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 <[email protected]>
   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 #include <asm/patching.h>
  12
  13 void arch_jump_label_transform(struct jump_entry *entry,
  14                                enum jump_label_type type)
  15 {
  16         void *addr = (void *)jump_entry_code(entry);
  17         u32 insn;
  18
  19         if (type == JUMP_LABEL_JMP) {
  20                 insn = aarch64_insn_gen_branch_imm(jump_entry_code(entry),
  21                                                    jump_entry_target(entry),
  22                                                    AARCH64_INSN_BRANCH_NOLINK);
  23         } else {
  24                 insn = aarch64_insn_gen_nop();
  25         }
  26
  27         aarch64_insn_patch_text_nosync(addr, insn);
  28 }
  29
  30 void arch_jump_label_transform_static(struct jump_entry *entry,
  31                                       enum jump_label_type type)
  32 {
  33         /*
  34          * We use the architected A64 NOP in arch_static_branch, so there's no
  35          * need to patch an identical A64 NOP over the top of it here. The core
  36          * will call arch_jump_label_transform from a module notifier if the
  37          * NOP needs to be replaced by a branch.
  38          */
  39 }