[PATCH 3.4 021/107] s390/process: fix sfpc inline assembly

lizf
2016-03-16T08:08:29Z

From: Heiko Carstens <heiko.carstens@de.ibm.com>

3.4.111-rc1 review patch. If anyone has any objections, please let me know.

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

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@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
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 60055ce..5f947e5 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -246,7 +246,7 @@ 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));
}

/*
--
1.9.1