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 #include "opt_mac.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/mac.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 <vm/vm.h> 51 #include <vm/vm_param.h> 52 #include <vm/vm_object.h> 53 #include <vm/vm_kern.h> 54 #include <vm/vm_extern.h> 55 #include <vm/pmap.h> 56 #include <vm/vm_map.h> 57 58 #include <sys/link_elf.h> 59 60 #include "linker_if.h" 61 62 typedef struct { 63 void *addr; 64 Elf_Off size; 65 int flags; 66 int sec; /* Original section */ 67 char *name; 68 } Elf_progent; 69 70 typedef struct { 71 Elf_Rel *rel; 72 int nrel; 73 int sec; 74 } Elf_relent; 75 76 typedef struct { 77 Elf_Rela *rela; 78 int nrela; 79 int sec; 80 } Elf_relaent; 81 82 83 typedef struct elf_file { 84 struct linker_file lf; /* Common fields */ 85 86 int preloaded; 87 caddr_t address; /* Relocation address */ 88 vm_object_t object; /* VM object to hold file pages */ 89 Elf_Shdr *e_shdr; 90 91 Elf_progent *progtab; 92 int nprogtab; 93 94 Elf_relaent *relatab; 95 int nrela; 96 97 Elf_relent *reltab; 98 int nrel; 99 100 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 101 long ddbsymcnt; /* Number of symbols */ 102 caddr_t ddbstrtab; /* String table */ 103 long ddbstrcnt; /* number of bytes in string table */ 104 105 caddr_t shstrtab; /* Section name string table */ 106 long shstrcnt; /* number of bytes in string table */ 107 108 } *elf_file_t; 109 110 static int link_elf_link_preload(linker_class_t cls, 111 const char *, linker_file_t *); 112 static int link_elf_link_preload_finish(linker_file_t); 113 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); 114 static int link_elf_lookup_symbol(linker_file_t, const char *, 115 c_linker_sym_t *); 116 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 117 linker_symval_t *); 118 static int link_elf_search_symbol(linker_file_t, caddr_t value, 119 c_linker_sym_t *sym, long *diffp); 120 121 static void link_elf_unload_file(linker_file_t); 122 static int link_elf_lookup_set(linker_file_t, const char *, 123 void ***, void ***, int *); 124 static int link_elf_each_function_name(linker_file_t, 125 int (*)(const char *, void *), void *); 126 static void link_elf_reloc_local(linker_file_t); 127 128 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps); 129 130 static kobj_method_t link_elf_methods[] = { 131 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 132 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 133 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 134 KOBJMETHOD(linker_unload, link_elf_unload_file), 135 KOBJMETHOD(linker_load_file, link_elf_load_file), 136 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 137 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 138 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 139 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 140 { 0, 0 } 141 }; 142 143 static struct linker_class link_elf_class = { 144 #if ELF_TARG_CLASS == ELFCLASS32 145 "elf32_obj", 146 #else 147 "elf64_obj", 148 #endif 149 link_elf_methods, sizeof(struct elf_file) 150 }; 151 152 static int relocate_file(elf_file_t ef); 153 154 static void 155 link_elf_error(const char *s) 156 { 157 printf("kldload: %s\n", s); 158 } 159 160 static void 161 link_elf_init(void *arg) 162 { 163 164 linker_add_class(&link_elf_class); 165 } 166 167 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0); 168 169 static int 170 link_elf_link_preload(linker_class_t cls, const char *filename, 171 linker_file_t *result) 172 { 173 Elf_Ehdr *hdr; 174 Elf_Shdr *shdr; 175 Elf_Sym *es; 176 void *modptr, *baseptr, *sizeptr; 177 char *type; 178 elf_file_t ef; 179 linker_file_t lf; 180 Elf_Addr off; 181 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 182 183 /* Look to see if we have the file preloaded */ 184 modptr = preload_search_by_name(filename); 185 if (modptr == NULL) 186 return ENOENT; 187 188 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 189 baseptr = preload_search_info(modptr, MODINFO_ADDR); 190 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 191 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 192 MODINFOMD_ELFHDR); 193 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 194 MODINFOMD_SHDR); 195 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) 196 " obj module") != 0 && 197 strcmp(type, "elf obj module") != 0)) { 198 return (EFTYPE); 199 } 200 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 201 shdr == NULL) 202 return (EINVAL); 203 204 lf = linker_make_file(filename, &link_elf_class); 205 if (lf == NULL) 206 return (ENOMEM); 207 208 ef = (elf_file_t)lf; 209 ef->preloaded = 1; 210 ef->address = *(caddr_t *)baseptr; 211 lf->address = *(caddr_t *)baseptr; 212 lf->size = *(size_t *)sizeptr; 213 214 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 215 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 216 hdr->e_ident[EI_VERSION] != EV_CURRENT || 217 hdr->e_version != EV_CURRENT || 218 hdr->e_type != ET_REL || 219 hdr->e_machine != ELF_TARG_MACH) { 220 error = EFTYPE; 221 goto out; 222 } 223 ef->e_shdr = shdr; 224 225 /* Scan the section header for information and table sizing. */ 226 symtabindex = -1; 227 symstrindex = -1; 228 for (i = 0; i < hdr->e_shnum; i++) { 229 switch (shdr[i].sh_type) { 230 case SHT_PROGBITS: 231 case SHT_NOBITS: 232 ef->nprogtab++; 233 break; 234 case SHT_SYMTAB: 235 symtabindex = i; 236 symstrindex = shdr[i].sh_link; 237 break; 238 case SHT_REL: 239 ef->nrel++; 240 break; 241 case SHT_RELA: 242 ef->nrela++; 243 break; 244 } 245 } 246 247 shstrindex = hdr->e_shstrndx; 248 if (ef->nprogtab == 0 || symstrindex < 0 || 249 symstrindex >= hdr->e_shnum || 250 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 251 shstrindex >= hdr->e_shnum || 252 shdr[shstrindex].sh_type != SHT_STRTAB) { 253 printf("%s: bad/missing section headers\n", filename); 254 error = ENOEXEC; 255 goto out; 256 } 257 258 /* Allocate space for tracking the load chunks */ 259 if (ef->nprogtab != 0) 260 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 261 M_LINKER, M_WAITOK | M_ZERO); 262 if (ef->nrel != 0) 263 ef->reltab = malloc(ef->nrel * sizeof(*ef->reltab), M_LINKER, 264 M_WAITOK | M_ZERO); 265 if (ef->nrela != 0) 266 ef->relatab = malloc(ef->nrela * sizeof(*ef->relatab), M_LINKER, 267 M_WAITOK | M_ZERO); 268 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 269 (ef->nrel != 0 && ef->reltab == NULL) || 270 (ef->nrela != 0 && ef->relatab == NULL)) { 271 error = ENOMEM; 272 goto out; 273 } 274 275 /* XXX, relocate the sh_addr fields saved by the loader. */ 276 off = 0; 277 for (i = 0; i < hdr->e_shnum; i++) { 278 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 279 off = shdr[i].sh_addr; 280 } 281 for (i = 0; i < hdr->e_shnum; i++) { 282 if (shdr[i].sh_addr != 0) 283 shdr[i].sh_addr = shdr[i].sh_addr - off + 284 (Elf_Addr)ef->address; 285 } 286 287 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 288 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 289 ef->ddbstrcnt = shdr[symstrindex].sh_size; 290 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 291 ef->shstrcnt = shdr[shstrindex].sh_size; 292 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 293 294 /* Now fill out progtab and the relocation tables. */ 295 pb = 0; 296 rl = 0; 297 ra = 0; 298 for (i = 0; i < hdr->e_shnum; i++) { 299 switch (shdr[i].sh_type) { 300 case SHT_PROGBITS: 301 case SHT_NOBITS: 302 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 303 if (shdr[i].sh_type == SHT_PROGBITS) 304 ef->progtab[pb].name = "<<PROGBITS>>"; 305 else 306 ef->progtab[pb].name = "<<NOBITS>>"; 307 ef->progtab[pb].size = shdr[i].sh_size; 308 ef->progtab[pb].sec = i; 309 if (ef->shstrtab && shdr[i].sh_name != 0) 310 ef->progtab[pb].name = 311 ef->shstrtab + shdr[i].sh_name; 312 313 /* Update all symbol values with the offset. */ 314 for (j = 0; j < ef->ddbsymcnt; j++) { 315 es = &ef->ddbsymtab[j]; 316 if (es->st_shndx != i) 317 continue; 318 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 319 } 320 pb++; 321 break; 322 case SHT_REL: 323 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 324 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 325 ef->reltab[rl].sec = shdr[i].sh_info; 326 rl++; 327 break; 328 case SHT_RELA: 329 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 330 ef->relatab[ra].nrela = 331 shdr[i].sh_size / sizeof(Elf_Rela); 332 ef->relatab[ra].sec = shdr[i].sh_info; 333 ra++; 334 break; 335 } 336 } 337 if (pb != ef->nprogtab) 338 panic("lost progbits"); 339 if (rl != ef->nrel) 340 panic("lost rel"); 341 if (ra != ef->nrela) 342 panic("lost rela"); 343 344 /* Local intra-module relocations */ 345 link_elf_reloc_local(lf); 346 347 *result = lf; 348 return (0); 349 350 out: 351 /* preload not done this way */ 352 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 353 return (error); 354 } 355 356 static int 357 link_elf_link_preload_finish(linker_file_t lf) 358 { 359 elf_file_t ef; 360 int error; 361 362 ef = (elf_file_t)lf; 363 error = relocate_file(ef); 364 if (error) 365 return error; 366 367 /* Notify MD code that a module is being loaded. */ 368 error = elf_cpu_load_file(lf); 369 if (error) 370 return (error); 371 372 return (0); 373 } 374 375 static int 376 link_elf_load_file(linker_class_t cls, const char *filename, 377 linker_file_t *result) 378 { 379 struct nameidata nd; 380 struct thread *td = curthread; /* XXX */ 381 Elf_Ehdr *hdr; 382 Elf_Shdr *shdr; 383 Elf_Sym *es; 384 int nbytes, i, j; 385 vm_offset_t mapbase; 386 size_t mapsize; 387 int error = 0; 388 int resid, flags; 389 elf_file_t ef; 390 linker_file_t lf; 391 int symtabindex; 392 int symstrindex; 393 int shstrindex; 394 int nsym; 395 int pb, rl, ra; 396 int alignmask; 397 int vfslocked; 398 399 shdr = NULL; 400 lf = NULL; 401 mapsize = 0; 402 hdr = NULL; 403 404 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td); 405 flags = FREAD; 406 error = vn_open(&nd, &flags, 0, -1); 407 if (error) 408 return error; 409 vfslocked = NDHASGIANT(&nd); 410 NDFREE(&nd, NDF_ONLY_PNBUF); 411 #ifdef MAC 412 error = mac_check_kld_load(td->td_ucred, nd.ni_vp); 413 if (error) { 414 goto out; 415 } 416 #endif 417 418 /* Read the elf header from the file. */ 419 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 420 if (hdr == NULL) { 421 error = ENOMEM; 422 goto out; 423 } 424 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0, 425 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 426 &resid, td); 427 if (error) 428 goto out; 429 if (resid != 0){ 430 error = ENOEXEC; 431 goto out; 432 } 433 434 if (!IS_ELF(*hdr)) { 435 error = ENOEXEC; 436 goto out; 437 } 438 439 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 440 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 441 link_elf_error("Unsupported file layout"); 442 error = ENOEXEC; 443 goto out; 444 } 445 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 446 || hdr->e_version != EV_CURRENT) { 447 link_elf_error("Unsupported file version"); 448 error = ENOEXEC; 449 goto out; 450 } 451 if (hdr->e_type != ET_REL) { 452 link_elf_error("Unsupported file type"); 453 error = ENOEXEC; 454 goto out; 455 } 456 if (hdr->e_machine != ELF_TARG_MACH) { 457 link_elf_error("Unsupported machine"); 458 error = ENOEXEC; 459 goto out; 460 } 461 462 lf = linker_make_file(filename, &link_elf_class); 463 if (!lf) { 464 error = ENOMEM; 465 goto out; 466 } 467 ef = (elf_file_t) lf; 468 ef->nprogtab = 0; 469 ef->e_shdr = 0; 470 ef->nrel = 0; 471 ef->nrela = 0; 472 473 /* Allocate and read in the section header */ 474 nbytes = hdr->e_shnum * hdr->e_shentsize; 475 if (nbytes == 0 || hdr->e_shoff == 0 || 476 hdr->e_shentsize != sizeof(Elf_Shdr)) { 477 error = ENOEXEC; 478 goto out; 479 } 480 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 481 if (shdr == NULL) { 482 error = ENOMEM; 483 goto out; 484 } 485 ef->e_shdr = shdr; 486 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff, 487 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); 488 if (error) 489 goto out; 490 if (resid) { 491 error = ENOEXEC; 492 goto out; 493 } 494 495 /* Scan the section header for information and table sizing. */ 496 nsym = 0; 497 symtabindex = -1; 498 symstrindex = -1; 499 for (i = 0; i < hdr->e_shnum; i++) { 500 switch (shdr[i].sh_type) { 501 case SHT_PROGBITS: 502 case SHT_NOBITS: 503 ef->nprogtab++; 504 break; 505 case SHT_SYMTAB: 506 nsym++; 507 symtabindex = i; 508 symstrindex = shdr[i].sh_link; 509 break; 510 case SHT_REL: 511 ef->nrel++; 512 break; 513 case SHT_RELA: 514 ef->nrela++; 515 break; 516 case SHT_STRTAB: 517 break; 518 } 519 } 520 if (ef->nprogtab == 0) { 521 link_elf_error("file has no contents"); 522 error = ENOEXEC; 523 goto out; 524 } 525 if (nsym != 1) { 526 /* Only allow one symbol table for now */ 527 link_elf_error("file has no valid symbol table"); 528 error = ENOEXEC; 529 goto out; 530 } 531 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 532 shdr[symstrindex].sh_type != SHT_STRTAB) { 533 link_elf_error("file has invalid symbol strings"); 534 error = ENOEXEC; 535 goto out; 536 } 537 538 /* Allocate space for tracking the load chunks */ 539 if (ef->nprogtab != 0) 540 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 541 M_LINKER, M_WAITOK | M_ZERO); 542 if (ef->nrel != 0) 543 ef->reltab = malloc(ef->nrel * sizeof(*ef->reltab), M_LINKER, 544 M_WAITOK | M_ZERO); 545 if (ef->nrela != 0) 546 ef->relatab = malloc(ef->nrela * sizeof(*ef->relatab), M_LINKER, 547 M_WAITOK | M_ZERO); 548 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 549 (ef->nrel != 0 && ef->reltab == NULL) || 550 (ef->nrela != 0 && ef->relatab == NULL)) { 551 error = ENOMEM; 552 goto out; 553 } 554 555 if (symtabindex == -1) 556 panic("lost symbol table index"); 557 /* Allocate space for and load the symbol table */ 558 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 559 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 560 if (ef->ddbsymtab == NULL) { 561 error = ENOMEM; 562 goto out; 563 } 564 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab, 565 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 566 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 567 &resid, td); 568 if (error) 569 goto out; 570 if (resid != 0){ 571 error = EINVAL; 572 goto out; 573 } 574 575 if (symstrindex == -1) 576 panic("lost symbol string index"); 577 /* Allocate space for and load the symbol strings */ 578 ef->ddbstrcnt = shdr[symstrindex].sh_size; 579 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 580 if (ef->ddbstrtab == NULL) { 581 error = ENOMEM; 582 goto out; 583 } 584 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab, 585 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 586 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 587 &resid, td); 588 if (error) 589 goto out; 590 if (resid != 0){ 591 error = EINVAL; 592 goto out; 593 } 594 595 /* Do we have a string table for the section names? */ 596 shstrindex = -1; 597 if (hdr->e_shstrndx != 0 && 598 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 599 shstrindex = hdr->e_shstrndx; 600 ef->shstrcnt = shdr[shstrindex].sh_size; 601 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 602 M_WAITOK); 603 if (ef->shstrtab == NULL) { 604 error = ENOMEM; 605 goto out; 606 } 607 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab, 608 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 609 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 610 &resid, td); 611 if (error) 612 goto out; 613 if (resid != 0){ 614 error = EINVAL; 615 goto out; 616 } 617 } 618 619 /* Size up code/data(progbits) and bss(nobits). */ 620 alignmask = 0; 621 for (i = 0; i < hdr->e_shnum; i++) { 622 switch (shdr[i].sh_type) { 623 case SHT_PROGBITS: 624 case SHT_NOBITS: 625 alignmask = shdr[i].sh_addralign - 1; 626 mapsize += alignmask; 627 mapsize &= ~alignmask; 628 mapsize += shdr[i].sh_size; 629 break; 630 } 631 } 632 633 /* 634 * We know how much space we need for the text/data/bss/etc. 635 * This stuff needs to be in a single chunk so that profiling etc 636 * can get the bounds and gdb can associate offsets with modules 637 */ 638 ef->object = vm_object_allocate(OBJT_DEFAULT, 639 round_page(mapsize) >> PAGE_SHIFT); 640 if (ef->object == NULL) { 641 error = ENOMEM; 642 goto out; 643 } 644 ef->address = (caddr_t) vm_map_min(kernel_map); 645 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 646 round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE); 647 if (error) { 648 vm_object_deallocate(ef->object); 649 ef->object = 0; 650 goto out; 651 } 652 653 /* Wire the pages */ 654 error = vm_map_wire(kernel_map, mapbase, 655 mapbase + round_page(mapsize), 656 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 657 if (error != KERN_SUCCESS) { 658 error = ENOMEM; 659 goto out; 660 } 661 662 /* Inform the kld system about the situation */ 663 lf->address = ef->address = (caddr_t)mapbase; 664 lf->size = mapsize; 665 666 /* 667 * Now load code/data(progbits), zero bss(nobits), allocate space for 668 * and load relocs 669 */ 670 pb = 0; 671 rl = 0; 672 ra = 0; 673 alignmask = 0; 674 for (i = 0; i < hdr->e_shnum; i++) { 675 switch (shdr[i].sh_type) { 676 case SHT_PROGBITS: 677 case SHT_NOBITS: 678 alignmask = shdr[i].sh_addralign - 1; 679 mapbase += alignmask; 680 mapbase &= ~alignmask; 681 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase; 682 if (shdr[i].sh_type == SHT_PROGBITS) { 683 ef->progtab[pb].name = "<<PROGBITS>>"; 684 error = vn_rdwr(UIO_READ, nd.ni_vp, 685 ef->progtab[pb].addr, 686 shdr[i].sh_size, shdr[i].sh_offset, 687 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 688 NOCRED, &resid, td); 689 if (error) 690 goto out; 691 if (resid != 0){ 692 error = EINVAL; 693 goto out; 694 } 695 } else { 696 ef->progtab[pb].name = "<<NOBITS>>"; 697 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 698 } 699 ef->progtab[pb].size = shdr[i].sh_size; 700 ef->progtab[pb].sec = i; 701 if (ef->shstrtab && shdr[i].sh_name != 0) 702 ef->progtab[pb].name = 703 ef->shstrtab + shdr[i].sh_name; 704 705 /* Update all symbol values with the offset. */ 706 for (j = 0; j < ef->ddbsymcnt; j++) { 707 es = &ef->ddbsymtab[j]; 708 if (es->st_shndx != i) 709 continue; 710 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 711 } 712 mapbase += shdr[i].sh_size; 713 pb++; 714 break; 715 case SHT_REL: 716 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 717 M_WAITOK); 718 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 719 ef->reltab[rl].sec = shdr[i].sh_info; 720 error = vn_rdwr(UIO_READ, nd.ni_vp, 721 (void *)ef->reltab[rl].rel, 722 shdr[i].sh_size, shdr[i].sh_offset, 723 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 724 &resid, td); 725 if (error) 726 goto out; 727 if (resid != 0){ 728 error = EINVAL; 729 goto out; 730 } 731 rl++; 732 break; 733 case SHT_RELA: 734 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 735 M_WAITOK); 736 ef->relatab[ra].nrela = 737 shdr[i].sh_size / sizeof(Elf_Rela); 738 ef->relatab[ra].sec = shdr[i].sh_info; 739 error = vn_rdwr(UIO_READ, nd.ni_vp, 740 (void *)ef->relatab[ra].rela, 741 shdr[i].sh_size, shdr[i].sh_offset, 742 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 743 &resid, td); 744 if (error) 745 goto out; 746 if (resid != 0){ 747 error = EINVAL; 748 goto out; 749 } 750 ra++; 751 break; 752 } 753 } 754 if (pb != ef->nprogtab) 755 panic("lost progbits"); 756 if (rl != ef->nrel) 757 panic("lost rel"); 758 if (ra != ef->nrela) 759 panic("lost rela"); 760 if (mapbase != (vm_offset_t)ef->address + mapsize) 761 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 762 mapbase, ef->address, mapsize, 763 (vm_offset_t)ef->address + mapsize); 764 765 /* Local intra-module relocations */ 766 link_elf_reloc_local(lf); 767 768 /* Pull in dependencies */ 769 error = linker_load_dependencies(lf); 770 if (error) 771 goto out; 772 773 /* External relocations */ 774 error = relocate_file(ef); 775 if (error) 776 goto out; 777 778 /* Notify MD code that a module is being loaded. */ 779 error = elf_cpu_load_file(lf); 780 if (error) 781 goto out; 782 783 *result = lf; 784 785 out: 786 if (error && lf) 787 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 788 if (hdr) 789 free(hdr, M_LINKER); 790 VOP_UNLOCK(nd.ni_vp, 0, td); 791 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 792 VFS_UNLOCK_GIANT(vfslocked); 793 794 return error; 795 } 796 797 static void 798 link_elf_unload_file(linker_file_t file) 799 { 800 elf_file_t ef = (elf_file_t) file; 801 int i; 802 803 /* Notify MD code that a module is being unloaded. */ 804 elf_cpu_unload_file(file); 805 806 if (ef->preloaded) { 807 if (ef->reltab) 808 free(ef->reltab, M_LINKER); 809 if (ef->relatab) 810 free(ef->relatab, M_LINKER); 811 if (ef->progtab) 812 free(ef->progtab, M_LINKER); 813 if (file->filename != NULL) 814 preload_delete_name(file->filename); 815 /* XXX reclaim module memory? */ 816 return; 817 } 818 819 for (i = 0; i < ef->nrel; i++) 820 if (ef->reltab[i].rel) 821 free(ef->reltab[i].rel, M_LINKER); 822 for (i = 0; i < ef->nrela; i++) 823 if (ef->relatab[i].rela) 824 free(ef->relatab[i].rela, M_LINKER); 825 if (ef->reltab) 826 free(ef->reltab, M_LINKER); 827 if (ef->relatab) 828 free(ef->relatab, M_LINKER); 829 if (ef->progtab) 830 free(ef->progtab, M_LINKER); 831 832 if (ef->object) { 833 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 834 (vm_offset_t) ef->address + 835 (ef->object->size << PAGE_SHIFT)); 836 } 837 if (ef->e_shdr) 838 free(ef->e_shdr, M_LINKER); 839 if (ef->ddbsymtab) 840 free(ef->ddbsymtab, M_LINKER); 841 if (ef->ddbstrtab) 842 free(ef->ddbstrtab, M_LINKER); 843 if (ef->shstrtab) 844 free(ef->shstrtab, M_LINKER); 845 } 846 847 static const char * 848 symbol_name(elf_file_t ef, Elf_Size r_info) 849 { 850 const Elf_Sym *ref; 851 852 if (ELF_R_SYM(r_info)) { 853 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 854 return ef->ddbstrtab + ref->st_name; 855 } else 856 return NULL; 857 } 858 859 static Elf_Addr 860 findbase(elf_file_t ef, int sec) 861 { 862 int i; 863 Elf_Addr base = 0; 864 865 for (i = 0; i < ef->nprogtab; i++) { 866 if (sec == ef->progtab[i].sec) { 867 base = (Elf_Addr)ef->progtab[i].addr; 868 break; 869 } 870 } 871 return base; 872 } 873 874 static int 875 relocate_file(elf_file_t ef) 876 { 877 const Elf_Rel *rellim; 878 const Elf_Rel *rel; 879 const Elf_Rela *relalim; 880 const Elf_Rela *rela; 881 const char *symname; 882 const Elf_Sym *sym; 883 int i; 884 Elf_Size symidx; 885 Elf_Addr base; 886 887 888 /* Perform relocations without addend if there are any: */ 889 for (i = 0; i < ef->nrel; i++) { 890 rel = ef->reltab[i].rel; 891 if (rel == NULL) 892 panic("lost a reltab!"); 893 rellim = rel + ef->reltab[i].nrel; 894 base = findbase(ef, ef->reltab[i].sec); 895 if (base == 0) 896 panic("lost base for reltab"); 897 for ( ; rel < rellim; rel++) { 898 symidx = ELF_R_SYM(rel->r_info); 899 if (symidx >= ef->ddbsymcnt) 900 continue; 901 sym = ef->ddbsymtab + symidx; 902 /* Local relocs are already done */ 903 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 904 continue; 905 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 906 elf_obj_lookup)) { 907 symname = symbol_name(ef, rel->r_info); 908 printf("link_elf_obj: symbol %s undefined\n", 909 symname); 910 return ENOENT; 911 } 912 } 913 } 914 915 /* Perform relocations with addend if there are any: */ 916 for (i = 0; i < ef->nrela; i++) { 917 rela = ef->relatab[i].rela; 918 if (rela == NULL) 919 panic("lost a relatab!"); 920 relalim = rela + ef->relatab[i].nrela; 921 base = findbase(ef, ef->relatab[i].sec); 922 if (base == 0) 923 panic("lost base for relatab"); 924 for ( ; rela < relalim; rela++) { 925 symidx = ELF_R_SYM(rela->r_info); 926 if (symidx >= ef->ddbsymcnt) 927 continue; 928 sym = ef->ddbsymtab + symidx; 929 /* Local relocs are already done */ 930 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 931 continue; 932 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 933 elf_obj_lookup)) { 934 symname = symbol_name(ef, rela->r_info); 935 printf("link_elf_obj: symbol %s undefined\n", 936 symname); 937 return ENOENT; 938 } 939 } 940 } 941 942 return 0; 943 } 944 945 static int 946 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 947 { 948 elf_file_t ef = (elf_file_t) lf; 949 const Elf_Sym *symp; 950 const char *strp; 951 int i; 952 953 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 954 strp = ef->ddbstrtab + symp->st_name; 955 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 956 *sym = (c_linker_sym_t) symp; 957 return 0; 958 } 959 } 960 return ENOENT; 961 } 962 963 static int 964 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 965 linker_symval_t *symval) 966 { 967 elf_file_t ef = (elf_file_t) lf; 968 const Elf_Sym *es = (const Elf_Sym*) sym; 969 970 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 971 symval->name = ef->ddbstrtab + es->st_name; 972 symval->value = (caddr_t)es->st_value; 973 symval->size = es->st_size; 974 return 0; 975 } 976 return ENOENT; 977 } 978 979 static int 980 link_elf_search_symbol(linker_file_t lf, caddr_t value, 981 c_linker_sym_t *sym, long *diffp) 982 { 983 elf_file_t ef = (elf_file_t) lf; 984 u_long off = (uintptr_t) (void *) value; 985 u_long diff = off; 986 u_long st_value; 987 const Elf_Sym *es; 988 const Elf_Sym *best = 0; 989 int i; 990 991 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 992 if (es->st_name == 0) 993 continue; 994 st_value = es->st_value; 995 if (off >= st_value) { 996 if (off - st_value < diff) { 997 diff = off - st_value; 998 best = es; 999 if (diff == 0) 1000 break; 1001 } else if (off - st_value == diff) { 1002 best = es; 1003 } 1004 } 1005 } 1006 if (best == 0) 1007 *diffp = off; 1008 else 1009 *diffp = diff; 1010 *sym = (c_linker_sym_t) best; 1011 1012 return 0; 1013 } 1014 1015 /* 1016 * Look up a linker set on an ELF system. 1017 */ 1018 static int 1019 link_elf_lookup_set(linker_file_t lf, const char *name, 1020 void ***startp, void ***stopp, int *countp) 1021 { 1022 elf_file_t ef = (elf_file_t)lf; 1023 void **start, **stop; 1024 int i, count; 1025 1026 /* Relative to section number */ 1027 for (i = 0; i < ef->nprogtab; i++) { 1028 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1029 strcmp(ef->progtab[i].name + 4, name) == 0) { 1030 start = (void **)ef->progtab[i].addr; 1031 stop = (void **)((char *)ef->progtab[i].addr + 1032 ef->progtab[i].size); 1033 count = stop - start; 1034 if (startp) 1035 *startp = start; 1036 if (stopp) 1037 *stopp = stop; 1038 if (countp) 1039 *countp = count; 1040 return (0); 1041 } 1042 } 1043 return (ESRCH); 1044 } 1045 1046 static int 1047 link_elf_each_function_name(linker_file_t file, 1048 int (*callback)(const char *, void *), void *opaque) 1049 { 1050 elf_file_t ef = (elf_file_t)file; 1051 const Elf_Sym *symp; 1052 int i, error; 1053 1054 /* Exhaustive search */ 1055 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1056 if (symp->st_value != 0 && 1057 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1058 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1059 if (error) 1060 return (error); 1061 } 1062 } 1063 return (0); 1064 } 1065 1066 /* 1067 * Symbol lookup function that can be used when the symbol index is known (ie 1068 * in relocations). It uses the symbol index instead of doing a fully fledged 1069 * hash table based lookup when such is valid. For example for local symbols. 1070 * This is not only more efficient, it's also more correct. It's not always 1071 * the case that the symbol can be found through the hash table. 1072 */ 1073 static Elf_Addr 1074 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1075 { 1076 elf_file_t ef = (elf_file_t)lf; 1077 const Elf_Sym *sym; 1078 const char *symbol; 1079 Elf_Addr ret; 1080 1081 /* Don't even try to lookup the symbol if the index is bogus. */ 1082 if (symidx >= ef->ddbsymcnt) 1083 return (0); 1084 1085 sym = ef->ddbsymtab + symidx; 1086 1087 /* Quick answer if there is a definition included. */ 1088 if (sym->st_shndx != SHN_UNDEF) 1089 return (sym->st_value); 1090 1091 /* If we get here, then it is undefined and needs a lookup. */ 1092 switch (ELF_ST_BIND(sym->st_info)) { 1093 case STB_LOCAL: 1094 /* Local, but undefined? huh? */ 1095 return (0); 1096 1097 case STB_GLOBAL: 1098 /* Relative to Data or Function name */ 1099 symbol = ef->ddbstrtab + sym->st_name; 1100 1101 /* Force a lookup failure if the symbol name is bogus. */ 1102 if (*symbol == 0) 1103 return (0); 1104 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1105 return ret; 1106 1107 case STB_WEAK: 1108 printf("link_elf_obj: Weak symbols not supported\n"); 1109 return (0); 1110 1111 default: 1112 return (0); 1113 } 1114 } 1115 1116 static void 1117 link_elf_reloc_local(linker_file_t lf) 1118 { 1119 elf_file_t ef = (elf_file_t)lf; 1120 const Elf_Rel *rellim; 1121 const Elf_Rel *rel; 1122 const Elf_Rela *relalim; 1123 const Elf_Rela *rela; 1124 const Elf_Sym *sym; 1125 Elf_Addr base; 1126 int i; 1127 Elf_Size symidx; 1128 1129 /* Perform relocations without addend if there are any: */ 1130 for (i = 0; i < ef->nrel; i++) { 1131 rel = ef->reltab[i].rel; 1132 if (rel == NULL) 1133 panic("lost a reltab!"); 1134 rellim = rel + ef->reltab[i].nrel; 1135 base = findbase(ef, ef->reltab[i].sec); 1136 if (base == 0) 1137 panic("lost base for reltab"); 1138 for ( ; rel < rellim; rel++) { 1139 symidx = ELF_R_SYM(rel->r_info); 1140 if (symidx >= ef->ddbsymcnt) 1141 continue; 1142 sym = ef->ddbsymtab + symidx; 1143 /* Only do local relocs */ 1144 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1145 continue; 1146 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1147 elf_obj_lookup); 1148 } 1149 } 1150 1151 /* Perform relocations with addend if there are any: */ 1152 for (i = 0; i < ef->nrela; i++) { 1153 rela = ef->relatab[i].rela; 1154 if (rela == NULL) 1155 panic("lost a relatab!"); 1156 relalim = rela + ef->relatab[i].nrela; 1157 base = findbase(ef, ef->relatab[i].sec); 1158 if (base == 0) 1159 panic("lost base for relatab"); 1160 for ( ; rela < relalim; rela++) { 1161 symidx = ELF_R_SYM(rela->r_info); 1162 if (symidx >= ef->ddbsymcnt) 1163 continue; 1164 sym = ef->ddbsymtab + symidx; 1165 /* Only do local relocs */ 1166 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1167 continue; 1168 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1169 elf_obj_lookup); 1170 } 1171 } 1172 } 1173