From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755353AbbGQWbl (ORCPT ); Fri, 17 Jul 2015 18:31:41 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:56857 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755064AbbGQWbZ (ORCPT ); Fri, 17 Jul 2015 18:31:25 -0400 X-Helo: d03dlp02.boulder.ibm.com X-MailFrom: paulmck@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 12/12] rcu: Reset rcu_fanout_leaf if out of bounds Date: Fri, 17 Jul 2015 15:31:03 -0700 Message-Id: <1437172263-15466-12-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1437172263-15466-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150717223041.GA14464@linux.vnet.ibm.com> <1437172263-15466-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15071722-0025-0000-0000-0000173C054D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" Currently if the rcu_fanout_leaf boot parameter is out of bounds (that is, less than RCU_FANOUT_LEAF or greater than the number of bits in an unsigned long), a warning is issued and execution continues with the out-of-bounds value. This can result in all manner of failures, so this patch resets rcu_fanout_leaf to RCU_FANOUT_LEAF when an out-of-bounds condition is detected. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e53bbc53bcd5..a2147d7b51c0 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4103,6 +4103,7 @@ static void __init rcu_init_geometry(void) */ if (rcu_fanout_leaf < RCU_FANOUT_LEAF || rcu_fanout_leaf > sizeof(unsigned long) * 8) { + rcu_fanout_leaf = RCU_FANOUT_LEAF; WARN_ON(1); return; } -- 1.8.1.5