1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 menu "Kernel hacking" 2 menu "Kernel hacking"
3 3
4 menu "printk and dmesg options" 4 menu "printk and dmesg options"
5 5
6 config PRINTK_TIME 6 config PRINTK_TIME
7 bool "Show timing information on print 7 bool "Show timing information on printks"
8 depends on PRINTK 8 depends on PRINTK
9 help 9 help
10 Selecting this option causes time st 10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output o 11 messages to be added to the output of the syslog() system
12 call and at the console. 12 call and at the console.
13 13
14 The timestamp is always recorded int 14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifi 15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp 16 be included, not that the timestamp is recorded.
17 17
18 The behavior is also controlled by t 18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documen 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
20 20
21 config PRINTK_CALLER 21 config PRINTK_CALLER
22 bool "Show caller information on print 22 bool "Show caller information on printks"
23 depends on PRINTK 23 depends on PRINTK
24 help 24 help
25 Selecting this option causes printk( 25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "proces 26 in task context) or a caller "processor id" (if not in task context)
27 to every message. 27 to every message.
28 28
29 This option is intended for environm 29 This option is intended for environments where multiple threads
30 concurrently call printk() for many 30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where thes 31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple 32 line which was divided into multiple lines due to race) came from.
33 33
34 Since toggling after boot makes the 34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the k 35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface. 36 sysfs interface.
37 37
38 config STACKTRACE_BUILD_ID <<
39 bool "Show build ID information in sta <<
40 depends on PRINTK <<
41 help <<
42 Selecting this option adds build ID <<
43 stacktraces printed with the printk <<
44 <<
45 This option is intended for distros <<
46 accessible but can be downloaded giv <<
47 kernel module where the function is <<
48 <<
49 config CONSOLE_LOGLEVEL_DEFAULT 38 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)" 39 int "Default console loglevel (1-15)"
51 range 1 15 40 range 1 15
52 default "7" 41 default "7"
53 help 42 help
54 Default loglevel to determine what w 43 Default loglevel to determine what will be printed on the console.
55 44
56 Setting a default here is equivalent 45 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> co 46 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well. 47 value is specified here as well.
59 48
60 Note: This does not affect the log l 49 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is control 50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option. 51 option.
63 52
64 config CONSOLE_LOGLEVEL_QUIET 53 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)" 54 int "quiet console loglevel (1-15)"
66 range 1 15 55 range 1 15
67 default "4" 56 default "4"
68 help 57 help
69 loglevel to use when "quiet" is pass 58 loglevel to use when "quiet" is passed on the kernel commandline.
70 59
71 When "quiet" is passed on the kernel 60 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW pa 61 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CON 62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74 63
75 config MESSAGE_LOGLEVEL_DEFAULT 64 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)" 65 int "Default message log level (1-7)"
77 range 1 7 66 range 1 7
78 default "4" 67 default "4"
79 help 68 help
80 Default log level for printk stateme 69 Default log level for printk statements with no specified priority.
81 70
82 This was hard-coded to KERN_WARNING 71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely 72 that are auditing their logs closely may want to set it to a lower
84 priority. 73 priority.
85 74
86 Note: This does not affect what mess 75 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use logl 76 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL 77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89 78
90 config BOOT_PRINTK_DELAY 79 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message b 80 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && G 81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help 82 help
94 This build option allows you to read 83 This build option allows you to read kernel boot messages
95 by inserting a short delay after eac 84 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the ker 85 specified in milliseconds on the kernel command line,
97 using "boot_delay=N". 86 using "boot_delay=N".
98 87
99 It is likely that you would also nee 88 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value. 89 the "loops per jiffie" value.
101 See a previous boot log for the "lpj 90 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before 91 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adverse 92 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the firs 93 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOC 94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup condit 95 what it believes to be lockup conditions.
107 96
108 config DYNAMIC_DEBUG 97 config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support" 98 bool "Enable dynamic printk() support"
110 default n 99 default n
111 depends on PRINTK 100 depends on PRINTK
112 depends on (DEBUG_FS || PROC_FS) 101 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE 102 select DYNAMIC_DEBUG_CORE
114 help 103 help
115 104
116 Compiles debug level messages into t 105 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 106 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 107 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 108 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 110 enlarges the kernel text size by about 2%.
122 111
123 If a source file is compiled with DE 112 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 113 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 114 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 115 turned on by many CONFIG_*DEBUG* options.
127 116
128 Usage: 117 Usage:
129 118
130 Dynamic debugging is controlled via 119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' 120 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesyst 121 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature. 122 making use of this feature.
134 We refer the control file as: <debug 123 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 124 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 125 format for each line of the file is:
137 126
138 filename:lineno [module]functi 127 filename:lineno [module]function flags format
139 128
140 filename : source file of the debug 129 filename : source file of the debug statement
141 lineno : line number of the debug st 130 lineno : line number of the debug statement
142 module : module that contains the de 131 module : module that contains the debug statement
143 function : function that contains th 132 function : function that contains the debug statement
144 flags : '=p' means the line is turne 133 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb 134 format : the format used for the debug statement
146 135
147 From a live system: 136 From a live system:
148 137
149 nullarbor:~ # cat <debugfs>/dy 138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 139 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 143
155 Example usage: 144 Example usage:
156 145
157 // enable the message at line 146 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 148 <debugfs>/dynamic_debug/control
160 149
161 // enable all the messages in 150 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 151 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 152 <debugfs>/dynamic_debug/control
164 153
165 // enable all the messages in 154 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 155 nullarbor:~ # echo -n 'module nfsd +p' >
167 156 <debugfs>/dynamic_debug/control
168 157
169 // enable all 12 messages in t 158 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 159 nullarbor:~ # echo -n 'func svc_process +p' >
171 160 <debugfs>/dynamic_debug/control
172 161
173 // disable all 12 messages in 162 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 163 nullarbor:~ # echo -n 'func svc_process -p' >
175 164 <debugfs>/dynamic_debug/control
176 165
177 See Documentation/admin-guide/dynami 166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 167 information.
179 168
180 config DYNAMIC_DEBUG_CORE 169 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic 170 bool "Enable core function of dynamic debug support"
182 depends on PRINTK 171 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS) 172 depends on (DEBUG_FS || PROC_FS)
184 help 173 help
185 Enable core functional support of dy 174 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug t 175 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for eac 176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where th 177 the case of embedded system where the kernel image size is
189 sensitive for people. 178 sensitive for people.
190 179
191 config SYMBOLIC_ERRNAME 180 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in 181 bool "Support symbolic error names in printf"
193 default y if PRINTK 182 default y if PRINTK
194 help 183 help
195 If you say Y here, the kernel's prin 184 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error name 185 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kerne 186 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel 187 (about 3KB), but can make the kernel logs easier to read.
199 188
200 config DEBUG_BUGVERBOSE 189 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70 190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE 191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y 192 default y
204 help 193 help
205 Say Y here to make BUG() panics outp 194 Say Y here to make BUG() panics output the file name and line number
206 of the BUG call as well as the EIP a 195 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of 196 debugging but costs about 70-100K of memory.
208 197
209 endmenu # "printk and dmesg options" 198 endmenu # "printk and dmesg options"
210 199
211 config DEBUG_KERNEL <<
212 bool "Kernel debugging" <<
213 help <<
214 Say Y here if you are developing dri <<
215 identify kernel problems. <<
216 <<
217 config DEBUG_MISC <<
218 bool "Miscellaneous debug code" <<
219 default DEBUG_KERNEL <<
220 depends on DEBUG_KERNEL <<
221 help <<
222 Say Y here if you need to enable mis <<
223 be under a more specific debug optio <<
224 <<
225 menu "Compile-time checks and compiler options 200 menu "Compile-time checks and compiler options"
226 201
227 config DEBUG_INFO 202 config DEBUG_INFO
228 bool !! 203 bool "Compile the kernel with debug info"
229 help !! 204 depends on DEBUG_KERNEL && !COMPILE_TEST
230 A kernel debug info option other tha <<
231 in the "Debug information" choice be <<
232 information will be generated for bu <<
233 <<
234 # Clang generates .uleb128 with label differen <<
235 # older binutils ports do not support when uti <<
236 # relaxation: https://sourceware.org/bugzilla/ <<
237 config AS_HAS_NON_CONST_ULEB128 <<
238 def_bool $(as-instr,.uleb128 .Lexpr_en <<
239 <<
240 choice <<
241 prompt "Debug information" <<
242 depends on DEBUG_KERNEL <<
243 help 205 help
244 Selecting something other than "None !! 206 If you say Y here the resulting kernel image will include
245 that will include debugging info res !! 207 debugging info resulting in a larger kernel image.
246 This adds debug symbols to the kerne 208 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 209 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
>> 211 Say Y here only if you plan to debug the kernel.
249 212
250 Choose which version of DWARF debug !! 213 If unsure, say N.
251 select "Toolchain default". <<
252 <<
253 config DEBUG_INFO_NONE <<
254 bool "Disable debug information" <<
255 help <<
256 Do not build the kernel with debuggi <<
257 result in a faster and smaller build <<
258 <<
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT <<
260 bool "Rely on the toolchain's implicit <<
261 select DEBUG_INFO <<
262 depends on !CC_IS_CLANG || AS_IS_LLVM <<
263 help <<
264 The implicit default version of DWAR <<
265 toolchain changes over time. <<
266 <<
267 This can break consumers of the debu <<
268 support newer revisions, and prevent <<
269 those should be less common scenario <<
270 <<
271 config DEBUG_INFO_DWARF4 <<
272 bool "Generate DWARF Version 4 debugin <<
273 select DEBUG_INFO <<
274 depends on !CC_IS_CLANG || AS_IS_LLVM <<
275 help <<
276 Generate DWARF v4 debug info. This r <<
277 if using clang without clang's integ <<
278 <<
279 If you have consumers of DWARF debug <<
280 newer revisions of DWARF, you may wi <<
281 config select this. <<
282 <<
283 config DEBUG_INFO_DWARF5 <<
284 bool "Generate DWARF Version 5 debugin <<
285 select DEBUG_INFO <<
286 depends on !ARCH_HAS_BROKEN_DWARF5 <<
287 depends on !CC_IS_CLANG || AS_IS_LLVM <<
288 help <<
289 Generate DWARF v5 debug info. Requir <<
290 5.0+ accepts the -gdwarf-5 flag but <<
291 draft features until 7.0), and gdb 8 <<
292 <<
293 Changes to the structure of debug in <<
294 15-18% savings in resulting image an <<
295 compared to DWARF Version 4. DWARF V <<
296 extensions such as accelerators for <<
297 for fission (.dwo/.dwp) files. Users <<
298 config if they rely on tooling that <<
299 support DWARF Version 5. <<
300 <<
301 endchoice # "Debug information" <<
302 214
303 if DEBUG_INFO 215 if DEBUG_INFO
304 216
305 config DEBUG_INFO_REDUCED 217 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 218 bool "Reduce debugging information"
307 help 219 help
308 If you say Y here gcc is instructed 220 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 221 information for structure types. This means that tools that
310 need full debugging information (lik 222 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 223 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 224 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 225 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 226 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 227 Only works with newer gcc versions.
316 228
317 choice !! 229 config DEBUG_INFO_COMPRESSED
318 prompt "Compressed Debug information" !! 230 bool "Compressed debugging information"
319 help <<
320 Compress the resulting debug info. R <<
321 but requires that consumers are able <<
322 <<
323 If unsure, choose DEBUG_INFO_COMPRES <<
324 <<
325 config DEBUG_INFO_COMPRESSED_NONE <<
326 bool "Don't compress debug information <<
327 help <<
328 Don't compress debug info sections. <<
329 <<
330 config DEBUG_INFO_COMPRESSED_ZLIB <<
331 bool "Compress debugging information w <<
332 depends on $(cc-option,-gz=zlib) 231 depends on $(cc-option,-gz=zlib)
333 depends on $(ld-option,--compress-debu 232 depends on $(ld-option,--compress-debug-sections=zlib)
334 help 233 help
335 Compress the debug information using 234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
336 5.0+, binutils 2.26+, and zlib. 235 5.0+, binutils 2.26+, and zlib.
337 236
338 Users of dpkg-deb via scripts/packag 237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
339 size of their debug .deb packages wi 238 size of their debug .deb packages with this config set, due to the
340 debug info being compressed with zli 239 debug info being compressed with zlib, then the object files being
341 recompressed with a different compre 240 recompressed with a different compression scheme. But this is still
342 preferable to setting $KDEB_COMPRESS 241 preferable to setting $KDEB_COMPRESS to "none" which would be even
343 larger. 242 larger.
344 243
345 config DEBUG_INFO_COMPRESSED_ZSTD <<
346 bool "Compress debugging information w <<
347 depends on $(cc-option,-gz=zstd) <<
348 depends on $(ld-option,--compress-debu <<
349 help <<
350 Compress the debug information using <<
351 compression than zlib, for about the <<
352 toolchain support. Requires GCC 13. <<
353 zstd. <<
354 <<
355 endchoice # "Compressed Debug information" <<
356 <<
357 config DEBUG_INFO_SPLIT 244 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 245 bool "Produce split debuginfo in .dwo files"
359 depends on $(cc-option,-gsplit-dwarf) 246 depends on $(cc-option,-gsplit-dwarf)
360 # RISC-V linker relaxation + -gsplit-d <<
361 # prior to 12.x: <<
362 # https://github.com/llvm/llvm-project <<
363 # https://gcc.gnu.org/bugzilla/show_bu <<
364 depends on !RISCV || GCC_VERSION >= 12 <<
365 help 247 help
366 Generate debug info into separate .d 248 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 249 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 250 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 251 files instead of multiple times in object files and executables.
370 In addition the debug information is 252 In addition the debug information is also compressed.
371 253
372 Requires recent gcc (4.7+) and recen 254 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 255 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 256 to know about the .dwo files and include them.
375 Incompatible with older versions of 257 Incompatible with older versions of ccache.
376 258
>> 259 config DEBUG_INFO_DWARF4
>> 260 bool "Generate dwarf4 debuginfo"
>> 261 depends on $(cc-option,-gdwarf-4)
>> 262 help
>> 263 Generate dwarf4 debug info. This requires recent versions
>> 264 of gcc and gdb. It makes the debug information larger.
>> 265 But it significantly improves the success of resolving
>> 266 variables in gdb on optimized code.
>> 267
377 config DEBUG_INFO_BTF 268 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 269 bool "Generate BTF typeinfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG 270 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || C 271 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
381 depends on BPF_SYSCALL <<
382 depends on !DEBUG_INFO_DWARF5 || PAHOL <<
383 # pahole uses elfutils, which does not <<
384 depends on !HEXAGON <<
385 help 272 help
386 Generate deduplicated BTF type infor 273 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 274 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 275 DWARF type info into equivalent deduplicated BTF type info.
389 276
390 config PAHOLE_HAS_SPLIT_BTF 277 config PAHOLE_HAS_SPLIT_BTF
391 def_bool PAHOLE_VERSION >= 119 !! 278 def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "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. <<
409 279
410 config DEBUG_INFO_BTF_MODULES 280 config DEBUG_INFO_BTF_MODULES
411 bool "Generate BTF type information fo !! 281 def_bool y
412 default y <<
413 depends on DEBUG_INFO_BTF && MODULES & 282 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
414 help 283 help
415 Generate compact split BTF type info 284 Generate compact split BTF type information for kernel modules.
416 285
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 286 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 287 bool "Provide GDB scripts for kernel debugging"
429 help 288 help
430 This creates the required links to G 289 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 290 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 291 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 292 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 293 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 294 for further details.
436 295
437 endif # DEBUG_INFO 296 endif # DEBUG_INFO
438 297
439 config FRAME_WARN 298 config FRAME_WARN
440 int "Warn for stack frames larger than 299 int "Warn for stack frames larger than"
441 range 0 8192 300 range 0 8192
442 default 0 if KMSAN <<
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 301 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC !! 302 default 1280 if (!64BIT && PARISC)
445 default 1536 if (!64BIT && XTENSA) !! 303 default 1024 if (!64BIT && !PARISC)
446 default 1280 if KASAN && !64BIT <<
447 default 1024 if !64BIT <<
448 default 2048 if 64BIT 304 default 2048 if 64BIT
449 help 305 help
450 Tell the compiler to warn at build t !! 306 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 307 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 308 Setting it to 0 disables the warning.
453 309
454 config STRIP_ASM_SYMS 310 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 311 bool "Strip assembler-generated symbols during link"
456 default n 312 default n
457 help 313 help
458 Strip internal assembler-generated s 314 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 315 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 316 get_wchan() and suchlike.
461 317
462 config READABLE_ASM 318 config READABLE_ASM
463 bool "Generate readable assembler code 319 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 320 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC <<
466 help 321 help
467 Disable some compiler optimizations 322 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 323 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 324 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 325 sane.
471 326
472 config HEADERS_INSTALL 327 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 328 bool "Install uapi headers to usr/include"
474 depends on !UML 329 depends on !UML
475 help 330 help
476 This option will install uapi header 331 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 332 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 333 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 334 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 335 as uapi header sanity checks.
481 336
482 config DEBUG_SECTION_MISMATCH 337 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 338 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 339 help
486 The section mismatch analysis checks 340 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 341 references from one section to another section.
488 During linktime or runtime, some sec 342 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 343 any use of code/data previously in these sections would
490 most likely result in an oops. 344 most likely result in an oops.
491 In the code, functions and variables 345 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 346 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 347 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 348 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 349 kernel build, and enabling this option causes the following
496 additional step to occur: 350 additional step to occur:
497 - Add the option -fno-inline-functio 351 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 352 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 353 function, we would lose the section information and thus
500 the analysis would not catch the i 354 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 355 This option tells gcc to inline less (but it does result in
502 a larger kernel). 356 a larger kernel).
503 357
504 config SECTION_MISMATCH_WARN_ONLY 358 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 359 bool "Make section mismatch errors non-fatal"
506 default y 360 default y
507 help 361 help
508 If you say N here, the build process 362 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 363 section mismatch, instead of just throwing warnings.
510 364
511 If unsure, say Y. 365 If unsure, say Y.
512 366
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B !! 367 config DEBUG_FORCE_FUNCTION_ALIGN_32B
514 bool "Force all function address 64B a !! 368 bool "Force all function address 32B aligned" if EXPERT
515 depends on EXPERT && (X86_64 || ARM64 <<
516 select FUNCTION_ALIGNMENT_64B <<
517 help 369 help
518 There are cases that a commit from o 370 There are cases that a commit from one domain changes the function
519 address alignment of other domains, 371 address alignment of other domains, and cause magic performance
520 bump (regression or improvement). En 372 bump (regression or improvement). Enable this option will help to
521 verify if the bump is caused by func 373 verify if the bump is caused by function alignment changes, while
522 it will slightly increase the kernel 374 it will slightly increase the kernel size and affect icache usage.
523 375
524 It is mainly for debug and performan 376 It is mainly for debug and performance tuning use.
525 377
526 # 378 #
527 # Select this config option from the architect 379 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 380 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 381 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 382 #
531 config ARCH_WANT_FRAME_POINTERS 383 config ARCH_WANT_FRAME_POINTERS
532 bool 384 bool
533 385
534 config FRAME_POINTER 386 config FRAME_POINTER
535 bool "Compile the kernel with frame po 387 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 388 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 389 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 390 help
539 If you say Y here the resulting kern 391 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 392 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 393 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 394
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 395 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 396 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 397 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 398 default n
551 help 399 help
552 Validate frame pointer rules at comp !! 400 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 401 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 402 that runtime stack traces are more reliable.
>> 403
>> 404 This is also a prerequisite for generation of ORC unwind data, which
>> 405 is needed for CONFIG_UNWINDER_ORC.
554 406
555 For more information, see 407 For more information, see
556 tools/objtool/Documentation/objtool. !! 408 tools/objtool/Documentation/stack-validation.txt.
557 409
558 config NOINSTR_VALIDATION !! 410 config VMLINUX_VALIDATION
559 bool 411 bool
560 depends on HAVE_NOINSTR_VALIDATION && !! 412 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
561 select OBJTOOL <<
562 default y 413 default y
563 414
564 config VMLINUX_MAP <<
565 bool "Generate vmlinux.map file when l <<
566 depends on EXPERT <<
567 help <<
568 Selecting this option will pass "-Ma <<
569 when linking vmlinux. That file can <<
570 and debugging magic section games, a <<
571 pieces of code get eliminated with <<
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION <<
573 <<
574 config DEBUG_FORCE_WEAK_PER_CPU 415 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 416 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 417 depends on DEBUG_KERNEL
577 help 418 help
578 s390 and alpha require percpu variab 419 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 420 defined weak to work around addressing range issue which
580 puts the following two restrictions 421 puts the following two restrictions on percpu variable
581 definitions. 422 definitions.
582 423
583 1. percpu symbols must be unique whe 424 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 425 2. percpu variables can't be defined inside a function
585 426
586 To ensure that generic code follows 427 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 428 option forces all percpu variables to be defined as weak.
588 429
589 endmenu # "Compiler options" 430 endmenu # "Compiler options"
590 431
591 menu "Generic Kernel Debugging Instruments" 432 menu "Generic Kernel Debugging Instruments"
592 433
593 config MAGIC_SYSRQ 434 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 435 bool "Magic SysRq key"
595 depends on !UML 436 depends on !UML
596 help 437 help
597 If you say Y here, you will have som 438 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 439 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 440 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 441 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 442 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 443 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 444 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 445 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 446 Don't say Y unless you really know what this hack does.
606 447
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 448 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 449 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 450 depends on MAGIC_SYSRQ
610 default 0x1 451 default 0x1
611 help 452 help
612 Specifies which SysRq key functions 453 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 454 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 455 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 456
616 config MAGIC_SYSRQ_SERIAL 457 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 458 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 459 depends on MAGIC_SYSRQ
619 default y 460 default y
620 help 461 help
621 Many embedded boards have a disconne 462 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 463 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 464 This option allows you to decide whether you want to enable the
624 magic SysRq key. 465 magic SysRq key.
625 466
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE 467 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627 string "Char sequence that enables mag 468 string "Char sequence that enables magic SysRq over serial"
628 depends on MAGIC_SYSRQ_SERIAL 469 depends on MAGIC_SYSRQ_SERIAL
629 default "" 470 default ""
630 help 471 help
631 Specifies a sequence of characters t 472 Specifies a sequence of characters that can follow BREAK to enable
632 SysRq on a serial console. 473 SysRq on a serial console.
633 474
634 If unsure, leave an empty string and 475 If unsure, leave an empty string and the option will not be enabled.
635 476
636 config DEBUG_FS 477 config DEBUG_FS
637 bool "Debug Filesystem" 478 bool "Debug Filesystem"
638 help 479 help
639 debugfs is a virtual file system tha 480 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 481 debugging files into. Enable this option to be able to read and
641 write to these files. 482 write to these files.
642 483
643 For detailed documentation on the de 484 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 485 Documentation/filesystems/.
645 486
646 If unsure, say N. 487 If unsure, say N.
647 488
648 choice 489 choice
649 prompt "Debugfs default access" 490 prompt "Debugfs default access"
650 depends on DEBUG_FS 491 depends on DEBUG_FS
651 default DEBUG_FS_ALLOW_ALL 492 default DEBUG_FS_ALLOW_ALL
652 help 493 help
653 This selects the default access rest 494 This selects the default access restrictions for debugfs.
654 It can be overridden with kernel com 495 It can be overridden with kernel command line option
655 debugfs=[on,no-mount,off]. The restr 496 debugfs=[on,no-mount,off]. The restrictions apply for API access
656 and filesystem registration. 497 and filesystem registration.
657 498
658 config DEBUG_FS_ALLOW_ALL 499 config DEBUG_FS_ALLOW_ALL
659 bool "Access normal" 500 bool "Access normal"
660 help 501 help
661 No restrictions apply. Both API and 502 No restrictions apply. Both API and filesystem registration
662 is on. This is the normal default op 503 is on. This is the normal default operation.
663 504
664 config DEBUG_FS_DISALLOW_MOUNT 505 config DEBUG_FS_DISALLOW_MOUNT
665 bool "Do not register debugfs as files 506 bool "Do not register debugfs as filesystem"
666 help 507 help
667 The API is open but filesystem is no 508 The API is open but filesystem is not loaded. Clients can still do
668 their work and read with debug tools 509 their work and read with debug tools that do not need
669 debugfs filesystem. 510 debugfs filesystem.
670 511
671 config DEBUG_FS_ALLOW_NONE 512 config DEBUG_FS_ALLOW_NONE
672 bool "No access" 513 bool "No access"
673 help 514 help
674 Access is off. Clients get -PERM whe 515 Access is off. Clients get -PERM when trying to create nodes in
675 debugfs tree and debugfs is not regi 516 debugfs tree and debugfs is not registered as a filesystem.
676 Client can then back-off or continue 517 Client can then back-off or continue without debugfs access.
677 518
678 endchoice 519 endchoice
679 520
680 source "lib/Kconfig.kgdb" 521 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan" 522 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" 523 source "lib/Kconfig.kcsan"
683 524
684 endmenu 525 endmenu
685 526
686 menu "Networking Debugging" !! 527 config DEBUG_KERNEL
>> 528 bool "Kernel debugging"
>> 529 help
>> 530 Say Y here if you are developing drivers or trying to debug and
>> 531 identify kernel problems.
687 532
688 source "net/Kconfig.debug" !! 533 config DEBUG_MISC
>> 534 bool "Miscellaneous debug code"
>> 535 default DEBUG_KERNEL
>> 536 depends on DEBUG_KERNEL
>> 537 help
>> 538 Say Y here if you need to enable miscellaneous debug code that should
>> 539 be under a more specific debug option but isn't.
689 540
690 endmenu # "Networking Debugging" <<
691 541
692 menu "Memory Debugging" 542 menu "Memory Debugging"
693 543
694 source "mm/Kconfig.debug" 544 source "mm/Kconfig.debug"
695 545
696 config DEBUG_OBJECTS 546 config DEBUG_OBJECTS
697 bool "Debug object operations" 547 bool "Debug object operations"
698 depends on DEBUG_KERNEL 548 depends on DEBUG_KERNEL
699 help 549 help
700 If you say Y here, additional code w 550 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 551 kernel to track the life time of various objects and validate
702 the operations on those objects. 552 the operations on those objects.
703 553
704 config DEBUG_OBJECTS_SELFTEST 554 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 555 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 556 depends on DEBUG_OBJECTS
707 help 557 help
708 This enables the selftest of the obj 558 This enables the selftest of the object debug code.
709 559
710 config DEBUG_OBJECTS_FREE 560 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 561 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 562 depends on DEBUG_OBJECTS
713 help 563 help
714 This enables checks whether a k/v fr 564 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 565 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 566 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 567 much slower.
718 568
719 config DEBUG_OBJECTS_TIMERS 569 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 570 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 571 depends on DEBUG_OBJECTS
722 help 572 help
723 If you say Y here, additional code w 573 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 574 timer routines to track the life time of timer objects and
725 validate the timer operations. 575 validate the timer operations.
726 576
727 config DEBUG_OBJECTS_WORK 577 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 578 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 579 depends on DEBUG_OBJECTS
730 help 580 help
731 If you say Y here, additional code w 581 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 582 work queue routines to track the life time of work objects and
733 validate the work operations. 583 validate the work operations.
734 584
735 config DEBUG_OBJECTS_RCU_HEAD 585 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 586 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 587 depends on DEBUG_OBJECTS
738 help 588 help
739 Enable this to turn on debugging of 589 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 590
741 config DEBUG_OBJECTS_PERCPU_COUNTER 591 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 592 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 593 depends on DEBUG_OBJECTS
744 help 594 help
745 If you say Y here, additional code w 595 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 596 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 597 objects and validate the percpu counter operations.
748 598
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 599 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 600 int "debug_objects bootup default value (0-1)"
751 range 0 1 601 range 0 1
752 default "1" 602 default "1"
753 depends on DEBUG_OBJECTS 603 depends on DEBUG_OBJECTS
754 help 604 help
755 Debug objects boot parameter default 605 Debug objects boot parameter default value
756 606
757 config SHRINKER_DEBUG !! 607 config DEBUG_SLAB
758 bool "Enable shrinker debugging suppor !! 608 bool "Debug slab memory allocations"
759 depends on DEBUG_FS !! 609 depends on DEBUG_KERNEL && SLAB
>> 610 help
>> 611 Say Y here to have the kernel do limited verification on memory
>> 612 allocation as well as poisoning memory on free to catch use of freed
>> 613 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 614
>> 615 config SLUB_DEBUG_ON
>> 616 bool "SLUB debugging on by default"
>> 617 depends on SLUB && SLUB_DEBUG
>> 618 default n
>> 619 help
>> 620 Boot with debugging on by default. SLUB boots by default with
>> 621 the runtime debug capabilities switched off. Enabling this is
>> 622 equivalent to specifying the "slub_debug" parameter on boot.
>> 623 There is no support for more fine grained debug control like
>> 624 possible with slub_debug=xxx. SLUB debugging may be switched
>> 625 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 626 "slub_debug=-".
>> 627
>> 628 config SLUB_STATS
>> 629 default n
>> 630 bool "Enable SLUB performance statistics"
>> 631 depends on SLUB && SYSFS
>> 632 help
>> 633 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 634 order find ways to optimize the allocator. This should never be
>> 635 enabled for production use since keeping statistics slows down
>> 636 the allocator by a few percentage points. The slabinfo command
>> 637 supports the determination of the most active slabs to figure
>> 638 out which slabs are relevant to a particular load.
>> 639 Try running: slabinfo -DA
>> 640
>> 641 config HAVE_DEBUG_KMEMLEAK
>> 642 bool
>> 643
>> 644 config DEBUG_KMEMLEAK
>> 645 bool "Kernel memory leak detector"
>> 646 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 647 select DEBUG_FS
>> 648 select STACKTRACE if STACKTRACE_SUPPORT
>> 649 select KALLSYMS
>> 650 select CRC32
>> 651 help
>> 652 Say Y here if you want to enable the memory leak
>> 653 detector. The memory allocation/freeing is traced in a way
>> 654 similar to the Boehm's conservative garbage collector, the
>> 655 difference being that the orphan objects are not freed but
>> 656 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 657 feature will introduce an overhead to memory
>> 658 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 659 details.
>> 660
>> 661 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
>> 662 of finding leaks due to the slab objects poisoning.
>> 663
>> 664 In order to access the kmemleak file, debugfs needs to be
>> 665 mounted (usually at /sys/kernel/debug).
>> 666
>> 667 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
>> 668 int "Kmemleak memory pool size"
>> 669 depends on DEBUG_KMEMLEAK
>> 670 range 200 1000000
>> 671 default 16000
>> 672 help
>> 673 Kmemleak must track all the memory allocations to avoid
>> 674 reporting false positives. Since memory may be allocated or
>> 675 freed before kmemleak is fully initialised, use a static pool
>> 676 of metadata objects to track such callbacks. After kmemleak is
>> 677 fully initialised, this memory pool acts as an emergency one
>> 678 if slab allocations fail.
>> 679
>> 680 config DEBUG_KMEMLEAK_TEST
>> 681 tristate "Simple test for the kernel memory leak detector"
>> 682 depends on DEBUG_KMEMLEAK && m
760 help 683 help
761 Say Y to enable the shrinker debugfs !! 684 This option enables a module that explicitly leaks memory.
762 visibility into the kernel memory sh !! 685
763 Disable it to avoid an extra memory !! 686 If unsure, say N.
>> 687
>> 688 config DEBUG_KMEMLEAK_DEFAULT_OFF
>> 689 bool "Default kmemleak to off"
>> 690 depends on DEBUG_KMEMLEAK
>> 691 help
>> 692 Say Y here to disable kmemleak by default. It can then be enabled
>> 693 on the command line via kmemleak=on.
>> 694
>> 695 config DEBUG_KMEMLEAK_AUTO_SCAN
>> 696 bool "Enable kmemleak auto scan thread on boot up"
>> 697 default y
>> 698 depends on DEBUG_KMEMLEAK
>> 699 help
>> 700 Depending on the cpu, kmemleak scan may be cpu intensive and can
>> 701 stall user tasks at times. This option enables/disables automatic
>> 702 kmemleak scan at boot up.
>> 703
>> 704 Say N here to disable kmemleak auto scan thread to stop automatic
>> 705 scanning. Disabling this option disables automatic reporting of
>> 706 memory leaks.
>> 707
>> 708 If unsure, say Y.
764 709
765 config DEBUG_STACK_USAGE 710 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 711 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 712 depends on DEBUG_KERNEL && !IA64
768 help 713 help
769 Enables the display of the minimum a 714 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 715 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 <<
773 716
774 This option will slow down process c 717 This option will slow down process creation somewhat.
775 718
776 config SCHED_STACK_END_CHECK 719 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 720 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 721 depends on DEBUG_KERNEL
779 default n 722 default n
780 help 723 help
781 This option checks for a stack overr 724 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 725 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 726 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 727 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 728 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 729 is examined. The runtime overhead introduced is minimal.
787 730
788 config ARCH_HAS_DEBUG_VM_PGTABLE 731 config ARCH_HAS_DEBUG_VM_PGTABLE
789 bool 732 bool
790 help 733 help
791 An architecture should select this w 734 An architecture should select this when it can successfully
792 build and run DEBUG_VM_PGTABLE. 735 build and run DEBUG_VM_PGTABLE.
793 736
794 config DEBUG_VM_IRQSOFF <<
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 <<
797 config DEBUG_VM 737 config DEBUG_VM
798 bool "Debug VM" 738 bool "Debug VM"
799 depends on DEBUG_KERNEL 739 depends on DEBUG_KERNEL
800 help 740 help
801 Enable this to turn on extended chec 741 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 742 that may impact performance.
803 743
804 If unsure, say N. 744 If unsure, say N.
805 745
806 config DEBUG_VM_SHOOT_LAZIES !! 746 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 747 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 748 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE <<
820 help 749 help
821 Enable VM maple tree debugging infor !! 750 Enable this to turn on VMA caching debug information. Doing so
>> 751 can cause significant overhead, so only enable it in non-production
>> 752 environments.
822 753
823 If unsure, say N. 754 If unsure, say N.
824 755
825 config DEBUG_VM_RB 756 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 757 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 758 depends on DEBUG_VM
828 help 759 help
829 Enable VM red-black tree debugging i 760 Enable VM red-black tree debugging information and extra validations.
830 761
831 If unsure, say N. 762 If unsure, say N.
832 763
833 config DEBUG_VM_PGFLAGS 764 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 765 bool "Debug page-flags operations"
835 depends on DEBUG_VM 766 depends on DEBUG_VM
836 help 767 help
837 Enables extra validation on page fla 768 Enables extra validation on page flags operations.
838 769
839 If unsure, say N. 770 If unsure, say N.
840 771
841 config DEBUG_VM_PGTABLE 772 config DEBUG_VM_PGTABLE
842 bool "Debug arch page table for semant 773 bool "Debug arch page table for semantics compliance"
843 depends on MMU 774 depends on MMU
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE 775 depends on ARCH_HAS_DEBUG_VM_PGTABLE
845 default y if DEBUG_VM 776 default y if DEBUG_VM
846 help 777 help
847 This option provides a debug method 778 This option provides a debug method which can be used to test
848 architecture page table helper funct 779 architecture page table helper functions on various platforms in
849 verifying if they comply with expect 780 verifying if they comply with expected generic MM semantics. This
850 will help architecture code in makin 781 will help architecture code in making sure that any changes or
851 new additions of these helpers still 782 new additions of these helpers still conform to expected
852 semantics of the generic MM. Platfor 783 semantics of the generic MM. Platforms will have to opt in for
853 this through ARCH_HAS_DEBUG_VM_PGTAB 784 this through ARCH_HAS_DEBUG_VM_PGTABLE.
854 785
855 If unsure, say N. 786 If unsure, say N.
856 787
857 config ARCH_HAS_DEBUG_VIRTUAL 788 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 789 bool
859 790
860 config DEBUG_VIRTUAL 791 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 792 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 793 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 794 help
864 Enable some costly sanity checks in 795 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 796 catch mistakes with virt_to_page() and friends.
866 797
867 If unsure, say N. 798 If unsure, say N.
868 799
869 config DEBUG_NOMMU_REGIONS 800 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 801 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 802 depends on DEBUG_KERNEL && !MMU
872 help 803 help
873 This option causes the global tree o 804 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 805 regions to be regularly checked for invalid topology.
875 806
876 config DEBUG_MEMORY_INIT 807 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 808 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 809 default !EXPERT
879 help 810 help
880 Enable this for additional checks du 811 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 812 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 813 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 814 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 815 on the mminit_loglevel= command-line option.
885 816
886 If unsure, say Y 817 If unsure, say Y
887 818
888 config MEMORY_NOTIFIER_ERROR_INJECT 819 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 820 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 821 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 822 help
892 This option provides the ability to 823 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 824 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 825 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 826
896 If the notifier call chain should be 827 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 828 notified, write the error code to "actions/<notifier event>/error".
898 829
899 Example: Inject memory hotplug offli 830 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 831
901 # cd /sys/kernel/debug/notifier-erro 832 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 833 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 834 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 835 bash: echo: write error: Cannot allocate memory
905 836
906 To compile this code as a module, ch 837 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 838 be called memory-notifier-error-inject.
908 839
909 If unsure, say N. 840 If unsure, say N.
910 841
911 config DEBUG_PER_CPU_MAPS 842 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 843 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 844 depends on DEBUG_KERNEL
914 depends on SMP 845 depends on SMP
915 help 846 help
916 Say Y to verify that the per_cpu map 847 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 848 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 849 and decreases performance.
919 850
920 Say N if unsure. 851 Say N if unsure.
921 852
922 config DEBUG_KMAP_LOCAL 853 config DEBUG_KMAP_LOCAL
923 bool "Debug kmap_local temporary mappi 854 bool "Debug kmap_local temporary mappings"
924 depends on DEBUG_KERNEL && KMAP_LOCAL 855 depends on DEBUG_KERNEL && KMAP_LOCAL
925 help 856 help
926 This option enables additional error 857 This option enables additional error checking for the kmap_local
927 infrastructure. Disable for product 858 infrastructure. Disable for production use.
928 859
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP 860 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
930 bool 861 bool
931 862
932 config DEBUG_KMAP_LOCAL_FORCE_MAP 863 config DEBUG_KMAP_LOCAL_FORCE_MAP
933 bool "Enforce kmap_local temporary map 864 bool "Enforce kmap_local temporary mappings"
934 depends on DEBUG_KERNEL && ARCH_SUPPOR 865 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935 select KMAP_LOCAL 866 select KMAP_LOCAL
936 select DEBUG_KMAP_LOCAL 867 select DEBUG_KMAP_LOCAL
937 help 868 help
938 This option enforces temporary mappi 869 This option enforces temporary mappings through the kmap_local
939 mechanism for non-highmem pages and 870 mechanism for non-highmem pages and on non-highmem systems.
940 Disable this for production systems! 871 Disable this for production systems!
941 872
942 config DEBUG_HIGHMEM 873 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 874 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 875 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A 876 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
946 select DEBUG_KMAP_LOCAL 877 select DEBUG_KMAP_LOCAL
947 help 878 help
948 This option enables additional error 879 This option enables additional error checking for high memory
949 systems. Disable for production sys 880 systems. Disable for production systems.
950 881
951 config HAVE_DEBUG_STACKOVERFLOW 882 config HAVE_DEBUG_STACKOVERFLOW
952 bool 883 bool
953 884
954 config DEBUG_STACKOVERFLOW 885 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 886 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 887 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help 888 help
958 Say Y here if you want to check for 889 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 890 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 891 option will show detailed messages if free stack space drops
961 below a certain limit. 892 below a certain limit.
962 893
963 These kinds of bugs usually occur wh 894 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 895 kernel get too deep, especially when interrupts are
965 involved. 896 involved.
966 897
967 Use this in cases where you see appa 898 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 899 corruption, especially if it appears in 'struct thread_info'
969 900
970 If in doubt, say "N". 901 If in doubt, say "N".
971 902
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" 903 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" <<
1005 source "lib/Kconfig.kmsan" <<
1006 904
1007 endmenu # "Memory Debugging" 905 endmenu # "Memory Debugging"
1008 906
1009 config DEBUG_SHIRQ 907 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 908 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 909 depends on DEBUG_KERNEL
1012 help 910 help
1013 Enable this to generate a spurious 911 Enable this to generate a spurious interrupt just before a shared
1014 interrupt handler is deregistered ( 912 interrupt handler is deregistered (generating one when registering
1015 is currently disabled). Drivers nee 913 is currently disabled). Drivers need to handle this correctly. Some
1016 don't and need to be caught. 914 don't and need to be caught.
1017 915
1018 menu "Debug Oops, Lockups and Hangs" 916 menu "Debug Oops, Lockups and Hangs"
1019 917
1020 config PANIC_ON_OOPS 918 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 919 bool "Panic on Oops"
1022 help 920 help
1023 Say Y here to enable the kernel to 921 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 922 has the same effect as setting oops=panic on the kernel command
1025 line. 923 line.
1026 924
1027 This feature is useful to ensure th 925 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 926 anything erroneous after an oops which could result in data
1029 corruption or other issues. 927 corruption or other issues.
1030 928
1031 Say N if unsure. 929 Say N if unsure.
1032 930
1033 config PANIC_ON_OOPS_VALUE 931 config PANIC_ON_OOPS_VALUE
1034 int 932 int
1035 range 0 1 933 range 0 1
1036 default 0 if !PANIC_ON_OOPS 934 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 935 default 1 if PANIC_ON_OOPS
1038 936
1039 config PANIC_TIMEOUT 937 config PANIC_TIMEOUT
1040 int "panic timeout" 938 int "panic timeout"
1041 default 0 939 default 0
1042 help 940 help
1043 Set the timeout value (in seconds) 941 Set the timeout value (in seconds) until a reboot occurs when
1044 the kernel panics. If n = 0, then w 942 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 943 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 944 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 945
1050 config LOCKUP_DETECTOR 946 config LOCKUP_DETECTOR
1051 bool 947 bool
1052 948
1053 config SOFTLOCKUP_DETECTOR 949 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 950 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 951 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 952 select LOCKUP_DETECTOR
1057 help 953 help
1058 Say Y here to enable the kernel to 954 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 955 soft lockups.
1060 956
1061 Softlockups are bugs that cause the 957 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 958 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 959 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 960 detection and the system will stay locked up.
1065 961
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 962 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 963 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 964 depends on SOFTLOCKUP_DETECTOR
1083 help 965 help
1084 Say Y here to enable the kernel to 966 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 967 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 968 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 969 sysctl), without giving other tasks a chance to run.
1088 970
1089 The panic can be used in combinatio 971 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 972 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 973 lockup has been detected. This feature is useful for
1092 high-availability systems that have 974 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 975 where a lockup must be resolved ASAP.
1094 976
1095 Say N if unsure. 977 Say N if unsure.
1096 978
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 979 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 980 int
>> 981 depends on SOFTLOCKUP_DETECTOR
>> 982 range 0 1
>> 983 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 984 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 985
>> 986 config HARDLOCKUP_DETECTOR_PERF
1098 bool 987 bool
1099 depends on SMP !! 988 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 989
1102 # 990 #
1103 # Global switch whether to build a hardlockup !! 991 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 992 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 993 #
1107 # s390: it reported many false positive !! 994 config HARDLOCKUP_CHECK_TIMESTAMP
>> 995 bool
>> 996
1108 # 997 #
1109 # sparc64: has a custom implementation !! 998 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 999 # lockup detector rather than the perf based detector.
1111 # 1000 #
1112 config HARDLOCKUP_DETECTOR 1001 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 1002 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 1003 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 1004 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 1005 select LOCKUP_DETECTOR
1120 !! 1006 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
>> 1007 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121 help 1008 help
1122 Say Y here to enable the kernel to 1009 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 1010 hard lockups.
1124 1011
1125 Hardlockups are bugs that cause the 1012 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 1013 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 1014 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 1015 and the system will stay locked up.
1129 1016
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 1017 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 1018 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 1019 depends on HARDLOCKUP_DETECTOR
1190 help 1020 help
1191 Say Y here to enable the kernel to 1021 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 1022 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 1023 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 1024 using the watchdog_thresh sysctl).
1195 1025
1196 Say N if unsure. 1026 Say N if unsure.
1197 1027
>> 1028 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 1029 int
>> 1030 depends on HARDLOCKUP_DETECTOR
>> 1031 range 0 1
>> 1032 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 1033 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 1034
1198 config DETECT_HUNG_TASK 1035 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 1036 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 1037 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 1038 default SOFTLOCKUP_DETECTOR
1202 help 1039 help
1203 Say Y here to enable the kernel to 1040 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 1041 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 1042 uninterruptible "D" state indefinitely.
1206 1043
1207 When a hung task is detected, the k 1044 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 1045 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 1046 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 1047 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 1048 feature has negligible overhead.
1212 1049
1213 config DEFAULT_HUNG_TASK_TIMEOUT 1050 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 1051 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 1052 depends on DETECT_HUNG_TASK
1216 default 120 1053 default 120
1217 help 1054 help
1218 This option controls the default ti 1055 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 1056 to determine when a task has become non-responsive and should
1220 be considered hung. 1057 be considered hung.
1221 1058
1222 It can be adjusted at runtime via t 1059 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 1060 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 1061 /proc/sys/kernel/hung_task_timeout_secs.
1225 1062
1226 A timeout of 0 disables the check. 1063 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 1064 Keeping the default should be fine in most cases.
1228 1065
1229 config BOOTPARAM_HUNG_TASK_PANIC 1066 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 1067 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 1068 depends on DETECT_HUNG_TASK
1232 help 1069 help
1233 Say Y here to enable the kernel to 1070 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 1071 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 1072 in uninterruptible "D" state.
1236 1073
1237 The panic can be used in combinatio 1074 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 1075 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 1076 hung task has been detected. This feature is useful for
1240 high-availability systems that have 1077 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 1078 where a hung tasks must be resolved ASAP.
1242 1079
1243 Say N if unsure. 1080 Say N if unsure.
1244 1081
>> 1082 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 1083 int
>> 1084 depends on DETECT_HUNG_TASK
>> 1085 range 0 1
>> 1086 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 1087 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 1088
1245 config WQ_WATCHDOG 1089 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 1090 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 1091 depends on DEBUG_KERNEL
1248 help 1092 help
1249 Say Y here to enable stall detectio 1093 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 1094 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 1095 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 1096 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 1097 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 1098 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 1099
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 1100 config TEST_LOCKUP
1270 tristate "Test module to generate loc 1101 tristate "Test module to generate lockups"
1271 depends on m 1102 depends on m
1272 help 1103 help
1273 This builds the "test_lockup" modul 1104 This builds the "test_lockup" module that helps to make sure
1274 that watchdogs and lockup detectors 1105 that watchdogs and lockup detectors are working properly.
1275 1106
1276 Depending on module parameters it c 1107 Depending on module parameters it could emulate soft or hard
1277 lockup, "hung task", or locking arb 1108 lockup, "hung task", or locking arbitrary lock for a long time.
1278 Also it could generate series of lo 1109 Also it could generate series of lockups with cooling-down periods.
1279 1110
1280 If unsure, say N. 1111 If unsure, say N.
1281 1112
1282 endmenu # "Debug lockups and hangs" 1113 endmenu # "Debug lockups and hangs"
1283 1114
1284 menu "Scheduler Debugging" 1115 menu "Scheduler Debugging"
1285 1116
1286 config SCHED_DEBUG 1117 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 1118 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 1119 depends on DEBUG_KERNEL && PROC_FS
1289 default y 1120 default y
1290 help 1121 help
1291 If you say Y here, the /sys/kernel/ !! 1122 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 1123 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 1124 option is minimal.
1294 1125
1295 config SCHED_INFO 1126 config SCHED_INFO
1296 bool 1127 bool
1297 default n 1128 default n
1298 1129
1299 config SCHEDSTATS 1130 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1131 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1132 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1133 select SCHED_INFO
1303 help 1134 help
1304 If you say Y here, additional code 1135 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1136 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1137 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1138 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1139 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1140 application, you can say N to avoid the very slight overhead
1310 this adds. 1141 this adds.
1311 1142
1312 endmenu 1143 endmenu
1313 1144
1314 config DEBUG_TIMEKEEPING 1145 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1146 bool "Enable extra timekeeping sanity checking"
1316 help 1147 help
1317 This option will enable additional 1148 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1149 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1150 problems are suspected.
1320 1151
1321 This may include checks in the time 1152 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1153 option may have a (very small) performance impact to some
1323 workloads. 1154 workloads.
1324 1155
1325 If unsure, say N. 1156 If unsure, say N.
1326 1157
1327 config DEBUG_PREEMPT 1158 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1159 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION 1160 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
>> 1161 default y
1330 help 1162 help
1331 If you say Y here then the kernel w 1163 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1164 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1165 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1166 will detect preemption count underflows.
1335 1167
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 1168 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1169
1342 config LOCK_DEBUGGING_SUPPORT 1170 config LOCK_DEBUGGING_SUPPORT
1343 bool 1171 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1172 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1173 default y
1346 1174
1347 config PROVE_LOCKING 1175 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1176 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1177 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1178 select LOCKDEP
1351 select DEBUG_SPINLOCK 1179 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1180 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1181 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1182 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1183 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1184 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE 1185 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358 select TRACE_IRQFLAGS 1186 select TRACE_IRQFLAGS
1359 default n 1187 default n
1360 help 1188 help
1361 This feature enables the kernel to p 1189 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1190 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1191 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1192 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1193 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1194 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1195 deadlock.
1368 1196
1369 In short, this feature enables the k 1197 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1198 related deadlocks before they actually occur.
1371 1199
1372 The proof does not depend on how har 1200 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1201 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1202 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1203 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1204 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1205 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1206 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1207 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1208 makes the deadlock theoretically possible).
1381 1209
1382 If a deadlock is impossible (i.e. th 1210 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1211 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1212 kernel reports nothing.
1385 1213
1386 NOTE: this feature can also be enabl 1214 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1215 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1216 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1217 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1218 arbitrary combination of these separate locking variants.
1391 1219
1392 For more details, see Documentation/ 1220 For more details, see Documentation/locking/lockdep-design.rst.
1393 1221
1394 config PROVE_RAW_LOCK_NESTING 1222 config PROVE_RAW_LOCK_NESTING
1395 bool "Enable raw_spinlock - spinlock 1223 bool "Enable raw_spinlock - spinlock nesting checks"
1396 depends on PROVE_LOCKING 1224 depends on PROVE_LOCKING
1397 default n 1225 default n
1398 help 1226 help
1399 Enable the raw_spinlock vs. spinlock 1227 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400 that the lock nesting rules for PREE 1228 that the lock nesting rules for PREEMPT_RT enabled kernels are
1401 not violated. 1229 not violated.
1402 1230
1403 NOTE: There are known nesting proble 1231 NOTE: There are known nesting problems. So if you enable this
1404 option expect lockdep splats until t 1232 option expect lockdep splats until these problems have been fully
1405 addressed which is work in progress. 1233 addressed which is work in progress. This config switch allows to
1406 identify and analyze these problems. 1234 identify and analyze these problems. It will be removed and the
1407 check permanently enabled once the m !! 1235 check permanentely enabled once the main issues have been fixed.
1408 1236
1409 If unsure, select N. 1237 If unsure, select N.
1410 1238
1411 config LOCK_STAT 1239 config LOCK_STAT
1412 bool "Lock usage statistics" 1240 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1241 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1242 select LOCKDEP
1415 select DEBUG_SPINLOCK 1243 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1244 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1245 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1246 select DEBUG_LOCK_ALLOC
1419 default n 1247 default n
1420 help 1248 help
1421 This feature enables tracking lock c 1249 This feature enables tracking lock contention points
1422 1250
1423 For more details, see Documentation/ 1251 For more details, see Documentation/locking/lockstat.rst
1424 1252
1425 This also enables lock events requir 1253 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1254 subcommand of perf.
1427 If you want to use "perf lock", you 1255 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1256 CONFIG_EVENT_TRACING.
1429 1257
1430 CONFIG_LOCK_STAT defines "contended" 1258 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1259 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1260
1433 config DEBUG_RT_MUTEXES 1261 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1262 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1263 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1264 help
1437 This allows rt mutex semantics viola 1265 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1266 deadlocks (lockups) to be detected and reported automatically.
1439 1267
1440 config DEBUG_SPINLOCK 1268 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1269 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1270 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1271 select UNINLINE_SPIN_UNLOCK
1444 help 1272 help
1445 Say Y here and build SMP to catch m 1273 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1274 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1275 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1276 deadlocks are also debuggable.
1449 1277
1450 config DEBUG_MUTEXES 1278 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1279 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1280 depends on DEBUG_KERNEL
1453 help 1281 help
1454 This feature allows mutex semantics 1282 This feature allows mutex semantics violations to be detected and
1455 reported. 1283 reported.
1456 1284
1457 config DEBUG_WW_MUTEX_SLOWPATH 1285 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1286 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1287 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1288 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1289 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1290 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1291 help
1465 This feature enables slowpath testin 1292 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1293 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1294 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1295 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1296 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1297 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1298 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1299 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1300 you are a distro, do not.
1474 1301
1475 config DEBUG_RWSEMS 1302 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1303 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1304 depends on DEBUG_KERNEL
1478 help 1305 help
1479 This debugging feature allows misma 1306 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1307 and unlocks to be detected and reported.
1481 1308
1482 config DEBUG_LOCK_ALLOC 1309 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1310 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1311 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1312 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1313 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1314 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1315 select LOCKDEP
1489 help 1316 help
1490 This feature will check whether any 1317 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1318 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1319 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1320 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1321 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1322 held during task exit.
1496 1323
1497 config LOCKDEP 1324 config LOCKDEP
1498 bool 1325 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1326 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1327 select STACKTRACE
>> 1328 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1501 select KALLSYMS 1329 select KALLSYMS
1502 select KALLSYMS_ALL 1330 select KALLSYMS_ALL
1503 1331
1504 config LOCKDEP_SMALL 1332 config LOCKDEP_SMALL
1505 bool 1333 bool
1506 1334
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 1335 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1336 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1337 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS <<
1551 help 1338 help
1552 If you say Y here, the lock depende 1339 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1340 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1341 of more runtime overhead.
1555 1342
1556 config DEBUG_ATOMIC_SLEEP 1343 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1344 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1345 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1346 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1347 depends on !ARCH_NO_PREEMPT
1561 help 1348 help
1562 If you say Y here, various routines 1349 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1350 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1351 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1352 sections, inside an interrupt, etc...
1566 1353
1567 config DEBUG_LOCKING_API_SELFTESTS 1354 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1355 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1356 depends on DEBUG_KERNEL
1570 help 1357 help
1571 Say Y here if you want the kernel t 1358 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1359 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1360 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1361 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1362 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1363 mutexes and rwsems.
1577 1364
1578 config LOCK_TORTURE_TEST 1365 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1366 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1367 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1368 select TORTURE_TEST
1582 help 1369 help
1583 This option provides a kernel modul 1370 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1371 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1372 after the fact on the running kernel to be tested, if desired.
1586 1373
1587 Say Y here if you want kernel locki 1374 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1375 to be built into the kernel.
1589 Say M if you want these torture tes 1376 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1377 Say N if you are unsure.
1591 1378
1592 config WW_MUTEX_SELFTEST 1379 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1380 tristate "Wait/wound mutex selftests"
1594 help 1381 help
1595 This option provides a kernel modul 1382 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1383 on the struct ww_mutex locking API.
1597 1384
1598 It is recommended to enable DEBUG_W 1385 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1386 with this test harness.
1600 1387
1601 Say M if you want these self tests 1388 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1389 Say N if you are unsure.
1603 1390
1604 config SCF_TORTURE_TEST 1391 config SCF_TORTURE_TEST
1605 tristate "torture tests for smp_call_ 1392 tristate "torture tests for smp_call_function*()"
1606 depends on DEBUG_KERNEL 1393 depends on DEBUG_KERNEL
1607 select TORTURE_TEST 1394 select TORTURE_TEST
1608 help 1395 help
1609 This option provides a kernel modul 1396 This option provides a kernel module that runs torture tests
1610 on the smp_call_function() family o 1397 on the smp_call_function() family of primitives. The kernel
1611 module may be built after the fact 1398 module may be built after the fact on the running kernel to
1612 be tested, if desired. 1399 be tested, if desired.
1613 1400
1614 config CSD_LOCK_WAIT_DEBUG 1401 config CSD_LOCK_WAIT_DEBUG
1615 bool "Debugging for csd_lock_wait(), 1402 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616 depends on DEBUG_KERNEL 1403 depends on DEBUG_KERNEL
1617 depends on 64BIT 1404 depends on 64BIT
1618 default n 1405 default n
1619 help 1406 help
1620 This option enables debug prints wh 1407 This option enables debug prints when CPUs are slow to respond
1621 to the smp_call_function*() IPI wra 1408 to the smp_call_function*() IPI wrappers. These debug prints
1622 include the IPI handler function cu 1409 include the IPI handler function currently executing (if any)
1623 and relevant stack traces. 1410 and relevant stack traces.
1624 1411
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 1412 endmenu # lock debugging
1635 1413
1636 config TRACE_IRQFLAGS 1414 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT 1415 depends on TRACE_IRQFLAGS_SUPPORT
1638 bool 1416 bool
1639 help 1417 help
1640 Enables hooks to interrupt enabling 1418 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1419 either tracing or lock debugging.
1642 1420
1643 config TRACE_IRQFLAGS_NMI 1421 config TRACE_IRQFLAGS_NMI
1644 def_bool y 1422 def_bool y
1645 depends on TRACE_IRQFLAGS 1423 depends on TRACE_IRQFLAGS
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT 1424 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647 1425
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 1426 config STACKTRACE
1667 bool "Stack backtrace support" 1427 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1428 depends on STACKTRACE_SUPPORT
1669 help 1429 help
1670 This option causes the kernel to cr 1430 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1431 every process, showing its current stack trace.
1672 It is also used by various kernel d 1432 It is also used by various kernel debugging features that require
1673 stack trace generation. 1433 stack trace generation.
1674 1434
1675 config WARN_ALL_UNSEEDED_RANDOM 1435 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1436 bool "Warn for all uses of unseeded randomness"
1677 default n 1437 default n
1678 help 1438 help
1679 Some parts of the kernel contain bu 1439 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1440 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1441 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1442 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1443 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1444 are going wrong, so that they might contact developers about fixing
1685 it. 1445 it.
1686 1446
1687 Unfortunately, on some models of so 1447 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1448 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1449 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1450 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1451 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1452 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1453 However, since users cannot do anything actionable to
1694 address this, by default this optio !! 1454 address this, by default the kernel will issue only a single
>> 1455 warning for the first use of unseeded randomness.
1695 1456
1696 Say Y here if you want to receive w 1457 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1458 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1459 those developers interested in improving the security of
1699 Linux kernels running on their arch 1460 Linux kernels running on their architecture (or
1700 subarchitecture). 1461 subarchitecture).
1701 1462
1702 config DEBUG_KOBJECT 1463 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1464 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1465 depends on DEBUG_KERNEL
1705 help 1466 help
1706 If you say Y here, some extra kobje 1467 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1468 to the syslog.
1708 1469
1709 config DEBUG_KOBJECT_RELEASE 1470 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1471 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1472 depends on DEBUG_OBJECTS_TIMERS
1712 help 1473 help
1713 kobjects are reference counted obje 1474 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1475 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1476 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1477 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1478 example of this would be a struct device which has just been
1718 unregistered. 1479 unregistered.
1719 1480
1720 However, some buggy drivers assume 1481 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1482 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1483 goes completely against the principles of a refcounted object.
1723 1484
1724 If you say Y here, the kernel will 1485 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1486 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1487 kind of kobject release bug.
1727 1488
1728 config HAVE_DEBUG_BUGVERBOSE 1489 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1490 bool
1730 1491
1731 menu "Debug kernel data structures" 1492 menu "Debug kernel data structures"
1732 1493
1733 config DEBUG_LIST 1494 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1495 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1496 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1497 help
1738 Enable this to turn on extended che !! 1498 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1499 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 1500
1745 If unsure, say N. 1501 If unsure, say N.
1746 1502
1747 config DEBUG_PLIST 1503 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1504 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1505 depends on DEBUG_KERNEL
1750 help 1506 help
1751 Enable this to turn on extended che 1507 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1508 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1509 list multiple times during each manipulation.
1754 1510
1755 If unsure, say N. 1511 If unsure, say N.
1756 1512
1757 config DEBUG_SG 1513 config DEBUG_SG
1758 bool "Debug SG table operations" 1514 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1515 depends on DEBUG_KERNEL
1760 help 1516 help
1761 Enable this to turn on checks on sc 1517 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1518 help find problems with drivers that do not properly initialize
1763 their sg tables. 1519 their sg tables.
1764 1520
1765 If unsure, say N. 1521 If unsure, say N.
1766 1522
1767 config DEBUG_NOTIFIERS 1523 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1524 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1525 depends on DEBUG_KERNEL
1770 help 1526 help
1771 Enable this to turn on sanity check 1527 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1528 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1529 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1530 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1531 performance, say N.
1776 1532
1777 config DEBUG_CLOSURES !! 1533 config BUG_ON_DATA_CORRUPTION
1778 bool "Debug closures (bcache async wi !! 1534 bool "Trigger a BUG when data corruption is detected"
1779 depends on CLOSURES !! 1535 select DEBUG_LIST
1780 select DEBUG_FS !! 1536 help
1781 help !! 1537 Select this option if the kernel should BUG when it encounters
1782 Keeps all active closures in a link !! 1538 data corruption in kernel memory structures when they get checked
1783 interface to list them, which makes !! 1539 for validity.
1784 operations that get stuck. !! 1540
>> 1541 If unsure, say N.
1785 1542
1786 config DEBUG_MAPLE_TREE !! 1543 endmenu
1787 bool "Debug maple trees" !! 1544
>> 1545 config DEBUG_CREDENTIALS
>> 1546 bool "Debug credential management"
1788 depends on DEBUG_KERNEL 1547 depends on DEBUG_KERNEL
1789 help 1548 help
1790 Enable maple tree debugging informa !! 1549 Enable this to turn on some debug checking for credential
>> 1550 management. The additional code keeps track of the number of
>> 1551 pointers from task_structs to any given cred struct, and checks to
>> 1552 see that this number never exceeds the usage count of the cred
>> 1553 struct.
1791 1554
1792 If unsure, say N. !! 1555 Furthermore, if SELinux is enabled, this also checks that the
>> 1556 security pointer in the cred struct is never seen to be invalid.
1793 1557
1794 endmenu !! 1558 If unsure, say N.
1795 1559
1796 source "kernel/rcu/Kconfig.debug" 1560 source "kernel/rcu/Kconfig.debug"
1797 1561
1798 config DEBUG_WQ_FORCE_RR_CPU 1562 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1563 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1564 depends on DEBUG_KERNEL
1801 default n 1565 default n
1802 help 1566 help
1803 Workqueue used to implicitly guaran 1567 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1568 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1569 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1570 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1571 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1572 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1573 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1574 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1575 be impacted.
1812 1576
>> 1577 config DEBUG_BLOCK_EXT_DEVT
>> 1578 bool "Force extended block device numbers and spread them"
>> 1579 depends on DEBUG_KERNEL
>> 1580 depends on BLOCK
>> 1581 default n
>> 1582 help
>> 1583 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1584 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1585 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1586 is broken.
>> 1587
>> 1588 Conventionally, block device numbers are allocated from
>> 1589 predetermined contiguous area. However, extended block area
>> 1590 may introduce non-contiguous block device numbers. This
>> 1591 option forces most block device numbers to be allocated from
>> 1592 the extended space and spreads them to discover kernel or
>> 1593 userland code paths which assume predetermined contiguous
>> 1594 device number allocation.
>> 1595
>> 1596 Note that turning on this debug option shuffles all the
>> 1597 device numbers for all IDE and SCSI devices including libata
>> 1598 ones, so root partition specified using device number
>> 1599 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1600 Textual device names (root=/dev/sdXn) will continue to work.
>> 1601
>> 1602 Say N if you are unsure.
>> 1603
1813 config CPU_HOTPLUG_STATE_CONTROL 1604 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1605 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1606 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1607 depends on HOTPLUG_CPU
1817 default n 1608 default n
1818 help 1609 help
1819 Allows to write steps between "offl 1610 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1611 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1612 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1613 restarted at arbitrary points yet.
1823 1614
1824 Say N if your are unsure. 1615 Say N if your are unsure.
1825 1616
1826 config LATENCYTOP 1617 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1618 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1619 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1620 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1621 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P 1622 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832 select KALLSYMS 1623 select KALLSYMS
1833 select KALLSYMS_ALL 1624 select KALLSYMS_ALL
1834 select STACKTRACE 1625 select STACKTRACE
1835 select SCHEDSTATS 1626 select SCHEDSTATS
>> 1627 select SCHED_DEBUG
1836 help 1628 help
1837 Enable this option if you want to u 1629 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1630 to find out which userspace is blocking on what kernel operations.
1839 1631
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" 1632 source "kernel/trace/Kconfig"
1851 1633
1852 config PROVIDE_OHCI1394_DMA_INIT 1634 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1635 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1636 depends on PCI && X86
1855 help 1637 help
1856 If you want to debug problems which 1638 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1639 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1640 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1641 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1642 specification which is now the standard for FireWire controllers.
1861 1643
1862 With remote DMA, you can monitor th 1644 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1645 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1646 Even controlling a kernel debugger is possible using remote DMA.
1865 1647
1866 Usage: 1648 Usage:
1867 1649
1868 If ohci1394_dma=early is used as bo 1650 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1651 all OHCI1394 controllers which are found in the PCI config space.
1870 1652
1871 As all changes to the FireWire bus 1653 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1654 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1655 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1656 the debugging host before booting the debug target for debugging.
1875 1657
1876 This code (~1k) is freed after boot 1658 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1659 in charge of the OHCI-1394 controllers should be used instead.
1878 1660
1879 See Documentation/core-api/debuggin 1661 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880 1662
1881 source "samples/Kconfig" 1663 source "samples/Kconfig"
1882 1664
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1665 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1666 bool
1885 1667
1886 config STRICT_DEVMEM 1668 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1669 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1670 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED 1671 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1672 default y if PPC || X86 || ARM64
1891 help 1673 help
1892 If this option is disabled, you all 1674 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1675 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1676 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1677 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1678 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1679 use due to the cache aliasing requirements.
1898 1680
1899 If this option is switched on, and 1681 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1682 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1683 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1684 users of /dev/mem.
1903 1685
1904 If in doubt, say Y. 1686 If in doubt, say Y.
1905 1687
1906 config IO_STRICT_DEVMEM 1688 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1689 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1690 depends on STRICT_DEVMEM
1909 help 1691 help
1910 If this option is disabled, you all 1692 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1693 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1694 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1695 specific access can be used by people debugging kernel drivers.
1914 1696
1915 If this option is switched on, the 1697 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1698 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1699 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1700 if the driver using a given range cannot be disabled.
1919 1701
1920 If in doubt, say Y. 1702 If in doubt, say Y.
1921 1703
1922 menu "$(SRCARCH) Debugging" 1704 menu "$(SRCARCH) Debugging"
1923 1705
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1706 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1707
1926 endmenu 1708 endmenu
1927 1709
1928 menu "Kernel Testing and Coverage" 1710 menu "Kernel Testing and Coverage"
1929 1711
1930 source "lib/kunit/Kconfig" 1712 source "lib/kunit/Kconfig"
1931 1713
1932 config NOTIFIER_ERROR_INJECTION 1714 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1715 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1716 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1717 select DEBUG_FS
1936 help 1718 help
1937 This option provides the ability to 1719 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1720 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1721 handling of notifier call chain failures.
1940 1722
1941 Say N if unsure. 1723 Say N if unsure.
1942 1724
1943 config PM_NOTIFIER_ERROR_INJECT 1725 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1726 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1727 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1728 default m if PM_DEBUG
1947 help 1729 help
1948 This option provides the ability to 1730 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1731 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1732 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1733
1952 If the notifier call chain should b 1734 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1735 notified, write the error code to "actions/<notifier event>/error".
1954 1736
1955 Example: Inject PM suspend error (- 1737 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1738
1957 # cd /sys/kernel/debug/notifier-err 1739 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1740 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1741 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1742 bash: echo: write error: Cannot allocate memory
1961 1743
1962 To compile this code as a module, c 1744 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1745 be called pm-notifier-error-inject.
1964 1746
1965 If unsure, say N. 1747 If unsure, say N.
1966 1748
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1749 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1750 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1751 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1752 help
1971 This option provides the ability to 1753 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1754 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1755 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1756 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1757
1976 If the notifier call chain should b 1758 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1759 notified, write the error code to "actions/<notifier event>/error".
1978 1760
1979 To compile this code as a module, c 1761 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1762 be called of-reconfig-notifier-error-inject.
1981 1763
1982 If unsure, say N. 1764 If unsure, say N.
1983 1765
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1766 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1767 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1768 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1769 help
1988 This option provides the ability to 1770 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1771 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1772 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1773
1992 If the notifier call chain should b 1774 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1775 notified, write the error code to "actions/<notifier event>/error".
1994 1776
1995 Example: Inject netdevice mtu chang 1777 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1778
1997 # cd /sys/kernel/debug/notifier-err 1779 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1780 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1781 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1782 RTNETLINK answers: Invalid argument
2001 1783
2002 To compile this code as a module, c 1784 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1785 be called netdev-notifier-error-inject.
2004 1786
2005 If unsure, say N. 1787 If unsure, say N.
2006 1788
2007 config FUNCTION_ERROR_INJECTION 1789 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" !! 1790 def_bool y
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1791 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 1792
2017 config FAULT_INJECTION 1793 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1794 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1795 depends on DEBUG_KERNEL
2020 help 1796 help
2021 Provide fault-injection framework. 1797 Provide fault-injection framework.
2022 For more details, see Documentation 1798 For more details, see Documentation/fault-injection/.
2023 1799
2024 config FAILSLAB 1800 config FAILSLAB
2025 bool "Fault-injection capability for 1801 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1802 depends on FAULT_INJECTION
>> 1803 depends on SLAB || SLUB
2027 help 1804 help
2028 Provide fault-injection capability 1805 Provide fault-injection capability for kmalloc.
2029 1806
2030 config FAIL_PAGE_ALLOC 1807 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for 1808 bool "Fault-injection capability for alloc_pages()"
2032 depends on FAULT_INJECTION 1809 depends on FAULT_INJECTION
2033 help 1810 help
2034 Provide fault-injection capability 1811 Provide fault-injection capability for alloc_pages().
2035 1812
2036 config FAULT_INJECTION_USERCOPY 1813 config FAULT_INJECTION_USERCOPY
2037 bool "Fault injection capability for 1814 bool "Fault injection capability for usercopy functions"
2038 depends on FAULT_INJECTION 1815 depends on FAULT_INJECTION
2039 help 1816 help
2040 Provides fault-injection capability 1817 Provides fault-injection capability to inject failures
2041 in usercopy functions (copy_from_us 1818 in usercopy functions (copy_from_user(), get_user(), ...).
2042 1819
2043 config FAIL_MAKE_REQUEST 1820 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1821 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1822 depends on FAULT_INJECTION && BLOCK
2046 help 1823 help
2047 Provide fault-injection capability 1824 Provide fault-injection capability for disk IO.
2048 1825
2049 config FAIL_IO_TIMEOUT 1826 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1827 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1828 depends on FAULT_INJECTION && BLOCK
2052 help 1829 help
2053 Provide fault-injection capability 1830 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1831 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1832 thus exercising the error handling.
2056 1833
2057 Only works with drivers that use th 1834 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1835 for others it wont do anything.
2059 1836
2060 config FAIL_FUTEX 1837 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1838 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1839 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1840 depends on FAULT_INJECTION && FUTEX
2064 help 1841 help
2065 Provide fault-injection capability 1842 Provide fault-injection capability for futexes.
2066 1843
2067 config FAULT_INJECTION_DEBUG_FS 1844 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1845 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1846 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1847 help
2071 Enable configuration of fault-injec 1848 Enable configuration of fault-injection capabilities via debugfs.
2072 1849
2073 config FAIL_FUNCTION 1850 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1851 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1852 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1853 help
2077 Provide function-based fault-inject 1854 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1855 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1856 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1857 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1858 error handling in various subsystems.
2082 1859
2083 config FAIL_MMC_REQUEST 1860 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1861 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1862 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1863 help
2087 Provide fault-injection capability 1864 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1865 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1866 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1867 and to test how the mmc host driver handles retries from
2091 the block device. 1868 the block device.
2092 1869
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 1870 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1871 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1872 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1873 depends on !X86_64
2115 select STACKTRACE 1874 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P 1875 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117 help 1876 help
2118 Provide stacktrace filter for fault 1877 Provide stacktrace filter for fault-injection capabilities
2119 1878
2120 config ARCH_HAS_KCOV 1879 config ARCH_HAS_KCOV
2121 bool 1880 bool
2122 help 1881 help
2123 An architecture should select this 1882 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 1883 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 1884 disabling instrumentation for some early boot code.
2126 1885
2127 config CC_HAS_SANCOV_TRACE_PC 1886 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 1887 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 1888
2130 1889
2131 config KCOV 1890 config KCOV
2132 bool "Code coverage for fuzzing" 1891 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 1892 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 1893 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 1894 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 1895 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK <<
2140 help 1896 help
2141 KCOV exposes kernel code coverage i 1897 KCOV exposes kernel code coverage information in a form suitable
2142 for coverage-guided fuzzing (random 1898 for coverage-guided fuzzing (randomized testing).
2143 1899
>> 1900 If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> 1901 different machines and across reboots. If you need stable PC values,
>> 1902 disable RANDOMIZE_BASE.
>> 1903
2144 For more details, see Documentation 1904 For more details, see Documentation/dev-tools/kcov.rst.
2145 1905
2146 config KCOV_ENABLE_COMPARISONS 1906 config KCOV_ENABLE_COMPARISONS
2147 bool "Enable comparison operands coll 1907 bool "Enable comparison operands collection by KCOV"
2148 depends on KCOV 1908 depends on KCOV
2149 depends on $(cc-option,-fsanitize-cov 1909 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150 help 1910 help
2151 KCOV also exposes operands of every 1911 KCOV also exposes operands of every comparison in the instrumented
2152 code along with operand sizes and P 1912 code along with operand sizes and PCs of the comparison instructions.
2153 These operands can be used by fuzzi 1913 These operands can be used by fuzzing engines to improve the quality
2154 of fuzzing coverage. 1914 of fuzzing coverage.
2155 1915
2156 config KCOV_INSTRUMENT_ALL 1916 config KCOV_INSTRUMENT_ALL
2157 bool "Instrument all code by default" 1917 bool "Instrument all code by default"
2158 depends on KCOV 1918 depends on KCOV
2159 default y 1919 default y
2160 help 1920 help
2161 If you are doing generic system cal 1921 If you are doing generic system call fuzzing (like e.g. syzkaller),
2162 then you will want to instrument th 1922 then you will want to instrument the whole kernel and you should
2163 say y here. If you are doing more t 1923 say y here. If you are doing more targeted fuzzing (like e.g.
2164 filesystem fuzzing with AFL) then y 1924 filesystem fuzzing with AFL) then you will want to enable coverage
2165 for more specific subsets of files, 1925 for more specific subsets of files, and should say n here.
2166 1926
2167 config KCOV_IRQ_AREA_SIZE 1927 config KCOV_IRQ_AREA_SIZE
2168 hex "Size of interrupt coverage colle 1928 hex "Size of interrupt coverage collection area in words"
2169 depends on KCOV 1929 depends on KCOV
2170 default 0x40000 1930 default 0x40000
2171 help 1931 help
2172 KCOV uses preallocated per-cpu area 1932 KCOV uses preallocated per-cpu areas to collect coverage from
2173 soft interrupts. This specifies the 1933 soft interrupts. This specifies the size of those areas in the
2174 number of unsigned long words. 1934 number of unsigned long words.
2175 1935
2176 menuconfig RUNTIME_TESTING_MENU 1936 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 1937 bool "Runtime Testing"
2178 default y !! 1938 def_bool y
2179 1939
2180 if RUNTIME_TESTING_MENU 1940 if RUNTIME_TESTING_MENU
2181 1941
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 1942 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 1943 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 1944 depends on DEBUG_FS
2220 help 1945 help
2221 This module enables testing of the di 1946 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 1947 inducing system failures at predefined crash points.
2223 If you don't need it: say N 1948 If you don't need it: say N
2224 Choose M here to compile this code as 1949 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 1950 called lkdtm.
2226 1951
2227 Documentation on how to use the modul 1952 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 1953 Documentation/fault-injection/provoke-crashes.rst
2229 1954
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 1955 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 1956 tristate "Linked list sorting test"
2244 depends on KUNIT !! 1957 depends on DEBUG_KERNEL || m
2245 default KUNIT_ALL_TESTS <<
2246 help 1958 help
2247 Enable this to turn on 'list_sort() 1959 Enable this to turn on 'list_sort()' function test. This test is
2248 executed only once during system bo 1960 executed only once during system boot (so affects only boot time),
2249 or at module load time. 1961 or at module load time.
2250 1962
2251 If unsure, say N. 1963 If unsure, say N.
2252 1964
2253 config TEST_MIN_HEAP 1965 config TEST_MIN_HEAP
2254 tristate "Min heap test" 1966 tristate "Min heap test"
2255 depends on DEBUG_KERNEL || m 1967 depends on DEBUG_KERNEL || m
2256 help 1968 help
2257 Enable this to turn on min heap fun 1969 Enable this to turn on min heap function tests. This test is
2258 executed only once during system bo 1970 executed only once during system boot (so affects only boot time),
2259 or at module load time. 1971 or at module load time.
2260 1972
2261 If unsure, say N. 1973 If unsure, say N.
2262 1974
2263 config TEST_SORT 1975 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 1976 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 1977 depends on DEBUG_KERNEL || m
2276 help 1978 help
2277 Enable this to turn on 'do_div()' f !! 1979 This option enables the self-test function of 'sort()' at boot,
2278 executed only once during system bo <<
2279 or at module load time. 1980 or at module load time.
2280 1981
2281 If unsure, say N. 1982 If unsure, say N.
2282 1983
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 1984 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 1985 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 1986 depends on DEBUG_KERNEL
2298 depends on KPROBES 1987 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 1988 help
2303 This option provides for testing ba 1989 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 1990 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 1991 verified for functionality.
2306 1992
2307 Say N if you are unsure. 1993 Say N if you are unsure.
2308 1994
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 1995 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 1996 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 1997 depends on DEBUG_KERNEL
2324 help 1998 help
2325 This option provides a kernel modul 1999 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 2000 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 2001 for distributions or general kernels, but only for kernel
2328 developers working on architecture 2002 developers working on architecture code.
2329 2003
2330 Note that if you want to also test 2004 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 2005 have to enable STACKTRACE as well.
2332 2006
2333 Say N if you are unsure. 2007 Say N if you are unsure.
2334 2008
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 2009 config RBTREE_TEST
2346 tristate "Red-Black tree test" 2010 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 2011 depends on DEBUG_KERNEL
2348 help 2012 help
2349 A benchmark measuring the performan 2013 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 2014 Also includes rbtree invariant checks.
2351 2015
2352 config REED_SOLOMON_TEST 2016 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 2017 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 2018 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 2019 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 2020 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 2021 select REED_SOLOMON_DEC16
2358 help 2022 help
2359 This option enables the self-test f 2023 This option enables the self-test function of rslib at boot,
2360 or at module load time. 2024 or at module load time.
2361 2025
2362 If unsure, say N. 2026 If unsure, say N.
2363 2027
2364 config INTERVAL_TREE_TEST 2028 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 2029 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 2030 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 2031 select INTERVAL_TREE
2368 help 2032 help
2369 A benchmark measuring the performan 2033 A benchmark measuring the performance of the interval tree library
2370 2034
2371 config PERCPU_TEST 2035 config PERCPU_TEST
2372 tristate "Per cpu operations test" 2036 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 2037 depends on m && DEBUG_KERNEL
2374 help 2038 help
2375 Enable this option to build test mo 2039 Enable this option to build test module which validates per-cpu
2376 operations. 2040 operations.
2377 2041
2378 If unsure, say N. 2042 If unsure, say N.
2379 2043
2380 config ATOMIC64_SELFTEST 2044 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 2045 tristate "Perform an atomic64_t self-test"
2382 help 2046 help
2383 Enable this option to test the atom 2047 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 2048 at module load time.
2385 2049
2386 If unsure, say N. 2050 If unsure, say N.
2387 2051
2388 config ASYNC_RAID6_TEST 2052 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 2053 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 2054 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 2055 select ASYNC_MEMCPY
2392 help 2056 help
2393 This is a one-shot self test that p 2057 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 2058 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 2059 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 2060 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 2061 engine if one is available.
2398 2062
2399 If unsure, say N. 2063 If unsure, say N.
2400 2064
2401 config TEST_HEXDUMP 2065 config TEST_HEXDUMP
2402 tristate "Test functions located in t 2066 tristate "Test functions located in the hexdump module at runtime"
2403 2067
2404 config STRING_KUNIT_TEST !! 2068 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 2069 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 2070
2409 config STRING_HELPERS_KUNIT_TEST !! 2071 config TEST_STRSCPY
2410 tristate "KUnit test string helpers a !! 2072 tristate "Test strscpy*() family of functions at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 2073
2414 config TEST_KSTRTOX 2074 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 2075 tristate "Test kstrto*() family of functions at runtime"
2416 2076
2417 config TEST_PRINTF 2077 config TEST_PRINTF
2418 tristate "Test printf() family of fun 2078 tristate "Test printf() family of functions at runtime"
2419 2079
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 2080 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 2081 tristate "Test bitmap_*() family of functions at runtime"
2425 help 2082 help
2426 Enable this option to test the bitm 2083 Enable this option to test the bitmap functions at boot.
2427 2084
2428 If unsure, say N. 2085 If unsure, say N.
2429 2086
2430 config TEST_UUID 2087 config TEST_UUID
2431 tristate "Test functions located in t 2088 tristate "Test functions located in the uuid module at runtime"
2432 2089
2433 config TEST_XARRAY 2090 config TEST_XARRAY
2434 tristate "Test the XArray code at run 2091 tristate "Test the XArray code at runtime"
2435 2092
2436 config TEST_MAPLE_TREE !! 2093 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 2094 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 2095
2445 config TEST_RHASHTABLE 2096 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 2097 tristate "Perform selftest on resizable hash table"
2447 help 2098 help
2448 Enable this option to test the rhas 2099 Enable this option to test the rhashtable functions at boot.
2449 2100
2450 If unsure, say N. 2101 If unsure, say N.
2451 2102
>> 2103 config TEST_HASH
>> 2104 tristate "Perform selftest on hash functions"
>> 2105 help
>> 2106 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 2107 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 2108 hash functions on boot (or module load).
>> 2109
>> 2110 This is intended to help people writing architecture-specific
>> 2111 optimized versions. If unsure, say N.
>> 2112
2452 config TEST_IDA 2113 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 2114 tristate "Perform selftest on IDA functions"
2454 2115
2455 config TEST_PARMAN 2116 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 2117 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 2118 depends on PARMAN
2458 help 2119 help
2459 Enable this option to test priority 2120 Enable this option to test priority array manager on boot
2460 (or module load). 2121 (or module load).
2461 2122
2462 If unsure, say N. 2123 If unsure, say N.
2463 2124
2464 config TEST_IRQ_TIMINGS 2125 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 2126 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 2127 depends on IRQ_TIMINGS
2467 help 2128 help
2468 Enable this option to test the irq 2129 Enable this option to test the irq timings code on boot.
2469 2130
2470 If unsure, say N. 2131 If unsure, say N.
2471 2132
2472 config TEST_LKM 2133 config TEST_LKM
2473 tristate "Test module loading with 'h 2134 tristate "Test module loading with 'hello world' module"
2474 depends on m 2135 depends on m
2475 help 2136 help
2476 This builds the "test_module" modul 2137 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 2138 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 2139 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 2140 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 2141 and will not normally be loaded by the system unless explicitly
2481 requested by name. 2142 requested by name.
2482 2143
2483 If unsure, say N. 2144 If unsure, say N.
2484 2145
2485 config TEST_BITOPS 2146 config TEST_BITOPS
2486 tristate "Test module for compilation 2147 tristate "Test module for compilation of bitops operations"
>> 2148 depends on m
2487 help 2149 help
2488 This builds the "test_bitops" modul 2150 This builds the "test_bitops" module that is much like the
2489 TEST_LKM module except that it does 2151 TEST_LKM module except that it does a basic exercise of the
2490 set/clear_bit macros and get_count_ 2152 set/clear_bit macros and get_count_order/long to make sure there are
2491 no compiler warnings from C=1 spars 2153 no compiler warnings from C=1 sparse checker or -Wextra
2492 compilations. It has no dependencie 2154 compilations. It has no dependencies and doesn't run or load unless
2493 explicitly requested by name. for 2155 explicitly requested by name. for example: modprobe test_bitops.
2494 2156
2495 If unsure, say N. 2157 If unsure, say N.
2496 2158
2497 config TEST_VMALLOC 2159 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 2160 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 2161 default n
2500 depends on MMU 2162 depends on MMU
2501 depends on m 2163 depends on m
2502 help 2164 help
2503 This builds the "test_vmalloc" modu 2165 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 2166 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 2167 subsystem can be evaluated from performance and stability point
2506 of view. 2168 of view.
2507 2169
2508 If unsure, say N. 2170 If unsure, say N.
2509 2171
>> 2172 config TEST_USER_COPY
>> 2173 tristate "Test user/kernel boundary protections"
>> 2174 depends on m
>> 2175 help
>> 2176 This builds the "test_user_copy" module that runs sanity checks
>> 2177 on the copy_to/from_user infrastructure, making sure basic
>> 2178 user/kernel boundary testing is working. If it fails to load,
>> 2179 a regression has been detected in the user/kernel memory boundary
>> 2180 protections.
>> 2181
>> 2182 If unsure, say N.
>> 2183
2510 config TEST_BPF 2184 config TEST_BPF
2511 tristate "Test BPF filter functionali 2185 tristate "Test BPF filter functionality"
2512 depends on m && NET 2186 depends on m && NET
2513 help 2187 help
2514 This builds the "test_bpf" module t 2188 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 2189 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 2190 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 2191 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 2192 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 2193 verifier used by user space verifier testsuite.
2520 2194
2521 If unsure, say N. 2195 If unsure, say N.
2522 2196
2523 config TEST_BLACKHOLE_DEV 2197 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 2198 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 2199 depends on m && NET
2526 help 2200 help
2527 This builds the "test_blackhole_dev 2201 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 2202 data path through this blackhole netdev.
2529 2203
2530 If unsure, say N. 2204 If unsure, say N.
2531 2205
2532 config FIND_BIT_BENCHMARK 2206 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 2207 tristate "Test find_bit functions"
2534 help 2208 help
2535 This builds the "test_find_bit" mod 2209 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2210 functions performance.
2537 2211
2538 If unsure, say N. 2212 If unsure, say N.
2539 2213
2540 config TEST_FIRMWARE 2214 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2215 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2216 depends on FW_LOADER
2543 help 2217 help
2544 This builds the "test_firmware" mod 2218 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2219 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2220 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2221 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2222 userspace.
2549 2223
2550 If unsure, say N. 2224 If unsure, say N.
2551 2225
2552 config TEST_SYSCTL 2226 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2227 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2228 depends on PROC_SYSCTL
2555 help 2229 help
2556 This builds the "test_sysctl" modul 2230 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2231 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2232 production knobs which might alter system functionality.
2559 2233
2560 If unsure, say N. 2234 If unsure, say N.
2561 2235
2562 config BITFIELD_KUNIT 2236 config BITFIELD_KUNIT
2563 tristate "KUnit test bitfield functio !! 2237 tristate "KUnit test bitfield functions at runtime"
2564 depends on KUNIT 2238 depends on KUNIT
2565 default KUNIT_ALL_TESTS <<
2566 help 2239 help
2567 Enable this option to test the bitf 2240 Enable this option to test the bitfield functions at boot.
2568 2241
2569 KUnit tests run during boot and out 2242 KUnit tests run during boot and output the results to the debug log
2570 in TAP format (http://testanything. 2243 in TAP format (http://testanything.org/). Only useful for kernel devs
2571 running the KUnit test harness, and 2244 running the KUnit test harness, and not intended for inclusion into a
2572 production build. 2245 production build.
2573 2246
2574 For more information on KUnit and u 2247 For more information on KUnit and unit tests in general please refer
2575 to the KUnit documentation in Docum 2248 to the KUnit documentation in Documentation/dev-tools/kunit/.
2576 2249
2577 If unsure, say N. 2250 If unsure, say N.
2578 2251
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 2252 config RESOURCE_KUNIT_TEST
2616 tristate "KUnit test for resource API !! 2253 tristate "KUnit test for resource API"
2617 depends on KUNIT 2254 depends on KUNIT
2618 default KUNIT_ALL_TESTS <<
2619 help 2255 help
2620 This builds the resource API unit t 2256 This builds the resource API unit test.
2621 Tests the logic of API provided by 2257 Tests the logic of API provided by resource.c and ioport.h.
2622 For more information on KUnit and u 2258 For more information on KUnit and unit tests in general please refer
2623 to the KUnit documentation in Docum 2259 to the KUnit documentation in Documentation/dev-tools/kunit/.
2624 2260
2625 If unsure, say N. 2261 If unsure, say N.
2626 2262
2627 config SYSCTL_KUNIT_TEST 2263 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! 2264 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629 depends on KUNIT 2265 depends on KUNIT
2630 default KUNIT_ALL_TESTS 2266 default KUNIT_ALL_TESTS
2631 help 2267 help
2632 This builds the proc sysctl unit te 2268 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2269 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2270 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2271 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2272
2637 If unsure, say N. 2273 If unsure, say N.
2638 2274
2639 config LIST_KUNIT_TEST 2275 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke 2276 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641 depends on KUNIT 2277 depends on KUNIT
2642 default KUNIT_ALL_TESTS 2278 default KUNIT_ALL_TESTS
2643 help 2279 help
2644 This builds the linked list KUnit t 2280 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2281 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2282 and associated macros.
2647 2283
2648 KUnit tests run during boot and out 2284 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything 2285 in TAP format (https://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2286 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2287 production build.
2652 2288
2653 For more information on KUnit and u 2289 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2290 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2291
2656 If unsure, say N. 2292 If unsure, say N.
2657 2293
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 2294 config LINEAR_RANGES_TEST
2672 tristate "KUnit test for linear_range 2295 tristate "KUnit test for linear_ranges"
2673 depends on KUNIT 2296 depends on KUNIT
2674 select LINEAR_RANGES 2297 select LINEAR_RANGES
2675 help 2298 help
2676 This builds the linear_ranges unit 2299 This builds the linear_ranges unit test, which runs on boot.
2677 Tests the linear_ranges logic corre 2300 Tests the linear_ranges logic correctness.
2678 For more information on KUnit and u 2301 For more information on KUnit and unit tests in general please refer
2679 to the KUnit documentation in Docum 2302 to the KUnit documentation in Documentation/dev-tools/kunit/.
2680 2303
2681 If unsure, say N. 2304 If unsure, say N.
2682 2305
2683 config CMDLINE_KUNIT_TEST 2306 config CMDLINE_KUNIT_TEST
2684 tristate "KUnit test for cmdline API" !! 2307 tristate "KUnit test for cmdline API"
2685 depends on KUNIT 2308 depends on KUNIT
2686 default KUNIT_ALL_TESTS <<
2687 help 2309 help
2688 This builds the cmdline API unit te 2310 This builds the cmdline API unit test.
2689 Tests the logic of API provided by 2311 Tests the logic of API provided by cmdline.c.
2690 For more information on KUnit and u 2312 For more information on KUnit and unit tests in general please refer
2691 to the KUnit documentation in Docum 2313 to the KUnit documentation in Documentation/dev-tools/kunit/.
2692 2314
2693 If unsure, say N. 2315 If unsure, say N.
2694 2316
2695 config BITS_TEST 2317 config BITS_TEST
2696 tristate "KUnit test for bits.h" if ! !! 2318 tristate "KUnit test for bits.h"
2697 depends on KUNIT 2319 depends on KUNIT
2698 default KUNIT_ALL_TESTS <<
2699 help 2320 help
2700 This builds the bits unit test. 2321 This builds the bits unit test.
2701 Tests the logic of macros defined i 2322 Tests the logic of macros defined in bits.h.
2702 For more information on KUnit and u 2323 For more information on KUnit and unit tests in general please refer
2703 to the KUnit documentation in Docum 2324 to the KUnit documentation in Documentation/dev-tools/kunit/.
2704 2325
2705 If unsure, say N. 2326 If unsure, say N.
2706 2327
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 2328 config TEST_UDELAY
2817 tristate "udelay test driver" 2329 tristate "udelay test driver"
2818 help 2330 help
2819 This builds the "udelay_test" modul 2331 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2332 that udelay() is working properly.
2821 2333
2822 If unsure, say N. 2334 If unsure, say N.
2823 2335
2824 config TEST_STATIC_KEYS 2336 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2337 tristate "Test static keys"
2826 depends on m 2338 depends on m
2827 help 2339 help
2828 Test the static key interfaces. 2340 Test the static key interfaces.
2829 2341
2830 If unsure, say N. 2342 If unsure, say N.
2831 2343
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 2344 config TEST_KMOD
2843 tristate "kmod stress tester" 2345 tristate "kmod stress tester"
2844 depends on m 2346 depends on m
2845 depends on NETDEVICES && NET_CORE && 2347 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2348 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 2349 select TEST_LKM
2849 select XFS_FS 2350 select XFS_FS
2850 select TUN 2351 select TUN
2851 select BTRFS_FS 2352 select BTRFS_FS
2852 help 2353 help
2853 Test the kernel's module loading me 2354 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2355 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2356 This test provides a series of tests against kmod.
2856 2357
2857 Although technically you can either 2358 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2359 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2360 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2361 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2362 module load requests, ultimately this could be fatal.
2862 2363
2863 To run tests run: 2364 To run tests run:
2864 2365
2865 tools/testing/selftests/kmod/kmod.s 2366 tools/testing/selftests/kmod/kmod.sh --help
2866 2367
2867 If unsure, say N. 2368 If unsure, say N.
2868 2369
2869 config TEST_DEBUG_VIRTUAL 2370 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2371 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2372 depends on DEBUG_VIRTUAL
2872 help 2373 help
2873 Test the kernel's ability to detect 2374 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2375 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2376 kernel's virtual address map.
2876 2377
2877 If unsure, say N. 2378 If unsure, say N.
2878 2379
2879 config TEST_MEMCAT_P 2380 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2381 tristate "Test memcat_p() helper function"
2881 help 2382 help
2882 Test the memcat_p() helper for corr 2383 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2384 pointer arrays together.
2884 2385
2885 If unsure, say N. 2386 If unsure, say N.
2886 2387
>> 2388 config TEST_LIVEPATCH
>> 2389 tristate "Test livepatching"
>> 2390 default n
>> 2391 depends on DYNAMIC_DEBUG
>> 2392 depends on LIVEPATCH
>> 2393 depends on m
>> 2394 help
>> 2395 Test kernel livepatching features for correctness. The tests will
>> 2396 load test modules that will be livepatched in various scenarios.
>> 2397
>> 2398 To run all the livepatching tests:
>> 2399
>> 2400 make -C tools/testing/selftests TARGETS=livepatch run_tests
>> 2401
>> 2402 Alternatively, individual tests may be invoked:
>> 2403
>> 2404 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2405 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2406 tools/testing/selftests/livepatch/test-shadow-vars.sh
>> 2407
>> 2408 If unsure, say N.
>> 2409
2887 config TEST_OBJAGG 2410 config TEST_OBJAGG
2888 tristate "Perform selftest on object 2411 tristate "Perform selftest on object aggreration manager"
2889 default n 2412 default n
2890 depends on OBJAGG 2413 depends on OBJAGG
2891 help 2414 help
2892 Enable this option to test object a 2415 Enable this option to test object aggregation manager on boot
2893 (or module load). 2416 (or module load).
2894 2417
>> 2418
>> 2419 config TEST_STACKINIT
>> 2420 tristate "Test level of stack variable initialization"
>> 2421 help
>> 2422 Test if the kernel is zero-initializing stack variables and
>> 2423 padding. Coverage is controlled by compiler flags,
>> 2424 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
>> 2425 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
>> 2426
>> 2427 If unsure, say N.
>> 2428
2895 config TEST_MEMINIT 2429 config TEST_MEMINIT
2896 tristate "Test heap/page initializati 2430 tristate "Test heap/page initialization"
2897 help 2431 help
2898 Test if the kernel is zero-initiali 2432 Test if the kernel is zero-initializing heap and page allocations.
2899 This can be useful to test init_on_ 2433 This can be useful to test init_on_alloc and init_on_free features.
2900 2434
2901 If unsure, say N. 2435 If unsure, say N.
2902 2436
2903 config TEST_HMM 2437 config TEST_HMM
2904 tristate "Test HMM (Heterogeneous Mem 2438 tristate "Test HMM (Heterogeneous Memory Management)"
2905 depends on TRANSPARENT_HUGEPAGE 2439 depends on TRANSPARENT_HUGEPAGE
2906 depends on DEVICE_PRIVATE 2440 depends on DEVICE_PRIVATE
2907 select HMM_MIRROR 2441 select HMM_MIRROR
2908 select MMU_NOTIFIER 2442 select MMU_NOTIFIER
2909 help 2443 help
2910 This is a pseudo device driver sole 2444 This is a pseudo device driver solely for testing HMM.
2911 Say M here if you want to build the 2445 Say M here if you want to build the HMM test module.
2912 Doing so will allow you to run tool 2446 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913 2447
2914 If unsure, say N. 2448 If unsure, say N.
2915 2449
2916 config TEST_FREE_PAGES 2450 config TEST_FREE_PAGES
2917 tristate "Test freeing pages" 2451 tristate "Test freeing pages"
2918 help 2452 help
2919 Test that a memory leak does not oc 2453 Test that a memory leak does not occur due to a race between
2920 freeing a block of pages and a spec 2454 freeing a block of pages and a speculative page reference.
2921 Loading this module is safe if your 2455 Loading this module is safe if your kernel has the bug fixed.
2922 If the bug is not fixed, it will le 2456 If the bug is not fixed, it will leak gigabytes of memory and
2923 probably OOM your system. 2457 probably OOM your system.
2924 2458
2925 config TEST_FPU 2459 config TEST_FPU
2926 tristate "Test floating point operati 2460 tristate "Test floating point operations in kernel space"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2461 depends on X86 && !KCOV_INSTRUMENT_ALL
2928 help 2462 help
2929 Enable this option to add /sys/kern 2463 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930 which will trigger a sequence of fl 2464 which will trigger a sequence of floating point operations. This is used
2931 for self-testing floating point con 2465 for self-testing floating point control register setting in
2932 kernel_fpu_begin(). 2466 kernel_fpu_begin().
2933 2467
2934 If unsure, say N. 2468 If unsure, say N.
2935 2469
2936 config TEST_CLOCKSOURCE_WATCHDOG <<
2937 tristate "Test clocksource watchdog i <<
2938 depends on CLOCKSOURCE_WATCHDOG <<
2939 help <<
2940 Enable this option to create a kern <<
2941 a test of the clocksource watchdog. <<
2942 via modprobe or insmod in which cas <<
2943 loaded, or it may be built in, in w <<
2944 shortly after boot. <<
2945 <<
2946 If unsure, say N. <<
2947 <<
2948 config TEST_OBJPOOL <<
2949 tristate "Test module for correctness <<
2950 default n <<
2951 depends on m && DEBUG_KERNEL <<
2952 help <<
2953 This builds the "test_objpool" modu <<
2954 correctness verification and concur <<
2955 allocation and reclamation. <<
2956 <<
2957 If unsure, say N. <<
2958 <<
2959 endif # RUNTIME_TESTING_MENU 2470 endif # RUNTIME_TESTING_MENU
2960 2471
2961 config ARCH_USE_MEMTEST <<
2962 bool <<
2963 help <<
2964 An architecture should select this <<
2965 during boot process. <<
2966 <<
2967 config MEMTEST 2472 config MEMTEST
2968 bool "Memtest" 2473 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST <<
2970 help 2474 help
2971 This option adds a kernel parameter 2475 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. !! 2476 to be set.
2973 memtest=0, mean disabled; -- 2477 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2478 memtest=1, mean do 1 test pattern;
2975 ... 2479 ...
2976 memtest=17, mean do 17 test p 2480 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2481 If you are unsure how to answer this question, answer N.
2978 2482
2979 2483
2980 2484
2981 config HYPERV_TESTING 2485 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2486 bool "Microsoft Hyper-V driver testing"
2983 default n 2487 default n
2984 depends on HYPERV && DEBUG_FS 2488 depends on HYPERV && DEBUG_FS
2985 help 2489 help
2986 Select this option to enable Hyper- 2490 Select this option to enable Hyper-V vmbus testing.
2987 2491
2988 endmenu # "Kernel Testing and Coverage" 2492 endmenu # "Kernel Testing and Coverage"
2989 2493
2990 menu "Rust hacking" !! 2494 source "Documentation/Kconfig"
2991 <<
2992 config RUST_DEBUG_ASSERTIONS <<
2993 bool "Debug assertions" <<
2994 depends on RUST <<
2995 help <<
2996 Enables rustc's `-Cdebug-assertions <<
2997 <<
2998 This flag lets you turn `cfg(debug_ <<
2999 compilation on or off. This can be <<
3000 code in development but not in prod <<
3001 the behavior of the standard librar <<
3002 <<
3003 Note that this will apply to all Ru <<
3004 <<
3005 If unsure, say N. <<
3006 <<
3007 config RUST_OVERFLOW_CHECKS <<
3008 bool "Overflow checks" <<
3009 default y <<
3010 depends on RUST <<
3011 help <<
3012 Enables rustc's `-Coverflow-checks` <<
3013 <<
3014 This flag allows you to control the <<
3015 overflow. When overflow-checks are <<
3016 on overflow. <<
3017 <<
3018 Note that this will apply to all Ru <<
3019 <<
3020 If unsure, say Y. <<
3021 <<
3022 config RUST_BUILD_ASSERT_ALLOW <<
3023 bool "Allow unoptimized build-time as <<
3024 depends on RUST <<
3025 help <<
3026 Controls how are `build_error!` and <<
3027 <<
3028 If calls to them exist in the binar <<
3029 or that the optimizer failed to ver <<
3030 <<
3031 This should not happen, thus by def <<
3032 as an escape hatch, you can choose <<
3033 and let the check be carried at run <<
3034 the check fails). <<
3035 <<
3036 If unsure, say N. <<
3037 <<
3038 config RUST_KERNEL_DOCTESTS <<
3039 bool "Doctests for the `kernel` crate <<
3040 depends on RUST && KUNIT=y <<
3041 default KUNIT_ALL_TESTS <<
3042 help <<
3043 This builds the documentation tests <<
3044 as KUnit tests. <<
3045 <<
3046 For more information on KUnit and u <<
3047 please refer to the KUnit documenta <<
3048 <<
3049 If unsure, say N. <<
3050 <<
3051 endmenu # "Rust" <<
3052 2495
3053 endmenu # Kernel hacking 2496 endmenu # Kernel hacking
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.