link_elf.c revision 215013
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: head/sys/kern/link_elf.c 215013 2010-11-08 20:57:08Z mdf $"); 29 30#include "opt_ddb.h" 31#include "opt_gdb.h" 32 33#include <sys/param.h> 34#include <sys/systm.h> 35#ifdef GPROF 36#include <sys/gmon.h> 37#endif 38#include <sys/kernel.h> 39#include <sys/lock.h> 40#include <sys/malloc.h> 41#include <sys/mutex.h> 42#include <sys/mount.h> 43#include <sys/pcpu.h> 44#include <sys/proc.h> 45#include <sys/namei.h> 46#include <sys/fcntl.h> 47#include <sys/vnode.h> 48#include <sys/linker.h> 49 50#include <machine/elf.h> 51 52#include <net/vnet.h> 53 54#include <security/mac/mac_framework.h> 55 56#include <vm/vm.h> 57#include <vm/vm_param.h> 58#ifdef SPARSE_MAPPING 59#include <vm/vm_object.h> 60#include <vm/vm_kern.h> 61#include <vm/vm_extern.h> 62#endif 63#include <vm/pmap.h> 64#include <vm/vm_map.h> 65 66#include <sys/link_elf.h> 67 68#ifdef DDB_CTF 69#include <net/zlib.h> 70#endif 71 72#include "linker_if.h" 73 74#define MAXSEGS 4 75 76typedef 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#include <kern/kern_ctf.c> 127 128static int link_elf_link_common_finish(linker_file_t); 129static int link_elf_link_preload(linker_class_t cls, 130 const char *, linker_file_t *); 131static int link_elf_link_preload_finish(linker_file_t); 132static int link_elf_load_file(linker_class_t, const char *, 133 linker_file_t *); 134static int link_elf_lookup_symbol(linker_file_t, const char *, 135 c_linker_sym_t *); 136static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 137 linker_symval_t *); 138static int link_elf_search_symbol(linker_file_t, caddr_t, 139 c_linker_sym_t *, long *); 140 141static void link_elf_unload_file(linker_file_t); 142static void link_elf_unload_preload(linker_file_t); 143static int link_elf_lookup_set(linker_file_t, const char *, 144 void ***, void ***, int *); 145static int link_elf_each_function_name(linker_file_t, 146 int (*)(const char *, void *), void *); 147static int link_elf_each_function_nameval(linker_file_t, 148 linker_function_nameval_callback_t, void *); 149static void link_elf_reloc_local(linker_file_t); 150static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 151static long link_elf_strtab_get(linker_file_t, caddr_t *); 152static Elf_Addr elf_lookup(linker_file_t, Elf_Size, int); 153 154static kobj_method_t link_elf_methods[] = { 155 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 156 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 157 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 158 KOBJMETHOD(linker_unload, link_elf_unload_file), 159 KOBJMETHOD(linker_load_file, link_elf_load_file), 160 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 161 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 162 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 163 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 164 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 165 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 166 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 167 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 168 { 0, 0 } 169}; 170 171static struct linker_class link_elf_class = { 172#if ELF_TARG_CLASS == ELFCLASS32 173 "elf32", 174#else 175 "elf64", 176#endif 177 link_elf_methods, sizeof(struct elf_file) 178}; 179 180static int parse_dynamic(elf_file_t); 181static int relocate_file(elf_file_t); 182static int link_elf_preload_parse_symbols(elf_file_t); 183 184#ifdef GDB 185static void r_debug_state(struct r_debug *, struct link_map *); 186 187/* 188 * A list of loaded modules for GDB to use for loading symbols. 189 */ 190struct r_debug r_debug; 191 192#define GDB_STATE(s) do { \ 193 r_debug.r_state = s; r_debug_state(NULL, NULL); \ 194} while (0) 195 196/* 197 * Function for the debugger to set a breakpoint on to gain control. 198 */ 199static void 200r_debug_state(struct r_debug *dummy_one __unused, 201 struct link_map *dummy_two __unused) 202{ 203} 204 205static void 206link_elf_add_gdb(struct link_map *l) 207{ 208 struct link_map *prev; 209 210 l->l_next = NULL; 211 212 if (r_debug.r_map == NULL) { 213 /* Add first. */ 214 l->l_prev = NULL; 215 r_debug.r_map = l; 216 } else { 217 /* Append to list. */ 218 for (prev = r_debug.r_map; 219 prev->l_next != NULL; 220 prev = prev->l_next) 221 ; 222 l->l_prev = prev; 223 prev->l_next = l; 224 } 225} 226 227static void 228link_elf_delete_gdb(struct link_map *l) 229{ 230 if (l->l_prev == NULL) { 231 /* Remove first. */ 232 if ((r_debug.r_map = l->l_next) != NULL) 233 l->l_next->l_prev = NULL; 234 } else { 235 /* Remove any but first. */ 236 if ((l->l_prev->l_next = l->l_next) != NULL) 237 l->l_next->l_prev = l->l_prev; 238 } 239} 240#endif /* GDB */ 241 242#ifdef __ia64__ 243Elf_Addr link_elf_get_gp(linker_file_t); 244#endif 245 246/* 247 * The kernel symbol table starts here. 248 */ 249extern struct _dynamic _DYNAMIC; 250 251static void 252link_elf_error(const char *filename, const char *s) 253{ 254 if (filename == NULL) 255 printf("kldload: %s\n", s); 256 else 257 printf("kldload: %s: %s\n", filename, s); 258} 259 260/* 261 * Actions performed after linking/loading both the preloaded kernel and any 262 * modules; whether preloaded or dynamicly loaded. 263 */ 264static int 265link_elf_link_common_finish(linker_file_t lf) 266{ 267#ifdef GDB 268 elf_file_t ef = (elf_file_t)lf; 269 char *newfilename; 270#endif 271 int error; 272 273 /* Notify MD code that a module is being loaded. */ 274 error = elf_cpu_load_file(lf); 275 if (error != 0) 276 return (error); 277 278#ifdef GDB 279 GDB_STATE(RT_ADD); 280 ef->gdb.l_addr = lf->address; 281 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 282 strcpy(newfilename, lf->filename); 283 ef->gdb.l_name = newfilename; 284 ef->gdb.l_ld = ef->dynamic; 285 link_elf_add_gdb(&ef->gdb); 286 GDB_STATE(RT_CONSISTENT); 287#endif 288 289 return (0); 290} 291 292static void 293link_elf_init(void* arg) 294{ 295 Elf_Dyn *dp; 296 caddr_t modptr, baseptr, sizeptr; 297 elf_file_t ef; 298 char *modname; 299 300 linker_add_class(&link_elf_class); 301 302 dp = (Elf_Dyn *)&_DYNAMIC; 303 modname = NULL; 304 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 305 if (modptr == NULL) 306 modptr = preload_search_by_type("elf kernel"); 307 if (modptr != NULL) 308 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 309 if (modname == NULL) 310 modname = "kernel"; 311 linker_kernel_file = linker_make_file(modname, &link_elf_class); 312 if (linker_kernel_file == NULL) 313 panic("%s: Can't create linker structures for kernel", 314 __func__); 315 316 ef = (elf_file_t) linker_kernel_file; 317 ef->preloaded = 1; 318 ef->address = 0; 319#ifdef SPARSE_MAPPING 320 ef->object = 0; 321#endif 322 ef->dynamic = dp; 323 324 if (dp != NULL) 325 parse_dynamic(ef); 326 linker_kernel_file->address = (caddr_t) KERNBASE; 327 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 328 329 if (modptr != NULL) { 330 ef->modptr = modptr; 331 baseptr = preload_search_info(modptr, MODINFO_ADDR); 332 if (baseptr != NULL) 333 linker_kernel_file->address = *(caddr_t *)baseptr; 334 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 335 if (sizeptr != NULL) 336 linker_kernel_file->size = *(size_t *)sizeptr; 337 } 338 (void)link_elf_preload_parse_symbols(ef); 339 340#ifdef GDB 341 r_debug.r_map = NULL; 342 r_debug.r_brk = r_debug_state; 343 r_debug.r_state = RT_CONSISTENT; 344#endif 345 346 (void)link_elf_link_common_finish(linker_kernel_file); 347 linker_kernel_file->flags |= LINKER_FILE_LINKED; 348} 349 350SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0); 351 352static int 353link_elf_preload_parse_symbols(elf_file_t ef) 354{ 355 caddr_t pointer; 356 caddr_t ssym, esym, base; 357 caddr_t strtab; 358 int strcnt; 359 Elf_Sym *symtab; 360 int symcnt; 361 362 if (ef->modptr == NULL) 363 return (0); 364 pointer = preload_search_info(ef->modptr, 365 MODINFO_METADATA | MODINFOMD_SSYM); 366 if (pointer == NULL) 367 return (0); 368 ssym = *(caddr_t *)pointer; 369 pointer = preload_search_info(ef->modptr, 370 MODINFO_METADATA | MODINFOMD_ESYM); 371 if (pointer == NULL) 372 return (0); 373 esym = *(caddr_t *)pointer; 374 375 base = ssym; 376 377 symcnt = *(long *)base; 378 base += sizeof(long); 379 symtab = (Elf_Sym *)base; 380 base += roundup(symcnt, sizeof(long)); 381 382 if (base > esym || base < ssym) { 383 printf("Symbols are corrupt!\n"); 384 return (EINVAL); 385 } 386 387 strcnt = *(long *)base; 388 base += sizeof(long); 389 strtab = base; 390 base += roundup(strcnt, sizeof(long)); 391 392 if (base > esym || base < ssym) { 393 printf("Symbols are corrupt!\n"); 394 return (EINVAL); 395 } 396 397 ef->ddbsymtab = symtab; 398 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 399 ef->ddbstrtab = strtab; 400 ef->ddbstrcnt = strcnt; 401 402 return (0); 403} 404 405static int 406parse_dynamic(elf_file_t ef) 407{ 408 Elf_Dyn *dp; 409 int plttype = DT_REL; 410 411 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 412 switch (dp->d_tag) { 413 case DT_HASH: 414 { 415 /* From src/libexec/rtld-elf/rtld.c */ 416 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 417 (ef->address + dp->d_un.d_ptr); 418 ef->nbuckets = hashtab[0]; 419 ef->nchains = hashtab[1]; 420 ef->buckets = hashtab + 2; 421 ef->chains = ef->buckets + ef->nbuckets; 422 break; 423 } 424 case DT_STRTAB: 425 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 426 break; 427 case DT_STRSZ: 428 ef->strsz = dp->d_un.d_val; 429 break; 430 case DT_SYMTAB: 431 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 432 break; 433 case DT_SYMENT: 434 if (dp->d_un.d_val != sizeof(Elf_Sym)) 435 return (ENOEXEC); 436 break; 437 case DT_PLTGOT: 438 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 439 break; 440 case DT_REL: 441 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 442 break; 443 case DT_RELSZ: 444 ef->relsize = dp->d_un.d_val; 445 break; 446 case DT_RELENT: 447 if (dp->d_un.d_val != sizeof(Elf_Rel)) 448 return (ENOEXEC); 449 break; 450 case DT_JMPREL: 451 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 452 break; 453 case DT_PLTRELSZ: 454 ef->pltrelsize = dp->d_un.d_val; 455 break; 456 case DT_RELA: 457 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 458 break; 459 case DT_RELASZ: 460 ef->relasize = dp->d_un.d_val; 461 break; 462 case DT_RELAENT: 463 if (dp->d_un.d_val != sizeof(Elf_Rela)) 464 return (ENOEXEC); 465 break; 466 case DT_PLTREL: 467 plttype = dp->d_un.d_val; 468 if (plttype != DT_REL && plttype != DT_RELA) 469 return (ENOEXEC); 470 break; 471#ifdef GDB 472 case DT_DEBUG: 473 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 474 break; 475#endif 476 } 477 } 478 479 if (plttype == DT_RELA) { 480 ef->pltrela = (const Elf_Rela *)ef->pltrel; 481 ef->pltrel = NULL; 482 ef->pltrelasize = ef->pltrelsize; 483 ef->pltrelsize = 0; 484 } 485 486 ef->ddbsymtab = ef->symtab; 487 ef->ddbsymcnt = ef->nchains; 488 ef->ddbstrtab = ef->strtab; 489 ef->ddbstrcnt = ef->strsz; 490 491 return (0); 492} 493 494static int 495parse_dpcpu(elf_file_t ef) 496{ 497 int count; 498 int error; 499 500 ef->pcpu_start = 0; 501 ef->pcpu_stop = 0; 502 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 503 (void ***)&ef->pcpu_stop, &count); 504 /* Error just means there is no pcpu set to relocate. */ 505 if (error != 0) 506 return (0); 507 count *= sizeof(void *); 508 /* 509 * Allocate space in the primary pcpu area. Copy in our 510 * initialization from the data section and then initialize 511 * all per-cpu storage from that. 512 */ 513 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count); 514 if (ef->pcpu_base == 0) 515 return (ENOSPC); 516 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count); 517 dpcpu_copy((void *)ef->pcpu_base, count); 518 519 return (0); 520} 521 522#ifdef VIMAGE 523static int 524parse_vnet(elf_file_t ef) 525{ 526 int count; 527 int error; 528 529 ef->vnet_start = 0; 530 ef->vnet_stop = 0; 531 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 532 (void ***)&ef->vnet_stop, &count); 533 /* Error just means there is no vnet data set to relocate. */ 534 if (error != 0) 535 return (0); 536 count *= sizeof(void *); 537 /* 538 * Allocate space in the primary vnet area. Copy in our 539 * initialization from the data section and then initialize 540 * all per-vnet storage from that. 541 */ 542 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count); 543 if (ef->vnet_base == 0) 544 return (ENOSPC); 545 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count); 546 vnet_data_copy((void *)ef->vnet_base, count); 547 548 return (0); 549} 550#endif 551 552static int 553link_elf_link_preload(linker_class_t cls, 554 const char* filename, linker_file_t *result) 555{ 556 caddr_t modptr, baseptr, sizeptr, dynptr; 557 char *type; 558 elf_file_t ef; 559 linker_file_t lf; 560 int error; 561 vm_offset_t dp; 562 563 /* Look to see if we have the file preloaded */ 564 modptr = preload_search_by_name(filename); 565 if (modptr == NULL) 566 return (ENOENT); 567 568 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 569 baseptr = preload_search_info(modptr, MODINFO_ADDR); 570 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 571 dynptr = preload_search_info(modptr, 572 MODINFO_METADATA | MODINFOMD_DYNAMIC); 573 if (type == NULL || 574 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 575 strcmp(type, "elf module") != 0)) 576 return (EFTYPE); 577 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 578 return (EINVAL); 579 580 lf = linker_make_file(filename, &link_elf_class); 581 if (lf == NULL) 582 return (ENOMEM); 583 584 ef = (elf_file_t) lf; 585 ef->preloaded = 1; 586 ef->modptr = modptr; 587 ef->address = *(caddr_t *)baseptr; 588#ifdef SPARSE_MAPPING 589 ef->object = 0; 590#endif 591 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 592 ef->dynamic = (Elf_Dyn *)dp; 593 lf->address = ef->address; 594 lf->size = *(size_t *)sizeptr; 595 596 error = parse_dynamic(ef); 597 if (error == 0) 598 error = parse_dpcpu(ef); 599#ifdef VIMAGE 600 if (error == 0) 601 error = parse_vnet(ef); 602#endif 603 if (error != 0) { 604 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 605 return (error); 606 } 607 link_elf_reloc_local(lf); 608 *result = lf; 609 return (0); 610} 611 612static int 613link_elf_link_preload_finish(linker_file_t lf) 614{ 615 elf_file_t ef; 616 int error; 617 618 ef = (elf_file_t) lf; 619#if 0 /* this will be more trouble than it's worth for now */ 620 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 621 if (dp->d_tag != DT_NEEDED) 622 continue; 623 modname = ef->strtab + dp->d_un.d_val; 624 error = linker_load_module(modname, lf); 625 if (error != 0) 626 goto out; 627 } 628#endif 629 error = relocate_file(ef); 630 if (error != 0) 631 return (error); 632 (void)link_elf_preload_parse_symbols(ef); 633 634 return (link_elf_link_common_finish(lf)); 635} 636 637static int 638link_elf_load_file(linker_class_t cls, const char* filename, 639 linker_file_t* result) 640{ 641 struct nameidata nd; 642 struct thread* td = curthread; /* XXX */ 643 Elf_Ehdr *hdr; 644 caddr_t firstpage; 645 int nbytes, i; 646 Elf_Phdr *phdr; 647 Elf_Phdr *phlimit; 648 Elf_Phdr *segs[MAXSEGS]; 649 int nsegs; 650 Elf_Phdr *phdyn; 651 Elf_Phdr *phphdr; 652 caddr_t mapbase; 653 size_t mapsize; 654 Elf_Off base_offset; 655 Elf_Addr base_vaddr; 656 Elf_Addr base_vlimit; 657 int error = 0; 658 int resid, flags; 659 elf_file_t ef; 660 linker_file_t lf; 661 Elf_Shdr *shdr; 662 int symtabindex; 663 int symstrindex; 664 int symcnt; 665 int strcnt; 666 int vfslocked; 667 668 shdr = NULL; 669 lf = NULL; 670 671 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td); 672 flags = FREAD; 673 error = vn_open(&nd, &flags, 0, NULL); 674 if (error != 0) 675 return (error); 676 vfslocked = NDHASGIANT(&nd); 677 NDFREE(&nd, NDF_ONLY_PNBUF); 678 if (nd.ni_vp->v_type != VREG) { 679 error = ENOEXEC; 680 firstpage = NULL; 681 goto out; 682 } 683#ifdef MAC 684 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 685 if (error != 0) { 686 firstpage = NULL; 687 goto out; 688 } 689#endif 690 691 /* 692 * Read the elf header from the file. 693 */ 694 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 695 if (firstpage == NULL) { 696 error = ENOMEM; 697 goto out; 698 } 699 hdr = (Elf_Ehdr *)firstpage; 700 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 701 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 702 &resid, td); 703 nbytes = PAGE_SIZE - resid; 704 if (error != 0) 705 goto out; 706 707 if (!IS_ELF(*hdr)) { 708 error = ENOEXEC; 709 goto out; 710 } 711 712 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 713 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 714 link_elf_error(filename, "Unsupported file layout"); 715 error = ENOEXEC; 716 goto out; 717 } 718 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 719 hdr->e_version != EV_CURRENT) { 720 link_elf_error(filename, "Unsupported file version"); 721 error = ENOEXEC; 722 goto out; 723 } 724 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 725 error = ENOSYS; 726 goto out; 727 } 728 if (hdr->e_machine != ELF_TARG_MACH) { 729 link_elf_error(filename, "Unsupported machine"); 730 error = ENOEXEC; 731 goto out; 732 } 733 734 /* 735 * We rely on the program header being in the first page. 736 * This is not strictly required by the ABI specification, but 737 * it seems to always true in practice. And, it simplifies 738 * things considerably. 739 */ 740 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 741 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 742 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 743 link_elf_error(filename, "Unreadable program headers"); 744 745 /* 746 * Scan the program header entries, and save key information. 747 * 748 * We rely on there being exactly two load segments, text and data, 749 * in that order. 750 */ 751 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 752 phlimit = phdr + hdr->e_phnum; 753 nsegs = 0; 754 phdyn = NULL; 755 phphdr = NULL; 756 while (phdr < phlimit) { 757 switch (phdr->p_type) { 758 case PT_LOAD: 759 if (nsegs == MAXSEGS) { 760 link_elf_error(filename, "Too many sections"); 761 error = ENOEXEC; 762 goto out; 763 } 764 /* 765 * XXX: We just trust they come in right order ?? 766 */ 767 segs[nsegs] = phdr; 768 ++nsegs; 769 break; 770 771 case PT_PHDR: 772 phphdr = phdr; 773 break; 774 775 case PT_DYNAMIC: 776 phdyn = phdr; 777 break; 778 779 case PT_INTERP: 780 error = ENOSYS; 781 goto out; 782 } 783 784 ++phdr; 785 } 786 if (phdyn == NULL) { 787 link_elf_error(filename, "Object is not dynamically-linked"); 788 error = ENOEXEC; 789 goto out; 790 } 791 if (nsegs == 0) { 792 link_elf_error(filename, "No sections"); 793 error = ENOEXEC; 794 goto out; 795 } 796 797 /* 798 * Allocate the entire address space of the object, to stake 799 * out our contiguous region, and to establish the base 800 * address for relocation. 801 */ 802 base_offset = trunc_page(segs[0]->p_offset); 803 base_vaddr = trunc_page(segs[0]->p_vaddr); 804 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 805 segs[nsegs - 1]->p_memsz); 806 mapsize = base_vlimit - base_vaddr; 807 808 lf = linker_make_file(filename, &link_elf_class); 809 if (lf == NULL) { 810 error = ENOMEM; 811 goto out; 812 } 813 814 ef = (elf_file_t) lf; 815#ifdef SPARSE_MAPPING 816 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 817 if (ef->object == NULL) { 818 error = ENOMEM; 819 goto out; 820 } 821 ef->address = (caddr_t) vm_map_min(kernel_map); 822 error = vm_map_find(kernel_map, ef->object, 0, 823 (vm_offset_t *) &ef->address, mapsize, 1, 824 VM_PROT_ALL, VM_PROT_ALL, 0); 825 if (error != 0) { 826 vm_object_deallocate(ef->object); 827 ef->object = 0; 828 goto out; 829 } 830#else 831 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 832 if (ef->address == NULL) { 833 error = ENOMEM; 834 goto out; 835 } 836#endif 837 mapbase = ef->address; 838 839 /* 840 * Read the text and data sections and zero the bss. 841 */ 842 for (i = 0; i < nsegs; i++) { 843 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 844 error = vn_rdwr(UIO_READ, nd.ni_vp, 845 segbase, segs[i]->p_filesz, segs[i]->p_offset, 846 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 847 &resid, td); 848 if (error != 0) 849 goto out; 850 bzero(segbase + segs[i]->p_filesz, 851 segs[i]->p_memsz - segs[i]->p_filesz); 852 853#ifdef SPARSE_MAPPING 854 /* 855 * Wire down the pages 856 */ 857 error = vm_map_wire(kernel_map, 858 (vm_offset_t) segbase, 859 (vm_offset_t) segbase + segs[i]->p_memsz, 860 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 861 if (error != KERN_SUCCESS) { 862 error = ENOMEM; 863 goto out; 864 } 865#endif 866 } 867 868#ifdef GPROF 869 /* Update profiling information with the new text segment. */ 870 mtx_lock(&Giant); 871 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 872 segs[0]->p_memsz)); 873 mtx_unlock(&Giant); 874#endif 875 876 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 877 878 lf->address = ef->address; 879 lf->size = mapsize; 880 881 error = parse_dynamic(ef); 882 if (error != 0) 883 goto out; 884 error = parse_dpcpu(ef); 885 if (error != 0) 886 goto out; 887#ifdef VIMAGE 888 error = parse_vnet(ef); 889 if (error != 0) 890 goto out; 891#endif 892 link_elf_reloc_local(lf); 893 894 VOP_UNLOCK(nd.ni_vp, 0); 895 error = linker_load_dependencies(lf); 896 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 897 if (error != 0) 898 goto out; 899#if 0 /* this will be more trouble than it's worth for now */ 900 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 901 if (dp->d_tag != DT_NEEDED) 902 continue; 903 modname = ef->strtab + dp->d_un.d_val; 904 error = linker_load_module(modname, lf); 905 if (error != 0) 906 goto out; 907 } 908#endif 909 error = relocate_file(ef); 910 if (error != 0) 911 goto out; 912 913 /* 914 * Try and load the symbol table if it's present. (you can 915 * strip it!) 916 */ 917 nbytes = hdr->e_shnum * hdr->e_shentsize; 918 if (nbytes == 0 || hdr->e_shoff == 0) 919 goto nosyms; 920 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 921 if (shdr == NULL) { 922 error = ENOMEM; 923 goto out; 924 } 925 error = vn_rdwr(UIO_READ, nd.ni_vp, 926 (caddr_t)shdr, nbytes, hdr->e_shoff, 927 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 928 &resid, td); 929 if (error != 0) 930 goto out; 931 symtabindex = -1; 932 symstrindex = -1; 933 for (i = 0; i < hdr->e_shnum; i++) { 934 if (shdr[i].sh_type == SHT_SYMTAB) { 935 symtabindex = i; 936 symstrindex = shdr[i].sh_link; 937 } 938 } 939 if (symtabindex < 0 || symstrindex < 0) 940 goto nosyms; 941 942 symcnt = shdr[symtabindex].sh_size; 943 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 944 strcnt = shdr[symstrindex].sh_size; 945 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 946 947 if (ef->symbase == NULL || ef->strbase == NULL) { 948 error = ENOMEM; 949 goto out; 950 } 951 error = vn_rdwr(UIO_READ, nd.ni_vp, 952 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 953 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 954 &resid, td); 955 if (error != 0) 956 goto out; 957 error = vn_rdwr(UIO_READ, nd.ni_vp, 958 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 959 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 960 &resid, td); 961 if (error != 0) 962 goto out; 963 964 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 965 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 966 ef->ddbstrcnt = strcnt; 967 ef->ddbstrtab = ef->strbase; 968 969 error = link_elf_link_common_finish(lf); 970 if (error != 0) 971 goto out; 972 973nosyms: 974 *result = lf; 975 976out: 977 VOP_UNLOCK(nd.ni_vp, 0); 978 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 979 VFS_UNLOCK_GIANT(vfslocked); 980 if (error != 0 && lf != NULL) 981 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 982 if (shdr != NULL) 983 free(shdr, M_LINKER); 984 if (firstpage != NULL) 985 free(firstpage, M_LINKER); 986 987 return (error); 988} 989 990Elf_Addr 991elf_relocaddr(linker_file_t lf, Elf_Addr x) 992{ 993 elf_file_t ef; 994 995 ef = (elf_file_t)lf; 996 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 997 return ((x - ef->pcpu_start) + ef->pcpu_base); 998#ifdef VIMAGE 999 if (x >= ef->vnet_start && x < ef->vnet_stop) 1000 return ((x - ef->vnet_start) + ef->vnet_base); 1001#endif 1002 return (x); 1003} 1004 1005 1006static void 1007link_elf_unload_file(linker_file_t file) 1008{ 1009 elf_file_t ef = (elf_file_t) file; 1010 1011 if (ef->pcpu_base != 0) { 1012 dpcpu_free((void *)ef->pcpu_base, 1013 ef->pcpu_stop - ef->pcpu_start); 1014 } 1015#ifdef VIMAGE 1016 if (ef->vnet_base != 0) { 1017 vnet_data_free((void *)ef->vnet_base, 1018 ef->vnet_stop - ef->vnet_start); 1019 } 1020#endif 1021#ifdef GDB 1022 if (ef->gdb.l_ld != NULL) { 1023 GDB_STATE(RT_DELETE); 1024 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1025 link_elf_delete_gdb(&ef->gdb); 1026 GDB_STATE(RT_CONSISTENT); 1027 } 1028#endif 1029 1030 /* Notify MD code that a module is being unloaded. */ 1031 elf_cpu_unload_file(file); 1032 1033 if (ef->preloaded) { 1034 link_elf_unload_preload(file); 1035 return; 1036 } 1037 1038#ifdef SPARSE_MAPPING 1039 if (ef->object != NULL) { 1040 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1041 (vm_offset_t) ef->address 1042 + (ef->object->size << PAGE_SHIFT)); 1043 } 1044#else 1045 if (ef->address != NULL) 1046 free(ef->address, M_LINKER); 1047#endif 1048 if (ef->symbase != NULL) 1049 free(ef->symbase, M_LINKER); 1050 if (ef->strbase != NULL) 1051 free(ef->strbase, M_LINKER); 1052 if (ef->ctftab != NULL) 1053 free(ef->ctftab, M_LINKER); 1054 if (ef->ctfoff != NULL) 1055 free(ef->ctfoff, M_LINKER); 1056 if (ef->typoff != NULL) 1057 free(ef->typoff, M_LINKER); 1058} 1059 1060static void 1061link_elf_unload_preload(linker_file_t file) 1062{ 1063 if (file->filename != NULL) 1064 preload_delete_name(file->filename); 1065} 1066 1067static const char * 1068symbol_name(elf_file_t ef, Elf_Size r_info) 1069{ 1070 const Elf_Sym *ref; 1071 1072 if (ELF_R_SYM(r_info)) { 1073 ref = ef->symtab + ELF_R_SYM(r_info); 1074 return (ef->strtab + ref->st_name); 1075 } 1076 return (NULL); 1077} 1078 1079static int 1080relocate_file(elf_file_t ef) 1081{ 1082 const Elf_Rel *rellim; 1083 const Elf_Rel *rel; 1084 const Elf_Rela *relalim; 1085 const Elf_Rela *rela; 1086 const char *symname; 1087 1088 /* Perform relocations without addend if there are any: */ 1089 rel = ef->rel; 1090 if (rel != NULL) { 1091 rellim = (const Elf_Rel *) 1092 ((const char *)ef->rel + ef->relsize); 1093 while (rel < rellim) { 1094 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1095 ELF_RELOC_REL, elf_lookup)) { 1096 symname = symbol_name(ef, rel->r_info); 1097 printf("link_elf: symbol %s undefined\n", symname); 1098 return (ENOENT); 1099 } 1100 rel++; 1101 } 1102 } 1103 1104 /* Perform relocations with addend if there are any: */ 1105 rela = ef->rela; 1106 if (rela != NULL) { 1107 relalim = (const Elf_Rela *) 1108 ((const char *)ef->rela + ef->relasize); 1109 while (rela < relalim) { 1110 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1111 ELF_RELOC_RELA, elf_lookup)) { 1112 symname = symbol_name(ef, rela->r_info); 1113 printf("link_elf: symbol %s undefined\n", 1114 symname); 1115 return (ENOENT); 1116 } 1117 rela++; 1118 } 1119 } 1120 1121 /* Perform PLT relocations without addend if there are any: */ 1122 rel = ef->pltrel; 1123 if (rel != NULL) { 1124 rellim = (const Elf_Rel *) 1125 ((const char *)ef->pltrel + ef->pltrelsize); 1126 while (rel < rellim) { 1127 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1128 ELF_RELOC_REL, elf_lookup)) { 1129 symname = symbol_name(ef, rel->r_info); 1130 printf("link_elf: symbol %s undefined\n", 1131 symname); 1132 return (ENOENT); 1133 } 1134 rel++; 1135 } 1136 } 1137 1138 /* Perform relocations with addend if there are any: */ 1139 rela = ef->pltrela; 1140 if (rela != NULL) { 1141 relalim = (const Elf_Rela *) 1142 ((const char *)ef->pltrela + ef->pltrelasize); 1143 while (rela < relalim) { 1144 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1145 ELF_RELOC_RELA, elf_lookup)) { 1146 symname = symbol_name(ef, rela->r_info); 1147 printf("link_elf: symbol %s undefined\n", 1148 symname); 1149 return (ENOENT); 1150 } 1151 rela++; 1152 } 1153 } 1154 1155 return (0); 1156} 1157 1158/* 1159 * Hash function for symbol table lookup. Don't even think about changing 1160 * this. It is specified by the System V ABI. 1161 */ 1162static unsigned long 1163elf_hash(const char *name) 1164{ 1165 const unsigned char *p = (const unsigned char *) name; 1166 unsigned long h = 0; 1167 unsigned long g; 1168 1169 while (*p != '\0') { 1170 h = (h << 4) + *p++; 1171 if ((g = h & 0xf0000000) != 0) 1172 h ^= g >> 24; 1173 h &= ~g; 1174 } 1175 return (h); 1176} 1177 1178static int 1179link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1180{ 1181 elf_file_t ef = (elf_file_t) lf; 1182 unsigned long symnum; 1183 const Elf_Sym* symp; 1184 const char *strp; 1185 unsigned long hash; 1186 int i; 1187 1188 /* If we don't have a hash, bail. */ 1189 if (ef->buckets == NULL || ef->nbuckets == 0) { 1190 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1191 return (ENOENT); 1192 } 1193 1194 /* First, search hashed global symbols */ 1195 hash = elf_hash(name); 1196 symnum = ef->buckets[hash % ef->nbuckets]; 1197 1198 while (symnum != STN_UNDEF) { 1199 if (symnum >= ef->nchains) { 1200 printf("%s: corrupt symbol table\n", __func__); 1201 return (ENOENT); 1202 } 1203 1204 symp = ef->symtab + symnum; 1205 if (symp->st_name == 0) { 1206 printf("%s: corrupt symbol table\n", __func__); 1207 return (ENOENT); 1208 } 1209 1210 strp = ef->strtab + symp->st_name; 1211 1212 if (strcmp(name, strp) == 0) { 1213 if (symp->st_shndx != SHN_UNDEF || 1214 (symp->st_value != 0 && 1215 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1216 *sym = (c_linker_sym_t) symp; 1217 return (0); 1218 } 1219 return (ENOENT); 1220 } 1221 1222 symnum = ef->chains[symnum]; 1223 } 1224 1225 /* If we have not found it, look at the full table (if loaded) */ 1226 if (ef->symtab == ef->ddbsymtab) 1227 return (ENOENT); 1228 1229 /* Exhaustive search */ 1230 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1231 strp = ef->ddbstrtab + symp->st_name; 1232 if (strcmp(name, strp) == 0) { 1233 if (symp->st_shndx != SHN_UNDEF || 1234 (symp->st_value != 0 && 1235 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1236 *sym = (c_linker_sym_t) symp; 1237 return (0); 1238 } 1239 return (ENOENT); 1240 } 1241 } 1242 1243 return (ENOENT); 1244} 1245 1246static int 1247link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1248 linker_symval_t *symval) 1249{ 1250 elf_file_t ef = (elf_file_t) lf; 1251 const Elf_Sym* es = (const Elf_Sym*) sym; 1252 1253 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1254 symval->name = ef->strtab + es->st_name; 1255 symval->value = (caddr_t) ef->address + es->st_value; 1256 symval->size = es->st_size; 1257 return (0); 1258 } 1259 if (ef->symtab == ef->ddbsymtab) 1260 return (ENOENT); 1261 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1262 symval->name = ef->ddbstrtab + es->st_name; 1263 symval->value = (caddr_t) ef->address + es->st_value; 1264 symval->size = es->st_size; 1265 return (0); 1266 } 1267 return (ENOENT); 1268} 1269 1270static int 1271link_elf_search_symbol(linker_file_t lf, caddr_t value, 1272 c_linker_sym_t *sym, long *diffp) 1273{ 1274 elf_file_t ef = (elf_file_t) lf; 1275 u_long off = (uintptr_t) (void *) value; 1276 u_long diff = off; 1277 u_long st_value; 1278 const Elf_Sym* es; 1279 const Elf_Sym* best = 0; 1280 int i; 1281 1282 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1283 if (es->st_name == 0) 1284 continue; 1285 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1286 if (off >= st_value) { 1287 if (off - st_value < diff) { 1288 diff = off - st_value; 1289 best = es; 1290 if (diff == 0) 1291 break; 1292 } else if (off - st_value == diff) { 1293 best = es; 1294 } 1295 } 1296 } 1297 if (best == 0) 1298 *diffp = off; 1299 else 1300 *diffp = diff; 1301 *sym = (c_linker_sym_t) best; 1302 1303 return (0); 1304} 1305 1306/* 1307 * Look up a linker set on an ELF system. 1308 */ 1309static int 1310link_elf_lookup_set(linker_file_t lf, const char *name, 1311 void ***startp, void ***stopp, int *countp) 1312{ 1313 c_linker_sym_t sym; 1314 linker_symval_t symval; 1315 char *setsym; 1316 void **start, **stop; 1317 int len, error = 0, count; 1318 1319 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1320 setsym = malloc(len, M_LINKER, M_WAITOK); 1321 if (setsym == NULL) 1322 return (ENOMEM); 1323 1324 /* get address of first entry */ 1325 snprintf(setsym, len, "%s%s", "__start_set_", name); 1326 error = link_elf_lookup_symbol(lf, setsym, &sym); 1327 if (error != 0) 1328 goto out; 1329 link_elf_symbol_values(lf, sym, &symval); 1330 if (symval.value == 0) { 1331 error = ESRCH; 1332 goto out; 1333 } 1334 start = (void **)symval.value; 1335 1336 /* get address of last entry */ 1337 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1338 error = link_elf_lookup_symbol(lf, setsym, &sym); 1339 if (error != 0) 1340 goto out; 1341 link_elf_symbol_values(lf, sym, &symval); 1342 if (symval.value == 0) { 1343 error = ESRCH; 1344 goto out; 1345 } 1346 stop = (void **)symval.value; 1347 1348 /* and the number of entries */ 1349 count = stop - start; 1350 1351 /* and copy out */ 1352 if (startp != NULL) 1353 *startp = start; 1354 if (stopp != NULL) 1355 *stopp = stop; 1356 if (countp != NULL) 1357 *countp = count; 1358 1359out: 1360 free(setsym, M_LINKER); 1361 return (error); 1362} 1363 1364static int 1365link_elf_each_function_name(linker_file_t file, 1366 int (*callback)(const char *, void *), void *opaque) 1367{ 1368 elf_file_t ef = (elf_file_t)file; 1369 const Elf_Sym *symp; 1370 int i, error; 1371 1372 /* Exhaustive search */ 1373 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1374 if (symp->st_value != 0 && 1375 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1376 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1377 if (error != 0) 1378 return (error); 1379 } 1380 } 1381 return (0); 1382} 1383 1384static int 1385link_elf_each_function_nameval(linker_file_t file, 1386 linker_function_nameval_callback_t callback, void *opaque) 1387{ 1388 linker_symval_t symval; 1389 elf_file_t ef = (elf_file_t)file; 1390 const Elf_Sym* symp; 1391 int i, error; 1392 1393 /* Exhaustive search */ 1394 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1395 if (symp->st_value != 0 && 1396 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1397 error = link_elf_symbol_values(file, 1398 (c_linker_sym_t) symp, &symval); 1399 if (error != 0) 1400 return (error); 1401 error = callback(file, i, &symval, opaque); 1402 if (error != 0) 1403 return (error); 1404 } 1405 } 1406 return (0); 1407} 1408 1409#ifdef __ia64__ 1410/* 1411 * Each KLD has its own GP. The GP value for each load module is given by 1412 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but 1413 * don't have direct access to the ELF file structure. The link_elf_get_gp() 1414 * function returns the GP given a pointer to a generic linker file struct. 1415 */ 1416Elf_Addr 1417link_elf_get_gp(linker_file_t lf) 1418{ 1419 elf_file_t ef = (elf_file_t)lf; 1420 return ((Elf_Addr)ef->got); 1421} 1422#endif 1423 1424const Elf_Sym * 1425elf_get_sym(linker_file_t lf, Elf_Size symidx) 1426{ 1427 elf_file_t ef = (elf_file_t)lf; 1428 1429 if (symidx >= ef->nchains) 1430 return (NULL); 1431 return (ef->symtab + symidx); 1432} 1433 1434const char * 1435elf_get_symname(linker_file_t lf, Elf_Size symidx) 1436{ 1437 elf_file_t ef = (elf_file_t)lf; 1438 const Elf_Sym *sym; 1439 1440 if (symidx >= ef->nchains) 1441 return (NULL); 1442 sym = ef->symtab + symidx; 1443 return (ef->strtab + sym->st_name); 1444} 1445 1446/* 1447 * Symbol lookup function that can be used when the symbol index is known (ie 1448 * in relocations). It uses the symbol index instead of doing a fully fledged 1449 * hash table based lookup when such is valid. For example for local symbols. 1450 * This is not only more efficient, it's also more correct. It's not always 1451 * the case that the symbol can be found through the hash table. 1452 */ 1453static Elf_Addr 1454elf_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1455{ 1456 elf_file_t ef = (elf_file_t)lf; 1457 const Elf_Sym *sym; 1458 const char *symbol; 1459 1460 /* Don't even try to lookup the symbol if the index is bogus. */ 1461 if (symidx >= ef->nchains) 1462 return (0); 1463 1464 sym = ef->symtab + symidx; 1465 1466 /* 1467 * Don't do a full lookup when the symbol is local. It may even 1468 * fail because it may not be found through the hash table. 1469 */ 1470 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1471 /* Force lookup failure when we have an insanity. */ 1472 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) 1473 return (0); 1474 return ((Elf_Addr)ef->address + sym->st_value); 1475 } 1476 1477 /* 1478 * XXX we can avoid doing a hash table based lookup for global 1479 * symbols as well. This however is not always valid, so we'll 1480 * just do it the hard way for now. Performance tweaks can 1481 * always be added. 1482 */ 1483 1484 symbol = ef->strtab + sym->st_name; 1485 1486 /* Force a lookup failure if the symbol name is bogus. */ 1487 if (*symbol == 0) 1488 return (0); 1489 1490 return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1491} 1492 1493static void 1494link_elf_reloc_local(linker_file_t lf) 1495{ 1496 const Elf_Rel *rellim; 1497 const Elf_Rel *rel; 1498 const Elf_Rela *relalim; 1499 const Elf_Rela *rela; 1500 elf_file_t ef = (elf_file_t)lf; 1501 1502 /* Perform relocations without addend if there are any: */ 1503 if ((rel = ef->rel) != NULL) { 1504 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1505 while (rel < rellim) { 1506 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1507 ELF_RELOC_REL, elf_lookup); 1508 rel++; 1509 } 1510 } 1511 1512 /* Perform relocations with addend if there are any: */ 1513 if ((rela = ef->rela) != NULL) { 1514 relalim = (const Elf_Rela *) 1515 ((const char *)ef->rela + ef->relasize); 1516 while (rela < relalim) { 1517 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1518 ELF_RELOC_RELA, elf_lookup); 1519 rela++; 1520 } 1521 } 1522} 1523 1524static long 1525link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1526{ 1527 elf_file_t ef = (elf_file_t)lf; 1528 1529 *symtab = ef->ddbsymtab; 1530 1531 if (*symtab == NULL) 1532 return (0); 1533 1534 return (ef->ddbsymcnt); 1535} 1536 1537static long 1538link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1539{ 1540 elf_file_t ef = (elf_file_t)lf; 1541 1542 *strtab = ef->ddbstrtab; 1543 1544 if (*strtab == NULL) 1545 return (0); 1546 1547 return (ef->ddbstrcnt); 1548} 1549