From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754639AbbFPURo (ORCPT ); Tue, 16 Jun 2015 16:17:44 -0400 Received: from mail.kernel.org ([198.145.29.136]:42499 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754885AbbFPURJ (ORCPT ); Tue, 16 Jun 2015 16:17:09 -0400 From: Andy Lutomirski To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= , Rik van Riel , Oleg Nesterov , Denys Vlasenko , Borislav Petkov , Kees Cook , Brian Gerst , Andy Lutomirski Subject: [RFC/INCOMPLETE 02/13] notifiers: Assert that RCU is watching in notify_die Date: Tue, 16 Jun 2015 13:16:48 -0700 Message-Id: <1bbe1d0fdd64f1c4c3d138692441e6bdb1c99570.1434485184.git.luto@kernel.org> X-Mailer: git-send-email 2.4.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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