s390/process: fix sfpc inline assembly

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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit b411a8a3b44d76e782ba4bc6893068f3f590fe8a)

Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index cea285546e6578e0e6e2e662993e6f4d2df526eb..0d3448d247a9b8d8bc73b545f269d947f9e9bcae 100644 (file)
--- 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));
 }
 
 /*