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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 | ||
22f4e66d SB |
38 | config STACKTRACE_BUILD_ID |
39 | bool "Show build ID information in stacktraces" | |
40 | depends on PRINTK | |
41 | help | |
42 | Selecting this option adds build ID information for symbols in | |
43 | stacktraces printed with the printk format '%p[SR]b'. | |
44 | ||
45 | This option is intended for distros where debuginfo is not easily | |
46 | accessible but can be downloaded given the build ID of the vmlinux or | |
47 | kernel module where the function is located. | |
48 | ||
a8cfdc68 OJ |
49 | config CONSOLE_LOGLEVEL_DEFAULT |
50 | int "Default console loglevel (1-15)" | |
51 | range 1 15 | |
52 | default "7" | |
53 | help | |
54 | Default loglevel to determine what will be printed on the console. | |
55 | ||
56 | Setting a default here is equivalent to passing in loglevel=<x> in | |
57 | the kernel bootargs. loglevel=<x> continues to override whatever | |
58 | value is specified here as well. | |
59 | ||
50f4d9bd | 60 | Note: This does not affect the log level of un-prefixed printk() |
a8cfdc68 OJ |
61 | usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT |
62 | option. | |
63 | ||
22eceb8b HG |
64 | config CONSOLE_LOGLEVEL_QUIET |
65 | int "quiet console loglevel (1-15)" | |
66 | range 1 15 | |
67 | default "4" | |
68 | help | |
69 | loglevel to use when "quiet" is passed on the kernel commandline. | |
70 | ||
71 | When "quiet" is passed on the kernel commandline this loglevel | |
72 | will be used as the loglevel. IOW passing "quiet" will be the | |
73 | equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>" | |
74 | ||
42a9dc0b | 75 | config MESSAGE_LOGLEVEL_DEFAULT |
5af5bcb8 MSB |
76 | int "Default message log level (1-7)" |
77 | range 1 7 | |
78 | default "4" | |
79 | help | |
80 | Default log level for printk statements with no specified priority. | |
81 | ||
82 | This was hard-coded to KERN_WARNING since at least 2.6.10 but folks | |
83 | that are auditing their logs closely may want to set it to a lower | |
84 | priority. | |
85 | ||
a8cfdc68 OJ |
86 | Note: This does not affect what message level gets printed on the console |
87 | by default. To change that, use loglevel=<x> in the kernel bootargs, | |
88 | or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value. | |
89 | ||
604ff0dc DH |
90 | config BOOT_PRINTK_DELAY |
91 | bool "Delay each boot printk message by N milliseconds" | |
92 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY | |
93 | help | |
94 | This build option allows you to read kernel boot messages | |
95 | by inserting a short delay after each one. The delay is | |
96 | specified in milliseconds on the kernel command line, | |
97 | using "boot_delay=N". | |
98 | ||
99 | It is likely that you would also need to use "lpj=M" to preset | |
100 | the "loops per jiffie" value. | |
101 | See a previous boot log for the "lpj" value to use for your | |
102 | system, and then set "lpj=M" before setting "boot_delay=N". | |
103 | NOTE: Using this option may adversely affect SMP systems. | |
104 | I.e., processors other than the first one may not boot up. | |
105 | BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect | |
106 | what it believes to be lockup conditions. | |
107 | ||
108 | config DYNAMIC_DEBUG | |
109 | bool "Enable dynamic printk() support" | |
110 | default n | |
111 | depends on PRINTK | |
239a5791 | 112 | depends on (DEBUG_FS || PROC_FS) |
ceabef7d | 113 | select DYNAMIC_DEBUG_CORE |
604ff0dc DH |
114 | help |
115 | ||
116 | Compiles debug level messages into the kernel, which would not | |
117 | otherwise be available at runtime. These messages can then be | |
118 | enabled/disabled based on various levels of scope - per source file, | |
119 | function, module, format string, and line number. This mechanism | |
120 | implicitly compiles in all pr_debug() and dev_dbg() calls, which | |
121 | enlarges the kernel text size by about 2%. | |
122 | ||
123 | If a source file is compiled with DEBUG flag set, any | |
124 | pr_debug() calls in it are enabled by default, but can be | |
125 | disabled at runtime as below. Note that DEBUG flag is | |
126 | turned on by many CONFIG_*DEBUG* options. | |
127 | ||
128 | Usage: | |
129 | ||
130 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, | |
239a5791 GKH |
131 | which is contained in the 'debugfs' filesystem or procfs. |
132 | Thus, the debugfs or procfs filesystem must first be mounted before | |
133 | making use of this feature. | |
604ff0dc DH |
134 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
135 | file contains a list of the debug statements that can be enabled. The | |
136 | format for each line of the file is: | |
137 | ||
138 | filename:lineno [module]function flags format | |
139 | ||
140 | filename : source file of the debug statement | |
141 | lineno : line number of the debug statement | |
142 | module : module that contains the debug statement | |
143 | function : function that contains the debug statement | |
68d4b3df KK |
144 | flags : '=p' means the line is turned 'on' for printing |
145 | format : the format used for the debug statement | |
604ff0dc DH |
146 | |
147 | From a live system: | |
148 | ||
149 | nullarbor:~ # cat <debugfs>/dynamic_debug/control | |
150 | # filename:lineno [module]function flags format | |
151 | fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012" | |
152 | fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012" | |
153 | fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012" | |
154 | ||
155 | Example usage: | |
156 | ||
157 | // enable the message at line 1603 of file svcsock.c | |
158 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > | |
159 | <debugfs>/dynamic_debug/control | |
160 | ||
161 | // enable all the messages in file svcsock.c | |
162 | nullarbor:~ # echo -n 'file svcsock.c +p' > | |
163 | <debugfs>/dynamic_debug/control | |
164 | ||
165 | // enable all the messages in the NFS server module | |
166 | nullarbor:~ # echo -n 'module nfsd +p' > | |
167 | <debugfs>/dynamic_debug/control | |
168 | ||
169 | // enable all 12 messages in the function svc_process() | |
170 | nullarbor:~ # echo -n 'func svc_process +p' > | |
171 | <debugfs>/dynamic_debug/control | |
172 | ||
173 | // disable all 12 messages in the function svc_process() | |
174 | nullarbor:~ # echo -n 'func svc_process -p' > | |
175 | <debugfs>/dynamic_debug/control | |
176 | ||
f8998c22 HH |
177 | See Documentation/admin-guide/dynamic-debug-howto.rst for additional |
178 | information. | |
604ff0dc | 179 | |
ceabef7d OZ |
180 | config DYNAMIC_DEBUG_CORE |
181 | bool "Enable core function of dynamic debug support" | |
182 | depends on PRINTK | |
183 | depends on (DEBUG_FS || PROC_FS) | |
184 | help | |
185 | Enable core functional support of dynamic debug. It is useful | |
186 | when you want to tie dynamic debug to your kernel modules with | |
187 | DYNAMIC_DEBUG_MODULE defined for each of them, especially for | |
188 | the case of embedded system where the kernel image size is | |
189 | sensitive for people. | |
190 | ||
57f5677e RV |
191 | config SYMBOLIC_ERRNAME |
192 | bool "Support symbolic error names in printf" | |
193 | default y if PRINTK | |
194 | help | |
195 | If you say Y here, the kernel's printf implementation will | |
196 | be able to print symbolic error names such as ENOSPC instead | |
197 | of the number 28. It makes the kernel image slightly larger | |
198 | (about 3KB), but can make the kernel logs easier to read. | |
199 | ||
2b05bb75 CD |
200 | config DEBUG_BUGVERBOSE |
201 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT | |
202 | depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) | |
203 | default y | |
204 | help | |
205 | Say Y here to make BUG() panics output the file name and line number | |
206 | of the BUG call as well as the EIP and oops trace. This aids | |
207 | debugging but costs about 70-100K of memory. | |
208 | ||
604ff0dc DH |
209 | endmenu # "printk and dmesg options" |
210 | ||
f9b3cd24 KC |
211 | config DEBUG_KERNEL |
212 | bool "Kernel debugging" | |
213 | help | |
214 | Say Y here if you are developing drivers or trying to debug and | |
215 | identify kernel problems. | |
216 | ||
217 | config DEBUG_MISC | |
218 | bool "Miscellaneous debug code" | |
219 | default DEBUG_KERNEL | |
220 | depends on DEBUG_KERNEL | |
221 | help | |
222 | Say Y here if you need to enable miscellaneous debug code that should | |
223 | be under a more specific debug option but isn't. | |
224 | ||
6dfc0665 DH |
225 | menu "Compile-time checks and compiler options" |
226 | ||
227 | config DEBUG_INFO | |
f9b3cd24 | 228 | bool |
6dfc0665 | 229 | help |
f9b3cd24 KC |
230 | A kernel debug info option other than "None" has been selected |
231 | in the "Debug information" choice below, indicating that debug | |
232 | information will be generated for build targets. | |
233 | ||
0a6de78c NC |
234 | # Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which |
235 | # some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215 | |
236 | config AS_HAS_NON_CONST_LEB128 | |
237 | def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:) | |
238 | ||
f9b3cd24 KC |
239 | choice |
240 | prompt "Debug information" | |
241 | depends on DEBUG_KERNEL | |
242 | help | |
243 | Selecting something other than "None" results in a kernel image | |
244 | that will include debugging info resulting in a larger kernel image. | |
6dfc0665 DH |
245 | This adds debug symbols to the kernel and modules (gcc -g), and |
246 | is needed if you intend to use kernel crashdump or binary object | |
247 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. | |
6dfc0665 | 248 | |
f9b3cd24 KC |
249 | Choose which version of DWARF debug info to emit. If unsure, |
250 | select "Toolchain default". | |
251 | ||
252 | config DEBUG_INFO_NONE | |
253 | bool "Disable debug information" | |
254 | help | |
255 | Do not build the kernel with debugging information, which will | |
256 | result in a faster and smaller build. | |
257 | ||
258 | config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT | |
259 | bool "Rely on the toolchain's implicit default DWARF version" | |
260 | select DEBUG_INFO | |
0a6de78c | 261 | depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128) |
f9b3cd24 KC |
262 | help |
263 | The implicit default version of DWARF debug info produced by a | |
264 | toolchain changes over time. | |
265 | ||
266 | This can break consumers of the debug info that haven't upgraded to | |
267 | support newer revisions, and prevent testing newer versions, but | |
268 | those should be less common scenarios. | |
269 | ||
270 | config DEBUG_INFO_DWARF4 | |
271 | bool "Generate DWARF Version 4 debuginfo" | |
272 | select DEBUG_INFO | |
4f001a21 | 273 | depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502) |
f9b3cd24 | 274 | help |
32ef9e50 ND |
275 | Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2 |
276 | if using clang without clang's integrated assembler, and gdb 7.0+. | |
f9b3cd24 KC |
277 | |
278 | If you have consumers of DWARF debug info that are not ready for | |
279 | newer revisions of DWARF, you may wish to choose this or have your | |
280 | config select this. | |
281 | ||
282 | config DEBUG_INFO_DWARF5 | |
283 | bool "Generate DWARF Version 5 debuginfo" | |
284 | select DEBUG_INFO | |
0a6de78c | 285 | depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128) |
f9b3cd24 KC |
286 | help |
287 | Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc | |
288 | 5.0+ accepts the -gdwarf-5 flag but only had partial support for some | |
289 | draft features until 7.0), and gdb 8.0+. | |
290 | ||
291 | Changes to the structure of debug info in Version 5 allow for around | |
292 | 15-18% savings in resulting image and debug info section sizes as | |
293 | compared to DWARF Version 4. DWARF Version 5 standardizes previous | |
294 | extensions such as accelerators for symbol indexing and the format | |
295 | for fission (.dwo/.dwp) files. Users may not want to select this | |
296 | config if they rely on tooling that has not yet been updated to | |
297 | support DWARF Version 5. | |
298 | ||
299 | endchoice # "Debug information" | |
6dfc0665 | 300 | |
695afd3d SD |
301 | if DEBUG_INFO |
302 | ||
6dfc0665 DH |
303 | config DEBUG_INFO_REDUCED |
304 | bool "Reduce debugging information" | |
6dfc0665 DH |
305 | help |
306 | If you say Y here gcc is instructed to generate less debugging | |
307 | information for structure types. This means that tools that | |
308 | need full debugging information (like kgdb or systemtap) won't | |
309 | be happy. But if you merely need debugging information to | |
310 | resolve line numbers there is no loss. Advantage is that | |
311 | build directory object sizes shrink dramatically over a full | |
312 | DEBUG_INFO build and compile times are reduced too. | |
313 | Only works with newer gcc versions. | |
314 | ||
9f8fe647 ND |
315 | choice |
316 | prompt "Compressed Debug information" | |
317 | help | |
318 | Compress the resulting debug info. Results in smaller debug info sections, | |
319 | but requires that consumers are able to decompress the results. | |
320 | ||
321 | If unsure, choose DEBUG_INFO_COMPRESSED_NONE. | |
322 | ||
323 | config DEBUG_INFO_COMPRESSED_NONE | |
324 | bool "Don't compress debug information" | |
325 | help | |
326 | Don't compress debug info sections. | |
327 | ||
328 | config DEBUG_INFO_COMPRESSED_ZLIB | |
329 | bool "Compress debugging information with zlib" | |
10e68b02 | 330 | depends on $(cc-option,-gz=zlib) |
10e68b02 ND |
331 | depends on $(ld-option,--compress-debug-sections=zlib) |
332 | help | |
333 | Compress the debug information using zlib. Requires GCC 5.0+ or Clang | |
334 | 5.0+, binutils 2.26+, and zlib. | |
335 | ||
336 | Users of dpkg-deb via scripts/package/builddeb may find an increase in | |
337 | size of their debug .deb packages with this config set, due to the | |
338 | debug info being compressed with zlib, then the object files being | |
339 | recompressed with a different compression scheme. But this is still | |
340 | preferable to setting $KDEB_COMPRESS to "none" which would be even | |
341 | larger. | |
342 | ||
9f8fe647 ND |
343 | config DEBUG_INFO_COMPRESSED_ZSTD |
344 | bool "Compress debugging information with zstd" | |
345 | depends on $(cc-option,-gz=zstd) | |
346 | depends on $(ld-option,--compress-debug-sections=zstd) | |
347 | help | |
348 | Compress the debug information using zstd. This may provide better | |
349 | compression than zlib, for about the same time costs, but requires newer | |
350 | toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and | |
351 | zstd. | |
352 | ||
353 | endchoice # "Compressed Debug information" | |
354 | ||
866ced95 AK |
355 | config DEBUG_INFO_SPLIT |
356 | bool "Produce split debuginfo in .dwo files" | |
9d937444 | 357 | depends on $(cc-option,-gsplit-dwarf) |
866ced95 AK |
358 | help |
359 | Generate debug info into separate .dwo files. This significantly | |
360 | reduces the build directory size for builds with DEBUG_INFO, | |
361 | because it stores the information only once on disk in .dwo | |
362 | files instead of multiple times in object files and executables. | |
363 | In addition the debug information is also compressed. | |
364 | ||
365 | Requires recent gcc (4.7+) and recent gdb/binutils. | |
366 | Any tool that packages or reads debug information would need | |
367 | to know about the .dwo files and include them. | |
368 | Incompatible with older versions of ccache. | |
369 | ||
e83b9f55 AN |
370 | config DEBUG_INFO_BTF |
371 | bool "Generate BTF typeinfo" | |
7d32e693 SB |
372 | depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED |
373 | depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST | |
d9847eb8 | 374 | depends on BPF_SYSCALL |
52deda95 | 375 | depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121 |
e83b9f55 AN |
376 | help |
377 | Generate deduplicated BTF type information from DWARF debug info. | |
378 | Turning this on expects presence of pahole tool, which will convert | |
379 | DWARF type info into equivalent deduplicated BTF type info. | |
380 | ||
5f9ae91f | 381 | config PAHOLE_HAS_SPLIT_BTF |
6323c813 | 382 | def_bool PAHOLE_VERSION >= 119 |
5f9ae91f | 383 | |
7472d5a6 | 384 | config PAHOLE_HAS_BTF_TAG |
6323c813 | 385 | def_bool PAHOLE_VERSION >= 123 |
7472d5a6 YS |
386 | depends on CC_IS_CLANG |
387 | help | |
388 | Decide whether pahole emits btf_tag attributes (btf_type_tag and | |
389 | btf_decl_tag) or not. Currently only clang compiler implements | |
390 | these attributes, so make the config depend on CC_IS_CLANG. | |
5f9ae91f AN |
391 | |
392 | config DEBUG_INFO_BTF_MODULES | |
393 | def_bool y | |
394 | depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF | |
395 | help | |
396 | Generate compact split BTF type information for kernel modules. | |
397 | ||
5e214f2e CB |
398 | config MODULE_ALLOW_BTF_MISMATCH |
399 | bool "Allow loading modules with non-matching BTF type info" | |
400 | depends on DEBUG_INFO_BTF_MODULES | |
401 | help | |
402 | For modules whose split BTF does not match vmlinux, load without | |
403 | BTF rather than refusing to load. The default behavior with | |
404 | module BTF enabled is to reject modules with such mismatches; | |
405 | this option will still load module BTF where possible but ignore | |
406 | it when a mismatch is found. | |
407 | ||
3ee7b3fa JK |
408 | config GDB_SCRIPTS |
409 | bool "Provide GDB scripts for kernel debugging" | |
3ee7b3fa JK |
410 | help |
411 | This creates the required links to GDB helper scripts in the | |
412 | build directory. If you load vmlinux into gdb, the helper | |
413 | scripts will be automatically imported by gdb as well, and | |
414 | additional functions are available to analyze a Linux kernel | |
700199b0 AP |
415 | instance. See Documentation/dev-tools/gdb-kernel-debugging.rst |
416 | for further details. | |
3ee7b3fa | 417 | |
695afd3d SD |
418 | endif # DEBUG_INFO |
419 | ||
35bb5b1e | 420 | config FRAME_WARN |
a83e4ca2 | 421 | int "Warn for stack frames larger than" |
35bb5b1e | 422 | range 0 8192 |
ac66998d | 423 | default 0 if KMSAN |
0e07f663 | 424 | default 2048 if GCC_PLUGIN_LATENT_ENTROPY |
8d192bec HD |
425 | default 2048 if PARISC |
426 | default 1536 if (!64BIT && XTENSA) | |
152fe65f | 427 | default 1280 if KASAN && !64BIT |
8d192bec | 428 | default 1024 if !64BIT |
35bb5b1e AK |
429 | default 2048 if 64BIT |
430 | help | |
921757bc | 431 | Tell the compiler to warn at build time for stack frames larger than this. |
35bb5b1e AK |
432 | Setting this too low will cause a lot of warnings. |
433 | Setting it to 0 disables the warning. | |
35bb5b1e | 434 | |
99657c78 RD |
435 | config STRIP_ASM_SYMS |
436 | bool "Strip assembler-generated symbols during link" | |
437 | default n | |
438 | help | |
439 | Strip internal assembler-generated symbols during a link (symbols | |
440 | that look like '.Lxxx') so they don't pollute the output of | |
441 | get_wchan() and suchlike. | |
442 | ||
1873e870 | 443 | config READABLE_ASM |
68d4b3df KK |
444 | bool "Generate readable assembler code" |
445 | depends on DEBUG_KERNEL | |
7d73c3e9 | 446 | depends on CC_IS_GCC |
bf4735a4 | 447 | help |
68d4b3df KK |
448 | Disable some compiler optimizations that tend to generate human unreadable |
449 | assembler output. This may make the kernel slightly slower, but it helps | |
450 | to keep kernel developers who have to stare a lot at assembler listings | |
451 | sane. | |
bf4735a4 | 452 | |
e949f4c2 MY |
453 | config HEADERS_INSTALL |
454 | bool "Install uapi headers to usr/include" | |
bf4735a4 DM |
455 | depends on !UML |
456 | help | |
e949f4c2 MY |
457 | This option will install uapi headers (headers exported to user-space) |
458 | into the usr/include directory for use during the kernel build. | |
459 | This is unneeded for building the kernel itself, but needed for some | |
460 | user-space program samples. It is also needed by some features such | |
461 | as uapi header sanity checks. | |
462 | ||
91341d4b SR |
463 | config DEBUG_SECTION_MISMATCH |
464 | bool "Enable full Section mismatch analysis" | |
7d73c3e9 | 465 | depends on CC_IS_GCC |
91341d4b SR |
466 | help |
467 | The section mismatch analysis checks if there are illegal | |
468 | references from one section to another section. | |
e809ab01 MW |
469 | During linktime or runtime, some sections are dropped; |
470 | any use of code/data previously in these sections would | |
91341d4b | 471 | most likely result in an oops. |
e809ab01 | 472 | In the code, functions and variables are annotated with |
0db0628d | 473 | __init,, etc. (see the full list in include/linux/init.h), |
d6fbfa4f | 474 | which results in the code/data being placed in specific sections. |
e809ab01 MW |
475 | The section mismatch analysis is always performed after a full |
476 | kernel build, and enabling this option causes the following | |
b7dca6dd | 477 | additional step to occur: |
e809ab01 MW |
478 | - Add the option -fno-inline-functions-called-once to gcc commands. |
479 | When inlining a function annotated with __init in a non-init | |
480 | function, we would lose the section information and thus | |
91341d4b | 481 | the analysis would not catch the illegal reference. |
e809ab01 MW |
482 | This option tells gcc to inline less (but it does result in |
483 | a larger kernel). | |
91341d4b | 484 | |
47490ec1 NB |
485 | config SECTION_MISMATCH_WARN_ONLY |
486 | bool "Make section mismatch errors non-fatal" | |
487 | default y | |
488 | help | |
489 | If you say N here, the build process will fail if there are any | |
490 | section mismatch, instead of just throwing warnings. | |
491 | ||
492 | If unsure, say Y. | |
493 | ||
cf536e18 | 494 | config DEBUG_FORCE_FUNCTION_ALIGN_64B |
1bf18da6 FT |
495 | bool "Force all function address 64B aligned" |
496 | depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC) | |
d49a0626 | 497 | select FUNCTION_ALIGNMENT_64B |
09c60546 FT |
498 | help |
499 | There are cases that a commit from one domain changes the function | |
500 | address alignment of other domains, and cause magic performance | |
501 | bump (regression or improvement). Enable this option will help to | |
502 | verify if the bump is caused by function alignment changes, while | |
503 | it will slightly increase the kernel size and affect icache usage. | |
504 | ||
505 | It is mainly for debug and performance tuning use. | |
506 | ||
6dfc0665 DH |
507 | # |
508 | # Select this config option from the architecture Kconfig, if it | |
509 | # is preferred to always offer frame pointers as a config | |
510 | # option on the architecture (regardless of KERNEL_DEBUG): | |
511 | # | |
512 | config ARCH_WANT_FRAME_POINTERS | |
513 | bool | |
f346f4b3 | 514 | |
6dfc0665 DH |
515 | config FRAME_POINTER |
516 | bool "Compile the kernel with frame pointers" | |
a687a533 | 517 | depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS |
6dfc0665 | 518 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
a304e1b8 | 519 | help |
6dfc0665 DH |
520 | If you say Y here the resulting kernel image will be slightly |
521 | larger and slower, but it gives very useful debugging information | |
522 | in case of kernel bugs. (precise oopses/stacktraces/warnings) | |
a304e1b8 | 523 | |
03f16cd0 JP |
524 | config OBJTOOL |
525 | bool | |
526 | ||
b9ab5ebb JP |
527 | config STACK_VALIDATION |
528 | bool "Compile-time stack metadata validation" | |
03f16cd0 JP |
529 | depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER |
530 | select OBJTOOL | |
b9ab5ebb JP |
531 | default n |
532 | help | |
03f16cd0 JP |
533 | Validate frame pointer rules at compile-time. This helps ensure that |
534 | runtime stack traces are more reliable. | |
ee9f8fce | 535 | |
b9ab5ebb | 536 | For more information, see |
d6a21f2d | 537 | tools/objtool/Documentation/objtool.txt. |
b9ab5ebb | 538 | |
0f620cef | 539 | config NOINSTR_VALIDATION |
6804c1af | 540 | bool |
489e355b | 541 | depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY |
03f16cd0 | 542 | select OBJTOOL |
6804c1af PZ |
543 | default y |
544 | ||
5cc12472 RV |
545 | config VMLINUX_MAP |
546 | bool "Generate vmlinux.map file when linking" | |
547 | depends on EXPERT | |
548 | help | |
549 | Selecting this option will pass "-Map=vmlinux.map" to ld | |
550 | when linking vmlinux. That file can be useful for verifying | |
551 | and debugging magic section games, and for seeing which | |
552 | pieces of code get eliminated with | |
553 | CONFIG_LD_DEAD_CODE_DATA_ELIMINATION. | |
554 | ||
6dfc0665 DH |
555 | config DEBUG_FORCE_WEAK_PER_CPU |
556 | bool "Force weak per-cpu definitions" | |
557 | depends on DEBUG_KERNEL | |
8446f1d3 | 558 | help |
6dfc0665 DH |
559 | s390 and alpha require percpu variables in modules to be |
560 | defined weak to work around addressing range issue which | |
561 | puts the following two restrictions on percpu variable | |
562 | definitions. | |
8446f1d3 | 563 | |
6dfc0665 DH |
564 | 1. percpu symbols must be unique whether static or not |
565 | 2. percpu variables can't be defined inside a function | |
8446f1d3 | 566 | |
6dfc0665 DH |
567 | To ensure that generic code follows the above rules, this |
568 | option forces all percpu variables to be defined as weak. | |
5f329089 | 569 | |
6dfc0665 | 570 | endmenu # "Compiler options" |
8446f1d3 | 571 | |
6210b640 CD |
572 | menu "Generic Kernel Debugging Instruments" |
573 | ||
6dfc0665 DH |
574 | config MAGIC_SYSRQ |
575 | bool "Magic SysRq key" | |
576 | depends on !UML | |
577 | help | |
578 | If you say Y here, you will have some control over the system even | |
579 | if the system crashes for example during kernel debugging (e.g., you | |
580 | will be able to flush the buffer cache to disk, reboot the system | |
581 | immediately or dump some status information). This is accomplished | |
582 | by pressing various keys while holding SysRq (Alt+PrintScreen). It | |
583 | also works on a serial console (on PC hardware at least), if you | |
584 | send a BREAK and then within 5 seconds a command keypress. The | |
f8998c22 HH |
585 | keys are documented in <file:Documentation/admin-guide/sysrq.rst>. |
586 | Don't say Y unless you really know what this hack does. | |
8446f1d3 | 587 | |
8eaede49 BH |
588 | config MAGIC_SYSRQ_DEFAULT_ENABLE |
589 | hex "Enable magic SysRq key functions by default" | |
590 | depends on MAGIC_SYSRQ | |
591 | default 0x1 | |
592 | help | |
593 | Specifies which SysRq key functions are enabled by default. | |
594 | This may be set to 1 or 0 to enable or disable them all, or | |
f8998c22 | 595 | to a bitmask as described in Documentation/admin-guide/sysrq.rst. |
8eaede49 | 596 | |
732dbf3a FF |
597 | config MAGIC_SYSRQ_SERIAL |
598 | bool "Enable magic SysRq key over serial" | |
599 | depends on MAGIC_SYSRQ | |
600 | default y | |
601 | help | |
602 | Many embedded boards have a disconnected TTL level serial which can | |
603 | generate some garbage that can lead to spurious false sysrq detects. | |
604 | This option allows you to decide whether you want to enable the | |
605 | magic SysRq key. | |
606 | ||
68af4317 DS |
607 | config MAGIC_SYSRQ_SERIAL_SEQUENCE |
608 | string "Char sequence that enables magic SysRq over serial" | |
609 | depends on MAGIC_SYSRQ_SERIAL | |
610 | default "" | |
611 | help | |
612 | Specifies a sequence of characters that can follow BREAK to enable | |
613 | SysRq on a serial console. | |
614 | ||
d3394b3d DS |
615 | If unsure, leave an empty string and the option will not be enabled. |
616 | ||
ec29a5c1 CD |
617 | config DEBUG_FS |
618 | bool "Debug Filesystem" | |
619 | help | |
620 | debugfs is a virtual file system that kernel developers use to put | |
621 | debugging files into. Enable this option to be able to read and | |
622 | write to these files. | |
623 | ||
624 | For detailed documentation on the debugfs API, see | |
625 | Documentation/filesystems/. | |
626 | ||
627 | If unsure, say N. | |
628 | ||
a24c6f7b PE |
629 | choice |
630 | prompt "Debugfs default access" | |
631 | depends on DEBUG_FS | |
632 | default DEBUG_FS_ALLOW_ALL | |
633 | help | |
634 | This selects the default access restrictions for debugfs. | |
635 | It can be overridden with kernel command line option | |
636 | debugfs=[on,no-mount,off]. The restrictions apply for API access | |
637 | and filesystem registration. | |
638 | ||
639 | config DEBUG_FS_ALLOW_ALL | |
640 | bool "Access normal" | |
641 | help | |
642 | No restrictions apply. Both API and filesystem registration | |
643 | is on. This is the normal default operation. | |
644 | ||
645 | config DEBUG_FS_DISALLOW_MOUNT | |
646 | bool "Do not register debugfs as filesystem" | |
647 | help | |
648 | The API is open but filesystem is not loaded. Clients can still do | |
649 | their work and read with debug tools that do not need | |
650 | debugfs filesystem. | |
651 | ||
652 | config DEBUG_FS_ALLOW_NONE | |
653 | bool "No access" | |
654 | help | |
655 | Access is off. Clients get -PERM when trying to create nodes in | |
656 | debugfs tree and debugfs is not registered as a filesystem. | |
657 | Client can then back-off or continue without debugfs access. | |
658 | ||
659 | endchoice | |
660 | ||
6210b640 | 661 | source "lib/Kconfig.kgdb" |
6210b640 | 662 | source "lib/Kconfig.ubsan" |
2645d432 | 663 | source "lib/Kconfig.kcsan" |
6210b640 CD |
664 | |
665 | endmenu | |
666 | ||
4d92b95f ED |
667 | menu "Networking Debugging" |
668 | ||
669 | source "net/Kconfig.debug" | |
670 | ||
671 | endmenu # "Networking Debugging" | |
c66d7a27 | 672 | |
0610c8a8 | 673 | menu "Memory Debugging" |
fef2c9bc | 674 | |
8636a1f9 | 675 | source "mm/Kconfig.debug" |
fef2c9bc | 676 | |
0610c8a8 DH |
677 | config DEBUG_OBJECTS |
678 | bool "Debug object operations" | |
679 | depends on DEBUG_KERNEL | |
9c44bc03 | 680 | help |
0610c8a8 DH |
681 | If you say Y here, additional code will be inserted into the |
682 | kernel to track the life time of various objects and validate | |
683 | the operations on those objects. | |
9c44bc03 | 684 | |
0610c8a8 DH |
685 | config DEBUG_OBJECTS_SELFTEST |
686 | bool "Debug objects selftest" | |
687 | depends on DEBUG_OBJECTS | |
688 | help | |
689 | This enables the selftest of the object debug code. | |
9c44bc03 | 690 | |
0610c8a8 DH |
691 | config DEBUG_OBJECTS_FREE |
692 | bool "Debug objects in freed memory" | |
693 | depends on DEBUG_OBJECTS | |
694 | help | |
695 | This enables checks whether a k/v free operation frees an area | |
696 | which contains an object which has not been deactivated | |
697 | properly. This can make kmalloc/kfree-intensive workloads | |
698 | much slower. | |
3ac7fe5a | 699 | |
c6f3a97f TG |
700 | config DEBUG_OBJECTS_TIMERS |
701 | bool "Debug timer objects" | |
702 | depends on DEBUG_OBJECTS | |
703 | help | |
704 | If you say Y here, additional code will be inserted into the | |
705 | timer routines to track the life time of timer objects and | |
706 | validate the timer operations. | |
707 | ||
dc186ad7 TG |
708 | config DEBUG_OBJECTS_WORK |
709 | bool "Debug work objects" | |
710 | depends on DEBUG_OBJECTS | |
711 | help | |
712 | If you say Y here, additional code will be inserted into the | |
713 | work queue routines to track the life time of work objects and | |
714 | validate the work operations. | |
715 | ||
551d55a9 MD |
716 | config DEBUG_OBJECTS_RCU_HEAD |
717 | bool "Debug RCU callbacks objects" | |
fc2ecf7e | 718 | depends on DEBUG_OBJECTS |
551d55a9 MD |
719 | help |
720 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). | |
721 | ||
e2852ae8 TH |
722 | config DEBUG_OBJECTS_PERCPU_COUNTER |
723 | bool "Debug percpu counter objects" | |
724 | depends on DEBUG_OBJECTS | |
725 | help | |
726 | If you say Y here, additional code will be inserted into the | |
727 | percpu counter routines to track the life time of percpu counter | |
728 | objects and validate the percpu counter operations. | |
729 | ||
3ae70205 IM |
730 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
731 | int "debug_objects bootup default value (0-1)" | |
68d4b3df KK |
732 | range 0 1 |
733 | default "1" | |
734 | depends on DEBUG_OBJECTS | |
735 | help | |
736 | Debug objects boot parameter default value | |
3ae70205 | 737 | |
5035ebc6 | 738 | config SHRINKER_DEBUG |
5035ebc6 RG |
739 | bool "Enable shrinker debugging support" |
740 | depends on DEBUG_FS | |
741 | help | |
742 | Say Y to enable the shrinker debugfs interface which provides | |
743 | visibility into the kernel memory shrinkers subsystem. | |
744 | Disable it to avoid an extra memory footprint. | |
745 | ||
b69ec42b CM |
746 | config HAVE_DEBUG_KMEMLEAK |
747 | bool | |
748 | ||
3bba00d7 CM |
749 | config DEBUG_KMEMLEAK |
750 | bool "Kernel memory leak detector" | |
525c1f92 | 751 | depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK |
79e0d9bd | 752 | select DEBUG_FS |
3bba00d7 CM |
753 | select STACKTRACE if STACKTRACE_SUPPORT |
754 | select KALLSYMS | |
b60e26a2 | 755 | select CRC32 |
56a61617 | 756 | select STACKDEPOT |
993f57e0 | 757 | select STACKDEPOT_ALWAYS_INIT if !DEBUG_KMEMLEAK_DEFAULT_OFF |
3bba00d7 CM |
758 | help |
759 | Say Y here if you want to enable the memory leak | |
760 | detector. The memory allocation/freeing is traced in a way | |
761 | similar to the Boehm's conservative garbage collector, the | |
762 | difference being that the orphan objects are not freed but | |
763 | only shown in /sys/kernel/debug/kmemleak. Enabling this | |
764 | feature will introduce an overhead to memory | |
700199b0 | 765 | allocations. See Documentation/dev-tools/kmemleak.rst for more |
3bba00d7 CM |
766 | details. |
767 | ||
0610c8a8 DH |
768 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
769 | of finding leaks due to the slab objects poisoning. | |
770 | ||
771 | In order to access the kmemleak file, debugfs needs to be | |
772 | mounted (usually at /sys/kernel/debug). | |
773 | ||
c5665868 CM |
774 | config DEBUG_KMEMLEAK_MEM_POOL_SIZE |
775 | int "Kmemleak memory pool size" | |
0610c8a8 | 776 | depends on DEBUG_KMEMLEAK |
c59180ae | 777 | range 200 1000000 |
b751c52b | 778 | default 16000 |
0610c8a8 DH |
779 | help |
780 | Kmemleak must track all the memory allocations to avoid | |
781 | reporting false positives. Since memory may be allocated or | |
c5665868 CM |
782 | freed before kmemleak is fully initialised, use a static pool |
783 | of metadata objects to track such callbacks. After kmemleak is | |
784 | fully initialised, this memory pool acts as an emergency one | |
785 | if slab allocations fail. | |
0610c8a8 DH |
786 | |
787 | config DEBUG_KMEMLEAK_TEST | |
788 | tristate "Simple test for the kernel memory leak detector" | |
789 | depends on DEBUG_KMEMLEAK && m | |
790 | help | |
791 | This option enables a module that explicitly leaks memory. | |
792 | ||
793 | If unsure, say N. | |
794 | ||
795 | config DEBUG_KMEMLEAK_DEFAULT_OFF | |
796 | bool "Default kmemleak to off" | |
797 | depends on DEBUG_KMEMLEAK | |
798 | help | |
799 | Say Y here to disable kmemleak by default. It can then be enabled | |
800 | on the command line via kmemleak=on. | |
801 | ||
d53ce042 SK |
802 | config DEBUG_KMEMLEAK_AUTO_SCAN |
803 | bool "Enable kmemleak auto scan thread on boot up" | |
804 | default y | |
805 | depends on DEBUG_KMEMLEAK | |
806 | help | |
807 | Depending on the cpu, kmemleak scan may be cpu intensive and can | |
808 | stall user tasks at times. This option enables/disables automatic | |
809 | kmemleak scan at boot up. | |
810 | ||
811 | Say N here to disable kmemleak auto scan thread to stop automatic | |
812 | scanning. Disabling this option disables automatic reporting of | |
813 | memory leaks. | |
814 | ||
815 | If unsure, say Y. | |
816 | ||
0610c8a8 DH |
817 | config DEBUG_STACK_USAGE |
818 | bool "Stack utilization instrumentation" | |
6c31da34 | 819 | depends on DEBUG_KERNEL && !IA64 |
0610c8a8 DH |
820 | help |
821 | Enables the display of the minimum amount of free stack which each | |
822 | task has ever had available in the sysrq-T and sysrq-P debug output. | |
823 | ||
824 | This option will slow down process creation somewhat. | |
825 | ||
dc9b9638 CD |
826 | config SCHED_STACK_END_CHECK |
827 | bool "Detect stack corruption on calls to schedule()" | |
828 | depends on DEBUG_KERNEL | |
829 | default n | |
830 | help | |
831 | This option checks for a stack overrun on calls to schedule(). | |
832 | If the stack end location is found to be over written always panic as | |
833 | the content of the corrupted region can no longer be trusted. | |
834 | This is to ensure no erroneous behaviour occurs which could result in | |
835 | data corruption or a sporadic crash at a later stage once the region | |
836 | is examined. The runtime overhead introduced is minimal. | |
837 | ||
399145f9 AK |
838 | config ARCH_HAS_DEBUG_VM_PGTABLE |
839 | bool | |
840 | help | |
841 | An architecture should select this when it can successfully | |
842 | build and run DEBUG_VM_PGTABLE. | |
843 | ||
a738e9ba TG |
844 | config DEBUG_VM_IRQSOFF |
845 | def_bool DEBUG_VM && !PREEMPT_RT | |
846 | ||
0610c8a8 DH |
847 | config DEBUG_VM |
848 | bool "Debug VM" | |
849 | depends on DEBUG_KERNEL | |
850 | help | |
851 | Enable this to turn on extended checks in the virtual-memory system | |
68d4b3df | 852 | that may impact performance. |
0610c8a8 DH |
853 | |
854 | If unsure, say N. | |
855 | ||
54a611b6 LH |
856 | config DEBUG_VM_MAPLE_TREE |
857 | bool "Debug VM maple trees" | |
4f115147 | 858 | depends on DEBUG_VM |
54a611b6 | 859 | select DEBUG_MAPLE_TREE |
4f115147 | 860 | help |
54a611b6 | 861 | Enable VM maple tree debugging information and extra validations. |
4f115147 DB |
862 | |
863 | If unsure, say N. | |
864 | ||
0610c8a8 DH |
865 | config DEBUG_VM_RB |
866 | bool "Debug VM red-black trees" | |
867 | depends on DEBUG_VM | |
868 | help | |
a663dad6 | 869 | Enable VM red-black tree debugging information and extra validations. |
0610c8a8 DH |
870 | |
871 | If unsure, say N. | |
872 | ||
95ad9755 KS |
873 | config DEBUG_VM_PGFLAGS |
874 | bool "Debug page-flags operations" | |
875 | depends on DEBUG_VM | |
876 | help | |
877 | Enables extra validation on page flags operations. | |
878 | ||
879 | If unsure, say N. | |
880 | ||
399145f9 AK |
881 | config DEBUG_VM_PGTABLE |
882 | bool "Debug arch page table for semantics compliance" | |
883 | depends on MMU | |
884 | depends on ARCH_HAS_DEBUG_VM_PGTABLE | |
885 | default y if DEBUG_VM | |
886 | help | |
887 | This option provides a debug method which can be used to test | |
888 | architecture page table helper functions on various platforms in | |
889 | verifying if they comply with expected generic MM semantics. This | |
890 | will help architecture code in making sure that any changes or | |
891 | new additions of these helpers still conform to expected | |
892 | semantics of the generic MM. Platforms will have to opt in for | |
893 | this through ARCH_HAS_DEBUG_VM_PGTABLE. | |
894 | ||
895 | If unsure, say N. | |
896 | ||
fa5b6ec9 LA |
897 | config ARCH_HAS_DEBUG_VIRTUAL |
898 | bool | |
899 | ||
0610c8a8 DH |
900 | config DEBUG_VIRTUAL |
901 | bool "Debug VM translations" | |
fa5b6ec9 | 902 | depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL |
0610c8a8 DH |
903 | help |
904 | Enable some costly sanity checks in virtual to page code. This can | |
905 | catch mistakes with virt_to_page() and friends. | |
906 | ||
907 | If unsure, say N. | |
908 | ||
909 | config DEBUG_NOMMU_REGIONS | |
910 | bool "Debug the global anon/private NOMMU mapping region tree" | |
911 | depends on DEBUG_KERNEL && !MMU | |
912 | help | |
913 | This option causes the global tree of anonymous and private mapping | |
914 | regions to be regularly checked for invalid topology. | |
915 | ||
916 | config DEBUG_MEMORY_INIT | |
917 | bool "Debug memory initialisation" if EXPERT | |
918 | default !EXPERT | |
919 | help | |
920 | Enable this for additional checks during memory initialisation. | |
921 | The sanity checks verify aspects of the VM such as the memory model | |
922 | and other information provided by the architecture. Verbose | |
923 | information will be printed at KERN_DEBUG loglevel depending | |
924 | on the mminit_loglevel= command-line option. | |
925 | ||
926 | If unsure, say Y | |
927 | ||
928 | config MEMORY_NOTIFIER_ERROR_INJECT | |
929 | tristate "Memory hotplug notifier error injection module" | |
50f9481e | 930 | depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION |
0610c8a8 DH |
931 | help |
932 | This option provides the ability to inject artificial errors to | |
933 | memory hotplug notifier chain callbacks. It is controlled through | |
934 | debugfs interface under /sys/kernel/debug/notifier-error-inject/memory | |
935 | ||
936 | If the notifier call chain should be failed with some events | |
937 | notified, write the error code to "actions/<notifier event>/error". | |
938 | ||
939 | Example: Inject memory hotplug offline error (-12 == -ENOMEM) | |
940 | ||
941 | # cd /sys/kernel/debug/notifier-error-inject/memory | |
942 | # echo -12 > actions/MEM_GOING_OFFLINE/error | |
943 | # echo offline > /sys/devices/system/memory/memoryXXX/state | |
944 | bash: echo: write error: Cannot allocate memory | |
945 | ||
946 | To compile this code as a module, choose M here: the module will | |
947 | be called memory-notifier-error-inject. | |
948 | ||
949 | If unsure, say N. | |
950 | ||
951 | config DEBUG_PER_CPU_MAPS | |
952 | bool "Debug access to per_cpu maps" | |
953 | depends on DEBUG_KERNEL | |
954 | depends on SMP | |
955 | help | |
956 | Say Y to verify that the per_cpu map being accessed has | |
957 | been set up. This adds a fair amount of code to kernel memory | |
958 | and decreases performance. | |
959 | ||
960 | Say N if unsure. | |
961 | ||
6e799cb6 TG |
962 | config DEBUG_KMAP_LOCAL |
963 | bool "Debug kmap_local temporary mappings" | |
964 | depends on DEBUG_KERNEL && KMAP_LOCAL | |
965 | help | |
966 | This option enables additional error checking for the kmap_local | |
967 | infrastructure. Disable for production use. | |
968 | ||
0e91a0c6 TG |
969 | config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
970 | bool | |
971 | ||
972 | config DEBUG_KMAP_LOCAL_FORCE_MAP | |
973 | bool "Enforce kmap_local temporary mappings" | |
974 | depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP | |
975 | select KMAP_LOCAL | |
976 | select DEBUG_KMAP_LOCAL | |
977 | help | |
978 | This option enforces temporary mappings through the kmap_local | |
979 | mechanism for non-highmem pages and on non-highmem systems. | |
980 | Disable this for production systems! | |
981 | ||
0610c8a8 DH |
982 | config DEBUG_HIGHMEM |
983 | bool "Highmem debugging" | |
984 | depends on DEBUG_KERNEL && HIGHMEM | |
0e91a0c6 | 985 | select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
6e799cb6 | 986 | select DEBUG_KMAP_LOCAL |
0610c8a8 | 987 | help |
b1357c9f GU |
988 | This option enables additional error checking for high memory |
989 | systems. Disable for production systems. | |
0610c8a8 DH |
990 | |
991 | config HAVE_DEBUG_STACKOVERFLOW | |
992 | bool | |
993 | ||
994 | config DEBUG_STACKOVERFLOW | |
995 | bool "Check for stack overflows" | |
996 | depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW | |
a7f7f624 | 997 | help |
0610c8a8 | 998 | Say Y here if you want to check for overflows of kernel, IRQ |
edb0ec07 | 999 | and exception stacks (if your architecture uses them). This |
0610c8a8 DH |
1000 | option will show detailed messages if free stack space drops |
1001 | below a certain limit. | |
1002 | ||
1003 | These kinds of bugs usually occur when call-chains in the | |
1004 | kernel get too deep, especially when interrupts are | |
1005 | involved. | |
1006 | ||
1007 | Use this in cases where you see apparently random memory | |
1008 | corruption, especially if it appears in 'struct thread_info' | |
1009 | ||
1010 | If in doubt, say "N". | |
1011 | ||
0b24becc | 1012 | source "lib/Kconfig.kasan" |
0ce20dd8 | 1013 | source "lib/Kconfig.kfence" |
f80be457 | 1014 | source "lib/Kconfig.kmsan" |
0b24becc | 1015 | |
0610c8a8 DH |
1016 | endmenu # "Memory Debugging" |
1017 | ||
a304e1b8 DW |
1018 | config DEBUG_SHIRQ |
1019 | bool "Debug shared IRQ handlers" | |
0244ad00 | 1020 | depends on DEBUG_KERNEL |
a304e1b8 | 1021 | help |
0a2fae2a WS |
1022 | Enable this to generate a spurious interrupt just before a shared |
1023 | interrupt handler is deregistered (generating one when registering | |
1024 | is currently disabled). Drivers need to handle this correctly. Some | |
1025 | don't and need to be caught. | |
a304e1b8 | 1026 | |
f43a289d CD |
1027 | menu "Debug Oops, Lockups and Hangs" |
1028 | ||
1029 | config PANIC_ON_OOPS | |
1030 | bool "Panic on Oops" | |
1031 | help | |
1032 | Say Y here to enable the kernel to panic when it oopses. This | |
1033 | has the same effect as setting oops=panic on the kernel command | |
1034 | line. | |
1035 | ||
1036 | This feature is useful to ensure that the kernel does not do | |
1037 | anything erroneous after an oops which could result in data | |
1038 | corruption or other issues. | |
1039 | ||
1040 | Say N if unsure. | |
1041 | ||
1042 | config PANIC_ON_OOPS_VALUE | |
1043 | int | |
1044 | range 0 1 | |
1045 | default 0 if !PANIC_ON_OOPS | |
1046 | default 1 if PANIC_ON_OOPS | |
1047 | ||
1048 | config PANIC_TIMEOUT | |
1049 | int "panic timeout" | |
1050 | default 0 | |
1051 | help | |
9d5b134f | 1052 | Set the timeout value (in seconds) until a reboot occurs when |
f43a289d CD |
1053 | the kernel panics. If n = 0, then we wait forever. A timeout |
1054 | value n > 0 will wait n seconds before rebooting, while a timeout | |
1055 | value n < 0 will reboot immediately. | |
92aef8fb | 1056 | |
58687acb | 1057 | config LOCKUP_DETECTOR |
05a4a952 NP |
1058 | bool |
1059 | ||
1060 | config SOFTLOCKUP_DETECTOR | |
1061 | bool "Detect Soft Lockups" | |
dea20a3f | 1062 | depends on DEBUG_KERNEL && !S390 |
05a4a952 | 1063 | select LOCKUP_DETECTOR |
8446f1d3 | 1064 | help |
58687acb | 1065 | Say Y here to enable the kernel to act as a watchdog to detect |
05a4a952 | 1066 | soft lockups. |
58687acb DZ |
1067 | |
1068 | Softlockups are bugs that cause the kernel to loop in kernel | |
5f329089 | 1069 | mode for more than 20 seconds, without giving other tasks a |
58687acb DZ |
1070 | chance to run. The current stack trace is displayed upon |
1071 | detection and the system will stay locked up. | |
8446f1d3 | 1072 | |
5f00ae0d RD |
1073 | config BOOTPARAM_SOFTLOCKUP_PANIC |
1074 | bool "Panic (Reboot) On Soft Lockups" | |
1075 | depends on SOFTLOCKUP_DETECTOR | |
1076 | help | |
1077 | Say Y here to enable the kernel to panic on "soft lockups", | |
1078 | which are bugs that cause the kernel to loop in kernel | |
1079 | mode for more than 20 seconds (configurable using the watchdog_thresh | |
1080 | sysctl), without giving other tasks a chance to run. | |
1081 | ||
1082 | The panic can be used in combination with panic_timeout, | |
1083 | to cause the system to reboot automatically after a | |
1084 | lockup has been detected. This feature is useful for | |
1085 | high-availability systems that have uptime guarantees and | |
1086 | where a lockup must be resolved ASAP. | |
1087 | ||
1088 | Say N if unsure. | |
1089 | ||
05a4a952 NP |
1090 | config HARDLOCKUP_DETECTOR_PERF |
1091 | bool | |
1092 | select SOFTLOCKUP_DETECTOR | |
1093 | ||
7edaeb68 TG |
1094 | # |
1095 | # Enables a timestamp based low pass filter to compensate for perf based | |
1096 | # hard lockup detection which runs too fast due to turbo modes. | |
1097 | # | |
1098 | config HARDLOCKUP_CHECK_TIMESTAMP | |
1099 | bool | |
1100 | ||
05a4a952 NP |
1101 | # |
1102 | # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard | |
1103 | # lockup detector rather than the perf based detector. | |
1104 | # | |
1105 | config HARDLOCKUP_DETECTOR | |
1106 | bool "Detect Hard Lockups" | |
1107 | depends on DEBUG_KERNEL && !S390 | |
1108 | depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH | |
1109 | select LOCKUP_DETECTOR | |
1110 | select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF | |
05a4a952 NP |
1111 | help |
1112 | Say Y here to enable the kernel to act as a watchdog to detect | |
1113 | hard lockups. | |
1114 | ||
58687acb | 1115 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
5f329089 | 1116 | for more than 10 seconds, without letting other interrupts have a |
58687acb DZ |
1117 | chance to run. The current stack trace is displayed upon detection |
1118 | and the system will stay locked up. | |
8446f1d3 | 1119 | |
fef2c9bc DZ |
1120 | config BOOTPARAM_HARDLOCKUP_PANIC |
1121 | bool "Panic (Reboot) On Hard Lockups" | |
8f1f66ed | 1122 | depends on HARDLOCKUP_DETECTOR |
fef2c9bc DZ |
1123 | help |
1124 | Say Y here to enable the kernel to panic on "hard lockups", | |
1125 | which are bugs that cause the kernel to loop in kernel | |
5f329089 FLVC |
1126 | mode with interrupts disabled for more than 10 seconds (configurable |
1127 | using the watchdog_thresh sysctl). | |
fef2c9bc DZ |
1128 | |
1129 | Say N if unsure. | |
1130 | ||
e162b39a MSB |
1131 | config DETECT_HUNG_TASK |
1132 | bool "Detect Hung Tasks" | |
1133 | depends on DEBUG_KERNEL | |
05a4a952 | 1134 | default SOFTLOCKUP_DETECTOR |
e162b39a | 1135 | help |
0610c8a8 DH |
1136 | Say Y here to enable the kernel to detect "hung tasks", |
1137 | which are bugs that cause the task to be stuck in | |
96b03ab8 | 1138 | uninterruptible "D" state indefinitely. |
1da177e4 | 1139 | |
0610c8a8 DH |
1140 | When a hung task is detected, the kernel will print the |
1141 | current stack trace (which you should report), but the | |
1142 | task will stay in uninterruptible state. If lockdep is | |
1143 | enabled then all held locks will also be reported. This | |
1144 | feature has negligible overhead. | |
871751e2 | 1145 | |
0610c8a8 DH |
1146 | config DEFAULT_HUNG_TASK_TIMEOUT |
1147 | int "Default timeout for hung task detection (in seconds)" | |
1148 | depends on DETECT_HUNG_TASK | |
1149 | default 120 | |
f0630fff | 1150 | help |
0610c8a8 DH |
1151 | This option controls the default timeout (in seconds) used |
1152 | to determine when a task has become non-responsive and should | |
1153 | be considered hung. | |
f0630fff | 1154 | |
0610c8a8 DH |
1155 | It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
1156 | sysctl or by writing a value to | |
1157 | /proc/sys/kernel/hung_task_timeout_secs. | |
8ff12cfc | 1158 | |
0610c8a8 DH |
1159 | A timeout of 0 disables the check. The default is two minutes. |
1160 | Keeping the default should be fine in most cases. | |
b69ec42b | 1161 | |
0610c8a8 DH |
1162 | config BOOTPARAM_HUNG_TASK_PANIC |
1163 | bool "Panic (Reboot) On Hung Tasks" | |
1164 | depends on DETECT_HUNG_TASK | |
3bba00d7 | 1165 | help |
0610c8a8 DH |
1166 | Say Y here to enable the kernel to panic on "hung tasks", |
1167 | which are bugs that cause the kernel to leave a task stuck | |
1168 | in uninterruptible "D" state. | |
3bba00d7 | 1169 | |
0610c8a8 DH |
1170 | The panic can be used in combination with panic_timeout, |
1171 | to cause the system to reboot automatically after a | |
1172 | hung task has been detected. This feature is useful for | |
1173 | high-availability systems that have uptime guarantees and | |
1174 | where a hung tasks must be resolved ASAP. | |
bf96d1e3 | 1175 | |
0610c8a8 | 1176 | Say N if unsure. |
bf96d1e3 | 1177 | |
82607adc TH |
1178 | config WQ_WATCHDOG |
1179 | bool "Detect Workqueue Stalls" | |
1180 | depends on DEBUG_KERNEL | |
1181 | help | |
1182 | Say Y here to enable stall detection on workqueues. If a | |
1183 | worker pool doesn't make forward progress on a pending work | |
1184 | item for over a given amount of time, 30s by default, a | |
1185 | warning message is printed along with dump of workqueue | |
1186 | state. This can be configured through kernel parameter | |
1187 | "workqueue.watchdog_thresh" and its sysfs counterpart. | |
1188 | ||
30428ef5 KK |
1189 | config TEST_LOCKUP |
1190 | tristate "Test module to generate lockups" | |
63646bc9 | 1191 | depends on m |
30428ef5 KK |
1192 | help |
1193 | This builds the "test_lockup" module that helps to make sure | |
1194 | that watchdogs and lockup detectors are working properly. | |
1195 | ||
1196 | Depending on module parameters it could emulate soft or hard | |
1197 | lockup, "hung task", or locking arbitrary lock for a long time. | |
1198 | Also it could generate series of lockups with cooling-down periods. | |
1199 | ||
1200 | If unsure, say N. | |
1201 | ||
92aef8fb DH |
1202 | endmenu # "Debug lockups and hangs" |
1203 | ||
ebebdd09 | 1204 | menu "Scheduler Debugging" |
5800dc3c | 1205 | |
0610c8a8 DH |
1206 | config SCHED_DEBUG |
1207 | bool "Collect scheduler debugging info" | |
1208 | depends on DEBUG_KERNEL && PROC_FS | |
1209 | default y | |
0822ee4a | 1210 | help |
0610c8a8 DH |
1211 | If you say Y here, the /proc/sched_debug file will be provided |
1212 | that can help debug the scheduler. The runtime overhead of this | |
1213 | option is minimal. | |
0822ee4a | 1214 | |
f6db8347 NR |
1215 | config SCHED_INFO |
1216 | bool | |
1217 | default n | |
1218 | ||
0610c8a8 DH |
1219 | config SCHEDSTATS |
1220 | bool "Collect scheduler statistics" | |
1221 | depends on DEBUG_KERNEL && PROC_FS | |
f6db8347 | 1222 | select SCHED_INFO |
0610c8a8 DH |
1223 | help |
1224 | If you say Y here, additional code will be inserted into the | |
1225 | scheduler and related routines to collect statistics about | |
1226 | scheduler behavior and provide them in /proc/schedstat. These | |
1227 | stats may be useful for both tuning and debugging the scheduler | |
1228 | If you aren't debugging the scheduler or trying to tune a specific | |
1229 | application, you can say N to avoid the very slight overhead | |
1230 | this adds. | |
0822ee4a | 1231 | |
ebebdd09 | 1232 | endmenu |
0d9e2632 | 1233 | |
3c17ad19 JS |
1234 | config DEBUG_TIMEKEEPING |
1235 | bool "Enable extra timekeeping sanity checking" | |
1236 | help | |
1237 | This option will enable additional timekeeping sanity checks | |
1238 | which may be helpful when diagnosing issues where timekeeping | |
1239 | problems are suspected. | |
1240 | ||
1241 | This may include checks in the timekeeping hotpaths, so this | |
1242 | option may have a (very small) performance impact to some | |
1243 | workloads. | |
1244 | ||
1245 | If unsure, say N. | |
1246 | ||
1da177e4 LT |
1247 | config DEBUG_PREEMPT |
1248 | bool "Debug preemptible kernel" | |
9f472869 | 1249 | depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT |
1da177e4 LT |
1250 | default y |
1251 | help | |
1252 | If you say Y here then the kernel will use a debug variant of the | |
1253 | commonly used smp_processor_id() function and will print warnings | |
1254 | if kernel code uses it in a preemption-unsafe way. Also, the kernel | |
1255 | will detect preemption count underflows. | |
1256 | ||
9eade16b DH |
1257 | menu "Lock Debugging (spinlocks, mutexes, etc...)" |
1258 | ||
f07cbebb WL |
1259 | config LOCK_DEBUGGING_SUPPORT |
1260 | bool | |
1261 | depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT | |
1262 | default y | |
1263 | ||
19193bca WL |
1264 | config PROVE_LOCKING |
1265 | bool "Lock debugging: prove locking correctness" | |
1266 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT | |
1267 | select LOCKDEP | |
1268 | select DEBUG_SPINLOCK | |
bb630f9f | 1269 | select DEBUG_MUTEXES if !PREEMPT_RT |
19193bca | 1270 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
c71fd893 | 1271 | select DEBUG_RWSEMS |
19193bca WL |
1272 | select DEBUG_WW_MUTEX_SLOWPATH |
1273 | select DEBUG_LOCK_ALLOC | |
8fd8ad5c | 1274 | select PREEMPT_COUNT if !ARCH_NO_PREEMPT |
19193bca WL |
1275 | select TRACE_IRQFLAGS |
1276 | default n | |
1277 | help | |
1278 | This feature enables the kernel to prove that all locking | |
1279 | that occurs in the kernel runtime is mathematically | |
1280 | correct: that under no circumstance could an arbitrary (and | |
1281 | not yet triggered) combination of observed locking | |
1282 | sequences (on an arbitrary number of CPUs, running an | |
1283 | arbitrary number of tasks and interrupt contexts) cause a | |
1284 | deadlock. | |
1285 | ||
1286 | In short, this feature enables the kernel to report locking | |
1287 | related deadlocks before they actually occur. | |
1288 | ||
1289 | The proof does not depend on how hard and complex a | |
1290 | deadlock scenario would be to trigger: how many | |
1291 | participant CPUs, tasks and irq-contexts would be needed | |
1292 | for it to trigger. The proof also does not depend on | |
1293 | timing: if a race and a resulting deadlock is possible | |
1294 | theoretically (no matter how unlikely the race scenario | |
1295 | is), it will be proven so and will immediately be | |
1296 | reported by the kernel (once the event is observed that | |
1297 | makes the deadlock theoretically possible). | |
1298 | ||
1299 | If a deadlock is impossible (i.e. the locking rules, as | |
1300 | observed by the kernel, are mathematically correct), the | |
1301 | kernel reports nothing. | |
1302 | ||
1303 | NOTE: this feature can also be enabled for rwlocks, mutexes | |
1304 | and rwsems - in which case all dependencies between these | |
1305 | different locking variants are observed and mapped too, and | |
1306 | the proof of observed correctness is also maintained for an | |
1307 | arbitrary combination of these separate locking variants. | |
1308 | ||
387b1468 | 1309 | For more details, see Documentation/locking/lockdep-design.rst. |
19193bca | 1310 | |
de8f5e4f PZ |
1311 | config PROVE_RAW_LOCK_NESTING |
1312 | bool "Enable raw_spinlock - spinlock nesting checks" | |
1313 | depends on PROVE_LOCKING | |
1314 | default n | |
1315 | help | |
1316 | Enable the raw_spinlock vs. spinlock nesting checks which ensure | |
1317 | that the lock nesting rules for PREEMPT_RT enabled kernels are | |
1318 | not violated. | |
1319 | ||
1320 | NOTE: There are known nesting problems. So if you enable this | |
1321 | option expect lockdep splats until these problems have been fully | |
1322 | addressed which is work in progress. This config switch allows to | |
1323 | identify and analyze these problems. It will be removed and the | |
9dbbc3b9 | 1324 | check permanently enabled once the main issues have been fixed. |
de8f5e4f PZ |
1325 | |
1326 | If unsure, select N. | |
1327 | ||
19193bca WL |
1328 | config LOCK_STAT |
1329 | bool "Lock usage statistics" | |
1330 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT | |
1331 | select LOCKDEP | |
1332 | select DEBUG_SPINLOCK | |
bb630f9f | 1333 | select DEBUG_MUTEXES if !PREEMPT_RT |
19193bca WL |
1334 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
1335 | select DEBUG_LOCK_ALLOC | |
1336 | default n | |
1337 | help | |
1338 | This feature enables tracking lock contention points | |
1339 | ||
387b1468 | 1340 | For more details, see Documentation/locking/lockstat.rst |
19193bca WL |
1341 | |
1342 | This also enables lock events required by "perf lock", | |
1343 | subcommand of perf. | |
1344 | If you want to use "perf lock", you also need to turn on | |
1345 | CONFIG_EVENT_TRACING. | |
1346 | ||
1347 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. | |
1348 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) | |
1349 | ||
e7eebaf6 IM |
1350 | config DEBUG_RT_MUTEXES |
1351 | bool "RT Mutex debugging, deadlock detection" | |
e7eebaf6 IM |
1352 | depends on DEBUG_KERNEL && RT_MUTEXES |
1353 | help | |
1354 | This allows rt mutex semantics violations and rt mutex related | |
1355 | deadlocks (lockups) to be detected and reported automatically. | |
1356 | ||
1da177e4 | 1357 | config DEBUG_SPINLOCK |
4d9f34ad | 1358 | bool "Spinlock and rw-lock debugging: basic checks" |
1da177e4 | 1359 | depends on DEBUG_KERNEL |
e335e3eb | 1360 | select UNINLINE_SPIN_UNLOCK |
1da177e4 LT |
1361 | help |
1362 | Say Y here and build SMP to catch missing spinlock initialization | |
1363 | and certain other kinds of spinlock errors commonly made. This is | |
1364 | best used in conjunction with the NMI watchdog so that spinlock | |
1365 | deadlocks are also debuggable. | |
1366 | ||
4d9f34ad IM |
1367 | config DEBUG_MUTEXES |
1368 | bool "Mutex debugging: basic checks" | |
bb630f9f | 1369 | depends on DEBUG_KERNEL && !PREEMPT_RT |
4d9f34ad IM |
1370 | help |
1371 | This feature allows mutex semantics violations to be detected and | |
1372 | reported. | |
1373 | ||
23010027 DV |
1374 | config DEBUG_WW_MUTEX_SLOWPATH |
1375 | bool "Wait/wound mutex debugging: Slowpath testing" | |
f07cbebb | 1376 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
23010027 DV |
1377 | select DEBUG_LOCK_ALLOC |
1378 | select DEBUG_SPINLOCK | |
bb630f9f TG |
1379 | select DEBUG_MUTEXES if !PREEMPT_RT |
1380 | select DEBUG_RT_MUTEXES if PREEMPT_RT | |
23010027 DV |
1381 | help |
1382 | This feature enables slowpath testing for w/w mutex users by | |
1383 | injecting additional -EDEADLK wound/backoff cases. Together with | |
1384 | the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this | |
1385 | will test all possible w/w mutex interface abuse with the | |
1386 | exception of simply not acquiring all the required locks. | |
4d692373 RC |
1387 | Note that this feature can introduce significant overhead, so |
1388 | it really should not be enabled in a production or distro kernel, | |
1389 | even a debug kernel. If you are a driver writer, enable it. If | |
1390 | you are a distro, do not. | |
23010027 | 1391 | |
5149cbac WL |
1392 | config DEBUG_RWSEMS |
1393 | bool "RW Semaphore debugging: basic checks" | |
c71fd893 | 1394 | depends on DEBUG_KERNEL |
5149cbac | 1395 | help |
c71fd893 WL |
1396 | This debugging feature allows mismatched rw semaphore locks |
1397 | and unlocks to be detected and reported. | |
5149cbac | 1398 | |
4d9f34ad IM |
1399 | config DEBUG_LOCK_ALLOC |
1400 | bool "Lock debugging: detect incorrect freeing of live locks" | |
f07cbebb | 1401 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
4d9f34ad | 1402 | select DEBUG_SPINLOCK |
bb630f9f | 1403 | select DEBUG_MUTEXES if !PREEMPT_RT |
f5694788 | 1404 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
4d9f34ad IM |
1405 | select LOCKDEP |
1406 | help | |
1407 | This feature will check whether any held lock (spinlock, rwlock, | |
1408 | mutex or rwsem) is incorrectly freed by the kernel, via any of the | |
1409 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), | |
1410 | vfree(), etc.), whether a live lock is incorrectly reinitialized via | |
1411 | spin_lock_init()/mutex_init()/etc., or whether there is any lock | |
1412 | held during task exit. | |
1413 | ||
4d9f34ad IM |
1414 | config LOCKDEP |
1415 | bool | |
f07cbebb | 1416 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
4d9f34ad | 1417 | select STACKTRACE |
4d9f34ad IM |
1418 | select KALLSYMS |
1419 | select KALLSYMS_ALL | |
1420 | ||
395102db DJ |
1421 | config LOCKDEP_SMALL |
1422 | bool | |
1423 | ||
5dc33592 TH |
1424 | config LOCKDEP_BITS |
1425 | int "Bitsize for MAX_LOCKDEP_ENTRIES" | |
1426 | depends on LOCKDEP && !LOCKDEP_SMALL | |
1427 | range 10 30 | |
1428 | default 15 | |
1429 | help | |
1430 | Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message. | |
1431 | ||
1432 | config LOCKDEP_CHAINS_BITS | |
1433 | int "Bitsize for MAX_LOCKDEP_CHAINS" | |
1434 | depends on LOCKDEP && !LOCKDEP_SMALL | |
1435 | range 10 30 | |
1436 | default 16 | |
1437 | help | |
1438 | Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message. | |
1439 | ||
1440 | config LOCKDEP_STACK_TRACE_BITS | |
1441 | int "Bitsize for MAX_STACK_TRACE_ENTRIES" | |
1442 | depends on LOCKDEP && !LOCKDEP_SMALL | |
1443 | range 10 30 | |
1444 | default 19 | |
1445 | help | |
1446 | Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message. | |
1447 | ||
1448 | config LOCKDEP_STACK_TRACE_HASH_BITS | |
1449 | int "Bitsize for STACK_TRACE_HASH_SIZE" | |
1450 | depends on LOCKDEP && !LOCKDEP_SMALL | |
1451 | range 10 30 | |
1452 | default 14 | |
1453 | help | |
1454 | Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES. | |
1455 | ||
1456 | config LOCKDEP_CIRCULAR_QUEUE_BITS | |
1457 | int "Bitsize for elements in circular_queue struct" | |
1458 | depends on LOCKDEP | |
1459 | range 10 30 | |
1460 | default 12 | |
1461 | help | |
1462 | Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure. | |
1463 | ||
4d9f34ad IM |
1464 | config DEBUG_LOCKDEP |
1465 | bool "Lock dependency engine debugging" | |
517e7aa5 | 1466 | depends on DEBUG_KERNEL && LOCKDEP |
997acaf6 | 1467 | select DEBUG_IRQFLAGS |
4d9f34ad IM |
1468 | help |
1469 | If you say Y here, the lock dependency engine will do | |
1470 | additional runtime checks to debug itself, at the price | |
1471 | of more runtime overhead. | |
1472 | ||
d902db1e FW |
1473 | config DEBUG_ATOMIC_SLEEP |
1474 | bool "Sleep inside atomic section checking" | |
e8f7c70f | 1475 | select PREEMPT_COUNT |
1da177e4 | 1476 | depends on DEBUG_KERNEL |
87a4c375 | 1477 | depends on !ARCH_NO_PREEMPT |
1da177e4 LT |
1478 | help |
1479 | If you say Y here, various routines which may sleep will become very | |
d902db1e FW |
1480 | noisy if they are called inside atomic sections: when a spinlock is |
1481 | held, inside an rcu read side critical section, inside preempt disabled | |
1482 | sections, inside an interrupt, etc... | |
1da177e4 | 1483 | |
cae2ed9a IM |
1484 | config DEBUG_LOCKING_API_SELFTESTS |
1485 | bool "Locking API boot-time self-tests" | |
1486 | depends on DEBUG_KERNEL | |
1487 | help | |
1488 | Say Y here if you want the kernel to run a short self-test during | |
1489 | bootup. The self-test checks whether common types of locking bugs | |
1490 | are detected by debugging mechanisms or not. (if you disable | |
9dbbc3b9 | 1491 | lock debugging then those bugs won't be detected of course.) |
cae2ed9a IM |
1492 | The following locking APIs are covered: spinlocks, rwlocks, |
1493 | mutexes and rwsems. | |
1494 | ||
0af3fe1e PM |
1495 | config LOCK_TORTURE_TEST |
1496 | tristate "torture tests for locking" | |
1497 | depends on DEBUG_KERNEL | |
1498 | select TORTURE_TEST | |
0af3fe1e PM |
1499 | help |
1500 | This option provides a kernel module that runs torture tests | |
1501 | on kernel locking primitives. The kernel module may be built | |
1502 | after the fact on the running kernel to be tested, if desired. | |
1503 | ||
1504 | Say Y here if you want kernel locking-primitive torture tests | |
1505 | to be built into the kernel. | |
1506 | Say M if you want these torture tests to build as a module. | |
1507 | Say N if you are unsure. | |
1508 | ||
f2a5fec1 CW |
1509 | config WW_MUTEX_SELFTEST |
1510 | tristate "Wait/wound mutex selftests" | |
1511 | help | |
1512 | This option provides a kernel module that runs tests on the | |
1513 | on the struct ww_mutex locking API. | |
1514 | ||
1515 | It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction | |
1516 | with this test harness. | |
1517 | ||
1518 | Say M if you want these self tests to build as a module. | |
1519 | Say N if you are unsure. | |
1520 | ||
e9d338a0 PM |
1521 | config SCF_TORTURE_TEST |
1522 | tristate "torture tests for smp_call_function*()" | |
1523 | depends on DEBUG_KERNEL | |
1524 | select TORTURE_TEST | |
1525 | help | |
1526 | This option provides a kernel module that runs torture tests | |
1527 | on the smp_call_function() family of primitives. The kernel | |
1528 | module may be built after the fact on the running kernel to | |
1529 | be tested, if desired. | |
1530 | ||
35feb604 PM |
1531 | config CSD_LOCK_WAIT_DEBUG |
1532 | bool "Debugging for csd_lock_wait(), called from smp_call_function*()" | |
1533 | depends on DEBUG_KERNEL | |
1534 | depends on 64BIT | |
1535 | default n | |
1536 | help | |
1537 | This option enables debug prints when CPUs are slow to respond | |
1538 | to the smp_call_function*() IPI wrappers. These debug prints | |
1539 | include the IPI handler function currently executing (if any) | |
1540 | and relevant stack traces. | |
1541 | ||
9eade16b | 1542 | endmenu # lock debugging |
8637c099 | 1543 | |
9eade16b | 1544 | config TRACE_IRQFLAGS |
ed004953 | 1545 | depends on TRACE_IRQFLAGS_SUPPORT |
9eade16b | 1546 | bool |
5ca43f6c | 1547 | help |
9eade16b DH |
1548 | Enables hooks to interrupt enabling and disabling for |
1549 | either tracing or lock debugging. | |
5ca43f6c | 1550 | |
ed004953 | 1551 | config TRACE_IRQFLAGS_NMI |
1552 | def_bool y | |
1553 | depends on TRACE_IRQFLAGS | |
1554 | depends on TRACE_IRQFLAGS_NMI_SUPPORT | |
1555 | ||
997acaf6 MR |
1556 | config DEBUG_IRQFLAGS |
1557 | bool "Debug IRQ flag manipulation" | |
1558 | help | |
1559 | Enables checks for potentially unsafe enabling or disabling of | |
1560 | interrupts, such as calling raw_local_irq_restore() when interrupts | |
1561 | are enabled. | |
1562 | ||
8637c099 | 1563 | config STACKTRACE |
0c38e1fe | 1564 | bool "Stack backtrace support" |
8637c099 | 1565 | depends on STACKTRACE_SUPPORT |
0c38e1fe DJ |
1566 | help |
1567 | This option causes the kernel to create a /proc/pid/stack for | |
1568 | every process, showing its current stack trace. | |
1569 | It is also used by various kernel debugging features that require | |
1570 | stack trace generation. | |
5ca43f6c | 1571 | |
eecabf56 TT |
1572 | config WARN_ALL_UNSEEDED_RANDOM |
1573 | bool "Warn for all uses of unseeded randomness" | |
1574 | default n | |
d06bfd19 JD |
1575 | help |
1576 | Some parts of the kernel contain bugs relating to their use of | |
1577 | cryptographically secure random numbers before it's actually possible | |
1578 | to generate those numbers securely. This setting ensures that these | |
1579 | flaws don't go unnoticed, by enabling a message, should this ever | |
1580 | occur. This will allow people with obscure setups to know when things | |
1581 | are going wrong, so that they might contact developers about fixing | |
1582 | it. | |
1583 | ||
eecabf56 TT |
1584 | Unfortunately, on some models of some architectures getting |
1585 | a fully seeded CRNG is extremely difficult, and so this can | |
1586 | result in dmesg getting spammed for a surprisingly long | |
1587 | time. This is really bad from a security perspective, and | |
1588 | so architecture maintainers really need to do what they can | |
1589 | to get the CRNG seeded sooner after the system is booted. | |
4c5d114e | 1590 | However, since users cannot do anything actionable to |
cc1e127b | 1591 | address this, by default this option is disabled. |
eecabf56 TT |
1592 | |
1593 | Say Y here if you want to receive warnings for all uses of | |
1594 | unseeded randomness. This will be of use primarily for | |
4c5d114e | 1595 | those developers interested in improving the security of |
eecabf56 TT |
1596 | Linux kernels running on their architecture (or |
1597 | subarchitecture). | |
d06bfd19 | 1598 | |
1da177e4 LT |
1599 | config DEBUG_KOBJECT |
1600 | bool "kobject debugging" | |
1601 | depends on DEBUG_KERNEL | |
1602 | help | |
1603 | If you say Y here, some extra kobject debugging messages will be sent | |
aca52c39 | 1604 | to the syslog. |
1da177e4 | 1605 | |
c817a67e RK |
1606 | config DEBUG_KOBJECT_RELEASE |
1607 | bool "kobject release debugging" | |
2a999aa0 | 1608 | depends on DEBUG_OBJECTS_TIMERS |
c817a67e RK |
1609 | help |
1610 | kobjects are reference counted objects. This means that their | |
1611 | last reference count put is not predictable, and the kobject can | |
b6c69474 | 1612 | live on past the point at which a driver decides to drop its |
c817a67e RK |
1613 | initial reference to the kobject gained on allocation. An |
1614 | example of this would be a struct device which has just been | |
1615 | unregistered. | |
1616 | ||
1617 | However, some buggy drivers assume that after such an operation, | |
1618 | the memory backing the kobject can be immediately freed. This | |
1619 | goes completely against the principles of a refcounted object. | |
1620 | ||
1621 | If you say Y here, the kernel will delay the release of kobjects | |
1622 | on the last reference count to improve the visibility of this | |
1623 | kind of kobject release bug. | |
1624 | ||
9b2a60c4 CM |
1625 | config HAVE_DEBUG_BUGVERBOSE |
1626 | bool | |
1627 | ||
3be5cbcd | 1628 | menu "Debug kernel data structures" |
1da177e4 | 1629 | |
199a9afc DJ |
1630 | config DEBUG_LIST |
1631 | bool "Debug linked list manipulation" | |
4520bcb2 | 1632 | depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION |
199a9afc DJ |
1633 | help |
1634 | Enable this to turn on extended checks in the linked-list | |
1635 | walking routines. | |
1636 | ||
1637 | If unsure, say N. | |
1638 | ||
8e18faea | 1639 | config DEBUG_PLIST |
b8cfff68 DS |
1640 | bool "Debug priority linked list manipulation" |
1641 | depends on DEBUG_KERNEL | |
1642 | help | |
1643 | Enable this to turn on extended checks in the priority-ordered | |
1644 | linked-list (plist) walking routines. This checks the entire | |
1645 | list multiple times during each manipulation. | |
1646 | ||
1647 | If unsure, say N. | |
1648 | ||
d6ec0842 JA |
1649 | config DEBUG_SG |
1650 | bool "Debug SG table operations" | |
1651 | depends on DEBUG_KERNEL | |
1652 | help | |
1653 | Enable this to turn on checks on scatter-gather tables. This can | |
1654 | help find problems with drivers that do not properly initialize | |
1655 | their sg tables. | |
1656 | ||
1657 | If unsure, say N. | |
1658 | ||
1b2439db AV |
1659 | config DEBUG_NOTIFIERS |
1660 | bool "Debug notifier call chains" | |
1661 | depends on DEBUG_KERNEL | |
1662 | help | |
1663 | Enable this to turn on sanity checking for notifier call chains. | |
1664 | This is most useful for kernel developers to make sure that | |
1665 | modules properly unregister themselves from notifier chains. | |
1666 | This is a relatively cheap check but if you care about maximum | |
1667 | performance, say N. | |
1668 | ||
3be5cbcd CD |
1669 | config BUG_ON_DATA_CORRUPTION |
1670 | bool "Trigger a BUG when data corruption is detected" | |
1671 | select DEBUG_LIST | |
1672 | help | |
1673 | Select this option if the kernel should BUG when it encounters | |
1674 | data corruption in kernel memory structures when they get checked | |
1675 | for validity. | |
1676 | ||
1677 | If unsure, say N. | |
1678 | ||
54a611b6 LH |
1679 | config DEBUG_MAPLE_TREE |
1680 | bool "Debug maple trees" | |
1681 | depends on DEBUG_KERNEL | |
1682 | help | |
1683 | Enable maple tree debugging information and extra validations. | |
1684 | ||
1685 | If unsure, say N. | |
1686 | ||
3be5cbcd CD |
1687 | endmenu |
1688 | ||
e0e81739 DH |
1689 | config DEBUG_CREDENTIALS |
1690 | bool "Debug credential management" | |
1691 | depends on DEBUG_KERNEL | |
1692 | help | |
1693 | Enable this to turn on some debug checking for credential | |
1694 | management. The additional code keeps track of the number of | |
1695 | pointers from task_structs to any given cred struct, and checks to | |
1696 | see that this number never exceeds the usage count of the cred | |
1697 | struct. | |
1698 | ||
1699 | Furthermore, if SELinux is enabled, this also checks that the | |
1700 | security pointer in the cred struct is never seen to be invalid. | |
1701 | ||
1702 | If unsure, say N. | |
1703 | ||
43a0a2a7 | 1704 | source "kernel/rcu/Kconfig.debug" |
2f03e3ca | 1705 | |
f303fccb TH |
1706 | config DEBUG_WQ_FORCE_RR_CPU |
1707 | bool "Force round-robin CPU selection for unbound work items" | |
1708 | depends on DEBUG_KERNEL | |
1709 | default n | |
1710 | help | |
1711 | Workqueue used to implicitly guarantee that work items queued | |
1712 | without explicit CPU specified are put on the local CPU. This | |
1713 | guarantee is no longer true and while local CPU is still | |
1714 | preferred work items may be put on foreign CPUs. Kernel | |
1715 | parameter "workqueue.debug_force_rr_cpu" is added to force | |
1716 | round-robin CPU selection to flush out usages which depend on the | |
1717 | now broken guarantee. This config option enables the debug | |
1718 | feature by default. When enabled, memory and cache locality will | |
1719 | be impacted. | |
1720 | ||
757c989b TG |
1721 | config CPU_HOTPLUG_STATE_CONTROL |
1722 | bool "Enable CPU hotplug state control" | |
1723 | depends on DEBUG_KERNEL | |
1724 | depends on HOTPLUG_CPU | |
1725 | default n | |
1726 | help | |
1727 | Allows to write steps between "offline" and "online" to the CPUs | |
1728 | sysfs target file so states can be stepped granular. This is a debug | |
1729 | option for now as the hotplug machinery cannot be stopped and | |
1730 | restarted at arbitrary points yet. | |
1731 | ||
1732 | Say N if your are unsure. | |
1733 | ||
09a74952 CD |
1734 | config LATENCYTOP |
1735 | bool "Latency measuring infrastructure" | |
1736 | depends on DEBUG_KERNEL | |
1737 | depends on STACKTRACE_SUPPORT | |
1738 | depends on PROC_FS | |
7d37cb2c | 1739 | depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86 |
09a74952 CD |
1740 | select KALLSYMS |
1741 | select KALLSYMS_ALL | |
1742 | select STACKTRACE | |
1743 | select SCHEDSTATS | |
09a74952 CD |
1744 | help |
1745 | Enable this option if you want to use the LatencyTOP tool | |
1746 | to find out which userspace is blocking on what kernel operations. | |
1747 | ||
6ab42860 TH |
1748 | config DEBUG_CGROUP_REF |
1749 | bool "Disable inlining of cgroup css reference count functions" | |
1750 | depends on DEBUG_KERNEL | |
1751 | depends on CGROUPS | |
1752 | depends on KPROBES | |
1753 | default n | |
1754 | help | |
1755 | Force cgroup css reference count functions to not be inlined so | |
1756 | that they can be kprobed for debugging. | |
1757 | ||
09a74952 CD |
1758 | source "kernel/trace/Kconfig" |
1759 | ||
1760 | config PROVIDE_OHCI1394_DMA_INIT | |
1761 | bool "Remote debugging over FireWire early on boot" | |
1762 | depends on PCI && X86 | |
1763 | help | |
1764 | If you want to debug problems which hang or crash the kernel early | |
1765 | on boot and the crashing machine has a FireWire port, you can use | |
1766 | this feature to remotely access the memory of the crashed machine | |
1767 | over FireWire. This employs remote DMA as part of the OHCI1394 | |
1768 | specification which is now the standard for FireWire controllers. | |
1769 | ||
1770 | With remote DMA, you can monitor the printk buffer remotely using | |
1771 | firescope and access all memory below 4GB using fireproxy from gdb. | |
1772 | Even controlling a kernel debugger is possible using remote DMA. | |
1773 | ||
1774 | Usage: | |
1775 | ||
1776 | If ohci1394_dma=early is used as boot parameter, it will initialize | |
1777 | all OHCI1394 controllers which are found in the PCI config space. | |
1778 | ||
1779 | As all changes to the FireWire bus such as enabling and disabling | |
1780 | devices cause a bus reset and thereby disable remote DMA for all | |
1781 | devices, be sure to have the cable plugged and FireWire enabled on | |
1782 | the debugging host before booting the debug target for debugging. | |
1783 | ||
1784 | This code (~1k) is freed after boot. By then, the firewire stack | |
1785 | in charge of the OHCI-1394 controllers should be used instead. | |
1786 | ||
a74e2a22 | 1787 | See Documentation/core-api/debugging-via-ohci1394.rst for more information. |
09a74952 | 1788 | |
045f6d79 CD |
1789 | source "samples/Kconfig" |
1790 | ||
1791 | config ARCH_HAS_DEVMEM_IS_ALLOWED | |
1792 | bool | |
1793 | ||
1794 | config STRICT_DEVMEM | |
1795 | bool "Filter access to /dev/mem" | |
1796 | depends on MMU && DEVMEM | |
527701ed | 1797 | depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED |
045f6d79 CD |
1798 | default y if PPC || X86 || ARM64 |
1799 | help | |
1800 | If this option is disabled, you allow userspace (root) access to all | |
1801 | of memory, including kernel and userspace memory. Accidental | |
1802 | access to this is obviously disastrous, but specific access can | |
1803 | be used by people debugging the kernel. Note that with PAT support | |
1804 | enabled, even in this case there are restrictions on /dev/mem | |
1805 | use due to the cache aliasing requirements. | |
1806 | ||
1807 | If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem | |
1808 | file only allows userspace access to PCI space and the BIOS code and | |
1809 | data regions. This is sufficient for dosemu and X and all common | |
1810 | users of /dev/mem. | |
1811 | ||
1812 | If in doubt, say Y. | |
1813 | ||
1814 | config IO_STRICT_DEVMEM | |
1815 | bool "Filter I/O access to /dev/mem" | |
1816 | depends on STRICT_DEVMEM | |
1817 | help | |
1818 | If this option is disabled, you allow userspace (root) access to all | |
1819 | io-memory regardless of whether a driver is actively using that | |
1820 | range. Accidental access to this is obviously disastrous, but | |
1821 | specific access can be used by people debugging kernel drivers. | |
1822 | ||
1823 | If this option is switched on, the /dev/mem file only allows | |
1824 | userspace access to *idle* io-memory ranges (see /proc/iomem) This | |
1825 | may break traditional users of /dev/mem (dosemu, legacy X, etc...) | |
1826 | if the driver using a given range cannot be disabled. | |
1827 | ||
1828 | If in doubt, say Y. | |
1829 | ||
1830 | menu "$(SRCARCH) Debugging" | |
1831 | ||
1832 | source "arch/$(SRCARCH)/Kconfig.debug" | |
1833 | ||
1834 | endmenu | |
1835 | ||
1836 | menu "Kernel Testing and Coverage" | |
1837 | ||
09a74952 CD |
1838 | source "lib/kunit/Kconfig" |
1839 | ||
8d438288 AM |
1840 | config NOTIFIER_ERROR_INJECTION |
1841 | tristate "Notifier error injection" | |
1842 | depends on DEBUG_KERNEL | |
1843 | select DEBUG_FS | |
1844 | help | |
e41e85cc | 1845 | This option provides the ability to inject artificial errors to |
8d438288 AM |
1846 | specified notifier chain callbacks. It is useful to test the error |
1847 | handling of notifier call chain failures. | |
1848 | ||
1849 | Say N if unsure. | |
1850 | ||
048b9c35 AM |
1851 | config PM_NOTIFIER_ERROR_INJECT |
1852 | tristate "PM notifier error injection module" | |
1853 | depends on PM && NOTIFIER_ERROR_INJECTION | |
1854 | default m if PM_DEBUG | |
1855 | help | |
e41e85cc | 1856 | This option provides the ability to inject artificial errors to |
048b9c35 AM |
1857 | PM notifier chain callbacks. It is controlled through debugfs |
1858 | interface /sys/kernel/debug/notifier-error-inject/pm | |
1859 | ||
1860 | If the notifier call chain should be failed with some events | |
1861 | notified, write the error code to "actions/<notifier event>/error". | |
1862 | ||
1863 | Example: Inject PM suspend error (-12 = -ENOMEM) | |
1864 | ||
1865 | # cd /sys/kernel/debug/notifier-error-inject/pm/ | |
1866 | # echo -12 > actions/PM_SUSPEND_PREPARE/error | |
1867 | # echo mem > /sys/power/state | |
1868 | bash: echo: write error: Cannot allocate memory | |
1869 | ||
1870 | To compile this code as a module, choose M here: the module will | |
1871 | be called pm-notifier-error-inject. | |
1872 | ||
1873 | If unsure, say N. | |
1874 | ||
d526e85f BH |
1875 | config OF_RECONFIG_NOTIFIER_ERROR_INJECT |
1876 | tristate "OF reconfig notifier error injection module" | |
1877 | depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION | |
08dfb4dd | 1878 | help |
e41e85cc | 1879 | This option provides the ability to inject artificial errors to |
d526e85f | 1880 | OF reconfig notifier chain callbacks. It is controlled |
08dfb4dd | 1881 | through debugfs interface under |
d526e85f | 1882 | /sys/kernel/debug/notifier-error-inject/OF-reconfig/ |
08dfb4dd AM |
1883 | |
1884 | If the notifier call chain should be failed with some events | |
1885 | notified, write the error code to "actions/<notifier event>/error". | |
1886 | ||
1887 | To compile this code as a module, choose M here: the module will | |
e12a95f4 | 1888 | be called of-reconfig-notifier-error-inject. |
08dfb4dd AM |
1889 | |
1890 | If unsure, say N. | |
1891 | ||
02fff96a NA |
1892 | config NETDEV_NOTIFIER_ERROR_INJECT |
1893 | tristate "Netdev notifier error injection module" | |
1894 | depends on NET && NOTIFIER_ERROR_INJECTION | |
1895 | help | |
1896 | This option provides the ability to inject artificial errors to | |
1897 | netdevice notifier chain callbacks. It is controlled through debugfs | |
1898 | interface /sys/kernel/debug/notifier-error-inject/netdev | |
1899 | ||
1900 | If the notifier call chain should be failed with some events | |
1901 | notified, write the error code to "actions/<notifier event>/error". | |
1902 | ||
1903 | Example: Inject netdevice mtu change error (-22 = -EINVAL) | |
1904 | ||
1905 | # cd /sys/kernel/debug/notifier-error-inject/netdev | |
1906 | # echo -22 > actions/NETDEV_CHANGEMTU/error | |
1907 | # ip link set eth0 mtu 1024 | |
1908 | RTNETLINK answers: Invalid argument | |
1909 | ||
1910 | To compile this code as a module, choose M here: the module will | |
1911 | be called netdev-notifier-error-inject. | |
1912 | ||
1913 | If unsure, say N. | |
1914 | ||
f1b4bd06 | 1915 | config FUNCTION_ERROR_INJECTION |
a4412fdd | 1916 | bool "Fault-injections of functions" |
f1b4bd06 | 1917 | depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES |
a4412fdd SRG |
1918 | help |
1919 | Add fault injections into various functions that are annotated with | |
1920 | ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return | |
1921 | value of theses functions. This is useful to test error paths of code. | |
1922 | ||
1923 | If unsure, say N | |
f1b4bd06 | 1924 | |
6ff1cb35 | 1925 | config FAULT_INJECTION |
1ab8509a AM |
1926 | bool "Fault-injection framework" |
1927 | depends on DEBUG_KERNEL | |
329409ae AM |
1928 | help |
1929 | Provide fault-injection framework. | |
1930 | For more details, see Documentation/fault-injection/. | |
6ff1cb35 | 1931 | |
8a8b6502 | 1932 | config FAILSLAB |
1ab8509a AM |
1933 | bool "Fault-injection capability for kmalloc" |
1934 | depends on FAULT_INJECTION | |
773ff60e | 1935 | depends on SLAB || SLUB |
8a8b6502 | 1936 | help |
1ab8509a | 1937 | Provide fault-injection capability for kmalloc. |
8a8b6502 | 1938 | |
933e312e | 1939 | config FAIL_PAGE_ALLOC |
29b46fa3 | 1940 | bool "Fault-injection capability for alloc_pages()" |
1ab8509a | 1941 | depends on FAULT_INJECTION |
933e312e | 1942 | help |
1ab8509a | 1943 | Provide fault-injection capability for alloc_pages(). |
933e312e | 1944 | |
2c739ced AL |
1945 | config FAULT_INJECTION_USERCOPY |
1946 | bool "Fault injection capability for usercopy functions" | |
1947 | depends on FAULT_INJECTION | |
1948 | help | |
1949 | Provides fault-injection capability to inject failures | |
1950 | in usercopy functions (copy_from_user(), get_user(), ...). | |
1951 | ||
c17bb495 | 1952 | config FAIL_MAKE_REQUEST |
86327d19 | 1953 | bool "Fault-injection capability for disk IO" |
581d4e28 | 1954 | depends on FAULT_INJECTION && BLOCK |
c17bb495 | 1955 | help |
1ab8509a | 1956 | Provide fault-injection capability for disk IO. |
c17bb495 | 1957 | |
581d4e28 | 1958 | config FAIL_IO_TIMEOUT |
f4d01439 | 1959 | bool "Fault-injection capability for faking disk interrupts" |
581d4e28 JA |
1960 | depends on FAULT_INJECTION && BLOCK |
1961 | help | |
1962 | Provide fault-injection capability on end IO handling. This | |
1963 | will make the block layer "forget" an interrupt as configured, | |
1964 | thus exercising the error handling. | |
1965 | ||
1966 | Only works with drivers that use the generic timeout handling, | |
9dbbc3b9 | 1967 | for others it won't do anything. |
581d4e28 | 1968 | |
ab51fbab DB |
1969 | config FAIL_FUTEX |
1970 | bool "Fault-injection capability for futexes" | |
1971 | select DEBUG_FS | |
1972 | depends on FAULT_INJECTION && FUTEX | |
1973 | help | |
1974 | Provide fault-injection capability for futexes. | |
1975 | ||
f1b4bd06 MP |
1976 | config FAULT_INJECTION_DEBUG_FS |
1977 | bool "Debugfs entries for fault-injection capabilities" | |
1978 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS | |
1979 | help | |
1980 | Enable configuration of fault-injection capabilities via debugfs. | |
1981 | ||
4b1a29a7 MH |
1982 | config FAIL_FUNCTION |
1983 | bool "Fault-injection capability for functions" | |
1984 | depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION | |
1985 | help | |
1986 | Provide function-based fault-injection capability. | |
1987 | This will allow you to override a specific function with a return | |
1988 | with given return value. As a result, function caller will see | |
1989 | an error value and have to handle it. This is useful to test the | |
1990 | error handling in various subsystems. | |
1991 | ||
f1b4bd06 MP |
1992 | config FAIL_MMC_REQUEST |
1993 | bool "Fault-injection capability for MMC IO" | |
1994 | depends on FAULT_INJECTION_DEBUG_FS && MMC | |
6ff1cb35 | 1995 | help |
f1b4bd06 MP |
1996 | Provide fault-injection capability for MMC IO. |
1997 | This will make the mmc core return data errors. This is | |
1998 | useful to test the error handling in the mmc block device | |
1999 | and to test how the mmc host driver handles retries from | |
2000 | the block device. | |
1df49008 | 2001 | |
c782af25 CL |
2002 | config FAIL_SUNRPC |
2003 | bool "Fault-injection capability for SunRPC" | |
2004 | depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG | |
2005 | help | |
2006 | Provide fault-injection capability for SunRPC and | |
2007 | its consumers. | |
2008 | ||
1df49008 AM |
2009 | config FAULT_INJECTION_STACKTRACE_FILTER |
2010 | bool "stacktrace filter for fault-injection capabilities" | |
2011 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT | |
2012 | select STACKTRACE | |
7d37cb2c | 2013 | depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86 |
1df49008 AM |
2014 | help |
2015 | Provide stacktrace filter for fault-injection capabilities | |
267c4025 | 2016 | |
09a74952 CD |
2017 | config ARCH_HAS_KCOV |
2018 | bool | |
cc3fa840 | 2019 | help |
09a74952 CD |
2020 | An architecture should select this when it can successfully |
2021 | build and run with CONFIG_KCOV. This typically requires | |
2022 | disabling instrumentation for some early boot code. | |
cc3fa840 | 2023 | |
09a74952 CD |
2024 | config CC_HAS_SANCOV_TRACE_PC |
2025 | def_bool $(cc-option,-fsanitize-coverage=trace-pc) | |
cc3fa840 | 2026 | |
cc3fa840 | 2027 | |
09a74952 CD |
2028 | config KCOV |
2029 | bool "Code coverage for fuzzing" | |
2030 | depends on ARCH_HAS_KCOV | |
2031 | depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS | |
22102f45 | 2032 | depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \ |
bece04b5 | 2033 | GCC_VERSION >= 120000 || CLANG_VERSION >= 130000 |
09a74952 CD |
2034 | select DEBUG_FS |
2035 | select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC | |
22102f45 | 2036 | select OBJTOOL if HAVE_NOINSTR_HACK |
09a74952 CD |
2037 | help |
2038 | KCOV exposes kernel code coverage information in a form suitable | |
2039 | for coverage-guided fuzzing (randomized testing). | |
cc3fa840 | 2040 | |
09a74952 CD |
2041 | If RANDOMIZE_BASE is enabled, PC values will not be stable across |
2042 | different machines and across reboots. If you need stable PC values, | |
2043 | disable RANDOMIZE_BASE. | |
cc3fa840 | 2044 | |
09a74952 | 2045 | For more details, see Documentation/dev-tools/kcov.rst. |
cc3fa840 | 2046 | |
09a74952 CD |
2047 | config KCOV_ENABLE_COMPARISONS |
2048 | bool "Enable comparison operands collection by KCOV" | |
2049 | depends on KCOV | |
2050 | depends on $(cc-option,-fsanitize-coverage=trace-cmp) | |
2051 | help | |
2052 | KCOV also exposes operands of every comparison in the instrumented | |
2053 | code along with operand sizes and PCs of the comparison instructions. | |
2054 | These operands can be used by fuzzing engines to improve the quality | |
2055 | of fuzzing coverage. | |
cc3fa840 | 2056 | |
09a74952 CD |
2057 | config KCOV_INSTRUMENT_ALL |
2058 | bool "Instrument all code by default" | |
2059 | depends on KCOV | |
2060 | default y | |
2061 | help | |
2062 | If you are doing generic system call fuzzing (like e.g. syzkaller), | |
2063 | then you will want to instrument the whole kernel and you should | |
2064 | say y here. If you are doing more targeted fuzzing (like e.g. | |
2065 | filesystem fuzzing with AFL) then you will want to enable coverage | |
2066 | for more specific subsets of files, and should say n here. | |
84bc809e | 2067 | |
5ff3b30a AK |
2068 | config KCOV_IRQ_AREA_SIZE |
2069 | hex "Size of interrupt coverage collection area in words" | |
2070 | depends on KCOV | |
2071 | default 0x40000 | |
2072 | help | |
2073 | KCOV uses preallocated per-cpu areas to collect coverage from | |
2074 | soft interrupts. This specifies the size of those areas in the | |
2075 | number of unsigned long words. | |
2076 | ||
d3deafaa VL |
2077 | menuconfig RUNTIME_TESTING_MENU |
2078 | bool "Runtime Testing" | |
908009e8 | 2079 | def_bool y |
d3deafaa VL |
2080 | |
2081 | if RUNTIME_TESTING_MENU | |
881c5149 DH |
2082 | |
2083 | config LKDTM | |
2084 | tristate "Linux Kernel Dump Test Tool Module" | |
2085 | depends on DEBUG_FS | |
881c5149 DH |
2086 | help |
2087 | This module enables testing of the different dumping mechanisms by | |
2088 | inducing system failures at predefined crash points. | |
2089 | If you don't need it: say N | |
2090 | Choose M here to compile this code as a module. The module will be | |
2091 | called lkdtm. | |
2092 | ||
2093 | Documentation on how to use the module can be found in | |
10ffebbe | 2094 | Documentation/fault-injection/provoke-crashes.rst |
881c5149 | 2095 | |
d3c0ca49 SV |
2096 | config CPUMASK_KUNIT_TEST |
2097 | tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS | |
c41e8866 SV |
2098 | depends on KUNIT |
2099 | default KUNIT_ALL_TESTS | |
2100 | help | |
2101 | Enable to turn on cpumask tests, running at boot or module load time. | |
2102 | ||
d3c0ca49 SV |
2103 | For more information on KUnit and unit tests in general, please refer |
2104 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2105 | ||
c41e8866 SV |
2106 | If unsure, say N. |
2107 | ||
881c5149 | 2108 | config TEST_LIST_SORT |
ebd09577 DL |
2109 | tristate "Linked list sorting test" if !KUNIT_ALL_TESTS |
2110 | depends on KUNIT | |
2111 | default KUNIT_ALL_TESTS | |
881c5149 DH |
2112 | help |
2113 | Enable this to turn on 'list_sort()' function test. This test is | |
e327fd7c GU |
2114 | executed only once during system boot (so affects only boot time), |
2115 | or at module load time. | |
881c5149 DH |
2116 | |
2117 | If unsure, say N. | |
2118 | ||
6e24628d IR |
2119 | config TEST_MIN_HEAP |
2120 | tristate "Min heap test" | |
2121 | depends on DEBUG_KERNEL || m | |
2122 | help | |
2123 | Enable this to turn on min heap function tests. This test is | |
2124 | executed only once during system boot (so affects only boot time), | |
2125 | or at module load time. | |
2126 | ||
2127 | If unsure, say N. | |
2128 | ||
c5adae95 | 2129 | config TEST_SORT |
36f33b56 DL |
2130 | tristate "Array-based sort test" if !KUNIT_ALL_TESTS |
2131 | depends on KUNIT | |
2132 | default KUNIT_ALL_TESTS | |
c5adae95 | 2133 | help |
5c4e6798 GU |
2134 | This option enables the self-test function of 'sort()' at boot, |
2135 | or at module load time. | |
c5adae95 KF |
2136 | |
2137 | If unsure, say N. | |
2138 | ||
5086ea4b MR |
2139 | config TEST_DIV64 |
2140 | tristate "64bit/32bit division and modulo test" | |
2141 | depends on DEBUG_KERNEL || m | |
2142 | help | |
2143 | Enable this to turn on 'do_div()' function test. This test is | |
2144 | executed only once during system boot (so affects only boot time), | |
2145 | or at module load time. | |
2146 | ||
2147 | If unsure, say N. | |
2148 | ||
881c5149 | 2149 | config KPROBES_SANITY_TEST |
dcbb2ee2 | 2150 | tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS |
881c5149 DH |
2151 | depends on DEBUG_KERNEL |
2152 | depends on KPROBES | |
e44e81c5 | 2153 | depends on KUNIT |
de3db3f8 | 2154 | select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE |
dcbb2ee2 | 2155 | default KUNIT_ALL_TESTS |
881c5149 DH |
2156 | help |
2157 | This option provides for testing basic kprobes functionality on | |
5a6cf77f | 2158 | boot. Samples of kprobe and kretprobe are inserted and |
881c5149 DH |
2159 | verified for functionality. |
2160 | ||
2161 | Say N if you are unsure. | |
2162 | ||
f4616fab MH |
2163 | config FPROBE_SANITY_TEST |
2164 | bool "Self test for fprobe" | |
2165 | depends on DEBUG_KERNEL | |
2166 | depends on FPROBE | |
2167 | depends on KUNIT=y | |
2168 | help | |
2169 | This option will enable testing the fprobe when the system boot. | |
2170 | A series of tests are made to verify that the fprobe is functioning | |
2171 | properly. | |
2172 | ||
2173 | Say N if you are unsure. | |
2174 | ||
881c5149 DH |
2175 | config BACKTRACE_SELF_TEST |
2176 | tristate "Self test for the backtrace code" | |
2177 | depends on DEBUG_KERNEL | |
881c5149 DH |
2178 | help |
2179 | This option provides a kernel module that can be used to test | |
2180 | the kernel stack backtrace code. This option is not useful | |
2181 | for distributions or general kernels, but only for kernel | |
2182 | developers working on architecture code. | |
2183 | ||
2184 | Note that if you want to also test saved backtraces, you will | |
2185 | have to enable STACKTRACE as well. | |
2186 | ||
2187 | Say N if you are unsure. | |
2188 | ||
914a7b50 ED |
2189 | config TEST_REF_TRACKER |
2190 | tristate "Self test for reference tracker" | |
2191 | depends on DEBUG_KERNEL && STACKTRACE_SUPPORT | |
2192 | select REF_TRACKER | |
2193 | help | |
2194 | This option provides a kernel module performing tests | |
2195 | using reference tracker infrastructure. | |
2196 | ||
2197 | Say N if you are unsure. | |
2198 | ||
910a742d ML |
2199 | config RBTREE_TEST |
2200 | tristate "Red-Black tree test" | |
7c993e11 | 2201 | depends on DEBUG_KERNEL |
910a742d ML |
2202 | help |
2203 | A benchmark measuring the performance of the rbtree library. | |
2204 | Also includes rbtree invariant checks. | |
2205 | ||
4b4f3acc FB |
2206 | config REED_SOLOMON_TEST |
2207 | tristate "Reed-Solomon library test" | |
2208 | depends on DEBUG_KERNEL || m | |
2209 | select REED_SOLOMON | |
2210 | select REED_SOLOMON_ENC16 | |
2211 | select REED_SOLOMON_DEC16 | |
2212 | help | |
2213 | This option enables the self-test function of rslib at boot, | |
2214 | or at module load time. | |
2215 | ||
2216 | If unsure, say N. | |
2217 | ||
fff3fd8a ML |
2218 | config INTERVAL_TREE_TEST |
2219 | tristate "Interval tree test" | |
0f789b67 | 2220 | depends on DEBUG_KERNEL |
a88cc108 | 2221 | select INTERVAL_TREE |
fff3fd8a ML |
2222 | help |
2223 | A benchmark measuring the performance of the interval tree library | |
2224 | ||
623fd807 GT |
2225 | config PERCPU_TEST |
2226 | tristate "Per cpu operations test" | |
2227 | depends on m && DEBUG_KERNEL | |
2228 | help | |
2229 | Enable this option to build test module which validates per-cpu | |
2230 | operations. | |
2231 | ||
2232 | If unsure, say N. | |
2233 | ||
881c5149 | 2234 | config ATOMIC64_SELFTEST |
55ded955 | 2235 | tristate "Perform an atomic64_t self-test" |
881c5149 | 2236 | help |
55ded955 GU |
2237 | Enable this option to test the atomic64_t functions at boot or |
2238 | at module load time. | |
881c5149 DH |
2239 | |
2240 | If unsure, say N. | |
2241 | ||
2242 | config ASYNC_RAID6_TEST | |
2243 | tristate "Self test for hardware accelerated raid6 recovery" | |
2244 | depends on ASYNC_RAID6_RECOV | |
2245 | select ASYNC_MEMCPY | |
a7f7f624 | 2246 | help |
881c5149 DH |
2247 | This is a one-shot self test that permutes through the |
2248 | recovery of all the possible two disk failure scenarios for a | |
2249 | N-disk array. Recovery is performed with the asynchronous | |
2250 | raid6 recovery routines, and will optionally use an offload | |
2251 | engine if one is available. | |
2252 | ||
2253 | If unsure, say N. | |
2254 | ||
64d1d77a AS |
2255 | config TEST_HEXDUMP |
2256 | tristate "Test functions located in the hexdump module at runtime" | |
2257 | ||
b2ff70a0 MC |
2258 | config STRING_SELFTEST |
2259 | tristate "Test string functions at runtime" | |
2260 | ||
881c5149 DH |
2261 | config TEST_STRING_HELPERS |
2262 | tristate "Test functions located in the string_helpers module at runtime" | |
2263 | ||
2264 | config TEST_KSTRTOX | |
2265 | tristate "Test kstrto*() family of functions at runtime" | |
2266 | ||
707cc728 RV |
2267 | config TEST_PRINTF |
2268 | tristate "Test printf() family of functions at runtime" | |
2269 | ||
50f530e1 RF |
2270 | config TEST_SCANF |
2271 | tristate "Test scanf() family of functions at runtime" | |
2272 | ||
5fd003f5 DD |
2273 | config TEST_BITMAP |
2274 | tristate "Test bitmap_*() family of functions at runtime" | |
5fd003f5 DD |
2275 | help |
2276 | Enable this option to test the bitmap functions at boot. | |
2277 | ||
2278 | If unsure, say N. | |
2279 | ||
cfaff0e5 AS |
2280 | config TEST_UUID |
2281 | tristate "Test functions located in the uuid module at runtime" | |
2282 | ||
ad3d6c72 MW |
2283 | config TEST_XARRAY |
2284 | tristate "Test the XArray code at runtime" | |
2285 | ||
120b1162 | 2286 | config TEST_MAPLE_TREE |
845aad0a | 2287 | depends on DEBUG_KERNEL |
120b1162 LH |
2288 | select DEBUG_MAPLE_TREE |
2289 | tristate "Test the Maple Tree code at runtime" | |
2290 | ||
7e1e7763 | 2291 | config TEST_RHASHTABLE |
9d6dbe1b | 2292 | tristate "Perform selftest on resizable hash table" |
7e1e7763 TG |
2293 | help |
2294 | Enable this option to test the rhashtable functions at boot. | |
2295 | ||
2296 | If unsure, say N. | |
2297 | ||
8ab8ba38 MW |
2298 | config TEST_IDA |
2299 | tristate "Perform selftest on IDA functions" | |
2300 | ||
44091d29 JP |
2301 | config TEST_PARMAN |
2302 | tristate "Perform selftest on priority array manager" | |
44091d29 JP |
2303 | depends on PARMAN |
2304 | help | |
2305 | Enable this option to test priority array manager on boot | |
2306 | (or module load). | |
2307 | ||
2308 | If unsure, say N. | |
2309 | ||
6aed82de DL |
2310 | config TEST_IRQ_TIMINGS |
2311 | bool "IRQ timings selftest" | |
2312 | depends on IRQ_TIMINGS | |
2313 | help | |
2314 | Enable this option to test the irq timings code on boot. | |
2315 | ||
2316 | If unsure, say N. | |
2317 | ||
8a6f0b47 | 2318 | config TEST_LKM |
93e9ef83 | 2319 | tristate "Test module loading with 'hello world' module" |
93e9ef83 KC |
2320 | depends on m |
2321 | help | |
2322 | This builds the "test_module" module that emits "Hello, world" | |
2323 | on printk when loaded. It is designed to be used for basic | |
2324 | evaluation of the module loading subsystem (for example when | |
2325 | validating module verification). It lacks any extra dependencies, | |
2326 | and will not normally be loaded by the system unless explicitly | |
2327 | requested by name. | |
2328 | ||
2329 | If unsure, say N. | |
2330 | ||
c348c163 | 2331 | config TEST_BITOPS |
6af132f3 | 2332 | tristate "Test module for compilation of bitops operations" |
c348c163 JB |
2333 | depends on m |
2334 | help | |
2335 | This builds the "test_bitops" module that is much like the | |
2336 | TEST_LKM module except that it does a basic exercise of the | |
6af132f3 WY |
2337 | set/clear_bit macros and get_count_order/long to make sure there are |
2338 | no compiler warnings from C=1 sparse checker or -Wextra | |
2339 | compilations. It has no dependencies and doesn't run or load unless | |
2340 | explicitly requested by name. for example: modprobe test_bitops. | |
c348c163 JB |
2341 | |
2342 | If unsure, say N. | |
2343 | ||
3f21a6b7 URS |
2344 | config TEST_VMALLOC |
2345 | tristate "Test module for stress/performance analysis of vmalloc allocator" | |
2346 | default n | |
2347 | depends on MMU | |
2348 | depends on m | |
2349 | help | |
2350 | This builds the "test_vmalloc" module that should be used for | |
2351 | stress and performance analysis. So, any new change for vmalloc | |
2352 | subsystem can be evaluated from performance and stability point | |
2353 | of view. | |
2354 | ||
2355 | If unsure, say N. | |
2356 | ||
3e2a4c18 KC |
2357 | config TEST_USER_COPY |
2358 | tristate "Test user/kernel boundary protections" | |
3e2a4c18 KC |
2359 | depends on m |
2360 | help | |
2361 | This builds the "test_user_copy" module that runs sanity checks | |
2362 | on the copy_to/from_user infrastructure, making sure basic | |
2363 | user/kernel boundary testing is working. If it fails to load, | |
2364 | a regression has been detected in the user/kernel memory boundary | |
2365 | protections. | |
2366 | ||
2367 | If unsure, say N. | |
2368 | ||
64a8946b AS |
2369 | config TEST_BPF |
2370 | tristate "Test BPF filter functionality" | |
98920ba6 | 2371 | depends on m && NET |
64a8946b AS |
2372 | help |
2373 | This builds the "test_bpf" module that runs various test vectors | |
2374 | against the BPF interpreter or BPF JIT compiler depending on the | |
2375 | current setting. This is in particular useful for BPF JIT compiler | |
2376 | development, but also to run regression tests against changes in | |
3c731eba AS |
2377 | the interpreter code. It also enables test stubs for eBPF maps and |
2378 | verifier used by user space verifier testsuite. | |
64a8946b AS |
2379 | |
2380 | If unsure, say N. | |
2381 | ||
509e56b3 MB |
2382 | config TEST_BLACKHOLE_DEV |
2383 | tristate "Test blackhole netdev functionality" | |
2384 | depends on m && NET | |
2385 | help | |
2386 | This builds the "test_blackhole_dev" module that validates the | |
2387 | data path through this blackhole netdev. | |
2388 | ||
2389 | If unsure, say N. | |
2390 | ||
dceeb3e7 | 2391 | config FIND_BIT_BENCHMARK |
4441fca0 | 2392 | tristate "Test find_bit functions" |
4441fca0 YN |
2393 | help |
2394 | This builds the "test_find_bit" module that measure find_*_bit() | |
2395 | functions performance. | |
2396 | ||
2397 | If unsure, say N. | |
2398 | ||
0a8adf58 KC |
2399 | config TEST_FIRMWARE |
2400 | tristate "Test firmware loading via userspace interface" | |
0a8adf58 KC |
2401 | depends on FW_LOADER |
2402 | help | |
2403 | This builds the "test_firmware" module that creates a userspace | |
2404 | interface for testing firmware loading. This can be used to | |
2405 | control the triggering of firmware loading without needing an | |
2406 | actual firmware-using device. The contents can be rechecked by | |
2407 | userspace. | |
2408 | ||
2409 | If unsure, say N. | |
2410 | ||
9308f2f9 LR |
2411 | config TEST_SYSCTL |
2412 | tristate "sysctl test driver" | |
9308f2f9 LR |
2413 | depends on PROC_SYSCTL |
2414 | help | |
2415 | This builds the "test_sysctl" module. This driver enables to test the | |
2416 | proc sysctl interfaces available to drivers safely without affecting | |
2417 | production knobs which might alter system functionality. | |
2418 | ||
2419 | If unsure, say N. | |
2420 | ||
d2585f51 | 2421 | config BITFIELD_KUNIT |
dcbb2ee2 | 2422 | tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS |
d2585f51 | 2423 | depends on KUNIT |
dcbb2ee2 | 2424 | default KUNIT_ALL_TESTS |
d2585f51 VMI |
2425 | help |
2426 | Enable this option to test the bitfield functions at boot. | |
2427 | ||
2428 | KUnit tests run during boot and output the results to the debug log | |
2429 | in TAP format (http://testanything.org/). Only useful for kernel devs | |
2430 | running the KUnit test harness, and not intended for inclusion into a | |
2431 | production build. | |
2432 | ||
2433 | For more information on KUnit and unit tests in general please refer | |
2434 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2435 | ||
2436 | If unsure, say N. | |
2437 | ||
0acc968f IB |
2438 | config HASH_KUNIT_TEST |
2439 | tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS | |
2440 | depends on KUNIT | |
2441 | default KUNIT_ALL_TESTS | |
2442 | help | |
2443 | Enable this option to test the kernel's string (<linux/stringhash.h>), and | |
2444 | integer (<linux/hash.h>) hash functions on boot. | |
2445 | ||
2446 | KUnit tests run during boot and output the results to the debug log | |
2447 | in TAP format (https://testanything.org/). Only useful for kernel devs | |
2448 | running the KUnit test harness, and not intended for inclusion into a | |
2449 | production build. | |
2450 | ||
2451 | For more information on KUnit and unit tests in general please refer | |
2452 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2453 | ||
2454 | This is intended to help people writing architecture-specific | |
2455 | optimized versions. If unsure, say N. | |
2456 | ||
5df38ca6 | 2457 | config RESOURCE_KUNIT_TEST |
dcbb2ee2 | 2458 | tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS |
5df38ca6 | 2459 | depends on KUNIT |
dcbb2ee2 | 2460 | default KUNIT_ALL_TESTS |
5df38ca6 AS |
2461 | help |
2462 | This builds the resource API unit test. | |
2463 | Tests the logic of API provided by resource.c and ioport.h. | |
2464 | For more information on KUnit and unit tests in general please refer | |
2465 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2466 | ||
2467 | If unsure, say N. | |
2468 | ||
2cb80dbb | 2469 | config SYSCTL_KUNIT_TEST |
5f215aab | 2470 | tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS |
2cb80dbb | 2471 | depends on KUNIT |
5f215aab | 2472 | default KUNIT_ALL_TESTS |
2cb80dbb IZ |
2473 | help |
2474 | This builds the proc sysctl unit test, which runs on boot. | |
2475 | Tests the API contract and implementation correctness of sysctl. | |
2476 | For more information on KUnit and unit tests in general please refer | |
2477 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2478 | ||
2479 | If unsure, say N. | |
2480 | ||
ea2dd7c0 | 2481 | config LIST_KUNIT_TEST |
5f215aab | 2482 | tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS |
ea2dd7c0 | 2483 | depends on KUNIT |
5f215aab | 2484 | default KUNIT_ALL_TESTS |
ea2dd7c0 DG |
2485 | help |
2486 | This builds the linked list KUnit test suite. | |
2487 | It tests that the API and basic functionality of the list_head type | |
2488 | and associated macros. | |
2489 | ||
2490 | KUnit tests run during boot and output the results to the debug log | |
d89775fc | 2491 | in TAP format (https://testanything.org/). Only useful for kernel devs |
ea2dd7c0 DG |
2492 | running the KUnit test harness, and not intended for inclusion into a |
2493 | production build. | |
2494 | ||
2495 | For more information on KUnit and unit tests in general please refer | |
2496 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2497 | ||
2498 | If unsure, say N. | |
2499 | ||
33d599f0 MV |
2500 | config LINEAR_RANGES_TEST |
2501 | tristate "KUnit test for linear_ranges" | |
2502 | depends on KUNIT | |
2503 | select LINEAR_RANGES | |
2504 | help | |
2505 | This builds the linear_ranges unit test, which runs on boot. | |
2506 | Tests the linear_ranges logic correctness. | |
2507 | For more information on KUnit and unit tests in general please refer | |
7546861a AS |
2508 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
2509 | ||
2510 | If unsure, say N. | |
2511 | ||
2512 | config CMDLINE_KUNIT_TEST | |
dcbb2ee2 | 2513 | tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS |
7546861a | 2514 | depends on KUNIT |
dcbb2ee2 | 2515 | default KUNIT_ALL_TESTS |
7546861a AS |
2516 | help |
2517 | This builds the cmdline API unit test. | |
2518 | Tests the logic of API provided by cmdline.c. | |
2519 | For more information on KUnit and unit tests in general please refer | |
33d599f0 MV |
2520 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
2521 | ||
2522 | If unsure, say N. | |
2523 | ||
6d511020 | 2524 | config BITS_TEST |
dcbb2ee2 | 2525 | tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS |
6d511020 | 2526 | depends on KUNIT |
dcbb2ee2 | 2527 | default KUNIT_ALL_TESTS |
6d511020 RF |
2528 | help |
2529 | This builds the bits unit test. | |
2530 | Tests the logic of macros defined in bits.h. | |
2531 | For more information on KUnit and unit tests in general please refer | |
2532 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2533 | ||
2534 | If unsure, say N. | |
2535 | ||
1f9f78b1 OG |
2536 | config SLUB_KUNIT_TEST |
2537 | tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS | |
2538 | depends on SLUB_DEBUG && KUNIT | |
2539 | default KUNIT_ALL_TESTS | |
2540 | help | |
2541 | This builds SLUB allocator unit test. | |
2542 | Tests SLUB cache debugging functionality. | |
2543 | For more information on KUnit and unit tests in general please refer | |
2544 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2545 | ||
2546 | If unsure, say N. | |
2547 | ||
b6c75c4a TP |
2548 | config RATIONAL_KUNIT_TEST |
2549 | tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS | |
8ba739ed | 2550 | depends on KUNIT && RATIONAL |
b6c75c4a TP |
2551 | default KUNIT_ALL_TESTS |
2552 | help | |
2553 | This builds the rational math unit test. | |
2554 | For more information on KUnit and unit tests in general please refer | |
2555 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2556 | ||
2557 | If unsure, say N. | |
2558 | ||
bb95ebbe KC |
2559 | config MEMCPY_KUNIT_TEST |
2560 | tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS | |
2561 | depends on KUNIT | |
2562 | default KUNIT_ALL_TESTS | |
2563 | help | |
2564 | Builds unit tests for memcpy(), memmove(), and memset() functions. | |
2565 | For more information on KUnit and unit tests in general please refer | |
2566 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2567 | ||
2568 | If unsure, say N. | |
2569 | ||
addbeea6 BVA |
2570 | config IS_SIGNED_TYPE_KUNIT_TEST |
2571 | tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS | |
2572 | depends on KUNIT | |
2573 | default KUNIT_ALL_TESTS | |
2574 | help | |
2575 | Builds unit tests for the is_signed_type() macro. | |
2576 | ||
2577 | For more information on KUnit and unit tests in general please refer | |
2578 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2579 | ||
2580 | If unsure, say N. | |
2581 | ||
617f55e2 KC |
2582 | config OVERFLOW_KUNIT_TEST |
2583 | tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS | |
2584 | depends on KUNIT | |
2585 | default KUNIT_ALL_TESTS | |
2586 | help | |
2587 | Builds unit tests for the check_*_overflow(), size_*(), allocation, and | |
2588 | related functions. | |
2589 | ||
2590 | For more information on KUnit and unit tests in general please refer | |
2591 | to the KUnit documentation in Documentation/dev-tools/kunit/. | |
2592 | ||
2593 | If unsure, say N. | |
2594 | ||
02788ebc KC |
2595 | config STACKINIT_KUNIT_TEST |
2596 | tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS | |
2597 | depends on KUNIT | |
2598 | default KUNIT_ALL_TESTS | |
2599 | help | |
2600 | Test if the kernel is zero-initializing stack variables and | |
2601 | padding. Coverage is controlled by compiler flags, | |
2602 | CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO, | |
2603 | CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF, | |
2604 | or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL. | |
2605 | ||
875bfd52 KC |
2606 | config FORTIFY_KUNIT_TEST |
2607 | tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS | |
2608 | depends on KUNIT && FORTIFY_SOURCE | |
2609 | default KUNIT_ALL_TESTS | |
2610 | help | |
2611 | Builds unit tests for checking internals of FORTIFY_SOURCE as used | |
2612 | by the str*() and mem*() family of functions. For testing runtime | |
2613 | traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests. | |
2614 | ||
724c299c ME |
2615 | config HW_BREAKPOINT_KUNIT_TEST |
2616 | bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS | |
2617 | depends on HAVE_HW_BREAKPOINT | |
2618 | depends on KUNIT=y | |
2619 | default KUNIT_ALL_TESTS | |
2620 | help | |
2621 | Tests for hw_breakpoint constraints accounting. | |
2622 | ||
2623 | If unsure, say N. | |
2624 | ||
41eefc46 KC |
2625 | config STRSCPY_KUNIT_TEST |
2626 | tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS | |
2627 | depends on KUNIT | |
2628 | default KUNIT_ALL_TESTS | |
2629 | ||
fb3d88ab KC |
2630 | config SIPHASH_KUNIT_TEST |
2631 | tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS | |
2632 | depends on KUNIT | |
2633 | default KUNIT_ALL_TESTS | |
2634 | help | |
2635 | Enable this option to test the kernel's siphash (<linux/siphash.h>) hash | |
2636 | functions on boot (or module load). | |
2637 | ||
2638 | This is intended to help people writing architecture-specific | |
2639 | optimized versions. If unsure, say N. | |
2640 | ||
e704f93a DR |
2641 | config TEST_UDELAY |
2642 | tristate "udelay test driver" | |
e704f93a DR |
2643 | help |
2644 | This builds the "udelay_test" module that helps to make sure | |
2645 | that udelay() is working properly. | |
2646 | ||
2647 | If unsure, say N. | |
2648 | ||
2bf9e0ab IM |
2649 | config TEST_STATIC_KEYS |
2650 | tristate "Test static keys" | |
579e1acb JB |
2651 | depends on m |
2652 | help | |
2bf9e0ab | 2653 | Test the static key interfaces. |
579e1acb JB |
2654 | |
2655 | If unsure, say N. | |
2656 | ||
683263a5 JC |
2657 | config TEST_DYNAMIC_DEBUG |
2658 | tristate "Test DYNAMIC_DEBUG" | |
2659 | depends on DYNAMIC_DEBUG | |
2660 | help | |
2661 | This module registers a tracer callback to count enabled | |
2662 | pr_debugs in a 'do_debugging' function, then alters their | |
2663 | enablements, calls the function, and compares counts. | |
2664 | ||
2665 | If unsure, say N. | |
2666 | ||
d9c6a72d LR |
2667 | config TEST_KMOD |
2668 | tristate "kmod stress tester" | |
d9c6a72d | 2669 | depends on m |
d9c6a72d | 2670 | depends on NETDEVICES && NET_CORE && INET # for TUN |
ae3d6a32 | 2671 | depends on BLOCK |
bbd2e05f | 2672 | depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS |
d9c6a72d LR |
2673 | select TEST_LKM |
2674 | select XFS_FS | |
2675 | select TUN | |
2676 | select BTRFS_FS | |
2677 | help | |
2678 | Test the kernel's module loading mechanism: kmod. kmod implements | |
2679 | support to load modules using the Linux kernel's usermode helper. | |
2680 | This test provides a series of tests against kmod. | |
2681 | ||
2682 | Although technically you can either build test_kmod as a module or | |
2683 | into the kernel we disallow building it into the kernel since | |
2684 | it stress tests request_module() and this will very likely cause | |
2685 | some issues by taking over precious threads available from other | |
2686 | module load requests, ultimately this could be fatal. | |
2687 | ||
2688 | To run tests run: | |
2689 | ||
2690 | tools/testing/selftests/kmod/kmod.sh --help | |
2691 | ||
2692 | If unsure, say N. | |
2693 | ||
e4dace36 FF |
2694 | config TEST_DEBUG_VIRTUAL |
2695 | tristate "Test CONFIG_DEBUG_VIRTUAL feature" | |
2696 | depends on DEBUG_VIRTUAL | |
2697 | help | |
2698 | Test the kernel's ability to detect incorrect calls to | |
2699 | virt_to_phys() done against the non-linear part of the | |
2700 | kernel's virtual address map. | |
2701 | ||
2702 | If unsure, say N. | |
2703 | ||
ce76d938 AS |
2704 | config TEST_MEMCAT_P |
2705 | tristate "Test memcat_p() helper function" | |
2706 | help | |
2707 | Test the memcat_p() helper for correctly merging two | |
2708 | pointer arrays together. | |
2709 | ||
2710 | If unsure, say N. | |
2711 | ||
a2818ee4 JL |
2712 | config TEST_LIVEPATCH |
2713 | tristate "Test livepatching" | |
2714 | default n | |
bae05437 | 2715 | depends on DYNAMIC_DEBUG |
a2818ee4 JL |
2716 | depends on LIVEPATCH |
2717 | depends on m | |
2718 | help | |
2719 | Test kernel livepatching features for correctness. The tests will | |
2720 | load test modules that will be livepatched in various scenarios. | |
2721 | ||
2722 | To run all the livepatching tests: | |
2723 | ||
2724 | make -C tools/testing/selftests TARGETS=livepatch run_tests | |
2725 | ||
2726 | Alternatively, individual tests may be invoked: | |
2727 | ||
2728 | tools/testing/selftests/livepatch/test-callbacks.sh | |
2729 | tools/testing/selftests/livepatch/test-livepatch.sh | |
2730 | tools/testing/selftests/livepatch/test-shadow-vars.sh | |
2731 | ||
2732 | If unsure, say N. | |
2733 | ||
0a020d41 JP |
2734 | config TEST_OBJAGG |
2735 | tristate "Perform selftest on object aggreration manager" | |
2736 | default n | |
2737 | depends on OBJAGG | |
2738 | help | |
2739 | Enable this option to test object aggregation manager on boot | |
2740 | (or module load). | |
2741 | ||
5015a300 AP |
2742 | config TEST_MEMINIT |
2743 | tristate "Test heap/page initialization" | |
2744 | help | |
2745 | Test if the kernel is zero-initializing heap and page allocations. | |
2746 | This can be useful to test init_on_alloc and init_on_free features. | |
2747 | ||
2748 | If unsure, say N. | |
2749 | ||
b2ef9f5a RC |
2750 | config TEST_HMM |
2751 | tristate "Test HMM (Heterogeneous Memory Management)" | |
2752 | depends on TRANSPARENT_HUGEPAGE | |
2753 | depends on DEVICE_PRIVATE | |
2754 | select HMM_MIRROR | |
2755 | select MMU_NOTIFIER | |
2756 | help | |
2757 | This is a pseudo device driver solely for testing HMM. | |
2758 | Say M here if you want to build the HMM test module. | |
2759 | Doing so will allow you to run tools/testing/selftest/vm/hmm-tests. | |
2760 | ||
2761 | If unsure, say N. | |
2762 | ||
e320d301 MWO |
2763 | config TEST_FREE_PAGES |
2764 | tristate "Test freeing pages" | |
2765 | help | |
2766 | Test that a memory leak does not occur due to a race between | |
2767 | freeing a block of pages and a speculative page reference. | |
2768 | Loading this module is safe if your kernel has the bug fixed. | |
2769 | If the bug is not fixed, it will leak gigabytes of memory and | |
2770 | probably OOM your system. | |
2771 | ||
4185b3b9 PA |
2772 | config TEST_FPU |
2773 | tristate "Test floating point operations in kernel space" | |
2774 | depends on X86 && !KCOV_INSTRUMENT_ALL | |
2775 | help | |
2776 | Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu | |
2777 | which will trigger a sequence of floating point operations. This is used | |
2778 | for self-testing floating point control register setting in | |
2779 | kernel_fpu_begin(). | |
2780 | ||
2781 | If unsure, say N. | |
2782 | ||
1253b9b8 PM |
2783 | config TEST_CLOCKSOURCE_WATCHDOG |
2784 | tristate "Test clocksource watchdog in kernel space" | |
2785 | depends on CLOCKSOURCE_WATCHDOG | |
2786 | help | |
2787 | Enable this option to create a kernel module that will trigger | |
2788 | a test of the clocksource watchdog. This module may be loaded | |
2789 | via modprobe or insmod in which case it will run upon being | |
2790 | loaded, or it may be built in, in which case it will run | |
2791 | shortly after boot. | |
2792 | ||
2793 | If unsure, say N. | |
2794 | ||
d3deafaa | 2795 | endif # RUNTIME_TESTING_MENU |
cc3fa840 | 2796 | |
dce44566 AK |
2797 | config ARCH_USE_MEMTEST |
2798 | bool | |
2799 | help | |
2800 | An architecture should select this when it uses early_memtest() | |
2801 | during boot process. | |
2802 | ||
cc3fa840 RD |
2803 | config MEMTEST |
2804 | bool "Memtest" | |
dce44566 | 2805 | depends on ARCH_USE_MEMTEST |
a7f7f624 | 2806 | help |
cc3fa840 | 2807 | This option adds a kernel parameter 'memtest', which allows memtest |
dce44566 | 2808 | to be set and executed. |
cc3fa840 RD |
2809 | memtest=0, mean disabled; -- default |
2810 | memtest=1, mean do 1 test pattern; | |
2811 | ... | |
2812 | memtest=17, mean do 17 test patterns. | |
2813 | If you are unsure how to answer this question, answer N. | |
2814 | ||
21266be9 | 2815 | |
06ec64b8 | 2816 | |
af9ca6f9 BB |
2817 | config HYPERV_TESTING |
2818 | bool "Microsoft Hyper-V driver testing" | |
2819 | default n | |
2820 | depends on HYPERV && DEBUG_FS | |
2821 | help | |
2822 | Select this option to enable Hyper-V vmbus testing. | |
2823 | ||
045f6d79 CD |
2824 | endmenu # "Kernel Testing and Coverage" |
2825 | ||
2f7ab126 MO |
2826 | menu "Rust hacking" |
2827 | ||
2828 | config RUST_DEBUG_ASSERTIONS | |
2829 | bool "Debug assertions" | |
2830 | depends on RUST | |
2831 | help | |
2832 | Enables rustc's `-Cdebug-assertions` codegen option. | |
2833 | ||
2834 | This flag lets you turn `cfg(debug_assertions)` conditional | |
2835 | compilation on or off. This can be used to enable extra debugging | |
2836 | code in development but not in production. For example, it controls | |
2837 | the behavior of the standard library's `debug_assert!` macro. | |
2838 | ||
2839 | Note that this will apply to all Rust code, including `core`. | |
2840 | ||
2841 | If unsure, say N. | |
2842 | ||
2843 | config RUST_OVERFLOW_CHECKS | |
2844 | bool "Overflow checks" | |
2845 | default y | |
2846 | depends on RUST | |
2847 | help | |
2848 | Enables rustc's `-Coverflow-checks` codegen option. | |
2849 | ||
2850 | This flag allows you to control the behavior of runtime integer | |
2851 | overflow. When overflow-checks are enabled, a Rust panic will occur | |
2852 | on overflow. | |
2853 | ||
2854 | Note that this will apply to all Rust code, including `core`. | |
2855 | ||
2856 | If unsure, say Y. | |
2857 | ||
ecaa6ddf GG |
2858 | config RUST_BUILD_ASSERT_ALLOW |
2859 | bool "Allow unoptimized build-time assertions" | |
2860 | depends on RUST | |
2861 | help | |
2862 | Controls how are `build_error!` and `build_assert!` handled during build. | |
2863 | ||
2864 | If calls to them exist in the binary, it may indicate a violated invariant | |
2865 | or that the optimizer failed to verify the invariant during compilation. | |
2866 | ||
2867 | This should not happen, thus by default the build is aborted. However, | |
2868 | as an escape hatch, you can choose Y here to ignore them during build | |
2869 | and let the check be carried at runtime (with `panic!` being called if | |
2870 | the check fails). | |
2871 | ||
2872 | If unsure, say N. | |
2873 | ||
2f7ab126 MO |
2874 | endmenu # "Rust" |
2875 | ||
75442fb0 MCC |
2876 | source "Documentation/Kconfig" |
2877 | ||
06ec64b8 | 2878 | endmenu # Kernel hacking |