[tip:timers/urgent] tick: Use zalloc_cpumask_var for allocating offstack cpumasks

[tip-bot for Thomas Gleixner <tipbot@zytor.com>]

Commit-ID:  642fb0f86fa38efefc0cf0e46ac20fa03e7f7f01
Gitweb:     http://git.kernel.org/tip/642fb0f86fa38efefc0cf0e46ac20fa03e7f7f01
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Fri, 3 May 2013 20:22:36 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 5 May 2013 16:06:35 +0200

tick: Use zalloc_cpumask_var for allocating offstack cpumasks

commit b352bc1cbc (tick: Convert broadcast cpu bitmaps to
cpumask_var_t) broke CONFIG_CPUMASK_OFFSTACK in a very subtle way.

Instead of allocating the cpumasks with zalloc_cpumask_var it uses
alloc_cpumask_var, so we can get random data there, which of course
confuses the logic completely and causes random failures.

Reported-and-tested-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305032015060.2990@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/time/tick-broadcast.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 61d00a8..d70cdc4 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -785,11 +785,11 @@ bool tick_broadcast_oneshot_available(void)
 
 void __init tick_broadcast_init(void)
 {
-	alloc_cpumask_var(&tick_broadcast_mask, GFP_NOWAIT);
-	alloc_cpumask_var(&tmpmask, GFP_NOWAIT);
+	zalloc_cpumask_var(&tick_broadcast_mask, GFP_NOWAIT);
+	zalloc_cpumask_var(&tmpmask, GFP_NOWAIT);
 #ifdef CONFIG_TICK_ONESHOT
-	alloc_cpumask_var(&tick_broadcast_oneshot_mask, GFP_NOWAIT);
-	alloc_cpumask_var(&tick_broadcast_pending_mask, GFP_NOWAIT);
-	alloc_cpumask_var(&tick_broadcast_force_mask, GFP_NOWAIT);
+	zalloc_cpumask_var(&tick_broadcast_oneshot_mask, GFP_NOWAIT);
+	zalloc_cpumask_var(&tick_broadcast_pending_mask, GFP_NOWAIT);
+	zalloc_cpumask_var(&tick_broadcast_force_mask, GFP_NOWAIT);
 #endif
 }