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