1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 menu "Kernel hacking" 2 menu "Kernel hacking"
3 3
4 menu "printk and dmesg options" 4 menu "printk and dmesg options"
5 5
6 config PRINTK_TIME 6 config PRINTK_TIME
7 bool "Show timing information on print 7 bool "Show timing information on printks"
8 depends on PRINTK 8 depends on PRINTK
9 help 9 help
10 Selecting this option causes time st 10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output o 11 messages to be added to the output of the syslog() system
12 call and at the console. 12 call and at the console.
13 13
14 The timestamp is always recorded int 14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifi 15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp 16 be included, not that the timestamp is recorded.
17 17
18 The behavior is also controlled by t 18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documen 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
20 20
21 config PRINTK_CALLER 21 config PRINTK_CALLER
22 bool "Show caller information on print 22 bool "Show caller information on printks"
23 depends on PRINTK 23 depends on PRINTK
24 help 24 help
25 Selecting this option causes printk( 25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "proces 26 in task context) or a caller "processor id" (if not in task context)
27 to every message. 27 to every message.
28 28
29 This option is intended for environm 29 This option is intended for environments where multiple threads
30 concurrently call printk() for many 30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where thes 31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple 32 line which was divided into multiple lines due to race) came from.
33 33
34 Since toggling after boot makes the 34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the k 35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface. 36 sysfs interface.
37 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 38 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)" 39 int "Default console loglevel (1-15)"
51 range 1 15 40 range 1 15
52 default "7" 41 default "7"
53 help 42 help
54 Default loglevel to determine what w 43 Default loglevel to determine what will be printed on the console.
55 44
56 Setting a default here is equivalent 45 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> co 46 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well. 47 value is specified here as well.
59 48
60 Note: This does not affect the log l 49 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is control 50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option. 51 option.
63 52
64 config CONSOLE_LOGLEVEL_QUIET 53 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)" 54 int "quiet console loglevel (1-15)"
66 range 1 15 55 range 1 15
67 default "4" 56 default "4"
68 help 57 help
69 loglevel to use when "quiet" is pass 58 loglevel to use when "quiet" is passed on the kernel commandline.
70 59
71 When "quiet" is passed on the kernel 60 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW pa 61 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CON 62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74 63
75 config MESSAGE_LOGLEVEL_DEFAULT 64 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)" 65 int "Default message log level (1-7)"
77 range 1 7 66 range 1 7
78 default "4" 67 default "4"
79 help 68 help
80 Default log level for printk stateme 69 Default log level for printk statements with no specified priority.
81 70
82 This was hard-coded to KERN_WARNING 71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely 72 that are auditing their logs closely may want to set it to a lower
84 priority. 73 priority.
85 74
86 Note: This does not affect what mess 75 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use logl 76 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL 77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89 78
90 config BOOT_PRINTK_DELAY 79 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message b 80 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && G 81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help 82 help
94 This build option allows you to read 83 This build option allows you to read kernel boot messages
95 by inserting a short delay after eac 84 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the ker 85 specified in milliseconds on the kernel command line,
97 using "boot_delay=N". 86 using "boot_delay=N".
98 87
99 It is likely that you would also nee 88 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value. 89 the "loops per jiffie" value.
101 See a previous boot log for the "lpj 90 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before 91 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adverse 92 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the firs 93 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOC 94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup condit 95 what it believes to be lockup conditions.
107 96
108 config DYNAMIC_DEBUG 97 config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support" 98 bool "Enable dynamic printk() support"
110 default n 99 default n
111 depends on PRINTK 100 depends on PRINTK
112 depends on (DEBUG_FS || PROC_FS) !! 101 depends on DEBUG_FS
113 select DYNAMIC_DEBUG_CORE <<
114 help 102 help
115 103
116 Compiles debug level messages into t 104 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 105 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 106 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 107 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 108 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 109 enlarges the kernel text size by about 2%.
122 110
123 If a source file is compiled with DE 111 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 112 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 113 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 114 turned on by many CONFIG_*DEBUG* options.
127 115
128 Usage: 116 Usage:
129 117
130 Dynamic debugging is controlled via 118 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' !! 119 which is contained in the 'debugfs' filesystem. Thus, the debugfs
132 Thus, the debugfs or procfs filesyst !! 120 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 121 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 122 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 123 format for each line of the file is:
137 124
138 filename:lineno [module]functi 125 filename:lineno [module]function flags format
139 126
140 filename : source file of the debug 127 filename : source file of the debug statement
141 lineno : line number of the debug st 128 lineno : line number of the debug statement
142 module : module that contains the de 129 module : module that contains the debug statement
143 function : function that contains th 130 function : function that contains the debug statement
144 flags : '=p' means the line is turne !! 131 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb !! 132 format : the format used for the debug statement
146 133
147 From a live system: 134 From a live system:
148 135
149 nullarbor:~ # cat <debugfs>/dy 136 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 137 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 138 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 139 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 140 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 141
155 Example usage: 142 Example usage:
156 143
157 // enable the message at line 144 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 145 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 146 <debugfs>/dynamic_debug/control
160 147
161 // enable all the messages in 148 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 149 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 150 <debugfs>/dynamic_debug/control
164 151
165 // enable all the messages in 152 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 153 nullarbor:~ # echo -n 'module nfsd +p' >
167 154 <debugfs>/dynamic_debug/control
168 155
169 // enable all 12 messages in t 156 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 157 nullarbor:~ # echo -n 'func svc_process +p' >
171 158 <debugfs>/dynamic_debug/control
172 159
173 // disable all 12 messages in 160 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 161 nullarbor:~ # echo -n 'func svc_process -p' >
175 162 <debugfs>/dynamic_debug/control
176 163
177 See Documentation/admin-guide/dynami 164 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 165 information.
179 166
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" 167 endmenu # "printk and dmesg options"
210 168
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 169 menu "Compile-time checks and compiler options"
226 170
227 config DEBUG_INFO 171 config DEBUG_INFO
228 bool !! 172 bool "Compile the kernel with debug info"
>> 173 depends on DEBUG_KERNEL && !COMPILE_TEST
229 help 174 help
230 A kernel debug info option other tha !! 175 If you say Y here the resulting kernel image will include
231 in the "Debug information" choice be !! 176 debugging info resulting in a larger kernel image.
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 <<
244 Selecting something other than "None <<
245 that will include debugging info res <<
246 This adds debug symbols to the kerne 177 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 178 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 179 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
>> 180 Say Y here only if you plan to debug the kernel.
249 181
250 Choose which version of DWARF debug !! 182 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 <<
304 183
305 config DEBUG_INFO_REDUCED 184 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 185 bool "Reduce debugging information"
>> 186 depends on DEBUG_INFO
307 help 187 help
308 If you say Y here gcc is instructed 188 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 189 information for structure types. This means that tools that
310 need full debugging information (lik 190 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 191 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 192 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 193 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 194 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 195 Only works with newer gcc versions.
316 196
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 197 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 198 bool "Produce split debuginfo in .dwo files"
>> 199 depends on DEBUG_INFO
359 depends on $(cc-option,-gsplit-dwarf) 200 depends on $(cc-option,-gsplit-dwarf)
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 201 help
366 Generate debug info into separate .d 202 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 203 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 204 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 205 files instead of multiple times in object files and executables.
370 In addition the debug information is 206 In addition the debug information is also compressed.
371 207
372 Requires recent gcc (4.7+) and recen 208 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 209 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 210 to know about the .dwo files and include them.
375 Incompatible with older versions of 211 Incompatible with older versions of ccache.
376 212
>> 213 config DEBUG_INFO_DWARF4
>> 214 bool "Generate dwarf4 debuginfo"
>> 215 depends on DEBUG_INFO
>> 216 depends on $(cc-option,-gdwarf-4)
>> 217 help
>> 218 Generate dwarf4 debug info. This requires recent versions
>> 219 of gcc and gdb. It makes the debug information larger.
>> 220 But it significantly improves the success of resolving
>> 221 variables in gdb on optimized code.
>> 222
377 config DEBUG_INFO_BTF 223 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 224 bool "Generate BTF typeinfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG !! 225 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 226 help
386 Generate deduplicated BTF type infor 227 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 228 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 229 DWARF type info into equivalent deduplicated BTF type info.
389 230
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 <<
415 Generate compact split BTF type info <<
416 <<
417 config MODULE_ALLOW_BTF_MISMATCH <<
418 bool "Allow loading modules with non-m <<
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 <<
427 config GDB_SCRIPTS 231 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 232 bool "Provide GDB scripts for kernel debugging"
>> 233 depends on DEBUG_INFO
429 help 234 help
430 This creates the required links to G 235 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 236 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 237 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 238 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 239 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 240 for further details.
436 241
437 endif # DEBUG_INFO !! 242 config ENABLE_MUST_CHECK
>> 243 bool "Enable __must_check logic"
>> 244 default y
>> 245 help
>> 246 Enable the __must_check logic in the kernel build. Disable this to
>> 247 suppress the "warning: ignoring return value of 'foo', declared with
>> 248 attribute warn_unused_result" messages.
438 249
439 config FRAME_WARN 250 config FRAME_WARN
440 int "Warn for stack frames larger than !! 251 int "Warn for stack frames larger than (needs gcc 4.4)"
441 range 0 8192 252 range 0 8192
442 default 0 if KMSAN <<
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 253 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC !! 254 default 1280 if (!64BIT && PARISC)
445 default 1536 if (!64BIT && XTENSA) !! 255 default 1024 if (!64BIT && !PARISC)
446 default 1280 if KASAN && !64BIT <<
447 default 1024 if !64BIT <<
448 default 2048 if 64BIT 256 default 2048 if 64BIT
449 help 257 help
450 Tell the compiler to warn at build t !! 258 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 259 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 260 Setting it to 0 disables the warning.
>> 261 Requires gcc 4.4
453 262
454 config STRIP_ASM_SYMS 263 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 264 bool "Strip assembler-generated symbols during link"
456 default n 265 default n
457 help 266 help
458 Strip internal assembler-generated s 267 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 268 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 269 get_wchan() and suchlike.
461 270
462 config READABLE_ASM 271 config READABLE_ASM
463 bool "Generate readable assembler code !! 272 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL !! 273 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC !! 274 help
>> 275 Disable some compiler optimizations that tend to generate human unreadable
>> 276 assembler output. This may make the kernel slightly slower, but it helps
>> 277 to keep kernel developers who have to stare a lot at assembler listings
>> 278 sane.
>> 279
>> 280 config UNUSED_SYMBOLS
>> 281 bool "Enable unused/obsolete exported symbols"
>> 282 default y if X86
>> 283 help
>> 284 Unused but exported symbols make the kernel needlessly bigger. For
>> 285 that reason most of these unused exports will soon be removed. This
>> 286 option is provided temporarily to provide a transition period in case
>> 287 some external kernel module needs one of these symbols anyway. If you
>> 288 encounter such a case in your module, consider if you are actually
>> 289 using the right API. (rationale: since nobody in the kernel is using
>> 290 this in a module, there is a pretty good chance it's actually the
>> 291 wrong interface to use). If you really need the symbol, please send a
>> 292 mail to the linux kernel mailing list mentioning the symbol and why
>> 293 you really need it, and what the merge plan to the mainline kernel for
>> 294 your module is.
>> 295
>> 296 config DEBUG_FS
>> 297 bool "Debug Filesystem"
466 help 298 help
467 Disable some compiler optimizations !! 299 debugfs is a virtual file system that kernel developers use to put
468 assembler output. This may make the !! 300 debugging files into. Enable this option to be able to read and
469 to keep kernel developers who have t !! 301 write to these files.
470 sane. <<
471 302
472 config HEADERS_INSTALL !! 303 For detailed documentation on the debugfs API, see
473 bool "Install uapi headers to usr/incl !! 304 Documentation/filesystems/.
>> 305
>> 306 If unsure, say N.
>> 307
>> 308 config HEADERS_CHECK
>> 309 bool "Run 'make headers_check' when building vmlinux"
474 depends on !UML 310 depends on !UML
475 help 311 help
476 This option will install uapi header !! 312 This option will extract the user-visible kernel headers whenever
477 into the usr/include directory for u !! 313 building the kernel, and will run basic sanity checks on them to
478 This is unneeded for building the ke !! 314 ensure that exported files do not attempt to include files which
479 user-space program samples. It is al !! 315 were not exported, etc.
480 as uapi header sanity checks. !! 316
>> 317 If you're making modifications to header files which are
>> 318 relevant for userspace, say 'Y', and check the headers
>> 319 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
>> 320 your build tree), to make sure they're suitable.
>> 321
>> 322 config OPTIMIZE_INLINING
>> 323 bool "Allow compiler to uninline functions marked 'inline'"
>> 324 help
>> 325 This option determines if the kernel forces gcc to inline the functions
>> 326 developers have marked 'inline'. Doing so takes away freedom from gcc to
>> 327 do what it thinks is best, which is desirable for the gcc 3.x series of
>> 328 compilers. The gcc 4.x series have a rewritten inlining algorithm and
>> 329 enabling this option will generate a smaller kernel there. Hopefully
>> 330 this algorithm is so good that allowing gcc 4.x and above to make the
>> 331 decision will become the default in the future. Until then this option
>> 332 is there to test gcc for this.
>> 333
>> 334 If unsure, say N.
481 335
482 config DEBUG_SECTION_MISMATCH 336 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 337 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 338 help
486 The section mismatch analysis checks 339 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 340 references from one section to another section.
488 During linktime or runtime, some sec 341 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 342 any use of code/data previously in these sections would
490 most likely result in an oops. 343 most likely result in an oops.
491 In the code, functions and variables 344 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 345 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 346 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 347 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 348 kernel build, and enabling this option causes the following
496 additional step to occur: !! 349 additional steps to occur:
497 - Add the option -fno-inline-functio 350 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 351 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 352 function, we would lose the section information and thus
500 the analysis would not catch the i 353 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 354 This option tells gcc to inline less (but it does result in
502 a larger kernel). 355 a larger kernel).
>> 356 - Run the section mismatch analysis for each module/built-in.a file.
>> 357 When we run the section mismatch analysis on vmlinux.o, we
>> 358 lose valuable information about where the mismatch was
>> 359 introduced.
>> 360 Running the analysis for each module/built-in.a file
>> 361 tells where the mismatch happens much closer to the
>> 362 source. The drawback is that the same mismatch is
>> 363 reported at least twice.
>> 364 - Enable verbose reporting from modpost in order to help resolve
>> 365 the section mismatches that are reported.
503 366
504 config SECTION_MISMATCH_WARN_ONLY 367 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 368 bool "Make section mismatch errors non-fatal"
506 default y 369 default y
507 help 370 help
508 If you say N here, the build process 371 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 372 section mismatch, instead of just throwing warnings.
510 373
511 If unsure, say Y. 374 If unsure, say Y.
512 375
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 # 376 #
527 # Select this config option from the architect 377 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 378 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 379 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 380 #
531 config ARCH_WANT_FRAME_POINTERS 381 config ARCH_WANT_FRAME_POINTERS
532 bool 382 bool
533 383
534 config FRAME_POINTER 384 config FRAME_POINTER
535 bool "Compile the kernel with frame po 385 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 386 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 387 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 388 help
539 If you say Y here the resulting kern 389 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 390 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 391 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 392
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 393 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 394 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 395 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 396 default n
551 help 397 help
552 Validate frame pointer rules at comp !! 398 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 399 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 400 that runtime stack traces are more reliable.
554 401
555 For more information, see !! 402 This is also a prerequisite for generation of ORC unwind data, which
556 tools/objtool/Documentation/objtool. !! 403 is needed for CONFIG_UNWINDER_ORC.
557 <<
558 config NOINSTR_VALIDATION <<
559 bool <<
560 depends on HAVE_NOINSTR_VALIDATION && <<
561 select OBJTOOL <<
562 default y <<
563 404
564 config VMLINUX_MAP !! 405 For more information, see
565 bool "Generate vmlinux.map file when l !! 406 tools/objtool/Documentation/stack-validation.txt.
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 <<
573 407
574 config DEBUG_FORCE_WEAK_PER_CPU 408 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 409 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 410 depends on DEBUG_KERNEL
577 help 411 help
578 s390 and alpha require percpu variab 412 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 413 defined weak to work around addressing range issue which
580 puts the following two restrictions 414 puts the following two restrictions on percpu variable
581 definitions. 415 definitions.
582 416
583 1. percpu symbols must be unique whe 417 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 418 2. percpu variables can't be defined inside a function
585 419
586 To ensure that generic code follows 420 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 421 option forces all percpu variables to be defined as weak.
588 422
589 endmenu # "Compiler options" 423 endmenu # "Compiler options"
590 424
591 menu "Generic Kernel Debugging Instruments" <<
592 <<
593 config MAGIC_SYSRQ 425 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 426 bool "Magic SysRq key"
595 depends on !UML 427 depends on !UML
596 help 428 help
597 If you say Y here, you will have som 429 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 430 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 431 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 432 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 433 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 434 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 435 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 436 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 437 Don't say Y unless you really know what this hack does.
606 438
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 439 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 440 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 441 depends on MAGIC_SYSRQ
610 default 0x1 442 default 0x1
611 help 443 help
612 Specifies which SysRq key functions 444 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 445 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 446 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 447
616 config MAGIC_SYSRQ_SERIAL 448 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 449 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 450 depends on MAGIC_SYSRQ
619 default y 451 default y
620 help 452 help
621 Many embedded boards have a disconne 453 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 454 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 455 This option allows you to decide whether you want to enable the
624 magic SysRq key. 456 magic SysRq key.
625 457
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE !! 458 config DEBUG_KERNEL
627 string "Char sequence that enables mag !! 459 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 460 help
667 The API is open but filesystem is no !! 461 Say Y here if you are developing drivers or trying to debug and
668 their work and read with debug tools !! 462 identify kernel problems.
669 debugfs filesystem. <<
670 463
671 config DEBUG_FS_ALLOW_NONE !! 464 config DEBUG_MISC
672 bool "No access" !! 465 bool "Miscellaneous debug code"
>> 466 default DEBUG_KERNEL
>> 467 depends on DEBUG_KERNEL
673 help 468 help
674 Access is off. Clients get -PERM whe !! 469 Say Y here if you need to enable miscellaneous debug code that should
675 debugfs tree and debugfs is not regi !! 470 be under a more specific debug option but isn't.
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" <<
689 471
690 endmenu # "Networking Debugging" <<
691 472
692 menu "Memory Debugging" 473 menu "Memory Debugging"
693 474
694 source "mm/Kconfig.debug" 475 source "mm/Kconfig.debug"
695 476
696 config DEBUG_OBJECTS 477 config DEBUG_OBJECTS
697 bool "Debug object operations" 478 bool "Debug object operations"
698 depends on DEBUG_KERNEL 479 depends on DEBUG_KERNEL
699 help 480 help
700 If you say Y here, additional code w 481 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 482 kernel to track the life time of various objects and validate
702 the operations on those objects. 483 the operations on those objects.
703 484
704 config DEBUG_OBJECTS_SELFTEST 485 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 486 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 487 depends on DEBUG_OBJECTS
707 help 488 help
708 This enables the selftest of the obj 489 This enables the selftest of the object debug code.
709 490
710 config DEBUG_OBJECTS_FREE 491 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 492 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 493 depends on DEBUG_OBJECTS
713 help 494 help
714 This enables checks whether a k/v fr 495 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 496 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 497 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 498 much slower.
718 499
719 config DEBUG_OBJECTS_TIMERS 500 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 501 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 502 depends on DEBUG_OBJECTS
722 help 503 help
723 If you say Y here, additional code w 504 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 505 timer routines to track the life time of timer objects and
725 validate the timer operations. 506 validate the timer operations.
726 507
727 config DEBUG_OBJECTS_WORK 508 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 509 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 510 depends on DEBUG_OBJECTS
730 help 511 help
731 If you say Y here, additional code w 512 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 513 work queue routines to track the life time of work objects and
733 validate the work operations. 514 validate the work operations.
734 515
735 config DEBUG_OBJECTS_RCU_HEAD 516 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 517 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 518 depends on DEBUG_OBJECTS
738 help 519 help
739 Enable this to turn on debugging of 520 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 521
741 config DEBUG_OBJECTS_PERCPU_COUNTER 522 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 523 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 524 depends on DEBUG_OBJECTS
744 help 525 help
745 If you say Y here, additional code w 526 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 527 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 528 objects and validate the percpu counter operations.
748 529
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 530 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 531 int "debug_objects bootup default value (0-1)"
751 range 0 1 !! 532 range 0 1
752 default "1" !! 533 default "1"
753 depends on DEBUG_OBJECTS !! 534 depends on DEBUG_OBJECTS
>> 535 help
>> 536 Debug objects boot parameter default value
>> 537
>> 538 config DEBUG_SLAB
>> 539 bool "Debug slab memory allocations"
>> 540 depends on DEBUG_KERNEL && SLAB
>> 541 help
>> 542 Say Y here to have the kernel do limited verification on memory
>> 543 allocation as well as poisoning memory on free to catch use of freed
>> 544 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 545
>> 546 config SLUB_DEBUG_ON
>> 547 bool "SLUB debugging on by default"
>> 548 depends on SLUB && SLUB_DEBUG
>> 549 default n
>> 550 help
>> 551 Boot with debugging on by default. SLUB boots by default with
>> 552 the runtime debug capabilities switched off. Enabling this is
>> 553 equivalent to specifying the "slub_debug" parameter on boot.
>> 554 There is no support for more fine grained debug control like
>> 555 possible with slub_debug=xxx. SLUB debugging may be switched
>> 556 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 557 "slub_debug=-".
>> 558
>> 559 config SLUB_STATS
>> 560 default n
>> 561 bool "Enable SLUB performance statistics"
>> 562 depends on SLUB && SYSFS
>> 563 help
>> 564 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 565 order find ways to optimize the allocator. This should never be
>> 566 enabled for production use since keeping statistics slows down
>> 567 the allocator by a few percentage points. The slabinfo command
>> 568 supports the determination of the most active slabs to figure
>> 569 out which slabs are relevant to a particular load.
>> 570 Try running: slabinfo -DA
>> 571
>> 572 config HAVE_DEBUG_KMEMLEAK
>> 573 bool
>> 574
>> 575 config DEBUG_KMEMLEAK
>> 576 bool "Kernel memory leak detector"
>> 577 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 578 select DEBUG_FS
>> 579 select STACKTRACE if STACKTRACE_SUPPORT
>> 580 select KALLSYMS
>> 581 select CRC32
754 help 582 help
755 Debug objects boot parameter default !! 583 Say Y here if you want to enable the memory leak
>> 584 detector. The memory allocation/freeing is traced in a way
>> 585 similar to the Boehm's conservative garbage collector, the
>> 586 difference being that the orphan objects are not freed but
>> 587 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 588 feature will introduce an overhead to memory
>> 589 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 590 details.
756 591
757 config SHRINKER_DEBUG !! 592 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
758 bool "Enable shrinker debugging suppor !! 593 of finding leaks due to the slab objects poisoning.
759 depends on DEBUG_FS !! 594
>> 595 In order to access the kmemleak file, debugfs needs to be
>> 596 mounted (usually at /sys/kernel/debug).
>> 597
>> 598 config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
>> 599 int "Maximum kmemleak early log entries"
>> 600 depends on DEBUG_KMEMLEAK
>> 601 range 200 40000
>> 602 default 16000
760 help 603 help
761 Say Y to enable the shrinker debugfs !! 604 Kmemleak must track all the memory allocations to avoid
762 visibility into the kernel memory sh !! 605 reporting false positives. Since memory may be allocated or
763 Disable it to avoid an extra memory !! 606 freed before kmemleak is initialised, an early log buffer is
>> 607 used to store these actions. If kmemleak reports "early log
>> 608 buffer exceeded", please increase this value.
764 609
765 config DEBUG_STACK_USAGE !! 610 config DEBUG_KMEMLEAK_TEST
766 bool "Stack utilization instrumentatio !! 611 tristate "Simple test for the kernel memory leak detector"
767 depends on DEBUG_KERNEL !! 612 depends on DEBUG_KMEMLEAK && m
768 help 613 help
769 Enables the display of the minimum a !! 614 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 <<
773 615
774 This option will slow down process c !! 616 If unsure, say N.
775 617
776 config SCHED_STACK_END_CHECK !! 618 config DEBUG_KMEMLEAK_DEFAULT_OFF
777 bool "Detect stack corruption on calls !! 619 bool "Default kmemleak to off"
778 depends on DEBUG_KERNEL !! 620 depends on DEBUG_KMEMLEAK
779 default n <<
780 help 621 help
781 This option checks for a stack overr !! 622 Say Y here to disable kmemleak by default. It can then be enabled
782 If the stack end location is found t !! 623 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 <<
787 624
788 config ARCH_HAS_DEBUG_VM_PGTABLE !! 625 config DEBUG_KMEMLEAK_AUTO_SCAN
789 bool !! 626 bool "Enable kmemleak auto scan thread on boot up"
>> 627 default y
>> 628 depends on DEBUG_KMEMLEAK
790 help 629 help
791 An architecture should select this w !! 630 Depending on the cpu, kmemleak scan may be cpu intensive and can
792 build and run DEBUG_VM_PGTABLE. !! 631 stall user tasks at times. This option enables/disables automatic
>> 632 kmemleak scan at boot up.
>> 633
>> 634 Say N here to disable kmemleak auto scan thread to stop automatic
>> 635 scanning. Disabling this option disables automatic reporting of
>> 636 memory leaks.
>> 637
>> 638 If unsure, say Y.
>> 639
>> 640 config DEBUG_STACK_USAGE
>> 641 bool "Stack utilization instrumentation"
>> 642 depends on DEBUG_KERNEL && !IA64
>> 643 help
>> 644 Enables the display of the minimum amount of free stack which each
>> 645 task has ever had available in the sysrq-T and sysrq-P debug output.
793 646
794 config DEBUG_VM_IRQSOFF !! 647 This option will slow down process creation somewhat.
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 648
797 config DEBUG_VM 649 config DEBUG_VM
798 bool "Debug VM" 650 bool "Debug VM"
799 depends on DEBUG_KERNEL 651 depends on DEBUG_KERNEL
800 help 652 help
801 Enable this to turn on extended chec 653 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. !! 654 that may impact performance.
803 655
804 If unsure, say N. 656 If unsure, say N.
805 657
806 config DEBUG_VM_SHOOT_LAZIES !! 658 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 659 bool "Debug VMA caching"
808 depends on DEBUG_VM 660 depends on DEBUG_VM
809 depends on MMU_LAZY_TLB_SHOOTDOWN <<
810 help 661 help
811 Enable additional IPIs that ensure l !! 662 Enable this to turn on VMA caching debug information. Doing so
812 before the mm is freed. !! 663 can cause significant overhead, so only enable it in non-production
813 !! 664 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 <<
822 665
823 If unsure, say N. 666 If unsure, say N.
824 667
825 config DEBUG_VM_RB 668 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 669 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 670 depends on DEBUG_VM
828 help 671 help
829 Enable VM red-black tree debugging i 672 Enable VM red-black tree debugging information and extra validations.
830 673
831 If unsure, say N. 674 If unsure, say N.
832 675
833 config DEBUG_VM_PGFLAGS 676 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 677 bool "Debug page-flags operations"
835 depends on DEBUG_VM 678 depends on DEBUG_VM
836 help 679 help
837 Enables extra validation on page fla 680 Enables extra validation on page flags operations.
838 681
839 If unsure, say N. 682 If unsure, say N.
840 683
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 684 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 685 bool
859 686
860 config DEBUG_VIRTUAL 687 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 688 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 689 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 690 help
864 Enable some costly sanity checks in 691 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 692 catch mistakes with virt_to_page() and friends.
866 693
867 If unsure, say N. 694 If unsure, say N.
868 695
869 config DEBUG_NOMMU_REGIONS 696 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 697 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 698 depends on DEBUG_KERNEL && !MMU
872 help 699 help
873 This option causes the global tree o 700 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 701 regions to be regularly checked for invalid topology.
875 702
876 config DEBUG_MEMORY_INIT 703 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 704 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 705 default !EXPERT
879 help 706 help
880 Enable this for additional checks du 707 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 708 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 709 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 710 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 711 on the mminit_loglevel= command-line option.
885 712
886 If unsure, say Y 713 If unsure, say Y
887 714
888 config MEMORY_NOTIFIER_ERROR_INJECT 715 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 716 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 717 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 718 help
892 This option provides the ability to 719 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 720 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 721 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 722
896 If the notifier call chain should be 723 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 724 notified, write the error code to "actions/<notifier event>/error".
898 725
899 Example: Inject memory hotplug offli 726 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 727
901 # cd /sys/kernel/debug/notifier-erro 728 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 729 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 730 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 731 bash: echo: write error: Cannot allocate memory
905 732
906 To compile this code as a module, ch 733 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 734 be called memory-notifier-error-inject.
908 735
909 If unsure, say N. 736 If unsure, say N.
910 737
911 config DEBUG_PER_CPU_MAPS 738 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 739 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 740 depends on DEBUG_KERNEL
914 depends on SMP 741 depends on SMP
915 help 742 help
916 Say Y to verify that the per_cpu map 743 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 744 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 745 and decreases performance.
919 746
920 Say N if unsure. 747 Say N if unsure.
921 748
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 749 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 750 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 751 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A <<
946 select DEBUG_KMAP_LOCAL <<
947 help 752 help
948 This option enables additional error 753 This option enables additional error checking for high memory
949 systems. Disable for production sys 754 systems. Disable for production systems.
950 755
951 config HAVE_DEBUG_STACKOVERFLOW 756 config HAVE_DEBUG_STACKOVERFLOW
952 bool 757 bool
953 758
954 config DEBUG_STACKOVERFLOW 759 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 760 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 761 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help !! 762 ---help---
958 Say Y here if you want to check for 763 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 764 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 765 option will show detailed messages if free stack space drops
961 below a certain limit. 766 below a certain limit.
962 767
963 These kinds of bugs usually occur wh 768 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 769 kernel get too deep, especially when interrupts are
965 involved. 770 involved.
966 771
967 Use this in cases where you see appa 772 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 773 corruption, especially if it appears in 'struct thread_info'
969 774
970 If in doubt, say "N". 775 If in doubt, say "N".
971 776
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" 777 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" <<
1005 source "lib/Kconfig.kmsan" <<
1006 778
1007 endmenu # "Memory Debugging" 779 endmenu # "Memory Debugging"
1008 780
1009 config DEBUG_SHIRQ !! 781 config ARCH_HAS_KCOV
1010 bool "Debug shared IRQ handlers" !! 782 bool
1011 depends on DEBUG_KERNEL <<
1012 help 783 help
1013 Enable this to generate a spurious !! 784 An architecture should select this when it can successfully
1014 interrupt handler is deregistered ( !! 785 build and run with CONFIG_KCOV. This typically requires
1015 is currently disabled). Drivers nee !! 786 disabling instrumentation for some early boot code.
1016 don't and need to be caught. <<
1017 787
1018 menu "Debug Oops, Lockups and Hangs" !! 788 config CC_HAS_SANCOV_TRACE_PC
>> 789 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1019 790
1020 config PANIC_ON_OOPS !! 791 config KCOV
1021 bool "Panic on Oops" !! 792 bool "Code coverage for fuzzing"
>> 793 depends on ARCH_HAS_KCOV
>> 794 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
>> 795 select DEBUG_FS
>> 796 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1022 help 797 help
1023 Say Y here to enable the kernel to !! 798 KCOV exposes kernel code coverage information in a form suitable
1024 has the same effect as setting oops !! 799 for coverage-guided fuzzing (randomized testing).
1025 line. <<
1026 800
1027 This feature is useful to ensure th !! 801 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1028 anything erroneous after an oops wh !! 802 different machines and across reboots. If you need stable PC values,
1029 corruption or other issues. !! 803 disable RANDOMIZE_BASE.
1030 804
1031 Say N if unsure. !! 805 For more details, see Documentation/dev-tools/kcov.rst.
1032 806
1033 config PANIC_ON_OOPS_VALUE !! 807 config KCOV_ENABLE_COMPARISONS
1034 int !! 808 bool "Enable comparison operands collection by KCOV"
1035 range 0 1 !! 809 depends on KCOV
1036 default 0 if !PANIC_ON_OOPS !! 810 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1037 default 1 if PANIC_ON_OOPS !! 811 help
>> 812 KCOV also exposes operands of every comparison in the instrumented
>> 813 code along with operand sizes and PCs of the comparison instructions.
>> 814 These operands can be used by fuzzing engines to improve the quality
>> 815 of fuzzing coverage.
1038 816
1039 config PANIC_TIMEOUT !! 817 config KCOV_INSTRUMENT_ALL
1040 int "panic timeout" !! 818 bool "Instrument all code by default"
1041 default 0 !! 819 depends on KCOV
>> 820 default y
1042 help 821 help
1043 Set the timeout value (in seconds) !! 822 If you are doing generic system call fuzzing (like e.g. syzkaller),
1044 the kernel panics. If n = 0, then w !! 823 then you will want to instrument the whole kernel and you should
1045 value n > 0 will wait n seconds bef !! 824 say y here. If you are doing more targeted fuzzing (like e.g.
1046 value n < 0 will reboot immediately !! 825 filesystem fuzzing with AFL) then you will want to enable coverage
1047 with the kernel command line option !! 826 for more specific subsets of files, and should say n here.
1048 /proc/sys/kernel/panic. !! 827
>> 828 config DEBUG_SHIRQ
>> 829 bool "Debug shared IRQ handlers"
>> 830 depends on DEBUG_KERNEL
>> 831 help
>> 832 Enable this to generate a spurious interrupt as soon as a shared
>> 833 interrupt handler is registered, and just before one is deregistered.
>> 834 Drivers ought to be able to handle interrupts coming in at those
>> 835 points; some don't and need to be caught.
>> 836
>> 837 menu "Debug Lockups and Hangs"
1049 838
1050 config LOCKUP_DETECTOR 839 config LOCKUP_DETECTOR
1051 bool 840 bool
1052 841
1053 config SOFTLOCKUP_DETECTOR 842 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 843 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 844 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 845 select LOCKUP_DETECTOR
1057 help 846 help
1058 Say Y here to enable the kernel to 847 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 848 soft lockups.
1060 849
1061 Softlockups are bugs that cause the 850 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 851 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 852 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 853 detection and the system will stay locked up.
1065 854
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 855 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 856 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 857 depends on SOFTLOCKUP_DETECTOR
1083 help 858 help
1084 Say Y here to enable the kernel to 859 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 860 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 861 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 862 sysctl), without giving other tasks a chance to run.
1088 863
1089 The panic can be used in combinatio 864 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 865 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 866 lockup has been detected. This feature is useful for
1092 high-availability systems that have 867 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 868 where a lockup must be resolved ASAP.
1094 869
1095 Say N if unsure. 870 Say N if unsure.
1096 871
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 872 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 873 int
>> 874 depends on SOFTLOCKUP_DETECTOR
>> 875 range 0 1
>> 876 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 877 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 878
>> 879 config HARDLOCKUP_DETECTOR_PERF
1098 bool 880 bool
1099 depends on SMP !! 881 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 882
1102 # 883 #
1103 # Global switch whether to build a hardlockup !! 884 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 885 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 886 #
1107 # s390: it reported many false positive !! 887 config HARDLOCKUP_CHECK_TIMESTAMP
>> 888 bool
>> 889
1108 # 890 #
1109 # sparc64: has a custom implementation !! 891 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 892 # lockup detector rather than the perf based detector.
1111 # 893 #
1112 config HARDLOCKUP_DETECTOR 894 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 895 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 896 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 897 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 898 select LOCKUP_DETECTOR
1120 !! 899 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
>> 900 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121 help 901 help
1122 Say Y here to enable the kernel to 902 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 903 hard lockups.
1124 904
1125 Hardlockups are bugs that cause the 905 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 906 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 907 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 908 and the system will stay locked up.
1129 909
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 910 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 911 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 912 depends on HARDLOCKUP_DETECTOR
1190 help 913 help
1191 Say Y here to enable the kernel to 914 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 915 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 916 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 917 using the watchdog_thresh sysctl).
1195 918
1196 Say N if unsure. 919 Say N if unsure.
1197 920
>> 921 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 922 int
>> 923 depends on HARDLOCKUP_DETECTOR
>> 924 range 0 1
>> 925 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 926 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 927
1198 config DETECT_HUNG_TASK 928 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 929 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 930 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 931 default SOFTLOCKUP_DETECTOR
1202 help 932 help
1203 Say Y here to enable the kernel to 933 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 934 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 935 uninterruptible "D" state indefinitely.
1206 936
1207 When a hung task is detected, the k 937 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 938 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 939 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 940 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 941 feature has negligible overhead.
1212 942
1213 config DEFAULT_HUNG_TASK_TIMEOUT 943 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 944 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 945 depends on DETECT_HUNG_TASK
1216 default 120 946 default 120
1217 help 947 help
1218 This option controls the default ti 948 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 949 to determine when a task has become non-responsive and should
1220 be considered hung. 950 be considered hung.
1221 951
1222 It can be adjusted at runtime via t 952 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 953 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 954 /proc/sys/kernel/hung_task_timeout_secs.
1225 955
1226 A timeout of 0 disables the check. 956 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 957 Keeping the default should be fine in most cases.
1228 958
1229 config BOOTPARAM_HUNG_TASK_PANIC 959 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 960 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 961 depends on DETECT_HUNG_TASK
1232 help 962 help
1233 Say Y here to enable the kernel to 963 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 964 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 965 in uninterruptible "D" state.
1236 966
1237 The panic can be used in combinatio 967 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 968 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 969 hung task has been detected. This feature is useful for
1240 high-availability systems that have 970 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 971 where a hung tasks must be resolved ASAP.
1242 972
1243 Say N if unsure. 973 Say N if unsure.
1244 974
>> 975 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 976 int
>> 977 depends on DETECT_HUNG_TASK
>> 978 range 0 1
>> 979 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 980 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 981
1245 config WQ_WATCHDOG 982 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 983 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 984 depends on DEBUG_KERNEL
1248 help 985 help
1249 Say Y here to enable stall detectio 986 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 987 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 988 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 989 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 990 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 991 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 992
1256 config WQ_CPU_INTENSIVE_REPORT !! 993 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 994
1269 config TEST_LOCKUP !! 995 config PANIC_ON_OOPS
1270 tristate "Test module to generate loc !! 996 bool "Panic on Oops"
1271 depends on m <<
1272 help 997 help
1273 This builds the "test_lockup" modul !! 998 Say Y here to enable the kernel to panic when it oopses. This
1274 that watchdogs and lockup detectors !! 999 has the same effect as setting oops=panic on the kernel command
>> 1000 line.
1275 1001
1276 Depending on module parameters it c !! 1002 This feature is useful to ensure that the kernel does not do
1277 lockup, "hung task", or locking arb !! 1003 anything erroneous after an oops which could result in data
1278 Also it could generate series of lo !! 1004 corruption or other issues.
1279 1005
1280 If unsure, say N. !! 1006 Say N if unsure.
1281 1007
1282 endmenu # "Debug lockups and hangs" !! 1008 config PANIC_ON_OOPS_VALUE
>> 1009 int
>> 1010 range 0 1
>> 1011 default 0 if !PANIC_ON_OOPS
>> 1012 default 1 if PANIC_ON_OOPS
1283 1013
1284 menu "Scheduler Debugging" !! 1014 config PANIC_TIMEOUT
>> 1015 int "panic timeout"
>> 1016 default 0
>> 1017 help
>> 1018 Set the timeout value (in seconds) until a reboot occurs when the
>> 1019 the kernel panics. If n = 0, then we wait forever. A timeout
>> 1020 value n > 0 will wait n seconds before rebooting, while a timeout
>> 1021 value n < 0 will reboot immediately.
1285 1022
1286 config SCHED_DEBUG 1023 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 1024 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 1025 depends on DEBUG_KERNEL && PROC_FS
1289 default y 1026 default y
1290 help 1027 help
1291 If you say Y here, the /sys/kernel/ !! 1028 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 1029 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 1030 option is minimal.
1294 1031
1295 config SCHED_INFO 1032 config SCHED_INFO
1296 bool 1033 bool
1297 default n 1034 default n
1298 1035
1299 config SCHEDSTATS 1036 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1037 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1038 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1039 select SCHED_INFO
1303 help 1040 help
1304 If you say Y here, additional code 1041 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1042 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1043 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1044 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1045 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1046 application, you can say N to avoid the very slight overhead
1310 this adds. 1047 this adds.
1311 1048
1312 endmenu !! 1049 config SCHED_STACK_END_CHECK
>> 1050 bool "Detect stack corruption on calls to schedule()"
>> 1051 depends on DEBUG_KERNEL
>> 1052 default n
>> 1053 help
>> 1054 This option checks for a stack overrun on calls to schedule().
>> 1055 If the stack end location is found to be over written always panic as
>> 1056 the content of the corrupted region can no longer be trusted.
>> 1057 This is to ensure no erroneous behaviour occurs which could result in
>> 1058 data corruption or a sporadic crash at a later stage once the region
>> 1059 is examined. The runtime overhead introduced is minimal.
1313 1060
1314 config DEBUG_TIMEKEEPING 1061 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1062 bool "Enable extra timekeeping sanity checking"
1316 help 1063 help
1317 This option will enable additional 1064 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1065 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1066 problems are suspected.
1320 1067
1321 This may include checks in the time 1068 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1069 option may have a (very small) performance impact to some
1323 workloads. 1070 workloads.
1324 1071
1325 If unsure, say N. 1072 If unsure, say N.
1326 1073
1327 config DEBUG_PREEMPT 1074 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1075 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION !! 1076 depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
>> 1077 default y
1330 help 1078 help
1331 If you say Y here then the kernel w 1079 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1080 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1081 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1082 will detect preemption count underflows.
1335 1083
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 1084 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1085
1342 config LOCK_DEBUGGING_SUPPORT 1086 config LOCK_DEBUGGING_SUPPORT
1343 bool 1087 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1088 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1089 default y
1346 1090
1347 config PROVE_LOCKING 1091 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1092 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1093 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1094 select LOCKDEP
1351 select DEBUG_SPINLOCK 1095 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1096 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1097 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1098 select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER
1355 select DEBUG_WW_MUTEX_SLOWPATH 1099 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1100 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE <<
1358 select TRACE_IRQFLAGS 1101 select TRACE_IRQFLAGS
1359 default n 1102 default n
1360 help 1103 help
1361 This feature enables the kernel to p 1104 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1105 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1106 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1107 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1108 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1109 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1110 deadlock.
1368 1111
1369 In short, this feature enables the k 1112 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1113 related deadlocks before they actually occur.
1371 1114
1372 The proof does not depend on how har 1115 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1116 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1117 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1118 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1119 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1120 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1121 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1122 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1123 makes the deadlock theoretically possible).
1381 1124
1382 If a deadlock is impossible (i.e. th 1125 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1126 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1127 kernel reports nothing.
1385 1128
1386 NOTE: this feature can also be enabl 1129 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1130 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1131 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1132 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1133 arbitrary combination of these separate locking variants.
1391 1134
1392 For more details, see Documentation/ !! 1135 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 1136
1411 config LOCK_STAT 1137 config LOCK_STAT
1412 bool "Lock usage statistics" 1138 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1139 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1140 select LOCKDEP
1415 select DEBUG_SPINLOCK 1141 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1142 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1143 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1144 select DEBUG_LOCK_ALLOC
1419 default n 1145 default n
1420 help 1146 help
1421 This feature enables tracking lock c 1147 This feature enables tracking lock contention points
1422 1148
1423 For more details, see Documentation/ !! 1149 For more details, see Documentation/locking/lockstat.txt
1424 1150
1425 This also enables lock events requir 1151 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1152 subcommand of perf.
1427 If you want to use "perf lock", you 1153 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1154 CONFIG_EVENT_TRACING.
1429 1155
1430 CONFIG_LOCK_STAT defines "contended" 1156 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1157 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1158
1433 config DEBUG_RT_MUTEXES 1159 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1160 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1161 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1162 help
1437 This allows rt mutex semantics viola 1163 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1164 deadlocks (lockups) to be detected and reported automatically.
1439 1165
1440 config DEBUG_SPINLOCK 1166 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1167 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1168 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1169 select UNINLINE_SPIN_UNLOCK
1444 help 1170 help
1445 Say Y here and build SMP to catch m 1171 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1172 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1173 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1174 deadlocks are also debuggable.
1449 1175
1450 config DEBUG_MUTEXES 1176 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1177 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1178 depends on DEBUG_KERNEL
1453 help 1179 help
1454 This feature allows mutex semantics 1180 This feature allows mutex semantics violations to be detected and
1455 reported. 1181 reported.
1456 1182
1457 config DEBUG_WW_MUTEX_SLOWPATH 1183 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1184 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1185 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1186 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1187 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1188 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1189 help
1465 This feature enables slowpath testin 1190 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1191 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1192 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1193 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1194 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1195 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1196 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1197 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1198 you are a distro, do not.
1474 1199
1475 config DEBUG_RWSEMS 1200 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1201 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1202 depends on DEBUG_KERNEL && RWSEM_SPIN_ON_OWNER
1478 help 1203 help
1479 This debugging feature allows misma !! 1204 This debugging feature allows mismatched rw semaphore locks and unlocks
1480 and unlocks to be detected and repo !! 1205 to be detected and reported.
1481 1206
1482 config DEBUG_LOCK_ALLOC 1207 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1208 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1209 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1210 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1211 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1212 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1213 select LOCKDEP
1489 help 1214 help
1490 This feature will check whether any 1215 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1216 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1217 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1218 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1219 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1220 held during task exit.
1496 1221
1497 config LOCKDEP 1222 config LOCKDEP
1498 bool 1223 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1224 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1225 select STACKTRACE
>> 1226 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1501 select KALLSYMS 1227 select KALLSYMS
1502 select KALLSYMS_ALL 1228 select KALLSYMS_ALL
1503 1229
1504 config LOCKDEP_SMALL 1230 config LOCKDEP_SMALL
1505 bool 1231 bool
1506 1232
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 1233 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1234 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1235 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS <<
1551 help 1236 help
1552 If you say Y here, the lock depende 1237 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1238 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1239 of more runtime overhead.
1555 1240
1556 config DEBUG_ATOMIC_SLEEP 1241 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1242 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1243 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1244 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1245 depends on !ARCH_NO_PREEMPT
1561 help 1246 help
1562 If you say Y here, various routines 1247 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1248 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1249 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1250 sections, inside an interrupt, etc...
1566 1251
1567 config DEBUG_LOCKING_API_SELFTESTS 1252 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1253 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1254 depends on DEBUG_KERNEL
1570 help 1255 help
1571 Say Y here if you want the kernel t 1256 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1257 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1258 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1259 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1260 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1261 mutexes and rwsems.
1577 1262
1578 config LOCK_TORTURE_TEST 1263 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1264 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1265 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1266 select TORTURE_TEST
1582 help 1267 help
1583 This option provides a kernel modul 1268 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1269 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1270 after the fact on the running kernel to be tested, if desired.
1586 1271
1587 Say Y here if you want kernel locki 1272 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1273 to be built into the kernel.
1589 Say M if you want these torture tes 1274 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1275 Say N if you are unsure.
1591 1276
1592 config WW_MUTEX_SELFTEST 1277 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1278 tristate "Wait/wound mutex selftests"
1594 help 1279 help
1595 This option provides a kernel modul 1280 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1281 on the struct ww_mutex locking API.
1597 1282
1598 It is recommended to enable DEBUG_W 1283 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1284 with this test harness.
1600 1285
1601 Say M if you want these self tests 1286 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1287 Say N if you are unsure.
1603 1288
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 1289 endmenu # lock debugging
1635 1290
1636 config TRACE_IRQFLAGS 1291 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT <<
1638 bool 1292 bool
1639 help 1293 help
1640 Enables hooks to interrupt enabling 1294 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1295 either tracing or lock debugging.
1642 1296
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 1297 config STACKTRACE
1667 bool "Stack backtrace support" 1298 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1299 depends on STACKTRACE_SUPPORT
1669 help 1300 help
1670 This option causes the kernel to cr 1301 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1302 every process, showing its current stack trace.
1672 It is also used by various kernel d 1303 It is also used by various kernel debugging features that require
1673 stack trace generation. 1304 stack trace generation.
1674 1305
1675 config WARN_ALL_UNSEEDED_RANDOM 1306 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1307 bool "Warn for all uses of unseeded randomness"
1677 default n 1308 default n
1678 help 1309 help
1679 Some parts of the kernel contain bu 1310 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1311 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1312 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1313 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1314 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1315 are going wrong, so that they might contact developers about fixing
1685 it. 1316 it.
1686 1317
1687 Unfortunately, on some models of so 1318 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1319 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1320 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1321 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1322 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1323 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1324 However, since users cannot do anything actionable to
1694 address this, by default this optio !! 1325 address this, by default the kernel will issue only a single
>> 1326 warning for the first use of unseeded randomness.
1695 1327
1696 Say Y here if you want to receive w 1328 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1329 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1330 those developers interested in improving the security of
1699 Linux kernels running on their arch 1331 Linux kernels running on their architecture (or
1700 subarchitecture). 1332 subarchitecture).
1701 1333
1702 config DEBUG_KOBJECT 1334 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1335 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1336 depends on DEBUG_KERNEL
1705 help 1337 help
1706 If you say Y here, some extra kobje 1338 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1339 to the syslog.
1708 1340
1709 config DEBUG_KOBJECT_RELEASE 1341 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1342 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1343 depends on DEBUG_OBJECTS_TIMERS
1712 help 1344 help
1713 kobjects are reference counted obje 1345 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1346 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1347 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1348 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1349 example of this would be a struct device which has just been
1718 unregistered. 1350 unregistered.
1719 1351
1720 However, some buggy drivers assume 1352 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1353 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1354 goes completely against the principles of a refcounted object.
1723 1355
1724 If you say Y here, the kernel will 1356 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1357 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1358 kind of kobject release bug.
1727 1359
1728 config HAVE_DEBUG_BUGVERBOSE 1360 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1361 bool
1730 1362
1731 menu "Debug kernel data structures" !! 1363 config DEBUG_BUGVERBOSE
>> 1364 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
>> 1365 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
>> 1366 default y
>> 1367 help
>> 1368 Say Y here to make BUG() panics output the file name and line number
>> 1369 of the BUG call as well as the EIP and oops trace. This aids
>> 1370 debugging but costs about 70-100K of memory.
1732 1371
1733 config DEBUG_LIST 1372 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1373 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1374 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1375 help
1738 Enable this to turn on extended che !! 1376 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1377 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 1378
1745 If unsure, say N. 1379 If unsure, say N.
1746 1380
1747 config DEBUG_PLIST 1381 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1382 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1383 depends on DEBUG_KERNEL
1750 help 1384 help
1751 Enable this to turn on extended che 1385 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1386 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1387 list multiple times during each manipulation.
1754 1388
1755 If unsure, say N. 1389 If unsure, say N.
1756 1390
1757 config DEBUG_SG 1391 config DEBUG_SG
1758 bool "Debug SG table operations" 1392 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1393 depends on DEBUG_KERNEL
1760 help 1394 help
1761 Enable this to turn on checks on sc 1395 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1396 help find problems with drivers that do not properly initialize
1763 their sg tables. 1397 their sg tables.
1764 1398
1765 If unsure, say N. 1399 If unsure, say N.
1766 1400
1767 config DEBUG_NOTIFIERS 1401 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1402 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1403 depends on DEBUG_KERNEL
1770 help 1404 help
1771 Enable this to turn on sanity check 1405 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1406 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1407 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1408 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1409 performance, say N.
1776 1410
1777 config DEBUG_CLOSURES !! 1411 config DEBUG_CREDENTIALS
1778 bool "Debug closures (bcache async wi !! 1412 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 1413 depends on DEBUG_KERNEL
1789 help 1414 help
1790 Enable maple tree debugging informa !! 1415 Enable this to turn on some debug checking for credential
>> 1416 management. The additional code keeps track of the number of
>> 1417 pointers from task_structs to any given cred struct, and checks to
>> 1418 see that this number never exceeds the usage count of the cred
>> 1419 struct.
1791 1420
1792 If unsure, say N. !! 1421 Furthermore, if SELinux is enabled, this also checks that the
>> 1422 security pointer in the cred struct is never seen to be invalid.
1793 1423
1794 endmenu !! 1424 If unsure, say N.
1795 1425
1796 source "kernel/rcu/Kconfig.debug" 1426 source "kernel/rcu/Kconfig.debug"
1797 1427
1798 config DEBUG_WQ_FORCE_RR_CPU 1428 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1429 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1430 depends on DEBUG_KERNEL
1801 default n 1431 default n
1802 help 1432 help
1803 Workqueue used to implicitly guaran 1433 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1434 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1435 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1436 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1437 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1438 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1439 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1440 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1441 be impacted.
1812 1442
>> 1443 config DEBUG_BLOCK_EXT_DEVT
>> 1444 bool "Force extended block device numbers and spread them"
>> 1445 depends on DEBUG_KERNEL
>> 1446 depends on BLOCK
>> 1447 default n
>> 1448 help
>> 1449 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1450 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1451 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1452 is broken.
>> 1453
>> 1454 Conventionally, block device numbers are allocated from
>> 1455 predetermined contiguous area. However, extended block area
>> 1456 may introduce non-contiguous block device numbers. This
>> 1457 option forces most block device numbers to be allocated from
>> 1458 the extended space and spreads them to discover kernel or
>> 1459 userland code paths which assume predetermined contiguous
>> 1460 device number allocation.
>> 1461
>> 1462 Note that turning on this debug option shuffles all the
>> 1463 device numbers for all IDE and SCSI devices including libata
>> 1464 ones, so root partition specified using device number
>> 1465 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1466 Textual device names (root=/dev/sdXn) will continue to work.
>> 1467
>> 1468 Say N if you are unsure.
>> 1469
1813 config CPU_HOTPLUG_STATE_CONTROL 1470 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1471 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1472 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1473 depends on HOTPLUG_CPU
1817 default n 1474 default n
1818 help 1475 help
1819 Allows to write steps between "offl 1476 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1477 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1478 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1479 restarted at arbitrary points yet.
1823 1480
1824 Say N if your are unsure. 1481 Say N if your are unsure.
1825 1482
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 1483 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1484 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1485 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1486 select DEBUG_FS
1936 help 1487 help
1937 This option provides the ability to 1488 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1489 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1490 handling of notifier call chain failures.
1940 1491
1941 Say N if unsure. 1492 Say N if unsure.
1942 1493
1943 config PM_NOTIFIER_ERROR_INJECT 1494 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1495 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1496 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1497 default m if PM_DEBUG
1947 help 1498 help
1948 This option provides the ability to 1499 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1500 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1501 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1502
1952 If the notifier call chain should b 1503 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1504 notified, write the error code to "actions/<notifier event>/error".
1954 1505
1955 Example: Inject PM suspend error (- 1506 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1507
1957 # cd /sys/kernel/debug/notifier-err 1508 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1509 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1510 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1511 bash: echo: write error: Cannot allocate memory
1961 1512
1962 To compile this code as a module, c 1513 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1514 be called pm-notifier-error-inject.
1964 1515
1965 If unsure, say N. 1516 If unsure, say N.
1966 1517
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1518 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1519 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1520 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1521 help
1971 This option provides the ability to 1522 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1523 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1524 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1525 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1526
1976 If the notifier call chain should b 1527 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1528 notified, write the error code to "actions/<notifier event>/error".
1978 1529
1979 To compile this code as a module, c 1530 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1531 be called of-reconfig-notifier-error-inject.
1981 1532
1982 If unsure, say N. 1533 If unsure, say N.
1983 1534
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1535 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1536 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1537 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1538 help
1988 This option provides the ability to 1539 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1540 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1541 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1542
1992 If the notifier call chain should b 1543 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1544 notified, write the error code to "actions/<notifier event>/error".
1994 1545
1995 Example: Inject netdevice mtu chang 1546 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1547
1997 # cd /sys/kernel/debug/notifier-err 1548 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1549 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1550 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1551 RTNETLINK answers: Invalid argument
2001 1552
2002 To compile this code as a module, c 1553 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1554 be called netdev-notifier-error-inject.
2004 1555
2005 If unsure, say N. 1556 If unsure, say N.
2006 1557
2007 config FUNCTION_ERROR_INJECTION 1558 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" !! 1559 def_bool y
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1560 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 1561
2017 config FAULT_INJECTION 1562 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1563 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1564 depends on DEBUG_KERNEL
2020 help 1565 help
2021 Provide fault-injection framework. 1566 Provide fault-injection framework.
2022 For more details, see Documentation 1567 For more details, see Documentation/fault-injection/.
2023 1568
2024 config FAILSLAB 1569 config FAILSLAB
2025 bool "Fault-injection capability for 1570 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1571 depends on FAULT_INJECTION
>> 1572 depends on SLAB || SLUB
2027 help 1573 help
2028 Provide fault-injection capability 1574 Provide fault-injection capability for kmalloc.
2029 1575
2030 config FAIL_PAGE_ALLOC 1576 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for !! 1577 bool "Fault-injection capabilitiy for alloc_pages()"
2032 depends on FAULT_INJECTION 1578 depends on FAULT_INJECTION
2033 help 1579 help
2034 Provide fault-injection capability 1580 Provide fault-injection capability for alloc_pages().
2035 1581
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 1582 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1583 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1584 depends on FAULT_INJECTION && BLOCK
2046 help 1585 help
2047 Provide fault-injection capability 1586 Provide fault-injection capability for disk IO.
2048 1587
2049 config FAIL_IO_TIMEOUT 1588 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1589 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1590 depends on FAULT_INJECTION && BLOCK
2052 help 1591 help
2053 Provide fault-injection capability 1592 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1593 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1594 thus exercising the error handling.
2056 1595
2057 Only works with drivers that use th 1596 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1597 for others it wont do anything.
2059 1598
2060 config FAIL_FUTEX 1599 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1600 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1601 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1602 depends on FAULT_INJECTION && FUTEX
2064 help 1603 help
2065 Provide fault-injection capability 1604 Provide fault-injection capability for futexes.
2066 1605
2067 config FAULT_INJECTION_DEBUG_FS 1606 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1607 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1608 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1609 help
2071 Enable configuration of fault-injec 1610 Enable configuration of fault-injection capabilities via debugfs.
2072 1611
2073 config FAIL_FUNCTION 1612 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1613 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1614 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1615 help
2077 Provide function-based fault-inject 1616 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1617 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1618 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1619 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1620 error handling in various subsystems.
2082 1621
2083 config FAIL_MMC_REQUEST 1622 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1623 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1624 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1625 help
2087 Provide fault-injection capability 1626 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1627 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1628 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1629 and to test how the mmc host driver handles retries from
2091 the block device. 1630 the block device.
2092 1631
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 1632 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1633 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1634 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1635 depends on !X86_64
2115 select STACKTRACE 1636 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P !! 1637 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
2117 help 1638 help
2118 Provide stacktrace filter for fault 1639 Provide stacktrace filter for fault-injection capabilities
2119 1640
2120 config ARCH_HAS_KCOV !! 1641 config LATENCYTOP
2121 bool !! 1642 bool "Latency measuring infrastructure"
>> 1643 depends on DEBUG_KERNEL
>> 1644 depends on STACKTRACE_SUPPORT
>> 1645 depends on PROC_FS
>> 1646 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
>> 1647 select KALLSYMS
>> 1648 select KALLSYMS_ALL
>> 1649 select STACKTRACE
>> 1650 select SCHEDSTATS
>> 1651 select SCHED_DEBUG
2122 help 1652 help
2123 An architecture should select this !! 1653 Enable this option if you want to use the LatencyTOP tool
2124 build and run with CONFIG_KCOV. Thi !! 1654 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 1655
>> 1656 source "kernel/trace/Kconfig"
2130 1657
2131 config KCOV !! 1658 config PROVIDE_OHCI1394_DMA_INIT
2132 bool "Code coverage for fuzzing" !! 1659 bool "Remote debugging over FireWire early on boot"
2133 depends on ARCH_HAS_KCOV !! 1660 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 1661 help
2141 KCOV exposes kernel code coverage i !! 1662 If you want to debug problems which hang or crash the kernel early
2142 for coverage-guided fuzzing (random !! 1663 on boot and the crashing machine has a FireWire port, you can use
>> 1664 this feature to remotely access the memory of the crashed machine
>> 1665 over FireWire. This employs remote DMA as part of the OHCI1394
>> 1666 specification which is now the standard for FireWire controllers.
2143 1667
2144 For more details, see Documentation !! 1668 With remote DMA, you can monitor the printk buffer remotely using
>> 1669 firescope and access all memory below 4GB using fireproxy from gdb.
>> 1670 Even controlling a kernel debugger is possible using remote DMA.
2145 1671
2146 config KCOV_ENABLE_COMPARISONS !! 1672 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 1673
2156 config KCOV_INSTRUMENT_ALL !! 1674 If ohci1394_dma=early is used as boot parameter, it will initialize
2157 bool "Instrument all code by default" !! 1675 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 1676
2167 config KCOV_IRQ_AREA_SIZE !! 1677 As all changes to the FireWire bus such as enabling and disabling
2168 hex "Size of interrupt coverage colle !! 1678 devices cause a bus reset and thereby disable remote DMA for all
2169 depends on KCOV !! 1679 devices, be sure to have the cable plugged and FireWire enabled on
2170 default 0x40000 !! 1680 the debugging host before booting the debug target for debugging.
2171 help !! 1681
2172 KCOV uses preallocated per-cpu area !! 1682 This code (~1k) is freed after boot. By then, the firewire stack
2173 soft interrupts. This specifies the !! 1683 in charge of the OHCI-1394 controllers should be used instead.
2174 number of unsigned long words. !! 1684
>> 1685 See Documentation/debugging-via-ohci1394.txt for more information.
2175 1686
2176 menuconfig RUNTIME_TESTING_MENU 1687 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 1688 bool "Runtime Testing"
2178 default y !! 1689 def_bool y
2179 1690
2180 if RUNTIME_TESTING_MENU 1691 if RUNTIME_TESTING_MENU
2181 1692
2182 config TEST_DHRY <<
2183 tristate "Dhrystone benchmark test" <<
2184 help <<
2185 Enable this to include the Dhryston <<
2186 calculates the number of Dhrystones <<
2187 DMIPS (Dhrystone MIPS) obtained whe <<
2188 by 1757 (the number of Dhrystones p <<
2189 11/780, nominally a 1 MIPS machine) <<
2190 <<
2191 To run the benchmark, it needs to b <<
2192 the kernel command line (when built <<
2193 built-in or modular). <<
2194 <<
2195 Run once during kernel boot: <<
2196 <<
2197 test_dhry.run <<
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 <<
2207 Trigger manual run from userspace: <<
2208 <<
2209 echo y > /sys/module/test_dhry/ <<
2210 <<
2211 If the number of iterations is <= 0 <<
2212 number of iterations (test runs for <<
2213 This process takes ca. 4s. <<
2214 <<
2215 If unsure, say N. <<
2216 <<
2217 config LKDTM 1693 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 1694 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 1695 depends on DEBUG_FS
2220 help 1696 help
2221 This module enables testing of the di 1697 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 1698 inducing system failures at predefined crash points.
2223 If you don't need it: say N 1699 If you don't need it: say N
2224 Choose M here to compile this code as 1700 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 1701 called lkdtm.
2226 1702
2227 Documentation on how to use the modul 1703 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke !! 1704 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 1705
2242 config TEST_LIST_SORT 1706 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 1707 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 1708 depends on DEBUG_KERNEL || m
2256 help 1709 help
2257 Enable this to turn on min heap fun !! 1710 Enable this to turn on 'list_sort()' function test. This test is
2258 executed only once during system bo 1711 executed only once during system boot (so affects only boot time),
2259 or at module load time. 1712 or at module load time.
2260 1713
2261 If unsure, say N. 1714 If unsure, say N.
2262 1715
2263 config TEST_SORT 1716 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 1717 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 1718 depends on DEBUG_KERNEL || m
2276 help 1719 help
2277 Enable this to turn on 'do_div()' f !! 1720 This option enables the self-test function of 'sort()' at boot,
2278 executed only once during system bo <<
2279 or at module load time. 1721 or at module load time.
2280 1722
2281 If unsure, say N. 1723 If unsure, say N.
2282 1724
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 1725 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 1726 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 1727 depends on DEBUG_KERNEL
2298 depends on KPROBES 1728 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 1729 help
2303 This option provides for testing ba 1730 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 1731 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 1732 verified for functionality.
2306 1733
2307 Say N if you are unsure. 1734 Say N if you are unsure.
2308 1735
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 1736 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 1737 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 1738 depends on DEBUG_KERNEL
2324 help 1739 help
2325 This option provides a kernel modul 1740 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 1741 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 1742 for distributions or general kernels, but only for kernel
2328 developers working on architecture 1743 developers working on architecture code.
2329 1744
2330 Note that if you want to also test 1745 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 1746 have to enable STACKTRACE as well.
2332 1747
2333 Say N if you are unsure. 1748 Say N if you are unsure.
2334 1749
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 1750 config RBTREE_TEST
2346 tristate "Red-Black tree test" 1751 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 1752 depends on DEBUG_KERNEL
2348 help 1753 help
2349 A benchmark measuring the performan 1754 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 1755 Also includes rbtree invariant checks.
2351 1756
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 1757 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 1758 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 1759 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 1760 select INTERVAL_TREE
2368 help 1761 help
2369 A benchmark measuring the performan 1762 A benchmark measuring the performance of the interval tree library
2370 1763
2371 config PERCPU_TEST 1764 config PERCPU_TEST
2372 tristate "Per cpu operations test" 1765 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 1766 depends on m && DEBUG_KERNEL
2374 help 1767 help
2375 Enable this option to build test mo 1768 Enable this option to build test module which validates per-cpu
2376 operations. 1769 operations.
2377 1770
2378 If unsure, say N. 1771 If unsure, say N.
2379 1772
2380 config ATOMIC64_SELFTEST 1773 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 1774 tristate "Perform an atomic64_t self-test"
2382 help 1775 help
2383 Enable this option to test the atom 1776 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 1777 at module load time.
2385 1778
2386 If unsure, say N. 1779 If unsure, say N.
2387 1780
2388 config ASYNC_RAID6_TEST 1781 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 1782 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 1783 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 1784 select ASYNC_MEMCPY
2392 help !! 1785 ---help---
2393 This is a one-shot self test that p 1786 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 1787 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 1788 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 1789 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 1790 engine if one is available.
2398 1791
2399 If unsure, say N. 1792 If unsure, say N.
2400 1793
2401 config TEST_HEXDUMP 1794 config TEST_HEXDUMP
2402 tristate "Test functions located in t 1795 tristate "Test functions located in the hexdump module at runtime"
2403 1796
2404 config STRING_KUNIT_TEST !! 1797 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 1798 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT !! 1799
2407 default KUNIT_ALL_TESTS !! 1800 config TEST_STRSCPY
2408 !! 1801 tristate "Test strscpy*() family of functions at runtime"
2409 config STRING_HELPERS_KUNIT_TEST <<
2410 tristate "KUnit test string helpers a <<
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 1802
2414 config TEST_KSTRTOX 1803 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 1804 tristate "Test kstrto*() family of functions at runtime"
2416 1805
2417 config TEST_PRINTF 1806 config TEST_PRINTF
2418 tristate "Test printf() family of fun 1807 tristate "Test printf() family of functions at runtime"
2419 1808
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 1809 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 1810 tristate "Test bitmap_*() family of functions at runtime"
2425 help 1811 help
2426 Enable this option to test the bitm 1812 Enable this option to test the bitmap functions at boot.
2427 1813
2428 If unsure, say N. 1814 If unsure, say N.
2429 1815
>> 1816 config TEST_BITFIELD
>> 1817 tristate "Test bitfield functions at runtime"
>> 1818 help
>> 1819 Enable this option to test the bitfield functions at boot.
>> 1820
>> 1821 If unsure, say N.
>> 1822
2430 config TEST_UUID 1823 config TEST_UUID
2431 tristate "Test functions located in t 1824 tristate "Test functions located in the uuid module at runtime"
2432 1825
2433 config TEST_XARRAY 1826 config TEST_XARRAY
2434 tristate "Test the XArray code at run 1827 tristate "Test the XArray code at runtime"
2435 1828
2436 config TEST_MAPLE_TREE !! 1829 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 1830 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 1831
2445 config TEST_RHASHTABLE 1832 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 1833 tristate "Perform selftest on resizable hash table"
2447 help 1834 help
2448 Enable this option to test the rhas 1835 Enable this option to test the rhashtable functions at boot.
2449 1836
2450 If unsure, say N. 1837 If unsure, say N.
2451 1838
>> 1839 config TEST_HASH
>> 1840 tristate "Perform selftest on hash functions"
>> 1841 help
>> 1842 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 1843 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 1844 hash functions on boot (or module load).
>> 1845
>> 1846 This is intended to help people writing architecture-specific
>> 1847 optimized versions. If unsure, say N.
>> 1848
2452 config TEST_IDA 1849 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 1850 tristate "Perform selftest on IDA functions"
2454 1851
2455 config TEST_PARMAN 1852 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 1853 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 1854 depends on PARMAN
2458 help 1855 help
2459 Enable this option to test priority 1856 Enable this option to test priority array manager on boot
2460 (or module load). 1857 (or module load).
2461 1858
2462 If unsure, say N. 1859 If unsure, say N.
2463 1860
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 1861 config TEST_LKM
2473 tristate "Test module loading with 'h 1862 tristate "Test module loading with 'hello world' module"
2474 depends on m 1863 depends on m
2475 help 1864 help
2476 This builds the "test_module" modul 1865 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 1866 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 1867 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 1868 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 1869 and will not normally be loaded by the system unless explicitly
2481 requested by name. 1870 requested by name.
2482 1871
2483 If unsure, say N. 1872 If unsure, say N.
2484 1873
2485 config TEST_BITOPS <<
2486 tristate "Test module for compilation <<
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 1874 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 1875 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 1876 default n
2500 depends on MMU 1877 depends on MMU
2501 depends on m 1878 depends on m
2502 help 1879 help
2503 This builds the "test_vmalloc" modu 1880 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 1881 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 1882 subsystem can be evaluated from performance and stability point
2506 of view. 1883 of view.
2507 1884
2508 If unsure, say N. 1885 If unsure, say N.
2509 1886
>> 1887 config TEST_USER_COPY
>> 1888 tristate "Test user/kernel boundary protections"
>> 1889 depends on m
>> 1890 help
>> 1891 This builds the "test_user_copy" module that runs sanity checks
>> 1892 on the copy_to/from_user infrastructure, making sure basic
>> 1893 user/kernel boundary testing is working. If it fails to load,
>> 1894 a regression has been detected in the user/kernel memory boundary
>> 1895 protections.
>> 1896
>> 1897 If unsure, say N.
>> 1898
2510 config TEST_BPF 1899 config TEST_BPF
2511 tristate "Test BPF filter functionali 1900 tristate "Test BPF filter functionality"
2512 depends on m && NET 1901 depends on m && NET
2513 help 1902 help
2514 This builds the "test_bpf" module t 1903 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 1904 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 1905 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 1906 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 1907 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 1908 verifier used by user space verifier testsuite.
2520 1909
2521 If unsure, say N. 1910 If unsure, say N.
2522 1911
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 1912 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 1913 tristate "Test find_bit functions"
2534 help 1914 help
2535 This builds the "test_find_bit" mod 1915 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 1916 functions performance.
2537 1917
2538 If unsure, say N. 1918 If unsure, say N.
2539 1919
2540 config TEST_FIRMWARE 1920 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 1921 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 1922 depends on FW_LOADER
2543 help 1923 help
2544 This builds the "test_firmware" mod 1924 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 1925 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 1926 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 1927 actual firmware-using device. The contents can be rechecked by
2548 userspace. 1928 userspace.
2549 1929
2550 If unsure, say N. 1930 If unsure, say N.
2551 1931
2552 config TEST_SYSCTL 1932 config TEST_SYSCTL
2553 tristate "sysctl test driver" 1933 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 1934 depends on PROC_SYSCTL
2555 help 1935 help
2556 This builds the "test_sysctl" modul 1936 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 1937 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 1938 production knobs which might alter system functionality.
2559 1939
2560 If unsure, say N. 1940 If unsure, say N.
2561 1941
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 1942 config TEST_UDELAY
2817 tristate "udelay test driver" 1943 tristate "udelay test driver"
2818 help 1944 help
2819 This builds the "udelay_test" modul 1945 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 1946 that udelay() is working properly.
2821 1947
2822 If unsure, say N. 1948 If unsure, say N.
2823 1949
2824 config TEST_STATIC_KEYS 1950 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 1951 tristate "Test static keys"
2826 depends on m 1952 depends on m
2827 help 1953 help
2828 Test the static key interfaces. 1954 Test the static key interfaces.
2829 1955
2830 If unsure, say N. 1956 If unsure, say N.
2831 1957
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 1958 config TEST_KMOD
2843 tristate "kmod stress tester" 1959 tristate "kmod stress tester"
2844 depends on m 1960 depends on m
2845 depends on NETDEVICES && NET_CORE && 1961 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 1962 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 1963 select TEST_LKM
2849 select XFS_FS 1964 select XFS_FS
2850 select TUN 1965 select TUN
2851 select BTRFS_FS 1966 select BTRFS_FS
2852 help 1967 help
2853 Test the kernel's module loading me 1968 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 1969 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 1970 This test provides a series of tests against kmod.
2856 1971
2857 Although technically you can either 1972 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 1973 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 1974 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 1975 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 1976 module load requests, ultimately this could be fatal.
2862 1977
2863 To run tests run: 1978 To run tests run:
2864 1979
2865 tools/testing/selftests/kmod/kmod.s 1980 tools/testing/selftests/kmod/kmod.sh --help
2866 1981
2867 If unsure, say N. 1982 If unsure, say N.
2868 1983
2869 config TEST_DEBUG_VIRTUAL 1984 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 1985 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 1986 depends on DEBUG_VIRTUAL
2872 help 1987 help
2873 Test the kernel's ability to detect 1988 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 1989 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 1990 kernel's virtual address map.
2876 1991
2877 If unsure, say N. 1992 If unsure, say N.
2878 1993
2879 config TEST_MEMCAT_P 1994 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 1995 tristate "Test memcat_p() helper function"
2881 help 1996 help
2882 Test the memcat_p() helper for corr 1997 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 1998 pointer arrays together.
2884 1999
2885 If unsure, say N. 2000 If unsure, say N.
2886 2001
2887 config TEST_OBJAGG !! 2002 config TEST_LIVEPATCH
2888 tristate "Perform selftest on object !! 2003 tristate "Test livepatching"
2889 default n 2004 default n
2890 depends on OBJAGG !! 2005 depends on DYNAMIC_DEBUG
2891 help !! 2006 depends on LIVEPATCH
2892 Enable this option to test object a !! 2007 depends on m
2893 (or module load). <<
2894 <<
2895 config TEST_MEMINIT <<
2896 tristate "Test heap/page initializati <<
2897 help 2008 help
2898 Test if the kernel is zero-initiali !! 2009 Test kernel livepatching features for correctness. The tests will
2899 This can be useful to test init_on_ !! 2010 load test modules that will be livepatched in various scenarios.
2900 2011
2901 If unsure, say N. !! 2012 To run all the livepatching tests:
2902 2013
2903 config TEST_HMM !! 2014 make -C tools/testing/selftests TARGETS=livepatch run_tests
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 2015
2914 If unsure, say N. !! 2016 Alternatively, individual tests may be invoked:
2915 2017
2916 config TEST_FREE_PAGES !! 2018 tools/testing/selftests/livepatch/test-callbacks.sh
2917 tristate "Test freeing pages" !! 2019 tools/testing/selftests/livepatch/test-livepatch.sh
2918 help !! 2020 tools/testing/selftests/livepatch/test-shadow-vars.sh
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 2021
2934 If unsure, say N. 2022 If unsure, say N.
2935 2023
2936 config TEST_CLOCKSOURCE_WATCHDOG !! 2024 config TEST_OBJAGG
2937 tristate "Test clocksource watchdog i !! 2025 tristate "Perform selftest on object aggreration manager"
2938 depends on CLOCKSOURCE_WATCHDOG !! 2026 default n
>> 2027 depends on OBJAGG
2939 help 2028 help
2940 Enable this option to create a kern !! 2029 Enable this option to test object aggregation manager on boot
2941 a test of the clocksource watchdog. !! 2030 (or module load).
2942 via modprobe or insmod in which cas <<
2943 loaded, or it may be built in, in w <<
2944 shortly after boot. <<
2945 2031
2946 If unsure, say N. <<
2947 2032
2948 config TEST_OBJPOOL !! 2033 config TEST_STACKINIT
2949 tristate "Test module for correctness !! 2034 tristate "Test level of stack variable initialization"
2950 default n <<
2951 depends on m && DEBUG_KERNEL <<
2952 help 2035 help
2953 This builds the "test_objpool" modu !! 2036 Test if the kernel is zero-initializing stack variables and
2954 correctness verification and concur !! 2037 padding. Coverage is controlled by compiler flags,
2955 allocation and reclamation. !! 2038 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
>> 2039 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2956 2040
2957 If unsure, say N. 2041 If unsure, say N.
2958 2042
2959 endif # RUNTIME_TESTING_MENU 2043 endif # RUNTIME_TESTING_MENU
2960 2044
2961 config ARCH_USE_MEMTEST <<
2962 bool <<
2963 help <<
2964 An architecture should select this <<
2965 during boot process. <<
2966 <<
2967 config MEMTEST 2045 config MEMTEST
2968 bool "Memtest" 2046 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST !! 2047 ---help---
2970 help <<
2971 This option adds a kernel parameter 2048 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. !! 2049 to be set.
2973 memtest=0, mean disabled; -- 2050 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2051 memtest=1, mean do 1 test pattern;
2975 ... 2052 ...
2976 memtest=17, mean do 17 test p 2053 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2054 If you are unsure how to answer this question, answer N.
2978 2055
2979 !! 2056 config BUG_ON_DATA_CORRUPTION
2980 !! 2057 bool "Trigger a BUG when data corruption is detected"
2981 config HYPERV_TESTING !! 2058 select DEBUG_LIST
2982 bool "Microsoft Hyper-V driver testin !! 2059 help
2983 default n !! 2060 Select this option if the kernel should BUG when it encounters
2984 depends on HYPERV && DEBUG_FS !! 2061 data corruption in kernel memory structures when they get checked
2985 help !! 2062 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 2063
3005 If unsure, say N. 2064 If unsure, say N.
3006 2065
3007 config RUST_OVERFLOW_CHECKS !! 2066 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 2067
3018 Note that this will apply to all Ru !! 2068 source "lib/Kconfig.kgdb"
3019 2069
3020 If unsure, say Y. !! 2070 source "lib/Kconfig.ubsan"
3021 2071
3022 config RUST_BUILD_ASSERT_ALLOW !! 2072 config ARCH_HAS_DEVMEM_IS_ALLOWED
3023 bool "Allow unoptimized build-time as !! 2073 bool
3024 depends on RUST <<
3025 help <<
3026 Controls how are `build_error!` and <<
3027 2074
3028 If calls to them exist in the binar !! 2075 config STRICT_DEVMEM
3029 or that the optimizer failed to ver !! 2076 bool "Filter access to /dev/mem"
>> 2077 depends on MMU && DEVMEM
>> 2078 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
>> 2079 default y if PPC || X86 || ARM64
>> 2080 ---help---
>> 2081 If this option is disabled, you allow userspace (root) access to all
>> 2082 of memory, including kernel and userspace memory. Accidental
>> 2083 access to this is obviously disastrous, but specific access can
>> 2084 be used by people debugging the kernel. Note that with PAT support
>> 2085 enabled, even in this case there are restrictions on /dev/mem
>> 2086 use due to the cache aliasing requirements.
3030 2087
3031 This should not happen, thus by def !! 2088 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
3032 as an escape hatch, you can choose !! 2089 file only allows userspace access to PCI space and the BIOS code and
3033 and let the check be carried at run !! 2090 data regions. This is sufficient for dosemu and X and all common
3034 the check fails). !! 2091 users of /dev/mem.
3035 2092
3036 If unsure, say N. !! 2093 If in doubt, say Y.
3037 2094
3038 config RUST_KERNEL_DOCTESTS !! 2095 config IO_STRICT_DEVMEM
3039 bool "Doctests for the `kernel` crate !! 2096 bool "Filter I/O access to /dev/mem"
3040 depends on RUST && KUNIT=y !! 2097 depends on STRICT_DEVMEM
3041 default KUNIT_ALL_TESTS !! 2098 ---help---
3042 help !! 2099 If this option is disabled, you allow userspace (root) access to all
3043 This builds the documentation tests !! 2100 io-memory regardless of whether a driver is actively using that
3044 as KUnit tests. !! 2101 range. Accidental access to this is obviously disastrous, but
>> 2102 specific access can be used by people debugging kernel drivers.
3045 2103
3046 For more information on KUnit and u !! 2104 If this option is switched on, the /dev/mem file only allows
3047 please refer to the KUnit documenta !! 2105 userspace access to *idle* io-memory ranges (see /proc/iomem) This
>> 2106 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
>> 2107 if the driver using a given range cannot be disabled.
3048 2108
3049 If unsure, say N. !! 2109 If in doubt, say Y.
3050 2110
3051 endmenu # "Rust" !! 2111 source "arch/$(SRCARCH)/Kconfig.debug"
3052 2112
3053 endmenu # Kernel hacking 2113 endmenu # Kernel hacking
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