[PATCH 3.2 080/110] s390/process: fix sfpc inline assembly

From: Ben Hutchings
Date: Mon Aug 10 2015 - 06:17:27 EST


3.2.71-rc1 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>
---
arch/s390/kernel/process.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -250,7 +250,7 @@ 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));
}

/*

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