| 1 | #include <stdint.h> |
| 2 | #include <stddef.h> |
| 3 | #include <lib/misc.h> |
| 4 | #include <sys/cpu.h> |
| 5 | #include <lib/libc.h> |
| 6 | #include <lib/elf.h> |
| 7 | #include <lib/print.h> |
| 8 | #include <lib/rand.h> |
| 9 | #include <lib/elsewhere.h> |
| 10 | #include <mm/pmm.h> |
| 11 | #include <fs/file.h> |
| 12 | |
| 13 | #define ET_NONE 0 |
| 14 | #define ET_REL 1 |
| 15 | #define ET_EXEC 2 |
| 16 | #define ET_DYN 3 |
| 17 | |
| 18 | #define PT_LOAD 0x00000001 |
| 19 | #define PT_DYNAMIC 0x00000002 |
| 20 | #define PT_INTERP 0x00000003 |
| 21 | #define PT_PHDR 0x00000006 |
| 22 | |
| 23 | #define DT_NULL 0x00000000 |
| 24 | #define DT_NEEDED 0x00000001 |
| 25 | #define DT_RELA 0x00000007 |
| 26 | #define DT_RELASZ 0x00000008 |
| 27 | #define DT_RELAENT 0x00000009 |
| 28 | #define DT_RELR 0x00000024 |
| 29 | #define DT_RELRSZ 0x00000023 |
| 30 | #define DT_RELRENT 0x00000025 |
| 31 | #define DT_SYMTAB 0x00000006 |
| 32 | #define DT_SYMENT 0x0000000b |
| 33 | #define DT_STRTAB 0x00000005 |
| 34 | #define DT_PLTREL 0x00000014 |
| 35 | #define DT_PLTRELSZ 0x00000002 |
| 36 | #define DT_JMPREL 0x00000017 |
| 37 | #define DT_FLAGS_1 0x6ffffffb |
| 38 | |
| 39 | #define DF_1_PIE 0x08000000 |
| 40 | |
| 41 | #define ABI_SYSV 0x00 |
| 42 | #define ARCH_X86_64 0x3e |
| 43 | #define ARCH_X86_32 0x03 |
| 44 | #define ARCH_AARCH64 0xb7 |
| 45 | #define ARCH_RISCV 0xf3 |
| 46 | #define ARCH_LOONGARCH 0x102 |
| 47 | #define BITS_LE 0x01 |
| 48 | #define ELFCLASS32 0x01 |
| 49 | #define ELFCLASS64 0x02 |
| 50 | #define SHT_RELA 0x00000004 |
| 51 | #define SHN_UNDEF 0x00000000 |
| 52 | #define STB_WEAK 0x00000002 |
| 53 | #define R_X86_64_NONE 0x00000000 |
| 54 | #define R_AARCH64_NONE 0x00000000 |
| 55 | #define R_RISCV_NONE 0x00000000 |
| 56 | #define R_LARCH_NONE 0x00000000 |
| 57 | #define R_X86_64_RELATIVE 0x00000008 |
| 58 | #define R_AARCH64_RELATIVE 0x00000403 |
| 59 | #define R_RISCV_RELATIVE 0x00000003 |
| 60 | #define R_LARCH_RELATIVE 0x00000003 |
| 61 | #define R_X86_64_GLOB_DAT 0x00000006 |
| 62 | #define R_AARCH64_GLOB_DAT 0x00000401 |
| 63 | #define R_X86_64_JUMP_SLOT 0x00000007 |
| 64 | #define R_AARCH64_JUMP_SLOT 0x00000402 |
| 65 | #define R_RISCV_JUMP_SLOT 0x00000005 |
| 66 | #define R_LARCH_JUMP_SLOT 0x00000005 |
| 67 | #define R_X86_64_64 0x00000001 |
| 68 | #define R_RISCV_64 0x00000002 |
| 69 | #define R_LARCH_64 0x00000002 |
| 70 | #define R_AARCH64_ABS64 0x00000101 |
| 71 | |
| 72 | #define R_INTERNAL_RELR 0xfffffff0 |
| 73 | |
| 74 | /* Indices into identification array */ |
| 75 | #define EI_CLASS 4 |
| 76 | #define EI_DATA 5 |
| 77 | #define EI_VERSION 6 |
| 78 | #define EI_OSABI 7 |
| 79 | |
| 80 | struct elf32_hdr { |
| 81 | uint8_t ident[16]; |
| 82 | uint16_t type; |
| 83 | uint16_t machine; |
| 84 | uint32_t version; |
| 85 | uint32_t entry; |
| 86 | uint32_t phoff; |
| 87 | uint32_t shoff; |
| 88 | uint32_t flags; |
| 89 | uint16_t hdr_size; |
| 90 | uint16_t phdr_size; |
| 91 | uint16_t ph_num; |
| 92 | uint16_t shdr_size; |
| 93 | uint16_t sh_num; |
| 94 | uint16_t shstrndx; |
| 95 | }; |
| 96 | |
| 97 | struct elf64_phdr { |
| 98 | uint32_t p_type; |
| 99 | uint32_t p_flags; |
| 100 | uint64_t p_offset; |
| 101 | uint64_t p_vaddr; |
| 102 | uint64_t p_paddr; |
| 103 | uint64_t p_filesz; |
| 104 | uint64_t p_memsz; |
| 105 | uint64_t p_align; |
| 106 | }; |
| 107 | |
| 108 | struct elf32_phdr { |
| 109 | uint32_t p_type; |
| 110 | uint32_t p_offset; |
| 111 | uint32_t p_vaddr; |
| 112 | uint32_t p_paddr; |
| 113 | uint32_t p_filesz; |
| 114 | uint32_t p_memsz; |
| 115 | uint32_t p_flags; |
| 116 | uint32_t p_align; |
| 117 | }; |
| 118 | |
| 119 | struct elf64_rela { |
| 120 | uint64_t r_addr; |
| 121 | uint32_t r_info; |
| 122 | uint32_t r_symbol; |
| 123 | uint64_t r_addend; |
| 124 | }; |
| 125 | |
| 126 | struct elf32_dyn { |
| 127 | uint32_t d_tag; |
| 128 | uint32_t d_un; |
| 129 | }; |
| 130 | |
| 131 | struct elf64_dyn { |
| 132 | uint64_t d_tag; |
| 133 | uint64_t d_un; |
| 134 | }; |
| 135 | |
| 136 | static bool elf32_validate(struct elf32_hdr *hdr) { |
| 137 | if (strncmp((char *)hdr->ident, "\177ELF", 4)) { |
| 138 | panic(true, "elf: Not a valid ELF file."); |
| 139 | } |
| 140 | |
| 141 | if (hdr->ident[EI_DATA] != BITS_LE) { |
| 142 | panic(true, "elf: Not a Little-endian ELF file."); |
| 143 | } |
| 144 | |
| 145 | if (hdr->machine != ARCH_X86_32) { |
| 146 | panic(true, "elf: Not an IA-32 ELF file."); |
| 147 | } |
| 148 | |
| 149 | return true; |
| 150 | } |
| 151 | |
| 152 | static bool elf64_validate(struct elf64_hdr *hdr) { |
| 153 | if (strncmp((char *)hdr->ident, "\177ELF", 4)) { |
| 154 | panic(true, "elf: Not a valid ELF file."); |
| 155 | } |
| 156 | |
| 157 | if (hdr->ident[EI_DATA] != BITS_LE) { |
| 158 | panic(true, "elf: Not a Little-endian ELF file."); |
| 159 | } |
| 160 | |
| 161 | #if defined (__x86_64__) || defined (__i386__) |
| 162 | if (hdr->machine != ARCH_X86_64) { |
| 163 | panic(true, "elf: Not an x86-64 ELF file."); |
| 164 | } |
| 165 | #elif defined (__aarch64__) |
| 166 | if (hdr->machine != ARCH_AARCH64) { |
| 167 | panic(true, "elf: Not an aarch64 ELF file."); |
| 168 | } |
| 169 | #elif defined (__riscv) |
| 170 | if (hdr->machine != ARCH_RISCV && hdr->ident[EI_CLASS] == ELFCLASS64) { |
| 171 | panic(true, "elf: Not a riscv64 ELF file."); |
| 172 | } |
| 173 | #elif defined (__loongarch64) |
| 174 | if (hdr->machine != ARCH_LOONGARCH && hdr->ident[EI_CLASS] == ELFCLASS64) { |
| 175 | panic(true, "elf: Not a loongarch64 ELF file."); |
| 176 | } |
| 177 | #else |
| 178 | #error Unknown architecture |
| 179 | #endif |
| 180 | |
| 181 | return true; |
| 182 | } |
| 183 | |
| 184 | int elf_bits(uint8_t *elf, size_t file_size) { |
| 185 | if (file_size < sizeof(struct elf64_hdr)) { |
| 186 | return -1; |
| 187 | } |
| 188 | |
| 189 | struct elf64_hdr *hdr = (void *)elf; |
| 190 | |
| 191 | if (strncmp((char *)hdr->ident, "\177ELF", 4)) { |
| 192 | return -1; |
| 193 | } |
| 194 | |
| 195 | switch (hdr->machine) { |
| 196 | case ARCH_X86_64: |
| 197 | case ARCH_AARCH64: |
| 198 | return 64; |
| 199 | case ARCH_RISCV: |
| 200 | case ARCH_LOONGARCH: |
| 201 | if (hdr->ident[EI_CLASS] == ELFCLASS64) return 64; |
| 202 | if (hdr->ident[EI_CLASS] == ELFCLASS32) return 32; |
| 203 | return -1; |
| 204 | case ARCH_X86_32: |
| 205 | return 32; |
| 206 | default: |
| 207 | return -1; |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | struct elf_section_hdr_info elf64_section_hdr_info(uint8_t *elf, size_t file_size) { |
| 212 | struct elf_section_hdr_info info = {0}; |
| 213 | |
| 214 | struct elf64_hdr *hdr = (void *)elf; |
| 215 | |
| 216 | elf64_validate(hdr); |
| 217 | |
| 218 | if (CHECKED_ADD((uint64_t)hdr->sh_num * hdr->shdr_size, |
| 219 | hdr->shoff, return info) > file_size) { |
| 220 | return info; |
| 221 | } |
| 222 | |
| 223 | info.num = hdr->sh_num; |
| 224 | info.section_entry_size = hdr->shdr_size; |
| 225 | info.str_section_idx = hdr->shstrndx; |
| 226 | info.section_offset = hdr->shoff; |
| 227 | |
| 228 | return info; |
| 229 | } |
| 230 | |
| 231 | struct elf_section_hdr_info elf32_section_hdr_info(uint8_t *elf, size_t file_size) { |
| 232 | struct elf_section_hdr_info info = {0}; |
| 233 | |
| 234 | struct elf32_hdr *hdr = (void *)elf; |
| 235 | |
| 236 | elf32_validate(hdr); |
| 237 | |
| 238 | if (CHECKED_ADD((uint64_t)hdr->sh_num * hdr->shdr_size, |
| 239 | hdr->shoff, return info) > file_size) { |
| 240 | return info; |
| 241 | } |
| 242 | |
| 243 | info.num = hdr->sh_num; |
| 244 | info.section_entry_size = hdr->shdr_size; |
| 245 | info.str_section_idx = hdr->shstrndx; |
| 246 | info.section_offset = hdr->shoff; |
| 247 | |
| 248 | return info; |
| 249 | } |
| 250 | |
| 251 | static bool elf64_is_relocatable(uint8_t *elf, struct elf64_hdr *hdr) { |
| 252 | if (hdr->phdr_size < sizeof(struct elf64_phdr)) { |
| 253 | panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)"); |
| 254 | } |
| 255 | |
| 256 | if (hdr->type != ET_DYN) { |
| 257 | return false; |
| 258 | } |
| 259 | |
| 260 | // Find PT_DYNAMIC segment |
| 261 | for (size_t i = 0; i < hdr->ph_num; i++) { |
| 262 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 263 | |
| 264 | if (phdr->p_type != PT_DYNAMIC) { |
| 265 | continue; |
| 266 | } |
| 267 | |
| 268 | if (phdr->p_filesz == 0) { |
| 269 | panic(true, "elf: ELF file type is ET_DYN, but PT_DYNAMIC segment has 0 size"); |
| 270 | } |
| 271 | |
| 272 | return true; |
| 273 | } |
| 274 | |
| 275 | panic(true, "elf: ELF file type is ET_DYN, but PT_DYNAMIC segment missing"); |
| 276 | } |
| 277 | |
| 278 | // Translate a virtual address to a file offset using the phdr table. |
| 279 | // Returns false if the vaddr is not found in any PT_LOAD segment or the |
| 280 | // translated offset exceeds file bounds. |
| 281 | static bool elf64_translate_vaddr(uint8_t *elf, size_t file_size, |
| 282 | struct elf64_hdr *hdr, uint64_t *offset, uint64_t size_hint, |
| 283 | uint64_t *out_seg_size) { |
| 284 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 285 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 286 | |
| 287 | uint64_t seg_end = CHECKED_ADD(phdr->p_vaddr, phdr->p_filesz, continue); |
| 288 | |
| 289 | if (phdr->p_vaddr <= *offset && seg_end > *offset) { |
| 290 | if (out_seg_size != NULL) { |
| 291 | *out_seg_size = phdr->p_filesz - (*offset - phdr->p_vaddr); |
| 292 | } |
| 293 | *offset -= phdr->p_vaddr; |
| 294 | *offset += phdr->p_offset; |
| 295 | |
| 296 | // Validate translated offset + size_hint is within file |
| 297 | if (CHECKED_ADD(*offset, size_hint, return false) > file_size) { |
| 298 | return false; |
| 299 | } |
| 300 | return true; |
| 301 | } |
| 302 | } |
| 303 | return false; |
| 304 | } |
| 305 | |
| 306 | static void elf64_add_relocation_count(size_t *count, uint64_t add) { |
| 307 | if (add > SIZE_MAX - *count) { |
| 308 | panic(true, "elf: relocation count overflow"); |
| 309 | } |
| 310 | |
| 311 | *count += (size_t)add; |
| 312 | } |
| 313 | |
| 314 | static bool elf64_apply_relocations(uint8_t *elf, size_t file_size, struct elf64_hdr *hdr, void *buffer, uint64_t vaddr, size_t size, uint64_t slide) { |
| 315 | if (hdr->phdr_size < sizeof(struct elf64_phdr)) { |
| 316 | panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)"); |
| 317 | } |
| 318 | |
| 319 | uint64_t symtab_offset = 0; |
| 320 | uint64_t symtab_ent = 0; |
| 321 | uint64_t symtab_size = 0; // Size of symbol table (if known) |
| 322 | uint64_t strtab_offset = 0; |
| 323 | uint64_t strtab_size = 0; // Size of string table (if known) |
| 324 | |
| 325 | uint64_t dt_pltrel = 0; |
| 326 | uint64_t dt_pltrelsz = 0; |
| 327 | uint64_t dt_jmprel = 0; |
| 328 | |
| 329 | uint64_t relr_offset = 0; |
| 330 | uint64_t relr_size = 0; |
| 331 | uint64_t relr_ent = 0; |
| 332 | |
| 333 | uint64_t rela_offset = 0; |
| 334 | uint64_t rela_size = 0; |
| 335 | uint64_t rela_ent = 0; |
| 336 | |
| 337 | // Validate phdr table is within file bounds |
| 338 | if (CHECKED_ADD(hdr->phoff, CHECKED_MUL((uint64_t)hdr->ph_num, (uint64_t)hdr->phdr_size, |
| 339 | return false), return false) > file_size) { |
| 340 | return false; |
| 341 | } |
| 342 | |
| 343 | // Find DYN segment |
| 344 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 345 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 346 | |
| 347 | if (phdr->p_type != PT_DYNAMIC) |
| 348 | continue; |
| 349 | |
| 350 | // Validate PT_DYNAMIC segment is within file bounds |
| 351 | if (CHECKED_ADD(phdr->p_offset, phdr->p_filesz, return false) > file_size) { |
| 352 | return false; |
| 353 | } |
| 354 | |
| 355 | for (uint64_t j = 0; j < phdr->p_filesz / sizeof(struct elf64_dyn); j++) { |
| 356 | struct elf64_dyn *dyn = (void *)elf + (phdr->p_offset + j * sizeof(struct elf64_dyn)); |
| 357 | |
| 358 | switch (dyn->d_tag) { |
| 359 | case DT_RELA: |
| 360 | rela_offset = dyn->d_un; |
| 361 | break; |
| 362 | case DT_RELAENT: |
| 363 | rela_ent = dyn->d_un; |
| 364 | break; |
| 365 | case DT_RELASZ: |
| 366 | rela_size = dyn->d_un; |
| 367 | break; |
| 368 | case DT_RELR: |
| 369 | relr_offset = dyn->d_un; |
| 370 | break; |
| 371 | case DT_RELRENT: |
| 372 | relr_ent = dyn->d_un; |
| 373 | break; |
| 374 | case DT_RELRSZ: |
| 375 | relr_size = dyn->d_un; |
| 376 | break; |
| 377 | case DT_SYMTAB: |
| 378 | symtab_offset = dyn->d_un; |
| 379 | break; |
| 380 | case DT_STRTAB: |
| 381 | strtab_offset = dyn->d_un; |
| 382 | break; |
| 383 | case DT_SYMENT: |
| 384 | symtab_ent = dyn->d_un; |
| 385 | if (symtab_ent < sizeof(struct elf64_sym)) { |
| 386 | panic(true, "elf: symtab_ent < sizeof(struct elf64_sym)"); |
| 387 | } |
| 388 | break; |
| 389 | case DT_PLTREL: |
| 390 | dt_pltrel = dyn->d_un; |
| 391 | break; |
| 392 | case DT_PLTRELSZ: |
| 393 | dt_pltrelsz = dyn->d_un; |
| 394 | break; |
| 395 | case DT_JMPREL: |
| 396 | dt_jmprel = dyn->d_un; |
| 397 | break; |
| 398 | case DT_NEEDED: |
| 399 | panic(true, "elf: ELF file attempts to load a dynamically linked library"); |
| 400 | case DT_NULL: |
| 401 | goto end_of_pt_segment; |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | break; |
| 406 | } |
| 407 | end_of_pt_segment: |
| 408 | |
| 409 | if (rela_offset != 0) { |
| 410 | if (!elf64_translate_vaddr(elf, file_size, hdr, &rela_offset, rela_size, NULL)) { |
| 411 | panic(true, "elf: RELA vaddr translation failed or out of bounds"); |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | if (relr_offset != 0) { |
| 416 | if (!elf64_translate_vaddr(elf, file_size, hdr, &relr_offset, relr_size, NULL)) { |
| 417 | panic(true, "elf: RELR vaddr translation failed or out of bounds"); |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | if (symtab_offset != 0) { |
| 422 | if (!elf64_translate_vaddr(elf, file_size, hdr, &symtab_offset, 0, &symtab_size)) { |
| 423 | panic(true, "elf: SYMTAB vaddr translation failed or out of bounds"); |
| 424 | } |
| 425 | } |
| 426 | |
| 427 | if (strtab_offset != 0) { |
| 428 | if (!elf64_translate_vaddr(elf, file_size, hdr, &strtab_offset, 0, &strtab_size)) { |
| 429 | panic(true, "elf: STRTAB vaddr translation failed or out of bounds"); |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | if (dt_jmprel != 0) { |
| 434 | if (!elf64_translate_vaddr(elf, file_size, hdr, &dt_jmprel, dt_pltrelsz, NULL)) { |
| 435 | panic(true, "elf: JMPREL vaddr translation failed or out of bounds"); |
| 436 | } |
| 437 | } |
| 438 | |
| 439 | size_t relocs_i = 0; |
| 440 | if (relr_size != 0) { |
| 441 | if (relr_ent != 8) { |
| 442 | panic(true, "elf: relr_ent != 8"); |
| 443 | } |
| 444 | for (size_t i = 0; i < relr_size / relr_ent; i++) { |
| 445 | uint64_t entry = *((uint64_t *)(elf + relr_offset + i * relr_ent)); |
| 446 | |
| 447 | if ((entry & 1) == 0) { |
| 448 | elf64_add_relocation_count(&relocs_i, 1); |
| 449 | } else { |
| 450 | elf64_add_relocation_count(&relocs_i, __builtin_popcountll(entry) - 1); |
| 451 | } |
| 452 | } |
| 453 | } |
| 454 | size_t relr_count = relocs_i; |
| 455 | if (rela_size != 0) { |
| 456 | if (rela_ent < sizeof(struct elf64_rela)) { |
| 457 | panic(true, "elf: rela_ent < sizeof(struct elf64_rela)"); |
| 458 | } |
| 459 | if (rela_size % rela_ent != 0) { |
| 460 | panic(true, "elf: rela_size not a multiple of rela_ent"); |
| 461 | } |
| 462 | elf64_add_relocation_count(&relocs_i, rela_size / rela_ent); |
| 463 | } |
| 464 | if (dt_pltrelsz != 0) { |
| 465 | if (dt_pltrel != DT_RELA) { |
| 466 | panic(true, "elf: dt_pltrel != DT_RELA"); |
| 467 | } |
| 468 | if (rela_ent == 0) { |
| 469 | panic(true, "elf: dt_pltrelsz != 0 but rela_ent == 0"); |
| 470 | } |
| 471 | if (dt_pltrelsz % rela_ent != 0) { |
| 472 | panic(true, "elf: dt_pltrelsz not a multiple of rela_ent"); |
| 473 | } |
| 474 | elf64_add_relocation_count(&relocs_i, dt_pltrelsz / rela_ent); |
| 475 | } |
| 476 | struct elf64_rela **relocs = ext_mem_alloc_counted(relocs_i, sizeof(struct elf64_rela *)); |
| 477 | |
| 478 | if (relr_size != 0) { |
| 479 | size_t relr_i; |
| 480 | for (relr_i = 0; relr_i < relr_count; relr_i++) { |
| 481 | relocs[relr_i] = ext_mem_alloc(sizeof(struct elf64_rela)); |
| 482 | relocs[relr_i]->r_info = R_INTERNAL_RELR; |
| 483 | } |
| 484 | |
| 485 | // This logic is partially lifted from https://maskray.me/blog/2021-10-31-relative-relocations-and-relr |
| 486 | uint64_t where = 0; |
| 487 | relr_i = 0; |
| 488 | for (size_t i = 0; i < relr_size / relr_ent; i++) { |
| 489 | uint64_t entry = *((uint64_t *)(elf + relr_offset + i * relr_ent)); |
| 490 | |
| 491 | if ((entry & 1) == 0) { |
| 492 | where = entry; |
| 493 | relocs[relr_i++]->r_addr = where; |
| 494 | where += 8; |
| 495 | } else { |
| 496 | for (size_t j = 0; (entry >>= 1) != 0; j++) { |
| 497 | if ((entry & 1) != 0) { |
| 498 | relocs[relr_i++]->r_addr = where + j * 8; |
| 499 | } |
| 500 | } |
| 501 | where += 63 * 8; |
| 502 | } |
| 503 | } |
| 504 | } |
| 505 | |
| 506 | if (rela_size != 0) { |
| 507 | for (uint64_t i = relr_count, offset = 0; offset < rela_size; offset += rela_ent) { |
| 508 | relocs[i++] = (void *)elf + (rela_offset + offset); |
| 509 | } |
| 510 | } |
| 511 | |
| 512 | if (dt_pltrelsz != 0) { |
| 513 | for (uint64_t i = relr_count + rela_size / rela_ent, offset = 0; offset < dt_pltrelsz; offset += rela_ent) { |
| 514 | relocs[i++] = (void *)elf + (dt_jmprel + offset); |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | for (size_t i = 0; i < relocs_i; i++) { |
| 519 | struct elf64_rela *relocation = relocs[i]; |
| 520 | |
| 521 | // Relocation is before buffer |
| 522 | if (relocation->r_addr < vaddr) |
| 523 | continue; |
| 524 | |
| 525 | // Relocation is after buffer |
| 526 | if (size < 8 || relocation->r_addr > vaddr + size - 8) |
| 527 | continue; |
| 528 | |
| 529 | // It's inside it, calculate where it is |
| 530 | uint64_t *ptr = (uint64_t *)(buffer + (relocation->r_addr - vaddr)); |
| 531 | |
| 532 | switch (relocation->r_info) { |
| 533 | #if defined (__x86_64__) || defined (__i386__) |
| 534 | case R_X86_64_NONE: |
| 535 | #elif defined (__aarch64__) |
| 536 | case R_AARCH64_NONE: |
| 537 | #elif defined (__riscv) |
| 538 | case R_RISCV_NONE: |
| 539 | #elif defined (__loongarch64) |
| 540 | case R_LARCH_NONE: |
| 541 | #endif |
| 542 | { |
| 543 | break; |
| 544 | } |
| 545 | #if defined (__x86_64__) || defined (__i386__) |
| 546 | case R_X86_64_RELATIVE: |
| 547 | #elif defined (__aarch64__) |
| 548 | case R_AARCH64_RELATIVE: |
| 549 | #elif defined (__riscv) |
| 550 | case R_RISCV_RELATIVE: |
| 551 | #elif defined (__loongarch64) |
| 552 | case R_LARCH_RELATIVE: |
| 553 | #endif |
| 554 | { |
| 555 | *ptr = slide + relocation->r_addend; |
| 556 | break; |
| 557 | } |
| 558 | case R_INTERNAL_RELR: |
| 559 | { |
| 560 | *ptr += slide; |
| 561 | break; |
| 562 | } |
| 563 | #if defined (__x86_64__) || defined (__i386__) |
| 564 | case R_X86_64_GLOB_DAT: |
| 565 | case R_X86_64_JUMP_SLOT: |
| 566 | #elif defined (__aarch64__) |
| 567 | case R_AARCH64_GLOB_DAT: |
| 568 | case R_AARCH64_JUMP_SLOT: |
| 569 | #elif defined (__riscv) |
| 570 | case R_RISCV_JUMP_SLOT: |
| 571 | #elif defined (__loongarch64) |
| 572 | case R_LARCH_JUMP_SLOT: |
| 573 | #endif |
| 574 | { |
| 575 | if (symtab_offset == 0 || symtab_ent == 0) { |
| 576 | panic(true, "elf: Relocation requires symbol table but none present"); |
| 577 | } |
| 578 | if (symtab_size == 0) { |
| 579 | panic(true, "elf: Symtab vaddr translation failed"); |
| 580 | } |
| 581 | // Validate symbol index is within bounds |
| 582 | uint64_t sym_offset = CHECKED_MUL(symtab_ent, (uint64_t)relocation->r_symbol, |
| 583 | panic(true, "elf: Symbol offset overflow")); |
| 584 | if (symtab_size < sizeof(struct elf64_sym) |
| 585 | || sym_offset > symtab_size - sizeof(struct elf64_sym)) { |
| 586 | panic(true, "elf: Symbol index %u out of bounds", relocation->r_symbol); |
| 587 | } |
| 588 | struct elf64_sym *s = (void *)elf + symtab_offset + sym_offset; |
| 589 | if (s->st_shndx == SHN_UNDEF) { |
| 590 | if ((s->st_info >> 4) == STB_WEAK) { |
| 591 | *ptr = 0; |
| 592 | break; |
| 593 | } |
| 594 | if (strtab_size == 0) { |
| 595 | panic(true, "elf: Strtab vaddr translation failed"); |
| 596 | } |
| 597 | // Validate string table access |
| 598 | if (s->st_name >= strtab_size) { |
| 599 | panic(true, "elf: Symbol name offset out of bounds"); |
| 600 | } |
| 601 | panic(true, "elf: Unresolved symbol \"%s\"", elf + strtab_offset + s->st_name); |
| 602 | } |
| 603 | *ptr = slide + s->st_value |
| 604 | #if defined (__aarch64__) |
| 605 | + relocation->r_addend |
| 606 | #endif |
| 607 | ; |
| 608 | break; |
| 609 | } |
| 610 | #if defined (__x86_64__) || defined (__i386__) |
| 611 | case R_X86_64_64: |
| 612 | #elif defined (__aarch64__) |
| 613 | case R_AARCH64_ABS64: |
| 614 | #elif defined (__riscv) |
| 615 | case R_RISCV_64: |
| 616 | #elif defined (__loongarch64) |
| 617 | case R_LARCH_64: |
| 618 | #endif |
| 619 | { |
| 620 | if (symtab_offset == 0 || symtab_ent == 0) { |
| 621 | panic(true, "elf: Relocation requires symbol table but none present"); |
| 622 | } |
| 623 | if (symtab_size == 0) { |
| 624 | panic(true, "elf: Symtab vaddr translation failed"); |
| 625 | } |
| 626 | // Validate symbol index is within bounds |
| 627 | uint64_t sym_offset = CHECKED_MUL(symtab_ent, (uint64_t)relocation->r_symbol, |
| 628 | panic(true, "elf: Symbol offset overflow")); |
| 629 | if (symtab_size < sizeof(struct elf64_sym) |
| 630 | || sym_offset > symtab_size - sizeof(struct elf64_sym)) { |
| 631 | panic(true, "elf: Symbol index %u out of bounds", relocation->r_symbol); |
| 632 | } |
| 633 | struct elf64_sym *s = (void *)elf + symtab_offset + sym_offset; |
| 634 | if (s->st_shndx == SHN_UNDEF) { |
| 635 | if ((s->st_info >> 4) == STB_WEAK) { |
| 636 | *ptr = 0; |
| 637 | break; |
| 638 | } |
| 639 | if (strtab_size == 0) { |
| 640 | panic(true, "elf: Strtab vaddr translation failed"); |
| 641 | } |
| 642 | // Validate string table access |
| 643 | if (s->st_name >= strtab_size) { |
| 644 | panic(true, "elf: Symbol name offset out of bounds"); |
| 645 | } |
| 646 | panic(true, "elf: Unresolved symbol \"%s\"", elf + strtab_offset + s->st_name); |
| 647 | } |
| 648 | *ptr = slide + s->st_value + relocation->r_addend; |
| 649 | break; |
| 650 | } |
| 651 | default: { |
| 652 | panic(true, "elf: Unknown relocation type: %x", relocation->r_info); |
| 653 | } |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | for (size_t i = 0; i < relr_count; i++) { |
| 658 | pmm_free(relocs[i], sizeof(struct elf64_rela)); |
| 659 | } |
| 660 | pmm_free(relocs, relocs_i * sizeof(struct elf64_rela *)); |
| 661 | |
| 662 | return true; |
| 663 | } |
| 664 | |
| 665 | bool elf64_load_section(uint8_t *elf, size_t file_size, void *buffer, const char *name, size_t limit, uint64_t slide) { |
| 666 | struct elf64_hdr *hdr = (void *)elf; |
| 667 | |
| 668 | elf64_validate(hdr); |
| 669 | |
| 670 | if (hdr->sh_num == 0) { |
| 671 | return false; |
| 672 | } |
| 673 | |
| 674 | if (hdr->shdr_size < sizeof(struct elf64_shdr)) { |
| 675 | panic(true, "elf: shdr_size < sizeof(struct elf64_shdr)"); |
| 676 | } |
| 677 | |
| 678 | if (hdr->shstrndx >= hdr->sh_num) { |
| 679 | return false; |
| 680 | } |
| 681 | |
| 682 | // Validate section header table is within file bounds |
| 683 | uint64_t shdr_table_end = CHECKED_ADD(hdr->shoff, |
| 684 | CHECKED_MUL((uint64_t)hdr->sh_num, (uint64_t)hdr->shdr_size, return false), |
| 685 | return false); |
| 686 | if (shdr_table_end > file_size) { |
| 687 | return false; |
| 688 | } |
| 689 | |
| 690 | struct elf64_shdr *shstrtab = (void *)elf + (hdr->shoff + hdr->shstrndx * hdr->shdr_size); |
| 691 | |
| 692 | // Validate shstrtab offset and size are within file bounds |
| 693 | if (shstrtab->sh_offset >= file_size || shstrtab->sh_size > file_size - shstrtab->sh_offset) { |
| 694 | return false; |
| 695 | } |
| 696 | |
| 697 | char *names = (void *)elf + shstrtab->sh_offset; |
| 698 | |
| 699 | for (uint16_t i = 0; i < hdr->sh_num; i++) { |
| 700 | struct elf64_shdr *section = (void *)elf + (hdr->shoff + i * hdr->shdr_size); |
| 701 | |
| 702 | // Validate sh_name is within the string table |
| 703 | if (section->sh_name >= shstrtab->sh_size) { |
| 704 | continue; |
| 705 | } |
| 706 | |
| 707 | // Ensure the string is NUL-terminated within the string table |
| 708 | if (!memchr(&names[section->sh_name], '\0', shstrtab->sh_size - section->sh_name)) { |
| 709 | continue; |
| 710 | } |
| 711 | |
| 712 | if (strcmp(&names[section->sh_name], name) == 0) { |
| 713 | // Validate section data is within file bounds |
| 714 | if (section->sh_offset >= file_size || section->sh_size > file_size - section->sh_offset) { |
| 715 | return false; |
| 716 | } |
| 717 | |
| 718 | if (limit == 0) { |
| 719 | *(void **)buffer = ext_mem_alloc(section->sh_size); |
| 720 | buffer = *(void **)buffer; |
| 721 | limit = section->sh_size; |
| 722 | } |
| 723 | if (section->sh_size > limit) { |
| 724 | return false; |
| 725 | } |
| 726 | memcpy(buffer, elf + section->sh_offset, section->sh_size); |
| 727 | return elf64_apply_relocations(elf, file_size, hdr, buffer, section->sh_addr, section->sh_size, slide); |
| 728 | } |
| 729 | } |
| 730 | |
| 731 | return false; |
| 732 | } |
| 733 | |
| 734 | static uint64_t elf64_max_align(uint8_t *elf) { |
| 735 | uint64_t ret = 0; |
| 736 | |
| 737 | struct elf64_hdr *hdr = (void *)elf; |
| 738 | |
| 739 | if (hdr->phdr_size < sizeof(struct elf64_phdr)) { |
| 740 | panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)"); |
| 741 | } |
| 742 | |
| 743 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 744 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 745 | |
| 746 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) { |
| 747 | continue; |
| 748 | } |
| 749 | |
| 750 | if (phdr->p_align > 1 && (phdr->p_align & (phdr->p_align - 1)) != 0) { |
| 751 | panic(true, "elf: p_align is not a power of 2"); |
| 752 | } |
| 753 | |
| 754 | if (phdr->p_align > ret) { |
| 755 | ret = phdr->p_align; |
| 756 | } |
| 757 | } |
| 758 | |
| 759 | if (ret == 0) { |
| 760 | panic(true, "elf: Executable has no loadable segments"); |
| 761 | } |
| 762 | |
| 763 | return ret; |
| 764 | } |
| 765 | |
| 766 | static void elf64_get_ranges(uint8_t *elf, uint64_t slide, struct mem_range **_ranges, uint64_t *_ranges_count) { |
| 767 | struct elf64_hdr *hdr = (void *)elf; |
| 768 | |
| 769 | uint64_t ranges_count = 0; |
| 770 | |
| 771 | if (hdr->phdr_size < sizeof(struct elf64_phdr)) { |
| 772 | panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)"); |
| 773 | } |
| 774 | |
| 775 | bool is_reloc = elf64_is_relocatable(elf, hdr); |
| 776 | |
| 777 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 778 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 779 | |
| 780 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) { |
| 781 | continue; |
| 782 | } |
| 783 | |
| 784 | if (phdr->p_vaddr < FIXED_HIGHER_HALF_OFFSET_64) { |
| 785 | if (!is_reloc) { |
| 786 | continue; |
| 787 | } |
| 788 | } |
| 789 | |
| 790 | ranges_count++; |
| 791 | } |
| 792 | |
| 793 | if (ranges_count == 0) { |
| 794 | panic(true, "elf: No higher half PHDRs exist"); |
| 795 | } |
| 796 | |
| 797 | struct mem_range *ranges = ext_mem_alloc_counted(ranges_count, sizeof(struct mem_range)); |
| 798 | |
| 799 | size_t r = 0; |
| 800 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 801 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 802 | |
| 803 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) { |
| 804 | continue; |
| 805 | } |
| 806 | |
| 807 | if (phdr->p_vaddr < FIXED_HIGHER_HALF_OFFSET_64) { |
| 808 | if (!is_reloc) { |
| 809 | continue; |
| 810 | } |
| 811 | } |
| 812 | |
| 813 | uint64_t load_addr = phdr->p_vaddr + slide; |
| 814 | uint64_t this_top = load_addr + phdr->p_memsz; |
| 815 | |
| 816 | uint64_t align = phdr->p_align <= 1 ? 1 : phdr->p_align; |
| 817 | ranges[r].base = load_addr & ~(align - 1); |
| 818 | ranges[r].length = ALIGN_UP(this_top - ranges[r].base, align, panic(true, "elf: Alignment overflow")); |
| 819 | |
| 820 | if (phdr->p_flags & ELF_PF_X) { |
| 821 | ranges[r].permissions |= MEM_RANGE_X; |
| 822 | } |
| 823 | |
| 824 | if (phdr->p_flags & ELF_PF_W) { |
| 825 | ranges[r].permissions |= MEM_RANGE_W; |
| 826 | } |
| 827 | |
| 828 | if (phdr->p_flags & ELF_PF_R) { |
| 829 | ranges[r].permissions |= MEM_RANGE_R; |
| 830 | } |
| 831 | |
| 832 | r++; |
| 833 | } |
| 834 | |
| 835 | *_ranges_count = ranges_count; |
| 836 | *_ranges = ranges; |
| 837 | } |
| 838 | |
| 839 | bool elf64_load(uint8_t *elf, size_t file_size, uint64_t *entry_point, uint64_t *_slide, uint32_t alloc_type, bool kaslr, struct mem_range **ranges, uint64_t *ranges_count, uint64_t *physical_base, uint64_t *virtual_base, uint64_t *_image_size, uint64_t *_image_size_before_bss, bool *is_reloc) { |
| 840 | struct elf64_hdr *hdr = (void *)elf; |
| 841 | |
| 842 | elf64_validate(hdr); |
| 843 | |
| 844 | if (hdr->type != ET_EXEC && hdr->type != ET_DYN) { |
| 845 | panic(true, "elf: ELF file not of type ET_EXEC nor ET_DYN"); |
| 846 | } |
| 847 | |
| 848 | if (hdr->phdr_size < sizeof(struct elf64_phdr)) { |
| 849 | panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)"); |
| 850 | } |
| 851 | |
| 852 | uint64_t phdr_table_end = CHECKED_ADD( |
| 853 | CHECKED_MUL((uint64_t)hdr->ph_num, (uint64_t)hdr->phdr_size, |
| 854 | panic(true, "elf: Program header table size overflow")), |
| 855 | hdr->phoff, |
| 856 | panic(true, "elf: Program header table size overflow")); |
| 857 | |
| 858 | if (phdr_table_end > file_size) { |
| 859 | panic(true, "elf: Program header table extends beyond file bounds"); |
| 860 | } |
| 861 | |
| 862 | if (is_reloc) { |
| 863 | *is_reloc = false; |
| 864 | } |
| 865 | if (elf64_is_relocatable(elf, hdr)) { |
| 866 | if (is_reloc) { |
| 867 | *is_reloc = true; |
| 868 | } |
| 869 | } |
| 870 | |
| 871 | uint64_t slide = 0; |
| 872 | size_t try_count = 0; |
| 873 | size_t max_simulated_tries = 0x10000; |
| 874 | |
| 875 | uint64_t entry = hdr->entry; |
| 876 | |
| 877 | uint64_t max_align = elf64_max_align(elf); |
| 878 | |
| 879 | uint64_t image_size = 0; |
| 880 | |
| 881 | bool lower_to_higher = false; |
| 882 | |
| 883 | uint64_t min_vaddr = (uint64_t)-1; |
| 884 | uint64_t max_vaddr = 0; |
| 885 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 886 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 887 | |
| 888 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) { |
| 889 | continue; |
| 890 | } |
| 891 | |
| 892 | if (phdr->p_vaddr < FIXED_HIGHER_HALF_OFFSET_64) { |
| 893 | if (!is_reloc || !*is_reloc) { |
| 894 | panic(true, "elf: Lower half PHDRs are not allowed"); |
| 895 | } |
| 896 | lower_to_higher = true; |
| 897 | } else { |
| 898 | if (lower_to_higher) { |
| 899 | panic(true, "elf: Mix of lower and higher half PHDRs in relocatable kernel"); |
| 900 | } |
| 901 | } |
| 902 | |
| 903 | uint64_t phdr_end = CHECKED_ADD(phdr->p_vaddr, phdr->p_memsz, |
| 904 | panic(true, "elf: p_vaddr + p_memsz overflow in PHDR %u", i)); |
| 905 | |
| 906 | // check for overlapping phdrs |
| 907 | for (uint16_t j = 0; j < hdr->ph_num; j++) { |
| 908 | struct elf64_phdr *phdr_in = (void *)elf + (hdr->phoff + j * hdr->phdr_size); |
| 909 | |
| 910 | if (phdr_in->p_type != PT_LOAD || phdr_in->p_memsz == 0) { |
| 911 | continue; |
| 912 | } |
| 913 | |
| 914 | if (phdr_in->p_vaddr < FIXED_HIGHER_HALF_OFFSET_64) { |
| 915 | if (!is_reloc || !*is_reloc) { |
| 916 | continue; |
| 917 | } |
| 918 | } |
| 919 | |
| 920 | if (phdr_in == phdr) { |
| 921 | continue; |
| 922 | } |
| 923 | |
| 924 | uint64_t phdr_in_end = CHECKED_ADD(phdr_in->p_vaddr, phdr_in->p_memsz, |
| 925 | panic(true, "elf: p_vaddr + p_memsz overflow in PHDR %u", j)); |
| 926 | |
| 927 | if ((phdr_in->p_vaddr >= phdr->p_vaddr |
| 928 | && phdr_in->p_vaddr < phdr_end) |
| 929 | || |
| 930 | (phdr_in_end > phdr->p_vaddr |
| 931 | && phdr_in_end <= phdr_end)) { |
| 932 | panic(true, "elf: Attempted to load ELF file with overlapping PHDRs (%u and %u overlap)", i, j); |
| 933 | } |
| 934 | |
| 935 | if (ranges != NULL) { |
| 936 | uint64_t page_rounded_base = ALIGN_DOWN(phdr->p_vaddr, 4096); |
| 937 | uint64_t page_rounded_top = ALIGN_UP(phdr_end, 4096, panic(true, "elf: PHDR alignment overflow")); |
| 938 | uint64_t page_rounded_base_in = ALIGN_DOWN(phdr_in->p_vaddr, 4096); |
| 939 | uint64_t page_rounded_top_in = ALIGN_UP(phdr_in_end, 4096, panic(true, "elf: PHDR alignment overflow")); |
| 940 | |
| 941 | if ((page_rounded_base >= page_rounded_base_in |
| 942 | && page_rounded_base < page_rounded_top_in) |
| 943 | || |
| 944 | (page_rounded_top > page_rounded_base_in |
| 945 | && page_rounded_top <= page_rounded_top_in)) { |
| 946 | if ((phdr->p_flags & 0b111) != (phdr_in->p_flags & 0b111)) { |
| 947 | panic(true, "elf: Attempted to load ELF file with PHDRs with different permissions sharing the same memory page."); |
| 948 | } |
| 949 | } |
| 950 | } |
| 951 | } |
| 952 | |
| 953 | if (phdr->p_vaddr < min_vaddr) { |
| 954 | min_vaddr = phdr->p_vaddr; |
| 955 | } |
| 956 | |
| 957 | if (phdr_end > max_vaddr) { |
| 958 | max_vaddr = phdr_end; |
| 959 | } |
| 960 | } |
| 961 | |
| 962 | if (min_vaddr == (uint64_t)-1) { |
| 963 | panic(true, "elf: No usable PHDRs exist"); |
| 964 | } |
| 965 | |
| 966 | if (lower_to_higher) { |
| 967 | slide = FIXED_HIGHER_HALF_OFFSET_64 - min_vaddr; |
| 968 | } |
| 969 | |
| 970 | image_size = max_vaddr - min_vaddr; |
| 971 | |
| 972 | *physical_base = (uintptr_t)ext_mem_alloc_type_aligned(image_size, alloc_type, max_align); |
| 973 | *virtual_base = min_vaddr; |
| 974 | |
| 975 | if (_image_size) { |
| 976 | *_image_size = image_size; |
| 977 | } |
| 978 | |
| 979 | again: |
| 980 | if (is_reloc && *is_reloc && kaslr) { |
| 981 | slide = (rand32() & ~(max_align - 1)) + (lower_to_higher ? FIXED_HIGHER_HALF_OFFSET_64 - min_vaddr : 0); |
| 982 | |
| 983 | if (*virtual_base + slide + image_size < 0xffffffff80000000 /* this comparison relies on overflow */) { |
| 984 | if (++try_count == max_simulated_tries) { |
| 985 | panic(true, "elf: Image wants to load too high"); |
| 986 | } |
| 987 | goto again; |
| 988 | } |
| 989 | } |
| 990 | |
| 991 | uint64_t bss_size = 0; |
| 992 | |
| 993 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 994 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 995 | |
| 996 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) { |
| 997 | continue; |
| 998 | } |
| 999 | |
| 1000 | // Sanity checks |
| 1001 | if (phdr->p_filesz > phdr->p_memsz) { |
| 1002 | panic(true, "elf: p_filesz > p_memsz"); |
| 1003 | } |
| 1004 | |
| 1005 | // Validate p_offset + p_filesz doesn't overflow or exceed file size |
| 1006 | uint64_t offset_end = CHECKED_ADD(phdr->p_offset, phdr->p_filesz, |
| 1007 | panic(true, "elf: p_offset + p_filesz overflow")); |
| 1008 | if (offset_end > file_size) { |
| 1009 | panic(true, "elf: p_offset + p_filesz exceeds file size"); |
| 1010 | } |
| 1011 | |
| 1012 | uint64_t load_addr = *physical_base + (phdr->p_vaddr - *virtual_base); |
| 1013 | |
| 1014 | #if defined (__aarch64__) |
| 1015 | uint64_t this_top = CHECKED_ADD(load_addr, phdr->p_memsz, |
| 1016 | panic(true, "elf: load_addr + p_memsz overflow")); |
| 1017 | |
| 1018 | uint64_t mem_base, mem_size; |
| 1019 | |
| 1020 | uint64_t align = phdr->p_align <= 1 ? 1 : phdr->p_align; |
| 1021 | mem_base = load_addr & ~(align - 1); |
| 1022 | mem_size = this_top - mem_base; |
| 1023 | #endif |
| 1024 | |
| 1025 | memcpy((void *)(uintptr_t)load_addr, elf + (phdr->p_offset), phdr->p_filesz); |
| 1026 | |
| 1027 | if (phdr->p_vaddr + phdr->p_memsz == max_vaddr) { |
| 1028 | bss_size = phdr->p_memsz - phdr->p_filesz; |
| 1029 | } |
| 1030 | |
| 1031 | if (!elf64_apply_relocations(elf, file_size, hdr, (void *)(uintptr_t)load_addr, phdr->p_vaddr, phdr->p_memsz, slide)) { |
| 1032 | panic(true, "elf: Failed to apply relocations"); |
| 1033 | } |
| 1034 | |
| 1035 | #if defined (__aarch64__) |
| 1036 | clean_dcache_poc(mem_base, mem_base + mem_size); |
| 1037 | inval_icache_pou(mem_base, mem_base + mem_size); |
| 1038 | #endif |
| 1039 | } |
| 1040 | |
| 1041 | if (_image_size_before_bss != NULL) { |
| 1042 | *_image_size_before_bss = image_size - bss_size; |
| 1043 | } |
| 1044 | |
| 1045 | *virtual_base += slide; |
| 1046 | *entry_point = entry + slide; |
| 1047 | if (_slide) { |
| 1048 | *_slide = slide; |
| 1049 | } |
| 1050 | |
| 1051 | if (ranges_count != NULL && ranges != NULL) { |
| 1052 | elf64_get_ranges(elf, slide, ranges, ranges_count); |
| 1053 | } |
| 1054 | |
| 1055 | return true; |
| 1056 | } |
| 1057 | |
| 1058 | bool elf32_load_elsewhere(uint8_t *elf, size_t file_size, uint64_t *entry_point, |
| 1059 | struct elsewhere_range **ranges) { |
| 1060 | struct elf32_hdr *hdr = (void *)elf; |
| 1061 | |
| 1062 | elf32_validate(hdr); |
| 1063 | |
| 1064 | if (hdr->type != ET_EXEC && hdr->type != ET_DYN) { |
| 1065 | panic(true, "elf: ELF file not of type ET_EXEC nor ET_DYN"); |
| 1066 | } |
| 1067 | |
| 1068 | *entry_point = hdr->entry; |
| 1069 | bool entry_adjusted = false; |
| 1070 | |
| 1071 | if (hdr->phdr_size < sizeof(struct elf32_phdr)) { |
| 1072 | panic(true, "elf: phdr_size < sizeof(struct elf32_phdr)"); |
| 1073 | } |
| 1074 | |
| 1075 | uint64_t phdr_table_size32 = (uint64_t)hdr->ph_num * hdr->phdr_size; |
| 1076 | if (hdr->phoff > file_size || phdr_table_size32 > file_size - hdr->phoff) { |
| 1077 | panic(true, "elf: Program header table extends beyond file bounds"); |
| 1078 | } |
| 1079 | |
| 1080 | uint64_t min_paddr = (uint64_t)-1; |
| 1081 | uint64_t max_paddr = 0; |
| 1082 | bool has_loadable = false; |
| 1083 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 1084 | struct elf32_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 1085 | |
| 1086 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) |
| 1087 | continue; |
| 1088 | |
| 1089 | has_loadable = true; |
| 1090 | |
| 1091 | if (phdr->p_paddr < min_paddr) { |
| 1092 | min_paddr = phdr->p_paddr; |
| 1093 | } |
| 1094 | |
| 1095 | uint64_t top = CHECKED_ADD((uint64_t)phdr->p_paddr, phdr->p_memsz, |
| 1096 | panic(true, "elf: p_paddr + p_memsz overflow")); |
| 1097 | if (top > max_paddr) { |
| 1098 | max_paddr = top; |
| 1099 | } |
| 1100 | } |
| 1101 | if (!has_loadable) { |
| 1102 | panic(true, "elf: No loadable segments"); |
| 1103 | } |
| 1104 | uint64_t image_size_64 = max_paddr - min_paddr; |
| 1105 | if (image_size_64 > SIZE_MAX) { |
| 1106 | panic(true, "elf: Image size exceeds address space"); |
| 1107 | } |
| 1108 | size_t image_size = (size_t)image_size_64; |
| 1109 | |
| 1110 | void *elsewhere = ext_mem_alloc(image_size); |
| 1111 | |
| 1112 | *ranges = ext_mem_alloc(sizeof(struct elsewhere_range)); |
| 1113 | |
| 1114 | (*ranges)->elsewhere = (uintptr_t)elsewhere; |
| 1115 | (*ranges)->target = min_paddr; |
| 1116 | (*ranges)->length = image_size; |
| 1117 | |
| 1118 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 1119 | struct elf32_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 1120 | |
| 1121 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) |
| 1122 | continue; |
| 1123 | |
| 1124 | // Sanity checks |
| 1125 | if (phdr->p_filesz > phdr->p_memsz) { |
| 1126 | panic(true, "elf: p_filesz > p_memsz"); |
| 1127 | } |
| 1128 | uint64_t offset_end = CHECKED_ADD((uint64_t)phdr->p_offset, phdr->p_filesz, |
| 1129 | panic(true, "elf: p_offset + p_filesz overflow")); |
| 1130 | if (offset_end > file_size) { |
| 1131 | panic(true, "elf: p_offset + p_filesz exceeds file size"); |
| 1132 | } |
| 1133 | |
| 1134 | memcpy(elsewhere + (phdr->p_paddr - min_paddr), elf + phdr->p_offset, phdr->p_filesz); |
| 1135 | |
| 1136 | if (!entry_adjusted |
| 1137 | && *entry_point >= phdr->p_vaddr |
| 1138 | && *entry_point < CHECKED_ADD(phdr->p_vaddr, phdr->p_memsz, continue)) { |
| 1139 | *entry_point -= phdr->p_vaddr; |
| 1140 | *entry_point += phdr->p_paddr; |
| 1141 | entry_adjusted = true; |
| 1142 | } |
| 1143 | } |
| 1144 | |
| 1145 | return true; |
| 1146 | } |
| 1147 | |
| 1148 | bool elf64_load_elsewhere(uint8_t *elf, size_t file_size, uint64_t *entry_point, |
| 1149 | struct elsewhere_range **ranges) { |
| 1150 | struct elf64_hdr *hdr = (void *)elf; |
| 1151 | |
| 1152 | elf64_validate(hdr); |
| 1153 | |
| 1154 | if (hdr->type != ET_EXEC && hdr->type != ET_DYN) { |
| 1155 | panic(true, "elf: ELF file not of type ET_EXEC nor ET_DYN"); |
| 1156 | } |
| 1157 | |
| 1158 | *entry_point = hdr->entry; |
| 1159 | bool entry_adjusted = false; |
| 1160 | |
| 1161 | if (hdr->phdr_size < sizeof(struct elf64_phdr)) { |
| 1162 | panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)"); |
| 1163 | } |
| 1164 | |
| 1165 | uint64_t phdr_table_size64 = (uint64_t)hdr->ph_num * hdr->phdr_size; |
| 1166 | if (hdr->phoff > file_size || phdr_table_size64 > file_size - hdr->phoff) { |
| 1167 | panic(true, "elf: Program header table extends beyond file bounds"); |
| 1168 | } |
| 1169 | |
| 1170 | uint64_t min_paddr = (uint64_t)-1; |
| 1171 | uint64_t max_paddr = 0; |
| 1172 | bool has_loadable = false; |
| 1173 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 1174 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 1175 | |
| 1176 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) |
| 1177 | continue; |
| 1178 | |
| 1179 | has_loadable = true; |
| 1180 | |
| 1181 | if (phdr->p_paddr < min_paddr) { |
| 1182 | min_paddr = phdr->p_paddr; |
| 1183 | } |
| 1184 | |
| 1185 | uint64_t top = CHECKED_ADD(phdr->p_paddr, phdr->p_memsz, |
| 1186 | panic(true, "elf: p_paddr + p_memsz overflow")); |
| 1187 | if (top > max_paddr) { |
| 1188 | max_paddr = top; |
| 1189 | } |
| 1190 | } |
| 1191 | if (!has_loadable) { |
| 1192 | panic(true, "elf: No loadable segments"); |
| 1193 | } |
| 1194 | uint64_t image_size = max_paddr - min_paddr; |
| 1195 | if (image_size > SIZE_MAX) { |
| 1196 | panic(true, "elf: Image size exceeds address space"); |
| 1197 | } |
| 1198 | |
| 1199 | void *elsewhere = ext_mem_alloc(image_size); |
| 1200 | |
| 1201 | *ranges = ext_mem_alloc(sizeof(struct elsewhere_range)); |
| 1202 | |
| 1203 | (*ranges)->elsewhere = (uintptr_t)elsewhere; |
| 1204 | (*ranges)->target = min_paddr; |
| 1205 | (*ranges)->length = image_size; |
| 1206 | |
| 1207 | for (uint16_t i = 0; i < hdr->ph_num; i++) { |
| 1208 | struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size); |
| 1209 | |
| 1210 | if (phdr->p_type != PT_LOAD || phdr->p_memsz == 0) |
| 1211 | continue; |
| 1212 | |
| 1213 | // Sanity checks |
| 1214 | if (phdr->p_filesz > phdr->p_memsz) { |
| 1215 | panic(true, "elf: p_filesz > p_memsz"); |
| 1216 | } |
| 1217 | uint64_t offset_end = CHECKED_ADD(phdr->p_offset, phdr->p_filesz, |
| 1218 | panic(true, "elf: p_offset + p_filesz overflow")); |
| 1219 | if (offset_end > file_size) { |
| 1220 | panic(true, "elf: p_offset + p_filesz exceeds file size"); |
| 1221 | } |
| 1222 | |
| 1223 | memcpy(elsewhere + (phdr->p_paddr - min_paddr), elf + phdr->p_offset, phdr->p_filesz); |
| 1224 | |
| 1225 | if (!entry_adjusted |
| 1226 | && *entry_point >= phdr->p_vaddr |
| 1227 | && *entry_point < CHECKED_ADD(phdr->p_vaddr, phdr->p_memsz, continue)) { |
| 1228 | *entry_point -= phdr->p_vaddr; |
| 1229 | *entry_point += phdr->p_paddr; |
| 1230 | entry_adjusted = true; |
| 1231 | } |
| 1232 | } |
| 1233 | |
| 1234 | return true; |
| 1235 | } |
