Commit | Line | Data |
---|---|---|
ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
06ec64b8 CH |
2 | menu "Kernel hacking" |
3 | ||
604ff0dc | 4 | menu "printk and dmesg options" |
1da177e4 LT |
5 | |
6 | config PRINTK_TIME | |
7 | bool "Show timing information on printks" | |
d3b8b6e5 | 8 | depends on PRINTK |
1da177e4 | 9 | help |
649e6ee3 KS |
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 | |
15ff2069 TH |
21 | config 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 | ||
a8cfdc68 OJ |
38 | config 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() |
a8cfdc68 OJ |
50 | usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT |
51 | option. | |
52 | ||
22eceb8b HG |
53 | config 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 | 64 | config MESSAGE_LOGLEVEL_DEFAULT |
5af5bcb8 MSB |
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 | ||
a8cfdc68 OJ |
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 | ||
604ff0dc DH |
79 | config 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 | ||
97 | config 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 |
604ff0dc DH |
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, | |
239a5791 GKH |
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. | |
604ff0dc DH |
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 | |
68d4b3df KK |
133 | flags : '=p' means the line is turned 'on' for printing |
134 | format : the format used for the debug statement | |
604ff0dc DH |
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 | ||
f8998c22 HH |
166 | See Documentation/admin-guide/dynamic-debug-howto.rst for additional |
167 | information. | |
604ff0dc | 168 | |
ceabef7d OZ |
169 | config 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 | ||
57f5677e RV |
180 | config 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 | ||
2b05bb75 CD |
189 | config 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 | ||
604ff0dc DH |
198 | endmenu # "printk and dmesg options" |
199 | ||
6dfc0665 DH |
200 | menu "Compile-time checks and compiler options" |
201 | ||
202 | config 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 |
6dfc0665 DH |
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 | ||
695afd3d SD |
215 | if DEBUG_INFO |
216 | ||
6dfc0665 DH |
217 | config DEBUG_INFO_REDUCED |
218 | bool "Reduce debugging information" | |
6dfc0665 DH |
219 | help |
220 | If you say Y here gcc is instructed to generate less debugging | |
221 | information for structure types. This means that tools that | |
222 | need full debugging information (like kgdb or systemtap) won't | |
223 | be happy. But if you merely need debugging information to | |
224 | resolve line numbers there is no loss. Advantage is that | |
225 | build directory object sizes shrink dramatically over a full | |
226 | DEBUG_INFO build and compile times are reduced too. | |
227 | Only works with newer gcc versions. | |
228 | ||
10e68b02 ND |
229 | config DEBUG_INFO_COMPRESSED |
230 | bool "Compressed debugging information" | |
10e68b02 | 231 | depends on $(cc-option,-gz=zlib) |
10e68b02 ND |
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 | ||
866ced95 AK |
244 | config DEBUG_INFO_SPLIT |
245 | bool "Produce split debuginfo in .dwo files" | |
9d937444 | 246 | depends on $(cc-option,-gsplit-dwarf) |
866ced95 AK |
247 | help |
248 | Generate debug info into separate .dwo files. This significantly | |
249 | reduces the build directory size for builds with DEBUG_INFO, | |
250 | because it stores the information only once on disk in .dwo | |
251 | files instead of multiple times in object files and executables. | |
252 | In addition the debug information is also compressed. | |
253 | ||
254 | Requires recent gcc (4.7+) and recent gdb/binutils. | |
255 | Any tool that packages or reads debug information would need | |
256 | to know about the .dwo files and include them. | |
257 | Incompatible with older versions of ccache. | |
258 | ||
a66049e2 ND |
259 | choice |
260 | prompt "DWARF version" | |
261 | help | |
262 | Which version of DWARF debug info to emit. | |
263 | ||
264 | config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT | |
265 | bool "Rely on the toolchain's implicit default DWARF version" | |
266 | help | |
267 | The implicit default version of DWARF debug info produced by a | |
268 | toolchain changes over time. | |
269 | ||
270 | This can break consumers of the debug info that haven't upgraded to | |
271 | support newer revisions, and prevent testing newer versions, but | |
272 | those should be less common scenarios. | |
273 | ||
274 | If unsure, say Y. | |
275 | ||
bfaf2dd3 | 276 | config DEBUG_INFO_DWARF4 |
a66049e2 | 277 | bool "Generate DWARF Version 4 debuginfo" |
bfaf2dd3 | 278 | help |
a66049e2 ND |
279 | Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. |
280 | ||
281 | If you have consumers of DWARF debug info that are not ready for | |
282 | newer revisions of DWARF, you may wish to choose this or have your | |
283 | config select this. | |
284 | ||
98cd6f52 ND |
285 | config DEBUG_INFO_DWARF5 |
286 | bool "Generate DWARF Version 5 debuginfo" | |
287 | depends on GCC_VERSION >= 50000 || CC_IS_CLANG | |
288 | depends on CC_IS_GCC || $(success,$(srctree)/scripts/test_dwarf5_support.sh $(CC) $(CLANG_FLAGS)) | |
289 | depends on !DEBUG_INFO_BTF | |
bfaf2dd3 | 290 | help |
98cd6f52 ND |
291 | Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc |
292 | 5.0+ accepts the -gdwarf-5 flag but only had partial support for some | |
293 | draft features until 7.0), and gdb 8.0+. | |
294 | ||
295 | Changes to the structure of debug info in Version 5 allow for around | |
296 | 15-18% savings in resulting image and debug info section sizes as | |
297 | compared to DWARF Version 4. DWARF Version 5 standardizes previous | |
298 | extensions such as accelerators for symbol indexing and the format | |
299 | for fission (.dwo/.dwp) files. Users may not want to select this | |
300 | config if they rely on tooling that has not yet been updated to | |
301 | support DWARF Version 5. | |
302 | ||
a66049e2 | 303 | endchoice # "DWARF version" |
bfaf2dd3 | 304 | |
e83b9f55 AN |
305 | config DEBUG_INFO_BTF |
306 | bool "Generate BTF typeinfo" | |
7d32e693 SB |
307 | depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED |
308 | depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST | |
e83b9f55 AN |
309 | help |
310 | Generate deduplicated BTF type information from DWARF debug info. | |
311 | Turning this on expects presence of pahole tool, which will convert | |
312 | DWARF type info into equivalent deduplicated BTF type info. | |
313 | ||
5f9ae91f AN |
314 | config PAHOLE_HAS_SPLIT_BTF |
315 | def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119") | |
316 | ||
317 | config DEBUG_INFO_BTF_MODULES | |
318 | def_bool y | |
319 | depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF | |
320 | help | |
321 | Generate compact split BTF type information for kernel modules. | |
322 | ||
3ee7b3fa JK |
323 | config GDB_SCRIPTS |
324 | bool "Provide GDB scripts for kernel debugging" | |
3ee7b3fa JK |
325 | help |
326 | This creates the required links to GDB helper scripts in the | |
327 | build directory. If you load vmlinux into gdb, the helper | |
328 | scripts will be automatically imported by gdb as well, and | |
329 | additional functions are available to analyze a Linux kernel | |
700199b0 AP |
330 | instance. See Documentation/dev-tools/gdb-kernel-debugging.rst |
331 | for further details. | |
3ee7b3fa | 332 | |
695afd3d SD |
333 | endif # DEBUG_INFO |
334 | ||
35bb5b1e | 335 | config FRAME_WARN |
a83e4ca2 | 336 | int "Warn for stack frames larger than" |
35bb5b1e | 337 | range 0 8192 |
0e07f663 | 338 | default 2048 if GCC_PLUGIN_LATENT_ENTROPY |
432654df HD |
339 | default 1280 if (!64BIT && PARISC) |
340 | default 1024 if (!64BIT && !PARISC) | |
35bb5b1e AK |
341 | default 2048 if 64BIT |
342 | help | |
343 | Tell gcc to warn at build time for stack frames larger than this. | |
344 | Setting this too low will cause a lot of warnings. | |
345 | Setting it to 0 disables the warning. | |
35bb5b1e | 346 | |
99657c78 RD |
347 | config STRIP_ASM_SYMS |
348 | bool "Strip assembler-generated symbols during link" | |
349 | default n | |
350 | help | |
351 | Strip internal assembler-generated symbols during a link (symbols | |
352 | that look like '.Lxxx') so they don't pollute the output of | |
353 | get_wchan() and suchlike. | |
354 | ||
1873e870 | 355 | config READABLE_ASM |
68d4b3df KK |
356 | bool "Generate readable assembler code" |
357 | depends on DEBUG_KERNEL | |
bf4735a4 | 358 | help |
68d4b3df KK |
359 | Disable some compiler optimizations that tend to generate human unreadable |
360 | assembler output. This may make the kernel slightly slower, but it helps | |
361 | to keep kernel developers who have to stare a lot at assembler listings | |
362 | sane. | |
bf4735a4 | 363 | |
e949f4c2 MY |
364 | config HEADERS_INSTALL |
365 | bool "Install uapi headers to usr/include" | |
bf4735a4 DM |
366 | depends on !UML |
367 | help | |
e949f4c2 MY |
368 | This option will install uapi headers (headers exported to user-space) |
369 | into the usr/include directory for use during the kernel build. | |
370 | This is unneeded for building the kernel itself, but needed for some | |
371 | user-space program samples. It is also needed by some features such | |
372 | as uapi header sanity checks. | |
373 | ||
91341d4b SR |
374 | config DEBUG_SECTION_MISMATCH |
375 | bool "Enable full Section mismatch analysis" | |
91341d4b SR |
376 | help |
377 | The section mismatch analysis checks if there are illegal | |
378 | references from one section to another section. | |
e809ab01 MW |
379 | During linktime or runtime, some sections are dropped; |
380 | any use of code/data previously in these sections would | |
91341d4b | 381 | most likely result in an oops. |
e809ab01 | 382 | In the code, functions and variables are annotated with |
0db0628d | 383 | __init,, etc. (see the full list in include/linux/init.h), |
d6fbfa4f | 384 | which results in the code/data being placed in specific sections. |
e809ab01 MW |
385 | The section mismatch analysis is always performed after a full |
386 | kernel build, and enabling this option causes the following | |
b7dca6dd | 387 | additional step to occur: |
e809ab01 MW |
388 | - Add the option -fno-inline-functions-called-once to gcc commands. |
389 | When inlining a function annotated with __init in a non-init | |
390 | function, we would lose the section information and thus | |
91341d4b | 391 | the analysis would not catch the illegal reference. |
e809ab01 MW |
392 | This option tells gcc to inline less (but it does result in |
393 | a larger kernel). | |
91341d4b | 394 | |
47490ec1 NB |
395 | config SECTION_MISMATCH_WARN_ONLY |
396 | bool "Make section mismatch errors non-fatal" | |
397 | default y | |
398 | help | |
399 | If you say N here, the build process will fail if there are any | |
400 | section mismatch, instead of just throwing warnings. | |
401 | ||
402 | If unsure, say Y. | |
403 | ||
09c60546 FT |
404 | config DEBUG_FORCE_FUNCTION_ALIGN_32B |
405 | bool "Force all function address 32B aligned" if EXPERT | |
406 | help | |
407 | There are cases that a commit from one domain changes the function | |
408 | address alignment of other domains, and cause magic performance | |
409 | bump (regression or improvement). Enable this option will help to | |
410 | verify if the bump is caused by function alignment changes, while | |
411 | it will slightly increase the kernel size and affect icache usage. | |
412 | ||
413 | It is mainly for debug and performance tuning use. | |
414 | ||
6dfc0665 DH |
415 | # |
416 | # Select this config option from the architecture Kconfig, if it | |
417 | # is preferred to always offer frame pointers as a config | |
418 | # option on the architecture (regardless of KERNEL_DEBUG): | |
419 | # | |
420 | config ARCH_WANT_FRAME_POINTERS | |
421 | bool | |
f346f4b3 | 422 | |
6dfc0665 DH |
423 | config FRAME_POINTER |
424 | bool "Compile the kernel with frame pointers" | |
a687a533 | 425 | depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS |
6dfc0665 | 426 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
a304e1b8 | 427 | help |
6dfc0665 DH |
428 | If you say Y here the resulting kernel image will be slightly |
429 | larger and slower, but it gives very useful debugging information | |
430 | in case of kernel bugs. (precise oopses/stacktraces/warnings) | |
a304e1b8 | 431 | |
b9ab5ebb JP |
432 | config STACK_VALIDATION |
433 | bool "Compile-time stack metadata validation" | |
434 | depends on HAVE_STACK_VALIDATION | |
435 | default n | |
436 | help | |
437 | Add compile-time checks to validate stack metadata, including frame | |
438 | pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure | |
439 | that runtime stack traces are more reliable. | |
440 | ||
ee9f8fce | 441 | This is also a prerequisite for generation of ORC unwind data, which |
11af8474 | 442 | is needed for CONFIG_UNWINDER_ORC. |
ee9f8fce | 443 | |
b9ab5ebb JP |
444 | For more information, see |
445 | tools/objtool/Documentation/stack-validation.txt. | |
446 | ||
6804c1af PZ |
447 | config VMLINUX_VALIDATION |
448 | bool | |
449 | depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT | |
450 | default y | |
451 | ||
6dfc0665 DH |
452 | config DEBUG_FORCE_WEAK_PER_CPU |
453 | bool "Force weak per-cpu definitions" | |
454 | depends on DEBUG_KERNEL | |
8446f1d3 | 455 | help |
6dfc0665 DH |
456 | s390 and alpha require percpu variables in modules to be |
457 | defined weak to work around addressing range issue which | |
458 | puts the following two restrictions on percpu variable | |
459 | definitions. | |
8446f1d3 | 460 | |
6dfc0665 DH |
461 | 1. percpu symbols must be unique whether static or not |
462 | 2. percpu variables can't be defined inside a function | |
8446f1d3 | 463 | |
6dfc0665 DH |
464 | To ensure that generic code follows the above rules, this |
465 | option forces all percpu variables to be defined as weak. | |
5f329089 | 466 | |
6dfc0665 | 467 | endmenu # "Compiler options" |
8446f1d3 | 468 | |
6210b640 CD |
469 | menu "Generic Kernel Debugging Instruments" |
470 | ||
6dfc0665 DH |
471 | config MAGIC_SYSRQ |
472 | bool "Magic SysRq key" | |
473 | depends on !UML | |
474 | help | |
475 | If you say Y here, you will have some control over the system even | |
476 | if the system crashes for example during kernel debugging (e.g., you | |
477 | will be able to flush the buffer cache to disk, reboot the system | |
478 | immediately or dump some status information). This is accomplished | |
479 | by pressing various keys while holding SysRq (Alt+PrintScreen). It | |
480 | also works on a serial console (on PC hardware at least), if you | |
481 | send a BREAK and then within 5 seconds a command keypress. The | |
f8998c22 HH |
482 | keys are documented in <file:Documentation/admin-guide/sysrq.rst>. |
483 | Don't say Y unless you really know what this hack does. | |
8446f1d3 | 484 | |
8eaede49 BH |
485 | config MAGIC_SYSRQ_DEFAULT_ENABLE |
486 | hex "Enable magic SysRq key functions by default" | |
487 | depends on MAGIC_SYSRQ | |
488 | default 0x1 | |
489 | help | |
490 | Specifies which SysRq key functions are enabled by default. | |
491 | This may be set to 1 or 0 to enable or disable them all, or | |
f8998c22 | 492 | to a bitmask as described in Documentation/admin-guide/sysrq.rst. |
8eaede49 | 493 | |
732dbf3a FF |
494 | config MAGIC_SYSRQ_SERIAL |
495 | bool "Enable magic SysRq key over serial" | |
496 | depends on MAGIC_SYSRQ | |
497 | default y | |
498 | help | |
499 | Many embedded boards have a disconnected TTL level serial which can | |
500 | generate some garbage that can lead to spurious false sysrq detects. | |
501 | This option allows you to decide whether you want to enable the | |
502 | magic SysRq key. | |
503 | ||
68af4317 DS |
504 | config MAGIC_SYSRQ_SERIAL_SEQUENCE |
505 | string "Char sequence that enables magic SysRq over serial" | |
506 | depends on MAGIC_SYSRQ_SERIAL | |
507 | default "" | |
508 | help | |
509 | Specifies a sequence of characters that can follow BREAK to enable | |
510 | SysRq on a serial console. | |
511 | ||
d3394b3d DS |
512 | If unsure, leave an empty string and the option will not be enabled. |
513 | ||
ec29a5c1 CD |
514 | config DEBUG_FS |
515 | bool "Debug Filesystem" | |
516 | help | |
517 | debugfs is a virtual file system that kernel developers use to put | |
518 | debugging files into. Enable this option to be able to read and | |
519 | write to these files. | |
520 | ||
521 | For detailed documentation on the debugfs API, see | |
522 | Documentation/filesystems/. | |
523 | ||
524 | If unsure, say N. | |
525 | ||
a24c6f7b PE |
526 | choice |
527 | prompt "Debugfs default access" | |
528 | depends on DEBUG_FS | |
529 | default DEBUG_FS_ALLOW_ALL | |
530 | help | |
531 | This selects the default access restrictions for debugfs. | |
532 | It can be overridden with kernel command line option | |
533 | debugfs=[on,no-mount,off]. The restrictions apply for API access | |
534 | and filesystem registration. | |
535 | ||
536 | config DEBUG_FS_ALLOW_ALL | |
537 | bool "Access normal" | |
538 | help | |
539 | No restrictions apply. Both API and filesystem registration | |
540 | is on. This is the normal default operation. | |
541 | ||
542 | config DEBUG_FS_DISALLOW_MOUNT | |
543 | bool "Do not register debugfs as filesystem" | |
544 | help | |
545 | The API is open but filesystem is not loaded. Clients can still do | |
546 | their work and read with debug tools that do not need | |
547 | debugfs filesystem. | |
548 | ||
549 | config DEBUG_FS_ALLOW_NONE | |
550 | bool "No access" | |
551 | help | |
552 | Access is off. Clients get -PERM when trying to create nodes in | |
553 | debugfs tree and debugfs is not registered as a filesystem. | |
554 | Client can then back-off or continue without debugfs access. | |
555 | ||
556 | endchoice | |
557 | ||
6210b640 | 558 | source "lib/Kconfig.kgdb" |
6210b640 | 559 | source "lib/Kconfig.ubsan" |
2645d432 | 560 | source "lib/Kconfig.kcsan" |
6210b640 CD |
561 | |
562 | endmenu | |
563 | ||
f346f4b3 AB |
564 | config DEBUG_KERNEL |
565 | bool "Kernel debugging" | |
fef2c9bc | 566 | help |
f346f4b3 AB |
567 | Say Y here if you are developing drivers or trying to debug and |
568 | identify kernel problems. | |
fef2c9bc | 569 | |
c66d7a27 SK |
570 | config DEBUG_MISC |
571 | bool "Miscellaneous debug code" | |
572 | default DEBUG_KERNEL | |
573 | depends on DEBUG_KERNEL | |
574 | help | |
575 | Say Y here if you need to enable miscellaneous debug code that should | |
576 | be under a more specific debug option but isn't. | |
577 | ||
578 | ||
0610c8a8 | 579 | menu "Memory Debugging" |
fef2c9bc | 580 | |
8636a1f9 | 581 | source "mm/Kconfig.debug" |
fef2c9bc | 582 | |
0610c8a8 DH |
583 | config DEBUG_OBJECTS |
584 | bool "Debug object operations" | |
585 | depends on DEBUG_KERNEL | |
9c44bc03 | 586 | help |
0610c8a8 DH |
587 | If you say Y here, additional code will be inserted into the |
588 | kernel to track the life time of various objects and validate | |
589 | the operations on those objects. | |
9c44bc03 | 590 | |
0610c8a8 DH |
591 | config DEBUG_OBJECTS_SELFTEST |
592 | bool "Debug objects selftest" | |
593 | depends on DEBUG_OBJECTS | |
594 | help | |
595 | This enables the selftest of the object debug code. | |
9c44bc03 | 596 | |
0610c8a8 DH |
597 | config DEBUG_OBJECTS_FREE |
598 | bool "Debug objects in freed memory" | |
599 | depends on DEBUG_OBJECTS | |
600 | help | |
601 | This enables checks whether a k/v free operation frees an area | |
602 | which contains an object which has not been deactivated | |
603 | properly. This can make kmalloc/kfree-intensive workloads | |
604 | much slower. | |
3ac7fe5a | 605 | |
c6f3a97f TG |
606 | config DEBUG_OBJECTS_TIMERS |
607 | bool "Debug timer objects" | |
608 | depends on DEBUG_OBJECTS | |
609 | help | |
610 | If you say Y here, additional code will be inserted into the | |
611 | timer routines to track the life time of timer objects and | |
612 | validate the timer operations. | |
613 | ||
dc186ad7 TG |
614 | config DEBUG_OBJECTS_WORK |
615 | bool "Debug work objects" | |
616 | depends on DEBUG_OBJECTS | |
617 | help | |
618 | If you say Y here, additional code will be inserted into the | |
619 | work queue routines to track the life time of work objects and | |
620 | validate the work operations. | |
621 | ||
551d55a9 MD |
622 | config DEBUG_OBJECTS_RCU_HEAD |
623 | bool "Debug RCU callbacks objects" | |
fc2ecf7e | 624 | depends on DEBUG_OBJECTS |
551d55a9 MD |
625 | help |
626 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). | |
627 | ||
e2852ae8 TH |
628 | config DEBUG_OBJECTS_PERCPU_COUNTER |
629 | bool "Debug percpu counter objects" | |
630 | depends on DEBUG_OBJECTS | |
631 | help | |
632 | If you say Y here, additional code will be inserted into the | |
633 | percpu counter routines to track the life time of percpu counter | |
634 | objects and validate the percpu counter operations. | |
635 | ||
3ae70205 IM |
636 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
637 | int "debug_objects bootup default value (0-1)" | |
68d4b3df KK |
638 | range 0 1 |
639 | default "1" | |
640 | depends on DEBUG_OBJECTS | |
641 | help | |
642 | Debug objects boot parameter default value | |
3ae70205 | 643 | |
1da177e4 | 644 | config DEBUG_SLAB |
4a2f0acf | 645 | bool "Debug slab memory allocations" |
4675ff05 | 646 | depends on DEBUG_KERNEL && SLAB |
1da177e4 LT |
647 | help |
648 | Say Y here to have the kernel do limited verification on memory | |
649 | allocation as well as poisoning memory on free to catch use of freed | |
650 | memory. This can make kmalloc/kfree-intensive workloads much slower. | |
651 | ||
f0630fff CL |
652 | config SLUB_DEBUG_ON |
653 | bool "SLUB debugging on by default" | |
4675ff05 | 654 | depends on SLUB && SLUB_DEBUG |
f0630fff CL |
655 | default n |
656 | help | |
657 | Boot with debugging on by default. SLUB boots by default with | |
658 | the runtime debug capabilities switched off. Enabling this is | |
659 | equivalent to specifying the "slub_debug" parameter on boot. | |
660 | There is no support for more fine grained debug control like | |
661 | possible with slub_debug=xxx. SLUB debugging may be switched | |
662 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying | |
663 | "slub_debug=-". | |
664 | ||
8ff12cfc CL |
665 | config SLUB_STATS |
666 | default n | |
667 | bool "Enable SLUB performance statistics" | |
ab4d5ed5 | 668 | depends on SLUB && SYSFS |
8ff12cfc CL |
669 | help |
670 | SLUB statistics are useful to debug SLUBs allocation behavior in | |
671 | order find ways to optimize the allocator. This should never be | |
672 | enabled for production use since keeping statistics slows down | |
673 | the allocator by a few percentage points. The slabinfo command | |
674 | supports the determination of the most active slabs to figure | |
675 | out which slabs are relevant to a particular load. | |
676 | Try running: slabinfo -DA | |
677 | ||
b69ec42b CM |
678 | config HAVE_DEBUG_KMEMLEAK |
679 | bool | |
680 | ||
3bba00d7 CM |
681 | config DEBUG_KMEMLEAK |
682 | bool "Kernel memory leak detector" | |
525c1f92 | 683 | depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK |
79e0d9bd | 684 | select DEBUG_FS |
3bba00d7 CM |
685 | select STACKTRACE if STACKTRACE_SUPPORT |
686 | select KALLSYMS | |
b60e26a2 | 687 | select CRC32 |
3bba00d7 CM |
688 | help |
689 | Say Y here if you want to enable the memory leak | |
690 | detector. The memory allocation/freeing is traced in a way | |
691 | similar to the Boehm's conservative garbage collector, the | |
692 | difference being that the orphan objects are not freed but | |
693 | only shown in /sys/kernel/debug/kmemleak. Enabling this | |
694 | feature will introduce an overhead to memory | |
700199b0 | 695 | allocations. See Documentation/dev-tools/kmemleak.rst for more |
3bba00d7 CM |
696 | details. |
697 | ||
0610c8a8 DH |
698 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
699 | of finding leaks due to the slab objects poisoning. | |
700 | ||
701 | In order to access the kmemleak file, debugfs needs to be | |
702 | mounted (usually at /sys/kernel/debug). | |
703 | ||
c5665868 CM |
704 | config DEBUG_KMEMLEAK_MEM_POOL_SIZE |
705 | int "Kmemleak memory pool size" | |
0610c8a8 | 706 | depends on DEBUG_KMEMLEAK |
c59180ae | 707 | range 200 1000000 |
b751c52b | 708 | default 16000 |
0610c8a8 DH |
709 | help |
710 | Kmemleak must track all the memory allocations to avoid | |
711 | reporting false positives. Since memory may be allocated or | |
c5665868 CM |
712 | freed before kmemleak is fully initialised, use a static pool |
713 | of metadata objects to track such callbacks. After kmemleak is | |
714 | fully initialised, this memory pool acts as an emergency one | |
715 | if slab allocations fail. | |
0610c8a8 DH |
716 | |
717 | config DEBUG_KMEMLEAK_TEST | |
718 | tristate "Simple test for the kernel memory leak detector" | |
719 | depends on DEBUG_KMEMLEAK && m | |
720 | help | |
721 | This option enables a module that explicitly leaks memory. | |
722 | ||
723 | If unsure, say N. | |
724 | ||
725 | config DEBUG_KMEMLEAK_DEFAULT_OFF | |
726 | bool "Default kmemleak to off" | |
727 | depends on DEBUG_KMEMLEAK | |
728 | help | |
729 | Say Y here to disable kmemleak by default. It can then be enabled | |
730 | on the command line via kmemleak=on. | |
731 | ||
d53ce042 SK |
732 | config DEBUG_KMEMLEAK_AUTO_SCAN |
733 | bool "Enable kmemleak auto scan thread on boot up" | |
734 | default y | |
735 | depends on DEBUG_KMEMLEAK | |
736 | help | |
737 | Depending on the cpu, kmemleak scan may be cpu intensive and can | |
738 | stall user tasks at times. This option enables/disables automatic | |
739 | kmemleak scan at boot up. | |
740 | ||
741 | Say N here to disable kmemleak auto scan thread to stop automatic | |
742 | scanning. Disabling this option disables automatic reporting of | |
743 | memory leaks. | |
744 | ||
745 | If unsure, say Y. | |
746 | ||
0610c8a8 DH |
747 | config DEBUG_STACK_USAGE |
748 | bool "Stack utilization instrumentation" | |
6c31da34 | 749 | depends on DEBUG_KERNEL && !IA64 |
0610c8a8 DH |
750 | help |
751 | Enables the display of the minimum amount of free stack which each | |
752 | task has ever had available in the sysrq-T and sysrq-P debug output. | |
753 | ||
754 | This option will slow down process creation somewhat. | |
755 | ||
dc9b9638 CD |
756 | config SCHED_STACK_END_CHECK |
757 | bool "Detect stack corruption on calls to schedule()" | |
758 | depends on DEBUG_KERNEL | |
759 | default n | |
760 | help | |
761 | This option checks for a stack overrun on calls to schedule(). | |
762 | If the stack end location is found to be over written always panic as | |
763 | the content of the corrupted region can no longer be trusted. | |
764 | This is to ensure no erroneous behaviour occurs which could result in | |
765 | data corruption or a sporadic crash at a later stage once the region | |
766 | is examined. The runtime overhead introduced is minimal. | |
767 | ||
399145f9 AK |
768 | config ARCH_HAS_DEBUG_VM_PGTABLE |
769 | bool | |
770 | help | |
771 | An architecture should select this when it can successfully | |
772 | build and run DEBUG_VM_PGTABLE. | |
773 | ||
0610c8a8 DH |
774 | config DEBUG_VM |
775 | bool "Debug VM" | |
776 | depends on DEBUG_KERNEL | |
777 | help | |
778 | Enable this to turn on extended checks in the virtual-memory system | |
68d4b3df | 779 | that may impact performance. |
0610c8a8 DH |
780 | |
781 | If unsure, say N. | |
782 | ||
4f115147 DB |
783 | config DEBUG_VM_VMACACHE |
784 | bool "Debug VMA caching" | |
785 | depends on DEBUG_VM | |
786 | help | |
787 | Enable this to turn on VMA caching debug information. Doing so | |
788 | can cause significant overhead, so only enable it in non-production | |
789 | environments. | |
790 | ||
791 | If unsure, say N. | |
792 | ||
0610c8a8 DH |
793 | config DEBUG_VM_RB |
794 | bool "Debug VM red-black trees" | |
795 | depends on DEBUG_VM | |
796 | help | |
a663dad6 | 797 | Enable VM red-black tree debugging information and extra validations. |
0610c8a8 DH |
798 | |
799 | If unsure, say N. | |
800 | ||
95ad9755 KS |
801 | config DEBUG_VM_PGFLAGS |
802 | bool "Debug page-flags operations" | |
803 | depends on DEBUG_VM | |
804 | help | |
805 | Enables extra validation on page flags operations. | |
806 | ||
807 | If unsure, say N. | |
808 | ||
399145f9 AK |
809 | config DEBUG_VM_PGTABLE |
810 | bool "Debug arch page table for semantics compliance" | |
811 | depends on MMU | |
812 | depends on ARCH_HAS_DEBUG_VM_PGTABLE | |
813 | default y if DEBUG_VM | |
814 | help | |
815 | This option provides a debug method which can be used to test | |
816 | architecture page table helper functions on various platforms in | |
817 | verifying if they comply with expected generic MM semantics. This | |
818 | will help architecture code in making sure that any changes or | |
819 | new additions of these helpers still conform to expected | |
820 | semantics of the generic MM. Platforms will have to opt in for | |
821 | this through ARCH_HAS_DEBUG_VM_PGTABLE. | |
822 | ||
823 | If unsure, say N. | |
824 | ||
fa5b6ec9 LA |
825 | config ARCH_HAS_DEBUG_VIRTUAL |
826 | bool | |
827 | ||
0610c8a8 DH |
828 | config DEBUG_VIRTUAL |
829 | bool "Debug VM translations" | |
fa5b6ec9 | 830 | depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL |
0610c8a8 DH |
831 | help |
832 | Enable some costly sanity checks in virtual to page code. This can | |
833 | catch mistakes with virt_to_page() and friends. | |
834 | ||
835 | If unsure, say N. | |
836 | ||
837 | config DEBUG_NOMMU_REGIONS | |
838 | bool "Debug the global anon/private NOMMU mapping region tree" | |
839 | depends on DEBUG_KERNEL && !MMU | |
840 | help | |
841 | This option causes the global tree of anonymous and private mapping | |
842 | regions to be regularly checked for invalid topology. | |
843 | ||
844 | config DEBUG_MEMORY_INIT | |
845 | bool "Debug memory initialisation" if EXPERT | |
846 | default !EXPERT | |
847 | help | |
848 | Enable this for additional checks during memory initialisation. | |
849 | The sanity checks verify aspects of the VM such as the memory model | |
850 | and other information provided by the architecture. Verbose | |
851 | information will be printed at KERN_DEBUG loglevel depending | |
852 | on the mminit_loglevel= command-line option. | |
853 | ||
854 | If unsure, say Y | |
855 | ||
856 | config MEMORY_NOTIFIER_ERROR_INJECT | |
857 | tristate "Memory hotplug notifier error injection module" | |
858 | depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION | |
859 | help | |
860 | This option provides the ability to inject artificial errors to | |
861 | memory hotplug notifier chain callbacks. It is controlled through | |
862 | debugfs interface under /sys/kernel/debug/notifier-error-inject/memory | |
863 | ||
864 | If the notifier call chain should be failed with some events | |
865 | notified, write the error code to "actions/<notifier event>/error". | |
866 | ||
867 | Example: Inject memory hotplug offline error (-12 == -ENOMEM) | |
868 | ||
869 | # cd /sys/kernel/debug/notifier-error-inject/memory | |
870 | # echo -12 > actions/MEM_GOING_OFFLINE/error | |
871 | # echo offline > /sys/devices/system/memory/memoryXXX/state | |
872 | bash: echo: write error: Cannot allocate memory | |
873 | ||
874 | To compile this code as a module, choose M here: the module will | |
875 | be called memory-notifier-error-inject. | |
876 | ||
877 | If unsure, say N. | |
878 | ||
879 | config DEBUG_PER_CPU_MAPS | |
880 | bool "Debug access to per_cpu maps" | |
881 | depends on DEBUG_KERNEL | |
882 | depends on SMP | |
883 | help | |
884 | Say Y to verify that the per_cpu map being accessed has | |
885 | been set up. This adds a fair amount of code to kernel memory | |
886 | and decreases performance. | |
887 | ||
888 | Say N if unsure. | |
889 | ||
6e799cb6 TG |
890 | config DEBUG_KMAP_LOCAL |
891 | bool "Debug kmap_local temporary mappings" | |
892 | depends on DEBUG_KERNEL && KMAP_LOCAL | |
893 | help | |
894 | This option enables additional error checking for the kmap_local | |
895 | infrastructure. Disable for production use. | |
896 | ||
0e91a0c6 TG |
897 | config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
898 | bool | |
899 | ||
900 | config DEBUG_KMAP_LOCAL_FORCE_MAP | |
901 | bool "Enforce kmap_local temporary mappings" | |
902 | depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP | |
903 | select KMAP_LOCAL | |
904 | select DEBUG_KMAP_LOCAL | |
905 | help | |
906 | This option enforces temporary mappings through the kmap_local | |
907 | mechanism for non-highmem pages and on non-highmem systems. | |
908 | Disable this for production systems! | |
909 | ||
0610c8a8 DH |
910 | config DEBUG_HIGHMEM |
911 | bool "Highmem debugging" | |
912 | depends on DEBUG_KERNEL && HIGHMEM | |
0e91a0c6 | 913 | select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
6e799cb6 | 914 | select DEBUG_KMAP_LOCAL |
0610c8a8 | 915 | help |
b1357c9f GU |
916 | This option enables additional error checking for high memory |
917 | systems. Disable for production systems. | |
0610c8a8 DH |
918 | |
919 | config HAVE_DEBUG_STACKOVERFLOW | |
920 | bool | |
921 | ||
922 | config DEBUG_STACKOVERFLOW | |
923 | bool "Check for stack overflows" | |
924 | depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW | |
a7f7f624 | 925 | help |
0610c8a8 | 926 | Say Y here if you want to check for overflows of kernel, IRQ |
edb0ec07 | 927 | and exception stacks (if your architecture uses them). This |
0610c8a8 DH |
928 | option will show detailed messages if free stack space drops |
929 | below a certain limit. | |
930 | ||
931 | These kinds of bugs usually occur when call-chains in the | |
932 | kernel get too deep, especially when interrupts are | |
933 | involved. | |
934 | ||
935 | Use this in cases where you see apparently random memory | |
936 | corruption, especially if it appears in 'struct thread_info' | |
937 | ||
938 | If in doubt, say "N". | |
939 | ||
0b24becc | 940 | source "lib/Kconfig.kasan" |
0ce20dd8 | 941 | source "lib/Kconfig.kfence" |
0b24becc | 942 | |
0610c8a8 DH |
943 | endmenu # "Memory Debugging" |
944 | ||
a304e1b8 DW |
945 | config DEBUG_SHIRQ |
946 | bool "Debug shared IRQ handlers" | |
0244ad00 | 947 | depends on DEBUG_KERNEL |
a304e1b8 | 948 | help |
0a2fae2a WS |
949 | Enable this to generate a spurious interrupt just before a shared |
950 | interrupt handler is deregistered (generating one when registering | |
951 | is currently disabled). Drivers need to handle this correctly. Some | |
952 | don't and need to be caught. | |
a304e1b8 | 953 | |
f43a289d CD |
954 | menu "Debug Oops, Lockups and Hangs" |
955 | ||
956 | config PANIC_ON_OOPS | |
957 | bool "Panic on Oops" | |
958 | help | |
959 | Say Y here to enable the kernel to panic when it oopses. This | |
960 | has the same effect as setting oops=panic on the kernel command | |
961 | line. | |
962 | ||
963 | This feature is useful to ensure that the kernel does not do | |
964 | anything erroneous after an oops which could result in data | |
965 | corruption or other issues. | |
966 | ||
967 | Say N if unsure. | |
968 | ||
969 | config PANIC_ON_OOPS_VALUE | |
970 | int | |
971 | range 0 1 | |
972 | default 0 if !PANIC_ON_OOPS | |
973 | default 1 if PANIC_ON_OOPS | |
974 | ||
975 | config PANIC_TIMEOUT | |
976 | int "panic timeout" | |
977 | default 0 | |
978 | help | |
9d5b134f | 979 | Set the timeout value (in seconds) until a reboot occurs when |
f43a289d CD |
980 | the kernel panics. If n = 0, then we wait forever. A timeout |
981 | value n > 0 will wait n seconds before rebooting, while a timeout | |
982 | value n < 0 will reboot immediately. | |
92aef8fb | 983 | |
58687acb | 984 | config LOCKUP_DETECTOR |
05a4a952 NP |
985 | bool |
986 | ||
987 | config SOFTLOCKUP_DETECTOR | |
988 | bool "Detect Soft Lockups" | |
dea20a3f | 989 | depends on DEBUG_KERNEL && !S390 |
05a4a952 | 990 | select LOCKUP_DETECTOR |
8446f1d3 | 991 | help |
58687acb | 992 | Say Y here to enable the kernel to act as a watchdog to detect |
05a4a952 | 993 | soft lockups. |
58687acb DZ |
994 | |
995 | Softlockups are bugs that cause the kernel to loop in kernel | |
5f329089 | 996 | mode for more than 20 seconds, without giving other tasks a |
58687acb DZ |
997 | chance to run. The current stack trace is displayed upon |
998 | detection and the system will stay locked up. | |
8446f1d3 | 999 | |
5f00ae0d RD |
1000 | config BOOTPARAM_SOFTLOCKUP_PANIC |
1001 | bool "Panic (Reboot) On Soft Lockups" | |
1002 | depends on SOFTLOCKUP_DETECTOR | |
1003 | help | |
1004 | Say Y here to enable the kernel to panic on "soft lockups", | |
1005 | which are bugs that cause the kernel to loop in kernel | |
1006 | mode for more than 20 seconds (configurable using the watchdog_thresh | |
1007 | sysctl), without giving other tasks a chance to run. | |
1008 | ||
1009 | The panic can be used in combination with panic_timeout, | |
1010 | to cause the system to reboot automatically after a | |
1011 | lockup has been detected. This feature is useful for | |
1012 | high-availability systems that have uptime guarantees and | |
1013 | where a lockup must be resolved ASAP. | |
1014 | ||
1015 | Say N if unsure. | |
1016 | ||
1017 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE | |
1018 | int | |
1019 | depends on SOFTLOCKUP_DETECTOR | |
1020 | range 0 1 | |
1021 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC | |
1022 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC | |
1023 | ||
05a4a952 NP |
1024 | config HARDLOCKUP_DETECTOR_PERF |
1025 | bool | |
1026 | select SOFTLOCKUP_DETECTOR | |
1027 | ||
7edaeb68 TG |
1028 | # |
1029 | # Enables a timestamp based low pass filter to compensate for perf based | |
1030 | # hard lockup detection which runs too fast due to turbo modes. | |
1031 | # | |
1032 | config HARDLOCKUP_CHECK_TIMESTAMP | |
1033 | bool | |
1034 | ||
05a4a952 NP |
1035 | # |
1036 | # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard | |
1037 | # lockup detector rather than the perf based detector. | |
1038 | # | |
1039 | config HARDLOCKUP_DETECTOR | |
1040 | bool "Detect Hard Lockups" | |
1041 | depends on DEBUG_KERNEL && !S390 | |
1042 | depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH | |
1043 | select LOCKUP_DETECTOR | |
1044 | select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF | |
1045 | select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH | |
1046 | help | |
1047 | Say Y here to enable the kernel to act as a watchdog to detect | |
1048 | hard lockups. | |
1049 | ||
58687acb | 1050 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
5f329089 | 1051 | for more than 10 seconds, without letting other interrupts have a |
58687acb DZ |
1052 | chance to run. The current stack trace is displayed upon detection |
1053 | and the system will stay locked up. | |
8446f1d3 | 1054 | |
fef2c9bc DZ |
1055 | config BOOTPARAM_HARDLOCKUP_PANIC |
1056 | bool "Panic (Reboot) On Hard Lockups" | |
8f1f66ed | 1057 | depends on HARDLOCKUP_DETECTOR |
fef2c9bc DZ |
1058 | help |
1059 | Say Y here to enable the kernel to panic on "hard lockups", | |
1060 | which are bugs that cause the kernel to loop in kernel | |
5f329089 FLVC |
1061 | mode with interrupts disabled for more than 10 seconds (configurable |
1062 | using the watchdog_thresh sysctl). | |
fef2c9bc DZ |
1063 | |
1064 | Say N if unsure. | |
1065 | ||
1066 | config BOOTPARAM_HARDLOCKUP_PANIC_VALUE | |
1067 | int | |
8f1f66ed | 1068 | depends on HARDLOCKUP_DETECTOR |
fef2c9bc DZ |
1069 | range 0 1 |
1070 | default 0 if !BOOTPARAM_HARDLOCKUP_PANIC | |
1071 | default 1 if BOOTPARAM_HARDLOCKUP_PANIC | |
1072 | ||
e162b39a MSB |
1073 | config DETECT_HUNG_TASK |
1074 | bool "Detect Hung Tasks" | |
1075 | depends on DEBUG_KERNEL | |
05a4a952 | 1076 | default SOFTLOCKUP_DETECTOR |
e162b39a | 1077 | help |
0610c8a8 DH |
1078 | Say Y here to enable the kernel to detect "hung tasks", |
1079 | which are bugs that cause the task to be stuck in | |
96b03ab8 | 1080 | uninterruptible "D" state indefinitely. |
1da177e4 | 1081 | |
0610c8a8 DH |
1082 | When a hung task is detected, the kernel will print the |
1083 | current stack trace (which you should report), but the | |
1084 | task will stay in uninterruptible state. If lockdep is | |
1085 | enabled then all held locks will also be reported. This | |
1086 | feature has negligible overhead. | |
871751e2 | 1087 | |
0610c8a8 DH |
1088 | config DEFAULT_HUNG_TASK_TIMEOUT |
1089 | int "Default timeout for hung task detection (in seconds)" | |
1090 | depends on DETECT_HUNG_TASK | |
1091 | default 120 | |
f0630fff | 1092 | help |
0610c8a8 DH |
1093 | This option controls the default timeout (in seconds) used |
1094 | to determine when a task has become non-responsive and should | |
1095 | be considered hung. | |
f0630fff | 1096 | |
0610c8a8 DH |
1097 | It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
1098 | sysctl or by writing a value to | |
1099 | /proc/sys/kernel/hung_task_timeout_secs. | |
8ff12cfc | 1100 | |
0610c8a8 DH |
1101 | A timeout of 0 disables the check. The default is two minutes. |
1102 | Keeping the default should be fine in most cases. | |
b69ec42b | 1103 | |
0610c8a8 DH |
1104 | config BOOTPARAM_HUNG_TASK_PANIC |
1105 | bool "Panic (Reboot) On Hung Tasks" | |
1106 | depends on DETECT_HUNG_TASK | |
3bba00d7 | 1107 | help |
0610c8a8 DH |
1108 | Say Y here to enable the kernel to panic on "hung tasks", |
1109 | which are bugs that cause the kernel to leave a task stuck | |
1110 | in uninterruptible "D" state. | |
3bba00d7 | 1111 | |
0610c8a8 DH |
1112 | The panic can be used in combination with panic_timeout, |
1113 | to cause the system to reboot automatically after a | |
1114 | hung task has been detected. This feature is useful for | |
1115 | high-availability systems that have uptime guarantees and | |
1116 | where a hung tasks must be resolved ASAP. | |
bf96d1e3 | 1117 | |
0610c8a8 | 1118 | Say N if unsure. |
bf96d1e3 | 1119 | |
0610c8a8 DH |
1120 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
1121 | int | |
1122 | depends on DETECT_HUNG_TASK | |
1123 | range 0 1 | |
1124 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC | |
1125 | default 1 if BOOTPARAM_HUNG_TASK_PANIC | |
3bba00d7 | 1126 | |
82607adc TH |
1127 | config WQ_WATCHDOG |
1128 | bool "Detect Workqueue Stalls" | |
1129 | depends on DEBUG_KERNEL | |
1130 | help | |
1131 | Say Y here to enable stall detection on workqueues. If a | |
1132 | worker pool doesn't make forward progress on a pending work | |
1133 | item for over a given amount of time, 30s by default, a | |
1134 | warning message is printed along with dump of workqueue | |
1135 | state. This can be configured through kernel parameter | |
1136 | "workqueue.watchdog_thresh" and its sysfs counterpart. | |
1137 | ||
30428ef5 KK |
1138 | config TEST_LOCKUP |
1139 | tristate "Test module to generate lockups" | |
63646bc9 | 1140 | depends on m |
30428ef5 KK |
1141 | help |
1142 | This builds the "test_lockup" module that helps to make sure | |
1143 | that watchdogs and lockup detectors are working properly. | |
1144 | ||
1145 | Depending on module parameters it could emulate soft or hard | |
1146 | lockup, "hung task", or locking arbitrary lock for a long time. | |
1147 | Also it could generate series of lockups with cooling-down periods. | |
1148 | ||
1149 | If unsure, say N. | |
1150 | ||
92aef8fb DH |
1151 | endmenu # "Debug lockups and hangs" |
1152 | ||
ebebdd09 | 1153 | menu "Scheduler Debugging" |
5800dc3c | 1154 | |
0610c8a8 DH |
1155 | config SCHED_DEBUG |
1156 | bool "Collect scheduler debugging info" | |
1157 | depends on DEBUG_KERNEL && PROC_FS | |
1158 | default y | |
0822ee4a | 1159 | help |
0610c8a8 DH |
1160 | If you say Y here, the /proc/sched_debug file will be provided |
1161 | that can help debug the scheduler. The runtime overhead of this | |
1162 | option is minimal. | |
0822ee4a | 1163 | |
f6db8347 NR |
1164 | config SCHED_INFO |
1165 | bool | |
1166 | default n | |
1167 | ||
0610c8a8 DH |
1168 | config SCHEDSTATS |
1169 | bool "Collect scheduler statistics" | |
1170 | depends on DEBUG_KERNEL && PROC_FS | |
f6db8347 | 1171 | select SCHED_INFO |
0610c8a8 DH |
1172 | help |
1173 | If you say Y here, additional code will be inserted into the | |
1174 | scheduler and related routines to collect statistics about | |
1175 | scheduler behavior and provide them in /proc/schedstat. These | |
1176 | stats may be useful for both tuning and debugging the scheduler | |
1177 | If you aren't debugging the scheduler or trying to tune a specific | |
1178 | application, you can say N to avoid the very slight overhead | |
1179 | this adds. | |
0822ee4a | 1180 | |
ebebdd09 | 1181 | endmenu |
0d9e2632 | 1182 | |
3c17ad19 JS |
1183 | config DEBUG_TIMEKEEPING |
1184 | bool "Enable extra timekeeping sanity checking" | |
1185 | help | |
1186 | This option will enable additional timekeeping sanity checks | |
1187 | which may be helpful when diagnosing issues where timekeeping | |
1188 | problems are suspected. | |
1189 | ||
1190 | This may include checks in the timekeeping hotpaths, so this | |
1191 | option may have a (very small) performance impact to some | |
1192 | workloads. | |
1193 | ||
1194 | If unsure, say N. | |
1195 | ||
1da177e4 LT |
1196 | config DEBUG_PREEMPT |
1197 | bool "Debug preemptible kernel" | |
9f472869 | 1198 | depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT |
1da177e4 LT |
1199 | default y |
1200 | help | |
1201 | If you say Y here then the kernel will use a debug variant of the | |
1202 | commonly used smp_processor_id() function and will print warnings | |
1203 | if kernel code uses it in a preemption-unsafe way. Also, the kernel | |
1204 | will detect preemption count underflows. | |
1205 | ||
9eade16b DH |
1206 | menu "Lock Debugging (spinlocks, mutexes, etc...)" |
1207 | ||
f07cbebb WL |
1208 | config LOCK_DEBUGGING_SUPPORT |
1209 | bool | |
1210 | depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT | |
1211 | default y | |
1212 | ||
19193bca WL |
1213 | config PROVE_LOCKING |
1214 | bool "Lock debugging: prove locking correctness" | |
1215 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT | |
1216 | select LOCKDEP | |
1217 | select DEBUG_SPINLOCK | |
1218 | select DEBUG_MUTEXES | |
1219 | select DEBUG_RT_MUTEXES if RT_MUTEXES | |
c71fd893 | 1220 | select DEBUG_RWSEMS |
19193bca WL |
1221 | select DEBUG_WW_MUTEX_SLOWPATH |
1222 | select DEBUG_LOCK_ALLOC | |
8fd8ad5c | 1223 | select PREEMPT_COUNT if !ARCH_NO_PREEMPT |
19193bca WL |
1224 | select TRACE_IRQFLAGS |
1225 | default n | |
1226 | help | |
1227 | This feature enables the kernel to prove that all locking | |
1228 | that occurs in the kernel runtime is mathematically | |
1229 | correct: that under no circumstance could an arbitrary (and | |
1230 | not yet triggered) combination of observed locking | |
1231 | sequences (on an arbitrary number of CPUs, running an | |
1232 | arbitrary number of tasks and interrupt contexts) cause a | |
1233 | deadlock. | |
1234 | ||
1235 | In short, this feature enables the kernel to report locking | |
1236 | related deadlocks before they actually occur. | |
1237 | ||
1238 | The proof does not depend on how hard and complex a | |
1239 | deadlock scenario would be to trigger: how many | |
1240 | participant CPUs, tasks and irq-contexts would be needed | |
1241 | for it to trigger. The proof also does not depend on | |
1242 | timing: if a race and a resulting deadlock is possible | |
1243 | theoretically (no matter how unlikely the race scenario | |
1244 | is), it will be proven so and will immediately be | |
1245 | reported by the kernel (once the event is observed that | |
1246 | makes the deadlock theoretically possible). | |
1247 | ||
1248 | If a deadlock is impossible (i.e. the locking rules, as | |
1249 | observed by the kernel, are mathematically correct), the | |
1250 | kernel reports nothing. | |
1251 | ||
1252 | NOTE: this feature can also be enabled for rwlocks, mutexes | |
1253 | and rwsems - in which case all dependencies between these | |
1254 | different locking variants are observed and mapped too, and | |
1255 | the proof of observed correctness is also maintained for an | |
1256 | arbitrary combination of these separate locking variants. | |
1257 | ||
387b1468 | 1258 | For more details, see Documentation/locking/lockdep-design.rst. |
19193bca | 1259 | |
de8f5e4f PZ |
1260 | config PROVE_RAW_LOCK_NESTING |
1261 | bool "Enable raw_spinlock - spinlock nesting checks" | |
1262 | depends on PROVE_LOCKING | |
1263 | default n | |
1264 | help | |
1265 | Enable the raw_spinlock vs. spinlock nesting checks which ensure | |
1266 | that the lock nesting rules for PREEMPT_RT enabled kernels are | |
1267 | not violated. | |
1268 | ||
1269 | NOTE: There are known nesting problems. So if you enable this | |
1270 | option expect lockdep splats until these problems have been fully | |
1271 | addressed which is work in progress. This config switch allows to | |
1272 | identify and analyze these problems. It will be removed and the | |
1273 | check permanentely enabled once the main issues have been fixed. | |
1274 | ||
1275 | If unsure, select N. | |
1276 | ||
19193bca WL |
1277 | config LOCK_STAT |
1278 | bool "Lock usage statistics" | |
1279 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT | |
1280 | select LOCKDEP | |
1281 | select DEBUG_SPINLOCK | |
1282 | select DEBUG_MUTEXES | |
1283 | select DEBUG_RT_MUTEXES if RT_MUTEXES | |
1284 | select DEBUG_LOCK_ALLOC | |
1285 | default n | |
1286 | help | |
1287 | This feature enables tracking lock contention points | |
1288 | ||
387b1468 | 1289 | For more details, see Documentation/locking/lockstat.rst |
19193bca WL |
1290 | |
1291 | This also enables lock events required by "perf lock", | |
1292 | subcommand of perf. | |
1293 | If you want to use "perf lock", you also need to turn on | |
1294 | CONFIG_EVENT_TRACING. | |
1295 | ||
1296 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. | |
1297 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) | |
1298 | ||
e7eebaf6 IM |
1299 | config DEBUG_RT_MUTEXES |
1300 | bool "RT Mutex debugging, deadlock detection" | |
e7eebaf6 IM |
1301 | depends on DEBUG_KERNEL && RT_MUTEXES |
1302 | help | |
1303 | This allows rt mutex semantics violations and rt mutex related | |
1304 | deadlocks (lockups) to be detected and reported automatically. | |
1305 | ||
1da177e4 | 1306 | config DEBUG_SPINLOCK |
4d9f34ad | 1307 | bool "Spinlock and rw-lock debugging: basic checks" |
1da177e4 | 1308 | depends on DEBUG_KERNEL |
e335e3eb | 1309 | select UNINLINE_SPIN_UNLOCK |
1da177e4 LT |
1310 | help |
1311 | Say Y here and build SMP to catch missing spinlock initialization | |
1312 | and certain other kinds of spinlock errors commonly made. This is | |
1313 | best used in conjunction with the NMI watchdog so that spinlock | |
1314 | deadlocks are also debuggable. | |
1315 | ||
4d9f34ad IM |
1316 | config DEBUG_MUTEXES |
1317 | bool "Mutex debugging: basic checks" | |
1318 | depends on DEBUG_KERNEL | |
1319 | help | |
1320 | This feature allows mutex semantics violations to be detected and | |
1321 | reported. | |
1322 | ||
23010027 DV |
1323 | config DEBUG_WW_MUTEX_SLOWPATH |
1324 | bool "Wait/wound mutex debugging: Slowpath testing" | |
f07cbebb | 1325 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
23010027 DV |
1326 | select DEBUG_LOCK_ALLOC |
1327 | select DEBUG_SPINLOCK | |
1328 | select DEBUG_MUTEXES | |
1329 | help | |
1330 | This feature enables slowpath testing for w/w mutex users by | |
1331 | injecting additional -EDEADLK wound/backoff cases. Together with | |
1332 | the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this | |
1333 | will test all possible w/w mutex interface abuse with the | |
1334 | exception of simply not acquiring all the required locks. | |
4d692373 RC |
1335 | Note that this feature can introduce significant overhead, so |
1336 | it really should not be enabled in a production or distro kernel, | |
1337 | even a debug kernel. If you are a driver writer, enable it. If | |
1338 | you are a distro, do not. | |
23010027 | 1339 | |
5149cbac WL |
1340 | config DEBUG_RWSEMS |
1341 | bool "RW Semaphore debugging: basic checks" | |
c71fd893 | 1342 | depends on DEBUG_KERNEL |
5149cbac | 1343 | help |
c71fd893 WL |
1344 | This debugging feature allows mismatched rw semaphore locks |
1345 | and unlocks to be detected and reported. | |
5149cbac | 1346 | |
4d9f34ad IM |
1347 | config DEBUG_LOCK_ALLOC |
1348 | bool "Lock debugging: detect incorrect freeing of live locks" | |
f07cbebb | 1349 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
4d9f34ad IM |
1350 | select DEBUG_SPINLOCK |
1351 | select DEBUG_MUTEXES | |
f5694788 | 1352 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
4d9f34ad IM |
1353 | select LOCKDEP |
1354 | help | |
1355 | This feature will check whether any held lock (spinlock, rwlock, | |
1356 | mutex or rwsem) is incorrectly freed by the kernel, via any of the | |
1357 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), | |
1358 | vfree(), etc.), whether a live lock is incorrectly reinitialized via | |
1359 | spin_lock_init()/mutex_init()/etc., or whether there is any lock | |
1360 | held during task exit. | |
1361 | ||
4d9f34ad IM |
1362 | config LOCKDEP |
1363 | bool | |
f07cbebb | 1364 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
4d9f34ad | 1365 | select STACKTRACE |
f9b58e8c | 1366 | select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86 |
4d9f34ad IM |
1367 | select KALLSYMS |
1368 | select KALLSYMS_ALL | |
1369 | ||
395102db DJ |
1370 | config LOCKDEP_SMALL |
1371 | bool | |
1372 | ||
4d9f34ad IM |
1373 | config DEBUG_LOCKDEP |
1374 | bool "Lock dependency engine debugging" | |
517e7aa5 | 1375 | depends on DEBUG_KERNEL && LOCKDEP |
997acaf6 | 1376 | select DEBUG_IRQFLAGS |
4d9f34ad IM |
1377 | help |
1378 | If you say Y here, the lock dependency engine will do | |
1379 | additional runtime checks to debug itself, at the price | |
1380 | of more runtime overhead. | |
1381 | ||
d902db1e FW |
1382 | config DEBUG_ATOMIC_SLEEP |
1383 | bool "Sleep inside atomic section checking" | |
e8f7c70f | 1384 | select PREEMPT_COUNT |
1da177e4 | 1385 | depends on DEBUG_KERNEL |
87a4c375 | 1386 | depends on !ARCH_NO_PREEMPT |
1da177e4 LT |
1387 | help |
1388 | If you say Y here, various routines which may sleep will become very | |
d902db1e FW |
1389 | noisy if they are called inside atomic sections: when a spinlock is |
1390 | held, inside an rcu read side critical section, inside preempt disabled | |
1391 | sections, inside an interrupt, etc... | |
1da177e4 | 1392 | |
cae2ed9a IM |
1393 | config DEBUG_LOCKING_API_SELFTESTS |
1394 | bool "Locking API boot-time self-tests" | |
1395 | depends on DEBUG_KERNEL | |
1396 | help | |
1397 | Say Y here if you want the kernel to run a short self-test during | |
1398 | bootup. The self-test checks whether common types of locking bugs | |
1399 | are detected by debugging mechanisms or not. (if you disable | |
1400 | lock debugging then those bugs wont be detected of course.) | |
1401 | The following locking APIs are covered: spinlocks, rwlocks, | |
1402 | mutexes and rwsems. | |
1403 | ||
0af3fe1e PM |
1404 | config LOCK_TORTURE_TEST |
1405 | tristate "torture tests for locking" | |
1406 | depends on DEBUG_KERNEL | |
1407 | select TORTURE_TEST | |
0af3fe1e PM |
1408 | help |
1409 | This option provides a kernel module that runs torture tests | |
1410 | on kernel locking primitives. The kernel module may be built | |
1411 | after the fact on the running kernel to be tested, if desired. | |
1412 | ||
1413 | Say Y here if you want kernel locking-primitive torture tests | |
1414 | to be built into the kernel. | |
1415 | Say M if you want these torture tests to build as a module. | |
1416 | Say N if you are unsure. | |
1417 | ||
f2a5fec1 CW |
1418 | config WW_MUTEX_SELFTEST |
1419 | tristate "Wait/wound mutex selftests" | |
1420 | help | |
1421 | This option provides a kernel module that runs tests on the | |
1422 | on the struct ww_mutex locking API. | |
1423 | ||
1424 | It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction | |
1425 | with this test harness. | |
1426 | ||
1427 | Say M if you want these self tests to build as a module. | |
1428 | Say N if you are unsure. | |
1429 | ||
e9d338a0 PM |
1430 | config SCF_TORTURE_TEST |
1431 | tristate "torture tests for smp_call_function*()" | |
1432 | depends on DEBUG_KERNEL | |
1433 | select TORTURE_TEST | |
1434 | help | |
1435 | This option provides a kernel module that runs torture tests | |
1436 | on the smp_call_function() family of primitives. The kernel | |
1437 | module may be built after the fact on the running kernel to | |
1438 | be tested, if desired. | |
1439 | ||
35feb604 PM |
1440 | config CSD_LOCK_WAIT_DEBUG |
1441 | bool "Debugging for csd_lock_wait(), called from smp_call_function*()" | |
1442 | depends on DEBUG_KERNEL | |
1443 | depends on 64BIT | |
1444 | default n | |
1445 | help | |
1446 | This option enables debug prints when CPUs are slow to respond | |
1447 | to the smp_call_function*() IPI wrappers. These debug prints | |
1448 | include the IPI handler function currently executing (if any) | |
1449 | and relevant stack traces. | |
1450 | ||
9eade16b | 1451 | endmenu # lock debugging |
8637c099 | 1452 | |
9eade16b | 1453 | config TRACE_IRQFLAGS |
ed004953 | 1454 | depends on TRACE_IRQFLAGS_SUPPORT |
9eade16b | 1455 | bool |
5ca43f6c | 1456 | help |
9eade16b DH |
1457 | Enables hooks to interrupt enabling and disabling for |
1458 | either tracing or lock debugging. | |
5ca43f6c | 1459 | |
ed004953 | 1460 | config TRACE_IRQFLAGS_NMI |
1461 | def_bool y | |
1462 | depends on TRACE_IRQFLAGS | |
1463 | depends on TRACE_IRQFLAGS_NMI_SUPPORT | |
1464 | ||
997acaf6 MR |
1465 | config DEBUG_IRQFLAGS |
1466 | bool "Debug IRQ flag manipulation" | |
1467 | help | |
1468 | Enables checks for potentially unsafe enabling or disabling of | |
1469 | interrupts, such as calling raw_local_irq_restore() when interrupts | |
1470 | are enabled. | |
1471 | ||
8637c099 | 1472 | config STACKTRACE |
0c38e1fe | 1473 | bool "Stack backtrace support" |
8637c099 | 1474 | depends on STACKTRACE_SUPPORT |
0c38e1fe DJ |
1475 | help |
1476 | This option causes the kernel to create a /proc/pid/stack for | |
1477 | every process, showing its current stack trace. | |
1478 | It is also used by various kernel debugging features that require | |
1479 | stack trace generation. | |
5ca43f6c | 1480 | |
eecabf56 TT |
1481 | config WARN_ALL_UNSEEDED_RANDOM |
1482 | bool "Warn for all uses of unseeded randomness" | |
1483 | default n | |
d06bfd19 JD |
1484 | help |
1485 | Some parts of the kernel contain bugs relating to their use of | |
1486 | cryptographically secure random numbers before it's actually possible | |
1487 | to generate those numbers securely. This setting ensures that these | |
1488 | flaws don't go unnoticed, by enabling a message, should this ever | |
1489 | occur. This will allow people with obscure setups to know when things | |
1490 | are going wrong, so that they might contact developers about fixing | |
1491 | it. | |
1492 | ||
eecabf56 TT |
1493 | Unfortunately, on some models of some architectures getting |
1494 | a fully seeded CRNG is extremely difficult, and so this can | |
1495 | result in dmesg getting spammed for a surprisingly long | |
1496 | time. This is really bad from a security perspective, and | |
1497 | so architecture maintainers really need to do what they can | |
1498 | to get the CRNG seeded sooner after the system is booted. | |
4c5d114e | 1499 | However, since users cannot do anything actionable to |
eecabf56 TT |
1500 | address this, by default the kernel will issue only a single |
1501 | warning for the first use of unseeded randomness. | |
1502 | ||
1503 | Say Y here if you want to receive warnings for all uses of | |
1504 | unseeded randomness. This will be of use primarily for | |
4c5d114e | 1505 | those developers interested in improving the security of |
eecabf56 TT |
1506 | Linux kernels running on their architecture (or |
1507 | subarchitecture). | |
d06bfd19 | 1508 | |
1da177e4 LT |
1509 | config DEBUG_KOBJECT |
1510 | bool "kobject debugging" | |
1511 | depends on DEBUG_KERNEL | |
1512 | help | |
1513 | If you say Y here, some extra kobject debugging messages will be sent | |
aca52c39 | 1514 | to the syslog. |
1da177e4 | 1515 | |
c817a67e RK |
1516 | config DEBUG_KOBJECT_RELEASE |
1517 | bool "kobject release debugging" | |
2a999aa0 | 1518 | depends on DEBUG_OBJECTS_TIMERS |
c817a67e RK |
1519 | help |
1520 | kobjects are reference counted objects. This means that their | |
1521 | last reference count put is not predictable, and the kobject can | |
1522 | live on past the point at which a driver decides to drop it's | |
1523 | initial reference to the kobject gained on allocation. An | |
1524 | example of this would be a struct device which has just been | |
1525 | unregistered. | |
1526 | ||
1527 | However, some buggy drivers assume that after such an operation, | |
1528 | the memory backing the kobject can be immediately freed. This | |
1529 | goes completely against the principles of a refcounted object. | |
1530 | ||
1531 | If you say Y here, the kernel will delay the release of kobjects | |
1532 | on the last reference count to improve the visibility of this | |
1533 | kind of kobject release bug. | |
1534 | ||
9b2a60c4 CM |
1535 | config HAVE_DEBUG_BUGVERBOSE |
1536 | bool | |
1537 | ||
3be5cbcd | 1538 | menu "Debug kernel data structures" |
1da177e4 | 1539 | |
199a9afc DJ |
1540 | config DEBUG_LIST |
1541 | bool "Debug linked list manipulation" | |
4520bcb2 | 1542 | depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION |
199a9afc DJ |
1543 | help |
1544 | Enable this to turn on extended checks in the linked-list | |
1545 | walking routines. | |
1546 | ||
1547 | If unsure, say N. | |
1548 | ||
8e18faea | 1549 | config DEBUG_PLIST |
b8cfff68 DS |
1550 | bool "Debug priority linked list manipulation" |
1551 | depends on DEBUG_KERNEL | |
1552 | help | |
1553 | Enable this to turn on extended checks in the priority-ordered | |
1554 | linked-list (plist) walking routines. This checks the entire | |
1555 | list multiple times during each manipulation. | |
1556 | ||
1557 | If unsure, say N. | |
1558 | ||
d6ec0842 JA |
1559 | config DEBUG_SG |
1560 | bool "Debug SG table operations" | |
1561 | depends on DEBUG_KERNEL | |
1562 | help | |
1563 | Enable this to turn on checks on scatter-gather tables. This can | |
1564 | help find problems with drivers that do not properly initialize | |
1565 | their sg tables. | |
1566 | ||
1567 | If unsure, say N. | |
1568 | ||
1b2439db AV |
1569 | config DEBUG_NOTIFIERS |
1570 | bool "Debug notifier call chains" | |
1571 | depends on DEBUG_KERNEL | |
1572 | help | |
1573 | Enable this to turn on sanity checking for notifier call chains. | |
1574 | This is most useful for kernel developers to make sure that | |
1575 | modules properly unregister themselves from notifier chains. | |
1576 | This is a relatively cheap check but if you care about maximum | |
1577 | performance, say N. | |
1578 | ||
3be5cbcd CD |
1579 | config BUG_ON_DATA_CORRUPTION |
1580 | bool "Trigger a BUG when data corruption is detected" | |
1581 | select DEBUG_LIST | |
1582 | help | |
1583 | Select this option if the kernel should BUG when it encounters | |
1584 | data corruption in kernel memory structures when they get checked | |
1585 | for validity. | |
1586 | ||
1587 | If unsure, say N. | |
1588 | ||
1589 | endmenu | |
1590 | ||
e0e81739 DH |
1591 | config DEBUG_CREDENTIALS |
1592 | bool "Debug credential management" | |
1593 | depends on DEBUG_KERNEL | |
1594 | help | |
1595 | Enable this to turn on some debug checking for credential | |
1596 | management. The additional code keeps track of the number of | |
1597 | pointers from task_structs to any given cred struct, and checks to | |
1598 | see that this number never exceeds the usage count of the cred | |
1599 | struct. | |
1600 | ||
1601 | Furthermore, if SELinux is enabled, this also checks that the | |
1602 | security pointer in the cred struct is never seen to be invalid. | |
1603 | ||
1604 | If unsure, say N. | |
1605 | ||
43a0a2a7 | 1606 | source "kernel/rcu/Kconfig.debug" |
2f03e3ca | 1607 | |
f303fccb TH |
1608 | config DEBUG_WQ_FORCE_RR_CPU |
1609 | bool "Force round-robin CPU selection for unbound work items" | |
1610 | depends on DEBUG_KERNEL | |
1611 | default n | |
1612 | help | |
1613 | Workqueue used to implicitly guarantee that work items queued | |
1614 | without explicit CPU specified are put on the local CPU. This | |
1615 | guarantee is no longer true and while local CPU is still | |
1616 | preferred work items may be put on foreign CPUs. Kernel | |
1617 | parameter "workqueue.debug_force_rr_cpu" is added to force | |
1618 | round-robin CPU selection to flush out usages which depend on the | |
1619 | now broken guarantee. This config option enables the debug | |
1620 | feature by default. When enabled, memory and cache locality will | |
1621 | be impacted. | |
1622 | ||
870d6656 | 1623 | config DEBUG_BLOCK_EXT_DEVT |
68d4b3df | 1624 | bool "Force extended block device numbers and spread them" |
870d6656 TH |
1625 | depends on DEBUG_KERNEL |
1626 | depends on BLOCK | |
759f8ca3 | 1627 | default n |
870d6656 | 1628 | help |
0e11e342 TH |
1629 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
1630 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT | |
1631 | YOU ARE DOING. Distros, please enable this and fix whatever | |
1632 | is broken. | |
1633 | ||
870d6656 TH |
1634 | Conventionally, block device numbers are allocated from |
1635 | predetermined contiguous area. However, extended block area | |
1636 | may introduce non-contiguous block device numbers. This | |
1637 | option forces most block device numbers to be allocated from | |
1638 | the extended space and spreads them to discover kernel or | |
1639 | userland code paths which assume predetermined contiguous | |
1640 | device number allocation. | |
1641 | ||
55dc7db7 TH |
1642 | Note that turning on this debug option shuffles all the |
1643 | device numbers for all IDE and SCSI devices including libata | |
1644 | ones, so root partition specified using device number | |
1645 | directly (via rdev or root=MAJ:MIN) won't work anymore. | |
1646 | Textual device names (root=/dev/sdXn) will continue to work. | |
1647 | ||
870d6656 TH |
1648 | Say N if you are unsure. |
1649 | ||
757c989b TG |
1650 | config CPU_HOTPLUG_STATE_CONTROL |
1651 | bool "Enable CPU hotplug state control" | |
1652 | depends on DEBUG_KERNEL | |
1653 | depends on HOTPLUG_CPU | |
1654 | default n | |
1655 | help | |
1656 | Allows to write steps between "offline" and "online" to the CPUs | |
1657 | sysfs target file so states can be stepped granular. This is a debug | |
1658 | option for now as the hotplug machinery cannot be stopped and | |
1659 | restarted at arbitrary points yet. | |
1660 | ||
1661 | Say N if your are unsure. | |
1662 | ||
09a74952 CD |
1663 | config LATENCYTOP |
1664 | bool "Latency measuring infrastructure" | |
1665 | depends on DEBUG_KERNEL | |
1666 | depends on STACKTRACE_SUPPORT | |
1667 | depends on PROC_FS | |
1668 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 | |
1669 | select KALLSYMS | |
1670 | select KALLSYMS_ALL | |
1671 | select STACKTRACE | |
1672 | select SCHEDSTATS | |
1673 | select SCHED_DEBUG | |
1674 | help | |
1675 | Enable this option if you want to use the LatencyTOP tool | |
1676 | to find out which userspace is blocking on what kernel operations. | |
1677 | ||
1678 | source "kernel/trace/Kconfig" | |
1679 | ||
1680 | config PROVIDE_OHCI1394_DMA_INIT | |
1681 | bool "Remote debugging over FireWire early on boot" | |
1682 | depends on PCI && X86 | |
1683 | help | |
1684 | If you want to debug problems which hang or crash the kernel early | |
1685 | on boot and the crashing machine has a FireWire port, you can use | |
1686 | this feature to remotely access the memory of the crashed machine | |
1687 | over FireWire. This employs remote DMA as part of the OHCI1394 | |
1688 | specification which is now the standard for FireWire controllers. | |
1689 | ||
1690 | With remote DMA, you can monitor the printk buffer remotely using | |
1691 | firescope and access all memory below 4GB using fireproxy from gdb. | |
1692 | Even controlling a kernel debugger is possible using remote DMA. | |
1693 | ||
1694 | Usage: | |
1695 | ||
1696 | If ohci1394_dma=early is used as boot parameter, it will initialize | |
1697 | all OHCI1394 controllers which are found in the PCI config space. | |
1698 | ||
1699 | As all changes to the FireWire bus such as enabling and disabling | |
1700 | devices cause a bus reset and thereby disable remote DMA for all | |
1701 | devices, be sure to have the cable plugged and FireWire enabled on | |
1702 | the debugging host before booting the debug target for debugging. | |
1703 | ||
1704 | This code (~1k) is freed after boot. By then, the firewire stack | |
1705 | in charge of the OHCI-1394 controllers should be used instead. | |
1706 | ||
a74e2a22 | 1707 | See Documentation/core-api/debugging-via-ohci1394.rst for more information. |
09a74952 | 1708 | |
045f6d79 CD |
1709 | source "samples/Kconfig" |
1710 | ||
1711 | config ARCH_HAS_DEVMEM_IS_ALLOWED | |
1712 | bool | |
1713 | ||
1714 | config STRICT_DEVMEM | |
1715 | bool "Filter access to /dev/mem" | |
1716 | depends on MMU && DEVMEM | |
527701ed | 1717 | depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED |
045f6d79 CD |
1718 | default y if PPC || X86 || ARM64 |
1719 | help | |
1720 | If this option is disabled, you allow userspace (root) access to all | |
1721 | of memory, including kernel and userspace memory. Accidental | |
1722 | access to this is obviously disastrous, but specific access can | |
1723 | be used by people debugging the kernel. Note that with PAT support | |
1724 | enabled, even in this case there are restrictions on /dev/mem | |
1725 | use due to the cache aliasing requirements. | |
1726 | ||
1727 | If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem | |
1728 | file only allows userspace access to PCI space and the BIOS code and | |
1729 | data regions. This is sufficient for dosemu and X and all common | |
1730 | users of /dev/mem. | |
1731 | ||
1732 | If in doubt, say Y. | |
1733 | ||
1734 | config IO_STRICT_DEVMEM | |
1735 | bool "Filter I/O access to /dev/mem" | |
1736 | depends on STRICT_DEVMEM | |
1737 | help | |
1738 | If this option is disabled, you allow userspace (root) access to all | |
1739 | io-memory regardless of whether a driver is actively using that | |
1740 | range. Accidental access to this is obviously disastrous, but | |
1741 | specific access can be used by people debugging kernel drivers. | |
1742 | ||
1743 | If this option is switched on, the /dev/mem file only allows | |
1744 | userspace access to *idle* io-memory ranges (see /proc/iomem) This | |
1745 | may break traditional users of /dev/mem (dosemu, legacy X, etc...) | |
1746 | if the driver using a given range cannot be disabled. | |
1747 | ||
1748 | If in doubt, say Y. | |
1749 | ||
1750 | menu "$(SRCARCH) Debugging" | |
1751 | ||
1752 | source "arch/$(SRCARCH)/Kconfig.debug" | |
1753 | ||
1754 | endmenu | |
1755 | ||
1756 | menu "Kernel Testing and Coverage" | |
1757 | ||
09a74952 CD |
1758 | source "lib/kunit/Kconfig" |
1759 | ||
8d438288 AM |
1760 | config NOTIFIER_ERROR_INJECTION |
1761 | tristate "Notifier error injection" | |
1762 | depends on DEBUG_KERNEL | |
1763 | select DEBUG_FS | |
1764 | help | |
e41e85cc | 1765 | This option provides the ability to inject artificial errors to |
8d438288 AM |
1766 | specified notifier chain callbacks. It is useful to test the error |
1767 | handling of notifier call chain failures. | |
1768 | ||
1769 | Say N if unsure. | |
1770 | ||
048b9c35 AM |
1771 | config PM_NOTIFIER_ERROR_INJECT |
1772 | tristate "PM notifier error injection module" | |
1773 | depends on PM && NOTIFIER_ERROR_INJECTION | |
1774 | default m if PM_DEBUG | |
1775 | help | |
e41e85cc | 1776 | This option provides the ability to inject artificial errors to |
048b9c35 AM |
1777 | PM notifier chain callbacks. It is controlled through debugfs |
1778 | interface /sys/kernel/debug/notifier-error-inject/pm | |
1779 | ||
1780 | If the notifier call chain should be failed with some events | |
1781 | notified, write the error code to "actions/<notifier event>/error". | |
1782 | ||
1783 | Example: Inject PM suspend error (-12 = -ENOMEM) | |
1784 | ||
1785 | # cd /sys/kernel/debug/notifier-error-inject/pm/ | |
1786 | # echo -12 > actions/PM_SUSPEND_PREPARE/error | |
1787 | # echo mem > /sys/power/state | |
1788 | bash: echo: write error: Cannot allocate memory | |
1789 | ||
1790 | To compile this code as a module, choose M here: the module will | |
1791 | be called pm-notifier-error-inject. | |
1792 | ||
1793 | If unsure, say N. | |
1794 | ||
d526e85f BH |
1795 | config OF_RECONFIG_NOTIFIER_ERROR_INJECT |
1796 | tristate "OF reconfig notifier error injection module" | |
1797 | depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION | |
08dfb4dd | 1798 | help |
e41e85cc | 1799 | This option provides the ability to inject artificial errors to |
d526e85f | 1800 | OF reconfig notifier chain callbacks. It is controlled |
08dfb4dd | 1801 | through debugfs interface under |
d526e85f | 1802 | /sys/kernel/debug/notifier-error-inject/OF-reconfig/ |
08dfb4dd AM |
1803 | |
1804 | If the notifier call chain should be failed with some events | |
1805 | notified, write the error code to "actions/<notifier event>/error". | |
1806 | ||
1807 | To compile this code as a module, choose M here: the module will | |
e12a95f4 | 1808 | be called of-reconfig-notifier-error-inject. |
08dfb4dd AM |
1809 | |
1810 | If unsure, say N. | |
1811 | ||
02fff96a NA |
1812 | config NETDEV_NOTIFIER_ERROR_INJECT |
1813 | tristate "Netdev notifier error injection module" | |
1814 | depends on NET && NOTIFIER_ERROR_INJECTION | |
1815 | help | |
1816 | This option provides the ability to inject artificial errors to | |
1817 | netdevice notifier chain callbacks. It is controlled through debugfs | |
1818 | interface /sys/kernel/debug/notifier-error-inject/netdev | |
1819 | ||
1820 | If the notifier call chain should be failed with some events | |
1821 | notified, write the error code to "actions/<notifier event>/error". | |
1822 | ||
1823 | Example: Inject netdevice mtu change error (-22 = -EINVAL) | |
1824 | ||
1825 | # cd /sys/kernel/debug/notifier-error-inject/netdev | |
1826 | # echo -22 > actions/NETDEV_CHANGEMTU/error | |
1827 | # ip link set eth0 mtu 1024 | |
1828 | RTNETLINK answers: Invalid argument | |
1829 | ||
1830 | To compile this code as a module, choose M here: the module will | |
1831 | be called netdev-notifier-error-inject. | |
1832 | ||
1833 | If unsure, say N. | |
1834 | ||
f1b4bd06 MP |
1835 | config FUNCTION_ERROR_INJECTION |
1836 | def_bool y | |
1837 | depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES | |
1838 | ||
6ff1cb35 | 1839 | config FAULT_INJECTION |
1ab8509a AM |
1840 | bool "Fault-injection framework" |
1841 | depends on DEBUG_KERNEL | |
329409ae AM |
1842 | help |
1843 | Provide fault-injection framework. | |
1844 | For more details, see Documentation/fault-injection/. | |
6ff1cb35 | 1845 | |
8a8b6502 | 1846 | config FAILSLAB |
1ab8509a AM |
1847 | bool "Fault-injection capability for kmalloc" |
1848 | depends on FAULT_INJECTION | |
773ff60e | 1849 | depends on SLAB || SLUB |
8a8b6502 | 1850 | help |
1ab8509a | 1851 | Provide fault-injection capability for kmalloc. |
8a8b6502 | 1852 | |
933e312e | 1853 | config FAIL_PAGE_ALLOC |
29b46fa3 | 1854 | bool "Fault-injection capability for alloc_pages()" |
1ab8509a | 1855 | depends on FAULT_INJECTION |
933e312e | 1856 | help |
1ab8509a | 1857 | Provide fault-injection capability for alloc_pages(). |
933e312e | 1858 | |
2c739ced AL |
1859 | config FAULT_INJECTION_USERCOPY |
1860 | bool "Fault injection capability for usercopy functions" | |
1861 | depends on FAULT_INJECTION | |
1862 | help | |
1863 | Provides fault-injection capability to inject failures | |
1864 | in usercopy functions (copy_from_user(), get_user(), ...). | |
1865 | ||
c17bb495 | 1866 | config FAIL_MAKE_REQUEST |
86327d19 | 1867 | bool "Fault-injection capability for disk IO" |
581d4e28 | 1868 | depends on FAULT_INJECTION && BLOCK |
c17bb495 | 1869 | help |
1ab8509a | 1870 | Provide fault-injection capability for disk IO. |
c17bb495 | 1871 | |
581d4e28 | 1872 | config FAIL_IO_TIMEOUT |
f4d01439 | 1873 | bool "Fault-injection capability for faking disk interrupts" |
581d4e28 JA |
1874 | depends on FAULT_INJECTION && BLOCK |
1875 | help | |
1876 | Provide fault-injection capability on end IO handling. This | |
1877 | will make the block layer "forget" an interrupt as configured, | |
1878 | thus exercising the error handling. | |
1879 | ||
1880 | Only works with drivers that use the generic timeout handling, | |
1881 | for others it wont do anything. | |
1882 | ||
ab51fbab DB |
1883 | config FAIL_FUTEX |
1884 | bool "Fault-injection capability for futexes" | |
1885 | select DEBUG_FS | |
1886 | depends on FAULT_INJECTION && FUTEX | |
1887 | help | |
1888 | Provide fault-injection capability for futexes. | |
1889 | ||
f1b4bd06 MP |
1890 | config FAULT_INJECTION_DEBUG_FS |
1891 | bool "Debugfs entries for fault-injection capabilities" | |
1892 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS | |
1893 | help | |
1894 | Enable configuration of fault-injection capabilities via debugfs. | |
1895 | ||
4b1a29a7 MH |
1896 | config FAIL_FUNCTION |
1897 | bool "Fault-injection capability for functions" | |
1898 | depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION | |
1899 | help | |
1900 | Provide function-based fault-injection capability. | |
1901 | This will allow you to override a specific function with a return | |
1902 | with given return value. As a result, function caller will see | |
1903 | an error value and have to handle it. This is useful to test the | |
1904 | error handling in various subsystems. | |
1905 | ||
f1b4bd06 MP |
1906 | config FAIL_MMC_REQUEST |
1907 | bool "Fault-injection capability for MMC IO" | |
1908 | depends on FAULT_INJECTION_DEBUG_FS && MMC | |
6ff1cb35 | 1909 | help |
f1b4bd06 MP |
1910 | Provide fault-injection capability for MMC IO. |
1911 | This will make the mmc core return data errors. This is | |
1912 | useful to test the error handling in the mmc block device | |
1913 | and to test how the mmc host driver handles retries from | |
1914 | the block device. | |
1df49008 AM |
1915 | |
1916 | config FAULT_INJECTION_STACKTRACE_FILTER | |
1917 | bool "stacktrace filter for fault-injection capabilities" | |
1918 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT | |
6d690dca | 1919 | depends on !X86_64 |
1df49008 | 1920 | select STACKTRACE |
f9b58e8c | 1921 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 |
1df49008 AM |
1922 | help |
1923 | Provide stacktrace filter for fault-injection capabilities | |
267c4025 | 1924 | |
09a74952 CD |
1925 | config ARCH_HAS_KCOV |
1926 | bool | |
cc3fa840 | 1927 | help |
09a74952 CD |
1928 | An architecture should select this when it can successfully |
1929 | build and run with CONFIG_KCOV. This typically requires | |
1930 | disabling instrumentation for some early boot code. | |
cc3fa840 | 1931 | |
09a74952 CD |
1932 | config CC_HAS_SANCOV_TRACE_PC |
1933 | def_bool $(cc-option,-fsanitize-coverage=trace-pc) | |
cc3fa840 | 1934 | |
cc3fa840 | 1935 | |
09a74952 CD |
1936 | config KCOV |
1937 | bool "Code coverage for fuzzing" | |
1938 | depends on ARCH_HAS_KCOV | |
1939 | depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS | |
1940 | select DEBUG_FS | |
1941 | select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC | |
1942 | help | |
1943 | KCOV exposes kernel code coverage information in a form suitable | |
1944 | for coverage-guided fuzzing (randomized testing). | |
cc3fa840 | 1945 | |
09a74952 CD |
1946 | If RANDOMIZE_BASE is enabled, PC values will not be stable across |
1947 | different machines and across reboots. If you need stable PC values, | |
1948 | disable RANDOMIZE_BASE. | |
cc3fa840 | 1949 | |
09a74952 | 1950 | For more details, see Documentation/dev-tools/kcov.rst. |
cc3fa840 | 1951 | |
09a74952 CD |
1952 | config KCOV_ENABLE_COMPARISONS |
1953 | bool "Enable comparison operands collection by KCOV" | |
1954 | depends on KCOV | |
1955 | depends on $(cc-option,-fsanitize-coverage=trace-cmp) | |
1956 | help | |
1957 | KCOV also exposes operands of every comparison in the instrumented | |
1958 | code along with operand sizes and PCs of the comparison instructions. | |
1959 | These operands can be used by fuzzing engines to improve the quality | |
1960 | of fuzzing coverage. | |
cc3fa840 | 1961 | |
09a74952 CD |
1962 | config KCOV_INSTRUMENT_ALL |
1963 | bool "Instrument all code by default" | |
1964 | depends on KCOV | |
1965 | default y | |
1966 | help | |
1967 | If you are doing generic system call fuzzing (like e.g. syzkaller), | |
1968 | then you will want to instrument the whole kernel and you should | |
1969 | say y here. If you are doing more targeted fuzzing (like e.g. | |
1970 | filesystem fuzzing with AFL) then you will want to enable coverage | |
1971 | for more specific subsets of files, and should say n here. | |
84bc809e | 1972 | |
5ff3b30a AK |
1973 | config KCOV_IRQ_AREA_SIZE |
1974 | hex "Size of interrupt coverage collection area in words" | |
1975 | depends on KCOV | |
1976 | default 0x40000 | |
1977 | help | |
1978 | KCOV uses preallocated per-cpu areas to collect coverage from | |
1979 | soft interrupts. This specifies the size of those areas in the | |
1980 | number of unsigned long words. | |
1981 | ||
d3deafaa VL |
1982 | menuconfig RUNTIME_TESTING_MENU |
1983 | bool "Runtime Testing" | |
908009e8 | 1984 | def_bool y |
d3deafaa VL |
1985 | |
1986 | if RUNTIME_TESTING_MENU | |
881c5149 DH |
1987 | |
1988 | config LKDTM | |
1989 | tristate "Linux Kernel Dump Test Tool Module" | |
1990 | depends on DEBUG_FS | |
881c5149 DH |
1991 | help |
1992 | This module enables testing of the different dumping mechanisms by | |
1993 | inducing system failures at predefined crash points. | |
1994 | If you don't need it: say N | |
1995 | Choose M here to compile this code as a module. The module will be | |
1996 | called lkdtm. | |
1997 | ||
1998 | Documentation on how to use the module can be found in | |
10ffebbe | 1999 | Documentation/fault-injection/provoke-crashes.rst |
881c5149 DH |
2000 | |
2001 | config TEST_LIST_SORT | |
e327fd7c GU |
2002 | tristate "Linked list sorting test" |
2003 | depends on DEBUG_KERNEL || m | |
881c5149 DH |
2004 | help |
2005 | Enable this to turn on 'list_sort()' function test. This test is | |
e327fd7c GU |
2006 | executed only once during system boot (so affects only boot time), |
2007 | or at module load time. | |
881c5149 DH |
2008 | |
2009 | If unsure, say N. | |
2010 | ||
6e24628d IR |
2011 | config TEST_MIN_HEAP |
2012 | tristate "Min heap test" | |
2013 | depends on DEBUG_KERNEL || m | |
2014 | help | |
2015 | Enable this to turn on min heap function tests. This test is | |
2016 | executed only once during system boot (so affects only boot time), | |
2017 | or at module load time. | |
2018 | ||
2019 | If unsure, say N. | |
2020 | ||
c5adae95 | 2021 | config TEST_SORT |
5c4e6798 GU |
2022 | tristate "Array-based sort test" |
2023 | depends on DEBUG_KERNEL || m | |
c5adae95 | 2024 | help |
5c4e6798 GU |
2025 | This option enables the self-test function of 'sort()' at boot, |
2026 | or at module load time. | |
c5adae95 KF |
2027 | |
2028 | If unsure, say N. | |
2029 | ||
881c5149 DH |
2030 | config KPROBES_SANITY_TEST |
2031 | bool "Kprobes sanity tests" | |
2032 | depends on DEBUG_KERNEL | |
2033 | depends on KPROBES | |
881c5149 DH |
2034 | help |
2035 | This option provides for testing basic kprobes functionality on | |
5a6cf77f | 2036 | boot. Samples of kprobe and kretprobe are inserted and |
881c5149 DH |
2037 | verified for functionality. |
2038 | ||
2039 | Say N if you are unsure. | |
2040 | ||
2041 | config BACKTRACE_SELF_TEST | |
2042 | tristate "Self test for the backtrace code" | |
2043 | depends on DEBUG_KERNEL | |
881c5149 DH |
2044 | help |
2045 | This option provides a kernel module that can be used to test | |
2046 | the kernel stack backtrace code. This option is not useful | |
2047 | for distributions or general kernels, but only for kernel | |
2048 | developers working on architecture code. | |
2049 | ||
2050 | Note that if you want to also test saved backtraces, you will | |
2051 | have to enable STACKTRACE as well. | |
2052 | ||
2053 | Say N if you are unsure. | |
2054 | ||
910a742d ML |
2055 | config RBTREE_TEST |
2056 | tristate "Red-Black tree test" | |
7c993e11 | 2057 | depends on DEBUG_KERNEL |
910a742d ML |
2058 | help |
2059 | A benchmark measuring the performance of the rbtree library. | |
2060 | Also includes rbtree invariant checks. | |
2061 | ||
4b4f3acc FB |
2062 | config REED_SOLOMON_TEST |
2063 | tristate "Reed-Solomon library test" | |
2064 | depends on DEBUG_KERNEL || m | |
2065 | select REED_SOLOMON | |
2066 | select REED_SOLOMON_ENC16 | |
2067 | select REED_SOLOMON_DEC16 | |
2068 | help | |
2069 | This option enables the self-test function of rslib at boot, | |
2070 | or at module load time. | |
2071 | ||
2072 | If unsure, say N. | |
2073 | ||
fff3fd8a ML |
2074 | config INTERVAL_TREE_TEST |
2075 | tristate "Interval tree test" | |
0f789b67 | 2076 | depends on DEBUG_KERNEL |
a88cc108 | 2077 | select INTERVAL_TREE |
fff3fd8a ML |
2078 | help |
2079 | A benchmark measuring the performance of the interval tree library | |
2080 | ||
623fd807 GT |
2081 | config PERCPU_TEST |
2082 | tristate "Per cpu operations test" | |
2083 | depends on m && DEBUG_KERNEL | |
2084 | help | |
2085 | Enable this option to build test module which validates per-cpu | |
2086 | operations. | |
2087 | ||
2088 | If unsure, say N. | |
2089 | ||
881c5149 | 2090 | config ATOMIC64_SELFTEST |
55ded955 | 2091 | tristate "Perform an atomic64_t self-test" |
881c5149 | 2092 | help |
55ded955 GU |
2093 | Enable this option to test the atomic64_t functions at boot or |
2094 | at module load time. | |
881c5149 DH |
2095 | |
2096 | If unsure, say N. | |
2097 | ||
2098 | config ASYNC_RAID6_TEST | |
2099 | tristate "Self test for hardware accelerated raid6 recovery" | |
2100 | depends on ASYNC_RAID6_RECOV | |
2101 | select ASYNC_MEMCPY | |
a7f7f624 | 2102 | help |
881c5149 DH |
2103 | This is a one-shot self test that permutes through the |
2104 | recovery of all the possible two disk failure scenarios for a | |
2105 | N-disk array. Recovery is performed with the asynchronous | |
2106 | raid6 recovery routines, and will optionally use an offload | |
2107 | engine if one is available. | |
2108 | ||
2109 | If unsure, say N. | |
2110 | ||
64d1d77a AS |
2111 | config TEST_HEXDUMP |
2112 | tristate "Test functions located in the hexdump module at runtime" | |
2113 | ||
881c5149 DH |
2114 | config TEST_STRING_HELPERS |
2115 | tristate "Test functions located in the string_helpers module at runtime" | |
2116 | ||
0b0600c8 TH |
2117 | config TEST_STRSCPY |
2118 | tristate "Test strscpy*() family of functions at runtime" | |
2119 | ||
881c5149 DH |
2120 | config TEST_KSTRTOX |
2121 | tristate "Test kstrto*() family of functions at runtime" | |
2122 | ||
707cc728 RV |
2123 | config TEST_PRINTF |
2124 | tristate "Test printf() family of functions at runtime" | |
2125 | ||
5fd003f5 DD |
2126 | config TEST_BITMAP |
2127 | tristate "Test bitmap_*() family of functions at runtime" | |
5fd003f5 DD |
2128 | help |
2129 | Enable this option to test the bitmap functions at boot. | |
2130 | ||
2131 | If unsure, say N. | |
2132 | ||
cfaff0e5 AS |
2133 | config TEST_UUID |
2134 | tristate "Test functions located in the uuid module at runtime" | |
2135 | ||
ad3d6c72 MW |
2136 | config TEST_XARRAY |
2137 | tristate "Test the XArray code at runtime" | |
2138 | ||
455a35a6 RV |
2139 | config TEST_OVERFLOW |
2140 | tristate "Test check_*_overflow() functions at runtime" | |
2141 | ||
7e1e7763 | 2142 | config TEST_RHASHTABLE |
9d6dbe1b | 2143 | tristate "Perform selftest on resizable hash table" |
7e1e7763 TG |
2144 | help |
2145 | Enable this option to test the rhashtable functions at boot. | |
2146 | ||
2147 | If unsure, say N. | |
2148 | ||
468a9428 GS |
2149 | config TEST_HASH |
2150 | tristate "Perform selftest on hash functions" | |
468a9428 | 2151 | help |
2c956a60 JD |
2152 | Enable this option to test the kernel's integer (<linux/hash.h>), |
2153 | string (<linux/stringhash.h>), and siphash (<linux/siphash.h>) | |
2154 | hash functions on boot (or module load). | |
468a9428 GS |
2155 | |
2156 | This is intended to help people writing architecture-specific | |
2157 | optimized versions. If unsure, say N. | |
2158 | ||
8ab8ba38 MW |
2159 | config TEST_IDA |
2160 | tristate "Perform selftest on IDA functions" | |
2161 | ||
44091d29 JP |
2162 | config TEST_PARMAN |
2163 | tristate "Perform selftest on priority array manager" | |
44091d29 JP |
2164 | depends on PARMAN |
2165 | help | |
2166 | Enable this option to test priority array manager on boot | |
2167 | (or module load). | |
2168 | ||
2169 | If unsure, say N. | |
2170 | ||
6aed82de DL |
2171 | config TEST_IRQ_TIMINGS |
2172 | bool "IRQ timings selftest" | |
2173 | depends on IRQ_TIMINGS | |
2174 | help | |
2175 | Enable this option to test the irq timings code on boot. | |
2176 | ||
2177 | If unsure, say N. | |
2178 | ||
8a6f0b47 | 2179 | config TEST_LKM |
93e9ef83 | 2180 | tristate "Test module loading with 'hello world' module" |
93e9ef83 KC |
2181 | depends on m |
2182 | help | |
2183 | This builds the "test_module" module that emits "Hello, world" | |
2184 | on printk when loaded. It is designed to be used for basic | |
2185 | evaluation of the module loading subsystem (for example when | |
2186 | validating module verification). It lacks any extra dependencies, | |
2187 | and will not normally be loaded by the system unless explicitly | |
2188 | requested by name. | |
2189 | ||
2190 | If unsure, say N. | |
2191 | ||
c348c163 | 2192 | config TEST_BITOPS |
6af132f3 | 2193 | tristate "Test module for compilation of bitops operations" |
c348c163 JB |
2194 | depends on m |
2195 | help | |
2196 | This builds the "test_bitops" module that is much like the | |
2197 | TEST_LKM module except that it does a basic exercise of the | |
6af132f3 WY |
2198 | set/clear_bit macros and get_count_order/long to make sure there are |
2199 | no compiler warnings from C=1 sparse checker or -Wextra | |
2200 | compilations. It has no dependencies and doesn't run or load unless | |
2201 | explicitly requested by name. for example: modprobe test_bitops. | |
c348c163 JB |
2202 | |
2203 | If unsure, say N. | |
2204 | ||
3f21a6b7 URS |
2205 | config TEST_VMALLOC |
2206 | tristate "Test module for stress/performance analysis of vmalloc allocator" | |
2207 | default n | |
2208 | depends on MMU | |
2209 | depends on m | |
2210 | help | |
2211 | This builds the "test_vmalloc" module that should be used for | |
2212 | stress and performance analysis. So, any new change for vmalloc | |
2213 | subsystem can be evaluated from performance and stability point | |
2214 | of view. | |
2215 | ||
2216 | If unsure, say N. | |
2217 | ||
3e2a4c18 KC |
2218 | config TEST_USER_COPY |
2219 | tristate "Test user/kernel boundary protections" | |
3e2a4c18 KC |
2220 | depends on m |
2221 | help | |
2222 | This builds the "test_user_copy" module that runs sanity checks | |
2223 | on the copy_to/from_user infrastructure, making sure basic | |
2224 | user/kernel boundary testing is working. If it fails to load, | |
2225 | a regression has been detected in the user/kernel memory boundary | |
2226 | protections. | |
2227 | ||
2228 | If unsure, say N. | |
2229 | ||
64a8946b AS |
2230 | config TEST_BPF |
2231 | tristate "Test BPF filter functionality" | |
98920ba6 | 2232 | depends on m && NET |
64a8946b AS |
2233 | help |
2234 | This builds the "test_bpf" module that runs various test vectors | |
2235 | against the BPF interpreter or BPF JIT compiler depending on the | |
2236 | current setting. This is in particular useful for BPF JIT compiler | |
2237 | development, but also to run regression tests against changes in | |
3c731eba AS |
2238 | the interpreter code. It also enables test stubs for eBPF maps and |
2239 | verifier used by user space verifier testsuite. | |
64a8946b AS |
2240 | |
2241 | If unsure, say N. | |
2242 | ||
509e56b3 MB |
2243 | config TEST_BLACKHOLE_DEV |
2244 | tristate "Test blackhole netdev functionality" | |
2245 | depends on m && NET | |
2246 | help | |
2247 | This builds the "test_blackhole_dev" module that validates the | |
2248 | data path through this blackhole netdev. | |
2249 | ||
2250 | If unsure, say N. | |
2251 | ||
dceeb3e7 | 2252 | config FIND_BIT_BENCHMARK |
4441fca0 | 2253 | tristate "Test find_bit functions" |
4441fca0 YN |
2254 | help |
2255 | This builds the "test_find_bit" module that measure find_*_bit() | |
2256 | functions performance. | |
2257 | ||
2258 | If unsure, say N. | |
2259 | ||
0a8adf58 KC |
2260 | config TEST_FIRMWARE |
2261 | tristate "Test firmware loading via userspace interface" | |
0a8adf58 KC |
2262 | depends on FW_LOADER |
2263 | help | |
2264 | This builds the "test_firmware" module that creates a userspace | |
2265 | interface for testing firmware loading. This can be used to | |
2266 | control the triggering of firmware loading without needing an | |
2267 | actual firmware-using device. The contents can be rechecked by | |
2268 | userspace. | |
2269 | ||
2270 | If unsure, say N. | |
2271 | ||
9308f2f9 LR |
2272 | config TEST_SYSCTL |
2273 | tristate "sysctl test driver" | |
9308f2f9 LR |
2274 | depends on PROC_SYSCTL |
2275 | help | |
2276 | This builds the "test_sysctl" module. This driver enables to test the | |
2277 | proc sysctl interfaces available to drivers safely without affecting | |
2278 | production knobs which might alter system functionality. | |
2279 | ||
2280 | If unsure, say N. | |
2281 | ||
d2585f51 VMI |
2282 | config BITFIELD_KUNIT |
2283 | tristate "KUnit test bitfield functions at runtime" | |
2284 | depends on KUNIT | |
2285 | help | |
2286 | Enable this option to test the bitfield functions at boot. | |
2287 | ||
2288 | KUnit tests run during boot and output the results to the debug log | |
2289 | in TAP format (http://testanything.org/). Only useful for kernel devs | |
2290 | running the KUnit test harness, and not intended for inclusion into a | |
2291 | production build. | |
2292 | ||
2293 | For more information on KUnit and unit tests in general please refer | |
2294 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2295 | ||
2296 | If unsure, say N. | |
2297 | ||
5df38ca6 AS |
2298 | config RESOURCE_KUNIT_TEST |
2299 | tristate "KUnit test for resource API" | |
2300 | depends on KUNIT | |
2301 | help | |
2302 | This builds the resource API unit test. | |
2303 | Tests the logic of API provided by resource.c and ioport.h. | |
2304 | For more information on KUnit and unit tests in general please refer | |
2305 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2306 | ||
2307 | If unsure, say N. | |
2308 | ||
2cb80dbb | 2309 | config SYSCTL_KUNIT_TEST |
5f215aab | 2310 | tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS |
2cb80dbb | 2311 | depends on KUNIT |
5f215aab | 2312 | default KUNIT_ALL_TESTS |
2cb80dbb IZ |
2313 | help |
2314 | This builds the proc sysctl unit test, which runs on boot. | |
2315 | Tests the API contract and implementation correctness of sysctl. | |
2316 | For more information on KUnit and unit tests in general please refer | |
2317 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2318 | ||
2319 | If unsure, say N. | |
2320 | ||
ea2dd7c0 | 2321 | config LIST_KUNIT_TEST |
5f215aab | 2322 | tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS |
ea2dd7c0 | 2323 | depends on KUNIT |
5f215aab | 2324 | default KUNIT_ALL_TESTS |
ea2dd7c0 DG |
2325 | help |
2326 | This builds the linked list KUnit test suite. | |
2327 | It tests that the API and basic functionality of the list_head type | |
2328 | and associated macros. | |
2329 | ||
2330 | KUnit tests run during boot and output the results to the debug log | |
d89775fc | 2331 | in TAP format (https://testanything.org/). Only useful for kernel devs |
ea2dd7c0 DG |
2332 | running the KUnit test harness, and not intended for inclusion into a |
2333 | production build. | |
2334 | ||
2335 | For more information on KUnit and unit tests in general please refer | |
2336 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2337 | ||
2338 | If unsure, say N. | |
2339 | ||
33d599f0 MV |
2340 | config LINEAR_RANGES_TEST |
2341 | tristate "KUnit test for linear_ranges" | |
2342 | depends on KUNIT | |
2343 | select LINEAR_RANGES | |
2344 | help | |
2345 | This builds the linear_ranges unit test, which runs on boot. | |
2346 | Tests the linear_ranges logic correctness. | |
2347 | For more information on KUnit and unit tests in general please refer | |
7546861a AS |
2348 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
2349 | ||
2350 | If unsure, say N. | |
2351 | ||
2352 | config CMDLINE_KUNIT_TEST | |
2353 | tristate "KUnit test for cmdline API" | |
2354 | depends on KUNIT | |
2355 | help | |
2356 | This builds the cmdline API unit test. | |
2357 | Tests the logic of API provided by cmdline.c. | |
2358 | For more information on KUnit and unit tests in general please refer | |
33d599f0 MV |
2359 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
2360 | ||
2361 | If unsure, say N. | |
2362 | ||
6d511020 RF |
2363 | config BITS_TEST |
2364 | tristate "KUnit test for bits.h" | |
2365 | depends on KUNIT | |
2366 | help | |
2367 | This builds the bits unit test. | |
2368 | Tests the logic of macros defined in bits.h. | |
2369 | For more information on KUnit and unit tests in general please refer | |
2370 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2371 | ||
2372 | If unsure, say N. | |
2373 | ||
e704f93a DR |
2374 | config TEST_UDELAY |
2375 | tristate "udelay test driver" | |
e704f93a DR |
2376 | help |
2377 | This builds the "udelay_test" module that helps to make sure | |
2378 | that udelay() is working properly. | |
2379 | ||
2380 | If unsure, say N. | |
2381 | ||
2bf9e0ab IM |
2382 | config TEST_STATIC_KEYS |
2383 | tristate "Test static keys" | |
579e1acb JB |
2384 | depends on m |
2385 | help | |
2bf9e0ab | 2386 | Test the static key interfaces. |
579e1acb JB |
2387 | |
2388 | If unsure, say N. | |
2389 | ||
d9c6a72d LR |
2390 | config TEST_KMOD |
2391 | tristate "kmod stress tester" | |
d9c6a72d | 2392 | depends on m |
d9c6a72d | 2393 | depends on NETDEVICES && NET_CORE && INET # for TUN |
ae3d6a32 | 2394 | depends on BLOCK |
d9c6a72d LR |
2395 | select TEST_LKM |
2396 | select XFS_FS | |
2397 | select TUN | |
2398 | select BTRFS_FS | |
2399 | help | |
2400 | Test the kernel's module loading mechanism: kmod. kmod implements | |
2401 | support to load modules using the Linux kernel's usermode helper. | |
2402 | This test provides a series of tests against kmod. | |
2403 | ||
2404 | Although technically you can either build test_kmod as a module or | |
2405 | into the kernel we disallow building it into the kernel since | |
2406 | it stress tests request_module() and this will very likely cause | |
2407 | some issues by taking over precious threads available from other | |
2408 | module load requests, ultimately this could be fatal. | |
2409 | ||
2410 | To run tests run: | |
2411 | ||
2412 | tools/testing/selftests/kmod/kmod.sh --help | |
2413 | ||
2414 | If unsure, say N. | |
2415 | ||
e4dace36 FF |
2416 | config TEST_DEBUG_VIRTUAL |
2417 | tristate "Test CONFIG_DEBUG_VIRTUAL feature" | |
2418 | depends on DEBUG_VIRTUAL | |
2419 | help | |
2420 | Test the kernel's ability to detect incorrect calls to | |
2421 | virt_to_phys() done against the non-linear part of the | |
2422 | kernel's virtual address map. | |
2423 | ||
2424 | If unsure, say N. | |
2425 | ||
ce76d938 AS |
2426 | config TEST_MEMCAT_P |
2427 | tristate "Test memcat_p() helper function" | |
2428 | help | |
2429 | Test the memcat_p() helper for correctly merging two | |
2430 | pointer arrays together. | |
2431 | ||
2432 | If unsure, say N. | |
2433 | ||
a2818ee4 JL |
2434 | config TEST_LIVEPATCH |
2435 | tristate "Test livepatching" | |
2436 | default n | |
bae05437 | 2437 | depends on DYNAMIC_DEBUG |
a2818ee4 JL |
2438 | depends on LIVEPATCH |
2439 | depends on m | |
2440 | help | |
2441 | Test kernel livepatching features for correctness. The tests will | |
2442 | load test modules that will be livepatched in various scenarios. | |
2443 | ||
2444 | To run all the livepatching tests: | |
2445 | ||
2446 | make -C tools/testing/selftests TARGETS=livepatch run_tests | |
2447 | ||
2448 | Alternatively, individual tests may be invoked: | |
2449 | ||
2450 | tools/testing/selftests/livepatch/test-callbacks.sh | |
2451 | tools/testing/selftests/livepatch/test-livepatch.sh | |
2452 | tools/testing/selftests/livepatch/test-shadow-vars.sh | |
2453 | ||
2454 | If unsure, say N. | |
2455 | ||
0a020d41 JP |
2456 | config TEST_OBJAGG |
2457 | tristate "Perform selftest on object aggreration manager" | |
2458 | default n | |
2459 | depends on OBJAGG | |
2460 | help | |
2461 | Enable this option to test object aggregation manager on boot | |
2462 | (or module load). | |
2463 | ||
0a020d41 | 2464 | |
50ceaa95 KC |
2465 | config TEST_STACKINIT |
2466 | tristate "Test level of stack variable initialization" | |
2467 | help | |
2468 | Test if the kernel is zero-initializing stack variables and | |
2469 | padding. Coverage is controlled by compiler flags, | |
2470 | CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF, | |
2471 | or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL. | |
2472 | ||
2473 | If unsure, say N. | |
2474 | ||
5015a300 AP |
2475 | config TEST_MEMINIT |
2476 | tristate "Test heap/page initialization" | |
2477 | help | |
2478 | Test if the kernel is zero-initializing heap and page allocations. | |
2479 | This can be useful to test init_on_alloc and init_on_free features. | |
2480 | ||
2481 | If unsure, say N. | |
2482 | ||
b2ef9f5a RC |
2483 | config TEST_HMM |
2484 | tristate "Test HMM (Heterogeneous Memory Management)" | |
2485 | depends on TRANSPARENT_HUGEPAGE | |
2486 | depends on DEVICE_PRIVATE | |
2487 | select HMM_MIRROR | |
2488 | select MMU_NOTIFIER | |
2489 | help | |
2490 | This is a pseudo device driver solely for testing HMM. | |
2491 | Say M here if you want to build the HMM test module. | |
2492 | Doing so will allow you to run tools/testing/selftest/vm/hmm-tests. | |
2493 | ||
2494 | If unsure, say N. | |
2495 | ||
e320d301 MWO |
2496 | config TEST_FREE_PAGES |
2497 | tristate "Test freeing pages" | |
2498 | help | |
2499 | Test that a memory leak does not occur due to a race between | |
2500 | freeing a block of pages and a speculative page reference. | |
2501 | Loading this module is safe if your kernel has the bug fixed. | |
2502 | If the bug is not fixed, it will leak gigabytes of memory and | |
2503 | probably OOM your system. | |
2504 | ||
4185b3b9 PA |
2505 | config TEST_FPU |
2506 | tristate "Test floating point operations in kernel space" | |
2507 | depends on X86 && !KCOV_INSTRUMENT_ALL | |
2508 | help | |
2509 | Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu | |
2510 | which will trigger a sequence of floating point operations. This is used | |
2511 | for self-testing floating point control register setting in | |
2512 | kernel_fpu_begin(). | |
2513 | ||
2514 | If unsure, say N. | |
2515 | ||
d3deafaa | 2516 | endif # RUNTIME_TESTING_MENU |
cc3fa840 RD |
2517 | |
2518 | config MEMTEST | |
2519 | bool "Memtest" | |
a7f7f624 | 2520 | help |
cc3fa840 RD |
2521 | This option adds a kernel parameter 'memtest', which allows memtest |
2522 | to be set. | |
2523 | memtest=0, mean disabled; -- default | |
2524 | memtest=1, mean do 1 test pattern; | |
2525 | ... | |
2526 | memtest=17, mean do 17 test patterns. | |
2527 | If you are unsure how to answer this question, answer N. | |
2528 | ||
21266be9 | 2529 | |
06ec64b8 | 2530 | |
af9ca6f9 BB |
2531 | config HYPERV_TESTING |
2532 | bool "Microsoft Hyper-V driver testing" | |
2533 | default n | |
2534 | depends on HYPERV && DEBUG_FS | |
2535 | help | |
2536 | Select this option to enable Hyper-V vmbus testing. | |
2537 | ||
045f6d79 CD |
2538 | endmenu # "Kernel Testing and Coverage" |
2539 | ||
75442fb0 MCC |
2540 | source "Documentation/Kconfig" |
2541 | ||
06ec64b8 | 2542 | endmenu # Kernel hacking |