1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 menu "Kernel hacking" 2 menu "Kernel hacking"
3 3
4 menu "printk and dmesg options" 4 menu "printk and dmesg options"
5 5
6 config PRINTK_TIME 6 config PRINTK_TIME
7 bool "Show timing information on print 7 bool "Show timing information on printks"
8 depends on PRINTK 8 depends on PRINTK
9 help 9 help
10 Selecting this option causes time st 10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output o 11 messages to be added to the output of the syslog() system
12 call and at the console. 12 call and at the console.
13 13
14 The timestamp is always recorded int 14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifi 15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp 16 be included, not that the timestamp is recorded.
17 17
18 The behavior is also controlled by t 18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documen 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
20 20
21 config PRINTK_CALLER 21 config PRINTK_CALLER
22 bool "Show caller information on print 22 bool "Show caller information on printks"
23 depends on PRINTK 23 depends on PRINTK
24 help 24 help
25 Selecting this option causes printk( 25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "proces 26 in task context) or a caller "processor id" (if not in task context)
27 to every message. 27 to every message.
28 28
29 This option is intended for environm 29 This option is intended for environments where multiple threads
30 concurrently call printk() for many 30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where thes 31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple 32 line which was divided into multiple lines due to race) came from.
33 33
34 Since toggling after boot makes the 34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the k 35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface. 36 sysfs interface.
37 37
38 config STACKTRACE_BUILD_ID <<
39 bool "Show build ID information in sta <<
40 depends on PRINTK <<
41 help <<
42 Selecting this option adds build ID <<
43 stacktraces printed with the printk <<
44 <<
45 This option is intended for distros <<
46 accessible but can be downloaded giv <<
47 kernel module where the function is <<
48 <<
49 config CONSOLE_LOGLEVEL_DEFAULT 38 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)" 39 int "Default console loglevel (1-15)"
51 range 1 15 40 range 1 15
52 default "7" 41 default "7"
53 help 42 help
54 Default loglevel to determine what w 43 Default loglevel to determine what will be printed on the console.
55 44
56 Setting a default here is equivalent 45 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> co 46 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well. 47 value is specified here as well.
59 48
60 Note: This does not affect the log l 49 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is control 50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option. 51 option.
63 52
64 config CONSOLE_LOGLEVEL_QUIET 53 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)" 54 int "quiet console loglevel (1-15)"
66 range 1 15 55 range 1 15
67 default "4" 56 default "4"
68 help 57 help
69 loglevel to use when "quiet" is pass 58 loglevel to use when "quiet" is passed on the kernel commandline.
70 59
71 When "quiet" is passed on the kernel 60 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW pa 61 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CON 62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74 63
75 config MESSAGE_LOGLEVEL_DEFAULT 64 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)" 65 int "Default message log level (1-7)"
77 range 1 7 66 range 1 7
78 default "4" 67 default "4"
79 help 68 help
80 Default log level for printk stateme 69 Default log level for printk statements with no specified priority.
81 70
82 This was hard-coded to KERN_WARNING 71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely 72 that are auditing their logs closely may want to set it to a lower
84 priority. 73 priority.
85 74
86 Note: This does not affect what mess 75 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use logl 76 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL 77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89 78
90 config BOOT_PRINTK_DELAY 79 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message b 80 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && G 81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help 82 help
94 This build option allows you to read 83 This build option allows you to read kernel boot messages
95 by inserting a short delay after eac 84 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the ker 85 specified in milliseconds on the kernel command line,
97 using "boot_delay=N". 86 using "boot_delay=N".
98 87
99 It is likely that you would also nee 88 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value. 89 the "loops per jiffie" value.
101 See a previous boot log for the "lpj 90 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before 91 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adverse 92 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the firs 93 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOC 94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup condit 95 what it believes to be lockup conditions.
107 96
108 config DYNAMIC_DEBUG 97 config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support" 98 bool "Enable dynamic printk() support"
110 default n 99 default n
111 depends on PRINTK 100 depends on PRINTK
112 depends on (DEBUG_FS || PROC_FS) !! 101 depends on DEBUG_FS
113 select DYNAMIC_DEBUG_CORE <<
114 help 102 help
115 103
116 Compiles debug level messages into t 104 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 105 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 106 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 107 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 108 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 109 enlarges the kernel text size by about 2%.
122 110
123 If a source file is compiled with DE 111 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 112 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 113 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 114 turned on by many CONFIG_*DEBUG* options.
127 115
128 Usage: 116 Usage:
129 117
130 Dynamic debugging is controlled via 118 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' !! 119 which is contained in the 'debugfs' filesystem. Thus, the debugfs
132 Thus, the debugfs or procfs filesyst !! 120 filesystem must first be mounted before making use of this feature.
133 making use of this feature. <<
134 We refer the control file as: <debug 121 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 122 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 123 format for each line of the file is:
137 124
138 filename:lineno [module]functi 125 filename:lineno [module]function flags format
139 126
140 filename : source file of the debug 127 filename : source file of the debug statement
141 lineno : line number of the debug st 128 lineno : line number of the debug statement
142 module : module that contains the de 129 module : module that contains the debug statement
143 function : function that contains th 130 function : function that contains the debug statement
144 flags : '=p' means the line is turne 131 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb 132 format : the format used for the debug statement
146 133
147 From a live system: 134 From a live system:
148 135
149 nullarbor:~ # cat <debugfs>/dy 136 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 137 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 138 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 139 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 140 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 141
155 Example usage: 142 Example usage:
156 143
157 // enable the message at line 144 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 145 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 146 <debugfs>/dynamic_debug/control
160 147
161 // enable all the messages in 148 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 149 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 150 <debugfs>/dynamic_debug/control
164 151
165 // enable all the messages in 152 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 153 nullarbor:~ # echo -n 'module nfsd +p' >
167 154 <debugfs>/dynamic_debug/control
168 155
169 // enable all 12 messages in t 156 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 157 nullarbor:~ # echo -n 'func svc_process +p' >
171 158 <debugfs>/dynamic_debug/control
172 159
173 // disable all 12 messages in 160 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 161 nullarbor:~ # echo -n 'func svc_process -p' >
175 162 <debugfs>/dynamic_debug/control
176 163
177 See Documentation/admin-guide/dynami 164 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 165 information.
179 166
180 config DYNAMIC_DEBUG_CORE <<
181 bool "Enable core function of dynamic <<
182 depends on PRINTK <<
183 depends on (DEBUG_FS || PROC_FS) <<
184 help <<
185 Enable core functional support of dy <<
186 when you want to tie dynamic debug t <<
187 DYNAMIC_DEBUG_MODULE defined for eac <<
188 the case of embedded system where th <<
189 sensitive for people. <<
190 <<
191 config SYMBOLIC_ERRNAME 167 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in 168 bool "Support symbolic error names in printf"
193 default y if PRINTK 169 default y if PRINTK
194 help 170 help
195 If you say Y here, the kernel's prin 171 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error name 172 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kerne 173 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel 174 (about 3KB), but can make the kernel logs easier to read.
199 175
200 config DEBUG_BUGVERBOSE 176 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70 177 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE 178 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y 179 default y
204 help 180 help
205 Say Y here to make BUG() panics outp 181 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP a 182 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of 183 debugging but costs about 70-100K of memory.
208 184
209 endmenu # "printk and dmesg options" 185 endmenu # "printk and dmesg options"
210 186
211 config DEBUG_KERNEL <<
212 bool "Kernel debugging" <<
213 help <<
214 Say Y here if you are developing dri <<
215 identify kernel problems. <<
216 <<
217 config DEBUG_MISC <<
218 bool "Miscellaneous debug code" <<
219 default DEBUG_KERNEL <<
220 depends on DEBUG_KERNEL <<
221 help <<
222 Say Y here if you need to enable mis <<
223 be under a more specific debug optio <<
224 <<
225 menu "Compile-time checks and compiler options 187 menu "Compile-time checks and compiler options"
226 188
227 config DEBUG_INFO 189 config DEBUG_INFO
228 bool !! 190 bool "Compile the kernel with debug info"
>> 191 depends on DEBUG_KERNEL && !COMPILE_TEST
229 help 192 help
230 A kernel debug info option other tha !! 193 If you say Y here the resulting kernel image will include
231 in the "Debug information" choice be !! 194 debugging info resulting in a larger kernel image.
232 information will be generated for bu <<
233 <<
234 # Clang generates .uleb128 with label differen <<
235 # older binutils ports do not support when uti <<
236 # relaxation: https://sourceware.org/bugzilla/ <<
237 config AS_HAS_NON_CONST_ULEB128 <<
238 def_bool $(as-instr,.uleb128 .Lexpr_en <<
239 <<
240 choice <<
241 prompt "Debug information" <<
242 depends on DEBUG_KERNEL <<
243 help <<
244 Selecting something other than "None <<
245 that will include debugging info res <<
246 This adds debug symbols to the kerne 195 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 196 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 197 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
>> 198 Say Y here only if you plan to debug the kernel.
249 199
250 Choose which version of DWARF debug !! 200 If unsure, say N.
251 select "Toolchain default". <<
252 <<
253 config DEBUG_INFO_NONE <<
254 bool "Disable debug information" <<
255 help <<
256 Do not build the kernel with debuggi <<
257 result in a faster and smaller build <<
258 <<
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT <<
260 bool "Rely on the toolchain's implicit <<
261 select DEBUG_INFO <<
262 depends on !CC_IS_CLANG || AS_IS_LLVM <<
263 help <<
264 The implicit default version of DWAR <<
265 toolchain changes over time. <<
266 <<
267 This can break consumers of the debu <<
268 support newer revisions, and prevent <<
269 those should be less common scenario <<
270 <<
271 config DEBUG_INFO_DWARF4 <<
272 bool "Generate DWARF Version 4 debugin <<
273 select DEBUG_INFO <<
274 depends on !CC_IS_CLANG || AS_IS_LLVM <<
275 help <<
276 Generate DWARF v4 debug info. This r <<
277 if using clang without clang's integ <<
278 <<
279 If you have consumers of DWARF debug <<
280 newer revisions of DWARF, you may wi <<
281 config select this. <<
282 <<
283 config DEBUG_INFO_DWARF5 <<
284 bool "Generate DWARF Version 5 debugin <<
285 select DEBUG_INFO <<
286 depends on !ARCH_HAS_BROKEN_DWARF5 <<
287 depends on !CC_IS_CLANG || AS_IS_LLVM <<
288 help <<
289 Generate DWARF v5 debug info. Requir <<
290 5.0+ accepts the -gdwarf-5 flag but <<
291 draft features until 7.0), and gdb 8 <<
292 <<
293 Changes to the structure of debug in <<
294 15-18% savings in resulting image an <<
295 compared to DWARF Version 4. DWARF V <<
296 extensions such as accelerators for <<
297 for fission (.dwo/.dwp) files. Users <<
298 config if they rely on tooling that <<
299 support DWARF Version 5. <<
300 <<
301 endchoice # "Debug information" <<
302 <<
303 if DEBUG_INFO <<
304 201
305 config DEBUG_INFO_REDUCED 202 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 203 bool "Reduce debugging information"
>> 204 depends on DEBUG_INFO
307 help 205 help
308 If you say Y here gcc is instructed 206 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 207 information for structure types. This means that tools that
310 need full debugging information (lik 208 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 209 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 210 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 211 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 212 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 213 Only works with newer gcc versions.
316 214
317 choice <<
318 prompt "Compressed Debug information" <<
319 help <<
320 Compress the resulting debug info. R <<
321 but requires that consumers are able <<
322 <<
323 If unsure, choose DEBUG_INFO_COMPRES <<
324 <<
325 config DEBUG_INFO_COMPRESSED_NONE <<
326 bool "Don't compress debug information <<
327 help <<
328 Don't compress debug info sections. <<
329 <<
330 config DEBUG_INFO_COMPRESSED_ZLIB <<
331 bool "Compress debugging information w <<
332 depends on $(cc-option,-gz=zlib) <<
333 depends on $(ld-option,--compress-debu <<
334 help <<
335 Compress the debug information using <<
336 5.0+, binutils 2.26+, and zlib. <<
337 <<
338 Users of dpkg-deb via scripts/packag <<
339 size of their debug .deb packages wi <<
340 debug info being compressed with zli <<
341 recompressed with a different compre <<
342 preferable to setting $KDEB_COMPRESS <<
343 larger. <<
344 <<
345 config DEBUG_INFO_COMPRESSED_ZSTD <<
346 bool "Compress debugging information w <<
347 depends on $(cc-option,-gz=zstd) <<
348 depends on $(ld-option,--compress-debu <<
349 help <<
350 Compress the debug information using <<
351 compression than zlib, for about the <<
352 toolchain support. Requires GCC 13. <<
353 zstd. <<
354 <<
355 endchoice # "Compressed Debug information" <<
356 <<
357 config DEBUG_INFO_SPLIT 215 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 216 bool "Produce split debuginfo in .dwo files"
>> 217 depends on DEBUG_INFO
359 depends on $(cc-option,-gsplit-dwarf) 218 depends on $(cc-option,-gsplit-dwarf)
360 # RISC-V linker relaxation + -gsplit-d <<
361 # prior to 12.x: <<
362 # https://github.com/llvm/llvm-project <<
363 # https://gcc.gnu.org/bugzilla/show_bu <<
364 depends on !RISCV || GCC_VERSION >= 12 <<
365 help 219 help
366 Generate debug info into separate .d 220 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 221 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 222 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 223 files instead of multiple times in object files and executables.
370 In addition the debug information is 224 In addition the debug information is also compressed.
371 225
372 Requires recent gcc (4.7+) and recen 226 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 227 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 228 to know about the .dwo files and include them.
375 Incompatible with older versions of 229 Incompatible with older versions of ccache.
376 230
>> 231 config DEBUG_INFO_DWARF4
>> 232 bool "Generate dwarf4 debuginfo"
>> 233 depends on DEBUG_INFO
>> 234 depends on $(cc-option,-gdwarf-4)
>> 235 help
>> 236 Generate dwarf4 debug info. This requires recent versions
>> 237 of gcc and gdb. It makes the debug information larger.
>> 238 But it significantly improves the success of resolving
>> 239 variables in gdb on optimized code.
>> 240
377 config DEBUG_INFO_BTF 241 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 242 bool "Generate BTF typeinfo"
>> 243 depends on DEBUG_INFO
379 depends on !DEBUG_INFO_SPLIT && !DEBUG 244 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || C 245 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 246 help
386 Generate deduplicated BTF type infor 247 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 248 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 249 DWARF type info into equivalent deduplicated BTF type info.
389 250
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 251 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 252 bool "Provide GDB scripts for kernel debugging"
>> 253 depends on DEBUG_INFO
429 help 254 help
430 This creates the required links to G 255 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 256 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 257 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 258 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 259 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 260 for further details.
436 261
437 endif # DEBUG_INFO !! 262 config ENABLE_MUST_CHECK
>> 263 bool "Enable __must_check logic"
>> 264 default y
>> 265 help
>> 266 Enable the __must_check logic in the kernel build. Disable this to
>> 267 suppress the "warning: ignoring return value of 'foo', declared with
>> 268 attribute warn_unused_result" messages.
438 269
439 config FRAME_WARN 270 config FRAME_WARN
440 int "Warn for stack frames larger than !! 271 int "Warn for stack frames larger than (needs gcc 4.4)"
441 range 0 8192 272 range 0 8192
442 default 0 if KMSAN <<
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 273 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC !! 274 default 1280 if (!64BIT && PARISC)
445 default 1536 if (!64BIT && XTENSA) !! 275 default 1024 if (!64BIT && !PARISC)
446 default 1280 if KASAN && !64BIT <<
447 default 1024 if !64BIT <<
448 default 2048 if 64BIT 276 default 2048 if 64BIT
449 help 277 help
450 Tell the compiler to warn at build t !! 278 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 279 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 280 Setting it to 0 disables the warning.
>> 281 Requires gcc 4.4
453 282
454 config STRIP_ASM_SYMS 283 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 284 bool "Strip assembler-generated symbols during link"
456 default n 285 default n
457 help 286 help
458 Strip internal assembler-generated s 287 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 288 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 289 get_wchan() and suchlike.
461 290
462 config READABLE_ASM 291 config READABLE_ASM
463 bool "Generate readable assembler code 292 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 293 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC <<
466 help 294 help
467 Disable some compiler optimizations 295 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 296 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 297 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 298 sane.
471 299
472 config HEADERS_INSTALL 300 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 301 bool "Install uapi headers to usr/include"
474 depends on !UML 302 depends on !UML
475 help 303 help
476 This option will install uapi header 304 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 305 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 306 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 307 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 308 as uapi header sanity checks.
481 309
>> 310 config OPTIMIZE_INLINING
>> 311 def_bool y
>> 312 help
>> 313 This option determines if the kernel forces gcc to inline the functions
>> 314 developers have marked 'inline'. Doing so takes away freedom from gcc to
>> 315 do what it thinks is best, which is desirable for the gcc 3.x series of
>> 316 compilers. The gcc 4.x series have a rewritten inlining algorithm and
>> 317 enabling this option will generate a smaller kernel there. Hopefully
>> 318 this algorithm is so good that allowing gcc 4.x and above to make the
>> 319 decision will become the default in the future. Until then this option
>> 320 is there to test gcc for this.
>> 321
482 config DEBUG_SECTION_MISMATCH 322 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 323 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 324 help
486 The section mismatch analysis checks 325 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 326 references from one section to another section.
488 During linktime or runtime, some sec 327 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 328 any use of code/data previously in these sections would
490 most likely result in an oops. 329 most likely result in an oops.
491 In the code, functions and variables 330 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 331 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 332 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 333 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 334 kernel build, and enabling this option causes the following
496 additional step to occur: 335 additional step to occur:
497 - Add the option -fno-inline-functio 336 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 337 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 338 function, we would lose the section information and thus
500 the analysis would not catch the i 339 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 340 This option tells gcc to inline less (but it does result in
502 a larger kernel). 341 a larger kernel).
503 342
504 config SECTION_MISMATCH_WARN_ONLY 343 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 344 bool "Make section mismatch errors non-fatal"
506 default y 345 default y
507 help 346 help
508 If you say N here, the build process 347 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 348 section mismatch, instead of just throwing warnings.
510 349
511 If unsure, say Y. 350 If unsure, say Y.
512 351
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B <<
514 bool "Force all function address 64B a <<
515 depends on EXPERT && (X86_64 || ARM64 <<
516 select FUNCTION_ALIGNMENT_64B <<
517 help <<
518 There are cases that a commit from o <<
519 address alignment of other domains, <<
520 bump (regression or improvement). En <<
521 verify if the bump is caused by func <<
522 it will slightly increase the kernel <<
523 <<
524 It is mainly for debug and performan <<
525 <<
526 # 352 #
527 # Select this config option from the architect 353 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 354 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 355 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 356 #
531 config ARCH_WANT_FRAME_POINTERS 357 config ARCH_WANT_FRAME_POINTERS
532 bool 358 bool
533 359
534 config FRAME_POINTER 360 config FRAME_POINTER
535 bool "Compile the kernel with frame po 361 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 362 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 363 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 364 help
539 If you say Y here the resulting kern 365 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 366 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 367 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 368
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 369 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 370 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 371 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 372 default n
551 help 373 help
552 Validate frame pointer rules at comp !! 374 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 375 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 376 that runtime stack traces are more reliable.
554 377
555 For more information, see !! 378 This is also a prerequisite for generation of ORC unwind data, which
556 tools/objtool/Documentation/objtool. !! 379 is needed for CONFIG_UNWINDER_ORC.
557 <<
558 config NOINSTR_VALIDATION <<
559 bool <<
560 depends on HAVE_NOINSTR_VALIDATION && <<
561 select OBJTOOL <<
562 default y <<
563 380
564 config VMLINUX_MAP !! 381 For more information, see
565 bool "Generate vmlinux.map file when l !! 382 tools/objtool/Documentation/stack-validation.txt.
566 depends on EXPERT <<
567 help <<
568 Selecting this option will pass "-Ma <<
569 when linking vmlinux. That file can <<
570 and debugging magic section games, a <<
571 pieces of code get eliminated with <<
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION <<
573 383
574 config DEBUG_FORCE_WEAK_PER_CPU 384 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 385 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 386 depends on DEBUG_KERNEL
577 help 387 help
578 s390 and alpha require percpu variab 388 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 389 defined weak to work around addressing range issue which
580 puts the following two restrictions 390 puts the following two restrictions on percpu variable
581 definitions. 391 definitions.
582 392
583 1. percpu symbols must be unique whe 393 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 394 2. percpu variables can't be defined inside a function
585 395
586 To ensure that generic code follows 396 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 397 option forces all percpu variables to be defined as weak.
588 398
589 endmenu # "Compiler options" 399 endmenu # "Compiler options"
590 400
591 menu "Generic Kernel Debugging Instruments" 401 menu "Generic Kernel Debugging Instruments"
592 402
593 config MAGIC_SYSRQ 403 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 404 bool "Magic SysRq key"
595 depends on !UML 405 depends on !UML
596 help 406 help
597 If you say Y here, you will have som 407 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 408 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 409 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 410 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 411 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 412 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 413 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 414 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 415 Don't say Y unless you really know what this hack does.
606 416
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 417 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 418 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 419 depends on MAGIC_SYSRQ
610 default 0x1 420 default 0x1
611 help 421 help
612 Specifies which SysRq key functions 422 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 423 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 424 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 425
616 config MAGIC_SYSRQ_SERIAL 426 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 427 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 428 depends on MAGIC_SYSRQ
619 default y 429 default y
620 help 430 help
621 Many embedded boards have a disconne 431 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 432 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 433 This option allows you to decide whether you want to enable the
624 magic SysRq key. 434 magic SysRq key.
625 435
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE <<
627 string "Char sequence that enables mag <<
628 depends on MAGIC_SYSRQ_SERIAL <<
629 default "" <<
630 help <<
631 Specifies a sequence of characters t <<
632 SysRq on a serial console. <<
633 <<
634 If unsure, leave an empty string and <<
635 <<
636 config DEBUG_FS 436 config DEBUG_FS
637 bool "Debug Filesystem" 437 bool "Debug Filesystem"
638 help 438 help
639 debugfs is a virtual file system tha 439 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 440 debugging files into. Enable this option to be able to read and
641 write to these files. 441 write to these files.
642 442
643 For detailed documentation on the de 443 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 444 Documentation/filesystems/.
645 445
646 If unsure, say N. 446 If unsure, say N.
647 447
648 choice <<
649 prompt "Debugfs default access" <<
650 depends on DEBUG_FS <<
651 default DEBUG_FS_ALLOW_ALL <<
652 help <<
653 This selects the default access rest <<
654 It can be overridden with kernel com <<
655 debugfs=[on,no-mount,off]. The restr <<
656 and filesystem registration. <<
657 <<
658 config DEBUG_FS_ALLOW_ALL <<
659 bool "Access normal" <<
660 help <<
661 No restrictions apply. Both API and <<
662 is on. This is the normal default op <<
663 <<
664 config DEBUG_FS_DISALLOW_MOUNT <<
665 bool "Do not register debugfs as files <<
666 help <<
667 The API is open but filesystem is no <<
668 their work and read with debug tools <<
669 debugfs filesystem. <<
670 <<
671 config DEBUG_FS_ALLOW_NONE <<
672 bool "No access" <<
673 help <<
674 Access is off. Clients get -PERM whe <<
675 debugfs tree and debugfs is not regi <<
676 Client can then back-off or continue <<
677 <<
678 endchoice <<
679 <<
680 source "lib/Kconfig.kgdb" 448 source "lib/Kconfig.kgdb"
>> 449
681 source "lib/Kconfig.ubsan" 450 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" <<
683 451
684 endmenu 452 endmenu
685 453
686 menu "Networking Debugging" !! 454 config DEBUG_KERNEL
>> 455 bool "Kernel debugging"
>> 456 help
>> 457 Say Y here if you are developing drivers or trying to debug and
>> 458 identify kernel problems.
687 459
688 source "net/Kconfig.debug" !! 460 config DEBUG_MISC
>> 461 bool "Miscellaneous debug code"
>> 462 default DEBUG_KERNEL
>> 463 depends on DEBUG_KERNEL
>> 464 help
>> 465 Say Y here if you need to enable miscellaneous debug code that should
>> 466 be under a more specific debug option but isn't.
689 467
690 endmenu # "Networking Debugging" <<
691 468
692 menu "Memory Debugging" 469 menu "Memory Debugging"
693 470
694 source "mm/Kconfig.debug" 471 source "mm/Kconfig.debug"
695 472
696 config DEBUG_OBJECTS 473 config DEBUG_OBJECTS
697 bool "Debug object operations" 474 bool "Debug object operations"
698 depends on DEBUG_KERNEL 475 depends on DEBUG_KERNEL
699 help 476 help
700 If you say Y here, additional code w 477 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 478 kernel to track the life time of various objects and validate
702 the operations on those objects. 479 the operations on those objects.
703 480
704 config DEBUG_OBJECTS_SELFTEST 481 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 482 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 483 depends on DEBUG_OBJECTS
707 help 484 help
708 This enables the selftest of the obj 485 This enables the selftest of the object debug code.
709 486
710 config DEBUG_OBJECTS_FREE 487 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 488 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 489 depends on DEBUG_OBJECTS
713 help 490 help
714 This enables checks whether a k/v fr 491 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 492 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 493 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 494 much slower.
718 495
719 config DEBUG_OBJECTS_TIMERS 496 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 497 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 498 depends on DEBUG_OBJECTS
722 help 499 help
723 If you say Y here, additional code w 500 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 501 timer routines to track the life time of timer objects and
725 validate the timer operations. 502 validate the timer operations.
726 503
727 config DEBUG_OBJECTS_WORK 504 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 505 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 506 depends on DEBUG_OBJECTS
730 help 507 help
731 If you say Y here, additional code w 508 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 509 work queue routines to track the life time of work objects and
733 validate the work operations. 510 validate the work operations.
734 511
735 config DEBUG_OBJECTS_RCU_HEAD 512 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 513 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 514 depends on DEBUG_OBJECTS
738 help 515 help
739 Enable this to turn on debugging of 516 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 517
741 config DEBUG_OBJECTS_PERCPU_COUNTER 518 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 519 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 520 depends on DEBUG_OBJECTS
744 help 521 help
745 If you say Y here, additional code w 522 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 523 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 524 objects and validate the percpu counter operations.
748 525
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 526 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 527 int "debug_objects bootup default value (0-1)"
751 range 0 1 528 range 0 1
752 default "1" 529 default "1"
753 depends on DEBUG_OBJECTS 530 depends on DEBUG_OBJECTS
754 help 531 help
755 Debug objects boot parameter default 532 Debug objects boot parameter default value
756 533
757 config SHRINKER_DEBUG !! 534 config DEBUG_SLAB
758 bool "Enable shrinker debugging suppor !! 535 bool "Debug slab memory allocations"
759 depends on DEBUG_FS !! 536 depends on DEBUG_KERNEL && SLAB
>> 537 help
>> 538 Say Y here to have the kernel do limited verification on memory
>> 539 allocation as well as poisoning memory on free to catch use of freed
>> 540 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 541
>> 542 config SLUB_DEBUG_ON
>> 543 bool "SLUB debugging on by default"
>> 544 depends on SLUB && SLUB_DEBUG
>> 545 default n
>> 546 help
>> 547 Boot with debugging on by default. SLUB boots by default with
>> 548 the runtime debug capabilities switched off. Enabling this is
>> 549 equivalent to specifying the "slub_debug" parameter on boot.
>> 550 There is no support for more fine grained debug control like
>> 551 possible with slub_debug=xxx. SLUB debugging may be switched
>> 552 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 553 "slub_debug=-".
>> 554
>> 555 config SLUB_STATS
>> 556 default n
>> 557 bool "Enable SLUB performance statistics"
>> 558 depends on SLUB && SYSFS
>> 559 help
>> 560 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 561 order find ways to optimize the allocator. This should never be
>> 562 enabled for production use since keeping statistics slows down
>> 563 the allocator by a few percentage points. The slabinfo command
>> 564 supports the determination of the most active slabs to figure
>> 565 out which slabs are relevant to a particular load.
>> 566 Try running: slabinfo -DA
>> 567
>> 568 config HAVE_DEBUG_KMEMLEAK
>> 569 bool
>> 570
>> 571 config DEBUG_KMEMLEAK
>> 572 bool "Kernel memory leak detector"
>> 573 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 574 select DEBUG_FS
>> 575 select STACKTRACE if STACKTRACE_SUPPORT
>> 576 select KALLSYMS
>> 577 select CRC32
760 help 578 help
761 Say Y to enable the shrinker debugfs !! 579 Say Y here if you want to enable the memory leak
762 visibility into the kernel memory sh !! 580 detector. The memory allocation/freeing is traced in a way
763 Disable it to avoid an extra memory !! 581 similar to the Boehm's conservative garbage collector, the
>> 582 difference being that the orphan objects are not freed but
>> 583 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 584 feature will introduce an overhead to memory
>> 585 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 586 details.
>> 587
>> 588 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
>> 589 of finding leaks due to the slab objects poisoning.
>> 590
>> 591 In order to access the kmemleak file, debugfs needs to be
>> 592 mounted (usually at /sys/kernel/debug).
>> 593
>> 594 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
>> 595 int "Kmemleak memory pool size"
>> 596 depends on DEBUG_KMEMLEAK
>> 597 range 200 1000000
>> 598 default 16000
>> 599 help
>> 600 Kmemleak must track all the memory allocations to avoid
>> 601 reporting false positives. Since memory may be allocated or
>> 602 freed before kmemleak is fully initialised, use a static pool
>> 603 of metadata objects to track such callbacks. After kmemleak is
>> 604 fully initialised, this memory pool acts as an emergency one
>> 605 if slab allocations fail.
>> 606
>> 607 config DEBUG_KMEMLEAK_TEST
>> 608 tristate "Simple test for the kernel memory leak detector"
>> 609 depends on DEBUG_KMEMLEAK && m
>> 610 help
>> 611 This option enables a module that explicitly leaks memory.
>> 612
>> 613 If unsure, say N.
>> 614
>> 615 config DEBUG_KMEMLEAK_DEFAULT_OFF
>> 616 bool "Default kmemleak to off"
>> 617 depends on DEBUG_KMEMLEAK
>> 618 help
>> 619 Say Y here to disable kmemleak by default. It can then be enabled
>> 620 on the command line via kmemleak=on.
>> 621
>> 622 config DEBUG_KMEMLEAK_AUTO_SCAN
>> 623 bool "Enable kmemleak auto scan thread on boot up"
>> 624 default y
>> 625 depends on DEBUG_KMEMLEAK
>> 626 help
>> 627 Depending on the cpu, kmemleak scan may be cpu intensive and can
>> 628 stall user tasks at times. This option enables/disables automatic
>> 629 kmemleak scan at boot up.
>> 630
>> 631 Say N here to disable kmemleak auto scan thread to stop automatic
>> 632 scanning. Disabling this option disables automatic reporting of
>> 633 memory leaks.
>> 634
>> 635 If unsure, say Y.
764 636
765 config DEBUG_STACK_USAGE 637 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 638 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 639 depends on DEBUG_KERNEL && !IA64
768 help 640 help
769 Enables the display of the minimum a 641 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 642 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 <<
773 643
774 This option will slow down process c 644 This option will slow down process creation somewhat.
775 645
776 config SCHED_STACK_END_CHECK 646 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 647 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 648 depends on DEBUG_KERNEL
779 default n 649 default n
780 help 650 help
781 This option checks for a stack overr 651 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 652 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 653 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 654 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 655 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 656 is examined. The runtime overhead introduced is minimal.
787 657
788 config ARCH_HAS_DEBUG_VM_PGTABLE <<
789 bool <<
790 help <<
791 An architecture should select this w <<
792 build and run DEBUG_VM_PGTABLE. <<
793 <<
794 config DEBUG_VM_IRQSOFF <<
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 <<
797 config DEBUG_VM 658 config DEBUG_VM
798 bool "Debug VM" 659 bool "Debug VM"
799 depends on DEBUG_KERNEL 660 depends on DEBUG_KERNEL
800 help 661 help
801 Enable this to turn on extended chec 662 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 663 that may impact performance.
803 664
804 If unsure, say N. 665 If unsure, say N.
805 666
806 config DEBUG_VM_SHOOT_LAZIES !! 667 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 668 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 669 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE <<
820 help 670 help
821 Enable VM maple tree debugging infor !! 671 Enable this to turn on VMA caching debug information. Doing so
>> 672 can cause significant overhead, so only enable it in non-production
>> 673 environments.
822 674
823 If unsure, say N. 675 If unsure, say N.
824 676
825 config DEBUG_VM_RB 677 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 678 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 679 depends on DEBUG_VM
828 help 680 help
829 Enable VM red-black tree debugging i 681 Enable VM red-black tree debugging information and extra validations.
830 682
831 If unsure, say N. 683 If unsure, say N.
832 684
833 config DEBUG_VM_PGFLAGS 685 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 686 bool "Debug page-flags operations"
835 depends on DEBUG_VM 687 depends on DEBUG_VM
836 help 688 help
837 Enables extra validation on page fla 689 Enables extra validation on page flags operations.
838 690
839 If unsure, say N. 691 If unsure, say N.
840 692
841 config DEBUG_VM_PGTABLE <<
842 bool "Debug arch page table for semant <<
843 depends on MMU <<
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE <<
845 default y if DEBUG_VM <<
846 help <<
847 This option provides a debug method <<
848 architecture page table helper funct <<
849 verifying if they comply with expect <<
850 will help architecture code in makin <<
851 new additions of these helpers still <<
852 semantics of the generic MM. Platfor <<
853 this through ARCH_HAS_DEBUG_VM_PGTAB <<
854 <<
855 If unsure, say N. <<
856 <<
857 config ARCH_HAS_DEBUG_VIRTUAL 693 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 694 bool
859 695
860 config DEBUG_VIRTUAL 696 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 697 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 698 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 699 help
864 Enable some costly sanity checks in 700 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 701 catch mistakes with virt_to_page() and friends.
866 702
867 If unsure, say N. 703 If unsure, say N.
868 704
869 config DEBUG_NOMMU_REGIONS 705 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 706 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 707 depends on DEBUG_KERNEL && !MMU
872 help 708 help
873 This option causes the global tree o 709 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 710 regions to be regularly checked for invalid topology.
875 711
876 config DEBUG_MEMORY_INIT 712 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 713 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 714 default !EXPERT
879 help 715 help
880 Enable this for additional checks du 716 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 717 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 718 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 719 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 720 on the mminit_loglevel= command-line option.
885 721
886 If unsure, say Y 722 If unsure, say Y
887 723
888 config MEMORY_NOTIFIER_ERROR_INJECT 724 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 725 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 726 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 727 help
892 This option provides the ability to 728 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 729 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 730 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 731
896 If the notifier call chain should be 732 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 733 notified, write the error code to "actions/<notifier event>/error".
898 734
899 Example: Inject memory hotplug offli 735 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 736
901 # cd /sys/kernel/debug/notifier-erro 737 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 738 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 739 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 740 bash: echo: write error: Cannot allocate memory
905 741
906 To compile this code as a module, ch 742 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 743 be called memory-notifier-error-inject.
908 744
909 If unsure, say N. 745 If unsure, say N.
910 746
911 config DEBUG_PER_CPU_MAPS 747 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 748 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 749 depends on DEBUG_KERNEL
914 depends on SMP 750 depends on SMP
915 help 751 help
916 Say Y to verify that the per_cpu map 752 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 753 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 754 and decreases performance.
919 755
920 Say N if unsure. 756 Say N if unsure.
921 757
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 758 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 759 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 760 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A <<
946 select DEBUG_KMAP_LOCAL <<
947 help 761 help
948 This option enables additional error 762 This option enables additional error checking for high memory
949 systems. Disable for production sys 763 systems. Disable for production systems.
950 764
951 config HAVE_DEBUG_STACKOVERFLOW 765 config HAVE_DEBUG_STACKOVERFLOW
952 bool 766 bool
953 767
954 config DEBUG_STACKOVERFLOW 768 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 769 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 770 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help !! 771 ---help---
958 Say Y here if you want to check for 772 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 773 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 774 option will show detailed messages if free stack space drops
961 below a certain limit. 775 below a certain limit.
962 776
963 These kinds of bugs usually occur wh 777 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 778 kernel get too deep, especially when interrupts are
965 involved. 779 involved.
966 780
967 Use this in cases where you see appa 781 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 782 corruption, especially if it appears in 'struct thread_info'
969 783
970 If in doubt, say "N". 784 If in doubt, say "N".
971 785
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" 786 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" <<
1005 source "lib/Kconfig.kmsan" <<
1006 787
1007 endmenu # "Memory Debugging" 788 endmenu # "Memory Debugging"
1008 789
1009 config DEBUG_SHIRQ 790 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 791 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 792 depends on DEBUG_KERNEL
1012 help 793 help
1013 Enable this to generate a spurious !! 794 Enable this to generate a spurious interrupt as soon as a shared
1014 interrupt handler is deregistered ( !! 795 interrupt handler is registered, and just before one is deregistered.
1015 is currently disabled). Drivers nee !! 796 Drivers ought to be able to handle interrupts coming in at those
1016 don't and need to be caught. !! 797 points; some don't and need to be caught.
1017 798
1018 menu "Debug Oops, Lockups and Hangs" 799 menu "Debug Oops, Lockups and Hangs"
1019 800
1020 config PANIC_ON_OOPS 801 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 802 bool "Panic on Oops"
1022 help 803 help
1023 Say Y here to enable the kernel to 804 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 805 has the same effect as setting oops=panic on the kernel command
1025 line. 806 line.
1026 807
1027 This feature is useful to ensure th 808 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 809 anything erroneous after an oops which could result in data
1029 corruption or other issues. 810 corruption or other issues.
1030 811
1031 Say N if unsure. 812 Say N if unsure.
1032 813
1033 config PANIC_ON_OOPS_VALUE 814 config PANIC_ON_OOPS_VALUE
1034 int 815 int
1035 range 0 1 816 range 0 1
1036 default 0 if !PANIC_ON_OOPS 817 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 818 default 1 if PANIC_ON_OOPS
1038 819
1039 config PANIC_TIMEOUT 820 config PANIC_TIMEOUT
1040 int "panic timeout" 821 int "panic timeout"
1041 default 0 822 default 0
1042 help 823 help
1043 Set the timeout value (in seconds) !! 824 Set the timeout value (in seconds) until a reboot occurs when the
1044 the kernel panics. If n = 0, then w 825 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 826 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 827 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 828
1050 config LOCKUP_DETECTOR 829 config LOCKUP_DETECTOR
1051 bool 830 bool
1052 831
1053 config SOFTLOCKUP_DETECTOR 832 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 833 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 834 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 835 select LOCKUP_DETECTOR
1057 help 836 help
1058 Say Y here to enable the kernel to 837 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 838 soft lockups.
1060 839
1061 Softlockups are bugs that cause the 840 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 841 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 842 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 843 detection and the system will stay locked up.
1065 844
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 845 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 846 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 847 depends on SOFTLOCKUP_DETECTOR
1083 help 848 help
1084 Say Y here to enable the kernel to 849 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 850 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 851 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 852 sysctl), without giving other tasks a chance to run.
1088 853
1089 The panic can be used in combinatio 854 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 855 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 856 lockup has been detected. This feature is useful for
1092 high-availability systems that have 857 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 858 where a lockup must be resolved ASAP.
1094 859
1095 Say N if unsure. 860 Say N if unsure.
1096 861
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 862 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 863 int
>> 864 depends on SOFTLOCKUP_DETECTOR
>> 865 range 0 1
>> 866 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 867 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 868
>> 869 config HARDLOCKUP_DETECTOR_PERF
1098 bool 870 bool
1099 depends on SMP !! 871 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 872
1102 # 873 #
1103 # Global switch whether to build a hardlockup !! 874 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 875 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 876 #
1107 # s390: it reported many false positive !! 877 config HARDLOCKUP_CHECK_TIMESTAMP
>> 878 bool
>> 879
1108 # 880 #
1109 # sparc64: has a custom implementation !! 881 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 882 # lockup detector rather than the perf based detector.
1111 # 883 #
1112 config HARDLOCKUP_DETECTOR 884 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 885 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 886 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 887 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 888 select LOCKUP_DETECTOR
1120 !! 889 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
>> 890 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121 help 891 help
1122 Say Y here to enable the kernel to 892 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 893 hard lockups.
1124 894
1125 Hardlockups are bugs that cause the 895 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 896 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 897 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 898 and the system will stay locked up.
1129 899
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 900 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 901 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 902 depends on HARDLOCKUP_DETECTOR
1190 help 903 help
1191 Say Y here to enable the kernel to 904 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 905 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 906 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 907 using the watchdog_thresh sysctl).
1195 908
1196 Say N if unsure. 909 Say N if unsure.
1197 910
>> 911 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 912 int
>> 913 depends on HARDLOCKUP_DETECTOR
>> 914 range 0 1
>> 915 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 916 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 917
1198 config DETECT_HUNG_TASK 918 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 919 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 920 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 921 default SOFTLOCKUP_DETECTOR
1202 help 922 help
1203 Say Y here to enable the kernel to 923 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 924 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 925 uninterruptible "D" state indefinitely.
1206 926
1207 When a hung task is detected, the k 927 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 928 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 929 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 930 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 931 feature has negligible overhead.
1212 932
1213 config DEFAULT_HUNG_TASK_TIMEOUT 933 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 934 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 935 depends on DETECT_HUNG_TASK
1216 default 120 936 default 120
1217 help 937 help
1218 This option controls the default ti 938 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 939 to determine when a task has become non-responsive and should
1220 be considered hung. 940 be considered hung.
1221 941
1222 It can be adjusted at runtime via t 942 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 943 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 944 /proc/sys/kernel/hung_task_timeout_secs.
1225 945
1226 A timeout of 0 disables the check. 946 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 947 Keeping the default should be fine in most cases.
1228 948
1229 config BOOTPARAM_HUNG_TASK_PANIC 949 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 950 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 951 depends on DETECT_HUNG_TASK
1232 help 952 help
1233 Say Y here to enable the kernel to 953 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 954 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 955 in uninterruptible "D" state.
1236 956
1237 The panic can be used in combinatio 957 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 958 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 959 hung task has been detected. This feature is useful for
1240 high-availability systems that have 960 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 961 where a hung tasks must be resolved ASAP.
1242 962
1243 Say N if unsure. 963 Say N if unsure.
1244 964
>> 965 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 966 int
>> 967 depends on DETECT_HUNG_TASK
>> 968 range 0 1
>> 969 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 970 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 971
1245 config WQ_WATCHDOG 972 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 973 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 974 depends on DEBUG_KERNEL
1248 help 975 help
1249 Say Y here to enable stall detectio 976 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 977 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 978 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 979 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 980 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 981 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 982
1256 config WQ_CPU_INTENSIVE_REPORT <<
1257 bool "Report per-cpu work items which <<
1258 depends on DEBUG_KERNEL <<
1259 help <<
1260 Say Y here to enable reporting of c <<
1261 items that hog CPUs for longer than <<
1262 workqueue.cpu_intensive_thresh_us. <<
1263 detects and excludes them from conc <<
1264 them from stalling other per-cpu wo <<
1265 triggering may not necessarily indi <<
1266 triggering likely indicates that th <<
1267 to use an unbound workqueue. <<
1268 <<
1269 config TEST_LOCKUP <<
1270 tristate "Test module to generate loc <<
1271 depends on m <<
1272 help <<
1273 This builds the "test_lockup" modul <<
1274 that watchdogs and lockup detectors <<
1275 <<
1276 Depending on module parameters it c <<
1277 lockup, "hung task", or locking arb <<
1278 Also it could generate series of lo <<
1279 <<
1280 If unsure, say N. <<
1281 <<
1282 endmenu # "Debug lockups and hangs" 983 endmenu # "Debug lockups and hangs"
1283 984
1284 menu "Scheduler Debugging" 985 menu "Scheduler Debugging"
1285 986
1286 config SCHED_DEBUG 987 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 988 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 989 depends on DEBUG_KERNEL && PROC_FS
1289 default y 990 default y
1290 help 991 help
1291 If you say Y here, the /sys/kernel/ !! 992 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 993 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 994 option is minimal.
1294 995
1295 config SCHED_INFO 996 config SCHED_INFO
1296 bool 997 bool
1297 default n 998 default n
1298 999
1299 config SCHEDSTATS 1000 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1001 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1002 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1003 select SCHED_INFO
1303 help 1004 help
1304 If you say Y here, additional code 1005 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1006 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1007 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1008 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1009 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1010 application, you can say N to avoid the very slight overhead
1310 this adds. 1011 this adds.
1311 1012
1312 endmenu 1013 endmenu
1313 1014
1314 config DEBUG_TIMEKEEPING 1015 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1016 bool "Enable extra timekeeping sanity checking"
1316 help 1017 help
1317 This option will enable additional 1018 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1019 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1020 problems are suspected.
1320 1021
1321 This may include checks in the time 1022 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1023 option may have a (very small) performance impact to some
1323 workloads. 1024 workloads.
1324 1025
1325 If unsure, say N. 1026 If unsure, say N.
1326 1027
1327 config DEBUG_PREEMPT 1028 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1029 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION 1030 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
>> 1031 default y
1330 help 1032 help
1331 If you say Y here then the kernel w 1033 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1034 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1035 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1036 will detect preemption count underflows.
1335 1037
1336 This option has potential to introd <<
1337 depending on workload as it trigger <<
1338 this_cpu operation. It should only <<
1339 <<
1340 menu "Lock Debugging (spinlocks, mutexes, etc 1038 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1039
1342 config LOCK_DEBUGGING_SUPPORT 1040 config LOCK_DEBUGGING_SUPPORT
1343 bool 1041 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1042 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1043 default y
1346 1044
1347 config PROVE_LOCKING 1045 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1046 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1047 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1048 select LOCKDEP
1351 select DEBUG_SPINLOCK 1049 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1050 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1051 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1052 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1053 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1054 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE <<
1358 select TRACE_IRQFLAGS 1055 select TRACE_IRQFLAGS
1359 default n 1056 default n
1360 help 1057 help
1361 This feature enables the kernel to p 1058 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1059 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1060 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1061 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1062 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1063 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1064 deadlock.
1368 1065
1369 In short, this feature enables the k 1066 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1067 related deadlocks before they actually occur.
1371 1068
1372 The proof does not depend on how har 1069 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1070 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1071 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1072 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1073 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1074 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1075 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1076 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1077 makes the deadlock theoretically possible).
1381 1078
1382 If a deadlock is impossible (i.e. th 1079 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1080 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1081 kernel reports nothing.
1385 1082
1386 NOTE: this feature can also be enabl 1083 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1084 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1085 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1086 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1087 arbitrary combination of these separate locking variants.
1391 1088
1392 For more details, see Documentation/ 1089 For more details, see Documentation/locking/lockdep-design.rst.
1393 1090
1394 config PROVE_RAW_LOCK_NESTING <<
1395 bool "Enable raw_spinlock - spinlock <<
1396 depends on PROVE_LOCKING <<
1397 default n <<
1398 help <<
1399 Enable the raw_spinlock vs. spinlock <<
1400 that the lock nesting rules for PREE <<
1401 not violated. <<
1402 <<
1403 NOTE: There are known nesting proble <<
1404 option expect lockdep splats until t <<
1405 addressed which is work in progress. <<
1406 identify and analyze these problems. <<
1407 check permanently enabled once the m <<
1408 <<
1409 If unsure, select N. <<
1410 <<
1411 config LOCK_STAT 1091 config LOCK_STAT
1412 bool "Lock usage statistics" 1092 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1093 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1094 select LOCKDEP
1415 select DEBUG_SPINLOCK 1095 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1096 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1097 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1098 select DEBUG_LOCK_ALLOC
1419 default n 1099 default n
1420 help 1100 help
1421 This feature enables tracking lock c 1101 This feature enables tracking lock contention points
1422 1102
1423 For more details, see Documentation/ 1103 For more details, see Documentation/locking/lockstat.rst
1424 1104
1425 This also enables lock events requir 1105 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1106 subcommand of perf.
1427 If you want to use "perf lock", you 1107 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1108 CONFIG_EVENT_TRACING.
1429 1109
1430 CONFIG_LOCK_STAT defines "contended" 1110 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1111 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1112
1433 config DEBUG_RT_MUTEXES 1113 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1114 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1115 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1116 help
1437 This allows rt mutex semantics viola 1117 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1118 deadlocks (lockups) to be detected and reported automatically.
1439 1119
1440 config DEBUG_SPINLOCK 1120 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1121 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1122 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1123 select UNINLINE_SPIN_UNLOCK
1444 help 1124 help
1445 Say Y here and build SMP to catch m 1125 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1126 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1127 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1128 deadlocks are also debuggable.
1449 1129
1450 config DEBUG_MUTEXES 1130 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1131 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1132 depends on DEBUG_KERNEL
1453 help 1133 help
1454 This feature allows mutex semantics 1134 This feature allows mutex semantics violations to be detected and
1455 reported. 1135 reported.
1456 1136
1457 config DEBUG_WW_MUTEX_SLOWPATH 1137 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1138 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1139 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1140 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1141 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1142 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1143 help
1465 This feature enables slowpath testin 1144 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1145 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1146 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1147 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1148 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1149 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1150 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1151 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1152 you are a distro, do not.
1474 1153
1475 config DEBUG_RWSEMS 1154 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1155 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1156 depends on DEBUG_KERNEL
1478 help 1157 help
1479 This debugging feature allows misma 1158 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1159 and unlocks to be detected and reported.
1481 1160
1482 config DEBUG_LOCK_ALLOC 1161 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1162 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1163 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1164 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1165 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1166 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1167 select LOCKDEP
1489 help 1168 help
1490 This feature will check whether any 1169 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1170 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1171 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1172 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1173 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1174 held during task exit.
1496 1175
1497 config LOCKDEP 1176 config LOCKDEP
1498 bool 1177 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1178 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1179 select STACKTRACE
>> 1180 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1501 select KALLSYMS 1181 select KALLSYMS
1502 select KALLSYMS_ALL 1182 select KALLSYMS_ALL
1503 1183
1504 config LOCKDEP_SMALL 1184 config LOCKDEP_SMALL
1505 bool 1185 bool
1506 1186
1507 config LOCKDEP_BITS <<
1508 int "Bitsize for MAX_LOCKDEP_ENTRIES" <<
1509 depends on LOCKDEP && !LOCKDEP_SMALL <<
1510 range 10 30 <<
1511 default 15 <<
1512 help <<
1513 Try increasing this value if you hi <<
1514 <<
1515 config LOCKDEP_CHAINS_BITS <<
1516 int "Bitsize for MAX_LOCKDEP_CHAINS" <<
1517 depends on LOCKDEP && !LOCKDEP_SMALL <<
1518 range 10 30 <<
1519 default 16 <<
1520 help <<
1521 Try increasing this value if you hi <<
1522 <<
1523 config LOCKDEP_STACK_TRACE_BITS <<
1524 int "Bitsize for MAX_STACK_TRACE_ENTR <<
1525 depends on LOCKDEP && !LOCKDEP_SMALL <<
1526 range 10 30 <<
1527 default 19 <<
1528 help <<
1529 Try increasing this value if you hi <<
1530 <<
1531 config LOCKDEP_STACK_TRACE_HASH_BITS <<
1532 int "Bitsize for STACK_TRACE_HASH_SIZ <<
1533 depends on LOCKDEP && !LOCKDEP_SMALL <<
1534 range 10 30 <<
1535 default 14 <<
1536 help <<
1537 Try increasing this value if you ne <<
1538 <<
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS <<
1540 int "Bitsize for elements in circular <<
1541 depends on LOCKDEP <<
1542 range 10 30 <<
1543 default 12 <<
1544 help <<
1545 Try increasing this value if you hi <<
1546 <<
1547 config DEBUG_LOCKDEP 1187 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1188 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1189 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS <<
1551 help 1190 help
1552 If you say Y here, the lock depende 1191 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1192 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1193 of more runtime overhead.
1555 1194
1556 config DEBUG_ATOMIC_SLEEP 1195 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1196 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1197 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1198 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1199 depends on !ARCH_NO_PREEMPT
1561 help 1200 help
1562 If you say Y here, various routines 1201 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1202 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1203 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1204 sections, inside an interrupt, etc...
1566 1205
1567 config DEBUG_LOCKING_API_SELFTESTS 1206 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1207 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1208 depends on DEBUG_KERNEL
1570 help 1209 help
1571 Say Y here if you want the kernel t 1210 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1211 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1212 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1213 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1214 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1215 mutexes and rwsems.
1577 1216
1578 config LOCK_TORTURE_TEST 1217 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1218 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1219 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1220 select TORTURE_TEST
1582 help 1221 help
1583 This option provides a kernel modul 1222 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1223 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1224 after the fact on the running kernel to be tested, if desired.
1586 1225
1587 Say Y here if you want kernel locki 1226 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1227 to be built into the kernel.
1589 Say M if you want these torture tes 1228 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1229 Say N if you are unsure.
1591 1230
1592 config WW_MUTEX_SELFTEST 1231 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1232 tristate "Wait/wound mutex selftests"
1594 help 1233 help
1595 This option provides a kernel modul 1234 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1235 on the struct ww_mutex locking API.
1597 1236
1598 It is recommended to enable DEBUG_W 1237 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1238 with this test harness.
1600 1239
1601 Say M if you want these self tests 1240 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1241 Say N if you are unsure.
1603 1242
1604 config SCF_TORTURE_TEST <<
1605 tristate "torture tests for smp_call_ <<
1606 depends on DEBUG_KERNEL <<
1607 select TORTURE_TEST <<
1608 help <<
1609 This option provides a kernel modul <<
1610 on the smp_call_function() family o <<
1611 module may be built after the fact <<
1612 be tested, if desired. <<
1613 <<
1614 config CSD_LOCK_WAIT_DEBUG <<
1615 bool "Debugging for csd_lock_wait(), <<
1616 depends on DEBUG_KERNEL <<
1617 depends on 64BIT <<
1618 default n <<
1619 help <<
1620 This option enables debug prints wh <<
1621 to the smp_call_function*() IPI wra <<
1622 include the IPI handler function cu <<
1623 and relevant stack traces. <<
1624 <<
1625 config CSD_LOCK_WAIT_DEBUG_DEFAULT <<
1626 bool "Default csd_lock_wait() debuggi <<
1627 depends on CSD_LOCK_WAIT_DEBUG <<
1628 depends on 64BIT <<
1629 default n <<
1630 help <<
1631 This option causes the csdlock_debu <<
1632 default to 1 (basic debugging) inst <<
1633 <<
1634 endmenu # lock debugging 1243 endmenu # lock debugging
1635 1244
1636 config TRACE_IRQFLAGS 1245 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT <<
1638 bool 1246 bool
1639 help 1247 help
1640 Enables hooks to interrupt enabling 1248 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1249 either tracing or lock debugging.
1642 1250
1643 config TRACE_IRQFLAGS_NMI <<
1644 def_bool y <<
1645 depends on TRACE_IRQFLAGS <<
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT <<
1647 <<
1648 config NMI_CHECK_CPU <<
1649 bool "Debugging for CPUs failing to r <<
1650 depends on DEBUG_KERNEL <<
1651 depends on X86 <<
1652 default n <<
1653 help <<
1654 Enables debug prints when a CPU fai <<
1655 backtrace NMI. These prints provid <<
1656 might legitimately be failing to re <<
1657 is offline of if ignore_nmis is set <<
1658 <<
1659 config DEBUG_IRQFLAGS <<
1660 bool "Debug IRQ flag manipulation" <<
1661 help <<
1662 Enables checks for potentially unsa <<
1663 interrupts, such as calling raw_loc <<
1664 are enabled. <<
1665 <<
1666 config STACKTRACE 1251 config STACKTRACE
1667 bool "Stack backtrace support" 1252 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1253 depends on STACKTRACE_SUPPORT
1669 help 1254 help
1670 This option causes the kernel to cr 1255 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1256 every process, showing its current stack trace.
1672 It is also used by various kernel d 1257 It is also used by various kernel debugging features that require
1673 stack trace generation. 1258 stack trace generation.
1674 1259
1675 config WARN_ALL_UNSEEDED_RANDOM 1260 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1261 bool "Warn for all uses of unseeded randomness"
1677 default n 1262 default n
1678 help 1263 help
1679 Some parts of the kernel contain bu 1264 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1265 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1266 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1267 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1268 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1269 are going wrong, so that they might contact developers about fixing
1685 it. 1270 it.
1686 1271
1687 Unfortunately, on some models of so 1272 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1273 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1274 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1275 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1276 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1277 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1278 However, since users cannot do anything actionable to
1694 address this, by default this optio !! 1279 address this, by default the kernel will issue only a single
>> 1280 warning for the first use of unseeded randomness.
1695 1281
1696 Say Y here if you want to receive w 1282 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1283 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1284 those developers interested in improving the security of
1699 Linux kernels running on their arch 1285 Linux kernels running on their architecture (or
1700 subarchitecture). 1286 subarchitecture).
1701 1287
1702 config DEBUG_KOBJECT 1288 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1289 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1290 depends on DEBUG_KERNEL
1705 help 1291 help
1706 If you say Y here, some extra kobje 1292 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1293 to the syslog.
1708 1294
1709 config DEBUG_KOBJECT_RELEASE 1295 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1296 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1297 depends on DEBUG_OBJECTS_TIMERS
1712 help 1298 help
1713 kobjects are reference counted obje 1299 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1300 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1301 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1302 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1303 example of this would be a struct device which has just been
1718 unregistered. 1304 unregistered.
1719 1305
1720 However, some buggy drivers assume 1306 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1307 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1308 goes completely against the principles of a refcounted object.
1723 1309
1724 If you say Y here, the kernel will 1310 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1311 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1312 kind of kobject release bug.
1727 1313
1728 config HAVE_DEBUG_BUGVERBOSE 1314 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1315 bool
1730 1316
1731 menu "Debug kernel data structures" 1317 menu "Debug kernel data structures"
1732 1318
1733 config DEBUG_LIST 1319 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1320 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1321 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1322 help
1738 Enable this to turn on extended che !! 1323 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1324 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 1325
1745 If unsure, say N. 1326 If unsure, say N.
1746 1327
1747 config DEBUG_PLIST 1328 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1329 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1330 depends on DEBUG_KERNEL
1750 help 1331 help
1751 Enable this to turn on extended che 1332 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1333 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1334 list multiple times during each manipulation.
1754 1335
1755 If unsure, say N. 1336 If unsure, say N.
1756 1337
1757 config DEBUG_SG 1338 config DEBUG_SG
1758 bool "Debug SG table operations" 1339 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1340 depends on DEBUG_KERNEL
1760 help 1341 help
1761 Enable this to turn on checks on sc 1342 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1343 help find problems with drivers that do not properly initialize
1763 their sg tables. 1344 their sg tables.
1764 1345
1765 If unsure, say N. 1346 If unsure, say N.
1766 1347
1767 config DEBUG_NOTIFIERS 1348 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1349 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1350 depends on DEBUG_KERNEL
1770 help 1351 help
1771 Enable this to turn on sanity check 1352 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1353 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1354 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1355 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1356 performance, say N.
1776 1357
1777 config DEBUG_CLOSURES !! 1358 config BUG_ON_DATA_CORRUPTION
1778 bool "Debug closures (bcache async wi !! 1359 bool "Trigger a BUG when data corruption is detected"
1779 depends on CLOSURES !! 1360 select DEBUG_LIST
1780 select DEBUG_FS !! 1361 help
1781 help !! 1362 Select this option if the kernel should BUG when it encounters
1782 Keeps all active closures in a link !! 1363 data corruption in kernel memory structures when they get checked
1783 interface to list them, which makes !! 1364 for validity.
1784 operations that get stuck. <<
1785 1365
1786 config DEBUG_MAPLE_TREE !! 1366 If unsure, say N.
1787 bool "Debug maple trees" !! 1367
>> 1368 endmenu
>> 1369
>> 1370 config DEBUG_CREDENTIALS
>> 1371 bool "Debug credential management"
1788 depends on DEBUG_KERNEL 1372 depends on DEBUG_KERNEL
1789 help 1373 help
1790 Enable maple tree debugging informa !! 1374 Enable this to turn on some debug checking for credential
>> 1375 management. The additional code keeps track of the number of
>> 1376 pointers from task_structs to any given cred struct, and checks to
>> 1377 see that this number never exceeds the usage count of the cred
>> 1378 struct.
1791 1379
1792 If unsure, say N. !! 1380 Furthermore, if SELinux is enabled, this also checks that the
>> 1381 security pointer in the cred struct is never seen to be invalid.
1793 1382
1794 endmenu !! 1383 If unsure, say N.
1795 1384
1796 source "kernel/rcu/Kconfig.debug" 1385 source "kernel/rcu/Kconfig.debug"
1797 1386
1798 config DEBUG_WQ_FORCE_RR_CPU 1387 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1388 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1389 depends on DEBUG_KERNEL
1801 default n 1390 default n
1802 help 1391 help
1803 Workqueue used to implicitly guaran 1392 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1393 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1394 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1395 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1396 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1397 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1398 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1399 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1400 be impacted.
1812 1401
>> 1402 config DEBUG_BLOCK_EXT_DEVT
>> 1403 bool "Force extended block device numbers and spread them"
>> 1404 depends on DEBUG_KERNEL
>> 1405 depends on BLOCK
>> 1406 default n
>> 1407 help
>> 1408 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1409 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1410 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1411 is broken.
>> 1412
>> 1413 Conventionally, block device numbers are allocated from
>> 1414 predetermined contiguous area. However, extended block area
>> 1415 may introduce non-contiguous block device numbers. This
>> 1416 option forces most block device numbers to be allocated from
>> 1417 the extended space and spreads them to discover kernel or
>> 1418 userland code paths which assume predetermined contiguous
>> 1419 device number allocation.
>> 1420
>> 1421 Note that turning on this debug option shuffles all the
>> 1422 device numbers for all IDE and SCSI devices including libata
>> 1423 ones, so root partition specified using device number
>> 1424 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1425 Textual device names (root=/dev/sdXn) will continue to work.
>> 1426
>> 1427 Say N if you are unsure.
>> 1428
1813 config CPU_HOTPLUG_STATE_CONTROL 1429 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1430 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1431 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1432 depends on HOTPLUG_CPU
1817 default n 1433 default n
1818 help 1434 help
1819 Allows to write steps between "offl 1435 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1436 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1437 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1438 restarted at arbitrary points yet.
1823 1439
1824 Say N if your are unsure. 1440 Say N if your are unsure.
1825 1441
1826 config LATENCYTOP 1442 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1443 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1444 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1445 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1446 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P !! 1447 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1832 select KALLSYMS 1448 select KALLSYMS
1833 select KALLSYMS_ALL 1449 select KALLSYMS_ALL
1834 select STACKTRACE 1450 select STACKTRACE
1835 select SCHEDSTATS 1451 select SCHEDSTATS
>> 1452 select SCHED_DEBUG
1836 help 1453 help
1837 Enable this option if you want to u 1454 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1455 to find out which userspace is blocking on what kernel operations.
1839 1456
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" 1457 source "kernel/trace/Kconfig"
1851 1458
1852 config PROVIDE_OHCI1394_DMA_INIT 1459 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1460 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1461 depends on PCI && X86
1855 help 1462 help
1856 If you want to debug problems which 1463 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1464 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1465 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1466 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1467 specification which is now the standard for FireWire controllers.
1861 1468
1862 With remote DMA, you can monitor th 1469 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1470 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1471 Even controlling a kernel debugger is possible using remote DMA.
1865 1472
1866 Usage: 1473 Usage:
1867 1474
1868 If ohci1394_dma=early is used as bo 1475 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1476 all OHCI1394 controllers which are found in the PCI config space.
1870 1477
1871 As all changes to the FireWire bus 1478 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1479 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1480 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1481 the debugging host before booting the debug target for debugging.
1875 1482
1876 This code (~1k) is freed after boot 1483 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1484 in charge of the OHCI-1394 controllers should be used instead.
1878 1485
1879 See Documentation/core-api/debuggin !! 1486 See Documentation/debugging-via-ohci1394.txt for more information.
1880 1487
1881 source "samples/Kconfig" 1488 source "samples/Kconfig"
1882 1489
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1490 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1491 bool
1885 1492
1886 config STRICT_DEVMEM 1493 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1494 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1495 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED !! 1496 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1497 default y if PPC || X86 || ARM64
1891 help 1498 help
1892 If this option is disabled, you all 1499 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1500 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1501 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1502 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1503 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1504 use due to the cache aliasing requirements.
1898 1505
1899 If this option is switched on, and 1506 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1507 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1508 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1509 users of /dev/mem.
1903 1510
1904 If in doubt, say Y. 1511 If in doubt, say Y.
1905 1512
1906 config IO_STRICT_DEVMEM 1513 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1514 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1515 depends on STRICT_DEVMEM
1909 help 1516 help
1910 If this option is disabled, you all 1517 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1518 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1519 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1520 specific access can be used by people debugging kernel drivers.
1914 1521
1915 If this option is switched on, the 1522 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1523 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1524 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1525 if the driver using a given range cannot be disabled.
1919 1526
1920 If in doubt, say Y. 1527 If in doubt, say Y.
1921 1528
1922 menu "$(SRCARCH) Debugging" 1529 menu "$(SRCARCH) Debugging"
1923 1530
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1531 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1532
1926 endmenu 1533 endmenu
1927 1534
1928 menu "Kernel Testing and Coverage" 1535 menu "Kernel Testing and Coverage"
1929 1536
1930 source "lib/kunit/Kconfig" 1537 source "lib/kunit/Kconfig"
1931 1538
1932 config NOTIFIER_ERROR_INJECTION 1539 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1540 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1541 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1542 select DEBUG_FS
1936 help 1543 help
1937 This option provides the ability to 1544 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1545 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1546 handling of notifier call chain failures.
1940 1547
1941 Say N if unsure. 1548 Say N if unsure.
1942 1549
1943 config PM_NOTIFIER_ERROR_INJECT 1550 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1551 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1552 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1553 default m if PM_DEBUG
1947 help 1554 help
1948 This option provides the ability to 1555 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1556 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1557 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1558
1952 If the notifier call chain should b 1559 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1560 notified, write the error code to "actions/<notifier event>/error".
1954 1561
1955 Example: Inject PM suspend error (- 1562 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1563
1957 # cd /sys/kernel/debug/notifier-err 1564 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1565 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1566 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1567 bash: echo: write error: Cannot allocate memory
1961 1568
1962 To compile this code as a module, c 1569 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1570 be called pm-notifier-error-inject.
1964 1571
1965 If unsure, say N. 1572 If unsure, say N.
1966 1573
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1574 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1575 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1576 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1577 help
1971 This option provides the ability to 1578 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1579 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1580 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1581 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1582
1976 If the notifier call chain should b 1583 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1584 notified, write the error code to "actions/<notifier event>/error".
1978 1585
1979 To compile this code as a module, c 1586 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1587 be called of-reconfig-notifier-error-inject.
1981 1588
1982 If unsure, say N. 1589 If unsure, say N.
1983 1590
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1591 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1592 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1593 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1594 help
1988 This option provides the ability to 1595 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1596 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1597 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1598
1992 If the notifier call chain should b 1599 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1600 notified, write the error code to "actions/<notifier event>/error".
1994 1601
1995 Example: Inject netdevice mtu chang 1602 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1603
1997 # cd /sys/kernel/debug/notifier-err 1604 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1605 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1606 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1607 RTNETLINK answers: Invalid argument
2001 1608
2002 To compile this code as a module, c 1609 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1610 be called netdev-notifier-error-inject.
2004 1611
2005 If unsure, say N. 1612 If unsure, say N.
2006 1613
2007 config FUNCTION_ERROR_INJECTION 1614 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" !! 1615 def_bool y
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1616 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010 help <<
2011 Add fault injections into various f <<
2012 ALLOW_ERROR_INJECTION() in the kern <<
2013 value of these functions. This is u <<
2014 <<
2015 If unsure, say N <<
2016 1617
2017 config FAULT_INJECTION 1618 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1619 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1620 depends on DEBUG_KERNEL
2020 help 1621 help
2021 Provide fault-injection framework. 1622 Provide fault-injection framework.
2022 For more details, see Documentation 1623 For more details, see Documentation/fault-injection/.
2023 1624
2024 config FAILSLAB 1625 config FAILSLAB
2025 bool "Fault-injection capability for 1626 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1627 depends on FAULT_INJECTION
>> 1628 depends on SLAB || SLUB
2027 help 1629 help
2028 Provide fault-injection capability 1630 Provide fault-injection capability for kmalloc.
2029 1631
2030 config FAIL_PAGE_ALLOC 1632 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for !! 1633 bool "Fault-injection capabilitiy for alloc_pages()"
2032 depends on FAULT_INJECTION 1634 depends on FAULT_INJECTION
2033 help 1635 help
2034 Provide fault-injection capability 1636 Provide fault-injection capability for alloc_pages().
2035 1637
2036 config FAULT_INJECTION_USERCOPY <<
2037 bool "Fault injection capability for <<
2038 depends on FAULT_INJECTION <<
2039 help <<
2040 Provides fault-injection capability <<
2041 in usercopy functions (copy_from_us <<
2042 <<
2043 config FAIL_MAKE_REQUEST 1638 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1639 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1640 depends on FAULT_INJECTION && BLOCK
2046 help 1641 help
2047 Provide fault-injection capability 1642 Provide fault-injection capability for disk IO.
2048 1643
2049 config FAIL_IO_TIMEOUT 1644 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1645 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1646 depends on FAULT_INJECTION && BLOCK
2052 help 1647 help
2053 Provide fault-injection capability 1648 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1649 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1650 thus exercising the error handling.
2056 1651
2057 Only works with drivers that use th 1652 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1653 for others it wont do anything.
2059 1654
2060 config FAIL_FUTEX 1655 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1656 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1657 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1658 depends on FAULT_INJECTION && FUTEX
2064 help 1659 help
2065 Provide fault-injection capability 1660 Provide fault-injection capability for futexes.
2066 1661
2067 config FAULT_INJECTION_DEBUG_FS 1662 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1663 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1664 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1665 help
2071 Enable configuration of fault-injec 1666 Enable configuration of fault-injection capabilities via debugfs.
2072 1667
2073 config FAIL_FUNCTION 1668 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1669 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1670 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1671 help
2077 Provide function-based fault-inject 1672 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1673 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1674 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1675 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1676 error handling in various subsystems.
2082 1677
2083 config FAIL_MMC_REQUEST 1678 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1679 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1680 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1681 help
2087 Provide fault-injection capability 1682 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1683 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1684 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1685 and to test how the mmc host driver handles retries from
2091 the block device. 1686 the block device.
2092 1687
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 1688 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1689 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1690 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1691 depends on !X86_64
2115 select STACKTRACE 1692 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P !! 1693 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
2117 help 1694 help
2118 Provide stacktrace filter for fault 1695 Provide stacktrace filter for fault-injection capabilities
2119 1696
2120 config ARCH_HAS_KCOV 1697 config ARCH_HAS_KCOV
2121 bool 1698 bool
2122 help 1699 help
2123 An architecture should select this 1700 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 1701 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 1702 disabling instrumentation for some early boot code.
2126 1703
2127 config CC_HAS_SANCOV_TRACE_PC 1704 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 1705 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 1706
2130 1707
2131 config KCOV 1708 config KCOV
2132 bool "Code coverage for fuzzing" 1709 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 1710 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 1711 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 1712 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 1713 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK <<
2140 help 1714 help
2141 KCOV exposes kernel code coverage i 1715 KCOV exposes kernel code coverage information in a form suitable
2142 for coverage-guided fuzzing (random 1716 for coverage-guided fuzzing (randomized testing).
2143 1717
>> 1718 If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> 1719 different machines and across reboots. If you need stable PC values,
>> 1720 disable RANDOMIZE_BASE.
>> 1721
2144 For more details, see Documentation 1722 For more details, see Documentation/dev-tools/kcov.rst.
2145 1723
2146 config KCOV_ENABLE_COMPARISONS 1724 config KCOV_ENABLE_COMPARISONS
2147 bool "Enable comparison operands coll 1725 bool "Enable comparison operands collection by KCOV"
2148 depends on KCOV 1726 depends on KCOV
2149 depends on $(cc-option,-fsanitize-cov 1727 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150 help 1728 help
2151 KCOV also exposes operands of every 1729 KCOV also exposes operands of every comparison in the instrumented
2152 code along with operand sizes and P 1730 code along with operand sizes and PCs of the comparison instructions.
2153 These operands can be used by fuzzi 1731 These operands can be used by fuzzing engines to improve the quality
2154 of fuzzing coverage. 1732 of fuzzing coverage.
2155 1733
2156 config KCOV_INSTRUMENT_ALL 1734 config KCOV_INSTRUMENT_ALL
2157 bool "Instrument all code by default" 1735 bool "Instrument all code by default"
2158 depends on KCOV 1736 depends on KCOV
2159 default y 1737 default y
2160 help 1738 help
2161 If you are doing generic system cal 1739 If you are doing generic system call fuzzing (like e.g. syzkaller),
2162 then you will want to instrument th 1740 then you will want to instrument the whole kernel and you should
2163 say y here. If you are doing more t 1741 say y here. If you are doing more targeted fuzzing (like e.g.
2164 filesystem fuzzing with AFL) then y 1742 filesystem fuzzing with AFL) then you will want to enable coverage
2165 for more specific subsets of files, 1743 for more specific subsets of files, and should say n here.
2166 1744
2167 config KCOV_IRQ_AREA_SIZE <<
2168 hex "Size of interrupt coverage colle <<
2169 depends on KCOV <<
2170 default 0x40000 <<
2171 help <<
2172 KCOV uses preallocated per-cpu area <<
2173 soft interrupts. This specifies the <<
2174 number of unsigned long words. <<
2175 <<
2176 menuconfig RUNTIME_TESTING_MENU 1745 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 1746 bool "Runtime Testing"
2178 default y !! 1747 def_bool y
2179 1748
2180 if RUNTIME_TESTING_MENU 1749 if RUNTIME_TESTING_MENU
2181 1750
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 1751 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 1752 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 1753 depends on DEBUG_FS
2220 help 1754 help
2221 This module enables testing of the di 1755 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 1756 inducing system failures at predefined crash points.
2223 If you don't need it: say N 1757 If you don't need it: say N
2224 Choose M here to compile this code as 1758 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 1759 called lkdtm.
2226 1760
2227 Documentation on how to use the modul 1761 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 1762 Documentation/fault-injection/provoke-crashes.rst
2229 1763
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 1764 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 1765 tristate "Linked list sorting test"
2244 depends on KUNIT <<
2245 default KUNIT_ALL_TESTS <<
2246 help <<
2247 Enable this to turn on 'list_sort() <<
2248 executed only once during system bo <<
2249 or at module load time. <<
2250 <<
2251 If unsure, say N. <<
2252 <<
2253 config TEST_MIN_HEAP <<
2254 tristate "Min heap test" <<
2255 depends on DEBUG_KERNEL || m 1766 depends on DEBUG_KERNEL || m
2256 help 1767 help
2257 Enable this to turn on min heap fun !! 1768 Enable this to turn on 'list_sort()' function test. This test is
2258 executed only once during system bo 1769 executed only once during system boot (so affects only boot time),
2259 or at module load time. 1770 or at module load time.
2260 1771
2261 If unsure, say N. 1772 If unsure, say N.
2262 1773
2263 config TEST_SORT 1774 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 1775 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 1776 depends on DEBUG_KERNEL || m
2276 help 1777 help
2277 Enable this to turn on 'do_div()' f !! 1778 This option enables the self-test function of 'sort()' at boot,
2278 executed only once during system bo <<
2279 or at module load time. 1779 or at module load time.
2280 1780
2281 If unsure, say N. 1781 If unsure, say N.
2282 1782
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 1783 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 1784 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 1785 depends on DEBUG_KERNEL
2298 depends on KPROBES 1786 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 1787 help
2303 This option provides for testing ba 1788 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 1789 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 1790 verified for functionality.
2306 1791
2307 Say N if you are unsure. 1792 Say N if you are unsure.
2308 1793
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 1794 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 1795 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 1796 depends on DEBUG_KERNEL
2324 help 1797 help
2325 This option provides a kernel modul 1798 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 1799 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 1800 for distributions or general kernels, but only for kernel
2328 developers working on architecture 1801 developers working on architecture code.
2329 1802
2330 Note that if you want to also test 1803 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 1804 have to enable STACKTRACE as well.
2332 1805
2333 Say N if you are unsure. 1806 Say N if you are unsure.
2334 1807
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 1808 config RBTREE_TEST
2346 tristate "Red-Black tree test" 1809 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 1810 depends on DEBUG_KERNEL
2348 help 1811 help
2349 A benchmark measuring the performan 1812 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 1813 Also includes rbtree invariant checks.
2351 1814
2352 config REED_SOLOMON_TEST 1815 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 1816 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 1817 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 1818 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 1819 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 1820 select REED_SOLOMON_DEC16
2358 help 1821 help
2359 This option enables the self-test f 1822 This option enables the self-test function of rslib at boot,
2360 or at module load time. 1823 or at module load time.
2361 1824
2362 If unsure, say N. 1825 If unsure, say N.
2363 1826
2364 config INTERVAL_TREE_TEST 1827 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 1828 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 1829 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 1830 select INTERVAL_TREE
2368 help 1831 help
2369 A benchmark measuring the performan 1832 A benchmark measuring the performance of the interval tree library
2370 1833
2371 config PERCPU_TEST 1834 config PERCPU_TEST
2372 tristate "Per cpu operations test" 1835 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 1836 depends on m && DEBUG_KERNEL
2374 help 1837 help
2375 Enable this option to build test mo 1838 Enable this option to build test module which validates per-cpu
2376 operations. 1839 operations.
2377 1840
2378 If unsure, say N. 1841 If unsure, say N.
2379 1842
2380 config ATOMIC64_SELFTEST 1843 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 1844 tristate "Perform an atomic64_t self-test"
2382 help 1845 help
2383 Enable this option to test the atom 1846 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 1847 at module load time.
2385 1848
2386 If unsure, say N. 1849 If unsure, say N.
2387 1850
2388 config ASYNC_RAID6_TEST 1851 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 1852 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 1853 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 1854 select ASYNC_MEMCPY
2392 help !! 1855 ---help---
2393 This is a one-shot self test that p 1856 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 1857 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 1858 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 1859 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 1860 engine if one is available.
2398 1861
2399 If unsure, say N. 1862 If unsure, say N.
2400 1863
2401 config TEST_HEXDUMP 1864 config TEST_HEXDUMP
2402 tristate "Test functions located in t 1865 tristate "Test functions located in the hexdump module at runtime"
2403 1866
2404 config STRING_KUNIT_TEST !! 1867 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 1868 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 1869
2409 config STRING_HELPERS_KUNIT_TEST !! 1870 config TEST_STRSCPY
2410 tristate "KUnit test string helpers a !! 1871 tristate "Test strscpy*() family of functions at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 1872
2414 config TEST_KSTRTOX 1873 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 1874 tristate "Test kstrto*() family of functions at runtime"
2416 1875
2417 config TEST_PRINTF 1876 config TEST_PRINTF
2418 tristate "Test printf() family of fun 1877 tristate "Test printf() family of functions at runtime"
2419 1878
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 1879 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 1880 tristate "Test bitmap_*() family of functions at runtime"
2425 help 1881 help
2426 Enable this option to test the bitm 1882 Enable this option to test the bitmap functions at boot.
2427 1883
2428 If unsure, say N. 1884 If unsure, say N.
2429 1885
>> 1886 config TEST_BITFIELD
>> 1887 tristate "Test bitfield functions at runtime"
>> 1888 help
>> 1889 Enable this option to test the bitfield functions at boot.
>> 1890
>> 1891 If unsure, say N.
>> 1892
2430 config TEST_UUID 1893 config TEST_UUID
2431 tristate "Test functions located in t 1894 tristate "Test functions located in the uuid module at runtime"
2432 1895
2433 config TEST_XARRAY 1896 config TEST_XARRAY
2434 tristate "Test the XArray code at run 1897 tristate "Test the XArray code at runtime"
2435 1898
2436 config TEST_MAPLE_TREE !! 1899 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 1900 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 1901
2445 config TEST_RHASHTABLE 1902 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 1903 tristate "Perform selftest on resizable hash table"
2447 help 1904 help
2448 Enable this option to test the rhas 1905 Enable this option to test the rhashtable functions at boot.
2449 1906
2450 If unsure, say N. 1907 If unsure, say N.
2451 1908
>> 1909 config TEST_HASH
>> 1910 tristate "Perform selftest on hash functions"
>> 1911 help
>> 1912 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 1913 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 1914 hash functions on boot (or module load).
>> 1915
>> 1916 This is intended to help people writing architecture-specific
>> 1917 optimized versions. If unsure, say N.
>> 1918
2452 config TEST_IDA 1919 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 1920 tristate "Perform selftest on IDA functions"
2454 1921
2455 config TEST_PARMAN 1922 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 1923 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 1924 depends on PARMAN
2458 help 1925 help
2459 Enable this option to test priority 1926 Enable this option to test priority array manager on boot
2460 (or module load). 1927 (or module load).
2461 1928
2462 If unsure, say N. 1929 If unsure, say N.
2463 1930
2464 config TEST_IRQ_TIMINGS 1931 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 1932 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 1933 depends on IRQ_TIMINGS
2467 help 1934 help
2468 Enable this option to test the irq 1935 Enable this option to test the irq timings code on boot.
2469 1936
2470 If unsure, say N. 1937 If unsure, say N.
2471 1938
2472 config TEST_LKM 1939 config TEST_LKM
2473 tristate "Test module loading with 'h 1940 tristate "Test module loading with 'hello world' module"
2474 depends on m 1941 depends on m
2475 help 1942 help
2476 This builds the "test_module" modul 1943 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 1944 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 1945 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 1946 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 1947 and will not normally be loaded by the system unless explicitly
2481 requested by name. 1948 requested by name.
2482 1949
2483 If unsure, say N. 1950 If unsure, say N.
2484 1951
2485 config TEST_BITOPS <<
2486 tristate "Test module for compilation <<
2487 help <<
2488 This builds the "test_bitops" modul <<
2489 TEST_LKM module except that it does <<
2490 set/clear_bit macros and get_count_ <<
2491 no compiler warnings from C=1 spars <<
2492 compilations. It has no dependencie <<
2493 explicitly requested by name. for <<
2494 <<
2495 If unsure, say N. <<
2496 <<
2497 config TEST_VMALLOC 1952 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 1953 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 1954 default n
2500 depends on MMU 1955 depends on MMU
2501 depends on m 1956 depends on m
2502 help 1957 help
2503 This builds the "test_vmalloc" modu 1958 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 1959 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 1960 subsystem can be evaluated from performance and stability point
2506 of view. 1961 of view.
2507 1962
2508 If unsure, say N. 1963 If unsure, say N.
2509 1964
>> 1965 config TEST_USER_COPY
>> 1966 tristate "Test user/kernel boundary protections"
>> 1967 depends on m
>> 1968 help
>> 1969 This builds the "test_user_copy" module that runs sanity checks
>> 1970 on the copy_to/from_user infrastructure, making sure basic
>> 1971 user/kernel boundary testing is working. If it fails to load,
>> 1972 a regression has been detected in the user/kernel memory boundary
>> 1973 protections.
>> 1974
>> 1975 If unsure, say N.
>> 1976
2510 config TEST_BPF 1977 config TEST_BPF
2511 tristate "Test BPF filter functionali 1978 tristate "Test BPF filter functionality"
2512 depends on m && NET 1979 depends on m && NET
2513 help 1980 help
2514 This builds the "test_bpf" module t 1981 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 1982 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 1983 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 1984 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 1985 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 1986 verifier used by user space verifier testsuite.
2520 1987
2521 If unsure, say N. 1988 If unsure, say N.
2522 1989
2523 config TEST_BLACKHOLE_DEV 1990 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 1991 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 1992 depends on m && NET
2526 help 1993 help
2527 This builds the "test_blackhole_dev 1994 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 1995 data path through this blackhole netdev.
2529 1996
2530 If unsure, say N. 1997 If unsure, say N.
2531 1998
2532 config FIND_BIT_BENCHMARK 1999 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 2000 tristate "Test find_bit functions"
2534 help 2001 help
2535 This builds the "test_find_bit" mod 2002 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2003 functions performance.
2537 2004
2538 If unsure, say N. 2005 If unsure, say N.
2539 2006
2540 config TEST_FIRMWARE 2007 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2008 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2009 depends on FW_LOADER
2543 help 2010 help
2544 This builds the "test_firmware" mod 2011 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2012 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2013 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2014 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2015 userspace.
2549 2016
2550 If unsure, say N. 2017 If unsure, say N.
2551 2018
2552 config TEST_SYSCTL 2019 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2020 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2021 depends on PROC_SYSCTL
2555 help 2022 help
2556 This builds the "test_sysctl" modul 2023 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2024 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2025 production knobs which might alter system functionality.
2559 2026
2560 If unsure, say N. 2027 If unsure, say N.
2561 2028
2562 config BITFIELD_KUNIT <<
2563 tristate "KUnit test bitfield functio <<
2564 depends on KUNIT <<
2565 default KUNIT_ALL_TESTS <<
2566 help <<
2567 Enable this option to test the bitf <<
2568 <<
2569 KUnit tests run during boot and out <<
2570 in TAP format (http://testanything. <<
2571 running the KUnit test harness, and <<
2572 production build. <<
2573 <<
2574 For more information on KUnit and u <<
2575 to the KUnit documentation in Docum <<
2576 <<
2577 If unsure, say N. <<
2578 <<
2579 config CHECKSUM_KUNIT <<
2580 tristate "KUnit test checksum functio <<
2581 depends on KUNIT <<
2582 default KUNIT_ALL_TESTS <<
2583 help <<
2584 Enable this option to test the chec <<
2585 <<
2586 KUnit tests run during boot and out <<
2587 in TAP format (http://testanything. <<
2588 running the KUnit test harness, and <<
2589 production build. <<
2590 <<
2591 For more information on KUnit and u <<
2592 to the KUnit documentation in Docum <<
2593 <<
2594 If unsure, say N. <<
2595 <<
2596 config HASH_KUNIT_TEST <<
2597 tristate "KUnit Test for integer hash <<
2598 depends on KUNIT <<
2599 default KUNIT_ALL_TESTS <<
2600 help <<
2601 Enable this option to test the kern <<
2602 integer (<linux/hash.h>) hash funct <<
2603 <<
2604 KUnit tests run during boot and out <<
2605 in TAP format (https://testanything <<
2606 running the KUnit test harness, and <<
2607 production build. <<
2608 <<
2609 For more information on KUnit and u <<
2610 to the KUnit documentation in Docum <<
2611 <<
2612 This is intended to help people wri <<
2613 optimized versions. If unsure, say <<
2614 <<
2615 config RESOURCE_KUNIT_TEST <<
2616 tristate "KUnit test for resource API <<
2617 depends on KUNIT <<
2618 default KUNIT_ALL_TESTS <<
2619 help <<
2620 This builds the resource API unit t <<
2621 Tests the logic of API provided by <<
2622 For more information on KUnit and u <<
2623 to the KUnit documentation in Docum <<
2624 <<
2625 If unsure, say N. <<
2626 <<
2627 config SYSCTL_KUNIT_TEST 2029 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! !! 2030 tristate "KUnit test for sysctl"
2629 depends on KUNIT 2031 depends on KUNIT
2630 default KUNIT_ALL_TESTS <<
2631 help 2032 help
2632 This builds the proc sysctl unit te 2033 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2034 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2035 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2036 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2037
2637 If unsure, say N. 2038 If unsure, say N.
2638 2039
2639 config LIST_KUNIT_TEST 2040 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke !! 2041 tristate "KUnit Test for Kernel Linked-list structures"
2641 depends on KUNIT 2042 depends on KUNIT
2642 default KUNIT_ALL_TESTS <<
2643 help 2043 help
2644 This builds the linked list KUnit t 2044 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2045 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2046 and associated macros.
2647 2047
2648 KUnit tests run during boot and out 2048 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything !! 2049 in TAP format (http://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2050 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2051 production build.
2652 2052
2653 For more information on KUnit and u 2053 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2054 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2055
2656 If unsure, say N. 2056 If unsure, say N.
2657 2057
2658 config HASHTABLE_KUNIT_TEST <<
2659 tristate "KUnit Test for Kernel Hasht <<
2660 depends on KUNIT <<
2661 default KUNIT_ALL_TESTS <<
2662 help <<
2663 This builds the hashtable KUnit tes <<
2664 It tests the basic functionality of <<
2665 include/linux/hashtable.h. For more <<
2666 unit tests in general please refer <<
2667 in Documentation/dev-tools/kunit/. <<
2668 <<
2669 If unsure, say N. <<
2670 <<
2671 config LINEAR_RANGES_TEST <<
2672 tristate "KUnit test for linear_range <<
2673 depends on KUNIT <<
2674 select LINEAR_RANGES <<
2675 help <<
2676 This builds the linear_ranges unit <<
2677 Tests the linear_ranges logic corre <<
2678 For more information on KUnit and u <<
2679 to the KUnit documentation in Docum <<
2680 <<
2681 If unsure, say N. <<
2682 <<
2683 config CMDLINE_KUNIT_TEST <<
2684 tristate "KUnit test for cmdline API" <<
2685 depends on KUNIT <<
2686 default KUNIT_ALL_TESTS <<
2687 help <<
2688 This builds the cmdline API unit te <<
2689 Tests the logic of API provided by <<
2690 For more information on KUnit and u <<
2691 to the KUnit documentation in Docum <<
2692 <<
2693 If unsure, say N. <<
2694 <<
2695 config BITS_TEST <<
2696 tristate "KUnit test for bits.h" if ! <<
2697 depends on KUNIT <<
2698 default KUNIT_ALL_TESTS <<
2699 help <<
2700 This builds the bits unit test. <<
2701 Tests the logic of macros defined i <<
2702 For more information on KUnit and u <<
2703 to the KUnit documentation in Docum <<
2704 <<
2705 If unsure, say N. <<
2706 <<
2707 config SLUB_KUNIT_TEST <<
2708 tristate "KUnit test for SLUB cache e <<
2709 depends on SLUB_DEBUG && KUNIT <<
2710 default KUNIT_ALL_TESTS <<
2711 help <<
2712 This builds SLUB allocator unit tes <<
2713 Tests SLUB cache debugging function <<
2714 For more information on KUnit and u <<
2715 to the KUnit documentation in Docum <<
2716 <<
2717 If unsure, say N. <<
2718 <<
2719 config RATIONAL_KUNIT_TEST <<
2720 tristate "KUnit test for rational.c" <<
2721 depends on KUNIT && RATIONAL <<
2722 default KUNIT_ALL_TESTS <<
2723 help <<
2724 This builds the rational math unit <<
2725 For more information on KUnit and u <<
2726 to the KUnit documentation in Docum <<
2727 <<
2728 If unsure, say N. <<
2729 <<
2730 config MEMCPY_KUNIT_TEST <<
2731 tristate "Test memcpy(), memmove(), a <<
2732 depends on KUNIT <<
2733 default KUNIT_ALL_TESTS <<
2734 help <<
2735 Builds unit tests for memcpy(), mem <<
2736 For more information on KUnit and u <<
2737 to the KUnit documentation in Docum <<
2738 <<
2739 If unsure, say N. <<
2740 <<
2741 config IS_SIGNED_TYPE_KUNIT_TEST <<
2742 tristate "Test is_signed_type() macro <<
2743 depends on KUNIT <<
2744 default KUNIT_ALL_TESTS <<
2745 help <<
2746 Builds unit tests for the is_signed <<
2747 <<
2748 For more information on KUnit and u <<
2749 to the KUnit documentation in Docum <<
2750 <<
2751 If unsure, say N. <<
2752 <<
2753 config OVERFLOW_KUNIT_TEST <<
2754 tristate "Test check_*_overflow() fun <<
2755 depends on KUNIT <<
2756 default KUNIT_ALL_TESTS <<
2757 help <<
2758 Builds unit tests for the check_*_o <<
2759 related functions. <<
2760 <<
2761 For more information on KUnit and u <<
2762 to the KUnit documentation in Docum <<
2763 <<
2764 If unsure, say N. <<
2765 <<
2766 config STACKINIT_KUNIT_TEST <<
2767 tristate "Test level of stack variabl <<
2768 depends on KUNIT <<
2769 default KUNIT_ALL_TESTS <<
2770 help <<
2771 Test if the kernel is zero-initiali <<
2772 padding. Coverage is controlled by <<
2773 CONFIG_INIT_STACK_ALL_PATTERN, CONF <<
2774 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFI <<
2775 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYR <<
2776 <<
2777 config FORTIFY_KUNIT_TEST <<
2778 tristate "Test fortified str*() and m <<
2779 depends on KUNIT <<
2780 default KUNIT_ALL_TESTS <<
2781 help <<
2782 Builds unit tests for checking inte <<
2783 by the str*() and mem*() family of <<
2784 traps of FORTIFY_SOURCE, see LKDTM' <<
2785 <<
2786 config HW_BREAKPOINT_KUNIT_TEST <<
2787 bool "Test hw_breakpoint constraints <<
2788 depends on HAVE_HW_BREAKPOINT <<
2789 depends on KUNIT=y <<
2790 default KUNIT_ALL_TESTS <<
2791 help <<
2792 Tests for hw_breakpoint constraints <<
2793 <<
2794 If unsure, say N. <<
2795 <<
2796 config SIPHASH_KUNIT_TEST <<
2797 tristate "Perform selftest on siphash <<
2798 depends on KUNIT <<
2799 default KUNIT_ALL_TESTS <<
2800 help <<
2801 Enable this option to test the kern <<
2802 functions on boot (or module load). <<
2803 <<
2804 This is intended to help people wri <<
2805 optimized versions. If unsure, say <<
2806 <<
2807 config USERCOPY_KUNIT_TEST <<
2808 tristate "KUnit Test for user/kernel <<
2809 depends on KUNIT <<
2810 default KUNIT_ALL_TESTS <<
2811 help <<
2812 This builds the "usercopy_kunit" mo <<
2813 on the copy_to/from_user infrastruc <<
2814 user/kernel boundary testing is wor <<
2815 <<
2816 config TEST_UDELAY 2058 config TEST_UDELAY
2817 tristate "udelay test driver" 2059 tristate "udelay test driver"
2818 help 2060 help
2819 This builds the "udelay_test" modul 2061 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2062 that udelay() is working properly.
2821 2063
2822 If unsure, say N. 2064 If unsure, say N.
2823 2065
2824 config TEST_STATIC_KEYS 2066 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2067 tristate "Test static keys"
2826 depends on m 2068 depends on m
2827 help 2069 help
2828 Test the static key interfaces. 2070 Test the static key interfaces.
2829 2071
2830 If unsure, say N. 2072 If unsure, say N.
2831 2073
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 2074 config TEST_KMOD
2843 tristate "kmod stress tester" 2075 tristate "kmod stress tester"
2844 depends on m 2076 depends on m
2845 depends on NETDEVICES && NET_CORE && 2077 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2078 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 2079 select TEST_LKM
2849 select XFS_FS 2080 select XFS_FS
2850 select TUN 2081 select TUN
2851 select BTRFS_FS 2082 select BTRFS_FS
2852 help 2083 help
2853 Test the kernel's module loading me 2084 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2085 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2086 This test provides a series of tests against kmod.
2856 2087
2857 Although technically you can either 2088 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2089 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2090 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2091 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2092 module load requests, ultimately this could be fatal.
2862 2093
2863 To run tests run: 2094 To run tests run:
2864 2095
2865 tools/testing/selftests/kmod/kmod.s 2096 tools/testing/selftests/kmod/kmod.sh --help
2866 2097
2867 If unsure, say N. 2098 If unsure, say N.
2868 2099
2869 config TEST_DEBUG_VIRTUAL 2100 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2101 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2102 depends on DEBUG_VIRTUAL
2872 help 2103 help
2873 Test the kernel's ability to detect 2104 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2105 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2106 kernel's virtual address map.
2876 2107
2877 If unsure, say N. 2108 If unsure, say N.
2878 2109
2879 config TEST_MEMCAT_P 2110 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2111 tristate "Test memcat_p() helper function"
2881 help 2112 help
2882 Test the memcat_p() helper for corr 2113 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2114 pointer arrays together.
2884 2115
2885 If unsure, say N. 2116 If unsure, say N.
2886 2117
2887 config TEST_OBJAGG !! 2118 config TEST_LIVEPATCH
2888 tristate "Perform selftest on object !! 2119 tristate "Test livepatching"
2889 default n 2120 default n
2890 depends on OBJAGG !! 2121 depends on DYNAMIC_DEBUG
>> 2122 depends on LIVEPATCH
>> 2123 depends on m
2891 help 2124 help
2892 Enable this option to test object a !! 2125 Test kernel livepatching features for correctness. The tests will
2893 (or module load). !! 2126 load test modules that will be livepatched in various scenarios.
2894 2127
2895 config TEST_MEMINIT !! 2128 To run all the livepatching tests:
2896 tristate "Test heap/page initializati <<
2897 help <<
2898 Test if the kernel is zero-initiali <<
2899 This can be useful to test init_on_ <<
2900 2129
2901 If unsure, say N. !! 2130 make -C tools/testing/selftests TARGETS=livepatch run_tests
2902 2131
2903 config TEST_HMM !! 2132 Alternatively, individual tests may be invoked:
2904 tristate "Test HMM (Heterogeneous Mem <<
2905 depends on TRANSPARENT_HUGEPAGE <<
2906 depends on DEVICE_PRIVATE <<
2907 select HMM_MIRROR <<
2908 select MMU_NOTIFIER <<
2909 help <<
2910 This is a pseudo device driver sole <<
2911 Say M here if you want to build the <<
2912 Doing so will allow you to run tool <<
2913 2133
2914 If unsure, say N. !! 2134 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2135 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2136 tools/testing/selftests/livepatch/test-shadow-vars.sh
2915 2137
2916 config TEST_FREE_PAGES !! 2138 If unsure, say N.
2917 tristate "Test freeing pages" <<
2918 help <<
2919 Test that a memory leak does not oc <<
2920 freeing a block of pages and a spec <<
2921 Loading this module is safe if your <<
2922 If the bug is not fixed, it will le <<
2923 probably OOM your system. <<
2924 2139
2925 config TEST_FPU !! 2140 config TEST_OBJAGG
2926 tristate "Test floating point operati !! 2141 tristate "Perform selftest on object aggreration manager"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2142 default n
>> 2143 depends on OBJAGG
2928 help 2144 help
2929 Enable this option to add /sys/kern !! 2145 Enable this option to test object aggregation manager on boot
2930 which will trigger a sequence of fl !! 2146 (or module load).
2931 for self-testing floating point con <<
2932 kernel_fpu_begin(). <<
2933 2147
2934 If unsure, say N. <<
2935 2148
2936 config TEST_CLOCKSOURCE_WATCHDOG !! 2149 config TEST_STACKINIT
2937 tristate "Test clocksource watchdog i !! 2150 tristate "Test level of stack variable initialization"
2938 depends on CLOCKSOURCE_WATCHDOG <<
2939 help 2151 help
2940 Enable this option to create a kern !! 2152 Test if the kernel is zero-initializing stack variables and
2941 a test of the clocksource watchdog. !! 2153 padding. Coverage is controlled by compiler flags,
2942 via modprobe or insmod in which cas !! 2154 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2943 loaded, or it may be built in, in w !! 2155 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2944 shortly after boot. <<
2945 2156
2946 If unsure, say N. 2157 If unsure, say N.
2947 2158
2948 config TEST_OBJPOOL !! 2159 config TEST_MEMINIT
2949 tristate "Test module for correctness !! 2160 tristate "Test heap/page initialization"
2950 default n <<
2951 depends on m && DEBUG_KERNEL <<
2952 help 2161 help
2953 This builds the "test_objpool" modu !! 2162 Test if the kernel is zero-initializing heap and page allocations.
2954 correctness verification and concur !! 2163 This can be useful to test init_on_alloc and init_on_free features.
2955 allocation and reclamation. <<
2956 2164
2957 If unsure, say N. 2165 If unsure, say N.
2958 2166
2959 endif # RUNTIME_TESTING_MENU 2167 endif # RUNTIME_TESTING_MENU
2960 2168
2961 config ARCH_USE_MEMTEST <<
2962 bool <<
2963 help <<
2964 An architecture should select this <<
2965 during boot process. <<
2966 <<
2967 config MEMTEST 2169 config MEMTEST
2968 bool "Memtest" 2170 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST !! 2171 ---help---
2970 help <<
2971 This option adds a kernel parameter 2172 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. !! 2173 to be set.
2973 memtest=0, mean disabled; -- 2174 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2175 memtest=1, mean do 1 test pattern;
2975 ... 2176 ...
2976 memtest=17, mean do 17 test p 2177 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2178 If you are unsure how to answer this question, answer N.
2978 2179
2979 2180
2980 2181
2981 config HYPERV_TESTING 2182 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2183 bool "Microsoft Hyper-V driver testing"
2983 default n 2184 default n
2984 depends on HYPERV && DEBUG_FS 2185 depends on HYPERV && DEBUG_FS
2985 help 2186 help
2986 Select this option to enable Hyper- 2187 Select this option to enable Hyper-V vmbus testing.
2987 2188
2988 endmenu # "Kernel Testing and Coverage" 2189 endmenu # "Kernel Testing and Coverage"
2989 <<
2990 menu "Rust hacking" <<
2991 <<
2992 config RUST_DEBUG_ASSERTIONS <<
2993 bool "Debug assertions" <<
2994 depends on RUST <<
2995 help <<
2996 Enables rustc's `-Cdebug-assertions <<
2997 <<
2998 This flag lets you turn `cfg(debug_ <<
2999 compilation on or off. This can be <<
3000 code in development but not in prod <<
3001 the behavior of the standard librar <<
3002 <<
3003 Note that this will apply to all Ru <<
3004 <<
3005 If unsure, say N. <<
3006 <<
3007 config RUST_OVERFLOW_CHECKS <<
3008 bool "Overflow checks" <<
3009 default y <<
3010 depends on RUST <<
3011 help <<
3012 Enables rustc's `-Coverflow-checks` <<
3013 <<
3014 This flag allows you to control the <<
3015 overflow. When overflow-checks are <<
3016 on overflow. <<
3017 <<
3018 Note that this will apply to all Ru <<
3019 <<
3020 If unsure, say Y. <<
3021 <<
3022 config RUST_BUILD_ASSERT_ALLOW <<
3023 bool "Allow unoptimized build-time as <<
3024 depends on RUST <<
3025 help <<
3026 Controls how are `build_error!` and <<
3027 <<
3028 If calls to them exist in the binar <<
3029 or that the optimizer failed to ver <<
3030 <<
3031 This should not happen, thus by def <<
3032 as an escape hatch, you can choose <<
3033 and let the check be carried at run <<
3034 the check fails). <<
3035 <<
3036 If unsure, say N. <<
3037 <<
3038 config RUST_KERNEL_DOCTESTS <<
3039 bool "Doctests for the `kernel` crate <<
3040 depends on RUST && KUNIT=y <<
3041 default KUNIT_ALL_TESTS <<
3042 help <<
3043 This builds the documentation tests <<
3044 as KUnit tests. <<
3045 <<
3046 For more information on KUnit and u <<
3047 please refer to the KUnit documenta <<
3048 <<
3049 If unsure, say N. <<
3050 <<
3051 endmenu # "Rust" <<
3052 2190
3053 endmenu # Kernel hacking 2191 endmenu # Kernel hacking
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