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 38 config STACKTRACE_BUILD_ID
39 bool "Show build ID information in sta 39 bool "Show build ID information in stacktraces"
40 depends on PRINTK 40 depends on PRINTK
41 help 41 help
42 Selecting this option adds build ID 42 Selecting this option adds build ID information for symbols in
43 stacktraces printed with the printk 43 stacktraces printed with the printk format '%p[SR]b'.
44 44
45 This option is intended for distros 45 This option is intended for distros where debuginfo is not easily
46 accessible but can be downloaded giv 46 accessible but can be downloaded given the build ID of the vmlinux or
47 kernel module where the function is 47 kernel module where the function is located.
48 48
49 config CONSOLE_LOGLEVEL_DEFAULT 49 config CONSOLE_LOGLEVEL_DEFAULT
50 int "Default console loglevel (1-15)" 50 int "Default console loglevel (1-15)"
51 range 1 15 51 range 1 15
52 default "7" 52 default "7"
53 help 53 help
54 Default loglevel to determine what w 54 Default loglevel to determine what will be printed on the console.
55 55
56 Setting a default here is equivalent 56 Setting a default here is equivalent to passing in loglevel=<x> in
57 the kernel bootargs. loglevel=<x> co 57 the kernel bootargs. loglevel=<x> continues to override whatever
58 value is specified here as well. 58 value is specified here as well.
59 59
60 Note: This does not affect the log l 60 Note: This does not affect the log level of un-prefixed printk()
61 usage in the kernel. That is control 61 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
62 option. 62 option.
63 63
64 config CONSOLE_LOGLEVEL_QUIET 64 config CONSOLE_LOGLEVEL_QUIET
65 int "quiet console loglevel (1-15)" 65 int "quiet console loglevel (1-15)"
66 range 1 15 66 range 1 15
67 default "4" 67 default "4"
68 help 68 help
69 loglevel to use when "quiet" is pass 69 loglevel to use when "quiet" is passed on the kernel commandline.
70 70
71 When "quiet" is passed on the kernel 71 When "quiet" is passed on the kernel commandline this loglevel
72 will be used as the loglevel. IOW pa 72 will be used as the loglevel. IOW passing "quiet" will be the
73 equivalent of passing "loglevel=<CON 73 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
74 74
75 config MESSAGE_LOGLEVEL_DEFAULT 75 config MESSAGE_LOGLEVEL_DEFAULT
76 int "Default message log level (1-7)" 76 int "Default message log level (1-7)"
77 range 1 7 77 range 1 7
78 default "4" 78 default "4"
79 help 79 help
80 Default log level for printk stateme 80 Default log level for printk statements with no specified priority.
81 81
82 This was hard-coded to KERN_WARNING 82 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
83 that are auditing their logs closely 83 that are auditing their logs closely may want to set it to a lower
84 priority. 84 priority.
85 85
86 Note: This does not affect what mess 86 Note: This does not affect what message level gets printed on the console
87 by default. To change that, use logl 87 by default. To change that, use loglevel=<x> in the kernel bootargs,
88 or pick a different CONSOLE_LOGLEVEL 88 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
89 89
90 config BOOT_PRINTK_DELAY 90 config BOOT_PRINTK_DELAY
91 bool "Delay each boot printk message b 91 bool "Delay each boot printk message by N milliseconds"
92 depends on DEBUG_KERNEL && PRINTK && G 92 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
93 help 93 help
94 This build option allows you to read 94 This build option allows you to read kernel boot messages
95 by inserting a short delay after eac 95 by inserting a short delay after each one. The delay is
96 specified in milliseconds on the ker 96 specified in milliseconds on the kernel command line,
97 using "boot_delay=N". 97 using "boot_delay=N".
98 98
99 It is likely that you would also nee 99 It is likely that you would also need to use "lpj=M" to preset
100 the "loops per jiffie" value. 100 the "loops per jiffie" value.
101 See a previous boot log for the "lpj 101 See a previous boot log for the "lpj" value to use for your
102 system, and then set "lpj=M" before 102 system, and then set "lpj=M" before setting "boot_delay=N".
103 NOTE: Using this option may adverse 103 NOTE: Using this option may adversely affect SMP systems.
104 I.e., processors other than the firs 104 I.e., processors other than the first one may not boot up.
105 BOOT_PRINTK_DELAY also may cause LOC 105 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
106 what it believes to be lockup condit 106 what it believes to be lockup conditions.
107 107
108 config DYNAMIC_DEBUG 108 config DYNAMIC_DEBUG
109 bool "Enable dynamic printk() support" 109 bool "Enable dynamic printk() support"
110 default n 110 default n
111 depends on PRINTK 111 depends on PRINTK
112 depends on (DEBUG_FS || PROC_FS) 112 depends on (DEBUG_FS || PROC_FS)
113 select DYNAMIC_DEBUG_CORE 113 select DYNAMIC_DEBUG_CORE
114 help 114 help
115 115
116 Compiles debug level messages into t 116 Compiles debug level messages into the kernel, which would not
117 otherwise be available at runtime. T 117 otherwise be available at runtime. These messages can then be
118 enabled/disabled based on various le 118 enabled/disabled based on various levels of scope - per source file,
119 function, module, format string, and 119 function, module, format string, and line number. This mechanism
120 implicitly compiles in all pr_debug( 120 implicitly compiles in all pr_debug() and dev_dbg() calls, which
121 enlarges the kernel text size by abo 121 enlarges the kernel text size by about 2%.
122 122
123 If a source file is compiled with DE 123 If a source file is compiled with DEBUG flag set, any
124 pr_debug() calls in it are enabled b 124 pr_debug() calls in it are enabled by default, but can be
125 disabled at runtime as below. Note 125 disabled at runtime as below. Note that DEBUG flag is
126 turned on by many CONFIG_*DEBUG* opt 126 turned on by many CONFIG_*DEBUG* options.
127 127
128 Usage: 128 Usage:
129 129
130 Dynamic debugging is controlled via 130 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
131 which is contained in the 'debugfs' 131 which is contained in the 'debugfs' filesystem or procfs.
132 Thus, the debugfs or procfs filesyst 132 Thus, the debugfs or procfs filesystem must first be mounted before
133 making use of this feature. 133 making use of this feature.
134 We refer the control file as: <debug 134 We refer the control file as: <debugfs>/dynamic_debug/control. This
135 file contains a list of the debug st 135 file contains a list of the debug statements that can be enabled. The
136 format for each line of the file is: 136 format for each line of the file is:
137 137
138 filename:lineno [module]functi 138 filename:lineno [module]function flags format
139 139
140 filename : source file of the debug 140 filename : source file of the debug statement
141 lineno : line number of the debug st 141 lineno : line number of the debug statement
142 module : module that contains the de 142 module : module that contains the debug statement
143 function : function that contains th 143 function : function that contains the debug statement
144 flags : '=p' means the line is turne 144 flags : '=p' means the line is turned 'on' for printing
145 format : the format used for the deb 145 format : the format used for the debug statement
146 146
147 From a live system: 147 From a live system:
148 148
149 nullarbor:~ # cat <debugfs>/dy 149 nullarbor:~ # cat <debugfs>/dynamic_debug/control
150 # filename:lineno [module]func 150 # filename:lineno [module]function flags format
151 fs/aio.c:222 [aio]__put_ioctx 151 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
152 fs/aio.c:248 [aio]ioctx_alloc 152 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
153 fs/aio.c:1770 [aio]sys_io_canc 153 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
154 154
155 Example usage: 155 Example usage:
156 156
157 // enable the message at line 157 // enable the message at line 1603 of file svcsock.c
158 nullarbor:~ # echo -n 'file sv 158 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
159 159 <debugfs>/dynamic_debug/control
160 160
161 // enable all the messages in 161 // enable all the messages in file svcsock.c
162 nullarbor:~ # echo -n 'file sv 162 nullarbor:~ # echo -n 'file svcsock.c +p' >
163 163 <debugfs>/dynamic_debug/control
164 164
165 // enable all the messages in 165 // enable all the messages in the NFS server module
166 nullarbor:~ # echo -n 'module 166 nullarbor:~ # echo -n 'module nfsd +p' >
167 167 <debugfs>/dynamic_debug/control
168 168
169 // enable all 12 messages in t 169 // enable all 12 messages in the function svc_process()
170 nullarbor:~ # echo -n 'func sv 170 nullarbor:~ # echo -n 'func svc_process +p' >
171 171 <debugfs>/dynamic_debug/control
172 172
173 // disable all 12 messages in 173 // disable all 12 messages in the function svc_process()
174 nullarbor:~ # echo -n 'func sv 174 nullarbor:~ # echo -n 'func svc_process -p' >
175 175 <debugfs>/dynamic_debug/control
176 176
177 See Documentation/admin-guide/dynami 177 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
178 information. 178 information.
179 179
180 config DYNAMIC_DEBUG_CORE 180 config DYNAMIC_DEBUG_CORE
181 bool "Enable core function of dynamic 181 bool "Enable core function of dynamic debug support"
182 depends on PRINTK 182 depends on PRINTK
183 depends on (DEBUG_FS || PROC_FS) 183 depends on (DEBUG_FS || PROC_FS)
184 help 184 help
185 Enable core functional support of dy 185 Enable core functional support of dynamic debug. It is useful
186 when you want to tie dynamic debug t 186 when you want to tie dynamic debug to your kernel modules with
187 DYNAMIC_DEBUG_MODULE defined for eac 187 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
188 the case of embedded system where th 188 the case of embedded system where the kernel image size is
189 sensitive for people. 189 sensitive for people.
190 190
191 config SYMBOLIC_ERRNAME 191 config SYMBOLIC_ERRNAME
192 bool "Support symbolic error names in 192 bool "Support symbolic error names in printf"
193 default y if PRINTK 193 default y if PRINTK
194 help 194 help
195 If you say Y here, the kernel's prin 195 If you say Y here, the kernel's printf implementation will
196 be able to print symbolic error name 196 be able to print symbolic error names such as ENOSPC instead
197 of the number 28. It makes the kerne 197 of the number 28. It makes the kernel image slightly larger
198 (about 3KB), but can make the kernel 198 (about 3KB), but can make the kernel logs easier to read.
199 199
200 config DEBUG_BUGVERBOSE 200 config DEBUG_BUGVERBOSE
201 bool "Verbose BUG() reporting (adds 70 201 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
202 depends on BUG && (GENERIC_BUG || HAVE 202 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
203 default y 203 default y
204 help 204 help
205 Say Y here to make BUG() panics outp 205 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 206 of the BUG call as well as the EIP and oops trace. This aids
207 debugging but costs about 70-100K of 207 debugging but costs about 70-100K of memory.
208 208
209 endmenu # "printk and dmesg options" 209 endmenu # "printk and dmesg options"
210 210
211 config DEBUG_KERNEL 211 config DEBUG_KERNEL
212 bool "Kernel debugging" 212 bool "Kernel debugging"
213 help 213 help
214 Say Y here if you are developing dri 214 Say Y here if you are developing drivers or trying to debug and
215 identify kernel problems. 215 identify kernel problems.
216 216
217 config DEBUG_MISC 217 config DEBUG_MISC
218 bool "Miscellaneous debug code" 218 bool "Miscellaneous debug code"
219 default DEBUG_KERNEL 219 default DEBUG_KERNEL
220 depends on DEBUG_KERNEL 220 depends on DEBUG_KERNEL
221 help 221 help
222 Say Y here if you need to enable mis 222 Say Y here if you need to enable miscellaneous debug code that should
223 be under a more specific debug optio 223 be under a more specific debug option but isn't.
224 224
225 menu "Compile-time checks and compiler options 225 menu "Compile-time checks and compiler options"
226 226
227 config DEBUG_INFO 227 config DEBUG_INFO
228 bool 228 bool
229 help 229 help
230 A kernel debug info option other tha 230 A kernel debug info option other than "None" has been selected
231 in the "Debug information" choice be 231 in the "Debug information" choice below, indicating that debug
232 information will be generated for bu 232 information will be generated for build targets.
233 233
234 # Clang generates .uleb128 with label differen !! 234 # Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which
235 # older binutils ports do not support when uti !! 235 # some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
236 # relaxation: https://sourceware.org/bugzilla/ !! 236 config AS_HAS_NON_CONST_LEB128
237 config AS_HAS_NON_CONST_ULEB128 <<
238 def_bool $(as-instr,.uleb128 .Lexpr_en 237 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
239 238
240 choice 239 choice
241 prompt "Debug information" 240 prompt "Debug information"
242 depends on DEBUG_KERNEL 241 depends on DEBUG_KERNEL
243 help 242 help
244 Selecting something other than "None 243 Selecting something other than "None" results in a kernel image
245 that will include debugging info res 244 that will include debugging info resulting in a larger kernel image.
246 This adds debug symbols to the kerne 245 This adds debug symbols to the kernel and modules (gcc -g), and
247 is needed if you intend to use kerne 246 is needed if you intend to use kernel crashdump or binary object
248 tools like crash, kgdb, LKCD, gdb, e 247 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
249 248
250 Choose which version of DWARF debug 249 Choose which version of DWARF debug info to emit. If unsure,
251 select "Toolchain default". 250 select "Toolchain default".
252 251
253 config DEBUG_INFO_NONE 252 config DEBUG_INFO_NONE
254 bool "Disable debug information" 253 bool "Disable debug information"
255 help 254 help
256 Do not build the kernel with debuggi 255 Do not build the kernel with debugging information, which will
257 result in a faster and smaller build 256 result in a faster and smaller build.
258 257
259 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT 258 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
260 bool "Rely on the toolchain's implicit 259 bool "Rely on the toolchain's implicit default DWARF version"
261 select DEBUG_INFO 260 select DEBUG_INFO
262 depends on !CC_IS_CLANG || AS_IS_LLVM !! 261 depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
263 help 262 help
264 The implicit default version of DWAR 263 The implicit default version of DWARF debug info produced by a
265 toolchain changes over time. 264 toolchain changes over time.
266 265
267 This can break consumers of the debu 266 This can break consumers of the debug info that haven't upgraded to
268 support newer revisions, and prevent 267 support newer revisions, and prevent testing newer versions, but
269 those should be less common scenario 268 those should be less common scenarios.
270 269
271 config DEBUG_INFO_DWARF4 270 config DEBUG_INFO_DWARF4
272 bool "Generate DWARF Version 4 debugin 271 bool "Generate DWARF Version 4 debuginfo"
273 select DEBUG_INFO 272 select DEBUG_INFO
274 depends on !CC_IS_CLANG || AS_IS_LLVM 273 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
275 help 274 help
276 Generate DWARF v4 debug info. This r 275 Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
277 if using clang without clang's integ 276 if using clang without clang's integrated assembler, and gdb 7.0+.
278 277
279 If you have consumers of DWARF debug 278 If you have consumers of DWARF debug info that are not ready for
280 newer revisions of DWARF, you may wi 279 newer revisions of DWARF, you may wish to choose this or have your
281 config select this. 280 config select this.
282 281
283 config DEBUG_INFO_DWARF5 282 config DEBUG_INFO_DWARF5
284 bool "Generate DWARF Version 5 debugin 283 bool "Generate DWARF Version 5 debuginfo"
285 select DEBUG_INFO 284 select DEBUG_INFO
286 depends on !ARCH_HAS_BROKEN_DWARF5 !! 285 depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128)
287 depends on !CC_IS_CLANG || AS_IS_LLVM <<
288 help 286 help
289 Generate DWARF v5 debug info. Requir 287 Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
290 5.0+ accepts the -gdwarf-5 flag but 288 5.0+ accepts the -gdwarf-5 flag but only had partial support for some
291 draft features until 7.0), and gdb 8 289 draft features until 7.0), and gdb 8.0+.
292 290
293 Changes to the structure of debug in 291 Changes to the structure of debug info in Version 5 allow for around
294 15-18% savings in resulting image an 292 15-18% savings in resulting image and debug info section sizes as
295 compared to DWARF Version 4. DWARF V 293 compared to DWARF Version 4. DWARF Version 5 standardizes previous
296 extensions such as accelerators for 294 extensions such as accelerators for symbol indexing and the format
297 for fission (.dwo/.dwp) files. Users 295 for fission (.dwo/.dwp) files. Users may not want to select this
298 config if they rely on tooling that 296 config if they rely on tooling that has not yet been updated to
299 support DWARF Version 5. 297 support DWARF Version 5.
300 298
301 endchoice # "Debug information" 299 endchoice # "Debug information"
302 300
303 if DEBUG_INFO 301 if DEBUG_INFO
304 302
305 config DEBUG_INFO_REDUCED 303 config DEBUG_INFO_REDUCED
306 bool "Reduce debugging information" 304 bool "Reduce debugging information"
307 help 305 help
308 If you say Y here gcc is instructed 306 If you say Y here gcc is instructed to generate less debugging
309 information for structure types. Thi 307 information for structure types. This means that tools that
310 need full debugging information (lik 308 need full debugging information (like kgdb or systemtap) won't
311 be happy. But if you merely need deb 309 be happy. But if you merely need debugging information to
312 resolve line numbers there is no los 310 resolve line numbers there is no loss. Advantage is that
313 build directory object sizes shrink 311 build directory object sizes shrink dramatically over a full
314 DEBUG_INFO build and compile times a 312 DEBUG_INFO build and compile times are reduced too.
315 Only works with newer gcc versions. 313 Only works with newer gcc versions.
316 314
317 choice 315 choice
318 prompt "Compressed Debug information" 316 prompt "Compressed Debug information"
319 help 317 help
320 Compress the resulting debug info. R 318 Compress the resulting debug info. Results in smaller debug info sections,
321 but requires that consumers are able 319 but requires that consumers are able to decompress the results.
322 320
323 If unsure, choose DEBUG_INFO_COMPRES 321 If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
324 322
325 config DEBUG_INFO_COMPRESSED_NONE 323 config DEBUG_INFO_COMPRESSED_NONE
326 bool "Don't compress debug information 324 bool "Don't compress debug information"
327 help 325 help
328 Don't compress debug info sections. 326 Don't compress debug info sections.
329 327
330 config DEBUG_INFO_COMPRESSED_ZLIB 328 config DEBUG_INFO_COMPRESSED_ZLIB
331 bool "Compress debugging information w 329 bool "Compress debugging information with zlib"
332 depends on $(cc-option,-gz=zlib) 330 depends on $(cc-option,-gz=zlib)
333 depends on $(ld-option,--compress-debu 331 depends on $(ld-option,--compress-debug-sections=zlib)
334 help 332 help
335 Compress the debug information using 333 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
336 5.0+, binutils 2.26+, and zlib. 334 5.0+, binutils 2.26+, and zlib.
337 335
338 Users of dpkg-deb via scripts/packag 336 Users of dpkg-deb via scripts/package/builddeb may find an increase in
339 size of their debug .deb packages wi 337 size of their debug .deb packages with this config set, due to the
340 debug info being compressed with zli 338 debug info being compressed with zlib, then the object files being
341 recompressed with a different compre 339 recompressed with a different compression scheme. But this is still
342 preferable to setting $KDEB_COMPRESS 340 preferable to setting $KDEB_COMPRESS to "none" which would be even
343 larger. 341 larger.
344 342
345 config DEBUG_INFO_COMPRESSED_ZSTD 343 config DEBUG_INFO_COMPRESSED_ZSTD
346 bool "Compress debugging information w 344 bool "Compress debugging information with zstd"
347 depends on $(cc-option,-gz=zstd) 345 depends on $(cc-option,-gz=zstd)
348 depends on $(ld-option,--compress-debu 346 depends on $(ld-option,--compress-debug-sections=zstd)
349 help 347 help
350 Compress the debug information using 348 Compress the debug information using zstd. This may provide better
351 compression than zlib, for about the 349 compression than zlib, for about the same time costs, but requires newer
352 toolchain support. Requires GCC 13. 350 toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
353 zstd. 351 zstd.
354 352
355 endchoice # "Compressed Debug information" 353 endchoice # "Compressed Debug information"
356 354
357 config DEBUG_INFO_SPLIT 355 config DEBUG_INFO_SPLIT
358 bool "Produce split debuginfo in .dwo 356 bool "Produce split debuginfo in .dwo files"
359 depends on $(cc-option,-gsplit-dwarf) 357 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 358 help
366 Generate debug info into separate .d 359 Generate debug info into separate .dwo files. This significantly
367 reduces the build directory size for 360 reduces the build directory size for builds with DEBUG_INFO,
368 because it stores the information on 361 because it stores the information only once on disk in .dwo
369 files instead of multiple times in o 362 files instead of multiple times in object files and executables.
370 In addition the debug information is 363 In addition the debug information is also compressed.
371 364
372 Requires recent gcc (4.7+) and recen 365 Requires recent gcc (4.7+) and recent gdb/binutils.
373 Any tool that packages or reads debu 366 Any tool that packages or reads debug information would need
374 to know about the .dwo files and inc 367 to know about the .dwo files and include them.
375 Incompatible with older versions of 368 Incompatible with older versions of ccache.
376 369
377 config DEBUG_INFO_BTF 370 config DEBUG_INFO_BTF
378 bool "Generate BTF type information" !! 371 bool "Generate BTF typeinfo"
379 depends on !DEBUG_INFO_SPLIT && !DEBUG 372 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
380 depends on !GCC_PLUGIN_RANDSTRUCT || C 373 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
381 depends on BPF_SYSCALL 374 depends on BPF_SYSCALL
382 depends on !DEBUG_INFO_DWARF5 || PAHOL 375 depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
383 # pahole uses elfutils, which does not <<
384 depends on !HEXAGON <<
385 help 376 help
386 Generate deduplicated BTF type infor 377 Generate deduplicated BTF type information from DWARF debug info.
387 Turning this on expects presence of 378 Turning this on expects presence of pahole tool, which will convert
388 DWARF type info into equivalent dedu 379 DWARF type info into equivalent deduplicated BTF type info.
389 380
390 config PAHOLE_HAS_SPLIT_BTF 381 config PAHOLE_HAS_SPLIT_BTF
391 def_bool PAHOLE_VERSION >= 119 382 def_bool PAHOLE_VERSION >= 119
392 383
393 config PAHOLE_HAS_BTF_TAG 384 config PAHOLE_HAS_BTF_TAG
394 def_bool PAHOLE_VERSION >= 123 385 def_bool PAHOLE_VERSION >= 123
395 depends on CC_IS_CLANG 386 depends on CC_IS_CLANG
396 help 387 help
397 Decide whether pahole emits btf_tag 388 Decide whether pahole emits btf_tag attributes (btf_type_tag and
398 btf_decl_tag) or not. Currently only 389 btf_decl_tag) or not. Currently only clang compiler implements
399 these attributes, so make the config 390 these attributes, so make the config depend on CC_IS_CLANG.
400 391
401 config PAHOLE_HAS_LANG_EXCLUDE 392 config PAHOLE_HAS_LANG_EXCLUDE
402 def_bool PAHOLE_VERSION >= 124 393 def_bool PAHOLE_VERSION >= 124
403 help 394 help
404 Support for the --lang_exclude flag 395 Support for the --lang_exclude flag which makes pahole exclude
405 compilation units from the supplied 396 compilation units from the supplied language. Used in Kbuild to
406 omit Rust CUs which are not supporte 397 omit Rust CUs which are not supported in version 1.24 of pahole,
407 otherwise it would emit malformed ke 398 otherwise it would emit malformed kernel and module binaries when
408 using DEBUG_INFO_BTF_MODULES. 399 using DEBUG_INFO_BTF_MODULES.
409 400
410 config DEBUG_INFO_BTF_MODULES 401 config DEBUG_INFO_BTF_MODULES
411 bool "Generate BTF type information fo !! 402 def_bool y
412 default y <<
413 depends on DEBUG_INFO_BTF && MODULES & 403 depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
414 help 404 help
415 Generate compact split BTF type info 405 Generate compact split BTF type information for kernel modules.
416 406
417 config MODULE_ALLOW_BTF_MISMATCH 407 config MODULE_ALLOW_BTF_MISMATCH
418 bool "Allow loading modules with non-m 408 bool "Allow loading modules with non-matching BTF type info"
419 depends on DEBUG_INFO_BTF_MODULES 409 depends on DEBUG_INFO_BTF_MODULES
420 help 410 help
421 For modules whose split BTF does not 411 For modules whose split BTF does not match vmlinux, load without
422 BTF rather than refusing to load. Th 412 BTF rather than refusing to load. The default behavior with
423 module BTF enabled is to reject modu 413 module BTF enabled is to reject modules with such mismatches;
424 this option will still load module B 414 this option will still load module BTF where possible but ignore
425 it when a mismatch is found. 415 it when a mismatch is found.
426 416
427 config GDB_SCRIPTS 417 config GDB_SCRIPTS
428 bool "Provide GDB scripts for kernel d 418 bool "Provide GDB scripts for kernel debugging"
429 help 419 help
430 This creates the required links to G 420 This creates the required links to GDB helper scripts in the
431 build directory. If you load vmlinux 421 build directory. If you load vmlinux into gdb, the helper
432 scripts will be automatically import 422 scripts will be automatically imported by gdb as well, and
433 additional functions are available t 423 additional functions are available to analyze a Linux kernel
434 instance. See Documentation/dev-tool 424 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
435 for further details. 425 for further details.
436 426
437 endif # DEBUG_INFO 427 endif # DEBUG_INFO
438 428
439 config FRAME_WARN 429 config FRAME_WARN
440 int "Warn for stack frames larger than 430 int "Warn for stack frames larger than"
441 range 0 8192 431 range 0 8192
442 default 0 if KMSAN 432 default 0 if KMSAN
443 default 2048 if GCC_PLUGIN_LATENT_ENTR 433 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
444 default 2048 if PARISC 434 default 2048 if PARISC
445 default 1536 if (!64BIT && XTENSA) 435 default 1536 if (!64BIT && XTENSA)
446 default 1280 if KASAN && !64BIT 436 default 1280 if KASAN && !64BIT
447 default 1024 if !64BIT 437 default 1024 if !64BIT
448 default 2048 if 64BIT 438 default 2048 if 64BIT
449 help 439 help
450 Tell the compiler to warn at build t 440 Tell the compiler to warn at build time for stack frames larger than this.
451 Setting this too low will cause a lo 441 Setting this too low will cause a lot of warnings.
452 Setting it to 0 disables the warning 442 Setting it to 0 disables the warning.
453 443
454 config STRIP_ASM_SYMS 444 config STRIP_ASM_SYMS
455 bool "Strip assembler-generated symbol 445 bool "Strip assembler-generated symbols during link"
456 default n 446 default n
457 help 447 help
458 Strip internal assembler-generated s 448 Strip internal assembler-generated symbols during a link (symbols
459 that look like '.Lxxx') so they don' 449 that look like '.Lxxx') so they don't pollute the output of
460 get_wchan() and suchlike. 450 get_wchan() and suchlike.
461 451
462 config READABLE_ASM 452 config READABLE_ASM
463 bool "Generate readable assembler code 453 bool "Generate readable assembler code"
464 depends on DEBUG_KERNEL 454 depends on DEBUG_KERNEL
465 depends on CC_IS_GCC 455 depends on CC_IS_GCC
466 help 456 help
467 Disable some compiler optimizations 457 Disable some compiler optimizations that tend to generate human unreadable
468 assembler output. This may make the 458 assembler output. This may make the kernel slightly slower, but it helps
469 to keep kernel developers who have t 459 to keep kernel developers who have to stare a lot at assembler listings
470 sane. 460 sane.
471 461
472 config HEADERS_INSTALL 462 config HEADERS_INSTALL
473 bool "Install uapi headers to usr/incl 463 bool "Install uapi headers to usr/include"
474 depends on !UML 464 depends on !UML
475 help 465 help
476 This option will install uapi header 466 This option will install uapi headers (headers exported to user-space)
477 into the usr/include directory for u 467 into the usr/include directory for use during the kernel build.
478 This is unneeded for building the ke 468 This is unneeded for building the kernel itself, but needed for some
479 user-space program samples. It is al 469 user-space program samples. It is also needed by some features such
480 as uapi header sanity checks. 470 as uapi header sanity checks.
481 471
482 config DEBUG_SECTION_MISMATCH 472 config DEBUG_SECTION_MISMATCH
483 bool "Enable full Section mismatch ana 473 bool "Enable full Section mismatch analysis"
484 depends on CC_IS_GCC 474 depends on CC_IS_GCC
485 help 475 help
486 The section mismatch analysis checks 476 The section mismatch analysis checks if there are illegal
487 references from one section to anoth 477 references from one section to another section.
488 During linktime or runtime, some sec 478 During linktime or runtime, some sections are dropped;
489 any use of code/data previously in t 479 any use of code/data previously in these sections would
490 most likely result in an oops. 480 most likely result in an oops.
491 In the code, functions and variables 481 In the code, functions and variables are annotated with
492 __init,, etc. (see the full list in 482 __init,, etc. (see the full list in include/linux/init.h),
493 which results in the code/data being 483 which results in the code/data being placed in specific sections.
494 The section mismatch analysis is alw 484 The section mismatch analysis is always performed after a full
495 kernel build, and enabling this opti 485 kernel build, and enabling this option causes the following
496 additional step to occur: 486 additional step to occur:
497 - Add the option -fno-inline-functio 487 - Add the option -fno-inline-functions-called-once to gcc commands.
498 When inlining a function annotated 488 When inlining a function annotated with __init in a non-init
499 function, we would lose the sectio 489 function, we would lose the section information and thus
500 the analysis would not catch the i 490 the analysis would not catch the illegal reference.
501 This option tells gcc to inline le 491 This option tells gcc to inline less (but it does result in
502 a larger kernel). 492 a larger kernel).
503 493
504 config SECTION_MISMATCH_WARN_ONLY 494 config SECTION_MISMATCH_WARN_ONLY
505 bool "Make section mismatch errors non 495 bool "Make section mismatch errors non-fatal"
506 default y 496 default y
507 help 497 help
508 If you say N here, the build process 498 If you say N here, the build process will fail if there are any
509 section mismatch, instead of just th 499 section mismatch, instead of just throwing warnings.
510 500
511 If unsure, say Y. 501 If unsure, say Y.
512 502
513 config DEBUG_FORCE_FUNCTION_ALIGN_64B 503 config DEBUG_FORCE_FUNCTION_ALIGN_64B
514 bool "Force all function address 64B a 504 bool "Force all function address 64B aligned"
515 depends on EXPERT && (X86_64 || ARM64 !! 505 depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
516 select FUNCTION_ALIGNMENT_64B 506 select FUNCTION_ALIGNMENT_64B
517 help 507 help
518 There are cases that a commit from o 508 There are cases that a commit from one domain changes the function
519 address alignment of other domains, 509 address alignment of other domains, and cause magic performance
520 bump (regression or improvement). En 510 bump (regression or improvement). Enable this option will help to
521 verify if the bump is caused by func 511 verify if the bump is caused by function alignment changes, while
522 it will slightly increase the kernel 512 it will slightly increase the kernel size and affect icache usage.
523 513
524 It is mainly for debug and performan 514 It is mainly for debug and performance tuning use.
525 515
526 # 516 #
527 # Select this config option from the architect 517 # Select this config option from the architecture Kconfig, if it
528 # is preferred to always offer frame pointers 518 # is preferred to always offer frame pointers as a config
529 # option on the architecture (regardless of KE 519 # option on the architecture (regardless of KERNEL_DEBUG):
530 # 520 #
531 config ARCH_WANT_FRAME_POINTERS 521 config ARCH_WANT_FRAME_POINTERS
532 bool 522 bool
533 523
534 config FRAME_POINTER 524 config FRAME_POINTER
535 bool "Compile the kernel with frame po 525 bool "Compile the kernel with frame pointers"
536 depends on DEBUG_KERNEL && (M68K || UM 526 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
537 default y if (DEBUG_INFO && UML) || AR 527 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
538 help 528 help
539 If you say Y here the resulting kern 529 If you say Y here the resulting kernel image will be slightly
540 larger and slower, but it gives very 530 larger and slower, but it gives very useful debugging information
541 in case of kernel bugs. (precise oop 531 in case of kernel bugs. (precise oopses/stacktraces/warnings)
542 532
543 config OBJTOOL 533 config OBJTOOL
544 bool 534 bool
545 535
546 config STACK_VALIDATION 536 config STACK_VALIDATION
547 bool "Compile-time stack metadata vali 537 bool "Compile-time stack metadata validation"
548 depends on HAVE_STACK_VALIDATION && UN 538 depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
549 select OBJTOOL 539 select OBJTOOL
550 default n 540 default n
551 help 541 help
552 Validate frame pointer rules at comp 542 Validate frame pointer rules at compile-time. This helps ensure that
553 runtime stack traces are more reliab 543 runtime stack traces are more reliable.
554 544
555 For more information, see 545 For more information, see
556 tools/objtool/Documentation/objtool. 546 tools/objtool/Documentation/objtool.txt.
557 547
558 config NOINSTR_VALIDATION 548 config NOINSTR_VALIDATION
559 bool 549 bool
560 depends on HAVE_NOINSTR_VALIDATION && 550 depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
561 select OBJTOOL 551 select OBJTOOL
562 default y 552 default y
563 553
564 config VMLINUX_MAP 554 config VMLINUX_MAP
565 bool "Generate vmlinux.map file when l 555 bool "Generate vmlinux.map file when linking"
566 depends on EXPERT 556 depends on EXPERT
567 help 557 help
568 Selecting this option will pass "-Ma 558 Selecting this option will pass "-Map=vmlinux.map" to ld
569 when linking vmlinux. That file can 559 when linking vmlinux. That file can be useful for verifying
570 and debugging magic section games, a 560 and debugging magic section games, and for seeing which
571 pieces of code get eliminated with 561 pieces of code get eliminated with
572 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION 562 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
573 563
574 config DEBUG_FORCE_WEAK_PER_CPU 564 config DEBUG_FORCE_WEAK_PER_CPU
575 bool "Force weak per-cpu definitions" 565 bool "Force weak per-cpu definitions"
576 depends on DEBUG_KERNEL 566 depends on DEBUG_KERNEL
577 help 567 help
578 s390 and alpha require percpu variab 568 s390 and alpha require percpu variables in modules to be
579 defined weak to work around addressi 569 defined weak to work around addressing range issue which
580 puts the following two restrictions 570 puts the following two restrictions on percpu variable
581 definitions. 571 definitions.
582 572
583 1. percpu symbols must be unique whe 573 1. percpu symbols must be unique whether static or not
584 2. percpu variables can't be defined 574 2. percpu variables can't be defined inside a function
585 575
586 To ensure that generic code follows 576 To ensure that generic code follows the above rules, this
587 option forces all percpu variables t 577 option forces all percpu variables to be defined as weak.
588 578
589 endmenu # "Compiler options" 579 endmenu # "Compiler options"
590 580
591 menu "Generic Kernel Debugging Instruments" 581 menu "Generic Kernel Debugging Instruments"
592 582
593 config MAGIC_SYSRQ 583 config MAGIC_SYSRQ
594 bool "Magic SysRq key" 584 bool "Magic SysRq key"
595 depends on !UML 585 depends on !UML
596 help 586 help
597 If you say Y here, you will have som 587 If you say Y here, you will have some control over the system even
598 if the system crashes for example du 588 if the system crashes for example during kernel debugging (e.g., you
599 will be able to flush the buffer cac 589 will be able to flush the buffer cache to disk, reboot the system
600 immediately or dump some status info 590 immediately or dump some status information). This is accomplished
601 by pressing various keys while holdi 591 by pressing various keys while holding SysRq (Alt+PrintScreen). It
602 also works on a serial console (on P 592 also works on a serial console (on PC hardware at least), if you
603 send a BREAK and then within 5 secon 593 send a BREAK and then within 5 seconds a command keypress. The
604 keys are documented in <file:Documen 594 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
605 Don't say Y unless you really know w 595 Don't say Y unless you really know what this hack does.
606 596
607 config MAGIC_SYSRQ_DEFAULT_ENABLE 597 config MAGIC_SYSRQ_DEFAULT_ENABLE
608 hex "Enable magic SysRq key functions 598 hex "Enable magic SysRq key functions by default"
609 depends on MAGIC_SYSRQ 599 depends on MAGIC_SYSRQ
610 default 0x1 600 default 0x1
611 help 601 help
612 Specifies which SysRq key functions 602 Specifies which SysRq key functions are enabled by default.
613 This may be set to 1 or 0 to enable 603 This may be set to 1 or 0 to enable or disable them all, or
614 to a bitmask as described in Documen 604 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
615 605
616 config MAGIC_SYSRQ_SERIAL 606 config MAGIC_SYSRQ_SERIAL
617 bool "Enable magic SysRq key over seri 607 bool "Enable magic SysRq key over serial"
618 depends on MAGIC_SYSRQ 608 depends on MAGIC_SYSRQ
619 default y 609 default y
620 help 610 help
621 Many embedded boards have a disconne 611 Many embedded boards have a disconnected TTL level serial which can
622 generate some garbage that can lead 612 generate some garbage that can lead to spurious false sysrq detects.
623 This option allows you to decide whe 613 This option allows you to decide whether you want to enable the
624 magic SysRq key. 614 magic SysRq key.
625 615
626 config MAGIC_SYSRQ_SERIAL_SEQUENCE 616 config MAGIC_SYSRQ_SERIAL_SEQUENCE
627 string "Char sequence that enables mag 617 string "Char sequence that enables magic SysRq over serial"
628 depends on MAGIC_SYSRQ_SERIAL 618 depends on MAGIC_SYSRQ_SERIAL
629 default "" 619 default ""
630 help 620 help
631 Specifies a sequence of characters t 621 Specifies a sequence of characters that can follow BREAK to enable
632 SysRq on a serial console. 622 SysRq on a serial console.
633 623
634 If unsure, leave an empty string and 624 If unsure, leave an empty string and the option will not be enabled.
635 625
636 config DEBUG_FS 626 config DEBUG_FS
637 bool "Debug Filesystem" 627 bool "Debug Filesystem"
638 help 628 help
639 debugfs is a virtual file system tha 629 debugfs is a virtual file system that kernel developers use to put
640 debugging files into. Enable this o 630 debugging files into. Enable this option to be able to read and
641 write to these files. 631 write to these files.
642 632
643 For detailed documentation on the de 633 For detailed documentation on the debugfs API, see
644 Documentation/filesystems/. 634 Documentation/filesystems/.
645 635
646 If unsure, say N. 636 If unsure, say N.
647 637
648 choice 638 choice
649 prompt "Debugfs default access" 639 prompt "Debugfs default access"
650 depends on DEBUG_FS 640 depends on DEBUG_FS
651 default DEBUG_FS_ALLOW_ALL 641 default DEBUG_FS_ALLOW_ALL
652 help 642 help
653 This selects the default access rest 643 This selects the default access restrictions for debugfs.
654 It can be overridden with kernel com 644 It can be overridden with kernel command line option
655 debugfs=[on,no-mount,off]. The restr 645 debugfs=[on,no-mount,off]. The restrictions apply for API access
656 and filesystem registration. 646 and filesystem registration.
657 647
658 config DEBUG_FS_ALLOW_ALL 648 config DEBUG_FS_ALLOW_ALL
659 bool "Access normal" 649 bool "Access normal"
660 help 650 help
661 No restrictions apply. Both API and 651 No restrictions apply. Both API and filesystem registration
662 is on. This is the normal default op 652 is on. This is the normal default operation.
663 653
664 config DEBUG_FS_DISALLOW_MOUNT 654 config DEBUG_FS_DISALLOW_MOUNT
665 bool "Do not register debugfs as files 655 bool "Do not register debugfs as filesystem"
666 help 656 help
667 The API is open but filesystem is no 657 The API is open but filesystem is not loaded. Clients can still do
668 their work and read with debug tools 658 their work and read with debug tools that do not need
669 debugfs filesystem. 659 debugfs filesystem.
670 660
671 config DEBUG_FS_ALLOW_NONE 661 config DEBUG_FS_ALLOW_NONE
672 bool "No access" 662 bool "No access"
673 help 663 help
674 Access is off. Clients get -PERM whe 664 Access is off. Clients get -PERM when trying to create nodes in
675 debugfs tree and debugfs is not regi 665 debugfs tree and debugfs is not registered as a filesystem.
676 Client can then back-off or continue 666 Client can then back-off or continue without debugfs access.
677 667
678 endchoice 668 endchoice
679 669
680 source "lib/Kconfig.kgdb" 670 source "lib/Kconfig.kgdb"
681 source "lib/Kconfig.ubsan" 671 source "lib/Kconfig.ubsan"
682 source "lib/Kconfig.kcsan" 672 source "lib/Kconfig.kcsan"
683 673
684 endmenu 674 endmenu
685 675
686 menu "Networking Debugging" 676 menu "Networking Debugging"
687 677
688 source "net/Kconfig.debug" 678 source "net/Kconfig.debug"
689 679
690 endmenu # "Networking Debugging" 680 endmenu # "Networking Debugging"
691 681
692 menu "Memory Debugging" 682 menu "Memory Debugging"
693 683
694 source "mm/Kconfig.debug" 684 source "mm/Kconfig.debug"
695 685
696 config DEBUG_OBJECTS 686 config DEBUG_OBJECTS
697 bool "Debug object operations" 687 bool "Debug object operations"
698 depends on DEBUG_KERNEL 688 depends on DEBUG_KERNEL
699 help 689 help
700 If you say Y here, additional code w 690 If you say Y here, additional code will be inserted into the
701 kernel to track the life time of var 691 kernel to track the life time of various objects and validate
702 the operations on those objects. 692 the operations on those objects.
703 693
704 config DEBUG_OBJECTS_SELFTEST 694 config DEBUG_OBJECTS_SELFTEST
705 bool "Debug objects selftest" 695 bool "Debug objects selftest"
706 depends on DEBUG_OBJECTS 696 depends on DEBUG_OBJECTS
707 help 697 help
708 This enables the selftest of the obj 698 This enables the selftest of the object debug code.
709 699
710 config DEBUG_OBJECTS_FREE 700 config DEBUG_OBJECTS_FREE
711 bool "Debug objects in freed memory" 701 bool "Debug objects in freed memory"
712 depends on DEBUG_OBJECTS 702 depends on DEBUG_OBJECTS
713 help 703 help
714 This enables checks whether a k/v fr 704 This enables checks whether a k/v free operation frees an area
715 which contains an object which has n 705 which contains an object which has not been deactivated
716 properly. This can make kmalloc/kfre 706 properly. This can make kmalloc/kfree-intensive workloads
717 much slower. 707 much slower.
718 708
719 config DEBUG_OBJECTS_TIMERS 709 config DEBUG_OBJECTS_TIMERS
720 bool "Debug timer objects" 710 bool "Debug timer objects"
721 depends on DEBUG_OBJECTS 711 depends on DEBUG_OBJECTS
722 help 712 help
723 If you say Y here, additional code w 713 If you say Y here, additional code will be inserted into the
724 timer routines to track the life tim 714 timer routines to track the life time of timer objects and
725 validate the timer operations. 715 validate the timer operations.
726 716
727 config DEBUG_OBJECTS_WORK 717 config DEBUG_OBJECTS_WORK
728 bool "Debug work objects" 718 bool "Debug work objects"
729 depends on DEBUG_OBJECTS 719 depends on DEBUG_OBJECTS
730 help 720 help
731 If you say Y here, additional code w 721 If you say Y here, additional code will be inserted into the
732 work queue routines to track the lif 722 work queue routines to track the life time of work objects and
733 validate the work operations. 723 validate the work operations.
734 724
735 config DEBUG_OBJECTS_RCU_HEAD 725 config DEBUG_OBJECTS_RCU_HEAD
736 bool "Debug RCU callbacks objects" 726 bool "Debug RCU callbacks objects"
737 depends on DEBUG_OBJECTS 727 depends on DEBUG_OBJECTS
738 help 728 help
739 Enable this to turn on debugging of 729 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
740 730
741 config DEBUG_OBJECTS_PERCPU_COUNTER 731 config DEBUG_OBJECTS_PERCPU_COUNTER
742 bool "Debug percpu counter objects" 732 bool "Debug percpu counter objects"
743 depends on DEBUG_OBJECTS 733 depends on DEBUG_OBJECTS
744 help 734 help
745 If you say Y here, additional code w 735 If you say Y here, additional code will be inserted into the
746 percpu counter routines to track the 736 percpu counter routines to track the life time of percpu counter
747 objects and validate the percpu coun 737 objects and validate the percpu counter operations.
748 738
749 config DEBUG_OBJECTS_ENABLE_DEFAULT 739 config DEBUG_OBJECTS_ENABLE_DEFAULT
750 int "debug_objects bootup default valu 740 int "debug_objects bootup default value (0-1)"
751 range 0 1 741 range 0 1
752 default "1" 742 default "1"
753 depends on DEBUG_OBJECTS 743 depends on DEBUG_OBJECTS
754 help 744 help
755 Debug objects boot parameter default 745 Debug objects boot parameter default value
756 746
757 config SHRINKER_DEBUG 747 config SHRINKER_DEBUG
758 bool "Enable shrinker debugging suppor 748 bool "Enable shrinker debugging support"
759 depends on DEBUG_FS 749 depends on DEBUG_FS
760 help 750 help
761 Say Y to enable the shrinker debugfs 751 Say Y to enable the shrinker debugfs interface which provides
762 visibility into the kernel memory sh 752 visibility into the kernel memory shrinkers subsystem.
763 Disable it to avoid an extra memory 753 Disable it to avoid an extra memory footprint.
764 754
765 config DEBUG_STACK_USAGE 755 config DEBUG_STACK_USAGE
766 bool "Stack utilization instrumentatio 756 bool "Stack utilization instrumentation"
767 depends on DEBUG_KERNEL !! 757 depends on DEBUG_KERNEL && !IA64
768 help 758 help
769 Enables the display of the minimum a 759 Enables the display of the minimum amount of free stack which each
770 task has ever had available in the s 760 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 <<
773 761
774 This option will slow down process c 762 This option will slow down process creation somewhat.
775 763
776 config SCHED_STACK_END_CHECK 764 config SCHED_STACK_END_CHECK
777 bool "Detect stack corruption on calls 765 bool "Detect stack corruption on calls to schedule()"
778 depends on DEBUG_KERNEL 766 depends on DEBUG_KERNEL
779 default n 767 default n
780 help 768 help
781 This option checks for a stack overr 769 This option checks for a stack overrun on calls to schedule().
782 If the stack end location is found t 770 If the stack end location is found to be over written always panic as
783 the content of the corrupted region 771 the content of the corrupted region can no longer be trusted.
784 This is to ensure no erroneous behav 772 This is to ensure no erroneous behaviour occurs which could result in
785 data corruption or a sporadic crash 773 data corruption or a sporadic crash at a later stage once the region
786 is examined. The runtime overhead in 774 is examined. The runtime overhead introduced is minimal.
787 775
788 config ARCH_HAS_DEBUG_VM_PGTABLE 776 config ARCH_HAS_DEBUG_VM_PGTABLE
789 bool 777 bool
790 help 778 help
791 An architecture should select this w 779 An architecture should select this when it can successfully
792 build and run DEBUG_VM_PGTABLE. 780 build and run DEBUG_VM_PGTABLE.
793 781
794 config DEBUG_VM_IRQSOFF 782 config DEBUG_VM_IRQSOFF
795 def_bool DEBUG_VM && !PREEMPT_RT 783 def_bool DEBUG_VM && !PREEMPT_RT
796 784
797 config DEBUG_VM 785 config DEBUG_VM
798 bool "Debug VM" 786 bool "Debug VM"
799 depends on DEBUG_KERNEL 787 depends on DEBUG_KERNEL
800 help 788 help
801 Enable this to turn on extended chec 789 Enable this to turn on extended checks in the virtual-memory system
802 that may impact performance. 790 that may impact performance.
803 791
804 If unsure, say N. 792 If unsure, say N.
805 793
806 config DEBUG_VM_SHOOT_LAZIES <<
807 bool "Debug MMU_LAZY_TLB_SHOOTDOWN imp <<
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 794 config DEBUG_VM_MAPLE_TREE
817 bool "Debug VM maple trees" 795 bool "Debug VM maple trees"
818 depends on DEBUG_VM 796 depends on DEBUG_VM
819 select DEBUG_MAPLE_TREE 797 select DEBUG_MAPLE_TREE
820 help 798 help
821 Enable VM maple tree debugging infor 799 Enable VM maple tree debugging information and extra validations.
822 800
823 If unsure, say N. 801 If unsure, say N.
824 802
825 config DEBUG_VM_RB 803 config DEBUG_VM_RB
826 bool "Debug VM red-black trees" 804 bool "Debug VM red-black trees"
827 depends on DEBUG_VM 805 depends on DEBUG_VM
828 help 806 help
829 Enable VM red-black tree debugging i 807 Enable VM red-black tree debugging information and extra validations.
830 808
831 If unsure, say N. 809 If unsure, say N.
832 810
833 config DEBUG_VM_PGFLAGS 811 config DEBUG_VM_PGFLAGS
834 bool "Debug page-flags operations" 812 bool "Debug page-flags operations"
835 depends on DEBUG_VM 813 depends on DEBUG_VM
836 help 814 help
837 Enables extra validation on page fla 815 Enables extra validation on page flags operations.
838 816
839 If unsure, say N. 817 If unsure, say N.
840 818
841 config DEBUG_VM_PGTABLE 819 config DEBUG_VM_PGTABLE
842 bool "Debug arch page table for semant 820 bool "Debug arch page table for semantics compliance"
843 depends on MMU 821 depends on MMU
844 depends on ARCH_HAS_DEBUG_VM_PGTABLE 822 depends on ARCH_HAS_DEBUG_VM_PGTABLE
845 default y if DEBUG_VM 823 default y if DEBUG_VM
846 help 824 help
847 This option provides a debug method 825 This option provides a debug method which can be used to test
848 architecture page table helper funct 826 architecture page table helper functions on various platforms in
849 verifying if they comply with expect 827 verifying if they comply with expected generic MM semantics. This
850 will help architecture code in makin 828 will help architecture code in making sure that any changes or
851 new additions of these helpers still 829 new additions of these helpers still conform to expected
852 semantics of the generic MM. Platfor 830 semantics of the generic MM. Platforms will have to opt in for
853 this through ARCH_HAS_DEBUG_VM_PGTAB 831 this through ARCH_HAS_DEBUG_VM_PGTABLE.
854 832
855 If unsure, say N. 833 If unsure, say N.
856 834
857 config ARCH_HAS_DEBUG_VIRTUAL 835 config ARCH_HAS_DEBUG_VIRTUAL
858 bool 836 bool
859 837
860 config DEBUG_VIRTUAL 838 config DEBUG_VIRTUAL
861 bool "Debug VM translations" 839 bool "Debug VM translations"
862 depends on DEBUG_KERNEL && ARCH_HAS_DE 840 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
863 help 841 help
864 Enable some costly sanity checks in 842 Enable some costly sanity checks in virtual to page code. This can
865 catch mistakes with virt_to_page() a 843 catch mistakes with virt_to_page() and friends.
866 844
867 If unsure, say N. 845 If unsure, say N.
868 846
869 config DEBUG_NOMMU_REGIONS 847 config DEBUG_NOMMU_REGIONS
870 bool "Debug the global anon/private NO 848 bool "Debug the global anon/private NOMMU mapping region tree"
871 depends on DEBUG_KERNEL && !MMU 849 depends on DEBUG_KERNEL && !MMU
872 help 850 help
873 This option causes the global tree o 851 This option causes the global tree of anonymous and private mapping
874 regions to be regularly checked for 852 regions to be regularly checked for invalid topology.
875 853
876 config DEBUG_MEMORY_INIT 854 config DEBUG_MEMORY_INIT
877 bool "Debug memory initialisation" if 855 bool "Debug memory initialisation" if EXPERT
878 default !EXPERT 856 default !EXPERT
879 help 857 help
880 Enable this for additional checks du 858 Enable this for additional checks during memory initialisation.
881 The sanity checks verify aspects of 859 The sanity checks verify aspects of the VM such as the memory model
882 and other information provided by th 860 and other information provided by the architecture. Verbose
883 information will be printed at KERN_ 861 information will be printed at KERN_DEBUG loglevel depending
884 on the mminit_loglevel= command-line 862 on the mminit_loglevel= command-line option.
885 863
886 If unsure, say Y 864 If unsure, say Y
887 865
888 config MEMORY_NOTIFIER_ERROR_INJECT 866 config MEMORY_NOTIFIER_ERROR_INJECT
889 tristate "Memory hotplug notifier erro 867 tristate "Memory hotplug notifier error injection module"
890 depends on MEMORY_HOTPLUG && NOTIFIER_ 868 depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
891 help 869 help
892 This option provides the ability to 870 This option provides the ability to inject artificial errors to
893 memory hotplug notifier chain callba 871 memory hotplug notifier chain callbacks. It is controlled through
894 debugfs interface under /sys/kernel/ 872 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
895 873
896 If the notifier call chain should be 874 If the notifier call chain should be failed with some events
897 notified, write the error code to "a 875 notified, write the error code to "actions/<notifier event>/error".
898 876
899 Example: Inject memory hotplug offli 877 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
900 878
901 # cd /sys/kernel/debug/notifier-erro 879 # cd /sys/kernel/debug/notifier-error-inject/memory
902 # echo -12 > actions/MEM_GOING_OFFLI 880 # echo -12 > actions/MEM_GOING_OFFLINE/error
903 # echo offline > /sys/devices/system 881 # echo offline > /sys/devices/system/memory/memoryXXX/state
904 bash: echo: write error: Cannot allo 882 bash: echo: write error: Cannot allocate memory
905 883
906 To compile this code as a module, ch 884 To compile this code as a module, choose M here: the module will
907 be called memory-notifier-error-inje 885 be called memory-notifier-error-inject.
908 886
909 If unsure, say N. 887 If unsure, say N.
910 888
911 config DEBUG_PER_CPU_MAPS 889 config DEBUG_PER_CPU_MAPS
912 bool "Debug access to per_cpu maps" 890 bool "Debug access to per_cpu maps"
913 depends on DEBUG_KERNEL 891 depends on DEBUG_KERNEL
914 depends on SMP 892 depends on SMP
915 help 893 help
916 Say Y to verify that the per_cpu map 894 Say Y to verify that the per_cpu map being accessed has
917 been set up. This adds a fair amount 895 been set up. This adds a fair amount of code to kernel memory
918 and decreases performance. 896 and decreases performance.
919 897
920 Say N if unsure. 898 Say N if unsure.
921 899
922 config DEBUG_KMAP_LOCAL 900 config DEBUG_KMAP_LOCAL
923 bool "Debug kmap_local temporary mappi 901 bool "Debug kmap_local temporary mappings"
924 depends on DEBUG_KERNEL && KMAP_LOCAL 902 depends on DEBUG_KERNEL && KMAP_LOCAL
925 help 903 help
926 This option enables additional error 904 This option enables additional error checking for the kmap_local
927 infrastructure. Disable for product 905 infrastructure. Disable for production use.
928 906
929 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP 907 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
930 bool 908 bool
931 909
932 config DEBUG_KMAP_LOCAL_FORCE_MAP 910 config DEBUG_KMAP_LOCAL_FORCE_MAP
933 bool "Enforce kmap_local temporary map 911 bool "Enforce kmap_local temporary mappings"
934 depends on DEBUG_KERNEL && ARCH_SUPPOR 912 depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
935 select KMAP_LOCAL 913 select KMAP_LOCAL
936 select DEBUG_KMAP_LOCAL 914 select DEBUG_KMAP_LOCAL
937 help 915 help
938 This option enforces temporary mappi 916 This option enforces temporary mappings through the kmap_local
939 mechanism for non-highmem pages and 917 mechanism for non-highmem pages and on non-highmem systems.
940 Disable this for production systems! 918 Disable this for production systems!
941 919
942 config DEBUG_HIGHMEM 920 config DEBUG_HIGHMEM
943 bool "Highmem debugging" 921 bool "Highmem debugging"
944 depends on DEBUG_KERNEL && HIGHMEM 922 depends on DEBUG_KERNEL && HIGHMEM
945 select DEBUG_KMAP_LOCAL_FORCE_MAP if A 923 select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
946 select DEBUG_KMAP_LOCAL 924 select DEBUG_KMAP_LOCAL
947 help 925 help
948 This option enables additional error 926 This option enables additional error checking for high memory
949 systems. Disable for production sys 927 systems. Disable for production systems.
950 928
951 config HAVE_DEBUG_STACKOVERFLOW 929 config HAVE_DEBUG_STACKOVERFLOW
952 bool 930 bool
953 931
954 config DEBUG_STACKOVERFLOW 932 config DEBUG_STACKOVERFLOW
955 bool "Check for stack overflows" 933 bool "Check for stack overflows"
956 depends on DEBUG_KERNEL && HAVE_DEBUG_ 934 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
957 help 935 help
958 Say Y here if you want to check for 936 Say Y here if you want to check for overflows of kernel, IRQ
959 and exception stacks (if your archit 937 and exception stacks (if your architecture uses them). This
960 option will show detailed messages i 938 option will show detailed messages if free stack space drops
961 below a certain limit. 939 below a certain limit.
962 940
963 These kinds of bugs usually occur wh 941 These kinds of bugs usually occur when call-chains in the
964 kernel get too deep, especially when 942 kernel get too deep, especially when interrupts are
965 involved. 943 involved.
966 944
967 Use this in cases where you see appa 945 Use this in cases where you see apparently random memory
968 corruption, especially if it appears 946 corruption, especially if it appears in 'struct thread_info'
969 947
970 If in doubt, say "N". 948 If in doubt, say "N".
971 949
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" 950 source "lib/Kconfig.kasan"
1004 source "lib/Kconfig.kfence" 951 source "lib/Kconfig.kfence"
1005 source "lib/Kconfig.kmsan" 952 source "lib/Kconfig.kmsan"
1006 953
1007 endmenu # "Memory Debugging" 954 endmenu # "Memory Debugging"
1008 955
1009 config DEBUG_SHIRQ 956 config DEBUG_SHIRQ
1010 bool "Debug shared IRQ handlers" 957 bool "Debug shared IRQ handlers"
1011 depends on DEBUG_KERNEL 958 depends on DEBUG_KERNEL
1012 help 959 help
1013 Enable this to generate a spurious 960 Enable this to generate a spurious interrupt just before a shared
1014 interrupt handler is deregistered ( 961 interrupt handler is deregistered (generating one when registering
1015 is currently disabled). Drivers nee 962 is currently disabled). Drivers need to handle this correctly. Some
1016 don't and need to be caught. 963 don't and need to be caught.
1017 964
1018 menu "Debug Oops, Lockups and Hangs" 965 menu "Debug Oops, Lockups and Hangs"
1019 966
1020 config PANIC_ON_OOPS 967 config PANIC_ON_OOPS
1021 bool "Panic on Oops" 968 bool "Panic on Oops"
1022 help 969 help
1023 Say Y here to enable the kernel to 970 Say Y here to enable the kernel to panic when it oopses. This
1024 has the same effect as setting oops 971 has the same effect as setting oops=panic on the kernel command
1025 line. 972 line.
1026 973
1027 This feature is useful to ensure th 974 This feature is useful to ensure that the kernel does not do
1028 anything erroneous after an oops wh 975 anything erroneous after an oops which could result in data
1029 corruption or other issues. 976 corruption or other issues.
1030 977
1031 Say N if unsure. 978 Say N if unsure.
1032 979
1033 config PANIC_ON_OOPS_VALUE 980 config PANIC_ON_OOPS_VALUE
1034 int 981 int
1035 range 0 1 982 range 0 1
1036 default 0 if !PANIC_ON_OOPS 983 default 0 if !PANIC_ON_OOPS
1037 default 1 if PANIC_ON_OOPS 984 default 1 if PANIC_ON_OOPS
1038 985
1039 config PANIC_TIMEOUT 986 config PANIC_TIMEOUT
1040 int "panic timeout" 987 int "panic timeout"
1041 default 0 988 default 0
1042 help 989 help
1043 Set the timeout value (in seconds) 990 Set the timeout value (in seconds) until a reboot occurs when
1044 the kernel panics. If n = 0, then w 991 the kernel panics. If n = 0, then we wait forever. A timeout
1045 value n > 0 will wait n seconds bef 992 value n > 0 will wait n seconds before rebooting, while a timeout
1046 value n < 0 will reboot immediately !! 993 value n < 0 will reboot immediately.
1047 with the kernel command line option <<
1048 /proc/sys/kernel/panic. <<
1049 994
1050 config LOCKUP_DETECTOR 995 config LOCKUP_DETECTOR
1051 bool 996 bool
1052 997
1053 config SOFTLOCKUP_DETECTOR 998 config SOFTLOCKUP_DETECTOR
1054 bool "Detect Soft Lockups" 999 bool "Detect Soft Lockups"
1055 depends on DEBUG_KERNEL && !S390 1000 depends on DEBUG_KERNEL && !S390
1056 select LOCKUP_DETECTOR 1001 select LOCKUP_DETECTOR
1057 help 1002 help
1058 Say Y here to enable the kernel to 1003 Say Y here to enable the kernel to act as a watchdog to detect
1059 soft lockups. 1004 soft lockups.
1060 1005
1061 Softlockups are bugs that cause the 1006 Softlockups are bugs that cause the kernel to loop in kernel
1062 mode for more than 20 seconds, with 1007 mode for more than 20 seconds, without giving other tasks a
1063 chance to run. The current stack t 1008 chance to run. The current stack trace is displayed upon
1064 detection and the system will stay 1009 detection and the system will stay locked up.
1065 1010
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 1011 config BOOTPARAM_SOFTLOCKUP_PANIC
1081 bool "Panic (Reboot) On Soft Lockups" 1012 bool "Panic (Reboot) On Soft Lockups"
1082 depends on SOFTLOCKUP_DETECTOR 1013 depends on SOFTLOCKUP_DETECTOR
1083 help 1014 help
1084 Say Y here to enable the kernel to 1015 Say Y here to enable the kernel to panic on "soft lockups",
1085 which are bugs that cause the kerne 1016 which are bugs that cause the kernel to loop in kernel
1086 mode for more than 20 seconds (conf 1017 mode for more than 20 seconds (configurable using the watchdog_thresh
1087 sysctl), without giving other tasks 1018 sysctl), without giving other tasks a chance to run.
1088 1019
1089 The panic can be used in combinatio 1020 The panic can be used in combination with panic_timeout,
1090 to cause the system to reboot autom 1021 to cause the system to reboot automatically after a
1091 lockup has been detected. This feat 1022 lockup has been detected. This feature is useful for
1092 high-availability systems that have 1023 high-availability systems that have uptime guarantees and
1093 where a lockup must be resolved ASA 1024 where a lockup must be resolved ASAP.
1094 1025
1095 Say N if unsure. 1026 Say N if unsure.
1096 1027
1097 config HAVE_HARDLOCKUP_DETECTOR_BUDDY !! 1028 config HARDLOCKUP_DETECTOR_PERF
1098 bool 1029 bool
1099 depends on SMP !! 1030 select SOFTLOCKUP_DETECTOR
1100 default y <<
1101 1031
1102 # 1032 #
1103 # Global switch whether to build a hardlockup !! 1033 # Enables a timestamp based low pass filter to compensate for perf based
1104 # only when the architecture supports at leas !! 1034 # hard lockup detection which runs too fast due to turbo modes.
1105 # two exceptions. The hardlockup detector is <<
1106 # 1035 #
1107 # s390: it reported many false positive !! 1036 config HARDLOCKUP_CHECK_TIMESTAMP
>> 1037 bool
>> 1038
1108 # 1039 #
1109 # sparc64: has a custom implementation !! 1040 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
1110 # hardlockup command line optio !! 1041 # lockup detector rather than the perf based detector.
1111 # 1042 #
1112 config HARDLOCKUP_DETECTOR 1043 config HARDLOCKUP_DETECTOR
1113 bool "Detect Hard Lockups" 1044 bool "Detect Hard Lockups"
1114 depends on DEBUG_KERNEL && !S390 && ! !! 1045 depends on DEBUG_KERNEL && !S390
1115 depends on HAVE_HARDLOCKUP_DETECTOR_P !! 1046 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 1047 select LOCKUP_DETECTOR
1120 !! 1048 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
1121 help 1049 help
1122 Say Y here to enable the kernel to 1050 Say Y here to enable the kernel to act as a watchdog to detect
1123 hard lockups. 1051 hard lockups.
1124 1052
1125 Hardlockups are bugs that cause the 1053 Hardlockups are bugs that cause the CPU to loop in kernel mode
1126 for more than 10 seconds, without l 1054 for more than 10 seconds, without letting other interrupts have a
1127 chance to run. The current stack t 1055 chance to run. The current stack trace is displayed upon detection
1128 and the system will stay locked up. 1056 and the system will stay locked up.
1129 1057
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 1058 config BOOTPARAM_HARDLOCKUP_PANIC
1188 bool "Panic (Reboot) On Hard Lockups" 1059 bool "Panic (Reboot) On Hard Lockups"
1189 depends on HARDLOCKUP_DETECTOR 1060 depends on HARDLOCKUP_DETECTOR
1190 help 1061 help
1191 Say Y here to enable the kernel to 1062 Say Y here to enable the kernel to panic on "hard lockups",
1192 which are bugs that cause the kerne 1063 which are bugs that cause the kernel to loop in kernel
1193 mode with interrupts disabled for m 1064 mode with interrupts disabled for more than 10 seconds (configurable
1194 using the watchdog_thresh sysctl). 1065 using the watchdog_thresh sysctl).
1195 1066
1196 Say N if unsure. 1067 Say N if unsure.
1197 1068
1198 config DETECT_HUNG_TASK 1069 config DETECT_HUNG_TASK
1199 bool "Detect Hung Tasks" 1070 bool "Detect Hung Tasks"
1200 depends on DEBUG_KERNEL 1071 depends on DEBUG_KERNEL
1201 default SOFTLOCKUP_DETECTOR 1072 default SOFTLOCKUP_DETECTOR
1202 help 1073 help
1203 Say Y here to enable the kernel to 1074 Say Y here to enable the kernel to detect "hung tasks",
1204 which are bugs that cause the task 1075 which are bugs that cause the task to be stuck in
1205 uninterruptible "D" state indefinit 1076 uninterruptible "D" state indefinitely.
1206 1077
1207 When a hung task is detected, the k 1078 When a hung task is detected, the kernel will print the
1208 current stack trace (which you shou 1079 current stack trace (which you should report), but the
1209 task will stay in uninterruptible s 1080 task will stay in uninterruptible state. If lockdep is
1210 enabled then all held locks will al 1081 enabled then all held locks will also be reported. This
1211 feature has negligible overhead. 1082 feature has negligible overhead.
1212 1083
1213 config DEFAULT_HUNG_TASK_TIMEOUT 1084 config DEFAULT_HUNG_TASK_TIMEOUT
1214 int "Default timeout for hung task de 1085 int "Default timeout for hung task detection (in seconds)"
1215 depends on DETECT_HUNG_TASK 1086 depends on DETECT_HUNG_TASK
1216 default 120 1087 default 120
1217 help 1088 help
1218 This option controls the default ti 1089 This option controls the default timeout (in seconds) used
1219 to determine when a task has become 1090 to determine when a task has become non-responsive and should
1220 be considered hung. 1091 be considered hung.
1221 1092
1222 It can be adjusted at runtime via t 1093 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1223 sysctl or by writing a value to 1094 sysctl or by writing a value to
1224 /proc/sys/kernel/hung_task_timeout_ 1095 /proc/sys/kernel/hung_task_timeout_secs.
1225 1096
1226 A timeout of 0 disables the check. 1097 A timeout of 0 disables the check. The default is two minutes.
1227 Keeping the default should be fine 1098 Keeping the default should be fine in most cases.
1228 1099
1229 config BOOTPARAM_HUNG_TASK_PANIC 1100 config BOOTPARAM_HUNG_TASK_PANIC
1230 bool "Panic (Reboot) On Hung Tasks" 1101 bool "Panic (Reboot) On Hung Tasks"
1231 depends on DETECT_HUNG_TASK 1102 depends on DETECT_HUNG_TASK
1232 help 1103 help
1233 Say Y here to enable the kernel to 1104 Say Y here to enable the kernel to panic on "hung tasks",
1234 which are bugs that cause the kerne 1105 which are bugs that cause the kernel to leave a task stuck
1235 in uninterruptible "D" state. 1106 in uninterruptible "D" state.
1236 1107
1237 The panic can be used in combinatio 1108 The panic can be used in combination with panic_timeout,
1238 to cause the system to reboot autom 1109 to cause the system to reboot automatically after a
1239 hung task has been detected. This f 1110 hung task has been detected. This feature is useful for
1240 high-availability systems that have 1111 high-availability systems that have uptime guarantees and
1241 where a hung tasks must be resolved 1112 where a hung tasks must be resolved ASAP.
1242 1113
1243 Say N if unsure. 1114 Say N if unsure.
1244 1115
1245 config WQ_WATCHDOG 1116 config WQ_WATCHDOG
1246 bool "Detect Workqueue Stalls" 1117 bool "Detect Workqueue Stalls"
1247 depends on DEBUG_KERNEL 1118 depends on DEBUG_KERNEL
1248 help 1119 help
1249 Say Y here to enable stall detectio 1120 Say Y here to enable stall detection on workqueues. If a
1250 worker pool doesn't make forward pr 1121 worker pool doesn't make forward progress on a pending work
1251 item for over a given amount of tim 1122 item for over a given amount of time, 30s by default, a
1252 warning message is printed along wi 1123 warning message is printed along with dump of workqueue
1253 state. This can be configured thro 1124 state. This can be configured through kernel parameter
1254 "workqueue.watchdog_thresh" and its 1125 "workqueue.watchdog_thresh" and its sysfs counterpart.
1255 1126
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 1127 config TEST_LOCKUP
1270 tristate "Test module to generate loc 1128 tristate "Test module to generate lockups"
1271 depends on m 1129 depends on m
1272 help 1130 help
1273 This builds the "test_lockup" modul 1131 This builds the "test_lockup" module that helps to make sure
1274 that watchdogs and lockup detectors 1132 that watchdogs and lockup detectors are working properly.
1275 1133
1276 Depending on module parameters it c 1134 Depending on module parameters it could emulate soft or hard
1277 lockup, "hung task", or locking arb 1135 lockup, "hung task", or locking arbitrary lock for a long time.
1278 Also it could generate series of lo 1136 Also it could generate series of lockups with cooling-down periods.
1279 1137
1280 If unsure, say N. 1138 If unsure, say N.
1281 1139
1282 endmenu # "Debug lockups and hangs" 1140 endmenu # "Debug lockups and hangs"
1283 1141
1284 menu "Scheduler Debugging" 1142 menu "Scheduler Debugging"
1285 1143
1286 config SCHED_DEBUG 1144 config SCHED_DEBUG
1287 bool "Collect scheduler debugging inf 1145 bool "Collect scheduler debugging info"
1288 depends on DEBUG_KERNEL && DEBUG_FS 1146 depends on DEBUG_KERNEL && DEBUG_FS
1289 default y 1147 default y
1290 help 1148 help
1291 If you say Y here, the /sys/kernel/ 1149 If you say Y here, the /sys/kernel/debug/sched file will be provided
1292 that can help debug the scheduler. 1150 that can help debug the scheduler. The runtime overhead of this
1293 option is minimal. 1151 option is minimal.
1294 1152
1295 config SCHED_INFO 1153 config SCHED_INFO
1296 bool 1154 bool
1297 default n 1155 default n
1298 1156
1299 config SCHEDSTATS 1157 config SCHEDSTATS
1300 bool "Collect scheduler statistics" 1158 bool "Collect scheduler statistics"
1301 depends on PROC_FS !! 1159 depends on DEBUG_KERNEL && PROC_FS
1302 select SCHED_INFO 1160 select SCHED_INFO
1303 help 1161 help
1304 If you say Y here, additional code 1162 If you say Y here, additional code will be inserted into the
1305 scheduler and related routines to c 1163 scheduler and related routines to collect statistics about
1306 scheduler behavior and provide them 1164 scheduler behavior and provide them in /proc/schedstat. These
1307 stats may be useful for both tuning 1165 stats may be useful for both tuning and debugging the scheduler
1308 If you aren't debugging the schedul 1166 If you aren't debugging the scheduler or trying to tune a specific
1309 application, you can say N to avoid 1167 application, you can say N to avoid the very slight overhead
1310 this adds. 1168 this adds.
1311 1169
1312 endmenu 1170 endmenu
1313 1171
1314 config DEBUG_TIMEKEEPING 1172 config DEBUG_TIMEKEEPING
1315 bool "Enable extra timekeeping sanity 1173 bool "Enable extra timekeeping sanity checking"
1316 help 1174 help
1317 This option will enable additional 1175 This option will enable additional timekeeping sanity checks
1318 which may be helpful when diagnosin 1176 which may be helpful when diagnosing issues where timekeeping
1319 problems are suspected. 1177 problems are suspected.
1320 1178
1321 This may include checks in the time 1179 This may include checks in the timekeeping hotpaths, so this
1322 option may have a (very small) perf 1180 option may have a (very small) performance impact to some
1323 workloads. 1181 workloads.
1324 1182
1325 If unsure, say N. 1183 If unsure, say N.
1326 1184
1327 config DEBUG_PREEMPT 1185 config DEBUG_PREEMPT
1328 bool "Debug preemptible kernel" 1186 bool "Debug preemptible kernel"
1329 depends on DEBUG_KERNEL && PREEMPTION 1187 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1330 help 1188 help
1331 If you say Y here then the kernel w 1189 If you say Y here then the kernel will use a debug variant of the
1332 commonly used smp_processor_id() fu 1190 commonly used smp_processor_id() function and will print warnings
1333 if kernel code uses it in a preempt 1191 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1334 will detect preemption count underf 1192 will detect preemption count underflows.
1335 1193
1336 This option has potential to introd 1194 This option has potential to introduce high runtime overhead,
1337 depending on workload as it trigger 1195 depending on workload as it triggers debugging routines for each
1338 this_cpu operation. It should only 1196 this_cpu operation. It should only be used for debugging purposes.
1339 1197
1340 menu "Lock Debugging (spinlocks, mutexes, etc 1198 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1341 1199
1342 config LOCK_DEBUGGING_SUPPORT 1200 config LOCK_DEBUGGING_SUPPORT
1343 bool 1201 bool
1344 depends on TRACE_IRQFLAGS_SUPPORT && 1202 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1345 default y 1203 default y
1346 1204
1347 config PROVE_LOCKING 1205 config PROVE_LOCKING
1348 bool "Lock debugging: prove locking c 1206 bool "Lock debugging: prove locking correctness"
1349 depends on DEBUG_KERNEL && LOCK_DEBUG 1207 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1350 select LOCKDEP 1208 select LOCKDEP
1351 select DEBUG_SPINLOCK 1209 select DEBUG_SPINLOCK
1352 select DEBUG_MUTEXES if !PREEMPT_RT 1210 select DEBUG_MUTEXES if !PREEMPT_RT
1353 select DEBUG_RT_MUTEXES if RT_MUTEXES 1211 select DEBUG_RT_MUTEXES if RT_MUTEXES
1354 select DEBUG_RWSEMS if !PREEMPT_RT !! 1212 select DEBUG_RWSEMS
1355 select DEBUG_WW_MUTEX_SLOWPATH 1213 select DEBUG_WW_MUTEX_SLOWPATH
1356 select DEBUG_LOCK_ALLOC 1214 select DEBUG_LOCK_ALLOC
1357 select PREEMPT_COUNT if !ARCH_NO_PREE 1215 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1358 select TRACE_IRQFLAGS 1216 select TRACE_IRQFLAGS
1359 default n 1217 default n
1360 help 1218 help
1361 This feature enables the kernel to p 1219 This feature enables the kernel to prove that all locking
1362 that occurs in the kernel runtime is 1220 that occurs in the kernel runtime is mathematically
1363 correct: that under no circumstance 1221 correct: that under no circumstance could an arbitrary (and
1364 not yet triggered) combination of ob 1222 not yet triggered) combination of observed locking
1365 sequences (on an arbitrary number of 1223 sequences (on an arbitrary number of CPUs, running an
1366 arbitrary number of tasks and interr 1224 arbitrary number of tasks and interrupt contexts) cause a
1367 deadlock. 1225 deadlock.
1368 1226
1369 In short, this feature enables the k 1227 In short, this feature enables the kernel to report locking
1370 related deadlocks before they actual 1228 related deadlocks before they actually occur.
1371 1229
1372 The proof does not depend on how har 1230 The proof does not depend on how hard and complex a
1373 deadlock scenario would be to trigge 1231 deadlock scenario would be to trigger: how many
1374 participant CPUs, tasks and irq-cont 1232 participant CPUs, tasks and irq-contexts would be needed
1375 for it to trigger. The proof also do 1233 for it to trigger. The proof also does not depend on
1376 timing: if a race and a resulting de 1234 timing: if a race and a resulting deadlock is possible
1377 theoretically (no matter how unlikel 1235 theoretically (no matter how unlikely the race scenario
1378 is), it will be proven so and will i 1236 is), it will be proven so and will immediately be
1379 reported by the kernel (once the eve 1237 reported by the kernel (once the event is observed that
1380 makes the deadlock theoretically pos 1238 makes the deadlock theoretically possible).
1381 1239
1382 If a deadlock is impossible (i.e. th 1240 If a deadlock is impossible (i.e. the locking rules, as
1383 observed by the kernel, are mathemat 1241 observed by the kernel, are mathematically correct), the
1384 kernel reports nothing. 1242 kernel reports nothing.
1385 1243
1386 NOTE: this feature can also be enabl 1244 NOTE: this feature can also be enabled for rwlocks, mutexes
1387 and rwsems - in which case all depen 1245 and rwsems - in which case all dependencies between these
1388 different locking variants are obser 1246 different locking variants are observed and mapped too, and
1389 the proof of observed correctness is 1247 the proof of observed correctness is also maintained for an
1390 arbitrary combination of these separ 1248 arbitrary combination of these separate locking variants.
1391 1249
1392 For more details, see Documentation/ 1250 For more details, see Documentation/locking/lockdep-design.rst.
1393 1251
1394 config PROVE_RAW_LOCK_NESTING 1252 config PROVE_RAW_LOCK_NESTING
1395 bool "Enable raw_spinlock - spinlock 1253 bool "Enable raw_spinlock - spinlock nesting checks"
1396 depends on PROVE_LOCKING 1254 depends on PROVE_LOCKING
1397 default n 1255 default n
1398 help 1256 help
1399 Enable the raw_spinlock vs. spinlock 1257 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1400 that the lock nesting rules for PREE 1258 that the lock nesting rules for PREEMPT_RT enabled kernels are
1401 not violated. 1259 not violated.
1402 1260
1403 NOTE: There are known nesting proble 1261 NOTE: There are known nesting problems. So if you enable this
1404 option expect lockdep splats until t 1262 option expect lockdep splats until these problems have been fully
1405 addressed which is work in progress. 1263 addressed which is work in progress. This config switch allows to
1406 identify and analyze these problems. 1264 identify and analyze these problems. It will be removed and the
1407 check permanently enabled once the m 1265 check permanently enabled once the main issues have been fixed.
1408 1266
1409 If unsure, select N. 1267 If unsure, select N.
1410 1268
1411 config LOCK_STAT 1269 config LOCK_STAT
1412 bool "Lock usage statistics" 1270 bool "Lock usage statistics"
1413 depends on DEBUG_KERNEL && LOCK_DEBUG 1271 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1414 select LOCKDEP 1272 select LOCKDEP
1415 select DEBUG_SPINLOCK 1273 select DEBUG_SPINLOCK
1416 select DEBUG_MUTEXES if !PREEMPT_RT 1274 select DEBUG_MUTEXES if !PREEMPT_RT
1417 select DEBUG_RT_MUTEXES if RT_MUTEXES 1275 select DEBUG_RT_MUTEXES if RT_MUTEXES
1418 select DEBUG_LOCK_ALLOC 1276 select DEBUG_LOCK_ALLOC
1419 default n 1277 default n
1420 help 1278 help
1421 This feature enables tracking lock c 1279 This feature enables tracking lock contention points
1422 1280
1423 For more details, see Documentation/ 1281 For more details, see Documentation/locking/lockstat.rst
1424 1282
1425 This also enables lock events requir 1283 This also enables lock events required by "perf lock",
1426 subcommand of perf. 1284 subcommand of perf.
1427 If you want to use "perf lock", you 1285 If you want to use "perf lock", you also need to turn on
1428 CONFIG_EVENT_TRACING. 1286 CONFIG_EVENT_TRACING.
1429 1287
1430 CONFIG_LOCK_STAT defines "contended" 1288 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1431 (CONFIG_LOCKDEP defines "acquire" an 1289 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1432 1290
1433 config DEBUG_RT_MUTEXES 1291 config DEBUG_RT_MUTEXES
1434 bool "RT Mutex debugging, deadlock de 1292 bool "RT Mutex debugging, deadlock detection"
1435 depends on DEBUG_KERNEL && RT_MUTEXES 1293 depends on DEBUG_KERNEL && RT_MUTEXES
1436 help 1294 help
1437 This allows rt mutex semantics viola 1295 This allows rt mutex semantics violations and rt mutex related
1438 deadlocks (lockups) to be detected a 1296 deadlocks (lockups) to be detected and reported automatically.
1439 1297
1440 config DEBUG_SPINLOCK 1298 config DEBUG_SPINLOCK
1441 bool "Spinlock and rw-lock debugging: 1299 bool "Spinlock and rw-lock debugging: basic checks"
1442 depends on DEBUG_KERNEL 1300 depends on DEBUG_KERNEL
1443 select UNINLINE_SPIN_UNLOCK 1301 select UNINLINE_SPIN_UNLOCK
1444 help 1302 help
1445 Say Y here and build SMP to catch m 1303 Say Y here and build SMP to catch missing spinlock initialization
1446 and certain other kinds of spinlock 1304 and certain other kinds of spinlock errors commonly made. This is
1447 best used in conjunction with the N 1305 best used in conjunction with the NMI watchdog so that spinlock
1448 deadlocks are also debuggable. 1306 deadlocks are also debuggable.
1449 1307
1450 config DEBUG_MUTEXES 1308 config DEBUG_MUTEXES
1451 bool "Mutex debugging: basic checks" 1309 bool "Mutex debugging: basic checks"
1452 depends on DEBUG_KERNEL && !PREEMPT_R 1310 depends on DEBUG_KERNEL && !PREEMPT_RT
1453 help 1311 help
1454 This feature allows mutex semantics 1312 This feature allows mutex semantics violations to be detected and
1455 reported. 1313 reported.
1456 1314
1457 config DEBUG_WW_MUTEX_SLOWPATH 1315 config DEBUG_WW_MUTEX_SLOWPATH
1458 bool "Wait/wound mutex debugging: Slo 1316 bool "Wait/wound mutex debugging: Slowpath testing"
1459 depends on DEBUG_KERNEL && LOCK_DEBUG 1317 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1460 select DEBUG_LOCK_ALLOC 1318 select DEBUG_LOCK_ALLOC
1461 select DEBUG_SPINLOCK 1319 select DEBUG_SPINLOCK
1462 select DEBUG_MUTEXES if !PREEMPT_RT 1320 select DEBUG_MUTEXES if !PREEMPT_RT
1463 select DEBUG_RT_MUTEXES if PREEMPT_RT 1321 select DEBUG_RT_MUTEXES if PREEMPT_RT
1464 help 1322 help
1465 This feature enables slowpath testin 1323 This feature enables slowpath testing for w/w mutex users by
1466 injecting additional -EDEADLK wound/ 1324 injecting additional -EDEADLK wound/backoff cases. Together with
1467 the full mutex checks enabled with ( 1325 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1468 will test all possible w/w mutex int 1326 will test all possible w/w mutex interface abuse with the
1469 exception of simply not acquiring al 1327 exception of simply not acquiring all the required locks.
1470 Note that this feature can introduce 1328 Note that this feature can introduce significant overhead, so
1471 it really should not be enabled in a 1329 it really should not be enabled in a production or distro kernel,
1472 even a debug kernel. If you are a d 1330 even a debug kernel. If you are a driver writer, enable it. If
1473 you are a distro, do not. 1331 you are a distro, do not.
1474 1332
1475 config DEBUG_RWSEMS 1333 config DEBUG_RWSEMS
1476 bool "RW Semaphore debugging: basic c 1334 bool "RW Semaphore debugging: basic checks"
1477 depends on DEBUG_KERNEL && !PREEMPT_R !! 1335 depends on DEBUG_KERNEL
1478 help 1336 help
1479 This debugging feature allows misma 1337 This debugging feature allows mismatched rw semaphore locks
1480 and unlocks to be detected and repo 1338 and unlocks to be detected and reported.
1481 1339
1482 config DEBUG_LOCK_ALLOC 1340 config DEBUG_LOCK_ALLOC
1483 bool "Lock debugging: detect incorrec 1341 bool "Lock debugging: detect incorrect freeing of live locks"
1484 depends on DEBUG_KERNEL && LOCK_DEBUG 1342 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1485 select DEBUG_SPINLOCK 1343 select DEBUG_SPINLOCK
1486 select DEBUG_MUTEXES if !PREEMPT_RT 1344 select DEBUG_MUTEXES if !PREEMPT_RT
1487 select DEBUG_RT_MUTEXES if RT_MUTEXES 1345 select DEBUG_RT_MUTEXES if RT_MUTEXES
1488 select LOCKDEP 1346 select LOCKDEP
1489 help 1347 help
1490 This feature will check whether any 1348 This feature will check whether any held lock (spinlock, rwlock,
1491 mutex or rwsem) is incorrectly freed 1349 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1492 memory-freeing routines (kfree(), km 1350 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1493 vfree(), etc.), whether a live lock 1351 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1494 spin_lock_init()/mutex_init()/etc., 1352 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1495 held during task exit. 1353 held during task exit.
1496 1354
1497 config LOCKDEP 1355 config LOCKDEP
1498 bool 1356 bool
1499 depends on DEBUG_KERNEL && LOCK_DEBUG 1357 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1500 select STACKTRACE 1358 select STACKTRACE
1501 select KALLSYMS 1359 select KALLSYMS
1502 select KALLSYMS_ALL 1360 select KALLSYMS_ALL
1503 1361
1504 config LOCKDEP_SMALL 1362 config LOCKDEP_SMALL
1505 bool 1363 bool
1506 1364
1507 config LOCKDEP_BITS 1365 config LOCKDEP_BITS
1508 int "Bitsize for MAX_LOCKDEP_ENTRIES" 1366 int "Bitsize for MAX_LOCKDEP_ENTRIES"
1509 depends on LOCKDEP && !LOCKDEP_SMALL 1367 depends on LOCKDEP && !LOCKDEP_SMALL
1510 range 10 30 1368 range 10 30
1511 default 15 1369 default 15
1512 help 1370 help
1513 Try increasing this value if you hi 1371 Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
1514 1372
1515 config LOCKDEP_CHAINS_BITS 1373 config LOCKDEP_CHAINS_BITS
1516 int "Bitsize for MAX_LOCKDEP_CHAINS" 1374 int "Bitsize for MAX_LOCKDEP_CHAINS"
1517 depends on LOCKDEP && !LOCKDEP_SMALL 1375 depends on LOCKDEP && !LOCKDEP_SMALL
1518 range 10 30 1376 range 10 30
1519 default 16 1377 default 16
1520 help 1378 help
1521 Try increasing this value if you hi 1379 Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
1522 1380
1523 config LOCKDEP_STACK_TRACE_BITS 1381 config LOCKDEP_STACK_TRACE_BITS
1524 int "Bitsize for MAX_STACK_TRACE_ENTR 1382 int "Bitsize for MAX_STACK_TRACE_ENTRIES"
1525 depends on LOCKDEP && !LOCKDEP_SMALL 1383 depends on LOCKDEP && !LOCKDEP_SMALL
1526 range 10 30 1384 range 10 30
1527 default 19 1385 default 19
1528 help 1386 help
1529 Try increasing this value if you hi 1387 Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
1530 1388
1531 config LOCKDEP_STACK_TRACE_HASH_BITS 1389 config LOCKDEP_STACK_TRACE_HASH_BITS
1532 int "Bitsize for STACK_TRACE_HASH_SIZ 1390 int "Bitsize for STACK_TRACE_HASH_SIZE"
1533 depends on LOCKDEP && !LOCKDEP_SMALL 1391 depends on LOCKDEP && !LOCKDEP_SMALL
1534 range 10 30 1392 range 10 30
1535 default 14 1393 default 14
1536 help 1394 help
1537 Try increasing this value if you ne 1395 Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
1538 1396
1539 config LOCKDEP_CIRCULAR_QUEUE_BITS 1397 config LOCKDEP_CIRCULAR_QUEUE_BITS
1540 int "Bitsize for elements in circular 1398 int "Bitsize for elements in circular_queue struct"
1541 depends on LOCKDEP 1399 depends on LOCKDEP
1542 range 10 30 1400 range 10 30
1543 default 12 1401 default 12
1544 help 1402 help
1545 Try increasing this value if you hi 1403 Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1546 1404
1547 config DEBUG_LOCKDEP 1405 config DEBUG_LOCKDEP
1548 bool "Lock dependency engine debuggin 1406 bool "Lock dependency engine debugging"
1549 depends on DEBUG_KERNEL && LOCKDEP 1407 depends on DEBUG_KERNEL && LOCKDEP
1550 select DEBUG_IRQFLAGS 1408 select DEBUG_IRQFLAGS
1551 help 1409 help
1552 If you say Y here, the lock depende 1410 If you say Y here, the lock dependency engine will do
1553 additional runtime checks to debug 1411 additional runtime checks to debug itself, at the price
1554 of more runtime overhead. 1412 of more runtime overhead.
1555 1413
1556 config DEBUG_ATOMIC_SLEEP 1414 config DEBUG_ATOMIC_SLEEP
1557 bool "Sleep inside atomic section che 1415 bool "Sleep inside atomic section checking"
1558 select PREEMPT_COUNT 1416 select PREEMPT_COUNT
1559 depends on DEBUG_KERNEL 1417 depends on DEBUG_KERNEL
1560 depends on !ARCH_NO_PREEMPT 1418 depends on !ARCH_NO_PREEMPT
1561 help 1419 help
1562 If you say Y here, various routines 1420 If you say Y here, various routines which may sleep will become very
1563 noisy if they are called inside ato 1421 noisy if they are called inside atomic sections: when a spinlock is
1564 held, inside an rcu read side criti 1422 held, inside an rcu read side critical section, inside preempt disabled
1565 sections, inside an interrupt, etc. 1423 sections, inside an interrupt, etc...
1566 1424
1567 config DEBUG_LOCKING_API_SELFTESTS 1425 config DEBUG_LOCKING_API_SELFTESTS
1568 bool "Locking API boot-time self-test 1426 bool "Locking API boot-time self-tests"
1569 depends on DEBUG_KERNEL 1427 depends on DEBUG_KERNEL
1570 help 1428 help
1571 Say Y here if you want the kernel t 1429 Say Y here if you want the kernel to run a short self-test during
1572 bootup. The self-test checks whethe 1430 bootup. The self-test checks whether common types of locking bugs
1573 are detected by debugging mechanism 1431 are detected by debugging mechanisms or not. (if you disable
1574 lock debugging then those bugs won' 1432 lock debugging then those bugs won't be detected of course.)
1575 The following locking APIs are cove 1433 The following locking APIs are covered: spinlocks, rwlocks,
1576 mutexes and rwsems. 1434 mutexes and rwsems.
1577 1435
1578 config LOCK_TORTURE_TEST 1436 config LOCK_TORTURE_TEST
1579 tristate "torture tests for locking" 1437 tristate "torture tests for locking"
1580 depends on DEBUG_KERNEL 1438 depends on DEBUG_KERNEL
1581 select TORTURE_TEST 1439 select TORTURE_TEST
1582 help 1440 help
1583 This option provides a kernel modul 1441 This option provides a kernel module that runs torture tests
1584 on kernel locking primitives. The 1442 on kernel locking primitives. The kernel module may be built
1585 after the fact on the running kerne 1443 after the fact on the running kernel to be tested, if desired.
1586 1444
1587 Say Y here if you want kernel locki 1445 Say Y here if you want kernel locking-primitive torture tests
1588 to be built into the kernel. 1446 to be built into the kernel.
1589 Say M if you want these torture tes 1447 Say M if you want these torture tests to build as a module.
1590 Say N if you are unsure. 1448 Say N if you are unsure.
1591 1449
1592 config WW_MUTEX_SELFTEST 1450 config WW_MUTEX_SELFTEST
1593 tristate "Wait/wound mutex selftests" 1451 tristate "Wait/wound mutex selftests"
1594 help 1452 help
1595 This option provides a kernel modul 1453 This option provides a kernel module that runs tests on the
1596 on the struct ww_mutex locking API. 1454 on the struct ww_mutex locking API.
1597 1455
1598 It is recommended to enable DEBUG_W 1456 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1599 with this test harness. 1457 with this test harness.
1600 1458
1601 Say M if you want these self tests 1459 Say M if you want these self tests to build as a module.
1602 Say N if you are unsure. 1460 Say N if you are unsure.
1603 1461
1604 config SCF_TORTURE_TEST 1462 config SCF_TORTURE_TEST
1605 tristate "torture tests for smp_call_ 1463 tristate "torture tests for smp_call_function*()"
1606 depends on DEBUG_KERNEL 1464 depends on DEBUG_KERNEL
1607 select TORTURE_TEST 1465 select TORTURE_TEST
1608 help 1466 help
1609 This option provides a kernel modul 1467 This option provides a kernel module that runs torture tests
1610 on the smp_call_function() family o 1468 on the smp_call_function() family of primitives. The kernel
1611 module may be built after the fact 1469 module may be built after the fact on the running kernel to
1612 be tested, if desired. 1470 be tested, if desired.
1613 1471
1614 config CSD_LOCK_WAIT_DEBUG 1472 config CSD_LOCK_WAIT_DEBUG
1615 bool "Debugging for csd_lock_wait(), 1473 bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
1616 depends on DEBUG_KERNEL 1474 depends on DEBUG_KERNEL
1617 depends on 64BIT 1475 depends on 64BIT
1618 default n 1476 default n
1619 help 1477 help
1620 This option enables debug prints wh 1478 This option enables debug prints when CPUs are slow to respond
1621 to the smp_call_function*() IPI wra 1479 to the smp_call_function*() IPI wrappers. These debug prints
1622 include the IPI handler function cu 1480 include the IPI handler function currently executing (if any)
1623 and relevant stack traces. 1481 and relevant stack traces.
1624 1482
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 1483 endmenu # lock debugging
1635 1484
1636 config TRACE_IRQFLAGS 1485 config TRACE_IRQFLAGS
1637 depends on TRACE_IRQFLAGS_SUPPORT 1486 depends on TRACE_IRQFLAGS_SUPPORT
1638 bool 1487 bool
1639 help 1488 help
1640 Enables hooks to interrupt enabling 1489 Enables hooks to interrupt enabling and disabling for
1641 either tracing or lock debugging. 1490 either tracing or lock debugging.
1642 1491
1643 config TRACE_IRQFLAGS_NMI 1492 config TRACE_IRQFLAGS_NMI
1644 def_bool y 1493 def_bool y
1645 depends on TRACE_IRQFLAGS 1494 depends on TRACE_IRQFLAGS
1646 depends on TRACE_IRQFLAGS_NMI_SUPPORT 1495 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1647 1496
1648 config NMI_CHECK_CPU 1497 config NMI_CHECK_CPU
1649 bool "Debugging for CPUs failing to r 1498 bool "Debugging for CPUs failing to respond to backtrace requests"
1650 depends on DEBUG_KERNEL 1499 depends on DEBUG_KERNEL
1651 depends on X86 1500 depends on X86
1652 default n 1501 default n
1653 help 1502 help
1654 Enables debug prints when a CPU fai 1503 Enables debug prints when a CPU fails to respond to a given
1655 backtrace NMI. These prints provid 1504 backtrace NMI. These prints provide some reasons why a CPU
1656 might legitimately be failing to re 1505 might legitimately be failing to respond, for example, if it
1657 is offline of if ignore_nmis is set 1506 is offline of if ignore_nmis is set.
1658 1507
1659 config DEBUG_IRQFLAGS 1508 config DEBUG_IRQFLAGS
1660 bool "Debug IRQ flag manipulation" 1509 bool "Debug IRQ flag manipulation"
1661 help 1510 help
1662 Enables checks for potentially unsa 1511 Enables checks for potentially unsafe enabling or disabling of
1663 interrupts, such as calling raw_loc 1512 interrupts, such as calling raw_local_irq_restore() when interrupts
1664 are enabled. 1513 are enabled.
1665 1514
1666 config STACKTRACE 1515 config STACKTRACE
1667 bool "Stack backtrace support" 1516 bool "Stack backtrace support"
1668 depends on STACKTRACE_SUPPORT 1517 depends on STACKTRACE_SUPPORT
1669 help 1518 help
1670 This option causes the kernel to cr 1519 This option causes the kernel to create a /proc/pid/stack for
1671 every process, showing its current 1520 every process, showing its current stack trace.
1672 It is also used by various kernel d 1521 It is also used by various kernel debugging features that require
1673 stack trace generation. 1522 stack trace generation.
1674 1523
1675 config WARN_ALL_UNSEEDED_RANDOM 1524 config WARN_ALL_UNSEEDED_RANDOM
1676 bool "Warn for all uses of unseeded r 1525 bool "Warn for all uses of unseeded randomness"
1677 default n 1526 default n
1678 help 1527 help
1679 Some parts of the kernel contain bu 1528 Some parts of the kernel contain bugs relating to their use of
1680 cryptographically secure random num 1529 cryptographically secure random numbers before it's actually possible
1681 to generate those numbers securely. 1530 to generate those numbers securely. This setting ensures that these
1682 flaws don't go unnoticed, by enabli 1531 flaws don't go unnoticed, by enabling a message, should this ever
1683 occur. This will allow people with 1532 occur. This will allow people with obscure setups to know when things
1684 are going wrong, so that they might 1533 are going wrong, so that they might contact developers about fixing
1685 it. 1534 it.
1686 1535
1687 Unfortunately, on some models of so 1536 Unfortunately, on some models of some architectures getting
1688 a fully seeded CRNG is extremely di 1537 a fully seeded CRNG is extremely difficult, and so this can
1689 result in dmesg getting spammed for 1538 result in dmesg getting spammed for a surprisingly long
1690 time. This is really bad from a se 1539 time. This is really bad from a security perspective, and
1691 so architecture maintainers really 1540 so architecture maintainers really need to do what they can
1692 to get the CRNG seeded sooner after 1541 to get the CRNG seeded sooner after the system is booted.
1693 However, since users cannot do anyt 1542 However, since users cannot do anything actionable to
1694 address this, by default this optio 1543 address this, by default this option is disabled.
1695 1544
1696 Say Y here if you want to receive w 1545 Say Y here if you want to receive warnings for all uses of
1697 unseeded randomness. This will be 1546 unseeded randomness. This will be of use primarily for
1698 those developers interested in impr 1547 those developers interested in improving the security of
1699 Linux kernels running on their arch 1548 Linux kernels running on their architecture (or
1700 subarchitecture). 1549 subarchitecture).
1701 1550
1702 config DEBUG_KOBJECT 1551 config DEBUG_KOBJECT
1703 bool "kobject debugging" 1552 bool "kobject debugging"
1704 depends on DEBUG_KERNEL 1553 depends on DEBUG_KERNEL
1705 help 1554 help
1706 If you say Y here, some extra kobje 1555 If you say Y here, some extra kobject debugging messages will be sent
1707 to the syslog. 1556 to the syslog.
1708 1557
1709 config DEBUG_KOBJECT_RELEASE 1558 config DEBUG_KOBJECT_RELEASE
1710 bool "kobject release debugging" 1559 bool "kobject release debugging"
1711 depends on DEBUG_OBJECTS_TIMERS 1560 depends on DEBUG_OBJECTS_TIMERS
1712 help 1561 help
1713 kobjects are reference counted obje 1562 kobjects are reference counted objects. This means that their
1714 last reference count put is not pre 1563 last reference count put is not predictable, and the kobject can
1715 live on past the point at which a d 1564 live on past the point at which a driver decides to drop its
1716 initial reference to the kobject ga 1565 initial reference to the kobject gained on allocation. An
1717 example of this would be a struct d 1566 example of this would be a struct device which has just been
1718 unregistered. 1567 unregistered.
1719 1568
1720 However, some buggy drivers assume 1569 However, some buggy drivers assume that after such an operation,
1721 the memory backing the kobject can 1570 the memory backing the kobject can be immediately freed. This
1722 goes completely against the princip 1571 goes completely against the principles of a refcounted object.
1723 1572
1724 If you say Y here, the kernel will 1573 If you say Y here, the kernel will delay the release of kobjects
1725 on the last reference count to impr 1574 on the last reference count to improve the visibility of this
1726 kind of kobject release bug. 1575 kind of kobject release bug.
1727 1576
1728 config HAVE_DEBUG_BUGVERBOSE 1577 config HAVE_DEBUG_BUGVERBOSE
1729 bool 1578 bool
1730 1579
1731 menu "Debug kernel data structures" 1580 menu "Debug kernel data structures"
1732 1581
1733 config DEBUG_LIST 1582 config DEBUG_LIST
1734 bool "Debug linked list manipulation" 1583 bool "Debug linked list manipulation"
1735 depends on DEBUG_KERNEL !! 1584 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1736 select LIST_HARDENED <<
1737 help 1585 help
1738 Enable this to turn on extended che !! 1586 Enable this to turn on extended checks in the linked-list
1739 routines. !! 1587 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 1588
1745 If unsure, say N. 1589 If unsure, say N.
1746 1590
1747 config DEBUG_PLIST 1591 config DEBUG_PLIST
1748 bool "Debug priority linked list mani 1592 bool "Debug priority linked list manipulation"
1749 depends on DEBUG_KERNEL 1593 depends on DEBUG_KERNEL
1750 help 1594 help
1751 Enable this to turn on extended che 1595 Enable this to turn on extended checks in the priority-ordered
1752 linked-list (plist) walking routine 1596 linked-list (plist) walking routines. This checks the entire
1753 list multiple times during each man 1597 list multiple times during each manipulation.
1754 1598
1755 If unsure, say N. 1599 If unsure, say N.
1756 1600
1757 config DEBUG_SG 1601 config DEBUG_SG
1758 bool "Debug SG table operations" 1602 bool "Debug SG table operations"
1759 depends on DEBUG_KERNEL 1603 depends on DEBUG_KERNEL
1760 help 1604 help
1761 Enable this to turn on checks on sc 1605 Enable this to turn on checks on scatter-gather tables. This can
1762 help find problems with drivers tha 1606 help find problems with drivers that do not properly initialize
1763 their sg tables. 1607 their sg tables.
1764 1608
1765 If unsure, say N. 1609 If unsure, say N.
1766 1610
1767 config DEBUG_NOTIFIERS 1611 config DEBUG_NOTIFIERS
1768 bool "Debug notifier call chains" 1612 bool "Debug notifier call chains"
1769 depends on DEBUG_KERNEL 1613 depends on DEBUG_KERNEL
1770 help 1614 help
1771 Enable this to turn on sanity check 1615 Enable this to turn on sanity checking for notifier call chains.
1772 This is most useful for kernel deve 1616 This is most useful for kernel developers to make sure that
1773 modules properly unregister themsel 1617 modules properly unregister themselves from notifier chains.
1774 This is a relatively cheap check bu 1618 This is a relatively cheap check but if you care about maximum
1775 performance, say N. 1619 performance, say N.
1776 1620
1777 config DEBUG_CLOSURES !! 1621 config BUG_ON_DATA_CORRUPTION
1778 bool "Debug closures (bcache async wi !! 1622 bool "Trigger a BUG when data corruption is detected"
1779 depends on CLOSURES !! 1623 select DEBUG_LIST
1780 select DEBUG_FS !! 1624 help
1781 help !! 1625 Select this option if the kernel should BUG when it encounters
1782 Keeps all active closures in a link !! 1626 data corruption in kernel memory structures when they get checked
1783 interface to list them, which makes !! 1627 for validity.
1784 operations that get stuck. !! 1628
>> 1629 If unsure, say N.
1785 1630
1786 config DEBUG_MAPLE_TREE 1631 config DEBUG_MAPLE_TREE
1787 bool "Debug maple trees" 1632 bool "Debug maple trees"
1788 depends on DEBUG_KERNEL 1633 depends on DEBUG_KERNEL
1789 help 1634 help
1790 Enable maple tree debugging informa 1635 Enable maple tree debugging information and extra validations.
1791 1636
1792 If unsure, say N. 1637 If unsure, say N.
1793 1638
1794 endmenu 1639 endmenu
1795 1640
>> 1641 config DEBUG_CREDENTIALS
>> 1642 bool "Debug credential management"
>> 1643 depends on DEBUG_KERNEL
>> 1644 help
>> 1645 Enable this to turn on some debug checking for credential
>> 1646 management. The additional code keeps track of the number of
>> 1647 pointers from task_structs to any given cred struct, and checks to
>> 1648 see that this number never exceeds the usage count of the cred
>> 1649 struct.
>> 1650
>> 1651 Furthermore, if SELinux is enabled, this also checks that the
>> 1652 security pointer in the cred struct is never seen to be invalid.
>> 1653
>> 1654 If unsure, say N.
>> 1655
1796 source "kernel/rcu/Kconfig.debug" 1656 source "kernel/rcu/Kconfig.debug"
1797 1657
1798 config DEBUG_WQ_FORCE_RR_CPU 1658 config DEBUG_WQ_FORCE_RR_CPU
1799 bool "Force round-robin CPU selection 1659 bool "Force round-robin CPU selection for unbound work items"
1800 depends on DEBUG_KERNEL 1660 depends on DEBUG_KERNEL
1801 default n 1661 default n
1802 help 1662 help
1803 Workqueue used to implicitly guaran 1663 Workqueue used to implicitly guarantee that work items queued
1804 without explicit CPU specified are 1664 without explicit CPU specified are put on the local CPU. This
1805 guarantee is no longer true and whi 1665 guarantee is no longer true and while local CPU is still
1806 preferred work items may be put on 1666 preferred work items may be put on foreign CPUs. Kernel
1807 parameter "workqueue.debug_force_rr 1667 parameter "workqueue.debug_force_rr_cpu" is added to force
1808 round-robin CPU selection to flush 1668 round-robin CPU selection to flush out usages which depend on the
1809 now broken guarantee. This config 1669 now broken guarantee. This config option enables the debug
1810 feature by default. When enabled, 1670 feature by default. When enabled, memory and cache locality will
1811 be impacted. 1671 be impacted.
1812 1672
1813 config CPU_HOTPLUG_STATE_CONTROL 1673 config CPU_HOTPLUG_STATE_CONTROL
1814 bool "Enable CPU hotplug state contro 1674 bool "Enable CPU hotplug state control"
1815 depends on DEBUG_KERNEL 1675 depends on DEBUG_KERNEL
1816 depends on HOTPLUG_CPU 1676 depends on HOTPLUG_CPU
1817 default n 1677 default n
1818 help 1678 help
1819 Allows to write steps between "offl 1679 Allows to write steps between "offline" and "online" to the CPUs
1820 sysfs target file so states can be 1680 sysfs target file so states can be stepped granular. This is a debug
1821 option for now as the hotplug machi 1681 option for now as the hotplug machinery cannot be stopped and
1822 restarted at arbitrary points yet. 1682 restarted at arbitrary points yet.
1823 1683
1824 Say N if your are unsure. 1684 Say N if your are unsure.
1825 1685
1826 config LATENCYTOP 1686 config LATENCYTOP
1827 bool "Latency measuring infrastructur 1687 bool "Latency measuring infrastructure"
1828 depends on DEBUG_KERNEL 1688 depends on DEBUG_KERNEL
1829 depends on STACKTRACE_SUPPORT 1689 depends on STACKTRACE_SUPPORT
1830 depends on PROC_FS 1690 depends on PROC_FS
1831 depends on FRAME_POINTER || MIPS || P 1691 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
1832 select KALLSYMS 1692 select KALLSYMS
1833 select KALLSYMS_ALL 1693 select KALLSYMS_ALL
1834 select STACKTRACE 1694 select STACKTRACE
1835 select SCHEDSTATS 1695 select SCHEDSTATS
1836 help 1696 help
1837 Enable this option if you want to u 1697 Enable this option if you want to use the LatencyTOP tool
1838 to find out which userspace is bloc 1698 to find out which userspace is blocking on what kernel operations.
1839 1699
1840 config DEBUG_CGROUP_REF 1700 config DEBUG_CGROUP_REF
1841 bool "Disable inlining of cgroup css 1701 bool "Disable inlining of cgroup css reference count functions"
1842 depends on DEBUG_KERNEL 1702 depends on DEBUG_KERNEL
1843 depends on CGROUPS 1703 depends on CGROUPS
1844 depends on KPROBES 1704 depends on KPROBES
1845 default n 1705 default n
1846 help 1706 help
1847 Force cgroup css reference count fu 1707 Force cgroup css reference count functions to not be inlined so
1848 that they can be kprobed for debugg 1708 that they can be kprobed for debugging.
1849 1709
1850 source "kernel/trace/Kconfig" 1710 source "kernel/trace/Kconfig"
1851 1711
1852 config PROVIDE_OHCI1394_DMA_INIT 1712 config PROVIDE_OHCI1394_DMA_INIT
1853 bool "Remote debugging over FireWire 1713 bool "Remote debugging over FireWire early on boot"
1854 depends on PCI && X86 1714 depends on PCI && X86
1855 help 1715 help
1856 If you want to debug problems which 1716 If you want to debug problems which hang or crash the kernel early
1857 on boot and the crashing machine ha 1717 on boot and the crashing machine has a FireWire port, you can use
1858 this feature to remotely access the 1718 this feature to remotely access the memory of the crashed machine
1859 over FireWire. This employs remote 1719 over FireWire. This employs remote DMA as part of the OHCI1394
1860 specification which is now the stan 1720 specification which is now the standard for FireWire controllers.
1861 1721
1862 With remote DMA, you can monitor th 1722 With remote DMA, you can monitor the printk buffer remotely using
1863 firescope and access all memory bel 1723 firescope and access all memory below 4GB using fireproxy from gdb.
1864 Even controlling a kernel debugger 1724 Even controlling a kernel debugger is possible using remote DMA.
1865 1725
1866 Usage: 1726 Usage:
1867 1727
1868 If ohci1394_dma=early is used as bo 1728 If ohci1394_dma=early is used as boot parameter, it will initialize
1869 all OHCI1394 controllers which are 1729 all OHCI1394 controllers which are found in the PCI config space.
1870 1730
1871 As all changes to the FireWire bus 1731 As all changes to the FireWire bus such as enabling and disabling
1872 devices cause a bus reset and there 1732 devices cause a bus reset and thereby disable remote DMA for all
1873 devices, be sure to have the cable 1733 devices, be sure to have the cable plugged and FireWire enabled on
1874 the debugging host before booting t 1734 the debugging host before booting the debug target for debugging.
1875 1735
1876 This code (~1k) is freed after boot 1736 This code (~1k) is freed after boot. By then, the firewire stack
1877 in charge of the OHCI-1394 controll 1737 in charge of the OHCI-1394 controllers should be used instead.
1878 1738
1879 See Documentation/core-api/debuggin 1739 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1880 1740
1881 source "samples/Kconfig" 1741 source "samples/Kconfig"
1882 1742
1883 config ARCH_HAS_DEVMEM_IS_ALLOWED 1743 config ARCH_HAS_DEVMEM_IS_ALLOWED
1884 bool 1744 bool
1885 1745
1886 config STRICT_DEVMEM 1746 config STRICT_DEVMEM
1887 bool "Filter access to /dev/mem" 1747 bool "Filter access to /dev/mem"
1888 depends on MMU && DEVMEM 1748 depends on MMU && DEVMEM
1889 depends on ARCH_HAS_DEVMEM_IS_ALLOWED 1749 depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
1890 default y if PPC || X86 || ARM64 1750 default y if PPC || X86 || ARM64
1891 help 1751 help
1892 If this option is disabled, you all 1752 If this option is disabled, you allow userspace (root) access to all
1893 of memory, including kernel and use 1753 of memory, including kernel and userspace memory. Accidental
1894 access to this is obviously disastr 1754 access to this is obviously disastrous, but specific access can
1895 be used by people debugging the ker 1755 be used by people debugging the kernel. Note that with PAT support
1896 enabled, even in this case there ar 1756 enabled, even in this case there are restrictions on /dev/mem
1897 use due to the cache aliasing requi 1757 use due to the cache aliasing requirements.
1898 1758
1899 If this option is switched on, and 1759 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1900 file only allows userspace access t 1760 file only allows userspace access to PCI space and the BIOS code and
1901 data regions. This is sufficient f 1761 data regions. This is sufficient for dosemu and X and all common
1902 users of /dev/mem. 1762 users of /dev/mem.
1903 1763
1904 If in doubt, say Y. 1764 If in doubt, say Y.
1905 1765
1906 config IO_STRICT_DEVMEM 1766 config IO_STRICT_DEVMEM
1907 bool "Filter I/O access to /dev/mem" 1767 bool "Filter I/O access to /dev/mem"
1908 depends on STRICT_DEVMEM 1768 depends on STRICT_DEVMEM
1909 help 1769 help
1910 If this option is disabled, you all 1770 If this option is disabled, you allow userspace (root) access to all
1911 io-memory regardless of whether a d 1771 io-memory regardless of whether a driver is actively using that
1912 range. Accidental access to this i 1772 range. Accidental access to this is obviously disastrous, but
1913 specific access can be used by peop 1773 specific access can be used by people debugging kernel drivers.
1914 1774
1915 If this option is switched on, the 1775 If this option is switched on, the /dev/mem file only allows
1916 userspace access to *idle* io-memor 1776 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1917 may break traditional users of /dev 1777 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1918 if the driver using a given range c 1778 if the driver using a given range cannot be disabled.
1919 1779
1920 If in doubt, say Y. 1780 If in doubt, say Y.
1921 1781
1922 menu "$(SRCARCH) Debugging" 1782 menu "$(SRCARCH) Debugging"
1923 1783
1924 source "arch/$(SRCARCH)/Kconfig.debug" 1784 source "arch/$(SRCARCH)/Kconfig.debug"
1925 1785
1926 endmenu 1786 endmenu
1927 1787
1928 menu "Kernel Testing and Coverage" 1788 menu "Kernel Testing and Coverage"
1929 1789
1930 source "lib/kunit/Kconfig" 1790 source "lib/kunit/Kconfig"
1931 1791
1932 config NOTIFIER_ERROR_INJECTION 1792 config NOTIFIER_ERROR_INJECTION
1933 tristate "Notifier error injection" 1793 tristate "Notifier error injection"
1934 depends on DEBUG_KERNEL 1794 depends on DEBUG_KERNEL
1935 select DEBUG_FS 1795 select DEBUG_FS
1936 help 1796 help
1937 This option provides the ability to 1797 This option provides the ability to inject artificial errors to
1938 specified notifier chain callbacks. 1798 specified notifier chain callbacks. It is useful to test the error
1939 handling of notifier call chain fai 1799 handling of notifier call chain failures.
1940 1800
1941 Say N if unsure. 1801 Say N if unsure.
1942 1802
1943 config PM_NOTIFIER_ERROR_INJECT 1803 config PM_NOTIFIER_ERROR_INJECT
1944 tristate "PM notifier error injection 1804 tristate "PM notifier error injection module"
1945 depends on PM && NOTIFIER_ERROR_INJEC 1805 depends on PM && NOTIFIER_ERROR_INJECTION
1946 default m if PM_DEBUG 1806 default m if PM_DEBUG
1947 help 1807 help
1948 This option provides the ability to 1808 This option provides the ability to inject artificial errors to
1949 PM notifier chain callbacks. It is 1809 PM notifier chain callbacks. It is controlled through debugfs
1950 interface /sys/kernel/debug/notifie 1810 interface /sys/kernel/debug/notifier-error-inject/pm
1951 1811
1952 If the notifier call chain should b 1812 If the notifier call chain should be failed with some events
1953 notified, write the error code to " 1813 notified, write the error code to "actions/<notifier event>/error".
1954 1814
1955 Example: Inject PM suspend error (- 1815 Example: Inject PM suspend error (-12 = -ENOMEM)
1956 1816
1957 # cd /sys/kernel/debug/notifier-err 1817 # cd /sys/kernel/debug/notifier-error-inject/pm/
1958 # echo -12 > actions/PM_SUSPEND_PRE 1818 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1959 # echo mem > /sys/power/state 1819 # echo mem > /sys/power/state
1960 bash: echo: write error: Cannot all 1820 bash: echo: write error: Cannot allocate memory
1961 1821
1962 To compile this code as a module, c 1822 To compile this code as a module, choose M here: the module will
1963 be called pm-notifier-error-inject. 1823 be called pm-notifier-error-inject.
1964 1824
1965 If unsure, say N. 1825 If unsure, say N.
1966 1826
1967 config OF_RECONFIG_NOTIFIER_ERROR_INJECT 1827 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1968 tristate "OF reconfig notifier error 1828 tristate "OF reconfig notifier error injection module"
1969 depends on OF_DYNAMIC && NOTIFIER_ERR 1829 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1970 help 1830 help
1971 This option provides the ability to 1831 This option provides the ability to inject artificial errors to
1972 OF reconfig notifier chain callback 1832 OF reconfig notifier chain callbacks. It is controlled
1973 through debugfs interface under 1833 through debugfs interface under
1974 /sys/kernel/debug/notifier-error-in 1834 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1975 1835
1976 If the notifier call chain should b 1836 If the notifier call chain should be failed with some events
1977 notified, write the error code to " 1837 notified, write the error code to "actions/<notifier event>/error".
1978 1838
1979 To compile this code as a module, c 1839 To compile this code as a module, choose M here: the module will
1980 be called of-reconfig-notifier-erro 1840 be called of-reconfig-notifier-error-inject.
1981 1841
1982 If unsure, say N. 1842 If unsure, say N.
1983 1843
1984 config NETDEV_NOTIFIER_ERROR_INJECT 1844 config NETDEV_NOTIFIER_ERROR_INJECT
1985 tristate "Netdev notifier error injec 1845 tristate "Netdev notifier error injection module"
1986 depends on NET && NOTIFIER_ERROR_INJE 1846 depends on NET && NOTIFIER_ERROR_INJECTION
1987 help 1847 help
1988 This option provides the ability to 1848 This option provides the ability to inject artificial errors to
1989 netdevice notifier chain callbacks. 1849 netdevice notifier chain callbacks. It is controlled through debugfs
1990 interface /sys/kernel/debug/notifie 1850 interface /sys/kernel/debug/notifier-error-inject/netdev
1991 1851
1992 If the notifier call chain should b 1852 If the notifier call chain should be failed with some events
1993 notified, write the error code to " 1853 notified, write the error code to "actions/<notifier event>/error".
1994 1854
1995 Example: Inject netdevice mtu chang 1855 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1996 1856
1997 # cd /sys/kernel/debug/notifier-err 1857 # cd /sys/kernel/debug/notifier-error-inject/netdev
1998 # echo -22 > actions/NETDEV_CHANGEM 1858 # echo -22 > actions/NETDEV_CHANGEMTU/error
1999 # ip link set eth0 mtu 1024 1859 # ip link set eth0 mtu 1024
2000 RTNETLINK answers: Invalid argument 1860 RTNETLINK answers: Invalid argument
2001 1861
2002 To compile this code as a module, c 1862 To compile this code as a module, choose M here: the module will
2003 be called netdev-notifier-error-inj 1863 be called netdev-notifier-error-inject.
2004 1864
2005 If unsure, say N. 1865 If unsure, say N.
2006 1866
2007 config FUNCTION_ERROR_INJECTION 1867 config FUNCTION_ERROR_INJECTION
2008 bool "Fault-injections of functions" 1868 bool "Fault-injections of functions"
2009 depends on HAVE_FUNCTION_ERROR_INJECT 1869 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
2010 help 1870 help
2011 Add fault injections into various f 1871 Add fault injections into various functions that are annotated with
2012 ALLOW_ERROR_INJECTION() in the kern 1872 ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
2013 value of these functions. This is u 1873 value of these functions. This is useful to test error paths of code.
2014 1874
2015 If unsure, say N 1875 If unsure, say N
2016 1876
2017 config FAULT_INJECTION 1877 config FAULT_INJECTION
2018 bool "Fault-injection framework" 1878 bool "Fault-injection framework"
2019 depends on DEBUG_KERNEL 1879 depends on DEBUG_KERNEL
2020 help 1880 help
2021 Provide fault-injection framework. 1881 Provide fault-injection framework.
2022 For more details, see Documentation 1882 For more details, see Documentation/fault-injection/.
2023 1883
2024 config FAILSLAB 1884 config FAILSLAB
2025 bool "Fault-injection capability for 1885 bool "Fault-injection capability for kmalloc"
2026 depends on FAULT_INJECTION 1886 depends on FAULT_INJECTION
>> 1887 depends on SLAB || SLUB
2027 help 1888 help
2028 Provide fault-injection capability 1889 Provide fault-injection capability for kmalloc.
2029 1890
2030 config FAIL_PAGE_ALLOC 1891 config FAIL_PAGE_ALLOC
2031 bool "Fault-injection capability for 1892 bool "Fault-injection capability for alloc_pages()"
2032 depends on FAULT_INJECTION 1893 depends on FAULT_INJECTION
2033 help 1894 help
2034 Provide fault-injection capability 1895 Provide fault-injection capability for alloc_pages().
2035 1896
2036 config FAULT_INJECTION_USERCOPY 1897 config FAULT_INJECTION_USERCOPY
2037 bool "Fault injection capability for 1898 bool "Fault injection capability for usercopy functions"
2038 depends on FAULT_INJECTION 1899 depends on FAULT_INJECTION
2039 help 1900 help
2040 Provides fault-injection capability 1901 Provides fault-injection capability to inject failures
2041 in usercopy functions (copy_from_us 1902 in usercopy functions (copy_from_user(), get_user(), ...).
2042 1903
2043 config FAIL_MAKE_REQUEST 1904 config FAIL_MAKE_REQUEST
2044 bool "Fault-injection capability for 1905 bool "Fault-injection capability for disk IO"
2045 depends on FAULT_INJECTION && BLOCK 1906 depends on FAULT_INJECTION && BLOCK
2046 help 1907 help
2047 Provide fault-injection capability 1908 Provide fault-injection capability for disk IO.
2048 1909
2049 config FAIL_IO_TIMEOUT 1910 config FAIL_IO_TIMEOUT
2050 bool "Fault-injection capability for 1911 bool "Fault-injection capability for faking disk interrupts"
2051 depends on FAULT_INJECTION && BLOCK 1912 depends on FAULT_INJECTION && BLOCK
2052 help 1913 help
2053 Provide fault-injection capability 1914 Provide fault-injection capability on end IO handling. This
2054 will make the block layer "forget" 1915 will make the block layer "forget" an interrupt as configured,
2055 thus exercising the error handling. 1916 thus exercising the error handling.
2056 1917
2057 Only works with drivers that use th 1918 Only works with drivers that use the generic timeout handling,
2058 for others it won't do anything. 1919 for others it won't do anything.
2059 1920
2060 config FAIL_FUTEX 1921 config FAIL_FUTEX
2061 bool "Fault-injection capability for 1922 bool "Fault-injection capability for futexes"
2062 select DEBUG_FS 1923 select DEBUG_FS
2063 depends on FAULT_INJECTION && FUTEX 1924 depends on FAULT_INJECTION && FUTEX
2064 help 1925 help
2065 Provide fault-injection capability 1926 Provide fault-injection capability for futexes.
2066 1927
2067 config FAULT_INJECTION_DEBUG_FS 1928 config FAULT_INJECTION_DEBUG_FS
2068 bool "Debugfs entries for fault-injec 1929 bool "Debugfs entries for fault-injection capabilities"
2069 depends on FAULT_INJECTION && SYSFS & 1930 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
2070 help 1931 help
2071 Enable configuration of fault-injec 1932 Enable configuration of fault-injection capabilities via debugfs.
2072 1933
2073 config FAIL_FUNCTION 1934 config FAIL_FUNCTION
2074 bool "Fault-injection capability for 1935 bool "Fault-injection capability for functions"
2075 depends on FAULT_INJECTION_DEBUG_FS & 1936 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
2076 help 1937 help
2077 Provide function-based fault-inject 1938 Provide function-based fault-injection capability.
2078 This will allow you to override a s 1939 This will allow you to override a specific function with a return
2079 with given return value. As a resul 1940 with given return value. As a result, function caller will see
2080 an error value and have to handle i 1941 an error value and have to handle it. This is useful to test the
2081 error handling in various subsystem 1942 error handling in various subsystems.
2082 1943
2083 config FAIL_MMC_REQUEST 1944 config FAIL_MMC_REQUEST
2084 bool "Fault-injection capability for 1945 bool "Fault-injection capability for MMC IO"
2085 depends on FAULT_INJECTION_DEBUG_FS & 1946 depends on FAULT_INJECTION_DEBUG_FS && MMC
2086 help 1947 help
2087 Provide fault-injection capability 1948 Provide fault-injection capability for MMC IO.
2088 This will make the mmc core return 1949 This will make the mmc core return data errors. This is
2089 useful to test the error handling i 1950 useful to test the error handling in the mmc block device
2090 and to test how the mmc host driver 1951 and to test how the mmc host driver handles retries from
2091 the block device. 1952 the block device.
2092 1953
2093 config FAIL_SUNRPC 1954 config FAIL_SUNRPC
2094 bool "Fault-injection capability for 1955 bool "Fault-injection capability for SunRPC"
2095 depends on FAULT_INJECTION_DEBUG_FS & 1956 depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
2096 help 1957 help
2097 Provide fault-injection capability 1958 Provide fault-injection capability for SunRPC and
2098 its consumers. 1959 its consumers.
2099 1960
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 1961 config FAULT_INJECTION_STACKTRACE_FILTER
2112 bool "stacktrace filter for fault-inj 1962 bool "stacktrace filter for fault-injection capabilities"
2113 depends on FAULT_INJECTION !! 1963 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
2114 depends on (FAULT_INJECTION_DEBUG_FS <<
2115 select STACKTRACE 1964 select STACKTRACE
2116 depends on FRAME_POINTER || MIPS || P 1965 depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
2117 help 1966 help
2118 Provide stacktrace filter for fault 1967 Provide stacktrace filter for fault-injection capabilities
2119 1968
2120 config ARCH_HAS_KCOV 1969 config ARCH_HAS_KCOV
2121 bool 1970 bool
2122 help 1971 help
2123 An architecture should select this 1972 An architecture should select this when it can successfully
2124 build and run with CONFIG_KCOV. Thi 1973 build and run with CONFIG_KCOV. This typically requires
2125 disabling instrumentation for some 1974 disabling instrumentation for some early boot code.
2126 1975
2127 config CC_HAS_SANCOV_TRACE_PC 1976 config CC_HAS_SANCOV_TRACE_PC
2128 def_bool $(cc-option,-fsanitize-cover 1977 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2129 1978
2130 1979
2131 config KCOV 1980 config KCOV
2132 bool "Code coverage for fuzzing" 1981 bool "Code coverage for fuzzing"
2133 depends on ARCH_HAS_KCOV 1982 depends on ARCH_HAS_KCOV
2134 depends on CC_HAS_SANCOV_TRACE_PC || 1983 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
2135 depends on !ARCH_WANTS_NO_INSTR || HA 1984 depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
2136 GCC_VERSION >= 120000 || C !! 1985 GCC_VERSION >= 120000 || CLANG_VERSION >= 130000
2137 select DEBUG_FS 1986 select DEBUG_FS
2138 select GCC_PLUGIN_SANCOV if !CC_HAS_S 1987 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
2139 select OBJTOOL if HAVE_NOINSTR_HACK 1988 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 2035 config TEST_DHRY
2183 tristate "Dhrystone benchmark test" 2036 tristate "Dhrystone benchmark test"
2184 help 2037 help
2185 Enable this to include the Dhryston 2038 Enable this to include the Dhrystone 2.1 benchmark. This test
2186 calculates the number of Dhrystones 2039 calculates the number of Dhrystones per second, and the number of
2187 DMIPS (Dhrystone MIPS) obtained whe 2040 DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
2188 by 1757 (the number of Dhrystones p 2041 by 1757 (the number of Dhrystones per second obtained on the VAX
2189 11/780, nominally a 1 MIPS machine) 2042 11/780, nominally a 1 MIPS machine).
2190 2043
2191 To run the benchmark, it needs to b 2044 To run the benchmark, it needs to be enabled explicitly, either from
2192 the kernel command line (when built 2045 the kernel command line (when built-in), or from userspace (when
2193 built-in or modular). !! 2046 built-in or modular.
2194 2047
2195 Run once during kernel boot: 2048 Run once during kernel boot:
2196 2049
2197 test_dhry.run 2050 test_dhry.run
2198 2051
2199 Set number of iterations from kerne 2052 Set number of iterations from kernel command line:
2200 2053
2201 test_dhry.iterations=<n> 2054 test_dhry.iterations=<n>
2202 2055
2203 Set number of iterations from users 2056 Set number of iterations from userspace:
2204 2057
2205 echo <n> > /sys/module/test_dhr 2058 echo <n> > /sys/module/test_dhry/parameters/iterations
2206 2059
2207 Trigger manual run from userspace: 2060 Trigger manual run from userspace:
2208 2061
2209 echo y > /sys/module/test_dhry/ 2062 echo y > /sys/module/test_dhry/parameters/run
2210 2063
2211 If the number of iterations is <= 0 2064 If the number of iterations is <= 0, the test will devise a suitable
2212 number of iterations (test runs for 2065 number of iterations (test runs for at least 2s) automatically.
2213 This process takes ca. 4s. 2066 This process takes ca. 4s.
2214 2067
2215 If unsure, say N. 2068 If unsure, say N.
2216 2069
2217 config LKDTM 2070 config LKDTM
2218 tristate "Linux Kernel Dump Test Tool 2071 tristate "Linux Kernel Dump Test Tool Module"
2219 depends on DEBUG_FS 2072 depends on DEBUG_FS
2220 help 2073 help
2221 This module enables testing of the di 2074 This module enables testing of the different dumping mechanisms by
2222 inducing system failures at predefine 2075 inducing system failures at predefined crash points.
2223 If you don't need it: say N 2076 If you don't need it: say N
2224 Choose M here to compile this code as 2077 Choose M here to compile this code as a module. The module will be
2225 called lkdtm. 2078 called lkdtm.
2226 2079
2227 Documentation on how to use the modul 2080 Documentation on how to use the module can be found in
2228 Documentation/fault-injection/provoke 2081 Documentation/fault-injection/provoke-crashes.rst
2229 2082
2230 config CPUMASK_KUNIT_TEST 2083 config CPUMASK_KUNIT_TEST
2231 tristate "KUnit test for cpumask" if 2084 tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
2232 depends on KUNIT 2085 depends on KUNIT
2233 default KUNIT_ALL_TESTS 2086 default KUNIT_ALL_TESTS
2234 help 2087 help
2235 Enable to turn on cpumask tests, ru 2088 Enable to turn on cpumask tests, running at boot or module load time.
2236 2089
2237 For more information on KUnit and u 2090 For more information on KUnit and unit tests in general, please refer
2238 to the KUnit documentation in Docum 2091 to the KUnit documentation in Documentation/dev-tools/kunit/.
2239 2092
2240 If unsure, say N. 2093 If unsure, say N.
2241 2094
2242 config TEST_LIST_SORT 2095 config TEST_LIST_SORT
2243 tristate "Linked list sorting test" i 2096 tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
2244 depends on KUNIT 2097 depends on KUNIT
2245 default KUNIT_ALL_TESTS 2098 default KUNIT_ALL_TESTS
2246 help 2099 help
2247 Enable this to turn on 'list_sort() 2100 Enable this to turn on 'list_sort()' function test. This test is
2248 executed only once during system bo 2101 executed only once during system boot (so affects only boot time),
2249 or at module load time. 2102 or at module load time.
2250 2103
2251 If unsure, say N. 2104 If unsure, say N.
2252 2105
2253 config TEST_MIN_HEAP 2106 config TEST_MIN_HEAP
2254 tristate "Min heap test" 2107 tristate "Min heap test"
2255 depends on DEBUG_KERNEL || m 2108 depends on DEBUG_KERNEL || m
2256 help 2109 help
2257 Enable this to turn on min heap fun 2110 Enable this to turn on min heap function tests. This test is
2258 executed only once during system bo 2111 executed only once during system boot (so affects only boot time),
2259 or at module load time. 2112 or at module load time.
2260 2113
2261 If unsure, say N. 2114 If unsure, say N.
2262 2115
2263 config TEST_SORT 2116 config TEST_SORT
2264 tristate "Array-based sort test" if ! 2117 tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2265 depends on KUNIT 2118 depends on KUNIT
2266 default KUNIT_ALL_TESTS 2119 default KUNIT_ALL_TESTS
2267 help 2120 help
2268 This option enables the self-test f 2121 This option enables the self-test function of 'sort()' at boot,
2269 or at module load time. 2122 or at module load time.
2270 2123
2271 If unsure, say N. 2124 If unsure, say N.
2272 2125
2273 config TEST_DIV64 2126 config TEST_DIV64
2274 tristate "64bit/32bit division and mo 2127 tristate "64bit/32bit division and modulo test"
2275 depends on DEBUG_KERNEL || m 2128 depends on DEBUG_KERNEL || m
2276 help 2129 help
2277 Enable this to turn on 'do_div()' f 2130 Enable this to turn on 'do_div()' function test. This test is
2278 executed only once during system bo 2131 executed only once during system boot (so affects only boot time),
2279 or at module load time. 2132 or at module load time.
2280 2133
2281 If unsure, say N. 2134 If unsure, say N.
2282 2135
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 2136 config KPROBES_SANITY_TEST
2296 tristate "Kprobes sanity tests" if !K 2137 tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
2297 depends on DEBUG_KERNEL 2138 depends on DEBUG_KERNEL
2298 depends on KPROBES 2139 depends on KPROBES
2299 depends on KUNIT 2140 depends on KUNIT
2300 select STACKTRACE if ARCH_CORRECT_STA 2141 select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
2301 default KUNIT_ALL_TESTS 2142 default KUNIT_ALL_TESTS
2302 help 2143 help
2303 This option provides for testing ba 2144 This option provides for testing basic kprobes functionality on
2304 boot. Samples of kprobe and kretpro 2145 boot. Samples of kprobe and kretprobe are inserted and
2305 verified for functionality. 2146 verified for functionality.
2306 2147
2307 Say N if you are unsure. 2148 Say N if you are unsure.
2308 2149
2309 config FPROBE_SANITY_TEST 2150 config FPROBE_SANITY_TEST
2310 bool "Self test for fprobe" 2151 bool "Self test for fprobe"
2311 depends on DEBUG_KERNEL 2152 depends on DEBUG_KERNEL
2312 depends on FPROBE 2153 depends on FPROBE
2313 depends on KUNIT=y 2154 depends on KUNIT=y
2314 help 2155 help
2315 This option will enable testing the 2156 This option will enable testing the fprobe when the system boot.
2316 A series of tests are made to verif 2157 A series of tests are made to verify that the fprobe is functioning
2317 properly. 2158 properly.
2318 2159
2319 Say N if you are unsure. 2160 Say N if you are unsure.
2320 2161
2321 config BACKTRACE_SELF_TEST 2162 config BACKTRACE_SELF_TEST
2322 tristate "Self test for the backtrace 2163 tristate "Self test for the backtrace code"
2323 depends on DEBUG_KERNEL 2164 depends on DEBUG_KERNEL
2324 help 2165 help
2325 This option provides a kernel modul 2166 This option provides a kernel module that can be used to test
2326 the kernel stack backtrace code. Th 2167 the kernel stack backtrace code. This option is not useful
2327 for distributions or general kernel 2168 for distributions or general kernels, but only for kernel
2328 developers working on architecture 2169 developers working on architecture code.
2329 2170
2330 Note that if you want to also test 2171 Note that if you want to also test saved backtraces, you will
2331 have to enable STACKTRACE as well. 2172 have to enable STACKTRACE as well.
2332 2173
2333 Say N if you are unsure. 2174 Say N if you are unsure.
2334 2175
2335 config TEST_REF_TRACKER 2176 config TEST_REF_TRACKER
2336 tristate "Self test for reference tra 2177 tristate "Self test for reference tracker"
2337 depends on DEBUG_KERNEL && STACKTRACE 2178 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
2338 select REF_TRACKER 2179 select REF_TRACKER
2339 help 2180 help
2340 This option provides a kernel modul 2181 This option provides a kernel module performing tests
2341 using reference tracker infrastruct 2182 using reference tracker infrastructure.
2342 2183
2343 Say N if you are unsure. 2184 Say N if you are unsure.
2344 2185
2345 config RBTREE_TEST 2186 config RBTREE_TEST
2346 tristate "Red-Black tree test" 2187 tristate "Red-Black tree test"
2347 depends on DEBUG_KERNEL 2188 depends on DEBUG_KERNEL
2348 help 2189 help
2349 A benchmark measuring the performan 2190 A benchmark measuring the performance of the rbtree library.
2350 Also includes rbtree invariant chec 2191 Also includes rbtree invariant checks.
2351 2192
2352 config REED_SOLOMON_TEST 2193 config REED_SOLOMON_TEST
2353 tristate "Reed-Solomon library test" 2194 tristate "Reed-Solomon library test"
2354 depends on DEBUG_KERNEL || m 2195 depends on DEBUG_KERNEL || m
2355 select REED_SOLOMON 2196 select REED_SOLOMON
2356 select REED_SOLOMON_ENC16 2197 select REED_SOLOMON_ENC16
2357 select REED_SOLOMON_DEC16 2198 select REED_SOLOMON_DEC16
2358 help 2199 help
2359 This option enables the self-test f 2200 This option enables the self-test function of rslib at boot,
2360 or at module load time. 2201 or at module load time.
2361 2202
2362 If unsure, say N. 2203 If unsure, say N.
2363 2204
2364 config INTERVAL_TREE_TEST 2205 config INTERVAL_TREE_TEST
2365 tristate "Interval tree test" 2206 tristate "Interval tree test"
2366 depends on DEBUG_KERNEL 2207 depends on DEBUG_KERNEL
2367 select INTERVAL_TREE 2208 select INTERVAL_TREE
2368 help 2209 help
2369 A benchmark measuring the performan 2210 A benchmark measuring the performance of the interval tree library
2370 2211
2371 config PERCPU_TEST 2212 config PERCPU_TEST
2372 tristate "Per cpu operations test" 2213 tristate "Per cpu operations test"
2373 depends on m && DEBUG_KERNEL 2214 depends on m && DEBUG_KERNEL
2374 help 2215 help
2375 Enable this option to build test mo 2216 Enable this option to build test module which validates per-cpu
2376 operations. 2217 operations.
2377 2218
2378 If unsure, say N. 2219 If unsure, say N.
2379 2220
2380 config ATOMIC64_SELFTEST 2221 config ATOMIC64_SELFTEST
2381 tristate "Perform an atomic64_t self- 2222 tristate "Perform an atomic64_t self-test"
2382 help 2223 help
2383 Enable this option to test the atom 2224 Enable this option to test the atomic64_t functions at boot or
2384 at module load time. 2225 at module load time.
2385 2226
2386 If unsure, say N. 2227 If unsure, say N.
2387 2228
2388 config ASYNC_RAID6_TEST 2229 config ASYNC_RAID6_TEST
2389 tristate "Self test for hardware acce 2230 tristate "Self test for hardware accelerated raid6 recovery"
2390 depends on ASYNC_RAID6_RECOV 2231 depends on ASYNC_RAID6_RECOV
2391 select ASYNC_MEMCPY 2232 select ASYNC_MEMCPY
2392 help 2233 help
2393 This is a one-shot self test that p 2234 This is a one-shot self test that permutes through the
2394 recovery of all the possible two di 2235 recovery of all the possible two disk failure scenarios for a
2395 N-disk array. Recovery is performe 2236 N-disk array. Recovery is performed with the asynchronous
2396 raid6 recovery routines, and will o 2237 raid6 recovery routines, and will optionally use an offload
2397 engine if one is available. 2238 engine if one is available.
2398 2239
2399 If unsure, say N. 2240 If unsure, say N.
2400 2241
2401 config TEST_HEXDUMP 2242 config TEST_HEXDUMP
2402 tristate "Test functions located in t 2243 tristate "Test functions located in the hexdump module at runtime"
2403 2244
2404 config STRING_KUNIT_TEST !! 2245 config STRING_SELFTEST
2405 tristate "KUnit test string functions !! 2246 tristate "Test string functions at runtime"
2406 depends on KUNIT <<
2407 default KUNIT_ALL_TESTS <<
2408 2247
2409 config STRING_HELPERS_KUNIT_TEST !! 2248 config TEST_STRING_HELPERS
2410 tristate "KUnit test string helpers a !! 2249 tristate "Test functions located in the string_helpers module at runtime"
2411 depends on KUNIT <<
2412 default KUNIT_ALL_TESTS <<
2413 2250
2414 config TEST_KSTRTOX 2251 config TEST_KSTRTOX
2415 tristate "Test kstrto*() family of fu 2252 tristate "Test kstrto*() family of functions at runtime"
2416 2253
2417 config TEST_PRINTF 2254 config TEST_PRINTF
2418 tristate "Test printf() family of fun 2255 tristate "Test printf() family of functions at runtime"
2419 2256
2420 config TEST_SCANF 2257 config TEST_SCANF
2421 tristate "Test scanf() family of func 2258 tristate "Test scanf() family of functions at runtime"
2422 2259
2423 config TEST_BITMAP 2260 config TEST_BITMAP
2424 tristate "Test bitmap_*() family of f 2261 tristate "Test bitmap_*() family of functions at runtime"
2425 help 2262 help
2426 Enable this option to test the bitm 2263 Enable this option to test the bitmap functions at boot.
2427 2264
2428 If unsure, say N. 2265 If unsure, say N.
2429 2266
2430 config TEST_UUID 2267 config TEST_UUID
2431 tristate "Test functions located in t 2268 tristate "Test functions located in the uuid module at runtime"
2432 2269
2433 config TEST_XARRAY 2270 config TEST_XARRAY
2434 tristate "Test the XArray code at run 2271 tristate "Test the XArray code at runtime"
2435 2272
2436 config TEST_MAPLE_TREE 2273 config TEST_MAPLE_TREE
2437 tristate "Test the Maple Tree code at !! 2274 depends on DEBUG_KERNEL
2438 help !! 2275 select DEBUG_MAPLE_TREE
2439 Enable this option to test the mapl !! 2276 tristate "Test the Maple Tree code at runtime"
2440 when the module is loaded. Enable " <<
2441 more verbose output on failures. <<
2442 <<
2443 If unsure, say N. <<
2444 2277
2445 config TEST_RHASHTABLE 2278 config TEST_RHASHTABLE
2446 tristate "Perform selftest on resizab 2279 tristate "Perform selftest on resizable hash table"
2447 help 2280 help
2448 Enable this option to test the rhas 2281 Enable this option to test the rhashtable functions at boot.
2449 2282
2450 If unsure, say N. 2283 If unsure, say N.
2451 2284
2452 config TEST_IDA 2285 config TEST_IDA
2453 tristate "Perform selftest on IDA fun 2286 tristate "Perform selftest on IDA functions"
2454 2287
2455 config TEST_PARMAN 2288 config TEST_PARMAN
2456 tristate "Perform selftest on priorit 2289 tristate "Perform selftest on priority array manager"
2457 depends on PARMAN 2290 depends on PARMAN
2458 help 2291 help
2459 Enable this option to test priority 2292 Enable this option to test priority array manager on boot
2460 (or module load). 2293 (or module load).
2461 2294
2462 If unsure, say N. 2295 If unsure, say N.
2463 2296
2464 config TEST_IRQ_TIMINGS 2297 config TEST_IRQ_TIMINGS
2465 bool "IRQ timings selftest" 2298 bool "IRQ timings selftest"
2466 depends on IRQ_TIMINGS 2299 depends on IRQ_TIMINGS
2467 help 2300 help
2468 Enable this option to test the irq 2301 Enable this option to test the irq timings code on boot.
2469 2302
2470 If unsure, say N. 2303 If unsure, say N.
2471 2304
2472 config TEST_LKM 2305 config TEST_LKM
2473 tristate "Test module loading with 'h 2306 tristate "Test module loading with 'hello world' module"
2474 depends on m 2307 depends on m
2475 help 2308 help
2476 This builds the "test_module" modul 2309 This builds the "test_module" module that emits "Hello, world"
2477 on printk when loaded. It is design 2310 on printk when loaded. It is designed to be used for basic
2478 evaluation of the module loading su 2311 evaluation of the module loading subsystem (for example when
2479 validating module verification). It 2312 validating module verification). It lacks any extra dependencies,
2480 and will not normally be loaded by 2313 and will not normally be loaded by the system unless explicitly
2481 requested by name. 2314 requested by name.
2482 2315
2483 If unsure, say N. 2316 If unsure, say N.
2484 2317
2485 config TEST_BITOPS 2318 config TEST_BITOPS
2486 tristate "Test module for compilation 2319 tristate "Test module for compilation of bitops operations"
>> 2320 depends on m
2487 help 2321 help
2488 This builds the "test_bitops" modul 2322 This builds the "test_bitops" module that is much like the
2489 TEST_LKM module except that it does 2323 TEST_LKM module except that it does a basic exercise of the
2490 set/clear_bit macros and get_count_ 2324 set/clear_bit macros and get_count_order/long to make sure there are
2491 no compiler warnings from C=1 spars 2325 no compiler warnings from C=1 sparse checker or -Wextra
2492 compilations. It has no dependencie 2326 compilations. It has no dependencies and doesn't run or load unless
2493 explicitly requested by name. for 2327 explicitly requested by name. for example: modprobe test_bitops.
2494 2328
2495 If unsure, say N. 2329 If unsure, say N.
2496 2330
2497 config TEST_VMALLOC 2331 config TEST_VMALLOC
2498 tristate "Test module for stress/perf 2332 tristate "Test module for stress/performance analysis of vmalloc allocator"
2499 default n 2333 default n
2500 depends on MMU 2334 depends on MMU
2501 depends on m 2335 depends on m
2502 help 2336 help
2503 This builds the "test_vmalloc" modu 2337 This builds the "test_vmalloc" module that should be used for
2504 stress and performance analysis. So 2338 stress and performance analysis. So, any new change for vmalloc
2505 subsystem can be evaluated from per 2339 subsystem can be evaluated from performance and stability point
2506 of view. 2340 of view.
2507 2341
2508 If unsure, say N. 2342 If unsure, say N.
2509 2343
>> 2344 config TEST_USER_COPY
>> 2345 tristate "Test user/kernel boundary protections"
>> 2346 depends on m
>> 2347 help
>> 2348 This builds the "test_user_copy" module that runs sanity checks
>> 2349 on the copy_to/from_user infrastructure, making sure basic
>> 2350 user/kernel boundary testing is working. If it fails to load,
>> 2351 a regression has been detected in the user/kernel memory boundary
>> 2352 protections.
>> 2353
>> 2354 If unsure, say N.
>> 2355
2510 config TEST_BPF 2356 config TEST_BPF
2511 tristate "Test BPF filter functionali 2357 tristate "Test BPF filter functionality"
2512 depends on m && NET 2358 depends on m && NET
2513 help 2359 help
2514 This builds the "test_bpf" module t 2360 This builds the "test_bpf" module that runs various test vectors
2515 against the BPF interpreter or BPF 2361 against the BPF interpreter or BPF JIT compiler depending on the
2516 current setting. This is in particu 2362 current setting. This is in particular useful for BPF JIT compiler
2517 development, but also to run regres 2363 development, but also to run regression tests against changes in
2518 the interpreter code. It also enabl 2364 the interpreter code. It also enables test stubs for eBPF maps and
2519 verifier used by user space verifie 2365 verifier used by user space verifier testsuite.
2520 2366
2521 If unsure, say N. 2367 If unsure, say N.
2522 2368
2523 config TEST_BLACKHOLE_DEV 2369 config TEST_BLACKHOLE_DEV
2524 tristate "Test blackhole netdev funct 2370 tristate "Test blackhole netdev functionality"
2525 depends on m && NET 2371 depends on m && NET
2526 help 2372 help
2527 This builds the "test_blackhole_dev 2373 This builds the "test_blackhole_dev" module that validates the
2528 data path through this blackhole ne 2374 data path through this blackhole netdev.
2529 2375
2530 If unsure, say N. 2376 If unsure, say N.
2531 2377
2532 config FIND_BIT_BENCHMARK 2378 config FIND_BIT_BENCHMARK
2533 tristate "Test find_bit functions" 2379 tristate "Test find_bit functions"
2534 help 2380 help
2535 This builds the "test_find_bit" mod 2381 This builds the "test_find_bit" module that measure find_*_bit()
2536 functions performance. 2382 functions performance.
2537 2383
2538 If unsure, say N. 2384 If unsure, say N.
2539 2385
2540 config TEST_FIRMWARE 2386 config TEST_FIRMWARE
2541 tristate "Test firmware loading via u 2387 tristate "Test firmware loading via userspace interface"
2542 depends on FW_LOADER 2388 depends on FW_LOADER
2543 help 2389 help
2544 This builds the "test_firmware" mod 2390 This builds the "test_firmware" module that creates a userspace
2545 interface for testing firmware load 2391 interface for testing firmware loading. This can be used to
2546 control the triggering of firmware 2392 control the triggering of firmware loading without needing an
2547 actual firmware-using device. The c 2393 actual firmware-using device. The contents can be rechecked by
2548 userspace. 2394 userspace.
2549 2395
2550 If unsure, say N. 2396 If unsure, say N.
2551 2397
2552 config TEST_SYSCTL 2398 config TEST_SYSCTL
2553 tristate "sysctl test driver" 2399 tristate "sysctl test driver"
2554 depends on PROC_SYSCTL 2400 depends on PROC_SYSCTL
2555 help 2401 help
2556 This builds the "test_sysctl" modul 2402 This builds the "test_sysctl" module. This driver enables to test the
2557 proc sysctl interfaces available to 2403 proc sysctl interfaces available to drivers safely without affecting
2558 production knobs which might alter 2404 production knobs which might alter system functionality.
2559 2405
2560 If unsure, say N. 2406 If unsure, say N.
2561 2407
2562 config BITFIELD_KUNIT 2408 config BITFIELD_KUNIT
2563 tristate "KUnit test bitfield functio 2409 tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
2564 depends on KUNIT 2410 depends on KUNIT
2565 default KUNIT_ALL_TESTS 2411 default KUNIT_ALL_TESTS
2566 help 2412 help
2567 Enable this option to test the bitf 2413 Enable this option to test the bitfield functions at boot.
2568 2414
2569 KUnit tests run during boot and out 2415 KUnit tests run during boot and output the results to the debug log
2570 in TAP format (http://testanything. 2416 in TAP format (http://testanything.org/). Only useful for kernel devs
2571 running the KUnit test harness, and 2417 running the KUnit test harness, and not intended for inclusion into a
2572 production build. 2418 production build.
2573 2419
2574 For more information on KUnit and u 2420 For more information on KUnit and unit tests in general please refer
2575 to the KUnit documentation in Docum 2421 to the KUnit documentation in Documentation/dev-tools/kunit/.
2576 2422
2577 If unsure, say N. 2423 If unsure, say N.
2578 2424
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 2425 config HASH_KUNIT_TEST
2597 tristate "KUnit Test for integer hash 2426 tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
2598 depends on KUNIT 2427 depends on KUNIT
2599 default KUNIT_ALL_TESTS 2428 default KUNIT_ALL_TESTS
2600 help 2429 help
2601 Enable this option to test the kern 2430 Enable this option to test the kernel's string (<linux/stringhash.h>), and
2602 integer (<linux/hash.h>) hash funct 2431 integer (<linux/hash.h>) hash functions on boot.
2603 2432
2604 KUnit tests run during boot and out 2433 KUnit tests run during boot and output the results to the debug log
2605 in TAP format (https://testanything 2434 in TAP format (https://testanything.org/). Only useful for kernel devs
2606 running the KUnit test harness, and 2435 running the KUnit test harness, and not intended for inclusion into a
2607 production build. 2436 production build.
2608 2437
2609 For more information on KUnit and u 2438 For more information on KUnit and unit tests in general please refer
2610 to the KUnit documentation in Docum 2439 to the KUnit documentation in Documentation/dev-tools/kunit/.
2611 2440
2612 This is intended to help people wri 2441 This is intended to help people writing architecture-specific
2613 optimized versions. If unsure, say 2442 optimized versions. If unsure, say N.
2614 2443
2615 config RESOURCE_KUNIT_TEST 2444 config RESOURCE_KUNIT_TEST
2616 tristate "KUnit test for resource API 2445 tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
2617 depends on KUNIT 2446 depends on KUNIT
2618 default KUNIT_ALL_TESTS 2447 default KUNIT_ALL_TESTS
2619 help 2448 help
2620 This builds the resource API unit t 2449 This builds the resource API unit test.
2621 Tests the logic of API provided by 2450 Tests the logic of API provided by resource.c and ioport.h.
2622 For more information on KUnit and u 2451 For more information on KUnit and unit tests in general please refer
2623 to the KUnit documentation in Docum 2452 to the KUnit documentation in Documentation/dev-tools/kunit/.
2624 2453
2625 If unsure, say N. 2454 If unsure, say N.
2626 2455
2627 config SYSCTL_KUNIT_TEST 2456 config SYSCTL_KUNIT_TEST
2628 tristate "KUnit test for sysctl" if ! 2457 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2629 depends on KUNIT 2458 depends on KUNIT
2630 default KUNIT_ALL_TESTS 2459 default KUNIT_ALL_TESTS
2631 help 2460 help
2632 This builds the proc sysctl unit te 2461 This builds the proc sysctl unit test, which runs on boot.
2633 Tests the API contract and implemen 2462 Tests the API contract and implementation correctness of sysctl.
2634 For more information on KUnit and u 2463 For more information on KUnit and unit tests in general please refer
2635 to the KUnit documentation in Docum 2464 to the KUnit documentation in Documentation/dev-tools/kunit/.
2636 2465
2637 If unsure, say N. 2466 If unsure, say N.
2638 2467
2639 config LIST_KUNIT_TEST 2468 config LIST_KUNIT_TEST
2640 tristate "KUnit Test for Kernel Linke 2469 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2641 depends on KUNIT 2470 depends on KUNIT
2642 default KUNIT_ALL_TESTS 2471 default KUNIT_ALL_TESTS
2643 help 2472 help
2644 This builds the linked list KUnit t 2473 This builds the linked list KUnit test suite.
2645 It tests that the API and basic fun 2474 It tests that the API and basic functionality of the list_head type
2646 and associated macros. 2475 and associated macros.
2647 2476
2648 KUnit tests run during boot and out 2477 KUnit tests run during boot and output the results to the debug log
2649 in TAP format (https://testanything 2478 in TAP format (https://testanything.org/). Only useful for kernel devs
2650 running the KUnit test harness, and 2479 running the KUnit test harness, and not intended for inclusion into a
2651 production build. 2480 production build.
2652 2481
2653 For more information on KUnit and u 2482 For more information on KUnit and unit tests in general please refer
2654 to the KUnit documentation in Docum 2483 to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 2484
2656 If unsure, say N. 2485 If unsure, say N.
2657 2486
2658 config HASHTABLE_KUNIT_TEST 2487 config HASHTABLE_KUNIT_TEST
2659 tristate "KUnit Test for Kernel Hasht 2488 tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
2660 depends on KUNIT 2489 depends on KUNIT
2661 default KUNIT_ALL_TESTS 2490 default KUNIT_ALL_TESTS
2662 help 2491 help
2663 This builds the hashtable KUnit tes 2492 This builds the hashtable KUnit test suite.
2664 It tests the basic functionality of 2493 It tests the basic functionality of the API defined in
2665 include/linux/hashtable.h. For more 2494 include/linux/hashtable.h. For more information on KUnit and
2666 unit tests in general please refer 2495 unit tests in general please refer to the KUnit documentation
2667 in Documentation/dev-tools/kunit/. 2496 in Documentation/dev-tools/kunit/.
2668 2497
2669 If unsure, say N. 2498 If unsure, say N.
2670 2499
2671 config LINEAR_RANGES_TEST 2500 config LINEAR_RANGES_TEST
2672 tristate "KUnit test for linear_range 2501 tristate "KUnit test for linear_ranges"
2673 depends on KUNIT 2502 depends on KUNIT
2674 select LINEAR_RANGES 2503 select LINEAR_RANGES
2675 help 2504 help
2676 This builds the linear_ranges unit 2505 This builds the linear_ranges unit test, which runs on boot.
2677 Tests the linear_ranges logic corre 2506 Tests the linear_ranges logic correctness.
2678 For more information on KUnit and u 2507 For more information on KUnit and unit tests in general please refer
2679 to the KUnit documentation in Docum 2508 to the KUnit documentation in Documentation/dev-tools/kunit/.
2680 2509
2681 If unsure, say N. 2510 If unsure, say N.
2682 2511
2683 config CMDLINE_KUNIT_TEST 2512 config CMDLINE_KUNIT_TEST
2684 tristate "KUnit test for cmdline API" 2513 tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
2685 depends on KUNIT 2514 depends on KUNIT
2686 default KUNIT_ALL_TESTS 2515 default KUNIT_ALL_TESTS
2687 help 2516 help
2688 This builds the cmdline API unit te 2517 This builds the cmdline API unit test.
2689 Tests the logic of API provided by 2518 Tests the logic of API provided by cmdline.c.
2690 For more information on KUnit and u 2519 For more information on KUnit and unit tests in general please refer
2691 to the KUnit documentation in Docum 2520 to the KUnit documentation in Documentation/dev-tools/kunit/.
2692 2521
2693 If unsure, say N. 2522 If unsure, say N.
2694 2523
2695 config BITS_TEST 2524 config BITS_TEST
2696 tristate "KUnit test for bits.h" if ! 2525 tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
2697 depends on KUNIT 2526 depends on KUNIT
2698 default KUNIT_ALL_TESTS 2527 default KUNIT_ALL_TESTS
2699 help 2528 help
2700 This builds the bits unit test. 2529 This builds the bits unit test.
2701 Tests the logic of macros defined i 2530 Tests the logic of macros defined in bits.h.
2702 For more information on KUnit and u 2531 For more information on KUnit and unit tests in general please refer
2703 to the KUnit documentation in Docum 2532 to the KUnit documentation in Documentation/dev-tools/kunit/.
2704 2533
2705 If unsure, say N. 2534 If unsure, say N.
2706 2535
2707 config SLUB_KUNIT_TEST 2536 config SLUB_KUNIT_TEST
2708 tristate "KUnit test for SLUB cache e 2537 tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
2709 depends on SLUB_DEBUG && KUNIT 2538 depends on SLUB_DEBUG && KUNIT
2710 default KUNIT_ALL_TESTS 2539 default KUNIT_ALL_TESTS
2711 help 2540 help
2712 This builds SLUB allocator unit tes 2541 This builds SLUB allocator unit test.
2713 Tests SLUB cache debugging function 2542 Tests SLUB cache debugging functionality.
2714 For more information on KUnit and u 2543 For more information on KUnit and unit tests in general please refer
2715 to the KUnit documentation in Docum 2544 to the KUnit documentation in Documentation/dev-tools/kunit/.
2716 2545
2717 If unsure, say N. 2546 If unsure, say N.
2718 2547
2719 config RATIONAL_KUNIT_TEST 2548 config RATIONAL_KUNIT_TEST
2720 tristate "KUnit test for rational.c" 2549 tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
2721 depends on KUNIT && RATIONAL 2550 depends on KUNIT && RATIONAL
2722 default KUNIT_ALL_TESTS 2551 default KUNIT_ALL_TESTS
2723 help 2552 help
2724 This builds the rational math unit 2553 This builds the rational math unit test.
2725 For more information on KUnit and u 2554 For more information on KUnit and unit tests in general please refer
2726 to the KUnit documentation in Docum 2555 to the KUnit documentation in Documentation/dev-tools/kunit/.
2727 2556
2728 If unsure, say N. 2557 If unsure, say N.
2729 2558
2730 config MEMCPY_KUNIT_TEST 2559 config MEMCPY_KUNIT_TEST
2731 tristate "Test memcpy(), memmove(), a 2560 tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
2732 depends on KUNIT 2561 depends on KUNIT
2733 default KUNIT_ALL_TESTS 2562 default KUNIT_ALL_TESTS
2734 help 2563 help
2735 Builds unit tests for memcpy(), mem 2564 Builds unit tests for memcpy(), memmove(), and memset() functions.
2736 For more information on KUnit and u 2565 For more information on KUnit and unit tests in general please refer
2737 to the KUnit documentation in Docum 2566 to the KUnit documentation in Documentation/dev-tools/kunit/.
2738 2567
2739 If unsure, say N. 2568 If unsure, say N.
2740 2569
>> 2570 config MEMCPY_SLOW_KUNIT_TEST
>> 2571 bool "Include exhaustive memcpy tests"
>> 2572 depends on MEMCPY_KUNIT_TEST
>> 2573 default y
>> 2574 help
>> 2575 Some memcpy tests are quite exhaustive in checking for overlaps
>> 2576 and bit ranges. These can be very slow, so they are split out
>> 2577 as a separate config, in case they need to be disabled.
>> 2578
2741 config IS_SIGNED_TYPE_KUNIT_TEST 2579 config IS_SIGNED_TYPE_KUNIT_TEST
2742 tristate "Test is_signed_type() macro 2580 tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
2743 depends on KUNIT 2581 depends on KUNIT
2744 default KUNIT_ALL_TESTS 2582 default KUNIT_ALL_TESTS
2745 help 2583 help
2746 Builds unit tests for the is_signed 2584 Builds unit tests for the is_signed_type() macro.
2747 2585
2748 For more information on KUnit and u 2586 For more information on KUnit and unit tests in general please refer
2749 to the KUnit documentation in Docum 2587 to the KUnit documentation in Documentation/dev-tools/kunit/.
2750 2588
2751 If unsure, say N. 2589 If unsure, say N.
2752 2590
2753 config OVERFLOW_KUNIT_TEST 2591 config OVERFLOW_KUNIT_TEST
2754 tristate "Test check_*_overflow() fun 2592 tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
2755 depends on KUNIT 2593 depends on KUNIT
2756 default KUNIT_ALL_TESTS 2594 default KUNIT_ALL_TESTS
2757 help 2595 help
2758 Builds unit tests for the check_*_o 2596 Builds unit tests for the check_*_overflow(), size_*(), allocation, and
2759 related functions. 2597 related functions.
2760 2598
2761 For more information on KUnit and u 2599 For more information on KUnit and unit tests in general please refer
2762 to the KUnit documentation in Docum 2600 to the KUnit documentation in Documentation/dev-tools/kunit/.
2763 2601
2764 If unsure, say N. 2602 If unsure, say N.
2765 2603
2766 config STACKINIT_KUNIT_TEST 2604 config STACKINIT_KUNIT_TEST
2767 tristate "Test level of stack variabl 2605 tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
2768 depends on KUNIT 2606 depends on KUNIT
2769 default KUNIT_ALL_TESTS 2607 default KUNIT_ALL_TESTS
2770 help 2608 help
2771 Test if the kernel is zero-initiali 2609 Test if the kernel is zero-initializing stack variables and
2772 padding. Coverage is controlled by 2610 padding. Coverage is controlled by compiler flags,
2773 CONFIG_INIT_STACK_ALL_PATTERN, CONF 2611 CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
2774 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFI 2612 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2775 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYR 2613 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2776 2614
2777 config FORTIFY_KUNIT_TEST 2615 config FORTIFY_KUNIT_TEST
2778 tristate "Test fortified str*() and m 2616 tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
2779 depends on KUNIT !! 2617 depends on KUNIT && FORTIFY_SOURCE
2780 default KUNIT_ALL_TESTS 2618 default KUNIT_ALL_TESTS
2781 help 2619 help
2782 Builds unit tests for checking inte 2620 Builds unit tests for checking internals of FORTIFY_SOURCE as used
2783 by the str*() and mem*() family of 2621 by the str*() and mem*() family of functions. For testing runtime
2784 traps of FORTIFY_SOURCE, see LKDTM' 2622 traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
2785 2623
2786 config HW_BREAKPOINT_KUNIT_TEST 2624 config HW_BREAKPOINT_KUNIT_TEST
2787 bool "Test hw_breakpoint constraints 2625 bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
2788 depends on HAVE_HW_BREAKPOINT 2626 depends on HAVE_HW_BREAKPOINT
2789 depends on KUNIT=y 2627 depends on KUNIT=y
2790 default KUNIT_ALL_TESTS 2628 default KUNIT_ALL_TESTS
2791 help 2629 help
2792 Tests for hw_breakpoint constraints 2630 Tests for hw_breakpoint constraints accounting.
2793 2631
2794 If unsure, say N. 2632 If unsure, say N.
2795 2633
>> 2634 config STRSCPY_KUNIT_TEST
>> 2635 tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
>> 2636 depends on KUNIT
>> 2637 default KUNIT_ALL_TESTS
>> 2638
2796 config SIPHASH_KUNIT_TEST 2639 config SIPHASH_KUNIT_TEST
2797 tristate "Perform selftest on siphash 2640 tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
2798 depends on KUNIT 2641 depends on KUNIT
2799 default KUNIT_ALL_TESTS 2642 default KUNIT_ALL_TESTS
2800 help 2643 help
2801 Enable this option to test the kern 2644 Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
2802 functions on boot (or module load). 2645 functions on boot (or module load).
2803 2646
2804 This is intended to help people wri 2647 This is intended to help people writing architecture-specific
2805 optimized versions. If unsure, say 2648 optimized versions. If unsure, say N.
2806 2649
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 2650 config TEST_UDELAY
2817 tristate "udelay test driver" 2651 tristate "udelay test driver"
2818 help 2652 help
2819 This builds the "udelay_test" modul 2653 This builds the "udelay_test" module that helps to make sure
2820 that udelay() is working properly. 2654 that udelay() is working properly.
2821 2655
2822 If unsure, say N. 2656 If unsure, say N.
2823 2657
2824 config TEST_STATIC_KEYS 2658 config TEST_STATIC_KEYS
2825 tristate "Test static keys" 2659 tristate "Test static keys"
2826 depends on m 2660 depends on m
2827 help 2661 help
2828 Test the static key interfaces. 2662 Test the static key interfaces.
2829 2663
2830 If unsure, say N. 2664 If unsure, say N.
2831 2665
2832 config TEST_DYNAMIC_DEBUG 2666 config TEST_DYNAMIC_DEBUG
2833 tristate "Test DYNAMIC_DEBUG" 2667 tristate "Test DYNAMIC_DEBUG"
2834 depends on DYNAMIC_DEBUG 2668 depends on DYNAMIC_DEBUG
2835 help 2669 help
2836 This module registers a tracer call 2670 This module registers a tracer callback to count enabled
2837 pr_debugs in a 'do_debugging' funct 2671 pr_debugs in a 'do_debugging' function, then alters their
2838 enablements, calls the function, an 2672 enablements, calls the function, and compares counts.
2839 2673
2840 If unsure, say N. 2674 If unsure, say N.
2841 2675
2842 config TEST_KMOD 2676 config TEST_KMOD
2843 tristate "kmod stress tester" 2677 tristate "kmod stress tester"
2844 depends on m 2678 depends on m
2845 depends on NETDEVICES && NET_CORE && 2679 depends on NETDEVICES && NET_CORE && INET # for TUN
2846 depends on BLOCK 2680 depends on BLOCK
2847 depends on PAGE_SIZE_LESS_THAN_256KB 2681 depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
2848 select TEST_LKM 2682 select TEST_LKM
2849 select XFS_FS 2683 select XFS_FS
2850 select TUN 2684 select TUN
2851 select BTRFS_FS 2685 select BTRFS_FS
2852 help 2686 help
2853 Test the kernel's module loading me 2687 Test the kernel's module loading mechanism: kmod. kmod implements
2854 support to load modules using the L 2688 support to load modules using the Linux kernel's usermode helper.
2855 This test provides a series of test 2689 This test provides a series of tests against kmod.
2856 2690
2857 Although technically you can either 2691 Although technically you can either build test_kmod as a module or
2858 into the kernel we disallow buildin 2692 into the kernel we disallow building it into the kernel since
2859 it stress tests request_module() an 2693 it stress tests request_module() and this will very likely cause
2860 some issues by taking over precious 2694 some issues by taking over precious threads available from other
2861 module load requests, ultimately th 2695 module load requests, ultimately this could be fatal.
2862 2696
2863 To run tests run: 2697 To run tests run:
2864 2698
2865 tools/testing/selftests/kmod/kmod.s 2699 tools/testing/selftests/kmod/kmod.sh --help
2866 2700
2867 If unsure, say N. 2701 If unsure, say N.
2868 2702
2869 config TEST_DEBUG_VIRTUAL 2703 config TEST_DEBUG_VIRTUAL
2870 tristate "Test CONFIG_DEBUG_VIRTUAL f 2704 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2871 depends on DEBUG_VIRTUAL 2705 depends on DEBUG_VIRTUAL
2872 help 2706 help
2873 Test the kernel's ability to detect 2707 Test the kernel's ability to detect incorrect calls to
2874 virt_to_phys() done against the non 2708 virt_to_phys() done against the non-linear part of the
2875 kernel's virtual address map. 2709 kernel's virtual address map.
2876 2710
2877 If unsure, say N. 2711 If unsure, say N.
2878 2712
2879 config TEST_MEMCAT_P 2713 config TEST_MEMCAT_P
2880 tristate "Test memcat_p() helper func 2714 tristate "Test memcat_p() helper function"
2881 help 2715 help
2882 Test the memcat_p() helper for corr 2716 Test the memcat_p() helper for correctly merging two
2883 pointer arrays together. 2717 pointer arrays together.
2884 2718
2885 If unsure, say N. 2719 If unsure, say N.
2886 2720
>> 2721 config TEST_LIVEPATCH
>> 2722 tristate "Test livepatching"
>> 2723 default n
>> 2724 depends on DYNAMIC_DEBUG
>> 2725 depends on LIVEPATCH
>> 2726 depends on m
>> 2727 help
>> 2728 Test kernel livepatching features for correctness. The tests will
>> 2729 load test modules that will be livepatched in various scenarios.
>> 2730
>> 2731 To run all the livepatching tests:
>> 2732
>> 2733 make -C tools/testing/selftests TARGETS=livepatch run_tests
>> 2734
>> 2735 Alternatively, individual tests may be invoked:
>> 2736
>> 2737 tools/testing/selftests/livepatch/test-callbacks.sh
>> 2738 tools/testing/selftests/livepatch/test-livepatch.sh
>> 2739 tools/testing/selftests/livepatch/test-shadow-vars.sh
>> 2740
>> 2741 If unsure, say N.
>> 2742
2887 config TEST_OBJAGG 2743 config TEST_OBJAGG
2888 tristate "Perform selftest on object 2744 tristate "Perform selftest on object aggreration manager"
2889 default n 2745 default n
2890 depends on OBJAGG 2746 depends on OBJAGG
2891 help 2747 help
2892 Enable this option to test object a 2748 Enable this option to test object aggregation manager on boot
2893 (or module load). 2749 (or module load).
2894 2750
2895 config TEST_MEMINIT 2751 config TEST_MEMINIT
2896 tristate "Test heap/page initializati 2752 tristate "Test heap/page initialization"
2897 help 2753 help
2898 Test if the kernel is zero-initiali 2754 Test if the kernel is zero-initializing heap and page allocations.
2899 This can be useful to test init_on_ 2755 This can be useful to test init_on_alloc and init_on_free features.
2900 2756
2901 If unsure, say N. 2757 If unsure, say N.
2902 2758
2903 config TEST_HMM 2759 config TEST_HMM
2904 tristate "Test HMM (Heterogeneous Mem 2760 tristate "Test HMM (Heterogeneous Memory Management)"
2905 depends on TRANSPARENT_HUGEPAGE 2761 depends on TRANSPARENT_HUGEPAGE
2906 depends on DEVICE_PRIVATE 2762 depends on DEVICE_PRIVATE
2907 select HMM_MIRROR 2763 select HMM_MIRROR
2908 select MMU_NOTIFIER 2764 select MMU_NOTIFIER
2909 help 2765 help
2910 This is a pseudo device driver sole 2766 This is a pseudo device driver solely for testing HMM.
2911 Say M here if you want to build the 2767 Say M here if you want to build the HMM test module.
2912 Doing so will allow you to run tool 2768 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2913 2769
2914 If unsure, say N. 2770 If unsure, say N.
2915 2771
2916 config TEST_FREE_PAGES 2772 config TEST_FREE_PAGES
2917 tristate "Test freeing pages" 2773 tristate "Test freeing pages"
2918 help 2774 help
2919 Test that a memory leak does not oc 2775 Test that a memory leak does not occur due to a race between
2920 freeing a block of pages and a spec 2776 freeing a block of pages and a speculative page reference.
2921 Loading this module is safe if your 2777 Loading this module is safe if your kernel has the bug fixed.
2922 If the bug is not fixed, it will le 2778 If the bug is not fixed, it will leak gigabytes of memory and
2923 probably OOM your system. 2779 probably OOM your system.
2924 2780
2925 config TEST_FPU 2781 config TEST_FPU
2926 tristate "Test floating point operati 2782 tristate "Test floating point operations in kernel space"
2927 depends on ARCH_HAS_KERNEL_FPU_SUPPOR !! 2783 depends on X86 && !KCOV_INSTRUMENT_ALL
2928 help 2784 help
2929 Enable this option to add /sys/kern 2785 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2930 which will trigger a sequence of fl 2786 which will trigger a sequence of floating point operations. This is used
2931 for self-testing floating point con 2787 for self-testing floating point control register setting in
2932 kernel_fpu_begin(). 2788 kernel_fpu_begin().
2933 2789
2934 If unsure, say N. 2790 If unsure, say N.
2935 2791
2936 config TEST_CLOCKSOURCE_WATCHDOG 2792 config TEST_CLOCKSOURCE_WATCHDOG
2937 tristate "Test clocksource watchdog i 2793 tristate "Test clocksource watchdog in kernel space"
2938 depends on CLOCKSOURCE_WATCHDOG 2794 depends on CLOCKSOURCE_WATCHDOG
2939 help 2795 help
2940 Enable this option to create a kern 2796 Enable this option to create a kernel module that will trigger
2941 a test of the clocksource watchdog. 2797 a test of the clocksource watchdog. This module may be loaded
2942 via modprobe or insmod in which cas 2798 via modprobe or insmod in which case it will run upon being
2943 loaded, or it may be built in, in w 2799 loaded, or it may be built in, in which case it will run
2944 shortly after boot. 2800 shortly after boot.
2945 2801
2946 If unsure, say N. 2802 If unsure, say N.
2947 2803
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 2804 endif # RUNTIME_TESTING_MENU
2960 2805
2961 config ARCH_USE_MEMTEST 2806 config ARCH_USE_MEMTEST
2962 bool 2807 bool
2963 help 2808 help
2964 An architecture should select this 2809 An architecture should select this when it uses early_memtest()
2965 during boot process. 2810 during boot process.
2966 2811
2967 config MEMTEST 2812 config MEMTEST
2968 bool "Memtest" 2813 bool "Memtest"
2969 depends on ARCH_USE_MEMTEST 2814 depends on ARCH_USE_MEMTEST
2970 help 2815 help
2971 This option adds a kernel parameter 2816 This option adds a kernel parameter 'memtest', which allows memtest
2972 to be set and executed. 2817 to be set and executed.
2973 memtest=0, mean disabled; -- 2818 memtest=0, mean disabled; -- default
2974 memtest=1, mean do 1 test pat 2819 memtest=1, mean do 1 test pattern;
2975 ... 2820 ...
2976 memtest=17, mean do 17 test p 2821 memtest=17, mean do 17 test patterns.
2977 If you are unsure how to answer thi 2822 If you are unsure how to answer this question, answer N.
2978 2823
2979 2824
2980 2825
2981 config HYPERV_TESTING 2826 config HYPERV_TESTING
2982 bool "Microsoft Hyper-V driver testin 2827 bool "Microsoft Hyper-V driver testing"
2983 default n 2828 default n
2984 depends on HYPERV && DEBUG_FS 2829 depends on HYPERV && DEBUG_FS
2985 help 2830 help
2986 Select this option to enable Hyper- 2831 Select this option to enable Hyper-V vmbus testing.
2987 2832
2988 endmenu # "Kernel Testing and Coverage" 2833 endmenu # "Kernel Testing and Coverage"
2989 2834
2990 menu "Rust hacking" 2835 menu "Rust hacking"
2991 2836
2992 config RUST_DEBUG_ASSERTIONS 2837 config RUST_DEBUG_ASSERTIONS
2993 bool "Debug assertions" 2838 bool "Debug assertions"
2994 depends on RUST 2839 depends on RUST
2995 help 2840 help
2996 Enables rustc's `-Cdebug-assertions 2841 Enables rustc's `-Cdebug-assertions` codegen option.
2997 2842
2998 This flag lets you turn `cfg(debug_ 2843 This flag lets you turn `cfg(debug_assertions)` conditional
2999 compilation on or off. This can be 2844 compilation on or off. This can be used to enable extra debugging
3000 code in development but not in prod 2845 code in development but not in production. For example, it controls
3001 the behavior of the standard librar 2846 the behavior of the standard library's `debug_assert!` macro.
3002 2847
3003 Note that this will apply to all Ru 2848 Note that this will apply to all Rust code, including `core`.
3004 2849
3005 If unsure, say N. 2850 If unsure, say N.
3006 2851
3007 config RUST_OVERFLOW_CHECKS 2852 config RUST_OVERFLOW_CHECKS
3008 bool "Overflow checks" 2853 bool "Overflow checks"
3009 default y 2854 default y
3010 depends on RUST 2855 depends on RUST
3011 help 2856 help
3012 Enables rustc's `-Coverflow-checks` 2857 Enables rustc's `-Coverflow-checks` codegen option.
3013 2858
3014 This flag allows you to control the 2859 This flag allows you to control the behavior of runtime integer
3015 overflow. When overflow-checks are 2860 overflow. When overflow-checks are enabled, a Rust panic will occur
3016 on overflow. 2861 on overflow.
3017 2862
3018 Note that this will apply to all Ru 2863 Note that this will apply to all Rust code, including `core`.
3019 2864
3020 If unsure, say Y. 2865 If unsure, say Y.
3021 2866
3022 config RUST_BUILD_ASSERT_ALLOW 2867 config RUST_BUILD_ASSERT_ALLOW
3023 bool "Allow unoptimized build-time as 2868 bool "Allow unoptimized build-time assertions"
3024 depends on RUST 2869 depends on RUST
3025 help 2870 help
3026 Controls how are `build_error!` and 2871 Controls how are `build_error!` and `build_assert!` handled during build.
3027 2872
3028 If calls to them exist in the binar 2873 If calls to them exist in the binary, it may indicate a violated invariant
3029 or that the optimizer failed to ver 2874 or that the optimizer failed to verify the invariant during compilation.
3030 2875
3031 This should not happen, thus by def 2876 This should not happen, thus by default the build is aborted. However,
3032 as an escape hatch, you can choose 2877 as an escape hatch, you can choose Y here to ignore them during build
3033 and let the check be carried at run 2878 and let the check be carried at runtime (with `panic!` being called if
3034 the check fails). 2879 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 2880
3049 If unsure, say N. 2881 If unsure, say N.
3050 2882
3051 endmenu # "Rust" 2883 endmenu # "Rust"
3052 2884
3053 endmenu # Kernel hacking 2885 endmenu # Kernel hacking
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