From fe15d706cfc1cb321dbe2329b04b5ca185edff60 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 4 Jan 2012 13:30:33 -0800 Subject: rcu: Add lockdep-RCU checks for simple self-deadlock It is illegal to have a grace period within a same-flavor RCU read-side critical section, so this commit adds lockdep-RCU checks to splat when such abuse is encountered. This commit does not detect more elaborate RCU deadlock situations. These situations might be a job for lockdep enhancements. Signed-off-by: Paul E. McKenney --- kernel/rcutiny.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel/rcutiny.c') diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index 977296dca0a4..8e00d461911e 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -319,6 +319,10 @@ static void rcu_process_callbacks(struct softirq_action *unused) */ void synchronize_sched(void) { + rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && + !lock_is_held(&rcu_lock_map) && + !lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_sched() in RCU read-side critical section"); cond_resched(); } EXPORT_SYMBOL_GPL(synchronize_sched); -- cgit v1.2.3