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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-01-04 13:30:33 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-02-21 09:03:23 -0800
commitfe15d706cfc1cb321dbe2329b04b5ca185edff60 (patch)
treebec14ab52167f4f0210e8c207c93922c8270402f /kernel/rcutree.c
parent18fec7d8758dd416904da205375e6fa667defc80 (diff)
downloadop-kernel-dev-fe15d706cfc1cb321dbe2329b04b5ca185edff60.zip
op-kernel-dev-fe15d706cfc1cb321dbe2329b04b5ca185edff60.tar.gz
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.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 6c4a672..3cf713a 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);
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