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 ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) 69 70 struct buffer { 71 char *p; 72 int pos; 73 int size; 74 }; 75 76 void __attribute__((format(printf, 2, 3))) 77 buf_printf(struct buffer *buf, const char *fmt, ...); 78 79 void 80 buf_write(struct buffer *buf, const char *s, int len); 81 82 struct module { 83 struct list_head list; 84 struct list_head exported_symbols; 85 struct list_head unresolved_symbols; 86 bool is_gpl_compatible; 87 bool from_dump; /* true if module was loaded from *.symvers */ 88 bool is_vmlinux; 89 bool seen; 90 bool has_init; 91 bool has_cleanup; 92 struct buffer dev_table_buf; 93 char srcversion[25]; 94 // Missing namespace dependencies 95 struct list_head missing_namespaces; 96 // Actual imported namespaces 97 struct list_head imported_namespaces; 98 char name[]; 99 }; 100 101 struct elf_info { 102 size_t size; 103 Elf_Ehdr *hdr; 104 Elf_Shdr *sechdrs; 105 Elf_Sym *symtab_start; 106 Elf_Sym *symtab_stop; 107 unsigned int export_symbol_secndx; /* .export_symbol section */ 108 char *strtab; 109 char *modinfo; 110 unsigned int modinfo_len; 111 112 /* support for 32bit section numbers */ 113 114 unsigned int num_sections; /* max_secindex + 1 */ 115 unsigned int secindex_strings; 116 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, 117 * take shndx from symtab_shndx_start[N] instead */ 118 Elf32_Word *symtab_shndx_start; 119 Elf32_Word *symtab_shndx_stop; 120 121 struct symsearch *symsearch; 122 }; 123 124 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ get_secindex(const struct elf_info * info,const Elf_Sym * sym)125 static inline unsigned int get_secindex(const struct elf_info *info, 126 const Elf_Sym *sym) 127 { 128 unsigned int index = sym->st_shndx; 129 130 /* 131 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available 132 * in the .symtab_shndx section. 133 */ 134 if (index == SHN_XINDEX) 135 return info->symtab_shndx_start[sym - info->symtab_start]; 136 137 /* 138 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of 139 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real 140 * section indices. 141 */ 142 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE) 143 return index - SHN_HIRESERVE - 1; 144 145 return index; 146 } 147 148 /* 149 * If there's no name there, ignore it; likewise, ignore it if it's 150 * one of the magic symbols emitted used by current tools. 151 * 152 * Internal symbols created by tools should be ignored by modpost. 153 */ is_valid_name(struct elf_info * elf,Elf_Sym * sym)154 static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym) 155 { 156 const char *name = elf->strtab + sym->st_name; 157 158 if (!name || !strlen(name)) 159 return false; 160 return !is_mapping_symbol(name); 161 } 162 163 /* symsearch.c */ 164 void symsearch_init(struct elf_info *elf); 165 void symsearch_finish(struct elf_info *elf); 166 Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr, 167 unsigned int secndx, bool allow_negative, 168 Elf_Addr min_distance); 169 170 /* file2alias.c */ 171 void handle_moddevtable(struct module *mod, struct elf_info *info, 172 Elf_Sym *sym, const char *symname); 173 void add_moddevtable(struct buffer *buf, struct module *mod); 174 175 /* sumversion.c */ 176 void get_src_version(const char *modname, char sum[], unsigned sumlen); 177 178 /* from modpost.c */ 179 extern bool target_is_big_endian; 180 extern bool host_is_big_endian; 181 char *read_text_file(const char *filename); 182 char *get_line(char **stringp); 183 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym); 184 185 void __attribute__((format(printf, 2, 3))) 186 modpost_log(bool is_error, const char *fmt, ...); 187 188 /* 189 * warn - show the given message, then let modpost continue running, still 190 * allowing modpost to exit successfully. This should be used when 191 * we still allow to generate vmlinux and modules. 192 * 193 * error - show the given message, then let modpost continue running, but fail 194 * in the end. This should be used when we should stop building vmlinux 195 * or modules, but we can continue running modpost to catch as many 196 * issues as possible. 197 * 198 * fatal - show the given message, and bail out immediately. This should be 199 * used when there is no point to continue running modpost. 200 */ 201 #define warn(fmt, args...) modpost_log(false, fmt, ##args) 202 #define error(fmt, args...) modpost_log(true, fmt, ##args) 203 #define fatal(fmt, args...) do { error(fmt, ##args); exit(1); } while (1) 204