diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Makefile | 2 | ||||
-rw-r--r-- | lib/debug_locks.c | 45 | ||||
-rw-r--r-- | lib/spinlock_debug.c | 62 |
3 files changed, 72 insertions, 37 deletions
diff --git a/lib/Makefile b/lib/Makefile index 10c13c9d7824..4f5d01922f82 100644 --- a/lib/Makefile +++ b/lib/Makefile | |||
@@ -11,7 +11,7 @@ lib-$(CONFIG_SMP) += cpumask.o | |||
11 | 11 | ||
12 | lib-y += kobject.o kref.o kobject_uevent.o klist.o | 12 | lib-y += kobject.o kref.o kobject_uevent.o klist.o |
13 | 13 | ||
14 | obj-y += sort.o parser.o halfmd4.o iomap_copy.o | 14 | obj-y += sort.o parser.o halfmd4.o iomap_copy.o debug_locks.o |
15 | 15 | ||
16 | ifeq ($(CONFIG_DEBUG_KOBJECT),y) | 16 | ifeq ($(CONFIG_DEBUG_KOBJECT),y) |
17 | CFLAGS_kobject.o += -DDEBUG | 17 | CFLAGS_kobject.o += -DDEBUG |
diff --git a/lib/debug_locks.c b/lib/debug_locks.c new file mode 100644 index 000000000000..0ef01d14727c --- /dev/null +++ b/lib/debug_locks.c | |||
@@ -0,0 +1,45 @@ | |||
1 | /* | ||
2 | * lib/debug_locks.c | ||
3 | * | ||
4 | * Generic place for common debugging facilities for various locks: | ||
5 | * spinlocks, rwlocks, mutexes and rwsems. | ||
6 | * | ||
7 | * Started by Ingo Molnar: | ||
8 | * | ||
9 | * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | ||
10 | */ | ||
11 | #include <linux/rwsem.h> | ||
12 | #include <linux/mutex.h> | ||
13 | #include <linux/module.h> | ||
14 | #include <linux/spinlock.h> | ||
15 | #include <linux/debug_locks.h> | ||
16 | |||
17 | /* | ||
18 | * We want to turn all lock-debugging facilities on/off at once, | ||
19 | * via a global flag. The reason is that once a single bug has been | ||
20 | * detected and reported, there might be cascade of followup bugs | ||
21 | * that would just muddy the log. So we report the first one and | ||
22 | * shut up after that. | ||
23 | */ | ||
24 | int debug_locks = 1; | ||
25 | |||
26 | /* | ||
27 | * The locking-testsuite uses <debug_locks_silent> to get a | ||
28 | * 'silent failure': nothing is printed to the console when | ||
29 | * a locking bug is detected. | ||
30 | */ | ||
31 | int debug_locks_silent; | ||
32 | |||
33 | /* | ||
34 | * Generic 'turn off all lock debugging' function: | ||
35 | */ | ||
36 | int debug_locks_off(void) | ||
37 | { | ||
38 | if (xchg(&debug_locks, 0)) { | ||
39 | if (!debug_locks_silent) { | ||
40 | console_verbose(); | ||
41 | return 1; | ||
42 | } | ||
43 | } | ||
44 | return 0; | ||
45 | } | ||
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 @@ | |||
8 | 8 | ||
9 | #include <linux/spinlock.h> | 9 | #include <linux/spinlock.h> |
10 | #include <linux/interrupt.h> | 10 | #include <linux/interrupt.h> |
11 | #include <linux/debug_locks.h> | ||
11 | #include <linux/delay.h> | 12 | #include <linux/delay.h> |
13 | #include <linux/module.h> | ||
12 | 14 | ||
13 | static void spin_bug(spinlock_t *lock, const char *msg) | 15 | static void spin_bug(spinlock_t *lock, const char *msg) |
14 | { | 16 | { |
15 | static long print_once = 1; | ||
16 | struct task_struct *owner = NULL; | 17 | struct task_struct *owner = NULL; |
17 | 18 | ||
18 | if (xchg(&print_once, 0)) { | 19 | if (!debug_locks_off()) |
19 | if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) | 20 | return; |
20 | owner = lock->owner; | 21 | |
21 | printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", | 22 | if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) |
22 | msg, raw_smp_processor_id(), | 23 | owner = lock->owner; |
23 | current->comm, current->pid); | 24 | printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", |
24 | printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " | 25 | msg, raw_smp_processor_id(), |
25 | ".owner_cpu: %d\n", | 26 | current->comm, current->pid); |
26 | lock, lock->magic, | 27 | printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " |
27 | owner ? owner->comm : "<none>", | 28 | ".owner_cpu: %d\n", |
28 | owner ? owner->pid : -1, | 29 | lock, lock->magic, |
29 | lock->owner_cpu); | 30 | owner ? owner->comm : "<none>", |
30 | dump_stack(); | 31 | owner ? owner->pid : -1, |
31 | #ifdef CONFIG_SMP | 32 | lock->owner_cpu); |
32 | /* | 33 | dump_stack(); |
33 | * We cannot continue on SMP: | ||
34 | */ | ||
35 | // panic("bad locking"); | ||
36 | #endif | ||
37 | } | ||
38 | } | 34 | } |
39 | 35 | ||
40 | #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) | 36 | #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) |
41 | 37 | ||
42 | static inline void debug_spin_lock_before(spinlock_t *lock) | 38 | static inline void |
39 | debug_spin_lock_before(spinlock_t *lock) | ||
43 | { | 40 | { |
44 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | 41 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); |
45 | SPIN_BUG_ON(lock->owner == current, lock, "recursion"); | 42 | SPIN_BUG_ON(lock->owner == current, lock, "recursion"); |
@@ -118,20 +115,13 @@ void _raw_spin_unlock(spinlock_t *lock) | |||
118 | 115 | ||
119 | static void rwlock_bug(rwlock_t *lock, const char *msg) | 116 | static void rwlock_bug(rwlock_t *lock, const char *msg) |
120 | { | 117 | { |
121 | static long print_once = 1; | 118 | if (!debug_locks_off()) |
122 | 119 | return; | |
123 | if (xchg(&print_once, 0)) { | 120 | |
124 | printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", | 121 | printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", |
125 | msg, raw_smp_processor_id(), current->comm, | 122 | msg, raw_smp_processor_id(), current->comm, |
126 | current->pid, lock); | 123 | current->pid, lock); |
127 | dump_stack(); | 124 | dump_stack(); |
128 | #ifdef CONFIG_SMP | ||
129 | /* | ||
130 | * We cannot continue on SMP: | ||
131 | */ | ||
132 | panic("bad locking"); | ||
133 | #endif | ||
134 | } | ||
135 | } | 125 | } |
136 | 126 | ||
137 | #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) | 127 | #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) |