in version 1.24 of pahole,
405 otherwise it would emit malformed kernel and module binaries when
406 using DEBUG_INFO_BTF_MODULES.
407
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408config DEBUG_INFO_BTF_MODULES
409 def_bool y
410 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
411 help
412 Generate compact split BTF type information for kernel modules.
413
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414config MODULE_ALLOW_BTF_MISMATCH
415 bool "Allow loading modules with non-matching BTF type info"
416 depends on DEBUG_INFO_BTF_MODULES
417 help
418 For modules whose split BTF does not match vmlinux, load without
419 BTF rather than refusing to load. The default behavior with
420 module BTF enabled is to reject modules with such mismatches;
421 this option will still load module BTF where possible but ignore
422 it when a mismatch is found.
423
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424config GDB_SCRIPTS
425 bool "Provide GDB scripts for kernel debugging"
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426 help
427 This creates the required links to GDB helper scripts in the
428 build directory. If you load vmlinux into gdb, the helper
429 scripts will be automatically imported by gdb as well, and
430 additional functions are available to analyze a Linux kernel
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431 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
432 for further details.
3ee7b3fa 433
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434endif # DEBUG_INFO
435
35bb5b1e 436config FRAME_WARN
a83e4ca2 437 int "Warn for stack frames larger than"
35bb5b1e 438 range 0 8192
ac66998d 439 default 0 if KMSAN
0e07f663 440 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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441 default 2048 if PARISC
442 default 1536 if (!64BIT && XTENSA)
152fe65f 443 default 1280 if KASAN && !64BIT
8d192bec 444 default 1024 if !64BIT
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445 default 2048 if 64BIT
446 help
921757bc 447 Tell the compiler to warn at build time for stack frames larger than this.
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448 Setting this too low will cause a lot of warnings.
449 Setting it to 0 disables the warning.
35bb5b1e 450
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451config STRIP_ASM_SYMS
452 bool "Strip assembler-generated symbols during link"
453 default n
454 help
455 Strip internal assembler-generated symbols during a link (symbols
456 that look like '.Lxxx') so they don't pollute the output of
457 get_wchan() and suchlike.
458
1873e870 459config READABLE_ASM
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460 bool "Generate readable assembler code"
461 depends on DEBUG_KERNEL
7d73c3e9 462 depends on CC_IS_GCC
bf4735a4 463 help
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464 Disable some compiler optimizations that tend to generate human unreadable
465 assembler output. This may make the kernel slightly slower, but it helps
466 to keep kernel developers who have to stare a lot at assembler listings
467 sane.
bf4735a4 468
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469config HEADERS_INSTALL
470 bool "Install uapi headers to usr/include"
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471 depends on !UML
472 help
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473 This option will install uapi headers (headers exported to user-space)
474 into the usr/include directory for use during the kernel build.
475 This is unneeded for building the kernel itself, but needed for some
476 user-space program samples. It is also needed by some features such
477 as uapi header sanity checks.
478
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479config DEBUG_SECTION_MISMATCH
480 bool "Enable full Section mismatch analysis"
7d73c3e9 481 depends on CC_IS_GCC
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482 help
483 The section mismatch analysis checks if there are illegal
484 references from one section to another section.
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485 During linktime or runtime, some sections are dropped;
486 any use of code/data previously in these sections would
91341d4b 487 most likely result in an oops.
e809ab01 488 In the code, functions and variables are annotated with
0db0628d 489 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 490 which results in the code/data being placed in specific sections.
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491 The section mismatch analysis is always performed after a full
492 kernel build, and enabling this option causes the following
b7dca6dd 493 additional step to occur:
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494 - Add the option -fno-inline-functions-called-once to gcc commands.
495 When inlining a function annotated with __init in a non-init
496 function, we would lose the section information and thus
91341d4b 497 the analysis would not catch the illegal reference.
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498 This option tells gcc to inline less (but it does result in
499 a larger kernel).
91341d4b 500
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501config SECTION_MISMATCH_WARN_ONLY
502 bool "Make section mismatch errors non-fatal"
503 default y
504 help
505 If you say N here, the build process will fail if there are any
506 section mismatch, instead of just throwing warnings.
507
508 If unsure, say Y.
509
cf536e18 510config DEBUG_FORCE_FUNCTION_ALIGN_64B
1bf18da6 511 bool "Force all function address 64B aligned"
3ed8513c 512 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
d49a0626 513 select FUNCTION_ALIGNMENT_64B
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514 help
515 There are cases that a commit from one domain changes the function
516 address alignment of other domains, and cause magic performance
517 bump (regression or improvement). Enable this option will help to
518 verify if the bump is caused by function alignment changes, while
519 it will slightly increase the kernel size and affect icache usage.
520
521 It is mainly for debug and performance tuning use.
522
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523#
524# Select this config option from the architecture Kconfig, if it
525# is preferred to always offer frame pointers as a config
526# option on the architecture (regardless of KERNEL_DEBUG):
527#
528config ARCH_WANT_FRAME_POINTERS
529 bool
f346f4b3 530
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531config FRAME_POINTER
532 bool "Compile the kernel with frame pointers"
a687a533 533 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 534 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 535 help
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536 If you say Y here the resulting kernel image will be slightly
537 larger and slower, but it gives very useful debugging information
538 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 539
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540config OBJTOOL
541 bool
542
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543config STACK_VALIDATION
544 bool "Compile-time stack metadata validation"
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545 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
546 select OBJTOOL
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547 default n
548 help
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549 Validate frame pointer rules at compile-time. This helps ensure that
550 runtime stack traces are more reliable.
ee9f8fce 551
b9ab5ebb 552 For more information, see
d6a21f2d 553 tools/objtool/Documentation/objtool.txt.
b9ab5ebb 554
0f620cef 555config NOINSTR_VALIDATION
6804c1af 556 bool
489e355b 557 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
03f16cd0 558 select OBJTOOL
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559 default y
560
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561config VMLINUX_MAP
562 bool "Generate vmlinux.map file when linking"
563 depends on EXPERT
564 help
565 Selecting this option will pass "-Map=vmlinux.map" to ld
566 when linking vmlinux. That file can be useful for verifying
567 and debugging magic section games, and for seeing which
568 pieces of code get eliminated with
569 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
570
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571config DEBUG_FORCE_WEAK_PER_CPU
572 bool "Force weak per-cpu definitions"
573 depends on DEBUG_KERNEL
8446f1d3 574 help
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575 s390 and alpha require percpu variables in modules to be
576 defined weak to work around addressing range issue which
577 puts the following two restrictions on percpu variable
578 definitions.
8446f1d3 579
6dfc0665
DH
580 1. percpu symbols must be unique whether static or not
581 2. percpu variables can't be defined inside a function
8446f1d3 582
6dfc0665
DH
583 To ensure that generic code follows the above rules, this
584 option forces all percpu variables to be defined as weak.
5f329089 585
6dfc0665 586endmenu # "Compiler options"
8446f1d3 587
6210b640
CD
588menu "Generic Kernel Debugging Instruments"
589
6dfc0665
DH
590config MAGIC_SYSRQ
591 bool "Magic SysRq key"
592 depends on !UML
593 help
594 If you say Y here, you will have some control over the system even
595 if the system crashes for example during kernel debugging (e.g., you
596 will be able to flush the buffer cache to disk, reboot the system
597 immediately or dump some status information). This is accomplished
598 by pressing various keys while holding SysRq (Alt+PrintScreen). It
599 also works on a serial console (on PC hardware at least), if you
600 send a BREAK and then within 5 seconds a command keypress. The
f8998c22
HH
601 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
602 Don't say Y unless you really know what this hack does.
8446f1d3 603
8eaede49
BH
604config MAGIC_SYSRQ_DEFAULT_ENABLE
605 hex "Enable magic SysRq key functions by default"
606 depends on MAGIC_SYSRQ
607 default 0x1
608 help
609 Specifies which SysRq key functions are enabled by default.
610 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 611 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 612
732dbf3a
FF
613config MAGIC_SYSRQ_SERIAL
614 bool "Enable magic SysRq key over serial"
615 depends on MAGIC_SYSRQ
616 default y
617 help
618 Many embedded boards have a disconnected TTL level serial which can
619 generate some garbage that can lead to spurious false sysrq detects.
620 This option allows you to decide whether you want to enable the
621 magic SysRq key.
622
68af4317
DS
623config MAGIC_SYSRQ_SERIAL_SEQUENCE
624 string "Char sequence that enables magic SysRq over serial"
625 depends on MAGIC_SYSRQ_SERIAL
626 default ""
627 help
628 Specifies a sequence of characters that can follow BREAK to enable
629 SysRq on a serial console.
630
d3394b3d
DS
631 If unsure, leave an empty string and the option will not be enabled.
632
ec29a5c1
CD
633config DEBUG_FS
634 bool "Debug Filesystem"
635 help
636 debugfs is a virtual file system that kernel developers use to put
637 debugging files into. Enable this option to be able to read and
638 write to these files.
639
640 For detailed documentation on the debugfs API, see
641 Documentation/filesystems/.
642
643 If unsure, say N.
644
a24c6f7b
PE
645choice
646 prompt "Debugfs default access"
647 depends on DEBUG_FS
648 default DEBUG_FS_ALLOW_ALL
649 help
650 This selects the default access restrictions for debugfs.
651 It can be overridden with kernel command line option
652 debugfs=[on,no-mount,off]. The restrictions apply for API access
653 and filesystem registration.
654
655config DEBUG_FS_ALLOW_ALL
656 bool "Access normal"
657 help
658 No restrictions apply. Both API and filesystem registration
659 is on. This is the normal default operation.
660
661config DEBUG_FS_DISALLOW_MOUNT
662 bool "Do not register debugfs as filesystem"
663 help
664 The API is open but filesystem is not loaded. Clients can still do
665 their work and read with debug tools that do not need
666 debugfs filesystem.
667
668config DEBUG_FS_ALLOW_NONE
669 bool "No access"
670 help
671 Access is off. Clients get -PERM when trying to create nodes in
672 debugfs tree and debugfs is not registered as a filesystem.
673 Client can then back-off or continue without debugfs access.
674
675endchoice
676
6210b640 677source "lib/Kconfig.kgdb"
6210b640 678source "lib/Kconfig.ubsan"
2645d432 679source "lib/Kconfig.kcsan"
6210b640
CD
680
681endmenu
682
4d92b95f
ED
683menu "Networking Debugging"
684
685source "net/Kconfig.debug"
686
687endmenu # "Networking Debugging"
c66d7a27 688
0610c8a8 689menu "Memory Debugging"
fef2c9bc 690
8636a1f9 691source "mm/Kconfig.debug"
fef2c9bc 692
0610c8a8
DH
693config DEBUG_OBJECTS
694 bool "Debug object operations"
695 depends on DEBUG_KERNEL
9c44bc03 696 help
0610c8a8
DH
697 If you say Y here, additional code will be inserted into the
698 kernel to track the life time of various objects and validate
699 the operations on those objects.
9c44bc03 700
0610c8a8
DH
701config DEBUG_OBJECTS_SELFTEST
702 bool "Debug objects selftest"
703 depends on DEBUG_OBJECTS
704 help
705 This enables the selftest of the object debug code.
9c44bc03 706
0610c8a8
DH
707config DEBUG_OBJECTS_FREE
708 bool "Debug objects in freed memory"
709 depends on DEBUG_OBJECTS
710 help
711 This enables checks whether a k/v free operation frees an area
712 which contains an object which has not been deactivated
713 properly. This can make kmalloc/kfree-intensive workloads
714 much slower.
3ac7fe5a 715
c6f3a97f
TG
716config DEBUG_OBJECTS_TIMERS
717 bool "Debug timer objects"
718 depends on DEBUG_OBJECTS
719 help
720 If you say Y here, additional code will be inserted into the
721 timer routines to track the life time of timer objects and
722 validate the timer operations.
723
dc186ad7
TG
724config DEBUG_OBJECTS_WORK
725 bool "Debug work objects"
726 depends on DEBUG_OBJECTS
727 help
728 If you say Y here, additional code will be inserted into the
729 work queue routines to track the life time of work objects and
730 validate the work operations.
731
551d55a9
MD
732config DEBUG_OBJECTS_RCU_HEAD
733 bool "Debug RCU callbacks objects"
fc2ecf7e 734 depends on DEBUG_OBJECTS
551d55a9
MD
735 help
736 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
737
e2852ae8
TH
738config DEBUG_OBJECTS_PERCPU_COUNTER
739 bool "Debug percpu counter objects"
740 depends on DEBUG_OBJECTS
741 help
742 If you say Y here, additional code will be inserted into the
743 percpu counter routines to track the life time of percpu counter
744 objects and validate the percpu counter operations.
745
3ae70205
IM
746config DEBUG_OBJECTS_ENABLE_DEFAULT
747 int "debug_objects bootup default value (0-1)"
68d4b3df
KK
748 range 0 1
749 default "1"
750 depends on DEBUG_OBJECTS
751 help
752 Debug objects boot parameter default value
3ae70205 753
5035ebc6 754config SHRINKER_DEBUG
5035ebc6
RG
755 bool "Enable shrinker debugging support"
756 depends on DEBUG_FS
757 help
758 Say Y to enable the shrinker debugfs interface which provides
759 visibility into the kernel memory shrinkers subsystem.
760 Disable it to avoid an extra memory footprint.
761
0610c8a8
DH
762config DEBUG_STACK_USAGE
763 bool "Stack utilization instrumentation"
cf8e8658 764 depends on DEBUG_KERNEL
0610c8a8
DH
765 help
766 Enables the display of the minimum amount of free stack which each
767 task has ever had available in the sysrq-T and sysrq-P debug output.
bc09d1de
UKK
768 Also emits a message to dmesg when a process exits if that process
769 used more stack space than previously exiting processes.
0610c8a8
DH
770
771 This option will slow down process creation somewhat.
772
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CD
773config SCHED_STACK_END_CHECK
774 bool "Detect stack corruption on calls to schedule()"
775 depends on DEBUG_KERNEL
776 default n
777 help
778 This option checks for a stack overrun on calls to schedule().
779 If the stack end location is found to be over written always panic as
780 the content of the corrupted region can no longer be trusted.
781 This is to ensure no erroneous behaviour occurs which could result in
782 data corruption or a sporadic crash at a later stage once the region
783 is examined. The runtime overhead introduced is minimal.
784
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AK
785config ARCH_HAS_DEBUG_VM_PGTABLE
786 bool
787 help
788 An architecture should select this when it can successfully
789 build and run DEBUG_VM_PGTABLE.
790
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TG
791config DEBUG_VM_IRQSOFF
792 def_bool DEBUG_VM && !PREEMPT_RT
793
0610c8a8
DH
794config DEBUG_VM
795 bool "Debug VM"
796 depends on DEBUG_KERNEL
797 help
798 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 799 that may impact performance.
0610c8a8
DH
800
801 If unsure, say N.
802
2655421a
NP
803config DEBUG_VM_SHOOT_LAZIES
804 bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
805 depends on DEBUG_VM
806 depends on MMU_LAZY_TLB_SHOOTDOWN
807 help
808 Enable additional IPIs that ensure lazy tlb mm references are removed
809 before the mm is freed.
810
811 If unsure, say N.
812
54a611b6
LH
813config DEBUG_VM_MAPLE_TREE
814 bool "Debug VM maple trees"
4f115147 815 depends on DEBUG_VM
54a611b6 816 select DEBUG_MAPLE_TREE
4f115147 817 help
54a611b6 818 Enable VM maple tree debugging information and extra validations.
4f115147
DB
819
820 If unsure, say N.
821
0610c8a8
DH
822config DEBUG_VM_RB
823 bool "Debug VM red-black trees"
824 depends on DEBUG_VM
825 help
a663dad6 826 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
827
828 If unsure, say N.
829
95ad9755
KS
830config DEBUG_VM_PGFLAGS
831 bool "Debug page-flags operations"
832 depends on DEBUG_VM
833 help
834 Enables extra validation on page flags operations.
835
836 If unsure, say N.
837
399145f9
AK
838config DEBUG_VM_PGTABLE
839 bool "Debug arch page table for semantics compliance"
840 depends on MMU
841 depends on ARCH_HAS_DEBUG_VM_PGTABLE
842 default y if DEBUG_VM
843 help
844 This option provides a debug method which can be used to test
845 architecture page table helper functions on various platforms in
846 verifying if they comply with expected generic MM semantics. This
847 will help architecture code in making sure that any changes or
848 new additions of these helpers still conform to expected
849 semantics of the generic MM. Platforms will have to opt in for
850 this through ARCH_HAS_DEBUG_VM_PGTABLE.
851
852 If unsure, say N.
853
fa5b6ec9
LA
854config ARCH_HAS_DEBUG_VIRTUAL
855 bool
856
0610c8a8
DH
857config DEBUG_VIRTUAL
858 bool "Debug VM translations"
fa5b6ec9 859 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
860 help
861 Enable some costly sanity checks in virtual to page code. This can
862 catch mistakes with virt_to_page() and friends.
863
864 If unsure, say N.
865
866config DEBUG_NOMMU_REGIONS
867 bool "Debug the global anon/private NOMMU mapping region tree"
868 depends on DEBUG_KERNEL && !MMU
869 help
870 This option causes the global tree of anonymous and private mapping
871 regions to be regularly checked for invalid topology.
872
873config DEBUG_MEMORY_INIT
874 bool "Debug memory initialisation" if EXPERT
875 default !EXPERT
876 help
877 Enable this for additional checks during memory initialisation.
878 The sanity checks verify aspects of the VM such as the memory model
879 and other information provided by the architecture. Verbose
880 information will be printed at KERN_DEBUG loglevel depending
881 on the mminit_loglevel= command-line option.
882
883 If unsure, say Y
884
885config MEMORY_NOTIFIER_ERROR_INJECT
886 tristate "Memory hotplug notifier error injection module"
50f9481e 887 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
0610c8a8
DH
888 help
889 This option provides the ability to inject artificial errors to
890 memory hotplug notifier chain callbacks. It is controlled through
891 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
892
893 If the notifier call chain should be failed with some events
894 notified, write the error code to "actions/<notifier event>/error".
895
896 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
897
898 # cd /sys/kernel/debug/notifier-error-inject/memory
899 # echo -12 > actions/MEM_GOING_OFFLINE/error
900 # echo offline > /sys/devices/system/memory/memoryXXX/state
901 bash: echo: write error: Cannot allocate memory
902
903 To compile this code as a module, choose M here: the module will
904 be called memory-notifier-error-inject.
905
906 If unsure, say N.
907
908config DEBUG_PER_CPU_MAPS
909 bool "Debug access to per_cpu maps"
910 depends on DEBUG_KERNEL
911 depends on SMP
912 help
913 Say Y to verify that the per_cpu map being accessed has
914 been set up. This adds a fair amount of code to kernel memory
915 and decreases performance.
916
917 Say N if unsure.
918
6e799cb6
TG
919config DEBUG_KMAP_LOCAL
920 bool "Debug kmap_local temporary mappings"
921 depends on DEBUG_KERNEL && KMAP_LOCAL
922 help
923 This option enables additional error checking for the kmap_local
924 infrastructure. Disable for production use.
925
0e91a0c6
TG
926config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
927 bool
928
929config DEBUG_KMAP_LOCAL_FORCE_MAP
930 bool "Enforce kmap_local temporary mappings"
931 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
932 select KMAP_LOCAL
933 select DEBUG_KMAP_LOCAL
934 help
935 This option enforces temporary mappings through the kmap_local
936 mechanism for non-highmem pages and on non-highmem systems.
937 Disable this for production systems!
938
0610c8a8
DH
939config DEBUG_HIGHMEM
940 bool "Highmem debugging"
941 depends on DEBUG_KERNEL && HIGHMEM
0e91a0c6 942 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
6e799cb6 943 select DEBUG_KMAP_LOCAL
0610c8a8 944 help
b1357c9f
GU
945 This option enables additional error checking for high memory
946 systems. Disable for production systems.
0610c8a8
DH
947
948config HAVE_DEBUG_STACKOVERFLOW
949 bool
950
951config DEBUG_STACKOVERFLOW
952 bool "Check for stack overflows"
953 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 954 help
0610c8a8 955 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 956 and exception stacks (if your architecture uses them). This
0610c8a8
DH
957 option will show detailed messages if free stack space drops
958 below a certain limit.
959
960 These kinds of bugs usually occur when call-chains in the
961 kernel get too deep, especially when interrupts are
962 involved.
963
964 Use this in cases where you see apparently random memory
965 corruption, especially if it appears in 'struct thread_info'
966
967 If in doubt, say "N".
968
0b24becc 969source "lib/Kconfig.kasan"
0ce20dd8 970source "lib/Kconfig.kfence"
f80be457 971source "lib/Kconfig.kmsan"
0b24becc 972
0610c8a8
DH
973endmenu # "Memory Debugging"
974
a304e1b8
DW
975config DEBUG_SHIRQ
976 bool "Debug shared IRQ handlers"
0244ad00 977 depends on DEBUG_KERNEL
a304e1b8 978 help
0a2fae2a
WS
979 Enable this to generate a spurious interrupt just before a shared
980 interrupt handler is deregistered (generating one when registering
981 is currently disabled). Drivers need to handle this correctly. Some
982 don't and need to be caught.
a304e1b8 983
f43a289d
CD
984menu "Debug Oops, Lockups and Hangs"
985
986config PANIC_ON_OOPS
987 bool "Panic on Oops"
988 help
989 Say Y here to enable the kernel to panic when it oopses. This
990 has the same effect as setting oops=panic on the kernel command
991 line.
992
993 This feature is useful to ensure that the kernel does not do
994 anything erroneous after an oops which could result in data
995 corruption or other issues.
996
997 Say N if unsure.
998
999config PANIC_ON_OOPS_VALUE
1000 int
1001 range 0 1
1002 default 0 if !PANIC_ON_OOPS
1003 default 1 if PANIC_ON_OOPS
1004
1005config PANIC_TIMEOUT
1006 int "panic timeout"
1007 default 0
1008 help
9d5b134f 1009 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
1010 the kernel panics. If n = 0, then we wait forever. A timeout
1011 value n > 0 will wait n seconds before rebooting, while a timeout
1012 value n < 0 will reboot immediately.
92aef8fb 1013
58687acb 1014config LOCKUP_DETECTOR
05a4a952
NP
1015 bool
1016
1017config SOFTLOCKUP_DETECTOR
1018 bool "Detect Soft Lockups"
dea20a3f 1019 depends on DEBUG_KERNEL && !S390
05a4a952 1020 select LOCKUP_DETECTOR
8446f1d3 1021 help
58687acb 1022 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 1023 soft lockups.
58687acb
DZ
1024
1025 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 1026 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
1027 chance to run. The current stack trace is displayed upon
1028 detection and the system will stay locked up.
8446f1d3 1029
5f00ae0d
RD
1030config BOOTPARAM_SOFTLOCKUP_PANIC
1031 bool "Panic (Reboot) On Soft Lockups"
1032 depends on SOFTLOCKUP_DETECTOR
1033 help
1034 Say Y here to enable the kernel to panic on "soft lockups",
1035 which are bugs that cause the kernel to loop in kernel
1036 mode for more than 20 seconds (configurable using the watchdog_thresh
1037 sysctl), without giving other tasks a chance to run.
1038
1039 The panic can be used in combination with panic_timeout,
1040 to cause the system to reboot automatically after a
1041 lockup has been detected. This feature is useful for
1042 high-availability systems that have uptime guarantees and
1043 where a lockup must be resolved ASAP.
1044
1045 Say N if unsure.
1046
1356d0b9 1047config HAVE_HARDLOCKUP_DETECTOR_BUDDY
05a4a952 1048 bool
1356d0b9
PM
1049 depends on SMP
1050 default y
05a4a952 1051
7edaeb68 1052#
1356d0b9
PM
1053# Global switch whether to build a hardlockup detector at all. It is available
1054# only when the architecture supports at least one implementation. There are
1055# two exceptions. The hardlockup detector is never enabled on:
7edaeb68 1056#
1356d0b9 1057# s390: it reported many false positives there
05a4a952 1058#
1356d0b9
PM
1059# sparc64: has a custom implementation which is not using the common
1060# hardlockup command line options and sysctl interface.
05a4a952
NP
1061#
1062config HARDLOCKUP_DETECTOR
1063 bool "Detect Hard Lockups"
47f4cb43 1064 depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
a5fcc236 1065 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
1356d0b9
PM
1066 imply HARDLOCKUP_DETECTOR_PERF
1067 imply HARDLOCKUP_DETECTOR_BUDDY
7ca8fe94 1068 imply HARDLOCKUP_DETECTOR_ARCH
05a4a952 1069 select LOCKUP_DETECTOR
4917a25f 1070
05a4a952
NP
1071 help
1072 Say Y here to enable the kernel to act as a watchdog to detect
1073 hard lockups.
1074
58687acb 1075 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 1076 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
1077 chance to run. The current stack trace is displayed upon detection
1078 and the system will stay locked up.
8446f1d3 1079
1356d0b9
PM
1080#
1081# Note that arch-specific variants are always preferred.
1082#
4917a25f
PM
1083config HARDLOCKUP_DETECTOR_PREFER_BUDDY
1084 bool "Prefer the buddy CPU hardlockup detector"
1356d0b9
PM
1085 depends on HARDLOCKUP_DETECTOR
1086 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
a8992d8a 1087 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
4917a25f
PM
1088 help
1089 Say Y here to prefer the buddy hardlockup detector over the perf one.
1090
1091 With the buddy detector, each CPU uses its softlockup hrtimer
1092 to check that the next CPU is processing hrtimer interrupts by
1093 verifying that a counter is increasing.
1094
1095 This hardlockup detector is useful on systems that don't have
1096 an arch-specific hardlockup detector or if resources needed
1097 for the hardlockup detector are better used for other things.
05a4a952 1098
1f423c90
DA
1099config HARDLOCKUP_DETECTOR_PERF
1100 bool
1356d0b9
PM
1101 depends on HARDLOCKUP_DETECTOR
1102 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
a5fcc236 1103 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1f423c90
DA
1104 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1105
1106config HARDLOCKUP_DETECTOR_BUDDY
1107 bool
1356d0b9
PM
1108 depends on HARDLOCKUP_DETECTOR
1109 depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
1110 depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
a5fcc236 1111 depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
1f423c90
DA
1112 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1113
7ca8fe94
PM
1114config HARDLOCKUP_DETECTOR_ARCH
1115 bool
1116 depends on HARDLOCKUP_DETECTOR
1117 depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
1118 help
1119 The arch-specific implementation of the hardlockup detector will
1120 be used.
1121
1356d0b9 1122#
4917a25f
PM
1123# Both the "perf" and "buddy" hardlockup detectors count hrtimer
1124# interrupts. This config enables functions managing this common code.
1356d0b9 1125#
4917a25f
PM
1126config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
1127 bool
1128 select SOFTLOCKUP_DETECTOR
1129
7edaeb68
TG
1130#
1131# Enables a timestamp based low pass filter to compensate for perf based
1132# hard lockup detection which runs too fast due to turbo modes.
1133#
1134config HARDLOCKUP_CHECK_TIMESTAMP
1135 bool
1136
fef2c9bc
DZ
1137config BOOTPARAM_HARDLOCKUP_PANIC
1138 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 1139 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1140 help
1141 Say Y here to enable the kernel to panic on "hard lockups",
1142 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1143 mode with interrupts disabled for more than 10 seconds (configurable
1144 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1145
1146 Say N if unsure.
1147
e162b39a
MSB
1148config DETECT_HUNG_TASK
1149 bool "Detect Hung Tasks"
1150 depends on DEBUG_KERNEL
05a4a952 1151 default SOFTLOCKUP_DETECTOR
e162b39a 1152 help
0610c8a8
DH
1153 Say Y here to enable the kernel to detect "hung tasks",
1154 which are bugs that cause the task to be stuck in
96b03ab8 1155 uninterruptible "D" state indefinitely.
1da177e4 1156
0610c8a8
DH
1157 When a hung task is detected, the kernel will print the
1158 current stack trace (which you should report), but the
1159 task will stay in uninterruptible state. If lockdep is
1160 enabled then all held locks will also be reported. This
1161 feature has negligible overhead.
871751e2 1162
0610c8a8
DH
1163config DEFAULT_HUNG_TASK_TIMEOUT
1164 int "Default timeout for hung task detection (in seconds)"
1165 depends on DETECT_HUNG_TASK
1166 default 120
f0630fff 1167 help
0610c8a8
DH
1168 This option controls the default timeout (in seconds) used
1169 to determine when a task has become non-responsive and should
1170 be considered hung.
f0630fff 1171
0610c8a8
DH
1172 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1173 sysctl or by writing a value to
1174 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1175
0610c8a8
DH
1176 A timeout of 0 disables the check. The default is two minutes.
1177 Keeping the default should be fine in most cases.
b69ec42b 1178
0610c8a8
DH
1179config BOOTPARAM_HUNG_TASK_PANIC
1180 bool "Panic (Reboot) On Hung Tasks"
1181 depends on DETECT_HUNG_TASK
3bba00d7 1182 help
0610c8a8
DH
1183 Say Y here to enable the kernel to panic on "hung tasks",
1184 which are bugs that cause the kernel to leave a task stuck
1185 in uninterruptible "D" state.
3bba00d7 1186
0610c8a8
DH
1187 The panic can be used in combination with panic_timeout,
1188 to cause the system to reboot automatically after a
1189 hung task has been detected. This feature is useful for
1190 high-availability systems that have uptime guarantees and
1191 where a hung tasks must be resolved ASAP.
bf96d1e3 1192
0610c8a8 1193 Say N if unsure.
bf96d1e3 1194
82607adc
TH
1195config WQ_WATCHDOG
1196 bool "Detect Workqueue Stalls"
1197 depends on DEBUG_KERNEL
1198 help
1199 Say Y here to enable stall detection on workqueues. If a
1200 worker pool doesn't make forward progress on a pending work
1201 item for over a given amount of time, 30s by default, a
1202 warning message is printed along with dump of workqueue
1203 state. This can be configured through kernel parameter
1204 "workqueue.watchdog_thresh" and its sysfs counterpart.
1205
63638450
TH
1206config WQ_CPU_INTENSIVE_REPORT
1207 bool "Report per-cpu work items which hog CPU for too long"
1208 depends on DEBUG_KERNEL
1209 help
1210 Say Y here to enable reporting of concurrency-managed per-cpu work
1211 items that hog CPUs for longer than
b2ec116a 1212 workqueue.cpu_intensive_thresh_us. Workqueue automatically
63638450
TH
1213 detects and excludes them from concurrency management to prevent
1214 them from stalling other per-cpu work items. Occassional
1215 triggering may not necessarily indicate a problem. Repeated
1216 triggering likely indicates that the work item should be switched
1217 to use an unbound workqueue.
1218
30428ef5
KK
1219config TEST_LOCKUP
1220 tristate "Test module to generate lockups"
63646bc9 1221 depends on m
30428ef5
KK
1222 help
1223 This builds the "test_lockup" module that helps to make sure
1224 that watchdogs and lockup detectors are working properly.
1225
1226 Depending on module parameters it could emulate soft or hard
1227 lockup, "hung task", or locking arbitrary lock for a long time.
1228 Also it could generate series of lockups with cooling-down periods.
1229
1230 If unsure, say N.
1231
92aef8fb
DH
1232endmenu # "Debug lockups and hangs"
1233
ebebdd09 1234menu "Scheduler Debugging"
5800dc3c 1235
0610c8a8
DH
1236config SCHED_DEBUG
1237 bool "Collect scheduler debugging info"
35260cf5 1238 depends on DEBUG_KERNEL && DEBUG_FS
0610c8a8 1239 default y
0822ee4a 1240 help
1e90e35b 1241 If you say Y here, the /sys/kernel/debug/sched file will be provided
0610c8a8
DH
1242 that can help debug the scheduler. The runtime overhead of this
1243 option is minimal.
0822ee4a 1244
f6db8347
NR
1245config SCHED_INFO
1246 bool
1247 default n
1248
0610c8a8
DH
1249config SCHEDSTATS
1250 bool "Collect scheduler statistics"
1251 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1252 select SCHED_INFO
0610c8a8
DH
1253 help
1254 If you say Y here, additional code will be inserted into the
1255 scheduler and related routines to collect statistics about
1256 scheduler behavior and provide them in /proc/schedstat. These
1257 stats may be useful for both tuning and debugging the scheduler
1258 If you aren't debugging the scheduler or trying to tune a specific
1259 application, you can say N to avoid the very slight overhead
1260 this adds.
0822ee4a 1261
ebebdd09 1262endmenu
0d9e2632 1263
3c17ad19
JS
1264config DEBUG_TIMEKEEPING
1265 bool "Enable extra timekeeping sanity checking"
1266 help
1267 This option will enable additional timekeeping sanity checks
1268 which may be helpful when diagnosing issues where timekeeping
1269 problems are suspected.
1270
1271 This may include checks in the timekeeping hotpaths, so this
1272 option may have a (very small) performance impact to some
1273 workloads.
1274
1275 If unsure, say N.
1276
1da177e4
LT
1277config DEBUG_PREEMPT
1278 bool "Debug preemptible kernel"
9f472869 1279 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1280 help
1281 If you say Y here then the kernel will use a debug variant of the
1282 commonly used smp_processor_id() function and will print warnings
1283 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1284 will detect preemption count underflows.
1285
cc600391
HY
1286 This option has potential to introduce high runtime overhead,
1287 depending on workload as it triggers debugging routines for each
1288 this_cpu operation. It should only be used for debugging purposes.
1289
9eade16b
DH
1290menu "Lock Debugging (spinlocks, mutexes, etc...)"
1291
f07cbebb
WL
1292config LOCK_DEBUGGING_SUPPORT
1293 bool
1294 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1295 default y
1296
19193bca
WL
1297config PROVE_LOCKING
1298 bool "Lock debugging: prove locking correctness"
1299 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1300 select LOCKDEP
1301 select DEBUG_SPINLOCK
bb630f9f 1302 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca 1303 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1304 select DEBUG_RWSEMS
19193bca
WL
1305 select DEBUG_WW_MUTEX_SLOWPATH
1306 select DEBUG_LOCK_ALLOC
8fd8ad5c 1307 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1308 select TRACE_IRQFLAGS
1309 default n
1310 help
1311 This feature enables the kernel to prove that all locking
1312 that occurs in the kernel runtime is mathematically
1313 correct: that under no circumstance could an arbitrary (and
1314 not yet triggered) combination of observed locking
1315 sequences (on an arbitrary number of CPUs, running an
1316 arbitrary number of tasks and interrupt contexts) cause a
1317 deadlock.
1318
1319 In short, this feature enables the kernel to report locking
1320 related deadlocks before they actually occur.
1321
1322 The proof does not depend on how hard and complex a
1323 deadlock scenario would be to trigger: how many
1324 participant CPUs, tasks and irq-contexts would be needed
1325 for it to trigger. The proof also does not depend on
1326 timing: if a race and a resulting deadlock is possible
1327 theoretically (no matter how unlikely the race scenario
1328 is), it will be proven so and will immediately be
1329 reported by the kernel (once the event is observed that
1330 makes the deadlock theoretically possible).
1331
1332 If a deadlock is impossible (i.e. the locking rules, as
1333 observed by the kernel, are mathematically correct), the
1334 kernel reports nothing.
1335
1336 NOTE: this feature can also be enabled for rwlocks, mutexes
1337 and rwsems - in which case all dependencies between these
1338 different locking variants are observed and mapped too, and
1339 the proof of observed correctness is also maintained for an
1340 arbitrary combination of these separate locking variants.
1341
387b1468 1342 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1343
de8f5e4f
PZ
1344config PROVE_RAW_LOCK_NESTING
1345 bool "Enable raw_spinlock - spinlock nesting checks"
1346 depends on PROVE_LOCKING
1347 default n
1348 help
1349 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1350 that the lock nesting rules for PREEMPT_RT enabled kernels are
1351 not violated.
1352
1353 NOTE: There are known nesting problems. So if you enable this
1354 option expect lockdep splats until these problems have been fully
1355 addressed which is work in progress. This config switch allows to
1356 identify and analyze these problems. It will be removed and the
9dbbc3b9 1357 check permanently enabled once the main issues have been fixed.
de8f5e4f
PZ
1358
1359 If unsure, select N.
1360
19193bca
WL
1361config LOCK_STAT
1362 bool "Lock usage statistics"
1363 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1364 select LOCKDEP
1365 select DEBUG_SPINLOCK
bb630f9f 1366 select DEBUG_MUTEXES if !PREEMPT_RT
19193bca
WL
1367 select DEBUG_RT_MUTEXES if RT_MUTEXES
1368 select DEBUG_LOCK_ALLOC
1369 default n
1370 help
1371 This feature enables tracking lock contention points
1372
387b1468 1373 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1374
1375 This also enables lock events required by "perf lock",
1376 subcommand of perf.
1377 If you want to use "perf lock", you also need to turn on
1378 CONFIG_EVENT_TRACING.
1379
1380 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1381 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1382
e7eebaf6
IM
1383config DEBUG_RT_MUTEXES
1384 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1385 depends on DEBUG_KERNEL && RT_MUTEXES
1386 help
1387 This allows rt mutex semantics violations and rt mutex related
1388 deadlocks (lockups) to be detected and reported automatically.
1389
1da177e4 1390config DEBUG_SPINLOCK
4d9f34ad 1391 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1392 depends on DEBUG_KERNEL
e335e3eb 1393 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1394 help
1395 Say Y here and build SMP to catch missing spinlock initialization
1396 and certain other kinds of spinlock errors commonly made. This is
1397 best used in conjunction with the NMI watchdog so that spinlock
1398 deadlocks are also debuggable.
1399
4d9f34ad
IM
1400config DEBUG_MUTEXES
1401 bool "Mutex debugging: basic checks"
bb630f9f 1402 depends on DEBUG_KERNEL && !PREEMPT_RT
4d9f34ad
IM
1403 help
1404 This feature allows mutex semantics violations to be detected and
1405 reported.
1406
23010027
DV
1407config DEBUG_WW_MUTEX_SLOWPATH
1408 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1409 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1410 select DEBUG_LOCK_ALLOC
1411 select DEBUG_SPINLOCK
bb630f9f
TG
1412 select DEBUG_MUTEXES if !PREEMPT_RT
1413 select DEBUG_RT_MUTEXES if PREEMPT_RT
23010027
DV
1414 help
1415 This feature enables slowpath testing for w/w mutex users by
1416 injecting additional -EDEADLK wound/backoff cases. Together with
1417 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1418 will test all possible w/w mutex interface abuse with the
1419 exception of simply not acquiring all the required locks.
4d692373
RC
1420 Note that this feature can introduce significant overhead, so
1421 it really should not be enabled in a production or distro kernel,
1422 even a debug kernel. If you are a driver writer, enable it. If
1423 you are a distro, do not.
23010027 1424
5149cbac
WL
1425config DEBUG_RWSEMS
1426 bool "RW Semaphore debugging: basic checks"
c71fd893 1427 depends on DEBUG_KERNEL
5149cbac 1428 help
c71fd893
WL
1429 This debugging feature allows mismatched rw semaphore locks
1430 and unlocks to be detected and reported.
5149cbac 1431
4d9f34ad
IM
1432config DEBUG_LOCK_ALLOC
1433 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1434 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1435 select DEBUG_SPINLOCK
bb630f9f 1436 select DEBUG_MUTEXES if !PREEMPT_RT
f5694788 1437 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1438 select LOCKDEP
1439 help
1440 This feature will check whether any held lock (spinlock, rwlock,
1441 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1442 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1443 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1444 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1445 held during task exit.
1446
4d9f34ad
IM
1447config LOCKDEP
1448 bool
f07cbebb 1449 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1450 select STACKTRACE
4d9f34ad
IM
1451 select KALLSYMS
1452 select KALLSYMS_ALL
1453
395102db
DJ
1454config LOCKDEP_SMALL
1455 bool
1456
5dc33592
TH
1457config LOCKDEP_BITS
1458 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1459 depends on LOCKDEP && !LOCKDEP_SMALL
1460 range 10 30
1461 default 15
1462 help
1463 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1464
1465config LOCKDEP_CHAINS_BITS
1466 int "Bitsize for MAX_LOCKDEP_CHAINS"
1467 depends on LOCKDEP && !LOCKDEP_SMALL
1468 range 10 30
1469 default 16
1470 help
1471 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1472
1473config LOCKDEP_STACK_TRACE_BITS
1474 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1475 depends on LOCKDEP && !LOCKDEP_SMALL
1476 range 10 30
1477 default 19
1478 help
1479 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1480
1481config LOCKDEP_STACK_TRACE_HASH_BITS
1482 int "Bitsize for STACK_TRACE_HASH_SIZE"
1483 depends on LOCKDEP && !LOCKDEP_SMALL
1484 range 10 30
1485 default 14
1486 help
f478b998 1487 Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
5dc33592
TH
1488
1489config LOCKDEP_CIRCULAR_QUEUE_BITS
1490 int "Bitsize for elements in circular_queue struct"
1491 depends on LOCKDEP
1492 range 10 30
1493 default 12
1494 help
1495 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1496
4d9f34ad
IM
1497config DEBUG_LOCKDEP
1498 bool "Lock dependency engine debugging"
517e7aa5 1499 depends on DEBUG_KERNEL && LOCKDEP
997acaf6 1500 select DEBUG_IRQFLAGS
4d9f34ad
IM
1501 help
1502 If you say Y here, the lock dependency engine will do
1503 additional runtime checks to debug itself, at the price
1504 of more runtime overhead.
1505
d902db1e
FW
1506config DEBUG_ATOMIC_SLEEP
1507 bool "Sleep inside atomic section checking"
e8f7c70f 1508 select PREEMPT_COUNT
1da177e4 1509 depends on DEBUG_KERNEL
87a4c375 1510 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1511 help
1512 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1513 noisy if they are called inside atomic sections: when a spinlock is
1514 held, inside an rcu read side critical section, inside preempt disabled
1515 sections, inside an interrupt, etc...
1da177e4 1516
cae2ed9a
IM
1517config DEBUG_LOCKING_API_SELFTESTS
1518 bool "Locking API boot-time self-tests"
1519 depends on DEBUG_KERNEL
1520 help
1521 Say Y here if you want the kernel to run a short self-test during
1522 bootup. The self-test checks whether common types of locking bugs
1523 are detected by debugging mechanisms or not. (if you disable
9dbbc3b9 1524 lock debugging then those bugs won't be detected of course.)
cae2ed9a
IM
1525 The following locking APIs are covered: spinlocks, rwlocks,
1526 mutexes and rwsems.
1527
0af3fe1e
PM
1528config LOCK_TORTURE_TEST
1529 tristate "torture tests for locking"
1530 depends on DEBUG_KERNEL
1531 select TORTURE_TEST
0af3fe1e
PM
1532 help
1533 This option provides a kernel module that runs torture tests
1534 on kernel locking primitives. The kernel module may be built
1535 after the fact on the running kernel to be tested, if desired.
1536
1537 Say Y here if you want kernel locking-primitive torture tests
1538 to be built into the kernel.
1539 Say M if you want these torture tests to build as a module.
1540 Say N if you are unsure.
1541
f2a5fec1
CW
1542config WW_MUTEX_SELFTEST
1543 tristate "Wait/wound mutex selftests"
1544 help
1545 This option provides a kernel module that runs tests on the
1546 on the struct ww_mutex locking API.
1547
1548 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1549 with this test harness.
1550
1551 Say M if you want these self tests to build as a module.
1552 Say N if you are unsure.
1553
e9d338a0
PM
1554config SCF_TORTURE_TEST
1555 tristate "torture tests for smp_call_function*()"
1556 depends on DEBUG_KERNEL
1557 select TORTURE_TEST
1558 help
1559 This option provides a kernel module that runs torture tests
1560 on the smp_call_function() family of primitives. The kernel
1561 module may be built after the fact on the running kernel to
1562 be tested, if desired.
1563
35feb604
PM
1564config CSD_LOCK_WAIT_DEBUG
1565 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1566 depends on DEBUG_KERNEL
1567 depends on 64BIT
1568 default n
1569 help
1570 This option enables debug prints when CPUs are slow to respond
1571 to the smp_call_function*() IPI wrappers. These debug prints
1572 include the IPI handler function currently executing (if any)
1573 and relevant stack traces.
1574
c5219860
PM
1575config CSD_LOCK_WAIT_DEBUG_DEFAULT
1576 bool "Default csd_lock_wait() debugging on at boot time"
1577 depends on CSD_LOCK_WAIT_DEBUG
1578 depends on 64BIT
1579 default n
1580 help
1581 This option causes the csdlock_debug= kernel boot parameter to
1582 default to 1 (basic debugging) instead of 0 (no debugging).
1583
9eade16b 1584endmenu # lock debugging
8637c099 1585
9eade16b 1586config TRACE_IRQFLAGS
ed004953 1587 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1588 bool
5ca43f6c 1589 help
9eade16b
DH
1590 Enables hooks to interrupt enabling and disabling for
1591 either tracing or lock debugging.
5ca43f6c 1592
ed004953 1593config TRACE_IRQFLAGS_NMI
1594 def_bool y
1595 depends on TRACE_IRQFLAGS
1596 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1597
1a3ea611
PM
1598config NMI_CHECK_CPU
1599 bool "Debugging for CPUs failing to respond to backtrace requests"
1600 depends on DEBUG_KERNEL
1601 depends on X86
1602 default n
1603 help
1604 Enables debug prints when a CPU fails to respond to a given
1605 backtrace NMI. These prints provide some reasons why a CPU
1606 might legitimately be failing to respond, for example, if it
1607 is offline of if ignore_nmis is set.
1608
997acaf6
MR
1609config DEBUG_IRQFLAGS
1610 bool "Debug IRQ flag manipulation"
1611 help
1612 Enables checks for potentially unsafe enabling or disabling of
1613 interrupts, such as calling raw_local_irq_restore() when interrupts
1614 are enabled.
1615
8637c099 1616config STACKTRACE
0c38e1fe 1617 bool "Stack backtrace support"
8637c099 1618 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1619 help
1620 This option causes the kernel to create a /proc/pid/stack for
1621 every process, showing its current stack trace.
1622 It is also used by various kernel debugging features that require
1623 stack trace generation.
5ca43f6c 1624
eecabf56
TT
1625config WARN_ALL_UNSEEDED_RANDOM
1626 bool "Warn for all uses of unseeded randomness"
1627 default n
d06bfd19
JD
1628 help
1629 Some parts of the kernel contain bugs relating to their use of
1630 cryptographically secure random numbers before it's actually possible
1631 to generate those numbers securely. This setting ensures that these
1632 flaws don't go unnoticed, by enabling a message, should this ever
1633 occur. This will allow people with obscure setups to know when things
1634 are going wrong, so that they might contact developers about fixing
1635 it.
1636
eecabf56
TT
1637 Unfortunately, on some models of some architectures getting
1638 a fully seeded CRNG is extremely difficult, and so this can
1639 result in dmesg getting spammed for a surprisingly long
1640 time. This is really bad from a security perspective, and
1641 so architecture maintainers really need to do what they can
1642 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1643 However, since users cannot do anything actionable to
cc1e127b 1644 address this, by default this option is disabled.
eecabf56
TT
1645
1646 Say Y here if you want to receive warnings for all uses of
1647 unseeded randomness. This will be of use primarily for
4c5d114e 1648 those developers interested in improving the security of
eecabf56
TT
1649 Linux kernels running on their architecture (or
1650 subarchitecture).
d06bfd19 1651
1da177e4
LT
1652config DEBUG_KOBJECT
1653 bool "kobject debugging"
1654 depends on DEBUG_KERNEL
1655 help
1656 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1657 to the syslog.
1da177e4 1658
c817a67e
RK
1659config DEBUG_KOBJECT_RELEASE
1660 bool "kobject release debugging"
2a999aa0 1661 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1662 help
1663 kobjects are reference counted objects. This means that their
1664 last reference count put is not predictable, and the kobject can
b6c69474 1665 live on past the point at which a driver decides to drop its
c817a67e
RK
1666 initial reference to the kobject gained on allocation. An
1667 example of this would be a struct device which has just been
1668 unregistered.
1669
1670 However, some buggy drivers assume that after such an operation,
1671 the memory backing the kobject can be immediately freed. This
1672 goes completely against the principles of a refcounted object.
1673
1674 If you say Y here, the kernel will delay the release of kobjects
1675 on the last reference count to improve the visibility of this
1676 kind of kobject release bug.
1677
9b2a60c4
CM
1678config HAVE_DEBUG_BUGVERBOSE
1679 bool
1680
3be5cbcd 1681menu "Debug kernel data structures"
1da177e4 1682
199a9afc
DJ
1683config DEBUG_LIST
1684 bool "Debug linked list manipulation"
aa9f10d5 1685 depends on DEBUG_KERNEL
aebc7b0d 1686 select LIST_HARDENED
199a9afc 1687 help
aebc7b0d
ME
1688 Enable this to turn on extended checks in the linked-list walking
1689 routines.
1690
1691 This option trades better quality error reports for performance, and
1692 is more suitable for kernel debugging. If you care about performance,
1693 you should only enable CONFIG_LIST_HARDENED instead.
199a9afc
DJ
1694
1695 If unsure, say N.
1696
8e18faea 1697config DEBUG_PLIST
b8cfff68
DS
1698 bool "Debug priority linked list manipulation"
1699 depends on DEBUG_KERNEL
1700 help
1701 Enable this to turn on extended checks in the priority-ordered
1702 linked-list (plist) walking routines. This checks the entire
1703 list multiple times during each manipulation.
1704
1705 If unsure, say N.
1706
d6ec0842
JA
1707config DEBUG_SG
1708 bool "Debug SG table operations"
1709 depends on DEBUG_KERNEL
1710 help
1711 Enable this to turn on checks on scatter-gather tables. This can
1712 help find problems with drivers that do not properly initialize
1713 their sg tables.
1714
1715 If unsure, say N.
1716
1b2439db
AV
1717config DEBUG_NOTIFIERS
1718 bool "Debug notifier call chains"
1719 depends on DEBUG_KERNEL
1720 help
1721 Enable this to turn on sanity checking for notifier call chains.
1722 This is most useful for kernel developers to make sure that
1723 modules properly unregister themselves from notifier chains.
1724 This is a relatively cheap check but if you care about maximum
1725 performance, say N.
1726
8c8d2d96
KO
1727config DEBUG_CLOSURES
1728 bool "Debug closures (bcache async widgits)"
1729 depends on CLOSURES
1730 select DEBUG_FS
1731 help
1732 Keeps all active closures in a linked list and provides a debugfs
1733 interface to list them, which makes it possible to see asynchronous
1734 operations that get stuck.
1735
54a611b6
LH
1736config DEBUG_MAPLE_TREE
1737 bool "Debug maple trees"
1738 depends on DEBUG_KERNEL
1739 help
1740 Enable maple tree debugging information and extra validations.
1741
1742 If unsure, say N.
1743
3be5cbcd
CD
1744endmenu
1745
43a0a2a7 1746source "kernel/rcu/Kconfig.debug"
2f03e3ca 1747
f303fccb
TH
1748config DEBUG_WQ_FORCE_RR_CPU
1749 bool "Force round-robin CPU selection for unbound work items"
1750 depends on DEBUG_KERNEL
1751 default n
1752 help
1753 Workqueue used to implicitly guarantee that work items queued
1754 without explicit CPU specified are put on the local CPU. This
1755 guarantee is no longer true and while local CPU is still
1756 preferred work items may be put on foreign CPUs. Kernel
1757 parameter "workqueue.debug_force_rr_cpu" is added to force
1758 round-robin CPU selection to flush out usages which depend on the
1759 now broken guarantee. This config option enables the debug
1760 feature by default. When enabled, memory and cache locality will
1761 be impacted.
1762
757c989b
TG
1763config CPU_HOTPLUG_STATE_CONTROL
1764 bool "Enable CPU hotplug state control"
1765 depends on DEBUG_KERNEL
1766 depends on HOTPLUG_CPU
1767 default n
1768 help
1769 Allows to write steps between "offline" and "online" to the CPUs
1770 sysfs target file so states can be stepped granular. This is a debug
1771 option for now as the hotplug machinery cannot be stopped and
1772 restarted at arbitrary points yet.
1773
1774 Say N if your are unsure.
1775
09a74952
CD
1776config LATENCYTOP
1777 bool "Latency measuring infrastructure"
1778 depends on DEBUG_KERNEL
1779 depends on STACKTRACE_SUPPORT
1780 depends on PROC_FS
7d37cb2c 1781 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
09a74952
CD
1782 select KALLSYMS
1783 select KALLSYMS_ALL
1784 select STACKTRACE
1785 select SCHEDSTATS
09a74952
CD
1786 help
1787 Enable this option if you want to use the LatencyTOP tool
1788 to find out which userspace is blocking on what kernel operations.
1789
6ab42860
TH
1790config DEBUG_CGROUP_REF
1791 bool "Disable inlining of cgroup css reference count functions"
1792 depends on DEBUG_KERNEL
1793 depends on CGROUPS
1794 depends on KPROBES
1795 default n
1796 help
1797 Force cgroup css reference count functions to not be inlined so
1798 that they can be kprobed for debugging.
1799
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1800source "kernel/trace/Kconfig"
1801
1802config PROVIDE_OHCI1394_DMA_INIT
1803 bool "Remote debugging over FireWire early on boot"
1804 depends on PCI && X86
1805 help
1806 If you want to debug problems which hang or crash the kernel early
1807 on boot and the crashing machine has a FireWire port, you can use
1808 this feature to remotely access the memory of the crashed machine
1809 over FireWire. This employs remote DMA as part of the OHCI1394
1810 specification which is now the standard for FireWire controllers.
1811
1812 With remote DMA, you can monitor the printk buffer remotely using
1813 firescope and access all memory below 4GB using fireproxy from gdb.
1814 Even controlling a kernel debugger is possible using remote DMA.
1815
1816 Usage:
1817
1818 If ohci1394_dma=early is used as boot parameter, it will initialize
1819 all OHCI1394 controllers which are found in the PCI config space.
1820
1821 As all changes to the FireWire bus such as enabling and disabling
1822 devices cause a bus reset and thereby disable remote DMA for all
1823 devices, be sure to have the cable plugged and FireWire enabled on
1824 the debugging host before booting the debug target for debugging.
1825
1826 This code (~1k) is freed after boot. By then, the firewire stack
1827 in charge of the OHCI-1394 controllers should be used instead.
1828
a74e2a22 1829 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1830
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1831source "samples/Kconfig"
1832
1833config ARCH_HAS_DEVMEM_IS_ALLOWED
1834 bool
1835
1836config STRICT_DEVMEM
1837 bool "Filter access to /dev/mem"
1838 depends on MMU && DEVMEM
527701ed 1839 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
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CD
1840 default y if PPC || X86 || ARM64
1841 help
1842 If this option is disabled, you allow userspace (root) access to all
1843 of memory, including kernel and userspace memory. Accidental
1844 access to this is obviously disastrous, but specific access can
1845 be used by people debugging the kernel. Note that with PAT support
1846 enabled, even in this case there are restrictions on /dev/mem
1847 use due to the cache aliasing requirements.
1848
1849 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1850 file only allows userspace access to PCI space and the BIOS code and
1851 data regions. This is sufficient for dosemu and X and all common
1852 users of /dev/mem.
1853
1854 If in doubt, say Y.
1855
1856config IO_STRICT_DEVMEM
1857 bool "Filter I/O access to /dev/mem"
1858 depends on STRICT_DEVMEM
1859 help
1860 If this option is disabled, you allow userspace (root) access to all
1861 io-memory regardless of whether a driver is actively using that
1862 range. Accidental access to this is obviously disastrous, but
1863 specific access can be used by people debugging kernel drivers.
1864
1865 If this option is switched on, the /dev/mem file only allows
1866 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1867 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1868 if the driver using a given range cannot be disabled.
1869
1870 If in doubt, say Y.
1871
1872menu "$(SRCARCH) Debugging"
1873
1874source "arch/$(SRCARCH)/Kconfig.debug"
1875
1876endmenu
1877
1878menu "Kernel Testing and Coverage"
1879
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1880source "lib/kunit/Kconfig"
1881
8d438288
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1882config NOTIFIER_ERROR_INJECTION
1883 tristate "Notifier error injection"
1884 depends on DEBUG_KERNEL
1885 select DEBUG_FS
1886 help
e41e85cc 1887 This option provides the ability to inject artificial errors to
8d438288
AM
1888 specified notifier chain callbacks. It is useful to test the error
1889 handling of notifier call chain failures.
1890
1891 Say N if unsure.
1892
048b9c35
AM
1893config PM_NOTIFIER_ERROR_INJECT
1894 tristate "PM notifier error injection module"
1895 depends on PM && NOTIFIER_ERROR_INJECTION
1896 default m if PM_DEBUG
1897 help
e41e85cc 1898 This option provides the ability to inject artificial errors to
048b9c35
AM
1899 PM notifier chain callbacks. It is controlled through debugfs
1900 interface /sys/kernel/debug/notifier-error-inject/pm
1901
1902 If the notifier call chain should be failed with some events
1903 notified, write the error code to "actions/<notifier event>/error".
1904
1905 Example: Inject PM suspend error (-12 = -ENOMEM)
1906
1907 # cd /sys/kernel/debug/notifier-error-inject/pm/
1908 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1909 # echo mem > /sys/power/state
1910 bash: echo: write error: Cannot allocate memory
1911
1912 To compile this code as a module, choose M here: the module will
1913 be called pm-notifier-error-inject.
1914
1915 If unsure, say N.
1916
d526e85f
BH
1917config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1918 tristate "OF reconfig notifier error injection module"
1919 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1920 help
e41e85cc 1921 This option provides the ability to inject artificial errors to
d526e85f 1922 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1923 through debugfs interface under
d526e85f 1924 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1925
1926 If the notifier call chain should be failed with some events
1927 notified, write the error code to "actions/<notifier event>/error".
1928
1929 To compile this code as a module, choose M here: the module will
e12a95f4 1930 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1931
1932 If unsure, say N.
1933
02fff96a
NA
1934config NETDEV_NOTIFIER_ERROR_INJECT
1935 tristate "Netdev notifier error injection module"
1936 depends on NET && NOTIFIER_ERROR_INJECTION
1937 help
1938 This option provides the ability to inject artificial errors to
1939 netdevice notifier chain callbacks. It is controlled through debugfs
1940 interface /sys/kernel/debug/notifier-error-inject/netdev
1941
1942 If the notifier call chain should be failed with some events
1943 notified, write the error code to "actions/<notifier event>/error".
1944
1945 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1946
1947 # cd /sys/kernel/debug/notifier-error-inject/netdev
1948 # echo -22 > actions/NETDEV_CHANGEMTU/error
1949 # ip link set eth0 mtu 1024
1950 RTNETLINK answers: Invalid argument
1951
1952 To compile this code as a module, choose M here: the module will
1953 be called netdev-notifier-error-inject.
1954
1955 If unsure, say N.
1956
f1b4bd06 1957config FUNCTION_ERROR_INJECTION
a4412fdd 1958 bool "Fault-injections of functions"
f1b4bd06 1959 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
a4412fdd
SRG
1960 help
1961 Add fault injections into various functions that are annotated with
1962 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
ca0f2cfc 1963 value of these functions. This is useful to test error paths of code.
a4412fdd
SRG
1964
1965 If unsure, say N
f1b4bd06 1966
6ff1cb35 1967config FAULT_INJECTION
1ab8509a
AM
1968 bool "Fault-injection framework"
1969 depends on DEBUG_KERNEL
329409ae
AM
1970 help
1971 Provide fault-injection framework.
1972 For more details, see Documentation/fault-injection/.
6ff1cb35 1973
8a8b6502 1974config FAILSLAB
1ab8509a
AM
1975 bool "Fault-injection capability for kmalloc"
1976 depends on FAULT_INJECTION
8a8b6502 1977 help
1ab8509a 1978 Provide fault-injection capability for kmalloc.
8a8b6502 1979
933e312e 1980config FAIL_PAGE_ALLOC
29b46fa3 1981 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1982 depends on FAULT_INJECTION
933e312e 1983 help
1ab8509a 1984 Provide fault-injection capability for alloc_pages().
933e312e 1985
2c739ced
AL
1986config FAULT_INJECTION_USERCOPY
1987 bool "Fault injection capability for usercopy functions"
1988 depends on FAULT_INJECTION
1989 help
1990 Provides fault-injection capability to inject failures
1991 in usercopy functions (copy_from_user(), get_user(), ...).
1992
c17bb495 1993config FAIL_MAKE_REQUEST
86327d19 1994 bool "Fault-injection capability for disk IO"
581d4e28 1995 depends on FAULT_INJECTION && BLOCK
c17bb495 1996 help
1ab8509a 1997 Provide fault-injection capability for disk IO.
c17bb495 1998
581d4e28 1999config FAIL_IO_TIMEOUT
f4d01439 2000 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
2001 depends on FAULT_INJECTION && BLOCK
2002 help
2003 Provide fault-injection capability on end IO handling. This
2004 will make the block layer "forget" an interrupt as configured,
2005 thus exercising the error handling.
2006
2007 Only works with drivers that use the generic timeout handling,
9dbbc3b9 2008 for others it won't do anything.
581d4e28 2009
ab51fbab
DB
2010config FAIL_FUTEX
2011 bool "Fault-injection capability for futexes"
2012 select DEBUG_FS
2013 depends on FAULT_INJECTION && FUTEX
2014 help
2015 Provide fault-injection capability for futexes.
2016
f1b4bd06
MP
2017config FAULT_INJECTION_DEBUG_FS
2018 bool "Debugfs entries for fault-injection capabilities"
2019 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2020 help
2021 Enable configuration of fault-injection capabilities via debugfs.
2022
4b1a29a7
MH
2023config FAIL_FUNCTION
2024 bool "Fault-injection capability for functions"
2025 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2026 help
2027 Provide function-based fault-injection capability.
2028 This will allow you to override a specific function with a return
2029 with given return value. As a result, function caller will see
2030 an error value and have to handle it. This is useful to test the
2031 error handling in various subsystems.
2032
f1b4bd06
MP
2033config FAIL_MMC_REQUEST
2034 bool "Fault-injection capability for MMC IO"
2035 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 2036 help
f1b4bd06
MP
2037 Provide fault-injection capability for MMC IO.
2038 This will make the mmc core return data errors. This is
2039 useful to test the error handling in the mmc block device
2040 and to test how the mmc host driver handles retries from
2041 the block device.
1df49008 2042
c782af25
CL
2043config FAIL_SUNRPC
2044 bool "Fault-injection capability for SunRPC"
2045 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2046 help
2047 Provide fault-injection capability for SunRPC and
2048 its consumers.
2049
4668c7a2
AM
2050config FAULT_INJECTION_CONFIGFS
2051 bool "Configfs interface for fault-injection capabilities"
d325c162
AM
2052 depends on FAULT_INJECTION
2053 select CONFIGFS_FS
4668c7a2
AM
2054 help
2055 This option allows configfs-based drivers to dynamically configure
2056 fault-injection via configfs. Each parameter for driver-specific
2057 fault-injection can be made visible as a configfs attribute in a
2058 configfs group.
2059
2060
1df49008
AM
2061config FAULT_INJECTION_STACKTRACE_FILTER
2062 bool "stacktrace filter for fault-injection capabilities"
4668c7a2
AM
2063 depends on FAULT_INJECTION
2064 depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
1df49008 2065 select STACKTRACE
7d37cb2c 2066 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1df49008
AM
2067 help
2068 Provide stacktrace filter for fault-injection capabilities
267c4025 2069
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2070config ARCH_HAS_KCOV
2071 bool
cc3fa840 2072 help
09a74952
CD
2073 An architecture should select this when it can successfully
2074 build and run with CONFIG_KCOV. This typically requires
2075 disabling instrumentation for some early boot code.
cc3fa840 2076
09a74952
CD
2077config CC_HAS_SANCOV_TRACE_PC
2078 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 2079
cc3fa840 2080
09a74952
CD
2081config KCOV
2082 bool "Code coverage for fuzzing"
2083 depends on ARCH_HAS_KCOV
2084 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
22102f45 2085 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
bece04b5 2086 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
09a74952
CD
2087 select DEBUG_FS
2088 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
22102f45 2089 select OBJTOOL if HAVE_NOINSTR_HACK
09a74952
CD
2090 help
2091 KCOV exposes kernel code coverage information in a form suitable
2092 for coverage-guided fuzzing (randomized testing).
cc3fa840 2093
09a74952 2094 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 2095
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CD
2096config KCOV_ENABLE_COMPARISONS
2097 bool "Enable comparison operands collection by KCOV"
2098 depends on KCOV
2099 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2100 help
2101 KCOV also exposes operands of every comparison in the instrumented
2102 code along with operand sizes and PCs of the comparison instructions.
2103 These operands can be used by fuzzing engines to improve the quality
2104 of fuzzing coverage.
cc3fa840 2105
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CD
2106config KCOV_INSTRUMENT_ALL
2107 bool "Instrument all code by default"
2108 depends on KCOV
2109 default y
2110 help
2111 If you are doing generic system call fuzzing (like e.g. syzkaller),
2112 then you will want to instrument the whole kernel and you should
2113 say y here. If you are doing more targeted fuzzing (like e.g.
2114 filesystem fuzzing with AFL) then you will want to enable coverage
2115 for more specific subsets of files, and should say n here.
84bc809e 2116
5ff3b30a
AK
2117config KCOV_IRQ_AREA_SIZE
2118 hex "Size of interrupt coverage collection area in words"
2119 depends on KCOV
2120 default 0x40000
2121 help
2122 KCOV uses preallocated per-cpu areas to collect coverage from
2123 soft interrupts. This specifies the size of those areas in the
2124 number of unsigned long words.
2125
d3deafaa
VL
2126menuconfig RUNTIME_TESTING_MENU
2127 bool "Runtime Testing"
908009e8 2128 def_bool y
d3deafaa
VL
2129
2130if RUNTIME_TESTING_MENU
881c5149 2131
d5528cc1
GU
2132config TEST_DHRY
2133 tristate "Dhrystone benchmark test"
2134 help
2135 Enable this to include the Dhrystone 2.1 benchmark. This test
2136 calculates the number of Dhrystones per second, and the number of
2137 DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2138 by 1757 (the number of Dhrystones per second obtained on the VAX
2139 11/780, nominally a 1 MIPS machine).
2140
2141 To run the benchmark, it needs to be enabled explicitly, either from
2142 the kernel command line (when built-in), or from userspace (when
2143 built-in or modular.
2144
2145 Run once during kernel boot:
2146
2147 test_dhry.run
2148
2149 Set number of iterations from kernel command line:
2150
2151 test_dhry.iterations=<n>
2152
2153 Set number of iterations from userspace:
2154
2155 echo <n> > /sys/module/test_dhry/parameters/iterations
2156
2157 Trigger manual run from userspace:
2158
2159 echo y > /sys/module/test_dhry/parameters/run
2160
2161 If the number of iterations is <= 0, the test will devise a suitable
2162 number of iterations (test runs for at least 2s) automatically.
2163 This process takes ca. 4s.
2164
2165 If unsure, say N.
2166
881c5149
DH
2167config LKDTM
2168 tristate "Linux Kernel Dump Test Tool Module"
2169 depends on DEBUG_FS
881c5149
DH
2170 help
2171 This module enables testing of the different dumping mechanisms by
2172 inducing system failures at predefined crash points.
2173 If you don't need it: say N
2174 Choose M here to compile this code as a module. The module will be
2175 called lkdtm.
2176
2177 Documentation on how to use the module can be found in
10ffebbe 2178 Documentation/fault-injection/provoke-crashes.rst
881c5149 2179
d3c0ca49
SV
2180config CPUMASK_KUNIT_TEST
2181 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
c41e8866
SV
2182 depends on KUNIT
2183 default KUNIT_ALL_TESTS
2184 help
2185 Enable to turn on cpumask tests, running at boot or module load time.
2186
d3c0ca49
SV
2187 For more information on KUnit and unit tests in general, please refer
2188 to the KUnit documentation in Documentation/dev-tools/kunit/.
2189
c41e8866
SV
2190 If unsure, say N.
2191
881c5149 2192config TEST_LIST_SORT
ebd09577
DL
2193 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2194 depends on KUNIT
2195 default KUNIT_ALL_TESTS
881c5149
DH
2196 help
2197 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
2198 executed only once during system boot (so affects only boot time),
2199 or at module load time.
881c5149
DH
2200
2201 If unsure, say N.
2202
6e24628d
IR
2203config TEST_MIN_HEAP
2204 tristate "Min heap test"
2205 depends on DEBUG_KERNEL || m
2206 help
2207 Enable this to turn on min heap function tests. This test is
2208 executed only once during system boot (so affects only boot time),
2209 or at module load time.
2210
2211 If unsure, say N.
2212
c5adae95 2213config TEST_SORT
36f33b56
DL
2214 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2215 depends on KUNIT
2216 default KUNIT_ALL_TESTS
c5adae95 2217 help
5c4e6798
GU
2218 This option enables the self-test function of 'sort()' at boot,
2219 or at module load time.
c5adae95
KF
2220
2221 If unsure, say N.
2222
5086ea4b
MR
2223config TEST_DIV64
2224 tristate "64bit/32bit division and modulo test"
2225 depends on DEBUG_KERNEL || m
2226 help
2227 Enable this to turn on 'do_div()' function test. This test is
2228 executed only once during system boot (so affects only boot time),
2229 or at module load time.
2230
2231 If unsure, say N.
2232
2d71340f
DH
2233config TEST_IOV_ITER
2234 tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
2235 depends on KUNIT
2236 default KUNIT_ALL_TESTS
2237 help
2238 Enable this to turn on testing of the operation of the I/O iterator
2239 (iov_iter). This test is executed only once during system boot (so
2240 affects only boot time), or at module load time.
2241
2242 If unsure, say N.
2243
881c5149 2244config KPROBES_SANITY_TEST
dcbb2ee2 2245 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
881c5149
DH
2246 depends on DEBUG_KERNEL
2247 depends on KPROBES
e44e81c5 2248 depends on KUNIT
de3db3f8 2249 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
dcbb2ee2 2250 default KUNIT_ALL_TESTS
881c5149
DH
2251 help
2252 This option provides for testing basic kprobes functionality on
5a6cf77f 2253 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
2254 verified for functionality.
2255
2256 Say N if you are unsure.
2257
f4616fab
MH
2258config FPROBE_SANITY_TEST
2259 bool "Self test for fprobe"
2260 depends on DEBUG_KERNEL
2261 depends on FPROBE
2262 depends on KUNIT=y
2263 help
2264 This option will enable testing the fprobe when the system boot.
2265 A series of tests are made to verify that the fprobe is functioning
2266 properly.
2267
2268 Say N if you are unsure.
2269
881c5149
DH
2270config BACKTRACE_SELF_TEST
2271 tristate "Self test for the backtrace code"
2272 depends on DEBUG_KERNEL
881c5149
DH
2273 help
2274 This option provides a kernel module that can be used to test
2275 the kernel stack backtrace code. This option is not useful
2276 for distributions or general kernels, but only for kernel
2277 developers working on architecture code.
2278
2279 Note that if you want to also test saved backtraces, you will
2280 have to enable STACKTRACE as well.
2281
2282 Say N if you are unsure.
2283
914a7b50
ED
2284config TEST_REF_TRACKER
2285 tristate "Self test for reference tracker"
2286 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2287 select REF_TRACKER
2288 help
2289 This option provides a kernel module performing tests
2290 using reference tracker infrastructure.
2291
2292 Say N if you are unsure.
2293
910a742d
ML
2294config RBTREE_TEST
2295 tristate "Red-Black tree test"
7c993e11 2296 depends on DEBUG_KERNEL
910a742d
ML
2297 help
2298 A benchmark measuring the performance of the rbtree library.
2299 Also includes rbtree invariant checks.
2300
4b4f3acc
FB
2301config REED_SOLOMON_TEST
2302 tristate "Reed-Solomon library test"
2303 depends on DEBUG_KERNEL || m
2304 select REED_SOLOMON
2305 select REED_SOLOMON_ENC16
2306 select REED_SOLOMON_DEC16
2307 help
2308 This option enables the self-test function of rslib at boot,
2309 or at module load time.
2310
2311 If unsure, say N.
2312
fff3fd8a
ML
2313config INTERVAL_TREE_TEST
2314 tristate "Interval tree test"
0f789b67 2315 depends on DEBUG_KERNEL
a88cc108 2316 select INTERVAL_TREE
fff3fd8a
ML
2317 help
2318 A benchmark measuring the performance of the interval tree library
2319
623fd807
GT
2320config PERCPU_TEST
2321 tristate "Per cpu operations test"
2322 depends on m && DEBUG_KERNEL
2323 help
2324 Enable this option to build test module which validates per-cpu
2325 operations.
2326
2327 If unsure, say N.
2328
881c5149 2329config ATOMIC64_SELFTEST
55ded955 2330 tristate "Perform an atomic64_t self-test"
881c5149 2331 help
55ded955
GU
2332 Enable this option to test the atomic64_t functions at boot or
2333 at module load time.
881c5149
DH
2334
2335 If unsure, say N.
2336
2337config ASYNC_RAID6_TEST
2338 tristate "Self test for hardware accelerated raid6 recovery"
2339 depends on ASYNC_RAID6_RECOV
2340 select ASYNC_MEMCPY
a7f7f624 2341 help
881c5149
DH
2342 This is a one-shot self test that permutes through the
2343 recovery of all the possible two disk failure scenarios for a
2344 N-disk array. Recovery is performed with the asynchronous
2345 raid6 recovery routines, and will optionally use an offload
2346 engine if one is available.
2347
2348 If unsure, say N.
2349
64d1d77a
AS
2350config TEST_HEXDUMP
2351 tristate "Test functions located in the hexdump module at runtime"
2352
b2ff70a0
MC
2353config STRING_SELFTEST
2354 tristate "Test string functions at runtime"
2355
881c5149
DH
2356config TEST_STRING_HELPERS
2357 tristate "Test functions located in the string_helpers module at runtime"
2358
2359config TEST_KSTRTOX
2360 tristate "Test kstrto*() family of functions at runtime"
2361
707cc728
RV
2362config TEST_PRINTF
2363 tristate "Test printf() family of functions at runtime"
2364
50f530e1
RF
2365config TEST_SCANF
2366 tristate "Test scanf() family of functions at runtime"
2367
5fd003f5
DD
2368config TEST_BITMAP
2369 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2370 help
2371 Enable this option to test the bitmap functions at boot.
2372
2373 If unsure, say N.
2374
cfaff0e5
AS
2375config TEST_UUID
2376 tristate "Test functions located in the uuid module at runtime"
2377
ad3d6c72
MW
2378config TEST_XARRAY
2379 tristate "Test the XArray code at runtime"
2380
120b1162 2381config TEST_MAPLE_TREE
a5199577
LH
2382 tristate "Test the Maple Tree code at runtime or module load"
2383 help
2384 Enable this option to test the maple tree code functions at boot, or
2385 when the module is loaded. Enable "Debug Maple Trees" will enable
2386 more verbose output on failures.
2387
2388 If unsure, say N.
120b1162 2389
7e1e7763 2390config TEST_RHASHTABLE
9d6dbe1b 2391 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2392 help
2393 Enable this option to test the rhashtable functions at boot.
2394
2395 If unsure, say N.
2396
8ab8ba38
MW
2397config TEST_IDA
2398 tristate "Perform selftest on IDA functions"
2399
44091d29
JP
2400config TEST_PARMAN
2401 tristate "Perform selftest on priority array manager"
44091d29
JP
2402 depends on PARMAN
2403 help
2404 Enable this option to test priority array manager on boot
2405 (or module load).
2406
2407 If unsure, say N.
2408
6aed82de
DL
2409config TEST_IRQ_TIMINGS
2410 bool "IRQ timings selftest"
2411 depends on IRQ_TIMINGS
2412 help
2413 Enable this option to test the irq timings code on boot.
2414
2415 If unsure, say N.
2416
8a6f0b47 2417config TEST_LKM
93e9ef83 2418 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2419 depends on m
2420 help
2421 This builds the "test_module" module that emits "Hello, world"
2422 on printk when loaded. It is designed to be used for basic
2423 evaluation of the module loading subsystem (for example when
2424 validating module verification). It lacks any extra dependencies,
2425 and will not normally be loaded by the system unless explicitly
2426 requested by name.
2427
2428 If unsure, say N.
2429
c348c163 2430config TEST_BITOPS
6af132f3 2431 tristate "Test module for compilation of bitops operations"
c348c163
JB
2432 depends on m
2433 help
2434 This builds the "test_bitops" module that is much like the
2435 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2436 set/clear_bit macros and get_count_order/long to make sure there are
2437 no compiler warnings from C=1 sparse checker or -Wextra
2438 compilations. It has no dependencies and doesn't run or load unless
2439 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2440
2441 If unsure, say N.
2442
3f21a6b7
URS
2443config TEST_VMALLOC
2444 tristate "Test module for stress/performance analysis of vmalloc allocator"
2445 default n
2446 depends on MMU
2447 depends on m
2448 help
2449 This builds the "test_vmalloc" module that should be used for
2450 stress and performance analysis. So, any new change for vmalloc
2451 subsystem can be evaluated from performance and stability point
2452 of view.
2453
2454 If unsure, say N.
2455
3e2a4c18
KC
2456config TEST_USER_COPY
2457 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2458 depends on m
2459 help
2460 This builds the "test_user_copy" module that runs sanity checks
2461 on the copy_to/from_user infrastructure, making sure basic
2462 user/kernel boundary testing is working. If it fails to load,
2463 a regression has been detected in the user/kernel memory boundary
2464 protections.
2465
2466 If unsure, say N.
2467
64a8946b
AS
2468config TEST_BPF
2469 tristate "Test BPF filter functionality"
98920ba6 2470 depends on m && NET
64a8946b
AS
2471 help
2472 This builds the "test_bpf" module that runs various test vectors
2473 against the BPF interpreter or BPF JIT compiler depending on the
2474 current setting. This is in particular useful for BPF JIT compiler
2475 development, but also to run regression tests against changes in
3c731eba
AS
2476 the interpreter code. It also enables test stubs for eBPF maps and
2477 verifier used by user space verifier testsuite.
64a8946b
AS
2478
2479 If unsure, say N.
2480
509e56b3
MB
2481config TEST_BLACKHOLE_DEV
2482 tristate "Test blackhole netdev functionality"
2483 depends on m && NET
2484 help
2485 This builds the "test_blackhole_dev" module that validates the
2486 data path through this blackhole netdev.
2487
2488 If unsure, say N.
2489
dceeb3e7 2490config FIND_BIT_BENCHMARK
4441fca0 2491 tristate "Test find_bit functions"
4441fca0
YN
2492 help
2493 This builds the "test_find_bit" module that measure find_*_bit()
2494 functions performance.
2495
2496 If unsure, say N.
2497
0a8adf58
KC
2498config TEST_FIRMWARE
2499 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2500 depends on FW_LOADER
2501 help
2502 This builds the "test_firmware" module that creates a userspace
2503 interface for testing firmware loading. This can be used to
2504 control the triggering of firmware loading without needing an
2505 actual firmware-using device. The contents can be rechecked by
2506 userspace.
2507
2508 If unsure, say N.
2509
9308f2f9
LR
2510config TEST_SYSCTL
2511 tristate "sysctl test driver"
9308f2f9
LR
2512 depends on PROC_SYSCTL
2513 help
2514 This builds the "test_sysctl" module. This driver enables to test the
2515 proc sysctl interfaces available to drivers safely without affecting
2516 production knobs which might alter system functionality.
2517
2518 If unsure, say N.
2519
d2585f51 2520config BITFIELD_KUNIT
dcbb2ee2 2521 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
d2585f51 2522 depends on KUNIT
dcbb2ee2 2523 default KUNIT_ALL_TESTS
d2585f51
VMI
2524 help
2525 Enable this option to test the bitfield functions at boot.
2526
2527 KUnit tests run during boot and output the results to the debug log
2528 in TAP format (http://testanything.org/). Only useful for kernel devs
2529 running the KUnit test harness, and not intended for inclusion into a
2530 production build.
2531
2532 For more information on KUnit and unit tests in general please refer
2533 to the KUnit documentation in Documentation/dev-tools/kunit/.
2534
2535 If unsure, say N.
2536
688eb819
NG
2537config CHECKSUM_KUNIT
2538 tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
2539 depends on KUNIT
2540 default KUNIT_ALL_TESTS
2541 help
2542 Enable this option to test the checksum functions at boot.
2543
2544 KUnit tests run during boot and output the results to the debug log
2545 in TAP format (http://testanything.org/). Only useful for kernel devs
2546 running the KUnit test harness, and not intended for inclusion into a
2547 production build.
2548
2549 For more information on KUnit and unit tests in general please refer
2550 to the KUnit documentation in Documentation/dev-tools/kunit/.
2551
2552 If unsure, say N.
2553
0acc968f
IB
2554config HASH_KUNIT_TEST
2555 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2556 depends on KUNIT
2557 default KUNIT_ALL_TESTS
2558 help
2559 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2560 integer (<linux/hash.h>) hash functions on boot.
2561
2562 KUnit tests run during boot and output the results to the debug log
2563 in TAP format (https://testanything.org/). Only useful for kernel devs
2564 running the KUnit test harness, and not intended for inclusion into a
2565 production build.
2566
2567 For more information on KUnit and unit tests in general please refer
2568 to the KUnit documentation in Documentation/dev-tools/kunit/.
2569
2570 This is intended to help people writing architecture-specific
2571 optimized versions. If unsure, say N.
2572
5df38ca6 2573config RESOURCE_KUNIT_TEST
dcbb2ee2 2574 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
5df38ca6 2575 depends on KUNIT
dcbb2ee2 2576 default KUNIT_ALL_TESTS
5df38ca6
AS
2577 help
2578 This builds the resource API unit test.
2579 Tests the logic of API provided by resource.c and ioport.h.
2580 For more information on KUnit and unit tests in general please refer
2581 to the KUnit documentation in Documentation/dev-tools/kunit/.
2582
2583 If unsure, say N.
2584
2cb80dbb 2585config SYSCTL_KUNIT_TEST
5f215aab 2586 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2587 depends on KUNIT
5f215aab 2588 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2589 help
2590 This builds the proc sysctl unit test, which runs on boot.
2591 Tests the API contract and implementation correctness of sysctl.
2592 For more information on KUnit and unit tests in general please refer
2593 to the KUnit documentation in Documentation/dev-tools/kunit/.
2594
2595 If unsure, say N.
2596
ea2dd7c0 2597config LIST_KUNIT_TEST
5f215aab 2598 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2599 depends on KUNIT
5f215aab 2600 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2601 help
2602 This builds the linked list KUnit test suite.
2603 It tests that the API and basic functionality of the list_head type
2604 and associated macros.
2605
2606 KUnit tests run during boot and output the results to the debug log
d89775fc 2607 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2608 running the KUnit test harness, and not intended for inclusion into a
2609 production build.
2610
2611 For more information on KUnit and unit tests in general please refer
2612 to the KUnit documentation in Documentation/dev-tools/kunit/.
2613
2614 If unsure, say N.
2615
789538c6
RM
2616config HASHTABLE_KUNIT_TEST
2617 tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2618 depends on KUNIT
2619 default KUNIT_ALL_TESTS
2620 help
2621 This builds the hashtable KUnit test suite.
2622 It tests the basic functionality of the API defined in
2623 include/linux/hashtable.h. For more information on KUnit and
2624 unit tests in general please refer to the KUnit documentation
2625 in Documentation/dev-tools/kunit/.
2626
2627 If unsure, say N.
2628
33d599f0
MV
2629config LINEAR_RANGES_TEST
2630 tristate "KUnit test for linear_ranges"
2631 depends on KUNIT
2632 select LINEAR_RANGES
2633 help
2634 This builds the linear_ranges unit test, which runs on boot.
2635 Tests the linear_ranges logic correctness.
2636 For more information on KUnit and unit tests in general please refer
7546861a
AS
2637 to the KUnit documentation in Documentation/dev-tools/kunit/.
2638
2639 If unsure, say N.
2640
2641config CMDLINE_KUNIT_TEST
dcbb2ee2 2642 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
7546861a 2643 depends on KUNIT
dcbb2ee2 2644 default KUNIT_ALL_TESTS
7546861a
AS
2645 help
2646 This builds the cmdline API unit test.
2647 Tests the logic of API provided by cmdline.c.
2648 For more information on KUnit and unit tests in general please refer
33d599f0
MV
2649 to the KUnit documentation in Documentation/dev-tools/kunit/.
2650
2651 If unsure, say N.
2652
6d511020 2653config BITS_TEST
dcbb2ee2 2654 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
6d511020 2655 depends on KUNIT
dcbb2ee2 2656 default KUNIT_ALL_TESTS
6d511020
RF
2657 help
2658 This builds the bits unit test.
2659 Tests the logic of macros defined in bits.h.
2660 For more information on KUnit and unit tests in general please refer
2661 to the KUnit documentation in Documentation/dev-tools/kunit/.
2662
2663 If unsure, say N.
2664
1f9f78b1
OG
2665config SLUB_KUNIT_TEST
2666 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2667 depends on SLUB_DEBUG && KUNIT
2668 default KUNIT_ALL_TESTS
2669 help
2670 This builds SLUB allocator unit test.
2671 Tests SLUB cache debugging functionality.
2672 For more information on KUnit and unit tests in general please refer
2673 to the KUnit documentation in Documentation/dev-tools/kunit/.
2674
2675 If unsure, say N.
2676
b6c75c4a
TP
2677config RATIONAL_KUNIT_TEST
2678 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
8ba739ed 2679 depends on KUNIT && RATIONAL
b6c75c4a
TP
2680 default KUNIT_ALL_TESTS
2681 help
2682 This builds the rational math unit test.
2683 For more information on KUnit and unit tests in general please refer
2684 to the KUnit documentation in Documentation/dev-tools/kunit/.
2685
2686 If unsure, say N.
2687
bb95ebbe
KC
2688config MEMCPY_KUNIT_TEST
2689 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2690 depends on KUNIT
2691 default KUNIT_ALL_TESTS
2692 help
2693 Builds unit tests for memcpy(), memmove(), and memset() functions.
2694 For more information on KUnit and unit tests in general please refer
2695 to the KUnit documentation in Documentation/dev-tools/kunit/.
2696
2697 If unsure, say N.
2698
4acf1de3
KC
2699config MEMCPY_SLOW_KUNIT_TEST
2700 bool "Include exhaustive memcpy tests"
2701 depends on MEMCPY_KUNIT_TEST
2702 default y
2703 help
2704 Some memcpy tests are quite exhaustive in checking for overlaps
2705 and bit ranges. These can be very slow, so they are split out
2706 as a separate config, in case they need to be disabled.
2707
d055c6a2
RM
2708 Note this config option will be replaced by the use of KUnit test
2709 attributes.
2710
addbeea6
BVA
2711config IS_SIGNED_TYPE_KUNIT_TEST
2712 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2713 depends on KUNIT
2714 default KUNIT_ALL_TESTS
2715 help
2716 Builds unit tests for the is_signed_type() macro.
2717
2718 For more information on KUnit and unit tests in general please refer
2719 to the KUnit documentation in Documentation/dev-tools/kunit/.
2720
2721 If unsure, say N.
2722
617f55e2
KC
2723config OVERFLOW_KUNIT_TEST
2724 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2725 depends on KUNIT
2726 default KUNIT_ALL_TESTS
2727 help
2728 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2729 related functions.
2730
2731 For more information on KUnit and unit tests in general please refer
2732 to the KUnit documentation in Documentation/dev-tools/kunit/.
2733
2734 If unsure, say N.
2735
02788ebc
KC
2736config STACKINIT_KUNIT_TEST
2737 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2738 depends on KUNIT
2739 default KUNIT_ALL_TESTS
2740 help
2741 Test if the kernel is zero-initializing stack variables and
2742 padding. Coverage is controlled by compiler flags,
2743 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2744 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2745 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2746
875bfd52
KC
2747config FORTIFY_KUNIT_TEST
2748 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
5e2956ee 2749 depends on KUNIT && FORTIFY_SOURCE
875bfd52
KC
2750 default KUNIT_ALL_TESTS
2751 help
2752 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2753 by the str*() and mem*() family of functions. For testing runtime
2754 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2755
724c299c
ME
2756config HW_BREAKPOINT_KUNIT_TEST
2757 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2758 depends on HAVE_HW_BREAKPOINT
2759 depends on KUNIT=y
2760 default KUNIT_ALL_TESTS
2761 help
2762 Tests for hw_breakpoint constraints accounting.
2763
2764 If unsure, say N.
2765
3bf301e1
KC
2766config STRCAT_KUNIT_TEST
2767 tristate "Test strcat() family of functions at runtime" if !KUNIT_ALL_TESTS
2768 depends on KUNIT
2769 default KUNIT_ALL_TESTS
2770
41eefc46
KC
2771config STRSCPY_KUNIT_TEST
2772 tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
2773 depends on KUNIT
2774 default KUNIT_ALL_TESTS
2775
fb3d88ab
KC
2776config SIPHASH_KUNIT_TEST
2777 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2778 depends on KUNIT
2779 default KUNIT_ALL_TESTS
2780 help
2781 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2782 functions on boot (or module load).
2783
2784 This is intended to help people writing architecture-specific
2785 optimized versions. If unsure, say N.
2786
e704f93a
DR
2787config TEST_UDELAY
2788 tristate "udelay test driver"
e704f93a
DR
2789 help
2790 This builds the "udelay_test" module that helps to make sure
2791 that udelay() is working properly.
2792
2793 If unsure, say N.
2794
2bf9e0ab
IM
2795config TEST_STATIC_KEYS
2796 tristate "Test static keys"
579e1acb
JB
2797 depends on m
2798 help
2bf9e0ab 2799 Test the static key interfaces.
579e1acb
JB
2800
2801 If unsure, say N.
2802
683263a5
JC
2803config TEST_DYNAMIC_DEBUG
2804 tristate "Test DYNAMIC_DEBUG"
2805 depends on DYNAMIC_DEBUG
2806 help
2807 This module registers a tracer callback to count enabled
2808 pr_debugs in a 'do_debugging' function, then alters their
2809 enablements, calls the function, and compares counts.
2810
2811 If unsure, say N.
2812
d9c6a72d
LR
2813config TEST_KMOD
2814 tristate "kmod stress tester"
d9c6a72d 2815 depends on m
d9c6a72d 2816 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2817 depends on BLOCK
bbd2e05f 2818 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
d9c6a72d
LR
2819 select TEST_LKM
2820 select XFS_FS
2821 select TUN
2822 select BTRFS_FS
2823 help
2824 Test the kernel's module loading mechanism: kmod. kmod implements
2825 support to load modules using the Linux kernel's usermode helper.
2826 This test provides a series of tests against kmod.
2827
2828 Although technically you can either build test_kmod as a module or
2829 into the kernel we disallow building it into the kernel since
2830 it stress tests request_module() and this will very likely cause
2831 some issues by taking over precious threads available from other
2832 module load requests, ultimately this could be fatal.
2833
2834 To run tests run:
2835
2836 tools/testing/selftests/kmod/kmod.sh --help
2837
2838 If unsure, say N.
2839
e4dace36
FF
2840config TEST_DEBUG_VIRTUAL
2841 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2842 depends on DEBUG_VIRTUAL
2843 help
2844 Test the kernel's ability to detect incorrect calls to
2845 virt_to_phys() done against the non-linear part of the
2846 kernel's virtual address map.
2847
2848 If unsure, say N.
2849
ce76d938
AS
2850config TEST_MEMCAT_P
2851 tristate "Test memcat_p() helper function"
2852 help
2853 Test the memcat_p() helper for correctly merging two
2854 pointer arrays together.
2855
2856 If unsure, say N.
2857
a2818ee4
JL
2858config TEST_LIVEPATCH
2859 tristate "Test livepatching"
2860 default n
bae05437 2861 depends on DYNAMIC_DEBUG
a2818ee4
JL
2862 depends on LIVEPATCH
2863 depends on m
2864 help
2865 Test kernel livepatching features for correctness. The tests will
2866 load test modules that will be livepatched in various scenarios.
2867
2868 To run all the livepatching tests:
2869
2870 make -C tools/testing/selftests TARGETS=livepatch run_tests
2871
2872 Alternatively, individual tests may be invoked:
2873
2874 tools/testing/selftests/livepatch/test-callbacks.sh
2875 tools/testing/selftests/livepatch/test-livepatch.sh
2876 tools/testing/selftests/livepatch/test-shadow-vars.sh
2877
2878 If unsure, say N.
2879
0a020d41
JP
2880config TEST_OBJAGG
2881 tristate "Perform selftest on object aggreration manager"
2882 default n
2883 depends on OBJAGG
2884 help
2885 Enable this option to test object aggregation manager on boot
2886 (or module load).
2887
5015a300
AP
2888config TEST_MEMINIT
2889 tristate "Test heap/page initialization"
2890 help
2891 Test if the kernel is zero-initializing heap and page allocations.
2892 This can be useful to test init_on_alloc and init_on_free features.
2893
2894 If unsure, say N.
2895
b2ef9f5a
RC
2896config TEST_HMM
2897 tristate "Test HMM (Heterogeneous Memory Management)"
2898 depends on TRANSPARENT_HUGEPAGE
2899 depends on DEVICE_PRIVATE
2900 select HMM_MIRROR
2901 select MMU_NOTIFIER
2902 help
2903 This is a pseudo device driver solely for testing HMM.
2904 Say M here if you want to build the HMM test module.
2905 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2906
2907 If unsure, say N.
2908
e320d301
MWO
2909config TEST_FREE_PAGES
2910 tristate "Test freeing pages"
2911 help
2912 Test that a memory leak does not occur due to a race between
2913 freeing a block of pages and a speculative page reference.
2914 Loading this module is safe if your kernel has the bug fixed.
2915 If the bug is not fixed, it will leak gigabytes of memory and
2916 probably OOM your system.
2917
4185b3b9
PA
2918config TEST_FPU
2919 tristate "Test floating point operations in kernel space"
2920 depends on X86 && !KCOV_INSTRUMENT_ALL
2921 help
2922 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2923 which will trigger a sequence of floating point operations. This is used
2924 for self-testing floating point control register setting in
2925 kernel_fpu_begin().
2926
2927 If unsure, say N.
2928
1253b9b8
PM
2929config TEST_CLOCKSOURCE_WATCHDOG
2930 tristate "Test clocksource watchdog in kernel space"
2931 depends on CLOCKSOURCE_WATCHDOG
2932 help
2933 Enable this option to create a kernel module that will trigger
2934 a test of the clocksource watchdog. This module may be loaded
2935 via modprobe or insmod in which case it will run upon being
2936 loaded, or it may be built in, in which case it will run
2937 shortly after boot.
2938
2939 If unsure, say N.
2940
92f90d3b 2941config TEST_OBJPOOL
2942 tristate "Test module for correctness and stress of objpool"
2943 default n
2944 depends on m && DEBUG_KERNEL
2945 help
2946 This builds the "test_objpool" module that should be used for
2947 correctness verification and concurrent testings of objects
2948 allocation and reclamation.
2949
2950 If unsure, say N.
2951
d3deafaa 2952endif # RUNTIME_TESTING_MENU
cc3fa840 2953
dce44566
AK
2954config ARCH_USE_MEMTEST
2955 bool
2956 help
2957 An architecture should select this when it uses early_memtest()
2958 during boot process.
2959
cc3fa840
RD
2960config MEMTEST
2961 bool "Memtest"
dce44566 2962 depends on ARCH_USE_MEMTEST
a7f7f624 2963 help
cc3fa840 2964 This option adds a kernel parameter 'memtest', which allows memtest
dce44566 2965 to be set and executed.
cc3fa840
RD
2966 memtest=0, mean disabled; -- default
2967 memtest=1, mean do 1 test pattern;
2968 ...
2969 memtest=17, mean do 17 test patterns.
2970 If you are unsure how to answer this question, answer N.
2971
21266be9 2972
06ec64b8 2973
af9ca6f9
BB
2974config HYPERV_TESTING
2975 bool "Microsoft Hyper-V driver testing"
2976 default n
2977 depends on HYPERV && DEBUG_FS
2978 help
2979 Select this option to enable Hyper-V vmbus testing.
2980
045f6d79
CD
2981endmenu # "Kernel Testing and Coverage"
2982
2f7ab126
MO
2983menu "Rust hacking"
2984
2985config RUST_DEBUG_ASSERTIONS
2986 bool "Debug assertions"
2987 depends on RUST
2988 help
2989 Enables rustc's `-Cdebug-assertions` codegen option.
2990
2991 This flag lets you turn `cfg(debug_assertions)` conditional
2992 compilation on or off. This can be used to enable extra debugging
2993 code in development but not in production. For example, it controls
2994 the behavior of the standard library's `debug_assert!` macro.
2995
2996 Note that this will apply to all Rust code, including `core`.
2997
2998 If unsure, say N.
2999
3000config RUST_OVERFLOW_CHECKS
3001 bool "Overflow checks"
3002 default y
3003 depends on RUST
3004 help
3005 Enables rustc's `-Coverflow-checks` codegen option.
3006
3007 This flag allows you to control the behavior of runtime integer
3008 overflow. When overflow-checks are enabled, a Rust panic will occur
3009 on overflow.
3010
3011 Note that this will apply to all Rust code, including `core`.
3012
3013 If unsure, say Y.
3014
ecaa6ddf
GG
3015config RUST_BUILD_ASSERT_ALLOW
3016 bool "Allow unoptimized build-time assertions"
3017 depends on RUST
3018 help
3019 Controls how are `build_error!` and `build_assert!` handled during build.
3020
3021 If calls to them exist in the binary, it may indicate a violated invariant
3022 or that the optimizer failed to verify the invariant during compilation.
3023
3024 This should not happen, thus by default the build is aborted. However,
3025 as an escape hatch, you can choose Y here to ignore them during build
3026 and let the check be carried at runtime (with `panic!` being called if
3027 the check fails).
3028
3029 If unsure, say N.
3030
a66d733d
MO
3031config RUST_KERNEL_DOCTESTS
3032 bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
3033 depends on RUST && KUNIT=y
3034 default KUNIT_ALL_TESTS
3035 help
3036 This builds the documentation tests of the `kernel` crate
3037 as KUnit tests.
3038
3039 For more information on KUnit and unit tests in general,
3040 please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
3041
3042 If unsure, say N.
3043
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MO
3044endmenu # "Rust"
3045
06ec64b8 3046endmenu # Kernel hacking