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