Messages in this thread Patch in this message | | | Date | Wed, 14 Nov 2007 22:09:17 -0800 | From | Greg KH <> | Subject | [patch 01/13] lockdep: fix mismatched lockdep_depth/curr_chain_hash |
| |
-stable review patch. If anyone has any objections, please let us know.
------------------
From: Gregory Haskins <ghaskins@novell.com>
patch 3aa416b07f0adf01c090baab26fb70c35ec17623 in mainline.
It is possible for the current->curr_chain_key to become inconsistent with the current index if the chain fails to validate. The end result is that future lock_acquire() operations may inadvertently fail to find a hit in the cache resulting in a new node being added to the graph for every acquire.
Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- kernel/lockdep.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
--- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -1521,7 +1521,7 @@ cache_hit: } static int validate_chain(struct task_struct *curr, struct lockdep_map *lock, - struct held_lock *hlock, int chain_head) + struct held_lock *hlock, int chain_head, u64 chain_key) { /* * Trylock needs to maintain the stack of held locks, but it @@ -1534,7 +1534,7 @@ static int validate_chain(struct task_st * graph_lock for us) */ if (!hlock->trylock && (hlock->check == 2) && - lookup_chain_cache(curr->curr_chain_key, hlock->class)) { + lookup_chain_cache(chain_key, hlock->class)) { /* * Check whether last held lock: * @@ -1576,7 +1576,7 @@ static int validate_chain(struct task_st #else static inline int validate_chain(struct task_struct *curr, struct lockdep_map *lock, struct held_lock *hlock, - int chain_head) + int chain_head, u64 chain_key) { return 1; } @@ -2450,11 +2450,11 @@ static int __lock_acquire(struct lockdep chain_head = 1; } chain_key = iterate_chain_key(chain_key, id); - curr->curr_chain_key = chain_key; - if (!validate_chain(curr, lock, hlock, chain_head)) + if (!validate_chain(curr, lock, hlock, chain_head, chain_key)) return 0; + curr->curr_chain_key = chain_key; curr->lockdep_depth++; check_chain_key(curr); #ifdef CONFIG_DEBUG_LOCKDEP -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |