1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998-2000 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_ddb.h" 33 #include "opt_gdb.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #ifdef GPROF 38 #include <sys/gmon.h> 39 #endif 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #ifdef SPARSE_MAPPING 44 #include <sys/mman.h> 45 #endif 46 #include <sys/mutex.h> 47 #include <sys/mount.h> 48 #include <sys/pcpu.h> 49 #include <sys/proc.h> 50 #include <sys/namei.h> 51 #include <sys/fcntl.h> 52 #include <sys/vnode.h> 53 #include <sys/linker.h> 54 #include <sys/sysctl.h> 55 56 #include <machine/elf.h> 57 58 #include <net/vnet.h> 59 60 #include <security/mac/mac_framework.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_param.h> 64 #ifdef SPARSE_MAPPING 65 #include <vm/vm_object.h> 66 #include <vm/vm_kern.h> 67 #include <vm/vm_extern.h> 68 #endif 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 72 #include <sys/link_elf.h> 73 74 #include "linker_if.h" 75 76 #define MAXSEGS 4 77 78 typedef struct elf_file { 79 struct linker_file lf; /* Common fields */ 80 int preloaded; /* Was file pre-loaded */ 81 caddr_t address; /* Relocation address */ 82 #ifdef SPARSE_MAPPING 83 vm_object_t object; /* VM object to hold file pages */ 84 #endif 85 Elf_Dyn *dynamic; /* Symbol table etc. */ 86 Elf_Hashelt nbuckets; /* DT_HASH info */ 87 Elf_Hashelt nchains; 88 const Elf_Hashelt *buckets; 89 const Elf_Hashelt *chains; 90 caddr_t hash; 91 caddr_t strtab; /* DT_STRTAB */ 92 int strsz; /* DT_STRSZ */ 93 const Elf_Sym *symtab; /* DT_SYMTAB */ 94 Elf_Addr *got; /* DT_PLTGOT */ 95 const Elf_Rel *pltrel; /* DT_JMPREL */ 96 int pltrelsize; /* DT_PLTRELSZ */ 97 const Elf_Rela *pltrela; /* DT_JMPREL */ 98 int pltrelasize; /* DT_PLTRELSZ */ 99 const Elf_Rel *rel; /* DT_REL */ 100 int relsize; /* DT_RELSZ */ 101 const Elf_Rela *rela; /* DT_RELA */ 102 int relasize; /* DT_RELASZ */ 103 caddr_t modptr; 104 const Elf_Sym *ddbsymtab; /* The symbol table we are using */ 105 long ddbsymcnt; /* Number of symbols */ 106 caddr_t ddbstrtab; /* String table */ 107 long ddbstrcnt; /* number of bytes in string table */ 108 caddr_t symbase; /* malloc'ed symbold base */ 109 caddr_t strbase; /* malloc'ed string base */ 110 caddr_t ctftab; /* CTF table */ 111 long ctfcnt; /* number of bytes in CTF table */ 112 caddr_t ctfoff; /* CTF offset table */ 113 caddr_t typoff; /* Type offset table */ 114 long typlen; /* Number of type entries. */ 115 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */ 116 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */ 117 Elf_Addr pcpu_base; /* Relocated pcpu set address. */ 118 #ifdef VIMAGE 119 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */ 120 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */ 121 Elf_Addr vnet_base; /* Relocated vnet set address. */ 122 #endif 123 #ifdef GDB 124 struct link_map gdb; /* hooks for gdb */ 125 #endif 126 } *elf_file_t; 127 128 struct elf_set { 129 Elf_Addr es_start; 130 Elf_Addr es_stop; 131 Elf_Addr es_base; 132 TAILQ_ENTRY(elf_set) es_link; 133 }; 134 135 TAILQ_HEAD(elf_set_head, elf_set); 136 137 #include <kern/kern_ctf.c> 138 139 static int link_elf_link_common_finish(linker_file_t); 140 static int link_elf_link_preload(linker_class_t cls, 141 const char *, linker_file_t *); 142 static int link_elf_link_preload_finish(linker_file_t); 143 static int link_elf_load_file(linker_class_t, const char *, 144 linker_file_t *); 145 static int link_elf_lookup_symbol(linker_file_t, const char *, 146 c_linker_sym_t *); 147 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 148 linker_symval_t *); 149 static int link_elf_search_symbol(linker_file_t, caddr_t, 150 c_linker_sym_t *, long *); 151 152 static void link_elf_unload_file(linker_file_t); 153 static void link_elf_unload_preload(linker_file_t); 154 static int link_elf_lookup_set(linker_file_t, const char *, 155 void ***, void ***, int *); 156 static int link_elf_each_function_name(linker_file_t, 157 int (*)(const char *, void *), void *); 158 static int link_elf_each_function_nameval(linker_file_t, 159 linker_function_nameval_callback_t, void *); 160 static void link_elf_reloc_local(linker_file_t); 161 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 162 static long link_elf_strtab_get(linker_file_t, caddr_t *); 163 static int elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *); 164 165 static kobj_method_t link_elf_methods[] = { 166 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 167 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 168 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 169 KOBJMETHOD(linker_unload, link_elf_unload_file), 170 KOBJMETHOD(linker_load_file, link_elf_load_file), 171 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 172 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 173 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 174 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 175 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 176 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 177 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 178 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 179 KOBJMETHOD_END 180 }; 181 182 static struct linker_class link_elf_class = { 183 #if ELF_TARG_CLASS == ELFCLASS32 184 "elf32", 185 #else 186 "elf64", 187 #endif 188 link_elf_methods, sizeof(struct elf_file) 189 }; 190 191 typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase, 192 const void *data, int type, elf_lookup_fn lookup); 193 194 static int parse_dynamic(elf_file_t); 195 static int relocate_file(elf_file_t); 196 static int relocate_file1(elf_file_t ef, elf_lookup_fn lookup, 197 elf_reloc_fn reloc, bool ifuncs); 198 static int link_elf_preload_parse_symbols(elf_file_t); 199 200 static struct elf_set_head set_pcpu_list; 201 #ifdef VIMAGE 202 static struct elf_set_head set_vnet_list; 203 #endif 204 205 static void 206 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base) 207 { 208 struct elf_set *set, *iter; 209 210 set = malloc(sizeof(*set), M_LINKER, M_WAITOK); 211 set->es_start = start; 212 set->es_stop = stop; 213 set->es_base = base; 214 215 TAILQ_FOREACH(iter, list, es_link) { 216 217 KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) || 218 (set->es_start > iter->es_start && set->es_stop > iter->es_stop), 219 ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx", 220 (uintmax_t)set->es_start, (uintmax_t)set->es_stop, 221 (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop)); 222 223 if (iter->es_start > set->es_start) { 224 TAILQ_INSERT_BEFORE(iter, set, es_link); 225 break; 226 } 227 } 228 229 if (iter == NULL) 230 TAILQ_INSERT_TAIL(list, set, es_link); 231 } 232 233 static int 234 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base) 235 { 236 struct elf_set *set; 237 238 TAILQ_FOREACH(set, list, es_link) { 239 if (addr < set->es_start) 240 return (0); 241 if (addr < set->es_stop) { 242 *start = set->es_start; 243 *base = set->es_base; 244 return (1); 245 } 246 } 247 248 return (0); 249 } 250 251 static void 252 elf_set_delete(struct elf_set_head *list, Elf_Addr start) 253 { 254 struct elf_set *set; 255 256 TAILQ_FOREACH(set, list, es_link) { 257 if (start < set->es_start) 258 break; 259 if (start == set->es_start) { 260 TAILQ_REMOVE(list, set, es_link); 261 free(set, M_LINKER); 262 return; 263 } 264 } 265 KASSERT(0, ("deleting unknown linker set (start = 0x%jx)", 266 (uintmax_t)start)); 267 } 268 269 #ifdef GDB 270 static void r_debug_state(struct r_debug *, struct link_map *); 271 272 /* 273 * A list of loaded modules for GDB to use for loading symbols. 274 */ 275 struct r_debug r_debug; 276 277 #define GDB_STATE(s) do { \ 278 r_debug.r_state = s; r_debug_state(NULL, NULL); \ 279 } while (0) 280 281 /* 282 * Function for the debugger to set a breakpoint on to gain control. 283 */ 284 static void 285 r_debug_state(struct r_debug *dummy_one __unused, 286 struct link_map *dummy_two __unused) 287 { 288 } 289 290 static void 291 link_elf_add_gdb(struct link_map *l) 292 { 293 struct link_map *prev; 294 295 l->l_next = NULL; 296 297 if (r_debug.r_map == NULL) { 298 /* Add first. */ 299 l->l_prev = NULL; 300 r_debug.r_map = l; 301 } else { 302 /* Append to list. */ 303 for (prev = r_debug.r_map; 304 prev->l_next != NULL; 305 prev = prev->l_next) 306 ; 307 l->l_prev = prev; 308 prev->l_next = l; 309 } 310 } 311 312 static void 313 link_elf_delete_gdb(struct link_map *l) 314 { 315 if (l->l_prev == NULL) { 316 /* Remove first. */ 317 if ((r_debug.r_map = l->l_next) != NULL) 318 l->l_next->l_prev = NULL; 319 } else { 320 /* Remove any but first. */ 321 if ((l->l_prev->l_next = l->l_next) != NULL) 322 l->l_next->l_prev = l->l_prev; 323 } 324 } 325 #endif /* GDB */ 326 327 /* 328 * The kernel symbol table starts here. 329 */ 330 extern struct _dynamic _DYNAMIC; 331 332 static void 333 link_elf_error(const char *filename, const char *s) 334 { 335 if (filename == NULL) 336 printf("kldload: %s\n", s); 337 else 338 printf("kldload: %s: %s\n", filename, s); 339 } 340 341 static void 342 link_elf_invoke_ctors(caddr_t addr, size_t size) 343 { 344 void (**ctor)(void); 345 size_t i, cnt; 346 347 if (addr == NULL || size == 0) 348 return; 349 cnt = size / sizeof(*ctor); 350 ctor = (void *)addr; 351 for (i = 0; i < cnt; i++) { 352 if (ctor[i] != NULL) 353 (*ctor[i])(); 354 } 355 } 356 357 /* 358 * Actions performed after linking/loading both the preloaded kernel and any 359 * modules; whether preloaded or dynamicly loaded. 360 */ 361 static int 362 link_elf_link_common_finish(linker_file_t lf) 363 { 364 #ifdef GDB 365 elf_file_t ef = (elf_file_t)lf; 366 char *newfilename; 367 #endif 368 int error; 369 370 /* Notify MD code that a module is being loaded. */ 371 error = elf_cpu_load_file(lf); 372 if (error != 0) 373 return (error); 374 375 #ifdef GDB 376 GDB_STATE(RT_ADD); 377 ef->gdb.l_addr = lf->address; 378 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 379 strcpy(newfilename, lf->filename); 380 ef->gdb.l_name = newfilename; 381 ef->gdb.l_ld = ef->dynamic; 382 link_elf_add_gdb(&ef->gdb); 383 GDB_STATE(RT_CONSISTENT); 384 #endif 385 386 /* Invoke .ctors */ 387 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); 388 return (0); 389 } 390 391 extern vm_offset_t __startkernel, __endkernel; 392 393 static unsigned long kern_relbase = KERNBASE; 394 395 SYSCTL_ULONG(_kern, OID_AUTO, base_address, CTLFLAG_RD, 396 SYSCTL_NULL_ULONG_PTR, KERNBASE, "Kernel base address"); 397 SYSCTL_ULONG(_kern, OID_AUTO, relbase_address, CTLFLAG_RD, 398 &kern_relbase, 0, "Kernel relocated base address"); 399 400 static void 401 link_elf_init(void* arg) 402 { 403 Elf_Dyn *dp; 404 Elf_Addr *ctors_addrp; 405 Elf_Size *ctors_sizep; 406 caddr_t modptr, baseptr, sizeptr; 407 elf_file_t ef; 408 const char *modname; 409 410 linker_add_class(&link_elf_class); 411 412 dp = (Elf_Dyn *)&_DYNAMIC; 413 modname = NULL; 414 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 415 if (modptr == NULL) 416 modptr = preload_search_by_type("elf kernel"); 417 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 418 if (modname == NULL) 419 modname = "kernel"; 420 linker_kernel_file = linker_make_file(modname, &link_elf_class); 421 if (linker_kernel_file == NULL) 422 panic("%s: Can't create linker structures for kernel", 423 __func__); 424 425 ef = (elf_file_t) linker_kernel_file; 426 ef->preloaded = 1; 427 #ifdef __powerpc__ 428 ef->address = (caddr_t) (__startkernel - KERNBASE); 429 #else 430 ef->address = 0; 431 #endif 432 #ifdef SPARSE_MAPPING 433 ef->object = NULL; 434 #endif 435 ef->dynamic = dp; 436 437 if (dp != NULL) 438 parse_dynamic(ef); 439 #ifdef __powerpc__ 440 linker_kernel_file->address = (caddr_t)__startkernel; 441 linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel); 442 kern_relbase = (unsigned long)__startkernel; 443 #else 444 linker_kernel_file->address += KERNBASE; 445 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 446 #endif 447 448 if (modptr != NULL) { 449 ef->modptr = modptr; 450 baseptr = preload_search_info(modptr, MODINFO_ADDR); 451 if (baseptr != NULL) 452 linker_kernel_file->address = *(caddr_t *)baseptr; 453 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 454 if (sizeptr != NULL) 455 linker_kernel_file->size = *(size_t *)sizeptr; 456 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 457 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 458 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 459 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 460 if (ctors_addrp != NULL && ctors_sizep != NULL) { 461 linker_kernel_file->ctors_addr = ef->address + 462 *ctors_addrp; 463 linker_kernel_file->ctors_size = *ctors_sizep; 464 } 465 } 466 (void)link_elf_preload_parse_symbols(ef); 467 468 #ifdef GDB 469 r_debug.r_map = NULL; 470 r_debug.r_brk = r_debug_state; 471 r_debug.r_state = RT_CONSISTENT; 472 #endif 473 474 (void)link_elf_link_common_finish(linker_kernel_file); 475 linker_kernel_file->flags |= LINKER_FILE_LINKED; 476 TAILQ_INIT(&set_pcpu_list); 477 #ifdef VIMAGE 478 TAILQ_INIT(&set_vnet_list); 479 #endif 480 } 481 482 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL); 483 484 static int 485 link_elf_preload_parse_symbols(elf_file_t ef) 486 { 487 caddr_t pointer; 488 caddr_t ssym, esym, base; 489 caddr_t strtab; 490 int strcnt; 491 Elf_Sym *symtab; 492 int symcnt; 493 494 if (ef->modptr == NULL) 495 return (0); 496 pointer = preload_search_info(ef->modptr, 497 MODINFO_METADATA | MODINFOMD_SSYM); 498 if (pointer == NULL) 499 return (0); 500 ssym = *(caddr_t *)pointer; 501 pointer = preload_search_info(ef->modptr, 502 MODINFO_METADATA | MODINFOMD_ESYM); 503 if (pointer == NULL) 504 return (0); 505 esym = *(caddr_t *)pointer; 506 507 base = ssym; 508 509 symcnt = *(long *)base; 510 base += sizeof(long); 511 symtab = (Elf_Sym *)base; 512 base += roundup(symcnt, sizeof(long)); 513 514 if (base > esym || base < ssym) { 515 printf("Symbols are corrupt!\n"); 516 return (EINVAL); 517 } 518 519 strcnt = *(long *)base; 520 base += sizeof(long); 521 strtab = base; 522 base += roundup(strcnt, sizeof(long)); 523 524 if (base > esym || base < ssym) { 525 printf("Symbols are corrupt!\n"); 526 return (EINVAL); 527 } 528 529 ef->ddbsymtab = symtab; 530 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 531 ef->ddbstrtab = strtab; 532 ef->ddbstrcnt = strcnt; 533 534 return (0); 535 } 536 537 static int 538 parse_dynamic(elf_file_t ef) 539 { 540 Elf_Dyn *dp; 541 int plttype = DT_REL; 542 543 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 544 switch (dp->d_tag) { 545 case DT_HASH: 546 { 547 /* From src/libexec/rtld-elf/rtld.c */ 548 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 549 (ef->address + dp->d_un.d_ptr); 550 ef->nbuckets = hashtab[0]; 551 ef->nchains = hashtab[1]; 552 ef->buckets = hashtab + 2; 553 ef->chains = ef->buckets + ef->nbuckets; 554 break; 555 } 556 case DT_STRTAB: 557 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 558 break; 559 case DT_STRSZ: 560 ef->strsz = dp->d_un.d_val; 561 break; 562 case DT_SYMTAB: 563 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 564 break; 565 case DT_SYMENT: 566 if (dp->d_un.d_val != sizeof(Elf_Sym)) 567 return (ENOEXEC); 568 break; 569 case DT_PLTGOT: 570 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 571 break; 572 case DT_REL: 573 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 574 break; 575 case DT_RELSZ: 576 ef->relsize = dp->d_un.d_val; 577 break; 578 case DT_RELENT: 579 if (dp->d_un.d_val != sizeof(Elf_Rel)) 580 return (ENOEXEC); 581 break; 582 case DT_JMPREL: 583 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 584 break; 585 case DT_PLTRELSZ: 586 ef->pltrelsize = dp->d_un.d_val; 587 break; 588 case DT_RELA: 589 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 590 break; 591 case DT_RELASZ: 592 ef->relasize = dp->d_un.d_val; 593 break; 594 case DT_RELAENT: 595 if (dp->d_un.d_val != sizeof(Elf_Rela)) 596 return (ENOEXEC); 597 break; 598 case DT_PLTREL: 599 plttype = dp->d_un.d_val; 600 if (plttype != DT_REL && plttype != DT_RELA) 601 return (ENOEXEC); 602 break; 603 #ifdef GDB 604 case DT_DEBUG: 605 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 606 break; 607 #endif 608 } 609 } 610 611 if (plttype == DT_RELA) { 612 ef->pltrela = (const Elf_Rela *)ef->pltrel; 613 ef->pltrel = NULL; 614 ef->pltrelasize = ef->pltrelsize; 615 ef->pltrelsize = 0; 616 } 617 618 ef->ddbsymtab = ef->symtab; 619 ef->ddbsymcnt = ef->nchains; 620 ef->ddbstrtab = ef->strtab; 621 ef->ddbstrcnt = ef->strsz; 622 623 return elf_cpu_parse_dynamic(&ef->lf, ef->dynamic); 624 } 625 626 #define LS_PADDING 0x90909090 627 static int 628 parse_dpcpu(elf_file_t ef) 629 { 630 int error, size; 631 #if defined(__i386__) 632 uint32_t pad; 633 #endif 634 635 ef->pcpu_start = 0; 636 ef->pcpu_stop = 0; 637 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 638 (void ***)&ef->pcpu_stop, NULL); 639 /* Error just means there is no pcpu set to relocate. */ 640 if (error != 0) 641 return (0); 642 size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start; 643 /* Empty set? */ 644 if (size < 1) 645 return (0); 646 #if defined(__i386__) 647 /* In case we do find __start/stop_set_ symbols double-check. */ 648 if (size < 4) { 649 uprintf("Kernel module '%s' must be recompiled with " 650 "linker script\n", ef->lf.pathname); 651 return (ENOEXEC); 652 } 653 654 /* Padding from linker-script correct? */ 655 pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad)); 656 if (pad != LS_PADDING) { 657 uprintf("Kernel module '%s' must be recompiled with " 658 "linker script, invalid padding %#04x (%#04x)\n", 659 ef->lf.pathname, pad, LS_PADDING); 660 return (ENOEXEC); 661 } 662 /* If we only have valid padding, nothing to do. */ 663 if (size == 4) 664 return (0); 665 #endif 666 /* 667 * Allocate space in the primary pcpu area. Copy in our 668 * initialization from the data section and then initialize 669 * all per-cpu storage from that. 670 */ 671 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size); 672 if (ef->pcpu_base == 0) { 673 printf("%s: pcpu module space is out of space; " 674 "cannot allocate %d for %s\n", 675 __func__, size, ef->lf.pathname); 676 return (ENOSPC); 677 } 678 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size); 679 dpcpu_copy((void *)ef->pcpu_base, size); 680 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 681 ef->pcpu_base); 682 683 return (0); 684 } 685 686 #ifdef VIMAGE 687 static int 688 parse_vnet(elf_file_t ef) 689 { 690 int error, size; 691 #if defined(__i386__) 692 uint32_t pad; 693 #endif 694 695 ef->vnet_start = 0; 696 ef->vnet_stop = 0; 697 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 698 (void ***)&ef->vnet_stop, NULL); 699 /* Error just means there is no vnet data set to relocate. */ 700 if (error != 0) 701 return (0); 702 size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start; 703 /* Empty set? */ 704 if (size < 1) 705 return (0); 706 #if defined(__i386__) 707 /* In case we do find __start/stop_set_ symbols double-check. */ 708 if (size < 4) { 709 uprintf("Kernel module '%s' must be recompiled with " 710 "linker script\n", ef->lf.pathname); 711 return (ENOEXEC); 712 } 713 714 /* Padding from linker-script correct? */ 715 pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad)); 716 if (pad != LS_PADDING) { 717 uprintf("Kernel module '%s' must be recompiled with " 718 "linker script, invalid padding %#04x (%#04x)\n", 719 ef->lf.pathname, pad, LS_PADDING); 720 return (ENOEXEC); 721 } 722 /* If we only have valid padding, nothing to do. */ 723 if (size == 4) 724 return (0); 725 #endif 726 /* 727 * Allocate space in the primary vnet area. Copy in our 728 * initialization from the data section and then initialize 729 * all per-vnet storage from that. 730 */ 731 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size); 732 if (ef->vnet_base == 0) { 733 printf("%s: vnet module space is out of space; " 734 "cannot allocate %d for %s\n", 735 __func__, size, ef->lf.pathname); 736 return (ENOSPC); 737 } 738 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size); 739 vnet_data_copy((void *)ef->vnet_base, size); 740 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 741 ef->vnet_base); 742 743 return (0); 744 } 745 #endif 746 #undef LS_PADDING 747 748 /* 749 * Apply the specified protection to the loadable segments of a preloaded linker 750 * file. 751 */ 752 static int 753 preload_protect(elf_file_t ef, vm_prot_t prot) 754 { 755 #ifdef __amd64__ 756 Elf_Ehdr *hdr; 757 Elf_Phdr *phdr, *phlimit; 758 vm_prot_t nprot; 759 int error; 760 761 error = 0; 762 hdr = (Elf_Ehdr *)ef->address; 763 phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff); 764 phlimit = phdr + hdr->e_phnum; 765 for (; phdr < phlimit; phdr++) { 766 if (phdr->p_type != PT_LOAD) 767 continue; 768 769 nprot = prot | VM_PROT_READ; 770 if ((phdr->p_flags & PF_W) != 0) 771 nprot |= VM_PROT_WRITE; 772 if ((phdr->p_flags & PF_X) != 0) 773 nprot |= VM_PROT_EXECUTE; 774 error = pmap_change_prot((vm_offset_t)ef->address + 775 phdr->p_vaddr, round_page(phdr->p_memsz), nprot); 776 if (error != 0) 777 break; 778 } 779 return (error); 780 #else 781 return (0); 782 #endif 783 } 784 785 #ifdef __arm__ 786 /* 787 * Locate the ARM exception/unwind table info for DDB and stack(9) use by 788 * searching for the section header that describes it. There may be no unwind 789 * info, for example in a module containing only data. 790 */ 791 static void 792 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr) 793 { 794 int i; 795 796 for (i = 0; i < nhdr; i++) { 797 if (shdr[i].sh_type == SHT_ARM_EXIDX) { 798 lf->exidx_addr = shdr[i].sh_addr + lf->address; 799 lf->exidx_size = shdr[i].sh_size; 800 break; 801 } 802 } 803 } 804 805 /* 806 * Locate the section headers metadata in a preloaded module, then use it to 807 * locate the exception/unwind table in the module. The size of the metadata 808 * block is stored in a uint32 word immediately before the data itself, and a 809 * comment in preload_search_info() says it is safe to rely on that. 810 */ 811 static void 812 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr) 813 { 814 uint32_t *modinfo; 815 Elf_Shdr *shdr; 816 uint32_t nhdr; 817 818 modinfo = (uint32_t *)preload_search_info(modptr, 819 MODINFO_METADATA | MODINFOMD_SHDR); 820 if (modinfo != NULL) { 821 shdr = (Elf_Shdr *)modinfo; 822 nhdr = modinfo[-1] / sizeof(Elf_Shdr); 823 link_elf_locate_exidx(lf, shdr, nhdr); 824 } 825 } 826 827 #endif /* __arm__ */ 828 829 static int 830 link_elf_link_preload(linker_class_t cls, const char *filename, 831 linker_file_t *result) 832 { 833 Elf_Addr *ctors_addrp; 834 Elf_Size *ctors_sizep; 835 caddr_t modptr, baseptr, sizeptr, dynptr; 836 char *type; 837 elf_file_t ef; 838 linker_file_t lf; 839 int error; 840 vm_offset_t dp; 841 842 /* Look to see if we have the file preloaded */ 843 modptr = preload_search_by_name(filename); 844 if (modptr == NULL) 845 return (ENOENT); 846 847 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 848 baseptr = preload_search_info(modptr, MODINFO_ADDR); 849 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 850 dynptr = preload_search_info(modptr, 851 MODINFO_METADATA | MODINFOMD_DYNAMIC); 852 if (type == NULL || 853 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 854 strcmp(type, "elf module") != 0)) 855 return (EFTYPE); 856 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 857 return (EINVAL); 858 859 lf = linker_make_file(filename, &link_elf_class); 860 if (lf == NULL) 861 return (ENOMEM); 862 863 ef = (elf_file_t) lf; 864 ef->preloaded = 1; 865 ef->modptr = modptr; 866 ef->address = *(caddr_t *)baseptr; 867 #ifdef SPARSE_MAPPING 868 ef->object = NULL; 869 #endif 870 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 871 ef->dynamic = (Elf_Dyn *)dp; 872 lf->address = ef->address; 873 lf->size = *(size_t *)sizeptr; 874 875 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 876 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 877 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 878 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 879 if (ctors_addrp != NULL && ctors_sizep != NULL) { 880 lf->ctors_addr = ef->address + *ctors_addrp; 881 lf->ctors_size = *ctors_sizep; 882 } 883 884 #ifdef __arm__ 885 link_elf_locate_exidx_preload(lf, modptr); 886 #endif 887 888 error = parse_dynamic(ef); 889 if (error == 0) 890 error = parse_dpcpu(ef); 891 #ifdef VIMAGE 892 if (error == 0) 893 error = parse_vnet(ef); 894 #endif 895 if (error == 0) 896 error = preload_protect(ef, VM_PROT_ALL); 897 if (error != 0) { 898 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 899 return (error); 900 } 901 link_elf_reloc_local(lf); 902 *result = lf; 903 return (0); 904 } 905 906 static int 907 link_elf_link_preload_finish(linker_file_t lf) 908 { 909 elf_file_t ef; 910 int error; 911 912 ef = (elf_file_t) lf; 913 error = relocate_file(ef); 914 if (error == 0) 915 error = preload_protect(ef, VM_PROT_NONE); 916 if (error != 0) 917 return (error); 918 (void)link_elf_preload_parse_symbols(ef); 919 920 return (link_elf_link_common_finish(lf)); 921 } 922 923 static int 924 link_elf_load_file(linker_class_t cls, const char* filename, 925 linker_file_t* result) 926 { 927 struct nameidata nd; 928 struct thread* td = curthread; /* XXX */ 929 Elf_Ehdr *hdr; 930 caddr_t firstpage, segbase; 931 int nbytes, i; 932 Elf_Phdr *phdr; 933 Elf_Phdr *phlimit; 934 Elf_Phdr *segs[MAXSEGS]; 935 int nsegs; 936 Elf_Phdr *phdyn; 937 caddr_t mapbase; 938 size_t mapsize; 939 Elf_Addr base_vaddr; 940 Elf_Addr base_vlimit; 941 int error = 0; 942 ssize_t resid; 943 int flags; 944 elf_file_t ef; 945 linker_file_t lf; 946 Elf_Shdr *shdr; 947 int symtabindex; 948 int symstrindex; 949 int shstrindex; 950 int symcnt; 951 int strcnt; 952 char *shstrs; 953 954 shdr = NULL; 955 lf = NULL; 956 shstrs = NULL; 957 958 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 959 flags = FREAD; 960 error = vn_open(&nd, &flags, 0, NULL); 961 if (error != 0) 962 return (error); 963 NDFREE(&nd, NDF_ONLY_PNBUF); 964 if (nd.ni_vp->v_type != VREG) { 965 error = ENOEXEC; 966 firstpage = NULL; 967 goto out; 968 } 969 #ifdef MAC 970 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 971 if (error != 0) { 972 firstpage = NULL; 973 goto out; 974 } 975 #endif 976 977 /* 978 * Read the elf header from the file. 979 */ 980 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 981 hdr = (Elf_Ehdr *)firstpage; 982 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 983 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 984 &resid, td); 985 nbytes = PAGE_SIZE - resid; 986 if (error != 0) 987 goto out; 988 989 if (!IS_ELF(*hdr)) { 990 error = ENOEXEC; 991 goto out; 992 } 993 994 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 995 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 996 link_elf_error(filename, "Unsupported file layout"); 997 error = ENOEXEC; 998 goto out; 999 } 1000 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 1001 hdr->e_version != EV_CURRENT) { 1002 link_elf_error(filename, "Unsupported file version"); 1003 error = ENOEXEC; 1004 goto out; 1005 } 1006 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 1007 error = ENOSYS; 1008 goto out; 1009 } 1010 if (hdr->e_machine != ELF_TARG_MACH) { 1011 link_elf_error(filename, "Unsupported machine"); 1012 error = ENOEXEC; 1013 goto out; 1014 } 1015 1016 /* 1017 * We rely on the program header being in the first page. 1018 * This is not strictly required by the ABI specification, but 1019 * it seems to always true in practice. And, it simplifies 1020 * things considerably. 1021 */ 1022 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 1023 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 1024 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 1025 link_elf_error(filename, "Unreadable program headers"); 1026 1027 /* 1028 * Scan the program header entries, and save key information. 1029 * 1030 * We rely on there being exactly two load segments, text and data, 1031 * in that order. 1032 */ 1033 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 1034 phlimit = phdr + hdr->e_phnum; 1035 nsegs = 0; 1036 phdyn = NULL; 1037 while (phdr < phlimit) { 1038 switch (phdr->p_type) { 1039 case PT_LOAD: 1040 if (nsegs == MAXSEGS) { 1041 link_elf_error(filename, "Too many sections"); 1042 error = ENOEXEC; 1043 goto out; 1044 } 1045 /* 1046 * XXX: We just trust they come in right order ?? 1047 */ 1048 segs[nsegs] = phdr; 1049 ++nsegs; 1050 break; 1051 1052 case PT_DYNAMIC: 1053 phdyn = phdr; 1054 break; 1055 1056 case PT_INTERP: 1057 error = ENOSYS; 1058 goto out; 1059 } 1060 1061 ++phdr; 1062 } 1063 if (phdyn == NULL) { 1064 link_elf_error(filename, "Object is not dynamically-linked"); 1065 error = ENOEXEC; 1066 goto out; 1067 } 1068 if (nsegs == 0) { 1069 link_elf_error(filename, "No sections"); 1070 error = ENOEXEC; 1071 goto out; 1072 } 1073 1074 /* 1075 * Allocate the entire address space of the object, to stake 1076 * out our contiguous region, and to establish the base 1077 * address for relocation. 1078 */ 1079 base_vaddr = trunc_page(segs[0]->p_vaddr); 1080 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 1081 segs[nsegs - 1]->p_memsz); 1082 mapsize = base_vlimit - base_vaddr; 1083 1084 lf = linker_make_file(filename, &link_elf_class); 1085 if (lf == NULL) { 1086 error = ENOMEM; 1087 goto out; 1088 } 1089 1090 ef = (elf_file_t) lf; 1091 #ifdef SPARSE_MAPPING 1092 ef->object = vm_object_allocate(OBJT_PHYS, atop(mapsize)); 1093 if (ef->object == NULL) { 1094 error = ENOMEM; 1095 goto out; 1096 } 1097 #ifdef __amd64__ 1098 mapbase = (caddr_t)KERNBASE; 1099 #else 1100 mapbase = (caddr_t)vm_map_min(kernel_map); 1101 #endif 1102 /* 1103 * Mapping protections are downgraded after relocation processing. 1104 */ 1105 error = vm_map_find(kernel_map, ef->object, 0, 1106 (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE, 1107 VM_PROT_ALL, VM_PROT_ALL, 0); 1108 if (error != 0) { 1109 vm_object_deallocate(ef->object); 1110 ef->object = NULL; 1111 goto out; 1112 } 1113 #else 1114 mapbase = malloc(mapsize, M_LINKER, M_EXEC | M_WAITOK); 1115 #endif 1116 ef->address = mapbase; 1117 1118 /* 1119 * Read the text and data sections and zero the bss. 1120 */ 1121 for (i = 0; i < nsegs; i++) { 1122 segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 1123 1124 #ifdef SPARSE_MAPPING 1125 /* 1126 * Consecutive segments may have different mapping permissions, 1127 * so be strict and verify that their mappings do not overlap. 1128 */ 1129 if (((vm_offset_t)segbase & PAGE_MASK) != 0) { 1130 error = EINVAL; 1131 goto out; 1132 } 1133 1134 error = vm_map_wire(kernel_map, 1135 (vm_offset_t)segbase, 1136 (vm_offset_t)segbase + round_page(segs[i]->p_memsz), 1137 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 1138 if (error != KERN_SUCCESS) { 1139 error = ENOMEM; 1140 goto out; 1141 } 1142 #endif 1143 1144 error = vn_rdwr(UIO_READ, nd.ni_vp, 1145 segbase, segs[i]->p_filesz, segs[i]->p_offset, 1146 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1147 &resid, td); 1148 if (error != 0) 1149 goto out; 1150 bzero(segbase + segs[i]->p_filesz, 1151 segs[i]->p_memsz - segs[i]->p_filesz); 1152 } 1153 1154 #ifdef GPROF 1155 /* Update profiling information with the new text segment. */ 1156 mtx_lock(&Giant); 1157 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 1158 segs[0]->p_memsz)); 1159 mtx_unlock(&Giant); 1160 #endif 1161 1162 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 1163 1164 lf->address = ef->address; 1165 lf->size = mapsize; 1166 1167 error = parse_dynamic(ef); 1168 if (error != 0) 1169 goto out; 1170 error = parse_dpcpu(ef); 1171 if (error != 0) 1172 goto out; 1173 #ifdef VIMAGE 1174 error = parse_vnet(ef); 1175 if (error != 0) 1176 goto out; 1177 #endif 1178 link_elf_reloc_local(lf); 1179 1180 VOP_UNLOCK(nd.ni_vp); 1181 error = linker_load_dependencies(lf); 1182 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 1183 if (error != 0) 1184 goto out; 1185 error = relocate_file(ef); 1186 if (error != 0) 1187 goto out; 1188 1189 #ifdef SPARSE_MAPPING 1190 /* 1191 * Downgrade permissions on text segment mappings now that relocation 1192 * processing is complete. Restrict permissions on read-only segments. 1193 */ 1194 for (i = 0; i < nsegs; i++) { 1195 vm_prot_t prot; 1196 1197 if (segs[i]->p_type != PT_LOAD) 1198 continue; 1199 1200 prot = VM_PROT_READ; 1201 if ((segs[i]->p_flags & PF_W) != 0) 1202 prot |= VM_PROT_WRITE; 1203 if ((segs[i]->p_flags & PF_X) != 0) 1204 prot |= VM_PROT_EXECUTE; 1205 segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 1206 error = vm_map_protect(kernel_map, 1207 (vm_offset_t)segbase, 1208 (vm_offset_t)segbase + round_page(segs[i]->p_memsz), 1209 prot, FALSE); 1210 if (error != KERN_SUCCESS) { 1211 error = ENOMEM; 1212 goto out; 1213 } 1214 } 1215 #endif 1216 1217 /* 1218 * Try and load the symbol table if it's present. (you can 1219 * strip it!) 1220 */ 1221 nbytes = hdr->e_shnum * hdr->e_shentsize; 1222 if (nbytes == 0 || hdr->e_shoff == 0) 1223 goto nosyms; 1224 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1225 error = vn_rdwr(UIO_READ, nd.ni_vp, 1226 (caddr_t)shdr, nbytes, hdr->e_shoff, 1227 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1228 &resid, td); 1229 if (error != 0) 1230 goto out; 1231 1232 /* Read section string table */ 1233 shstrindex = hdr->e_shstrndx; 1234 if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB && 1235 shdr[shstrindex].sh_size != 0) { 1236 nbytes = shdr[shstrindex].sh_size; 1237 shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1238 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes, 1239 shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 1240 td->td_ucred, NOCRED, &resid, td); 1241 if (error) 1242 goto out; 1243 } 1244 1245 symtabindex = -1; 1246 symstrindex = -1; 1247 for (i = 0; i < hdr->e_shnum; i++) { 1248 if (shdr[i].sh_type == SHT_SYMTAB) { 1249 symtabindex = i; 1250 symstrindex = shdr[i].sh_link; 1251 } else if (shstrs != NULL && shdr[i].sh_name != 0 && 1252 strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) { 1253 /* Record relocated address and size of .ctors. */ 1254 lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr; 1255 lf->ctors_size = shdr[i].sh_size; 1256 } 1257 } 1258 if (symtabindex < 0 || symstrindex < 0) 1259 goto nosyms; 1260 1261 symcnt = shdr[symtabindex].sh_size; 1262 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1263 strcnt = shdr[symstrindex].sh_size; 1264 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1265 1266 error = vn_rdwr(UIO_READ, nd.ni_vp, 1267 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1268 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1269 &resid, td); 1270 if (error != 0) 1271 goto out; 1272 error = vn_rdwr(UIO_READ, nd.ni_vp, 1273 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1274 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1275 &resid, td); 1276 if (error != 0) 1277 goto out; 1278 1279 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1280 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1281 ef->ddbstrcnt = strcnt; 1282 ef->ddbstrtab = ef->strbase; 1283 1284 nosyms: 1285 1286 #ifdef __arm__ 1287 link_elf_locate_exidx(lf, shdr, hdr->e_shnum); 1288 #endif 1289 1290 error = link_elf_link_common_finish(lf); 1291 if (error != 0) 1292 goto out; 1293 1294 *result = lf; 1295 1296 out: 1297 VOP_UNLOCK(nd.ni_vp); 1298 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1299 if (error != 0 && lf != NULL) 1300 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1301 free(shdr, M_LINKER); 1302 free(firstpage, M_LINKER); 1303 free(shstrs, M_LINKER); 1304 1305 return (error); 1306 } 1307 1308 Elf_Addr 1309 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1310 { 1311 elf_file_t ef; 1312 1313 KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class, 1314 ("elf_relocaddr: unexpected linker file %p", lf)); 1315 1316 ef = (elf_file_t)lf; 1317 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1318 return ((x - ef->pcpu_start) + ef->pcpu_base); 1319 #ifdef VIMAGE 1320 if (x >= ef->vnet_start && x < ef->vnet_stop) 1321 return ((x - ef->vnet_start) + ef->vnet_base); 1322 #endif 1323 return (x); 1324 } 1325 1326 static void 1327 link_elf_unload_file(linker_file_t file) 1328 { 1329 elf_file_t ef = (elf_file_t) file; 1330 1331 if (ef->pcpu_base != 0) { 1332 dpcpu_free((void *)ef->pcpu_base, 1333 ef->pcpu_stop - ef->pcpu_start); 1334 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1335 } 1336 #ifdef VIMAGE 1337 if (ef->vnet_base != 0) { 1338 vnet_data_free((void *)ef->vnet_base, 1339 ef->vnet_stop - ef->vnet_start); 1340 elf_set_delete(&set_vnet_list, ef->vnet_start); 1341 } 1342 #endif 1343 #ifdef GDB 1344 if (ef->gdb.l_ld != NULL) { 1345 GDB_STATE(RT_DELETE); 1346 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1347 link_elf_delete_gdb(&ef->gdb); 1348 GDB_STATE(RT_CONSISTENT); 1349 } 1350 #endif 1351 1352 /* Notify MD code that a module is being unloaded. */ 1353 elf_cpu_unload_file(file); 1354 1355 if (ef->preloaded) { 1356 link_elf_unload_preload(file); 1357 return; 1358 } 1359 1360 #ifdef SPARSE_MAPPING 1361 if (ef->object != NULL) { 1362 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1363 (vm_offset_t) ef->address 1364 + (ef->object->size << PAGE_SHIFT)); 1365 } 1366 #else 1367 free(ef->address, M_LINKER); 1368 #endif 1369 free(ef->symbase, M_LINKER); 1370 free(ef->strbase, M_LINKER); 1371 free(ef->ctftab, M_LINKER); 1372 free(ef->ctfoff, M_LINKER); 1373 free(ef->typoff, M_LINKER); 1374 } 1375 1376 static void 1377 link_elf_unload_preload(linker_file_t file) 1378 { 1379 1380 if (file->pathname != NULL) 1381 preload_delete_name(file->pathname); 1382 } 1383 1384 static const char * 1385 symbol_name(elf_file_t ef, Elf_Size r_info) 1386 { 1387 const Elf_Sym *ref; 1388 1389 if (ELF_R_SYM(r_info)) { 1390 ref = ef->symtab + ELF_R_SYM(r_info); 1391 return (ef->strtab + ref->st_name); 1392 } 1393 return (NULL); 1394 } 1395 1396 static int 1397 symbol_type(elf_file_t ef, Elf_Size r_info) 1398 { 1399 const Elf_Sym *ref; 1400 1401 if (ELF_R_SYM(r_info)) { 1402 ref = ef->symtab + ELF_R_SYM(r_info); 1403 return (ELF_ST_TYPE(ref->st_info)); 1404 } 1405 return (STT_NOTYPE); 1406 } 1407 1408 static int 1409 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc, 1410 bool ifuncs) 1411 { 1412 const Elf_Rel *rel; 1413 const Elf_Rela *rela; 1414 const char *symname; 1415 1416 #define APPLY_RELOCS(iter, tbl, tblsize, type) do { \ 1417 for ((iter) = (tbl); (iter) != NULL && \ 1418 (iter) < (tbl) + (tblsize) / sizeof(*(iter)); (iter)++) { \ 1419 if ((symbol_type(ef, (iter)->r_info) == \ 1420 STT_GNU_IFUNC || \ 1421 elf_is_ifunc_reloc((iter)->r_info)) != ifuncs) \ 1422 continue; \ 1423 if (reloc(&ef->lf, (Elf_Addr)ef->address, \ 1424 (iter), (type), lookup)) { \ 1425 symname = symbol_name(ef, (iter)->r_info); \ 1426 printf("link_elf: symbol %s undefined\n", \ 1427 symname); \ 1428 return (ENOENT); \ 1429 } \ 1430 } \ 1431 } while (0) 1432 1433 APPLY_RELOCS(rel, ef->rel, ef->relsize, ELF_RELOC_REL); 1434 APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA); 1435 APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL); 1436 APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA); 1437 1438 #undef APPLY_RELOCS 1439 1440 return (0); 1441 } 1442 1443 static int 1444 relocate_file(elf_file_t ef) 1445 { 1446 int error; 1447 1448 error = relocate_file1(ef, elf_lookup, elf_reloc, false); 1449 if (error == 0) 1450 error = relocate_file1(ef, elf_lookup, elf_reloc, true); 1451 return (error); 1452 } 1453 1454 /* 1455 * Hash function for symbol table lookup. Don't even think about changing 1456 * this. It is specified by the System V ABI. 1457 */ 1458 static unsigned long 1459 elf_hash(const char *name) 1460 { 1461 const unsigned char *p = (const unsigned char *) name; 1462 unsigned long h = 0; 1463 unsigned long g; 1464 1465 while (*p != '\0') { 1466 h = (h << 4) + *p++; 1467 if ((g = h & 0xf0000000) != 0) 1468 h ^= g >> 24; 1469 h &= ~g; 1470 } 1471 return (h); 1472 } 1473 1474 static int 1475 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1476 { 1477 elf_file_t ef = (elf_file_t) lf; 1478 unsigned long symnum; 1479 const Elf_Sym* symp; 1480 const char *strp; 1481 unsigned long hash; 1482 int i; 1483 1484 /* If we don't have a hash, bail. */ 1485 if (ef->buckets == NULL || ef->nbuckets == 0) { 1486 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1487 return (ENOENT); 1488 } 1489 1490 /* First, search hashed global symbols */ 1491 hash = elf_hash(name); 1492 symnum = ef->buckets[hash % ef->nbuckets]; 1493 1494 while (symnum != STN_UNDEF) { 1495 if (symnum >= ef->nchains) { 1496 printf("%s: corrupt symbol table\n", __func__); 1497 return (ENOENT); 1498 } 1499 1500 symp = ef->symtab + symnum; 1501 if (symp->st_name == 0) { 1502 printf("%s: corrupt symbol table\n", __func__); 1503 return (ENOENT); 1504 } 1505 1506 strp = ef->strtab + symp->st_name; 1507 1508 if (strcmp(name, strp) == 0) { 1509 if (symp->st_shndx != SHN_UNDEF || 1510 (symp->st_value != 0 && 1511 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1512 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1513 *sym = (c_linker_sym_t) symp; 1514 return (0); 1515 } 1516 return (ENOENT); 1517 } 1518 1519 symnum = ef->chains[symnum]; 1520 } 1521 1522 /* If we have not found it, look at the full table (if loaded) */ 1523 if (ef->symtab == ef->ddbsymtab) 1524 return (ENOENT); 1525 1526 /* Exhaustive search */ 1527 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1528 strp = ef->ddbstrtab + symp->st_name; 1529 if (strcmp(name, strp) == 0) { 1530 if (symp->st_shndx != SHN_UNDEF || 1531 (symp->st_value != 0 && 1532 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1533 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1534 *sym = (c_linker_sym_t) symp; 1535 return (0); 1536 } 1537 return (ENOENT); 1538 } 1539 } 1540 1541 return (ENOENT); 1542 } 1543 1544 static int 1545 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1546 linker_symval_t *symval) 1547 { 1548 elf_file_t ef; 1549 const Elf_Sym *es; 1550 caddr_t val; 1551 1552 ef = (elf_file_t)lf; 1553 es = (const Elf_Sym *)sym; 1554 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1555 symval->name = ef->strtab + es->st_name; 1556 val = (caddr_t)ef->address + es->st_value; 1557 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1558 val = ((caddr_t (*)(void))val)(); 1559 symval->value = val; 1560 symval->size = es->st_size; 1561 return (0); 1562 } 1563 if (ef->symtab == ef->ddbsymtab) 1564 return (ENOENT); 1565 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1566 symval->name = ef->ddbstrtab + es->st_name; 1567 val = (caddr_t)ef->address + es->st_value; 1568 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1569 val = ((caddr_t (*)(void))val)(); 1570 symval->value = val; 1571 symval->size = es->st_size; 1572 return (0); 1573 } 1574 return (ENOENT); 1575 } 1576 1577 static int 1578 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1579 c_linker_sym_t *sym, long *diffp) 1580 { 1581 elf_file_t ef = (elf_file_t) lf; 1582 u_long off = (uintptr_t) (void *) value; 1583 u_long diff = off; 1584 u_long st_value; 1585 const Elf_Sym* es; 1586 const Elf_Sym* best = NULL; 1587 int i; 1588 1589 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1590 if (es->st_name == 0) 1591 continue; 1592 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1593 if (off >= st_value) { 1594 if (off - st_value < diff) { 1595 diff = off - st_value; 1596 best = es; 1597 if (diff == 0) 1598 break; 1599 } else if (off - st_value == diff) { 1600 best = es; 1601 } 1602 } 1603 } 1604 if (best == NULL) 1605 *diffp = off; 1606 else 1607 *diffp = diff; 1608 *sym = (c_linker_sym_t) best; 1609 1610 return (0); 1611 } 1612 1613 /* 1614 * Look up a linker set on an ELF system. 1615 */ 1616 static int 1617 link_elf_lookup_set(linker_file_t lf, const char *name, 1618 void ***startp, void ***stopp, int *countp) 1619 { 1620 c_linker_sym_t sym; 1621 linker_symval_t symval; 1622 char *setsym; 1623 void **start, **stop; 1624 int len, error = 0, count; 1625 1626 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1627 setsym = malloc(len, M_LINKER, M_WAITOK); 1628 1629 /* get address of first entry */ 1630 snprintf(setsym, len, "%s%s", "__start_set_", name); 1631 error = link_elf_lookup_symbol(lf, setsym, &sym); 1632 if (error != 0) 1633 goto out; 1634 link_elf_symbol_values(lf, sym, &symval); 1635 if (symval.value == 0) { 1636 error = ESRCH; 1637 goto out; 1638 } 1639 start = (void **)symval.value; 1640 1641 /* get address of last entry */ 1642 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1643 error = link_elf_lookup_symbol(lf, setsym, &sym); 1644 if (error != 0) 1645 goto out; 1646 link_elf_symbol_values(lf, sym, &symval); 1647 if (symval.value == 0) { 1648 error = ESRCH; 1649 goto out; 1650 } 1651 stop = (void **)symval.value; 1652 1653 /* and the number of entries */ 1654 count = stop - start; 1655 1656 /* and copy out */ 1657 if (startp != NULL) 1658 *startp = start; 1659 if (stopp != NULL) 1660 *stopp = stop; 1661 if (countp != NULL) 1662 *countp = count; 1663 1664 out: 1665 free(setsym, M_LINKER); 1666 return (error); 1667 } 1668 1669 static int 1670 link_elf_each_function_name(linker_file_t file, 1671 int (*callback)(const char *, void *), void *opaque) 1672 { 1673 elf_file_t ef = (elf_file_t)file; 1674 const Elf_Sym *symp; 1675 int i, error; 1676 1677 /* Exhaustive search */ 1678 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1679 if (symp->st_value != 0 && 1680 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1681 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1682 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1683 if (error != 0) 1684 return (error); 1685 } 1686 } 1687 return (0); 1688 } 1689 1690 static int 1691 link_elf_each_function_nameval(linker_file_t file, 1692 linker_function_nameval_callback_t callback, void *opaque) 1693 { 1694 linker_symval_t symval; 1695 elf_file_t ef = (elf_file_t)file; 1696 const Elf_Sym* symp; 1697 int i, error; 1698 1699 /* Exhaustive search */ 1700 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1701 if (symp->st_value != 0 && 1702 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1703 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1704 error = link_elf_symbol_values(file, 1705 (c_linker_sym_t) symp, &symval); 1706 if (error != 0) 1707 return (error); 1708 error = callback(file, i, &symval, opaque); 1709 if (error != 0) 1710 return (error); 1711 } 1712 } 1713 return (0); 1714 } 1715 1716 const Elf_Sym * 1717 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1718 { 1719 elf_file_t ef = (elf_file_t)lf; 1720 1721 if (symidx >= ef->nchains) 1722 return (NULL); 1723 return (ef->symtab + symidx); 1724 } 1725 1726 const char * 1727 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1728 { 1729 elf_file_t ef = (elf_file_t)lf; 1730 const Elf_Sym *sym; 1731 1732 if (symidx >= ef->nchains) 1733 return (NULL); 1734 sym = ef->symtab + symidx; 1735 return (ef->strtab + sym->st_name); 1736 } 1737 1738 /* 1739 * Symbol lookup function that can be used when the symbol index is known (ie 1740 * in relocations). It uses the symbol index instead of doing a fully fledged 1741 * hash table based lookup when such is valid. For example for local symbols. 1742 * This is not only more efficient, it's also more correct. It's not always 1743 * the case that the symbol can be found through the hash table. 1744 */ 1745 static int 1746 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1747 { 1748 elf_file_t ef = (elf_file_t)lf; 1749 const Elf_Sym *sym; 1750 const char *symbol; 1751 Elf_Addr addr, start, base; 1752 1753 /* Don't even try to lookup the symbol if the index is bogus. */ 1754 if (symidx >= ef->nchains) { 1755 *res = 0; 1756 return (EINVAL); 1757 } 1758 1759 sym = ef->symtab + symidx; 1760 1761 /* 1762 * Don't do a full lookup when the symbol is local. It may even 1763 * fail because it may not be found through the hash table. 1764 */ 1765 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1766 /* Force lookup failure when we have an insanity. */ 1767 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) { 1768 *res = 0; 1769 return (EINVAL); 1770 } 1771 *res = ((Elf_Addr)ef->address + sym->st_value); 1772 return (0); 1773 } 1774 1775 /* 1776 * XXX we can avoid doing a hash table based lookup for global 1777 * symbols as well. This however is not always valid, so we'll 1778 * just do it the hard way for now. Performance tweaks can 1779 * always be added. 1780 */ 1781 1782 symbol = ef->strtab + sym->st_name; 1783 1784 /* Force a lookup failure if the symbol name is bogus. */ 1785 if (*symbol == 0) { 1786 *res = 0; 1787 return (EINVAL); 1788 } 1789 1790 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1791 if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1792 *res = 0; 1793 return (EINVAL); 1794 } 1795 1796 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1797 addr = addr - start + base; 1798 #ifdef VIMAGE 1799 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1800 addr = addr - start + base; 1801 #endif 1802 *res = addr; 1803 return (0); 1804 } 1805 1806 static void 1807 link_elf_reloc_local(linker_file_t lf) 1808 { 1809 const Elf_Rel *rellim; 1810 const Elf_Rel *rel; 1811 const Elf_Rela *relalim; 1812 const Elf_Rela *rela; 1813 elf_file_t ef = (elf_file_t)lf; 1814 1815 /* Perform relocations without addend if there are any: */ 1816 if ((rel = ef->rel) != NULL) { 1817 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1818 while (rel < rellim) { 1819 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1820 ELF_RELOC_REL, elf_lookup); 1821 rel++; 1822 } 1823 } 1824 1825 /* Perform relocations with addend if there are any: */ 1826 if ((rela = ef->rela) != NULL) { 1827 relalim = (const Elf_Rela *) 1828 ((const char *)ef->rela + ef->relasize); 1829 while (rela < relalim) { 1830 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1831 ELF_RELOC_RELA, elf_lookup); 1832 rela++; 1833 } 1834 } 1835 } 1836 1837 static long 1838 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1839 { 1840 elf_file_t ef = (elf_file_t)lf; 1841 1842 *symtab = ef->ddbsymtab; 1843 1844 if (*symtab == NULL) 1845 return (0); 1846 1847 return (ef->ddbsymcnt); 1848 } 1849 1850 static long 1851 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1852 { 1853 elf_file_t ef = (elf_file_t)lf; 1854 1855 *strtab = ef->ddbstrtab; 1856 1857 if (*strtab == NULL) 1858 return (0); 1859 1860 return (ef->ddbstrcnt); 1861 } 1862 1863 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) 1864 /* 1865 * Use this lookup routine when performing relocations early during boot. 1866 * The generic lookup routine depends on kobj, which is not initialized 1867 * at that point. 1868 */ 1869 static int 1870 elf_lookup_ifunc(linker_file_t lf, Elf_Size symidx, int deps __unused, 1871 Elf_Addr *res) 1872 { 1873 elf_file_t ef; 1874 const Elf_Sym *symp; 1875 caddr_t val; 1876 1877 ef = (elf_file_t)lf; 1878 symp = ef->symtab + symidx; 1879 if (ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC) { 1880 val = (caddr_t)ef->address + symp->st_value; 1881 *res = ((Elf_Addr (*)(void))val)(); 1882 return (0); 1883 } 1884 return (ENOENT); 1885 } 1886 1887 void 1888 link_elf_ireloc(caddr_t kmdp) 1889 { 1890 struct elf_file eff; 1891 elf_file_t ef; 1892 1893 ef = &eff; 1894 1895 bzero_early(ef, sizeof(*ef)); 1896 1897 ef->modptr = kmdp; 1898 ef->dynamic = (Elf_Dyn *)&_DYNAMIC; 1899 parse_dynamic(ef); 1900 ef->address = 0; 1901 link_elf_preload_parse_symbols(ef); 1902 relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true); 1903 } 1904 #endif 1905