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authorIngo Molnar <mingo@kernel.org>2013-10-10 10:16:30 +0200
committerIngo Molnar <mingo@kernel.org>2013-10-11 07:39:14 +0200
commit3f0116c3238a96bc18ad4b4acefe4e7be32fa861 (patch)
treeb30e1fd03f2ab222051d8d1eb776bd1895416497 /arch/x86
parent2fe80d3bbf1c8bd9efc5b8154207c8dd104e7306 (diff)
compiler/gcc4: Add quirk for 'asm goto' miscompilation bug
Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Suggested-by: Jakub Jelinek <jakub@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/cpufeature.h6
-rw-r--r--arch/x86/include/asm/jump_label.h2
-rw-r--r--arch/x86/include/asm/mutex_64.h4
3 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index d3f5c63078d..89270b4318d 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -374,7 +374,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit)
* Catch too early usage of this before alternatives
* have run.
*/
- asm goto("1: jmp %l[t_warn]\n"
+ asm_volatile_goto("1: jmp %l[t_warn]\n"
"2:\n"
".section .altinstructions,\"a\"\n"
" .long 1b - .\n"
@@ -388,7 +388,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit)
#endif
- asm goto("1: jmp %l[t_no]\n"
+ asm_volatile_goto("1: jmp %l[t_no]\n"
"2:\n"
".section .altinstructions,\"a\"\n"
" .long 1b - .\n"
@@ -453,7 +453,7 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit)
* have. Thus, we force the jump to the widest, 4-byte, signed relative
* offset even though the last would often fit in less bytes.
*/
- asm goto("1: .byte 0xe9\n .long %l[t_dynamic] - 2f\n"
+ asm_volatile_goto("1: .byte 0xe9\n .long %l[t_dynamic] - 2f\n"
"2:\n"
".section .altinstructions,\"a\"\n"
" .long 1b - .\n" /* src offset */
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
index 64507f35800..6a2cefb4395 100644
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -18,7 +18,7 @@
static __always_inline bool arch_static_branch(struct static_key *key)
{
- asm goto("1:"
+ asm_volatile_goto("1:"
".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
".pushsection __jump_table, \"aw\" \n\t"
_ASM_ALIGN "\n\t"
diff --git a/arch/x86/include/asm/mutex_64.h b/arch/x86/include/asm/mutex_64.h
index e7e6751648e..07537a44216 100644
--- a/arch/x86/include/asm/mutex_64.h
+++ b/arch/x86/include/asm/mutex_64.h
@@ -20,7 +20,7 @@
static inline void __mutex_fastpath_lock(atomic_t *v,
void (*fail_fn)(atomic_t *))
{
- asm volatile goto(LOCK_PREFIX " decl %0\n"
+ asm_volatile_goto(LOCK_PREFIX " decl %0\n"
" jns %l[exit]\n"
: : "m" (v->counter)
: "memory", "cc"
@@ -75,7 +75,7 @@ static inline int __mutex_fastpath_lock_retval(atomic_t *count)
static inline void __mutex_fastpath_unlock(atomic_t *v,
void (*fail_fn)(atomic_t *))
{
- asm volatile goto(LOCK_PREFIX " incl %0\n"
+ asm_volatile_goto(LOCK_PREFIX " incl %0\n"
" jg %l[exit]\n"
: : "m" (v->counter)
: "memory", "cc"