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diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug new file mode 100644 index 00000000..c6b006a9 --- /dev/null +++ b/lib/Kconfig.debug @@ -0,0 +1,1264 @@ + +config PRINTK_TIME + bool "Show timing information on printks" + depends on PRINTK + help + Selecting this option causes timing information to be + included in printk output. This allows you to measure + the interval between kernel operations, including bootup + operations. This is useful for identifying long delays + in kernel startup. Or add printk.time=1 at boot-time. + See Documentation/kernel-parameters.txt + +config DEFAULT_MESSAGE_LOGLEVEL + int "Default message log level (1-7)" + range 1 7 + default "4" + help + Default log level for printk statements with no specified priority. + + This was hard-coded to KERN_WARNING since at least 2.6.10 but folks + that are auditing their logs closely may want to set it to a lower + priority. + +config ENABLE_WARN_DEPRECATED + bool "Enable __deprecated logic" + default y + help + Enable the __deprecated logic in the kernel build. + Disable this to suppress the "warning: 'foo' is deprecated + (declared at kernel/power/somefile.c:1234)" messages. + +config ENABLE_MUST_CHECK + bool "Enable __must_check logic" + default y + help + Enable the __must_check logic in the kernel build. Disable this to + suppress the "warning: ignoring return value of 'foo', declared with + attribute warn_unused_result" messages. + +config FRAME_WARN + int "Warn for stack frames larger than (needs gcc 4.4)" + range 0 8192 + default 1024 if !64BIT + default 2048 if 64BIT + help + Tell gcc to warn at build time for stack frames larger than this. + Setting this too low will cause a lot of warnings. + Setting it to 0 disables the warning. + Requires gcc 4.4 + +config MAGIC_SYSRQ + bool "Magic SysRq key" + depends on !UML + help + If you say Y here, you will have some control over the system even + if the system crashes for example during kernel debugging (e.g., you + will be able to flush the buffer cache to disk, reboot the system + immediately or dump some status information). This is accomplished + by pressing various keys while holding SysRq (Alt+PrintScreen). It + also works on a serial console (on PC hardware at least), if you + send a BREAK and then within 5 seconds a command keypress. The + keys are documented in <file:Documentation/sysrq.txt>. Don't say Y + unless you really know what this hack does. + +config STRIP_ASM_SYMS + bool "Strip assembler-generated symbols during link" + default n + help + Strip internal assembler-generated symbols during a link (symbols + that look like '.Lxxx') so they don't pollute the output of + get_wchan() and suchlike. + +config UNUSED_SYMBOLS + bool "Enable unused/obsolete exported symbols" + default y if X86 + help + Unused but exported symbols make the kernel needlessly bigger. For + that reason most of these unused exports will soon be removed. This + option is provided temporarily to provide a transition period in case + some external kernel module needs one of these symbols anyway. If you + encounter such a case in your module, consider if you are actually + using the right API. (rationale: since nobody in the kernel is using + this in a module, there is a pretty good chance it's actually the + wrong interface to use). If you really need the symbol, please send a + mail to the linux kernel mailing list mentioning the symbol and why + you really need it, and what the merge plan to the mainline kernel for + your module is. + +config DEBUG_FS + bool "Debug Filesystem" + help + debugfs is a virtual file system that kernel developers use to put + debugging files into. Enable this option to be able to read and + write to these files. + + For detailed documentation on the debugfs API, see + Documentation/DocBook/filesystems. + + If unsure, say N. + +config HEADERS_CHECK + bool "Run 'make headers_check' when building vmlinux" + depends on !UML + help + This option will extract the user-visible kernel headers whenever + building the kernel, and will run basic sanity checks on them to + ensure that exported files do not attempt to include files which + were not exported, etc. + + If you're making modifications to header files which are + relevant for userspace, say 'Y', and check the headers + exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in + your build tree), to make sure they're suitable. + +config DEBUG_SECTION_MISMATCH + bool "Enable full Section mismatch analysis" + help + The section mismatch analysis checks if there are illegal + references from one section to another section. + Linux will during link or during runtime drop some sections + and any use of code/data previously in these sections will + most likely result in an oops. + In the code functions and variables are annotated with + __init, __devinit etc. (see full list in include/linux/init.h) + which results in the code/data being placed in specific sections. + The section mismatch analysis is always done after a full + kernel build but enabling this option will in addition + do the following: + - Add the option -fno-inline-functions-called-once to gcc + When inlining a function annotated __init in a non-init + function we would lose the section information and thus + the analysis would not catch the illegal reference. + This option tells gcc to inline less but will also + result in a larger kernel. + - Run the section mismatch analysis for each module/built-in.o + When we run the section mismatch analysis on vmlinux.o we + lose valueble information about where the mismatch was + introduced. + Running the analysis for each module/built-in.o file + will tell where the mismatch happens much closer to the + source. The drawback is that we will report the same + mismatch at least twice. + - Enable verbose reporting from modpost to help solving + the section mismatches reported. + +config DEBUG_KERNEL + bool "Kernel debugging" + help + Say Y here if you are developing drivers or trying to debug and + identify kernel problems. + +config DEBUG_SHIRQ + bool "Debug shared IRQ handlers" + depends on DEBUG_KERNEL && GENERIC_HARDIRQS + help + Enable this to generate a spurious interrupt as soon as a shared + interrupt handler is registered, and just before one is deregistered. + Drivers ought to be able to handle interrupts coming in at those + points; some don't and need to be caught. + +config LOCKUP_DETECTOR + bool "Detect Hard and Soft Lockups" + depends on DEBUG_KERNEL && !S390 + help + Say Y here to enable the kernel to act as a watchdog to detect + hard and soft lockups. + + Softlockups are bugs that cause the kernel to loop in kernel + mode for more than 60 seconds, without giving other tasks a + chance to run. The current stack trace is displayed upon + detection and the system will stay locked up. + + Hardlockups are bugs that cause the CPU to loop in kernel mode + for more than 60 seconds, without letting other interrupts have a + chance to run. The current stack trace is displayed upon detection + and the system will stay locked up. + + The overhead should be minimal. A periodic hrtimer runs to + generate interrupts and kick the watchdog task every 10-12 seconds. + An NMI is generated every 60 seconds or so to check for hardlockups. + +config HARDLOCKUP_DETECTOR + def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \ + !ARCH_HAS_NMI_WATCHDOG + +config BOOTPARAM_HARDLOCKUP_PANIC + bool "Panic (Reboot) On Hard Lockups" + depends on LOCKUP_DETECTOR + help + Say Y here to enable the kernel to panic on "hard lockups", + which are bugs that cause the kernel to loop in kernel + mode with interrupts disabled for more than 60 seconds. + + Say N if unsure. + +config BOOTPARAM_HARDLOCKUP_PANIC_VALUE + int + depends on LOCKUP_DETECTOR + range 0 1 + default 0 if !BOOTPARAM_HARDLOCKUP_PANIC + default 1 if BOOTPARAM_HARDLOCKUP_PANIC + +config BOOTPARAM_SOFTLOCKUP_PANIC + bool "Panic (Reboot) On Soft Lockups" + depends on LOCKUP_DETECTOR + help + Say Y here to enable the kernel to panic on "soft lockups", + which are bugs that cause the kernel to loop in kernel + mode for more than 60 seconds, without giving other tasks a + chance to run. + + The panic can be used in combination with panic_timeout, + to cause the system to reboot automatically after a + lockup has been detected. This feature is useful for + high-availability systems that have uptime guarantees and + where a lockup must be resolved ASAP. + + Say N if unsure. + +config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE + int + depends on LOCKUP_DETECTOR + range 0 1 + default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC + default 1 if BOOTPARAM_SOFTLOCKUP_PANIC + +config DETECT_HUNG_TASK + bool "Detect Hung Tasks" + depends on DEBUG_KERNEL + default DETECT_SOFTLOCKUP + help + Say Y here to enable the kernel to detect "hung tasks", + which are bugs that cause the task to be stuck in + uninterruptible "D" state indefinitiley. + + When a hung task is detected, the kernel will print the + current stack trace (which you should report), but the + task will stay in uninterruptible state. If lockdep is + enabled then all held locks will also be reported. This + feature has negligible overhead. + +config DEFAULT_HUNG_TASK_TIMEOUT + int "Default timeout for hung task detection (in seconds)" + depends on DETECT_HUNG_TASK + default 120 + help + This option controls the default timeout (in seconds) used + to determine when a task has become non-responsive and should + be considered hung. + + It can be adjusted at runtime via the kernel.hung_task_timeout + sysctl or by writing a value to /proc/sys/kernel/hung_task_timeout. + + A timeout of 0 disables the check. The default is two minutes. + Keeping the default should be fine in most cases. + +config BOOTPARAM_HUNG_TASK_PANIC + bool "Panic (Reboot) On Hung Tasks" + depends on DETECT_HUNG_TASK + help + Say Y here to enable the kernel to panic on "hung tasks", + which are bugs that cause the kernel to leave a task stuck + in uninterruptible "D" state. + + The panic can be used in combination with panic_timeout, + to cause the system to reboot automatically after a + hung task has been detected. This feature is useful for + high-availability systems that have uptime guarantees and + where a hung tasks must be resolved ASAP. + + Say N if unsure. + +config BOOTPARAM_HUNG_TASK_PANIC_VALUE + int + depends on DETECT_HUNG_TASK + range 0 1 + default 0 if !BOOTPARAM_HUNG_TASK_PANIC + default 1 if BOOTPARAM_HUNG_TASK_PANIC + +config SCHED_DEBUG + bool "Collect scheduler debugging info" + depends on DEBUG_KERNEL && PROC_FS + default y + help + If you say Y here, the /proc/sched_debug file will be provided + that can help debug the scheduler. The runtime overhead of this + option is minimal. + +config SCHEDSTATS + bool "Collect scheduler statistics" + depends on DEBUG_KERNEL && PROC_FS + help + If you say Y here, additional code will be inserted into the + scheduler and related routines to collect statistics about + scheduler behavior and provide them in /proc/schedstat. These + stats may be useful for both tuning and debugging the scheduler + If you aren't debugging the scheduler or trying to tune a specific + application, you can say N to avoid the very slight overhead + this adds. + +config TIMER_STATS + bool "Collect kernel timers statistics" + depends on DEBUG_KERNEL && PROC_FS + help + If you say Y here, additional code will be inserted into the + timer routines to collect statistics about kernel timers being + reprogrammed. The statistics can be read from /proc/timer_stats. + The statistics collection is started by writing 1 to /proc/timer_stats, + writing 0 stops it. This feature is useful to collect information + about timer usage patterns in kernel and userspace. This feature + is lightweight if enabled in the kernel config but not activated + (it defaults to deactivated on bootup and will only be activated + if some application like powertop activates it explicitly). + +config DEBUG_OBJECTS + bool "Debug object operations" + depends on DEBUG_KERNEL + help + If you say Y here, additional code will be inserted into the + kernel to track the life time of various objects and validate + the operations on those objects. + +config DEBUG_OBJECTS_SELFTEST + bool "Debug objects selftest" + depends on DEBUG_OBJECTS + help + This enables the selftest of the object debug code. + +config DEBUG_OBJECTS_FREE + bool "Debug objects in freed memory" + depends on DEBUG_OBJECTS + help + This enables checks whether a k/v free operation frees an area + which contains an object which has not been deactivated + properly. This can make kmalloc/kfree-intensive workloads + much slower. + +config DEBUG_OBJECTS_TIMERS + bool "Debug timer objects" + depends on DEBUG_OBJECTS + help + If you say Y here, additional code will be inserted into the + timer routines to track the life time of timer objects and + validate the timer operations. + +config DEBUG_OBJECTS_WORK + bool "Debug work objects" + depends on DEBUG_OBJECTS + help + If you say Y here, additional code will be inserted into the + work queue routines to track the life time of work objects and + validate the work operations. + +config DEBUG_OBJECTS_RCU_HEAD + bool "Debug RCU callbacks objects" + depends on DEBUG_OBJECTS + help + Enable this to turn on debugging of RCU list heads (call_rcu() usage). + +config DEBUG_OBJECTS_PERCPU_COUNTER + bool "Debug percpu counter objects" + depends on DEBUG_OBJECTS + help + If you say Y here, additional code will be inserted into the + percpu counter routines to track the life time of percpu counter + objects and validate the percpu counter operations. + +config DEBUG_OBJECTS_ENABLE_DEFAULT + int "debug_objects bootup default value (0-1)" + range 0 1 + default "1" + depends on DEBUG_OBJECTS + help + Debug objects boot parameter default value + +config DEBUG_SLAB + bool "Debug slab memory allocations" + depends on DEBUG_KERNEL && SLAB && !KMEMCHECK + help + Say Y here to have the kernel do limited verification on memory + allocation as well as poisoning memory on free to catch use of freed + memory. This can make kmalloc/kfree-intensive workloads much slower. + +config DEBUG_SLAB_LEAK + bool "Memory leak debugging" + depends on DEBUG_SLAB + +config SLUB_DEBUG_ON + bool "SLUB debugging on by default" + depends on SLUB && SLUB_DEBUG && !KMEMCHECK + default n + help + Boot with debugging on by default. SLUB boots by default with + the runtime debug capabilities switched off. Enabling this is + equivalent to specifying the "slub_debug" parameter on boot. + There is no support for more fine grained debug control like + possible with slub_debug=xxx. SLUB debugging may be switched + off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying + "slub_debug=-". + +config SLUB_STATS + default n + bool "Enable SLUB performance statistics" + depends on SLUB && SYSFS + help + SLUB statistics are useful to debug SLUBs allocation behavior in + order find ways to optimize the allocator. This should never be + enabled for production use since keeping statistics slows down + the allocator by a few percentage points. The slabinfo command + supports the determination of the most active slabs to figure + out which slabs are relevant to a particular load. + Try running: slabinfo -DA + +config DEBUG_KMEMLEAK + bool "Kernel memory leak detector" + depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \ + (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE) + + select DEBUG_FS + select STACKTRACE if STACKTRACE_SUPPORT + select KALLSYMS + select CRC32 + help + Say Y here if you want to enable the memory leak + detector. The memory allocation/freeing is traced in a way + similar to the Boehm's conservative garbage collector, the + difference being that the orphan objects are not freed but + only shown in /sys/kernel/debug/kmemleak. Enabling this + feature will introduce an overhead to memory + allocations. See Documentation/kmemleak.txt for more + details. + + Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances + of finding leaks due to the slab objects poisoning. + + In order to access the kmemleak file, debugfs needs to be + mounted (usually at /sys/kernel/debug). + +config DEBUG_KMEMLEAK_EARLY_LOG_SIZE + int "Maximum kmemleak early log entries" + depends on DEBUG_KMEMLEAK + range 200 40000 + default 400 + help + Kmemleak must track all the memory allocations to avoid + reporting false positives. Since memory may be allocated or + freed before kmemleak is initialised, an early log buffer is + used to store these actions. If kmemleak reports "early log + buffer exceeded", please increase this value. + +config DEBUG_KMEMLEAK_TEST + tristate "Simple test for the kernel memory leak detector" + depends on DEBUG_KMEMLEAK && m + help + This option enables a module that explicitly leaks memory. + + If unsure, say N. + +config DEBUG_KMEMLEAK_DEFAULT_OFF + bool "Default kmemleak to off" + depends on DEBUG_KMEMLEAK + help + Say Y here to disable kmemleak by default. It can then be enabled + on the command line via kmemleak=on. + +config DEBUG_PREEMPT + bool "Debug preemptible kernel" + depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT + default y + help + If you say Y here then the kernel will use a debug variant of the + commonly used smp_processor_id() function and will print warnings + if kernel code uses it in a preemption-unsafe way. Also, the kernel + will detect preemption count underflows. + +config DEBUG_RT_MUTEXES + bool "RT Mutex debugging, deadlock detection" + depends on DEBUG_KERNEL && RT_MUTEXES + help + This allows rt mutex semantics violations and rt mutex related + deadlocks (lockups) to be detected and reported automatically. + +config DEBUG_PI_LIST + bool + default y + depends on DEBUG_RT_MUTEXES + +config RT_MUTEX_TESTER + bool "Built-in scriptable tester for rt-mutexes" + depends on DEBUG_KERNEL && RT_MUTEXES + help + This option enables a rt-mutex tester. + +config DEBUG_SPINLOCK + bool "Spinlock and rw-lock debugging: basic checks" + depends on DEBUG_KERNEL + help + Say Y here and build SMP to catch missing spinlock initialization + and certain other kinds of spinlock errors commonly made. This is + best used in conjunction with the NMI watchdog so that spinlock + deadlocks are also debuggable. + +config DEBUG_MUTEXES + bool "Mutex debugging: basic checks" + depends on DEBUG_KERNEL + help + This feature allows mutex semantics violations to be detected and + reported. + +config DEBUG_LOCK_ALLOC + bool "Lock debugging: detect incorrect freeing of live locks" + depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select LOCKDEP + help + This feature will check whether any held lock (spinlock, rwlock, + mutex or rwsem) is incorrectly freed by the kernel, via any of the + memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), + vfree(), etc.), whether a live lock is incorrectly reinitialized via + spin_lock_init()/mutex_init()/etc., or whether there is any lock + held during task exit. + +config PROVE_LOCKING + bool "Lock debugging: prove locking correctness" + depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select LOCKDEP + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_LOCK_ALLOC + select TRACE_IRQFLAGS + default n + help + This feature enables the kernel to prove that all locking + that occurs in the kernel runtime is mathematically + correct: that under no circumstance could an arbitrary (and + not yet triggered) combination of observed locking + sequences (on an arbitrary number of CPUs, running an + arbitrary number of tasks and interrupt contexts) cause a + deadlock. + + In short, this feature enables the kernel to report locking + related deadlocks before they actually occur. + + The proof does not depend on how hard and complex a + deadlock scenario would be to trigger: how many + participant CPUs, tasks and irq-contexts would be needed + for it to trigger. The proof also does not depend on + timing: if a race and a resulting deadlock is possible + theoretically (no matter how unlikely the race scenario + is), it will be proven so and will immediately be + reported by the kernel (once the event is observed that + makes the deadlock theoretically possible). + + If a deadlock is impossible (i.e. the locking rules, as + observed by the kernel, are mathematically correct), the + kernel reports nothing. + + NOTE: this feature can also be enabled for rwlocks, mutexes + and rwsems - in which case all dependencies between these + different locking variants are observed and mapped too, and + the proof of observed correctness is also maintained for an + arbitrary combination of these separate locking variants. + + For more details, see Documentation/lockdep-design.txt. + +config PROVE_RCU + bool "RCU debugging: prove RCU correctness" + depends on PROVE_LOCKING + default n + help + This feature enables lockdep extensions that check for correct + use of RCU APIs. This is currently under development. Say Y + if you want to debug RCU usage or help work on the PROVE_RCU + feature. + + Say N if you are unsure. + +config PROVE_RCU_REPEATEDLY + bool "RCU debugging: don't disable PROVE_RCU on first splat" + depends on PROVE_RCU + default n + help + By itself, PROVE_RCU will disable checking upon issuing the + first warning (or "splat"). This feature prevents such + disabling, allowing multiple RCU-lockdep warnings to be printed + on a single reboot. + + Say Y to allow multiple RCU-lockdep warnings per boot. + + Say N if you are unsure. + +config SPARSE_RCU_POINTER + bool "RCU debugging: sparse-based checks for pointer usage" + default n + help + This feature enables the __rcu sparse annotation for + RCU-protected pointers. This annotation will cause sparse + to flag any non-RCU used of annotated pointers. This can be + helpful when debugging RCU usage. Please note that this feature + is not intended to enforce code cleanliness; it is instead merely + a debugging aid. + + Say Y to make sparse flag questionable use of RCU-protected pointers + + Say N if you are unsure. + +config LOCKDEP + bool + depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select STACKTRACE + select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE + select KALLSYMS + select KALLSYMS_ALL + +config LOCK_STAT + bool "Lock usage statistics" + depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select LOCKDEP + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_LOCK_ALLOC + default n + help + This feature enables tracking lock contention points + + For more details, see Documentation/lockstat.txt + + This also enables lock events required by "perf lock", + subcommand of perf. + If you want to use "perf lock", you also need to turn on + CONFIG_EVENT_TRACING. + + CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. + (CONFIG_LOCKDEP defines "acquire" and "release" events.) + +config DEBUG_LOCKDEP + bool "Lock dependency engine debugging" + depends on DEBUG_KERNEL && LOCKDEP + help + If you say Y here, the lock dependency engine will do + additional runtime checks to debug itself, at the price + of more runtime overhead. + +config TRACE_IRQFLAGS + bool + help + Enables hooks to interrupt enabling and disabling for + either tracing or lock debugging. + +config DEBUG_SPINLOCK_SLEEP + bool "Spinlock debugging: sleep-inside-spinlock checking" + depends on DEBUG_KERNEL + help + If you say Y here, various routines which may sleep will become very + noisy if they are called with a spinlock held. + +config DEBUG_LOCKING_API_SELFTESTS + bool "Locking API boot-time self-tests" + depends on DEBUG_KERNEL + help + Say Y here if you want the kernel to run a short self-test during + bootup. The self-test checks whether common types of locking bugs + are detected by debugging mechanisms or not. (if you disable + lock debugging then those bugs wont be detected of course.) + The following locking APIs are covered: spinlocks, rwlocks, + mutexes and rwsems. + +config STACKTRACE + bool "Stacktrace" + depends on STACKTRACE_SUPPORT + default y + +config DEBUG_STACK_USAGE + bool "Stack utilization instrumentation" + depends on DEBUG_KERNEL + help + Enables the display of the minimum amount of free stack which each + task has ever had available in the sysrq-T and sysrq-P debug output. + + This option will slow down process creation somewhat. + +config DEBUG_KOBJECT + bool "kobject debugging" + depends on DEBUG_KERNEL + help + If you say Y here, some extra kobject debugging messages will be sent + to the syslog. + +config DEBUG_HIGHMEM + bool "Highmem debugging" + depends on DEBUG_KERNEL && HIGHMEM + help + This options enables addition error checking for high memory systems. + Disable for production systems. + +config DEBUG_BUGVERBOSE + bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT + depends on BUG + depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ + FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE + default y + help + Say Y here to make BUG() panics output the file name and line number + of the BUG call as well as the EIP and oops trace. This aids + debugging but costs about 70-100K of memory. + +config DEBUG_INFO + bool "Compile the kernel with debug info" + depends on DEBUG_KERNEL + help + If you say Y here the resulting kernel image will include + debugging info resulting in a larger kernel image. + This adds debug symbols to the kernel and modules (gcc -g), and + is needed if you intend to use kernel crashdump or binary object + tools like crash, kgdb, LKCD, gdb, etc on the kernel. + Say Y here only if you plan to debug the kernel. + + If unsure, say N. + +config DEBUG_INFO_REDUCED + bool "Reduce debugging information" + depends on DEBUG_INFO + help + If you say Y here gcc is instructed to generate less debugging + information for structure types. This means that tools that + need full debugging information (like kgdb or systemtap) won't + be happy. But if you merely need debugging information to + resolve line numbers there is no loss. Advantage is that + build directory object sizes shrink dramatically over a full + DEBUG_INFO build and compile times are reduced too. + Only works with newer gcc versions. + +config DEBUG_VM + bool "Debug VM" + depends on DEBUG_KERNEL + help + Enable this to turn on extended checks in the virtual-memory system + that may impact performance. + + If unsure, say N. + +config DEBUG_VIRTUAL + bool "Debug VM translations" + depends on DEBUG_KERNEL && X86 + help + Enable some costly sanity checks in virtual to page code. This can + catch mistakes with virt_to_page() and friends. + + If unsure, say N. + +config DEBUG_NOMMU_REGIONS + bool "Debug the global anon/private NOMMU mapping region tree" + depends on DEBUG_KERNEL && !MMU + help + This option causes the global tree of anonymous and private mapping + regions to be regularly checked for invalid topology. + +config DEBUG_WRITECOUNT + bool "Debug filesystem writers count" + depends on DEBUG_KERNEL + help + Enable this to catch wrong use of the writers count in struct + vfsmount. This will increase the size of each file struct by + 32 bits. + + If unsure, say N. + +config DEBUG_MEMORY_INIT + bool "Debug memory initialisation" if EXPERT + default !EXPERT + help + Enable this for additional checks during memory initialisation. + The sanity checks verify aspects of the VM such as the memory model + and other information provided by the architecture. Verbose + information will be printed at KERN_DEBUG loglevel depending + on the mminit_loglevel= command-line option. + + If unsure, say Y + +config DEBUG_LIST + bool "Debug linked list manipulation" + depends on DEBUG_KERNEL + help + Enable this to turn on extended checks in the linked-list + walking routines. + + If unsure, say N. + +config TEST_LIST_SORT + bool "Linked list sorting test" + depends on DEBUG_KERNEL + help + Enable this to turn on 'list_sort()' function test. This test is + executed only once during system boot, so affects only boot time. + + If unsure, say N. + +config DEBUG_SG + bool "Debug SG table operations" + depends on DEBUG_KERNEL + help + Enable this to turn on checks on scatter-gather tables. This can + help find problems with drivers that do not properly initialize + their sg tables. + + If unsure, say N. + +config DEBUG_NOTIFIERS + bool "Debug notifier call chains" + depends on DEBUG_KERNEL + help + Enable this to turn on sanity checking for notifier call chains. + This is most useful for kernel developers to make sure that + modules properly unregister themselves from notifier chains. + This is a relatively cheap check but if you care about maximum + performance, say N. + +config DEBUG_CREDENTIALS + bool "Debug credential management" + depends on DEBUG_KERNEL + help + Enable this to turn on some debug checking for credential + management. The additional code keeps track of the number of + pointers from task_structs to any given cred struct, and checks to + see that this number never exceeds the usage count of the cred + struct. + + Furthermore, if SELinux is enabled, this also checks that the + security pointer in the cred struct is never seen to be invalid. + + If unsure, say N. + +# +# Select this config option from the architecture Kconfig, if it +# it is preferred to always offer frame pointers as a config +# option on the architecture (regardless of KERNEL_DEBUG): +# +config ARCH_WANT_FRAME_POINTERS + bool + help + +config FRAME_POINTER + bool "Compile the kernel with frame pointers" + depends on DEBUG_KERNEL && \ + (CRIS || M68K || FRV || UML || \ + AVR32 || SUPERH || BLACKFIN || MN10300) || \ + ARCH_WANT_FRAME_POINTERS + default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS + help + If you say Y here the resulting kernel image will be slightly + larger and slower, but it gives very useful debugging information + in case of kernel bugs. (precise oopses/stacktraces/warnings) + +config BOOT_PRINTK_DELAY + bool "Delay each boot printk message by N milliseconds" + depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY + help + This build option allows you to read kernel boot messages + by inserting a short delay after each one. The delay is + specified in milliseconds on the kernel command line, + using "boot_delay=N". + + It is likely that you would also need to use "lpj=M" to preset + the "loops per jiffie" value. + See a previous boot log for the "lpj" value to use for your + system, and then set "lpj=M" before setting "boot_delay=N". + NOTE: Using this option may adversely affect SMP systems. + I.e., processors other than the first one may not boot up. + BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect + what it believes to be lockup conditions. + +config RCU_TORTURE_TEST + tristate "torture tests for RCU" + depends on DEBUG_KERNEL + default n + help + This option provides a kernel module that runs torture tests + on the RCU infrastructure. The kernel module may be built + after the fact on the running kernel to be tested, if desired. + + Say Y here if you want RCU torture tests to be built into + the kernel. + Say M if you want the RCU torture tests to build as a module. + Say N if you are unsure. + +config RCU_TORTURE_TEST_RUNNABLE + bool "torture tests for RCU runnable by default" + depends on RCU_TORTURE_TEST = y + default n + help + This option provides a way to build the RCU torture tests + directly into the kernel without them starting up at boot + time. You can use /proc/sys/kernel/rcutorture_runnable + to manually override this setting. This /proc file is + available only when the RCU torture tests have been built + into the kernel. + + Say Y here if you want the RCU torture tests to start during + boot (you probably don't). + Say N here if you want the RCU torture tests to start only + after being manually enabled via /proc. + +config RCU_CPU_STALL_TIMEOUT + int "RCU CPU stall timeout in seconds" + depends on TREE_RCU || TREE_PREEMPT_RCU + range 3 300 + default 60 + help + If a given RCU grace period extends more than the specified + number of seconds, a CPU stall warning is printed. If the + RCU grace period persists, additional CPU stall warnings are + printed at more widely spaced intervals. + +config RCU_CPU_STALL_VERBOSE + bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR" + depends on TREE_PREEMPT_RCU + default y + help + This option causes RCU to printk detailed per-task information + for any tasks that are stalling the current RCU grace period. + + Say N if you are unsure. + + Say Y if you want to enable such checks. + +config KPROBES_SANITY_TEST + bool "Kprobes sanity tests" + depends on DEBUG_KERNEL + depends on KPROBES + default n + help + This option provides for testing basic kprobes functionality on + boot. A sample kprobe, jprobe and kretprobe are inserted and + verified for functionality. + + Say N if you are unsure. + +config BACKTRACE_SELF_TEST + tristate "Self test for the backtrace code" + depends on DEBUG_KERNEL + default n + help + This option provides a kernel module that can be used to test + the kernel stack backtrace code. This option is not useful + for distributions or general kernels, but only for kernel + developers working on architecture code. + + Note that if you want to also test saved backtraces, you will + have to enable STACKTRACE as well. + + Say N if you are unsure. + +config DEBUG_BLOCK_EXT_DEVT + bool "Force extended block device numbers and spread them" + depends on DEBUG_KERNEL + depends on BLOCK + default n + help + BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON + SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT + YOU ARE DOING. Distros, please enable this and fix whatever + is broken. + + Conventionally, block device numbers are allocated from + predetermined contiguous area. However, extended block area + may introduce non-contiguous block device numbers. This + option forces most block device numbers to be allocated from + the extended space and spreads them to discover kernel or + userland code paths which assume predetermined contiguous + device number allocation. + + Note that turning on this debug option shuffles all the + device numbers for all IDE and SCSI devices including libata + ones, so root partition specified using device number + directly (via rdev or root=MAJ:MIN) won't work anymore. + Textual device names (root=/dev/sdXn) will continue to work. + + Say N if you are unsure. + +config DEBUG_FORCE_WEAK_PER_CPU + bool "Force weak per-cpu definitions" + depends on DEBUG_KERNEL + help + s390 and alpha require percpu variables in modules to be + defined weak to work around addressing range issue which + puts the following two restrictions on percpu variable + definitions. + + 1. percpu symbols must be unique whether static or not + 2. percpu variables can't be defined inside a function + + To ensure that generic code follows the above rules, this + option forces all percpu variables to be defined as weak. + +config DEBUG_PER_CPU_MAPS + bool "Debug access to per_cpu maps" + depends on DEBUG_KERNEL + depends on SMP + help + Say Y to verify that the per_cpu map being accessed has + been set up. This adds a fair amount of code to kernel memory + and decreases performance. + + Say N if unsure. + +config LKDTM + tristate "Linux Kernel Dump Test Tool Module" + depends on DEBUG_FS + depends on BLOCK + default n + help + This module enables testing of the different dumping mechanisms by + inducing system failures at predefined crash points. + If you don't need it: say N + Choose M here to compile this code as a module. The module will be + called lkdtm. + + Documentation on how to use the module can be found in + Documentation/fault-injection/provoke-crashes.txt + +config CPU_NOTIFIER_ERROR_INJECT + tristate "CPU notifier error injection module" + depends on HOTPLUG_CPU && DEBUG_KERNEL + help + This option provides a kernel module that can be used to test + the error handling of the cpu notifiers + + To compile this code as a module, choose M here: the module will + be called cpu-notifier-error-inject. + + If unsure, say N. + +config FAULT_INJECTION + bool "Fault-injection framework" + depends on DEBUG_KERNEL + help + Provide fault-injection framework. + For more details, see Documentation/fault-injection/. + +config FAILSLAB + bool "Fault-injection capability for kmalloc" + depends on FAULT_INJECTION + depends on SLAB || SLUB + help + Provide fault-injection capability for kmalloc. + +config FAIL_PAGE_ALLOC + bool "Fault-injection capabilitiy for alloc_pages()" + depends on FAULT_INJECTION + help + Provide fault-injection capability for alloc_pages(). + +config FAIL_MAKE_REQUEST + bool "Fault-injection capability for disk IO" + depends on FAULT_INJECTION && BLOCK + help + Provide fault-injection capability for disk IO. + +config FAIL_IO_TIMEOUT + bool "Fault-injection capability for faking disk interrupts" + depends on FAULT_INJECTION && BLOCK + help + Provide fault-injection capability on end IO handling. This + will make the block layer "forget" an interrupt as configured, + thus exercising the error handling. + + Only works with drivers that use the generic timeout handling, + for others it wont do anything. + +config FAULT_INJECTION_DEBUG_FS + bool "Debugfs entries for fault-injection capabilities" + depends on FAULT_INJECTION && SYSFS && DEBUG_FS + help + Enable configuration of fault-injection capabilities via debugfs. + +config FAULT_INJECTION_STACKTRACE_FILTER + bool "stacktrace filter for fault-injection capabilities" + depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT + depends on !X86_64 + select STACKTRACE + select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE + help + Provide stacktrace filter for fault-injection capabilities + +config LATENCYTOP + bool "Latency measuring infrastructure" + depends on HAVE_LATENCYTOP_SUPPORT + depends on DEBUG_KERNEL + depends on STACKTRACE_SUPPORT + depends on PROC_FS + select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE + select KALLSYMS + select KALLSYMS_ALL + select STACKTRACE + select SCHEDSTATS + select SCHED_DEBUG + help + Enable this option if you want to use the LatencyTOP tool + to find out which userspace is blocking on what kernel operations. + +config SYSCTL_SYSCALL_CHECK + bool "Sysctl checks" + depends on SYSCTL + ---help--- + sys_sysctl uses binary paths that have been found challenging + to properly maintain and use. This enables checks that help + you to keep things correct. + +source mm/Kconfig.debug +source kernel/trace/Kconfig + +config PROVIDE_OHCI1394_DMA_INIT + bool "Remote debugging over FireWire early on boot" + depends on PCI && X86 + help + If you want to debug problems which hang or crash the kernel early + on boot and the crashing machine has a FireWire port, you can use + this feature to remotely access the memory of the crashed machine + over FireWire. This employs remote DMA as part of the OHCI1394 + specification which is now the standard for FireWire controllers. + + With remote DMA, you can monitor the printk buffer remotely using + firescope and access all memory below 4GB using fireproxy from gdb. + Even controlling a kernel debugger is possible using remote DMA. + + Usage: + + If ohci1394_dma=early is used as boot parameter, it will initialize + all OHCI1394 controllers which are found in the PCI config space. + + As all changes to the FireWire bus such as enabling and disabling + devices cause a bus reset and thereby disable remote DMA for all + devices, be sure to have the cable plugged and FireWire enabled on + the debugging host before booting the debug target for debugging. + + This code (~1k) is freed after boot. By then, the firewire stack + in charge of the OHCI-1394 controllers should be used instead. + + See Documentation/debugging-via-ohci1394.txt for more information. + +config FIREWIRE_OHCI_REMOTE_DMA + bool "Remote debugging over FireWire with firewire-ohci" + depends on FIREWIRE_OHCI + help + This option lets you use the FireWire bus for remote debugging + with help of the firewire-ohci driver. It enables unfiltered + remote DMA in firewire-ohci. + See Documentation/debugging-via-ohci1394.txt for more information. + + If unsure, say N. + +config BUILD_DOCSRC + bool "Build targets in Documentation/ tree" + depends on HEADERS_CHECK + help + This option attempts to build objects from the source files in the + kernel Documentation/ tree. + + Say N if you are unsure. + +config DYNAMIC_DEBUG + bool "Enable dynamic printk() support" + default n + depends on PRINTK + depends on DEBUG_FS + help + + Compiles debug level messages into the kernel, which would not + otherwise be available at runtime. These messages can then be + enabled/disabled based on various levels of scope - per source file, + function, module, format string, and line number. This mechanism + implicitly enables all pr_debug() and dev_dbg() calls. The impact of + this compile option is a larger kernel text size of about 2%. + + Usage: + + Dynamic debugging is controlled via the 'dynamic_debug/control' file, + which is contained in the 'debugfs' filesystem. Thus, the debugfs + filesystem must first be mounted before making use of this feature. + We refer the control file as: <debugfs>/dynamic_debug/control. This + file contains a list of the debug statements that can be enabled. The + format for each line of the file is: + + filename:lineno [module]function flags format + + filename : source file of the debug statement + lineno : line number of the debug statement + module : module that contains the debug statement + function : function that contains the debug statement + flags : 'p' means the line is turned 'on' for printing + format : the format used for the debug statement + + From a live system: + + nullarbor:~ # cat <debugfs>/dynamic_debug/control + # filename:lineno [module]function flags format + fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" + fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" + fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" + + Example usage: + + // enable the message at line 1603 of file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + <debugfs>/dynamic_debug/control + + // enable all the messages in file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c +p' > + <debugfs>/dynamic_debug/control + + // enable all the messages in the NFS server module + nullarbor:~ # echo -n 'module nfsd +p' > + <debugfs>/dynamic_debug/control + + // enable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process +p' > + <debugfs>/dynamic_debug/control + + // disable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process -p' > + <debugfs>/dynamic_debug/control + + See Documentation/dynamic-debug-howto.txt for additional information. + +config DMA_API_DEBUG + bool "Enable debugging of DMA-API usage" + depends on HAVE_DMA_API_DEBUG + help + Enable this option to debug the use of the DMA API by device drivers. + With this option you will be able to detect common bugs in device + drivers like double-freeing of DMA mappings or freeing mappings that + were never allocated. + This option causes a performance degredation. Use only if you want + to debug device drivers. If unsure, say N. + +config ATOMIC64_SELFTEST + bool "Perform an atomic64_t self-test at boot" + help + Enable this option to test the atomic64_t functions at boot. + + If unsure, say N. + +config ASYNC_RAID6_TEST + tristate "Self test for hardware accelerated raid6 recovery" + depends on ASYNC_RAID6_RECOV + select ASYNC_MEMCPY + ---help--- + This is a one-shot self test that permutes through the + recovery of all the possible two disk failure scenarios for a + N-disk array. Recovery is performed with the asynchronous + raid6 recovery routines, and will optionally use an offload + engine if one is available. + + If unsure, say N. + +source "samples/Kconfig" + +source "lib/Kconfig.kgdb" + +source "lib/Kconfig.kmemcheck" + +config TEST_KSTRTOX + tristate "Test kstrto*() family of functions at runtime" |