[PATCH v5 05/17] notifiers: Assert that RCU is watching in notify_die

Andy Lutomirski
2015-07-03T19:49:12Z

Low-level arch entries often call notify_die, and it's easy for arch
code to fail to exit an RCU quiescent state first. Assert that
we're not quiescent in notify_die.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
kernel/notifier.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/notifier.c b/kernel/notifier.c
index ae9fc7cc360e..980e4330fb59 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -544,6 +544,8 @@ int notrace notify_die(enum die_val val, const char *str,
.signr = sig,

};
+ rcu_lockdep_assert(rcu_is_watching(),
+ "notify_die called but RCU thinks we're quiescent");
return atomic_notifier_call_chain(&die_chain, val, &args);
}
NOKPROBE_SYMBOL(notify_die);
--
2.4.3