From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 10 Sep 2010 20:32:53 +0000 (+0200)
Subject: x86, tsc: Fix a preemption leak in restore_sched_clock_state()
X-Git-Tag: firefly_0821_release~10186^2~995
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f5f6687a47de60dc11007ee7a962cf366027d4ec;p=firefly-linux-kernel-4.4.55.git

x86, tsc: Fix a preemption leak in restore_sched_clock_state()

commit 55496c896b8a695140045099d4e0175cf09d4eae upstream.

Doh, a real life genuine preemption leak..

This caused a suspend failure.

Reported-bisected-and-tested-by-the-invaluable: Jeff Chua <jeff.chua.linux@gmail.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Nico Schottelius <nico-linux-20100709@schottelius.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Florian Pritz <flo@xssn.at>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Len Brown <lenb@kernel.org>
sleep states
LKML-Reference: <1284150773.402.122.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 3a979337a115..aaefa71888cb 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -655,7 +655,7 @@ void restore_sched_clock_state(void)
 
 	local_irq_save(flags);
 
-	get_cpu_var(cyc2ns_offset) = 0;
+	__get_cpu_var(cyc2ns_offset) = 0;
 	offset = cyc2ns_suspend - sched_clock();
 
 	for_each_possible_cpu(cpu)