arch/arm64/kernel/jump_label.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2013 Huawei Ltd.
   4  * Author: Jiang Liu <liuj97@gmail.com>
   5  *
   6  * Based on arch/arm/kernel/jump_label.c
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/jump_label.h>
  10 #include <asm/insn.h>
  11
  12 void arch_jump_label_transform(struct jump_entry *entry,
  13                                enum jump_label_type type)
  14 {
  15         void *addr = (void *)jump_entry_code(entry);
  16         u32 insn;
  17
  18         if (type == JUMP_LABEL_JMP) {
  19                 insn = aarch64_insn_gen_branch_imm(jump_entry_code(entry),
  20                                                    jump_entry_target(entry),
  21                                                    AARCH64_INSN_BRANCH_NOLINK);
  22         } else {
  23                 insn = aarch64_insn_gen_nop();
  24         }
  25
  26         aarch64_insn_patch_text_nosync(addr, insn);
  27 }
  28
  29 void arch_jump_label_transform_static(struct jump_entry *entry,
  30                                       enum jump_label_type type)
  31 {
  32         /*
  33          * We use the architected A64 NOP in arch_static_branch, so there's no
  34          * need to patch an identical A64 NOP over the top of it here. The core
  35          * will call arch_jump_label_transform from a module notifier if the
  36          * NOP needs to be replaced by a branch.
  37          */
  38 }