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