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 u_int nprogtab; 101 102 Elf_relaent *relatab; 103 u_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 /* Ignore sections not loaded by the loader. */ 266 if (shdr[i].sh_addr == 0) 267 break; 268 ef->nprogtab++; 269 break; 270 case SHT_SYMTAB: 271 symtabindex = i; 272 symstrindex = shdr[i].sh_link; 273 break; 274 case SHT_REL: 275 ef->nreltab++; 276 break; 277 case SHT_RELA: 278 ef->nrelatab++; 279 break; 280 } 281 } 282 283 shstrindex = hdr->e_shstrndx; 284 if (ef->nprogtab == 0 || symstrindex < 0 || 285 symstrindex >= hdr->e_shnum || 286 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 287 shstrindex >= hdr->e_shnum || 288 shdr[shstrindex].sh_type != SHT_STRTAB) { 289 printf("%s: bad/missing section headers\n", filename); 290 error = ENOEXEC; 291 goto out; 292 } 293 294 /* Allocate space for tracking the load chunks */ 295 if (ef->nprogtab != 0) 296 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 297 M_LINKER, M_WAITOK | M_ZERO); 298 if (ef->nreltab != 0) 299 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 300 M_LINKER, M_WAITOK | M_ZERO); 301 if (ef->nrelatab != 0) 302 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 303 M_LINKER, M_WAITOK | M_ZERO); 304 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 305 (ef->nreltab != 0 && ef->reltab == NULL) || 306 (ef->nrelatab != 0 && ef->relatab == NULL)) { 307 error = ENOMEM; 308 goto out; 309 } 310 311 /* XXX, relocate the sh_addr fields saved by the loader. */ 312 off = 0; 313 for (i = 0; i < hdr->e_shnum; i++) { 314 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 315 off = shdr[i].sh_addr; 316 } 317 for (i = 0; i < hdr->e_shnum; i++) { 318 if (shdr[i].sh_addr != 0) 319 shdr[i].sh_addr = shdr[i].sh_addr - off + 320 (Elf_Addr)ef->address; 321 } 322 323 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 324 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 325 ef->ddbstrcnt = shdr[symstrindex].sh_size; 326 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 327 ef->shstrcnt = shdr[shstrindex].sh_size; 328 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 329 330 /* Now fill out progtab and the relocation tables. */ 331 pb = 0; 332 rl = 0; 333 ra = 0; 334 for (i = 0; i < hdr->e_shnum; i++) { 335 switch (shdr[i].sh_type) { 336 case SHT_PROGBITS: 337 case SHT_NOBITS: 338 #ifdef __amd64__ 339 case SHT_X86_64_UNWIND: 340 #endif 341 if (shdr[i].sh_addr == 0) 342 break; 343 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 344 if (shdr[i].sh_type == SHT_PROGBITS) 345 ef->progtab[pb].name = "<<PROGBITS>>"; 346 #ifdef __amd64__ 347 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 348 ef->progtab[pb].name = "<<UNWIND>>"; 349 #endif 350 else 351 ef->progtab[pb].name = "<<NOBITS>>"; 352 ef->progtab[pb].size = shdr[i].sh_size; 353 ef->progtab[pb].sec = i; 354 if (ef->shstrtab && shdr[i].sh_name != 0) 355 ef->progtab[pb].name = 356 ef->shstrtab + shdr[i].sh_name; 357 if (ef->progtab[pb].name != NULL && 358 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 359 void *dpcpu; 360 361 dpcpu = dpcpu_alloc(shdr[i].sh_size); 362 if (dpcpu == NULL) { 363 error = ENOSPC; 364 goto out; 365 } 366 memcpy(dpcpu, ef->progtab[pb].addr, 367 ef->progtab[pb].size); 368 dpcpu_copy(dpcpu, shdr[i].sh_size); 369 ef->progtab[pb].addr = dpcpu; 370 #ifdef VIMAGE 371 } else if (ef->progtab[pb].name != NULL && 372 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 373 void *vnet_data; 374 375 vnet_data = vnet_data_alloc(shdr[i].sh_size); 376 if (vnet_data == NULL) { 377 error = ENOSPC; 378 goto out; 379 } 380 memcpy(vnet_data, ef->progtab[pb].addr, 381 ef->progtab[pb].size); 382 vnet_data_copy(vnet_data, shdr[i].sh_size); 383 ef->progtab[pb].addr = vnet_data; 384 #endif 385 } else if (ef->progtab[pb].name != NULL && 386 !strcmp(ef->progtab[pb].name, ".ctors")) { 387 lf->ctors_addr = ef->progtab[pb].addr; 388 lf->ctors_size = shdr[i].sh_size; 389 } 390 391 /* Update all symbol values with the offset. */ 392 for (j = 0; j < ef->ddbsymcnt; j++) { 393 es = &ef->ddbsymtab[j]; 394 if (es->st_shndx != i) 395 continue; 396 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 397 } 398 pb++; 399 break; 400 case SHT_REL: 401 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 402 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 403 ef->reltab[rl].sec = shdr[i].sh_info; 404 rl++; 405 break; 406 case SHT_RELA: 407 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 408 ef->relatab[ra].nrela = 409 shdr[i].sh_size / sizeof(Elf_Rela); 410 ef->relatab[ra].sec = shdr[i].sh_info; 411 ra++; 412 break; 413 } 414 } 415 if (pb != ef->nprogtab) { 416 printf("%s: lost progbits\n", filename); 417 error = ENOEXEC; 418 goto out; 419 } 420 if (rl != ef->nreltab) { 421 printf("%s: lost reltab\n", filename); 422 error = ENOEXEC; 423 goto out; 424 } 425 if (ra != ef->nrelatab) { 426 printf("%s: lost relatab\n", filename); 427 error = ENOEXEC; 428 goto out; 429 } 430 431 /* Local intra-module relocations */ 432 error = link_elf_reloc_local(lf); 433 if (error != 0) 434 goto out; 435 436 *result = lf; 437 return (0); 438 439 out: 440 /* preload not done this way */ 441 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 442 return (error); 443 } 444 445 static void 446 link_elf_invoke_ctors(caddr_t addr, size_t size) 447 { 448 void (**ctor)(void); 449 size_t i, cnt; 450 451 if (addr == NULL || size == 0) 452 return; 453 cnt = size / sizeof(*ctor); 454 ctor = (void *)addr; 455 for (i = 0; i < cnt; i++) { 456 if (ctor[i] != NULL) 457 (*ctor[i])(); 458 } 459 } 460 461 static int 462 link_elf_link_preload_finish(linker_file_t lf) 463 { 464 elf_file_t ef; 465 int error; 466 467 ef = (elf_file_t)lf; 468 error = relocate_file(ef); 469 if (error) 470 return error; 471 472 /* Notify MD code that a module is being loaded. */ 473 error = elf_cpu_load_file(lf); 474 if (error) 475 return (error); 476 477 /* Invoke .ctors */ 478 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 479 return (0); 480 } 481 482 static int 483 link_elf_load_file(linker_class_t cls, const char *filename, 484 linker_file_t *result) 485 { 486 struct nameidata *nd; 487 struct thread *td = curthread; /* XXX */ 488 Elf_Ehdr *hdr; 489 Elf_Shdr *shdr; 490 Elf_Sym *es; 491 int nbytes, i, j; 492 vm_offset_t mapbase; 493 size_t mapsize; 494 int error = 0; 495 ssize_t resid; 496 int flags; 497 elf_file_t ef; 498 linker_file_t lf; 499 int symtabindex; 500 int symstrindex; 501 int shstrindex; 502 int nsym; 503 int pb, rl, ra; 504 int alignmask; 505 506 shdr = NULL; 507 lf = NULL; 508 mapsize = 0; 509 hdr = NULL; 510 511 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 512 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 513 flags = FREAD; 514 error = vn_open(nd, &flags, 0, NULL); 515 if (error) { 516 free(nd, M_TEMP); 517 return error; 518 } 519 NDFREE(nd, NDF_ONLY_PNBUF); 520 if (nd->ni_vp->v_type != VREG) { 521 error = ENOEXEC; 522 goto out; 523 } 524 #ifdef MAC 525 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 526 if (error) { 527 goto out; 528 } 529 #endif 530 531 /* Read the elf header from the file. */ 532 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 533 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 534 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 535 &resid, td); 536 if (error) 537 goto out; 538 if (resid != 0){ 539 error = ENOEXEC; 540 goto out; 541 } 542 543 if (!IS_ELF(*hdr)) { 544 error = ENOEXEC; 545 goto out; 546 } 547 548 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 549 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 550 link_elf_error(filename, "Unsupported file layout"); 551 error = ENOEXEC; 552 goto out; 553 } 554 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 555 || hdr->e_version != EV_CURRENT) { 556 link_elf_error(filename, "Unsupported file version"); 557 error = ENOEXEC; 558 goto out; 559 } 560 if (hdr->e_type != ET_REL) { 561 error = ENOSYS; 562 goto out; 563 } 564 if (hdr->e_machine != ELF_TARG_MACH) { 565 link_elf_error(filename, "Unsupported machine"); 566 error = ENOEXEC; 567 goto out; 568 } 569 570 lf = linker_make_file(filename, &link_elf_class); 571 if (!lf) { 572 error = ENOMEM; 573 goto out; 574 } 575 ef = (elf_file_t) lf; 576 ef->nprogtab = 0; 577 ef->e_shdr = 0; 578 ef->nreltab = 0; 579 ef->nrelatab = 0; 580 581 /* Allocate and read in the section header */ 582 nbytes = hdr->e_shnum * hdr->e_shentsize; 583 if (nbytes == 0 || hdr->e_shoff == 0 || 584 hdr->e_shentsize != sizeof(Elf_Shdr)) { 585 error = ENOEXEC; 586 goto out; 587 } 588 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 589 ef->e_shdr = shdr; 590 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 591 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 592 NOCRED, &resid, td); 593 if (error) 594 goto out; 595 if (resid) { 596 error = ENOEXEC; 597 goto out; 598 } 599 600 /* Scan the section header for information and table sizing. */ 601 nsym = 0; 602 symtabindex = -1; 603 symstrindex = -1; 604 for (i = 0; i < hdr->e_shnum; i++) { 605 if (shdr[i].sh_size == 0) 606 continue; 607 switch (shdr[i].sh_type) { 608 case SHT_PROGBITS: 609 case SHT_NOBITS: 610 #ifdef __amd64__ 611 case SHT_X86_64_UNWIND: 612 #endif 613 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 614 break; 615 ef->nprogtab++; 616 break; 617 case SHT_SYMTAB: 618 nsym++; 619 symtabindex = i; 620 symstrindex = shdr[i].sh_link; 621 break; 622 case SHT_REL: 623 ef->nreltab++; 624 break; 625 case SHT_RELA: 626 ef->nrelatab++; 627 break; 628 case SHT_STRTAB: 629 break; 630 } 631 } 632 if (ef->nprogtab == 0) { 633 link_elf_error(filename, "file has no contents"); 634 error = ENOEXEC; 635 goto out; 636 } 637 if (nsym != 1) { 638 /* Only allow one symbol table for now */ 639 link_elf_error(filename, "file has no valid symbol table"); 640 error = ENOEXEC; 641 goto out; 642 } 643 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 644 shdr[symstrindex].sh_type != SHT_STRTAB) { 645 link_elf_error(filename, "file has invalid symbol strings"); 646 error = ENOEXEC; 647 goto out; 648 } 649 650 /* Allocate space for tracking the load chunks */ 651 if (ef->nprogtab != 0) 652 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 653 M_LINKER, M_WAITOK | M_ZERO); 654 if (ef->nreltab != 0) 655 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 656 M_LINKER, M_WAITOK | M_ZERO); 657 if (ef->nrelatab != 0) 658 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 659 M_LINKER, M_WAITOK | M_ZERO); 660 661 if (symtabindex == -1) { 662 link_elf_error(filename, "lost symbol table index"); 663 error = ENOEXEC; 664 goto out; 665 } 666 /* Allocate space for and load the symbol table */ 667 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 668 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 669 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 670 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 671 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 672 &resid, td); 673 if (error) 674 goto out; 675 if (resid != 0){ 676 error = EINVAL; 677 goto out; 678 } 679 680 if (symstrindex == -1) { 681 link_elf_error(filename, "lost symbol string index"); 682 error = ENOEXEC; 683 goto out; 684 } 685 /* Allocate space for and load the symbol strings */ 686 ef->ddbstrcnt = shdr[symstrindex].sh_size; 687 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 688 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 689 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 690 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 691 &resid, td); 692 if (error) 693 goto out; 694 if (resid != 0){ 695 error = EINVAL; 696 goto out; 697 } 698 699 /* Do we have a string table for the section names? */ 700 shstrindex = -1; 701 if (hdr->e_shstrndx != 0 && 702 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 703 shstrindex = hdr->e_shstrndx; 704 ef->shstrcnt = shdr[shstrindex].sh_size; 705 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 706 M_WAITOK); 707 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 708 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 709 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 710 &resid, td); 711 if (error) 712 goto out; 713 if (resid != 0){ 714 error = EINVAL; 715 goto out; 716 } 717 } 718 719 /* Size up code/data(progbits) and bss(nobits). */ 720 alignmask = 0; 721 for (i = 0; i < hdr->e_shnum; i++) { 722 if (shdr[i].sh_size == 0) 723 continue; 724 switch (shdr[i].sh_type) { 725 case SHT_PROGBITS: 726 case SHT_NOBITS: 727 #ifdef __amd64__ 728 case SHT_X86_64_UNWIND: 729 #endif 730 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 731 break; 732 alignmask = shdr[i].sh_addralign - 1; 733 mapsize += alignmask; 734 mapsize &= ~alignmask; 735 mapsize += shdr[i].sh_size; 736 break; 737 } 738 } 739 740 /* 741 * We know how much space we need for the text/data/bss/etc. 742 * This stuff needs to be in a single chunk so that profiling etc 743 * can get the bounds and gdb can associate offsets with modules 744 */ 745 ef->object = vm_object_allocate(OBJT_DEFAULT, 746 round_page(mapsize) >> PAGE_SHIFT); 747 if (ef->object == NULL) { 748 error = ENOMEM; 749 goto out; 750 } 751 ef->address = (caddr_t) vm_map_min(kernel_map); 752 753 /* 754 * In order to satisfy amd64's architectural requirements on the 755 * location of code and data in the kernel's address space, request a 756 * mapping that is above the kernel. 757 */ 758 #ifdef __amd64__ 759 mapbase = KERNBASE; 760 #else 761 mapbase = VM_MIN_KERNEL_ADDRESS; 762 #endif 763 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 764 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 765 VM_PROT_ALL, 0); 766 if (error) { 767 vm_object_deallocate(ef->object); 768 ef->object = 0; 769 goto out; 770 } 771 772 /* Wire the pages */ 773 error = vm_map_wire(kernel_map, mapbase, 774 mapbase + round_page(mapsize), 775 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 776 if (error != KERN_SUCCESS) { 777 error = ENOMEM; 778 goto out; 779 } 780 781 /* Inform the kld system about the situation */ 782 lf->address = ef->address = (caddr_t)mapbase; 783 lf->size = mapsize; 784 785 /* 786 * Now load code/data(progbits), zero bss(nobits), allocate space for 787 * and load relocs 788 */ 789 pb = 0; 790 rl = 0; 791 ra = 0; 792 alignmask = 0; 793 for (i = 0; i < hdr->e_shnum; i++) { 794 if (shdr[i].sh_size == 0) 795 continue; 796 switch (shdr[i].sh_type) { 797 case SHT_PROGBITS: 798 case SHT_NOBITS: 799 #ifdef __amd64__ 800 case SHT_X86_64_UNWIND: 801 #endif 802 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 803 break; 804 alignmask = shdr[i].sh_addralign - 1; 805 mapbase += alignmask; 806 mapbase &= ~alignmask; 807 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 808 ef->progtab[pb].name = 809 ef->shstrtab + shdr[i].sh_name; 810 if (!strcmp(ef->progtab[pb].name, ".ctors")) { 811 lf->ctors_addr = (caddr_t)mapbase; 812 lf->ctors_size = shdr[i].sh_size; 813 } 814 } else if (shdr[i].sh_type == SHT_PROGBITS) 815 ef->progtab[pb].name = "<<PROGBITS>>"; 816 #ifdef __amd64__ 817 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 818 ef->progtab[pb].name = "<<UNWIND>>"; 819 #endif 820 else 821 ef->progtab[pb].name = "<<NOBITS>>"; 822 if (ef->progtab[pb].name != NULL && 823 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 824 ef->progtab[pb].addr = 825 dpcpu_alloc(shdr[i].sh_size); 826 #ifdef VIMAGE 827 else if (ef->progtab[pb].name != NULL && 828 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 829 ef->progtab[pb].addr = 830 vnet_data_alloc(shdr[i].sh_size); 831 #endif 832 else 833 ef->progtab[pb].addr = 834 (void *)(uintptr_t)mapbase; 835 if (ef->progtab[pb].addr == NULL) { 836 error = ENOSPC; 837 goto out; 838 } 839 ef->progtab[pb].size = shdr[i].sh_size; 840 ef->progtab[pb].sec = i; 841 if (shdr[i].sh_type == SHT_PROGBITS 842 #ifdef __amd64__ 843 || shdr[i].sh_type == SHT_X86_64_UNWIND 844 #endif 845 ) { 846 error = vn_rdwr(UIO_READ, nd->ni_vp, 847 ef->progtab[pb].addr, 848 shdr[i].sh_size, shdr[i].sh_offset, 849 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 850 NOCRED, &resid, td); 851 if (error) 852 goto out; 853 if (resid != 0){ 854 error = EINVAL; 855 goto out; 856 } 857 /* Initialize the per-cpu or vnet area. */ 858 if (ef->progtab[pb].addr != (void *)mapbase && 859 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 860 dpcpu_copy(ef->progtab[pb].addr, 861 shdr[i].sh_size); 862 #ifdef VIMAGE 863 else if (ef->progtab[pb].addr != 864 (void *)mapbase && 865 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 866 vnet_data_copy(ef->progtab[pb].addr, 867 shdr[i].sh_size); 868 #endif 869 } else 870 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 871 872 /* Update all symbol values with the offset. */ 873 for (j = 0; j < ef->ddbsymcnt; j++) { 874 es = &ef->ddbsymtab[j]; 875 if (es->st_shndx != i) 876 continue; 877 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 878 } 879 mapbase += shdr[i].sh_size; 880 pb++; 881 break; 882 case SHT_REL: 883 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 884 M_WAITOK); 885 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 886 ef->reltab[rl].sec = shdr[i].sh_info; 887 error = vn_rdwr(UIO_READ, nd->ni_vp, 888 (void *)ef->reltab[rl].rel, 889 shdr[i].sh_size, shdr[i].sh_offset, 890 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 891 &resid, td); 892 if (error) 893 goto out; 894 if (resid != 0){ 895 error = EINVAL; 896 goto out; 897 } 898 rl++; 899 break; 900 case SHT_RELA: 901 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 902 M_WAITOK); 903 ef->relatab[ra].nrela = 904 shdr[i].sh_size / sizeof(Elf_Rela); 905 ef->relatab[ra].sec = shdr[i].sh_info; 906 error = vn_rdwr(UIO_READ, nd->ni_vp, 907 (void *)ef->relatab[ra].rela, 908 shdr[i].sh_size, shdr[i].sh_offset, 909 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 910 &resid, td); 911 if (error) 912 goto out; 913 if (resid != 0){ 914 error = EINVAL; 915 goto out; 916 } 917 ra++; 918 break; 919 } 920 } 921 if (pb != ef->nprogtab) { 922 link_elf_error(filename, "lost progbits"); 923 error = ENOEXEC; 924 goto out; 925 } 926 if (rl != ef->nreltab) { 927 link_elf_error(filename, "lost reltab"); 928 error = ENOEXEC; 929 goto out; 930 } 931 if (ra != ef->nrelatab) { 932 link_elf_error(filename, "lost relatab"); 933 error = ENOEXEC; 934 goto out; 935 } 936 if (mapbase != (vm_offset_t)ef->address + mapsize) { 937 printf( 938 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 939 filename != NULL ? filename : "<none>", 940 (u_long)mapbase, ef->address, (u_long)mapsize, 941 (u_long)(vm_offset_t)ef->address + mapsize); 942 error = ENOMEM; 943 goto out; 944 } 945 946 /* Local intra-module relocations */ 947 error = link_elf_reloc_local(lf); 948 if (error != 0) 949 goto out; 950 951 /* Pull in dependencies */ 952 VOP_UNLOCK(nd->ni_vp, 0); 953 error = linker_load_dependencies(lf); 954 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 955 if (error) 956 goto out; 957 958 /* External relocations */ 959 error = relocate_file(ef); 960 if (error) 961 goto out; 962 963 /* Notify MD code that a module is being loaded. */ 964 error = elf_cpu_load_file(lf); 965 if (error) 966 goto out; 967 968 /* Invoke .ctors */ 969 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 970 971 *result = lf; 972 973 out: 974 VOP_UNLOCK(nd->ni_vp, 0); 975 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 976 free(nd, M_TEMP); 977 if (error && lf) 978 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 979 free(hdr, M_LINKER); 980 981 return error; 982 } 983 984 static void 985 link_elf_unload_file(linker_file_t file) 986 { 987 elf_file_t ef = (elf_file_t) file; 988 u_int i; 989 990 /* Notify MD code that a module is being unloaded. */ 991 elf_cpu_unload_file(file); 992 993 if (ef->progtab) { 994 for (i = 0; i < ef->nprogtab; i++) { 995 if (ef->progtab[i].size == 0) 996 continue; 997 if (ef->progtab[i].name == NULL) 998 continue; 999 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 1000 dpcpu_free(ef->progtab[i].addr, 1001 ef->progtab[i].size); 1002 #ifdef VIMAGE 1003 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 1004 vnet_data_free(ef->progtab[i].addr, 1005 ef->progtab[i].size); 1006 #endif 1007 } 1008 } 1009 if (ef->preloaded) { 1010 free(ef->reltab, M_LINKER); 1011 free(ef->relatab, M_LINKER); 1012 free(ef->progtab, M_LINKER); 1013 free(ef->ctftab, M_LINKER); 1014 free(ef->ctfoff, M_LINKER); 1015 free(ef->typoff, M_LINKER); 1016 if (file->filename != NULL) 1017 preload_delete_name(file->filename); 1018 /* XXX reclaim module memory? */ 1019 return; 1020 } 1021 1022 for (i = 0; i < ef->nreltab; i++) 1023 free(ef->reltab[i].rel, M_LINKER); 1024 for (i = 0; i < ef->nrelatab; i++) 1025 free(ef->relatab[i].rela, M_LINKER); 1026 free(ef->reltab, M_LINKER); 1027 free(ef->relatab, M_LINKER); 1028 free(ef->progtab, M_LINKER); 1029 1030 if (ef->object) { 1031 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1032 (vm_offset_t) ef->address + 1033 (ef->object->size << PAGE_SHIFT)); 1034 } 1035 free(ef->e_shdr, M_LINKER); 1036 free(ef->ddbsymtab, M_LINKER); 1037 free(ef->ddbstrtab, M_LINKER); 1038 free(ef->shstrtab, M_LINKER); 1039 free(ef->ctftab, M_LINKER); 1040 free(ef->ctfoff, M_LINKER); 1041 free(ef->typoff, M_LINKER); 1042 } 1043 1044 static const char * 1045 symbol_name(elf_file_t ef, Elf_Size r_info) 1046 { 1047 const Elf_Sym *ref; 1048 1049 if (ELF_R_SYM(r_info)) { 1050 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1051 return ef->ddbstrtab + ref->st_name; 1052 } else 1053 return NULL; 1054 } 1055 1056 static Elf_Addr 1057 findbase(elf_file_t ef, int sec) 1058 { 1059 int i; 1060 Elf_Addr base = 0; 1061 1062 for (i = 0; i < ef->nprogtab; i++) { 1063 if (sec == ef->progtab[i].sec) { 1064 base = (Elf_Addr)ef->progtab[i].addr; 1065 break; 1066 } 1067 } 1068 return base; 1069 } 1070 1071 static int 1072 relocate_file(elf_file_t ef) 1073 { 1074 const Elf_Rel *rellim; 1075 const Elf_Rel *rel; 1076 const Elf_Rela *relalim; 1077 const Elf_Rela *rela; 1078 const char *symname; 1079 const Elf_Sym *sym; 1080 int i; 1081 Elf_Size symidx; 1082 Elf_Addr base; 1083 1084 1085 /* Perform relocations without addend if there are any: */ 1086 for (i = 0; i < ef->nreltab; i++) { 1087 rel = ef->reltab[i].rel; 1088 if (rel == NULL) { 1089 link_elf_error(ef->lf.filename, "lost a reltab!"); 1090 return (ENOEXEC); 1091 } 1092 rellim = rel + ef->reltab[i].nrel; 1093 base = findbase(ef, ef->reltab[i].sec); 1094 if (base == 0) { 1095 link_elf_error(ef->lf.filename, "lost base for reltab"); 1096 return (ENOEXEC); 1097 } 1098 for ( ; rel < rellim; rel++) { 1099 symidx = ELF_R_SYM(rel->r_info); 1100 if (symidx >= ef->ddbsymcnt) 1101 continue; 1102 sym = ef->ddbsymtab + symidx; 1103 /* Local relocs are already done */ 1104 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1105 continue; 1106 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1107 elf_obj_lookup)) { 1108 symname = symbol_name(ef, rel->r_info); 1109 printf("link_elf_obj: symbol %s undefined\n", 1110 symname); 1111 return (ENOENT); 1112 } 1113 } 1114 } 1115 1116 /* Perform relocations with addend if there are any: */ 1117 for (i = 0; i < ef->nrelatab; i++) { 1118 rela = ef->relatab[i].rela; 1119 if (rela == NULL) { 1120 link_elf_error(ef->lf.filename, "lost a relatab!"); 1121 return (ENOEXEC); 1122 } 1123 relalim = rela + ef->relatab[i].nrela; 1124 base = findbase(ef, ef->relatab[i].sec); 1125 if (base == 0) { 1126 link_elf_error(ef->lf.filename, 1127 "lost base for relatab"); 1128 return (ENOEXEC); 1129 } 1130 for ( ; rela < relalim; rela++) { 1131 symidx = ELF_R_SYM(rela->r_info); 1132 if (symidx >= ef->ddbsymcnt) 1133 continue; 1134 sym = ef->ddbsymtab + symidx; 1135 /* Local relocs are already done */ 1136 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1137 continue; 1138 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1139 elf_obj_lookup)) { 1140 symname = symbol_name(ef, rela->r_info); 1141 printf("link_elf_obj: symbol %s undefined\n", 1142 symname); 1143 return (ENOENT); 1144 } 1145 } 1146 } 1147 1148 /* 1149 * Only clean SHN_FBSD_CACHED for successful return. If we 1150 * modified symbol table for the object but found an 1151 * unresolved symbol, there is no reason to roll back. 1152 */ 1153 elf_obj_cleanup_globals_cache(ef); 1154 1155 return (0); 1156 } 1157 1158 static int 1159 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1160 { 1161 elf_file_t ef = (elf_file_t) lf; 1162 const Elf_Sym *symp; 1163 const char *strp; 1164 int i; 1165 1166 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1167 strp = ef->ddbstrtab + symp->st_name; 1168 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1169 *sym = (c_linker_sym_t) symp; 1170 return 0; 1171 } 1172 } 1173 return ENOENT; 1174 } 1175 1176 static int 1177 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1178 linker_symval_t *symval) 1179 { 1180 elf_file_t ef = (elf_file_t) lf; 1181 const Elf_Sym *es = (const Elf_Sym*) sym; 1182 1183 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1184 symval->name = ef->ddbstrtab + es->st_name; 1185 symval->value = (caddr_t)es->st_value; 1186 symval->size = es->st_size; 1187 return 0; 1188 } 1189 return ENOENT; 1190 } 1191 1192 static int 1193 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1194 c_linker_sym_t *sym, long *diffp) 1195 { 1196 elf_file_t ef = (elf_file_t) lf; 1197 u_long off = (uintptr_t) (void *) value; 1198 u_long diff = off; 1199 u_long st_value; 1200 const Elf_Sym *es; 1201 const Elf_Sym *best = NULL; 1202 int i; 1203 1204 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1205 if (es->st_name == 0) 1206 continue; 1207 st_value = es->st_value; 1208 if (off >= st_value) { 1209 if (off - st_value < diff) { 1210 diff = off - st_value; 1211 best = es; 1212 if (diff == 0) 1213 break; 1214 } else if (off - st_value == diff) { 1215 best = es; 1216 } 1217 } 1218 } 1219 if (best == NULL) 1220 *diffp = off; 1221 else 1222 *diffp = diff; 1223 *sym = (c_linker_sym_t) best; 1224 1225 return 0; 1226 } 1227 1228 /* 1229 * Look up a linker set on an ELF system. 1230 */ 1231 static int 1232 link_elf_lookup_set(linker_file_t lf, const char *name, 1233 void ***startp, void ***stopp, int *countp) 1234 { 1235 elf_file_t ef = (elf_file_t)lf; 1236 void **start, **stop; 1237 int i, count; 1238 1239 /* Relative to section number */ 1240 for (i = 0; i < ef->nprogtab; i++) { 1241 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1242 strcmp(ef->progtab[i].name + 4, name) == 0) { 1243 start = (void **)ef->progtab[i].addr; 1244 stop = (void **)((char *)ef->progtab[i].addr + 1245 ef->progtab[i].size); 1246 count = stop - start; 1247 if (startp) 1248 *startp = start; 1249 if (stopp) 1250 *stopp = stop; 1251 if (countp) 1252 *countp = count; 1253 return (0); 1254 } 1255 } 1256 return (ESRCH); 1257 } 1258 1259 static int 1260 link_elf_each_function_name(linker_file_t file, 1261 int (*callback)(const char *, void *), void *opaque) 1262 { 1263 elf_file_t ef = (elf_file_t)file; 1264 const Elf_Sym *symp; 1265 int i, error; 1266 1267 /* Exhaustive search */ 1268 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1269 if (symp->st_value != 0 && 1270 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1271 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1272 if (error) 1273 return (error); 1274 } 1275 } 1276 return (0); 1277 } 1278 1279 static int 1280 link_elf_each_function_nameval(linker_file_t file, 1281 linker_function_nameval_callback_t callback, void *opaque) 1282 { 1283 linker_symval_t symval; 1284 elf_file_t ef = (elf_file_t)file; 1285 const Elf_Sym* symp; 1286 int i, error; 1287 1288 /* Exhaustive search */ 1289 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1290 if (symp->st_value != 0 && 1291 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1292 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1293 if (error) 1294 return (error); 1295 error = callback(file, i, &symval, opaque); 1296 if (error) 1297 return (error); 1298 } 1299 } 1300 return (0); 1301 } 1302 1303 static void 1304 elf_obj_cleanup_globals_cache(elf_file_t ef) 1305 { 1306 Elf_Sym *sym; 1307 Elf_Size i; 1308 1309 for (i = 0; i < ef->ddbsymcnt; i++) { 1310 sym = ef->ddbsymtab + i; 1311 if (sym->st_shndx == SHN_FBSD_CACHED) { 1312 sym->st_shndx = SHN_UNDEF; 1313 sym->st_value = 0; 1314 } 1315 } 1316 } 1317 1318 /* 1319 * Symbol lookup function that can be used when the symbol index is known (ie 1320 * in relocations). It uses the symbol index instead of doing a fully fledged 1321 * hash table based lookup when such is valid. For example for local symbols. 1322 * This is not only more efficient, it's also more correct. It's not always 1323 * the case that the symbol can be found through the hash table. 1324 */ 1325 static int 1326 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1327 { 1328 elf_file_t ef = (elf_file_t)lf; 1329 Elf_Sym *sym; 1330 const char *symbol; 1331 Elf_Addr res1; 1332 1333 /* Don't even try to lookup the symbol if the index is bogus. */ 1334 if (symidx >= ef->ddbsymcnt) { 1335 *res = 0; 1336 return (EINVAL); 1337 } 1338 1339 sym = ef->ddbsymtab + symidx; 1340 1341 /* Quick answer if there is a definition included. */ 1342 if (sym->st_shndx != SHN_UNDEF) { 1343 *res = sym->st_value; 1344 return (0); 1345 } 1346 1347 /* If we get here, then it is undefined and needs a lookup. */ 1348 switch (ELF_ST_BIND(sym->st_info)) { 1349 case STB_LOCAL: 1350 /* Local, but undefined? huh? */ 1351 *res = 0; 1352 return (EINVAL); 1353 1354 case STB_GLOBAL: 1355 case STB_WEAK: 1356 /* Relative to Data or Function name */ 1357 symbol = ef->ddbstrtab + sym->st_name; 1358 1359 /* Force a lookup failure if the symbol name is bogus. */ 1360 if (*symbol == 0) { 1361 *res = 0; 1362 return (EINVAL); 1363 } 1364 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1365 1366 /* 1367 * Cache global lookups during module relocation. The failure 1368 * case is particularly expensive for callers, who must scan 1369 * through the entire globals table doing strcmp(). Cache to 1370 * avoid doing such work repeatedly. 1371 * 1372 * After relocation is complete, undefined globals will be 1373 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1374 * above. 1375 */ 1376 if (res1 != 0) { 1377 sym->st_shndx = SHN_FBSD_CACHED; 1378 sym->st_value = res1; 1379 *res = res1; 1380 return (0); 1381 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1382 sym->st_value = 0; 1383 *res = 0; 1384 return (0); 1385 } 1386 return (EINVAL); 1387 1388 default: 1389 return (EINVAL); 1390 } 1391 } 1392 1393 static void 1394 link_elf_fix_link_set(elf_file_t ef) 1395 { 1396 static const char startn[] = "__start_"; 1397 static const char stopn[] = "__stop_"; 1398 Elf_Sym *sym; 1399 const char *sym_name, *linkset_name; 1400 Elf_Addr startp, stopp; 1401 Elf_Size symidx; 1402 int start, i; 1403 1404 startp = stopp = 0; 1405 for (symidx = 1 /* zero entry is special */; 1406 symidx < ef->ddbsymcnt; symidx++) { 1407 sym = ef->ddbsymtab + symidx; 1408 if (sym->st_shndx != SHN_UNDEF) 1409 continue; 1410 1411 sym_name = ef->ddbstrtab + sym->st_name; 1412 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1413 start = 1; 1414 linkset_name = sym_name + sizeof(startn) - 1; 1415 } 1416 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1417 start = 0; 1418 linkset_name = sym_name + sizeof(stopn) - 1; 1419 } 1420 else 1421 continue; 1422 1423 for (i = 0; i < ef->nprogtab; i++) { 1424 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1425 startp = (Elf_Addr)ef->progtab[i].addr; 1426 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1427 break; 1428 } 1429 } 1430 if (i == ef->nprogtab) 1431 continue; 1432 1433 sym->st_value = start ? startp : stopp; 1434 sym->st_shndx = i; 1435 } 1436 } 1437 1438 static int 1439 link_elf_reloc_local(linker_file_t lf) 1440 { 1441 elf_file_t ef = (elf_file_t)lf; 1442 const Elf_Rel *rellim; 1443 const Elf_Rel *rel; 1444 const Elf_Rela *relalim; 1445 const Elf_Rela *rela; 1446 const Elf_Sym *sym; 1447 Elf_Addr base; 1448 int i; 1449 Elf_Size symidx; 1450 1451 link_elf_fix_link_set(ef); 1452 1453 /* Perform relocations without addend if there are any: */ 1454 for (i = 0; i < ef->nreltab; i++) { 1455 rel = ef->reltab[i].rel; 1456 if (rel == NULL) { 1457 link_elf_error(ef->lf.filename, "lost a reltab"); 1458 return (ENOEXEC); 1459 } 1460 rellim = rel + ef->reltab[i].nrel; 1461 base = findbase(ef, ef->reltab[i].sec); 1462 if (base == 0) { 1463 link_elf_error(ef->lf.filename, "lost base for reltab"); 1464 return (ENOEXEC); 1465 } 1466 for ( ; rel < rellim; rel++) { 1467 symidx = ELF_R_SYM(rel->r_info); 1468 if (symidx >= ef->ddbsymcnt) 1469 continue; 1470 sym = ef->ddbsymtab + symidx; 1471 /* Only do local relocs */ 1472 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1473 continue; 1474 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1475 elf_obj_lookup); 1476 } 1477 } 1478 1479 /* Perform relocations with addend if there are any: */ 1480 for (i = 0; i < ef->nrelatab; i++) { 1481 rela = ef->relatab[i].rela; 1482 if (rela == NULL) { 1483 link_elf_error(ef->lf.filename, "lost a relatab!"); 1484 return (ENOEXEC); 1485 } 1486 relalim = rela + ef->relatab[i].nrela; 1487 base = findbase(ef, ef->relatab[i].sec); 1488 if (base == 0) { 1489 link_elf_error(ef->lf.filename, "lost base for reltab"); 1490 return (ENOEXEC); 1491 } 1492 for ( ; rela < relalim; rela++) { 1493 symidx = ELF_R_SYM(rela->r_info); 1494 if (symidx >= ef->ddbsymcnt) 1495 continue; 1496 sym = ef->ddbsymtab + symidx; 1497 /* Only do local relocs */ 1498 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1499 continue; 1500 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1501 elf_obj_lookup); 1502 } 1503 } 1504 return (0); 1505 } 1506 1507 static long 1508 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1509 { 1510 elf_file_t ef = (elf_file_t)lf; 1511 1512 *symtab = ef->ddbsymtab; 1513 1514 if (*symtab == NULL) 1515 return (0); 1516 1517 return (ef->ddbsymcnt); 1518 } 1519 1520 static long 1521 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1522 { 1523 elf_file_t ef = (elf_file_t)lf; 1524 1525 *strtab = ef->ddbstrtab; 1526 1527 if (*strtab == NULL) 1528 return (0); 1529 1530 return (ef->ddbstrcnt); 1531 } 1532