1 /*- 2 * Copyright (c) 2004 Ian Dowse <iedowse@freebsd.org> 3 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 4 * Copyright (c) 1998 Peter Wemm <peter@freebsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/param.h> 30 #include <sys/exec.h> 31 #include <sys/linker.h> 32 #include <sys/module.h> 33 #include <stdint.h> 34 #include <string.h> 35 #include <machine/elf.h> 36 #include <stand.h> 37 #include <sys/link_elf.h> 38 39 #include "bootstrap.h" 40 41 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l) 42 43 #if defined(__i386__) && __ELF_WORD_SIZE == 64 44 #undef ELF_TARG_CLASS 45 #undef ELF_TARG_MACH 46 #define ELF_TARG_CLASS ELFCLASS64 47 #define ELF_TARG_MACH EM_X86_64 48 #endif 49 50 typedef struct elf_file { 51 Elf_Ehdr hdr; 52 Elf_Shdr *e_shdr; 53 54 int symtabindex; /* Index of symbol table */ 55 int shstrindex; /* Index of section name string table */ 56 57 int fd; 58 vm_offset_t off; 59 #ifdef LOADER_VERIEXEC_VECTX 60 struct vectx *vctx; 61 #endif 62 } *elf_file_t; 63 64 #ifdef LOADER_VERIEXEC_VECTX 65 #define VECTX_HANDLE(ef) (ef)->vctx 66 #else 67 #define VECTX_HANDLE(ef) (ef)->fd 68 #endif 69 70 static int __elfN(obj_loadimage)(struct preloaded_file *mp, elf_file_t ef, 71 uint64_t loadaddr); 72 static int __elfN(obj_lookup_set)(struct preloaded_file *mp, elf_file_t ef, 73 const char *name, Elf_Addr *startp, Elf_Addr *stopp, int *countp); 74 static int __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, 75 Elf_Addr p, void *val, size_t len); 76 static int __elfN(obj_parse_modmetadata)(struct preloaded_file *mp, 77 elf_file_t ef); 78 static Elf_Addr __elfN(obj_symaddr)(struct elf_file *ef, Elf_Size symidx); 79 80 const char *__elfN(obj_kerneltype) = "elf kernel"; 81 const char *__elfN(obj_moduletype) = "elf obj module"; 82 83 /* 84 * Attempt to load the file (file) as an ELF module. It will be stored at 85 * (dest), and a pointer to a module structure describing the loaded object 86 * will be saved in (result). 87 */ 88 int 89 __elfN(obj_loadfile)(char *filename, uint64_t dest, 90 struct preloaded_file **result) 91 { 92 struct preloaded_file *fp, *kfp; 93 struct elf_file ef; 94 Elf_Ehdr *hdr; 95 int err; 96 ssize_t bytes_read; 97 98 fp = NULL; 99 bzero(&ef, sizeof(struct elf_file)); 100 101 /* 102 * Open the image, read and validate the ELF header 103 */ 104 if (filename == NULL) /* can't handle nameless */ 105 return(EFTYPE); 106 if ((ef.fd = open(filename, O_RDONLY)) == -1) 107 return(errno); 108 #ifdef LOADER_VERIEXEC_VECTX 109 { 110 int verror; 111 112 ef.vctx = vectx_open(ef.fd, filename, 0L, NULL, &verror, __func__); 113 if (verror) { 114 printf("Unverified %s: %s\n", filename, ve_error_get()); 115 close(ef.fd); 116 free(ef.vctx); 117 return (EAUTH); 118 } 119 } 120 #endif 121 122 hdr = &ef.hdr; 123 bytes_read = VECTX_READ(VECTX_HANDLE(&ef), hdr, sizeof(*hdr)); 124 if (bytes_read != sizeof(*hdr)) { 125 err = EFTYPE; /* could be EIO, but may be small file */ 126 goto oerr; 127 } 128 129 /* Is it ELF? */ 130 if (!IS_ELF(*hdr)) { 131 err = EFTYPE; 132 goto oerr; 133 } 134 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */ 135 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 136 hdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */ 137 hdr->e_version != EV_CURRENT || 138 hdr->e_machine != ELF_TARG_MACH || /* Machine ? */ 139 hdr->e_type != ET_REL) { 140 err = EFTYPE; 141 goto oerr; 142 } 143 144 if (hdr->e_shnum * hdr->e_shentsize == 0 || hdr->e_shoff == 0 || 145 hdr->e_shentsize != sizeof(Elf_Shdr)) { 146 err = EFTYPE; 147 goto oerr; 148 } 149 150 #if defined(LOADER_VERIEXEC) && !defined(LOADER_VERIEXEC_VECTX) 151 if (verify_file(ef.fd, filename, bytes_read, VE_MUST, __func__) < 0) { 152 err = EAUTH; 153 goto oerr; 154 } 155 #endif 156 157 kfp = file_findfile(NULL, __elfN(obj_kerneltype)); 158 if (kfp == NULL) { 159 printf("elf" __XSTRING(__ELF_WORD_SIZE) 160 "_obj_loadfile: can't load module before kernel\n"); 161 err = EPERM; 162 goto oerr; 163 } 164 165 if (archsw.arch_loadaddr != NULL) 166 dest = archsw.arch_loadaddr(LOAD_ELF, hdr, dest); 167 else 168 dest = roundup(dest, PAGE_SIZE); 169 170 /* 171 * Ok, we think we should handle this. 172 */ 173 fp = file_alloc(); 174 if (fp == NULL) { 175 printf("elf" __XSTRING(__ELF_WORD_SIZE) 176 "_obj_loadfile: cannot allocate module info\n"); 177 err = EPERM; 178 goto out; 179 } 180 fp->f_name = strdup(filename); 181 fp->f_type = strdup(__elfN(obj_moduletype)); 182 183 if (module_verbose > MODULE_VERBOSE_SILENT) 184 printf("%s ", filename); 185 186 fp->f_size = __elfN(obj_loadimage)(fp, &ef, dest); 187 if (fp->f_size == 0 || fp->f_addr == 0) 188 goto ioerr; 189 190 /* save exec header as metadata */ 191 file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*hdr), hdr); 192 193 /* Load OK, return module pointer */ 194 *result = (struct preloaded_file *)fp; 195 err = 0; 196 goto out; 197 198 ioerr: 199 err = EIO; 200 oerr: 201 file_discard(fp); 202 out: 203 #ifdef LOADER_VERIEXEC_VECTX 204 if (!err && ef.vctx) { 205 int verror; 206 207 verror = vectx_close(ef.vctx, VE_MUST, __func__); 208 if (verror) { 209 err = EAUTH; 210 file_discard(fp); 211 } 212 } 213 #endif 214 close(ef.fd); 215 if (ef.e_shdr != NULL) 216 free(ef.e_shdr); 217 218 return(err); 219 } 220 221 /* 222 * With the file (fd) open on the image, and (ehdr) containing 223 * the Elf header, load the image at (off) 224 */ 225 static int 226 __elfN(obj_loadimage)(struct preloaded_file *fp, elf_file_t ef, uint64_t off) 227 { 228 Elf_Ehdr *hdr; 229 Elf_Shdr *shdr, *cshdr, *lshdr; 230 vm_offset_t firstaddr, lastaddr; 231 int i, nsym, res, ret, shdrbytes, symstrindex; 232 233 ret = 0; 234 firstaddr = lastaddr = (vm_offset_t)off; 235 hdr = &ef->hdr; 236 ef->off = (vm_offset_t)off; 237 238 /* Read in the section headers. */ 239 shdrbytes = hdr->e_shnum * hdr->e_shentsize; 240 shdr = alloc_pread(VECTX_HANDLE(ef), (off_t)hdr->e_shoff, shdrbytes); 241 if (shdr == NULL) { 242 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 243 "_obj_loadimage: read section headers failed\n"); 244 goto out; 245 } 246 ef->e_shdr = shdr; 247 248 /* 249 * Decide where to load everything, but don't read it yet. 250 * We store the load address as a non-zero sh_addr value. 251 * Start with the code/data and bss. 252 */ 253 for (i = 0; i < hdr->e_shnum; i++) 254 shdr[i].sh_addr = 0; 255 for (i = 0; i < hdr->e_shnum; i++) { 256 if (shdr[i].sh_size == 0) 257 continue; 258 switch (shdr[i].sh_type) { 259 case SHT_PROGBITS: 260 case SHT_NOBITS: 261 #if defined(__i386__) || defined(__amd64__) 262 case SHT_X86_64_UNWIND: 263 #endif 264 case SHT_INIT_ARRAY: 265 case SHT_FINI_ARRAY: 266 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 267 break; 268 lastaddr = roundup(lastaddr, shdr[i].sh_addralign); 269 shdr[i].sh_addr = (Elf_Addr)lastaddr; 270 lastaddr += shdr[i].sh_size; 271 break; 272 } 273 } 274 275 /* Symbols. */ 276 nsym = 0; 277 for (i = 0; i < hdr->e_shnum; i++) { 278 switch (shdr[i].sh_type) { 279 case SHT_SYMTAB: 280 nsym++; 281 ef->symtabindex = i; 282 break; 283 } 284 } 285 if (nsym != 1) { 286 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 287 "_obj_loadimage: file has no valid symbol table\n"); 288 goto out; 289 } 290 lastaddr = roundup(lastaddr, shdr[ef->symtabindex].sh_addralign); 291 shdr[ef->symtabindex].sh_addr = (Elf_Addr)lastaddr; 292 lastaddr += shdr[ef->symtabindex].sh_size; 293 294 symstrindex = shdr[ef->symtabindex].sh_link; 295 if (symstrindex < 0 || symstrindex >= hdr->e_shnum || 296 shdr[symstrindex].sh_type != SHT_STRTAB) { 297 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 298 "_obj_loadimage: file has invalid symbol strings\n"); 299 goto out; 300 } 301 lastaddr = roundup(lastaddr, shdr[symstrindex].sh_addralign); 302 shdr[symstrindex].sh_addr = (Elf_Addr)lastaddr; 303 lastaddr += shdr[symstrindex].sh_size; 304 305 /* Section names. */ 306 if (hdr->e_shstrndx == 0 || hdr->e_shstrndx >= hdr->e_shnum || 307 shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) { 308 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 309 "_obj_loadimage: file has no section names\n"); 310 goto out; 311 } 312 ef->shstrindex = hdr->e_shstrndx; 313 lastaddr = roundup(lastaddr, shdr[ef->shstrindex].sh_addralign); 314 shdr[ef->shstrindex].sh_addr = (Elf_Addr)lastaddr; 315 lastaddr += shdr[ef->shstrindex].sh_size; 316 317 /* Relocation tables. */ 318 for (i = 0; i < hdr->e_shnum; i++) { 319 switch (shdr[i].sh_type) { 320 case SHT_REL: 321 case SHT_RELA: 322 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 323 break; 324 lastaddr = roundup(lastaddr, shdr[i].sh_addralign); 325 shdr[i].sh_addr = (Elf_Addr)lastaddr; 326 lastaddr += shdr[i].sh_size; 327 break; 328 } 329 } 330 331 /* Clear the whole area, including bss regions. */ 332 kern_bzero(firstaddr, lastaddr - firstaddr); 333 334 /* Figure section with the lowest file offset we haven't loaded yet. */ 335 for (cshdr = NULL; /* none */; /* none */) 336 { 337 /* 338 * Find next section to load. The complexity of this loop is 339 * O(n^2), but with the number of sections being typically 340 * small, we do not care. 341 */ 342 lshdr = cshdr; 343 344 for (i = 0; i < hdr->e_shnum; i++) { 345 if (shdr[i].sh_addr == 0 || 346 shdr[i].sh_type == SHT_NOBITS) 347 continue; 348 /* Skip sections that were loaded already. */ 349 if (lshdr != NULL && 350 lshdr->sh_offset >= shdr[i].sh_offset) 351 continue; 352 /* Find section with smallest offset. */ 353 if (cshdr == lshdr || 354 cshdr->sh_offset > shdr[i].sh_offset) 355 cshdr = &shdr[i]; 356 } 357 358 if (cshdr == lshdr) 359 break; 360 361 if (kern_pread(VECTX_HANDLE(ef), (vm_offset_t)cshdr->sh_addr, 362 cshdr->sh_size, (off_t)cshdr->sh_offset) != 0) { 363 printf("\nelf" __XSTRING(__ELF_WORD_SIZE) 364 "_obj_loadimage: read failed\n"); 365 goto out; 366 } 367 } 368 369 file_addmetadata(fp, MODINFOMD_SHDR, shdrbytes, shdr); 370 371 res = __elfN(obj_parse_modmetadata)(fp, ef); 372 if (res != 0) 373 goto out; 374 375 ret = lastaddr - firstaddr; 376 fp->f_addr = firstaddr; 377 378 if (module_verbose > MODULE_VERBOSE_SILENT) 379 printf("size 0x%lx at 0x%lx", (u_long)ret, (u_long)firstaddr); 380 381 out: 382 if (module_verbose > MODULE_VERBOSE_SILENT) 383 printf("\n"); 384 return ret; 385 } 386 387 #if defined(__i386__) && __ELF_WORD_SIZE == 64 388 struct mod_metadata64 { 389 int md_version; /* structure version MDTV_* */ 390 int md_type; /* type of entry MDT_* */ 391 uint64_t md_data; /* specific data */ 392 uint64_t md_cval; /* common string label */ 393 }; 394 #endif 395 396 int 397 __elfN(obj_parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef) 398 { 399 struct mod_metadata md; 400 #if defined(__i386__) && __ELF_WORD_SIZE == 64 401 struct mod_metadata64 md64; 402 #endif 403 struct mod_depend *mdepend; 404 struct mod_version mver; 405 char *s; 406 int error, modcnt, minfolen; 407 Elf_Addr v, p, p_stop; 408 409 if (__elfN(obj_lookup_set)(fp, ef, "modmetadata_set", &p, &p_stop, 410 &modcnt) != 0) 411 return 0; 412 413 modcnt = 0; 414 while (p < p_stop) { 415 COPYOUT(p, &v, sizeof(v)); 416 error = __elfN(obj_reloc_ptr)(fp, ef, p, &v, sizeof(v)); 417 if (error != 0) 418 return (error); 419 #if defined(__i386__) && __ELF_WORD_SIZE == 64 420 COPYOUT(v, &md64, sizeof(md64)); 421 error = __elfN(obj_reloc_ptr)(fp, ef, v, &md64, sizeof(md64)); 422 if (error != 0) 423 return (error); 424 md.md_version = md64.md_version; 425 md.md_type = md64.md_type; 426 md.md_cval = (const char *)(uintptr_t)md64.md_cval; 427 md.md_data = (void *)(uintptr_t)md64.md_data; 428 #else 429 COPYOUT(v, &md, sizeof(md)); 430 error = __elfN(obj_reloc_ptr)(fp, ef, v, &md, sizeof(md)); 431 if (error != 0) 432 return (error); 433 #endif 434 p += sizeof(Elf_Addr); 435 switch(md.md_type) { 436 case MDT_DEPEND: 437 s = strdupout((vm_offset_t)md.md_cval); 438 minfolen = sizeof(*mdepend) + strlen(s) + 1; 439 mdepend = malloc(minfolen); 440 if (mdepend == NULL) 441 return ENOMEM; 442 COPYOUT((vm_offset_t)md.md_data, mdepend, 443 sizeof(*mdepend)); 444 strcpy((char*)(mdepend + 1), s); 445 free(s); 446 file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, 447 mdepend); 448 free(mdepend); 449 break; 450 case MDT_VERSION: 451 s = strdupout((vm_offset_t)md.md_cval); 452 COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver)); 453 file_addmodule(fp, s, mver.mv_version, NULL); 454 free(s); 455 modcnt++; 456 break; 457 case MDT_MODULE: 458 case MDT_PNP_INFO: 459 break; 460 default: 461 printf("unknown type %d\n", md.md_type); 462 break; 463 } 464 } 465 return 0; 466 } 467 468 static int 469 __elfN(obj_lookup_set)(struct preloaded_file *fp, elf_file_t ef, 470 const char* name, Elf_Addr *startp, Elf_Addr *stopp, int *countp) 471 { 472 Elf_Ehdr *hdr; 473 Elf_Shdr *shdr; 474 char *p; 475 vm_offset_t shstrtab; 476 int i; 477 478 hdr = &ef->hdr; 479 shdr = ef->e_shdr; 480 shstrtab = shdr[ef->shstrindex].sh_addr; 481 482 for (i = 0; i < hdr->e_shnum; i++) { 483 if (shdr[i].sh_type != SHT_PROGBITS) 484 continue; 485 if (shdr[i].sh_name == 0) 486 continue; 487 p = strdupout(shstrtab + shdr[i].sh_name); 488 if (strncmp(p, "set_", 4) == 0 && strcmp(p + 4, name) == 0) { 489 *startp = shdr[i].sh_addr; 490 *stopp = shdr[i].sh_addr + shdr[i].sh_size; 491 *countp = (*stopp - *startp) / sizeof(Elf_Addr); 492 free(p); 493 return (0); 494 } 495 free(p); 496 } 497 498 return (ESRCH); 499 } 500 501 /* 502 * Apply any intra-module relocations to the value. p is the load address 503 * of the value and val/len is the value to be modified. This does NOT modify 504 * the image in-place, because this is done by kern_linker later on. 505 */ 506 static int 507 __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, Elf_Addr p, 508 void *val, size_t len) 509 { 510 Elf_Ehdr *hdr; 511 Elf_Shdr *shdr; 512 Elf_Addr off = p; 513 Elf_Addr base; 514 Elf_Rela a, *abase; 515 Elf_Rel r, *rbase; 516 int error, i, j, nrel, nrela; 517 518 hdr = &ef->hdr; 519 shdr = ef->e_shdr; 520 521 for (i = 0; i < hdr->e_shnum; i++) { 522 if (shdr[i].sh_type != SHT_RELA && shdr[i].sh_type != SHT_REL) 523 continue; 524 base = shdr[shdr[i].sh_info].sh_addr; 525 if (base == 0 || shdr[i].sh_addr == 0) 526 continue; 527 if (off < base || off + len > base + 528 shdr[shdr[i].sh_info].sh_size) 529 continue; 530 531 switch (shdr[i].sh_type) { 532 case SHT_RELA: 533 abase = (Elf_Rela *)(intptr_t)shdr[i].sh_addr; 534 535 nrela = shdr[i].sh_size / sizeof(Elf_Rela); 536 for (j = 0; j < nrela; j++) { 537 COPYOUT(abase + j, &a, sizeof(a)); 538 539 error = __elfN(reloc)(ef, __elfN(obj_symaddr), 540 &a, ELF_RELOC_RELA, base, off, val, len); 541 if (error != 0) 542 return (error); 543 } 544 break; 545 case SHT_REL: 546 rbase = (Elf_Rel *)(intptr_t)shdr[i].sh_addr; 547 548 nrel = shdr[i].sh_size / sizeof(Elf_Rel); 549 for (j = 0; j < nrel; j++) { 550 COPYOUT(rbase + j, &r, sizeof(r)); 551 552 error = __elfN(reloc)(ef, __elfN(obj_symaddr), 553 &r, ELF_RELOC_REL, base, off, val, len); 554 if (error != 0) 555 return (error); 556 } 557 break; 558 } 559 } 560 return (0); 561 } 562 563 /* Look up the address of a specified symbol. */ 564 static Elf_Addr 565 __elfN(obj_symaddr)(struct elf_file *ef, Elf_Size symidx) 566 { 567 Elf_Sym sym; 568 Elf_Addr base; 569 570 if (symidx >= ef->e_shdr[ef->symtabindex].sh_size / sizeof(Elf_Sym)) 571 return (0); 572 COPYOUT(ef->e_shdr[ef->symtabindex].sh_addr + symidx * sizeof(Elf_Sym), 573 &sym, sizeof(sym)); 574 if (sym.st_shndx == SHN_UNDEF || sym.st_shndx >= ef->hdr.e_shnum) 575 return (0); 576 base = ef->e_shdr[sym.st_shndx].sh_addr; 577 if (base == 0) 578 return (0); 579 return (base + sym.st_value); 580 } 581