Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752707AbaBMHB1 (ORCPT ); Thu, 13 Feb 2014 02:01:27 -0500 Received: from mail-ie0-f174.google.com ([209.85.223.174]:59743 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141AbaBMHBZ (ORCPT ); Thu, 13 Feb 2014 02:01:25 -0500 From: Steven Noonan To: Linux Kernel Mailing List Cc: Steven Noonan , Ingo Molnar , Linus Torvalds , stable@vger.kernel.org Subject: [PATCH v2] compiler/gcc4: make quirk for asm_volatile_goto unconditional Date: Wed, 12 Feb 2014 23:01:07 -0800 Message-Id: <1392274867-15236-1-git-send-email-steven@uplinklabs.net> X-Mailer: git-send-email 1.8.5.4 In-Reply-To: <1392274106.28471.2.camel@marge.simpson.net> References: <1392274106.28471.2.camel@marge.simpson.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I started noticing problems with KVM guest destruction on Linux 3.12+, where guest memory wasn't being cleaned up. I bisected it down to the commit introducing the new 'asm goto'-based atomics, and found this quirk was later applied to those. Unfortunately, even with GCC 4.8.2 (which ostensibly fixed the known 'asm goto' bug) I am still getting some kind of miscompilation. If I enable the asm_volatile_goto quirk for my compiler, KVM guests are destroyed correctly and the memory is cleaned up. [1] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Cc: Ingo Molnar Cc: Linus Torvalds Cc: stable@vger.kernel.org Signed-off-by: Steven Noonan --- v2: Adding stable@vger.kernel.org to Cc. include/linux/compiler-gcc4.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index ded4299..2507fd2 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -75,11 +75,7 @@ * * (asm goto is automatically volatile - the naming reflects this.) */ -#if GCC_VERSION <= 40801 -# define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) -#else -# define asm_volatile_goto(x...) do { asm goto(x); } while (0) -#endif +#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP #if GCC_VERSION >= 40400 -- 1.8.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/