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 167 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in 168 bool "Support symbolic error names in printf"
193 default y if PRINTK 169 default y if PRINTK
194 help 170 help
195 If you say Y here, the kernel's prin 171 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error name 172 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kerne 173 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel 174 (about 3KB), but can make the kernel logs easier to read.
199 175
200 config DEBUG_BUGVERBOSE 176 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70 177 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE 178 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y 179 default y
204 help 180 help
205 Say Y here to make BUG() panics outp 181 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP a 182 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of 183 debugging but costs about 70-100K of memory.
208 184
209 endmenu # "printk and dmesg options" 185 endmenu # "printk and dmesg options"
210 186
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 187 menu "Compile-time checks and compiler options"
226 188
227 config DEBUG_INFO 189 config DEBUG_INFO
228 bool !! 190 bool "Compile the kernel with debug info"
>> 191 depends on DEBUG_KERNEL && !COMPILE_TEST
229 help 192 help
230 A kernel debug info option other tha !! 193 If you say Y here the resulting kernel image will include
231 in the "Debug information" choice be !! 194 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 195 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 196 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 197 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
>> 198 Say Y here only if you plan to debug the kernel.
249 199
250 Choose which version of DWARF debug !! 200 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 <<
304 201
305 config DEBUG_INFO_REDUCED 202 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 203 bool "Reduce debugging information"
>> 204 depends on DEBUG_INFO
307 help 205 help
308 If you say Y here gcc is instructed 206 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 207 information for structure types. This means that tools that
310 need full debugging information (lik 208 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 209 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 210 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 211 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 212 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 213 Only works with newer gcc versions.
316 214
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 215 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 216 bool "Produce split debuginfo in .dwo files"
>> 217 depends on DEBUG_INFO
359 depends on $(cc-option,-gsplit-dwarf) 218 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 219 help
366 Generate debug info into separate .d 220 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 221 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 222 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 223 files instead of multiple times in object files and executables.
370 In addition the debug information is 224 In addition the debug information is also compressed.
371 225
372 Requires recent gcc (4.7+) and recen 226 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 227 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 228 to know about the .dwo files and include them.
375 Incompatible with older versions of 229 Incompatible with older versions of ccache.
376 230
>> 231 config DEBUG_INFO_DWARF4
>> 232 bool "Generate dwarf4 debuginfo"
>> 233 depends on DEBUG_INFO
>> 234 depends on $(cc-option,-gdwarf-4)
>> 235 help
>> 236 Generate dwarf4 debug info. This requires recent versions
>> 237 of gcc and gdb. It makes the debug information larger.
>> 238 But it significantly improves the success of resolving
>> 239 variables in gdb on optimized code.
>> 240
377 config DEBUG_INFO_BTF 241 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 242 bool "Generate BTF typeinfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG !! 243 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 244 help
386 Generate deduplicated BTF type infor 245 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 246 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 247 DWARF type info into equivalent deduplicated BTF type info.
389 248
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 249 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 250 bool "Provide GDB scripts for kernel debugging"
>> 251 depends on DEBUG_INFO
429 help 252 help
430 This creates the required links to G 253 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 254 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 255 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 256 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 257 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 258 for further details.
436 259
437 endif # DEBUG_INFO !! 260 config ENABLE_MUST_CHECK
>> 261 bool "Enable __must_check logic"
>> 262 default y
>> 263 help
>> 264 Enable the __must_check logic in the kernel build. Disable this to
>> 265 suppress the "warning: ignoring return value of 'foo', declared with
>> 266 attribute warn_unused_result" messages.
438 267
439 config FRAME_WARN 268 config FRAME_WARN
440 int "Warn for stack frames larger than !! 269 int "Warn for stack frames larger than (needs gcc 4.4)"
441 range 0 8192 270 range 0 8192
442 default 0 if KMSAN <<
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 271 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC !! 272 default 1280 if (!64BIT && PARISC)
445 default 1536 if (!64BIT && XTENSA) !! 273 default 1024 if (!64BIT && !PARISC)
446 default 1280 if KASAN && !64BIT <<
447 default 1024 if !64BIT <<
448 default 2048 if 64BIT 274 default 2048 if 64BIT
449 help 275 help
450 Tell the compiler to warn at build t !! 276 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 277 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 278 Setting it to 0 disables the warning.
>> 279 Requires gcc 4.4
453 280
454 config STRIP_ASM_SYMS 281 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 282 bool "Strip assembler-generated symbols during link"
456 default n 283 default n
457 help 284 help
458 Strip internal assembler-generated s 285 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 286 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 287 get_wchan() and suchlike.
461 288
462 config READABLE_ASM 289 config READABLE_ASM
463 bool "Generate readable assembler code 290 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 291 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC <<
466 help 292 help
467 Disable some compiler optimizations 293 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 294 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 295 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 296 sane.
471 297
472 config HEADERS_INSTALL 298 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 299 bool "Install uapi headers to usr/include"
474 depends on !UML 300 depends on !UML
475 help 301 help
476 This option will install uapi header 302 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 303 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 304 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 305 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 306 as uapi header sanity checks.
481 307
>> 308 config OPTIMIZE_INLINING
>> 309 def_bool y
>> 310 help
>> 311 This option determines if the kernel forces gcc to inline the functions
>> 312 developers have marked 'inline'. Doing so takes away freedom from gcc to
>> 313 do what it thinks is best, which is desirable for the gcc 3.x series of
>> 314 compilers. The gcc 4.x series have a rewritten inlining algorithm and
>> 315 enabling this option will generate a smaller kernel there. Hopefully
>> 316 this algorithm is so good that allowing gcc 4.x and above to make the
>> 317 decision will become the default in the future. Until then this option
>> 318 is there to test gcc for this.
>> 319
482 config DEBUG_SECTION_MISMATCH 320 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 321 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 322 help
486 The section mismatch analysis checks 323 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 324 references from one section to another section.
488 During linktime or runtime, some sec 325 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 326 any use of code/data previously in these sections would
490 most likely result in an oops. 327 most likely result in an oops.
491 In the code, functions and variables 328 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 329 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 330 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 331 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 332 kernel build, and enabling this option causes the following
496 additional step to occur: 333 additional step to occur:
497 - Add the option -fno-inline-functio 334 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 335 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 336 function, we would lose the section information and thus
500 the analysis would not catch the i 337 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 338 This option tells gcc to inline less (but it does result in
502 a larger kernel). 339 a larger kernel).
503 340
504 config SECTION_MISMATCH_WARN_ONLY 341 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 342 bool "Make section mismatch errors non-fatal"
506 default y 343 default y
507 help 344 help
508 If you say N here, the build process 345 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 346 section mismatch, instead of just throwing warnings.
510 347
511 If unsure, say Y. 348 If unsure, say Y.
512 349
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 # 350 #
527 # Select this config option from the architect 351 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 352 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 353 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 354 #
531 config ARCH_WANT_FRAME_POINTERS 355 config ARCH_WANT_FRAME_POINTERS
532 bool 356 bool
533 357
534 config FRAME_POINTER 358 config FRAME_POINTER
535 bool "Compile the kernel with frame po 359 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 360 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 361 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 362 help
539 If you say Y here the resulting kern 363 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 364 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 365 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 366
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 367 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 368 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 369 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 370 default n
551 help 371 help
552 Validate frame pointer rules at comp !! 372 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 373 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 374 that runtime stack traces are more reliable.
554 375
555 For more information, see !! 376 This is also a prerequisite for generation of ORC unwind data, which
556 tools/objtool/Documentation/objtool. !! 377 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 <<
563 378
564 config VMLINUX_MAP !! 379 For more information, see
565 bool "Generate vmlinux.map file when l !! 380 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 <<
573 381
574 config DEBUG_FORCE_WEAK_PER_CPU 382 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 383 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 384 depends on DEBUG_KERNEL
577 help 385 help
578 s390 and alpha require percpu variab 386 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 387 defined weak to work around addressing range issue which
580 puts the following two restrictions 388 puts the following two restrictions on percpu variable
581 definitions. 389 definitions.
582 390
583 1. percpu symbols must be unique whe 391 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 392 2. percpu variables can't be defined inside a function
585 393
586 To ensure that generic code follows 394 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 395 option forces all percpu variables to be defined as weak.
588 396
589 endmenu # "Compiler options" 397 endmenu # "Compiler options"
590 398
591 menu "Generic Kernel Debugging Instruments" 399 menu "Generic Kernel Debugging Instruments"
592 400
593 config MAGIC_SYSRQ 401 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 402 bool "Magic SysRq key"
595 depends on !UML 403 depends on !UML
596 help 404 help
597 If you say Y here, you will have som 405 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 406 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 407 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 408 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 409 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 410 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 411 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 412 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 413 Don't say Y unless you really know what this hack does.
606 414
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 415 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 416 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 417 depends on MAGIC_SYSRQ
610 default 0x1 418 default 0x1
611 help 419 help
612 Specifies which SysRq key functions 420 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 421 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 422 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 423
616 config MAGIC_SYSRQ_SERIAL 424 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 425 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 426 depends on MAGIC_SYSRQ
619 default y 427 default y
620 help 428 help
621 Many embedded boards have a disconne 429 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 430 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 431 This option allows you to decide whether you want to enable the
624 magic SysRq key. 432 magic SysRq key.
625 433
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE <<
627 string "Char sequence that enables mag <<
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 434 config DEBUG_FS
637 bool "Debug Filesystem" 435 bool "Debug Filesystem"
638 help 436 help
639 debugfs is a virtual file system tha 437 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 438 debugging files into. Enable this option to be able to read and
641 write to these files. 439 write to these files.
642 440
643 For detailed documentation on the de 441 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 442 Documentation/filesystems/.
645 443
646 If unsure, say N. 444 If unsure, say N.
647 445
648 choice <<
649 prompt "Debugfs default access" <<
650 depends on DEBUG_FS <<
651 default DEBUG_FS_ALLOW_ALL <<
652 help <<
653 This selects the default access rest <<
654 It can be overridden with kernel com <<
655 debugfs=[on,no-mount,off]. The restr <<
656 and filesystem registration. <<
657 <<
658 config DEBUG_FS_ALLOW_ALL <<
659 bool "Access normal" <<
660 help <<
661 No restrictions apply. Both API and <<
662 is on. This is the normal default op <<
663 <<
664 config DEBUG_FS_DISALLOW_MOUNT <<
665 bool "Do not register debugfs as files <<
666 help <<
667 The API is open but filesystem is no <<
668 their work and read with debug tools <<
669 debugfs filesystem. <<
670 <<
671 config DEBUG_FS_ALLOW_NONE <<
672 bool "No access" <<
673 help <<
674 Access is off. Clients get -PERM whe <<
675 debugfs tree and debugfs is not regi <<
676 Client can then back-off or continue <<
677 <<
678 endchoice <<
679 <<
680 source "lib/Kconfig.kgdb" 446 source "lib/Kconfig.kgdb"
>> 447
681 source "lib/Kconfig.ubsan" 448 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" <<
683 449
684 endmenu 450 endmenu
685 451
686 menu "Networking Debugging" !! 452 config DEBUG_KERNEL
>> 453 bool "Kernel debugging"
>> 454 help
>> 455 Say Y here if you are developing drivers or trying to debug and
>> 456 identify kernel problems.
687 457
688 source "net/Kconfig.debug" !! 458 config DEBUG_MISC
>> 459 bool "Miscellaneous debug code"
>> 460 default DEBUG_KERNEL
>> 461 depends on DEBUG_KERNEL
>> 462 help
>> 463 Say Y here if you need to enable miscellaneous debug code that should
>> 464 be under a more specific debug option but isn't.
689 465
690 endmenu # "Networking Debugging" <<
691 466
692 menu "Memory Debugging" 467 menu "Memory Debugging"
693 468
694 source "mm/Kconfig.debug" 469 source "mm/Kconfig.debug"
695 470
696 config DEBUG_OBJECTS 471 config DEBUG_OBJECTS
697 bool "Debug object operations" 472 bool "Debug object operations"
698 depends on DEBUG_KERNEL 473 depends on DEBUG_KERNEL
699 help 474 help
700 If you say Y here, additional code w 475 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 476 kernel to track the life time of various objects and validate
702 the operations on those objects. 477 the operations on those objects.
703 478
704 config DEBUG_OBJECTS_SELFTEST 479 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 480 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 481 depends on DEBUG_OBJECTS
707 help 482 help
708 This enables the selftest of the obj 483 This enables the selftest of the object debug code.
709 484
710 config DEBUG_OBJECTS_FREE 485 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 486 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 487 depends on DEBUG_OBJECTS
713 help 488 help
714 This enables checks whether a k/v fr 489 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 490 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 491 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 492 much slower.
718 493
719 config DEBUG_OBJECTS_TIMERS 494 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 495 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 496 depends on DEBUG_OBJECTS
722 help 497 help
723 If you say Y here, additional code w 498 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 499 timer routines to track the life time of timer objects and
725 validate the timer operations. 500 validate the timer operations.
726 501
727 config DEBUG_OBJECTS_WORK 502 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 503 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 504 depends on DEBUG_OBJECTS
730 help 505 help
731 If you say Y here, additional code w 506 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 507 work queue routines to track the life time of work objects and
733 validate the work operations. 508 validate the work operations.
734 509
735 config DEBUG_OBJECTS_RCU_HEAD 510 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 511 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 512 depends on DEBUG_OBJECTS
738 help 513 help
739 Enable this to turn on debugging of 514 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 515
741 config DEBUG_OBJECTS_PERCPU_COUNTER 516 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 517 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 518 depends on DEBUG_OBJECTS
744 help 519 help
745 If you say Y here, additional code w 520 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 521 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 522 objects and validate the percpu counter operations.
748 523
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 524 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 525 int "debug_objects bootup default value (0-1)"
751 range 0 1 526 range 0 1
752 default "1" 527 default "1"
753 depends on DEBUG_OBJECTS 528 depends on DEBUG_OBJECTS
754 help 529 help
755 Debug objects boot parameter default 530 Debug objects boot parameter default value
756 531
757 config SHRINKER_DEBUG !! 532 config DEBUG_SLAB
758 bool "Enable shrinker debugging suppor !! 533 bool "Debug slab memory allocations"
759 depends on DEBUG_FS !! 534 depends on DEBUG_KERNEL && SLAB
>> 535 help
>> 536 Say Y here to have the kernel do limited verification on memory
>> 537 allocation as well as poisoning memory on free to catch use of freed
>> 538 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 539
>> 540 config SLUB_DEBUG_ON
>> 541 bool "SLUB debugging on by default"
>> 542 depends on SLUB && SLUB_DEBUG
>> 543 default n
>> 544 help
>> 545 Boot with debugging on by default. SLUB boots by default with
>> 546 the runtime debug capabilities switched off. Enabling this is
>> 547 equivalent to specifying the "slub_debug" parameter on boot.
>> 548 There is no support for more fine grained debug control like
>> 549 possible with slub_debug=xxx. SLUB debugging may be switched
>> 550 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 551 "slub_debug=-".
>> 552
>> 553 config SLUB_STATS
>> 554 default n
>> 555 bool "Enable SLUB performance statistics"
>> 556 depends on SLUB && SYSFS
>> 557 help
>> 558 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 559 order find ways to optimize the allocator. This should never be
>> 560 enabled for production use since keeping statistics slows down
>> 561 the allocator by a few percentage points. The slabinfo command
>> 562 supports the determination of the most active slabs to figure
>> 563 out which slabs are relevant to a particular load.
>> 564 Try running: slabinfo -DA
>> 565
>> 566 config HAVE_DEBUG_KMEMLEAK
>> 567 bool
>> 568
>> 569 config DEBUG_KMEMLEAK
>> 570 bool "Kernel memory leak detector"
>> 571 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 572 select DEBUG_FS
>> 573 select STACKTRACE if STACKTRACE_SUPPORT
>> 574 select KALLSYMS
>> 575 select CRC32
760 help 576 help
761 Say Y to enable the shrinker debugfs !! 577 Say Y here if you want to enable the memory leak
762 visibility into the kernel memory sh !! 578 detector. The memory allocation/freeing is traced in a way
763 Disable it to avoid an extra memory !! 579 similar to the Boehm's conservative garbage collector, the
>> 580 difference being that the orphan objects are not freed but
>> 581 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 582 feature will introduce an overhead to memory
>> 583 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 584 details.
>> 585
>> 586 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
>> 587 of finding leaks due to the slab objects poisoning.
>> 588
>> 589 In order to access the kmemleak file, debugfs needs to be
>> 590 mounted (usually at /sys/kernel/debug).
>> 591
>> 592 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
>> 593 int "Kmemleak memory pool size"
>> 594 depends on DEBUG_KMEMLEAK
>> 595 range 200 1000000
>> 596 default 16000
>> 597 help
>> 598 Kmemleak must track all the memory allocations to avoid
>> 599 reporting false positives. Since memory may be allocated or
>> 600 freed before kmemleak is fully initialised, use a static pool
>> 601 of metadata objects to track such callbacks. After kmemleak is
>> 602 fully initialised, this memory pool acts as an emergency one
>> 603 if slab allocations fail.
>> 604
>> 605 config DEBUG_KMEMLEAK_TEST
>> 606 tristate "Simple test for the kernel memory leak detector"
>> 607 depends on DEBUG_KMEMLEAK && m
>> 608 help
>> 609 This option enables a module that explicitly leaks memory.
>> 610
>> 611 If unsure, say N.
>> 612
>> 613 config DEBUG_KMEMLEAK_DEFAULT_OFF
>> 614 bool "Default kmemleak to off"
>> 615 depends on DEBUG_KMEMLEAK
>> 616 help
>> 617 Say Y here to disable kmemleak by default. It can then be enabled
>> 618 on the command line via kmemleak=on.
>> 619
>> 620 config DEBUG_KMEMLEAK_AUTO_SCAN
>> 621 bool "Enable kmemleak auto scan thread on boot up"
>> 622 default y
>> 623 depends on DEBUG_KMEMLEAK
>> 624 help
>> 625 Depending on the cpu, kmemleak scan may be cpu intensive and can
>> 626 stall user tasks at times. This option enables/disables automatic
>> 627 kmemleak scan at boot up.
>> 628
>> 629 Say N here to disable kmemleak auto scan thread to stop automatic
>> 630 scanning. Disabling this option disables automatic reporting of
>> 631 memory leaks.
>> 632
>> 633 If unsure, say Y.
764 634
765 config DEBUG_STACK_USAGE 635 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 636 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 637 depends on DEBUG_KERNEL && !IA64
768 help 638 help
769 Enables the display of the minimum a 639 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 640 task has ever had available in the sysrq-T and sysrq-P debug output.
771 Also emits a message to dmesg when a <<
772 used more stack space than previousl <<
773 641
774 This option will slow down process c 642 This option will slow down process creation somewhat.
775 643
776 config SCHED_STACK_END_CHECK 644 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 645 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 646 depends on DEBUG_KERNEL
779 default n 647 default n
780 help 648 help
781 This option checks for a stack overr 649 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 650 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 651 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 652 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 653 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 654 is examined. The runtime overhead introduced is minimal.
787 655
788 config ARCH_HAS_DEBUG_VM_PGTABLE <<
789 bool <<
790 help <<
791 An architecture should select this w <<
792 build and run DEBUG_VM_PGTABLE. <<
793 <<
794 config DEBUG_VM_IRQSOFF <<
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 <<
797 config DEBUG_VM 656 config DEBUG_VM
798 bool "Debug VM" 657 bool "Debug VM"
799 depends on DEBUG_KERNEL 658 depends on DEBUG_KERNEL
800 help 659 help
801 Enable this to turn on extended chec 660 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 661 that may impact performance.
803 662
804 If unsure, say N. 663 If unsure, say N.
805 664
806 config DEBUG_VM_SHOOT_LAZIES !! 665 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 666 bool "Debug VMA caching"
808 depends on DEBUG_VM <<
809 depends on MMU_LAZY_TLB_SHOOTDOWN <<
810 help <<
811 Enable additional IPIs that ensure l <<
812 before the mm is freed. <<
813 <<
814 If unsure, say N. <<
815 <<
816 config DEBUG_VM_MAPLE_TREE <<
817 bool "Debug VM maple trees" <<
818 depends on DEBUG_VM 667 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE <<
820 help 668 help
821 Enable VM maple tree debugging infor !! 669 Enable this to turn on VMA caching debug information. Doing so
>> 670 can cause significant overhead, so only enable it in non-production
>> 671 environments.
822 672
823 If unsure, say N. 673 If unsure, say N.
824 674
825 config DEBUG_VM_RB 675 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 676 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 677 depends on DEBUG_VM
828 help 678 help
829 Enable VM red-black tree debugging i 679 Enable VM red-black tree debugging information and extra validations.
830 680
831 If unsure, say N. 681 If unsure, say N.
832 682
833 config DEBUG_VM_PGFLAGS 683 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 684 bool "Debug page-flags operations"
835 depends on DEBUG_VM 685 depends on DEBUG_VM
836 help 686 help
837 Enables extra validation on page fla 687 Enables extra validation on page flags operations.
838 688
839 If unsure, say N. 689 If unsure, say N.
840 690
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 691 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 692 bool
859 693
860 config DEBUG_VIRTUAL 694 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 695 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 696 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 697 help
864 Enable some costly sanity checks in 698 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 699 catch mistakes with virt_to_page() and friends.
866 700
867 If unsure, say N. 701 If unsure, say N.
868 702
869 config DEBUG_NOMMU_REGIONS 703 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 704 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 705 depends on DEBUG_KERNEL && !MMU
872 help 706 help
873 This option causes the global tree o 707 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 708 regions to be regularly checked for invalid topology.
875 709
876 config DEBUG_MEMORY_INIT 710 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 711 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 712 default !EXPERT
879 help 713 help
880 Enable this for additional checks du 714 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 715 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 716 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 717 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 718 on the mminit_loglevel= command-line option.
885 719
886 If unsure, say Y 720 If unsure, say Y
887 721
888 config MEMORY_NOTIFIER_ERROR_INJECT 722 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 723 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 724 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 725 help
892 This option provides the ability to 726 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 727 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 728 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 729
896 If the notifier call chain should be 730 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 731 notified, write the error code to "actions/<notifier event>/error".
898 732
899 Example: Inject memory hotplug offli 733 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 734
901 # cd /sys/kernel/debug/notifier-erro 735 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 736 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 737 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 738 bash: echo: write error: Cannot allocate memory
905 739
906 To compile this code as a module, ch 740 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 741 be called memory-notifier-error-inject.
908 742
909 If unsure, say N. 743 If unsure, say N.
910 744
911 config DEBUG_PER_CPU_MAPS 745 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 746 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 747 depends on DEBUG_KERNEL
914 depends on SMP 748 depends on SMP
915 help 749 help
916 Say Y to verify that the per_cpu map 750 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 751 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 752 and decreases performance.
919 753
920 Say N if unsure. 754 Say N if unsure.
921 755
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 756 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 757 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 758 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A <<
946 select DEBUG_KMAP_LOCAL <<
947 help 759 help
948 This option enables additional error 760 This option enables additional error checking for high memory
949 systems. Disable for production sys 761 systems. Disable for production systems.
950 762
951 config HAVE_DEBUG_STACKOVERFLOW 763 config HAVE_DEBUG_STACKOVERFLOW
952 bool 764 bool
953 765
954 config DEBUG_STACKOVERFLOW 766 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 767 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 768 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help !! 769 ---help---
958 Say Y here if you want to check for 770 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 771 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 772 option will show detailed messages if free stack space drops
961 below a certain limit. 773 below a certain limit.
962 774
963 These kinds of bugs usually occur wh 775 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 776 kernel get too deep, especially when interrupts are
965 involved. 777 involved.
966 778
967 Use this in cases where you see appa 779 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 780 corruption, especially if it appears in 'struct thread_info'
969 781
970 If in doubt, say "N". 782 If in doubt, say "N".
971 783
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" 784 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" <<
1005 source "lib/Kconfig.kmsan" <<
1006 785
1007 endmenu # "Memory Debugging" 786 endmenu # "Memory Debugging"
1008 787
1009 config DEBUG_SHIRQ 788 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 789 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 790 depends on DEBUG_KERNEL
1012 help 791 help
1013 Enable this to generate a spurious !! 792 Enable this to generate a spurious interrupt as soon as a shared
1014 interrupt handler is deregistered ( !! 793 interrupt handler is registered, and just before one is deregistered.
1015 is currently disabled). Drivers nee !! 794 Drivers ought to be able to handle interrupts coming in at those
1016 don't and need to be caught. !! 795 points; some don't and need to be caught.
1017 796
1018 menu "Debug Oops, Lockups and Hangs" 797 menu "Debug Oops, Lockups and Hangs"
1019 798
1020 config PANIC_ON_OOPS 799 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 800 bool "Panic on Oops"
1022 help 801 help
1023 Say Y here to enable the kernel to 802 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 803 has the same effect as setting oops=panic on the kernel command
1025 line. 804 line.
1026 805
1027 This feature is useful to ensure th 806 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 807 anything erroneous after an oops which could result in data
1029 corruption or other issues. 808 corruption or other issues.
1030 809
1031 Say N if unsure. 810 Say N if unsure.
1032 811
1033 config PANIC_ON_OOPS_VALUE 812 config PANIC_ON_OOPS_VALUE
1034 int 813 int
1035 range 0 1 814 range 0 1
1036 default 0 if !PANIC_ON_OOPS 815 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 816 default 1 if PANIC_ON_OOPS
1038 817
1039 config PANIC_TIMEOUT 818 config PANIC_TIMEOUT
1040 int "panic timeout" 819 int "panic timeout"
1041 default 0 820 default 0
1042 help 821 help
1043 Set the timeout value (in seconds) !! 822 Set the timeout value (in seconds) until a reboot occurs when the
1044 the kernel panics. If n = 0, then w 823 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 824 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 825 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 826
1050 config LOCKUP_DETECTOR 827 config LOCKUP_DETECTOR
1051 bool 828 bool
1052 829
1053 config SOFTLOCKUP_DETECTOR 830 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 831 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 832 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 833 select LOCKUP_DETECTOR
1057 help 834 help
1058 Say Y here to enable the kernel to 835 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 836 soft lockups.
1060 837
1061 Softlockups are bugs that cause the 838 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 839 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 840 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 841 detection and the system will stay locked up.
1065 842
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 843 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 844 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 845 depends on SOFTLOCKUP_DETECTOR
1083 help 846 help
1084 Say Y here to enable the kernel to 847 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 848 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 849 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 850 sysctl), without giving other tasks a chance to run.
1088 851
1089 The panic can be used in combinatio 852 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 853 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 854 lockup has been detected. This feature is useful for
1092 high-availability systems that have 855 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 856 where a lockup must be resolved ASAP.
1094 857
1095 Say N if unsure. 858 Say N if unsure.
1096 859
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 860 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 861 int
>> 862 depends on SOFTLOCKUP_DETECTOR
>> 863 range 0 1
>> 864 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 865 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 866
>> 867 config HARDLOCKUP_DETECTOR_PERF
1098 bool 868 bool
1099 depends on SMP !! 869 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 870
1102 # 871 #
1103 # Global switch whether to build a hardlockup !! 872 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 873 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 874 #
1107 # s390: it reported many false positive !! 875 config HARDLOCKUP_CHECK_TIMESTAMP
>> 876 bool
>> 877
1108 # 878 #
1109 # sparc64: has a custom implementation !! 879 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 880 # lockup detector rather than the perf based detector.
1111 # 881 #
1112 config HARDLOCKUP_DETECTOR 882 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 883 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 884 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 885 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 886 select LOCKUP_DETECTOR
1120 !! 887 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
>> 888 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121 help 889 help
1122 Say Y here to enable the kernel to 890 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 891 hard lockups.
1124 892
1125 Hardlockups are bugs that cause the 893 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 894 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 895 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 896 and the system will stay locked up.
1129 897
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 898 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 899 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 900 depends on HARDLOCKUP_DETECTOR
1190 help 901 help
1191 Say Y here to enable the kernel to 902 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 903 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 904 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 905 using the watchdog_thresh sysctl).
1195 906
1196 Say N if unsure. 907 Say N if unsure.
1197 908
>> 909 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 910 int
>> 911 depends on HARDLOCKUP_DETECTOR
>> 912 range 0 1
>> 913 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 914 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 915
1198 config DETECT_HUNG_TASK 916 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 917 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 918 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 919 default SOFTLOCKUP_DETECTOR
1202 help 920 help
1203 Say Y here to enable the kernel to 921 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 922 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 923 uninterruptible "D" state indefinitely.
1206 924
1207 When a hung task is detected, the k 925 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 926 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 927 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 928 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 929 feature has negligible overhead.
1212 930
1213 config DEFAULT_HUNG_TASK_TIMEOUT 931 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 932 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 933 depends on DETECT_HUNG_TASK
1216 default 120 934 default 120
1217 help 935 help
1218 This option controls the default ti 936 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 937 to determine when a task has become non-responsive and should
1220 be considered hung. 938 be considered hung.
1221 939
1222 It can be adjusted at runtime via t 940 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 941 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 942 /proc/sys/kernel/hung_task_timeout_secs.
1225 943
1226 A timeout of 0 disables the check. 944 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 945 Keeping the default should be fine in most cases.
1228 946
1229 config BOOTPARAM_HUNG_TASK_PANIC 947 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 948 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 949 depends on DETECT_HUNG_TASK
1232 help 950 help
1233 Say Y here to enable the kernel to 951 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 952 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 953 in uninterruptible "D" state.
1236 954
1237 The panic can be used in combinatio 955 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 956 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 957 hung task has been detected. This feature is useful for
1240 high-availability systems that have 958 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 959 where a hung tasks must be resolved ASAP.
1242 960
1243 Say N if unsure. 961 Say N if unsure.
1244 962
>> 963 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 964 int
>> 965 depends on DETECT_HUNG_TASK
>> 966 range 0 1
>> 967 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 968 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 969
1245 config WQ_WATCHDOG 970 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 971 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 972 depends on DEBUG_KERNEL
1248 help 973 help
1249 Say Y here to enable stall detectio 974 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 975 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 976 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 977 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 978 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 979 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 980
1256 config WQ_CPU_INTENSIVE_REPORT <<
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 <<
1269 config TEST_LOCKUP <<
1270 tristate "Test module to generate loc <<
1271 depends on m <<
1272 help <<
1273 This builds the "test_lockup" modul <<
1274 that watchdogs and lockup detectors <<
1275 <<
1276 Depending on module parameters it c <<
1277 lockup, "hung task", or locking arb <<
1278 Also it could generate series of lo <<
1279 <<
1280 If unsure, say N. <<
1281 <<
1282 endmenu # "Debug lockups and hangs" 981 endmenu # "Debug lockups and hangs"
1283 982
1284 menu "Scheduler Debugging" 983 menu "Scheduler Debugging"
1285 984
1286 config SCHED_DEBUG 985 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 986 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 987 depends on DEBUG_KERNEL && PROC_FS
1289 default y 988 default y
1290 help 989 help
1291 If you say Y here, the /sys/kernel/ !! 990 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 991 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 992 option is minimal.
1294 993
1295 config SCHED_INFO 994 config SCHED_INFO
1296 bool 995 bool
1297 default n 996 default n
1298 997
1299 config SCHEDSTATS 998 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 999 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1000 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1001 select SCHED_INFO
1303 help 1002 help
1304 If you say Y here, additional code 1003 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1004 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1005 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1006 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1007 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1008 application, you can say N to avoid the very slight overhead
1310 this adds. 1009 this adds.
1311 1010
1312 endmenu 1011 endmenu
1313 1012
1314 config DEBUG_TIMEKEEPING 1013 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1014 bool "Enable extra timekeeping sanity checking"
1316 help 1015 help
1317 This option will enable additional 1016 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1017 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1018 problems are suspected.
1320 1019
1321 This may include checks in the time 1020 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1021 option may have a (very small) performance impact to some
1323 workloads. 1022 workloads.
1324 1023
1325 If unsure, say N. 1024 If unsure, say N.
1326 1025
1327 config DEBUG_PREEMPT 1026 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1027 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION !! 1028 depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
>> 1029 default y
1330 help 1030 help
1331 If you say Y here then the kernel w 1031 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1032 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1033 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1034 will detect preemption count underflows.
1335 1035
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 1036 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1037
1342 config LOCK_DEBUGGING_SUPPORT 1038 config LOCK_DEBUGGING_SUPPORT
1343 bool 1039 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1040 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1041 default y
1346 1042
1347 config PROVE_LOCKING 1043 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1044 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1045 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1046 select LOCKDEP
1351 select DEBUG_SPINLOCK 1047 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1048 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1049 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1050 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1051 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1052 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE <<
1358 select TRACE_IRQFLAGS 1053 select TRACE_IRQFLAGS
1359 default n 1054 default n
1360 help 1055 help
1361 This feature enables the kernel to p 1056 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1057 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1058 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1059 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1060 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1061 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1062 deadlock.
1368 1063
1369 In short, this feature enables the k 1064 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1065 related deadlocks before they actually occur.
1371 1066
1372 The proof does not depend on how har 1067 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1068 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1069 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1070 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1071 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1072 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1073 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1074 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1075 makes the deadlock theoretically possible).
1381 1076
1382 If a deadlock is impossible (i.e. th 1077 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1078 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1079 kernel reports nothing.
1385 1080
1386 NOTE: this feature can also be enabl 1081 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1082 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1083 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1084 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1085 arbitrary combination of these separate locking variants.
1391 1086
1392 For more details, see Documentation/ 1087 For more details, see Documentation/locking/lockdep-design.rst.
1393 1088
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 <<
1411 config LOCK_STAT 1089 config LOCK_STAT
1412 bool "Lock usage statistics" 1090 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1091 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1092 select LOCKDEP
1415 select DEBUG_SPINLOCK 1093 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1094 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1095 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1096 select DEBUG_LOCK_ALLOC
1419 default n 1097 default n
1420 help 1098 help
1421 This feature enables tracking lock c 1099 This feature enables tracking lock contention points
1422 1100
1423 For more details, see Documentation/ 1101 For more details, see Documentation/locking/lockstat.rst
1424 1102
1425 This also enables lock events requir 1103 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1104 subcommand of perf.
1427 If you want to use "perf lock", you 1105 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1106 CONFIG_EVENT_TRACING.
1429 1107
1430 CONFIG_LOCK_STAT defines "contended" 1108 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1109 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1110
1433 config DEBUG_RT_MUTEXES 1111 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1112 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1113 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1114 help
1437 This allows rt mutex semantics viola 1115 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1116 deadlocks (lockups) to be detected and reported automatically.
1439 1117
1440 config DEBUG_SPINLOCK 1118 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1119 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1120 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1121 select UNINLINE_SPIN_UNLOCK
1444 help 1122 help
1445 Say Y here and build SMP to catch m 1123 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1124 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1125 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1126 deadlocks are also debuggable.
1449 1127
1450 config DEBUG_MUTEXES 1128 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1129 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1130 depends on DEBUG_KERNEL
1453 help 1131 help
1454 This feature allows mutex semantics 1132 This feature allows mutex semantics violations to be detected and
1455 reported. 1133 reported.
1456 1134
1457 config DEBUG_WW_MUTEX_SLOWPATH 1135 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1136 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1137 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1138 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1139 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1140 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1141 help
1465 This feature enables slowpath testin 1142 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1143 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1144 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1145 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1146 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1147 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1148 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1149 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1150 you are a distro, do not.
1474 1151
1475 config DEBUG_RWSEMS 1152 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1153 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1154 depends on DEBUG_KERNEL
1478 help 1155 help
1479 This debugging feature allows misma 1156 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1157 and unlocks to be detected and reported.
1481 1158
1482 config DEBUG_LOCK_ALLOC 1159 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1160 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1161 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1162 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1163 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1164 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1165 select LOCKDEP
1489 help 1166 help
1490 This feature will check whether any 1167 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1168 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1169 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1170 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1171 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1172 held during task exit.
1496 1173
1497 config LOCKDEP 1174 config LOCKDEP
1498 bool 1175 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1176 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1177 select STACKTRACE
>> 1178 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1501 select KALLSYMS 1179 select KALLSYMS
1502 select KALLSYMS_ALL 1180 select KALLSYMS_ALL
1503 1181
1504 config LOCKDEP_SMALL 1182 config LOCKDEP_SMALL
1505 bool 1183 bool
1506 1184
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 1185 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1186 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1187 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS <<
1551 help 1188 help
1552 If you say Y here, the lock depende 1189 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1190 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1191 of more runtime overhead.
1555 1192
1556 config DEBUG_ATOMIC_SLEEP 1193 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1194 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1195 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1196 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1197 depends on !ARCH_NO_PREEMPT
1561 help 1198 help
1562 If you say Y here, various routines 1199 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1200 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1201 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1202 sections, inside an interrupt, etc...
1566 1203
1567 config DEBUG_LOCKING_API_SELFTESTS 1204 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1205 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1206 depends on DEBUG_KERNEL
1570 help 1207 help
1571 Say Y here if you want the kernel t 1208 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1209 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1210 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1211 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1212 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1213 mutexes and rwsems.
1577 1214
1578 config LOCK_TORTURE_TEST 1215 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1216 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1217 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1218 select TORTURE_TEST
1582 help 1219 help
1583 This option provides a kernel modul 1220 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1221 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1222 after the fact on the running kernel to be tested, if desired.
1586 1223
1587 Say Y here if you want kernel locki 1224 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1225 to be built into the kernel.
1589 Say M if you want these torture tes 1226 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1227 Say N if you are unsure.
1591 1228
1592 config WW_MUTEX_SELFTEST 1229 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1230 tristate "Wait/wound mutex selftests"
1594 help 1231 help
1595 This option provides a kernel modul 1232 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1233 on the struct ww_mutex locking API.
1597 1234
1598 It is recommended to enable DEBUG_W 1235 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1236 with this test harness.
1600 1237
1601 Say M if you want these self tests 1238 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1239 Say N if you are unsure.
1603 1240
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 1241 endmenu # lock debugging
1635 1242
1636 config TRACE_IRQFLAGS 1243 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT <<
1638 bool 1244 bool
1639 help 1245 help
1640 Enables hooks to interrupt enabling 1246 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1247 either tracing or lock debugging.
1642 1248
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 1249 config STACKTRACE
1667 bool "Stack backtrace support" 1250 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1251 depends on STACKTRACE_SUPPORT
1669 help 1252 help
1670 This option causes the kernel to cr 1253 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1254 every process, showing its current stack trace.
1672 It is also used by various kernel d 1255 It is also used by various kernel debugging features that require
1673 stack trace generation. 1256 stack trace generation.
1674 1257
1675 config WARN_ALL_UNSEEDED_RANDOM 1258 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1259 bool "Warn for all uses of unseeded randomness"
1677 default n 1260 default n
1678 help 1261 help
1679 Some parts of the kernel contain bu 1262 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1263 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1264 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1265 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1266 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1267 are going wrong, so that they might contact developers about fixing
1685 it. 1268 it.
1686 1269
1687 Unfortunately, on some models of so 1270 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1271 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1272 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1273 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1274 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1275 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1276 However, since users cannot do anything actionable to
1694 address this, by default this optio !! 1277 address this, by default the kernel will issue only a single
>> 1278 warning for the first use of unseeded randomness.
1695 1279
1696 Say Y here if you want to receive w 1280 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1281 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1282 those developers interested in improving the security of
1699 Linux kernels running on their arch 1283 Linux kernels running on their architecture (or
1700 subarchitecture). 1284 subarchitecture).
1701 1285
1702 config DEBUG_KOBJECT 1286 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1287 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1288 depends on DEBUG_KERNEL
1705 help 1289 help
1706 If you say Y here, some extra kobje 1290 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1291 to the syslog.
1708 1292
1709 config DEBUG_KOBJECT_RELEASE 1293 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1294 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1295 depends on DEBUG_OBJECTS_TIMERS
1712 help 1296 help
1713 kobjects are reference counted obje 1297 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1298 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1299 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1300 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1301 example of this would be a struct device which has just been
1718 unregistered. 1302 unregistered.
1719 1303
1720 However, some buggy drivers assume 1304 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1305 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1306 goes completely against the principles of a refcounted object.
1723 1307
1724 If you say Y here, the kernel will 1308 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1309 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1310 kind of kobject release bug.
1727 1311
1728 config HAVE_DEBUG_BUGVERBOSE 1312 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1313 bool
1730 1314
1731 menu "Debug kernel data structures" 1315 menu "Debug kernel data structures"
1732 1316
1733 config DEBUG_LIST 1317 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1318 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1319 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1320 help
1738 Enable this to turn on extended che !! 1321 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1322 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 1323
1745 If unsure, say N. 1324 If unsure, say N.
1746 1325
1747 config DEBUG_PLIST 1326 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1327 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1328 depends on DEBUG_KERNEL
1750 help 1329 help
1751 Enable this to turn on extended che 1330 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1331 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1332 list multiple times during each manipulation.
1754 1333
1755 If unsure, say N. 1334 If unsure, say N.
1756 1335
1757 config DEBUG_SG 1336 config DEBUG_SG
1758 bool "Debug SG table operations" 1337 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1338 depends on DEBUG_KERNEL
1760 help 1339 help
1761 Enable this to turn on checks on sc 1340 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1341 help find problems with drivers that do not properly initialize
1763 their sg tables. 1342 their sg tables.
1764 1343
1765 If unsure, say N. 1344 If unsure, say N.
1766 1345
1767 config DEBUG_NOTIFIERS 1346 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1347 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1348 depends on DEBUG_KERNEL
1770 help 1349 help
1771 Enable this to turn on sanity check 1350 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1351 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1352 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1353 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1354 performance, say N.
1776 1355
1777 config DEBUG_CLOSURES !! 1356 config BUG_ON_DATA_CORRUPTION
1778 bool "Debug closures (bcache async wi !! 1357 bool "Trigger a BUG when data corruption is detected"
1779 depends on CLOSURES !! 1358 select DEBUG_LIST
1780 select DEBUG_FS !! 1359 help
1781 help !! 1360 Select this option if the kernel should BUG when it encounters
1782 Keeps all active closures in a link !! 1361 data corruption in kernel memory structures when they get checked
1783 interface to list them, which makes !! 1362 for validity.
1784 operations that get stuck. <<
1785 1363
1786 config DEBUG_MAPLE_TREE !! 1364 If unsure, say N.
1787 bool "Debug maple trees" !! 1365
>> 1366 endmenu
>> 1367
>> 1368 config DEBUG_CREDENTIALS
>> 1369 bool "Debug credential management"
1788 depends on DEBUG_KERNEL 1370 depends on DEBUG_KERNEL
1789 help 1371 help
1790 Enable maple tree debugging informa !! 1372 Enable this to turn on some debug checking for credential
>> 1373 management. The additional code keeps track of the number of
>> 1374 pointers from task_structs to any given cred struct, and checks to
>> 1375 see that this number never exceeds the usage count of the cred
>> 1376 struct.
1791 1377
1792 If unsure, say N. !! 1378 Furthermore, if SELinux is enabled, this also checks that the
>> 1379 security pointer in the cred struct is never seen to be invalid.
1793 1380
1794 endmenu !! 1381 If unsure, say N.
1795 1382
1796 source "kernel/rcu/Kconfig.debug" 1383 source "kernel/rcu/Kconfig.debug"
1797 1384
1798 config DEBUG_WQ_FORCE_RR_CPU 1385 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1386 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1387 depends on DEBUG_KERNEL
1801 default n 1388 default n
1802 help 1389 help
1803 Workqueue used to implicitly guaran 1390 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1391 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1392 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1393 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1394 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1395 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1396 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1397 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1398 be impacted.
1812 1399
>> 1400 config DEBUG_BLOCK_EXT_DEVT
>> 1401 bool "Force extended block device numbers and spread them"
>> 1402 depends on DEBUG_KERNEL
>> 1403 depends on BLOCK
>> 1404 default n
>> 1405 help
>> 1406 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1407 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1408 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1409 is broken.
>> 1410
>> 1411 Conventionally, block device numbers are allocated from
>> 1412 predetermined contiguous area. However, extended block area
>> 1413 may introduce non-contiguous block device numbers. This
>> 1414 option forces most block device numbers to be allocated from
>> 1415 the extended space and spreads them to discover kernel or
>> 1416 userland code paths which assume predetermined contiguous
>> 1417 device number allocation.
>> 1418
>> 1419 Note that turning on this debug option shuffles all the
>> 1420 device numbers for all IDE and SCSI devices including libata
>> 1421 ones, so root partition specified using device number
>> 1422 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1423 Textual device names (root=/dev/sdXn) will continue to work.
>> 1424
>> 1425 Say N if you are unsure.
>> 1426
1813 config CPU_HOTPLUG_STATE_CONTROL 1427 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1428 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1429 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1430 depends on HOTPLUG_CPU
1817 default n 1431 default n
1818 help 1432 help
1819 Allows to write steps between "offl 1433 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1434 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1435 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1436 restarted at arbitrary points yet.
1823 1437
1824 Say N if your are unsure. 1438 Say N if your are unsure.
1825 1439
1826 config LATENCYTOP 1440 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1441 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1442 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1443 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1444 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P !! 1445 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1832 select KALLSYMS 1446 select KALLSYMS
1833 select KALLSYMS_ALL 1447 select KALLSYMS_ALL
1834 select STACKTRACE 1448 select STACKTRACE
1835 select SCHEDSTATS 1449 select SCHEDSTATS
>> 1450 select SCHED_DEBUG
1836 help 1451 help
1837 Enable this option if you want to u 1452 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1453 to find out which userspace is blocking on what kernel operations.
1839 1454
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" 1455 source "kernel/trace/Kconfig"
1851 1456
1852 config PROVIDE_OHCI1394_DMA_INIT 1457 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1458 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1459 depends on PCI && X86
1855 help 1460 help
1856 If you want to debug problems which 1461 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1462 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1463 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1464 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1465 specification which is now the standard for FireWire controllers.
1861 1466
1862 With remote DMA, you can monitor th 1467 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1468 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1469 Even controlling a kernel debugger is possible using remote DMA.
1865 1470
1866 Usage: 1471 Usage:
1867 1472
1868 If ohci1394_dma=early is used as bo 1473 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1474 all OHCI1394 controllers which are found in the PCI config space.
1870 1475
1871 As all changes to the FireWire bus 1476 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1477 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1478 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1479 the debugging host before booting the debug target for debugging.
1875 1480
1876 This code (~1k) is freed after boot 1481 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1482 in charge of the OHCI-1394 controllers should be used instead.
1878 1483
1879 See Documentation/core-api/debuggin !! 1484 See Documentation/debugging-via-ohci1394.txt for more information.
1880 1485
1881 source "samples/Kconfig" 1486 source "samples/Kconfig"
1882 1487
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1488 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1489 bool
1885 1490
1886 config STRICT_DEVMEM 1491 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1492 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1493 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED !! 1494 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1495 default y if PPC || X86 || ARM64
1891 help 1496 help
1892 If this option is disabled, you all 1497 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1498 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1499 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1500 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1501 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1502 use due to the cache aliasing requirements.
1898 1503
1899 If this option is switched on, and 1504 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1505 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1506 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1507 users of /dev/mem.
1903 1508
1904 If in doubt, say Y. 1509 If in doubt, say Y.
1905 1510
1906 config IO_STRICT_DEVMEM 1511 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1512 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1513 depends on STRICT_DEVMEM
1909 help 1514 help
1910 If this option is disabled, you all 1515 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1516 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1517 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1518 specific access can be used by people debugging kernel drivers.
1914 1519
1915 If this option is switched on, the 1520 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1521 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1522 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1523 if the driver using a given range cannot be disabled.
1919 1524
1920 If in doubt, say Y. 1525 If in doubt, say Y.
1921 1526
1922 menu "$(SRCARCH) Debugging" 1527 menu "$(SRCARCH) Debugging"
1923 1528
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1529 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1530
1926 endmenu 1531 endmenu
1927 1532
1928 menu "Kernel Testing and Coverage" 1533 menu "Kernel Testing and Coverage"
1929 1534
1930 source "lib/kunit/Kconfig" 1535 source "lib/kunit/Kconfig"
1931 1536
1932 config NOTIFIER_ERROR_INJECTION 1537 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1538 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1539 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1540 select DEBUG_FS
1936 help 1541 help
1937 This option provides the ability to 1542 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1543 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1544 handling of notifier call chain failures.
1940 1545
1941 Say N if unsure. 1546 Say N if unsure.
1942 1547
1943 config PM_NOTIFIER_ERROR_INJECT 1548 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1549 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1550 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1551 default m if PM_DEBUG
1947 help 1552 help
1948 This option provides the ability to 1553 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1554 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1555 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1556
1952 If the notifier call chain should b 1557 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1558 notified, write the error code to "actions/<notifier event>/error".
1954 1559
1955 Example: Inject PM suspend error (- 1560 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1561
1957 # cd /sys/kernel/debug/notifier-err 1562 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1563 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1564 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1565 bash: echo: write error: Cannot allocate memory
1961 1566
1962 To compile this code as a module, c 1567 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1568 be called pm-notifier-error-inject.
1964 1569
1965 If unsure, say N. 1570 If unsure, say N.
1966 1571
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1572 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1573 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1574 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1575 help
1971 This option provides the ability to 1576 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1577 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1578 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1579 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1580
1976 If the notifier call chain should b 1581 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1582 notified, write the error code to "actions/<notifier event>/error".
1978 1583
1979 To compile this code as a module, c 1584 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1585 be called of-reconfig-notifier-error-inject.
1981 1586
1982 If unsure, say N. 1587 If unsure, say N.
1983 1588
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1589 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1590 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1591 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1592 help
1988 This option provides the ability to 1593 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1594 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1595 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1596
1992 If the notifier call chain should b 1597 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1598 notified, write the error code to "actions/<notifier event>/error".
1994 1599
1995 Example: Inject netdevice mtu chang 1600 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1601
1997 # cd /sys/kernel/debug/notifier-err 1602 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1603 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1604 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1605 RTNETLINK answers: Invalid argument
2001 1606
2002 To compile this code as a module, c 1607 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1608 be called netdev-notifier-error-inject.
2004 1609
2005 If unsure, say N. 1610 If unsure, say N.
2006 1611
2007 config FUNCTION_ERROR_INJECTION 1612 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" !! 1613 def_bool y
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1614 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 1615
2017 config FAULT_INJECTION 1616 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1617 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1618 depends on DEBUG_KERNEL
2020 help 1619 help
2021 Provide fault-injection framework. 1620 Provide fault-injection framework.
2022 For more details, see Documentation 1621 For more details, see Documentation/fault-injection/.
2023 1622
2024 config FAILSLAB 1623 config FAILSLAB
2025 bool "Fault-injection capability for 1624 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1625 depends on FAULT_INJECTION
>> 1626 depends on SLAB || SLUB
2027 help 1627 help
2028 Provide fault-injection capability 1628 Provide fault-injection capability for kmalloc.
2029 1629
2030 config FAIL_PAGE_ALLOC 1630 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for !! 1631 bool "Fault-injection capabilitiy for alloc_pages()"
2032 depends on FAULT_INJECTION 1632 depends on FAULT_INJECTION
2033 help 1633 help
2034 Provide fault-injection capability 1634 Provide fault-injection capability for alloc_pages().
2035 1635
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 1636 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1637 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1638 depends on FAULT_INJECTION && BLOCK
2046 help 1639 help
2047 Provide fault-injection capability 1640 Provide fault-injection capability for disk IO.
2048 1641
2049 config FAIL_IO_TIMEOUT 1642 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1643 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1644 depends on FAULT_INJECTION && BLOCK
2052 help 1645 help
2053 Provide fault-injection capability 1646 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1647 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1648 thus exercising the error handling.
2056 1649
2057 Only works with drivers that use th 1650 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1651 for others it wont do anything.
2059 1652
2060 config FAIL_FUTEX 1653 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1654 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1655 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1656 depends on FAULT_INJECTION && FUTEX
2064 help 1657 help
2065 Provide fault-injection capability 1658 Provide fault-injection capability for futexes.
2066 1659
2067 config FAULT_INJECTION_DEBUG_FS 1660 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1661 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1662 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1663 help
2071 Enable configuration of fault-injec 1664 Enable configuration of fault-injection capabilities via debugfs.
2072 1665
2073 config FAIL_FUNCTION 1666 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1667 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1668 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1669 help
2077 Provide function-based fault-inject 1670 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1671 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1672 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1673 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1674 error handling in various subsystems.
2082 1675
2083 config FAIL_MMC_REQUEST 1676 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1677 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1678 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1679 help
2087 Provide fault-injection capability 1680 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1681 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1682 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1683 and to test how the mmc host driver handles retries from
2091 the block device. 1684 the block device.
2092 1685
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 1686 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1687 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1688 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1689 depends on !X86_64
2115 select STACKTRACE 1690 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P !! 1691 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
2117 help 1692 help
2118 Provide stacktrace filter for fault 1693 Provide stacktrace filter for fault-injection capabilities
2119 1694
2120 config ARCH_HAS_KCOV 1695 config ARCH_HAS_KCOV
2121 bool 1696 bool
2122 help 1697 help
2123 An architecture should select this 1698 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 1699 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 1700 disabling instrumentation for some early boot code.
2126 1701
2127 config CC_HAS_SANCOV_TRACE_PC 1702 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 1703 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 1704
2130 1705
2131 config KCOV 1706 config KCOV
2132 bool "Code coverage for fuzzing" 1707 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 1708 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 1709 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2135 depends on !ARCH_WANTS_NO_INSTR || HA <<
2136 GCC_VERSION >= 120000 || C <<
2137 select DEBUG_FS 1710 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 1711 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK <<
2140 help 1712 help
2141 KCOV exposes kernel code coverage i 1713 KCOV exposes kernel code coverage information in a form suitable
2142 for coverage-guided fuzzing (random 1714 for coverage-guided fuzzing (randomized testing).
2143 1715
>> 1716 If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> 1717 different machines and across reboots. If you need stable PC values,
>> 1718 disable RANDOMIZE_BASE.
>> 1719
2144 For more details, see Documentation 1720 For more details, see Documentation/dev-tools/kcov.rst.
2145 1721
2146 config KCOV_ENABLE_COMPARISONS 1722 config KCOV_ENABLE_COMPARISONS
2147 bool "Enable comparison operands coll 1723 bool "Enable comparison operands collection by KCOV"
2148 depends on KCOV 1724 depends on KCOV
2149 depends on $(cc-option,-fsanitize-cov 1725 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150 help 1726 help
2151 KCOV also exposes operands of every 1727 KCOV also exposes operands of every comparison in the instrumented
2152 code along with operand sizes and P 1728 code along with operand sizes and PCs of the comparison instructions.
2153 These operands can be used by fuzzi 1729 These operands can be used by fuzzing engines to improve the quality
2154 of fuzzing coverage. 1730 of fuzzing coverage.
2155 1731
2156 config KCOV_INSTRUMENT_ALL 1732 config KCOV_INSTRUMENT_ALL
2157 bool "Instrument all code by default" 1733 bool "Instrument all code by default"
2158 depends on KCOV 1734 depends on KCOV
2159 default y 1735 default y
2160 help 1736 help
2161 If you are doing generic system cal 1737 If you are doing generic system call fuzzing (like e.g. syzkaller),
2162 then you will want to instrument th 1738 then you will want to instrument the whole kernel and you should
2163 say y here. If you are doing more t 1739 say y here. If you are doing more targeted fuzzing (like e.g.
2164 filesystem fuzzing with AFL) then y 1740 filesystem fuzzing with AFL) then you will want to enable coverage
2165 for more specific subsets of files, 1741 for more specific subsets of files, and should say n here.
2166 1742
2167 config KCOV_IRQ_AREA_SIZE <<
2168 hex "Size of interrupt coverage colle <<
2169 depends on KCOV <<
2170 default 0x40000 <<
2171 help <<
2172 KCOV uses preallocated per-cpu area <<
2173 soft interrupts. This specifies the <<
2174 number of unsigned long words. <<
2175 <<
2176 menuconfig RUNTIME_TESTING_MENU 1743 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 1744 bool "Runtime Testing"
2178 default y !! 1745 def_bool y
2179 1746
2180 if RUNTIME_TESTING_MENU 1747 if RUNTIME_TESTING_MENU
2181 1748
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 1749 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 1750 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 1751 depends on DEBUG_FS
2220 help 1752 help
2221 This module enables testing of the di 1753 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 1754 inducing system failures at predefined crash points.
2223 If you don't need it: say N 1755 If you don't need it: say N
2224 Choose M here to compile this code as 1756 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 1757 called lkdtm.
2226 1758
2227 Documentation on how to use the modul 1759 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 1760 Documentation/fault-injection/provoke-crashes.rst
2229 1761
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 <<
2242 config TEST_LIST_SORT 1762 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 1763 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 1764 depends on DEBUG_KERNEL || m
2256 help 1765 help
2257 Enable this to turn on min heap fun !! 1766 Enable this to turn on 'list_sort()' function test. This test is
2258 executed only once during system bo 1767 executed only once during system boot (so affects only boot time),
2259 or at module load time. 1768 or at module load time.
2260 1769
2261 If unsure, say N. 1770 If unsure, say N.
2262 1771
2263 config TEST_SORT 1772 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 1773 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 1774 depends on DEBUG_KERNEL || m
2276 help 1775 help
2277 Enable this to turn on 'do_div()' f !! 1776 This option enables the self-test function of 'sort()' at boot,
2278 executed only once during system bo <<
2279 or at module load time. 1777 or at module load time.
2280 1778
2281 If unsure, say N. 1779 If unsure, say N.
2282 1780
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 1781 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 1782 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 1783 depends on DEBUG_KERNEL
2298 depends on KPROBES 1784 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 1785 help
2303 This option provides for testing ba 1786 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 1787 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 1788 verified for functionality.
2306 1789
2307 Say N if you are unsure. 1790 Say N if you are unsure.
2308 1791
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 1792 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 1793 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 1794 depends on DEBUG_KERNEL
2324 help 1795 help
2325 This option provides a kernel modul 1796 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 1797 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 1798 for distributions or general kernels, but only for kernel
2328 developers working on architecture 1799 developers working on architecture code.
2329 1800
2330 Note that if you want to also test 1801 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 1802 have to enable STACKTRACE as well.
2332 1803
2333 Say N if you are unsure. 1804 Say N if you are unsure.
2334 1805
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 1806 config RBTREE_TEST
2346 tristate "Red-Black tree test" 1807 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 1808 depends on DEBUG_KERNEL
2348 help 1809 help
2349 A benchmark measuring the performan 1810 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 1811 Also includes rbtree invariant checks.
2351 1812
2352 config REED_SOLOMON_TEST 1813 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 1814 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 1815 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 1816 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 1817 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 1818 select REED_SOLOMON_DEC16
2358 help 1819 help
2359 This option enables the self-test f 1820 This option enables the self-test function of rslib at boot,
2360 or at module load time. 1821 or at module load time.
2361 1822
2362 If unsure, say N. 1823 If unsure, say N.
2363 1824
2364 config INTERVAL_TREE_TEST 1825 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 1826 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 1827 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 1828 select INTERVAL_TREE
2368 help 1829 help
2369 A benchmark measuring the performan 1830 A benchmark measuring the performance of the interval tree library
2370 1831
2371 config PERCPU_TEST 1832 config PERCPU_TEST
2372 tristate "Per cpu operations test" 1833 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 1834 depends on m && DEBUG_KERNEL
2374 help 1835 help
2375 Enable this option to build test mo 1836 Enable this option to build test module which validates per-cpu
2376 operations. 1837 operations.
2377 1838
2378 If unsure, say N. 1839 If unsure, say N.
2379 1840
2380 config ATOMIC64_SELFTEST 1841 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 1842 tristate "Perform an atomic64_t self-test"
2382 help 1843 help
2383 Enable this option to test the atom 1844 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 1845 at module load time.
2385 1846
2386 If unsure, say N. 1847 If unsure, say N.
2387 1848
2388 config ASYNC_RAID6_TEST 1849 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 1850 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 1851 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 1852 select ASYNC_MEMCPY
2392 help !! 1853 ---help---
2393 This is a one-shot self test that p 1854 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 1855 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 1856 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 1857 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 1858 engine if one is available.
2398 1859
2399 If unsure, say N. 1860 If unsure, say N.
2400 1861
2401 config TEST_HEXDUMP 1862 config TEST_HEXDUMP
2402 tristate "Test functions located in t 1863 tristate "Test functions located in the hexdump module at runtime"
2403 1864
2404 config STRING_KUNIT_TEST !! 1865 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 1866 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 1867
2409 config STRING_HELPERS_KUNIT_TEST !! 1868 config TEST_STRSCPY
2410 tristate "KUnit test string helpers a !! 1869 tristate "Test strscpy*() family of functions at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 1870
2414 config TEST_KSTRTOX 1871 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 1872 tristate "Test kstrto*() family of functions at runtime"
2416 1873
2417 config TEST_PRINTF 1874 config TEST_PRINTF
2418 tristate "Test printf() family of fun 1875 tristate "Test printf() family of functions at runtime"
2419 1876
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 1877 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 1878 tristate "Test bitmap_*() family of functions at runtime"
2425 help 1879 help
2426 Enable this option to test the bitm 1880 Enable this option to test the bitmap functions at boot.
2427 1881
2428 If unsure, say N. 1882 If unsure, say N.
2429 1883
>> 1884 config TEST_BITFIELD
>> 1885 tristate "Test bitfield functions at runtime"
>> 1886 help
>> 1887 Enable this option to test the bitfield functions at boot.
>> 1888
>> 1889 If unsure, say N.
>> 1890
2430 config TEST_UUID 1891 config TEST_UUID
2431 tristate "Test functions located in t 1892 tristate "Test functions located in the uuid module at runtime"
2432 1893
2433 config TEST_XARRAY 1894 config TEST_XARRAY
2434 tristate "Test the XArray code at run 1895 tristate "Test the XArray code at runtime"
2435 1896
2436 config TEST_MAPLE_TREE !! 1897 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 1898 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 1899
2445 config TEST_RHASHTABLE 1900 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 1901 tristate "Perform selftest on resizable hash table"
2447 help 1902 help
2448 Enable this option to test the rhas 1903 Enable this option to test the rhashtable functions at boot.
2449 1904
2450 If unsure, say N. 1905 If unsure, say N.
2451 1906
>> 1907 config TEST_HASH
>> 1908 tristate "Perform selftest on hash functions"
>> 1909 help
>> 1910 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 1911 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 1912 hash functions on boot (or module load).
>> 1913
>> 1914 This is intended to help people writing architecture-specific
>> 1915 optimized versions. If unsure, say N.
>> 1916
2452 config TEST_IDA 1917 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 1918 tristate "Perform selftest on IDA functions"
2454 1919
2455 config TEST_PARMAN 1920 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 1921 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 1922 depends on PARMAN
2458 help 1923 help
2459 Enable this option to test priority 1924 Enable this option to test priority array manager on boot
2460 (or module load). 1925 (or module load).
2461 1926
2462 If unsure, say N. 1927 If unsure, say N.
2463 1928
2464 config TEST_IRQ_TIMINGS 1929 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 1930 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 1931 depends on IRQ_TIMINGS
2467 help 1932 help
2468 Enable this option to test the irq 1933 Enable this option to test the irq timings code on boot.
2469 1934
2470 If unsure, say N. 1935 If unsure, say N.
2471 1936
2472 config TEST_LKM 1937 config TEST_LKM
2473 tristate "Test module loading with 'h 1938 tristate "Test module loading with 'hello world' module"
2474 depends on m 1939 depends on m
2475 help 1940 help
2476 This builds the "test_module" modul 1941 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 1942 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 1943 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 1944 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 1945 and will not normally be loaded by the system unless explicitly
2481 requested by name. 1946 requested by name.
2482 1947
2483 If unsure, say N. 1948 If unsure, say N.
2484 1949
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 1950 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 1951 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 1952 default n
2500 depends on MMU 1953 depends on MMU
2501 depends on m 1954 depends on m
2502 help 1955 help
2503 This builds the "test_vmalloc" modu 1956 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 1957 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 1958 subsystem can be evaluated from performance and stability point
2506 of view. 1959 of view.
2507 1960
2508 If unsure, say N. 1961 If unsure, say N.
2509 1962
>> 1963 config TEST_USER_COPY
>> 1964 tristate "Test user/kernel boundary protections"
>> 1965 depends on m
>> 1966 help
>> 1967 This builds the "test_user_copy" module that runs sanity checks
>> 1968 on the copy_to/from_user infrastructure, making sure basic
>> 1969 user/kernel boundary testing is working. If it fails to load,
>> 1970 a regression has been detected in the user/kernel memory boundary
>> 1971 protections.
>> 1972
>> 1973 If unsure, say N.
>> 1974
2510 config TEST_BPF 1975 config TEST_BPF
2511 tristate "Test BPF filter functionali 1976 tristate "Test BPF filter functionality"
2512 depends on m && NET 1977 depends on m && NET
2513 help 1978 help
2514 This builds the "test_bpf" module t 1979 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 1980 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 1981 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 1982 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 1983 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 1984 verifier used by user space verifier testsuite.
2520 1985
2521 If unsure, say N. 1986 If unsure, say N.
2522 1987
2523 config TEST_BLACKHOLE_DEV 1988 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 1989 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 1990 depends on m && NET
2526 help 1991 help
2527 This builds the "test_blackhole_dev 1992 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 1993 data path through this blackhole netdev.
2529 1994
2530 If unsure, say N. 1995 If unsure, say N.
2531 1996
2532 config FIND_BIT_BENCHMARK 1997 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 1998 tristate "Test find_bit functions"
2534 help 1999 help
2535 This builds the "test_find_bit" mod 2000 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2001 functions performance.
2537 2002
2538 If unsure, say N. 2003 If unsure, say N.
2539 2004
2540 config TEST_FIRMWARE 2005 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2006 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2007 depends on FW_LOADER
2543 help 2008 help
2544 This builds the "test_firmware" mod 2009 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2010 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2011 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2012 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2013 userspace.
2549 2014
2550 If unsure, say N. 2015 If unsure, say N.
2551 2016
2552 config TEST_SYSCTL 2017 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2018 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2019 depends on PROC_SYSCTL
2555 help 2020 help
2556 This builds the "test_sysctl" modul 2021 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2022 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2023 production knobs which might alter system functionality.
2559 2024
2560 If unsure, say N. 2025 If unsure, say N.
2561 2026
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 2027 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! !! 2028 bool "KUnit test for sysctl"
2629 depends on KUNIT 2029 depends on KUNIT
2630 default KUNIT_ALL_TESTS <<
2631 help 2030 help
2632 This builds the proc sysctl unit te 2031 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2032 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2033 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2034 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2035
2637 If unsure, say N. 2036 If unsure, say N.
2638 2037
2639 config LIST_KUNIT_TEST 2038 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke !! 2039 bool "KUnit Test for Kernel Linked-list structures"
2641 depends on KUNIT 2040 depends on KUNIT
2642 default KUNIT_ALL_TESTS <<
2643 help 2041 help
2644 This builds the linked list KUnit t 2042 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2043 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2044 and associated macros.
2647 2045
2648 KUnit tests run during boot and out 2046 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything !! 2047 in TAP format (http://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2048 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2049 production build.
2652 2050
2653 For more information on KUnit and u 2051 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2052 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2053
2656 If unsure, say N. 2054 If unsure, say N.
2657 2055
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 2056 config TEST_UDELAY
2817 tristate "udelay test driver" 2057 tristate "udelay test driver"
2818 help 2058 help
2819 This builds the "udelay_test" modul 2059 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2060 that udelay() is working properly.
2821 2061
2822 If unsure, say N. 2062 If unsure, say N.
2823 2063
2824 config TEST_STATIC_KEYS 2064 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2065 tristate "Test static keys"
2826 depends on m 2066 depends on m
2827 help 2067 help
2828 Test the static key interfaces. 2068 Test the static key interfaces.
2829 2069
2830 If unsure, say N. 2070 If unsure, say N.
2831 2071
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 2072 config TEST_KMOD
2843 tristate "kmod stress tester" 2073 tristate "kmod stress tester"
2844 depends on m 2074 depends on m
2845 depends on NETDEVICES && NET_CORE && 2075 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2076 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 2077 select TEST_LKM
2849 select XFS_FS 2078 select XFS_FS
2850 select TUN 2079 select TUN
2851 select BTRFS_FS 2080 select BTRFS_FS
2852 help 2081 help
2853 Test the kernel's module loading me 2082 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2083 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2084 This test provides a series of tests against kmod.
2856 2085
2857 Although technically you can either 2086 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2087 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2088 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2089 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2090 module load requests, ultimately this could be fatal.
2862 2091
2863 To run tests run: 2092 To run tests run:
2864 2093
2865 tools/testing/selftests/kmod/kmod.s 2094 tools/testing/selftests/kmod/kmod.sh --help
2866 2095
2867 If unsure, say N. 2096 If unsure, say N.
2868 2097
2869 config TEST_DEBUG_VIRTUAL 2098 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2099 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2100 depends on DEBUG_VIRTUAL
2872 help 2101 help
2873 Test the kernel's ability to detect 2102 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2103 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2104 kernel's virtual address map.
2876 2105
2877 If unsure, say N. 2106 If unsure, say N.
2878 2107
2879 config TEST_MEMCAT_P 2108 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2109 tristate "Test memcat_p() helper function"
2881 help 2110 help
2882 Test the memcat_p() helper for corr 2111 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2112 pointer arrays together.
2884 2113
2885 If unsure, say N. 2114 If unsure, say N.
2886 2115
2887 config TEST_OBJAGG !! 2116 config TEST_LIVEPATCH
2888 tristate "Perform selftest on object !! 2117 tristate "Test livepatching"
2889 default n 2118 default n
2890 depends on OBJAGG !! 2119 depends on DYNAMIC_DEBUG
>> 2120 depends on LIVEPATCH
>> 2121 depends on m
2891 help 2122 help
2892 Enable this option to test object a !! 2123 Test kernel livepatching features for correctness. The tests will
2893 (or module load). !! 2124 load test modules that will be livepatched in various scenarios.
2894 2125
2895 config TEST_MEMINIT !! 2126 To run all the livepatching tests:
2896 tristate "Test heap/page initializati <<
2897 help <<
2898 Test if the kernel is zero-initiali <<
2899 This can be useful to test init_on_ <<
2900 2127
2901 If unsure, say N. !! 2128 make -C tools/testing/selftests TARGETS=livepatch run_tests
2902 2129
2903 config TEST_HMM !! 2130 Alternatively, individual tests may be invoked:
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 2131
2914 If unsure, say N. !! 2132 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2133 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2134 tools/testing/selftests/livepatch/test-shadow-vars.sh
2915 2135
2916 config TEST_FREE_PAGES !! 2136 If unsure, say N.
2917 tristate "Test freeing pages" <<
2918 help <<
2919 Test that a memory leak does not oc <<
2920 freeing a block of pages and a spec <<
2921 Loading this module is safe if your <<
2922 If the bug is not fixed, it will le <<
2923 probably OOM your system. <<
2924 2137
2925 config TEST_FPU !! 2138 config TEST_OBJAGG
2926 tristate "Test floating point operati !! 2139 tristate "Perform selftest on object aggreration manager"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2140 default n
>> 2141 depends on OBJAGG
2928 help 2142 help
2929 Enable this option to add /sys/kern !! 2143 Enable this option to test object aggregation manager on boot
2930 which will trigger a sequence of fl !! 2144 (or module load).
2931 for self-testing floating point con <<
2932 kernel_fpu_begin(). <<
2933 2145
2934 If unsure, say N. <<
2935 2146
2936 config TEST_CLOCKSOURCE_WATCHDOG !! 2147 config TEST_STACKINIT
2937 tristate "Test clocksource watchdog i !! 2148 tristate "Test level of stack variable initialization"
2938 depends on CLOCKSOURCE_WATCHDOG <<
2939 help 2149 help
2940 Enable this option to create a kern !! 2150 Test if the kernel is zero-initializing stack variables and
2941 a test of the clocksource watchdog. !! 2151 padding. Coverage is controlled by compiler flags,
2942 via modprobe or insmod in which cas !! 2152 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2943 loaded, or it may be built in, in w !! 2153 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2944 shortly after boot. <<
2945 2154
2946 If unsure, say N. 2155 If unsure, say N.
2947 2156
2948 config TEST_OBJPOOL !! 2157 config TEST_MEMINIT
2949 tristate "Test module for correctness !! 2158 tristate "Test heap/page initialization"
2950 default n <<
2951 depends on m && DEBUG_KERNEL <<
2952 help 2159 help
2953 This builds the "test_objpool" modu !! 2160 Test if the kernel is zero-initializing heap and page allocations.
2954 correctness verification and concur !! 2161 This can be useful to test init_on_alloc and init_on_free features.
2955 allocation and reclamation. <<
2956 2162
2957 If unsure, say N. 2163 If unsure, say N.
2958 2164
2959 endif # RUNTIME_TESTING_MENU 2165 endif # RUNTIME_TESTING_MENU
2960 2166
2961 config ARCH_USE_MEMTEST <<
2962 bool <<
2963 help <<
2964 An architecture should select this <<
2965 during boot process. <<
2966 <<
2967 config MEMTEST 2167 config MEMTEST
2968 bool "Memtest" 2168 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST !! 2169 ---help---
2970 help <<
2971 This option adds a kernel parameter 2170 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. !! 2171 to be set.
2973 memtest=0, mean disabled; -- 2172 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2173 memtest=1, mean do 1 test pattern;
2975 ... 2174 ...
2976 memtest=17, mean do 17 test p 2175 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2176 If you are unsure how to answer this question, answer N.
2978 2177
2979 2178
2980 2179
2981 config HYPERV_TESTING 2180 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2181 bool "Microsoft Hyper-V driver testing"
2983 default n 2182 default n
2984 depends on HYPERV && DEBUG_FS 2183 depends on HYPERV && DEBUG_FS
2985 help 2184 help
2986 Select this option to enable Hyper- 2185 Select this option to enable Hyper-V vmbus testing.
2987 2186
2988 endmenu # "Kernel Testing and Coverage" 2187 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 <<
3005 If unsure, say N. <<
3006 <<
3007 config RUST_OVERFLOW_CHECKS <<
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 <<
3018 Note that this will apply to all Ru <<
3019 <<
3020 If unsure, say Y. <<
3021 <<
3022 config RUST_BUILD_ASSERT_ALLOW <<
3023 bool "Allow unoptimized build-time as <<
3024 depends on RUST <<
3025 help <<
3026 Controls how are `build_error!` and <<
3027 <<
3028 If calls to them exist in the binar <<
3029 or that the optimizer failed to ver <<
3030 <<
3031 This should not happen, thus by def <<
3032 as an escape hatch, you can choose <<
3033 and let the check be carried at run <<
3034 the check fails). <<
3035 <<
3036 If unsure, say N. <<
3037 <<
3038 config RUST_KERNEL_DOCTESTS <<
3039 bool "Doctests for the `kernel` crate <<
3040 depends on RUST && KUNIT=y <<
3041 default KUNIT_ALL_TESTS <<
3042 help <<
3043 This builds the documentation tests <<
3044 as KUnit tests. <<
3045 <<
3046 For more information on KUnit and u <<
3047 please refer to the KUnit documenta <<
3048 <<
3049 If unsure, say N. <<
3050 <<
3051 endmenu # "Rust" <<
3052 2188
3053 endmenu # Kernel hacking 2189 endmenu # Kernel hacking
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