[PATCH v2 03/14] notifiers: Assert that RCU is watching in notify_die

From: Andy Lutomirski
Date: Thu Jun 18 2015 - 15:12:11 EST

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@xxxxxxxxxx>
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);

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