[PATCH 3.13.y-ckt 40/53] s390/process: fix sfpc inline assembly

Kamal Mostafa kamal at canonical.com
Thu Aug 6 20:38:05 UTC 2015


3.13.11-ckt25 -stable review patch.  If anyone has any objections, please let me know.

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

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

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 at de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.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 7ed0d4e..f9c21cf 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -195,7 +195,7 @@ 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





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