ARM: 8475/1: SWP emulation: Restore original *data when failed

__user_swpX_asm maybe failed in first STREX operation, emulate_swpX
will try again, but the *data has been changed in first time. which
causes the result is wrong.
This patch is to fix this issue. When STREX succeed, change the *data.
if it fail, *data is not changed.

Signed-off-by: Shengjiu Wang <[email protected]>
Signed-off-by: Russell King <[email protected]>

Author: Shengjiu Wang

arch/arm/kernel/swp_emulate.c

@@ -36,10 +36,10 @@
  */
 #define __user_swpX_asm(data, addr, res, temp, B)		\
 	__asm__ __volatile__(					\
-	"	mov		%2, %1\n"			\
-	"0:	ldrex"B"	%1, [%3]\n"			\
-	"1:	strex"B"	%0, %2, [%3]\n"			\
+	"0:	ldrex"B"	%2, [%3]\n"			\
+	"1:	strex"B"	%0, %1, [%3]\n"			\
 	"	cmp		%0, #0\n"			\
+	"	moveq		%1, %2\n"			\
 	"	movne		%0, %4\n"			\
 	"2:\n"							\
 	"	.section	 .text.fixup,\"ax\"\n"		\