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efbc95787c
Inspired by x86 commit 864b435514b2("x86/jump_label: Mark arguments as
const to satisfy asm constraints"), mark arch_static_branch()'s and
arch_static_branch_jump()'s arguments as const to satisfy asm
constraints. And Steven in [1] also pointed out that "The "i"
constraint needs to be a constant."
Tested with building a simple external kernel module with "O0".
[1]https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20221006075542.2658-2-jszhang@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
54 lines
1.2 KiB
C
54 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2013 Huawei Ltd.
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* Author: Jiang Liu <liuj97@gmail.com>
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*
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* Based on arch/arm/include/asm/jump_label.h
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*/
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#ifndef __ASM_JUMP_LABEL_H
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#define __ASM_JUMP_LABEL_H
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <asm/insn.h>
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#define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE
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static __always_inline bool arch_static_branch(struct static_key * const key,
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const bool branch)
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{
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asm_volatile_goto(
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"1: nop \n\t"
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" .pushsection __jump_table, \"aw\" \n\t"
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" .align 3 \n\t"
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" .long 1b - ., %l[l_yes] - . \n\t"
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" .quad %c0 - . \n\t"
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" .popsection \n\t"
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: : "i"(&((char *)key)[branch]) : : l_yes);
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return false;
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l_yes:
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return true;
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}
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static __always_inline bool arch_static_branch_jump(struct static_key * const key,
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const bool branch)
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{
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asm_volatile_goto(
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"1: b %l[l_yes] \n\t"
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" .pushsection __jump_table, \"aw\" \n\t"
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" .align 3 \n\t"
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" .long 1b - ., %l[l_yes] - . \n\t"
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" .quad %c0 - . \n\t"
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" .popsection \n\t"
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: : "i"(&((char *)key)[branch]) : : l_yes);
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return false;
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l_yes:
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return true;
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}
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#endif /* __ASSEMBLY__ */
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#endif /* __ASM_JUMP_LABEL_H */
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