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

From: tip-bot for Thomas Gleixner
Date: Sun May 05 2013 - 02:22:00 EST


Commit-ID: de9de4f5f11d8c89ad3e4fad49e2ebb36630a09a
Gitweb: http://git.kernel.org/tip/de9de4f5f11d8c89ad3e4fad49e2ebb36630a09a
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Fri, 3 May 2013 20:22:36 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sun, 5 May 2013 08:15:11 +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@xxxxxxxxxx>
Reported-and-tested-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Link: alpine.LFD.2.02.1305032015060.2990@ionos">http://lkml.kernel.org/r/alpine.LFD.2.02.1305032015060.2990@ionos
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
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
}
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