Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756908AbaBUAvZ (ORCPT ); Thu, 20 Feb 2014 19:51:25 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45524 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755152AbaBTXv3 (ORCPT ); Thu, 20 Feb 2014 18:51:29 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Steven Noonan , Peter Zijlstra , Steven Rostedt , Jakub Jelinek , Richard Henderson , Andrew Morton , Oleg Nesterov , Ingo Molnar Subject: [PATCH 3.10 53/66] compiler/gcc4: Make quirk for asm_volatile_goto() unconditional Date: Thu, 20 Feb 2014 15:51:52 -0800 Message-Id: <20140220234911.002709648@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140220234909.482516304@linuxfoundation.org> References: <20140220234909.482516304@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Noonan commit a9f180345f5378ac87d80ed0bea55ba421d83859 upstream. 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. So make the quirk unconditional for now, until bug is found and fixed. Suggested-by: Linus Torvalds Signed-off-by: Steven Noonan Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Jakub Jelinek Cc: Richard Henderson Cc: Andrew Morton Cc: Oleg Nesterov Link: http://lkml.kernel.org/r/1392274867-15236-1-git-send-email-steven@uplinklabs.net Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- include/linux/compiler-gcc4.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) --- 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 -- 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/