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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/srcu.c
parentrcu: Improve synchronize_rcu() diagnostics (diff)
downloadlinux-dev-fe15d706cfc1cb321dbe2329b04b5ca185edff60.tar.xz
linux-dev-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/srcu.c')
-rw-r--r--kernel/srcu.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/srcu.c b/kernel/srcu.c
index 0febf61e1aa3..3f99fa0e8ed3 100644
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -172,6 +172,12 @@ static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void))
{
int idx;
+ rcu_lockdep_assert(!lock_is_held(&sp->dep_map) &&
+ !lock_is_held(&rcu_bh_lock_map) &&
+ !lock_is_held(&rcu_lock_map) &&
+ !lock_is_held(&rcu_sched_lock_map),
+ "Illegal synchronize_srcu() in same-type SRCU (or RCU) read-side critical section");
+
idx = sp->completed;
mutex_lock(&sp->mutex);