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 <sys/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 extern vm_offset_t __startkernel; 385 386 static void 387 link_elf_init(void* arg) 388 { 389 Elf_Dyn *dp; 390 Elf_Addr *ctors_addrp; 391 Elf_Size *ctors_sizep; 392 caddr_t modptr, baseptr, sizeptr; 393 elf_file_t ef; 394 char *modname; 395 396 linker_add_class(&link_elf_class); 397 398 dp = (Elf_Dyn *)&_DYNAMIC; 399 modname = NULL; 400 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 401 if (modptr == NULL) 402 modptr = preload_search_by_type("elf kernel"); 403 if (modptr != NULL) 404 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 405 if (modname == NULL) 406 modname = "kernel"; 407 linker_kernel_file = linker_make_file(modname, &link_elf_class); 408 if (linker_kernel_file == NULL) 409 panic("%s: Can't create linker structures for kernel", 410 __func__); 411 412 ef = (elf_file_t) linker_kernel_file; 413 ef->preloaded = 1; 414 #ifdef __powerpc__ 415 ef->address = (caddr_t) (__startkernel - KERNBASE); 416 #else 417 ef->address = 0; 418 #endif 419 #ifdef SPARSE_MAPPING 420 ef->object = 0; 421 #endif 422 ef->dynamic = dp; 423 424 if (dp != NULL) 425 parse_dynamic(ef); 426 linker_kernel_file->address += KERNBASE; 427 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 428 429 if (modptr != NULL) { 430 ef->modptr = modptr; 431 baseptr = preload_search_info(modptr, MODINFO_ADDR); 432 if (baseptr != NULL) 433 linker_kernel_file->address = *(caddr_t *)baseptr; 434 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 435 if (sizeptr != NULL) 436 linker_kernel_file->size = *(size_t *)sizeptr; 437 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 438 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 439 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 440 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 441 if (ctors_addrp != NULL && ctors_sizep != NULL) { 442 linker_kernel_file->ctors_addr = ef->address + 443 *ctors_addrp; 444 linker_kernel_file->ctors_size = *ctors_sizep; 445 } 446 } 447 (void)link_elf_preload_parse_symbols(ef); 448 449 #ifdef GDB 450 r_debug.r_map = NULL; 451 r_debug.r_brk = r_debug_state; 452 r_debug.r_state = RT_CONSISTENT; 453 #endif 454 455 (void)link_elf_link_common_finish(linker_kernel_file); 456 linker_kernel_file->flags |= LINKER_FILE_LINKED; 457 TAILQ_INIT(&set_pcpu_list); 458 #ifdef VIMAGE 459 TAILQ_INIT(&set_vnet_list); 460 #endif 461 } 462 463 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0); 464 465 static int 466 link_elf_preload_parse_symbols(elf_file_t ef) 467 { 468 caddr_t pointer; 469 caddr_t ssym, esym, base; 470 caddr_t strtab; 471 int strcnt; 472 Elf_Sym *symtab; 473 int symcnt; 474 475 if (ef->modptr == NULL) 476 return (0); 477 pointer = preload_search_info(ef->modptr, 478 MODINFO_METADATA | MODINFOMD_SSYM); 479 if (pointer == NULL) 480 return (0); 481 ssym = *(caddr_t *)pointer; 482 pointer = preload_search_info(ef->modptr, 483 MODINFO_METADATA | MODINFOMD_ESYM); 484 if (pointer == NULL) 485 return (0); 486 esym = *(caddr_t *)pointer; 487 488 base = ssym; 489 490 symcnt = *(long *)base; 491 base += sizeof(long); 492 symtab = (Elf_Sym *)base; 493 base += roundup(symcnt, sizeof(long)); 494 495 if (base > esym || base < ssym) { 496 printf("Symbols are corrupt!\n"); 497 return (EINVAL); 498 } 499 500 strcnt = *(long *)base; 501 base += sizeof(long); 502 strtab = base; 503 base += roundup(strcnt, sizeof(long)); 504 505 if (base > esym || base < ssym) { 506 printf("Symbols are corrupt!\n"); 507 return (EINVAL); 508 } 509 510 ef->ddbsymtab = symtab; 511 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 512 ef->ddbstrtab = strtab; 513 ef->ddbstrcnt = strcnt; 514 515 return (0); 516 } 517 518 static int 519 parse_dynamic(elf_file_t ef) 520 { 521 Elf_Dyn *dp; 522 int plttype = DT_REL; 523 524 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 525 switch (dp->d_tag) { 526 case DT_HASH: 527 { 528 /* From src/libexec/rtld-elf/rtld.c */ 529 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 530 (ef->address + dp->d_un.d_ptr); 531 ef->nbuckets = hashtab[0]; 532 ef->nchains = hashtab[1]; 533 ef->buckets = hashtab + 2; 534 ef->chains = ef->buckets + ef->nbuckets; 535 break; 536 } 537 case DT_STRTAB: 538 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 539 break; 540 case DT_STRSZ: 541 ef->strsz = dp->d_un.d_val; 542 break; 543 case DT_SYMTAB: 544 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 545 break; 546 case DT_SYMENT: 547 if (dp->d_un.d_val != sizeof(Elf_Sym)) 548 return (ENOEXEC); 549 break; 550 case DT_PLTGOT: 551 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 552 break; 553 case DT_REL: 554 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 555 break; 556 case DT_RELSZ: 557 ef->relsize = dp->d_un.d_val; 558 break; 559 case DT_RELENT: 560 if (dp->d_un.d_val != sizeof(Elf_Rel)) 561 return (ENOEXEC); 562 break; 563 case DT_JMPREL: 564 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 565 break; 566 case DT_PLTRELSZ: 567 ef->pltrelsize = dp->d_un.d_val; 568 break; 569 case DT_RELA: 570 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 571 break; 572 case DT_RELASZ: 573 ef->relasize = dp->d_un.d_val; 574 break; 575 case DT_RELAENT: 576 if (dp->d_un.d_val != sizeof(Elf_Rela)) 577 return (ENOEXEC); 578 break; 579 case DT_PLTREL: 580 plttype = dp->d_un.d_val; 581 if (plttype != DT_REL && plttype != DT_RELA) 582 return (ENOEXEC); 583 break; 584 #ifdef GDB 585 case DT_DEBUG: 586 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 587 break; 588 #endif 589 } 590 } 591 592 if (plttype == DT_RELA) { 593 ef->pltrela = (const Elf_Rela *)ef->pltrel; 594 ef->pltrel = NULL; 595 ef->pltrelasize = ef->pltrelsize; 596 ef->pltrelsize = 0; 597 } 598 599 ef->ddbsymtab = ef->symtab; 600 ef->ddbsymcnt = ef->nchains; 601 ef->ddbstrtab = ef->strtab; 602 ef->ddbstrcnt = ef->strsz; 603 604 return (0); 605 } 606 607 static int 608 parse_dpcpu(elf_file_t ef) 609 { 610 int count; 611 int error; 612 613 ef->pcpu_start = 0; 614 ef->pcpu_stop = 0; 615 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 616 (void ***)&ef->pcpu_stop, &count); 617 /* Error just means there is no pcpu set to relocate. */ 618 if (error != 0) 619 return (0); 620 count *= sizeof(void *); 621 /* 622 * Allocate space in the primary pcpu area. Copy in our 623 * initialization from the data section and then initialize 624 * all per-cpu storage from that. 625 */ 626 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count); 627 if (ef->pcpu_base == 0) 628 return (ENOSPC); 629 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count); 630 dpcpu_copy((void *)ef->pcpu_base, count); 631 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 632 ef->pcpu_base); 633 634 return (0); 635 } 636 637 #ifdef VIMAGE 638 static int 639 parse_vnet(elf_file_t ef) 640 { 641 int count; 642 int error; 643 644 ef->vnet_start = 0; 645 ef->vnet_stop = 0; 646 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 647 (void ***)&ef->vnet_stop, &count); 648 /* Error just means there is no vnet data set to relocate. */ 649 if (error != 0) 650 return (0); 651 count *= sizeof(void *); 652 /* 653 * Allocate space in the primary vnet area. Copy in our 654 * initialization from the data section and then initialize 655 * all per-vnet storage from that. 656 */ 657 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count); 658 if (ef->vnet_base == 0) 659 return (ENOSPC); 660 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count); 661 vnet_data_copy((void *)ef->vnet_base, count); 662 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 663 ef->vnet_base); 664 665 return (0); 666 } 667 #endif 668 669 static int 670 link_elf_link_preload(linker_class_t cls, 671 const char* filename, linker_file_t *result) 672 { 673 Elf_Addr *ctors_addrp; 674 Elf_Size *ctors_sizep; 675 caddr_t modptr, baseptr, sizeptr, dynptr; 676 char *type; 677 elf_file_t ef; 678 linker_file_t lf; 679 int error; 680 vm_offset_t dp; 681 682 /* Look to see if we have the file preloaded */ 683 modptr = preload_search_by_name(filename); 684 if (modptr == NULL) 685 return (ENOENT); 686 687 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 688 baseptr = preload_search_info(modptr, MODINFO_ADDR); 689 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 690 dynptr = preload_search_info(modptr, 691 MODINFO_METADATA | MODINFOMD_DYNAMIC); 692 if (type == NULL || 693 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 694 strcmp(type, "elf module") != 0)) 695 return (EFTYPE); 696 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 697 return (EINVAL); 698 699 lf = linker_make_file(filename, &link_elf_class); 700 if (lf == NULL) 701 return (ENOMEM); 702 703 ef = (elf_file_t) lf; 704 ef->preloaded = 1; 705 ef->modptr = modptr; 706 ef->address = *(caddr_t *)baseptr; 707 #ifdef SPARSE_MAPPING 708 ef->object = 0; 709 #endif 710 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 711 ef->dynamic = (Elf_Dyn *)dp; 712 lf->address = ef->address; 713 lf->size = *(size_t *)sizeptr; 714 715 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 716 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 717 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 718 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 719 if (ctors_addrp != NULL && ctors_sizep != NULL) { 720 lf->ctors_addr = ef->address + *ctors_addrp; 721 lf->ctors_size = *ctors_sizep; 722 } 723 724 error = parse_dynamic(ef); 725 if (error == 0) 726 error = parse_dpcpu(ef); 727 #ifdef VIMAGE 728 if (error == 0) 729 error = parse_vnet(ef); 730 #endif 731 if (error != 0) { 732 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 733 return (error); 734 } 735 link_elf_reloc_local(lf); 736 *result = lf; 737 return (0); 738 } 739 740 static int 741 link_elf_link_preload_finish(linker_file_t lf) 742 { 743 elf_file_t ef; 744 int error; 745 746 ef = (elf_file_t) lf; 747 error = relocate_file(ef); 748 if (error != 0) 749 return (error); 750 (void)link_elf_preload_parse_symbols(ef); 751 752 return (link_elf_link_common_finish(lf)); 753 } 754 755 static int 756 link_elf_load_file(linker_class_t cls, const char* filename, 757 linker_file_t* result) 758 { 759 struct nameidata nd; 760 struct thread* td = curthread; /* XXX */ 761 Elf_Ehdr *hdr; 762 caddr_t firstpage; 763 int nbytes, i; 764 Elf_Phdr *phdr; 765 Elf_Phdr *phlimit; 766 Elf_Phdr *segs[MAXSEGS]; 767 int nsegs; 768 Elf_Phdr *phdyn; 769 Elf_Phdr *phphdr; 770 caddr_t mapbase; 771 size_t mapsize; 772 Elf_Off base_offset; 773 Elf_Addr base_vaddr; 774 Elf_Addr base_vlimit; 775 int error = 0; 776 ssize_t resid; 777 int flags; 778 elf_file_t ef; 779 linker_file_t lf; 780 Elf_Shdr *shdr; 781 int symtabindex; 782 int symstrindex; 783 int shstrindex; 784 int symcnt; 785 int strcnt; 786 char *shstrs; 787 788 shdr = NULL; 789 lf = NULL; 790 shstrs = NULL; 791 792 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 793 flags = FREAD; 794 error = vn_open(&nd, &flags, 0, NULL); 795 if (error != 0) 796 return (error); 797 NDFREE(&nd, NDF_ONLY_PNBUF); 798 if (nd.ni_vp->v_type != VREG) { 799 error = ENOEXEC; 800 firstpage = NULL; 801 goto out; 802 } 803 #ifdef MAC 804 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 805 if (error != 0) { 806 firstpage = NULL; 807 goto out; 808 } 809 #endif 810 811 /* 812 * Read the elf header from the file. 813 */ 814 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 815 hdr = (Elf_Ehdr *)firstpage; 816 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 817 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 818 &resid, td); 819 nbytes = PAGE_SIZE - resid; 820 if (error != 0) 821 goto out; 822 823 if (!IS_ELF(*hdr)) { 824 error = ENOEXEC; 825 goto out; 826 } 827 828 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 829 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 830 link_elf_error(filename, "Unsupported file layout"); 831 error = ENOEXEC; 832 goto out; 833 } 834 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 835 hdr->e_version != EV_CURRENT) { 836 link_elf_error(filename, "Unsupported file version"); 837 error = ENOEXEC; 838 goto out; 839 } 840 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 841 error = ENOSYS; 842 goto out; 843 } 844 if (hdr->e_machine != ELF_TARG_MACH) { 845 link_elf_error(filename, "Unsupported machine"); 846 error = ENOEXEC; 847 goto out; 848 } 849 850 /* 851 * We rely on the program header being in the first page. 852 * This is not strictly required by the ABI specification, but 853 * it seems to always true in practice. And, it simplifies 854 * things considerably. 855 */ 856 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 857 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 858 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 859 link_elf_error(filename, "Unreadable program headers"); 860 861 /* 862 * Scan the program header entries, and save key information. 863 * 864 * We rely on there being exactly two load segments, text and data, 865 * in that order. 866 */ 867 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 868 phlimit = phdr + hdr->e_phnum; 869 nsegs = 0; 870 phdyn = NULL; 871 phphdr = NULL; 872 while (phdr < phlimit) { 873 switch (phdr->p_type) { 874 case PT_LOAD: 875 if (nsegs == MAXSEGS) { 876 link_elf_error(filename, "Too many sections"); 877 error = ENOEXEC; 878 goto out; 879 } 880 /* 881 * XXX: We just trust they come in right order ?? 882 */ 883 segs[nsegs] = phdr; 884 ++nsegs; 885 break; 886 887 case PT_PHDR: 888 phphdr = phdr; 889 break; 890 891 case PT_DYNAMIC: 892 phdyn = phdr; 893 break; 894 895 case PT_INTERP: 896 error = ENOSYS; 897 goto out; 898 } 899 900 ++phdr; 901 } 902 if (phdyn == NULL) { 903 link_elf_error(filename, "Object is not dynamically-linked"); 904 error = ENOEXEC; 905 goto out; 906 } 907 if (nsegs == 0) { 908 link_elf_error(filename, "No sections"); 909 error = ENOEXEC; 910 goto out; 911 } 912 913 /* 914 * Allocate the entire address space of the object, to stake 915 * out our contiguous region, and to establish the base 916 * address for relocation. 917 */ 918 base_offset = trunc_page(segs[0]->p_offset); 919 base_vaddr = trunc_page(segs[0]->p_vaddr); 920 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 921 segs[nsegs - 1]->p_memsz); 922 mapsize = base_vlimit - base_vaddr; 923 924 lf = linker_make_file(filename, &link_elf_class); 925 if (lf == NULL) { 926 error = ENOMEM; 927 goto out; 928 } 929 930 ef = (elf_file_t) lf; 931 #ifdef SPARSE_MAPPING 932 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 933 if (ef->object == NULL) { 934 error = ENOMEM; 935 goto out; 936 } 937 ef->address = (caddr_t) vm_map_min(kernel_map); 938 error = vm_map_find(kernel_map, ef->object, 0, 939 (vm_offset_t *) &ef->address, mapsize, 0, VMFS_OPTIMAL_SPACE, 940 VM_PROT_ALL, VM_PROT_ALL, 0); 941 if (error != 0) { 942 vm_object_deallocate(ef->object); 943 ef->object = 0; 944 goto out; 945 } 946 #else 947 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 948 #endif 949 mapbase = ef->address; 950 951 /* 952 * Read the text and data sections and zero the bss. 953 */ 954 for (i = 0; i < nsegs; i++) { 955 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 956 error = vn_rdwr(UIO_READ, nd.ni_vp, 957 segbase, segs[i]->p_filesz, segs[i]->p_offset, 958 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 959 &resid, td); 960 if (error != 0) 961 goto out; 962 bzero(segbase + segs[i]->p_filesz, 963 segs[i]->p_memsz - segs[i]->p_filesz); 964 965 #ifdef SPARSE_MAPPING 966 /* 967 * Wire down the pages 968 */ 969 error = vm_map_wire(kernel_map, 970 (vm_offset_t) segbase, 971 (vm_offset_t) segbase + segs[i]->p_memsz, 972 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 973 if (error != KERN_SUCCESS) { 974 error = ENOMEM; 975 goto out; 976 } 977 #endif 978 } 979 980 #ifdef GPROF 981 /* Update profiling information with the new text segment. */ 982 mtx_lock(&Giant); 983 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 984 segs[0]->p_memsz)); 985 mtx_unlock(&Giant); 986 #endif 987 988 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 989 990 lf->address = ef->address; 991 lf->size = mapsize; 992 993 error = parse_dynamic(ef); 994 if (error != 0) 995 goto out; 996 error = parse_dpcpu(ef); 997 if (error != 0) 998 goto out; 999 #ifdef VIMAGE 1000 error = parse_vnet(ef); 1001 if (error != 0) 1002 goto out; 1003 #endif 1004 link_elf_reloc_local(lf); 1005 1006 VOP_UNLOCK(nd.ni_vp, 0); 1007 error = linker_load_dependencies(lf); 1008 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 1009 if (error != 0) 1010 goto out; 1011 error = relocate_file(ef); 1012 if (error != 0) 1013 goto out; 1014 1015 /* 1016 * Try and load the symbol table if it's present. (you can 1017 * strip it!) 1018 */ 1019 nbytes = hdr->e_shnum * hdr->e_shentsize; 1020 if (nbytes == 0 || hdr->e_shoff == 0) 1021 goto nosyms; 1022 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1023 error = vn_rdwr(UIO_READ, nd.ni_vp, 1024 (caddr_t)shdr, nbytes, hdr->e_shoff, 1025 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1026 &resid, td); 1027 if (error != 0) 1028 goto out; 1029 1030 /* Read section string table */ 1031 shstrindex = hdr->e_shstrndx; 1032 if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB && 1033 shdr[shstrindex].sh_size != 0) { 1034 nbytes = shdr[shstrindex].sh_size; 1035 shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1036 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes, 1037 shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 1038 td->td_ucred, NOCRED, &resid, td); 1039 if (error) 1040 goto out; 1041 } 1042 1043 symtabindex = -1; 1044 symstrindex = -1; 1045 for (i = 0; i < hdr->e_shnum; i++) { 1046 if (shdr[i].sh_type == SHT_SYMTAB) { 1047 symtabindex = i; 1048 symstrindex = shdr[i].sh_link; 1049 } else if (shstrs != NULL && shdr[i].sh_name != 0 && 1050 strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) { 1051 /* Record relocated address and size of .ctors. */ 1052 lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr; 1053 lf->ctors_size = shdr[i].sh_size; 1054 } 1055 } 1056 if (symtabindex < 0 || symstrindex < 0) 1057 goto nosyms; 1058 1059 symcnt = shdr[symtabindex].sh_size; 1060 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1061 strcnt = shdr[symstrindex].sh_size; 1062 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1063 1064 error = vn_rdwr(UIO_READ, nd.ni_vp, 1065 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1066 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1067 &resid, td); 1068 if (error != 0) 1069 goto out; 1070 error = vn_rdwr(UIO_READ, nd.ni_vp, 1071 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1072 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1073 &resid, td); 1074 if (error != 0) 1075 goto out; 1076 1077 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1078 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1079 ef->ddbstrcnt = strcnt; 1080 ef->ddbstrtab = ef->strbase; 1081 1082 nosyms: 1083 error = link_elf_link_common_finish(lf); 1084 if (error != 0) 1085 goto out; 1086 1087 *result = lf; 1088 1089 out: 1090 VOP_UNLOCK(nd.ni_vp, 0); 1091 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1092 if (error != 0 && lf != NULL) 1093 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1094 if (shdr != NULL) 1095 free(shdr, M_LINKER); 1096 if (firstpage != NULL) 1097 free(firstpage, M_LINKER); 1098 if (shstrs != NULL) 1099 free(shstrs, M_LINKER); 1100 1101 return (error); 1102 } 1103 1104 Elf_Addr 1105 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1106 { 1107 elf_file_t ef; 1108 1109 ef = (elf_file_t)lf; 1110 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1111 return ((x - ef->pcpu_start) + ef->pcpu_base); 1112 #ifdef VIMAGE 1113 if (x >= ef->vnet_start && x < ef->vnet_stop) 1114 return ((x - ef->vnet_start) + ef->vnet_base); 1115 #endif 1116 return (x); 1117 } 1118 1119 1120 static void 1121 link_elf_unload_file(linker_file_t file) 1122 { 1123 elf_file_t ef = (elf_file_t) file; 1124 1125 if (ef->pcpu_base != 0) { 1126 dpcpu_free((void *)ef->pcpu_base, 1127 ef->pcpu_stop - ef->pcpu_start); 1128 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1129 } 1130 #ifdef VIMAGE 1131 if (ef->vnet_base != 0) { 1132 vnet_data_free((void *)ef->vnet_base, 1133 ef->vnet_stop - ef->vnet_start); 1134 elf_set_delete(&set_vnet_list, ef->vnet_start); 1135 } 1136 #endif 1137 #ifdef GDB 1138 if (ef->gdb.l_ld != NULL) { 1139 GDB_STATE(RT_DELETE); 1140 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1141 link_elf_delete_gdb(&ef->gdb); 1142 GDB_STATE(RT_CONSISTENT); 1143 } 1144 #endif 1145 1146 /* Notify MD code that a module is being unloaded. */ 1147 elf_cpu_unload_file(file); 1148 1149 if (ef->preloaded) { 1150 link_elf_unload_preload(file); 1151 return; 1152 } 1153 1154 #ifdef SPARSE_MAPPING 1155 if (ef->object != NULL) { 1156 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1157 (vm_offset_t) ef->address 1158 + (ef->object->size << PAGE_SHIFT)); 1159 } 1160 #else 1161 if (ef->address != NULL) 1162 free(ef->address, M_LINKER); 1163 #endif 1164 if (ef->symbase != NULL) 1165 free(ef->symbase, M_LINKER); 1166 if (ef->strbase != NULL) 1167 free(ef->strbase, M_LINKER); 1168 if (ef->ctftab != NULL) 1169 free(ef->ctftab, M_LINKER); 1170 if (ef->ctfoff != NULL) 1171 free(ef->ctfoff, M_LINKER); 1172 if (ef->typoff != NULL) 1173 free(ef->typoff, M_LINKER); 1174 } 1175 1176 static void 1177 link_elf_unload_preload(linker_file_t file) 1178 { 1179 if (file->filename != NULL) 1180 preload_delete_name(file->filename); 1181 } 1182 1183 static const char * 1184 symbol_name(elf_file_t ef, Elf_Size r_info) 1185 { 1186 const Elf_Sym *ref; 1187 1188 if (ELF_R_SYM(r_info)) { 1189 ref = ef->symtab + ELF_R_SYM(r_info); 1190 return (ef->strtab + ref->st_name); 1191 } 1192 return (NULL); 1193 } 1194 1195 static int 1196 relocate_file(elf_file_t ef) 1197 { 1198 const Elf_Rel *rellim; 1199 const Elf_Rel *rel; 1200 const Elf_Rela *relalim; 1201 const Elf_Rela *rela; 1202 const char *symname; 1203 1204 /* Perform relocations without addend if there are any: */ 1205 rel = ef->rel; 1206 if (rel != NULL) { 1207 rellim = (const Elf_Rel *) 1208 ((const char *)ef->rel + ef->relsize); 1209 while (rel < rellim) { 1210 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1211 ELF_RELOC_REL, elf_lookup)) { 1212 symname = symbol_name(ef, rel->r_info); 1213 printf("link_elf: symbol %s undefined\n", symname); 1214 return (ENOENT); 1215 } 1216 rel++; 1217 } 1218 } 1219 1220 /* Perform relocations with addend if there are any: */ 1221 rela = ef->rela; 1222 if (rela != NULL) { 1223 relalim = (const Elf_Rela *) 1224 ((const char *)ef->rela + ef->relasize); 1225 while (rela < relalim) { 1226 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1227 ELF_RELOC_RELA, elf_lookup)) { 1228 symname = symbol_name(ef, rela->r_info); 1229 printf("link_elf: symbol %s undefined\n", 1230 symname); 1231 return (ENOENT); 1232 } 1233 rela++; 1234 } 1235 } 1236 1237 /* Perform PLT relocations without addend if there are any: */ 1238 rel = ef->pltrel; 1239 if (rel != NULL) { 1240 rellim = (const Elf_Rel *) 1241 ((const char *)ef->pltrel + ef->pltrelsize); 1242 while (rel < rellim) { 1243 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1244 ELF_RELOC_REL, elf_lookup)) { 1245 symname = symbol_name(ef, rel->r_info); 1246 printf("link_elf: symbol %s undefined\n", 1247 symname); 1248 return (ENOENT); 1249 } 1250 rel++; 1251 } 1252 } 1253 1254 /* Perform relocations with addend if there are any: */ 1255 rela = ef->pltrela; 1256 if (rela != NULL) { 1257 relalim = (const Elf_Rela *) 1258 ((const char *)ef->pltrela + ef->pltrelasize); 1259 while (rela < relalim) { 1260 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1261 ELF_RELOC_RELA, elf_lookup)) { 1262 symname = symbol_name(ef, rela->r_info); 1263 printf("link_elf: symbol %s undefined\n", 1264 symname); 1265 return (ENOENT); 1266 } 1267 rela++; 1268 } 1269 } 1270 1271 return (0); 1272 } 1273 1274 /* 1275 * Hash function for symbol table lookup. Don't even think about changing 1276 * this. It is specified by the System V ABI. 1277 */ 1278 static unsigned long 1279 elf_hash(const char *name) 1280 { 1281 const unsigned char *p = (const unsigned char *) name; 1282 unsigned long h = 0; 1283 unsigned long g; 1284 1285 while (*p != '\0') { 1286 h = (h << 4) + *p++; 1287 if ((g = h & 0xf0000000) != 0) 1288 h ^= g >> 24; 1289 h &= ~g; 1290 } 1291 return (h); 1292 } 1293 1294 static int 1295 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1296 { 1297 elf_file_t ef = (elf_file_t) lf; 1298 unsigned long symnum; 1299 const Elf_Sym* symp; 1300 const char *strp; 1301 unsigned long hash; 1302 int i; 1303 1304 /* If we don't have a hash, bail. */ 1305 if (ef->buckets == NULL || ef->nbuckets == 0) { 1306 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1307 return (ENOENT); 1308 } 1309 1310 /* First, search hashed global symbols */ 1311 hash = elf_hash(name); 1312 symnum = ef->buckets[hash % ef->nbuckets]; 1313 1314 while (symnum != STN_UNDEF) { 1315 if (symnum >= ef->nchains) { 1316 printf("%s: corrupt symbol table\n", __func__); 1317 return (ENOENT); 1318 } 1319 1320 symp = ef->symtab + symnum; 1321 if (symp->st_name == 0) { 1322 printf("%s: corrupt symbol table\n", __func__); 1323 return (ENOENT); 1324 } 1325 1326 strp = ef->strtab + symp->st_name; 1327 1328 if (strcmp(name, strp) == 0) { 1329 if (symp->st_shndx != SHN_UNDEF || 1330 (symp->st_value != 0 && 1331 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1332 *sym = (c_linker_sym_t) symp; 1333 return (0); 1334 } 1335 return (ENOENT); 1336 } 1337 1338 symnum = ef->chains[symnum]; 1339 } 1340 1341 /* If we have not found it, look at the full table (if loaded) */ 1342 if (ef->symtab == ef->ddbsymtab) 1343 return (ENOENT); 1344 1345 /* Exhaustive search */ 1346 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1347 strp = ef->ddbstrtab + symp->st_name; 1348 if (strcmp(name, strp) == 0) { 1349 if (symp->st_shndx != SHN_UNDEF || 1350 (symp->st_value != 0 && 1351 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1352 *sym = (c_linker_sym_t) symp; 1353 return (0); 1354 } 1355 return (ENOENT); 1356 } 1357 } 1358 1359 return (ENOENT); 1360 } 1361 1362 static int 1363 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1364 linker_symval_t *symval) 1365 { 1366 elf_file_t ef = (elf_file_t) lf; 1367 const Elf_Sym* es = (const Elf_Sym*) sym; 1368 1369 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1370 symval->name = ef->strtab + es->st_name; 1371 symval->value = (caddr_t) ef->address + es->st_value; 1372 symval->size = es->st_size; 1373 return (0); 1374 } 1375 if (ef->symtab == ef->ddbsymtab) 1376 return (ENOENT); 1377 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1378 symval->name = ef->ddbstrtab + es->st_name; 1379 symval->value = (caddr_t) ef->address + es->st_value; 1380 symval->size = es->st_size; 1381 return (0); 1382 } 1383 return (ENOENT); 1384 } 1385 1386 static int 1387 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1388 c_linker_sym_t *sym, long *diffp) 1389 { 1390 elf_file_t ef = (elf_file_t) lf; 1391 u_long off = (uintptr_t) (void *) value; 1392 u_long diff = off; 1393 u_long st_value; 1394 const Elf_Sym* es; 1395 const Elf_Sym* best = 0; 1396 int i; 1397 1398 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1399 if (es->st_name == 0) 1400 continue; 1401 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1402 if (off >= st_value) { 1403 if (off - st_value < diff) { 1404 diff = off - st_value; 1405 best = es; 1406 if (diff == 0) 1407 break; 1408 } else if (off - st_value == diff) { 1409 best = es; 1410 } 1411 } 1412 } 1413 if (best == 0) 1414 *diffp = off; 1415 else 1416 *diffp = diff; 1417 *sym = (c_linker_sym_t) best; 1418 1419 return (0); 1420 } 1421 1422 /* 1423 * Look up a linker set on an ELF system. 1424 */ 1425 static int 1426 link_elf_lookup_set(linker_file_t lf, const char *name, 1427 void ***startp, void ***stopp, int *countp) 1428 { 1429 c_linker_sym_t sym; 1430 linker_symval_t symval; 1431 char *setsym; 1432 void **start, **stop; 1433 int len, error = 0, count; 1434 1435 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1436 setsym = malloc(len, M_LINKER, M_WAITOK); 1437 1438 /* get address of first entry */ 1439 snprintf(setsym, len, "%s%s", "__start_set_", name); 1440 error = link_elf_lookup_symbol(lf, setsym, &sym); 1441 if (error != 0) 1442 goto out; 1443 link_elf_symbol_values(lf, sym, &symval); 1444 if (symval.value == 0) { 1445 error = ESRCH; 1446 goto out; 1447 } 1448 start = (void **)symval.value; 1449 1450 /* get address of last entry */ 1451 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1452 error = link_elf_lookup_symbol(lf, setsym, &sym); 1453 if (error != 0) 1454 goto out; 1455 link_elf_symbol_values(lf, sym, &symval); 1456 if (symval.value == 0) { 1457 error = ESRCH; 1458 goto out; 1459 } 1460 stop = (void **)symval.value; 1461 1462 /* and the number of entries */ 1463 count = stop - start; 1464 1465 /* and copy out */ 1466 if (startp != NULL) 1467 *startp = start; 1468 if (stopp != NULL) 1469 *stopp = stop; 1470 if (countp != NULL) 1471 *countp = count; 1472 1473 out: 1474 free(setsym, M_LINKER); 1475 return (error); 1476 } 1477 1478 static int 1479 link_elf_each_function_name(linker_file_t file, 1480 int (*callback)(const char *, void *), void *opaque) 1481 { 1482 elf_file_t ef = (elf_file_t)file; 1483 const Elf_Sym *symp; 1484 int i, error; 1485 1486 /* Exhaustive search */ 1487 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1488 if (symp->st_value != 0 && 1489 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1490 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1491 if (error != 0) 1492 return (error); 1493 } 1494 } 1495 return (0); 1496 } 1497 1498 static int 1499 link_elf_each_function_nameval(linker_file_t file, 1500 linker_function_nameval_callback_t callback, void *opaque) 1501 { 1502 linker_symval_t symval; 1503 elf_file_t ef = (elf_file_t)file; 1504 const Elf_Sym* symp; 1505 int i, error; 1506 1507 /* Exhaustive search */ 1508 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1509 if (symp->st_value != 0 && 1510 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1511 error = link_elf_symbol_values(file, 1512 (c_linker_sym_t) symp, &symval); 1513 if (error != 0) 1514 return (error); 1515 error = callback(file, i, &symval, opaque); 1516 if (error != 0) 1517 return (error); 1518 } 1519 } 1520 return (0); 1521 } 1522 1523 const Elf_Sym * 1524 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1525 { 1526 elf_file_t ef = (elf_file_t)lf; 1527 1528 if (symidx >= ef->nchains) 1529 return (NULL); 1530 return (ef->symtab + symidx); 1531 } 1532 1533 const char * 1534 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1535 { 1536 elf_file_t ef = (elf_file_t)lf; 1537 const Elf_Sym *sym; 1538 1539 if (symidx >= ef->nchains) 1540 return (NULL); 1541 sym = ef->symtab + symidx; 1542 return (ef->strtab + sym->st_name); 1543 } 1544 1545 /* 1546 * Symbol lookup function that can be used when the symbol index is known (ie 1547 * in relocations). It uses the symbol index instead of doing a fully fledged 1548 * hash table based lookup when such is valid. For example for local symbols. 1549 * This is not only more efficient, it's also more correct. It's not always 1550 * the case that the symbol can be found through the hash table. 1551 */ 1552 static Elf_Addr 1553 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1554 { 1555 elf_file_t ef = (elf_file_t)lf; 1556 const Elf_Sym *sym; 1557 const char *symbol; 1558 Elf_Addr addr, start, base; 1559 1560 /* Don't even try to lookup the symbol if the index is bogus. */ 1561 if (symidx >= ef->nchains) 1562 return (0); 1563 1564 sym = ef->symtab + symidx; 1565 1566 /* 1567 * Don't do a full lookup when the symbol is local. It may even 1568 * fail because it may not be found through the hash table. 1569 */ 1570 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1571 /* Force lookup failure when we have an insanity. */ 1572 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) 1573 return (0); 1574 return ((Elf_Addr)ef->address + sym->st_value); 1575 } 1576 1577 /* 1578 * XXX we can avoid doing a hash table based lookup for global 1579 * symbols as well. This however is not always valid, so we'll 1580 * just do it the hard way for now. Performance tweaks can 1581 * always be added. 1582 */ 1583 1584 symbol = ef->strtab + sym->st_name; 1585 1586 /* Force a lookup failure if the symbol name is bogus. */ 1587 if (*symbol == 0) 1588 return (0); 1589 1590 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1591 1592 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1593 addr = addr - start + base; 1594 #ifdef VIMAGE 1595 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1596 addr = addr - start + base; 1597 #endif 1598 return addr; 1599 } 1600 1601 static void 1602 link_elf_reloc_local(linker_file_t lf) 1603 { 1604 const Elf_Rel *rellim; 1605 const Elf_Rel *rel; 1606 const Elf_Rela *relalim; 1607 const Elf_Rela *rela; 1608 elf_file_t ef = (elf_file_t)lf; 1609 1610 /* Perform relocations without addend if there are any: */ 1611 if ((rel = ef->rel) != NULL) { 1612 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1613 while (rel < rellim) { 1614 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1615 ELF_RELOC_REL, elf_lookup); 1616 rel++; 1617 } 1618 } 1619 1620 /* Perform relocations with addend if there are any: */ 1621 if ((rela = ef->rela) != NULL) { 1622 relalim = (const Elf_Rela *) 1623 ((const char *)ef->rela + ef->relasize); 1624 while (rela < relalim) { 1625 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1626 ELF_RELOC_RELA, elf_lookup); 1627 rela++; 1628 } 1629 } 1630 } 1631 1632 static long 1633 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1634 { 1635 elf_file_t ef = (elf_file_t)lf; 1636 1637 *symtab = ef->ddbsymtab; 1638 1639 if (*symtab == NULL) 1640 return (0); 1641 1642 return (ef->ddbsymcnt); 1643 } 1644 1645 static long 1646 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1647 { 1648 elf_file_t ef = (elf_file_t)lf; 1649 1650 *strtab = ef->ddbstrtab; 1651 1652 if (*strtab == NULL) 1653 return (0); 1654 1655 return (ef->ddbstrcnt); 1656 } 1657