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 if (shdr[i].sh_size == 0) 519 continue; 520 switch (shdr[i].sh_type) { 521 case SHT_PROGBITS: 522 case SHT_NOBITS: 523 ef->nprogtab++; 524 break; 525 case SHT_SYMTAB: 526 nsym++; 527 symtabindex = i; 528 symstrindex = shdr[i].sh_link; 529 break; 530 case SHT_REL: 531 ef->nreltab++; 532 break; 533 case SHT_RELA: 534 ef->nrelatab++; 535 break; 536 case SHT_STRTAB: 537 break; 538 } 539 } 540 if (ef->nprogtab == 0) { 541 link_elf_obj_error(filename, "file has no contents"); 542 error = ENOEXEC; 543 goto out; 544 } 545 if (nsym != 1) { 546 /* Only allow one symbol table for now */ 547 link_elf_obj_error(filename, "file has no valid symbol table"); 548 error = ENOEXEC; 549 goto out; 550 } 551 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 552 shdr[symstrindex].sh_type != SHT_STRTAB) { 553 link_elf_obj_error(filename, "file has invalid symbol strings"); 554 error = ENOEXEC; 555 goto out; 556 } 557 /* Allocate space for tracking the load chunks */ 558 if (ef->nprogtab != 0) 559 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab), 560 M_LINKER, M_WAITOK | M_ZERO); 561 if (ef->nreltab != 0) 562 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab), 563 M_LINKER, M_WAITOK | M_ZERO); 564 if (ef->nrelatab != 0) 565 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab), 566 M_LINKER, M_WAITOK | M_ZERO); 567 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 568 (ef->nreltab != 0 && ef->reltab == NULL) || 569 (ef->nrelatab != 0 && ef->relatab == NULL)) { 570 error = ENOMEM; 571 goto out; 572 } 573 if (symtabindex == -1) 574 panic("lost symbol table index"); 575 /* Allocate space for and load the symbol table */ 576 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 577 ef->ddbsymtab = kmalloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 578 error = vn_rdwr(UIO_READ, vp, (void *)ef->ddbsymtab, 579 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 580 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 581 if (error) 582 goto out; 583 if (resid != 0) { 584 error = EINVAL; 585 goto out; 586 } 587 if (symstrindex == -1) 588 panic("lost symbol string index"); 589 /* Allocate space for and load the symbol strings */ 590 ef->ddbstrcnt = shdr[symstrindex].sh_size; 591 ef->ddbstrtab = kmalloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 592 error = vn_rdwr(UIO_READ, vp, ef->ddbstrtab, 593 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 594 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 595 if (error) 596 goto out; 597 if (resid != 0) { 598 error = EINVAL; 599 goto out; 600 } 601 /* Do we have a string table for the section names? */ 602 shstrindex = -1; 603 if (hdr->e_shstrndx != 0 && 604 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 605 shstrindex = hdr->e_shstrndx; 606 ef->shstrcnt = shdr[shstrindex].sh_size; 607 ef->shstrtab = kmalloc(shdr[shstrindex].sh_size, M_LINKER, 608 M_WAITOK); 609 error = vn_rdwr(UIO_READ, vp, ef->shstrtab, 610 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 611 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 612 if (error) 613 goto out; 614 if (resid != 0) { 615 error = EINVAL; 616 goto out; 617 } 618 } 619 /* Size up code/data(progbits) and bss(nobits). */ 620 alignmask = 0; 621 for (i = 0; i < hdr->e_shnum; i++) { 622 if (shdr[i].sh_size == 0) 623 continue; 624 switch (shdr[i].sh_type) { 625 case SHT_PROGBITS: 626 case SHT_NOBITS: 627 alignmask = shdr[i].sh_addralign - 1; 628 mapsize += alignmask; 629 mapsize &= ~alignmask; 630 mapsize += shdr[i].sh_size; 631 break; 632 } 633 } 634 635 /* 636 * We know how much space we need for the text/data/bss/etc. This 637 * stuff needs to be in a single chunk so that profiling etc can get 638 * the bounds and gdb can associate offsets with modules 639 */ 640 ef->object = vm_object_allocate(OBJT_DEFAULT, 641 round_page(mapsize) >> PAGE_SHIFT); 642 if (ef->object == NULL) { 643 error = ENOMEM; 644 goto out; 645 } 646 vm_object_hold(ef->object); 647 vm_object_reference_locked(ef->object); 648 ef->address = (caddr_t) vm_map_min(kernel_map); 649 ef->bytes = 0; 650 651 /* 652 * In order to satisfy x86_64's architectural requirements on the 653 * location of code and data in the kernel's address space, request a 654 * mapping that is above the kernel. 655 * 656 * vkernel64's text+data is outside the managed VM space entirely. 657 */ 658 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL) 659 error = vkernel_module_memory_alloc(&mapbase, round_page(mapsize)); 660 vm_object_drop(ef->object); 661 #else 662 mapbase = KERNBASE; 663 error = vm_map_find(kernel_map, ef->object, NULL, 664 0, &mapbase, round_page(mapsize), 665 PAGE_SIZE, TRUE, 666 VM_MAPTYPE_NORMAL, VM_SUBSYS_IMGACT, 667 VM_PROT_ALL, VM_PROT_ALL, FALSE); 668 vm_object_drop(ef->object); 669 if (error) { 670 vm_object_deallocate(ef->object); 671 ef->object = NULL; 672 goto out; 673 } 674 /* Wire the pages */ 675 error = vm_map_wire(kernel_map, mapbase, 676 mapbase + round_page(mapsize), 0); 677 #endif 678 if (error != KERN_SUCCESS) { 679 error = ENOMEM; 680 goto out; 681 } 682 /* Inform the kld system about the situation */ 683 lf->address = ef->address = (caddr_t) mapbase; 684 lf->size = round_page(mapsize); 685 ef->bytes = mapsize; 686 687 /* 688 * Now load code/data(progbits), zero bss(nobits), allocate space for 689 * and load relocs 690 */ 691 pb = 0; 692 rl = 0; 693 ra = 0; 694 alignmask = 0; 695 for (i = 0; i < hdr->e_shnum; i++) { 696 if (shdr[i].sh_size == 0) 697 continue; 698 switch (shdr[i].sh_type) { 699 case SHT_PROGBITS: 700 case SHT_NOBITS: 701 alignmask = shdr[i].sh_addralign - 1; 702 mapbase += alignmask; 703 mapbase &= ~alignmask; 704 if (ef->shstrtab && shdr[i].sh_name != 0) 705 ef->progtab[pb].name = 706 ef->shstrtab + shdr[i].sh_name; 707 else if (shdr[i].sh_type == SHT_PROGBITS) 708 ef->progtab[pb].name = "<<PROGBITS>>"; 709 else 710 ef->progtab[pb].name = "<<NOBITS>>"; 711 #if 0 712 if (ef->progtab[pb].name != NULL && 713 !strcmp(ef->progtab[pb].name, "set_pcpu")) 714 ef->progtab[pb].addr = 715 dpcpu_alloc(shdr[i].sh_size); 716 #ifdef VIMAGE 717 else if (ef->progtab[pb].name != NULL && 718 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 719 ef->progtab[pb].addr = 720 vnet_data_alloc(shdr[i].sh_size); 721 #endif 722 else 723 #endif 724 ef->progtab[pb].addr = 725 (void *)(uintptr_t) mapbase; 726 if (ef->progtab[pb].addr == NULL) { 727 error = ENOSPC; 728 goto out; 729 } 730 ef->progtab[pb].size = shdr[i].sh_size; 731 ef->progtab[pb].sec = i; 732 if (shdr[i].sh_type == SHT_PROGBITS) { 733 error = vn_rdwr(UIO_READ, vp, 734 ef->progtab[pb].addr, 735 shdr[i].sh_size, shdr[i].sh_offset, 736 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 737 &resid); 738 if (error) 739 goto out; 740 if (resid != 0) { 741 error = EINVAL; 742 goto out; 743 } 744 #if 0 745 /* Initialize the per-cpu or vnet area. */ 746 if (ef->progtab[pb].addr != (void *)mapbase && 747 !strcmp(ef->progtab[pb].name, "set_pcpu")) 748 dpcpu_copy(ef->progtab[pb].addr, 749 shdr[i].sh_size); 750 #ifdef VIMAGE 751 else if (ef->progtab[pb].addr != 752 (void *)mapbase && 753 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 754 vnet_data_copy(ef->progtab[pb].addr, 755 shdr[i].sh_size); 756 #endif 757 #endif 758 } else 759 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 760 761 /* Update all symbol values with the offset. */ 762 for (j = 0; j < ef->ddbsymcnt; j++) { 763 es = &ef->ddbsymtab[j]; 764 if (es->st_shndx != i) 765 continue; 766 es->st_value += (Elf_Addr) ef->progtab[pb].addr; 767 } 768 mapbase += shdr[i].sh_size; 769 pb++; 770 break; 771 case SHT_REL: 772 ef->reltab[rl].rel = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 773 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 774 ef->reltab[rl].sec = shdr[i].sh_info; 775 error = vn_rdwr(UIO_READ, vp, 776 (void *)ef->reltab[rl].rel, 777 shdr[i].sh_size, shdr[i].sh_offset, 778 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 779 if (error) 780 goto out; 781 if (resid != 0) { 782 error = EINVAL; 783 goto out; 784 } 785 rl++; 786 break; 787 case SHT_RELA: 788 ef->relatab[ra].rela = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 789 ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela); 790 ef->relatab[ra].sec = shdr[i].sh_info; 791 error = vn_rdwr(UIO_READ, vp, 792 (void *)ef->relatab[ra].rela, 793 shdr[i].sh_size, shdr[i].sh_offset, 794 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid); 795 if (error) 796 goto out; 797 if (resid != 0) { 798 error = EINVAL; 799 goto out; 800 } 801 ra++; 802 break; 803 } 804 } 805 if (pb != ef->nprogtab) 806 panic("lost progbits"); 807 if (rl != ef->nreltab) 808 panic("lost reltab"); 809 if (ra != ef->nrelatab) 810 panic("lost relatab"); 811 if (mapbase != (vm_offset_t) ef->address + mapsize) 812 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)", 813 mapbase, ef->address, mapsize, 814 (vm_offset_t) ef->address + mapsize); 815 816 /* Local intra-module relocations */ 817 link_elf_obj_reloc_local(lf); 818 819 /* Pull in dependencies */ 820 error = linker_load_dependencies(lf); 821 if (error) 822 goto out; 823 824 /* External relocations */ 825 error = relocate_file(lf); 826 if (error) 827 goto out; 828 829 *result = lf; 830 831 out: 832 if (error && lf) 833 linker_file_unload(lf /*, LINKER_UNLOAD_FORCE */); 834 if (hdr) 835 kfree(hdr, M_LINKER); 836 vn_unlock(vp); 837 vn_close(vp, FREAD, NULL); 838 839 return error; 840 } 841 842 static void 843 link_elf_obj_unload_file(linker_file_t file) 844 { 845 elf_file_t ef = file->priv; 846 int i; 847 848 if (ef->progtab) { 849 for (i = 0; i < ef->nprogtab; i++) { 850 if (ef->progtab[i].size == 0) 851 continue; 852 if (ef->progtab[i].name == NULL) 853 continue; 854 #if 0 855 if (!strcmp(ef->progtab[i].name, "set_pcpu")) 856 dpcpu_free(ef->progtab[i].addr, 857 ef->progtab[i].size); 858 #ifdef VIMAGE 859 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 860 vnet_data_free(ef->progtab[i].addr, 861 ef->progtab[i].size); 862 #endif 863 #endif 864 } 865 } 866 if (ef->preloaded) { 867 if (ef->reltab) 868 kfree(ef->reltab, M_LINKER); 869 if (ef->relatab) 870 kfree(ef->relatab, M_LINKER); 871 if (ef->progtab) 872 kfree(ef->progtab, M_LINKER); 873 if (ef->ctftab) 874 kfree(ef->ctftab, M_LINKER); 875 if (ef->ctfoff) 876 kfree(ef->ctfoff, M_LINKER); 877 if (ef->typoff) 878 kfree(ef->typoff, M_LINKER); 879 if (file->filename != NULL) 880 preload_delete_name(file->filename); 881 kfree(ef, M_LINKER); 882 /* XXX reclaim module memory? */ 883 return; 884 } 885 886 for (i = 0; i < ef->nreltab; i++) 887 if (ef->reltab[i].rel) 888 kfree(ef->reltab[i].rel, M_LINKER); 889 for (i = 0; i < ef->nrelatab; i++) 890 if (ef->relatab[i].rela) 891 kfree(ef->relatab[i].rela, M_LINKER); 892 if (ef->reltab) 893 kfree(ef->reltab, M_LINKER); 894 if (ef->relatab) 895 kfree(ef->relatab, M_LINKER); 896 if (ef->progtab) 897 kfree(ef->progtab, M_LINKER); 898 899 if (ef->object) { 900 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL) 901 vkernel_module_memory_free((vm_offset_t)ef->address, ef->bytes); 902 #else 903 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 904 (vm_offset_t) ef->address + 905 (ef->object->size << PAGE_SHIFT)); 906 #endif 907 vm_object_deallocate(ef->object); 908 ef->object = NULL; 909 } 910 if (ef->e_shdr) 911 kfree(ef->e_shdr, M_LINKER); 912 if (ef->ddbsymtab) 913 kfree(ef->ddbsymtab, M_LINKER); 914 if (ef->ddbstrtab) 915 kfree(ef->ddbstrtab, M_LINKER); 916 if (ef->shstrtab) 917 kfree(ef->shstrtab, M_LINKER); 918 if (ef->ctftab) 919 kfree(ef->ctftab, M_LINKER); 920 if (ef->ctfoff) 921 kfree(ef->ctfoff, M_LINKER); 922 if (ef->typoff) 923 kfree(ef->typoff, M_LINKER); 924 kfree(ef, M_LINKER); 925 } 926 927 static const char * 928 symbol_name(elf_file_t ef, Elf_Size r_info) 929 { 930 const Elf_Sym *ref; 931 932 if (ELF_R_SYM(r_info)) { 933 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 934 return ef->ddbstrtab + ref->st_name; 935 } else 936 return NULL; 937 } 938 939 static Elf_Addr 940 findbase(elf_file_t ef, int sec) 941 { 942 int i; 943 Elf_Addr base = 0; 944 945 for (i = 0; i < ef->nprogtab; i++) { 946 if (sec == ef->progtab[i].sec) { 947 base = (Elf_Addr)ef->progtab[i].addr; 948 break; 949 } 950 } 951 return base; 952 } 953 954 static int 955 relocate_file(linker_file_t lf) 956 { 957 elf_file_t ef = lf->priv; 958 const Elf_Rel *rellim; 959 const Elf_Rel *rel; 960 const Elf_Rela *relalim; 961 const Elf_Rela *rela; 962 const char *symname; 963 const Elf_Sym *sym; 964 int i; 965 Elf_Size symidx; 966 Elf_Addr base; 967 968 /* Perform relocations without addend if there are any: */ 969 for (i = 0; i < ef->nreltab; i++) { 970 rel = ef->reltab[i].rel; 971 if (rel == NULL) 972 panic("lost a reltab!"); 973 rellim = rel + ef->reltab[i].nrel; 974 base = findbase(ef, ef->reltab[i].sec); 975 if (base == 0) 976 panic("lost base for reltab"); 977 for ( ; rel < rellim; rel++) { 978 symidx = ELF_R_SYM(rel->r_info); 979 if (symidx >= ef->ddbsymcnt) 980 continue; 981 sym = ef->ddbsymtab + symidx; 982 /* Local relocs are already done */ 983 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 984 continue; 985 if (elf_reloc(lf, base, rel, ELF_RELOC_REL, 986 elf_obj_lookup)) { 987 symname = symbol_name(ef, rel->r_info); 988 kprintf("link_elf_obj_obj: symbol %s undefined\n", 989 symname); 990 return ENOENT; 991 } 992 } 993 } 994 995 /* Perform relocations with addend if there are any: */ 996 for (i = 0; i < ef->nrelatab; i++) { 997 rela = ef->relatab[i].rela; 998 if (rela == NULL) 999 panic("lost a relatab!"); 1000 relalim = rela + ef->relatab[i].nrela; 1001 base = findbase(ef, ef->relatab[i].sec); 1002 if (base == 0) 1003 panic("lost base for relatab"); 1004 for ( ; rela < relalim; rela++) { 1005 symidx = ELF_R_SYM(rela->r_info); 1006 if (symidx >= ef->ddbsymcnt) 1007 continue; 1008 sym = ef->ddbsymtab + symidx; 1009 /* Local relocs are already done */ 1010 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1011 continue; 1012 if (elf_reloc(lf, base, rela, ELF_RELOC_RELA, 1013 elf_obj_lookup)) { 1014 symname = symbol_name(ef, rela->r_info); 1015 kprintf("link_elf_obj_obj: symbol %s undefined\n", 1016 symname); 1017 return ENOENT; 1018 } 1019 } 1020 } 1021 1022 return 0; 1023 } 1024 1025 static int 1026 link_elf_obj_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1027 { 1028 elf_file_t ef = lf->priv; 1029 const Elf_Sym *symp; 1030 const char *strp; 1031 int i; 1032 1033 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1034 strp = ef->ddbstrtab + symp->st_name; 1035 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1036 *sym = (c_linker_sym_t) symp; 1037 return 0; 1038 } 1039 } 1040 return ENOENT; 1041 } 1042 1043 static int 1044 link_elf_obj_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1045 linker_symval_t *symval) 1046 { 1047 elf_file_t ef = lf->priv; 1048 const Elf_Sym *es = (const Elf_Sym*) sym; 1049 1050 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1051 symval->name = ef->ddbstrtab + es->st_name; 1052 symval->value = (caddr_t)es->st_value; 1053 symval->size = es->st_size; 1054 return 0; 1055 } 1056 return ENOENT; 1057 } 1058 1059 static int 1060 link_elf_obj_search_symbol(linker_file_t lf, caddr_t value, 1061 c_linker_sym_t *sym, long *diffp) 1062 { 1063 elf_file_t ef = lf->priv; 1064 u_long off = (uintptr_t) (void *) value; 1065 u_long diff = off; 1066 u_long st_value; 1067 const Elf_Sym *es; 1068 const Elf_Sym *best = NULL; 1069 int i; 1070 1071 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1072 if (es->st_name == 0) 1073 continue; 1074 st_value = es->st_value; 1075 if (off >= st_value) { 1076 if (off - st_value < diff) { 1077 diff = off - st_value; 1078 best = es; 1079 if (diff == 0) 1080 break; 1081 } else if (off - st_value == diff) { 1082 best = es; 1083 } 1084 } 1085 } 1086 if (best == NULL) 1087 *diffp = off; 1088 else 1089 *diffp = diff; 1090 *sym = (c_linker_sym_t) best; 1091 1092 return 0; 1093 } 1094 1095 /* 1096 * Look up a linker set on an ELF system. 1097 */ 1098 static int 1099 link_elf_obj_lookup_set(linker_file_t lf, const char *name, 1100 void ***startp, void ***stopp, int *countp) 1101 { 1102 elf_file_t ef = lf->priv; 1103 void **start, **stop; 1104 int i, count; 1105 1106 /* Relative to section number */ 1107 for (i = 0; i < ef->nprogtab; i++) { 1108 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1109 strcmp(ef->progtab[i].name + 4, name) == 0) { 1110 start = (void **)ef->progtab[i].addr; 1111 stop = (void **)((char *)ef->progtab[i].addr + 1112 ef->progtab[i].size); 1113 count = stop - start; 1114 if (startp) 1115 *startp = start; 1116 if (stopp) 1117 *stopp = stop; 1118 if (countp) 1119 *countp = count; 1120 return (0); 1121 } 1122 } 1123 return (ESRCH); 1124 } 1125 1126 /* 1127 * Symbol lookup function that can be used when the symbol index is known (ie 1128 * in relocations). It uses the symbol index instead of doing a fully fledged 1129 * hash table based lookup when such is valid. For example for local symbols. 1130 * This is not only more efficient, it's also more correct. It's not always 1131 * the case that the symbol can be found through the hash table. 1132 */ 1133 static int 1134 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *result) 1135 { 1136 elf_file_t ef = lf->priv; 1137 const Elf_Sym *sym; 1138 const char *symbol; 1139 1140 /* Don't even try to lookup the symbol if the index is bogus. */ 1141 if (symidx >= ef->ddbsymcnt) 1142 return (ENOENT); 1143 1144 sym = ef->ddbsymtab + symidx; 1145 1146 /* Quick answer if there is a definition included. */ 1147 if (sym->st_shndx != SHN_UNDEF) { 1148 *result = sym->st_value; 1149 return (0); 1150 } 1151 1152 /* If we get here, then it is undefined and needs a lookup. */ 1153 switch (ELF_ST_BIND(sym->st_info)) { 1154 case STB_LOCAL: 1155 /* Local, but undefined? huh? */ 1156 return (ENOENT); 1157 1158 case STB_GLOBAL: 1159 /* Relative to Data or Function name */ 1160 symbol = ef->ddbstrtab + sym->st_name; 1161 1162 /* Force a lookup failure if the symbol name is bogus. */ 1163 if (*symbol == 0) 1164 return (ENOENT); 1165 return (linker_file_lookup_symbol(lf, symbol, deps, (caddr_t *)result)); 1166 1167 case STB_WEAK: 1168 kprintf("link_elf_obj_obj: Weak symbols not supported\n"); 1169 return (ENOENT); 1170 1171 default: 1172 return (ENOENT); 1173 } 1174 } 1175 1176 static void 1177 link_elf_obj_fix_link_set(elf_file_t ef) 1178 { 1179 static const char startn[] = "__start_"; 1180 static const char stopn[] = "__stop_"; 1181 Elf_Sym *sym; 1182 const char *sym_name, *linkset_name; 1183 Elf_Addr startp, stopp; 1184 Elf_Size symidx; 1185 int start, i; 1186 1187 startp = stopp = 0; 1188 for (symidx = 1 /* zero entry is special */; 1189 symidx < ef->ddbsymcnt; symidx++) { 1190 sym = ef->ddbsymtab + symidx; 1191 if (sym->st_shndx != SHN_UNDEF) 1192 continue; 1193 1194 sym_name = ef->ddbstrtab + sym->st_name; 1195 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1196 start = 1; 1197 linkset_name = sym_name + sizeof(startn) - 1; 1198 } 1199 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1200 start = 0; 1201 linkset_name = sym_name + sizeof(stopn) - 1; 1202 } 1203 else 1204 continue; 1205 1206 for (i = 0; i < ef->nprogtab; i++) { 1207 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1208 startp = (Elf_Addr)ef->progtab[i].addr; 1209 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1210 break; 1211 } 1212 } 1213 if (i == ef->nprogtab) 1214 continue; 1215 1216 sym->st_value = start ? startp : stopp; 1217 sym->st_shndx = i; 1218 } 1219 } 1220 1221 static void 1222 link_elf_obj_reloc_local(linker_file_t lf) 1223 { 1224 elf_file_t ef = lf->priv; 1225 const Elf_Rel *rellim; 1226 const Elf_Rel *rel; 1227 const Elf_Rela *relalim; 1228 const Elf_Rela *rela; 1229 const Elf_Sym *sym; 1230 Elf_Addr base; 1231 int i; 1232 Elf_Size symidx; 1233 1234 link_elf_obj_fix_link_set(ef); 1235 1236 /* Perform relocations without addend if there are any: */ 1237 for (i = 0; i < ef->nreltab; i++) { 1238 rel = ef->reltab[i].rel; 1239 if (rel == NULL) 1240 panic("lost a reltab!"); 1241 rellim = rel + ef->reltab[i].nrel; 1242 base = findbase(ef, ef->reltab[i].sec); 1243 if (base == 0) 1244 panic("lost base for reltab"); 1245 for ( ; rel < rellim; rel++) { 1246 symidx = ELF_R_SYM(rel->r_info); 1247 if (symidx >= ef->ddbsymcnt) 1248 continue; 1249 sym = ef->ddbsymtab + symidx; 1250 /* Only do local relocs */ 1251 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1252 continue; 1253 elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1254 elf_obj_lookup); 1255 } 1256 } 1257 1258 /* Perform relocations with addend if there are any: */ 1259 for (i = 0; i < ef->nrelatab; i++) { 1260 rela = ef->relatab[i].rela; 1261 if (rela == NULL) 1262 panic("lost a relatab!"); 1263 relalim = rela + ef->relatab[i].nrela; 1264 base = findbase(ef, ef->relatab[i].sec); 1265 if (base == 0) 1266 panic("lost base for relatab"); 1267 for ( ; rela < relalim; rela++) { 1268 symidx = ELF_R_SYM(rela->r_info); 1269 if (symidx >= ef->ddbsymcnt) 1270 continue; 1271 sym = ef->ddbsymtab + symidx; 1272 /* Only do local relocs */ 1273 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1274 continue; 1275 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1276 elf_obj_lookup); 1277 } 1278 } 1279 } 1280