diff options
Diffstat (limited to 'kernels/linux-libre-knock/0001-quirk-asm_volatile_goto.patch')
| -rw-r--r-- | kernels/linux-libre-knock/0001-quirk-asm_volatile_goto.patch | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/kernels/linux-libre-knock/0001-quirk-asm_volatile_goto.patch b/kernels/linux-libre-knock/0001-quirk-asm_volatile_goto.patch new file mode 100644 index 000000000..c9ee40400 --- /dev/null +++ b/kernels/linux-libre-knock/0001-quirk-asm_volatile_goto.patch @@ -0,0 +1,51 @@ +From a9f180345f5378ac87d80ed0bea55ba421d83859 Mon Sep 17 00:00:00 2001 +From: Steven Noonan <steven@uplinklabs.net> +Date: Thu, 13 Feb 2014 07:01:07 +0000 +Subject: 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 <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> +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=58670 +Signed-off-by: Ingo Molnar <mingo@kernel.org> +--- +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 +-- +cgit v0.9.2 |