ubsan: include bug type in report header
[linux-2.6-block.git] / lib / Kconfig.debug
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ec8f24b7 1# SPDX-License-Identifier: GPL-2.0-only
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2menu "Kernel hacking"
3
604ff0dc 4menu "printk and dmesg options"
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5
6config PRINTK_TIME
7 bool "Show timing information on printks"
d3b8b6e5 8 depends on PRINTK
1da177e4 9 help
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10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
13
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
17
18 The behavior is also controlled by the kernel command line
8c27ceff 19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
1da177e4 20
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21config PRINTK_CALLER
22 bool "Show caller information on printks"
23 depends on PRINTK
24 help
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
27 to every message.
28
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
33
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
36 sysfs interface.
37
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38config CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
40 range 1 15
41 default "7"
42 help
43 Default loglevel to determine what will be printed on the console.
44
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
48
50f4d9bd 49 Note: This does not affect the log level of un-prefixed printk()
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50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
51 option.
52
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53config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
55 range 1 15
56 default "4"
57 help
58 loglevel to use when "quiet" is passed on the kernel commandline.
59
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
63
42a9dc0b 64config MESSAGE_LOGLEVEL_DEFAULT
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65 int "Default message log level (1-7)"
66 range 1 7
67 default "4"
68 help
69 Default log level for printk statements with no specified priority.
70
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
73 priority.
74
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75 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
78
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79config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
82 help
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
86 using "boot_delay=N".
87
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
96
97config DYNAMIC_DEBUG
98 bool "Enable dynamic printk() support"
99 default n
100 depends on PRINTK
239a5791 101 depends on (DEBUG_FS || PROC_FS)
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102 help
103
104 Compiles debug level messages into the kernel, which would not
105 otherwise be available at runtime. These messages can then be
106 enabled/disabled based on various levels of scope - per source file,
107 function, module, format string, and line number. This mechanism
108 implicitly compiles in all pr_debug() and dev_dbg() calls, which
109 enlarges the kernel text size by about 2%.
110
111 If a source file is compiled with DEBUG flag set, any
112 pr_debug() calls in it are enabled by default, but can be
113 disabled at runtime as below. Note that DEBUG flag is
114 turned on by many CONFIG_*DEBUG* options.
115
116 Usage:
117
118 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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119 which is contained in the 'debugfs' filesystem or procfs.
120 Thus, the debugfs or procfs filesystem must first be mounted before
121 making use of this feature.
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122 We refer the control file as: <debugfs>/dynamic_debug/control. This
123 file contains a list of the debug statements that can be enabled. The
124 format for each line of the file is:
125
126 filename:lineno [module]function flags format
127
128 filename : source file of the debug statement
129 lineno : line number of the debug statement
130 module : module that contains the debug statement
131 function : function that contains the debug statement
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132 flags : '=p' means the line is turned 'on' for printing
133 format : the format used for the debug statement
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134
135 From a live system:
136
137 nullarbor:~ # cat <debugfs>/dynamic_debug/control
138 # filename:lineno [module]function flags format
139 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
140 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
141 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
142
143 Example usage:
144
145 // enable the message at line 1603 of file svcsock.c
146 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
147 <debugfs>/dynamic_debug/control
148
149 // enable all the messages in file svcsock.c
150 nullarbor:~ # echo -n 'file svcsock.c +p' >
151 <debugfs>/dynamic_debug/control
152
153 // enable all the messages in the NFS server module
154 nullarbor:~ # echo -n 'module nfsd +p' >
155 <debugfs>/dynamic_debug/control
156
157 // enable all 12 messages in the function svc_process()
158 nullarbor:~ # echo -n 'func svc_process +p' >
159 <debugfs>/dynamic_debug/control
160
161 // disable all 12 messages in the function svc_process()
162 nullarbor:~ # echo -n 'func svc_process -p' >
163 <debugfs>/dynamic_debug/control
164
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165 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
166 information.
604ff0dc 167
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168config SYMBOLIC_ERRNAME
169 bool "Support symbolic error names in printf"
170 default y if PRINTK
171 help
172 If you say Y here, the kernel's printf implementation will
173 be able to print symbolic error names such as ENOSPC instead
174 of the number 28. It makes the kernel image slightly larger
175 (about 3KB), but can make the kernel logs easier to read.
176
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177config DEBUG_BUGVERBOSE
178 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
179 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
180 default y
181 help
182 Say Y here to make BUG() panics output the file name and line number
183 of the BUG call as well as the EIP and oops trace. This aids
184 debugging but costs about 70-100K of memory.
185
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186endmenu # "printk and dmesg options"
187
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188menu "Compile-time checks and compiler options"
189
190config DEBUG_INFO
191 bool "Compile the kernel with debug info"
12b13835 192 depends on DEBUG_KERNEL && !COMPILE_TEST
6dfc0665 193 help
68d4b3df 194 If you say Y here the resulting kernel image will include
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195 debugging info resulting in a larger kernel image.
196 This adds debug symbols to the kernel and modules (gcc -g), and
197 is needed if you intend to use kernel crashdump or binary object
198 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
199 Say Y here only if you plan to debug the kernel.
200
201 If unsure, say N.
202
203config DEBUG_INFO_REDUCED
204 bool "Reduce debugging information"
205 depends on DEBUG_INFO
206 help
207 If you say Y here gcc is instructed to generate less debugging
208 information for structure types. This means that tools that
209 need full debugging information (like kgdb or systemtap) won't
210 be happy. But if you merely need debugging information to
211 resolve line numbers there is no loss. Advantage is that
212 build directory object sizes shrink dramatically over a full
213 DEBUG_INFO build and compile times are reduced too.
214 Only works with newer gcc versions.
215
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216config DEBUG_INFO_SPLIT
217 bool "Produce split debuginfo in .dwo files"
a687a533 218 depends on DEBUG_INFO
9d937444 219 depends on $(cc-option,-gsplit-dwarf)
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220 help
221 Generate debug info into separate .dwo files. This significantly
222 reduces the build directory size for builds with DEBUG_INFO,
223 because it stores the information only once on disk in .dwo
224 files instead of multiple times in object files and executables.
225 In addition the debug information is also compressed.
226
227 Requires recent gcc (4.7+) and recent gdb/binutils.
228 Any tool that packages or reads debug information would need
229 to know about the .dwo files and include them.
230 Incompatible with older versions of ccache.
231
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232config DEBUG_INFO_DWARF4
233 bool "Generate dwarf4 debuginfo"
234 depends on DEBUG_INFO
9d937444 235 depends on $(cc-option,-gdwarf-4)
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236 help
237 Generate dwarf4 debug info. This requires recent versions
238 of gcc and gdb. It makes the debug information larger.
239 But it significantly improves the success of resolving
240 variables in gdb on optimized code.
241
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242config DEBUG_INFO_BTF
243 bool "Generate BTF typeinfo"
244 depends on DEBUG_INFO
245 help
246 Generate deduplicated BTF type information from DWARF debug info.
247 Turning this on expects presence of pahole tool, which will convert
248 DWARF type info into equivalent deduplicated BTF type info.
249
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250config GDB_SCRIPTS
251 bool "Provide GDB scripts for kernel debugging"
252 depends on DEBUG_INFO
253 help
254 This creates the required links to GDB helper scripts in the
255 build directory. If you load vmlinux into gdb, the helper
256 scripts will be automatically imported by gdb as well, and
257 additional functions are available to analyze a Linux kernel
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258 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
259 for further details.
3ee7b3fa 260
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261config ENABLE_MUST_CHECK
262 bool "Enable __must_check logic"
263 default y
264 help
265 Enable the __must_check logic in the kernel build. Disable this to
266 suppress the "warning: ignoring return value of 'foo', declared with
267 attribute warn_unused_result" messages.
1da177e4 268
35bb5b1e 269config FRAME_WARN
a83e4ca2 270 int "Warn for stack frames larger than"
35bb5b1e 271 range 0 8192
0e07f663 272 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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273 default 1280 if (!64BIT && PARISC)
274 default 1024 if (!64BIT && !PARISC)
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275 default 2048 if 64BIT
276 help
277 Tell gcc to warn at build time for stack frames larger than this.
278 Setting this too low will cause a lot of warnings.
279 Setting it to 0 disables the warning.
35bb5b1e 280
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281config STRIP_ASM_SYMS
282 bool "Strip assembler-generated symbols during link"
283 default n
284 help
285 Strip internal assembler-generated symbols during a link (symbols
286 that look like '.Lxxx') so they don't pollute the output of
287 get_wchan() and suchlike.
288
1873e870 289config READABLE_ASM
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290 bool "Generate readable assembler code"
291 depends on DEBUG_KERNEL
bf4735a4 292 help
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293 Disable some compiler optimizations that tend to generate human unreadable
294 assembler output. This may make the kernel slightly slower, but it helps
295 to keep kernel developers who have to stare a lot at assembler listings
296 sane.
bf4735a4 297
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298config HEADERS_INSTALL
299 bool "Install uapi headers to usr/include"
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300 depends on !UML
301 help
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302 This option will install uapi headers (headers exported to user-space)
303 into the usr/include directory for use during the kernel build.
304 This is unneeded for building the kernel itself, but needed for some
305 user-space program samples. It is also needed by some features such
306 as uapi header sanity checks.
307
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308config DEBUG_SECTION_MISMATCH
309 bool "Enable full Section mismatch analysis"
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310 help
311 The section mismatch analysis checks if there are illegal
312 references from one section to another section.
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313 During linktime or runtime, some sections are dropped;
314 any use of code/data previously in these sections would
91341d4b 315 most likely result in an oops.
e809ab01 316 In the code, functions and variables are annotated with
0db0628d 317 __init,, etc. (see the full list in include/linux/init.h),
d6fbfa4f 318 which results in the code/data being placed in specific sections.
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319 The section mismatch analysis is always performed after a full
320 kernel build, and enabling this option causes the following
b7dca6dd 321 additional step to occur:
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322 - Add the option -fno-inline-functions-called-once to gcc commands.
323 When inlining a function annotated with __init in a non-init
324 function, we would lose the section information and thus
91341d4b 325 the analysis would not catch the illegal reference.
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326 This option tells gcc to inline less (but it does result in
327 a larger kernel).
91341d4b 328
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329config SECTION_MISMATCH_WARN_ONLY
330 bool "Make section mismatch errors non-fatal"
331 default y
332 help
333 If you say N here, the build process will fail if there are any
334 section mismatch, instead of just throwing warnings.
335
336 If unsure, say Y.
337
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338#
339# Select this config option from the architecture Kconfig, if it
340# is preferred to always offer frame pointers as a config
341# option on the architecture (regardless of KERNEL_DEBUG):
342#
343config ARCH_WANT_FRAME_POINTERS
344 bool
f346f4b3 345
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346config FRAME_POINTER
347 bool "Compile the kernel with frame pointers"
a687a533 348 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
6dfc0665 349 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
a304e1b8 350 help
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351 If you say Y here the resulting kernel image will be slightly
352 larger and slower, but it gives very useful debugging information
353 in case of kernel bugs. (precise oopses/stacktraces/warnings)
a304e1b8 354
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355config STACK_VALIDATION
356 bool "Compile-time stack metadata validation"
357 depends on HAVE_STACK_VALIDATION
358 default n
359 help
360 Add compile-time checks to validate stack metadata, including frame
361 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
362 that runtime stack traces are more reliable.
363
ee9f8fce 364 This is also a prerequisite for generation of ORC unwind data, which
11af8474 365 is needed for CONFIG_UNWINDER_ORC.
ee9f8fce 366
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367 For more information, see
368 tools/objtool/Documentation/stack-validation.txt.
369
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370config DEBUG_FORCE_WEAK_PER_CPU
371 bool "Force weak per-cpu definitions"
372 depends on DEBUG_KERNEL
8446f1d3 373 help
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374 s390 and alpha require percpu variables in modules to be
375 defined weak to work around addressing range issue which
376 puts the following two restrictions on percpu variable
377 definitions.
8446f1d3 378
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379 1. percpu symbols must be unique whether static or not
380 2. percpu variables can't be defined inside a function
8446f1d3 381
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382 To ensure that generic code follows the above rules, this
383 option forces all percpu variables to be defined as weak.
5f329089 384
6dfc0665 385endmenu # "Compiler options"
8446f1d3 386
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387menu "Generic Kernel Debugging Instruments"
388
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389config MAGIC_SYSRQ
390 bool "Magic SysRq key"
391 depends on !UML
392 help
393 If you say Y here, you will have some control over the system even
394 if the system crashes for example during kernel debugging (e.g., you
395 will be able to flush the buffer cache to disk, reboot the system
396 immediately or dump some status information). This is accomplished
397 by pressing various keys while holding SysRq (Alt+PrintScreen). It
398 also works on a serial console (on PC hardware at least), if you
399 send a BREAK and then within 5 seconds a command keypress. The
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400 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
401 Don't say Y unless you really know what this hack does.
8446f1d3 402
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403config MAGIC_SYSRQ_DEFAULT_ENABLE
404 hex "Enable magic SysRq key functions by default"
405 depends on MAGIC_SYSRQ
406 default 0x1
407 help
408 Specifies which SysRq key functions are enabled by default.
409 This may be set to 1 or 0 to enable or disable them all, or
f8998c22 410 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
8eaede49 411
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412config MAGIC_SYSRQ_SERIAL
413 bool "Enable magic SysRq key over serial"
414 depends on MAGIC_SYSRQ
415 default y
416 help
417 Many embedded boards have a disconnected TTL level serial which can
418 generate some garbage that can lead to spurious false sysrq detects.
419 This option allows you to decide whether you want to enable the
420 magic SysRq key.
421
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422config MAGIC_SYSRQ_SERIAL_SEQUENCE
423 string "Char sequence that enables magic SysRq over serial"
424 depends on MAGIC_SYSRQ_SERIAL
425 default ""
426 help
427 Specifies a sequence of characters that can follow BREAK to enable
428 SysRq on a serial console.
429
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430 If unsure, leave an empty string and the option will not be enabled.
431
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432config DEBUG_FS
433 bool "Debug Filesystem"
434 help
435 debugfs is a virtual file system that kernel developers use to put
436 debugging files into. Enable this option to be able to read and
437 write to these files.
438
439 For detailed documentation on the debugfs API, see
440 Documentation/filesystems/.
441
442 If unsure, say N.
443
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444source "lib/Kconfig.kgdb"
445
446source "lib/Kconfig.ubsan"
447
448endmenu
449
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450config DEBUG_KERNEL
451 bool "Kernel debugging"
fef2c9bc 452 help
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453 Say Y here if you are developing drivers or trying to debug and
454 identify kernel problems.
fef2c9bc 455
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456config DEBUG_MISC
457 bool "Miscellaneous debug code"
458 default DEBUG_KERNEL
459 depends on DEBUG_KERNEL
460 help
461 Say Y here if you need to enable miscellaneous debug code that should
462 be under a more specific debug option but isn't.
463
464
0610c8a8 465menu "Memory Debugging"
fef2c9bc 466
8636a1f9 467source "mm/Kconfig.debug"
fef2c9bc 468
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469config DEBUG_OBJECTS
470 bool "Debug object operations"
471 depends on DEBUG_KERNEL
9c44bc03 472 help
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473 If you say Y here, additional code will be inserted into the
474 kernel to track the life time of various objects and validate
475 the operations on those objects.
9c44bc03 476
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477config DEBUG_OBJECTS_SELFTEST
478 bool "Debug objects selftest"
479 depends on DEBUG_OBJECTS
480 help
481 This enables the selftest of the object debug code.
9c44bc03 482
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483config DEBUG_OBJECTS_FREE
484 bool "Debug objects in freed memory"
485 depends on DEBUG_OBJECTS
486 help
487 This enables checks whether a k/v free operation frees an area
488 which contains an object which has not been deactivated
489 properly. This can make kmalloc/kfree-intensive workloads
490 much slower.
3ac7fe5a 491
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492config DEBUG_OBJECTS_TIMERS
493 bool "Debug timer objects"
494 depends on DEBUG_OBJECTS
495 help
496 If you say Y here, additional code will be inserted into the
497 timer routines to track the life time of timer objects and
498 validate the timer operations.
499
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500config DEBUG_OBJECTS_WORK
501 bool "Debug work objects"
502 depends on DEBUG_OBJECTS
503 help
504 If you say Y here, additional code will be inserted into the
505 work queue routines to track the life time of work objects and
506 validate the work operations.
507
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508config DEBUG_OBJECTS_RCU_HEAD
509 bool "Debug RCU callbacks objects"
fc2ecf7e 510 depends on DEBUG_OBJECTS
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511 help
512 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
513
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514config DEBUG_OBJECTS_PERCPU_COUNTER
515 bool "Debug percpu counter objects"
516 depends on DEBUG_OBJECTS
517 help
518 If you say Y here, additional code will be inserted into the
519 percpu counter routines to track the life time of percpu counter
520 objects and validate the percpu counter operations.
521
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522config DEBUG_OBJECTS_ENABLE_DEFAULT
523 int "debug_objects bootup default value (0-1)"
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524 range 0 1
525 default "1"
526 depends on DEBUG_OBJECTS
527 help
528 Debug objects boot parameter default value
3ae70205 529
1da177e4 530config DEBUG_SLAB
4a2f0acf 531 bool "Debug slab memory allocations"
4675ff05 532 depends on DEBUG_KERNEL && SLAB
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533 help
534 Say Y here to have the kernel do limited verification on memory
535 allocation as well as poisoning memory on free to catch use of freed
536 memory. This can make kmalloc/kfree-intensive workloads much slower.
537
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538config SLUB_DEBUG_ON
539 bool "SLUB debugging on by default"
4675ff05 540 depends on SLUB && SLUB_DEBUG
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541 default n
542 help
543 Boot with debugging on by default. SLUB boots by default with
544 the runtime debug capabilities switched off. Enabling this is
545 equivalent to specifying the "slub_debug" parameter on boot.
546 There is no support for more fine grained debug control like
547 possible with slub_debug=xxx. SLUB debugging may be switched
548 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
549 "slub_debug=-".
550
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551config SLUB_STATS
552 default n
553 bool "Enable SLUB performance statistics"
ab4d5ed5 554 depends on SLUB && SYSFS
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555 help
556 SLUB statistics are useful to debug SLUBs allocation behavior in
557 order find ways to optimize the allocator. This should never be
558 enabled for production use since keeping statistics slows down
559 the allocator by a few percentage points. The slabinfo command
560 supports the determination of the most active slabs to figure
561 out which slabs are relevant to a particular load.
562 Try running: slabinfo -DA
563
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564config HAVE_DEBUG_KMEMLEAK
565 bool
566
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567config DEBUG_KMEMLEAK
568 bool "Kernel memory leak detector"
525c1f92 569 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
79e0d9bd 570 select DEBUG_FS
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571 select STACKTRACE if STACKTRACE_SUPPORT
572 select KALLSYMS
b60e26a2 573 select CRC32
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574 help
575 Say Y here if you want to enable the memory leak
576 detector. The memory allocation/freeing is traced in a way
577 similar to the Boehm's conservative garbage collector, the
578 difference being that the orphan objects are not freed but
579 only shown in /sys/kernel/debug/kmemleak. Enabling this
580 feature will introduce an overhead to memory
700199b0 581 allocations. See Documentation/dev-tools/kmemleak.rst for more
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582 details.
583
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584 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
585 of finding leaks due to the slab objects poisoning.
586
587 In order to access the kmemleak file, debugfs needs to be
588 mounted (usually at /sys/kernel/debug).
589
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590config DEBUG_KMEMLEAK_MEM_POOL_SIZE
591 int "Kmemleak memory pool size"
0610c8a8 592 depends on DEBUG_KMEMLEAK
c59180ae 593 range 200 1000000
b751c52b 594 default 16000
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595 help
596 Kmemleak must track all the memory allocations to avoid
597 reporting false positives. Since memory may be allocated or
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598 freed before kmemleak is fully initialised, use a static pool
599 of metadata objects to track such callbacks. After kmemleak is
600 fully initialised, this memory pool acts as an emergency one
601 if slab allocations fail.
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602
603config DEBUG_KMEMLEAK_TEST
604 tristate "Simple test for the kernel memory leak detector"
605 depends on DEBUG_KMEMLEAK && m
606 help
607 This option enables a module that explicitly leaks memory.
608
609 If unsure, say N.
610
611config DEBUG_KMEMLEAK_DEFAULT_OFF
612 bool "Default kmemleak to off"
613 depends on DEBUG_KMEMLEAK
614 help
615 Say Y here to disable kmemleak by default. It can then be enabled
616 on the command line via kmemleak=on.
617
d53ce042
SK
618config DEBUG_KMEMLEAK_AUTO_SCAN
619 bool "Enable kmemleak auto scan thread on boot up"
620 default y
621 depends on DEBUG_KMEMLEAK
622 help
623 Depending on the cpu, kmemleak scan may be cpu intensive and can
624 stall user tasks at times. This option enables/disables automatic
625 kmemleak scan at boot up.
626
627 Say N here to disable kmemleak auto scan thread to stop automatic
628 scanning. Disabling this option disables automatic reporting of
629 memory leaks.
630
631 If unsure, say Y.
632
0610c8a8
DH
633config DEBUG_STACK_USAGE
634 bool "Stack utilization instrumentation"
6c31da34 635 depends on DEBUG_KERNEL && !IA64
0610c8a8
DH
636 help
637 Enables the display of the minimum amount of free stack which each
638 task has ever had available in the sysrq-T and sysrq-P debug output.
639
640 This option will slow down process creation somewhat.
641
dc9b9638
CD
642config SCHED_STACK_END_CHECK
643 bool "Detect stack corruption on calls to schedule()"
644 depends on DEBUG_KERNEL
645 default n
646 help
647 This option checks for a stack overrun on calls to schedule().
648 If the stack end location is found to be over written always panic as
649 the content of the corrupted region can no longer be trusted.
650 This is to ensure no erroneous behaviour occurs which could result in
651 data corruption or a sporadic crash at a later stage once the region
652 is examined. The runtime overhead introduced is minimal.
653
0610c8a8
DH
654config DEBUG_VM
655 bool "Debug VM"
656 depends on DEBUG_KERNEL
657 help
658 Enable this to turn on extended checks in the virtual-memory system
68d4b3df 659 that may impact performance.
0610c8a8
DH
660
661 If unsure, say N.
662
4f115147
DB
663config DEBUG_VM_VMACACHE
664 bool "Debug VMA caching"
665 depends on DEBUG_VM
666 help
667 Enable this to turn on VMA caching debug information. Doing so
668 can cause significant overhead, so only enable it in non-production
669 environments.
670
671 If unsure, say N.
672
0610c8a8
DH
673config DEBUG_VM_RB
674 bool "Debug VM red-black trees"
675 depends on DEBUG_VM
676 help
a663dad6 677 Enable VM red-black tree debugging information and extra validations.
0610c8a8
DH
678
679 If unsure, say N.
680
95ad9755
KS
681config DEBUG_VM_PGFLAGS
682 bool "Debug page-flags operations"
683 depends on DEBUG_VM
684 help
685 Enables extra validation on page flags operations.
686
687 If unsure, say N.
688
fa5b6ec9
LA
689config ARCH_HAS_DEBUG_VIRTUAL
690 bool
691
0610c8a8
DH
692config DEBUG_VIRTUAL
693 bool "Debug VM translations"
fa5b6ec9 694 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
0610c8a8
DH
695 help
696 Enable some costly sanity checks in virtual to page code. This can
697 catch mistakes with virt_to_page() and friends.
698
699 If unsure, say N.
700
701config DEBUG_NOMMU_REGIONS
702 bool "Debug the global anon/private NOMMU mapping region tree"
703 depends on DEBUG_KERNEL && !MMU
704 help
705 This option causes the global tree of anonymous and private mapping
706 regions to be regularly checked for invalid topology.
707
708config DEBUG_MEMORY_INIT
709 bool "Debug memory initialisation" if EXPERT
710 default !EXPERT
711 help
712 Enable this for additional checks during memory initialisation.
713 The sanity checks verify aspects of the VM such as the memory model
714 and other information provided by the architecture. Verbose
715 information will be printed at KERN_DEBUG loglevel depending
716 on the mminit_loglevel= command-line option.
717
718 If unsure, say Y
719
720config MEMORY_NOTIFIER_ERROR_INJECT
721 tristate "Memory hotplug notifier error injection module"
722 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
723 help
724 This option provides the ability to inject artificial errors to
725 memory hotplug notifier chain callbacks. It is controlled through
726 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
727
728 If the notifier call chain should be failed with some events
729 notified, write the error code to "actions/<notifier event>/error".
730
731 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
732
733 # cd /sys/kernel/debug/notifier-error-inject/memory
734 # echo -12 > actions/MEM_GOING_OFFLINE/error
735 # echo offline > /sys/devices/system/memory/memoryXXX/state
736 bash: echo: write error: Cannot allocate memory
737
738 To compile this code as a module, choose M here: the module will
739 be called memory-notifier-error-inject.
740
741 If unsure, say N.
742
743config DEBUG_PER_CPU_MAPS
744 bool "Debug access to per_cpu maps"
745 depends on DEBUG_KERNEL
746 depends on SMP
747 help
748 Say Y to verify that the per_cpu map being accessed has
749 been set up. This adds a fair amount of code to kernel memory
750 and decreases performance.
751
752 Say N if unsure.
753
754config DEBUG_HIGHMEM
755 bool "Highmem debugging"
756 depends on DEBUG_KERNEL && HIGHMEM
757 help
b1357c9f
GU
758 This option enables additional error checking for high memory
759 systems. Disable for production systems.
0610c8a8
DH
760
761config HAVE_DEBUG_STACKOVERFLOW
762 bool
763
764config DEBUG_STACKOVERFLOW
765 bool "Check for stack overflows"
766 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
767 ---help---
768 Say Y here if you want to check for overflows of kernel, IRQ
edb0ec07 769 and exception stacks (if your architecture uses them). This
0610c8a8
DH
770 option will show detailed messages if free stack space drops
771 below a certain limit.
772
773 These kinds of bugs usually occur when call-chains in the
774 kernel get too deep, especially when interrupts are
775 involved.
776
777 Use this in cases where you see apparently random memory
778 corruption, especially if it appears in 'struct thread_info'
779
780 If in doubt, say "N".
781
0b24becc
AR
782source "lib/Kconfig.kasan"
783
0610c8a8
DH
784endmenu # "Memory Debugging"
785
a304e1b8
DW
786config DEBUG_SHIRQ
787 bool "Debug shared IRQ handlers"
0244ad00 788 depends on DEBUG_KERNEL
a304e1b8
DW
789 help
790 Enable this to generate a spurious interrupt as soon as a shared
791 interrupt handler is registered, and just before one is deregistered.
792 Drivers ought to be able to handle interrupts coming in at those
793 points; some don't and need to be caught.
794
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CD
795menu "Debug Oops, Lockups and Hangs"
796
797config PANIC_ON_OOPS
798 bool "Panic on Oops"
799 help
800 Say Y here to enable the kernel to panic when it oopses. This
801 has the same effect as setting oops=panic on the kernel command
802 line.
803
804 This feature is useful to ensure that the kernel does not do
805 anything erroneous after an oops which could result in data
806 corruption or other issues.
807
808 Say N if unsure.
809
810config PANIC_ON_OOPS_VALUE
811 int
812 range 0 1
813 default 0 if !PANIC_ON_OOPS
814 default 1 if PANIC_ON_OOPS
815
816config PANIC_TIMEOUT
817 int "panic timeout"
818 default 0
819 help
820 Set the timeout value (in seconds) until a reboot occurs when the
821 the kernel panics. If n = 0, then we wait forever. A timeout
822 value n > 0 will wait n seconds before rebooting, while a timeout
823 value n < 0 will reboot immediately.
92aef8fb 824
58687acb 825config LOCKUP_DETECTOR
05a4a952
NP
826 bool
827
828config SOFTLOCKUP_DETECTOR
829 bool "Detect Soft Lockups"
dea20a3f 830 depends on DEBUG_KERNEL && !S390
05a4a952 831 select LOCKUP_DETECTOR
8446f1d3 832 help
58687acb 833 Say Y here to enable the kernel to act as a watchdog to detect
05a4a952 834 soft lockups.
58687acb
DZ
835
836 Softlockups are bugs that cause the kernel to loop in kernel
5f329089 837 mode for more than 20 seconds, without giving other tasks a
58687acb
DZ
838 chance to run. The current stack trace is displayed upon
839 detection and the system will stay locked up.
8446f1d3 840
5f00ae0d
RD
841config BOOTPARAM_SOFTLOCKUP_PANIC
842 bool "Panic (Reboot) On Soft Lockups"
843 depends on SOFTLOCKUP_DETECTOR
844 help
845 Say Y here to enable the kernel to panic on "soft lockups",
846 which are bugs that cause the kernel to loop in kernel
847 mode for more than 20 seconds (configurable using the watchdog_thresh
848 sysctl), without giving other tasks a chance to run.
849
850 The panic can be used in combination with panic_timeout,
851 to cause the system to reboot automatically after a
852 lockup has been detected. This feature is useful for
853 high-availability systems that have uptime guarantees and
854 where a lockup must be resolved ASAP.
855
856 Say N if unsure.
857
858config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
859 int
860 depends on SOFTLOCKUP_DETECTOR
861 range 0 1
862 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
863 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
864
05a4a952
NP
865config HARDLOCKUP_DETECTOR_PERF
866 bool
867 select SOFTLOCKUP_DETECTOR
868
7edaeb68
TG
869#
870# Enables a timestamp based low pass filter to compensate for perf based
871# hard lockup detection which runs too fast due to turbo modes.
872#
873config HARDLOCKUP_CHECK_TIMESTAMP
874 bool
875
05a4a952
NP
876#
877# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
878# lockup detector rather than the perf based detector.
879#
880config HARDLOCKUP_DETECTOR
881 bool "Detect Hard Lockups"
882 depends on DEBUG_KERNEL && !S390
883 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
884 select LOCKUP_DETECTOR
885 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
886 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
887 help
888 Say Y here to enable the kernel to act as a watchdog to detect
889 hard lockups.
890
58687acb 891 Hardlockups are bugs that cause the CPU to loop in kernel mode
5f329089 892 for more than 10 seconds, without letting other interrupts have a
58687acb
DZ
893 chance to run. The current stack trace is displayed upon detection
894 and the system will stay locked up.
8446f1d3 895
fef2c9bc
DZ
896config BOOTPARAM_HARDLOCKUP_PANIC
897 bool "Panic (Reboot) On Hard Lockups"
8f1f66ed 898 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
899 help
900 Say Y here to enable the kernel to panic on "hard lockups",
901 which are bugs that cause the kernel to loop in kernel
5f329089
FLVC
902 mode with interrupts disabled for more than 10 seconds (configurable
903 using the watchdog_thresh sysctl).
fef2c9bc
DZ
904
905 Say N if unsure.
906
907config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
908 int
8f1f66ed 909 depends on HARDLOCKUP_DETECTOR
fef2c9bc
DZ
910 range 0 1
911 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
912 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
913
e162b39a
MSB
914config DETECT_HUNG_TASK
915 bool "Detect Hung Tasks"
916 depends on DEBUG_KERNEL
05a4a952 917 default SOFTLOCKUP_DETECTOR
e162b39a 918 help
0610c8a8
DH
919 Say Y here to enable the kernel to detect "hung tasks",
920 which are bugs that cause the task to be stuck in
96b03ab8 921 uninterruptible "D" state indefinitely.
1da177e4 922
0610c8a8
DH
923 When a hung task is detected, the kernel will print the
924 current stack trace (which you should report), but the
925 task will stay in uninterruptible state. If lockdep is
926 enabled then all held locks will also be reported. This
927 feature has negligible overhead.
871751e2 928
0610c8a8
DH
929config DEFAULT_HUNG_TASK_TIMEOUT
930 int "Default timeout for hung task detection (in seconds)"
931 depends on DETECT_HUNG_TASK
932 default 120
f0630fff 933 help
0610c8a8
DH
934 This option controls the default timeout (in seconds) used
935 to determine when a task has become non-responsive and should
936 be considered hung.
f0630fff 937
0610c8a8
DH
938 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
939 sysctl or by writing a value to
940 /proc/sys/kernel/hung_task_timeout_secs.
8ff12cfc 941
0610c8a8
DH
942 A timeout of 0 disables the check. The default is two minutes.
943 Keeping the default should be fine in most cases.
b69ec42b 944
0610c8a8
DH
945config BOOTPARAM_HUNG_TASK_PANIC
946 bool "Panic (Reboot) On Hung Tasks"
947 depends on DETECT_HUNG_TASK
3bba00d7 948 help
0610c8a8
DH
949 Say Y here to enable the kernel to panic on "hung tasks",
950 which are bugs that cause the kernel to leave a task stuck
951 in uninterruptible "D" state.
3bba00d7 952
0610c8a8
DH
953 The panic can be used in combination with panic_timeout,
954 to cause the system to reboot automatically after a
955 hung task has been detected. This feature is useful for
956 high-availability systems that have uptime guarantees and
957 where a hung tasks must be resolved ASAP.
bf96d1e3 958
0610c8a8 959 Say N if unsure.
bf96d1e3 960
0610c8a8
DH
961config BOOTPARAM_HUNG_TASK_PANIC_VALUE
962 int
963 depends on DETECT_HUNG_TASK
964 range 0 1
965 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
966 default 1 if BOOTPARAM_HUNG_TASK_PANIC
3bba00d7 967
82607adc
TH
968config WQ_WATCHDOG
969 bool "Detect Workqueue Stalls"
970 depends on DEBUG_KERNEL
971 help
972 Say Y here to enable stall detection on workqueues. If a
973 worker pool doesn't make forward progress on a pending work
974 item for over a given amount of time, 30s by default, a
975 warning message is printed along with dump of workqueue
976 state. This can be configured through kernel parameter
977 "workqueue.watchdog_thresh" and its sysfs counterpart.
978
30428ef5
KK
979config TEST_LOCKUP
980 tristate "Test module to generate lockups"
981 help
982 This builds the "test_lockup" module that helps to make sure
983 that watchdogs and lockup detectors are working properly.
984
985 Depending on module parameters it could emulate soft or hard
986 lockup, "hung task", or locking arbitrary lock for a long time.
987 Also it could generate series of lockups with cooling-down periods.
988
989 If unsure, say N.
990
92aef8fb
DH
991endmenu # "Debug lockups and hangs"
992
ebebdd09 993menu "Scheduler Debugging"
5800dc3c 994
0610c8a8
DH
995config SCHED_DEBUG
996 bool "Collect scheduler debugging info"
997 depends on DEBUG_KERNEL && PROC_FS
998 default y
0822ee4a 999 help
0610c8a8
DH
1000 If you say Y here, the /proc/sched_debug file will be provided
1001 that can help debug the scheduler. The runtime overhead of this
1002 option is minimal.
0822ee4a 1003
f6db8347
NR
1004config SCHED_INFO
1005 bool
1006 default n
1007
0610c8a8
DH
1008config SCHEDSTATS
1009 bool "Collect scheduler statistics"
1010 depends on DEBUG_KERNEL && PROC_FS
f6db8347 1011 select SCHED_INFO
0610c8a8
DH
1012 help
1013 If you say Y here, additional code will be inserted into the
1014 scheduler and related routines to collect statistics about
1015 scheduler behavior and provide them in /proc/schedstat. These
1016 stats may be useful for both tuning and debugging the scheduler
1017 If you aren't debugging the scheduler or trying to tune a specific
1018 application, you can say N to avoid the very slight overhead
1019 this adds.
0822ee4a 1020
ebebdd09 1021endmenu
0d9e2632 1022
3c17ad19
JS
1023config DEBUG_TIMEKEEPING
1024 bool "Enable extra timekeeping sanity checking"
1025 help
1026 This option will enable additional timekeeping sanity checks
1027 which may be helpful when diagnosing issues where timekeeping
1028 problems are suspected.
1029
1030 This may include checks in the timekeeping hotpaths, so this
1031 option may have a (very small) performance impact to some
1032 workloads.
1033
1034 If unsure, say N.
1035
1da177e4
LT
1036config DEBUG_PREEMPT
1037 bool "Debug preemptible kernel"
9f472869 1038 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1da177e4
LT
1039 default y
1040 help
1041 If you say Y here then the kernel will use a debug variant of the
1042 commonly used smp_processor_id() function and will print warnings
1043 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1044 will detect preemption count underflows.
1045
9eade16b
DH
1046menu "Lock Debugging (spinlocks, mutexes, etc...)"
1047
f07cbebb
WL
1048config LOCK_DEBUGGING_SUPPORT
1049 bool
1050 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1051 default y
1052
19193bca
WL
1053config PROVE_LOCKING
1054 bool "Lock debugging: prove locking correctness"
1055 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1056 select LOCKDEP
1057 select DEBUG_SPINLOCK
1058 select DEBUG_MUTEXES
1059 select DEBUG_RT_MUTEXES if RT_MUTEXES
c71fd893 1060 select DEBUG_RWSEMS
19193bca
WL
1061 select DEBUG_WW_MUTEX_SLOWPATH
1062 select DEBUG_LOCK_ALLOC
1063 select TRACE_IRQFLAGS
1064 default n
1065 help
1066 This feature enables the kernel to prove that all locking
1067 that occurs in the kernel runtime is mathematically
1068 correct: that under no circumstance could an arbitrary (and
1069 not yet triggered) combination of observed locking
1070 sequences (on an arbitrary number of CPUs, running an
1071 arbitrary number of tasks and interrupt contexts) cause a
1072 deadlock.
1073
1074 In short, this feature enables the kernel to report locking
1075 related deadlocks before they actually occur.
1076
1077 The proof does not depend on how hard and complex a
1078 deadlock scenario would be to trigger: how many
1079 participant CPUs, tasks and irq-contexts would be needed
1080 for it to trigger. The proof also does not depend on
1081 timing: if a race and a resulting deadlock is possible
1082 theoretically (no matter how unlikely the race scenario
1083 is), it will be proven so and will immediately be
1084 reported by the kernel (once the event is observed that
1085 makes the deadlock theoretically possible).
1086
1087 If a deadlock is impossible (i.e. the locking rules, as
1088 observed by the kernel, are mathematically correct), the
1089 kernel reports nothing.
1090
1091 NOTE: this feature can also be enabled for rwlocks, mutexes
1092 and rwsems - in which case all dependencies between these
1093 different locking variants are observed and mapped too, and
1094 the proof of observed correctness is also maintained for an
1095 arbitrary combination of these separate locking variants.
1096
387b1468 1097 For more details, see Documentation/locking/lockdep-design.rst.
19193bca 1098
de8f5e4f
PZ
1099config PROVE_RAW_LOCK_NESTING
1100 bool "Enable raw_spinlock - spinlock nesting checks"
1101 depends on PROVE_LOCKING
1102 default n
1103 help
1104 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1105 that the lock nesting rules for PREEMPT_RT enabled kernels are
1106 not violated.
1107
1108 NOTE: There are known nesting problems. So if you enable this
1109 option expect lockdep splats until these problems have been fully
1110 addressed which is work in progress. This config switch allows to
1111 identify and analyze these problems. It will be removed and the
1112 check permanentely enabled once the main issues have been fixed.
1113
1114 If unsure, select N.
1115
19193bca
WL
1116config LOCK_STAT
1117 bool "Lock usage statistics"
1118 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1119 select LOCKDEP
1120 select DEBUG_SPINLOCK
1121 select DEBUG_MUTEXES
1122 select DEBUG_RT_MUTEXES if RT_MUTEXES
1123 select DEBUG_LOCK_ALLOC
1124 default n
1125 help
1126 This feature enables tracking lock contention points
1127
387b1468 1128 For more details, see Documentation/locking/lockstat.rst
19193bca
WL
1129
1130 This also enables lock events required by "perf lock",
1131 subcommand of perf.
1132 If you want to use "perf lock", you also need to turn on
1133 CONFIG_EVENT_TRACING.
1134
1135 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1136 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1137
e7eebaf6
IM
1138config DEBUG_RT_MUTEXES
1139 bool "RT Mutex debugging, deadlock detection"
e7eebaf6
IM
1140 depends on DEBUG_KERNEL && RT_MUTEXES
1141 help
1142 This allows rt mutex semantics violations and rt mutex related
1143 deadlocks (lockups) to be detected and reported automatically.
1144
1da177e4 1145config DEBUG_SPINLOCK
4d9f34ad 1146 bool "Spinlock and rw-lock debugging: basic checks"
1da177e4 1147 depends on DEBUG_KERNEL
e335e3eb 1148 select UNINLINE_SPIN_UNLOCK
1da177e4
LT
1149 help
1150 Say Y here and build SMP to catch missing spinlock initialization
1151 and certain other kinds of spinlock errors commonly made. This is
1152 best used in conjunction with the NMI watchdog so that spinlock
1153 deadlocks are also debuggable.
1154
4d9f34ad
IM
1155config DEBUG_MUTEXES
1156 bool "Mutex debugging: basic checks"
1157 depends on DEBUG_KERNEL
1158 help
1159 This feature allows mutex semantics violations to be detected and
1160 reported.
1161
23010027
DV
1162config DEBUG_WW_MUTEX_SLOWPATH
1163 bool "Wait/wound mutex debugging: Slowpath testing"
f07cbebb 1164 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
23010027
DV
1165 select DEBUG_LOCK_ALLOC
1166 select DEBUG_SPINLOCK
1167 select DEBUG_MUTEXES
1168 help
1169 This feature enables slowpath testing for w/w mutex users by
1170 injecting additional -EDEADLK wound/backoff cases. Together with
1171 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1172 will test all possible w/w mutex interface abuse with the
1173 exception of simply not acquiring all the required locks.
4d692373
RC
1174 Note that this feature can introduce significant overhead, so
1175 it really should not be enabled in a production or distro kernel,
1176 even a debug kernel. If you are a driver writer, enable it. If
1177 you are a distro, do not.
23010027 1178
5149cbac
WL
1179config DEBUG_RWSEMS
1180 bool "RW Semaphore debugging: basic checks"
c71fd893 1181 depends on DEBUG_KERNEL
5149cbac 1182 help
c71fd893
WL
1183 This debugging feature allows mismatched rw semaphore locks
1184 and unlocks to be detected and reported.
5149cbac 1185
4d9f34ad
IM
1186config DEBUG_LOCK_ALLOC
1187 bool "Lock debugging: detect incorrect freeing of live locks"
f07cbebb 1188 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad
IM
1189 select DEBUG_SPINLOCK
1190 select DEBUG_MUTEXES
f5694788 1191 select DEBUG_RT_MUTEXES if RT_MUTEXES
4d9f34ad
IM
1192 select LOCKDEP
1193 help
1194 This feature will check whether any held lock (spinlock, rwlock,
1195 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1196 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1197 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1198 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1199 held during task exit.
1200
4d9f34ad
IM
1201config LOCKDEP
1202 bool
f07cbebb 1203 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
4d9f34ad 1204 select STACKTRACE
f9b58e8c 1205 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
4d9f34ad
IM
1206 select KALLSYMS
1207 select KALLSYMS_ALL
1208
395102db
DJ
1209config LOCKDEP_SMALL
1210 bool
1211
4d9f34ad
IM
1212config DEBUG_LOCKDEP
1213 bool "Lock dependency engine debugging"
517e7aa5 1214 depends on DEBUG_KERNEL && LOCKDEP
4d9f34ad
IM
1215 help
1216 If you say Y here, the lock dependency engine will do
1217 additional runtime checks to debug itself, at the price
1218 of more runtime overhead.
1219
d902db1e
FW
1220config DEBUG_ATOMIC_SLEEP
1221 bool "Sleep inside atomic section checking"
e8f7c70f 1222 select PREEMPT_COUNT
1da177e4 1223 depends on DEBUG_KERNEL
87a4c375 1224 depends on !ARCH_NO_PREEMPT
1da177e4
LT
1225 help
1226 If you say Y here, various routines which may sleep will become very
d902db1e
FW
1227 noisy if they are called inside atomic sections: when a spinlock is
1228 held, inside an rcu read side critical section, inside preempt disabled
1229 sections, inside an interrupt, etc...
1da177e4 1230
cae2ed9a
IM
1231config DEBUG_LOCKING_API_SELFTESTS
1232 bool "Locking API boot-time self-tests"
1233 depends on DEBUG_KERNEL
1234 help
1235 Say Y here if you want the kernel to run a short self-test during
1236 bootup. The self-test checks whether common types of locking bugs
1237 are detected by debugging mechanisms or not. (if you disable
1238 lock debugging then those bugs wont be detected of course.)
1239 The following locking APIs are covered: spinlocks, rwlocks,
1240 mutexes and rwsems.
1241
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PM
1242config LOCK_TORTURE_TEST
1243 tristate "torture tests for locking"
1244 depends on DEBUG_KERNEL
1245 select TORTURE_TEST
0af3fe1e
PM
1246 help
1247 This option provides a kernel module that runs torture tests
1248 on kernel locking primitives. The kernel module may be built
1249 after the fact on the running kernel to be tested, if desired.
1250
1251 Say Y here if you want kernel locking-primitive torture tests
1252 to be built into the kernel.
1253 Say M if you want these torture tests to build as a module.
1254 Say N if you are unsure.
1255
f2a5fec1
CW
1256config WW_MUTEX_SELFTEST
1257 tristate "Wait/wound mutex selftests"
1258 help
1259 This option provides a kernel module that runs tests on the
1260 on the struct ww_mutex locking API.
1261
1262 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1263 with this test harness.
1264
1265 Say M if you want these self tests to build as a module.
1266 Say N if you are unsure.
1267
9eade16b 1268endmenu # lock debugging
8637c099 1269
9eade16b
DH
1270config TRACE_IRQFLAGS
1271 bool
5ca43f6c 1272 help
9eade16b
DH
1273 Enables hooks to interrupt enabling and disabling for
1274 either tracing or lock debugging.
5ca43f6c 1275
8637c099 1276config STACKTRACE
0c38e1fe 1277 bool "Stack backtrace support"
8637c099 1278 depends on STACKTRACE_SUPPORT
0c38e1fe
DJ
1279 help
1280 This option causes the kernel to create a /proc/pid/stack for
1281 every process, showing its current stack trace.
1282 It is also used by various kernel debugging features that require
1283 stack trace generation.
5ca43f6c 1284
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TT
1285config WARN_ALL_UNSEEDED_RANDOM
1286 bool "Warn for all uses of unseeded randomness"
1287 default n
d06bfd19
JD
1288 help
1289 Some parts of the kernel contain bugs relating to their use of
1290 cryptographically secure random numbers before it's actually possible
1291 to generate those numbers securely. This setting ensures that these
1292 flaws don't go unnoticed, by enabling a message, should this ever
1293 occur. This will allow people with obscure setups to know when things
1294 are going wrong, so that they might contact developers about fixing
1295 it.
1296
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TT
1297 Unfortunately, on some models of some architectures getting
1298 a fully seeded CRNG is extremely difficult, and so this can
1299 result in dmesg getting spammed for a surprisingly long
1300 time. This is really bad from a security perspective, and
1301 so architecture maintainers really need to do what they can
1302 to get the CRNG seeded sooner after the system is booted.
4c5d114e 1303 However, since users cannot do anything actionable to
eecabf56
TT
1304 address this, by default the kernel will issue only a single
1305 warning for the first use of unseeded randomness.
1306
1307 Say Y here if you want to receive warnings for all uses of
1308 unseeded randomness. This will be of use primarily for
4c5d114e 1309 those developers interested in improving the security of
eecabf56
TT
1310 Linux kernels running on their architecture (or
1311 subarchitecture).
d06bfd19 1312
1da177e4
LT
1313config DEBUG_KOBJECT
1314 bool "kobject debugging"
1315 depends on DEBUG_KERNEL
1316 help
1317 If you say Y here, some extra kobject debugging messages will be sent
aca52c39 1318 to the syslog.
1da177e4 1319
c817a67e
RK
1320config DEBUG_KOBJECT_RELEASE
1321 bool "kobject release debugging"
2a999aa0 1322 depends on DEBUG_OBJECTS_TIMERS
c817a67e
RK
1323 help
1324 kobjects are reference counted objects. This means that their
1325 last reference count put is not predictable, and the kobject can
1326 live on past the point at which a driver decides to drop it's
1327 initial reference to the kobject gained on allocation. An
1328 example of this would be a struct device which has just been
1329 unregistered.
1330
1331 However, some buggy drivers assume that after such an operation,
1332 the memory backing the kobject can be immediately freed. This
1333 goes completely against the principles of a refcounted object.
1334
1335 If you say Y here, the kernel will delay the release of kobjects
1336 on the last reference count to improve the visibility of this
1337 kind of kobject release bug.
1338
9b2a60c4
CM
1339config HAVE_DEBUG_BUGVERBOSE
1340 bool
1341
3be5cbcd 1342menu "Debug kernel data structures"
1da177e4 1343
199a9afc
DJ
1344config DEBUG_LIST
1345 bool "Debug linked list manipulation"
4520bcb2 1346 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
199a9afc
DJ
1347 help
1348 Enable this to turn on extended checks in the linked-list
1349 walking routines.
1350
1351 If unsure, say N.
1352
8e18faea 1353config DEBUG_PLIST
b8cfff68
DS
1354 bool "Debug priority linked list manipulation"
1355 depends on DEBUG_KERNEL
1356 help
1357 Enable this to turn on extended checks in the priority-ordered
1358 linked-list (plist) walking routines. This checks the entire
1359 list multiple times during each manipulation.
1360
1361 If unsure, say N.
1362
d6ec0842
JA
1363config DEBUG_SG
1364 bool "Debug SG table operations"
1365 depends on DEBUG_KERNEL
1366 help
1367 Enable this to turn on checks on scatter-gather tables. This can
1368 help find problems with drivers that do not properly initialize
1369 their sg tables.
1370
1371 If unsure, say N.
1372
1b2439db
AV
1373config DEBUG_NOTIFIERS
1374 bool "Debug notifier call chains"
1375 depends on DEBUG_KERNEL
1376 help
1377 Enable this to turn on sanity checking for notifier call chains.
1378 This is most useful for kernel developers to make sure that
1379 modules properly unregister themselves from notifier chains.
1380 This is a relatively cheap check but if you care about maximum
1381 performance, say N.
1382
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1383config BUG_ON_DATA_CORRUPTION
1384 bool "Trigger a BUG when data corruption is detected"
1385 select DEBUG_LIST
1386 help
1387 Select this option if the kernel should BUG when it encounters
1388 data corruption in kernel memory structures when they get checked
1389 for validity.
1390
1391 If unsure, say N.
1392
1393endmenu
1394
e0e81739
DH
1395config DEBUG_CREDENTIALS
1396 bool "Debug credential management"
1397 depends on DEBUG_KERNEL
1398 help
1399 Enable this to turn on some debug checking for credential
1400 management. The additional code keeps track of the number of
1401 pointers from task_structs to any given cred struct, and checks to
1402 see that this number never exceeds the usage count of the cred
1403 struct.
1404
1405 Furthermore, if SELinux is enabled, this also checks that the
1406 security pointer in the cred struct is never seen to be invalid.
1407
1408 If unsure, say N.
1409
43a0a2a7 1410source "kernel/rcu/Kconfig.debug"
2f03e3ca 1411
f303fccb
TH
1412config DEBUG_WQ_FORCE_RR_CPU
1413 bool "Force round-robin CPU selection for unbound work items"
1414 depends on DEBUG_KERNEL
1415 default n
1416 help
1417 Workqueue used to implicitly guarantee that work items queued
1418 without explicit CPU specified are put on the local CPU. This
1419 guarantee is no longer true and while local CPU is still
1420 preferred work items may be put on foreign CPUs. Kernel
1421 parameter "workqueue.debug_force_rr_cpu" is added to force
1422 round-robin CPU selection to flush out usages which depend on the
1423 now broken guarantee. This config option enables the debug
1424 feature by default. When enabled, memory and cache locality will
1425 be impacted.
1426
870d6656 1427config DEBUG_BLOCK_EXT_DEVT
68d4b3df 1428 bool "Force extended block device numbers and spread them"
870d6656
TH
1429 depends on DEBUG_KERNEL
1430 depends on BLOCK
759f8ca3 1431 default n
870d6656 1432 help
0e11e342
TH
1433 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1434 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1435 YOU ARE DOING. Distros, please enable this and fix whatever
1436 is broken.
1437
870d6656
TH
1438 Conventionally, block device numbers are allocated from
1439 predetermined contiguous area. However, extended block area
1440 may introduce non-contiguous block device numbers. This
1441 option forces most block device numbers to be allocated from
1442 the extended space and spreads them to discover kernel or
1443 userland code paths which assume predetermined contiguous
1444 device number allocation.
1445
55dc7db7
TH
1446 Note that turning on this debug option shuffles all the
1447 device numbers for all IDE and SCSI devices including libata
1448 ones, so root partition specified using device number
1449 directly (via rdev or root=MAJ:MIN) won't work anymore.
1450 Textual device names (root=/dev/sdXn) will continue to work.
1451
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TH
1452 Say N if you are unsure.
1453
757c989b
TG
1454config CPU_HOTPLUG_STATE_CONTROL
1455 bool "Enable CPU hotplug state control"
1456 depends on DEBUG_KERNEL
1457 depends on HOTPLUG_CPU
1458 default n
1459 help
1460 Allows to write steps between "offline" and "online" to the CPUs
1461 sysfs target file so states can be stepped granular. This is a debug
1462 option for now as the hotplug machinery cannot be stopped and
1463 restarted at arbitrary points yet.
1464
1465 Say N if your are unsure.
1466
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1467config LATENCYTOP
1468 bool "Latency measuring infrastructure"
1469 depends on DEBUG_KERNEL
1470 depends on STACKTRACE_SUPPORT
1471 depends on PROC_FS
1472 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1473 select KALLSYMS
1474 select KALLSYMS_ALL
1475 select STACKTRACE
1476 select SCHEDSTATS
1477 select SCHED_DEBUG
1478 help
1479 Enable this option if you want to use the LatencyTOP tool
1480 to find out which userspace is blocking on what kernel operations.
1481
1482source "kernel/trace/Kconfig"
1483
1484config PROVIDE_OHCI1394_DMA_INIT
1485 bool "Remote debugging over FireWire early on boot"
1486 depends on PCI && X86
1487 help
1488 If you want to debug problems which hang or crash the kernel early
1489 on boot and the crashing machine has a FireWire port, you can use
1490 this feature to remotely access the memory of the crashed machine
1491 over FireWire. This employs remote DMA as part of the OHCI1394
1492 specification which is now the standard for FireWire controllers.
1493
1494 With remote DMA, you can monitor the printk buffer remotely using
1495 firescope and access all memory below 4GB using fireproxy from gdb.
1496 Even controlling a kernel debugger is possible using remote DMA.
1497
1498 Usage:
1499
1500 If ohci1394_dma=early is used as boot parameter, it will initialize
1501 all OHCI1394 controllers which are found in the PCI config space.
1502
1503 As all changes to the FireWire bus such as enabling and disabling
1504 devices cause a bus reset and thereby disable remote DMA for all
1505 devices, be sure to have the cable plugged and FireWire enabled on
1506 the debugging host before booting the debug target for debugging.
1507
1508 This code (~1k) is freed after boot. By then, the firewire stack
1509 in charge of the OHCI-1394 controllers should be used instead.
1510
1511 See Documentation/debugging-via-ohci1394.txt for more information.
1512
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CD
1513source "samples/Kconfig"
1514
1515config ARCH_HAS_DEVMEM_IS_ALLOWED
1516 bool
1517
1518config STRICT_DEVMEM
1519 bool "Filter access to /dev/mem"
1520 depends on MMU && DEVMEM
1521 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1522 default y if PPC || X86 || ARM64
1523 help
1524 If this option is disabled, you allow userspace (root) access to all
1525 of memory, including kernel and userspace memory. Accidental
1526 access to this is obviously disastrous, but specific access can
1527 be used by people debugging the kernel. Note that with PAT support
1528 enabled, even in this case there are restrictions on /dev/mem
1529 use due to the cache aliasing requirements.
1530
1531 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1532 file only allows userspace access to PCI space and the BIOS code and
1533 data regions. This is sufficient for dosemu and X and all common
1534 users of /dev/mem.
1535
1536 If in doubt, say Y.
1537
1538config IO_STRICT_DEVMEM
1539 bool "Filter I/O access to /dev/mem"
1540 depends on STRICT_DEVMEM
1541 help
1542 If this option is disabled, you allow userspace (root) access to all
1543 io-memory regardless of whether a driver is actively using that
1544 range. Accidental access to this is obviously disastrous, but
1545 specific access can be used by people debugging kernel drivers.
1546
1547 If this option is switched on, the /dev/mem file only allows
1548 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1549 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1550 if the driver using a given range cannot be disabled.
1551
1552 If in doubt, say Y.
1553
1554menu "$(SRCARCH) Debugging"
1555
1556source "arch/$(SRCARCH)/Kconfig.debug"
1557
1558endmenu
1559
1560menu "Kernel Testing and Coverage"
1561
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CD
1562source "lib/kunit/Kconfig"
1563
8d438288
AM
1564config NOTIFIER_ERROR_INJECTION
1565 tristate "Notifier error injection"
1566 depends on DEBUG_KERNEL
1567 select DEBUG_FS
1568 help
e41e85cc 1569 This option provides the ability to inject artificial errors to
8d438288
AM
1570 specified notifier chain callbacks. It is useful to test the error
1571 handling of notifier call chain failures.
1572
1573 Say N if unsure.
1574
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AM
1575config PM_NOTIFIER_ERROR_INJECT
1576 tristate "PM notifier error injection module"
1577 depends on PM && NOTIFIER_ERROR_INJECTION
1578 default m if PM_DEBUG
1579 help
e41e85cc 1580 This option provides the ability to inject artificial errors to
048b9c35
AM
1581 PM notifier chain callbacks. It is controlled through debugfs
1582 interface /sys/kernel/debug/notifier-error-inject/pm
1583
1584 If the notifier call chain should be failed with some events
1585 notified, write the error code to "actions/<notifier event>/error".
1586
1587 Example: Inject PM suspend error (-12 = -ENOMEM)
1588
1589 # cd /sys/kernel/debug/notifier-error-inject/pm/
1590 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1591 # echo mem > /sys/power/state
1592 bash: echo: write error: Cannot allocate memory
1593
1594 To compile this code as a module, choose M here: the module will
1595 be called pm-notifier-error-inject.
1596
1597 If unsure, say N.
1598
d526e85f
BH
1599config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1600 tristate "OF reconfig notifier error injection module"
1601 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
08dfb4dd 1602 help
e41e85cc 1603 This option provides the ability to inject artificial errors to
d526e85f 1604 OF reconfig notifier chain callbacks. It is controlled
08dfb4dd 1605 through debugfs interface under
d526e85f 1606 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
08dfb4dd
AM
1607
1608 If the notifier call chain should be failed with some events
1609 notified, write the error code to "actions/<notifier event>/error".
1610
1611 To compile this code as a module, choose M here: the module will
e12a95f4 1612 be called of-reconfig-notifier-error-inject.
08dfb4dd
AM
1613
1614 If unsure, say N.
1615
02fff96a
NA
1616config NETDEV_NOTIFIER_ERROR_INJECT
1617 tristate "Netdev notifier error injection module"
1618 depends on NET && NOTIFIER_ERROR_INJECTION
1619 help
1620 This option provides the ability to inject artificial errors to
1621 netdevice notifier chain callbacks. It is controlled through debugfs
1622 interface /sys/kernel/debug/notifier-error-inject/netdev
1623
1624 If the notifier call chain should be failed with some events
1625 notified, write the error code to "actions/<notifier event>/error".
1626
1627 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1628
1629 # cd /sys/kernel/debug/notifier-error-inject/netdev
1630 # echo -22 > actions/NETDEV_CHANGEMTU/error
1631 # ip link set eth0 mtu 1024
1632 RTNETLINK answers: Invalid argument
1633
1634 To compile this code as a module, choose M here: the module will
1635 be called netdev-notifier-error-inject.
1636
1637 If unsure, say N.
1638
f1b4bd06
MP
1639config FUNCTION_ERROR_INJECTION
1640 def_bool y
1641 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1642
6ff1cb35 1643config FAULT_INJECTION
1ab8509a
AM
1644 bool "Fault-injection framework"
1645 depends on DEBUG_KERNEL
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AM
1646 help
1647 Provide fault-injection framework.
1648 For more details, see Documentation/fault-injection/.
6ff1cb35 1649
8a8b6502 1650config FAILSLAB
1ab8509a
AM
1651 bool "Fault-injection capability for kmalloc"
1652 depends on FAULT_INJECTION
773ff60e 1653 depends on SLAB || SLUB
8a8b6502 1654 help
1ab8509a 1655 Provide fault-injection capability for kmalloc.
8a8b6502 1656
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AM
1657config FAIL_PAGE_ALLOC
1658 bool "Fault-injection capabilitiy for alloc_pages()"
1ab8509a 1659 depends on FAULT_INJECTION
933e312e 1660 help
1ab8509a 1661 Provide fault-injection capability for alloc_pages().
933e312e 1662
c17bb495 1663config FAIL_MAKE_REQUEST
86327d19 1664 bool "Fault-injection capability for disk IO"
581d4e28 1665 depends on FAULT_INJECTION && BLOCK
c17bb495 1666 help
1ab8509a 1667 Provide fault-injection capability for disk IO.
c17bb495 1668
581d4e28 1669config FAIL_IO_TIMEOUT
f4d01439 1670 bool "Fault-injection capability for faking disk interrupts"
581d4e28
JA
1671 depends on FAULT_INJECTION && BLOCK
1672 help
1673 Provide fault-injection capability on end IO handling. This
1674 will make the block layer "forget" an interrupt as configured,
1675 thus exercising the error handling.
1676
1677 Only works with drivers that use the generic timeout handling,
1678 for others it wont do anything.
1679
ab51fbab
DB
1680config FAIL_FUTEX
1681 bool "Fault-injection capability for futexes"
1682 select DEBUG_FS
1683 depends on FAULT_INJECTION && FUTEX
1684 help
1685 Provide fault-injection capability for futexes.
1686
f1b4bd06
MP
1687config FAULT_INJECTION_DEBUG_FS
1688 bool "Debugfs entries for fault-injection capabilities"
1689 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1690 help
1691 Enable configuration of fault-injection capabilities via debugfs.
1692
4b1a29a7
MH
1693config FAIL_FUNCTION
1694 bool "Fault-injection capability for functions"
1695 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1696 help
1697 Provide function-based fault-injection capability.
1698 This will allow you to override a specific function with a return
1699 with given return value. As a result, function caller will see
1700 an error value and have to handle it. This is useful to test the
1701 error handling in various subsystems.
1702
f1b4bd06
MP
1703config FAIL_MMC_REQUEST
1704 bool "Fault-injection capability for MMC IO"
1705 depends on FAULT_INJECTION_DEBUG_FS && MMC
6ff1cb35 1706 help
f1b4bd06
MP
1707 Provide fault-injection capability for MMC IO.
1708 This will make the mmc core return data errors. This is
1709 useful to test the error handling in the mmc block device
1710 and to test how the mmc host driver handles retries from
1711 the block device.
1df49008
AM
1712
1713config FAULT_INJECTION_STACKTRACE_FILTER
1714 bool "stacktrace filter for fault-injection capabilities"
1715 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
6d690dca 1716 depends on !X86_64
1df49008 1717 select STACKTRACE
f9b58e8c 1718 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1df49008
AM
1719 help
1720 Provide stacktrace filter for fault-injection capabilities
267c4025 1721
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1722config ARCH_HAS_KCOV
1723 bool
cc3fa840 1724 help
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CD
1725 An architecture should select this when it can successfully
1726 build and run with CONFIG_KCOV. This typically requires
1727 disabling instrumentation for some early boot code.
cc3fa840 1728
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CD
1729config CC_HAS_SANCOV_TRACE_PC
1730 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
cc3fa840 1731
cc3fa840 1732
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CD
1733config KCOV
1734 bool "Code coverage for fuzzing"
1735 depends on ARCH_HAS_KCOV
1736 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1737 select DEBUG_FS
1738 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1739 help
1740 KCOV exposes kernel code coverage information in a form suitable
1741 for coverage-guided fuzzing (randomized testing).
cc3fa840 1742
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CD
1743 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1744 different machines and across reboots. If you need stable PC values,
1745 disable RANDOMIZE_BASE.
cc3fa840 1746
09a74952 1747 For more details, see Documentation/dev-tools/kcov.rst.
cc3fa840 1748
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CD
1749config KCOV_ENABLE_COMPARISONS
1750 bool "Enable comparison operands collection by KCOV"
1751 depends on KCOV
1752 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1753 help
1754 KCOV also exposes operands of every comparison in the instrumented
1755 code along with operand sizes and PCs of the comparison instructions.
1756 These operands can be used by fuzzing engines to improve the quality
1757 of fuzzing coverage.
cc3fa840 1758
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CD
1759config KCOV_INSTRUMENT_ALL
1760 bool "Instrument all code by default"
1761 depends on KCOV
1762 default y
1763 help
1764 If you are doing generic system call fuzzing (like e.g. syzkaller),
1765 then you will want to instrument the whole kernel and you should
1766 say y here. If you are doing more targeted fuzzing (like e.g.
1767 filesystem fuzzing with AFL) then you will want to enable coverage
1768 for more specific subsets of files, and should say n here.
84bc809e 1769
d3deafaa
VL
1770menuconfig RUNTIME_TESTING_MENU
1771 bool "Runtime Testing"
908009e8 1772 def_bool y
d3deafaa
VL
1773
1774if RUNTIME_TESTING_MENU
881c5149
DH
1775
1776config LKDTM
1777 tristate "Linux Kernel Dump Test Tool Module"
1778 depends on DEBUG_FS
881c5149
DH
1779 help
1780 This module enables testing of the different dumping mechanisms by
1781 inducing system failures at predefined crash points.
1782 If you don't need it: say N
1783 Choose M here to compile this code as a module. The module will be
1784 called lkdtm.
1785
1786 Documentation on how to use the module can be found in
10ffebbe 1787 Documentation/fault-injection/provoke-crashes.rst
881c5149
DH
1788
1789config TEST_LIST_SORT
e327fd7c
GU
1790 tristate "Linked list sorting test"
1791 depends on DEBUG_KERNEL || m
881c5149
DH
1792 help
1793 Enable this to turn on 'list_sort()' function test. This test is
e327fd7c
GU
1794 executed only once during system boot (so affects only boot time),
1795 or at module load time.
881c5149
DH
1796
1797 If unsure, say N.
1798
6e24628d
IR
1799config TEST_MIN_HEAP
1800 tristate "Min heap test"
1801 depends on DEBUG_KERNEL || m
1802 help
1803 Enable this to turn on min heap function tests. This test is
1804 executed only once during system boot (so affects only boot time),
1805 or at module load time.
1806
1807 If unsure, say N.
1808
c5adae95 1809config TEST_SORT
5c4e6798
GU
1810 tristate "Array-based sort test"
1811 depends on DEBUG_KERNEL || m
c5adae95 1812 help
5c4e6798
GU
1813 This option enables the self-test function of 'sort()' at boot,
1814 or at module load time.
c5adae95
KF
1815
1816 If unsure, say N.
1817
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DH
1818config KPROBES_SANITY_TEST
1819 bool "Kprobes sanity tests"
1820 depends on DEBUG_KERNEL
1821 depends on KPROBES
881c5149
DH
1822 help
1823 This option provides for testing basic kprobes functionality on
5a6cf77f 1824 boot. Samples of kprobe and kretprobe are inserted and
881c5149
DH
1825 verified for functionality.
1826
1827 Say N if you are unsure.
1828
1829config BACKTRACE_SELF_TEST
1830 tristate "Self test for the backtrace code"
1831 depends on DEBUG_KERNEL
881c5149
DH
1832 help
1833 This option provides a kernel module that can be used to test
1834 the kernel stack backtrace code. This option is not useful
1835 for distributions or general kernels, but only for kernel
1836 developers working on architecture code.
1837
1838 Note that if you want to also test saved backtraces, you will
1839 have to enable STACKTRACE as well.
1840
1841 Say N if you are unsure.
1842
910a742d
ML
1843config RBTREE_TEST
1844 tristate "Red-Black tree test"
7c993e11 1845 depends on DEBUG_KERNEL
910a742d
ML
1846 help
1847 A benchmark measuring the performance of the rbtree library.
1848 Also includes rbtree invariant checks.
1849
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FB
1850config REED_SOLOMON_TEST
1851 tristate "Reed-Solomon library test"
1852 depends on DEBUG_KERNEL || m
1853 select REED_SOLOMON
1854 select REED_SOLOMON_ENC16
1855 select REED_SOLOMON_DEC16
1856 help
1857 This option enables the self-test function of rslib at boot,
1858 or at module load time.
1859
1860 If unsure, say N.
1861
fff3fd8a
ML
1862config INTERVAL_TREE_TEST
1863 tristate "Interval tree test"
0f789b67 1864 depends on DEBUG_KERNEL
a88cc108 1865 select INTERVAL_TREE
fff3fd8a
ML
1866 help
1867 A benchmark measuring the performance of the interval tree library
1868
623fd807
GT
1869config PERCPU_TEST
1870 tristate "Per cpu operations test"
1871 depends on m && DEBUG_KERNEL
1872 help
1873 Enable this option to build test module which validates per-cpu
1874 operations.
1875
1876 If unsure, say N.
1877
881c5149 1878config ATOMIC64_SELFTEST
55ded955 1879 tristate "Perform an atomic64_t self-test"
881c5149 1880 help
55ded955
GU
1881 Enable this option to test the atomic64_t functions at boot or
1882 at module load time.
881c5149
DH
1883
1884 If unsure, say N.
1885
1886config ASYNC_RAID6_TEST
1887 tristate "Self test for hardware accelerated raid6 recovery"
1888 depends on ASYNC_RAID6_RECOV
1889 select ASYNC_MEMCPY
1890 ---help---
1891 This is a one-shot self test that permutes through the
1892 recovery of all the possible two disk failure scenarios for a
1893 N-disk array. Recovery is performed with the asynchronous
1894 raid6 recovery routines, and will optionally use an offload
1895 engine if one is available.
1896
1897 If unsure, say N.
1898
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AS
1899config TEST_HEXDUMP
1900 tristate "Test functions located in the hexdump module at runtime"
1901
881c5149
DH
1902config TEST_STRING_HELPERS
1903 tristate "Test functions located in the string_helpers module at runtime"
1904
0b0600c8
TH
1905config TEST_STRSCPY
1906 tristate "Test strscpy*() family of functions at runtime"
1907
881c5149
DH
1908config TEST_KSTRTOX
1909 tristate "Test kstrto*() family of functions at runtime"
1910
707cc728
RV
1911config TEST_PRINTF
1912 tristate "Test printf() family of functions at runtime"
1913
5fd003f5
DD
1914config TEST_BITMAP
1915 tristate "Test bitmap_*() family of functions at runtime"
5fd003f5
DD
1916 help
1917 Enable this option to test the bitmap functions at boot.
1918
1919 If unsure, say N.
1920
0e2dc70e
JB
1921config TEST_BITFIELD
1922 tristate "Test bitfield functions at runtime"
1923 help
1924 Enable this option to test the bitfield functions at boot.
1925
1926 If unsure, say N.
1927
cfaff0e5
AS
1928config TEST_UUID
1929 tristate "Test functions located in the uuid module at runtime"
1930
ad3d6c72
MW
1931config TEST_XARRAY
1932 tristate "Test the XArray code at runtime"
1933
455a35a6
RV
1934config TEST_OVERFLOW
1935 tristate "Test check_*_overflow() functions at runtime"
1936
7e1e7763 1937config TEST_RHASHTABLE
9d6dbe1b 1938 tristate "Perform selftest on resizable hash table"
7e1e7763
TG
1939 help
1940 Enable this option to test the rhashtable functions at boot.
1941
1942 If unsure, say N.
1943
468a9428
GS
1944config TEST_HASH
1945 tristate "Perform selftest on hash functions"
468a9428 1946 help
2c956a60
JD
1947 Enable this option to test the kernel's integer (<linux/hash.h>),
1948 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
1949 hash functions on boot (or module load).
468a9428
GS
1950
1951 This is intended to help people writing architecture-specific
1952 optimized versions. If unsure, say N.
1953
8ab8ba38
MW
1954config TEST_IDA
1955 tristate "Perform selftest on IDA functions"
1956
44091d29
JP
1957config TEST_PARMAN
1958 tristate "Perform selftest on priority array manager"
44091d29
JP
1959 depends on PARMAN
1960 help
1961 Enable this option to test priority array manager on boot
1962 (or module load).
1963
1964 If unsure, say N.
1965
6aed82de
DL
1966config TEST_IRQ_TIMINGS
1967 bool "IRQ timings selftest"
1968 depends on IRQ_TIMINGS
1969 help
1970 Enable this option to test the irq timings code on boot.
1971
1972 If unsure, say N.
1973
8a6f0b47 1974config TEST_LKM
93e9ef83 1975 tristate "Test module loading with 'hello world' module"
93e9ef83
KC
1976 depends on m
1977 help
1978 This builds the "test_module" module that emits "Hello, world"
1979 on printk when loaded. It is designed to be used for basic
1980 evaluation of the module loading subsystem (for example when
1981 validating module verification). It lacks any extra dependencies,
1982 and will not normally be loaded by the system unless explicitly
1983 requested by name.
1984
1985 If unsure, say N.
1986
3f21a6b7
URS
1987config TEST_VMALLOC
1988 tristate "Test module for stress/performance analysis of vmalloc allocator"
1989 default n
1990 depends on MMU
1991 depends on m
1992 help
1993 This builds the "test_vmalloc" module that should be used for
1994 stress and performance analysis. So, any new change for vmalloc
1995 subsystem can be evaluated from performance and stability point
1996 of view.
1997
1998 If unsure, say N.
1999
3e2a4c18
KC
2000config TEST_USER_COPY
2001 tristate "Test user/kernel boundary protections"
3e2a4c18
KC
2002 depends on m
2003 help
2004 This builds the "test_user_copy" module that runs sanity checks
2005 on the copy_to/from_user infrastructure, making sure basic
2006 user/kernel boundary testing is working. If it fails to load,
2007 a regression has been detected in the user/kernel memory boundary
2008 protections.
2009
2010 If unsure, say N.
2011
64a8946b
AS
2012config TEST_BPF
2013 tristate "Test BPF filter functionality"
98920ba6 2014 depends on m && NET
64a8946b
AS
2015 help
2016 This builds the "test_bpf" module that runs various test vectors
2017 against the BPF interpreter or BPF JIT compiler depending on the
2018 current setting. This is in particular useful for BPF JIT compiler
2019 development, but also to run regression tests against changes in
3c731eba
AS
2020 the interpreter code. It also enables test stubs for eBPF maps and
2021 verifier used by user space verifier testsuite.
64a8946b
AS
2022
2023 If unsure, say N.
2024
509e56b3
MB
2025config TEST_BLACKHOLE_DEV
2026 tristate "Test blackhole netdev functionality"
2027 depends on m && NET
2028 help
2029 This builds the "test_blackhole_dev" module that validates the
2030 data path through this blackhole netdev.
2031
2032 If unsure, say N.
2033
dceeb3e7 2034config FIND_BIT_BENCHMARK
4441fca0 2035 tristate "Test find_bit functions"
4441fca0
YN
2036 help
2037 This builds the "test_find_bit" module that measure find_*_bit()
2038 functions performance.
2039
2040 If unsure, say N.
2041
0a8adf58
KC
2042config TEST_FIRMWARE
2043 tristate "Test firmware loading via userspace interface"
0a8adf58
KC
2044 depends on FW_LOADER
2045 help
2046 This builds the "test_firmware" module that creates a userspace
2047 interface for testing firmware loading. This can be used to
2048 control the triggering of firmware loading without needing an
2049 actual firmware-using device. The contents can be rechecked by
2050 userspace.
2051
2052 If unsure, say N.
2053
9308f2f9
LR
2054config TEST_SYSCTL
2055 tristate "sysctl test driver"
9308f2f9
LR
2056 depends on PROC_SYSCTL
2057 help
2058 This builds the "test_sysctl" module. This driver enables to test the
2059 proc sysctl interfaces available to drivers safely without affecting
2060 production knobs which might alter system functionality.
2061
2062 If unsure, say N.
2063
2cb80dbb 2064config SYSCTL_KUNIT_TEST
c475c77d 2065 tristate "KUnit test for sysctl"
2cb80dbb
IZ
2066 depends on KUNIT
2067 help
2068 This builds the proc sysctl unit test, which runs on boot.
2069 Tests the API contract and implementation correctness of sysctl.
2070 For more information on KUnit and unit tests in general please refer
2071 to the KUnit documentation in Documentation/dev-tools/kunit/.
2072
2073 If unsure, say N.
2074
ea2dd7c0 2075config LIST_KUNIT_TEST
c475c77d 2076 tristate "KUnit Test for Kernel Linked-list structures"
ea2dd7c0
DG
2077 depends on KUNIT
2078 help
2079 This builds the linked list KUnit test suite.
2080 It tests that the API and basic functionality of the list_head type
2081 and associated macros.
2082
2083 KUnit tests run during boot and output the results to the debug log
2084 in TAP format (http://testanything.org/). Only useful for kernel devs
2085 running the KUnit test harness, and not intended for inclusion into a
2086 production build.
2087
2088 For more information on KUnit and unit tests in general please refer
2089 to the KUnit documentation in Documentation/dev-tools/kunit/.
2090
2091 If unsure, say N.
2092
e704f93a
DR
2093config TEST_UDELAY
2094 tristate "udelay test driver"
e704f93a
DR
2095 help
2096 This builds the "udelay_test" module that helps to make sure
2097 that udelay() is working properly.
2098
2099 If unsure, say N.
2100
2bf9e0ab
IM
2101config TEST_STATIC_KEYS
2102 tristate "Test static keys"
579e1acb
JB
2103 depends on m
2104 help
2bf9e0ab 2105 Test the static key interfaces.
579e1acb
JB
2106
2107 If unsure, say N.
2108
d9c6a72d
LR
2109config TEST_KMOD
2110 tristate "kmod stress tester"
d9c6a72d 2111 depends on m
d9c6a72d 2112 depends on NETDEVICES && NET_CORE && INET # for TUN
ae3d6a32 2113 depends on BLOCK
d9c6a72d
LR
2114 select TEST_LKM
2115 select XFS_FS
2116 select TUN
2117 select BTRFS_FS
2118 help
2119 Test the kernel's module loading mechanism: kmod. kmod implements
2120 support to load modules using the Linux kernel's usermode helper.
2121 This test provides a series of tests against kmod.
2122
2123 Although technically you can either build test_kmod as a module or
2124 into the kernel we disallow building it into the kernel since
2125 it stress tests request_module() and this will very likely cause
2126 some issues by taking over precious threads available from other
2127 module load requests, ultimately this could be fatal.
2128
2129 To run tests run:
2130
2131 tools/testing/selftests/kmod/kmod.sh --help
2132
2133 If unsure, say N.
2134
e4dace36
FF
2135config TEST_DEBUG_VIRTUAL
2136 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2137 depends on DEBUG_VIRTUAL
2138 help
2139 Test the kernel's ability to detect incorrect calls to
2140 virt_to_phys() done against the non-linear part of the
2141 kernel's virtual address map.
2142
2143 If unsure, say N.
2144
ce76d938
AS
2145config TEST_MEMCAT_P
2146 tristate "Test memcat_p() helper function"
2147 help
2148 Test the memcat_p() helper for correctly merging two
2149 pointer arrays together.
2150
2151 If unsure, say N.
2152
a2818ee4
JL
2153config TEST_LIVEPATCH
2154 tristate "Test livepatching"
2155 default n
bae05437 2156 depends on DYNAMIC_DEBUG
a2818ee4
JL
2157 depends on LIVEPATCH
2158 depends on m
2159 help
2160 Test kernel livepatching features for correctness. The tests will
2161 load test modules that will be livepatched in various scenarios.
2162
2163 To run all the livepatching tests:
2164
2165 make -C tools/testing/selftests TARGETS=livepatch run_tests
2166
2167 Alternatively, individual tests may be invoked:
2168
2169 tools/testing/selftests/livepatch/test-callbacks.sh
2170 tools/testing/selftests/livepatch/test-livepatch.sh
2171 tools/testing/selftests/livepatch/test-shadow-vars.sh
2172
2173 If unsure, say N.
2174
0a020d41
JP
2175config TEST_OBJAGG
2176 tristate "Perform selftest on object aggreration manager"
2177 default n
2178 depends on OBJAGG
2179 help
2180 Enable this option to test object aggregation manager on boot
2181 (or module load).
2182
0a020d41 2183
50ceaa95
KC
2184config TEST_STACKINIT
2185 tristate "Test level of stack variable initialization"
2186 help
2187 Test if the kernel is zero-initializing stack variables and
2188 padding. Coverage is controlled by compiler flags,
2189 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2190 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2191
2192 If unsure, say N.
2193
5015a300
AP
2194config TEST_MEMINIT
2195 tristate "Test heap/page initialization"
2196 help
2197 Test if the kernel is zero-initializing heap and page allocations.
2198 This can be useful to test init_on_alloc and init_on_free features.
2199
2200 If unsure, say N.
2201
d3deafaa 2202endif # RUNTIME_TESTING_MENU
cc3fa840
RD
2203
2204config MEMTEST
2205 bool "Memtest"
cc3fa840
RD
2206 ---help---
2207 This option adds a kernel parameter 'memtest', which allows memtest
2208 to be set.
2209 memtest=0, mean disabled; -- default
2210 memtest=1, mean do 1 test pattern;
2211 ...
2212 memtest=17, mean do 17 test patterns.
2213 If you are unsure how to answer this question, answer N.
2214
21266be9 2215
06ec64b8 2216
af9ca6f9
BB
2217config HYPERV_TESTING
2218 bool "Microsoft Hyper-V driver testing"
2219 default n
2220 depends on HYPERV && DEBUG_FS
2221 help
2222 Select this option to enable Hyper-V vmbus testing.
2223
045f6d79
CD
2224endmenu # "Kernel Testing and Coverage"
2225
06ec64b8 2226endmenu # Kernel hacking