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 <contrib/zlib/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, bool); 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, NULL); 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 /* 276 * Ignore relocation tables for sections not 277 * loaded by the loader. 278 */ 279 if (shdr[shdr[i].sh_info].sh_addr == 0) 280 break; 281 ef->nreltab++; 282 break; 283 case SHT_RELA: 284 if (shdr[shdr[i].sh_info].sh_addr == 0) 285 break; 286 ef->nrelatab++; 287 break; 288 } 289 } 290 291 shstrindex = hdr->e_shstrndx; 292 if (ef->nprogtab == 0 || symstrindex < 0 || 293 symstrindex >= hdr->e_shnum || 294 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 295 shstrindex >= hdr->e_shnum || 296 shdr[shstrindex].sh_type != SHT_STRTAB) { 297 printf("%s: bad/missing section headers\n", filename); 298 error = ENOEXEC; 299 goto out; 300 } 301 302 /* Allocate space for tracking the load chunks */ 303 if (ef->nprogtab != 0) 304 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 305 M_LINKER, M_WAITOK | M_ZERO); 306 if (ef->nreltab != 0) 307 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 308 M_LINKER, M_WAITOK | M_ZERO); 309 if (ef->nrelatab != 0) 310 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 311 M_LINKER, M_WAITOK | M_ZERO); 312 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 313 (ef->nreltab != 0 && ef->reltab == NULL) || 314 (ef->nrelatab != 0 && ef->relatab == NULL)) { 315 error = ENOMEM; 316 goto out; 317 } 318 319 /* XXX, relocate the sh_addr fields saved by the loader. */ 320 off = 0; 321 for (i = 0; i < hdr->e_shnum; i++) { 322 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 323 off = shdr[i].sh_addr; 324 } 325 for (i = 0; i < hdr->e_shnum; i++) { 326 if (shdr[i].sh_addr != 0) 327 shdr[i].sh_addr = shdr[i].sh_addr - off + 328 (Elf_Addr)ef->address; 329 } 330 331 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 332 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 333 ef->ddbstrcnt = shdr[symstrindex].sh_size; 334 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 335 ef->shstrcnt = shdr[shstrindex].sh_size; 336 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 337 338 /* Now fill out progtab and the relocation tables. */ 339 pb = 0; 340 rl = 0; 341 ra = 0; 342 for (i = 0; i < hdr->e_shnum; i++) { 343 switch (shdr[i].sh_type) { 344 case SHT_PROGBITS: 345 case SHT_NOBITS: 346 #ifdef __amd64__ 347 case SHT_X86_64_UNWIND: 348 #endif 349 if (shdr[i].sh_addr == 0) 350 break; 351 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 352 if (shdr[i].sh_type == SHT_PROGBITS) 353 ef->progtab[pb].name = "<<PROGBITS>>"; 354 #ifdef __amd64__ 355 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 356 ef->progtab[pb].name = "<<UNWIND>>"; 357 #endif 358 else 359 ef->progtab[pb].name = "<<NOBITS>>"; 360 ef->progtab[pb].size = shdr[i].sh_size; 361 ef->progtab[pb].sec = i; 362 if (ef->shstrtab && shdr[i].sh_name != 0) 363 ef->progtab[pb].name = 364 ef->shstrtab + shdr[i].sh_name; 365 if (ef->progtab[pb].name != NULL && 366 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 367 void *dpcpu; 368 369 dpcpu = dpcpu_alloc(shdr[i].sh_size); 370 if (dpcpu == NULL) { 371 printf("%s: pcpu module space is out " 372 "of space; cannot allocate %#jx " 373 "for %s\n", __func__, 374 (uintmax_t)shdr[i].sh_size, 375 filename); 376 error = ENOSPC; 377 goto out; 378 } 379 memcpy(dpcpu, ef->progtab[pb].addr, 380 ef->progtab[pb].size); 381 dpcpu_copy(dpcpu, shdr[i].sh_size); 382 ef->progtab[pb].addr = dpcpu; 383 #ifdef VIMAGE 384 } else if (ef->progtab[pb].name != NULL && 385 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 386 void *vnet_data; 387 388 vnet_data = vnet_data_alloc(shdr[i].sh_size); 389 if (vnet_data == NULL) { 390 printf("%s: vnet module space is out " 391 "of space; cannot allocate %#jx " 392 "for %s\n", __func__, 393 (uintmax_t)shdr[i].sh_size, 394 filename); 395 error = ENOSPC; 396 goto out; 397 } 398 memcpy(vnet_data, ef->progtab[pb].addr, 399 ef->progtab[pb].size); 400 vnet_data_copy(vnet_data, shdr[i].sh_size); 401 ef->progtab[pb].addr = vnet_data; 402 #endif 403 } else if (ef->progtab[pb].name != NULL && 404 !strcmp(ef->progtab[pb].name, ".ctors")) { 405 lf->ctors_addr = ef->progtab[pb].addr; 406 lf->ctors_size = shdr[i].sh_size; 407 } 408 409 /* Update all symbol values with the offset. */ 410 for (j = 0; j < ef->ddbsymcnt; j++) { 411 es = &ef->ddbsymtab[j]; 412 if (es->st_shndx != i) 413 continue; 414 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 415 } 416 pb++; 417 break; 418 case SHT_REL: 419 if (shdr[shdr[i].sh_info].sh_addr == 0) 420 break; 421 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 422 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 423 ef->reltab[rl].sec = shdr[i].sh_info; 424 rl++; 425 break; 426 case SHT_RELA: 427 if (shdr[shdr[i].sh_info].sh_addr == 0) 428 break; 429 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 430 ef->relatab[ra].nrela = 431 shdr[i].sh_size / sizeof(Elf_Rela); 432 ef->relatab[ra].sec = shdr[i].sh_info; 433 ra++; 434 break; 435 } 436 } 437 if (pb != ef->nprogtab) { 438 printf("%s: lost progbits\n", filename); 439 error = ENOEXEC; 440 goto out; 441 } 442 if (rl != ef->nreltab) { 443 printf("%s: lost reltab\n", filename); 444 error = ENOEXEC; 445 goto out; 446 } 447 if (ra != ef->nrelatab) { 448 printf("%s: lost relatab\n", filename); 449 error = ENOEXEC; 450 goto out; 451 } 452 453 /* Local intra-module relocations */ 454 error = link_elf_reloc_local(lf, false); 455 if (error != 0) 456 goto out; 457 *result = lf; 458 return (0); 459 460 out: 461 /* preload not done this way */ 462 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 463 return (error); 464 } 465 466 static void 467 link_elf_invoke_ctors(caddr_t addr, size_t size) 468 { 469 void (**ctor)(void); 470 size_t i, cnt; 471 472 if (addr == NULL || size == 0) 473 return; 474 cnt = size / sizeof(*ctor); 475 ctor = (void *)addr; 476 for (i = 0; i < cnt; i++) { 477 if (ctor[i] != NULL) 478 (*ctor[i])(); 479 } 480 } 481 482 static int 483 link_elf_link_preload_finish(linker_file_t lf) 484 { 485 elf_file_t ef; 486 int error; 487 488 ef = (elf_file_t)lf; 489 error = relocate_file(ef); 490 if (error) 491 return (error); 492 493 /* Notify MD code that a module is being loaded. */ 494 error = elf_cpu_load_file(lf); 495 if (error) 496 return (error); 497 498 #if defined(__i386__) || defined(__amd64__) 499 /* Now ifuncs. */ 500 error = link_elf_reloc_local(lf, true); 501 if (error != 0) 502 return (error); 503 #endif 504 505 /* Invoke .ctors */ 506 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 507 return (0); 508 } 509 510 static int 511 link_elf_load_file(linker_class_t cls, const char *filename, 512 linker_file_t *result) 513 { 514 struct nameidata *nd; 515 struct thread *td = curthread; /* XXX */ 516 Elf_Ehdr *hdr; 517 Elf_Shdr *shdr; 518 Elf_Sym *es; 519 int nbytes, i, j; 520 vm_offset_t mapbase; 521 size_t mapsize; 522 int error = 0; 523 ssize_t resid; 524 int flags; 525 elf_file_t ef; 526 linker_file_t lf; 527 int symtabindex; 528 int symstrindex; 529 int shstrindex; 530 int nsym; 531 int pb, rl, ra; 532 int alignmask; 533 534 shdr = NULL; 535 lf = NULL; 536 mapsize = 0; 537 hdr = NULL; 538 539 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 540 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 541 flags = FREAD; 542 error = vn_open(nd, &flags, 0, NULL); 543 if (error) { 544 free(nd, M_TEMP); 545 return error; 546 } 547 NDFREE(nd, NDF_ONLY_PNBUF); 548 if (nd->ni_vp->v_type != VREG) { 549 error = ENOEXEC; 550 goto out; 551 } 552 #ifdef MAC 553 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 554 if (error) { 555 goto out; 556 } 557 #endif 558 559 /* Read the elf header from the file. */ 560 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 561 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 562 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 563 &resid, td); 564 if (error) 565 goto out; 566 if (resid != 0){ 567 error = ENOEXEC; 568 goto out; 569 } 570 571 if (!IS_ELF(*hdr)) { 572 error = ENOEXEC; 573 goto out; 574 } 575 576 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 577 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 578 link_elf_error(filename, "Unsupported file layout"); 579 error = ENOEXEC; 580 goto out; 581 } 582 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 583 || hdr->e_version != EV_CURRENT) { 584 link_elf_error(filename, "Unsupported file version"); 585 error = ENOEXEC; 586 goto out; 587 } 588 if (hdr->e_type != ET_REL) { 589 error = ENOSYS; 590 goto out; 591 } 592 if (hdr->e_machine != ELF_TARG_MACH) { 593 link_elf_error(filename, "Unsupported machine"); 594 error = ENOEXEC; 595 goto out; 596 } 597 598 lf = linker_make_file(filename, &link_elf_class); 599 if (!lf) { 600 error = ENOMEM; 601 goto out; 602 } 603 ef = (elf_file_t) lf; 604 ef->nprogtab = 0; 605 ef->e_shdr = 0; 606 ef->nreltab = 0; 607 ef->nrelatab = 0; 608 609 /* Allocate and read in the section header */ 610 nbytes = hdr->e_shnum * hdr->e_shentsize; 611 if (nbytes == 0 || hdr->e_shoff == 0 || 612 hdr->e_shentsize != sizeof(Elf_Shdr)) { 613 error = ENOEXEC; 614 goto out; 615 } 616 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 617 ef->e_shdr = shdr; 618 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 619 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 620 NOCRED, &resid, td); 621 if (error) 622 goto out; 623 if (resid) { 624 error = ENOEXEC; 625 goto out; 626 } 627 628 /* Scan the section header for information and table sizing. */ 629 nsym = 0; 630 symtabindex = -1; 631 symstrindex = -1; 632 for (i = 0; i < hdr->e_shnum; i++) { 633 if (shdr[i].sh_size == 0) 634 continue; 635 switch (shdr[i].sh_type) { 636 case SHT_PROGBITS: 637 case SHT_NOBITS: 638 #ifdef __amd64__ 639 case SHT_X86_64_UNWIND: 640 #endif 641 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 642 break; 643 ef->nprogtab++; 644 break; 645 case SHT_SYMTAB: 646 nsym++; 647 symtabindex = i; 648 symstrindex = shdr[i].sh_link; 649 break; 650 case SHT_REL: 651 /* 652 * Ignore relocation tables for unallocated 653 * sections. 654 */ 655 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 656 break; 657 ef->nreltab++; 658 break; 659 case SHT_RELA: 660 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 661 break; 662 ef->nrelatab++; 663 break; 664 case SHT_STRTAB: 665 break; 666 } 667 } 668 if (ef->nprogtab == 0) { 669 link_elf_error(filename, "file has no contents"); 670 error = ENOEXEC; 671 goto out; 672 } 673 if (nsym != 1) { 674 /* Only allow one symbol table for now */ 675 link_elf_error(filename, 676 "file must have exactly one symbol table"); 677 error = ENOEXEC; 678 goto out; 679 } 680 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 681 shdr[symstrindex].sh_type != SHT_STRTAB) { 682 link_elf_error(filename, "file has invalid symbol strings"); 683 error = ENOEXEC; 684 goto out; 685 } 686 687 /* Allocate space for tracking the load chunks */ 688 if (ef->nprogtab != 0) 689 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 690 M_LINKER, M_WAITOK | M_ZERO); 691 if (ef->nreltab != 0) 692 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 693 M_LINKER, M_WAITOK | M_ZERO); 694 if (ef->nrelatab != 0) 695 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 696 M_LINKER, M_WAITOK | M_ZERO); 697 698 if (symtabindex == -1) { 699 link_elf_error(filename, "lost symbol table index"); 700 error = ENOEXEC; 701 goto out; 702 } 703 /* Allocate space for and load the symbol table */ 704 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 705 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 706 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 707 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 708 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 709 &resid, td); 710 if (error) 711 goto out; 712 if (resid != 0){ 713 error = EINVAL; 714 goto out; 715 } 716 717 /* Allocate space for and load the symbol strings */ 718 ef->ddbstrcnt = shdr[symstrindex].sh_size; 719 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 720 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 721 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 722 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 723 &resid, td); 724 if (error) 725 goto out; 726 if (resid != 0){ 727 error = EINVAL; 728 goto out; 729 } 730 731 /* Do we have a string table for the section names? */ 732 shstrindex = -1; 733 if (hdr->e_shstrndx != 0 && 734 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 735 shstrindex = hdr->e_shstrndx; 736 ef->shstrcnt = shdr[shstrindex].sh_size; 737 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 738 M_WAITOK); 739 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 740 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 741 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 742 &resid, td); 743 if (error) 744 goto out; 745 if (resid != 0){ 746 error = EINVAL; 747 goto out; 748 } 749 } 750 751 /* Size up code/data(progbits) and bss(nobits). */ 752 alignmask = 0; 753 for (i = 0; i < hdr->e_shnum; i++) { 754 if (shdr[i].sh_size == 0) 755 continue; 756 switch (shdr[i].sh_type) { 757 case SHT_PROGBITS: 758 case SHT_NOBITS: 759 #ifdef __amd64__ 760 case SHT_X86_64_UNWIND: 761 #endif 762 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 763 break; 764 alignmask = shdr[i].sh_addralign - 1; 765 mapsize += alignmask; 766 mapsize &= ~alignmask; 767 mapsize += shdr[i].sh_size; 768 break; 769 } 770 } 771 772 /* 773 * We know how much space we need for the text/data/bss/etc. 774 * This stuff needs to be in a single chunk so that profiling etc 775 * can get the bounds and gdb can associate offsets with modules 776 */ 777 ef->object = vm_object_allocate(OBJT_DEFAULT, 778 round_page(mapsize) >> PAGE_SHIFT); 779 if (ef->object == NULL) { 780 error = ENOMEM; 781 goto out; 782 } 783 ef->address = (caddr_t) vm_map_min(kernel_map); 784 785 /* 786 * In order to satisfy amd64's architectural requirements on the 787 * location of code and data in the kernel's address space, request a 788 * mapping that is above the kernel. 789 */ 790 #ifdef __amd64__ 791 mapbase = KERNBASE; 792 #else 793 mapbase = VM_MIN_KERNEL_ADDRESS; 794 #endif 795 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 796 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 797 VM_PROT_ALL, 0); 798 if (error) { 799 vm_object_deallocate(ef->object); 800 ef->object = 0; 801 goto out; 802 } 803 804 /* Wire the pages */ 805 error = vm_map_wire(kernel_map, mapbase, 806 mapbase + round_page(mapsize), 807 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 808 if (error != KERN_SUCCESS) { 809 error = ENOMEM; 810 goto out; 811 } 812 813 /* Inform the kld system about the situation */ 814 lf->address = ef->address = (caddr_t)mapbase; 815 lf->size = mapsize; 816 817 /* 818 * Now load code/data(progbits), zero bss(nobits), allocate space for 819 * and load relocs 820 */ 821 pb = 0; 822 rl = 0; 823 ra = 0; 824 alignmask = 0; 825 for (i = 0; i < hdr->e_shnum; i++) { 826 if (shdr[i].sh_size == 0) 827 continue; 828 switch (shdr[i].sh_type) { 829 case SHT_PROGBITS: 830 case SHT_NOBITS: 831 #ifdef __amd64__ 832 case SHT_X86_64_UNWIND: 833 #endif 834 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 835 break; 836 alignmask = shdr[i].sh_addralign - 1; 837 mapbase += alignmask; 838 mapbase &= ~alignmask; 839 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 840 ef->progtab[pb].name = 841 ef->shstrtab + shdr[i].sh_name; 842 if (!strcmp(ef->progtab[pb].name, ".ctors")) { 843 lf->ctors_addr = (caddr_t)mapbase; 844 lf->ctors_size = shdr[i].sh_size; 845 } 846 } else if (shdr[i].sh_type == SHT_PROGBITS) 847 ef->progtab[pb].name = "<<PROGBITS>>"; 848 #ifdef __amd64__ 849 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 850 ef->progtab[pb].name = "<<UNWIND>>"; 851 #endif 852 else 853 ef->progtab[pb].name = "<<NOBITS>>"; 854 if (ef->progtab[pb].name != NULL && 855 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 856 ef->progtab[pb].addr = 857 dpcpu_alloc(shdr[i].sh_size); 858 if (ef->progtab[pb].addr == NULL) { 859 printf("%s: pcpu module space is out " 860 "of space; cannot allocate %#jx " 861 "for %s\n", __func__, 862 (uintmax_t)shdr[i].sh_size, 863 filename); 864 } 865 } 866 #ifdef VIMAGE 867 else if (ef->progtab[pb].name != NULL && 868 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 869 ef->progtab[pb].addr = 870 vnet_data_alloc(shdr[i].sh_size); 871 if (ef->progtab[pb].addr == NULL) { 872 printf("%s: vnet module space is out " 873 "of space; cannot allocate %#jx " 874 "for %s\n", __func__, 875 (uintmax_t)shdr[i].sh_size, 876 filename); 877 } 878 } 879 #endif 880 else 881 ef->progtab[pb].addr = 882 (void *)(uintptr_t)mapbase; 883 if (ef->progtab[pb].addr == NULL) { 884 error = ENOSPC; 885 goto out; 886 } 887 ef->progtab[pb].size = shdr[i].sh_size; 888 ef->progtab[pb].sec = i; 889 if (shdr[i].sh_type == SHT_PROGBITS 890 #ifdef __amd64__ 891 || shdr[i].sh_type == SHT_X86_64_UNWIND 892 #endif 893 ) { 894 error = vn_rdwr(UIO_READ, nd->ni_vp, 895 ef->progtab[pb].addr, 896 shdr[i].sh_size, shdr[i].sh_offset, 897 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 898 NOCRED, &resid, td); 899 if (error) 900 goto out; 901 if (resid != 0){ 902 error = EINVAL; 903 goto out; 904 } 905 /* Initialize the per-cpu or vnet area. */ 906 if (ef->progtab[pb].addr != (void *)mapbase && 907 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 908 dpcpu_copy(ef->progtab[pb].addr, 909 shdr[i].sh_size); 910 #ifdef VIMAGE 911 else if (ef->progtab[pb].addr != 912 (void *)mapbase && 913 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 914 vnet_data_copy(ef->progtab[pb].addr, 915 shdr[i].sh_size); 916 #endif 917 } else 918 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 919 920 /* Update all symbol values with the offset. */ 921 for (j = 0; j < ef->ddbsymcnt; j++) { 922 es = &ef->ddbsymtab[j]; 923 if (es->st_shndx != i) 924 continue; 925 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 926 } 927 mapbase += shdr[i].sh_size; 928 pb++; 929 break; 930 case SHT_REL: 931 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 932 break; 933 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 934 M_WAITOK); 935 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 936 ef->reltab[rl].sec = shdr[i].sh_info; 937 error = vn_rdwr(UIO_READ, nd->ni_vp, 938 (void *)ef->reltab[rl].rel, 939 shdr[i].sh_size, shdr[i].sh_offset, 940 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 941 &resid, td); 942 if (error) 943 goto out; 944 if (resid != 0){ 945 error = EINVAL; 946 goto out; 947 } 948 rl++; 949 break; 950 case SHT_RELA: 951 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 952 break; 953 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 954 M_WAITOK); 955 ef->relatab[ra].nrela = 956 shdr[i].sh_size / sizeof(Elf_Rela); 957 ef->relatab[ra].sec = shdr[i].sh_info; 958 error = vn_rdwr(UIO_READ, nd->ni_vp, 959 (void *)ef->relatab[ra].rela, 960 shdr[i].sh_size, shdr[i].sh_offset, 961 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 962 &resid, td); 963 if (error) 964 goto out; 965 if (resid != 0){ 966 error = EINVAL; 967 goto out; 968 } 969 ra++; 970 break; 971 } 972 } 973 if (pb != ef->nprogtab) { 974 link_elf_error(filename, "lost progbits"); 975 error = ENOEXEC; 976 goto out; 977 } 978 if (rl != ef->nreltab) { 979 link_elf_error(filename, "lost reltab"); 980 error = ENOEXEC; 981 goto out; 982 } 983 if (ra != ef->nrelatab) { 984 link_elf_error(filename, "lost relatab"); 985 error = ENOEXEC; 986 goto out; 987 } 988 if (mapbase != (vm_offset_t)ef->address + mapsize) { 989 printf( 990 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 991 filename != NULL ? filename : "<none>", 992 (u_long)mapbase, ef->address, (u_long)mapsize, 993 (u_long)(vm_offset_t)ef->address + mapsize); 994 error = ENOMEM; 995 goto out; 996 } 997 998 /* Local intra-module relocations */ 999 error = link_elf_reloc_local(lf, false); 1000 if (error != 0) 1001 goto out; 1002 1003 /* Pull in dependencies */ 1004 VOP_UNLOCK(nd->ni_vp, 0); 1005 error = linker_load_dependencies(lf); 1006 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 1007 if (error) 1008 goto out; 1009 1010 /* External relocations */ 1011 error = relocate_file(ef); 1012 if (error) 1013 goto out; 1014 1015 /* Notify MD code that a module is being loaded. */ 1016 error = elf_cpu_load_file(lf); 1017 if (error) 1018 goto out; 1019 1020 #if defined(__i386__) || defined(__amd64__) 1021 /* Now ifuncs. */ 1022 error = link_elf_reloc_local(lf, true); 1023 if (error != 0) 1024 goto out; 1025 #endif 1026 1027 /* Invoke .ctors */ 1028 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 1029 1030 *result = lf; 1031 1032 out: 1033 VOP_UNLOCK(nd->ni_vp, 0); 1034 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 1035 free(nd, M_TEMP); 1036 if (error && lf) 1037 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1038 free(hdr, M_LINKER); 1039 1040 return error; 1041 } 1042 1043 static void 1044 link_elf_unload_file(linker_file_t file) 1045 { 1046 elf_file_t ef = (elf_file_t) file; 1047 u_int i; 1048 1049 /* Notify MD code that a module is being unloaded. */ 1050 elf_cpu_unload_file(file); 1051 1052 if (ef->progtab) { 1053 for (i = 0; i < ef->nprogtab; i++) { 1054 if (ef->progtab[i].size == 0) 1055 continue; 1056 if (ef->progtab[i].name == NULL) 1057 continue; 1058 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 1059 dpcpu_free(ef->progtab[i].addr, 1060 ef->progtab[i].size); 1061 #ifdef VIMAGE 1062 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 1063 vnet_data_free(ef->progtab[i].addr, 1064 ef->progtab[i].size); 1065 #endif 1066 } 1067 } 1068 if (ef->preloaded) { 1069 free(ef->reltab, M_LINKER); 1070 free(ef->relatab, M_LINKER); 1071 free(ef->progtab, M_LINKER); 1072 free(ef->ctftab, M_LINKER); 1073 free(ef->ctfoff, M_LINKER); 1074 free(ef->typoff, M_LINKER); 1075 if (file->pathname != NULL) 1076 preload_delete_name(file->pathname); 1077 return; 1078 } 1079 1080 for (i = 0; i < ef->nreltab; i++) 1081 free(ef->reltab[i].rel, M_LINKER); 1082 for (i = 0; i < ef->nrelatab; i++) 1083 free(ef->relatab[i].rela, M_LINKER); 1084 free(ef->reltab, M_LINKER); 1085 free(ef->relatab, M_LINKER); 1086 free(ef->progtab, M_LINKER); 1087 1088 if (ef->object) { 1089 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1090 (vm_offset_t) ef->address + 1091 (ef->object->size << PAGE_SHIFT)); 1092 } 1093 free(ef->e_shdr, M_LINKER); 1094 free(ef->ddbsymtab, M_LINKER); 1095 free(ef->ddbstrtab, M_LINKER); 1096 free(ef->shstrtab, M_LINKER); 1097 free(ef->ctftab, M_LINKER); 1098 free(ef->ctfoff, M_LINKER); 1099 free(ef->typoff, M_LINKER); 1100 } 1101 1102 static const char * 1103 symbol_name(elf_file_t ef, Elf_Size r_info) 1104 { 1105 const Elf_Sym *ref; 1106 1107 if (ELF_R_SYM(r_info)) { 1108 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1109 return ef->ddbstrtab + ref->st_name; 1110 } else 1111 return NULL; 1112 } 1113 1114 static Elf_Addr 1115 findbase(elf_file_t ef, int sec) 1116 { 1117 int i; 1118 Elf_Addr base = 0; 1119 1120 for (i = 0; i < ef->nprogtab; i++) { 1121 if (sec == ef->progtab[i].sec) { 1122 base = (Elf_Addr)ef->progtab[i].addr; 1123 break; 1124 } 1125 } 1126 return base; 1127 } 1128 1129 static int 1130 relocate_file(elf_file_t ef) 1131 { 1132 const Elf_Rel *rellim; 1133 const Elf_Rel *rel; 1134 const Elf_Rela *relalim; 1135 const Elf_Rela *rela; 1136 const char *symname; 1137 const Elf_Sym *sym; 1138 int i; 1139 Elf_Size symidx; 1140 Elf_Addr base; 1141 1142 1143 /* Perform relocations without addend if there are any: */ 1144 for (i = 0; i < ef->nreltab; i++) { 1145 rel = ef->reltab[i].rel; 1146 if (rel == NULL) { 1147 link_elf_error(ef->lf.filename, "lost a reltab!"); 1148 return (ENOEXEC); 1149 } 1150 rellim = rel + ef->reltab[i].nrel; 1151 base = findbase(ef, ef->reltab[i].sec); 1152 if (base == 0) { 1153 link_elf_error(ef->lf.filename, "lost base for reltab"); 1154 return (ENOEXEC); 1155 } 1156 for ( ; rel < rellim; rel++) { 1157 symidx = ELF_R_SYM(rel->r_info); 1158 if (symidx >= ef->ddbsymcnt) 1159 continue; 1160 sym = ef->ddbsymtab + symidx; 1161 /* Local relocs are already done */ 1162 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1163 continue; 1164 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1165 elf_obj_lookup)) { 1166 symname = symbol_name(ef, rel->r_info); 1167 printf("link_elf_obj: symbol %s undefined\n", 1168 symname); 1169 return (ENOENT); 1170 } 1171 } 1172 } 1173 1174 /* Perform relocations with addend if there are any: */ 1175 for (i = 0; i < ef->nrelatab; i++) { 1176 rela = ef->relatab[i].rela; 1177 if (rela == NULL) { 1178 link_elf_error(ef->lf.filename, "lost a relatab!"); 1179 return (ENOEXEC); 1180 } 1181 relalim = rela + ef->relatab[i].nrela; 1182 base = findbase(ef, ef->relatab[i].sec); 1183 if (base == 0) { 1184 link_elf_error(ef->lf.filename, 1185 "lost base for relatab"); 1186 return (ENOEXEC); 1187 } 1188 for ( ; rela < relalim; rela++) { 1189 symidx = ELF_R_SYM(rela->r_info); 1190 if (symidx >= ef->ddbsymcnt) 1191 continue; 1192 sym = ef->ddbsymtab + symidx; 1193 /* Local relocs are already done */ 1194 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1195 continue; 1196 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1197 elf_obj_lookup)) { 1198 symname = symbol_name(ef, rela->r_info); 1199 printf("link_elf_obj: symbol %s undefined\n", 1200 symname); 1201 return (ENOENT); 1202 } 1203 } 1204 } 1205 1206 /* 1207 * Only clean SHN_FBSD_CACHED for successful return. If we 1208 * modified symbol table for the object but found an 1209 * unresolved symbol, there is no reason to roll back. 1210 */ 1211 elf_obj_cleanup_globals_cache(ef); 1212 1213 return (0); 1214 } 1215 1216 static int 1217 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1218 { 1219 elf_file_t ef = (elf_file_t) lf; 1220 const Elf_Sym *symp; 1221 const char *strp; 1222 int i; 1223 1224 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1225 strp = ef->ddbstrtab + symp->st_name; 1226 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1227 *sym = (c_linker_sym_t) symp; 1228 return 0; 1229 } 1230 } 1231 return ENOENT; 1232 } 1233 1234 static int 1235 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1236 linker_symval_t *symval) 1237 { 1238 elf_file_t ef; 1239 const Elf_Sym *es; 1240 caddr_t val; 1241 1242 ef = (elf_file_t) lf; 1243 es = (const Elf_Sym*) sym; 1244 val = (caddr_t)es->st_value; 1245 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1246 symval->name = ef->ddbstrtab + es->st_name; 1247 val = (caddr_t)es->st_value; 1248 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1249 val = ((caddr_t (*)(void))val)(); 1250 symval->value = val; 1251 symval->size = es->st_size; 1252 return 0; 1253 } 1254 return ENOENT; 1255 } 1256 1257 static int 1258 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1259 c_linker_sym_t *sym, long *diffp) 1260 { 1261 elf_file_t ef = (elf_file_t) lf; 1262 u_long off = (uintptr_t) (void *) value; 1263 u_long diff = off; 1264 u_long st_value; 1265 const Elf_Sym *es; 1266 const Elf_Sym *best = NULL; 1267 int i; 1268 1269 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1270 if (es->st_name == 0) 1271 continue; 1272 st_value = es->st_value; 1273 if (off >= st_value) { 1274 if (off - st_value < diff) { 1275 diff = off - st_value; 1276 best = es; 1277 if (diff == 0) 1278 break; 1279 } else if (off - st_value == diff) { 1280 best = es; 1281 } 1282 } 1283 } 1284 if (best == NULL) 1285 *diffp = off; 1286 else 1287 *diffp = diff; 1288 *sym = (c_linker_sym_t) best; 1289 1290 return 0; 1291 } 1292 1293 /* 1294 * Look up a linker set on an ELF system. 1295 */ 1296 static int 1297 link_elf_lookup_set(linker_file_t lf, const char *name, 1298 void ***startp, void ***stopp, int *countp) 1299 { 1300 elf_file_t ef = (elf_file_t)lf; 1301 void **start, **stop; 1302 int i, count; 1303 1304 /* Relative to section number */ 1305 for (i = 0; i < ef->nprogtab; i++) { 1306 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1307 strcmp(ef->progtab[i].name + 4, name) == 0) { 1308 start = (void **)ef->progtab[i].addr; 1309 stop = (void **)((char *)ef->progtab[i].addr + 1310 ef->progtab[i].size); 1311 count = stop - start; 1312 if (startp) 1313 *startp = start; 1314 if (stopp) 1315 *stopp = stop; 1316 if (countp) 1317 *countp = count; 1318 return (0); 1319 } 1320 } 1321 return (ESRCH); 1322 } 1323 1324 static int 1325 link_elf_each_function_name(linker_file_t file, 1326 int (*callback)(const char *, void *), void *opaque) 1327 { 1328 elf_file_t ef = (elf_file_t)file; 1329 const Elf_Sym *symp; 1330 int i, error; 1331 1332 /* Exhaustive search */ 1333 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1334 if (symp->st_value != 0 && 1335 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1336 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1337 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1338 if (error) 1339 return (error); 1340 } 1341 } 1342 return (0); 1343 } 1344 1345 static int 1346 link_elf_each_function_nameval(linker_file_t file, 1347 linker_function_nameval_callback_t callback, void *opaque) 1348 { 1349 linker_symval_t symval; 1350 elf_file_t ef = (elf_file_t)file; 1351 const Elf_Sym* symp; 1352 int i, error; 1353 1354 /* Exhaustive search */ 1355 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1356 if (symp->st_value != 0 && 1357 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1358 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1359 error = link_elf_symbol_values(file, 1360 (c_linker_sym_t)symp, &symval); 1361 if (error) 1362 return (error); 1363 error = callback(file, i, &symval, opaque); 1364 if (error) 1365 return (error); 1366 } 1367 } 1368 return (0); 1369 } 1370 1371 static void 1372 elf_obj_cleanup_globals_cache(elf_file_t ef) 1373 { 1374 Elf_Sym *sym; 1375 Elf_Size i; 1376 1377 for (i = 0; i < ef->ddbsymcnt; i++) { 1378 sym = ef->ddbsymtab + i; 1379 if (sym->st_shndx == SHN_FBSD_CACHED) { 1380 sym->st_shndx = SHN_UNDEF; 1381 sym->st_value = 0; 1382 } 1383 } 1384 } 1385 1386 /* 1387 * Symbol lookup function that can be used when the symbol index is known (ie 1388 * in relocations). It uses the symbol index instead of doing a fully fledged 1389 * hash table based lookup when such is valid. For example for local symbols. 1390 * This is not only more efficient, it's also more correct. It's not always 1391 * the case that the symbol can be found through the hash table. 1392 */ 1393 static int 1394 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1395 { 1396 elf_file_t ef = (elf_file_t)lf; 1397 Elf_Sym *sym; 1398 const char *symbol; 1399 Elf_Addr res1; 1400 1401 /* Don't even try to lookup the symbol if the index is bogus. */ 1402 if (symidx >= ef->ddbsymcnt) { 1403 *res = 0; 1404 return (EINVAL); 1405 } 1406 1407 sym = ef->ddbsymtab + symidx; 1408 1409 /* Quick answer if there is a definition included. */ 1410 if (sym->st_shndx != SHN_UNDEF) { 1411 res1 = (Elf_Addr)sym->st_value; 1412 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC) 1413 res1 = ((Elf_Addr (*)(void))res1)(); 1414 *res = res1; 1415 return (0); 1416 } 1417 1418 /* If we get here, then it is undefined and needs a lookup. */ 1419 switch (ELF_ST_BIND(sym->st_info)) { 1420 case STB_LOCAL: 1421 /* Local, but undefined? huh? */ 1422 *res = 0; 1423 return (EINVAL); 1424 1425 case STB_GLOBAL: 1426 case STB_WEAK: 1427 /* Relative to Data or Function name */ 1428 symbol = ef->ddbstrtab + sym->st_name; 1429 1430 /* Force a lookup failure if the symbol name is bogus. */ 1431 if (*symbol == 0) { 1432 *res = 0; 1433 return (EINVAL); 1434 } 1435 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1436 1437 /* 1438 * Cache global lookups during module relocation. The failure 1439 * case is particularly expensive for callers, who must scan 1440 * through the entire globals table doing strcmp(). Cache to 1441 * avoid doing such work repeatedly. 1442 * 1443 * After relocation is complete, undefined globals will be 1444 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1445 * above. 1446 */ 1447 if (res1 != 0) { 1448 sym->st_shndx = SHN_FBSD_CACHED; 1449 sym->st_value = res1; 1450 *res = res1; 1451 return (0); 1452 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1453 sym->st_value = 0; 1454 *res = 0; 1455 return (0); 1456 } 1457 return (EINVAL); 1458 1459 default: 1460 return (EINVAL); 1461 } 1462 } 1463 1464 static void 1465 link_elf_fix_link_set(elf_file_t ef) 1466 { 1467 static const char startn[] = "__start_"; 1468 static const char stopn[] = "__stop_"; 1469 Elf_Sym *sym; 1470 const char *sym_name, *linkset_name; 1471 Elf_Addr startp, stopp; 1472 Elf_Size symidx; 1473 int start, i; 1474 1475 startp = stopp = 0; 1476 for (symidx = 1 /* zero entry is special */; 1477 symidx < ef->ddbsymcnt; symidx++) { 1478 sym = ef->ddbsymtab + symidx; 1479 if (sym->st_shndx != SHN_UNDEF) 1480 continue; 1481 1482 sym_name = ef->ddbstrtab + sym->st_name; 1483 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1484 start = 1; 1485 linkset_name = sym_name + sizeof(startn) - 1; 1486 } 1487 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1488 start = 0; 1489 linkset_name = sym_name + sizeof(stopn) - 1; 1490 } 1491 else 1492 continue; 1493 1494 for (i = 0; i < ef->nprogtab; i++) { 1495 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1496 startp = (Elf_Addr)ef->progtab[i].addr; 1497 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1498 break; 1499 } 1500 } 1501 if (i == ef->nprogtab) 1502 continue; 1503 1504 sym->st_value = start ? startp : stopp; 1505 sym->st_shndx = i; 1506 } 1507 } 1508 1509 static int 1510 link_elf_reloc_local(linker_file_t lf, bool ifuncs) 1511 { 1512 elf_file_t ef = (elf_file_t)lf; 1513 const Elf_Rel *rellim; 1514 const Elf_Rel *rel; 1515 const Elf_Rela *relalim; 1516 const Elf_Rela *rela; 1517 const Elf_Sym *sym; 1518 Elf_Addr base; 1519 int i; 1520 Elf_Size symidx; 1521 1522 link_elf_fix_link_set(ef); 1523 1524 /* Perform relocations without addend if there are any: */ 1525 for (i = 0; i < ef->nreltab; i++) { 1526 rel = ef->reltab[i].rel; 1527 if (rel == NULL) { 1528 link_elf_error(ef->lf.filename, "lost a reltab"); 1529 return (ENOEXEC); 1530 } 1531 rellim = rel + ef->reltab[i].nrel; 1532 base = findbase(ef, ef->reltab[i].sec); 1533 if (base == 0) { 1534 link_elf_error(ef->lf.filename, "lost base for reltab"); 1535 return (ENOEXEC); 1536 } 1537 for ( ; rel < rellim; rel++) { 1538 symidx = ELF_R_SYM(rel->r_info); 1539 if (symidx >= ef->ddbsymcnt) 1540 continue; 1541 sym = ef->ddbsymtab + symidx; 1542 /* Only do local relocs */ 1543 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1544 continue; 1545 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1546 elf_is_ifunc_reloc(rel->r_info)) == ifuncs) 1547 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1548 elf_obj_lookup); 1549 } 1550 } 1551 1552 /* Perform relocations with addend if there are any: */ 1553 for (i = 0; i < ef->nrelatab; i++) { 1554 rela = ef->relatab[i].rela; 1555 if (rela == NULL) { 1556 link_elf_error(ef->lf.filename, "lost a relatab!"); 1557 return (ENOEXEC); 1558 } 1559 relalim = rela + ef->relatab[i].nrela; 1560 base = findbase(ef, ef->relatab[i].sec); 1561 if (base == 0) { 1562 link_elf_error(ef->lf.filename, "lost base for reltab"); 1563 return (ENOEXEC); 1564 } 1565 for ( ; rela < relalim; rela++) { 1566 symidx = ELF_R_SYM(rela->r_info); 1567 if (symidx >= ef->ddbsymcnt) 1568 continue; 1569 sym = ef->ddbsymtab + symidx; 1570 /* Only do local relocs */ 1571 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1572 continue; 1573 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1574 elf_is_ifunc_reloc(rela->r_info)) == ifuncs) 1575 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1576 elf_obj_lookup); 1577 } 1578 } 1579 return (0); 1580 } 1581 1582 static long 1583 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1584 { 1585 elf_file_t ef = (elf_file_t)lf; 1586 1587 *symtab = ef->ddbsymtab; 1588 1589 if (*symtab == NULL) 1590 return (0); 1591 1592 return (ef->ddbsymcnt); 1593 } 1594 1595 static long 1596 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1597 { 1598 elf_file_t ef = (elf_file_t)lf; 1599 1600 *strtab = ef->ddbstrtab; 1601 1602 if (*strtab == NULL) 1603 return (0); 1604 1605 return (ef->ddbstrcnt); 1606 } 1607