diff options
Diffstat (limited to 'lib/Kconfig.debug')
| -rw-r--r-- | lib/Kconfig.debug | 143 |
1 files changed, 130 insertions, 13 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 5330911ebd30..e5889b1a33ff 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -23,6 +23,22 @@ config MAGIC_SYSRQ keys are documented in <file:Documentation/sysrq.txt>. Don't say Y unless you really know what this hack does. +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_KERNEL bool "Kernel debugging" help @@ -32,7 +48,7 @@ config DEBUG_KERNEL config LOG_BUF_SHIFT int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL range 12 21 - default 17 if S390 + default 17 if S390 || LOCKDEP default 16 if X86_NUMAQ || IA64 default 15 if SMP default 14 @@ -91,7 +107,7 @@ config DEBUG_SLAB_LEAK config DEBUG_PREEMPT bool "Debug preemptible kernel" - depends on DEBUG_KERNEL && PREEMPT + 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 @@ -99,14 +115,6 @@ config DEBUG_PREEMPT if kernel code uses it in a preemption-unsafe way. Also, the kernel will detect preemption count underflows. -config DEBUG_MUTEXES - bool "Mutex debugging, deadlock detection" - default n - depends on DEBUG_KERNEL - help - This allows mutex semantics violations and mutex related deadlocks - (lockups) to be detected and reported automatically. - config DEBUG_RT_MUTEXES bool "RT Mutex debugging, deadlock detection" depends on DEBUG_KERNEL && RT_MUTEXES @@ -126,7 +134,7 @@ config RT_MUTEX_TESTER This option enables a rt-mutex tester. config DEBUG_SPINLOCK - bool "Spinlock debugging" + bool "Spinlock and rw-lock debugging: basic checks" depends on DEBUG_KERNEL help Say Y here and build SMP to catch missing spinlock initialization @@ -134,13 +142,122 @@ config DEBUG_SPINLOCK 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_RWSEMS + bool "RW-sem debugging: basic checks" + depends on DEBUG_KERNEL + help + This feature allows read-write semaphore semantics violations to + be detected and reported. + +config DEBUG_LOCK_ALLOC + bool "Lock debugging: detect incorrect freeing of live locks" + depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_RWSEMS + 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 TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select LOCKDEP + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_RWSEMS + select DEBUG_LOCK_ALLOC + 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 LOCKDEP + bool + depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select STACKTRACE + select FRAME_POINTER + select KALLSYMS + select KALLSYMS_ALL + +config DEBUG_LOCKDEP + bool "Lock dependency engine debugging" + depends on 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 + default y + depends on TRACE_IRQFLAGS_SUPPORT + depends on PROVE_LOCKING + config DEBUG_SPINLOCK_SLEEP - bool "Sleep-inside-spinlock checking" + 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 + depends on STACKTRACE_SUPPORT + config DEBUG_KOBJECT bool "kobject debugging" depends on DEBUG_KERNEL @@ -196,7 +313,7 @@ config DEBUG_VM config FRAME_POINTER bool "Compile the kernel with frame pointers" - depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML) + depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390) default y if DEBUG_INFO && UML help If you say Y here the resulting kernel image will be slightly larger |