[PATCH 2.6.32 55/62] s390/process: fix sfpc inline assembly

From: Willy Tarreau
Date: Sat Sep 12 2015 - 19:26:33 EST


2.6.32-longterm review patch. If anyone has any objections, please let me know.

------------------

From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

commit e47994dd44bcb4a77b4152bd0eada585934703c0 upstream.

The sfpc inline assembly within execve_tail() may incorrectly set bits
28-31 of the sfpc instruction to a value which is not zero.
These bits however are currently unused and therefore should be zero
so we won't get surprised if these bits will be used in the future.

Therefore remove the second operand from the inline assembly.

Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
(cherry picked from commit b411a8a3b44d76e782ba4bc6893068f3f590fe8a)

Signed-off-by: Willy Tarreau <w@xxxxxx>
---
arch/s390/kernel/process.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index cea2855..0d3448d 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -261,7 +261,7 @@ asmlinkage void execve_tail(void)
{
current->thread.fp_regs.fpc = 0;
if (MACHINE_HAS_IEEE)
- asm volatile("sfpc %0,%0" : : "d" (0));
+ asm volatile("sfpc %0" : : "d" (0));
}

/*
--
1.7.12.2.21.g234cd45.dirty



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/