| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-or-later |
| 3 | * |
| 4 | * Copyright (C) 2015 Antoine Busque <abusque@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #ifndef _LTTNG_UST_ELF_H |
| 8 | #define _LTTNG_UST_ELF_H |
| 9 | |
| 10 | #include <stdlib.h> |
| 11 | #include <stdint.h> |
| 12 | #include <stdio.h> |
| 13 | #include <elf.h> |
| 14 | #include <lttng/ust-endian.h> |
| 15 | |
| 16 | /* |
| 17 | * Determine native endianness in order to convert when reading an ELF |
| 18 | * file if there is a mismatch. |
| 19 | */ |
| 20 | #if BYTE_ORDER == LITTLE_ENDIAN |
| 21 | #define NATIVE_ELF_ENDIANNESS ELFDATA2LSB |
| 22 | #else |
| 23 | #define NATIVE_ELF_ENDIANNESS ELFDATA2MSB |
| 24 | #endif |
| 25 | |
| 26 | /* |
| 27 | * The size in bytes of the debug link CRC as contained in an ELF |
| 28 | * section. |
| 29 | */ |
| 30 | #define ELF_CRC_SIZE 4 |
| 31 | /* |
| 32 | * ELF notes are aligned on 4 bytes. ref: ELF specification version |
| 33 | * 1.1 p. 2-5. |
| 34 | */ |
| 35 | #define ELF_NOTE_ENTRY_ALIGN 4 |
| 36 | /* |
| 37 | * Within an ELF note, the `desc` field is also aligned on 4 |
| 38 | * bytes. ref: ELF specification version 1.1 p. 2-5. |
| 39 | */ |
| 40 | #define ELF_NOTE_DESC_ALIGN 4 |
| 41 | |
| 42 | #define bswap(x) \ |
| 43 | do { \ |
| 44 | switch (sizeof(x)) { \ |
| 45 | case 8: \ |
| 46 | x = bswap_64(x); \ |
| 47 | break; \ |
| 48 | case 4: \ |
| 49 | x = bswap_32(x); \ |
| 50 | break; \ |
| 51 | case 2: \ |
| 52 | x = bswap_16(x); \ |
| 53 | break; \ |
| 54 | case 1: \ |
| 55 | break; \ |
| 56 | default: \ |
| 57 | abort(); \ |
| 58 | } \ |
| 59 | } while (0) |
| 60 | |
| 61 | #define bswap_phdr(phdr) \ |
| 62 | do { \ |
| 63 | bswap((phdr).p_type); \ |
| 64 | bswap((phdr).p_offset); \ |
| 65 | bswap((phdr).p_filesz); \ |
| 66 | bswap((phdr).p_memsz); \ |
| 67 | bswap((phdr).p_align); \ |
| 68 | bswap((phdr).p_vaddr); \ |
| 69 | } while (0) |
| 70 | |
| 71 | #define bswap_shdr(shdr) \ |
| 72 | do { \ |
| 73 | bswap((shdr).sh_name); \ |
| 74 | bswap((shdr).sh_type); \ |
| 75 | bswap((shdr).sh_flags); \ |
| 76 | bswap((shdr).sh_addr); \ |
| 77 | bswap((shdr).sh_offset); \ |
| 78 | bswap((shdr).sh_size); \ |
| 79 | bswap((shdr).sh_link); \ |
| 80 | bswap((shdr).sh_info); \ |
| 81 | bswap((shdr).sh_addralign); \ |
| 82 | bswap((shdr).sh_entsize); \ |
| 83 | } while (0) |
| 84 | |
| 85 | #define bswap_ehdr(ehdr) \ |
| 86 | do { \ |
| 87 | bswap((ehdr).e_type); \ |
| 88 | bswap((ehdr).e_machine); \ |
| 89 | bswap((ehdr).e_version); \ |
| 90 | bswap((ehdr).e_entry); \ |
| 91 | bswap((ehdr).e_phoff); \ |
| 92 | bswap((ehdr).e_shoff); \ |
| 93 | bswap((ehdr).e_flags); \ |
| 94 | bswap((ehdr).e_ehsize); \ |
| 95 | bswap((ehdr).e_phentsize); \ |
| 96 | bswap((ehdr).e_phnum); \ |
| 97 | bswap((ehdr).e_shentsize); \ |
| 98 | bswap((ehdr).e_shnum); \ |
| 99 | bswap((ehdr).e_shstrndx); \ |
| 100 | } while (0) |
| 101 | |
| 102 | #define copy_phdr(src_phdr, dst_phdr) \ |
| 103 | do { \ |
| 104 | (dst_phdr).p_type = (src_phdr).p_type; \ |
| 105 | (dst_phdr).p_offset = (src_phdr).p_offset; \ |
| 106 | (dst_phdr).p_filesz = (src_phdr).p_filesz; \ |
| 107 | (dst_phdr).p_memsz = (src_phdr).p_memsz; \ |
| 108 | (dst_phdr).p_align = (src_phdr).p_align; \ |
| 109 | (dst_phdr).p_vaddr = (src_phdr).p_vaddr; \ |
| 110 | } while (0) |
| 111 | |
| 112 | #define copy_shdr(src_shdr, dst_shdr) \ |
| 113 | do { \ |
| 114 | (dst_shdr).sh_name = (src_shdr).sh_name; \ |
| 115 | (dst_shdr).sh_type = (src_shdr).sh_type; \ |
| 116 | (dst_shdr).sh_flags = (src_shdr).sh_flags; \ |
| 117 | (dst_shdr).sh_addr = (src_shdr).sh_addr; \ |
| 118 | (dst_shdr).sh_offset = (src_shdr).sh_offset; \ |
| 119 | (dst_shdr).sh_size = (src_shdr).sh_size; \ |
| 120 | (dst_shdr).sh_link = (src_shdr).sh_link; \ |
| 121 | (dst_shdr).sh_info = (src_shdr).sh_info; \ |
| 122 | (dst_shdr).sh_addralign = (src_shdr).sh_addralign; \ |
| 123 | (dst_shdr).sh_entsize = (src_shdr).sh_entsize; \ |
| 124 | } while (0) |
| 125 | |
| 126 | #define copy_ehdr(src_ehdr, dst_ehdr) \ |
| 127 | do { \ |
| 128 | (dst_ehdr).e_type = (src_ehdr).e_type; \ |
| 129 | (dst_ehdr).e_machine = (src_ehdr).e_machine; \ |
| 130 | (dst_ehdr).e_version = (src_ehdr).e_version; \ |
| 131 | (dst_ehdr).e_entry = (src_ehdr).e_entry; \ |
| 132 | (dst_ehdr).e_phoff = (src_ehdr).e_phoff; \ |
| 133 | (dst_ehdr).e_shoff = (src_ehdr).e_shoff; \ |
| 134 | (dst_ehdr).e_flags = (src_ehdr).e_flags; \ |
| 135 | (dst_ehdr).e_ehsize = (src_ehdr).e_ehsize; \ |
| 136 | (dst_ehdr).e_phentsize = (src_ehdr).e_phentsize; \ |
| 137 | (dst_ehdr).e_phnum = (src_ehdr).e_phnum; \ |
| 138 | (dst_ehdr).e_shentsize = (src_ehdr).e_shentsize; \ |
| 139 | (dst_ehdr).e_shnum = (src_ehdr).e_shnum; \ |
| 140 | (dst_ehdr).e_shstrndx = (src_ehdr).e_shstrndx; \ |
| 141 | } while (0) |
| 142 | |
| 143 | struct lttng_ust_elf_ehdr { |
| 144 | uint16_t e_type; |
| 145 | uint16_t e_machine; |
| 146 | uint32_t e_version; |
| 147 | uint64_t e_entry; |
| 148 | uint64_t e_phoff; |
| 149 | uint64_t e_shoff; |
| 150 | uint32_t e_flags; |
| 151 | uint16_t e_ehsize; |
| 152 | uint16_t e_phentsize; |
| 153 | uint16_t e_phnum; |
| 154 | uint16_t e_shentsize; |
| 155 | uint16_t e_shnum; |
| 156 | uint16_t e_shstrndx; |
| 157 | }; |
| 158 | |
| 159 | struct lttng_ust_elf_phdr { |
| 160 | uint32_t p_type; |
| 161 | uint64_t p_offset; |
| 162 | uint64_t p_filesz; |
| 163 | uint64_t p_memsz; |
| 164 | uint64_t p_align; |
| 165 | uint64_t p_vaddr; |
| 166 | }; |
| 167 | |
| 168 | struct lttng_ust_elf_shdr { |
| 169 | uint32_t sh_name; |
| 170 | uint32_t sh_type; |
| 171 | uint64_t sh_flags; |
| 172 | uint64_t sh_addr; |
| 173 | uint64_t sh_offset; |
| 174 | uint64_t sh_size; |
| 175 | uint32_t sh_link; |
| 176 | uint32_t sh_info; |
| 177 | uint64_t sh_addralign; |
| 178 | uint64_t sh_entsize; |
| 179 | }; |
| 180 | |
| 181 | struct lttng_ust_elf_nhdr { |
| 182 | uint32_t n_namesz; |
| 183 | uint32_t n_descsz; |
| 184 | uint32_t n_type; |
| 185 | }; |
| 186 | |
| 187 | struct lttng_ust_elf { |
| 188 | /* Offset in bytes to start of section names string table. */ |
| 189 | off_t section_names_offset; |
| 190 | /* Size in bytes of section names string table. */ |
| 191 | size_t section_names_size; |
| 192 | char *path; |
| 193 | int fd; |
| 194 | struct lttng_ust_elf_ehdr *ehdr; |
| 195 | uint8_t bitness; |
| 196 | uint8_t endianness; |
| 197 | }; |
| 198 | |
| 199 | static inline |
| 200 | int is_elf_32_bit(struct lttng_ust_elf *elf) |
| 201 | { |
| 202 | return elf->bitness == ELFCLASS32; |
| 203 | } |
| 204 | |
| 205 | static inline |
| 206 | int is_elf_native_endian(struct lttng_ust_elf *elf) |
| 207 | { |
| 208 | return elf->endianness == NATIVE_ELF_ENDIANNESS; |
| 209 | } |
| 210 | |
| 211 | struct lttng_ust_elf *lttng_ust_elf_create(const char *path); |
| 212 | void lttng_ust_elf_destroy(struct lttng_ust_elf *elf); |
| 213 | uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf); |
| 214 | int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz); |
| 215 | int lttng_ust_elf_get_build_id(struct lttng_ust_elf *elf, uint8_t **build_id, |
| 216 | size_t *length, int *found); |
| 217 | int lttng_ust_elf_get_debug_link(struct lttng_ust_elf *elf, char **filename, |
| 218 | uint32_t *crc, int *found); |
| 219 | |
| 220 | #endif /* _LTTNG_UST_ELF_H */ |