From 2ca052a3710fac208eee690faefdeb8bbd4586a1 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 2 Apr 2012 16:15:33 -0700 Subject: [PATCH] x86: Use correct byte-sized register constraint in __xchg_op() x86-64 can access the low half of any register, but i386 can only do it with a subset of registers. 'r' causes compilation failures on i386, but 'q' expresses the constraint properly. Signed-off-by: Jeremy Fitzhardinge Link: http://lkml.kernel.org/r/4F7A3315.501@goop.org Reported-by: Leigh Scott Tested-by: Thomas Reitmayr Signed-off-by: H. Peter Anvin Cc: v3.3 --- arch/x86/include/asm/cmpxchg.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index b3b733262909..bc18d0ed459a 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -43,7 +43,7 @@ extern void __add_wrong_size(void) switch (sizeof(*(ptr))) { \ case __X86_CASE_B: \ asm volatile (lock #op "b %b0, %1\n" \ - : "+r" (__ret), "+m" (*(ptr)) \ + : "+q" (__ret), "+m" (*(ptr)) \ : : "memory", "cc"); \ break; \ case __X86_CASE_W: \ -- 2.39.5