1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com> 4 */ 5 6#ifndef _OBJTOOL_ELF_H 7#define _OBJTOOL_ELF_H 8 9#include <stdio.h> 10#include <gelf.h> 11#include <linux/list.h> 12#include <linux/hashtable.h> 13#include <linux/rbtree.h> 14#include <linux/jhash.h> 15 16#ifdef LIBELF_USE_DEPRECATED 17# define elf_getshdrnum elf_getshnum 18# define elf_getshdrstrndx elf_getshstrndx 19#endif 20 21/* 22 * Fallback for systems without this "read, mmaping if possible" cmd. 23 */ 24#ifndef ELF_C_READ_MMAP 25#define ELF_C_READ_MMAP ELF_C_READ 26#endif 27 28struct section { 29 struct list_head list; 30 struct hlist_node hash; 31 struct hlist_node name_hash; 32 GElf_Shdr sh; 33 struct rb_root symbol_tree; 34 struct list_head symbol_list; 35 struct list_head reloc_list; 36 struct section *base, *reloc; 37 struct symbol *sym; 38 Elf_Data *data; 39 char *name; 40 int idx; 41 unsigned int len; 42 bool changed, text, rodata, noinstr; 43}; 44 45struct symbol { 46 struct list_head list; 47 struct rb_node node; 48 struct hlist_node hash; 49 struct hlist_node name_hash; 50 GElf_Sym sym; 51 struct section *sec; 52 char *name; 53 unsigned int idx; 54 unsigned char bind, type; 55 unsigned long offset; 56 unsigned int len; 57 struct symbol *pfunc, *cfunc, *alias; 58 u8 uaccess_safe : 1; 59 u8 static_call_tramp : 1; 60 u8 retpoline_thunk : 1; 61 u8 return_thunk : 1; 62 u8 fentry : 1; 63 u8 kcov : 1; 64 u8 embedded_insn : 1; 65}; 66 67struct reloc { 68 struct list_head list; 69 struct hlist_node hash; 70 union { 71 GElf_Rela rela; 72 GElf_Rel rel; 73 }; 74 struct section *sec; 75 struct symbol *sym; 76 unsigned long offset; 77 unsigned int type; 78 s64 addend; 79 int idx; 80 bool jump_table_start; 81}; 82 83#define ELF_HASH_BITS 20 84 85struct elf { 86 Elf *elf; 87 GElf_Ehdr ehdr; 88 int fd; 89 bool changed; 90 char *name; 91 struct list_head sections; 92 DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS); 93 DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS); 94 DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS); 95 DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS); 96 DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS); 97}; 98 99#define OFFSET_STRIDE_BITS 4 100#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) 101#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) 102 103#define for_offset_range(_offset, _start, _end) \ 104 for (_offset = ((_start) & OFFSET_STRIDE_MASK); \ 105 _offset >= ((_start) & OFFSET_STRIDE_MASK) && \ 106 _offset <= ((_end) & OFFSET_STRIDE_MASK); \ 107 _offset += OFFSET_STRIDE) 108 109static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) 110{ 111 u32 ol, oh, idx = sec->idx; 112 113 offset &= OFFSET_STRIDE_MASK; 114 115 ol = offset; 116 oh = (offset >> 16) >> 16; 117 118 __jhash_mix(ol, oh, idx); 119 120 return ol; 121} 122 123static inline u32 reloc_hash(struct reloc *reloc) 124{ 125 return sec_offset_hash(reloc->sec, reloc->offset); 126} 127 128struct elf *elf_open_read(const char *name, int flags); 129struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); 130 131int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, 132 unsigned int type, struct symbol *sym, s64 addend); 133int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, 134 unsigned long offset, unsigned int type, 135 struct section *insn_sec, unsigned long insn_off); 136 137int elf_write_insn(struct elf *elf, struct section *sec, 138 unsigned long offset, unsigned int len, 139 const char *insn); 140int elf_write_reloc(struct elf *elf, struct reloc *reloc); 141int elf_write(struct elf *elf); 142void elf_close(struct elf *elf); 143 144struct section *find_section_by_name(const struct elf *elf, const char *name); 145struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); 146struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); 147struct symbol *find_symbol_by_name(const struct elf *elf, const char *name); 148struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset); 149struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset); 150struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, 151 unsigned long offset, unsigned int len); 152struct symbol *find_func_containing(struct section *sec, unsigned long offset); 153 154#define for_each_sec(file, sec) \ 155 list_for_each_entry(sec, &file->elf->sections, list) 156 157#endif /* _OBJTOOL_ELF_H */ 158