bpf: Assign ID to vmlinux BTF and return extra info for BTF in GET_OBJ_INFO
[linux-2.6-block.git] / lib / Kconfig.debug
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ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
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21config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
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38config CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
40 range 1 15
41 default "7"
42 help
43 Default loglevel to determine what will be printed on the console.
44
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
48
50f4d9bd 49 Note: This does not affect the log level of un-prefixed printk()
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50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
51 option.
52
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53config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
55 range 1 15
56 default "4"
57 help
58 loglevel to use when "quiet" is passed on the kernel commandline.
59
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
63
42a9dc0b 64config MESSAGE_LOGLEVEL_DEFAULT
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65 int "Default message log level (1-7)"
66 range 1 7
67 default "4"
68 help
69 Default log level for printk statements with no specified priority.
70
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
73 priority.
74
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75 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
78
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79config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
82 help
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
86 using "boot_delay=N".
87
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
96
97config DYNAMIC_DEBUG
98 bool "Enable dynamic printk() support"
99 default n
100 depends on PRINTK
239a5791 101 depends on (DEBUG_FS || PROC_FS)
ceabef7d 102 select DYNAMIC_DEBUG_CORE
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103 help
104
105 Compiles debug level messages into the kernel, which would not
106 otherwise be available at runtime. These messages can then be
107 enabled/disabled based on various levels of scope - per source file,
108 function, module, format string, and line number. This mechanism
109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
110 enlarges the kernel text size by about 2%.
111
112 If a source file is compiled with DEBUG flag set, any
113 pr_debug() calls in it are enabled by default, but can be
114 disabled at runtime as below. Note that DEBUG flag is
115 turned on by many CONFIG_*DEBUG* options.
116
117 Usage:
118
119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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120 which is contained in the 'debugfs' filesystem or procfs.
121 Thus, the debugfs or procfs filesystem must first be mounted before
122 making use of this feature.
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123 We refer the control file as: <debugfs>/dynamic_debug/control. This
124 file contains a list of the debug statements that can be enabled. The
125 format for each line of the file is:
126
127 filename:lineno [module]function flags format
128
129 filename : source file of the debug statement
130 lineno : line number of the debug statement
131 module : module that contains the debug statement
132 function : function that contains the debug statement
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133 flags : '=p' means the line is turned 'on' for printing
134 format : the format used for the debug statement
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135
136 From a live system:
137
138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
139 # filename:lineno [module]function flags format
140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
143
144 Example usage:
145
146 // enable the message at line 1603 of file svcsock.c
147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
148 <debugfs>/dynamic_debug/control
149
150 // enable all the messages in file svcsock.c
151 nullarbor:~ # echo -n 'file svcsock.c +p' >
152 <debugfs>/dynamic_debug/control
153
154 // enable all the messages in the NFS server module
155 nullarbor:~ # echo -n 'module nfsd +p' >
156 <debugfs>/dynamic_debug/control
157
158 // enable all 12 messages in the function svc_process()
159 nullarbor:~ # echo -n 'func svc_process +p' >
160 <debugfs>/dynamic_debug/control
161
162 // disable all 12 messages in the function svc_process()
163 nullarbor:~ # echo -n 'func svc_process -p' >
164 <debugfs>/dynamic_debug/control
165
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166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
167 information.
604ff0dc 168
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169config DYNAMIC_DEBUG_CORE
170 bool "Enable core function of dynamic debug support"
171 depends on PRINTK
172 depends on (DEBUG_FS || PROC_FS)
173 help
174 Enable core functional support of dynamic debug. It is useful
175 when you want to tie dynamic debug to your kernel modules with
176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
177 the case of embedded system where the kernel image size is
178 sensitive for people.
179
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180config SYMBOLIC_ERRNAME
181 bool "Support symbolic error names in printf"
182 default y if PRINTK
183 help
184 If you say Y here, the kernel's printf implementation will
185 be able to print symbolic error names such as ENOSPC instead
186 of the number 28. It makes the kernel image slightly larger
187 (about 3KB), but can make the kernel logs easier to read.
188
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189config DEBUG_BUGVERBOSE
190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
192 default y
193 help
194 Say Y here to make BUG() panics output the file name and line number
195 of the BUG call as well as the EIP and oops trace. This aids
196 debugging but costs about 70-100K of memory.
197
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198endmenu # "printk and dmesg options"
199
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200menu "Compile-time checks and compiler options"
201
202config DEBUG_INFO
203 bool "Compile the kernel with debug info"
12b13835 204 depends on DEBUG_KERNEL && !COMPILE_TEST
6dfc0665 205 help
68d4b3df 206 If you say Y here the resulting kernel image will include
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207 debugging info resulting in a larger kernel image.
208 This adds debug symbols to the kernel and modules (gcc -g), and
209 is needed if you intend to use kernel crashdump or binary object
210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
211 Say Y here only if you plan to debug the kernel.
212
213 If unsure, say N.
214
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215if DEBUG_INFO
216
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217config DEBUG_INFO_REDUCED
218 bool "Reduce debugging information"
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219 help
220 If you say Y here gcc is instructed to generate less debugging
221 information for structure types. This means that tools that
222 need full debugging information (like kgdb or systemtap) won't
223 be happy. But if you merely need debugging information to
224 resolve line numbers there is no loss. Advantage is that
225 build directory object sizes shrink dramatically over a full
226 DEBUG_INFO build and compile times are reduced too.
227 Only works with newer gcc versions.
228
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229config DEBUG_INFO_COMPRESSED
230 bool "Compressed debugging information"
10e68b02 231 depends on $(cc-option,-gz=zlib)
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232 depends on $(ld-option,--compress-debug-sections=zlib)
233 help
234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
235 5.0+, binutils 2.26+, and zlib.
236
237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
238 size of their debug .deb packages with this config set, due to the
239 debug info being compressed with zlib, then the object files being
240 recompressed with a different compression scheme. But this is still
241 preferable to setting $KDEB_COMPRESS to "none" which would be even
242 larger.
243
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244config DEBUG_INFO_SPLIT
245 bool "Produce split debuginfo in .dwo files"
9d937444 246 depends on $(cc-option,-gsplit-dwarf)
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247 help
248 Generate debug info into separate .dwo files. This significantly
249 reduces the build directory size for builds with DEBUG_INFO,
250 because it stores the information only once on disk in .dwo
251 files instead of multiple times in object files and executables.
252 In addition the debug information is also compressed.
253
254 Requires recent gcc (4.7+) and recent gdb/binutils.
255 Any tool that packages or reads debug information would need
256 to know about the .dwo files and include them.
257 Incompatible with older versions of ccache.
258
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259config DEBUG_INFO_DWARF4
260 bool "Generate dwarf4 debuginfo"
9d937444 261 depends on $(cc-option,-gdwarf-4)
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262 help
263 Generate dwarf4 debug info. This requires recent versions
264 of gcc and gdb. It makes the debug information larger.
265 But it significantly improves the success of resolving
266 variables in gdb on optimized code.
267
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268config DEBUG_INFO_BTF
269 bool "Generate BTF typeinfo"
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270 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
271 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
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272 help
273 Generate deduplicated BTF type information from DWARF debug info.
274 Turning this on expects presence of pahole tool, which will convert
275 DWARF type info into equivalent deduplicated BTF type info.
276
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277config GDB_SCRIPTS
278 bool "Provide GDB scripts for kernel debugging"
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279 help
280 This creates the required links to GDB helper scripts in the
281 build directory. If you load vmlinux into gdb, the helper
282 scripts will be automatically imported by gdb as well, and
283 additional functions are available to analyze a Linux kernel
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284 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
285 for further details.
3ee7b3fa 286
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287endif # DEBUG_INFO
288
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289config ENABLE_MUST_CHECK
290 bool "Enable __must_check logic"
291 default y
292 help
293 Enable the __must_check logic in the kernel build. Disable this to
294 suppress the "warning: ignoring return value of 'foo', declared with
295 attribute warn_unused_result" messages.
1da177e4 296
35bb5b1e 297config FRAME_WARN
a83e4ca2 298 int "Warn for stack frames larger than"
35bb5b1e 299 range 0 8192
0e07f663 300 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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301 default 1280 if (!64BIT && PARISC)
302 default 1024 if (!64BIT && !PARISC)
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303 default 2048 if 64BIT
304 help
305 Tell gcc to warn at build time for stack frames larger than this.
306 Setting this too low will cause a lot of warnings.
307 Setting it to 0 disables the warning.
35bb5b1e 308
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309config STRIP_ASM_SYMS
310 bool "Strip assembler-generated symbols during link"
311 default n
312 help
313 Strip internal assembler-generated symbols during a link (symbols
314 that look like '.Lxxx') so they don't pollute the output of
315 get_wchan() and suchlike.
316
1873e870 317config READABLE_ASM
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318 bool "Generate readable assembler code"
319 depends on DEBUG_KERNEL
bf4735a4 320 help
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321 Disable some compiler optimizations that tend to generate human unreadable
322 assembler output. This may make the kernel slightly slower, but it helps
323 to keep kernel developers who have to stare a lot at assembler listings
324 sane.
bf4735a4 325
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326config HEADERS_INSTALL
327 bool "Install uapi headers to usr/include"
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328 depends on !UML
329 help
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330 This option will install uapi headers (headers exported to user-space)
331 into the usr/include directory for use during the kernel build.
332 This is unneeded for building the kernel itself, but needed for some
333 user-space program samples. It is also needed by some features such
334 as uapi header sanity checks.
335
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336config DEBUG_SECTION_MISMATCH
337 bool "Enable full Section mismatch analysis"
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338 help
339 The section mismatch analysis checks if there are illegal
340 references from one section to another section.
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341 During linktime or runtime, some sections are dropped;
342 any use of code/data previously in these sections would
91341d4b 343 most likely result in an oops.
e809ab01 344 In the code, functions and variables are annotated with
0db0628d 345 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 346 which results in the code/data being placed in specific sections.
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347 The section mismatch analysis is always performed after a full
348 kernel build, and enabling this option causes the following
b7dca6dd 349 additional step to occur:
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350 - Add the option -fno-inline-functions-called-once to gcc commands.
351 When inlining a function annotated with __init in a non-init
352 function, we would lose the section information and thus
91341d4b 353 the analysis would not catch the illegal reference.
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354 This option tells gcc to inline less (but it does result in
355 a larger kernel).
91341d4b 356
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357config SECTION_MISMATCH_WARN_ONLY
358 bool "Make section mismatch errors non-fatal"
359 default y
360 help
361 If you say N here, the build process will fail if there are any
362 section mismatch, instead of just throwing warnings.
363
364 If unsure, say Y.
365
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366config DEBUG_FORCE_FUNCTION_ALIGN_32B
367 bool "Force all function address 32B aligned" if EXPERT
368 help
369 There are cases that a commit from one domain changes the function
370 address alignment of other domains, and cause magic performance
371 bump (regression or improvement). Enable this option will help to
372 verify if the bump is caused by function alignment changes, while
373 it will slightly increase the kernel size and affect icache usage.
374
375 It is mainly for debug and performance tuning use.
376
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377#
378# Select this config option from the architecture Kconfig, if it
379# is preferred to always offer frame pointers as a config
380# option on the architecture (regardless of KERNEL_DEBUG):
381#
382config ARCH_WANT_FRAME_POINTERS
383 bool
f346f4b3 384
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385config FRAME_POINTER
386 bool "Compile the kernel with frame pointers"
a687a533 387 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 388 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 389 help
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390 If you say Y here the resulting kernel image will be slightly
391 larger and slower, but it gives very useful debugging information
392 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 393
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394config STACK_VALIDATION
395 bool "Compile-time stack metadata validation"
396 depends on HAVE_STACK_VALIDATION
397 default n
398 help
399 Add compile-time checks to validate stack metadata, including frame
400 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
401 that runtime stack traces are more reliable.
402
ee9f8fce 403 This is also a prerequisite for generation of ORC unwind data, which
11af8474 404 is needed for CONFIG_UNWINDER_ORC.
ee9f8fce 405
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406 For more information, see
407 tools/objtool/Documentation/stack-validation.txt.
408
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409config VMLINUX_VALIDATION
410 bool
411 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
412 default y
413
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414config DEBUG_FORCE_WEAK_PER_CPU
415 bool "Force weak per-cpu definitions"
416 depends on DEBUG_KERNEL
8446f1d3 417 help
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418 s390 and alpha require percpu variables in modules to be
419 defined weak to work around addressing range issue which
420 puts the following two restrictions on percpu variable
421 definitions.
8446f1d3 422
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423 1. percpu symbols must be unique whether static or not
424 2. percpu variables can't be defined inside a function
8446f1d3 425
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426 To ensure that generic code follows the above rules, this
427 option forces all percpu variables to be defined as weak.
5f329089 428
6dfc0665 429endmenu # "Compiler options"
8446f1d3 430
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431menu "Generic Kernel Debugging Instruments"
432
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433config MAGIC_SYSRQ
434 bool "Magic SysRq key"
435 depends on !UML
436 help
437 If you say Y here, you will have some control over the system even
438 if the system crashes for example during kernel debugging (e.g., you
439 will be able to flush the buffer cache to disk, reboot the system
440 immediately or dump some status information). This is accomplished
441 by pressing various keys while holding SysRq (Alt+PrintScreen). It
442 also works on a serial console (on PC hardware at least), if you
443 send a BREAK and then within 5 seconds a command keypress. The
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444 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
445 Don't say Y unless you really know what this hack does.
8446f1d3 446
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447config MAGIC_SYSRQ_DEFAULT_ENABLE
448 hex "Enable magic SysRq key functions by default"
449 depends on MAGIC_SYSRQ
450 default 0x1
451 help
452 Specifies which SysRq key functions are enabled by default.
453 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 454 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 455
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456config MAGIC_SYSRQ_SERIAL
457 bool "Enable magic SysRq key over serial"
458 depends on MAGIC_SYSRQ
459 default y
460 help
461 Many embedded boards have a disconnected TTL level serial which can
462 generate some garbage that can lead to spurious false sysrq detects.
463 This option allows you to decide whether you want to enable the
464 magic SysRq key.
465
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466config MAGIC_SYSRQ_SERIAL_SEQUENCE
467 string "Char sequence that enables magic SysRq over serial"
468 depends on MAGIC_SYSRQ_SERIAL
469 default ""
470 help
471 Specifies a sequence of characters that can follow BREAK to enable
472 SysRq on a serial console.
473
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474 If unsure, leave an empty string and the option will not be enabled.
475
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476config DEBUG_FS
477 bool "Debug Filesystem"
478 help
479 debugfs is a virtual file system that kernel developers use to put
480 debugging files into. Enable this option to be able to read and
481 write to these files.
482
483 For detailed documentation on the debugfs API, see
484 Documentation/filesystems/.
485
486 If unsure, say N.
487
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488choice
489 prompt "Debugfs default access"
490 depends on DEBUG_FS
491 default DEBUG_FS_ALLOW_ALL
492 help
493 This selects the default access restrictions for debugfs.
494 It can be overridden with kernel command line option
495 debugfs=[on,no-mount,off]. The restrictions apply for API access
496 and filesystem registration.
497
498config DEBUG_FS_ALLOW_ALL
499 bool "Access normal"
500 help
501 No restrictions apply. Both API and filesystem registration
502 is on. This is the normal default operation.
503
504config DEBUG_FS_DISALLOW_MOUNT
505 bool "Do not register debugfs as filesystem"
506 help
507 The API is open but filesystem is not loaded. Clients can still do
508 their work and read with debug tools that do not need
509 debugfs filesystem.
510
511config DEBUG_FS_ALLOW_NONE
512 bool "No access"
513 help
514 Access is off. Clients get -PERM when trying to create nodes in
515 debugfs tree and debugfs is not registered as a filesystem.
516 Client can then back-off or continue without debugfs access.
517
518endchoice
519
6210b640 520source "lib/Kconfig.kgdb"
6210b640 521source "lib/Kconfig.ubsan"
2645d432 522source "lib/Kconfig.kcsan"
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523
524endmenu
525
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526config DEBUG_KERNEL
527 bool "Kernel debugging"
fef2c9bc 528 help
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529 Say Y here if you are developing drivers or trying to debug and
530 identify kernel problems.
fef2c9bc 531
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532config DEBUG_MISC
533 bool "Miscellaneous debug code"
534 default DEBUG_KERNEL
535 depends on DEBUG_KERNEL
536 help
537 Say Y here if you need to enable miscellaneous debug code that should
538 be under a more specific debug option but isn't.
539
540
0610c8a8 541menu "Memory Debugging"
fef2c9bc 542
8636a1f9 543source "mm/Kconfig.debug"
fef2c9bc 544
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545config DEBUG_OBJECTS
546 bool "Debug object operations"
547 depends on DEBUG_KERNEL
9c44bc03 548 help
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549 If you say Y here, additional code will be inserted into the
550 kernel to track the life time of various objects and validate
551 the operations on those objects.
9c44bc03 552
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553config DEBUG_OBJECTS_SELFTEST
554 bool "Debug objects selftest"
555 depends on DEBUG_OBJECTS
556 help
557 This enables the selftest of the object debug code.
9c44bc03 558
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559config DEBUG_OBJECTS_FREE
560 bool "Debug objects in freed memory"
561 depends on DEBUG_OBJECTS
562 help
563 This enables checks whether a k/v free operation frees an area
564 which contains an object which has not been deactivated
565 properly. This can make kmalloc/kfree-intensive workloads
566 much slower.
3ac7fe5a 567
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568config DEBUG_OBJECTS_TIMERS
569 bool "Debug timer objects"
570 depends on DEBUG_OBJECTS
571 help
572 If you say Y here, additional code will be inserted into the
573 timer routines to track the life time of timer objects and
574 validate the timer operations.
575
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576config DEBUG_OBJECTS_WORK
577 bool "Debug work objects"
578 depends on DEBUG_OBJECTS
579 help
580 If you say Y here, additional code will be inserted into the
581 work queue routines to track the life time of work objects and
582 validate the work operations.
583
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584config DEBUG_OBJECTS_RCU_HEAD
585 bool "Debug RCU callbacks objects"
fc2ecf7e 586 depends on DEBUG_OBJECTS
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587 help
588 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
589
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590config DEBUG_OBJECTS_PERCPU_COUNTER
591 bool "Debug percpu counter objects"
592 depends on DEBUG_OBJECTS
593 help
594 If you say Y here, additional code will be inserted into the
595 percpu counter routines to track the life time of percpu counter
596 objects and validate the percpu counter operations.
597
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598config DEBUG_OBJECTS_ENABLE_DEFAULT
599 int "debug_objects bootup default value (0-1)"
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600 range 0 1
601 default "1"
602 depends on DEBUG_OBJECTS
603 help
604 Debug objects boot parameter default value
3ae70205 605
1da177e4 606config DEBUG_SLAB
4a2f0acf 607 bool "Debug slab memory allocations"
4675ff05 608 depends on DEBUG_KERNEL && SLAB
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609 help
610 Say Y here to have the kernel do limited verification on memory
611 allocation as well as poisoning memory on free to catch use of freed
612 memory. This can make kmalloc/kfree-intensive workloads much slower.
613
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614config SLUB_DEBUG_ON
615 bool "SLUB debugging on by default"
4675ff05 616 depends on SLUB && SLUB_DEBUG
f0630fff
CL
617 default n
618 help
619 Boot with debugging on by default. SLUB boots by default with
620 the runtime debug capabilities switched off. Enabling this is
621 equivalent to specifying the "slub_debug" parameter on boot.
622 There is no support for more fine grained debug control like
623 possible with slub_debug=xxx. SLUB debugging may be switched
624 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
625 "slub_debug=-".
626
8ff12cfc
CL
627config SLUB_STATS
628 default n
629 bool "Enable SLUB performance statistics"
ab4d5ed5 630 depends on SLUB && SYSFS
8ff12cfc
CL
631 help
632 SLUB statistics are useful to debug SLUBs allocation behavior in
633 order find ways to optimize the allocator. This should never be
634 enabled for production use since keeping statistics slows down
635 the allocator by a few percentage points. The slabinfo command
636 supports the determination of the most active slabs to figure
637 out which slabs are relevant to a particular load.
638 Try running: slabinfo -DA
639
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CM
640config HAVE_DEBUG_KMEMLEAK
641 bool
642
3bba00d7
CM
643config DEBUG_KMEMLEAK
644 bool "Kernel memory leak detector"
525c1f92 645 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 646 select DEBUG_FS
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CM
647 select STACKTRACE if STACKTRACE_SUPPORT
648 select KALLSYMS
b60e26a2 649 select CRC32
3bba00d7
CM
650 help
651 Say Y here if you want to enable the memory leak
652 detector. The memory allocation/freeing is traced in a way
653 similar to the Boehm's conservative garbage collector, the
654 difference being that the orphan objects are not freed but
655 only shown in /sys/kernel/debug/kmemleak. Enabling this
656 feature will introduce an overhead to memory
700199b0 657 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
658 details.
659
0610c8a8
DH
660 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
661 of finding leaks due to the slab objects poisoning.
662
663 In order to access the kmemleak file, debugfs needs to be
664 mounted (usually at /sys/kernel/debug).
665
c5665868
CM
666config DEBUG_KMEMLEAK_MEM_POOL_SIZE
667 int "Kmemleak memory pool size"
0610c8a8 668 depends on DEBUG_KMEMLEAK
c59180ae 669 range 200 1000000
b751c52b 670 default 16000
0610c8a8
DH
671 help
672 Kmemleak must track all the memory allocations to avoid
673 reporting false positives. Since memory may be allocated or
c5665868
CM
674 freed before kmemleak is fully initialised, use a static pool
675 of metadata objects to track such callbacks. After kmemleak is
676 fully initialised, this memory pool acts as an emergency one
677 if slab allocations fail.
0610c8a8
DH
678
679config DEBUG_KMEMLEAK_TEST
680 tristate "Simple test for the kernel memory leak detector"
681 depends on DEBUG_KMEMLEAK && m
682 help
683 This option enables a module that explicitly leaks memory.
684
685 If unsure, say N.
686
687config DEBUG_KMEMLEAK_DEFAULT_OFF
688 bool "Default kmemleak to off"
689 depends on DEBUG_KMEMLEAK
690 help
691 Say Y here to disable kmemleak by default. It can then be enabled
692 on the command line via kmemleak=on.
693
d53ce042
SK
694config DEBUG_KMEMLEAK_AUTO_SCAN
695 bool "Enable kmemleak auto scan thread on boot up"
696 default y
697 depends on DEBUG_KMEMLEAK
698 help
699 Depending on the cpu, kmemleak scan may be cpu intensive and can
700 stall user tasks at times. This option enables/disables automatic
701 kmemleak scan at boot up.
702
703 Say N here to disable kmemleak auto scan thread to stop automatic
704 scanning. Disabling this option disables automatic reporting of
705 memory leaks.
706
707 If unsure, say Y.
708
0610c8a8
DH
709config DEBUG_STACK_USAGE
710 bool "Stack utilization instrumentation"
6c31da34 711 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
712 help
713 Enables the display of the minimum amount of free stack which each
714 task has ever had available in the sysrq-T and sysrq-P debug output.
715
716 This option will slow down process creation somewhat.
717
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718config SCHED_STACK_END_CHECK
719 bool "Detect stack corruption on calls to schedule()"
720 depends on DEBUG_KERNEL
721 default n
722 help
723 This option checks for a stack overrun on calls to schedule().
724 If the stack end location is found to be over written always panic as
725 the content of the corrupted region can no longer be trusted.
726 This is to ensure no erroneous behaviour occurs which could result in
727 data corruption or a sporadic crash at a later stage once the region
728 is examined. The runtime overhead introduced is minimal.
729
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730config ARCH_HAS_DEBUG_VM_PGTABLE
731 bool
732 help
733 An architecture should select this when it can successfully
734 build and run DEBUG_VM_PGTABLE.
735
0610c8a8
DH
736config DEBUG_VM
737 bool "Debug VM"
738 depends on DEBUG_KERNEL
739 help
740 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 741 that may impact performance.
0610c8a8
DH
742
743 If unsure, say N.
744
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DB
745config DEBUG_VM_VMACACHE
746 bool "Debug VMA caching"
747 depends on DEBUG_VM
748 help
749 Enable this to turn on VMA caching debug information. Doing so
750 can cause significant overhead, so only enable it in non-production
751 environments.
752
753 If unsure, say N.
754
0610c8a8
DH
755config DEBUG_VM_RB
756 bool "Debug VM red-black trees"
757 depends on DEBUG_VM
758 help
a663dad6 759 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
760
761 If unsure, say N.
762
95ad9755
KS
763config DEBUG_VM_PGFLAGS
764 bool "Debug page-flags operations"
765 depends on DEBUG_VM
766 help
767 Enables extra validation on page flags operations.
768
769 If unsure, say N.
770
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AK
771config DEBUG_VM_PGTABLE
772 bool "Debug arch page table for semantics compliance"
773 depends on MMU
774 depends on ARCH_HAS_DEBUG_VM_PGTABLE
775 default y if DEBUG_VM
776 help
777 This option provides a debug method which can be used to test
778 architecture page table helper functions on various platforms in
779 verifying if they comply with expected generic MM semantics. This
780 will help architecture code in making sure that any changes or
781 new additions of these helpers still conform to expected
782 semantics of the generic MM. Platforms will have to opt in for
783 this through ARCH_HAS_DEBUG_VM_PGTABLE.
784
785 If unsure, say N.
786
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787config ARCH_HAS_DEBUG_VIRTUAL
788 bool
789
0610c8a8
DH
790config DEBUG_VIRTUAL
791 bool "Debug VM translations"
fa5b6ec9 792 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
793 help
794 Enable some costly sanity checks in virtual to page code. This can
795 catch mistakes with virt_to_page() and friends.
796
797 If unsure, say N.
798
799config DEBUG_NOMMU_REGIONS
800 bool "Debug the global anon/private NOMMU mapping region tree"
801 depends on DEBUG_KERNEL && !MMU
802 help
803 This option causes the global tree of anonymous and private mapping
804 regions to be regularly checked for invalid topology.
805
806config DEBUG_MEMORY_INIT
807 bool "Debug memory initialisation" if EXPERT
808 default !EXPERT
809 help
810 Enable this for additional checks during memory initialisation.
811 The sanity checks verify aspects of the VM such as the memory model
812 and other information provided by the architecture. Verbose
813 information will be printed at KERN_DEBUG loglevel depending
814 on the mminit_loglevel= command-line option.
815
816 If unsure, say Y
817
818config MEMORY_NOTIFIER_ERROR_INJECT
819 tristate "Memory hotplug notifier error injection module"
820 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
821 help
822 This option provides the ability to inject artificial errors to
823 memory hotplug notifier chain callbacks. It is controlled through
824 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
825
826 If the notifier call chain should be failed with some events
827 notified, write the error code to "actions/<notifier event>/error".
828
829 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
830
831 # cd /sys/kernel/debug/notifier-error-inject/memory
832 # echo -12 > actions/MEM_GOING_OFFLINE/error
833 # echo offline > /sys/devices/system/memory/memoryXXX/state
834 bash: echo: write error: Cannot allocate memory
835
836 To compile this code as a module, choose M here: the module will
837 be called memory-notifier-error-inject.
838
839 If unsure, say N.
840
841config DEBUG_PER_CPU_MAPS
842 bool "Debug access to per_cpu maps"
843 depends on DEBUG_KERNEL
844 depends on SMP
845 help
846 Say Y to verify that the per_cpu map being accessed has
847 been set up. This adds a fair amount of code to kernel memory
848 and decreases performance.
849
850 Say N if unsure.
851
852config DEBUG_HIGHMEM
853 bool "Highmem debugging"
854 depends on DEBUG_KERNEL && HIGHMEM
855 help
b1357c9f
GU
856 This option enables additional error checking for high memory
857 systems. Disable for production systems.
0610c8a8
DH
858
859config HAVE_DEBUG_STACKOVERFLOW
860 bool
861
862config DEBUG_STACKOVERFLOW
863 bool "Check for stack overflows"
864 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 865 help
0610c8a8 866 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 867 and exception stacks (if your architecture uses them). This
0610c8a8
DH
868 option will show detailed messages if free stack space drops
869 below a certain limit.
870
871 These kinds of bugs usually occur when call-chains in the
872 kernel get too deep, especially when interrupts are
873 involved.
874
875 Use this in cases where you see apparently random memory
876 corruption, especially if it appears in 'struct thread_info'
877
878 If in doubt, say "N".
879
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AR
880source "lib/Kconfig.kasan"
881
0610c8a8
DH
882endmenu # "Memory Debugging"
883
a304e1b8
DW
884config DEBUG_SHIRQ
885 bool "Debug shared IRQ handlers"
0244ad00 886 depends on DEBUG_KERNEL
a304e1b8 887 help
0a2fae2a
WS
888 Enable this to generate a spurious interrupt just before a shared
889 interrupt handler is deregistered (generating one when registering
890 is currently disabled). Drivers need to handle this correctly. Some
891 don't and need to be caught.
a304e1b8 892
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CD
893menu "Debug Oops, Lockups and Hangs"
894
895config PANIC_ON_OOPS
896 bool "Panic on Oops"
897 help
898 Say Y here to enable the kernel to panic when it oopses. This
899 has the same effect as setting oops=panic on the kernel command
900 line.
901
902 This feature is useful to ensure that the kernel does not do
903 anything erroneous after an oops which could result in data
904 corruption or other issues.
905
906 Say N if unsure.
907
908config PANIC_ON_OOPS_VALUE
909 int
910 range 0 1
911 default 0 if !PANIC_ON_OOPS
912 default 1 if PANIC_ON_OOPS
913
914config PANIC_TIMEOUT
915 int "panic timeout"
916 default 0
917 help
9d5b134f 918 Set the timeout value (in seconds) until a reboot occurs when
f43a289d
CD
919 the kernel panics. If n = 0, then we wait forever. A timeout
920 value n > 0 will wait n seconds before rebooting, while a timeout
921 value n < 0 will reboot immediately.
92aef8fb 922
58687acb 923config LOCKUP_DETECTOR
05a4a952
NP
924 bool
925
926config SOFTLOCKUP_DETECTOR
927 bool "Detect Soft Lockups"
dea20a3f 928 depends on DEBUG_KERNEL && !S390
05a4a952 929 select LOCKUP_DETECTOR
8446f1d3 930 help
58687acb 931 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 932 soft lockups.
58687acb
DZ
933
934 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 935 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
936 chance to run. The current stack trace is displayed upon
937 detection and the system will stay locked up.
8446f1d3 938
5f00ae0d
RD
939config BOOTPARAM_SOFTLOCKUP_PANIC
940 bool "Panic (Reboot) On Soft Lockups"
941 depends on SOFTLOCKUP_DETECTOR
942 help
943 Say Y here to enable the kernel to panic on "soft lockups",
944 which are bugs that cause the kernel to loop in kernel
945 mode for more than 20 seconds (configurable using the watchdog_thresh
946 sysctl), without giving other tasks a chance to run.
947
948 The panic can be used in combination with panic_timeout,
949 to cause the system to reboot automatically after a
950 lockup has been detected. This feature is useful for
951 high-availability systems that have uptime guarantees and
952 where a lockup must be resolved ASAP.
953
954 Say N if unsure.
955
956config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
957 int
958 depends on SOFTLOCKUP_DETECTOR
959 range 0 1
960 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
961 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
962
05a4a952
NP
963config HARDLOCKUP_DETECTOR_PERF
964 bool
965 select SOFTLOCKUP_DETECTOR
966
7edaeb68
TG
967#
968# Enables a timestamp based low pass filter to compensate for perf based
969# hard lockup detection which runs too fast due to turbo modes.
970#
971config HARDLOCKUP_CHECK_TIMESTAMP
972 bool
973
05a4a952
NP
974#
975# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
976# lockup detector rather than the perf based detector.
977#
978config HARDLOCKUP_DETECTOR
979 bool "Detect Hard Lockups"
980 depends on DEBUG_KERNEL && !S390
981 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
982 select LOCKUP_DETECTOR
983 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
984 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
985 help
986 Say Y here to enable the kernel to act as a watchdog to detect
987 hard lockups.
988
58687acb 989 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 990 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
991 chance to run. The current stack trace is displayed upon detection
992 and the system will stay locked up.
8446f1d3 993
fef2c9bc
DZ
994config BOOTPARAM_HARDLOCKUP_PANIC
995 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 996 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
997 help
998 Say Y here to enable the kernel to panic on "hard lockups",
999 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
1000 mode with interrupts disabled for more than 10 seconds (configurable
1001 using the watchdog_thresh sysctl).
fef2c9bc
DZ
1002
1003 Say N if unsure.
1004
1005config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
1006 int
8f1f66ed 1007 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
1008 range 0 1
1009 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1010 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1011
e162b39a
MSB
1012config DETECT_HUNG_TASK
1013 bool "Detect Hung Tasks"
1014 depends on DEBUG_KERNEL
05a4a952 1015 default SOFTLOCKUP_DETECTOR
e162b39a 1016 help
0610c8a8
DH
1017 Say Y here to enable the kernel to detect "hung tasks",
1018 which are bugs that cause the task to be stuck in
96b03ab8 1019 uninterruptible "D" state indefinitely.
1da177e4 1020
0610c8a8
DH
1021 When a hung task is detected, the kernel will print the
1022 current stack trace (which you should report), but the
1023 task will stay in uninterruptible state. If lockdep is
1024 enabled then all held locks will also be reported. This
1025 feature has negligible overhead.
871751e2 1026
0610c8a8
DH
1027config DEFAULT_HUNG_TASK_TIMEOUT
1028 int "Default timeout for hung task detection (in seconds)"
1029 depends on DETECT_HUNG_TASK
1030 default 120
f0630fff 1031 help
0610c8a8
DH
1032 This option controls the default timeout (in seconds) used
1033 to determine when a task has become non-responsive and should
1034 be considered hung.
f0630fff 1035
0610c8a8
DH
1036 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1037 sysctl or by writing a value to
1038 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 1039
0610c8a8
DH
1040 A timeout of 0 disables the check. The default is two minutes.
1041 Keeping the default should be fine in most cases.
b69ec42b 1042
0610c8a8
DH
1043config BOOTPARAM_HUNG_TASK_PANIC
1044 bool "Panic (Reboot) On Hung Tasks"
1045 depends on DETECT_HUNG_TASK
3bba00d7 1046 help
0610c8a8
DH
1047 Say Y here to enable the kernel to panic on "hung tasks",
1048 which are bugs that cause the kernel to leave a task stuck
1049 in uninterruptible "D" state.
3bba00d7 1050
0610c8a8
DH
1051 The panic can be used in combination with panic_timeout,
1052 to cause the system to reboot automatically after a
1053 hung task has been detected. This feature is useful for
1054 high-availability systems that have uptime guarantees and
1055 where a hung tasks must be resolved ASAP.
bf96d1e3 1056
0610c8a8 1057 Say N if unsure.
bf96d1e3 1058
0610c8a8
DH
1059config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1060 int
1061 depends on DETECT_HUNG_TASK
1062 range 0 1
1063 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1064 default 1 if BOOTPARAM_HUNG_TASK_PANIC
3bba00d7 1065
82607adc
TH
1066config WQ_WATCHDOG
1067 bool "Detect Workqueue Stalls"
1068 depends on DEBUG_KERNEL
1069 help
1070 Say Y here to enable stall detection on workqueues. If a
1071 worker pool doesn't make forward progress on a pending work
1072 item for over a given amount of time, 30s by default, a
1073 warning message is printed along with dump of workqueue
1074 state. This can be configured through kernel parameter
1075 "workqueue.watchdog_thresh" and its sysfs counterpart.
1076
30428ef5
KK
1077config TEST_LOCKUP
1078 tristate "Test module to generate lockups"
63646bc9 1079 depends on m
30428ef5
KK
1080 help
1081 This builds the "test_lockup" module that helps to make sure
1082 that watchdogs and lockup detectors are working properly.
1083
1084 Depending on module parameters it could emulate soft or hard
1085 lockup, "hung task", or locking arbitrary lock for a long time.
1086 Also it could generate series of lockups with cooling-down periods.
1087
1088 If unsure, say N.
1089
92aef8fb
DH
1090endmenu # "Debug lockups and hangs"
1091
ebebdd09 1092menu "Scheduler Debugging"
5800dc3c 1093
0610c8a8
DH
1094config SCHED_DEBUG
1095 bool "Collect scheduler debugging info"
1096 depends on DEBUG_KERNEL && PROC_FS
1097 default y
0822ee4a 1098 help
0610c8a8
DH
1099 If you say Y here, the /proc/sched_debug file will be provided
1100 that can help debug the scheduler. The runtime overhead of this
1101 option is minimal.
0822ee4a 1102
f6db8347
NR
1103config SCHED_INFO
1104 bool
1105 default n
1106
0610c8a8
DH
1107config SCHEDSTATS
1108 bool "Collect scheduler statistics"
1109 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1110 select SCHED_INFO
0610c8a8
DH
1111 help
1112 If you say Y here, additional code will be inserted into the
1113 scheduler and related routines to collect statistics about
1114 scheduler behavior and provide them in /proc/schedstat. These
1115 stats may be useful for both tuning and debugging the scheduler
1116 If you aren't debugging the scheduler or trying to tune a specific
1117 application, you can say N to avoid the very slight overhead
1118 this adds.
0822ee4a 1119
ebebdd09 1120endmenu
0d9e2632 1121
3c17ad19
JS
1122config DEBUG_TIMEKEEPING
1123 bool "Enable extra timekeeping sanity checking"
1124 help
1125 This option will enable additional timekeeping sanity checks
1126 which may be helpful when diagnosing issues where timekeeping
1127 problems are suspected.
1128
1129 This may include checks in the timekeeping hotpaths, so this
1130 option may have a (very small) performance impact to some
1131 workloads.
1132
1133 If unsure, say N.
1134
1da177e4
LT
1135config DEBUG_PREEMPT
1136 bool "Debug preemptible kernel"
9f472869 1137 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1138 default y
1139 help
1140 If you say Y here then the kernel will use a debug variant of the
1141 commonly used smp_processor_id() function and will print warnings
1142 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1143 will detect preemption count underflows.
1144
9eade16b
DH
1145menu "Lock Debugging (spinlocks, mutexes, etc...)"
1146
f07cbebb
WL
1147config LOCK_DEBUGGING_SUPPORT
1148 bool
1149 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1150 default y
1151
19193bca
WL
1152config PROVE_LOCKING
1153 bool "Lock debugging: prove locking correctness"
1154 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1155 select LOCKDEP
1156 select DEBUG_SPINLOCK
1157 select DEBUG_MUTEXES
1158 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1159 select DEBUG_RWSEMS
19193bca
WL
1160 select DEBUG_WW_MUTEX_SLOWPATH
1161 select DEBUG_LOCK_ALLOC
8fd8ad5c 1162 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
19193bca
WL
1163 select TRACE_IRQFLAGS
1164 default n
1165 help
1166 This feature enables the kernel to prove that all locking
1167 that occurs in the kernel runtime is mathematically
1168 correct: that under no circumstance could an arbitrary (and
1169 not yet triggered) combination of observed locking
1170 sequences (on an arbitrary number of CPUs, running an
1171 arbitrary number of tasks and interrupt contexts) cause a
1172 deadlock.
1173
1174 In short, this feature enables the kernel to report locking
1175 related deadlocks before they actually occur.
1176
1177 The proof does not depend on how hard and complex a
1178 deadlock scenario would be to trigger: how many
1179 participant CPUs, tasks and irq-contexts would be needed
1180 for it to trigger. The proof also does not depend on
1181 timing: if a race and a resulting deadlock is possible
1182 theoretically (no matter how unlikely the race scenario
1183 is), it will be proven so and will immediately be
1184 reported by the kernel (once the event is observed that
1185 makes the deadlock theoretically possible).
1186
1187 If a deadlock is impossible (i.e. the locking rules, as
1188 observed by the kernel, are mathematically correct), the
1189 kernel reports nothing.
1190
1191 NOTE: this feature can also be enabled for rwlocks, mutexes
1192 and rwsems - in which case all dependencies between these
1193 different locking variants are observed and mapped too, and
1194 the proof of observed correctness is also maintained for an
1195 arbitrary combination of these separate locking variants.
1196
387b1468 1197 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1198
de8f5e4f
PZ
1199config PROVE_RAW_LOCK_NESTING
1200 bool "Enable raw_spinlock - spinlock nesting checks"
1201 depends on PROVE_LOCKING
1202 default n
1203 help
1204 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1205 that the lock nesting rules for PREEMPT_RT enabled kernels are
1206 not violated.
1207
1208 NOTE: There are known nesting problems. So if you enable this
1209 option expect lockdep splats until these problems have been fully
1210 addressed which is work in progress. This config switch allows to
1211 identify and analyze these problems. It will be removed and the
1212 check permanentely enabled once the main issues have been fixed.
1213
1214 If unsure, select N.
1215
19193bca
WL
1216config LOCK_STAT
1217 bool "Lock usage statistics"
1218 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1219 select LOCKDEP
1220 select DEBUG_SPINLOCK
1221 select DEBUG_MUTEXES
1222 select DEBUG_RT_MUTEXES if RT_MUTEXES
1223 select DEBUG_LOCK_ALLOC
1224 default n
1225 help
1226 This feature enables tracking lock contention points
1227
387b1468 1228 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1229
1230 This also enables lock events required by "perf lock",
1231 subcommand of perf.
1232 If you want to use "perf lock", you also need to turn on
1233 CONFIG_EVENT_TRACING.
1234
1235 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1236 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1237
e7eebaf6
IM
1238config DEBUG_RT_MUTEXES
1239 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1240 depends on DEBUG_KERNEL && RT_MUTEXES
1241 help
1242 This allows rt mutex semantics violations and rt mutex related
1243 deadlocks (lockups) to be detected and reported automatically.
1244
1da177e4 1245config DEBUG_SPINLOCK
4d9f34ad 1246 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1247 depends on DEBUG_KERNEL
e335e3eb 1248 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1249 help
1250 Say Y here and build SMP to catch missing spinlock initialization
1251 and certain other kinds of spinlock errors commonly made. This is
1252 best used in conjunction with the NMI watchdog so that spinlock
1253 deadlocks are also debuggable.
1254
4d9f34ad
IM
1255config DEBUG_MUTEXES
1256 bool "Mutex debugging: basic checks"
1257 depends on DEBUG_KERNEL
1258 help
1259 This feature allows mutex semantics violations to be detected and
1260 reported.
1261
23010027
DV
1262config DEBUG_WW_MUTEX_SLOWPATH
1263 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1264 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1265 select DEBUG_LOCK_ALLOC
1266 select DEBUG_SPINLOCK
1267 select DEBUG_MUTEXES
1268 help
1269 This feature enables slowpath testing for w/w mutex users by
1270 injecting additional -EDEADLK wound/backoff cases. Together with
1271 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1272 will test all possible w/w mutex interface abuse with the
1273 exception of simply not acquiring all the required locks.
4d692373
RC
1274 Note that this feature can introduce significant overhead, so
1275 it really should not be enabled in a production or distro kernel,
1276 even a debug kernel. If you are a driver writer, enable it. If
1277 you are a distro, do not.
23010027 1278
5149cbac
WL
1279config DEBUG_RWSEMS
1280 bool "RW Semaphore debugging: basic checks"
c71fd893 1281 depends on DEBUG_KERNEL
5149cbac 1282 help
c71fd893
WL
1283 This debugging feature allows mismatched rw semaphore locks
1284 and unlocks to be detected and reported.
5149cbac 1285
4d9f34ad
IM
1286config DEBUG_LOCK_ALLOC
1287 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1288 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad
IM
1289 select DEBUG_SPINLOCK
1290 select DEBUG_MUTEXES
f5694788 1291 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1292 select LOCKDEP
1293 help
1294 This feature will check whether any held lock (spinlock, rwlock,
1295 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1296 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1297 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1298 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1299 held during task exit.
1300
4d9f34ad
IM
1301config LOCKDEP
1302 bool
f07cbebb 1303 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1304 select STACKTRACE
f9b58e8c 1305 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
4d9f34ad
IM
1306 select KALLSYMS
1307 select KALLSYMS_ALL
1308
395102db
DJ
1309config LOCKDEP_SMALL
1310 bool
1311
4d9f34ad
IM
1312config DEBUG_LOCKDEP
1313 bool "Lock dependency engine debugging"
517e7aa5 1314 depends on DEBUG_KERNEL && LOCKDEP
4d9f34ad
IM
1315 help
1316 If you say Y here, the lock dependency engine will do
1317 additional runtime checks to debug itself, at the price
1318 of more runtime overhead.
1319
d902db1e
FW
1320config DEBUG_ATOMIC_SLEEP
1321 bool "Sleep inside atomic section checking"
e8f7c70f 1322 select PREEMPT_COUNT
1da177e4 1323 depends on DEBUG_KERNEL
87a4c375 1324 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1325 help
1326 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1327 noisy if they are called inside atomic sections: when a spinlock is
1328 held, inside an rcu read side critical section, inside preempt disabled
1329 sections, inside an interrupt, etc...
1da177e4 1330
cae2ed9a
IM
1331config DEBUG_LOCKING_API_SELFTESTS
1332 bool "Locking API boot-time self-tests"
1333 depends on DEBUG_KERNEL
1334 help
1335 Say Y here if you want the kernel to run a short self-test during
1336 bootup. The self-test checks whether common types of locking bugs
1337 are detected by debugging mechanisms or not. (if you disable
1338 lock debugging then those bugs wont be detected of course.)
1339 The following locking APIs are covered: spinlocks, rwlocks,
1340 mutexes and rwsems.
1341
0af3fe1e
PM
1342config LOCK_TORTURE_TEST
1343 tristate "torture tests for locking"
1344 depends on DEBUG_KERNEL
1345 select TORTURE_TEST
0af3fe1e
PM
1346 help
1347 This option provides a kernel module that runs torture tests
1348 on kernel locking primitives. The kernel module may be built
1349 after the fact on the running kernel to be tested, if desired.
1350
1351 Say Y here if you want kernel locking-primitive torture tests
1352 to be built into the kernel.
1353 Say M if you want these torture tests to build as a module.
1354 Say N if you are unsure.
1355
f2a5fec1
CW
1356config WW_MUTEX_SELFTEST
1357 tristate "Wait/wound mutex selftests"
1358 help
1359 This option provides a kernel module that runs tests on the
1360 on the struct ww_mutex locking API.
1361
1362 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1363 with this test harness.
1364
1365 Say M if you want these self tests to build as a module.
1366 Say N if you are unsure.
1367
e9d338a0
PM
1368config SCF_TORTURE_TEST
1369 tristate "torture tests for smp_call_function*()"
1370 depends on DEBUG_KERNEL
1371 select TORTURE_TEST
1372 help
1373 This option provides a kernel module that runs torture tests
1374 on the smp_call_function() family of primitives. The kernel
1375 module may be built after the fact on the running kernel to
1376 be tested, if desired.
1377
35feb604
PM
1378config CSD_LOCK_WAIT_DEBUG
1379 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1380 depends on DEBUG_KERNEL
1381 depends on 64BIT
1382 default n
1383 help
1384 This option enables debug prints when CPUs are slow to respond
1385 to the smp_call_function*() IPI wrappers. These debug prints
1386 include the IPI handler function currently executing (if any)
1387 and relevant stack traces.
1388
9eade16b 1389endmenu # lock debugging
8637c099 1390
9eade16b 1391config TRACE_IRQFLAGS
ed004953 1392 depends on TRACE_IRQFLAGS_SUPPORT
9eade16b 1393 bool
5ca43f6c 1394 help
9eade16b
DH
1395 Enables hooks to interrupt enabling and disabling for
1396 either tracing or lock debugging.
5ca43f6c 1397
ed004953 1398config TRACE_IRQFLAGS_NMI
1399 def_bool y
1400 depends on TRACE_IRQFLAGS
1401 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1402
8637c099 1403config STACKTRACE
0c38e1fe 1404 bool "Stack backtrace support"
8637c099 1405 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1406 help
1407 This option causes the kernel to create a /proc/pid/stack for
1408 every process, showing its current stack trace.
1409 It is also used by various kernel debugging features that require
1410 stack trace generation.
5ca43f6c 1411
eecabf56
TT
1412config WARN_ALL_UNSEEDED_RANDOM
1413 bool "Warn for all uses of unseeded randomness"
1414 default n
d06bfd19
JD
1415 help
1416 Some parts of the kernel contain bugs relating to their use of
1417 cryptographically secure random numbers before it's actually possible
1418 to generate those numbers securely. This setting ensures that these
1419 flaws don't go unnoticed, by enabling a message, should this ever
1420 occur. This will allow people with obscure setups to know when things
1421 are going wrong, so that they might contact developers about fixing
1422 it.
1423
eecabf56
TT
1424 Unfortunately, on some models of some architectures getting
1425 a fully seeded CRNG is extremely difficult, and so this can
1426 result in dmesg getting spammed for a surprisingly long
1427 time. This is really bad from a security perspective, and
1428 so architecture maintainers really need to do what they can
1429 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1430 However, since users cannot do anything actionable to
eecabf56
TT
1431 address this, by default the kernel will issue only a single
1432 warning for the first use of unseeded randomness.
1433
1434 Say Y here if you want to receive warnings for all uses of
1435 unseeded randomness. This will be of use primarily for
4c5d114e 1436 those developers interested in improving the security of
eecabf56
TT
1437 Linux kernels running on their architecture (or
1438 subarchitecture).
d06bfd19 1439
1da177e4
LT
1440config DEBUG_KOBJECT
1441 bool "kobject debugging"
1442 depends on DEBUG_KERNEL
1443 help
1444 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1445 to the syslog.
1da177e4 1446
c817a67e
RK
1447config DEBUG_KOBJECT_RELEASE
1448 bool "kobject release debugging"
2a999aa0 1449 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1450 help
1451 kobjects are reference counted objects. This means that their
1452 last reference count put is not predictable, and the kobject can
1453 live on past the point at which a driver decides to drop it's
1454 initial reference to the kobject gained on allocation. An
1455 example of this would be a struct device which has just been
1456 unregistered.
1457
1458 However, some buggy drivers assume that after such an operation,
1459 the memory backing the kobject can be immediately freed. This
1460 goes completely against the principles of a refcounted object.
1461
1462 If you say Y here, the kernel will delay the release of kobjects
1463 on the last reference count to improve the visibility of this
1464 kind of kobject release bug.
1465
9b2a60c4
CM
1466config HAVE_DEBUG_BUGVERBOSE
1467 bool
1468
3be5cbcd 1469menu "Debug kernel data structures"
1da177e4 1470
199a9afc
DJ
1471config DEBUG_LIST
1472 bool "Debug linked list manipulation"
4520bcb2 1473 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1474 help
1475 Enable this to turn on extended checks in the linked-list
1476 walking routines.
1477
1478 If unsure, say N.
1479
8e18faea 1480config DEBUG_PLIST
b8cfff68
DS
1481 bool "Debug priority linked list manipulation"
1482 depends on DEBUG_KERNEL
1483 help
1484 Enable this to turn on extended checks in the priority-ordered
1485 linked-list (plist) walking routines. This checks the entire
1486 list multiple times during each manipulation.
1487
1488 If unsure, say N.
1489
d6ec0842
JA
1490config DEBUG_SG
1491 bool "Debug SG table operations"
1492 depends on DEBUG_KERNEL
1493 help
1494 Enable this to turn on checks on scatter-gather tables. This can
1495 help find problems with drivers that do not properly initialize
1496 their sg tables.
1497
1498 If unsure, say N.
1499
1b2439db
AV
1500config DEBUG_NOTIFIERS
1501 bool "Debug notifier call chains"
1502 depends on DEBUG_KERNEL
1503 help
1504 Enable this to turn on sanity checking for notifier call chains.
1505 This is most useful for kernel developers to make sure that
1506 modules properly unregister themselves from notifier chains.
1507 This is a relatively cheap check but if you care about maximum
1508 performance, say N.
1509
3be5cbcd
CD
1510config BUG_ON_DATA_CORRUPTION
1511 bool "Trigger a BUG when data corruption is detected"
1512 select DEBUG_LIST
1513 help
1514 Select this option if the kernel should BUG when it encounters
1515 data corruption in kernel memory structures when they get checked
1516 for validity.
1517
1518 If unsure, say N.
1519
1520endmenu
1521
e0e81739
DH
1522config DEBUG_CREDENTIALS
1523 bool "Debug credential management"
1524 depends on DEBUG_KERNEL
1525 help
1526 Enable this to turn on some debug checking for credential
1527 management. The additional code keeps track of the number of
1528 pointers from task_structs to any given cred struct, and checks to
1529 see that this number never exceeds the usage count of the cred
1530 struct.
1531
1532 Furthermore, if SELinux is enabled, this also checks that the
1533 security pointer in the cred struct is never seen to be invalid.
1534
1535 If unsure, say N.
1536
43a0a2a7 1537source "kernel/rcu/Kconfig.debug"
2f03e3ca 1538
f303fccb
TH
1539config DEBUG_WQ_FORCE_RR_CPU
1540 bool "Force round-robin CPU selection for unbound work items"
1541 depends on DEBUG_KERNEL
1542 default n
1543 help
1544 Workqueue used to implicitly guarantee that work items queued
1545 without explicit CPU specified are put on the local CPU. This
1546 guarantee is no longer true and while local CPU is still
1547 preferred work items may be put on foreign CPUs. Kernel
1548 parameter "workqueue.debug_force_rr_cpu" is added to force
1549 round-robin CPU selection to flush out usages which depend on the
1550 now broken guarantee. This config option enables the debug
1551 feature by default. When enabled, memory and cache locality will
1552 be impacted.
1553
870d6656 1554config DEBUG_BLOCK_EXT_DEVT
68d4b3df 1555 bool "Force extended block device numbers and spread them"
870d6656
TH
1556 depends on DEBUG_KERNEL
1557 depends on BLOCK
759f8ca3 1558 default n
870d6656 1559 help
0e11e342
TH
1560 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1561 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1562 YOU ARE DOING. Distros, please enable this and fix whatever
1563 is broken.
1564
870d6656
TH
1565 Conventionally, block device numbers are allocated from
1566 predetermined contiguous area. However, extended block area
1567 may introduce non-contiguous block device numbers. This
1568 option forces most block device numbers to be allocated from
1569 the extended space and spreads them to discover kernel or
1570 userland code paths which assume predetermined contiguous
1571 device number allocation.
1572
55dc7db7
TH
1573 Note that turning on this debug option shuffles all the
1574 device numbers for all IDE and SCSI devices including libata
1575 ones, so root partition specified using device number
1576 directly (via rdev or root=MAJ:MIN) won't work anymore.
1577 Textual device names (root=/dev/sdXn) will continue to work.
1578
870d6656
TH
1579 Say N if you are unsure.
1580
757c989b
TG
1581config CPU_HOTPLUG_STATE_CONTROL
1582 bool "Enable CPU hotplug state control"
1583 depends on DEBUG_KERNEL
1584 depends on HOTPLUG_CPU
1585 default n
1586 help
1587 Allows to write steps between "offline" and "online" to the CPUs
1588 sysfs target file so states can be stepped granular. This is a debug
1589 option for now as the hotplug machinery cannot be stopped and
1590 restarted at arbitrary points yet.
1591
1592 Say N if your are unsure.
1593
09a74952
CD
1594config LATENCYTOP
1595 bool "Latency measuring infrastructure"
1596 depends on DEBUG_KERNEL
1597 depends on STACKTRACE_SUPPORT
1598 depends on PROC_FS
1599 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1600 select KALLSYMS
1601 select KALLSYMS_ALL
1602 select STACKTRACE
1603 select SCHEDSTATS
1604 select SCHED_DEBUG
1605 help
1606 Enable this option if you want to use the LatencyTOP tool
1607 to find out which userspace is blocking on what kernel operations.
1608
1609source "kernel/trace/Kconfig"
1610
1611config PROVIDE_OHCI1394_DMA_INIT
1612 bool "Remote debugging over FireWire early on boot"
1613 depends on PCI && X86
1614 help
1615 If you want to debug problems which hang or crash the kernel early
1616 on boot and the crashing machine has a FireWire port, you can use
1617 this feature to remotely access the memory of the crashed machine
1618 over FireWire. This employs remote DMA as part of the OHCI1394
1619 specification which is now the standard for FireWire controllers.
1620
1621 With remote DMA, you can monitor the printk buffer remotely using
1622 firescope and access all memory below 4GB using fireproxy from gdb.
1623 Even controlling a kernel debugger is possible using remote DMA.
1624
1625 Usage:
1626
1627 If ohci1394_dma=early is used as boot parameter, it will initialize
1628 all OHCI1394 controllers which are found in the PCI config space.
1629
1630 As all changes to the FireWire bus such as enabling and disabling
1631 devices cause a bus reset and thereby disable remote DMA for all
1632 devices, be sure to have the cable plugged and FireWire enabled on
1633 the debugging host before booting the debug target for debugging.
1634
1635 This code (~1k) is freed after boot. By then, the firewire stack
1636 in charge of the OHCI-1394 controllers should be used instead.
1637
a74e2a22 1638 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1639
045f6d79
CD
1640source "samples/Kconfig"
1641
1642config ARCH_HAS_DEVMEM_IS_ALLOWED
1643 bool
1644
1645config STRICT_DEVMEM
1646 bool "Filter access to /dev/mem"
1647 depends on MMU && DEVMEM
1648 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1649 default y if PPC || X86 || ARM64
1650 help
1651 If this option is disabled, you allow userspace (root) access to all
1652 of memory, including kernel and userspace memory. Accidental
1653 access to this is obviously disastrous, but specific access can
1654 be used by people debugging the kernel. Note that with PAT support
1655 enabled, even in this case there are restrictions on /dev/mem
1656 use due to the cache aliasing requirements.
1657
1658 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1659 file only allows userspace access to PCI space and the BIOS code and
1660 data regions. This is sufficient for dosemu and X and all common
1661 users of /dev/mem.
1662
1663 If in doubt, say Y.
1664
1665config IO_STRICT_DEVMEM
1666 bool "Filter I/O access to /dev/mem"
1667 depends on STRICT_DEVMEM
1668 help
1669 If this option is disabled, you allow userspace (root) access to all
1670 io-memory regardless of whether a driver is actively using that
1671 range. Accidental access to this is obviously disastrous, but
1672 specific access can be used by people debugging kernel drivers.
1673
1674 If this option is switched on, the /dev/mem file only allows
1675 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1676 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1677 if the driver using a given range cannot be disabled.
1678
1679 If in doubt, say Y.
1680
1681menu "$(SRCARCH) Debugging"
1682
1683source "arch/$(SRCARCH)/Kconfig.debug"
1684
1685endmenu
1686
1687menu "Kernel Testing and Coverage"
1688
09a74952
CD
1689source "lib/kunit/Kconfig"
1690
8d438288
AM
1691config NOTIFIER_ERROR_INJECTION
1692 tristate "Notifier error injection"
1693 depends on DEBUG_KERNEL
1694 select DEBUG_FS
1695 help
e41e85cc 1696 This option provides the ability to inject artificial errors to
8d438288
AM
1697 specified notifier chain callbacks. It is useful to test the error
1698 handling of notifier call chain failures.
1699
1700 Say N if unsure.
1701
048b9c35
AM
1702config PM_NOTIFIER_ERROR_INJECT
1703 tristate "PM notifier error injection module"
1704 depends on PM && NOTIFIER_ERROR_INJECTION
1705 default m if PM_DEBUG
1706 help
e41e85cc 1707 This option provides the ability to inject artificial errors to
048b9c35
AM
1708 PM notifier chain callbacks. It is controlled through debugfs
1709 interface /sys/kernel/debug/notifier-error-inject/pm
1710
1711 If the notifier call chain should be failed with some events
1712 notified, write the error code to "actions/<notifier event>/error".
1713
1714 Example: Inject PM suspend error (-12 = -ENOMEM)
1715
1716 # cd /sys/kernel/debug/notifier-error-inject/pm/
1717 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1718 # echo mem > /sys/power/state
1719 bash: echo: write error: Cannot allocate memory
1720
1721 To compile this code as a module, choose M here: the module will
1722 be called pm-notifier-error-inject.
1723
1724 If unsure, say N.
1725
d526e85f
BH
1726config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1727 tristate "OF reconfig notifier error injection module"
1728 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1729 help
e41e85cc 1730 This option provides the ability to inject artificial errors to
d526e85f 1731 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1732 through debugfs interface under
d526e85f 1733 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1734
1735 If the notifier call chain should be failed with some events
1736 notified, write the error code to "actions/<notifier event>/error".
1737
1738 To compile this code as a module, choose M here: the module will
e12a95f4 1739 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1740
1741 If unsure, say N.
1742
02fff96a
NA
1743config NETDEV_NOTIFIER_ERROR_INJECT
1744 tristate "Netdev notifier error injection module"
1745 depends on NET && NOTIFIER_ERROR_INJECTION
1746 help
1747 This option provides the ability to inject artificial errors to
1748 netdevice notifier chain callbacks. It is controlled through debugfs
1749 interface /sys/kernel/debug/notifier-error-inject/netdev
1750
1751 If the notifier call chain should be failed with some events
1752 notified, write the error code to "actions/<notifier event>/error".
1753
1754 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1755
1756 # cd /sys/kernel/debug/notifier-error-inject/netdev
1757 # echo -22 > actions/NETDEV_CHANGEMTU/error
1758 # ip link set eth0 mtu 1024
1759 RTNETLINK answers: Invalid argument
1760
1761 To compile this code as a module, choose M here: the module will
1762 be called netdev-notifier-error-inject.
1763
1764 If unsure, say N.
1765
f1b4bd06
MP
1766config FUNCTION_ERROR_INJECTION
1767 def_bool y
1768 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1769
6ff1cb35 1770config FAULT_INJECTION
1ab8509a
AM
1771 bool "Fault-injection framework"
1772 depends on DEBUG_KERNEL
329409ae
AM
1773 help
1774 Provide fault-injection framework.
1775 For more details, see Documentation/fault-injection/.
6ff1cb35 1776
8a8b6502 1777config FAILSLAB
1ab8509a
AM
1778 bool "Fault-injection capability for kmalloc"
1779 depends on FAULT_INJECTION
773ff60e 1780 depends on SLAB || SLUB
8a8b6502 1781 help
1ab8509a 1782 Provide fault-injection capability for kmalloc.
8a8b6502 1783
933e312e 1784config FAIL_PAGE_ALLOC
29b46fa3 1785 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1786 depends on FAULT_INJECTION
933e312e 1787 help
1ab8509a 1788 Provide fault-injection capability for alloc_pages().
933e312e 1789
2c739ced
AL
1790config FAULT_INJECTION_USERCOPY
1791 bool "Fault injection capability for usercopy functions"
1792 depends on FAULT_INJECTION
1793 help
1794 Provides fault-injection capability to inject failures
1795 in usercopy functions (copy_from_user(), get_user(), ...).
1796
c17bb495 1797config FAIL_MAKE_REQUEST
86327d19 1798 bool "Fault-injection capability for disk IO"
581d4e28 1799 depends on FAULT_INJECTION && BLOCK
c17bb495 1800 help
1ab8509a 1801 Provide fault-injection capability for disk IO.
c17bb495 1802
581d4e28 1803config FAIL_IO_TIMEOUT
f4d01439 1804 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1805 depends on FAULT_INJECTION && BLOCK
1806 help
1807 Provide fault-injection capability on end IO handling. This
1808 will make the block layer "forget" an interrupt as configured,
1809 thus exercising the error handling.
1810
1811 Only works with drivers that use the generic timeout handling,
1812 for others it wont do anything.
1813
ab51fbab
DB
1814config FAIL_FUTEX
1815 bool "Fault-injection capability for futexes"
1816 select DEBUG_FS
1817 depends on FAULT_INJECTION && FUTEX
1818 help
1819 Provide fault-injection capability for futexes.
1820
f1b4bd06
MP
1821config FAULT_INJECTION_DEBUG_FS
1822 bool "Debugfs entries for fault-injection capabilities"
1823 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1824 help
1825 Enable configuration of fault-injection capabilities via debugfs.
1826
4b1a29a7
MH
1827config FAIL_FUNCTION
1828 bool "Fault-injection capability for functions"
1829 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1830 help
1831 Provide function-based fault-injection capability.
1832 This will allow you to override a specific function with a return
1833 with given return value. As a result, function caller will see
1834 an error value and have to handle it. This is useful to test the
1835 error handling in various subsystems.
1836
f1b4bd06
MP
1837config FAIL_MMC_REQUEST
1838 bool "Fault-injection capability for MMC IO"
1839 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1840 help
f1b4bd06
MP
1841 Provide fault-injection capability for MMC IO.
1842 This will make the mmc core return data errors. This is
1843 useful to test the error handling in the mmc block device
1844 and to test how the mmc host driver handles retries from
1845 the block device.
1df49008
AM
1846
1847config FAULT_INJECTION_STACKTRACE_FILTER
1848 bool "stacktrace filter for fault-injection capabilities"
1849 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 1850 depends on !X86_64
1df49008 1851 select STACKTRACE
f9b58e8c 1852 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1df49008
AM
1853 help
1854 Provide stacktrace filter for fault-injection capabilities
267c4025 1855
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CD
1856config ARCH_HAS_KCOV
1857 bool
cc3fa840 1858 help
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CD
1859 An architecture should select this when it can successfully
1860 build and run with CONFIG_KCOV. This typically requires
1861 disabling instrumentation for some early boot code.
cc3fa840 1862
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1863config CC_HAS_SANCOV_TRACE_PC
1864 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 1865
cc3fa840 1866
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1867config KCOV
1868 bool "Code coverage for fuzzing"
1869 depends on ARCH_HAS_KCOV
1870 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1871 select DEBUG_FS
1872 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1873 help
1874 KCOV exposes kernel code coverage information in a form suitable
1875 for coverage-guided fuzzing (randomized testing).
cc3fa840 1876
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CD
1877 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1878 different machines and across reboots. If you need stable PC values,
1879 disable RANDOMIZE_BASE.
cc3fa840 1880
09a74952 1881 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 1882
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1883config KCOV_ENABLE_COMPARISONS
1884 bool "Enable comparison operands collection by KCOV"
1885 depends on KCOV
1886 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1887 help
1888 KCOV also exposes operands of every comparison in the instrumented
1889 code along with operand sizes and PCs of the comparison instructions.
1890 These operands can be used by fuzzing engines to improve the quality
1891 of fuzzing coverage.
cc3fa840 1892
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1893config KCOV_INSTRUMENT_ALL
1894 bool "Instrument all code by default"
1895 depends on KCOV
1896 default y
1897 help
1898 If you are doing generic system call fuzzing (like e.g. syzkaller),
1899 then you will want to instrument the whole kernel and you should
1900 say y here. If you are doing more targeted fuzzing (like e.g.
1901 filesystem fuzzing with AFL) then you will want to enable coverage
1902 for more specific subsets of files, and should say n here.
84bc809e 1903
5ff3b30a
AK
1904config KCOV_IRQ_AREA_SIZE
1905 hex "Size of interrupt coverage collection area in words"
1906 depends on KCOV
1907 default 0x40000
1908 help
1909 KCOV uses preallocated per-cpu areas to collect coverage from
1910 soft interrupts. This specifies the size of those areas in the
1911 number of unsigned long words.
1912
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VL
1913menuconfig RUNTIME_TESTING_MENU
1914 bool "Runtime Testing"
908009e8 1915 def_bool y
d3deafaa
VL
1916
1917if RUNTIME_TESTING_MENU
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DH
1918
1919config LKDTM
1920 tristate "Linux Kernel Dump Test Tool Module"
1921 depends on DEBUG_FS
881c5149
DH
1922 help
1923 This module enables testing of the different dumping mechanisms by
1924 inducing system failures at predefined crash points.
1925 If you don't need it: say N
1926 Choose M here to compile this code as a module. The module will be
1927 called lkdtm.
1928
1929 Documentation on how to use the module can be found in
10ffebbe 1930 Documentation/fault-injection/provoke-crashes.rst
881c5149
DH
1931
1932config TEST_LIST_SORT
e327fd7c
GU
1933 tristate "Linked list sorting test"
1934 depends on DEBUG_KERNEL || m
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DH
1935 help
1936 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
1937 executed only once during system boot (so affects only boot time),
1938 or at module load time.
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DH
1939
1940 If unsure, say N.
1941
6e24628d
IR
1942config TEST_MIN_HEAP
1943 tristate "Min heap test"
1944 depends on DEBUG_KERNEL || m
1945 help
1946 Enable this to turn on min heap function tests. This test is
1947 executed only once during system boot (so affects only boot time),
1948 or at module load time.
1949
1950 If unsure, say N.
1951
c5adae95 1952config TEST_SORT
5c4e6798
GU
1953 tristate "Array-based sort test"
1954 depends on DEBUG_KERNEL || m
c5adae95 1955 help
5c4e6798
GU
1956 This option enables the self-test function of 'sort()' at boot,
1957 or at module load time.
c5adae95
KF
1958
1959 If unsure, say N.
1960
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1961config KPROBES_SANITY_TEST
1962 bool "Kprobes sanity tests"
1963 depends on DEBUG_KERNEL
1964 depends on KPROBES
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DH
1965 help
1966 This option provides for testing basic kprobes functionality on
5a6cf77f 1967 boot. Samples of kprobe and kretprobe are inserted and
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DH
1968 verified for functionality.
1969
1970 Say N if you are unsure.
1971
1972config BACKTRACE_SELF_TEST
1973 tristate "Self test for the backtrace code"
1974 depends on DEBUG_KERNEL
881c5149
DH
1975 help
1976 This option provides a kernel module that can be used to test
1977 the kernel stack backtrace code. This option is not useful
1978 for distributions or general kernels, but only for kernel
1979 developers working on architecture code.
1980
1981 Note that if you want to also test saved backtraces, you will
1982 have to enable STACKTRACE as well.
1983
1984 Say N if you are unsure.
1985
910a742d
ML
1986config RBTREE_TEST
1987 tristate "Red-Black tree test"
7c993e11 1988 depends on DEBUG_KERNEL
910a742d
ML
1989 help
1990 A benchmark measuring the performance of the rbtree library.
1991 Also includes rbtree invariant checks.
1992
4b4f3acc
FB
1993config REED_SOLOMON_TEST
1994 tristate "Reed-Solomon library test"
1995 depends on DEBUG_KERNEL || m
1996 select REED_SOLOMON
1997 select REED_SOLOMON_ENC16
1998 select REED_SOLOMON_DEC16
1999 help
2000 This option enables the self-test function of rslib at boot,
2001 or at module load time.
2002
2003 If unsure, say N.
2004
fff3fd8a
ML
2005config INTERVAL_TREE_TEST
2006 tristate "Interval tree test"
0f789b67 2007 depends on DEBUG_KERNEL
a88cc108 2008 select INTERVAL_TREE
fff3fd8a
ML
2009 help
2010 A benchmark measuring the performance of the interval tree library
2011
623fd807
GT
2012config PERCPU_TEST
2013 tristate "Per cpu operations test"
2014 depends on m && DEBUG_KERNEL
2015 help
2016 Enable this option to build test module which validates per-cpu
2017 operations.
2018
2019 If unsure, say N.
2020
881c5149 2021config ATOMIC64_SELFTEST
55ded955 2022 tristate "Perform an atomic64_t self-test"
881c5149 2023 help
55ded955
GU
2024 Enable this option to test the atomic64_t functions at boot or
2025 at module load time.
881c5149
DH
2026
2027 If unsure, say N.
2028
2029config ASYNC_RAID6_TEST
2030 tristate "Self test for hardware accelerated raid6 recovery"
2031 depends on ASYNC_RAID6_RECOV
2032 select ASYNC_MEMCPY
a7f7f624 2033 help
881c5149
DH
2034 This is a one-shot self test that permutes through the
2035 recovery of all the possible two disk failure scenarios for a
2036 N-disk array. Recovery is performed with the asynchronous
2037 raid6 recovery routines, and will optionally use an offload
2038 engine if one is available.
2039
2040 If unsure, say N.
2041
64d1d77a
AS
2042config TEST_HEXDUMP
2043 tristate "Test functions located in the hexdump module at runtime"
2044
881c5149
DH
2045config TEST_STRING_HELPERS
2046 tristate "Test functions located in the string_helpers module at runtime"
2047
0b0600c8
TH
2048config TEST_STRSCPY
2049 tristate "Test strscpy*() family of functions at runtime"
2050
881c5149
DH
2051config TEST_KSTRTOX
2052 tristate "Test kstrto*() family of functions at runtime"
2053
707cc728
RV
2054config TEST_PRINTF
2055 tristate "Test printf() family of functions at runtime"
2056
5fd003f5
DD
2057config TEST_BITMAP
2058 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
2059 help
2060 Enable this option to test the bitmap functions at boot.
2061
2062 If unsure, say N.
2063
cfaff0e5
AS
2064config TEST_UUID
2065 tristate "Test functions located in the uuid module at runtime"
2066
ad3d6c72
MW
2067config TEST_XARRAY
2068 tristate "Test the XArray code at runtime"
2069
455a35a6
RV
2070config TEST_OVERFLOW
2071 tristate "Test check_*_overflow() functions at runtime"
2072
7e1e7763 2073config TEST_RHASHTABLE
9d6dbe1b 2074 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2075 help
2076 Enable this option to test the rhashtable functions at boot.
2077
2078 If unsure, say N.
2079
468a9428
GS
2080config TEST_HASH
2081 tristate "Perform selftest on hash functions"
468a9428 2082 help
2c956a60
JD
2083 Enable this option to test the kernel's integer (<linux/hash.h>),
2084 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2085 hash functions on boot (or module load).
468a9428
GS
2086
2087 This is intended to help people writing architecture-specific
2088 optimized versions. If unsure, say N.
2089
8ab8ba38
MW
2090config TEST_IDA
2091 tristate "Perform selftest on IDA functions"
2092
44091d29
JP
2093config TEST_PARMAN
2094 tristate "Perform selftest on priority array manager"
44091d29
JP
2095 depends on PARMAN
2096 help
2097 Enable this option to test priority array manager on boot
2098 (or module load).
2099
2100 If unsure, say N.
2101
6aed82de
DL
2102config TEST_IRQ_TIMINGS
2103 bool "IRQ timings selftest"
2104 depends on IRQ_TIMINGS
2105 help
2106 Enable this option to test the irq timings code on boot.
2107
2108 If unsure, say N.
2109
8a6f0b47 2110config TEST_LKM
93e9ef83 2111 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2112 depends on m
2113 help
2114 This builds the "test_module" module that emits "Hello, world"
2115 on printk when loaded. It is designed to be used for basic
2116 evaluation of the module loading subsystem (for example when
2117 validating module verification). It lacks any extra dependencies,
2118 and will not normally be loaded by the system unless explicitly
2119 requested by name.
2120
2121 If unsure, say N.
2122
c348c163 2123config TEST_BITOPS
6af132f3 2124 tristate "Test module for compilation of bitops operations"
c348c163
JB
2125 depends on m
2126 help
2127 This builds the "test_bitops" module that is much like the
2128 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2129 set/clear_bit macros and get_count_order/long to make sure there are
2130 no compiler warnings from C=1 sparse checker or -Wextra
2131 compilations. It has no dependencies and doesn't run or load unless
2132 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2133
2134 If unsure, say N.
2135
3f21a6b7
URS
2136config TEST_VMALLOC
2137 tristate "Test module for stress/performance analysis of vmalloc allocator"
2138 default n
2139 depends on MMU
2140 depends on m
2141 help
2142 This builds the "test_vmalloc" module that should be used for
2143 stress and performance analysis. So, any new change for vmalloc
2144 subsystem can be evaluated from performance and stability point
2145 of view.
2146
2147 If unsure, say N.
2148
3e2a4c18
KC
2149config TEST_USER_COPY
2150 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2151 depends on m
2152 help
2153 This builds the "test_user_copy" module that runs sanity checks
2154 on the copy_to/from_user infrastructure, making sure basic
2155 user/kernel boundary testing is working. If it fails to load,
2156 a regression has been detected in the user/kernel memory boundary
2157 protections.
2158
2159 If unsure, say N.
2160
64a8946b
AS
2161config TEST_BPF
2162 tristate "Test BPF filter functionality"
98920ba6 2163 depends on m && NET
64a8946b
AS
2164 help
2165 This builds the "test_bpf" module that runs various test vectors
2166 against the BPF interpreter or BPF JIT compiler depending on the
2167 current setting. This is in particular useful for BPF JIT compiler
2168 development, but also to run regression tests against changes in
3c731eba
AS
2169 the interpreter code. It also enables test stubs for eBPF maps and
2170 verifier used by user space verifier testsuite.
64a8946b
AS
2171
2172 If unsure, say N.
2173
509e56b3
MB
2174config TEST_BLACKHOLE_DEV
2175 tristate "Test blackhole netdev functionality"
2176 depends on m && NET
2177 help
2178 This builds the "test_blackhole_dev" module that validates the
2179 data path through this blackhole netdev.
2180
2181 If unsure, say N.
2182
dceeb3e7 2183config FIND_BIT_BENCHMARK
4441fca0 2184 tristate "Test find_bit functions"
4441fca0
YN
2185 help
2186 This builds the "test_find_bit" module that measure find_*_bit()
2187 functions performance.
2188
2189 If unsure, say N.
2190
0a8adf58
KC
2191config TEST_FIRMWARE
2192 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2193 depends on FW_LOADER
2194 help
2195 This builds the "test_firmware" module that creates a userspace
2196 interface for testing firmware loading. This can be used to
2197 control the triggering of firmware loading without needing an
2198 actual firmware-using device. The contents can be rechecked by
2199 userspace.
2200
2201 If unsure, say N.
2202
9308f2f9
LR
2203config TEST_SYSCTL
2204 tristate "sysctl test driver"
9308f2f9
LR
2205 depends on PROC_SYSCTL
2206 help
2207 This builds the "test_sysctl" module. This driver enables to test the
2208 proc sysctl interfaces available to drivers safely without affecting
2209 production knobs which might alter system functionality.
2210
2211 If unsure, say N.
2212
d2585f51
VMI
2213config BITFIELD_KUNIT
2214 tristate "KUnit test bitfield functions at runtime"
2215 depends on KUNIT
2216 help
2217 Enable this option to test the bitfield functions at boot.
2218
2219 KUnit tests run during boot and output the results to the debug log
2220 in TAP format (http://testanything.org/). Only useful for kernel devs
2221 running the KUnit test harness, and not intended for inclusion into a
2222 production build.
2223
2224 For more information on KUnit and unit tests in general please refer
2225 to the KUnit documentation in Documentation/dev-tools/kunit/.
2226
2227 If unsure, say N.
2228
2cb80dbb 2229config SYSCTL_KUNIT_TEST
5f215aab 2230 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2231 depends on KUNIT
5f215aab 2232 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2233 help
2234 This builds the proc sysctl unit test, which runs on boot.
2235 Tests the API contract and implementation correctness of sysctl.
2236 For more information on KUnit and unit tests in general please refer
2237 to the KUnit documentation in Documentation/dev-tools/kunit/.
2238
2239 If unsure, say N.
2240
ea2dd7c0 2241config LIST_KUNIT_TEST
5f215aab 2242 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2243 depends on KUNIT
5f215aab 2244 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2245 help
2246 This builds the linked list KUnit test suite.
2247 It tests that the API and basic functionality of the list_head type
2248 and associated macros.
2249
2250 KUnit tests run during boot and output the results to the debug log
d89775fc 2251 in TAP format (https://testanything.org/). Only useful for kernel devs
ea2dd7c0
DG
2252 running the KUnit test harness, and not intended for inclusion into a
2253 production build.
2254
2255 For more information on KUnit and unit tests in general please refer
2256 to the KUnit documentation in Documentation/dev-tools/kunit/.
2257
2258 If unsure, say N.
2259
33d599f0
MV
2260config LINEAR_RANGES_TEST
2261 tristate "KUnit test for linear_ranges"
2262 depends on KUNIT
2263 select LINEAR_RANGES
2264 help
2265 This builds the linear_ranges unit test, which runs on boot.
2266 Tests the linear_ranges logic correctness.
2267 For more information on KUnit and unit tests in general please refer
2268 to the KUnit documentation in Documentation/dev-tools/kunit/.
2269
2270 If unsure, say N.
2271
6d511020
RF
2272config BITS_TEST
2273 tristate "KUnit test for bits.h"
2274 depends on KUNIT
2275 help
2276 This builds the bits unit test.
2277 Tests the logic of macros defined in bits.h.
2278 For more information on KUnit and unit tests in general please refer
2279 to the KUnit documentation in Documentation/dev-tools/kunit/.
2280
2281 If unsure, say N.
2282
e704f93a
DR
2283config TEST_UDELAY
2284 tristate "udelay test driver"
e704f93a
DR
2285 help
2286 This builds the "udelay_test" module that helps to make sure
2287 that udelay() is working properly.
2288
2289 If unsure, say N.
2290
2bf9e0ab
IM
2291config TEST_STATIC_KEYS
2292 tristate "Test static keys"
579e1acb
JB
2293 depends on m
2294 help
2bf9e0ab 2295 Test the static key interfaces.
579e1acb
JB
2296
2297 If unsure, say N.
2298
d9c6a72d
LR
2299config TEST_KMOD
2300 tristate "kmod stress tester"
d9c6a72d 2301 depends on m
d9c6a72d 2302 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2303 depends on BLOCK
d9c6a72d
LR
2304 select TEST_LKM
2305 select XFS_FS
2306 select TUN
2307 select BTRFS_FS
2308 help
2309 Test the kernel's module loading mechanism: kmod. kmod implements
2310 support to load modules using the Linux kernel's usermode helper.
2311 This test provides a series of tests against kmod.
2312
2313 Although technically you can either build test_kmod as a module or
2314 into the kernel we disallow building it into the kernel since
2315 it stress tests request_module() and this will very likely cause
2316 some issues by taking over precious threads available from other
2317 module load requests, ultimately this could be fatal.
2318
2319 To run tests run:
2320
2321 tools/testing/selftests/kmod/kmod.sh --help
2322
2323 If unsure, say N.
2324
e4dace36
FF
2325config TEST_DEBUG_VIRTUAL
2326 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2327 depends on DEBUG_VIRTUAL
2328 help
2329 Test the kernel's ability to detect incorrect calls to
2330 virt_to_phys() done against the non-linear part of the
2331 kernel's virtual address map.
2332
2333 If unsure, say N.
2334
ce76d938
AS
2335config TEST_MEMCAT_P
2336 tristate "Test memcat_p() helper function"
2337 help
2338 Test the memcat_p() helper for correctly merging two
2339 pointer arrays together.
2340
2341 If unsure, say N.
2342
a2818ee4
JL
2343config TEST_LIVEPATCH
2344 tristate "Test livepatching"
2345 default n
bae05437 2346 depends on DYNAMIC_DEBUG
a2818ee4
JL
2347 depends on LIVEPATCH
2348 depends on m
2349 help
2350 Test kernel livepatching features for correctness. The tests will
2351 load test modules that will be livepatched in various scenarios.
2352
2353 To run all the livepatching tests:
2354
2355 make -C tools/testing/selftests TARGETS=livepatch run_tests
2356
2357 Alternatively, individual tests may be invoked:
2358
2359 tools/testing/selftests/livepatch/test-callbacks.sh
2360 tools/testing/selftests/livepatch/test-livepatch.sh
2361 tools/testing/selftests/livepatch/test-shadow-vars.sh
2362
2363 If unsure, say N.
2364
0a020d41
JP
2365config TEST_OBJAGG
2366 tristate "Perform selftest on object aggreration manager"
2367 default n
2368 depends on OBJAGG
2369 help
2370 Enable this option to test object aggregation manager on boot
2371 (or module load).
2372
0a020d41 2373
50ceaa95
KC
2374config TEST_STACKINIT
2375 tristate "Test level of stack variable initialization"
2376 help
2377 Test if the kernel is zero-initializing stack variables and
2378 padding. Coverage is controlled by compiler flags,
2379 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2380 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2381
2382 If unsure, say N.
2383
5015a300
AP
2384config TEST_MEMINIT
2385 tristate "Test heap/page initialization"
2386 help
2387 Test if the kernel is zero-initializing heap and page allocations.
2388 This can be useful to test init_on_alloc and init_on_free features.
2389
2390 If unsure, say N.
2391
b2ef9f5a
RC
2392config TEST_HMM
2393 tristate "Test HMM (Heterogeneous Memory Management)"
2394 depends on TRANSPARENT_HUGEPAGE
2395 depends on DEVICE_PRIVATE
2396 select HMM_MIRROR
2397 select MMU_NOTIFIER
2398 help
2399 This is a pseudo device driver solely for testing HMM.
2400 Say M here if you want to build the HMM test module.
2401 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2402
2403 If unsure, say N.
2404
e320d301
MWO
2405config TEST_FREE_PAGES
2406 tristate "Test freeing pages"
2407 help
2408 Test that a memory leak does not occur due to a race between
2409 freeing a block of pages and a speculative page reference.
2410 Loading this module is safe if your kernel has the bug fixed.
2411 If the bug is not fixed, it will leak gigabytes of memory and
2412 probably OOM your system.
2413
4185b3b9
PA
2414config TEST_FPU
2415 tristate "Test floating point operations in kernel space"
2416 depends on X86 && !KCOV_INSTRUMENT_ALL
2417 help
2418 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2419 which will trigger a sequence of floating point operations. This is used
2420 for self-testing floating point control register setting in
2421 kernel_fpu_begin().
2422
2423 If unsure, say N.
2424
d3deafaa 2425endif # RUNTIME_TESTING_MENU
cc3fa840
RD
2426
2427config MEMTEST
2428 bool "Memtest"
a7f7f624 2429 help
cc3fa840
RD
2430 This option adds a kernel parameter 'memtest', which allows memtest
2431 to be set.
2432 memtest=0, mean disabled; -- default
2433 memtest=1, mean do 1 test pattern;
2434 ...
2435 memtest=17, mean do 17 test patterns.
2436 If you are unsure how to answer this question, answer N.
2437
21266be9 2438
06ec64b8 2439
af9ca6f9
BB
2440config HYPERV_TESTING
2441 bool "Microsoft Hyper-V driver testing"
2442 default n
2443 depends on HYPERV && DEBUG_FS
2444 help
2445 Select this option to enable Hyper-V vmbus testing.
2446
045f6d79
CD
2447endmenu # "Kernel Testing and Coverage"
2448
06ec64b8 2449endmenu # Kernel hacking