1 /*- 2 * Copyright (c) 1998-2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_ddb.h" 31 #include "opt_gdb.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #ifdef GPROF 36 #include <sys/gmon.h> 37 #endif 38 #include <sys/kernel.h> 39 #include <sys/lock.h> 40 #include <sys/malloc.h> 41 #include <sys/mutex.h> 42 #include <sys/mount.h> 43 #include <sys/pcpu.h> 44 #include <sys/proc.h> 45 #include <sys/namei.h> 46 #include <sys/fcntl.h> 47 #include <sys/vnode.h> 48 #include <sys/linker.h> 49 50 #include <machine/elf.h> 51 52 #include <net/vnet.h> 53 54 #include <security/mac/mac_framework.h> 55 56 #include <vm/vm.h> 57 #include <vm/vm_param.h> 58 #ifdef SPARSE_MAPPING 59 #include <vm/vm_object.h> 60 #include <vm/vm_kern.h> 61 #include <vm/vm_extern.h> 62 #endif 63 #include <vm/pmap.h> 64 #include <vm/vm_map.h> 65 66 #include <sys/link_elf.h> 67 68 #ifdef DDB_CTF 69 #include <net/zlib.h> 70 #endif 71 72 #include "linker_if.h" 73 74 #define MAXSEGS 4 75 76 typedef struct elf_file { 77 struct linker_file lf; /* Common fields */ 78 int preloaded; /* Was file pre-loaded */ 79 caddr_t address; /* Relocation address */ 80 #ifdef SPARSE_MAPPING 81 vm_object_t object; /* VM object to hold file pages */ 82 #endif 83 Elf_Dyn *dynamic; /* Symbol table etc. */ 84 Elf_Hashelt nbuckets; /* DT_HASH info */ 85 Elf_Hashelt nchains; 86 const Elf_Hashelt *buckets; 87 const Elf_Hashelt *chains; 88 caddr_t hash; 89 caddr_t strtab; /* DT_STRTAB */ 90 int strsz; /* DT_STRSZ */ 91 const Elf_Sym *symtab; /* DT_SYMTAB */ 92 Elf_Addr *got; /* DT_PLTGOT */ 93 const Elf_Rel *pltrel; /* DT_JMPREL */ 94 int pltrelsize; /* DT_PLTRELSZ */ 95 const Elf_Rela *pltrela; /* DT_JMPREL */ 96 int pltrelasize; /* DT_PLTRELSZ */ 97 const Elf_Rel *rel; /* DT_REL */ 98 int relsize; /* DT_RELSZ */ 99 const Elf_Rela *rela; /* DT_RELA */ 100 int relasize; /* DT_RELASZ */ 101 caddr_t modptr; 102 const Elf_Sym *ddbsymtab; /* The symbol table we are using */ 103 long ddbsymcnt; /* Number of symbols */ 104 caddr_t ddbstrtab; /* String table */ 105 long ddbstrcnt; /* number of bytes in string table */ 106 caddr_t symbase; /* malloc'ed symbold base */ 107 caddr_t strbase; /* malloc'ed string base */ 108 caddr_t ctftab; /* CTF table */ 109 long ctfcnt; /* number of bytes in CTF table */ 110 caddr_t ctfoff; /* CTF offset table */ 111 caddr_t typoff; /* Type offset table */ 112 long typlen; /* Number of type entries. */ 113 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */ 114 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */ 115 Elf_Addr pcpu_base; /* Relocated pcpu set address. */ 116 #ifdef VIMAGE 117 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */ 118 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */ 119 Elf_Addr vnet_base; /* Relocated vnet set address. */ 120 #endif 121 #ifdef GDB 122 struct link_map gdb; /* hooks for gdb */ 123 #endif 124 } *elf_file_t; 125 126 struct elf_set { 127 Elf_Addr es_start; 128 Elf_Addr es_stop; 129 Elf_Addr es_base; 130 TAILQ_ENTRY(elf_set) es_link; 131 }; 132 133 TAILQ_HEAD(elf_set_head, elf_set); 134 135 #include <kern/kern_ctf.c> 136 137 static int link_elf_link_common_finish(linker_file_t); 138 static int link_elf_link_preload(linker_class_t cls, 139 const char *, linker_file_t *); 140 static int link_elf_link_preload_finish(linker_file_t); 141 static int link_elf_load_file(linker_class_t, const char *, 142 linker_file_t *); 143 static int link_elf_lookup_symbol(linker_file_t, const char *, 144 c_linker_sym_t *); 145 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 146 linker_symval_t *); 147 static int link_elf_search_symbol(linker_file_t, caddr_t, 148 c_linker_sym_t *, long *); 149 150 static void link_elf_unload_file(linker_file_t); 151 static void link_elf_unload_preload(linker_file_t); 152 static int link_elf_lookup_set(linker_file_t, const char *, 153 void ***, void ***, int *); 154 static int link_elf_each_function_name(linker_file_t, 155 int (*)(const char *, void *), void *); 156 static int link_elf_each_function_nameval(linker_file_t, 157 linker_function_nameval_callback_t, void *); 158 static void link_elf_reloc_local(linker_file_t); 159 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 160 static long link_elf_strtab_get(linker_file_t, caddr_t *); 161 static Elf_Addr elf_lookup(linker_file_t, Elf_Size, int); 162 163 static kobj_method_t link_elf_methods[] = { 164 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 165 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 166 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 167 KOBJMETHOD(linker_unload, link_elf_unload_file), 168 KOBJMETHOD(linker_load_file, link_elf_load_file), 169 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 170 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 171 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 172 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 173 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 174 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 175 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 176 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 177 { 0, 0 } 178 }; 179 180 static struct linker_class link_elf_class = { 181 #if ELF_TARG_CLASS == ELFCLASS32 182 "elf32", 183 #else 184 "elf64", 185 #endif 186 link_elf_methods, sizeof(struct elf_file) 187 }; 188 189 static int parse_dynamic(elf_file_t); 190 static int relocate_file(elf_file_t); 191 static int link_elf_preload_parse_symbols(elf_file_t); 192 193 static struct elf_set_head set_pcpu_list; 194 #ifdef VIMAGE 195 static struct elf_set_head set_vnet_list; 196 #endif 197 198 static void 199 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base) 200 { 201 struct elf_set *set, *iter; 202 203 set = malloc(sizeof(*set), M_LINKER, M_WAITOK); 204 set->es_start = start; 205 set->es_stop = stop; 206 set->es_base = base; 207 208 TAILQ_FOREACH(iter, list, es_link) { 209 210 KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) || 211 (set->es_start > iter->es_start && set->es_stop > iter->es_stop), 212 ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx", 213 (uintmax_t)set->es_start, (uintmax_t)set->es_stop, 214 (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop)); 215 216 if (iter->es_start > set->es_start) { 217 TAILQ_INSERT_BEFORE(iter, set, es_link); 218 break; 219 } 220 } 221 222 if (iter == NULL) 223 TAILQ_INSERT_TAIL(list, set, es_link); 224 } 225 226 static int 227 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base) 228 { 229 struct elf_set *set; 230 231 TAILQ_FOREACH(set, list, es_link) { 232 if (addr < set->es_start) 233 return (0); 234 if (addr < set->es_stop) { 235 *start = set->es_start; 236 *base = set->es_base; 237 return (1); 238 } 239 } 240 241 return (0); 242 } 243 244 static void 245 elf_set_delete(struct elf_set_head *list, Elf_Addr start) 246 { 247 struct elf_set *set; 248 249 TAILQ_FOREACH(set, list, es_link) { 250 if (start < set->es_start) 251 break; 252 if (start == set->es_start) { 253 TAILQ_REMOVE(list, set, es_link); 254 free(set, M_LINKER); 255 return; 256 } 257 } 258 KASSERT(0, ("deleting unknown linker set (start = 0x%jx)", 259 (uintmax_t)start)); 260 } 261 262 #ifdef GDB 263 static void r_debug_state(struct r_debug *, struct link_map *); 264 265 /* 266 * A list of loaded modules for GDB to use for loading symbols. 267 */ 268 struct r_debug r_debug; 269 270 #define GDB_STATE(s) do { \ 271 r_debug.r_state = s; r_debug_state(NULL, NULL); \ 272 } while (0) 273 274 /* 275 * Function for the debugger to set a breakpoint on to gain control. 276 */ 277 static void 278 r_debug_state(struct r_debug *dummy_one __unused, 279 struct link_map *dummy_two __unused) 280 { 281 } 282 283 static void 284 link_elf_add_gdb(struct link_map *l) 285 { 286 struct link_map *prev; 287 288 l->l_next = NULL; 289 290 if (r_debug.r_map == NULL) { 291 /* Add first. */ 292 l->l_prev = NULL; 293 r_debug.r_map = l; 294 } else { 295 /* Append to list. */ 296 for (prev = r_debug.r_map; 297 prev->l_next != NULL; 298 prev = prev->l_next) 299 ; 300 l->l_prev = prev; 301 prev->l_next = l; 302 } 303 } 304 305 static void 306 link_elf_delete_gdb(struct link_map *l) 307 { 308 if (l->l_prev == NULL) { 309 /* Remove first. */ 310 if ((r_debug.r_map = l->l_next) != NULL) 311 l->l_next->l_prev = NULL; 312 } else { 313 /* Remove any but first. */ 314 if ((l->l_prev->l_next = l->l_next) != NULL) 315 l->l_next->l_prev = l->l_prev; 316 } 317 } 318 #endif /* GDB */ 319 320 /* 321 * The kernel symbol table starts here. 322 */ 323 extern struct _dynamic _DYNAMIC; 324 325 static void 326 link_elf_error(const char *filename, const char *s) 327 { 328 if (filename == NULL) 329 printf("kldload: %s\n", s); 330 else 331 printf("kldload: %s: %s\n", filename, s); 332 } 333 334 static void 335 link_elf_invoke_ctors(caddr_t addr, size_t size) 336 { 337 void (**ctor)(void); 338 size_t i, cnt; 339 340 if (addr == NULL || size == 0) 341 return; 342 cnt = size / sizeof(*ctor); 343 ctor = (void *)addr; 344 for (i = 0; i < cnt; i++) { 345 if (ctor[i] != NULL) 346 (*ctor[i])(); 347 } 348 } 349 350 /* 351 * Actions performed after linking/loading both the preloaded kernel and any 352 * modules; whether preloaded or dynamicly loaded. 353 */ 354 static int 355 link_elf_link_common_finish(linker_file_t lf) 356 { 357 #ifdef GDB 358 elf_file_t ef = (elf_file_t)lf; 359 char *newfilename; 360 #endif 361 int error; 362 363 /* Notify MD code that a module is being loaded. */ 364 error = elf_cpu_load_file(lf); 365 if (error != 0) 366 return (error); 367 368 #ifdef GDB 369 GDB_STATE(RT_ADD); 370 ef->gdb.l_addr = lf->address; 371 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 372 strcpy(newfilename, lf->filename); 373 ef->gdb.l_name = newfilename; 374 ef->gdb.l_ld = ef->dynamic; 375 link_elf_add_gdb(&ef->gdb); 376 GDB_STATE(RT_CONSISTENT); 377 #endif 378 379 /* Invoke .ctors */ 380 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 381 return (0); 382 } 383 384 static void 385 link_elf_init(void* arg) 386 { 387 Elf_Dyn *dp; 388 Elf_Addr *ctors_addrp; 389 Elf_Size *ctors_sizep; 390 caddr_t modptr, baseptr, sizeptr; 391 elf_file_t ef; 392 char *modname; 393 394 linker_add_class(&link_elf_class); 395 396 dp = (Elf_Dyn *)&_DYNAMIC; 397 modname = NULL; 398 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 399 if (modptr == NULL) 400 modptr = preload_search_by_type("elf kernel"); 401 if (modptr != NULL) 402 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 403 if (modname == NULL) 404 modname = "kernel"; 405 linker_kernel_file = linker_make_file(modname, &link_elf_class); 406 if (linker_kernel_file == NULL) 407 panic("%s: Can't create linker structures for kernel", 408 __func__); 409 410 ef = (elf_file_t) linker_kernel_file; 411 ef->preloaded = 1; 412 ef->address = 0; 413 #ifdef SPARSE_MAPPING 414 ef->object = 0; 415 #endif 416 ef->dynamic = dp; 417 418 if (dp != NULL) 419 parse_dynamic(ef); 420 linker_kernel_file->address = (caddr_t) KERNBASE; 421 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 422 423 if (modptr != NULL) { 424 ef->modptr = modptr; 425 baseptr = preload_search_info(modptr, MODINFO_ADDR); 426 if (baseptr != NULL) 427 linker_kernel_file->address = *(caddr_t *)baseptr; 428 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 429 if (sizeptr != NULL) 430 linker_kernel_file->size = *(size_t *)sizeptr; 431 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 432 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 433 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 434 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 435 if (ctors_addrp != NULL && ctors_sizep != NULL) { 436 linker_kernel_file->ctors_addr = ef->address + 437 *ctors_addrp; 438 linker_kernel_file->ctors_size = *ctors_sizep; 439 } 440 } 441 (void)link_elf_preload_parse_symbols(ef); 442 443 #ifdef GDB 444 r_debug.r_map = NULL; 445 r_debug.r_brk = r_debug_state; 446 r_debug.r_state = RT_CONSISTENT; 447 #endif 448 449 (void)link_elf_link_common_finish(linker_kernel_file); 450 linker_kernel_file->flags |= LINKER_FILE_LINKED; 451 TAILQ_INIT(&set_pcpu_list); 452 #ifdef VIMAGE 453 TAILQ_INIT(&set_vnet_list); 454 #endif 455 } 456 457 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0); 458 459 static int 460 link_elf_preload_parse_symbols(elf_file_t ef) 461 { 462 caddr_t pointer; 463 caddr_t ssym, esym, base; 464 caddr_t strtab; 465 int strcnt; 466 Elf_Sym *symtab; 467 int symcnt; 468 469 if (ef->modptr == NULL) 470 return (0); 471 pointer = preload_search_info(ef->modptr, 472 MODINFO_METADATA | MODINFOMD_SSYM); 473 if (pointer == NULL) 474 return (0); 475 ssym = *(caddr_t *)pointer; 476 pointer = preload_search_info(ef->modptr, 477 MODINFO_METADATA | MODINFOMD_ESYM); 478 if (pointer == NULL) 479 return (0); 480 esym = *(caddr_t *)pointer; 481 482 base = ssym; 483 484 symcnt = *(long *)base; 485 base += sizeof(long); 486 symtab = (Elf_Sym *)base; 487 base += roundup(symcnt, sizeof(long)); 488 489 if (base > esym || base < ssym) { 490 printf("Symbols are corrupt!\n"); 491 return (EINVAL); 492 } 493 494 strcnt = *(long *)base; 495 base += sizeof(long); 496 strtab = base; 497 base += roundup(strcnt, sizeof(long)); 498 499 if (base > esym || base < ssym) { 500 printf("Symbols are corrupt!\n"); 501 return (EINVAL); 502 } 503 504 ef->ddbsymtab = symtab; 505 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 506 ef->ddbstrtab = strtab; 507 ef->ddbstrcnt = strcnt; 508 509 return (0); 510 } 511 512 static int 513 parse_dynamic(elf_file_t ef) 514 { 515 Elf_Dyn *dp; 516 int plttype = DT_REL; 517 518 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 519 switch (dp->d_tag) { 520 case DT_HASH: 521 { 522 /* From src/libexec/rtld-elf/rtld.c */ 523 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 524 (ef->address + dp->d_un.d_ptr); 525 ef->nbuckets = hashtab[0]; 526 ef->nchains = hashtab[1]; 527 ef->buckets = hashtab + 2; 528 ef->chains = ef->buckets + ef->nbuckets; 529 break; 530 } 531 case DT_STRTAB: 532 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 533 break; 534 case DT_STRSZ: 535 ef->strsz = dp->d_un.d_val; 536 break; 537 case DT_SYMTAB: 538 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 539 break; 540 case DT_SYMENT: 541 if (dp->d_un.d_val != sizeof(Elf_Sym)) 542 return (ENOEXEC); 543 break; 544 case DT_PLTGOT: 545 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 546 break; 547 case DT_REL: 548 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 549 break; 550 case DT_RELSZ: 551 ef->relsize = dp->d_un.d_val; 552 break; 553 case DT_RELENT: 554 if (dp->d_un.d_val != sizeof(Elf_Rel)) 555 return (ENOEXEC); 556 break; 557 case DT_JMPREL: 558 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 559 break; 560 case DT_PLTRELSZ: 561 ef->pltrelsize = dp->d_un.d_val; 562 break; 563 case DT_RELA: 564 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 565 break; 566 case DT_RELASZ: 567 ef->relasize = dp->d_un.d_val; 568 break; 569 case DT_RELAENT: 570 if (dp->d_un.d_val != sizeof(Elf_Rela)) 571 return (ENOEXEC); 572 break; 573 case DT_PLTREL: 574 plttype = dp->d_un.d_val; 575 if (plttype != DT_REL && plttype != DT_RELA) 576 return (ENOEXEC); 577 break; 578 #ifdef GDB 579 case DT_DEBUG: 580 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 581 break; 582 #endif 583 } 584 } 585 586 if (plttype == DT_RELA) { 587 ef->pltrela = (const Elf_Rela *)ef->pltrel; 588 ef->pltrel = NULL; 589 ef->pltrelasize = ef->pltrelsize; 590 ef->pltrelsize = 0; 591 } 592 593 ef->ddbsymtab = ef->symtab; 594 ef->ddbsymcnt = ef->nchains; 595 ef->ddbstrtab = ef->strtab; 596 ef->ddbstrcnt = ef->strsz; 597 598 return (0); 599 } 600 601 static int 602 parse_dpcpu(elf_file_t ef) 603 { 604 int count; 605 int error; 606 607 ef->pcpu_start = 0; 608 ef->pcpu_stop = 0; 609 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 610 (void ***)&ef->pcpu_stop, &count); 611 /* Error just means there is no pcpu set to relocate. */ 612 if (error != 0) 613 return (0); 614 count *= sizeof(void *); 615 /* 616 * Allocate space in the primary pcpu area. Copy in our 617 * initialization from the data section and then initialize 618 * all per-cpu storage from that. 619 */ 620 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count); 621 if (ef->pcpu_base == 0) 622 return (ENOSPC); 623 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count); 624 dpcpu_copy((void *)ef->pcpu_base, count); 625 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 626 ef->pcpu_base); 627 628 return (0); 629 } 630 631 #ifdef VIMAGE 632 static int 633 parse_vnet(elf_file_t ef) 634 { 635 int count; 636 int error; 637 638 ef->vnet_start = 0; 639 ef->vnet_stop = 0; 640 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 641 (void ***)&ef->vnet_stop, &count); 642 /* Error just means there is no vnet data set to relocate. */ 643 if (error != 0) 644 return (0); 645 count *= sizeof(void *); 646 /* 647 * Allocate space in the primary vnet area. Copy in our 648 * initialization from the data section and then initialize 649 * all per-vnet storage from that. 650 */ 651 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count); 652 if (ef->vnet_base == 0) 653 return (ENOSPC); 654 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count); 655 vnet_data_copy((void *)ef->vnet_base, count); 656 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 657 ef->vnet_base); 658 659 return (0); 660 } 661 #endif 662 663 static int 664 link_elf_link_preload(linker_class_t cls, 665 const char* filename, linker_file_t *result) 666 { 667 Elf_Addr *ctors_addrp; 668 Elf_Size *ctors_sizep; 669 caddr_t modptr, baseptr, sizeptr, dynptr; 670 char *type; 671 elf_file_t ef; 672 linker_file_t lf; 673 int error; 674 vm_offset_t dp; 675 676 /* Look to see if we have the file preloaded */ 677 modptr = preload_search_by_name(filename); 678 if (modptr == NULL) 679 return (ENOENT); 680 681 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 682 baseptr = preload_search_info(modptr, MODINFO_ADDR); 683 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 684 dynptr = preload_search_info(modptr, 685 MODINFO_METADATA | MODINFOMD_DYNAMIC); 686 if (type == NULL || 687 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 688 strcmp(type, "elf module") != 0)) 689 return (EFTYPE); 690 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 691 return (EINVAL); 692 693 lf = linker_make_file(filename, &link_elf_class); 694 if (lf == NULL) 695 return (ENOMEM); 696 697 ef = (elf_file_t) lf; 698 ef->preloaded = 1; 699 ef->modptr = modptr; 700 ef->address = *(caddr_t *)baseptr; 701 #ifdef SPARSE_MAPPING 702 ef->object = 0; 703 #endif 704 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 705 ef->dynamic = (Elf_Dyn *)dp; 706 lf->address = ef->address; 707 lf->size = *(size_t *)sizeptr; 708 709 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 710 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 711 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 712 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 713 if (ctors_addrp != NULL && ctors_sizep != NULL) { 714 lf->ctors_addr = ef->address + *ctors_addrp; 715 lf->ctors_size = *ctors_sizep; 716 } 717 718 error = parse_dynamic(ef); 719 if (error == 0) 720 error = parse_dpcpu(ef); 721 #ifdef VIMAGE 722 if (error == 0) 723 error = parse_vnet(ef); 724 #endif 725 if (error != 0) { 726 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 727 return (error); 728 } 729 link_elf_reloc_local(lf); 730 *result = lf; 731 return (0); 732 } 733 734 static int 735 link_elf_link_preload_finish(linker_file_t lf) 736 { 737 elf_file_t ef; 738 int error; 739 740 ef = (elf_file_t) lf; 741 error = relocate_file(ef); 742 if (error != 0) 743 return (error); 744 (void)link_elf_preload_parse_symbols(ef); 745 746 return (link_elf_link_common_finish(lf)); 747 } 748 749 static int 750 link_elf_load_file(linker_class_t cls, const char* filename, 751 linker_file_t* result) 752 { 753 struct nameidata nd; 754 struct thread* td = curthread; /* XXX */ 755 Elf_Ehdr *hdr; 756 caddr_t firstpage; 757 int nbytes, i; 758 Elf_Phdr *phdr; 759 Elf_Phdr *phlimit; 760 Elf_Phdr *segs[MAXSEGS]; 761 int nsegs; 762 Elf_Phdr *phdyn; 763 Elf_Phdr *phphdr; 764 caddr_t mapbase; 765 size_t mapsize; 766 Elf_Off base_offset; 767 Elf_Addr base_vaddr; 768 Elf_Addr base_vlimit; 769 int error = 0; 770 ssize_t resid; 771 int flags; 772 elf_file_t ef; 773 linker_file_t lf; 774 Elf_Shdr *shdr; 775 int symtabindex; 776 int symstrindex; 777 int shstrindex; 778 int symcnt; 779 int strcnt; 780 char *shstrs; 781 782 shdr = NULL; 783 lf = NULL; 784 shstrs = NULL; 785 786 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 787 flags = FREAD; 788 error = vn_open(&nd, &flags, 0, NULL); 789 if (error != 0) 790 return (error); 791 NDFREE(&nd, NDF_ONLY_PNBUF); 792 if (nd.ni_vp->v_type != VREG) { 793 error = ENOEXEC; 794 firstpage = NULL; 795 goto out; 796 } 797 #ifdef MAC 798 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 799 if (error != 0) { 800 firstpage = NULL; 801 goto out; 802 } 803 #endif 804 805 /* 806 * Read the elf header from the file. 807 */ 808 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 809 hdr = (Elf_Ehdr *)firstpage; 810 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 811 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 812 &resid, td); 813 nbytes = PAGE_SIZE - resid; 814 if (error != 0) 815 goto out; 816 817 if (!IS_ELF(*hdr)) { 818 error = ENOEXEC; 819 goto out; 820 } 821 822 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 823 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 824 link_elf_error(filename, "Unsupported file layout"); 825 error = ENOEXEC; 826 goto out; 827 } 828 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 829 hdr->e_version != EV_CURRENT) { 830 link_elf_error(filename, "Unsupported file version"); 831 error = ENOEXEC; 832 goto out; 833 } 834 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 835 error = ENOSYS; 836 goto out; 837 } 838 if (hdr->e_machine != ELF_TARG_MACH) { 839 link_elf_error(filename, "Unsupported machine"); 840 error = ENOEXEC; 841 goto out; 842 } 843 844 /* 845 * We rely on the program header being in the first page. 846 * This is not strictly required by the ABI specification, but 847 * it seems to always true in practice. And, it simplifies 848 * things considerably. 849 */ 850 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 851 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 852 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 853 link_elf_error(filename, "Unreadable program headers"); 854 855 /* 856 * Scan the program header entries, and save key information. 857 * 858 * We rely on there being exactly two load segments, text and data, 859 * in that order. 860 */ 861 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 862 phlimit = phdr + hdr->e_phnum; 863 nsegs = 0; 864 phdyn = NULL; 865 phphdr = NULL; 866 while (phdr < phlimit) { 867 switch (phdr->p_type) { 868 case PT_LOAD: 869 if (nsegs == MAXSEGS) { 870 link_elf_error(filename, "Too many sections"); 871 error = ENOEXEC; 872 goto out; 873 } 874 /* 875 * XXX: We just trust they come in right order ?? 876 */ 877 segs[nsegs] = phdr; 878 ++nsegs; 879 break; 880 881 case PT_PHDR: 882 phphdr = phdr; 883 break; 884 885 case PT_DYNAMIC: 886 phdyn = phdr; 887 break; 888 889 case PT_INTERP: 890 error = ENOSYS; 891 goto out; 892 } 893 894 ++phdr; 895 } 896 if (phdyn == NULL) { 897 link_elf_error(filename, "Object is not dynamically-linked"); 898 error = ENOEXEC; 899 goto out; 900 } 901 if (nsegs == 0) { 902 link_elf_error(filename, "No sections"); 903 error = ENOEXEC; 904 goto out; 905 } 906 907 /* 908 * Allocate the entire address space of the object, to stake 909 * out our contiguous region, and to establish the base 910 * address for relocation. 911 */ 912 base_offset = trunc_page(segs[0]->p_offset); 913 base_vaddr = trunc_page(segs[0]->p_vaddr); 914 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 915 segs[nsegs - 1]->p_memsz); 916 mapsize = base_vlimit - base_vaddr; 917 918 lf = linker_make_file(filename, &link_elf_class); 919 if (lf == NULL) { 920 error = ENOMEM; 921 goto out; 922 } 923 924 ef = (elf_file_t) lf; 925 #ifdef SPARSE_MAPPING 926 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 927 if (ef->object == NULL) { 928 error = ENOMEM; 929 goto out; 930 } 931 ef->address = (caddr_t) vm_map_min(kernel_map); 932 error = vm_map_find(kernel_map, ef->object, 0, 933 (vm_offset_t *) &ef->address, mapsize, 0, VMFS_OPTIMAL_SPACE, 934 VM_PROT_ALL, VM_PROT_ALL, 0); 935 if (error != 0) { 936 vm_object_deallocate(ef->object); 937 ef->object = 0; 938 goto out; 939 } 940 #else 941 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 942 #endif 943 mapbase = ef->address; 944 945 /* 946 * Read the text and data sections and zero the bss. 947 */ 948 for (i = 0; i < nsegs; i++) { 949 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 950 error = vn_rdwr(UIO_READ, nd.ni_vp, 951 segbase, segs[i]->p_filesz, segs[i]->p_offset, 952 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 953 &resid, td); 954 if (error != 0) 955 goto out; 956 bzero(segbase + segs[i]->p_filesz, 957 segs[i]->p_memsz - segs[i]->p_filesz); 958 959 #ifdef SPARSE_MAPPING 960 /* 961 * Wire down the pages 962 */ 963 error = vm_map_wire(kernel_map, 964 (vm_offset_t) segbase, 965 (vm_offset_t) segbase + segs[i]->p_memsz, 966 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 967 if (error != KERN_SUCCESS) { 968 error = ENOMEM; 969 goto out; 970 } 971 #endif 972 } 973 974 #ifdef GPROF 975 /* Update profiling information with the new text segment. */ 976 mtx_lock(&Giant); 977 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 978 segs[0]->p_memsz)); 979 mtx_unlock(&Giant); 980 #endif 981 982 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 983 984 lf->address = ef->address; 985 lf->size = mapsize; 986 987 error = parse_dynamic(ef); 988 if (error != 0) 989 goto out; 990 error = parse_dpcpu(ef); 991 if (error != 0) 992 goto out; 993 #ifdef VIMAGE 994 error = parse_vnet(ef); 995 if (error != 0) 996 goto out; 997 #endif 998 link_elf_reloc_local(lf); 999 1000 VOP_UNLOCK(nd.ni_vp, 0); 1001 error = linker_load_dependencies(lf); 1002 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 1003 if (error != 0) 1004 goto out; 1005 error = relocate_file(ef); 1006 if (error != 0) 1007 goto out; 1008 1009 /* 1010 * Try and load the symbol table if it's present. (you can 1011 * strip it!) 1012 */ 1013 nbytes = hdr->e_shnum * hdr->e_shentsize; 1014 if (nbytes == 0 || hdr->e_shoff == 0) 1015 goto nosyms; 1016 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1017 error = vn_rdwr(UIO_READ, nd.ni_vp, 1018 (caddr_t)shdr, nbytes, hdr->e_shoff, 1019 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1020 &resid, td); 1021 if (error != 0) 1022 goto out; 1023 1024 /* Read section string table */ 1025 shstrindex = hdr->e_shstrndx; 1026 if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB && 1027 shdr[shstrindex].sh_size != 0) { 1028 nbytes = shdr[shstrindex].sh_size; 1029 shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1030 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes, 1031 shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 1032 td->td_ucred, NOCRED, &resid, td); 1033 if (error) 1034 goto out; 1035 } 1036 1037 symtabindex = -1; 1038 symstrindex = -1; 1039 for (i = 0; i < hdr->e_shnum; i++) { 1040 if (shdr[i].sh_type == SHT_SYMTAB) { 1041 symtabindex = i; 1042 symstrindex = shdr[i].sh_link; 1043 } else if (shstrs != NULL && shdr[i].sh_name != 0 && 1044 strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) { 1045 /* Record relocated address and size of .ctors. */ 1046 lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr; 1047 lf->ctors_size = shdr[i].sh_size; 1048 } 1049 } 1050 if (symtabindex < 0 || symstrindex < 0) 1051 goto nosyms; 1052 1053 symcnt = shdr[symtabindex].sh_size; 1054 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1055 strcnt = shdr[symstrindex].sh_size; 1056 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1057 1058 error = vn_rdwr(UIO_READ, nd.ni_vp, 1059 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1060 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1061 &resid, td); 1062 if (error != 0) 1063 goto out; 1064 error = vn_rdwr(UIO_READ, nd.ni_vp, 1065 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1066 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1067 &resid, td); 1068 if (error != 0) 1069 goto out; 1070 1071 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1072 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1073 ef->ddbstrcnt = strcnt; 1074 ef->ddbstrtab = ef->strbase; 1075 1076 nosyms: 1077 error = link_elf_link_common_finish(lf); 1078 if (error != 0) 1079 goto out; 1080 1081 *result = lf; 1082 1083 out: 1084 VOP_UNLOCK(nd.ni_vp, 0); 1085 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1086 if (error != 0 && lf != NULL) 1087 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1088 if (shdr != NULL) 1089 free(shdr, M_LINKER); 1090 if (firstpage != NULL) 1091 free(firstpage, M_LINKER); 1092 if (shstrs != NULL) 1093 free(shstrs, M_LINKER); 1094 1095 return (error); 1096 } 1097 1098 Elf_Addr 1099 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1100 { 1101 elf_file_t ef; 1102 1103 ef = (elf_file_t)lf; 1104 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1105 return ((x - ef->pcpu_start) + ef->pcpu_base); 1106 #ifdef VIMAGE 1107 if (x >= ef->vnet_start && x < ef->vnet_stop) 1108 return ((x - ef->vnet_start) + ef->vnet_base); 1109 #endif 1110 return (x); 1111 } 1112 1113 1114 static void 1115 link_elf_unload_file(linker_file_t file) 1116 { 1117 elf_file_t ef = (elf_file_t) file; 1118 1119 if (ef->pcpu_base != 0) { 1120 dpcpu_free((void *)ef->pcpu_base, 1121 ef->pcpu_stop - ef->pcpu_start); 1122 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1123 } 1124 #ifdef VIMAGE 1125 if (ef->vnet_base != 0) { 1126 vnet_data_free((void *)ef->vnet_base, 1127 ef->vnet_stop - ef->vnet_start); 1128 elf_set_delete(&set_vnet_list, ef->vnet_start); 1129 } 1130 #endif 1131 #ifdef GDB 1132 if (ef->gdb.l_ld != NULL) { 1133 GDB_STATE(RT_DELETE); 1134 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1135 link_elf_delete_gdb(&ef->gdb); 1136 GDB_STATE(RT_CONSISTENT); 1137 } 1138 #endif 1139 1140 /* Notify MD code that a module is being unloaded. */ 1141 elf_cpu_unload_file(file); 1142 1143 if (ef->preloaded) { 1144 link_elf_unload_preload(file); 1145 return; 1146 } 1147 1148 #ifdef SPARSE_MAPPING 1149 if (ef->object != NULL) { 1150 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1151 (vm_offset_t) ef->address 1152 + (ef->object->size << PAGE_SHIFT)); 1153 } 1154 #else 1155 if (ef->address != NULL) 1156 free(ef->address, M_LINKER); 1157 #endif 1158 if (ef->symbase != NULL) 1159 free(ef->symbase, M_LINKER); 1160 if (ef->strbase != NULL) 1161 free(ef->strbase, M_LINKER); 1162 if (ef->ctftab != NULL) 1163 free(ef->ctftab, M_LINKER); 1164 if (ef->ctfoff != NULL) 1165 free(ef->ctfoff, M_LINKER); 1166 if (ef->typoff != NULL) 1167 free(ef->typoff, M_LINKER); 1168 } 1169 1170 static void 1171 link_elf_unload_preload(linker_file_t file) 1172 { 1173 if (file->filename != NULL) 1174 preload_delete_name(file->filename); 1175 } 1176 1177 static const char * 1178 symbol_name(elf_file_t ef, Elf_Size r_info) 1179 { 1180 const Elf_Sym *ref; 1181 1182 if (ELF_R_SYM(r_info)) { 1183 ref = ef->symtab + ELF_R_SYM(r_info); 1184 return (ef->strtab + ref->st_name); 1185 } 1186 return (NULL); 1187 } 1188 1189 static int 1190 relocate_file(elf_file_t ef) 1191 { 1192 const Elf_Rel *rellim; 1193 const Elf_Rel *rel; 1194 const Elf_Rela *relalim; 1195 const Elf_Rela *rela; 1196 const char *symname; 1197 1198 /* Perform relocations without addend if there are any: */ 1199 rel = ef->rel; 1200 if (rel != NULL) { 1201 rellim = (const Elf_Rel *) 1202 ((const char *)ef->rel + ef->relsize); 1203 while (rel < rellim) { 1204 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1205 ELF_RELOC_REL, elf_lookup)) { 1206 symname = symbol_name(ef, rel->r_info); 1207 printf("link_elf: symbol %s undefined\n", symname); 1208 return (ENOENT); 1209 } 1210 rel++; 1211 } 1212 } 1213 1214 /* Perform relocations with addend if there are any: */ 1215 rela = ef->rela; 1216 if (rela != NULL) { 1217 relalim = (const Elf_Rela *) 1218 ((const char *)ef->rela + ef->relasize); 1219 while (rela < relalim) { 1220 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1221 ELF_RELOC_RELA, elf_lookup)) { 1222 symname = symbol_name(ef, rela->r_info); 1223 printf("link_elf: symbol %s undefined\n", 1224 symname); 1225 return (ENOENT); 1226 } 1227 rela++; 1228 } 1229 } 1230 1231 /* Perform PLT relocations without addend if there are any: */ 1232 rel = ef->pltrel; 1233 if (rel != NULL) { 1234 rellim = (const Elf_Rel *) 1235 ((const char *)ef->pltrel + ef->pltrelsize); 1236 while (rel < rellim) { 1237 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1238 ELF_RELOC_REL, elf_lookup)) { 1239 symname = symbol_name(ef, rel->r_info); 1240 printf("link_elf: symbol %s undefined\n", 1241 symname); 1242 return (ENOENT); 1243 } 1244 rel++; 1245 } 1246 } 1247 1248 /* Perform relocations with addend if there are any: */ 1249 rela = ef->pltrela; 1250 if (rela != NULL) { 1251 relalim = (const Elf_Rela *) 1252 ((const char *)ef->pltrela + ef->pltrelasize); 1253 while (rela < relalim) { 1254 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1255 ELF_RELOC_RELA, elf_lookup)) { 1256 symname = symbol_name(ef, rela->r_info); 1257 printf("link_elf: symbol %s undefined\n", 1258 symname); 1259 return (ENOENT); 1260 } 1261 rela++; 1262 } 1263 } 1264 1265 return (0); 1266 } 1267 1268 /* 1269 * Hash function for symbol table lookup. Don't even think about changing 1270 * this. It is specified by the System V ABI. 1271 */ 1272 static unsigned long 1273 elf_hash(const char *name) 1274 { 1275 const unsigned char *p = (const unsigned char *) name; 1276 unsigned long h = 0; 1277 unsigned long g; 1278 1279 while (*p != '\0') { 1280 h = (h << 4) + *p++; 1281 if ((g = h & 0xf0000000) != 0) 1282 h ^= g >> 24; 1283 h &= ~g; 1284 } 1285 return (h); 1286 } 1287 1288 static int 1289 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1290 { 1291 elf_file_t ef = (elf_file_t) lf; 1292 unsigned long symnum; 1293 const Elf_Sym* symp; 1294 const char *strp; 1295 unsigned long hash; 1296 int i; 1297 1298 /* If we don't have a hash, bail. */ 1299 if (ef->buckets == NULL || ef->nbuckets == 0) { 1300 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1301 return (ENOENT); 1302 } 1303 1304 /* First, search hashed global symbols */ 1305 hash = elf_hash(name); 1306 symnum = ef->buckets[hash % ef->nbuckets]; 1307 1308 while (symnum != STN_UNDEF) { 1309 if (symnum >= ef->nchains) { 1310 printf("%s: corrupt symbol table\n", __func__); 1311 return (ENOENT); 1312 } 1313 1314 symp = ef->symtab + symnum; 1315 if (symp->st_name == 0) { 1316 printf("%s: corrupt symbol table\n", __func__); 1317 return (ENOENT); 1318 } 1319 1320 strp = ef->strtab + symp->st_name; 1321 1322 if (strcmp(name, strp) == 0) { 1323 if (symp->st_shndx != SHN_UNDEF || 1324 (symp->st_value != 0 && 1325 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1326 *sym = (c_linker_sym_t) symp; 1327 return (0); 1328 } 1329 return (ENOENT); 1330 } 1331 1332 symnum = ef->chains[symnum]; 1333 } 1334 1335 /* If we have not found it, look at the full table (if loaded) */ 1336 if (ef->symtab == ef->ddbsymtab) 1337 return (ENOENT); 1338 1339 /* Exhaustive search */ 1340 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1341 strp = ef->ddbstrtab + symp->st_name; 1342 if (strcmp(name, strp) == 0) { 1343 if (symp->st_shndx != SHN_UNDEF || 1344 (symp->st_value != 0 && 1345 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1346 *sym = (c_linker_sym_t) symp; 1347 return (0); 1348 } 1349 return (ENOENT); 1350 } 1351 } 1352 1353 return (ENOENT); 1354 } 1355 1356 static int 1357 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1358 linker_symval_t *symval) 1359 { 1360 elf_file_t ef = (elf_file_t) lf; 1361 const Elf_Sym* es = (const Elf_Sym*) sym; 1362 1363 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1364 symval->name = ef->strtab + es->st_name; 1365 symval->value = (caddr_t) ef->address + es->st_value; 1366 symval->size = es->st_size; 1367 return (0); 1368 } 1369 if (ef->symtab == ef->ddbsymtab) 1370 return (ENOENT); 1371 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1372 symval->name = ef->ddbstrtab + es->st_name; 1373 symval->value = (caddr_t) ef->address + es->st_value; 1374 symval->size = es->st_size; 1375 return (0); 1376 } 1377 return (ENOENT); 1378 } 1379 1380 static int 1381 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1382 c_linker_sym_t *sym, long *diffp) 1383 { 1384 elf_file_t ef = (elf_file_t) lf; 1385 u_long off = (uintptr_t) (void *) value; 1386 u_long diff = off; 1387 u_long st_value; 1388 const Elf_Sym* es; 1389 const Elf_Sym* best = 0; 1390 int i; 1391 1392 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1393 if (es->st_name == 0) 1394 continue; 1395 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1396 if (off >= st_value) { 1397 if (off - st_value < diff) { 1398 diff = off - st_value; 1399 best = es; 1400 if (diff == 0) 1401 break; 1402 } else if (off - st_value == diff) { 1403 best = es; 1404 } 1405 } 1406 } 1407 if (best == 0) 1408 *diffp = off; 1409 else 1410 *diffp = diff; 1411 *sym = (c_linker_sym_t) best; 1412 1413 return (0); 1414 } 1415 1416 /* 1417 * Look up a linker set on an ELF system. 1418 */ 1419 static int 1420 link_elf_lookup_set(linker_file_t lf, const char *name, 1421 void ***startp, void ***stopp, int *countp) 1422 { 1423 c_linker_sym_t sym; 1424 linker_symval_t symval; 1425 char *setsym; 1426 void **start, **stop; 1427 int len, error = 0, count; 1428 1429 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1430 setsym = malloc(len, M_LINKER, M_WAITOK); 1431 1432 /* get address of first entry */ 1433 snprintf(setsym, len, "%s%s", "__start_set_", name); 1434 error = link_elf_lookup_symbol(lf, setsym, &sym); 1435 if (error != 0) 1436 goto out; 1437 link_elf_symbol_values(lf, sym, &symval); 1438 if (symval.value == 0) { 1439 error = ESRCH; 1440 goto out; 1441 } 1442 start = (void **)symval.value; 1443 1444 /* get address of last entry */ 1445 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1446 error = link_elf_lookup_symbol(lf, setsym, &sym); 1447 if (error != 0) 1448 goto out; 1449 link_elf_symbol_values(lf, sym, &symval); 1450 if (symval.value == 0) { 1451 error = ESRCH; 1452 goto out; 1453 } 1454 stop = (void **)symval.value; 1455 1456 /* and the number of entries */ 1457 count = stop - start; 1458 1459 /* and copy out */ 1460 if (startp != NULL) 1461 *startp = start; 1462 if (stopp != NULL) 1463 *stopp = stop; 1464 if (countp != NULL) 1465 *countp = count; 1466 1467 out: 1468 free(setsym, M_LINKER); 1469 return (error); 1470 } 1471 1472 static int 1473 link_elf_each_function_name(linker_file_t file, 1474 int (*callback)(const char *, void *), void *opaque) 1475 { 1476 elf_file_t ef = (elf_file_t)file; 1477 const Elf_Sym *symp; 1478 int i, error; 1479 1480 /* Exhaustive search */ 1481 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1482 if (symp->st_value != 0 && 1483 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1484 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1485 if (error != 0) 1486 return (error); 1487 } 1488 } 1489 return (0); 1490 } 1491 1492 static int 1493 link_elf_each_function_nameval(linker_file_t file, 1494 linker_function_nameval_callback_t callback, void *opaque) 1495 { 1496 linker_symval_t symval; 1497 elf_file_t ef = (elf_file_t)file; 1498 const Elf_Sym* symp; 1499 int i, error; 1500 1501 /* Exhaustive search */ 1502 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1503 if (symp->st_value != 0 && 1504 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1505 error = link_elf_symbol_values(file, 1506 (c_linker_sym_t) symp, &symval); 1507 if (error != 0) 1508 return (error); 1509 error = callback(file, i, &symval, opaque); 1510 if (error != 0) 1511 return (error); 1512 } 1513 } 1514 return (0); 1515 } 1516 1517 const Elf_Sym * 1518 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1519 { 1520 elf_file_t ef = (elf_file_t)lf; 1521 1522 if (symidx >= ef->nchains) 1523 return (NULL); 1524 return (ef->symtab + symidx); 1525 } 1526 1527 const char * 1528 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1529 { 1530 elf_file_t ef = (elf_file_t)lf; 1531 const Elf_Sym *sym; 1532 1533 if (symidx >= ef->nchains) 1534 return (NULL); 1535 sym = ef->symtab + symidx; 1536 return (ef->strtab + sym->st_name); 1537 } 1538 1539 /* 1540 * Symbol lookup function that can be used when the symbol index is known (ie 1541 * in relocations). It uses the symbol index instead of doing a fully fledged 1542 * hash table based lookup when such is valid. For example for local symbols. 1543 * This is not only more efficient, it's also more correct. It's not always 1544 * the case that the symbol can be found through the hash table. 1545 */ 1546 static Elf_Addr 1547 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1548 { 1549 elf_file_t ef = (elf_file_t)lf; 1550 const Elf_Sym *sym; 1551 const char *symbol; 1552 Elf_Addr addr, start, base; 1553 1554 /* Don't even try to lookup the symbol if the index is bogus. */ 1555 if (symidx >= ef->nchains) 1556 return (0); 1557 1558 sym = ef->symtab + symidx; 1559 1560 /* 1561 * Don't do a full lookup when the symbol is local. It may even 1562 * fail because it may not be found through the hash table. 1563 */ 1564 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1565 /* Force lookup failure when we have an insanity. */ 1566 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) 1567 return (0); 1568 return ((Elf_Addr)ef->address + sym->st_value); 1569 } 1570 1571 /* 1572 * XXX we can avoid doing a hash table based lookup for global 1573 * symbols as well. This however is not always valid, so we'll 1574 * just do it the hard way for now. Performance tweaks can 1575 * always be added. 1576 */ 1577 1578 symbol = ef->strtab + sym->st_name; 1579 1580 /* Force a lookup failure if the symbol name is bogus. */ 1581 if (*symbol == 0) 1582 return (0); 1583 1584 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1585 1586 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1587 addr = addr - start + base; 1588 #ifdef VIMAGE 1589 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1590 addr = addr - start + base; 1591 #endif 1592 return addr; 1593 } 1594 1595 static void 1596 link_elf_reloc_local(linker_file_t lf) 1597 { 1598 const Elf_Rel *rellim; 1599 const Elf_Rel *rel; 1600 const Elf_Rela *relalim; 1601 const Elf_Rela *rela; 1602 elf_file_t ef = (elf_file_t)lf; 1603 1604 /* Perform relocations without addend if there are any: */ 1605 if ((rel = ef->rel) != NULL) { 1606 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1607 while (rel < rellim) { 1608 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1609 ELF_RELOC_REL, elf_lookup); 1610 rel++; 1611 } 1612 } 1613 1614 /* Perform relocations with addend if there are any: */ 1615 if ((rela = ef->rela) != NULL) { 1616 relalim = (const Elf_Rela *) 1617 ((const char *)ef->rela + ef->relasize); 1618 while (rela < relalim) { 1619 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1620 ELF_RELOC_RELA, elf_lookup); 1621 rela++; 1622 } 1623 } 1624 } 1625 1626 static long 1627 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1628 { 1629 elf_file_t ef = (elf_file_t)lf; 1630 1631 *symtab = ef->ddbsymtab; 1632 1633 if (*symtab == NULL) 1634 return (0); 1635 1636 return (ef->ddbsymcnt); 1637 } 1638 1639 static long 1640 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1641 { 1642 elf_file_t ef = (elf_file_t)lf; 1643 1644 *strtab = ef->ddbstrtab; 1645 1646 if (*strtab == NULL) 1647 return (0); 1648 1649 return (ef->ddbstrcnt); 1650 } 1651