alistair23-linux/arch/arm64/include/asm/jump_label.h
Miguel Ojeda 13aceef06a arm64: jump_label.h: use asm_volatile_goto macro instead of "asm goto"
All other uses of "asm goto" go through asm_volatile_goto, which avoids
a miscompile when using GCC < 4.8.2. Replace our open-coded "asm goto"
statements with the asm_volatile_goto macro to avoid issues with older
toolchains.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-09-11 11:07:11 +01:00

67 lines
1.7 KiB
C

/*
* Copyright (C) 2013 Huawei Ltd.
* Author: Jiang Liu <liuj97@gmail.com>
*
* Based on arch/arm/include/asm/jump_label.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_JUMP_LABEL_H
#define __ASM_JUMP_LABEL_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <asm/insn.h>
#define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE
static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
{
asm_volatile_goto("1: nop\n\t"
".pushsection __jump_table, \"aw\"\n\t"
".align 3\n\t"
".quad 1b, %l[l_yes], %c0\n\t"
".popsection\n\t"
: : "i"(&((char *)key)[branch]) : : l_yes);
return false;
l_yes:
return true;
}
static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
asm_volatile_goto("1: b %l[l_yes]\n\t"
".pushsection __jump_table, \"aw\"\n\t"
".align 3\n\t"
".quad 1b, %l[l_yes], %c0\n\t"
".popsection\n\t"
: : "i"(&((char *)key)[branch]) : : l_yes);
return false;
l_yes:
return true;
}
typedef u64 jump_label_t;
struct jump_entry {
jump_label_t code;
jump_label_t target;
jump_label_t key;
};
#endif /* __ASSEMBLY__ */
#endif /* __ASM_JUMP_LABEL_H */