arch/arm64/include/asm/module.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2012 ARM Ltd.
   4  */
   5 #ifndef __ASM_MODULE_H
   6 #define __ASM_MODULE_H
   7
   8 #include <asm-generic/module.h>
   9
  10 #ifdef CONFIG_ARM64_MODULE_PLTS
  11 struct mod_plt_sec {
  12         int                     plt_shndx;
  13         int                     plt_num_entries;
  14         int                     plt_max_entries;
  15 };
  16
  17 struct mod_arch_specific {
  18         struct mod_plt_sec      core;
  19         struct mod_plt_sec      init;
  20
  21         /* for CONFIG_DYNAMIC_FTRACE */
  22         struct plt_entry        *ftrace_trampolines;
  23 };
  24 #endif
  25
  26 u64 module_emit_plt_entry(struct module *mod, Elf64_Shdr *sechdrs,
  27                           void *loc, const Elf64_Rela *rela,
  28                           Elf64_Sym *sym);
  29
  30 u64 module_emit_veneer_for_adrp(struct module *mod, Elf64_Shdr *sechdrs,
  31                                 void *loc, u64 val);
  32
  33 #ifdef CONFIG_RANDOMIZE_BASE
  34 extern u64 module_alloc_base;
  35 #else
  36 #define module_alloc_base       ((u64)_etext - MODULES_VSIZE)
  37 #endif
  38
  39 struct plt_entry {
  40         /*
  41          * A program that conforms to the AArch64 Procedure Call Standard
  42          * (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or
  43          * IP1 (x17) may be inserted at any branch instruction that is
  44          * exposed to a relocation that supports long branches. Since that
  45          * is exactly what we are dealing with here, we are free to use x16
  46          * as a scratch register in the PLT veneers.
  47          */
  48         __le32  adrp;   /* adrp x16, ....                       */
  49         __le32  add;    /* add  x16, x16, #0x....               */
  50         __le32  br;     /* br   x16                             */
  51 };
  52
  53 static inline bool is_forbidden_offset_for_adrp(void *place)
  54 {
  55         return IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) &&
  56                cpus_have_const_cap(ARM64_WORKAROUND_843419) &&
  57                ((u64)place & 0xfff) >= 0xff8;
  58 }
  59
  60 struct plt_entry get_plt_entry(u64 dst, void *pc);
  61 bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b);
  62
  63 static inline bool plt_entry_is_initialized(const struct plt_entry *e)
  64 {
  65         return e->adrp || e->add || e->br;
  66 }
  67
  68 #endif /* __ASM_MODULE_H */