Commit-ID: a9f180345f5378ac87d80ed0bea55ba421d83859 Gitweb: http://git.kernel.org/tip/a9f180345f5378ac87d80ed0bea55ba421d83859 Author: Steven Noonan <ste...@uplinklabs.net> AuthorDate: Wed, 12 Feb 2014 23:01:07 -0800 Committer: Ingo Molnar <mi...@kernel.org> 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 <torva...@linux-foundation.org> Signed-off-by: Steven Noonan <ste...@uplinklabs.net> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Jakub Jelinek <ja...@redhat.com> Cc: Richard Henderson <r...@twiddle.net> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Oleg Nesterov <o...@redhat.com> Cc: <sta...@vger.kernel.org> Link: http://lkml.kernel.org/r/1392274867-15236-1-git-send-email-ste...@uplinklabs.net Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
