Dave Hansen | 604ff0d | 2013-07-01 13:04:49 -0700 | [diff] [blame] | 1 | menu "printk and dmesg options" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | |
| 3 | config PRINTK_TIME |
| 4 | bool "Show timing information on printks" |
Randy Dunlap | d3b8b6e | 2006-12-06 20:36:38 -0800 | [diff] [blame] | 5 | depends on PRINTK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | help |
Kay Sievers | 649e6ee | 2012-05-10 04:30:45 +0200 | [diff] [blame] | 7 | Selecting this option causes time stamps of the printk() |
| 8 | messages to be added to the output of the syslog() system |
| 9 | call and at the console. |
| 10 | |
| 11 | The timestamp is always recorded internally, and exported |
| 12 | to /dev/kmsg. This flag just specifies if the timestamp should |
| 13 | be included, not that the timestamp is recorded. |
| 14 | |
| 15 | The behavior is also controlled by the kernel command line |
| 16 | parameter printk.time=1. See Documentation/kernel-parameters.txt |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | |
Alex Elder | 42a9dc0 | 2014-08-06 16:09:01 -0700 | [diff] [blame] | 18 | config MESSAGE_LOGLEVEL_DEFAULT |
Mandeep Singh Baines | 5af5bcb | 2011-03-22 16:34:23 -0700 | [diff] [blame] | 19 | int "Default message log level (1-7)" |
| 20 | range 1 7 |
| 21 | default "4" |
| 22 | help |
| 23 | Default log level for printk statements with no specified priority. |
| 24 | |
| 25 | This was hard-coded to KERN_WARNING since at least 2.6.10 but folks |
| 26 | that are auditing their logs closely may want to set it to a lower |
| 27 | priority. |
| 28 | |
Dave Hansen | 604ff0d | 2013-07-01 13:04:49 -0700 | [diff] [blame] | 29 | config BOOT_PRINTK_DELAY |
| 30 | bool "Delay each boot printk message by N milliseconds" |
| 31 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
| 32 | help |
| 33 | This build option allows you to read kernel boot messages |
| 34 | by inserting a short delay after each one. The delay is |
| 35 | specified in milliseconds on the kernel command line, |
| 36 | using "boot_delay=N". |
| 37 | |
| 38 | It is likely that you would also need to use "lpj=M" to preset |
| 39 | the "loops per jiffie" value. |
| 40 | See a previous boot log for the "lpj" value to use for your |
| 41 | system, and then set "lpj=M" before setting "boot_delay=N". |
| 42 | NOTE: Using this option may adversely affect SMP systems. |
| 43 | I.e., processors other than the first one may not boot up. |
| 44 | BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect |
| 45 | what it believes to be lockup conditions. |
| 46 | |
| 47 | config DYNAMIC_DEBUG |
| 48 | bool "Enable dynamic printk() support" |
| 49 | default n |
| 50 | depends on PRINTK |
| 51 | depends on DEBUG_FS |
| 52 | help |
| 53 | |
| 54 | Compiles debug level messages into the kernel, which would not |
| 55 | otherwise be available at runtime. These messages can then be |
| 56 | enabled/disabled based on various levels of scope - per source file, |
| 57 | function, module, format string, and line number. This mechanism |
| 58 | implicitly compiles in all pr_debug() and dev_dbg() calls, which |
| 59 | enlarges the kernel text size by about 2%. |
| 60 | |
| 61 | If a source file is compiled with DEBUG flag set, any |
| 62 | pr_debug() calls in it are enabled by default, but can be |
| 63 | disabled at runtime as below. Note that DEBUG flag is |
| 64 | turned on by many CONFIG_*DEBUG* options. |
| 65 | |
| 66 | Usage: |
| 67 | |
| 68 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
| 69 | which is contained in the 'debugfs' filesystem. Thus, the debugfs |
| 70 | filesystem must first be mounted before making use of this feature. |
| 71 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
| 72 | file contains a list of the debug statements that can be enabled. The |
| 73 | format for each line of the file is: |
| 74 | |
| 75 | filename:lineno [module]function flags format |
| 76 | |
| 77 | filename : source file of the debug statement |
| 78 | lineno : line number of the debug statement |
| 79 | module : module that contains the debug statement |
| 80 | function : function that contains the debug statement |
| 81 | flags : '=p' means the line is turned 'on' for printing |
| 82 | format : the format used for the debug statement |
| 83 | |
| 84 | From a live system: |
| 85 | |
| 86 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
| 87 | # filename:lineno [module]function flags format |
| 88 | fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012" |
| 89 | fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012" |
| 90 | fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012" |
| 91 | |
| 92 | Example usage: |
| 93 | |
| 94 | // enable the message at line 1603 of file svcsock.c |
| 95 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
| 96 | <debugfs>/dynamic_debug/control |
| 97 | |
| 98 | // enable all the messages in file svcsock.c |
| 99 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
| 100 | <debugfs>/dynamic_debug/control |
| 101 | |
| 102 | // enable all the messages in the NFS server module |
| 103 | nullarbor:~ # echo -n 'module nfsd +p' > |
| 104 | <debugfs>/dynamic_debug/control |
| 105 | |
| 106 | // enable all 12 messages in the function svc_process() |
| 107 | nullarbor:~ # echo -n 'func svc_process +p' > |
| 108 | <debugfs>/dynamic_debug/control |
| 109 | |
| 110 | // disable all 12 messages in the function svc_process() |
| 111 | nullarbor:~ # echo -n 'func svc_process -p' > |
| 112 | <debugfs>/dynamic_debug/control |
| 113 | |
| 114 | See Documentation/dynamic-debug-howto.txt for additional information. |
| 115 | |
| 116 | endmenu # "printk and dmesg options" |
| 117 | |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 118 | menu "Compile-time checks and compiler options" |
| 119 | |
| 120 | config DEBUG_INFO |
| 121 | bool "Compile the kernel with debug info" |
Linus Torvalds | 12b1383 | 2014-02-04 12:20:01 -0800 | [diff] [blame] | 122 | depends on DEBUG_KERNEL && !COMPILE_TEST |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 123 | help |
| 124 | If you say Y here the resulting kernel image will include |
| 125 | debugging info resulting in a larger kernel image. |
| 126 | This adds debug symbols to the kernel and modules (gcc -g), and |
| 127 | is needed if you intend to use kernel crashdump or binary object |
| 128 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
| 129 | Say Y here only if you plan to debug the kernel. |
| 130 | |
| 131 | If unsure, say N. |
| 132 | |
| 133 | config DEBUG_INFO_REDUCED |
| 134 | bool "Reduce debugging information" |
| 135 | depends on DEBUG_INFO |
| 136 | help |
| 137 | If you say Y here gcc is instructed to generate less debugging |
| 138 | information for structure types. This means that tools that |
| 139 | need full debugging information (like kgdb or systemtap) won't |
| 140 | be happy. But if you merely need debugging information to |
| 141 | resolve line numbers there is no loss. Advantage is that |
| 142 | build directory object sizes shrink dramatically over a full |
| 143 | DEBUG_INFO build and compile times are reduced too. |
| 144 | Only works with newer gcc versions. |
| 145 | |
Andi Kleen | 866ced9 | 2014-07-30 20:50:18 +0200 | [diff] [blame] | 146 | config DEBUG_INFO_SPLIT |
| 147 | bool "Produce split debuginfo in .dwo files" |
| 148 | depends on DEBUG_INFO |
| 149 | help |
| 150 | Generate debug info into separate .dwo files. This significantly |
| 151 | reduces the build directory size for builds with DEBUG_INFO, |
| 152 | because it stores the information only once on disk in .dwo |
| 153 | files instead of multiple times in object files and executables. |
| 154 | In addition the debug information is also compressed. |
| 155 | |
| 156 | Requires recent gcc (4.7+) and recent gdb/binutils. |
| 157 | Any tool that packages or reads debug information would need |
| 158 | to know about the .dwo files and include them. |
| 159 | Incompatible with older versions of ccache. |
| 160 | |
Andi Kleen | bfaf2dd | 2014-07-30 20:50:19 +0200 | [diff] [blame] | 161 | config DEBUG_INFO_DWARF4 |
| 162 | bool "Generate dwarf4 debuginfo" |
| 163 | depends on DEBUG_INFO |
| 164 | help |
| 165 | Generate dwarf4 debug info. This requires recent versions |
| 166 | of gcc and gdb. It makes the debug information larger. |
| 167 | But it significantly improves the success of resolving |
| 168 | variables in gdb on optimized code. |
| 169 | |
Jan Kiszka | 3ee7b3f | 2015-02-17 13:46:36 -0800 | [diff] [blame] | 170 | config GDB_SCRIPTS |
| 171 | bool "Provide GDB scripts for kernel debugging" |
| 172 | depends on DEBUG_INFO |
| 173 | help |
| 174 | This creates the required links to GDB helper scripts in the |
| 175 | build directory. If you load vmlinux into gdb, the helper |
| 176 | scripts will be automatically imported by gdb as well, and |
| 177 | additional functions are available to analyze a Linux kernel |
| 178 | instance. See Documentation/gdb-kernel-debugging.txt for further |
| 179 | details. |
| 180 | |
Jeff Garzik | de48844 | 2007-10-25 04:06:13 -0400 | [diff] [blame] | 181 | config ENABLE_WARN_DEPRECATED |
| 182 | bool "Enable __deprecated logic" |
| 183 | default y |
| 184 | help |
| 185 | Enable the __deprecated logic in the kernel build. |
| 186 | Disable this to suppress the "warning: 'foo' is deprecated |
| 187 | (declared at kernel/power/somefile.c:1234)" messages. |
| 188 | |
Andrew Morton | cebc04b | 2006-08-14 22:43:18 -0700 | [diff] [blame] | 189 | config ENABLE_MUST_CHECK |
| 190 | bool "Enable __must_check logic" |
| 191 | default y |
| 192 | help |
| 193 | Enable the __must_check logic in the kernel build. Disable this to |
| 194 | suppress the "warning: ignoring return value of 'foo', declared with |
| 195 | attribute warn_unused_result" messages. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | |
Andi Kleen | 35bb5b1 | 2008-02-22 15:15:03 +0100 | [diff] [blame] | 197 | config FRAME_WARN |
| 198 | int "Warn for stack frames larger than (needs gcc 4.4)" |
| 199 | range 0 8192 |
Andrey Ryabinin | 3f181b4 | 2015-10-22 13:32:24 -0700 | [diff] [blame] | 200 | default 0 if KASAN |
Andi Kleen | 35bb5b1 | 2008-02-22 15:15:03 +0100 | [diff] [blame] | 201 | default 1024 if !64BIT |
| 202 | default 2048 if 64BIT |
| 203 | help |
| 204 | Tell gcc to warn at build time for stack frames larger than this. |
| 205 | Setting this too low will cause a lot of warnings. |
| 206 | Setting it to 0 disables the warning. |
| 207 | Requires gcc 4.4 |
| 208 | |
Randy Dunlap | 99657c7 | 2009-09-18 12:49:22 -0700 | [diff] [blame] | 209 | config STRIP_ASM_SYMS |
| 210 | bool "Strip assembler-generated symbols during link" |
| 211 | default n |
| 212 | help |
| 213 | Strip internal assembler-generated symbols during a link (symbols |
| 214 | that look like '.Lxxx') so they don't pollute the output of |
| 215 | get_wchan() and suchlike. |
| 216 | |
Andi Kleen | 1873e87 | 2012-03-28 11:51:18 -0700 | [diff] [blame] | 217 | config READABLE_ASM |
| 218 | bool "Generate readable assembler code" |
| 219 | depends on DEBUG_KERNEL |
| 220 | help |
| 221 | Disable some compiler optimizations that tend to generate human unreadable |
| 222 | assembler output. This may make the kernel slightly slower, but it helps |
| 223 | to keep kernel developers who have to stare a lot at assembler listings |
| 224 | sane. |
| 225 | |
Arjan van de Ven | f71d20e | 2006-06-28 04:26:45 -0700 | [diff] [blame] | 226 | config UNUSED_SYMBOLS |
| 227 | bool "Enable unused/obsolete exported symbols" |
| 228 | default y if X86 |
| 229 | help |
| 230 | Unused but exported symbols make the kernel needlessly bigger. For |
| 231 | that reason most of these unused exports will soon be removed. This |
| 232 | option is provided temporarily to provide a transition period in case |
| 233 | some external kernel module needs one of these symbols anyway. If you |
| 234 | encounter such a case in your module, consider if you are actually |
| 235 | using the right API. (rationale: since nobody in the kernel is using |
| 236 | this in a module, there is a pretty good chance it's actually the |
| 237 | wrong interface to use). If you really need the symbol, please send a |
| 238 | mail to the linux kernel mailing list mentioning the symbol and why |
| 239 | you really need it, and what the merge plan to the mainline kernel for |
| 240 | your module is. |
| 241 | |
Joonsoo Kim | 48c96a3 | 2014-12-12 16:56:01 -0800 | [diff] [blame] | 242 | config PAGE_OWNER |
| 243 | bool "Track page owner" |
| 244 | depends on DEBUG_KERNEL && STACKTRACE_SUPPORT |
| 245 | select DEBUG_FS |
| 246 | select STACKTRACE |
| 247 | select PAGE_EXTENSION |
| 248 | help |
| 249 | This keeps track of what call chain is the owner of a page, may |
| 250 | help to find bare alloc_page(s) leaks. Even if you include this |
| 251 | feature on your build, it is disabled in default. You should pass |
| 252 | "page_owner=on" to boot parameter in order to enable it. Eats |
| 253 | a fair amount of memory if enabled. See tools/vm/page_owner_sort.c |
| 254 | for user-space helper. |
| 255 | |
| 256 | If unsure, say N. |
| 257 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 258 | config DEBUG_FS |
| 259 | bool "Debug Filesystem" |
Nicolai Stange | 9fd4dce | 2016-03-22 14:11:13 +0100 | [diff] [blame] | 260 | select SRCU |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 261 | help |
| 262 | debugfs is a virtual file system that kernel developers use to put |
| 263 | debugging files into. Enable this option to be able to read and |
| 264 | write to these files. |
| 265 | |
Robert P. J. Day | ff54333 | 2008-05-20 00:06:00 +0200 | [diff] [blame] | 266 | For detailed documentation on the debugfs API, see |
| 267 | Documentation/DocBook/filesystems. |
| 268 | |
Don Mullis | bf4735a | 2006-12-10 02:18:37 -0800 | [diff] [blame] | 269 | If unsure, say N. |
| 270 | |
| 271 | config HEADERS_CHECK |
| 272 | bool "Run 'make headers_check' when building vmlinux" |
| 273 | depends on !UML |
| 274 | help |
| 275 | This option will extract the user-visible kernel headers whenever |
| 276 | building the kernel, and will run basic sanity checks on them to |
| 277 | ensure that exported files do not attempt to include files which |
| 278 | were not exported, etc. |
| 279 | |
| 280 | If you're making modifications to header files which are |
| 281 | relevant for userspace, say 'Y', and check the headers |
| 282 | exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in |
| 283 | your build tree), to make sure they're suitable. |
| 284 | |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 285 | config DEBUG_SECTION_MISMATCH |
| 286 | bool "Enable full Section mismatch analysis" |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 287 | help |
| 288 | The section mismatch analysis checks if there are illegal |
| 289 | references from one section to another section. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 290 | During linktime or runtime, some sections are dropped; |
| 291 | any use of code/data previously in these sections would |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 292 | most likely result in an oops. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 293 | In the code, functions and variables are annotated with |
Paul Gortmaker | 0db0628 | 2013-06-19 14:53:51 -0400 | [diff] [blame] | 294 | __init,, etc. (see the full list in include/linux/init.h), |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 295 | which results in the code/data being placed in specific sections. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 296 | The section mismatch analysis is always performed after a full |
| 297 | kernel build, and enabling this option causes the following |
| 298 | additional steps to occur: |
| 299 | - Add the option -fno-inline-functions-called-once to gcc commands. |
| 300 | When inlining a function annotated with __init in a non-init |
| 301 | function, we would lose the section information and thus |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 302 | the analysis would not catch the illegal reference. |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 303 | This option tells gcc to inline less (but it does result in |
| 304 | a larger kernel). |
| 305 | - Run the section mismatch analysis for each module/built-in.o file. |
| 306 | When we run the section mismatch analysis on vmlinux.o, we |
Geert Uytterhoeven | d6fbfa4 | 2008-01-30 11:13:23 +0100 | [diff] [blame] | 307 | lose valueble information about where the mismatch was |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 308 | introduced. |
| 309 | Running the analysis for each module/built-in.o file |
Michael Witten | e809ab0 | 2011-04-17 04:08:48 +0000 | [diff] [blame] | 310 | tells where the mismatch happens much closer to the |
| 311 | source. The drawback is that the same mismatch is |
| 312 | reported at least twice. |
| 313 | - Enable verbose reporting from modpost in order to help resolve |
| 314 | the section mismatches that are reported. |
Sam Ravnborg | 91341d4 | 2008-01-21 21:31:44 +0100 | [diff] [blame] | 315 | |
Nicolas Boichat | 47490ec | 2015-10-06 09:44:42 +1030 | [diff] [blame] | 316 | config SECTION_MISMATCH_WARN_ONLY |
| 317 | bool "Make section mismatch errors non-fatal" |
| 318 | default y |
| 319 | help |
| 320 | If you say N here, the build process will fail if there are any |
| 321 | section mismatch, instead of just throwing warnings. |
| 322 | |
| 323 | If unsure, say Y. |
| 324 | |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 325 | # |
| 326 | # Select this config option from the architecture Kconfig, if it |
| 327 | # is preferred to always offer frame pointers as a config |
| 328 | # option on the architecture (regardless of KERNEL_DEBUG): |
| 329 | # |
| 330 | config ARCH_WANT_FRAME_POINTERS |
| 331 | bool |
| 332 | help |
| 333 | |
| 334 | config FRAME_POINTER |
| 335 | bool "Compile the kernel with frame pointers" |
| 336 | depends on DEBUG_KERNEL && \ |
| 337 | (CRIS || M68K || FRV || UML || \ |
| 338 | AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || \ |
| 339 | ARCH_WANT_FRAME_POINTERS |
| 340 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
| 341 | help |
| 342 | If you say Y here the resulting kernel image will be slightly |
| 343 | larger and slower, but it gives very useful debugging information |
| 344 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
| 345 | |
Josh Poimboeuf | b9ab5eb | 2016-02-28 22:22:42 -0600 | [diff] [blame] | 346 | config STACK_VALIDATION |
| 347 | bool "Compile-time stack metadata validation" |
| 348 | depends on HAVE_STACK_VALIDATION |
| 349 | default n |
| 350 | help |
| 351 | Add compile-time checks to validate stack metadata, including frame |
| 352 | pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure |
| 353 | that runtime stack traces are more reliable. |
| 354 | |
| 355 | For more information, see |
| 356 | tools/objtool/Documentation/stack-validation.txt. |
| 357 | |
Dave Hansen | 6dfc066 | 2013-07-01 13:04:46 -0700 | [diff] [blame] | 358 | config DEBUG_FORCE_WEAK_PER_CPU |
| 359 | bool "Force weak per-cpu definitions" |
| 360 | depends on DEBUG_KERNEL |
| 361 | help |
| 362 | s390 and alpha require percpu variables in modules to be |
| 363 | defined weak to work around addressing range issue which |
| 364 | puts the following two restrictions on percpu variable |
| 365 | definitions. |
| 366 | |
| 367 | 1. percpu symbols must be unique whether static or not |
| 368 | 2. percpu variables can't be defined inside a function |
| 369 | |
| 370 | To ensure that generic code follows the above rules, this |
| 371 | option forces all percpu variables to be defined as weak. |
| 372 | |
| 373 | endmenu # "Compiler options" |
| 374 | |
| 375 | config MAGIC_SYSRQ |
| 376 | bool "Magic SysRq key" |
| 377 | depends on !UML |
| 378 | help |
| 379 | If you say Y here, you will have some control over the system even |
| 380 | if the system crashes for example during kernel debugging (e.g., you |
| 381 | will be able to flush the buffer cache to disk, reboot the system |
| 382 | immediately or dump some status information). This is accomplished |
| 383 | by pressing various keys while holding SysRq (Alt+PrintScreen). It |
| 384 | also works on a serial console (on PC hardware at least), if you |
| 385 | send a BREAK and then within 5 seconds a command keypress. The |
| 386 | keys are documented in <file:Documentation/sysrq.txt>. Don't say Y |
| 387 | unless you really know what this hack does. |
| 388 | |
Ben Hutchings | 8eaede4 | 2013-10-07 01:05:46 +0100 | [diff] [blame] | 389 | config MAGIC_SYSRQ_DEFAULT_ENABLE |
| 390 | hex "Enable magic SysRq key functions by default" |
| 391 | depends on MAGIC_SYSRQ |
| 392 | default 0x1 |
| 393 | help |
| 394 | Specifies which SysRq key functions are enabled by default. |
| 395 | This may be set to 1 or 0 to enable or disable them all, or |
| 396 | to a bitmask as described in Documentation/sysrq.txt. |
| 397 | |
Adrian Bunk | f346f4b | 2006-01-09 20:54:51 -0800 | [diff] [blame] | 398 | config DEBUG_KERNEL |
| 399 | bool "Kernel debugging" |
| 400 | help |
| 401 | Say Y here if you are developing drivers or trying to debug and |
| 402 | identify kernel problems. |
| 403 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 404 | menu "Memory Debugging" |
David Woodhouse | a304e1b | 2007-02-12 00:52:00 -0800 | [diff] [blame] | 405 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 406 | source mm/Kconfig.debug |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 407 | |
Thomas Gleixner | 3ac7fe5 | 2008-04-30 00:55:01 -0700 | [diff] [blame] | 408 | config DEBUG_OBJECTS |
| 409 | bool "Debug object operations" |
| 410 | depends on DEBUG_KERNEL |
| 411 | help |
| 412 | If you say Y here, additional code will be inserted into the |
| 413 | kernel to track the life time of various objects and validate |
| 414 | the operations on those objects. |
| 415 | |
| 416 | config DEBUG_OBJECTS_SELFTEST |
| 417 | bool "Debug objects selftest" |
| 418 | depends on DEBUG_OBJECTS |
| 419 | help |
| 420 | This enables the selftest of the object debug code. |
| 421 | |
| 422 | config DEBUG_OBJECTS_FREE |
| 423 | bool "Debug objects in freed memory" |
| 424 | depends on DEBUG_OBJECTS |
| 425 | help |
| 426 | This enables checks whether a k/v free operation frees an area |
| 427 | which contains an object which has not been deactivated |
| 428 | properly. This can make kmalloc/kfree-intensive workloads |
| 429 | much slower. |
| 430 | |
Thomas Gleixner | c6f3a97 | 2008-04-30 00:55:03 -0700 | [diff] [blame] | 431 | config DEBUG_OBJECTS_TIMERS |
| 432 | bool "Debug timer objects" |
| 433 | depends on DEBUG_OBJECTS |
| 434 | help |
| 435 | If you say Y here, additional code will be inserted into the |
| 436 | timer routines to track the life time of timer objects and |
| 437 | validate the timer operations. |
| 438 | |
Thomas Gleixner | dc186ad | 2009-11-16 01:09:48 +0900 | [diff] [blame] | 439 | config DEBUG_OBJECTS_WORK |
| 440 | bool "Debug work objects" |
| 441 | depends on DEBUG_OBJECTS |
| 442 | help |
| 443 | If you say Y here, additional code will be inserted into the |
| 444 | work queue routines to track the life time of work objects and |
| 445 | validate the work operations. |
| 446 | |
Mathieu Desnoyers | 551d55a | 2010-04-17 08:48:42 -0400 | [diff] [blame] | 447 | config DEBUG_OBJECTS_RCU_HEAD |
| 448 | bool "Debug RCU callbacks objects" |
Mathieu Desnoyers | fc2ecf7 | 2011-02-23 09:42:14 -0800 | [diff] [blame] | 449 | depends on DEBUG_OBJECTS |
Mathieu Desnoyers | 551d55a | 2010-04-17 08:48:42 -0400 | [diff] [blame] | 450 | help |
| 451 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). |
| 452 | |
Tejun Heo | e2852ae | 2010-10-26 14:23:05 -0700 | [diff] [blame] | 453 | config DEBUG_OBJECTS_PERCPU_COUNTER |
| 454 | bool "Debug percpu counter objects" |
| 455 | depends on DEBUG_OBJECTS |
| 456 | help |
| 457 | If you say Y here, additional code will be inserted into the |
| 458 | percpu counter routines to track the life time of percpu counter |
| 459 | objects and validate the percpu counter operations. |
| 460 | |
Ingo Molnar | 3ae7020 | 2008-11-26 10:02:00 +0100 | [diff] [blame] | 461 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
| 462 | int "debug_objects bootup default value (0-1)" |
| 463 | range 0 1 |
| 464 | default "1" |
| 465 | depends on DEBUG_OBJECTS |
| 466 | help |
| 467 | Debug objects boot parameter default value |
| 468 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | config DEBUG_SLAB |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 470 | bool "Debug slab memory allocations" |
Vegard Nossum | 7d46d9e | 2008-04-04 00:51:41 +0200 | [diff] [blame] | 471 | depends on DEBUG_KERNEL && SLAB && !KMEMCHECK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | help |
| 473 | Say Y here to have the kernel do limited verification on memory |
| 474 | allocation as well as poisoning memory on free to catch use of freed |
| 475 | memory. This can make kmalloc/kfree-intensive workloads much slower. |
| 476 | |
Al Viro | 871751e | 2006-03-25 03:06:39 -0800 | [diff] [blame] | 477 | config DEBUG_SLAB_LEAK |
| 478 | bool "Memory leak debugging" |
| 479 | depends on DEBUG_SLAB |
| 480 | |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 481 | config SLUB_DEBUG_ON |
| 482 | bool "SLUB debugging on by default" |
Vegard Nossum | 7d46d9e | 2008-04-04 00:51:41 +0200 | [diff] [blame] | 483 | depends on SLUB && SLUB_DEBUG && !KMEMCHECK |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 484 | default n |
| 485 | help |
| 486 | Boot with debugging on by default. SLUB boots by default with |
| 487 | the runtime debug capabilities switched off. Enabling this is |
| 488 | equivalent to specifying the "slub_debug" parameter on boot. |
| 489 | There is no support for more fine grained debug control like |
| 490 | possible with slub_debug=xxx. SLUB debugging may be switched |
| 491 | off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying |
| 492 | "slub_debug=-". |
| 493 | |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 494 | config SLUB_STATS |
| 495 | default n |
| 496 | bool "Enable SLUB performance statistics" |
Christoph Lameter | ab4d5ed | 2010-10-05 13:57:26 -0500 | [diff] [blame] | 497 | depends on SLUB && SYSFS |
Christoph Lameter | 8ff12cf | 2008-02-07 17:47:41 -0800 | [diff] [blame] | 498 | help |
| 499 | SLUB statistics are useful to debug SLUBs allocation behavior in |
| 500 | order find ways to optimize the allocator. This should never be |
| 501 | enabled for production use since keeping statistics slows down |
| 502 | the allocator by a few percentage points. The slabinfo command |
| 503 | supports the determination of the most active slabs to figure |
| 504 | out which slabs are relevant to a particular load. |
| 505 | Try running: slabinfo -DA |
| 506 | |
Catalin Marinas | b69ec42 | 2012-10-08 16:28:11 -0700 | [diff] [blame] | 507 | config HAVE_DEBUG_KMEMLEAK |
| 508 | bool |
| 509 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 510 | config DEBUG_KMEMLEAK |
| 511 | bool "Kernel memory leak detector" |
Kees Cook | 525c1f9 | 2013-01-16 18:54:16 -0800 | [diff] [blame] | 512 | depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK |
Catalin Marinas | 79e0d9b | 2011-04-27 17:06:19 +0100 | [diff] [blame] | 513 | select DEBUG_FS |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 514 | select STACKTRACE if STACKTRACE_SUPPORT |
| 515 | select KALLSYMS |
Randy Dunlap | b60e26a | 2009-11-06 15:33:45 -0800 | [diff] [blame] | 516 | select CRC32 |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 517 | help |
| 518 | Say Y here if you want to enable the memory leak |
| 519 | detector. The memory allocation/freeing is traced in a way |
| 520 | similar to the Boehm's conservative garbage collector, the |
| 521 | difference being that the orphan objects are not freed but |
| 522 | only shown in /sys/kernel/debug/kmemleak. Enabling this |
| 523 | feature will introduce an overhead to memory |
| 524 | allocations. See Documentation/kmemleak.txt for more |
| 525 | details. |
| 526 | |
Catalin Marinas | bf96d1e | 2009-06-23 14:40:27 +0100 | [diff] [blame] | 527 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
| 528 | of finding leaks due to the slab objects poisoning. |
| 529 | |
Catalin Marinas | 3bba00d | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 530 | In order to access the kmemleak file, debugfs needs to be |
| 531 | mounted (usually at /sys/kernel/debug). |
| 532 | |
Catalin Marinas | a9d9058 | 2009-06-25 10:16:11 +0100 | [diff] [blame] | 533 | config DEBUG_KMEMLEAK_EARLY_LOG_SIZE |
| 534 | int "Maximum kmemleak early log entries" |
| 535 | depends on DEBUG_KMEMLEAK |
Heiko Carstens | dfcc3e6 | 2009-10-06 10:33:57 +0200 | [diff] [blame] | 536 | range 200 40000 |
Catalin Marinas | a9d9058 | 2009-06-25 10:16:11 +0100 | [diff] [blame] | 537 | default 400 |
| 538 | help |
| 539 | Kmemleak must track all the memory allocations to avoid |
| 540 | reporting false positives. Since memory may be allocated or |
| 541 | freed before kmemleak is initialised, an early log buffer is |
| 542 | used to store these actions. If kmemleak reports "early log |
| 543 | buffer exceeded", please increase this value. |
| 544 | |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 545 | config DEBUG_KMEMLEAK_TEST |
| 546 | tristate "Simple test for the kernel memory leak detector" |
Daniel Baluta | 9718269 | 2011-04-04 15:06:44 -0700 | [diff] [blame] | 547 | depends on DEBUG_KMEMLEAK && m |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 548 | help |
Daniel Baluta | 9718269 | 2011-04-04 15:06:44 -0700 | [diff] [blame] | 549 | This option enables a module that explicitly leaks memory. |
Catalin Marinas | 0822ee4 | 2009-06-11 13:24:14 +0100 | [diff] [blame] | 550 | |
| 551 | If unsure, say N. |
| 552 | |
Jason Baron | ab0155a | 2010-07-19 11:54:17 +0100 | [diff] [blame] | 553 | config DEBUG_KMEMLEAK_DEFAULT_OFF |
| 554 | bool "Default kmemleak to off" |
| 555 | depends on DEBUG_KMEMLEAK |
| 556 | help |
| 557 | Say Y here to disable kmemleak by default. It can then be enabled |
| 558 | on the command line via kmemleak=on. |
| 559 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 560 | config DEBUG_STACK_USAGE |
| 561 | bool "Stack utilization instrumentation" |
Helge Deller | 6c31da3 | 2016-03-19 17:54:10 +0100 | [diff] [blame] | 562 | depends on DEBUG_KERNEL && !IA64 |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 563 | help |
| 564 | Enables the display of the minimum amount of free stack which each |
| 565 | task has ever had available in the sysrq-T and sysrq-P debug output. |
| 566 | |
| 567 | This option will slow down process creation somewhat. |
| 568 | |
| 569 | config DEBUG_VM |
| 570 | bool "Debug VM" |
| 571 | depends on DEBUG_KERNEL |
| 572 | help |
| 573 | Enable this to turn on extended checks in the virtual-memory system |
| 574 | that may impact performance. |
| 575 | |
| 576 | If unsure, say N. |
| 577 | |
Davidlohr Bueso | 4f11514 | 2014-06-04 16:06:46 -0700 | [diff] [blame] | 578 | config DEBUG_VM_VMACACHE |
| 579 | bool "Debug VMA caching" |
| 580 | depends on DEBUG_VM |
| 581 | help |
| 582 | Enable this to turn on VMA caching debug information. Doing so |
| 583 | can cause significant overhead, so only enable it in non-production |
| 584 | environments. |
| 585 | |
| 586 | If unsure, say N. |
| 587 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 588 | config DEBUG_VM_RB |
| 589 | bool "Debug VM red-black trees" |
| 590 | depends on DEBUG_VM |
| 591 | help |
Davidlohr Bueso | a663dad | 2014-04-18 15:07:22 -0700 | [diff] [blame] | 592 | Enable VM red-black tree debugging information and extra validations. |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 593 | |
| 594 | If unsure, say N. |
| 595 | |
Kirill A. Shutemov | 95ad975 | 2016-01-15 16:51:21 -0800 | [diff] [blame] | 596 | config DEBUG_VM_PGFLAGS |
| 597 | bool "Debug page-flags operations" |
| 598 | depends on DEBUG_VM |
| 599 | help |
| 600 | Enables extra validation on page flags operations. |
| 601 | |
| 602 | If unsure, say N. |
| 603 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 604 | config DEBUG_VIRTUAL |
| 605 | bool "Debug VM translations" |
| 606 | depends on DEBUG_KERNEL && X86 |
| 607 | help |
| 608 | Enable some costly sanity checks in virtual to page code. This can |
| 609 | catch mistakes with virt_to_page() and friends. |
| 610 | |
| 611 | If unsure, say N. |
| 612 | |
| 613 | config DEBUG_NOMMU_REGIONS |
| 614 | bool "Debug the global anon/private NOMMU mapping region tree" |
| 615 | depends on DEBUG_KERNEL && !MMU |
| 616 | help |
| 617 | This option causes the global tree of anonymous and private mapping |
| 618 | regions to be regularly checked for invalid topology. |
| 619 | |
| 620 | config DEBUG_MEMORY_INIT |
| 621 | bool "Debug memory initialisation" if EXPERT |
| 622 | default !EXPERT |
| 623 | help |
| 624 | Enable this for additional checks during memory initialisation. |
| 625 | The sanity checks verify aspects of the VM such as the memory model |
| 626 | and other information provided by the architecture. Verbose |
| 627 | information will be printed at KERN_DEBUG loglevel depending |
| 628 | on the mminit_loglevel= command-line option. |
| 629 | |
| 630 | If unsure, say Y |
| 631 | |
| 632 | config MEMORY_NOTIFIER_ERROR_INJECT |
| 633 | tristate "Memory hotplug notifier error injection module" |
| 634 | depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION |
| 635 | help |
| 636 | This option provides the ability to inject artificial errors to |
| 637 | memory hotplug notifier chain callbacks. It is controlled through |
| 638 | debugfs interface under /sys/kernel/debug/notifier-error-inject/memory |
| 639 | |
| 640 | If the notifier call chain should be failed with some events |
| 641 | notified, write the error code to "actions/<notifier event>/error". |
| 642 | |
| 643 | Example: Inject memory hotplug offline error (-12 == -ENOMEM) |
| 644 | |
| 645 | # cd /sys/kernel/debug/notifier-error-inject/memory |
| 646 | # echo -12 > actions/MEM_GOING_OFFLINE/error |
| 647 | # echo offline > /sys/devices/system/memory/memoryXXX/state |
| 648 | bash: echo: write error: Cannot allocate memory |
| 649 | |
| 650 | To compile this code as a module, choose M here: the module will |
| 651 | be called memory-notifier-error-inject. |
| 652 | |
| 653 | If unsure, say N. |
| 654 | |
| 655 | config DEBUG_PER_CPU_MAPS |
| 656 | bool "Debug access to per_cpu maps" |
| 657 | depends on DEBUG_KERNEL |
| 658 | depends on SMP |
| 659 | help |
| 660 | Say Y to verify that the per_cpu map being accessed has |
| 661 | been set up. This adds a fair amount of code to kernel memory |
| 662 | and decreases performance. |
| 663 | |
| 664 | Say N if unsure. |
| 665 | |
| 666 | config DEBUG_HIGHMEM |
| 667 | bool "Highmem debugging" |
| 668 | depends on DEBUG_KERNEL && HIGHMEM |
| 669 | help |
Geert Uytterhoeven | b1357c9 | 2014-04-14 18:55:50 +0200 | [diff] [blame] | 670 | This option enables additional error checking for high memory |
| 671 | systems. Disable for production systems. |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 672 | |
| 673 | config HAVE_DEBUG_STACKOVERFLOW |
| 674 | bool |
| 675 | |
| 676 | config DEBUG_STACKOVERFLOW |
| 677 | bool "Check for stack overflows" |
| 678 | depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW |
| 679 | ---help--- |
| 680 | 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] | 681 | and exception stacks (if your architecture uses them). This |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 682 | option will show detailed messages if free stack space drops |
| 683 | below a certain limit. |
| 684 | |
| 685 | These kinds of bugs usually occur when call-chains in the |
| 686 | kernel get too deep, especially when interrupts are |
| 687 | involved. |
| 688 | |
| 689 | Use this in cases where you see apparently random memory |
| 690 | corruption, especially if it appears in 'struct thread_info' |
| 691 | |
| 692 | If in doubt, say "N". |
| 693 | |
| 694 | source "lib/Kconfig.kmemcheck" |
| 695 | |
Andrey Ryabinin | 0b24bec | 2015-02-13 14:39:17 -0800 | [diff] [blame] | 696 | source "lib/Kconfig.kasan" |
| 697 | |
Dave Hansen | 0610c8a | 2013-07-01 13:04:43 -0700 | [diff] [blame] | 698 | endmenu # "Memory Debugging" |
| 699 | |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 700 | config ARCH_HAS_KCOV |
| 701 | bool |
| 702 | help |
| 703 | KCOV does not have any arch-specific code, but currently it is enabled |
| 704 | only for x86_64. KCOV requires testing on other archs, and most likely |
| 705 | disabling of instrumentation for some early boot code. |
| 706 | |
| 707 | config KCOV |
| 708 | bool "Code coverage for fuzzing" |
| 709 | depends on ARCH_HAS_KCOV |
| 710 | select DEBUG_FS |
| 711 | help |
| 712 | KCOV exposes kernel code coverage information in a form suitable |
| 713 | for coverage-guided fuzzing (randomized testing). |
| 714 | |
| 715 | If RANDOMIZE_BASE is enabled, PC values will not be stable across |
| 716 | different machines and across reboots. If you need stable PC values, |
| 717 | disable RANDOMIZE_BASE. |
| 718 | |
| 719 | For more details, see Documentation/kcov.txt. |
| 720 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | config DEBUG_SHIRQ |
| 722 | bool "Debug shared IRQ handlers" |
Martin Schwidefsky | 0244ad0 | 2013-08-30 09:39:53 +0200 | [diff] [blame] | 723 | depends on DEBUG_KERNEL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | help |
| 725 | Enable this to generate a spurious interrupt as soon as a shared |
| 726 | interrupt handler is registered, and just before one is deregistered. |
| 727 | Drivers ought to be able to handle interrupts coming in at those |
| 728 | points; some don't and need to be caught. |
| 729 | |
Dave Hansen | 92aef8fb | 2013-07-01 13:04:50 -0700 | [diff] [blame] | 730 | menu "Debug Lockups and Hangs" |
| 731 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | config LOCKUP_DETECTOR |
| 733 | bool "Detect Hard and Soft Lockups" |
| 734 | depends on DEBUG_KERNEL && !S390 |
| 735 | help |
| 736 | Say Y here to enable the kernel to act as a watchdog to detect |
| 737 | hard and soft lockups. |
| 738 | |
| 739 | Softlockups are bugs that cause the kernel to loop in kernel |
| 740 | mode for more than 20 seconds, without giving other tasks a |
| 741 | chance to run. The current stack trace is displayed upon |
| 742 | detection and the system will stay locked up. |
| 743 | |
| 744 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
| 745 | for more than 10 seconds, without letting other interrupts have a |
| 746 | chance to run. The current stack trace is displayed upon detection |
| 747 | and the system will stay locked up. |
| 748 | |
| 749 | The overhead should be minimal. A periodic hrtimer runs to |
| 750 | generate interrupts and kick the watchdog task every 4 seconds. |
| 751 | An NMI is generated every 10 seconds or so to check for hardlockups. |
| 752 | |
| 753 | The frequency of hrtimer and NMI events and the soft and hard lockup |
| 754 | thresholds can be controlled through the sysctl watchdog_thresh. |
| 755 | |
| 756 | config HARDLOCKUP_DETECTOR |
| 757 | def_bool y |
| 758 | depends on LOCKUP_DETECTOR && !HAVE_NMI_WATCHDOG |
| 759 | depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
| 760 | |
| 761 | config BOOTPARAM_HARDLOCKUP_PANIC |
| 762 | bool "Panic (Reboot) On Hard Lockups" |
| 763 | depends on HARDLOCKUP_DETECTOR |
| 764 | help |
| 765 | Say Y here to enable the kernel to panic on "hard lockups", |
| 766 | which are bugs that cause the kernel to loop in kernel |
| 767 | mode with interrupts disabled for more than 10 seconds (configurable |
| 768 | using the watchdog_thresh sysctl). |
| 769 | |
| 770 | Say N if unsure. |
| 771 | |
| 772 | config BOOTPARAM_HARDLOCKUP_PANIC_VALUE |
| 773 | int |
| 774 | depends on HARDLOCKUP_DETECTOR |
| 775 | range 0 1 |
| 776 | default 0 if !BOOTPARAM_HARDLOCKUP_PANIC |
| 777 | default 1 if BOOTPARAM_HARDLOCKUP_PANIC |
| 778 | |
| 779 | config BOOTPARAM_SOFTLOCKUP_PANIC |
| 780 | bool "Panic (Reboot) On Soft Lockups" |
| 781 | depends on LOCKUP_DETECTOR |
| 782 | help |
| 783 | Say Y here to enable the kernel to panic on "soft lockups", |
| 784 | which are bugs that cause the kernel to loop in kernel |
| 785 | mode for more than 20 seconds (configurable using the watchdog_thresh |
| 786 | sysctl), without giving other tasks a chance to run. |
| 787 | |
| 788 | The panic can be used in combination with panic_timeout, |
| 789 | to cause the system to reboot automatically after a |
| 790 | lockup has been detected. This feature is useful for |
| 791 | high-availability systems that have uptime guarantees and |
| 792 | where a lockup must be resolved ASAP. |
| 793 | |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 794 | Say N if unsure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | |
| 796 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE |
| 797 | int |
| 798 | depends on LOCKUP_DETECTOR |
| 799 | range 0 1 |
| 800 | default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC |
| 801 | default 1 if BOOTPARAM_SOFTLOCKUP_PANIC |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 802 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | config DETECT_HUNG_TASK |
| 804 | bool "Detect Hung Tasks" |
| 805 | depends on DEBUG_KERNEL |
| 806 | default LOCKUP_DETECTOR |
| 807 | help |
| 808 | Say Y here to enable the kernel to detect "hung tasks", |
| 809 | which are bugs that cause the task to be stuck in |
| 810 | uninterruptible "D" state indefinitiley. |
| 811 | |
| 812 | When a hung task is detected, the kernel will print the |
| 813 | current stack trace (which you should report), but the |
| 814 | task will stay in uninterruptible state. If lockdep is |
| 815 | enabled then all held locks will also be reported. This |
| 816 | feature has negligible overhead. |
| 817 | |
| 818 | config DEFAULT_HUNG_TASK_TIMEOUT |
| 819 | int "Default timeout for hung task detection (in seconds)" |
| 820 | depends on DETECT_HUNG_TASK |
| 821 | default 120 |
| 822 | help |
| 823 | This option controls the default timeout (in seconds) used |
| 824 | to determine when a task has become non-responsive and should |
| 825 | be considered hung. |
| 826 | |
| 827 | It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
| 828 | sysctl or by writing a value to |
| 829 | /proc/sys/kernel/hung_task_timeout_secs. |
| 830 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 831 | A timeout of 0 disables the check. The default is two minutes. |
| 832 | Keeping the default should be fine in most cases. |
| 833 | |
| 834 | config BOOTPARAM_HUNG_TASK_PANIC |
| 835 | bool "Panic (Reboot) On Hung Tasks" |
| 836 | depends on DETECT_HUNG_TASK |
Tim Chen | cca57c5 | 2006-04-18 22:21:47 -0700 | [diff] [blame] | 837 | help |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 838 | Say Y here to enable the kernel to panic on "hung tasks", |
| 839 | which are bugs that cause the kernel to leave a task stuck |
| 840 | in uninterruptible "D" state. |
| 841 | |
| 842 | The panic can be used in combination with panic_timeout, |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 843 | to cause the system to reboot automatically after a |
| 844 | hung task has been detected. This feature is useful for |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 845 | high-availability systems that have uptime guarantees and |
| 846 | where a hung tasks must be resolved ASAP. |
| 847 | |
| 848 | Say N if unsure. |
| 849 | |
| 850 | config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
| 851 | int |
| 852 | depends on DETECT_HUNG_TASK |
| 853 | range 0 1 |
Hugh Dickins | 048c8bc | 2006-11-01 05:44:54 +1100 | [diff] [blame] | 854 | default 0 if !BOOTPARAM_HUNG_TASK_PANIC |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | default 1 if BOOTPARAM_HUNG_TASK_PANIC |
| 856 | |
Tejun Heo | 82607adc | 2015-12-08 11:28:04 -0500 | [diff] [blame] | 857 | config WQ_WATCHDOG |
| 858 | bool "Detect Workqueue Stalls" |
| 859 | depends on DEBUG_KERNEL |
| 860 | help |
| 861 | Say Y here to enable stall detection on workqueues. If a |
| 862 | worker pool doesn't make forward progress on a pending work |
| 863 | item for over a given amount of time, 30s by default, a |
| 864 | warning message is printed along with dump of workqueue |
| 865 | state. This can be configured through kernel parameter |
| 866 | "workqueue.watchdog_thresh" and its sysfs counterpart. |
| 867 | |
Dave Hansen | 92aef8fb | 2013-07-01 13:04:50 -0700 | [diff] [blame] | 868 | endmenu # "Debug lockups and hangs" |
| 869 | |
| 870 | config PANIC_ON_OOPS |
| 871 | bool "Panic on Oops" |
| 872 | help |
| 873 | Say Y here to enable the kernel to panic when it oopses. This |
| 874 | has the same effect as setting oops=panic on the kernel command |
| 875 | line. |
| 876 | |
| 877 | This feature is useful to ensure that the kernel does not do |
| 878 | anything erroneous after an oops which could result in data |
| 879 | corruption or other issues. |
| 880 | |
| 881 | Say N if unsure. |
| 882 | |
| 883 | config PANIC_ON_OOPS_VALUE |
| 884 | int |
| 885 | range 0 1 |
| 886 | default 0 if !PANIC_ON_OOPS |
| 887 | default 1 if PANIC_ON_OOPS |
| 888 | |
Jason Baron | 5800dc3 | 2013-11-25 23:23:04 +0000 | [diff] [blame] | 889 | config PANIC_TIMEOUT |
| 890 | int "panic timeout" |
| 891 | default 0 |
| 892 | help |
| 893 | Set the timeout value (in seconds) until a reboot occurs when the |
| 894 | the kernel panics. If n = 0, then we wait forever. A timeout |
| 895 | value n > 0 will wait n seconds before rebooting, while a timeout |
| 896 | value n < 0 will reboot immediately. |
| 897 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | config SCHED_DEBUG |
| 899 | bool "Collect scheduler debugging info" |
| 900 | depends on DEBUG_KERNEL && PROC_FS |
| 901 | default y |
| 902 | help |
| 903 | If you say Y here, the /proc/sched_debug file will be provided |
| 904 | that can help debug the scheduler. The runtime overhead of this |
| 905 | option is minimal. |
| 906 | |
Naveen N. Rao | f6db834 | 2015-06-25 23:53:37 +0530 | [diff] [blame] | 907 | config SCHED_INFO |
| 908 | bool |
| 909 | default n |
| 910 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | config SCHEDSTATS |
| 912 | bool "Collect scheduler statistics" |
| 913 | depends on DEBUG_KERNEL && PROC_FS |
Naveen N. Rao | f6db834 | 2015-06-25 23:53:37 +0530 | [diff] [blame] | 914 | select SCHED_INFO |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | help |
| 916 | If you say Y here, additional code will be inserted into the |
| 917 | scheduler and related routines to collect statistics about |
| 918 | scheduler behavior and provide them in /proc/schedstat. These |
| 919 | stats may be useful for both tuning and debugging the scheduler |
| 920 | If you aren't debugging the scheduler or trying to tune a specific |
| 921 | application, you can say N to avoid the very slight overhead |
| 922 | this adds. |
| 923 | |
Aaron Tomlin | 0d9e263 | 2014-09-12 14:16:19 +0100 | [diff] [blame] | 924 | config SCHED_STACK_END_CHECK |
| 925 | bool "Detect stack corruption on calls to schedule()" |
| 926 | depends on DEBUG_KERNEL |
| 927 | default n |
| 928 | help |
| 929 | This option checks for a stack overrun on calls to schedule(). |
| 930 | If the stack end location is found to be over written always panic as |
| 931 | the content of the corrupted region can no longer be trusted. |
| 932 | This is to ensure no erroneous behaviour occurs which could result in |
| 933 | data corruption or a sporadic crash at a later stage once the region |
| 934 | is examined. The runtime overhead introduced is minimal. |
| 935 | |
John Stultz | 3c17ad1 | 2015-03-11 21:16:32 -0700 | [diff] [blame] | 936 | config DEBUG_TIMEKEEPING |
| 937 | bool "Enable extra timekeeping sanity checking" |
| 938 | help |
| 939 | This option will enable additional timekeeping sanity checks |
| 940 | which may be helpful when diagnosing issues where timekeeping |
| 941 | problems are suspected. |
| 942 | |
| 943 | This may include checks in the timekeeping hotpaths, so this |
| 944 | option may have a (very small) performance impact to some |
| 945 | workloads. |
| 946 | |
| 947 | If unsure, say N. |
| 948 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | config TIMER_STATS |
| 950 | bool "Collect kernel timers statistics" |
| 951 | depends on DEBUG_KERNEL && PROC_FS |
| 952 | help |
| 953 | If you say Y here, additional code will be inserted into the |
| 954 | timer routines to collect statistics about kernel timers being |
| 955 | reprogrammed. The statistics can be read from /proc/timer_stats. |
| 956 | The statistics collection is started by writing 1 to /proc/timer_stats, |
| 957 | writing 0 stops it. This feature is useful to collect information |
| 958 | about timer usage patterns in kernel and userspace. This feature |
| 959 | is lightweight if enabled in the kernel config but not activated |
| 960 | (it defaults to deactivated on bootup and will only be activated |
| 961 | if some application like powertop activates it explicitly). |
| 962 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | config DEBUG_PREEMPT |
| 964 | bool "Debug preemptible kernel" |
Kumar Gala | 01deab9 | 2009-10-16 07:21:39 +0000 | [diff] [blame] | 965 | depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | default y |
| 967 | help |
| 968 | If you say Y here then the kernel will use a debug variant of the |
| 969 | commonly used smp_processor_id() function and will print warnings |
| 970 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
| 971 | will detect preemption count underflows. |
| 972 | |
Dave Hansen | 9eade16 | 2013-07-01 13:04:47 -0700 | [diff] [blame] | 973 | menu "Lock Debugging (spinlocks, mutexes, etc...)" |
| 974 | |
Ingo Molnar | e7eebaf | 2006-06-27 02:54:55 -0700 | [diff] [blame] | 975 | config DEBUG_RT_MUTEXES |
| 976 | bool "RT Mutex debugging, deadlock detection" |
| 977 | depends on DEBUG_KERNEL && RT_MUTEXES |
| 978 | help |
| 979 | This allows rt mutex semantics violations and rt mutex related |
| 980 | deadlocks (lockups) to be detected and reported automatically. |
| 981 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | config DEBUG_SPINLOCK |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 983 | bool "Spinlock and rw-lock debugging: basic checks" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | depends on DEBUG_KERNEL |
Raghavendra K T | e335e3e | 2012-03-22 15:25:08 +0530 | [diff] [blame] | 985 | select UNINLINE_SPIN_UNLOCK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 986 | help |
| 987 | Say Y here and build SMP to catch missing spinlock initialization |
| 988 | and certain other kinds of spinlock errors commonly made. This is |
| 989 | best used in conjunction with the NMI watchdog so that spinlock |
| 990 | deadlocks are also debuggable. |
| 991 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 992 | config DEBUG_MUTEXES |
| 993 | bool "Mutex debugging: basic checks" |
| 994 | depends on DEBUG_KERNEL |
| 995 | help |
| 996 | This feature allows mutex semantics violations to be detected and |
| 997 | reported. |
| 998 | |
Daniel Vetter | 2301002 | 2013-06-20 13:31:17 +0200 | [diff] [blame] | 999 | config DEBUG_WW_MUTEX_SLOWPATH |
| 1000 | bool "Wait/wound mutex debugging: Slowpath testing" |
| 1001 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
| 1002 | select DEBUG_LOCK_ALLOC |
| 1003 | select DEBUG_SPINLOCK |
| 1004 | select DEBUG_MUTEXES |
| 1005 | help |
| 1006 | This feature enables slowpath testing for w/w mutex users by |
| 1007 | injecting additional -EDEADLK wound/backoff cases. Together with |
| 1008 | the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this |
| 1009 | will test all possible w/w mutex interface abuse with the |
| 1010 | exception of simply not acquiring all the required locks. |
Rob Clark | 4d69237 | 2014-08-27 11:19:26 -0400 | [diff] [blame] | 1011 | Note that this feature can introduce significant overhead, so |
| 1012 | it really should not be enabled in a production or distro kernel, |
| 1013 | even a debug kernel. If you are a driver writer, enable it. If |
| 1014 | you are a distro, do not. |
Daniel Vetter | 2301002 | 2013-06-20 13:31:17 +0200 | [diff] [blame] | 1015 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1016 | config DEBUG_LOCK_ALLOC |
| 1017 | bool "Lock debugging: detect incorrect freeing of live locks" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 1018 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1019 | select DEBUG_SPINLOCK |
| 1020 | select DEBUG_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1021 | select LOCKDEP |
| 1022 | help |
| 1023 | This feature will check whether any held lock (spinlock, rwlock, |
| 1024 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
| 1025 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
| 1026 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
| 1027 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
| 1028 | held during task exit. |
| 1029 | |
| 1030 | config PROVE_LOCKING |
| 1031 | bool "Lock debugging: prove locking correctness" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 1032 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1033 | select LOCKDEP |
| 1034 | select DEBUG_SPINLOCK |
| 1035 | select DEBUG_MUTEXES |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1036 | select DEBUG_LOCK_ALLOC |
Steven Rostedt | 46b93b7 | 2010-08-31 16:35:20 -0400 | [diff] [blame] | 1037 | select TRACE_IRQFLAGS |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1038 | default n |
| 1039 | help |
| 1040 | This feature enables the kernel to prove that all locking |
| 1041 | that occurs in the kernel runtime is mathematically |
| 1042 | correct: that under no circumstance could an arbitrary (and |
| 1043 | not yet triggered) combination of observed locking |
| 1044 | sequences (on an arbitrary number of CPUs, running an |
| 1045 | arbitrary number of tasks and interrupt contexts) cause a |
| 1046 | deadlock. |
| 1047 | |
| 1048 | In short, this feature enables the kernel to report locking |
| 1049 | related deadlocks before they actually occur. |
| 1050 | |
| 1051 | The proof does not depend on how hard and complex a |
| 1052 | deadlock scenario would be to trigger: how many |
| 1053 | participant CPUs, tasks and irq-contexts would be needed |
| 1054 | for it to trigger. The proof also does not depend on |
| 1055 | timing: if a race and a resulting deadlock is possible |
| 1056 | theoretically (no matter how unlikely the race scenario |
| 1057 | is), it will be proven so and will immediately be |
| 1058 | reported by the kernel (once the event is observed that |
| 1059 | makes the deadlock theoretically possible). |
| 1060 | |
| 1061 | If a deadlock is impossible (i.e. the locking rules, as |
| 1062 | observed by the kernel, are mathematically correct), the |
| 1063 | kernel reports nothing. |
| 1064 | |
| 1065 | NOTE: this feature can also be enabled for rwlocks, mutexes |
| 1066 | and rwsems - in which case all dependencies between these |
| 1067 | different locking variants are observed and mapped too, and |
| 1068 | the proof of observed correctness is also maintained for an |
| 1069 | arbitrary combination of these separate locking variants. |
| 1070 | |
Davidlohr Bueso | 214e0ae | 2014-07-30 13:41:55 -0700 | [diff] [blame] | 1071 | For more details, see Documentation/locking/lockdep-design.txt. |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1072 | |
| 1073 | config LOCKDEP |
| 1074 | bool |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 1075 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1076 | select STACKTRACE |
Chen Gang | df2e1ef | 2014-06-23 13:22:04 -0700 | [diff] [blame] | 1077 | select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE && !ARC && !SCORE |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1078 | select KALLSYMS |
| 1079 | select KALLSYMS_ALL |
| 1080 | |
Peter Zijlstra | f20786f | 2007-07-19 01:48:56 -0700 | [diff] [blame] | 1081 | config LOCK_STAT |
Danny ter Haar | fdfb870 | 2007-09-24 21:24:43 -0700 | [diff] [blame] | 1082 | bool "Lock usage statistics" |
Peter Zijlstra | f20786f | 2007-07-19 01:48:56 -0700 | [diff] [blame] | 1083 | depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
| 1084 | select LOCKDEP |
| 1085 | select DEBUG_SPINLOCK |
| 1086 | select DEBUG_MUTEXES |
| 1087 | select DEBUG_LOCK_ALLOC |
| 1088 | default n |
| 1089 | help |
| 1090 | This feature enables tracking lock contention points |
| 1091 | |
Davidlohr Bueso | 214e0ae | 2014-07-30 13:41:55 -0700 | [diff] [blame] | 1092 | For more details, see Documentation/locking/lockstat.txt |
Peter Zijlstra | a560aa4 | 2007-10-07 00:24:33 -0700 | [diff] [blame] | 1093 | |
Frederic Weisbecker | dd8b1cf | 2010-02-27 17:10:39 +0100 | [diff] [blame] | 1094 | This also enables lock events required by "perf lock", |
| 1095 | subcommand of perf. |
| 1096 | If you want to use "perf lock", you also need to turn on |
| 1097 | CONFIG_EVENT_TRACING. |
Hitoshi Mitake | 84c6f88 | 2010-02-04 16:08:15 +0900 | [diff] [blame] | 1098 | |
| 1099 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. |
Frederic Weisbecker | dd8b1cf | 2010-02-27 17:10:39 +0100 | [diff] [blame] | 1100 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
Hitoshi Mitake | 84c6f88 | 2010-02-04 16:08:15 +0900 | [diff] [blame] | 1101 | |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1102 | config DEBUG_LOCKDEP |
| 1103 | bool "Lock dependency engine debugging" |
Adrian Bunk | 517e7aa | 2006-07-14 00:24:32 -0700 | [diff] [blame] | 1104 | depends on DEBUG_KERNEL && LOCKDEP |
Ingo Molnar | 4d9f34a | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 1105 | help |
| 1106 | If you say Y here, the lock dependency engine will do |
| 1107 | additional runtime checks to debug itself, at the price |
| 1108 | of more runtime overhead. |
| 1109 | |
Frederic Weisbecker | d902db1 | 2011-06-08 19:31:56 +0200 | [diff] [blame] | 1110 | config DEBUG_ATOMIC_SLEEP |
| 1111 | bool "Sleep inside atomic section checking" |
Frederic Weisbecker | e8f7c70 | 2011-06-08 01:51:02 +0200 | [diff] [blame] | 1112 | select PREEMPT_COUNT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | depends on DEBUG_KERNEL |
| 1114 | help |
| 1115 | 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] | 1116 | noisy if they are called inside atomic sections: when a spinlock is |
| 1117 | held, inside an rcu read side critical section, inside preempt disabled |
| 1118 | sections, inside an interrupt, etc... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1119 | |
Ingo Molnar | cae2ed9 | 2006-07-03 00:24:48 -0700 | [diff] [blame] | 1120 | config DEBUG_LOCKING_API_SELFTESTS |
| 1121 | bool "Locking API boot-time self-tests" |
| 1122 | depends on DEBUG_KERNEL |
| 1123 | help |
| 1124 | Say Y here if you want the kernel to run a short self-test during |
| 1125 | bootup. The self-test checks whether common types of locking bugs |
| 1126 | are detected by debugging mechanisms or not. (if you disable |
| 1127 | lock debugging then those bugs wont be detected of course.) |
| 1128 | The following locking APIs are covered: spinlocks, rwlocks, |
| 1129 | mutexes and rwsems. |
| 1130 | |
Paul E. McKenney | 0af3fe1 | 2014-02-04 15:51:41 -0800 | [diff] [blame] | 1131 | config LOCK_TORTURE_TEST |
| 1132 | tristate "torture tests for locking" |
| 1133 | depends on DEBUG_KERNEL |
| 1134 | select TORTURE_TEST |
| 1135 | default n |
| 1136 | help |
| 1137 | This option provides a kernel module that runs torture tests |
| 1138 | on kernel locking primitives. The kernel module may be built |
| 1139 | after the fact on the running kernel to be tested, if desired. |
| 1140 | |
| 1141 | Say Y here if you want kernel locking-primitive torture tests |
| 1142 | to be built into the kernel. |
| 1143 | Say M if you want these torture tests to build as a module. |
| 1144 | Say N if you are unsure. |
| 1145 | |
Dave Hansen | 9eade16 | 2013-07-01 13:04:47 -0700 | [diff] [blame] | 1146 | endmenu # lock debugging |
| 1147 | |
| 1148 | config TRACE_IRQFLAGS |
| 1149 | bool |
| 1150 | help |
| 1151 | Enables hooks to interrupt enabling and disabling for |
| 1152 | either tracing or lock debugging. |
| 1153 | |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 1154 | config STACKTRACE |
Dave Jones | 0c38e1f | 2014-08-29 15:18:35 -0700 | [diff] [blame] | 1155 | bool "Stack backtrace support" |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 1156 | depends on STACKTRACE_SUPPORT |
Dave Jones | 0c38e1f | 2014-08-29 15:18:35 -0700 | [diff] [blame] | 1157 | help |
| 1158 | This option causes the kernel to create a /proc/pid/stack for |
| 1159 | every process, showing its current stack trace. |
| 1160 | It is also used by various kernel debugging features that require |
| 1161 | stack trace generation. |
Ingo Molnar | 8637c09 | 2006-07-03 00:24:38 -0700 | [diff] [blame] | 1162 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | config DEBUG_KOBJECT |
| 1164 | bool "kobject debugging" |
| 1165 | depends on DEBUG_KERNEL |
| 1166 | help |
| 1167 | If you say Y here, some extra kobject debugging messages will be sent |
| 1168 | to the syslog. |
| 1169 | |
Russell King | c817a67 | 2013-06-27 15:06:14 +0100 | [diff] [blame] | 1170 | config DEBUG_KOBJECT_RELEASE |
| 1171 | bool "kobject release debugging" |
Linus Torvalds | 2a999aa | 2013-10-29 08:33:36 -0700 | [diff] [blame] | 1172 | depends on DEBUG_OBJECTS_TIMERS |
Russell King | c817a67 | 2013-06-27 15:06:14 +0100 | [diff] [blame] | 1173 | help |
| 1174 | kobjects are reference counted objects. This means that their |
| 1175 | last reference count put is not predictable, and the kobject can |
| 1176 | live on past the point at which a driver decides to drop it's |
| 1177 | initial reference to the kobject gained on allocation. An |
| 1178 | example of this would be a struct device which has just been |
| 1179 | unregistered. |
| 1180 | |
| 1181 | However, some buggy drivers assume that after such an operation, |
| 1182 | the memory backing the kobject can be immediately freed. This |
| 1183 | goes completely against the principles of a refcounted object. |
| 1184 | |
| 1185 | If you say Y here, the kernel will delay the release of kobjects |
| 1186 | on the last reference count to improve the visibility of this |
| 1187 | kind of kobject release bug. |
| 1188 | |
Catalin Marinas | 9b2a60c | 2012-10-08 16:28:13 -0700 | [diff] [blame] | 1189 | config HAVE_DEBUG_BUGVERBOSE |
| 1190 | bool |
| 1191 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | config DEBUG_BUGVERBOSE |
David Rientjes | 6a108a1 | 2011-01-20 14:44:16 -0800 | [diff] [blame] | 1193 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT |
Catalin Marinas | 9b2a60c | 2012-10-08 16:28:13 -0700 | [diff] [blame] | 1194 | depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) |
Alexey Dobriyan | 8420e7e | 2009-12-14 18:00:25 -0800 | [diff] [blame] | 1195 | default y |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | help |
| 1197 | Say Y here to make BUG() panics output the file name and line number |
| 1198 | of the BUG call as well as the EIP and oops trace. This aids |
| 1199 | debugging but costs about 70-100K of memory. |
| 1200 | |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 1201 | config DEBUG_LIST |
| 1202 | bool "Debug linked list manipulation" |
| 1203 | depends on DEBUG_KERNEL |
| 1204 | help |
| 1205 | Enable this to turn on extended checks in the linked-list |
| 1206 | walking routines. |
| 1207 | |
| 1208 | If unsure, say N. |
| 1209 | |
Dan Streetman | b8cfff6 | 2014-06-04 16:11:54 -0700 | [diff] [blame] | 1210 | config DEBUG_PI_LIST |
| 1211 | bool "Debug priority linked list manipulation" |
| 1212 | depends on DEBUG_KERNEL |
| 1213 | help |
| 1214 | Enable this to turn on extended checks in the priority-ordered |
| 1215 | linked-list (plist) walking routines. This checks the entire |
| 1216 | list multiple times during each manipulation. |
| 1217 | |
| 1218 | If unsure, say N. |
| 1219 | |
Jens Axboe | d6ec084 | 2007-10-22 20:01:06 +0200 | [diff] [blame] | 1220 | config DEBUG_SG |
| 1221 | bool "Debug SG table operations" |
| 1222 | depends on DEBUG_KERNEL |
| 1223 | help |
| 1224 | Enable this to turn on checks on scatter-gather tables. This can |
| 1225 | help find problems with drivers that do not properly initialize |
| 1226 | their sg tables. |
| 1227 | |
| 1228 | If unsure, say N. |
| 1229 | |
Arjan van de Ven | 1b2439d | 2008-08-15 15:29:38 -0700 | [diff] [blame] | 1230 | config DEBUG_NOTIFIERS |
| 1231 | bool "Debug notifier call chains" |
| 1232 | depends on DEBUG_KERNEL |
| 1233 | help |
| 1234 | Enable this to turn on sanity checking for notifier call chains. |
| 1235 | This is most useful for kernel developers to make sure that |
| 1236 | modules properly unregister themselves from notifier chains. |
| 1237 | This is a relatively cheap check but if you care about maximum |
| 1238 | performance, say N. |
| 1239 | |
David Howells | e0e8173 | 2009-09-02 09:13:40 +0100 | [diff] [blame] | 1240 | config DEBUG_CREDENTIALS |
| 1241 | bool "Debug credential management" |
| 1242 | depends on DEBUG_KERNEL |
| 1243 | help |
| 1244 | Enable this to turn on some debug checking for credential |
| 1245 | management. The additional code keeps track of the number of |
| 1246 | pointers from task_structs to any given cred struct, and checks to |
| 1247 | see that this number never exceeds the usage count of the cred |
| 1248 | struct. |
| 1249 | |
| 1250 | Furthermore, if SELinux is enabled, this also checks that the |
| 1251 | security pointer in the cred struct is never seen to be invalid. |
| 1252 | |
| 1253 | If unsure, say N. |
| 1254 | |
Dave Hansen | 2f03e3c | 2013-01-07 08:19:23 -0800 | [diff] [blame] | 1255 | menu "RCU Debugging" |
| 1256 | |
| 1257 | config PROVE_RCU |
Paul E. McKenney | 9bae659 | 2015-01-18 18:01:21 -0800 | [diff] [blame] | 1258 | def_bool PROVE_LOCKING |
Dave Hansen | 2f03e3c | 2013-01-07 08:19:23 -0800 | [diff] [blame] | 1259 | |
| 1260 | config PROVE_RCU_REPEATEDLY |
| 1261 | bool "RCU debugging: don't disable PROVE_RCU on first splat" |
| 1262 | depends on PROVE_RCU |
| 1263 | default n |
| 1264 | help |
| 1265 | By itself, PROVE_RCU will disable checking upon issuing the |
| 1266 | first warning (or "splat"). This feature prevents such |
| 1267 | disabling, allowing multiple RCU-lockdep warnings to be printed |
| 1268 | on a single reboot. |
| 1269 | |
| 1270 | Say Y to allow multiple RCU-lockdep warnings per boot. |
| 1271 | |
| 1272 | Say N if you are unsure. |
| 1273 | |
Dave Hansen | 2f03e3c | 2013-01-07 08:19:23 -0800 | [diff] [blame] | 1274 | config SPARSE_RCU_POINTER |
| 1275 | bool "RCU debugging: sparse-based checks for pointer usage" |
| 1276 | default n |
| 1277 | help |
| 1278 | This feature enables the __rcu sparse annotation for |
| 1279 | RCU-protected pointers. This annotation will cause sparse |
| 1280 | to flag any non-RCU used of annotated pointers. This can be |
| 1281 | helpful when debugging RCU usage. Please note that this feature |
| 1282 | is not intended to enforce code cleanliness; it is instead merely |
| 1283 | a debugging aid. |
| 1284 | |
| 1285 | Say Y to make sparse flag questionable use of RCU-protected pointers |
| 1286 | |
| 1287 | Say N if you are unsure. |
| 1288 | |
Paul E. McKenney | 51b1130 | 2014-01-27 11:49:39 -0800 | [diff] [blame] | 1289 | config TORTURE_TEST |
| 1290 | tristate |
| 1291 | default n |
| 1292 | |
Paul E. McKenney | 8704baa | 2015-12-31 18:33:22 -0800 | [diff] [blame] | 1293 | config RCU_PERF_TEST |
| 1294 | tristate "performance tests for RCU" |
| 1295 | depends on DEBUG_KERNEL |
| 1296 | select TORTURE_TEST |
| 1297 | select SRCU |
| 1298 | select TASKS_RCU |
| 1299 | default n |
| 1300 | help |
| 1301 | This option provides a kernel module that runs performance |
| 1302 | tests on the RCU infrastructure. The kernel module may be built |
| 1303 | after the fact on the running kernel to be tested, if desired. |
| 1304 | |
| 1305 | Say Y here if you want RCU performance tests to be built into |
| 1306 | the kernel. |
| 1307 | Say M if you want the RCU performance tests to build as a module. |
| 1308 | Say N if you are unsure. |
| 1309 | |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 1310 | config RCU_TORTURE_TEST |
| 1311 | tristate "torture tests for RCU" |
| 1312 | depends on DEBUG_KERNEL |
Paul E. McKenney | 51b1130 | 2014-01-27 11:49:39 -0800 | [diff] [blame] | 1313 | select TORTURE_TEST |
Pranith Kumar | 83fe27e | 2014-12-05 11:24:45 -0500 | [diff] [blame] | 1314 | select SRCU |
Paul E. McKenney | 82d0f4c | 2015-04-20 05:42:50 -0700 | [diff] [blame] | 1315 | select TASKS_RCU |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 1316 | default n |
| 1317 | help |
| 1318 | This option provides a kernel module that runs torture tests |
| 1319 | on the RCU infrastructure. The kernel module may be built |
| 1320 | after the fact on the running kernel to be tested, if desired. |
| 1321 | |
Paul E. McKenney | 31a72bc | 2008-06-18 09:26:49 -0700 | [diff] [blame] | 1322 | Say Y here if you want RCU torture tests to be built into |
| 1323 | the kernel. |
Paul E. McKenney | a241ec6 | 2005-10-30 15:03:12 -0800 | [diff] [blame] | 1324 | Say M if you want the RCU torture tests to build as a module. |
| 1325 | Say N if you are unsure. |
Ankita Garg | 8bb31b9 | 2006-10-02 02:17:36 -0700 | [diff] [blame] | 1326 | |
Paul E. McKenney | 0f41c0d | 2015-03-10 18:33:20 -0700 | [diff] [blame] | 1327 | config RCU_TORTURE_TEST_SLOW_PREINIT |
| 1328 | bool "Slow down RCU grace-period pre-initialization to expose races" |
| 1329 | depends on RCU_TORTURE_TEST |
| 1330 | help |
| 1331 | This option delays grace-period pre-initialization (the |
| 1332 | propagation of CPU-hotplug changes up the rcu_node combining |
| 1333 | tree) for a few jiffies between initializing each pair of |
| 1334 | consecutive rcu_node structures. This helps to expose races |
| 1335 | involving grace-period pre-initialization, in other words, it |
| 1336 | makes your kernel less stable. It can also greatly increase |
| 1337 | grace-period latency, especially on systems with large numbers |
| 1338 | of CPUs. This is useful when torture-testing RCU, but in |
| 1339 | almost no other circumstance. |
| 1340 | |
| 1341 | Say Y here if you want your system to crash and hang more often. |
| 1342 | Say N if you want a sane system. |
| 1343 | |
| 1344 | config RCU_TORTURE_TEST_SLOW_PREINIT_DELAY |
| 1345 | int "How much to slow down RCU grace-period pre-initialization" |
| 1346 | range 0 5 |
| 1347 | default 3 |
| 1348 | depends on RCU_TORTURE_TEST_SLOW_PREINIT |
| 1349 | help |
| 1350 | This option specifies the number of jiffies to wait between |
| 1351 | each rcu_node structure pre-initialization step. |
| 1352 | |
Paul E. McKenney | 37745d2 | 2015-01-22 18:24:08 -0800 | [diff] [blame] | 1353 | config RCU_TORTURE_TEST_SLOW_INIT |
| 1354 | bool "Slow down RCU grace-period initialization to expose races" |
| 1355 | depends on RCU_TORTURE_TEST |
| 1356 | help |
Paul E. McKenney | 0f41c0d | 2015-03-10 18:33:20 -0700 | [diff] [blame] | 1357 | This option delays grace-period initialization for a few |
| 1358 | jiffies between initializing each pair of consecutive |
Paul E. McKenney | 37745d2 | 2015-01-22 18:24:08 -0800 | [diff] [blame] | 1359 | rcu_node structures. This helps to expose races involving |
| 1360 | grace-period initialization, in other words, it makes your |
| 1361 | kernel less stable. It can also greatly increase grace-period |
| 1362 | latency, especially on systems with large numbers of CPUs. |
| 1363 | This is useful when torture-testing RCU, but in almost no |
| 1364 | other circumstance. |
| 1365 | |
| 1366 | Say Y here if you want your system to crash and hang more often. |
| 1367 | Say N if you want a sane system. |
| 1368 | |
| 1369 | config RCU_TORTURE_TEST_SLOW_INIT_DELAY |
| 1370 | int "How much to slow down RCU grace-period initialization" |
| 1371 | range 0 5 |
Paul E. McKenney | 186bea5 | 2015-01-29 16:37:19 -0800 | [diff] [blame] | 1372 | default 3 |
Paul E. McKenney | 8d7dc92 | 2015-04-14 19:33:59 -0700 | [diff] [blame] | 1373 | depends on RCU_TORTURE_TEST_SLOW_INIT |
Paul E. McKenney | 37745d2 | 2015-01-22 18:24:08 -0800 | [diff] [blame] | 1374 | help |
| 1375 | This option specifies the number of jiffies to wait between |
| 1376 | each rcu_node structure initialization. |
| 1377 | |
Paul E. McKenney | 0f41c0d | 2015-03-10 18:33:20 -0700 | [diff] [blame] | 1378 | config RCU_TORTURE_TEST_SLOW_CLEANUP |
| 1379 | bool "Slow down RCU grace-period cleanup to expose races" |
| 1380 | depends on RCU_TORTURE_TEST |
| 1381 | help |
| 1382 | This option delays grace-period cleanup for a few jiffies |
| 1383 | between cleaning up each pair of consecutive rcu_node |
| 1384 | structures. This helps to expose races involving grace-period |
| 1385 | cleanup, in other words, it makes your kernel less stable. |
| 1386 | It can also greatly increase grace-period latency, especially |
| 1387 | on systems with large numbers of CPUs. This is useful when |
| 1388 | torture-testing RCU, but in almost no other circumstance. |
| 1389 | |
| 1390 | Say Y here if you want your system to crash and hang more often. |
| 1391 | Say N if you want a sane system. |
| 1392 | |
| 1393 | config RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY |
| 1394 | int "How much to slow down RCU grace-period cleanup" |
| 1395 | range 0 5 |
| 1396 | default 3 |
| 1397 | depends on RCU_TORTURE_TEST_SLOW_CLEANUP |
| 1398 | help |
| 1399 | This option specifies the number of jiffies to wait between |
| 1400 | each rcu_node structure cleanup operation. |
| 1401 | |
Paul E. McKenney | b163760 | 2010-06-02 16:21:38 -0700 | [diff] [blame] | 1402 | config RCU_CPU_STALL_TIMEOUT |
| 1403 | int "RCU CPU stall timeout in seconds" |
Paul E. McKenney | 6bfc09e | 2012-10-19 12:49:17 -0700 | [diff] [blame] | 1404 | depends on RCU_STALL_COMMON |
Paul E. McKenney | b163760 | 2010-06-02 16:21:38 -0700 | [diff] [blame] | 1405 | range 3 300 |
Paul E. McKenney | c896054 | 2012-10-25 17:59:23 -0700 | [diff] [blame] | 1406 | default 21 |
Paul E. McKenney | b163760 | 2010-06-02 16:21:38 -0700 | [diff] [blame] | 1407 | help |
| 1408 | If a given RCU grace period extends more than the specified |
| 1409 | number of seconds, a CPU stall warning is printed. If the |
| 1410 | RCU grace period persists, additional CPU stall warnings are |
| 1411 | printed at more widely spaced intervals. |
| 1412 | |
Paul E. McKenney | 5c8806a | 2012-01-06 15:10:44 -0800 | [diff] [blame] | 1413 | config RCU_TRACE |
| 1414 | bool "Enable tracing for RCU" |
| 1415 | depends on DEBUG_KERNEL |
Paul E. McKenney | 5249453 | 2012-11-14 16:26:40 -0800 | [diff] [blame] | 1416 | select TRACE_CLOCK |
Paul E. McKenney | 5c8806a | 2012-01-06 15:10:44 -0800 | [diff] [blame] | 1417 | help |
| 1418 | This option provides tracing in RCU which presents stats |
| 1419 | in debugfs for debugging RCU implementation. |
| 1420 | |
| 1421 | Say Y here if you want to enable RCU tracing |
| 1422 | Say N if you are unsure. |
| 1423 | |
Paul E. McKenney | 1ce46ee | 2015-05-05 23:04:22 -0700 | [diff] [blame] | 1424 | config RCU_EQS_DEBUG |
Paul E. McKenney | eb6d5b0 | 2015-06-30 09:56:31 -0700 | [diff] [blame] | 1425 | bool "Provide debugging asserts for adding NO_HZ support to an arch" |
Paul E. McKenney | 1ce46ee | 2015-05-05 23:04:22 -0700 | [diff] [blame] | 1426 | depends on DEBUG_KERNEL |
| 1427 | help |
| 1428 | This option provides consistency checks in RCU's handling of |
| 1429 | NO_HZ. These checks have proven quite helpful in detecting |
| 1430 | bugs in arch-specific NO_HZ code. |
| 1431 | |
| 1432 | Say N here if you need ultimate kernel/user switch latencies |
| 1433 | Say Y if you are unsure |
| 1434 | |
Dave Hansen | 2f03e3c | 2013-01-07 08:19:23 -0800 | [diff] [blame] | 1435 | endmenu # "RCU Debugging" |
| 1436 | |
Tejun Heo | f303fcc | 2016-02-09 17:59:38 -0500 | [diff] [blame] | 1437 | config DEBUG_WQ_FORCE_RR_CPU |
| 1438 | bool "Force round-robin CPU selection for unbound work items" |
| 1439 | depends on DEBUG_KERNEL |
| 1440 | default n |
| 1441 | help |
| 1442 | Workqueue used to implicitly guarantee that work items queued |
| 1443 | without explicit CPU specified are put on the local CPU. This |
| 1444 | guarantee is no longer true and while local CPU is still |
| 1445 | preferred work items may be put on foreign CPUs. Kernel |
| 1446 | parameter "workqueue.debug_force_rr_cpu" is added to force |
| 1447 | round-robin CPU selection to flush out usages which depend on the |
| 1448 | now broken guarantee. This config option enables the debug |
| 1449 | feature by default. When enabled, memory and cache locality will |
| 1450 | be impacted. |
| 1451 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1452 | config DEBUG_BLOCK_EXT_DEVT |
| 1453 | bool "Force extended block device numbers and spread them" |
| 1454 | depends on DEBUG_KERNEL |
| 1455 | depends on BLOCK |
Jens Axboe | 759f8ca | 2008-08-29 09:06:29 +0200 | [diff] [blame] | 1456 | default n |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1457 | help |
Tejun Heo | 0e11e34 | 2008-10-13 10:46:01 +0200 | [diff] [blame] | 1458 | BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
| 1459 | SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
| 1460 | YOU ARE DOING. Distros, please enable this and fix whatever |
| 1461 | is broken. |
| 1462 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1463 | Conventionally, block device numbers are allocated from |
| 1464 | predetermined contiguous area. However, extended block area |
| 1465 | may introduce non-contiguous block device numbers. This |
| 1466 | option forces most block device numbers to be allocated from |
| 1467 | the extended space and spreads them to discover kernel or |
| 1468 | userland code paths which assume predetermined contiguous |
| 1469 | device number allocation. |
| 1470 | |
Tejun Heo | 55dc7db | 2008-09-01 13:44:35 +0200 | [diff] [blame] | 1471 | Note that turning on this debug option shuffles all the |
| 1472 | device numbers for all IDE and SCSI devices including libata |
| 1473 | ones, so root partition specified using device number |
| 1474 | directly (via rdev or root=MAJ:MIN) won't work anymore. |
| 1475 | Textual device names (root=/dev/sdXn) will continue to work. |
| 1476 | |
Tejun Heo | 870d665 | 2008-08-25 19:47:25 +0900 | [diff] [blame] | 1477 | Say N if you are unsure. |
| 1478 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1479 | config CPU_HOTPLUG_STATE_CONTROL |
| 1480 | bool "Enable CPU hotplug state control" |
| 1481 | depends on DEBUG_KERNEL |
| 1482 | depends on HOTPLUG_CPU |
| 1483 | default n |
| 1484 | help |
| 1485 | Allows to write steps between "offline" and "online" to the CPUs |
| 1486 | sysfs target file so states can be stepped granular. This is a debug |
| 1487 | option for now as the hotplug machinery cannot be stopped and |
| 1488 | restarted at arbitrary points yet. |
| 1489 | |
| 1490 | Say N if your are unsure. |
| 1491 | |
Akinobu Mita | 8d43828 | 2012-07-30 14:43:02 -0700 | [diff] [blame] | 1492 | config NOTIFIER_ERROR_INJECTION |
| 1493 | tristate "Notifier error injection" |
| 1494 | depends on DEBUG_KERNEL |
| 1495 | select DEBUG_FS |
| 1496 | help |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1497 | This option provides the ability to inject artificial errors to |
Akinobu Mita | 8d43828 | 2012-07-30 14:43:02 -0700 | [diff] [blame] | 1498 | specified notifier chain callbacks. It is useful to test the error |
| 1499 | handling of notifier call chain failures. |
| 1500 | |
| 1501 | Say N if unsure. |
| 1502 | |
Akinobu Mita | c9d221f | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 1503 | config CPU_NOTIFIER_ERROR_INJECT |
| 1504 | tristate "CPU notifier error injection module" |
Akinobu Mita | f5a9f52 | 2012-07-30 14:43:03 -0700 | [diff] [blame] | 1505 | depends on HOTPLUG_CPU && NOTIFIER_ERROR_INJECTION |
Akinobu Mita | c9d221f | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 1506 | help |
| 1507 | This option provides a kernel module that can be used to test |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1508 | the error handling of the cpu notifiers by injecting artificial |
Akinobu Mita | f5a9f52 | 2012-07-30 14:43:03 -0700 | [diff] [blame] | 1509 | errors to CPU notifier chain callbacks. It is controlled through |
| 1510 | debugfs interface under /sys/kernel/debug/notifier-error-inject/cpu |
| 1511 | |
| 1512 | If the notifier call chain should be failed with some events |
| 1513 | notified, write the error code to "actions/<notifier event>/error". |
| 1514 | |
| 1515 | Example: Inject CPU offline error (-1 == -EPERM) |
| 1516 | |
| 1517 | # cd /sys/kernel/debug/notifier-error-inject/cpu |
| 1518 | # echo -1 > actions/CPU_DOWN_PREPARE/error |
| 1519 | # echo 0 > /sys/devices/system/cpu/cpu1/online |
| 1520 | bash: echo: write error: Operation not permitted |
Akinobu Mita | c9d221f | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 1521 | |
| 1522 | To compile this code as a module, choose M here: the module will |
| 1523 | be called cpu-notifier-error-inject. |
| 1524 | |
| 1525 | If unsure, say N. |
| 1526 | |
Akinobu Mita | 048b9c3 | 2012-07-30 14:43:07 -0700 | [diff] [blame] | 1527 | config PM_NOTIFIER_ERROR_INJECT |
| 1528 | tristate "PM notifier error injection module" |
| 1529 | depends on PM && NOTIFIER_ERROR_INJECTION |
| 1530 | default m if PM_DEBUG |
| 1531 | help |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1532 | This option provides the ability to inject artificial errors to |
Akinobu Mita | 048b9c3 | 2012-07-30 14:43:07 -0700 | [diff] [blame] | 1533 | PM notifier chain callbacks. It is controlled through debugfs |
| 1534 | interface /sys/kernel/debug/notifier-error-inject/pm |
| 1535 | |
| 1536 | If the notifier call chain should be failed with some events |
| 1537 | notified, write the error code to "actions/<notifier event>/error". |
| 1538 | |
| 1539 | Example: Inject PM suspend error (-12 = -ENOMEM) |
| 1540 | |
| 1541 | # cd /sys/kernel/debug/notifier-error-inject/pm/ |
| 1542 | # echo -12 > actions/PM_SUSPEND_PREPARE/error |
| 1543 | # echo mem > /sys/power/state |
| 1544 | bash: echo: write error: Cannot allocate memory |
| 1545 | |
| 1546 | To compile this code as a module, choose M here: the module will |
| 1547 | be called pm-notifier-error-inject. |
| 1548 | |
| 1549 | If unsure, say N. |
| 1550 | |
Benjamin Herrenschmidt | d526e85 | 2012-12-14 10:32:52 +1100 | [diff] [blame] | 1551 | config OF_RECONFIG_NOTIFIER_ERROR_INJECT |
| 1552 | tristate "OF reconfig notifier error injection module" |
| 1553 | depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1554 | help |
Masanari Iida | e41e85c | 2012-11-30 16:44:39 +0900 | [diff] [blame] | 1555 | This option provides the ability to inject artificial errors to |
Benjamin Herrenschmidt | d526e85 | 2012-12-14 10:32:52 +1100 | [diff] [blame] | 1556 | OF reconfig notifier chain callbacks. It is controlled |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1557 | through debugfs interface under |
Benjamin Herrenschmidt | d526e85 | 2012-12-14 10:32:52 +1100 | [diff] [blame] | 1558 | /sys/kernel/debug/notifier-error-inject/OF-reconfig/ |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1559 | |
| 1560 | If the notifier call chain should be failed with some events |
| 1561 | notified, write the error code to "actions/<notifier event>/error". |
| 1562 | |
| 1563 | 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] | 1564 | be called of-reconfig-notifier-error-inject. |
Akinobu Mita | 08dfb4d | 2012-07-30 14:43:13 -0700 | [diff] [blame] | 1565 | |
| 1566 | If unsure, say N. |
| 1567 | |
Nikolay Aleksandrov | 02fff96 | 2015-11-28 13:45:28 +0100 | [diff] [blame] | 1568 | config NETDEV_NOTIFIER_ERROR_INJECT |
| 1569 | tristate "Netdev notifier error injection module" |
| 1570 | depends on NET && NOTIFIER_ERROR_INJECTION |
| 1571 | help |
| 1572 | This option provides the ability to inject artificial errors to |
| 1573 | netdevice notifier chain callbacks. It is controlled through debugfs |
| 1574 | interface /sys/kernel/debug/notifier-error-inject/netdev |
| 1575 | |
| 1576 | If the notifier call chain should be failed with some events |
| 1577 | notified, write the error code to "actions/<notifier event>/error". |
| 1578 | |
| 1579 | Example: Inject netdevice mtu change error (-22 = -EINVAL) |
| 1580 | |
| 1581 | # cd /sys/kernel/debug/notifier-error-inject/netdev |
| 1582 | # echo -22 > actions/NETDEV_CHANGEMTU/error |
| 1583 | # ip link set eth0 mtu 1024 |
| 1584 | RTNETLINK answers: Invalid argument |
| 1585 | |
| 1586 | To compile this code as a module, choose M here: the module will |
| 1587 | be called netdev-notifier-error-inject. |
| 1588 | |
| 1589 | If unsure, say N. |
| 1590 | |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1591 | config FAULT_INJECTION |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1592 | bool "Fault-injection framework" |
| 1593 | depends on DEBUG_KERNEL |
Akinobu Mita | 329409a | 2006-12-08 02:39:48 -0800 | [diff] [blame] | 1594 | help |
| 1595 | Provide fault-injection framework. |
| 1596 | For more details, see Documentation/fault-injection/. |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1597 | |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 1598 | config FAILSLAB |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1599 | bool "Fault-injection capability for kmalloc" |
| 1600 | depends on FAULT_INJECTION |
Akinobu Mita | 773ff60 | 2008-12-23 19:37:01 +0900 | [diff] [blame] | 1601 | depends on SLAB || SLUB |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 1602 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1603 | Provide fault-injection capability for kmalloc. |
Akinobu Mita | 8a8b650 | 2006-12-08 02:39:44 -0800 | [diff] [blame] | 1604 | |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 1605 | config FAIL_PAGE_ALLOC |
| 1606 | bool "Fault-injection capabilitiy for alloc_pages()" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1607 | depends on FAULT_INJECTION |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 1608 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1609 | Provide fault-injection capability for alloc_pages(). |
Akinobu Mita | 933e312 | 2006-12-08 02:39:45 -0800 | [diff] [blame] | 1610 | |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 1611 | config FAIL_MAKE_REQUEST |
Dave Jones | 86327d1 | 2006-12-12 20:16:36 +0100 | [diff] [blame] | 1612 | bool "Fault-injection capability for disk IO" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 1613 | depends on FAULT_INJECTION && BLOCK |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 1614 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1615 | Provide fault-injection capability for disk IO. |
Akinobu Mita | c17bb49 | 2006-12-08 02:39:46 -0800 | [diff] [blame] | 1616 | |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 1617 | config FAIL_IO_TIMEOUT |
Takuya Yoshikawa | f4d01439 | 2010-07-21 16:05:53 +0900 | [diff] [blame] | 1618 | bool "Fault-injection capability for faking disk interrupts" |
Jens Axboe | 581d4e2 | 2008-09-14 05:56:33 -0700 | [diff] [blame] | 1619 | depends on FAULT_INJECTION && BLOCK |
| 1620 | help |
| 1621 | Provide fault-injection capability on end IO handling. This |
| 1622 | will make the block layer "forget" an interrupt as configured, |
| 1623 | thus exercising the error handling. |
| 1624 | |
| 1625 | Only works with drivers that use the generic timeout handling, |
| 1626 | for others it wont do anything. |
| 1627 | |
Per Forlin | 1b676f7 | 2011-08-19 14:52:37 +0200 | [diff] [blame] | 1628 | config FAIL_MMC_REQUEST |
| 1629 | bool "Fault-injection capability for MMC IO" |
Adrien Schildknecht | 28ff4fd | 2015-11-10 20:12:19 +0100 | [diff] [blame] | 1630 | depends on FAULT_INJECTION_DEBUG_FS && MMC |
Per Forlin | 1b676f7 | 2011-08-19 14:52:37 +0200 | [diff] [blame] | 1631 | help |
| 1632 | Provide fault-injection capability for MMC IO. |
| 1633 | This will make the mmc core return data errors. This is |
| 1634 | useful to test the error handling in the mmc block device |
| 1635 | and to test how the mmc host driver handles retries from |
| 1636 | the block device. |
| 1637 | |
Davidlohr Bueso | ab51fba | 2015-06-29 23:26:02 -0700 | [diff] [blame] | 1638 | config FAIL_FUTEX |
| 1639 | bool "Fault-injection capability for futexes" |
| 1640 | select DEBUG_FS |
| 1641 | depends on FAULT_INJECTION && FUTEX |
| 1642 | help |
| 1643 | Provide fault-injection capability for futexes. |
| 1644 | |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1645 | config FAULT_INJECTION_DEBUG_FS |
| 1646 | bool "Debugfs entries for fault-injection capabilities" |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1647 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
Akinobu Mita | 6ff1cb3 | 2006-12-08 02:39:43 -0800 | [diff] [blame] | 1648 | help |
Andrew Morton | 1ab8509a | 2006-12-08 02:39:49 -0800 | [diff] [blame] | 1649 | Enable configuration of fault-injection capabilities via debugfs. |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 1650 | |
| 1651 | config FAULT_INJECTION_STACKTRACE_FILTER |
| 1652 | bool "stacktrace filter for fault-injection capabilities" |
| 1653 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
Akinobu Mita | 6d690dc | 2007-05-12 10:36:53 -0700 | [diff] [blame] | 1654 | depends on !X86_64 |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 1655 | select STACKTRACE |
Chen Gang | df2e1ef | 2014-06-23 13:22:04 -0700 | [diff] [blame] | 1656 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC && !SCORE |
Akinobu Mita | 1df4900 | 2007-02-20 13:57:56 -0800 | [diff] [blame] | 1657 | help |
| 1658 | Provide stacktrace filter for fault-injection capabilities |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 1659 | |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1660 | config LATENCYTOP |
| 1661 | bool "Latency measuring infrastructure" |
Randy Dunlap | 625fdca | 2010-08-12 12:31:21 -0700 | [diff] [blame] | 1662 | depends on DEBUG_KERNEL |
| 1663 | depends on STACKTRACE_SUPPORT |
| 1664 | depends on PROC_FS |
Vineet Gupta | cc80ae3 | 2013-08-27 13:52:51 +0530 | [diff] [blame] | 1665 | select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1666 | select KALLSYMS |
| 1667 | select KALLSYMS_ALL |
| 1668 | select STACKTRACE |
| 1669 | select SCHEDSTATS |
| 1670 | select SCHED_DEBUG |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1671 | help |
| 1672 | Enable this option if you want to use the LatencyTOP tool |
| 1673 | to find out which userspace is blocking on what kernel operations. |
| 1674 | |
Stephen Boyd | 446f24d | 2013-04-30 15:28:42 -0700 | [diff] [blame] | 1675 | config ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS |
| 1676 | bool |
| 1677 | |
| 1678 | config DEBUG_STRICT_USER_COPY_CHECKS |
| 1679 | bool "Strict user copy size checks" |
| 1680 | depends on ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS |
| 1681 | depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING |
| 1682 | help |
| 1683 | Enabling this option turns a certain set of sanity checks for user |
| 1684 | copy operations into compile time failures. |
| 1685 | |
| 1686 | The copy_from_user() etc checks are there to help test if there |
| 1687 | are sufficient security checks on the length argument of |
| 1688 | the copy operation, by having gcc prove that the argument is |
| 1689 | within bounds. |
| 1690 | |
| 1691 | If unsure, say N. |
| 1692 | |
Arnaldo Carvalho de Melo | 16444a8 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 1693 | source kernel/trace/Kconfig |
| 1694 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1695 | menu "Runtime Testing" |
| 1696 | |
| 1697 | config LKDTM |
| 1698 | tristate "Linux Kernel Dump Test Tool Module" |
| 1699 | depends on DEBUG_FS |
| 1700 | depends on BLOCK |
| 1701 | default n |
| 1702 | help |
| 1703 | This module enables testing of the different dumping mechanisms by |
| 1704 | inducing system failures at predefined crash points. |
| 1705 | If you don't need it: say N |
| 1706 | Choose M here to compile this code as a module. The module will be |
| 1707 | called lkdtm. |
| 1708 | |
| 1709 | Documentation on how to use the module can be found in |
| 1710 | Documentation/fault-injection/provoke-crashes.txt |
| 1711 | |
| 1712 | config TEST_LIST_SORT |
| 1713 | bool "Linked list sorting test" |
| 1714 | depends on DEBUG_KERNEL |
| 1715 | help |
| 1716 | Enable this to turn on 'list_sort()' function test. This test is |
| 1717 | executed only once during system boot, so affects only boot time. |
| 1718 | |
| 1719 | If unsure, say N. |
| 1720 | |
| 1721 | config KPROBES_SANITY_TEST |
| 1722 | bool "Kprobes sanity tests" |
| 1723 | depends on DEBUG_KERNEL |
| 1724 | depends on KPROBES |
| 1725 | default n |
| 1726 | help |
| 1727 | This option provides for testing basic kprobes functionality on |
| 1728 | boot. A sample kprobe, jprobe and kretprobe are inserted and |
| 1729 | verified for functionality. |
| 1730 | |
| 1731 | Say N if you are unsure. |
| 1732 | |
| 1733 | config BACKTRACE_SELF_TEST |
| 1734 | tristate "Self test for the backtrace code" |
| 1735 | depends on DEBUG_KERNEL |
| 1736 | default n |
| 1737 | help |
| 1738 | This option provides a kernel module that can be used to test |
| 1739 | the kernel stack backtrace code. This option is not useful |
| 1740 | for distributions or general kernels, but only for kernel |
| 1741 | developers working on architecture code. |
| 1742 | |
| 1743 | Note that if you want to also test saved backtraces, you will |
| 1744 | have to enable STACKTRACE as well. |
| 1745 | |
| 1746 | Say N if you are unsure. |
| 1747 | |
Michel Lespinasse | 910a742 | 2012-10-08 16:30:39 -0700 | [diff] [blame] | 1748 | config RBTREE_TEST |
| 1749 | tristate "Red-Black tree test" |
Cody P Schafer | 7c993e1 | 2013-09-11 14:25:19 -0700 | [diff] [blame] | 1750 | depends on DEBUG_KERNEL |
Michel Lespinasse | 910a742 | 2012-10-08 16:30:39 -0700 | [diff] [blame] | 1751 | help |
| 1752 | A benchmark measuring the performance of the rbtree library. |
| 1753 | Also includes rbtree invariant checks. |
| 1754 | |
Michel Lespinasse | fff3fd8 | 2012-10-08 16:31:23 -0700 | [diff] [blame] | 1755 | config INTERVAL_TREE_TEST |
| 1756 | tristate "Interval tree test" |
| 1757 | depends on m && DEBUG_KERNEL |
Chris Wilson | a88cc10 | 2014-03-17 12:21:54 +0000 | [diff] [blame] | 1758 | select INTERVAL_TREE |
Michel Lespinasse | fff3fd8 | 2012-10-08 16:31:23 -0700 | [diff] [blame] | 1759 | help |
| 1760 | A benchmark measuring the performance of the interval tree library |
| 1761 | |
Greg Thelen | 623fd80 | 2013-11-12 15:08:34 -0800 | [diff] [blame] | 1762 | config PERCPU_TEST |
| 1763 | tristate "Per cpu operations test" |
| 1764 | depends on m && DEBUG_KERNEL |
| 1765 | help |
| 1766 | Enable this option to build test module which validates per-cpu |
| 1767 | operations. |
| 1768 | |
| 1769 | If unsure, say N. |
| 1770 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1771 | config ATOMIC64_SELFTEST |
| 1772 | bool "Perform an atomic64_t self-test at boot" |
| 1773 | help |
| 1774 | Enable this option to test the atomic64_t functions at boot. |
| 1775 | |
| 1776 | If unsure, say N. |
| 1777 | |
| 1778 | config ASYNC_RAID6_TEST |
| 1779 | tristate "Self test for hardware accelerated raid6 recovery" |
| 1780 | depends on ASYNC_RAID6_RECOV |
| 1781 | select ASYNC_MEMCPY |
| 1782 | ---help--- |
| 1783 | This is a one-shot self test that permutes through the |
| 1784 | recovery of all the possible two disk failure scenarios for a |
| 1785 | N-disk array. Recovery is performed with the asynchronous |
| 1786 | raid6 recovery routines, and will optionally use an offload |
| 1787 | engine if one is available. |
| 1788 | |
| 1789 | If unsure, say N. |
| 1790 | |
Andy Shevchenko | 64d1d77 | 2015-02-12 15:02:21 -0800 | [diff] [blame] | 1791 | config TEST_HEXDUMP |
| 1792 | tristate "Test functions located in the hexdump module at runtime" |
| 1793 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1794 | config TEST_STRING_HELPERS |
| 1795 | tristate "Test functions located in the string_helpers module at runtime" |
| 1796 | |
| 1797 | config TEST_KSTRTOX |
| 1798 | tristate "Test kstrto*() family of functions at runtime" |
| 1799 | |
Rasmus Villemoes | 707cc72 | 2015-11-06 16:30:29 -0800 | [diff] [blame] | 1800 | config TEST_PRINTF |
| 1801 | tristate "Test printf() family of functions at runtime" |
| 1802 | |
David Decotigny | 5fd003f | 2016-02-19 09:24:00 -0500 | [diff] [blame] | 1803 | config TEST_BITMAP |
| 1804 | tristate "Test bitmap_*() family of functions at runtime" |
| 1805 | default n |
| 1806 | help |
| 1807 | Enable this option to test the bitmap functions at boot. |
| 1808 | |
| 1809 | If unsure, say N. |
| 1810 | |
Andy Shevchenko | cfaff0e | 2016-05-30 17:40:41 +0300 | [diff] [blame] | 1811 | config TEST_UUID |
| 1812 | tristate "Test functions located in the uuid module at runtime" |
| 1813 | |
Thomas Graf | 7e1e776 | 2014-08-02 11:47:44 +0200 | [diff] [blame] | 1814 | config TEST_RHASHTABLE |
Geert Uytterhoeven | 9d6dbe1 | 2015-01-29 15:40:25 +0100 | [diff] [blame] | 1815 | tristate "Perform selftest on resizable hash table" |
Thomas Graf | 7e1e776 | 2014-08-02 11:47:44 +0200 | [diff] [blame] | 1816 | default n |
| 1817 | help |
| 1818 | Enable this option to test the rhashtable functions at boot. |
| 1819 | |
| 1820 | If unsure, say N. |
| 1821 | |
George Spelvin | 468a942 | 2016-05-26 22:11:51 -0400 | [diff] [blame] | 1822 | config TEST_HASH |
| 1823 | tristate "Perform selftest on hash functions" |
| 1824 | default n |
| 1825 | help |
| 1826 | Enable this option to test the kernel's integer (<linux/hash,h>) |
| 1827 | and string (<linux/stringhash.h>) hash functions on boot |
| 1828 | (or module load). |
| 1829 | |
| 1830 | This is intended to help people writing architecture-specific |
| 1831 | optimized versions. If unsure, say N. |
| 1832 | |
Dave Hansen | 881c514 | 2013-07-01 13:04:44 -0700 | [diff] [blame] | 1833 | endmenu # runtime tests |
| 1834 | |
Bernhard Kaindl | f212ec4 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 1835 | config PROVIDE_OHCI1394_DMA_INIT |
Stefan Richter | 080de8c | 2008-02-28 20:54:43 +0100 | [diff] [blame] | 1836 | bool "Remote debugging over FireWire early on boot" |
Bernhard Kaindl | f212ec4 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 1837 | depends on PCI && X86 |
| 1838 | help |
| 1839 | If you want to debug problems which hang or crash the kernel early |
| 1840 | on boot and the crashing machine has a FireWire port, you can use |
| 1841 | this feature to remotely access the memory of the crashed machine |
| 1842 | over FireWire. This employs remote DMA as part of the OHCI1394 |
| 1843 | specification which is now the standard for FireWire controllers. |
| 1844 | |
| 1845 | With remote DMA, you can monitor the printk buffer remotely using |
| 1846 | firescope and access all memory below 4GB using fireproxy from gdb. |
| 1847 | Even controlling a kernel debugger is possible using remote DMA. |
| 1848 | |
| 1849 | Usage: |
| 1850 | |
| 1851 | If ohci1394_dma=early is used as boot parameter, it will initialize |
| 1852 | all OHCI1394 controllers which are found in the PCI config space. |
| 1853 | |
| 1854 | As all changes to the FireWire bus such as enabling and disabling |
| 1855 | devices cause a bus reset and thereby disable remote DMA for all |
| 1856 | devices, be sure to have the cable plugged and FireWire enabled on |
| 1857 | the debugging host before booting the debug target for debugging. |
| 1858 | |
| 1859 | This code (~1k) is freed after boot. By then, the firewire stack |
| 1860 | in charge of the OHCI-1394 controllers should be used instead. |
| 1861 | |
| 1862 | See Documentation/debugging-via-ohci1394.txt for more information. |
Arjan van de Ven | 9745512 | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1863 | |
Randy Dunlap | 152de30 | 2009-02-20 15:38:47 -0800 | [diff] [blame] | 1864 | config BUILD_DOCSRC |
Randy Dunlap | 3794f3e | 2008-08-12 15:09:06 -0700 | [diff] [blame] | 1865 | bool "Build targets in Documentation/ tree" |
| 1866 | depends on HEADERS_CHECK |
| 1867 | help |
| 1868 | This option attempts to build objects from the source files in the |
| 1869 | kernel Documentation/ tree. |
| 1870 | |
| 1871 | Say N if you are unsure. |
| 1872 | |
Joerg Roedel | 5ee00bd | 2009-01-09 12:14:24 +0100 | [diff] [blame] | 1873 | config DMA_API_DEBUG |
| 1874 | bool "Enable debugging of DMA-API usage" |
| 1875 | depends on HAVE_DMA_API_DEBUG |
| 1876 | help |
| 1877 | Enable this option to debug the use of the DMA API by device drivers. |
| 1878 | With this option you will be able to detect common bugs in device |
| 1879 | drivers like double-freeing of DMA mappings or freeing mappings that |
| 1880 | were never allocated. |
Dan Williams | 0abdd7a | 2014-01-21 15:48:12 -0800 | [diff] [blame] | 1881 | |
| 1882 | This also attempts to catch cases where a page owned by DMA is |
| 1883 | accessed by the cpu in a way that could cause data corruption. For |
| 1884 | example, this enables cow_user_page() to check that the source page is |
| 1885 | not undergoing DMA. |
| 1886 | |
| 1887 | This option causes a performance degradation. Use only if you want to |
| 1888 | debug device drivers and dma interactions. |
| 1889 | |
| 1890 | If unsure, say N. |
Jason Baron | 346e15b | 2008-08-12 16:46:19 -0400 | [diff] [blame] | 1891 | |
Valentin Rothberg | 8a6f0b4 | 2014-10-13 15:51:38 -0700 | [diff] [blame] | 1892 | config TEST_LKM |
Kees Cook | 93e9ef8 | 2014-01-23 15:54:37 -0800 | [diff] [blame] | 1893 | tristate "Test module loading with 'hello world' module" |
| 1894 | default n |
| 1895 | depends on m |
| 1896 | help |
| 1897 | This builds the "test_module" module that emits "Hello, world" |
| 1898 | on printk when loaded. It is designed to be used for basic |
| 1899 | evaluation of the module loading subsystem (for example when |
| 1900 | validating module verification). It lacks any extra dependencies, |
| 1901 | and will not normally be loaded by the system unless explicitly |
| 1902 | requested by name. |
| 1903 | |
| 1904 | If unsure, say N. |
| 1905 | |
Kees Cook | 3e2a4c1 | 2014-01-23 15:54:38 -0800 | [diff] [blame] | 1906 | config TEST_USER_COPY |
| 1907 | tristate "Test user/kernel boundary protections" |
| 1908 | default n |
| 1909 | depends on m |
| 1910 | help |
| 1911 | This builds the "test_user_copy" module that runs sanity checks |
| 1912 | on the copy_to/from_user infrastructure, making sure basic |
| 1913 | user/kernel boundary testing is working. If it fails to load, |
| 1914 | a regression has been detected in the user/kernel memory boundary |
| 1915 | protections. |
| 1916 | |
| 1917 | If unsure, say N. |
| 1918 | |
Alexei Starovoitov | 64a8946 | 2014-05-08 14:10:52 -0700 | [diff] [blame] | 1919 | config TEST_BPF |
| 1920 | tristate "Test BPF filter functionality" |
| 1921 | default n |
Randy Dunlap | 98920ba | 2014-05-13 09:58:44 -0700 | [diff] [blame] | 1922 | depends on m && NET |
Alexei Starovoitov | 64a8946 | 2014-05-08 14:10:52 -0700 | [diff] [blame] | 1923 | help |
| 1924 | This builds the "test_bpf" module that runs various test vectors |
| 1925 | against the BPF interpreter or BPF JIT compiler depending on the |
| 1926 | current setting. This is in particular useful for BPF JIT compiler |
| 1927 | development, but also to run regression tests against changes in |
Alexei Starovoitov | 3c731eb | 2014-09-26 00:17:07 -0700 | [diff] [blame] | 1928 | the interpreter code. It also enables test stubs for eBPF maps and |
| 1929 | verifier used by user space verifier testsuite. |
Alexei Starovoitov | 64a8946 | 2014-05-08 14:10:52 -0700 | [diff] [blame] | 1930 | |
| 1931 | If unsure, say N. |
| 1932 | |
Kees Cook | 0a8adf5 | 2014-07-14 14:38:12 -0700 | [diff] [blame] | 1933 | config TEST_FIRMWARE |
| 1934 | tristate "Test firmware loading via userspace interface" |
| 1935 | default n |
| 1936 | depends on FW_LOADER |
| 1937 | help |
| 1938 | This builds the "test_firmware" module that creates a userspace |
| 1939 | interface for testing firmware loading. This can be used to |
| 1940 | control the triggering of firmware loading without needing an |
| 1941 | actual firmware-using device. The contents can be rechecked by |
| 1942 | userspace. |
| 1943 | |
| 1944 | If unsure, say N. |
| 1945 | |
David Riley | e704f93 | 2014-06-16 14:58:32 -0700 | [diff] [blame] | 1946 | config TEST_UDELAY |
| 1947 | tristate "udelay test driver" |
| 1948 | default n |
| 1949 | help |
| 1950 | This builds the "udelay_test" module that helps to make sure |
| 1951 | that udelay() is working properly. |
| 1952 | |
| 1953 | If unsure, say N. |
| 1954 | |
Vladimir Murzin | 4a20799 | 2015-04-14 15:48:27 -0700 | [diff] [blame] | 1955 | config MEMTEST |
| 1956 | bool "Memtest" |
| 1957 | depends on HAVE_MEMBLOCK |
| 1958 | ---help--- |
| 1959 | This option adds a kernel parameter 'memtest', which allows memtest |
| 1960 | to be set. |
| 1961 | memtest=0, mean disabled; -- default |
| 1962 | memtest=1, mean do 1 test pattern; |
| 1963 | ... |
Vladimir Murzin | 8d8cfb4 | 2015-04-14 15:48:40 -0700 | [diff] [blame] | 1964 | memtest=17, mean do 17 test patterns. |
Vladimir Murzin | 4a20799 | 2015-04-14 15:48:27 -0700 | [diff] [blame] | 1965 | If you are unsure how to answer this question, answer N. |
| 1966 | |
Ingo Molnar | 2bf9e0a | 2015-08-03 11:42:57 +0200 | [diff] [blame] | 1967 | config TEST_STATIC_KEYS |
| 1968 | tristate "Test static keys" |
Jason Baron | 579e1ac | 2015-07-30 03:59:44 +0000 | [diff] [blame] | 1969 | default n |
| 1970 | depends on m |
| 1971 | help |
Ingo Molnar | 2bf9e0a | 2015-08-03 11:42:57 +0200 | [diff] [blame] | 1972 | Test the static key interfaces. |
Jason Baron | 579e1ac | 2015-07-30 03:59:44 +0000 | [diff] [blame] | 1973 | |
| 1974 | If unsure, say N. |
| 1975 | |
Mathieu Desnoyers | 267c402 | 2007-10-18 23:41:07 -0700 | [diff] [blame] | 1976 | source "samples/Kconfig" |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1977 | |
| 1978 | source "lib/Kconfig.kgdb" |
Pekka Enberg | 0a4af3b | 2009-02-26 21:38:56 +0200 | [diff] [blame] | 1979 | |
Andrey Ryabinin | c6d3085 | 2016-01-20 15:00:55 -0800 | [diff] [blame] | 1980 | source "lib/Kconfig.ubsan" |
| 1981 | |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 1982 | config ARCH_HAS_DEVMEM_IS_ALLOWED |
| 1983 | bool |
| 1984 | |
| 1985 | config STRICT_DEVMEM |
| 1986 | bool "Filter access to /dev/mem" |
| 1987 | depends on MMU |
| 1988 | depends on ARCH_HAS_DEVMEM_IS_ALLOWED |
| 1989 | default y if TILE || PPC |
| 1990 | ---help--- |
| 1991 | If this option is disabled, you allow userspace (root) access to all |
| 1992 | of memory, including kernel and userspace memory. Accidental |
| 1993 | access to this is obviously disastrous, but specific access can |
| 1994 | be used by people debugging the kernel. Note that with PAT support |
| 1995 | enabled, even in this case there are restrictions on /dev/mem |
| 1996 | use due to the cache aliasing requirements. |
| 1997 | |
Dan Williams | 90a545e | 2015-11-23 15:49:03 -0800 | [diff] [blame] | 1998 | If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem |
| 1999 | file only allows userspace access to PCI space and the BIOS code and |
| 2000 | data regions. This is sufficient for dosemu and X and all common |
| 2001 | users of /dev/mem. |
| 2002 | |
| 2003 | If in doubt, say Y. |
| 2004 | |
| 2005 | config IO_STRICT_DEVMEM |
| 2006 | bool "Filter I/O access to /dev/mem" |
| 2007 | depends on STRICT_DEVMEM |
Dan Williams | 90a545e | 2015-11-23 15:49:03 -0800 | [diff] [blame] | 2008 | ---help--- |
| 2009 | If this option is disabled, you allow userspace (root) access to all |
| 2010 | io-memory regardless of whether a driver is actively using that |
| 2011 | range. Accidental access to this is obviously disastrous, but |
| 2012 | specific access can be used by people debugging kernel drivers. |
| 2013 | |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2014 | If this option is switched on, the /dev/mem file only allows |
Dan Williams | 90a545e | 2015-11-23 15:49:03 -0800 | [diff] [blame] | 2015 | userspace access to *idle* io-memory ranges (see /proc/iomem) This |
| 2016 | may break traditional users of /dev/mem (dosemu, legacy X, etc...) |
| 2017 | if the driver using a given range cannot be disabled. |
Dan Williams | 21266be | 2015-11-19 18:19:29 -0800 | [diff] [blame] | 2018 | |
| 2019 | If in doubt, say Y. |