1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #include <byteswap.h> 3 #include <stdbool.h> 4 #include <stdio.h> 5 #include <stdlib.h> 6 #include <stdarg.h> 7 #include <string.h> 8 #include <sys/types.h> 9 #include <sys/stat.h> 10 #include <sys/mman.h> 11 #include <fcntl.h> 12 #include <unistd.h> 13 #include <elf.h> 14 #include "../../include/linux/module_symbol.h" 15 16 #include <list_types.h> 17 #include "elfconfig.h" 18 19 /* On BSD-alike OSes elf.h defines these according to host's word size */ 20 #undef ELF_ST_BIND 21 #undef ELF_ST_TYPE 22 #undef ELF_R_SYM 23 #undef ELF_R_TYPE 24 25 #if KERNEL_ELFCLASS == ELFCLASS32 26 27 #define Elf_Ehdr Elf32_Ehdr 28 #define Elf_Shdr Elf32_Shdr 29 #define Elf_Sym Elf32_Sym 30 #define Elf_Addr Elf32_Addr 31 #define Elf_Section Elf32_Half 32 #define ELF_ST_BIND ELF32_ST_BIND 33 #define ELF_ST_TYPE ELF32_ST_TYPE 34 35 #define Elf_Rel Elf32_Rel 36 #define Elf_Rela Elf32_Rela 37 #define ELF_R_SYM ELF32_R_SYM 38 #define ELF_R_TYPE ELF32_R_TYPE 39 #else 40 41 #define Elf_Ehdr Elf64_Ehdr 42 #define Elf_Shdr Elf64_Shdr 43 #define Elf_Sym Elf64_Sym 44 #define Elf_Addr Elf64_Addr 45 #define Elf_Section Elf64_Half 46 #define ELF_ST_BIND ELF64_ST_BIND 47 #define ELF_ST_TYPE ELF64_ST_TYPE 48 49 #define Elf_Rel Elf64_Rel 50 #define Elf_Rela Elf64_Rela 51 #define ELF_R_SYM ELF64_R_SYM 52 #define ELF_R_TYPE ELF64_R_TYPE 53 #endif 54 55 #define bswap(x) \ 56 ({ \ 57 _Static_assert(sizeof(x) == 1 || sizeof(x) == 2 || \ 58 sizeof(x) == 4 || sizeof(x) == 8, "bug"); \ 59 (typeof(x))(sizeof(x) == 2 ? bswap_16(x) : \ 60 sizeof(x) == 4 ? bswap_32(x) : \ 61 sizeof(x) == 8 ? bswap_64(x) : \ 62 x); \ 63 }) 64 65 #define TO_NATIVE(x) \ 66 (target_is_big_endian == host_is_big_endian ? x : bswap(x)) 67 68 #define __get_unaligned_t(type, ptr) ({ \ 69 const struct { type x; } __attribute__((__packed__)) *__pptr = \ 70 (typeof(__pptr))(ptr); \ 71 __pptr->x; \ 72 }) 73 74 #define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr)) 75 76 #define get_unaligned_native(ptr) \ 77 ({ \ 78 typeof(*(ptr)) _val = get_unaligned(ptr); \ 79 TO_NATIVE(_val); \ 80 }) 81 82 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) 83 84 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) 85 86 struct buffer { 87 char *p; 88 int pos; 89 int size; 90 }; 91 92 void __attribute__((format(printf, 2, 3))) 93 buf_printf(struct buffer *buf, const char *fmt, ...); 94 95 void 96 buf_write(struct buffer *buf, const char *s, int len); 97 98 /** 99 * struct module_alias - auto-generated MODULE_ALIAS() 100 * 101 * @node: linked to module::aliases 102 * @str: a string for MODULE_ALIAS() 103 */ 104 struct module_alias { 105 struct list_head node; 106 char str[]; 107 }; 108 109 /** 110 * struct module - represent a module (vmlinux or *.ko) 111 * 112 * @dump_file: path to the .symvers file if loaded from a file 113 * @aliases: list head for module_aliases 114 */ 115 struct module { 116 struct list_head list; 117 struct list_head exported_symbols; 118 struct list_head unresolved_symbols; 119 const char *dump_file; 120 bool is_gpl_compatible; 121 bool is_vmlinux; 122 bool seen; 123 bool has_init; 124 bool has_cleanup; 125 char srcversion[25]; 126 // Missing namespace dependencies 127 struct list_head missing_namespaces; 128 // Actual imported namespaces 129 struct list_head imported_namespaces; 130 struct list_head aliases; 131 char name[]; 132 }; 133 134 struct elf_info { 135 size_t size; 136 Elf_Ehdr *hdr; 137 Elf_Shdr *sechdrs; 138 Elf_Sym *symtab_start; 139 Elf_Sym *symtab_stop; 140 unsigned int export_symbol_secndx; /* .export_symbol section */ 141 char *strtab; 142 char *modinfo; 143 unsigned int modinfo_len; 144 145 /* support for 32bit section numbers */ 146 147 unsigned int num_sections; /* max_secindex + 1 */ 148 unsigned int secindex_strings; 149 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, 150 * take shndx from symtab_shndx_start[N] instead */ 151 Elf32_Word *symtab_shndx_start; 152 Elf32_Word *symtab_shndx_stop; 153 154 struct symsearch *symsearch; 155 }; 156 157 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ 158 static inline unsigned int get_secindex(const struct elf_info *info, 159 const Elf_Sym *sym) 160 { 161 unsigned int index = sym->st_shndx; 162 163 /* 164 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available 165 * in the .symtab_shndx section. 166 */ 167 if (index == SHN_XINDEX) 168 return info->symtab_shndx_start[sym - info->symtab_start]; 169 170 /* 171 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of 172 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real 173 * section indices. 174 */ 175 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE) 176 return index - SHN_HIRESERVE - 1; 177 178 return index; 179 } 180 181 /* 182 * If there's no name there, ignore it; likewise, ignore it if it's 183 * one of the magic symbols emitted used by current tools. 184 * 185 * Internal symbols created by tools should be ignored by modpost. 186 */ 187 static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym) 188 { 189 const char *name = elf->strtab + sym->st_name; 190 191 if (!name || !strlen(name)) 192 return false; 193 return !is_mapping_symbol(name); 194 } 195 196 /* symsearch.c */ 197 void symsearch_init(struct elf_info *elf); 198 void symsearch_finish(struct elf_info *elf); 199 Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr, 200 unsigned int secndx, bool allow_negative, 201 Elf_Addr min_distance); 202 203 /* file2alias.c */ 204 void handle_moddevtable(struct module *mod, struct elf_info *info, 205 Elf_Sym *sym, const char *symname); 206 207 /* sumversion.c */ 208 void get_src_version(const char *modname, char sum[], unsigned sumlen); 209 210 /* from modpost.c */ 211 extern bool target_is_big_endian; 212 extern bool host_is_big_endian; 213 char *read_text_file(const char *filename); 214 char *get_line(char **stringp); 215 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym); 216 217 void __attribute__((format(printf, 2, 3))) 218 modpost_log(bool is_error, const char *fmt, ...); 219 220 /* 221 * warn - show the given message, then let modpost continue running, still 222 * allowing modpost to exit successfully. This should be used when 223 * we still allow to generate vmlinux and modules. 224 * 225 * error - show the given message, then let modpost continue running, but fail 226 * in the end. This should be used when we should stop building vmlinux 227 * or modules, but we can continue running modpost to catch as many 228 * issues as possible. 229 * 230 * fatal - show the given message, and bail out immediately. This should be 231 * used when there is no point to continue running modpost. 232 */ 233 #define warn(fmt, args...) modpost_log(false, fmt, ##args) 234 #define error(fmt, args...) modpost_log(true, fmt, ##args) 235 #define fatal(fmt, args...) do { error(fmt, ##args); exit(1); } while (1) 236