Christoph Hellwig | 06ec64b | 2018-07-31 13:39:31 +0200 | [diff] [blame] | 1 | menu "Kernel hacking" |
| 2 | |
Dave Hansen | 604ff0d | 2013-07-01 13:04:49 -0700 | [diff] [blame] | 3 | menu "printk and dmesg options" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | |
| 5 | config PRINTK_TIME |
| 6 | bool "Show timing information on printks" |
Randy Dunlap | d3b8b6e | 2006-12-06 20:36:38 -0800 | [diff] [blame] | 7 | depends on PRINTK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | help |
Kay Sievers | 649e6ee | 2012-05-10 04:30:45 +0200 | [diff] [blame] | 9 | Selecting this option causes time stamps of the printk() |
| 10 | messages to be added to the output of the syslog() system |
| 11 | call and at the console. |
| 12 | |
| 13 | The timestamp is always recorded internally, and exported |
| 14 | to /dev/kmsg. This flag just specifies if the timestamp should |
| 15 | be included, not that the timestamp is recorded. |
| 16 | |
| 17 | The behavior is also controlled by the kernel command line |
Mauro Carvalho Chehab | 8c27ceff3 | 2016-10-18 10:12:27 -0200 | [diff] [blame] | 18 | parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
Olof Johansson | a8cfdc6 | 2016-12-12 16:45:56 -0800 | [diff] [blame] | 20 | config CONSOLE_LOGLEVEL_DEFAULT |
| 21 | int "Default console loglevel (1-15)" |
| 22 | range 1 15 |
| 23 | default "7" |
| 24 | help |
| 25 | Default loglevel to determine what will be printed on the console. |
| 26 | |
| 27 | Setting a default here is equivalent to passing in loglevel=<x> in |
| 28 | the kernel bootargs. loglevel=<x> continues to override whatever |
| 29 | value is specified here as well. |
| 30 | |
Borislav Petkov | 50f4d9b | 2016-12-19 16:23:15 -0800 | [diff] [blame] | 31 | Note: This does not affect the log level of un-prefixed printk() |
Olof Johansson | a8cfdc6 | 2016-12-12 16:45:56 -0800 | [diff] [blame] | 32 | usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT |
| 33 | option. |
| 34 | |
Hans de Goede | 22eceb8 | 2018-06-19 13:57:26 +0200 | [diff] [blame] | 35 | config CONSOLE_LOGLEVEL_QUIET |
| 36 | int "quiet console loglevel (1-15)" |
| 37 | range 1 15 |
| 38 | default "4" |
| 39 | help |
| 40 | loglevel to use when "quiet" is passed on the kernel commandline. |
| 41 | |
| 42 | When "quiet" is passed on the kernel commandline this loglevel |
| 43 | will be used as the loglevel. IOW passing "quiet" will be the |
| 44 | equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>" |
| 45 | |
Alex Elder | 42a9dc0 | 2014-08-06 16:09:01 -0700 | [diff] [blame] | 46 | config MESSAGE_LOGLEVEL_DEFAULT |
Mandeep Singh Baines | 5af5bcb | 2011-03-22 16:34:23 -0700 | [diff] [blame] | 47 | int "Default message log level (1-7)" |
| 48 | range 1 7 |
| 49 | default "4" |
| 50 | help |
| 51 | Default log level for printk statements with no specified priority. |
| 52 | |
| 53 | This was hard-coded to KERN_WARNING since at least 2.6.10 but folks |
| 54 | that are auditing their logs closely may want to set it to a lower |
| 55 | priority. |
| 56 | |
Olof Johansson | a8cfdc6 | 2016-12-12 16:45:56 -0800 | [diff] [blame] | 57 | Note: This does not affect what message level gets printed on the console |
| 58 | by default. To change that, use loglevel=<x> in the kernel bootargs, |
| 59 | or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value. |
| 60 | |
Dave Hansen | 604ff0d | 2013-07-01 13:04:49 -0700 | [diff] [blame] | 61 | config BOOT_PRINTK_DELAY |
| 62 | bool "Delay each boot printk message by N milliseconds" |
| 63 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
| 64 | help |
| 65 | This build option allows you to read kernel boot messages |
| 66 | by inserting a short delay after each one. The delay is |
| 67 | specified in milliseconds on the kernel command line, |
| 68 | using "boot_delay=N". |
| 69 | |
| 70 | It is likely that you would also need to use "lpj=M" to preset |
| 71 | the "loops per jiffie" value. |
| 72 | See a previous boot log for the "lpj" value to use for your |
| 73 | system, and then set "lpj=M" before setting "boot_delay=N". |
| 74 | NOTE: Using this option may adversely affect SMP systems. |
| 75 | I.e., processors other than the first one may not boot up. |
| 76 | BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect |
| 77 | what it believes to be lockup conditions. |
| 78 | |
| 79 | config DYNAMIC_DEBUG |
| 80 | bool "Enable dynamic printk() support" |
| 81 | default n |
| 82 | depends on PRINTK |
| 83 | depends on DEBUG_FS |
| 84 | help |
| 85 | |
| 86 | Compiles debug level messages into the kernel, which would not |
| 87 | otherwise be available at runtime. These messages can then be |
| 88 | enabled/disabled based on various levels of scope - per source file, |
| 89 | function, module, format string, and line number. This mechanism |
| 90 | implicitly compiles in all pr_debug() and dev_dbg() calls, which |
| 91 | enlarges the kernel text size by about 2%. |
| 92 | |
| 93 | If a source file is compiled with DEBUG flag set, any |
| 94 | pr_debug() calls in it are enabled by default, but can be |
| 95 | disabled at runtime as below. Note that DEBUG flag is |
| 96 | turned on by many CONFIG_*DEBUG* options. |
| 97 | |
| 98 | Usage: |
| 99 | |
| 100 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
| 101 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
| 102 | filesystem must first be mounted before making use of this feature. |
| 103 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
| 104 | file contains a list of the debug statements that can be enabled. The |
| 105 | format for each line of the file is: |
| 106 | |
| 107 | filename:lineno [module]function flags format |
| 108 | |
| 109 | filename : source file of the debug statement |
| 110 | lineno : line number of the debug statement |
| 111 | module : module that contains the debug statement |
| 112 | function : function that contains the debug statement |
| 113 | flags : '=p' means the line is turned 'on' for printing |
| 114 | format : the format used for the debug statement |
| 115 | |
| 116 | From a live system: |
| 117 | |
| 118 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
| 119 | # filename:lineno [module]function flags format |
| 120 | fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012" |
| 121 | fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012" |
| 122 | fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012" |
| 123 | |
| 124 | Example usage: |
| 125 | |
| 126 | // enable the message at line 1603 of file svcsock.c |
| 127 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
| 128 | <debugfs>/dynamic_debug/control |
| 129 | |
| 130 | // enable all the messages in file svcsock.c |
| 131 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
| 132 | <debugfs>/dynamic_debug/control |
| 133 | |
| 134 | // enable all the messages in the NFS server module |
| 135 | nullarbor:~ # echo -n 'module nfsd +p' > |
| 136 | <debugfs>/dynamic_debug/control |
| 137 | |
| 138 | // enable all 12 messages in the function svc_process() |
| 139 | nullarbor:~ # echo -n 'func svc_process +p' > |
| 140 | <debugfs>/dynamic_debug/control |
| 141 | |
| 142 | // disable all 12 messages in the function svc_process() |
| 143 | nullarbor:~ # echo -n 'func svc_process -p' > |
| 144 | <debugfs>/dynamic_debug/control |
| 145 | |
Hans Holmberg | f8998c2 | 2017-03-16 09:37:32 +0100 | [diff] [blame] | 146 | See Documentation/admin-guide/dynamic-debug-howto.rst for additional |
| 147 | information. |
Dave Hansen | 604ff0d | 2013-07-01 13:04:49 -0700 | [diff] [blame] | 148 | |
| 149 | endmenu # "printk and dmesg options" |
| 150 | |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 151 | menu "Compile-time checks and compiler options" |
| 152 | |
| 153 | config DEBUG_INFO |
| 154 | bool "Compile the kernel with debug info" |
Linus Torvalds | 12b1383 | 2014-02-04 12:20:01 -0800 | [diff] [blame] | 155 | depends on DEBUG_KERNEL && !COMPILE_TEST |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 156 | help |
| 157 | If you say Y here the resulting kernel image will include |
| 158 | debugging info resulting in a larger kernel image. |
| 159 | This adds debug symbols to the kernel and modules (gcc -g), and |
| 160 | is needed if you intend to use kernel crashdump or binary object |
| 161 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
| 162 | Say Y here only if you plan to debug the kernel. |
| 163 | |
| 164 | If unsure, say N. |
| 165 | |
| 166 | config DEBUG_INFO_REDUCED |
| 167 | bool "Reduce debugging information" |
| 168 | depends on DEBUG_INFO |
| 169 | help |
| 170 | If you say Y here gcc is instructed to generate less debugging |
| 171 | information for structure types. This means that tools that |
| 172 | need full debugging information (like kgdb or systemtap) won't |
| 173 | be happy. But if you merely need debugging information to |
| 174 | resolve line numbers there is no loss. Advantage is that |
| 175 | build directory object sizes shrink dramatically over a full |
| 176 | DEBUG_INFO build and compile times are reduced too. |
| 177 | Only works with newer gcc versions. |
| 178 | |
Andi Kleen | 866ced9 | 2014-07-30 20:50:18 +0200 | [diff] [blame] | 179 | config DEBUG_INFO_SPLIT |
| 180 | bool "Produce split debuginfo in .dwo files" |
Arnd Bergmann | a687a53 | 2018-03-07 23:30:54 +0100 | [diff] [blame] | 181 | depends on DEBUG_INFO |
Andi Kleen | 866ced9 | 2014-07-30 20:50:18 +0200 | [diff] [blame] | 182 | help |
| 183 | Generate debug info into separate .dwo files. This significantly |
| 184 | reduces the build directory size for builds with DEBUG_INFO, |
| 185 | because it stores the information only once on disk in .dwo |
| 186 | files instead of multiple times in object files and executables. |
| 187 | In addition the debug information is also compressed. |
| 188 | |
| 189 | Requires recent gcc (4.7+) and recent gdb/binutils. |
| 190 | Any tool that packages or reads debug information would need |
| 191 | to know about the .dwo files and include them. |
| 192 | Incompatible with older versions of ccache. |
| 193 | |
Andi Kleen | bfaf2dd | 2014-07-30 20:50:19 +0200 | [diff] [blame] | 194 | config DEBUG_INFO_DWARF4 |
| 195 | bool "Generate dwarf4 debuginfo" |
| 196 | depends on DEBUG_INFO |
| 197 | help |
| 198 | Generate dwarf4 debug info. This requires recent versions |
| 199 | of gcc and gdb. It makes the debug information larger. |
| 200 | But it significantly improves the success of resolving |
| 201 | variables in gdb on optimized code. |
| 202 | |
Jan Kiszka | 3ee7b3f | 2015-02-17 13:46:36 -0800 | [diff] [blame] | 203 | config GDB_SCRIPTS |
| 204 | bool "Provide GDB scripts for kernel debugging" |
| 205 | depends on DEBUG_INFO |
| 206 | help |
| 207 | This creates the required links to GDB helper scripts in the |
| 208 | build directory. If you load vmlinux into gdb, the helper |
| 209 | scripts will be automatically imported by gdb as well, and |
| 210 | additional functions are available to analyze a Linux kernel |
Andreas Platschek | 700199b0 | 2016-12-14 15:05:40 -0800 | [diff] [blame] | 211 | instance. See Documentation/dev-tools/gdb-kernel-debugging.rst |
| 212 | for further details. |
Jan Kiszka | 3ee7b3f | 2015-02-17 13:46:36 -0800 | [diff] [blame] | 213 | |
Andrew Morton | cebc04b | 2006-08-14 22:43:18 -0700 | [diff] [blame] | 214 | config ENABLE_MUST_CHECK |
| 215 | bool "Enable __must_check logic" |
| 216 | default y |
| 217 | help |
| 218 | Enable the __must_check logic in the kernel build. Disable this to |
| 219 | suppress the "warning: ignoring return value of 'foo', declared with |
| 220 | attribute warn_unused_result" messages. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | |
Andi Kleen | 35bb5b1 | 2008-02-22 15:15:03 +0100 | [diff] [blame] | 222 | config FRAME_WARN |
| 223 | int "Warn for stack frames larger than (needs gcc 4.4)" |
| 224 | range 0 8192 |
Arnd Bergmann | e7c52b8 | 2018-02-06 15:41:41 -0800 | [diff] [blame] | 225 | default 3072 if KASAN_EXTRA |
Kees Cook | 0e07f66 | 2016-10-27 17:46:41 -0700 | [diff] [blame] | 226 | default 2048 if GCC_PLUGIN_LATENT_ENTROPY |
Helge Deller | 432654d | 2017-09-11 21:41:43 +0200 | [diff] [blame] | 227 | default 1280 if (!64BIT && PARISC) |
| 228 | default 1024 if (!64BIT && !PARISC) |
Andi Kleen | 35bb5b1 | 2008-02-22 15:15:03 +0100 | [diff] [blame] | 229 | default 2048 if 64BIT |
| 230 | help |
| 231 | Tell gcc to warn at build time for stack frames larger than this. |
| 232 | Setting this too low will cause a lot of warnings. |
| 233 | Setting it to 0 disables the warning. |
| 234 | Requires gcc 4.4 |
| 235 | |
Randy Dunlap | 99657c7 | 2009-09-18 12:49:22 -0700 | [diff] [blame] | 236 | config STRIP_ASM_SYMS |
| 237 | bool "Strip assembler-generated symbols during link" |
| 238 | default n |
| 239 | help |
| 240 | Strip internal assembler-generated symbols during a link (symbols |
| 241 | that look like '.Lxxx') so they don't pollute the output of |
| 242 | get_wchan() and suchlike. |
| 243 | |
Andi Kleen | 1873e87 | 2012-03-28 11:51:18 -0700 | [diff] [blame] | 244 | config READABLE_ASM |
| 245 | bool "Generate readable assembler code" |
| 246 | depends on DEBUG_KERNEL |
| 247 | help |
| 248 | Disable some compiler optimizations that tend to generate human unreadable |
| 249 | assembler output. This may make the kernel slightly slower, but it helps |
| 250 | to keep kernel developers who have to stare a lot at assembler listings |
| 251 | sane. |
| 252 | |
Arjan van de Ven | f71d20e | 2006-06-28 04:26:45 -0700 | [diff] [blame] | 253 | config UNUSED_SYMBOLS |
| 254 | bool "Enable unused/obsolete exported symbols" |
| 255 | default y if X86 |
| 256 | help |
| 257 | Unused but exported symbols make the kernel needlessly bigger. For |
| 258 | that reason most of these unused exports will soon be removed. This |
| 259 | option is provided temporarily to provide a transition period in case |
| 260 | some external kernel module needs one of these symbols anyway. If you |
| 261 | encounter such a case in your module, consider if you are actually |
| 262 | using the right API. (rationale: since nobody in the kernel is using |
| 263 | this in a module, there is a pretty good chance it's actually the |
| 264 | wrong interface to use). If you really need the symbol, please send a |
| 265 | mail to the linux kernel mailing list mentioning the symbol and why |
| 266 | you really need it, and what the merge plan to the mainline kernel for |
| 267 | your module is. |
| 268 | |
Joonsoo Kim | 48c96a3 | 2014-12-12 16:56:01 -0800 | [diff] [blame] | 269 | config PAGE_OWNER |
| 270 | bool "Track page owner" |
| 271 | depends on DEBUG_KERNEL && STACKTRACE_SUPPORT |
| 272 | select DEBUG_FS |
| 273 | select STACKTRACE |
Joonsoo Kim | f2ca0b5 | 2016-07-26 15:23:55 -0700 | [diff] [blame] | 274 | select STACKDEPOT |
Joonsoo Kim | 48c96a3 | 2014-12-12 16:56:01 -0800 | [diff] [blame] | 275 | select PAGE_EXTENSION |
| 276 | help |
| 277 | This keeps track of what call chain is the owner of a page, may |
| 278 | help to find bare alloc_page(s) leaks. Even if you include this |
| 279 | feature on your build, it is disabled in default. You should pass |
| 280 | "page_owner=on" to boot parameter in order to enable it. Eats |
| 281 | a fair amount of memory if enabled. See tools/vm/page_owner_sort.c |
| 282 | for user-space helper. |
| 283 | |
| 284 | If unsure, say N. |
| 285 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 286 | config DEBUG_FS |
| 287 | bool "Debug Filesystem" |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 288 | help |
| 289 | debugfs is a virtual file system that kernel developers use to put |
| 290 | debugging files into. Enable this option to be able to read and |
| 291 | write to these files. |
| 292 | |
Robert P. J. Day | ff54333 | 2008-05-20 00:06:00 +0200 | [diff] [blame] | 293 | For detailed documentation on the debugfs API, see |
Mauro Carvalho Chehab | e1b4fc7 | 2017-05-14 12:04:55 -0300 | [diff] [blame] | 294 | Documentation/filesystems/. |
Robert P. J. Day | ff54333 | 2008-05-20 00:06:00 +0200 | [diff] [blame] | 295 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 296 | If unsure, say N. |
| 297 | |
| 298 | config HEADERS_CHECK |
| 299 | bool "Run 'make headers_check' when building vmlinux" |
| 300 | depends on !UML |
| 301 | help |
| 302 | This option will extract the user-visible kernel headers whenever |
| 303 | building the kernel, and will run basic sanity checks on them to |
| 304 | ensure that exported files do not attempt to include files which |
| 305 | were not exported, etc. |
| 306 | |
| 307 | If you're making modifications to header files which are |
| 308 | relevant for userspace, say 'Y', and check the headers |
| 309 | exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in |
| 310 | your build tree), to make sure they're suitable. |
| 311 | |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 312 | config DEBUG_SECTION_MISMATCH |
| 313 | bool "Enable full Section mismatch analysis" |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 314 | help |
| 315 | The section mismatch analysis checks if there are illegal |
| 316 | references from one section to another section. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 317 | During linktime or runtime, some sections are dropped; |
| 318 | any use of code/data previously in these sections would |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 319 | most likely result in an oops. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 320 | In the code, functions and variables are annotated with |
Paul Gortmaker | 0db0628 | 2013-06-19 14:53:51 -0400 | [diff] [blame] | 321 | __init,, etc. (see the full list in include/linux/init.h), |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 322 | which results in the code/data being placed in specific sections. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 323 | The section mismatch analysis is always performed after a full |
| 324 | kernel build, and enabling this option causes the following |
| 325 | additional steps to occur: |
| 326 | - Add the option -fno-inline-functions-called-once to gcc commands. |
| 327 | When inlining a function annotated with __init in a non-init |
| 328 | function, we would lose the section information and thus |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 329 | the analysis would not catch the illegal reference. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 330 | This option tells gcc to inline less (but it does result in |
| 331 | a larger kernel). |
Nicholas Piggin | f49821e | 2018-02-11 00:25:04 +1000 | [diff] [blame] | 332 | - Run the section mismatch analysis for each module/built-in.a file. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 333 | When we run the section mismatch analysis on vmlinux.o, we |
Uwe Kleine-König | 67797b9 | 2016-09-09 10:04:58 +0200 | [diff] [blame] | 334 | lose valuable information about where the mismatch was |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 335 | introduced. |
Nicholas Piggin | f49821e | 2018-02-11 00:25:04 +1000 | [diff] [blame] | 336 | Running the analysis for each module/built-in.a file |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 337 | tells where the mismatch happens much closer to the |
| 338 | source. The drawback is that the same mismatch is |
| 339 | reported at least twice. |
| 340 | - Enable verbose reporting from modpost in order to help resolve |
| 341 | the section mismatches that are reported. |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 342 | |
Nicolas Boichat | 47490ec | 2015-10-06 09:44:42 +1030 | [diff] [blame] | 343 | config SECTION_MISMATCH_WARN_ONLY |
| 344 | bool "Make section mismatch errors non-fatal" |
| 345 | default y |
| 346 | help |
| 347 | If you say N here, the build process will fail if there are any |
| 348 | section mismatch, instead of just throwing warnings. |
| 349 | |
| 350 | If unsure, say Y. |
| 351 | |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 352 | # |
| 353 | # Select this config option from the architecture Kconfig, if it |
| 354 | # is preferred to always offer frame pointers as a config |
| 355 | # option on the architecture (regardless of KERNEL_DEBUG): |
| 356 | # |
| 357 | config ARCH_WANT_FRAME_POINTERS |
| 358 | bool |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 359 | |
| 360 | config FRAME_POINTER |
| 361 | bool "Compile the kernel with frame pointers" |
Arnd Bergmann | a687a53 | 2018-03-07 23:30:54 +0100 | [diff] [blame] | 362 | depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 363 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
| 364 | help |
| 365 | If you say Y here the resulting kernel image will be slightly |
| 366 | larger and slower, but it gives very useful debugging information |
| 367 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
| 368 | |
Josh Poimboeuf | b9ab5eb | 2016-02-28 22:22:42 -0600 | [diff] [blame] | 369 | config STACK_VALIDATION |
| 370 | bool "Compile-time stack metadata validation" |
| 371 | depends on HAVE_STACK_VALIDATION |
| 372 | default n |
| 373 | help |
| 374 | Add compile-time checks to validate stack metadata, including frame |
| 375 | pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure |
| 376 | that runtime stack traces are more reliable. |
| 377 | |
Josh Poimboeuf | ee9f8fc | 2017-07-24 18:36:57 -0500 | [diff] [blame] | 378 | This is also a prerequisite for generation of ORC unwind data, which |
Josh Poimboeuf | 11af847 | 2017-10-13 15:02:00 -0500 | [diff] [blame] | 379 | is needed for CONFIG_UNWINDER_ORC. |
Josh Poimboeuf | ee9f8fc | 2017-07-24 18:36:57 -0500 | [diff] [blame] | 380 | |
Josh Poimboeuf | b9ab5eb | 2016-02-28 22:22:42 -0600 | [diff] [blame] | 381 | For more information, see |
| 382 | tools/objtool/Documentation/stack-validation.txt. |
| 383 | |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 384 | config DEBUG_FORCE_WEAK_PER_CPU |
| 385 | bool "Force weak per-cpu definitions" |
| 386 | depends on DEBUG_KERNEL |
| 387 | help |
| 388 | s390 and alpha require percpu variables in modules to be |
| 389 | defined weak to work around addressing range issue which |
| 390 | puts the following two restrictions on percpu variable |
| 391 | definitions. |
| 392 | |
| 393 | 1. percpu symbols must be unique whether static or not |
| 394 | 2. percpu variables can't be defined inside a function |
| 395 | |
| 396 | To ensure that generic code follows the above rules, this |
| 397 | option forces all percpu variables to be defined as weak. |
| 398 | |
| 399 | endmenu # "Compiler options" |
| 400 | |
| 401 | config MAGIC_SYSRQ |
| 402 | bool "Magic SysRq key" |
| 403 | depends on !UML |
| 404 | help |
| 405 | If you say Y here, you will have some control over the system even |
| 406 | if the system crashes for example during kernel debugging (e.g., you |
| 407 | will be able to flush the buffer cache to disk, reboot the system |
| 408 | immediately or dump some status information). This is accomplished |
| 409 | by pressing various keys while holding SysRq (Alt+PrintScreen). It |
| 410 | also works on a serial console (on PC hardware at least), if you |
| 411 | send a BREAK and then within 5 seconds a command keypress. The |
Hans Holmberg | f8998c2 | 2017-03-16 09:37:32 +0100 | [diff] [blame] | 412 | keys are documented in <file:Documentation/admin-guide/sysrq.rst>. |
| 413 | Don't say Y unless you really know what this hack does. |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 414 | |
Ben Hutchings | 8eaede4 | 2013-10-07 01:05:46 +0100 | [diff] [blame] | 415 | config MAGIC_SYSRQ_DEFAULT_ENABLE |
| 416 | hex "Enable magic SysRq key functions by default" |
| 417 | depends on MAGIC_SYSRQ |
| 418 | default 0x1 |
| 419 | help |
| 420 | Specifies which SysRq key functions are enabled by default. |
| 421 | This may be set to 1 or 0 to enable or disable them all, or |
Hans Holmberg | f8998c2 | 2017-03-16 09:37:32 +0100 | [diff] [blame] | 422 | to a bitmask as described in Documentation/admin-guide/sysrq.rst. |
Ben Hutchings | 8eaede4 | 2013-10-07 01:05:46 +0100 | [diff] [blame] | 423 | |
Felix Fietkau | 732dbf3 | 2016-12-22 08:31:34 +0100 | [diff] [blame] | 424 | config MAGIC_SYSRQ_SERIAL |
| 425 | bool "Enable magic SysRq key over serial" |
| 426 | depends on MAGIC_SYSRQ |
| 427 | default y |
| 428 | help |
| 429 | Many embedded boards have a disconnected TTL level serial which can |
| 430 | generate some garbage that can lead to spurious false sysrq detects. |
| 431 | This option allows you to decide whether you want to enable the |
| 432 | magic SysRq key. |
| 433 | |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 434 | config DEBUG_KERNEL |
| 435 | bool "Kernel debugging" |
| 436 | help |
| 437 | Say Y here if you are developing drivers or trying to debug and |
| 438 | identify kernel problems. |
| 439 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 440 | menu "Memory Debugging" |
David Woodhouse | a304e1b | 2007-02-12 00:52:00 -0800 | [diff] [blame] | 441 | |
Masahiro Yamada | 8636a1f | 2018-12-11 20:01:04 +0900 | [diff] [blame] | 442 | source "mm/Kconfig.debug" |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 443 | |
Thomas Gleixner | 3ac7fe5 | 2008-04-30 00:55:01 -0700 | [diff] [blame] | 444 | config DEBUG_OBJECTS |
| 445 | bool "Debug object operations" |
| 446 | depends on DEBUG_KERNEL |
| 447 | help |
| 448 | If you say Y here, additional code will be inserted into the |
| 449 | kernel to track the life time of various objects and validate |
| 450 | the operations on those objects. |
| 451 | |
| 452 | config DEBUG_OBJECTS_SELFTEST |
| 453 | bool "Debug objects selftest" |
| 454 | depends on DEBUG_OBJECTS |
| 455 | help |
| 456 | This enables the selftest of the object debug code. |
| 457 | |
| 458 | config DEBUG_OBJECTS_FREE |
| 459 | bool "Debug objects in freed memory" |
| 460 | depends on DEBUG_OBJECTS |
| 461 | help |
| 462 | This enables checks whether a k/v free operation frees an area |
| 463 | which contains an object which has not been deactivated |
| 464 | properly. This can make kmalloc/kfree-intensive workloads |
| 465 | much slower. |
| 466 | |
Thomas Gleixner | c6f3a97 | 2008-04-30 00:55:03 -0700 | [diff] [blame] | 467 | config DEBUG_OBJECTS_TIMERS |
| 468 | bool "Debug timer objects" |
| 469 | depends on DEBUG_OBJECTS |
| 470 | help |
| 471 | If you say Y here, additional code will be inserted into the |
| 472 | timer routines to track the life time of timer objects and |
| 473 | validate the timer operations. |
| 474 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 475 | config DEBUG_OBJECTS_WORK |
| 476 | bool "Debug work objects" |
| 477 | depends on DEBUG_OBJECTS |
| 478 | help |
| 479 | If you say Y here, additional code will be inserted into the |
| 480 | work queue routines to track the life time of work objects and |
| 481 | validate the work operations. |
| 482 | |
Mathieu Desnoyers | 551d55a | 2010-04-17 08:48:42 -0400 | [diff] [blame] | 483 | config DEBUG_OBJECTS_RCU_HEAD |
| 484 | bool "Debug RCU callbacks objects" |
Mathieu Desnoyers | fc2ecf7 | 2011-02-23 09:42:14 -0800 | [diff] [blame] | 485 | depends on DEBUG_OBJECTS |
Mathieu Desnoyers | 551d55a | 2010-04-17 08:48:42 -0400 | [diff] [blame] | 486 | help |
| 487 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). |
| 488 | |
Tejun Heo | e2852ae | 2010-10-26 14:23:05 -0700 | [diff] [blame] | 489 | config DEBUG_OBJECTS_PERCPU_COUNTER |
| 490 | bool "Debug percpu counter objects" |
| 491 | depends on DEBUG_OBJECTS |
| 492 | help |
| 493 | If you say Y here, additional code will be inserted into the |
| 494 | percpu counter routines to track the life time of percpu counter |
| 495 | objects and validate the percpu counter operations. |
| 496 | |
Ingo Molnar | 3ae7020 | 2008-11-26 10:02:00 +0100 | [diff] [blame] | 497 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
| 498 | int "debug_objects bootup default value (0-1)" |
| 499 | range 0 1 |
| 500 | default "1" |
| 501 | depends on DEBUG_OBJECTS |
| 502 | help |
| 503 | Debug objects boot parameter default value |
| 504 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | config DEBUG_SLAB |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 506 | bool "Debug slab memory allocations" |
Levin, Alexander (Sasha Levin) | 4675ff0 | 2017-11-15 17:36:02 -0800 | [diff] [blame] | 507 | depends on DEBUG_KERNEL && SLAB |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | help |
| 509 | Say Y here to have the kernel do limited verification on memory |
| 510 | allocation as well as poisoning memory on free to catch use of freed |
| 511 | memory. This can make kmalloc/kfree-intensive workloads much slower. |
| 512 | |
Al Viro | 871751e | 2006-03-25 03:06:39 -0800 | [diff] [blame] | 513 | config DEBUG_SLAB_LEAK |
| 514 | bool "Memory leak debugging" |
| 515 | depends on DEBUG_SLAB |
| 516 | |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 517 | config SLUB_DEBUG_ON |
| 518 | bool "SLUB debugging on by default" |
Levin, Alexander (Sasha Levin) | 4675ff0 | 2017-11-15 17:36:02 -0800 | [diff] [blame] | 519 | depends on SLUB && SLUB_DEBUG |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 520 | default n |
| 521 | help |
| 522 | Boot with debugging on by default. SLUB boots by default with |
| 523 | the runtime debug capabilities switched off. Enabling this is |
| 524 | equivalent to specifying the "slub_debug" parameter on boot. |
| 525 | There is no support for more fine grained debug control like |
| 526 | possible with slub_debug=xxx. SLUB debugging may be switched |
| 527 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying |
| 528 | "slub_debug=-". |
| 529 | |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 530 | config SLUB_STATS |
| 531 | default n |
| 532 | bool "Enable SLUB performance statistics" |
Christoph Lameter | ab4d5ed | 2010-10-05 13:57:26 -0500 | [diff] [blame] | 533 | depends on SLUB && SYSFS |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 534 | help |
| 535 | SLUB statistics are useful to debug SLUBs allocation behavior in |
| 536 | order find ways to optimize the allocator. This should never be |
| 537 | enabled for production use since keeping statistics slows down |
| 538 | the allocator by a few percentage points. The slabinfo command |
| 539 | supports the determination of the most active slabs to figure |
| 540 | out which slabs are relevant to a particular load. |
| 541 | Try running: slabinfo -DA |
| 542 | |
Catalin Marinas | b69ec42 | 2012-10-08 16:28:11 -0700 | [diff] [blame] | 543 | config HAVE_DEBUG_KMEMLEAK |
| 544 | bool |
| 545 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 546 | config DEBUG_KMEMLEAK |
| 547 | bool "Kernel memory leak detector" |
Kees Cook | 525c1f9 | 2013-01-16 18:54:16 -0800 | [diff] [blame] | 548 | depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK |
Catalin Marinas | 79e0d9b | 2011-04-27 17:06:19 +0100 | [diff] [blame] | 549 | select DEBUG_FS |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 550 | select STACKTRACE if STACKTRACE_SUPPORT |
| 551 | select KALLSYMS |
Randy Dunlap | b60e26a | 2009-11-06 15:33:45 -0800 | [diff] [blame] | 552 | select CRC32 |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 553 | help |
| 554 | Say Y here if you want to enable the memory leak |
| 555 | detector. The memory allocation/freeing is traced in a way |
| 556 | similar to the Boehm's conservative garbage collector, the |
| 557 | difference being that the orphan objects are not freed but |
| 558 | only shown in /sys/kernel/debug/kmemleak. Enabling this |
| 559 | feature will introduce an overhead to memory |
Andreas Platschek | 700199b0 | 2016-12-14 15:05:40 -0800 | [diff] [blame] | 560 | allocations. See Documentation/dev-tools/kmemleak.rst for more |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 561 | details. |
| 562 | |
Catalin Marinas | bf96d1e | 2009-06-23 14:40:27 +0100 | [diff] [blame] | 563 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
| 564 | of finding leaks due to the slab objects poisoning. |
| 565 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 566 | In order to access the kmemleak file, debugfs needs to be |
| 567 | mounted (usually at /sys/kernel/debug). |
| 568 | |
Catalin Marinas | a9d9058 | 2009-06-25 10:16:11 +0100 | [diff] [blame] | 569 | config DEBUG_KMEMLEAK_EARLY_LOG_SIZE |
| 570 | int "Maximum kmemleak early log entries" |
| 571 | depends on DEBUG_KMEMLEAK |
Heiko Carstens | dfcc3e6 | 2009-10-06 10:33:57 +0200 | [diff] [blame] | 572 | range 200 40000 |
Catalin Marinas | a9d9058 | 2009-06-25 10:16:11 +0100 | [diff] [blame] | 573 | default 400 |
| 574 | help |
| 575 | Kmemleak must track all the memory allocations to avoid |
| 576 | reporting false positives. Since memory may be allocated or |
| 577 | freed before kmemleak is initialised, an early log buffer is |
| 578 | used to store these actions. If kmemleak reports "early log |
| 579 | buffer exceeded", please increase this value. |
| 580 | |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 581 | config DEBUG_KMEMLEAK_TEST |
| 582 | tristate "Simple test for the kernel memory leak detector" |
Daniel Baluta | 9718269 | 2011-04-04 15:06:44 -0700 | [diff] [blame] | 583 | depends on DEBUG_KMEMLEAK && m |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 584 | help |
Daniel Baluta | 9718269 | 2011-04-04 15:06:44 -0700 | [diff] [blame] | 585 | This option enables a module that explicitly leaks memory. |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 586 | |
| 587 | If unsure, say N. |
| 588 | |
Jason Baron | ab0155a | 2010-07-19 11:54:17 +0100 | [diff] [blame] | 589 | config DEBUG_KMEMLEAK_DEFAULT_OFF |
| 590 | bool "Default kmemleak to off" |
| 591 | depends on DEBUG_KMEMLEAK |
| 592 | help |
| 593 | Say Y here to disable kmemleak by default. It can then be enabled |
| 594 | on the command line via kmemleak=on. |
| 595 | |
Sri Krishna chowdary | d53ce04 | 2018-12-28 00:38:54 -0800 | [diff] [blame] | 596 | config DEBUG_KMEMLEAK_AUTO_SCAN |
| 597 | bool "Enable kmemleak auto scan thread on boot up" |
| 598 | default y |
| 599 | depends on DEBUG_KMEMLEAK |
| 600 | help |
| 601 | Depending on the cpu, kmemleak scan may be cpu intensive and can |
| 602 | stall user tasks at times. This option enables/disables automatic |
| 603 | kmemleak scan at boot up. |
| 604 | |
| 605 | Say N here to disable kmemleak auto scan thread to stop automatic |
| 606 | scanning. Disabling this option disables automatic reporting of |
| 607 | memory leaks. |
| 608 | |
| 609 | If unsure, say Y. |
| 610 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 611 | config DEBUG_STACK_USAGE |
| 612 | bool "Stack utilization instrumentation" |
Helge Deller | 6c31da3 | 2016-03-19 17:54:10 +0100 | [diff] [blame] | 613 | depends on DEBUG_KERNEL && !IA64 |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 614 | help |
| 615 | Enables the display of the minimum amount of free stack which each |
| 616 | task has ever had available in the sysrq-T and sysrq-P debug output. |
| 617 | |
| 618 | This option will slow down process creation somewhat. |
| 619 | |
| 620 | config DEBUG_VM |
| 621 | bool "Debug VM" |
| 622 | depends on DEBUG_KERNEL |
| 623 | help |
| 624 | Enable this to turn on extended checks in the virtual-memory system |
| 625 | that may impact performance. |
| 626 | |
| 627 | If unsure, say N. |
| 628 | |
Davidlohr Bueso | 4f11514 | 2014-06-04 16:06:46 -0700 | [diff] [blame] | 629 | config DEBUG_VM_VMACACHE |
| 630 | bool "Debug VMA caching" |
| 631 | depends on DEBUG_VM |
| 632 | help |
| 633 | Enable this to turn on VMA caching debug information. Doing so |
| 634 | can cause significant overhead, so only enable it in non-production |
| 635 | environments. |
| 636 | |
| 637 | If unsure, say N. |
| 638 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 639 | config DEBUG_VM_RB |
| 640 | bool "Debug VM red-black trees" |
| 641 | depends on DEBUG_VM |
| 642 | help |
Davidlohr Bueso | a663dad | 2014-04-18 15:07:22 -0700 | [diff] [blame] | 643 | Enable VM red-black tree debugging information and extra validations. |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 644 | |
| 645 | If unsure, say N. |
| 646 | |
Kirill A. Shutemov | 95ad975 | 2016-01-15 16:51:21 -0800 | [diff] [blame] | 647 | config DEBUG_VM_PGFLAGS |
| 648 | bool "Debug page-flags operations" |
| 649 | depends on DEBUG_VM |
| 650 | help |
| 651 | Enables extra validation on page flags operations. |
| 652 | |
| 653 | If unsure, say N. |
| 654 | |
Laura Abbott | fa5b6ec | 2017-01-10 13:35:40 -0800 | [diff] [blame] | 655 | config ARCH_HAS_DEBUG_VIRTUAL |
| 656 | bool |
| 657 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 658 | config DEBUG_VIRTUAL |
| 659 | bool "Debug VM translations" |
Laura Abbott | fa5b6ec | 2017-01-10 13:35:40 -0800 | [diff] [blame] | 660 | depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 661 | help |
| 662 | Enable some costly sanity checks in virtual to page code. This can |
| 663 | catch mistakes with virt_to_page() and friends. |
| 664 | |
| 665 | If unsure, say N. |
| 666 | |
| 667 | config DEBUG_NOMMU_REGIONS |
| 668 | bool "Debug the global anon/private NOMMU mapping region tree" |
| 669 | depends on DEBUG_KERNEL && !MMU |
| 670 | help |
| 671 | This option causes the global tree of anonymous and private mapping |
| 672 | regions to be regularly checked for invalid topology. |
| 673 | |
| 674 | config DEBUG_MEMORY_INIT |
| 675 | bool "Debug memory initialisation" if EXPERT |
| 676 | default !EXPERT |
| 677 | help |
| 678 | Enable this for additional checks during memory initialisation. |
| 679 | The sanity checks verify aspects of the VM such as the memory model |
| 680 | and other information provided by the architecture. Verbose |
| 681 | information will be printed at KERN_DEBUG loglevel depending |
| 682 | on the mminit_loglevel= command-line option. |
| 683 | |
| 684 | If unsure, say Y |
| 685 | |
| 686 | config MEMORY_NOTIFIER_ERROR_INJECT |
| 687 | tristate "Memory hotplug notifier error injection module" |
| 688 | depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION |
| 689 | help |
| 690 | This option provides the ability to inject artificial errors to |
| 691 | memory hotplug notifier chain callbacks. It is controlled through |
| 692 | debugfs interface under /sys/kernel/debug/notifier-error-inject/memory |
| 693 | |
| 694 | If the notifier call chain should be failed with some events |
| 695 | notified, write the error code to "actions/<notifier event>/error". |
| 696 | |
| 697 | Example: Inject memory hotplug offline error (-12 == -ENOMEM) |
| 698 | |
| 699 | # cd /sys/kernel/debug/notifier-error-inject/memory |
| 700 | # echo -12 > actions/MEM_GOING_OFFLINE/error |
| 701 | # echo offline > /sys/devices/system/memory/memoryXXX/state |
| 702 | bash: echo: write error: Cannot allocate memory |
| 703 | |
| 704 | To compile this code as a module, choose M here: the module will |
| 705 | be called memory-notifier-error-inject. |
| 706 | |
| 707 | If unsure, say N. |
| 708 | |
| 709 | config DEBUG_PER_CPU_MAPS |
| 710 | bool "Debug access to per_cpu maps" |
| 711 | depends on DEBUG_KERNEL |
| 712 | depends on SMP |
| 713 | help |
| 714 | Say Y to verify that the per_cpu map being accessed has |
| 715 | been set up. This adds a fair amount of code to kernel memory |
| 716 | and decreases performance. |
| 717 | |
| 718 | Say N if unsure. |
| 719 | |
| 720 | config DEBUG_HIGHMEM |
| 721 | bool "Highmem debugging" |
| 722 | depends on DEBUG_KERNEL && HIGHMEM |
| 723 | help |
Geert Uytterhoeven | b1357c9 | 2014-04-14 18:55:50 +0200 | [diff] [blame] | 724 | This option enables additional error checking for high memory |
| 725 | systems. Disable for production systems. |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 726 | |
| 727 | config HAVE_DEBUG_STACKOVERFLOW |
| 728 | bool |
| 729 | |
| 730 | config DEBUG_STACKOVERFLOW |
| 731 | bool "Check for stack overflows" |
| 732 | depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW |
| 733 | ---help--- |
| 734 | Say Y here if you want to check for overflows of kernel, IRQ |
Borislav Petkov | edb0ec0 | 2015-01-25 19:50:34 +0100 | [diff] [blame] | 735 | and exception stacks (if your architecture uses them). This |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 736 | option will show detailed messages if free stack space drops |
| 737 | below a certain limit. |
| 738 | |
| 739 | These kinds of bugs usually occur when call-chains in the |
| 740 | kernel get too deep, especially when interrupts are |
| 741 | involved. |
| 742 | |
| 743 | Use this in cases where you see apparently random memory |
| 744 | corruption, especially if it appears in 'struct thread_info' |
| 745 | |
| 746 | If in doubt, say "N". |
| 747 | |
Andrey Ryabinin | 0b24bec | 2015-02-13 14:39:17 -0800 | [diff] [blame] | 748 | source "lib/Kconfig.kasan" |
| 749 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 750 | endmenu # "Memory Debugging" |
| 751 | |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 752 | config ARCH_HAS_KCOV |
| 753 | bool |
| 754 | help |
| 755 | KCOV does not have any arch-specific code, but currently it is enabled |
| 756 | only for x86_64. KCOV requires testing on other archs, and most likely |
| 757 | disabling of instrumentation for some early boot code. |
| 758 | |
Masahiro Yamada | 5aadfde | 2018-05-28 18:22:04 +0900 | [diff] [blame] | 759 | config CC_HAS_SANCOV_TRACE_PC |
| 760 | def_bool $(cc-option,-fsanitize-coverage=trace-pc) |
| 761 | |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 762 | config KCOV |
| 763 | bool "Code coverage for fuzzing" |
| 764 | depends on ARCH_HAS_KCOV |
Masahiro Yamada | 5aadfde | 2018-05-28 18:22:04 +0900 | [diff] [blame] | 765 | depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 766 | select DEBUG_FS |
Masahiro Yamada | 5aadfde | 2018-05-28 18:22:04 +0900 | [diff] [blame] | 767 | select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 768 | help |
| 769 | KCOV exposes kernel code coverage information in a form suitable |
| 770 | for coverage-guided fuzzing (randomized testing). |
| 771 | |
| 772 | If RANDOMIZE_BASE is enabled, PC values will not be stable across |
| 773 | different machines and across reboots. If you need stable PC values, |
| 774 | disable RANDOMIZE_BASE. |
| 775 | |
Andreas Platschek | 700199b0 | 2016-12-14 15:05:40 -0800 | [diff] [blame] | 776 | For more details, see Documentation/dev-tools/kcov.rst. |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 777 | |
Victor Chibotaru | d677a4d | 2017-11-17 15:30:50 -0800 | [diff] [blame] | 778 | config KCOV_ENABLE_COMPARISONS |
| 779 | bool "Enable comparison operands collection by KCOV" |
| 780 | depends on KCOV |
Masahiro Yamada | 5aadfde | 2018-05-28 18:22:04 +0900 | [diff] [blame] | 781 | depends on $(cc-option,-fsanitize-coverage=trace-cmp) |
Victor Chibotaru | d677a4d | 2017-11-17 15:30:50 -0800 | [diff] [blame] | 782 | help |
| 783 | KCOV also exposes operands of every comparison in the instrumented |
| 784 | code along with operand sizes and PCs of the comparison instructions. |
| 785 | These operands can be used by fuzzing engines to improve the quality |
| 786 | of fuzzing coverage. |
| 787 | |
Vegard Nossum | a4691de | 2016-08-02 14:07:30 -0700 | [diff] [blame] | 788 | config KCOV_INSTRUMENT_ALL |
| 789 | bool "Instrument all code by default" |
| 790 | depends on KCOV |
Masahiro Yamada | 5aadfde | 2018-05-28 18:22:04 +0900 | [diff] [blame] | 791 | default y |
Vegard Nossum | a4691de | 2016-08-02 14:07:30 -0700 | [diff] [blame] | 792 | help |
| 793 | If you are doing generic system call fuzzing (like e.g. syzkaller), |
| 794 | then you will want to instrument the whole kernel and you should |
| 795 | say y here. If you are doing more targeted fuzzing (like e.g. |
| 796 | filesystem fuzzing with AFL) then you will want to enable coverage |
| 797 | for more specific subsets of files, and should say n here. |
| 798 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | config DEBUG_SHIRQ |
| 800 | bool "Debug shared IRQ handlers" |
Martin Schwidefsky | 0244ad0 | 2013-08-30 09:39:53 +0200 | [diff] [blame] | 801 | depends on DEBUG_KERNEL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | help |
| 803 | Enable this to generate a spurious interrupt as soon as a shared |
| 804 | interrupt handler is registered, and just before one is deregistered. |
| 805 | Drivers ought to be able to handle interrupts coming in at those |
| 806 | points; some don't and need to be caught. |
| 807 | |
Dave Hansen | 92aef8fb | 2013-07-01 13:04:50 -0700 | [diff] [blame] | 808 | menu "Debug Lockups and Hangs" |
| 809 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | config LOCKUP_DETECTOR |
Nicholas Piggin | 05a4a95 | 2017-07-12 14:35:46 -0700 | [diff] [blame] | 811 | bool |
| 812 | |
| 813 | config SOFTLOCKUP_DETECTOR |
| 814 | bool "Detect Soft Lockups" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | depends on DEBUG_KERNEL && !S390 |
Nicholas Piggin | 05a4a95 | 2017-07-12 14:35:46 -0700 | [diff] [blame] | 816 | select LOCKUP_DETECTOR |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | help |
| 818 | Say Y here to enable the kernel to act as a watchdog to detect |
Nicholas Piggin | 05a4a95 | 2017-07-12 14:35:46 -0700 | [diff] [blame] | 819 | soft lockups. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | |
| 821 | Softlockups are bugs that cause the kernel to loop in kernel |
| 822 | mode for more than 20 seconds, without giving other tasks a |
| 823 | chance to run. The current stack trace is displayed upon |
| 824 | detection and the system will stay locked up. |
| 825 | |
Randy Dunlap | 5f00ae0 | 2018-04-10 16:32:51 -0700 | [diff] [blame] | 826 | config BOOTPARAM_SOFTLOCKUP_PANIC |
| 827 | bool "Panic (Reboot) On Soft Lockups" |
| 828 | depends on SOFTLOCKUP_DETECTOR |
| 829 | help |
| 830 | Say Y here to enable the kernel to panic on "soft lockups", |
| 831 | which are bugs that cause the kernel to loop in kernel |
| 832 | mode for more than 20 seconds (configurable using the watchdog_thresh |
| 833 | sysctl), without giving other tasks a chance to run. |
| 834 | |
| 835 | The panic can be used in combination with panic_timeout, |
| 836 | to cause the system to reboot automatically after a |
| 837 | lockup has been detected. This feature is useful for |
| 838 | high-availability systems that have uptime guarantees and |
| 839 | where a lockup must be resolved ASAP. |
| 840 | |
| 841 | Say N if unsure. |
| 842 | |
| 843 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE |
| 844 | int |
| 845 | depends on SOFTLOCKUP_DETECTOR |
| 846 | range 0 1 |
| 847 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC |
| 848 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC |
| 849 | |
Nicholas Piggin | 05a4a95 | 2017-07-12 14:35:46 -0700 | [diff] [blame] | 850 | config HARDLOCKUP_DETECTOR_PERF |
| 851 | bool |
| 852 | select SOFTLOCKUP_DETECTOR |
| 853 | |
| 854 | # |
Thomas Gleixner | 7edaeb6 | 2017-08-15 09:50:13 +0200 | [diff] [blame] | 855 | # Enables a timestamp based low pass filter to compensate for perf based |
| 856 | # hard lockup detection which runs too fast due to turbo modes. |
| 857 | # |
| 858 | config HARDLOCKUP_CHECK_TIMESTAMP |
| 859 | bool |
| 860 | |
| 861 | # |
Nicholas Piggin | 05a4a95 | 2017-07-12 14:35:46 -0700 | [diff] [blame] | 862 | # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard |
| 863 | # lockup detector rather than the perf based detector. |
| 864 | # |
| 865 | config HARDLOCKUP_DETECTOR |
| 866 | bool "Detect Hard Lockups" |
| 867 | depends on DEBUG_KERNEL && !S390 |
| 868 | depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH |
| 869 | select LOCKUP_DETECTOR |
| 870 | select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF |
| 871 | select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH |
| 872 | help |
| 873 | Say Y here to enable the kernel to act as a watchdog to detect |
| 874 | hard lockups. |
| 875 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
| 877 | for more than 10 seconds, without letting other interrupts have a |
| 878 | chance to run. The current stack trace is displayed upon detection |
| 879 | and the system will stay locked up. |
| 880 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | config BOOTPARAM_HARDLOCKUP_PANIC |
| 882 | bool "Panic (Reboot) On Hard Lockups" |
| 883 | depends on HARDLOCKUP_DETECTOR |
| 884 | help |
| 885 | Say Y here to enable the kernel to panic on "hard lockups", |
| 886 | which are bugs that cause the kernel to loop in kernel |
| 887 | mode with interrupts disabled for more than 10 seconds (configurable |
| 888 | using the watchdog_thresh sysctl). |
| 889 | |
| 890 | Say N if unsure. |
| 891 | |
| 892 | config BOOTPARAM_HARDLOCKUP_PANIC_VALUE |
| 893 | int |
| 894 | depends on HARDLOCKUP_DETECTOR |
| 895 | range 0 1 |
| 896 | default 0 if !BOOTPARAM_HARDLOCKUP_PANIC |
| 897 | default 1 if BOOTPARAM_HARDLOCKUP_PANIC |
| 898 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | config DETECT_HUNG_TASK |
| 900 | bool "Detect Hung Tasks" |
| 901 | depends on DEBUG_KERNEL |
Nicholas Piggin | 05a4a95 | 2017-07-12 14:35:46 -0700 | [diff] [blame] | 902 | default SOFTLOCKUP_DETECTOR |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | help |
| 904 | Say Y here to enable the kernel to detect "hung tasks", |
| 905 | which are bugs that cause the task to be stuck in |
Vivien Didelot | 96b03ab | 2016-09-22 16:55:13 -0400 | [diff] [blame] | 906 | uninterruptible "D" state indefinitely. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 907 | |
| 908 | When a hung task is detected, the kernel will print the |
| 909 | current stack trace (which you should report), but the |
| 910 | task will stay in uninterruptible state. If lockdep is |
| 911 | enabled then all held locks will also be reported. This |
| 912 | feature has negligible overhead. |
| 913 | |
| 914 | config DEFAULT_HUNG_TASK_TIMEOUT |
| 915 | int "Default timeout for hung task detection (in seconds)" |
| 916 | depends on DETECT_HUNG_TASK |
| 917 | default 120 |
| 918 | help |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 919 | This option controls the default timeout (in seconds) used |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | to determine when a task has become non-responsive and should |
| 921 | be considered hung. |
| 922 | |
| 923 | It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
| 924 | sysctl or by writing a value to |
| 925 | /proc/sys/kernel/hung_task_timeout_secs. |
| 926 | |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 927 | A timeout of 0 disables the check. The default is two minutes. |
| 928 | Keeping the default should be fine in most cases. |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 929 | |
| 930 | config BOOTPARAM_HUNG_TASK_PANIC |
| 931 | bool "Panic (Reboot) On Hung Tasks" |
| 932 | depends on DETECT_HUNG_TASK |
| 933 | help |
| 934 | Say Y here to enable the kernel to panic on "hung tasks", |
| 935 | which are bugs that cause the kernel to leave a task stuck |
| 936 | in uninterruptible "D" state. |
| 937 | |
| 938 | The panic can be used in combination with panic_timeout, |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 939 | to cause the system to reboot automatically after a |
| 940 | hung task has been detected. This feature is useful for |
Roman Zippel | a1583d3 | 2006-06-27 02:55:00 -0700 | [diff] [blame] | 941 | high-availability systems that have uptime guarantees and |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 942 | where a hung tasks must be resolved ASAP. |
| 943 | |
| 944 | Say N if unsure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | |
Hugh Dickins | 048c8bc | 2006-11-01 05:44:54 +1100 | [diff] [blame] | 946 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | int |
| 948 | depends on DETECT_HUNG_TASK |
| 949 | range 0 1 |
| 950 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC |
| 951 | default 1 if BOOTPARAM_HUNG_TASK_PANIC |
| 952 | |
Tejun Heo | 82607adc | 2015-12-08 11:28:04 -0500 | [diff] [blame] | 953 | config WQ_WATCHDOG |
| 954 | bool "Detect Workqueue Stalls" |
| 955 | depends on DEBUG_KERNEL |
| 956 | help |
| 957 | Say Y here to enable stall detection on workqueues. If a |
| 958 | worker pool doesn't make forward progress on a pending work |
| 959 | item for over a given amount of time, 30s by default, a |
| 960 | warning message is printed along with dump of workqueue |
| 961 | state. This can be configured through kernel parameter |
| 962 | "workqueue.watchdog_thresh" and its sysfs counterpart. |
| 963 | |
Dave Hansen | 92aef8fb | 2013-07-01 13:04:50 -0700 | [diff] [blame] | 964 | endmenu # "Debug lockups and hangs" |
| 965 | |
| 966 | config PANIC_ON_OOPS |
| 967 | bool "Panic on Oops" |
| 968 | help |
| 969 | Say Y here to enable the kernel to panic when it oopses. This |
| 970 | has the same effect as setting oops=panic on the kernel command |
| 971 | line. |
| 972 | |
| 973 | This feature is useful to ensure that the kernel does not do |
| 974 | anything erroneous after an oops which could result in data |
| 975 | corruption or other issues. |
| 976 | |
| 977 | Say N if unsure. |
| 978 | |
| 979 | config PANIC_ON_OOPS_VALUE |
| 980 | int |
| 981 | range 0 1 |
| 982 | default 0 if !PANIC_ON_OOPS |
| 983 | default 1 if PANIC_ON_OOPS |
| 984 | |
Jason Baron | 5800dc3 | 2013-11-25 23:23:04 +0000 | [diff] [blame] | 985 | config PANIC_TIMEOUT |
| 986 | int "panic timeout" |
| 987 | default 0 |
| 988 | help |
| 989 | Set the timeout value (in seconds) until a reboot occurs when the |
| 990 | the kernel panics. If n = 0, then we wait forever. A timeout |
| 991 | value n > 0 will wait n seconds before rebooting, while a timeout |
| 992 | value n < 0 will reboot immediately. |
| 993 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | config SCHED_DEBUG |
| 995 | bool "Collect scheduler debugging info" |
| 996 | depends on DEBUG_KERNEL && PROC_FS |
| 997 | default y |
| 998 | help |
| 999 | If you say Y here, the /proc/sched_debug file will be provided |
| 1000 | that can help debug the scheduler. The runtime overhead of this |
| 1001 | option is minimal. |
| 1002 | |
Naveen N. Rao | f6db834 | 2015-06-25 23:53:37 +0530 | [diff] [blame] | 1003 | config SCHED_INFO |
| 1004 | bool |
| 1005 | default n |
| 1006 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | config SCHEDSTATS |
| 1008 | bool "Collect scheduler statistics" |
| 1009 | depends on DEBUG_KERNEL && PROC_FS |
Naveen N. Rao | f6db834 | 2015-06-25 23:53:37 +0530 | [diff] [blame] | 1010 | select SCHED_INFO |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | help |
| 1012 | If you say Y here, additional code will be inserted into the |
| 1013 | scheduler and related routines to collect statistics about |
| 1014 | scheduler behavior and provide them in /proc/schedstat. These |
| 1015 | stats may be useful for both tuning and debugging the scheduler |
| 1016 | If you aren't debugging the scheduler or trying to tune a specific |
| 1017 | application, you can say N to avoid the very slight overhead |
| 1018 | this adds. |
| 1019 | |
Aaron Tomlin | 0d9e263 | 2014-09-12 14:16:19 +0100 | [diff] [blame] | 1020 | config SCHED_STACK_END_CHECK |
| 1021 | bool "Detect stack corruption on calls to schedule()" |
| 1022 | depends on DEBUG_KERNEL |
| 1023 | default n |
| 1024 | help |
| 1025 | This option checks for a stack overrun on calls to schedule(). |
| 1026 | If the stack end location is found to be over written always panic as |
| 1027 | the content of the corrupted region can no longer be trusted. |
| 1028 | This is to ensure no erroneous behaviour occurs which could result in |
| 1029 | data corruption or a sporadic crash at a later stage once the region |
| 1030 | is examined. The runtime overhead introduced is minimal. |
| 1031 | |
John Stultz | 3c17ad1 | 2015-03-11 21:16:32 -0700 | [diff] [blame] | 1032 | config DEBUG_TIMEKEEPING |
| 1033 | bool "Enable extra timekeeping sanity checking" |
| 1034 | help |
| 1035 | This option will enable additional timekeeping sanity checks |
| 1036 | which may be helpful when diagnosing issues where timekeeping |
| 1037 | problems are suspected. |
| 1038 | |
| 1039 | This may include checks in the timekeeping hotpaths, so this |
| 1040 | option may have a (very small) performance impact to some |
| 1041 | workloads. |
| 1042 | |
| 1043 | If unsure, say N. |
| 1044 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1045 | config DEBUG_PREEMPT |
| 1046 | bool "Debug preemptible kernel" |
Kumar Gala | 01deab9 | 2009-10-16 07:21:39 +0000 | [diff] [blame] | 1047 | depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | default y |
| 1049 | help |
| 1050 | If you say Y here then the kernel will use a debug variant of the |
| 1051 | commonly used smp_processor_id() function and will print warnings |
| 1052 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
| 1053 | will detect preemption count underflows. |
| 1054 | |
Dave Hansen | 9eade16 | 2013-07-01 13:04:47 -0700 | [diff] [blame] | 1055 | menu "Lock Debugging (spinlocks, mutexes, etc...)" |
| 1056 | |
Waiman Long | f07cbeb | 2018-03-30 17:27:59 -0400 | [diff] [blame] | 1057 | config LOCK_DEBUGGING_SUPPORT |
| 1058 | bool |
| 1059 | depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
| 1060 | default y |
| 1061 | |
Waiman Long | 19193bc | 2018-03-30 17:28:00 -0400 | [diff] [blame] | 1062 | config PROVE_LOCKING |
| 1063 | bool "Lock debugging: prove locking correctness" |
| 1064 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1065 | select LOCKDEP |
| 1066 | select DEBUG_SPINLOCK |
| 1067 | select DEBUG_MUTEXES |
| 1068 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
| 1069 | select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER |
| 1070 | select DEBUG_WW_MUTEX_SLOWPATH |
| 1071 | select DEBUG_LOCK_ALLOC |
| 1072 | select TRACE_IRQFLAGS |
| 1073 | default n |
| 1074 | help |
| 1075 | This feature enables the kernel to prove that all locking |
| 1076 | that occurs in the kernel runtime is mathematically |
| 1077 | correct: that under no circumstance could an arbitrary (and |
| 1078 | not yet triggered) combination of observed locking |
| 1079 | sequences (on an arbitrary number of CPUs, running an |
| 1080 | arbitrary number of tasks and interrupt contexts) cause a |
| 1081 | deadlock. |
| 1082 | |
| 1083 | In short, this feature enables the kernel to report locking |
| 1084 | related deadlocks before they actually occur. |
| 1085 | |
| 1086 | The proof does not depend on how hard and complex a |
| 1087 | deadlock scenario would be to trigger: how many |
| 1088 | participant CPUs, tasks and irq-contexts would be needed |
| 1089 | for it to trigger. The proof also does not depend on |
| 1090 | timing: if a race and a resulting deadlock is possible |
| 1091 | theoretically (no matter how unlikely the race scenario |
| 1092 | is), it will be proven so and will immediately be |
| 1093 | reported by the kernel (once the event is observed that |
| 1094 | makes the deadlock theoretically possible). |
| 1095 | |
| 1096 | If a deadlock is impossible (i.e. the locking rules, as |
| 1097 | observed by the kernel, are mathematically correct), the |
| 1098 | kernel reports nothing. |
| 1099 | |
| 1100 | NOTE: this feature can also be enabled for rwlocks, mutexes |
| 1101 | and rwsems - in which case all dependencies between these |
| 1102 | different locking variants are observed and mapped too, and |
| 1103 | the proof of observed correctness is also maintained for an |
| 1104 | arbitrary combination of these separate locking variants. |
| 1105 | |
| 1106 | For more details, see Documentation/locking/lockdep-design.txt. |
| 1107 | |
| 1108 | config LOCK_STAT |
| 1109 | bool "Lock usage statistics" |
| 1110 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1111 | select LOCKDEP |
| 1112 | select DEBUG_SPINLOCK |
| 1113 | select DEBUG_MUTEXES |
| 1114 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
| 1115 | select DEBUG_LOCK_ALLOC |
| 1116 | default n |
| 1117 | help |
| 1118 | This feature enables tracking lock contention points |
| 1119 | |
| 1120 | For more details, see Documentation/locking/lockstat.txt |
| 1121 | |
| 1122 | This also enables lock events required by "perf lock", |
| 1123 | subcommand of perf. |
| 1124 | If you want to use "perf lock", you also need to turn on |
| 1125 | CONFIG_EVENT_TRACING. |
| 1126 | |
| 1127 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. |
| 1128 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
| 1129 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | config DEBUG_RT_MUTEXES |
| 1131 | bool "RT Mutex debugging, deadlock detection" |
| 1132 | depends on DEBUG_KERNEL && RT_MUTEXES |
| 1133 | help |
| 1134 | This allows rt mutex semantics violations and rt mutex related |
| 1135 | deadlocks (lockups) to be detected and reported automatically. |
| 1136 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | config DEBUG_SPINLOCK |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1138 | bool "Spinlock and rw-lock debugging: basic checks" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1139 | depends on DEBUG_KERNEL |
Raghavendra K T | e335e3e | 2012-03-22 15:25:08 +0530 | [diff] [blame] | 1140 | select UNINLINE_SPIN_UNLOCK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1141 | help |
| 1142 | Say Y here and build SMP to catch missing spinlock initialization |
| 1143 | and certain other kinds of spinlock errors commonly made. This is |
| 1144 | best used in conjunction with the NMI watchdog so that spinlock |
| 1145 | deadlocks are also debuggable. |
| 1146 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1147 | config DEBUG_MUTEXES |
| 1148 | bool "Mutex debugging: basic checks" |
| 1149 | depends on DEBUG_KERNEL |
| 1150 | help |
| 1151 | This feature allows mutex semantics violations to be detected and |
| 1152 | reported. |
| 1153 | |
Daniel Vetter | 2301002 | 2013-06-20 13:31:17 +0200 | [diff] [blame] | 1154 | config DEBUG_WW_MUTEX_SLOWPATH |
| 1155 | bool "Wait/wound mutex debugging: Slowpath testing" |
Waiman Long | f07cbeb | 2018-03-30 17:27:59 -0400 | [diff] [blame] | 1156 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
Daniel Vetter | 2301002 | 2013-06-20 13:31:17 +0200 | [diff] [blame] | 1157 | select DEBUG_LOCK_ALLOC |
| 1158 | select DEBUG_SPINLOCK |
| 1159 | select DEBUG_MUTEXES |
| 1160 | help |
| 1161 | This feature enables slowpath testing for w/w mutex users by |
| 1162 | injecting additional -EDEADLK wound/backoff cases. Together with |
| 1163 | the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this |
| 1164 | will test all possible w/w mutex interface abuse with the |
| 1165 | exception of simply not acquiring all the required locks. |
Rob Clark | 4d69237 | 2014-08-27 11:19:26 -0400 | [diff] [blame] | 1166 | Note that this feature can introduce significant overhead, so |
| 1167 | it really should not be enabled in a production or distro kernel, |
| 1168 | even a debug kernel. If you are a driver writer, enable it. If |
| 1169 | you are a distro, do not. |
Daniel Vetter | 2301002 | 2013-06-20 13:31:17 +0200 | [diff] [blame] | 1170 | |
Waiman Long | 5149cba | 2018-03-30 17:27:58 -0400 | [diff] [blame] | 1171 | config DEBUG_RWSEMS |
| 1172 | bool "RW Semaphore debugging: basic checks" |
| 1173 | depends on DEBUG_KERNEL && RWSEM_SPIN_ON_OWNER |
| 1174 | help |
| 1175 | This debugging feature allows mismatched rw semaphore locks and unlocks |
| 1176 | to be detected and reported. |
| 1177 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1178 | config DEBUG_LOCK_ALLOC |
| 1179 | bool "Lock debugging: detect incorrect freeing of live locks" |
Waiman Long | f07cbeb | 2018-03-30 17:27:59 -0400 | [diff] [blame] | 1180 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1181 | select DEBUG_SPINLOCK |
| 1182 | select DEBUG_MUTEXES |
Peter Zijlstra | f569478 | 2016-09-19 12:15:37 +0200 | [diff] [blame] | 1183 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1184 | select LOCKDEP |
| 1185 | help |
| 1186 | This feature will check whether any held lock (spinlock, rwlock, |
| 1187 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
| 1188 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
| 1189 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
| 1190 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
| 1191 | held during task exit. |
| 1192 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1193 | config LOCKDEP |
| 1194 | bool |
Waiman Long | f07cbeb | 2018-03-30 17:27:59 -0400 | [diff] [blame] | 1195 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1196 | select STACKTRACE |
Stefan Agner | f9b58e8 | 2018-09-30 23:02:33 +0100 | [diff] [blame] | 1197 | select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86 |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1198 | select KALLSYMS |
| 1199 | select KALLSYMS_ALL |
| 1200 | |
Daniel Jordan | 395102d | 2017-04-10 11:50:52 -0400 | [diff] [blame] | 1201 | config LOCKDEP_SMALL |
| 1202 | bool |
| 1203 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1204 | config DEBUG_LOCKDEP |
| 1205 | bool "Lock dependency engine debugging" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 1206 | depends on DEBUG_KERNEL && LOCKDEP |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1207 | help |
| 1208 | If you say Y here, the lock dependency engine will do |
| 1209 | additional runtime checks to debug itself, at the price |
| 1210 | of more runtime overhead. |
| 1211 | |
Frederic Weisbecker | d902db1 | 2011-06-08 19:31:56 +0200 | [diff] [blame] | 1212 | config DEBUG_ATOMIC_SLEEP |
| 1213 | bool "Sleep inside atomic section checking" |
Frederic Weisbecker | e8f7c70 | 2011-06-08 01:51:02 +0200 | [diff] [blame] | 1214 | select PREEMPT_COUNT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | depends on DEBUG_KERNEL |
Christoph Hellwig | 87a4c37 | 2018-07-31 13:39:32 +0200 | [diff] [blame] | 1216 | depends on !ARCH_NO_PREEMPT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | help |
| 1218 | If you say Y here, various routines which may sleep will become very |
Frederic Weisbecker | d902db1 | 2011-06-08 19:31:56 +0200 | [diff] [blame] | 1219 | noisy if they are called inside atomic sections: when a spinlock is |
| 1220 | held, inside an rcu read side critical section, inside preempt disabled |
| 1221 | sections, inside an interrupt, etc... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1222 | |
Ingo Molnar | cae2ed9 | 2006-07-03 00:24:48 -0700 | [diff] [blame] | 1223 | config DEBUG_LOCKING_API_SELFTESTS |
| 1224 | bool "Locking API boot-time self-tests" |
| 1225 | depends on DEBUG_KERNEL |
| 1226 | help |
| 1227 | Say Y here if you want the kernel to run a short self-test during |
| 1228 | bootup. The self-test checks whether common types of locking bugs |
| 1229 | are detected by debugging mechanisms or not. (if you disable |
| 1230 | lock debugging then those bugs wont be detected of course.) |
| 1231 | The following locking APIs are covered: spinlocks, rwlocks, |
| 1232 | mutexes and rwsems. |
| 1233 | |
Paul E. McKenney | 0af3fe1 | 2014-02-04 15:51:41 -0800 | [diff] [blame] | 1234 | config LOCK_TORTURE_TEST |
| 1235 | tristate "torture tests for locking" |
| 1236 | depends on DEBUG_KERNEL |
| 1237 | select TORTURE_TEST |
Paul E. McKenney | 0af3fe1 | 2014-02-04 15:51:41 -0800 | [diff] [blame] | 1238 | help |
| 1239 | This option provides a kernel module that runs torture tests |
| 1240 | on kernel locking primitives. The kernel module may be built |
| 1241 | after the fact on the running kernel to be tested, if desired. |
| 1242 | |
| 1243 | Say Y here if you want kernel locking-primitive torture tests |
| 1244 | to be built into the kernel. |
| 1245 | Say M if you want these torture tests to build as a module. |
| 1246 | Say N if you are unsure. |
| 1247 | |
Chris Wilson | f2a5fec | 2016-12-01 11:47:06 +0000 | [diff] [blame] | 1248 | config WW_MUTEX_SELFTEST |
| 1249 | tristate "Wait/wound mutex selftests" |
| 1250 | help |
| 1251 | This option provides a kernel module that runs tests on the |
| 1252 | on the struct ww_mutex locking API. |
| 1253 | |
| 1254 | It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction |
| 1255 | with this test harness. |
| 1256 | |
| 1257 | Say M if you want these self tests to build as a module. |
| 1258 | Say N if you are unsure. |
| 1259 | |
Dave Hansen | 9eade16 | 2013-07-01 13:04:47 -0700 | [diff] [blame] | 1260 | endmenu # lock debugging |
| 1261 | |
| 1262 | config TRACE_IRQFLAGS |
| 1263 | bool |
| 1264 | help |
| 1265 | Enables hooks to interrupt enabling and disabling for |
| 1266 | either tracing or lock debugging. |
| 1267 | |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 1268 | config STACKTRACE |
Dave Jones | 0c38e1f | 2014-08-29 15:18:35 -0700 | [diff] [blame] | 1269 | bool "Stack backtrace support" |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 1270 | depends on STACKTRACE_SUPPORT |
Dave Jones | 0c38e1f | 2014-08-29 15:18:35 -0700 | [diff] [blame] | 1271 | help |
| 1272 | This option causes the kernel to create a /proc/pid/stack for |
| 1273 | every process, showing its current stack trace. |
| 1274 | It is also used by various kernel debugging features that require |
| 1275 | stack trace generation. |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 1276 | |
Theodore Ts'o | eecabf5 | 2017-06-08 04:16:59 -0400 | [diff] [blame] | 1277 | config WARN_ALL_UNSEEDED_RANDOM |
| 1278 | bool "Warn for all uses of unseeded randomness" |
| 1279 | default n |
Jason A. Donenfeld | d06bfd1 | 2017-06-07 23:06:55 -0400 | [diff] [blame] | 1280 | help |
| 1281 | Some parts of the kernel contain bugs relating to their use of |
| 1282 | cryptographically secure random numbers before it's actually possible |
| 1283 | to generate those numbers securely. This setting ensures that these |
| 1284 | flaws don't go unnoticed, by enabling a message, should this ever |
| 1285 | occur. This will allow people with obscure setups to know when things |
| 1286 | are going wrong, so that they might contact developers about fixing |
| 1287 | it. |
| 1288 | |
Theodore Ts'o | eecabf5 | 2017-06-08 04:16:59 -0400 | [diff] [blame] | 1289 | Unfortunately, on some models of some architectures getting |
| 1290 | a fully seeded CRNG is extremely difficult, and so this can |
| 1291 | result in dmesg getting spammed for a surprisingly long |
| 1292 | time. This is really bad from a security perspective, and |
| 1293 | so architecture maintainers really need to do what they can |
| 1294 | to get the CRNG seeded sooner after the system is booted. |
Thibaut Sautereau | 4c5d114 | 2018-09-04 15:46:23 -0700 | [diff] [blame] | 1295 | However, since users cannot do anything actionable to |
Theodore Ts'o | eecabf5 | 2017-06-08 04:16:59 -0400 | [diff] [blame] | 1296 | address this, by default the kernel will issue only a single |
| 1297 | warning for the first use of unseeded randomness. |
| 1298 | |
| 1299 | Say Y here if you want to receive warnings for all uses of |
| 1300 | unseeded randomness. This will be of use primarily for |
Thibaut Sautereau | 4c5d114 | 2018-09-04 15:46:23 -0700 | [diff] [blame] | 1301 | those developers interested in improving the security of |
Theodore Ts'o | eecabf5 | 2017-06-08 04:16:59 -0400 | [diff] [blame] | 1302 | Linux kernels running on their architecture (or |
| 1303 | subarchitecture). |
Jason A. Donenfeld | d06bfd1 | 2017-06-07 23:06:55 -0400 | [diff] [blame] | 1304 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1305 | config DEBUG_KOBJECT |
| 1306 | bool "kobject debugging" |
| 1307 | depends on DEBUG_KERNEL |
| 1308 | help |
| 1309 | If you say Y here, some extra kobject debugging messages will be sent |
Mike Rapoport | aca52c3 | 2018-10-30 15:07:44 -0700 | [diff] [blame] | 1310 | to the syslog. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | |
Russell King | c817a67 | 2013-06-27 15:06:14 +0100 | [diff] [blame] | 1312 | config DEBUG_KOBJECT_RELEASE |
| 1313 | bool "kobject release debugging" |
Linus Torvalds | 2a999aa | 2013-10-29 08:33:36 -0700 | [diff] [blame] | 1314 | depends on DEBUG_OBJECTS_TIMERS |
Russell King | c817a67 | 2013-06-27 15:06:14 +0100 | [diff] [blame] | 1315 | help |
| 1316 | kobjects are reference counted objects. This means that their |
| 1317 | last reference count put is not predictable, and the kobject can |
| 1318 | live on past the point at which a driver decides to drop it's |
| 1319 | initial reference to the kobject gained on allocation. An |
| 1320 | example of this would be a struct device which has just been |
| 1321 | unregistered. |
| 1322 | |
| 1323 | However, some buggy drivers assume that after such an operation, |
| 1324 | the memory backing the kobject can be immediately freed. This |
| 1325 | goes completely against the principles of a refcounted object. |
| 1326 | |
| 1327 | If you say Y here, the kernel will delay the release of kobjects |
| 1328 | on the last reference count to improve the visibility of this |
| 1329 | kind of kobject release bug. |
| 1330 | |
Catalin Marinas | 9b2a60c | 2012-10-08 16:28:13 -0700 | [diff] [blame] | 1331 | config HAVE_DEBUG_BUGVERBOSE |
| 1332 | bool |
| 1333 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | config DEBUG_BUGVERBOSE |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1335 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT |
Catalin Marinas | 9b2a60c | 2012-10-08 16:28:13 -0700 | [diff] [blame] | 1336 | depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) |
Alexey Dobriyan | 8420e7e | 2009-12-14 18:00:25 -0800 | [diff] [blame] | 1337 | default y |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1338 | help |
| 1339 | Say Y here to make BUG() panics output the file name and line number |
| 1340 | of the BUG call as well as the EIP and oops trace. This aids |
| 1341 | debugging but costs about 70-100K of memory. |
| 1342 | |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 1343 | config DEBUG_LIST |
| 1344 | bool "Debug linked list manipulation" |
Arnd Bergmann | 4520bcb | 2016-08-26 17:42:00 +0200 | [diff] [blame] | 1345 | depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 1346 | help |
| 1347 | Enable this to turn on extended checks in the linked-list |
| 1348 | walking routines. |
| 1349 | |
| 1350 | If unsure, say N. |
| 1351 | |
Dan Streetman | b8cfff6 | 2014-06-04 16:11:54 -0700 | [diff] [blame] | 1352 | config DEBUG_PI_LIST |
| 1353 | bool "Debug priority linked list manipulation" |
| 1354 | depends on DEBUG_KERNEL |
| 1355 | help |
| 1356 | Enable this to turn on extended checks in the priority-ordered |
| 1357 | linked-list (plist) walking routines. This checks the entire |
| 1358 | list multiple times during each manipulation. |
| 1359 | |
| 1360 | If unsure, say N. |
| 1361 | |
Jens Axboe | d6ec084 | 2007-10-22 20:01:06 +0200 | [diff] [blame] | 1362 | config DEBUG_SG |
| 1363 | bool "Debug SG table operations" |
| 1364 | depends on DEBUG_KERNEL |
| 1365 | help |
| 1366 | Enable this to turn on checks on scatter-gather tables. This can |
| 1367 | help find problems with drivers that do not properly initialize |
| 1368 | their sg tables. |
| 1369 | |
| 1370 | If unsure, say N. |
| 1371 | |
Arjan van de Ven | 1b2439d | 2008-08-15 15:29:38 -0700 | [diff] [blame] | 1372 | config DEBUG_NOTIFIERS |
| 1373 | bool "Debug notifier call chains" |
| 1374 | depends on DEBUG_KERNEL |
| 1375 | help |
| 1376 | Enable this to turn on sanity checking for notifier call chains. |
| 1377 | This is most useful for kernel developers to make sure that |
| 1378 | modules properly unregister themselves from notifier chains. |
| 1379 | This is a relatively cheap check but if you care about maximum |
| 1380 | performance, say N. |
| 1381 | |
David Howells | e0e8173 | 2009-09-02 09:13:40 +0100 | [diff] [blame] | 1382 | config DEBUG_CREDENTIALS |
| 1383 | bool "Debug credential management" |
| 1384 | depends on DEBUG_KERNEL |
| 1385 | help |
| 1386 | Enable this to turn on some debug checking for credential |
| 1387 | management. The additional code keeps track of the number of |
| 1388 | pointers from task_structs to any given cred struct, and checks to |
| 1389 | see that this number never exceeds the usage count of the cred |
| 1390 | struct. |
| 1391 | |
| 1392 | Furthermore, if SELinux is enabled, this also checks that the |
| 1393 | security pointer in the cred struct is never seen to be invalid. |
| 1394 | |
| 1395 | If unsure, say N. |
| 1396 | |
Paul E. McKenney | 43a0a2a | 2017-05-17 09:19:44 -0700 | [diff] [blame] | 1397 | source "kernel/rcu/Kconfig.debug" |
Dave Hansen | 2f03e3c | 2013-01-07 08:19:23 -0800 | [diff] [blame] | 1398 | |
Tejun Heo | f303fccb | 2016-02-09 17:59:38 -0500 | [diff] [blame] | 1399 | config DEBUG_WQ_FORCE_RR_CPU |
| 1400 | bool "Force round-robin CPU selection for unbound work items" |
| 1401 | depends on DEBUG_KERNEL |
| 1402 | default n |
| 1403 | help |
| 1404 | Workqueue used to implicitly guarantee that work items queued |
| 1405 | without explicit CPU specified are put on the local CPU. This |
| 1406 | guarantee is no longer true and while local CPU is still |
| 1407 | preferred work items may be put on foreign CPUs. Kernel |
| 1408 | parameter "workqueue.debug_force_rr_cpu" is added to force |
| 1409 | round-robin CPU selection to flush out usages which depend on the |
| 1410 | now broken guarantee. This config option enables the debug |
| 1411 | feature by default. When enabled, memory and cache locality will |
| 1412 | be impacted. |
| 1413 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1414 | config DEBUG_BLOCK_EXT_DEVT |
| 1415 | bool "Force extended block device numbers and spread them" |
| 1416 | depends on DEBUG_KERNEL |
| 1417 | depends on BLOCK |
Jens Axboe | 759f8ca | 2008-08-29 09:06:29 +0200 | [diff] [blame] | 1418 | default n |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1419 | help |
Tejun Heo | 0e11e34 | 2008-10-13 10:46:01 +0200 | [diff] [blame] | 1420 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
| 1421 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
| 1422 | YOU ARE DOING. Distros, please enable this and fix whatever |
| 1423 | is broken. |
| 1424 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1425 | Conventionally, block device numbers are allocated from |
| 1426 | predetermined contiguous area. However, extended block area |
| 1427 | may introduce non-contiguous block device numbers. This |
| 1428 | option forces most block device numbers to be allocated from |
| 1429 | the extended space and spreads them to discover kernel or |
| 1430 | userland code paths which assume predetermined contiguous |
| 1431 | device number allocation. |
| 1432 | |
Tejun Heo | 55dc7db | 2008-09-01 13:44:35 +0200 | [diff] [blame] | 1433 | Note that turning on this debug option shuffles all the |
| 1434 | device numbers for all IDE and SCSI devices including libata |
| 1435 | ones, so root partition specified using device number |
| 1436 | directly (via rdev or root=MAJ:MIN) won't work anymore. |
| 1437 | Textual device names (root=/dev/sdXn) will continue to work. |
| 1438 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1439 | Say N if you are unsure. |
| 1440 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1441 | config CPU_HOTPLUG_STATE_CONTROL |
| 1442 | bool "Enable CPU hotplug state control" |
| 1443 | depends on DEBUG_KERNEL |
| 1444 | depends on HOTPLUG_CPU |
| 1445 | default n |
| 1446 | help |
| 1447 | Allows to write steps between "offline" and "online" to the CPUs |
| 1448 | sysfs target file so states can be stepped granular. This is a debug |
| 1449 | option for now as the hotplug machinery cannot be stopped and |
| 1450 | restarted at arbitrary points yet. |
| 1451 | |
| 1452 | Say N if your are unsure. |
| 1453 | |
Akinobu Mita | 8d43828 | 2012-07-30 14:43:02 -0700 | [diff] [blame] | 1454 | config NOTIFIER_ERROR_INJECTION |
| 1455 | tristate "Notifier error injection" |
| 1456 | depends on DEBUG_KERNEL |
| 1457 | select DEBUG_FS |
| 1458 | help |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1459 | This option provides the ability to inject artificial errors to |
Akinobu Mita | 8d43828 | 2012-07-30 14:43:02 -0700 | [diff] [blame] | 1460 | specified notifier chain callbacks. It is useful to test the error |
| 1461 | handling of notifier call chain failures. |
| 1462 | |
| 1463 | Say N if unsure. |
| 1464 | |
Akinobu Mita | 048b9c3 | 2012-07-30 14:43:07 -0700 | [diff] [blame] | 1465 | config PM_NOTIFIER_ERROR_INJECT |
| 1466 | tristate "PM notifier error injection module" |
| 1467 | depends on PM && NOTIFIER_ERROR_INJECTION |
| 1468 | default m if PM_DEBUG |
| 1469 | help |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1470 | This option provides the ability to inject artificial errors to |
Akinobu Mita | 048b9c3 | 2012-07-30 14:43:07 -0700 | [diff] [blame] | 1471 | PM notifier chain callbacks. It is controlled through debugfs |
| 1472 | interface /sys/kernel/debug/notifier-error-inject/pm |
| 1473 | |
| 1474 | If the notifier call chain should be failed with some events |
| 1475 | notified, write the error code to "actions/<notifier event>/error". |
| 1476 | |
| 1477 | Example: Inject PM suspend error (-12 = -ENOMEM) |
| 1478 | |
| 1479 | # cd /sys/kernel/debug/notifier-error-inject/pm/ |
| 1480 | # echo -12 > actions/PM_SUSPEND_PREPARE/error |
| 1481 | # echo mem > /sys/power/state |
| 1482 | bash: echo: write error: Cannot allocate memory |
| 1483 | |
| 1484 | To compile this code as a module, choose M here: the module will |
| 1485 | be called pm-notifier-error-inject. |
| 1486 | |
| 1487 | If unsure, say N. |
| 1488 | |
Benjamin Herrenschmidt | d526e85 | 2012-12-14 10:32:52 +1100 | [diff] [blame] | 1489 | config OF_RECONFIG_NOTIFIER_ERROR_INJECT |
| 1490 | tristate "OF reconfig notifier error injection module" |
| 1491 | depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1492 | help |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1493 | This option provides the ability to inject artificial errors to |
Benjamin Herrenschmidt | d526e85 | 2012-12-14 10:32:52 +1100 | [diff] [blame] | 1494 | OF reconfig notifier chain callbacks. It is controlled |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1495 | through debugfs interface under |
Benjamin Herrenschmidt | d526e85 | 2012-12-14 10:32:52 +1100 | [diff] [blame] | 1496 | /sys/kernel/debug/notifier-error-inject/OF-reconfig/ |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1497 | |
| 1498 | If the notifier call chain should be failed with some events |
| 1499 | notified, write the error code to "actions/<notifier event>/error". |
| 1500 | |
| 1501 | To compile this code as a module, choose M here: the module will |
Akinobu Mita | e12a95f | 2013-04-30 15:28:49 -0700 | [diff] [blame] | 1502 | be called of-reconfig-notifier-error-inject. |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1503 | |
| 1504 | If unsure, say N. |
| 1505 | |
Nikolay Aleksandrov | 02fff96 | 2015-11-28 13:45:28 +0100 | [diff] [blame] | 1506 | config NETDEV_NOTIFIER_ERROR_INJECT |
| 1507 | tristate "Netdev notifier error injection module" |
| 1508 | depends on NET && NOTIFIER_ERROR_INJECTION |
| 1509 | help |
| 1510 | This option provides the ability to inject artificial errors to |
| 1511 | netdevice notifier chain callbacks. It is controlled through debugfs |
| 1512 | interface /sys/kernel/debug/notifier-error-inject/netdev |
| 1513 | |
| 1514 | If the notifier call chain should be failed with some events |
| 1515 | notified, write the error code to "actions/<notifier event>/error". |
| 1516 | |
| 1517 | Example: Inject netdevice mtu change error (-22 = -EINVAL) |
| 1518 | |
| 1519 | # cd /sys/kernel/debug/notifier-error-inject/netdev |
| 1520 | # echo -22 > actions/NETDEV_CHANGEMTU/error |
| 1521 | # ip link set eth0 mtu 1024 |
| 1522 | RTNETLINK answers: Invalid argument |
| 1523 | |
| 1524 | To compile this code as a module, choose M here: the module will |
| 1525 | be called netdev-notifier-error-inject. |
| 1526 | |
| 1527 | If unsure, say N. |
| 1528 | |
Mikulas Patocka | f1b4bd0 | 2018-06-14 15:27:48 -0700 | [diff] [blame] | 1529 | config FUNCTION_ERROR_INJECTION |
| 1530 | def_bool y |
| 1531 | depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES |
| 1532 | |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1533 | config FAULT_INJECTION |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1534 | bool "Fault-injection framework" |
| 1535 | depends on DEBUG_KERNEL |
Akinobu Mita | 329409a | 2006-12-08 02:39:48 -0800 | [diff] [blame] | 1536 | help |
| 1537 | Provide fault-injection framework. |
| 1538 | For more details, see Documentation/fault-injection/. |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1539 | |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 1540 | config FAILSLAB |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1541 | bool "Fault-injection capability for kmalloc" |
| 1542 | depends on FAULT_INJECTION |
Akinobu Mita | 773ff60 | 2008-12-23 19:37:01 +0900 | [diff] [blame] | 1543 | depends on SLAB || SLUB |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 1544 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1545 | Provide fault-injection capability for kmalloc. |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 1546 | |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 1547 | config FAIL_PAGE_ALLOC |
| 1548 | bool "Fault-injection capabilitiy for alloc_pages()" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1549 | depends on FAULT_INJECTION |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 1550 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1551 | Provide fault-injection capability for alloc_pages(). |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 1552 | |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 1553 | config FAIL_MAKE_REQUEST |
Dave Jones | 86327d1 | 2006-12-12 20:16:36 +0100 | [diff] [blame] | 1554 | bool "Fault-injection capability for disk IO" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 1555 | depends on FAULT_INJECTION && BLOCK |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 1556 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1557 | Provide fault-injection capability for disk IO. |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 1558 | |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 1559 | config FAIL_IO_TIMEOUT |
Takuya Yoshikawa | f4d0143 | 2010-07-21 16:05:53 +0900 | [diff] [blame] | 1560 | bool "Fault-injection capability for faking disk interrupts" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 1561 | depends on FAULT_INJECTION && BLOCK |
| 1562 | help |
| 1563 | Provide fault-injection capability on end IO handling. This |
| 1564 | will make the block layer "forget" an interrupt as configured, |
| 1565 | thus exercising the error handling. |
| 1566 | |
| 1567 | Only works with drivers that use the generic timeout handling, |
| 1568 | for others it wont do anything. |
| 1569 | |
Davidlohr Bueso | ab51fba | 2015-06-29 23:26:02 -0700 | [diff] [blame] | 1570 | config FAIL_FUTEX |
| 1571 | bool "Fault-injection capability for futexes" |
| 1572 | select DEBUG_FS |
| 1573 | depends on FAULT_INJECTION && FUTEX |
| 1574 | help |
| 1575 | Provide fault-injection capability for futexes. |
| 1576 | |
Mikulas Patocka | f1b4bd0 | 2018-06-14 15:27:48 -0700 | [diff] [blame] | 1577 | config FAULT_INJECTION_DEBUG_FS |
| 1578 | bool "Debugfs entries for fault-injection capabilities" |
| 1579 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
| 1580 | help |
| 1581 | Enable configuration of fault-injection capabilities via debugfs. |
| 1582 | |
Masami Hiramatsu | 4b1a29a | 2018-01-13 02:56:03 +0900 | [diff] [blame] | 1583 | config FAIL_FUNCTION |
| 1584 | bool "Fault-injection capability for functions" |
| 1585 | depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION |
| 1586 | help |
| 1587 | Provide function-based fault-injection capability. |
| 1588 | This will allow you to override a specific function with a return |
| 1589 | with given return value. As a result, function caller will see |
| 1590 | an error value and have to handle it. This is useful to test the |
| 1591 | error handling in various subsystems. |
| 1592 | |
Mikulas Patocka | f1b4bd0 | 2018-06-14 15:27:48 -0700 | [diff] [blame] | 1593 | config FAIL_MMC_REQUEST |
| 1594 | bool "Fault-injection capability for MMC IO" |
| 1595 | depends on FAULT_INJECTION_DEBUG_FS && MMC |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1596 | help |
Mikulas Patocka | f1b4bd0 | 2018-06-14 15:27:48 -0700 | [diff] [blame] | 1597 | Provide fault-injection capability for MMC IO. |
| 1598 | This will make the mmc core return data errors. This is |
| 1599 | useful to test the error handling in the mmc block device |
| 1600 | and to test how the mmc host driver handles retries from |
| 1601 | the block device. |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 1602 | |
| 1603 | config FAULT_INJECTION_STACKTRACE_FILTER |
| 1604 | bool "stacktrace filter for fault-injection capabilities" |
| 1605 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
Akinobu Mita | 6d690dc | 2007-05-12 10:36:53 -0700 | [diff] [blame] | 1606 | depends on !X86_64 |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 1607 | select STACKTRACE |
Stefan Agner | f9b58e8 | 2018-09-30 23:02:33 +0100 | [diff] [blame] | 1608 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 1609 | help |
| 1610 | Provide stacktrace filter for fault-injection capabilities |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 1611 | |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1612 | config LATENCYTOP |
| 1613 | bool "Latency measuring infrastructure" |
Randy Dunlap | 625fdca | 2010-08-12 12:31:21 -0700 | [diff] [blame] | 1614 | depends on DEBUG_KERNEL |
| 1615 | depends on STACKTRACE_SUPPORT |
| 1616 | depends on PROC_FS |
Stefan Agner | f9b58e8 | 2018-09-30 23:02:33 +0100 | [diff] [blame] | 1617 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1618 | select KALLSYMS |
| 1619 | select KALLSYMS_ALL |
| 1620 | select STACKTRACE |
| 1621 | select SCHEDSTATS |
| 1622 | select SCHED_DEBUG |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1623 | help |
| 1624 | Enable this option if you want to use the LatencyTOP tool |
| 1625 | to find out which userspace is blocking on what kernel operations. |
| 1626 | |
Masahiro Yamada | 8636a1f | 2018-12-11 20:01:04 +0900 | [diff] [blame] | 1627 | source "kernel/trace/Kconfig" |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1628 | |
Randy Dunlap | cc3fa84 | 2017-10-13 15:57:33 -0700 | [diff] [blame] | 1629 | config PROVIDE_OHCI1394_DMA_INIT |
| 1630 | bool "Remote debugging over FireWire early on boot" |
| 1631 | depends on PCI && X86 |
| 1632 | help |
| 1633 | If you want to debug problems which hang or crash the kernel early |
| 1634 | on boot and the crashing machine has a FireWire port, you can use |
| 1635 | this feature to remotely access the memory of the crashed machine |
| 1636 | over FireWire. This employs remote DMA as part of the OHCI1394 |
| 1637 | specification which is now the standard for FireWire controllers. |
| 1638 | |
| 1639 | With remote DMA, you can monitor the printk buffer remotely using |
| 1640 | firescope and access all memory below 4GB using fireproxy from gdb. |
| 1641 | Even controlling a kernel debugger is possible using remote DMA. |
| 1642 | |
| 1643 | Usage: |
| 1644 | |
| 1645 | If ohci1394_dma=early is used as boot parameter, it will initialize |
| 1646 | all OHCI1394 controllers which are found in the PCI config space. |
| 1647 | |
| 1648 | As all changes to the FireWire bus such as enabling and disabling |
| 1649 | devices cause a bus reset and thereby disable remote DMA for all |
| 1650 | devices, be sure to have the cable plugged and FireWire enabled on |
| 1651 | the debugging host before booting the debug target for debugging. |
| 1652 | |
| 1653 | This code (~1k) is freed after boot. By then, the firewire stack |
| 1654 | in charge of the OHCI-1394 controllers should be used instead. |
| 1655 | |
| 1656 | See Documentation/debugging-via-ohci1394.txt for more information. |
| 1657 | |
| 1658 | config DMA_API_DEBUG |
| 1659 | bool "Enable debugging of DMA-API usage" |
Christoph Hellwig | f616ab5 | 2018-05-09 06:53:49 +0200 | [diff] [blame] | 1660 | select NEED_DMA_MAP_STATE |
Randy Dunlap | cc3fa84 | 2017-10-13 15:57:33 -0700 | [diff] [blame] | 1661 | help |
| 1662 | Enable this option to debug the use of the DMA API by device drivers. |
| 1663 | With this option you will be able to detect common bugs in device |
| 1664 | drivers like double-freeing of DMA mappings or freeing mappings that |
| 1665 | were never allocated. |
| 1666 | |
| 1667 | This also attempts to catch cases where a page owned by DMA is |
| 1668 | accessed by the cpu in a way that could cause data corruption. For |
| 1669 | example, this enables cow_user_page() to check that the source page is |
| 1670 | not undergoing DMA. |
| 1671 | |
| 1672 | This option causes a performance degradation. Use only if you want to |
| 1673 | debug device drivers and dma interactions. |
| 1674 | |
| 1675 | If unsure, say N. |
| 1676 | |
Robin Murphy | 78c4783 | 2018-05-21 12:35:13 +0100 | [diff] [blame] | 1677 | config DMA_API_DEBUG_SG |
| 1678 | bool "Debug DMA scatter-gather usage" |
| 1679 | default y |
| 1680 | depends on DMA_API_DEBUG |
| 1681 | help |
| 1682 | Perform extra checking that callers of dma_map_sg() have respected the |
| 1683 | appropriate segment length/boundary limits for the given device when |
| 1684 | preparing DMA scatterlists. |
| 1685 | |
| 1686 | This is particularly likely to have been overlooked in cases where the |
| 1687 | dma_map_sg() API is used for general bulk mapping of pages rather than |
| 1688 | preparing literal scatter-gather descriptors, where there is a risk of |
| 1689 | unexpected behaviour from DMA API implementations if the scatterlist |
| 1690 | is technically out-of-spec. |
| 1691 | |
| 1692 | If unsure, say N. |
| 1693 | |
Vincent Legoll | d3deafa | 2018-02-06 15:38:38 -0800 | [diff] [blame] | 1694 | menuconfig RUNTIME_TESTING_MENU |
| 1695 | bool "Runtime Testing" |
Anders Roxell | 908009e8 | 2018-02-21 14:46:05 -0800 | [diff] [blame] | 1696 | def_bool y |
Vincent Legoll | d3deafa | 2018-02-06 15:38:38 -0800 | [diff] [blame] | 1697 | |
| 1698 | if RUNTIME_TESTING_MENU |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1699 | |
| 1700 | config LKDTM |
| 1701 | tristate "Linux Kernel Dump Test Tool Module" |
| 1702 | depends on DEBUG_FS |
| 1703 | depends on BLOCK |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1704 | help |
| 1705 | This module enables testing of the different dumping mechanisms by |
| 1706 | inducing system failures at predefined crash points. |
| 1707 | If you don't need it: say N |
| 1708 | Choose M here to compile this code as a module. The module will be |
| 1709 | called lkdtm. |
| 1710 | |
| 1711 | Documentation on how to use the module can be found in |
| 1712 | Documentation/fault-injection/provoke-crashes.txt |
| 1713 | |
| 1714 | config TEST_LIST_SORT |
Geert Uytterhoeven | e327fd7 | 2017-05-08 15:55:26 -0700 | [diff] [blame] | 1715 | tristate "Linked list sorting test" |
| 1716 | depends on DEBUG_KERNEL || m |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1717 | help |
| 1718 | Enable this to turn on 'list_sort()' function test. This test is |
Geert Uytterhoeven | e327fd7 | 2017-05-08 15:55:26 -0700 | [diff] [blame] | 1719 | executed only once during system boot (so affects only boot time), |
| 1720 | or at module load time. |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1721 | |
| 1722 | If unsure, say N. |
| 1723 | |
Kostenzer Felix | c5adae9 | 2017-02-24 15:01:07 -0800 | [diff] [blame] | 1724 | config TEST_SORT |
Geert Uytterhoeven | 5c4e679 | 2017-05-08 15:55:23 -0700 | [diff] [blame] | 1725 | tristate "Array-based sort test" |
| 1726 | depends on DEBUG_KERNEL || m |
Kostenzer Felix | c5adae9 | 2017-02-24 15:01:07 -0800 | [diff] [blame] | 1727 | help |
Geert Uytterhoeven | 5c4e679 | 2017-05-08 15:55:23 -0700 | [diff] [blame] | 1728 | This option enables the self-test function of 'sort()' at boot, |
| 1729 | or at module load time. |
Kostenzer Felix | c5adae9 | 2017-02-24 15:01:07 -0800 | [diff] [blame] | 1730 | |
| 1731 | If unsure, say N. |
| 1732 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1733 | config KPROBES_SANITY_TEST |
| 1734 | bool "Kprobes sanity tests" |
| 1735 | depends on DEBUG_KERNEL |
| 1736 | depends on KPROBES |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1737 | help |
| 1738 | This option provides for testing basic kprobes functionality on |
Masami Hiramatsu | 5a6cf77 | 2018-06-20 01:05:07 +0900 | [diff] [blame] | 1739 | boot. Samples of kprobe and kretprobe are inserted and |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1740 | verified for functionality. |
| 1741 | |
| 1742 | Say N if you are unsure. |
| 1743 | |
| 1744 | config BACKTRACE_SELF_TEST |
| 1745 | tristate "Self test for the backtrace code" |
| 1746 | depends on DEBUG_KERNEL |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1747 | help |
| 1748 | This option provides a kernel module that can be used to test |
| 1749 | the kernel stack backtrace code. This option is not useful |
| 1750 | for distributions or general kernels, but only for kernel |
| 1751 | developers working on architecture code. |
| 1752 | |
| 1753 | Note that if you want to also test saved backtraces, you will |
| 1754 | have to enable STACKTRACE as well. |
| 1755 | |
| 1756 | Say N if you are unsure. |
| 1757 | |
Michel Lespinasse | 910a742 | 2012-10-08 16:30:39 -0700 | [diff] [blame] | 1758 | config RBTREE_TEST |
| 1759 | tristate "Red-Black tree test" |
Cody P Schafer | 7c993e1 | 2013-09-11 14:25:19 -0700 | [diff] [blame] | 1760 | depends on DEBUG_KERNEL |
Michel Lespinasse | 910a742 | 2012-10-08 16:30:39 -0700 | [diff] [blame] | 1761 | help |
| 1762 | A benchmark measuring the performance of the rbtree library. |
| 1763 | Also includes rbtree invariant checks. |
| 1764 | |
Michel Lespinasse | fff3fd8 | 2012-10-08 16:31:23 -0700 | [diff] [blame] | 1765 | config INTERVAL_TREE_TEST |
| 1766 | tristate "Interval tree test" |
Davidlohr Bueso | 0f789b6 | 2017-07-10 15:51:43 -0700 | [diff] [blame] | 1767 | depends on DEBUG_KERNEL |
Chris Wilson | a88cc10 | 2014-03-17 12:21:54 +0000 | [diff] [blame] | 1768 | select INTERVAL_TREE |
Michel Lespinasse | fff3fd8 | 2012-10-08 16:31:23 -0700 | [diff] [blame] | 1769 | help |
| 1770 | A benchmark measuring the performance of the interval tree library |
| 1771 | |
Greg Thelen | 623fd80 | 2013-11-12 15:08:34 -0800 | [diff] [blame] | 1772 | config PERCPU_TEST |
| 1773 | tristate "Per cpu operations test" |
| 1774 | depends on m && DEBUG_KERNEL |
| 1775 | help |
| 1776 | Enable this option to build test module which validates per-cpu |
| 1777 | operations. |
| 1778 | |
| 1779 | If unsure, say N. |
| 1780 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1781 | config ATOMIC64_SELFTEST |
Geert Uytterhoeven | 55ded95 | 2017-02-24 15:00:55 -0800 | [diff] [blame] | 1782 | tristate "Perform an atomic64_t self-test" |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1783 | help |
Geert Uytterhoeven | 55ded95 | 2017-02-24 15:00:55 -0800 | [diff] [blame] | 1784 | Enable this option to test the atomic64_t functions at boot or |
| 1785 | at module load time. |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1786 | |
| 1787 | If unsure, say N. |
| 1788 | |
| 1789 | config ASYNC_RAID6_TEST |
| 1790 | tristate "Self test for hardware accelerated raid6 recovery" |
| 1791 | depends on ASYNC_RAID6_RECOV |
| 1792 | select ASYNC_MEMCPY |
| 1793 | ---help--- |
| 1794 | This is a one-shot self test that permutes through the |
| 1795 | recovery of all the possible two disk failure scenarios for a |
| 1796 | N-disk array. Recovery is performed with the asynchronous |
| 1797 | raid6 recovery routines, and will optionally use an offload |
| 1798 | engine if one is available. |
| 1799 | |
| 1800 | If unsure, say N. |
| 1801 | |
Andy Shevchenko | 64d1d77 | 2015-02-12 15:02:21 -0800 | [diff] [blame] | 1802 | config TEST_HEXDUMP |
| 1803 | tristate "Test functions located in the hexdump module at runtime" |
| 1804 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1805 | config TEST_STRING_HELPERS |
| 1806 | tristate "Test functions located in the string_helpers module at runtime" |
| 1807 | |
| 1808 | config TEST_KSTRTOX |
| 1809 | tristate "Test kstrto*() family of functions at runtime" |
| 1810 | |
Rasmus Villemoes | 707cc72 | 2015-11-06 16:30:29 -0800 | [diff] [blame] | 1811 | config TEST_PRINTF |
| 1812 | tristate "Test printf() family of functions at runtime" |
| 1813 | |
David Decotigny | 5fd003f | 2016-02-19 09:24:00 -0500 | [diff] [blame] | 1814 | config TEST_BITMAP |
| 1815 | tristate "Test bitmap_*() family of functions at runtime" |
David Decotigny | 5fd003f | 2016-02-19 09:24:00 -0500 | [diff] [blame] | 1816 | help |
| 1817 | Enable this option to test the bitmap functions at boot. |
| 1818 | |
| 1819 | If unsure, say N. |
| 1820 | |
Johannes Berg | 0e2dc70 | 2018-06-20 08:58:30 +0200 | [diff] [blame] | 1821 | config TEST_BITFIELD |
| 1822 | tristate "Test bitfield functions at runtime" |
| 1823 | help |
| 1824 | Enable this option to test the bitfield functions at boot. |
| 1825 | |
| 1826 | If unsure, say N. |
| 1827 | |
Andy Shevchenko | cfaff0e | 2016-05-30 17:40:41 +0300 | [diff] [blame] | 1828 | config TEST_UUID |
| 1829 | tristate "Test functions located in the uuid module at runtime" |
| 1830 | |
Matthew Wilcox | ad3d6c7 | 2017-11-07 14:57:46 -0500 | [diff] [blame] | 1831 | config TEST_XARRAY |
| 1832 | tristate "Test the XArray code at runtime" |
| 1833 | |
Rasmus Villemoes | 455a35a | 2018-05-08 00:36:28 +0200 | [diff] [blame] | 1834 | config TEST_OVERFLOW |
| 1835 | tristate "Test check_*_overflow() functions at runtime" |
| 1836 | |
Thomas Graf | 7e1e776 | 2014-08-02 11:47:44 +0200 | [diff] [blame] | 1837 | config TEST_RHASHTABLE |
Geert Uytterhoeven | 9d6dbe1 | 2015-01-29 15:40:25 +0100 | [diff] [blame] | 1838 | tristate "Perform selftest on resizable hash table" |
Thomas Graf | 7e1e776 | 2014-08-02 11:47:44 +0200 | [diff] [blame] | 1839 | help |
| 1840 | Enable this option to test the rhashtable functions at boot. |
| 1841 | |
| 1842 | If unsure, say N. |
| 1843 | |
George Spelvin | 468a942 | 2016-05-26 22:11:51 -0400 | [diff] [blame] | 1844 | config TEST_HASH |
| 1845 | tristate "Perform selftest on hash functions" |
George Spelvin | 468a942 | 2016-05-26 22:11:51 -0400 | [diff] [blame] | 1846 | help |
Jason A. Donenfeld | 2c956a6 | 2017-01-08 13:54:00 +0100 | [diff] [blame] | 1847 | Enable this option to test the kernel's integer (<linux/hash.h>), |
| 1848 | string (<linux/stringhash.h>), and siphash (<linux/siphash.h>) |
| 1849 | hash functions on boot (or module load). |
George Spelvin | 468a942 | 2016-05-26 22:11:51 -0400 | [diff] [blame] | 1850 | |
| 1851 | This is intended to help people writing architecture-specific |
| 1852 | optimized versions. If unsure, say N. |
| 1853 | |
Matthew Wilcox | 8ab8ba3 | 2018-06-18 16:59:29 -0400 | [diff] [blame] | 1854 | config TEST_IDA |
| 1855 | tristate "Perform selftest on IDA functions" |
| 1856 | |
Jiri Pirko | 44091d2 | 2017-02-03 10:29:06 +0100 | [diff] [blame] | 1857 | config TEST_PARMAN |
| 1858 | tristate "Perform selftest on priority array manager" |
Jiri Pirko | 44091d2 | 2017-02-03 10:29:06 +0100 | [diff] [blame] | 1859 | depends on PARMAN |
| 1860 | help |
| 1861 | Enable this option to test priority array manager on boot |
| 1862 | (or module load). |
| 1863 | |
| 1864 | If unsure, say N. |
| 1865 | |
Valentin Rothberg | 8a6f0b4 | 2014-10-13 15:51:38 -0700 | [diff] [blame] | 1866 | config TEST_LKM |
Kees Cook | 93e9ef8 | 2014-01-23 15:54:37 -0800 | [diff] [blame] | 1867 | tristate "Test module loading with 'hello world' module" |
Kees Cook | 93e9ef8 | 2014-01-23 15:54:37 -0800 | [diff] [blame] | 1868 | depends on m |
| 1869 | help |
| 1870 | This builds the "test_module" module that emits "Hello, world" |
| 1871 | on printk when loaded. It is designed to be used for basic |
| 1872 | evaluation of the module loading subsystem (for example when |
| 1873 | validating module verification). It lacks any extra dependencies, |
| 1874 | and will not normally be loaded by the system unless explicitly |
| 1875 | requested by name. |
| 1876 | |
| 1877 | If unsure, say N. |
| 1878 | |
Kees Cook | 3e2a4c1 | 2014-01-23 15:54:38 -0800 | [diff] [blame] | 1879 | config TEST_USER_COPY |
| 1880 | tristate "Test user/kernel boundary protections" |
Kees Cook | 3e2a4c1 | 2014-01-23 15:54:38 -0800 | [diff] [blame] | 1881 | depends on m |
| 1882 | help |
| 1883 | This builds the "test_user_copy" module that runs sanity checks |
| 1884 | on the copy_to/from_user infrastructure, making sure basic |
| 1885 | user/kernel boundary testing is working. If it fails to load, |
| 1886 | a regression has been detected in the user/kernel memory boundary |
| 1887 | protections. |
| 1888 | |
| 1889 | If unsure, say N. |
| 1890 | |
Alexei Starovoitov | 64a8946 | 2014-05-08 14:10:52 -0700 | [diff] [blame] | 1891 | config TEST_BPF |
| 1892 | tristate "Test BPF filter functionality" |
Randy Dunlap | 98920ba | 2014-05-13 09:58:44 -0700 | [diff] [blame] | 1893 | depends on m && NET |
Alexei Starovoitov | 64a8946 | 2014-05-08 14:10:52 -0700 | [diff] [blame] | 1894 | help |
| 1895 | This builds the "test_bpf" module that runs various test vectors |
| 1896 | against the BPF interpreter or BPF JIT compiler depending on the |
| 1897 | current setting. This is in particular useful for BPF JIT compiler |
| 1898 | development, but also to run regression tests against changes in |
Alexei Starovoitov | 3c731eb | 2014-09-26 00:17:07 -0700 | [diff] [blame] | 1899 | the interpreter code. It also enables test stubs for eBPF maps and |
| 1900 | verifier used by user space verifier testsuite. |
Alexei Starovoitov | 64a8946 | 2014-05-08 14:10:52 -0700 | [diff] [blame] | 1901 | |
| 1902 | If unsure, say N. |
| 1903 | |
Yury Norov | dceeb3e | 2018-02-06 15:38:27 -0800 | [diff] [blame] | 1904 | config FIND_BIT_BENCHMARK |
Yury Norov | 4441fca | 2017-11-17 15:28:31 -0800 | [diff] [blame] | 1905 | tristate "Test find_bit functions" |
Yury Norov | 4441fca | 2017-11-17 15:28:31 -0800 | [diff] [blame] | 1906 | help |
| 1907 | This builds the "test_find_bit" module that measure find_*_bit() |
| 1908 | functions performance. |
| 1909 | |
| 1910 | If unsure, say N. |
| 1911 | |
Kees Cook | 0a8adf5 | 2014-07-14 14:38:12 -0700 | [diff] [blame] | 1912 | config TEST_FIRMWARE |
| 1913 | tristate "Test firmware loading via userspace interface" |
Kees Cook | 0a8adf5 | 2014-07-14 14:38:12 -0700 | [diff] [blame] | 1914 | depends on FW_LOADER |
| 1915 | help |
| 1916 | This builds the "test_firmware" module that creates a userspace |
| 1917 | interface for testing firmware loading. This can be used to |
| 1918 | control the triggering of firmware loading without needing an |
| 1919 | actual firmware-using device. The contents can be rechecked by |
| 1920 | userspace. |
| 1921 | |
| 1922 | If unsure, say N. |
| 1923 | |
Luis R. Rodriguez | 9308f2f | 2017-07-12 14:33:43 -0700 | [diff] [blame] | 1924 | config TEST_SYSCTL |
| 1925 | tristate "sysctl test driver" |
Luis R. Rodriguez | 9308f2f | 2017-07-12 14:33:43 -0700 | [diff] [blame] | 1926 | depends on PROC_SYSCTL |
| 1927 | help |
| 1928 | This builds the "test_sysctl" module. This driver enables to test the |
| 1929 | proc sysctl interfaces available to drivers safely without affecting |
| 1930 | production knobs which might alter system functionality. |
| 1931 | |
| 1932 | If unsure, say N. |
| 1933 | |
David Riley | e704f93 | 2014-06-16 14:58:32 -0700 | [diff] [blame] | 1934 | config TEST_UDELAY |
| 1935 | tristate "udelay test driver" |
David Riley | e704f93 | 2014-06-16 14:58:32 -0700 | [diff] [blame] | 1936 | help |
| 1937 | This builds the "udelay_test" module that helps to make sure |
| 1938 | that udelay() is working properly. |
| 1939 | |
| 1940 | If unsure, say N. |
| 1941 | |
Ingo Molnar | 2bf9e0a | 2015-08-03 11:42:57 +0200 | [diff] [blame] | 1942 | config TEST_STATIC_KEYS |
| 1943 | tristate "Test static keys" |
Jason Baron | 579e1ac | 2015-07-30 03:59:44 +0000 | [diff] [blame] | 1944 | depends on m |
| 1945 | help |
Ingo Molnar | 2bf9e0a | 2015-08-03 11:42:57 +0200 | [diff] [blame] | 1946 | Test the static key interfaces. |
Jason Baron | 579e1ac | 2015-07-30 03:59:44 +0000 | [diff] [blame] | 1947 | |
| 1948 | If unsure, say N. |
| 1949 | |
Luis R. Rodriguez | d9c6a72 | 2017-07-14 14:50:08 -0700 | [diff] [blame] | 1950 | config TEST_KMOD |
| 1951 | tristate "kmod stress tester" |
Luis R. Rodriguez | d9c6a72 | 2017-07-14 14:50:08 -0700 | [diff] [blame] | 1952 | depends on m |
| 1953 | depends on BLOCK && (64BIT || LBDAF) # for XFS, BTRFS |
| 1954 | depends on NETDEVICES && NET_CORE && INET # for TUN |
| 1955 | select TEST_LKM |
| 1956 | select XFS_FS |
| 1957 | select TUN |
| 1958 | select BTRFS_FS |
| 1959 | help |
| 1960 | Test the kernel's module loading mechanism: kmod. kmod implements |
| 1961 | support to load modules using the Linux kernel's usermode helper. |
| 1962 | This test provides a series of tests against kmod. |
| 1963 | |
| 1964 | Although technically you can either build test_kmod as a module or |
| 1965 | into the kernel we disallow building it into the kernel since |
| 1966 | it stress tests request_module() and this will very likely cause |
| 1967 | some issues by taking over precious threads available from other |
| 1968 | module load requests, ultimately this could be fatal. |
| 1969 | |
| 1970 | To run tests run: |
| 1971 | |
| 1972 | tools/testing/selftests/kmod/kmod.sh --help |
| 1973 | |
| 1974 | If unsure, say N. |
| 1975 | |
Florian Fainelli | e4dace3 | 2017-09-08 16:15:31 -0700 | [diff] [blame] | 1976 | config TEST_DEBUG_VIRTUAL |
| 1977 | tristate "Test CONFIG_DEBUG_VIRTUAL feature" |
| 1978 | depends on DEBUG_VIRTUAL |
| 1979 | help |
| 1980 | Test the kernel's ability to detect incorrect calls to |
| 1981 | virt_to_phys() done against the non-linear part of the |
| 1982 | kernel's virtual address map. |
| 1983 | |
| 1984 | If unsure, say N. |
| 1985 | |
Alexander Shishkin | ce76d93 | 2018-10-05 15:43:05 +0300 | [diff] [blame] | 1986 | config TEST_MEMCAT_P |
| 1987 | tristate "Test memcat_p() helper function" |
| 1988 | help |
| 1989 | Test the memcat_p() helper for correctly merging two |
| 1990 | pointer arrays together. |
| 1991 | |
| 1992 | If unsure, say N. |
| 1993 | |
Jiri Pirko | 0a020d4 | 2018-11-14 08:22:28 +0000 | [diff] [blame] | 1994 | config TEST_OBJAGG |
| 1995 | tristate "Perform selftest on object aggreration manager" |
| 1996 | default n |
| 1997 | depends on OBJAGG |
| 1998 | help |
| 1999 | Enable this option to test object aggregation manager on boot |
| 2000 | (or module load). |
| 2001 | |
| 2002 | If unsure, say N. |
| 2003 | |
Vincent Legoll | d3deafa | 2018-02-06 15:38:38 -0800 | [diff] [blame] | 2004 | endif # RUNTIME_TESTING_MENU |
Randy Dunlap | cc3fa84 | 2017-10-13 15:57:33 -0700 | [diff] [blame] | 2005 | |
| 2006 | config MEMTEST |
| 2007 | bool "Memtest" |
Randy Dunlap | cc3fa84 | 2017-10-13 15:57:33 -0700 | [diff] [blame] | 2008 | ---help--- |
| 2009 | This option adds a kernel parameter 'memtest', which allows memtest |
| 2010 | to be set. |
| 2011 | memtest=0, mean disabled; -- default |
| 2012 | memtest=1, mean do 1 test pattern; |
| 2013 | ... |
| 2014 | memtest=17, mean do 17 test patterns. |
| 2015 | If you are unsure how to answer this question, answer N. |
| 2016 | |
| 2017 | config BUG_ON_DATA_CORRUPTION |
| 2018 | bool "Trigger a BUG when data corruption is detected" |
| 2019 | select DEBUG_LIST |
| 2020 | help |
| 2021 | Select this option if the kernel should BUG when it encounters |
| 2022 | data corruption in kernel memory structures when they get checked |
| 2023 | for validity. |
| 2024 | |
| 2025 | If unsure, say N. |
Florian Fainelli | e4dace3 | 2017-09-08 16:15:31 -0700 | [diff] [blame] | 2026 | |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 2027 | source "samples/Kconfig" |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 2028 | |
| 2029 | source "lib/Kconfig.kgdb" |
Pekka Enberg | 0a4af3b | 2009-02-26 21:38:56 +0200 | [diff] [blame] | 2030 | |
Andrey Ryabinin | c6d3085 | 2016-01-20 15:00:55 -0800 | [diff] [blame] | 2031 | source "lib/Kconfig.ubsan" |
| 2032 | |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2033 | config ARCH_HAS_DEVMEM_IS_ALLOWED |
| 2034 | bool |
| 2035 | |
| 2036 | config STRICT_DEVMEM |
| 2037 | bool "Filter access to /dev/mem" |
Dave Young | 6b2a65c | 2016-12-12 16:46:14 -0800 | [diff] [blame] | 2038 | depends on MMU && DEVMEM |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2039 | depends on ARCH_HAS_DEVMEM_IS_ALLOWED |
Arnd Bergmann | a687a53 | 2018-03-07 23:30:54 +0100 | [diff] [blame] | 2040 | default y if PPC || X86 || ARM64 |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2041 | ---help--- |
| 2042 | If this option is disabled, you allow userspace (root) access to all |
| 2043 | of memory, including kernel and userspace memory. Accidental |
| 2044 | access to this is obviously disastrous, but specific access can |
| 2045 | be used by people debugging the kernel. Note that with PAT support |
| 2046 | enabled, even in this case there are restrictions on /dev/mem |
| 2047 | use due to the cache aliasing requirements. |
| 2048 | |
Dan Williams | 90a545e | 2015-11-23 15:49:03 -0800 | [diff] [blame] | 2049 | If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem |
| 2050 | file only allows userspace access to PCI space and the BIOS code and |
| 2051 | data regions. This is sufficient for dosemu and X and all common |
| 2052 | users of /dev/mem. |
| 2053 | |
| 2054 | If in doubt, say Y. |
| 2055 | |
| 2056 | config IO_STRICT_DEVMEM |
| 2057 | bool "Filter I/O access to /dev/mem" |
| 2058 | depends on STRICT_DEVMEM |
Dan Williams | 90a545e | 2015-11-23 15:49:03 -0800 | [diff] [blame] | 2059 | ---help--- |
| 2060 | If this option is disabled, you allow userspace (root) access to all |
| 2061 | io-memory regardless of whether a driver is actively using that |
| 2062 | range. Accidental access to this is obviously disastrous, but |
| 2063 | specific access can be used by people debugging kernel drivers. |
| 2064 | |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2065 | If this option is switched on, the /dev/mem file only allows |
Dan Williams | 90a545e | 2015-11-23 15:49:03 -0800 | [diff] [blame] | 2066 | userspace access to *idle* io-memory ranges (see /proc/iomem) This |
| 2067 | may break traditional users of /dev/mem (dosemu, legacy X, etc...) |
| 2068 | if the driver using a given range cannot be disabled. |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2069 | |
| 2070 | If in doubt, say Y. |
Christoph Hellwig | 06ec64b | 2018-07-31 13:39:31 +0200 | [diff] [blame] | 2071 | |
| 2072 | source "arch/$(SRCARCH)/Kconfig.debug" |
| 2073 | |
| 2074 | endmenu # Kernel hacking |