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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-01-04 22:30:33 +0100
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-02-21 18:03:23 +0100
commitfe15d706cfc1cb321dbe2329b04b5ca185edff60 (patch)
treebec14ab52167f4f0210e8c207c93922c8270402f /kernel/rcutree_plugin.h
parentrcu: Improve synchronize_rcu() diagnostics (diff)
downloadlinux-fe15d706cfc1cb321dbe2329b04b5ca185edff60.tar.xz
linux-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_plugin.h')
-rw-r--r--kernel/rcutree_plugin.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 8bb35d73e1f9..3680b6b35bf3 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -688,6 +688,10 @@ EXPORT_SYMBOL_GPL(call_rcu);
*/
void synchronize_rcu(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() in RCU read-side critical section");
if (!rcu_scheduler_active)
return;
wait_rcu_gp(call_rcu);