From: Paul E. McKenney <paul.mckenney@linaro.org>
Date: Mon, 15 Oct 2012 15:24:54 +0000 (-0700)
Subject: rcu: Fix precedence error in cpu_needs_another_gp()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=340f588bbaed6cb518aa65e7a330dcc3fff911f8;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

rcu: Fix precedence error in cpu_needs_another_gp()

The fix introduced by a10d206e (rcu: Fix day-one dyntick-idle
stall-warning bug) has a C-language precedence error.  It turns out
that this error is harmless in that the same result is computed for all
inputs, but the code is nevertheless a potential source of confusion.
This commit therefore introduces parentheses in order to force the
execution of the code to reflect the intent.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f9c17c39953..effd47a54b3 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -313,7 +313,7 @@ static int
 cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
 {
 	return *rdp->nxttail[RCU_DONE_TAIL +
-			     ACCESS_ONCE(rsp->completed) != rdp->completed] &&
+			     (ACCESS_ONCE(rsp->completed) != rdp->completed)] &&
 	       !rcu_gp_in_progress(rsp);
 }