From: Shengjiu Wang Date: Tue, 8 Dec 2015 12:37:19 +0000 (+0100) Subject: ARM: 8475/1: SWP emulation: Restore original *data when failed X-Git-Tag: firefly_0821_release~176^2~557^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=34bfbae33ae84107d0c257edd6c6a8689a09be26;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Russell King --- diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c index 5b26e7efa9ea..c3fe769d7558 100644 --- a/arch/arm/kernel/swp_emulate.c +++ b/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" \