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 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 668 round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE); 669 if (error) { 670 vm_object_deallocate(ef->object); 671 ef->object = 0; 672 goto out; 673 } 674 675 /* Wire the pages */ 676 error = vm_map_wire(kernel_map, mapbase, 677 mapbase + round_page(mapsize), 678 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 679 if (error != KERN_SUCCESS) { 680 error = ENOMEM; 681 goto out; 682 } 683 684 /* Inform the kld system about the situation */ 685 lf->address = ef->address = (caddr_t)mapbase; 686 lf->size = mapsize; 687 688 /* 689 * Now load code/data(progbits), zero bss(nobits), allocate space for 690 * and load relocs 691 */ 692 pb = 0; 693 rl = 0; 694 ra = 0; 695 alignmask = 0; 696 for (i = 0; i < hdr->e_shnum; i++) { 697 switch (shdr[i].sh_type) { 698 case SHT_PROGBITS: 699 case SHT_NOBITS: 700 alignmask = shdr[i].sh_addralign - 1; 701 mapbase += alignmask; 702 mapbase &= ~alignmask; 703 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase; 704 if (shdr[i].sh_type == SHT_PROGBITS) { 705 ef->progtab[pb].name = "<<PROGBITS>>"; 706 error = vn_rdwr(UIO_READ, nd.ni_vp, 707 ef->progtab[pb].addr, 708 shdr[i].sh_size, shdr[i].sh_offset, 709 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 710 NOCRED, &resid, td); 711 if (error) 712 goto out; 713 if (resid != 0){ 714 error = EINVAL; 715 goto out; 716 } 717 } else { 718 ef->progtab[pb].name = "<<NOBITS>>"; 719 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 720 } 721 ef->progtab[pb].size = shdr[i].sh_size; 722 ef->progtab[pb].sec = i; 723 if (ef->shstrtab && shdr[i].sh_name != 0) 724 ef->progtab[pb].name = 725 ef->shstrtab + shdr[i].sh_name; 726 727 /* Update all symbol values with the offset. */ 728 for (j = 0; j < ef->ddbsymcnt; j++) { 729 es = &ef->ddbsymtab[j]; 730 if (es->st_shndx != i) 731 continue; 732 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 733 } 734 mapbase += shdr[i].sh_size; 735 pb++; 736 break; 737 case SHT_REL: 738 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 739 M_WAITOK); 740 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 741 ef->reltab[rl].sec = shdr[i].sh_info; 742 error = vn_rdwr(UIO_READ, nd.ni_vp, 743 (void *)ef->reltab[rl].rel, 744 shdr[i].sh_size, shdr[i].sh_offset, 745 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 746 &resid, td); 747 if (error) 748 goto out; 749 if (resid != 0){ 750 error = EINVAL; 751 goto out; 752 } 753 rl++; 754 break; 755 case SHT_RELA: 756 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 757 M_WAITOK); 758 ef->relatab[ra].nrela = 759 shdr[i].sh_size / sizeof(Elf_Rela); 760 ef->relatab[ra].sec = shdr[i].sh_info; 761 error = vn_rdwr(UIO_READ, nd.ni_vp, 762 (void *)ef->relatab[ra].rela, 763 shdr[i].sh_size, shdr[i].sh_offset, 764 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 765 &resid, td); 766 if (error) 767 goto out; 768 if (resid != 0){ 769 error = EINVAL; 770 goto out; 771 } 772 ra++; 773 break; 774 } 775 } 776 if (pb != ef->nprogtab) 777 panic("lost progbits"); 778 if (rl != ef->nrel) 779 panic("lost rel"); 780 if (ra != ef->nrela) 781 panic("lost rela"); 782 if (mapbase != (vm_offset_t)ef->address + mapsize) 783 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 784 mapbase, ef->address, mapsize, 785 (vm_offset_t)ef->address + mapsize); 786 787 /* Local intra-module relocations */ 788 link_elf_reloc_local(lf); 789 790 /* Pull in dependencies */ 791 error = linker_load_dependencies(lf); 792 if (error) 793 goto out; 794 795 /* External relocations */ 796 error = relocate_file(ef); 797 if (error) 798 goto out; 799 800 /* Notify MD code that a module is being loaded. */ 801 error = elf_cpu_load_file(lf); 802 if (error) 803 goto out; 804 805 *result = lf; 806 807 out: 808 if (error && lf) 809 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 810 if (hdr) 811 free(hdr, M_LINKER); 812 VOP_UNLOCK(nd.ni_vp, 0); 813 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 814 VFS_UNLOCK_GIANT(vfslocked); 815 816 return error; 817 } 818 819 static void 820 link_elf_unload_file(linker_file_t file) 821 { 822 elf_file_t ef = (elf_file_t) file; 823 int i; 824 825 /* Notify MD code that a module is being unloaded. */ 826 elf_cpu_unload_file(file); 827 828 if (ef->preloaded) { 829 if (ef->reltab) 830 free(ef->reltab, M_LINKER); 831 if (ef->relatab) 832 free(ef->relatab, M_LINKER); 833 if (ef->progtab) 834 free(ef->progtab, M_LINKER); 835 if (ef->ctftab) 836 free(ef->ctftab, M_LINKER); 837 if (ef->ctfoff) 838 free(ef->ctfoff, M_LINKER); 839 if (ef->typoff) 840 free(ef->typoff, M_LINKER); 841 if (file->filename != NULL) 842 preload_delete_name(file->filename); 843 /* XXX reclaim module memory? */ 844 return; 845 } 846 847 for (i = 0; i < ef->nrel; i++) 848 if (ef->reltab[i].rel) 849 free(ef->reltab[i].rel, M_LINKER); 850 for (i = 0; i < ef->nrela; i++) 851 if (ef->relatab[i].rela) 852 free(ef->relatab[i].rela, M_LINKER); 853 if (ef->reltab) 854 free(ef->reltab, M_LINKER); 855 if (ef->relatab) 856 free(ef->relatab, M_LINKER); 857 if (ef->progtab) 858 free(ef->progtab, M_LINKER); 859 860 if (ef->object) { 861 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 862 (vm_offset_t) ef->address + 863 (ef->object->size << PAGE_SHIFT)); 864 } 865 if (ef->e_shdr) 866 free(ef->e_shdr, M_LINKER); 867 if (ef->ddbsymtab) 868 free(ef->ddbsymtab, M_LINKER); 869 if (ef->ddbstrtab) 870 free(ef->ddbstrtab, M_LINKER); 871 if (ef->shstrtab) 872 free(ef->shstrtab, M_LINKER); 873 if (ef->ctftab) 874 free(ef->ctftab, M_LINKER); 875 if (ef->ctfoff) 876 free(ef->ctfoff, M_LINKER); 877 if (ef->typoff) 878 free(ef->typoff, M_LINKER); 879 } 880 881 static const char * 882 symbol_name(elf_file_t ef, Elf_Size r_info) 883 { 884 const Elf_Sym *ref; 885 886 if (ELF_R_SYM(r_info)) { 887 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 888 return ef->ddbstrtab + ref->st_name; 889 } else 890 return NULL; 891 } 892 893 static Elf_Addr 894 findbase(elf_file_t ef, int sec) 895 { 896 int i; 897 Elf_Addr base = 0; 898 899 for (i = 0; i < ef->nprogtab; i++) { 900 if (sec == ef->progtab[i].sec) { 901 base = (Elf_Addr)ef->progtab[i].addr; 902 break; 903 } 904 } 905 return base; 906 } 907 908 static int 909 relocate_file(elf_file_t ef) 910 { 911 const Elf_Rel *rellim; 912 const Elf_Rel *rel; 913 const Elf_Rela *relalim; 914 const Elf_Rela *rela; 915 const char *symname; 916 const Elf_Sym *sym; 917 int i; 918 Elf_Size symidx; 919 Elf_Addr base; 920 921 922 /* Perform relocations without addend if there are any: */ 923 for (i = 0; i < ef->nrel; i++) { 924 rel = ef->reltab[i].rel; 925 if (rel == NULL) 926 panic("lost a reltab!"); 927 rellim = rel + ef->reltab[i].nrel; 928 base = findbase(ef, ef->reltab[i].sec); 929 if (base == 0) 930 panic("lost base for reltab"); 931 for ( ; rel < rellim; rel++) { 932 symidx = ELF_R_SYM(rel->r_info); 933 if (symidx >= ef->ddbsymcnt) 934 continue; 935 sym = ef->ddbsymtab + symidx; 936 /* Local relocs are already done */ 937 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 938 continue; 939 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 940 elf_obj_lookup)) { 941 symname = symbol_name(ef, rel->r_info); 942 printf("link_elf_obj: symbol %s undefined\n", 943 symname); 944 return ENOENT; 945 } 946 } 947 } 948 949 /* Perform relocations with addend if there are any: */ 950 for (i = 0; i < ef->nrela; i++) { 951 rela = ef->relatab[i].rela; 952 if (rela == NULL) 953 panic("lost a relatab!"); 954 relalim = rela + ef->relatab[i].nrela; 955 base = findbase(ef, ef->relatab[i].sec); 956 if (base == 0) 957 panic("lost base for relatab"); 958 for ( ; rela < relalim; rela++) { 959 symidx = ELF_R_SYM(rela->r_info); 960 if (symidx >= ef->ddbsymcnt) 961 continue; 962 sym = ef->ddbsymtab + symidx; 963 /* Local relocs are already done */ 964 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 965 continue; 966 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 967 elf_obj_lookup)) { 968 symname = symbol_name(ef, rela->r_info); 969 printf("link_elf_obj: symbol %s undefined\n", 970 symname); 971 return ENOENT; 972 } 973 } 974 } 975 976 return 0; 977 } 978 979 static int 980 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 981 { 982 elf_file_t ef = (elf_file_t) lf; 983 const Elf_Sym *symp; 984 const char *strp; 985 int i; 986 987 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 988 strp = ef->ddbstrtab + symp->st_name; 989 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 990 *sym = (c_linker_sym_t) symp; 991 return 0; 992 } 993 } 994 return ENOENT; 995 } 996 997 static int 998 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 999 linker_symval_t *symval) 1000 { 1001 elf_file_t ef = (elf_file_t) lf; 1002 const Elf_Sym *es = (const Elf_Sym*) sym; 1003 1004 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1005 symval->name = ef->ddbstrtab + es->st_name; 1006 symval->value = (caddr_t)es->st_value; 1007 symval->size = es->st_size; 1008 return 0; 1009 } 1010 return ENOENT; 1011 } 1012 1013 static int 1014 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1015 c_linker_sym_t *sym, long *diffp) 1016 { 1017 elf_file_t ef = (elf_file_t) lf; 1018 u_long off = (uintptr_t) (void *) value; 1019 u_long diff = off; 1020 u_long st_value; 1021 const Elf_Sym *es; 1022 const Elf_Sym *best = 0; 1023 int i; 1024 1025 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1026 if (es->st_name == 0) 1027 continue; 1028 st_value = es->st_value; 1029 if (off >= st_value) { 1030 if (off - st_value < diff) { 1031 diff = off - st_value; 1032 best = es; 1033 if (diff == 0) 1034 break; 1035 } else if (off - st_value == diff) { 1036 best = es; 1037 } 1038 } 1039 } 1040 if (best == 0) 1041 *diffp = off; 1042 else 1043 *diffp = diff; 1044 *sym = (c_linker_sym_t) best; 1045 1046 return 0; 1047 } 1048 1049 /* 1050 * Look up a linker set on an ELF system. 1051 */ 1052 static int 1053 link_elf_lookup_set(linker_file_t lf, const char *name, 1054 void ***startp, void ***stopp, int *countp) 1055 { 1056 elf_file_t ef = (elf_file_t)lf; 1057 void **start, **stop; 1058 int i, count; 1059 1060 /* Relative to section number */ 1061 for (i = 0; i < ef->nprogtab; i++) { 1062 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1063 strcmp(ef->progtab[i].name + 4, name) == 0) { 1064 start = (void **)ef->progtab[i].addr; 1065 stop = (void **)((char *)ef->progtab[i].addr + 1066 ef->progtab[i].size); 1067 count = stop - start; 1068 if (startp) 1069 *startp = start; 1070 if (stopp) 1071 *stopp = stop; 1072 if (countp) 1073 *countp = count; 1074 return (0); 1075 } 1076 } 1077 return (ESRCH); 1078 } 1079 1080 static int 1081 link_elf_each_function_name(linker_file_t file, 1082 int (*callback)(const char *, void *), void *opaque) 1083 { 1084 elf_file_t ef = (elf_file_t)file; 1085 const Elf_Sym *symp; 1086 int i, error; 1087 1088 /* Exhaustive search */ 1089 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1090 if (symp->st_value != 0 && 1091 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1092 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1093 if (error) 1094 return (error); 1095 } 1096 } 1097 return (0); 1098 } 1099 1100 static int 1101 link_elf_each_function_nameval(linker_file_t file, 1102 linker_function_nameval_callback_t callback, void *opaque) 1103 { 1104 linker_symval_t symval; 1105 elf_file_t ef = (elf_file_t)file; 1106 const Elf_Sym* symp; 1107 int i, error; 1108 1109 /* Exhaustive search */ 1110 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1111 if (symp->st_value != 0 && 1112 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1113 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1114 if (error) 1115 return (error); 1116 error = callback(file, i, &symval, opaque); 1117 if (error) 1118 return (error); 1119 } 1120 } 1121 return (0); 1122 } 1123 1124 /* 1125 * Symbol lookup function that can be used when the symbol index is known (ie 1126 * in relocations). It uses the symbol index instead of doing a fully fledged 1127 * hash table based lookup when such is valid. For example for local symbols. 1128 * This is not only more efficient, it's also more correct. It's not always 1129 * the case that the symbol can be found through the hash table. 1130 */ 1131 static Elf_Addr 1132 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1133 { 1134 elf_file_t ef = (elf_file_t)lf; 1135 const Elf_Sym *sym; 1136 const char *symbol; 1137 Elf_Addr ret; 1138 1139 /* Don't even try to lookup the symbol if the index is bogus. */ 1140 if (symidx >= ef->ddbsymcnt) 1141 return (0); 1142 1143 sym = ef->ddbsymtab + symidx; 1144 1145 /* Quick answer if there is a definition included. */ 1146 if (sym->st_shndx != SHN_UNDEF) 1147 return (sym->st_value); 1148 1149 /* If we get here, then it is undefined and needs a lookup. */ 1150 switch (ELF_ST_BIND(sym->st_info)) { 1151 case STB_LOCAL: 1152 /* Local, but undefined? huh? */ 1153 return (0); 1154 1155 case STB_GLOBAL: 1156 /* Relative to Data or Function name */ 1157 symbol = ef->ddbstrtab + sym->st_name; 1158 1159 /* Force a lookup failure if the symbol name is bogus. */ 1160 if (*symbol == 0) 1161 return (0); 1162 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1163 return ret; 1164 1165 case STB_WEAK: 1166 printf("link_elf_obj: Weak symbols not supported\n"); 1167 return (0); 1168 1169 default: 1170 return (0); 1171 } 1172 } 1173 1174 static void 1175 link_elf_fix_link_set(elf_file_t ef) 1176 { 1177 static const char startn[] = "__start_"; 1178 static const char stopn[] = "__stop_"; 1179 Elf_Sym *sym; 1180 const char *sym_name, *linkset_name; 1181 Elf_Addr startp, stopp; 1182 Elf_Size symidx; 1183 int start, i; 1184 1185 startp = stopp = 0; 1186 for (symidx = 1 /* zero entry is special */; 1187 symidx < ef->ddbsymcnt; symidx++) { 1188 sym = ef->ddbsymtab + symidx; 1189 if (sym->st_shndx != SHN_UNDEF) 1190 continue; 1191 1192 sym_name = ef->ddbstrtab + sym->st_name; 1193 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1194 start = 1; 1195 linkset_name = sym_name + sizeof(startn) - 1; 1196 } 1197 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1198 start = 0; 1199 linkset_name = sym_name + sizeof(stopn) - 1; 1200 } 1201 else 1202 continue; 1203 1204 for (i = 0; i < ef->nprogtab; i++) { 1205 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1206 startp = (Elf_Addr)ef->progtab[i].addr; 1207 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1208 break; 1209 } 1210 } 1211 if (i == ef->nprogtab) 1212 continue; 1213 1214 sym->st_value = start ? startp : stopp; 1215 sym->st_shndx = i; 1216 } 1217 } 1218 1219 static void 1220 link_elf_reloc_local(linker_file_t lf) 1221 { 1222 elf_file_t ef = (elf_file_t)lf; 1223 const Elf_Rel *rellim; 1224 const Elf_Rel *rel; 1225 const Elf_Rela *relalim; 1226 const Elf_Rela *rela; 1227 const Elf_Sym *sym; 1228 Elf_Addr base; 1229 int i; 1230 Elf_Size symidx; 1231 1232 link_elf_fix_link_set(ef); 1233 1234 /* Perform relocations without addend if there are any: */ 1235 for (i = 0; i < ef->nrel; i++) { 1236 rel = ef->reltab[i].rel; 1237 if (rel == NULL) 1238 panic("lost a reltab!"); 1239 rellim = rel + ef->reltab[i].nrel; 1240 base = findbase(ef, ef->reltab[i].sec); 1241 if (base == 0) 1242 panic("lost base for reltab"); 1243 for ( ; rel < rellim; rel++) { 1244 symidx = ELF_R_SYM(rel->r_info); 1245 if (symidx >= ef->ddbsymcnt) 1246 continue; 1247 sym = ef->ddbsymtab + symidx; 1248 /* Only do local relocs */ 1249 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1250 continue; 1251 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1252 elf_obj_lookup); 1253 } 1254 } 1255 1256 /* Perform relocations with addend if there are any: */ 1257 for (i = 0; i < ef->nrela; i++) { 1258 rela = ef->relatab[i].rela; 1259 if (rela == NULL) 1260 panic("lost a relatab!"); 1261 relalim = rela + ef->relatab[i].nrela; 1262 base = findbase(ef, ef->relatab[i].sec); 1263 if (base == 0) 1264 panic("lost base for relatab"); 1265 for ( ; rela < relalim; rela++) { 1266 symidx = ELF_R_SYM(rela->r_info); 1267 if (symidx >= ef->ddbsymcnt) 1268 continue; 1269 sym = ef->ddbsymtab + symidx; 1270 /* Only do local relocs */ 1271 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1272 continue; 1273 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1274 elf_obj_lookup); 1275 } 1276 } 1277 } 1278