1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998-2000 Doug Rabson 5 * Copyright (c) 2004 Peter Wemm 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_ddb.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/malloc.h> 40 #include <sys/mutex.h> 41 #include <sys/mount.h> 42 #include <sys/proc.h> 43 #include <sys/namei.h> 44 #include <sys/fcntl.h> 45 #include <sys/vnode.h> 46 #include <sys/linker.h> 47 48 #include <machine/elf.h> 49 50 #include <net/vnet.h> 51 52 #include <security/mac/mac_framework.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_param.h> 56 #include <vm/vm_object.h> 57 #include <vm/vm_kern.h> 58 #include <vm/vm_extern.h> 59 #include <vm/pmap.h> 60 #include <vm/vm_map.h> 61 62 #include <sys/link_elf.h> 63 64 #ifdef DDB_CTF 65 #include <sys/zlib.h> 66 #endif 67 68 #include "linker_if.h" 69 70 typedef struct { 71 void *addr; 72 Elf_Off size; 73 int flags; 74 int sec; /* Original section */ 75 char *name; 76 } Elf_progent; 77 78 typedef struct { 79 Elf_Rel *rel; 80 int nrel; 81 int sec; 82 } Elf_relent; 83 84 typedef struct { 85 Elf_Rela *rela; 86 int nrela; 87 int sec; 88 } Elf_relaent; 89 90 91 typedef struct elf_file { 92 struct linker_file lf; /* Common fields */ 93 94 int preloaded; 95 caddr_t address; /* Relocation address */ 96 vm_object_t object; /* VM object to hold file pages */ 97 Elf_Shdr *e_shdr; 98 99 Elf_progent *progtab; 100 int nprogtab; 101 102 Elf_relaent *relatab; 103 int nrelatab; 104 105 Elf_relent *reltab; 106 int nreltab; 107 108 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 109 long ddbsymcnt; /* Number of symbols */ 110 caddr_t ddbstrtab; /* String table */ 111 long ddbstrcnt; /* number of bytes in string table */ 112 113 caddr_t shstrtab; /* Section name string table */ 114 long shstrcnt; /* number of bytes in string table */ 115 116 caddr_t ctftab; /* CTF table */ 117 long ctfcnt; /* number of bytes in CTF table */ 118 caddr_t ctfoff; /* CTF offset table */ 119 caddr_t typoff; /* Type offset table */ 120 long typlen; /* Number of type entries. */ 121 122 } *elf_file_t; 123 124 #include <kern/kern_ctf.c> 125 126 static int link_elf_link_preload(linker_class_t cls, 127 const char *, linker_file_t *); 128 static int link_elf_link_preload_finish(linker_file_t); 129 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); 130 static int link_elf_lookup_symbol(linker_file_t, const char *, 131 c_linker_sym_t *); 132 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 133 linker_symval_t *); 134 static int link_elf_search_symbol(linker_file_t, caddr_t value, 135 c_linker_sym_t *sym, long *diffp); 136 137 static void link_elf_unload_file(linker_file_t); 138 static int link_elf_lookup_set(linker_file_t, const char *, 139 void ***, void ***, int *); 140 static int link_elf_each_function_name(linker_file_t, 141 int (*)(const char *, void *), void *); 142 static int link_elf_each_function_nameval(linker_file_t, 143 linker_function_nameval_callback_t, 144 void *); 145 static int link_elf_reloc_local(linker_file_t); 146 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 147 static long link_elf_strtab_get(linker_file_t, caddr_t *); 148 149 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, 150 Elf_Addr *); 151 152 static kobj_method_t link_elf_methods[] = { 153 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 154 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 155 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 156 KOBJMETHOD(linker_unload, link_elf_unload_file), 157 KOBJMETHOD(linker_load_file, link_elf_load_file), 158 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 159 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 160 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 161 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 162 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 163 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 164 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 165 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 166 { 0, 0 } 167 }; 168 169 static struct linker_class link_elf_class = { 170 #if ELF_TARG_CLASS == ELFCLASS32 171 "elf32_obj", 172 #else 173 "elf64_obj", 174 #endif 175 link_elf_methods, sizeof(struct elf_file) 176 }; 177 178 static int relocate_file(elf_file_t ef); 179 static void elf_obj_cleanup_globals_cache(elf_file_t); 180 181 static void 182 link_elf_error(const char *filename, const char *s) 183 { 184 if (filename == NULL) 185 printf("kldload: %s\n", s); 186 else 187 printf("kldload: %s: %s\n", filename, s); 188 } 189 190 static void 191 link_elf_init(void *arg) 192 { 193 194 linker_add_class(&link_elf_class); 195 } 196 197 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0); 198 199 static int 200 link_elf_link_preload(linker_class_t cls, const char *filename, 201 linker_file_t *result) 202 { 203 Elf_Ehdr *hdr; 204 Elf_Shdr *shdr; 205 Elf_Sym *es; 206 void *modptr, *baseptr, *sizeptr; 207 char *type; 208 elf_file_t ef; 209 linker_file_t lf; 210 Elf_Addr off; 211 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 212 213 /* Look to see if we have the file preloaded */ 214 modptr = preload_search_by_name(filename); 215 if (modptr == NULL) 216 return ENOENT; 217 218 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 219 baseptr = preload_search_info(modptr, MODINFO_ADDR); 220 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 221 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 222 MODINFOMD_ELFHDR); 223 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 224 MODINFOMD_SHDR); 225 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) 226 " obj module") != 0 && 227 strcmp(type, "elf obj module") != 0)) { 228 return (EFTYPE); 229 } 230 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 231 shdr == NULL) 232 return (EINVAL); 233 234 lf = linker_make_file(filename, &link_elf_class); 235 if (lf == NULL) 236 return (ENOMEM); 237 238 ef = (elf_file_t)lf; 239 ef->preloaded = 1; 240 ef->address = *(caddr_t *)baseptr; 241 lf->address = *(caddr_t *)baseptr; 242 lf->size = *(size_t *)sizeptr; 243 244 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 245 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 246 hdr->e_ident[EI_VERSION] != EV_CURRENT || 247 hdr->e_version != EV_CURRENT || 248 hdr->e_type != ET_REL || 249 hdr->e_machine != ELF_TARG_MACH) { 250 error = EFTYPE; 251 goto out; 252 } 253 ef->e_shdr = shdr; 254 255 /* Scan the section header for information and table sizing. */ 256 symtabindex = -1; 257 symstrindex = -1; 258 for (i = 0; i < hdr->e_shnum; i++) { 259 switch (shdr[i].sh_type) { 260 case SHT_PROGBITS: 261 case SHT_NOBITS: 262 #ifdef __amd64__ 263 case SHT_X86_64_UNWIND: 264 #endif 265 ef->nprogtab++; 266 break; 267 case SHT_SYMTAB: 268 symtabindex = i; 269 symstrindex = shdr[i].sh_link; 270 break; 271 case SHT_REL: 272 ef->nreltab++; 273 break; 274 case SHT_RELA: 275 ef->nrelatab++; 276 break; 277 } 278 } 279 280 shstrindex = hdr->e_shstrndx; 281 if (ef->nprogtab == 0 || symstrindex < 0 || 282 symstrindex >= hdr->e_shnum || 283 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 284 shstrindex >= hdr->e_shnum || 285 shdr[shstrindex].sh_type != SHT_STRTAB) { 286 printf("%s: bad/missing section headers\n", filename); 287 error = ENOEXEC; 288 goto out; 289 } 290 291 /* Allocate space for tracking the load chunks */ 292 if (ef->nprogtab != 0) 293 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 294 M_LINKER, M_WAITOK | M_ZERO); 295 if (ef->nreltab != 0) 296 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 297 M_LINKER, M_WAITOK | M_ZERO); 298 if (ef->nrelatab != 0) 299 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 300 M_LINKER, M_WAITOK | M_ZERO); 301 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 302 (ef->nreltab != 0 && ef->reltab == NULL) || 303 (ef->nrelatab != 0 && ef->relatab == NULL)) { 304 error = ENOMEM; 305 goto out; 306 } 307 308 /* XXX, relocate the sh_addr fields saved by the loader. */ 309 off = 0; 310 for (i = 0; i < hdr->e_shnum; i++) { 311 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 312 off = shdr[i].sh_addr; 313 } 314 for (i = 0; i < hdr->e_shnum; i++) { 315 if (shdr[i].sh_addr != 0) 316 shdr[i].sh_addr = shdr[i].sh_addr - off + 317 (Elf_Addr)ef->address; 318 } 319 320 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 321 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 322 ef->ddbstrcnt = shdr[symstrindex].sh_size; 323 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 324 ef->shstrcnt = shdr[shstrindex].sh_size; 325 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 326 327 /* Now fill out progtab and the relocation tables. */ 328 pb = 0; 329 rl = 0; 330 ra = 0; 331 for (i = 0; i < hdr->e_shnum; i++) { 332 switch (shdr[i].sh_type) { 333 case SHT_PROGBITS: 334 case SHT_NOBITS: 335 #ifdef __amd64__ 336 case SHT_X86_64_UNWIND: 337 #endif 338 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 339 if (shdr[i].sh_type == SHT_PROGBITS) 340 ef->progtab[pb].name = "<<PROGBITS>>"; 341 #ifdef __amd64__ 342 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 343 ef->progtab[pb].name = "<<UNWIND>>"; 344 #endif 345 else 346 ef->progtab[pb].name = "<<NOBITS>>"; 347 ef->progtab[pb].size = shdr[i].sh_size; 348 ef->progtab[pb].sec = i; 349 if (ef->shstrtab && shdr[i].sh_name != 0) 350 ef->progtab[pb].name = 351 ef->shstrtab + shdr[i].sh_name; 352 if (ef->progtab[pb].name != NULL && 353 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 354 void *dpcpu; 355 356 dpcpu = dpcpu_alloc(shdr[i].sh_size); 357 if (dpcpu == NULL) { 358 error = ENOSPC; 359 goto out; 360 } 361 memcpy(dpcpu, ef->progtab[pb].addr, 362 ef->progtab[pb].size); 363 dpcpu_copy(dpcpu, shdr[i].sh_size); 364 ef->progtab[pb].addr = dpcpu; 365 #ifdef VIMAGE 366 } else if (ef->progtab[pb].name != NULL && 367 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 368 void *vnet_data; 369 370 vnet_data = vnet_data_alloc(shdr[i].sh_size); 371 if (vnet_data == NULL) { 372 error = ENOSPC; 373 goto out; 374 } 375 memcpy(vnet_data, ef->progtab[pb].addr, 376 ef->progtab[pb].size); 377 vnet_data_copy(vnet_data, shdr[i].sh_size); 378 ef->progtab[pb].addr = vnet_data; 379 #endif 380 } else if (ef->progtab[pb].name != NULL && 381 !strcmp(ef->progtab[pb].name, ".ctors")) { 382 lf->ctors_addr = ef->progtab[pb].addr; 383 lf->ctors_size = shdr[i].sh_size; 384 } 385 386 /* Update all symbol values with the offset. */ 387 for (j = 0; j < ef->ddbsymcnt; j++) { 388 es = &ef->ddbsymtab[j]; 389 if (es->st_shndx != i) 390 continue; 391 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 392 } 393 pb++; 394 break; 395 case SHT_REL: 396 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 397 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 398 ef->reltab[rl].sec = shdr[i].sh_info; 399 rl++; 400 break; 401 case SHT_RELA: 402 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 403 ef->relatab[ra].nrela = 404 shdr[i].sh_size / sizeof(Elf_Rela); 405 ef->relatab[ra].sec = shdr[i].sh_info; 406 ra++; 407 break; 408 } 409 } 410 if (pb != ef->nprogtab) { 411 printf("%s: lost progbits\n", filename); 412 error = ENOEXEC; 413 goto out; 414 } 415 if (rl != ef->nreltab) { 416 printf("%s: lost reltab\n", filename); 417 error = ENOEXEC; 418 goto out; 419 } 420 if (ra != ef->nrelatab) { 421 printf("%s: lost relatab\n", filename); 422 error = ENOEXEC; 423 goto out; 424 } 425 426 /* Local intra-module relocations */ 427 error = link_elf_reloc_local(lf); 428 if (error != 0) 429 goto out; 430 431 *result = lf; 432 return (0); 433 434 out: 435 /* preload not done this way */ 436 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 437 return (error); 438 } 439 440 static void 441 link_elf_invoke_ctors(caddr_t addr, size_t size) 442 { 443 void (**ctor)(void); 444 size_t i, cnt; 445 446 if (addr == NULL || size == 0) 447 return; 448 cnt = size / sizeof(*ctor); 449 ctor = (void *)addr; 450 for (i = 0; i < cnt; i++) { 451 if (ctor[i] != NULL) 452 (*ctor[i])(); 453 } 454 } 455 456 static int 457 link_elf_link_preload_finish(linker_file_t lf) 458 { 459 elf_file_t ef; 460 int error; 461 462 ef = (elf_file_t)lf; 463 error = relocate_file(ef); 464 if (error) 465 return error; 466 467 /* Notify MD code that a module is being loaded. */ 468 error = elf_cpu_load_file(lf); 469 if (error) 470 return (error); 471 472 /* Invoke .ctors */ 473 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 474 return (0); 475 } 476 477 static int 478 link_elf_load_file(linker_class_t cls, const char *filename, 479 linker_file_t *result) 480 { 481 struct nameidata *nd; 482 struct thread *td = curthread; /* XXX */ 483 Elf_Ehdr *hdr; 484 Elf_Shdr *shdr; 485 Elf_Sym *es; 486 int nbytes, i, j; 487 vm_offset_t mapbase; 488 size_t mapsize; 489 int error = 0; 490 ssize_t resid; 491 int flags; 492 elf_file_t ef; 493 linker_file_t lf; 494 int symtabindex; 495 int symstrindex; 496 int shstrindex; 497 int nsym; 498 int pb, rl, ra; 499 int alignmask; 500 501 shdr = NULL; 502 lf = NULL; 503 mapsize = 0; 504 hdr = NULL; 505 506 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 507 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 508 flags = FREAD; 509 error = vn_open(nd, &flags, 0, NULL); 510 if (error) { 511 free(nd, M_TEMP); 512 return error; 513 } 514 NDFREE(nd, NDF_ONLY_PNBUF); 515 if (nd->ni_vp->v_type != VREG) { 516 error = ENOEXEC; 517 goto out; 518 } 519 #ifdef MAC 520 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 521 if (error) { 522 goto out; 523 } 524 #endif 525 526 /* Read the elf header from the file. */ 527 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 528 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 529 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 530 &resid, td); 531 if (error) 532 goto out; 533 if (resid != 0){ 534 error = ENOEXEC; 535 goto out; 536 } 537 538 if (!IS_ELF(*hdr)) { 539 error = ENOEXEC; 540 goto out; 541 } 542 543 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 544 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 545 link_elf_error(filename, "Unsupported file layout"); 546 error = ENOEXEC; 547 goto out; 548 } 549 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 550 || hdr->e_version != EV_CURRENT) { 551 link_elf_error(filename, "Unsupported file version"); 552 error = ENOEXEC; 553 goto out; 554 } 555 if (hdr->e_type != ET_REL) { 556 error = ENOSYS; 557 goto out; 558 } 559 if (hdr->e_machine != ELF_TARG_MACH) { 560 link_elf_error(filename, "Unsupported machine"); 561 error = ENOEXEC; 562 goto out; 563 } 564 565 lf = linker_make_file(filename, &link_elf_class); 566 if (!lf) { 567 error = ENOMEM; 568 goto out; 569 } 570 ef = (elf_file_t) lf; 571 ef->nprogtab = 0; 572 ef->e_shdr = 0; 573 ef->nreltab = 0; 574 ef->nrelatab = 0; 575 576 /* Allocate and read in the section header */ 577 nbytes = hdr->e_shnum * hdr->e_shentsize; 578 if (nbytes == 0 || hdr->e_shoff == 0 || 579 hdr->e_shentsize != sizeof(Elf_Shdr)) { 580 error = ENOEXEC; 581 goto out; 582 } 583 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 584 ef->e_shdr = shdr; 585 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 586 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 587 NOCRED, &resid, td); 588 if (error) 589 goto out; 590 if (resid) { 591 error = ENOEXEC; 592 goto out; 593 } 594 595 /* Scan the section header for information and table sizing. */ 596 nsym = 0; 597 symtabindex = -1; 598 symstrindex = -1; 599 for (i = 0; i < hdr->e_shnum; i++) { 600 if (shdr[i].sh_size == 0) 601 continue; 602 switch (shdr[i].sh_type) { 603 case SHT_PROGBITS: 604 case SHT_NOBITS: 605 #ifdef __amd64__ 606 case SHT_X86_64_UNWIND: 607 #endif 608 ef->nprogtab++; 609 break; 610 case SHT_SYMTAB: 611 nsym++; 612 symtabindex = i; 613 symstrindex = shdr[i].sh_link; 614 break; 615 case SHT_REL: 616 ef->nreltab++; 617 break; 618 case SHT_RELA: 619 ef->nrelatab++; 620 break; 621 case SHT_STRTAB: 622 break; 623 } 624 } 625 if (ef->nprogtab == 0) { 626 link_elf_error(filename, "file has no contents"); 627 error = ENOEXEC; 628 goto out; 629 } 630 if (nsym != 1) { 631 /* Only allow one symbol table for now */ 632 link_elf_error(filename, "file has no valid symbol table"); 633 error = ENOEXEC; 634 goto out; 635 } 636 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 637 shdr[symstrindex].sh_type != SHT_STRTAB) { 638 link_elf_error(filename, "file has invalid symbol strings"); 639 error = ENOEXEC; 640 goto out; 641 } 642 643 /* Allocate space for tracking the load chunks */ 644 if (ef->nprogtab != 0) 645 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 646 M_LINKER, M_WAITOK | M_ZERO); 647 if (ef->nreltab != 0) 648 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 649 M_LINKER, M_WAITOK | M_ZERO); 650 if (ef->nrelatab != 0) 651 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 652 M_LINKER, M_WAITOK | M_ZERO); 653 654 if (symtabindex == -1) { 655 link_elf_error(filename, "lost symbol table index"); 656 error = ENOEXEC; 657 goto out; 658 } 659 /* Allocate space for and load the symbol table */ 660 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 661 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 662 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 663 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 664 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 665 &resid, td); 666 if (error) 667 goto out; 668 if (resid != 0){ 669 error = EINVAL; 670 goto out; 671 } 672 673 if (symstrindex == -1) { 674 link_elf_error(filename, "lost symbol string index"); 675 error = ENOEXEC; 676 goto out; 677 } 678 /* Allocate space for and load the symbol strings */ 679 ef->ddbstrcnt = shdr[symstrindex].sh_size; 680 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 681 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 682 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 683 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 684 &resid, td); 685 if (error) 686 goto out; 687 if (resid != 0){ 688 error = EINVAL; 689 goto out; 690 } 691 692 /* Do we have a string table for the section names? */ 693 shstrindex = -1; 694 if (hdr->e_shstrndx != 0 && 695 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 696 shstrindex = hdr->e_shstrndx; 697 ef->shstrcnt = shdr[shstrindex].sh_size; 698 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 699 M_WAITOK); 700 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 701 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 702 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 703 &resid, td); 704 if (error) 705 goto out; 706 if (resid != 0){ 707 error = EINVAL; 708 goto out; 709 } 710 } 711 712 /* Size up code/data(progbits) and bss(nobits). */ 713 alignmask = 0; 714 for (i = 0; i < hdr->e_shnum; i++) { 715 if (shdr[i].sh_size == 0) 716 continue; 717 switch (shdr[i].sh_type) { 718 case SHT_PROGBITS: 719 case SHT_NOBITS: 720 #ifdef __amd64__ 721 case SHT_X86_64_UNWIND: 722 #endif 723 alignmask = shdr[i].sh_addralign - 1; 724 mapsize += alignmask; 725 mapsize &= ~alignmask; 726 mapsize += shdr[i].sh_size; 727 break; 728 } 729 } 730 731 /* 732 * We know how much space we need for the text/data/bss/etc. 733 * This stuff needs to be in a single chunk so that profiling etc 734 * can get the bounds and gdb can associate offsets with modules 735 */ 736 ef->object = vm_object_allocate(OBJT_DEFAULT, 737 round_page(mapsize) >> PAGE_SHIFT); 738 if (ef->object == NULL) { 739 error = ENOMEM; 740 goto out; 741 } 742 ef->address = (caddr_t) vm_map_min(kernel_map); 743 744 /* 745 * In order to satisfy amd64's architectural requirements on the 746 * location of code and data in the kernel's address space, request a 747 * mapping that is above the kernel. 748 */ 749 #ifdef __amd64__ 750 mapbase = KERNBASE; 751 #else 752 mapbase = VM_MIN_KERNEL_ADDRESS; 753 #endif 754 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 755 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 756 VM_PROT_ALL, 0); 757 if (error) { 758 vm_object_deallocate(ef->object); 759 ef->object = 0; 760 goto out; 761 } 762 763 /* Wire the pages */ 764 error = vm_map_wire(kernel_map, mapbase, 765 mapbase + round_page(mapsize), 766 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 767 if (error != KERN_SUCCESS) { 768 error = ENOMEM; 769 goto out; 770 } 771 772 /* Inform the kld system about the situation */ 773 lf->address = ef->address = (caddr_t)mapbase; 774 lf->size = mapsize; 775 776 /* 777 * Now load code/data(progbits), zero bss(nobits), allocate space for 778 * and load relocs 779 */ 780 pb = 0; 781 rl = 0; 782 ra = 0; 783 alignmask = 0; 784 for (i = 0; i < hdr->e_shnum; i++) { 785 if (shdr[i].sh_size == 0) 786 continue; 787 switch (shdr[i].sh_type) { 788 case SHT_PROGBITS: 789 case SHT_NOBITS: 790 #ifdef __amd64__ 791 case SHT_X86_64_UNWIND: 792 #endif 793 alignmask = shdr[i].sh_addralign - 1; 794 mapbase += alignmask; 795 mapbase &= ~alignmask; 796 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 797 ef->progtab[pb].name = 798 ef->shstrtab + shdr[i].sh_name; 799 if (!strcmp(ef->progtab[pb].name, ".ctors")) { 800 lf->ctors_addr = (caddr_t)mapbase; 801 lf->ctors_size = shdr[i].sh_size; 802 } 803 } else if (shdr[i].sh_type == SHT_PROGBITS) 804 ef->progtab[pb].name = "<<PROGBITS>>"; 805 #ifdef __amd64__ 806 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 807 ef->progtab[pb].name = "<<UNWIND>>"; 808 #endif 809 else 810 ef->progtab[pb].name = "<<NOBITS>>"; 811 if (ef->progtab[pb].name != NULL && 812 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 813 ef->progtab[pb].addr = 814 dpcpu_alloc(shdr[i].sh_size); 815 #ifdef VIMAGE 816 else if (ef->progtab[pb].name != NULL && 817 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 818 ef->progtab[pb].addr = 819 vnet_data_alloc(shdr[i].sh_size); 820 #endif 821 else 822 ef->progtab[pb].addr = 823 (void *)(uintptr_t)mapbase; 824 if (ef->progtab[pb].addr == NULL) { 825 error = ENOSPC; 826 goto out; 827 } 828 ef->progtab[pb].size = shdr[i].sh_size; 829 ef->progtab[pb].sec = i; 830 if (shdr[i].sh_type == SHT_PROGBITS 831 #ifdef __amd64__ 832 || shdr[i].sh_type == SHT_X86_64_UNWIND 833 #endif 834 ) { 835 error = vn_rdwr(UIO_READ, nd->ni_vp, 836 ef->progtab[pb].addr, 837 shdr[i].sh_size, shdr[i].sh_offset, 838 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 839 NOCRED, &resid, td); 840 if (error) 841 goto out; 842 if (resid != 0){ 843 error = EINVAL; 844 goto out; 845 } 846 /* Initialize the per-cpu or vnet area. */ 847 if (ef->progtab[pb].addr != (void *)mapbase && 848 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 849 dpcpu_copy(ef->progtab[pb].addr, 850 shdr[i].sh_size); 851 #ifdef VIMAGE 852 else if (ef->progtab[pb].addr != 853 (void *)mapbase && 854 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 855 vnet_data_copy(ef->progtab[pb].addr, 856 shdr[i].sh_size); 857 #endif 858 } else 859 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 860 861 /* Update all symbol values with the offset. */ 862 for (j = 0; j < ef->ddbsymcnt; j++) { 863 es = &ef->ddbsymtab[j]; 864 if (es->st_shndx != i) 865 continue; 866 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 867 } 868 mapbase += shdr[i].sh_size; 869 pb++; 870 break; 871 case SHT_REL: 872 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 873 M_WAITOK); 874 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 875 ef->reltab[rl].sec = shdr[i].sh_info; 876 error = vn_rdwr(UIO_READ, nd->ni_vp, 877 (void *)ef->reltab[rl].rel, 878 shdr[i].sh_size, shdr[i].sh_offset, 879 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 880 &resid, td); 881 if (error) 882 goto out; 883 if (resid != 0){ 884 error = EINVAL; 885 goto out; 886 } 887 rl++; 888 break; 889 case SHT_RELA: 890 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 891 M_WAITOK); 892 ef->relatab[ra].nrela = 893 shdr[i].sh_size / sizeof(Elf_Rela); 894 ef->relatab[ra].sec = shdr[i].sh_info; 895 error = vn_rdwr(UIO_READ, nd->ni_vp, 896 (void *)ef->relatab[ra].rela, 897 shdr[i].sh_size, shdr[i].sh_offset, 898 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 899 &resid, td); 900 if (error) 901 goto out; 902 if (resid != 0){ 903 error = EINVAL; 904 goto out; 905 } 906 ra++; 907 break; 908 } 909 } 910 if (pb != ef->nprogtab) { 911 link_elf_error(filename, "lost progbits"); 912 error = ENOEXEC; 913 goto out; 914 } 915 if (rl != ef->nreltab) { 916 link_elf_error(filename, "lost reltab"); 917 error = ENOEXEC; 918 goto out; 919 } 920 if (ra != ef->nrelatab) { 921 link_elf_error(filename, "lost relatab"); 922 error = ENOEXEC; 923 goto out; 924 } 925 if (mapbase != (vm_offset_t)ef->address + mapsize) { 926 printf( 927 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 928 filename != NULL ? filename : "<none>", 929 (u_long)mapbase, ef->address, (u_long)mapsize, 930 (u_long)(vm_offset_t)ef->address + mapsize); 931 error = ENOMEM; 932 goto out; 933 } 934 935 /* Local intra-module relocations */ 936 error = link_elf_reloc_local(lf); 937 if (error != 0) 938 goto out; 939 940 /* Pull in dependencies */ 941 VOP_UNLOCK(nd->ni_vp, 0); 942 error = linker_load_dependencies(lf); 943 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 944 if (error) 945 goto out; 946 947 /* External relocations */ 948 error = relocate_file(ef); 949 if (error) 950 goto out; 951 952 /* Notify MD code that a module is being loaded. */ 953 error = elf_cpu_load_file(lf); 954 if (error) 955 goto out; 956 957 /* Invoke .ctors */ 958 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 959 960 *result = lf; 961 962 out: 963 VOP_UNLOCK(nd->ni_vp, 0); 964 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 965 free(nd, M_TEMP); 966 if (error && lf) 967 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 968 free(hdr, M_LINKER); 969 970 return error; 971 } 972 973 static void 974 link_elf_unload_file(linker_file_t file) 975 { 976 elf_file_t ef = (elf_file_t) file; 977 int i; 978 979 /* Notify MD code that a module is being unloaded. */ 980 elf_cpu_unload_file(file); 981 982 if (ef->progtab) { 983 for (i = 0; i < ef->nprogtab; i++) { 984 if (ef->progtab[i].size == 0) 985 continue; 986 if (ef->progtab[i].name == NULL) 987 continue; 988 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 989 dpcpu_free(ef->progtab[i].addr, 990 ef->progtab[i].size); 991 #ifdef VIMAGE 992 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 993 vnet_data_free(ef->progtab[i].addr, 994 ef->progtab[i].size); 995 #endif 996 } 997 } 998 if (ef->preloaded) { 999 free(ef->reltab, M_LINKER); 1000 free(ef->relatab, M_LINKER); 1001 free(ef->progtab, M_LINKER); 1002 free(ef->ctftab, M_LINKER); 1003 free(ef->ctfoff, M_LINKER); 1004 free(ef->typoff, M_LINKER); 1005 if (file->filename != NULL) 1006 preload_delete_name(file->filename); 1007 /* XXX reclaim module memory? */ 1008 return; 1009 } 1010 1011 for (i = 0; i < ef->nreltab; i++) 1012 free(ef->reltab[i].rel, M_LINKER); 1013 for (i = 0; i < ef->nrelatab; i++) 1014 free(ef->relatab[i].rela, M_LINKER); 1015 free(ef->reltab, M_LINKER); 1016 free(ef->relatab, M_LINKER); 1017 free(ef->progtab, M_LINKER); 1018 1019 if (ef->object) { 1020 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1021 (vm_offset_t) ef->address + 1022 (ef->object->size << PAGE_SHIFT)); 1023 } 1024 free(ef->e_shdr, M_LINKER); 1025 free(ef->ddbsymtab, M_LINKER); 1026 free(ef->ddbstrtab, M_LINKER); 1027 free(ef->shstrtab, M_LINKER); 1028 free(ef->ctftab, M_LINKER); 1029 free(ef->ctfoff, M_LINKER); 1030 free(ef->typoff, M_LINKER); 1031 } 1032 1033 static const char * 1034 symbol_name(elf_file_t ef, Elf_Size r_info) 1035 { 1036 const Elf_Sym *ref; 1037 1038 if (ELF_R_SYM(r_info)) { 1039 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1040 return ef->ddbstrtab + ref->st_name; 1041 } else 1042 return NULL; 1043 } 1044 1045 static Elf_Addr 1046 findbase(elf_file_t ef, int sec) 1047 { 1048 int i; 1049 Elf_Addr base = 0; 1050 1051 for (i = 0; i < ef->nprogtab; i++) { 1052 if (sec == ef->progtab[i].sec) { 1053 base = (Elf_Addr)ef->progtab[i].addr; 1054 break; 1055 } 1056 } 1057 return base; 1058 } 1059 1060 static int 1061 relocate_file(elf_file_t ef) 1062 { 1063 const Elf_Rel *rellim; 1064 const Elf_Rel *rel; 1065 const Elf_Rela *relalim; 1066 const Elf_Rela *rela; 1067 const char *symname; 1068 const Elf_Sym *sym; 1069 int i; 1070 Elf_Size symidx; 1071 Elf_Addr base; 1072 1073 1074 /* Perform relocations without addend if there are any: */ 1075 for (i = 0; i < ef->nreltab; i++) { 1076 rel = ef->reltab[i].rel; 1077 if (rel == NULL) { 1078 link_elf_error(ef->lf.filename, "lost a reltab!"); 1079 return (ENOEXEC); 1080 } 1081 rellim = rel + ef->reltab[i].nrel; 1082 base = findbase(ef, ef->reltab[i].sec); 1083 if (base == 0) { 1084 link_elf_error(ef->lf.filename, "lost base for reltab"); 1085 return (ENOEXEC); 1086 } 1087 for ( ; rel < rellim; rel++) { 1088 symidx = ELF_R_SYM(rel->r_info); 1089 if (symidx >= ef->ddbsymcnt) 1090 continue; 1091 sym = ef->ddbsymtab + symidx; 1092 /* Local relocs are already done */ 1093 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1094 continue; 1095 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1096 elf_obj_lookup)) { 1097 symname = symbol_name(ef, rel->r_info); 1098 printf("link_elf_obj: symbol %s undefined\n", 1099 symname); 1100 return (ENOENT); 1101 } 1102 } 1103 } 1104 1105 /* Perform relocations with addend if there are any: */ 1106 for (i = 0; i < ef->nrelatab; i++) { 1107 rela = ef->relatab[i].rela; 1108 if (rela == NULL) { 1109 link_elf_error(ef->lf.filename, "lost a relatab!"); 1110 return (ENOEXEC); 1111 } 1112 relalim = rela + ef->relatab[i].nrela; 1113 base = findbase(ef, ef->relatab[i].sec); 1114 if (base == 0) { 1115 link_elf_error(ef->lf.filename, 1116 "lost base for relatab"); 1117 return (ENOEXEC); 1118 } 1119 for ( ; rela < relalim; rela++) { 1120 symidx = ELF_R_SYM(rela->r_info); 1121 if (symidx >= ef->ddbsymcnt) 1122 continue; 1123 sym = ef->ddbsymtab + symidx; 1124 /* Local relocs are already done */ 1125 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1126 continue; 1127 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1128 elf_obj_lookup)) { 1129 symname = symbol_name(ef, rela->r_info); 1130 printf("link_elf_obj: symbol %s undefined\n", 1131 symname); 1132 return (ENOENT); 1133 } 1134 } 1135 } 1136 1137 /* 1138 * Only clean SHN_FBSD_CACHED for successful return. If we 1139 * modified symbol table for the object but found an 1140 * unresolved symbol, there is no reason to roll back. 1141 */ 1142 elf_obj_cleanup_globals_cache(ef); 1143 1144 return (0); 1145 } 1146 1147 static int 1148 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1149 { 1150 elf_file_t ef = (elf_file_t) lf; 1151 const Elf_Sym *symp; 1152 const char *strp; 1153 int i; 1154 1155 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1156 strp = ef->ddbstrtab + symp->st_name; 1157 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1158 *sym = (c_linker_sym_t) symp; 1159 return 0; 1160 } 1161 } 1162 return ENOENT; 1163 } 1164 1165 static int 1166 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1167 linker_symval_t *symval) 1168 { 1169 elf_file_t ef = (elf_file_t) lf; 1170 const Elf_Sym *es = (const Elf_Sym*) sym; 1171 1172 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1173 symval->name = ef->ddbstrtab + es->st_name; 1174 symval->value = (caddr_t)es->st_value; 1175 symval->size = es->st_size; 1176 return 0; 1177 } 1178 return ENOENT; 1179 } 1180 1181 static int 1182 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1183 c_linker_sym_t *sym, long *diffp) 1184 { 1185 elf_file_t ef = (elf_file_t) lf; 1186 u_long off = (uintptr_t) (void *) value; 1187 u_long diff = off; 1188 u_long st_value; 1189 const Elf_Sym *es; 1190 const Elf_Sym *best = NULL; 1191 int i; 1192 1193 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1194 if (es->st_name == 0) 1195 continue; 1196 st_value = es->st_value; 1197 if (off >= st_value) { 1198 if (off - st_value < diff) { 1199 diff = off - st_value; 1200 best = es; 1201 if (diff == 0) 1202 break; 1203 } else if (off - st_value == diff) { 1204 best = es; 1205 } 1206 } 1207 } 1208 if (best == NULL) 1209 *diffp = off; 1210 else 1211 *diffp = diff; 1212 *sym = (c_linker_sym_t) best; 1213 1214 return 0; 1215 } 1216 1217 /* 1218 * Look up a linker set on an ELF system. 1219 */ 1220 static int 1221 link_elf_lookup_set(linker_file_t lf, const char *name, 1222 void ***startp, void ***stopp, int *countp) 1223 { 1224 elf_file_t ef = (elf_file_t)lf; 1225 void **start, **stop; 1226 int i, count; 1227 1228 /* Relative to section number */ 1229 for (i = 0; i < ef->nprogtab; i++) { 1230 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1231 strcmp(ef->progtab[i].name + 4, name) == 0) { 1232 start = (void **)ef->progtab[i].addr; 1233 stop = (void **)((char *)ef->progtab[i].addr + 1234 ef->progtab[i].size); 1235 count = stop - start; 1236 if (startp) 1237 *startp = start; 1238 if (stopp) 1239 *stopp = stop; 1240 if (countp) 1241 *countp = count; 1242 return (0); 1243 } 1244 } 1245 return (ESRCH); 1246 } 1247 1248 static int 1249 link_elf_each_function_name(linker_file_t file, 1250 int (*callback)(const char *, void *), void *opaque) 1251 { 1252 elf_file_t ef = (elf_file_t)file; 1253 const Elf_Sym *symp; 1254 int i, error; 1255 1256 /* Exhaustive search */ 1257 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1258 if (symp->st_value != 0 && 1259 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1260 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1261 if (error) 1262 return (error); 1263 } 1264 } 1265 return (0); 1266 } 1267 1268 static int 1269 link_elf_each_function_nameval(linker_file_t file, 1270 linker_function_nameval_callback_t callback, void *opaque) 1271 { 1272 linker_symval_t symval; 1273 elf_file_t ef = (elf_file_t)file; 1274 const Elf_Sym* symp; 1275 int i, error; 1276 1277 /* Exhaustive search */ 1278 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1279 if (symp->st_value != 0 && 1280 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1281 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1282 if (error) 1283 return (error); 1284 error = callback(file, i, &symval, opaque); 1285 if (error) 1286 return (error); 1287 } 1288 } 1289 return (0); 1290 } 1291 1292 static void 1293 elf_obj_cleanup_globals_cache(elf_file_t ef) 1294 { 1295 Elf_Sym *sym; 1296 Elf_Size i; 1297 1298 for (i = 0; i < ef->ddbsymcnt; i++) { 1299 sym = ef->ddbsymtab + i; 1300 if (sym->st_shndx == SHN_FBSD_CACHED) { 1301 sym->st_shndx = SHN_UNDEF; 1302 sym->st_value = 0; 1303 } 1304 } 1305 } 1306 1307 /* 1308 * Symbol lookup function that can be used when the symbol index is known (ie 1309 * in relocations). It uses the symbol index instead of doing a fully fledged 1310 * hash table based lookup when such is valid. For example for local symbols. 1311 * This is not only more efficient, it's also more correct. It's not always 1312 * the case that the symbol can be found through the hash table. 1313 */ 1314 static int 1315 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1316 { 1317 elf_file_t ef = (elf_file_t)lf; 1318 Elf_Sym *sym; 1319 const char *symbol; 1320 Elf_Addr res1; 1321 1322 /* Don't even try to lookup the symbol if the index is bogus. */ 1323 if (symidx >= ef->ddbsymcnt) { 1324 *res = 0; 1325 return (EINVAL); 1326 } 1327 1328 sym = ef->ddbsymtab + symidx; 1329 1330 /* Quick answer if there is a definition included. */ 1331 if (sym->st_shndx != SHN_UNDEF) { 1332 *res = sym->st_value; 1333 return (0); 1334 } 1335 1336 /* If we get here, then it is undefined and needs a lookup. */ 1337 switch (ELF_ST_BIND(sym->st_info)) { 1338 case STB_LOCAL: 1339 /* Local, but undefined? huh? */ 1340 *res = 0; 1341 return (EINVAL); 1342 1343 case STB_GLOBAL: 1344 case STB_WEAK: 1345 /* Relative to Data or Function name */ 1346 symbol = ef->ddbstrtab + sym->st_name; 1347 1348 /* Force a lookup failure if the symbol name is bogus. */ 1349 if (*symbol == 0) { 1350 *res = 0; 1351 return (EINVAL); 1352 } 1353 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1354 1355 /* 1356 * Cache global lookups during module relocation. The failure 1357 * case is particularly expensive for callers, who must scan 1358 * through the entire globals table doing strcmp(). Cache to 1359 * avoid doing such work repeatedly. 1360 * 1361 * After relocation is complete, undefined globals will be 1362 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1363 * above. 1364 */ 1365 if (res1 != 0) { 1366 sym->st_shndx = SHN_FBSD_CACHED; 1367 sym->st_value = res1; 1368 *res = res1; 1369 return (0); 1370 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1371 sym->st_value = 0; 1372 *res = 0; 1373 return (0); 1374 } 1375 return (EINVAL); 1376 1377 default: 1378 return (EINVAL); 1379 } 1380 } 1381 1382 static void 1383 link_elf_fix_link_set(elf_file_t ef) 1384 { 1385 static const char startn[] = "__start_"; 1386 static const char stopn[] = "__stop_"; 1387 Elf_Sym *sym; 1388 const char *sym_name, *linkset_name; 1389 Elf_Addr startp, stopp; 1390 Elf_Size symidx; 1391 int start, i; 1392 1393 startp = stopp = 0; 1394 for (symidx = 1 /* zero entry is special */; 1395 symidx < ef->ddbsymcnt; symidx++) { 1396 sym = ef->ddbsymtab + symidx; 1397 if (sym->st_shndx != SHN_UNDEF) 1398 continue; 1399 1400 sym_name = ef->ddbstrtab + sym->st_name; 1401 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1402 start = 1; 1403 linkset_name = sym_name + sizeof(startn) - 1; 1404 } 1405 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1406 start = 0; 1407 linkset_name = sym_name + sizeof(stopn) - 1; 1408 } 1409 else 1410 continue; 1411 1412 for (i = 0; i < ef->nprogtab; i++) { 1413 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1414 startp = (Elf_Addr)ef->progtab[i].addr; 1415 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1416 break; 1417 } 1418 } 1419 if (i == ef->nprogtab) 1420 continue; 1421 1422 sym->st_value = start ? startp : stopp; 1423 sym->st_shndx = i; 1424 } 1425 } 1426 1427 static int 1428 link_elf_reloc_local(linker_file_t lf) 1429 { 1430 elf_file_t ef = (elf_file_t)lf; 1431 const Elf_Rel *rellim; 1432 const Elf_Rel *rel; 1433 const Elf_Rela *relalim; 1434 const Elf_Rela *rela; 1435 const Elf_Sym *sym; 1436 Elf_Addr base; 1437 int i; 1438 Elf_Size symidx; 1439 1440 link_elf_fix_link_set(ef); 1441 1442 /* Perform relocations without addend if there are any: */ 1443 for (i = 0; i < ef->nreltab; i++) { 1444 rel = ef->reltab[i].rel; 1445 if (rel == NULL) { 1446 link_elf_error(ef->lf.filename, "lost a reltab"); 1447 return (ENOEXEC); 1448 } 1449 rellim = rel + ef->reltab[i].nrel; 1450 base = findbase(ef, ef->reltab[i].sec); 1451 if (base == 0) { 1452 link_elf_error(ef->lf.filename, "lost base for reltab"); 1453 return (ENOEXEC); 1454 } 1455 for ( ; rel < rellim; rel++) { 1456 symidx = ELF_R_SYM(rel->r_info); 1457 if (symidx >= ef->ddbsymcnt) 1458 continue; 1459 sym = ef->ddbsymtab + symidx; 1460 /* Only do local relocs */ 1461 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1462 continue; 1463 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1464 elf_obj_lookup); 1465 } 1466 } 1467 1468 /* Perform relocations with addend if there are any: */ 1469 for (i = 0; i < ef->nrelatab; i++) { 1470 rela = ef->relatab[i].rela; 1471 if (rela == NULL) { 1472 link_elf_error(ef->lf.filename, "lost a relatab!"); 1473 return (ENOEXEC); 1474 } 1475 relalim = rela + ef->relatab[i].nrela; 1476 base = findbase(ef, ef->relatab[i].sec); 1477 if (base == 0) { 1478 link_elf_error(ef->lf.filename, "lost base for reltab"); 1479 return (ENOEXEC); 1480 } 1481 for ( ; rela < relalim; rela++) { 1482 symidx = ELF_R_SYM(rela->r_info); 1483 if (symidx >= ef->ddbsymcnt) 1484 continue; 1485 sym = ef->ddbsymtab + symidx; 1486 /* Only do local relocs */ 1487 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1488 continue; 1489 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1490 elf_obj_lookup); 1491 } 1492 } 1493 return (0); 1494 } 1495 1496 static long 1497 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1498 { 1499 elf_file_t ef = (elf_file_t)lf; 1500 1501 *symtab = ef->ddbsymtab; 1502 1503 if (*symtab == NULL) 1504 return (0); 1505 1506 return (ef->ddbsymcnt); 1507 } 1508 1509 static long 1510 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1511 { 1512 elf_file_t ef = (elf_file_t)lf; 1513 1514 *strtab = ef->ddbstrtab; 1515 1516 if (*strtab == NULL) 1517 return (0); 1518 1519 return (ef->ddbstrcnt); 1520 } 1521