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/malloc.h> 39 #include <sys/mutex.h> 40 #include <sys/mount.h> 41 #include <sys/proc.h> 42 #include <sys/namei.h> 43 #include <sys/fcntl.h> 44 #include <sys/vnode.h> 45 #include <sys/linker.h> 46 47 #include <machine/elf.h> 48 49 #include <security/mac/mac_framework.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_param.h> 53 #include <vm/vm_object.h> 54 #include <vm/vm_kern.h> 55 #include <vm/vm_extern.h> 56 #include <vm/pmap.h> 57 #include <vm/vm_map.h> 58 59 #include <sys/link_elf.h> 60 61 #ifdef DDB_CTF 62 #include <net/zlib.h> 63 #endif 64 65 #include "linker_if.h" 66 67 typedef struct { 68 void *addr; 69 Elf_Off size; 70 int flags; 71 int sec; /* Original section */ 72 char *name; 73 } Elf_progent; 74 75 typedef struct { 76 Elf_Rel *rel; 77 int nrel; 78 int sec; 79 } Elf_relent; 80 81 typedef struct { 82 Elf_Rela *rela; 83 int nrela; 84 int sec; 85 } Elf_relaent; 86 87 88 typedef struct elf_file { 89 struct linker_file lf; /* Common fields */ 90 91 int preloaded; 92 caddr_t address; /* Relocation address */ 93 vm_object_t object; /* VM object to hold file pages */ 94 Elf_Shdr *e_shdr; 95 96 Elf_progent *progtab; 97 int nprogtab; 98 99 Elf_relaent *relatab; 100 int nrelatab; 101 102 Elf_relent *reltab; 103 int nreltab; 104 105 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 106 long ddbsymcnt; /* Number of symbols */ 107 caddr_t ddbstrtab; /* String table */ 108 long ddbstrcnt; /* number of bytes in string table */ 109 110 caddr_t shstrtab; /* Section name string table */ 111 long shstrcnt; /* number of bytes in string table */ 112 113 caddr_t ctftab; /* CTF table */ 114 long ctfcnt; /* number of bytes in CTF table */ 115 caddr_t ctfoff; /* CTF offset table */ 116 caddr_t typoff; /* Type offset table */ 117 long typlen; /* Number of type entries. */ 118 119 } *elf_file_t; 120 121 #include <kern/kern_ctf.c> 122 123 static int link_elf_link_preload(linker_class_t cls, 124 const char *, linker_file_t *); 125 static int link_elf_link_preload_finish(linker_file_t); 126 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); 127 static int link_elf_lookup_symbol(linker_file_t, const char *, 128 c_linker_sym_t *); 129 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 130 linker_symval_t *); 131 static int link_elf_search_symbol(linker_file_t, caddr_t value, 132 c_linker_sym_t *sym, long *diffp); 133 134 static void link_elf_unload_file(linker_file_t); 135 static int link_elf_lookup_set(linker_file_t, const char *, 136 void ***, void ***, int *); 137 static int link_elf_each_function_name(linker_file_t, 138 int (*)(const char *, void *), void *); 139 static int link_elf_each_function_nameval(linker_file_t, 140 linker_function_nameval_callback_t, 141 void *); 142 static void link_elf_reloc_local(linker_file_t); 143 144 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps); 145 146 static kobj_method_t link_elf_methods[] = { 147 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 148 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 149 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 150 KOBJMETHOD(linker_unload, link_elf_unload_file), 151 KOBJMETHOD(linker_load_file, link_elf_load_file), 152 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 153 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 154 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 155 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 156 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 157 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 158 { 0, 0 } 159 }; 160 161 static struct linker_class link_elf_class = { 162 #if ELF_TARG_CLASS == ELFCLASS32 163 "elf32_obj", 164 #else 165 "elf64_obj", 166 #endif 167 link_elf_methods, sizeof(struct elf_file) 168 }; 169 170 static int relocate_file(elf_file_t ef); 171 172 static void 173 link_elf_error(const char *filename, const char *s) 174 { 175 if (filename == NULL) 176 printf("kldload: %s\n", s); 177 else 178 printf("kldload: %s: %s\n", filename, s); 179 } 180 181 static void 182 link_elf_init(void *arg) 183 { 184 185 linker_add_class(&link_elf_class); 186 } 187 188 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0); 189 190 static int 191 link_elf_link_preload(linker_class_t cls, const char *filename, 192 linker_file_t *result) 193 { 194 Elf_Ehdr *hdr; 195 Elf_Shdr *shdr; 196 Elf_Sym *es; 197 void *modptr, *baseptr, *sizeptr; 198 char *type; 199 elf_file_t ef; 200 linker_file_t lf; 201 Elf_Addr off; 202 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 203 204 /* Look to see if we have the file preloaded */ 205 modptr = preload_search_by_name(filename); 206 if (modptr == NULL) 207 return ENOENT; 208 209 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 210 baseptr = preload_search_info(modptr, MODINFO_ADDR); 211 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 212 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 213 MODINFOMD_ELFHDR); 214 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 215 MODINFOMD_SHDR); 216 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) 217 " obj module") != 0 && 218 strcmp(type, "elf obj module") != 0)) { 219 return (EFTYPE); 220 } 221 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 222 shdr == NULL) 223 return (EINVAL); 224 225 lf = linker_make_file(filename, &link_elf_class); 226 if (lf == NULL) 227 return (ENOMEM); 228 229 ef = (elf_file_t)lf; 230 ef->preloaded = 1; 231 ef->address = *(caddr_t *)baseptr; 232 lf->address = *(caddr_t *)baseptr; 233 lf->size = *(size_t *)sizeptr; 234 235 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 236 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 237 hdr->e_ident[EI_VERSION] != EV_CURRENT || 238 hdr->e_version != EV_CURRENT || 239 hdr->e_type != ET_REL || 240 hdr->e_machine != ELF_TARG_MACH) { 241 error = EFTYPE; 242 goto out; 243 } 244 ef->e_shdr = shdr; 245 246 /* Scan the section header for information and table sizing. */ 247 symtabindex = -1; 248 symstrindex = -1; 249 for (i = 0; i < hdr->e_shnum; i++) { 250 switch (shdr[i].sh_type) { 251 case SHT_PROGBITS: 252 case SHT_NOBITS: 253 ef->nprogtab++; 254 break; 255 case SHT_SYMTAB: 256 symtabindex = i; 257 symstrindex = shdr[i].sh_link; 258 break; 259 case SHT_REL: 260 ef->nreltab++; 261 break; 262 case SHT_RELA: 263 ef->nrelatab++; 264 break; 265 } 266 } 267 268 shstrindex = hdr->e_shstrndx; 269 if (ef->nprogtab == 0 || symstrindex < 0 || 270 symstrindex >= hdr->e_shnum || 271 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 272 shstrindex >= hdr->e_shnum || 273 shdr[shstrindex].sh_type != SHT_STRTAB) { 274 printf("%s: bad/missing section headers\n", filename); 275 error = ENOEXEC; 276 goto out; 277 } 278 279 /* Allocate space for tracking the load chunks */ 280 if (ef->nprogtab != 0) 281 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 282 M_LINKER, M_WAITOK | M_ZERO); 283 if (ef->nreltab != 0) 284 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 285 M_LINKER, M_WAITOK | M_ZERO); 286 if (ef->nrelatab != 0) 287 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 288 M_LINKER, M_WAITOK | M_ZERO); 289 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 290 (ef->nreltab != 0 && ef->reltab == NULL) || 291 (ef->nrelatab != 0 && ef->relatab == NULL)) { 292 error = ENOMEM; 293 goto out; 294 } 295 296 /* XXX, relocate the sh_addr fields saved by the loader. */ 297 off = 0; 298 for (i = 0; i < hdr->e_shnum; i++) { 299 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 300 off = shdr[i].sh_addr; 301 } 302 for (i = 0; i < hdr->e_shnum; i++) { 303 if (shdr[i].sh_addr != 0) 304 shdr[i].sh_addr = shdr[i].sh_addr - off + 305 (Elf_Addr)ef->address; 306 } 307 308 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 309 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 310 ef->ddbstrcnt = shdr[symstrindex].sh_size; 311 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 312 ef->shstrcnt = shdr[shstrindex].sh_size; 313 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 314 315 /* Now fill out progtab and the relocation tables. */ 316 pb = 0; 317 rl = 0; 318 ra = 0; 319 for (i = 0; i < hdr->e_shnum; i++) { 320 switch (shdr[i].sh_type) { 321 case SHT_PROGBITS: 322 case SHT_NOBITS: 323 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 324 if (shdr[i].sh_type == SHT_PROGBITS) 325 ef->progtab[pb].name = "<<PROGBITS>>"; 326 else 327 ef->progtab[pb].name = "<<NOBITS>>"; 328 ef->progtab[pb].size = shdr[i].sh_size; 329 ef->progtab[pb].sec = i; 330 if (ef->shstrtab && shdr[i].sh_name != 0) 331 ef->progtab[pb].name = 332 ef->shstrtab + shdr[i].sh_name; 333 334 /* Update all symbol values with the offset. */ 335 for (j = 0; j < ef->ddbsymcnt; j++) { 336 es = &ef->ddbsymtab[j]; 337 if (es->st_shndx != i) 338 continue; 339 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 340 } 341 pb++; 342 break; 343 case SHT_REL: 344 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 345 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 346 ef->reltab[rl].sec = shdr[i].sh_info; 347 rl++; 348 break; 349 case SHT_RELA: 350 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 351 ef->relatab[ra].nrela = 352 shdr[i].sh_size / sizeof(Elf_Rela); 353 ef->relatab[ra].sec = shdr[i].sh_info; 354 ra++; 355 break; 356 } 357 } 358 if (pb != ef->nprogtab) 359 panic("lost progbits"); 360 if (rl != ef->nreltab) 361 panic("lost reltab"); 362 if (ra != ef->nrelatab) 363 panic("lost relatab"); 364 365 /* Local intra-module relocations */ 366 link_elf_reloc_local(lf); 367 368 *result = lf; 369 return (0); 370 371 out: 372 /* preload not done this way */ 373 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 374 return (error); 375 } 376 377 static int 378 link_elf_link_preload_finish(linker_file_t lf) 379 { 380 elf_file_t ef; 381 int error; 382 383 ef = (elf_file_t)lf; 384 error = relocate_file(ef); 385 if (error) 386 return error; 387 388 /* Notify MD code that a module is being loaded. */ 389 error = elf_cpu_load_file(lf); 390 if (error) 391 return (error); 392 393 return (0); 394 } 395 396 static int 397 link_elf_load_file(linker_class_t cls, const char *filename, 398 linker_file_t *result) 399 { 400 struct nameidata nd; 401 struct thread *td = curthread; /* XXX */ 402 Elf_Ehdr *hdr; 403 Elf_Shdr *shdr; 404 Elf_Sym *es; 405 int nbytes, i, j; 406 vm_offset_t mapbase; 407 size_t mapsize; 408 int error = 0; 409 int resid, flags; 410 elf_file_t ef; 411 linker_file_t lf; 412 int symtabindex; 413 int symstrindex; 414 int shstrindex; 415 int nsym; 416 int pb, rl, ra; 417 int alignmask; 418 int vfslocked; 419 420 shdr = NULL; 421 lf = NULL; 422 mapsize = 0; 423 hdr = NULL; 424 425 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td); 426 flags = FREAD; 427 error = vn_open(&nd, &flags, 0, NULL); 428 if (error) 429 return error; 430 vfslocked = NDHASGIANT(&nd); 431 NDFREE(&nd, NDF_ONLY_PNBUF); 432 if (nd.ni_vp->v_type != VREG) { 433 error = ENOEXEC; 434 goto out; 435 } 436 #ifdef MAC 437 error = mac_kld_check_load(td->td_ucred, nd.ni_vp); 438 if (error) { 439 goto out; 440 } 441 #endif 442 443 /* Read the elf header from the file. */ 444 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 445 if (hdr == NULL) { 446 error = ENOMEM; 447 goto out; 448 } 449 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0, 450 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 451 &resid, td); 452 if (error) 453 goto out; 454 if (resid != 0){ 455 error = ENOEXEC; 456 goto out; 457 } 458 459 if (!IS_ELF(*hdr)) { 460 error = ENOEXEC; 461 goto out; 462 } 463 464 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 465 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 466 link_elf_error(filename, "Unsupported file layout"); 467 error = ENOEXEC; 468 goto out; 469 } 470 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 471 || hdr->e_version != EV_CURRENT) { 472 link_elf_error(filename, "Unsupported file version"); 473 error = ENOEXEC; 474 goto out; 475 } 476 if (hdr->e_type != ET_REL) { 477 link_elf_error(filename, "Unsupported file type"); 478 error = ENOEXEC; 479 goto out; 480 } 481 if (hdr->e_machine != ELF_TARG_MACH) { 482 link_elf_error(filename, "Unsupported machine"); 483 error = ENOEXEC; 484 goto out; 485 } 486 487 lf = linker_make_file(filename, &link_elf_class); 488 if (!lf) { 489 error = ENOMEM; 490 goto out; 491 } 492 ef = (elf_file_t) lf; 493 ef->nprogtab = 0; 494 ef->e_shdr = 0; 495 ef->nreltab = 0; 496 ef->nrelatab = 0; 497 498 /* Allocate and read in the section header */ 499 nbytes = hdr->e_shnum * hdr->e_shentsize; 500 if (nbytes == 0 || hdr->e_shoff == 0 || 501 hdr->e_shentsize != sizeof(Elf_Shdr)) { 502 error = ENOEXEC; 503 goto out; 504 } 505 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 506 if (shdr == NULL) { 507 error = ENOMEM; 508 goto out; 509 } 510 ef->e_shdr = shdr; 511 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff, 512 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); 513 if (error) 514 goto out; 515 if (resid) { 516 error = ENOEXEC; 517 goto out; 518 } 519 520 /* Scan the section header for information and table sizing. */ 521 nsym = 0; 522 symtabindex = -1; 523 symstrindex = -1; 524 for (i = 0; i < hdr->e_shnum; i++) { 525 switch (shdr[i].sh_type) { 526 case SHT_PROGBITS: 527 case SHT_NOBITS: 528 ef->nprogtab++; 529 break; 530 case SHT_SYMTAB: 531 nsym++; 532 symtabindex = i; 533 symstrindex = shdr[i].sh_link; 534 break; 535 case SHT_REL: 536 ef->nreltab++; 537 break; 538 case SHT_RELA: 539 ef->nrelatab++; 540 break; 541 case SHT_STRTAB: 542 break; 543 } 544 } 545 if (ef->nprogtab == 0) { 546 link_elf_error(filename, "file has no contents"); 547 error = ENOEXEC; 548 goto out; 549 } 550 if (nsym != 1) { 551 /* Only allow one symbol table for now */ 552 link_elf_error(filename, "file has no valid symbol table"); 553 error = ENOEXEC; 554 goto out; 555 } 556 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 557 shdr[symstrindex].sh_type != SHT_STRTAB) { 558 link_elf_error(filename, "file has invalid symbol strings"); 559 error = ENOEXEC; 560 goto out; 561 } 562 563 /* Allocate space for tracking the load chunks */ 564 if (ef->nprogtab != 0) 565 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 566 M_LINKER, M_WAITOK | M_ZERO); 567 if (ef->nreltab != 0) 568 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 569 M_LINKER, M_WAITOK | M_ZERO); 570 if (ef->nrelatab != 0) 571 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 572 M_LINKER, M_WAITOK | M_ZERO); 573 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 574 (ef->nreltab != 0 && ef->reltab == NULL) || 575 (ef->nrelatab != 0 && ef->relatab == NULL)) { 576 error = ENOMEM; 577 goto out; 578 } 579 580 if (symtabindex == -1) 581 panic("lost symbol table index"); 582 /* Allocate space for and load the symbol table */ 583 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 584 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 585 if (ef->ddbsymtab == NULL) { 586 error = ENOMEM; 587 goto out; 588 } 589 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab, 590 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 591 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 592 &resid, td); 593 if (error) 594 goto out; 595 if (resid != 0){ 596 error = EINVAL; 597 goto out; 598 } 599 600 if (symstrindex == -1) 601 panic("lost symbol string index"); 602 /* Allocate space for and load the symbol strings */ 603 ef->ddbstrcnt = shdr[symstrindex].sh_size; 604 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 605 if (ef->ddbstrtab == NULL) { 606 error = ENOMEM; 607 goto out; 608 } 609 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab, 610 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 611 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 612 &resid, td); 613 if (error) 614 goto out; 615 if (resid != 0){ 616 error = EINVAL; 617 goto out; 618 } 619 620 /* Do we have a string table for the section names? */ 621 shstrindex = -1; 622 if (hdr->e_shstrndx != 0 && 623 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 624 shstrindex = hdr->e_shstrndx; 625 ef->shstrcnt = shdr[shstrindex].sh_size; 626 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 627 M_WAITOK); 628 if (ef->shstrtab == NULL) { 629 error = ENOMEM; 630 goto out; 631 } 632 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab, 633 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 634 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 635 &resid, td); 636 if (error) 637 goto out; 638 if (resid != 0){ 639 error = EINVAL; 640 goto out; 641 } 642 } 643 644 /* Size up code/data(progbits) and bss(nobits). */ 645 alignmask = 0; 646 for (i = 0; i < hdr->e_shnum; i++) { 647 switch (shdr[i].sh_type) { 648 case SHT_PROGBITS: 649 case SHT_NOBITS: 650 alignmask = shdr[i].sh_addralign - 1; 651 mapsize += alignmask; 652 mapsize &= ~alignmask; 653 mapsize += shdr[i].sh_size; 654 break; 655 } 656 } 657 658 /* 659 * We know how much space we need for the text/data/bss/etc. 660 * This stuff needs to be in a single chunk so that profiling etc 661 * can get the bounds and gdb can associate offsets with modules 662 */ 663 ef->object = vm_object_allocate(OBJT_DEFAULT, 664 round_page(mapsize) >> PAGE_SHIFT); 665 if (ef->object == NULL) { 666 error = ENOMEM; 667 goto out; 668 } 669 ef->address = (caddr_t) vm_map_min(kernel_map); 670 671 /* 672 * In order to satisfy amd64's architectural requirements on the 673 * location of code and data in the kernel's address space, request a 674 * mapping that is above the kernel. 675 */ 676 mapbase = KERNBASE; 677 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 678 round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE); 679 if (error) { 680 vm_object_deallocate(ef->object); 681 ef->object = 0; 682 goto out; 683 } 684 685 /* Wire the pages */ 686 error = vm_map_wire(kernel_map, mapbase, 687 mapbase + round_page(mapsize), 688 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 689 if (error != KERN_SUCCESS) { 690 error = ENOMEM; 691 goto out; 692 } 693 694 /* Inform the kld system about the situation */ 695 lf->address = ef->address = (caddr_t)mapbase; 696 lf->size = mapsize; 697 698 /* 699 * Now load code/data(progbits), zero bss(nobits), allocate space for 700 * and load relocs 701 */ 702 pb = 0; 703 rl = 0; 704 ra = 0; 705 alignmask = 0; 706 for (i = 0; i < hdr->e_shnum; i++) { 707 switch (shdr[i].sh_type) { 708 case SHT_PROGBITS: 709 case SHT_NOBITS: 710 alignmask = shdr[i].sh_addralign - 1; 711 mapbase += alignmask; 712 mapbase &= ~alignmask; 713 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase; 714 if (shdr[i].sh_type == SHT_PROGBITS) { 715 ef->progtab[pb].name = "<<PROGBITS>>"; 716 error = vn_rdwr(UIO_READ, nd.ni_vp, 717 ef->progtab[pb].addr, 718 shdr[i].sh_size, shdr[i].sh_offset, 719 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 720 NOCRED, &resid, td); 721 if (error) 722 goto out; 723 if (resid != 0){ 724 error = EINVAL; 725 goto out; 726 } 727 } else { 728 ef->progtab[pb].name = "<<NOBITS>>"; 729 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 730 } 731 ef->progtab[pb].size = shdr[i].sh_size; 732 ef->progtab[pb].sec = i; 733 if (ef->shstrtab && shdr[i].sh_name != 0) 734 ef->progtab[pb].name = 735 ef->shstrtab + shdr[i].sh_name; 736 737 /* Update all symbol values with the offset. */ 738 for (j = 0; j < ef->ddbsymcnt; j++) { 739 es = &ef->ddbsymtab[j]; 740 if (es->st_shndx != i) 741 continue; 742 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 743 } 744 mapbase += shdr[i].sh_size; 745 pb++; 746 break; 747 case SHT_REL: 748 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 749 M_WAITOK); 750 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 751 ef->reltab[rl].sec = shdr[i].sh_info; 752 error = vn_rdwr(UIO_READ, nd.ni_vp, 753 (void *)ef->reltab[rl].rel, 754 shdr[i].sh_size, shdr[i].sh_offset, 755 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 756 &resid, td); 757 if (error) 758 goto out; 759 if (resid != 0){ 760 error = EINVAL; 761 goto out; 762 } 763 rl++; 764 break; 765 case SHT_RELA: 766 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 767 M_WAITOK); 768 ef->relatab[ra].nrela = 769 shdr[i].sh_size / sizeof(Elf_Rela); 770 ef->relatab[ra].sec = shdr[i].sh_info; 771 error = vn_rdwr(UIO_READ, nd.ni_vp, 772 (void *)ef->relatab[ra].rela, 773 shdr[i].sh_size, shdr[i].sh_offset, 774 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 775 &resid, td); 776 if (error) 777 goto out; 778 if (resid != 0){ 779 error = EINVAL; 780 goto out; 781 } 782 ra++; 783 break; 784 } 785 } 786 if (pb != ef->nprogtab) 787 panic("lost progbits"); 788 if (rl != ef->nreltab) 789 panic("lost reltab"); 790 if (ra != ef->nrelatab) 791 panic("lost relatab"); 792 if (mapbase != (vm_offset_t)ef->address + mapsize) 793 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 794 mapbase, ef->address, mapsize, 795 (vm_offset_t)ef->address + mapsize); 796 797 /* Local intra-module relocations */ 798 link_elf_reloc_local(lf); 799 800 /* Pull in dependencies */ 801 VOP_UNLOCK(nd.ni_vp, 0); 802 error = linker_load_dependencies(lf); 803 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 804 if (error) 805 goto out; 806 807 /* External relocations */ 808 error = relocate_file(ef); 809 if (error) 810 goto out; 811 812 /* Notify MD code that a module is being loaded. */ 813 error = elf_cpu_load_file(lf); 814 if (error) 815 goto out; 816 817 *result = lf; 818 819 out: 820 if (error && lf) 821 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 822 if (hdr) 823 free(hdr, M_LINKER); 824 VOP_UNLOCK(nd.ni_vp, 0); 825 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 826 VFS_UNLOCK_GIANT(vfslocked); 827 828 return error; 829 } 830 831 static void 832 link_elf_unload_file(linker_file_t file) 833 { 834 elf_file_t ef = (elf_file_t) file; 835 int i; 836 837 /* Notify MD code that a module is being unloaded. */ 838 elf_cpu_unload_file(file); 839 840 if (ef->preloaded) { 841 if (ef->reltab) 842 free(ef->reltab, M_LINKER); 843 if (ef->relatab) 844 free(ef->relatab, M_LINKER); 845 if (ef->progtab) 846 free(ef->progtab, M_LINKER); 847 if (ef->ctftab) 848 free(ef->ctftab, M_LINKER); 849 if (ef->ctfoff) 850 free(ef->ctfoff, M_LINKER); 851 if (ef->typoff) 852 free(ef->typoff, M_LINKER); 853 if (file->filename != NULL) 854 preload_delete_name(file->filename); 855 /* XXX reclaim module memory? */ 856 return; 857 } 858 859 for (i = 0; i < ef->nreltab; i++) 860 if (ef->reltab[i].rel) 861 free(ef->reltab[i].rel, M_LINKER); 862 for (i = 0; i < ef->nrelatab; i++) 863 if (ef->relatab[i].rela) 864 free(ef->relatab[i].rela, M_LINKER); 865 if (ef->reltab) 866 free(ef->reltab, M_LINKER); 867 if (ef->relatab) 868 free(ef->relatab, M_LINKER); 869 if (ef->progtab) 870 free(ef->progtab, M_LINKER); 871 872 if (ef->object) { 873 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 874 (vm_offset_t) ef->address + 875 (ef->object->size << PAGE_SHIFT)); 876 } 877 if (ef->e_shdr) 878 free(ef->e_shdr, M_LINKER); 879 if (ef->ddbsymtab) 880 free(ef->ddbsymtab, M_LINKER); 881 if (ef->ddbstrtab) 882 free(ef->ddbstrtab, M_LINKER); 883 if (ef->shstrtab) 884 free(ef->shstrtab, M_LINKER); 885 if (ef->ctftab) 886 free(ef->ctftab, M_LINKER); 887 if (ef->ctfoff) 888 free(ef->ctfoff, M_LINKER); 889 if (ef->typoff) 890 free(ef->typoff, M_LINKER); 891 } 892 893 static const char * 894 symbol_name(elf_file_t ef, Elf_Size r_info) 895 { 896 const Elf_Sym *ref; 897 898 if (ELF_R_SYM(r_info)) { 899 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 900 return ef->ddbstrtab + ref->st_name; 901 } else 902 return NULL; 903 } 904 905 static Elf_Addr 906 findbase(elf_file_t ef, int sec) 907 { 908 int i; 909 Elf_Addr base = 0; 910 911 for (i = 0; i < ef->nprogtab; i++) { 912 if (sec == ef->progtab[i].sec) { 913 base = (Elf_Addr)ef->progtab[i].addr; 914 break; 915 } 916 } 917 return base; 918 } 919 920 static int 921 relocate_file(elf_file_t ef) 922 { 923 const Elf_Rel *rellim; 924 const Elf_Rel *rel; 925 const Elf_Rela *relalim; 926 const Elf_Rela *rela; 927 const char *symname; 928 const Elf_Sym *sym; 929 int i; 930 Elf_Size symidx; 931 Elf_Addr base; 932 933 934 /* Perform relocations without addend if there are any: */ 935 for (i = 0; i < ef->nreltab; i++) { 936 rel = ef->reltab[i].rel; 937 if (rel == NULL) 938 panic("lost a reltab!"); 939 rellim = rel + ef->reltab[i].nrel; 940 base = findbase(ef, ef->reltab[i].sec); 941 if (base == 0) 942 panic("lost base for reltab"); 943 for ( ; rel < rellim; rel++) { 944 symidx = ELF_R_SYM(rel->r_info); 945 if (symidx >= ef->ddbsymcnt) 946 continue; 947 sym = ef->ddbsymtab + symidx; 948 /* Local relocs are already done */ 949 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 950 continue; 951 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 952 elf_obj_lookup)) { 953 symname = symbol_name(ef, rel->r_info); 954 printf("link_elf_obj: symbol %s undefined\n", 955 symname); 956 return ENOENT; 957 } 958 } 959 } 960 961 /* Perform relocations with addend if there are any: */ 962 for (i = 0; i < ef->nrelatab; i++) { 963 rela = ef->relatab[i].rela; 964 if (rela == NULL) 965 panic("lost a relatab!"); 966 relalim = rela + ef->relatab[i].nrela; 967 base = findbase(ef, ef->relatab[i].sec); 968 if (base == 0) 969 panic("lost base for relatab"); 970 for ( ; rela < relalim; rela++) { 971 symidx = ELF_R_SYM(rela->r_info); 972 if (symidx >= ef->ddbsymcnt) 973 continue; 974 sym = ef->ddbsymtab + symidx; 975 /* Local relocs are already done */ 976 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 977 continue; 978 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 979 elf_obj_lookup)) { 980 symname = symbol_name(ef, rela->r_info); 981 printf("link_elf_obj: symbol %s undefined\n", 982 symname); 983 return ENOENT; 984 } 985 } 986 } 987 988 return 0; 989 } 990 991 static int 992 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 993 { 994 elf_file_t ef = (elf_file_t) lf; 995 const Elf_Sym *symp; 996 const char *strp; 997 int i; 998 999 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1000 strp = ef->ddbstrtab + symp->st_name; 1001 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1002 *sym = (c_linker_sym_t) symp; 1003 return 0; 1004 } 1005 } 1006 return ENOENT; 1007 } 1008 1009 static int 1010 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1011 linker_symval_t *symval) 1012 { 1013 elf_file_t ef = (elf_file_t) lf; 1014 const Elf_Sym *es = (const Elf_Sym*) sym; 1015 1016 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1017 symval->name = ef->ddbstrtab + es->st_name; 1018 symval->value = (caddr_t)es->st_value; 1019 symval->size = es->st_size; 1020 return 0; 1021 } 1022 return ENOENT; 1023 } 1024 1025 static int 1026 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1027 c_linker_sym_t *sym, long *diffp) 1028 { 1029 elf_file_t ef = (elf_file_t) lf; 1030 u_long off = (uintptr_t) (void *) value; 1031 u_long diff = off; 1032 u_long st_value; 1033 const Elf_Sym *es; 1034 const Elf_Sym *best = 0; 1035 int i; 1036 1037 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1038 if (es->st_name == 0) 1039 continue; 1040 st_value = es->st_value; 1041 if (off >= st_value) { 1042 if (off - st_value < diff) { 1043 diff = off - st_value; 1044 best = es; 1045 if (diff == 0) 1046 break; 1047 } else if (off - st_value == diff) { 1048 best = es; 1049 } 1050 } 1051 } 1052 if (best == 0) 1053 *diffp = off; 1054 else 1055 *diffp = diff; 1056 *sym = (c_linker_sym_t) best; 1057 1058 return 0; 1059 } 1060 1061 /* 1062 * Look up a linker set on an ELF system. 1063 */ 1064 static int 1065 link_elf_lookup_set(linker_file_t lf, const char *name, 1066 void ***startp, void ***stopp, int *countp) 1067 { 1068 elf_file_t ef = (elf_file_t)lf; 1069 void **start, **stop; 1070 int i, count; 1071 1072 /* Relative to section number */ 1073 for (i = 0; i < ef->nprogtab; i++) { 1074 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1075 strcmp(ef->progtab[i].name + 4, name) == 0) { 1076 start = (void **)ef->progtab[i].addr; 1077 stop = (void **)((char *)ef->progtab[i].addr + 1078 ef->progtab[i].size); 1079 count = stop - start; 1080 if (startp) 1081 *startp = start; 1082 if (stopp) 1083 *stopp = stop; 1084 if (countp) 1085 *countp = count; 1086 return (0); 1087 } 1088 } 1089 return (ESRCH); 1090 } 1091 1092 static int 1093 link_elf_each_function_name(linker_file_t file, 1094 int (*callback)(const char *, void *), void *opaque) 1095 { 1096 elf_file_t ef = (elf_file_t)file; 1097 const Elf_Sym *symp; 1098 int i, error; 1099 1100 /* Exhaustive search */ 1101 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1102 if (symp->st_value != 0 && 1103 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1104 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1105 if (error) 1106 return (error); 1107 } 1108 } 1109 return (0); 1110 } 1111 1112 static int 1113 link_elf_each_function_nameval(linker_file_t file, 1114 linker_function_nameval_callback_t callback, void *opaque) 1115 { 1116 linker_symval_t symval; 1117 elf_file_t ef = (elf_file_t)file; 1118 const Elf_Sym* symp; 1119 int i, error; 1120 1121 /* Exhaustive search */ 1122 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1123 if (symp->st_value != 0 && 1124 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1125 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1126 if (error) 1127 return (error); 1128 error = callback(file, i, &symval, opaque); 1129 if (error) 1130 return (error); 1131 } 1132 } 1133 return (0); 1134 } 1135 1136 /* 1137 * Symbol lookup function that can be used when the symbol index is known (ie 1138 * in relocations). It uses the symbol index instead of doing a fully fledged 1139 * hash table based lookup when such is valid. For example for local symbols. 1140 * This is not only more efficient, it's also more correct. It's not always 1141 * the case that the symbol can be found through the hash table. 1142 */ 1143 static Elf_Addr 1144 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1145 { 1146 elf_file_t ef = (elf_file_t)lf; 1147 const Elf_Sym *sym; 1148 const char *symbol; 1149 Elf_Addr ret; 1150 1151 /* Don't even try to lookup the symbol if the index is bogus. */ 1152 if (symidx >= ef->ddbsymcnt) 1153 return (0); 1154 1155 sym = ef->ddbsymtab + symidx; 1156 1157 /* Quick answer if there is a definition included. */ 1158 if (sym->st_shndx != SHN_UNDEF) 1159 return (sym->st_value); 1160 1161 /* If we get here, then it is undefined and needs a lookup. */ 1162 switch (ELF_ST_BIND(sym->st_info)) { 1163 case STB_LOCAL: 1164 /* Local, but undefined? huh? */ 1165 return (0); 1166 1167 case STB_GLOBAL: 1168 /* Relative to Data or Function name */ 1169 symbol = ef->ddbstrtab + sym->st_name; 1170 1171 /* Force a lookup failure if the symbol name is bogus. */ 1172 if (*symbol == 0) 1173 return (0); 1174 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1175 return ret; 1176 1177 case STB_WEAK: 1178 printf("link_elf_obj: Weak symbols not supported\n"); 1179 return (0); 1180 1181 default: 1182 return (0); 1183 } 1184 } 1185 1186 static void 1187 link_elf_fix_link_set(elf_file_t ef) 1188 { 1189 static const char startn[] = "__start_"; 1190 static const char stopn[] = "__stop_"; 1191 Elf_Sym *sym; 1192 const char *sym_name, *linkset_name; 1193 Elf_Addr startp, stopp; 1194 Elf_Size symidx; 1195 int start, i; 1196 1197 startp = stopp = 0; 1198 for (symidx = 1 /* zero entry is special */; 1199 symidx < ef->ddbsymcnt; symidx++) { 1200 sym = ef->ddbsymtab + symidx; 1201 if (sym->st_shndx != SHN_UNDEF) 1202 continue; 1203 1204 sym_name = ef->ddbstrtab + sym->st_name; 1205 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1206 start = 1; 1207 linkset_name = sym_name + sizeof(startn) - 1; 1208 } 1209 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1210 start = 0; 1211 linkset_name = sym_name + sizeof(stopn) - 1; 1212 } 1213 else 1214 continue; 1215 1216 for (i = 0; i < ef->nprogtab; i++) { 1217 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1218 startp = (Elf_Addr)ef->progtab[i].addr; 1219 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1220 break; 1221 } 1222 } 1223 if (i == ef->nprogtab) 1224 continue; 1225 1226 sym->st_value = start ? startp : stopp; 1227 sym->st_shndx = i; 1228 } 1229 } 1230 1231 static void 1232 link_elf_reloc_local(linker_file_t lf) 1233 { 1234 elf_file_t ef = (elf_file_t)lf; 1235 const Elf_Rel *rellim; 1236 const Elf_Rel *rel; 1237 const Elf_Rela *relalim; 1238 const Elf_Rela *rela; 1239 const Elf_Sym *sym; 1240 Elf_Addr base; 1241 int i; 1242 Elf_Size symidx; 1243 1244 link_elf_fix_link_set(ef); 1245 1246 /* Perform relocations without addend if there are any: */ 1247 for (i = 0; i < ef->nreltab; i++) { 1248 rel = ef->reltab[i].rel; 1249 if (rel == NULL) 1250 panic("lost a reltab!"); 1251 rellim = rel + ef->reltab[i].nrel; 1252 base = findbase(ef, ef->reltab[i].sec); 1253 if (base == 0) 1254 panic("lost base for reltab"); 1255 for ( ; rel < rellim; rel++) { 1256 symidx = ELF_R_SYM(rel->r_info); 1257 if (symidx >= ef->ddbsymcnt) 1258 continue; 1259 sym = ef->ddbsymtab + symidx; 1260 /* Only do local relocs */ 1261 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1262 continue; 1263 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1264 elf_obj_lookup); 1265 } 1266 } 1267 1268 /* Perform relocations with addend if there are any: */ 1269 for (i = 0; i < ef->nrelatab; i++) { 1270 rela = ef->relatab[i].rela; 1271 if (rela == NULL) 1272 panic("lost a relatab!"); 1273 relalim = rela + ef->relatab[i].nrela; 1274 base = findbase(ef, ef->relatab[i].sec); 1275 if (base == 0) 1276 panic("lost base for relatab"); 1277 for ( ; rela < relalim; rela++) { 1278 symidx = ELF_R_SYM(rela->r_info); 1279 if (symidx >= ef->ddbsymcnt) 1280 continue; 1281 sym = ef->ddbsymtab + symidx; 1282 /* Only do local relocs */ 1283 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1284 continue; 1285 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1286 elf_obj_lookup); 1287 } 1288 } 1289 } 1290