1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #include <stdbool.h> 3 #include <stdio.h> 4 #include <stdlib.h> 5 #include <stdarg.h> 6 #include <string.h> 7 #include <sys/types.h> 8 #include <sys/stat.h> 9 #include <sys/mman.h> 10 #include <fcntl.h> 11 #include <unistd.h> 12 #include <elf.h> 13 14 #include "list.h" 15 #include "elfconfig.h" 16 17 /* On BSD-alike OSes elf.h defines these according to host's word size */ 18 #undef ELF_ST_BIND 19 #undef ELF_ST_TYPE 20 #undef ELF_R_SYM 21 #undef ELF_R_TYPE 22 23 #if KERNEL_ELFCLASS == ELFCLASS32 24 25 #define Elf_Ehdr Elf32_Ehdr 26 #define Elf_Shdr Elf32_Shdr 27 #define Elf_Sym Elf32_Sym 28 #define Elf_Addr Elf32_Addr 29 #define Elf_Section Elf32_Half 30 #define ELF_ST_BIND ELF32_ST_BIND 31 #define ELF_ST_TYPE ELF32_ST_TYPE 32 33 #define Elf_Rel Elf32_Rel 34 #define Elf_Rela Elf32_Rela 35 #define ELF_R_SYM ELF32_R_SYM 36 #define ELF_R_TYPE ELF32_R_TYPE 37 #else 38 39 #define Elf_Ehdr Elf64_Ehdr 40 #define Elf_Shdr Elf64_Shdr 41 #define Elf_Sym Elf64_Sym 42 #define Elf_Addr Elf64_Addr 43 #define Elf_Section Elf64_Half 44 #define ELF_ST_BIND ELF64_ST_BIND 45 #define ELF_ST_TYPE ELF64_ST_TYPE 46 47 #define Elf_Rel Elf64_Rel 48 #define Elf_Rela Elf64_Rela 49 #define ELF_R_SYM ELF64_R_SYM 50 #define ELF_R_TYPE ELF64_R_TYPE 51 #endif 52 53 #if KERNEL_ELFDATA != HOST_ELFDATA 54 55 static inline void __endian(const void *src, void *dest, unsigned int size) 56 { 57 unsigned int i; 58 for (i = 0; i < size; i++) 59 ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1]; 60 } 61 62 #define TO_NATIVE(x) \ 63 ({ \ 64 typeof(x) __x; \ 65 __endian(&(x), &(__x), sizeof(__x)); \ 66 __x; \ 67 }) 68 69 #else /* endianness matches */ 70 71 #define TO_NATIVE(x) (x) 72 73 #endif 74 75 #define NOFAIL(ptr) do_nofail((ptr), #ptr) 76 77 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) 78 79 void *do_nofail(void *ptr, const char *expr); 80 81 struct buffer { 82 char *p; 83 int pos; 84 int size; 85 }; 86 87 void __attribute__((format(printf, 2, 3))) 88 buf_printf(struct buffer *buf, const char *fmt, ...); 89 90 void 91 buf_write(struct buffer *buf, const char *s, int len); 92 93 struct module { 94 struct list_head list; 95 struct list_head exported_symbols; 96 struct list_head unresolved_symbols; 97 bool is_gpl_compatible; 98 bool from_dump; /* true if module was loaded from *.symvers */ 99 bool is_vmlinux; 100 bool seen; 101 bool has_init; 102 bool has_cleanup; 103 struct buffer dev_table_buf; 104 char srcversion[25]; 105 // Missing namespace dependencies 106 struct list_head missing_namespaces; 107 // Actual imported namespaces 108 struct list_head imported_namespaces; 109 char name[]; 110 }; 111 112 struct elf_info { 113 size_t size; 114 Elf_Ehdr *hdr; 115 Elf_Shdr *sechdrs; 116 Elf_Sym *symtab_start; 117 Elf_Sym *symtab_stop; 118 unsigned int export_symbol_secndx; /* .export_symbol section */ 119 char *strtab; 120 char *modinfo; 121 unsigned int modinfo_len; 122 123 /* support for 32bit section numbers */ 124 125 unsigned int num_sections; /* max_secindex + 1 */ 126 unsigned int secindex_strings; 127 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, 128 * take shndx from symtab_shndx_start[N] instead */ 129 Elf32_Word *symtab_shndx_start; 130 Elf32_Word *symtab_shndx_stop; 131 }; 132 133 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ 134 static inline unsigned int get_secindex(const struct elf_info *info, 135 const Elf_Sym *sym) 136 { 137 unsigned int index = sym->st_shndx; 138 139 /* 140 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available 141 * in the .symtab_shndx section. 142 */ 143 if (index == SHN_XINDEX) 144 return info->symtab_shndx_start[sym - info->symtab_start]; 145 146 /* 147 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of 148 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real 149 * section indices. 150 */ 151 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE) 152 return index - SHN_HIRESERVE - 1; 153 154 return index; 155 } 156 157 /* file2alias.c */ 158 void handle_moddevtable(struct module *mod, struct elf_info *info, 159 Elf_Sym *sym, const char *symname); 160 void add_moddevtable(struct buffer *buf, struct module *mod); 161 162 /* sumversion.c */ 163 void get_src_version(const char *modname, char sum[], unsigned sumlen); 164 165 /* from modpost.c */ 166 char *read_text_file(const char *filename); 167 char *get_line(char **stringp); 168 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym); 169 170 enum loglevel { 171 LOG_WARN, 172 LOG_ERROR, 173 LOG_FATAL 174 }; 175 176 void modpost_log(enum loglevel loglevel, const char *fmt, ...); 177 178 /* 179 * warn - show the given message, then let modpost continue running, still 180 * allowing modpost to exit successfully. This should be used when 181 * we still allow to generate vmlinux and modules. 182 * 183 * error - show the given message, then let modpost continue running, but fail 184 * in the end. This should be used when we should stop building vmlinux 185 * or modules, but we can continue running modpost to catch as many 186 * issues as possible. 187 * 188 * fatal - show the given message, and bail out immediately. This should be 189 * used when there is no point to continue running modpost. 190 */ 191 #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args) 192 #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args) 193 #define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args) 194