1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998-2000 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_ddb.h" 33 #include "opt_gdb.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #ifdef GPROF 38 #include <sys/gmon.h> 39 #endif 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/mutex.h> 44 #include <sys/mount.h> 45 #include <sys/pcpu.h> 46 #include <sys/proc.h> 47 #include <sys/namei.h> 48 #include <sys/fcntl.h> 49 #include <sys/vnode.h> 50 #include <sys/linker.h> 51 52 #include <machine/elf.h> 53 54 #include <net/vnet.h> 55 56 #include <security/mac/mac_framework.h> 57 58 #include <vm/vm.h> 59 #include <vm/vm_param.h> 60 #ifdef SPARSE_MAPPING 61 #include <vm/vm_object.h> 62 #include <vm/vm_kern.h> 63 #include <vm/vm_extern.h> 64 #endif 65 #include <vm/pmap.h> 66 #include <vm/vm_map.h> 67 68 #include <sys/link_elf.h> 69 70 #ifdef DDB_CTF 71 #include <sys/zlib.h> 72 #endif 73 74 #include "linker_if.h" 75 76 #define MAXSEGS 4 77 78 typedef struct elf_file { 79 struct linker_file lf; /* Common fields */ 80 int preloaded; /* Was file pre-loaded */ 81 caddr_t address; /* Relocation address */ 82 #ifdef SPARSE_MAPPING 83 vm_object_t object; /* VM object to hold file pages */ 84 #endif 85 Elf_Dyn *dynamic; /* Symbol table etc. */ 86 Elf_Hashelt nbuckets; /* DT_HASH info */ 87 Elf_Hashelt nchains; 88 const Elf_Hashelt *buckets; 89 const Elf_Hashelt *chains; 90 caddr_t hash; 91 caddr_t strtab; /* DT_STRTAB */ 92 int strsz; /* DT_STRSZ */ 93 const Elf_Sym *symtab; /* DT_SYMTAB */ 94 Elf_Addr *got; /* DT_PLTGOT */ 95 const Elf_Rel *pltrel; /* DT_JMPREL */ 96 int pltrelsize; /* DT_PLTRELSZ */ 97 const Elf_Rela *pltrela; /* DT_JMPREL */ 98 int pltrelasize; /* DT_PLTRELSZ */ 99 const Elf_Rel *rel; /* DT_REL */ 100 int relsize; /* DT_RELSZ */ 101 const Elf_Rela *rela; /* DT_RELA */ 102 int relasize; /* DT_RELASZ */ 103 caddr_t modptr; 104 const Elf_Sym *ddbsymtab; /* The symbol table we are using */ 105 long ddbsymcnt; /* Number of symbols */ 106 caddr_t ddbstrtab; /* String table */ 107 long ddbstrcnt; /* number of bytes in string table */ 108 caddr_t symbase; /* malloc'ed symbold base */ 109 caddr_t strbase; /* malloc'ed string base */ 110 caddr_t ctftab; /* CTF table */ 111 long ctfcnt; /* number of bytes in CTF table */ 112 caddr_t ctfoff; /* CTF offset table */ 113 caddr_t typoff; /* Type offset table */ 114 long typlen; /* Number of type entries. */ 115 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */ 116 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */ 117 Elf_Addr pcpu_base; /* Relocated pcpu set address. */ 118 #ifdef VIMAGE 119 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */ 120 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */ 121 Elf_Addr vnet_base; /* Relocated vnet set address. */ 122 #endif 123 #ifdef GDB 124 struct link_map gdb; /* hooks for gdb */ 125 #endif 126 } *elf_file_t; 127 128 struct elf_set { 129 Elf_Addr es_start; 130 Elf_Addr es_stop; 131 Elf_Addr es_base; 132 TAILQ_ENTRY(elf_set) es_link; 133 }; 134 135 TAILQ_HEAD(elf_set_head, elf_set); 136 137 #include <kern/kern_ctf.c> 138 139 static int link_elf_link_common_finish(linker_file_t); 140 static int link_elf_link_preload(linker_class_t cls, 141 const char *, linker_file_t *); 142 static int link_elf_link_preload_finish(linker_file_t); 143 static int link_elf_load_file(linker_class_t, const char *, 144 linker_file_t *); 145 static int link_elf_lookup_symbol(linker_file_t, const char *, 146 c_linker_sym_t *); 147 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 148 linker_symval_t *); 149 static int link_elf_search_symbol(linker_file_t, caddr_t, 150 c_linker_sym_t *, long *); 151 152 static void link_elf_unload_file(linker_file_t); 153 static void link_elf_unload_preload(linker_file_t); 154 static int link_elf_lookup_set(linker_file_t, const char *, 155 void ***, void ***, int *); 156 static int link_elf_each_function_name(linker_file_t, 157 int (*)(const char *, void *), void *); 158 static int link_elf_each_function_nameval(linker_file_t, 159 linker_function_nameval_callback_t, void *); 160 static void link_elf_reloc_local(linker_file_t); 161 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 162 static long link_elf_strtab_get(linker_file_t, caddr_t *); 163 static int elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *); 164 165 static kobj_method_t link_elf_methods[] = { 166 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 167 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 168 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 169 KOBJMETHOD(linker_unload, link_elf_unload_file), 170 KOBJMETHOD(linker_load_file, link_elf_load_file), 171 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 172 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 173 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 174 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 175 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 176 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 177 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 178 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 179 { 0, 0 } 180 }; 181 182 static struct linker_class link_elf_class = { 183 #if ELF_TARG_CLASS == ELFCLASS32 184 "elf32", 185 #else 186 "elf64", 187 #endif 188 link_elf_methods, sizeof(struct elf_file) 189 }; 190 191 static int parse_dynamic(elf_file_t); 192 static int relocate_file(elf_file_t); 193 static int relocate_file1(elf_file_t ef, int (*elf_reloc_func)( 194 linker_file_t lf, Elf_Addr relocbase, const void *data, 195 int type, elf_lookup_fn lookup)); 196 static int link_elf_preload_parse_symbols(elf_file_t); 197 198 static struct elf_set_head set_pcpu_list; 199 #ifdef VIMAGE 200 static struct elf_set_head set_vnet_list; 201 #endif 202 203 static void 204 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base) 205 { 206 struct elf_set *set, *iter; 207 208 set = malloc(sizeof(*set), M_LINKER, M_WAITOK); 209 set->es_start = start; 210 set->es_stop = stop; 211 set->es_base = base; 212 213 TAILQ_FOREACH(iter, list, es_link) { 214 215 KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) || 216 (set->es_start > iter->es_start && set->es_stop > iter->es_stop), 217 ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx", 218 (uintmax_t)set->es_start, (uintmax_t)set->es_stop, 219 (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop)); 220 221 if (iter->es_start > set->es_start) { 222 TAILQ_INSERT_BEFORE(iter, set, es_link); 223 break; 224 } 225 } 226 227 if (iter == NULL) 228 TAILQ_INSERT_TAIL(list, set, es_link); 229 } 230 231 static int 232 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base) 233 { 234 struct elf_set *set; 235 236 TAILQ_FOREACH(set, list, es_link) { 237 if (addr < set->es_start) 238 return (0); 239 if (addr < set->es_stop) { 240 *start = set->es_start; 241 *base = set->es_base; 242 return (1); 243 } 244 } 245 246 return (0); 247 } 248 249 static void 250 elf_set_delete(struct elf_set_head *list, Elf_Addr start) 251 { 252 struct elf_set *set; 253 254 TAILQ_FOREACH(set, list, es_link) { 255 if (start < set->es_start) 256 break; 257 if (start == set->es_start) { 258 TAILQ_REMOVE(list, set, es_link); 259 free(set, M_LINKER); 260 return; 261 } 262 } 263 KASSERT(0, ("deleting unknown linker set (start = 0x%jx)", 264 (uintmax_t)start)); 265 } 266 267 #ifdef GDB 268 static void r_debug_state(struct r_debug *, struct link_map *); 269 270 /* 271 * A list of loaded modules for GDB to use for loading symbols. 272 */ 273 struct r_debug r_debug; 274 275 #define GDB_STATE(s) do { \ 276 r_debug.r_state = s; r_debug_state(NULL, NULL); \ 277 } while (0) 278 279 /* 280 * Function for the debugger to set a breakpoint on to gain control. 281 */ 282 static void 283 r_debug_state(struct r_debug *dummy_one __unused, 284 struct link_map *dummy_two __unused) 285 { 286 } 287 288 static void 289 link_elf_add_gdb(struct link_map *l) 290 { 291 struct link_map *prev; 292 293 l->l_next = NULL; 294 295 if (r_debug.r_map == NULL) { 296 /* Add first. */ 297 l->l_prev = NULL; 298 r_debug.r_map = l; 299 } else { 300 /* Append to list. */ 301 for (prev = r_debug.r_map; 302 prev->l_next != NULL; 303 prev = prev->l_next) 304 ; 305 l->l_prev = prev; 306 prev->l_next = l; 307 } 308 } 309 310 static void 311 link_elf_delete_gdb(struct link_map *l) 312 { 313 if (l->l_prev == NULL) { 314 /* Remove first. */ 315 if ((r_debug.r_map = l->l_next) != NULL) 316 l->l_next->l_prev = NULL; 317 } else { 318 /* Remove any but first. */ 319 if ((l->l_prev->l_next = l->l_next) != NULL) 320 l->l_next->l_prev = l->l_prev; 321 } 322 } 323 #endif /* GDB */ 324 325 /* 326 * The kernel symbol table starts here. 327 */ 328 extern struct _dynamic _DYNAMIC; 329 330 static void 331 link_elf_error(const char *filename, const char *s) 332 { 333 if (filename == NULL) 334 printf("kldload: %s\n", s); 335 else 336 printf("kldload: %s: %s\n", filename, s); 337 } 338 339 static void 340 link_elf_invoke_ctors(caddr_t addr, size_t size) 341 { 342 void (**ctor)(void); 343 size_t i, cnt; 344 345 if (addr == NULL || size == 0) 346 return; 347 cnt = size / sizeof(*ctor); 348 ctor = (void *)addr; 349 for (i = 0; i < cnt; i++) { 350 if (ctor[i] != NULL) 351 (*ctor[i])(); 352 } 353 } 354 355 /* 356 * Actions performed after linking/loading both the preloaded kernel and any 357 * modules; whether preloaded or dynamicly loaded. 358 */ 359 static int 360 link_elf_link_common_finish(linker_file_t lf) 361 { 362 #ifdef GDB 363 elf_file_t ef = (elf_file_t)lf; 364 char *newfilename; 365 #endif 366 int error; 367 368 /* Notify MD code that a module is being loaded. */ 369 error = elf_cpu_load_file(lf); 370 if (error != 0) 371 return (error); 372 373 #ifdef GDB 374 GDB_STATE(RT_ADD); 375 ef->gdb.l_addr = lf->address; 376 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 377 strcpy(newfilename, lf->filename); 378 ef->gdb.l_name = newfilename; 379 ef->gdb.l_ld = ef->dynamic; 380 link_elf_add_gdb(&ef->gdb); 381 GDB_STATE(RT_CONSISTENT); 382 #endif 383 384 /* Invoke .ctors */ 385 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 386 return (0); 387 } 388 389 extern vm_offset_t __startkernel, __endkernel; 390 391 static void 392 link_elf_init(void* arg) 393 { 394 Elf_Dyn *dp; 395 Elf_Addr *ctors_addrp; 396 Elf_Size *ctors_sizep; 397 caddr_t modptr, baseptr, sizeptr; 398 elf_file_t ef; 399 char *modname; 400 401 linker_add_class(&link_elf_class); 402 403 dp = (Elf_Dyn *)&_DYNAMIC; 404 modname = NULL; 405 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 406 if (modptr == NULL) 407 modptr = preload_search_by_type("elf kernel"); 408 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 409 if (modname == NULL) 410 modname = "kernel"; 411 linker_kernel_file = linker_make_file(modname, &link_elf_class); 412 if (linker_kernel_file == NULL) 413 panic("%s: Can't create linker structures for kernel", 414 __func__); 415 416 ef = (elf_file_t) linker_kernel_file; 417 ef->preloaded = 1; 418 #ifdef __powerpc__ 419 ef->address = (caddr_t) (__startkernel - KERNBASE); 420 #else 421 ef->address = 0; 422 #endif 423 #ifdef SPARSE_MAPPING 424 ef->object = 0; 425 #endif 426 ef->dynamic = dp; 427 428 if (dp != NULL) 429 parse_dynamic(ef); 430 #ifdef __powerpc__ 431 linker_kernel_file->address = (caddr_t)__startkernel; 432 linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel); 433 #else 434 linker_kernel_file->address += KERNBASE; 435 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 436 #endif 437 438 if (modptr != NULL) { 439 ef->modptr = modptr; 440 baseptr = preload_search_info(modptr, MODINFO_ADDR); 441 if (baseptr != NULL) 442 linker_kernel_file->address = *(caddr_t *)baseptr; 443 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 444 if (sizeptr != NULL) 445 linker_kernel_file->size = *(size_t *)sizeptr; 446 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 447 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 448 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 449 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 450 if (ctors_addrp != NULL && ctors_sizep != NULL) { 451 linker_kernel_file->ctors_addr = ef->address + 452 *ctors_addrp; 453 linker_kernel_file->ctors_size = *ctors_sizep; 454 } 455 } 456 (void)link_elf_preload_parse_symbols(ef); 457 458 #ifdef GDB 459 r_debug.r_map = NULL; 460 r_debug.r_brk = r_debug_state; 461 r_debug.r_state = RT_CONSISTENT; 462 #endif 463 464 (void)link_elf_link_common_finish(linker_kernel_file); 465 linker_kernel_file->flags |= LINKER_FILE_LINKED; 466 TAILQ_INIT(&set_pcpu_list); 467 #ifdef VIMAGE 468 TAILQ_INIT(&set_vnet_list); 469 #endif 470 } 471 472 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL); 473 474 static int 475 link_elf_preload_parse_symbols(elf_file_t ef) 476 { 477 caddr_t pointer; 478 caddr_t ssym, esym, base; 479 caddr_t strtab; 480 int strcnt; 481 Elf_Sym *symtab; 482 int symcnt; 483 484 if (ef->modptr == NULL) 485 return (0); 486 pointer = preload_search_info(ef->modptr, 487 MODINFO_METADATA | MODINFOMD_SSYM); 488 if (pointer == NULL) 489 return (0); 490 ssym = *(caddr_t *)pointer; 491 pointer = preload_search_info(ef->modptr, 492 MODINFO_METADATA | MODINFOMD_ESYM); 493 if (pointer == NULL) 494 return (0); 495 esym = *(caddr_t *)pointer; 496 497 base = ssym; 498 499 symcnt = *(long *)base; 500 base += sizeof(long); 501 symtab = (Elf_Sym *)base; 502 base += roundup(symcnt, sizeof(long)); 503 504 if (base > esym || base < ssym) { 505 printf("Symbols are corrupt!\n"); 506 return (EINVAL); 507 } 508 509 strcnt = *(long *)base; 510 base += sizeof(long); 511 strtab = base; 512 base += roundup(strcnt, sizeof(long)); 513 514 if (base > esym || base < ssym) { 515 printf("Symbols are corrupt!\n"); 516 return (EINVAL); 517 } 518 519 ef->ddbsymtab = symtab; 520 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 521 ef->ddbstrtab = strtab; 522 ef->ddbstrcnt = strcnt; 523 524 return (0); 525 } 526 527 static int 528 parse_dynamic(elf_file_t ef) 529 { 530 Elf_Dyn *dp; 531 int plttype = DT_REL; 532 533 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 534 switch (dp->d_tag) { 535 case DT_HASH: 536 { 537 /* From src/libexec/rtld-elf/rtld.c */ 538 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 539 (ef->address + dp->d_un.d_ptr); 540 ef->nbuckets = hashtab[0]; 541 ef->nchains = hashtab[1]; 542 ef->buckets = hashtab + 2; 543 ef->chains = ef->buckets + ef->nbuckets; 544 break; 545 } 546 case DT_STRTAB: 547 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 548 break; 549 case DT_STRSZ: 550 ef->strsz = dp->d_un.d_val; 551 break; 552 case DT_SYMTAB: 553 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 554 break; 555 case DT_SYMENT: 556 if (dp->d_un.d_val != sizeof(Elf_Sym)) 557 return (ENOEXEC); 558 break; 559 case DT_PLTGOT: 560 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 561 break; 562 case DT_REL: 563 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 564 break; 565 case DT_RELSZ: 566 ef->relsize = dp->d_un.d_val; 567 break; 568 case DT_RELENT: 569 if (dp->d_un.d_val != sizeof(Elf_Rel)) 570 return (ENOEXEC); 571 break; 572 case DT_JMPREL: 573 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 574 break; 575 case DT_PLTRELSZ: 576 ef->pltrelsize = dp->d_un.d_val; 577 break; 578 case DT_RELA: 579 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 580 break; 581 case DT_RELASZ: 582 ef->relasize = dp->d_un.d_val; 583 break; 584 case DT_RELAENT: 585 if (dp->d_un.d_val != sizeof(Elf_Rela)) 586 return (ENOEXEC); 587 break; 588 case DT_PLTREL: 589 plttype = dp->d_un.d_val; 590 if (plttype != DT_REL && plttype != DT_RELA) 591 return (ENOEXEC); 592 break; 593 #ifdef GDB 594 case DT_DEBUG: 595 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 596 break; 597 #endif 598 } 599 } 600 601 if (plttype == DT_RELA) { 602 ef->pltrela = (const Elf_Rela *)ef->pltrel; 603 ef->pltrel = NULL; 604 ef->pltrelasize = ef->pltrelsize; 605 ef->pltrelsize = 0; 606 } 607 608 ef->ddbsymtab = ef->symtab; 609 ef->ddbsymcnt = ef->nchains; 610 ef->ddbstrtab = ef->strtab; 611 ef->ddbstrcnt = ef->strsz; 612 613 return (0); 614 } 615 616 static int 617 parse_dpcpu(elf_file_t ef) 618 { 619 int count; 620 int error; 621 622 ef->pcpu_start = 0; 623 ef->pcpu_stop = 0; 624 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 625 (void ***)&ef->pcpu_stop, &count); 626 /* Error just means there is no pcpu set to relocate. */ 627 if (error != 0) 628 return (0); 629 count *= sizeof(void *); 630 /* 631 * Allocate space in the primary pcpu area. Copy in our 632 * initialization from the data section and then initialize 633 * all per-cpu storage from that. 634 */ 635 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count); 636 if (ef->pcpu_base == 0) 637 return (ENOSPC); 638 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count); 639 dpcpu_copy((void *)ef->pcpu_base, count); 640 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 641 ef->pcpu_base); 642 643 return (0); 644 } 645 646 #ifdef VIMAGE 647 static int 648 parse_vnet(elf_file_t ef) 649 { 650 int count; 651 int error; 652 653 ef->vnet_start = 0; 654 ef->vnet_stop = 0; 655 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 656 (void ***)&ef->vnet_stop, &count); 657 /* Error just means there is no vnet data set to relocate. */ 658 if (error != 0) 659 return (0); 660 count *= sizeof(void *); 661 /* 662 * Allocate space in the primary vnet area. Copy in our 663 * initialization from the data section and then initialize 664 * all per-vnet storage from that. 665 */ 666 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count); 667 if (ef->vnet_base == 0) 668 return (ENOSPC); 669 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count); 670 vnet_data_copy((void *)ef->vnet_base, count); 671 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 672 ef->vnet_base); 673 674 return (0); 675 } 676 #endif 677 678 static int 679 link_elf_link_preload(linker_class_t cls, 680 const char* filename, linker_file_t *result) 681 { 682 Elf_Addr *ctors_addrp; 683 Elf_Size *ctors_sizep; 684 caddr_t modptr, baseptr, sizeptr, dynptr; 685 char *type; 686 elf_file_t ef; 687 linker_file_t lf; 688 int error; 689 vm_offset_t dp; 690 691 /* Look to see if we have the file preloaded */ 692 modptr = preload_search_by_name(filename); 693 if (modptr == NULL) 694 return (ENOENT); 695 696 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 697 baseptr = preload_search_info(modptr, MODINFO_ADDR); 698 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 699 dynptr = preload_search_info(modptr, 700 MODINFO_METADATA | MODINFOMD_DYNAMIC); 701 if (type == NULL || 702 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 703 strcmp(type, "elf module") != 0)) 704 return (EFTYPE); 705 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 706 return (EINVAL); 707 708 lf = linker_make_file(filename, &link_elf_class); 709 if (lf == NULL) 710 return (ENOMEM); 711 712 ef = (elf_file_t) lf; 713 ef->preloaded = 1; 714 ef->modptr = modptr; 715 ef->address = *(caddr_t *)baseptr; 716 #ifdef SPARSE_MAPPING 717 ef->object = 0; 718 #endif 719 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 720 ef->dynamic = (Elf_Dyn *)dp; 721 lf->address = ef->address; 722 lf->size = *(size_t *)sizeptr; 723 724 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 725 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 726 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 727 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 728 if (ctors_addrp != NULL && ctors_sizep != NULL) { 729 lf->ctors_addr = ef->address + *ctors_addrp; 730 lf->ctors_size = *ctors_sizep; 731 } 732 733 error = parse_dynamic(ef); 734 if (error == 0) 735 error = parse_dpcpu(ef); 736 #ifdef VIMAGE 737 if (error == 0) 738 error = parse_vnet(ef); 739 #endif 740 if (error != 0) { 741 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 742 return (error); 743 } 744 link_elf_reloc_local(lf); 745 *result = lf; 746 return (0); 747 } 748 749 static int 750 link_elf_link_preload_finish(linker_file_t lf) 751 { 752 elf_file_t ef; 753 int error; 754 755 ef = (elf_file_t) lf; 756 error = relocate_file(ef); 757 if (error != 0) 758 return (error); 759 (void)link_elf_preload_parse_symbols(ef); 760 761 return (link_elf_link_common_finish(lf)); 762 } 763 764 static int 765 link_elf_load_file(linker_class_t cls, const char* filename, 766 linker_file_t* result) 767 { 768 struct nameidata nd; 769 struct thread* td = curthread; /* XXX */ 770 Elf_Ehdr *hdr; 771 caddr_t firstpage; 772 int nbytes, i; 773 Elf_Phdr *phdr; 774 Elf_Phdr *phlimit; 775 Elf_Phdr *segs[MAXSEGS]; 776 int nsegs; 777 Elf_Phdr *phdyn; 778 caddr_t mapbase; 779 size_t mapsize; 780 Elf_Addr base_vaddr; 781 Elf_Addr base_vlimit; 782 int error = 0; 783 ssize_t resid; 784 int flags; 785 elf_file_t ef; 786 linker_file_t lf; 787 Elf_Shdr *shdr; 788 int symtabindex; 789 int symstrindex; 790 int shstrindex; 791 int symcnt; 792 int strcnt; 793 char *shstrs; 794 795 shdr = NULL; 796 lf = NULL; 797 shstrs = NULL; 798 799 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 800 flags = FREAD; 801 error = vn_open(&nd, &flags, 0, NULL); 802 if (error != 0) 803 return (error); 804 NDFREE(&nd, NDF_ONLY_PNBUF); 805 if (nd.ni_vp->v_type != VREG) { 806 error = ENOEXEC; 807 firstpage = NULL; 808 goto out; 809 } 810 #ifdef MAC 811 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 812 if (error != 0) { 813 firstpage = NULL; 814 goto out; 815 } 816 #endif 817 818 /* 819 * Read the elf header from the file. 820 */ 821 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 822 hdr = (Elf_Ehdr *)firstpage; 823 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 824 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 825 &resid, td); 826 nbytes = PAGE_SIZE - resid; 827 if (error != 0) 828 goto out; 829 830 if (!IS_ELF(*hdr)) { 831 error = ENOEXEC; 832 goto out; 833 } 834 835 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 836 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 837 link_elf_error(filename, "Unsupported file layout"); 838 error = ENOEXEC; 839 goto out; 840 } 841 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 842 hdr->e_version != EV_CURRENT) { 843 link_elf_error(filename, "Unsupported file version"); 844 error = ENOEXEC; 845 goto out; 846 } 847 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 848 error = ENOSYS; 849 goto out; 850 } 851 if (hdr->e_machine != ELF_TARG_MACH) { 852 link_elf_error(filename, "Unsupported machine"); 853 error = ENOEXEC; 854 goto out; 855 } 856 857 /* 858 * We rely on the program header being in the first page. 859 * This is not strictly required by the ABI specification, but 860 * it seems to always true in practice. And, it simplifies 861 * things considerably. 862 */ 863 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 864 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 865 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 866 link_elf_error(filename, "Unreadable program headers"); 867 868 /* 869 * Scan the program header entries, and save key information. 870 * 871 * We rely on there being exactly two load segments, text and data, 872 * in that order. 873 */ 874 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 875 phlimit = phdr + hdr->e_phnum; 876 nsegs = 0; 877 phdyn = NULL; 878 while (phdr < phlimit) { 879 switch (phdr->p_type) { 880 case PT_LOAD: 881 if (nsegs == MAXSEGS) { 882 link_elf_error(filename, "Too many sections"); 883 error = ENOEXEC; 884 goto out; 885 } 886 /* 887 * XXX: We just trust they come in right order ?? 888 */ 889 segs[nsegs] = phdr; 890 ++nsegs; 891 break; 892 893 case PT_DYNAMIC: 894 phdyn = phdr; 895 break; 896 897 case PT_INTERP: 898 error = ENOSYS; 899 goto out; 900 } 901 902 ++phdr; 903 } 904 if (phdyn == NULL) { 905 link_elf_error(filename, "Object is not dynamically-linked"); 906 error = ENOEXEC; 907 goto out; 908 } 909 if (nsegs == 0) { 910 link_elf_error(filename, "No sections"); 911 error = ENOEXEC; 912 goto out; 913 } 914 915 /* 916 * Allocate the entire address space of the object, to stake 917 * out our contiguous region, and to establish the base 918 * address for relocation. 919 */ 920 base_vaddr = trunc_page(segs[0]->p_vaddr); 921 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 922 segs[nsegs - 1]->p_memsz); 923 mapsize = base_vlimit - base_vaddr; 924 925 lf = linker_make_file(filename, &link_elf_class); 926 if (lf == NULL) { 927 error = ENOMEM; 928 goto out; 929 } 930 931 ef = (elf_file_t) lf; 932 #ifdef SPARSE_MAPPING 933 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 934 if (ef->object == NULL) { 935 error = ENOMEM; 936 goto out; 937 } 938 ef->address = (caddr_t) vm_map_min(kernel_map); 939 error = vm_map_find(kernel_map, ef->object, 0, 940 (vm_offset_t *) &ef->address, mapsize, 0, VMFS_OPTIMAL_SPACE, 941 VM_PROT_ALL, VM_PROT_ALL, 0); 942 if (error != 0) { 943 vm_object_deallocate(ef->object); 944 ef->object = 0; 945 goto out; 946 } 947 #else 948 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 949 #endif 950 mapbase = ef->address; 951 952 /* 953 * Read the text and data sections and zero the bss. 954 */ 955 for (i = 0; i < nsegs; i++) { 956 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 957 error = vn_rdwr(UIO_READ, nd.ni_vp, 958 segbase, segs[i]->p_filesz, segs[i]->p_offset, 959 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 960 &resid, td); 961 if (error != 0) 962 goto out; 963 bzero(segbase + segs[i]->p_filesz, 964 segs[i]->p_memsz - segs[i]->p_filesz); 965 966 #ifdef SPARSE_MAPPING 967 /* 968 * Wire down the pages 969 */ 970 error = vm_map_wire(kernel_map, 971 (vm_offset_t) segbase, 972 (vm_offset_t) segbase + segs[i]->p_memsz, 973 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 974 if (error != KERN_SUCCESS) { 975 error = ENOMEM; 976 goto out; 977 } 978 #endif 979 } 980 981 #ifdef GPROF 982 /* Update profiling information with the new text segment. */ 983 mtx_lock(&Giant); 984 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 985 segs[0]->p_memsz)); 986 mtx_unlock(&Giant); 987 #endif 988 989 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 990 991 lf->address = ef->address; 992 lf->size = mapsize; 993 994 error = parse_dynamic(ef); 995 if (error != 0) 996 goto out; 997 error = parse_dpcpu(ef); 998 if (error != 0) 999 goto out; 1000 #ifdef VIMAGE 1001 error = parse_vnet(ef); 1002 if (error != 0) 1003 goto out; 1004 #endif 1005 link_elf_reloc_local(lf); 1006 1007 VOP_UNLOCK(nd.ni_vp, 0); 1008 error = linker_load_dependencies(lf); 1009 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 1010 if (error != 0) 1011 goto out; 1012 error = relocate_file(ef); 1013 if (error != 0) 1014 goto out; 1015 1016 /* 1017 * Try and load the symbol table if it's present. (you can 1018 * strip it!) 1019 */ 1020 nbytes = hdr->e_shnum * hdr->e_shentsize; 1021 if (nbytes == 0 || hdr->e_shoff == 0) 1022 goto nosyms; 1023 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1024 error = vn_rdwr(UIO_READ, nd.ni_vp, 1025 (caddr_t)shdr, nbytes, hdr->e_shoff, 1026 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1027 &resid, td); 1028 if (error != 0) 1029 goto out; 1030 1031 /* Read section string table */ 1032 shstrindex = hdr->e_shstrndx; 1033 if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB && 1034 shdr[shstrindex].sh_size != 0) { 1035 nbytes = shdr[shstrindex].sh_size; 1036 shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1037 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes, 1038 shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 1039 td->td_ucred, NOCRED, &resid, td); 1040 if (error) 1041 goto out; 1042 } 1043 1044 symtabindex = -1; 1045 symstrindex = -1; 1046 for (i = 0; i < hdr->e_shnum; i++) { 1047 if (shdr[i].sh_type == SHT_SYMTAB) { 1048 symtabindex = i; 1049 symstrindex = shdr[i].sh_link; 1050 } else if (shstrs != NULL && shdr[i].sh_name != 0 && 1051 strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) { 1052 /* Record relocated address and size of .ctors. */ 1053 lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr; 1054 lf->ctors_size = shdr[i].sh_size; 1055 } 1056 } 1057 if (symtabindex < 0 || symstrindex < 0) 1058 goto nosyms; 1059 1060 symcnt = shdr[symtabindex].sh_size; 1061 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1062 strcnt = shdr[symstrindex].sh_size; 1063 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1064 1065 error = vn_rdwr(UIO_READ, nd.ni_vp, 1066 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1067 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1068 &resid, td); 1069 if (error != 0) 1070 goto out; 1071 error = vn_rdwr(UIO_READ, nd.ni_vp, 1072 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1073 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1074 &resid, td); 1075 if (error != 0) 1076 goto out; 1077 1078 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1079 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1080 ef->ddbstrcnt = strcnt; 1081 ef->ddbstrtab = ef->strbase; 1082 1083 nosyms: 1084 error = link_elf_link_common_finish(lf); 1085 if (error != 0) 1086 goto out; 1087 1088 *result = lf; 1089 1090 out: 1091 VOP_UNLOCK(nd.ni_vp, 0); 1092 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1093 if (error != 0 && lf != NULL) 1094 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1095 free(shdr, M_LINKER); 1096 free(firstpage, M_LINKER); 1097 free(shstrs, M_LINKER); 1098 1099 return (error); 1100 } 1101 1102 Elf_Addr 1103 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1104 { 1105 elf_file_t ef; 1106 1107 ef = (elf_file_t)lf; 1108 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1109 return ((x - ef->pcpu_start) + ef->pcpu_base); 1110 #ifdef VIMAGE 1111 if (x >= ef->vnet_start && x < ef->vnet_stop) 1112 return ((x - ef->vnet_start) + ef->vnet_base); 1113 #endif 1114 return (x); 1115 } 1116 1117 1118 static void 1119 link_elf_unload_file(linker_file_t file) 1120 { 1121 elf_file_t ef = (elf_file_t) file; 1122 1123 if (ef->pcpu_base != 0) { 1124 dpcpu_free((void *)ef->pcpu_base, 1125 ef->pcpu_stop - ef->pcpu_start); 1126 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1127 } 1128 #ifdef VIMAGE 1129 if (ef->vnet_base != 0) { 1130 vnet_data_free((void *)ef->vnet_base, 1131 ef->vnet_stop - ef->vnet_start); 1132 elf_set_delete(&set_vnet_list, ef->vnet_start); 1133 } 1134 #endif 1135 #ifdef GDB 1136 if (ef->gdb.l_ld != NULL) { 1137 GDB_STATE(RT_DELETE); 1138 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1139 link_elf_delete_gdb(&ef->gdb); 1140 GDB_STATE(RT_CONSISTENT); 1141 } 1142 #endif 1143 1144 /* Notify MD code that a module is being unloaded. */ 1145 elf_cpu_unload_file(file); 1146 1147 if (ef->preloaded) { 1148 link_elf_unload_preload(file); 1149 return; 1150 } 1151 1152 #ifdef SPARSE_MAPPING 1153 if (ef->object != NULL) { 1154 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1155 (vm_offset_t) ef->address 1156 + (ef->object->size << PAGE_SHIFT)); 1157 } 1158 #else 1159 free(ef->address, M_LINKER); 1160 #endif 1161 free(ef->symbase, M_LINKER); 1162 free(ef->strbase, M_LINKER); 1163 free(ef->ctftab, M_LINKER); 1164 free(ef->ctfoff, M_LINKER); 1165 free(ef->typoff, M_LINKER); 1166 } 1167 1168 static void 1169 link_elf_unload_preload(linker_file_t file) 1170 { 1171 if (file->filename != NULL) 1172 preload_delete_name(file->filename); 1173 } 1174 1175 static const char * 1176 symbol_name(elf_file_t ef, Elf_Size r_info) 1177 { 1178 const Elf_Sym *ref; 1179 1180 if (ELF_R_SYM(r_info)) { 1181 ref = ef->symtab + ELF_R_SYM(r_info); 1182 return (ef->strtab + ref->st_name); 1183 } 1184 return (NULL); 1185 } 1186 1187 static int 1188 relocate_file1(elf_file_t ef, int (*elf_reloc_func)(linker_file_t lf, 1189 Elf_Addr relocbase, const void *data, int type, elf_lookup_fn lookup)) 1190 { 1191 const Elf_Rel *rellim; 1192 const Elf_Rel *rel; 1193 const Elf_Rela *relalim; 1194 const Elf_Rela *rela; 1195 const char *symname; 1196 1197 /* Perform relocations without addend if there are any: */ 1198 rel = ef->rel; 1199 if (rel != NULL) { 1200 rellim = (const Elf_Rel *) 1201 ((const char *)ef->rel + ef->relsize); 1202 while (rel < rellim) { 1203 if (elf_reloc_func(&ef->lf, (Elf_Addr)ef->address, rel, 1204 ELF_RELOC_REL, elf_lookup)) { 1205 symname = symbol_name(ef, rel->r_info); 1206 printf("link_elf: symbol %s undefined\n", symname); 1207 return (ENOENT); 1208 } 1209 rel++; 1210 } 1211 } 1212 1213 /* Perform relocations with addend if there are any: */ 1214 rela = ef->rela; 1215 if (rela != NULL) { 1216 relalim = (const Elf_Rela *) 1217 ((const char *)ef->rela + ef->relasize); 1218 while (rela < relalim) { 1219 if (elf_reloc_func(&ef->lf, (Elf_Addr)ef->address, rela, 1220 ELF_RELOC_RELA, elf_lookup)) { 1221 symname = symbol_name(ef, rela->r_info); 1222 printf("link_elf: symbol %s undefined\n", 1223 symname); 1224 return (ENOENT); 1225 } 1226 rela++; 1227 } 1228 } 1229 1230 /* Perform PLT relocations without addend if there are any: */ 1231 rel = ef->pltrel; 1232 if (rel != NULL) { 1233 rellim = (const Elf_Rel *) 1234 ((const char *)ef->pltrel + ef->pltrelsize); 1235 while (rel < rellim) { 1236 if (elf_reloc_func(&ef->lf, (Elf_Addr)ef->address, rel, 1237 ELF_RELOC_REL, elf_lookup)) { 1238 symname = symbol_name(ef, rel->r_info); 1239 printf("link_elf: symbol %s undefined\n", 1240 symname); 1241 return (ENOENT); 1242 } 1243 rel++; 1244 } 1245 } 1246 1247 /* Perform relocations with addend if there are any: */ 1248 rela = ef->pltrela; 1249 if (rela != NULL) { 1250 relalim = (const Elf_Rela *) 1251 ((const char *)ef->pltrela + ef->pltrelasize); 1252 while (rela < relalim) { 1253 if (elf_reloc_func(&ef->lf, (Elf_Addr)ef->address, rela, 1254 ELF_RELOC_RELA, elf_lookup)) { 1255 symname = symbol_name(ef, rela->r_info); 1256 printf("link_elf: symbol %s undefined\n", 1257 symname); 1258 return (ENOENT); 1259 } 1260 rela++; 1261 } 1262 } 1263 1264 return (0); 1265 } 1266 1267 static int 1268 relocate_file(elf_file_t ef) 1269 { 1270 int e; 1271 1272 e = relocate_file1(ef, elf_reloc); 1273 #if defined(__i386__) || defined(__amd64__) 1274 if (e == 0) 1275 e = relocate_file1(ef, elf_reloc_ifunc); 1276 #endif 1277 return (e); 1278 } 1279 1280 /* 1281 * Hash function for symbol table lookup. Don't even think about changing 1282 * this. It is specified by the System V ABI. 1283 */ 1284 static unsigned long 1285 elf_hash(const char *name) 1286 { 1287 const unsigned char *p = (const unsigned char *) name; 1288 unsigned long h = 0; 1289 unsigned long g; 1290 1291 while (*p != '\0') { 1292 h = (h << 4) + *p++; 1293 if ((g = h & 0xf0000000) != 0) 1294 h ^= g >> 24; 1295 h &= ~g; 1296 } 1297 return (h); 1298 } 1299 1300 static int 1301 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1302 { 1303 elf_file_t ef = (elf_file_t) lf; 1304 unsigned long symnum; 1305 const Elf_Sym* symp; 1306 const char *strp; 1307 unsigned long hash; 1308 int i; 1309 1310 /* If we don't have a hash, bail. */ 1311 if (ef->buckets == NULL || ef->nbuckets == 0) { 1312 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1313 return (ENOENT); 1314 } 1315 1316 /* First, search hashed global symbols */ 1317 hash = elf_hash(name); 1318 symnum = ef->buckets[hash % ef->nbuckets]; 1319 1320 while (symnum != STN_UNDEF) { 1321 if (symnum >= ef->nchains) { 1322 printf("%s: corrupt symbol table\n", __func__); 1323 return (ENOENT); 1324 } 1325 1326 symp = ef->symtab + symnum; 1327 if (symp->st_name == 0) { 1328 printf("%s: corrupt symbol table\n", __func__); 1329 return (ENOENT); 1330 } 1331 1332 strp = ef->strtab + symp->st_name; 1333 1334 if (strcmp(name, strp) == 0) { 1335 if (symp->st_shndx != SHN_UNDEF || 1336 (symp->st_value != 0 && 1337 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1338 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1339 *sym = (c_linker_sym_t) symp; 1340 return (0); 1341 } 1342 return (ENOENT); 1343 } 1344 1345 symnum = ef->chains[symnum]; 1346 } 1347 1348 /* If we have not found it, look at the full table (if loaded) */ 1349 if (ef->symtab == ef->ddbsymtab) 1350 return (ENOENT); 1351 1352 /* Exhaustive search */ 1353 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1354 strp = ef->ddbstrtab + symp->st_name; 1355 if (strcmp(name, strp) == 0) { 1356 if (symp->st_shndx != SHN_UNDEF || 1357 (symp->st_value != 0 && 1358 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1359 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1360 *sym = (c_linker_sym_t) symp; 1361 return (0); 1362 } 1363 return (ENOENT); 1364 } 1365 } 1366 1367 return (ENOENT); 1368 } 1369 1370 static int 1371 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1372 linker_symval_t *symval) 1373 { 1374 elf_file_t ef; 1375 const Elf_Sym *es; 1376 caddr_t val; 1377 1378 ef = (elf_file_t)lf; 1379 es = (const Elf_Sym *)sym; 1380 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1381 symval->name = ef->strtab + es->st_name; 1382 val = (caddr_t)ef->address + es->st_value; 1383 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1384 val = ((caddr_t (*)(void))val)(); 1385 symval->value = val; 1386 symval->size = es->st_size; 1387 return (0); 1388 } 1389 if (ef->symtab == ef->ddbsymtab) 1390 return (ENOENT); 1391 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1392 symval->name = ef->ddbstrtab + es->st_name; 1393 val = (caddr_t)ef->address + es->st_value; 1394 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1395 val = ((caddr_t (*)(void))val)(); 1396 symval->value = val; 1397 symval->size = es->st_size; 1398 return (0); 1399 } 1400 return (ENOENT); 1401 } 1402 1403 static int 1404 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1405 c_linker_sym_t *sym, long *diffp) 1406 { 1407 elf_file_t ef = (elf_file_t) lf; 1408 u_long off = (uintptr_t) (void *) value; 1409 u_long diff = off; 1410 u_long st_value; 1411 const Elf_Sym* es; 1412 const Elf_Sym* best = NULL; 1413 int i; 1414 1415 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1416 if (es->st_name == 0) 1417 continue; 1418 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1419 if (off >= st_value) { 1420 if (off - st_value < diff) { 1421 diff = off - st_value; 1422 best = es; 1423 if (diff == 0) 1424 break; 1425 } else if (off - st_value == diff) { 1426 best = es; 1427 } 1428 } 1429 } 1430 if (best == NULL) 1431 *diffp = off; 1432 else 1433 *diffp = diff; 1434 *sym = (c_linker_sym_t) best; 1435 1436 return (0); 1437 } 1438 1439 /* 1440 * Look up a linker set on an ELF system. 1441 */ 1442 static int 1443 link_elf_lookup_set(linker_file_t lf, const char *name, 1444 void ***startp, void ***stopp, int *countp) 1445 { 1446 c_linker_sym_t sym; 1447 linker_symval_t symval; 1448 char *setsym; 1449 void **start, **stop; 1450 int len, error = 0, count; 1451 1452 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1453 setsym = malloc(len, M_LINKER, M_WAITOK); 1454 1455 /* get address of first entry */ 1456 snprintf(setsym, len, "%s%s", "__start_set_", name); 1457 error = link_elf_lookup_symbol(lf, setsym, &sym); 1458 if (error != 0) 1459 goto out; 1460 link_elf_symbol_values(lf, sym, &symval); 1461 if (symval.value == 0) { 1462 error = ESRCH; 1463 goto out; 1464 } 1465 start = (void **)symval.value; 1466 1467 /* get address of last entry */ 1468 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1469 error = link_elf_lookup_symbol(lf, setsym, &sym); 1470 if (error != 0) 1471 goto out; 1472 link_elf_symbol_values(lf, sym, &symval); 1473 if (symval.value == 0) { 1474 error = ESRCH; 1475 goto out; 1476 } 1477 stop = (void **)symval.value; 1478 1479 /* and the number of entries */ 1480 count = stop - start; 1481 1482 /* and copy out */ 1483 if (startp != NULL) 1484 *startp = start; 1485 if (stopp != NULL) 1486 *stopp = stop; 1487 if (countp != NULL) 1488 *countp = count; 1489 1490 out: 1491 free(setsym, M_LINKER); 1492 return (error); 1493 } 1494 1495 static int 1496 link_elf_each_function_name(linker_file_t file, 1497 int (*callback)(const char *, void *), void *opaque) 1498 { 1499 elf_file_t ef = (elf_file_t)file; 1500 const Elf_Sym *symp; 1501 int i, error; 1502 1503 /* Exhaustive search */ 1504 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1505 if (symp->st_value != 0 && 1506 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1507 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1508 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1509 if (error != 0) 1510 return (error); 1511 } 1512 } 1513 return (0); 1514 } 1515 1516 static int 1517 link_elf_each_function_nameval(linker_file_t file, 1518 linker_function_nameval_callback_t callback, void *opaque) 1519 { 1520 linker_symval_t symval; 1521 elf_file_t ef = (elf_file_t)file; 1522 const Elf_Sym* symp; 1523 int i, error; 1524 1525 /* Exhaustive search */ 1526 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1527 if (symp->st_value != 0 && 1528 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1529 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1530 error = link_elf_symbol_values(file, 1531 (c_linker_sym_t) symp, &symval); 1532 if (error != 0) 1533 return (error); 1534 error = callback(file, i, &symval, opaque); 1535 if (error != 0) 1536 return (error); 1537 } 1538 } 1539 return (0); 1540 } 1541 1542 const Elf_Sym * 1543 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1544 { 1545 elf_file_t ef = (elf_file_t)lf; 1546 1547 if (symidx >= ef->nchains) 1548 return (NULL); 1549 return (ef->symtab + symidx); 1550 } 1551 1552 const char * 1553 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1554 { 1555 elf_file_t ef = (elf_file_t)lf; 1556 const Elf_Sym *sym; 1557 1558 if (symidx >= ef->nchains) 1559 return (NULL); 1560 sym = ef->symtab + symidx; 1561 return (ef->strtab + sym->st_name); 1562 } 1563 1564 /* 1565 * Symbol lookup function that can be used when the symbol index is known (ie 1566 * in relocations). It uses the symbol index instead of doing a fully fledged 1567 * hash table based lookup when such is valid. For example for local symbols. 1568 * This is not only more efficient, it's also more correct. It's not always 1569 * the case that the symbol can be found through the hash table. 1570 */ 1571 static int 1572 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1573 { 1574 elf_file_t ef = (elf_file_t)lf; 1575 const Elf_Sym *sym; 1576 const char *symbol; 1577 Elf_Addr addr, start, base; 1578 1579 /* Don't even try to lookup the symbol if the index is bogus. */ 1580 if (symidx >= ef->nchains) { 1581 *res = 0; 1582 return (EINVAL); 1583 } 1584 1585 sym = ef->symtab + symidx; 1586 1587 /* 1588 * Don't do a full lookup when the symbol is local. It may even 1589 * fail because it may not be found through the hash table. 1590 */ 1591 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1592 /* Force lookup failure when we have an insanity. */ 1593 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) { 1594 *res = 0; 1595 return (EINVAL); 1596 } 1597 *res = ((Elf_Addr)ef->address + sym->st_value); 1598 return (0); 1599 } 1600 1601 /* 1602 * XXX we can avoid doing a hash table based lookup for global 1603 * symbols as well. This however is not always valid, so we'll 1604 * just do it the hard way for now. Performance tweaks can 1605 * always be added. 1606 */ 1607 1608 symbol = ef->strtab + sym->st_name; 1609 1610 /* Force a lookup failure if the symbol name is bogus. */ 1611 if (*symbol == 0) { 1612 *res = 0; 1613 return (EINVAL); 1614 } 1615 1616 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1617 if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1618 *res = 0; 1619 return (EINVAL); 1620 } 1621 1622 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1623 addr = addr - start + base; 1624 #ifdef VIMAGE 1625 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1626 addr = addr - start + base; 1627 #endif 1628 *res = addr; 1629 return (0); 1630 } 1631 1632 static void 1633 link_elf_reloc_local(linker_file_t lf) 1634 { 1635 const Elf_Rel *rellim; 1636 const Elf_Rel *rel; 1637 const Elf_Rela *relalim; 1638 const Elf_Rela *rela; 1639 elf_file_t ef = (elf_file_t)lf; 1640 1641 /* Perform relocations without addend if there are any: */ 1642 if ((rel = ef->rel) != NULL) { 1643 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1644 while (rel < rellim) { 1645 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1646 ELF_RELOC_REL, elf_lookup); 1647 rel++; 1648 } 1649 } 1650 1651 /* Perform relocations with addend if there are any: */ 1652 if ((rela = ef->rela) != NULL) { 1653 relalim = (const Elf_Rela *) 1654 ((const char *)ef->rela + ef->relasize); 1655 while (rela < relalim) { 1656 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1657 ELF_RELOC_RELA, elf_lookup); 1658 rela++; 1659 } 1660 } 1661 } 1662 1663 static long 1664 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1665 { 1666 elf_file_t ef = (elf_file_t)lf; 1667 1668 *symtab = ef->ddbsymtab; 1669 1670 if (*symtab == NULL) 1671 return (0); 1672 1673 return (ef->ddbsymcnt); 1674 } 1675 1676 static long 1677 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1678 { 1679 elf_file_t ef = (elf_file_t)lf; 1680 1681 *strtab = ef->ddbstrtab; 1682 1683 if (*strtab == NULL) 1684 return (0); 1685 1686 return (ef->ddbstrcnt); 1687 } 1688 1689 #if defined(__i386__) || defined(__amd64__) 1690 void 1691 link_elf_ireloc(caddr_t kmdp) 1692 { 1693 struct elf_file eff; 1694 elf_file_t ef; 1695 volatile char *c; 1696 size_t i; 1697 1698 ef = &eff; 1699 1700 /* Do not use bzero/memset before ireloc is done. */ 1701 for (c = (char *)ef, i = 0; i < sizeof(*ef); i++) 1702 c[i] = 0; 1703 1704 ef->modptr = kmdp; 1705 ef->dynamic = (Elf_Dyn *)&_DYNAMIC; 1706 parse_dynamic(ef); 1707 ef->address = 0; 1708 link_elf_preload_parse_symbols(ef); 1709 relocate_file1(ef, elf_reloc_ifunc); 1710 } 1711 #endif 1712