From: Peter Zijlstra <a.p.zijlstra@chello.nl> Date: Tue, 18 Dec 2007 12:22:13 +0100 Subject: [lockdep] mismatched lockdep_depth/curr_chain_hash Message-id: 20071218112316.357856238@chello.nl O-Subject: [RHEL5.2 PATCH 12/14] lockdep: fix mismatched lockdep_depth/curr_chain_hash Bugzilla: 193729 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> diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 1fb2d90..984e1e3 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2274,7 +2274,6 @@ out_calc_hash: } #endif chain_key = iterate_chain_key(chain_key, id); - curr->curr_chain_key = chain_key; #ifdef CONFIG_PROVE_LOCKING /* @@ -2322,6 +2321,7 @@ out_calc_hash: } #endif + curr->curr_chain_key = chain_key; curr->lockdep_depth++; check_chain_key(curr); if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {