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 choice
>> 260 prompt "DWARF version"
>> 261 help
>> 262 Which version of DWARF debug info to emit.
>> 263
>> 264 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
>> 265 bool "Rely on the toolchain's implicit default DWARF version"
>> 266 help
>> 267 The implicit default version of DWARF debug info produced by a
>> 268 toolchain changes over time.
>> 269
>> 270 This can break consumers of the debug info that haven't upgraded to
>> 271 support newer revisions, and prevent testing newer versions, but
>> 272 those should be less common scenarios.
>> 273
>> 274 If unsure, say Y.
>> 275
>> 276 config DEBUG_INFO_DWARF4
>> 277 bool "Generate DWARF Version 4 debuginfo"
>> 278 help
>> 279 Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
>> 280
>> 281 If you have consumers of DWARF debug info that are not ready for
>> 282 newer revisions of DWARF, you may wish to choose this or have your
>> 283 config select this.
>> 284
>> 285 config DEBUG_INFO_DWARF5
>> 286 bool "Generate DWARF Version 5 debuginfo"
>> 287 depends on GCC_VERSION >= 50000 || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
>> 288 depends on !DEBUG_INFO_BTF
>> 289 help
>> 290 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
>> 291 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
>> 292 draft features until 7.0), and gdb 8.0+.
>> 293
>> 294 Changes to the structure of debug info in Version 5 allow for around
>> 295 15-18% savings in resulting image and debug info section sizes as
>> 296 compared to DWARF Version 4. DWARF Version 5 standardizes previous
>> 297 extensions such as accelerators for symbol indexing and the format
>> 298 for fission (.dwo/.dwp) files. Users may not want to select this
>> 299 config if they rely on tooling that has not yet been updated to
>> 300 support DWARF Version 5.
>> 301
>> 302 endchoice # "DWARF version"
>> 303
377 config DEBUG_INFO_BTF 304 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 305 bool "Generate BTF typeinfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG 306 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || C 307 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 308 help
386 Generate deduplicated BTF type infor 309 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 310 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 311 DWARF type info into equivalent deduplicated BTF type info.
389 312
390 config PAHOLE_HAS_SPLIT_BTF 313 config PAHOLE_HAS_SPLIT_BTF
391 def_bool PAHOLE_VERSION >= 119 !! 314 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. <<
409 315
410 config DEBUG_INFO_BTF_MODULES 316 config DEBUG_INFO_BTF_MODULES
411 bool "Generate BTF type information fo !! 317 def_bool y
412 default y <<
413 depends on DEBUG_INFO_BTF && MODULES & 318 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
414 help 319 help
415 Generate compact split BTF type info 320 Generate compact split BTF type information for kernel modules.
416 321
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 322 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 323 bool "Provide GDB scripts for kernel debugging"
429 help 324 help
430 This creates the required links to G 325 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 326 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 327 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 328 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 329 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 330 for further details.
436 331
437 endif # DEBUG_INFO 332 endif # DEBUG_INFO
438 333
439 config FRAME_WARN 334 config FRAME_WARN
440 int "Warn for stack frames larger than 335 int "Warn for stack frames larger than"
441 range 0 8192 336 range 0 8192
442 default 0 if KMSAN <<
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 337 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC !! 338 default 1280 if (!64BIT && PARISC)
445 default 1536 if (!64BIT && XTENSA) !! 339 default 1024 if (!64BIT && !PARISC)
446 default 1280 if KASAN && !64BIT <<
447 default 1024 if !64BIT <<
448 default 2048 if 64BIT 340 default 2048 if 64BIT
449 help 341 help
450 Tell the compiler to warn at build t !! 342 Tell gcc to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 343 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 344 Setting it to 0 disables the warning.
453 345
454 config STRIP_ASM_SYMS 346 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 347 bool "Strip assembler-generated symbols during link"
456 default n 348 default n
457 help 349 help
458 Strip internal assembler-generated s 350 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 351 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 352 get_wchan() and suchlike.
461 353
462 config READABLE_ASM 354 config READABLE_ASM
463 bool "Generate readable assembler code 355 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 356 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC <<
466 help 357 help
467 Disable some compiler optimizations 358 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 359 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 360 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 361 sane.
471 362
472 config HEADERS_INSTALL 363 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 364 bool "Install uapi headers to usr/include"
474 depends on !UML 365 depends on !UML
475 help 366 help
476 This option will install uapi header 367 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 368 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 369 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 370 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 371 as uapi header sanity checks.
481 372
482 config DEBUG_SECTION_MISMATCH 373 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 374 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC <<
485 help 375 help
486 The section mismatch analysis checks 376 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 377 references from one section to another section.
488 During linktime or runtime, some sec 378 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 379 any use of code/data previously in these sections would
490 most likely result in an oops. 380 most likely result in an oops.
491 In the code, functions and variables 381 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 382 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 383 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 384 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 385 kernel build, and enabling this option causes the following
496 additional step to occur: 386 additional step to occur:
497 - Add the option -fno-inline-functio 387 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 388 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 389 function, we would lose the section information and thus
500 the analysis would not catch the i 390 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 391 This option tells gcc to inline less (but it does result in
502 a larger kernel). 392 a larger kernel).
503 393
504 config SECTION_MISMATCH_WARN_ONLY 394 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 395 bool "Make section mismatch errors non-fatal"
506 default y 396 default y
507 help 397 help
508 If you say N here, the build process 398 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 399 section mismatch, instead of just throwing warnings.
510 400
511 If unsure, say Y. 401 If unsure, say Y.
512 402
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B !! 403 config DEBUG_FORCE_FUNCTION_ALIGN_32B
514 bool "Force all function address 64B a !! 404 bool "Force all function address 32B aligned" if EXPERT
515 depends on EXPERT && (X86_64 || ARM64 <<
516 select FUNCTION_ALIGNMENT_64B <<
517 help 405 help
518 There are cases that a commit from o 406 There are cases that a commit from one domain changes the function
519 address alignment of other domains, 407 address alignment of other domains, and cause magic performance
520 bump (regression or improvement). En 408 bump (regression or improvement). Enable this option will help to
521 verify if the bump is caused by func 409 verify if the bump is caused by function alignment changes, while
522 it will slightly increase the kernel 410 it will slightly increase the kernel size and affect icache usage.
523 411
524 It is mainly for debug and performan 412 It is mainly for debug and performance tuning use.
525 413
526 # 414 #
527 # Select this config option from the architect 415 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 416 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 417 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 418 #
531 config ARCH_WANT_FRAME_POINTERS 419 config ARCH_WANT_FRAME_POINTERS
532 bool 420 bool
533 421
534 config FRAME_POINTER 422 config FRAME_POINTER
535 bool "Compile the kernel with frame po 423 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 424 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 425 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 426 help
539 If you say Y here the resulting kern 427 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 428 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 429 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 430
543 config OBJTOOL <<
544 bool <<
545 <<
546 config STACK_VALIDATION 431 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 432 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN !! 433 depends on HAVE_STACK_VALIDATION
549 select OBJTOOL <<
550 default n 434 default n
551 help 435 help
552 Validate frame pointer rules at comp !! 436 Add compile-time checks to validate stack metadata, including frame
553 runtime stack traces are more reliab !! 437 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
>> 438 that runtime stack traces are more reliable.
>> 439
>> 440 This is also a prerequisite for generation of ORC unwind data, which
>> 441 is needed for CONFIG_UNWINDER_ORC.
554 442
555 For more information, see 443 For more information, see
556 tools/objtool/Documentation/objtool. !! 444 tools/objtool/Documentation/stack-validation.txt.
557 445
558 config NOINSTR_VALIDATION !! 446 config VMLINUX_VALIDATION
559 bool 447 bool
560 depends on HAVE_NOINSTR_VALIDATION && !! 448 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
561 select OBJTOOL <<
562 default y 449 default y
563 450
564 config VMLINUX_MAP 451 config VMLINUX_MAP
565 bool "Generate vmlinux.map file when l 452 bool "Generate vmlinux.map file when linking"
566 depends on EXPERT 453 depends on EXPERT
567 help 454 help
568 Selecting this option will pass "-Ma 455 Selecting this option will pass "-Map=vmlinux.map" to ld
569 when linking vmlinux. That file can 456 when linking vmlinux. That file can be useful for verifying
570 and debugging magic section games, a 457 and debugging magic section games, and for seeing which
571 pieces of code get eliminated with 458 pieces of code get eliminated with
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION 459 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
573 460
574 config DEBUG_FORCE_WEAK_PER_CPU 461 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 462 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 463 depends on DEBUG_KERNEL
577 help 464 help
578 s390 and alpha require percpu variab 465 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 466 defined weak to work around addressing range issue which
580 puts the following two restrictions 467 puts the following two restrictions on percpu variable
581 definitions. 468 definitions.
582 469
583 1. percpu symbols must be unique whe 470 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 471 2. percpu variables can't be defined inside a function
585 472
586 To ensure that generic code follows 473 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 474 option forces all percpu variables to be defined as weak.
588 475
589 endmenu # "Compiler options" 476 endmenu # "Compiler options"
590 477
591 menu "Generic Kernel Debugging Instruments" 478 menu "Generic Kernel Debugging Instruments"
592 479
593 config MAGIC_SYSRQ 480 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 481 bool "Magic SysRq key"
595 depends on !UML 482 depends on !UML
596 help 483 help
597 If you say Y here, you will have som 484 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 485 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 486 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 487 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 488 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 489 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 490 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 491 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 492 Don't say Y unless you really know what this hack does.
606 493
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 494 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 495 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 496 depends on MAGIC_SYSRQ
610 default 0x1 497 default 0x1
611 help 498 help
612 Specifies which SysRq key functions 499 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 500 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 501 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 502
616 config MAGIC_SYSRQ_SERIAL 503 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 504 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 505 depends on MAGIC_SYSRQ
619 default y 506 default y
620 help 507 help
621 Many embedded boards have a disconne 508 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 509 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 510 This option allows you to decide whether you want to enable the
624 magic SysRq key. 511 magic SysRq key.
625 512
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE 513 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627 string "Char sequence that enables mag 514 string "Char sequence that enables magic SysRq over serial"
628 depends on MAGIC_SYSRQ_SERIAL 515 depends on MAGIC_SYSRQ_SERIAL
629 default "" 516 default ""
630 help 517 help
631 Specifies a sequence of characters t 518 Specifies a sequence of characters that can follow BREAK to enable
632 SysRq on a serial console. 519 SysRq on a serial console.
633 520
634 If unsure, leave an empty string and 521 If unsure, leave an empty string and the option will not be enabled.
635 522
636 config DEBUG_FS 523 config DEBUG_FS
637 bool "Debug Filesystem" 524 bool "Debug Filesystem"
638 help 525 help
639 debugfs is a virtual file system tha 526 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 527 debugging files into. Enable this option to be able to read and
641 write to these files. 528 write to these files.
642 529
643 For detailed documentation on the de 530 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 531 Documentation/filesystems/.
645 532
646 If unsure, say N. 533 If unsure, say N.
647 534
648 choice 535 choice
649 prompt "Debugfs default access" 536 prompt "Debugfs default access"
650 depends on DEBUG_FS 537 depends on DEBUG_FS
651 default DEBUG_FS_ALLOW_ALL 538 default DEBUG_FS_ALLOW_ALL
652 help 539 help
653 This selects the default access rest 540 This selects the default access restrictions for debugfs.
654 It can be overridden with kernel com 541 It can be overridden with kernel command line option
655 debugfs=[on,no-mount,off]. The restr 542 debugfs=[on,no-mount,off]. The restrictions apply for API access
656 and filesystem registration. 543 and filesystem registration.
657 544
658 config DEBUG_FS_ALLOW_ALL 545 config DEBUG_FS_ALLOW_ALL
659 bool "Access normal" 546 bool "Access normal"
660 help 547 help
661 No restrictions apply. Both API and 548 No restrictions apply. Both API and filesystem registration
662 is on. This is the normal default op 549 is on. This is the normal default operation.
663 550
664 config DEBUG_FS_DISALLOW_MOUNT 551 config DEBUG_FS_DISALLOW_MOUNT
665 bool "Do not register debugfs as files 552 bool "Do not register debugfs as filesystem"
666 help 553 help
667 The API is open but filesystem is no 554 The API is open but filesystem is not loaded. Clients can still do
668 their work and read with debug tools 555 their work and read with debug tools that do not need
669 debugfs filesystem. 556 debugfs filesystem.
670 557
671 config DEBUG_FS_ALLOW_NONE 558 config DEBUG_FS_ALLOW_NONE
672 bool "No access" 559 bool "No access"
673 help 560 help
674 Access is off. Clients get -PERM whe 561 Access is off. Clients get -PERM when trying to create nodes in
675 debugfs tree and debugfs is not regi 562 debugfs tree and debugfs is not registered as a filesystem.
676 Client can then back-off or continue 563 Client can then back-off or continue without debugfs access.
677 564
678 endchoice 565 endchoice
679 566
680 source "lib/Kconfig.kgdb" 567 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan" 568 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" 569 source "lib/Kconfig.kcsan"
683 570
684 endmenu 571 endmenu
685 572
686 menu "Networking Debugging" !! 573 config DEBUG_KERNEL
>> 574 bool "Kernel debugging"
>> 575 help
>> 576 Say Y here if you are developing drivers or trying to debug and
>> 577 identify kernel problems.
687 578
688 source "net/Kconfig.debug" !! 579 config DEBUG_MISC
>> 580 bool "Miscellaneous debug code"
>> 581 default DEBUG_KERNEL
>> 582 depends on DEBUG_KERNEL
>> 583 help
>> 584 Say Y here if you need to enable miscellaneous debug code that should
>> 585 be under a more specific debug option but isn't.
689 586
690 endmenu # "Networking Debugging" <<
691 587
692 menu "Memory Debugging" 588 menu "Memory Debugging"
693 589
694 source "mm/Kconfig.debug" 590 source "mm/Kconfig.debug"
695 591
696 config DEBUG_OBJECTS 592 config DEBUG_OBJECTS
697 bool "Debug object operations" 593 bool "Debug object operations"
698 depends on DEBUG_KERNEL 594 depends on DEBUG_KERNEL
699 help 595 help
700 If you say Y here, additional code w 596 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 597 kernel to track the life time of various objects and validate
702 the operations on those objects. 598 the operations on those objects.
703 599
704 config DEBUG_OBJECTS_SELFTEST 600 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 601 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 602 depends on DEBUG_OBJECTS
707 help 603 help
708 This enables the selftest of the obj 604 This enables the selftest of the object debug code.
709 605
710 config DEBUG_OBJECTS_FREE 606 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 607 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 608 depends on DEBUG_OBJECTS
713 help 609 help
714 This enables checks whether a k/v fr 610 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 611 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 612 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 613 much slower.
718 614
719 config DEBUG_OBJECTS_TIMERS 615 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 616 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 617 depends on DEBUG_OBJECTS
722 help 618 help
723 If you say Y here, additional code w 619 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 620 timer routines to track the life time of timer objects and
725 validate the timer operations. 621 validate the timer operations.
726 622
727 config DEBUG_OBJECTS_WORK 623 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 624 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 625 depends on DEBUG_OBJECTS
730 help 626 help
731 If you say Y here, additional code w 627 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 628 work queue routines to track the life time of work objects and
733 validate the work operations. 629 validate the work operations.
734 630
735 config DEBUG_OBJECTS_RCU_HEAD 631 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 632 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 633 depends on DEBUG_OBJECTS
738 help 634 help
739 Enable this to turn on debugging of 635 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 636
741 config DEBUG_OBJECTS_PERCPU_COUNTER 637 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 638 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 639 depends on DEBUG_OBJECTS
744 help 640 help
745 If you say Y here, additional code w 641 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 642 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 643 objects and validate the percpu counter operations.
748 644
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 645 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 646 int "debug_objects bootup default value (0-1)"
751 range 0 1 647 range 0 1
752 default "1" 648 default "1"
753 depends on DEBUG_OBJECTS 649 depends on DEBUG_OBJECTS
754 help 650 help
755 Debug objects boot parameter default 651 Debug objects boot parameter default value
756 652
757 config SHRINKER_DEBUG !! 653 config DEBUG_SLAB
758 bool "Enable shrinker debugging suppor !! 654 bool "Debug slab memory allocations"
759 depends on DEBUG_FS !! 655 depends on DEBUG_KERNEL && SLAB
>> 656 help
>> 657 Say Y here to have the kernel do limited verification on memory
>> 658 allocation as well as poisoning memory on free to catch use of freed
>> 659 memory. This can make kmalloc/kfree-intensive workloads much slower.
>> 660
>> 661 config SLUB_DEBUG_ON
>> 662 bool "SLUB debugging on by default"
>> 663 depends on SLUB && SLUB_DEBUG
>> 664 default n
>> 665 help
>> 666 Boot with debugging on by default. SLUB boots by default with
>> 667 the runtime debug capabilities switched off. Enabling this is
>> 668 equivalent to specifying the "slub_debug" parameter on boot.
>> 669 There is no support for more fine grained debug control like
>> 670 possible with slub_debug=xxx. SLUB debugging may be switched
>> 671 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
>> 672 "slub_debug=-".
>> 673
>> 674 config SLUB_STATS
>> 675 default n
>> 676 bool "Enable SLUB performance statistics"
>> 677 depends on SLUB && SYSFS
>> 678 help
>> 679 SLUB statistics are useful to debug SLUBs allocation behavior in
>> 680 order find ways to optimize the allocator. This should never be
>> 681 enabled for production use since keeping statistics slows down
>> 682 the allocator by a few percentage points. The slabinfo command
>> 683 supports the determination of the most active slabs to figure
>> 684 out which slabs are relevant to a particular load.
>> 685 Try running: slabinfo -DA
>> 686
>> 687 config HAVE_DEBUG_KMEMLEAK
>> 688 bool
>> 689
>> 690 config DEBUG_KMEMLEAK
>> 691 bool "Kernel memory leak detector"
>> 692 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
>> 693 select DEBUG_FS
>> 694 select STACKTRACE if STACKTRACE_SUPPORT
>> 695 select KALLSYMS
>> 696 select CRC32
>> 697 help
>> 698 Say Y here if you want to enable the memory leak
>> 699 detector. The memory allocation/freeing is traced in a way
>> 700 similar to the Boehm's conservative garbage collector, the
>> 701 difference being that the orphan objects are not freed but
>> 702 only shown in /sys/kernel/debug/kmemleak. Enabling this
>> 703 feature will introduce an overhead to memory
>> 704 allocations. See Documentation/dev-tools/kmemleak.rst for more
>> 705 details.
>> 706
>> 707 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
>> 708 of finding leaks due to the slab objects poisoning.
>> 709
>> 710 In order to access the kmemleak file, debugfs needs to be
>> 711 mounted (usually at /sys/kernel/debug).
>> 712
>> 713 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
>> 714 int "Kmemleak memory pool size"
>> 715 depends on DEBUG_KMEMLEAK
>> 716 range 200 1000000
>> 717 default 16000
>> 718 help
>> 719 Kmemleak must track all the memory allocations to avoid
>> 720 reporting false positives. Since memory may be allocated or
>> 721 freed before kmemleak is fully initialised, use a static pool
>> 722 of metadata objects to track such callbacks. After kmemleak is
>> 723 fully initialised, this memory pool acts as an emergency one
>> 724 if slab allocations fail.
>> 725
>> 726 config DEBUG_KMEMLEAK_TEST
>> 727 tristate "Simple test for the kernel memory leak detector"
>> 728 depends on DEBUG_KMEMLEAK && m
>> 729 help
>> 730 This option enables a module that explicitly leaks memory.
>> 731
>> 732 If unsure, say N.
>> 733
>> 734 config DEBUG_KMEMLEAK_DEFAULT_OFF
>> 735 bool "Default kmemleak to off"
>> 736 depends on DEBUG_KMEMLEAK
>> 737 help
>> 738 Say Y here to disable kmemleak by default. It can then be enabled
>> 739 on the command line via kmemleak=on.
>> 740
>> 741 config DEBUG_KMEMLEAK_AUTO_SCAN
>> 742 bool "Enable kmemleak auto scan thread on boot up"
>> 743 default y
>> 744 depends on DEBUG_KMEMLEAK
760 help 745 help
761 Say Y to enable the shrinker debugfs !! 746 Depending on the cpu, kmemleak scan may be cpu intensive and can
762 visibility into the kernel memory sh !! 747 stall user tasks at times. This option enables/disables automatic
763 Disable it to avoid an extra memory !! 748 kmemleak scan at boot up.
>> 749
>> 750 Say N here to disable kmemleak auto scan thread to stop automatic
>> 751 scanning. Disabling this option disables automatic reporting of
>> 752 memory leaks.
>> 753
>> 754 If unsure, say Y.
764 755
765 config DEBUG_STACK_USAGE 756 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 757 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 758 depends on DEBUG_KERNEL && !IA64
768 help 759 help
769 Enables the display of the minimum a 760 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 761 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 <<
773 762
774 This option will slow down process c 763 This option will slow down process creation somewhat.
775 764
776 config SCHED_STACK_END_CHECK 765 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 766 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 767 depends on DEBUG_KERNEL
779 default n 768 default n
780 help 769 help
781 This option checks for a stack overr 770 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 771 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 772 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 773 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 774 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 775 is examined. The runtime overhead introduced is minimal.
787 776
788 config ARCH_HAS_DEBUG_VM_PGTABLE 777 config ARCH_HAS_DEBUG_VM_PGTABLE
789 bool 778 bool
790 help 779 help
791 An architecture should select this w 780 An architecture should select this when it can successfully
792 build and run DEBUG_VM_PGTABLE. 781 build and run DEBUG_VM_PGTABLE.
793 782
794 config DEBUG_VM_IRQSOFF <<
795 def_bool DEBUG_VM && !PREEMPT_RT <<
796 <<
797 config DEBUG_VM 783 config DEBUG_VM
798 bool "Debug VM" 784 bool "Debug VM"
799 depends on DEBUG_KERNEL 785 depends on DEBUG_KERNEL
800 help 786 help
801 Enable this to turn on extended chec 787 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 788 that may impact performance.
803 789
804 If unsure, say N. 790 If unsure, say N.
805 791
806 config DEBUG_VM_SHOOT_LAZIES !! 792 config DEBUG_VM_VMACACHE
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp !! 793 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 794 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE <<
820 help 795 help
821 Enable VM maple tree debugging infor !! 796 Enable this to turn on VMA caching debug information. Doing so
>> 797 can cause significant overhead, so only enable it in non-production
>> 798 environments.
822 799
823 If unsure, say N. 800 If unsure, say N.
824 801
825 config DEBUG_VM_RB 802 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 803 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 804 depends on DEBUG_VM
828 help 805 help
829 Enable VM red-black tree debugging i 806 Enable VM red-black tree debugging information and extra validations.
830 807
831 If unsure, say N. 808 If unsure, say N.
832 809
833 config DEBUG_VM_PGFLAGS 810 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 811 bool "Debug page-flags operations"
835 depends on DEBUG_VM 812 depends on DEBUG_VM
836 help 813 help
837 Enables extra validation on page fla 814 Enables extra validation on page flags operations.
838 815
839 If unsure, say N. 816 If unsure, say N.
840 817
841 config DEBUG_VM_PGTABLE 818 config DEBUG_VM_PGTABLE
842 bool "Debug arch page table for semant 819 bool "Debug arch page table for semantics compliance"
843 depends on MMU 820 depends on MMU
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE 821 depends on ARCH_HAS_DEBUG_VM_PGTABLE
845 default y if DEBUG_VM 822 default y if DEBUG_VM
846 help 823 help
847 This option provides a debug method 824 This option provides a debug method which can be used to test
848 architecture page table helper funct 825 architecture page table helper functions on various platforms in
849 verifying if they comply with expect 826 verifying if they comply with expected generic MM semantics. This
850 will help architecture code in makin 827 will help architecture code in making sure that any changes or
851 new additions of these helpers still 828 new additions of these helpers still conform to expected
852 semantics of the generic MM. Platfor 829 semantics of the generic MM. Platforms will have to opt in for
853 this through ARCH_HAS_DEBUG_VM_PGTAB 830 this through ARCH_HAS_DEBUG_VM_PGTABLE.
854 831
855 If unsure, say N. 832 If unsure, say N.
856 833
857 config ARCH_HAS_DEBUG_VIRTUAL 834 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 835 bool
859 836
860 config DEBUG_VIRTUAL 837 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 838 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 839 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 840 help
864 Enable some costly sanity checks in 841 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 842 catch mistakes with virt_to_page() and friends.
866 843
867 If unsure, say N. 844 If unsure, say N.
868 845
869 config DEBUG_NOMMU_REGIONS 846 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 847 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 848 depends on DEBUG_KERNEL && !MMU
872 help 849 help
873 This option causes the global tree o 850 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 851 regions to be regularly checked for invalid topology.
875 852
876 config DEBUG_MEMORY_INIT 853 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 854 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 855 default !EXPERT
879 help 856 help
880 Enable this for additional checks du 857 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 858 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 859 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 860 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 861 on the mminit_loglevel= command-line option.
885 862
886 If unsure, say Y 863 If unsure, say Y
887 864
888 config MEMORY_NOTIFIER_ERROR_INJECT 865 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 866 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ !! 867 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
891 help 868 help
892 This option provides the ability to 869 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 870 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 871 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 872
896 If the notifier call chain should be 873 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 874 notified, write the error code to "actions/<notifier event>/error".
898 875
899 Example: Inject memory hotplug offli 876 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 877
901 # cd /sys/kernel/debug/notifier-erro 878 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 879 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 880 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 881 bash: echo: write error: Cannot allocate memory
905 882
906 To compile this code as a module, ch 883 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 884 be called memory-notifier-error-inject.
908 885
909 If unsure, say N. 886 If unsure, say N.
910 887
911 config DEBUG_PER_CPU_MAPS 888 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 889 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 890 depends on DEBUG_KERNEL
914 depends on SMP 891 depends on SMP
915 help 892 help
916 Say Y to verify that the per_cpu map 893 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 894 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 895 and decreases performance.
919 896
920 Say N if unsure. 897 Say N if unsure.
921 898
922 config DEBUG_KMAP_LOCAL 899 config DEBUG_KMAP_LOCAL
923 bool "Debug kmap_local temporary mappi 900 bool "Debug kmap_local temporary mappings"
924 depends on DEBUG_KERNEL && KMAP_LOCAL 901 depends on DEBUG_KERNEL && KMAP_LOCAL
925 help 902 help
926 This option enables additional error 903 This option enables additional error checking for the kmap_local
927 infrastructure. Disable for product 904 infrastructure. Disable for production use.
928 905
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP 906 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
930 bool 907 bool
931 908
932 config DEBUG_KMAP_LOCAL_FORCE_MAP 909 config DEBUG_KMAP_LOCAL_FORCE_MAP
933 bool "Enforce kmap_local temporary map 910 bool "Enforce kmap_local temporary mappings"
934 depends on DEBUG_KERNEL && ARCH_SUPPOR 911 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935 select KMAP_LOCAL 912 select KMAP_LOCAL
936 select DEBUG_KMAP_LOCAL 913 select DEBUG_KMAP_LOCAL
937 help 914 help
938 This option enforces temporary mappi 915 This option enforces temporary mappings through the kmap_local
939 mechanism for non-highmem pages and 916 mechanism for non-highmem pages and on non-highmem systems.
940 Disable this for production systems! 917 Disable this for production systems!
941 918
942 config DEBUG_HIGHMEM 919 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 920 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 921 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A 922 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
946 select DEBUG_KMAP_LOCAL 923 select DEBUG_KMAP_LOCAL
947 help 924 help
948 This option enables additional error 925 This option enables additional error checking for high memory
949 systems. Disable for production sys 926 systems. Disable for production systems.
950 927
951 config HAVE_DEBUG_STACKOVERFLOW 928 config HAVE_DEBUG_STACKOVERFLOW
952 bool 929 bool
953 930
954 config DEBUG_STACKOVERFLOW 931 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 932 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 933 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help 934 help
958 Say Y here if you want to check for 935 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 936 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 937 option will show detailed messages if free stack space drops
961 below a certain limit. 938 below a certain limit.
962 939
963 These kinds of bugs usually occur wh 940 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 941 kernel get too deep, especially when interrupts are
965 involved. 942 involved.
966 943
967 Use this in cases where you see appa 944 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 945 corruption, especially if it appears in 'struct thread_info'
969 946
970 If in doubt, say "N". 947 If in doubt, say "N".
971 948
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" 949 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" 950 source "lib/Kconfig.kfence"
1005 source "lib/Kconfig.kmsan" <<
1006 951
1007 endmenu # "Memory Debugging" 952 endmenu # "Memory Debugging"
1008 953
1009 config DEBUG_SHIRQ 954 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 955 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 956 depends on DEBUG_KERNEL
1012 help 957 help
1013 Enable this to generate a spurious 958 Enable this to generate a spurious interrupt just before a shared
1014 interrupt handler is deregistered ( 959 interrupt handler is deregistered (generating one when registering
1015 is currently disabled). Drivers nee 960 is currently disabled). Drivers need to handle this correctly. Some
1016 don't and need to be caught. 961 don't and need to be caught.
1017 962
1018 menu "Debug Oops, Lockups and Hangs" 963 menu "Debug Oops, Lockups and Hangs"
1019 964
1020 config PANIC_ON_OOPS 965 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 966 bool "Panic on Oops"
1022 help 967 help
1023 Say Y here to enable the kernel to 968 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 969 has the same effect as setting oops=panic on the kernel command
1025 line. 970 line.
1026 971
1027 This feature is useful to ensure th 972 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 973 anything erroneous after an oops which could result in data
1029 corruption or other issues. 974 corruption or other issues.
1030 975
1031 Say N if unsure. 976 Say N if unsure.
1032 977
1033 config PANIC_ON_OOPS_VALUE 978 config PANIC_ON_OOPS_VALUE
1034 int 979 int
1035 range 0 1 980 range 0 1
1036 default 0 if !PANIC_ON_OOPS 981 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 982 default 1 if PANIC_ON_OOPS
1038 983
1039 config PANIC_TIMEOUT 984 config PANIC_TIMEOUT
1040 int "panic timeout" 985 int "panic timeout"
1041 default 0 986 default 0
1042 help 987 help
1043 Set the timeout value (in seconds) 988 Set the timeout value (in seconds) until a reboot occurs when
1044 the kernel panics. If n = 0, then w 989 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 990 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 991 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 992
1050 config LOCKUP_DETECTOR 993 config LOCKUP_DETECTOR
1051 bool 994 bool
1052 995
1053 config SOFTLOCKUP_DETECTOR 996 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 997 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 998 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 999 select LOCKUP_DETECTOR
1057 help 1000 help
1058 Say Y here to enable the kernel to 1001 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 1002 soft lockups.
1060 1003
1061 Softlockups are bugs that cause the 1004 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 1005 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 1006 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 1007 detection and the system will stay locked up.
1065 1008
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 1009 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 1010 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 1011 depends on SOFTLOCKUP_DETECTOR
1083 help 1012 help
1084 Say Y here to enable the kernel to 1013 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 1014 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 1015 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 1016 sysctl), without giving other tasks a chance to run.
1088 1017
1089 The panic can be used in combinatio 1018 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 1019 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 1020 lockup has been detected. This feature is useful for
1092 high-availability systems that have 1021 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 1022 where a lockup must be resolved ASAP.
1094 1023
1095 Say N if unsure. 1024 Say N if unsure.
1096 1025
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 1026 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
>> 1027 int
>> 1028 depends on SOFTLOCKUP_DETECTOR
>> 1029 range 0 1
>> 1030 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
>> 1031 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
>> 1032
>> 1033 config HARDLOCKUP_DETECTOR_PERF
1098 bool 1034 bool
1099 depends on SMP !! 1035 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 1036
1102 # 1037 #
1103 # Global switch whether to build a hardlockup !! 1038 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 1039 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 1040 #
1107 # s390: it reported many false positive !! 1041 config HARDLOCKUP_CHECK_TIMESTAMP
>> 1042 bool
>> 1043
1108 # 1044 #
1109 # sparc64: has a custom implementation !! 1045 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 1046 # lockup detector rather than the perf based detector.
1111 # 1047 #
1112 config HARDLOCKUP_DETECTOR 1048 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 1049 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 1050 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 1051 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 1052 select LOCKUP_DETECTOR
1120 !! 1053 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
>> 1054 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
1121 help 1055 help
1122 Say Y here to enable the kernel to 1056 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 1057 hard lockups.
1124 1058
1125 Hardlockups are bugs that cause the 1059 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 1060 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 1061 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 1062 and the system will stay locked up.
1129 1063
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 1064 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 1065 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 1066 depends on HARDLOCKUP_DETECTOR
1190 help 1067 help
1191 Say Y here to enable the kernel to 1068 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 1069 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 1070 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 1071 using the watchdog_thresh sysctl).
1195 1072
1196 Say N if unsure. 1073 Say N if unsure.
1197 1074
>> 1075 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
>> 1076 int
>> 1077 depends on HARDLOCKUP_DETECTOR
>> 1078 range 0 1
>> 1079 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
>> 1080 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
>> 1081
1198 config DETECT_HUNG_TASK 1082 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 1083 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 1084 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 1085 default SOFTLOCKUP_DETECTOR
1202 help 1086 help
1203 Say Y here to enable the kernel to 1087 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 1088 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 1089 uninterruptible "D" state indefinitely.
1206 1090
1207 When a hung task is detected, the k 1091 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 1092 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 1093 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 1094 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 1095 feature has negligible overhead.
1212 1096
1213 config DEFAULT_HUNG_TASK_TIMEOUT 1097 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 1098 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 1099 depends on DETECT_HUNG_TASK
1216 default 120 1100 default 120
1217 help 1101 help
1218 This option controls the default ti 1102 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 1103 to determine when a task has become non-responsive and should
1220 be considered hung. 1104 be considered hung.
1221 1105
1222 It can be adjusted at runtime via t 1106 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 1107 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 1108 /proc/sys/kernel/hung_task_timeout_secs.
1225 1109
1226 A timeout of 0 disables the check. 1110 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 1111 Keeping the default should be fine in most cases.
1228 1112
1229 config BOOTPARAM_HUNG_TASK_PANIC 1113 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 1114 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 1115 depends on DETECT_HUNG_TASK
1232 help 1116 help
1233 Say Y here to enable the kernel to 1117 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 1118 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 1119 in uninterruptible "D" state.
1236 1120
1237 The panic can be used in combinatio 1121 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 1122 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 1123 hung task has been detected. This feature is useful for
1240 high-availability systems that have 1124 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 1125 where a hung tasks must be resolved ASAP.
1242 1126
1243 Say N if unsure. 1127 Say N if unsure.
1244 1128
>> 1129 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
>> 1130 int
>> 1131 depends on DETECT_HUNG_TASK
>> 1132 range 0 1
>> 1133 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
>> 1134 default 1 if BOOTPARAM_HUNG_TASK_PANIC
>> 1135
1245 config WQ_WATCHDOG 1136 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 1137 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 1138 depends on DEBUG_KERNEL
1248 help 1139 help
1249 Say Y here to enable stall detectio 1140 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 1141 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 1142 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 1143 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 1144 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 1145 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 1146
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 1147 config TEST_LOCKUP
1270 tristate "Test module to generate loc 1148 tristate "Test module to generate lockups"
1271 depends on m 1149 depends on m
1272 help 1150 help
1273 This builds the "test_lockup" modul 1151 This builds the "test_lockup" module that helps to make sure
1274 that watchdogs and lockup detectors 1152 that watchdogs and lockup detectors are working properly.
1275 1153
1276 Depending on module parameters it c 1154 Depending on module parameters it could emulate soft or hard
1277 lockup, "hung task", or locking arb 1155 lockup, "hung task", or locking arbitrary lock for a long time.
1278 Also it could generate series of lo 1156 Also it could generate series of lockups with cooling-down periods.
1279 1157
1280 If unsure, say N. 1158 If unsure, say N.
1281 1159
1282 endmenu # "Debug lockups and hangs" 1160 endmenu # "Debug lockups and hangs"
1283 1161
1284 menu "Scheduler Debugging" 1162 menu "Scheduler Debugging"
1285 1163
1286 config SCHED_DEBUG 1164 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 1165 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS !! 1166 depends on DEBUG_KERNEL && PROC_FS
1289 default y 1167 default y
1290 help 1168 help
1291 If you say Y here, the /sys/kernel/ !! 1169 If you say Y here, the /proc/sched_debug file will be provided
1292 that can help debug the scheduler. 1170 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 1171 option is minimal.
1294 1172
1295 config SCHED_INFO 1173 config SCHED_INFO
1296 bool 1174 bool
1297 default n 1175 default n
1298 1176
1299 config SCHEDSTATS 1177 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1178 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1179 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1180 select SCHED_INFO
1303 help 1181 help
1304 If you say Y here, additional code 1182 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1183 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1184 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1185 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1186 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1187 application, you can say N to avoid the very slight overhead
1310 this adds. 1188 this adds.
1311 1189
1312 endmenu 1190 endmenu
1313 1191
1314 config DEBUG_TIMEKEEPING 1192 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1193 bool "Enable extra timekeeping sanity checking"
1316 help 1194 help
1317 This option will enable additional 1195 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1196 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1197 problems are suspected.
1320 1198
1321 This may include checks in the time 1199 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1200 option may have a (very small) performance impact to some
1323 workloads. 1201 workloads.
1324 1202
1325 If unsure, say N. 1203 If unsure, say N.
1326 1204
1327 config DEBUG_PREEMPT 1205 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1206 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION 1207 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
>> 1208 default y
1330 help 1209 help
1331 If you say Y here then the kernel w 1210 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1211 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1212 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1213 will detect preemption count underflows.
1335 1214
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 1215 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1216
1342 config LOCK_DEBUGGING_SUPPORT 1217 config LOCK_DEBUGGING_SUPPORT
1343 bool 1218 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1219 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1220 default y
1346 1221
1347 config PROVE_LOCKING 1222 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1223 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1224 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1225 select LOCKDEP
1351 select DEBUG_SPINLOCK 1226 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT !! 1227 select DEBUG_MUTEXES
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1228 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1229 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1230 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1231 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE 1232 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358 select TRACE_IRQFLAGS 1233 select TRACE_IRQFLAGS
1359 default n 1234 default n
1360 help 1235 help
1361 This feature enables the kernel to p 1236 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1237 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1238 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1239 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1240 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1241 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1242 deadlock.
1368 1243
1369 In short, this feature enables the k 1244 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1245 related deadlocks before they actually occur.
1371 1246
1372 The proof does not depend on how har 1247 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1248 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1249 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1250 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1251 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1252 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1253 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1254 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1255 makes the deadlock theoretically possible).
1381 1256
1382 If a deadlock is impossible (i.e. th 1257 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1258 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1259 kernel reports nothing.
1385 1260
1386 NOTE: this feature can also be enabl 1261 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1262 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1263 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1264 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1265 arbitrary combination of these separate locking variants.
1391 1266
1392 For more details, see Documentation/ 1267 For more details, see Documentation/locking/lockdep-design.rst.
1393 1268
1394 config PROVE_RAW_LOCK_NESTING 1269 config PROVE_RAW_LOCK_NESTING
1395 bool "Enable raw_spinlock - spinlock 1270 bool "Enable raw_spinlock - spinlock nesting checks"
1396 depends on PROVE_LOCKING 1271 depends on PROVE_LOCKING
1397 default n 1272 default n
1398 help 1273 help
1399 Enable the raw_spinlock vs. spinlock 1274 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400 that the lock nesting rules for PREE 1275 that the lock nesting rules for PREEMPT_RT enabled kernels are
1401 not violated. 1276 not violated.
1402 1277
1403 NOTE: There are known nesting proble 1278 NOTE: There are known nesting problems. So if you enable this
1404 option expect lockdep splats until t 1279 option expect lockdep splats until these problems have been fully
1405 addressed which is work in progress. 1280 addressed which is work in progress. This config switch allows to
1406 identify and analyze these problems. 1281 identify and analyze these problems. It will be removed and the
1407 check permanently enabled once the m !! 1282 check permanentely enabled once the main issues have been fixed.
1408 1283
1409 If unsure, select N. 1284 If unsure, select N.
1410 1285
1411 config LOCK_STAT 1286 config LOCK_STAT
1412 bool "Lock usage statistics" 1287 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1288 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1289 select LOCKDEP
1415 select DEBUG_SPINLOCK 1290 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT !! 1291 select DEBUG_MUTEXES
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1292 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1293 select DEBUG_LOCK_ALLOC
1419 default n 1294 default n
1420 help 1295 help
1421 This feature enables tracking lock c 1296 This feature enables tracking lock contention points
1422 1297
1423 For more details, see Documentation/ 1298 For more details, see Documentation/locking/lockstat.rst
1424 1299
1425 This also enables lock events requir 1300 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1301 subcommand of perf.
1427 If you want to use "perf lock", you 1302 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1303 CONFIG_EVENT_TRACING.
1429 1304
1430 CONFIG_LOCK_STAT defines "contended" 1305 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1306 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1307
1433 config DEBUG_RT_MUTEXES 1308 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1309 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1310 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1311 help
1437 This allows rt mutex semantics viola 1312 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1313 deadlocks (lockups) to be detected and reported automatically.
1439 1314
1440 config DEBUG_SPINLOCK 1315 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1316 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1317 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1318 select UNINLINE_SPIN_UNLOCK
1444 help 1319 help
1445 Say Y here and build SMP to catch m 1320 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1321 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1322 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1323 deadlocks are also debuggable.
1449 1324
1450 config DEBUG_MUTEXES 1325 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1326 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R !! 1327 depends on DEBUG_KERNEL
1453 help 1328 help
1454 This feature allows mutex semantics 1329 This feature allows mutex semantics violations to be detected and
1455 reported. 1330 reported.
1456 1331
1457 config DEBUG_WW_MUTEX_SLOWPATH 1332 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1333 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1334 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1335 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1336 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT !! 1337 select DEBUG_MUTEXES
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT <<
1464 help 1338 help
1465 This feature enables slowpath testin 1339 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1340 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1341 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1342 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1343 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1344 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1345 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1346 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1347 you are a distro, do not.
1474 1348
1475 config DEBUG_RWSEMS 1349 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1350 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1351 depends on DEBUG_KERNEL
1478 help 1352 help
1479 This debugging feature allows misma 1353 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1354 and unlocks to be detected and reported.
1481 1355
1482 config DEBUG_LOCK_ALLOC 1356 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1357 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1358 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1359 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT !! 1360 select DEBUG_MUTEXES
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1361 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1362 select LOCKDEP
1489 help 1363 help
1490 This feature will check whether any 1364 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1365 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1366 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1367 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1368 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1369 held during task exit.
1496 1370
1497 config LOCKDEP 1371 config LOCKDEP
1498 bool 1372 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1373 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1374 select STACKTRACE
1501 select KALLSYMS 1375 select KALLSYMS
1502 select KALLSYMS_ALL 1376 select KALLSYMS_ALL
1503 1377
1504 config LOCKDEP_SMALL 1378 config LOCKDEP_SMALL
1505 bool 1379 bool
1506 1380
1507 config LOCKDEP_BITS 1381 config LOCKDEP_BITS
1508 int "Bitsize for MAX_LOCKDEP_ENTRIES" 1382 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1509 depends on LOCKDEP && !LOCKDEP_SMALL 1383 depends on LOCKDEP && !LOCKDEP_SMALL
1510 range 10 30 1384 range 10 30
1511 default 15 1385 default 15
1512 help 1386 help
1513 Try increasing this value if you hi 1387 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1514 1388
1515 config LOCKDEP_CHAINS_BITS 1389 config LOCKDEP_CHAINS_BITS
1516 int "Bitsize for MAX_LOCKDEP_CHAINS" 1390 int "Bitsize for MAX_LOCKDEP_CHAINS"
1517 depends on LOCKDEP && !LOCKDEP_SMALL 1391 depends on LOCKDEP && !LOCKDEP_SMALL
1518 range 10 30 1392 range 10 30
1519 default 16 1393 default 16
1520 help 1394 help
1521 Try increasing this value if you hi 1395 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1522 1396
1523 config LOCKDEP_STACK_TRACE_BITS 1397 config LOCKDEP_STACK_TRACE_BITS
1524 int "Bitsize for MAX_STACK_TRACE_ENTR 1398 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1525 depends on LOCKDEP && !LOCKDEP_SMALL 1399 depends on LOCKDEP && !LOCKDEP_SMALL
1526 range 10 30 1400 range 10 30
1527 default 19 1401 default 19
1528 help 1402 help
1529 Try increasing this value if you hi 1403 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1530 1404
1531 config LOCKDEP_STACK_TRACE_HASH_BITS 1405 config LOCKDEP_STACK_TRACE_HASH_BITS
1532 int "Bitsize for STACK_TRACE_HASH_SIZ 1406 int "Bitsize for STACK_TRACE_HASH_SIZE"
1533 depends on LOCKDEP && !LOCKDEP_SMALL 1407 depends on LOCKDEP && !LOCKDEP_SMALL
1534 range 10 30 1408 range 10 30
1535 default 14 1409 default 14
1536 help 1410 help
1537 Try increasing this value if you ne !! 1411 Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES.
1538 1412
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS 1413 config LOCKDEP_CIRCULAR_QUEUE_BITS
1540 int "Bitsize for elements in circular 1414 int "Bitsize for elements in circular_queue struct"
1541 depends on LOCKDEP 1415 depends on LOCKDEP
1542 range 10 30 1416 range 10 30
1543 default 12 1417 default 12
1544 help 1418 help
1545 Try increasing this value if you hi 1419 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1546 1420
1547 config DEBUG_LOCKDEP 1421 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1422 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1423 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS 1424 select DEBUG_IRQFLAGS
1551 help 1425 help
1552 If you say Y here, the lock depende 1426 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1427 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1428 of more runtime overhead.
1555 1429
1556 config DEBUG_ATOMIC_SLEEP 1430 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1431 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1432 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1433 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1434 depends on !ARCH_NO_PREEMPT
1561 help 1435 help
1562 If you say Y here, various routines 1436 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1437 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1438 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1439 sections, inside an interrupt, etc...
1566 1440
1567 config DEBUG_LOCKING_API_SELFTESTS 1441 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1442 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1443 depends on DEBUG_KERNEL
1570 help 1444 help
1571 Say Y here if you want the kernel t 1445 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1446 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1447 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' !! 1448 lock debugging then those bugs wont be detected of course.)
1575 The following locking APIs are cove 1449 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1450 mutexes and rwsems.
1577 1451
1578 config LOCK_TORTURE_TEST 1452 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1453 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1454 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1455 select TORTURE_TEST
1582 help 1456 help
1583 This option provides a kernel modul 1457 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1458 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1459 after the fact on the running kernel to be tested, if desired.
1586 1460
1587 Say Y here if you want kernel locki 1461 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1462 to be built into the kernel.
1589 Say M if you want these torture tes 1463 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1464 Say N if you are unsure.
1591 1465
1592 config WW_MUTEX_SELFTEST 1466 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1467 tristate "Wait/wound mutex selftests"
1594 help 1468 help
1595 This option provides a kernel modul 1469 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1470 on the struct ww_mutex locking API.
1597 1471
1598 It is recommended to enable DEBUG_W 1472 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1473 with this test harness.
1600 1474
1601 Say M if you want these self tests 1475 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1476 Say N if you are unsure.
1603 1477
1604 config SCF_TORTURE_TEST 1478 config SCF_TORTURE_TEST
1605 tristate "torture tests for smp_call_ 1479 tristate "torture tests for smp_call_function*()"
1606 depends on DEBUG_KERNEL 1480 depends on DEBUG_KERNEL
1607 select TORTURE_TEST 1481 select TORTURE_TEST
1608 help 1482 help
1609 This option provides a kernel modul 1483 This option provides a kernel module that runs torture tests
1610 on the smp_call_function() family o 1484 on the smp_call_function() family of primitives. The kernel
1611 module may be built after the fact 1485 module may be built after the fact on the running kernel to
1612 be tested, if desired. 1486 be tested, if desired.
1613 1487
1614 config CSD_LOCK_WAIT_DEBUG 1488 config CSD_LOCK_WAIT_DEBUG
1615 bool "Debugging for csd_lock_wait(), 1489 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616 depends on DEBUG_KERNEL 1490 depends on DEBUG_KERNEL
1617 depends on 64BIT 1491 depends on 64BIT
1618 default n 1492 default n
1619 help 1493 help
1620 This option enables debug prints wh 1494 This option enables debug prints when CPUs are slow to respond
1621 to the smp_call_function*() IPI wra 1495 to the smp_call_function*() IPI wrappers. These debug prints
1622 include the IPI handler function cu 1496 include the IPI handler function currently executing (if any)
1623 and relevant stack traces. 1497 and relevant stack traces.
1624 1498
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 1499 endmenu # lock debugging
1635 1500
1636 config TRACE_IRQFLAGS 1501 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT 1502 depends on TRACE_IRQFLAGS_SUPPORT
1638 bool 1503 bool
1639 help 1504 help
1640 Enables hooks to interrupt enabling 1505 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1506 either tracing or lock debugging.
1642 1507
1643 config TRACE_IRQFLAGS_NMI 1508 config TRACE_IRQFLAGS_NMI
1644 def_bool y 1509 def_bool y
1645 depends on TRACE_IRQFLAGS 1510 depends on TRACE_IRQFLAGS
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT 1511 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647 1512
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 1513 config DEBUG_IRQFLAGS
1660 bool "Debug IRQ flag manipulation" 1514 bool "Debug IRQ flag manipulation"
1661 help 1515 help
1662 Enables checks for potentially unsa 1516 Enables checks for potentially unsafe enabling or disabling of
1663 interrupts, such as calling raw_loc 1517 interrupts, such as calling raw_local_irq_restore() when interrupts
1664 are enabled. 1518 are enabled.
1665 1519
1666 config STACKTRACE 1520 config STACKTRACE
1667 bool "Stack backtrace support" 1521 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1522 depends on STACKTRACE_SUPPORT
1669 help 1523 help
1670 This option causes the kernel to cr 1524 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1525 every process, showing its current stack trace.
1672 It is also used by various kernel d 1526 It is also used by various kernel debugging features that require
1673 stack trace generation. 1527 stack trace generation.
1674 1528
1675 config WARN_ALL_UNSEEDED_RANDOM 1529 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1530 bool "Warn for all uses of unseeded randomness"
1677 default n 1531 default n
1678 help 1532 help
1679 Some parts of the kernel contain bu 1533 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1534 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1535 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1536 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1537 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1538 are going wrong, so that they might contact developers about fixing
1685 it. 1539 it.
1686 1540
1687 Unfortunately, on some models of so 1541 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1542 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1543 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1544 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1545 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1546 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1547 However, since users cannot do anything actionable to
1694 address this, by default this optio !! 1548 address this, by default the kernel will issue only a single
>> 1549 warning for the first use of unseeded randomness.
1695 1550
1696 Say Y here if you want to receive w 1551 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1552 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1553 those developers interested in improving the security of
1699 Linux kernels running on their arch 1554 Linux kernels running on their architecture (or
1700 subarchitecture). 1555 subarchitecture).
1701 1556
1702 config DEBUG_KOBJECT 1557 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1558 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1559 depends on DEBUG_KERNEL
1705 help 1560 help
1706 If you say Y here, some extra kobje 1561 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1562 to the syslog.
1708 1563
1709 config DEBUG_KOBJECT_RELEASE 1564 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1565 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1566 depends on DEBUG_OBJECTS_TIMERS
1712 help 1567 help
1713 kobjects are reference counted obje 1568 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1569 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d !! 1570 live on past the point at which a driver decides to drop it's
1716 initial reference to the kobject ga 1571 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1572 example of this would be a struct device which has just been
1718 unregistered. 1573 unregistered.
1719 1574
1720 However, some buggy drivers assume 1575 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1576 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1577 goes completely against the principles of a refcounted object.
1723 1578
1724 If you say Y here, the kernel will 1579 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1580 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1581 kind of kobject release bug.
1727 1582
1728 config HAVE_DEBUG_BUGVERBOSE 1583 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1584 bool
1730 1585
1731 menu "Debug kernel data structures" 1586 menu "Debug kernel data structures"
1732 1587
1733 config DEBUG_LIST 1588 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1589 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1590 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1591 help
1738 Enable this to turn on extended che !! 1592 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1593 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 1594
1745 If unsure, say N. 1595 If unsure, say N.
1746 1596
1747 config DEBUG_PLIST 1597 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1598 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1599 depends on DEBUG_KERNEL
1750 help 1600 help
1751 Enable this to turn on extended che 1601 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1602 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1603 list multiple times during each manipulation.
1754 1604
1755 If unsure, say N. 1605 If unsure, say N.
1756 1606
1757 config DEBUG_SG 1607 config DEBUG_SG
1758 bool "Debug SG table operations" 1608 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1609 depends on DEBUG_KERNEL
1760 help 1610 help
1761 Enable this to turn on checks on sc 1611 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1612 help find problems with drivers that do not properly initialize
1763 their sg tables. 1613 their sg tables.
1764 1614
1765 If unsure, say N. 1615 If unsure, say N.
1766 1616
1767 config DEBUG_NOTIFIERS 1617 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1618 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1619 depends on DEBUG_KERNEL
1770 help 1620 help
1771 Enable this to turn on sanity check 1621 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1622 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1623 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1624 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1625 performance, say N.
1776 1626
1777 config DEBUG_CLOSURES !! 1627 config BUG_ON_DATA_CORRUPTION
1778 bool "Debug closures (bcache async wi !! 1628 bool "Trigger a BUG when data corruption is detected"
1779 depends on CLOSURES !! 1629 select DEBUG_LIST
1780 select DEBUG_FS !! 1630 help
1781 help !! 1631 Select this option if the kernel should BUG when it encounters
1782 Keeps all active closures in a link !! 1632 data corruption in kernel memory structures when they get checked
1783 interface to list them, which makes !! 1633 for validity.
1784 operations that get stuck. <<
1785 1634
1786 config DEBUG_MAPLE_TREE !! 1635 If unsure, say N.
1787 bool "Debug maple trees" !! 1636
>> 1637 endmenu
>> 1638
>> 1639 config DEBUG_CREDENTIALS
>> 1640 bool "Debug credential management"
1788 depends on DEBUG_KERNEL 1641 depends on DEBUG_KERNEL
1789 help 1642 help
1790 Enable maple tree debugging informa !! 1643 Enable this to turn on some debug checking for credential
>> 1644 management. The additional code keeps track of the number of
>> 1645 pointers from task_structs to any given cred struct, and checks to
>> 1646 see that this number never exceeds the usage count of the cred
>> 1647 struct.
1791 1648
1792 If unsure, say N. !! 1649 Furthermore, if SELinux is enabled, this also checks that the
>> 1650 security pointer in the cred struct is never seen to be invalid.
1793 1651
1794 endmenu !! 1652 If unsure, say N.
1795 1653
1796 source "kernel/rcu/Kconfig.debug" 1654 source "kernel/rcu/Kconfig.debug"
1797 1655
1798 config DEBUG_WQ_FORCE_RR_CPU 1656 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1657 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1658 depends on DEBUG_KERNEL
1801 default n 1659 default n
1802 help 1660 help
1803 Workqueue used to implicitly guaran 1661 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1662 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1663 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1664 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1665 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1666 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1667 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1668 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1669 be impacted.
1812 1670
>> 1671 config DEBUG_BLOCK_EXT_DEVT
>> 1672 bool "Force extended block device numbers and spread them"
>> 1673 depends on DEBUG_KERNEL
>> 1674 depends on BLOCK
>> 1675 default n
>> 1676 help
>> 1677 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
>> 1678 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
>> 1679 YOU ARE DOING. Distros, please enable this and fix whatever
>> 1680 is broken.
>> 1681
>> 1682 Conventionally, block device numbers are allocated from
>> 1683 predetermined contiguous area. However, extended block area
>> 1684 may introduce non-contiguous block device numbers. This
>> 1685 option forces most block device numbers to be allocated from
>> 1686 the extended space and spreads them to discover kernel or
>> 1687 userland code paths which assume predetermined contiguous
>> 1688 device number allocation.
>> 1689
>> 1690 Note that turning on this debug option shuffles all the
>> 1691 device numbers for all IDE and SCSI devices including libata
>> 1692 ones, so root partition specified using device number
>> 1693 directly (via rdev or root=MAJ:MIN) won't work anymore.
>> 1694 Textual device names (root=/dev/sdXn) will continue to work.
>> 1695
>> 1696 Say N if you are unsure.
>> 1697
1813 config CPU_HOTPLUG_STATE_CONTROL 1698 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1699 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1700 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1701 depends on HOTPLUG_CPU
1817 default n 1702 default n
1818 help 1703 help
1819 Allows to write steps between "offl 1704 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1705 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1706 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1707 restarted at arbitrary points yet.
1823 1708
1824 Say N if your are unsure. 1709 Say N if your are unsure.
1825 1710
1826 config LATENCYTOP 1711 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1712 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1713 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1714 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1715 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P 1716 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832 select KALLSYMS 1717 select KALLSYMS
1833 select KALLSYMS_ALL 1718 select KALLSYMS_ALL
1834 select STACKTRACE 1719 select STACKTRACE
1835 select SCHEDSTATS 1720 select SCHEDSTATS
1836 help 1721 help
1837 Enable this option if you want to u 1722 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1723 to find out which userspace is blocking on what kernel operations.
1839 1724
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" 1725 source "kernel/trace/Kconfig"
1851 1726
1852 config PROVIDE_OHCI1394_DMA_INIT 1727 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1728 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1729 depends on PCI && X86
1855 help 1730 help
1856 If you want to debug problems which 1731 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1732 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1733 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1734 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1735 specification which is now the standard for FireWire controllers.
1861 1736
1862 With remote DMA, you can monitor th 1737 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1738 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1739 Even controlling a kernel debugger is possible using remote DMA.
1865 1740
1866 Usage: 1741 Usage:
1867 1742
1868 If ohci1394_dma=early is used as bo 1743 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1744 all OHCI1394 controllers which are found in the PCI config space.
1870 1745
1871 As all changes to the FireWire bus 1746 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1747 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1748 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1749 the debugging host before booting the debug target for debugging.
1875 1750
1876 This code (~1k) is freed after boot 1751 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1752 in charge of the OHCI-1394 controllers should be used instead.
1878 1753
1879 See Documentation/core-api/debuggin 1754 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880 1755
1881 source "samples/Kconfig" 1756 source "samples/Kconfig"
1882 1757
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1758 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1759 bool
1885 1760
1886 config STRICT_DEVMEM 1761 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1762 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1763 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED 1764 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1765 default y if PPC || X86 || ARM64
1891 help 1766 help
1892 If this option is disabled, you all 1767 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1768 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1769 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1770 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1771 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1772 use due to the cache aliasing requirements.
1898 1773
1899 If this option is switched on, and 1774 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1775 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1776 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1777 users of /dev/mem.
1903 1778
1904 If in doubt, say Y. 1779 If in doubt, say Y.
1905 1780
1906 config IO_STRICT_DEVMEM 1781 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1782 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1783 depends on STRICT_DEVMEM
1909 help 1784 help
1910 If this option is disabled, you all 1785 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1786 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1787 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1788 specific access can be used by people debugging kernel drivers.
1914 1789
1915 If this option is switched on, the 1790 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1791 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1792 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1793 if the driver using a given range cannot be disabled.
1919 1794
1920 If in doubt, say Y. 1795 If in doubt, say Y.
1921 1796
1922 menu "$(SRCARCH) Debugging" 1797 menu "$(SRCARCH) Debugging"
1923 1798
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1799 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1800
1926 endmenu 1801 endmenu
1927 1802
1928 menu "Kernel Testing and Coverage" 1803 menu "Kernel Testing and Coverage"
1929 1804
1930 source "lib/kunit/Kconfig" 1805 source "lib/kunit/Kconfig"
1931 1806
1932 config NOTIFIER_ERROR_INJECTION 1807 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1808 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1809 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1810 select DEBUG_FS
1936 help 1811 help
1937 This option provides the ability to 1812 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1813 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1814 handling of notifier call chain failures.
1940 1815
1941 Say N if unsure. 1816 Say N if unsure.
1942 1817
1943 config PM_NOTIFIER_ERROR_INJECT 1818 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1819 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1820 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1821 default m if PM_DEBUG
1947 help 1822 help
1948 This option provides the ability to 1823 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1824 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1825 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1826
1952 If the notifier call chain should b 1827 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1828 notified, write the error code to "actions/<notifier event>/error".
1954 1829
1955 Example: Inject PM suspend error (- 1830 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1831
1957 # cd /sys/kernel/debug/notifier-err 1832 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1833 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1834 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1835 bash: echo: write error: Cannot allocate memory
1961 1836
1962 To compile this code as a module, c 1837 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1838 be called pm-notifier-error-inject.
1964 1839
1965 If unsure, say N. 1840 If unsure, say N.
1966 1841
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1842 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1843 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1844 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1845 help
1971 This option provides the ability to 1846 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1847 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1848 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1849 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1850
1976 If the notifier call chain should b 1851 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1852 notified, write the error code to "actions/<notifier event>/error".
1978 1853
1979 To compile this code as a module, c 1854 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1855 be called of-reconfig-notifier-error-inject.
1981 1856
1982 If unsure, say N. 1857 If unsure, say N.
1983 1858
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1859 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1860 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1861 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1862 help
1988 This option provides the ability to 1863 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1864 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1865 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1866
1992 If the notifier call chain should b 1867 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1868 notified, write the error code to "actions/<notifier event>/error".
1994 1869
1995 Example: Inject netdevice mtu chang 1870 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1871
1997 # cd /sys/kernel/debug/notifier-err 1872 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1873 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1874 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1875 RTNETLINK answers: Invalid argument
2001 1876
2002 To compile this code as a module, c 1877 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1878 be called netdev-notifier-error-inject.
2004 1879
2005 If unsure, say N. 1880 If unsure, say N.
2006 1881
2007 config FUNCTION_ERROR_INJECTION 1882 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" !! 1883 def_bool y
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1884 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 1885
2017 config FAULT_INJECTION 1886 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1887 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1888 depends on DEBUG_KERNEL
2020 help 1889 help
2021 Provide fault-injection framework. 1890 Provide fault-injection framework.
2022 For more details, see Documentation 1891 For more details, see Documentation/fault-injection/.
2023 1892
2024 config FAILSLAB 1893 config FAILSLAB
2025 bool "Fault-injection capability for 1894 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1895 depends on FAULT_INJECTION
>> 1896 depends on SLAB || SLUB
2027 help 1897 help
2028 Provide fault-injection capability 1898 Provide fault-injection capability for kmalloc.
2029 1899
2030 config FAIL_PAGE_ALLOC 1900 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for 1901 bool "Fault-injection capability for alloc_pages()"
2032 depends on FAULT_INJECTION 1902 depends on FAULT_INJECTION
2033 help 1903 help
2034 Provide fault-injection capability 1904 Provide fault-injection capability for alloc_pages().
2035 1905
2036 config FAULT_INJECTION_USERCOPY 1906 config FAULT_INJECTION_USERCOPY
2037 bool "Fault injection capability for 1907 bool "Fault injection capability for usercopy functions"
2038 depends on FAULT_INJECTION 1908 depends on FAULT_INJECTION
2039 help 1909 help
2040 Provides fault-injection capability 1910 Provides fault-injection capability to inject failures
2041 in usercopy functions (copy_from_us 1911 in usercopy functions (copy_from_user(), get_user(), ...).
2042 1912
2043 config FAIL_MAKE_REQUEST 1913 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1914 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1915 depends on FAULT_INJECTION && BLOCK
2046 help 1916 help
2047 Provide fault-injection capability 1917 Provide fault-injection capability for disk IO.
2048 1918
2049 config FAIL_IO_TIMEOUT 1919 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1920 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1921 depends on FAULT_INJECTION && BLOCK
2052 help 1922 help
2053 Provide fault-injection capability 1923 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1924 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1925 thus exercising the error handling.
2056 1926
2057 Only works with drivers that use th 1927 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. !! 1928 for others it wont do anything.
2059 1929
2060 config FAIL_FUTEX 1930 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1931 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1932 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1933 depends on FAULT_INJECTION && FUTEX
2064 help 1934 help
2065 Provide fault-injection capability 1935 Provide fault-injection capability for futexes.
2066 1936
2067 config FAULT_INJECTION_DEBUG_FS 1937 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1938 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1939 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1940 help
2071 Enable configuration of fault-injec 1941 Enable configuration of fault-injection capabilities via debugfs.
2072 1942
2073 config FAIL_FUNCTION 1943 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1944 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1945 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1946 help
2077 Provide function-based fault-inject 1947 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1948 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1949 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1950 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1951 error handling in various subsystems.
2082 1952
2083 config FAIL_MMC_REQUEST 1953 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1954 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1955 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1956 help
2087 Provide fault-injection capability 1957 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1958 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1959 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1960 and to test how the mmc host driver handles retries from
2091 the block device. 1961 the block device.
2092 1962
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 1963 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1964 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1965 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS !! 1966 depends on !X86_64
2115 select STACKTRACE 1967 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P 1968 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117 help 1969 help
2118 Provide stacktrace filter for fault 1970 Provide stacktrace filter for fault-injection capabilities
2119 1971
2120 config ARCH_HAS_KCOV 1972 config ARCH_HAS_KCOV
2121 bool 1973 bool
2122 help 1974 help
2123 An architecture should select this 1975 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 1976 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 1977 disabling instrumentation for some early boot code.
2126 1978
2127 config CC_HAS_SANCOV_TRACE_PC 1979 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 1980 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 1981
2130 1982
2131 config KCOV 1983 config KCOV
2132 bool "Code coverage for fuzzing" 1984 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 1985 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 1986 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 1987 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 1988 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK <<
2140 help 1989 help
2141 KCOV exposes kernel code coverage i 1990 KCOV exposes kernel code coverage information in a form suitable
2142 for coverage-guided fuzzing (random 1991 for coverage-guided fuzzing (randomized testing).
2143 1992
>> 1993 If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> 1994 different machines and across reboots. If you need stable PC values,
>> 1995 disable RANDOMIZE_BASE.
>> 1996
2144 For more details, see Documentation 1997 For more details, see Documentation/dev-tools/kcov.rst.
2145 1998
2146 config KCOV_ENABLE_COMPARISONS 1999 config KCOV_ENABLE_COMPARISONS
2147 bool "Enable comparison operands coll 2000 bool "Enable comparison operands collection by KCOV"
2148 depends on KCOV 2001 depends on KCOV
2149 depends on $(cc-option,-fsanitize-cov 2002 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2150 help 2003 help
2151 KCOV also exposes operands of every 2004 KCOV also exposes operands of every comparison in the instrumented
2152 code along with operand sizes and P 2005 code along with operand sizes and PCs of the comparison instructions.
2153 These operands can be used by fuzzi 2006 These operands can be used by fuzzing engines to improve the quality
2154 of fuzzing coverage. 2007 of fuzzing coverage.
2155 2008
2156 config KCOV_INSTRUMENT_ALL 2009 config KCOV_INSTRUMENT_ALL
2157 bool "Instrument all code by default" 2010 bool "Instrument all code by default"
2158 depends on KCOV 2011 depends on KCOV
2159 default y 2012 default y
2160 help 2013 help
2161 If you are doing generic system cal 2014 If you are doing generic system call fuzzing (like e.g. syzkaller),
2162 then you will want to instrument th 2015 then you will want to instrument the whole kernel and you should
2163 say y here. If you are doing more t 2016 say y here. If you are doing more targeted fuzzing (like e.g.
2164 filesystem fuzzing with AFL) then y 2017 filesystem fuzzing with AFL) then you will want to enable coverage
2165 for more specific subsets of files, 2018 for more specific subsets of files, and should say n here.
2166 2019
2167 config KCOV_IRQ_AREA_SIZE 2020 config KCOV_IRQ_AREA_SIZE
2168 hex "Size of interrupt coverage colle 2021 hex "Size of interrupt coverage collection area in words"
2169 depends on KCOV 2022 depends on KCOV
2170 default 0x40000 2023 default 0x40000
2171 help 2024 help
2172 KCOV uses preallocated per-cpu area 2025 KCOV uses preallocated per-cpu areas to collect coverage from
2173 soft interrupts. This specifies the 2026 soft interrupts. This specifies the size of those areas in the
2174 number of unsigned long words. 2027 number of unsigned long words.
2175 2028
2176 menuconfig RUNTIME_TESTING_MENU 2029 menuconfig RUNTIME_TESTING_MENU
2177 bool "Runtime Testing" 2030 bool "Runtime Testing"
2178 default y !! 2031 def_bool y
2179 2032
2180 if RUNTIME_TESTING_MENU 2033 if RUNTIME_TESTING_MENU
2181 2034
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 2035 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 2036 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 2037 depends on DEBUG_FS
2220 help 2038 help
2221 This module enables testing of the di 2039 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 2040 inducing system failures at predefined crash points.
2223 If you don't need it: say N 2041 If you don't need it: say N
2224 Choose M here to compile this code as 2042 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 2043 called lkdtm.
2226 2044
2227 Documentation on how to use the modul 2045 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 2046 Documentation/fault-injection/provoke-crashes.rst
2229 2047
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 2048 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i !! 2049 tristate "Linked list sorting test"
2244 depends on KUNIT !! 2050 depends on DEBUG_KERNEL || m
2245 default KUNIT_ALL_TESTS <<
2246 help 2051 help
2247 Enable this to turn on 'list_sort() 2052 Enable this to turn on 'list_sort()' function test. This test is
2248 executed only once during system bo 2053 executed only once during system boot (so affects only boot time),
2249 or at module load time. 2054 or at module load time.
2250 2055
2251 If unsure, say N. 2056 If unsure, say N.
2252 2057
2253 config TEST_MIN_HEAP 2058 config TEST_MIN_HEAP
2254 tristate "Min heap test" 2059 tristate "Min heap test"
2255 depends on DEBUG_KERNEL || m 2060 depends on DEBUG_KERNEL || m
2256 help 2061 help
2257 Enable this to turn on min heap fun 2062 Enable this to turn on min heap function tests. This test is
2258 executed only once during system bo 2063 executed only once during system boot (so affects only boot time),
2259 or at module load time. 2064 or at module load time.
2260 2065
2261 If unsure, say N. 2066 If unsure, say N.
2262 2067
2263 config TEST_SORT 2068 config TEST_SORT
2264 tristate "Array-based sort test" if ! !! 2069 tristate "Array-based sort test"
2265 depends on KUNIT !! 2070 depends on DEBUG_KERNEL || m
2266 default KUNIT_ALL_TESTS <<
2267 help 2071 help
2268 This option enables the self-test f 2072 This option enables the self-test function of 'sort()' at boot,
2269 or at module load time. 2073 or at module load time.
2270 2074
2271 If unsure, say N. 2075 If unsure, say N.
2272 2076
2273 config TEST_DIV64 2077 config TEST_DIV64
2274 tristate "64bit/32bit division and mo 2078 tristate "64bit/32bit division and modulo test"
2275 depends on DEBUG_KERNEL || m 2079 depends on DEBUG_KERNEL || m
2276 help 2080 help
2277 Enable this to turn on 'do_div()' f 2081 Enable this to turn on 'do_div()' function test. This test is
2278 executed only once during system bo 2082 executed only once during system boot (so affects only boot time),
2279 or at module load time. 2083 or at module load time.
2280 2084
2281 If unsure, say N. 2085 If unsure, say N.
2282 2086
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 2087 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K !! 2088 bool "Kprobes sanity tests"
2297 depends on DEBUG_KERNEL 2089 depends on DEBUG_KERNEL
2298 depends on KPROBES 2090 depends on KPROBES
2299 depends on KUNIT <<
2300 select STACKTRACE if ARCH_CORRECT_STA <<
2301 default KUNIT_ALL_TESTS <<
2302 help 2091 help
2303 This option provides for testing ba 2092 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 2093 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 2094 verified for functionality.
2306 2095
2307 Say N if you are unsure. 2096 Say N if you are unsure.
2308 2097
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 2098 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 2099 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 2100 depends on DEBUG_KERNEL
2324 help 2101 help
2325 This option provides a kernel modul 2102 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 2103 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 2104 for distributions or general kernels, but only for kernel
2328 developers working on architecture 2105 developers working on architecture code.
2329 2106
2330 Note that if you want to also test 2107 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 2108 have to enable STACKTRACE as well.
2332 2109
2333 Say N if you are unsure. 2110 Say N if you are unsure.
2334 2111
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 2112 config RBTREE_TEST
2346 tristate "Red-Black tree test" 2113 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 2114 depends on DEBUG_KERNEL
2348 help 2115 help
2349 A benchmark measuring the performan 2116 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 2117 Also includes rbtree invariant checks.
2351 2118
2352 config REED_SOLOMON_TEST 2119 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 2120 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 2121 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 2122 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 2123 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 2124 select REED_SOLOMON_DEC16
2358 help 2125 help
2359 This option enables the self-test f 2126 This option enables the self-test function of rslib at boot,
2360 or at module load time. 2127 or at module load time.
2361 2128
2362 If unsure, say N. 2129 If unsure, say N.
2363 2130
2364 config INTERVAL_TREE_TEST 2131 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 2132 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 2133 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 2134 select INTERVAL_TREE
2368 help 2135 help
2369 A benchmark measuring the performan 2136 A benchmark measuring the performance of the interval tree library
2370 2137
2371 config PERCPU_TEST 2138 config PERCPU_TEST
2372 tristate "Per cpu operations test" 2139 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 2140 depends on m && DEBUG_KERNEL
2374 help 2141 help
2375 Enable this option to build test mo 2142 Enable this option to build test module which validates per-cpu
2376 operations. 2143 operations.
2377 2144
2378 If unsure, say N. 2145 If unsure, say N.
2379 2146
2380 config ATOMIC64_SELFTEST 2147 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 2148 tristate "Perform an atomic64_t self-test"
2382 help 2149 help
2383 Enable this option to test the atom 2150 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 2151 at module load time.
2385 2152
2386 If unsure, say N. 2153 If unsure, say N.
2387 2154
2388 config ASYNC_RAID6_TEST 2155 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 2156 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 2157 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 2158 select ASYNC_MEMCPY
2392 help 2159 help
2393 This is a one-shot self test that p 2160 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 2161 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 2162 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 2163 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 2164 engine if one is available.
2398 2165
2399 If unsure, say N. 2166 If unsure, say N.
2400 2167
2401 config TEST_HEXDUMP 2168 config TEST_HEXDUMP
2402 tristate "Test functions located in t 2169 tristate "Test functions located in the hexdump module at runtime"
2403 2170
2404 config STRING_KUNIT_TEST !! 2171 config TEST_STRING_HELPERS
2405 tristate "KUnit test string functions !! 2172 tristate "Test functions located in the string_helpers module at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 2173
2409 config STRING_HELPERS_KUNIT_TEST !! 2174 config TEST_STRSCPY
2410 tristate "KUnit test string helpers a !! 2175 tristate "Test strscpy*() family of functions at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 2176
2414 config TEST_KSTRTOX 2177 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 2178 tristate "Test kstrto*() family of functions at runtime"
2416 2179
2417 config TEST_PRINTF 2180 config TEST_PRINTF
2418 tristate "Test printf() family of fun 2181 tristate "Test printf() family of functions at runtime"
2419 2182
2420 config TEST_SCANF <<
2421 tristate "Test scanf() family of func <<
2422 <<
2423 config TEST_BITMAP 2183 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 2184 tristate "Test bitmap_*() family of functions at runtime"
2425 help 2185 help
2426 Enable this option to test the bitm 2186 Enable this option to test the bitmap functions at boot.
2427 2187
2428 If unsure, say N. 2188 If unsure, say N.
2429 2189
2430 config TEST_UUID 2190 config TEST_UUID
2431 tristate "Test functions located in t 2191 tristate "Test functions located in the uuid module at runtime"
2432 2192
2433 config TEST_XARRAY 2193 config TEST_XARRAY
2434 tristate "Test the XArray code at run 2194 tristate "Test the XArray code at runtime"
2435 2195
2436 config TEST_MAPLE_TREE !! 2196 config TEST_OVERFLOW
2437 tristate "Test the Maple Tree code at !! 2197 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 2198
2445 config TEST_RHASHTABLE 2199 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 2200 tristate "Perform selftest on resizable hash table"
2447 help 2201 help
2448 Enable this option to test the rhas 2202 Enable this option to test the rhashtable functions at boot.
2449 2203
2450 If unsure, say N. 2204 If unsure, say N.
2451 2205
>> 2206 config TEST_HASH
>> 2207 tristate "Perform selftest on hash functions"
>> 2208 help
>> 2209 Enable this option to test the kernel's integer (<linux/hash.h>),
>> 2210 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
>> 2211 hash functions on boot (or module load).
>> 2212
>> 2213 This is intended to help people writing architecture-specific
>> 2214 optimized versions. If unsure, say N.
>> 2215
2452 config TEST_IDA 2216 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 2217 tristate "Perform selftest on IDA functions"
2454 2218
2455 config TEST_PARMAN 2219 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 2220 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 2221 depends on PARMAN
2458 help 2222 help
2459 Enable this option to test priority 2223 Enable this option to test priority array manager on boot
2460 (or module load). 2224 (or module load).
2461 2225
2462 If unsure, say N. 2226 If unsure, say N.
2463 2227
2464 config TEST_IRQ_TIMINGS 2228 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 2229 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 2230 depends on IRQ_TIMINGS
2467 help 2231 help
2468 Enable this option to test the irq 2232 Enable this option to test the irq timings code on boot.
2469 2233
2470 If unsure, say N. 2234 If unsure, say N.
2471 2235
2472 config TEST_LKM 2236 config TEST_LKM
2473 tristate "Test module loading with 'h 2237 tristate "Test module loading with 'hello world' module"
2474 depends on m 2238 depends on m
2475 help 2239 help
2476 This builds the "test_module" modul 2240 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 2241 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 2242 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 2243 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 2244 and will not normally be loaded by the system unless explicitly
2481 requested by name. 2245 requested by name.
2482 2246
2483 If unsure, say N. 2247 If unsure, say N.
2484 2248
2485 config TEST_BITOPS 2249 config TEST_BITOPS
2486 tristate "Test module for compilation 2250 tristate "Test module for compilation of bitops operations"
>> 2251 depends on m
2487 help 2252 help
2488 This builds the "test_bitops" modul 2253 This builds the "test_bitops" module that is much like the
2489 TEST_LKM module except that it does 2254 TEST_LKM module except that it does a basic exercise of the
2490 set/clear_bit macros and get_count_ 2255 set/clear_bit macros and get_count_order/long to make sure there are
2491 no compiler warnings from C=1 spars 2256 no compiler warnings from C=1 sparse checker or -Wextra
2492 compilations. It has no dependencie 2257 compilations. It has no dependencies and doesn't run or load unless
2493 explicitly requested by name. for 2258 explicitly requested by name. for example: modprobe test_bitops.
2494 2259
2495 If unsure, say N. 2260 If unsure, say N.
2496 2261
2497 config TEST_VMALLOC 2262 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 2263 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 2264 default n
2500 depends on MMU 2265 depends on MMU
2501 depends on m 2266 depends on m
2502 help 2267 help
2503 This builds the "test_vmalloc" modu 2268 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 2269 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 2270 subsystem can be evaluated from performance and stability point
2506 of view. 2271 of view.
2507 2272
2508 If unsure, say N. 2273 If unsure, say N.
2509 2274
>> 2275 config TEST_USER_COPY
>> 2276 tristate "Test user/kernel boundary protections"
>> 2277 depends on m
>> 2278 help
>> 2279 This builds the "test_user_copy" module that runs sanity checks
>> 2280 on the copy_to/from_user infrastructure, making sure basic
>> 2281 user/kernel boundary testing is working. If it fails to load,
>> 2282 a regression has been detected in the user/kernel memory boundary
>> 2283 protections.
>> 2284
>> 2285 If unsure, say N.
>> 2286
2510 config TEST_BPF 2287 config TEST_BPF
2511 tristate "Test BPF filter functionali 2288 tristate "Test BPF filter functionality"
2512 depends on m && NET 2289 depends on m && NET
2513 help 2290 help
2514 This builds the "test_bpf" module t 2291 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 2292 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 2293 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 2294 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 2295 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 2296 verifier used by user space verifier testsuite.
2520 2297
2521 If unsure, say N. 2298 If unsure, say N.
2522 2299
2523 config TEST_BLACKHOLE_DEV 2300 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 2301 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 2302 depends on m && NET
2526 help 2303 help
2527 This builds the "test_blackhole_dev 2304 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 2305 data path through this blackhole netdev.
2529 2306
2530 If unsure, say N. 2307 If unsure, say N.
2531 2308
2532 config FIND_BIT_BENCHMARK 2309 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 2310 tristate "Test find_bit functions"
2534 help 2311 help
2535 This builds the "test_find_bit" mod 2312 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2313 functions performance.
2537 2314
2538 If unsure, say N. 2315 If unsure, say N.
2539 2316
2540 config TEST_FIRMWARE 2317 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2318 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2319 depends on FW_LOADER
2543 help 2320 help
2544 This builds the "test_firmware" mod 2321 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2322 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2323 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2324 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2325 userspace.
2549 2326
2550 If unsure, say N. 2327 If unsure, say N.
2551 2328
2552 config TEST_SYSCTL 2329 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2330 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2331 depends on PROC_SYSCTL
2555 help 2332 help
2556 This builds the "test_sysctl" modul 2333 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2334 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2335 production knobs which might alter system functionality.
2559 2336
2560 If unsure, say N. 2337 If unsure, say N.
2561 2338
2562 config BITFIELD_KUNIT 2339 config BITFIELD_KUNIT
2563 tristate "KUnit test bitfield functio !! 2340 tristate "KUnit test bitfield functions at runtime"
2564 depends on KUNIT 2341 depends on KUNIT
2565 default KUNIT_ALL_TESTS <<
2566 help 2342 help
2567 Enable this option to test the bitf 2343 Enable this option to test the bitfield functions at boot.
2568 2344
2569 KUnit tests run during boot and out 2345 KUnit tests run during boot and output the results to the debug log
2570 in TAP format (http://testanything. 2346 in TAP format (http://testanything.org/). Only useful for kernel devs
2571 running the KUnit test harness, and 2347 running the KUnit test harness, and not intended for inclusion into a
2572 production build. 2348 production build.
2573 2349
2574 For more information on KUnit and u 2350 For more information on KUnit and unit tests in general please refer
2575 to the KUnit documentation in Docum 2351 to the KUnit documentation in Documentation/dev-tools/kunit/.
2576 2352
2577 If unsure, say N. 2353 If unsure, say N.
2578 2354
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 2355 config RESOURCE_KUNIT_TEST
2616 tristate "KUnit test for resource API !! 2356 tristate "KUnit test for resource API"
2617 depends on KUNIT 2357 depends on KUNIT
2618 default KUNIT_ALL_TESTS <<
2619 help 2358 help
2620 This builds the resource API unit t 2359 This builds the resource API unit test.
2621 Tests the logic of API provided by 2360 Tests the logic of API provided by resource.c and ioport.h.
2622 For more information on KUnit and u 2361 For more information on KUnit and unit tests in general please refer
2623 to the KUnit documentation in Docum 2362 to the KUnit documentation in Documentation/dev-tools/kunit/.
2624 2363
2625 If unsure, say N. 2364 If unsure, say N.
2626 2365
2627 config SYSCTL_KUNIT_TEST 2366 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! 2367 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629 depends on KUNIT 2368 depends on KUNIT
2630 default KUNIT_ALL_TESTS 2369 default KUNIT_ALL_TESTS
2631 help 2370 help
2632 This builds the proc sysctl unit te 2371 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2372 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2373 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2374 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2375
2637 If unsure, say N. 2376 If unsure, say N.
2638 2377
2639 config LIST_KUNIT_TEST 2378 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke 2379 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641 depends on KUNIT 2380 depends on KUNIT
2642 default KUNIT_ALL_TESTS 2381 default KUNIT_ALL_TESTS
2643 help 2382 help
2644 This builds the linked list KUnit t 2383 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2384 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2385 and associated macros.
2647 2386
2648 KUnit tests run during boot and out 2387 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything 2388 in TAP format (https://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2389 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2390 production build.
2652 2391
2653 For more information on KUnit and u 2392 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2393 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2394
2656 If unsure, say N. 2395 If unsure, say N.
2657 2396
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 2397 config LINEAR_RANGES_TEST
2672 tristate "KUnit test for linear_range 2398 tristate "KUnit test for linear_ranges"
2673 depends on KUNIT 2399 depends on KUNIT
2674 select LINEAR_RANGES 2400 select LINEAR_RANGES
2675 help 2401 help
2676 This builds the linear_ranges unit 2402 This builds the linear_ranges unit test, which runs on boot.
2677 Tests the linear_ranges logic corre 2403 Tests the linear_ranges logic correctness.
2678 For more information on KUnit and u 2404 For more information on KUnit and unit tests in general please refer
2679 to the KUnit documentation in Docum 2405 to the KUnit documentation in Documentation/dev-tools/kunit/.
2680 2406
2681 If unsure, say N. 2407 If unsure, say N.
2682 2408
2683 config CMDLINE_KUNIT_TEST 2409 config CMDLINE_KUNIT_TEST
2684 tristate "KUnit test for cmdline API" !! 2410 tristate "KUnit test for cmdline API"
2685 depends on KUNIT 2411 depends on KUNIT
2686 default KUNIT_ALL_TESTS <<
2687 help 2412 help
2688 This builds the cmdline API unit te 2413 This builds the cmdline API unit test.
2689 Tests the logic of API provided by 2414 Tests the logic of API provided by cmdline.c.
2690 For more information on KUnit and u 2415 For more information on KUnit and unit tests in general please refer
2691 to the KUnit documentation in Docum 2416 to the KUnit documentation in Documentation/dev-tools/kunit/.
2692 2417
2693 If unsure, say N. 2418 If unsure, say N.
2694 2419
2695 config BITS_TEST 2420 config BITS_TEST
2696 tristate "KUnit test for bits.h" if ! !! 2421 tristate "KUnit test for bits.h"
2697 depends on KUNIT 2422 depends on KUNIT
2698 default KUNIT_ALL_TESTS <<
2699 help 2423 help
2700 This builds the bits unit test. 2424 This builds the bits unit test.
2701 Tests the logic of macros defined i 2425 Tests the logic of macros defined in bits.h.
2702 For more information on KUnit and u 2426 For more information on KUnit and unit tests in general please refer
2703 to the KUnit documentation in Docum 2427 to the KUnit documentation in Documentation/dev-tools/kunit/.
2704 2428
2705 If unsure, say N. 2429 If unsure, say N.
2706 2430
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 2431 config TEST_UDELAY
2817 tristate "udelay test driver" 2432 tristate "udelay test driver"
2818 help 2433 help
2819 This builds the "udelay_test" modul 2434 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2435 that udelay() is working properly.
2821 2436
2822 If unsure, say N. 2437 If unsure, say N.
2823 2438
2824 config TEST_STATIC_KEYS 2439 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2440 tristate "Test static keys"
2826 depends on m 2441 depends on m
2827 help 2442 help
2828 Test the static key interfaces. 2443 Test the static key interfaces.
2829 2444
2830 If unsure, say N. 2445 If unsure, say N.
2831 2446
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 2447 config TEST_KMOD
2843 tristate "kmod stress tester" 2448 tristate "kmod stress tester"
2844 depends on m 2449 depends on m
2845 depends on NETDEVICES && NET_CORE && 2450 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2451 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB <<
2848 select TEST_LKM 2452 select TEST_LKM
2849 select XFS_FS 2453 select XFS_FS
2850 select TUN 2454 select TUN
2851 select BTRFS_FS 2455 select BTRFS_FS
2852 help 2456 help
2853 Test the kernel's module loading me 2457 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2458 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2459 This test provides a series of tests against kmod.
2856 2460
2857 Although technically you can either 2461 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2462 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2463 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2464 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2465 module load requests, ultimately this could be fatal.
2862 2466
2863 To run tests run: 2467 To run tests run:
2864 2468
2865 tools/testing/selftests/kmod/kmod.s 2469 tools/testing/selftests/kmod/kmod.sh --help
2866 2470
2867 If unsure, say N. 2471 If unsure, say N.
2868 2472
2869 config TEST_DEBUG_VIRTUAL 2473 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2474 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2475 depends on DEBUG_VIRTUAL
2872 help 2476 help
2873 Test the kernel's ability to detect 2477 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2478 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2479 kernel's virtual address map.
2876 2480
2877 If unsure, say N. 2481 If unsure, say N.
2878 2482
2879 config TEST_MEMCAT_P 2483 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2484 tristate "Test memcat_p() helper function"
2881 help 2485 help
2882 Test the memcat_p() helper for corr 2486 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2487 pointer arrays together.
2884 2488
2885 If unsure, say N. 2489 If unsure, say N.
2886 2490
>> 2491 config TEST_LIVEPATCH
>> 2492 tristate "Test livepatching"
>> 2493 default n
>> 2494 depends on DYNAMIC_DEBUG
>> 2495 depends on LIVEPATCH
>> 2496 depends on m
>> 2497 help
>> 2498 Test kernel livepatching features for correctness. The tests will
>> 2499 load test modules that will be livepatched in various scenarios.
>> 2500
>> 2501 To run all the livepatching tests:
>> 2502
>> 2503 make -C tools/testing/selftests TARGETS=livepatch run_tests
>> 2504
>> 2505 Alternatively, individual tests may be invoked:
>> 2506
>> 2507 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2508 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2509 tools/testing/selftests/livepatch/test-shadow-vars.sh
>> 2510
>> 2511 If unsure, say N.
>> 2512
2887 config TEST_OBJAGG 2513 config TEST_OBJAGG
2888 tristate "Perform selftest on object 2514 tristate "Perform selftest on object aggreration manager"
2889 default n 2515 default n
2890 depends on OBJAGG 2516 depends on OBJAGG
2891 help 2517 help
2892 Enable this option to test object a 2518 Enable this option to test object aggregation manager on boot
2893 (or module load). 2519 (or module load).
2894 2520
>> 2521
>> 2522 config TEST_STACKINIT
>> 2523 tristate "Test level of stack variable initialization"
>> 2524 help
>> 2525 Test if the kernel is zero-initializing stack variables and
>> 2526 padding. Coverage is controlled by compiler flags,
>> 2527 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
>> 2528 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
>> 2529
>> 2530 If unsure, say N.
>> 2531
2895 config TEST_MEMINIT 2532 config TEST_MEMINIT
2896 tristate "Test heap/page initializati 2533 tristate "Test heap/page initialization"
2897 help 2534 help
2898 Test if the kernel is zero-initiali 2535 Test if the kernel is zero-initializing heap and page allocations.
2899 This can be useful to test init_on_ 2536 This can be useful to test init_on_alloc and init_on_free features.
2900 2537
2901 If unsure, say N. 2538 If unsure, say N.
2902 2539
2903 config TEST_HMM 2540 config TEST_HMM
2904 tristate "Test HMM (Heterogeneous Mem 2541 tristate "Test HMM (Heterogeneous Memory Management)"
2905 depends on TRANSPARENT_HUGEPAGE 2542 depends on TRANSPARENT_HUGEPAGE
2906 depends on DEVICE_PRIVATE 2543 depends on DEVICE_PRIVATE
2907 select HMM_MIRROR 2544 select HMM_MIRROR
2908 select MMU_NOTIFIER 2545 select MMU_NOTIFIER
2909 help 2546 help
2910 This is a pseudo device driver sole 2547 This is a pseudo device driver solely for testing HMM.
2911 Say M here if you want to build the 2548 Say M here if you want to build the HMM test module.
2912 Doing so will allow you to run tool 2549 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913 2550
2914 If unsure, say N. 2551 If unsure, say N.
2915 2552
2916 config TEST_FREE_PAGES 2553 config TEST_FREE_PAGES
2917 tristate "Test freeing pages" 2554 tristate "Test freeing pages"
2918 help 2555 help
2919 Test that a memory leak does not oc 2556 Test that a memory leak does not occur due to a race between
2920 freeing a block of pages and a spec 2557 freeing a block of pages and a speculative page reference.
2921 Loading this module is safe if your 2558 Loading this module is safe if your kernel has the bug fixed.
2922 If the bug is not fixed, it will le 2559 If the bug is not fixed, it will leak gigabytes of memory and
2923 probably OOM your system. 2560 probably OOM your system.
2924 2561
2925 config TEST_FPU 2562 config TEST_FPU
2926 tristate "Test floating point operati 2563 tristate "Test floating point operations in kernel space"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2564 depends on X86 && !KCOV_INSTRUMENT_ALL
2928 help 2565 help
2929 Enable this option to add /sys/kern 2566 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930 which will trigger a sequence of fl 2567 which will trigger a sequence of floating point operations. This is used
2931 for self-testing floating point con 2568 for self-testing floating point control register setting in
2932 kernel_fpu_begin(). 2569 kernel_fpu_begin().
2933 2570
2934 If unsure, say N. 2571 If unsure, say N.
2935 2572
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 2573 endif # RUNTIME_TESTING_MENU
2960 2574
2961 config ARCH_USE_MEMTEST 2575 config ARCH_USE_MEMTEST
2962 bool 2576 bool
2963 help 2577 help
2964 An architecture should select this 2578 An architecture should select this when it uses early_memtest()
2965 during boot process. 2579 during boot process.
2966 2580
2967 config MEMTEST 2581 config MEMTEST
2968 bool "Memtest" 2582 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST 2583 depends on ARCH_USE_MEMTEST
2970 help 2584 help
2971 This option adds a kernel parameter 2585 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. 2586 to be set and executed.
2973 memtest=0, mean disabled; -- 2587 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2588 memtest=1, mean do 1 test pattern;
2975 ... 2589 ...
2976 memtest=17, mean do 17 test p 2590 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2591 If you are unsure how to answer this question, answer N.
2978 2592
2979 2593
2980 2594
2981 config HYPERV_TESTING 2595 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2596 bool "Microsoft Hyper-V driver testing"
2983 default n 2597 default n
2984 depends on HYPERV && DEBUG_FS 2598 depends on HYPERV && DEBUG_FS
2985 help 2599 help
2986 Select this option to enable Hyper- 2600 Select this option to enable Hyper-V vmbus testing.
2987 2601
2988 endmenu # "Kernel Testing and Coverage" 2602 endmenu # "Kernel Testing and Coverage"
2989 2603
2990 menu "Rust hacking" !! 2604 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 2605
3053 endmenu # Kernel hacking 2606 endmenu # Kernel hacking
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