From 6041b57c6c99dcb59524f1bb0db0628c2689a464 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 10 May 2007 22:22:14 -0700 Subject: i386: work around miscompilation of alternatives code A recent change makes my Dell 1501 hang on boot. It's an AMD MK-36. I use an x86_64 kernel. It is 100% reproducible. I debugged this problem a bit and my compiler[1]interprets the =A constraint as %rax instead of %edx:%eax on x86_64 which causes the problem. The appended patch provides a workaround for this and fixed the hang on my machine. [1] gcc version 4.1.3 20070429 (prerelease) (Debian 4.1.2-5) Signed-off-by: Joerg Roedel Cc: Andi Kleen Cc: Benny Halevy Cc: Pete Zaitcev Cc: "Joerg Roedel" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-x86_64/alternative.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/asm-x86_64') diff --git a/include/asm-x86_64/alternative.h b/include/asm-x86_64/alternative.h index a09fe85..a094276 100644 --- a/include/asm-x86_64/alternative.h +++ b/include/asm-x86_64/alternative.h @@ -103,6 +103,12 @@ static inline void alternatives_smp_switch(int smp) {} ".previous" : output : [feat] "i" (feature), ##input) /* + * use this macro(s) if you need more than one output parameter + * in alternative_io + */ +#define ASM_OUTPUT2(a, b) a, b + +/* * Alternative inline assembly for SMP. * * The LOCK_PREFIX macro defined here replaces the LOCK and -- cgit v1.1