From 3eaaaf6cd6d7fbaf552cc543ccb93d7da81f43ec Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Date: Mon, 9 Mar 2015 16:51:17 -0700
Subject: [PATCH] rcu: Shut up spurious gcc uninitialized-variable warning
Because gcc doesn't realize that rcu_num_lvls must be strictly greater
than zero, some versions give a spurious warning about levelcnt[0] being
uninitialized in rcu_init_one(). This commit updates the condition on
the pre-existing panic() in order to educate gcc on this point.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index c34422d92aa93..9b076b2846954 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3982,9 +3982,9 @@ static void __init rcu_init_one(struct rcu_state *rsp,
BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */
- /* Silence gcc 4.8 warning about array index out of range. */
- if (rcu_num_lvls > RCU_NUM_LVLS)
- panic("rcu_init_one: rcu_num_lvls overflow");
+ /* Silence gcc 4.8 false positive about array index out of range. */
+ if (rcu_num_lvls <= 0 || rcu_num_lvls > RCU_NUM_LVLS)
+ panic("rcu_init_one: rcu_num_lvls out of range");
/* Initialize the level-tracking arrays. */
--
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