x86/entry: Fix NMI vs IRQ state tracking
[linux-2.6-block.git] / lib / Kconfig.debug
CommitLineData
ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
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21config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
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38config CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
40 range 1 15
41 default "7"
42 help
43 Default loglevel to determine what will be printed on the console.
44
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
48
50f4d9bd 49 Note: This does not affect the log level of un-prefixed printk()
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50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
51 option.
52
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53config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
55 range 1 15
56 default "4"
57 help
58 loglevel to use when "quiet" is passed on the kernel commandline.
59
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
63
42a9dc0b 64config MESSAGE_LOGLEVEL_DEFAULT
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65 int "Default message log level (1-7)"
66 range 1 7
67 default "4"
68 help
69 Default log level for printk statements with no specified priority.
70
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
73 priority.
74
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75 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
78
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79config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
82 help
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
86 using "boot_delay=N".
87
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
96
97config DYNAMIC_DEBUG
98 bool "Enable dynamic printk() support"
99 default n
100 depends on PRINTK
239a5791 101 depends on (DEBUG_FS || PROC_FS)
ceabef7d 102 select DYNAMIC_DEBUG_CORE
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103 help
104
105 Compiles debug level messages into the kernel, which would not
106 otherwise be available at runtime. These messages can then be
107 enabled/disabled based on various levels of scope - per source file,
108 function, module, format string, and line number. This mechanism
109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
110 enlarges the kernel text size by about 2%.
111
112 If a source file is compiled with DEBUG flag set, any
113 pr_debug() calls in it are enabled by default, but can be
114 disabled at runtime as below. Note that DEBUG flag is
115 turned on by many CONFIG_*DEBUG* options.
116
117 Usage:
118
119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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120 which is contained in the 'debugfs' filesystem or procfs.
121 Thus, the debugfs or procfs filesystem must first be mounted before
122 making use of this feature.
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123 We refer the control file as: <debugfs>/dynamic_debug/control. This
124 file contains a list of the debug statements that can be enabled. The
125 format for each line of the file is:
126
127 filename:lineno [module]function flags format
128
129 filename : source file of the debug statement
130 lineno : line number of the debug statement
131 module : module that contains the debug statement
132 function : function that contains the debug statement
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133 flags : '=p' means the line is turned 'on' for printing
134 format : the format used for the debug statement
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135
136 From a live system:
137
138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
139 # filename:lineno [module]function flags format
140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
143
144 Example usage:
145
146 // enable the message at line 1603 of file svcsock.c
147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
148 <debugfs>/dynamic_debug/control
149
150 // enable all the messages in file svcsock.c
151 nullarbor:~ # echo -n 'file svcsock.c +p' >
152 <debugfs>/dynamic_debug/control
153
154 // enable all the messages in the NFS server module
155 nullarbor:~ # echo -n 'module nfsd +p' >
156 <debugfs>/dynamic_debug/control
157
158 // enable all 12 messages in the function svc_process()
159 nullarbor:~ # echo -n 'func svc_process +p' >
160 <debugfs>/dynamic_debug/control
161
162 // disable all 12 messages in the function svc_process()
163 nullarbor:~ # echo -n 'func svc_process -p' >
164 <debugfs>/dynamic_debug/control
165
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166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
167 information.
604ff0dc 168
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169config DYNAMIC_DEBUG_CORE
170 bool "Enable core function of dynamic debug support"
171 depends on PRINTK
172 depends on (DEBUG_FS || PROC_FS)
173 help
174 Enable core functional support of dynamic debug. It is useful
175 when you want to tie dynamic debug to your kernel modules with
176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
177 the case of embedded system where the kernel image size is
178 sensitive for people.
179
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180config SYMBOLIC_ERRNAME
181 bool "Support symbolic error names in printf"
182 default y if PRINTK
183 help
184 If you say Y here, the kernel's printf implementation will
185 be able to print symbolic error names such as ENOSPC instead
186 of the number 28. It makes the kernel image slightly larger
187 (about 3KB), but can make the kernel logs easier to read.
188
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189config DEBUG_BUGVERBOSE
190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
192 default y
193 help
194 Say Y here to make BUG() panics output the file name and line number
195 of the BUG call as well as the EIP and oops trace. This aids
196 debugging but costs about 70-100K of memory.
197
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198endmenu # "printk and dmesg options"
199
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200menu "Compile-time checks and compiler options"
201
202config DEBUG_INFO
203 bool "Compile the kernel with debug info"
12b13835 204 depends on DEBUG_KERNEL && !COMPILE_TEST
6dfc0665 205 help
68d4b3df 206 If you say Y here the resulting kernel image will include
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207 debugging info resulting in a larger kernel image.
208 This adds debug symbols to the kernel and modules (gcc -g), and
209 is needed if you intend to use kernel crashdump or binary object
210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
211 Say Y here only if you plan to debug the kernel.
212
213 If unsure, say N.
214
215config DEBUG_INFO_REDUCED
216 bool "Reduce debugging information"
217 depends on DEBUG_INFO
218 help
219 If you say Y here gcc is instructed to generate less debugging
220 information for structure types. This means that tools that
221 need full debugging information (like kgdb or systemtap) won't
222 be happy. But if you merely need debugging information to
223 resolve line numbers there is no loss. Advantage is that
224 build directory object sizes shrink dramatically over a full
225 DEBUG_INFO build and compile times are reduced too.
226 Only works with newer gcc versions.
227
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228config DEBUG_INFO_COMPRESSED
229 bool "Compressed debugging information"
230 depends on DEBUG_INFO
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"
a687a533 246 depends on DEBUG_INFO
9d937444 247 depends on $(cc-option,-gsplit-dwarf)
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248 help
249 Generate debug info into separate .dwo files. This significantly
250 reduces the build directory size for builds with DEBUG_INFO,
251 because it stores the information only once on disk in .dwo
252 files instead of multiple times in object files and executables.
253 In addition the debug information is also compressed.
254
255 Requires recent gcc (4.7+) and recent gdb/binutils.
256 Any tool that packages or reads debug information would need
257 to know about the .dwo files and include them.
258 Incompatible with older versions of ccache.
259
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260config DEBUG_INFO_DWARF4
261 bool "Generate dwarf4 debuginfo"
262 depends on DEBUG_INFO
9d937444 263 depends on $(cc-option,-gdwarf-4)
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264 help
265 Generate dwarf4 debug info. This requires recent versions
266 of gcc and gdb. It makes the debug information larger.
267 But it significantly improves the success of resolving
268 variables in gdb on optimized code.
269
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270config DEBUG_INFO_BTF
271 bool "Generate BTF typeinfo"
272 depends on DEBUG_INFO
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273 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
274 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
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275 help
276 Generate deduplicated BTF type information from DWARF debug info.
277 Turning this on expects presence of pahole tool, which will convert
278 DWARF type info into equivalent deduplicated BTF type info.
279
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280config GDB_SCRIPTS
281 bool "Provide GDB scripts for kernel debugging"
282 depends on DEBUG_INFO
283 help
284 This creates the required links to GDB helper scripts in the
285 build directory. If you load vmlinux into gdb, the helper
286 scripts will be automatically imported by gdb as well, and
287 additional functions are available to analyze a Linux kernel
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288 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
289 for further details.
3ee7b3fa 290
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291config ENABLE_MUST_CHECK
292 bool "Enable __must_check logic"
293 default y
294 help
295 Enable the __must_check logic in the kernel build. Disable this to
296 suppress the "warning: ignoring return value of 'foo', declared with
297 attribute warn_unused_result" messages.
1da177e4 298
35bb5b1e 299config FRAME_WARN
a83e4ca2 300 int "Warn for stack frames larger than"
35bb5b1e 301 range 0 8192
0e07f663 302 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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303 default 1280 if (!64BIT && PARISC)
304 default 1024 if (!64BIT && !PARISC)
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305 default 2048 if 64BIT
306 help
307 Tell gcc to warn at build time for stack frames larger than this.
308 Setting this too low will cause a lot of warnings.
309 Setting it to 0 disables the warning.
35bb5b1e 310
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311config STRIP_ASM_SYMS
312 bool "Strip assembler-generated symbols during link"
313 default n
314 help
315 Strip internal assembler-generated symbols during a link (symbols
316 that look like '.Lxxx') so they don't pollute the output of
317 get_wchan() and suchlike.
318
1873e870 319config READABLE_ASM
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320 bool "Generate readable assembler code"
321 depends on DEBUG_KERNEL
bf4735a4 322 help
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323 Disable some compiler optimizations that tend to generate human unreadable
324 assembler output. This may make the kernel slightly slower, but it helps
325 to keep kernel developers who have to stare a lot at assembler listings
326 sane.
bf4735a4 327
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328config HEADERS_INSTALL
329 bool "Install uapi headers to usr/include"
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330 depends on !UML
331 help
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332 This option will install uapi headers (headers exported to user-space)
333 into the usr/include directory for use during the kernel build.
334 This is unneeded for building the kernel itself, but needed for some
335 user-space program samples. It is also needed by some features such
336 as uapi header sanity checks.
337
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338config DEBUG_SECTION_MISMATCH
339 bool "Enable full Section mismatch analysis"
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340 help
341 The section mismatch analysis checks if there are illegal
342 references from one section to another section.
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343 During linktime or runtime, some sections are dropped;
344 any use of code/data previously in these sections would
91341d4b 345 most likely result in an oops.
e809ab01 346 In the code, functions and variables are annotated with
0db0628d 347 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 348 which results in the code/data being placed in specific sections.
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349 The section mismatch analysis is always performed after a full
350 kernel build, and enabling this option causes the following
b7dca6dd 351 additional step to occur:
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352 - Add the option -fno-inline-functions-called-once to gcc commands.
353 When inlining a function annotated with __init in a non-init
354 function, we would lose the section information and thus
91341d4b 355 the analysis would not catch the illegal reference.
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356 This option tells gcc to inline less (but it does result in
357 a larger kernel).
91341d4b 358
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359config SECTION_MISMATCH_WARN_ONLY
360 bool "Make section mismatch errors non-fatal"
361 default y
362 help
363 If you say N here, the build process will fail if there are any
364 section mismatch, instead of just throwing warnings.
365
366 If unsure, say Y.
367
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368#
369# Select this config option from the architecture Kconfig, if it
370# is preferred to always offer frame pointers as a config
371# option on the architecture (regardless of KERNEL_DEBUG):
372#
373config ARCH_WANT_FRAME_POINTERS
374 bool
f346f4b3 375
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376config FRAME_POINTER
377 bool "Compile the kernel with frame pointers"
a687a533 378 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 379 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 380 help
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381 If you say Y here the resulting kernel image will be slightly
382 larger and slower, but it gives very useful debugging information
383 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 384
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385config STACK_VALIDATION
386 bool "Compile-time stack metadata validation"
387 depends on HAVE_STACK_VALIDATION
388 default n
389 help
390 Add compile-time checks to validate stack metadata, including frame
391 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
392 that runtime stack traces are more reliable.
393
ee9f8fce 394 This is also a prerequisite for generation of ORC unwind data, which
11af8474 395 is needed for CONFIG_UNWINDER_ORC.
ee9f8fce 396
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397 For more information, see
398 tools/objtool/Documentation/stack-validation.txt.
399
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400config VMLINUX_VALIDATION
401 bool
402 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
403 default y
404
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405config DEBUG_FORCE_WEAK_PER_CPU
406 bool "Force weak per-cpu definitions"
407 depends on DEBUG_KERNEL
8446f1d3 408 help
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409 s390 and alpha require percpu variables in modules to be
410 defined weak to work around addressing range issue which
411 puts the following two restrictions on percpu variable
412 definitions.
8446f1d3 413
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414 1. percpu symbols must be unique whether static or not
415 2. percpu variables can't be defined inside a function
8446f1d3 416
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417 To ensure that generic code follows the above rules, this
418 option forces all percpu variables to be defined as weak.
5f329089 419
6dfc0665 420endmenu # "Compiler options"
8446f1d3 421
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422menu "Generic Kernel Debugging Instruments"
423
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424config MAGIC_SYSRQ
425 bool "Magic SysRq key"
426 depends on !UML
427 help
428 If you say Y here, you will have some control over the system even
429 if the system crashes for example during kernel debugging (e.g., you
430 will be able to flush the buffer cache to disk, reboot the system
431 immediately or dump some status information). This is accomplished
432 by pressing various keys while holding SysRq (Alt+PrintScreen). It
433 also works on a serial console (on PC hardware at least), if you
434 send a BREAK and then within 5 seconds a command keypress. The
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435 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
436 Don't say Y unless you really know what this hack does.
8446f1d3 437
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438config MAGIC_SYSRQ_DEFAULT_ENABLE
439 hex "Enable magic SysRq key functions by default"
440 depends on MAGIC_SYSRQ
441 default 0x1
442 help
443 Specifies which SysRq key functions are enabled by default.
444 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 445 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 446
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447config MAGIC_SYSRQ_SERIAL
448 bool "Enable magic SysRq key over serial"
449 depends on MAGIC_SYSRQ
450 default y
451 help
452 Many embedded boards have a disconnected TTL level serial which can
453 generate some garbage that can lead to spurious false sysrq detects.
454 This option allows you to decide whether you want to enable the
455 magic SysRq key.
456
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457config MAGIC_SYSRQ_SERIAL_SEQUENCE
458 string "Char sequence that enables magic SysRq over serial"
459 depends on MAGIC_SYSRQ_SERIAL
460 default ""
461 help
462 Specifies a sequence of characters that can follow BREAK to enable
463 SysRq on a serial console.
464
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465 If unsure, leave an empty string and the option will not be enabled.
466
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467config DEBUG_FS
468 bool "Debug Filesystem"
469 help
470 debugfs is a virtual file system that kernel developers use to put
471 debugging files into. Enable this option to be able to read and
472 write to these files.
473
474 For detailed documentation on the debugfs API, see
475 Documentation/filesystems/.
476
477 If unsure, say N.
478
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479source "lib/Kconfig.kgdb"
480
481source "lib/Kconfig.ubsan"
482
483endmenu
484
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485config DEBUG_KERNEL
486 bool "Kernel debugging"
fef2c9bc 487 help
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488 Say Y here if you are developing drivers or trying to debug and
489 identify kernel problems.
fef2c9bc 490
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491config DEBUG_MISC
492 bool "Miscellaneous debug code"
493 default DEBUG_KERNEL
494 depends on DEBUG_KERNEL
495 help
496 Say Y here if you need to enable miscellaneous debug code that should
497 be under a more specific debug option but isn't.
498
499
0610c8a8 500menu "Memory Debugging"
fef2c9bc 501
8636a1f9 502source "mm/Kconfig.debug"
fef2c9bc 503
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504config DEBUG_OBJECTS
505 bool "Debug object operations"
506 depends on DEBUG_KERNEL
9c44bc03 507 help
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508 If you say Y here, additional code will be inserted into the
509 kernel to track the life time of various objects and validate
510 the operations on those objects.
9c44bc03 511
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512config DEBUG_OBJECTS_SELFTEST
513 bool "Debug objects selftest"
514 depends on DEBUG_OBJECTS
515 help
516 This enables the selftest of the object debug code.
9c44bc03 517
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518config DEBUG_OBJECTS_FREE
519 bool "Debug objects in freed memory"
520 depends on DEBUG_OBJECTS
521 help
522 This enables checks whether a k/v free operation frees an area
523 which contains an object which has not been deactivated
524 properly. This can make kmalloc/kfree-intensive workloads
525 much slower.
3ac7fe5a 526
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527config DEBUG_OBJECTS_TIMERS
528 bool "Debug timer objects"
529 depends on DEBUG_OBJECTS
530 help
531 If you say Y here, additional code will be inserted into the
532 timer routines to track the life time of timer objects and
533 validate the timer operations.
534
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535config DEBUG_OBJECTS_WORK
536 bool "Debug work objects"
537 depends on DEBUG_OBJECTS
538 help
539 If you say Y here, additional code will be inserted into the
540 work queue routines to track the life time of work objects and
541 validate the work operations.
542
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543config DEBUG_OBJECTS_RCU_HEAD
544 bool "Debug RCU callbacks objects"
fc2ecf7e 545 depends on DEBUG_OBJECTS
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546 help
547 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
548
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549config DEBUG_OBJECTS_PERCPU_COUNTER
550 bool "Debug percpu counter objects"
551 depends on DEBUG_OBJECTS
552 help
553 If you say Y here, additional code will be inserted into the
554 percpu counter routines to track the life time of percpu counter
555 objects and validate the percpu counter operations.
556
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557config DEBUG_OBJECTS_ENABLE_DEFAULT
558 int "debug_objects bootup default value (0-1)"
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559 range 0 1
560 default "1"
561 depends on DEBUG_OBJECTS
562 help
563 Debug objects boot parameter default value
3ae70205 564
1da177e4 565config DEBUG_SLAB
4a2f0acf 566 bool "Debug slab memory allocations"
4675ff05 567 depends on DEBUG_KERNEL && SLAB
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568 help
569 Say Y here to have the kernel do limited verification on memory
570 allocation as well as poisoning memory on free to catch use of freed
571 memory. This can make kmalloc/kfree-intensive workloads much slower.
572
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573config SLUB_DEBUG_ON
574 bool "SLUB debugging on by default"
4675ff05 575 depends on SLUB && SLUB_DEBUG
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576 default n
577 help
578 Boot with debugging on by default. SLUB boots by default with
579 the runtime debug capabilities switched off. Enabling this is
580 equivalent to specifying the "slub_debug" parameter on boot.
581 There is no support for more fine grained debug control like
582 possible with slub_debug=xxx. SLUB debugging may be switched
583 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
584 "slub_debug=-".
585
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586config SLUB_STATS
587 default n
588 bool "Enable SLUB performance statistics"
ab4d5ed5 589 depends on SLUB && SYSFS
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590 help
591 SLUB statistics are useful to debug SLUBs allocation behavior in
592 order find ways to optimize the allocator. This should never be
593 enabled for production use since keeping statistics slows down
594 the allocator by a few percentage points. The slabinfo command
595 supports the determination of the most active slabs to figure
596 out which slabs are relevant to a particular load.
597 Try running: slabinfo -DA
598
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599config HAVE_DEBUG_KMEMLEAK
600 bool
601
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602config DEBUG_KMEMLEAK
603 bool "Kernel memory leak detector"
525c1f92 604 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 605 select DEBUG_FS
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606 select STACKTRACE if STACKTRACE_SUPPORT
607 select KALLSYMS
b60e26a2 608 select CRC32
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609 help
610 Say Y here if you want to enable the memory leak
611 detector. The memory allocation/freeing is traced in a way
612 similar to the Boehm's conservative garbage collector, the
613 difference being that the orphan objects are not freed but
614 only shown in /sys/kernel/debug/kmemleak. Enabling this
615 feature will introduce an overhead to memory
700199b0 616 allocations. See Documentation/dev-tools/kmemleak.rst for more
3bba00d7
CM
617 details.
618
0610c8a8
DH
619 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
620 of finding leaks due to the slab objects poisoning.
621
622 In order to access the kmemleak file, debugfs needs to be
623 mounted (usually at /sys/kernel/debug).
624
c5665868
CM
625config DEBUG_KMEMLEAK_MEM_POOL_SIZE
626 int "Kmemleak memory pool size"
0610c8a8 627 depends on DEBUG_KMEMLEAK
c59180ae 628 range 200 1000000
b751c52b 629 default 16000
0610c8a8
DH
630 help
631 Kmemleak must track all the memory allocations to avoid
632 reporting false positives. Since memory may be allocated or
c5665868
CM
633 freed before kmemleak is fully initialised, use a static pool
634 of metadata objects to track such callbacks. After kmemleak is
635 fully initialised, this memory pool acts as an emergency one
636 if slab allocations fail.
0610c8a8
DH
637
638config DEBUG_KMEMLEAK_TEST
639 tristate "Simple test for the kernel memory leak detector"
640 depends on DEBUG_KMEMLEAK && m
641 help
642 This option enables a module that explicitly leaks memory.
643
644 If unsure, say N.
645
646config DEBUG_KMEMLEAK_DEFAULT_OFF
647 bool "Default kmemleak to off"
648 depends on DEBUG_KMEMLEAK
649 help
650 Say Y here to disable kmemleak by default. It can then be enabled
651 on the command line via kmemleak=on.
652
d53ce042
SK
653config DEBUG_KMEMLEAK_AUTO_SCAN
654 bool "Enable kmemleak auto scan thread on boot up"
655 default y
656 depends on DEBUG_KMEMLEAK
657 help
658 Depending on the cpu, kmemleak scan may be cpu intensive and can
659 stall user tasks at times. This option enables/disables automatic
660 kmemleak scan at boot up.
661
662 Say N here to disable kmemleak auto scan thread to stop automatic
663 scanning. Disabling this option disables automatic reporting of
664 memory leaks.
665
666 If unsure, say Y.
667
0610c8a8
DH
668config DEBUG_STACK_USAGE
669 bool "Stack utilization instrumentation"
6c31da34 670 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
671 help
672 Enables the display of the minimum amount of free stack which each
673 task has ever had available in the sysrq-T and sysrq-P debug output.
674
675 This option will slow down process creation somewhat.
676
dc9b9638
CD
677config SCHED_STACK_END_CHECK
678 bool "Detect stack corruption on calls to schedule()"
679 depends on DEBUG_KERNEL
680 default n
681 help
682 This option checks for a stack overrun on calls to schedule().
683 If the stack end location is found to be over written always panic as
684 the content of the corrupted region can no longer be trusted.
685 This is to ensure no erroneous behaviour occurs which could result in
686 data corruption or a sporadic crash at a later stage once the region
687 is examined. The runtime overhead introduced is minimal.
688
399145f9
AK
689config ARCH_HAS_DEBUG_VM_PGTABLE
690 bool
691 help
692 An architecture should select this when it can successfully
693 build and run DEBUG_VM_PGTABLE.
694
0610c8a8
DH
695config DEBUG_VM
696 bool "Debug VM"
697 depends on DEBUG_KERNEL
698 help
699 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 700 that may impact performance.
0610c8a8
DH
701
702 If unsure, say N.
703
4f115147
DB
704config DEBUG_VM_VMACACHE
705 bool "Debug VMA caching"
706 depends on DEBUG_VM
707 help
708 Enable this to turn on VMA caching debug information. Doing so
709 can cause significant overhead, so only enable it in non-production
710 environments.
711
712 If unsure, say N.
713
0610c8a8
DH
714config DEBUG_VM_RB
715 bool "Debug VM red-black trees"
716 depends on DEBUG_VM
717 help
a663dad6 718 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
719
720 If unsure, say N.
721
95ad9755
KS
722config DEBUG_VM_PGFLAGS
723 bool "Debug page-flags operations"
724 depends on DEBUG_VM
725 help
726 Enables extra validation on page flags operations.
727
728 If unsure, say N.
729
399145f9
AK
730config DEBUG_VM_PGTABLE
731 bool "Debug arch page table for semantics compliance"
732 depends on MMU
733 depends on ARCH_HAS_DEBUG_VM_PGTABLE
734 default y if DEBUG_VM
735 help
736 This option provides a debug method which can be used to test
737 architecture page table helper functions on various platforms in
738 verifying if they comply with expected generic MM semantics. This
739 will help architecture code in making sure that any changes or
740 new additions of these helpers still conform to expected
741 semantics of the generic MM. Platforms will have to opt in for
742 this through ARCH_HAS_DEBUG_VM_PGTABLE.
743
744 If unsure, say N.
745
fa5b6ec9
LA
746config ARCH_HAS_DEBUG_VIRTUAL
747 bool
748
0610c8a8
DH
749config DEBUG_VIRTUAL
750 bool "Debug VM translations"
fa5b6ec9 751 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
752 help
753 Enable some costly sanity checks in virtual to page code. This can
754 catch mistakes with virt_to_page() and friends.
755
756 If unsure, say N.
757
758config DEBUG_NOMMU_REGIONS
759 bool "Debug the global anon/private NOMMU mapping region tree"
760 depends on DEBUG_KERNEL && !MMU
761 help
762 This option causes the global tree of anonymous and private mapping
763 regions to be regularly checked for invalid topology.
764
765config DEBUG_MEMORY_INIT
766 bool "Debug memory initialisation" if EXPERT
767 default !EXPERT
768 help
769 Enable this for additional checks during memory initialisation.
770 The sanity checks verify aspects of the VM such as the memory model
771 and other information provided by the architecture. Verbose
772 information will be printed at KERN_DEBUG loglevel depending
773 on the mminit_loglevel= command-line option.
774
775 If unsure, say Y
776
777config MEMORY_NOTIFIER_ERROR_INJECT
778 tristate "Memory hotplug notifier error injection module"
779 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
780 help
781 This option provides the ability to inject artificial errors to
782 memory hotplug notifier chain callbacks. It is controlled through
783 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
784
785 If the notifier call chain should be failed with some events
786 notified, write the error code to "actions/<notifier event>/error".
787
788 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
789
790 # cd /sys/kernel/debug/notifier-error-inject/memory
791 # echo -12 > actions/MEM_GOING_OFFLINE/error
792 # echo offline > /sys/devices/system/memory/memoryXXX/state
793 bash: echo: write error: Cannot allocate memory
794
795 To compile this code as a module, choose M here: the module will
796 be called memory-notifier-error-inject.
797
798 If unsure, say N.
799
800config DEBUG_PER_CPU_MAPS
801 bool "Debug access to per_cpu maps"
802 depends on DEBUG_KERNEL
803 depends on SMP
804 help
805 Say Y to verify that the per_cpu map being accessed has
806 been set up. This adds a fair amount of code to kernel memory
807 and decreases performance.
808
809 Say N if unsure.
810
811config DEBUG_HIGHMEM
812 bool "Highmem debugging"
813 depends on DEBUG_KERNEL && HIGHMEM
814 help
b1357c9f
GU
815 This option enables additional error checking for high memory
816 systems. Disable for production systems.
0610c8a8
DH
817
818config HAVE_DEBUG_STACKOVERFLOW
819 bool
820
821config DEBUG_STACKOVERFLOW
822 bool "Check for stack overflows"
823 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
a7f7f624 824 help
0610c8a8 825 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 826 and exception stacks (if your architecture uses them). This
0610c8a8
DH
827 option will show detailed messages if free stack space drops
828 below a certain limit.
829
830 These kinds of bugs usually occur when call-chains in the
831 kernel get too deep, especially when interrupts are
832 involved.
833
834 Use this in cases where you see apparently random memory
835 corruption, especially if it appears in 'struct thread_info'
836
837 If in doubt, say "N".
838
0b24becc
AR
839source "lib/Kconfig.kasan"
840
0610c8a8
DH
841endmenu # "Memory Debugging"
842
a304e1b8
DW
843config DEBUG_SHIRQ
844 bool "Debug shared IRQ handlers"
0244ad00 845 depends on DEBUG_KERNEL
a304e1b8
DW
846 help
847 Enable this to generate a spurious interrupt as soon as a shared
848 interrupt handler is registered, and just before one is deregistered.
849 Drivers ought to be able to handle interrupts coming in at those
850 points; some don't and need to be caught.
851
f43a289d
CD
852menu "Debug Oops, Lockups and Hangs"
853
854config PANIC_ON_OOPS
855 bool "Panic on Oops"
856 help
857 Say Y here to enable the kernel to panic when it oopses. This
858 has the same effect as setting oops=panic on the kernel command
859 line.
860
861 This feature is useful to ensure that the kernel does not do
862 anything erroneous after an oops which could result in data
863 corruption or other issues.
864
865 Say N if unsure.
866
867config PANIC_ON_OOPS_VALUE
868 int
869 range 0 1
870 default 0 if !PANIC_ON_OOPS
871 default 1 if PANIC_ON_OOPS
872
873config PANIC_TIMEOUT
874 int "panic timeout"
875 default 0
876 help
877 Set the timeout value (in seconds) until a reboot occurs when the
878 the kernel panics. If n = 0, then we wait forever. A timeout
879 value n > 0 will wait n seconds before rebooting, while a timeout
880 value n < 0 will reboot immediately.
92aef8fb 881
58687acb 882config LOCKUP_DETECTOR
05a4a952
NP
883 bool
884
885config SOFTLOCKUP_DETECTOR
886 bool "Detect Soft Lockups"
dea20a3f 887 depends on DEBUG_KERNEL && !S390
05a4a952 888 select LOCKUP_DETECTOR
8446f1d3 889 help
58687acb 890 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 891 soft lockups.
58687acb
DZ
892
893 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 894 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
895 chance to run. The current stack trace is displayed upon
896 detection and the system will stay locked up.
8446f1d3 897
5f00ae0d
RD
898config BOOTPARAM_SOFTLOCKUP_PANIC
899 bool "Panic (Reboot) On Soft Lockups"
900 depends on SOFTLOCKUP_DETECTOR
901 help
902 Say Y here to enable the kernel to panic on "soft lockups",
903 which are bugs that cause the kernel to loop in kernel
904 mode for more than 20 seconds (configurable using the watchdog_thresh
905 sysctl), without giving other tasks a chance to run.
906
907 The panic can be used in combination with panic_timeout,
908 to cause the system to reboot automatically after a
909 lockup has been detected. This feature is useful for
910 high-availability systems that have uptime guarantees and
911 where a lockup must be resolved ASAP.
912
913 Say N if unsure.
914
915config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
916 int
917 depends on SOFTLOCKUP_DETECTOR
918 range 0 1
919 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
920 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
921
05a4a952
NP
922config HARDLOCKUP_DETECTOR_PERF
923 bool
924 select SOFTLOCKUP_DETECTOR
925
7edaeb68
TG
926#
927# Enables a timestamp based low pass filter to compensate for perf based
928# hard lockup detection which runs too fast due to turbo modes.
929#
930config HARDLOCKUP_CHECK_TIMESTAMP
931 bool
932
05a4a952
NP
933#
934# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
935# lockup detector rather than the perf based detector.
936#
937config HARDLOCKUP_DETECTOR
938 bool "Detect Hard Lockups"
939 depends on DEBUG_KERNEL && !S390
940 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
941 select LOCKUP_DETECTOR
942 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
943 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
944 help
945 Say Y here to enable the kernel to act as a watchdog to detect
946 hard lockups.
947
58687acb 948 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 949 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
950 chance to run. The current stack trace is displayed upon detection
951 and the system will stay locked up.
8446f1d3 952
fef2c9bc
DZ
953config BOOTPARAM_HARDLOCKUP_PANIC
954 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 955 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
956 help
957 Say Y here to enable the kernel to panic on "hard lockups",
958 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
959 mode with interrupts disabled for more than 10 seconds (configurable
960 using the watchdog_thresh sysctl).
fef2c9bc
DZ
961
962 Say N if unsure.
963
964config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
965 int
8f1f66ed 966 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
967 range 0 1
968 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
969 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
970
e162b39a
MSB
971config DETECT_HUNG_TASK
972 bool "Detect Hung Tasks"
973 depends on DEBUG_KERNEL
05a4a952 974 default SOFTLOCKUP_DETECTOR
e162b39a 975 help
0610c8a8
DH
976 Say Y here to enable the kernel to detect "hung tasks",
977 which are bugs that cause the task to be stuck in
96b03ab8 978 uninterruptible "D" state indefinitely.
1da177e4 979
0610c8a8
DH
980 When a hung task is detected, the kernel will print the
981 current stack trace (which you should report), but the
982 task will stay in uninterruptible state. If lockdep is
983 enabled then all held locks will also be reported. This
984 feature has negligible overhead.
871751e2 985
0610c8a8
DH
986config DEFAULT_HUNG_TASK_TIMEOUT
987 int "Default timeout for hung task detection (in seconds)"
988 depends on DETECT_HUNG_TASK
989 default 120
f0630fff 990 help
0610c8a8
DH
991 This option controls the default timeout (in seconds) used
992 to determine when a task has become non-responsive and should
993 be considered hung.
f0630fff 994
0610c8a8
DH
995 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
996 sysctl or by writing a value to
997 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 998
0610c8a8
DH
999 A timeout of 0 disables the check. The default is two minutes.
1000 Keeping the default should be fine in most cases.
b69ec42b 1001
0610c8a8
DH
1002config BOOTPARAM_HUNG_TASK_PANIC
1003 bool "Panic (Reboot) On Hung Tasks"
1004 depends on DETECT_HUNG_TASK
3bba00d7 1005 help
0610c8a8
DH
1006 Say Y here to enable the kernel to panic on "hung tasks",
1007 which are bugs that cause the kernel to leave a task stuck
1008 in uninterruptible "D" state.
3bba00d7 1009
0610c8a8
DH
1010 The panic can be used in combination with panic_timeout,
1011 to cause the system to reboot automatically after a
1012 hung task has been detected. This feature is useful for
1013 high-availability systems that have uptime guarantees and
1014 where a hung tasks must be resolved ASAP.
bf96d1e3 1015
0610c8a8 1016 Say N if unsure.
bf96d1e3 1017
0610c8a8
DH
1018config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1019 int
1020 depends on DETECT_HUNG_TASK
1021 range 0 1
1022 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1023 default 1 if BOOTPARAM_HUNG_TASK_PANIC
3bba00d7 1024
82607adc
TH
1025config WQ_WATCHDOG
1026 bool "Detect Workqueue Stalls"
1027 depends on DEBUG_KERNEL
1028 help
1029 Say Y here to enable stall detection on workqueues. If a
1030 worker pool doesn't make forward progress on a pending work
1031 item for over a given amount of time, 30s by default, a
1032 warning message is printed along with dump of workqueue
1033 state. This can be configured through kernel parameter
1034 "workqueue.watchdog_thresh" and its sysfs counterpart.
1035
30428ef5
KK
1036config TEST_LOCKUP
1037 tristate "Test module to generate lockups"
1038 help
1039 This builds the "test_lockup" module that helps to make sure
1040 that watchdogs and lockup detectors are working properly.
1041
1042 Depending on module parameters it could emulate soft or hard
1043 lockup, "hung task", or locking arbitrary lock for a long time.
1044 Also it could generate series of lockups with cooling-down periods.
1045
1046 If unsure, say N.
1047
92aef8fb
DH
1048endmenu # "Debug lockups and hangs"
1049
ebebdd09 1050menu "Scheduler Debugging"
5800dc3c 1051
0610c8a8
DH
1052config SCHED_DEBUG
1053 bool "Collect scheduler debugging info"
1054 depends on DEBUG_KERNEL && PROC_FS
1055 default y
0822ee4a 1056 help
0610c8a8
DH
1057 If you say Y here, the /proc/sched_debug file will be provided
1058 that can help debug the scheduler. The runtime overhead of this
1059 option is minimal.
0822ee4a 1060
f6db8347
NR
1061config SCHED_INFO
1062 bool
1063 default n
1064
0610c8a8
DH
1065config SCHEDSTATS
1066 bool "Collect scheduler statistics"
1067 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1068 select SCHED_INFO
0610c8a8
DH
1069 help
1070 If you say Y here, additional code will be inserted into the
1071 scheduler and related routines to collect statistics about
1072 scheduler behavior and provide them in /proc/schedstat. These
1073 stats may be useful for both tuning and debugging the scheduler
1074 If you aren't debugging the scheduler or trying to tune a specific
1075 application, you can say N to avoid the very slight overhead
1076 this adds.
0822ee4a 1077
ebebdd09 1078endmenu
0d9e2632 1079
3c17ad19
JS
1080config DEBUG_TIMEKEEPING
1081 bool "Enable extra timekeeping sanity checking"
1082 help
1083 This option will enable additional timekeeping sanity checks
1084 which may be helpful when diagnosing issues where timekeeping
1085 problems are suspected.
1086
1087 This may include checks in the timekeeping hotpaths, so this
1088 option may have a (very small) performance impact to some
1089 workloads.
1090
1091 If unsure, say N.
1092
1da177e4
LT
1093config DEBUG_PREEMPT
1094 bool "Debug preemptible kernel"
9f472869 1095 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1096 default y
1097 help
1098 If you say Y here then the kernel will use a debug variant of the
1099 commonly used smp_processor_id() function and will print warnings
1100 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1101 will detect preemption count underflows.
1102
9eade16b
DH
1103menu "Lock Debugging (spinlocks, mutexes, etc...)"
1104
f07cbebb
WL
1105config LOCK_DEBUGGING_SUPPORT
1106 bool
1107 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1108 default y
1109
19193bca
WL
1110config PROVE_LOCKING
1111 bool "Lock debugging: prove locking correctness"
1112 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1113 select LOCKDEP
1114 select DEBUG_SPINLOCK
1115 select DEBUG_MUTEXES
1116 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1117 select DEBUG_RWSEMS
19193bca
WL
1118 select DEBUG_WW_MUTEX_SLOWPATH
1119 select DEBUG_LOCK_ALLOC
1120 select TRACE_IRQFLAGS
1121 default n
1122 help
1123 This feature enables the kernel to prove that all locking
1124 that occurs in the kernel runtime is mathematically
1125 correct: that under no circumstance could an arbitrary (and
1126 not yet triggered) combination of observed locking
1127 sequences (on an arbitrary number of CPUs, running an
1128 arbitrary number of tasks and interrupt contexts) cause a
1129 deadlock.
1130
1131 In short, this feature enables the kernel to report locking
1132 related deadlocks before they actually occur.
1133
1134 The proof does not depend on how hard and complex a
1135 deadlock scenario would be to trigger: how many
1136 participant CPUs, tasks and irq-contexts would be needed
1137 for it to trigger. The proof also does not depend on
1138 timing: if a race and a resulting deadlock is possible
1139 theoretically (no matter how unlikely the race scenario
1140 is), it will be proven so and will immediately be
1141 reported by the kernel (once the event is observed that
1142 makes the deadlock theoretically possible).
1143
1144 If a deadlock is impossible (i.e. the locking rules, as
1145 observed by the kernel, are mathematically correct), the
1146 kernel reports nothing.
1147
1148 NOTE: this feature can also be enabled for rwlocks, mutexes
1149 and rwsems - in which case all dependencies between these
1150 different locking variants are observed and mapped too, and
1151 the proof of observed correctness is also maintained for an
1152 arbitrary combination of these separate locking variants.
1153
387b1468 1154 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1155
de8f5e4f
PZ
1156config PROVE_RAW_LOCK_NESTING
1157 bool "Enable raw_spinlock - spinlock nesting checks"
1158 depends on PROVE_LOCKING
1159 default n
1160 help
1161 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1162 that the lock nesting rules for PREEMPT_RT enabled kernels are
1163 not violated.
1164
1165 NOTE: There are known nesting problems. So if you enable this
1166 option expect lockdep splats until these problems have been fully
1167 addressed which is work in progress. This config switch allows to
1168 identify and analyze these problems. It will be removed and the
1169 check permanentely enabled once the main issues have been fixed.
1170
1171 If unsure, select N.
1172
19193bca
WL
1173config LOCK_STAT
1174 bool "Lock usage statistics"
1175 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1176 select LOCKDEP
1177 select DEBUG_SPINLOCK
1178 select DEBUG_MUTEXES
1179 select DEBUG_RT_MUTEXES if RT_MUTEXES
1180 select DEBUG_LOCK_ALLOC
1181 default n
1182 help
1183 This feature enables tracking lock contention points
1184
387b1468 1185 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1186
1187 This also enables lock events required by "perf lock",
1188 subcommand of perf.
1189 If you want to use "perf lock", you also need to turn on
1190 CONFIG_EVENT_TRACING.
1191
1192 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1193 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1194
e7eebaf6
IM
1195config DEBUG_RT_MUTEXES
1196 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1197 depends on DEBUG_KERNEL && RT_MUTEXES
1198 help
1199 This allows rt mutex semantics violations and rt mutex related
1200 deadlocks (lockups) to be detected and reported automatically.
1201
1da177e4 1202config DEBUG_SPINLOCK
4d9f34ad 1203 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1204 depends on DEBUG_KERNEL
e335e3eb 1205 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1206 help
1207 Say Y here and build SMP to catch missing spinlock initialization
1208 and certain other kinds of spinlock errors commonly made. This is
1209 best used in conjunction with the NMI watchdog so that spinlock
1210 deadlocks are also debuggable.
1211
4d9f34ad
IM
1212config DEBUG_MUTEXES
1213 bool "Mutex debugging: basic checks"
1214 depends on DEBUG_KERNEL
1215 help
1216 This feature allows mutex semantics violations to be detected and
1217 reported.
1218
23010027
DV
1219config DEBUG_WW_MUTEX_SLOWPATH
1220 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1221 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1222 select DEBUG_LOCK_ALLOC
1223 select DEBUG_SPINLOCK
1224 select DEBUG_MUTEXES
1225 help
1226 This feature enables slowpath testing for w/w mutex users by
1227 injecting additional -EDEADLK wound/backoff cases. Together with
1228 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1229 will test all possible w/w mutex interface abuse with the
1230 exception of simply not acquiring all the required locks.
4d692373
RC
1231 Note that this feature can introduce significant overhead, so
1232 it really should not be enabled in a production or distro kernel,
1233 even a debug kernel. If you are a driver writer, enable it. If
1234 you are a distro, do not.
23010027 1235
5149cbac
WL
1236config DEBUG_RWSEMS
1237 bool "RW Semaphore debugging: basic checks"
c71fd893 1238 depends on DEBUG_KERNEL
5149cbac 1239 help
c71fd893
WL
1240 This debugging feature allows mismatched rw semaphore locks
1241 and unlocks to be detected and reported.
5149cbac 1242
4d9f34ad
IM
1243config DEBUG_LOCK_ALLOC
1244 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1245 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad
IM
1246 select DEBUG_SPINLOCK
1247 select DEBUG_MUTEXES
f5694788 1248 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1249 select LOCKDEP
1250 help
1251 This feature will check whether any held lock (spinlock, rwlock,
1252 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1253 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1254 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1255 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1256 held during task exit.
1257
4d9f34ad
IM
1258config LOCKDEP
1259 bool
f07cbebb 1260 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1261 select STACKTRACE
f9b58e8c 1262 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
4d9f34ad
IM
1263 select KALLSYMS
1264 select KALLSYMS_ALL
1265
395102db
DJ
1266config LOCKDEP_SMALL
1267 bool
1268
4d9f34ad
IM
1269config DEBUG_LOCKDEP
1270 bool "Lock dependency engine debugging"
517e7aa5 1271 depends on DEBUG_KERNEL && LOCKDEP
4d9f34ad
IM
1272 help
1273 If you say Y here, the lock dependency engine will do
1274 additional runtime checks to debug itself, at the price
1275 of more runtime overhead.
1276
d902db1e
FW
1277config DEBUG_ATOMIC_SLEEP
1278 bool "Sleep inside atomic section checking"
e8f7c70f 1279 select PREEMPT_COUNT
1da177e4 1280 depends on DEBUG_KERNEL
87a4c375 1281 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1282 help
1283 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1284 noisy if they are called inside atomic sections: when a spinlock is
1285 held, inside an rcu read side critical section, inside preempt disabled
1286 sections, inside an interrupt, etc...
1da177e4 1287
cae2ed9a
IM
1288config DEBUG_LOCKING_API_SELFTESTS
1289 bool "Locking API boot-time self-tests"
1290 depends on DEBUG_KERNEL
1291 help
1292 Say Y here if you want the kernel to run a short self-test during
1293 bootup. The self-test checks whether common types of locking bugs
1294 are detected by debugging mechanisms or not. (if you disable
1295 lock debugging then those bugs wont be detected of course.)
1296 The following locking APIs are covered: spinlocks, rwlocks,
1297 mutexes and rwsems.
1298
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PM
1299config LOCK_TORTURE_TEST
1300 tristate "torture tests for locking"
1301 depends on DEBUG_KERNEL
1302 select TORTURE_TEST
0af3fe1e
PM
1303 help
1304 This option provides a kernel module that runs torture tests
1305 on kernel locking primitives. The kernel module may be built
1306 after the fact on the running kernel to be tested, if desired.
1307
1308 Say Y here if you want kernel locking-primitive torture tests
1309 to be built into the kernel.
1310 Say M if you want these torture tests to build as a module.
1311 Say N if you are unsure.
1312
f2a5fec1
CW
1313config WW_MUTEX_SELFTEST
1314 tristate "Wait/wound mutex selftests"
1315 help
1316 This option provides a kernel module that runs tests on the
1317 on the struct ww_mutex locking API.
1318
1319 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1320 with this test harness.
1321
1322 Say M if you want these self tests to build as a module.
1323 Say N if you are unsure.
1324
9eade16b 1325endmenu # lock debugging
8637c099 1326
9eade16b
DH
1327config TRACE_IRQFLAGS
1328 bool
5ca43f6c 1329 help
9eade16b
DH
1330 Enables hooks to interrupt enabling and disabling for
1331 either tracing or lock debugging.
5ca43f6c 1332
8637c099 1333config STACKTRACE
0c38e1fe 1334 bool "Stack backtrace support"
8637c099 1335 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1336 help
1337 This option causes the kernel to create a /proc/pid/stack for
1338 every process, showing its current stack trace.
1339 It is also used by various kernel debugging features that require
1340 stack trace generation.
5ca43f6c 1341
eecabf56
TT
1342config WARN_ALL_UNSEEDED_RANDOM
1343 bool "Warn for all uses of unseeded randomness"
1344 default n
d06bfd19
JD
1345 help
1346 Some parts of the kernel contain bugs relating to their use of
1347 cryptographically secure random numbers before it's actually possible
1348 to generate those numbers securely. This setting ensures that these
1349 flaws don't go unnoticed, by enabling a message, should this ever
1350 occur. This will allow people with obscure setups to know when things
1351 are going wrong, so that they might contact developers about fixing
1352 it.
1353
eecabf56
TT
1354 Unfortunately, on some models of some architectures getting
1355 a fully seeded CRNG is extremely difficult, and so this can
1356 result in dmesg getting spammed for a surprisingly long
1357 time. This is really bad from a security perspective, and
1358 so architecture maintainers really need to do what they can
1359 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1360 However, since users cannot do anything actionable to
eecabf56
TT
1361 address this, by default the kernel will issue only a single
1362 warning for the first use of unseeded randomness.
1363
1364 Say Y here if you want to receive warnings for all uses of
1365 unseeded randomness. This will be of use primarily for
4c5d114e 1366 those developers interested in improving the security of
eecabf56
TT
1367 Linux kernels running on their architecture (or
1368 subarchitecture).
d06bfd19 1369
1da177e4
LT
1370config DEBUG_KOBJECT
1371 bool "kobject debugging"
1372 depends on DEBUG_KERNEL
1373 help
1374 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1375 to the syslog.
1da177e4 1376
c817a67e
RK
1377config DEBUG_KOBJECT_RELEASE
1378 bool "kobject release debugging"
2a999aa0 1379 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1380 help
1381 kobjects are reference counted objects. This means that their
1382 last reference count put is not predictable, and the kobject can
1383 live on past the point at which a driver decides to drop it's
1384 initial reference to the kobject gained on allocation. An
1385 example of this would be a struct device which has just been
1386 unregistered.
1387
1388 However, some buggy drivers assume that after such an operation,
1389 the memory backing the kobject can be immediately freed. This
1390 goes completely against the principles of a refcounted object.
1391
1392 If you say Y here, the kernel will delay the release of kobjects
1393 on the last reference count to improve the visibility of this
1394 kind of kobject release bug.
1395
9b2a60c4
CM
1396config HAVE_DEBUG_BUGVERBOSE
1397 bool
1398
3be5cbcd 1399menu "Debug kernel data structures"
1da177e4 1400
199a9afc
DJ
1401config DEBUG_LIST
1402 bool "Debug linked list manipulation"
4520bcb2 1403 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1404 help
1405 Enable this to turn on extended checks in the linked-list
1406 walking routines.
1407
1408 If unsure, say N.
1409
8e18faea 1410config DEBUG_PLIST
b8cfff68
DS
1411 bool "Debug priority linked list manipulation"
1412 depends on DEBUG_KERNEL
1413 help
1414 Enable this to turn on extended checks in the priority-ordered
1415 linked-list (plist) walking routines. This checks the entire
1416 list multiple times during each manipulation.
1417
1418 If unsure, say N.
1419
d6ec0842
JA
1420config DEBUG_SG
1421 bool "Debug SG table operations"
1422 depends on DEBUG_KERNEL
1423 help
1424 Enable this to turn on checks on scatter-gather tables. This can
1425 help find problems with drivers that do not properly initialize
1426 their sg tables.
1427
1428 If unsure, say N.
1429
1b2439db
AV
1430config DEBUG_NOTIFIERS
1431 bool "Debug notifier call chains"
1432 depends on DEBUG_KERNEL
1433 help
1434 Enable this to turn on sanity checking for notifier call chains.
1435 This is most useful for kernel developers to make sure that
1436 modules properly unregister themselves from notifier chains.
1437 This is a relatively cheap check but if you care about maximum
1438 performance, say N.
1439
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CD
1440config BUG_ON_DATA_CORRUPTION
1441 bool "Trigger a BUG when data corruption is detected"
1442 select DEBUG_LIST
1443 help
1444 Select this option if the kernel should BUG when it encounters
1445 data corruption in kernel memory structures when they get checked
1446 for validity.
1447
1448 If unsure, say N.
1449
1450endmenu
1451
e0e81739
DH
1452config DEBUG_CREDENTIALS
1453 bool "Debug credential management"
1454 depends on DEBUG_KERNEL
1455 help
1456 Enable this to turn on some debug checking for credential
1457 management. The additional code keeps track of the number of
1458 pointers from task_structs to any given cred struct, and checks to
1459 see that this number never exceeds the usage count of the cred
1460 struct.
1461
1462 Furthermore, if SELinux is enabled, this also checks that the
1463 security pointer in the cred struct is never seen to be invalid.
1464
1465 If unsure, say N.
1466
43a0a2a7 1467source "kernel/rcu/Kconfig.debug"
2f03e3ca 1468
f303fccb
TH
1469config DEBUG_WQ_FORCE_RR_CPU
1470 bool "Force round-robin CPU selection for unbound work items"
1471 depends on DEBUG_KERNEL
1472 default n
1473 help
1474 Workqueue used to implicitly guarantee that work items queued
1475 without explicit CPU specified are put on the local CPU. This
1476 guarantee is no longer true and while local CPU is still
1477 preferred work items may be put on foreign CPUs. Kernel
1478 parameter "workqueue.debug_force_rr_cpu" is added to force
1479 round-robin CPU selection to flush out usages which depend on the
1480 now broken guarantee. This config option enables the debug
1481 feature by default. When enabled, memory and cache locality will
1482 be impacted.
1483
870d6656 1484config DEBUG_BLOCK_EXT_DEVT
68d4b3df 1485 bool "Force extended block device numbers and spread them"
870d6656
TH
1486 depends on DEBUG_KERNEL
1487 depends on BLOCK
759f8ca3 1488 default n
870d6656 1489 help
0e11e342
TH
1490 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1491 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1492 YOU ARE DOING. Distros, please enable this and fix whatever
1493 is broken.
1494
870d6656
TH
1495 Conventionally, block device numbers are allocated from
1496 predetermined contiguous area. However, extended block area
1497 may introduce non-contiguous block device numbers. This
1498 option forces most block device numbers to be allocated from
1499 the extended space and spreads them to discover kernel or
1500 userland code paths which assume predetermined contiguous
1501 device number allocation.
1502
55dc7db7
TH
1503 Note that turning on this debug option shuffles all the
1504 device numbers for all IDE and SCSI devices including libata
1505 ones, so root partition specified using device number
1506 directly (via rdev or root=MAJ:MIN) won't work anymore.
1507 Textual device names (root=/dev/sdXn) will continue to work.
1508
870d6656
TH
1509 Say N if you are unsure.
1510
757c989b
TG
1511config CPU_HOTPLUG_STATE_CONTROL
1512 bool "Enable CPU hotplug state control"
1513 depends on DEBUG_KERNEL
1514 depends on HOTPLUG_CPU
1515 default n
1516 help
1517 Allows to write steps between "offline" and "online" to the CPUs
1518 sysfs target file so states can be stepped granular. This is a debug
1519 option for now as the hotplug machinery cannot be stopped and
1520 restarted at arbitrary points yet.
1521
1522 Say N if your are unsure.
1523
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CD
1524config LATENCYTOP
1525 bool "Latency measuring infrastructure"
1526 depends on DEBUG_KERNEL
1527 depends on STACKTRACE_SUPPORT
1528 depends on PROC_FS
1529 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1530 select KALLSYMS
1531 select KALLSYMS_ALL
1532 select STACKTRACE
1533 select SCHEDSTATS
1534 select SCHED_DEBUG
1535 help
1536 Enable this option if you want to use the LatencyTOP tool
1537 to find out which userspace is blocking on what kernel operations.
1538
1539source "kernel/trace/Kconfig"
1540
1541config PROVIDE_OHCI1394_DMA_INIT
1542 bool "Remote debugging over FireWire early on boot"
1543 depends on PCI && X86
1544 help
1545 If you want to debug problems which hang or crash the kernel early
1546 on boot and the crashing machine has a FireWire port, you can use
1547 this feature to remotely access the memory of the crashed machine
1548 over FireWire. This employs remote DMA as part of the OHCI1394
1549 specification which is now the standard for FireWire controllers.
1550
1551 With remote DMA, you can monitor the printk buffer remotely using
1552 firescope and access all memory below 4GB using fireproxy from gdb.
1553 Even controlling a kernel debugger is possible using remote DMA.
1554
1555 Usage:
1556
1557 If ohci1394_dma=early is used as boot parameter, it will initialize
1558 all OHCI1394 controllers which are found in the PCI config space.
1559
1560 As all changes to the FireWire bus such as enabling and disabling
1561 devices cause a bus reset and thereby disable remote DMA for all
1562 devices, be sure to have the cable plugged and FireWire enabled on
1563 the debugging host before booting the debug target for debugging.
1564
1565 This code (~1k) is freed after boot. By then, the firewire stack
1566 in charge of the OHCI-1394 controllers should be used instead.
1567
a74e2a22 1568 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
09a74952 1569
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CD
1570source "samples/Kconfig"
1571
28336be5
IM
1572source "lib/Kconfig.kcsan"
1573
045f6d79
CD
1574config ARCH_HAS_DEVMEM_IS_ALLOWED
1575 bool
1576
1577config STRICT_DEVMEM
1578 bool "Filter access to /dev/mem"
1579 depends on MMU && DEVMEM
1580 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1581 default y if PPC || X86 || ARM64
1582 help
1583 If this option is disabled, you allow userspace (root) access to all
1584 of memory, including kernel and userspace memory. Accidental
1585 access to this is obviously disastrous, but specific access can
1586 be used by people debugging the kernel. Note that with PAT support
1587 enabled, even in this case there are restrictions on /dev/mem
1588 use due to the cache aliasing requirements.
1589
1590 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1591 file only allows userspace access to PCI space and the BIOS code and
1592 data regions. This is sufficient for dosemu and X and all common
1593 users of /dev/mem.
1594
1595 If in doubt, say Y.
1596
1597config IO_STRICT_DEVMEM
1598 bool "Filter I/O access to /dev/mem"
1599 depends on STRICT_DEVMEM
1600 help
1601 If this option is disabled, you allow userspace (root) access to all
1602 io-memory regardless of whether a driver is actively using that
1603 range. Accidental access to this is obviously disastrous, but
1604 specific access can be used by people debugging kernel drivers.
1605
1606 If this option is switched on, the /dev/mem file only allows
1607 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1608 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1609 if the driver using a given range cannot be disabled.
1610
1611 If in doubt, say Y.
1612
1613menu "$(SRCARCH) Debugging"
1614
1615source "arch/$(SRCARCH)/Kconfig.debug"
1616
1617endmenu
1618
1619menu "Kernel Testing and Coverage"
1620
09a74952
CD
1621source "lib/kunit/Kconfig"
1622
8d438288
AM
1623config NOTIFIER_ERROR_INJECTION
1624 tristate "Notifier error injection"
1625 depends on DEBUG_KERNEL
1626 select DEBUG_FS
1627 help
e41e85cc 1628 This option provides the ability to inject artificial errors to
8d438288
AM
1629 specified notifier chain callbacks. It is useful to test the error
1630 handling of notifier call chain failures.
1631
1632 Say N if unsure.
1633
048b9c35
AM
1634config PM_NOTIFIER_ERROR_INJECT
1635 tristate "PM notifier error injection module"
1636 depends on PM && NOTIFIER_ERROR_INJECTION
1637 default m if PM_DEBUG
1638 help
e41e85cc 1639 This option provides the ability to inject artificial errors to
048b9c35
AM
1640 PM notifier chain callbacks. It is controlled through debugfs
1641 interface /sys/kernel/debug/notifier-error-inject/pm
1642
1643 If the notifier call chain should be failed with some events
1644 notified, write the error code to "actions/<notifier event>/error".
1645
1646 Example: Inject PM suspend error (-12 = -ENOMEM)
1647
1648 # cd /sys/kernel/debug/notifier-error-inject/pm/
1649 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1650 # echo mem > /sys/power/state
1651 bash: echo: write error: Cannot allocate memory
1652
1653 To compile this code as a module, choose M here: the module will
1654 be called pm-notifier-error-inject.
1655
1656 If unsure, say N.
1657
d526e85f
BH
1658config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1659 tristate "OF reconfig notifier error injection module"
1660 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1661 help
e41e85cc 1662 This option provides the ability to inject artificial errors to
d526e85f 1663 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1664 through debugfs interface under
d526e85f 1665 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1666
1667 If the notifier call chain should be failed with some events
1668 notified, write the error code to "actions/<notifier event>/error".
1669
1670 To compile this code as a module, choose M here: the module will
e12a95f4 1671 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1672
1673 If unsure, say N.
1674
02fff96a
NA
1675config NETDEV_NOTIFIER_ERROR_INJECT
1676 tristate "Netdev notifier error injection module"
1677 depends on NET && NOTIFIER_ERROR_INJECTION
1678 help
1679 This option provides the ability to inject artificial errors to
1680 netdevice notifier chain callbacks. It is controlled through debugfs
1681 interface /sys/kernel/debug/notifier-error-inject/netdev
1682
1683 If the notifier call chain should be failed with some events
1684 notified, write the error code to "actions/<notifier event>/error".
1685
1686 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1687
1688 # cd /sys/kernel/debug/notifier-error-inject/netdev
1689 # echo -22 > actions/NETDEV_CHANGEMTU/error
1690 # ip link set eth0 mtu 1024
1691 RTNETLINK answers: Invalid argument
1692
1693 To compile this code as a module, choose M here: the module will
1694 be called netdev-notifier-error-inject.
1695
1696 If unsure, say N.
1697
f1b4bd06
MP
1698config FUNCTION_ERROR_INJECTION
1699 def_bool y
1700 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1701
6ff1cb35 1702config FAULT_INJECTION
1ab8509a
AM
1703 bool "Fault-injection framework"
1704 depends on DEBUG_KERNEL
329409ae
AM
1705 help
1706 Provide fault-injection framework.
1707 For more details, see Documentation/fault-injection/.
6ff1cb35 1708
8a8b6502 1709config FAILSLAB
1ab8509a
AM
1710 bool "Fault-injection capability for kmalloc"
1711 depends on FAULT_INJECTION
773ff60e 1712 depends on SLAB || SLUB
8a8b6502 1713 help
1ab8509a 1714 Provide fault-injection capability for kmalloc.
8a8b6502 1715
933e312e 1716config FAIL_PAGE_ALLOC
29b46fa3 1717 bool "Fault-injection capability for alloc_pages()"
1ab8509a 1718 depends on FAULT_INJECTION
933e312e 1719 help
1ab8509a 1720 Provide fault-injection capability for alloc_pages().
933e312e 1721
c17bb495 1722config FAIL_MAKE_REQUEST
86327d19 1723 bool "Fault-injection capability for disk IO"
581d4e28 1724 depends on FAULT_INJECTION && BLOCK
c17bb495 1725 help
1ab8509a 1726 Provide fault-injection capability for disk IO.
c17bb495 1727
581d4e28 1728config FAIL_IO_TIMEOUT
f4d01439 1729 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1730 depends on FAULT_INJECTION && BLOCK
1731 help
1732 Provide fault-injection capability on end IO handling. This
1733 will make the block layer "forget" an interrupt as configured,
1734 thus exercising the error handling.
1735
1736 Only works with drivers that use the generic timeout handling,
1737 for others it wont do anything.
1738
ab51fbab
DB
1739config FAIL_FUTEX
1740 bool "Fault-injection capability for futexes"
1741 select DEBUG_FS
1742 depends on FAULT_INJECTION && FUTEX
1743 help
1744 Provide fault-injection capability for futexes.
1745
f1b4bd06
MP
1746config FAULT_INJECTION_DEBUG_FS
1747 bool "Debugfs entries for fault-injection capabilities"
1748 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1749 help
1750 Enable configuration of fault-injection capabilities via debugfs.
1751
4b1a29a7
MH
1752config FAIL_FUNCTION
1753 bool "Fault-injection capability for functions"
1754 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1755 help
1756 Provide function-based fault-injection capability.
1757 This will allow you to override a specific function with a return
1758 with given return value. As a result, function caller will see
1759 an error value and have to handle it. This is useful to test the
1760 error handling in various subsystems.
1761
f1b4bd06
MP
1762config FAIL_MMC_REQUEST
1763 bool "Fault-injection capability for MMC IO"
1764 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1765 help
f1b4bd06
MP
1766 Provide fault-injection capability for MMC IO.
1767 This will make the mmc core return data errors. This is
1768 useful to test the error handling in the mmc block device
1769 and to test how the mmc host driver handles retries from
1770 the block device.
1df49008
AM
1771
1772config FAULT_INJECTION_STACKTRACE_FILTER
1773 bool "stacktrace filter for fault-injection capabilities"
1774 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 1775 depends on !X86_64
1df49008 1776 select STACKTRACE
f9b58e8c 1777 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1df49008
AM
1778 help
1779 Provide stacktrace filter for fault-injection capabilities
267c4025 1780
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CD
1781config ARCH_HAS_KCOV
1782 bool
cc3fa840 1783 help
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CD
1784 An architecture should select this when it can successfully
1785 build and run with CONFIG_KCOV. This typically requires
1786 disabling instrumentation for some early boot code.
cc3fa840 1787
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CD
1788config CC_HAS_SANCOV_TRACE_PC
1789 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 1790
cc3fa840 1791
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CD
1792config KCOV
1793 bool "Code coverage for fuzzing"
1794 depends on ARCH_HAS_KCOV
1795 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1796 select DEBUG_FS
1797 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1798 help
1799 KCOV exposes kernel code coverage information in a form suitable
1800 for coverage-guided fuzzing (randomized testing).
cc3fa840 1801
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CD
1802 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1803 different machines and across reboots. If you need stable PC values,
1804 disable RANDOMIZE_BASE.
cc3fa840 1805
09a74952 1806 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 1807
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CD
1808config KCOV_ENABLE_COMPARISONS
1809 bool "Enable comparison operands collection by KCOV"
1810 depends on KCOV
1811 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1812 help
1813 KCOV also exposes operands of every comparison in the instrumented
1814 code along with operand sizes and PCs of the comparison instructions.
1815 These operands can be used by fuzzing engines to improve the quality
1816 of fuzzing coverage.
cc3fa840 1817
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CD
1818config KCOV_INSTRUMENT_ALL
1819 bool "Instrument all code by default"
1820 depends on KCOV
1821 default y
1822 help
1823 If you are doing generic system call fuzzing (like e.g. syzkaller),
1824 then you will want to instrument the whole kernel and you should
1825 say y here. If you are doing more targeted fuzzing (like e.g.
1826 filesystem fuzzing with AFL) then you will want to enable coverage
1827 for more specific subsets of files, and should say n here.
84bc809e 1828
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AK
1829config KCOV_IRQ_AREA_SIZE
1830 hex "Size of interrupt coverage collection area in words"
1831 depends on KCOV
1832 default 0x40000
1833 help
1834 KCOV uses preallocated per-cpu areas to collect coverage from
1835 soft interrupts. This specifies the size of those areas in the
1836 number of unsigned long words.
1837
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VL
1838menuconfig RUNTIME_TESTING_MENU
1839 bool "Runtime Testing"
908009e8 1840 def_bool y
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VL
1841
1842if RUNTIME_TESTING_MENU
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DH
1843
1844config LKDTM
1845 tristate "Linux Kernel Dump Test Tool Module"
1846 depends on DEBUG_FS
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DH
1847 help
1848 This module enables testing of the different dumping mechanisms by
1849 inducing system failures at predefined crash points.
1850 If you don't need it: say N
1851 Choose M here to compile this code as a module. The module will be
1852 called lkdtm.
1853
1854 Documentation on how to use the module can be found in
10ffebbe 1855 Documentation/fault-injection/provoke-crashes.rst
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DH
1856
1857config TEST_LIST_SORT
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GU
1858 tristate "Linked list sorting test"
1859 depends on DEBUG_KERNEL || m
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DH
1860 help
1861 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
1862 executed only once during system boot (so affects only boot time),
1863 or at module load time.
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DH
1864
1865 If unsure, say N.
1866
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IR
1867config TEST_MIN_HEAP
1868 tristate "Min heap test"
1869 depends on DEBUG_KERNEL || m
1870 help
1871 Enable this to turn on min heap function tests. This test is
1872 executed only once during system boot (so affects only boot time),
1873 or at module load time.
1874
1875 If unsure, say N.
1876
c5adae95 1877config TEST_SORT
5c4e6798
GU
1878 tristate "Array-based sort test"
1879 depends on DEBUG_KERNEL || m
c5adae95 1880 help
5c4e6798
GU
1881 This option enables the self-test function of 'sort()' at boot,
1882 or at module load time.
c5adae95
KF
1883
1884 If unsure, say N.
1885
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DH
1886config KPROBES_SANITY_TEST
1887 bool "Kprobes sanity tests"
1888 depends on DEBUG_KERNEL
1889 depends on KPROBES
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DH
1890 help
1891 This option provides for testing basic kprobes functionality on
5a6cf77f 1892 boot. Samples of kprobe and kretprobe are inserted and
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DH
1893 verified for functionality.
1894
1895 Say N if you are unsure.
1896
1897config BACKTRACE_SELF_TEST
1898 tristate "Self test for the backtrace code"
1899 depends on DEBUG_KERNEL
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DH
1900 help
1901 This option provides a kernel module that can be used to test
1902 the kernel stack backtrace code. This option is not useful
1903 for distributions or general kernels, but only for kernel
1904 developers working on architecture code.
1905
1906 Note that if you want to also test saved backtraces, you will
1907 have to enable STACKTRACE as well.
1908
1909 Say N if you are unsure.
1910
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ML
1911config RBTREE_TEST
1912 tristate "Red-Black tree test"
7c993e11 1913 depends on DEBUG_KERNEL
910a742d
ML
1914 help
1915 A benchmark measuring the performance of the rbtree library.
1916 Also includes rbtree invariant checks.
1917
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FB
1918config REED_SOLOMON_TEST
1919 tristate "Reed-Solomon library test"
1920 depends on DEBUG_KERNEL || m
1921 select REED_SOLOMON
1922 select REED_SOLOMON_ENC16
1923 select REED_SOLOMON_DEC16
1924 help
1925 This option enables the self-test function of rslib at boot,
1926 or at module load time.
1927
1928 If unsure, say N.
1929
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ML
1930config INTERVAL_TREE_TEST
1931 tristate "Interval tree test"
0f789b67 1932 depends on DEBUG_KERNEL
a88cc108 1933 select INTERVAL_TREE
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ML
1934 help
1935 A benchmark measuring the performance of the interval tree library
1936
623fd807
GT
1937config PERCPU_TEST
1938 tristate "Per cpu operations test"
1939 depends on m && DEBUG_KERNEL
1940 help
1941 Enable this option to build test module which validates per-cpu
1942 operations.
1943
1944 If unsure, say N.
1945
881c5149 1946config ATOMIC64_SELFTEST
55ded955 1947 tristate "Perform an atomic64_t self-test"
881c5149 1948 help
55ded955
GU
1949 Enable this option to test the atomic64_t functions at boot or
1950 at module load time.
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DH
1951
1952 If unsure, say N.
1953
1954config ASYNC_RAID6_TEST
1955 tristate "Self test for hardware accelerated raid6 recovery"
1956 depends on ASYNC_RAID6_RECOV
1957 select ASYNC_MEMCPY
a7f7f624 1958 help
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DH
1959 This is a one-shot self test that permutes through the
1960 recovery of all the possible two disk failure scenarios for a
1961 N-disk array. Recovery is performed with the asynchronous
1962 raid6 recovery routines, and will optionally use an offload
1963 engine if one is available.
1964
1965 If unsure, say N.
1966
64d1d77a
AS
1967config TEST_HEXDUMP
1968 tristate "Test functions located in the hexdump module at runtime"
1969
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DH
1970config TEST_STRING_HELPERS
1971 tristate "Test functions located in the string_helpers module at runtime"
1972
0b0600c8
TH
1973config TEST_STRSCPY
1974 tristate "Test strscpy*() family of functions at runtime"
1975
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DH
1976config TEST_KSTRTOX
1977 tristate "Test kstrto*() family of functions at runtime"
1978
707cc728
RV
1979config TEST_PRINTF
1980 tristate "Test printf() family of functions at runtime"
1981
5fd003f5
DD
1982config TEST_BITMAP
1983 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
1984 help
1985 Enable this option to test the bitmap functions at boot.
1986
1987 If unsure, say N.
1988
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JB
1989config TEST_BITFIELD
1990 tristate "Test bitfield functions at runtime"
1991 help
1992 Enable this option to test the bitfield functions at boot.
1993
1994 If unsure, say N.
1995
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AS
1996config TEST_UUID
1997 tristate "Test functions located in the uuid module at runtime"
1998
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MW
1999config TEST_XARRAY
2000 tristate "Test the XArray code at runtime"
2001
455a35a6
RV
2002config TEST_OVERFLOW
2003 tristate "Test check_*_overflow() functions at runtime"
2004
7e1e7763 2005config TEST_RHASHTABLE
9d6dbe1b 2006 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
2007 help
2008 Enable this option to test the rhashtable functions at boot.
2009
2010 If unsure, say N.
2011
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GS
2012config TEST_HASH
2013 tristate "Perform selftest on hash functions"
468a9428 2014 help
2c956a60
JD
2015 Enable this option to test the kernel's integer (<linux/hash.h>),
2016 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2017 hash functions on boot (or module load).
468a9428
GS
2018
2019 This is intended to help people writing architecture-specific
2020 optimized versions. If unsure, say N.
2021
8ab8ba38
MW
2022config TEST_IDA
2023 tristate "Perform selftest on IDA functions"
2024
44091d29
JP
2025config TEST_PARMAN
2026 tristate "Perform selftest on priority array manager"
44091d29
JP
2027 depends on PARMAN
2028 help
2029 Enable this option to test priority array manager on boot
2030 (or module load).
2031
2032 If unsure, say N.
2033
6aed82de
DL
2034config TEST_IRQ_TIMINGS
2035 bool "IRQ timings selftest"
2036 depends on IRQ_TIMINGS
2037 help
2038 Enable this option to test the irq timings code on boot.
2039
2040 If unsure, say N.
2041
8a6f0b47 2042config TEST_LKM
93e9ef83 2043 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
2044 depends on m
2045 help
2046 This builds the "test_module" module that emits "Hello, world"
2047 on printk when loaded. It is designed to be used for basic
2048 evaluation of the module loading subsystem (for example when
2049 validating module verification). It lacks any extra dependencies,
2050 and will not normally be loaded by the system unless explicitly
2051 requested by name.
2052
2053 If unsure, say N.
2054
c348c163 2055config TEST_BITOPS
6af132f3 2056 tristate "Test module for compilation of bitops operations"
c348c163
JB
2057 depends on m
2058 help
2059 This builds the "test_bitops" module that is much like the
2060 TEST_LKM module except that it does a basic exercise of the
6af132f3
WY
2061 set/clear_bit macros and get_count_order/long to make sure there are
2062 no compiler warnings from C=1 sparse checker or -Wextra
2063 compilations. It has no dependencies and doesn't run or load unless
2064 explicitly requested by name. for example: modprobe test_bitops.
c348c163
JB
2065
2066 If unsure, say N.
2067
3f21a6b7
URS
2068config TEST_VMALLOC
2069 tristate "Test module for stress/performance analysis of vmalloc allocator"
2070 default n
2071 depends on MMU
2072 depends on m
2073 help
2074 This builds the "test_vmalloc" module that should be used for
2075 stress and performance analysis. So, any new change for vmalloc
2076 subsystem can be evaluated from performance and stability point
2077 of view.
2078
2079 If unsure, say N.
2080
3e2a4c18
KC
2081config TEST_USER_COPY
2082 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2083 depends on m
2084 help
2085 This builds the "test_user_copy" module that runs sanity checks
2086 on the copy_to/from_user infrastructure, making sure basic
2087 user/kernel boundary testing is working. If it fails to load,
2088 a regression has been detected in the user/kernel memory boundary
2089 protections.
2090
2091 If unsure, say N.
2092
64a8946b
AS
2093config TEST_BPF
2094 tristate "Test BPF filter functionality"
98920ba6 2095 depends on m && NET
64a8946b
AS
2096 help
2097 This builds the "test_bpf" module that runs various test vectors
2098 against the BPF interpreter or BPF JIT compiler depending on the
2099 current setting. This is in particular useful for BPF JIT compiler
2100 development, but also to run regression tests against changes in
3c731eba
AS
2101 the interpreter code. It also enables test stubs for eBPF maps and
2102 verifier used by user space verifier testsuite.
64a8946b
AS
2103
2104 If unsure, say N.
2105
509e56b3
MB
2106config TEST_BLACKHOLE_DEV
2107 tristate "Test blackhole netdev functionality"
2108 depends on m && NET
2109 help
2110 This builds the "test_blackhole_dev" module that validates the
2111 data path through this blackhole netdev.
2112
2113 If unsure, say N.
2114
dceeb3e7 2115config FIND_BIT_BENCHMARK
4441fca0 2116 tristate "Test find_bit functions"
4441fca0
YN
2117 help
2118 This builds the "test_find_bit" module that measure find_*_bit()
2119 functions performance.
2120
2121 If unsure, say N.
2122
0a8adf58
KC
2123config TEST_FIRMWARE
2124 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2125 depends on FW_LOADER
2126 help
2127 This builds the "test_firmware" module that creates a userspace
2128 interface for testing firmware loading. This can be used to
2129 control the triggering of firmware loading without needing an
2130 actual firmware-using device. The contents can be rechecked by
2131 userspace.
2132
2133 If unsure, say N.
2134
9308f2f9
LR
2135config TEST_SYSCTL
2136 tristate "sysctl test driver"
9308f2f9
LR
2137 depends on PROC_SYSCTL
2138 help
2139 This builds the "test_sysctl" module. This driver enables to test the
2140 proc sysctl interfaces available to drivers safely without affecting
2141 production knobs which might alter system functionality.
2142
2143 If unsure, say N.
2144
2cb80dbb 2145config SYSCTL_KUNIT_TEST
5f215aab 2146 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2cb80dbb 2147 depends on KUNIT
5f215aab 2148 default KUNIT_ALL_TESTS
2cb80dbb
IZ
2149 help
2150 This builds the proc sysctl unit test, which runs on boot.
2151 Tests the API contract and implementation correctness of sysctl.
2152 For more information on KUnit and unit tests in general please refer
2153 to the KUnit documentation in Documentation/dev-tools/kunit/.
2154
2155 If unsure, say N.
2156
ea2dd7c0 2157config LIST_KUNIT_TEST
5f215aab 2158 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
ea2dd7c0 2159 depends on KUNIT
5f215aab 2160 default KUNIT_ALL_TESTS
ea2dd7c0
DG
2161 help
2162 This builds the linked list KUnit test suite.
2163 It tests that the API and basic functionality of the list_head type
2164 and associated macros.
2165
2166 KUnit tests run during boot and output the results to the debug log
2167 in TAP format (http://testanything.org/). Only useful for kernel devs
2168 running the KUnit test harness, and not intended for inclusion into a
2169 production build.
2170
2171 For more information on KUnit and unit tests in general please refer
2172 to the KUnit documentation in Documentation/dev-tools/kunit/.
2173
2174 If unsure, say N.
2175
33d599f0
MV
2176config LINEAR_RANGES_TEST
2177 tristate "KUnit test for linear_ranges"
2178 depends on KUNIT
2179 select LINEAR_RANGES
2180 help
2181 This builds the linear_ranges unit test, which runs on boot.
2182 Tests the linear_ranges logic correctness.
2183 For more information on KUnit and unit tests in general please refer
2184 to the KUnit documentation in Documentation/dev-tools/kunit/.
2185
2186 If unsure, say N.
2187
e704f93a
DR
2188config TEST_UDELAY
2189 tristate "udelay test driver"
e704f93a
DR
2190 help
2191 This builds the "udelay_test" module that helps to make sure
2192 that udelay() is working properly.
2193
2194 If unsure, say N.
2195
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IM
2196config TEST_STATIC_KEYS
2197 tristate "Test static keys"
579e1acb
JB
2198 depends on m
2199 help
2bf9e0ab 2200 Test the static key interfaces.
579e1acb
JB
2201
2202 If unsure, say N.
2203
d9c6a72d
LR
2204config TEST_KMOD
2205 tristate "kmod stress tester"
d9c6a72d 2206 depends on m
d9c6a72d 2207 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2208 depends on BLOCK
d9c6a72d
LR
2209 select TEST_LKM
2210 select XFS_FS
2211 select TUN
2212 select BTRFS_FS
2213 help
2214 Test the kernel's module loading mechanism: kmod. kmod implements
2215 support to load modules using the Linux kernel's usermode helper.
2216 This test provides a series of tests against kmod.
2217
2218 Although technically you can either build test_kmod as a module or
2219 into the kernel we disallow building it into the kernel since
2220 it stress tests request_module() and this will very likely cause
2221 some issues by taking over precious threads available from other
2222 module load requests, ultimately this could be fatal.
2223
2224 To run tests run:
2225
2226 tools/testing/selftests/kmod/kmod.sh --help
2227
2228 If unsure, say N.
2229
e4dace36
FF
2230config TEST_DEBUG_VIRTUAL
2231 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2232 depends on DEBUG_VIRTUAL
2233 help
2234 Test the kernel's ability to detect incorrect calls to
2235 virt_to_phys() done against the non-linear part of the
2236 kernel's virtual address map.
2237
2238 If unsure, say N.
2239
ce76d938
AS
2240config TEST_MEMCAT_P
2241 tristate "Test memcat_p() helper function"
2242 help
2243 Test the memcat_p() helper for correctly merging two
2244 pointer arrays together.
2245
2246 If unsure, say N.
2247
a2818ee4
JL
2248config TEST_LIVEPATCH
2249 tristate "Test livepatching"
2250 default n
bae05437 2251 depends on DYNAMIC_DEBUG
a2818ee4
JL
2252 depends on LIVEPATCH
2253 depends on m
2254 help
2255 Test kernel livepatching features for correctness. The tests will
2256 load test modules that will be livepatched in various scenarios.
2257
2258 To run all the livepatching tests:
2259
2260 make -C tools/testing/selftests TARGETS=livepatch run_tests
2261
2262 Alternatively, individual tests may be invoked:
2263
2264 tools/testing/selftests/livepatch/test-callbacks.sh
2265 tools/testing/selftests/livepatch/test-livepatch.sh
2266 tools/testing/selftests/livepatch/test-shadow-vars.sh
2267
2268 If unsure, say N.
2269
0a020d41
JP
2270config TEST_OBJAGG
2271 tristate "Perform selftest on object aggreration manager"
2272 default n
2273 depends on OBJAGG
2274 help
2275 Enable this option to test object aggregation manager on boot
2276 (or module load).
2277
0a020d41 2278
50ceaa95
KC
2279config TEST_STACKINIT
2280 tristate "Test level of stack variable initialization"
2281 help
2282 Test if the kernel is zero-initializing stack variables and
2283 padding. Coverage is controlled by compiler flags,
2284 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2285 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2286
2287 If unsure, say N.
2288
5015a300
AP
2289config TEST_MEMINIT
2290 tristate "Test heap/page initialization"
2291 help
2292 Test if the kernel is zero-initializing heap and page allocations.
2293 This can be useful to test init_on_alloc and init_on_free features.
2294
2295 If unsure, say N.
2296
b2ef9f5a
RC
2297config TEST_HMM
2298 tristate "Test HMM (Heterogeneous Memory Management)"
2299 depends on TRANSPARENT_HUGEPAGE
2300 depends on DEVICE_PRIVATE
2301 select HMM_MIRROR
2302 select MMU_NOTIFIER
2303 help
2304 This is a pseudo device driver solely for testing HMM.
2305 Say M here if you want to build the HMM test module.
2306 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2307
2308 If unsure, say N.
2309
d3deafaa 2310endif # RUNTIME_TESTING_MENU
cc3fa840
RD
2311
2312config MEMTEST
2313 bool "Memtest"
a7f7f624 2314 help
cc3fa840
RD
2315 This option adds a kernel parameter 'memtest', which allows memtest
2316 to be set.
2317 memtest=0, mean disabled; -- default
2318 memtest=1, mean do 1 test pattern;
2319 ...
2320 memtest=17, mean do 17 test patterns.
2321 If you are unsure how to answer this question, answer N.
2322
21266be9 2323
06ec64b8 2324
af9ca6f9
BB
2325config HYPERV_TESTING
2326 bool "Microsoft Hyper-V driver testing"
2327 default n
2328 depends on HYPERV && DEBUG_FS
2329 help
2330 Select this option to enable Hyper-V vmbus testing.
2331
045f6d79
CD
2332endmenu # "Kernel Testing and Coverage"
2333
06ec64b8 2334endmenu # Kernel hacking