Messages in this thread |  | | Subject | Re: [PATCH] compiler/gcc4: make quirk for asm_volatile_goto unconditional | From | Mike Galbraith <> | Date | Thu, 13 Feb 2014 07:48:26 +0100 |
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On Wed, 2014-02-12 at 20:53 -0800, Steven Noonan wrote: > 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 <mingo@elte.hu> > Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org v3.12+ ?
> Signed-off-by: Steven Noonan <steven@uplinklabs.net> > --- > 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
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