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 || PROC_FS)
113 select DYNAMIC_DEBUG_CORE 102 select DYNAMIC_DEBUG_CORE
114 help 103 help
115 104
116 Compiles debug level messages into t 105 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 106 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 107 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 108 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 110 enlarges the kernel text size by about 2%.
122 111
123 If a source file is compiled with DE 112 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 113 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 114 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 115 turned on by many CONFIG_*DEBUG* options.
127 116
128 Usage: 117 Usage:
129 118
130 Dynamic debugging is controlled via 119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' 120 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesyst 121 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature. 122 making use of this feature.
134 We refer the control file as: <debug 123 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 124 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 125 format for each line of the file is:
137 126
138 filename:lineno [module]functi 127 filename:lineno [module]function flags format
139 128
140 filename : source file of the debug 129 filename : source file of the debug statement
141 lineno : line number of the debug st 130 lineno : line number of the debug statement
142 module : module that contains the de 131 module : module that contains the debug statement
143 function : function that contains th 132 function : function that contains the debug statement
144 flags : '=p' means the line is turne 133 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb 134 format : the format used for the debug statement
146 135
147 From a live system: 136 From a live system:
148 137
149 nullarbor:~ # cat <debugfs>/dy 138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 139 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 143
155 Example usage: 144 Example usage:
156 145
157 // enable the message at line 146 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 148 <debugfs>/dynamic_debug/control
160 149
161 // enable all the messages in 150 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 151 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 152 <debugfs>/dynamic_debug/control
164 153
165 // enable all the messages in 154 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 155 nullarbor:~ # echo -n 'module nfsd +p' >
167 156 <debugfs>/dynamic_debug/control
168 157
169 // enable all 12 messages in t 158 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 159 nullarbor:~ # echo -n 'func svc_process +p' >
171 160 <debugfs>/dynamic_debug/control
172 161
173 // disable all 12 messages in 162 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 163 nullarbor:~ # echo -n 'func svc_process -p' >
175 164 <debugfs>/dynamic_debug/control
176 165
177 See Documentation/admin-guide/dynami 166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 167 information.
179 168
180 config DYNAMIC_DEBUG_CORE 169 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic 170 bool "Enable core function of dynamic debug support"
182 depends on PRINTK 171 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS) 172 depends on (DEBUG_FS || PROC_FS)
184 help 173 help
185 Enable core functional support of dy 174 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug t 175 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for eac 176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where th 177 the case of embedded system where the kernel image size is
189 sensitive for people. 178 sensitive for people.
190 179
191 config SYMBOLIC_ERRNAME 180 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in 181 bool "Support symbolic error names in printf"
193 default y if PRINTK 182 default y if PRINTK
194 help 183 help
195 If you say Y here, the kernel's prin 184 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error name 185 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kerne 186 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel 187 (about 3KB), but can make the kernel logs easier to read.
199 188
200 config DEBUG_BUGVERBOSE 189 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70 190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE 191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y 192 default y
204 help 193 help
205 Say Y here to make BUG() panics outp 194 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 195 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of 196 debugging but costs about 70-100K of memory.
208 197
209 endmenu # "printk and dmesg options" 198 endmenu # "printk and dmesg options"
210 199
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 200 menu "Compile-time checks and compiler options"
226 201
227 config DEBUG_INFO 202 config DEBUG_INFO
228 bool !! 203 bool "Compile the kernel with debug info"
229 help !! 204 depends on DEBUG_KERNEL && !COMPILE_TEST
230 A kernel debug info option other tha <<
231 in the "Debug information" choice be <<
232 information will be generated for bu <<
233 <<
234 # Clang generates .uleb128 with label differen <<
235 # older binutils ports do not support when uti <<
236 # relaxation: https://sourceware.org/bugzilla/ <<
237 config AS_HAS_NON_CONST_ULEB128 <<
238 def_bool $(as-instr,.uleb128 .Lexpr_en <<
239 <<
240 choice <<
241 prompt "Debug information" <<
242 depends on DEBUG_KERNEL <<
243 help 205 help
244 Selecting something other than "None !! 206 If you say Y here the resulting kernel image will include
245 that will include debugging info res !! 207 debugging info resulting in a larger kernel image.
246 This adds debug symbols to the kerne 208 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 209 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
>> 211 Say Y here only if you plan to debug the kernel.
249 212
250 Choose which version of DWARF debug !! 213 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" <<
302 214
303 if DEBUG_INFO 215 if DEBUG_INFO
304 216
305 config DEBUG_INFO_REDUCED 217 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 218 bool "Reduce debugging information"
307 help 219 help
308 If you say Y here gcc is instructed 220 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 221 information for structure types. This means that tools that
310 need full debugging information (lik 222 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 223 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 224 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 225 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 226 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 227 Only works with newer gcc versions.
316 228
317 choice !! 229 config DEBUG_INFO_COMPRESSED
318 prompt "Compressed Debug information" !! 230 bool "Compressed debugging 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) 231 depends on $(cc-option,-gz=zlib)
333 depends on $(ld-option,--compress-debu 232 depends on $(ld-option,--compress-debug-sections=zlib)
334 help 233 help
335 Compress the debug information using 234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
336 5.0+, binutils 2.26+, and zlib. 235 5.0+, binutils 2.26+, and zlib.
337 236
338 Users of dpkg-deb via scripts/packag 237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
339 size of their debug .deb packages wi 238 size of their debug .deb packages with this config set, due to the
340 debug info being compressed with zli 239 debug info being compressed with zlib, then the object files being
341 recompressed with a different compre 240 recompressed with a different compression scheme. But this is still
342 preferable to setting $KDEB_COMPRESS 241 preferable to setting $KDEB_COMPRESS to "none" which would be even
343 larger. 242 larger.
344 243
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 244 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 245 bool "Produce split debuginfo in .dwo files"
359 depends on $(cc-option,-gsplit-dwarf) 246 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 247 help
366 Generate debug info into separate .d 248 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 249 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 250 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 251 files instead of multiple times in object files and executables.
370 In addition the debug information is 252 In addition the debug information is also compressed.
371 253
372 Requires recent gcc (4.7+) and recen 254 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 255 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 256 to know about the .dwo files and include them.
375 Incompatible with older versions of 257 Incompatible with older versions of ccache.
376 258
>> 259 config DEBUG_INFO_DWARF4
>> 260 bool "Generate dwarf4 debuginfo"
>> 261 depends on $(cc-option,-gdwarf-4)
>> 262 help
>> 263 Generate dwarf4 debug info. This requires recent versions
>> 264 of gcc and gdb. It makes the debug information larger.
>> 265 But it significantly improves the success of resolving
>> 266 variables in gdb on optimized code.
>> 267
377 config DEBUG_INFO_BTF 268 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 269 bool "Generate BTF typeinfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG 270 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || C 271 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
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 272 help
386 Generate deduplicated BTF type infor 273 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 274 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 275 DWARF type info into equivalent deduplicated BTF type info.
389 276
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 277 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 278 bool "Provide GDB scripts for kernel debugging"
429 help 279 help
430 This creates the required links to G 280 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 281 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 282 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 283 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 284 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 285 for further details.
436 286
437 endif # DEBUG_INFO 287 endif # DEBUG_INFO
438 288
>> 289 config ENABLE_MUST_CHECK
>> 290 bool "Enable __must_check logic"
>> 291 default y
>> 292 help
>> 293 Enable the __must_check logic in the kernel build. Disable this to
>> 294 suppress the "warning: ignoring return value of 'foo', declared with
>> 295 attribute warn_unused_result" messages.
>> 296
439 config FRAME_WARN 297 config FRAME_WARN
440 int "Warn for stack frames larger than 298 int "Warn for stack frames larger than"
441 range 0 8192 299 range 0 8192
442 default 0 if KMSAN <<
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 300 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC 301 default 2048 if PARISC
445 default 1536 if (!64BIT && XTENSA) 302 default 1536 if (!64BIT && XTENSA)
446 default 1280 if KASAN && !64BIT 303 default 1280 if KASAN && !64BIT
447 default 1024 if !64BIT 304 default 1024 if !64BIT
448 default 2048 if 64BIT 305 default 2048 if 64BIT
449 help 306 help
450 Tell the compiler to warn at build t !! 307 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 308 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 309 Setting it to 0 disables the warning.
453 310
454 config STRIP_ASM_SYMS 311 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 312 bool "Strip assembler-generated symbols during link"
456 default n 313 default n
457 help 314 help
458 Strip internal assembler-generated s 315 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 316 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 317 get_wchan() and suchlike.
461 318
462 config READABLE_ASM 319 config READABLE_ASM
463 bool "Generate readable assembler code 320 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 321 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC <<
466 help 322 help
467 Disable some compiler optimizations 323 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 324 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 325 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 326 sane.
471 327
472 config HEADERS_INSTALL 328 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 329 bool "Install uapi headers to usr/include"
474 depends on !UML 330 depends on !UML
475 help 331 help
476 This option will install uapi header 332 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 333 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 334 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 335 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 336 as uapi header sanity checks.
481 337
482 config DEBUG_SECTION_MISMATCH 338 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 339 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 340 help
486 The section mismatch analysis checks 341 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 342 references from one section to another section.
488 During linktime or runtime, some sec 343 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 344 any use of code/data previously in these sections would
490 most likely result in an oops. 345 most likely result in an oops.
491 In the code, functions and variables 346 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 347 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 348 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 349 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 350 kernel build, and enabling this option causes the following
496 additional step to occur: 351 additional step to occur:
497 - Add the option -fno-inline-functio 352 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 353 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 354 function, we would lose the section information and thus
500 the analysis would not catch the i 355 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 356 This option tells gcc to inline less (but it does result in
502 a larger kernel). 357 a larger kernel).
503 358
504 config SECTION_MISMATCH_WARN_ONLY 359 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 360 bool "Make section mismatch errors non-fatal"
506 default y 361 default y
507 help 362 help
508 If you say N here, the build process 363 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 364 section mismatch, instead of just throwing warnings.
510 365
511 If unsure, say Y. 366 If unsure, say Y.
512 367
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B !! 368 config DEBUG_FORCE_FUNCTION_ALIGN_32B
514 bool "Force all function address 64B a !! 369 bool "Force all function address 32B aligned" if EXPERT
515 depends on EXPERT && (X86_64 || ARM64 <<
516 select FUNCTION_ALIGNMENT_64B <<
517 help 370 help
518 There are cases that a commit from o 371 There are cases that a commit from one domain changes the function
519 address alignment of other domains, 372 address alignment of other domains, and cause magic performance
520 bump (regression or improvement). En 373 bump (regression or improvement). Enable this option will help to
521 verify if the bump is caused by func 374 verify if the bump is caused by function alignment changes, while
522 it will slightly increase the kernel 375 it will slightly increase the kernel size and affect icache usage.
523 376
524 It is mainly for debug and performan 377 It is mainly for debug and performance tuning use.
525 378
526 # 379 #
527 # Select this config option from the architect 380 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 381 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 382 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 383 #
531 config ARCH_WANT_FRAME_POINTERS 384 config ARCH_WANT_FRAME_POINTERS
532 bool 385 bool
533 386
534 config FRAME_POINTER 387 config FRAME_POINTER
535 bool "Compile the kernel with frame po 388 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 389 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 390 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 391 help
539 If you say Y here the resulting kern 392 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 393 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 394 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 395
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 396 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 397 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 398 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 399 default n
551 help 400 help
552 Validate frame pointer rules at comp !! 401 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 402 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 403 that runtime stack traces are more reliable.
>> 404
>> 405 This is also a prerequisite for generation of ORC unwind data, which
>> 406 is needed for CONFIG_UNWINDER_ORC.
554 407
555 For more information, see 408 For more information, see
556 tools/objtool/Documentation/objtool. !! 409 tools/objtool/Documentation/stack-validation.txt.
557 410
558 config NOINSTR_VALIDATION !! 411 config VMLINUX_VALIDATION
559 bool 412 bool
560 depends on HAVE_NOINSTR_VALIDATION && !! 413 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
561 select OBJTOOL <<
562 default y 414 default y
563 415
564 config VMLINUX_MAP <<
565 bool "Generate vmlinux.map file when l <<
566 depends on EXPERT <<
567 help <<
568 Selecting this option will pass "-Ma <<
569 when linking vmlinux. That file can <<
570 and debugging magic section games, a <<
571 pieces of code get eliminated with <<
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION <<
573 <<
574 config DEBUG_FORCE_WEAK_PER_CPU 416 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 417 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 418 depends on DEBUG_KERNEL
577 help 419 help
578 s390 and alpha require percpu variab 420 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 421 defined weak to work around addressing range issue which
580 puts the following two restrictions 422 puts the following two restrictions on percpu variable
581 definitions. 423 definitions.
582 424
583 1. percpu symbols must be unique whe 425 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 426 2. percpu variables can't be defined inside a function
585 427
586 To ensure that generic code follows 428 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 429 option forces all percpu variables to be defined as weak.
588 430
589 endmenu # "Compiler options" 431 endmenu # "Compiler options"
590 432
591 menu "Generic Kernel Debugging Instruments" 433 menu "Generic Kernel Debugging Instruments"
592 434
593 config MAGIC_SYSRQ 435 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 436 bool "Magic SysRq key"
595 depends on !UML 437 depends on !UML
596 help 438 help
597 If you say Y here, you will have som 439 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 440 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 441 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 442 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 443 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 444 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 445 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 446 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 447 Don't say Y unless you really know what this hack does.
606 448
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 449 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 450 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 451 depends on MAGIC_SYSRQ
610 default 0x1 452 default 0x1
611 help 453 help
612 Specifies which SysRq key functions 454 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 455 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 456 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 457
616 config MAGIC_SYSRQ_SERIAL 458 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 459 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 460 depends on MAGIC_SYSRQ
619 default y 461 default y
620 help 462 help
621 Many embedded boards have a disconne 463 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 464 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 465 This option allows you to decide whether you want to enable the
624 magic SysRq key. 466 magic SysRq key.
625 467
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE 468 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627 string "Char sequence that enables mag 469 string "Char sequence that enables magic SysRq over serial"
628 depends on MAGIC_SYSRQ_SERIAL 470 depends on MAGIC_SYSRQ_SERIAL
629 default "" 471 default ""
630 help 472 help
631 Specifies a sequence of characters t 473 Specifies a sequence of characters that can follow BREAK to enable
632 SysRq on a serial console. 474 SysRq on a serial console.
633 475
634 If unsure, leave an empty string and 476 If unsure, leave an empty string and the option will not be enabled.
635 477
636 config DEBUG_FS 478 config DEBUG_FS
637 bool "Debug Filesystem" 479 bool "Debug Filesystem"
638 help 480 help
639 debugfs is a virtual file system tha 481 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 482 debugging files into. Enable this option to be able to read and
641 write to these files. 483 write to these files.
642 484
643 For detailed documentation on the de 485 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 486 Documentation/filesystems/.
645 487
646 If unsure, say N. 488 If unsure, say N.
647 489
648 choice 490 choice
649 prompt "Debugfs default access" 491 prompt "Debugfs default access"
650 depends on DEBUG_FS 492 depends on DEBUG_FS
651 default DEBUG_FS_ALLOW_ALL 493 default DEBUG_FS_ALLOW_ALL
652 help 494 help
653 This selects the default access rest 495 This selects the default access restrictions for debugfs.
654 It can be overridden with kernel com 496 It can be overridden with kernel command line option
655 debugfs=[on,no-mount,off]. The restr 497 debugfs=[on,no-mount,off]. The restrictions apply for API access
656 and filesystem registration. 498 and filesystem registration.
657 499
658 config DEBUG_FS_ALLOW_ALL 500 config DEBUG_FS_ALLOW_ALL
659 bool "Access normal" 501 bool "Access normal"
660 help 502 help
661 No restrictions apply. Both API and 503 No restrictions apply. Both API and filesystem registration
662 is on. This is the normal default op 504 is on. This is the normal default operation.
663 505
664 config DEBUG_FS_DISALLOW_MOUNT 506 config DEBUG_FS_DISALLOW_MOUNT
665 bool "Do not register debugfs as files 507 bool "Do not register debugfs as filesystem"
666 help 508 help
667 The API is open but filesystem is no 509 The API is open but filesystem is not loaded. Clients can still do
668 their work and read with debug tools 510 their work and read with debug tools that do not need
669 debugfs filesystem. 511 debugfs filesystem.
670 512
671 config DEBUG_FS_ALLOW_NONE 513 config DEBUG_FS_ALLOW_NONE
672 bool "No access" 514 bool "No access"
673 help 515 help
674 Access is off. Clients get -PERM whe 516 Access is off. Clients get -PERM when trying to create nodes in
675 debugfs tree and debugfs is not regi 517 debugfs tree and debugfs is not registered as a filesystem.
676 Client can then back-off or continue 518 Client can then back-off or continue without debugfs access.
677 519
678 endchoice 520 endchoice
679 521
680 source "lib/Kconfig.kgdb" 522 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan" 523 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" 524 source "lib/Kconfig.kcsan"
683 525
684 endmenu 526 endmenu
685 527
686 menu "Networking Debugging" !! 528 config DEBUG_KERNEL
>> 529 bool "Kernel debugging"
>> 530 help
>> 531 Say Y here if you are developing drivers or trying to debug and
>> 532 identify kernel problems.
687 533
688 source "net/Kconfig.debug" !! 534 config DEBUG_MISC
>> 535 bool "Miscellaneous debug code"
>> 536 default DEBUG_KERNEL
>> 537 depends on DEBUG_KERNEL
>> 538 help
>> 539 Say Y here if you need to enable miscellaneous debug code that should
>> 540 be under a more specific debug option but isn't.
689 541
690 endmenu # "Networking Debugging" <<
691 542
692 menu "Memory Debugging" 543 menu "Memory Debugging"
693 544
694 source "mm/Kconfig.debug" 545 source "mm/Kconfig.debug"
695 546
696 config DEBUG_OBJECTS 547 config DEBUG_OBJECTS
697 bool "Debug object operations" 548 bool "Debug object operations"
698 depends on DEBUG_KERNEL 549 depends on DEBUG_KERNEL
699 help 550 help
700 If you say Y here, additional code w 551 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 552 kernel to track the life time of various objects and validate
702 the operations on those objects. 553 the operations on those objects.
703 554
704 config DEBUG_OBJECTS_SELFTEST 555 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 556 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 557 depends on DEBUG_OBJECTS
707 help 558 help
708 This enables the selftest of the obj 559 This enables the selftest of the object debug code.
709 560
710 config DEBUG_OBJECTS_FREE 561 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 562 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 563 depends on DEBUG_OBJECTS
713 help 564 help
714 This enables checks whether a k/v fr 565 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 566 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 567 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 568 much slower.
718 569
719 config DEBUG_OBJECTS_TIMERS 570 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 571 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 572 depends on DEBUG_OBJECTS
722 help 573 help
723 If you say Y here, additional code w 574 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 575 timer routines to track the life time of timer objects and
725 validate the timer operations. 576 validate the timer operations.
726 577
727 config DEBUG_OBJECTS_WORK 578 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 579 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 580 depends on DEBUG_OBJECTS
730 help 581 help
731 If you say Y here, additional code w 582 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 583 work queue routines to track the life time of work objects and
733 validate the work operations. 584 validate the work operations.
734 585
735 config DEBUG_OBJECTS_RCU_HEAD 586 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 587 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 588 depends on DEBUG_OBJECTS
738 help 589 help
739 Enable this to turn on debugging of 590 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 591
741 config DEBUG_OBJECTS_PERCPU_COUNTER 592 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 593 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 594 depends on DEBUG_OBJECTS
744 help 595 help
745 If you say Y here, additional code w 596 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 597 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 598 objects and validate the percpu counter operations.
748 599
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 600 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 601 int "debug_objects bootup default value (0-1)"
751 range 0 1 602 range 0 1
752 default "1" 603 default "1"
753 depends on DEBUG_OBJECTS 604 depends on DEBUG_OBJECTS
754 help 605 help
755 Debug objects boot parameter default 606 Debug objects boot parameter default value
756 607
757 config SHRINKER_DEBUG !! 608 config DEBUG_SLAB
758 bool "Enable shrinker debugging suppor !! 609 bool "Debug slab memory allocations"
759 depends on DEBUG_FS !! 610 depends on DEBUG_KERNEL && SLAB
>> 611 help
>> 612 Say Y here to have the kernel do limited verification on memory
>> 613 allocation as well as poisoning memory on free to catch use of freed
>> 614 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 615
>> 616 config SLUB_DEBUG_ON
>> 617 bool "SLUB debugging on by default"
>> 618 depends on SLUB && SLUB_DEBUG
>> 619 default n
>> 620 help
>> 621 Boot with debugging on by default. SLUB boots by default with
>> 622 the runtime debug capabilities switched off. Enabling this is
>> 623 equivalent to specifying the "slub_debug" parameter on boot.
>> 624 There is no support for more fine grained debug control like
>> 625 possible with slub_debug=xxx. SLUB debugging may be switched
>> 626 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 627 "slub_debug=-".
>> 628
>> 629 config SLUB_STATS
>> 630 default n
>> 631 bool "Enable SLUB performance statistics"
>> 632 depends on SLUB && SYSFS
>> 633 help
>> 634 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 635 order find ways to optimize the allocator. This should never be
>> 636 enabled for production use since keeping statistics slows down
>> 637 the allocator by a few percentage points. The slabinfo command
>> 638 supports the determination of the most active slabs to figure
>> 639 out which slabs are relevant to a particular load.
>> 640 Try running: slabinfo -DA
>> 641
>> 642 config HAVE_DEBUG_KMEMLEAK
>> 643 bool
>> 644
>> 645 config DEBUG_KMEMLEAK
>> 646 bool "Kernel memory leak detector"
>> 647 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 648 select DEBUG_FS
>> 649 select STACKTRACE if STACKTRACE_SUPPORT
>> 650 select KALLSYMS
>> 651 select CRC32
>> 652 help
>> 653 Say Y here if you want to enable the memory leak
>> 654 detector. The memory allocation/freeing is traced in a way
>> 655 similar to the Boehm's conservative garbage collector, the
>> 656 difference being that the orphan objects are not freed but
>> 657 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 658 feature will introduce an overhead to memory
>> 659 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 660 details.
>> 661
>> 662 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
>> 663 of finding leaks due to the slab objects poisoning.
>> 664
>> 665 In order to access the kmemleak file, debugfs needs to be
>> 666 mounted (usually at /sys/kernel/debug).
>> 667
>> 668 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
>> 669 int "Kmemleak memory pool size"
>> 670 depends on DEBUG_KMEMLEAK
>> 671 range 200 1000000
>> 672 default 16000
760 help 673 help
761 Say Y to enable the shrinker debugfs !! 674 Kmemleak must track all the memory allocations to avoid
762 visibility into the kernel memory sh !! 675 reporting false positives. Since memory may be allocated or
763 Disable it to avoid an extra memory !! 676 freed before kmemleak is fully initialised, use a static pool
>> 677 of metadata objects to track such callbacks. After kmemleak is
>> 678 fully initialised, this memory pool acts as an emergency one
>> 679 if slab allocations fail.
>> 680
>> 681 config DEBUG_KMEMLEAK_TEST
>> 682 tristate "Simple test for the kernel memory leak detector"
>> 683 depends on DEBUG_KMEMLEAK && m
>> 684 help
>> 685 This option enables a module that explicitly leaks memory.
>> 686
>> 687 If unsure, say N.
>> 688
>> 689 config DEBUG_KMEMLEAK_DEFAULT_OFF
>> 690 bool "Default kmemleak to off"
>> 691 depends on DEBUG_KMEMLEAK
>> 692 help
>> 693 Say Y here to disable kmemleak by default. It can then be enabled
>> 694 on the command line via kmemleak=on.
>> 695
>> 696 config DEBUG_KMEMLEAK_AUTO_SCAN
>> 697 bool "Enable kmemleak auto scan thread on boot up"
>> 698 default y
>> 699 depends on DEBUG_KMEMLEAK
>> 700 help
>> 701 Depending on the cpu, kmemleak scan may be cpu intensive and can
>> 702 stall user tasks at times. This option enables/disables automatic
>> 703 kmemleak scan at boot up.
>> 704
>> 705 Say N here to disable kmemleak auto scan thread to stop automatic
>> 706 scanning. Disabling this option disables automatic reporting of
>> 707 memory leaks.
>> 708
>> 709 If unsure, say Y.
764 710
765 config DEBUG_STACK_USAGE 711 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 712 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 713 depends on DEBUG_KERNEL && !IA64
768 help 714 help
769 Enables the display of the minimum a 715 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 716 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 <<
773 717
774 This option will slow down process c 718 This option will slow down process creation somewhat.
775 719
776 config SCHED_STACK_END_CHECK 720 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 721 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 722 depends on DEBUG_KERNEL
779 default n 723 default n
780 help 724 help
781 This option checks for a stack overr 725 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 726 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 727 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 728 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 729 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 730 is examined. The runtime overhead introduced is minimal.
787 731
788 config ARCH_HAS_DEBUG_VM_PGTABLE 732 config ARCH_HAS_DEBUG_VM_PGTABLE
789 bool 733 bool
790 help 734 help
791 An architecture should select this w 735 An architecture should select this when it can successfully
792 build and run DEBUG_VM_PGTABLE. 736 build and run DEBUG_VM_PGTABLE.
793 737
794 config DEBUG_VM_IRQSOFF <<
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 <<
797 config DEBUG_VM 738 config DEBUG_VM
798 bool "Debug VM" 739 bool "Debug VM"
799 depends on DEBUG_KERNEL 740 depends on DEBUG_KERNEL
800 help 741 help
801 Enable this to turn on extended chec 742 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 743 that may impact performance.
803 744
804 If unsure, say N. 745 If unsure, say N.
805 746
806 config DEBUG_VM_SHOOT_LAZIES !! 747 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 748 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 749 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE <<
820 help 750 help
821 Enable VM maple tree debugging infor !! 751 Enable this to turn on VMA caching debug information. Doing so
>> 752 can cause significant overhead, so only enable it in non-production
>> 753 environments.
822 754
823 If unsure, say N. 755 If unsure, say N.
824 756
825 config DEBUG_VM_RB 757 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 758 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 759 depends on DEBUG_VM
828 help 760 help
829 Enable VM red-black tree debugging i 761 Enable VM red-black tree debugging information and extra validations.
830 762
831 If unsure, say N. 763 If unsure, say N.
832 764
833 config DEBUG_VM_PGFLAGS 765 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 766 bool "Debug page-flags operations"
835 depends on DEBUG_VM 767 depends on DEBUG_VM
836 help 768 help
837 Enables extra validation on page fla 769 Enables extra validation on page flags operations.
838 770
839 If unsure, say N. 771 If unsure, say N.
840 772
841 config DEBUG_VM_PGTABLE 773 config DEBUG_VM_PGTABLE
842 bool "Debug arch page table for semant 774 bool "Debug arch page table for semantics compliance"
843 depends on MMU 775 depends on MMU
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE 776 depends on ARCH_HAS_DEBUG_VM_PGTABLE
845 default y if DEBUG_VM 777 default y if DEBUG_VM
846 help 778 help
847 This option provides a debug method 779 This option provides a debug method which can be used to test
848 architecture page table helper funct 780 architecture page table helper functions on various platforms in
849 verifying if they comply with expect 781 verifying if they comply with expected generic MM semantics. This
850 will help architecture code in makin 782 will help architecture code in making sure that any changes or
851 new additions of these helpers still 783 new additions of these helpers still conform to expected
852 semantics of the generic MM. Platfor 784 semantics of the generic MM. Platforms will have to opt in for
853 this through ARCH_HAS_DEBUG_VM_PGTAB 785 this through ARCH_HAS_DEBUG_VM_PGTABLE.
854 786
855 If unsure, say N. 787 If unsure, say N.
856 788
857 config ARCH_HAS_DEBUG_VIRTUAL 789 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 790 bool
859 791
860 config DEBUG_VIRTUAL 792 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 793 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 794 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 795 help
864 Enable some costly sanity checks in 796 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 797 catch mistakes with virt_to_page() and friends.
866 798
867 If unsure, say N. 799 If unsure, say N.
868 800
869 config DEBUG_NOMMU_REGIONS 801 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 802 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 803 depends on DEBUG_KERNEL && !MMU
872 help 804 help
873 This option causes the global tree o 805 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 806 regions to be regularly checked for invalid topology.
875 807
876 config DEBUG_MEMORY_INIT 808 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 809 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 810 default !EXPERT
879 help 811 help
880 Enable this for additional checks du 812 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 813 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 814 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 815 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 816 on the mminit_loglevel= command-line option.
885 817
886 If unsure, say Y 818 If unsure, say Y
887 819
888 config MEMORY_NOTIFIER_ERROR_INJECT 820 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 821 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 822 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 823 help
892 This option provides the ability to 824 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 825 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 826 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 827
896 If the notifier call chain should be 828 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 829 notified, write the error code to "actions/<notifier event>/error".
898 830
899 Example: Inject memory hotplug offli 831 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 832
901 # cd /sys/kernel/debug/notifier-erro 833 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 834 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 835 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 836 bash: echo: write error: Cannot allocate memory
905 837
906 To compile this code as a module, ch 838 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 839 be called memory-notifier-error-inject.
908 840
909 If unsure, say N. 841 If unsure, say N.
910 842
911 config DEBUG_PER_CPU_MAPS 843 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 844 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 845 depends on DEBUG_KERNEL
914 depends on SMP 846 depends on SMP
915 help 847 help
916 Say Y to verify that the per_cpu map 848 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 849 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 850 and decreases performance.
919 851
920 Say N if unsure. 852 Say N if unsure.
921 853
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 854 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 855 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 856 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A <<
946 select DEBUG_KMAP_LOCAL <<
947 help 857 help
948 This option enables additional error 858 This option enables additional error checking for high memory
949 systems. Disable for production sys 859 systems. Disable for production systems.
950 860
951 config HAVE_DEBUG_STACKOVERFLOW 861 config HAVE_DEBUG_STACKOVERFLOW
952 bool 862 bool
953 863
954 config DEBUG_STACKOVERFLOW 864 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 865 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 866 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help 867 help
958 Say Y here if you want to check for 868 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 869 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 870 option will show detailed messages if free stack space drops
961 below a certain limit. 871 below a certain limit.
962 872
963 These kinds of bugs usually occur wh 873 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 874 kernel get too deep, especially when interrupts are
965 involved. 875 involved.
966 876
967 Use this in cases where you see appa 877 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 878 corruption, especially if it appears in 'struct thread_info'
969 879
970 If in doubt, say "N". 880 If in doubt, say "N".
971 881
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" 882 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" <<
1005 source "lib/Kconfig.kmsan" <<
1006 883
1007 endmenu # "Memory Debugging" 884 endmenu # "Memory Debugging"
1008 885
1009 config DEBUG_SHIRQ 886 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 887 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 888 depends on DEBUG_KERNEL
1012 help 889 help
1013 Enable this to generate a spurious 890 Enable this to generate a spurious interrupt just before a shared
1014 interrupt handler is deregistered ( 891 interrupt handler is deregistered (generating one when registering
1015 is currently disabled). Drivers nee 892 is currently disabled). Drivers need to handle this correctly. Some
1016 don't and need to be caught. 893 don't and need to be caught.
1017 894
1018 menu "Debug Oops, Lockups and Hangs" 895 menu "Debug Oops, Lockups and Hangs"
1019 896
1020 config PANIC_ON_OOPS 897 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 898 bool "Panic on Oops"
1022 help 899 help
1023 Say Y here to enable the kernel to 900 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 901 has the same effect as setting oops=panic on the kernel command
1025 line. 902 line.
1026 903
1027 This feature is useful to ensure th 904 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 905 anything erroneous after an oops which could result in data
1029 corruption or other issues. 906 corruption or other issues.
1030 907
1031 Say N if unsure. 908 Say N if unsure.
1032 909
1033 config PANIC_ON_OOPS_VALUE 910 config PANIC_ON_OOPS_VALUE
1034 int 911 int
1035 range 0 1 912 range 0 1
1036 default 0 if !PANIC_ON_OOPS 913 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 914 default 1 if PANIC_ON_OOPS
1038 915
1039 config PANIC_TIMEOUT 916 config PANIC_TIMEOUT
1040 int "panic timeout" 917 int "panic timeout"
1041 default 0 918 default 0
1042 help 919 help
1043 Set the timeout value (in seconds) 920 Set the timeout value (in seconds) until a reboot occurs when
1044 the kernel panics. If n = 0, then w 921 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 922 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 923 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 924
1050 config LOCKUP_DETECTOR 925 config LOCKUP_DETECTOR
1051 bool 926 bool
1052 927
1053 config SOFTLOCKUP_DETECTOR 928 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 929 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 930 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 931 select LOCKUP_DETECTOR
1057 help 932 help
1058 Say Y here to enable the kernel to 933 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 934 soft lockups.
1060 935
1061 Softlockups are bugs that cause the 936 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 937 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 938 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 939 detection and the system will stay locked up.
1065 940
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 941 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 942 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 943 depends on SOFTLOCKUP_DETECTOR
1083 help 944 help
1084 Say Y here to enable the kernel to 945 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 946 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 947 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 948 sysctl), without giving other tasks a chance to run.
1088 949
1089 The panic can be used in combinatio 950 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 951 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 952 lockup has been detected. This feature is useful for
1092 high-availability systems that have 953 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 954 where a lockup must be resolved ASAP.
1094 955
1095 Say N if unsure. 956 Say N if unsure.
1096 957
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 958 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 959 int
>> 960 depends on SOFTLOCKUP_DETECTOR
>> 961 range 0 1
>> 962 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 963 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 964
>> 965 config HARDLOCKUP_DETECTOR_PERF
1098 bool 966 bool
1099 depends on SMP !! 967 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 968
1102 # 969 #
1103 # Global switch whether to build a hardlockup !! 970 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 971 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 972 #
1107 # s390: it reported many false positive !! 973 config HARDLOCKUP_CHECK_TIMESTAMP
>> 974 bool
>> 975
1108 # 976 #
1109 # sparc64: has a custom implementation !! 977 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 978 # lockup detector rather than the perf based detector.
1111 # 979 #
1112 config HARDLOCKUP_DETECTOR 980 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 981 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 982 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 983 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 984 select LOCKUP_DETECTOR
1120 !! 985 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1121 help 986 help
1122 Say Y here to enable the kernel to 987 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 988 hard lockups.
1124 989
1125 Hardlockups are bugs that cause the 990 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 991 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 992 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 993 and the system will stay locked up.
1129 994
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 995 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 996 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 997 depends on HARDLOCKUP_DETECTOR
1190 help 998 help
1191 Say Y here to enable the kernel to 999 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 1000 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 1001 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 1002 using the watchdog_thresh sysctl).
1195 1003
1196 Say N if unsure. 1004 Say N if unsure.
1197 1005
>> 1006 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 1007 int
>> 1008 depends on HARDLOCKUP_DETECTOR
>> 1009 range 0 1
>> 1010 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 1011 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 1012
1198 config DETECT_HUNG_TASK 1013 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 1014 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 1015 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 1016 default SOFTLOCKUP_DETECTOR
1202 help 1017 help
1203 Say Y here to enable the kernel to 1018 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 1019 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 1020 uninterruptible "D" state indefinitely.
1206 1021
1207 When a hung task is detected, the k 1022 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 1023 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 1024 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 1025 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 1026 feature has negligible overhead.
1212 1027
1213 config DEFAULT_HUNG_TASK_TIMEOUT 1028 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 1029 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 1030 depends on DETECT_HUNG_TASK
1216 default 120 1031 default 120
1217 help 1032 help
1218 This option controls the default ti 1033 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 1034 to determine when a task has become non-responsive and should
1220 be considered hung. 1035 be considered hung.
1221 1036
1222 It can be adjusted at runtime via t 1037 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 1038 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 1039 /proc/sys/kernel/hung_task_timeout_secs.
1225 1040
1226 A timeout of 0 disables the check. 1041 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 1042 Keeping the default should be fine in most cases.
1228 1043
1229 config BOOTPARAM_HUNG_TASK_PANIC 1044 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 1045 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 1046 depends on DETECT_HUNG_TASK
1232 help 1047 help
1233 Say Y here to enable the kernel to 1048 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 1049 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 1050 in uninterruptible "D" state.
1236 1051
1237 The panic can be used in combinatio 1052 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 1053 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 1054 hung task has been detected. This feature is useful for
1240 high-availability systems that have 1055 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 1056 where a hung tasks must be resolved ASAP.
1242 1057
1243 Say N if unsure. 1058 Say N if unsure.
1244 1059
>> 1060 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 1061 int
>> 1062 depends on DETECT_HUNG_TASK
>> 1063 range 0 1
>> 1064 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 1065 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 1066
1245 config WQ_WATCHDOG 1067 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 1068 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 1069 depends on DEBUG_KERNEL
1248 help 1070 help
1249 Say Y here to enable stall detectio 1071 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 1072 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 1073 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 1074 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 1075 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 1076 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 1077
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 1078 config TEST_LOCKUP
1270 tristate "Test module to generate loc 1079 tristate "Test module to generate lockups"
1271 depends on m 1080 depends on m
1272 help 1081 help
1273 This builds the "test_lockup" modul 1082 This builds the "test_lockup" module that helps to make sure
1274 that watchdogs and lockup detectors 1083 that watchdogs and lockup detectors are working properly.
1275 1084
1276 Depending on module parameters it c 1085 Depending on module parameters it could emulate soft or hard
1277 lockup, "hung task", or locking arb 1086 lockup, "hung task", or locking arbitrary lock for a long time.
1278 Also it could generate series of lo 1087 Also it could generate series of lockups with cooling-down periods.
1279 1088
1280 If unsure, say N. 1089 If unsure, say N.
1281 1090
1282 endmenu # "Debug lockups and hangs" 1091 endmenu # "Debug lockups and hangs"
1283 1092
1284 menu "Scheduler Debugging" 1093 menu "Scheduler Debugging"
1285 1094
1286 config SCHED_DEBUG 1095 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 1096 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 1097 depends on DEBUG_KERNEL && PROC_FS
1289 default y 1098 default y
1290 help 1099 help
1291 If you say Y here, the /sys/kernel/ !! 1100 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 1101 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 1102 option is minimal.
1294 1103
1295 config SCHED_INFO 1104 config SCHED_INFO
1296 bool 1105 bool
1297 default n 1106 default n
1298 1107
1299 config SCHEDSTATS 1108 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1109 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1110 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1111 select SCHED_INFO
1303 help 1112 help
1304 If you say Y here, additional code 1113 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1114 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1115 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1116 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1117 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1118 application, you can say N to avoid the very slight overhead
1310 this adds. 1119 this adds.
1311 1120
1312 endmenu 1121 endmenu
1313 1122
1314 config DEBUG_TIMEKEEPING 1123 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1124 bool "Enable extra timekeeping sanity checking"
1316 help 1125 help
1317 This option will enable additional 1126 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1127 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1128 problems are suspected.
1320 1129
1321 This may include checks in the time 1130 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1131 option may have a (very small) performance impact to some
1323 workloads. 1132 workloads.
1324 1133
1325 If unsure, say N. 1134 If unsure, say N.
1326 1135
1327 config DEBUG_PREEMPT 1136 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1137 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION 1138 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1330 help 1139 help
1331 If you say Y here then the kernel w 1140 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1141 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1142 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1143 will detect preemption count underflows.
1335 1144
1336 This option has potential to introd 1145 This option has potential to introduce high runtime overhead,
1337 depending on workload as it trigger 1146 depending on workload as it triggers debugging routines for each
1338 this_cpu operation. It should only 1147 this_cpu operation. It should only be used for debugging purposes.
1339 1148
1340 menu "Lock Debugging (spinlocks, mutexes, etc 1149 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1150
1342 config LOCK_DEBUGGING_SUPPORT 1151 config LOCK_DEBUGGING_SUPPORT
1343 bool 1152 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1153 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1154 default y
1346 1155
1347 config PROVE_LOCKING 1156 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1157 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1158 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1159 select LOCKDEP
1351 select DEBUG_SPINLOCK 1160 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1161 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1162 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1163 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1164 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1165 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE 1166 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358 select TRACE_IRQFLAGS 1167 select TRACE_IRQFLAGS
1359 default n 1168 default n
1360 help 1169 help
1361 This feature enables the kernel to p 1170 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1171 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1172 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1173 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1174 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1175 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1176 deadlock.
1368 1177
1369 In short, this feature enables the k 1178 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1179 related deadlocks before they actually occur.
1371 1180
1372 The proof does not depend on how har 1181 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1182 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1183 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1184 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1185 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1186 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1187 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1188 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1189 makes the deadlock theoretically possible).
1381 1190
1382 If a deadlock is impossible (i.e. th 1191 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1192 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1193 kernel reports nothing.
1385 1194
1386 NOTE: this feature can also be enabl 1195 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1196 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1197 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1198 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1199 arbitrary combination of these separate locking variants.
1391 1200
1392 For more details, see Documentation/ 1201 For more details, see Documentation/locking/lockdep-design.rst.
1393 1202
1394 config PROVE_RAW_LOCK_NESTING 1203 config PROVE_RAW_LOCK_NESTING
1395 bool "Enable raw_spinlock - spinlock 1204 bool "Enable raw_spinlock - spinlock nesting checks"
1396 depends on PROVE_LOCKING 1205 depends on PROVE_LOCKING
1397 default n 1206 default n
1398 help 1207 help
1399 Enable the raw_spinlock vs. spinlock 1208 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400 that the lock nesting rules for PREE 1209 that the lock nesting rules for PREEMPT_RT enabled kernels are
1401 not violated. 1210 not violated.
1402 1211
1403 NOTE: There are known nesting proble 1212 NOTE: There are known nesting problems. So if you enable this
1404 option expect lockdep splats until t 1213 option expect lockdep splats until these problems have been fully
1405 addressed which is work in progress. 1214 addressed which is work in progress. This config switch allows to
1406 identify and analyze these problems. 1215 identify and analyze these problems. It will be removed and the
1407 check permanently enabled once the m !! 1216 check permanentely enabled once the main issues have been fixed.
1408 1217
1409 If unsure, select N. 1218 If unsure, select N.
1410 1219
1411 config LOCK_STAT 1220 config LOCK_STAT
1412 bool "Lock usage statistics" 1221 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1222 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1223 select LOCKDEP
1415 select DEBUG_SPINLOCK 1224 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1225 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1226 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1227 select DEBUG_LOCK_ALLOC
1419 default n 1228 default n
1420 help 1229 help
1421 This feature enables tracking lock c 1230 This feature enables tracking lock contention points
1422 1231
1423 For more details, see Documentation/ 1232 For more details, see Documentation/locking/lockstat.rst
1424 1233
1425 This also enables lock events requir 1234 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1235 subcommand of perf.
1427 If you want to use "perf lock", you 1236 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1237 CONFIG_EVENT_TRACING.
1429 1238
1430 CONFIG_LOCK_STAT defines "contended" 1239 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1240 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1241
1433 config DEBUG_RT_MUTEXES 1242 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1243 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1244 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1245 help
1437 This allows rt mutex semantics viola 1246 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1247 deadlocks (lockups) to be detected and reported automatically.
1439 1248
1440 config DEBUG_SPINLOCK 1249 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1250 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1251 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1252 select UNINLINE_SPIN_UNLOCK
1444 help 1253 help
1445 Say Y here and build SMP to catch m 1254 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1255 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1256 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1257 deadlocks are also debuggable.
1449 1258
1450 config DEBUG_MUTEXES 1259 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1260 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1261 depends on DEBUG_KERNEL
1453 help 1262 help
1454 This feature allows mutex semantics 1263 This feature allows mutex semantics violations to be detected and
1455 reported. 1264 reported.
1456 1265
1457 config DEBUG_WW_MUTEX_SLOWPATH 1266 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1267 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1268 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1269 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1270 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1271 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1272 help
1465 This feature enables slowpath testin 1273 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1274 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1275 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1276 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1277 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1278 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1279 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1280 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1281 you are a distro, do not.
1474 1282
1475 config DEBUG_RWSEMS 1283 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1284 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1285 depends on DEBUG_KERNEL
1478 help 1286 help
1479 This debugging feature allows misma 1287 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1288 and unlocks to be detected and reported.
1481 1289
1482 config DEBUG_LOCK_ALLOC 1290 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1291 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1292 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1293 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1294 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1295 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1296 select LOCKDEP
1489 help 1297 help
1490 This feature will check whether any 1298 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1299 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1300 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1301 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1302 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1303 held during task exit.
1496 1304
1497 config LOCKDEP 1305 config LOCKDEP
1498 bool 1306 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1307 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1308 select STACKTRACE
1501 select KALLSYMS 1309 select KALLSYMS
1502 select KALLSYMS_ALL 1310 select KALLSYMS_ALL
1503 1311
1504 config LOCKDEP_SMALL 1312 config LOCKDEP_SMALL
1505 bool 1313 bool
1506 1314
1507 config LOCKDEP_BITS 1315 config LOCKDEP_BITS
1508 int "Bitsize for MAX_LOCKDEP_ENTRIES" 1316 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1509 depends on LOCKDEP && !LOCKDEP_SMALL 1317 depends on LOCKDEP && !LOCKDEP_SMALL
1510 range 10 30 1318 range 10 30
1511 default 15 1319 default 15
1512 help 1320 help
1513 Try increasing this value if you hi 1321 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1514 1322
1515 config LOCKDEP_CHAINS_BITS 1323 config LOCKDEP_CHAINS_BITS
1516 int "Bitsize for MAX_LOCKDEP_CHAINS" 1324 int "Bitsize for MAX_LOCKDEP_CHAINS"
1517 depends on LOCKDEP && !LOCKDEP_SMALL 1325 depends on LOCKDEP && !LOCKDEP_SMALL
1518 range 10 30 1326 range 10 30
1519 default 16 1327 default 16
1520 help 1328 help
1521 Try increasing this value if you hi 1329 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1522 1330
1523 config LOCKDEP_STACK_TRACE_BITS 1331 config LOCKDEP_STACK_TRACE_BITS
1524 int "Bitsize for MAX_STACK_TRACE_ENTR 1332 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1525 depends on LOCKDEP && !LOCKDEP_SMALL 1333 depends on LOCKDEP && !LOCKDEP_SMALL
1526 range 10 30 1334 range 10 30
1527 default 19 1335 default 19
1528 help 1336 help
1529 Try increasing this value if you hi 1337 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1530 1338
1531 config LOCKDEP_STACK_TRACE_HASH_BITS 1339 config LOCKDEP_STACK_TRACE_HASH_BITS
1532 int "Bitsize for STACK_TRACE_HASH_SIZ 1340 int "Bitsize for STACK_TRACE_HASH_SIZE"
1533 depends on LOCKDEP && !LOCKDEP_SMALL 1341 depends on LOCKDEP && !LOCKDEP_SMALL
1534 range 10 30 1342 range 10 30
1535 default 14 1343 default 14
1536 help 1344 help
1537 Try increasing this value if you ne !! 1345 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1538 1346
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS 1347 config LOCKDEP_CIRCULAR_QUEUE_BITS
1540 int "Bitsize for elements in circular 1348 int "Bitsize for elements in circular_queue struct"
1541 depends on LOCKDEP 1349 depends on LOCKDEP
1542 range 10 30 1350 range 10 30
1543 default 12 1351 default 12
1544 help 1352 help
1545 Try increasing this value if you hi 1353 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1546 1354
1547 config DEBUG_LOCKDEP 1355 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1356 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1357 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS <<
1551 help 1358 help
1552 If you say Y here, the lock depende 1359 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1360 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1361 of more runtime overhead.
1555 1362
1556 config DEBUG_ATOMIC_SLEEP 1363 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1364 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1365 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1366 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1367 depends on !ARCH_NO_PREEMPT
1561 help 1368 help
1562 If you say Y here, various routines 1369 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1370 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1371 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1372 sections, inside an interrupt, etc...
1566 1373
1567 config DEBUG_LOCKING_API_SELFTESTS 1374 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1375 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1376 depends on DEBUG_KERNEL
1570 help 1377 help
1571 Say Y here if you want the kernel t 1378 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1379 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1380 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1381 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1382 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1383 mutexes and rwsems.
1577 1384
1578 config LOCK_TORTURE_TEST 1385 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1386 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1387 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1388 select TORTURE_TEST
1582 help 1389 help
1583 This option provides a kernel modul 1390 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1391 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1392 after the fact on the running kernel to be tested, if desired.
1586 1393
1587 Say Y here if you want kernel locki 1394 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1395 to be built into the kernel.
1589 Say M if you want these torture tes 1396 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1397 Say N if you are unsure.
1591 1398
1592 config WW_MUTEX_SELFTEST 1399 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1400 tristate "Wait/wound mutex selftests"
1594 help 1401 help
1595 This option provides a kernel modul 1402 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1403 on the struct ww_mutex locking API.
1597 1404
1598 It is recommended to enable DEBUG_W 1405 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1406 with this test harness.
1600 1407
1601 Say M if you want these self tests 1408 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1409 Say N if you are unsure.
1603 1410
1604 config SCF_TORTURE_TEST 1411 config SCF_TORTURE_TEST
1605 tristate "torture tests for smp_call_ 1412 tristate "torture tests for smp_call_function*()"
1606 depends on DEBUG_KERNEL 1413 depends on DEBUG_KERNEL
1607 select TORTURE_TEST 1414 select TORTURE_TEST
1608 help 1415 help
1609 This option provides a kernel modul 1416 This option provides a kernel module that runs torture tests
1610 on the smp_call_function() family o 1417 on the smp_call_function() family of primitives. The kernel
1611 module may be built after the fact 1418 module may be built after the fact on the running kernel to
1612 be tested, if desired. 1419 be tested, if desired.
1613 1420
1614 config CSD_LOCK_WAIT_DEBUG 1421 config CSD_LOCK_WAIT_DEBUG
1615 bool "Debugging for csd_lock_wait(), 1422 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616 depends on DEBUG_KERNEL 1423 depends on DEBUG_KERNEL
1617 depends on 64BIT 1424 depends on 64BIT
1618 default n 1425 default n
1619 help 1426 help
1620 This option enables debug prints wh 1427 This option enables debug prints when CPUs are slow to respond
1621 to the smp_call_function*() IPI wra 1428 to the smp_call_function*() IPI wrappers. These debug prints
1622 include the IPI handler function cu 1429 include the IPI handler function currently executing (if any)
1623 and relevant stack traces. 1430 and relevant stack traces.
1624 1431
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 1432 endmenu # lock debugging
1635 1433
1636 config TRACE_IRQFLAGS 1434 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT 1435 depends on TRACE_IRQFLAGS_SUPPORT
1638 bool 1436 bool
1639 help 1437 help
1640 Enables hooks to interrupt enabling 1438 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1439 either tracing or lock debugging.
1642 1440
1643 config TRACE_IRQFLAGS_NMI 1441 config TRACE_IRQFLAGS_NMI
1644 def_bool y 1442 def_bool y
1645 depends on TRACE_IRQFLAGS 1443 depends on TRACE_IRQFLAGS
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT 1444 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647 1445
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 1446 config STACKTRACE
1667 bool "Stack backtrace support" 1447 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1448 depends on STACKTRACE_SUPPORT
1669 help 1449 help
1670 This option causes the kernel to cr 1450 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1451 every process, showing its current stack trace.
1672 It is also used by various kernel d 1452 It is also used by various kernel debugging features that require
1673 stack trace generation. 1453 stack trace generation.
1674 1454
1675 config WARN_ALL_UNSEEDED_RANDOM 1455 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1456 bool "Warn for all uses of unseeded randomness"
1677 default n 1457 default n
1678 help 1458 help
1679 Some parts of the kernel contain bu 1459 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1460 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1461 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1462 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1463 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1464 are going wrong, so that they might contact developers about fixing
1685 it. 1465 it.
1686 1466
1687 Unfortunately, on some models of so 1467 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1468 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1469 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1470 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1471 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1472 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1473 However, since users cannot do anything actionable to
1694 address this, by default this optio 1474 address this, by default this option is disabled.
1695 1475
1696 Say Y here if you want to receive w 1476 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1477 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1478 those developers interested in improving the security of
1699 Linux kernels running on their arch 1479 Linux kernels running on their architecture (or
1700 subarchitecture). 1480 subarchitecture).
1701 1481
1702 config DEBUG_KOBJECT 1482 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1483 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1484 depends on DEBUG_KERNEL
1705 help 1485 help
1706 If you say Y here, some extra kobje 1486 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1487 to the syslog.
1708 1488
1709 config DEBUG_KOBJECT_RELEASE 1489 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1490 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1491 depends on DEBUG_OBJECTS_TIMERS
1712 help 1492 help
1713 kobjects are reference counted obje 1493 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1494 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1495 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1496 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1497 example of this would be a struct device which has just been
1718 unregistered. 1498 unregistered.
1719 1499
1720 However, some buggy drivers assume 1500 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1501 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1502 goes completely against the principles of a refcounted object.
1723 1503
1724 If you say Y here, the kernel will 1504 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1505 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1506 kind of kobject release bug.
1727 1507
1728 config HAVE_DEBUG_BUGVERBOSE 1508 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1509 bool
1730 1510
1731 menu "Debug kernel data structures" 1511 menu "Debug kernel data structures"
1732 1512
1733 config DEBUG_LIST 1513 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1514 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1515 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1516 help
1738 Enable this to turn on extended che !! 1517 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1518 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 1519
1745 If unsure, say N. 1520 If unsure, say N.
1746 1521
1747 config DEBUG_PLIST 1522 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1523 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1524 depends on DEBUG_KERNEL
1750 help 1525 help
1751 Enable this to turn on extended che 1526 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1527 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1528 list multiple times during each manipulation.
1754 1529
1755 If unsure, say N. 1530 If unsure, say N.
1756 1531
1757 config DEBUG_SG 1532 config DEBUG_SG
1758 bool "Debug SG table operations" 1533 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1534 depends on DEBUG_KERNEL
1760 help 1535 help
1761 Enable this to turn on checks on sc 1536 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1537 help find problems with drivers that do not properly initialize
1763 their sg tables. 1538 their sg tables.
1764 1539
1765 If unsure, say N. 1540 If unsure, say N.
1766 1541
1767 config DEBUG_NOTIFIERS 1542 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1543 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1544 depends on DEBUG_KERNEL
1770 help 1545 help
1771 Enable this to turn on sanity check 1546 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1547 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1548 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1549 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1550 performance, say N.
1776 1551
1777 config DEBUG_CLOSURES !! 1552 config BUG_ON_DATA_CORRUPTION
1778 bool "Debug closures (bcache async wi !! 1553 bool "Trigger a BUG when data corruption is detected"
1779 depends on CLOSURES !! 1554 select DEBUG_LIST
1780 select DEBUG_FS !! 1555 help
1781 help !! 1556 Select this option if the kernel should BUG when it encounters
1782 Keeps all active closures in a link !! 1557 data corruption in kernel memory structures when they get checked
1783 interface to list them, which makes !! 1558 for validity.
1784 operations that get stuck. !! 1559
>> 1560 If unsure, say N.
>> 1561
>> 1562 endmenu
1785 1563
1786 config DEBUG_MAPLE_TREE !! 1564 config DEBUG_CREDENTIALS
1787 bool "Debug maple trees" !! 1565 bool "Debug credential management"
1788 depends on DEBUG_KERNEL 1566 depends on DEBUG_KERNEL
1789 help 1567 help
1790 Enable maple tree debugging informa !! 1568 Enable this to turn on some debug checking for credential
>> 1569 management. The additional code keeps track of the number of
>> 1570 pointers from task_structs to any given cred struct, and checks to
>> 1571 see that this number never exceeds the usage count of the cred
>> 1572 struct.
1791 1573
1792 If unsure, say N. !! 1574 Furthermore, if SELinux is enabled, this also checks that the
>> 1575 security pointer in the cred struct is never seen to be invalid.
1793 1576
1794 endmenu !! 1577 If unsure, say N.
1795 1578
1796 source "kernel/rcu/Kconfig.debug" 1579 source "kernel/rcu/Kconfig.debug"
1797 1580
1798 config DEBUG_WQ_FORCE_RR_CPU 1581 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1582 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1583 depends on DEBUG_KERNEL
1801 default n 1584 default n
1802 help 1585 help
1803 Workqueue used to implicitly guaran 1586 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1587 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1588 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1589 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1590 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1591 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1592 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1593 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1594 be impacted.
1812 1595
>> 1596 config DEBUG_BLOCK_EXT_DEVT
>> 1597 bool "Force extended block device numbers and spread them"
>> 1598 depends on DEBUG_KERNEL
>> 1599 depends on BLOCK
>> 1600 default n
>> 1601 help
>> 1602 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1603 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1604 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1605 is broken.
>> 1606
>> 1607 Conventionally, block device numbers are allocated from
>> 1608 predetermined contiguous area. However, extended block area
>> 1609 may introduce non-contiguous block device numbers. This
>> 1610 option forces most block device numbers to be allocated from
>> 1611 the extended space and spreads them to discover kernel or
>> 1612 userland code paths which assume predetermined contiguous
>> 1613 device number allocation.
>> 1614
>> 1615 Note that turning on this debug option shuffles all the
>> 1616 device numbers for all IDE and SCSI devices including libata
>> 1617 ones, so root partition specified using device number
>> 1618 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1619 Textual device names (root=/dev/sdXn) will continue to work.
>> 1620
>> 1621 Say N if you are unsure.
>> 1622
1813 config CPU_HOTPLUG_STATE_CONTROL 1623 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1624 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1625 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1626 depends on HOTPLUG_CPU
1817 default n 1627 default n
1818 help 1628 help
1819 Allows to write steps between "offl 1629 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1630 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1631 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1632 restarted at arbitrary points yet.
1823 1633
1824 Say N if your are unsure. 1634 Say N if your are unsure.
1825 1635
1826 config LATENCYTOP 1636 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1637 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1638 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1639 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1640 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P 1641 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832 select KALLSYMS 1642 select KALLSYMS
1833 select KALLSYMS_ALL 1643 select KALLSYMS_ALL
1834 select STACKTRACE 1644 select STACKTRACE
1835 select SCHEDSTATS 1645 select SCHEDSTATS
>> 1646 select SCHED_DEBUG
1836 help 1647 help
1837 Enable this option if you want to u 1648 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1649 to find out which userspace is blocking on what kernel operations.
1839 1650
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" 1651 source "kernel/trace/Kconfig"
1851 1652
1852 config PROVIDE_OHCI1394_DMA_INIT 1653 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1654 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1655 depends on PCI && X86
1855 help 1656 help
1856 If you want to debug problems which 1657 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1658 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1659 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1660 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1661 specification which is now the standard for FireWire controllers.
1861 1662
1862 With remote DMA, you can monitor th 1663 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1664 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1665 Even controlling a kernel debugger is possible using remote DMA.
1865 1666
1866 Usage: 1667 Usage:
1867 1668
1868 If ohci1394_dma=early is used as bo 1669 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1670 all OHCI1394 controllers which are found in the PCI config space.
1870 1671
1871 As all changes to the FireWire bus 1672 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1673 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1674 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1675 the debugging host before booting the debug target for debugging.
1875 1676
1876 This code (~1k) is freed after boot 1677 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1678 in charge of the OHCI-1394 controllers should be used instead.
1878 1679
1879 See Documentation/core-api/debuggin 1680 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880 1681
1881 source "samples/Kconfig" 1682 source "samples/Kconfig"
1882 1683
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1684 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1685 bool
1885 1686
1886 config STRICT_DEVMEM 1687 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1688 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1689 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED !! 1690 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1691 default y if PPC || X86 || ARM64
1891 help 1692 help
1892 If this option is disabled, you all 1693 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1694 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1695 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1696 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1697 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1698 use due to the cache aliasing requirements.
1898 1699
1899 If this option is switched on, and 1700 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1701 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1702 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1703 users of /dev/mem.
1903 1704
1904 If in doubt, say Y. 1705 If in doubt, say Y.
1905 1706
1906 config IO_STRICT_DEVMEM 1707 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1708 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1709 depends on STRICT_DEVMEM
1909 help 1710 help
1910 If this option is disabled, you all 1711 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1712 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1713 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1714 specific access can be used by people debugging kernel drivers.
1914 1715
1915 If this option is switched on, the 1716 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1717 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1718 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1719 if the driver using a given range cannot be disabled.
1919 1720
1920 If in doubt, say Y. 1721 If in doubt, say Y.
1921 1722
1922 menu "$(SRCARCH) Debugging" 1723 menu "$(SRCARCH) Debugging"
1923 1724
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1725 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1726
1926 endmenu 1727 endmenu
1927 1728
1928 menu "Kernel Testing and Coverage" 1729 menu "Kernel Testing and Coverage"
1929 1730
1930 source "lib/kunit/Kconfig" 1731 source "lib/kunit/Kconfig"
1931 1732
1932 config NOTIFIER_ERROR_INJECTION 1733 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1734 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1735 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1736 select DEBUG_FS
1936 help 1737 help
1937 This option provides the ability to 1738 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1739 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1740 handling of notifier call chain failures.
1940 1741
1941 Say N if unsure. 1742 Say N if unsure.
1942 1743
1943 config PM_NOTIFIER_ERROR_INJECT 1744 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1745 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1746 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1747 default m if PM_DEBUG
1947 help 1748 help
1948 This option provides the ability to 1749 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1750 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1751 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1752
1952 If the notifier call chain should b 1753 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1754 notified, write the error code to "actions/<notifier event>/error".
1954 1755
1955 Example: Inject PM suspend error (- 1756 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1757
1957 # cd /sys/kernel/debug/notifier-err 1758 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1759 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1760 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1761 bash: echo: write error: Cannot allocate memory
1961 1762
1962 To compile this code as a module, c 1763 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1764 be called pm-notifier-error-inject.
1964 1765
1965 If unsure, say N. 1766 If unsure, say N.
1966 1767
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1768 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1769 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1770 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1771 help
1971 This option provides the ability to 1772 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1773 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1774 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1775 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1776
1976 If the notifier call chain should b 1777 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1778 notified, write the error code to "actions/<notifier event>/error".
1978 1779
1979 To compile this code as a module, c 1780 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1781 be called of-reconfig-notifier-error-inject.
1981 1782
1982 If unsure, say N. 1783 If unsure, say N.
1983 1784
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1785 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1786 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1787 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1788 help
1988 This option provides the ability to 1789 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1790 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1791 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1792
1992 If the notifier call chain should b 1793 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1794 notified, write the error code to "actions/<notifier event>/error".
1994 1795
1995 Example: Inject netdevice mtu chang 1796 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1797
1997 # cd /sys/kernel/debug/notifier-err 1798 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1799 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1800 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1801 RTNETLINK answers: Invalid argument
2001 1802
2002 To compile this code as a module, c 1803 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1804 be called netdev-notifier-error-inject.
2004 1805
2005 If unsure, say N. 1806 If unsure, say N.
2006 1807
2007 config FUNCTION_ERROR_INJECTION 1808 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" 1809 bool "Fault-injections of functions"
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1810 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010 help 1811 help
2011 Add fault injections into various f 1812 Add fault injections into various functions that are annotated with
2012 ALLOW_ERROR_INJECTION() in the kern 1813 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
2013 value of these functions. This is u !! 1814 value of theses functions. This is useful to test error paths of code.
2014 1815
2015 If unsure, say N 1816 If unsure, say N
2016 1817
2017 config FAULT_INJECTION 1818 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1819 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1820 depends on DEBUG_KERNEL
2020 help 1821 help
2021 Provide fault-injection framework. 1822 Provide fault-injection framework.
2022 For more details, see Documentation 1823 For more details, see Documentation/fault-injection/.
2023 1824
2024 config FAILSLAB 1825 config FAILSLAB
2025 bool "Fault-injection capability for 1826 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1827 depends on FAULT_INJECTION
>> 1828 depends on SLAB || SLUB
2027 help 1829 help
2028 Provide fault-injection capability 1830 Provide fault-injection capability for kmalloc.
2029 1831
2030 config FAIL_PAGE_ALLOC 1832 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for 1833 bool "Fault-injection capability for alloc_pages()"
2032 depends on FAULT_INJECTION 1834 depends on FAULT_INJECTION
2033 help 1835 help
2034 Provide fault-injection capability 1836 Provide fault-injection capability for alloc_pages().
2035 1837
2036 config FAULT_INJECTION_USERCOPY 1838 config FAULT_INJECTION_USERCOPY
2037 bool "Fault injection capability for 1839 bool "Fault injection capability for usercopy functions"
2038 depends on FAULT_INJECTION 1840 depends on FAULT_INJECTION
2039 help 1841 help
2040 Provides fault-injection capability 1842 Provides fault-injection capability to inject failures
2041 in usercopy functions (copy_from_us 1843 in usercopy functions (copy_from_user(), get_user(), ...).
2042 1844
2043 config FAIL_MAKE_REQUEST 1845 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1846 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1847 depends on FAULT_INJECTION && BLOCK
2046 help 1848 help
2047 Provide fault-injection capability 1849 Provide fault-injection capability for disk IO.
2048 1850
2049 config FAIL_IO_TIMEOUT 1851 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1852 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1853 depends on FAULT_INJECTION && BLOCK
2052 help 1854 help
2053 Provide fault-injection capability 1855 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1856 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1857 thus exercising the error handling.
2056 1858
2057 Only works with drivers that use th 1859 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1860 for others it wont do anything.
2059 1861
2060 config FAIL_FUTEX 1862 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1863 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1864 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1865 depends on FAULT_INJECTION && FUTEX
2064 help 1866 help
2065 Provide fault-injection capability 1867 Provide fault-injection capability for futexes.
2066 1868
2067 config FAULT_INJECTION_DEBUG_FS 1869 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1870 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1871 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1872 help
2071 Enable configuration of fault-injec 1873 Enable configuration of fault-injection capabilities via debugfs.
2072 1874
2073 config FAIL_FUNCTION 1875 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1876 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1877 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1878 help
2077 Provide function-based fault-inject 1879 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1880 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1881 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1882 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1883 error handling in various subsystems.
2082 1884
2083 config FAIL_MMC_REQUEST 1885 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1886 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1887 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1888 help
2087 Provide fault-injection capability 1889 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1890 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1891 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1892 and to test how the mmc host driver handles retries from
2091 the block device. 1893 the block device.
2092 1894
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 1895 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1896 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1897 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1898 depends on !X86_64
2115 select STACKTRACE 1899 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P 1900 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117 help 1901 help
2118 Provide stacktrace filter for fault 1902 Provide stacktrace filter for fault-injection capabilities
2119 1903
2120 config ARCH_HAS_KCOV 1904 config ARCH_HAS_KCOV
2121 bool 1905 bool
2122 help 1906 help
2123 An architecture should select this 1907 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 1908 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 1909 disabling instrumentation for some early boot code.
2126 1910
2127 config CC_HAS_SANCOV_TRACE_PC 1911 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 1912 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 1913
2130 1914
2131 config KCOV 1915 config KCOV
2132 bool "Code coverage for fuzzing" 1916 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 1917 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 1918 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 1919 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 1920 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK <<
2140 help 1921 help
2141 KCOV exposes kernel code coverage i 1922 KCOV exposes kernel code coverage information in a form suitable
2142 for coverage-guided fuzzing (random 1923 for coverage-guided fuzzing (randomized testing).
2143 1924
>> 1925 If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> 1926 different machines and across reboots. If you need stable PC values,
>> 1927 disable RANDOMIZE_BASE.
>> 1928
2144 For more details, see Documentation 1929 For more details, see Documentation/dev-tools/kcov.rst.
2145 1930
2146 config KCOV_ENABLE_COMPARISONS 1931 config KCOV_ENABLE_COMPARISONS
2147 bool "Enable comparison operands coll 1932 bool "Enable comparison operands collection by KCOV"
2148 depends on KCOV 1933 depends on KCOV
2149 depends on $(cc-option,-fsanitize-cov 1934 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150 help 1935 help
2151 KCOV also exposes operands of every 1936 KCOV also exposes operands of every comparison in the instrumented
2152 code along with operand sizes and P 1937 code along with operand sizes and PCs of the comparison instructions.
2153 These operands can be used by fuzzi 1938 These operands can be used by fuzzing engines to improve the quality
2154 of fuzzing coverage. 1939 of fuzzing coverage.
2155 1940
2156 config KCOV_INSTRUMENT_ALL 1941 config KCOV_INSTRUMENT_ALL
2157 bool "Instrument all code by default" 1942 bool "Instrument all code by default"
2158 depends on KCOV 1943 depends on KCOV
2159 default y 1944 default y
2160 help 1945 help
2161 If you are doing generic system cal 1946 If you are doing generic system call fuzzing (like e.g. syzkaller),
2162 then you will want to instrument th 1947 then you will want to instrument the whole kernel and you should
2163 say y here. If you are doing more t 1948 say y here. If you are doing more targeted fuzzing (like e.g.
2164 filesystem fuzzing with AFL) then y 1949 filesystem fuzzing with AFL) then you will want to enable coverage
2165 for more specific subsets of files, 1950 for more specific subsets of files, and should say n here.
2166 1951
2167 config KCOV_IRQ_AREA_SIZE 1952 config KCOV_IRQ_AREA_SIZE
2168 hex "Size of interrupt coverage colle 1953 hex "Size of interrupt coverage collection area in words"
2169 depends on KCOV 1954 depends on KCOV
2170 default 0x40000 1955 default 0x40000
2171 help 1956 help
2172 KCOV uses preallocated per-cpu area 1957 KCOV uses preallocated per-cpu areas to collect coverage from
2173 soft interrupts. This specifies the 1958 soft interrupts. This specifies the size of those areas in the
2174 number of unsigned long words. 1959 number of unsigned long words.
2175 1960
2176 menuconfig RUNTIME_TESTING_MENU 1961 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 1962 bool "Runtime Testing"
2178 default y !! 1963 def_bool y
2179 1964
2180 if RUNTIME_TESTING_MENU 1965 if RUNTIME_TESTING_MENU
2181 1966
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 1967 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 1968 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 1969 depends on DEBUG_FS
2220 help 1970 help
2221 This module enables testing of the di 1971 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 1972 inducing system failures at predefined crash points.
2223 If you don't need it: say N 1973 If you don't need it: say N
2224 Choose M here to compile this code as 1974 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 1975 called lkdtm.
2226 1976
2227 Documentation on how to use the modul 1977 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 1978 Documentation/fault-injection/provoke-crashes.rst
2229 1979
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 1980 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 1981 tristate "Linked list sorting test"
2244 depends on KUNIT !! 1982 depends on DEBUG_KERNEL || m
2245 default KUNIT_ALL_TESTS <<
2246 help 1983 help
2247 Enable this to turn on 'list_sort() 1984 Enable this to turn on 'list_sort()' function test. This test is
2248 executed only once during system bo 1985 executed only once during system boot (so affects only boot time),
2249 or at module load time. 1986 or at module load time.
2250 1987
2251 If unsure, say N. 1988 If unsure, say N.
2252 1989
2253 config TEST_MIN_HEAP 1990 config TEST_MIN_HEAP
2254 tristate "Min heap test" 1991 tristate "Min heap test"
2255 depends on DEBUG_KERNEL || m 1992 depends on DEBUG_KERNEL || m
2256 help 1993 help
2257 Enable this to turn on min heap fun 1994 Enable this to turn on min heap function tests. This test is
2258 executed only once during system bo 1995 executed only once during system boot (so affects only boot time),
2259 or at module load time. 1996 or at module load time.
2260 1997
2261 If unsure, say N. 1998 If unsure, say N.
2262 1999
2263 config TEST_SORT 2000 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 2001 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 2002 depends on DEBUG_KERNEL || m
2276 help 2003 help
2277 Enable this to turn on 'do_div()' f !! 2004 This option enables the self-test function of 'sort()' at boot,
2278 executed only once during system bo <<
2279 or at module load time. 2005 or at module load time.
2280 2006
2281 If unsure, say N. 2007 If unsure, say N.
2282 2008
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 2009 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 2010 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 2011 depends on DEBUG_KERNEL
2298 depends on KPROBES 2012 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 2013 help
2303 This option provides for testing ba 2014 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 2015 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 2016 verified for functionality.
2306 2017
2307 Say N if you are unsure. 2018 Say N if you are unsure.
2308 2019
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 2020 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 2021 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 2022 depends on DEBUG_KERNEL
2324 help 2023 help
2325 This option provides a kernel modul 2024 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 2025 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 2026 for distributions or general kernels, but only for kernel
2328 developers working on architecture 2027 developers working on architecture code.
2329 2028
2330 Note that if you want to also test 2029 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 2030 have to enable STACKTRACE as well.
2332 2031
2333 Say N if you are unsure. 2032 Say N if you are unsure.
2334 2033
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 2034 config RBTREE_TEST
2346 tristate "Red-Black tree test" 2035 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 2036 depends on DEBUG_KERNEL
2348 help 2037 help
2349 A benchmark measuring the performan 2038 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 2039 Also includes rbtree invariant checks.
2351 2040
2352 config REED_SOLOMON_TEST 2041 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 2042 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 2043 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 2044 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 2045 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 2046 select REED_SOLOMON_DEC16
2358 help 2047 help
2359 This option enables the self-test f 2048 This option enables the self-test function of rslib at boot,
2360 or at module load time. 2049 or at module load time.
2361 2050
2362 If unsure, say N. 2051 If unsure, say N.
2363 2052
2364 config INTERVAL_TREE_TEST 2053 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 2054 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 2055 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 2056 select INTERVAL_TREE
2368 help 2057 help
2369 A benchmark measuring the performan 2058 A benchmark measuring the performance of the interval tree library
2370 2059
2371 config PERCPU_TEST 2060 config PERCPU_TEST
2372 tristate "Per cpu operations test" 2061 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 2062 depends on m && DEBUG_KERNEL
2374 help 2063 help
2375 Enable this option to build test mo 2064 Enable this option to build test module which validates per-cpu
2376 operations. 2065 operations.
2377 2066
2378 If unsure, say N. 2067 If unsure, say N.
2379 2068
2380 config ATOMIC64_SELFTEST 2069 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 2070 tristate "Perform an atomic64_t self-test"
2382 help 2071 help
2383 Enable this option to test the atom 2072 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 2073 at module load time.
2385 2074
2386 If unsure, say N. 2075 If unsure, say N.
2387 2076
2388 config ASYNC_RAID6_TEST 2077 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 2078 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 2079 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 2080 select ASYNC_MEMCPY
2392 help 2081 help
2393 This is a one-shot self test that p 2082 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 2083 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 2084 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 2085 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 2086 engine if one is available.
2398 2087
2399 If unsure, say N. 2088 If unsure, say N.
2400 2089
2401 config TEST_HEXDUMP 2090 config TEST_HEXDUMP
2402 tristate "Test functions located in t 2091 tristate "Test functions located in the hexdump module at runtime"
2403 2092
2404 config STRING_KUNIT_TEST !! 2093 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 2094 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 2095
2409 config STRING_HELPERS_KUNIT_TEST !! 2096 config TEST_STRSCPY
2410 tristate "KUnit test string helpers a !! 2097 tristate "Test strscpy*() family of functions at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 2098
2414 config TEST_KSTRTOX 2099 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 2100 tristate "Test kstrto*() family of functions at runtime"
2416 2101
2417 config TEST_PRINTF 2102 config TEST_PRINTF
2418 tristate "Test printf() family of fun 2103 tristate "Test printf() family of functions at runtime"
2419 2104
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 2105 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 2106 tristate "Test bitmap_*() family of functions at runtime"
2425 help 2107 help
2426 Enable this option to test the bitm 2108 Enable this option to test the bitmap functions at boot.
2427 2109
2428 If unsure, say N. 2110 If unsure, say N.
2429 2111
2430 config TEST_UUID 2112 config TEST_UUID
2431 tristate "Test functions located in t 2113 tristate "Test functions located in the uuid module at runtime"
2432 2114
2433 config TEST_XARRAY 2115 config TEST_XARRAY
2434 tristate "Test the XArray code at run 2116 tristate "Test the XArray code at runtime"
2435 2117
2436 config TEST_MAPLE_TREE !! 2118 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 2119 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 2120
2445 config TEST_RHASHTABLE 2121 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 2122 tristate "Perform selftest on resizable hash table"
2447 help 2123 help
2448 Enable this option to test the rhas 2124 Enable this option to test the rhashtable functions at boot.
2449 2125
2450 If unsure, say N. 2126 If unsure, say N.
2451 2127
>> 2128 config TEST_HASH
>> 2129 tristate "Perform selftest on hash functions"
>> 2130 help
>> 2131 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 2132 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 2133 hash functions on boot (or module load).
>> 2134
>> 2135 This is intended to help people writing architecture-specific
>> 2136 optimized versions. If unsure, say N.
>> 2137
2452 config TEST_IDA 2138 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 2139 tristate "Perform selftest on IDA functions"
2454 2140
2455 config TEST_PARMAN 2141 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 2142 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 2143 depends on PARMAN
2458 help 2144 help
2459 Enable this option to test priority 2145 Enable this option to test priority array manager on boot
2460 (or module load). 2146 (or module load).
2461 2147
2462 If unsure, say N. 2148 If unsure, say N.
2463 2149
2464 config TEST_IRQ_TIMINGS 2150 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 2151 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 2152 depends on IRQ_TIMINGS
2467 help 2153 help
2468 Enable this option to test the irq 2154 Enable this option to test the irq timings code on boot.
2469 2155
2470 If unsure, say N. 2156 If unsure, say N.
2471 2157
2472 config TEST_LKM 2158 config TEST_LKM
2473 tristate "Test module loading with 'h 2159 tristate "Test module loading with 'hello world' module"
2474 depends on m 2160 depends on m
2475 help 2161 help
2476 This builds the "test_module" modul 2162 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 2163 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 2164 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 2165 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 2166 and will not normally be loaded by the system unless explicitly
2481 requested by name. 2167 requested by name.
2482 2168
2483 If unsure, say N. 2169 If unsure, say N.
2484 2170
2485 config TEST_BITOPS 2171 config TEST_BITOPS
2486 tristate "Test module for compilation 2172 tristate "Test module for compilation of bitops operations"
>> 2173 depends on m
2487 help 2174 help
2488 This builds the "test_bitops" modul 2175 This builds the "test_bitops" module that is much like the
2489 TEST_LKM module except that it does 2176 TEST_LKM module except that it does a basic exercise of the
2490 set/clear_bit macros and get_count_ 2177 set/clear_bit macros and get_count_order/long to make sure there are
2491 no compiler warnings from C=1 spars 2178 no compiler warnings from C=1 sparse checker or -Wextra
2492 compilations. It has no dependencie 2179 compilations. It has no dependencies and doesn't run or load unless
2493 explicitly requested by name. for 2180 explicitly requested by name. for example: modprobe test_bitops.
2494 2181
2495 If unsure, say N. 2182 If unsure, say N.
2496 2183
2497 config TEST_VMALLOC 2184 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 2185 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 2186 default n
2500 depends on MMU 2187 depends on MMU
2501 depends on m 2188 depends on m
2502 help 2189 help
2503 This builds the "test_vmalloc" modu 2190 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 2191 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 2192 subsystem can be evaluated from performance and stability point
2506 of view. 2193 of view.
2507 2194
2508 If unsure, say N. 2195 If unsure, say N.
2509 2196
>> 2197 config TEST_USER_COPY
>> 2198 tristate "Test user/kernel boundary protections"
>> 2199 depends on m
>> 2200 help
>> 2201 This builds the "test_user_copy" module that runs sanity checks
>> 2202 on the copy_to/from_user infrastructure, making sure basic
>> 2203 user/kernel boundary testing is working. If it fails to load,
>> 2204 a regression has been detected in the user/kernel memory boundary
>> 2205 protections.
>> 2206
>> 2207 If unsure, say N.
>> 2208
2510 config TEST_BPF 2209 config TEST_BPF
2511 tristate "Test BPF filter functionali 2210 tristate "Test BPF filter functionality"
2512 depends on m && NET 2211 depends on m && NET
2513 help 2212 help
2514 This builds the "test_bpf" module t 2213 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 2214 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 2215 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 2216 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 2217 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 2218 verifier used by user space verifier testsuite.
2520 2219
2521 If unsure, say N. 2220 If unsure, say N.
2522 2221
2523 config TEST_BLACKHOLE_DEV 2222 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 2223 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 2224 depends on m && NET
2526 help 2225 help
2527 This builds the "test_blackhole_dev 2226 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 2227 data path through this blackhole netdev.
2529 2228
2530 If unsure, say N. 2229 If unsure, say N.
2531 2230
2532 config FIND_BIT_BENCHMARK 2231 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 2232 tristate "Test find_bit functions"
2534 help 2233 help
2535 This builds the "test_find_bit" mod 2234 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2235 functions performance.
2537 2236
2538 If unsure, say N. 2237 If unsure, say N.
2539 2238
2540 config TEST_FIRMWARE 2239 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2240 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2241 depends on FW_LOADER
2543 help 2242 help
2544 This builds the "test_firmware" mod 2243 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2244 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2245 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2246 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2247 userspace.
2549 2248
2550 If unsure, say N. 2249 If unsure, say N.
2551 2250
2552 config TEST_SYSCTL 2251 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2252 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2253 depends on PROC_SYSCTL
2555 help 2254 help
2556 This builds the "test_sysctl" modul 2255 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2256 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2257 production knobs which might alter system functionality.
2559 2258
2560 If unsure, say N. 2259 If unsure, say N.
2561 2260
2562 config BITFIELD_KUNIT 2261 config BITFIELD_KUNIT
2563 tristate "KUnit test bitfield functio !! 2262 tristate "KUnit test bitfield functions at runtime"
2564 depends on KUNIT 2263 depends on KUNIT
2565 default KUNIT_ALL_TESTS <<
2566 help 2264 help
2567 Enable this option to test the bitf 2265 Enable this option to test the bitfield functions at boot.
2568 2266
2569 KUnit tests run during boot and out 2267 KUnit tests run during boot and output the results to the debug log
2570 in TAP format (http://testanything. 2268 in TAP format (http://testanything.org/). Only useful for kernel devs
2571 running the KUnit test harness, and 2269 running the KUnit test harness, and not intended for inclusion into a
2572 production build. 2270 production build.
2573 2271
2574 For more information on KUnit and u 2272 For more information on KUnit and unit tests in general please refer
2575 to the KUnit documentation in Docum 2273 to the KUnit documentation in Documentation/dev-tools/kunit/.
2576 2274
2577 If unsure, say N. 2275 If unsure, say N.
2578 2276
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 2277 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! 2278 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629 depends on KUNIT 2279 depends on KUNIT
2630 default KUNIT_ALL_TESTS 2280 default KUNIT_ALL_TESTS
2631 help 2281 help
2632 This builds the proc sysctl unit te 2282 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2283 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2284 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2285 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2286
2637 If unsure, say N. 2287 If unsure, say N.
2638 2288
2639 config LIST_KUNIT_TEST 2289 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke 2290 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641 depends on KUNIT 2291 depends on KUNIT
2642 default KUNIT_ALL_TESTS 2292 default KUNIT_ALL_TESTS
2643 help 2293 help
2644 This builds the linked list KUnit t 2294 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2295 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2296 and associated macros.
2647 2297
2648 KUnit tests run during boot and out 2298 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything 2299 in TAP format (https://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2300 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2301 production build.
2652 2302
2653 For more information on KUnit and u 2303 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2304 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2305
2656 If unsure, say N. 2306 If unsure, say N.
2657 2307
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 2308 config LINEAR_RANGES_TEST
2672 tristate "KUnit test for linear_range 2309 tristate "KUnit test for linear_ranges"
2673 depends on KUNIT 2310 depends on KUNIT
2674 select LINEAR_RANGES 2311 select LINEAR_RANGES
2675 help 2312 help
2676 This builds the linear_ranges unit 2313 This builds the linear_ranges unit test, which runs on boot.
2677 Tests the linear_ranges logic corre 2314 Tests the linear_ranges logic correctness.
2678 For more information on KUnit and u 2315 For more information on KUnit and unit tests in general please refer
2679 to the KUnit documentation in Docum 2316 to the KUnit documentation in Documentation/dev-tools/kunit/.
2680 2317
2681 If unsure, say N. 2318 If unsure, say N.
2682 2319
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 2320 config BITS_TEST
2696 tristate "KUnit test for bits.h" if ! !! 2321 tristate "KUnit test for bits.h"
2697 depends on KUNIT 2322 depends on KUNIT
2698 default KUNIT_ALL_TESTS <<
2699 help 2323 help
2700 This builds the bits unit test. 2324 This builds the bits unit test.
2701 Tests the logic of macros defined i 2325 Tests the logic of macros defined in bits.h.
2702 For more information on KUnit and u 2326 For more information on KUnit and unit tests in general please refer
2703 to the KUnit documentation in Docum 2327 to the KUnit documentation in Documentation/dev-tools/kunit/.
2704 2328
2705 If unsure, say N. 2329 If unsure, say N.
2706 2330
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 2331 config TEST_UDELAY
2817 tristate "udelay test driver" 2332 tristate "udelay test driver"
2818 help 2333 help
2819 This builds the "udelay_test" modul 2334 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2335 that udelay() is working properly.
2821 2336
2822 If unsure, say N. 2337 If unsure, say N.
2823 2338
2824 config TEST_STATIC_KEYS 2339 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2340 tristate "Test static keys"
2826 depends on m 2341 depends on m
2827 help 2342 help
2828 Test the static key interfaces. 2343 Test the static key interfaces.
2829 2344
2830 If unsure, say N. 2345 If unsure, say N.
2831 2346
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 2347 config TEST_KMOD
2843 tristate "kmod stress tester" 2348 tristate "kmod stress tester"
2844 depends on m 2349 depends on m
2845 depends on NETDEVICES && NET_CORE && 2350 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2351 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 2352 select TEST_LKM
2849 select XFS_FS 2353 select XFS_FS
2850 select TUN 2354 select TUN
2851 select BTRFS_FS 2355 select BTRFS_FS
2852 help 2356 help
2853 Test the kernel's module loading me 2357 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2358 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2359 This test provides a series of tests against kmod.
2856 2360
2857 Although technically you can either 2361 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2362 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2363 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2364 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2365 module load requests, ultimately this could be fatal.
2862 2366
2863 To run tests run: 2367 To run tests run:
2864 2368
2865 tools/testing/selftests/kmod/kmod.s 2369 tools/testing/selftests/kmod/kmod.sh --help
2866 2370
2867 If unsure, say N. 2371 If unsure, say N.
2868 2372
2869 config TEST_DEBUG_VIRTUAL 2373 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2374 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2375 depends on DEBUG_VIRTUAL
2872 help 2376 help
2873 Test the kernel's ability to detect 2377 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2378 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2379 kernel's virtual address map.
2876 2380
2877 If unsure, say N. 2381 If unsure, say N.
2878 2382
2879 config TEST_MEMCAT_P 2383 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2384 tristate "Test memcat_p() helper function"
2881 help 2385 help
2882 Test the memcat_p() helper for corr 2386 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2387 pointer arrays together.
2884 2388
2885 If unsure, say N. 2389 If unsure, say N.
2886 2390
>> 2391 config TEST_LIVEPATCH
>> 2392 tristate "Test livepatching"
>> 2393 default n
>> 2394 depends on DYNAMIC_DEBUG
>> 2395 depends on LIVEPATCH
>> 2396 depends on m
>> 2397 help
>> 2398 Test kernel livepatching features for correctness. The tests will
>> 2399 load test modules that will be livepatched in various scenarios.
>> 2400
>> 2401 To run all the livepatching tests:
>> 2402
>> 2403 make -C tools/testing/selftests TARGETS=livepatch run_tests
>> 2404
>> 2405 Alternatively, individual tests may be invoked:
>> 2406
>> 2407 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2408 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2409 tools/testing/selftests/livepatch/test-shadow-vars.sh
>> 2410
>> 2411 If unsure, say N.
>> 2412
2887 config TEST_OBJAGG 2413 config TEST_OBJAGG
2888 tristate "Perform selftest on object 2414 tristate "Perform selftest on object aggreration manager"
2889 default n 2415 default n
2890 depends on OBJAGG 2416 depends on OBJAGG
2891 help 2417 help
2892 Enable this option to test object a 2418 Enable this option to test object aggregation manager on boot
2893 (or module load). 2419 (or module load).
2894 2420
>> 2421
>> 2422 config TEST_STACKINIT
>> 2423 tristate "Test level of stack variable initialization"
>> 2424 help
>> 2425 Test if the kernel is zero-initializing stack variables and
>> 2426 padding. Coverage is controlled by compiler flags,
>> 2427 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
>> 2428 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
>> 2429
>> 2430 If unsure, say N.
>> 2431
2895 config TEST_MEMINIT 2432 config TEST_MEMINIT
2896 tristate "Test heap/page initializati 2433 tristate "Test heap/page initialization"
2897 help 2434 help
2898 Test if the kernel is zero-initiali 2435 Test if the kernel is zero-initializing heap and page allocations.
2899 This can be useful to test init_on_ 2436 This can be useful to test init_on_alloc and init_on_free features.
2900 2437
2901 If unsure, say N. 2438 If unsure, say N.
2902 2439
2903 config TEST_HMM 2440 config TEST_HMM
2904 tristate "Test HMM (Heterogeneous Mem 2441 tristate "Test HMM (Heterogeneous Memory Management)"
2905 depends on TRANSPARENT_HUGEPAGE 2442 depends on TRANSPARENT_HUGEPAGE
2906 depends on DEVICE_PRIVATE 2443 depends on DEVICE_PRIVATE
2907 select HMM_MIRROR 2444 select HMM_MIRROR
2908 select MMU_NOTIFIER 2445 select MMU_NOTIFIER
2909 help 2446 help
2910 This is a pseudo device driver sole 2447 This is a pseudo device driver solely for testing HMM.
2911 Say M here if you want to build the 2448 Say M here if you want to build the HMM test module.
2912 Doing so will allow you to run tool 2449 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913 2450
2914 If unsure, say N. 2451 If unsure, say N.
2915 2452
2916 config TEST_FREE_PAGES 2453 config TEST_FREE_PAGES
2917 tristate "Test freeing pages" 2454 tristate "Test freeing pages"
2918 help 2455 help
2919 Test that a memory leak does not oc 2456 Test that a memory leak does not occur due to a race between
2920 freeing a block of pages and a spec 2457 freeing a block of pages and a speculative page reference.
2921 Loading this module is safe if your 2458 Loading this module is safe if your kernel has the bug fixed.
2922 If the bug is not fixed, it will le 2459 If the bug is not fixed, it will leak gigabytes of memory and
2923 probably OOM your system. 2460 probably OOM your system.
2924 2461
2925 config TEST_FPU 2462 config TEST_FPU
2926 tristate "Test floating point operati 2463 tristate "Test floating point operations in kernel space"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2464 depends on X86 && !KCOV_INSTRUMENT_ALL
2928 help 2465 help
2929 Enable this option to add /sys/kern 2466 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930 which will trigger a sequence of fl 2467 which will trigger a sequence of floating point operations. This is used
2931 for self-testing floating point con 2468 for self-testing floating point control register setting in
2932 kernel_fpu_begin(). 2469 kernel_fpu_begin().
2933 2470
2934 If unsure, say N. 2471 If unsure, say N.
2935 2472
2936 config TEST_CLOCKSOURCE_WATCHDOG <<
2937 tristate "Test clocksource watchdog i <<
2938 depends on CLOCKSOURCE_WATCHDOG <<
2939 help <<
2940 Enable this option to create a kern <<
2941 a test of the clocksource watchdog. <<
2942 via modprobe or insmod in which cas <<
2943 loaded, or it may be built in, in w <<
2944 shortly after boot. <<
2945 <<
2946 If unsure, say N. <<
2947 <<
2948 config TEST_OBJPOOL <<
2949 tristate "Test module for correctness <<
2950 default n <<
2951 depends on m && DEBUG_KERNEL <<
2952 help <<
2953 This builds the "test_objpool" modu <<
2954 correctness verification and concur <<
2955 allocation and reclamation. <<
2956 <<
2957 If unsure, say N. <<
2958 <<
2959 endif # RUNTIME_TESTING_MENU 2473 endif # RUNTIME_TESTING_MENU
2960 2474
2961 config ARCH_USE_MEMTEST <<
2962 bool <<
2963 help <<
2964 An architecture should select this <<
2965 during boot process. <<
2966 <<
2967 config MEMTEST 2475 config MEMTEST
2968 bool "Memtest" 2476 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST <<
2970 help 2477 help
2971 This option adds a kernel parameter 2478 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. !! 2479 to be set.
2973 memtest=0, mean disabled; -- 2480 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2481 memtest=1, mean do 1 test pattern;
2975 ... 2482 ...
2976 memtest=17, mean do 17 test p 2483 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2484 If you are unsure how to answer this question, answer N.
2978 2485
2979 2486
2980 2487
2981 config HYPERV_TESTING 2488 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2489 bool "Microsoft Hyper-V driver testing"
2983 default n 2490 default n
2984 depends on HYPERV && DEBUG_FS 2491 depends on HYPERV && DEBUG_FS
2985 help 2492 help
2986 Select this option to enable Hyper- 2493 Select this option to enable Hyper-V vmbus testing.
2987 2494
2988 endmenu # "Kernel Testing and Coverage" 2495 endmenu # "Kernel Testing and Coverage"
2989 2496
2990 menu "Rust hacking" !! 2497 source "Documentation/Kconfig"
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 2498
3053 endmenu # Kernel hacking 2499 endmenu # Kernel hacking
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