[mirror_ubuntu-zesty-kernel.git] / arch / arm64 / kernel / jump_label.c

/*
 * Copyright (C) 2013 Huawei Ltd.
 * Author: Jiang Liu <liuj97@gmail.com>
 *
 * Based on arch/arm/kernel/jump_label.c
 *
 * 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/>.
 */
#include <linux/kernel.h>
#include <linux/jump_label.h>
#include <asm/insn.h>

#ifdef HAVE_JUMP_LABEL

void arch_jump_label_transform(struct jump_entry *entry,
			       enum jump_label_type type)
{
	void *addr = (void *)entry->code;
	u32 insn;

	if (type == JUMP_LABEL_JMP) {
		insn = aarch64_insn_gen_branch_imm(entry->code,
						   entry->target,
						   AARCH64_INSN_BRANCH_NOLINK);
	} else {
		insn = aarch64_insn_gen_nop();
	}

	aarch64_insn_patch_text(&addr, &insn, 1);
}

void arch_jump_label_transform_static(struct jump_entry *entry,
				      enum jump_label_type type)
{
	/*
	 * We use the architected A64 NOP in arch_static_branch, so there's no
	 * need to patch an identical A64 NOP over the top of it here. The core
	 * will call arch_jump_label_transform from a module notifier if the
	 * NOP needs to be replaced by a branch.
	 */
}

#endif	/* HAVE_JUMP_LABEL */
Commit	Line	Data
9732cafd JL	1	/*
	2	* Copyright (C) 2013 Huawei Ltd.
	3	* Author: Jiang Liu <liuj97@gmail.com>
	4	*
	5	* Based on arch/arm/kernel/jump_label.c
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19	#include <linux/kernel.h>
	20	#include <linux/jump_label.h>
	21	#include <asm/insn.h>
	22
	23	#ifdef HAVE_JUMP_LABEL
	24
6ddae418 MR	25	void arch_jump_label_transform(struct jump_entry *entry,
6ddae418 MR	26	enum jump_label_type type)
9732cafd JL	27	{
	28	void addr = (void )entry->code;
	29	u32 insn;
	30
76b235c6	31	if (type == JUMP_LABEL_JMP) {
9732cafd JL	32	insn = aarch64_insn_gen_branch_imm(entry->code,
	33	entry->target,
	34	AARCH64_INSN_BRANCH_NOLINK);
	35	} else {
	36	insn = aarch64_insn_gen_nop();
	37	}
	38
6ddae418	39	aarch64_insn_patch_text(&addr, &insn, 1);
9732cafd JL	40	}
	41
	42	void arch_jump_label_transform_static(struct jump_entry *entry,
	43	enum jump_label_type type)
	44	{
6ddae418 MR	45	/*
	46	* We use the architected A64 NOP in arch_static_branch, so there's no
	47	* need to patch an identical A64 NOP over the top of it here. The core
	48	* will call arch_jump_label_transform from a module notifier if the
	49	* NOP needs to be replaced by a branch.
	50	*/
9732cafd JL	51	}
	52
	53	#endif /* HAVE_JUMP_LABEL */