From 9a11b49a805665e13a56aa067afaf81d43ec1514 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:33 -0700 Subject: [PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/spinlock_debug.c | 62 ++++++++++++++++++++++------------------------------ 1 file changed, 26 insertions(+), 36 deletions(-) (limited to 'lib/spinlock_debug.c') diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c index 93c15ee3f8ea..3de2ccf48ac6 100644 --- a/lib/spinlock_debug.c +++ b/lib/spinlock_debug.c @@ -8,38 +8,35 @@ #include #include +#include #include +#include static void spin_bug(spinlock_t *lock, const char *msg) { - static long print_once = 1; struct task_struct *owner = NULL; - if (xchg(&print_once, 0)) { - if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) - owner = lock->owner; - printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", - msg, raw_smp_processor_id(), - current->comm, current->pid); - printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " - ".owner_cpu: %d\n", - lock, lock->magic, - owner ? owner->comm : "", - owner ? owner->pid : -1, - lock->owner_cpu); - dump_stack(); -#ifdef CONFIG_SMP - /* - * We cannot continue on SMP: - */ -// panic("bad locking"); -#endif - } + if (!debug_locks_off()) + return; + + if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) + owner = lock->owner; + printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", + msg, raw_smp_processor_id(), + current->comm, current->pid); + printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " + ".owner_cpu: %d\n", + lock, lock->magic, + owner ? owner->comm : "", + owner ? owner->pid : -1, + lock->owner_cpu); + dump_stack(); } #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) -static inline void debug_spin_lock_before(spinlock_t *lock) +static inline void +debug_spin_lock_before(spinlock_t *lock) { SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); SPIN_BUG_ON(lock->owner == current, lock, "recursion"); @@ -118,20 +115,13 @@ void _raw_spin_unlock(spinlock_t *lock) static void rwlock_bug(rwlock_t *lock, const char *msg) { - static long print_once = 1; - - if (xchg(&print_once, 0)) { - printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", - msg, raw_smp_processor_id(), current->comm, - current->pid, lock); - dump_stack(); -#ifdef CONFIG_SMP - /* - * We cannot continue on SMP: - */ - panic("bad locking"); -#endif - } + if (!debug_locks_off()) + return; + + printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", + msg, raw_smp_processor_id(), current->comm, + current->pid, lock); + dump_stack(); } #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) -- cgit v1.2.3