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_lookup_debug_symbol_ctf(linker_file_t lf, 135 const char *name, c_linker_sym_t *sym, linker_ctf_t *lc); 136 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 137 linker_symval_t *); 138 static int link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t, 139 linker_symval_t *); 140 static int link_elf_search_symbol(linker_file_t, caddr_t value, 141 c_linker_sym_t *sym, long *diffp); 142 143 static void link_elf_unload_file(linker_file_t); 144 static int link_elf_lookup_set(linker_file_t, const char *, 145 void ***, void ***, int *); 146 static int link_elf_each_function_name(linker_file_t, 147 int (*)(const char *, void *), void *); 148 static int link_elf_each_function_nameval(linker_file_t, 149 linker_function_nameval_callback_t, 150 void *); 151 static int link_elf_reloc_local(linker_file_t, bool); 152 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 153 static long link_elf_strtab_get(linker_file_t, caddr_t *); 154 #ifdef VIMAGE 155 static void link_elf_propagate_vnets(linker_file_t); 156 #endif 157 158 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, 159 Elf_Addr *); 160 161 static kobj_method_t link_elf_methods[] = { 162 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 163 KOBJMETHOD(linker_lookup_debug_symbol, link_elf_lookup_debug_symbol), 164 KOBJMETHOD(linker_lookup_debug_symbol_ctf, link_elf_lookup_debug_symbol_ctf), 165 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 166 KOBJMETHOD(linker_debug_symbol_values, link_elf_debug_symbol_values), 167 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 168 KOBJMETHOD(linker_unload, link_elf_unload_file), 169 KOBJMETHOD(linker_load_file, link_elf_load_file), 170 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 171 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 172 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 173 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 174 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 175 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 176 KOBJMETHOD(linker_ctf_lookup_typename, link_elf_ctf_lookup_typename), 177 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 178 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 179 #ifdef VIMAGE 180 KOBJMETHOD(linker_propagate_vnets, link_elf_propagate_vnets), 181 #endif 182 KOBJMETHOD_END 183 }; 184 185 static struct linker_class link_elf_class = { 186 #if ELF_TARG_CLASS == ELFCLASS32 187 "elf32_obj", 188 #else 189 "elf64_obj", 190 #endif 191 link_elf_methods, sizeof(struct elf_file) 192 }; 193 194 static bool link_elf_obj_leak_locals = true; 195 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_obj_leak_locals, 196 CTLFLAG_RWTUN, &link_elf_obj_leak_locals, 0, 197 "Allow local symbols to participate in global module symbol resolution"); 198 199 static int relocate_file(elf_file_t ef); 200 static void elf_obj_cleanup_globals_cache(elf_file_t); 201 202 static void 203 link_elf_error(const char *filename, const char *s) 204 { 205 if (filename == NULL) 206 printf("kldload: %s\n", s); 207 else 208 printf("kldload: %s: %s\n", filename, s); 209 } 210 211 static void 212 link_elf_init(void *arg) 213 { 214 215 linker_add_class(&link_elf_class); 216 } 217 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, NULL); 218 219 static void 220 link_elf_protect_range(elf_file_t ef, vm_offset_t start, vm_offset_t end, 221 vm_prot_t prot) 222 { 223 int error __unused; 224 225 KASSERT(start <= end && start >= (vm_offset_t)ef->address && 226 end <= round_page((vm_offset_t)ef->address + ef->lf.size), 227 ("link_elf_protect_range: invalid range %#jx-%#jx", 228 (uintmax_t)start, (uintmax_t)end)); 229 230 if (start == end) 231 return; 232 if (ef->preloaded) { 233 #ifdef __amd64__ 234 error = pmap_change_prot(start, end - start, prot); 235 KASSERT(error == 0, 236 ("link_elf_protect_range: pmap_change_prot() returned %d", 237 error)); 238 #endif 239 return; 240 } 241 error = vm_map_protect(kernel_map, start, end, prot, 0, 242 VM_MAP_PROTECT_SET_PROT); 243 KASSERT(error == KERN_SUCCESS, 244 ("link_elf_protect_range: vm_map_protect() returned %d", error)); 245 } 246 247 /* 248 * Restrict permissions on linker file memory based on section flags. 249 * Sections need not be page-aligned, so overlap within a page is possible. 250 */ 251 static void 252 link_elf_protect(elf_file_t ef) 253 { 254 vm_offset_t end, segend, segstart, start; 255 vm_prot_t gapprot, prot, segprot; 256 int i; 257 258 /* 259 * If the file was preloaded, the last page may contain other preloaded 260 * data which may need to be writeable. ELF files are always 261 * page-aligned, but other preloaded data, such as entropy or CPU 262 * microcode may be loaded with a smaller alignment. 263 */ 264 gapprot = ef->preloaded ? VM_PROT_RW : VM_PROT_READ; 265 266 start = end = (vm_offset_t)ef->address; 267 prot = VM_PROT_READ; 268 for (i = 0; i < ef->nprogtab; i++) { 269 /* 270 * VNET and DPCPU sections have their memory allocated by their 271 * respective subsystems. 272 */ 273 if (ef->progtab[i].name != NULL && ( 274 #ifdef VIMAGE 275 strcmp(ef->progtab[i].name, VNET_SETNAME) == 0 || 276 #endif 277 strcmp(ef->progtab[i].name, DPCPU_SETNAME) == 0)) 278 continue; 279 280 segstart = trunc_page((vm_offset_t)ef->progtab[i].addr); 281 segend = round_page((vm_offset_t)ef->progtab[i].addr + 282 ef->progtab[i].size); 283 segprot = VM_PROT_READ; 284 if ((ef->progtab[i].flags & SHF_WRITE) != 0) 285 segprot |= VM_PROT_WRITE; 286 if ((ef->progtab[i].flags & SHF_EXECINSTR) != 0) 287 segprot |= VM_PROT_EXECUTE; 288 289 if (end <= segstart) { 290 /* 291 * Case 1: there is no overlap between the previous 292 * segment and this one. Apply protections to the 293 * previous segment, and protect the gap between the 294 * previous and current segments, if any. 295 */ 296 link_elf_protect_range(ef, start, end, prot); 297 link_elf_protect_range(ef, end, segstart, gapprot); 298 299 start = segstart; 300 end = segend; 301 prot = segprot; 302 } else if (start < segstart && end == segend) { 303 /* 304 * Case 2: the current segment is a subrange of the 305 * previous segment. Apply protections to the 306 * non-overlapping portion of the previous segment. 307 */ 308 link_elf_protect_range(ef, start, segstart, prot); 309 310 start = segstart; 311 prot |= segprot; 312 } else if (end < segend) { 313 /* 314 * Case 3: there is partial overlap between the previous 315 * and current segments. Apply protections to the 316 * non-overlapping portion of the previous segment, and 317 * then the overlap, which must use the union of the two 318 * segments' protections. 319 */ 320 link_elf_protect_range(ef, start, segstart, prot); 321 link_elf_protect_range(ef, segstart, end, 322 prot | segprot); 323 start = end; 324 end = segend; 325 prot = segprot; 326 } else { 327 /* 328 * Case 4: the two segments reside in the same page. 329 */ 330 prot |= segprot; 331 } 332 } 333 334 /* 335 * Fix up the last unprotected segment and trailing data. 336 */ 337 link_elf_protect_range(ef, start, end, prot); 338 link_elf_protect_range(ef, end, 339 round_page((vm_offset_t)ef->address + ef->lf.size), gapprot); 340 } 341 342 static int 343 link_elf_link_preload(linker_class_t cls, const char *filename, 344 linker_file_t *result) 345 { 346 Elf_Ehdr *hdr; 347 Elf_Shdr *shdr; 348 Elf_Sym *es; 349 void *modptr, *baseptr, *sizeptr; 350 char *type; 351 elf_file_t ef; 352 linker_file_t lf; 353 Elf_Addr off; 354 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; 355 356 /* Look to see if we have the file preloaded */ 357 modptr = preload_search_by_name(filename); 358 if (modptr == NULL) 359 return ENOENT; 360 361 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 362 baseptr = preload_search_info(modptr, MODINFO_ADDR); 363 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 364 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | 365 MODINFOMD_ELFHDR); 366 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | 367 MODINFOMD_SHDR); 368 if (type == NULL || strcmp(type, preload_modtype_obj) != 0) 369 return (EFTYPE); 370 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || 371 shdr == NULL) 372 return (EINVAL); 373 374 lf = linker_make_file(filename, &link_elf_class); 375 if (lf == NULL) 376 return (ENOMEM); 377 378 ef = (elf_file_t)lf; 379 ef->preloaded = 1; 380 ef->address = *(caddr_t *)baseptr; 381 lf->address = *(caddr_t *)baseptr; 382 lf->size = *(size_t *)sizeptr; 383 384 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 385 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 386 hdr->e_ident[EI_VERSION] != EV_CURRENT || 387 hdr->e_version != EV_CURRENT || 388 hdr->e_type != ET_REL || 389 hdr->e_machine != ELF_TARG_MACH) { 390 error = EFTYPE; 391 goto out; 392 } 393 ef->e_shdr = shdr; 394 395 /* Scan the section header for information and table sizing. */ 396 symtabindex = -1; 397 symstrindex = -1; 398 for (i = 0; i < hdr->e_shnum; i++) { 399 switch (shdr[i].sh_type) { 400 case SHT_PROGBITS: 401 case SHT_NOBITS: 402 #ifdef __amd64__ 403 case SHT_X86_64_UNWIND: 404 #endif 405 case SHT_INIT_ARRAY: 406 case SHT_FINI_ARRAY: 407 /* Ignore sections not loaded by the loader. */ 408 if (shdr[i].sh_addr == 0) 409 break; 410 ef->nprogtab++; 411 break; 412 case SHT_SYMTAB: 413 symtabindex = i; 414 symstrindex = shdr[i].sh_link; 415 break; 416 case SHT_REL: 417 /* 418 * Ignore relocation tables for sections not 419 * loaded by the loader. 420 */ 421 if (shdr[shdr[i].sh_info].sh_addr == 0) 422 break; 423 ef->nreltab++; 424 break; 425 case SHT_RELA: 426 if (shdr[shdr[i].sh_info].sh_addr == 0) 427 break; 428 ef->nrelatab++; 429 break; 430 } 431 } 432 433 shstrindex = hdr->e_shstrndx; 434 if (ef->nprogtab == 0 || symstrindex < 0 || 435 symstrindex >= hdr->e_shnum || 436 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || 437 shstrindex >= hdr->e_shnum || 438 shdr[shstrindex].sh_type != SHT_STRTAB) { 439 printf("%s: bad/missing section headers\n", filename); 440 error = ENOEXEC; 441 goto out; 442 } 443 444 /* Allocate space for tracking the load chunks */ 445 if (ef->nprogtab != 0) 446 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 447 M_LINKER, M_WAITOK | M_ZERO); 448 if (ef->nreltab != 0) 449 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 450 M_LINKER, M_WAITOK | M_ZERO); 451 if (ef->nrelatab != 0) 452 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 453 M_LINKER, M_WAITOK | M_ZERO); 454 if ((ef->nprogtab != 0 && ef->progtab == NULL) || 455 (ef->nreltab != 0 && ef->reltab == NULL) || 456 (ef->nrelatab != 0 && ef->relatab == NULL)) { 457 error = ENOMEM; 458 goto out; 459 } 460 461 /* XXX, relocate the sh_addr fields saved by the loader. */ 462 off = 0; 463 for (i = 0; i < hdr->e_shnum; i++) { 464 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) 465 off = shdr[i].sh_addr; 466 } 467 for (i = 0; i < hdr->e_shnum; i++) { 468 if (shdr[i].sh_addr != 0) 469 shdr[i].sh_addr = shdr[i].sh_addr - off + 470 (Elf_Addr)ef->address; 471 } 472 473 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 474 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; 475 ef->ddbstrcnt = shdr[symstrindex].sh_size; 476 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; 477 ef->shstrcnt = shdr[shstrindex].sh_size; 478 ef->shstrtab = (char *)shdr[shstrindex].sh_addr; 479 480 /* Now fill out progtab and the relocation tables. */ 481 pb = 0; 482 rl = 0; 483 ra = 0; 484 for (i = 0; i < hdr->e_shnum; i++) { 485 switch (shdr[i].sh_type) { 486 case SHT_PROGBITS: 487 case SHT_NOBITS: 488 #ifdef __amd64__ 489 case SHT_X86_64_UNWIND: 490 #endif 491 case SHT_INIT_ARRAY: 492 case SHT_FINI_ARRAY: 493 if (shdr[i].sh_addr == 0) 494 break; 495 ef->progtab[pb].addr = (void *)shdr[i].sh_addr; 496 if (shdr[i].sh_type == SHT_PROGBITS) 497 ef->progtab[pb].name = "<<PROGBITS>>"; 498 #ifdef __amd64__ 499 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 500 ef->progtab[pb].name = "<<UNWIND>>"; 501 #endif 502 else if (shdr[i].sh_type == SHT_INIT_ARRAY) 503 ef->progtab[pb].name = "<<INIT_ARRAY>>"; 504 else if (shdr[i].sh_type == SHT_FINI_ARRAY) 505 ef->progtab[pb].name = "<<FINI_ARRAY>>"; 506 else 507 ef->progtab[pb].name = "<<NOBITS>>"; 508 ef->progtab[pb].size = shdr[i].sh_size; 509 ef->progtab[pb].flags = shdr[i].sh_flags; 510 ef->progtab[pb].sec = i; 511 if (ef->shstrtab && shdr[i].sh_name != 0) 512 ef->progtab[pb].name = 513 ef->shstrtab + shdr[i].sh_name; 514 if (ef->progtab[pb].name != NULL && 515 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 516 void *dpcpu; 517 518 dpcpu = dpcpu_alloc(shdr[i].sh_size); 519 if (dpcpu == NULL) { 520 printf("%s: pcpu module space is out " 521 "of space; cannot allocate %#jx " 522 "for %s\n", __func__, 523 (uintmax_t)shdr[i].sh_size, 524 filename); 525 error = ENOSPC; 526 goto out; 527 } 528 memcpy(dpcpu, ef->progtab[pb].addr, 529 ef->progtab[pb].size); 530 dpcpu_copy(dpcpu, shdr[i].sh_size); 531 ef->progtab[pb].addr = dpcpu; 532 #ifdef VIMAGE 533 } else if (ef->progtab[pb].name != NULL && 534 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 535 void *vnet_data; 536 537 vnet_data = vnet_data_alloc(shdr[i].sh_size); 538 if (vnet_data == NULL) { 539 printf("%s: vnet module space is out " 540 "of space; cannot allocate %#jx " 541 "for %s\n", __func__, 542 (uintmax_t)shdr[i].sh_size, 543 filename); 544 error = ENOSPC; 545 goto out; 546 } 547 memcpy(vnet_data, ef->progtab[pb].addr, 548 ef->progtab[pb].size); 549 ef->progtab[pb].addr = vnet_data; 550 vnet_save_init(ef->progtab[pb].addr, 551 ef->progtab[pb].size); 552 #endif 553 } else if ((ef->progtab[pb].name != NULL && 554 strcmp(ef->progtab[pb].name, ".ctors") == 0) || 555 shdr[i].sh_type == SHT_INIT_ARRAY) { 556 if (lf->ctors_addr != 0) { 557 printf( 558 "%s: multiple ctor sections in %s\n", 559 __func__, filename); 560 } else { 561 lf->ctors_addr = ef->progtab[pb].addr; 562 lf->ctors_size = shdr[i].sh_size; 563 } 564 } else if ((ef->progtab[pb].name != NULL && 565 strcmp(ef->progtab[pb].name, ".dtors") == 0) || 566 shdr[i].sh_type == SHT_FINI_ARRAY) { 567 if (lf->dtors_addr != 0) { 568 printf( 569 "%s: multiple dtor sections in %s\n", 570 __func__, filename); 571 } else { 572 lf->dtors_addr = ef->progtab[pb].addr; 573 lf->dtors_size = shdr[i].sh_size; 574 } 575 } 576 577 /* Update all symbol values with the offset. */ 578 for (j = 0; j < ef->ddbsymcnt; j++) { 579 es = &ef->ddbsymtab[j]; 580 if (es->st_shndx != i) 581 continue; 582 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 583 } 584 pb++; 585 break; 586 case SHT_REL: 587 if (shdr[shdr[i].sh_info].sh_addr == 0) 588 break; 589 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; 590 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 591 ef->reltab[rl].sec = shdr[i].sh_info; 592 rl++; 593 break; 594 case SHT_RELA: 595 if (shdr[shdr[i].sh_info].sh_addr == 0) 596 break; 597 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; 598 ef->relatab[ra].nrela = 599 shdr[i].sh_size / sizeof(Elf_Rela); 600 ef->relatab[ra].sec = shdr[i].sh_info; 601 ra++; 602 break; 603 } 604 } 605 if (pb != ef->nprogtab) { 606 printf("%s: lost progbits\n", filename); 607 error = ENOEXEC; 608 goto out; 609 } 610 if (rl != ef->nreltab) { 611 printf("%s: lost reltab\n", filename); 612 error = ENOEXEC; 613 goto out; 614 } 615 if (ra != ef->nrelatab) { 616 printf("%s: lost relatab\n", filename); 617 error = ENOEXEC; 618 goto out; 619 } 620 621 /* 622 * The file needs to be writeable and executable while applying 623 * relocations. Mapping protections are applied once relocation 624 * processing is complete. 625 */ 626 link_elf_protect_range(ef, (vm_offset_t)ef->address, 627 round_page((vm_offset_t)ef->address + ef->lf.size), VM_PROT_ALL); 628 629 /* Local intra-module relocations */ 630 error = link_elf_reloc_local(lf, false); 631 if (error != 0) 632 goto out; 633 *result = lf; 634 return (0); 635 636 out: 637 /* preload not done this way */ 638 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 639 return (error); 640 } 641 642 static void 643 link_elf_invoke_cbs(caddr_t addr, size_t size) 644 { 645 void (**ctor)(void); 646 size_t i, cnt; 647 648 if (addr == NULL || size == 0) 649 return; 650 cnt = size / sizeof(*ctor); 651 ctor = (void *)addr; 652 for (i = 0; i < cnt; i++) { 653 if (ctor[i] != NULL) 654 (*ctor[i])(); 655 } 656 } 657 658 static void 659 link_elf_invoke_ctors(linker_file_t lf) 660 { 661 KASSERT(lf->ctors_invoked == LF_NONE, 662 ("%s: file %s ctor state %d", 663 __func__, lf->filename, lf->ctors_invoked)); 664 665 link_elf_invoke_cbs(lf->ctors_addr, lf->ctors_size); 666 lf->ctors_invoked = LF_CTORS; 667 } 668 669 static void 670 link_elf_invoke_dtors(linker_file_t lf) 671 { 672 KASSERT(lf->ctors_invoked != LF_DTORS, 673 ("%s: file %s ctor state %d", 674 __func__, lf->filename, lf->ctors_invoked)); 675 676 if (lf->ctors_invoked == LF_CTORS) { 677 link_elf_invoke_cbs(lf->dtors_addr, lf->dtors_size); 678 lf->ctors_invoked = LF_DTORS; 679 } 680 } 681 682 static int 683 link_elf_link_preload_finish(linker_file_t lf) 684 { 685 elf_file_t ef; 686 int error; 687 688 ef = (elf_file_t)lf; 689 error = relocate_file(ef); 690 if (error) 691 return (error); 692 693 /* Notify MD code that a module is being loaded. */ 694 error = elf_cpu_load_file(lf); 695 if (error) 696 return (error); 697 698 #if defined(__i386__) || defined(__amd64__) 699 /* Now ifuncs. */ 700 error = link_elf_reloc_local(lf, true); 701 if (error != 0) 702 return (error); 703 #endif 704 705 /* Apply protections now that relocation processing is complete. */ 706 link_elf_protect(ef); 707 708 link_elf_invoke_ctors(lf); 709 return (0); 710 } 711 712 static int 713 link_elf_load_file(linker_class_t cls, const char *filename, 714 linker_file_t *result) 715 { 716 struct nameidata *nd; 717 struct thread *td = curthread; /* XXX */ 718 Elf_Ehdr *hdr; 719 Elf_Shdr *shdr; 720 Elf_Sym *es; 721 int nbytes, i, j; 722 vm_offset_t mapbase; 723 size_t mapsize; 724 int error = 0; 725 ssize_t resid; 726 int flags; 727 elf_file_t ef; 728 linker_file_t lf; 729 int symtabindex; 730 int symstrindex; 731 int shstrindex; 732 int nsym; 733 int pb, rl, ra; 734 int alignmask; 735 736 shdr = NULL; 737 lf = NULL; 738 mapsize = 0; 739 hdr = NULL; 740 741 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); 742 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename); 743 flags = FREAD; 744 error = vn_open(nd, &flags, 0, NULL); 745 if (error) { 746 free(nd, M_TEMP); 747 return error; 748 } 749 NDFREE_PNBUF(nd); 750 if (nd->ni_vp->v_type != VREG) { 751 error = ENOEXEC; 752 goto out; 753 } 754 #ifdef MAC 755 error = mac_kld_check_load(td->td_ucred, nd->ni_vp); 756 if (error) { 757 goto out; 758 } 759 #endif 760 761 /* Read the elf header from the file. */ 762 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 763 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, 764 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 765 &resid, td); 766 if (error) 767 goto out; 768 if (resid != 0){ 769 error = ENOEXEC; 770 goto out; 771 } 772 773 if (!IS_ELF(*hdr)) { 774 error = ENOEXEC; 775 goto out; 776 } 777 778 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 779 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 780 link_elf_error(filename, "Unsupported file layout"); 781 error = ENOEXEC; 782 goto out; 783 } 784 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 785 || hdr->e_version != EV_CURRENT) { 786 link_elf_error(filename, "Unsupported file version"); 787 error = ENOEXEC; 788 goto out; 789 } 790 if (hdr->e_type != ET_REL) { 791 error = ENOSYS; 792 goto out; 793 } 794 if (hdr->e_machine != ELF_TARG_MACH) { 795 link_elf_error(filename, "Unsupported machine"); 796 error = ENOEXEC; 797 goto out; 798 } 799 800 lf = linker_make_file(filename, &link_elf_class); 801 if (!lf) { 802 error = ENOMEM; 803 goto out; 804 } 805 ef = (elf_file_t) lf; 806 ef->nprogtab = 0; 807 ef->e_shdr = 0; 808 ef->nreltab = 0; 809 ef->nrelatab = 0; 810 811 /* Allocate and read in the section header */ 812 nbytes = hdr->e_shnum * hdr->e_shentsize; 813 if (nbytes == 0 || hdr->e_shoff == 0 || 814 hdr->e_shentsize != sizeof(Elf_Shdr)) { 815 error = ENOEXEC; 816 goto out; 817 } 818 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 819 ef->e_shdr = shdr; 820 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, 821 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 822 NOCRED, &resid, td); 823 if (error) 824 goto out; 825 if (resid) { 826 error = ENOEXEC; 827 goto out; 828 } 829 830 /* Scan the section header for information and table sizing. */ 831 nsym = 0; 832 symtabindex = -1; 833 symstrindex = -1; 834 for (i = 0; i < hdr->e_shnum; i++) { 835 if (shdr[i].sh_size == 0) 836 continue; 837 switch (shdr[i].sh_type) { 838 case SHT_PROGBITS: 839 case SHT_NOBITS: 840 #ifdef __amd64__ 841 case SHT_X86_64_UNWIND: 842 #endif 843 case SHT_INIT_ARRAY: 844 case SHT_FINI_ARRAY: 845 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 846 break; 847 ef->nprogtab++; 848 break; 849 case SHT_SYMTAB: 850 nsym++; 851 symtabindex = i; 852 symstrindex = shdr[i].sh_link; 853 break; 854 case SHT_REL: 855 /* 856 * Ignore relocation tables for unallocated 857 * sections. 858 */ 859 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 860 break; 861 ef->nreltab++; 862 break; 863 case SHT_RELA: 864 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 865 break; 866 ef->nrelatab++; 867 break; 868 case SHT_STRTAB: 869 break; 870 } 871 } 872 if (ef->nprogtab == 0) { 873 link_elf_error(filename, "file has no contents"); 874 error = ENOEXEC; 875 goto out; 876 } 877 if (nsym != 1) { 878 /* Only allow one symbol table for now */ 879 link_elf_error(filename, 880 "file must have exactly one symbol table"); 881 error = ENOEXEC; 882 goto out; 883 } 884 if (symstrindex < 0 || symstrindex > hdr->e_shnum || 885 shdr[symstrindex].sh_type != SHT_STRTAB) { 886 link_elf_error(filename, "file has invalid symbol strings"); 887 error = ENOEXEC; 888 goto out; 889 } 890 891 /* Allocate space for tracking the load chunks */ 892 if (ef->nprogtab != 0) 893 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), 894 M_LINKER, M_WAITOK | M_ZERO); 895 if (ef->nreltab != 0) 896 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), 897 M_LINKER, M_WAITOK | M_ZERO); 898 if (ef->nrelatab != 0) 899 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), 900 M_LINKER, M_WAITOK | M_ZERO); 901 902 if (symtabindex == -1) { 903 link_elf_error(filename, "lost symbol table index"); 904 error = ENOEXEC; 905 goto out; 906 } 907 /* Allocate space for and load the symbol table */ 908 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); 909 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); 910 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, 911 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, 912 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 913 &resid, td); 914 if (error) 915 goto out; 916 if (resid != 0){ 917 error = EINVAL; 918 goto out; 919 } 920 921 /* Allocate space for and load the symbol strings */ 922 ef->ddbstrcnt = shdr[symstrindex].sh_size; 923 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); 924 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, 925 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, 926 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 927 &resid, td); 928 if (error) 929 goto out; 930 if (resid != 0){ 931 error = EINVAL; 932 goto out; 933 } 934 935 /* Do we have a string table for the section names? */ 936 shstrindex = -1; 937 if (hdr->e_shstrndx != 0 && 938 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { 939 shstrindex = hdr->e_shstrndx; 940 ef->shstrcnt = shdr[shstrindex].sh_size; 941 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, 942 M_WAITOK); 943 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, 944 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, 945 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 946 &resid, td); 947 if (error) 948 goto out; 949 if (resid != 0){ 950 error = EINVAL; 951 goto out; 952 } 953 } 954 955 /* Size up code/data(progbits) and bss(nobits). */ 956 alignmask = 0; 957 for (i = 0; i < hdr->e_shnum; i++) { 958 if (shdr[i].sh_size == 0) 959 continue; 960 switch (shdr[i].sh_type) { 961 case SHT_PROGBITS: 962 case SHT_NOBITS: 963 #ifdef __amd64__ 964 case SHT_X86_64_UNWIND: 965 #endif 966 case SHT_INIT_ARRAY: 967 case SHT_FINI_ARRAY: 968 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 969 break; 970 alignmask = shdr[i].sh_addralign - 1; 971 mapsize += alignmask; 972 mapsize &= ~alignmask; 973 mapsize += shdr[i].sh_size; 974 break; 975 } 976 } 977 978 /* 979 * We know how much space we need for the text/data/bss/etc. 980 * This stuff needs to be in a single chunk so that profiling etc 981 * can get the bounds and gdb can associate offsets with modules 982 */ 983 ef->object = vm_pager_allocate(OBJT_PHYS, NULL, round_page(mapsize), 984 VM_PROT_ALL, 0, thread0.td_ucred); 985 if (ef->object == NULL) { 986 error = ENOMEM; 987 goto out; 988 } 989 #if VM_NRESERVLEVEL > 0 990 vm_object_color(ef->object, 0); 991 #endif 992 993 /* 994 * In order to satisfy amd64's architectural requirements on the 995 * location of code and data in the kernel's address space, request a 996 * mapping that is above the kernel. 997 * 998 * Protections will be restricted once relocations are applied. 999 */ 1000 #ifdef __amd64__ 1001 mapbase = KERNBASE; 1002 #else 1003 mapbase = VM_MIN_KERNEL_ADDRESS; 1004 #endif 1005 error = vm_map_find(kernel_map, ef->object, 0, &mapbase, 1006 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, 1007 VM_PROT_ALL, 0); 1008 if (error != KERN_SUCCESS) { 1009 vm_object_deallocate(ef->object); 1010 ef->object = NULL; 1011 error = ENOMEM; 1012 goto out; 1013 } 1014 1015 /* Wire the pages */ 1016 error = vm_map_wire(kernel_map, mapbase, 1017 mapbase + round_page(mapsize), 1018 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 1019 if (error != KERN_SUCCESS) { 1020 error = ENOMEM; 1021 goto out; 1022 } 1023 1024 /* Inform the kld system about the situation */ 1025 lf->address = ef->address = (caddr_t)mapbase; 1026 lf->size = mapsize; 1027 1028 /* 1029 * Now load code/data(progbits), zero bss(nobits), allocate space for 1030 * and load relocs 1031 */ 1032 pb = 0; 1033 rl = 0; 1034 ra = 0; 1035 alignmask = 0; 1036 for (i = 0; i < hdr->e_shnum; i++) { 1037 if (shdr[i].sh_size == 0) 1038 continue; 1039 switch (shdr[i].sh_type) { 1040 case SHT_PROGBITS: 1041 case SHT_NOBITS: 1042 #ifdef __amd64__ 1043 case SHT_X86_64_UNWIND: 1044 #endif 1045 case SHT_INIT_ARRAY: 1046 case SHT_FINI_ARRAY: 1047 if ((shdr[i].sh_flags & SHF_ALLOC) == 0) 1048 break; 1049 alignmask = shdr[i].sh_addralign - 1; 1050 mapbase += alignmask; 1051 mapbase &= ~alignmask; 1052 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { 1053 ef->progtab[pb].name = 1054 ef->shstrtab + shdr[i].sh_name; 1055 if (!strcmp(ef->progtab[pb].name, ".ctors") || 1056 shdr[i].sh_type == SHT_INIT_ARRAY) { 1057 if (lf->ctors_addr != 0) { 1058 printf( 1059 "%s: multiple ctor sections in %s\n", 1060 __func__, filename); 1061 } else { 1062 lf->ctors_addr = 1063 (caddr_t)mapbase; 1064 lf->ctors_size = 1065 shdr[i].sh_size; 1066 } 1067 } else if (!strcmp(ef->progtab[pb].name, 1068 ".dtors") || 1069 shdr[i].sh_type == SHT_FINI_ARRAY) { 1070 if (lf->dtors_addr != 0) { 1071 printf( 1072 "%s: multiple dtor sections in %s\n", 1073 __func__, filename); 1074 } else { 1075 lf->dtors_addr = 1076 (caddr_t)mapbase; 1077 lf->dtors_size = 1078 shdr[i].sh_size; 1079 } 1080 } 1081 } else if (shdr[i].sh_type == SHT_PROGBITS) 1082 ef->progtab[pb].name = "<<PROGBITS>>"; 1083 #ifdef __amd64__ 1084 else if (shdr[i].sh_type == SHT_X86_64_UNWIND) 1085 ef->progtab[pb].name = "<<UNWIND>>"; 1086 #endif 1087 else 1088 ef->progtab[pb].name = "<<NOBITS>>"; 1089 if (ef->progtab[pb].name != NULL && 1090 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { 1091 ef->progtab[pb].addr = 1092 dpcpu_alloc(shdr[i].sh_size); 1093 if (ef->progtab[pb].addr == NULL) { 1094 printf("%s: pcpu module space is out " 1095 "of space; cannot allocate %#jx " 1096 "for %s\n", __func__, 1097 (uintmax_t)shdr[i].sh_size, 1098 filename); 1099 } 1100 } 1101 #ifdef VIMAGE 1102 else if (ef->progtab[pb].name != NULL && 1103 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { 1104 ef->progtab[pb].addr = 1105 vnet_data_alloc(shdr[i].sh_size); 1106 if (ef->progtab[pb].addr == NULL) { 1107 printf("%s: vnet module space is out " 1108 "of space; cannot allocate %#jx " 1109 "for %s\n", __func__, 1110 (uintmax_t)shdr[i].sh_size, 1111 filename); 1112 } 1113 } 1114 #endif 1115 else 1116 ef->progtab[pb].addr = 1117 (void *)(uintptr_t)mapbase; 1118 if (ef->progtab[pb].addr == NULL) { 1119 error = ENOSPC; 1120 goto out; 1121 } 1122 ef->progtab[pb].size = shdr[i].sh_size; 1123 ef->progtab[pb].flags = shdr[i].sh_flags; 1124 ef->progtab[pb].sec = i; 1125 if (shdr[i].sh_type == SHT_PROGBITS 1126 #ifdef __amd64__ 1127 || shdr[i].sh_type == SHT_X86_64_UNWIND 1128 #endif 1129 ) { 1130 error = vn_rdwr(UIO_READ, nd->ni_vp, 1131 ef->progtab[pb].addr, 1132 shdr[i].sh_size, shdr[i].sh_offset, 1133 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 1134 NOCRED, &resid, td); 1135 if (error) 1136 goto out; 1137 if (resid != 0){ 1138 error = EINVAL; 1139 goto out; 1140 } 1141 /* Initialize the per-cpu area. */ 1142 if (ef->progtab[pb].addr != (void *)mapbase && 1143 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) 1144 dpcpu_copy(ef->progtab[pb].addr, 1145 shdr[i].sh_size); 1146 } else 1147 bzero(ef->progtab[pb].addr, shdr[i].sh_size); 1148 1149 #ifdef VIMAGE 1150 if (ef->progtab[pb].addr != (void *)mapbase && 1151 strcmp(ef->progtab[pb].name, VNET_SETNAME) == 0) 1152 vnet_save_init(ef->progtab[pb].addr, 1153 ef->progtab[pb].size); 1154 #endif 1155 /* Update all symbol values with the offset. */ 1156 for (j = 0; j < ef->ddbsymcnt; j++) { 1157 es = &ef->ddbsymtab[j]; 1158 if (es->st_shndx != i) 1159 continue; 1160 es->st_value += (Elf_Addr)ef->progtab[pb].addr; 1161 } 1162 mapbase += shdr[i].sh_size; 1163 pb++; 1164 break; 1165 case SHT_REL: 1166 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 1167 break; 1168 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, 1169 M_WAITOK); 1170 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); 1171 ef->reltab[rl].sec = shdr[i].sh_info; 1172 error = vn_rdwr(UIO_READ, nd->ni_vp, 1173 (void *)ef->reltab[rl].rel, 1174 shdr[i].sh_size, shdr[i].sh_offset, 1175 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1176 &resid, td); 1177 if (error) 1178 goto out; 1179 if (resid != 0){ 1180 error = EINVAL; 1181 goto out; 1182 } 1183 rl++; 1184 break; 1185 case SHT_RELA: 1186 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0) 1187 break; 1188 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, 1189 M_WAITOK); 1190 ef->relatab[ra].nrela = 1191 shdr[i].sh_size / sizeof(Elf_Rela); 1192 ef->relatab[ra].sec = shdr[i].sh_info; 1193 error = vn_rdwr(UIO_READ, nd->ni_vp, 1194 (void *)ef->relatab[ra].rela, 1195 shdr[i].sh_size, shdr[i].sh_offset, 1196 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1197 &resid, td); 1198 if (error) 1199 goto out; 1200 if (resid != 0){ 1201 error = EINVAL; 1202 goto out; 1203 } 1204 ra++; 1205 break; 1206 } 1207 } 1208 if (pb != ef->nprogtab) { 1209 link_elf_error(filename, "lost progbits"); 1210 error = ENOEXEC; 1211 goto out; 1212 } 1213 if (rl != ef->nreltab) { 1214 link_elf_error(filename, "lost reltab"); 1215 error = ENOEXEC; 1216 goto out; 1217 } 1218 if (ra != ef->nrelatab) { 1219 link_elf_error(filename, "lost relatab"); 1220 error = ENOEXEC; 1221 goto out; 1222 } 1223 if (mapbase != (vm_offset_t)ef->address + mapsize) { 1224 printf( 1225 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", 1226 filename != NULL ? filename : "<none>", 1227 (u_long)mapbase, ef->address, (u_long)mapsize, 1228 (u_long)(vm_offset_t)ef->address + mapsize); 1229 error = ENOMEM; 1230 goto out; 1231 } 1232 1233 /* Local intra-module relocations */ 1234 error = link_elf_reloc_local(lf, false); 1235 if (error != 0) 1236 goto out; 1237 1238 /* Pull in dependencies */ 1239 VOP_UNLOCK(nd->ni_vp); 1240 error = linker_load_dependencies(lf); 1241 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); 1242 if (error) 1243 goto out; 1244 1245 /* External relocations */ 1246 error = relocate_file(ef); 1247 if (error) 1248 goto out; 1249 1250 /* Notify MD code that a module is being loaded. */ 1251 error = elf_cpu_load_file(lf); 1252 if (error) 1253 goto out; 1254 1255 #if defined(__i386__) || defined(__amd64__) 1256 /* Now ifuncs. */ 1257 error = link_elf_reloc_local(lf, true); 1258 if (error != 0) 1259 goto out; 1260 #endif 1261 1262 link_elf_protect(ef); 1263 link_elf_invoke_ctors(lf); 1264 *result = lf; 1265 1266 out: 1267 VOP_UNLOCK(nd->ni_vp); 1268 vn_close(nd->ni_vp, FREAD, td->td_ucred, td); 1269 free(nd, M_TEMP); 1270 if (error && lf) 1271 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1272 free(hdr, M_LINKER); 1273 1274 return error; 1275 } 1276 1277 static void 1278 link_elf_unload_file(linker_file_t file) 1279 { 1280 elf_file_t ef = (elf_file_t) file; 1281 u_int i; 1282 1283 link_elf_invoke_dtors(file); 1284 1285 /* Notify MD code that a module is being unloaded. */ 1286 elf_cpu_unload_file(file); 1287 1288 if (ef->progtab) { 1289 for (i = 0; i < ef->nprogtab; i++) { 1290 if (ef->progtab[i].size == 0) 1291 continue; 1292 if (ef->progtab[i].name == NULL) 1293 continue; 1294 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) 1295 dpcpu_free(ef->progtab[i].addr, 1296 ef->progtab[i].size); 1297 #ifdef VIMAGE 1298 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) 1299 vnet_data_free(ef->progtab[i].addr, 1300 ef->progtab[i].size); 1301 #endif 1302 } 1303 } 1304 if (ef->preloaded) { 1305 free(ef->reltab, M_LINKER); 1306 free(ef->relatab, M_LINKER); 1307 free(ef->progtab, M_LINKER); 1308 free(ef->ctftab, M_LINKER); 1309 free(ef->ctfoff, M_LINKER); 1310 free(ef->typoff, M_LINKER); 1311 if (file->pathname != NULL) 1312 preload_delete_name(file->pathname); 1313 return; 1314 } 1315 1316 for (i = 0; i < ef->nreltab; i++) 1317 free(ef->reltab[i].rel, M_LINKER); 1318 for (i = 0; i < ef->nrelatab; i++) 1319 free(ef->relatab[i].rela, M_LINKER); 1320 free(ef->reltab, M_LINKER); 1321 free(ef->relatab, M_LINKER); 1322 free(ef->progtab, M_LINKER); 1323 1324 if (ef->object != NULL) 1325 vm_map_remove(kernel_map, (vm_offset_t)ef->address, 1326 (vm_offset_t)ef->address + ptoa(ef->object->size)); 1327 free(ef->e_shdr, M_LINKER); 1328 free(ef->ddbsymtab, M_LINKER); 1329 free(ef->ddbstrtab, M_LINKER); 1330 free(ef->shstrtab, M_LINKER); 1331 free(ef->ctftab, M_LINKER); 1332 free(ef->ctfoff, M_LINKER); 1333 free(ef->typoff, M_LINKER); 1334 } 1335 1336 static const char * 1337 symbol_name(elf_file_t ef, Elf_Size r_info) 1338 { 1339 const Elf_Sym *ref; 1340 1341 if (ELF_R_SYM(r_info)) { 1342 ref = ef->ddbsymtab + ELF_R_SYM(r_info); 1343 return ef->ddbstrtab + ref->st_name; 1344 } else 1345 return NULL; 1346 } 1347 1348 static Elf_Addr 1349 findbase(elf_file_t ef, int sec) 1350 { 1351 int i; 1352 Elf_Addr base = 0; 1353 1354 for (i = 0; i < ef->nprogtab; i++) { 1355 if (sec == ef->progtab[i].sec) { 1356 base = (Elf_Addr)ef->progtab[i].addr; 1357 break; 1358 } 1359 } 1360 return base; 1361 } 1362 1363 static int 1364 relocate_file1(elf_file_t ef, bool ifuncs) 1365 { 1366 const Elf_Rel *rellim; 1367 const Elf_Rel *rel; 1368 const Elf_Rela *relalim; 1369 const Elf_Rela *rela; 1370 const char *symname; 1371 const Elf_Sym *sym; 1372 int i; 1373 Elf_Size symidx; 1374 Elf_Addr base; 1375 1376 /* Perform relocations without addend if there are any: */ 1377 for (i = 0; i < ef->nreltab; i++) { 1378 rel = ef->reltab[i].rel; 1379 if (rel == NULL) { 1380 link_elf_error(ef->lf.filename, "lost a reltab!"); 1381 return (ENOEXEC); 1382 } 1383 rellim = rel + ef->reltab[i].nrel; 1384 base = findbase(ef, ef->reltab[i].sec); 1385 if (base == 0) { 1386 link_elf_error(ef->lf.filename, "lost base for reltab"); 1387 return (ENOEXEC); 1388 } 1389 for ( ; rel < rellim; rel++) { 1390 symidx = ELF_R_SYM(rel->r_info); 1391 if (symidx >= ef->ddbsymcnt) 1392 continue; 1393 sym = ef->ddbsymtab + symidx; 1394 /* Local relocs are already done */ 1395 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1396 continue; 1397 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1398 elf_is_ifunc_reloc(rel->r_info)) != ifuncs) 1399 continue; 1400 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, 1401 elf_obj_lookup)) { 1402 symname = symbol_name(ef, rel->r_info); 1403 printf("link_elf_obj: symbol %s undefined\n", 1404 symname); 1405 return (ENOENT); 1406 } 1407 } 1408 } 1409 1410 /* Perform relocations with addend if there are any: */ 1411 for (i = 0; i < ef->nrelatab; i++) { 1412 rela = ef->relatab[i].rela; 1413 if (rela == NULL) { 1414 link_elf_error(ef->lf.filename, "lost a relatab!"); 1415 return (ENOEXEC); 1416 } 1417 relalim = rela + ef->relatab[i].nrela; 1418 base = findbase(ef, ef->relatab[i].sec); 1419 if (base == 0) { 1420 link_elf_error(ef->lf.filename, 1421 "lost base for relatab"); 1422 return (ENOEXEC); 1423 } 1424 for ( ; rela < relalim; rela++) { 1425 symidx = ELF_R_SYM(rela->r_info); 1426 if (symidx >= ef->ddbsymcnt) 1427 continue; 1428 sym = ef->ddbsymtab + symidx; 1429 /* Local relocs are already done */ 1430 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) 1431 continue; 1432 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1433 elf_is_ifunc_reloc(rela->r_info)) != ifuncs) 1434 continue; 1435 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, 1436 elf_obj_lookup)) { 1437 symname = symbol_name(ef, rela->r_info); 1438 printf("link_elf_obj: symbol %s undefined\n", 1439 symname); 1440 return (ENOENT); 1441 } 1442 } 1443 } 1444 1445 /* 1446 * Only clean SHN_FBSD_CACHED for successful return. If we 1447 * modified symbol table for the object but found an 1448 * unresolved symbol, there is no reason to roll back. 1449 */ 1450 elf_obj_cleanup_globals_cache(ef); 1451 1452 return (0); 1453 } 1454 1455 static int 1456 relocate_file(elf_file_t ef) 1457 { 1458 int error; 1459 1460 error = relocate_file1(ef, false); 1461 if (error == 0) 1462 error = relocate_file1(ef, true); 1463 return (error); 1464 } 1465 1466 static int 1467 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym, 1468 bool see_local) 1469 { 1470 elf_file_t ef = (elf_file_t)lf; 1471 const Elf_Sym *symp; 1472 const char *strp; 1473 int i; 1474 1475 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1476 strp = ef->ddbstrtab + symp->st_name; 1477 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { 1478 if (see_local || 1479 ELF_ST_BIND(symp->st_info) == STB_GLOBAL) { 1480 *sym = (c_linker_sym_t) symp; 1481 return (0); 1482 } 1483 return (ENOENT); 1484 } 1485 } 1486 return (ENOENT); 1487 } 1488 1489 static int 1490 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1491 { 1492 return (link_elf_lookup_symbol1(lf, name, sym, 1493 link_elf_obj_leak_locals)); 1494 } 1495 1496 static int 1497 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name, 1498 c_linker_sym_t *sym) 1499 { 1500 return (link_elf_lookup_symbol1(lf, name, sym, true)); 1501 } 1502 1503 static int 1504 link_elf_lookup_debug_symbol_ctf(linker_file_t lf, const char *name, 1505 c_linker_sym_t *sym, linker_ctf_t *lc) 1506 { 1507 if (link_elf_lookup_debug_symbol(lf, name, sym)) 1508 return (ENOENT); 1509 1510 return (link_elf_ctf_get_ddb(lf, lc)); 1511 } 1512 1513 static int 1514 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym, 1515 linker_symval_t *symval, bool see_local) 1516 { 1517 elf_file_t ef; 1518 const Elf_Sym *es; 1519 caddr_t val; 1520 1521 ef = (elf_file_t) lf; 1522 es = (const Elf_Sym*) sym; 1523 val = (caddr_t)es->st_value; 1524 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1525 if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL) 1526 return (ENOENT); 1527 symval->name = ef->ddbstrtab + es->st_name; 1528 val = (caddr_t)es->st_value; 1529 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1530 val = ((caddr_t (*)(void))val)(); 1531 symval->value = val; 1532 symval->size = es->st_size; 1533 return (0); 1534 } 1535 return (ENOENT); 1536 } 1537 1538 static int 1539 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1540 linker_symval_t *symval) 1541 { 1542 return (link_elf_symbol_values1(lf, sym, symval, 1543 link_elf_obj_leak_locals)); 1544 } 1545 1546 static int 1547 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1548 linker_symval_t *symval) 1549 { 1550 return (link_elf_symbol_values1(lf, sym, symval, true)); 1551 } 1552 1553 static int 1554 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1555 c_linker_sym_t *sym, long *diffp) 1556 { 1557 elf_file_t ef = (elf_file_t)lf; 1558 u_long off = (uintptr_t)(void *)value; 1559 u_long diff = off; 1560 u_long st_value; 1561 const Elf_Sym *es; 1562 const Elf_Sym *best = NULL; 1563 int i; 1564 1565 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1566 if (es->st_name == 0) 1567 continue; 1568 st_value = es->st_value; 1569 if (off >= st_value) { 1570 if (off - st_value < diff) { 1571 diff = off - st_value; 1572 best = es; 1573 if (diff == 0) 1574 break; 1575 } else if (off - st_value == diff) { 1576 best = es; 1577 } 1578 } 1579 } 1580 if (best == NULL) 1581 *diffp = off; 1582 else 1583 *diffp = diff; 1584 *sym = (c_linker_sym_t) best; 1585 1586 return (0); 1587 } 1588 1589 /* 1590 * Look up a linker set on an ELF system. 1591 */ 1592 static int 1593 link_elf_lookup_set(linker_file_t lf, const char *name, 1594 void ***startp, void ***stopp, int *countp) 1595 { 1596 elf_file_t ef = (elf_file_t)lf; 1597 void **start, **stop; 1598 int i, count; 1599 1600 /* Relative to section number */ 1601 for (i = 0; i < ef->nprogtab; i++) { 1602 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && 1603 strcmp(ef->progtab[i].name + 4, name) == 0) { 1604 start = (void **)ef->progtab[i].addr; 1605 stop = (void **)((char *)ef->progtab[i].addr + 1606 ef->progtab[i].size); 1607 count = stop - start; 1608 if (startp) 1609 *startp = start; 1610 if (stopp) 1611 *stopp = stop; 1612 if (countp) 1613 *countp = count; 1614 return (0); 1615 } 1616 } 1617 return (ESRCH); 1618 } 1619 1620 static int 1621 link_elf_each_function_name(linker_file_t file, 1622 int (*callback)(const char *, void *), void *opaque) 1623 { 1624 elf_file_t ef = (elf_file_t)file; 1625 const Elf_Sym *symp; 1626 int i, error; 1627 1628 /* Exhaustive search */ 1629 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1630 if (symp->st_value != 0 && 1631 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1632 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1633 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1634 if (error) 1635 return (error); 1636 } 1637 } 1638 return (0); 1639 } 1640 1641 static int 1642 link_elf_each_function_nameval(linker_file_t file, 1643 linker_function_nameval_callback_t callback, void *opaque) 1644 { 1645 linker_symval_t symval; 1646 elf_file_t ef = (elf_file_t)file; 1647 const Elf_Sym *symp; 1648 int i, error; 1649 1650 /* Exhaustive search */ 1651 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1652 if (symp->st_value != 0 && 1653 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1654 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1655 error = link_elf_debug_symbol_values(file, 1656 (c_linker_sym_t)symp, &symval); 1657 if (error == 0) 1658 error = callback(file, i, &symval, opaque); 1659 if (error != 0) 1660 return (error); 1661 } 1662 } 1663 return (0); 1664 } 1665 1666 static void 1667 elf_obj_cleanup_globals_cache(elf_file_t ef) 1668 { 1669 Elf_Sym *sym; 1670 Elf_Size i; 1671 1672 for (i = 0; i < ef->ddbsymcnt; i++) { 1673 sym = ef->ddbsymtab + i; 1674 if (sym->st_shndx == SHN_FBSD_CACHED) { 1675 sym->st_shndx = SHN_UNDEF; 1676 sym->st_value = 0; 1677 } 1678 } 1679 } 1680 1681 /* 1682 * Symbol lookup function that can be used when the symbol index is known (ie 1683 * in relocations). It uses the symbol index instead of doing a fully fledged 1684 * hash table based lookup when such is valid. For example for local symbols. 1685 * This is not only more efficient, it's also more correct. It's not always 1686 * the case that the symbol can be found through the hash table. 1687 */ 1688 static int 1689 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1690 { 1691 elf_file_t ef = (elf_file_t)lf; 1692 Elf_Sym *sym; 1693 const char *symbol; 1694 Elf_Addr res1; 1695 1696 /* Don't even try to lookup the symbol if the index is bogus. */ 1697 if (symidx >= ef->ddbsymcnt) { 1698 *res = 0; 1699 return (EINVAL); 1700 } 1701 1702 sym = ef->ddbsymtab + symidx; 1703 1704 /* Quick answer if there is a definition included. */ 1705 if (sym->st_shndx != SHN_UNDEF) { 1706 res1 = (Elf_Addr)sym->st_value; 1707 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC) 1708 res1 = ((Elf_Addr (*)(void))res1)(); 1709 *res = res1; 1710 return (0); 1711 } 1712 1713 /* If we get here, then it is undefined and needs a lookup. */ 1714 switch (ELF_ST_BIND(sym->st_info)) { 1715 case STB_LOCAL: 1716 /* Local, but undefined? huh? */ 1717 *res = 0; 1718 return (EINVAL); 1719 1720 case STB_GLOBAL: 1721 case STB_WEAK: 1722 /* Relative to Data or Function name */ 1723 symbol = ef->ddbstrtab + sym->st_name; 1724 1725 /* Force a lookup failure if the symbol name is bogus. */ 1726 if (*symbol == 0) { 1727 *res = 0; 1728 return (EINVAL); 1729 } 1730 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); 1731 1732 /* 1733 * Cache global lookups during module relocation. The failure 1734 * case is particularly expensive for callers, who must scan 1735 * through the entire globals table doing strcmp(). Cache to 1736 * avoid doing such work repeatedly. 1737 * 1738 * After relocation is complete, undefined globals will be 1739 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), 1740 * above. 1741 */ 1742 if (res1 != 0) { 1743 sym->st_shndx = SHN_FBSD_CACHED; 1744 sym->st_value = res1; 1745 *res = res1; 1746 return (0); 1747 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 1748 sym->st_value = 0; 1749 *res = 0; 1750 return (0); 1751 } 1752 return (EINVAL); 1753 1754 default: 1755 return (EINVAL); 1756 } 1757 } 1758 1759 static void 1760 link_elf_fix_link_set(elf_file_t ef) 1761 { 1762 static const char startn[] = "__start_"; 1763 static const char stopn[] = "__stop_"; 1764 Elf_Sym *sym; 1765 const char *sym_name, *linkset_name; 1766 Elf_Addr startp, stopp; 1767 Elf_Size symidx; 1768 int start, i; 1769 1770 startp = stopp = 0; 1771 for (symidx = 1 /* zero entry is special */; 1772 symidx < ef->ddbsymcnt; symidx++) { 1773 sym = ef->ddbsymtab + symidx; 1774 if (sym->st_shndx != SHN_UNDEF) 1775 continue; 1776 1777 sym_name = ef->ddbstrtab + sym->st_name; 1778 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { 1779 start = 1; 1780 linkset_name = sym_name + sizeof(startn) - 1; 1781 } 1782 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { 1783 start = 0; 1784 linkset_name = sym_name + sizeof(stopn) - 1; 1785 } 1786 else 1787 continue; 1788 1789 for (i = 0; i < ef->nprogtab; i++) { 1790 if (strcmp(ef->progtab[i].name, linkset_name) == 0) { 1791 startp = (Elf_Addr)ef->progtab[i].addr; 1792 stopp = (Elf_Addr)(startp + ef->progtab[i].size); 1793 break; 1794 } 1795 } 1796 if (i == ef->nprogtab) 1797 continue; 1798 1799 sym->st_value = start ? startp : stopp; 1800 sym->st_shndx = i; 1801 } 1802 } 1803 1804 static int 1805 link_elf_reloc_local(linker_file_t lf, bool ifuncs) 1806 { 1807 elf_file_t ef = (elf_file_t)lf; 1808 const Elf_Rel *rellim; 1809 const Elf_Rel *rel; 1810 const Elf_Rela *relalim; 1811 const Elf_Rela *rela; 1812 const Elf_Sym *sym; 1813 Elf_Addr base; 1814 int i; 1815 Elf_Size symidx; 1816 1817 link_elf_fix_link_set(ef); 1818 1819 /* Perform relocations without addend if there are any: */ 1820 for (i = 0; i < ef->nreltab; i++) { 1821 rel = ef->reltab[i].rel; 1822 if (rel == NULL) { 1823 link_elf_error(ef->lf.filename, "lost a reltab"); 1824 return (ENOEXEC); 1825 } 1826 rellim = rel + ef->reltab[i].nrel; 1827 base = findbase(ef, ef->reltab[i].sec); 1828 if (base == 0) { 1829 link_elf_error(ef->lf.filename, "lost base for reltab"); 1830 return (ENOEXEC); 1831 } 1832 for ( ; rel < rellim; rel++) { 1833 symidx = ELF_R_SYM(rel->r_info); 1834 if (symidx >= ef->ddbsymcnt) 1835 continue; 1836 sym = ef->ddbsymtab + symidx; 1837 /* Only do local relocs */ 1838 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1839 continue; 1840 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1841 elf_is_ifunc_reloc(rel->r_info)) != ifuncs) 1842 continue; 1843 if (elf_reloc_local(lf, base, rel, ELF_RELOC_REL, 1844 elf_obj_lookup) != 0) 1845 return (ENOEXEC); 1846 } 1847 } 1848 1849 /* Perform relocations with addend if there are any: */ 1850 for (i = 0; i < ef->nrelatab; i++) { 1851 rela = ef->relatab[i].rela; 1852 if (rela == NULL) { 1853 link_elf_error(ef->lf.filename, "lost a relatab!"); 1854 return (ENOEXEC); 1855 } 1856 relalim = rela + ef->relatab[i].nrela; 1857 base = findbase(ef, ef->relatab[i].sec); 1858 if (base == 0) { 1859 link_elf_error(ef->lf.filename, "lost base for reltab"); 1860 return (ENOEXEC); 1861 } 1862 for ( ; rela < relalim; rela++) { 1863 symidx = ELF_R_SYM(rela->r_info); 1864 if (symidx >= ef->ddbsymcnt) 1865 continue; 1866 sym = ef->ddbsymtab + symidx; 1867 /* Only do local relocs */ 1868 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) 1869 continue; 1870 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC || 1871 elf_is_ifunc_reloc(rela->r_info)) != ifuncs) 1872 continue; 1873 if (elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, 1874 elf_obj_lookup) != 0) 1875 return (ENOEXEC); 1876 } 1877 } 1878 return (0); 1879 } 1880 1881 static long 1882 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1883 { 1884 elf_file_t ef = (elf_file_t)lf; 1885 1886 *symtab = ef->ddbsymtab; 1887 if (*symtab == NULL) 1888 return (0); 1889 return (ef->ddbsymcnt); 1890 } 1891 1892 static long 1893 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1894 { 1895 elf_file_t ef = (elf_file_t)lf; 1896 1897 *strtab = ef->ddbstrtab; 1898 if (*strtab == NULL) 1899 return (0); 1900 return (ef->ddbstrcnt); 1901 } 1902 1903 #ifdef VIMAGE 1904 static void 1905 link_elf_propagate_vnets(linker_file_t lf) 1906 { 1907 elf_file_t ef = (elf_file_t) lf; 1908 1909 if (ef->progtab) { 1910 for (int i = 0; i < ef->nprogtab; i++) { 1911 if (ef->progtab[i].size == 0) 1912 continue; 1913 if (ef->progtab[i].name == NULL) 1914 continue; 1915 if (strcmp(ef->progtab[i].name, VNET_SETNAME) == 0) { 1916 vnet_data_copy(ef->progtab[i].addr, 1917 ef->progtab[i].size); 1918 break; 1919 } 1920 } 1921 } 1922 } 1923 #endif 1924