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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 12:49:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 12:49:31 -0700
commit31b7eab27a314b153d8fa07ba9e9ec00a98141e1 (patch)
tree47415377d5f9bcf8c06e501f1636088548202edf /kernel
parent1053e6bba091d9d18797f7789df6a7ef8735f20c (diff)
parent4ba053c04aece1f4734056f21b751eee47ea3fb1 (diff)
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: Check the depth of subclass lockdep: Add improved subclass caching affs: Use sema_init instead of init_MUTEX hfs: Convert tree_lock to mutex arm: Bcmring: semaphore cleanup printk: Make console_sem a semaphore not a pseudo mutex drivers/macintosh/adb: Do not claim that the semaphore is a mutex parport: Semaphore cleanup irda: Semaphore cleanup net: Wan/cosa.c: Convert "mutex" to semaphore net: Ppp_async: semaphore cleanup hamradio: Mkiss: semaphore cleanup hamradio: 6pack: semaphore cleanup net: 3c527: semaphore cleanup input: Serio/hp_sdc: semaphore cleanup input: Serio/hil_mlc: semaphore cleanup input: Misc/hp_sdc_rtc: semaphore cleanup lockup_detector: Make callback function static lockup detector: Fix grammar by adding a missing "to" in the comments lockdep: Remove __debug_show_held_locks
Diffstat (limited to 'kernel')
-rw-r--r--kernel/hung_task.c4
-rw-r--r--kernel/lockdep.c51
-rw-r--r--kernel/printk.c4
-rw-r--r--kernel/watchdog.c2
4 files changed, 34 insertions, 27 deletions
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 0c642d51aac2..53ead174da2f 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -98,7 +98,7 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
" disables this message.\n");
sched_show_task(t);
- __debug_show_held_locks(t);
+ debug_show_held_locks(t);
touch_nmi_watchdog();
@@ -111,7 +111,7 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
* periodically exit the critical section and enter a new one.
*
* For preemptible RCU it is sufficient to call rcu_read_unlock in order
- * exit the grace period. For classic RCU, a reschedule is required.
+ * to exit the grace period. For classic RCU, a reschedule is required.
*/
static void rcu_lock_break(struct task_struct *g, struct task_struct *t)
{
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f2852a510232..42ba65dff7d9 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -639,6 +639,16 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
}
#endif
+ if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+ debug_locks_off();
+ printk(KERN_ERR
+ "BUG: looking up invalid subclass: %u\n", subclass);
+ printk(KERN_ERR
+ "turning off the locking correctness validator.\n");
+ dump_stack();
+ return NULL;
+ }
+
/*
* Static locks do not have their class-keys yet - for them the key
* is the lock object itself:
@@ -774,7 +784,9 @@ out_unlock_set:
raw_local_irq_restore(flags);
if (!subclass || force)
- lock->class_cache = class;
+ lock->class_cache[0] = class;
+ else if (subclass < NR_LOCKDEP_CACHING_CLASSES)
+ lock->class_cache[subclass] = class;
if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass))
return NULL;
@@ -2679,7 +2691,11 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass)
{
- lock->class_cache = NULL;
+ int i;
+
+ for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
+ lock->class_cache[i] = NULL;
+
#ifdef CONFIG_LOCK_STAT
lock->cpu = raw_smp_processor_id();
#endif
@@ -2739,21 +2755,13 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
- if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
- debug_locks_off();
- printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
- printk("turning off the locking correctness validator.\n");
- dump_stack();
- return 0;
- }
-
if (lock->key == &__lockdep_no_validate__)
check = 1;
- if (!subclass)
- class = lock->class_cache;
+ if (subclass < NR_LOCKDEP_CACHING_CLASSES)
+ class = lock->class_cache[subclass];
/*
- * Not cached yet or subclass?
+ * Not cached?
*/
if (unlikely(!class)) {
class = register_lock_class(lock, subclass, 0);
@@ -2918,7 +2926,7 @@ static int match_held_lock(struct held_lock *hlock, struct lockdep_map *lock)
return 1;
if (hlock->references) {
- struct lock_class *class = lock->class_cache;
+ struct lock_class *class = lock->class_cache[0];
if (!class)
class = look_up_lock_class(lock, 0);
@@ -3559,7 +3567,12 @@ void lockdep_reset_lock(struct lockdep_map *lock)
if (list_empty(head))
continue;
list_for_each_entry_safe(class, next, head, hash_entry) {
- if (unlikely(class == lock->class_cache)) {
+ int match = 0;
+
+ for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
+ match |= class == lock->class_cache[j];
+
+ if (unlikely(match)) {
if (debug_locks_off_graph_unlock())
WARN_ON(1);
goto out_restore;
@@ -3775,7 +3788,7 @@ EXPORT_SYMBOL_GPL(debug_show_all_locks);
* Careful: only use this function if you are sure that
* the task cannot run in parallel!
*/
-void __debug_show_held_locks(struct task_struct *task)
+void debug_show_held_locks(struct task_struct *task)
{
if (unlikely(!debug_locks)) {
printk("INFO: lockdep is turned off.\n");
@@ -3783,12 +3796,6 @@ void __debug_show_held_locks(struct task_struct *task)
}
lockdep_print_held_locks(task);
}
-EXPORT_SYMBOL_GPL(__debug_show_held_locks);
-
-void debug_show_held_locks(struct task_struct *task)
-{
- __debug_show_held_locks(task);
-}
EXPORT_SYMBOL_GPL(debug_show_held_locks);
void lockdep_sys_exit(void)
diff --git a/kernel/printk.c b/kernel/printk.c
index 8fe465ac008a..2531017795f6 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -85,7 +85,7 @@ EXPORT_SYMBOL(oops_in_progress);
* provides serialisation for access to the entire console
* driver system.
*/
-static DECLARE_MUTEX(console_sem);
+static DEFINE_SEMAPHORE(console_sem);
struct console *console_drivers;
EXPORT_SYMBOL_GPL(console_drivers);
@@ -556,7 +556,7 @@ static void zap_locks(void)
/* If a crash is occurring, make sure we can't deadlock */
spin_lock_init(&logbuf_lock);
/* And make sure that we print immediately */
- init_MUTEX(&console_sem);
+ sema_init(&console_sem, 1);
}
#if defined(CONFIG_PRINTK_TIME)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 7f9c3c52ecc1..2feb2870d3a1 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -209,7 +209,7 @@ static struct perf_event_attr wd_hw_attr = {
};
/* Callback function for perf event subsystem */
-void watchdog_overflow_callback(struct perf_event *event, int nmi,
+static void watchdog_overflow_callback(struct perf_event *event, int nmi,
struct perf_sample_data *data,
struct pt_regs *regs)
{