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