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_AMD64_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_AMD64_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_AMD64_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 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 505 flags = FREAD; 506 error = vn_open(&nd, &flags, 0, NULL); 507 if (error) 508 return error; 509 NDFREE(&nd, NDF_ONLY_PNBUF); 510 if (nd.ni_vp->v_type != VREG) { 511 error = ENOEXEC; 512 goto out; 513 } 514 #ifdef MAC 515 error = mac_kld_check_load(td->td_ucred, nd.ni_vp); 516 if (error) { 517 goto out; 518 } 519 #endif 520 521 /* Read the elf header from the file. */ 522 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 523 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0, 524 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 525 &resid, td); 526 if (error) 527 goto out; 528 if (resid != 0){ 529 error = ENOEXEC; 530 goto out; 531 } 532 533 if (!IS_ELF(*hdr)) { 534 error = ENOEXEC; 535 goto out; 536 } 537 538 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 539 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 540 link_elf_error(filename, "Unsupported file layout"); 541 error = ENOEXEC; 542 goto out; 543 } 544 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 545 || hdr->e_version != EV_CURRENT) { 546 link_elf_error(filename, "Unsupported file version"); 547 error = ENOEXEC; 548 goto out; 549 } 550 if (hdr->e_type != ET_REL) { 551 error = ENOSYS; 552 goto out; 553 } 554 if (hdr->e_machine != ELF_TARG_MACH) { 555 link_elf_error(filename, "Unsupported machine"); 556 error = ENOEXEC; 557 goto out; 558 } 559 560 lf = linker_make_file(filename, &link_elf_class); 561 if (!lf) { 562 error = ENOMEM; 563 goto out; 564 } 565 ef = (elf_file_t) lf; 566 ef->nprogtab = 0; 567 ef->e_shdr = 0; 568 ef->nreltab = 0; 569 ef->nrelatab = 0; 570 571 /* Allocate and read in the section header */ 572 nbytes = hdr->e_shnum * hdr->e_shentsize; 573 if (nbytes == 0 || hdr->e_shoff == 0 || 574 hdr->e_shentsize != sizeof(Elf_Shdr)) { 575 error = ENOEXEC; 576 goto out; 577 } 578 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 579 ef->e_shdr = shdr; 580 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff, 581 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); 582 if (error) 583 goto out; 584 if (resid) { 585 error = ENOEXEC; 586 goto out; 587 } 588 589 /* Scan the section header for information and table sizing. */ 590 nsym = 0; 591 symtabindex = -1; 592 symstrindex = -1; 593 for (i = 0; i < hdr->e_shnum; i++) { 594 if (shdr[i].sh_size == 0) 595 continue; 596 switch (shdr[i].sh_type) { 597 case SHT_PROGBITS: 598 case SHT_NOBITS: 599 #ifdef __amd64__ 600 case SHT_AMD64_UNWIND: 601 #endif 602 ef->nprogtab++; 603 break; 604 case SHT_SYMTAB: 605 nsym++; 606 symtabindex = i; 607 symstrindex = shdr[i].sh_link; 608 break; 609 case SHT_REL: 610 ef->nreltab++; 611 break; 612 case SHT_RELA: 613 ef->nrelatab++; 614 break; 615 case SHT_STRTAB: 616 break; 617 } 618 } 619 if (ef->nprogtab == 0) { 620 link_elf_error(filename, "file has no contents"); 621 error = ENOEXEC; 622 goto out; 623 } 624 if (nsym != 1) { 625 /* Only allow one symbol table for now */ 626 link_elf_error(filename, "file has no valid symbol table"); 627 error = ENOEXEC; 628 goto out; 629 } 630 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 631 shdr[symstrindex].sh_type != SHT_STRTAB) { 632 link_elf_error(filename, "file has invalid symbol strings"); 633 error = ENOEXEC; 634 goto out; 635 } 636 637 /* Allocate space for tracking the load chunks */ 638 if (ef->nprogtab != 0) 639 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 640 M_LINKER, M_WAITOK | M_ZERO); 641 if (ef->nreltab != 0) 642 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 643 M_LINKER, M_WAITOK | M_ZERO); 644 if (ef->nrelatab != 0) 645 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 646 M_LINKER, M_WAITOK | M_ZERO); 647 648 if (symtabindex == -1) { 649 link_elf_error(filename, "lost symbol table index"); 650 error = ENOEXEC; 651 goto out; 652 } 653 /* Allocate space for and load the symbol table */ 654 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 655 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 656 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab, 657 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 658 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 659 &resid, td); 660 if (error) 661 goto out; 662 if (resid != 0){ 663 error = EINVAL; 664 goto out; 665 } 666 667 if (symstrindex == -1) { 668 link_elf_error(filename, "lost symbol string index"); 669 error = ENOEXEC; 670 goto out; 671 } 672 /* Allocate space for and load the symbol strings */ 673 ef->ddbstrcnt = shdr[symstrindex].sh_size; 674 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 675 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab, 676 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 677 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 678 &resid, td); 679 if (error) 680 goto out; 681 if (resid != 0){ 682 error = EINVAL; 683 goto out; 684 } 685 686 /* Do we have a string table for the section names? */ 687 shstrindex = -1; 688 if (hdr->e_shstrndx != 0 && 689 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 690 shstrindex = hdr->e_shstrndx; 691 ef->shstrcnt = shdr[shstrindex].sh_size; 692 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 693 M_WAITOK); 694 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab, 695 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 696 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 697 &resid, td); 698 if (error) 699 goto out; 700 if (resid != 0){ 701 error = EINVAL; 702 goto out; 703 } 704 } 705 706 /* Size up code/data(progbits) and bss(nobits). */ 707 alignmask = 0; 708 for (i = 0; i < hdr->e_shnum; i++) { 709 if (shdr[i].sh_size == 0) 710 continue; 711 switch (shdr[i].sh_type) { 712 case SHT_PROGBITS: 713 case SHT_NOBITS: 714 #ifdef __amd64__ 715 case SHT_AMD64_UNWIND: 716 #endif 717 alignmask = shdr[i].sh_addralign - 1; 718 mapsize += alignmask; 719 mapsize &= ~alignmask; 720 mapsize += shdr[i].sh_size; 721 break; 722 } 723 } 724 725 /* 726 * We know how much space we need for the text/data/bss/etc. 727 * This stuff needs to be in a single chunk so that profiling etc 728 * can get the bounds and gdb can associate offsets with modules 729 */ 730 ef->object = vm_object_allocate(OBJT_DEFAULT, 731 round_page(mapsize) >> PAGE_SHIFT); 732 if (ef->object == NULL) { 733 error = ENOMEM; 734 goto out; 735 } 736 ef->address = (caddr_t) vm_map_min(kernel_map); 737 738 /* 739 * In order to satisfy amd64's architectural requirements on the 740 * location of code and data in the kernel's address space, request a 741 * mapping that is above the kernel. 742 */ 743 #ifdef __amd64__ 744 mapbase = KERNBASE; 745 #else 746 mapbase = VM_MIN_KERNEL_ADDRESS; 747 #endif 748 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 749 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 750 VM_PROT_ALL, 0); 751 if (error) { 752 vm_object_deallocate(ef->object); 753 ef->object = 0; 754 goto out; 755 } 756 757 /* Wire the pages */ 758 error = vm_map_wire(kernel_map, mapbase, 759 mapbase + round_page(mapsize), 760 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 761 if (error != KERN_SUCCESS) { 762 error = ENOMEM; 763 goto out; 764 } 765 766 /* Inform the kld system about the situation */ 767 lf->address = ef->address = (caddr_t)mapbase; 768 lf->size = mapsize; 769 770 /* 771 * Now load code/data(progbits), zero bss(nobits), allocate space for 772 * and load relocs 773 */ 774 pb = 0; 775 rl = 0; 776 ra = 0; 777 alignmask = 0; 778 for (i = 0; i < hdr->e_shnum; i++) { 779 if (shdr[i].sh_size == 0) 780 continue; 781 switch (shdr[i].sh_type) { 782 case SHT_PROGBITS: 783 case SHT_NOBITS: 784 #ifdef __amd64__ 785 case SHT_AMD64_UNWIND: 786 #endif 787 alignmask = shdr[i].sh_addralign - 1; 788 mapbase += alignmask; 789 mapbase &= ~alignmask; 790 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 791 ef->progtab[pb].name = 792 ef->shstrtab + shdr[i].sh_name; 793 if (!strcmp(ef->progtab[pb].name, ".ctors")) { 794 lf->ctors_addr = (caddr_t)mapbase; 795 lf->ctors_size = shdr[i].sh_size; 796 } 797 } else if (shdr[i].sh_type == SHT_PROGBITS) 798 ef->progtab[pb].name = "<<PROGBITS>>"; 799 #ifdef __amd64__ 800 else if (shdr[i].sh_type == SHT_AMD64_UNWIND) 801 ef->progtab[pb].name = "<<UNWIND>>"; 802 #endif 803 else 804 ef->progtab[pb].name = "<<NOBITS>>"; 805 if (ef->progtab[pb].name != NULL && 806 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 807 ef->progtab[pb].addr = 808 dpcpu_alloc(shdr[i].sh_size); 809 #ifdef VIMAGE 810 else if (ef->progtab[pb].name != NULL && 811 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 812 ef->progtab[pb].addr = 813 vnet_data_alloc(shdr[i].sh_size); 814 #endif 815 else 816 ef->progtab[pb].addr = 817 (void *)(uintptr_t)mapbase; 818 if (ef->progtab[pb].addr == NULL) { 819 error = ENOSPC; 820 goto out; 821 } 822 ef->progtab[pb].size = shdr[i].sh_size; 823 ef->progtab[pb].sec = i; 824 if (shdr[i].sh_type == SHT_PROGBITS 825 #ifdef __amd64__ 826 || shdr[i].sh_type == SHT_AMD64_UNWIND 827 #endif 828 ) { 829 error = vn_rdwr(UIO_READ, nd.ni_vp, 830 ef->progtab[pb].addr, 831 shdr[i].sh_size, shdr[i].sh_offset, 832 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 833 NOCRED, &resid, td); 834 if (error) 835 goto out; 836 if (resid != 0){ 837 error = EINVAL; 838 goto out; 839 } 840 /* Initialize the per-cpu or vnet area. */ 841 if (ef->progtab[pb].addr != (void *)mapbase && 842 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 843 dpcpu_copy(ef->progtab[pb].addr, 844 shdr[i].sh_size); 845 #ifdef VIMAGE 846 else if (ef->progtab[pb].addr != 847 (void *)mapbase && 848 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 849 vnet_data_copy(ef->progtab[pb].addr, 850 shdr[i].sh_size); 851 #endif 852 } else 853 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 854 855 /* Update all symbol values with the offset. */ 856 for (j = 0; j < ef->ddbsymcnt; j++) { 857 es = &ef->ddbsymtab[j]; 858 if (es->st_shndx != i) 859 continue; 860 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 861 } 862 mapbase += shdr[i].sh_size; 863 pb++; 864 break; 865 case SHT_REL: 866 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 867 M_WAITOK); 868 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 869 ef->reltab[rl].sec = shdr[i].sh_info; 870 error = vn_rdwr(UIO_READ, nd.ni_vp, 871 (void *)ef->reltab[rl].rel, 872 shdr[i].sh_size, shdr[i].sh_offset, 873 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 874 &resid, td); 875 if (error) 876 goto out; 877 if (resid != 0){ 878 error = EINVAL; 879 goto out; 880 } 881 rl++; 882 break; 883 case SHT_RELA: 884 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 885 M_WAITOK); 886 ef->relatab[ra].nrela = 887 shdr[i].sh_size / sizeof(Elf_Rela); 888 ef->relatab[ra].sec = shdr[i].sh_info; 889 error = vn_rdwr(UIO_READ, nd.ni_vp, 890 (void *)ef->relatab[ra].rela, 891 shdr[i].sh_size, shdr[i].sh_offset, 892 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 893 &resid, td); 894 if (error) 895 goto out; 896 if (resid != 0){ 897 error = EINVAL; 898 goto out; 899 } 900 ra++; 901 break; 902 } 903 } 904 if (pb != ef->nprogtab) { 905 link_elf_error(filename, "lost progbits"); 906 error = ENOEXEC; 907 goto out; 908 } 909 if (rl != ef->nreltab) { 910 link_elf_error(filename, "lost reltab"); 911 error = ENOEXEC; 912 goto out; 913 } 914 if (ra != ef->nrelatab) { 915 link_elf_error(filename, "lost relatab"); 916 error = ENOEXEC; 917 goto out; 918 } 919 if (mapbase != (vm_offset_t)ef->address + mapsize) { 920 printf( 921 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 922 filename != NULL ? filename : "<none>", 923 (u_long)mapbase, ef->address, (u_long)mapsize, 924 (u_long)(vm_offset_t)ef->address + mapsize); 925 error = ENOMEM; 926 goto out; 927 } 928 929 /* Local intra-module relocations */ 930 error = link_elf_reloc_local(lf); 931 if (error != 0) 932 goto out; 933 934 /* Pull in dependencies */ 935 VOP_UNLOCK(nd.ni_vp, 0); 936 error = linker_load_dependencies(lf); 937 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 938 if (error) 939 goto out; 940 941 /* External relocations */ 942 error = relocate_file(ef); 943 if (error) 944 goto out; 945 946 /* Notify MD code that a module is being loaded. */ 947 error = elf_cpu_load_file(lf); 948 if (error) 949 goto out; 950 951 /* Invoke .ctors */ 952 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 953 954 *result = lf; 955 956 out: 957 VOP_UNLOCK(nd.ni_vp, 0); 958 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 959 if (error && lf) 960 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 961 free(hdr, M_LINKER); 962 963 return error; 964 } 965 966 static void 967 link_elf_unload_file(linker_file_t file) 968 { 969 elf_file_t ef = (elf_file_t) file; 970 int i; 971 972 /* Notify MD code that a module is being unloaded. */ 973 elf_cpu_unload_file(file); 974 975 if (ef->progtab) { 976 for (i = 0; i < ef->nprogtab; i++) { 977 if (ef->progtab[i].size == 0) 978 continue; 979 if (ef->progtab[i].name == NULL) 980 continue; 981 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 982 dpcpu_free(ef->progtab[i].addr, 983 ef->progtab[i].size); 984 #ifdef VIMAGE 985 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 986 vnet_data_free(ef->progtab[i].addr, 987 ef->progtab[i].size); 988 #endif 989 } 990 } 991 if (ef->preloaded) { 992 free(ef->reltab, M_LINKER); 993 free(ef->relatab, M_LINKER); 994 free(ef->progtab, M_LINKER); 995 free(ef->ctftab, M_LINKER); 996 free(ef->ctfoff, M_LINKER); 997 free(ef->typoff, M_LINKER); 998 if (file->filename != NULL) 999 preload_delete_name(file->filename); 1000 /* XXX reclaim module memory? */ 1001 return; 1002 } 1003 1004 for (i = 0; i < ef->nreltab; i++) 1005 free(ef->reltab[i].rel, M_LINKER); 1006 for (i = 0; i < ef->nrelatab; i++) 1007 free(ef->relatab[i].rela, M_LINKER); 1008 free(ef->reltab, M_LINKER); 1009 free(ef->relatab, M_LINKER); 1010 free(ef->progtab, M_LINKER); 1011 1012 if (ef->object) { 1013 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1014 (vm_offset_t) ef->address + 1015 (ef->object->size << PAGE_SHIFT)); 1016 } 1017 free(ef->e_shdr, M_LINKER); 1018 free(ef->ddbsymtab, M_LINKER); 1019 free(ef->ddbstrtab, M_LINKER); 1020 free(ef->shstrtab, M_LINKER); 1021 free(ef->ctftab, M_LINKER); 1022 free(ef->ctfoff, M_LINKER); 1023 free(ef->typoff, M_LINKER); 1024 } 1025 1026 static const char * 1027 symbol_name(elf_file_t ef, Elf_Size r_info) 1028 { 1029 const Elf_Sym *ref; 1030 1031 if (ELF_R_SYM(r_info)) { 1032 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1033 return ef->ddbstrtab + ref->st_name; 1034 } else 1035 return NULL; 1036 } 1037 1038 static Elf_Addr 1039 findbase(elf_file_t ef, int sec) 1040 { 1041 int i; 1042 Elf_Addr base = 0; 1043 1044 for (i = 0; i < ef->nprogtab; i++) { 1045 if (sec == ef->progtab[i].sec) { 1046 base = (Elf_Addr)ef->progtab[i].addr; 1047 break; 1048 } 1049 } 1050 return base; 1051 } 1052 1053 static int 1054 relocate_file(elf_file_t ef) 1055 { 1056 const Elf_Rel *rellim; 1057 const Elf_Rel *rel; 1058 const Elf_Rela *relalim; 1059 const Elf_Rela *rela; 1060 const char *symname; 1061 const Elf_Sym *sym; 1062 int i; 1063 Elf_Size symidx; 1064 Elf_Addr base; 1065 1066 1067 /* Perform relocations without addend if there are any: */ 1068 for (i = 0; i < ef->nreltab; i++) { 1069 rel = ef->reltab[i].rel; 1070 if (rel == NULL) { 1071 link_elf_error(ef->lf.filename, "lost a reltab!"); 1072 return (ENOEXEC); 1073 } 1074 rellim = rel + ef->reltab[i].nrel; 1075 base = findbase(ef, ef->reltab[i].sec); 1076 if (base == 0) { 1077 link_elf_error(ef->lf.filename, "lost base for reltab"); 1078 return (ENOEXEC); 1079 } 1080 for ( ; rel < rellim; rel++) { 1081 symidx = ELF_R_SYM(rel->r_info); 1082 if (symidx >= ef->ddbsymcnt) 1083 continue; 1084 sym = ef->ddbsymtab + symidx; 1085 /* Local relocs are already done */ 1086 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1087 continue; 1088 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1089 elf_obj_lookup)) { 1090 symname = symbol_name(ef, rel->r_info); 1091 printf("link_elf_obj: symbol %s undefined\n", 1092 symname); 1093 return (ENOENT); 1094 } 1095 } 1096 } 1097 1098 /* Perform relocations with addend if there are any: */ 1099 for (i = 0; i < ef->nrelatab; i++) { 1100 rela = ef->relatab[i].rela; 1101 if (rela == NULL) { 1102 link_elf_error(ef->lf.filename, "lost a relatab!"); 1103 return (ENOEXEC); 1104 } 1105 relalim = rela + ef->relatab[i].nrela; 1106 base = findbase(ef, ef->relatab[i].sec); 1107 if (base == 0) { 1108 link_elf_error(ef->lf.filename, 1109 "lost base for relatab"); 1110 return (ENOEXEC); 1111 } 1112 for ( ; rela < relalim; rela++) { 1113 symidx = ELF_R_SYM(rela->r_info); 1114 if (symidx >= ef->ddbsymcnt) 1115 continue; 1116 sym = ef->ddbsymtab + symidx; 1117 /* Local relocs are already done */ 1118 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1119 continue; 1120 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1121 elf_obj_lookup)) { 1122 symname = symbol_name(ef, rela->r_info); 1123 printf("link_elf_obj: symbol %s undefined\n", 1124 symname); 1125 return (ENOENT); 1126 } 1127 } 1128 } 1129 1130 /* 1131 * Only clean SHN_FBSD_CACHED for successfull return. If we 1132 * modified symbol table for the object but found an 1133 * unresolved symbol, there is no reason to roll back. 1134 */ 1135 elf_obj_cleanup_globals_cache(ef); 1136 1137 return (0); 1138 } 1139 1140 static int 1141 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1142 { 1143 elf_file_t ef = (elf_file_t) lf; 1144 const Elf_Sym *symp; 1145 const char *strp; 1146 int i; 1147 1148 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1149 strp = ef->ddbstrtab + symp->st_name; 1150 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1151 *sym = (c_linker_sym_t) symp; 1152 return 0; 1153 } 1154 } 1155 return ENOENT; 1156 } 1157 1158 static int 1159 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1160 linker_symval_t *symval) 1161 { 1162 elf_file_t ef = (elf_file_t) lf; 1163 const Elf_Sym *es = (const Elf_Sym*) sym; 1164 1165 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1166 symval->name = ef->ddbstrtab + es->st_name; 1167 symval->value = (caddr_t)es->st_value; 1168 symval->size = es->st_size; 1169 return 0; 1170 } 1171 return ENOENT; 1172 } 1173 1174 static int 1175 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1176 c_linker_sym_t *sym, long *diffp) 1177 { 1178 elf_file_t ef = (elf_file_t) lf; 1179 u_long off = (uintptr_t) (void *) value; 1180 u_long diff = off; 1181 u_long st_value; 1182 const Elf_Sym *es; 1183 const Elf_Sym *best = 0; 1184 int i; 1185 1186 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1187 if (es->st_name == 0) 1188 continue; 1189 st_value = es->st_value; 1190 if (off >= st_value) { 1191 if (off - st_value < diff) { 1192 diff = off - st_value; 1193 best = es; 1194 if (diff == 0) 1195 break; 1196 } else if (off - st_value == diff) { 1197 best = es; 1198 } 1199 } 1200 } 1201 if (best == 0) 1202 *diffp = off; 1203 else 1204 *diffp = diff; 1205 *sym = (c_linker_sym_t) best; 1206 1207 return 0; 1208 } 1209 1210 /* 1211 * Look up a linker set on an ELF system. 1212 */ 1213 static int 1214 link_elf_lookup_set(linker_file_t lf, const char *name, 1215 void ***startp, void ***stopp, int *countp) 1216 { 1217 elf_file_t ef = (elf_file_t)lf; 1218 void **start, **stop; 1219 int i, count; 1220 1221 /* Relative to section number */ 1222 for (i = 0; i < ef->nprogtab; i++) { 1223 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1224 strcmp(ef->progtab[i].name + 4, name) == 0) { 1225 start = (void **)ef->progtab[i].addr; 1226 stop = (void **)((char *)ef->progtab[i].addr + 1227 ef->progtab[i].size); 1228 count = stop - start; 1229 if (startp) 1230 *startp = start; 1231 if (stopp) 1232 *stopp = stop; 1233 if (countp) 1234 *countp = count; 1235 return (0); 1236 } 1237 } 1238 return (ESRCH); 1239 } 1240 1241 static int 1242 link_elf_each_function_name(linker_file_t file, 1243 int (*callback)(const char *, void *), void *opaque) 1244 { 1245 elf_file_t ef = (elf_file_t)file; 1246 const Elf_Sym *symp; 1247 int i, error; 1248 1249 /* Exhaustive search */ 1250 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1251 if (symp->st_value != 0 && 1252 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1253 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1254 if (error) 1255 return (error); 1256 } 1257 } 1258 return (0); 1259 } 1260 1261 static int 1262 link_elf_each_function_nameval(linker_file_t file, 1263 linker_function_nameval_callback_t callback, void *opaque) 1264 { 1265 linker_symval_t symval; 1266 elf_file_t ef = (elf_file_t)file; 1267 const Elf_Sym* symp; 1268 int i, error; 1269 1270 /* Exhaustive search */ 1271 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1272 if (symp->st_value != 0 && 1273 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1274 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1275 if (error) 1276 return (error); 1277 error = callback(file, i, &symval, opaque); 1278 if (error) 1279 return (error); 1280 } 1281 } 1282 return (0); 1283 } 1284 1285 static void 1286 elf_obj_cleanup_globals_cache(elf_file_t ef) 1287 { 1288 Elf_Sym *sym; 1289 Elf_Size i; 1290 1291 for (i = 0; i < ef->ddbsymcnt; i++) { 1292 sym = ef->ddbsymtab + i; 1293 if (sym->st_shndx == SHN_FBSD_CACHED) { 1294 sym->st_shndx = SHN_UNDEF; 1295 sym->st_value = 0; 1296 } 1297 } 1298 } 1299 1300 /* 1301 * Symbol lookup function that can be used when the symbol index is known (ie 1302 * in relocations). It uses the symbol index instead of doing a fully fledged 1303 * hash table based lookup when such is valid. For example for local symbols. 1304 * This is not only more efficient, it's also more correct. It's not always 1305 * the case that the symbol can be found through the hash table. 1306 */ 1307 static int 1308 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1309 { 1310 elf_file_t ef = (elf_file_t)lf; 1311 Elf_Sym *sym; 1312 const char *symbol; 1313 Elf_Addr res1; 1314 1315 /* Don't even try to lookup the symbol if the index is bogus. */ 1316 if (symidx >= ef->ddbsymcnt) { 1317 *res = 0; 1318 return (EINVAL); 1319 } 1320 1321 sym = ef->ddbsymtab + symidx; 1322 1323 /* Quick answer if there is a definition included. */ 1324 if (sym->st_shndx != SHN_UNDEF) { 1325 *res = sym->st_value; 1326 return (0); 1327 } 1328 1329 /* If we get here, then it is undefined and needs a lookup. */ 1330 switch (ELF_ST_BIND(sym->st_info)) { 1331 case STB_LOCAL: 1332 /* Local, but undefined? huh? */ 1333 *res = 0; 1334 return (EINVAL); 1335 1336 case STB_GLOBAL: 1337 case STB_WEAK: 1338 /* Relative to Data or Function name */ 1339 symbol = ef->ddbstrtab + sym->st_name; 1340 1341 /* Force a lookup failure if the symbol name is bogus. */ 1342 if (*symbol == 0) { 1343 *res = 0; 1344 return (EINVAL); 1345 } 1346 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1347 1348 /* 1349 * Cache global lookups during module relocation. The failure 1350 * case is particularly expensive for callers, who must scan 1351 * through the entire globals table doing strcmp(). Cache to 1352 * avoid doing such work repeatedly. 1353 * 1354 * After relocation is complete, undefined globals will be 1355 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1356 * above. 1357 */ 1358 if (res1 != 0) { 1359 sym->st_shndx = SHN_FBSD_CACHED; 1360 sym->st_value = res1; 1361 *res = res1; 1362 return (0); 1363 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1364 sym->st_value = 0; 1365 *res = 0; 1366 return (0); 1367 } 1368 return (EINVAL); 1369 1370 default: 1371 return (EINVAL); 1372 } 1373 } 1374 1375 static void 1376 link_elf_fix_link_set(elf_file_t ef) 1377 { 1378 static const char startn[] = "__start_"; 1379 static const char stopn[] = "__stop_"; 1380 Elf_Sym *sym; 1381 const char *sym_name, *linkset_name; 1382 Elf_Addr startp, stopp; 1383 Elf_Size symidx; 1384 int start, i; 1385 1386 startp = stopp = 0; 1387 for (symidx = 1 /* zero entry is special */; 1388 symidx < ef->ddbsymcnt; symidx++) { 1389 sym = ef->ddbsymtab + symidx; 1390 if (sym->st_shndx != SHN_UNDEF) 1391 continue; 1392 1393 sym_name = ef->ddbstrtab + sym->st_name; 1394 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1395 start = 1; 1396 linkset_name = sym_name + sizeof(startn) - 1; 1397 } 1398 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1399 start = 0; 1400 linkset_name = sym_name + sizeof(stopn) - 1; 1401 } 1402 else 1403 continue; 1404 1405 for (i = 0; i < ef->nprogtab; i++) { 1406 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1407 startp = (Elf_Addr)ef->progtab[i].addr; 1408 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1409 break; 1410 } 1411 } 1412 if (i == ef->nprogtab) 1413 continue; 1414 1415 sym->st_value = start ? startp : stopp; 1416 sym->st_shndx = i; 1417 } 1418 } 1419 1420 static int 1421 link_elf_reloc_local(linker_file_t lf) 1422 { 1423 elf_file_t ef = (elf_file_t)lf; 1424 const Elf_Rel *rellim; 1425 const Elf_Rel *rel; 1426 const Elf_Rela *relalim; 1427 const Elf_Rela *rela; 1428 const Elf_Sym *sym; 1429 Elf_Addr base; 1430 int i; 1431 Elf_Size symidx; 1432 1433 link_elf_fix_link_set(ef); 1434 1435 /* Perform relocations without addend if there are any: */ 1436 for (i = 0; i < ef->nreltab; i++) { 1437 rel = ef->reltab[i].rel; 1438 if (rel == NULL) { 1439 link_elf_error(ef->lf.filename, "lost a reltab"); 1440 return (ENOEXEC); 1441 } 1442 rellim = rel + ef->reltab[i].nrel; 1443 base = findbase(ef, ef->reltab[i].sec); 1444 if (base == 0) { 1445 link_elf_error(ef->lf.filename, "lost base for reltab"); 1446 return (ENOEXEC); 1447 } 1448 for ( ; rel < rellim; rel++) { 1449 symidx = ELF_R_SYM(rel->r_info); 1450 if (symidx >= ef->ddbsymcnt) 1451 continue; 1452 sym = ef->ddbsymtab + symidx; 1453 /* Only do local relocs */ 1454 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1455 continue; 1456 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1457 elf_obj_lookup); 1458 } 1459 } 1460 1461 /* Perform relocations with addend if there are any: */ 1462 for (i = 0; i < ef->nrelatab; i++) { 1463 rela = ef->relatab[i].rela; 1464 if (rela == NULL) { 1465 link_elf_error(ef->lf.filename, "lost a relatab!"); 1466 return (ENOEXEC); 1467 } 1468 relalim = rela + ef->relatab[i].nrela; 1469 base = findbase(ef, ef->relatab[i].sec); 1470 if (base == 0) { 1471 link_elf_error(ef->lf.filename, "lost base for reltab"); 1472 return (ENOEXEC); 1473 } 1474 for ( ; rela < relalim; rela++) { 1475 symidx = ELF_R_SYM(rela->r_info); 1476 if (symidx >= ef->ddbsymcnt) 1477 continue; 1478 sym = ef->ddbsymtab + symidx; 1479 /* Only do local relocs */ 1480 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1481 continue; 1482 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1483 elf_obj_lookup); 1484 } 1485 } 1486 return (0); 1487 } 1488 1489 static long 1490 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1491 { 1492 elf_file_t ef = (elf_file_t)lf; 1493 1494 *symtab = ef->ddbsymtab; 1495 1496 if (*symtab == NULL) 1497 return (0); 1498 1499 return (ef->ddbsymcnt); 1500 } 1501 1502 static long 1503 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1504 { 1505 elf_file_t ef = (elf_file_t)lf; 1506 1507 *strtab = ef->ddbstrtab; 1508 1509 if (*strtab == NULL) 1510 return (0); 1511 1512 return (ef->ddbstrcnt); 1513 } 1514