X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2FKconfig.debug;h=b0f5ca72599fee5f4ed868457a85c39b5f6e57ef;hb=b98adfccdf5f8dd34ae56a2d5adbe2c030bd4674;hp=16021b09c1848bde59c572568f108ca8a91f6484;hpb=cae2ed9aa573415c6e5de9a09b7ff0d74af793bc;p=linux-2.6 diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 16021b09c1..b0f5ca7259 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -8,6 +8,13 @@ config PRINTK_TIME operations. This is useful for identifying long delays in kernel startup. +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 MAGIC_SYSRQ bool "Magic SysRq key" @@ -48,7 +55,7 @@ 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 @@ -134,7 +141,7 @@ 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 @@ -142,8 +149,103 @@ 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 DEBUG_KERNEL && 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 DEBUG_KERNEL && 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 DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select STACKTRACE + select FRAME_POINTER if !X86 + select KALLSYMS + select KALLSYMS_ALL + +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 + depends on DEBUG_KERNEL + 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 @@ -162,6 +264,7 @@ config DEBUG_LOCKING_API_SELFTESTS config STACKTRACE bool + depends on DEBUG_KERNEL depends on STACKTRACE_SUPPORT config DEBUG_KOBJECT @@ -181,7 +284,7 @@ config DEBUG_HIGHMEM config DEBUG_BUGVERBOSE bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED depends on BUG - depends on ARM || ARM26 || M32R || M68K || SPARC32 || SPARC64 || X86_32 || FRV + depends on ARM || ARM26 || AVR32 || M32R || M68K || SPARC32 || SPARC64 || X86_32 || FRV || SUPERH default !EMBEDDED help Say Y here to make BUG() panics output the file name and line number @@ -219,7 +322,7 @@ config DEBUG_VM config FRAME_POINTER bool "Compile the kernel with frame pointers" - depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390) + depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || AVR32 || SUPERH) default y if DEBUG_INFO && UML help If you say Y here the resulting kernel image will be slightly larger