From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 13 Feb 2014 03:37:08 -0800 From: tip-bot for Steven Noonan Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, stable@vger.kernel.org, steven@uplinklabs.net, akpm@linux-foundation.org, rostedt@goodmis.org, jakub@redhat.com, oleg@redhat.com, tglx@linutronix.de, rth@twiddle.net Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, stable@vger.kernel.org, steven@uplinklabs.net, jakub@redhat.com, rostedt@goodmis.org, akpm@linux-foundation.org, tglx@linutronix.de, oleg@redhat.com, rth@twiddle.net In-Reply-To: <1392274867-15236-1-git-send-email-steven@uplinklabs.net> References: <1392274867-15236-1-git-send-email-steven@uplinklabs.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] compiler/gcc4: Make quirk for asm_volatile_goto( ) unconditional MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: Commit-ID: a9f180345f5378ac87d80ed0bea55ba421d83859 Gitweb: http://git.kernel.org/tip/a9f180345f5378ac87d80ed0bea55ba421d83859 Author: Steven Noonan AuthorDate: Wed, 12 Feb 2014 23:01:07 -0800 Committer: Ingo Molnar CommitDate: Thu, 13 Feb 2014 12:34:05 +0100 compiler/gcc4: Make quirk for asm_volatile_goto() unconditional 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 Cc: 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 --- 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