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 28 struct 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 bool changed, text, rodata, noinstr; 42 }; 43 44 struct symbol { 45 struct list_head list; 46 struct rb_node node; 47 struct hlist_node hash; 48 struct hlist_node name_hash; 49 GElf_Sym sym; 50 struct section *sec; 51 char *name; 52 unsigned int idx; 53 unsigned char bind, type; 54 unsigned long offset; 55 unsigned int len; 56 struct symbol *pfunc, *cfunc, *alias; 57 u8 uaccess_safe : 1; 58 u8 static_call_tramp : 1; 59 u8 retpoline_thunk : 1; 60 u8 fentry : 1; 61 u8 profiling_func : 1; 62 struct list_head pv_target; 63 }; 64 65 struct reloc { 66 struct list_head list; 67 struct hlist_node hash; 68 union { 69 GElf_Rela rela; 70 GElf_Rel rel; 71 }; 72 struct section *sec; 73 struct symbol *sym; 74 unsigned long offset; 75 unsigned int type; 76 int addend; 77 int idx; 78 bool jump_table_start; 79 }; 80 81 #define ELF_HASH_BITS 20 82 83 struct elf { 84 Elf *elf; 85 GElf_Ehdr ehdr; 86 int fd; 87 bool changed; 88 char *name; 89 unsigned int text_size; 90 struct list_head sections; 91 92 int symbol_bits; 93 int symbol_name_bits; 94 int section_bits; 95 int section_name_bits; 96 int reloc_bits; 97 98 struct hlist_head *symbol_hash; 99 struct hlist_head *symbol_name_hash; 100 struct hlist_head *section_hash; 101 struct hlist_head *section_name_hash; 102 struct hlist_head *reloc_hash; 103 }; 104 105 #define OFFSET_STRIDE_BITS 4 106 #define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS) 107 #define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1)) 108 109 #define for_offset_range(_offset, _start, _end) \ 110 for (_offset = ((_start) & OFFSET_STRIDE_MASK); \ 111 _offset >= ((_start) & OFFSET_STRIDE_MASK) && \ 112 _offset <= ((_end) & OFFSET_STRIDE_MASK); \ 113 _offset += OFFSET_STRIDE) 114 115 static inline u32 sec_offset_hash(struct section *sec, unsigned long offset) 116 { 117 u32 ol, oh, idx = sec->idx; 118 119 offset &= OFFSET_STRIDE_MASK; 120 121 ol = offset; 122 oh = (offset >> 16) >> 16; 123 124 __jhash_mix(ol, oh, idx); 125 126 return ol; 127 } 128 129 static inline u32 reloc_hash(struct reloc *reloc) 130 { 131 return sec_offset_hash(reloc->sec, reloc->offset); 132 } 133 134 struct elf *elf_open_read(const char *name, int flags); 135 struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); 136 137 int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, 138 unsigned int type, struct symbol *sym, int addend); 139 int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, 140 unsigned long offset, unsigned int type, 141 struct section *insn_sec, unsigned long insn_off); 142 143 int elf_write_insn(struct elf *elf, struct section *sec, 144 unsigned long offset, unsigned int len, 145 const char *insn); 146 int elf_write_reloc(struct elf *elf, struct reloc *reloc); 147 int elf_write(struct elf *elf); 148 void elf_close(struct elf *elf); 149 150 struct section *find_section_by_name(const struct elf *elf, const char *name); 151 struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); 152 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); 153 struct symbol *find_symbol_by_name(const struct elf *elf, const char *name); 154 struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset); 155 struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset); 156 struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, 157 unsigned long offset, unsigned int len); 158 struct symbol *find_func_containing(struct section *sec, unsigned long offset); 159 160 #define for_each_sec(file, sec) \ 161 list_for_each_entry(sec, &file->elf->sections, list) 162 163 #endif /* _OBJTOOL_ELF_H */ 164