diff options
| author | Ingo Molnar <mingo@kernel.org> | 2013-10-10 10:16:30 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-11 07:39:14 +0200 |
| commit | 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 (patch) | |
| tree | b30e1fd03f2ab222051d8d1eb776bd1895416497 /arch/x86 | |
| parent | 2fe80d3bbf1c8bd9efc5b8154207c8dd104e7306 (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.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/jump_label.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/mutex_64.h | 4 |
3 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index d3f5c63078d8..89270b4318db 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 64507f35800c..6a2cefb4395a 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 e7e6751648ed..07537a44216e 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" |