diff options
| author | Steven Noonan <steven@uplinklabs.net> | 2014-02-12 23:01:07 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-04-02 00:58:51 +0100 |
| commit | feb4b89167c7db378c49ddd3062dbe2f9497a518 (patch) | |
| tree | c2c43108bb03b0b17665f7cc6ff4c495a8d83321 /include | |
| parent | 778c4783df0ff6dcc120fe5c1dc9b6afa1980cd0 (diff) | |
compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
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 <torvalds@linux-foundation.org>
Signed-off-by: Steven 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>
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 <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/compiler-gcc4.h | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 643d6c4a5993..e2a360ad6108 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -39,11 +39,7 @@ * * (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) #if __GNUC_MINOR__ >= 5 /* |