1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1998-2000 Doug Rabson 5 * Copyright (c) 2004 Peter Wemm 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #include "opt_ddb.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/fcntl.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/linker.h> 40 #include <sys/mutex.h> 41 #include <sys/mount.h> 42 #include <sys/namei.h> 43 #include <sys/proc.h> 44 #include <sys/rwlock.h> 45 #include <sys/sysctl.h> 46 #include <sys/vnode.h> 47 48 #include <machine/elf.h> 49 50 #include <net/vnet.h> 51 52 #include <security/mac/mac_framework.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_param.h> 56 #include <vm/pmap.h> 57 #include <vm/vm_extern.h> 58 #include <vm/vm_kern.h> 59 #include <vm/vm_map.h> 60 #include <vm/vm_object.h> 61 #include <vm/vm_page.h> 62 #include <vm/vm_pager.h> 63 64 #include <sys/link_elf.h> 65 66 #ifdef DDB_CTF 67 #include <contrib/zlib/zlib.h> 68 #endif 69 70 #include "linker_if.h" 71 72 typedef struct { 73 void *addr; 74 Elf_Off size; 75 int flags; /* Section flags. */ 76 int sec; /* Original section number. */ 77 char *name; 78 } Elf_progent; 79 80 typedef struct { 81 Elf_Rel *rel; 82 int nrel; 83 int sec; 84 } Elf_relent; 85 86 typedef struct { 87 Elf_Rela *rela; 88 int nrela; 89 int sec; 90 } Elf_relaent; 91 92 typedef struct elf_file { 93 struct linker_file lf; /* Common fields */ 94 95 int preloaded; 96 caddr_t address; /* Relocation address */ 97 vm_object_t object; /* VM object to hold file pages */ 98 Elf_Shdr *e_shdr; 99 100 Elf_progent *progtab; 101 u_int nprogtab; 102 103 Elf_relaent *relatab; 104 u_int nrelatab; 105 106 Elf_relent *reltab; 107 int nreltab; 108 109 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 110 long ddbsymcnt; /* Number of symbols */ 111 caddr_t ddbstrtab; /* String table */ 112 long ddbstrcnt; /* number of bytes in string table */ 113 114 caddr_t shstrtab; /* Section name string table */ 115 long shstrcnt; /* number of bytes in string table */ 116 117 caddr_t ctftab; /* CTF table */ 118 long ctfcnt; /* number of bytes in CTF table */ 119 caddr_t ctfoff; /* CTF offset table */ 120 caddr_t typoff; /* Type offset table */ 121 long typlen; /* Number of type entries. */ 122 123 } *elf_file_t; 124 125 #include <kern/kern_ctf.c> 126 127 static int link_elf_link_preload(linker_class_t cls, 128 const char *, linker_file_t *); 129 static int link_elf_link_preload_finish(linker_file_t); 130 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); 131 static int link_elf_lookup_symbol(linker_file_t, const char *, 132 c_linker_sym_t *); 133 static int link_elf_lookup_debug_symbol(linker_file_t, const char *, 134 c_linker_sym_t *); 135 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 136 linker_symval_t *); 137 static int link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t, 138 linker_symval_t *); 139 static int link_elf_search_symbol(linker_file_t, caddr_t value, 140 c_linker_sym_t *sym, long *diffp); 141 142 static void link_elf_unload_file(linker_file_t); 143 static int link_elf_lookup_set(linker_file_t, const char *, 144 void ***, void ***, int *); 145 static int link_elf_each_function_name(linker_file_t, 146 int (*)(const char *, void *), void *); 147 static int link_elf_each_function_nameval(linker_file_t, 148 linker_function_nameval_callback_t, 149 void *); 150 static int link_elf_reloc_local(linker_file_t, bool); 151 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 152 static long link_elf_strtab_get(linker_file_t, caddr_t *); 153 154 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, 155 Elf_Addr *); 156 157 static kobj_method_t link_elf_methods[] = { 158 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 159 KOBJMETHOD(linker_lookup_debug_symbol, link_elf_lookup_debug_symbol), 160 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 161 KOBJMETHOD(linker_debug_symbol_values, link_elf_debug_symbol_values), 162 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 163 KOBJMETHOD(linker_unload, link_elf_unload_file), 164 KOBJMETHOD(linker_load_file, link_elf_load_file), 165 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 166 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 167 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 168 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 169 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 170 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 171 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 172 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 173 KOBJMETHOD_END 174 }; 175 176 static struct linker_class link_elf_class = { 177 #if ELF_TARG_CLASS == ELFCLASS32 178 "elf32_obj", 179 #else 180 "elf64_obj", 181 #endif 182 link_elf_methods, sizeof(struct elf_file) 183 }; 184 185 static bool link_elf_obj_leak_locals = true; 186 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_obj_leak_locals, 187 CTLFLAG_RWTUN, &link_elf_obj_leak_locals, 0, 188 "Allow local symbols to participate in global module symbol resolution"); 189 190 static int relocate_file(elf_file_t ef); 191 static void elf_obj_cleanup_globals_cache(elf_file_t); 192 193 static void 194 link_elf_error(const char *filename, const char *s) 195 { 196 if (filename == NULL) 197 printf("kldload: %s\n", s); 198 else 199 printf("kldload: %s: %s\n", filename, s); 200 } 201 202 static void 203 link_elf_init(void *arg) 204 { 205 206 linker_add_class(&link_elf_class); 207 } 208 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL); 209 210 static void 211 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end, 212 vm_prot_t prot) 213 { 214 int error __unused; 215 216 KASSERT(start <= end && start >= (vm_offset_t)ef->address && 217 end <= round_page((vm_offset_t)ef->address + ef->lf.size), 218 ("link_elf_protect_range: invalid range %#jx-%#jx", 219 (uintmax_t)start, (uintmax_t)end)); 220 221 if (start == end) 222 return; 223 if (ef->preloaded) { 224 #ifdef __amd64__ 225 error = pmap_change_prot(start, end - start, prot); 226 KASSERT(error == 0, 227 ("link_elf_protect_range: pmap_change_prot() returned %d", 228 error)); 229 #endif 230 return; 231 } 232 error = vm_map_protect(kernel_map, start, end, prot, 0, 233 VM_MAP_PROTECT_SET_PROT); 234 KASSERT(error == KERN_SUCCESS, 235 ("link_elf_protect_range: vm_map_protect() returned %d", error)); 236 } 237 238 /* 239 * Restrict permissions on linker file memory based on section flags. 240 * Sections need not be page-aligned, so overlap within a page is possible. 241 */ 242 static void 243 link_elf_protect(elf_file_t ef) 244 { 245 vm_offset_t end, segend, segstart, start; 246 vm_prot_t gapprot, prot, segprot; 247 int i; 248 249 /* 250 * If the file was preloaded, the last page may contain other preloaded 251 * data which may need to be writeable. ELF files are always 252 * page-aligned, but other preloaded data, such as entropy or CPU 253 * microcode may be loaded with a smaller alignment. 254 */ 255 gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ; 256 257 start = end = (vm_offset_t)ef->address; 258 prot = VM_PROT_READ; 259 for (i = 0; i < ef->nprogtab; i++) { 260 /* 261 * VNET and DPCPU sections have their memory allocated by their 262 * respective subsystems. 263 */ 264 if (ef->progtab[i].name != NULL && ( 265 #ifdef VIMAGE 266 strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 || 267 #endif 268 strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0)) 269 continue; 270 271 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr); 272 segend = round_page((vm_offset_t)ef->progtab[i].addr + 273 ef->progtab[i].size); 274 segprot = VM_PROT_READ; 275 if ((ef->progtab[i].flags & SHF_WRITE) != 0) 276 segprot |= VM_PROT_WRITE; 277 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0) 278 segprot |= VM_PROT_EXECUTE; 279 280 if (end <= segstart) { 281 /* 282 * Case 1: there is no overlap between the previous 283 * segment and this one. Apply protections to the 284 * previous segment, and protect the gap between the 285 * previous and current segments, if any. 286 */ 287 link_elf_protect_range(ef, start, end, prot); 288 link_elf_protect_range(ef, end, segstart, gapprot); 289 290 start = segstart; 291 end = segend; 292 prot = segprot; 293 } else if (start < segstart && end == segend) { 294 /* 295 * Case 2: the current segment is a subrange of the 296 * previous segment. Apply protections to the 297 * non-overlapping portion of the previous segment. 298 */ 299 link_elf_protect_range(ef, start, segstart, prot); 300 301 start = segstart; 302 prot |= segprot; 303 } else if (end < segend) { 304 /* 305 * Case 3: there is partial overlap between the previous 306 * and current segments. Apply protections to the 307 * non-overlapping portion of the previous segment, and 308 * then the overlap, which must use the union of the two 309 * segments' protections. 310 */ 311 link_elf_protect_range(ef, start, segstart, prot); 312 link_elf_protect_range(ef, segstart, end, 313 prot | segprot); 314 start = end; 315 end = segend; 316 prot = segprot; 317 } else { 318 /* 319 * Case 4: the two segments reside in the same page. 320 */ 321 prot |= segprot; 322 } 323 } 324 325 /* 326 * Fix up the last unprotected segment and trailing data. 327 */ 328 link_elf_protect_range(ef, start, end, prot); 329 link_elf_protect_range(ef, end, 330 round_page((vm_offset_t)ef->address + ef->lf.size), gapprot); 331 } 332 333 static int 334 link_elf_link_preload(linker_class_t cls, const char *filename, 335 linker_file_t *result) 336 { 337 Elf_Ehdr *hdr; 338 Elf_Shdr *shdr; 339 Elf_Sym *es; 340 void *modptr, *baseptr, *sizeptr; 341 char *type; 342 elf_file_t ef; 343 linker_file_t lf; 344 Elf_Addr off; 345 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 346 347 /* Look to see if we have the file preloaded */ 348 modptr = preload_search_by_name(filename); 349 if (modptr == NULL) 350 return ENOENT; 351 352 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 353 baseptr = preload_search_info(modptr, MODINFO_ADDR); 354 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 355 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 356 MODINFOMD_ELFHDR); 357 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 358 MODINFOMD_SHDR); 359 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) 360 " obj module") != 0 && 361 strcmp(type, "elf obj module") != 0)) { 362 return (EFTYPE); 363 } 364 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 365 shdr == NULL) 366 return (EINVAL); 367 368 lf = linker_make_file(filename, &link_elf_class); 369 if (lf == NULL) 370 return (ENOMEM); 371 372 ef = (elf_file_t)lf; 373 ef->preloaded = 1; 374 ef->address = *(caddr_t *)baseptr; 375 lf->address = *(caddr_t *)baseptr; 376 lf->size = *(size_t *)sizeptr; 377 378 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 379 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 380 hdr->e_ident[EI_VERSION] != EV_CURRENT || 381 hdr->e_version != EV_CURRENT || 382 hdr->e_type != ET_REL || 383 hdr->e_machine != ELF_TARG_MACH) { 384 error = EFTYPE; 385 goto out; 386 } 387 ef->e_shdr = shdr; 388 389 /* Scan the section header for information and table sizing. */ 390 symtabindex = -1; 391 symstrindex = -1; 392 for (i = 0; i < hdr->e_shnum; i++) { 393 switch (shdr[i].sh_type) { 394 case SHT_PROGBITS: 395 case SHT_NOBITS: 396 #ifdef __amd64__ 397 case SHT_X86_64_UNWIND: 398 #endif 399 case SHT_INIT_ARRAY: 400 case SHT_FINI_ARRAY: 401 /* Ignore sections not loaded by the loader. */ 402 if (shdr[i].sh_addr == 0) 403 break; 404 ef->nprogtab++; 405 break; 406 case SHT_SYMTAB: 407 symtabindex = i; 408 symstrindex = shdr[i].sh_link; 409 break; 410 case SHT_REL: 411 /* 412 * Ignore relocation tables for sections not 413 * loaded by the loader. 414 */ 415 if (shdr[shdr[i].sh_info].sh_addr == 0) 416 break; 417 ef->nreltab++; 418 break; 419 case SHT_RELA: 420 if (shdr[shdr[i].sh_info].sh_addr == 0) 421 break; 422 ef->nrelatab++; 423 break; 424 } 425 } 426 427 shstrindex = hdr->e_shstrndx; 428 if (ef->nprogtab == 0 || symstrindex < 0 || 429 symstrindex >= hdr->e_shnum || 430 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 431 shstrindex >= hdr->e_shnum || 432 shdr[shstrindex].sh_type != SHT_STRTAB) { 433 printf("%s: bad/missing section headers\n", filename); 434 error = ENOEXEC; 435 goto out; 436 } 437 438 /* Allocate space for tracking the load chunks */ 439 if (ef->nprogtab != 0) 440 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 441 M_LINKER, M_WAITOK | M_ZERO); 442 if (ef->nreltab != 0) 443 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 444 M_LINKER, M_WAITOK | M_ZERO); 445 if (ef->nrelatab != 0) 446 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 447 M_LINKER, M_WAITOK | M_ZERO); 448 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 449 (ef->nreltab != 0 && ef->reltab == NULL) || 450 (ef->nrelatab != 0 && ef->relatab == NULL)) { 451 error = ENOMEM; 452 goto out; 453 } 454 455 /* XXX, relocate the sh_addr fields saved by the loader. */ 456 off = 0; 457 for (i = 0; i < hdr->e_shnum; i++) { 458 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 459 off = shdr[i].sh_addr; 460 } 461 for (i = 0; i < hdr->e_shnum; i++) { 462 if (shdr[i].sh_addr != 0) 463 shdr[i].sh_addr = shdr[i].sh_addr - off + 464 (Elf_Addr)ef->address; 465 } 466 467 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 468 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 469 ef->ddbstrcnt = shdr[symstrindex].sh_size; 470 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 471 ef->shstrcnt = shdr[shstrindex].sh_size; 472 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 473 474 /* Now fill out progtab and the relocation tables. */ 475 pb = 0; 476 rl = 0; 477 ra = 0; 478 for (i = 0; i < hdr->e_shnum; i++) { 479 switch (shdr[i].sh_type) { 480 case SHT_PROGBITS: 481 case SHT_NOBITS: 482 #ifdef __amd64__ 483 case SHT_X86_64_UNWIND: 484 #endif 485 case SHT_INIT_ARRAY: 486 case SHT_FINI_ARRAY: 487 if (shdr[i].sh_addr == 0) 488 break; 489 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 490 if (shdr[i].sh_type == SHT_PROGBITS) 491 ef->progtab[pb].name = "<<PROGBITS>>"; 492 #ifdef __amd64__ 493 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 494 ef->progtab[pb].name = "<<UNWIND>>"; 495 #endif 496 else if (shdr[i].sh_type == SHT_INIT_ARRAY) 497 ef->progtab[pb].name = "<<INIT_ARRAY>>"; 498 else if (shdr[i].sh_type == SHT_FINI_ARRAY) 499 ef->progtab[pb].name = "<<FINI_ARRAY>>"; 500 else 501 ef->progtab[pb].name = "<<NOBITS>>"; 502 ef->progtab[pb].size = shdr[i].sh_size; 503 ef->progtab[pb].flags = shdr[i].sh_flags; 504 ef->progtab[pb].sec = i; 505 if (ef->shstrtab && shdr[i].sh_name != 0) 506 ef->progtab[pb].name = 507 ef->shstrtab + shdr[i].sh_name; 508 if (ef->progtab[pb].name != NULL && 509 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 510 void *dpcpu; 511 512 dpcpu = dpcpu_alloc(shdr[i].sh_size); 513 if (dpcpu == NULL) { 514 printf("%s: pcpu module space is out " 515 "of space; cannot allocate %#jx " 516 "for %s\n", __func__, 517 (uintmax_t)shdr[i].sh_size, 518 filename); 519 error = ENOSPC; 520 goto out; 521 } 522 memcpy(dpcpu, ef->progtab[pb].addr, 523 ef->progtab[pb].size); 524 dpcpu_copy(dpcpu, shdr[i].sh_size); 525 ef->progtab[pb].addr = dpcpu; 526 #ifdef VIMAGE 527 } else if (ef->progtab[pb].name != NULL && 528 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 529 void *vnet_data; 530 531 vnet_data = vnet_data_alloc(shdr[i].sh_size); 532 if (vnet_data == NULL) { 533 printf("%s: vnet module space is out " 534 "of space; cannot allocate %#jx " 535 "for %s\n", __func__, 536 (uintmax_t)shdr[i].sh_size, 537 filename); 538 error = ENOSPC; 539 goto out; 540 } 541 memcpy(vnet_data, ef->progtab[pb].addr, 542 ef->progtab[pb].size); 543 vnet_data_copy(vnet_data, shdr[i].sh_size); 544 ef->progtab[pb].addr = vnet_data; 545 #endif 546 } else if ((ef->progtab[pb].name != NULL && 547 strcmp(ef->progtab[pb].name, ".ctors") == 0) || 548 shdr[i].sh_type == SHT_INIT_ARRAY) { 549 if (lf->ctors_addr != 0) { 550 printf( 551 "%s: multiple ctor sections in %s\n", 552 __func__, filename); 553 } else { 554 lf->ctors_addr = ef->progtab[pb].addr; 555 lf->ctors_size = shdr[i].sh_size; 556 } 557 } else if ((ef->progtab[pb].name != NULL && 558 strcmp(ef->progtab[pb].name, ".dtors") == 0) || 559 shdr[i].sh_type == SHT_FINI_ARRAY) { 560 if (lf->dtors_addr != 0) { 561 printf( 562 "%s: multiple dtor sections in %s\n", 563 __func__, filename); 564 } else { 565 lf->dtors_addr = ef->progtab[pb].addr; 566 lf->dtors_size = shdr[i].sh_size; 567 } 568 } 569 570 /* Update all symbol values with the offset. */ 571 for (j = 0; j < ef->ddbsymcnt; j++) { 572 es = &ef->ddbsymtab[j]; 573 if (es->st_shndx != i) 574 continue; 575 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 576 } 577 pb++; 578 break; 579 case SHT_REL: 580 if (shdr[shdr[i].sh_info].sh_addr == 0) 581 break; 582 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 583 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 584 ef->reltab[rl].sec = shdr[i].sh_info; 585 rl++; 586 break; 587 case SHT_RELA: 588 if (shdr[shdr[i].sh_info].sh_addr == 0) 589 break; 590 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 591 ef->relatab[ra].nrela = 592 shdr[i].sh_size / sizeof(Elf_Rela); 593 ef->relatab[ra].sec = shdr[i].sh_info; 594 ra++; 595 break; 596 } 597 } 598 if (pb != ef->nprogtab) { 599 printf("%s: lost progbits\n", filename); 600 error = ENOEXEC; 601 goto out; 602 } 603 if (rl != ef->nreltab) { 604 printf("%s: lost reltab\n", filename); 605 error = ENOEXEC; 606 goto out; 607 } 608 if (ra != ef->nrelatab) { 609 printf("%s: lost relatab\n", filename); 610 error = ENOEXEC; 611 goto out; 612 } 613 614 /* 615 * The file needs to be writeable and executable while applying 616 * relocations. Mapping protections are applied once relocation 617 * processing is complete. 618 */ 619 link_elf_protect_range(ef, (vm_offset_t)ef->address, 620 round_page((vm_offset_t)ef->address + ef->lf.size), VM_PROT_ALL); 621 622 /* Local intra-module relocations */ 623 error = link_elf_reloc_local(lf, false); 624 if (error != 0) 625 goto out; 626 *result = lf; 627 return (0); 628 629 out: 630 /* preload not done this way */ 631 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 632 return (error); 633 } 634 635 static void 636 link_elf_invoke_cbs(caddr_t addr, size_t size) 637 { 638 void (**ctor)(void); 639 size_t i, cnt; 640 641 if (addr == NULL || size == 0) 642 return; 643 cnt = size / sizeof(*ctor); 644 ctor = (void *)addr; 645 for (i = 0; i < cnt; i++) { 646 if (ctor[i] != NULL) 647 (*ctor[i])(); 648 } 649 } 650 651 static int 652 link_elf_link_preload_finish(linker_file_t lf) 653 { 654 elf_file_t ef; 655 int error; 656 657 ef = (elf_file_t)lf; 658 error = relocate_file(ef); 659 if (error) 660 return (error); 661 662 /* Notify MD code that a module is being loaded. */ 663 error = elf_cpu_load_file(lf); 664 if (error) 665 return (error); 666 667 #if defined(__i386__) || defined(__amd64__) 668 /* Now ifuncs. */ 669 error = link_elf_reloc_local(lf, true); 670 if (error != 0) 671 return (error); 672 #endif 673 674 /* Apply protections now that relocation processing is complete. */ 675 link_elf_protect(ef); 676 677 link_elf_invoke_cbs(lf->ctors_addr, lf->ctors_size); 678 return (0); 679 } 680 681 static int 682 link_elf_load_file(linker_class_t cls, const char *filename, 683 linker_file_t *result) 684 { 685 struct nameidata *nd; 686 struct thread *td = curthread; /* XXX */ 687 Elf_Ehdr *hdr; 688 Elf_Shdr *shdr; 689 Elf_Sym *es; 690 int nbytes, i, j; 691 vm_offset_t mapbase; 692 size_t mapsize; 693 int error = 0; 694 ssize_t resid; 695 int flags; 696 elf_file_t ef; 697 linker_file_t lf; 698 int symtabindex; 699 int symstrindex; 700 int shstrindex; 701 int nsym; 702 int pb, rl, ra; 703 int alignmask; 704 705 shdr = NULL; 706 lf = NULL; 707 mapsize = 0; 708 hdr = NULL; 709 710 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 711 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename); 712 flags = FREAD; 713 error = vn_open(nd, &flags, 0, NULL); 714 if (error) { 715 free(nd, M_TEMP); 716 return error; 717 } 718 NDFREE_PNBUF(nd); 719 if (nd->ni_vp->v_type != VREG) { 720 error = ENOEXEC; 721 goto out; 722 } 723 #ifdef MAC 724 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 725 if (error) { 726 goto out; 727 } 728 #endif 729 730 /* Read the elf header from the file. */ 731 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 732 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 733 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 734 &resid, td); 735 if (error) 736 goto out; 737 if (resid != 0){ 738 error = ENOEXEC; 739 goto out; 740 } 741 742 if (!IS_ELF(*hdr)) { 743 error = ENOEXEC; 744 goto out; 745 } 746 747 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 748 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 749 link_elf_error(filename, "Unsupported file layout"); 750 error = ENOEXEC; 751 goto out; 752 } 753 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 754 || hdr->e_version != EV_CURRENT) { 755 link_elf_error(filename, "Unsupported file version"); 756 error = ENOEXEC; 757 goto out; 758 } 759 if (hdr->e_type != ET_REL) { 760 error = ENOSYS; 761 goto out; 762 } 763 if (hdr->e_machine != ELF_TARG_MACH) { 764 link_elf_error(filename, "Unsupported machine"); 765 error = ENOEXEC; 766 goto out; 767 } 768 769 lf = linker_make_file(filename, &link_elf_class); 770 if (!lf) { 771 error = ENOMEM; 772 goto out; 773 } 774 ef = (elf_file_t) lf; 775 ef->nprogtab = 0; 776 ef->e_shdr = 0; 777 ef->nreltab = 0; 778 ef->nrelatab = 0; 779 780 /* Allocate and read in the section header */ 781 nbytes = hdr->e_shnum * hdr->e_shentsize; 782 if (nbytes == 0 || hdr->e_shoff == 0 || 783 hdr->e_shentsize != sizeof(Elf_Shdr)) { 784 error = ENOEXEC; 785 goto out; 786 } 787 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 788 ef->e_shdr = shdr; 789 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 790 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 791 NOCRED, &resid, td); 792 if (error) 793 goto out; 794 if (resid) { 795 error = ENOEXEC; 796 goto out; 797 } 798 799 /* Scan the section header for information and table sizing. */ 800 nsym = 0; 801 symtabindex = -1; 802 symstrindex = -1; 803 for (i = 0; i < hdr->e_shnum; i++) { 804 if (shdr[i].sh_size == 0) 805 continue; 806 switch (shdr[i].sh_type) { 807 case SHT_PROGBITS: 808 case SHT_NOBITS: 809 #ifdef __amd64__ 810 case SHT_X86_64_UNWIND: 811 #endif 812 case SHT_INIT_ARRAY: 813 case SHT_FINI_ARRAY: 814 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 815 break; 816 ef->nprogtab++; 817 break; 818 case SHT_SYMTAB: 819 nsym++; 820 symtabindex = i; 821 symstrindex = shdr[i].sh_link; 822 break; 823 case SHT_REL: 824 /* 825 * Ignore relocation tables for unallocated 826 * sections. 827 */ 828 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 829 break; 830 ef->nreltab++; 831 break; 832 case SHT_RELA: 833 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 834 break; 835 ef->nrelatab++; 836 break; 837 case SHT_STRTAB: 838 break; 839 } 840 } 841 if (ef->nprogtab == 0) { 842 link_elf_error(filename, "file has no contents"); 843 error = ENOEXEC; 844 goto out; 845 } 846 if (nsym != 1) { 847 /* Only allow one symbol table for now */ 848 link_elf_error(filename, 849 "file must have exactly one symbol table"); 850 error = ENOEXEC; 851 goto out; 852 } 853 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 854 shdr[symstrindex].sh_type != SHT_STRTAB) { 855 link_elf_error(filename, "file has invalid symbol strings"); 856 error = ENOEXEC; 857 goto out; 858 } 859 860 /* Allocate space for tracking the load chunks */ 861 if (ef->nprogtab != 0) 862 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 863 M_LINKER, M_WAITOK | M_ZERO); 864 if (ef->nreltab != 0) 865 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 866 M_LINKER, M_WAITOK | M_ZERO); 867 if (ef->nrelatab != 0) 868 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 869 M_LINKER, M_WAITOK | M_ZERO); 870 871 if (symtabindex == -1) { 872 link_elf_error(filename, "lost symbol table index"); 873 error = ENOEXEC; 874 goto out; 875 } 876 /* Allocate space for and load the symbol table */ 877 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 878 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 879 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 880 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 881 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 882 &resid, td); 883 if (error) 884 goto out; 885 if (resid != 0){ 886 error = EINVAL; 887 goto out; 888 } 889 890 /* Allocate space for and load the symbol strings */ 891 ef->ddbstrcnt = shdr[symstrindex].sh_size; 892 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 893 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 894 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 895 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 896 &resid, td); 897 if (error) 898 goto out; 899 if (resid != 0){ 900 error = EINVAL; 901 goto out; 902 } 903 904 /* Do we have a string table for the section names? */ 905 shstrindex = -1; 906 if (hdr->e_shstrndx != 0 && 907 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 908 shstrindex = hdr->e_shstrndx; 909 ef->shstrcnt = shdr[shstrindex].sh_size; 910 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 911 M_WAITOK); 912 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 913 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 914 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 915 &resid, td); 916 if (error) 917 goto out; 918 if (resid != 0){ 919 error = EINVAL; 920 goto out; 921 } 922 } 923 924 /* Size up code/data(progbits) and bss(nobits). */ 925 alignmask = 0; 926 for (i = 0; i < hdr->e_shnum; i++) { 927 if (shdr[i].sh_size == 0) 928 continue; 929 switch (shdr[i].sh_type) { 930 case SHT_PROGBITS: 931 case SHT_NOBITS: 932 #ifdef __amd64__ 933 case SHT_X86_64_UNWIND: 934 #endif 935 case SHT_INIT_ARRAY: 936 case SHT_FINI_ARRAY: 937 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 938 break; 939 alignmask = shdr[i].sh_addralign - 1; 940 mapsize += alignmask; 941 mapsize &= ~alignmask; 942 mapsize += shdr[i].sh_size; 943 break; 944 } 945 } 946 947 /* 948 * We know how much space we need for the text/data/bss/etc. 949 * This stuff needs to be in a single chunk so that profiling etc 950 * can get the bounds and gdb can associate offsets with modules 951 */ 952 ef->object = vm_pager_allocate(OBJT_PHYS, NULL, round_page(mapsize), 953 VM_PROT_ALL, 0, thread0.td_ucred); 954 if (ef->object == NULL) { 955 error = ENOMEM; 956 goto out; 957 } 958 #if VM_NRESERVLEVEL > 0 959 vm_object_color(ef->object, 0); 960 #endif 961 962 /* 963 * In order to satisfy amd64's architectural requirements on the 964 * location of code and data in the kernel's address space, request a 965 * mapping that is above the kernel. 966 * 967 * Protections will be restricted once relocations are applied. 968 */ 969 #ifdef __amd64__ 970 mapbase = KERNBASE; 971 #else 972 mapbase = VM_MIN_KERNEL_ADDRESS; 973 #endif 974 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 975 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 976 VM_PROT_ALL, 0); 977 if (error != KERN_SUCCESS) { 978 vm_object_deallocate(ef->object); 979 ef->object = NULL; 980 error = ENOMEM; 981 goto out; 982 } 983 984 /* Wire the pages */ 985 error = vm_map_wire(kernel_map, mapbase, 986 mapbase + round_page(mapsize), 987 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 988 if (error != KERN_SUCCESS) { 989 error = ENOMEM; 990 goto out; 991 } 992 993 /* Inform the kld system about the situation */ 994 lf->address = ef->address = (caddr_t)mapbase; 995 lf->size = mapsize; 996 997 /* 998 * Now load code/data(progbits), zero bss(nobits), allocate space for 999 * and load relocs 1000 */ 1001 pb = 0; 1002 rl = 0; 1003 ra = 0; 1004 alignmask = 0; 1005 for (i = 0; i < hdr->e_shnum; i++) { 1006 if (shdr[i].sh_size == 0) 1007 continue; 1008 switch (shdr[i].sh_type) { 1009 case SHT_PROGBITS: 1010 case SHT_NOBITS: 1011 #ifdef __amd64__ 1012 case SHT_X86_64_UNWIND: 1013 #endif 1014 case SHT_INIT_ARRAY: 1015 case SHT_FINI_ARRAY: 1016 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 1017 break; 1018 alignmask = shdr[i].sh_addralign - 1; 1019 mapbase += alignmask; 1020 mapbase &= ~alignmask; 1021 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 1022 ef->progtab[pb].name = 1023 ef->shstrtab + shdr[i].sh_name; 1024 if (!strcmp(ef->progtab[pb].name, ".ctors") || 1025 shdr[i].sh_type == SHT_INIT_ARRAY) { 1026 if (lf->ctors_addr != 0) { 1027 printf( 1028 "%s: multiple ctor sections in %s\n", 1029 __func__, filename); 1030 } else { 1031 lf->ctors_addr = 1032 (caddr_t)mapbase; 1033 lf->ctors_size = 1034 shdr[i].sh_size; 1035 } 1036 } else if (!strcmp(ef->progtab[pb].name, 1037 ".dtors") || 1038 shdr[i].sh_type == SHT_FINI_ARRAY) { 1039 if (lf->dtors_addr != 0) { 1040 printf( 1041 "%s: multiple dtor sections in %s\n", 1042 __func__, filename); 1043 } else { 1044 lf->dtors_addr = 1045 (caddr_t)mapbase; 1046 lf->dtors_size = 1047 shdr[i].sh_size; 1048 } 1049 } 1050 } else if (shdr[i].sh_type == SHT_PROGBITS) 1051 ef->progtab[pb].name = "<<PROGBITS>>"; 1052 #ifdef __amd64__ 1053 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 1054 ef->progtab[pb].name = "<<UNWIND>>"; 1055 #endif 1056 else 1057 ef->progtab[pb].name = "<<NOBITS>>"; 1058 if (ef->progtab[pb].name != NULL && 1059 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 1060 ef->progtab[pb].addr = 1061 dpcpu_alloc(shdr[i].sh_size); 1062 if (ef->progtab[pb].addr == NULL) { 1063 printf("%s: pcpu module space is out " 1064 "of space; cannot allocate %#jx " 1065 "for %s\n", __func__, 1066 (uintmax_t)shdr[i].sh_size, 1067 filename); 1068 } 1069 } 1070 #ifdef VIMAGE 1071 else if (ef->progtab[pb].name != NULL && 1072 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 1073 ef->progtab[pb].addr = 1074 vnet_data_alloc(shdr[i].sh_size); 1075 if (ef->progtab[pb].addr == NULL) { 1076 printf("%s: vnet module space is out " 1077 "of space; cannot allocate %#jx " 1078 "for %s\n", __func__, 1079 (uintmax_t)shdr[i].sh_size, 1080 filename); 1081 } 1082 } 1083 #endif 1084 else 1085 ef->progtab[pb].addr = 1086 (void *)(uintptr_t)mapbase; 1087 if (ef->progtab[pb].addr == NULL) { 1088 error = ENOSPC; 1089 goto out; 1090 } 1091 ef->progtab[pb].size = shdr[i].sh_size; 1092 ef->progtab[pb].flags = shdr[i].sh_flags; 1093 ef->progtab[pb].sec = i; 1094 if (shdr[i].sh_type == SHT_PROGBITS 1095 #ifdef __amd64__ 1096 || shdr[i].sh_type == SHT_X86_64_UNWIND 1097 #endif 1098 ) { 1099 error = vn_rdwr(UIO_READ, nd->ni_vp, 1100 ef->progtab[pb].addr, 1101 shdr[i].sh_size, shdr[i].sh_offset, 1102 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 1103 NOCRED, &resid, td); 1104 if (error) 1105 goto out; 1106 if (resid != 0){ 1107 error = EINVAL; 1108 goto out; 1109 } 1110 /* Initialize the per-cpu or vnet area. */ 1111 if (ef->progtab[pb].addr != (void *)mapbase && 1112 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 1113 dpcpu_copy(ef->progtab[pb].addr, 1114 shdr[i].sh_size); 1115 #ifdef VIMAGE 1116 else if (ef->progtab[pb].addr != 1117 (void *)mapbase && 1118 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) 1119 vnet_data_copy(ef->progtab[pb].addr, 1120 shdr[i].sh_size); 1121 #endif 1122 } else 1123 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 1124 1125 /* Update all symbol values with the offset. */ 1126 for (j = 0; j < ef->ddbsymcnt; j++) { 1127 es = &ef->ddbsymtab[j]; 1128 if (es->st_shndx != i) 1129 continue; 1130 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 1131 } 1132 mapbase += shdr[i].sh_size; 1133 pb++; 1134 break; 1135 case SHT_REL: 1136 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 1137 break; 1138 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 1139 M_WAITOK); 1140 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 1141 ef->reltab[rl].sec = shdr[i].sh_info; 1142 error = vn_rdwr(UIO_READ, nd->ni_vp, 1143 (void *)ef->reltab[rl].rel, 1144 shdr[i].sh_size, shdr[i].sh_offset, 1145 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1146 &resid, td); 1147 if (error) 1148 goto out; 1149 if (resid != 0){ 1150 error = EINVAL; 1151 goto out; 1152 } 1153 rl++; 1154 break; 1155 case SHT_RELA: 1156 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 1157 break; 1158 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 1159 M_WAITOK); 1160 ef->relatab[ra].nrela = 1161 shdr[i].sh_size / sizeof(Elf_Rela); 1162 ef->relatab[ra].sec = shdr[i].sh_info; 1163 error = vn_rdwr(UIO_READ, nd->ni_vp, 1164 (void *)ef->relatab[ra].rela, 1165 shdr[i].sh_size, shdr[i].sh_offset, 1166 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1167 &resid, td); 1168 if (error) 1169 goto out; 1170 if (resid != 0){ 1171 error = EINVAL; 1172 goto out; 1173 } 1174 ra++; 1175 break; 1176 } 1177 } 1178 if (pb != ef->nprogtab) { 1179 link_elf_error(filename, "lost progbits"); 1180 error = ENOEXEC; 1181 goto out; 1182 } 1183 if (rl != ef->nreltab) { 1184 link_elf_error(filename, "lost reltab"); 1185 error = ENOEXEC; 1186 goto out; 1187 } 1188 if (ra != ef->nrelatab) { 1189 link_elf_error(filename, "lost relatab"); 1190 error = ENOEXEC; 1191 goto out; 1192 } 1193 if (mapbase != (vm_offset_t)ef->address + mapsize) { 1194 printf( 1195 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 1196 filename != NULL ? filename : "<none>", 1197 (u_long)mapbase, ef->address, (u_long)mapsize, 1198 (u_long)(vm_offset_t)ef->address + mapsize); 1199 error = ENOMEM; 1200 goto out; 1201 } 1202 1203 /* Local intra-module relocations */ 1204 error = link_elf_reloc_local(lf, false); 1205 if (error != 0) 1206 goto out; 1207 1208 /* Pull in dependencies */ 1209 VOP_UNLOCK(nd->ni_vp); 1210 error = linker_load_dependencies(lf); 1211 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 1212 if (error) 1213 goto out; 1214 1215 /* External relocations */ 1216 error = relocate_file(ef); 1217 if (error) 1218 goto out; 1219 1220 /* Notify MD code that a module is being loaded. */ 1221 error = elf_cpu_load_file(lf); 1222 if (error) 1223 goto out; 1224 1225 #if defined(__i386__) || defined(__amd64__) 1226 /* Now ifuncs. */ 1227 error = link_elf_reloc_local(lf, true); 1228 if (error != 0) 1229 goto out; 1230 #endif 1231 1232 link_elf_protect(ef); 1233 link_elf_invoke_cbs(lf->ctors_addr, lf->ctors_size); 1234 *result = lf; 1235 1236 out: 1237 VOP_UNLOCK(nd->ni_vp); 1238 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 1239 free(nd, M_TEMP); 1240 if (error && lf) 1241 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1242 free(hdr, M_LINKER); 1243 1244 return error; 1245 } 1246 1247 static void 1248 link_elf_unload_file(linker_file_t file) 1249 { 1250 elf_file_t ef = (elf_file_t) file; 1251 u_int i; 1252 1253 link_elf_invoke_cbs(file->dtors_addr, file->dtors_size); 1254 1255 /* Notify MD code that a module is being unloaded. */ 1256 elf_cpu_unload_file(file); 1257 1258 if (ef->progtab) { 1259 for (i = 0; i < ef->nprogtab; i++) { 1260 if (ef->progtab[i].size == 0) 1261 continue; 1262 if (ef->progtab[i].name == NULL) 1263 continue; 1264 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 1265 dpcpu_free(ef->progtab[i].addr, 1266 ef->progtab[i].size); 1267 #ifdef VIMAGE 1268 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 1269 vnet_data_free(ef->progtab[i].addr, 1270 ef->progtab[i].size); 1271 #endif 1272 } 1273 } 1274 if (ef->preloaded) { 1275 free(ef->reltab, M_LINKER); 1276 free(ef->relatab, M_LINKER); 1277 free(ef->progtab, M_LINKER); 1278 free(ef->ctftab, M_LINKER); 1279 free(ef->ctfoff, M_LINKER); 1280 free(ef->typoff, M_LINKER); 1281 if (file->pathname != NULL) 1282 preload_delete_name(file->pathname); 1283 return; 1284 } 1285 1286 for (i = 0; i < ef->nreltab; i++) 1287 free(ef->reltab[i].rel, M_LINKER); 1288 for (i = 0; i < ef->nrelatab; i++) 1289 free(ef->relatab[i].rela, M_LINKER); 1290 free(ef->reltab, M_LINKER); 1291 free(ef->relatab, M_LINKER); 1292 free(ef->progtab, M_LINKER); 1293 1294 if (ef->object != NULL) 1295 vm_map_remove(kernel_map, (vm_offset_t)ef->address, 1296 (vm_offset_t)ef->address + ptoa(ef->object->size)); 1297 free(ef->e_shdr, M_LINKER); 1298 free(ef->ddbsymtab, M_LINKER); 1299 free(ef->ddbstrtab, M_LINKER); 1300 free(ef->shstrtab, M_LINKER); 1301 free(ef->ctftab, M_LINKER); 1302 free(ef->ctfoff, M_LINKER); 1303 free(ef->typoff, M_LINKER); 1304 } 1305 1306 static const char * 1307 symbol_name(elf_file_t ef, Elf_Size r_info) 1308 { 1309 const Elf_Sym *ref; 1310 1311 if (ELF_R_SYM(r_info)) { 1312 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1313 return ef->ddbstrtab + ref->st_name; 1314 } else 1315 return NULL; 1316 } 1317 1318 static Elf_Addr 1319 findbase(elf_file_t ef, int sec) 1320 { 1321 int i; 1322 Elf_Addr base = 0; 1323 1324 for (i = 0; i < ef->nprogtab; i++) { 1325 if (sec == ef->progtab[i].sec) { 1326 base = (Elf_Addr)ef->progtab[i].addr; 1327 break; 1328 } 1329 } 1330 return base; 1331 } 1332 1333 static int 1334 relocate_file1(elf_file_t ef, bool ifuncs) 1335 { 1336 const Elf_Rel *rellim; 1337 const Elf_Rel *rel; 1338 const Elf_Rela *relalim; 1339 const Elf_Rela *rela; 1340 const char *symname; 1341 const Elf_Sym *sym; 1342 int i; 1343 Elf_Size symidx; 1344 Elf_Addr base; 1345 1346 /* Perform relocations without addend if there are any: */ 1347 for (i = 0; i < ef->nreltab; i++) { 1348 rel = ef->reltab[i].rel; 1349 if (rel == NULL) { 1350 link_elf_error(ef->lf.filename, "lost a reltab!"); 1351 return (ENOEXEC); 1352 } 1353 rellim = rel + ef->reltab[i].nrel; 1354 base = findbase(ef, ef->reltab[i].sec); 1355 if (base == 0) { 1356 link_elf_error(ef->lf.filename, "lost base for reltab"); 1357 return (ENOEXEC); 1358 } 1359 for ( ; rel < rellim; rel++) { 1360 symidx = ELF_R_SYM(rel->r_info); 1361 if (symidx >= ef->ddbsymcnt) 1362 continue; 1363 sym = ef->ddbsymtab + symidx; 1364 /* Local relocs are already done */ 1365 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1366 continue; 1367 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1368 elf_is_ifunc_reloc(rel->r_info)) != ifuncs) 1369 continue; 1370 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1371 elf_obj_lookup)) { 1372 symname = symbol_name(ef, rel->r_info); 1373 printf("link_elf_obj: symbol %s undefined\n", 1374 symname); 1375 return (ENOENT); 1376 } 1377 } 1378 } 1379 1380 /* Perform relocations with addend if there are any: */ 1381 for (i = 0; i < ef->nrelatab; i++) { 1382 rela = ef->relatab[i].rela; 1383 if (rela == NULL) { 1384 link_elf_error(ef->lf.filename, "lost a relatab!"); 1385 return (ENOEXEC); 1386 } 1387 relalim = rela + ef->relatab[i].nrela; 1388 base = findbase(ef, ef->relatab[i].sec); 1389 if (base == 0) { 1390 link_elf_error(ef->lf.filename, 1391 "lost base for relatab"); 1392 return (ENOEXEC); 1393 } 1394 for ( ; rela < relalim; rela++) { 1395 symidx = ELF_R_SYM(rela->r_info); 1396 if (symidx >= ef->ddbsymcnt) 1397 continue; 1398 sym = ef->ddbsymtab + symidx; 1399 /* Local relocs are already done */ 1400 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1401 continue; 1402 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1403 elf_is_ifunc_reloc(rela->r_info)) != ifuncs) 1404 continue; 1405 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1406 elf_obj_lookup)) { 1407 symname = symbol_name(ef, rela->r_info); 1408 printf("link_elf_obj: symbol %s undefined\n", 1409 symname); 1410 return (ENOENT); 1411 } 1412 } 1413 } 1414 1415 /* 1416 * Only clean SHN_FBSD_CACHED for successful return. If we 1417 * modified symbol table for the object but found an 1418 * unresolved symbol, there is no reason to roll back. 1419 */ 1420 elf_obj_cleanup_globals_cache(ef); 1421 1422 return (0); 1423 } 1424 1425 static int 1426 relocate_file(elf_file_t ef) 1427 { 1428 int error; 1429 1430 error = relocate_file1(ef, false); 1431 if (error == 0) 1432 error = relocate_file1(ef, true); 1433 return (error); 1434 } 1435 1436 static int 1437 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym, 1438 bool see_local) 1439 { 1440 elf_file_t ef = (elf_file_t)lf; 1441 const Elf_Sym *symp; 1442 const char *strp; 1443 int i; 1444 1445 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1446 strp = ef->ddbstrtab + symp->st_name; 1447 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1448 if (see_local || 1449 ELF_ST_BIND(symp->st_info) == STB_GLOBAL) { 1450 *sym = (c_linker_sym_t) symp; 1451 return (0); 1452 } 1453 return (ENOENT); 1454 } 1455 } 1456 return (ENOENT); 1457 } 1458 1459 static int 1460 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1461 { 1462 return (link_elf_lookup_symbol1(lf, name, sym, 1463 link_elf_obj_leak_locals)); 1464 } 1465 1466 static int 1467 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name, 1468 c_linker_sym_t *sym) 1469 { 1470 return (link_elf_lookup_symbol1(lf, name, sym, true)); 1471 } 1472 1473 static int 1474 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym, 1475 linker_symval_t *symval, bool see_local) 1476 { 1477 elf_file_t ef; 1478 const Elf_Sym *es; 1479 caddr_t val; 1480 1481 ef = (elf_file_t) lf; 1482 es = (const Elf_Sym*) sym; 1483 val = (caddr_t)es->st_value; 1484 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1485 if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL) 1486 return (ENOENT); 1487 symval->name = ef->ddbstrtab + es->st_name; 1488 val = (caddr_t)es->st_value; 1489 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1490 val = ((caddr_t (*)(void))val)(); 1491 symval->value = val; 1492 symval->size = es->st_size; 1493 return (0); 1494 } 1495 return (ENOENT); 1496 } 1497 1498 static int 1499 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1500 linker_symval_t *symval) 1501 { 1502 return (link_elf_symbol_values1(lf, sym, symval, 1503 link_elf_obj_leak_locals)); 1504 } 1505 1506 static int 1507 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1508 linker_symval_t *symval) 1509 { 1510 return (link_elf_symbol_values1(lf, sym, symval, true)); 1511 } 1512 1513 static int 1514 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1515 c_linker_sym_t *sym, long *diffp) 1516 { 1517 elf_file_t ef = (elf_file_t)lf; 1518 u_long off = (uintptr_t)(void *)value; 1519 u_long diff = off; 1520 u_long st_value; 1521 const Elf_Sym *es; 1522 const Elf_Sym *best = NULL; 1523 int i; 1524 1525 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1526 if (es->st_name == 0) 1527 continue; 1528 st_value = es->st_value; 1529 if (off >= st_value) { 1530 if (off - st_value < diff) { 1531 diff = off - st_value; 1532 best = es; 1533 if (diff == 0) 1534 break; 1535 } else if (off - st_value == diff) { 1536 best = es; 1537 } 1538 } 1539 } 1540 if (best == NULL) 1541 *diffp = off; 1542 else 1543 *diffp = diff; 1544 *sym = (c_linker_sym_t) best; 1545 1546 return (0); 1547 } 1548 1549 /* 1550 * Look up a linker set on an ELF system. 1551 */ 1552 static int 1553 link_elf_lookup_set(linker_file_t lf, const char *name, 1554 void ***startp, void ***stopp, int *countp) 1555 { 1556 elf_file_t ef = (elf_file_t)lf; 1557 void **start, **stop; 1558 int i, count; 1559 1560 /* Relative to section number */ 1561 for (i = 0; i < ef->nprogtab; i++) { 1562 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1563 strcmp(ef->progtab[i].name + 4, name) == 0) { 1564 start = (void **)ef->progtab[i].addr; 1565 stop = (void **)((char *)ef->progtab[i].addr + 1566 ef->progtab[i].size); 1567 count = stop - start; 1568 if (startp) 1569 *startp = start; 1570 if (stopp) 1571 *stopp = stop; 1572 if (countp) 1573 *countp = count; 1574 return (0); 1575 } 1576 } 1577 return (ESRCH); 1578 } 1579 1580 static int 1581 link_elf_each_function_name(linker_file_t file, 1582 int (*callback)(const char *, void *), void *opaque) 1583 { 1584 elf_file_t ef = (elf_file_t)file; 1585 const Elf_Sym *symp; 1586 int i, error; 1587 1588 /* Exhaustive search */ 1589 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1590 if (symp->st_value != 0 && 1591 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1592 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1593 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1594 if (error) 1595 return (error); 1596 } 1597 } 1598 return (0); 1599 } 1600 1601 static int 1602 link_elf_each_function_nameval(linker_file_t file, 1603 linker_function_nameval_callback_t callback, void *opaque) 1604 { 1605 linker_symval_t symval; 1606 elf_file_t ef = (elf_file_t)file; 1607 const Elf_Sym *symp; 1608 int i, error; 1609 1610 /* Exhaustive search */ 1611 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1612 if (symp->st_value != 0 && 1613 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1614 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1615 error = link_elf_debug_symbol_values(file, 1616 (c_linker_sym_t)symp, &symval); 1617 if (error == 0) 1618 error = callback(file, i, &symval, opaque); 1619 if (error != 0) 1620 return (error); 1621 } 1622 } 1623 return (0); 1624 } 1625 1626 static void 1627 elf_obj_cleanup_globals_cache(elf_file_t ef) 1628 { 1629 Elf_Sym *sym; 1630 Elf_Size i; 1631 1632 for (i = 0; i < ef->ddbsymcnt; i++) { 1633 sym = ef->ddbsymtab + i; 1634 if (sym->st_shndx == SHN_FBSD_CACHED) { 1635 sym->st_shndx = SHN_UNDEF; 1636 sym->st_value = 0; 1637 } 1638 } 1639 } 1640 1641 /* 1642 * Symbol lookup function that can be used when the symbol index is known (ie 1643 * in relocations). It uses the symbol index instead of doing a fully fledged 1644 * hash table based lookup when such is valid. For example for local symbols. 1645 * This is not only more efficient, it's also more correct. It's not always 1646 * the case that the symbol can be found through the hash table. 1647 */ 1648 static int 1649 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1650 { 1651 elf_file_t ef = (elf_file_t)lf; 1652 Elf_Sym *sym; 1653 const char *symbol; 1654 Elf_Addr res1; 1655 1656 /* Don't even try to lookup the symbol if the index is bogus. */ 1657 if (symidx >= ef->ddbsymcnt) { 1658 *res = 0; 1659 return (EINVAL); 1660 } 1661 1662 sym = ef->ddbsymtab + symidx; 1663 1664 /* Quick answer if there is a definition included. */ 1665 if (sym->st_shndx != SHN_UNDEF) { 1666 res1 = (Elf_Addr)sym->st_value; 1667 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC) 1668 res1 = ((Elf_Addr (*)(void))res1)(); 1669 *res = res1; 1670 return (0); 1671 } 1672 1673 /* If we get here, then it is undefined and needs a lookup. */ 1674 switch (ELF_ST_BIND(sym->st_info)) { 1675 case STB_LOCAL: 1676 /* Local, but undefined? huh? */ 1677 *res = 0; 1678 return (EINVAL); 1679 1680 case STB_GLOBAL: 1681 case STB_WEAK: 1682 /* Relative to Data or Function name */ 1683 symbol = ef->ddbstrtab + sym->st_name; 1684 1685 /* Force a lookup failure if the symbol name is bogus. */ 1686 if (*symbol == 0) { 1687 *res = 0; 1688 return (EINVAL); 1689 } 1690 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1691 1692 /* 1693 * Cache global lookups during module relocation. The failure 1694 * case is particularly expensive for callers, who must scan 1695 * through the entire globals table doing strcmp(). Cache to 1696 * avoid doing such work repeatedly. 1697 * 1698 * After relocation is complete, undefined globals will be 1699 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1700 * above. 1701 */ 1702 if (res1 != 0) { 1703 sym->st_shndx = SHN_FBSD_CACHED; 1704 sym->st_value = res1; 1705 *res = res1; 1706 return (0); 1707 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1708 sym->st_value = 0; 1709 *res = 0; 1710 return (0); 1711 } 1712 return (EINVAL); 1713 1714 default: 1715 return (EINVAL); 1716 } 1717 } 1718 1719 static void 1720 link_elf_fix_link_set(elf_file_t ef) 1721 { 1722 static const char startn[] = "__start_"; 1723 static const char stopn[] = "__stop_"; 1724 Elf_Sym *sym; 1725 const char *sym_name, *linkset_name; 1726 Elf_Addr startp, stopp; 1727 Elf_Size symidx; 1728 int start, i; 1729 1730 startp = stopp = 0; 1731 for (symidx = 1 /* zero entry is special */; 1732 symidx < ef->ddbsymcnt; symidx++) { 1733 sym = ef->ddbsymtab + symidx; 1734 if (sym->st_shndx != SHN_UNDEF) 1735 continue; 1736 1737 sym_name = ef->ddbstrtab + sym->st_name; 1738 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1739 start = 1; 1740 linkset_name = sym_name + sizeof(startn) - 1; 1741 } 1742 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1743 start = 0; 1744 linkset_name = sym_name + sizeof(stopn) - 1; 1745 } 1746 else 1747 continue; 1748 1749 for (i = 0; i < ef->nprogtab; i++) { 1750 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1751 startp = (Elf_Addr)ef->progtab[i].addr; 1752 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1753 break; 1754 } 1755 } 1756 if (i == ef->nprogtab) 1757 continue; 1758 1759 sym->st_value = start ? startp : stopp; 1760 sym->st_shndx = i; 1761 } 1762 } 1763 1764 static int 1765 link_elf_reloc_local(linker_file_t lf, bool ifuncs) 1766 { 1767 elf_file_t ef = (elf_file_t)lf; 1768 const Elf_Rel *rellim; 1769 const Elf_Rel *rel; 1770 const Elf_Rela *relalim; 1771 const Elf_Rela *rela; 1772 const Elf_Sym *sym; 1773 Elf_Addr base; 1774 int i; 1775 Elf_Size symidx; 1776 1777 link_elf_fix_link_set(ef); 1778 1779 /* Perform relocations without addend if there are any: */ 1780 for (i = 0; i < ef->nreltab; i++) { 1781 rel = ef->reltab[i].rel; 1782 if (rel == NULL) { 1783 link_elf_error(ef->lf.filename, "lost a reltab"); 1784 return (ENOEXEC); 1785 } 1786 rellim = rel + ef->reltab[i].nrel; 1787 base = findbase(ef, ef->reltab[i].sec); 1788 if (base == 0) { 1789 link_elf_error(ef->lf.filename, "lost base for reltab"); 1790 return (ENOEXEC); 1791 } 1792 for ( ; rel < rellim; rel++) { 1793 symidx = ELF_R_SYM(rel->r_info); 1794 if (symidx >= ef->ddbsymcnt) 1795 continue; 1796 sym = ef->ddbsymtab + symidx; 1797 /* Only do local relocs */ 1798 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1799 continue; 1800 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1801 elf_is_ifunc_reloc(rel->r_info)) != ifuncs) 1802 continue; 1803 if (elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1804 elf_obj_lookup) != 0) 1805 return (ENOEXEC); 1806 } 1807 } 1808 1809 /* Perform relocations with addend if there are any: */ 1810 for (i = 0; i < ef->nrelatab; i++) { 1811 rela = ef->relatab[i].rela; 1812 if (rela == NULL) { 1813 link_elf_error(ef->lf.filename, "lost a relatab!"); 1814 return (ENOEXEC); 1815 } 1816 relalim = rela + ef->relatab[i].nrela; 1817 base = findbase(ef, ef->relatab[i].sec); 1818 if (base == 0) { 1819 link_elf_error(ef->lf.filename, "lost base for reltab"); 1820 return (ENOEXEC); 1821 } 1822 for ( ; rela < relalim; rela++) { 1823 symidx = ELF_R_SYM(rela->r_info); 1824 if (symidx >= ef->ddbsymcnt) 1825 continue; 1826 sym = ef->ddbsymtab + symidx; 1827 /* Only do local relocs */ 1828 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1829 continue; 1830 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1831 elf_is_ifunc_reloc(rela->r_info)) != ifuncs) 1832 continue; 1833 if (elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1834 elf_obj_lookup) != 0) 1835 return (ENOEXEC); 1836 } 1837 } 1838 return (0); 1839 } 1840 1841 static long 1842 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1843 { 1844 elf_file_t ef = (elf_file_t)lf; 1845 1846 *symtab = ef->ddbsymtab; 1847 if (*symtab == NULL) 1848 return (0); 1849 return (ef->ddbsymcnt); 1850 } 1851 1852 static long 1853 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1854 { 1855 elf_file_t ef = (elf_file_t)lf; 1856 1857 *strtab = ef->ddbstrtab; 1858 if (*strtab == NULL) 1859 return (0); 1860 return (ef->ddbstrcnt); 1861 } 1862