lib/Kconfig.debug

   1
   2 config PRINTK_TIME
   3         bool "Show timing information on printks"
   4         depends on PRINTK
   5         help
   6           Selecting this option causes timing information to be
   7           included in printk output.  This allows you to measure
   8           the interval between kernel operations, including bootup
   9           operations.  This is useful for identifying long delays
  10           in kernel startup.
  11
  12 config ENABLE_WARN_DEPRECATED
  13         bool "Enable __deprecated logic"
  14         default y
  15         help
  16           Enable the __deprecated logic in the kernel build.
  17           Disable this to suppress the "warning: 'foo' is deprecated
  18           (declared at kernel/power/somefile.c:1234)" messages.
  19
  20 config ENABLE_MUST_CHECK
  21         bool "Enable __must_check logic"
  22         default y
  23         help
  24           Enable the __must_check logic in the kernel build.  Disable this to
  25           suppress the "warning: ignoring return value of 'foo', declared with
  26           attribute warn_unused_result" messages.
  27
  28 config FRAME_WARN
  29         int "Warn for stack frames larger than (needs gcc 4.4)"
  30         range 0 8192
  31         default 1024 if !64BIT
  32         default 2048 if 64BIT
  33         help
  34           Tell gcc to warn at build time for stack frames larger than this.
  35           Setting this too low will cause a lot of warnings.
  36           Setting it to 0 disables the warning.
  37           Requires gcc 4.4
  38
  39 config MAGIC_SYSRQ
  40         bool "Magic SysRq key"
  41         depends on !UML
  42         help
  43           If you say Y here, you will have some control over the system even
  44           if the system crashes for example during kernel debugging (e.g., you
  45           will be able to flush the buffer cache to disk, reboot the system
  46           immediately or dump some status information). This is accomplished
  47           by pressing various keys while holding SysRq (Alt+PrintScreen). It
  48           also works on a serial console (on PC hardware at least), if you
  49           send a BREAK and then within 5 seconds a command keypress. The
  50           keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  51           unless you really know what this hack does.
  52
  53 config UNUSED_SYMBOLS
  54         bool "Enable unused/obsolete exported symbols"
  55         default y if X86
  56         help
  57           Unused but exported symbols make the kernel needlessly bigger.  For
  58           that reason most of these unused exports will soon be removed.  This
  59           option is provided temporarily to provide a transition period in case
  60           some external kernel module needs one of these symbols anyway. If you
  61           encounter such a case in your module, consider if you are actually
  62           using the right API.  (rationale: since nobody in the kernel is using
  63           this in a module, there is a pretty good chance it's actually the
  64           wrong interface to use).  If you really need the symbol, please send a
  65           mail to the linux kernel mailing list mentioning the symbol and why
  66           you really need it, and what the merge plan to the mainline kernel for
  67           your module is.
  68
  69 config DEBUG_FS
  70         bool "Debug Filesystem"
  71         depends on SYSFS
  72         help
  73           debugfs is a virtual file system that kernel developers use to put
  74           debugging files into.  Enable this option to be able to read and
  75           write to these files.
  76
  77           For detailed documentation on the debugfs API, see
  78           Documentation/DocBook/filesystems.
  79
  80           If unsure, say N.
  81
  82 config HEADERS_CHECK
  83         bool "Run 'make headers_check' when building vmlinux"
  84         depends on !UML
  85         help
  86           This option will extract the user-visible kernel headers whenever
  87           building the kernel, and will run basic sanity checks on them to
  88           ensure that exported files do not attempt to include files which
  89           were not exported, etc.
  90
  91           If you're making modifications to header files which are
  92           relevant for userspace, say 'Y', and check the headers
  93           exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
  94           your build tree), to make sure they're suitable.
  95
  96 config DEBUG_SECTION_MISMATCH
  97         bool "Enable full Section mismatch analysis"
  98         depends on UNDEFINED
  99         # This option is on purpose disabled for now.
 100         # It will be enabled when we are down to a resonable number
 101         # of section mismatch warnings (< 10 for an allyesconfig build)
 102         help
 103           The section mismatch analysis checks if there are illegal
 104           references from one section to another section.
 105           Linux will during link or during runtime drop some sections
 106           and any use of code/data previously in these sections will
 107           most likely result in an oops.
 108           In the code functions and variables are annotated with
 109           __init, __devinit etc. (see 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 done after a full
 112           kernel build but enabling this option will in addition
 113           do the following:
 114           - Add the option -fno-inline-functions-called-once to gcc
 115             When inlining a function annotated __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 will also
 119             result in a larger kernel.
 120           - Run the section mismatch analysis for each module/built-in.o
 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             will tell where the mismatch happens much closer to the
 126             source. The drawback is that we will report the same
 127             mismatch at least twice.
 128           - Enable verbose reporting from modpost to help solving
 129             the section mismatches reported.
 130
 131 config DEBUG_KERNEL
 132         bool "Kernel debugging"
 133         help
 134           Say Y here if you are developing drivers or trying to debug and
 135           identify kernel problems.
 136
 137 config DEBUG_SHIRQ
 138         bool "Debug shared IRQ handlers"
 139         depends on DEBUG_KERNEL && GENERIC_HARDIRQS
 140         help
 141           Enable this to generate a spurious interrupt as soon as a shared
 142           interrupt handler is registered, and just before one is deregistered.
 143           Drivers ought to be able to handle interrupts coming in at those
 144           points; some don't and need to be caught.
 145
 146 config DETECT_SOFTLOCKUP
 147         bool "Detect Soft Lockups"
 148         depends on DEBUG_KERNEL && !S390
 149         default y
 150         help
 151           Say Y here to enable the kernel to detect "soft lockups",
 152           which are bugs that cause the kernel to loop in kernel
 153           mode for more than 60 seconds, without giving other tasks a
 154           chance to run.
 155
 156           When a soft-lockup is detected, the kernel will print the
 157           current stack trace (which you should report), but the
 158           system will stay locked up. This feature has negligible
 159           overhead.
 160
 161           (Note that "hard lockups" are separate type of bugs that
 162            can be detected via the NMI-watchdog, on platforms that
 163            support it.)
 164
 165 config BOOTPARAM_SOFTLOCKUP_PANIC
 166         bool "Panic (Reboot) On Soft Lockups"
 167         depends on DETECT_SOFTLOCKUP
 168         help
 169           Say Y here to enable the kernel to panic on "soft lockups",
 170           which are bugs that cause the kernel to loop in kernel
 171           mode for more than 60 seconds, without giving other tasks a
 172           chance to run.
 173
 174           The panic can be used in combination with panic_timeout,
 175           to cause the system to reboot automatically after a
 176           lockup has been detected. This feature is useful for
 177           high-availability systems that have uptime guarantees and
 178           where a lockup must be resolved ASAP.
 179
 180           Say N if unsure.
 181
 182 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
 183         int
 184         depends on DETECT_SOFTLOCKUP
 185         range 0 1
 186         default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
 187         default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
 188
 189 config SCHED_DEBUG
 190         bool "Collect scheduler debugging info"
 191         depends on DEBUG_KERNEL && PROC_FS
 192         default y
 193         help
 194           If you say Y here, the /proc/sched_debug file will be provided
 195           that can help debug the scheduler. The runtime overhead of this
 196           option is minimal.
 197
 198 config SCHEDSTATS
 199         bool "Collect scheduler statistics"
 200         depends on DEBUG_KERNEL && PROC_FS
 201         help
 202           If you say Y here, additional code will be inserted into the
 203           scheduler and related routines to collect statistics about
 204           scheduler behavior and provide them in /proc/schedstat.  These
 205           stats may be useful for both tuning and debugging the scheduler
 206           If you aren't debugging the scheduler or trying to tune a specific
 207           application, you can say N to avoid the very slight overhead
 208           this adds.
 209
 210 config TIMER_STATS
 211         bool "Collect kernel timers statistics"
 212         depends on DEBUG_KERNEL && PROC_FS
 213         help
 214           If you say Y here, additional code will be inserted into the
 215           timer routines to collect statistics about kernel timers being
 216           reprogrammed. The statistics can be read from /proc/timer_stats.
 217           The statistics collection is started by writing 1 to /proc/timer_stats,
 218           writing 0 stops it. This feature is useful to collect information
 219           about timer usage patterns in kernel and userspace. This feature
 220           is lightweight if enabled in the kernel config but not activated
 221           (it defaults to deactivated on bootup and will only be activated
 222           if some application like powertop activates it explicitly).
 223
 224 config DEBUG_OBJECTS
 225         bool "Debug object operations"
 226         depends on DEBUG_KERNEL
 227         help
 228           If you say Y here, additional code will be inserted into the
 229           kernel to track the life time of various objects and validate
 230           the operations on those objects.
 231
 232 config DEBUG_OBJECTS_SELFTEST
 233         bool "Debug objects selftest"
 234         depends on DEBUG_OBJECTS
 235         help
 236           This enables the selftest of the object debug code.
 237
 238 config DEBUG_OBJECTS_FREE
 239         bool "Debug objects in freed memory"
 240         depends on DEBUG_OBJECTS
 241         help
 242           This enables checks whether a k/v free operation frees an area
 243           which contains an object which has not been deactivated
 244           properly. This can make kmalloc/kfree-intensive workloads
 245           much slower.
 246
 247 config DEBUG_OBJECTS_TIMERS
 248         bool "Debug timer objects"
 249         depends on DEBUG_OBJECTS
 250         help
 251           If you say Y here, additional code will be inserted into the
 252           timer routines to track the life time of timer objects and
 253           validate the timer operations.
 254
 255 config DEBUG_SLAB
 256         bool "Debug slab memory allocations"
 257         depends on DEBUG_KERNEL && SLAB
 258         help
 259           Say Y here to have the kernel do limited verification on memory
 260           allocation as well as poisoning memory on free to catch use of freed
 261           memory. This can make kmalloc/kfree-intensive workloads much slower.
 262
 263 config DEBUG_SLAB_LEAK
 264         bool "Memory leak debugging"
 265         depends on DEBUG_SLAB
 266
 267 config SLUB_DEBUG_ON
 268         bool "SLUB debugging on by default"
 269         depends on SLUB && SLUB_DEBUG
 270         default n
 271         help
 272           Boot with debugging on by default. SLUB boots by default with
 273           the runtime debug capabilities switched off. Enabling this is
 274           equivalent to specifying the "slub_debug" parameter on boot.
 275           There is no support for more fine grained debug control like
 276           possible with slub_debug=xxx. SLUB debugging may be switched
 277           off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
 278           "slub_debug=-".
 279
 280 config SLUB_STATS
 281         default n
 282         bool "Enable SLUB performance statistics"
 283         depends on SLUB && SLUB_DEBUG && SYSFS
 284         help
 285           SLUB statistics are useful to debug SLUBs allocation behavior in
 286           order find ways to optimize the allocator. This should never be
 287           enabled for production use since keeping statistics slows down
 288           the allocator by a few percentage points. The slabinfo command
 289           supports the determination of the most active slabs to figure
 290           out which slabs are relevant to a particular load.
 291           Try running: slabinfo -DA
 292
 293 config DEBUG_PREEMPT
 294         bool "Debug preemptible kernel"
 295         depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
 296         default y
 297         help
 298           If you say Y here then the kernel will use a debug variant of the
 299           commonly used smp_processor_id() function and will print warnings
 300           if kernel code uses it in a preemption-unsafe way. Also, the kernel
 301           will detect preemption count underflows.
 302
 303 config DEBUG_RT_MUTEXES
 304         bool "RT Mutex debugging, deadlock detection"
 305         depends on DEBUG_KERNEL && RT_MUTEXES
 306         help
 307          This allows rt mutex semantics violations and rt mutex related
 308          deadlocks (lockups) to be detected and reported automatically.
 309
 310 config DEBUG_PI_LIST
 311         bool
 312         default y
 313         depends on DEBUG_RT_MUTEXES
 314
 315 config RT_MUTEX_TESTER
 316         bool "Built-in scriptable tester for rt-mutexes"
 317         depends on DEBUG_KERNEL && RT_MUTEXES
 318         help
 319           This option enables a rt-mutex tester.
 320
 321 config DEBUG_SPINLOCK
 322         bool "Spinlock and rw-lock debugging: basic checks"
 323         depends on DEBUG_KERNEL
 324         help
 325           Say Y here and build SMP to catch missing spinlock initialization
 326           and certain other kinds of spinlock errors commonly made.  This is
 327           best used in conjunction with the NMI watchdog so that spinlock
 328           deadlocks are also debuggable.
 329
 330 config DEBUG_MUTEXES
 331         bool "Mutex debugging: basic checks"
 332         depends on DEBUG_KERNEL
 333         help
 334          This feature allows mutex semantics violations to be detected and
 335          reported.
 336
 337 config DEBUG_LOCK_ALLOC
 338         bool "Lock debugging: detect incorrect freeing of live locks"
 339         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 340         select DEBUG_SPINLOCK
 341         select DEBUG_MUTEXES
 342         select LOCKDEP
 343         help
 344          This feature will check whether any held lock (spinlock, rwlock,
 345          mutex or rwsem) is incorrectly freed by the kernel, via any of the
 346          memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
 347          vfree(), etc.), whether a live lock is incorrectly reinitialized via
 348          spin_lock_init()/mutex_init()/etc., or whether there is any lock
 349          held during task exit.
 350
 351 config PROVE_LOCKING
 352         bool "Lock debugging: prove locking correctness"
 353         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 354         select LOCKDEP
 355         select DEBUG_SPINLOCK
 356         select DEBUG_MUTEXES
 357         select DEBUG_LOCK_ALLOC
 358         default n
 359         help
 360          This feature enables the kernel to prove that all locking
 361          that occurs in the kernel runtime is mathematically
 362          correct: that under no circumstance could an arbitrary (and
 363          not yet triggered) combination of observed locking
 364          sequences (on an arbitrary number of CPUs, running an
 365          arbitrary number of tasks and interrupt contexts) cause a
 366          deadlock.
 367
 368          In short, this feature enables the kernel to report locking
 369          related deadlocks before they actually occur.
 370
 371          The proof does not depend on how hard and complex a
 372          deadlock scenario would be to trigger: how many
 373          participant CPUs, tasks and irq-contexts would be needed
 374          for it to trigger. The proof also does not depend on
 375          timing: if a race and a resulting deadlock is possible
 376          theoretically (no matter how unlikely the race scenario
 377          is), it will be proven so and will immediately be
 378          reported by the kernel (once the event is observed that
 379          makes the deadlock theoretically possible).
 380
 381          If a deadlock is impossible (i.e. the locking rules, as
 382          observed by the kernel, are mathematically correct), the
 383          kernel reports nothing.
 384
 385          NOTE: this feature can also be enabled for rwlocks, mutexes
 386          and rwsems - in which case all dependencies between these
 387          different locking variants are observed and mapped too, and
 388          the proof of observed correctness is also maintained for an
 389          arbitrary combination of these separate locking variants.
 390
 391          For more details, see Documentation/lockdep-design.txt.
 392
 393 config LOCKDEP
 394         bool
 395         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 396         select STACKTRACE
 397         select FRAME_POINTER if !X86 && !MIPS
 398         select KALLSYMS
 399         select KALLSYMS_ALL
 400
 401 config LOCK_STAT
 402         bool "Lock usage statistics"
 403         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
 404         select LOCKDEP
 405         select DEBUG_SPINLOCK
 406         select DEBUG_MUTEXES
 407         select DEBUG_LOCK_ALLOC
 408         default n
 409         help
 410          This feature enables tracking lock contention points
 411
 412          For more details, see Documentation/lockstat.txt
 413
 414 config DEBUG_LOCKDEP
 415         bool "Lock dependency engine debugging"
 416         depends on DEBUG_KERNEL && LOCKDEP
 417         help
 418           If you say Y here, the lock dependency engine will do
 419           additional runtime checks to debug itself, at the price
 420           of more runtime overhead.
 421
 422 config TRACE_IRQFLAGS
 423         depends on DEBUG_KERNEL
 424         bool
 425         default y
 426         depends on TRACE_IRQFLAGS_SUPPORT
 427         depends on PROVE_LOCKING
 428
 429 config DEBUG_SPINLOCK_SLEEP
 430         bool "Spinlock debugging: sleep-inside-spinlock checking"
 431         depends on DEBUG_KERNEL
 432         help
 433           If you say Y here, various routines which may sleep will become very
 434           noisy if they are called with a spinlock held.
 435
 436 config DEBUG_LOCKING_API_SELFTESTS
 437         bool "Locking API boot-time self-tests"
 438         depends on DEBUG_KERNEL
 439         help
 440           Say Y here if you want the kernel to run a short self-test during
 441           bootup. The self-test checks whether common types of locking bugs
 442           are detected by debugging mechanisms or not. (if you disable
 443           lock debugging then those bugs wont be detected of course.)
 444           The following locking APIs are covered: spinlocks, rwlocks,
 445           mutexes and rwsems.
 446
 447 config STACKTRACE
 448         bool
 449         depends on STACKTRACE_SUPPORT
 450
 451 config DEBUG_KOBJECT
 452         bool "kobject debugging"
 453         depends on DEBUG_KERNEL
 454         help
 455           If you say Y here, some extra kobject debugging messages will be sent
 456           to the syslog.
 457
 458 config DEBUG_HIGHMEM
 459         bool "Highmem debugging"
 460         depends on DEBUG_KERNEL && HIGHMEM
 461         help
 462           This options enables addition error checking for high memory systems.
 463           Disable for production systems.
 464
 465 config DEBUG_BUGVERBOSE
 466         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
 467         depends on BUG
 468         depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
 469                    FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
 470         default !EMBEDDED
 471         help
 472           Say Y here to make BUG() panics output the file name and line number
 473           of the BUG call as well as the EIP and oops trace.  This aids
 474           debugging but costs about 70-100K of memory.
 475
 476 config DEBUG_INFO
 477         bool "Compile the kernel with debug info"
 478         depends on DEBUG_KERNEL
 479         help
 480           If you say Y here the resulting kernel image will include
 481           debugging info resulting in a larger kernel image.
 482           This adds debug symbols to the kernel and modules (gcc -g), and
 483           is needed if you intend to use kernel crashdump or binary object
 484           tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 485           Say Y here only if you plan to debug the kernel.
 486
 487           If unsure, say N.
 488
 489 config DEBUG_VM
 490         bool "Debug VM"
 491         depends on DEBUG_KERNEL
 492         help
 493           Enable this to turn on extended checks in the virtual-memory system
 494           that may impact performance.
 495
 496           If unsure, say N.
 497
 498 config DEBUG_WRITECOUNT
 499         bool "Debug filesystem writers count"
 500         depends on DEBUG_KERNEL
 501         help
 502           Enable this to catch wrong use of the writers count in struct
 503           vfsmount.  This will increase the size of each file struct by
 504           32 bits.
 505
 506           If unsure, say N.
 507
 508 config DEBUG_MEMORY_INIT
 509         bool "Debug memory initialisation" if EMBEDDED
 510         default !EMBEDDED
 511         help
 512           Enable this for additional checks during memory initialisation.
 513           The sanity checks verify aspects of the VM such as the memory model
 514           and other information provided by the architecture. Verbose
 515           information will be printed at KERN_DEBUG loglevel depending
 516           on the mminit_loglevel= command-line option.
 517
 518           If unsure, say Y
 519
 520 config DEBUG_LIST
 521         bool "Debug linked list manipulation"
 522         depends on DEBUG_KERNEL
 523         help
 524           Enable this to turn on extended checks in the linked-list
 525           walking routines.
 526
 527           If unsure, say N.
 528
 529 config DEBUG_SG
 530         bool "Debug SG table operations"
 531         depends on DEBUG_KERNEL
 532         help
 533           Enable this to turn on checks on scatter-gather tables. This can
 534           help find problems with drivers that do not properly initialize
 535           their sg tables.
 536
 537           If unsure, say N.
 538
 539 config FRAME_POINTER
 540         bool "Compile the kernel with frame pointers"
 541         depends on DEBUG_KERNEL && \
 542                 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
 543                  AVR32 || SUPERH || BLACKFIN || MN10300)
 544         default y if DEBUG_INFO && UML
 545         help
 546           If you say Y here the resulting kernel image will be slightly larger
 547           and slower, but it might give very useful debugging information on
 548           some architectures or if you use external debuggers.
 549           If you don't debug the kernel, you can say N.
 550
 551 config BOOT_PRINTK_DELAY
 552         bool "Delay each boot printk message by N milliseconds"
 553         depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 554         help
 555           This build option allows you to read kernel boot messages
 556           by inserting a short delay after each one.  The delay is
 557           specified in milliseconds on the kernel command line,
 558           using "boot_delay=N".
 559
 560           It is likely that you would also need to use "lpj=M" to preset
 561           the "loops per jiffie" value.
 562           See a previous boot log for the "lpj" value to use for your
 563           system, and then set "lpj=M" before setting "boot_delay=N".
 564           NOTE:  Using this option may adversely affect SMP systems.
 565           I.e., processors other than the first one may not boot up.
 566           BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
 567           what it believes to be lockup conditions.
 568
 569 config RCU_TORTURE_TEST
 570         tristate "torture tests for RCU"
 571         depends on DEBUG_KERNEL
 572         default n
 573         help
 574           This option provides a kernel module that runs torture tests
 575           on the RCU infrastructure.  The kernel module may be built
 576           after the fact on the running kernel to be tested, if desired.
 577
 578           Say Y here if you want RCU torture tests to be built into
 579           the kernel.
 580           Say M if you want the RCU torture tests to build as a module.
 581           Say N if you are unsure.
 582
 583 config RCU_TORTURE_TEST_RUNNABLE
 584         bool "torture tests for RCU runnable by default"
 585         depends on RCU_TORTURE_TEST = y
 586         default n
 587         help
 588           This option provides a way to build the RCU torture tests
 589           directly into the kernel without them starting up at boot
 590           time.  You can use /proc/sys/kernel/rcutorture_runnable
 591           to manually override this setting.  This /proc file is
 592           available only when the RCU torture tests have been built
 593           into the kernel.
 594
 595           Say Y here if you want the RCU torture tests to start during
 596           boot (you probably don't).
 597           Say N here if you want the RCU torture tests to start only
 598           after being manually enabled via /proc.
 599
 600 config KPROBES_SANITY_TEST
 601         bool "Kprobes sanity tests"
 602         depends on DEBUG_KERNEL
 603         depends on KPROBES
 604         default n
 605         help
 606           This option provides for testing basic kprobes functionality on
 607           boot. A sample kprobe, jprobe and kretprobe are inserted and
 608           verified for functionality.
 609
 610           Say N if you are unsure.
 611
 612 config BACKTRACE_SELF_TEST
 613         tristate "Self test for the backtrace code"
 614         depends on DEBUG_KERNEL
 615         default n
 616         help
 617           This option provides a kernel module that can be used to test
 618           the kernel stack backtrace code. This option is not useful
 619           for distributions or general kernels, but only for kernel
 620           developers working on architecture code.
 621
 622           Note that if you want to also test saved backtraces, you will
 623           have to enable STACKTRACE as well.
 624
 625           Say N if you are unsure.
 626
 627 config LKDTM
 628         tristate "Linux Kernel Dump Test Tool Module"
 629         depends on DEBUG_KERNEL
 630         depends on KPROBES
 631         depends on BLOCK
 632         default n
 633         help
 634         This module enables testing of the different dumping mechanisms by
 635         inducing system failures at predefined crash points.
 636         If you don't need it: say N
 637         Choose M here to compile this code as a module. The module will be
 638         called lkdtm.
 639
 640         Documentation on how to use the module can be found in
 641         drivers/misc/lkdtm.c
 642
 643 config FAULT_INJECTION
 644         bool "Fault-injection framework"
 645         depends on DEBUG_KERNEL
 646         help
 647           Provide fault-injection framework.
 648           For more details, see Documentation/fault-injection/.
 649
 650 config FAILSLAB
 651         bool "Fault-injection capability for kmalloc"
 652         depends on FAULT_INJECTION
 653         help
 654           Provide fault-injection capability for kmalloc.
 655
 656 config FAIL_PAGE_ALLOC
 657         bool "Fault-injection capabilitiy for alloc_pages()"
 658         depends on FAULT_INJECTION
 659         help
 660           Provide fault-injection capability for alloc_pages().
 661
 662 config FAIL_MAKE_REQUEST
 663         bool "Fault-injection capability for disk IO"
 664         depends on FAULT_INJECTION
 665         help
 666           Provide fault-injection capability for disk IO.
 667
 668 config FAULT_INJECTION_DEBUG_FS
 669         bool "Debugfs entries for fault-injection capabilities"
 670         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
 671         help
 672           Enable configuration of fault-injection capabilities via debugfs.
 673
 674 config FAULT_INJECTION_STACKTRACE_FILTER
 675         bool "stacktrace filter for fault-injection capabilities"
 676         depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
 677         depends on !X86_64
 678         select STACKTRACE
 679         select FRAME_POINTER
 680         help
 681           Provide stacktrace filter for fault-injection capabilities
 682
 683 config LATENCYTOP
 684         bool "Latency measuring infrastructure"
 685         select FRAME_POINTER if !MIPS
 686         select KALLSYMS
 687         select KALLSYMS_ALL
 688         select STACKTRACE
 689         select SCHEDSTATS
 690         select SCHED_DEBUG
 691         depends on HAVE_LATENCYTOP_SUPPORT
 692         help
 693           Enable this option if you want to use the LatencyTOP tool
 694           to find out which userspace is blocking on what kernel operations.
 695
 696 source kernel/trace/Kconfig
 697
 698 config PROVIDE_OHCI1394_DMA_INIT
 699         bool "Remote debugging over FireWire early on boot"
 700         depends on PCI && X86
 701         help
 702           If you want to debug problems which hang or crash the kernel early
 703           on boot and the crashing machine has a FireWire port, you can use
 704           this feature to remotely access the memory of the crashed machine
 705           over FireWire. This employs remote DMA as part of the OHCI1394
 706           specification which is now the standard for FireWire controllers.
 707
 708           With remote DMA, you can monitor the printk buffer remotely using
 709           firescope and access all memory below 4GB using fireproxy from gdb.
 710           Even controlling a kernel debugger is possible using remote DMA.
 711
 712           Usage:
 713
 714           If ohci1394_dma=early is used as boot parameter, it will initialize
 715           all OHCI1394 controllers which are found in the PCI config space.
 716
 717           As all changes to the FireWire bus such as enabling and disabling
 718           devices cause a bus reset and thereby disable remote DMA for all
 719           devices, be sure to have the cable plugged and FireWire enabled on
 720           the debugging host before booting the debug target for debugging.
 721
 722           This code (~1k) is freed after boot. By then, the firewire stack
 723           in charge of the OHCI-1394 controllers should be used instead.
 724
 725           See Documentation/debugging-via-ohci1394.txt for more information.
 726
 727 config FIREWIRE_OHCI_REMOTE_DMA
 728         bool "Remote debugging over FireWire with firewire-ohci"
 729         depends on FIREWIRE_OHCI
 730         help
 731           This option lets you use the FireWire bus for remote debugging
 732           with help of the firewire-ohci driver. It enables unfiltered
 733           remote DMA in firewire-ohci.
 734           See Documentation/debugging-via-ohci1394.txt for more information.
 735
 736           If unsure, say N.
 737
 738 menuconfig BUILD_DOCSRC
 739         bool "Build targets in Documentation/ tree"
 740         depends on HEADERS_CHECK
 741         help
 742           This option attempts to build objects from the source files in the
 743           kernel Documentation/ tree.
 744
 745           Say N if you are unsure.
 746
 747 source "samples/Kconfig"
 748
 749 source "lib/Kconfig.kgdb"