Commit 34bfbae3 authored Dec 08, 2015 by Shengjiu Wang Committed by Russell King Dec 15, 2015

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 <shengjiu.wang@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent fa0708b3

arch/arm/kernel/swp_emulate.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -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" \