3f0116c323
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>
50 lines
971 B
C
50 lines
971 B
C
/*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* Copyright (c) 2010 Cavium Networks, Inc.
|
|
*/
|
|
#ifndef _ASM_MIPS_JUMP_LABEL_H
|
|
#define _ASM_MIPS_JUMP_LABEL_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#define JUMP_LABEL_NOP_SIZE 4
|
|
|
|
#ifdef CONFIG_64BIT
|
|
#define WORD_INSN ".dword"
|
|
#else
|
|
#define WORD_INSN ".word"
|
|
#endif
|
|
|
|
static __always_inline bool arch_static_branch(struct static_key *key)
|
|
{
|
|
asm_volatile_goto("1:\tnop\n\t"
|
|
"nop\n\t"
|
|
".pushsection __jump_table, \"aw\"\n\t"
|
|
WORD_INSN " 1b, %l[l_yes], %0\n\t"
|
|
".popsection\n\t"
|
|
: : "i" (key) : : l_yes);
|
|
return false;
|
|
l_yes:
|
|
return true;
|
|
}
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#ifdef CONFIG_64BIT
|
|
typedef u64 jump_label_t;
|
|
#else
|
|
typedef u32 jump_label_t;
|
|
#endif
|
|
|
|
struct jump_entry {
|
|
jump_label_t code;
|
|
jump_label_t target;
|
|
jump_label_t key;
|
|
};
|
|
|
|
#endif /* _ASM_MIPS_JUMP_LABEL_H */
|