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authorJarek Poplawski <jarkao2@o2.pl>2006-12-07 10:45:25 +0100
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 08:39:33 -0800
commit910b1b2e6d7d10e1c3bffdd12a90ec82f535f9a5 (patch)
tree89526504d80a20f54ab561a50b3d846fdc508fa3 /kernel/lockdep.c
parentb4178ab58aa81f4ed3c75c48940682fe3b45d880 (diff)
downloadlwn-910b1b2e6d7d10e1c3bffdd12a90ec82f535f9a5.tar.gz
lwn-910b1b2e6d7d10e1c3bffdd12a90ec82f535f9a5.zip
[PATCH] lockdep: internal locking fixes
Here are mainly some lockdep returns with 0 with unlocking fixes. Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/lockdep.c')
-rw-r--r--kernel/lockdep.c25
1 files changed, 15 insertions, 10 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index e33f6207f5b3..f76a24f2ac20 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -237,8 +237,10 @@ e locks. */
trace->max_entries = trace->nr_entries;
nr_stack_trace_entries += trace->nr_entries;
- if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES))
+ if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES)) {
+ __raw_spin_unlock(&hash_lock);
return 0;
+ }
if (nr_stack_trace_entries == MAX_STACK_TRACE_ENTRIES) {
__raw_spin_unlock(&hash_lock);
@@ -474,7 +476,8 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
return 0;
entry->class = this;
- save_trace(&entry->trace);
+ if (!save_trace(&entry->trace))
+ return 0;
/*
* Since we never remove from the dependency list, the list can
@@ -562,8 +565,12 @@ static noinline int print_circular_bug_tail(void)
if (debug_locks_silent)
return 0;
+ /* hash_lock unlocked by the header */
+ __raw_spin_lock(&hash_lock);
this.class = check_source->class;
- save_trace(&this.trace);
+ if (!save_trace(&this.trace))
+ return 0;
+ __raw_spin_unlock(&hash_lock);
print_circular_bug_entry(&this, 0);
printk("\nother info that might help us debug this:\n\n");
@@ -966,14 +973,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
&prev->class->locks_after, next->acquire_ip);
if (!ret)
return 0;
- /*
- * Return value of 2 signals 'dependency already added',
- * in that case we dont have to add the backlink either.
- */
- if (ret == 2)
- return 2;
+
ret = add_lock_to_list(next->class, prev->class,
&next->class->locks_before, next->acquire_ip);
+ if (!ret)
+ return 0;
/*
* Debugging printouts:
@@ -1025,7 +1029,8 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
* added:
*/
if (hlock->read != 2) {
- check_prev_add(curr, hlock, next);
+ if (!check_prev_add(curr, hlock, next))
+ return 0;
/*
* Stop after the first non-trylock entry,
* as non-trylock entries have added their