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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-01-04 13:30:33 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-02-21 09:03:23 -0800 |
| commit | fe15d706cfc1cb321dbe2329b04b5ca185edff60 (patch) | |
| tree | bec14ab52167f4f0210e8c207c93922c8270402f /kernel/rcutree.c | |
| parent | 18fec7d8758dd416904da205375e6fa667defc80 (diff) | |
| download | lwn-fe15d706cfc1cb321dbe2329b04b5ca185edff60.tar.gz lwn-fe15d706cfc1cb321dbe2329b04b5ca185edff60.zip | |
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 <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 6c4a6722abfd..3cf713a724c1 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); |