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From: Andy Lutomirski <luto@kernel.org>
To: mingo@kernel.org
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Borislav Petkov" <bp@alien8.de>,
	"Frédéric Weisbecker" <fweisbec@gmail.com>,
	"Paul McKenney" <paulmck@linux.vnet.ibm.com>,
	"Andy Lutomirski" <luto@kernel.org>
Subject: [PATCH] notifiers: Assert that RCU is watching in notify_die
Date: Thu,  4 Jun 2015 17:17:06 -0700	[thread overview]
Message-ID: <8a544ca7ba99a9a64ef83df065a75eaefcf2851f.1433463380.git.luto@kernel.org> (raw)

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);
-- 
2.4.2


                 reply	other threads:[~2015-06-05  0:17 UTC|newest]

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