| 1 | # SPDX-License-Identifier: GPL-2.0-only |
| 2 | menu "Kernel hacking" |
| 3 | |
| 4 | menu "printk and dmesg options" |
| 5 | |
| 6 | config PRINTK_TIME |
| 7 | bool "Show timing information on printks" |
| 8 | depends on PRINTK |
| 9 | help |
| 10 | Selecting this option causes time stamps of the printk() |
| 11 | messages to be added to the output of the syslog() system |
| 12 | call and at the console. |
| 13 | |
| 14 | The timestamp is always recorded internally, and exported |
| 15 | to /dev/kmsg. This flag just specifies if the timestamp should |
| 16 | be included, not that the timestamp is recorded. |
| 17 | |
| 18 | The behavior is also controlled by the kernel command line |
| 19 | parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst |
| 20 | |
| 21 | config PRINTK_CALLER |
| 22 | bool "Show caller information on printks" |
| 23 | depends on PRINTK |
| 24 | help |
| 25 | Selecting this option causes printk() to add a caller "thread id" (if |
| 26 | in task context) or a caller "processor id" (if not in task context) |
| 27 | to every message. |
| 28 | |
| 29 | This option is intended for environments where multiple threads |
| 30 | concurrently call printk() for many times, for it is difficult to |
| 31 | interpret without knowing where these lines (or sometimes individual |
| 32 | line which was divided into multiple lines due to race) came from. |
| 33 | |
| 34 | Since toggling after boot makes the code racy, currently there is |
| 35 | no option to enable/disable at the kernel command line parameter or |
| 36 | sysfs interface. |
| 37 | |
| 38 | config STACKTRACE_BUILD_ID |
| 39 | bool "Show build ID information in stacktraces" |
| 40 | depends on PRINTK |
| 41 | help |
| 42 | Selecting this option adds build ID information for symbols in |
| 43 | stacktraces printed with the printk format '%p[SR]b'. |
| 44 | |
| 45 | This option is intended for distros where debuginfo is not easily |
| 46 | accessible but can be downloaded given the build ID of the vmlinux or |
| 47 | kernel module where the function is located. |
| 48 | |
| 49 | config CONSOLE_LOGLEVEL_DEFAULT |
| 50 | int "Default console loglevel (1-15)" |
| 51 | range 1 15 |
| 52 | default "7" |
| 53 | help |
| 54 | Default loglevel to determine what will be printed on the console. |
| 55 | |
| 56 | Setting a default here is equivalent to passing in loglevel=<x> in |
| 57 | the kernel bootargs. loglevel=<x> continues to override whatever |
| 58 | value is specified here as well. |
| 59 | |
| 60 | Note: This does not affect the log level of un-prefixed printk() |
| 61 | usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT |
| 62 | option. |
| 63 | |
| 64 | config CONSOLE_LOGLEVEL_QUIET |
| 65 | int "quiet console loglevel (1-15)" |
| 66 | range 1 15 |
| 67 | default "4" |
| 68 | help |
| 69 | loglevel to use when "quiet" is passed on the kernel commandline. |
| 70 | |
| 71 | When "quiet" is passed on the kernel commandline this loglevel |
| 72 | will be used as the loglevel. IOW passing "quiet" will be the |
| 73 | equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>" |
| 74 | |
| 75 | config MESSAGE_LOGLEVEL_DEFAULT |
| 76 | int "Default message log level (1-7)" |
| 77 | range 1 7 |
| 78 | default "4" |
| 79 | help |
| 80 | Default log level for printk statements with no specified priority. |
| 81 | |
| 82 | This was hard-coded to KERN_WARNING since at least 2.6.10 but folks |
| 83 | that are auditing their logs closely may want to set it to a lower |
| 84 | priority. |
| 85 | |
| 86 | Note: This does not affect what message level gets printed on the console |
| 87 | by default. To change that, use loglevel=<x> in the kernel bootargs, |
| 88 | or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value. |
| 89 | |
| 90 | config BOOT_PRINTK_DELAY |
| 91 | bool "Delay each boot printk message by N milliseconds" |
| 92 | depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
| 93 | help |
| 94 | This build option allows you to read kernel boot messages |
| 95 | by inserting a short delay after each one. The delay is |
| 96 | specified in milliseconds on the kernel command line, |
| 97 | using "boot_delay=N". |
| 98 | |
| 99 | It is likely that you would also need to use "lpj=M" to preset |
| 100 | the "loops per jiffie" value. |
| 101 | See a previous boot log for the "lpj" value to use for your |
| 102 | system, and then set "lpj=M" before setting "boot_delay=N". |
| 103 | NOTE: Using this option may adversely affect SMP systems. |
| 104 | I.e., processors other than the first one may not boot up. |
| 105 | BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect |
| 106 | what it believes to be lockup conditions. |
| 107 | |
| 108 | config DYNAMIC_DEBUG |
| 109 | bool "Enable dynamic printk() support" |
| 110 | default n |
| 111 | depends on PRINTK |
| 112 | depends on (DEBUG_FS || PROC_FS) |
| 113 | select DYNAMIC_DEBUG_CORE |
| 114 | help |
| 115 | |
| 116 | Compiles debug level messages into the kernel, which would not |
| 117 | otherwise be available at runtime. These messages can then be |
| 118 | enabled/disabled based on various levels of scope - per source file, |
| 119 | function, module, format string, and line number. This mechanism |
| 120 | implicitly compiles in all pr_debug() and dev_dbg() calls, which |
| 121 | enlarges the kernel text size by about 2%. |
| 122 | |
| 123 | If a source file is compiled with DEBUG flag set, any |
| 124 | pr_debug() calls in it are enabled by default, but can be |
| 125 | disabled at runtime as below. Note that DEBUG flag is |
| 126 | turned on by many CONFIG_*DEBUG* options. |
| 127 | |
| 128 | Usage: |
| 129 | |
| 130 | Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
| 131 | which is contained in the 'debugfs' filesystem or procfs. |
| 132 | Thus, the debugfs or procfs filesystem must first be mounted before |
| 133 | making use of this feature. |
| 134 | We refer the control file as: <debugfs>/dynamic_debug/control. This |
| 135 | file contains a list of the debug statements that can be enabled. The |
| 136 | format for each line of the file is: |
| 137 | |
| 138 | filename:lineno [module]function flags format |
| 139 | |
| 140 | filename : source file of the debug statement |
| 141 | lineno : line number of the debug statement |
| 142 | module : module that contains the debug statement |
| 143 | function : function that contains the debug statement |
| 144 | flags : '=p' means the line is turned 'on' for printing |
| 145 | format : the format used for the debug statement |
| 146 | |
| 147 | From a live system: |
| 148 | |
| 149 | nullarbor:~ # cat <debugfs>/dynamic_debug/control |
| 150 | # filename:lineno [module]function flags format |
| 151 | fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012" |
| 152 | fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012" |
| 153 | fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012" |
| 154 | |
| 155 | Example usage: |
| 156 | |
| 157 | // enable the message at line 1603 of file svcsock.c |
| 158 | nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
| 159 | <debugfs>/dynamic_debug/control |
| 160 | |
| 161 | // enable all the messages in file svcsock.c |
| 162 | nullarbor:~ # echo -n 'file svcsock.c +p' > |
| 163 | <debugfs>/dynamic_debug/control |
| 164 | |
| 165 | // enable all the messages in the NFS server module |
| 166 | nullarbor:~ # echo -n 'module nfsd +p' > |
| 167 | <debugfs>/dynamic_debug/control |
| 168 | |
| 169 | // enable all 12 messages in the function svc_process() |
| 170 | nullarbor:~ # echo -n 'func svc_process +p' > |
| 171 | <debugfs>/dynamic_debug/control |
| 172 | |
| 173 | // disable all 12 messages in the function svc_process() |
| 174 | nullarbor:~ # echo -n 'func svc_process -p' > |
| 175 | <debugfs>/dynamic_debug/control |
| 176 | |
| 177 | See Documentation/admin-guide/dynamic-debug-howto.rst for additional |
| 178 | information. |
| 179 | |
| 180 | config DYNAMIC_DEBUG_CORE |
| 181 | bool "Enable core function of dynamic debug support" |
| 182 | depends on PRINTK |
| 183 | depends on (DEBUG_FS || PROC_FS) |
| 184 | help |
| 185 | Enable core functional support of dynamic debug. It is useful |
| 186 | when you want to tie dynamic debug to your kernel modules with |
| 187 | DYNAMIC_DEBUG_MODULE defined for each of them, especially for |
| 188 | the case of embedded system where the kernel image size is |
| 189 | sensitive for people. |
| 190 | |
| 191 | config SYMBOLIC_ERRNAME |
| 192 | bool "Support symbolic error names in printf" |
| 193 | default y if PRINTK |
| 194 | help |
| 195 | If you say Y here, the kernel's printf implementation will |
| 196 | be able to print symbolic error names such as ENOSPC instead |
| 197 | of the number 28. It makes the kernel image slightly larger |
| 198 | (about 3KB), but can make the kernel logs easier to read. |
| 199 | |
| 200 | config DEBUG_BUGVERBOSE |
| 201 | bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT |
| 202 | depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) |
| 203 | default y |
| 204 | help |
| 205 | Say Y here to make BUG() panics output the file name and line number |
| 206 | of the BUG call as well as the EIP and oops trace. This aids |
| 207 | debugging but costs about 70-100K of memory. |
| 208 | |
| 209 | endmenu # "printk and dmesg options" |
| 210 | |
| 211 | config DEBUG_KERNEL |
| 212 | bool "Kernel debugging" |
| 213 | help |
| 214 | Say Y here if you are developing drivers or trying to debug and |
| 215 | identify kernel problems. |
| 216 | |
| 217 | config DEBUG_MISC |
| 218 | bool "Miscellaneous debug code" |
| 219 | default DEBUG_KERNEL |
| 220 | depends on DEBUG_KERNEL |
| 221 | help |
| 222 | Say Y here if you need to enable miscellaneous debug code that should |
| 223 | be under a more specific debug option but isn't. |
| 224 | |
| 225 | menu "Compile-time checks and compiler options" |
| 226 | |
| 227 | config DEBUG_INFO |
| 228 | bool |
| 229 | help |
| 230 | A kernel debug info option other than "None" has been selected |
| 231 | in the "Debug information" choice below, indicating that debug |
| 232 | information will be generated for build targets. |
| 233 | |
| 234 | # Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which |
| 235 | # some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215 |
| 236 | config AS_HAS_NON_CONST_LEB128 |
| 237 | def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:) |
| 238 | |
| 239 | choice |
| 240 | prompt "Debug information" |
| 241 | depends on DEBUG_KERNEL |
| 242 | help |
| 243 | Selecting something other than "None" results in a kernel image |
| 244 | that will include debugging info resulting in a larger kernel image. |
| 245 | This adds debug symbols to the kernel and modules (gcc -g), and |
| 246 | is needed if you intend to use kernel crashdump or binary object |
| 247 | tools like crash, kgdb, LKCD, gdb, etc on the kernel. |
| 248 | |
| 249 | Choose which version of DWARF debug info to emit. If unsure, |
| 250 | select "Toolchain default". |
| 251 | |
| 252 | config DEBUG_INFO_NONE |
| 253 | bool "Disable debug information" |
| 254 | help |
| 255 | Do not build the kernel with debugging information, which will |
| 256 | result in a faster and smaller build. |
| 257 | |
| 258 | config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT |
| 259 | bool "Rely on the toolchain's implicit default DWARF version" |
| 260 | select DEBUG_INFO |
| 261 | depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128) |
| 262 | help |
| 263 | The implicit default version of DWARF debug info produced by a |
| 264 | toolchain changes over time. |
| 265 | |
| 266 | This can break consumers of the debug info that haven't upgraded to |
| 267 | support newer revisions, and prevent testing newer versions, but |
| 268 | those should be less common scenarios. |
| 269 | |
| 270 | config DEBUG_INFO_DWARF4 |
| 271 | bool "Generate DWARF Version 4 debuginfo" |
| 272 | select DEBUG_INFO |
| 273 | depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502) |
| 274 | help |
| 275 | Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2 |
| 276 | if using clang without clang's integrated assembler, and gdb 7.0+. |
| 277 | |
| 278 | If you have consumers of DWARF debug info that are not ready for |
| 279 | newer revisions of DWARF, you may wish to choose this or have your |
| 280 | config select this. |
| 281 | |
| 282 | config DEBUG_INFO_DWARF5 |
| 283 | bool "Generate DWARF Version 5 debuginfo" |
| 284 | select DEBUG_INFO |
| 285 | depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128) |
| 286 | help |
| 287 | Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc |
| 288 | 5.0+ accepts the -gdwarf-5 flag but only had partial support for some |
| 289 | draft features until 7.0), and gdb 8.0+. |
| 290 | |
| 291 | Changes to the structure of debug info in Version 5 allow for around |
| 292 | 15-18% savings in resulting image and debug info section sizes as |
| 293 | compared to DWARF Version 4. DWARF Version 5 standardizes previous |
| 294 | extensions such as accelerators for symbol indexing and the format |
| 295 | for fission (.dwo/.dwp) files. Users may not want to select this |
| 296 | config if they rely on tooling that has not yet been updated to |
| 297 | support DWARF Version 5. |
| 298 | |
| 299 | endchoice # "Debug information" |
| 300 | |
| 301 | if DEBUG_INFO |
| 302 | |
| 303 | config DEBUG_INFO_REDUCED |
| 304 | bool "Reduce debugging information" |
| 305 | help |
| 306 | If you say Y here gcc is instructed to generate less debugging |
| 307 | information for structure types. This means that tools that |
| 308 | need full debugging information (like kgdb or systemtap) won't |
| 309 | be happy. But if you merely need debugging information to |
| 310 | resolve line numbers there is no loss. Advantage is that |
| 311 | build directory object sizes shrink dramatically over a full |
| 312 | DEBUG_INFO build and compile times are reduced too. |
| 313 | Only works with newer gcc versions. |
| 314 | |
| 315 | choice |
| 316 | prompt "Compressed Debug information" |
| 317 | help |
| 318 | Compress the resulting debug info. Results in smaller debug info sections, |
| 319 | but requires that consumers are able to decompress the results. |
| 320 | |
| 321 | If unsure, choose DEBUG_INFO_COMPRESSED_NONE. |
| 322 | |
| 323 | config DEBUG_INFO_COMPRESSED_NONE |
| 324 | bool "Don't compress debug information" |
| 325 | help |
| 326 | Don't compress debug info sections. |
| 327 | |
| 328 | config DEBUG_INFO_COMPRESSED_ZLIB |
| 329 | bool "Compress debugging information with zlib" |
| 330 | depends on $(cc-option,-gz=zlib) |
| 331 | depends on $(ld-option,--compress-debug-sections=zlib) |
| 332 | help |
| 333 | Compress the debug information using zlib. Requires GCC 5.0+ or Clang |
| 334 | 5.0+, binutils 2.26+, and zlib. |
| 335 | |
| 336 | Users of dpkg-deb via scripts/package/builddeb may find an increase in |
| 337 | size of their debug .deb packages with this config set, due to the |
| 338 | debug info being compressed with zlib, then the object files being |
| 339 | recompressed with a different compression scheme. But this is still |
| 340 | preferable to setting $KDEB_COMPRESS to "none" which would be even |
| 341 | larger. |
| 342 | |
| 343 | config DEBUG_INFO_COMPRESSED_ZSTD |
| 344 | bool "Compress debugging information with zstd" |
| 345 | depends on $(cc-option,-gz=zstd) |
| 346 | depends on $(ld-option,--compress-debug-sections=zstd) |
| 347 | help |
| 348 | Compress the debug information using zstd. This may provide better |
| 349 | compression than zlib, for about the same time costs, but requires newer |
| 350 | toolchain support. Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and |
| 351 | zstd. |
| 352 | |
| 353 | endchoice # "Compressed Debug information" |
| 354 | |
| 355 | config DEBUG_INFO_SPLIT |
| 356 | bool "Produce split debuginfo in .dwo files" |
| 357 | depends on $(cc-option,-gsplit-dwarf) |
| 358 | help |
| 359 | Generate debug info into separate .dwo files. This significantly |
| 360 | reduces the build directory size for builds with DEBUG_INFO, |
| 361 | because it stores the information only once on disk in .dwo |
| 362 | files instead of multiple times in object files and executables. |
| 363 | In addition the debug information is also compressed. |
| 364 | |
| 365 | Requires recent gcc (4.7+) and recent gdb/binutils. |
| 366 | Any tool that packages or reads debug information would need |
| 367 | to know about the .dwo files and include them. |
| 368 | Incompatible with older versions of ccache. |
| 369 | |
| 370 | config DEBUG_INFO_BTF |
| 371 | bool "Generate BTF typeinfo" |
| 372 | depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED |
| 373 | depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST |
| 374 | depends on BPF_SYSCALL |
| 375 | depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121 |
| 376 | help |
| 377 | Generate deduplicated BTF type information from DWARF debug info. |
| 378 | Turning this on expects presence of pahole tool, which will convert |
| 379 | DWARF type info into equivalent deduplicated BTF type info. |
| 380 | |
| 381 | config PAHOLE_HAS_SPLIT_BTF |
| 382 | def_bool PAHOLE_VERSION >= 119 |
| 383 | |
| 384 | config PAHOLE_HAS_BTF_TAG |
| 385 | def_bool PAHOLE_VERSION >= 123 |
| 386 | depends on CC_IS_CLANG |
| 387 | help |
| 388 | Decide whether pahole emits btf_tag attributes (btf_type_tag and |
| 389 | btf_decl_tag) or not. Currently only clang compiler implements |
| 390 | these attributes, so make the config depend on CC_IS_CLANG. |
| 391 | |
| 392 | config DEBUG_INFO_BTF_MODULES |
| 393 | def_bool y |
| 394 | depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF |
| 395 | help |
| 396 | Generate compact split BTF type information for kernel modules. |
| 397 | |
| 398 | config MODULE_ALLOW_BTF_MISMATCH |
| 399 | bool "Allow loading modules with non-matching BTF type info" |
| 400 | depends on DEBUG_INFO_BTF_MODULES |
| 401 | help |
| 402 | For modules whose split BTF does not match vmlinux, load without |
| 403 | BTF rather than refusing to load. The default behavior with |
| 404 | module BTF enabled is to reject modules with such mismatches; |
| 405 | this option will still load module BTF where possible but ignore |
| 406 | it when a mismatch is found. |
| 407 | |
| 408 | config GDB_SCRIPTS |
| 409 | bool "Provide GDB scripts for kernel debugging" |
| 410 | help |
| 411 | This creates the required links to GDB helper scripts in the |
| 412 | build directory. If you load vmlinux into gdb, the helper |
| 413 | scripts will be automatically imported by gdb as well, and |
| 414 | additional functions are available to analyze a Linux kernel |
| 415 | instance. See Documentation/dev-tools/gdb-kernel-debugging.rst |
| 416 | for further details. |
| 417 | |
| 418 | endif # DEBUG_INFO |
| 419 | |
| 420 | config FRAME_WARN |
| 421 | int "Warn for stack frames larger than" |
| 422 | range 0 8192 |
| 423 | default 0 if KMSAN |
| 424 | default 2048 if GCC_PLUGIN_LATENT_ENTROPY |
| 425 | default 2048 if PARISC |
| 426 | default 1536 if (!64BIT && XTENSA) |
| 427 | default 1280 if KASAN && !64BIT |
| 428 | default 1024 if !64BIT |
| 429 | default 2048 if 64BIT |
| 430 | help |
| 431 | Tell the compiler to warn at build time for stack frames larger than this. |
| 432 | Setting this too low will cause a lot of warnings. |
| 433 | Setting it to 0 disables the warning. |
| 434 | |
| 435 | config STRIP_ASM_SYMS |
| 436 | bool "Strip assembler-generated symbols during link" |
| 437 | default n |
| 438 | help |
| 439 | Strip internal assembler-generated symbols during a link (symbols |
| 440 | that look like '.Lxxx') so they don't pollute the output of |
| 441 | get_wchan() and suchlike. |
| 442 | |
| 443 | config READABLE_ASM |
| 444 | bool "Generate readable assembler code" |
| 445 | depends on DEBUG_KERNEL |
| 446 | depends on CC_IS_GCC |
| 447 | help |
| 448 | Disable some compiler optimizations that tend to generate human unreadable |
| 449 | assembler output. This may make the kernel slightly slower, but it helps |
| 450 | to keep kernel developers who have to stare a lot at assembler listings |
| 451 | sane. |
| 452 | |
| 453 | config HEADERS_INSTALL |
| 454 | bool "Install uapi headers to usr/include" |
| 455 | depends on !UML |
| 456 | help |
| 457 | This option will install uapi headers (headers exported to user-space) |
| 458 | into the usr/include directory for use during the kernel build. |
| 459 | This is unneeded for building the kernel itself, but needed for some |
| 460 | user-space program samples. It is also needed by some features such |
| 461 | as uapi header sanity checks. |
| 462 | |
| 463 | config DEBUG_SECTION_MISMATCH |
| 464 | bool "Enable full Section mismatch analysis" |
| 465 | depends on CC_IS_GCC |
| 466 | help |
| 467 | The section mismatch analysis checks if there are illegal |
| 468 | references from one section to another section. |
| 469 | During linktime or runtime, some sections are dropped; |
| 470 | any use of code/data previously in these sections would |
| 471 | most likely result in an oops. |
| 472 | In the code, functions and variables are annotated with |
| 473 | __init,, etc. (see the full list in include/linux/init.h), |
| 474 | which results in the code/data being placed in specific sections. |
| 475 | The section mismatch analysis is always performed after a full |
| 476 | kernel build, and enabling this option causes the following |
| 477 | additional step to occur: |
| 478 | - Add the option -fno-inline-functions-called-once to gcc commands. |
| 479 | When inlining a function annotated with __init in a non-init |
| 480 | function, we would lose the section information and thus |
| 481 | the analysis would not catch the illegal reference. |
| 482 | This option tells gcc to inline less (but it does result in |
| 483 | a larger kernel). |
| 484 | |
| 485 | config SECTION_MISMATCH_WARN_ONLY |
| 486 | bool "Make section mismatch errors non-fatal" |
| 487 | default y |
| 488 | help |
| 489 | If you say N here, the build process will fail if there are any |
| 490 | section mismatch, instead of just throwing warnings. |
| 491 | |
| 492 | If unsure, say Y. |
| 493 | |
| 494 | config DEBUG_FORCE_FUNCTION_ALIGN_64B |
| 495 | bool "Force all function address 64B aligned" |
| 496 | depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC) |
| 497 | select FUNCTION_ALIGNMENT_64B |
| 498 | help |
| 499 | There are cases that a commit from one domain changes the function |
| 500 | address alignment of other domains, and cause magic performance |
| 501 | bump (regression or improvement). Enable this option will help to |
| 502 | verify if the bump is caused by function alignment changes, while |
| 503 | it will slightly increase the kernel size and affect icache usage. |
| 504 | |
| 505 | It is mainly for debug and performance tuning use. |
| 506 | |
| 507 | # |
| 508 | # Select this config option from the architecture Kconfig, if it |
| 509 | # is preferred to always offer frame pointers as a config |
| 510 | # option on the architecture (regardless of KERNEL_DEBUG): |
| 511 | # |
| 512 | config ARCH_WANT_FRAME_POINTERS |
| 513 | bool |
| 514 | |
| 515 | config FRAME_POINTER |
| 516 | bool "Compile the kernel with frame pointers" |
| 517 | depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS |
| 518 | default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS |
| 519 | help |
| 520 | If you say Y here the resulting kernel image will be slightly |
| 521 | larger and slower, but it gives very useful debugging information |
| 522 | in case of kernel bugs. (precise oopses/stacktraces/warnings) |
| 523 | |
| 524 | config OBJTOOL |
| 525 | bool |
| 526 | |
| 527 | config STACK_VALIDATION |
| 528 | bool "Compile-time stack metadata validation" |
| 529 | depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER |
| 530 | select OBJTOOL |
| 531 | default n |
| 532 | help |
| 533 | Validate frame pointer rules at compile-time. This helps ensure that |
| 534 | runtime stack traces are more reliable. |
| 535 | |
| 536 | For more information, see |
| 537 | tools/objtool/Documentation/objtool.txt. |
| 538 | |
| 539 | config NOINSTR_VALIDATION |
| 540 | bool |
| 541 | depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY |
| 542 | select OBJTOOL |
| 543 | default y |
| 544 | |
| 545 | config VMLINUX_MAP |
| 546 | bool "Generate vmlinux.map file when linking" |
| 547 | depends on EXPERT |
| 548 | help |
| 549 | Selecting this option will pass "-Map=vmlinux.map" to ld |
| 550 | when linking vmlinux. That file can be useful for verifying |
| 551 | and debugging magic section games, and for seeing which |
| 552 | pieces of code get eliminated with |
| 553 | CONFIG_LD_DEAD_CODE_DATA_ELIMINATION. |
| 554 | |
| 555 | config DEBUG_FORCE_WEAK_PER_CPU |
| 556 | bool "Force weak per-cpu definitions" |
| 557 | depends on DEBUG_KERNEL |
| 558 | help |
| 559 | s390 and alpha require percpu variables in modules to be |
| 560 | defined weak to work around addressing range issue which |
| 561 | puts the following two restrictions on percpu variable |
| 562 | definitions. |
| 563 | |
| 564 | 1. percpu symbols must be unique whether static or not |
| 565 | 2. percpu variables can't be defined inside a function |
| 566 | |
| 567 | To ensure that generic code follows the above rules, this |
| 568 | option forces all percpu variables to be defined as weak. |
| 569 | |
| 570 | endmenu # "Compiler options" |
| 571 | |
| 572 | menu "Generic Kernel Debugging Instruments" |
| 573 | |
| 574 | config MAGIC_SYSRQ |
| 575 | bool "Magic SysRq key" |
| 576 | depends on !UML |
| 577 | help |
| 578 | If you say Y here, you will have some control over the system even |
| 579 | if the system crashes for example during kernel debugging (e.g., you |
| 580 | will be able to flush the buffer cache to disk, reboot the system |
| 581 | immediately or dump some status information). This is accomplished |
| 582 | by pressing various keys while holding SysRq (Alt+PrintScreen). It |
| 583 | also works on a serial console (on PC hardware at least), if you |
| 584 | send a BREAK and then within 5 seconds a command keypress. The |
| 585 | keys are documented in <file:Documentation/admin-guide/sysrq.rst>. |
| 586 | Don't say Y unless you really know what this hack does. |
| 587 | |
| 588 | config MAGIC_SYSRQ_DEFAULT_ENABLE |
| 589 | hex "Enable magic SysRq key functions by default" |
| 590 | depends on MAGIC_SYSRQ |
| 591 | default 0x1 |
| 592 | help |
| 593 | Specifies which SysRq key functions are enabled by default. |
| 594 | This may be set to 1 or 0 to enable or disable them all, or |
| 595 | to a bitmask as described in Documentation/admin-guide/sysrq.rst. |
| 596 | |
| 597 | config MAGIC_SYSRQ_SERIAL |
| 598 | bool "Enable magic SysRq key over serial" |
| 599 | depends on MAGIC_SYSRQ |
| 600 | default y |
| 601 | help |
| 602 | Many embedded boards have a disconnected TTL level serial which can |
| 603 | generate some garbage that can lead to spurious false sysrq detects. |
| 604 | This option allows you to decide whether you want to enable the |
| 605 | magic SysRq key. |
| 606 | |
| 607 | config MAGIC_SYSRQ_SERIAL_SEQUENCE |
| 608 | string "Char sequence that enables magic SysRq over serial" |
| 609 | depends on MAGIC_SYSRQ_SERIAL |
| 610 | default "" |
| 611 | help |
| 612 | Specifies a sequence of characters that can follow BREAK to enable |
| 613 | SysRq on a serial console. |
| 614 | |
| 615 | If unsure, leave an empty string and the option will not be enabled. |
| 616 | |
| 617 | config DEBUG_FS |
| 618 | bool "Debug Filesystem" |
| 619 | help |
| 620 | debugfs is a virtual file system that kernel developers use to put |
| 621 | debugging files into. Enable this option to be able to read and |
| 622 | write to these files. |
| 623 | |
| 624 | For detailed documentation on the debugfs API, see |
| 625 | Documentation/filesystems/. |
| 626 | |
| 627 | If unsure, say N. |
| 628 | |
| 629 | choice |
| 630 | prompt "Debugfs default access" |
| 631 | depends on DEBUG_FS |
| 632 | default DEBUG_FS_ALLOW_ALL |
| 633 | help |
| 634 | This selects the default access restrictions for debugfs. |
| 635 | It can be overridden with kernel command line option |
| 636 | debugfs=[on,no-mount,off]. The restrictions apply for API access |
| 637 | and filesystem registration. |
| 638 | |
| 639 | config DEBUG_FS_ALLOW_ALL |
| 640 | bool "Access normal" |
| 641 | help |
| 642 | No restrictions apply. Both API and filesystem registration |
| 643 | is on. This is the normal default operation. |
| 644 | |
| 645 | config DEBUG_FS_DISALLOW_MOUNT |
| 646 | bool "Do not register debugfs as filesystem" |
| 647 | help |
| 648 | The API is open but filesystem is not loaded. Clients can still do |
| 649 | their work and read with debug tools that do not need |
| 650 | debugfs filesystem. |
| 651 | |
| 652 | config DEBUG_FS_ALLOW_NONE |
| 653 | bool "No access" |
| 654 | help |
| 655 | Access is off. Clients get -PERM when trying to create nodes in |
| 656 | debugfs tree and debugfs is not registered as a filesystem. |
| 657 | Client can then back-off or continue without debugfs access. |
| 658 | |
| 659 | endchoice |
| 660 | |
| 661 | source "lib/Kconfig.kgdb" |
| 662 | source "lib/Kconfig.ubsan" |
| 663 | source "lib/Kconfig.kcsan" |
| 664 | |
| 665 | endmenu |
| 666 | |
| 667 | menu "Networking Debugging" |
| 668 | |
| 669 | source "net/Kconfig.debug" |
| 670 | |
| 671 | endmenu # "Networking Debugging" |
| 672 | |
| 673 | menu "Memory Debugging" |
| 674 | |
| 675 | source "mm/Kconfig.debug" |
| 676 | |
| 677 | config DEBUG_OBJECTS |
| 678 | bool "Debug object operations" |
| 679 | depends on DEBUG_KERNEL |
| 680 | help |
| 681 | If you say Y here, additional code will be inserted into the |
| 682 | kernel to track the life time of various objects and validate |
| 683 | the operations on those objects. |
| 684 | |
| 685 | config DEBUG_OBJECTS_SELFTEST |
| 686 | bool "Debug objects selftest" |
| 687 | depends on DEBUG_OBJECTS |
| 688 | help |
| 689 | This enables the selftest of the object debug code. |
| 690 | |
| 691 | config DEBUG_OBJECTS_FREE |
| 692 | bool "Debug objects in freed memory" |
| 693 | depends on DEBUG_OBJECTS |
| 694 | help |
| 695 | This enables checks whether a k/v free operation frees an area |
| 696 | which contains an object which has not been deactivated |
| 697 | properly. This can make kmalloc/kfree-intensive workloads |
| 698 | much slower. |
| 699 | |
| 700 | config DEBUG_OBJECTS_TIMERS |
| 701 | bool "Debug timer objects" |
| 702 | depends on DEBUG_OBJECTS |
| 703 | help |
| 704 | If you say Y here, additional code will be inserted into the |
| 705 | timer routines to track the life time of timer objects and |
| 706 | validate the timer operations. |
| 707 | |
| 708 | config DEBUG_OBJECTS_WORK |
| 709 | bool "Debug work objects" |
| 710 | depends on DEBUG_OBJECTS |
| 711 | help |
| 712 | If you say Y here, additional code will be inserted into the |
| 713 | work queue routines to track the life time of work objects and |
| 714 | validate the work operations. |
| 715 | |
| 716 | config DEBUG_OBJECTS_RCU_HEAD |
| 717 | bool "Debug RCU callbacks objects" |
| 718 | depends on DEBUG_OBJECTS |
| 719 | help |
| 720 | Enable this to turn on debugging of RCU list heads (call_rcu() usage). |
| 721 | |
| 722 | config DEBUG_OBJECTS_PERCPU_COUNTER |
| 723 | bool "Debug percpu counter objects" |
| 724 | depends on DEBUG_OBJECTS |
| 725 | help |
| 726 | If you say Y here, additional code will be inserted into the |
| 727 | percpu counter routines to track the life time of percpu counter |
| 728 | objects and validate the percpu counter operations. |
| 729 | |
| 730 | config DEBUG_OBJECTS_ENABLE_DEFAULT |
| 731 | int "debug_objects bootup default value (0-1)" |
| 732 | range 0 1 |
| 733 | default "1" |
| 734 | depends on DEBUG_OBJECTS |
| 735 | help |
| 736 | Debug objects boot parameter default value |
| 737 | |
| 738 | config SHRINKER_DEBUG |
| 739 | bool "Enable shrinker debugging support" |
| 740 | depends on DEBUG_FS |
| 741 | help |
| 742 | Say Y to enable the shrinker debugfs interface which provides |
| 743 | visibility into the kernel memory shrinkers subsystem. |
| 744 | Disable it to avoid an extra memory footprint. |
| 745 | |
| 746 | config HAVE_DEBUG_KMEMLEAK |
| 747 | bool |
| 748 | |
| 749 | config DEBUG_KMEMLEAK |
| 750 | bool "Kernel memory leak detector" |
| 751 | depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK |
| 752 | select DEBUG_FS |
| 753 | select STACKTRACE if STACKTRACE_SUPPORT |
| 754 | select KALLSYMS |
| 755 | select CRC32 |
| 756 | select STACKDEPOT |
| 757 | help |
| 758 | Say Y here if you want to enable the memory leak |
| 759 | detector. The memory allocation/freeing is traced in a way |
| 760 | similar to the Boehm's conservative garbage collector, the |
| 761 | difference being that the orphan objects are not freed but |
| 762 | only shown in /sys/kernel/debug/kmemleak. Enabling this |
| 763 | feature will introduce an overhead to memory |
| 764 | allocations. See Documentation/dev-tools/kmemleak.rst for more |
| 765 | details. |
| 766 | |
| 767 | Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
| 768 | of finding leaks due to the slab objects poisoning. |
| 769 | |
| 770 | In order to access the kmemleak file, debugfs needs to be |
| 771 | mounted (usually at /sys/kernel/debug). |
| 772 | |
| 773 | config DEBUG_KMEMLEAK_MEM_POOL_SIZE |
| 774 | int "Kmemleak memory pool size" |
| 775 | depends on DEBUG_KMEMLEAK |
| 776 | range 200 1000000 |
| 777 | default 16000 |
| 778 | help |
| 779 | Kmemleak must track all the memory allocations to avoid |
| 780 | reporting false positives. Since memory may be allocated or |
| 781 | freed before kmemleak is fully initialised, use a static pool |
| 782 | of metadata objects to track such callbacks. After kmemleak is |
| 783 | fully initialised, this memory pool acts as an emergency one |
| 784 | if slab allocations fail. |
| 785 | |
| 786 | config DEBUG_KMEMLEAK_TEST |
| 787 | tristate "Simple test for the kernel memory leak detector" |
| 788 | depends on DEBUG_KMEMLEAK && m |
| 789 | help |
| 790 | This option enables a module that explicitly leaks memory. |
| 791 | |
| 792 | If unsure, say N. |
| 793 | |
| 794 | config DEBUG_KMEMLEAK_DEFAULT_OFF |
| 795 | bool "Default kmemleak to off" |
| 796 | depends on DEBUG_KMEMLEAK |
| 797 | help |
| 798 | Say Y here to disable kmemleak by default. It can then be enabled |
| 799 | on the command line via kmemleak=on. |
| 800 | |
| 801 | config DEBUG_KMEMLEAK_AUTO_SCAN |
| 802 | bool "Enable kmemleak auto scan thread on boot up" |
| 803 | default y |
| 804 | depends on DEBUG_KMEMLEAK |
| 805 | help |
| 806 | Depending on the cpu, kmemleak scan may be cpu intensive and can |
| 807 | stall user tasks at times. This option enables/disables automatic |
| 808 | kmemleak scan at boot up. |
| 809 | |
| 810 | Say N here to disable kmemleak auto scan thread to stop automatic |
| 811 | scanning. Disabling this option disables automatic reporting of |
| 812 | memory leaks. |
| 813 | |
| 814 | If unsure, say Y. |
| 815 | |
| 816 | config DEBUG_STACK_USAGE |
| 817 | bool "Stack utilization instrumentation" |
| 818 | depends on DEBUG_KERNEL && !IA64 |
| 819 | help |
| 820 | Enables the display of the minimum amount of free stack which each |
| 821 | task has ever had available in the sysrq-T and sysrq-P debug output. |
| 822 | |
| 823 | This option will slow down process creation somewhat. |
| 824 | |
| 825 | config SCHED_STACK_END_CHECK |
| 826 | bool "Detect stack corruption on calls to schedule()" |
| 827 | depends on DEBUG_KERNEL |
| 828 | default n |
| 829 | help |
| 830 | This option checks for a stack overrun on calls to schedule(). |
| 831 | If the stack end location is found to be over written always panic as |
| 832 | the content of the corrupted region can no longer be trusted. |
| 833 | This is to ensure no erroneous behaviour occurs which could result in |
| 834 | data corruption or a sporadic crash at a later stage once the region |
| 835 | is examined. The runtime overhead introduced is minimal. |
| 836 | |
| 837 | config ARCH_HAS_DEBUG_VM_PGTABLE |
| 838 | bool |
| 839 | help |
| 840 | An architecture should select this when it can successfully |
| 841 | build and run DEBUG_VM_PGTABLE. |
| 842 | |
| 843 | config DEBUG_VM_IRQSOFF |
| 844 | def_bool DEBUG_VM && !PREEMPT_RT |
| 845 | |
| 846 | config DEBUG_VM |
| 847 | bool "Debug VM" |
| 848 | depends on DEBUG_KERNEL |
| 849 | help |
| 850 | Enable this to turn on extended checks in the virtual-memory system |
| 851 | that may impact performance. |
| 852 | |
| 853 | If unsure, say N. |
| 854 | |
| 855 | config DEBUG_VM_MAPLE_TREE |
| 856 | bool "Debug VM maple trees" |
| 857 | depends on DEBUG_VM |
| 858 | select DEBUG_MAPLE_TREE |
| 859 | help |
| 860 | Enable VM maple tree debugging information and extra validations. |
| 861 | |
| 862 | If unsure, say N. |
| 863 | |
| 864 | config DEBUG_VM_RB |
| 865 | bool "Debug VM red-black trees" |
| 866 | depends on DEBUG_VM |
| 867 | help |
| 868 | Enable VM red-black tree debugging information and extra validations. |
| 869 | |
| 870 | If unsure, say N. |
| 871 | |
| 872 | config DEBUG_VM_PGFLAGS |
| 873 | bool "Debug page-flags operations" |
| 874 | depends on DEBUG_VM |
| 875 | help |
| 876 | Enables extra validation on page flags operations. |
| 877 | |
| 878 | If unsure, say N. |
| 879 | |
| 880 | config DEBUG_VM_PGTABLE |
| 881 | bool "Debug arch page table for semantics compliance" |
| 882 | depends on MMU |
| 883 | depends on ARCH_HAS_DEBUG_VM_PGTABLE |
| 884 | default y if DEBUG_VM |
| 885 | help |
| 886 | This option provides a debug method which can be used to test |
| 887 | architecture page table helper functions on various platforms in |
| 888 | verifying if they comply with expected generic MM semantics. This |
| 889 | will help architecture code in making sure that any changes or |
| 890 | new additions of these helpers still conform to expected |
| 891 | semantics of the generic MM. Platforms will have to opt in for |
| 892 | this through ARCH_HAS_DEBUG_VM_PGTABLE. |
| 893 | |
| 894 | If unsure, say N. |
| 895 | |
| 896 | config ARCH_HAS_DEBUG_VIRTUAL |
| 897 | bool |
| 898 | |
| 899 | config DEBUG_VIRTUAL |
| 900 | bool "Debug VM translations" |
| 901 | depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL |
| 902 | help |
| 903 | Enable some costly sanity checks in virtual to page code. This can |
| 904 | catch mistakes with virt_to_page() and friends. |
| 905 | |
| 906 | If unsure, say N. |
| 907 | |
| 908 | config DEBUG_NOMMU_REGIONS |
| 909 | bool "Debug the global anon/private NOMMU mapping region tree" |
| 910 | depends on DEBUG_KERNEL && !MMU |
| 911 | help |
| 912 | This option causes the global tree of anonymous and private mapping |
| 913 | regions to be regularly checked for invalid topology. |
| 914 | |
| 915 | config DEBUG_MEMORY_INIT |
| 916 | bool "Debug memory initialisation" if EXPERT |
| 917 | default !EXPERT |
| 918 | help |
| 919 | Enable this for additional checks during memory initialisation. |
| 920 | The sanity checks verify aspects of the VM such as the memory model |
| 921 | and other information provided by the architecture. Verbose |
| 922 | information will be printed at KERN_DEBUG loglevel depending |
| 923 | on the mminit_loglevel= command-line option. |
| 924 | |
| 925 | If unsure, say Y |
| 926 | |
| 927 | config MEMORY_NOTIFIER_ERROR_INJECT |
| 928 | tristate "Memory hotplug notifier error injection module" |
| 929 | depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION |
| 930 | help |
| 931 | This option provides the ability to inject artificial errors to |
| 932 | memory hotplug notifier chain callbacks. It is controlled through |
| 933 | debugfs interface under /sys/kernel/debug/notifier-error-inject/memory |
| 934 | |
| 935 | If the notifier call chain should be failed with some events |
| 936 | notified, write the error code to "actions/<notifier event>/error". |
| 937 | |
| 938 | Example: Inject memory hotplug offline error (-12 == -ENOMEM) |
| 939 | |
| 940 | # cd /sys/kernel/debug/notifier-error-inject/memory |
| 941 | # echo -12 > actions/MEM_GOING_OFFLINE/error |
| 942 | # echo offline > /sys/devices/system/memory/memoryXXX/state |
| 943 | bash: echo: write error: Cannot allocate memory |
| 944 | |
| 945 | To compile this code as a module, choose M here: the module will |
| 946 | be called memory-notifier-error-inject. |
| 947 | |
| 948 | If unsure, say N. |
| 949 | |
| 950 | config DEBUG_PER_CPU_MAPS |
| 951 | bool "Debug access to per_cpu maps" |
| 952 | depends on DEBUG_KERNEL |
| 953 | depends on SMP |
| 954 | help |
| 955 | Say Y to verify that the per_cpu map being accessed has |
| 956 | been set up. This adds a fair amount of code to kernel memory |
| 957 | and decreases performance. |
| 958 | |
| 959 | Say N if unsure. |
| 960 | |
| 961 | config DEBUG_KMAP_LOCAL |
| 962 | bool "Debug kmap_local temporary mappings" |
| 963 | depends on DEBUG_KERNEL && KMAP_LOCAL |
| 964 | help |
| 965 | This option enables additional error checking for the kmap_local |
| 966 | infrastructure. Disable for production use. |
| 967 | |
| 968 | config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
| 969 | bool |
| 970 | |
| 971 | config DEBUG_KMAP_LOCAL_FORCE_MAP |
| 972 | bool "Enforce kmap_local temporary mappings" |
| 973 | depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
| 974 | select KMAP_LOCAL |
| 975 | select DEBUG_KMAP_LOCAL |
| 976 | help |
| 977 | This option enforces temporary mappings through the kmap_local |
| 978 | mechanism for non-highmem pages and on non-highmem systems. |
| 979 | Disable this for production systems! |
| 980 | |
| 981 | config DEBUG_HIGHMEM |
| 982 | bool "Highmem debugging" |
| 983 | depends on DEBUG_KERNEL && HIGHMEM |
| 984 | select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP |
| 985 | select DEBUG_KMAP_LOCAL |
| 986 | help |
| 987 | This option enables additional error checking for high memory |
| 988 | systems. Disable for production systems. |
| 989 | |
| 990 | config HAVE_DEBUG_STACKOVERFLOW |
| 991 | bool |
| 992 | |
| 993 | config DEBUG_STACKOVERFLOW |
| 994 | bool "Check for stack overflows" |
| 995 | depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW |
| 996 | help |
| 997 | Say Y here if you want to check for overflows of kernel, IRQ |
| 998 | and exception stacks (if your architecture uses them). This |
| 999 | option will show detailed messages if free stack space drops |
| 1000 | below a certain limit. |
| 1001 | |
| 1002 | These kinds of bugs usually occur when call-chains in the |
| 1003 | kernel get too deep, especially when interrupts are |
| 1004 | involved. |
| 1005 | |
| 1006 | Use this in cases where you see apparently random memory |
| 1007 | corruption, especially if it appears in 'struct thread_info' |
| 1008 | |
| 1009 | If in doubt, say "N". |
| 1010 | |
| 1011 | source "lib/Kconfig.kasan" |
| 1012 | source "lib/Kconfig.kfence" |
| 1013 | source "lib/Kconfig.kmsan" |
| 1014 | |
| 1015 | endmenu # "Memory Debugging" |
| 1016 | |
| 1017 | config DEBUG_SHIRQ |
| 1018 | bool "Debug shared IRQ handlers" |
| 1019 | depends on DEBUG_KERNEL |
| 1020 | help |
| 1021 | Enable this to generate a spurious interrupt just before a shared |
| 1022 | interrupt handler is deregistered (generating one when registering |
| 1023 | is currently disabled). Drivers need to handle this correctly. Some |
| 1024 | don't and need to be caught. |
| 1025 | |
| 1026 | menu "Debug Oops, Lockups and Hangs" |
| 1027 | |
| 1028 | config PANIC_ON_OOPS |
| 1029 | bool "Panic on Oops" |
| 1030 | help |
| 1031 | Say Y here to enable the kernel to panic when it oopses. This |
| 1032 | has the same effect as setting oops=panic on the kernel command |
| 1033 | line. |
| 1034 | |
| 1035 | This feature is useful to ensure that the kernel does not do |
| 1036 | anything erroneous after an oops which could result in data |
| 1037 | corruption or other issues. |
| 1038 | |
| 1039 | Say N if unsure. |
| 1040 | |
| 1041 | config PANIC_ON_OOPS_VALUE |
| 1042 | int |
| 1043 | range 0 1 |
| 1044 | default 0 if !PANIC_ON_OOPS |
| 1045 | default 1 if PANIC_ON_OOPS |
| 1046 | |
| 1047 | config PANIC_TIMEOUT |
| 1048 | int "panic timeout" |
| 1049 | default 0 |
| 1050 | help |
| 1051 | Set the timeout value (in seconds) until a reboot occurs when |
| 1052 | the kernel panics. If n = 0, then we wait forever. A timeout |
| 1053 | value n > 0 will wait n seconds before rebooting, while a timeout |
| 1054 | value n < 0 will reboot immediately. |
| 1055 | |
| 1056 | config LOCKUP_DETECTOR |
| 1057 | bool |
| 1058 | |
| 1059 | config SOFTLOCKUP_DETECTOR |
| 1060 | bool "Detect Soft Lockups" |
| 1061 | depends on DEBUG_KERNEL && !S390 |
| 1062 | select LOCKUP_DETECTOR |
| 1063 | help |
| 1064 | Say Y here to enable the kernel to act as a watchdog to detect |
| 1065 | soft lockups. |
| 1066 | |
| 1067 | Softlockups are bugs that cause the kernel to loop in kernel |
| 1068 | mode for more than 20 seconds, without giving other tasks a |
| 1069 | chance to run. The current stack trace is displayed upon |
| 1070 | detection and the system will stay locked up. |
| 1071 | |
| 1072 | config BOOTPARAM_SOFTLOCKUP_PANIC |
| 1073 | bool "Panic (Reboot) On Soft Lockups" |
| 1074 | depends on SOFTLOCKUP_DETECTOR |
| 1075 | help |
| 1076 | Say Y here to enable the kernel to panic on "soft lockups", |
| 1077 | which are bugs that cause the kernel to loop in kernel |
| 1078 | mode for more than 20 seconds (configurable using the watchdog_thresh |
| 1079 | sysctl), without giving other tasks a chance to run. |
| 1080 | |
| 1081 | The panic can be used in combination with panic_timeout, |
| 1082 | to cause the system to reboot automatically after a |
| 1083 | lockup has been detected. This feature is useful for |
| 1084 | high-availability systems that have uptime guarantees and |
| 1085 | where a lockup must be resolved ASAP. |
| 1086 | |
| 1087 | Say N if unsure. |
| 1088 | |
| 1089 | config HARDLOCKUP_DETECTOR_PERF |
| 1090 | bool |
| 1091 | select SOFTLOCKUP_DETECTOR |
| 1092 | |
| 1093 | # |
| 1094 | # Enables a timestamp based low pass filter to compensate for perf based |
| 1095 | # hard lockup detection which runs too fast due to turbo modes. |
| 1096 | # |
| 1097 | config HARDLOCKUP_CHECK_TIMESTAMP |
| 1098 | bool |
| 1099 | |
| 1100 | # |
| 1101 | # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard |
| 1102 | # lockup detector rather than the perf based detector. |
| 1103 | # |
| 1104 | config HARDLOCKUP_DETECTOR |
| 1105 | bool "Detect Hard Lockups" |
| 1106 | depends on DEBUG_KERNEL && !S390 |
| 1107 | depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH |
| 1108 | select LOCKUP_DETECTOR |
| 1109 | select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF |
| 1110 | help |
| 1111 | Say Y here to enable the kernel to act as a watchdog to detect |
| 1112 | hard lockups. |
| 1113 | |
| 1114 | Hardlockups are bugs that cause the CPU to loop in kernel mode |
| 1115 | for more than 10 seconds, without letting other interrupts have a |
| 1116 | chance to run. The current stack trace is displayed upon detection |
| 1117 | and the system will stay locked up. |
| 1118 | |
| 1119 | config BOOTPARAM_HARDLOCKUP_PANIC |
| 1120 | bool "Panic (Reboot) On Hard Lockups" |
| 1121 | depends on HARDLOCKUP_DETECTOR |
| 1122 | help |
| 1123 | Say Y here to enable the kernel to panic on "hard lockups", |
| 1124 | which are bugs that cause the kernel to loop in kernel |
| 1125 | mode with interrupts disabled for more than 10 seconds (configurable |
| 1126 | using the watchdog_thresh sysctl). |
| 1127 | |
| 1128 | Say N if unsure. |
| 1129 | |
| 1130 | config DETECT_HUNG_TASK |
| 1131 | bool "Detect Hung Tasks" |
| 1132 | depends on DEBUG_KERNEL |
| 1133 | default SOFTLOCKUP_DETECTOR |
| 1134 | help |
| 1135 | Say Y here to enable the kernel to detect "hung tasks", |
| 1136 | which are bugs that cause the task to be stuck in |
| 1137 | uninterruptible "D" state indefinitely. |
| 1138 | |
| 1139 | When a hung task is detected, the kernel will print the |
| 1140 | current stack trace (which you should report), but the |
| 1141 | task will stay in uninterruptible state. If lockdep is |
| 1142 | enabled then all held locks will also be reported. This |
| 1143 | feature has negligible overhead. |
| 1144 | |
| 1145 | config DEFAULT_HUNG_TASK_TIMEOUT |
| 1146 | int "Default timeout for hung task detection (in seconds)" |
| 1147 | depends on DETECT_HUNG_TASK |
| 1148 | default 120 |
| 1149 | help |
| 1150 | This option controls the default timeout (in seconds) used |
| 1151 | to determine when a task has become non-responsive and should |
| 1152 | be considered hung. |
| 1153 | |
| 1154 | It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
| 1155 | sysctl or by writing a value to |
| 1156 | /proc/sys/kernel/hung_task_timeout_secs. |
| 1157 | |
| 1158 | A timeout of 0 disables the check. The default is two minutes. |
| 1159 | Keeping the default should be fine in most cases. |
| 1160 | |
| 1161 | config BOOTPARAM_HUNG_TASK_PANIC |
| 1162 | bool "Panic (Reboot) On Hung Tasks" |
| 1163 | depends on DETECT_HUNG_TASK |
| 1164 | help |
| 1165 | Say Y here to enable the kernel to panic on "hung tasks", |
| 1166 | which are bugs that cause the kernel to leave a task stuck |
| 1167 | in uninterruptible "D" state. |
| 1168 | |
| 1169 | The panic can be used in combination with panic_timeout, |
| 1170 | to cause the system to reboot automatically after a |
| 1171 | hung task has been detected. This feature is useful for |
| 1172 | high-availability systems that have uptime guarantees and |
| 1173 | where a hung tasks must be resolved ASAP. |
| 1174 | |
| 1175 | Say N if unsure. |
| 1176 | |
| 1177 | config WQ_WATCHDOG |
| 1178 | bool "Detect Workqueue Stalls" |
| 1179 | depends on DEBUG_KERNEL |
| 1180 | help |
| 1181 | Say Y here to enable stall detection on workqueues. If a |
| 1182 | worker pool doesn't make forward progress on a pending work |
| 1183 | item for over a given amount of time, 30s by default, a |
| 1184 | warning message is printed along with dump of workqueue |
| 1185 | state. This can be configured through kernel parameter |
| 1186 | "workqueue.watchdog_thresh" and its sysfs counterpart. |
| 1187 | |
| 1188 | config TEST_LOCKUP |
| 1189 | tristate "Test module to generate lockups" |
| 1190 | depends on m |
| 1191 | help |
| 1192 | This builds the "test_lockup" module that helps to make sure |
| 1193 | that watchdogs and lockup detectors are working properly. |
| 1194 | |
| 1195 | Depending on module parameters it could emulate soft or hard |
| 1196 | lockup, "hung task", or locking arbitrary lock for a long time. |
| 1197 | Also it could generate series of lockups with cooling-down periods. |
| 1198 | |
| 1199 | If unsure, say N. |
| 1200 | |
| 1201 | endmenu # "Debug lockups and hangs" |
| 1202 | |
| 1203 | menu "Scheduler Debugging" |
| 1204 | |
| 1205 | config SCHED_DEBUG |
| 1206 | bool "Collect scheduler debugging info" |
| 1207 | depends on DEBUG_KERNEL && PROC_FS |
| 1208 | default y |
| 1209 | help |
| 1210 | If you say Y here, the /proc/sched_debug file will be provided |
| 1211 | that can help debug the scheduler. The runtime overhead of this |
| 1212 | option is minimal. |
| 1213 | |
| 1214 | config SCHED_INFO |
| 1215 | bool |
| 1216 | default n |
| 1217 | |
| 1218 | config SCHEDSTATS |
| 1219 | bool "Collect scheduler statistics" |
| 1220 | depends on DEBUG_KERNEL && PROC_FS |
| 1221 | select SCHED_INFO |
| 1222 | help |
| 1223 | If you say Y here, additional code will be inserted into the |
| 1224 | scheduler and related routines to collect statistics about |
| 1225 | scheduler behavior and provide them in /proc/schedstat. These |
| 1226 | stats may be useful for both tuning and debugging the scheduler |
| 1227 | If you aren't debugging the scheduler or trying to tune a specific |
| 1228 | application, you can say N to avoid the very slight overhead |
| 1229 | this adds. |
| 1230 | |
| 1231 | endmenu |
| 1232 | |
| 1233 | config DEBUG_TIMEKEEPING |
| 1234 | bool "Enable extra timekeeping sanity checking" |
| 1235 | help |
| 1236 | This option will enable additional timekeeping sanity checks |
| 1237 | which may be helpful when diagnosing issues where timekeeping |
| 1238 | problems are suspected. |
| 1239 | |
| 1240 | This may include checks in the timekeeping hotpaths, so this |
| 1241 | option may have a (very small) performance impact to some |
| 1242 | workloads. |
| 1243 | |
| 1244 | If unsure, say N. |
| 1245 | |
| 1246 | config DEBUG_PREEMPT |
| 1247 | bool "Debug preemptible kernel" |
| 1248 | depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT |
| 1249 | default y |
| 1250 | help |
| 1251 | If you say Y here then the kernel will use a debug variant of the |
| 1252 | commonly used smp_processor_id() function and will print warnings |
| 1253 | if kernel code uses it in a preemption-unsafe way. Also, the kernel |
| 1254 | will detect preemption count underflows. |
| 1255 | |
| 1256 | menu "Lock Debugging (spinlocks, mutexes, etc...)" |
| 1257 | |
| 1258 | config LOCK_DEBUGGING_SUPPORT |
| 1259 | bool |
| 1260 | depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT |
| 1261 | default y |
| 1262 | |
| 1263 | config PROVE_LOCKING |
| 1264 | bool "Lock debugging: prove locking correctness" |
| 1265 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1266 | select LOCKDEP |
| 1267 | select DEBUG_SPINLOCK |
| 1268 | select DEBUG_MUTEXES if !PREEMPT_RT |
| 1269 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
| 1270 | select DEBUG_RWSEMS |
| 1271 | select DEBUG_WW_MUTEX_SLOWPATH |
| 1272 | select DEBUG_LOCK_ALLOC |
| 1273 | select PREEMPT_COUNT if !ARCH_NO_PREEMPT |
| 1274 | select TRACE_IRQFLAGS |
| 1275 | default n |
| 1276 | help |
| 1277 | This feature enables the kernel to prove that all locking |
| 1278 | that occurs in the kernel runtime is mathematically |
| 1279 | correct: that under no circumstance could an arbitrary (and |
| 1280 | not yet triggered) combination of observed locking |
| 1281 | sequences (on an arbitrary number of CPUs, running an |
| 1282 | arbitrary number of tasks and interrupt contexts) cause a |
| 1283 | deadlock. |
| 1284 | |
| 1285 | In short, this feature enables the kernel to report locking |
| 1286 | related deadlocks before they actually occur. |
| 1287 | |
| 1288 | The proof does not depend on how hard and complex a |
| 1289 | deadlock scenario would be to trigger: how many |
| 1290 | participant CPUs, tasks and irq-contexts would be needed |
| 1291 | for it to trigger. The proof also does not depend on |
| 1292 | timing: if a race and a resulting deadlock is possible |
| 1293 | theoretically (no matter how unlikely the race scenario |
| 1294 | is), it will be proven so and will immediately be |
| 1295 | reported by the kernel (once the event is observed that |
| 1296 | makes the deadlock theoretically possible). |
| 1297 | |
| 1298 | If a deadlock is impossible (i.e. the locking rules, as |
| 1299 | observed by the kernel, are mathematically correct), the |
| 1300 | kernel reports nothing. |
| 1301 | |
| 1302 | NOTE: this feature can also be enabled for rwlocks, mutexes |
| 1303 | and rwsems - in which case all dependencies between these |
| 1304 | different locking variants are observed and mapped too, and |
| 1305 | the proof of observed correctness is also maintained for an |
| 1306 | arbitrary combination of these separate locking variants. |
| 1307 | |
| 1308 | For more details, see Documentation/locking/lockdep-design.rst. |
| 1309 | |
| 1310 | config PROVE_RAW_LOCK_NESTING |
| 1311 | bool "Enable raw_spinlock - spinlock nesting checks" |
| 1312 | depends on PROVE_LOCKING |
| 1313 | default n |
| 1314 | help |
| 1315 | Enable the raw_spinlock vs. spinlock nesting checks which ensure |
| 1316 | that the lock nesting rules for PREEMPT_RT enabled kernels are |
| 1317 | not violated. |
| 1318 | |
| 1319 | NOTE: There are known nesting problems. So if you enable this |
| 1320 | option expect lockdep splats until these problems have been fully |
| 1321 | addressed which is work in progress. This config switch allows to |
| 1322 | identify and analyze these problems. It will be removed and the |
| 1323 | check permanently enabled once the main issues have been fixed. |
| 1324 | |
| 1325 | If unsure, select N. |
| 1326 | |
| 1327 | config LOCK_STAT |
| 1328 | bool "Lock usage statistics" |
| 1329 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1330 | select LOCKDEP |
| 1331 | select DEBUG_SPINLOCK |
| 1332 | select DEBUG_MUTEXES if !PREEMPT_RT |
| 1333 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
| 1334 | select DEBUG_LOCK_ALLOC |
| 1335 | default n |
| 1336 | help |
| 1337 | This feature enables tracking lock contention points |
| 1338 | |
| 1339 | For more details, see Documentation/locking/lockstat.rst |
| 1340 | |
| 1341 | This also enables lock events required by "perf lock", |
| 1342 | subcommand of perf. |
| 1343 | If you want to use "perf lock", you also need to turn on |
| 1344 | CONFIG_EVENT_TRACING. |
| 1345 | |
| 1346 | CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. |
| 1347 | (CONFIG_LOCKDEP defines "acquire" and "release" events.) |
| 1348 | |
| 1349 | config DEBUG_RT_MUTEXES |
| 1350 | bool "RT Mutex debugging, deadlock detection" |
| 1351 | depends on DEBUG_KERNEL && RT_MUTEXES |
| 1352 | help |
| 1353 | This allows rt mutex semantics violations and rt mutex related |
| 1354 | deadlocks (lockups) to be detected and reported automatically. |
| 1355 | |
| 1356 | config DEBUG_SPINLOCK |
| 1357 | bool "Spinlock and rw-lock debugging: basic checks" |
| 1358 | depends on DEBUG_KERNEL |
| 1359 | select UNINLINE_SPIN_UNLOCK |
| 1360 | help |
| 1361 | Say Y here and build SMP to catch missing spinlock initialization |
| 1362 | and certain other kinds of spinlock errors commonly made. This is |
| 1363 | best used in conjunction with the NMI watchdog so that spinlock |
| 1364 | deadlocks are also debuggable. |
| 1365 | |
| 1366 | config DEBUG_MUTEXES |
| 1367 | bool "Mutex debugging: basic checks" |
| 1368 | depends on DEBUG_KERNEL && !PREEMPT_RT |
| 1369 | help |
| 1370 | This feature allows mutex semantics violations to be detected and |
| 1371 | reported. |
| 1372 | |
| 1373 | config DEBUG_WW_MUTEX_SLOWPATH |
| 1374 | bool "Wait/wound mutex debugging: Slowpath testing" |
| 1375 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1376 | select DEBUG_LOCK_ALLOC |
| 1377 | select DEBUG_SPINLOCK |
| 1378 | select DEBUG_MUTEXES if !PREEMPT_RT |
| 1379 | select DEBUG_RT_MUTEXES if PREEMPT_RT |
| 1380 | help |
| 1381 | This feature enables slowpath testing for w/w mutex users by |
| 1382 | injecting additional -EDEADLK wound/backoff cases. Together with |
| 1383 | the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this |
| 1384 | will test all possible w/w mutex interface abuse with the |
| 1385 | exception of simply not acquiring all the required locks. |
| 1386 | Note that this feature can introduce significant overhead, so |
| 1387 | it really should not be enabled in a production or distro kernel, |
| 1388 | even a debug kernel. If you are a driver writer, enable it. If |
| 1389 | you are a distro, do not. |
| 1390 | |
| 1391 | config DEBUG_RWSEMS |
| 1392 | bool "RW Semaphore debugging: basic checks" |
| 1393 | depends on DEBUG_KERNEL |
| 1394 | help |
| 1395 | This debugging feature allows mismatched rw semaphore locks |
| 1396 | and unlocks to be detected and reported. |
| 1397 | |
| 1398 | config DEBUG_LOCK_ALLOC |
| 1399 | bool "Lock debugging: detect incorrect freeing of live locks" |
| 1400 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1401 | select DEBUG_SPINLOCK |
| 1402 | select DEBUG_MUTEXES if !PREEMPT_RT |
| 1403 | select DEBUG_RT_MUTEXES if RT_MUTEXES |
| 1404 | select LOCKDEP |
| 1405 | help |
| 1406 | This feature will check whether any held lock (spinlock, rwlock, |
| 1407 | mutex or rwsem) is incorrectly freed by the kernel, via any of the |
| 1408 | memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), |
| 1409 | vfree(), etc.), whether a live lock is incorrectly reinitialized via |
| 1410 | spin_lock_init()/mutex_init()/etc., or whether there is any lock |
| 1411 | held during task exit. |
| 1412 | |
| 1413 | config LOCKDEP |
| 1414 | bool |
| 1415 | depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| 1416 | select STACKTRACE |
| 1417 | select KALLSYMS |
| 1418 | select KALLSYMS_ALL |
| 1419 | |
| 1420 | config LOCKDEP_SMALL |
| 1421 | bool |
| 1422 | |
| 1423 | config LOCKDEP_BITS |
| 1424 | int "Bitsize for MAX_LOCKDEP_ENTRIES" |
| 1425 | depends on LOCKDEP && !LOCKDEP_SMALL |
| 1426 | range 10 30 |
| 1427 | default 15 |
| 1428 | help |
| 1429 | Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message. |
| 1430 | |
| 1431 | config LOCKDEP_CHAINS_BITS |
| 1432 | int "Bitsize for MAX_LOCKDEP_CHAINS" |
| 1433 | depends on LOCKDEP && !LOCKDEP_SMALL |
| 1434 | range 10 30 |
| 1435 | default 16 |
| 1436 | help |
| 1437 | Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message. |
| 1438 | |
| 1439 | config LOCKDEP_STACK_TRACE_BITS |
| 1440 | int "Bitsize for MAX_STACK_TRACE_ENTRIES" |
| 1441 | depends on LOCKDEP && !LOCKDEP_SMALL |
| 1442 | range 10 30 |
| 1443 | default 19 |
| 1444 | help |
| 1445 | Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message. |
| 1446 | |
| 1447 | config LOCKDEP_STACK_TRACE_HASH_BITS |
| 1448 | int "Bitsize for STACK_TRACE_HASH_SIZE" |
| 1449 | depends on LOCKDEP && !LOCKDEP_SMALL |
| 1450 | range 10 30 |
| 1451 | default 14 |
| 1452 | help |
| 1453 | Try increasing this value if you need large MAX_STACK_TRACE_ENTRIES. |
| 1454 | |
| 1455 | config LOCKDEP_CIRCULAR_QUEUE_BITS |
| 1456 | int "Bitsize for elements in circular_queue struct" |
| 1457 | depends on LOCKDEP |
| 1458 | range 10 30 |
| 1459 | default 12 |
| 1460 | help |
| 1461 | Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure. |
| 1462 | |
| 1463 | config DEBUG_LOCKDEP |
| 1464 | bool "Lock dependency engine debugging" |
| 1465 | depends on DEBUG_KERNEL && LOCKDEP |
| 1466 | select DEBUG_IRQFLAGS |
| 1467 | help |
| 1468 | If you say Y here, the lock dependency engine will do |
| 1469 | additional runtime checks to debug itself, at the price |
| 1470 | of more runtime overhead. |
| 1471 | |
| 1472 | config DEBUG_ATOMIC_SLEEP |
| 1473 | bool "Sleep inside atomic section checking" |
| 1474 | select PREEMPT_COUNT |
| 1475 | depends on DEBUG_KERNEL |
| 1476 | depends on !ARCH_NO_PREEMPT |
| 1477 | help |
| 1478 | If you say Y here, various routines which may sleep will become very |
| 1479 | noisy if they are called inside atomic sections: when a spinlock is |
| 1480 | held, inside an rcu read side critical section, inside preempt disabled |
| 1481 | sections, inside an interrupt, etc... |
| 1482 | |
| 1483 | config DEBUG_LOCKING_API_SELFTESTS |
| 1484 | bool "Locking API boot-time self-tests" |
| 1485 | depends on DEBUG_KERNEL |
| 1486 | help |
| 1487 | Say Y here if you want the kernel to run a short self-test during |
| 1488 | bootup. The self-test checks whether common types of locking bugs |
| 1489 | are detected by debugging mechanisms or not. (if you disable |
| 1490 | lock debugging then those bugs won't be detected of course.) |
| 1491 | The following locking APIs are covered: spinlocks, rwlocks, |
| 1492 | mutexes and rwsems. |
| 1493 | |
| 1494 | config LOCK_TORTURE_TEST |
| 1495 | tristate "torture tests for locking" |
| 1496 | depends on DEBUG_KERNEL |
| 1497 | select TORTURE_TEST |
| 1498 | help |
| 1499 | This option provides a kernel module that runs torture tests |
| 1500 | on kernel locking primitives. The kernel module may be built |
| 1501 | after the fact on the running kernel to be tested, if desired. |
| 1502 | |
| 1503 | Say Y here if you want kernel locking-primitive torture tests |
| 1504 | to be built into the kernel. |
| 1505 | Say M if you want these torture tests to build as a module. |
| 1506 | Say N if you are unsure. |
| 1507 | |
| 1508 | config WW_MUTEX_SELFTEST |
| 1509 | tristate "Wait/wound mutex selftests" |
| 1510 | help |
| 1511 | This option provides a kernel module that runs tests on the |
| 1512 | on the struct ww_mutex locking API. |
| 1513 | |
| 1514 | It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction |
| 1515 | with this test harness. |
| 1516 | |
| 1517 | Say M if you want these self tests to build as a module. |
| 1518 | Say N if you are unsure. |
| 1519 | |
| 1520 | config SCF_TORTURE_TEST |
| 1521 | tristate "torture tests for smp_call_function*()" |
| 1522 | depends on DEBUG_KERNEL |
| 1523 | select TORTURE_TEST |
| 1524 | help |
| 1525 | This option provides a kernel module that runs torture tests |
| 1526 | on the smp_call_function() family of primitives. The kernel |
| 1527 | module may be built after the fact on the running kernel to |
| 1528 | be tested, if desired. |
| 1529 | |
| 1530 | config CSD_LOCK_WAIT_DEBUG |
| 1531 | bool "Debugging for csd_lock_wait(), called from smp_call_function*()" |
| 1532 | depends on DEBUG_KERNEL |
| 1533 | depends on 64BIT |
| 1534 | default n |
| 1535 | help |
| 1536 | This option enables debug prints when CPUs are slow to respond |
| 1537 | to the smp_call_function*() IPI wrappers. These debug prints |
| 1538 | include the IPI handler function currently executing (if any) |
| 1539 | and relevant stack traces. |
| 1540 | |
| 1541 | endmenu # lock debugging |
| 1542 | |
| 1543 | config TRACE_IRQFLAGS |
| 1544 | depends on TRACE_IRQFLAGS_SUPPORT |
| 1545 | bool |
| 1546 | help |
| 1547 | Enables hooks to interrupt enabling and disabling for |
| 1548 | either tracing or lock debugging. |
| 1549 | |
| 1550 | config TRACE_IRQFLAGS_NMI |
| 1551 | def_bool y |
| 1552 | depends on TRACE_IRQFLAGS |
| 1553 | depends on TRACE_IRQFLAGS_NMI_SUPPORT |
| 1554 | |
| 1555 | config DEBUG_IRQFLAGS |
| 1556 | bool "Debug IRQ flag manipulation" |
| 1557 | help |
| 1558 | Enables checks for potentially unsafe enabling or disabling of |
| 1559 | interrupts, such as calling raw_local_irq_restore() when interrupts |
| 1560 | are enabled. |
| 1561 | |
| 1562 | config STACKTRACE |
| 1563 | bool "Stack backtrace support" |
| 1564 | depends on STACKTRACE_SUPPORT |
| 1565 | help |
| 1566 | This option causes the kernel to create a /proc/pid/stack for |
| 1567 | every process, showing its current stack trace. |
| 1568 | It is also used by various kernel debugging features that require |
| 1569 | stack trace generation. |
| 1570 | |
| 1571 | config WARN_ALL_UNSEEDED_RANDOM |
| 1572 | bool "Warn for all uses of unseeded randomness" |
| 1573 | default n |
| 1574 | help |
| 1575 | Some parts of the kernel contain bugs relating to their use of |
| 1576 | cryptographically secure random numbers before it's actually possible |
| 1577 | to generate those numbers securely. This setting ensures that these |
| 1578 | flaws don't go unnoticed, by enabling a message, should this ever |
| 1579 | occur. This will allow people with obscure setups to know when things |
| 1580 | are going wrong, so that they might contact developers about fixing |
| 1581 | it. |
| 1582 | |
| 1583 | Unfortunately, on some models of some architectures getting |
| 1584 | a fully seeded CRNG is extremely difficult, and so this can |
| 1585 | result in dmesg getting spammed for a surprisingly long |
| 1586 | time. This is really bad from a security perspective, and |
| 1587 | so architecture maintainers really need to do what they can |
| 1588 | to get the CRNG seeded sooner after the system is booted. |
| 1589 | However, since users cannot do anything actionable to |
| 1590 | address this, by default this option is disabled. |
| 1591 | |
| 1592 | Say Y here if you want to receive warnings for all uses of |
| 1593 | unseeded randomness. This will be of use primarily for |
| 1594 | those developers interested in improving the security of |
| 1595 | Linux kernels running on their architecture (or |
| 1596 | subarchitecture). |
| 1597 | |
| 1598 | config DEBUG_KOBJECT |
| 1599 | bool "kobject debugging" |
| 1600 | depends on DEBUG_KERNEL |
| 1601 | help |
| 1602 | If you say Y here, some extra kobject debugging messages will be sent |
| 1603 | to the syslog. |
| 1604 | |
| 1605 | config DEBUG_KOBJECT_RELEASE |
| 1606 | bool "kobject release debugging" |
| 1607 | depends on DEBUG_OBJECTS_TIMERS |
| 1608 | help |
| 1609 | kobjects are reference counted objects. This means that their |
| 1610 | last reference count put is not predictable, and the kobject can |
| 1611 | live on past the point at which a driver decides to drop its |
| 1612 | initial reference to the kobject gained on allocation. An |
| 1613 | example of this would be a struct device which has just been |
| 1614 | unregistered. |
| 1615 | |
| 1616 | However, some buggy drivers assume that after such an operation, |
| 1617 | the memory backing the kobject can be immediately freed. This |
| 1618 | goes completely against the principles of a refcounted object. |
| 1619 | |
| 1620 | If you say Y here, the kernel will delay the release of kobjects |
| 1621 | on the last reference count to improve the visibility of this |
| 1622 | kind of kobject release bug. |
| 1623 | |
| 1624 | config HAVE_DEBUG_BUGVERBOSE |
| 1625 | bool |
| 1626 | |
| 1627 | menu "Debug kernel data structures" |
| 1628 | |
| 1629 | config DEBUG_LIST |
| 1630 | bool "Debug linked list manipulation" |
| 1631 | depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION |
| 1632 | help |
| 1633 | Enable this to turn on extended checks in the linked-list |
| 1634 | walking routines. |
| 1635 | |
| 1636 | If unsure, say N. |
| 1637 | |
| 1638 | config DEBUG_PLIST |
| 1639 | bool "Debug priority linked list manipulation" |
| 1640 | depends on DEBUG_KERNEL |
| 1641 | help |
| 1642 | Enable this to turn on extended checks in the priority-ordered |
| 1643 | linked-list (plist) walking routines. This checks the entire |
| 1644 | list multiple times during each manipulation. |
| 1645 | |
| 1646 | If unsure, say N. |
| 1647 | |
| 1648 | config DEBUG_SG |
| 1649 | bool "Debug SG table operations" |
| 1650 | depends on DEBUG_KERNEL |
| 1651 | help |
| 1652 | Enable this to turn on checks on scatter-gather tables. This can |
| 1653 | help find problems with drivers that do not properly initialize |
| 1654 | their sg tables. |
| 1655 | |
| 1656 | If unsure, say N. |
| 1657 | |
| 1658 | config DEBUG_NOTIFIERS |
| 1659 | bool "Debug notifier call chains" |
| 1660 | depends on DEBUG_KERNEL |
| 1661 | help |
| 1662 | Enable this to turn on sanity checking for notifier call chains. |
| 1663 | This is most useful for kernel developers to make sure that |
| 1664 | modules properly unregister themselves from notifier chains. |
| 1665 | This is a relatively cheap check but if you care about maximum |
| 1666 | performance, say N. |
| 1667 | |
| 1668 | config BUG_ON_DATA_CORRUPTION |
| 1669 | bool "Trigger a BUG when data corruption is detected" |
| 1670 | select DEBUG_LIST |
| 1671 | help |
| 1672 | Select this option if the kernel should BUG when it encounters |
| 1673 | data corruption in kernel memory structures when they get checked |
| 1674 | for validity. |
| 1675 | |
| 1676 | If unsure, say N. |
| 1677 | |
| 1678 | config DEBUG_MAPLE_TREE |
| 1679 | bool "Debug maple trees" |
| 1680 | depends on DEBUG_KERNEL |
| 1681 | help |
| 1682 | Enable maple tree debugging information and extra validations. |
| 1683 | |
| 1684 | If unsure, say N. |
| 1685 | |
| 1686 | endmenu |
| 1687 | |
| 1688 | config DEBUG_CREDENTIALS |
| 1689 | bool "Debug credential management" |
| 1690 | depends on DEBUG_KERNEL |
| 1691 | help |
| 1692 | Enable this to turn on some debug checking for credential |
| 1693 | management. The additional code keeps track of the number of |
| 1694 | pointers from task_structs to any given cred struct, and checks to |
| 1695 | see that this number never exceeds the usage count of the cred |
| 1696 | struct. |
| 1697 | |
| 1698 | Furthermore, if SELinux is enabled, this also checks that the |
| 1699 | security pointer in the cred struct is never seen to be invalid. |
| 1700 | |
| 1701 | If unsure, say N. |
| 1702 | |
| 1703 | source "kernel/rcu/Kconfig.debug" |
| 1704 | |
| 1705 | config DEBUG_WQ_FORCE_RR_CPU |
| 1706 | bool "Force round-robin CPU selection for unbound work items" |
| 1707 | depends on DEBUG_KERNEL |
| 1708 | default n |
| 1709 | help |
| 1710 | Workqueue used to implicitly guarantee that work items queued |
| 1711 | without explicit CPU specified are put on the local CPU. This |
| 1712 | guarantee is no longer true and while local CPU is still |
| 1713 | preferred work items may be put on foreign CPUs. Kernel |
| 1714 | parameter "workqueue.debug_force_rr_cpu" is added to force |
| 1715 | round-robin CPU selection to flush out usages which depend on the |
| 1716 | now broken guarantee. This config option enables the debug |
| 1717 | feature by default. When enabled, memory and cache locality will |
| 1718 | be impacted. |
| 1719 | |
| 1720 | config CPU_HOTPLUG_STATE_CONTROL |
| 1721 | bool "Enable CPU hotplug state control" |
| 1722 | depends on DEBUG_KERNEL |
| 1723 | depends on HOTPLUG_CPU |
| 1724 | default n |
| 1725 | help |
| 1726 | Allows to write steps between "offline" and "online" to the CPUs |
| 1727 | sysfs target file so states can be stepped granular. This is a debug |
| 1728 | option for now as the hotplug machinery cannot be stopped and |
| 1729 | restarted at arbitrary points yet. |
| 1730 | |
| 1731 | Say N if your are unsure. |
| 1732 | |
| 1733 | config LATENCYTOP |
| 1734 | bool "Latency measuring infrastructure" |
| 1735 | depends on DEBUG_KERNEL |
| 1736 | depends on STACKTRACE_SUPPORT |
| 1737 | depends on PROC_FS |
| 1738 | depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86 |
| 1739 | select KALLSYMS |
| 1740 | select KALLSYMS_ALL |
| 1741 | select STACKTRACE |
| 1742 | select SCHEDSTATS |
| 1743 | help |
| 1744 | Enable this option if you want to use the LatencyTOP tool |
| 1745 | to find out which userspace is blocking on what kernel operations. |
| 1746 | |
| 1747 | config DEBUG_CGROUP_REF |
| 1748 | bool "Disable inlining of cgroup css reference count functions" |
| 1749 | depends on DEBUG_KERNEL |
| 1750 | depends on CGROUPS |
| 1751 | depends on KPROBES |
| 1752 | default n |
| 1753 | help |
| 1754 | Force cgroup css reference count functions to not be inlined so |
| 1755 | that they can be kprobed for debugging. |
| 1756 | |
| 1757 | source "kernel/trace/Kconfig" |
| 1758 | |
| 1759 | config PROVIDE_OHCI1394_DMA_INIT |
| 1760 | bool "Remote debugging over FireWire early on boot" |
| 1761 | depends on PCI && X86 |
| 1762 | help |
| 1763 | If you want to debug problems which hang or crash the kernel early |
| 1764 | on boot and the crashing machine has a FireWire port, you can use |
| 1765 | this feature to remotely access the memory of the crashed machine |
| 1766 | over FireWire. This employs remote DMA as part of the OHCI1394 |
| 1767 | specification which is now the standard for FireWire controllers. |
| 1768 | |
| 1769 | With remote DMA, you can monitor the printk buffer remotely using |
| 1770 | firescope and access all memory below 4GB using fireproxy from gdb. |
| 1771 | Even controlling a kernel debugger is possible using remote DMA. |
| 1772 | |
| 1773 | Usage: |
| 1774 | |
| 1775 | If ohci1394_dma=early is used as boot parameter, it will initialize |
| 1776 | all OHCI1394 controllers which are found in the PCI config space. |
| 1777 | |
| 1778 | As all changes to the FireWire bus such as enabling and disabling |
| 1779 | devices cause a bus reset and thereby disable remote DMA for all |
| 1780 | devices, be sure to have the cable plugged and FireWire enabled on |
| 1781 | the debugging host before booting the debug target for debugging. |
| 1782 | |
| 1783 | This code (~1k) is freed after boot. By then, the firewire stack |
| 1784 | in charge of the OHCI-1394 controllers should be used instead. |
| 1785 | |
| 1786 | See Documentation/core-api/debugging-via-ohci1394.rst for more information. |
| 1787 | |
| 1788 | source "samples/Kconfig" |
| 1789 | |
| 1790 | config ARCH_HAS_DEVMEM_IS_ALLOWED |
| 1791 | bool |
| 1792 | |
| 1793 | config STRICT_DEVMEM |
| 1794 | bool "Filter access to /dev/mem" |
| 1795 | depends on MMU && DEVMEM |
| 1796 | depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED |
| 1797 | default y if PPC || X86 || ARM64 |
| 1798 | help |
| 1799 | If this option is disabled, you allow userspace (root) access to all |
| 1800 | of memory, including kernel and userspace memory. Accidental |
| 1801 | access to this is obviously disastrous, but specific access can |
| 1802 | be used by people debugging the kernel. Note that with PAT support |
| 1803 | enabled, even in this case there are restrictions on /dev/mem |
| 1804 | use due to the cache aliasing requirements. |
| 1805 | |
| 1806 | If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem |
| 1807 | file only allows userspace access to PCI space and the BIOS code and |
| 1808 | data regions. This is sufficient for dosemu and X and all common |
| 1809 | users of /dev/mem. |
| 1810 | |
| 1811 | If in doubt, say Y. |
| 1812 | |
| 1813 | config IO_STRICT_DEVMEM |
| 1814 | bool "Filter I/O access to /dev/mem" |
| 1815 | depends on STRICT_DEVMEM |
| 1816 | help |
| 1817 | If this option is disabled, you allow userspace (root) access to all |
| 1818 | io-memory regardless of whether a driver is actively using that |
| 1819 | range. Accidental access to this is obviously disastrous, but |
| 1820 | specific access can be used by people debugging kernel drivers. |
| 1821 | |
| 1822 | If this option is switched on, the /dev/mem file only allows |
| 1823 | userspace access to *idle* io-memory ranges (see /proc/iomem) This |
| 1824 | may break traditional users of /dev/mem (dosemu, legacy X, etc...) |
| 1825 | if the driver using a given range cannot be disabled. |
| 1826 | |
| 1827 | If in doubt, say Y. |
| 1828 | |
| 1829 | menu "$(SRCARCH) Debugging" |
| 1830 | |
| 1831 | source "arch/$(SRCARCH)/Kconfig.debug" |
| 1832 | |
| 1833 | endmenu |
| 1834 | |
| 1835 | menu "Kernel Testing and Coverage" |
| 1836 | |
| 1837 | source "lib/kunit/Kconfig" |
| 1838 | |
| 1839 | config NOTIFIER_ERROR_INJECTION |
| 1840 | tristate "Notifier error injection" |
| 1841 | depends on DEBUG_KERNEL |
| 1842 | select DEBUG_FS |
| 1843 | help |
| 1844 | This option provides the ability to inject artificial errors to |
| 1845 | specified notifier chain callbacks. It is useful to test the error |
| 1846 | handling of notifier call chain failures. |
| 1847 | |
| 1848 | Say N if unsure. |
| 1849 | |
| 1850 | config PM_NOTIFIER_ERROR_INJECT |
| 1851 | tristate "PM notifier error injection module" |
| 1852 | depends on PM && NOTIFIER_ERROR_INJECTION |
| 1853 | default m if PM_DEBUG |
| 1854 | help |
| 1855 | This option provides the ability to inject artificial errors to |
| 1856 | PM notifier chain callbacks. It is controlled through debugfs |
| 1857 | interface /sys/kernel/debug/notifier-error-inject/pm |
| 1858 | |
| 1859 | If the notifier call chain should be failed with some events |
| 1860 | notified, write the error code to "actions/<notifier event>/error". |
| 1861 | |
| 1862 | Example: Inject PM suspend error (-12 = -ENOMEM) |
| 1863 | |
| 1864 | # cd /sys/kernel/debug/notifier-error-inject/pm/ |
| 1865 | # echo -12 > actions/PM_SUSPEND_PREPARE/error |
| 1866 | # echo mem > /sys/power/state |
| 1867 | bash: echo: write error: Cannot allocate memory |
| 1868 | |
| 1869 | To compile this code as a module, choose M here: the module will |
| 1870 | be called pm-notifier-error-inject. |
| 1871 | |
| 1872 | If unsure, say N. |
| 1873 | |
| 1874 | config OF_RECONFIG_NOTIFIER_ERROR_INJECT |
| 1875 | tristate "OF reconfig notifier error injection module" |
| 1876 | depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION |
| 1877 | help |
| 1878 | This option provides the ability to inject artificial errors to |
| 1879 | OF reconfig notifier chain callbacks. It is controlled |
| 1880 | through debugfs interface under |
| 1881 | /sys/kernel/debug/notifier-error-inject/OF-reconfig/ |
| 1882 | |
| 1883 | If the notifier call chain should be failed with some events |
| 1884 | notified, write the error code to "actions/<notifier event>/error". |
| 1885 | |
| 1886 | To compile this code as a module, choose M here: the module will |
| 1887 | be called of-reconfig-notifier-error-inject. |
| 1888 | |
| 1889 | If unsure, say N. |
| 1890 | |
| 1891 | config NETDEV_NOTIFIER_ERROR_INJECT |
| 1892 | tristate "Netdev notifier error injection module" |
| 1893 | depends on NET && NOTIFIER_ERROR_INJECTION |
| 1894 | help |
| 1895 | This option provides the ability to inject artificial errors to |
| 1896 | netdevice notifier chain callbacks. It is controlled through debugfs |
| 1897 | interface /sys/kernel/debug/notifier-error-inject/netdev |
| 1898 | |
| 1899 | If the notifier call chain should be failed with some events |
| 1900 | notified, write the error code to "actions/<notifier event>/error". |
| 1901 | |
| 1902 | Example: Inject netdevice mtu change error (-22 = -EINVAL) |
| 1903 | |
| 1904 | # cd /sys/kernel/debug/notifier-error-inject/netdev |
| 1905 | # echo -22 > actions/NETDEV_CHANGEMTU/error |
| 1906 | # ip link set eth0 mtu 1024 |
| 1907 | RTNETLINK answers: Invalid argument |
| 1908 | |
| 1909 | To compile this code as a module, choose M here: the module will |
| 1910 | be called netdev-notifier-error-inject. |
| 1911 | |
| 1912 | If unsure, say N. |
| 1913 | |
| 1914 | config FUNCTION_ERROR_INJECTION |
| 1915 | bool "Fault-injections of functions" |
| 1916 | depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES |
| 1917 | help |
| 1918 | Add fault injections into various functions that are annotated with |
| 1919 | ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return |
| 1920 | value of theses functions. This is useful to test error paths of code. |
| 1921 | |
| 1922 | If unsure, say N |
| 1923 | |
| 1924 | config FAULT_INJECTION |
| 1925 | bool "Fault-injection framework" |
| 1926 | depends on DEBUG_KERNEL |
| 1927 | help |
| 1928 | Provide fault-injection framework. |
| 1929 | For more details, see Documentation/fault-injection/. |
| 1930 | |
| 1931 | config FAILSLAB |
| 1932 | bool "Fault-injection capability for kmalloc" |
| 1933 | depends on FAULT_INJECTION |
| 1934 | depends on SLAB || SLUB |
| 1935 | help |
| 1936 | Provide fault-injection capability for kmalloc. |
| 1937 | |
| 1938 | config FAIL_PAGE_ALLOC |
| 1939 | bool "Fault-injection capability for alloc_pages()" |
| 1940 | depends on FAULT_INJECTION |
| 1941 | help |
| 1942 | Provide fault-injection capability for alloc_pages(). |
| 1943 | |
| 1944 | config FAULT_INJECTION_USERCOPY |
| 1945 | bool "Fault injection capability for usercopy functions" |
| 1946 | depends on FAULT_INJECTION |
| 1947 | help |
| 1948 | Provides fault-injection capability to inject failures |
| 1949 | in usercopy functions (copy_from_user(), get_user(), ...). |
| 1950 | |
| 1951 | config FAIL_MAKE_REQUEST |
| 1952 | bool "Fault-injection capability for disk IO" |
| 1953 | depends on FAULT_INJECTION && BLOCK |
| 1954 | help |
| 1955 | Provide fault-injection capability for disk IO. |
| 1956 | |
| 1957 | config FAIL_IO_TIMEOUT |
| 1958 | bool "Fault-injection capability for faking disk interrupts" |
| 1959 | depends on FAULT_INJECTION && BLOCK |
| 1960 | help |
| 1961 | Provide fault-injection capability on end IO handling. This |
| 1962 | will make the block layer "forget" an interrupt as configured, |
| 1963 | thus exercising the error handling. |
| 1964 | |
| 1965 | Only works with drivers that use the generic timeout handling, |
| 1966 | for others it won't do anything. |
| 1967 | |
| 1968 | config FAIL_FUTEX |
| 1969 | bool "Fault-injection capability for futexes" |
| 1970 | select DEBUG_FS |
| 1971 | depends on FAULT_INJECTION && FUTEX |
| 1972 | help |
| 1973 | Provide fault-injection capability for futexes. |
| 1974 | |
| 1975 | config FAULT_INJECTION_DEBUG_FS |
| 1976 | bool "Debugfs entries for fault-injection capabilities" |
| 1977 | depends on FAULT_INJECTION && SYSFS && DEBUG_FS |
| 1978 | help |
| 1979 | Enable configuration of fault-injection capabilities via debugfs. |
| 1980 | |
| 1981 | config FAIL_FUNCTION |
| 1982 | bool "Fault-injection capability for functions" |
| 1983 | depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION |
| 1984 | help |
| 1985 | Provide function-based fault-injection capability. |
| 1986 | This will allow you to override a specific function with a return |
| 1987 | with given return value. As a result, function caller will see |
| 1988 | an error value and have to handle it. This is useful to test the |
| 1989 | error handling in various subsystems. |
| 1990 | |
| 1991 | config FAIL_MMC_REQUEST |
| 1992 | bool "Fault-injection capability for MMC IO" |
| 1993 | depends on FAULT_INJECTION_DEBUG_FS && MMC |
| 1994 | help |
| 1995 | Provide fault-injection capability for MMC IO. |
| 1996 | This will make the mmc core return data errors. This is |
| 1997 | useful to test the error handling in the mmc block device |
| 1998 | and to test how the mmc host driver handles retries from |
| 1999 | the block device. |
| 2000 | |
| 2001 | config FAIL_SUNRPC |
| 2002 | bool "Fault-injection capability for SunRPC" |
| 2003 | depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG |
| 2004 | help |
| 2005 | Provide fault-injection capability for SunRPC and |
| 2006 | its consumers. |
| 2007 | |
| 2008 | config FAULT_INJECTION_STACKTRACE_FILTER |
| 2009 | bool "stacktrace filter for fault-injection capabilities" |
| 2010 | depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
| 2011 | select STACKTRACE |
| 2012 | depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86 |
| 2013 | help |
| 2014 | Provide stacktrace filter for fault-injection capabilities |
| 2015 | |
| 2016 | config ARCH_HAS_KCOV |
| 2017 | bool |
| 2018 | help |
| 2019 | An architecture should select this when it can successfully |
| 2020 | build and run with CONFIG_KCOV. This typically requires |
| 2021 | disabling instrumentation for some early boot code. |
| 2022 | |
| 2023 | config CC_HAS_SANCOV_TRACE_PC |
| 2024 | def_bool $(cc-option,-fsanitize-coverage=trace-pc) |
| 2025 | |
| 2026 | |
| 2027 | config KCOV |
| 2028 | bool "Code coverage for fuzzing" |
| 2029 | depends on ARCH_HAS_KCOV |
| 2030 | depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS |
| 2031 | depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \ |
| 2032 | GCC_VERSION >= 120000 || CLANG_VERSION >= 130000 |
| 2033 | select DEBUG_FS |
| 2034 | select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC |
| 2035 | select OBJTOOL if HAVE_NOINSTR_HACK |
| 2036 | help |
| 2037 | KCOV exposes kernel code coverage information in a form suitable |
| 2038 | for coverage-guided fuzzing (randomized testing). |
| 2039 | |
| 2040 | If RANDOMIZE_BASE is enabled, PC values will not be stable across |
| 2041 | different machines and across reboots. If you need stable PC values, |
| 2042 | disable RANDOMIZE_BASE. |
| 2043 | |
| 2044 | For more details, see Documentation/dev-tools/kcov.rst. |
| 2045 | |
| 2046 | config KCOV_ENABLE_COMPARISONS |
| 2047 | bool "Enable comparison operands collection by KCOV" |
| 2048 | depends on KCOV |
| 2049 | depends on $(cc-option,-fsanitize-coverage=trace-cmp) |
| 2050 | help |
| 2051 | KCOV also exposes operands of every comparison in the instrumented |
| 2052 | code along with operand sizes and PCs of the comparison instructions. |
| 2053 | These operands can be used by fuzzing engines to improve the quality |
| 2054 | of fuzzing coverage. |
| 2055 | |
| 2056 | config KCOV_INSTRUMENT_ALL |
| 2057 | bool "Instrument all code by default" |
| 2058 | depends on KCOV |
| 2059 | default y |
| 2060 | help |
| 2061 | If you are doing generic system call fuzzing (like e.g. syzkaller), |
| 2062 | then you will want to instrument the whole kernel and you should |
| 2063 | say y here. If you are doing more targeted fuzzing (like e.g. |
| 2064 | filesystem fuzzing with AFL) then you will want to enable coverage |
| 2065 | for more specific subsets of files, and should say n here. |
| 2066 | |
| 2067 | config KCOV_IRQ_AREA_SIZE |
| 2068 | hex "Size of interrupt coverage collection area in words" |
| 2069 | depends on KCOV |
| 2070 | default 0x40000 |
| 2071 | help |
| 2072 | KCOV uses preallocated per-cpu areas to collect coverage from |
| 2073 | soft interrupts. This specifies the size of those areas in the |
| 2074 | number of unsigned long words. |
| 2075 | |
| 2076 | menuconfig RUNTIME_TESTING_MENU |
| 2077 | bool "Runtime Testing" |
| 2078 | def_bool y |
| 2079 | |
| 2080 | if RUNTIME_TESTING_MENU |
| 2081 | |
| 2082 | config LKDTM |
| 2083 | tristate "Linux Kernel Dump Test Tool Module" |
| 2084 | depends on DEBUG_FS |
| 2085 | help |
| 2086 | This module enables testing of the different dumping mechanisms by |
| 2087 | inducing system failures at predefined crash points. |
| 2088 | If you don't need it: say N |
| 2089 | Choose M here to compile this code as a module. The module will be |
| 2090 | called lkdtm. |
| 2091 | |
| 2092 | Documentation on how to use the module can be found in |
| 2093 | Documentation/fault-injection/provoke-crashes.rst |
| 2094 | |
| 2095 | config CPUMASK_KUNIT_TEST |
| 2096 | tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS |
| 2097 | depends on KUNIT |
| 2098 | default KUNIT_ALL_TESTS |
| 2099 | help |
| 2100 | Enable to turn on cpumask tests, running at boot or module load time. |
| 2101 | |
| 2102 | For more information on KUnit and unit tests in general, please refer |
| 2103 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2104 | |
| 2105 | If unsure, say N. |
| 2106 | |
| 2107 | config TEST_LIST_SORT |
| 2108 | tristate "Linked list sorting test" if !KUNIT_ALL_TESTS |
| 2109 | depends on KUNIT |
| 2110 | default KUNIT_ALL_TESTS |
| 2111 | help |
| 2112 | Enable this to turn on 'list_sort()' function test. This test is |
| 2113 | executed only once during system boot (so affects only boot time), |
| 2114 | or at module load time. |
| 2115 | |
| 2116 | If unsure, say N. |
| 2117 | |
| 2118 | config TEST_MIN_HEAP |
| 2119 | tristate "Min heap test" |
| 2120 | depends on DEBUG_KERNEL || m |
| 2121 | help |
| 2122 | Enable this to turn on min heap function tests. This test is |
| 2123 | executed only once during system boot (so affects only boot time), |
| 2124 | or at module load time. |
| 2125 | |
| 2126 | If unsure, say N. |
| 2127 | |
| 2128 | config TEST_SORT |
| 2129 | tristate "Array-based sort test" if !KUNIT_ALL_TESTS |
| 2130 | depends on KUNIT |
| 2131 | default KUNIT_ALL_TESTS |
| 2132 | help |
| 2133 | This option enables the self-test function of 'sort()' at boot, |
| 2134 | or at module load time. |
| 2135 | |
| 2136 | If unsure, say N. |
| 2137 | |
| 2138 | config TEST_DIV64 |
| 2139 | tristate "64bit/32bit division and modulo test" |
| 2140 | depends on DEBUG_KERNEL || m |
| 2141 | help |
| 2142 | Enable this to turn on 'do_div()' function test. This test is |
| 2143 | executed only once during system boot (so affects only boot time), |
| 2144 | or at module load time. |
| 2145 | |
| 2146 | If unsure, say N. |
| 2147 | |
| 2148 | config KPROBES_SANITY_TEST |
| 2149 | tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS |
| 2150 | depends on DEBUG_KERNEL |
| 2151 | depends on KPROBES |
| 2152 | depends on KUNIT |
| 2153 | select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE |
| 2154 | default KUNIT_ALL_TESTS |
| 2155 | help |
| 2156 | This option provides for testing basic kprobes functionality on |
| 2157 | boot. Samples of kprobe and kretprobe are inserted and |
| 2158 | verified for functionality. |
| 2159 | |
| 2160 | Say N if you are unsure. |
| 2161 | |
| 2162 | config FPROBE_SANITY_TEST |
| 2163 | bool "Self test for fprobe" |
| 2164 | depends on DEBUG_KERNEL |
| 2165 | depends on FPROBE |
| 2166 | depends on KUNIT=y |
| 2167 | help |
| 2168 | This option will enable testing the fprobe when the system boot. |
| 2169 | A series of tests are made to verify that the fprobe is functioning |
| 2170 | properly. |
| 2171 | |
| 2172 | Say N if you are unsure. |
| 2173 | |
| 2174 | config BACKTRACE_SELF_TEST |
| 2175 | tristate "Self test for the backtrace code" |
| 2176 | depends on DEBUG_KERNEL |
| 2177 | help |
| 2178 | This option provides a kernel module that can be used to test |
| 2179 | the kernel stack backtrace code. This option is not useful |
| 2180 | for distributions or general kernels, but only for kernel |
| 2181 | developers working on architecture code. |
| 2182 | |
| 2183 | Note that if you want to also test saved backtraces, you will |
| 2184 | have to enable STACKTRACE as well. |
| 2185 | |
| 2186 | Say N if you are unsure. |
| 2187 | |
| 2188 | config TEST_REF_TRACKER |
| 2189 | tristate "Self test for reference tracker" |
| 2190 | depends on DEBUG_KERNEL && STACKTRACE_SUPPORT |
| 2191 | select REF_TRACKER |
| 2192 | help |
| 2193 | This option provides a kernel module performing tests |
| 2194 | using reference tracker infrastructure. |
| 2195 | |
| 2196 | Say N if you are unsure. |
| 2197 | |
| 2198 | config RBTREE_TEST |
| 2199 | tristate "Red-Black tree test" |
| 2200 | depends on DEBUG_KERNEL |
| 2201 | help |
| 2202 | A benchmark measuring the performance of the rbtree library. |
| 2203 | Also includes rbtree invariant checks. |
| 2204 | |
| 2205 | config REED_SOLOMON_TEST |
| 2206 | tristate "Reed-Solomon library test" |
| 2207 | depends on DEBUG_KERNEL || m |
| 2208 | select REED_SOLOMON |
| 2209 | select REED_SOLOMON_ENC16 |
| 2210 | select REED_SOLOMON_DEC16 |
| 2211 | help |
| 2212 | This option enables the self-test function of rslib at boot, |
| 2213 | or at module load time. |
| 2214 | |
| 2215 | If unsure, say N. |
| 2216 | |
| 2217 | config INTERVAL_TREE_TEST |
| 2218 | tristate "Interval tree test" |
| 2219 | depends on DEBUG_KERNEL |
| 2220 | select INTERVAL_TREE |
| 2221 | help |
| 2222 | A benchmark measuring the performance of the interval tree library |
| 2223 | |
| 2224 | config PERCPU_TEST |
| 2225 | tristate "Per cpu operations test" |
| 2226 | depends on m && DEBUG_KERNEL |
| 2227 | help |
| 2228 | Enable this option to build test module which validates per-cpu |
| 2229 | operations. |
| 2230 | |
| 2231 | If unsure, say N. |
| 2232 | |
| 2233 | config ATOMIC64_SELFTEST |
| 2234 | tristate "Perform an atomic64_t self-test" |
| 2235 | help |
| 2236 | Enable this option to test the atomic64_t functions at boot or |
| 2237 | at module load time. |
| 2238 | |
| 2239 | If unsure, say N. |
| 2240 | |
| 2241 | config ASYNC_RAID6_TEST |
| 2242 | tristate "Self test for hardware accelerated raid6 recovery" |
| 2243 | depends on ASYNC_RAID6_RECOV |
| 2244 | select ASYNC_MEMCPY |
| 2245 | help |
| 2246 | This is a one-shot self test that permutes through the |
| 2247 | recovery of all the possible two disk failure scenarios for a |
| 2248 | N-disk array. Recovery is performed with the asynchronous |
| 2249 | raid6 recovery routines, and will optionally use an offload |
| 2250 | engine if one is available. |
| 2251 | |
| 2252 | If unsure, say N. |
| 2253 | |
| 2254 | config TEST_HEXDUMP |
| 2255 | tristate "Test functions located in the hexdump module at runtime" |
| 2256 | |
| 2257 | config STRING_SELFTEST |
| 2258 | tristate "Test string functions at runtime" |
| 2259 | |
| 2260 | config TEST_STRING_HELPERS |
| 2261 | tristate "Test functions located in the string_helpers module at runtime" |
| 2262 | |
| 2263 | config TEST_KSTRTOX |
| 2264 | tristate "Test kstrto*() family of functions at runtime" |
| 2265 | |
| 2266 | config TEST_PRINTF |
| 2267 | tristate "Test printf() family of functions at runtime" |
| 2268 | |
| 2269 | config TEST_SCANF |
| 2270 | tristate "Test scanf() family of functions at runtime" |
| 2271 | |
| 2272 | config TEST_BITMAP |
| 2273 | tristate "Test bitmap_*() family of functions at runtime" |
| 2274 | help |
| 2275 | Enable this option to test the bitmap functions at boot. |
| 2276 | |
| 2277 | If unsure, say N. |
| 2278 | |
| 2279 | config TEST_UUID |
| 2280 | tristate "Test functions located in the uuid module at runtime" |
| 2281 | |
| 2282 | config TEST_XARRAY |
| 2283 | tristate "Test the XArray code at runtime" |
| 2284 | |
| 2285 | config TEST_MAPLE_TREE |
| 2286 | depends on DEBUG_KERNEL |
| 2287 | select DEBUG_MAPLE_TREE |
| 2288 | tristate "Test the Maple Tree code at runtime" |
| 2289 | |
| 2290 | config TEST_RHASHTABLE |
| 2291 | tristate "Perform selftest on resizable hash table" |
| 2292 | help |
| 2293 | Enable this option to test the rhashtable functions at boot. |
| 2294 | |
| 2295 | If unsure, say N. |
| 2296 | |
| 2297 | config TEST_IDA |
| 2298 | tristate "Perform selftest on IDA functions" |
| 2299 | |
| 2300 | config TEST_PARMAN |
| 2301 | tristate "Perform selftest on priority array manager" |
| 2302 | depends on PARMAN |
| 2303 | help |
| 2304 | Enable this option to test priority array manager on boot |
| 2305 | (or module load). |
| 2306 | |
| 2307 | If unsure, say N. |
| 2308 | |
| 2309 | config TEST_IRQ_TIMINGS |
| 2310 | bool "IRQ timings selftest" |
| 2311 | depends on IRQ_TIMINGS |
| 2312 | help |
| 2313 | Enable this option to test the irq timings code on boot. |
| 2314 | |
| 2315 | If unsure, say N. |
| 2316 | |
| 2317 | config TEST_LKM |
| 2318 | tristate "Test module loading with 'hello world' module" |
| 2319 | depends on m |
| 2320 | help |
| 2321 | This builds the "test_module" module that emits "Hello, world" |
| 2322 | on printk when loaded. It is designed to be used for basic |
| 2323 | evaluation of the module loading subsystem (for example when |
| 2324 | validating module verification). It lacks any extra dependencies, |
| 2325 | and will not normally be loaded by the system unless explicitly |
| 2326 | requested by name. |
| 2327 | |
| 2328 | If unsure, say N. |
| 2329 | |
| 2330 | config TEST_BITOPS |
| 2331 | tristate "Test module for compilation of bitops operations" |
| 2332 | depends on m |
| 2333 | help |
| 2334 | This builds the "test_bitops" module that is much like the |
| 2335 | TEST_LKM module except that it does a basic exercise of the |
| 2336 | set/clear_bit macros and get_count_order/long to make sure there are |
| 2337 | no compiler warnings from C=1 sparse checker or -Wextra |
| 2338 | compilations. It has no dependencies and doesn't run or load unless |
| 2339 | explicitly requested by name. for example: modprobe test_bitops. |
| 2340 | |
| 2341 | If unsure, say N. |
| 2342 | |
| 2343 | config TEST_VMALLOC |
| 2344 | tristate "Test module for stress/performance analysis of vmalloc allocator" |
| 2345 | default n |
| 2346 | depends on MMU |
| 2347 | depends on m |
| 2348 | help |
| 2349 | This builds the "test_vmalloc" module that should be used for |
| 2350 | stress and performance analysis. So, any new change for vmalloc |
| 2351 | subsystem can be evaluated from performance and stability point |
| 2352 | of view. |
| 2353 | |
| 2354 | If unsure, say N. |
| 2355 | |
| 2356 | config TEST_USER_COPY |
| 2357 | tristate "Test user/kernel boundary protections" |
| 2358 | depends on m |
| 2359 | help |
| 2360 | This builds the "test_user_copy" module that runs sanity checks |
| 2361 | on the copy_to/from_user infrastructure, making sure basic |
| 2362 | user/kernel boundary testing is working. If it fails to load, |
| 2363 | a regression has been detected in the user/kernel memory boundary |
| 2364 | protections. |
| 2365 | |
| 2366 | If unsure, say N. |
| 2367 | |
| 2368 | config TEST_BPF |
| 2369 | tristate "Test BPF filter functionality" |
| 2370 | depends on m && NET |
| 2371 | help |
| 2372 | This builds the "test_bpf" module that runs various test vectors |
| 2373 | against the BPF interpreter or BPF JIT compiler depending on the |
| 2374 | current setting. This is in particular useful for BPF JIT compiler |
| 2375 | development, but also to run regression tests against changes in |
| 2376 | the interpreter code. It also enables test stubs for eBPF maps and |
| 2377 | verifier used by user space verifier testsuite. |
| 2378 | |
| 2379 | If unsure, say N. |
| 2380 | |
| 2381 | config TEST_BLACKHOLE_DEV |
| 2382 | tristate "Test blackhole netdev functionality" |
| 2383 | depends on m && NET |
| 2384 | help |
| 2385 | This builds the "test_blackhole_dev" module that validates the |
| 2386 | data path through this blackhole netdev. |
| 2387 | |
| 2388 | If unsure, say N. |
| 2389 | |
| 2390 | config FIND_BIT_BENCHMARK |
| 2391 | tristate "Test find_bit functions" |
| 2392 | help |
| 2393 | This builds the "test_find_bit" module that measure find_*_bit() |
| 2394 | functions performance. |
| 2395 | |
| 2396 | If unsure, say N. |
| 2397 | |
| 2398 | config TEST_FIRMWARE |
| 2399 | tristate "Test firmware loading via userspace interface" |
| 2400 | depends on FW_LOADER |
| 2401 | help |
| 2402 | This builds the "test_firmware" module that creates a userspace |
| 2403 | interface for testing firmware loading. This can be used to |
| 2404 | control the triggering of firmware loading without needing an |
| 2405 | actual firmware-using device. The contents can be rechecked by |
| 2406 | userspace. |
| 2407 | |
| 2408 | If unsure, say N. |
| 2409 | |
| 2410 | config TEST_SYSCTL |
| 2411 | tristate "sysctl test driver" |
| 2412 | depends on PROC_SYSCTL |
| 2413 | help |
| 2414 | This builds the "test_sysctl" module. This driver enables to test the |
| 2415 | proc sysctl interfaces available to drivers safely without affecting |
| 2416 | production knobs which might alter system functionality. |
| 2417 | |
| 2418 | If unsure, say N. |
| 2419 | |
| 2420 | config BITFIELD_KUNIT |
| 2421 | tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS |
| 2422 | depends on KUNIT |
| 2423 | default KUNIT_ALL_TESTS |
| 2424 | help |
| 2425 | Enable this option to test the bitfield functions at boot. |
| 2426 | |
| 2427 | KUnit tests run during boot and output the results to the debug log |
| 2428 | in TAP format (http://testanything.org/). Only useful for kernel devs |
| 2429 | running the KUnit test harness, and not intended for inclusion into a |
| 2430 | production build. |
| 2431 | |
| 2432 | For more information on KUnit and unit tests in general please refer |
| 2433 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2434 | |
| 2435 | If unsure, say N. |
| 2436 | |
| 2437 | config HASH_KUNIT_TEST |
| 2438 | tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS |
| 2439 | depends on KUNIT |
| 2440 | default KUNIT_ALL_TESTS |
| 2441 | help |
| 2442 | Enable this option to test the kernel's string (<linux/stringhash.h>), and |
| 2443 | integer (<linux/hash.h>) hash functions on boot. |
| 2444 | |
| 2445 | KUnit tests run during boot and output the results to the debug log |
| 2446 | in TAP format (https://testanything.org/). Only useful for kernel devs |
| 2447 | running the KUnit test harness, and not intended for inclusion into a |
| 2448 | production build. |
| 2449 | |
| 2450 | For more information on KUnit and unit tests in general please refer |
| 2451 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2452 | |
| 2453 | This is intended to help people writing architecture-specific |
| 2454 | optimized versions. If unsure, say N. |
| 2455 | |
| 2456 | config RESOURCE_KUNIT_TEST |
| 2457 | tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS |
| 2458 | depends on KUNIT |
| 2459 | default KUNIT_ALL_TESTS |
| 2460 | help |
| 2461 | This builds the resource API unit test. |
| 2462 | Tests the logic of API provided by resource.c and ioport.h. |
| 2463 | For more information on KUnit and unit tests in general please refer |
| 2464 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2465 | |
| 2466 | If unsure, say N. |
| 2467 | |
| 2468 | config SYSCTL_KUNIT_TEST |
| 2469 | tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS |
| 2470 | depends on KUNIT |
| 2471 | default KUNIT_ALL_TESTS |
| 2472 | help |
| 2473 | This builds the proc sysctl unit test, which runs on boot. |
| 2474 | Tests the API contract and implementation correctness of sysctl. |
| 2475 | For more information on KUnit and unit tests in general please refer |
| 2476 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2477 | |
| 2478 | If unsure, say N. |
| 2479 | |
| 2480 | config LIST_KUNIT_TEST |
| 2481 | tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS |
| 2482 | depends on KUNIT |
| 2483 | default KUNIT_ALL_TESTS |
| 2484 | help |
| 2485 | This builds the linked list KUnit test suite. |
| 2486 | It tests that the API and basic functionality of the list_head type |
| 2487 | and associated macros. |
| 2488 | |
| 2489 | KUnit tests run during boot and output the results to the debug log |
| 2490 | in TAP format (https://testanything.org/). Only useful for kernel devs |
| 2491 | running the KUnit test harness, and not intended for inclusion into a |
| 2492 | production build. |
| 2493 | |
| 2494 | For more information on KUnit and unit tests in general please refer |
| 2495 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2496 | |
| 2497 | If unsure, say N. |
| 2498 | |
| 2499 | config LINEAR_RANGES_TEST |
| 2500 | tristate "KUnit test for linear_ranges" |
| 2501 | depends on KUNIT |
| 2502 | select LINEAR_RANGES |
| 2503 | help |
| 2504 | This builds the linear_ranges unit test, which runs on boot. |
| 2505 | Tests the linear_ranges logic correctness. |
| 2506 | For more information on KUnit and unit tests in general please refer |
| 2507 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2508 | |
| 2509 | If unsure, say N. |
| 2510 | |
| 2511 | config CMDLINE_KUNIT_TEST |
| 2512 | tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS |
| 2513 | depends on KUNIT |
| 2514 | default KUNIT_ALL_TESTS |
| 2515 | help |
| 2516 | This builds the cmdline API unit test. |
| 2517 | Tests the logic of API provided by cmdline.c. |
| 2518 | For more information on KUnit and unit tests in general please refer |
| 2519 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2520 | |
| 2521 | If unsure, say N. |
| 2522 | |
| 2523 | config BITS_TEST |
| 2524 | tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS |
| 2525 | depends on KUNIT |
| 2526 | default KUNIT_ALL_TESTS |
| 2527 | help |
| 2528 | This builds the bits unit test. |
| 2529 | Tests the logic of macros defined in bits.h. |
| 2530 | For more information on KUnit and unit tests in general please refer |
| 2531 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2532 | |
| 2533 | If unsure, say N. |
| 2534 | |
| 2535 | config SLUB_KUNIT_TEST |
| 2536 | tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS |
| 2537 | depends on SLUB_DEBUG && KUNIT |
| 2538 | default KUNIT_ALL_TESTS |
| 2539 | help |
| 2540 | This builds SLUB allocator unit test. |
| 2541 | Tests SLUB cache debugging functionality. |
| 2542 | For more information on KUnit and unit tests in general please refer |
| 2543 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2544 | |
| 2545 | If unsure, say N. |
| 2546 | |
| 2547 | config RATIONAL_KUNIT_TEST |
| 2548 | tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS |
| 2549 | depends on KUNIT && RATIONAL |
| 2550 | default KUNIT_ALL_TESTS |
| 2551 | help |
| 2552 | This builds the rational math unit test. |
| 2553 | For more information on KUnit and unit tests in general please refer |
| 2554 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2555 | |
| 2556 | If unsure, say N. |
| 2557 | |
| 2558 | config MEMCPY_KUNIT_TEST |
| 2559 | tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS |
| 2560 | depends on KUNIT |
| 2561 | default KUNIT_ALL_TESTS |
| 2562 | help |
| 2563 | Builds unit tests for memcpy(), memmove(), and memset() functions. |
| 2564 | For more information on KUnit and unit tests in general please refer |
| 2565 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2566 | |
| 2567 | If unsure, say N. |
| 2568 | |
| 2569 | config IS_SIGNED_TYPE_KUNIT_TEST |
| 2570 | tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS |
| 2571 | depends on KUNIT |
| 2572 | default KUNIT_ALL_TESTS |
| 2573 | help |
| 2574 | Builds unit tests for the is_signed_type() macro. |
| 2575 | |
| 2576 | For more information on KUnit and unit tests in general please refer |
| 2577 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2578 | |
| 2579 | If unsure, say N. |
| 2580 | |
| 2581 | config OVERFLOW_KUNIT_TEST |
| 2582 | tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS |
| 2583 | depends on KUNIT |
| 2584 | default KUNIT_ALL_TESTS |
| 2585 | help |
| 2586 | Builds unit tests for the check_*_overflow(), size_*(), allocation, and |
| 2587 | related functions. |
| 2588 | |
| 2589 | For more information on KUnit and unit tests in general please refer |
| 2590 | to the KUnit documentation in Documentation/dev-tools/kunit/. |
| 2591 | |
| 2592 | If unsure, say N. |
| 2593 | |
| 2594 | config STACKINIT_KUNIT_TEST |
| 2595 | tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS |
| 2596 | depends on KUNIT |
| 2597 | default KUNIT_ALL_TESTS |
| 2598 | help |
| 2599 | Test if the kernel is zero-initializing stack variables and |
| 2600 | padding. Coverage is controlled by compiler flags, |
| 2601 | CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO, |
| 2602 | CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF, |
| 2603 | or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL. |
| 2604 | |
| 2605 | config FORTIFY_KUNIT_TEST |
| 2606 | tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS |
| 2607 | depends on KUNIT && FORTIFY_SOURCE |
| 2608 | default KUNIT_ALL_TESTS |
| 2609 | help |
| 2610 | Builds unit tests for checking internals of FORTIFY_SOURCE as used |
| 2611 | by the str*() and mem*() family of functions. For testing runtime |
| 2612 | traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests. |
| 2613 | |
| 2614 | config HW_BREAKPOINT_KUNIT_TEST |
| 2615 | bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS |
| 2616 | depends on HAVE_HW_BREAKPOINT |
| 2617 | depends on KUNIT=y |
| 2618 | default KUNIT_ALL_TESTS |
| 2619 | help |
| 2620 | Tests for hw_breakpoint constraints accounting. |
| 2621 | |
| 2622 | If unsure, say N. |
| 2623 | |
| 2624 | config STRSCPY_KUNIT_TEST |
| 2625 | tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS |
| 2626 | depends on KUNIT |
| 2627 | default KUNIT_ALL_TESTS |
| 2628 | |
| 2629 | config SIPHASH_KUNIT_TEST |
| 2630 | tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS |
| 2631 | depends on KUNIT |
| 2632 | default KUNIT_ALL_TESTS |
| 2633 | help |
| 2634 | Enable this option to test the kernel's siphash (<linux/siphash.h>) hash |
| 2635 | functions on boot (or module load). |
| 2636 | |
| 2637 | This is intended to help people writing architecture-specific |
| 2638 | optimized versions. If unsure, say N. |
| 2639 | |
| 2640 | config TEST_UDELAY |
| 2641 | tristate "udelay test driver" |
| 2642 | help |
| 2643 | This builds the "udelay_test" module that helps to make sure |
| 2644 | that udelay() is working properly. |
| 2645 | |
| 2646 | If unsure, say N. |
| 2647 | |
| 2648 | config TEST_STATIC_KEYS |
| 2649 | tristate "Test static keys" |
| 2650 | depends on m |
| 2651 | help |
| 2652 | Test the static key interfaces. |
| 2653 | |
| 2654 | If unsure, say N. |
| 2655 | |
| 2656 | config TEST_DYNAMIC_DEBUG |
| 2657 | tristate "Test DYNAMIC_DEBUG" |
| 2658 | depends on DYNAMIC_DEBUG |
| 2659 | help |
| 2660 | This module registers a tracer callback to count enabled |
| 2661 | pr_debugs in a 'do_debugging' function, then alters their |
| 2662 | enablements, calls the function, and compares counts. |
| 2663 | |
| 2664 | If unsure, say N. |
| 2665 | |
| 2666 | config TEST_KMOD |
| 2667 | tristate "kmod stress tester" |
| 2668 | depends on m |
| 2669 | depends on NETDEVICES && NET_CORE && INET # for TUN |
| 2670 | depends on BLOCK |
| 2671 | depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS |
| 2672 | select TEST_LKM |
| 2673 | select XFS_FS |
| 2674 | select TUN |
| 2675 | select BTRFS_FS |
| 2676 | help |
| 2677 | Test the kernel's module loading mechanism: kmod. kmod implements |
| 2678 | support to load modules using the Linux kernel's usermode helper. |
| 2679 | This test provides a series of tests against kmod. |
| 2680 | |
| 2681 | Although technically you can either build test_kmod as a module or |
| 2682 | into the kernel we disallow building it into the kernel since |
| 2683 | it stress tests request_module() and this will very likely cause |
| 2684 | some issues by taking over precious threads available from other |
| 2685 | module load requests, ultimately this could be fatal. |
| 2686 | |
| 2687 | To run tests run: |
| 2688 | |
| 2689 | tools/testing/selftests/kmod/kmod.sh --help |
| 2690 | |
| 2691 | If unsure, say N. |
| 2692 | |
| 2693 | config TEST_DEBUG_VIRTUAL |
| 2694 | tristate "Test CONFIG_DEBUG_VIRTUAL feature" |
| 2695 | depends on DEBUG_VIRTUAL |
| 2696 | help |
| 2697 | Test the kernel's ability to detect incorrect calls to |
| 2698 | virt_to_phys() done against the non-linear part of the |
| 2699 | kernel's virtual address map. |
| 2700 | |
| 2701 | If unsure, say N. |
| 2702 | |
| 2703 | config TEST_MEMCAT_P |
| 2704 | tristate "Test memcat_p() helper function" |
| 2705 | help |
| 2706 | Test the memcat_p() helper for correctly merging two |
| 2707 | pointer arrays together. |
| 2708 | |
| 2709 | If unsure, say N. |
| 2710 | |
| 2711 | config TEST_LIVEPATCH |
| 2712 | tristate "Test livepatching" |
| 2713 | default n |
| 2714 | depends on DYNAMIC_DEBUG |
| 2715 | depends on LIVEPATCH |
| 2716 | depends on m |
| 2717 | help |
| 2718 | Test kernel livepatching features for correctness. The tests will |
| 2719 | load test modules that will be livepatched in various scenarios. |
| 2720 | |
| 2721 | To run all the livepatching tests: |
| 2722 | |
| 2723 | make -C tools/testing/selftests TARGETS=livepatch run_tests |
| 2724 | |
| 2725 | Alternatively, individual tests may be invoked: |
| 2726 | |
| 2727 | tools/testing/selftests/livepatch/test-callbacks.sh |
| 2728 | tools/testing/selftests/livepatch/test-livepatch.sh |
| 2729 | tools/testing/selftests/livepatch/test-shadow-vars.sh |
| 2730 | |
| 2731 | If unsure, say N. |
| 2732 | |
| 2733 | config TEST_OBJAGG |
| 2734 | tristate "Perform selftest on object aggreration manager" |
| 2735 | default n |
| 2736 | depends on OBJAGG |
| 2737 | help |
| 2738 | Enable this option to test object aggregation manager on boot |
| 2739 | (or module load). |
| 2740 | |
| 2741 | config TEST_MEMINIT |
| 2742 | tristate "Test heap/page initialization" |
| 2743 | help |
| 2744 | Test if the kernel is zero-initializing heap and page allocations. |
| 2745 | This can be useful to test init_on_alloc and init_on_free features. |
| 2746 | |
| 2747 | If unsure, say N. |
| 2748 | |
| 2749 | config TEST_HMM |
| 2750 | tristate "Test HMM (Heterogeneous Memory Management)" |
| 2751 | depends on TRANSPARENT_HUGEPAGE |
| 2752 | depends on DEVICE_PRIVATE |
| 2753 | select HMM_MIRROR |
| 2754 | select MMU_NOTIFIER |
| 2755 | help |
| 2756 | This is a pseudo device driver solely for testing HMM. |
| 2757 | Say M here if you want to build the HMM test module. |
| 2758 | Doing so will allow you to run tools/testing/selftest/vm/hmm-tests. |
| 2759 | |
| 2760 | If unsure, say N. |
| 2761 | |
| 2762 | config TEST_FREE_PAGES |
| 2763 | tristate "Test freeing pages" |
| 2764 | help |
| 2765 | Test that a memory leak does not occur due to a race between |
| 2766 | freeing a block of pages and a speculative page reference. |
| 2767 | Loading this module is safe if your kernel has the bug fixed. |
| 2768 | If the bug is not fixed, it will leak gigabytes of memory and |
| 2769 | probably OOM your system. |
| 2770 | |
| 2771 | config TEST_FPU |
| 2772 | tristate "Test floating point operations in kernel space" |
| 2773 | depends on X86 && !KCOV_INSTRUMENT_ALL |
| 2774 | help |
| 2775 | Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu |
| 2776 | which will trigger a sequence of floating point operations. This is used |
| 2777 | for self-testing floating point control register setting in |
| 2778 | kernel_fpu_begin(). |
| 2779 | |
| 2780 | If unsure, say N. |
| 2781 | |
| 2782 | config TEST_CLOCKSOURCE_WATCHDOG |
| 2783 | tristate "Test clocksource watchdog in kernel space" |
| 2784 | depends on CLOCKSOURCE_WATCHDOG |
| 2785 | help |
| 2786 | Enable this option to create a kernel module that will trigger |
| 2787 | a test of the clocksource watchdog. This module may be loaded |
| 2788 | via modprobe or insmod in which case it will run upon being |
| 2789 | loaded, or it may be built in, in which case it will run |
| 2790 | shortly after boot. |
| 2791 | |
| 2792 | If unsure, say N. |
| 2793 | |
| 2794 | endif # RUNTIME_TESTING_MENU |
| 2795 | |
| 2796 | config ARCH_USE_MEMTEST |
| 2797 | bool |
| 2798 | help |
| 2799 | An architecture should select this when it uses early_memtest() |
| 2800 | during boot process. |
| 2801 | |
| 2802 | config MEMTEST |
| 2803 | bool "Memtest" |
| 2804 | depends on ARCH_USE_MEMTEST |
| 2805 | help |
| 2806 | This option adds a kernel parameter 'memtest', which allows memtest |
| 2807 | to be set and executed. |
| 2808 | memtest=0, mean disabled; -- default |
| 2809 | memtest=1, mean do 1 test pattern; |
| 2810 | ... |
| 2811 | memtest=17, mean do 17 test patterns. |
| 2812 | If you are unsure how to answer this question, answer N. |
| 2813 | |
| 2814 | |
| 2815 | |
| 2816 | config HYPERV_TESTING |
| 2817 | bool "Microsoft Hyper-V driver testing" |
| 2818 | default n |
| 2819 | depends on HYPERV && DEBUG_FS |
| 2820 | help |
| 2821 | Select this option to enable Hyper-V vmbus testing. |
| 2822 | |
| 2823 | endmenu # "Kernel Testing and Coverage" |
| 2824 | |
| 2825 | menu "Rust hacking" |
| 2826 | |
| 2827 | config RUST_DEBUG_ASSERTIONS |
| 2828 | bool "Debug assertions" |
| 2829 | depends on RUST |
| 2830 | help |
| 2831 | Enables rustc's `-Cdebug-assertions` codegen option. |
| 2832 | |
| 2833 | This flag lets you turn `cfg(debug_assertions)` conditional |
| 2834 | compilation on or off. This can be used to enable extra debugging |
| 2835 | code in development but not in production. For example, it controls |
| 2836 | the behavior of the standard library's `debug_assert!` macro. |
| 2837 | |
| 2838 | Note that this will apply to all Rust code, including `core`. |
| 2839 | |
| 2840 | If unsure, say N. |
| 2841 | |
| 2842 | config RUST_OVERFLOW_CHECKS |
| 2843 | bool "Overflow checks" |
| 2844 | default y |
| 2845 | depends on RUST |
| 2846 | help |
| 2847 | Enables rustc's `-Coverflow-checks` codegen option. |
| 2848 | |
| 2849 | This flag allows you to control the behavior of runtime integer |
| 2850 | overflow. When overflow-checks are enabled, a Rust panic will occur |
| 2851 | on overflow. |
| 2852 | |
| 2853 | Note that this will apply to all Rust code, including `core`. |
| 2854 | |
| 2855 | If unsure, say Y. |
| 2856 | |
| 2857 | config RUST_BUILD_ASSERT_ALLOW |
| 2858 | bool "Allow unoptimized build-time assertions" |
| 2859 | depends on RUST |
| 2860 | help |
| 2861 | Controls how are `build_error!` and `build_assert!` handled during build. |
| 2862 | |
| 2863 | If calls to them exist in the binary, it may indicate a violated invariant |
| 2864 | or that the optimizer failed to verify the invariant during compilation. |
| 2865 | |
| 2866 | This should not happen, thus by default the build is aborted. However, |
| 2867 | as an escape hatch, you can choose Y here to ignore them during build |
| 2868 | and let the check be carried at runtime (with `panic!` being called if |
| 2869 | the check fails). |
| 2870 | |
| 2871 | If unsure, say N. |
| 2872 | |
| 2873 | endmenu # "Rust" |
| 2874 | |
| 2875 | source "Documentation/Kconfig" |
| 2876 | |
| 2877 | endmenu # Kernel hacking |