Commit-ID: cba8244a0f1c277b6b1e48ed6504fa434119e24d Gitweb: http://git.kernel.org/tip/cba8244a0f1c277b6b1e48ed6504fa434119e24d Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> AuthorDate: Mon, 4 Jan 2010 16:04:01 -0800 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Wed, 13 Jan 2010 09:06:06 +0100 rcu: Add debug check for too many rcu_read_unlock() TREE_PREEMPT_RCU maintains an rcu_read_lock_nesting counter in the task structure, which happens to be a signed int. So this patch adds a check for this counter being negative at the end of __rcu_read_unlock(). This check is under CONFIG_PROVE_LOCKING, so can be thought of as being part of lockdep. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: laijs@xxxxxxxxxxxxxx Cc: dipankar@xxxxxxxxxx Cc: mathieu.desnoyers@xxxxxxxxxx Cc: josh@xxxxxxxxxxxxxxxx Cc: dvhltc@xxxxxxxxxx Cc: niv@xxxxxxxxxx Cc: peterz@xxxxxxxxxxxxx Cc: rostedt@xxxxxxxxxxx Cc: Valdis.Kletnieks@xxxxxx Cc: dhowells@xxxxxxxxxx LKML-Reference: <12626498423064-git-send-email-> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/rcutree_plugin.h | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index f11ebd4..e77cdf3 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -304,6 +304,9 @@ void __rcu_read_unlock(void) if (--ACCESS_ONCE(t->rcu_read_lock_nesting) == 0 && unlikely(ACCESS_ONCE(t->rcu_read_unlock_special))) rcu_read_unlock_special(t); +#ifdef CONFIG_PROVE_LOCKING + WARN_ON_ONCE(ACCESS_ONCE(t->rcu_read_lock_nesting) < 0); +#endif /* #ifdef CONFIG_PROVE_LOCKING */ } EXPORT_SYMBOL_GPL(__rcu_read_unlock); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|