Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 1 | /* |
| 2 | * libkmod - interface to kernel module operations |
| 3 | * |
Lucas De Marchi | e6b0e49 | 2013-01-16 11:27:21 -0200 | [diff] [blame] | 4 | * Copyright (C) 2011-2013 ProFUSION embedded systems |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This library is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
Lucas De Marchi | dea2dfe | 2014-12-25 23:32:03 -0200 | [diff] [blame] | 17 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 18 | */ |
| 19 | |
Lucas De Marchi | c2e4286 | 2014-10-03 01:41:42 -0300 | [diff] [blame] | 20 | #include <assert.h> |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 21 | #include <elf.h> |
Lucas De Marchi | c2e4286 | 2014-10-03 01:41:42 -0300 | [diff] [blame] | 22 | #include <errno.h> |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 25 | |
Lucas De Marchi | 96573a0 | 2014-10-03 00:01:35 -0300 | [diff] [blame] | 26 | #include <shared/util.h> |
| 27 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 28 | #include "libkmod.h" |
Lucas De Marchi | 83b855a | 2013-07-04 16:13:11 -0300 | [diff] [blame] | 29 | #include "libkmod-internal.h" |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 30 | |
| 31 | enum kmod_elf_class { |
| 32 | KMOD_ELF_32 = (1 << 1), |
| 33 | KMOD_ELF_64 = (1 << 2), |
| 34 | KMOD_ELF_LSB = (1 << 3), |
| 35 | KMOD_ELF_MSB = (1 << 4) |
| 36 | }; |
| 37 | |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 38 | /* as defined in module-init-tools */ |
| 39 | struct kmod_modversion32 { |
| 40 | uint32_t crc; |
| 41 | char name[64 - sizeof(uint32_t)]; |
| 42 | }; |
| 43 | |
| 44 | struct kmod_modversion64 { |
| 45 | uint64_t crc; |
| 46 | char name[64 - sizeof(uint64_t)]; |
| 47 | }; |
| 48 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 49 | struct kmod_elf { |
| 50 | const uint8_t *memory; |
| 51 | uint8_t *changed; |
| 52 | uint64_t size; |
| 53 | enum kmod_elf_class class; |
| 54 | struct kmod_elf_header { |
| 55 | struct { |
| 56 | uint64_t offset; |
| 57 | uint16_t count; |
| 58 | uint16_t entry_size; |
| 59 | } section; |
| 60 | struct { |
| 61 | uint16_t section; /* index of the strings section */ |
| 62 | uint64_t size; |
| 63 | uint64_t offset; |
| 64 | uint32_t nameoff; /* offset in strings itself */ |
| 65 | } strings; |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 66 | uint16_t machine; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 67 | } header; |
| 68 | }; |
| 69 | |
| 70 | //#define ENABLE_ELFDBG 1 |
| 71 | |
| 72 | #if defined(ENABLE_LOGGING) && defined(ENABLE_ELFDBG) |
| 73 | #define ELFDBG(elf, ...) \ |
Jan Engelhardt | 87beacc | 2011-12-20 16:27:40 +0100 | [diff] [blame] | 74 | _elf_dbg(elf, __FILE__, __LINE__, __func__, __VA_ARGS__); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 75 | |
| 76 | static inline void _elf_dbg(const struct kmod_elf *elf, const char *fname, unsigned line, const char *func, const char *fmt, ...) |
| 77 | { |
| 78 | va_list args; |
| 79 | |
| 80 | fprintf(stderr, "ELFDBG-%d%c: %s:%u %s() ", |
| 81 | (elf->class & KMOD_ELF_32) ? 32 : 64, |
| 82 | (elf->class & KMOD_ELF_MSB) ? 'M' : 'L', |
| 83 | fname, line, func); |
| 84 | va_start(args, fmt); |
| 85 | vfprintf(stderr, fmt, args); |
| 86 | va_end(args); |
| 87 | } |
| 88 | #else |
| 89 | #define ELFDBG(elf, ...) |
| 90 | #endif |
| 91 | |
| 92 | |
| 93 | static int elf_identify(const void *memory, uint64_t size) |
| 94 | { |
| 95 | const uint8_t *p = memory; |
| 96 | int class = 0; |
| 97 | |
| 98 | if (size <= EI_NIDENT || memcmp(p, ELFMAG, SELFMAG) != 0) |
| 99 | return -ENOEXEC; |
| 100 | |
| 101 | switch (p[EI_CLASS]) { |
| 102 | case ELFCLASS32: |
| 103 | if (size <= sizeof(Elf32_Ehdr)) |
| 104 | return -EINVAL; |
| 105 | class |= KMOD_ELF_32; |
| 106 | break; |
| 107 | case ELFCLASS64: |
| 108 | if (size <= sizeof(Elf64_Ehdr)) |
| 109 | return -EINVAL; |
| 110 | class |= KMOD_ELF_64; |
| 111 | break; |
| 112 | default: |
| 113 | return -EINVAL; |
| 114 | } |
| 115 | |
| 116 | switch (p[EI_DATA]) { |
| 117 | case ELFDATA2LSB: |
| 118 | class |= KMOD_ELF_LSB; |
| 119 | break; |
| 120 | case ELFDATA2MSB: |
| 121 | class |= KMOD_ELF_MSB; |
| 122 | break; |
| 123 | default: |
| 124 | return -EINVAL; |
| 125 | } |
| 126 | |
| 127 | return class; |
| 128 | } |
| 129 | |
| 130 | static inline uint64_t elf_get_uint(const struct kmod_elf *elf, uint64_t offset, uint16_t size) |
| 131 | { |
| 132 | const uint8_t *p; |
| 133 | uint64_t ret = 0; |
| 134 | size_t i; |
| 135 | |
| 136 | assert(size <= sizeof(uint64_t)); |
| 137 | assert(offset + size <= elf->size); |
| 138 | if (offset + size > elf->size) { |
| 139 | ELFDBG(elf, "out of bounds: %"PRIu64" + %"PRIu16" = %"PRIu64"> %"PRIu64" (ELF size)\n", |
| 140 | offset, size, offset + size, elf->size); |
| 141 | return (uint64_t)-1; |
| 142 | } |
| 143 | |
| 144 | p = elf->memory + offset; |
| 145 | if (elf->class & KMOD_ELF_MSB) { |
| 146 | for (i = 0; i < size; i++) |
Gustavo Sverzut Barbieri | fc8e58b | 2011-12-19 21:51:31 -0200 | [diff] [blame] | 147 | ret = (ret << 8) | p[i]; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 148 | } else { |
| 149 | for (i = 1; i <= size; i++) |
| 150 | ret = (ret << 8) | p[size - i]; |
| 151 | } |
| 152 | |
| 153 | ELFDBG(elf, "size=%"PRIu16" offset=%"PRIu64" value=%"PRIu64"\n", |
| 154 | size, offset, ret); |
| 155 | |
| 156 | return ret; |
| 157 | } |
| 158 | |
| 159 | static inline int elf_set_uint(struct kmod_elf *elf, uint64_t offset, uint64_t size, uint64_t value) |
| 160 | { |
| 161 | uint8_t *p; |
| 162 | size_t i; |
| 163 | |
| 164 | ELFDBG(elf, "size=%"PRIu16" offset=%"PRIu64" value=%"PRIu64" write memory=%p\n", |
| 165 | size, offset, value, elf->changed); |
| 166 | |
| 167 | assert(size <= sizeof(uint64_t)); |
| 168 | assert(offset + size <= elf->size); |
| 169 | if (offset + size > elf->size) { |
| 170 | ELFDBG(elf, "out of bounds: %"PRIu64" + %"PRIu16" = %"PRIu64"> %"PRIu64" (ELF size)\n", |
| 171 | offset, size, offset + size, elf->size); |
| 172 | return -1; |
| 173 | } |
| 174 | |
| 175 | if (elf->changed == NULL) { |
| 176 | elf->changed = malloc(elf->size); |
| 177 | if (elf->changed == NULL) |
| 178 | return -errno; |
| 179 | memcpy(elf->changed, elf->memory, elf->size); |
| 180 | elf->memory = elf->changed; |
| 181 | ELFDBG(elf, "copied memory to allow writing.\n"); |
| 182 | } |
| 183 | |
| 184 | p = elf->changed + offset; |
| 185 | if (elf->class & KMOD_ELF_MSB) { |
| 186 | for (i = 1; i <= size; i++) { |
| 187 | p[size - i] = value & 0xff; |
| 188 | value = (value & 0xffffffffffffff00) >> 8; |
| 189 | } |
| 190 | } else { |
| 191 | for (i = 0; i < size; i++) { |
| 192 | p[i] = value & 0xff; |
| 193 | value = (value & 0xffffffffffffff00) >> 8; |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static inline const void *elf_get_mem(const struct kmod_elf *elf, uint64_t offset) |
| 201 | { |
| 202 | assert(offset < elf->size); |
| 203 | if (offset >= elf->size) { |
| 204 | ELFDBG(elf, "out-of-bounds: %"PRIu64" >= %"PRIu64" (ELF size)\n", |
| 205 | offset, elf->size); |
| 206 | return NULL; |
| 207 | } |
| 208 | return elf->memory + offset; |
| 209 | } |
| 210 | |
| 211 | static inline const void *elf_get_section_header(const struct kmod_elf *elf, uint16_t idx) |
| 212 | { |
| 213 | assert(idx != SHN_UNDEF); |
| 214 | assert(idx < elf->header.section.count); |
| 215 | if (idx == SHN_UNDEF || idx >= elf->header.section.count) { |
| 216 | ELFDBG(elf, "invalid section number: %"PRIu16", last=%"PRIu16"\n", |
| 217 | idx, elf->header.section.count); |
| 218 | return NULL; |
| 219 | } |
| 220 | return elf_get_mem(elf, elf->header.section.offset + |
Lucas De Marchi | d98f2d3 | 2015-02-28 16:07:55 -0300 | [diff] [blame] | 221 | (uint64_t)(idx * elf->header.section.entry_size)); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 222 | } |
| 223 | |
| 224 | static inline int elf_get_section_info(const struct kmod_elf *elf, uint16_t idx, uint64_t *offset, uint64_t *size, uint32_t *nameoff) |
| 225 | { |
| 226 | const uint8_t *p = elf_get_section_header(elf, idx); |
| 227 | uint64_t min_size, off = p - elf->memory; |
| 228 | |
| 229 | if (p == NULL) { |
| 230 | ELFDBG(elf, "no section at %"PRIu16"\n", idx); |
| 231 | *offset = 0; |
| 232 | *size = 0; |
| 233 | *nameoff = 0; |
| 234 | return -EINVAL; |
| 235 | } |
| 236 | |
| 237 | #define READV(field) \ |
| 238 | elf_get_uint(elf, off + offsetof(typeof(*hdr), field), sizeof(hdr->field)) |
| 239 | |
| 240 | if (elf->class & KMOD_ELF_32) { |
Lucas De Marchi | 9e2eadb | 2012-05-23 20:28:53 -0300 | [diff] [blame] | 241 | const Elf32_Shdr *hdr _unused_ = (const Elf32_Shdr *)p; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 242 | *size = READV(sh_size); |
| 243 | *offset = READV(sh_offset); |
| 244 | *nameoff = READV(sh_name); |
| 245 | } else { |
Lucas De Marchi | 9e2eadb | 2012-05-23 20:28:53 -0300 | [diff] [blame] | 246 | const Elf64_Shdr *hdr _unused_ = (const Elf64_Shdr *)p; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 247 | *size = READV(sh_size); |
| 248 | *offset = READV(sh_offset); |
| 249 | *nameoff = READV(sh_name); |
| 250 | } |
| 251 | #undef READV |
| 252 | |
Lucas De Marchi | 6684102 | 2015-02-10 10:46:26 -0200 | [diff] [blame] | 253 | if (addu64_overflow(*offset, *size, &min_size) |
| 254 | || min_size > elf->size) { |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 255 | ELFDBG(elf, "out-of-bounds: %"PRIu64" >= %"PRIu64" (ELF size)\n", |
| 256 | min_size, elf->size); |
| 257 | return -EINVAL; |
| 258 | } |
| 259 | |
| 260 | ELFDBG(elf, "section=%"PRIu16" is: offset=%"PRIu64" size=%"PRIu64" nameoff=%"PRIu32"\n", |
| 261 | idx, *offset, *size, *nameoff); |
| 262 | |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | static const char *elf_get_strings_section(const struct kmod_elf *elf, uint64_t *size) |
| 267 | { |
| 268 | *size = elf->header.strings.size; |
| 269 | return elf_get_mem(elf, elf->header.strings.offset); |
| 270 | } |
| 271 | |
| 272 | struct kmod_elf *kmod_elf_new(const void *memory, off_t size) |
| 273 | { |
| 274 | struct kmod_elf *elf; |
Tobias Stoeckmann | 249dc59 | 2015-02-10 19:46:40 +0100 | [diff] [blame] | 275 | uint64_t min_size; |
| 276 | size_t shdrs_size, shdr_size; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 277 | int class; |
| 278 | |
Lucas De Marchi | a20a37c | 2013-04-15 14:14:07 -0300 | [diff] [blame] | 279 | assert_cc(sizeof(uint16_t) == sizeof(Elf32_Half)); |
| 280 | assert_cc(sizeof(uint16_t) == sizeof(Elf64_Half)); |
| 281 | assert_cc(sizeof(uint32_t) == sizeof(Elf32_Word)); |
| 282 | assert_cc(sizeof(uint32_t) == sizeof(Elf64_Word)); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 283 | |
| 284 | class = elf_identify(memory, size); |
| 285 | if (class < 0) { |
| 286 | errno = -class; |
| 287 | return NULL; |
| 288 | } |
| 289 | |
| 290 | elf = malloc(sizeof(struct kmod_elf)); |
| 291 | if (elf == NULL) { |
| 292 | return NULL; |
| 293 | } |
| 294 | |
| 295 | elf->memory = memory; |
| 296 | elf->changed = NULL; |
| 297 | elf->size = size; |
| 298 | elf->class = class; |
| 299 | |
| 300 | #define READV(field) \ |
| 301 | elf_get_uint(elf, offsetof(typeof(*hdr), field), sizeof(hdr->field)) |
| 302 | |
| 303 | #define LOAD_HEADER \ |
| 304 | elf->header.section.offset = READV(e_shoff); \ |
| 305 | elf->header.section.count = READV(e_shnum); \ |
| 306 | elf->header.section.entry_size = READV(e_shentsize); \ |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 307 | elf->header.strings.section = READV(e_shstrndx); \ |
| 308 | elf->header.machine = READV(e_machine) |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 309 | if (elf->class & KMOD_ELF_32) { |
Lucas De Marchi | 9e2eadb | 2012-05-23 20:28:53 -0300 | [diff] [blame] | 310 | const Elf32_Ehdr *hdr _unused_ = elf_get_mem(elf, 0); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 311 | LOAD_HEADER; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 312 | shdr_size = sizeof(Elf32_Shdr); |
| 313 | } else { |
Lucas De Marchi | 9e2eadb | 2012-05-23 20:28:53 -0300 | [diff] [blame] | 314 | const Elf64_Ehdr *hdr _unused_ = elf_get_mem(elf, 0); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 315 | LOAD_HEADER; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 316 | shdr_size = sizeof(Elf64_Shdr); |
| 317 | } |
| 318 | #undef LOAD_HEADER |
| 319 | #undef READV |
| 320 | |
| 321 | ELFDBG(elf, "section: offset=%"PRIu64" count=%"PRIu16" entry_size=%"PRIu16" strings index=%"PRIu16"\n", |
| 322 | elf->header.section.offset, |
| 323 | elf->header.section.count, |
| 324 | elf->header.section.entry_size, |
| 325 | elf->header.strings.section); |
| 326 | |
| 327 | if (elf->header.section.entry_size != shdr_size) { |
| 328 | ELFDBG(elf, "unexpected section entry size: %"PRIu16", expected %"PRIu16"\n", |
| 329 | elf->header.section.entry_size, shdr_size); |
| 330 | goto invalid; |
| 331 | } |
Tobias Stoeckmann | 249dc59 | 2015-02-10 19:46:40 +0100 | [diff] [blame] | 332 | shdrs_size = shdr_size * elf->header.section.count; |
| 333 | if (addu64_overflow(shdrs_size, elf->header.section.offset, &min_size) |
| 334 | || min_size > elf->size) { |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 335 | ELFDBG(elf, "file is too short to hold sections\n"); |
| 336 | goto invalid; |
| 337 | } |
| 338 | |
| 339 | if (elf_get_section_info(elf, elf->header.strings.section, |
| 340 | &elf->header.strings.offset, |
| 341 | &elf->header.strings.size, |
| 342 | &elf->header.strings.nameoff) < 0) { |
| 343 | ELFDBG(elf, "could not get strings section\n"); |
| 344 | goto invalid; |
| 345 | } else { |
| 346 | uint64_t slen; |
| 347 | const char *s = elf_get_strings_section(elf, &slen); |
| 348 | if (slen == 0 || s[slen - 1] != '\0') { |
| 349 | ELFDBG(elf, "strings section does not ends with \\0\n"); |
| 350 | goto invalid; |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | return elf; |
| 355 | |
| 356 | invalid: |
| 357 | free(elf); |
| 358 | errno = EINVAL; |
| 359 | return NULL; |
| 360 | } |
| 361 | |
| 362 | void kmod_elf_unref(struct kmod_elf *elf) |
| 363 | { |
| 364 | free(elf->changed); |
| 365 | free(elf); |
| 366 | } |
| 367 | |
| 368 | const void *kmod_elf_get_memory(const struct kmod_elf *elf) |
| 369 | { |
| 370 | return elf->memory; |
| 371 | } |
| 372 | |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 373 | static int elf_find_section(const struct kmod_elf *elf, const char *section) |
| 374 | { |
| 375 | uint64_t nameslen; |
| 376 | const char *names = elf_get_strings_section(elf, &nameslen); |
| 377 | uint16_t i; |
| 378 | |
| 379 | for (i = 1; i < elf->header.section.count; i++) { |
| 380 | uint64_t off, size; |
| 381 | uint32_t nameoff; |
| 382 | const char *n; |
| 383 | int err = elf_get_section_info(elf, i, &off, &size, &nameoff); |
| 384 | if (err < 0) |
| 385 | continue; |
| 386 | if (nameoff >= nameslen) |
| 387 | continue; |
| 388 | n = names + nameoff; |
| 389 | if (!streq(section, n)) |
| 390 | continue; |
| 391 | |
| 392 | return i; |
| 393 | } |
| 394 | |
| 395 | return -ENOENT; |
| 396 | } |
| 397 | |
Lucas De Marchi | ea17e2b | 2012-01-26 01:21:17 -0200 | [diff] [blame] | 398 | int kmod_elf_get_section(const struct kmod_elf *elf, const char *section, const void **buf, uint64_t *buf_size) |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 399 | { |
| 400 | uint64_t nameslen; |
| 401 | const char *names = elf_get_strings_section(elf, &nameslen); |
| 402 | uint16_t i; |
| 403 | |
| 404 | *buf = NULL; |
| 405 | *buf_size = 0; |
| 406 | |
| 407 | for (i = 1; i < elf->header.section.count; i++) { |
| 408 | uint64_t off, size; |
| 409 | uint32_t nameoff; |
| 410 | const char *n; |
| 411 | int err = elf_get_section_info(elf, i, &off, &size, &nameoff); |
| 412 | if (err < 0) |
| 413 | continue; |
| 414 | if (nameoff >= nameslen) |
| 415 | continue; |
| 416 | n = names + nameoff; |
| 417 | if (!streq(section, n)) |
| 418 | continue; |
| 419 | |
| 420 | *buf = elf_get_mem(elf, off); |
| 421 | *buf_size = size; |
| 422 | return 0; |
| 423 | } |
| 424 | |
| 425 | return -ENOENT; |
| 426 | } |
| 427 | |
| 428 | /* array will be allocated with strings in a single malloc, just free *array */ |
| 429 | int kmod_elf_get_strings(const struct kmod_elf *elf, const char *section, char ***array) |
| 430 | { |
Luis Felipe Strano Moraes | a969376 | 2011-12-20 07:11:46 -0800 | [diff] [blame] | 431 | size_t i, j, count; |
| 432 | uint64_t size; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 433 | const void *buf; |
| 434 | const char *strings; |
Lucas De Marchi | f8fa525 | 2011-12-20 03:25:23 -0200 | [diff] [blame] | 435 | char *s, **a; |
| 436 | int err; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 437 | |
| 438 | *array = NULL; |
| 439 | |
| 440 | err = kmod_elf_get_section(elf, section, &buf, &size); |
| 441 | if (err < 0) |
| 442 | return err; |
Lucas De Marchi | 052656f | 2011-12-20 03:10:58 -0200 | [diff] [blame] | 443 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 444 | strings = buf; |
| 445 | if (strings == NULL || size == 0) |
| 446 | return 0; |
| 447 | |
| 448 | /* skip zero padding */ |
| 449 | while (strings[0] == '\0' && size > 1) { |
| 450 | strings++; |
| 451 | size--; |
| 452 | } |
Lucas De Marchi | 052656f | 2011-12-20 03:10:58 -0200 | [diff] [blame] | 453 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 454 | if (size <= 1) |
| 455 | return 0; |
| 456 | |
Lucas De Marchi | 76b8031 | 2011-12-20 12:04:21 -0200 | [diff] [blame] | 457 | for (i = 0, count = 0; i < size; ) { |
| 458 | if (strings[i] != '\0') { |
| 459 | i++; |
Lucas De Marchi | 4f0f0e7 | 2011-12-20 03:08:09 -0200 | [diff] [blame] | 460 | continue; |
Lucas De Marchi | 76b8031 | 2011-12-20 12:04:21 -0200 | [diff] [blame] | 461 | } |
| 462 | |
| 463 | while (strings[i] == '\0' && i < size) |
| 464 | i++; |
Lucas De Marchi | 4f0f0e7 | 2011-12-20 03:08:09 -0200 | [diff] [blame] | 465 | |
Lucas De Marchi | 4f0f0e7 | 2011-12-20 03:08:09 -0200 | [diff] [blame] | 466 | count++; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 467 | } |
Lucas De Marchi | 052656f | 2011-12-20 03:10:58 -0200 | [diff] [blame] | 468 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 469 | if (strings[i - 1] != '\0') |
| 470 | count++; |
| 471 | |
Lucas De Marchi | 3267026 | 2011-12-20 03:09:58 -0200 | [diff] [blame] | 472 | *array = a = malloc(size + 1 + sizeof(char *) * (count + 1)); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 473 | if (*array == NULL) |
| 474 | return -errno; |
| 475 | |
Lucas De Marchi | f8fa525 | 2011-12-20 03:25:23 -0200 | [diff] [blame] | 476 | s = (char *)(a + count + 1); |
| 477 | memcpy(s, strings, size); |
| 478 | |
| 479 | /* make sure the last string is NULL-terminated */ |
| 480 | s[size] = '\0'; |
Lucas De Marchi | 3267026 | 2011-12-20 03:09:58 -0200 | [diff] [blame] | 481 | a[count] = NULL; |
Lucas De Marchi | f8fa525 | 2011-12-20 03:25:23 -0200 | [diff] [blame] | 482 | a[0] = s; |
Lucas De Marchi | 052656f | 2011-12-20 03:10:58 -0200 | [diff] [blame] | 483 | |
Lucas De Marchi | 76b8031 | 2011-12-20 12:04:21 -0200 | [diff] [blame] | 484 | for (i = 0, j = 1; j < count && i < size; ) { |
| 485 | if (s[i] != '\0') { |
| 486 | i++; |
Lucas De Marchi | f8fa525 | 2011-12-20 03:25:23 -0200 | [diff] [blame] | 487 | continue; |
Lucas De Marchi | 76b8031 | 2011-12-20 12:04:21 -0200 | [diff] [blame] | 488 | } |
Lucas De Marchi | 052656f | 2011-12-20 03:10:58 -0200 | [diff] [blame] | 489 | |
Lucas De Marchi | 76b8031 | 2011-12-20 12:04:21 -0200 | [diff] [blame] | 490 | while (strings[i] == '\0' && i < size) |
| 491 | i++; |
| 492 | |
| 493 | a[j] = &s[i]; |
Lucas De Marchi | f8fa525 | 2011-12-20 03:25:23 -0200 | [diff] [blame] | 494 | j++; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 495 | } |
| 496 | |
| 497 | return count; |
| 498 | } |
| 499 | |
| 500 | /* array will be allocated with strings in a single malloc, just free *array */ |
| 501 | int kmod_elf_get_modversions(const struct kmod_elf *elf, struct kmod_modversion **array) |
| 502 | { |
Luis Felipe Strano Moraes | a969376 | 2011-12-20 07:11:46 -0800 | [diff] [blame] | 503 | size_t off, offcrc, slen; |
| 504 | uint64_t size; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 505 | struct kmod_modversion *a; |
| 506 | const void *buf; |
| 507 | char *itr; |
| 508 | int i, count, err; |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 509 | #define MODVERSION_SEC_SIZE (sizeof(struct kmod_modversion64)) |
| 510 | |
Lucas De Marchi | a20a37c | 2013-04-15 14:14:07 -0300 | [diff] [blame] | 511 | assert_cc(sizeof(struct kmod_modversion64) == |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 512 | sizeof(struct kmod_modversion32)); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 513 | |
Lucas De Marchi | fea655d | 2014-03-07 01:17:10 -0300 | [diff] [blame] | 514 | if (elf->class & KMOD_ELF_32) |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 515 | offcrc = sizeof(uint32_t); |
| 516 | else |
| 517 | offcrc = sizeof(uint64_t); |
| 518 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 519 | *array = NULL; |
| 520 | |
| 521 | err = kmod_elf_get_section(elf, "__versions", &buf, &size); |
| 522 | if (err < 0) |
| 523 | return err; |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 524 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 525 | if (buf == NULL || size == 0) |
| 526 | return 0; |
| 527 | |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 528 | if (size % MODVERSION_SEC_SIZE != 0) |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 529 | return -EINVAL; |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 530 | |
| 531 | count = size / MODVERSION_SEC_SIZE; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 532 | |
| 533 | off = (const uint8_t *)buf - elf->memory; |
| 534 | slen = 0; |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 535 | |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 536 | for (i = 0; i < count; i++, off += MODVERSION_SEC_SIZE) { |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 537 | const char *symbol = elf_get_mem(elf, off + offcrc); |
| 538 | |
Gustavo Sverzut Barbieri | 1c58590 | 2011-12-19 21:53:24 -0200 | [diff] [blame] | 539 | if (symbol[0] == '.') |
| 540 | symbol++; |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 541 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 542 | slen += strlen(symbol) + 1; |
| 543 | } |
| 544 | |
| 545 | *array = a = malloc(sizeof(struct kmod_modversion) * count + slen); |
| 546 | if (*array == NULL) |
| 547 | return -errno; |
| 548 | |
| 549 | itr = (char *)(a + count); |
| 550 | off = (const uint8_t *)buf - elf->memory; |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 551 | |
Lucas De Marchi | 58b7191 | 2011-12-20 04:02:15 -0200 | [diff] [blame] | 552 | for (i = 0; i < count; i++, off += MODVERSION_SEC_SIZE) { |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 553 | uint64_t crc = elf_get_uint(elf, off, offcrc); |
| 554 | const char *symbol = elf_get_mem(elf, off + offcrc); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 555 | size_t symbollen; |
Lucas De Marchi | 51c409b | 2011-12-20 11:41:19 -0200 | [diff] [blame] | 556 | |
Gustavo Sverzut Barbieri | 1c58590 | 2011-12-19 21:53:24 -0200 | [diff] [blame] | 557 | if (symbol[0] == '.') |
| 558 | symbol++; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 559 | |
| 560 | a[i].crc = crc; |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 561 | a[i].bind = KMOD_SYMBOL_UNDEF; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 562 | a[i].symbol = itr; |
| 563 | symbollen = strlen(symbol) + 1; |
| 564 | memcpy(itr, symbol, symbollen); |
| 565 | itr += symbollen; |
| 566 | } |
| 567 | |
| 568 | return count; |
| 569 | } |
| 570 | |
| 571 | int kmod_elf_strip_section(struct kmod_elf *elf, const char *section) |
| 572 | { |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 573 | uint64_t off, size; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 574 | const void *buf; |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 575 | int idx = elf_find_section(elf, section); |
| 576 | uint64_t val; |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 577 | |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 578 | if (idx < 0) |
| 579 | return idx; |
| 580 | |
| 581 | buf = elf_get_section_header(elf, idx); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 582 | off = (const uint8_t *)buf - elf->memory; |
| 583 | |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 584 | if (elf->class & KMOD_ELF_32) { |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 585 | off += offsetof(Elf32_Shdr, sh_flags); |
| 586 | size = sizeof(((Elf32_Shdr *)buf)->sh_flags); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 587 | } else { |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 588 | off += offsetof(Elf64_Shdr, sh_flags); |
| 589 | size = sizeof(((Elf64_Shdr *)buf)->sh_flags); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 590 | } |
Lucas De Marchi | a457866 | 2012-11-21 20:17:25 -0200 | [diff] [blame] | 591 | |
| 592 | val = elf_get_uint(elf, off, size); |
| 593 | val &= ~(uint64_t)SHF_ALLOC; |
| 594 | |
| 595 | return elf_set_uint(elf, off, size, val); |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 596 | } |
| 597 | |
| 598 | int kmod_elf_strip_vermagic(struct kmod_elf *elf) |
| 599 | { |
| 600 | uint64_t i, size; |
| 601 | const void *buf; |
| 602 | const char *strings; |
| 603 | int err; |
| 604 | |
| 605 | err = kmod_elf_get_section(elf, ".modinfo", &buf, &size); |
| 606 | if (err < 0) |
| 607 | return err; |
| 608 | strings = buf; |
| 609 | if (strings == NULL || size == 0) |
| 610 | return 0; |
| 611 | |
| 612 | /* skip zero padding */ |
| 613 | while (strings[0] == '\0' && size > 1) { |
| 614 | strings++; |
| 615 | size--; |
| 616 | } |
| 617 | if (size <= 1) |
| 618 | return 0; |
| 619 | |
| 620 | for (i = 0; i < size; i++) { |
| 621 | const char *s; |
| 622 | size_t off, len; |
| 623 | |
| 624 | if (strings[i] == '\0') |
| 625 | continue; |
| 626 | if (i + 1 >= size) |
| 627 | continue; |
| 628 | |
| 629 | s = strings + i; |
| 630 | len = sizeof("vermagic=") - 1; |
| 631 | if (i + len >= size) |
| 632 | continue; |
| 633 | if (strncmp(s, "vermagic=", len) != 0) { |
| 634 | i += strlen(s); |
| 635 | continue; |
| 636 | } |
Gustavo Sverzut Barbieri | 708624a | 2011-12-18 01:25:06 -0200 | [diff] [blame] | 637 | off = (const uint8_t *)s - elf->memory; |
| 638 | |
| 639 | if (elf->changed == NULL) { |
| 640 | elf->changed = malloc(elf->size); |
| 641 | if (elf->changed == NULL) |
| 642 | return -errno; |
| 643 | memcpy(elf->changed, elf->memory, elf->size); |
| 644 | elf->memory = elf->changed; |
| 645 | ELFDBG(elf, "copied memory to allow writing.\n"); |
| 646 | } |
| 647 | |
| 648 | len = strlen(s); |
| 649 | ELFDBG(elf, "clear .modinfo vermagic \"%s\" (%zd bytes)\n", |
| 650 | s, len); |
| 651 | memset(elf->changed + off, '\0', len); |
| 652 | return 0; |
| 653 | } |
| 654 | |
| 655 | ELFDBG(elf, "no vermagic found in .modinfo\n"); |
| 656 | return -ENOENT; |
| 657 | } |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 658 | |
| 659 | |
| 660 | static int kmod_elf_get_symbols_symtab(const struct kmod_elf *elf, struct kmod_modversion **array) |
| 661 | { |
| 662 | uint64_t i, last, size; |
| 663 | const void *buf; |
| 664 | const char *strings; |
| 665 | char *itr; |
| 666 | struct kmod_modversion *a; |
| 667 | int count, err; |
| 668 | |
| 669 | *array = NULL; |
| 670 | |
| 671 | err = kmod_elf_get_section(elf, "__ksymtab_strings", &buf, &size); |
| 672 | if (err < 0) |
| 673 | return err; |
| 674 | strings = buf; |
| 675 | if (strings == NULL || size == 0) |
| 676 | return 0; |
| 677 | |
| 678 | /* skip zero padding */ |
| 679 | while (strings[0] == '\0' && size > 1) { |
| 680 | strings++; |
| 681 | size--; |
| 682 | } |
| 683 | if (size <= 1) |
| 684 | return 0; |
| 685 | |
| 686 | last = 0; |
| 687 | for (i = 0, count = 0; i < size; i++) { |
| 688 | if (strings[i] == '\0') { |
| 689 | if (last == i) { |
| 690 | last = i + 1; |
| 691 | continue; |
| 692 | } |
| 693 | count++; |
| 694 | last = i + 1; |
| 695 | } |
| 696 | } |
| 697 | if (strings[i - 1] != '\0') |
| 698 | count++; |
| 699 | |
| 700 | *array = a = malloc(size + 1 + sizeof(struct kmod_modversion) * count); |
| 701 | if (*array == NULL) |
| 702 | return -errno; |
| 703 | |
| 704 | itr = (char *)(a + count); |
| 705 | last = 0; |
| 706 | for (i = 0, count = 0; i < size; i++) { |
| 707 | if (strings[i] == '\0') { |
| 708 | size_t slen = i - last; |
| 709 | if (last == i) { |
| 710 | last = i + 1; |
| 711 | continue; |
| 712 | } |
| 713 | a[count].crc = 0; |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 714 | a[count].bind = KMOD_SYMBOL_GLOBAL; |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 715 | a[count].symbol = itr; |
| 716 | memcpy(itr, strings + last, slen); |
| 717 | itr[slen] = '\0'; |
| 718 | itr += slen + 1; |
| 719 | count++; |
| 720 | last = i + 1; |
| 721 | } |
| 722 | } |
| 723 | if (strings[i - 1] != '\0') { |
| 724 | size_t slen = i - last; |
| 725 | a[count].crc = 0; |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 726 | a[count].bind = KMOD_SYMBOL_GLOBAL; |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 727 | a[count].symbol = itr; |
| 728 | memcpy(itr, strings + last, slen); |
| 729 | itr[slen] = '\0'; |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 730 | count++; |
| 731 | } |
| 732 | |
| 733 | return count; |
| 734 | } |
| 735 | |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 736 | static inline uint8_t kmod_symbol_bind_from_elf(uint8_t elf_value) |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 737 | { |
| 738 | switch (elf_value) { |
| 739 | case STB_LOCAL: |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 740 | return KMOD_SYMBOL_LOCAL; |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 741 | case STB_GLOBAL: |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 742 | return KMOD_SYMBOL_GLOBAL; |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 743 | case STB_WEAK: |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 744 | return KMOD_SYMBOL_WEAK; |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 745 | default: |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 746 | return KMOD_SYMBOL_NONE; |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 747 | } |
| 748 | } |
| 749 | |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 750 | /* array will be allocated with strings in a single malloc, just free *array */ |
| 751 | int kmod_elf_get_symbols(const struct kmod_elf *elf, struct kmod_modversion **array) |
| 752 | { |
| 753 | static const char crc_str[] = "__crc_"; |
| 754 | static const size_t crc_strlen = sizeof(crc_str) - 1; |
| 755 | uint64_t strtablen, symtablen, str_off, sym_off; |
| 756 | const void *strtab, *symtab; |
| 757 | struct kmod_modversion *a; |
| 758 | char *itr; |
| 759 | size_t slen, symlen; |
| 760 | int i, count, symcount, err; |
| 761 | |
| 762 | err = kmod_elf_get_section(elf, ".strtab", &strtab, &strtablen); |
| 763 | if (err < 0) { |
| 764 | ELFDBG(elf, "no .strtab found.\n"); |
| 765 | goto fallback; |
| 766 | } |
| 767 | |
| 768 | err = kmod_elf_get_section(elf, ".symtab", &symtab, &symtablen); |
| 769 | if (err < 0) { |
| 770 | ELFDBG(elf, "no .symtab found.\n"); |
| 771 | goto fallback; |
| 772 | } |
| 773 | |
| 774 | if (elf->class & KMOD_ELF_32) |
| 775 | symlen = sizeof(Elf32_Sym); |
| 776 | else |
| 777 | symlen = sizeof(Elf64_Sym); |
| 778 | |
| 779 | if (symtablen % symlen != 0) { |
| 780 | ELFDBG(elf, "unexpected .symtab of length %"PRIu64", not multiple of %"PRIu64" as expected.\n", symtablen, symlen); |
| 781 | goto fallback; |
| 782 | } |
| 783 | |
| 784 | symcount = symtablen / symlen; |
| 785 | count = 0; |
| 786 | slen = 0; |
| 787 | str_off = (const uint8_t *)strtab - elf->memory; |
| 788 | sym_off = (const uint8_t *)symtab - elf->memory + symlen; |
| 789 | for (i = 1; i < symcount; i++, sym_off += symlen) { |
| 790 | const char *name; |
| 791 | uint32_t name_off; |
| 792 | |
| 793 | #define READV(field) \ |
| 794 | elf_get_uint(elf, sym_off + offsetof(typeof(*s), field),\ |
| 795 | sizeof(s->field)) |
| 796 | if (elf->class & KMOD_ELF_32) { |
| 797 | Elf32_Sym *s; |
| 798 | name_off = READV(st_name); |
| 799 | } else { |
| 800 | Elf64_Sym *s; |
| 801 | name_off = READV(st_name); |
| 802 | } |
| 803 | #undef READV |
| 804 | if (name_off >= strtablen) { |
| 805 | ELFDBG(elf, ".strtab is %"PRIu64" bytes, but .symtab entry %d wants to access offset %"PRIu32".\n", strtablen, i, name_off); |
| 806 | goto fallback; |
| 807 | } |
| 808 | |
| 809 | name = elf_get_mem(elf, str_off + name_off); |
| 810 | |
| 811 | if (strncmp(name, crc_str, crc_strlen) != 0) |
| 812 | continue; |
| 813 | slen += strlen(name + crc_strlen) + 1; |
| 814 | count++; |
| 815 | } |
| 816 | |
| 817 | if (count == 0) |
| 818 | goto fallback; |
| 819 | |
| 820 | *array = a = malloc(sizeof(struct kmod_modversion) * count + slen); |
| 821 | if (*array == NULL) |
| 822 | return -errno; |
| 823 | |
| 824 | itr = (char *)(a + count); |
| 825 | count = 0; |
| 826 | str_off = (const uint8_t *)strtab - elf->memory; |
| 827 | sym_off = (const uint8_t *)symtab - elf->memory + symlen; |
| 828 | for (i = 1; i < symcount; i++, sym_off += symlen) { |
| 829 | const char *name; |
| 830 | uint32_t name_off; |
| 831 | uint64_t crc; |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 832 | uint8_t info, bind; |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 833 | |
| 834 | #define READV(field) \ |
| 835 | elf_get_uint(elf, sym_off + offsetof(typeof(*s), field),\ |
| 836 | sizeof(s->field)) |
| 837 | if (elf->class & KMOD_ELF_32) { |
| 838 | Elf32_Sym *s; |
| 839 | name_off = READV(st_name); |
| 840 | crc = READV(st_value); |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 841 | info = READV(st_info); |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 842 | } else { |
| 843 | Elf64_Sym *s; |
| 844 | name_off = READV(st_name); |
| 845 | crc = READV(st_value); |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 846 | info = READV(st_info); |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 847 | } |
| 848 | #undef READV |
| 849 | name = elf_get_mem(elf, str_off + name_off); |
| 850 | if (strncmp(name, crc_str, crc_strlen) != 0) |
| 851 | continue; |
| 852 | name += crc_strlen; |
| 853 | |
Gustavo Sverzut Barbieri | 4b55bef | 2011-12-20 10:11:22 -0200 | [diff] [blame] | 854 | if (elf->class & KMOD_ELF_32) |
| 855 | bind = ELF32_ST_BIND(info); |
| 856 | else |
| 857 | bind = ELF64_ST_BIND(info); |
| 858 | |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 859 | a[count].crc = crc; |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 860 | a[count].bind = kmod_symbol_bind_from_elf(bind); |
Gustavo Sverzut Barbieri | 45e6db9 | 2011-12-19 21:23:13 -0200 | [diff] [blame] | 861 | a[count].symbol = itr; |
| 862 | slen = strlen(name); |
| 863 | memcpy(itr, name, slen); |
| 864 | itr[slen] = '\0'; |
| 865 | itr += slen + 1; |
| 866 | count++; |
| 867 | } |
| 868 | return count; |
| 869 | |
| 870 | fallback: |
| 871 | ELFDBG(elf, "Falling back to __ksymtab_strings!\n"); |
| 872 | return kmod_elf_get_symbols_symtab(elf, array); |
| 873 | } |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 874 | |
| 875 | static int kmod_elf_crc_find(const struct kmod_elf *elf, const void *versions, uint64_t versionslen, const char *name, uint64_t *crc) |
| 876 | { |
| 877 | size_t verlen, crclen, off; |
| 878 | uint64_t i; |
| 879 | |
| 880 | if (elf->class & KMOD_ELF_32) { |
| 881 | struct kmod_modversion32 *mv; |
| 882 | verlen = sizeof(*mv); |
| 883 | crclen = sizeof(mv->crc); |
| 884 | } else { |
| 885 | struct kmod_modversion64 *mv; |
| 886 | verlen = sizeof(*mv); |
| 887 | crclen = sizeof(mv->crc); |
| 888 | } |
| 889 | |
| 890 | off = (const uint8_t *)versions - elf->memory; |
| 891 | for (i = 0; i < versionslen; i += verlen) { |
| 892 | const char *symbol = elf_get_mem(elf, off + i + crclen); |
| 893 | if (!streq(name, symbol)) |
| 894 | continue; |
| 895 | *crc = elf_get_uint(elf, off + i, crclen); |
| 896 | return i / verlen; |
| 897 | } |
| 898 | |
| 899 | ELFDBG(elf, "could not find crc for symbol '%s'\n", name); |
| 900 | *crc = 0; |
| 901 | return -1; |
| 902 | } |
| 903 | |
| 904 | /* from module-init-tools:elfops_core.c */ |
| 905 | #ifndef STT_REGISTER |
| 906 | #define STT_REGISTER 13 /* Global register reserved to app. */ |
| 907 | #endif |
| 908 | |
| 909 | /* array will be allocated with strings in a single malloc, just free *array */ |
| 910 | int kmod_elf_get_dependency_symbols(const struct kmod_elf *elf, struct kmod_modversion **array) |
| 911 | { |
| 912 | uint64_t versionslen, strtablen, symtablen, str_off, sym_off, ver_off; |
| 913 | const void *versions, *strtab, *symtab; |
| 914 | struct kmod_modversion *a; |
| 915 | char *itr; |
| 916 | size_t slen, verlen, symlen, crclen; |
| 917 | int i, count, symcount, vercount, err; |
| 918 | bool handle_register_symbols; |
| 919 | uint8_t *visited_versions; |
| 920 | uint64_t *symcrcs; |
| 921 | |
| 922 | err = kmod_elf_get_section(elf, "__versions", &versions, &versionslen); |
| 923 | if (err < 0) { |
| 924 | versions = NULL; |
| 925 | versionslen = 0; |
| 926 | verlen = 0; |
| 927 | crclen = 0; |
| 928 | } else { |
| 929 | if (elf->class & KMOD_ELF_32) { |
| 930 | struct kmod_modversion32 *mv; |
| 931 | verlen = sizeof(*mv); |
| 932 | crclen = sizeof(mv->crc); |
| 933 | } else { |
| 934 | struct kmod_modversion64 *mv; |
| 935 | verlen = sizeof(*mv); |
| 936 | crclen = sizeof(mv->crc); |
| 937 | } |
| 938 | if (versionslen % verlen != 0) { |
| 939 | ELFDBG(elf, "unexpected __versions of length %"PRIu64", not multiple of %zd as expected.\n", versionslen, verlen); |
| 940 | versions = NULL; |
| 941 | versionslen = 0; |
| 942 | } |
| 943 | } |
| 944 | |
| 945 | err = kmod_elf_get_section(elf, ".strtab", &strtab, &strtablen); |
| 946 | if (err < 0) { |
| 947 | ELFDBG(elf, "no .strtab found.\n"); |
| 948 | return -EINVAL; |
| 949 | } |
| 950 | |
| 951 | err = kmod_elf_get_section(elf, ".symtab", &symtab, &symtablen); |
| 952 | if (err < 0) { |
| 953 | ELFDBG(elf, "no .symtab found.\n"); |
| 954 | return -EINVAL; |
| 955 | } |
| 956 | |
| 957 | if (elf->class & KMOD_ELF_32) |
| 958 | symlen = sizeof(Elf32_Sym); |
| 959 | else |
| 960 | symlen = sizeof(Elf64_Sym); |
| 961 | |
| 962 | if (symtablen % symlen != 0) { |
| 963 | ELFDBG(elf, "unexpected .symtab of length %"PRIu64", not multiple of %"PRIu64" as expected.\n", symtablen, symlen); |
| 964 | return -EINVAL; |
| 965 | } |
| 966 | |
| 967 | if (versionslen == 0) { |
| 968 | vercount = 0; |
| 969 | visited_versions = NULL; |
| 970 | } else { |
| 971 | vercount = versionslen / verlen; |
| 972 | visited_versions = calloc(vercount, sizeof(uint8_t)); |
| 973 | if (visited_versions == NULL) |
| 974 | return -ENOMEM; |
| 975 | } |
| 976 | |
| 977 | handle_register_symbols = (elf->header.machine == EM_SPARC || |
| 978 | elf->header.machine == EM_SPARCV9); |
| 979 | |
| 980 | symcount = symtablen / symlen; |
| 981 | count = 0; |
| 982 | slen = 0; |
| 983 | str_off = (const uint8_t *)strtab - elf->memory; |
| 984 | sym_off = (const uint8_t *)symtab - elf->memory + symlen; |
| 985 | |
| 986 | symcrcs = calloc(symcount, sizeof(uint64_t)); |
| 987 | if (symcrcs == NULL) { |
| 988 | free(visited_versions); |
| 989 | return -ENOMEM; |
| 990 | } |
| 991 | |
| 992 | for (i = 1; i < symcount; i++, sym_off += symlen) { |
| 993 | const char *name; |
| 994 | uint64_t crc; |
| 995 | uint32_t name_off; |
| 996 | uint16_t secidx; |
| 997 | uint8_t info; |
| 998 | int idx; |
| 999 | |
| 1000 | #define READV(field) \ |
| 1001 | elf_get_uint(elf, sym_off + offsetof(typeof(*s), field),\ |
| 1002 | sizeof(s->field)) |
| 1003 | if (elf->class & KMOD_ELF_32) { |
| 1004 | Elf32_Sym *s; |
| 1005 | name_off = READV(st_name); |
| 1006 | secidx = READV(st_shndx); |
| 1007 | info = READV(st_info); |
| 1008 | } else { |
| 1009 | Elf64_Sym *s; |
| 1010 | name_off = READV(st_name); |
| 1011 | secidx = READV(st_shndx); |
| 1012 | info = READV(st_info); |
| 1013 | } |
| 1014 | #undef READV |
| 1015 | if (secidx != SHN_UNDEF) |
| 1016 | continue; |
| 1017 | |
| 1018 | if (handle_register_symbols) { |
| 1019 | uint8_t type; |
| 1020 | if (elf->class & KMOD_ELF_32) |
| 1021 | type = ELF32_ST_TYPE(info); |
| 1022 | else |
| 1023 | type = ELF64_ST_TYPE(info); |
| 1024 | |
| 1025 | /* Not really undefined: sparc gcc 3.3 creates |
| 1026 | * U references when you have global asm |
| 1027 | * variables, to avoid anyone else misusing |
| 1028 | * them. |
| 1029 | */ |
| 1030 | if (type == STT_REGISTER) |
| 1031 | continue; |
| 1032 | } |
| 1033 | |
| 1034 | if (name_off >= strtablen) { |
| 1035 | ELFDBG(elf, ".strtab is %"PRIu64" bytes, but .symtab entry %d wants to access offset %"PRIu32".\n", strtablen, i, name_off); |
| 1036 | free(visited_versions); |
| 1037 | free(symcrcs); |
| 1038 | return -EINVAL; |
| 1039 | } |
| 1040 | |
| 1041 | name = elf_get_mem(elf, str_off + name_off); |
| 1042 | if (name[0] == '\0') { |
| 1043 | ELFDBG(elf, "empty symbol name at index %"PRIu64"\n", i); |
| 1044 | continue; |
| 1045 | } |
| 1046 | |
| 1047 | slen += strlen(name) + 1; |
| 1048 | count++; |
| 1049 | |
| 1050 | idx = kmod_elf_crc_find(elf, versions, versionslen, name, &crc); |
| 1051 | if (idx >= 0 && visited_versions != NULL) |
| 1052 | visited_versions[idx] = 1; |
| 1053 | symcrcs[i] = crc; |
| 1054 | } |
| 1055 | |
| 1056 | if (visited_versions != NULL) { |
| 1057 | /* module_layout/struct_module are not visited, but needed */ |
| 1058 | ver_off = (const uint8_t *)versions - elf->memory; |
| 1059 | for (i = 0; i < vercount; i++) { |
| 1060 | if (visited_versions[i] == 0) { |
| 1061 | const char *name; |
| 1062 | name = elf_get_mem(elf, ver_off + i * verlen + crclen); |
| 1063 | slen += strlen(name) + 1; |
| 1064 | |
| 1065 | count++; |
| 1066 | } |
| 1067 | } |
| 1068 | } |
| 1069 | |
| 1070 | if (count == 0) { |
| 1071 | free(visited_versions); |
| 1072 | free(symcrcs); |
Gustavo Sverzut Barbieri | 599a032 | 2012-01-03 14:53:15 -0200 | [diff] [blame] | 1073 | *array = NULL; |
Gustavo Sverzut Barbieri | 674f859 | 2011-12-20 11:54:53 -0200 | [diff] [blame] | 1074 | return 0; |
| 1075 | } |
| 1076 | |
| 1077 | *array = a = malloc(sizeof(struct kmod_modversion) * count + slen); |
| 1078 | if (*array == NULL) { |
| 1079 | free(visited_versions); |
| 1080 | free(symcrcs); |
| 1081 | return -errno; |
| 1082 | } |
| 1083 | |
| 1084 | itr = (char *)(a + count); |
| 1085 | count = 0; |
| 1086 | str_off = (const uint8_t *)strtab - elf->memory; |
| 1087 | sym_off = (const uint8_t *)symtab - elf->memory + symlen; |
| 1088 | for (i = 1; i < symcount; i++, sym_off += symlen) { |
| 1089 | const char *name; |
| 1090 | uint64_t crc; |
| 1091 | uint32_t name_off; |
| 1092 | uint16_t secidx; |
| 1093 | uint8_t info, bind; |
| 1094 | |
| 1095 | #define READV(field) \ |
| 1096 | elf_get_uint(elf, sym_off + offsetof(typeof(*s), field),\ |
| 1097 | sizeof(s->field)) |
| 1098 | if (elf->class & KMOD_ELF_32) { |
| 1099 | Elf32_Sym *s; |
| 1100 | name_off = READV(st_name); |
| 1101 | secidx = READV(st_shndx); |
| 1102 | info = READV(st_info); |
| 1103 | } else { |
| 1104 | Elf64_Sym *s; |
| 1105 | name_off = READV(st_name); |
| 1106 | secidx = READV(st_shndx); |
| 1107 | info = READV(st_info); |
| 1108 | } |
| 1109 | #undef READV |
| 1110 | if (secidx != SHN_UNDEF) |
| 1111 | continue; |
| 1112 | |
| 1113 | if (handle_register_symbols) { |
| 1114 | uint8_t type; |
| 1115 | if (elf->class & KMOD_ELF_32) |
| 1116 | type = ELF32_ST_TYPE(info); |
| 1117 | else |
| 1118 | type = ELF64_ST_TYPE(info); |
| 1119 | |
| 1120 | /* Not really undefined: sparc gcc 3.3 creates |
| 1121 | * U references when you have global asm |
| 1122 | * variables, to avoid anyone else misusing |
| 1123 | * them. |
| 1124 | */ |
| 1125 | if (type == STT_REGISTER) |
| 1126 | continue; |
| 1127 | } |
| 1128 | |
| 1129 | name = elf_get_mem(elf, str_off + name_off); |
| 1130 | if (name[0] == '\0') { |
| 1131 | ELFDBG(elf, "empty symbol name at index %"PRIu64"\n", i); |
| 1132 | continue; |
| 1133 | } |
| 1134 | |
| 1135 | if (elf->class & KMOD_ELF_32) |
| 1136 | bind = ELF32_ST_BIND(info); |
| 1137 | else |
| 1138 | bind = ELF64_ST_BIND(info); |
| 1139 | if (bind == STB_WEAK) |
| 1140 | bind = KMOD_SYMBOL_WEAK; |
| 1141 | else |
| 1142 | bind = KMOD_SYMBOL_UNDEF; |
| 1143 | |
| 1144 | slen = strlen(name); |
| 1145 | crc = symcrcs[i]; |
| 1146 | |
| 1147 | a[count].crc = crc; |
| 1148 | a[count].bind = bind; |
| 1149 | a[count].symbol = itr; |
| 1150 | memcpy(itr, name, slen); |
| 1151 | itr[slen] = '\0'; |
| 1152 | itr += slen + 1; |
| 1153 | |
| 1154 | count++; |
| 1155 | } |
| 1156 | |
| 1157 | free(symcrcs); |
| 1158 | |
| 1159 | if (visited_versions == NULL) |
| 1160 | return count; |
| 1161 | |
| 1162 | /* add unvisited (module_layout/struct_module) */ |
| 1163 | ver_off = (const uint8_t *)versions - elf->memory; |
| 1164 | for (i = 0; i < vercount; i++) { |
| 1165 | const char *name; |
| 1166 | uint64_t crc; |
| 1167 | |
| 1168 | if (visited_versions[i] != 0) |
| 1169 | continue; |
| 1170 | |
| 1171 | name = elf_get_mem(elf, ver_off + i * verlen + crclen); |
| 1172 | slen = strlen(name); |
| 1173 | crc = elf_get_uint(elf, ver_off + i * verlen, crclen); |
| 1174 | |
| 1175 | a[count].crc = crc; |
| 1176 | a[count].bind = KMOD_SYMBOL_UNDEF; |
| 1177 | a[count].symbol = itr; |
| 1178 | memcpy(itr, name, slen); |
| 1179 | itr[slen] = '\0'; |
| 1180 | itr += slen + 1; |
| 1181 | |
| 1182 | count++; |
| 1183 | } |
| 1184 | free(visited_versions); |
| 1185 | return count; |
| 1186 | } |