From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Thu, 4 Jun 2015 17:06:01 +0000 (-0700)
Subject: rcu: Reset rcu_fanout_leaf if out of bounds
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=13bd64947f53ba8d7199922be94b6626b8e222d7;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

rcu: Reset rcu_fanout_leaf if out of bounds

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 <paulmck@linux.vnet.ibm.com>
---

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;
 	}