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 "opt_ddb.h" 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/fcntl.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/linker.h> 39 #include <sys/mutex.h> 40 #include <sys/mount.h> 41 #include <sys/namei.h> 42 #include <sys/proc.h> 43 #include <sys/rwlock.h> 44 #include <sys/sysctl.h> 45 #include <sys/vnode.h> 46 47 #include <machine/elf.h> 48 49 #include <net/vnet.h> 50 51 #include <security/mac/mac_framework.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_param.h> 55 #include <vm/pmap.h> 56 #include <vm/vm_extern.h> 57 #include <vm/vm_kern.h> 58 #include <vm/vm_map.h> 59 #include <vm/vm_object.h> 60 #include <vm/vm_page.h> 61 #include <vm/vm_pager.h> 62 63 #include <sys/link_elf.h> 64 65 #ifdef DDB_CTF 66 #include <contrib/zlib/zlib.h> 67 #endif 68 69 #include "linker_if.h" 70 71 typedef struct { 72 void *addr; 73 Elf_Off size; 74 int flags; /* Section flags. */ 75 int sec; /* Original section number. */ 76 char *name; 77 } Elf_progent; 78 79 typedef struct { 80 Elf_Rel *rel; 81 int nrel; 82 int sec; 83 } Elf_relent; 84 85 typedef struct { 86 Elf_Rela *rela; 87 int nrela; 88 int sec; 89 } Elf_relaent; 90 91 typedef struct elf_file { 92 struct linker_file lf; /* Common fields */ 93 94 int preloaded; 95 caddr_t address; /* Relocation address */ 96 vm_object_t object; /* VM object to hold file pages */ 97 Elf_Shdr *e_shdr; 98 99 Elf_progent *progtab; 100 u_int nprogtab; 101 102 Elf_relaent *relatab; 103 u_int nrelatab; 104 105 Elf_relent *reltab; 106 int nreltab; 107 108 Elf_Sym *ddbsymtab; /* The symbol table we are using */ 109 long ddbsymcnt; /* Number of symbols */ 110 caddr_t ddbstrtab; /* String table */ 111 long ddbstrcnt; /* number of bytes in string table */ 112 113 caddr_t shstrtab; /* Section name string table */ 114 long shstrcnt; /* number of bytes in string table */ 115 116 caddr_t ctftab; /* CTF table */ 117 long ctfcnt; /* number of bytes in CTF table */ 118 caddr_t ctfoff; /* CTF offset table */ 119 caddr_t typoff; /* Type offset table */ 120 long typlen; /* Number of type entries. */ 121 122 } *elf_file_t; 123 124 #include <kern/kern_ctf.c> 125 126 static int link_elf_link_preload(linker_class_t cls, 127 const char *, linker_file_t *); 128 static int link_elf_link_preload_finish(linker_file_t); 129 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); 130 static int link_elf_lookup_symbol(linker_file_t, const char *, 131 c_linker_sym_t *); 132 static int link_elf_lookup_debug_symbol(linker_file_t, const char *, 133 c_linker_sym_t *); 134 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 135 linker_symval_t *); 136 static int link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t, 137 linker_symval_t *); 138 static int link_elf_search_symbol(linker_file_t, caddr_t value, 139 c_linker_sym_t *sym, long *diffp); 140 141 static void link_elf_unload_file(linker_file_t); 142 static int link_elf_lookup_set(linker_file_t, const char *, 143 void ***, void ***, int *); 144 static int link_elf_each_function_name(linker_file_t, 145 int (*)(const char *, void *), void *); 146 static int link_elf_each_function_nameval(linker_file_t, 147 linker_function_nameval_callback_t, 148 void *); 149 static int link_elf_reloc_local(linker_file_t, bool); 150 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 151 static long link_elf_strtab_get(linker_file_t, caddr_t *); 152 #ifdef VIMAGE 153 static void link_elf_propagate_vnets(linker_file_t); 154 #endif 155 156 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, 157 Elf_Addr *); 158 159 static kobj_method_t link_elf_methods[] = { 160 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 161 KOBJMETHOD(linker_lookup_debug_symbol, link_elf_lookup_debug_symbol), 162 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 163 KOBJMETHOD(linker_debug_symbol_values, link_elf_debug_symbol_values), 164 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 165 KOBJMETHOD(linker_unload, link_elf_unload_file), 166 KOBJMETHOD(linker_load_file, link_elf_load_file), 167 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 168 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 169 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 170 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 171 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 172 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 173 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 174 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 175 #ifdef VIMAGE 176 KOBJMETHOD(linker_propagate_vnets, link_elf_propagate_vnets), 177 #endif 178 KOBJMETHOD_END 179 }; 180 181 static struct linker_class link_elf_class = { 182 #if ELF_TARG_CLASS == ELFCLASS32 183 "elf32_obj", 184 #else 185 "elf64_obj", 186 #endif 187 link_elf_methods, sizeof(struct elf_file) 188 }; 189 190 static bool link_elf_obj_leak_locals = true; 191 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_obj_leak_locals, 192 CTLFLAG_RWTUN, &link_elf_obj_leak_locals, 0, 193 "Allow local symbols to participate in global module symbol resolution"); 194 195 static int relocate_file(elf_file_t ef); 196 static void elf_obj_cleanup_globals_cache(elf_file_t); 197 198 static void 199 link_elf_error(const char *filename, const char *s) 200 { 201 if (filename == NULL) 202 printf("kldload: %s\n", s); 203 else 204 printf("kldload: %s: %s\n", filename, s); 205 } 206 207 static void 208 link_elf_init(void *arg) 209 { 210 211 linker_add_class(&link_elf_class); 212 } 213 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL); 214 215 static void 216 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end, 217 vm_prot_t prot) 218 { 219 int error __unused; 220 221 KASSERT(start <= end && start >= (vm_offset_t)ef->address && 222 end <= round_page((vm_offset_t)ef->address + ef->lf.size), 223 ("link_elf_protect_range: invalid range %#jx-%#jx", 224 (uintmax_t)start, (uintmax_t)end)); 225 226 if (start == end) 227 return; 228 if (ef->preloaded) { 229 #ifdef __amd64__ 230 error = pmap_change_prot(start, end - start, prot); 231 KASSERT(error == 0, 232 ("link_elf_protect_range: pmap_change_prot() returned %d", 233 error)); 234 #endif 235 return; 236 } 237 error = vm_map_protect(kernel_map, start, end, prot, 0, 238 VM_MAP_PROTECT_SET_PROT); 239 KASSERT(error == KERN_SUCCESS, 240 ("link_elf_protect_range: vm_map_protect() returned %d", error)); 241 } 242 243 /* 244 * Restrict permissions on linker file memory based on section flags. 245 * Sections need not be page-aligned, so overlap within a page is possible. 246 */ 247 static void 248 link_elf_protect(elf_file_t ef) 249 { 250 vm_offset_t end, segend, segstart, start; 251 vm_prot_t gapprot, prot, segprot; 252 int i; 253 254 /* 255 * If the file was preloaded, the last page may contain other preloaded 256 * data which may need to be writeable. ELF files are always 257 * page-aligned, but other preloaded data, such as entropy or CPU 258 * microcode may be loaded with a smaller alignment. 259 */ 260 gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ; 261 262 start = end = (vm_offset_t)ef->address; 263 prot = VM_PROT_READ; 264 for (i = 0; i < ef->nprogtab; i++) { 265 /* 266 * VNET and DPCPU sections have their memory allocated by their 267 * respective subsystems. 268 */ 269 if (ef->progtab[i].name != NULL && ( 270 #ifdef VIMAGE 271 strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 || 272 #endif 273 strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0)) 274 continue; 275 276 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr); 277 segend = round_page((vm_offset_t)ef->progtab[i].addr + 278 ef->progtab[i].size); 279 segprot = VM_PROT_READ; 280 if ((ef->progtab[i].flags & SHF_WRITE) != 0) 281 segprot |= VM_PROT_WRITE; 282 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0) 283 segprot |= VM_PROT_EXECUTE; 284 285 if (end <= segstart) { 286 /* 287 * Case 1: there is no overlap between the previous 288 * segment and this one. Apply protections to the 289 * previous segment, and protect the gap between the 290 * previous and current segments, if any. 291 */ 292 link_elf_protect_range(ef, start, end, prot); 293 link_elf_protect_range(ef, end, segstart, gapprot); 294 295 start = segstart; 296 end = segend; 297 prot = segprot; 298 } else if (start < segstart && end == segend) { 299 /* 300 * Case 2: the current segment is a subrange of the 301 * previous segment. Apply protections to the 302 * non-overlapping portion of the previous segment. 303 */ 304 link_elf_protect_range(ef, start, segstart, prot); 305 306 start = segstart; 307 prot |= segprot; 308 } else if (end < segend) { 309 /* 310 * Case 3: there is partial overlap between the previous 311 * and current segments. Apply protections to the 312 * non-overlapping portion of the previous segment, and 313 * then the overlap, which must use the union of the two 314 * segments' protections. 315 */ 316 link_elf_protect_range(ef, start, segstart, prot); 317 link_elf_protect_range(ef, segstart, end, 318 prot | segprot); 319 start = end; 320 end = segend; 321 prot = segprot; 322 } else { 323 /* 324 * Case 4: the two segments reside in the same page. 325 */ 326 prot |= segprot; 327 } 328 } 329 330 /* 331 * Fix up the last unprotected segment and trailing data. 332 */ 333 link_elf_protect_range(ef, start, end, prot); 334 link_elf_protect_range(ef, end, 335 round_page((vm_offset_t)ef->address + ef->lf.size), gapprot); 336 } 337 338 static int 339 link_elf_link_preload(linker_class_t cls, const char *filename, 340 linker_file_t *result) 341 { 342 Elf_Ehdr *hdr; 343 Elf_Shdr *shdr; 344 Elf_Sym *es; 345 void *modptr, *baseptr, *sizeptr; 346 char *type; 347 elf_file_t ef; 348 linker_file_t lf; 349 Elf_Addr off; 350 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 351 352 /* Look to see if we have the file preloaded */ 353 modptr = preload_search_by_name(filename); 354 if (modptr == NULL) 355 return ENOENT; 356 357 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 358 baseptr = preload_search_info(modptr, MODINFO_ADDR); 359 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 360 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 361 MODINFOMD_ELFHDR); 362 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 363 MODINFOMD_SHDR); 364 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) 365 " obj module") != 0 && 366 strcmp(type, "elf obj module") != 0)) { 367 return (EFTYPE); 368 } 369 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 370 shdr == NULL) 371 return (EINVAL); 372 373 lf = linker_make_file(filename, &link_elf_class); 374 if (lf == NULL) 375 return (ENOMEM); 376 377 ef = (elf_file_t)lf; 378 ef->preloaded = 1; 379 ef->address = *(caddr_t *)baseptr; 380 lf->address = *(caddr_t *)baseptr; 381 lf->size = *(size_t *)sizeptr; 382 383 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 384 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 385 hdr->e_ident[EI_VERSION] != EV_CURRENT || 386 hdr->e_version != EV_CURRENT || 387 hdr->e_type != ET_REL || 388 hdr->e_machine != ELF_TARG_MACH) { 389 error = EFTYPE; 390 goto out; 391 } 392 ef->e_shdr = shdr; 393 394 /* Scan the section header for information and table sizing. */ 395 symtabindex = -1; 396 symstrindex = -1; 397 for (i = 0; i < hdr->e_shnum; i++) { 398 switch (shdr[i].sh_type) { 399 case SHT_PROGBITS: 400 case SHT_NOBITS: 401 #ifdef __amd64__ 402 case SHT_X86_64_UNWIND: 403 #endif 404 case SHT_INIT_ARRAY: 405 case SHT_FINI_ARRAY: 406 /* Ignore sections not loaded by the loader. */ 407 if (shdr[i].sh_addr == 0) 408 break; 409 ef->nprogtab++; 410 break; 411 case SHT_SYMTAB: 412 symtabindex = i; 413 symstrindex = shdr[i].sh_link; 414 break; 415 case SHT_REL: 416 /* 417 * Ignore relocation tables for sections not 418 * loaded by the loader. 419 */ 420 if (shdr[shdr[i].sh_info].sh_addr == 0) 421 break; 422 ef->nreltab++; 423 break; 424 case SHT_RELA: 425 if (shdr[shdr[i].sh_info].sh_addr == 0) 426 break; 427 ef->nrelatab++; 428 break; 429 } 430 } 431 432 shstrindex = hdr->e_shstrndx; 433 if (ef->nprogtab == 0 || symstrindex < 0 || 434 symstrindex >= hdr->e_shnum || 435 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 436 shstrindex >= hdr->e_shnum || 437 shdr[shstrindex].sh_type != SHT_STRTAB) { 438 printf("%s: bad/missing section headers\n", filename); 439 error = ENOEXEC; 440 goto out; 441 } 442 443 /* Allocate space for tracking the load chunks */ 444 if (ef->nprogtab != 0) 445 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 446 M_LINKER, M_WAITOK | M_ZERO); 447 if (ef->nreltab != 0) 448 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 449 M_LINKER, M_WAITOK | M_ZERO); 450 if (ef->nrelatab != 0) 451 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 452 M_LINKER, M_WAITOK | M_ZERO); 453 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 454 (ef->nreltab != 0 && ef->reltab == NULL) || 455 (ef->nrelatab != 0 && ef->relatab == NULL)) { 456 error = ENOMEM; 457 goto out; 458 } 459 460 /* XXX, relocate the sh_addr fields saved by the loader. */ 461 off = 0; 462 for (i = 0; i < hdr->e_shnum; i++) { 463 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 464 off = shdr[i].sh_addr; 465 } 466 for (i = 0; i < hdr->e_shnum; i++) { 467 if (shdr[i].sh_addr != 0) 468 shdr[i].sh_addr = shdr[i].sh_addr - off + 469 (Elf_Addr)ef->address; 470 } 471 472 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 473 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 474 ef->ddbstrcnt = shdr[symstrindex].sh_size; 475 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 476 ef->shstrcnt = shdr[shstrindex].sh_size; 477 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 478 479 /* Now fill out progtab and the relocation tables. */ 480 pb = 0; 481 rl = 0; 482 ra = 0; 483 for (i = 0; i < hdr->e_shnum; i++) { 484 switch (shdr[i].sh_type) { 485 case SHT_PROGBITS: 486 case SHT_NOBITS: 487 #ifdef __amd64__ 488 case SHT_X86_64_UNWIND: 489 #endif 490 case SHT_INIT_ARRAY: 491 case SHT_FINI_ARRAY: 492 if (shdr[i].sh_addr == 0) 493 break; 494 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 495 if (shdr[i].sh_type == SHT_PROGBITS) 496 ef->progtab[pb].name = "<<PROGBITS>>"; 497 #ifdef __amd64__ 498 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 499 ef->progtab[pb].name = "<<UNWIND>>"; 500 #endif 501 else if (shdr[i].sh_type == SHT_INIT_ARRAY) 502 ef->progtab[pb].name = "<<INIT_ARRAY>>"; 503 else if (shdr[i].sh_type == SHT_FINI_ARRAY) 504 ef->progtab[pb].name = "<<FINI_ARRAY>>"; 505 else 506 ef->progtab[pb].name = "<<NOBITS>>"; 507 ef->progtab[pb].size = shdr[i].sh_size; 508 ef->progtab[pb].flags = shdr[i].sh_flags; 509 ef->progtab[pb].sec = i; 510 if (ef->shstrtab && shdr[i].sh_name != 0) 511 ef->progtab[pb].name = 512 ef->shstrtab + shdr[i].sh_name; 513 if (ef->progtab[pb].name != NULL && 514 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 515 void *dpcpu; 516 517 dpcpu = dpcpu_alloc(shdr[i].sh_size); 518 if (dpcpu == NULL) { 519 printf("%s: pcpu module space is out " 520 "of space; cannot allocate %#jx " 521 "for %s\n", __func__, 522 (uintmax_t)shdr[i].sh_size, 523 filename); 524 error = ENOSPC; 525 goto out; 526 } 527 memcpy(dpcpu, ef->progtab[pb].addr, 528 ef->progtab[pb].size); 529 dpcpu_copy(dpcpu, shdr[i].sh_size); 530 ef->progtab[pb].addr = dpcpu; 531 #ifdef VIMAGE 532 } else if (ef->progtab[pb].name != NULL && 533 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 534 void *vnet_data; 535 536 vnet_data = vnet_data_alloc(shdr[i].sh_size); 537 if (vnet_data == NULL) { 538 printf("%s: vnet module space is out " 539 "of space; cannot allocate %#jx " 540 "for %s\n", __func__, 541 (uintmax_t)shdr[i].sh_size, 542 filename); 543 error = ENOSPC; 544 goto out; 545 } 546 memcpy(vnet_data, ef->progtab[pb].addr, 547 ef->progtab[pb].size); 548 ef->progtab[pb].addr = vnet_data; 549 vnet_save_init(ef->progtab[pb].addr, 550 ef->progtab[pb].size); 551 #endif 552 } else if ((ef->progtab[pb].name != NULL && 553 strcmp(ef->progtab[pb].name, ".ctors") == 0) || 554 shdr[i].sh_type == SHT_INIT_ARRAY) { 555 if (lf->ctors_addr != 0) { 556 printf( 557 "%s: multiple ctor sections in %s\n", 558 __func__, filename); 559 } else { 560 lf->ctors_addr = ef->progtab[pb].addr; 561 lf->ctors_size = shdr[i].sh_size; 562 } 563 } else if ((ef->progtab[pb].name != NULL && 564 strcmp(ef->progtab[pb].name, ".dtors") == 0) || 565 shdr[i].sh_type == SHT_FINI_ARRAY) { 566 if (lf->dtors_addr != 0) { 567 printf( 568 "%s: multiple dtor sections in %s\n", 569 __func__, filename); 570 } else { 571 lf->dtors_addr = ef->progtab[pb].addr; 572 lf->dtors_size = shdr[i].sh_size; 573 } 574 } 575 576 /* Update all symbol values with the offset. */ 577 for (j = 0; j < ef->ddbsymcnt; j++) { 578 es = &ef->ddbsymtab[j]; 579 if (es->st_shndx != i) 580 continue; 581 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 582 } 583 pb++; 584 break; 585 case SHT_REL: 586 if (shdr[shdr[i].sh_info].sh_addr == 0) 587 break; 588 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 589 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 590 ef->reltab[rl].sec = shdr[i].sh_info; 591 rl++; 592 break; 593 case SHT_RELA: 594 if (shdr[shdr[i].sh_info].sh_addr == 0) 595 break; 596 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 597 ef->relatab[ra].nrela = 598 shdr[i].sh_size / sizeof(Elf_Rela); 599 ef->relatab[ra].sec = shdr[i].sh_info; 600 ra++; 601 break; 602 } 603 } 604 if (pb != ef->nprogtab) { 605 printf("%s: lost progbits\n", filename); 606 error = ENOEXEC; 607 goto out; 608 } 609 if (rl != ef->nreltab) { 610 printf("%s: lost reltab\n", filename); 611 error = ENOEXEC; 612 goto out; 613 } 614 if (ra != ef->nrelatab) { 615 printf("%s: lost relatab\n", filename); 616 error = ENOEXEC; 617 goto out; 618 } 619 620 /* 621 * The file needs to be writeable and executable while applying 622 * relocations. Mapping protections are applied once relocation 623 * processing is complete. 624 */ 625 link_elf_protect_range(ef, (vm_offset_t)ef->address, 626 round_page((vm_offset_t)ef->address + ef->lf.size), VM_PROT_ALL); 627 628 /* Local intra-module relocations */ 629 error = link_elf_reloc_local(lf, false); 630 if (error != 0) 631 goto out; 632 *result = lf; 633 return (0); 634 635 out: 636 /* preload not done this way */ 637 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 638 return (error); 639 } 640 641 static void 642 link_elf_invoke_cbs(caddr_t addr, size_t size) 643 { 644 void (**ctor)(void); 645 size_t i, cnt; 646 647 if (addr == NULL || size == 0) 648 return; 649 cnt = size / sizeof(*ctor); 650 ctor = (void *)addr; 651 for (i = 0; i < cnt; i++) { 652 if (ctor[i] != NULL) 653 (*ctor[i])(); 654 } 655 } 656 657 static int 658 link_elf_link_preload_finish(linker_file_t lf) 659 { 660 elf_file_t ef; 661 int error; 662 663 ef = (elf_file_t)lf; 664 error = relocate_file(ef); 665 if (error) 666 return (error); 667 668 /* Notify MD code that a module is being loaded. */ 669 error = elf_cpu_load_file(lf); 670 if (error) 671 return (error); 672 673 #if defined(__i386__) || defined(__amd64__) 674 /* Now ifuncs. */ 675 error = link_elf_reloc_local(lf, true); 676 if (error != 0) 677 return (error); 678 #endif 679 680 /* Apply protections now that relocation processing is complete. */ 681 link_elf_protect(ef); 682 683 link_elf_invoke_cbs(lf->ctors_addr, lf->ctors_size); 684 return (0); 685 } 686 687 static int 688 link_elf_load_file(linker_class_t cls, const char *filename, 689 linker_file_t *result) 690 { 691 struct nameidata *nd; 692 struct thread *td = curthread; /* XXX */ 693 Elf_Ehdr *hdr; 694 Elf_Shdr *shdr; 695 Elf_Sym *es; 696 int nbytes, i, j; 697 vm_offset_t mapbase; 698 size_t mapsize; 699 int error = 0; 700 ssize_t resid; 701 int flags; 702 elf_file_t ef; 703 linker_file_t lf; 704 int symtabindex; 705 int symstrindex; 706 int shstrindex; 707 int nsym; 708 int pb, rl, ra; 709 int alignmask; 710 711 shdr = NULL; 712 lf = NULL; 713 mapsize = 0; 714 hdr = NULL; 715 716 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 717 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename); 718 flags = FREAD; 719 error = vn_open(nd, &flags, 0, NULL); 720 if (error) { 721 free(nd, M_TEMP); 722 return error; 723 } 724 NDFREE_PNBUF(nd); 725 if (nd->ni_vp->v_type != VREG) { 726 error = ENOEXEC; 727 goto out; 728 } 729 #ifdef MAC 730 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 731 if (error) { 732 goto out; 733 } 734 #endif 735 736 /* Read the elf header from the file. */ 737 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 738 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 739 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 740 &resid, td); 741 if (error) 742 goto out; 743 if (resid != 0){ 744 error = ENOEXEC; 745 goto out; 746 } 747 748 if (!IS_ELF(*hdr)) { 749 error = ENOEXEC; 750 goto out; 751 } 752 753 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 754 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 755 link_elf_error(filename, "Unsupported file layout"); 756 error = ENOEXEC; 757 goto out; 758 } 759 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 760 || hdr->e_version != EV_CURRENT) { 761 link_elf_error(filename, "Unsupported file version"); 762 error = ENOEXEC; 763 goto out; 764 } 765 if (hdr->e_type != ET_REL) { 766 error = ENOSYS; 767 goto out; 768 } 769 if (hdr->e_machine != ELF_TARG_MACH) { 770 link_elf_error(filename, "Unsupported machine"); 771 error = ENOEXEC; 772 goto out; 773 } 774 775 lf = linker_make_file(filename, &link_elf_class); 776 if (!lf) { 777 error = ENOMEM; 778 goto out; 779 } 780 ef = (elf_file_t) lf; 781 ef->nprogtab = 0; 782 ef->e_shdr = 0; 783 ef->nreltab = 0; 784 ef->nrelatab = 0; 785 786 /* Allocate and read in the section header */ 787 nbytes = hdr->e_shnum * hdr->e_shentsize; 788 if (nbytes == 0 || hdr->e_shoff == 0 || 789 hdr->e_shentsize != sizeof(Elf_Shdr)) { 790 error = ENOEXEC; 791 goto out; 792 } 793 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 794 ef->e_shdr = shdr; 795 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 796 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 797 NOCRED, &resid, td); 798 if (error) 799 goto out; 800 if (resid) { 801 error = ENOEXEC; 802 goto out; 803 } 804 805 /* Scan the section header for information and table sizing. */ 806 nsym = 0; 807 symtabindex = -1; 808 symstrindex = -1; 809 for (i = 0; i < hdr->e_shnum; i++) { 810 if (shdr[i].sh_size == 0) 811 continue; 812 switch (shdr[i].sh_type) { 813 case SHT_PROGBITS: 814 case SHT_NOBITS: 815 #ifdef __amd64__ 816 case SHT_X86_64_UNWIND: 817 #endif 818 case SHT_INIT_ARRAY: 819 case SHT_FINI_ARRAY: 820 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 821 break; 822 ef->nprogtab++; 823 break; 824 case SHT_SYMTAB: 825 nsym++; 826 symtabindex = i; 827 symstrindex = shdr[i].sh_link; 828 break; 829 case SHT_REL: 830 /* 831 * Ignore relocation tables for unallocated 832 * sections. 833 */ 834 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 835 break; 836 ef->nreltab++; 837 break; 838 case SHT_RELA: 839 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 840 break; 841 ef->nrelatab++; 842 break; 843 case SHT_STRTAB: 844 break; 845 } 846 } 847 if (ef->nprogtab == 0) { 848 link_elf_error(filename, "file has no contents"); 849 error = ENOEXEC; 850 goto out; 851 } 852 if (nsym != 1) { 853 /* Only allow one symbol table for now */ 854 link_elf_error(filename, 855 "file must have exactly one symbol table"); 856 error = ENOEXEC; 857 goto out; 858 } 859 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 860 shdr[symstrindex].sh_type != SHT_STRTAB) { 861 link_elf_error(filename, "file has invalid symbol strings"); 862 error = ENOEXEC; 863 goto out; 864 } 865 866 /* Allocate space for tracking the load chunks */ 867 if (ef->nprogtab != 0) 868 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 869 M_LINKER, M_WAITOK | M_ZERO); 870 if (ef->nreltab != 0) 871 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 872 M_LINKER, M_WAITOK | M_ZERO); 873 if (ef->nrelatab != 0) 874 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 875 M_LINKER, M_WAITOK | M_ZERO); 876 877 if (symtabindex == -1) { 878 link_elf_error(filename, "lost symbol table index"); 879 error = ENOEXEC; 880 goto out; 881 } 882 /* Allocate space for and load the symbol table */ 883 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 884 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 885 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 886 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 887 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 888 &resid, td); 889 if (error) 890 goto out; 891 if (resid != 0){ 892 error = EINVAL; 893 goto out; 894 } 895 896 /* Allocate space for and load the symbol strings */ 897 ef->ddbstrcnt = shdr[symstrindex].sh_size; 898 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 899 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 900 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 901 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 902 &resid, td); 903 if (error) 904 goto out; 905 if (resid != 0){ 906 error = EINVAL; 907 goto out; 908 } 909 910 /* Do we have a string table for the section names? */ 911 shstrindex = -1; 912 if (hdr->e_shstrndx != 0 && 913 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 914 shstrindex = hdr->e_shstrndx; 915 ef->shstrcnt = shdr[shstrindex].sh_size; 916 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 917 M_WAITOK); 918 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 919 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 920 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 921 &resid, td); 922 if (error) 923 goto out; 924 if (resid != 0){ 925 error = EINVAL; 926 goto out; 927 } 928 } 929 930 /* Size up code/data(progbits) and bss(nobits). */ 931 alignmask = 0; 932 for (i = 0; i < hdr->e_shnum; i++) { 933 if (shdr[i].sh_size == 0) 934 continue; 935 switch (shdr[i].sh_type) { 936 case SHT_PROGBITS: 937 case SHT_NOBITS: 938 #ifdef __amd64__ 939 case SHT_X86_64_UNWIND: 940 #endif 941 case SHT_INIT_ARRAY: 942 case SHT_FINI_ARRAY: 943 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 944 break; 945 alignmask = shdr[i].sh_addralign - 1; 946 mapsize += alignmask; 947 mapsize &= ~alignmask; 948 mapsize += shdr[i].sh_size; 949 break; 950 } 951 } 952 953 /* 954 * We know how much space we need for the text/data/bss/etc. 955 * This stuff needs to be in a single chunk so that profiling etc 956 * can get the bounds and gdb can associate offsets with modules 957 */ 958 ef->object = vm_pager_allocate(OBJT_PHYS, NULL, round_page(mapsize), 959 VM_PROT_ALL, 0, thread0.td_ucred); 960 if (ef->object == NULL) { 961 error = ENOMEM; 962 goto out; 963 } 964 #if VM_NRESERVLEVEL > 0 965 vm_object_color(ef->object, 0); 966 #endif 967 968 /* 969 * In order to satisfy amd64's architectural requirements on the 970 * location of code and data in the kernel's address space, request a 971 * mapping that is above the kernel. 972 * 973 * Protections will be restricted once relocations are applied. 974 */ 975 #ifdef __amd64__ 976 mapbase = KERNBASE; 977 #else 978 mapbase = VM_MIN_KERNEL_ADDRESS; 979 #endif 980 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 981 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 982 VM_PROT_ALL, 0); 983 if (error != KERN_SUCCESS) { 984 vm_object_deallocate(ef->object); 985 ef->object = NULL; 986 error = ENOMEM; 987 goto out; 988 } 989 990 /* Wire the pages */ 991 error = vm_map_wire(kernel_map, mapbase, 992 mapbase + round_page(mapsize), 993 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 994 if (error != KERN_SUCCESS) { 995 error = ENOMEM; 996 goto out; 997 } 998 999 /* Inform the kld system about the situation */ 1000 lf->address = ef->address = (caddr_t)mapbase; 1001 lf->size = mapsize; 1002 1003 /* 1004 * Now load code/data(progbits), zero bss(nobits), allocate space for 1005 * and load relocs 1006 */ 1007 pb = 0; 1008 rl = 0; 1009 ra = 0; 1010 alignmask = 0; 1011 for (i = 0; i < hdr->e_shnum; i++) { 1012 if (shdr[i].sh_size == 0) 1013 continue; 1014 switch (shdr[i].sh_type) { 1015 case SHT_PROGBITS: 1016 case SHT_NOBITS: 1017 #ifdef __amd64__ 1018 case SHT_X86_64_UNWIND: 1019 #endif 1020 case SHT_INIT_ARRAY: 1021 case SHT_FINI_ARRAY: 1022 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 1023 break; 1024 alignmask = shdr[i].sh_addralign - 1; 1025 mapbase += alignmask; 1026 mapbase &= ~alignmask; 1027 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 1028 ef->progtab[pb].name = 1029 ef->shstrtab + shdr[i].sh_name; 1030 if (!strcmp(ef->progtab[pb].name, ".ctors") || 1031 shdr[i].sh_type == SHT_INIT_ARRAY) { 1032 if (lf->ctors_addr != 0) { 1033 printf( 1034 "%s: multiple ctor sections in %s\n", 1035 __func__, filename); 1036 } else { 1037 lf->ctors_addr = 1038 (caddr_t)mapbase; 1039 lf->ctors_size = 1040 shdr[i].sh_size; 1041 } 1042 } else if (!strcmp(ef->progtab[pb].name, 1043 ".dtors") || 1044 shdr[i].sh_type == SHT_FINI_ARRAY) { 1045 if (lf->dtors_addr != 0) { 1046 printf( 1047 "%s: multiple dtor sections in %s\n", 1048 __func__, filename); 1049 } else { 1050 lf->dtors_addr = 1051 (caddr_t)mapbase; 1052 lf->dtors_size = 1053 shdr[i].sh_size; 1054 } 1055 } 1056 } else if (shdr[i].sh_type == SHT_PROGBITS) 1057 ef->progtab[pb].name = "<<PROGBITS>>"; 1058 #ifdef __amd64__ 1059 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 1060 ef->progtab[pb].name = "<<UNWIND>>"; 1061 #endif 1062 else 1063 ef->progtab[pb].name = "<<NOBITS>>"; 1064 if (ef->progtab[pb].name != NULL && 1065 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 1066 ef->progtab[pb].addr = 1067 dpcpu_alloc(shdr[i].sh_size); 1068 if (ef->progtab[pb].addr == NULL) { 1069 printf("%s: pcpu module space is out " 1070 "of space; cannot allocate %#jx " 1071 "for %s\n", __func__, 1072 (uintmax_t)shdr[i].sh_size, 1073 filename); 1074 } 1075 } 1076 #ifdef VIMAGE 1077 else if (ef->progtab[pb].name != NULL && 1078 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 1079 ef->progtab[pb].addr = 1080 vnet_data_alloc(shdr[i].sh_size); 1081 if (ef->progtab[pb].addr == NULL) { 1082 printf("%s: vnet module space is out " 1083 "of space; cannot allocate %#jx " 1084 "for %s\n", __func__, 1085 (uintmax_t)shdr[i].sh_size, 1086 filename); 1087 } 1088 } 1089 #endif 1090 else 1091 ef->progtab[pb].addr = 1092 (void *)(uintptr_t)mapbase; 1093 if (ef->progtab[pb].addr == NULL) { 1094 error = ENOSPC; 1095 goto out; 1096 } 1097 ef->progtab[pb].size = shdr[i].sh_size; 1098 ef->progtab[pb].flags = shdr[i].sh_flags; 1099 ef->progtab[pb].sec = i; 1100 if (shdr[i].sh_type == SHT_PROGBITS 1101 #ifdef __amd64__ 1102 || shdr[i].sh_type == SHT_X86_64_UNWIND 1103 #endif 1104 ) { 1105 error = vn_rdwr(UIO_READ, nd->ni_vp, 1106 ef->progtab[pb].addr, 1107 shdr[i].sh_size, shdr[i].sh_offset, 1108 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 1109 NOCRED, &resid, td); 1110 if (error) 1111 goto out; 1112 if (resid != 0){ 1113 error = EINVAL; 1114 goto out; 1115 } 1116 /* Initialize the per-cpu area. */ 1117 if (ef->progtab[pb].addr != (void *)mapbase && 1118 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 1119 dpcpu_copy(ef->progtab[pb].addr, 1120 shdr[i].sh_size); 1121 } else 1122 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 1123 1124 #ifdef VIMAGE 1125 if (ef->progtab[pb].addr != (void *)mapbase && 1126 strcmp(ef->progtab[pb].name, VNET_SETNAME) == 0) 1127 vnet_save_init(ef->progtab[pb].addr, 1128 ef->progtab[pb].size); 1129 #endif 1130 /* Update all symbol values with the offset. */ 1131 for (j = 0; j < ef->ddbsymcnt; j++) { 1132 es = &ef->ddbsymtab[j]; 1133 if (es->st_shndx != i) 1134 continue; 1135 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 1136 } 1137 mapbase += shdr[i].sh_size; 1138 pb++; 1139 break; 1140 case SHT_REL: 1141 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 1142 break; 1143 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 1144 M_WAITOK); 1145 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 1146 ef->reltab[rl].sec = shdr[i].sh_info; 1147 error = vn_rdwr(UIO_READ, nd->ni_vp, 1148 (void *)ef->reltab[rl].rel, 1149 shdr[i].sh_size, shdr[i].sh_offset, 1150 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1151 &resid, td); 1152 if (error) 1153 goto out; 1154 if (resid != 0){ 1155 error = EINVAL; 1156 goto out; 1157 } 1158 rl++; 1159 break; 1160 case SHT_RELA: 1161 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 1162 break; 1163 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 1164 M_WAITOK); 1165 ef->relatab[ra].nrela = 1166 shdr[i].sh_size / sizeof(Elf_Rela); 1167 ef->relatab[ra].sec = shdr[i].sh_info; 1168 error = vn_rdwr(UIO_READ, nd->ni_vp, 1169 (void *)ef->relatab[ra].rela, 1170 shdr[i].sh_size, shdr[i].sh_offset, 1171 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1172 &resid, td); 1173 if (error) 1174 goto out; 1175 if (resid != 0){ 1176 error = EINVAL; 1177 goto out; 1178 } 1179 ra++; 1180 break; 1181 } 1182 } 1183 if (pb != ef->nprogtab) { 1184 link_elf_error(filename, "lost progbits"); 1185 error = ENOEXEC; 1186 goto out; 1187 } 1188 if (rl != ef->nreltab) { 1189 link_elf_error(filename, "lost reltab"); 1190 error = ENOEXEC; 1191 goto out; 1192 } 1193 if (ra != ef->nrelatab) { 1194 link_elf_error(filename, "lost relatab"); 1195 error = ENOEXEC; 1196 goto out; 1197 } 1198 if (mapbase != (vm_offset_t)ef->address + mapsize) { 1199 printf( 1200 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 1201 filename != NULL ? filename : "<none>", 1202 (u_long)mapbase, ef->address, (u_long)mapsize, 1203 (u_long)(vm_offset_t)ef->address + mapsize); 1204 error = ENOMEM; 1205 goto out; 1206 } 1207 1208 /* Local intra-module relocations */ 1209 error = link_elf_reloc_local(lf, false); 1210 if (error != 0) 1211 goto out; 1212 1213 /* Pull in dependencies */ 1214 VOP_UNLOCK(nd->ni_vp); 1215 error = linker_load_dependencies(lf); 1216 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 1217 if (error) 1218 goto out; 1219 1220 /* External relocations */ 1221 error = relocate_file(ef); 1222 if (error) 1223 goto out; 1224 1225 /* Notify MD code that a module is being loaded. */ 1226 error = elf_cpu_load_file(lf); 1227 if (error) 1228 goto out; 1229 1230 #if defined(__i386__) || defined(__amd64__) 1231 /* Now ifuncs. */ 1232 error = link_elf_reloc_local(lf, true); 1233 if (error != 0) 1234 goto out; 1235 #endif 1236 1237 link_elf_protect(ef); 1238 link_elf_invoke_cbs(lf->ctors_addr, lf->ctors_size); 1239 *result = lf; 1240 1241 out: 1242 VOP_UNLOCK(nd->ni_vp); 1243 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 1244 free(nd, M_TEMP); 1245 if (error && lf) 1246 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1247 free(hdr, M_LINKER); 1248 1249 return error; 1250 } 1251 1252 static void 1253 link_elf_unload_file(linker_file_t file) 1254 { 1255 elf_file_t ef = (elf_file_t) file; 1256 u_int i; 1257 1258 link_elf_invoke_cbs(file->dtors_addr, file->dtors_size); 1259 1260 /* Notify MD code that a module is being unloaded. */ 1261 elf_cpu_unload_file(file); 1262 1263 if (ef->progtab) { 1264 for (i = 0; i < ef->nprogtab; i++) { 1265 if (ef->progtab[i].size == 0) 1266 continue; 1267 if (ef->progtab[i].name == NULL) 1268 continue; 1269 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 1270 dpcpu_free(ef->progtab[i].addr, 1271 ef->progtab[i].size); 1272 #ifdef VIMAGE 1273 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 1274 vnet_data_free(ef->progtab[i].addr, 1275 ef->progtab[i].size); 1276 #endif 1277 } 1278 } 1279 if (ef->preloaded) { 1280 free(ef->reltab, M_LINKER); 1281 free(ef->relatab, M_LINKER); 1282 free(ef->progtab, M_LINKER); 1283 free(ef->ctftab, M_LINKER); 1284 free(ef->ctfoff, M_LINKER); 1285 free(ef->typoff, M_LINKER); 1286 if (file->pathname != NULL) 1287 preload_delete_name(file->pathname); 1288 return; 1289 } 1290 1291 for (i = 0; i < ef->nreltab; i++) 1292 free(ef->reltab[i].rel, M_LINKER); 1293 for (i = 0; i < ef->nrelatab; i++) 1294 free(ef->relatab[i].rela, M_LINKER); 1295 free(ef->reltab, M_LINKER); 1296 free(ef->relatab, M_LINKER); 1297 free(ef->progtab, M_LINKER); 1298 1299 if (ef->object != NULL) 1300 vm_map_remove(kernel_map, (vm_offset_t)ef->address, 1301 (vm_offset_t)ef->address + ptoa(ef->object->size)); 1302 free(ef->e_shdr, M_LINKER); 1303 free(ef->ddbsymtab, M_LINKER); 1304 free(ef->ddbstrtab, M_LINKER); 1305 free(ef->shstrtab, M_LINKER); 1306 free(ef->ctftab, M_LINKER); 1307 free(ef->ctfoff, M_LINKER); 1308 free(ef->typoff, M_LINKER); 1309 } 1310 1311 static const char * 1312 symbol_name(elf_file_t ef, Elf_Size r_info) 1313 { 1314 const Elf_Sym *ref; 1315 1316 if (ELF_R_SYM(r_info)) { 1317 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1318 return ef->ddbstrtab + ref->st_name; 1319 } else 1320 return NULL; 1321 } 1322 1323 static Elf_Addr 1324 findbase(elf_file_t ef, int sec) 1325 { 1326 int i; 1327 Elf_Addr base = 0; 1328 1329 for (i = 0; i < ef->nprogtab; i++) { 1330 if (sec == ef->progtab[i].sec) { 1331 base = (Elf_Addr)ef->progtab[i].addr; 1332 break; 1333 } 1334 } 1335 return base; 1336 } 1337 1338 static int 1339 relocate_file1(elf_file_t ef, bool ifuncs) 1340 { 1341 const Elf_Rel *rellim; 1342 const Elf_Rel *rel; 1343 const Elf_Rela *relalim; 1344 const Elf_Rela *rela; 1345 const char *symname; 1346 const Elf_Sym *sym; 1347 int i; 1348 Elf_Size symidx; 1349 Elf_Addr base; 1350 1351 /* Perform relocations without addend if there are any: */ 1352 for (i = 0; i < ef->nreltab; i++) { 1353 rel = ef->reltab[i].rel; 1354 if (rel == NULL) { 1355 link_elf_error(ef->lf.filename, "lost a reltab!"); 1356 return (ENOEXEC); 1357 } 1358 rellim = rel + ef->reltab[i].nrel; 1359 base = findbase(ef, ef->reltab[i].sec); 1360 if (base == 0) { 1361 link_elf_error(ef->lf.filename, "lost base for reltab"); 1362 return (ENOEXEC); 1363 } 1364 for ( ; rel < rellim; rel++) { 1365 symidx = ELF_R_SYM(rel->r_info); 1366 if (symidx >= ef->ddbsymcnt) 1367 continue; 1368 sym = ef->ddbsymtab + symidx; 1369 /* Local relocs are already done */ 1370 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1371 continue; 1372 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1373 elf_is_ifunc_reloc(rel->r_info)) != ifuncs) 1374 continue; 1375 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1376 elf_obj_lookup)) { 1377 symname = symbol_name(ef, rel->r_info); 1378 printf("link_elf_obj: symbol %s undefined\n", 1379 symname); 1380 return (ENOENT); 1381 } 1382 } 1383 } 1384 1385 /* Perform relocations with addend if there are any: */ 1386 for (i = 0; i < ef->nrelatab; i++) { 1387 rela = ef->relatab[i].rela; 1388 if (rela == NULL) { 1389 link_elf_error(ef->lf.filename, "lost a relatab!"); 1390 return (ENOEXEC); 1391 } 1392 relalim = rela + ef->relatab[i].nrela; 1393 base = findbase(ef, ef->relatab[i].sec); 1394 if (base == 0) { 1395 link_elf_error(ef->lf.filename, 1396 "lost base for relatab"); 1397 return (ENOEXEC); 1398 } 1399 for ( ; rela < relalim; rela++) { 1400 symidx = ELF_R_SYM(rela->r_info); 1401 if (symidx >= ef->ddbsymcnt) 1402 continue; 1403 sym = ef->ddbsymtab + symidx; 1404 /* Local relocs are already done */ 1405 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1406 continue; 1407 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1408 elf_is_ifunc_reloc(rela->r_info)) != ifuncs) 1409 continue; 1410 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1411 elf_obj_lookup)) { 1412 symname = symbol_name(ef, rela->r_info); 1413 printf("link_elf_obj: symbol %s undefined\n", 1414 symname); 1415 return (ENOENT); 1416 } 1417 } 1418 } 1419 1420 /* 1421 * Only clean SHN_FBSD_CACHED for successful return. If we 1422 * modified symbol table for the object but found an 1423 * unresolved symbol, there is no reason to roll back. 1424 */ 1425 elf_obj_cleanup_globals_cache(ef); 1426 1427 return (0); 1428 } 1429 1430 static int 1431 relocate_file(elf_file_t ef) 1432 { 1433 int error; 1434 1435 error = relocate_file1(ef, false); 1436 if (error == 0) 1437 error = relocate_file1(ef, true); 1438 return (error); 1439 } 1440 1441 static int 1442 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym, 1443 bool see_local) 1444 { 1445 elf_file_t ef = (elf_file_t)lf; 1446 const Elf_Sym *symp; 1447 const char *strp; 1448 int i; 1449 1450 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1451 strp = ef->ddbstrtab + symp->st_name; 1452 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1453 if (see_local || 1454 ELF_ST_BIND(symp->st_info) == STB_GLOBAL) { 1455 *sym = (c_linker_sym_t) symp; 1456 return (0); 1457 } 1458 return (ENOENT); 1459 } 1460 } 1461 return (ENOENT); 1462 } 1463 1464 static int 1465 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1466 { 1467 return (link_elf_lookup_symbol1(lf, name, sym, 1468 link_elf_obj_leak_locals)); 1469 } 1470 1471 static int 1472 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name, 1473 c_linker_sym_t *sym) 1474 { 1475 return (link_elf_lookup_symbol1(lf, name, sym, true)); 1476 } 1477 1478 static int 1479 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym, 1480 linker_symval_t *symval, bool see_local) 1481 { 1482 elf_file_t ef; 1483 const Elf_Sym *es; 1484 caddr_t val; 1485 1486 ef = (elf_file_t) lf; 1487 es = (const Elf_Sym*) sym; 1488 val = (caddr_t)es->st_value; 1489 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1490 if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL) 1491 return (ENOENT); 1492 symval->name = ef->ddbstrtab + es->st_name; 1493 val = (caddr_t)es->st_value; 1494 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1495 val = ((caddr_t (*)(void))val)(); 1496 symval->value = val; 1497 symval->size = es->st_size; 1498 return (0); 1499 } 1500 return (ENOENT); 1501 } 1502 1503 static int 1504 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1505 linker_symval_t *symval) 1506 { 1507 return (link_elf_symbol_values1(lf, sym, symval, 1508 link_elf_obj_leak_locals)); 1509 } 1510 1511 static int 1512 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1513 linker_symval_t *symval) 1514 { 1515 return (link_elf_symbol_values1(lf, sym, symval, true)); 1516 } 1517 1518 static int 1519 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1520 c_linker_sym_t *sym, long *diffp) 1521 { 1522 elf_file_t ef = (elf_file_t)lf; 1523 u_long off = (uintptr_t)(void *)value; 1524 u_long diff = off; 1525 u_long st_value; 1526 const Elf_Sym *es; 1527 const Elf_Sym *best = NULL; 1528 int i; 1529 1530 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1531 if (es->st_name == 0) 1532 continue; 1533 st_value = es->st_value; 1534 if (off >= st_value) { 1535 if (off - st_value < diff) { 1536 diff = off - st_value; 1537 best = es; 1538 if (diff == 0) 1539 break; 1540 } else if (off - st_value == diff) { 1541 best = es; 1542 } 1543 } 1544 } 1545 if (best == NULL) 1546 *diffp = off; 1547 else 1548 *diffp = diff; 1549 *sym = (c_linker_sym_t) best; 1550 1551 return (0); 1552 } 1553 1554 /* 1555 * Look up a linker set on an ELF system. 1556 */ 1557 static int 1558 link_elf_lookup_set(linker_file_t lf, const char *name, 1559 void ***startp, void ***stopp, int *countp) 1560 { 1561 elf_file_t ef = (elf_file_t)lf; 1562 void **start, **stop; 1563 int i, count; 1564 1565 /* Relative to section number */ 1566 for (i = 0; i < ef->nprogtab; i++) { 1567 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1568 strcmp(ef->progtab[i].name + 4, name) == 0) { 1569 start = (void **)ef->progtab[i].addr; 1570 stop = (void **)((char *)ef->progtab[i].addr + 1571 ef->progtab[i].size); 1572 count = stop - start; 1573 if (startp) 1574 *startp = start; 1575 if (stopp) 1576 *stopp = stop; 1577 if (countp) 1578 *countp = count; 1579 return (0); 1580 } 1581 } 1582 return (ESRCH); 1583 } 1584 1585 static int 1586 link_elf_each_function_name(linker_file_t file, 1587 int (*callback)(const char *, void *), void *opaque) 1588 { 1589 elf_file_t ef = (elf_file_t)file; 1590 const Elf_Sym *symp; 1591 int i, error; 1592 1593 /* Exhaustive search */ 1594 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1595 if (symp->st_value != 0 && 1596 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1597 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1598 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1599 if (error) 1600 return (error); 1601 } 1602 } 1603 return (0); 1604 } 1605 1606 static int 1607 link_elf_each_function_nameval(linker_file_t file, 1608 linker_function_nameval_callback_t callback, void *opaque) 1609 { 1610 linker_symval_t symval; 1611 elf_file_t ef = (elf_file_t)file; 1612 const Elf_Sym *symp; 1613 int i, error; 1614 1615 /* Exhaustive search */ 1616 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1617 if (symp->st_value != 0 && 1618 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1619 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1620 error = link_elf_debug_symbol_values(file, 1621 (c_linker_sym_t)symp, &symval); 1622 if (error == 0) 1623 error = callback(file, i, &symval, opaque); 1624 if (error != 0) 1625 return (error); 1626 } 1627 } 1628 return (0); 1629 } 1630 1631 static void 1632 elf_obj_cleanup_globals_cache(elf_file_t ef) 1633 { 1634 Elf_Sym *sym; 1635 Elf_Size i; 1636 1637 for (i = 0; i < ef->ddbsymcnt; i++) { 1638 sym = ef->ddbsymtab + i; 1639 if (sym->st_shndx == SHN_FBSD_CACHED) { 1640 sym->st_shndx = SHN_UNDEF; 1641 sym->st_value = 0; 1642 } 1643 } 1644 } 1645 1646 /* 1647 * Symbol lookup function that can be used when the symbol index is known (ie 1648 * in relocations). It uses the symbol index instead of doing a fully fledged 1649 * hash table based lookup when such is valid. For example for local symbols. 1650 * This is not only more efficient, it's also more correct. It's not always 1651 * the case that the symbol can be found through the hash table. 1652 */ 1653 static int 1654 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1655 { 1656 elf_file_t ef = (elf_file_t)lf; 1657 Elf_Sym *sym; 1658 const char *symbol; 1659 Elf_Addr res1; 1660 1661 /* Don't even try to lookup the symbol if the index is bogus. */ 1662 if (symidx >= ef->ddbsymcnt) { 1663 *res = 0; 1664 return (EINVAL); 1665 } 1666 1667 sym = ef->ddbsymtab + symidx; 1668 1669 /* Quick answer if there is a definition included. */ 1670 if (sym->st_shndx != SHN_UNDEF) { 1671 res1 = (Elf_Addr)sym->st_value; 1672 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC) 1673 res1 = ((Elf_Addr (*)(void))res1)(); 1674 *res = res1; 1675 return (0); 1676 } 1677 1678 /* If we get here, then it is undefined and needs a lookup. */ 1679 switch (ELF_ST_BIND(sym->st_info)) { 1680 case STB_LOCAL: 1681 /* Local, but undefined? huh? */ 1682 *res = 0; 1683 return (EINVAL); 1684 1685 case STB_GLOBAL: 1686 case STB_WEAK: 1687 /* Relative to Data or Function name */ 1688 symbol = ef->ddbstrtab + sym->st_name; 1689 1690 /* Force a lookup failure if the symbol name is bogus. */ 1691 if (*symbol == 0) { 1692 *res = 0; 1693 return (EINVAL); 1694 } 1695 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1696 1697 /* 1698 * Cache global lookups during module relocation. The failure 1699 * case is particularly expensive for callers, who must scan 1700 * through the entire globals table doing strcmp(). Cache to 1701 * avoid doing such work repeatedly. 1702 * 1703 * After relocation is complete, undefined globals will be 1704 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1705 * above. 1706 */ 1707 if (res1 != 0) { 1708 sym->st_shndx = SHN_FBSD_CACHED; 1709 sym->st_value = res1; 1710 *res = res1; 1711 return (0); 1712 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1713 sym->st_value = 0; 1714 *res = 0; 1715 return (0); 1716 } 1717 return (EINVAL); 1718 1719 default: 1720 return (EINVAL); 1721 } 1722 } 1723 1724 static void 1725 link_elf_fix_link_set(elf_file_t ef) 1726 { 1727 static const char startn[] = "__start_"; 1728 static const char stopn[] = "__stop_"; 1729 Elf_Sym *sym; 1730 const char *sym_name, *linkset_name; 1731 Elf_Addr startp, stopp; 1732 Elf_Size symidx; 1733 int start, i; 1734 1735 startp = stopp = 0; 1736 for (symidx = 1 /* zero entry is special */; 1737 symidx < ef->ddbsymcnt; symidx++) { 1738 sym = ef->ddbsymtab + symidx; 1739 if (sym->st_shndx != SHN_UNDEF) 1740 continue; 1741 1742 sym_name = ef->ddbstrtab + sym->st_name; 1743 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1744 start = 1; 1745 linkset_name = sym_name + sizeof(startn) - 1; 1746 } 1747 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1748 start = 0; 1749 linkset_name = sym_name + sizeof(stopn) - 1; 1750 } 1751 else 1752 continue; 1753 1754 for (i = 0; i < ef->nprogtab; i++) { 1755 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1756 startp = (Elf_Addr)ef->progtab[i].addr; 1757 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1758 break; 1759 } 1760 } 1761 if (i == ef->nprogtab) 1762 continue; 1763 1764 sym->st_value = start ? startp : stopp; 1765 sym->st_shndx = i; 1766 } 1767 } 1768 1769 static int 1770 link_elf_reloc_local(linker_file_t lf, bool ifuncs) 1771 { 1772 elf_file_t ef = (elf_file_t)lf; 1773 const Elf_Rel *rellim; 1774 const Elf_Rel *rel; 1775 const Elf_Rela *relalim; 1776 const Elf_Rela *rela; 1777 const Elf_Sym *sym; 1778 Elf_Addr base; 1779 int i; 1780 Elf_Size symidx; 1781 1782 link_elf_fix_link_set(ef); 1783 1784 /* Perform relocations without addend if there are any: */ 1785 for (i = 0; i < ef->nreltab; i++) { 1786 rel = ef->reltab[i].rel; 1787 if (rel == NULL) { 1788 link_elf_error(ef->lf.filename, "lost a reltab"); 1789 return (ENOEXEC); 1790 } 1791 rellim = rel + ef->reltab[i].nrel; 1792 base = findbase(ef, ef->reltab[i].sec); 1793 if (base == 0) { 1794 link_elf_error(ef->lf.filename, "lost base for reltab"); 1795 return (ENOEXEC); 1796 } 1797 for ( ; rel < rellim; rel++) { 1798 symidx = ELF_R_SYM(rel->r_info); 1799 if (symidx >= ef->ddbsymcnt) 1800 continue; 1801 sym = ef->ddbsymtab + symidx; 1802 /* Only do local relocs */ 1803 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1804 continue; 1805 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1806 elf_is_ifunc_reloc(rel->r_info)) != ifuncs) 1807 continue; 1808 if (elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1809 elf_obj_lookup) != 0) 1810 return (ENOEXEC); 1811 } 1812 } 1813 1814 /* Perform relocations with addend if there are any: */ 1815 for (i = 0; i < ef->nrelatab; i++) { 1816 rela = ef->relatab[i].rela; 1817 if (rela == NULL) { 1818 link_elf_error(ef->lf.filename, "lost a relatab!"); 1819 return (ENOEXEC); 1820 } 1821 relalim = rela + ef->relatab[i].nrela; 1822 base = findbase(ef, ef->relatab[i].sec); 1823 if (base == 0) { 1824 link_elf_error(ef->lf.filename, "lost base for reltab"); 1825 return (ENOEXEC); 1826 } 1827 for ( ; rela < relalim; rela++) { 1828 symidx = ELF_R_SYM(rela->r_info); 1829 if (symidx >= ef->ddbsymcnt) 1830 continue; 1831 sym = ef->ddbsymtab + symidx; 1832 /* Only do local relocs */ 1833 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1834 continue; 1835 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1836 elf_is_ifunc_reloc(rela->r_info)) != ifuncs) 1837 continue; 1838 if (elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1839 elf_obj_lookup) != 0) 1840 return (ENOEXEC); 1841 } 1842 } 1843 return (0); 1844 } 1845 1846 static long 1847 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1848 { 1849 elf_file_t ef = (elf_file_t)lf; 1850 1851 *symtab = ef->ddbsymtab; 1852 if (*symtab == NULL) 1853 return (0); 1854 return (ef->ddbsymcnt); 1855 } 1856 1857 static long 1858 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1859 { 1860 elf_file_t ef = (elf_file_t)lf; 1861 1862 *strtab = ef->ddbstrtab; 1863 if (*strtab == NULL) 1864 return (0); 1865 return (ef->ddbstrcnt); 1866 } 1867 1868 #ifdef VIMAGE 1869 static void 1870 link_elf_propagate_vnets(linker_file_t lf) 1871 { 1872 elf_file_t ef = (elf_file_t) lf; 1873 1874 if (ef->progtab) { 1875 for (int i = 0; i < ef->nprogtab; i++) { 1876 if (ef->progtab[i].size == 0) 1877 continue; 1878 if (ef->progtab[i].name == NULL) 1879 continue; 1880 if (strcmp(ef->progtab[i].name, VNET_SETNAME) == 0) { 1881 vnet_data_copy(ef->progtab[i].addr, 1882 ef->progtab[i].size); 1883 break; 1884 } 1885 } 1886 } 1887 } 1888 #endif 1889