1 # SPDX-License-Identifier: GPL-2.0-only <<
2 menu "Kernel hacking" 1 menu "Kernel hacking"
3 2
4 menu "printk and dmesg options" 3 menu "printk and dmesg options"
5 4
6 config PRINTK_TIME 5 config PRINTK_TIME
7 bool "Show timing information on print 6 bool "Show timing information on printks"
8 depends on PRINTK 7 depends on PRINTK
9 help 8 help
10 Selecting this option causes time st 9 Selecting this option causes time stamps of the printk()
11 messages to be added to the output o 10 messages to be added to the output of the syslog() system
12 call and at the console. 11 call and at the console.
13 12
14 The timestamp is always recorded int 13 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifi 14 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp 15 be included, not that the timestamp is recorded.
17 16
18 The behavior is also controlled by t 17 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documen 18 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
20 19
21 config PRINTK_CALLER <<
22 bool "Show caller information on print <<
23 depends on PRINTK <<
24 help <<
25 Selecting this option causes printk( <<
26 in task context) or a caller "proces <<
27 to every message. <<
28 <<
29 This option is intended for environm <<
30 concurrently call printk() for many <<
31 interpret without knowing where thes <<
32 line which was divided into multiple <<
33 <<
34 Since toggling after boot makes the <<
35 no option to enable/disable at the k <<
36 sysfs interface. <<
37 <<
38 config STACKTRACE_BUILD_ID <<
39 bool "Show build ID information in sta <<
40 depends on PRINTK <<
41 help <<
42 Selecting this option adds build ID <<
43 stacktraces printed with the printk <<
44 <<
45 This option is intended for distros <<
46 accessible but can be downloaded giv <<
47 kernel module where the function is <<
48 <<
49 config CONSOLE_LOGLEVEL_DEFAULT 20 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)" 21 int "Default console loglevel (1-15)"
51 range 1 15 22 range 1 15
52 default "7" 23 default "7"
53 help 24 help
54 Default loglevel to determine what w 25 Default loglevel to determine what will be printed on the console.
55 26
56 Setting a default here is equivalent 27 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> co 28 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well. 29 value is specified here as well.
59 30
60 Note: This does not affect the log l 31 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is control 32 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option. 33 option.
63 34
64 config CONSOLE_LOGLEVEL_QUIET 35 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)" 36 int "quiet console loglevel (1-15)"
66 range 1 15 37 range 1 15
67 default "4" 38 default "4"
68 help 39 help
69 loglevel to use when "quiet" is pass 40 loglevel to use when "quiet" is passed on the kernel commandline.
70 41
71 When "quiet" is passed on the kernel 42 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW pa 43 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CON 44 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74 45
75 config MESSAGE_LOGLEVEL_DEFAULT 46 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)" 47 int "Default message log level (1-7)"
77 range 1 7 48 range 1 7
78 default "4" 49 default "4"
79 help 50 help
80 Default log level for printk stateme 51 Default log level for printk statements with no specified priority.
81 52
82 This was hard-coded to KERN_WARNING 53 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely 54 that are auditing their logs closely may want to set it to a lower
84 priority. 55 priority.
85 56
86 Note: This does not affect what mess 57 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use logl 58 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL 59 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89 60
90 config BOOT_PRINTK_DELAY 61 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message b 62 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && G 63 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help 64 help
94 This build option allows you to read 65 This build option allows you to read kernel boot messages
95 by inserting a short delay after eac 66 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the ker 67 specified in milliseconds on the kernel command line,
97 using "boot_delay=N". 68 using "boot_delay=N".
98 69
99 It is likely that you would also nee 70 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value. 71 the "loops per jiffie" value.
101 See a previous boot log for the "lpj 72 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before 73 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adverse 74 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the firs 75 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOC 76 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup condit 77 what it believes to be lockup conditions.
107 78
108 config DYNAMIC_DEBUG 79 config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support" 80 bool "Enable dynamic printk() support"
110 default n 81 default n
111 depends on PRINTK 82 depends on PRINTK
112 depends on (DEBUG_FS || PROC_FS) !! 83 depends on DEBUG_FS
113 select DYNAMIC_DEBUG_CORE <<
114 help 84 help
115 85
116 Compiles debug level messages into t 86 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 87 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 88 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 89 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 90 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 91 enlarges the kernel text size by about 2%.
122 92
123 If a source file is compiled with DE 93 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 94 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 95 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 96 turned on by many CONFIG_*DEBUG* options.
127 97
128 Usage: 98 Usage:
129 99
130 Dynamic debugging is controlled via 100 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' !! 101 which is contained in the 'debugfs' filesystem. Thus, the debugfs
132 Thus, the debugfs or procfs filesyst !! 102 filesystem must first be mounted before making use of this feature.
133 making use of this feature. <<
134 We refer the control file as: <debug 103 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 104 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 105 format for each line of the file is:
137 106
138 filename:lineno [module]functi 107 filename:lineno [module]function flags format
139 108
140 filename : source file of the debug 109 filename : source file of the debug statement
141 lineno : line number of the debug st 110 lineno : line number of the debug statement
142 module : module that contains the de 111 module : module that contains the debug statement
143 function : function that contains th 112 function : function that contains the debug statement
144 flags : '=p' means the line is turne !! 113 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb !! 114 format : the format used for the debug statement
146 115
147 From a live system: 116 From a live system:
148 117
149 nullarbor:~ # cat <debugfs>/dy 118 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 119 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 120 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 121 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 122 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 123
155 Example usage: 124 Example usage:
156 125
157 // enable the message at line 126 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 127 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 128 <debugfs>/dynamic_debug/control
160 129
161 // enable all the messages in 130 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 131 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 132 <debugfs>/dynamic_debug/control
164 133
165 // enable all the messages in 134 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 135 nullarbor:~ # echo -n 'module nfsd +p' >
167 136 <debugfs>/dynamic_debug/control
168 137
169 // enable all 12 messages in t 138 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 139 nullarbor:~ # echo -n 'func svc_process +p' >
171 140 <debugfs>/dynamic_debug/control
172 141
173 // disable all 12 messages in 142 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 143 nullarbor:~ # echo -n 'func svc_process -p' >
175 144 <debugfs>/dynamic_debug/control
176 145
177 See Documentation/admin-guide/dynami 146 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 147 information.
179 148
180 config DYNAMIC_DEBUG_CORE <<
181 bool "Enable core function of dynamic <<
182 depends on PRINTK <<
183 depends on (DEBUG_FS || PROC_FS) <<
184 help <<
185 Enable core functional support of dy <<
186 when you want to tie dynamic debug t <<
187 DYNAMIC_DEBUG_MODULE defined for eac <<
188 the case of embedded system where th <<
189 sensitive for people. <<
190 <<
191 config SYMBOLIC_ERRNAME <<
192 bool "Support symbolic error names in <<
193 default y if PRINTK <<
194 help <<
195 If you say Y here, the kernel's prin <<
196 be able to print symbolic error name <<
197 of the number 28. It makes the kerne <<
198 (about 3KB), but can make the kernel <<
199 <<
200 config DEBUG_BUGVERBOSE <<
201 bool "Verbose BUG() reporting (adds 70 <<
202 depends on BUG && (GENERIC_BUG || HAVE <<
203 default y <<
204 help <<
205 Say Y here to make BUG() panics outp <<
206 of the BUG call as well as the EIP a <<
207 debugging but costs about 70-100K of <<
208 <<
209 endmenu # "printk and dmesg options" 149 endmenu # "printk and dmesg options"
210 150
211 config DEBUG_KERNEL <<
212 bool "Kernel debugging" <<
213 help <<
214 Say Y here if you are developing dri <<
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 mis <<
223 be under a more specific debug optio <<
224 <<
225 menu "Compile-time checks and compiler options 151 menu "Compile-time checks and compiler options"
226 152
227 config DEBUG_INFO 153 config DEBUG_INFO
228 bool !! 154 bool "Compile the kernel with debug info"
229 help !! 155 depends on DEBUG_KERNEL && !COMPILE_TEST
230 A kernel debug info option other tha <<
231 in the "Debug information" choice be <<
232 information will be generated for bu <<
233 <<
234 # Clang generates .uleb128 with label differen <<
235 # older binutils ports do not support when uti <<
236 # relaxation: https://sourceware.org/bugzilla/ <<
237 config AS_HAS_NON_CONST_ULEB128 <<
238 def_bool $(as-instr,.uleb128 .Lexpr_en <<
239 <<
240 choice <<
241 prompt "Debug information" <<
242 depends on DEBUG_KERNEL <<
243 help 156 help
244 Selecting something other than "None !! 157 If you say Y here the resulting kernel image will include
245 that will include debugging info res !! 158 debugging info resulting in a larger kernel image.
246 This adds debug symbols to the kerne 159 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 160 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 161 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
>> 162 Say Y here only if you plan to debug the kernel.
249 163
250 Choose which version of DWARF debug !! 164 If unsure, say N.
251 select "Toolchain default". <<
252 <<
253 config DEBUG_INFO_NONE <<
254 bool "Disable debug information" <<
255 help <<
256 Do not build the kernel with debuggi <<
257 result in a faster and smaller build <<
258 <<
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT <<
260 bool "Rely on the toolchain's implicit <<
261 select DEBUG_INFO <<
262 depends on !CC_IS_CLANG || AS_IS_LLVM <<
263 help <<
264 The implicit default version of DWAR <<
265 toolchain changes over time. <<
266 <<
267 This can break consumers of the debu <<
268 support newer revisions, and prevent <<
269 those should be less common scenario <<
270 <<
271 config DEBUG_INFO_DWARF4 <<
272 bool "Generate DWARF Version 4 debugin <<
273 select DEBUG_INFO <<
274 depends on !CC_IS_CLANG || AS_IS_LLVM <<
275 help <<
276 Generate DWARF v4 debug info. This r <<
277 if using clang without clang's integ <<
278 <<
279 If you have consumers of DWARF debug <<
280 newer revisions of DWARF, you may wi <<
281 config select this. <<
282 <<
283 config DEBUG_INFO_DWARF5 <<
284 bool "Generate DWARF Version 5 debugin <<
285 select DEBUG_INFO <<
286 depends on !ARCH_HAS_BROKEN_DWARF5 <<
287 depends on !CC_IS_CLANG || AS_IS_LLVM <<
288 help <<
289 Generate DWARF v5 debug info. Requir <<
290 5.0+ accepts the -gdwarf-5 flag but <<
291 draft features until 7.0), and gdb 8 <<
292 <<
293 Changes to the structure of debug in <<
294 15-18% savings in resulting image an <<
295 compared to DWARF Version 4. DWARF V <<
296 extensions such as accelerators for <<
297 for fission (.dwo/.dwp) files. Users <<
298 config if they rely on tooling that <<
299 support DWARF Version 5. <<
300 <<
301 endchoice # "Debug information" <<
302 <<
303 if DEBUG_INFO <<
304 165
305 config DEBUG_INFO_REDUCED 166 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 167 bool "Reduce debugging information"
>> 168 depends on DEBUG_INFO
307 help 169 help
308 If you say Y here gcc is instructed 170 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 171 information for structure types. This means that tools that
310 need full debugging information (lik 172 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 173 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 174 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 175 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 176 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 177 Only works with newer gcc versions.
316 178
317 choice <<
318 prompt "Compressed Debug information" <<
319 help <<
320 Compress the resulting debug info. R <<
321 but requires that consumers are able <<
322 <<
323 If unsure, choose DEBUG_INFO_COMPRES <<
324 <<
325 config DEBUG_INFO_COMPRESSED_NONE <<
326 bool "Don't compress debug information <<
327 help <<
328 Don't compress debug info sections. <<
329 <<
330 config DEBUG_INFO_COMPRESSED_ZLIB <<
331 bool "Compress debugging information w <<
332 depends on $(cc-option,-gz=zlib) <<
333 depends on $(ld-option,--compress-debu <<
334 help <<
335 Compress the debug information using <<
336 5.0+, binutils 2.26+, and zlib. <<
337 <<
338 Users of dpkg-deb via scripts/packag <<
339 size of their debug .deb packages wi <<
340 debug info being compressed with zli <<
341 recompressed with a different compre <<
342 preferable to setting $KDEB_COMPRESS <<
343 larger. <<
344 <<
345 config DEBUG_INFO_COMPRESSED_ZSTD <<
346 bool "Compress debugging information w <<
347 depends on $(cc-option,-gz=zstd) <<
348 depends on $(ld-option,--compress-debu <<
349 help <<
350 Compress the debug information using <<
351 compression than zlib, for about the <<
352 toolchain support. Requires GCC 13. <<
353 zstd. <<
354 <<
355 endchoice # "Compressed Debug information" <<
356 <<
357 config DEBUG_INFO_SPLIT 179 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 180 bool "Produce split debuginfo in .dwo files"
359 depends on $(cc-option,-gsplit-dwarf) !! 181 depends on DEBUG_INFO
360 # RISC-V linker relaxation + -gsplit-d <<
361 # prior to 12.x: <<
362 # https://github.com/llvm/llvm-project <<
363 # https://gcc.gnu.org/bugzilla/show_bu <<
364 depends on !RISCV || GCC_VERSION >= 12 <<
365 help 182 help
366 Generate debug info into separate .d 183 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 184 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 185 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 186 files instead of multiple times in object files and executables.
370 In addition the debug information is 187 In addition the debug information is also compressed.
371 188
372 Requires recent gcc (4.7+) and recen 189 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 190 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 191 to know about the .dwo files and include them.
375 Incompatible with older versions of 192 Incompatible with older versions of ccache.
376 193
377 config DEBUG_INFO_BTF !! 194 config DEBUG_INFO_DWARF4
378 bool "Generate BTF type information" !! 195 bool "Generate dwarf4 debuginfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG !! 196 depends on DEBUG_INFO
380 depends on !GCC_PLUGIN_RANDSTRUCT || C <<
381 depends on BPF_SYSCALL <<
382 depends on !DEBUG_INFO_DWARF5 || PAHOL <<
383 # pahole uses elfutils, which does not <<
384 depends on !HEXAGON <<
385 help <<
386 Generate deduplicated BTF type infor <<
387 Turning this on expects presence of <<
388 DWARF type info into equivalent dedu <<
389 <<
390 config PAHOLE_HAS_SPLIT_BTF <<
391 def_bool PAHOLE_VERSION >= 119 <<
392 <<
393 config PAHOLE_HAS_BTF_TAG <<
394 def_bool PAHOLE_VERSION >= 123 <<
395 depends on CC_IS_CLANG <<
396 help <<
397 Decide whether pahole emits btf_tag <<
398 btf_decl_tag) or not. Currently only <<
399 these attributes, so make the config <<
400 <<
401 config PAHOLE_HAS_LANG_EXCLUDE <<
402 def_bool PAHOLE_VERSION >= 124 <<
403 help <<
404 Support for the --lang_exclude flag <<
405 compilation units from the supplied <<
406 omit Rust CUs which are not supporte <<
407 otherwise it would emit malformed ke <<
408 using DEBUG_INFO_BTF_MODULES. <<
409 <<
410 config DEBUG_INFO_BTF_MODULES <<
411 bool "Generate BTF type information fo <<
412 default y <<
413 depends on DEBUG_INFO_BTF && MODULES & <<
414 help 197 help
415 Generate compact split BTF type info !! 198 Generate dwarf4 debug info. This requires recent versions
416 !! 199 of gcc and gdb. It makes the debug information larger.
417 config MODULE_ALLOW_BTF_MISMATCH !! 200 But it significantly improves the success of resolving
418 bool "Allow loading modules with non-m !! 201 variables in gdb on optimized code.
419 depends on DEBUG_INFO_BTF_MODULES <<
420 help <<
421 For modules whose split BTF does not <<
422 BTF rather than refusing to load. Th <<
423 module BTF enabled is to reject modu <<
424 this option will still load module B <<
425 it when a mismatch is found. <<
426 202
427 config GDB_SCRIPTS 203 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 204 bool "Provide GDB scripts for kernel debugging"
>> 205 depends on DEBUG_INFO
429 help 206 help
430 This creates the required links to G 207 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 208 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 209 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 210 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 211 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 212 for further details.
436 213
437 endif # DEBUG_INFO !! 214 config ENABLE_MUST_CHECK
>> 215 bool "Enable __must_check logic"
>> 216 default y
>> 217 help
>> 218 Enable the __must_check logic in the kernel build. Disable this to
>> 219 suppress the "warning: ignoring return value of 'foo', declared with
>> 220 attribute warn_unused_result" messages.
438 221
439 config FRAME_WARN 222 config FRAME_WARN
440 int "Warn for stack frames larger than !! 223 int "Warn for stack frames larger than (needs gcc 4.4)"
441 range 0 8192 224 range 0 8192
442 default 0 if KMSAN !! 225 default 3072 if KASAN_EXTRA
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 226 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC !! 227 default 1280 if (!64BIT && PARISC)
445 default 1536 if (!64BIT && XTENSA) !! 228 default 1024 if (!64BIT && !PARISC)
446 default 1280 if KASAN && !64BIT <<
447 default 1024 if !64BIT <<
448 default 2048 if 64BIT 229 default 2048 if 64BIT
449 help 230 help
450 Tell the compiler to warn at build t !! 231 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 232 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 233 Setting it to 0 disables the warning.
>> 234 Requires gcc 4.4
453 235
454 config STRIP_ASM_SYMS 236 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 237 bool "Strip assembler-generated symbols during link"
456 default n 238 default n
457 help 239 help
458 Strip internal assembler-generated s 240 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 241 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 242 get_wchan() and suchlike.
461 243
462 config READABLE_ASM 244 config READABLE_ASM
463 bool "Generate readable assembler code !! 245 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL !! 246 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC !! 247 help
>> 248 Disable some compiler optimizations that tend to generate human unreadable
>> 249 assembler output. This may make the kernel slightly slower, but it helps
>> 250 to keep kernel developers who have to stare a lot at assembler listings
>> 251 sane.
>> 252
>> 253 config UNUSED_SYMBOLS
>> 254 bool "Enable unused/obsolete exported symbols"
>> 255 default y if X86
>> 256 help
>> 257 Unused but exported symbols make the kernel needlessly bigger. For
>> 258 that reason most of these unused exports will soon be removed. This
>> 259 option is provided temporarily to provide a transition period in case
>> 260 some external kernel module needs one of these symbols anyway. If you
>> 261 encounter such a case in your module, consider if you are actually
>> 262 using the right API. (rationale: since nobody in the kernel is using
>> 263 this in a module, there is a pretty good chance it's actually the
>> 264 wrong interface to use). If you really need the symbol, please send a
>> 265 mail to the linux kernel mailing list mentioning the symbol and why
>> 266 you really need it, and what the merge plan to the mainline kernel for
>> 267 your module is.
>> 268
>> 269 config PAGE_OWNER
>> 270 bool "Track page owner"
>> 271 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
>> 272 select DEBUG_FS
>> 273 select STACKTRACE
>> 274 select STACKDEPOT
>> 275 select PAGE_EXTENSION
466 help 276 help
467 Disable some compiler optimizations !! 277 This keeps track of what call chain is the owner of a page, may
468 assembler output. This may make the !! 278 help to find bare alloc_page(s) leaks. Even if you include this
469 to keep kernel developers who have t !! 279 feature on your build, it is disabled in default. You should pass
470 sane. !! 280 "page_owner=on" to boot parameter in order to enable it. Eats
>> 281 a fair amount of memory if enabled. See tools/vm/page_owner_sort.c
>> 282 for user-space helper.
471 283
472 config HEADERS_INSTALL !! 284 If unsure, say N.
473 bool "Install uapi headers to usr/incl !! 285
>> 286 config DEBUG_FS
>> 287 bool "Debug Filesystem"
>> 288 help
>> 289 debugfs is a virtual file system that kernel developers use to put
>> 290 debugging files into. Enable this option to be able to read and
>> 291 write to these files.
>> 292
>> 293 For detailed documentation on the debugfs API, see
>> 294 Documentation/filesystems/.
>> 295
>> 296 If unsure, say N.
>> 297
>> 298 config HEADERS_CHECK
>> 299 bool "Run 'make headers_check' when building vmlinux"
474 depends on !UML 300 depends on !UML
475 help 301 help
476 This option will install uapi header !! 302 This option will extract the user-visible kernel headers whenever
477 into the usr/include directory for u !! 303 building the kernel, and will run basic sanity checks on them to
478 This is unneeded for building the ke !! 304 ensure that exported files do not attempt to include files which
479 user-space program samples. It is al !! 305 were not exported, etc.
480 as uapi header sanity checks. !! 306
>> 307 If you're making modifications to header files which are
>> 308 relevant for userspace, say 'Y', and check the headers
>> 309 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
>> 310 your build tree), to make sure they're suitable.
481 311
482 config DEBUG_SECTION_MISMATCH 312 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 313 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 314 help
486 The section mismatch analysis checks 315 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 316 references from one section to another section.
488 During linktime or runtime, some sec 317 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 318 any use of code/data previously in these sections would
490 most likely result in an oops. 319 most likely result in an oops.
491 In the code, functions and variables 320 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 321 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 322 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 323 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 324 kernel build, and enabling this option causes the following
496 additional step to occur: !! 325 additional steps to occur:
497 - Add the option -fno-inline-functio 326 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 327 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 328 function, we would lose the section information and thus
500 the analysis would not catch the i 329 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 330 This option tells gcc to inline less (but it does result in
502 a larger kernel). 331 a larger kernel).
>> 332 - Run the section mismatch analysis for each module/built-in.a file.
>> 333 When we run the section mismatch analysis on vmlinux.o, we
>> 334 lose valuable information about where the mismatch was
>> 335 introduced.
>> 336 Running the analysis for each module/built-in.a file
>> 337 tells where the mismatch happens much closer to the
>> 338 source. The drawback is that the same mismatch is
>> 339 reported at least twice.
>> 340 - Enable verbose reporting from modpost in order to help resolve
>> 341 the section mismatches that are reported.
503 342
504 config SECTION_MISMATCH_WARN_ONLY 343 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 344 bool "Make section mismatch errors non-fatal"
506 default y 345 default y
507 help 346 help
508 If you say N here, the build process 347 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 348 section mismatch, instead of just throwing warnings.
510 349
511 If unsure, say Y. 350 If unsure, say Y.
512 351
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B <<
514 bool "Force all function address 64B a <<
515 depends on EXPERT && (X86_64 || ARM64 <<
516 select FUNCTION_ALIGNMENT_64B <<
517 help <<
518 There are cases that a commit from o <<
519 address alignment of other domains, <<
520 bump (regression or improvement). En <<
521 verify if the bump is caused by func <<
522 it will slightly increase the kernel <<
523 <<
524 It is mainly for debug and performan <<
525 <<
526 # 352 #
527 # Select this config option from the architect 353 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 354 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 355 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 356 #
531 config ARCH_WANT_FRAME_POINTERS 357 config ARCH_WANT_FRAME_POINTERS
532 bool 358 bool
533 359
534 config FRAME_POINTER 360 config FRAME_POINTER
535 bool "Compile the kernel with frame po 361 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 362 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 363 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 364 help
539 If you say Y here the resulting kern 365 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 366 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 367 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 368
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 369 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 370 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 371 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 372 default n
551 help 373 help
552 Validate frame pointer rules at comp !! 374 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 375 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 376 that runtime stack traces are more reliable.
554 377
555 For more information, see !! 378 This is also a prerequisite for generation of ORC unwind data, which
556 tools/objtool/Documentation/objtool. !! 379 is needed for CONFIG_UNWINDER_ORC.
557 380
558 config NOINSTR_VALIDATION !! 381 For more information, see
559 bool !! 382 tools/objtool/Documentation/stack-validation.txt.
560 depends on HAVE_NOINSTR_VALIDATION && <<
561 select OBJTOOL <<
562 default y <<
563 <<
564 config VMLINUX_MAP <<
565 bool "Generate vmlinux.map file when l <<
566 depends on EXPERT <<
567 help <<
568 Selecting this option will pass "-Ma <<
569 when linking vmlinux. That file can <<
570 and debugging magic section games, a <<
571 pieces of code get eliminated with <<
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION <<
573 383
574 config DEBUG_FORCE_WEAK_PER_CPU 384 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 385 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 386 depends on DEBUG_KERNEL
577 help 387 help
578 s390 and alpha require percpu variab 388 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 389 defined weak to work around addressing range issue which
580 puts the following two restrictions 390 puts the following two restrictions on percpu variable
581 definitions. 391 definitions.
582 392
583 1. percpu symbols must be unique whe 393 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 394 2. percpu variables can't be defined inside a function
585 395
586 To ensure that generic code follows 396 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 397 option forces all percpu variables to be defined as weak.
588 398
589 endmenu # "Compiler options" 399 endmenu # "Compiler options"
590 400
591 menu "Generic Kernel Debugging Instruments" <<
592 <<
593 config MAGIC_SYSRQ 401 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 402 bool "Magic SysRq key"
595 depends on !UML 403 depends on !UML
596 help 404 help
597 If you say Y here, you will have som 405 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 406 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 407 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 408 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 409 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 410 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 411 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 412 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 413 Don't say Y unless you really know what this hack does.
606 414
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 415 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 416 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 417 depends on MAGIC_SYSRQ
610 default 0x1 418 default 0x1
611 help 419 help
612 Specifies which SysRq key functions 420 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 421 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 422 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 423
616 config MAGIC_SYSRQ_SERIAL 424 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 425 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 426 depends on MAGIC_SYSRQ
619 default y 427 default y
620 help 428 help
621 Many embedded boards have a disconne 429 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 430 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 431 This option allows you to decide whether you want to enable the
624 magic SysRq key. 432 magic SysRq key.
625 433
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE !! 434 config DEBUG_KERNEL
627 string "Char sequence that enables mag !! 435 bool "Kernel debugging"
628 depends on MAGIC_SYSRQ_SERIAL <<
629 default "" <<
630 help <<
631 Specifies a sequence of characters t <<
632 SysRq on a serial console. <<
633 <<
634 If unsure, leave an empty string and <<
635 <<
636 config DEBUG_FS <<
637 bool "Debug Filesystem" <<
638 help <<
639 debugfs is a virtual file system tha <<
640 debugging files into. Enable this o <<
641 write to these files. <<
642 <<
643 For detailed documentation on the de <<
644 Documentation/filesystems/. <<
645 <<
646 If unsure, say N. <<
647 <<
648 choice <<
649 prompt "Debugfs default access" <<
650 depends on DEBUG_FS <<
651 default DEBUG_FS_ALLOW_ALL <<
652 help <<
653 This selects the default access rest <<
654 It can be overridden with kernel com <<
655 debugfs=[on,no-mount,off]. The restr <<
656 and filesystem registration. <<
657 <<
658 config DEBUG_FS_ALLOW_ALL <<
659 bool "Access normal" <<
660 help <<
661 No restrictions apply. Both API and <<
662 is on. This is the normal default op <<
663 <<
664 config DEBUG_FS_DISALLOW_MOUNT <<
665 bool "Do not register debugfs as files <<
666 help <<
667 The API is open but filesystem is no <<
668 their work and read with debug tools <<
669 debugfs filesystem. <<
670 <<
671 config DEBUG_FS_ALLOW_NONE <<
672 bool "No access" <<
673 help 436 help
674 Access is off. Clients get -PERM whe !! 437 Say Y here if you are developing drivers or trying to debug and
675 debugfs tree and debugfs is not regi !! 438 identify kernel problems.
676 Client can then back-off or continue <<
677 <<
678 endchoice <<
679 <<
680 source "lib/Kconfig.kgdb" <<
681 source "lib/Kconfig.ubsan" <<
682 source "lib/Kconfig.kcsan" <<
683 <<
684 endmenu <<
685 <<
686 menu "Networking Debugging" <<
687 <<
688 source "net/Kconfig.debug" <<
689 <<
690 endmenu # "Networking Debugging" <<
691 439
692 menu "Memory Debugging" 440 menu "Memory Debugging"
693 441
694 source "mm/Kconfig.debug" !! 442 source mm/Kconfig.debug
695 443
696 config DEBUG_OBJECTS 444 config DEBUG_OBJECTS
697 bool "Debug object operations" 445 bool "Debug object operations"
698 depends on DEBUG_KERNEL 446 depends on DEBUG_KERNEL
699 help 447 help
700 If you say Y here, additional code w 448 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 449 kernel to track the life time of various objects and validate
702 the operations on those objects. 450 the operations on those objects.
703 451
704 config DEBUG_OBJECTS_SELFTEST 452 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 453 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 454 depends on DEBUG_OBJECTS
707 help 455 help
708 This enables the selftest of the obj 456 This enables the selftest of the object debug code.
709 457
710 config DEBUG_OBJECTS_FREE 458 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 459 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 460 depends on DEBUG_OBJECTS
713 help 461 help
714 This enables checks whether a k/v fr 462 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 463 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 464 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 465 much slower.
718 466
719 config DEBUG_OBJECTS_TIMERS 467 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 468 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 469 depends on DEBUG_OBJECTS
722 help 470 help
723 If you say Y here, additional code w 471 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 472 timer routines to track the life time of timer objects and
725 validate the timer operations. 473 validate the timer operations.
726 474
727 config DEBUG_OBJECTS_WORK 475 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 476 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 477 depends on DEBUG_OBJECTS
730 help 478 help
731 If you say Y here, additional code w 479 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 480 work queue routines to track the life time of work objects and
733 validate the work operations. 481 validate the work operations.
734 482
735 config DEBUG_OBJECTS_RCU_HEAD 483 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 484 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 485 depends on DEBUG_OBJECTS
738 help 486 help
739 Enable this to turn on debugging of 487 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 488
741 config DEBUG_OBJECTS_PERCPU_COUNTER 489 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 490 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 491 depends on DEBUG_OBJECTS
744 help 492 help
745 If you say Y here, additional code w 493 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 494 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 495 objects and validate the percpu counter operations.
748 496
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 497 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 498 int "debug_objects bootup default value (0-1)"
751 range 0 1 !! 499 range 0 1
752 default "1" !! 500 default "1"
753 depends on DEBUG_OBJECTS !! 501 depends on DEBUG_OBJECTS
>> 502 help
>> 503 Debug objects boot parameter default value
>> 504
>> 505 config DEBUG_SLAB
>> 506 bool "Debug slab memory allocations"
>> 507 depends on DEBUG_KERNEL && SLAB
>> 508 help
>> 509 Say Y here to have the kernel do limited verification on memory
>> 510 allocation as well as poisoning memory on free to catch use of freed
>> 511 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 512
>> 513 config DEBUG_SLAB_LEAK
>> 514 bool "Memory leak debugging"
>> 515 depends on DEBUG_SLAB
>> 516
>> 517 config SLUB_DEBUG_ON
>> 518 bool "SLUB debugging on by default"
>> 519 depends on SLUB && SLUB_DEBUG
>> 520 default n
>> 521 help
>> 522 Boot with debugging on by default. SLUB boots by default with
>> 523 the runtime debug capabilities switched off. Enabling this is
>> 524 equivalent to specifying the "slub_debug" parameter on boot.
>> 525 There is no support for more fine grained debug control like
>> 526 possible with slub_debug=xxx. SLUB debugging may be switched
>> 527 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 528 "slub_debug=-".
>> 529
>> 530 config SLUB_STATS
>> 531 default n
>> 532 bool "Enable SLUB performance statistics"
>> 533 depends on SLUB && SYSFS
>> 534 help
>> 535 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 536 order find ways to optimize the allocator. This should never be
>> 537 enabled for production use since keeping statistics slows down
>> 538 the allocator by a few percentage points. The slabinfo command
>> 539 supports the determination of the most active slabs to figure
>> 540 out which slabs are relevant to a particular load.
>> 541 Try running: slabinfo -DA
>> 542
>> 543 config HAVE_DEBUG_KMEMLEAK
>> 544 bool
>> 545
>> 546 config DEBUG_KMEMLEAK
>> 547 bool "Kernel memory leak detector"
>> 548 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 549 select DEBUG_FS
>> 550 select STACKTRACE if STACKTRACE_SUPPORT
>> 551 select KALLSYMS
>> 552 select CRC32
754 help 553 help
755 Debug objects boot parameter default !! 554 Say Y here if you want to enable the memory leak
>> 555 detector. The memory allocation/freeing is traced in a way
>> 556 similar to the Boehm's conservative garbage collector, the
>> 557 difference being that the orphan objects are not freed but
>> 558 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 559 feature will introduce an overhead to memory
>> 560 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 561 details.
756 562
757 config SHRINKER_DEBUG !! 563 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
758 bool "Enable shrinker debugging suppor !! 564 of finding leaks due to the slab objects poisoning.
759 depends on DEBUG_FS !! 565
>> 566 In order to access the kmemleak file, debugfs needs to be
>> 567 mounted (usually at /sys/kernel/debug).
>> 568
>> 569 config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
>> 570 int "Maximum kmemleak early log entries"
>> 571 depends on DEBUG_KMEMLEAK
>> 572 range 200 40000
>> 573 default 400
760 help 574 help
761 Say Y to enable the shrinker debugfs !! 575 Kmemleak must track all the memory allocations to avoid
762 visibility into the kernel memory sh !! 576 reporting false positives. Since memory may be allocated or
763 Disable it to avoid an extra memory !! 577 freed before kmemleak is initialised, an early log buffer is
>> 578 used to store these actions. If kmemleak reports "early log
>> 579 buffer exceeded", please increase this value.
764 580
765 config DEBUG_STACK_USAGE !! 581 config DEBUG_KMEMLEAK_TEST
766 bool "Stack utilization instrumentatio !! 582 tristate "Simple test for the kernel memory leak detector"
767 depends on DEBUG_KERNEL !! 583 depends on DEBUG_KMEMLEAK && m
768 help 584 help
769 Enables the display of the minimum a !! 585 This option enables a module that explicitly leaks memory.
770 task has ever had available in the s <<
771 Also emits a message to dmesg when a <<
772 used more stack space than previousl <<
773 586
774 This option will slow down process c !! 587 If unsure, say N.
775 588
776 config SCHED_STACK_END_CHECK !! 589 config DEBUG_KMEMLEAK_DEFAULT_OFF
777 bool "Detect stack corruption on calls !! 590 bool "Default kmemleak to off"
778 depends on DEBUG_KERNEL !! 591 depends on DEBUG_KMEMLEAK
779 default n <<
780 help 592 help
781 This option checks for a stack overr !! 593 Say Y here to disable kmemleak by default. It can then be enabled
782 If the stack end location is found t !! 594 on the command line via kmemleak=on.
783 the content of the corrupted region <<
784 This is to ensure no erroneous behav <<
785 data corruption or a sporadic crash <<
786 is examined. The runtime overhead in <<
787 595
788 config ARCH_HAS_DEBUG_VM_PGTABLE !! 596 config DEBUG_STACK_USAGE
789 bool !! 597 bool "Stack utilization instrumentation"
>> 598 depends on DEBUG_KERNEL && !IA64
790 help 599 help
791 An architecture should select this w !! 600 Enables the display of the minimum amount of free stack which each
792 build and run DEBUG_VM_PGTABLE. !! 601 task has ever had available in the sysrq-T and sysrq-P debug output.
793 602
794 config DEBUG_VM_IRQSOFF !! 603 This option will slow down process creation somewhat.
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 604
797 config DEBUG_VM 605 config DEBUG_VM
798 bool "Debug VM" 606 bool "Debug VM"
799 depends on DEBUG_KERNEL 607 depends on DEBUG_KERNEL
800 help 608 help
801 Enable this to turn on extended chec 609 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. !! 610 that may impact performance.
803 611
804 If unsure, say N. 612 If unsure, say N.
805 613
806 config DEBUG_VM_SHOOT_LAZIES !! 614 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 615 bool "Debug VMA caching"
808 depends on DEBUG_VM 616 depends on DEBUG_VM
809 depends on MMU_LAZY_TLB_SHOOTDOWN <<
810 help 617 help
811 Enable additional IPIs that ensure l !! 618 Enable this to turn on VMA caching debug information. Doing so
812 before the mm is freed. !! 619 can cause significant overhead, so only enable it in non-production
813 !! 620 environments.
814 If unsure, say N. <<
815 <<
816 config DEBUG_VM_MAPLE_TREE <<
817 bool "Debug VM maple trees" <<
818 depends on DEBUG_VM <<
819 select DEBUG_MAPLE_TREE <<
820 help <<
821 Enable VM maple tree debugging infor <<
822 621
823 If unsure, say N. 622 If unsure, say N.
824 623
825 config DEBUG_VM_RB 624 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 625 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 626 depends on DEBUG_VM
828 help 627 help
829 Enable VM red-black tree debugging i 628 Enable VM red-black tree debugging information and extra validations.
830 629
831 If unsure, say N. 630 If unsure, say N.
832 631
833 config DEBUG_VM_PGFLAGS 632 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 633 bool "Debug page-flags operations"
835 depends on DEBUG_VM 634 depends on DEBUG_VM
836 help 635 help
837 Enables extra validation on page fla 636 Enables extra validation on page flags operations.
838 637
839 If unsure, say N. 638 If unsure, say N.
840 639
841 config DEBUG_VM_PGTABLE <<
842 bool "Debug arch page table for semant <<
843 depends on MMU <<
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE <<
845 default y if DEBUG_VM <<
846 help <<
847 This option provides a debug method <<
848 architecture page table helper funct <<
849 verifying if they comply with expect <<
850 will help architecture code in makin <<
851 new additions of these helpers still <<
852 semantics of the generic MM. Platfor <<
853 this through ARCH_HAS_DEBUG_VM_PGTAB <<
854 <<
855 If unsure, say N. <<
856 <<
857 config ARCH_HAS_DEBUG_VIRTUAL 640 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 641 bool
859 642
860 config DEBUG_VIRTUAL 643 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 644 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 645 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 646 help
864 Enable some costly sanity checks in 647 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 648 catch mistakes with virt_to_page() and friends.
866 649
867 If unsure, say N. 650 If unsure, say N.
868 651
869 config DEBUG_NOMMU_REGIONS 652 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 653 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 654 depends on DEBUG_KERNEL && !MMU
872 help 655 help
873 This option causes the global tree o 656 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 657 regions to be regularly checked for invalid topology.
875 658
876 config DEBUG_MEMORY_INIT 659 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 660 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 661 default !EXPERT
879 help 662 help
880 Enable this for additional checks du 663 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 664 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 665 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 666 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 667 on the mminit_loglevel= command-line option.
885 668
886 If unsure, say Y 669 If unsure, say Y
887 670
888 config MEMORY_NOTIFIER_ERROR_INJECT 671 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 672 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 673 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 674 help
892 This option provides the ability to 675 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 676 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 677 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 678
896 If the notifier call chain should be 679 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 680 notified, write the error code to "actions/<notifier event>/error".
898 681
899 Example: Inject memory hotplug offli 682 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 683
901 # cd /sys/kernel/debug/notifier-erro 684 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 685 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 686 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 687 bash: echo: write error: Cannot allocate memory
905 688
906 To compile this code as a module, ch 689 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 690 be called memory-notifier-error-inject.
908 691
909 If unsure, say N. 692 If unsure, say N.
910 693
911 config DEBUG_PER_CPU_MAPS 694 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 695 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 696 depends on DEBUG_KERNEL
914 depends on SMP 697 depends on SMP
915 help 698 help
916 Say Y to verify that the per_cpu map 699 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 700 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 701 and decreases performance.
919 702
920 Say N if unsure. 703 Say N if unsure.
921 704
922 config DEBUG_KMAP_LOCAL <<
923 bool "Debug kmap_local temporary mappi <<
924 depends on DEBUG_KERNEL && KMAP_LOCAL <<
925 help <<
926 This option enables additional error <<
927 infrastructure. Disable for product <<
928 <<
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP <<
930 bool <<
931 <<
932 config DEBUG_KMAP_LOCAL_FORCE_MAP <<
933 bool "Enforce kmap_local temporary map <<
934 depends on DEBUG_KERNEL && ARCH_SUPPOR <<
935 select KMAP_LOCAL <<
936 select DEBUG_KMAP_LOCAL <<
937 help <<
938 This option enforces temporary mappi <<
939 mechanism for non-highmem pages and <<
940 Disable this for production systems! <<
941 <<
942 config DEBUG_HIGHMEM 705 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 706 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 707 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A <<
946 select DEBUG_KMAP_LOCAL <<
947 help 708 help
948 This option enables additional error 709 This option enables additional error checking for high memory
949 systems. Disable for production sys 710 systems. Disable for production systems.
950 711
951 config HAVE_DEBUG_STACKOVERFLOW 712 config HAVE_DEBUG_STACKOVERFLOW
952 bool 713 bool
953 714
954 config DEBUG_STACKOVERFLOW 715 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 716 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 717 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help !! 718 ---help---
958 Say Y here if you want to check for 719 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 720 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 721 option will show detailed messages if free stack space drops
961 below a certain limit. 722 below a certain limit.
962 723
963 These kinds of bugs usually occur wh 724 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 725 kernel get too deep, especially when interrupts are
965 involved. 726 involved.
966 727
967 Use this in cases where you see appa 728 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 729 corruption, especially if it appears in 'struct thread_info'
969 730
970 If in doubt, say "N". 731 If in doubt, say "N".
971 732
972 config CODE_TAGGING <<
973 bool <<
974 select KALLSYMS <<
975 <<
976 config MEM_ALLOC_PROFILING <<
977 bool "Enable memory allocation profili <<
978 default n <<
979 depends on PROC_FS <<
980 depends on !DEBUG_FORCE_WEAK_PER_CPU <<
981 select CODE_TAGGING <<
982 select PAGE_EXTENSION <<
983 select SLAB_OBJ_EXT <<
984 help <<
985 Track allocation source code and rec <<
986 initiated at that code location. The <<
987 memory leaks with a low performance <<
988 <<
989 config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT <<
990 bool "Enable memory allocation profili <<
991 default y <<
992 depends on MEM_ALLOC_PROFILING <<
993 <<
994 config MEM_ALLOC_PROFILING_DEBUG <<
995 bool "Memory allocation profiler debug <<
996 default n <<
997 depends on MEM_ALLOC_PROFILING <<
998 select MEM_ALLOC_PROFILING_ENABLED_BY_ <<
999 help <<
1000 Adds warnings with helpful error me <<
1001 profiling. <<
1002 <<
1003 source "lib/Kconfig.kasan" 733 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" <<
1005 source "lib/Kconfig.kmsan" <<
1006 734
1007 endmenu # "Memory Debugging" 735 endmenu # "Memory Debugging"
1008 736
1009 config DEBUG_SHIRQ !! 737 config ARCH_HAS_KCOV
1010 bool "Debug shared IRQ handlers" !! 738 bool
1011 depends on DEBUG_KERNEL <<
1012 help 739 help
1013 Enable this to generate a spurious !! 740 KCOV does not have any arch-specific code, but currently it is enabled
1014 interrupt handler is deregistered ( !! 741 only for x86_64. KCOV requires testing on other archs, and most likely
1015 is currently disabled). Drivers nee !! 742 disabling of instrumentation for some early boot code.
1016 don't and need to be caught. <<
1017 743
1018 menu "Debug Oops, Lockups and Hangs" !! 744 config CC_HAS_SANCOV_TRACE_PC
>> 745 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1019 746
1020 config PANIC_ON_OOPS !! 747 config KCOV
1021 bool "Panic on Oops" !! 748 bool "Code coverage for fuzzing"
>> 749 depends on ARCH_HAS_KCOV
>> 750 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
>> 751 select DEBUG_FS
>> 752 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1022 help 753 help
1023 Say Y here to enable the kernel to !! 754 KCOV exposes kernel code coverage information in a form suitable
1024 has the same effect as setting oops !! 755 for coverage-guided fuzzing (randomized testing).
1025 line. <<
1026 756
1027 This feature is useful to ensure th !! 757 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1028 anything erroneous after an oops wh !! 758 different machines and across reboots. If you need stable PC values,
1029 corruption or other issues. !! 759 disable RANDOMIZE_BASE.
1030 760
1031 Say N if unsure. !! 761 For more details, see Documentation/dev-tools/kcov.rst.
1032 762
1033 config PANIC_ON_OOPS_VALUE !! 763 config KCOV_ENABLE_COMPARISONS
1034 int !! 764 bool "Enable comparison operands collection by KCOV"
1035 range 0 1 !! 765 depends on KCOV
1036 default 0 if !PANIC_ON_OOPS !! 766 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1037 default 1 if PANIC_ON_OOPS !! 767 help
>> 768 KCOV also exposes operands of every comparison in the instrumented
>> 769 code along with operand sizes and PCs of the comparison instructions.
>> 770 These operands can be used by fuzzing engines to improve the quality
>> 771 of fuzzing coverage.
1038 772
1039 config PANIC_TIMEOUT !! 773 config KCOV_INSTRUMENT_ALL
1040 int "panic timeout" !! 774 bool "Instrument all code by default"
1041 default 0 !! 775 depends on KCOV
>> 776 default y
1042 help 777 help
1043 Set the timeout value (in seconds) !! 778 If you are doing generic system call fuzzing (like e.g. syzkaller),
1044 the kernel panics. If n = 0, then w !! 779 then you will want to instrument the whole kernel and you should
1045 value n > 0 will wait n seconds bef !! 780 say y here. If you are doing more targeted fuzzing (like e.g.
1046 value n < 0 will reboot immediately !! 781 filesystem fuzzing with AFL) then you will want to enable coverage
1047 with the kernel command line option !! 782 for more specific subsets of files, and should say n here.
1048 /proc/sys/kernel/panic. !! 783
>> 784 config DEBUG_SHIRQ
>> 785 bool "Debug shared IRQ handlers"
>> 786 depends on DEBUG_KERNEL
>> 787 help
>> 788 Enable this to generate a spurious interrupt as soon as a shared
>> 789 interrupt handler is registered, and just before one is deregistered.
>> 790 Drivers ought to be able to handle interrupts coming in at those
>> 791 points; some don't and need to be caught.
>> 792
>> 793 menu "Debug Lockups and Hangs"
1049 794
1050 config LOCKUP_DETECTOR 795 config LOCKUP_DETECTOR
1051 bool 796 bool
1052 797
1053 config SOFTLOCKUP_DETECTOR 798 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 799 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 800 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 801 select LOCKUP_DETECTOR
1057 help 802 help
1058 Say Y here to enable the kernel to 803 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 804 soft lockups.
1060 805
1061 Softlockups are bugs that cause the 806 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 807 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 808 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 809 detection and the system will stay locked up.
1065 810
1066 config SOFTLOCKUP_DETECTOR_INTR_STORM <<
1067 bool "Detect Interrupt Storm in Soft <<
1068 depends on SOFTLOCKUP_DETECTOR && IRQ <<
1069 select GENERIC_IRQ_STAT_SNAPSHOT <<
1070 default y if NR_CPUS <= 128 <<
1071 help <<
1072 Say Y here to enable the kernel to <<
1073 during "soft lockups". <<
1074 <<
1075 "soft lockups" can be caused by a v <<
1076 caused by an interrupt storm, then <<
1077 be on the callstack. To detect this <<
1078 the CPU stats and the interrupt cou <<
1079 <<
1080 config BOOTPARAM_SOFTLOCKUP_PANIC 811 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 812 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 813 depends on SOFTLOCKUP_DETECTOR
1083 help 814 help
1084 Say Y here to enable the kernel to 815 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 816 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 817 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 818 sysctl), without giving other tasks a chance to run.
1088 819
1089 The panic can be used in combinatio 820 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 821 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 822 lockup has been detected. This feature is useful for
1092 high-availability systems that have 823 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 824 where a lockup must be resolved ASAP.
1094 825
1095 Say N if unsure. 826 Say N if unsure.
1096 827
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 828 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 829 int
>> 830 depends on SOFTLOCKUP_DETECTOR
>> 831 range 0 1
>> 832 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 833 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 834
>> 835 config HARDLOCKUP_DETECTOR_PERF
1098 bool 836 bool
1099 depends on SMP !! 837 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 838
1102 # 839 #
1103 # Global switch whether to build a hardlockup !! 840 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 841 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 842 #
1107 # s390: it reported many false positive !! 843 config HARDLOCKUP_CHECK_TIMESTAMP
>> 844 bool
>> 845
1108 # 846 #
1109 # sparc64: has a custom implementation !! 847 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 848 # lockup detector rather than the perf based detector.
1111 # 849 #
1112 config HARDLOCKUP_DETECTOR 850 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 851 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 852 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 853 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
1116 imply HARDLOCKUP_DETECTOR_PERF <<
1117 imply HARDLOCKUP_DETECTOR_BUDDY <<
1118 imply HARDLOCKUP_DETECTOR_ARCH <<
1119 select LOCKUP_DETECTOR 854 select LOCKUP_DETECTOR
1120 !! 855 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
>> 856 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121 help 857 help
1122 Say Y here to enable the kernel to 858 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 859 hard lockups.
1124 860
1125 Hardlockups are bugs that cause the 861 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 862 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 863 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 864 and the system will stay locked up.
1129 865
1130 # <<
1131 # Note that arch-specific variants are always <<
1132 # <<
1133 config HARDLOCKUP_DETECTOR_PREFER_BUDDY <<
1134 bool "Prefer the buddy CPU hardlockup <<
1135 depends on HARDLOCKUP_DETECTOR <<
1136 depends on HAVE_HARDLOCKUP_DETECTOR_P <<
1137 depends on !HAVE_HARDLOCKUP_DETECTOR_ <<
1138 help <<
1139 Say Y here to prefer the buddy hard <<
1140 <<
1141 With the buddy detector, each CPU u <<
1142 to check that the next CPU is proce <<
1143 verifying that a counter is increas <<
1144 <<
1145 This hardlockup detector is useful <<
1146 an arch-specific hardlockup detecto <<
1147 for the hardlockup detector are bet <<
1148 <<
1149 config HARDLOCKUP_DETECTOR_PERF <<
1150 bool <<
1151 depends on HARDLOCKUP_DETECTOR <<
1152 depends on HAVE_HARDLOCKUP_DETECTOR_P <<
1153 depends on !HAVE_HARDLOCKUP_DETECTOR_ <<
1154 select HARDLOCKUP_DETECTOR_COUNTS_HRT <<
1155 <<
1156 config HARDLOCKUP_DETECTOR_BUDDY <<
1157 bool <<
1158 depends on HARDLOCKUP_DETECTOR <<
1159 depends on HAVE_HARDLOCKUP_DETECTOR_B <<
1160 depends on !HAVE_HARDLOCKUP_DETECTOR_ <<
1161 depends on !HAVE_HARDLOCKUP_DETECTOR_ <<
1162 select HARDLOCKUP_DETECTOR_COUNTS_HRT <<
1163 <<
1164 config HARDLOCKUP_DETECTOR_ARCH <<
1165 bool <<
1166 depends on HARDLOCKUP_DETECTOR <<
1167 depends on HAVE_HARDLOCKUP_DETECTOR_A <<
1168 help <<
1169 The arch-specific implementation of <<
1170 be used. <<
1171 <<
1172 # <<
1173 # Both the "perf" and "buddy" hardlockup dete <<
1174 # interrupts. This config enables functions m <<
1175 # <<
1176 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER <<
1177 bool <<
1178 select SOFTLOCKUP_DETECTOR <<
1179 <<
1180 # <<
1181 # Enables a timestamp based low pass filter t <<
1182 # hard lockup detection which runs too fast d <<
1183 # <<
1184 config HARDLOCKUP_CHECK_TIMESTAMP <<
1185 bool <<
1186 <<
1187 config BOOTPARAM_HARDLOCKUP_PANIC 866 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 867 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 868 depends on HARDLOCKUP_DETECTOR
1190 help 869 help
1191 Say Y here to enable the kernel to 870 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 871 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 872 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 873 using the watchdog_thresh sysctl).
1195 874
1196 Say N if unsure. 875 Say N if unsure.
1197 876
>> 877 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 878 int
>> 879 depends on HARDLOCKUP_DETECTOR
>> 880 range 0 1
>> 881 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 882 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 883
1198 config DETECT_HUNG_TASK 884 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 885 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 886 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 887 default SOFTLOCKUP_DETECTOR
1202 help 888 help
1203 Say Y here to enable the kernel to 889 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 890 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 891 uninterruptible "D" state indefinitely.
1206 892
1207 When a hung task is detected, the k 893 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 894 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 895 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 896 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 897 feature has negligible overhead.
1212 898
1213 config DEFAULT_HUNG_TASK_TIMEOUT 899 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 900 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 901 depends on DETECT_HUNG_TASK
1216 default 120 902 default 120
1217 help 903 help
1218 This option controls the default ti 904 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 905 to determine when a task has become non-responsive and should
1220 be considered hung. 906 be considered hung.
1221 907
1222 It can be adjusted at runtime via t 908 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 909 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 910 /proc/sys/kernel/hung_task_timeout_secs.
1225 911
1226 A timeout of 0 disables the check. 912 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 913 Keeping the default should be fine in most cases.
1228 914
1229 config BOOTPARAM_HUNG_TASK_PANIC 915 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 916 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 917 depends on DETECT_HUNG_TASK
1232 help 918 help
1233 Say Y here to enable the kernel to 919 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 920 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 921 in uninterruptible "D" state.
1236 922
1237 The panic can be used in combinatio 923 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 924 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 925 hung task has been detected. This feature is useful for
1240 high-availability systems that have 926 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 927 where a hung tasks must be resolved ASAP.
1242 928
1243 Say N if unsure. 929 Say N if unsure.
1244 930
>> 931 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 932 int
>> 933 depends on DETECT_HUNG_TASK
>> 934 range 0 1
>> 935 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 936 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 937
1245 config WQ_WATCHDOG 938 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 939 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 940 depends on DEBUG_KERNEL
1248 help 941 help
1249 Say Y here to enable stall detectio 942 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 943 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 944 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 945 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 946 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 947 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 948
1256 config WQ_CPU_INTENSIVE_REPORT !! 949 endmenu # "Debug lockups and hangs"
1257 bool "Report per-cpu work items which <<
1258 depends on DEBUG_KERNEL <<
1259 help <<
1260 Say Y here to enable reporting of c <<
1261 items that hog CPUs for longer than <<
1262 workqueue.cpu_intensive_thresh_us. <<
1263 detects and excludes them from conc <<
1264 them from stalling other per-cpu wo <<
1265 triggering may not necessarily indi <<
1266 triggering likely indicates that th <<
1267 to use an unbound workqueue. <<
1268 950
1269 config TEST_LOCKUP !! 951 config PANIC_ON_OOPS
1270 tristate "Test module to generate loc !! 952 bool "Panic on Oops"
1271 depends on m <<
1272 help 953 help
1273 This builds the "test_lockup" modul !! 954 Say Y here to enable the kernel to panic when it oopses. This
1274 that watchdogs and lockup detectors !! 955 has the same effect as setting oops=panic on the kernel command
>> 956 line.
1275 957
1276 Depending on module parameters it c !! 958 This feature is useful to ensure that the kernel does not do
1277 lockup, "hung task", or locking arb !! 959 anything erroneous after an oops which could result in data
1278 Also it could generate series of lo !! 960 corruption or other issues.
1279 961
1280 If unsure, say N. !! 962 Say N if unsure.
1281 963
1282 endmenu # "Debug lockups and hangs" !! 964 config PANIC_ON_OOPS_VALUE
>> 965 int
>> 966 range 0 1
>> 967 default 0 if !PANIC_ON_OOPS
>> 968 default 1 if PANIC_ON_OOPS
1283 969
1284 menu "Scheduler Debugging" !! 970 config PANIC_TIMEOUT
>> 971 int "panic timeout"
>> 972 default 0
>> 973 help
>> 974 Set the timeout value (in seconds) until a reboot occurs when the
>> 975 the kernel panics. If n = 0, then we wait forever. A timeout
>> 976 value n > 0 will wait n seconds before rebooting, while a timeout
>> 977 value n < 0 will reboot immediately.
1285 978
1286 config SCHED_DEBUG 979 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 980 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 981 depends on DEBUG_KERNEL && PROC_FS
1289 default y 982 default y
1290 help 983 help
1291 If you say Y here, the /sys/kernel/ !! 984 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 985 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 986 option is minimal.
1294 987
1295 config SCHED_INFO 988 config SCHED_INFO
1296 bool 989 bool
1297 default n 990 default n
1298 991
1299 config SCHEDSTATS 992 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 993 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 994 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 995 select SCHED_INFO
1303 help 996 help
1304 If you say Y here, additional code 997 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 998 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 999 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1000 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1001 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1002 application, you can say N to avoid the very slight overhead
1310 this adds. 1003 this adds.
1311 1004
1312 endmenu !! 1005 config SCHED_STACK_END_CHECK
>> 1006 bool "Detect stack corruption on calls to schedule()"
>> 1007 depends on DEBUG_KERNEL
>> 1008 default n
>> 1009 help
>> 1010 This option checks for a stack overrun on calls to schedule().
>> 1011 If the stack end location is found to be over written always panic as
>> 1012 the content of the corrupted region can no longer be trusted.
>> 1013 This is to ensure no erroneous behaviour occurs which could result in
>> 1014 data corruption or a sporadic crash at a later stage once the region
>> 1015 is examined. The runtime overhead introduced is minimal.
1313 1016
1314 config DEBUG_TIMEKEEPING 1017 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1018 bool "Enable extra timekeeping sanity checking"
1316 help 1019 help
1317 This option will enable additional 1020 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1021 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1022 problems are suspected.
1320 1023
1321 This may include checks in the time 1024 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1025 option may have a (very small) performance impact to some
1323 workloads. 1026 workloads.
1324 1027
1325 If unsure, say N. 1028 If unsure, say N.
1326 1029
1327 config DEBUG_PREEMPT 1030 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1031 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION !! 1032 depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
>> 1033 default y
1330 help 1034 help
1331 If you say Y here then the kernel w 1035 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1036 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1037 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1038 will detect preemption count underflows.
1335 1039
1336 This option has potential to introd <<
1337 depending on workload as it trigger <<
1338 this_cpu operation. It should only <<
1339 <<
1340 menu "Lock Debugging (spinlocks, mutexes, etc 1040 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1041
1342 config LOCK_DEBUGGING_SUPPORT 1042 config LOCK_DEBUGGING_SUPPORT
1343 bool 1043 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1044 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1045 default y
1346 1046
1347 config PROVE_LOCKING 1047 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1048 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1049 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1050 select LOCKDEP
1351 select DEBUG_SPINLOCK 1051 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1052 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1053 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1054 select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER
1355 select DEBUG_WW_MUTEX_SLOWPATH 1055 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1056 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE <<
1358 select TRACE_IRQFLAGS 1057 select TRACE_IRQFLAGS
1359 default n 1058 default n
1360 help 1059 help
1361 This feature enables the kernel to p 1060 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1061 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1062 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1063 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1064 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1065 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1066 deadlock.
1368 1067
1369 In short, this feature enables the k 1068 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1069 related deadlocks before they actually occur.
1371 1070
1372 The proof does not depend on how har 1071 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1072 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1073 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1074 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1075 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1076 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1077 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1078 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1079 makes the deadlock theoretically possible).
1381 1080
1382 If a deadlock is impossible (i.e. th 1081 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1082 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1083 kernel reports nothing.
1385 1084
1386 NOTE: this feature can also be enabl 1085 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1086 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1087 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1088 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1089 arbitrary combination of these separate locking variants.
1391 1090
1392 For more details, see Documentation/ !! 1091 For more details, see Documentation/locking/lockdep-design.txt.
1393 <<
1394 config PROVE_RAW_LOCK_NESTING <<
1395 bool "Enable raw_spinlock - spinlock <<
1396 depends on PROVE_LOCKING <<
1397 default n <<
1398 help <<
1399 Enable the raw_spinlock vs. spinlock <<
1400 that the lock nesting rules for PREE <<
1401 not violated. <<
1402 <<
1403 NOTE: There are known nesting proble <<
1404 option expect lockdep splats until t <<
1405 addressed which is work in progress. <<
1406 identify and analyze these problems. <<
1407 check permanently enabled once the m <<
1408 <<
1409 If unsure, select N. <<
1410 1092
1411 config LOCK_STAT 1093 config LOCK_STAT
1412 bool "Lock usage statistics" 1094 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1095 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1096 select LOCKDEP
1415 select DEBUG_SPINLOCK 1097 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1098 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1099 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1100 select DEBUG_LOCK_ALLOC
1419 default n 1101 default n
1420 help 1102 help
1421 This feature enables tracking lock c 1103 This feature enables tracking lock contention points
1422 1104
1423 For more details, see Documentation/ !! 1105 For more details, see Documentation/locking/lockstat.txt
1424 1106
1425 This also enables lock events requir 1107 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1108 subcommand of perf.
1427 If you want to use "perf lock", you 1109 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1110 CONFIG_EVENT_TRACING.
1429 1111
1430 CONFIG_LOCK_STAT defines "contended" 1112 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1113 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1114
1433 config DEBUG_RT_MUTEXES 1115 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1116 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1117 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1118 help
1437 This allows rt mutex semantics viola 1119 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1120 deadlocks (lockups) to be detected and reported automatically.
1439 1121
1440 config DEBUG_SPINLOCK 1122 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1123 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1124 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1125 select UNINLINE_SPIN_UNLOCK
1444 help 1126 help
1445 Say Y here and build SMP to catch m 1127 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1128 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1129 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1130 deadlocks are also debuggable.
1449 1131
1450 config DEBUG_MUTEXES 1132 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1133 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1134 depends on DEBUG_KERNEL
1453 help 1135 help
1454 This feature allows mutex semantics 1136 This feature allows mutex semantics violations to be detected and
1455 reported. 1137 reported.
1456 1138
1457 config DEBUG_WW_MUTEX_SLOWPATH 1139 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1140 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1141 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1142 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1143 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1144 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1145 help
1465 This feature enables slowpath testin 1146 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1147 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1148 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1149 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1150 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1151 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1152 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1153 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1154 you are a distro, do not.
1474 1155
1475 config DEBUG_RWSEMS 1156 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1157 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1158 depends on DEBUG_KERNEL && RWSEM_SPIN_ON_OWNER
1478 help 1159 help
1479 This debugging feature allows misma !! 1160 This debugging feature allows mismatched rw semaphore locks and unlocks
1480 and unlocks to be detected and repo !! 1161 to be detected and reported.
1481 1162
1482 config DEBUG_LOCK_ALLOC 1163 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1164 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1165 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1166 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1167 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1168 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1169 select LOCKDEP
1489 help 1170 help
1490 This feature will check whether any 1171 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1172 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1173 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1174 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1175 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1176 held during task exit.
1496 1177
1497 config LOCKDEP 1178 config LOCKDEP
1498 bool 1179 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1180 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1181 select STACKTRACE
>> 1182 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1501 select KALLSYMS 1183 select KALLSYMS
1502 select KALLSYMS_ALL 1184 select KALLSYMS_ALL
1503 1185
1504 config LOCKDEP_SMALL 1186 config LOCKDEP_SMALL
1505 bool 1187 bool
1506 1188
1507 config LOCKDEP_BITS <<
1508 int "Bitsize for MAX_LOCKDEP_ENTRIES" <<
1509 depends on LOCKDEP && !LOCKDEP_SMALL <<
1510 range 10 30 <<
1511 default 15 <<
1512 help <<
1513 Try increasing this value if you hi <<
1514 <<
1515 config LOCKDEP_CHAINS_BITS <<
1516 int "Bitsize for MAX_LOCKDEP_CHAINS" <<
1517 depends on LOCKDEP && !LOCKDEP_SMALL <<
1518 range 10 30 <<
1519 default 16 <<
1520 help <<
1521 Try increasing this value if you hi <<
1522 <<
1523 config LOCKDEP_STACK_TRACE_BITS <<
1524 int "Bitsize for MAX_STACK_TRACE_ENTR <<
1525 depends on LOCKDEP && !LOCKDEP_SMALL <<
1526 range 10 30 <<
1527 default 19 <<
1528 help <<
1529 Try increasing this value if you hi <<
1530 <<
1531 config LOCKDEP_STACK_TRACE_HASH_BITS <<
1532 int "Bitsize for STACK_TRACE_HASH_SIZ <<
1533 depends on LOCKDEP && !LOCKDEP_SMALL <<
1534 range 10 30 <<
1535 default 14 <<
1536 help <<
1537 Try increasing this value if you ne <<
1538 <<
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS <<
1540 int "Bitsize for elements in circular <<
1541 depends on LOCKDEP <<
1542 range 10 30 <<
1543 default 12 <<
1544 help <<
1545 Try increasing this value if you hi <<
1546 <<
1547 config DEBUG_LOCKDEP 1189 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1190 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1191 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS <<
1551 help 1192 help
1552 If you say Y here, the lock depende 1193 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1194 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1195 of more runtime overhead.
1555 1196
1556 config DEBUG_ATOMIC_SLEEP 1197 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1198 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1199 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1200 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1201 depends on !ARCH_NO_PREEMPT
1561 help 1202 help
1562 If you say Y here, various routines 1203 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1204 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1205 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1206 sections, inside an interrupt, etc...
1566 1207
1567 config DEBUG_LOCKING_API_SELFTESTS 1208 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1209 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1210 depends on DEBUG_KERNEL
1570 help 1211 help
1571 Say Y here if you want the kernel t 1212 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1213 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1214 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1215 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1216 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1217 mutexes and rwsems.
1577 1218
1578 config LOCK_TORTURE_TEST 1219 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1220 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1221 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1222 select TORTURE_TEST
1582 help 1223 help
1583 This option provides a kernel modul 1224 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1225 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1226 after the fact on the running kernel to be tested, if desired.
1586 1227
1587 Say Y here if you want kernel locki 1228 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1229 to be built into the kernel.
1589 Say M if you want these torture tes 1230 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1231 Say N if you are unsure.
1591 1232
1592 config WW_MUTEX_SELFTEST 1233 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1234 tristate "Wait/wound mutex selftests"
1594 help 1235 help
1595 This option provides a kernel modul 1236 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1237 on the struct ww_mutex locking API.
1597 1238
1598 It is recommended to enable DEBUG_W 1239 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1240 with this test harness.
1600 1241
1601 Say M if you want these self tests 1242 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1243 Say N if you are unsure.
1603 1244
1604 config SCF_TORTURE_TEST <<
1605 tristate "torture tests for smp_call_ <<
1606 depends on DEBUG_KERNEL <<
1607 select TORTURE_TEST <<
1608 help <<
1609 This option provides a kernel modul <<
1610 on the smp_call_function() family o <<
1611 module may be built after the fact <<
1612 be tested, if desired. <<
1613 <<
1614 config CSD_LOCK_WAIT_DEBUG <<
1615 bool "Debugging for csd_lock_wait(), <<
1616 depends on DEBUG_KERNEL <<
1617 depends on 64BIT <<
1618 default n <<
1619 help <<
1620 This option enables debug prints wh <<
1621 to the smp_call_function*() IPI wra <<
1622 include the IPI handler function cu <<
1623 and relevant stack traces. <<
1624 <<
1625 config CSD_LOCK_WAIT_DEBUG_DEFAULT <<
1626 bool "Default csd_lock_wait() debuggi <<
1627 depends on CSD_LOCK_WAIT_DEBUG <<
1628 depends on 64BIT <<
1629 default n <<
1630 help <<
1631 This option causes the csdlock_debu <<
1632 default to 1 (basic debugging) inst <<
1633 <<
1634 endmenu # lock debugging 1245 endmenu # lock debugging
1635 1246
1636 config TRACE_IRQFLAGS 1247 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT <<
1638 bool 1248 bool
1639 help 1249 help
1640 Enables hooks to interrupt enabling 1250 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1251 either tracing or lock debugging.
1642 1252
1643 config TRACE_IRQFLAGS_NMI <<
1644 def_bool y <<
1645 depends on TRACE_IRQFLAGS <<
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT <<
1647 <<
1648 config NMI_CHECK_CPU <<
1649 bool "Debugging for CPUs failing to r <<
1650 depends on DEBUG_KERNEL <<
1651 depends on X86 <<
1652 default n <<
1653 help <<
1654 Enables debug prints when a CPU fai <<
1655 backtrace NMI. These prints provid <<
1656 might legitimately be failing to re <<
1657 is offline of if ignore_nmis is set <<
1658 <<
1659 config DEBUG_IRQFLAGS <<
1660 bool "Debug IRQ flag manipulation" <<
1661 help <<
1662 Enables checks for potentially unsa <<
1663 interrupts, such as calling raw_loc <<
1664 are enabled. <<
1665 <<
1666 config STACKTRACE 1253 config STACKTRACE
1667 bool "Stack backtrace support" 1254 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1255 depends on STACKTRACE_SUPPORT
1669 help 1256 help
1670 This option causes the kernel to cr 1257 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1258 every process, showing its current stack trace.
1672 It is also used by various kernel d 1259 It is also used by various kernel debugging features that require
1673 stack trace generation. 1260 stack trace generation.
1674 1261
1675 config WARN_ALL_UNSEEDED_RANDOM 1262 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1263 bool "Warn for all uses of unseeded randomness"
1677 default n 1264 default n
1678 help 1265 help
1679 Some parts of the kernel contain bu 1266 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1267 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1268 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1269 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1270 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1271 are going wrong, so that they might contact developers about fixing
1685 it. 1272 it.
1686 1273
1687 Unfortunately, on some models of so 1274 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1275 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1276 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1277 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1278 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1279 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1280 However, since users cannot do anything actionable to
1694 address this, by default this optio !! 1281 address this, by default the kernel will issue only a single
>> 1282 warning for the first use of unseeded randomness.
1695 1283
1696 Say Y here if you want to receive w 1284 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1285 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1286 those developers interested in improving the security of
1699 Linux kernels running on their arch 1287 Linux kernels running on their architecture (or
1700 subarchitecture). 1288 subarchitecture).
1701 1289
1702 config DEBUG_KOBJECT 1290 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1291 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1292 depends on DEBUG_KERNEL
1705 help 1293 help
1706 If you say Y here, some extra kobje 1294 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1295 to the syslog.
1708 1296
1709 config DEBUG_KOBJECT_RELEASE 1297 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1298 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1299 depends on DEBUG_OBJECTS_TIMERS
1712 help 1300 help
1713 kobjects are reference counted obje 1301 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1302 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1303 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1304 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1305 example of this would be a struct device which has just been
1718 unregistered. 1306 unregistered.
1719 1307
1720 However, some buggy drivers assume 1308 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1309 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1310 goes completely against the principles of a refcounted object.
1723 1311
1724 If you say Y here, the kernel will 1312 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1313 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1314 kind of kobject release bug.
1727 1315
1728 config HAVE_DEBUG_BUGVERBOSE 1316 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1317 bool
1730 1318
1731 menu "Debug kernel data structures" !! 1319 config DEBUG_BUGVERBOSE
>> 1320 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
>> 1321 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
>> 1322 default y
>> 1323 help
>> 1324 Say Y here to make BUG() panics output the file name and line number
>> 1325 of the BUG call as well as the EIP and oops trace. This aids
>> 1326 debugging but costs about 70-100K of memory.
1732 1327
1733 config DEBUG_LIST 1328 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1329 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1330 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1331 help
1738 Enable this to turn on extended che !! 1332 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1333 walking routines.
1740 <<
1741 This option trades better quality e <<
1742 is more suitable for kernel debuggi <<
1743 you should only enable CONFIG_LIST_ <<
1744 1334
1745 If unsure, say N. 1335 If unsure, say N.
1746 1336
1747 config DEBUG_PLIST !! 1337 config DEBUG_PI_LIST
1748 bool "Debug priority linked list mani 1338 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1339 depends on DEBUG_KERNEL
1750 help 1340 help
1751 Enable this to turn on extended che 1341 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1342 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1343 list multiple times during each manipulation.
1754 1344
1755 If unsure, say N. 1345 If unsure, say N.
1756 1346
1757 config DEBUG_SG 1347 config DEBUG_SG
1758 bool "Debug SG table operations" 1348 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1349 depends on DEBUG_KERNEL
1760 help 1350 help
1761 Enable this to turn on checks on sc 1351 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1352 help find problems with drivers that do not properly initialize
1763 their sg tables. 1353 their sg tables.
1764 1354
1765 If unsure, say N. 1355 If unsure, say N.
1766 1356
1767 config DEBUG_NOTIFIERS 1357 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1358 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1359 depends on DEBUG_KERNEL
1770 help 1360 help
1771 Enable this to turn on sanity check 1361 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1362 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1363 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1364 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1365 performance, say N.
1776 1366
1777 config DEBUG_CLOSURES !! 1367 config DEBUG_CREDENTIALS
1778 bool "Debug closures (bcache async wi !! 1368 bool "Debug credential management"
1779 depends on CLOSURES <<
1780 select DEBUG_FS <<
1781 help <<
1782 Keeps all active closures in a link <<
1783 interface to list them, which makes <<
1784 operations that get stuck. <<
1785 <<
1786 config DEBUG_MAPLE_TREE <<
1787 bool "Debug maple trees" <<
1788 depends on DEBUG_KERNEL 1369 depends on DEBUG_KERNEL
1789 help 1370 help
1790 Enable maple tree debugging informa !! 1371 Enable this to turn on some debug checking for credential
>> 1372 management. The additional code keeps track of the number of
>> 1373 pointers from task_structs to any given cred struct, and checks to
>> 1374 see that this number never exceeds the usage count of the cred
>> 1375 struct.
1791 1376
1792 If unsure, say N. !! 1377 Furthermore, if SELinux is enabled, this also checks that the
>> 1378 security pointer in the cred struct is never seen to be invalid.
1793 1379
1794 endmenu !! 1380 If unsure, say N.
1795 1381
1796 source "kernel/rcu/Kconfig.debug" 1382 source "kernel/rcu/Kconfig.debug"
1797 1383
1798 config DEBUG_WQ_FORCE_RR_CPU 1384 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1385 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1386 depends on DEBUG_KERNEL
1801 default n 1387 default n
1802 help 1388 help
1803 Workqueue used to implicitly guaran 1389 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1390 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1391 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1392 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1393 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1394 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1395 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1396 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1397 be impacted.
1812 1398
>> 1399 config DEBUG_BLOCK_EXT_DEVT
>> 1400 bool "Force extended block device numbers and spread them"
>> 1401 depends on DEBUG_KERNEL
>> 1402 depends on BLOCK
>> 1403 default n
>> 1404 help
>> 1405 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1406 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1407 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1408 is broken.
>> 1409
>> 1410 Conventionally, block device numbers are allocated from
>> 1411 predetermined contiguous area. However, extended block area
>> 1412 may introduce non-contiguous block device numbers. This
>> 1413 option forces most block device numbers to be allocated from
>> 1414 the extended space and spreads them to discover kernel or
>> 1415 userland code paths which assume predetermined contiguous
>> 1416 device number allocation.
>> 1417
>> 1418 Note that turning on this debug option shuffles all the
>> 1419 device numbers for all IDE and SCSI devices including libata
>> 1420 ones, so root partition specified using device number
>> 1421 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1422 Textual device names (root=/dev/sdXn) will continue to work.
>> 1423
>> 1424 Say N if you are unsure.
>> 1425
1813 config CPU_HOTPLUG_STATE_CONTROL 1426 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1427 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1428 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1429 depends on HOTPLUG_CPU
1817 default n 1430 default n
1818 help 1431 help
1819 Allows to write steps between "offl 1432 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1433 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1434 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1435 restarted at arbitrary points yet.
1823 1436
1824 Say N if your are unsure. 1437 Say N if your are unsure.
1825 1438
1826 config LATENCYTOP <<
1827 bool "Latency measuring infrastructur <<
1828 depends on DEBUG_KERNEL <<
1829 depends on STACKTRACE_SUPPORT <<
1830 depends on PROC_FS <<
1831 depends on FRAME_POINTER || MIPS || P <<
1832 select KALLSYMS <<
1833 select KALLSYMS_ALL <<
1834 select STACKTRACE <<
1835 select SCHEDSTATS <<
1836 help <<
1837 Enable this option if you want to u <<
1838 to find out which userspace is bloc <<
1839 <<
1840 config DEBUG_CGROUP_REF <<
1841 bool "Disable inlining of cgroup css <<
1842 depends on DEBUG_KERNEL <<
1843 depends on CGROUPS <<
1844 depends on KPROBES <<
1845 default n <<
1846 help <<
1847 Force cgroup css reference count fu <<
1848 that they can be kprobed for debugg <<
1849 <<
1850 source "kernel/trace/Kconfig" <<
1851 <<
1852 config PROVIDE_OHCI1394_DMA_INIT <<
1853 bool "Remote debugging over FireWire <<
1854 depends on PCI && X86 <<
1855 help <<
1856 If you want to debug problems which <<
1857 on boot and the crashing machine ha <<
1858 this feature to remotely access the <<
1859 over FireWire. This employs remote <<
1860 specification which is now the stan <<
1861 <<
1862 With remote DMA, you can monitor th <<
1863 firescope and access all memory bel <<
1864 Even controlling a kernel debugger <<
1865 <<
1866 Usage: <<
1867 <<
1868 If ohci1394_dma=early is used as bo <<
1869 all OHCI1394 controllers which are <<
1870 <<
1871 As all changes to the FireWire bus <<
1872 devices cause a bus reset and there <<
1873 devices, be sure to have the cable <<
1874 the debugging host before booting t <<
1875 <<
1876 This code (~1k) is freed after boot <<
1877 in charge of the OHCI-1394 controll <<
1878 <<
1879 See Documentation/core-api/debuggin <<
1880 <<
1881 source "samples/Kconfig" <<
1882 <<
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED <<
1884 bool <<
1885 <<
1886 config STRICT_DEVMEM <<
1887 bool "Filter access to /dev/mem" <<
1888 depends on MMU && DEVMEM <<
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED <<
1890 default y if PPC || X86 || ARM64 <<
1891 help <<
1892 If this option is disabled, you all <<
1893 of memory, including kernel and use <<
1894 access to this is obviously disastr <<
1895 be used by people debugging the ker <<
1896 enabled, even in this case there ar <<
1897 use due to the cache aliasing requi <<
1898 <<
1899 If this option is switched on, and <<
1900 file only allows userspace access t <<
1901 data regions. This is sufficient f <<
1902 users of /dev/mem. <<
1903 <<
1904 If in doubt, say Y. <<
1905 <<
1906 config IO_STRICT_DEVMEM <<
1907 bool "Filter I/O access to /dev/mem" <<
1908 depends on STRICT_DEVMEM <<
1909 help <<
1910 If this option is disabled, you all <<
1911 io-memory regardless of whether a d <<
1912 range. Accidental access to this i <<
1913 specific access can be used by peop <<
1914 <<
1915 If this option is switched on, the <<
1916 userspace access to *idle* io-memor <<
1917 may break traditional users of /dev <<
1918 if the driver using a given range c <<
1919 <<
1920 If in doubt, say Y. <<
1921 <<
1922 menu "$(SRCARCH) Debugging" <<
1923 <<
1924 source "arch/$(SRCARCH)/Kconfig.debug" <<
1925 <<
1926 endmenu <<
1927 <<
1928 menu "Kernel Testing and Coverage" <<
1929 <<
1930 source "lib/kunit/Kconfig" <<
1931 <<
1932 config NOTIFIER_ERROR_INJECTION 1439 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1440 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1441 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1442 select DEBUG_FS
1936 help 1443 help
1937 This option provides the ability to 1444 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1445 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1446 handling of notifier call chain failures.
1940 1447
1941 Say N if unsure. 1448 Say N if unsure.
1942 1449
1943 config PM_NOTIFIER_ERROR_INJECT 1450 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1451 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1452 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1453 default m if PM_DEBUG
1947 help 1454 help
1948 This option provides the ability to 1455 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1456 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1457 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1458
1952 If the notifier call chain should b 1459 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1460 notified, write the error code to "actions/<notifier event>/error".
1954 1461
1955 Example: Inject PM suspend error (- 1462 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1463
1957 # cd /sys/kernel/debug/notifier-err 1464 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1465 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1466 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1467 bash: echo: write error: Cannot allocate memory
1961 1468
1962 To compile this code as a module, c 1469 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1470 be called pm-notifier-error-inject.
1964 1471
1965 If unsure, say N. 1472 If unsure, say N.
1966 1473
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1474 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1475 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1476 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1477 help
1971 This option provides the ability to 1478 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1479 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1480 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1481 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1482
1976 If the notifier call chain should b 1483 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1484 notified, write the error code to "actions/<notifier event>/error".
1978 1485
1979 To compile this code as a module, c 1486 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1487 be called of-reconfig-notifier-error-inject.
1981 1488
1982 If unsure, say N. 1489 If unsure, say N.
1983 1490
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1491 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1492 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1493 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1494 help
1988 This option provides the ability to 1495 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1496 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1497 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1498
1992 If the notifier call chain should b 1499 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1500 notified, write the error code to "actions/<notifier event>/error".
1994 1501
1995 Example: Inject netdevice mtu chang 1502 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1503
1997 # cd /sys/kernel/debug/notifier-err 1504 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1505 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1506 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1507 RTNETLINK answers: Invalid argument
2001 1508
2002 To compile this code as a module, c 1509 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1510 be called netdev-notifier-error-inject.
2004 1511
2005 If unsure, say N. 1512 If unsure, say N.
2006 1513
2007 config FUNCTION_ERROR_INJECTION 1514 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" !! 1515 def_bool y
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1516 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010 help <<
2011 Add fault injections into various f <<
2012 ALLOW_ERROR_INJECTION() in the kern <<
2013 value of these functions. This is u <<
2014 <<
2015 If unsure, say N <<
2016 1517
2017 config FAULT_INJECTION 1518 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1519 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1520 depends on DEBUG_KERNEL
2020 help 1521 help
2021 Provide fault-injection framework. 1522 Provide fault-injection framework.
2022 For more details, see Documentation 1523 For more details, see Documentation/fault-injection/.
2023 1524
2024 config FAILSLAB 1525 config FAILSLAB
2025 bool "Fault-injection capability for 1526 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1527 depends on FAULT_INJECTION
>> 1528 depends on SLAB || SLUB
2027 help 1529 help
2028 Provide fault-injection capability 1530 Provide fault-injection capability for kmalloc.
2029 1531
2030 config FAIL_PAGE_ALLOC 1532 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for !! 1533 bool "Fault-injection capabilitiy for alloc_pages()"
2032 depends on FAULT_INJECTION 1534 depends on FAULT_INJECTION
2033 help 1535 help
2034 Provide fault-injection capability 1536 Provide fault-injection capability for alloc_pages().
2035 1537
2036 config FAULT_INJECTION_USERCOPY <<
2037 bool "Fault injection capability for <<
2038 depends on FAULT_INJECTION <<
2039 help <<
2040 Provides fault-injection capability <<
2041 in usercopy functions (copy_from_us <<
2042 <<
2043 config FAIL_MAKE_REQUEST 1538 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1539 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1540 depends on FAULT_INJECTION && BLOCK
2046 help 1541 help
2047 Provide fault-injection capability 1542 Provide fault-injection capability for disk IO.
2048 1543
2049 config FAIL_IO_TIMEOUT 1544 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1545 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1546 depends on FAULT_INJECTION && BLOCK
2052 help 1547 help
2053 Provide fault-injection capability 1548 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1549 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1550 thus exercising the error handling.
2056 1551
2057 Only works with drivers that use th 1552 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1553 for others it wont do anything.
2059 1554
2060 config FAIL_FUTEX 1555 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1556 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1557 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1558 depends on FAULT_INJECTION && FUTEX
2064 help 1559 help
2065 Provide fault-injection capability 1560 Provide fault-injection capability for futexes.
2066 1561
2067 config FAULT_INJECTION_DEBUG_FS 1562 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1563 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1564 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1565 help
2071 Enable configuration of fault-injec 1566 Enable configuration of fault-injection capabilities via debugfs.
2072 1567
2073 config FAIL_FUNCTION 1568 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1569 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1570 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1571 help
2077 Provide function-based fault-inject 1572 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1573 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1574 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1575 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1576 error handling in various subsystems.
2082 1577
2083 config FAIL_MMC_REQUEST 1578 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1579 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1580 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1581 help
2087 Provide fault-injection capability 1582 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1583 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1584 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1585 and to test how the mmc host driver handles retries from
2091 the block device. 1586 the block device.
2092 1587
2093 config FAIL_SUNRPC <<
2094 bool "Fault-injection capability for <<
2095 depends on FAULT_INJECTION_DEBUG_FS & <<
2096 help <<
2097 Provide fault-injection capability <<
2098 its consumers. <<
2099 <<
2100 config FAULT_INJECTION_CONFIGFS <<
2101 bool "Configfs interface for fault-in <<
2102 depends on FAULT_INJECTION <<
2103 select CONFIGFS_FS <<
2104 help <<
2105 This option allows configfs-based d <<
2106 fault-injection via configfs. Each <<
2107 fault-injection can be made visible <<
2108 configfs group. <<
2109 <<
2110 <<
2111 config FAULT_INJECTION_STACKTRACE_FILTER 1588 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1589 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1590 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1591 depends on !X86_64
2115 select STACKTRACE 1592 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P !! 1593 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
2117 help 1594 help
2118 Provide stacktrace filter for fault 1595 Provide stacktrace filter for fault-injection capabilities
2119 1596
2120 config ARCH_HAS_KCOV !! 1597 config LATENCYTOP
2121 bool !! 1598 bool "Latency measuring infrastructure"
>> 1599 depends on DEBUG_KERNEL
>> 1600 depends on STACKTRACE_SUPPORT
>> 1601 depends on PROC_FS
>> 1602 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
>> 1603 select KALLSYMS
>> 1604 select KALLSYMS_ALL
>> 1605 select STACKTRACE
>> 1606 select SCHEDSTATS
>> 1607 select SCHED_DEBUG
2122 help 1608 help
2123 An architecture should select this !! 1609 Enable this option if you want to use the LatencyTOP tool
2124 build and run with CONFIG_KCOV. Thi !! 1610 to find out which userspace is blocking on what kernel operations.
2125 disabling instrumentation for some <<
2126 <<
2127 config CC_HAS_SANCOV_TRACE_PC <<
2128 def_bool $(cc-option,-fsanitize-cover <<
2129 1611
>> 1612 source kernel/trace/Kconfig
2130 1613
2131 config KCOV !! 1614 config PROVIDE_OHCI1394_DMA_INIT
2132 bool "Code coverage for fuzzing" !! 1615 bool "Remote debugging over FireWire early on boot"
2133 depends on ARCH_HAS_KCOV !! 1616 depends on PCI && X86
2134 depends on CC_HAS_SANCOV_TRACE_PC || <<
2135 depends on !ARCH_WANTS_NO_INSTR || HA <<
2136 GCC_VERSION >= 120000 || C <<
2137 select DEBUG_FS <<
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S <<
2139 select OBJTOOL if HAVE_NOINSTR_HACK <<
2140 help 1617 help
2141 KCOV exposes kernel code coverage i !! 1618 If you want to debug problems which hang or crash the kernel early
2142 for coverage-guided fuzzing (random !! 1619 on boot and the crashing machine has a FireWire port, you can use
>> 1620 this feature to remotely access the memory of the crashed machine
>> 1621 over FireWire. This employs remote DMA as part of the OHCI1394
>> 1622 specification which is now the standard for FireWire controllers.
2143 1623
2144 For more details, see Documentation !! 1624 With remote DMA, you can monitor the printk buffer remotely using
>> 1625 firescope and access all memory below 4GB using fireproxy from gdb.
>> 1626 Even controlling a kernel debugger is possible using remote DMA.
2145 1627
2146 config KCOV_ENABLE_COMPARISONS !! 1628 Usage:
2147 bool "Enable comparison operands coll <<
2148 depends on KCOV <<
2149 depends on $(cc-option,-fsanitize-cov <<
2150 help <<
2151 KCOV also exposes operands of every <<
2152 code along with operand sizes and P <<
2153 These operands can be used by fuzzi <<
2154 of fuzzing coverage. <<
2155 1629
2156 config KCOV_INSTRUMENT_ALL !! 1630 If ohci1394_dma=early is used as boot parameter, it will initialize
2157 bool "Instrument all code by default" !! 1631 all OHCI1394 controllers which are found in the PCI config space.
2158 depends on KCOV <<
2159 default y <<
2160 help <<
2161 If you are doing generic system cal <<
2162 then you will want to instrument th <<
2163 say y here. If you are doing more t <<
2164 filesystem fuzzing with AFL) then y <<
2165 for more specific subsets of files, <<
2166 1632
2167 config KCOV_IRQ_AREA_SIZE !! 1633 As all changes to the FireWire bus such as enabling and disabling
2168 hex "Size of interrupt coverage colle !! 1634 devices cause a bus reset and thereby disable remote DMA for all
2169 depends on KCOV !! 1635 devices, be sure to have the cable plugged and FireWire enabled on
2170 default 0x40000 !! 1636 the debugging host before booting the debug target for debugging.
2171 help <<
2172 KCOV uses preallocated per-cpu area <<
2173 soft interrupts. This specifies the <<
2174 number of unsigned long words. <<
2175 1637
2176 menuconfig RUNTIME_TESTING_MENU !! 1638 This code (~1k) is freed after boot. By then, the firewire stack
2177 bool "Runtime Testing" !! 1639 in charge of the OHCI-1394 controllers should be used instead.
2178 default y <<
2179 1640
2180 if RUNTIME_TESTING_MENU !! 1641 See Documentation/debugging-via-ohci1394.txt for more information.
2181 1642
2182 config TEST_DHRY !! 1643 config DMA_API_DEBUG
2183 tristate "Dhrystone benchmark test" !! 1644 bool "Enable debugging of DMA-API usage"
>> 1645 select NEED_DMA_MAP_STATE
2184 help 1646 help
2185 Enable this to include the Dhryston !! 1647 Enable this option to debug the use of the DMA API by device drivers.
2186 calculates the number of Dhrystones !! 1648 With this option you will be able to detect common bugs in device
2187 DMIPS (Dhrystone MIPS) obtained whe !! 1649 drivers like double-freeing of DMA mappings or freeing mappings that
2188 by 1757 (the number of Dhrystones p !! 1650 were never allocated.
2189 11/780, nominally a 1 MIPS machine) <<
2190 1651
2191 To run the benchmark, it needs to b !! 1652 This also attempts to catch cases where a page owned by DMA is
2192 the kernel command line (when built !! 1653 accessed by the cpu in a way that could cause data corruption. For
2193 built-in or modular). !! 1654 example, this enables cow_user_page() to check that the source page is
>> 1655 not undergoing DMA.
2194 1656
2195 Run once during kernel boot: !! 1657 This option causes a performance degradation. Use only if you want to
>> 1658 debug device drivers and dma interactions.
2196 1659
2197 test_dhry.run !! 1660 If unsure, say N.
2198 <<
2199 Set number of iterations from kerne <<
2200 <<
2201 test_dhry.iterations=<n> <<
2202 <<
2203 Set number of iterations from users <<
2204 <<
2205 echo <n> > /sys/module/test_dhr <<
2206 1661
2207 Trigger manual run from userspace: !! 1662 config DMA_API_DEBUG_SG
>> 1663 bool "Debug DMA scatter-gather usage"
>> 1664 default y
>> 1665 depends on DMA_API_DEBUG
>> 1666 help
>> 1667 Perform extra checking that callers of dma_map_sg() have respected the
>> 1668 appropriate segment length/boundary limits for the given device when
>> 1669 preparing DMA scatterlists.
>> 1670
>> 1671 This is particularly likely to have been overlooked in cases where the
>> 1672 dma_map_sg() API is used for general bulk mapping of pages rather than
>> 1673 preparing literal scatter-gather descriptors, where there is a risk of
>> 1674 unexpected behaviour from DMA API implementations if the scatterlist
>> 1675 is technically out-of-spec.
2208 1676
2209 echo y > /sys/module/test_dhry/ !! 1677 If unsure, say N.
2210 1678
2211 If the number of iterations is <= 0 !! 1679 menuconfig RUNTIME_TESTING_MENU
2212 number of iterations (test runs for !! 1680 bool "Runtime Testing"
2213 This process takes ca. 4s. !! 1681 def_bool y
2214 1682
2215 If unsure, say N. !! 1683 if RUNTIME_TESTING_MENU
2216 1684
2217 config LKDTM 1685 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 1686 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 1687 depends on DEBUG_FS
>> 1688 depends on BLOCK
2220 help 1689 help
2221 This module enables testing of the di 1690 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 1691 inducing system failures at predefined crash points.
2223 If you don't need it: say N 1692 If you don't need it: say N
2224 Choose M here to compile this code as 1693 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 1694 called lkdtm.
2226 1695
2227 Documentation on how to use the modul 1696 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke !! 1697 Documentation/fault-injection/provoke-crashes.txt
2229 <<
2230 config CPUMASK_KUNIT_TEST <<
2231 tristate "KUnit test for cpumask" if <<
2232 depends on KUNIT <<
2233 default KUNIT_ALL_TESTS <<
2234 help <<
2235 Enable to turn on cpumask tests, ru <<
2236 <<
2237 For more information on KUnit and u <<
2238 to the KUnit documentation in Docum <<
2239 <<
2240 If unsure, say N. <<
2241 1698
2242 config TEST_LIST_SORT 1699 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 1700 tristate "Linked list sorting test"
2244 depends on KUNIT <<
2245 default KUNIT_ALL_TESTS <<
2246 help <<
2247 Enable this to turn on 'list_sort() <<
2248 executed only once during system bo <<
2249 or at module load time. <<
2250 <<
2251 If unsure, say N. <<
2252 <<
2253 config TEST_MIN_HEAP <<
2254 tristate "Min heap test" <<
2255 depends on DEBUG_KERNEL || m 1701 depends on DEBUG_KERNEL || m
2256 help 1702 help
2257 Enable this to turn on min heap fun !! 1703 Enable this to turn on 'list_sort()' function test. This test is
2258 executed only once during system bo 1704 executed only once during system boot (so affects only boot time),
2259 or at module load time. 1705 or at module load time.
2260 1706
2261 If unsure, say N. 1707 If unsure, say N.
2262 1708
2263 config TEST_SORT 1709 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 1710 tristate "Array-based sort test"
2265 depends on KUNIT <<
2266 default KUNIT_ALL_TESTS <<
2267 help <<
2268 This option enables the self-test f <<
2269 or at module load time. <<
2270 <<
2271 If unsure, say N. <<
2272 <<
2273 config TEST_DIV64 <<
2274 tristate "64bit/32bit division and mo <<
2275 depends on DEBUG_KERNEL || m 1711 depends on DEBUG_KERNEL || m
2276 help 1712 help
2277 Enable this to turn on 'do_div()' f !! 1713 This option enables the self-test function of 'sort()' at boot,
2278 executed only once during system bo <<
2279 or at module load time. 1714 or at module load time.
2280 1715
2281 If unsure, say N. 1716 If unsure, say N.
2282 1717
2283 config TEST_IOV_ITER <<
2284 tristate "Test iov_iter operation" if <<
2285 depends on KUNIT <<
2286 depends on MMU <<
2287 default KUNIT_ALL_TESTS <<
2288 help <<
2289 Enable this to turn on testing of t <<
2290 (iov_iter). This test is executed o <<
2291 affects only boot time), or at modu <<
2292 <<
2293 If unsure, say N. <<
2294 <<
2295 config KPROBES_SANITY_TEST 1718 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 1719 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 1720 depends on DEBUG_KERNEL
2298 depends on KPROBES 1721 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 1722 help
2303 This option provides for testing ba 1723 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 1724 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 1725 verified for functionality.
2306 1726
2307 Say N if you are unsure. 1727 Say N if you are unsure.
2308 1728
2309 config FPROBE_SANITY_TEST <<
2310 bool "Self test for fprobe" <<
2311 depends on DEBUG_KERNEL <<
2312 depends on FPROBE <<
2313 depends on KUNIT=y <<
2314 help <<
2315 This option will enable testing the <<
2316 A series of tests are made to verif <<
2317 properly. <<
2318 <<
2319 Say N if you are unsure. <<
2320 <<
2321 config BACKTRACE_SELF_TEST 1729 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 1730 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 1731 depends on DEBUG_KERNEL
2324 help 1732 help
2325 This option provides a kernel modul 1733 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 1734 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 1735 for distributions or general kernels, but only for kernel
2328 developers working on architecture 1736 developers working on architecture code.
2329 1737
2330 Note that if you want to also test 1738 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 1739 have to enable STACKTRACE as well.
2332 1740
2333 Say N if you are unsure. 1741 Say N if you are unsure.
2334 1742
2335 config TEST_REF_TRACKER <<
2336 tristate "Self test for reference tra <<
2337 depends on DEBUG_KERNEL && STACKTRACE <<
2338 select REF_TRACKER <<
2339 help <<
2340 This option provides a kernel modul <<
2341 using reference tracker infrastruct <<
2342 <<
2343 Say N if you are unsure. <<
2344 <<
2345 config RBTREE_TEST 1743 config RBTREE_TEST
2346 tristate "Red-Black tree test" 1744 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 1745 depends on DEBUG_KERNEL
2348 help 1746 help
2349 A benchmark measuring the performan 1747 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 1748 Also includes rbtree invariant checks.
2351 1749
2352 config REED_SOLOMON_TEST <<
2353 tristate "Reed-Solomon library test" <<
2354 depends on DEBUG_KERNEL || m <<
2355 select REED_SOLOMON <<
2356 select REED_SOLOMON_ENC16 <<
2357 select REED_SOLOMON_DEC16 <<
2358 help <<
2359 This option enables the self-test f <<
2360 or at module load time. <<
2361 <<
2362 If unsure, say N. <<
2363 <<
2364 config INTERVAL_TREE_TEST 1750 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 1751 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 1752 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 1753 select INTERVAL_TREE
2368 help 1754 help
2369 A benchmark measuring the performan 1755 A benchmark measuring the performance of the interval tree library
2370 1756
2371 config PERCPU_TEST 1757 config PERCPU_TEST
2372 tristate "Per cpu operations test" 1758 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 1759 depends on m && DEBUG_KERNEL
2374 help 1760 help
2375 Enable this option to build test mo 1761 Enable this option to build test module which validates per-cpu
2376 operations. 1762 operations.
2377 1763
2378 If unsure, say N. 1764 If unsure, say N.
2379 1765
2380 config ATOMIC64_SELFTEST 1766 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 1767 tristate "Perform an atomic64_t self-test"
2382 help 1768 help
2383 Enable this option to test the atom 1769 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 1770 at module load time.
2385 1771
2386 If unsure, say N. 1772 If unsure, say N.
2387 1773
2388 config ASYNC_RAID6_TEST 1774 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 1775 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 1776 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 1777 select ASYNC_MEMCPY
2392 help !! 1778 ---help---
2393 This is a one-shot self test that p 1779 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 1780 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 1781 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 1782 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 1783 engine if one is available.
2398 1784
2399 If unsure, say N. 1785 If unsure, say N.
2400 1786
2401 config TEST_HEXDUMP 1787 config TEST_HEXDUMP
2402 tristate "Test functions located in t 1788 tristate "Test functions located in the hexdump module at runtime"
2403 1789
2404 config STRING_KUNIT_TEST !! 1790 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 1791 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 <<
2409 config STRING_HELPERS_KUNIT_TEST <<
2410 tristate "KUnit test string helpers a <<
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 1792
2414 config TEST_KSTRTOX 1793 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 1794 tristate "Test kstrto*() family of functions at runtime"
2416 1795
2417 config TEST_PRINTF 1796 config TEST_PRINTF
2418 tristate "Test printf() family of fun 1797 tristate "Test printf() family of functions at runtime"
2419 1798
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 1799 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 1800 tristate "Test bitmap_*() family of functions at runtime"
2425 help 1801 help
2426 Enable this option to test the bitm 1802 Enable this option to test the bitmap functions at boot.
2427 1803
2428 If unsure, say N. 1804 If unsure, say N.
2429 1805
>> 1806 config TEST_BITFIELD
>> 1807 tristate "Test bitfield functions at runtime"
>> 1808 help
>> 1809 Enable this option to test the bitfield functions at boot.
>> 1810
>> 1811 If unsure, say N.
>> 1812
2430 config TEST_UUID 1813 config TEST_UUID
2431 tristate "Test functions located in t 1814 tristate "Test functions located in the uuid module at runtime"
2432 1815
2433 config TEST_XARRAY 1816 config TEST_XARRAY
2434 tristate "Test the XArray code at run 1817 tristate "Test the XArray code at runtime"
2435 1818
2436 config TEST_MAPLE_TREE !! 1819 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 1820 tristate "Test check_*_overflow() functions at runtime"
2438 help <<
2439 Enable this option to test the mapl <<
2440 when the module is loaded. Enable " <<
2441 more verbose output on failures. <<
2442 <<
2443 If unsure, say N. <<
2444 1821
2445 config TEST_RHASHTABLE 1822 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 1823 tristate "Perform selftest on resizable hash table"
2447 help 1824 help
2448 Enable this option to test the rhas 1825 Enable this option to test the rhashtable functions at boot.
2449 1826
2450 If unsure, say N. 1827 If unsure, say N.
2451 1828
>> 1829 config TEST_HASH
>> 1830 tristate "Perform selftest on hash functions"
>> 1831 help
>> 1832 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 1833 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 1834 hash functions on boot (or module load).
>> 1835
>> 1836 This is intended to help people writing architecture-specific
>> 1837 optimized versions. If unsure, say N.
>> 1838
2452 config TEST_IDA 1839 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 1840 tristate "Perform selftest on IDA functions"
2454 1841
2455 config TEST_PARMAN 1842 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 1843 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 1844 depends on PARMAN
2458 help 1845 help
2459 Enable this option to test priority 1846 Enable this option to test priority array manager on boot
2460 (or module load). 1847 (or module load).
2461 1848
2462 If unsure, say N. 1849 If unsure, say N.
2463 1850
2464 config TEST_IRQ_TIMINGS <<
2465 bool "IRQ timings selftest" <<
2466 depends on IRQ_TIMINGS <<
2467 help <<
2468 Enable this option to test the irq <<
2469 <<
2470 If unsure, say N. <<
2471 <<
2472 config TEST_LKM 1851 config TEST_LKM
2473 tristate "Test module loading with 'h 1852 tristate "Test module loading with 'hello world' module"
2474 depends on m 1853 depends on m
2475 help 1854 help
2476 This builds the "test_module" modul 1855 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 1856 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 1857 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 1858 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 1859 and will not normally be loaded by the system unless explicitly
2481 requested by name. 1860 requested by name.
2482 1861
2483 If unsure, say N. 1862 If unsure, say N.
2484 1863
2485 config TEST_BITOPS !! 1864 config TEST_USER_COPY
2486 tristate "Test module for compilation !! 1865 tristate "Test user/kernel boundary protections"
2487 help <<
2488 This builds the "test_bitops" modul <<
2489 TEST_LKM module except that it does <<
2490 set/clear_bit macros and get_count_ <<
2491 no compiler warnings from C=1 spars <<
2492 compilations. It has no dependencie <<
2493 explicitly requested by name. for <<
2494 <<
2495 If unsure, say N. <<
2496 <<
2497 config TEST_VMALLOC <<
2498 tristate "Test module for stress/perf <<
2499 default n <<
2500 depends on MMU <<
2501 depends on m 1866 depends on m
2502 help 1867 help
2503 This builds the "test_vmalloc" modu !! 1868 This builds the "test_user_copy" module that runs sanity checks
2504 stress and performance analysis. So !! 1869 on the copy_to/from_user infrastructure, making sure basic
2505 subsystem can be evaluated from per !! 1870 user/kernel boundary testing is working. If it fails to load,
2506 of view. !! 1871 a regression has been detected in the user/kernel memory boundary
>> 1872 protections.
2507 1873
2508 If unsure, say N. 1874 If unsure, say N.
2509 1875
2510 config TEST_BPF 1876 config TEST_BPF
2511 tristate "Test BPF filter functionali 1877 tristate "Test BPF filter functionality"
2512 depends on m && NET 1878 depends on m && NET
2513 help 1879 help
2514 This builds the "test_bpf" module t 1880 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 1881 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 1882 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 1883 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 1884 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 1885 verifier used by user space verifier testsuite.
2520 1886
2521 If unsure, say N. 1887 If unsure, say N.
2522 1888
2523 config TEST_BLACKHOLE_DEV <<
2524 tristate "Test blackhole netdev funct <<
2525 depends on m && NET <<
2526 help <<
2527 This builds the "test_blackhole_dev <<
2528 data path through this blackhole ne <<
2529 <<
2530 If unsure, say N. <<
2531 <<
2532 config FIND_BIT_BENCHMARK 1889 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 1890 tristate "Test find_bit functions"
2534 help 1891 help
2535 This builds the "test_find_bit" mod 1892 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 1893 functions performance.
2537 1894
2538 If unsure, say N. 1895 If unsure, say N.
2539 1896
2540 config TEST_FIRMWARE 1897 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 1898 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 1899 depends on FW_LOADER
2543 help 1900 help
2544 This builds the "test_firmware" mod 1901 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 1902 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 1903 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 1904 actual firmware-using device. The contents can be rechecked by
2548 userspace. 1905 userspace.
2549 1906
2550 If unsure, say N. 1907 If unsure, say N.
2551 1908
2552 config TEST_SYSCTL 1909 config TEST_SYSCTL
2553 tristate "sysctl test driver" 1910 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 1911 depends on PROC_SYSCTL
2555 help 1912 help
2556 This builds the "test_sysctl" modul 1913 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 1914 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 1915 production knobs which might alter system functionality.
2559 1916
2560 If unsure, say N. 1917 If unsure, say N.
2561 1918
2562 config BITFIELD_KUNIT <<
2563 tristate "KUnit test bitfield functio <<
2564 depends on KUNIT <<
2565 default KUNIT_ALL_TESTS <<
2566 help <<
2567 Enable this option to test the bitf <<
2568 <<
2569 KUnit tests run during boot and out <<
2570 in TAP format (http://testanything. <<
2571 running the KUnit test harness, and <<
2572 production build. <<
2573 <<
2574 For more information on KUnit and u <<
2575 to the KUnit documentation in Docum <<
2576 <<
2577 If unsure, say N. <<
2578 <<
2579 config CHECKSUM_KUNIT <<
2580 tristate "KUnit test checksum functio <<
2581 depends on KUNIT <<
2582 default KUNIT_ALL_TESTS <<
2583 help <<
2584 Enable this option to test the chec <<
2585 <<
2586 KUnit tests run during boot and out <<
2587 in TAP format (http://testanything. <<
2588 running the KUnit test harness, and <<
2589 production build. <<
2590 <<
2591 For more information on KUnit and u <<
2592 to the KUnit documentation in Docum <<
2593 <<
2594 If unsure, say N. <<
2595 <<
2596 config HASH_KUNIT_TEST <<
2597 tristate "KUnit Test for integer hash <<
2598 depends on KUNIT <<
2599 default KUNIT_ALL_TESTS <<
2600 help <<
2601 Enable this option to test the kern <<
2602 integer (<linux/hash.h>) hash funct <<
2603 <<
2604 KUnit tests run during boot and out <<
2605 in TAP format (https://testanything <<
2606 running the KUnit test harness, and <<
2607 production build. <<
2608 <<
2609 For more information on KUnit and u <<
2610 to the KUnit documentation in Docum <<
2611 <<
2612 This is intended to help people wri <<
2613 optimized versions. If unsure, say <<
2614 <<
2615 config RESOURCE_KUNIT_TEST <<
2616 tristate "KUnit test for resource API <<
2617 depends on KUNIT <<
2618 default KUNIT_ALL_TESTS <<
2619 help <<
2620 This builds the resource API unit t <<
2621 Tests the logic of API provided by <<
2622 For more information on KUnit and u <<
2623 to the KUnit documentation in Docum <<
2624 <<
2625 If unsure, say N. <<
2626 <<
2627 config SYSCTL_KUNIT_TEST <<
2628 tristate "KUnit test for sysctl" if ! <<
2629 depends on KUNIT <<
2630 default KUNIT_ALL_TESTS <<
2631 help <<
2632 This builds the proc sysctl unit te <<
2633 Tests the API contract and implemen <<
2634 For more information on KUnit and u <<
2635 to the KUnit documentation in Docum <<
2636 <<
2637 If unsure, say N. <<
2638 <<
2639 config LIST_KUNIT_TEST <<
2640 tristate "KUnit Test for Kernel Linke <<
2641 depends on KUNIT <<
2642 default KUNIT_ALL_TESTS <<
2643 help <<
2644 This builds the linked list KUnit t <<
2645 It tests that the API and basic fun <<
2646 and associated macros. <<
2647 <<
2648 KUnit tests run during boot and out <<
2649 in TAP format (https://testanything <<
2650 running the KUnit test harness, and <<
2651 production build. <<
2652 <<
2653 For more information on KUnit and u <<
2654 to the KUnit documentation in Docum <<
2655 <<
2656 If unsure, say N. <<
2657 <<
2658 config HASHTABLE_KUNIT_TEST <<
2659 tristate "KUnit Test for Kernel Hasht <<
2660 depends on KUNIT <<
2661 default KUNIT_ALL_TESTS <<
2662 help <<
2663 This builds the hashtable KUnit tes <<
2664 It tests the basic functionality of <<
2665 include/linux/hashtable.h. For more <<
2666 unit tests in general please refer <<
2667 in Documentation/dev-tools/kunit/. <<
2668 <<
2669 If unsure, say N. <<
2670 <<
2671 config LINEAR_RANGES_TEST <<
2672 tristate "KUnit test for linear_range <<
2673 depends on KUNIT <<
2674 select LINEAR_RANGES <<
2675 help <<
2676 This builds the linear_ranges unit <<
2677 Tests the linear_ranges logic corre <<
2678 For more information on KUnit and u <<
2679 to the KUnit documentation in Docum <<
2680 <<
2681 If unsure, say N. <<
2682 <<
2683 config CMDLINE_KUNIT_TEST <<
2684 tristate "KUnit test for cmdline API" <<
2685 depends on KUNIT <<
2686 default KUNIT_ALL_TESTS <<
2687 help <<
2688 This builds the cmdline API unit te <<
2689 Tests the logic of API provided by <<
2690 For more information on KUnit and u <<
2691 to the KUnit documentation in Docum <<
2692 <<
2693 If unsure, say N. <<
2694 <<
2695 config BITS_TEST <<
2696 tristate "KUnit test for bits.h" if ! <<
2697 depends on KUNIT <<
2698 default KUNIT_ALL_TESTS <<
2699 help <<
2700 This builds the bits unit test. <<
2701 Tests the logic of macros defined i <<
2702 For more information on KUnit and u <<
2703 to the KUnit documentation in Docum <<
2704 <<
2705 If unsure, say N. <<
2706 <<
2707 config SLUB_KUNIT_TEST <<
2708 tristate "KUnit test for SLUB cache e <<
2709 depends on SLUB_DEBUG && KUNIT <<
2710 default KUNIT_ALL_TESTS <<
2711 help <<
2712 This builds SLUB allocator unit tes <<
2713 Tests SLUB cache debugging function <<
2714 For more information on KUnit and u <<
2715 to the KUnit documentation in Docum <<
2716 <<
2717 If unsure, say N. <<
2718 <<
2719 config RATIONAL_KUNIT_TEST <<
2720 tristate "KUnit test for rational.c" <<
2721 depends on KUNIT && RATIONAL <<
2722 default KUNIT_ALL_TESTS <<
2723 help <<
2724 This builds the rational math unit <<
2725 For more information on KUnit and u <<
2726 to the KUnit documentation in Docum <<
2727 <<
2728 If unsure, say N. <<
2729 <<
2730 config MEMCPY_KUNIT_TEST <<
2731 tristate "Test memcpy(), memmove(), a <<
2732 depends on KUNIT <<
2733 default KUNIT_ALL_TESTS <<
2734 help <<
2735 Builds unit tests for memcpy(), mem <<
2736 For more information on KUnit and u <<
2737 to the KUnit documentation in Docum <<
2738 <<
2739 If unsure, say N. <<
2740 <<
2741 config IS_SIGNED_TYPE_KUNIT_TEST <<
2742 tristate "Test is_signed_type() macro <<
2743 depends on KUNIT <<
2744 default KUNIT_ALL_TESTS <<
2745 help <<
2746 Builds unit tests for the is_signed <<
2747 <<
2748 For more information on KUnit and u <<
2749 to the KUnit documentation in Docum <<
2750 <<
2751 If unsure, say N. <<
2752 <<
2753 config OVERFLOW_KUNIT_TEST <<
2754 tristate "Test check_*_overflow() fun <<
2755 depends on KUNIT <<
2756 default KUNIT_ALL_TESTS <<
2757 help <<
2758 Builds unit tests for the check_*_o <<
2759 related functions. <<
2760 <<
2761 For more information on KUnit and u <<
2762 to the KUnit documentation in Docum <<
2763 <<
2764 If unsure, say N. <<
2765 <<
2766 config STACKINIT_KUNIT_TEST <<
2767 tristate "Test level of stack variabl <<
2768 depends on KUNIT <<
2769 default KUNIT_ALL_TESTS <<
2770 help <<
2771 Test if the kernel is zero-initiali <<
2772 padding. Coverage is controlled by <<
2773 CONFIG_INIT_STACK_ALL_PATTERN, CONF <<
2774 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFI <<
2775 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYR <<
2776 <<
2777 config FORTIFY_KUNIT_TEST <<
2778 tristate "Test fortified str*() and m <<
2779 depends on KUNIT <<
2780 default KUNIT_ALL_TESTS <<
2781 help <<
2782 Builds unit tests for checking inte <<
2783 by the str*() and mem*() family of <<
2784 traps of FORTIFY_SOURCE, see LKDTM' <<
2785 <<
2786 config HW_BREAKPOINT_KUNIT_TEST <<
2787 bool "Test hw_breakpoint constraints <<
2788 depends on HAVE_HW_BREAKPOINT <<
2789 depends on KUNIT=y <<
2790 default KUNIT_ALL_TESTS <<
2791 help <<
2792 Tests for hw_breakpoint constraints <<
2793 <<
2794 If unsure, say N. <<
2795 <<
2796 config SIPHASH_KUNIT_TEST <<
2797 tristate "Perform selftest on siphash <<
2798 depends on KUNIT <<
2799 default KUNIT_ALL_TESTS <<
2800 help <<
2801 Enable this option to test the kern <<
2802 functions on boot (or module load). <<
2803 <<
2804 This is intended to help people wri <<
2805 optimized versions. If unsure, say <<
2806 <<
2807 config USERCOPY_KUNIT_TEST <<
2808 tristate "KUnit Test for user/kernel <<
2809 depends on KUNIT <<
2810 default KUNIT_ALL_TESTS <<
2811 help <<
2812 This builds the "usercopy_kunit" mo <<
2813 on the copy_to/from_user infrastruc <<
2814 user/kernel boundary testing is wor <<
2815 <<
2816 config TEST_UDELAY 1919 config TEST_UDELAY
2817 tristate "udelay test driver" 1920 tristate "udelay test driver"
2818 help 1921 help
2819 This builds the "udelay_test" modul 1922 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 1923 that udelay() is working properly.
2821 1924
2822 If unsure, say N. 1925 If unsure, say N.
2823 1926
2824 config TEST_STATIC_KEYS 1927 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 1928 tristate "Test static keys"
2826 depends on m 1929 depends on m
2827 help 1930 help
2828 Test the static key interfaces. 1931 Test the static key interfaces.
2829 1932
2830 If unsure, say N. 1933 If unsure, say N.
2831 1934
2832 config TEST_DYNAMIC_DEBUG <<
2833 tristate "Test DYNAMIC_DEBUG" <<
2834 depends on DYNAMIC_DEBUG <<
2835 help <<
2836 This module registers a tracer call <<
2837 pr_debugs in a 'do_debugging' funct <<
2838 enablements, calls the function, an <<
2839 <<
2840 If unsure, say N. <<
2841 <<
2842 config TEST_KMOD 1935 config TEST_KMOD
2843 tristate "kmod stress tester" 1936 tristate "kmod stress tester"
2844 depends on m 1937 depends on m
>> 1938 depends on BLOCK && (64BIT || LBDAF) # for XFS, BTRFS
2845 depends on NETDEVICES && NET_CORE && 1939 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK <<
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 1940 select TEST_LKM
2849 select XFS_FS 1941 select XFS_FS
2850 select TUN 1942 select TUN
2851 select BTRFS_FS 1943 select BTRFS_FS
2852 help 1944 help
2853 Test the kernel's module loading me 1945 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 1946 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 1947 This test provides a series of tests against kmod.
2856 1948
2857 Although technically you can either 1949 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 1950 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 1951 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 1952 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 1953 module load requests, ultimately this could be fatal.
2862 1954
2863 To run tests run: 1955 To run tests run:
2864 1956
2865 tools/testing/selftests/kmod/kmod.s 1957 tools/testing/selftests/kmod/kmod.sh --help
2866 1958
2867 If unsure, say N. 1959 If unsure, say N.
2868 1960
2869 config TEST_DEBUG_VIRTUAL 1961 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 1962 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 1963 depends on DEBUG_VIRTUAL
2872 help 1964 help
2873 Test the kernel's ability to detect 1965 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 1966 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 1967 kernel's virtual address map.
2876 1968
2877 If unsure, say N. 1969 If unsure, say N.
2878 1970
2879 config TEST_MEMCAT_P 1971 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 1972 tristate "Test memcat_p() helper function"
2881 help 1973 help
2882 Test the memcat_p() helper for corr 1974 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 1975 pointer arrays together.
2884 1976
2885 If unsure, say N. 1977 If unsure, say N.
2886 1978
2887 config TEST_OBJAGG <<
2888 tristate "Perform selftest on object <<
2889 default n <<
2890 depends on OBJAGG <<
2891 help <<
2892 Enable this option to test object a <<
2893 (or module load). <<
2894 <<
2895 config TEST_MEMINIT <<
2896 tristate "Test heap/page initializati <<
2897 help <<
2898 Test if the kernel is zero-initiali <<
2899 This can be useful to test init_on_ <<
2900 <<
2901 If unsure, say N. <<
2902 <<
2903 config TEST_HMM <<
2904 tristate "Test HMM (Heterogeneous Mem <<
2905 depends on TRANSPARENT_HUGEPAGE <<
2906 depends on DEVICE_PRIVATE <<
2907 select HMM_MIRROR <<
2908 select MMU_NOTIFIER <<
2909 help <<
2910 This is a pseudo device driver sole <<
2911 Say M here if you want to build the <<
2912 Doing so will allow you to run tool <<
2913 <<
2914 If unsure, say N. <<
2915 <<
2916 config TEST_FREE_PAGES <<
2917 tristate "Test freeing pages" <<
2918 help <<
2919 Test that a memory leak does not oc <<
2920 freeing a block of pages and a spec <<
2921 Loading this module is safe if your <<
2922 If the bug is not fixed, it will le <<
2923 probably OOM your system. <<
2924 <<
2925 config TEST_FPU <<
2926 tristate "Test floating point operati <<
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR <<
2928 help <<
2929 Enable this option to add /sys/kern <<
2930 which will trigger a sequence of fl <<
2931 for self-testing floating point con <<
2932 kernel_fpu_begin(). <<
2933 <<
2934 If unsure, say N. <<
2935 <<
2936 config TEST_CLOCKSOURCE_WATCHDOG <<
2937 tristate "Test clocksource watchdog i <<
2938 depends on CLOCKSOURCE_WATCHDOG <<
2939 help <<
2940 Enable this option to create a kern <<
2941 a test of the clocksource watchdog. <<
2942 via modprobe or insmod in which cas <<
2943 loaded, or it may be built in, in w <<
2944 shortly after boot. <<
2945 <<
2946 If unsure, say N. <<
2947 <<
2948 config TEST_OBJPOOL <<
2949 tristate "Test module for correctness <<
2950 default n <<
2951 depends on m && DEBUG_KERNEL <<
2952 help <<
2953 This builds the "test_objpool" modu <<
2954 correctness verification and concur <<
2955 allocation and reclamation. <<
2956 <<
2957 If unsure, say N. <<
2958 <<
2959 endif # RUNTIME_TESTING_MENU 1979 endif # RUNTIME_TESTING_MENU
2960 1980
2961 config ARCH_USE_MEMTEST <<
2962 bool <<
2963 help <<
2964 An architecture should select this <<
2965 during boot process. <<
2966 <<
2967 config MEMTEST 1981 config MEMTEST
2968 bool "Memtest" 1982 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST !! 1983 ---help---
2970 help <<
2971 This option adds a kernel parameter 1984 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. !! 1985 to be set.
2973 memtest=0, mean disabled; -- 1986 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 1987 memtest=1, mean do 1 test pattern;
2975 ... 1988 ...
2976 memtest=17, mean do 17 test p 1989 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 1990 If you are unsure how to answer this question, answer N.
2978 1991
2979 !! 1992 config BUG_ON_DATA_CORRUPTION
2980 !! 1993 bool "Trigger a BUG when data corruption is detected"
2981 config HYPERV_TESTING !! 1994 select DEBUG_LIST
2982 bool "Microsoft Hyper-V driver testin !! 1995 help
2983 default n !! 1996 Select this option if the kernel should BUG when it encounters
2984 depends on HYPERV && DEBUG_FS !! 1997 data corruption in kernel memory structures when they get checked
2985 help !! 1998 for validity.
2986 Select this option to enable Hyper- <<
2987 <<
2988 endmenu # "Kernel Testing and Coverage" <<
2989 <<
2990 menu "Rust hacking" <<
2991 <<
2992 config RUST_DEBUG_ASSERTIONS <<
2993 bool "Debug assertions" <<
2994 depends on RUST <<
2995 help <<
2996 Enables rustc's `-Cdebug-assertions <<
2997 <<
2998 This flag lets you turn `cfg(debug_ <<
2999 compilation on or off. This can be <<
3000 code in development but not in prod <<
3001 the behavior of the standard librar <<
3002 <<
3003 Note that this will apply to all Ru <<
3004 1999
3005 If unsure, say N. 2000 If unsure, say N.
3006 2001
3007 config RUST_OVERFLOW_CHECKS !! 2002 source "samples/Kconfig"
3008 bool "Overflow checks" <<
3009 default y <<
3010 depends on RUST <<
3011 help <<
3012 Enables rustc's `-Coverflow-checks` <<
3013 <<
3014 This flag allows you to control the <<
3015 overflow. When overflow-checks are <<
3016 on overflow. <<
3017 2003
3018 Note that this will apply to all Ru !! 2004 source "lib/Kconfig.kgdb"
3019 2005
3020 If unsure, say Y. !! 2006 source "lib/Kconfig.ubsan"
3021 2007
3022 config RUST_BUILD_ASSERT_ALLOW !! 2008 config ARCH_HAS_DEVMEM_IS_ALLOWED
3023 bool "Allow unoptimized build-time as !! 2009 bool
3024 depends on RUST <<
3025 help <<
3026 Controls how are `build_error!` and <<
3027 2010
3028 If calls to them exist in the binar !! 2011 config STRICT_DEVMEM
3029 or that the optimizer failed to ver !! 2012 bool "Filter access to /dev/mem"
>> 2013 depends on MMU && DEVMEM
>> 2014 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
>> 2015 default y if PPC || X86 || ARM64
>> 2016 ---help---
>> 2017 If this option is disabled, you allow userspace (root) access to all
>> 2018 of memory, including kernel and userspace memory. Accidental
>> 2019 access to this is obviously disastrous, but specific access can
>> 2020 be used by people debugging the kernel. Note that with PAT support
>> 2021 enabled, even in this case there are restrictions on /dev/mem
>> 2022 use due to the cache aliasing requirements.
3030 2023
3031 This should not happen, thus by def !! 2024 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
3032 as an escape hatch, you can choose !! 2025 file only allows userspace access to PCI space and the BIOS code and
3033 and let the check be carried at run !! 2026 data regions. This is sufficient for dosemu and X and all common
3034 the check fails). !! 2027 users of /dev/mem.
3035 2028
3036 If unsure, say N. !! 2029 If in doubt, say Y.
3037 2030
3038 config RUST_KERNEL_DOCTESTS !! 2031 config IO_STRICT_DEVMEM
3039 bool "Doctests for the `kernel` crate !! 2032 bool "Filter I/O access to /dev/mem"
3040 depends on RUST && KUNIT=y !! 2033 depends on STRICT_DEVMEM
3041 default KUNIT_ALL_TESTS !! 2034 ---help---
3042 help !! 2035 If this option is disabled, you allow userspace (root) access to all
3043 This builds the documentation tests !! 2036 io-memory regardless of whether a driver is actively using that
3044 as KUnit tests. !! 2037 range. Accidental access to this is obviously disastrous, but
>> 2038 specific access can be used by people debugging kernel drivers.
3045 2039
3046 For more information on KUnit and u !! 2040 If this option is switched on, the /dev/mem file only allows
3047 please refer to the KUnit documenta !! 2041 userspace access to *idle* io-memory ranges (see /proc/iomem) This
>> 2042 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
>> 2043 if the driver using a given range cannot be disabled.
3048 2044
3049 If unsure, say N. !! 2045 If in doubt, say Y.
3050 2046
3051 endmenu # "Rust" !! 2047 source "arch/$(SRCARCH)/Kconfig.debug"
3052 2048
3053 endmenu # Kernel hacking 2049 endmenu # Kernel hacking
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