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 /* The 64-bit MIPS ELF ABI uses an unusual reloc format. */ 54 typedef struct 55 { 56 Elf32_Word r_sym; /* Symbol index */ 57 unsigned char r_ssym; /* Special symbol for 2nd relocation */ 58 unsigned char r_type3; /* 3rd relocation type */ 59 unsigned char r_type2; /* 2nd relocation type */ 60 unsigned char r_type1; /* 1st relocation type */ 61 } _Elf64_Mips_R_Info; 62 63 typedef union 64 { 65 Elf64_Xword r_info_number; 66 _Elf64_Mips_R_Info r_info_fields; 67 } _Elf64_Mips_R_Info_union; 68 69 #define ELF64_MIPS_R_SYM(i) \ 70 ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym) 71 72 #define ELF64_MIPS_R_TYPE(i) \ 73 ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1) 74 75 #if KERNEL_ELFDATA != HOST_ELFDATA 76 77 static inline void __endian(const void *src, void *dest, unsigned int size) 78 { 79 unsigned int i; 80 for (i = 0; i < size; i++) 81 ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1]; 82 } 83 84 #define TO_NATIVE(x) \ 85 ({ \ 86 typeof(x) __x; \ 87 __endian(&(x), &(__x), sizeof(__x)); \ 88 __x; \ 89 }) 90 91 #else /* endianness matches */ 92 93 #define TO_NATIVE(x) (x) 94 95 #endif 96 97 #define NOFAIL(ptr) do_nofail((ptr), #ptr) 98 99 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) 100 101 void *do_nofail(void *ptr, const char *expr); 102 103 struct buffer { 104 char *p; 105 int pos; 106 int size; 107 }; 108 109 void __attribute__((format(printf, 2, 3))) 110 buf_printf(struct buffer *buf, const char *fmt, ...); 111 112 void 113 buf_write(struct buffer *buf, const char *s, int len); 114 115 struct module { 116 struct list_head list; 117 struct list_head exported_symbols; 118 struct list_head unresolved_symbols; 119 bool is_gpl_compatible; 120 bool from_dump; /* true if module was loaded from *.symvers */ 121 bool is_vmlinux; 122 bool seen; 123 bool has_init; 124 bool has_cleanup; 125 struct buffer dev_table_buf; 126 char srcversion[25]; 127 // Missing namespace dependencies 128 struct list_head missing_namespaces; 129 // Actual imported namespaces 130 struct list_head imported_namespaces; 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 char *strtab; 141 char *modinfo; 142 unsigned int modinfo_len; 143 144 /* support for 32bit section numbers */ 145 146 unsigned int num_sections; /* max_secindex + 1 */ 147 unsigned int secindex_strings; 148 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, 149 * take shndx from symtab_shndx_start[N] instead */ 150 Elf32_Word *symtab_shndx_start; 151 Elf32_Word *symtab_shndx_stop; 152 }; 153 154 static inline int is_shndx_special(unsigned int i) 155 { 156 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE; 157 } 158 159 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ 160 static inline unsigned int get_secindex(const struct elf_info *info, 161 const Elf_Sym *sym) 162 { 163 unsigned int index = sym->st_shndx; 164 165 /* 166 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available 167 * in the .symtab_shndx section. 168 */ 169 if (index == SHN_XINDEX) 170 return info->symtab_shndx_start[sym - info->symtab_start]; 171 172 /* 173 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of 174 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real 175 * section indices. 176 */ 177 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE) 178 return index - SHN_HIRESERVE - 1; 179 180 return index; 181 } 182 183 /* file2alias.c */ 184 void handle_moddevtable(struct module *mod, struct elf_info *info, 185 Elf_Sym *sym, const char *symname); 186 void add_moddevtable(struct buffer *buf, struct module *mod); 187 188 /* sumversion.c */ 189 void get_src_version(const char *modname, char sum[], unsigned sumlen); 190 191 /* from modpost.c */ 192 char *read_text_file(const char *filename); 193 char *get_line(char **stringp); 194 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym); 195 196 enum loglevel { 197 LOG_WARN, 198 LOG_ERROR, 199 LOG_FATAL 200 }; 201 202 void modpost_log(enum loglevel loglevel, const char *fmt, ...); 203 204 /* 205 * warn - show the given message, then let modpost continue running, still 206 * allowing modpost to exit successfully. This should be used when 207 * we still allow to generate vmlinux and modules. 208 * 209 * error - show the given message, then let modpost continue running, but fail 210 * in the end. This should be used when we should stop building vmlinux 211 * or modules, but we can continue running modpost to catch as many 212 * issues as possible. 213 * 214 * fatal - show the given message, and bail out immediately. This should be 215 * used when there is no point to continue running modpost. 216 */ 217 #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args) 218 #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args) 219 #define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args) 220