Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 2 | /* This is included from relocs_32/64.c */ |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 3 | |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 4 | #define ElfW(type) _ElfW(ELF_BITS, type) |
| 5 | #define _ElfW(bits, type) __ElfW(bits, type) |
| 6 | #define __ElfW(bits, type) Elf##bits##_##type |
| 7 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 8 | #define Elf_Addr ElfW(Addr) |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 9 | #define Elf_Ehdr ElfW(Ehdr) |
| 10 | #define Elf_Phdr ElfW(Phdr) |
| 11 | #define Elf_Shdr ElfW(Shdr) |
| 12 | #define Elf_Sym ElfW(Sym) |
| 13 | |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 14 | static Elf_Ehdr ehdr; |
| 15 | static unsigned long shnum; |
| 16 | static unsigned int shstrndx; |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 17 | static unsigned int shsymtabndx; |
| 18 | static unsigned int shxsymtabndx; |
| 19 | |
| 20 | static int sym_index(Elf_Sym *sym); |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 21 | |
| 22 | struct relocs { |
| 23 | uint32_t *offset; |
| 24 | unsigned long count; |
| 25 | unsigned long size; |
| 26 | }; |
| 27 | |
| 28 | static struct relocs relocs16; |
| 29 | static struct relocs relocs32; |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 30 | #if ELF_BITS == 64 |
| 31 | static struct relocs relocs32neg; |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 32 | static struct relocs relocs64; |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 33 | #define FMT PRIu64 |
| 34 | #else |
| 35 | #define FMT PRIu32 |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 36 | #endif |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 37 | |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 38 | struct section { |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 39 | Elf_Shdr shdr; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 40 | struct section *link; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 41 | Elf_Sym *symtab; |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 42 | Elf32_Word *xsymtab; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 43 | Elf_Rel *reltab; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 44 | char *strtab; |
| 45 | }; |
| 46 | static struct section *secs; |
| 47 | |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 48 | static const char * const sym_regex_kernel[S_NSYMTYPES] = { |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 49 | /* |
| 50 | * Following symbols have been audited. There values are constant and do |
| 51 | * not change if bzImage is loaded at a different physical address than |
| 52 | * the address for which it has been compiled. Don't warn user about |
| 53 | * absolute relocations present w.r.t these symbols. |
| 54 | */ |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 55 | [S_ABS] = |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 56 | "^(xen_irq_disable_direct_reloc$|" |
| 57 | "xen_save_fl_direct_reloc$|" |
| 58 | "VDSO|" |
Sami Tolvanen | ca7e10b | 2022-09-08 14:55:01 -0700 | [diff] [blame] | 59 | "__kcfi_typeid_|" |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 60 | "__crc_)", |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 61 | |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 62 | /* |
| 63 | * These symbols are known to be relative, even if the linker marks them |
| 64 | * as absolute (typically defined outside any section in the linker script.) |
| 65 | */ |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 66 | [S_REL] = |
H. Peter Anvin | a3e854d | 2012-05-18 00:24:09 -0700 | [diff] [blame] | 67 | "^(__init_(begin|end)|" |
| 68 | "__x86_cpu_dev_(start|end)|" |
Juergen Gross | f7af697 | 2023-12-10 07:21:38 +0100 | [diff] [blame] | 69 | "__alt_instructions(_end)?|" |
H. Nikolaus Schaller | fa953ad | 2021-07-08 10:57:09 +0200 | [diff] [blame] | 70 | "(__iommu_table|__apicdrivers|__smp_locks)(_end)?|" |
H. Peter Anvin | fd95281 | 2012-05-23 14:02:34 -0700 | [diff] [blame] | 71 | "__(start|end)_pci_.*|" |
Lukas Bulwahn | d6f12f8 | 2021-12-29 12:15:53 +0100 | [diff] [blame] | 72 | #if CONFIG_FW_LOADER |
H. Peter Anvin | fd95281 | 2012-05-23 14:02:34 -0700 | [diff] [blame] | 73 | "__(start|end)_builtin_fw|" |
Luis Chamberlain | c8dcf65 | 2021-10-21 08:58:39 -0700 | [diff] [blame] | 74 | #endif |
H. Nikolaus Schaller | fa953ad | 2021-07-08 10:57:09 +0200 | [diff] [blame] | 75 | "__(start|stop)___ksymtab(_gpl)?|" |
| 76 | "__(start|stop)___kcrctab(_gpl)?|" |
H. Peter Anvin | fd95281 | 2012-05-23 14:02:34 -0700 | [diff] [blame] | 77 | "__(start|stop)___param|" |
| 78 | "__(start|stop)___modver|" |
| 79 | "__(start|stop)___bug_table|" |
| 80 | "__tracedata_(start|end)|" |
| 81 | "__(start|stop)_notes|" |
| 82 | "__end_rodata|" |
Joerg Roedel | a29dba1 | 2018-08-09 11:44:49 +0200 | [diff] [blame] | 83 | "__end_rodata_aligned|" |
H. Peter Anvin | fd95281 | 2012-05-23 14:02:34 -0700 | [diff] [blame] | 84 | "__initramfs_start|" |
H. Peter Anvin | ea17e74 | 2012-05-24 07:01:38 -0700 | [diff] [blame] | 85 | "(jiffies|jiffies_64)|" |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 86 | #if ELF_BITS == 64 |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 87 | "__per_cpu_load|" |
| 88 | "init_per_cpu__.*|" |
| 89 | "__end_rodata_hpage_align|" |
| 90 | #endif |
Stefani Seibold | d2312e3 | 2014-03-17 23:22:01 +0100 | [diff] [blame] | 91 | "__vvar_page|" |
H. Peter Anvin | a3e854d | 2012-05-18 00:24:09 -0700 | [diff] [blame] | 92 | "_end)$" |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 93 | }; |
| 94 | |
| 95 | |
| 96 | static const char * const sym_regex_realmode[S_NSYMTYPES] = { |
| 97 | /* |
H. Peter Anvin | 2a6de31 | 2012-05-08 21:22:31 +0300 | [diff] [blame] | 98 | * These symbols are known to be relative, even if the linker marks them |
| 99 | * as absolute (typically defined outside any section in the linker script.) |
| 100 | */ |
| 101 | [S_REL] = |
| 102 | "^pa_", |
| 103 | |
| 104 | /* |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 105 | * These are 16-bit segment symbols when compiling 16-bit code. |
| 106 | */ |
| 107 | [S_SEG] = |
| 108 | "^real_mode_seg$", |
| 109 | |
| 110 | /* |
| 111 | * These are offsets belonging to segments, as opposed to linear addresses, |
| 112 | * when compiling 16-bit code. |
| 113 | */ |
| 114 | [S_LIN] = |
| 115 | "^pa_", |
| 116 | }; |
| 117 | |
| 118 | static const char * const *sym_regex; |
| 119 | |
| 120 | static regex_t sym_regex_c[S_NSYMTYPES]; |
| 121 | static int is_reloc(enum symtype type, const char *sym_name) |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 122 | { |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 123 | return sym_regex[type] && |
| 124 | !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0); |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 125 | } |
| 126 | |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 127 | static void regex_init(int use_real_mode) |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 128 | { |
| 129 | char errbuf[128]; |
| 130 | int err; |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 131 | int i; |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 132 | |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 133 | if (use_real_mode) |
| 134 | sym_regex = sym_regex_realmode; |
| 135 | else |
| 136 | sym_regex = sym_regex_kernel; |
| 137 | |
| 138 | for (i = 0; i < S_NSYMTYPES; i++) { |
| 139 | if (!sym_regex[i]) |
| 140 | continue; |
| 141 | |
| 142 | err = regcomp(&sym_regex_c[i], sym_regex[i], |
| 143 | REG_EXTENDED|REG_NOSUB); |
| 144 | |
| 145 | if (err) { |
Jordan Borgner | 0e96f31 | 2018-10-28 12:58:28 +0000 | [diff] [blame] | 146 | regerror(err, &sym_regex_c[i], errbuf, sizeof(errbuf)); |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 147 | die("%s", errbuf); |
| 148 | } |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 149 | } |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 150 | } |
| 151 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 152 | static const char *sym_type(unsigned type) |
| 153 | { |
| 154 | static const char *type_name[] = { |
| 155 | #define SYM_TYPE(X) [X] = #X |
| 156 | SYM_TYPE(STT_NOTYPE), |
| 157 | SYM_TYPE(STT_OBJECT), |
| 158 | SYM_TYPE(STT_FUNC), |
| 159 | SYM_TYPE(STT_SECTION), |
| 160 | SYM_TYPE(STT_FILE), |
| 161 | SYM_TYPE(STT_COMMON), |
| 162 | SYM_TYPE(STT_TLS), |
| 163 | #undef SYM_TYPE |
| 164 | }; |
| 165 | const char *name = "unknown sym type name"; |
Robert P. J. Day | ca82018 | 2007-02-17 19:10:01 +0100 | [diff] [blame] | 166 | if (type < ARRAY_SIZE(type_name)) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 167 | name = type_name[type]; |
| 168 | } |
| 169 | return name; |
| 170 | } |
| 171 | |
| 172 | static const char *sym_bind(unsigned bind) |
| 173 | { |
| 174 | static const char *bind_name[] = { |
| 175 | #define SYM_BIND(X) [X] = #X |
| 176 | SYM_BIND(STB_LOCAL), |
| 177 | SYM_BIND(STB_GLOBAL), |
| 178 | SYM_BIND(STB_WEAK), |
| 179 | #undef SYM_BIND |
| 180 | }; |
| 181 | const char *name = "unknown sym bind name"; |
Robert P. J. Day | ca82018 | 2007-02-17 19:10:01 +0100 | [diff] [blame] | 182 | if (bind < ARRAY_SIZE(bind_name)) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 183 | name = bind_name[bind]; |
| 184 | } |
| 185 | return name; |
| 186 | } |
| 187 | |
| 188 | static const char *sym_visibility(unsigned visibility) |
| 189 | { |
| 190 | static const char *visibility_name[] = { |
| 191 | #define SYM_VISIBILITY(X) [X] = #X |
| 192 | SYM_VISIBILITY(STV_DEFAULT), |
| 193 | SYM_VISIBILITY(STV_INTERNAL), |
| 194 | SYM_VISIBILITY(STV_HIDDEN), |
| 195 | SYM_VISIBILITY(STV_PROTECTED), |
| 196 | #undef SYM_VISIBILITY |
| 197 | }; |
| 198 | const char *name = "unknown sym visibility name"; |
Robert P. J. Day | ca82018 | 2007-02-17 19:10:01 +0100 | [diff] [blame] | 199 | if (visibility < ARRAY_SIZE(visibility_name)) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 200 | name = visibility_name[visibility]; |
| 201 | } |
| 202 | return name; |
| 203 | } |
| 204 | |
| 205 | static const char *rel_type(unsigned type) |
| 206 | { |
| 207 | static const char *type_name[] = { |
| 208 | #define REL_TYPE(X) [X] = #X |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 209 | #if ELF_BITS == 64 |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 210 | REL_TYPE(R_X86_64_NONE), |
| 211 | REL_TYPE(R_X86_64_64), |
Ard Biesheuvel | b40a142 | 2018-09-18 23:51:39 -0700 | [diff] [blame] | 212 | REL_TYPE(R_X86_64_PC64), |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 213 | REL_TYPE(R_X86_64_PC32), |
| 214 | REL_TYPE(R_X86_64_GOT32), |
| 215 | REL_TYPE(R_X86_64_PLT32), |
| 216 | REL_TYPE(R_X86_64_COPY), |
| 217 | REL_TYPE(R_X86_64_GLOB_DAT), |
| 218 | REL_TYPE(R_X86_64_JUMP_SLOT), |
| 219 | REL_TYPE(R_X86_64_RELATIVE), |
| 220 | REL_TYPE(R_X86_64_GOTPCREL), |
| 221 | REL_TYPE(R_X86_64_32), |
| 222 | REL_TYPE(R_X86_64_32S), |
| 223 | REL_TYPE(R_X86_64_16), |
| 224 | REL_TYPE(R_X86_64_PC16), |
| 225 | REL_TYPE(R_X86_64_8), |
| 226 | REL_TYPE(R_X86_64_PC8), |
| 227 | #else |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 228 | REL_TYPE(R_386_NONE), |
| 229 | REL_TYPE(R_386_32), |
| 230 | REL_TYPE(R_386_PC32), |
| 231 | REL_TYPE(R_386_GOT32), |
| 232 | REL_TYPE(R_386_PLT32), |
| 233 | REL_TYPE(R_386_COPY), |
| 234 | REL_TYPE(R_386_GLOB_DAT), |
| 235 | REL_TYPE(R_386_JMP_SLOT), |
| 236 | REL_TYPE(R_386_RELATIVE), |
| 237 | REL_TYPE(R_386_GOTOFF), |
| 238 | REL_TYPE(R_386_GOTPC), |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 239 | REL_TYPE(R_386_8), |
| 240 | REL_TYPE(R_386_PC8), |
| 241 | REL_TYPE(R_386_16), |
| 242 | REL_TYPE(R_386_PC16), |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 243 | #endif |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 244 | #undef REL_TYPE |
| 245 | }; |
| 246 | const char *name = "unknown type rel type name"; |
H. Peter Anvin | 873b527 | 2009-12-14 13:55:20 -0800 | [diff] [blame] | 247 | if (type < ARRAY_SIZE(type_name) && type_name[type]) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 248 | name = type_name[type]; |
| 249 | } |
| 250 | return name; |
| 251 | } |
| 252 | |
| 253 | static const char *sec_name(unsigned shndx) |
| 254 | { |
| 255 | const char *sec_strtab; |
| 256 | const char *name; |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 257 | sec_strtab = secs[shstrndx].strtab; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 258 | name = "<noname>"; |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 259 | if (shndx < shnum) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 260 | name = sec_strtab + secs[shndx].shdr.sh_name; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 261 | } |
| 262 | else if (shndx == SHN_ABS) { |
| 263 | name = "ABSOLUTE"; |
| 264 | } |
| 265 | else if (shndx == SHN_COMMON) { |
| 266 | name = "COMMON"; |
| 267 | } |
| 268 | return name; |
| 269 | } |
| 270 | |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 271 | static const char *sym_name(const char *sym_strtab, Elf_Sym *sym) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 272 | { |
| 273 | const char *name; |
| 274 | name = "<noname>"; |
| 275 | if (sym->st_name) { |
| 276 | name = sym_strtab + sym->st_name; |
| 277 | } |
| 278 | else { |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 279 | name = sec_name(sym_index(sym)); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 280 | } |
| 281 | return name; |
| 282 | } |
| 283 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 284 | static Elf_Sym *sym_lookup(const char *symname) |
| 285 | { |
| 286 | int i; |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 287 | for (i = 0; i < shnum; i++) { |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 288 | struct section *sec = &secs[i]; |
| 289 | long nsyms; |
| 290 | char *strtab; |
| 291 | Elf_Sym *symtab; |
| 292 | Elf_Sym *sym; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 293 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 294 | if (sec->shdr.sh_type != SHT_SYMTAB) |
| 295 | continue; |
| 296 | |
| 297 | nsyms = sec->shdr.sh_size/sizeof(Elf_Sym); |
| 298 | symtab = sec->symtab; |
| 299 | strtab = sec->link->strtab; |
| 300 | |
| 301 | for (sym = symtab; --nsyms >= 0; sym++) { |
| 302 | if (!sym->st_name) |
| 303 | continue; |
| 304 | if (strcmp(symname, strtab + sym->st_name) == 0) |
| 305 | return sym; |
| 306 | } |
| 307 | } |
| 308 | return 0; |
| 309 | } |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 310 | |
Linus Torvalds | 13da9e2 | 2010-05-26 08:30:15 -0700 | [diff] [blame] | 311 | #if BYTE_ORDER == LITTLE_ENDIAN |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 312 | #define le16_to_cpu(val) (val) |
| 313 | #define le32_to_cpu(val) (val) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 314 | #define le64_to_cpu(val) (val) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 315 | #endif |
Linus Torvalds | 13da9e2 | 2010-05-26 08:30:15 -0700 | [diff] [blame] | 316 | #if BYTE_ORDER == BIG_ENDIAN |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 317 | #define le16_to_cpu(val) bswap_16(val) |
| 318 | #define le32_to_cpu(val) bswap_32(val) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 319 | #define le64_to_cpu(val) bswap_64(val) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 320 | #endif |
| 321 | |
| 322 | static uint16_t elf16_to_cpu(uint16_t val) |
| 323 | { |
| 324 | return le16_to_cpu(val); |
| 325 | } |
| 326 | |
| 327 | static uint32_t elf32_to_cpu(uint32_t val) |
| 328 | { |
| 329 | return le32_to_cpu(val); |
| 330 | } |
| 331 | |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 332 | #define elf_half_to_cpu(x) elf16_to_cpu(x) |
| 333 | #define elf_word_to_cpu(x) elf32_to_cpu(x) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 334 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 335 | #if ELF_BITS == 64 |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 336 | static uint64_t elf64_to_cpu(uint64_t val) |
| 337 | { |
| 338 | return le64_to_cpu(val); |
| 339 | } |
| 340 | #define elf_addr_to_cpu(x) elf64_to_cpu(x) |
| 341 | #define elf_off_to_cpu(x) elf64_to_cpu(x) |
| 342 | #define elf_xword_to_cpu(x) elf64_to_cpu(x) |
| 343 | #else |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 344 | #define elf_addr_to_cpu(x) elf32_to_cpu(x) |
| 345 | #define elf_off_to_cpu(x) elf32_to_cpu(x) |
| 346 | #define elf_xword_to_cpu(x) elf32_to_cpu(x) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 347 | #endif |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 348 | |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 349 | static int sym_index(Elf_Sym *sym) |
| 350 | { |
| 351 | Elf_Sym *symtab = secs[shsymtabndx].symtab; |
| 352 | Elf32_Word *xsymtab = secs[shxsymtabndx].xsymtab; |
| 353 | unsigned long offset; |
| 354 | int index; |
| 355 | |
| 356 | if (sym->st_shndx != SHN_XINDEX) |
| 357 | return sym->st_shndx; |
| 358 | |
| 359 | /* calculate offset of sym from head of table. */ |
| 360 | offset = (unsigned long)sym - (unsigned long)symtab; |
| 361 | index = offset / sizeof(*sym); |
| 362 | |
| 363 | return elf32_to_cpu(xsymtab[index]); |
| 364 | } |
| 365 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 366 | static void read_ehdr(FILE *fp) |
| 367 | { |
| 368 | if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) { |
| 369 | die("Cannot read ELF header: %s\n", |
| 370 | strerror(errno)); |
| 371 | } |
Cyrill Gorcunov | 8bd1796 | 2008-05-03 14:18:03 +0400 | [diff] [blame] | 372 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 373 | die("No ELF magic\n"); |
| 374 | } |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 375 | if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) { |
| 376 | die("Not a %d bit executable\n", ELF_BITS); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 377 | } |
| 378 | if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) { |
| 379 | die("Not a LSB ELF executable\n"); |
| 380 | } |
| 381 | if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) { |
| 382 | die("Unknown ELF version\n"); |
| 383 | } |
| 384 | /* Convert the fields to native endian */ |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 385 | ehdr.e_type = elf_half_to_cpu(ehdr.e_type); |
| 386 | ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine); |
| 387 | ehdr.e_version = elf_word_to_cpu(ehdr.e_version); |
| 388 | ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry); |
| 389 | ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff); |
| 390 | ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff); |
| 391 | ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags); |
| 392 | ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize); |
| 393 | ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize); |
| 394 | ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum); |
| 395 | ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize); |
| 396 | ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum); |
| 397 | ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 398 | |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 399 | shnum = ehdr.e_shnum; |
| 400 | shstrndx = ehdr.e_shstrndx; |
| 401 | |
| 402 | if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 403 | die("Unsupported ELF header type\n"); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 404 | if (ehdr.e_machine != ELF_MACHINE) |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 405 | die("Not for %s\n", ELF_MACHINE_NAME); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 406 | if (ehdr.e_version != EV_CURRENT) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 407 | die("Unknown ELF version\n"); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 408 | if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) |
Alexey Dobriyan | 70e7986 | 2023-02-28 15:14:17 +0300 | [diff] [blame] | 409 | die("Bad ELF header size\n"); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 410 | if (ehdr.e_phentsize != sizeof(Elf_Phdr)) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 411 | die("Bad program header entry\n"); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 412 | if (ehdr.e_shentsize != sizeof(Elf_Shdr)) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 413 | die("Bad section header entry\n"); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 414 | |
| 415 | |
| 416 | if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) { |
| 417 | Elf_Shdr shdr; |
| 418 | |
| 419 | if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 420 | die("Seek to %" FMT " failed: %s\n", ehdr.e_shoff, strerror(errno)); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 421 | |
| 422 | if (fread(&shdr, sizeof(shdr), 1, fp) != 1) |
| 423 | die("Cannot read initial ELF section header: %s\n", strerror(errno)); |
| 424 | |
| 425 | if (shnum == SHN_UNDEF) |
| 426 | shnum = elf_xword_to_cpu(shdr.sh_size); |
| 427 | |
| 428 | if (shstrndx == SHN_XINDEX) |
| 429 | shstrndx = elf_word_to_cpu(shdr.sh_link); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 430 | } |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 431 | |
| 432 | if (shstrndx >= shnum) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 433 | die("String table index out of bounds\n"); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 434 | } |
| 435 | |
| 436 | static void read_shdrs(FILE *fp) |
| 437 | { |
| 438 | int i; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 439 | Elf_Shdr shdr; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 440 | |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 441 | secs = calloc(shnum, sizeof(struct section)); |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 442 | if (!secs) { |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 443 | die("Unable to allocate %ld section headers\n", |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 444 | shnum); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 445 | } |
| 446 | if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) { |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 447 | die("Seek to %" FMT " failed: %s\n", |
| 448 | ehdr.e_shoff, strerror(errno)); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 449 | } |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 450 | for (i = 0; i < shnum; i++) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 451 | struct section *sec = &secs[i]; |
Jordan Borgner | 0e96f31 | 2018-10-28 12:58:28 +0000 | [diff] [blame] | 452 | if (fread(&shdr, sizeof(shdr), 1, fp) != 1) |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 453 | die("Cannot read ELF section headers %d/%ld: %s\n", |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 454 | i, shnum, strerror(errno)); |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 455 | sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name); |
| 456 | sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type); |
| 457 | sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags); |
| 458 | sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr); |
| 459 | sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset); |
| 460 | sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size); |
| 461 | sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link); |
| 462 | sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info); |
| 463 | sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign); |
| 464 | sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 465 | if (sec->shdr.sh_link < shnum) |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 466 | sec->link = &secs[sec->shdr.sh_link]; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 467 | } |
| 468 | |
| 469 | } |
| 470 | |
| 471 | static void read_strtabs(FILE *fp) |
| 472 | { |
| 473 | int i; |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 474 | for (i = 0; i < shnum; i++) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 475 | struct section *sec = &secs[i]; |
| 476 | if (sec->shdr.sh_type != SHT_STRTAB) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 477 | continue; |
| 478 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 479 | sec->strtab = malloc(sec->shdr.sh_size); |
| 480 | if (!sec->strtab) { |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 481 | die("malloc of %" FMT " bytes for strtab failed\n", |
| 482 | sec->shdr.sh_size); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 483 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 484 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 485 | die("Seek to %" FMT " failed: %s\n", |
| 486 | sec->shdr.sh_offset, strerror(errno)); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 487 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 488 | if (fread(sec->strtab, 1, sec->shdr.sh_size, fp) |
| 489 | != sec->shdr.sh_size) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 490 | die("Cannot read symbol table: %s\n", |
| 491 | strerror(errno)); |
| 492 | } |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | static void read_symtabs(FILE *fp) |
| 497 | { |
| 498 | int i,j; |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 499 | |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 500 | for (i = 0; i < shnum; i++) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 501 | struct section *sec = &secs[i]; |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 502 | int num_syms; |
| 503 | |
| 504 | switch (sec->shdr.sh_type) { |
| 505 | case SHT_SYMTAB_SHNDX: |
| 506 | sec->xsymtab = malloc(sec->shdr.sh_size); |
| 507 | if (!sec->xsymtab) { |
| 508 | die("malloc of %" FMT " bytes for xsymtab failed\n", |
| 509 | sec->shdr.sh_size); |
| 510 | } |
| 511 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
| 512 | die("Seek to %" FMT " failed: %s\n", |
| 513 | sec->shdr.sh_offset, strerror(errno)); |
| 514 | } |
| 515 | if (fread(sec->xsymtab, 1, sec->shdr.sh_size, fp) |
| 516 | != sec->shdr.sh_size) { |
| 517 | die("Cannot read extended symbol table: %s\n", |
| 518 | strerror(errno)); |
| 519 | } |
| 520 | shxsymtabndx = i; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 521 | continue; |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 522 | |
| 523 | case SHT_SYMTAB: |
| 524 | num_syms = sec->shdr.sh_size / sizeof(Elf_Sym); |
| 525 | |
| 526 | sec->symtab = malloc(sec->shdr.sh_size); |
| 527 | if (!sec->symtab) { |
| 528 | die("malloc of %" FMT " bytes for symtab failed\n", |
| 529 | sec->shdr.sh_size); |
| 530 | } |
| 531 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
| 532 | die("Seek to %" FMT " failed: %s\n", |
| 533 | sec->shdr.sh_offset, strerror(errno)); |
| 534 | } |
| 535 | if (fread(sec->symtab, 1, sec->shdr.sh_size, fp) |
| 536 | != sec->shdr.sh_size) { |
| 537 | die("Cannot read symbol table: %s\n", |
| 538 | strerror(errno)); |
| 539 | } |
| 540 | for (j = 0; j < num_syms; j++) { |
| 541 | Elf_Sym *sym = &sec->symtab[j]; |
| 542 | |
| 543 | sym->st_name = elf_word_to_cpu(sym->st_name); |
| 544 | sym->st_value = elf_addr_to_cpu(sym->st_value); |
| 545 | sym->st_size = elf_xword_to_cpu(sym->st_size); |
| 546 | sym->st_shndx = elf_half_to_cpu(sym->st_shndx); |
| 547 | } |
| 548 | shsymtabndx = i; |
| 549 | continue; |
| 550 | |
| 551 | default: |
| 552 | continue; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 553 | } |
| 554 | } |
| 555 | } |
| 556 | |
| 557 | |
| 558 | static void read_relocs(FILE *fp) |
| 559 | { |
| 560 | int i,j; |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 561 | for (i = 0; i < shnum; i++) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 562 | struct section *sec = &secs[i]; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 563 | if (sec->shdr.sh_type != SHT_REL_TYPE) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 564 | continue; |
| 565 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 566 | sec->reltab = malloc(sec->shdr.sh_size); |
| 567 | if (!sec->reltab) { |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 568 | die("malloc of %" FMT " bytes for relocs failed\n", |
| 569 | sec->shdr.sh_size); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 570 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 571 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
Borislav Petkov | 03dca99 | 2021-06-25 17:10:16 +0200 | [diff] [blame] | 572 | die("Seek to %" FMT " failed: %s\n", |
| 573 | sec->shdr.sh_offset, strerror(errno)); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 574 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 575 | if (fread(sec->reltab, 1, sec->shdr.sh_size, fp) |
| 576 | != sec->shdr.sh_size) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 577 | die("Cannot read symbol table: %s\n", |
| 578 | strerror(errno)); |
| 579 | } |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 580 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
| 581 | Elf_Rel *rel = &sec->reltab[j]; |
| 582 | rel->r_offset = elf_addr_to_cpu(rel->r_offset); |
| 583 | rel->r_info = elf_xword_to_cpu(rel->r_info); |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 584 | #if (SHT_REL_TYPE == SHT_RELA) |
| 585 | rel->r_addend = elf_xword_to_cpu(rel->r_addend); |
| 586 | #endif |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 587 | } |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | |
| 592 | static void print_absolute_symbols(void) |
| 593 | { |
| 594 | int i; |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 595 | const char *format; |
| 596 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 597 | if (ELF_BITS == 64) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 598 | format = "%5d %016"PRIx64" %5"PRId64" %10s %10s %12s %s\n"; |
| 599 | else |
| 600 | format = "%5d %08"PRIx32" %5"PRId32" %10s %10s %12s %s\n"; |
| 601 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 602 | printf("Absolute symbols\n"); |
| 603 | printf(" Num: Value Size Type Bind Visibility Name\n"); |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 604 | for (i = 0; i < shnum; i++) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 605 | struct section *sec = &secs[i]; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 606 | char *sym_strtab; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 607 | int j; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 608 | |
| 609 | if (sec->shdr.sh_type != SHT_SYMTAB) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 610 | continue; |
| 611 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 612 | sym_strtab = sec->link->strtab; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 613 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) { |
| 614 | Elf_Sym *sym; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 615 | const char *name; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 616 | sym = &sec->symtab[j]; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 617 | name = sym_name(sym_strtab, sym); |
| 618 | if (sym->st_shndx != SHN_ABS) { |
| 619 | continue; |
| 620 | } |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 621 | printf(format, |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 622 | j, sym->st_value, sym->st_size, |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 623 | sym_type(ELF_ST_TYPE(sym->st_info)), |
| 624 | sym_bind(ELF_ST_BIND(sym->st_info)), |
| 625 | sym_visibility(ELF_ST_VISIBILITY(sym->st_other)), |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 626 | name); |
| 627 | } |
| 628 | } |
| 629 | printf("\n"); |
| 630 | } |
| 631 | |
| 632 | static void print_absolute_relocs(void) |
| 633 | { |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 634 | int i, printed = 0; |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 635 | const char *format; |
| 636 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 637 | if (ELF_BITS == 64) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 638 | format = "%016"PRIx64" %016"PRIx64" %10s %016"PRIx64" %s\n"; |
| 639 | else |
| 640 | format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32" %s\n"; |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 641 | |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 642 | for (i = 0; i < shnum; i++) { |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 643 | struct section *sec = &secs[i]; |
| 644 | struct section *sec_applies, *sec_symtab; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 645 | char *sym_strtab; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 646 | Elf_Sym *sh_symtab; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 647 | int j; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 648 | if (sec->shdr.sh_type != SHT_REL_TYPE) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 649 | continue; |
| 650 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 651 | sec_symtab = sec->link; |
| 652 | sec_applies = &secs[sec->shdr.sh_info]; |
| 653 | if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 654 | continue; |
| 655 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 656 | sh_symtab = sec_symtab->symtab; |
| 657 | sym_strtab = sec_symtab->link->strtab; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 658 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
| 659 | Elf_Rel *rel; |
| 660 | Elf_Sym *sym; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 661 | const char *name; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 662 | rel = &sec->reltab[j]; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 663 | sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 664 | name = sym_name(sym_strtab, sym); |
| 665 | if (sym->st_shndx != SHN_ABS) { |
| 666 | continue; |
| 667 | } |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 668 | |
| 669 | /* Absolute symbols are not relocated if bzImage is |
| 670 | * loaded at a non-compiled address. Display a warning |
| 671 | * to user at compile time about the absolute |
| 672 | * relocations present. |
| 673 | * |
| 674 | * User need to audit the code to make sure |
| 675 | * some symbols which should have been section |
| 676 | * relative have not become absolute because of some |
| 677 | * linker optimization or wrong programming usage. |
| 678 | * |
| 679 | * Before warning check if this absolute symbol |
| 680 | * relocation is harmless. |
| 681 | */ |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 682 | if (is_reloc(S_ABS, name) || is_reloc(S_REL, name)) |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 683 | continue; |
| 684 | |
| 685 | if (!printed) { |
| 686 | printf("WARNING: Absolute relocations" |
| 687 | " present\n"); |
| 688 | printf("Offset Info Type Sym.Value " |
| 689 | "Sym.Name\n"); |
| 690 | printed = 1; |
| 691 | } |
| 692 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 693 | printf(format, |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 694 | rel->r_offset, |
| 695 | rel->r_info, |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 696 | rel_type(ELF_R_TYPE(rel->r_info)), |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 697 | sym->st_value, |
| 698 | name); |
| 699 | } |
| 700 | } |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 701 | |
| 702 | if (printed) |
| 703 | printf("\n"); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 704 | } |
| 705 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 706 | static void add_reloc(struct relocs *r, uint32_t offset) |
| 707 | { |
| 708 | if (r->count == r->size) { |
| 709 | unsigned long newsize = r->size + 50000; |
| 710 | void *mem = realloc(r->offset, newsize * sizeof(r->offset[0])); |
| 711 | |
| 712 | if (!mem) |
| 713 | die("realloc of %ld entries for relocs failed\n", |
| 714 | newsize); |
| 715 | r->offset = mem; |
| 716 | r->size = newsize; |
| 717 | } |
| 718 | r->offset[r->count++] = offset; |
| 719 | } |
| 720 | |
| 721 | static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, |
| 722 | Elf_Sym *sym, const char *symname)) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 723 | { |
| 724 | int i; |
| 725 | /* Walk through the relocations */ |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 726 | for (i = 0; i < shnum; i++) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 727 | char *sym_strtab; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 728 | Elf_Sym *sh_symtab; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 729 | struct section *sec_applies, *sec_symtab; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 730 | int j; |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 731 | struct section *sec = &secs[i]; |
| 732 | |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 733 | if (sec->shdr.sh_type != SHT_REL_TYPE) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 734 | continue; |
| 735 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 736 | sec_symtab = sec->link; |
| 737 | sec_applies = &secs[sec->shdr.sh_info]; |
| 738 | if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 739 | continue; |
| 740 | } |
H. Peter Anvin | 908ec7a | 2008-06-30 14:42:18 -0700 | [diff] [blame] | 741 | sh_symtab = sec_symtab->symtab; |
H. Peter Anvin | cc65f1e | 2008-10-03 13:00:56 -0700 | [diff] [blame] | 742 | sym_strtab = sec_symtab->link->strtab; |
Kees Cook | bf11655 | 2013-04-12 13:13:42 -0700 | [diff] [blame] | 743 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 744 | Elf_Rel *rel = &sec->reltab[j]; |
| 745 | Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; |
| 746 | const char *symname = sym_name(sym_strtab, sym); |
H. Peter Anvin | 24ab82b | 2012-05-18 09:52:01 -0700 | [diff] [blame] | 747 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 748 | process(sec, rel, sym, symname); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 749 | } |
| 750 | } |
| 751 | } |
| 752 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 753 | /* |
| 754 | * The .data..percpu section is a special case for x86_64 SMP kernels. |
| 755 | * It is used to initialize the actual per_cpu areas and to provide |
| 756 | * definitions for the per_cpu variables that correspond to their offsets |
| 757 | * within the percpu area. Since the values of all of the symbols need |
| 758 | * to be offsets from the start of the per_cpu area the virtual address |
| 759 | * (sh_addr) of .data..percpu is 0 in SMP kernels. |
| 760 | * |
| 761 | * This means that: |
| 762 | * |
| 763 | * Relocations that reference symbols in the per_cpu area do not |
| 764 | * need further relocation (since the value is an offset relative |
| 765 | * to the start of the per_cpu area that does not change). |
| 766 | * |
| 767 | * Relocations that apply to the per_cpu area need to have their |
| 768 | * offset adjusted by by the value of __per_cpu_load to make them |
| 769 | * point to the correct place in the loaded image (because the |
| 770 | * virtual address of .data..percpu is 0). |
| 771 | * |
| 772 | * For non SMP kernels .data..percpu is linked as part of the normal |
| 773 | * kernel data and does not require special treatment. |
| 774 | * |
| 775 | */ |
| 776 | static int per_cpu_shndx = -1; |
Ben Hutchings | eeeda4cd | 2014-09-24 13:30:12 +0100 | [diff] [blame] | 777 | static Elf_Addr per_cpu_load_addr; |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 778 | |
| 779 | static void percpu_init(void) |
| 780 | { |
| 781 | int i; |
Artem Savkov | f36e749 | 2018-11-29 16:56:15 +0100 | [diff] [blame] | 782 | for (i = 0; i < shnum; i++) { |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 783 | ElfW(Sym) *sym; |
| 784 | if (strcmp(sec_name(i), ".data..percpu")) |
| 785 | continue; |
| 786 | |
| 787 | if (secs[i].shdr.sh_addr != 0) /* non SMP kernel */ |
| 788 | return; |
| 789 | |
| 790 | sym = sym_lookup("__per_cpu_load"); |
| 791 | if (!sym) |
| 792 | die("can't find __per_cpu_load\n"); |
| 793 | |
| 794 | per_cpu_shndx = i; |
| 795 | per_cpu_load_addr = sym->st_value; |
| 796 | return; |
| 797 | } |
| 798 | } |
| 799 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 800 | #if ELF_BITS == 64 |
| 801 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 802 | /* |
| 803 | * Check to see if a symbol lies in the .data..percpu section. |
Michael Davidson | d751c16 | 2013-10-10 18:39:54 -0700 | [diff] [blame] | 804 | * |
| 805 | * The linker incorrectly associates some symbols with the |
| 806 | * .data..percpu section so we also need to check the symbol |
| 807 | * name to make sure that we classify the symbol correctly. |
| 808 | * |
| 809 | * The GNU linker incorrectly associates: |
| 810 | * __init_begin |
Kees Cook | aec58ba | 2013-10-15 23:43:14 -0700 | [diff] [blame] | 811 | * __per_cpu_load |
Michael Davidson | d751c16 | 2013-10-10 18:39:54 -0700 | [diff] [blame] | 812 | * |
| 813 | * The "gold" linker incorrectly associates: |
Andy Lutomirski | e6401c1 | 2019-04-14 18:00:06 +0200 | [diff] [blame] | 814 | * init_per_cpu__fixed_percpu_data |
Michael Davidson | d751c16 | 2013-10-10 18:39:54 -0700 | [diff] [blame] | 815 | * init_per_cpu__gdt_page |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 816 | */ |
| 817 | static int is_percpu_sym(ElfW(Sym) *sym, const char *symname) |
| 818 | { |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 819 | int shndx = sym_index(sym); |
| 820 | |
| 821 | return (shndx == per_cpu_shndx) && |
Michael Davidson | d751c16 | 2013-10-10 18:39:54 -0700 | [diff] [blame] | 822 | strcmp(symname, "__init_begin") && |
Kees Cook | aec58ba | 2013-10-15 23:43:14 -0700 | [diff] [blame] | 823 | strcmp(symname, "__per_cpu_load") && |
Michael Davidson | d751c16 | 2013-10-10 18:39:54 -0700 | [diff] [blame] | 824 | strncmp(symname, "init_per_cpu_", 13); |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 825 | } |
| 826 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 827 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 828 | static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, |
| 829 | const char *symname) |
| 830 | { |
| 831 | unsigned r_type = ELF64_R_TYPE(rel->r_info); |
| 832 | ElfW(Addr) offset = rel->r_offset; |
| 833 | int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); |
| 834 | |
| 835 | if (sym->st_shndx == SHN_UNDEF) |
| 836 | return 0; |
| 837 | |
| 838 | /* |
| 839 | * Adjust the offset if this reloc applies to the percpu section. |
| 840 | */ |
| 841 | if (sec->shdr.sh_info == per_cpu_shndx) |
| 842 | offset += per_cpu_load_addr; |
| 843 | |
| 844 | switch (r_type) { |
| 845 | case R_X86_64_NONE: |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 846 | /* NONE can be ignored. */ |
| 847 | break; |
| 848 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 849 | case R_X86_64_PC32: |
H.J. Lu | b21ebf2f | 2018-02-07 14:20:09 -0800 | [diff] [blame] | 850 | case R_X86_64_PLT32: |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 851 | /* |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 852 | * PC relative relocations don't need to be adjusted unless |
| 853 | * referencing a percpu symbol. |
H.J. Lu | b21ebf2f | 2018-02-07 14:20:09 -0800 | [diff] [blame] | 854 | * |
| 855 | * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32. |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 856 | */ |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 857 | if (is_percpu_sym(sym, symname)) |
| 858 | add_reloc(&relocs32neg, offset); |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 859 | break; |
| 860 | |
Ard Biesheuvel | b40a142 | 2018-09-18 23:51:39 -0700 | [diff] [blame] | 861 | case R_X86_64_PC64: |
| 862 | /* |
| 863 | * Only used by jump labels |
| 864 | */ |
| 865 | if (is_percpu_sym(sym, symname)) |
| 866 | die("Invalid R_X86_64_PC64 relocation against per-CPU symbol %s\n", |
| 867 | symname); |
| 868 | break; |
| 869 | |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 870 | case R_X86_64_32: |
| 871 | case R_X86_64_32S: |
| 872 | case R_X86_64_64: |
| 873 | /* |
| 874 | * References to the percpu area don't need to be adjusted. |
| 875 | */ |
| 876 | if (is_percpu_sym(sym, symname)) |
| 877 | break; |
| 878 | |
| 879 | if (shn_abs) { |
| 880 | /* |
| 881 | * Whitelisted absolute symbols do not require |
| 882 | * relocation. |
| 883 | */ |
| 884 | if (is_reloc(S_ABS, symname)) |
| 885 | break; |
| 886 | |
| 887 | die("Invalid absolute %s relocation: %s\n", |
| 888 | rel_type(r_type), symname); |
| 889 | break; |
| 890 | } |
| 891 | |
| 892 | /* |
| 893 | * Relocation offsets for 64 bit kernels are output |
| 894 | * as 32 bits and sign extended back to 64 bits when |
| 895 | * the relocations are processed. |
| 896 | * Make sure that the offset will fit. |
| 897 | */ |
| 898 | if ((int32_t)offset != (int64_t)offset) |
| 899 | die("Relocation offset doesn't fit in 32 bits\n"); |
| 900 | |
| 901 | if (r_type == R_X86_64_64) |
| 902 | add_reloc(&relocs64, offset); |
| 903 | else |
| 904 | add_reloc(&relocs32, offset); |
| 905 | break; |
| 906 | |
| 907 | default: |
| 908 | die("Unsupported relocation type: %s (%d)\n", |
| 909 | rel_type(r_type), r_type); |
| 910 | break; |
| 911 | } |
| 912 | |
| 913 | return 0; |
| 914 | } |
| 915 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 916 | #else |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 917 | |
| 918 | static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
| 919 | const char *symname) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 920 | { |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 921 | unsigned r_type = ELF32_R_TYPE(rel->r_info); |
| 922 | int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); |
| 923 | |
| 924 | switch (r_type) { |
| 925 | case R_386_NONE: |
| 926 | case R_386_PC32: |
| 927 | case R_386_PC16: |
| 928 | case R_386_PC8: |
Fangrui Song | bb73d07 | 2021-01-27 12:56:00 -0800 | [diff] [blame] | 929 | case R_386_PLT32: |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 930 | /* |
Fangrui Song | bb73d07 | 2021-01-27 12:56:00 -0800 | [diff] [blame] | 931 | * NONE can be ignored and PC relative relocations don't need |
| 932 | * to be adjusted. Because sym must be defined, R_386_PLT32 can |
| 933 | * be treated the same way as R_386_PC32. |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 934 | */ |
| 935 | break; |
| 936 | |
| 937 | case R_386_32: |
| 938 | if (shn_abs) { |
| 939 | /* |
| 940 | * Whitelisted absolute symbols do not require |
| 941 | * relocation. |
| 942 | */ |
| 943 | if (is_reloc(S_ABS, symname)) |
| 944 | break; |
| 945 | |
| 946 | die("Invalid absolute %s relocation: %s\n", |
| 947 | rel_type(r_type), symname); |
| 948 | break; |
| 949 | } |
| 950 | |
| 951 | add_reloc(&relocs32, rel->r_offset); |
| 952 | break; |
| 953 | |
| 954 | default: |
| 955 | die("Unsupported relocation type: %s (%d)\n", |
| 956 | rel_type(r_type), r_type); |
| 957 | break; |
| 958 | } |
| 959 | |
| 960 | return 0; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 961 | } |
| 962 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 963 | static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
| 964 | const char *symname) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 965 | { |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 966 | unsigned r_type = ELF32_R_TYPE(rel->r_info); |
| 967 | int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); |
| 968 | |
| 969 | switch (r_type) { |
| 970 | case R_386_NONE: |
| 971 | case R_386_PC32: |
| 972 | case R_386_PC16: |
| 973 | case R_386_PC8: |
Fangrui Song | bb73d07 | 2021-01-27 12:56:00 -0800 | [diff] [blame] | 974 | case R_386_PLT32: |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 975 | /* |
Fangrui Song | bb73d07 | 2021-01-27 12:56:00 -0800 | [diff] [blame] | 976 | * NONE can be ignored and PC relative relocations don't need |
| 977 | * to be adjusted. Because sym must be defined, R_386_PLT32 can |
| 978 | * be treated the same way as R_386_PC32. |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 979 | */ |
| 980 | break; |
| 981 | |
| 982 | case R_386_16: |
| 983 | if (shn_abs) { |
| 984 | /* |
| 985 | * Whitelisted absolute symbols do not require |
| 986 | * relocation. |
| 987 | */ |
| 988 | if (is_reloc(S_ABS, symname)) |
| 989 | break; |
| 990 | |
| 991 | if (is_reloc(S_SEG, symname)) { |
| 992 | add_reloc(&relocs16, rel->r_offset); |
| 993 | break; |
| 994 | } |
| 995 | } else { |
| 996 | if (!is_reloc(S_LIN, symname)) |
| 997 | break; |
| 998 | } |
| 999 | die("Invalid %s %s relocation: %s\n", |
| 1000 | shn_abs ? "absolute" : "relative", |
| 1001 | rel_type(r_type), symname); |
| 1002 | break; |
| 1003 | |
| 1004 | case R_386_32: |
| 1005 | if (shn_abs) { |
| 1006 | /* |
| 1007 | * Whitelisted absolute symbols do not require |
| 1008 | * relocation. |
| 1009 | */ |
| 1010 | if (is_reloc(S_ABS, symname)) |
| 1011 | break; |
| 1012 | |
| 1013 | if (is_reloc(S_REL, symname)) { |
| 1014 | add_reloc(&relocs32, rel->r_offset); |
| 1015 | break; |
| 1016 | } |
| 1017 | } else { |
| 1018 | if (is_reloc(S_LIN, symname)) |
| 1019 | add_reloc(&relocs32, rel->r_offset); |
| 1020 | break; |
| 1021 | } |
| 1022 | die("Invalid %s %s relocation: %s\n", |
| 1023 | shn_abs ? "absolute" : "relative", |
| 1024 | rel_type(r_type), symname); |
| 1025 | break; |
| 1026 | |
| 1027 | default: |
| 1028 | die("Unsupported relocation type: %s (%d)\n", |
| 1029 | rel_type(r_type), r_type); |
| 1030 | break; |
| 1031 | } |
| 1032 | |
| 1033 | return 0; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1034 | } |
| 1035 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1036 | #endif |
| 1037 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1038 | static int cmp_relocs(const void *va, const void *vb) |
| 1039 | { |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1040 | const uint32_t *a, *b; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1041 | a = va; b = vb; |
| 1042 | return (*a == *b)? 0 : (*a > *b)? 1 : -1; |
| 1043 | } |
| 1044 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1045 | static void sort_relocs(struct relocs *r) |
| 1046 | { |
| 1047 | qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); |
| 1048 | } |
| 1049 | |
| 1050 | static int write32(uint32_t v, FILE *f) |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1051 | { |
| 1052 | unsigned char buf[4]; |
| 1053 | |
| 1054 | put_unaligned_le32(v, buf); |
| 1055 | return fwrite(buf, 1, 4, f) == 4 ? 0 : -1; |
| 1056 | } |
| 1057 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1058 | static int write32_as_text(uint32_t v, FILE *f) |
| 1059 | { |
| 1060 | return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1; |
| 1061 | } |
| 1062 | |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1063 | static void emit_relocs(int as_text, int use_real_mode) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1064 | { |
| 1065 | int i; |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1066 | int (*write_reloc)(uint32_t, FILE *) = write32; |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1067 | int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
| 1068 | const char *symname); |
| 1069 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1070 | #if ELF_BITS == 64 |
| 1071 | if (!use_real_mode) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1072 | do_reloc = do_reloc64; |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1073 | else |
| 1074 | die("--realmode not valid for a 64-bit ELF file"); |
| 1075 | #else |
| 1076 | if (!use_real_mode) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1077 | do_reloc = do_reloc32; |
| 1078 | else |
| 1079 | do_reloc = do_reloc_real; |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1080 | #endif |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1081 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1082 | /* Collect up the relocations */ |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1083 | walk_relocs(do_reloc); |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1084 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1085 | if (relocs16.count && !use_real_mode) |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1086 | die("Segment relocations found but --realmode not specified\n"); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1087 | |
| 1088 | /* Order the relocations for more efficient processing */ |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1089 | sort_relocs(&relocs32); |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 1090 | #if ELF_BITS == 64 |
| 1091 | sort_relocs(&relocs32neg); |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1092 | sort_relocs(&relocs64); |
Markus Trippelsdorf | 7ebb916 | 2016-12-15 13:45:13 +0100 | [diff] [blame] | 1093 | #else |
| 1094 | sort_relocs(&relocs16); |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 1095 | #endif |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1096 | |
| 1097 | /* Print the relocations */ |
| 1098 | if (as_text) { |
| 1099 | /* Print the relocations in a form suitable that |
| 1100 | * gas will like. |
| 1101 | */ |
| 1102 | printf(".section \".data.reloc\",\"a\"\n"); |
| 1103 | printf(".balign 4\n"); |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1104 | write_reloc = write32_as_text; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1105 | } |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1106 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1107 | if (use_real_mode) { |
| 1108 | write_reloc(relocs16.count, stdout); |
| 1109 | for (i = 0; i < relocs16.count; i++) |
| 1110 | write_reloc(relocs16.offset[i], stdout); |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1111 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1112 | write_reloc(relocs32.count, stdout); |
| 1113 | for (i = 0; i < relocs32.count; i++) |
| 1114 | write_reloc(relocs32.offset[i], stdout); |
| 1115 | } else { |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 1116 | #if ELF_BITS == 64 |
| 1117 | /* Print a stop */ |
| 1118 | write_reloc(0, stdout); |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1119 | |
Jan Beulich | 6d24c5f | 2014-11-04 08:50:18 +0000 | [diff] [blame] | 1120 | /* Now print each relocation */ |
| 1121 | for (i = 0; i < relocs64.count; i++) |
| 1122 | write_reloc(relocs64.offset[i], stdout); |
| 1123 | |
| 1124 | /* Print a stop */ |
| 1125 | write_reloc(0, stdout); |
| 1126 | |
| 1127 | /* Now print each inverse 32-bit relocation */ |
| 1128 | for (i = 0; i < relocs32neg.count; i++) |
| 1129 | write_reloc(relocs32neg.offset[i], stdout); |
| 1130 | #endif |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1131 | |
Kees Cook | 5d442e6 | 2013-04-12 13:13:43 -0700 | [diff] [blame] | 1132 | /* Print a stop */ |
| 1133 | write_reloc(0, stdout); |
| 1134 | |
| 1135 | /* Now print each relocation */ |
| 1136 | for (i = 0; i < relocs32.count; i++) |
| 1137 | write_reloc(relocs32.offset[i], stdout); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1138 | } |
| 1139 | } |
| 1140 | |
Michael Davidson | 214a887 | 2014-01-21 12:32:23 -0800 | [diff] [blame] | 1141 | /* |
| 1142 | * As an aid to debugging problems with different linkers |
| 1143 | * print summary information about the relocs. |
| 1144 | * Since different linkers tend to emit the sections in |
| 1145 | * different orders we use the section names in the output. |
| 1146 | */ |
| 1147 | static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, |
| 1148 | const char *symname) |
| 1149 | { |
| 1150 | printf("%s\t%s\t%s\t%s\n", |
| 1151 | sec_name(sec->shdr.sh_info), |
| 1152 | rel_type(ELF_R_TYPE(rel->r_info)), |
| 1153 | symname, |
Kristen Carlson Accardi | a54c401 | 2021-10-13 10:57:39 -0700 | [diff] [blame] | 1154 | sec_name(sym_index(sym))); |
Michael Davidson | 214a887 | 2014-01-21 12:32:23 -0800 | [diff] [blame] | 1155 | return 0; |
| 1156 | } |
| 1157 | |
| 1158 | static void print_reloc_info(void) |
| 1159 | { |
| 1160 | printf("reloc section\treloc type\tsymbol\tsymbol section\n"); |
| 1161 | walk_relocs(do_reloc_info); |
| 1162 | } |
| 1163 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1164 | #if ELF_BITS == 64 |
| 1165 | # define process process_64 |
| 1166 | #else |
| 1167 | # define process process_32 |
| 1168 | #endif |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1169 | |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1170 | void process(FILE *fp, int use_real_mode, int as_text, |
Michael Davidson | 214a887 | 2014-01-21 12:32:23 -0800 | [diff] [blame] | 1171 | int show_absolute_syms, int show_absolute_relocs, |
| 1172 | int show_reloc_info) |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1173 | { |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1174 | regex_init(use_real_mode); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1175 | read_ehdr(fp); |
| 1176 | read_shdrs(fp); |
| 1177 | read_strtabs(fp); |
| 1178 | read_symtabs(fp); |
| 1179 | read_relocs(fp); |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1180 | if (ELF_BITS == 64) |
Kees Cook | 946166a | 2013-04-12 13:13:44 -0700 | [diff] [blame] | 1181 | percpu_init(); |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1182 | if (show_absolute_syms) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1183 | print_absolute_symbols(); |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1184 | return; |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1185 | } |
| 1186 | if (show_absolute_relocs) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1187 | print_absolute_relocs(); |
H. Peter Anvin | c889ba8 | 2013-04-16 16:02:58 -0700 | [diff] [blame] | 1188 | return; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1189 | } |
Michael Davidson | 214a887 | 2014-01-21 12:32:23 -0800 | [diff] [blame] | 1190 | if (show_reloc_info) { |
| 1191 | print_reloc_info(); |
| 1192 | return; |
| 1193 | } |
H. Peter Anvin | 6520fe5 | 2012-05-08 21:22:24 +0300 | [diff] [blame] | 1194 | emit_relocs(as_text, use_real_mode); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 1195 | } |