Commit a9f18034 authored by Steven Noonan's avatar Steven Noonan Committed by Ingo Molnar

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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSteven Noonan <steven@uplinklabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
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=58670Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 569d6557
...@@ -75,11 +75,7 @@ ...@@ -75,11 +75,7 @@
* *
* (asm goto is automatically volatile - the naming reflects this.) * (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)
# 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
#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
#if GCC_VERSION >= 40400 #if GCC_VERSION >= 40400
......
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