jump_label.c 1.5 KB

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  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. void arch_jump_label_transform(struct jump_entry *entry,
  23. enum jump_label_type type)
  24. {
  25. void *addr = (void *)entry->code;
  26. u32 insn;
  27. if (type == JUMP_LABEL_JMP) {
  28. insn = aarch64_insn_gen_branch_imm(entry->code,
  29. entry->target,
  30. AARCH64_INSN_BRANCH_NOLINK);
  31. } else {
  32. insn = aarch64_insn_gen_nop();
  33. }
  34. aarch64_insn_patch_text_nosync(addr, insn);
  35. }
  36. void arch_jump_label_transform_static(struct jump_entry *entry,
  37. enum jump_label_type type)
  38. {
  39. /*
  40. * We use the architected A64 NOP in arch_static_branch, so there's no
  41. * need to patch an identical A64 NOP over the top of it here. The core
  42. * will call arch_jump_label_transform from a module notifier if the
  43. * NOP needs to be replaced by a branch.
  44. */
  45. }