1 /*- 2 * Copyright (c) 1998-2000 Doug Rabson 3 * Copyright (c) 2004 Peter Wemm 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "opt_ddb.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/mutex.h> 39 #include <sys/mount.h> 40 #include <sys/proc.h> 41 #include <sys/namei.h> 42 #include <sys/fcntl.h> 43 #include <sys/vnode.h> 44 #include <sys/linker.h> 45 46 #include <machine/elf.h> 47 48 #include <net/vnet.h> 49 50 #include <security/mac/mac_framework.h> 51 52 #include <vm/vm.h> 53 #include <vm/vm_param.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_kern.h> 56 #include <vm/vm_extern.h> 57 #include <vm/pmap.h> 58 #include <vm/vm_map.h> 59 60 #include <sys/link_elf.h> 61 62 #ifdef DDB_CTF 63 #include <sys/zlib.h> 64 #endif 65 66 #include "linker_if.h" 67 68 typedef struct { 69 void *addr; 70 Elf_Off size; 71 int flags; 72 int sec; /* Original section */ 73 char *name; 74 } Elf_progent; 75 76 typedef struct { 77 Elf_Rel *rel; 78 int nrel; 79 int sec; 80 } Elf_relent; 81 82 typedef struct { 83 Elf_Rela *rela; 84 int nrela; 85 int sec; 86 } Elf_relaent; 87 88 89 typedef struct elf_file { 90 struct linker_file lf; /* Common fields */ 91 92 int preloaded; 93 caddr_t address; /* Relocation address */ 94 vm_object_t object; /* VM object to hold file pages */ 95 Elf_Shdr *e_shdr; 96 97 Elf_progent *progtab; 98 int nprogtab; 99 100 Elf_relaent *relatab; 101 int nrelatab; 102 103 Elf_relent *reltab; 104 int nreltab; 105 106 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 107 long ddbsymcnt; /* Number of symbols */ 108 caddr_t ddbstrtab; /* String table */ 109 long ddbstrcnt; /* number of bytes in string table */ 110 111 caddr_t shstrtab; /* Section name string table */ 112 long shstrcnt; /* number of bytes in string table */ 113 114 caddr_t ctftab; /* CTF table */ 115 long ctfcnt; /* number of bytes in CTF table */ 116 caddr_t ctfoff; /* CTF offset table */ 117 caddr_t typoff; /* Type offset table */ 118 long typlen; /* Number of type entries. */ 119 120 } *elf_file_t; 121 122 #include <kern/kern_ctf.c> 123 124 static int link_elf_link_preload(linker_class_t cls, 125 const char *, linker_file_t *); 126 static int link_elf_link_preload_finish(linker_file_t); 127 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); 128 static int link_elf_lookup_symbol(linker_file_t, const char *, 129 c_linker_sym_t *); 130 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 131 linker_symval_t *); 132 static int link_elf_search_symbol(linker_file_t, caddr_t value, 133 c_linker_sym_t *sym, long *diffp); 134 135 static void link_elf_unload_file(linker_file_t); 136 static int link_elf_lookup_set(linker_file_t, const char *, 137 void ***, void ***, int *); 138 static int link_elf_each_function_name(linker_file_t, 139 int (*)(const char *, void *), void *); 140 static int link_elf_each_function_nameval(linker_file_t, 141 linker_function_nameval_callback_t, 142 void *); 143 static int link_elf_reloc_local(linker_file_t); 144 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 145 static long link_elf_strtab_get(linker_file_t, caddr_t *); 146 147 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, 148 Elf_Addr *); 149 150 static kobj_method_t link_elf_methods[] = { 151 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 152 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 153 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 154 KOBJMETHOD(linker_unload, link_elf_unload_file), 155 KOBJMETHOD(linker_load_file, link_elf_load_file), 156 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 157 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 158 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 159 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 160 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 161 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 162 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 163 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 164 { 0, 0 } 165 }; 166 167 static struct linker_class link_elf_class = { 168 #if ELF_TARG_CLASS == ELFCLASS32 169 "elf32_obj", 170 #else 171 "elf64_obj", 172 #endif 173 link_elf_methods, sizeof(struct elf_file) 174 }; 175 176 static int relocate_file(elf_file_t ef); 177 static void elf_obj_cleanup_globals_cache(elf_file_t); 178 179 static void 180 link_elf_error(const char *filename, const char *s) 181 { 182 if (filename == NULL) 183 printf("kldload: %s\n", s); 184 else 185 printf("kldload: %s: %s\n", filename, s); 186 } 187 188 static void 189 link_elf_init(void *arg) 190 { 191 192 linker_add_class(&link_elf_class); 193 } 194 195 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0); 196 197 static int 198 link_elf_link_preload(linker_class_t cls, const char *filename, 199 linker_file_t *result) 200 { 201 Elf_Ehdr *hdr; 202 Elf_Shdr *shdr; 203 Elf_Sym *es; 204 void *modptr, *baseptr, *sizeptr; 205 char *type; 206 elf_file_t ef; 207 linker_file_t lf; 208 Elf_Addr off; 209 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 210 211 /* Look to see if we have the file preloaded */ 212 modptr = preload_search_by_name(filename); 213 if (modptr == NULL) 214 return ENOENT; 215 216 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 217 baseptr = preload_search_info(modptr, MODINFO_ADDR); 218 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 219 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 220 MODINFOMD_ELFHDR); 221 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 222 MODINFOMD_SHDR); 223 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) 224 " obj module") != 0 && 225 strcmp(type, "elf obj module") != 0)) { 226 return (EFTYPE); 227 } 228 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 229 shdr == NULL) 230 return (EINVAL); 231 232 lf = linker_make_file(filename, &link_elf_class); 233 if (lf == NULL) 234 return (ENOMEM); 235 236 ef = (elf_file_t)lf; 237 ef->preloaded = 1; 238 ef->address = *(caddr_t *)baseptr; 239 lf->address = *(caddr_t *)baseptr; 240 lf->size = *(size_t *)sizeptr; 241 242 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 243 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 244 hdr->e_ident[EI_VERSION] != EV_CURRENT || 245 hdr->e_version != EV_CURRENT || 246 hdr->e_type != ET_REL || 247 hdr->e_machine != ELF_TARG_MACH) { 248 error = EFTYPE; 249 goto out; 250 } 251 ef->e_shdr = shdr; 252 253 /* Scan the section header for information and table sizing. */ 254 symtabindex = -1; 255 symstrindex = -1; 256 for (i = 0; i < hdr->e_shnum; i++) { 257 switch (shdr[i].sh_type) { 258 case SHT_PROGBITS: 259 case SHT_NOBITS: 260 #ifdef __amd64__ 261 case SHT_X86_64_UNWIND: 262 #endif 263 ef->nprogtab++; 264 break; 265 case SHT_SYMTAB: 266 symtabindex = i; 267 symstrindex = shdr[i].sh_link; 268 break; 269 case SHT_REL: 270 ef->nreltab++; 271 break; 272 case SHT_RELA: 273 ef->nrelatab++; 274 break; 275 } 276 } 277 278 shstrindex = hdr->e_shstrndx; 279 if (ef->nprogtab == 0 || symstrindex < 0 || 280 symstrindex >= hdr->e_shnum || 281 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 282 shstrindex >= hdr->e_shnum || 283 shdr[shstrindex].sh_type != SHT_STRTAB) { 284 printf("%s: bad/missing section headers\n", filename); 285 error = ENOEXEC; 286 goto out; 287 } 288 289 /* Allocate space for tracking the load chunks */ 290 if (ef->nprogtab != 0) 291 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 292 M_LINKER, M_WAITOK | M_ZERO); 293 if (ef->nreltab != 0) 294 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 295 M_LINKER, M_WAITOK | M_ZERO); 296 if (ef->nrelatab != 0) 297 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 298 M_LINKER, M_WAITOK | M_ZERO); 299 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 300 (ef->nreltab != 0 && ef->reltab == NULL) || 301 (ef->nrelatab != 0 && ef->relatab == NULL)) { 302 error = ENOMEM; 303 goto out; 304 } 305 306 /* XXX, relocate the sh_addr fields saved by the loader. */ 307 off = 0; 308 for (i = 0; i < hdr->e_shnum; i++) { 309 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 310 off = shdr[i].sh_addr; 311 } 312 for (i = 0; i < hdr->e_shnum; i++) { 313 if (shdr[i].sh_addr != 0) 314 shdr[i].sh_addr = shdr[i].sh_addr - off + 315 (Elf_Addr)ef->address; 316 } 317 318 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 319 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 320 ef->ddbstrcnt = shdr[symstrindex].sh_size; 321 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 322 ef->shstrcnt = shdr[shstrindex].sh_size; 323 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 324 325 /* Now fill out progtab and the relocation tables. */ 326 pb = 0; 327 rl = 0; 328 ra = 0; 329 for (i = 0; i < hdr->e_shnum; i++) { 330 switch (shdr[i].sh_type) { 331 case SHT_PROGBITS: 332 case SHT_NOBITS: 333 #ifdef __amd64__ 334 case SHT_X86_64_UNWIND: 335 #endif 336 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 337 if (shdr[i].sh_type == SHT_PROGBITS) 338 ef->progtab[pb].name = "<<PROGBITS>>"; 339 #ifdef __amd64__ 340 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 341 ef->progtab[pb].name = "<<UNWIND>>"; 342 #endif 343 else 344 ef->progtab[pb].name = "<<NOBITS>>"; 345 ef->progtab[pb].size = shdr[i].sh_size; 346 ef->progtab[pb].sec = i; 347 if (ef->shstrtab && shdr[i].sh_name != 0) 348 ef->progtab[pb].name = 349 ef->shstrtab + shdr[i].sh_name; 350 if (ef->progtab[pb].name != NULL && 351 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 352 void *dpcpu; 353 354 dpcpu = dpcpu_alloc(shdr[i].sh_size); 355 if (dpcpu == NULL) { 356 error = ENOSPC; 357 goto out; 358 } 359 memcpy(dpcpu, ef->progtab[pb].addr, 360 ef->progtab[pb].size); 361 dpcpu_copy(dpcpu, shdr[i].sh_size); 362 ef->progtab[pb].addr = dpcpu; 363 #ifdef VIMAGE 364 } else if (ef->progtab[pb].name != NULL && 365 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 366 void *vnet_data; 367 368 vnet_data = vnet_data_alloc(shdr[i].sh_size); 369 if (vnet_data == NULL) { 370 error = ENOSPC; 371 goto out; 372 } 373 memcpy(vnet_data, ef->progtab[pb].addr, 374 ef->progtab[pb].size); 375 vnet_data_copy(vnet_data, shdr[i].sh_size); 376 ef->progtab[pb].addr = vnet_data; 377 #endif 378 } else if (ef->progtab[pb].name != NULL && 379 !strcmp(ef->progtab[pb].name, ".ctors")) { 380 lf->ctors_addr = ef->progtab[pb].addr; 381 lf->ctors_size = shdr[i].sh_size; 382 } 383 384 /* Update all symbol values with the offset. */ 385 for (j = 0; j < ef->ddbsymcnt; j++) { 386 es = &ef->ddbsymtab[j]; 387 if (es->st_shndx != i) 388 continue; 389 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 390 } 391 pb++; 392 break; 393 case SHT_REL: 394 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 395 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 396 ef->reltab[rl].sec = shdr[i].sh_info; 397 rl++; 398 break; 399 case SHT_RELA: 400 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 401 ef->relatab[ra].nrela = 402 shdr[i].sh_size / sizeof(Elf_Rela); 403 ef->relatab[ra].sec = shdr[i].sh_info; 404 ra++; 405 break; 406 } 407 } 408 if (pb != ef->nprogtab) { 409 printf("%s: lost progbits\n", filename); 410 error = ENOEXEC; 411 goto out; 412 } 413 if (rl != ef->nreltab) { 414 printf("%s: lost reltab\n", filename); 415 error = ENOEXEC; 416 goto out; 417 } 418 if (ra != ef->nrelatab) { 419 printf("%s: lost relatab\n", filename); 420 error = ENOEXEC; 421 goto out; 422 } 423 424 /* Local intra-module relocations */ 425 error = link_elf_reloc_local(lf); 426 if (error != 0) 427 goto out; 428 429 *result = lf; 430 return (0); 431 432 out: 433 /* preload not done this way */ 434 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 435 return (error); 436 } 437 438 static void 439 link_elf_invoke_ctors(caddr_t addr, size_t size) 440 { 441 void (**ctor)(void); 442 size_t i, cnt; 443 444 if (addr == NULL || size == 0) 445 return; 446 cnt = size / sizeof(*ctor); 447 ctor = (void *)addr; 448 for (i = 0; i < cnt; i++) { 449 if (ctor[i] != NULL) 450 (*ctor[i])(); 451 } 452 } 453 454 static int 455 link_elf_link_preload_finish(linker_file_t lf) 456 { 457 elf_file_t ef; 458 int error; 459 460 ef = (elf_file_t)lf; 461 error = relocate_file(ef); 462 if (error) 463 return error; 464 465 /* Notify MD code that a module is being loaded. */ 466 error = elf_cpu_load_file(lf); 467 if (error) 468 return (error); 469 470 /* Invoke .ctors */ 471 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 472 return (0); 473 } 474 475 static int 476 link_elf_load_file(linker_class_t cls, const char *filename, 477 linker_file_t *result) 478 { 479 struct nameidata *nd; 480 struct thread *td = curthread; /* XXX */ 481 Elf_Ehdr *hdr; 482 Elf_Shdr *shdr; 483 Elf_Sym *es; 484 int nbytes, i, j; 485 vm_offset_t mapbase; 486 size_t mapsize; 487 int error = 0; 488 ssize_t resid; 489 int flags; 490 elf_file_t ef; 491 linker_file_t lf; 492 int symtabindex; 493 int symstrindex; 494 int shstrindex; 495 int nsym; 496 int pb, rl, ra; 497 int alignmask; 498 499 shdr = NULL; 500 lf = NULL; 501 mapsize = 0; 502 hdr = NULL; 503 504 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 505 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 506 flags = FREAD; 507 error = vn_open(nd, &flags, 0, NULL); 508 if (error) { 509 free(nd, M_TEMP); 510 return error; 511 } 512 NDFREE(nd, NDF_ONLY_PNBUF); 513 if (nd->ni_vp->v_type != VREG) { 514 error = ENOEXEC; 515 goto out; 516 } 517 #ifdef MAC 518 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 519 if (error) { 520 goto out; 521 } 522 #endif 523 524 /* Read the elf header from the file. */ 525 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 526 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 527 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 528 &resid, td); 529 if (error) 530 goto out; 531 if (resid != 0){ 532 error = ENOEXEC; 533 goto out; 534 } 535 536 if (!IS_ELF(*hdr)) { 537 error = ENOEXEC; 538 goto out; 539 } 540 541 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 542 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 543 link_elf_error(filename, "Unsupported file layout"); 544 error = ENOEXEC; 545 goto out; 546 } 547 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 548 || hdr->e_version != EV_CURRENT) { 549 link_elf_error(filename, "Unsupported file version"); 550 error = ENOEXEC; 551 goto out; 552 } 553 if (hdr->e_type != ET_REL) { 554 error = ENOSYS; 555 goto out; 556 } 557 if (hdr->e_machine != ELF_TARG_MACH) { 558 link_elf_error(filename, "Unsupported machine"); 559 error = ENOEXEC; 560 goto out; 561 } 562 563 lf = linker_make_file(filename, &link_elf_class); 564 if (!lf) { 565 error = ENOMEM; 566 goto out; 567 } 568 ef = (elf_file_t) lf; 569 ef->nprogtab = 0; 570 ef->e_shdr = 0; 571 ef->nreltab = 0; 572 ef->nrelatab = 0; 573 574 /* Allocate and read in the section header */ 575 nbytes = hdr->e_shnum * hdr->e_shentsize; 576 if (nbytes == 0 || hdr->e_shoff == 0 || 577 hdr->e_shentsize != sizeof(Elf_Shdr)) { 578 error = ENOEXEC; 579 goto out; 580 } 581 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 582 ef->e_shdr = shdr; 583 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 584 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 585 NOCRED, &resid, td); 586 if (error) 587 goto out; 588 if (resid) { 589 error = ENOEXEC; 590 goto out; 591 } 592 593 /* Scan the section header for information and table sizing. */ 594 nsym = 0; 595 symtabindex = -1; 596 symstrindex = -1; 597 for (i = 0; i < hdr->e_shnum; i++) { 598 if (shdr[i].sh_size == 0) 599 continue; 600 switch (shdr[i].sh_type) { 601 case SHT_PROGBITS: 602 case SHT_NOBITS: 603 #ifdef __amd64__ 604 case SHT_X86_64_UNWIND: 605 #endif 606 ef->nprogtab++; 607 break; 608 case SHT_SYMTAB: 609 nsym++; 610 symtabindex = i; 611 symstrindex = shdr[i].sh_link; 612 break; 613 case SHT_REL: 614 ef->nreltab++; 615 break; 616 case SHT_RELA: 617 ef->nrelatab++; 618 break; 619 case SHT_STRTAB: 620 break; 621 } 622 } 623 if (ef->nprogtab == 0) { 624 link_elf_error(filename, "file has no contents"); 625 error = ENOEXEC; 626 goto out; 627 } 628 if (nsym != 1) { 629 /* Only allow one symbol table for now */ 630 link_elf_error(filename, "file has no valid symbol table"); 631 error = ENOEXEC; 632 goto out; 633 } 634 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 635 shdr[symstrindex].sh_type != SHT_STRTAB) { 636 link_elf_error(filename, "file has invalid symbol strings"); 637 error = ENOEXEC; 638 goto out; 639 } 640 641 /* Allocate space for tracking the load chunks */ 642 if (ef->nprogtab != 0) 643 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 644 M_LINKER, M_WAITOK | M_ZERO); 645 if (ef->nreltab != 0) 646 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 647 M_LINKER, M_WAITOK | M_ZERO); 648 if (ef->nrelatab != 0) 649 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 650 M_LINKER, M_WAITOK | M_ZERO); 651 652 if (symtabindex == -1) { 653 link_elf_error(filename, "lost symbol table index"); 654 error = ENOEXEC; 655 goto out; 656 } 657 /* Allocate space for and load the symbol table */ 658 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 659 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 660 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 661 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 662 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 663 &resid, td); 664 if (error) 665 goto out; 666 if (resid != 0){ 667 error = EINVAL; 668 goto out; 669 } 670 671 if (symstrindex == -1) { 672 link_elf_error(filename, "lost symbol string index"); 673 error = ENOEXEC; 674 goto out; 675 } 676 /* Allocate space for and load the symbol strings */ 677 ef->ddbstrcnt = shdr[symstrindex].sh_size; 678 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 679 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 680 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 681 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 682 &resid, td); 683 if (error) 684 goto out; 685 if (resid != 0){ 686 error = EINVAL; 687 goto out; 688 } 689 690 /* Do we have a string table for the section names? */ 691 shstrindex = -1; 692 if (hdr->e_shstrndx != 0 && 693 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 694 shstrindex = hdr->e_shstrndx; 695 ef->shstrcnt = shdr[shstrindex].sh_size; 696 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 697 M_WAITOK); 698 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 699 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 700 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 701 &resid, td); 702 if (error) 703 goto out; 704 if (resid != 0){ 705 error = EINVAL; 706 goto out; 707 } 708 } 709 710 /* Size up code/data(progbits) and bss(nobits). */ 711 alignmask = 0; 712 for (i = 0; i < hdr->e_shnum; i++) { 713 if (shdr[i].sh_size == 0) 714 continue; 715 switch (shdr[i].sh_type) { 716 case SHT_PROGBITS: 717 case SHT_NOBITS: 718 #ifdef __amd64__ 719 case SHT_X86_64_UNWIND: 720 #endif 721 alignmask = shdr[i].sh_addralign - 1; 722 mapsize += alignmask; 723 mapsize &= ~alignmask; 724 mapsize += shdr[i].sh_size; 725 break; 726 } 727 } 728 729 /* 730 * We know how much space we need for the text/data/bss/etc. 731 * This stuff needs to be in a single chunk so that profiling etc 732 * can get the bounds and gdb can associate offsets with modules 733 */ 734 ef->object = vm_object_allocate(OBJT_DEFAULT, 735 round_page(mapsize) >> PAGE_SHIFT); 736 if (ef->object == NULL) { 737 error = ENOMEM; 738 goto out; 739 } 740 ef->address = (caddr_t) vm_map_min(kernel_map); 741 742 /* 743 * In order to satisfy amd64's architectural requirements on the 744 * location of code and data in the kernel's address space, request a 745 * mapping that is above the kernel. 746 */ 747 #ifdef __amd64__ 748 mapbase = KERNBASE; 749 #else 750 mapbase = VM_MIN_KERNEL_ADDRESS; 751 #endif 752 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 753 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 754 VM_PROT_ALL, 0); 755 if (error) { 756 vm_object_deallocate(ef->object); 757 ef->object = 0; 758 goto out; 759 } 760 761 /* Wire the pages */ 762 error = vm_map_wire(kernel_map, mapbase, 763 mapbase + round_page(mapsize), 764 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 765 if (error != KERN_SUCCESS) { 766 error = ENOMEM; 767 goto out; 768 } 769 770 /* Inform the kld system about the situation */ 771 lf->address = ef->address = (caddr_t)mapbase; 772 lf->size = mapsize; 773 774 /* 775 * Now load code/data(progbits), zero bss(nobits), allocate space for 776 * and load relocs 777 */ 778 pb = 0; 779 rl = 0; 780 ra = 0; 781 alignmask = 0; 782 for (i = 0; i < hdr->e_shnum; i++) { 783 if (shdr[i].sh_size == 0) 784 continue; 785 switch (shdr[i].sh_type) { 786 case SHT_PROGBITS: 787 case SHT_NOBITS: 788 #ifdef __amd64__ 789 case SHT_X86_64_UNWIND: 790 #endif 791 alignmask = shdr[i].sh_addralign - 1; 792 mapbase += alignmask; 793 mapbase &= ~alignmask; 794 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 795 ef->progtab[pb].name = 796 ef->shstrtab + shdr[i].sh_name; 797 if (!strcmp(ef->progtab[pb].name, ".ctors")) { 798 lf->ctors_addr = (caddr_t)mapbase; 799 lf->ctors_size = shdr[i].sh_size; 800 } 801 } else if (shdr[i].sh_type == SHT_PROGBITS) 802 ef->progtab[pb].name = "<<PROGBITS>>"; 803 #ifdef __amd64__ 804 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 805 ef->progtab[pb].name = "<<UNWIND>>"; 806 #endif 807 else 808 ef->progtab[pb].name = "<<NOBITS>>"; 809 if (ef->progtab[pb].name != NULL && 810 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 811 ef->progtab[pb].addr = 812 dpcpu_alloc(shdr[i].sh_size); 813 #ifdef VIMAGE 814 else if (ef->progtab[pb].name != NULL && 815 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 816 ef->progtab[pb].addr = 817 vnet_data_alloc(shdr[i].sh_size); 818 #endif 819 else 820 ef->progtab[pb].addr = 821 (void *)(uintptr_t)mapbase; 822 if (ef->progtab[pb].addr == NULL) { 823 error = ENOSPC; 824 goto out; 825 } 826 ef->progtab[pb].size = shdr[i].sh_size; 827 ef->progtab[pb].sec = i; 828 if (shdr[i].sh_type == SHT_PROGBITS 829 #ifdef __amd64__ 830 || shdr[i].sh_type == SHT_X86_64_UNWIND 831 #endif 832 ) { 833 error = vn_rdwr(UIO_READ, nd->ni_vp, 834 ef->progtab[pb].addr, 835 shdr[i].sh_size, shdr[i].sh_offset, 836 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 837 NOCRED, &resid, td); 838 if (error) 839 goto out; 840 if (resid != 0){ 841 error = EINVAL; 842 goto out; 843 } 844 /* Initialize the per-cpu or vnet area. */ 845 if (ef->progtab[pb].addr != (void *)mapbase && 846 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 847 dpcpu_copy(ef->progtab[pb].addr, 848 shdr[i].sh_size); 849 #ifdef VIMAGE 850 else if (ef->progtab[pb].addr != 851 (void *)mapbase && 852 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 853 vnet_data_copy(ef->progtab[pb].addr, 854 shdr[i].sh_size); 855 #endif 856 } else 857 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 858 859 /* Update all symbol values with the offset. */ 860 for (j = 0; j < ef->ddbsymcnt; j++) { 861 es = &ef->ddbsymtab[j]; 862 if (es->st_shndx != i) 863 continue; 864 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 865 } 866 mapbase += shdr[i].sh_size; 867 pb++; 868 break; 869 case SHT_REL: 870 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 871 M_WAITOK); 872 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 873 ef->reltab[rl].sec = shdr[i].sh_info; 874 error = vn_rdwr(UIO_READ, nd->ni_vp, 875 (void *)ef->reltab[rl].rel, 876 shdr[i].sh_size, shdr[i].sh_offset, 877 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 878 &resid, td); 879 if (error) 880 goto out; 881 if (resid != 0){ 882 error = EINVAL; 883 goto out; 884 } 885 rl++; 886 break; 887 case SHT_RELA: 888 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 889 M_WAITOK); 890 ef->relatab[ra].nrela = 891 shdr[i].sh_size / sizeof(Elf_Rela); 892 ef->relatab[ra].sec = shdr[i].sh_info; 893 error = vn_rdwr(UIO_READ, nd->ni_vp, 894 (void *)ef->relatab[ra].rela, 895 shdr[i].sh_size, shdr[i].sh_offset, 896 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 897 &resid, td); 898 if (error) 899 goto out; 900 if (resid != 0){ 901 error = EINVAL; 902 goto out; 903 } 904 ra++; 905 break; 906 } 907 } 908 if (pb != ef->nprogtab) { 909 link_elf_error(filename, "lost progbits"); 910 error = ENOEXEC; 911 goto out; 912 } 913 if (rl != ef->nreltab) { 914 link_elf_error(filename, "lost reltab"); 915 error = ENOEXEC; 916 goto out; 917 } 918 if (ra != ef->nrelatab) { 919 link_elf_error(filename, "lost relatab"); 920 error = ENOEXEC; 921 goto out; 922 } 923 if (mapbase != (vm_offset_t)ef->address + mapsize) { 924 printf( 925 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 926 filename != NULL ? filename : "<none>", 927 (u_long)mapbase, ef->address, (u_long)mapsize, 928 (u_long)(vm_offset_t)ef->address + mapsize); 929 error = ENOMEM; 930 goto out; 931 } 932 933 /* Local intra-module relocations */ 934 error = link_elf_reloc_local(lf); 935 if (error != 0) 936 goto out; 937 938 /* Pull in dependencies */ 939 VOP_UNLOCK(nd->ni_vp, 0); 940 error = linker_load_dependencies(lf); 941 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 942 if (error) 943 goto out; 944 945 /* External relocations */ 946 error = relocate_file(ef); 947 if (error) 948 goto out; 949 950 /* Notify MD code that a module is being loaded. */ 951 error = elf_cpu_load_file(lf); 952 if (error) 953 goto out; 954 955 /* Invoke .ctors */ 956 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 957 958 *result = lf; 959 960 out: 961 VOP_UNLOCK(nd->ni_vp, 0); 962 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 963 free(nd, M_TEMP); 964 if (error && lf) 965 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 966 free(hdr, M_LINKER); 967 968 return error; 969 } 970 971 static void 972 link_elf_unload_file(linker_file_t file) 973 { 974 elf_file_t ef = (elf_file_t) file; 975 int i; 976 977 /* Notify MD code that a module is being unloaded. */ 978 elf_cpu_unload_file(file); 979 980 if (ef->progtab) { 981 for (i = 0; i < ef->nprogtab; i++) { 982 if (ef->progtab[i].size == 0) 983 continue; 984 if (ef->progtab[i].name == NULL) 985 continue; 986 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 987 dpcpu_free(ef->progtab[i].addr, 988 ef->progtab[i].size); 989 #ifdef VIMAGE 990 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 991 vnet_data_free(ef->progtab[i].addr, 992 ef->progtab[i].size); 993 #endif 994 } 995 } 996 if (ef->preloaded) { 997 free(ef->reltab, M_LINKER); 998 free(ef->relatab, M_LINKER); 999 free(ef->progtab, M_LINKER); 1000 free(ef->ctftab, M_LINKER); 1001 free(ef->ctfoff, M_LINKER); 1002 free(ef->typoff, M_LINKER); 1003 if (file->filename != NULL) 1004 preload_delete_name(file->filename); 1005 /* XXX reclaim module memory? */ 1006 return; 1007 } 1008 1009 for (i = 0; i < ef->nreltab; i++) 1010 free(ef->reltab[i].rel, M_LINKER); 1011 for (i = 0; i < ef->nrelatab; i++) 1012 free(ef->relatab[i].rela, M_LINKER); 1013 free(ef->reltab, M_LINKER); 1014 free(ef->relatab, M_LINKER); 1015 free(ef->progtab, M_LINKER); 1016 1017 if (ef->object) { 1018 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1019 (vm_offset_t) ef->address + 1020 (ef->object->size << PAGE_SHIFT)); 1021 } 1022 free(ef->e_shdr, M_LINKER); 1023 free(ef->ddbsymtab, M_LINKER); 1024 free(ef->ddbstrtab, M_LINKER); 1025 free(ef->shstrtab, M_LINKER); 1026 free(ef->ctftab, M_LINKER); 1027 free(ef->ctfoff, M_LINKER); 1028 free(ef->typoff, M_LINKER); 1029 } 1030 1031 static const char * 1032 symbol_name(elf_file_t ef, Elf_Size r_info) 1033 { 1034 const Elf_Sym *ref; 1035 1036 if (ELF_R_SYM(r_info)) { 1037 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1038 return ef->ddbstrtab + ref->st_name; 1039 } else 1040 return NULL; 1041 } 1042 1043 static Elf_Addr 1044 findbase(elf_file_t ef, int sec) 1045 { 1046 int i; 1047 Elf_Addr base = 0; 1048 1049 for (i = 0; i < ef->nprogtab; i++) { 1050 if (sec == ef->progtab[i].sec) { 1051 base = (Elf_Addr)ef->progtab[i].addr; 1052 break; 1053 } 1054 } 1055 return base; 1056 } 1057 1058 static int 1059 relocate_file(elf_file_t ef) 1060 { 1061 const Elf_Rel *rellim; 1062 const Elf_Rel *rel; 1063 const Elf_Rela *relalim; 1064 const Elf_Rela *rela; 1065 const char *symname; 1066 const Elf_Sym *sym; 1067 int i; 1068 Elf_Size symidx; 1069 Elf_Addr base; 1070 1071 1072 /* Perform relocations without addend if there are any: */ 1073 for (i = 0; i < ef->nreltab; i++) { 1074 rel = ef->reltab[i].rel; 1075 if (rel == NULL) { 1076 link_elf_error(ef->lf.filename, "lost a reltab!"); 1077 return (ENOEXEC); 1078 } 1079 rellim = rel + ef->reltab[i].nrel; 1080 base = findbase(ef, ef->reltab[i].sec); 1081 if (base == 0) { 1082 link_elf_error(ef->lf.filename, "lost base for reltab"); 1083 return (ENOEXEC); 1084 } 1085 for ( ; rel < rellim; rel++) { 1086 symidx = ELF_R_SYM(rel->r_info); 1087 if (symidx >= ef->ddbsymcnt) 1088 continue; 1089 sym = ef->ddbsymtab + symidx; 1090 /* Local relocs are already done */ 1091 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1092 continue; 1093 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1094 elf_obj_lookup)) { 1095 symname = symbol_name(ef, rel->r_info); 1096 printf("link_elf_obj: symbol %s undefined\n", 1097 symname); 1098 return (ENOENT); 1099 } 1100 } 1101 } 1102 1103 /* Perform relocations with addend if there are any: */ 1104 for (i = 0; i < ef->nrelatab; i++) { 1105 rela = ef->relatab[i].rela; 1106 if (rela == NULL) { 1107 link_elf_error(ef->lf.filename, "lost a relatab!"); 1108 return (ENOEXEC); 1109 } 1110 relalim = rela + ef->relatab[i].nrela; 1111 base = findbase(ef, ef->relatab[i].sec); 1112 if (base == 0) { 1113 link_elf_error(ef->lf.filename, 1114 "lost base for relatab"); 1115 return (ENOEXEC); 1116 } 1117 for ( ; rela < relalim; rela++) { 1118 symidx = ELF_R_SYM(rela->r_info); 1119 if (symidx >= ef->ddbsymcnt) 1120 continue; 1121 sym = ef->ddbsymtab + symidx; 1122 /* Local relocs are already done */ 1123 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1124 continue; 1125 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1126 elf_obj_lookup)) { 1127 symname = symbol_name(ef, rela->r_info); 1128 printf("link_elf_obj: symbol %s undefined\n", 1129 symname); 1130 return (ENOENT); 1131 } 1132 } 1133 } 1134 1135 /* 1136 * Only clean SHN_FBSD_CACHED for successful return. If we 1137 * modified symbol table for the object but found an 1138 * unresolved symbol, there is no reason to roll back. 1139 */ 1140 elf_obj_cleanup_globals_cache(ef); 1141 1142 return (0); 1143 } 1144 1145 static int 1146 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1147 { 1148 elf_file_t ef = (elf_file_t) lf; 1149 const Elf_Sym *symp; 1150 const char *strp; 1151 int i; 1152 1153 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1154 strp = ef->ddbstrtab + symp->st_name; 1155 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1156 *sym = (c_linker_sym_t) symp; 1157 return 0; 1158 } 1159 } 1160 return ENOENT; 1161 } 1162 1163 static int 1164 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1165 linker_symval_t *symval) 1166 { 1167 elf_file_t ef = (elf_file_t) lf; 1168 const Elf_Sym *es = (const Elf_Sym*) sym; 1169 1170 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1171 symval->name = ef->ddbstrtab + es->st_name; 1172 symval->value = (caddr_t)es->st_value; 1173 symval->size = es->st_size; 1174 return 0; 1175 } 1176 return ENOENT; 1177 } 1178 1179 static int 1180 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1181 c_linker_sym_t *sym, long *diffp) 1182 { 1183 elf_file_t ef = (elf_file_t) lf; 1184 u_long off = (uintptr_t) (void *) value; 1185 u_long diff = off; 1186 u_long st_value; 1187 const Elf_Sym *es; 1188 const Elf_Sym *best = NULL; 1189 int i; 1190 1191 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1192 if (es->st_name == 0) 1193 continue; 1194 st_value = es->st_value; 1195 if (off >= st_value) { 1196 if (off - st_value < diff) { 1197 diff = off - st_value; 1198 best = es; 1199 if (diff == 0) 1200 break; 1201 } else if (off - st_value == diff) { 1202 best = es; 1203 } 1204 } 1205 } 1206 if (best == NULL) 1207 *diffp = off; 1208 else 1209 *diffp = diff; 1210 *sym = (c_linker_sym_t) best; 1211 1212 return 0; 1213 } 1214 1215 /* 1216 * Look up a linker set on an ELF system. 1217 */ 1218 static int 1219 link_elf_lookup_set(linker_file_t lf, const char *name, 1220 void ***startp, void ***stopp, int *countp) 1221 { 1222 elf_file_t ef = (elf_file_t)lf; 1223 void **start, **stop; 1224 int i, count; 1225 1226 /* Relative to section number */ 1227 for (i = 0; i < ef->nprogtab; i++) { 1228 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1229 strcmp(ef->progtab[i].name + 4, name) == 0) { 1230 start = (void **)ef->progtab[i].addr; 1231 stop = (void **)((char *)ef->progtab[i].addr + 1232 ef->progtab[i].size); 1233 count = stop - start; 1234 if (startp) 1235 *startp = start; 1236 if (stopp) 1237 *stopp = stop; 1238 if (countp) 1239 *countp = count; 1240 return (0); 1241 } 1242 } 1243 return (ESRCH); 1244 } 1245 1246 static int 1247 link_elf_each_function_name(linker_file_t file, 1248 int (*callback)(const char *, void *), void *opaque) 1249 { 1250 elf_file_t ef = (elf_file_t)file; 1251 const Elf_Sym *symp; 1252 int i, error; 1253 1254 /* Exhaustive search */ 1255 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1256 if (symp->st_value != 0 && 1257 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1258 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1259 if (error) 1260 return (error); 1261 } 1262 } 1263 return (0); 1264 } 1265 1266 static int 1267 link_elf_each_function_nameval(linker_file_t file, 1268 linker_function_nameval_callback_t callback, void *opaque) 1269 { 1270 linker_symval_t symval; 1271 elf_file_t ef = (elf_file_t)file; 1272 const Elf_Sym* symp; 1273 int i, error; 1274 1275 /* Exhaustive search */ 1276 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1277 if (symp->st_value != 0 && 1278 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1279 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1280 if (error) 1281 return (error); 1282 error = callback(file, i, &symval, opaque); 1283 if (error) 1284 return (error); 1285 } 1286 } 1287 return (0); 1288 } 1289 1290 static void 1291 elf_obj_cleanup_globals_cache(elf_file_t ef) 1292 { 1293 Elf_Sym *sym; 1294 Elf_Size i; 1295 1296 for (i = 0; i < ef->ddbsymcnt; i++) { 1297 sym = ef->ddbsymtab + i; 1298 if (sym->st_shndx == SHN_FBSD_CACHED) { 1299 sym->st_shndx = SHN_UNDEF; 1300 sym->st_value = 0; 1301 } 1302 } 1303 } 1304 1305 /* 1306 * Symbol lookup function that can be used when the symbol index is known (ie 1307 * in relocations). It uses the symbol index instead of doing a fully fledged 1308 * hash table based lookup when such is valid. For example for local symbols. 1309 * This is not only more efficient, it's also more correct. It's not always 1310 * the case that the symbol can be found through the hash table. 1311 */ 1312 static int 1313 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1314 { 1315 elf_file_t ef = (elf_file_t)lf; 1316 Elf_Sym *sym; 1317 const char *symbol; 1318 Elf_Addr res1; 1319 1320 /* Don't even try to lookup the symbol if the index is bogus. */ 1321 if (symidx >= ef->ddbsymcnt) { 1322 *res = 0; 1323 return (EINVAL); 1324 } 1325 1326 sym = ef->ddbsymtab + symidx; 1327 1328 /* Quick answer if there is a definition included. */ 1329 if (sym->st_shndx != SHN_UNDEF) { 1330 *res = sym->st_value; 1331 return (0); 1332 } 1333 1334 /* If we get here, then it is undefined and needs a lookup. */ 1335 switch (ELF_ST_BIND(sym->st_info)) { 1336 case STB_LOCAL: 1337 /* Local, but undefined? huh? */ 1338 *res = 0; 1339 return (EINVAL); 1340 1341 case STB_GLOBAL: 1342 case STB_WEAK: 1343 /* Relative to Data or Function name */ 1344 symbol = ef->ddbstrtab + sym->st_name; 1345 1346 /* Force a lookup failure if the symbol name is bogus. */ 1347 if (*symbol == 0) { 1348 *res = 0; 1349 return (EINVAL); 1350 } 1351 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1352 1353 /* 1354 * Cache global lookups during module relocation. The failure 1355 * case is particularly expensive for callers, who must scan 1356 * through the entire globals table doing strcmp(). Cache to 1357 * avoid doing such work repeatedly. 1358 * 1359 * After relocation is complete, undefined globals will be 1360 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1361 * above. 1362 */ 1363 if (res1 != 0) { 1364 sym->st_shndx = SHN_FBSD_CACHED; 1365 sym->st_value = res1; 1366 *res = res1; 1367 return (0); 1368 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1369 sym->st_value = 0; 1370 *res = 0; 1371 return (0); 1372 } 1373 return (EINVAL); 1374 1375 default: 1376 return (EINVAL); 1377 } 1378 } 1379 1380 static void 1381 link_elf_fix_link_set(elf_file_t ef) 1382 { 1383 static const char startn[] = "__start_"; 1384 static const char stopn[] = "__stop_"; 1385 Elf_Sym *sym; 1386 const char *sym_name, *linkset_name; 1387 Elf_Addr startp, stopp; 1388 Elf_Size symidx; 1389 int start, i; 1390 1391 startp = stopp = 0; 1392 for (symidx = 1 /* zero entry is special */; 1393 symidx < ef->ddbsymcnt; symidx++) { 1394 sym = ef->ddbsymtab + symidx; 1395 if (sym->st_shndx != SHN_UNDEF) 1396 continue; 1397 1398 sym_name = ef->ddbstrtab + sym->st_name; 1399 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1400 start = 1; 1401 linkset_name = sym_name + sizeof(startn) - 1; 1402 } 1403 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1404 start = 0; 1405 linkset_name = sym_name + sizeof(stopn) - 1; 1406 } 1407 else 1408 continue; 1409 1410 for (i = 0; i < ef->nprogtab; i++) { 1411 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1412 startp = (Elf_Addr)ef->progtab[i].addr; 1413 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1414 break; 1415 } 1416 } 1417 if (i == ef->nprogtab) 1418 continue; 1419 1420 sym->st_value = start ? startp : stopp; 1421 sym->st_shndx = i; 1422 } 1423 } 1424 1425 static int 1426 link_elf_reloc_local(linker_file_t lf) 1427 { 1428 elf_file_t ef = (elf_file_t)lf; 1429 const Elf_Rel *rellim; 1430 const Elf_Rel *rel; 1431 const Elf_Rela *relalim; 1432 const Elf_Rela *rela; 1433 const Elf_Sym *sym; 1434 Elf_Addr base; 1435 int i; 1436 Elf_Size symidx; 1437 1438 link_elf_fix_link_set(ef); 1439 1440 /* Perform relocations without addend if there are any: */ 1441 for (i = 0; i < ef->nreltab; i++) { 1442 rel = ef->reltab[i].rel; 1443 if (rel == NULL) { 1444 link_elf_error(ef->lf.filename, "lost a reltab"); 1445 return (ENOEXEC); 1446 } 1447 rellim = rel + ef->reltab[i].nrel; 1448 base = findbase(ef, ef->reltab[i].sec); 1449 if (base == 0) { 1450 link_elf_error(ef->lf.filename, "lost base for reltab"); 1451 return (ENOEXEC); 1452 } 1453 for ( ; rel < rellim; rel++) { 1454 symidx = ELF_R_SYM(rel->r_info); 1455 if (symidx >= ef->ddbsymcnt) 1456 continue; 1457 sym = ef->ddbsymtab + symidx; 1458 /* Only do local relocs */ 1459 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1460 continue; 1461 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1462 elf_obj_lookup); 1463 } 1464 } 1465 1466 /* Perform relocations with addend if there are any: */ 1467 for (i = 0; i < ef->nrelatab; i++) { 1468 rela = ef->relatab[i].rela; 1469 if (rela == NULL) { 1470 link_elf_error(ef->lf.filename, "lost a relatab!"); 1471 return (ENOEXEC); 1472 } 1473 relalim = rela + ef->relatab[i].nrela; 1474 base = findbase(ef, ef->relatab[i].sec); 1475 if (base == 0) { 1476 link_elf_error(ef->lf.filename, "lost base for reltab"); 1477 return (ENOEXEC); 1478 } 1479 for ( ; rela < relalim; rela++) { 1480 symidx = ELF_R_SYM(rela->r_info); 1481 if (symidx >= ef->ddbsymcnt) 1482 continue; 1483 sym = ef->ddbsymtab + symidx; 1484 /* Only do local relocs */ 1485 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1486 continue; 1487 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1488 elf_obj_lookup); 1489 } 1490 } 1491 return (0); 1492 } 1493 1494 static long 1495 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1496 { 1497 elf_file_t ef = (elf_file_t)lf; 1498 1499 *symtab = ef->ddbsymtab; 1500 1501 if (*symtab == NULL) 1502 return (0); 1503 1504 return (ef->ddbsymcnt); 1505 } 1506 1507 static long 1508 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1509 { 1510 elf_file_t ef = (elf_file_t)lf; 1511 1512 *strtab = ef->ddbstrtab; 1513 1514 if (*strtab == NULL) 1515 return (0); 1516 1517 return (ef->ddbstrcnt); 1518 } 1519