Kconfig.debug 45 KB

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  1. config PRINTK_TIME
  2. bool "Show timing information on printks"
  3. depends on PRINTK
  4. help
  5. Selecting this option causes timing information to be
  6. included in printk output. This allows you to measure
  7. the interval between kernel operations, including bootup
  8. operations. This is useful for identifying long delays
  9. in kernel startup. Or add printk.time=1 at boot-time.
  10. See Documentation/kernel-parameters.txt
  11. config DEFAULT_MESSAGE_LOGLEVEL
  12. int "Default message log level (1-7)"
  13. range 1 7
  14. default "4"
  15. help
  16. Default log level for printk statements with no specified priority.
  17. This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
  18. that are auditing their logs closely may want to set it to a lower
  19. priority.
  20. config ENABLE_WARN_DEPRECATED
  21. bool "Enable __deprecated logic"
  22. default y
  23. help
  24. Enable the __deprecated logic in the kernel build.
  25. Disable this to suppress the "warning: 'foo' is deprecated
  26. (declared at kernel/power/somefile.c:1234)" messages.
  27. config ENABLE_MUST_CHECK
  28. bool "Enable __must_check logic"
  29. default y
  30. help
  31. Enable the __must_check logic in the kernel build. Disable this to
  32. suppress the "warning: ignoring return value of 'foo', declared with
  33. attribute warn_unused_result" messages.
  34. config FRAME_WARN
  35. int "Warn for stack frames larger than (needs gcc 4.4)"
  36. range 0 8192
  37. default 1024 if !64BIT
  38. default 2048 if 64BIT
  39. help
  40. Tell gcc to warn at build time for stack frames larger than this.
  41. Setting this too low will cause a lot of warnings.
  42. Setting it to 0 disables the warning.
  43. Requires gcc 4.4
  44. config MAGIC_SYSRQ
  45. bool "Magic SysRq key"
  46. depends on !UML
  47. help
  48. If you say Y here, you will have some control over the system even
  49. if the system crashes for example during kernel debugging (e.g., you
  50. will be able to flush the buffer cache to disk, reboot the system
  51. immediately or dump some status information). This is accomplished
  52. by pressing various keys while holding SysRq (Alt+PrintScreen). It
  53. also works on a serial console (on PC hardware at least), if you
  54. send a BREAK and then within 5 seconds a command keypress. The
  55. keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  56. unless you really know what this hack does.
  57. config STRIP_ASM_SYMS
  58. bool "Strip assembler-generated symbols during link"
  59. default n
  60. help
  61. Strip internal assembler-generated symbols during a link (symbols
  62. that look like '.Lxxx') so they don't pollute the output of
  63. get_wchan() and suchlike.
  64. config UNUSED_SYMBOLS
  65. bool "Enable unused/obsolete exported symbols"
  66. default y if X86
  67. help
  68. Unused but exported symbols make the kernel needlessly bigger. For
  69. that reason most of these unused exports will soon be removed. This
  70. option is provided temporarily to provide a transition period in case
  71. some external kernel module needs one of these symbols anyway. If you
  72. encounter such a case in your module, consider if you are actually
  73. using the right API. (rationale: since nobody in the kernel is using
  74. this in a module, there is a pretty good chance it's actually the
  75. wrong interface to use). If you really need the symbol, please send a
  76. mail to the linux kernel mailing list mentioning the symbol and why
  77. you really need it, and what the merge plan to the mainline kernel for
  78. your module is.
  79. config DEBUG_FS
  80. bool "Debug Filesystem"
  81. help
  82. debugfs is a virtual file system that kernel developers use to put
  83. debugging files into. Enable this option to be able to read and
  84. write to these files.
  85. For detailed documentation on the debugfs API, see
  86. Documentation/DocBook/filesystems.
  87. If unsure, say N.
  88. config HEADERS_CHECK
  89. bool "Run 'make headers_check' when building vmlinux"
  90. depends on !UML
  91. help
  92. This option will extract the user-visible kernel headers whenever
  93. building the kernel, and will run basic sanity checks on them to
  94. ensure that exported files do not attempt to include files which
  95. were not exported, etc.
  96. If you're making modifications to header files which are
  97. relevant for userspace, say 'Y', and check the headers
  98. exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
  99. your build tree), to make sure they're suitable.
  100. config DEBUG_SECTION_MISMATCH
  101. bool "Enable full Section mismatch analysis"
  102. help
  103. The section mismatch analysis checks if there are illegal
  104. references from one section to another section.
  105. During linktime or runtime, some sections are dropped;
  106. any use of code/data previously in these sections would
  107. most likely result in an oops.
  108. In the code, functions and variables are annotated with
  109. __init, __devinit, etc. (see the full list in include/linux/init.h),
  110. which results in the code/data being placed in specific sections.
  111. The section mismatch analysis is always performed after a full
  112. kernel build, and enabling this option causes the following
  113. additional steps to occur:
  114. - Add the option -fno-inline-functions-called-once to gcc commands.
  115. When inlining a function annotated with __init in a non-init
  116. function, we would lose the section information and thus
  117. the analysis would not catch the illegal reference.
  118. This option tells gcc to inline less (but it does result in
  119. a larger kernel).
  120. - Run the section mismatch analysis for each module/built-in.o file.
  121. When we run the section mismatch analysis on vmlinux.o, we
  122. lose valueble information about where the mismatch was
  123. introduced.
  124. Running the analysis for each module/built-in.o file
  125. tells where the mismatch happens much closer to the
  126. source. The drawback is that the same mismatch is
  127. reported at least twice.
  128. - Enable verbose reporting from modpost in order to help resolve
  129. the section mismatches that are reported.
  130. config DEBUG_KERNEL
  131. bool "Kernel debugging"
  132. help
  133. Say Y here if you are developing drivers or trying to debug and
  134. identify kernel problems.
  135. config DEBUG_SHIRQ
  136. bool "Debug shared IRQ handlers"
  137. depends on DEBUG_KERNEL && GENERIC_HARDIRQS
  138. help
  139. Enable this to generate a spurious interrupt as soon as a shared
  140. interrupt handler is registered, and just before one is deregistered.
  141. Drivers ought to be able to handle interrupts coming in at those
  142. points; some don't and need to be caught.
  143. config LOCKUP_DETECTOR
  144. bool "Detect Hard and Soft Lockups"
  145. depends on DEBUG_KERNEL && !S390
  146. help
  147. Say Y here to enable the kernel to act as a watchdog to detect
  148. hard and soft lockups.
  149. Softlockups are bugs that cause the kernel to loop in kernel
  150. mode for more than 20 seconds, without giving other tasks a
  151. chance to run. The current stack trace is displayed upon
  152. detection and the system will stay locked up.
  153. Hardlockups are bugs that cause the CPU to loop in kernel mode
  154. for more than 10 seconds, without letting other interrupts have a
  155. chance to run. The current stack trace is displayed upon detection
  156. and the system will stay locked up.
  157. The overhead should be minimal. A periodic hrtimer runs to
  158. generate interrupts and kick the watchdog task every 4 seconds.
  159. An NMI is generated every 10 seconds or so to check for hardlockups.
  160. The frequency of hrtimer and NMI events and the soft and hard lockup
  161. thresholds can be controlled through the sysctl watchdog_thresh.
  162. config HARDLOCKUP_DETECTOR
  163. def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
  164. !HAVE_NMI_WATCHDOG
  165. config BOOTPARAM_HARDLOCKUP_PANIC
  166. bool "Panic (Reboot) On Hard Lockups"
  167. depends on LOCKUP_DETECTOR
  168. help
  169. Say Y here to enable the kernel to panic on "hard lockups",
  170. which are bugs that cause the kernel to loop in kernel
  171. mode with interrupts disabled for more than 10 seconds (configurable
  172. using the watchdog_thresh sysctl).
  173. Say N if unsure.
  174. config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
  175. int
  176. depends on LOCKUP_DETECTOR
  177. range 0 1
  178. default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
  179. default 1 if BOOTPARAM_HARDLOCKUP_PANIC
  180. config BOOTPARAM_SOFTLOCKUP_PANIC
  181. bool "Panic (Reboot) On Soft Lockups"
  182. depends on LOCKUP_DETECTOR
  183. help
  184. Say Y here to enable the kernel to panic on "soft lockups",
  185. which are bugs that cause the kernel to loop in kernel
  186. mode for more than 20 seconds (configurable using the watchdog_thresh
  187. sysctl), without giving other tasks a chance to run.
  188. The panic can be used in combination with panic_timeout,
  189. to cause the system to reboot automatically after a
  190. lockup has been detected. This feature is useful for
  191. high-availability systems that have uptime guarantees and
  192. where a lockup must be resolved ASAP.
  193. Say N if unsure.
  194. config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
  195. int
  196. depends on LOCKUP_DETECTOR
  197. range 0 1
  198. default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
  199. default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
  200. config DETECT_HUNG_TASK
  201. bool "Detect Hung Tasks"
  202. depends on DEBUG_KERNEL
  203. default LOCKUP_DETECTOR
  204. help
  205. Say Y here to enable the kernel to detect "hung tasks",
  206. which are bugs that cause the task to be stuck in
  207. uninterruptible "D" state indefinitiley.
  208. When a hung task is detected, the kernel will print the
  209. current stack trace (which you should report), but the
  210. task will stay in uninterruptible state. If lockdep is
  211. enabled then all held locks will also be reported. This
  212. feature has negligible overhead.
  213. config DEFAULT_HUNG_TASK_TIMEOUT
  214. int "Default timeout for hung task detection (in seconds)"
  215. depends on DETECT_HUNG_TASK
  216. default 120
  217. help
  218. This option controls the default timeout (in seconds) used
  219. to determine when a task has become non-responsive and should
  220. be considered hung.
  221. It can be adjusted at runtime via the kernel.hung_task_timeout_secs
  222. sysctl or by writing a value to
  223. /proc/sys/kernel/hung_task_timeout_secs.
  224. A timeout of 0 disables the check. The default is two minutes.
  225. Keeping the default should be fine in most cases.
  226. config BOOTPARAM_HUNG_TASK_PANIC
  227. bool "Panic (Reboot) On Hung Tasks"
  228. depends on DETECT_HUNG_TASK
  229. help
  230. Say Y here to enable the kernel to panic on "hung tasks",
  231. which are bugs that cause the kernel to leave a task stuck
  232. in uninterruptible "D" state.
  233. The panic can be used in combination with panic_timeout,
  234. to cause the system to reboot automatically after a
  235. hung task has been detected. This feature is useful for
  236. high-availability systems that have uptime guarantees and
  237. where a hung tasks must be resolved ASAP.
  238. Say N if unsure.
  239. config BOOTPARAM_HUNG_TASK_PANIC_VALUE
  240. int
  241. depends on DETECT_HUNG_TASK
  242. range 0 1
  243. default 0 if !BOOTPARAM_HUNG_TASK_PANIC
  244. default 1 if BOOTPARAM_HUNG_TASK_PANIC
  245. config SCHED_DEBUG
  246. bool "Collect scheduler debugging info"
  247. depends on DEBUG_KERNEL && PROC_FS
  248. default y
  249. help
  250. If you say Y here, the /proc/sched_debug file will be provided
  251. that can help debug the scheduler. The runtime overhead of this
  252. option is minimal.
  253. config SYSRQ_SCHED_DEBUG
  254. bool "Print scheduling debugging info from sysrq-trigger"
  255. depends on SCHED_DEBUG
  256. default y
  257. help
  258. If you say Y here, the "show-task-states(T)" and
  259. "show-blocked-tasks(W)" sysrq-triggers will print additional
  260. scheduling statistics.
  261. config SCHEDSTATS
  262. bool "Collect scheduler statistics"
  263. depends on DEBUG_KERNEL && PROC_FS
  264. help
  265. If you say Y here, additional code will be inserted into the
  266. scheduler and related routines to collect statistics about
  267. scheduler behavior and provide them in /proc/schedstat. These
  268. stats may be useful for both tuning and debugging the scheduler
  269. If you aren't debugging the scheduler or trying to tune a specific
  270. application, you can say N to avoid the very slight overhead
  271. this adds.
  272. config DEBUG_OBJECTS
  273. bool "Debug object operations"
  274. depends on DEBUG_KERNEL
  275. help
  276. If you say Y here, additional code will be inserted into the
  277. kernel to track the life time of various objects and validate
  278. the operations on those objects.
  279. config DEBUG_OBJECTS_SELFTEST
  280. bool "Debug objects selftest"
  281. depends on DEBUG_OBJECTS
  282. help
  283. This enables the selftest of the object debug code.
  284. config DEBUG_OBJECTS_FREE
  285. bool "Debug objects in freed memory"
  286. depends on DEBUG_OBJECTS
  287. help
  288. This enables checks whether a k/v free operation frees an area
  289. which contains an object which has not been deactivated
  290. properly. This can make kmalloc/kfree-intensive workloads
  291. much slower.
  292. config DEBUG_OBJECTS_TIMERS
  293. bool "Debug timer objects"
  294. depends on DEBUG_OBJECTS
  295. help
  296. If you say Y here, additional code will be inserted into the
  297. timer routines to track the life time of timer objects and
  298. validate the timer operations.
  299. config DEBUG_OBJECTS_WORK
  300. bool "Debug work objects"
  301. depends on DEBUG_OBJECTS
  302. help
  303. If you say Y here, additional code will be inserted into the
  304. work queue routines to track the life time of work objects and
  305. validate the work operations.
  306. config DEBUG_OBJECTS_RCU_HEAD
  307. bool "Debug RCU callbacks objects"
  308. depends on DEBUG_OBJECTS
  309. help
  310. Enable this to turn on debugging of RCU list heads (call_rcu() usage).
  311. config DEBUG_OBJECTS_PERCPU_COUNTER
  312. bool "Debug percpu counter objects"
  313. depends on DEBUG_OBJECTS
  314. help
  315. If you say Y here, additional code will be inserted into the
  316. percpu counter routines to track the life time of percpu counter
  317. objects and validate the percpu counter operations.
  318. config DEBUG_OBJECTS_ENABLE_DEFAULT
  319. int "debug_objects bootup default value (0-1)"
  320. range 0 1
  321. default "1"
  322. depends on DEBUG_OBJECTS
  323. help
  324. Debug objects boot parameter default value
  325. config DEBUG_SLAB
  326. bool "Debug slab memory allocations"
  327. depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
  328. help
  329. Say Y here to have the kernel do limited verification on memory
  330. allocation as well as poisoning memory on free to catch use of freed
  331. memory. This can make kmalloc/kfree-intensive workloads much slower.
  332. config DEBUG_SLAB_LEAK
  333. bool "Memory leak debugging"
  334. depends on DEBUG_SLAB
  335. config SLUB_DEBUG_ON
  336. bool "SLUB debugging on by default"
  337. depends on SLUB && SLUB_DEBUG && !KMEMCHECK
  338. default n
  339. help
  340. Boot with debugging on by default. SLUB boots by default with
  341. the runtime debug capabilities switched off. Enabling this is
  342. equivalent to specifying the "slub_debug" parameter on boot.
  343. There is no support for more fine grained debug control like
  344. possible with slub_debug=xxx. SLUB debugging may be switched
  345. off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
  346. "slub_debug=-".
  347. config SLUB_STATS
  348. default n
  349. bool "Enable SLUB performance statistics"
  350. depends on SLUB && SYSFS
  351. help
  352. SLUB statistics are useful to debug SLUBs allocation behavior in
  353. order find ways to optimize the allocator. This should never be
  354. enabled for production use since keeping statistics slows down
  355. the allocator by a few percentage points. The slabinfo command
  356. supports the determination of the most active slabs to figure
  357. out which slabs are relevant to a particular load.
  358. Try running: slabinfo -DA
  359. config DEBUG_KMEMLEAK
  360. bool "Kernel memory leak detector"
  361. depends on DEBUG_KERNEL && EXPERIMENTAL && \
  362. (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE)
  363. select DEBUG_FS
  364. select STACKTRACE if STACKTRACE_SUPPORT
  365. select KALLSYMS
  366. select CRC32
  367. help
  368. Say Y here if you want to enable the memory leak
  369. detector. The memory allocation/freeing is traced in a way
  370. similar to the Boehm's conservative garbage collector, the
  371. difference being that the orphan objects are not freed but
  372. only shown in /sys/kernel/debug/kmemleak. Enabling this
  373. feature will introduce an overhead to memory
  374. allocations. See Documentation/kmemleak.txt for more
  375. details.
  376. Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
  377. of finding leaks due to the slab objects poisoning.
  378. In order to access the kmemleak file, debugfs needs to be
  379. mounted (usually at /sys/kernel/debug).
  380. config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
  381. int "Maximum kmemleak early log entries"
  382. depends on DEBUG_KMEMLEAK
  383. range 200 40000
  384. default 800
  385. help
  386. Kmemleak must track all the memory allocations to avoid
  387. reporting false positives. Since memory may be allocated or
  388. freed before kmemleak is initialised, an early log buffer is
  389. used to store these actions. If kmemleak reports "early log
  390. buffer exceeded", please increase this value.
  391. config DEBUG_KMEMLEAK_TEST
  392. tristate "Simple test for the kernel memory leak detector"
  393. depends on DEBUG_KMEMLEAK && m
  394. help
  395. This option enables a module that explicitly leaks memory.
  396. If unsure, say N.
  397. config DEBUG_KMEMLEAK_DEFAULT_OFF
  398. bool "Default kmemleak to off"
  399. depends on DEBUG_KMEMLEAK
  400. help
  401. Say Y here to disable kmemleak by default. It can then be enabled
  402. on the command line via kmemleak=on.
  403. config DEBUG_PREEMPT
  404. bool "Debug preemptible kernel"
  405. depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
  406. default y
  407. help
  408. If you say Y here then the kernel will use a debug variant of the
  409. commonly used smp_processor_id() function and will print warnings
  410. if kernel code uses it in a preemption-unsafe way. Also, the kernel
  411. will detect preemption count underflows.
  412. config DEBUG_RT_MUTEXES
  413. bool "RT Mutex debugging, deadlock detection"
  414. depends on DEBUG_KERNEL && RT_MUTEXES
  415. help
  416. This allows rt mutex semantics violations and rt mutex related
  417. deadlocks (lockups) to be detected and reported automatically.
  418. config DEBUG_PI_LIST
  419. bool
  420. default y
  421. depends on DEBUG_RT_MUTEXES
  422. config RT_MUTEX_TESTER
  423. bool "Built-in scriptable tester for rt-mutexes"
  424. depends on DEBUG_KERNEL && RT_MUTEXES
  425. help
  426. This option enables a rt-mutex tester.
  427. config DEBUG_SPINLOCK
  428. bool "Spinlock and rw-lock debugging: basic checks"
  429. depends on DEBUG_KERNEL
  430. select UNINLINE_SPIN_UNLOCK
  431. help
  432. Say Y here and build SMP to catch missing spinlock initialization
  433. and certain other kinds of spinlock errors commonly made. This is
  434. best used in conjunction with the NMI watchdog so that spinlock
  435. deadlocks are also debuggable.
  436. config DEBUG_MUTEXES
  437. bool "Mutex debugging: basic checks"
  438. depends on DEBUG_KERNEL
  439. help
  440. This feature allows mutex semantics violations to be detected and
  441. reported.
  442. config DEBUG_LOCK_ALLOC
  443. bool "Lock debugging: detect incorrect freeing of live locks"
  444. depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
  445. select DEBUG_SPINLOCK
  446. select DEBUG_MUTEXES
  447. select LOCKDEP
  448. help
  449. This feature will check whether any held lock (spinlock, rwlock,
  450. mutex or rwsem) is incorrectly freed by the kernel, via any of the
  451. memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
  452. vfree(), etc.), whether a live lock is incorrectly reinitialized via
  453. spin_lock_init()/mutex_init()/etc., or whether there is any lock
  454. held during task exit.
  455. config PROVE_LOCKING
  456. bool "Lock debugging: prove locking correctness"
  457. depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
  458. select LOCKDEP
  459. select DEBUG_SPINLOCK
  460. select DEBUG_MUTEXES
  461. select DEBUG_LOCK_ALLOC
  462. select TRACE_IRQFLAGS
  463. default n
  464. help
  465. This feature enables the kernel to prove that all locking
  466. that occurs in the kernel runtime is mathematically
  467. correct: that under no circumstance could an arbitrary (and
  468. not yet triggered) combination of observed locking
  469. sequences (on an arbitrary number of CPUs, running an
  470. arbitrary number of tasks and interrupt contexts) cause a
  471. deadlock.
  472. In short, this feature enables the kernel to report locking
  473. related deadlocks before they actually occur.
  474. The proof does not depend on how hard and complex a
  475. deadlock scenario would be to trigger: how many
  476. participant CPUs, tasks and irq-contexts would be needed
  477. for it to trigger. The proof also does not depend on
  478. timing: if a race and a resulting deadlock is possible
  479. theoretically (no matter how unlikely the race scenario
  480. is), it will be proven so and will immediately be
  481. reported by the kernel (once the event is observed that
  482. makes the deadlock theoretically possible).
  483. If a deadlock is impossible (i.e. the locking rules, as
  484. observed by the kernel, are mathematically correct), the
  485. kernel reports nothing.
  486. NOTE: this feature can also be enabled for rwlocks, mutexes
  487. and rwsems - in which case all dependencies between these
  488. different locking variants are observed and mapped too, and
  489. the proof of observed correctness is also maintained for an
  490. arbitrary combination of these separate locking variants.
  491. For more details, see Documentation/lockdep-design.txt.
  492. config PROVE_RCU
  493. bool "RCU debugging: prove RCU correctness"
  494. depends on PROVE_LOCKING
  495. default n
  496. help
  497. This feature enables lockdep extensions that check for correct
  498. use of RCU APIs. This is currently under development. Say Y
  499. if you want to debug RCU usage or help work on the PROVE_RCU
  500. feature.
  501. Say N if you are unsure.
  502. config PROVE_RCU_REPEATEDLY
  503. bool "RCU debugging: don't disable PROVE_RCU on first splat"
  504. depends on PROVE_RCU
  505. default n
  506. help
  507. By itself, PROVE_RCU will disable checking upon issuing the
  508. first warning (or "splat"). This feature prevents such
  509. disabling, allowing multiple RCU-lockdep warnings to be printed
  510. on a single reboot.
  511. Say Y to allow multiple RCU-lockdep warnings per boot.
  512. Say N if you are unsure.
  513. config SPARSE_RCU_POINTER
  514. bool "RCU debugging: sparse-based checks for pointer usage"
  515. default n
  516. help
  517. This feature enables the __rcu sparse annotation for
  518. RCU-protected pointers. This annotation will cause sparse
  519. to flag any non-RCU used of annotated pointers. This can be
  520. helpful when debugging RCU usage. Please note that this feature
  521. is not intended to enforce code cleanliness; it is instead merely
  522. a debugging aid.
  523. Say Y to make sparse flag questionable use of RCU-protected pointers
  524. Say N if you are unsure.
  525. config LOCKDEP
  526. bool
  527. depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
  528. select STACKTRACE
  529. select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE
  530. select KALLSYMS
  531. select KALLSYMS_ALL
  532. config LOCK_STAT
  533. bool "Lock usage statistics"
  534. depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
  535. select LOCKDEP
  536. select DEBUG_SPINLOCK
  537. select DEBUG_MUTEXES
  538. select DEBUG_LOCK_ALLOC
  539. default n
  540. help
  541. This feature enables tracking lock contention points
  542. For more details, see Documentation/lockstat.txt
  543. This also enables lock events required by "perf lock",
  544. subcommand of perf.
  545. If you want to use "perf lock", you also need to turn on
  546. CONFIG_EVENT_TRACING.
  547. CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
  548. (CONFIG_LOCKDEP defines "acquire" and "release" events.)
  549. config DEBUG_LOCKDEP
  550. bool "Lock dependency engine debugging"
  551. depends on DEBUG_KERNEL && LOCKDEP
  552. help
  553. If you say Y here, the lock dependency engine will do
  554. additional runtime checks to debug itself, at the price
  555. of more runtime overhead.
  556. config TRACE_IRQFLAGS
  557. bool
  558. help
  559. Enables hooks to interrupt enabling and disabling for
  560. either tracing or lock debugging.
  561. config DEBUG_ATOMIC_SLEEP
  562. bool "Sleep inside atomic section checking"
  563. select PREEMPT_COUNT
  564. depends on DEBUG_KERNEL
  565. help
  566. If you say Y here, various routines which may sleep will become very
  567. noisy if they are called inside atomic sections: when a spinlock is
  568. held, inside an rcu read side critical section, inside preempt disabled
  569. sections, inside an interrupt, etc...
  570. config DEBUG_LOCKING_API_SELFTESTS
  571. bool "Locking API boot-time self-tests"
  572. depends on DEBUG_KERNEL
  573. help
  574. Say Y here if you want the kernel to run a short self-test during
  575. bootup. The self-test checks whether common types of locking bugs
  576. are detected by debugging mechanisms or not. (if you disable
  577. lock debugging then those bugs wont be detected of course.)
  578. The following locking APIs are covered: spinlocks, rwlocks,
  579. mutexes and rwsems.
  580. config STACKTRACE
  581. bool "Stacktrace"
  582. depends on STACKTRACE_SUPPORT
  583. default y
  584. config DEBUG_STACK_USAGE
  585. bool "Stack utilization instrumentation"
  586. depends on DEBUG_KERNEL
  587. help
  588. Enables the display of the minimum amount of free stack which each
  589. task has ever had available in the sysrq-T and sysrq-P debug output.
  590. This option will slow down process creation somewhat.
  591. config DEBUG_KOBJECT
  592. bool "kobject debugging"
  593. depends on DEBUG_KERNEL
  594. help
  595. If you say Y here, some extra kobject debugging messages will be sent
  596. to the syslog.
  597. config DEBUG_HIGHMEM
  598. bool "Highmem debugging"
  599. depends on DEBUG_KERNEL && HIGHMEM
  600. help
  601. This options enables addition error checking for high memory systems.
  602. Disable for production systems.
  603. config DEBUG_BUGVERBOSE
  604. bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
  605. depends on BUG
  606. depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
  607. FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE
  608. default y
  609. help
  610. Say Y here to make BUG() panics output the file name and line number
  611. of the BUG call as well as the EIP and oops trace. This aids
  612. debugging but costs about 70-100K of memory.
  613. config DEBUG_INFO
  614. bool "Compile the kernel with debug info"
  615. depends on DEBUG_KERNEL
  616. help
  617. If you say Y here the resulting kernel image will include
  618. debugging info resulting in a larger kernel image.
  619. This adds debug symbols to the kernel and modules (gcc -g), and
  620. is needed if you intend to use kernel crashdump or binary object
  621. tools like crash, kgdb, LKCD, gdb, etc on the kernel.
  622. Say Y here only if you plan to debug the kernel.
  623. If unsure, say N.
  624. config DEBUG_INFO_REDUCED
  625. bool "Reduce debugging information"
  626. depends on DEBUG_INFO
  627. help
  628. If you say Y here gcc is instructed to generate less debugging
  629. information for structure types. This means that tools that
  630. need full debugging information (like kgdb or systemtap) won't
  631. be happy. But if you merely need debugging information to
  632. resolve line numbers there is no loss. Advantage is that
  633. build directory object sizes shrink dramatically over a full
  634. DEBUG_INFO build and compile times are reduced too.
  635. Only works with newer gcc versions.
  636. config DEBUG_VM
  637. bool "Debug VM"
  638. depends on DEBUG_KERNEL
  639. help
  640. Enable this to turn on extended checks in the virtual-memory system
  641. that may impact performance.
  642. If unsure, say N.
  643. config DEBUG_VIRTUAL
  644. bool "Debug VM translations"
  645. depends on DEBUG_KERNEL && X86
  646. help
  647. Enable some costly sanity checks in virtual to page code. This can
  648. catch mistakes with virt_to_page() and friends.
  649. If unsure, say N.
  650. config DEBUG_NOMMU_REGIONS
  651. bool "Debug the global anon/private NOMMU mapping region tree"
  652. depends on DEBUG_KERNEL && !MMU
  653. help
  654. This option causes the global tree of anonymous and private mapping
  655. regions to be regularly checked for invalid topology.
  656. config DEBUG_WRITECOUNT
  657. bool "Debug filesystem writers count"
  658. depends on DEBUG_KERNEL
  659. help
  660. Enable this to catch wrong use of the writers count in struct
  661. vfsmount. This will increase the size of each file struct by
  662. 32 bits.
  663. If unsure, say N.
  664. config DEBUG_MEMORY_INIT
  665. bool "Debug memory initialisation" if EXPERT
  666. default !EXPERT
  667. help
  668. Enable this for additional checks during memory initialisation.
  669. The sanity checks verify aspects of the VM such as the memory model
  670. and other information provided by the architecture. Verbose
  671. information will be printed at KERN_DEBUG loglevel depending
  672. on the mminit_loglevel= command-line option.
  673. If unsure, say Y
  674. config DEBUG_LIST
  675. bool "Debug linked list manipulation"
  676. depends on DEBUG_KERNEL
  677. help
  678. Enable this to turn on extended checks in the linked-list
  679. walking routines.
  680. If unsure, say N.
  681. config TEST_LIST_SORT
  682. bool "Linked list sorting test"
  683. depends on DEBUG_KERNEL
  684. help
  685. Enable this to turn on 'list_sort()' function test. This test is
  686. executed only once during system boot, so affects only boot time.
  687. If unsure, say N.
  688. config DEBUG_SG
  689. bool "Debug SG table operations"
  690. depends on DEBUG_KERNEL
  691. help
  692. Enable this to turn on checks on scatter-gather tables. This can
  693. help find problems with drivers that do not properly initialize
  694. their sg tables.
  695. If unsure, say N.
  696. config DEBUG_NOTIFIERS
  697. bool "Debug notifier call chains"
  698. depends on DEBUG_KERNEL
  699. help
  700. Enable this to turn on sanity checking for notifier call chains.
  701. This is most useful for kernel developers to make sure that
  702. modules properly unregister themselves from notifier chains.
  703. This is a relatively cheap check but if you care about maximum
  704. performance, say N.
  705. config DEBUG_CREDENTIALS
  706. bool "Debug credential management"
  707. depends on DEBUG_KERNEL
  708. help
  709. Enable this to turn on some debug checking for credential
  710. management. The additional code keeps track of the number of
  711. pointers from task_structs to any given cred struct, and checks to
  712. see that this number never exceeds the usage count of the cred
  713. struct.
  714. Furthermore, if SELinux is enabled, this also checks that the
  715. security pointer in the cred struct is never seen to be invalid.
  716. If unsure, say N.
  717. #
  718. # Select this config option from the architecture Kconfig, if it
  719. # is preferred to always offer frame pointers as a config
  720. # option on the architecture (regardless of KERNEL_DEBUG):
  721. #
  722. config ARCH_WANT_FRAME_POINTERS
  723. bool
  724. help
  725. config FRAME_POINTER
  726. bool "Compile the kernel with frame pointers"
  727. depends on DEBUG_KERNEL && \
  728. (CRIS || M68K || FRV || UML || \
  729. AVR32 || SUPERH || BLACKFIN || MN10300) || \
  730. ARCH_WANT_FRAME_POINTERS
  731. default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
  732. help
  733. If you say Y here the resulting kernel image will be slightly
  734. larger and slower, but it gives very useful debugging information
  735. in case of kernel bugs. (precise oopses/stacktraces/warnings)
  736. config BOOT_PRINTK_DELAY
  737. bool "Delay each boot printk message by N milliseconds"
  738. depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
  739. help
  740. This build option allows you to read kernel boot messages
  741. by inserting a short delay after each one. The delay is
  742. specified in milliseconds on the kernel command line,
  743. using "boot_delay=N".
  744. It is likely that you would also need to use "lpj=M" to preset
  745. the "loops per jiffie" value.
  746. See a previous boot log for the "lpj" value to use for your
  747. system, and then set "lpj=M" before setting "boot_delay=N".
  748. NOTE: Using this option may adversely affect SMP systems.
  749. I.e., processors other than the first one may not boot up.
  750. BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
  751. what it believes to be lockup conditions.
  752. config RCU_TORTURE_TEST
  753. tristate "torture tests for RCU"
  754. depends on DEBUG_KERNEL
  755. default n
  756. help
  757. This option provides a kernel module that runs torture tests
  758. on the RCU infrastructure. The kernel module may be built
  759. after the fact on the running kernel to be tested, if desired.
  760. Say Y here if you want RCU torture tests to be built into
  761. the kernel.
  762. Say M if you want the RCU torture tests to build as a module.
  763. Say N if you are unsure.
  764. config RCU_TORTURE_TEST_RUNNABLE
  765. bool "torture tests for RCU runnable by default"
  766. depends on RCU_TORTURE_TEST = y
  767. default n
  768. help
  769. This option provides a way to build the RCU torture tests
  770. directly into the kernel without them starting up at boot
  771. time. You can use /proc/sys/kernel/rcutorture_runnable
  772. to manually override this setting. This /proc file is
  773. available only when the RCU torture tests have been built
  774. into the kernel.
  775. Say Y here if you want the RCU torture tests to start during
  776. boot (you probably don't).
  777. Say N here if you want the RCU torture tests to start only
  778. after being manually enabled via /proc.
  779. config RCU_CPU_STALL_TIMEOUT
  780. int "RCU CPU stall timeout in seconds"
  781. depends on TREE_RCU || TREE_PREEMPT_RCU
  782. range 3 300
  783. default 60
  784. help
  785. If a given RCU grace period extends more than the specified
  786. number of seconds, a CPU stall warning is printed. If the
  787. RCU grace period persists, additional CPU stall warnings are
  788. printed at more widely spaced intervals.
  789. config RCU_CPU_STALL_VERBOSE
  790. bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
  791. depends on TREE_PREEMPT_RCU
  792. default y
  793. help
  794. This option causes RCU to printk detailed per-task information
  795. for any tasks that are stalling the current RCU grace period.
  796. Say N if you are unsure.
  797. Say Y if you want to enable such checks.
  798. config RCU_CPU_STALL_INFO
  799. bool "Print additional diagnostics on RCU CPU stall"
  800. depends on (TREE_RCU || TREE_PREEMPT_RCU) && DEBUG_KERNEL
  801. default n
  802. help
  803. For each stalled CPU that is aware of the current RCU grace
  804. period, print out additional per-CPU diagnostic information
  805. regarding scheduling-clock ticks, idle state, and,
  806. for RCU_FAST_NO_HZ kernels, idle-entry state.
  807. Say N if you are unsure.
  808. Say Y if you want to enable such diagnostics.
  809. config RCU_TRACE
  810. bool "Enable tracing for RCU"
  811. depends on DEBUG_KERNEL
  812. help
  813. This option provides tracing in RCU which presents stats
  814. in debugfs for debugging RCU implementation.
  815. Say Y here if you want to enable RCU tracing
  816. Say N if you are unsure.
  817. config KPROBES_SANITY_TEST
  818. bool "Kprobes sanity tests"
  819. depends on DEBUG_KERNEL
  820. depends on KPROBES
  821. default n
  822. help
  823. This option provides for testing basic kprobes functionality on
  824. boot. A sample kprobe, jprobe and kretprobe are inserted and
  825. verified for functionality.
  826. Say N if you are unsure.
  827. config BACKTRACE_SELF_TEST
  828. tristate "Self test for the backtrace code"
  829. depends on DEBUG_KERNEL
  830. default n
  831. help
  832. This option provides a kernel module that can be used to test
  833. the kernel stack backtrace code. This option is not useful
  834. for distributions or general kernels, but only for kernel
  835. developers working on architecture code.
  836. Note that if you want to also test saved backtraces, you will
  837. have to enable STACKTRACE as well.
  838. Say N if you are unsure.
  839. config DEBUG_BLOCK_EXT_DEVT
  840. bool "Force extended block device numbers and spread them"
  841. depends on DEBUG_KERNEL
  842. depends on BLOCK
  843. default n
  844. help
  845. BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
  846. SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
  847. YOU ARE DOING. Distros, please enable this and fix whatever
  848. is broken.
  849. Conventionally, block device numbers are allocated from
  850. predetermined contiguous area. However, extended block area
  851. may introduce non-contiguous block device numbers. This
  852. option forces most block device numbers to be allocated from
  853. the extended space and spreads them to discover kernel or
  854. userland code paths which assume predetermined contiguous
  855. device number allocation.
  856. Note that turning on this debug option shuffles all the
  857. device numbers for all IDE and SCSI devices including libata
  858. ones, so root partition specified using device number
  859. directly (via rdev or root=MAJ:MIN) won't work anymore.
  860. Textual device names (root=/dev/sdXn) will continue to work.
  861. Say N if you are unsure.
  862. config DEBUG_FORCE_WEAK_PER_CPU
  863. bool "Force weak per-cpu definitions"
  864. depends on DEBUG_KERNEL
  865. help
  866. s390 and alpha require percpu variables in modules to be
  867. defined weak to work around addressing range issue which
  868. puts the following two restrictions on percpu variable
  869. definitions.
  870. 1. percpu symbols must be unique whether static or not
  871. 2. percpu variables can't be defined inside a function
  872. To ensure that generic code follows the above rules, this
  873. option forces all percpu variables to be defined as weak.
  874. config DEBUG_PER_CPU_MAPS
  875. bool "Debug access to per_cpu maps"
  876. depends on DEBUG_KERNEL
  877. depends on SMP
  878. help
  879. Say Y to verify that the per_cpu map being accessed has
  880. been set up. This adds a fair amount of code to kernel memory
  881. and decreases performance.
  882. Say N if unsure.
  883. config LKDTM
  884. tristate "Linux Kernel Dump Test Tool Module"
  885. depends on DEBUG_FS
  886. depends on BLOCK
  887. default n
  888. help
  889. This module enables testing of the different dumping mechanisms by
  890. inducing system failures at predefined crash points.
  891. If you don't need it: say N
  892. Choose M here to compile this code as a module. The module will be
  893. called lkdtm.
  894. Documentation on how to use the module can be found in
  895. Documentation/fault-injection/provoke-crashes.txt
  896. config CPU_NOTIFIER_ERROR_INJECT
  897. tristate "CPU notifier error injection module"
  898. depends on HOTPLUG_CPU && DEBUG_KERNEL
  899. help
  900. This option provides a kernel module that can be used to test
  901. the error handling of the cpu notifiers
  902. To compile this code as a module, choose M here: the module will
  903. be called cpu-notifier-error-inject.
  904. If unsure, say N.
  905. config FAULT_INJECTION
  906. bool "Fault-injection framework"
  907. depends on DEBUG_KERNEL
  908. help
  909. Provide fault-injection framework.
  910. For more details, see Documentation/fault-injection/.
  911. config FAILSLAB
  912. bool "Fault-injection capability for kmalloc"
  913. depends on FAULT_INJECTION
  914. depends on SLAB || SLUB
  915. help
  916. Provide fault-injection capability for kmalloc.
  917. config FAIL_PAGE_ALLOC
  918. bool "Fault-injection capabilitiy for alloc_pages()"
  919. depends on FAULT_INJECTION
  920. help
  921. Provide fault-injection capability for alloc_pages().
  922. config FAIL_MAKE_REQUEST
  923. bool "Fault-injection capability for disk IO"
  924. depends on FAULT_INJECTION && BLOCK
  925. help
  926. Provide fault-injection capability for disk IO.
  927. config FAIL_IO_TIMEOUT
  928. bool "Fault-injection capability for faking disk interrupts"
  929. depends on FAULT_INJECTION && BLOCK
  930. help
  931. Provide fault-injection capability on end IO handling. This
  932. will make the block layer "forget" an interrupt as configured,
  933. thus exercising the error handling.
  934. Only works with drivers that use the generic timeout handling,
  935. for others it wont do anything.
  936. config FAIL_MMC_REQUEST
  937. bool "Fault-injection capability for MMC IO"
  938. select DEBUG_FS
  939. depends on FAULT_INJECTION && MMC
  940. help
  941. Provide fault-injection capability for MMC IO.
  942. This will make the mmc core return data errors. This is
  943. useful to test the error handling in the mmc block device
  944. and to test how the mmc host driver handles retries from
  945. the block device.
  946. config FAULT_INJECTION_DEBUG_FS
  947. bool "Debugfs entries for fault-injection capabilities"
  948. depends on FAULT_INJECTION && SYSFS && DEBUG_FS
  949. help
  950. Enable configuration of fault-injection capabilities via debugfs.
  951. config FAULT_INJECTION_STACKTRACE_FILTER
  952. bool "stacktrace filter for fault-injection capabilities"
  953. depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
  954. depends on !X86_64
  955. select STACKTRACE
  956. select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND
  957. help
  958. Provide stacktrace filter for fault-injection capabilities
  959. config LATENCYTOP
  960. bool "Latency measuring infrastructure"
  961. depends on HAVE_LATENCYTOP_SUPPORT
  962. depends on DEBUG_KERNEL
  963. depends on STACKTRACE_SUPPORT
  964. depends on PROC_FS
  965. select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND
  966. select KALLSYMS
  967. select KALLSYMS_ALL
  968. select STACKTRACE
  969. select SCHEDSTATS
  970. select SCHED_DEBUG
  971. help
  972. Enable this option if you want to use the LatencyTOP tool
  973. to find out which userspace is blocking on what kernel operations.
  974. source mm/Kconfig.debug
  975. source kernel/trace/Kconfig
  976. config PROVIDE_OHCI1394_DMA_INIT
  977. bool "Remote debugging over FireWire early on boot"
  978. depends on PCI && X86
  979. help
  980. If you want to debug problems which hang or crash the kernel early
  981. on boot and the crashing machine has a FireWire port, you can use
  982. this feature to remotely access the memory of the crashed machine
  983. over FireWire. This employs remote DMA as part of the OHCI1394
  984. specification which is now the standard for FireWire controllers.
  985. With remote DMA, you can monitor the printk buffer remotely using
  986. firescope and access all memory below 4GB using fireproxy from gdb.
  987. Even controlling a kernel debugger is possible using remote DMA.
  988. Usage:
  989. If ohci1394_dma=early is used as boot parameter, it will initialize
  990. all OHCI1394 controllers which are found in the PCI config space.
  991. As all changes to the FireWire bus such as enabling and disabling
  992. devices cause a bus reset and thereby disable remote DMA for all
  993. devices, be sure to have the cable plugged and FireWire enabled on
  994. the debugging host before booting the debug target for debugging.
  995. This code (~1k) is freed after boot. By then, the firewire stack
  996. in charge of the OHCI-1394 controllers should be used instead.
  997. See Documentation/debugging-via-ohci1394.txt for more information.
  998. config FIREWIRE_OHCI_REMOTE_DMA
  999. bool "Remote debugging over FireWire with firewire-ohci"
  1000. depends on FIREWIRE_OHCI
  1001. help
  1002. This option lets you use the FireWire bus for remote debugging
  1003. with help of the firewire-ohci driver. It enables unfiltered
  1004. remote DMA in firewire-ohci.
  1005. See Documentation/debugging-via-ohci1394.txt for more information.
  1006. If unsure, say N.
  1007. config BUILD_DOCSRC
  1008. bool "Build targets in Documentation/ tree"
  1009. depends on HEADERS_CHECK
  1010. help
  1011. This option attempts to build objects from the source files in the
  1012. kernel Documentation/ tree.
  1013. Say N if you are unsure.
  1014. config DYNAMIC_DEBUG
  1015. bool "Enable dynamic printk() support"
  1016. default n
  1017. depends on PRINTK
  1018. depends on DEBUG_FS
  1019. help
  1020. Compiles debug level messages into the kernel, which would not
  1021. otherwise be available at runtime. These messages can then be
  1022. enabled/disabled based on various levels of scope - per source file,
  1023. function, module, format string, and line number. This mechanism
  1024. implicitly enables all pr_debug() and dev_dbg() calls. The impact of
  1025. this compile option is a larger kernel text size of about 2%.
  1026. Usage:
  1027. Dynamic debugging is controlled via the 'dynamic_debug/control' file,
  1028. which is contained in the 'debugfs' filesystem. Thus, the debugfs
  1029. filesystem must first be mounted before making use of this feature.
  1030. We refer the control file as: <debugfs>/dynamic_debug/control. This
  1031. file contains a list of the debug statements that can be enabled. The
  1032. format for each line of the file is:
  1033. filename:lineno [module]function flags format
  1034. filename : source file of the debug statement
  1035. lineno : line number of the debug statement
  1036. module : module that contains the debug statement
  1037. function : function that contains the debug statement
  1038. flags : 'p' means the line is turned 'on' for printing
  1039. format : the format used for the debug statement
  1040. From a live system:
  1041. nullarbor:~ # cat <debugfs>/dynamic_debug/control
  1042. # filename:lineno [module]function flags format
  1043. fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
  1044. fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
  1045. fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
  1046. Example usage:
  1047. // enable the message at line 1603 of file svcsock.c
  1048. nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
  1049. <debugfs>/dynamic_debug/control
  1050. // enable all the messages in file svcsock.c
  1051. nullarbor:~ # echo -n 'file svcsock.c +p' >
  1052. <debugfs>/dynamic_debug/control
  1053. // enable all the messages in the NFS server module
  1054. nullarbor:~ # echo -n 'module nfsd +p' >
  1055. <debugfs>/dynamic_debug/control
  1056. // enable all 12 messages in the function svc_process()
  1057. nullarbor:~ # echo -n 'func svc_process +p' >
  1058. <debugfs>/dynamic_debug/control
  1059. // disable all 12 messages in the function svc_process()
  1060. nullarbor:~ # echo -n 'func svc_process -p' >
  1061. <debugfs>/dynamic_debug/control
  1062. See Documentation/dynamic-debug-howto.txt for additional information.
  1063. config DMA_API_DEBUG
  1064. bool "Enable debugging of DMA-API usage"
  1065. depends on HAVE_DMA_API_DEBUG
  1066. help
  1067. Enable this option to debug the use of the DMA API by device drivers.
  1068. With this option you will be able to detect common bugs in device
  1069. drivers like double-freeing of DMA mappings or freeing mappings that
  1070. were never allocated.
  1071. This option causes a performance degredation. Use only if you want
  1072. to debug device drivers. If unsure, say N.
  1073. config ATOMIC64_SELFTEST
  1074. bool "Perform an atomic64_t self-test at boot"
  1075. help
  1076. Enable this option to test the atomic64_t functions at boot.
  1077. If unsure, say N.
  1078. config ASYNC_RAID6_TEST
  1079. tristate "Self test for hardware accelerated raid6 recovery"
  1080. depends on ASYNC_RAID6_RECOV
  1081. select ASYNC_MEMCPY
  1082. ---help---
  1083. This is a one-shot self test that permutes through the
  1084. recovery of all the possible two disk failure scenarios for a
  1085. N-disk array. Recovery is performed with the asynchronous
  1086. raid6 recovery routines, and will optionally use an offload
  1087. engine if one is available.
  1088. If unsure, say N.
  1089. config PANIC_ON_DATA_CORRUPTION
  1090. bool "Cause a Kernel Panic When Data Corruption is detected"
  1091. help
  1092. Select this option to upgrade warnings for potentially
  1093. recoverable data corruption scenarios to system-halting panics,
  1094. for easier detection and debug.
  1095. config TEST_USER_COPY
  1096. tristate "Test user/kernel boundary protections"
  1097. default n
  1098. depends on m
  1099. help
  1100. This builds the "test_user_copy" module that runs sanity checks
  1101. on the copy_to/from_user infrastructure, making sure basic
  1102. user/kernel boundary testing is working. If it fails to load,
  1103. a regression has been detected in the user/kernel memory boundary
  1104. protections.
  1105. If unsure, say N.
  1106. source "samples/Kconfig"
  1107. source "lib/Kconfig.kgdb"
  1108. source "lib/Kconfig.kmemcheck"
  1109. config TEST_KSTRTOX
  1110. tristate "Test kstrto*() family of functions at runtime"
  1111. config TEST_HASH
  1112. tristate "Perform selftest on hash functions"
  1113. default n
  1114. help
  1115. Enable this option to test the kernel's siphash (<linux/siphash.h>)
  1116. hash functions on boot (or module load).
  1117. This is intended to help people writing architecture-specific
  1118. optimized versions. If unsure, say N.