1 /*- 2 * Copyright (c) 1998 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 * $FreeBSD: src/sys/kern/link_elf.c,v 1.24 1999/12/24 15:33:36 bde Exp $ 28 */ 29 30 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/systm.h> 33 #include <sys/malloc.h> 34 #include <sys/proc.h> 35 #include <sys/nlookup.h> 36 #include <sys/fcntl.h> 37 #include <sys/vnode.h> 38 #include <sys/linker.h> 39 #include <machine/elf.h> 40 41 #include <vm/vm.h> 42 #include <vm/vm_param.h> 43 #include <vm/vm_zone.h> 44 #include <vm/vm_object.h> 45 #include <vm/vm_kern.h> 46 #include <vm/vm_extern.h> 47 #include <sys/lock.h> 48 #include <vm/pmap.h> 49 #include <vm/vm_map.h> 50 51 static int link_elf_obj_preload_file(const char *, linker_file_t *); 52 static int link_elf_obj_preload_finish(linker_file_t); 53 static int link_elf_obj_load_file(const char *, linker_file_t *); 54 static int 55 link_elf_obj_lookup_symbol(linker_file_t, const char *, 56 c_linker_sym_t *); 57 static int link_elf_obj_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t *); 58 static int 59 link_elf_obj_search_symbol(linker_file_t, caddr_t value, 60 c_linker_sym_t * sym, long *diffp); 61 62 static void link_elf_obj_unload_file(linker_file_t); 63 static int 64 link_elf_obj_lookup_set(linker_file_t, const char *, 65 void ***, void ***, int *); 66 static void link_elf_obj_reloc_local(linker_file_t lf); 67 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *); 68 69 static struct linker_class_ops link_elf_obj_class_ops = { 70 link_elf_obj_load_file, 71 link_elf_obj_preload_file, 72 }; 73 74 static struct linker_file_ops link_elf_obj_file_ops = { 75 .lookup_symbol = link_elf_obj_lookup_symbol, 76 .symbol_values = link_elf_obj_symbol_values, 77 .search_symbol = link_elf_obj_search_symbol, 78 .preload_finish = link_elf_obj_preload_finish, 79 .unload = link_elf_obj_unload_file, 80 .lookup_set = link_elf_obj_lookup_set, 81 }; 82 83 typedef struct { 84 void *addr; 85 Elf_Off size; 86 int flags; 87 int sec; /* Original section */ 88 char *name; 89 } Elf_progent; 90 91 typedef struct { 92 Elf_Rel *rel; 93 int nrel; 94 int sec; 95 } Elf_relent; 96 97 typedef struct { 98 Elf_Rela *rela; 99 int nrela; 100 int sec; 101 } Elf_relaent; 102 103 104 typedef struct elf_file { 105 int preloaded; 106 107 caddr_t address; /* Relocation address */ 108 size_t bytes; /* Chunk size in bytes */ 109 vm_object_t object; /* VM object to hold file pages */ 110 Elf_Shdr *e_shdr; 111 112 Elf_progent *progtab; 113 int nprogtab; 114 115 Elf_relaent *relatab; 116 int nrelatab; 117 118 Elf_relent *reltab; 119 int nreltab; 120 121 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 122 long ddbsymcnt; /* Number of symbols */ 123 caddr_t ddbstrtab; /* String table */ 124 long ddbstrcnt; /* number of bytes in string table */ 125 126 caddr_t shstrtab; /* Section name string table */ 127 long shstrcnt; /* number of bytes in string table */ 128 129 caddr_t ctftab; /* CTF table */ 130 long ctfcnt; /* number of bytes in CTF table */ 131 caddr_t ctfoff; /* CTF offset table */ 132 caddr_t typoff; /* Type offset table */ 133 long typlen; /* Number of type entries. */ 134 135 } *elf_file_t; 136 137 static int relocate_file(linker_file_t lf); 138 139 /* 140 * The kernel symbol table starts here. 141 */ 142 extern struct _dynamic _DYNAMIC; 143 144 static void 145 link_elf_obj_init(void *arg) 146 { 147 #if ELF_TARG_CLASS == ELFCLASS32 148 linker_add_class("elf32", NULL, &link_elf_obj_class_ops); 149 #else 150 linker_add_class("elf64", NULL, &link_elf_obj_class_ops); 151 #endif 152 } 153 154 SYSINIT(link_elf, SI_BOOT2_KLD, SI_ORDER_SECOND, link_elf_obj_init, 0); 155 156 static void 157 link_elf_obj_error(const char *file, const char *s) 158 { 159 kprintf("kldload: %s: %s\n", file, s); 160 } 161 162 static int 163 link_elf_obj_preload_file(const char *filename, linker_file_t *result) 164 { 165 Elf_Ehdr *hdr; 166 Elf_Shdr *shdr; 167 Elf_Sym *es; 168 caddr_t modptr, baseptr, sizeptr; 169 char *type; 170 elf_file_t ef; 171 linker_file_t lf; 172 Elf_Addr off; 173 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 174 175 /* 176 * Look to see if we have the module preloaded. 177 */ 178 modptr = preload_search_by_name(filename); 179 if (modptr == NULL) 180 return ENOENT; 181 182 /* It's preloaded, check we can handle it and collect information */ 183 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 184 baseptr = preload_search_info(modptr, MODINFO_ADDR); 185 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 186 hdr = (Elf_Ehdr *) preload_search_info(modptr, MODINFO_METADATA | 187 MODINFOMD_ELFHDR); 188 shdr = (Elf_Shdr *) preload_search_info(modptr, MODINFO_METADATA | 189 MODINFOMD_SHDR); 190 if (type == NULL || 191 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " obj module") != 0 && 192 strcmp(type, "elf obj module") != 0)) { 193 return (EFTYPE); 194 } 195 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || shdr == NULL) 196 return (EINVAL); 197 198 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO); 199 ef->preloaded = 1; 200 ef->address = *(caddr_t *) baseptr; 201 ef->bytes = 0; 202 lf = linker_make_file(filename, ef, &link_elf_obj_file_ops); 203 if (lf == NULL) { 204 kfree(ef, M_LINKER); 205 return ENOMEM; 206 } 207 lf->address = ef->address; 208 lf->size = *(size_t *) sizeptr; 209 210 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 211 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 212 hdr->e_ident[EI_VERSION] != EV_CURRENT || 213 hdr->e_version != EV_CURRENT || 214 hdr->e_type != ET_REL || 215 hdr->e_machine != ELF_TARG_MACH) { 216 error = EFTYPE; 217 goto out; 218 } 219 ef->e_shdr = shdr; 220 221 /* Scan the section header for information and table sizing. */ 222 symtabindex = -1; 223 symstrindex = -1; 224 for (i = 0; i < hdr->e_shnum; i++) { 225 switch (shdr[i].sh_type) { 226 case SHT_PROGBITS: 227 case SHT_NOBITS: 228 ef->nprogtab++; 229 break; 230 case SHT_SYMTAB: 231 symtabindex = i; 232 symstrindex = shdr[i].sh_link; 233 break; 234 case SHT_REL: 235 ef->nreltab++; 236 break; 237 case SHT_RELA: 238 ef->nrelatab++; 239 break; 240 } 241 } 242 243 shstrindex = hdr->e_shstrndx; 244 if (ef->nprogtab == 0 || symstrindex < 0 || 245 symstrindex >= hdr->e_shnum || 246 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 247 shstrindex >= hdr->e_shnum || 248 shdr[shstrindex].sh_type != SHT_STRTAB) { 249 error = ENOEXEC; 250 goto out; 251 } 252 /* Allocate space for tracking the load chunks */ 253 if (ef->nprogtab != 0) 254 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab), 255 M_LINKER, M_WAITOK | M_ZERO); 256 if (ef->nreltab != 0) 257 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab), 258 M_LINKER, M_WAITOK | M_ZERO); 259 if (ef->nrelatab != 0) 260 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab), 261 M_LINKER, M_WAITOK | M_ZERO); 262 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 263 (ef->nreltab != 0 && ef->reltab == NULL) || 264 (ef->nrelatab != 0 && ef->relatab == NULL)) { 265 error = ENOMEM; 266 goto out; 267 } 268 /* XXX, relocate the sh_addr fields saved by the loader. */ 269 off = 0; 270 for (i = 0; i < hdr->e_shnum; i++) { 271 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 272 off = shdr[i].sh_addr; 273 } 274 for (i = 0; i < hdr->e_shnum; i++) { 275 if (shdr[i].sh_addr != 0) 276 shdr[i].sh_addr = shdr[i].sh_addr - off + 277 (Elf_Addr) ef->address; 278 } 279 280 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 281 ef->ddbsymtab = (Elf_Sym *) shdr[symtabindex].sh_addr; 282 ef->ddbstrcnt = shdr[symstrindex].sh_size; 283 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 284 ef->shstrcnt = shdr[shstrindex].sh_size; 285 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 286 287 /* Now fill out progtab and the relocation tables. */ 288 pb = 0; 289 rl = 0; 290 ra = 0; 291 for (i = 0; i < hdr->e_shnum; i++) { 292 switch (shdr[i].sh_type) { 293 case SHT_PROGBITS: 294 case SHT_NOBITS: 295 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 296 if (shdr[i].sh_type == SHT_PROGBITS) 297 ef->progtab[pb].name = "<<PROGBITS>>"; 298 else 299 ef->progtab[pb].name = "<<NOBITS>>"; 300 ef->progtab[pb].size = shdr[i].sh_size; 301 ef->progtab[pb].sec = i; 302 if (ef->shstrtab && shdr[i].sh_name != 0) 303 ef->progtab[pb].name = 304 ef->shstrtab + shdr[i].sh_name; 305 #if 0 306 if (ef->progtab[pb].name != NULL && 307 !strcmp(ef->progtab[pb].name, "set_pcpu")) { 308 void *dpcpu; 309 310 dpcpu = dpcpu_alloc(shdr[i].sh_size); 311 if (dpcpu == NULL) { 312 error = ENOSPC; 313 goto out; 314 } 315 memcpy(dpcpu, ef->progtab[pb].addr, 316 ef->progtab[pb].size); 317 dpcpu_copy(dpcpu, shdr[i].sh_size); 318 ef->progtab[pb].addr = dpcpu; 319 #ifdef VIMAGE 320 } else if (ef->progtab[pb].name != NULL && 321 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 322 void *vnet_data; 323 324 vnet_data = vnet_data_alloc(shdr[i].sh_size); 325 if (vnet_data == NULL) { 326 error = ENOSPC; 327 goto out; 328 } 329 memcpy(vnet_data, ef->progtab[pb].addr, 330 ef->progtab[pb].size); 331 vnet_data_copy(vnet_data, shdr[i].sh_size); 332 ef->progtab[pb].addr = vnet_data; 333 #endif 334 } 335 #endif 336 /* Update all symbol values with the offset. */ 337 for (j = 0; j < ef->ddbsymcnt; j++) { 338 es = &ef->ddbsymtab[j]; 339 if (es->st_shndx != i) 340 continue; 341 es->st_value += (Elf_Addr) ef->progtab[pb].addr; 342 } 343 pb++; 344 break; 345 case SHT_REL: 346 ef->reltab[rl].rel = (Elf_Rel *) shdr[i].sh_addr; 347 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 348 ef->reltab[rl].sec = shdr[i].sh_info; 349 rl++; 350 break; 351 case SHT_RELA: 352 ef->relatab[ra].rela = (Elf_Rela *) shdr[i].sh_addr; 353 ef->relatab[ra].nrela = 354 shdr[i].sh_size / sizeof(Elf_Rela); 355 ef->relatab[ra].sec = shdr[i].sh_info; 356 ra++; 357 break; 358 } 359 } 360 if (pb != ef->nprogtab) 361 panic("lost progbits"); 362 if (rl != ef->nreltab) 363 panic("lost reltab"); 364 if (ra != ef->nrelatab) 365 panic("lost relatab"); 366 367 /* Local intra-module relocations */ 368 link_elf_obj_reloc_local(lf); 369 370 *result = lf; 371 return (0); 372 373 out: 374 /* preload not done this way */ 375 linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ ); 376 return (error); 377 } 378 379 static int 380 link_elf_obj_preload_finish(linker_file_t lf) 381 { 382 int error; 383 384 error = relocate_file(lf); 385 386 return (error); 387 } 388 389 static int 390 link_elf_obj_load_file(const char *filename, linker_file_t * result) 391 { 392 struct nlookupdata nd; 393 struct thread *td = curthread; /* XXX */ 394 struct proc *p = td->td_proc; 395 char *pathname; 396 struct vnode *vp; 397 Elf_Ehdr *hdr; 398 Elf_Shdr *shdr; 399 Elf_Sym *es; 400 int nbytes, i, j; 401 vm_offset_t mapbase; 402 size_t mapsize; 403 int error = 0; 404 int resid; 405 elf_file_t ef; 406 linker_file_t lf; 407 int symtabindex; 408 int symstrindex; 409 int shstrindex; 410 int nsym; 411 int pb, rl, ra; 412 int alignmask; 413 414 /* XXX Hack for firmware loading where p == NULL */ 415 if (p == NULL) { 416 p = &proc0; 417 } 418 419 KKASSERT(p != NULL); 420 if (p->p_ucred == NULL) { 421 kprintf("link_elf_obj_load_file: cannot load '%s' from filesystem" 422 " this early\n", filename); 423 return ENOENT; 424 } 425 shdr = NULL; 426 lf = NULL; 427 mapsize = 0; 428 hdr = NULL; 429 pathname = linker_search_path(filename); 430 if (pathname == NULL) 431 return ENOENT; 432 433 error = nlookup_init(&nd, pathname, UIO_SYSSPACE, NLC_FOLLOW | NLC_LOCKVP); 434 if (error == 0) 435 error = vn_open(&nd, NULL, FREAD, 0); 436 kfree(pathname, M_LINKER); 437 if (error) { 438 nlookup_done(&nd); 439 return error; 440 } 441 vp = nd.nl_open_vp; 442 nd.nl_open_vp = NULL; 443 nlookup_done(&nd); 444 445 /* 446 * Read the elf header from the file. 447 */ 448 hdr = kmalloc(sizeof(*hdr), M_LINKER, M_WAITOK); 449 error = vn_rdwr(UIO_READ, vp, (void *)hdr, sizeof(*hdr), 0, 450 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 451 if (error) 452 goto out; 453 if (resid != 0) { 454 error = ENOEXEC; 455 goto out; 456 } 457 if (!IS_ELF(*hdr)) { 458 error = ENOEXEC; 459 goto out; 460 } 461 462 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 463 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 464 link_elf_obj_error(filename, "Unsupported file layout"); 465 error = ENOEXEC; 466 goto out; 467 } 468 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 469 || hdr->e_version != EV_CURRENT) { 470 link_elf_obj_error(filename, "Unsupported file version"); 471 error = ENOEXEC; 472 goto out; 473 } 474 if (hdr->e_type != ET_REL) { 475 error = ENOSYS; 476 goto out; 477 } 478 if (hdr->e_machine != ELF_TARG_MACH) { 479 link_elf_obj_error(filename, "Unsupported machine"); 480 error = ENOEXEC; 481 goto out; 482 } 483 484 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO); 485 lf = linker_make_file(filename, ef, &link_elf_obj_file_ops); 486 if (lf == NULL) { 487 kfree(ef, M_LINKER); 488 error = ENOMEM; 489 goto out; 490 } 491 ef->nprogtab = 0; 492 ef->e_shdr = NULL; 493 ef->nreltab = 0; 494 ef->nrelatab = 0; 495 496 /* Allocate and read in the section header */ 497 nbytes = hdr->e_shnum * hdr->e_shentsize; 498 if (nbytes == 0 || hdr->e_shoff == 0 || 499 hdr->e_shentsize != sizeof(Elf_Shdr)) { 500 error = ENOEXEC; 501 goto out; 502 } 503 shdr = kmalloc(nbytes, M_LINKER, M_WAITOK); 504 ef->e_shdr = shdr; 505 error = vn_rdwr(UIO_READ, vp, (caddr_t) shdr, nbytes, hdr->e_shoff, 506 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 507 if (error) 508 goto out; 509 if (resid) { 510 error = ENOEXEC; 511 goto out; 512 } 513 /* Scan the section header for information and table sizing. */ 514 nsym = 0; 515 symtabindex = -1; 516 symstrindex = -1; 517 for (i = 0; i < hdr->e_shnum; i++) { 518 switch (shdr[i].sh_type) { 519 case SHT_PROGBITS: 520 case SHT_NOBITS: 521 ef->nprogtab++; 522 break; 523 case SHT_SYMTAB: 524 nsym++; 525 symtabindex = i; 526 symstrindex = shdr[i].sh_link; 527 break; 528 case SHT_REL: 529 ef->nreltab++; 530 break; 531 case SHT_RELA: 532 ef->nrelatab++; 533 break; 534 case SHT_STRTAB: 535 break; 536 } 537 } 538 if (ef->nprogtab == 0) { 539 link_elf_obj_error(filename, "file has no contents"); 540 error = ENOEXEC; 541 goto out; 542 } 543 if (nsym != 1) { 544 /* Only allow one symbol table for now */ 545 link_elf_obj_error(filename, "file has no valid symbol table"); 546 error = ENOEXEC; 547 goto out; 548 } 549 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 550 shdr[symstrindex].sh_type != SHT_STRTAB) { 551 link_elf_obj_error(filename, "file has invalid symbol strings"); 552 error = ENOEXEC; 553 goto out; 554 } 555 /* Allocate space for tracking the load chunks */ 556 if (ef->nprogtab != 0) 557 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab), 558 M_LINKER, M_WAITOK | M_ZERO); 559 if (ef->nreltab != 0) 560 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab), 561 M_LINKER, M_WAITOK | M_ZERO); 562 if (ef->nrelatab != 0) 563 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab), 564 M_LINKER, M_WAITOK | M_ZERO); 565 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 566 (ef->nreltab != 0 && ef->reltab == NULL) || 567 (ef->nrelatab != 0 && ef->relatab == NULL)) { 568 error = ENOMEM; 569 goto out; 570 } 571 if (symtabindex == -1) 572 panic("lost symbol table index"); 573 /* Allocate space for and load the symbol table */ 574 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 575 ef->ddbsymtab = kmalloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 576 error = vn_rdwr(UIO_READ, vp, (void *)ef->ddbsymtab, 577 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 578 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 579 if (error) 580 goto out; 581 if (resid != 0) { 582 error = EINVAL; 583 goto out; 584 } 585 if (symstrindex == -1) 586 panic("lost symbol string index"); 587 /* Allocate space for and load the symbol strings */ 588 ef->ddbstrcnt = shdr[symstrindex].sh_size; 589 ef->ddbstrtab = kmalloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 590 error = vn_rdwr(UIO_READ, vp, ef->ddbstrtab, 591 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 592 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 593 if (error) 594 goto out; 595 if (resid != 0) { 596 error = EINVAL; 597 goto out; 598 } 599 /* Do we have a string table for the section names? */ 600 shstrindex = -1; 601 if (hdr->e_shstrndx != 0 && 602 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 603 shstrindex = hdr->e_shstrndx; 604 ef->shstrcnt = shdr[shstrindex].sh_size; 605 ef->shstrtab = kmalloc(shdr[shstrindex].sh_size, M_LINKER, 606 M_WAITOK); 607 error = vn_rdwr(UIO_READ, vp, ef->shstrtab, 608 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 609 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 610 if (error) 611 goto out; 612 if (resid != 0) { 613 error = EINVAL; 614 goto out; 615 } 616 } 617 /* Size up code/data(progbits) and bss(nobits). */ 618 alignmask = 0; 619 for (i = 0; i < hdr->e_shnum; i++) { 620 switch (shdr[i].sh_type) { 621 case SHT_PROGBITS: 622 case SHT_NOBITS: 623 alignmask = shdr[i].sh_addralign - 1; 624 mapsize += alignmask; 625 mapsize &= ~alignmask; 626 mapsize += shdr[i].sh_size; 627 break; 628 } 629 } 630 631 /* 632 * We know how much space we need for the text/data/bss/etc. This 633 * stuff needs to be in a single chunk so that profiling etc can get 634 * the bounds and gdb can associate offsets with modules 635 */ 636 ef->object = vm_object_allocate(OBJT_DEFAULT, 637 round_page(mapsize) >> PAGE_SHIFT); 638 if (ef->object == NULL) { 639 error = ENOMEM; 640 goto out; 641 } 642 vm_object_hold(ef->object); 643 vm_object_reference_locked(ef->object); 644 ef->address = (caddr_t) vm_map_min(&kernel_map); 645 ef->bytes = 0; 646 647 /* 648 * In order to satisfy x86_64's architectural requirements on the 649 * location of code and data in the kernel's address space, request a 650 * mapping that is above the kernel. 651 * 652 * vkernel64's text+data is outside the managed VM space entirely. 653 */ 654 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL) 655 error = vkernel_module_memory_alloc(&mapbase, round_page(mapsize)); 656 vm_object_drop(ef->object); 657 #else 658 mapbase = KERNBASE; 659 error = vm_map_find(&kernel_map, ef->object, 0, &mapbase, 660 round_page(mapsize), PAGE_SIZE, 661 TRUE, VM_MAPTYPE_NORMAL, 662 VM_PROT_ALL, VM_PROT_ALL, FALSE); 663 vm_object_drop(ef->object); 664 if (error) { 665 vm_object_deallocate(ef->object); 666 ef->object = NULL; 667 goto out; 668 } 669 /* Wire the pages */ 670 error = vm_map_wire(&kernel_map, mapbase, 671 mapbase + round_page(mapsize), 0); 672 #endif 673 if (error != KERN_SUCCESS) { 674 error = ENOMEM; 675 goto out; 676 } 677 /* Inform the kld system about the situation */ 678 lf->address = ef->address = (caddr_t) mapbase; 679 lf->size = round_page(mapsize); 680 ef->bytes = mapsize; 681 682 /* 683 * Now load code/data(progbits), zero bss(nobits), allocate space for 684 * and load relocs 685 */ 686 pb = 0; 687 rl = 0; 688 ra = 0; 689 alignmask = 0; 690 for (i = 0; i < hdr->e_shnum; i++) { 691 switch (shdr[i].sh_type) { 692 case SHT_PROGBITS: 693 case SHT_NOBITS: 694 alignmask = shdr[i].sh_addralign - 1; 695 mapbase += alignmask; 696 mapbase &= ~alignmask; 697 if (ef->shstrtab && shdr[i].sh_name != 0) 698 ef->progtab[pb].name = 699 ef->shstrtab + shdr[i].sh_name; 700 else if (shdr[i].sh_type == SHT_PROGBITS) 701 ef->progtab[pb].name = "<<PROGBITS>>"; 702 else 703 ef->progtab[pb].name = "<<NOBITS>>"; 704 #if 0 705 if (ef->progtab[pb].name != NULL && 706 !strcmp(ef->progtab[pb].name, "set_pcpu")) 707 ef->progtab[pb].addr = 708 dpcpu_alloc(shdr[i].sh_size); 709 #ifdef VIMAGE 710 else if (ef->progtab[pb].name != NULL && 711 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 712 ef->progtab[pb].addr = 713 vnet_data_alloc(shdr[i].sh_size); 714 #endif 715 else 716 #endif 717 ef->progtab[pb].addr = 718 (void *)(uintptr_t) mapbase; 719 if (ef->progtab[pb].addr == NULL) { 720 error = ENOSPC; 721 goto out; 722 } 723 ef->progtab[pb].size = shdr[i].sh_size; 724 ef->progtab[pb].sec = i; 725 if (shdr[i].sh_type == SHT_PROGBITS) { 726 error = vn_rdwr(UIO_READ, vp, 727 ef->progtab[pb].addr, 728 shdr[i].sh_size, shdr[i].sh_offset, 729 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 730 &resid); 731 if (error) 732 goto out; 733 if (resid != 0) { 734 error = EINVAL; 735 goto out; 736 } 737 #if 0 738 /* Initialize the per-cpu or vnet area. */ 739 if (ef->progtab[pb].addr != (void *)mapbase && 740 !strcmp(ef->progtab[pb].name, "set_pcpu")) 741 dpcpu_copy(ef->progtab[pb].addr, 742 shdr[i].sh_size); 743 #ifdef VIMAGE 744 else if (ef->progtab[pb].addr != 745 (void *)mapbase && 746 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 747 vnet_data_copy(ef->progtab[pb].addr, 748 shdr[i].sh_size); 749 #endif 750 #endif 751 } else 752 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 753 754 /* Update all symbol values with the offset. */ 755 for (j = 0; j < ef->ddbsymcnt; j++) { 756 es = &ef->ddbsymtab[j]; 757 if (es->st_shndx != i) 758 continue; 759 es->st_value += (Elf_Addr) ef->progtab[pb].addr; 760 } 761 mapbase += shdr[i].sh_size; 762 pb++; 763 break; 764 case SHT_REL: 765 ef->reltab[rl].rel = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 766 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 767 ef->reltab[rl].sec = shdr[i].sh_info; 768 error = vn_rdwr(UIO_READ, vp, 769 (void *)ef->reltab[rl].rel, 770 shdr[i].sh_size, shdr[i].sh_offset, 771 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 772 if (error) 773 goto out; 774 if (resid != 0) { 775 error = EINVAL; 776 goto out; 777 } 778 rl++; 779 break; 780 case SHT_RELA: 781 ef->relatab[ra].rela = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 782 ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela); 783 ef->relatab[ra].sec = shdr[i].sh_info; 784 error = vn_rdwr(UIO_READ, vp, 785 (void *)ef->relatab[ra].rela, 786 shdr[i].sh_size, shdr[i].sh_offset, 787 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 788 if (error) 789 goto out; 790 if (resid != 0) { 791 error = EINVAL; 792 goto out; 793 } 794 ra++; 795 break; 796 } 797 } 798 if (pb != ef->nprogtab) 799 panic("lost progbits"); 800 if (rl != ef->nreltab) 801 panic("lost reltab"); 802 if (ra != ef->nrelatab) 803 panic("lost relatab"); 804 if (mapbase != (vm_offset_t) ef->address + mapsize) 805 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)", 806 mapbase, ef->address, mapsize, 807 (vm_offset_t) ef->address + mapsize); 808 809 /* Local intra-module relocations */ 810 link_elf_obj_reloc_local(lf); 811 812 /* Pull in dependencies */ 813 error = linker_load_dependencies(lf); 814 if (error) 815 goto out; 816 817 /* External relocations */ 818 error = relocate_file(lf); 819 if (error) 820 goto out; 821 822 *result = lf; 823 824 out: 825 if (error && lf) 826 linker_file_unload(lf /*, LINKER_UNLOAD_FORCE */); 827 if (hdr) 828 kfree(hdr, M_LINKER); 829 vn_unlock(vp); 830 vn_close(vp, FREAD); 831 832 return error; 833 } 834 835 static void 836 link_elf_obj_unload_file(linker_file_t file) 837 { 838 elf_file_t ef = file->priv; 839 int i; 840 841 if (ef->progtab) { 842 for (i = 0; i < ef->nprogtab; i++) { 843 if (ef->progtab[i].size == 0) 844 continue; 845 if (ef->progtab[i].name == NULL) 846 continue; 847 #if 0 848 if (!strcmp(ef->progtab[i].name, "set_pcpu")) 849 dpcpu_free(ef->progtab[i].addr, 850 ef->progtab[i].size); 851 #ifdef VIMAGE 852 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 853 vnet_data_free(ef->progtab[i].addr, 854 ef->progtab[i].size); 855 #endif 856 #endif 857 } 858 } 859 if (ef->preloaded) { 860 if (ef->reltab) 861 kfree(ef->reltab, M_LINKER); 862 if (ef->relatab) 863 kfree(ef->relatab, M_LINKER); 864 if (ef->progtab) 865 kfree(ef->progtab, M_LINKER); 866 if (ef->ctftab) 867 kfree(ef->ctftab, M_LINKER); 868 if (ef->ctfoff) 869 kfree(ef->ctfoff, M_LINKER); 870 if (ef->typoff) 871 kfree(ef->typoff, M_LINKER); 872 if (file->filename != NULL) 873 preload_delete_name(file->filename); 874 kfree(ef, M_LINKER); 875 /* XXX reclaim module memory? */ 876 return; 877 } 878 879 for (i = 0; i < ef->nreltab; i++) 880 if (ef->reltab[i].rel) 881 kfree(ef->reltab[i].rel, M_LINKER); 882 for (i = 0; i < ef->nrelatab; i++) 883 if (ef->relatab[i].rela) 884 kfree(ef->relatab[i].rela, M_LINKER); 885 if (ef->reltab) 886 kfree(ef->reltab, M_LINKER); 887 if (ef->relatab) 888 kfree(ef->relatab, M_LINKER); 889 if (ef->progtab) 890 kfree(ef->progtab, M_LINKER); 891 892 if (ef->object) { 893 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL) 894 vkernel_module_memory_free((vm_offset_t)ef->address, ef->bytes); 895 #else 896 vm_map_remove(&kernel_map, (vm_offset_t) ef->address, 897 (vm_offset_t) ef->address + 898 (ef->object->size << PAGE_SHIFT)); 899 #endif 900 vm_object_deallocate(ef->object); 901 ef->object = NULL; 902 } 903 if (ef->e_shdr) 904 kfree(ef->e_shdr, M_LINKER); 905 if (ef->ddbsymtab) 906 kfree(ef->ddbsymtab, M_LINKER); 907 if (ef->ddbstrtab) 908 kfree(ef->ddbstrtab, M_LINKER); 909 if (ef->shstrtab) 910 kfree(ef->shstrtab, M_LINKER); 911 if (ef->ctftab) 912 kfree(ef->ctftab, M_LINKER); 913 if (ef->ctfoff) 914 kfree(ef->ctfoff, M_LINKER); 915 if (ef->typoff) 916 kfree(ef->typoff, M_LINKER); 917 kfree(ef, M_LINKER); 918 } 919 920 static const char * 921 symbol_name(elf_file_t ef, Elf_Size r_info) 922 { 923 const Elf_Sym *ref; 924 925 if (ELF_R_SYM(r_info)) { 926 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 927 return ef->ddbstrtab + ref->st_name; 928 } else 929 return NULL; 930 } 931 932 static Elf_Addr 933 findbase(elf_file_t ef, int sec) 934 { 935 int i; 936 Elf_Addr base = 0; 937 938 for (i = 0; i < ef->nprogtab; i++) { 939 if (sec == ef->progtab[i].sec) { 940 base = (Elf_Addr)ef->progtab[i].addr; 941 break; 942 } 943 } 944 return base; 945 } 946 947 static int 948 relocate_file(linker_file_t lf) 949 { 950 elf_file_t ef = lf->priv; 951 const Elf_Rel *rellim; 952 const Elf_Rel *rel; 953 const Elf_Rela *relalim; 954 const Elf_Rela *rela; 955 const char *symname; 956 const Elf_Sym *sym; 957 int i; 958 Elf_Size symidx; 959 Elf_Addr base; 960 961 /* Perform relocations without addend if there are any: */ 962 for (i = 0; i < ef->nreltab; i++) { 963 rel = ef->reltab[i].rel; 964 if (rel == NULL) 965 panic("lost a reltab!"); 966 rellim = rel + ef->reltab[i].nrel; 967 base = findbase(ef, ef->reltab[i].sec); 968 if (base == 0) 969 panic("lost base for reltab"); 970 for ( ; rel < rellim; rel++) { 971 symidx = ELF_R_SYM(rel->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(lf, base, rel, ELF_RELOC_REL, 979 elf_obj_lookup)) { 980 symname = symbol_name(ef, rel->r_info); 981 kprintf("link_elf_obj_obj: symbol %s undefined\n", 982 symname); 983 return ENOENT; 984 } 985 } 986 } 987 988 /* Perform relocations with addend if there are any: */ 989 for (i = 0; i < ef->nrelatab; i++) { 990 rela = ef->relatab[i].rela; 991 if (rela == NULL) 992 panic("lost a relatab!"); 993 relalim = rela + ef->relatab[i].nrela; 994 base = findbase(ef, ef->relatab[i].sec); 995 if (base == 0) 996 panic("lost base for relatab"); 997 for ( ; rela < relalim; rela++) { 998 symidx = ELF_R_SYM(rela->r_info); 999 if (symidx >= ef->ddbsymcnt) 1000 continue; 1001 sym = ef->ddbsymtab + symidx; 1002 /* Local relocs are already done */ 1003 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1004 continue; 1005 if (elf_reloc(lf, base, rela, ELF_RELOC_RELA, 1006 elf_obj_lookup)) { 1007 symname = symbol_name(ef, rela->r_info); 1008 kprintf("link_elf_obj_obj: symbol %s undefined\n", 1009 symname); 1010 return ENOENT; 1011 } 1012 } 1013 } 1014 1015 return 0; 1016 } 1017 1018 static int 1019 link_elf_obj_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1020 { 1021 elf_file_t ef = lf->priv; 1022 const Elf_Sym *symp; 1023 const char *strp; 1024 int i; 1025 1026 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1027 strp = ef->ddbstrtab + symp->st_name; 1028 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1029 *sym = (c_linker_sym_t) symp; 1030 return 0; 1031 } 1032 } 1033 return ENOENT; 1034 } 1035 1036 static int 1037 link_elf_obj_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1038 linker_symval_t *symval) 1039 { 1040 elf_file_t ef = lf->priv; 1041 const Elf_Sym *es = (const Elf_Sym*) sym; 1042 1043 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1044 symval->name = ef->ddbstrtab + es->st_name; 1045 symval->value = (caddr_t)es->st_value; 1046 symval->size = es->st_size; 1047 return 0; 1048 } 1049 return ENOENT; 1050 } 1051 1052 static int 1053 link_elf_obj_search_symbol(linker_file_t lf, caddr_t value, 1054 c_linker_sym_t *sym, long *diffp) 1055 { 1056 elf_file_t ef = lf->priv; 1057 u_long off = (uintptr_t) (void *) value; 1058 u_long diff = off; 1059 u_long st_value; 1060 const Elf_Sym *es; 1061 const Elf_Sym *best = NULL; 1062 int i; 1063 1064 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1065 if (es->st_name == 0) 1066 continue; 1067 st_value = es->st_value; 1068 if (off >= st_value) { 1069 if (off - st_value < diff) { 1070 diff = off - st_value; 1071 best = es; 1072 if (diff == 0) 1073 break; 1074 } else if (off - st_value == diff) { 1075 best = es; 1076 } 1077 } 1078 } 1079 if (best == NULL) 1080 *diffp = off; 1081 else 1082 *diffp = diff; 1083 *sym = (c_linker_sym_t) best; 1084 1085 return 0; 1086 } 1087 1088 /* 1089 * Look up a linker set on an ELF system. 1090 */ 1091 static int 1092 link_elf_obj_lookup_set(linker_file_t lf, const char *name, 1093 void ***startp, void ***stopp, int *countp) 1094 { 1095 elf_file_t ef = lf->priv; 1096 void **start, **stop; 1097 int i, count; 1098 1099 /* Relative to section number */ 1100 for (i = 0; i < ef->nprogtab; i++) { 1101 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1102 strcmp(ef->progtab[i].name + 4, name) == 0) { 1103 start = (void **)ef->progtab[i].addr; 1104 stop = (void **)((char *)ef->progtab[i].addr + 1105 ef->progtab[i].size); 1106 count = stop - start; 1107 if (startp) 1108 *startp = start; 1109 if (stopp) 1110 *stopp = stop; 1111 if (countp) 1112 *countp = count; 1113 return (0); 1114 } 1115 } 1116 return (ESRCH); 1117 } 1118 1119 /* 1120 * Symbol lookup function that can be used when the symbol index is known (ie 1121 * in relocations). It uses the symbol index instead of doing a fully fledged 1122 * hash table based lookup when such is valid. For example for local symbols. 1123 * This is not only more efficient, it's also more correct. It's not always 1124 * the case that the symbol can be found through the hash table. 1125 */ 1126 static int 1127 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *result) 1128 { 1129 elf_file_t ef = lf->priv; 1130 const Elf_Sym *sym; 1131 const char *symbol; 1132 1133 /* Don't even try to lookup the symbol if the index is bogus. */ 1134 if (symidx >= ef->ddbsymcnt) 1135 return (ENOENT); 1136 1137 sym = ef->ddbsymtab + symidx; 1138 1139 /* Quick answer if there is a definition included. */ 1140 if (sym->st_shndx != SHN_UNDEF) { 1141 *result = sym->st_value; 1142 return (0); 1143 } 1144 1145 /* If we get here, then it is undefined and needs a lookup. */ 1146 switch (ELF_ST_BIND(sym->st_info)) { 1147 case STB_LOCAL: 1148 /* Local, but undefined? huh? */ 1149 return (ENOENT); 1150 1151 case STB_GLOBAL: 1152 /* Relative to Data or Function name */ 1153 symbol = ef->ddbstrtab + sym->st_name; 1154 1155 /* Force a lookup failure if the symbol name is bogus. */ 1156 if (*symbol == 0) 1157 return (ENOENT); 1158 return (linker_file_lookup_symbol(lf, symbol, deps, (caddr_t *)result)); 1159 1160 case STB_WEAK: 1161 kprintf("link_elf_obj_obj: Weak symbols not supported\n"); 1162 return (ENOENT); 1163 1164 default: 1165 return (ENOENT); 1166 } 1167 } 1168 1169 static void 1170 link_elf_obj_fix_link_set(elf_file_t ef) 1171 { 1172 static const char startn[] = "__start_"; 1173 static const char stopn[] = "__stop_"; 1174 Elf_Sym *sym; 1175 const char *sym_name, *linkset_name; 1176 Elf_Addr startp, stopp; 1177 Elf_Size symidx; 1178 int start, i; 1179 1180 startp = stopp = 0; 1181 for (symidx = 1 /* zero entry is special */; 1182 symidx < ef->ddbsymcnt; symidx++) { 1183 sym = ef->ddbsymtab + symidx; 1184 if (sym->st_shndx != SHN_UNDEF) 1185 continue; 1186 1187 sym_name = ef->ddbstrtab + sym->st_name; 1188 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1189 start = 1; 1190 linkset_name = sym_name + sizeof(startn) - 1; 1191 } 1192 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1193 start = 0; 1194 linkset_name = sym_name + sizeof(stopn) - 1; 1195 } 1196 else 1197 continue; 1198 1199 for (i = 0; i < ef->nprogtab; i++) { 1200 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1201 startp = (Elf_Addr)ef->progtab[i].addr; 1202 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1203 break; 1204 } 1205 } 1206 if (i == ef->nprogtab) 1207 continue; 1208 1209 sym->st_value = start ? startp : stopp; 1210 sym->st_shndx = i; 1211 } 1212 } 1213 1214 static void 1215 link_elf_obj_reloc_local(linker_file_t lf) 1216 { 1217 elf_file_t ef = lf->priv; 1218 const Elf_Rel *rellim; 1219 const Elf_Rel *rel; 1220 const Elf_Rela *relalim; 1221 const Elf_Rela *rela; 1222 const Elf_Sym *sym; 1223 Elf_Addr base; 1224 int i; 1225 Elf_Size symidx; 1226 1227 link_elf_obj_fix_link_set(ef); 1228 1229 /* Perform relocations without addend if there are any: */ 1230 for (i = 0; i < ef->nreltab; i++) { 1231 rel = ef->reltab[i].rel; 1232 if (rel == NULL) 1233 panic("lost a reltab!"); 1234 rellim = rel + ef->reltab[i].nrel; 1235 base = findbase(ef, ef->reltab[i].sec); 1236 if (base == 0) 1237 panic("lost base for reltab"); 1238 for ( ; rel < rellim; rel++) { 1239 symidx = ELF_R_SYM(rel->r_info); 1240 if (symidx >= ef->ddbsymcnt) 1241 continue; 1242 sym = ef->ddbsymtab + symidx; 1243 /* Only do local relocs */ 1244 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1245 continue; 1246 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1247 elf_obj_lookup); 1248 } 1249 } 1250 1251 /* Perform relocations with addend if there are any: */ 1252 for (i = 0; i < ef->nrelatab; i++) { 1253 rela = ef->relatab[i].rela; 1254 if (rela == NULL) 1255 panic("lost a relatab!"); 1256 relalim = rela + ef->relatab[i].nrela; 1257 base = findbase(ef, ef->relatab[i].sec); 1258 if (base == 0) 1259 panic("lost base for relatab"); 1260 for ( ; rela < relalim; rela++) { 1261 symidx = ELF_R_SYM(rela->r_info); 1262 if (symidx >= ef->ddbsymcnt) 1263 continue; 1264 sym = ef->ddbsymtab + symidx; 1265 /* Only do local relocs */ 1266 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1267 continue; 1268 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1269 elf_obj_lookup); 1270 } 1271 } 1272 } 1273