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/rcutree.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel/rcutree.c') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 6c4a6722abf..3cf713a724c 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1816,6 +1816,10 @@ EXPORT_SYMBOL_GPL(call_rcu_bh); */ 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-sched read-side critical section"); if (rcu_blocking_is_gp()) return; wait_rcu_gp(call_rcu_sched); @@ -1833,6 +1837,10 @@ EXPORT_SYMBOL_GPL(synchronize_sched); */ void synchronize_rcu_bh(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_rcu_bh() in RCU-bh read-side critical section"); if (rcu_blocking_is_gp()) return; wait_rcu_gp(call_rcu_bh); -- cgit v1.2.3-18-g5258