[PATCH] s390: fix machine check handling

From: Sebastian Ott
Date: Fri Nov 28 2014 - 09:40:57 EST


Commit eb7e7d76 "s390: Replace __get_cpu_var uses" broke machine check
handling.

We copy machine check information from per-cpu to a stack variable for
local processing. Next we should zap the per-cpu variable, not the
stack variable.

Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
---
arch/s390/kernel/nmi.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index dd1c24c..3f51cf4 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -54,12 +54,8 @@ void s390_handle_mcck(void)
*/
local_irq_save(flags);
local_mcck_disable();
- /*
- * Ummm... Does this make sense at all? Copying the percpu struct
- * and then zapping it one statement later?
- */
- memcpy(&mcck, this_cpu_ptr(&cpu_mcck), sizeof(mcck));
- memset(&mcck, 0, sizeof(struct mcck_struct));
+ mcck = *this_cpu_ptr(&cpu_mcck);
+ memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck));
clear_cpu_flag(CIF_MCCK_PENDING);
local_mcck_enable();
local_irq_restore(flags);
--
1.8.4.2

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