1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 "opt_ddb.h" 30 #include "opt_gdb.h" 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/malloc.h> 37 #ifdef SPARSE_MAPPING 38 #include <sys/mman.h> 39 #endif 40 #include <sys/mutex.h> 41 #include <sys/mount.h> 42 #include <sys/pcpu.h> 43 #include <sys/proc.h> 44 #include <sys/namei.h> 45 #include <sys/fcntl.h> 46 #include <sys/vnode.h> 47 #include <sys/linker.h> 48 #include <sys/sysctl.h> 49 #include <sys/tslog.h> 50 51 #include <machine/elf.h> 52 53 #include <net/vnet.h> 54 55 #include <security/mac/mac_framework.h> 56 57 #include <vm/vm.h> 58 #include <vm/vm_param.h> 59 #ifdef SPARSE_MAPPING 60 #include <vm/vm_object.h> 61 #include <vm/vm_kern.h> 62 #include <vm/vm_extern.h> 63 #endif 64 #include <vm/pmap.h> 65 #include <vm/vm_map.h> 66 67 #include <sys/link_elf.h> 68 69 #include "linker_if.h" 70 71 #ifdef DDB_CTF 72 #include <ddb/db_ctf.h> 73 #endif 74 75 #define MAXSEGS 4 76 77 typedef struct elf_file { 78 struct linker_file lf; /* Common fields */ 79 int preloaded; /* Was file pre-loaded */ 80 caddr_t address; /* Relocation address */ 81 #ifdef SPARSE_MAPPING 82 vm_object_t object; /* VM object to hold file pages */ 83 #endif 84 Elf_Dyn *dynamic; /* Symbol table etc. */ 85 Elf_Hashelt nbuckets; /* DT_HASH info */ 86 Elf_Hashelt nchains; 87 const Elf_Hashelt *buckets; 88 const Elf_Hashelt *chains; 89 caddr_t hash; 90 caddr_t strtab; /* DT_STRTAB */ 91 int strsz; /* DT_STRSZ */ 92 const Elf_Sym *symtab; /* DT_SYMTAB */ 93 Elf_Addr *got; /* DT_PLTGOT */ 94 const Elf_Rel *pltrel; /* DT_JMPREL */ 95 int pltrelsize; /* DT_PLTRELSZ */ 96 const Elf_Rela *pltrela; /* DT_JMPREL */ 97 int pltrelasize; /* DT_PLTRELSZ */ 98 const Elf_Rel *rel; /* DT_REL */ 99 int relsize; /* DT_RELSZ */ 100 const Elf_Rela *rela; /* DT_RELA */ 101 int relasize; /* DT_RELASZ */ 102 caddr_t modptr; 103 const Elf_Sym *ddbsymtab; /* The symbol table we are using */ 104 long ddbsymcnt; /* Number of symbols */ 105 caddr_t ddbstrtab; /* String table */ 106 long ddbstrcnt; /* number of bytes in string table */ 107 caddr_t symbase; /* malloc'ed symbold base */ 108 caddr_t strbase; /* malloc'ed string base */ 109 caddr_t ctftab; /* CTF table */ 110 long ctfcnt; /* number of bytes in CTF table */ 111 caddr_t ctfoff; /* CTF offset table */ 112 caddr_t typoff; /* Type offset table */ 113 long typlen; /* Number of type entries. */ 114 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */ 115 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */ 116 Elf_Addr pcpu_base; /* Relocated pcpu set address. */ 117 #ifdef VIMAGE 118 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */ 119 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */ 120 Elf_Addr vnet_base; /* Relocated vnet set address. */ 121 #endif 122 #ifdef GDB 123 struct link_map gdb; /* hooks for gdb */ 124 #endif 125 } *elf_file_t; 126 127 struct elf_set { 128 Elf_Addr es_start; 129 Elf_Addr es_stop; 130 Elf_Addr es_base; 131 TAILQ_ENTRY(elf_set) es_link; 132 }; 133 134 TAILQ_HEAD(elf_set_head, elf_set); 135 136 #include <kern/kern_ctf.c> 137 138 static int link_elf_link_common_finish(linker_file_t); 139 static int link_elf_link_preload(linker_class_t cls, 140 const char *, linker_file_t *); 141 static int link_elf_link_preload_finish(linker_file_t); 142 static int link_elf_load_file(linker_class_t, const char *, 143 linker_file_t *); 144 static int link_elf_lookup_symbol(linker_file_t, const char *, 145 c_linker_sym_t *); 146 static int link_elf_lookup_debug_symbol(linker_file_t, const char *, 147 c_linker_sym_t *); 148 static int link_elf_lookup_debug_symbol_ctf(linker_file_t lf, 149 const char *name, c_linker_sym_t *sym, linker_ctf_t *lc); 150 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 151 linker_symval_t *); 152 static int link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t, 153 linker_symval_t*); 154 static int link_elf_search_symbol(linker_file_t, caddr_t, 155 c_linker_sym_t *, long *); 156 157 static void link_elf_unload_file(linker_file_t); 158 static void link_elf_unload_preload(linker_file_t); 159 static int link_elf_lookup_set(linker_file_t, const char *, 160 void ***, void ***, int *); 161 static int link_elf_each_function_name(linker_file_t, 162 int (*)(const char *, void *), void *); 163 static int link_elf_each_function_nameval(linker_file_t, 164 linker_function_nameval_callback_t, void *); 165 static void link_elf_reloc_local(linker_file_t); 166 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 167 static long link_elf_strtab_get(linker_file_t, caddr_t *); 168 #ifdef VIMAGE 169 static void link_elf_propagate_vnets(linker_file_t); 170 #endif 171 static int elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *); 172 173 static kobj_method_t link_elf_methods[] = { 174 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 175 KOBJMETHOD(linker_lookup_debug_symbol, link_elf_lookup_debug_symbol), 176 KOBJMETHOD(linker_lookup_debug_symbol_ctf, link_elf_lookup_debug_symbol_ctf), 177 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 178 KOBJMETHOD(linker_debug_symbol_values, link_elf_debug_symbol_values), 179 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 180 KOBJMETHOD(linker_unload, link_elf_unload_file), 181 KOBJMETHOD(linker_load_file, link_elf_load_file), 182 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 183 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 184 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 185 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 186 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 187 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 188 KOBJMETHOD(linker_ctf_lookup_typename, link_elf_ctf_lookup_typename), 189 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 190 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 191 #ifdef VIMAGE 192 KOBJMETHOD(linker_propagate_vnets, link_elf_propagate_vnets), 193 #endif 194 KOBJMETHOD_END 195 }; 196 197 static struct linker_class link_elf_class = { 198 #if ELF_TARG_CLASS == ELFCLASS32 199 "elf32", 200 #else 201 "elf64", 202 #endif 203 link_elf_methods, sizeof(struct elf_file) 204 }; 205 206 static bool link_elf_leak_locals = true; 207 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_leak_locals, 208 CTLFLAG_RWTUN, &link_elf_leak_locals, 0, 209 "Allow local symbols to participate in global module symbol resolution"); 210 211 typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase, 212 const void *data, int type, elf_lookup_fn lookup); 213 214 static int parse_dynamic(elf_file_t); 215 static int relocate_file(elf_file_t); 216 static int relocate_file1(elf_file_t ef, elf_lookup_fn lookup, 217 elf_reloc_fn reloc, bool ifuncs); 218 static int link_elf_preload_parse_symbols(elf_file_t); 219 220 static struct elf_set_head set_pcpu_list; 221 #ifdef VIMAGE 222 static struct elf_set_head set_vnet_list; 223 #endif 224 225 static void 226 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base) 227 { 228 struct elf_set *set, *iter; 229 230 set = malloc(sizeof(*set), M_LINKER, M_WAITOK); 231 set->es_start = start; 232 set->es_stop = stop; 233 set->es_base = base; 234 235 TAILQ_FOREACH(iter, list, es_link) { 236 KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) || 237 (set->es_start > iter->es_start && set->es_stop > iter->es_stop), 238 ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx", 239 (uintmax_t)set->es_start, (uintmax_t)set->es_stop, 240 (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop)); 241 242 if (iter->es_start > set->es_start) { 243 TAILQ_INSERT_BEFORE(iter, set, es_link); 244 break; 245 } 246 } 247 248 if (iter == NULL) 249 TAILQ_INSERT_TAIL(list, set, es_link); 250 } 251 252 static int 253 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base) 254 { 255 struct elf_set *set; 256 257 TAILQ_FOREACH(set, list, es_link) { 258 if (addr < set->es_start) 259 return (0); 260 if (addr < set->es_stop) { 261 *start = set->es_start; 262 *base = set->es_base; 263 return (1); 264 } 265 } 266 267 return (0); 268 } 269 270 static void 271 elf_set_delete(struct elf_set_head *list, Elf_Addr start) 272 { 273 struct elf_set *set; 274 275 TAILQ_FOREACH(set, list, es_link) { 276 if (start < set->es_start) 277 break; 278 if (start == set->es_start) { 279 TAILQ_REMOVE(list, set, es_link); 280 free(set, M_LINKER); 281 return; 282 } 283 } 284 KASSERT(0, ("deleting unknown linker set (start = 0x%jx)", 285 (uintmax_t)start)); 286 } 287 288 #ifdef GDB 289 static void r_debug_state(struct r_debug *, struct link_map *); 290 291 /* 292 * A list of loaded modules for GDB to use for loading symbols. 293 */ 294 struct r_debug r_debug; 295 296 #define GDB_STATE(s) do { \ 297 r_debug.r_state = s; r_debug_state(NULL, NULL); \ 298 } while (0) 299 300 /* 301 * Function for the debugger to set a breakpoint on to gain control. 302 */ 303 static void 304 r_debug_state(struct r_debug *dummy_one __unused, 305 struct link_map *dummy_two __unused) 306 { 307 } 308 309 static void 310 link_elf_add_gdb(struct link_map *l) 311 { 312 struct link_map *prev; 313 314 l->l_next = NULL; 315 316 if (r_debug.r_map == NULL) { 317 /* Add first. */ 318 l->l_prev = NULL; 319 r_debug.r_map = l; 320 } else { 321 /* Append to list. */ 322 for (prev = r_debug.r_map; 323 prev->l_next != NULL; 324 prev = prev->l_next) 325 ; 326 l->l_prev = prev; 327 prev->l_next = l; 328 } 329 } 330 331 static void 332 link_elf_delete_gdb(struct link_map *l) 333 { 334 if (l->l_prev == NULL) { 335 /* Remove first. */ 336 if ((r_debug.r_map = l->l_next) != NULL) 337 l->l_next->l_prev = NULL; 338 } else { 339 /* Remove any but first. */ 340 if ((l->l_prev->l_next = l->l_next) != NULL) 341 l->l_next->l_prev = l->l_prev; 342 } 343 } 344 #endif /* GDB */ 345 346 /* 347 * The kernel symbol table starts here. 348 */ 349 extern struct _dynamic _DYNAMIC; 350 351 static void 352 link_elf_error(const char *filename, const char *s) 353 { 354 if (filename == NULL) 355 printf("kldload: %s\n", s); 356 else 357 printf("kldload: %s: %s\n", filename, s); 358 } 359 360 static void 361 link_elf_invoke_cbs(caddr_t addr, size_t size) 362 { 363 void (**ctor)(void); 364 size_t i, cnt; 365 366 if (addr == NULL || size == 0) 367 return; 368 cnt = size / sizeof(*ctor); 369 ctor = (void *)addr; 370 for (i = 0; i < cnt; i++) { 371 if (ctor[i] != NULL) 372 (*ctor[i])(); 373 } 374 } 375 376 static void 377 link_elf_invoke_ctors(linker_file_t lf) 378 { 379 KASSERT(lf->ctors_invoked == LF_NONE, 380 ("%s: file %s ctor state %d", 381 __func__, lf->filename, lf->ctors_invoked)); 382 383 link_elf_invoke_cbs(lf->ctors_addr, lf->ctors_size); 384 lf->ctors_invoked = LF_CTORS; 385 } 386 387 /* 388 * Actions performed after linking/loading both the preloaded kernel and any 389 * modules; whether preloaded or dynamicly loaded. 390 */ 391 static int 392 link_elf_link_common_finish(linker_file_t lf) 393 { 394 #ifdef GDB 395 elf_file_t ef = (elf_file_t)lf; 396 char *newfilename; 397 #endif 398 int error; 399 400 /* Notify MD code that a module is being loaded. */ 401 error = elf_cpu_load_file(lf); 402 if (error != 0) 403 return (error); 404 405 #ifdef GDB 406 GDB_STATE(RT_ADD); 407 ef->gdb.l_addr = lf->address; 408 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 409 strcpy(newfilename, lf->filename); 410 ef->gdb.l_name = newfilename; 411 ef->gdb.l_ld = ef->dynamic; 412 link_elf_add_gdb(&ef->gdb); 413 GDB_STATE(RT_CONSISTENT); 414 #endif 415 416 /* Invoke .ctors */ 417 link_elf_invoke_ctors(lf); 418 return (0); 419 } 420 421 #ifdef RELOCATABLE_KERNEL 422 /* 423 * __startkernel and __endkernel are symbols set up as relocation canaries. 424 * 425 * They are defined in locore to reference linker script symbols at the 426 * beginning and end of the LOAD area. This has the desired side effect of 427 * giving us variables that have relative relocations pointing at them, so 428 * relocation of the kernel object will cause the variables to be updated 429 * automatically by the runtime linker when we initialize. 430 * 431 * There are two main reasons to relocate the kernel: 432 * 1) If the loader needed to load the kernel at an alternate load address. 433 * 2) If the kernel is switching address spaces on machines like POWER9 434 * under Radix where the high bits of the effective address are used to 435 * differentiate between hypervisor, host, guest, and problem state. 436 */ 437 extern vm_offset_t __startkernel, __endkernel; 438 #endif 439 440 static unsigned long kern_relbase = KERNBASE; 441 442 SYSCTL_ULONG(_kern, OID_AUTO, base_address, CTLFLAG_RD, 443 SYSCTL_NULL_ULONG_PTR, KERNBASE, "Kernel base address"); 444 SYSCTL_ULONG(_kern, OID_AUTO, relbase_address, CTLFLAG_RD, 445 &kern_relbase, 0, "Kernel relocated base address"); 446 447 static void 448 link_elf_init(void* arg) 449 { 450 Elf_Dyn *dp; 451 Elf_Addr *ctors_addrp; 452 Elf_Size *ctors_sizep; 453 caddr_t modptr, baseptr, sizeptr; 454 elf_file_t ef; 455 const char *modname; 456 457 linker_add_class(&link_elf_class); 458 459 dp = (Elf_Dyn *)&_DYNAMIC; 460 modname = NULL; 461 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 462 if (modptr == NULL) 463 modptr = preload_search_by_type("elf kernel"); 464 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 465 if (modname == NULL) 466 modname = "kernel"; 467 linker_kernel_file = linker_make_file(modname, &link_elf_class); 468 if (linker_kernel_file == NULL) 469 panic("%s: Can't create linker structures for kernel", 470 __func__); 471 472 ef = (elf_file_t) linker_kernel_file; 473 ef->preloaded = 1; 474 #ifdef RELOCATABLE_KERNEL 475 /* Compute relative displacement */ 476 ef->address = (caddr_t) (__startkernel - KERNBASE); 477 #else 478 ef->address = 0; 479 #endif 480 #ifdef SPARSE_MAPPING 481 ef->object = NULL; 482 #endif 483 ef->dynamic = dp; 484 485 if (dp != NULL) 486 parse_dynamic(ef); 487 #ifdef RELOCATABLE_KERNEL 488 linker_kernel_file->address = (caddr_t)__startkernel; 489 linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel); 490 kern_relbase = (unsigned long)__startkernel; 491 #else 492 linker_kernel_file->address += KERNBASE; 493 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 494 #endif 495 496 if (modptr != NULL) { 497 ef->modptr = modptr; 498 baseptr = preload_search_info(modptr, MODINFO_ADDR); 499 if (baseptr != NULL) 500 linker_kernel_file->address = *(caddr_t *)baseptr; 501 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 502 if (sizeptr != NULL) 503 linker_kernel_file->size = *(size_t *)sizeptr; 504 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 505 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 506 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 507 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 508 if (ctors_addrp != NULL && ctors_sizep != NULL) { 509 linker_kernel_file->ctors_addr = ef->address + 510 *ctors_addrp; 511 linker_kernel_file->ctors_size = *ctors_sizep; 512 } 513 } 514 (void)link_elf_preload_parse_symbols(ef); 515 516 #ifdef GDB 517 r_debug.r_map = NULL; 518 r_debug.r_brk = r_debug_state; 519 r_debug.r_state = RT_CONSISTENT; 520 #endif 521 522 (void)link_elf_link_common_finish(linker_kernel_file); 523 linker_kernel_file->flags |= LINKER_FILE_LINKED; 524 TAILQ_INIT(&set_pcpu_list); 525 #ifdef VIMAGE 526 TAILQ_INIT(&set_vnet_list); 527 vnet_save_init((void *)VNET_START, VNET_STOP - VNET_START); 528 #endif 529 } 530 531 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL); 532 533 static int 534 link_elf_preload_parse_symbols(elf_file_t ef) 535 { 536 caddr_t pointer; 537 caddr_t ssym, esym, base; 538 caddr_t strtab; 539 int strcnt; 540 Elf_Sym *symtab; 541 int symcnt; 542 543 if (ef->modptr == NULL) 544 return (0); 545 pointer = preload_search_info(ef->modptr, 546 MODINFO_METADATA | MODINFOMD_SSYM); 547 if (pointer == NULL) 548 return (0); 549 ssym = *(caddr_t *)pointer; 550 pointer = preload_search_info(ef->modptr, 551 MODINFO_METADATA | MODINFOMD_ESYM); 552 if (pointer == NULL) 553 return (0); 554 esym = *(caddr_t *)pointer; 555 556 base = ssym; 557 558 symcnt = *(long *)base; 559 base += sizeof(long); 560 symtab = (Elf_Sym *)base; 561 base += roundup(symcnt, sizeof(long)); 562 563 if (base > esym || base < ssym) { 564 printf("Symbols are corrupt!\n"); 565 return (EINVAL); 566 } 567 568 strcnt = *(long *)base; 569 base += sizeof(long); 570 strtab = base; 571 base += roundup(strcnt, sizeof(long)); 572 573 if (base > esym || base < ssym) { 574 printf("Symbols are corrupt!\n"); 575 return (EINVAL); 576 } 577 578 ef->ddbsymtab = symtab; 579 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 580 ef->ddbstrtab = strtab; 581 ef->ddbstrcnt = strcnt; 582 583 return (0); 584 } 585 586 static int 587 parse_dynamic(elf_file_t ef) 588 { 589 Elf_Dyn *dp; 590 int plttype = DT_REL; 591 592 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 593 switch (dp->d_tag) { 594 case DT_HASH: 595 { 596 /* From src/libexec/rtld-elf/rtld.c */ 597 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 598 (ef->address + dp->d_un.d_ptr); 599 ef->nbuckets = hashtab[0]; 600 ef->nchains = hashtab[1]; 601 ef->buckets = hashtab + 2; 602 ef->chains = ef->buckets + ef->nbuckets; 603 break; 604 } 605 case DT_STRTAB: 606 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 607 break; 608 case DT_STRSZ: 609 ef->strsz = dp->d_un.d_val; 610 break; 611 case DT_SYMTAB: 612 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 613 break; 614 case DT_SYMENT: 615 if (dp->d_un.d_val != sizeof(Elf_Sym)) 616 return (ENOEXEC); 617 break; 618 case DT_PLTGOT: 619 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 620 break; 621 case DT_REL: 622 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 623 break; 624 case DT_RELSZ: 625 ef->relsize = dp->d_un.d_val; 626 break; 627 case DT_RELENT: 628 if (dp->d_un.d_val != sizeof(Elf_Rel)) 629 return (ENOEXEC); 630 break; 631 case DT_JMPREL: 632 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 633 break; 634 case DT_PLTRELSZ: 635 ef->pltrelsize = dp->d_un.d_val; 636 break; 637 case DT_RELA: 638 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 639 break; 640 case DT_RELASZ: 641 ef->relasize = dp->d_un.d_val; 642 break; 643 case DT_RELAENT: 644 if (dp->d_un.d_val != sizeof(Elf_Rela)) 645 return (ENOEXEC); 646 break; 647 case DT_PLTREL: 648 plttype = dp->d_un.d_val; 649 if (plttype != DT_REL && plttype != DT_RELA) 650 return (ENOEXEC); 651 break; 652 #ifdef GDB 653 case DT_DEBUG: 654 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 655 break; 656 #endif 657 } 658 } 659 660 if (plttype == DT_RELA) { 661 ef->pltrela = (const Elf_Rela *)ef->pltrel; 662 ef->pltrel = NULL; 663 ef->pltrelasize = ef->pltrelsize; 664 ef->pltrelsize = 0; 665 } 666 667 ef->ddbsymtab = ef->symtab; 668 ef->ddbsymcnt = ef->nchains; 669 ef->ddbstrtab = ef->strtab; 670 ef->ddbstrcnt = ef->strsz; 671 672 return elf_cpu_parse_dynamic(ef->address, ef->dynamic); 673 } 674 675 #define LS_PADDING 0x90909090 676 static int 677 parse_dpcpu(elf_file_t ef) 678 { 679 int error, size; 680 #if defined(__i386__) 681 uint32_t pad; 682 #endif 683 684 ef->pcpu_start = 0; 685 ef->pcpu_stop = 0; 686 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 687 (void ***)&ef->pcpu_stop, NULL); 688 /* Error just means there is no pcpu set to relocate. */ 689 if (error != 0) 690 return (0); 691 size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start; 692 /* Empty set? */ 693 if (size < 1) 694 return (0); 695 #if defined(__i386__) 696 /* In case we do find __start/stop_set_ symbols double-check. */ 697 if (size < 4) { 698 uprintf("Kernel module '%s' must be recompiled with " 699 "linker script\n", ef->lf.pathname); 700 return (ENOEXEC); 701 } 702 703 /* Padding from linker-script correct? */ 704 pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad)); 705 if (pad != LS_PADDING) { 706 uprintf("Kernel module '%s' must be recompiled with " 707 "linker script, invalid padding %#04x (%#04x)\n", 708 ef->lf.pathname, pad, LS_PADDING); 709 return (ENOEXEC); 710 } 711 /* If we only have valid padding, nothing to do. */ 712 if (size == 4) 713 return (0); 714 #endif 715 /* 716 * Allocate space in the primary pcpu area. Copy in our 717 * initialization from the data section and then initialize 718 * all per-cpu storage from that. 719 */ 720 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size); 721 if (ef->pcpu_base == 0) { 722 printf("%s: pcpu module space is out of space; " 723 "cannot allocate %d for %s\n", 724 __func__, size, ef->lf.pathname); 725 return (ENOSPC); 726 } 727 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size); 728 dpcpu_copy((void *)ef->pcpu_base, size); 729 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 730 ef->pcpu_base); 731 732 return (0); 733 } 734 735 #ifdef VIMAGE 736 static int 737 parse_vnet(elf_file_t ef) 738 { 739 int error, size; 740 #if defined(__i386__) 741 uint32_t pad; 742 #endif 743 744 ef->vnet_start = 0; 745 ef->vnet_stop = 0; 746 ef->vnet_base = 0; 747 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 748 (void ***)&ef->vnet_stop, NULL); 749 /* Error just means there is no vnet data set to relocate. */ 750 if (error != 0) 751 return (0); 752 size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start; 753 /* Empty set? */ 754 if (size < 1) 755 return (0); 756 #if defined(__i386__) 757 /* In case we do find __start/stop_set_ symbols double-check. */ 758 if (size < 4) { 759 uprintf("Kernel module '%s' must be recompiled with " 760 "linker script\n", ef->lf.pathname); 761 return (ENOEXEC); 762 } 763 764 /* Padding from linker-script correct? */ 765 pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad)); 766 if (pad != LS_PADDING) { 767 uprintf("Kernel module '%s' must be recompiled with " 768 "linker script, invalid padding %#04x (%#04x)\n", 769 ef->lf.pathname, pad, LS_PADDING); 770 return (ENOEXEC); 771 } 772 /* If we only have valid padding, nothing to do. */ 773 if (size == 4) 774 return (0); 775 #endif 776 /* 777 * Allocate space in the primary vnet area. Copy in our 778 * initialization from the data section and then initialize 779 * all per-vnet storage from that. 780 */ 781 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size); 782 if (ef->vnet_base == 0) { 783 printf("%s: vnet module space is out of space; " 784 "cannot allocate %d for %s\n", 785 __func__, size, ef->lf.pathname); 786 return (ENOSPC); 787 } 788 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size); 789 vnet_save_init((void *)ef->vnet_base, size); 790 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 791 ef->vnet_base); 792 793 return (0); 794 } 795 #endif 796 #undef LS_PADDING 797 798 /* 799 * Apply the specified protection to the loadable segments of a preloaded linker 800 * file. 801 */ 802 static int 803 preload_protect(elf_file_t ef, vm_prot_t prot) 804 { 805 #if defined(__aarch64__) || defined(__amd64__) 806 Elf_Ehdr *hdr; 807 Elf_Phdr *phdr, *phlimit; 808 vm_prot_t nprot; 809 int error; 810 811 error = 0; 812 hdr = (Elf_Ehdr *)ef->address; 813 phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff); 814 phlimit = phdr + hdr->e_phnum; 815 for (; phdr < phlimit; phdr++) { 816 if (phdr->p_type != PT_LOAD) 817 continue; 818 819 nprot = prot | VM_PROT_READ; 820 if ((phdr->p_flags & PF_W) != 0) 821 nprot |= VM_PROT_WRITE; 822 if ((phdr->p_flags & PF_X) != 0) 823 nprot |= VM_PROT_EXECUTE; 824 error = pmap_change_prot((vm_offset_t)ef->address + 825 phdr->p_vaddr, round_page(phdr->p_memsz), nprot); 826 if (error != 0) 827 break; 828 } 829 return (error); 830 #else 831 return (0); 832 #endif 833 } 834 835 #ifdef __arm__ 836 /* 837 * Locate the ARM exception/unwind table info for DDB and stack(9) use by 838 * searching for the section header that describes it. There may be no unwind 839 * info, for example in a module containing only data. 840 */ 841 static void 842 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr) 843 { 844 int i; 845 846 for (i = 0; i < nhdr; i++) { 847 if (shdr[i].sh_type == SHT_ARM_EXIDX) { 848 lf->exidx_addr = shdr[i].sh_addr + lf->address; 849 lf->exidx_size = shdr[i].sh_size; 850 break; 851 } 852 } 853 } 854 855 /* 856 * Locate the section headers metadata in a preloaded module, then use it to 857 * locate the exception/unwind table in the module. The size of the metadata 858 * block is stored in a uint32 word immediately before the data itself, and a 859 * comment in preload_search_info() says it is safe to rely on that. 860 */ 861 static void 862 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr) 863 { 864 uint32_t *modinfo; 865 Elf_Shdr *shdr; 866 uint32_t nhdr; 867 868 modinfo = (uint32_t *)preload_search_info(modptr, 869 MODINFO_METADATA | MODINFOMD_SHDR); 870 if (modinfo != NULL) { 871 shdr = (Elf_Shdr *)modinfo; 872 nhdr = modinfo[-1] / sizeof(Elf_Shdr); 873 link_elf_locate_exidx(lf, shdr, nhdr); 874 } 875 } 876 877 #endif /* __arm__ */ 878 879 static int 880 link_elf_link_preload(linker_class_t cls, const char *filename, 881 linker_file_t *result) 882 { 883 Elf_Addr *ctors_addrp; 884 Elf_Size *ctors_sizep; 885 caddr_t modptr, baseptr, sizeptr, dynptr; 886 char *type; 887 elf_file_t ef; 888 linker_file_t lf; 889 int error; 890 vm_offset_t dp; 891 892 /* Look to see if we have the file preloaded */ 893 modptr = preload_search_by_name(filename); 894 if (modptr == NULL) 895 return (ENOENT); 896 897 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 898 baseptr = preload_search_info(modptr, MODINFO_ADDR); 899 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 900 dynptr = preload_search_info(modptr, 901 MODINFO_METADATA | MODINFOMD_DYNAMIC); 902 if (type == NULL || 903 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 904 strcmp(type, "elf module") != 0)) 905 return (EFTYPE); 906 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 907 return (EINVAL); 908 909 lf = linker_make_file(filename, &link_elf_class); 910 if (lf == NULL) 911 return (ENOMEM); 912 913 ef = (elf_file_t) lf; 914 ef->preloaded = 1; 915 ef->modptr = modptr; 916 ef->address = *(caddr_t *)baseptr; 917 #ifdef SPARSE_MAPPING 918 ef->object = NULL; 919 #endif 920 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 921 ef->dynamic = (Elf_Dyn *)dp; 922 lf->address = ef->address; 923 lf->size = *(size_t *)sizeptr; 924 925 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 926 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 927 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 928 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 929 if (ctors_addrp != NULL && ctors_sizep != NULL) { 930 lf->ctors_addr = ef->address + *ctors_addrp; 931 lf->ctors_size = *ctors_sizep; 932 } 933 934 #ifdef __arm__ 935 link_elf_locate_exidx_preload(lf, modptr); 936 #endif 937 938 error = parse_dynamic(ef); 939 if (error == 0) 940 error = parse_dpcpu(ef); 941 #ifdef VIMAGE 942 if (error == 0) 943 error = parse_vnet(ef); 944 #endif 945 if (error == 0) 946 error = preload_protect(ef, VM_PROT_ALL); 947 if (error != 0) { 948 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 949 return (error); 950 } 951 link_elf_reloc_local(lf); 952 *result = lf; 953 return (0); 954 } 955 956 static int 957 link_elf_link_preload_finish(linker_file_t lf) 958 { 959 elf_file_t ef; 960 int error; 961 962 ef = (elf_file_t) lf; 963 error = relocate_file(ef); 964 if (error == 0) 965 error = preload_protect(ef, VM_PROT_NONE); 966 if (error != 0) 967 return (error); 968 (void)link_elf_preload_parse_symbols(ef); 969 970 return (link_elf_link_common_finish(lf)); 971 } 972 973 static int 974 link_elf_load_file(linker_class_t cls, const char* filename, 975 linker_file_t* result) 976 { 977 struct nameidata nd; 978 struct thread* td = curthread; /* XXX */ 979 Elf_Ehdr *hdr; 980 caddr_t firstpage, segbase; 981 int nbytes, i; 982 Elf_Phdr *phdr; 983 Elf_Phdr *phlimit; 984 Elf_Phdr *segs[MAXSEGS]; 985 int nsegs; 986 Elf_Phdr *phdyn; 987 caddr_t mapbase; 988 size_t mapsize; 989 Elf_Addr base_vaddr; 990 Elf_Addr base_vlimit; 991 int error = 0; 992 ssize_t resid; 993 int flags; 994 elf_file_t ef; 995 linker_file_t lf; 996 Elf_Shdr *shdr; 997 int symtabindex; 998 int symstrindex; 999 int shstrindex; 1000 int symcnt; 1001 int strcnt; 1002 char *shstrs; 1003 1004 shdr = NULL; 1005 lf = NULL; 1006 shstrs = NULL; 1007 1008 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename); 1009 flags = FREAD; 1010 error = vn_open(&nd, &flags, 0, NULL); 1011 if (error != 0) 1012 return (error); 1013 NDFREE_PNBUF(&nd); 1014 if (nd.ni_vp->v_type != VREG) { 1015 error = ENOEXEC; 1016 firstpage = NULL; 1017 goto out; 1018 } 1019 #ifdef MAC 1020 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 1021 if (error != 0) { 1022 firstpage = NULL; 1023 goto out; 1024 } 1025 #endif 1026 1027 /* 1028 * Read the elf header from the file. 1029 */ 1030 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 1031 hdr = (Elf_Ehdr *)firstpage; 1032 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 1033 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1034 &resid, td); 1035 nbytes = PAGE_SIZE - resid; 1036 if (error != 0) 1037 goto out; 1038 1039 if (!IS_ELF(*hdr)) { 1040 error = ENOEXEC; 1041 goto out; 1042 } 1043 1044 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 1045 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 1046 link_elf_error(filename, "Unsupported file layout"); 1047 error = ENOEXEC; 1048 goto out; 1049 } 1050 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 1051 hdr->e_version != EV_CURRENT) { 1052 link_elf_error(filename, "Unsupported file version"); 1053 error = ENOEXEC; 1054 goto out; 1055 } 1056 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 1057 error = ENOSYS; 1058 goto out; 1059 } 1060 if (hdr->e_machine != ELF_TARG_MACH) { 1061 link_elf_error(filename, "Unsupported machine"); 1062 error = ENOEXEC; 1063 goto out; 1064 } 1065 1066 /* 1067 * We rely on the program header being in the first page. 1068 * This is not strictly required by the ABI specification, but 1069 * it seems to always true in practice. And, it simplifies 1070 * things considerably. 1071 */ 1072 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 1073 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 1074 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 1075 link_elf_error(filename, "Unreadable program headers"); 1076 1077 /* 1078 * Scan the program header entries, and save key information. 1079 * 1080 * We rely on there being exactly two load segments, text and data, 1081 * in that order. 1082 */ 1083 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 1084 phlimit = phdr + hdr->e_phnum; 1085 nsegs = 0; 1086 phdyn = NULL; 1087 while (phdr < phlimit) { 1088 switch (phdr->p_type) { 1089 case PT_LOAD: 1090 if (nsegs == MAXSEGS) { 1091 link_elf_error(filename, "Too many sections"); 1092 error = ENOEXEC; 1093 goto out; 1094 } 1095 /* 1096 * XXX: We just trust they come in right order ?? 1097 */ 1098 segs[nsegs] = phdr; 1099 ++nsegs; 1100 break; 1101 1102 case PT_DYNAMIC: 1103 phdyn = phdr; 1104 break; 1105 1106 case PT_INTERP: 1107 error = ENOSYS; 1108 goto out; 1109 } 1110 1111 ++phdr; 1112 } 1113 if (phdyn == NULL) { 1114 link_elf_error(filename, "Object is not dynamically-linked"); 1115 error = ENOEXEC; 1116 goto out; 1117 } 1118 if (nsegs == 0) { 1119 link_elf_error(filename, "No sections"); 1120 error = ENOEXEC; 1121 goto out; 1122 } 1123 1124 /* 1125 * Allocate the entire address space of the object, to stake 1126 * out our contiguous region, and to establish the base 1127 * address for relocation. 1128 */ 1129 base_vaddr = trunc_page(segs[0]->p_vaddr); 1130 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 1131 segs[nsegs - 1]->p_memsz); 1132 mapsize = base_vlimit - base_vaddr; 1133 1134 lf = linker_make_file(filename, &link_elf_class); 1135 if (lf == NULL) { 1136 error = ENOMEM; 1137 goto out; 1138 } 1139 1140 ef = (elf_file_t) lf; 1141 #ifdef SPARSE_MAPPING 1142 ef->object = vm_pager_allocate(OBJT_PHYS, NULL, mapsize, VM_PROT_ALL, 1143 0, thread0.td_ucred); 1144 if (ef->object == NULL) { 1145 error = ENOMEM; 1146 goto out; 1147 } 1148 #ifdef __amd64__ 1149 mapbase = (caddr_t)KERNBASE; 1150 #else 1151 mapbase = (caddr_t)vm_map_min(kernel_map); 1152 #endif 1153 /* 1154 * Mapping protections are downgraded after relocation processing. 1155 */ 1156 error = vm_map_find(kernel_map, ef->object, 0, 1157 (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE, 1158 VM_PROT_ALL, VM_PROT_ALL, 0); 1159 if (error != 0) { 1160 vm_object_deallocate(ef->object); 1161 ef->object = NULL; 1162 goto out; 1163 } 1164 #else 1165 mapbase = malloc_exec(mapsize, M_LINKER, M_WAITOK); 1166 #endif 1167 ef->address = mapbase; 1168 1169 /* 1170 * Read the text and data sections and zero the bss. 1171 */ 1172 for (i = 0; i < nsegs; i++) { 1173 segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 1174 1175 #ifdef SPARSE_MAPPING 1176 /* 1177 * Consecutive segments may have different mapping permissions, 1178 * so be strict and verify that their mappings do not overlap. 1179 */ 1180 if (((vm_offset_t)segbase & PAGE_MASK) != 0) { 1181 error = EINVAL; 1182 goto out; 1183 } 1184 1185 error = vm_map_wire(kernel_map, 1186 (vm_offset_t)segbase, 1187 (vm_offset_t)segbase + round_page(segs[i]->p_memsz), 1188 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 1189 if (error != KERN_SUCCESS) { 1190 error = ENOMEM; 1191 goto out; 1192 } 1193 #endif 1194 1195 error = vn_rdwr(UIO_READ, nd.ni_vp, 1196 segbase, segs[i]->p_filesz, segs[i]->p_offset, 1197 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1198 &resid, td); 1199 if (error != 0) 1200 goto out; 1201 bzero(segbase + segs[i]->p_filesz, 1202 segs[i]->p_memsz - segs[i]->p_filesz); 1203 } 1204 1205 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 1206 1207 lf->address = ef->address; 1208 lf->size = mapsize; 1209 1210 error = parse_dynamic(ef); 1211 if (error != 0) 1212 goto out; 1213 error = parse_dpcpu(ef); 1214 if (error != 0) 1215 goto out; 1216 #ifdef VIMAGE 1217 error = parse_vnet(ef); 1218 if (error != 0) 1219 goto out; 1220 #endif 1221 link_elf_reloc_local(lf); 1222 1223 VOP_UNLOCK(nd.ni_vp); 1224 error = linker_load_dependencies(lf); 1225 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 1226 if (error != 0) 1227 goto out; 1228 error = relocate_file(ef); 1229 if (error != 0) 1230 goto out; 1231 1232 #ifdef SPARSE_MAPPING 1233 /* 1234 * Downgrade permissions on text segment mappings now that relocation 1235 * processing is complete. Restrict permissions on read-only segments. 1236 */ 1237 for (i = 0; i < nsegs; i++) { 1238 vm_prot_t prot; 1239 1240 if (segs[i]->p_type != PT_LOAD) 1241 continue; 1242 1243 prot = VM_PROT_READ; 1244 if ((segs[i]->p_flags & PF_W) != 0) 1245 prot |= VM_PROT_WRITE; 1246 if ((segs[i]->p_flags & PF_X) != 0) 1247 prot |= VM_PROT_EXECUTE; 1248 segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 1249 error = vm_map_protect(kernel_map, 1250 (vm_offset_t)segbase, 1251 (vm_offset_t)segbase + round_page(segs[i]->p_memsz), 1252 prot, 0, VM_MAP_PROTECT_SET_PROT); 1253 if (error != KERN_SUCCESS) { 1254 error = ENOMEM; 1255 goto out; 1256 } 1257 } 1258 #endif 1259 1260 /* 1261 * Try and load the symbol table if it's present. (you can 1262 * strip it!) 1263 */ 1264 nbytes = hdr->e_shnum * hdr->e_shentsize; 1265 if (nbytes == 0 || hdr->e_shoff == 0) 1266 goto nosyms; 1267 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1268 error = vn_rdwr(UIO_READ, nd.ni_vp, 1269 (caddr_t)shdr, nbytes, hdr->e_shoff, 1270 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1271 &resid, td); 1272 if (error != 0) 1273 goto out; 1274 1275 /* Read section string table */ 1276 shstrindex = hdr->e_shstrndx; 1277 if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB && 1278 shdr[shstrindex].sh_size != 0) { 1279 nbytes = shdr[shstrindex].sh_size; 1280 shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1281 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes, 1282 shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 1283 td->td_ucred, NOCRED, &resid, td); 1284 if (error) 1285 goto out; 1286 } 1287 1288 symtabindex = -1; 1289 symstrindex = -1; 1290 for (i = 0; i < hdr->e_shnum; i++) { 1291 if (shdr[i].sh_type == SHT_SYMTAB) { 1292 symtabindex = i; 1293 symstrindex = shdr[i].sh_link; 1294 } else if (shstrs != NULL && shdr[i].sh_name != 0 && 1295 strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) { 1296 /* Record relocated address and size of .ctors. */ 1297 lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr; 1298 lf->ctors_size = shdr[i].sh_size; 1299 } 1300 } 1301 if (symtabindex < 0 || symstrindex < 0) 1302 goto nosyms; 1303 1304 symcnt = shdr[symtabindex].sh_size; 1305 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1306 strcnt = shdr[symstrindex].sh_size; 1307 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1308 1309 error = vn_rdwr(UIO_READ, nd.ni_vp, 1310 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1311 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1312 &resid, td); 1313 if (error != 0) 1314 goto out; 1315 error = vn_rdwr(UIO_READ, nd.ni_vp, 1316 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1317 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1318 &resid, td); 1319 if (error != 0) 1320 goto out; 1321 1322 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1323 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1324 ef->ddbstrcnt = strcnt; 1325 ef->ddbstrtab = ef->strbase; 1326 1327 nosyms: 1328 1329 #ifdef __arm__ 1330 link_elf_locate_exidx(lf, shdr, hdr->e_shnum); 1331 #endif 1332 1333 error = link_elf_link_common_finish(lf); 1334 if (error != 0) 1335 goto out; 1336 1337 *result = lf; 1338 1339 out: 1340 VOP_UNLOCK(nd.ni_vp); 1341 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1342 if (error != 0 && lf != NULL) 1343 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1344 free(shdr, M_LINKER); 1345 free(firstpage, M_LINKER); 1346 free(shstrs, M_LINKER); 1347 1348 return (error); 1349 } 1350 1351 Elf_Addr 1352 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1353 { 1354 elf_file_t ef; 1355 1356 KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class, 1357 ("elf_relocaddr: unexpected linker file %p", lf)); 1358 1359 ef = (elf_file_t)lf; 1360 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1361 return ((x - ef->pcpu_start) + ef->pcpu_base); 1362 #ifdef VIMAGE 1363 if (x >= ef->vnet_start && x < ef->vnet_stop) 1364 return ((x - ef->vnet_start) + ef->vnet_base); 1365 #endif 1366 return (x); 1367 } 1368 1369 static void 1370 link_elf_unload_file(linker_file_t file) 1371 { 1372 elf_file_t ef = (elf_file_t) file; 1373 1374 if (ef->pcpu_base != 0) { 1375 dpcpu_free((void *)ef->pcpu_base, 1376 ef->pcpu_stop - ef->pcpu_start); 1377 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1378 } 1379 #ifdef VIMAGE 1380 if (ef->vnet_base != 0) { 1381 vnet_data_free((void *)ef->vnet_base, 1382 ef->vnet_stop - ef->vnet_start); 1383 elf_set_delete(&set_vnet_list, ef->vnet_start); 1384 } 1385 #endif 1386 #ifdef GDB 1387 if (ef->gdb.l_ld != NULL) { 1388 GDB_STATE(RT_DELETE); 1389 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1390 link_elf_delete_gdb(&ef->gdb); 1391 GDB_STATE(RT_CONSISTENT); 1392 } 1393 #endif 1394 1395 /* Notify MD code that a module is being unloaded. */ 1396 elf_cpu_unload_file(file); 1397 1398 if (ef->preloaded) { 1399 link_elf_unload_preload(file); 1400 return; 1401 } 1402 1403 #ifdef SPARSE_MAPPING 1404 if (ef->object != NULL) { 1405 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1406 (vm_offset_t) ef->address 1407 + (ef->object->size << PAGE_SHIFT)); 1408 } 1409 #else 1410 free(ef->address, M_LINKER); 1411 #endif 1412 free(ef->symbase, M_LINKER); 1413 free(ef->strbase, M_LINKER); 1414 free(ef->ctftab, M_LINKER); 1415 free(ef->ctfoff, M_LINKER); 1416 free(ef->typoff, M_LINKER); 1417 } 1418 1419 static void 1420 link_elf_unload_preload(linker_file_t file) 1421 { 1422 1423 if (file->pathname != NULL) 1424 preload_delete_name(file->pathname); 1425 } 1426 1427 static const char * 1428 symbol_name(elf_file_t ef, Elf_Size r_info) 1429 { 1430 const Elf_Sym *ref; 1431 1432 if (ELF_R_SYM(r_info)) { 1433 ref = ef->symtab + ELF_R_SYM(r_info); 1434 return (ef->strtab + ref->st_name); 1435 } 1436 return (NULL); 1437 } 1438 1439 static int 1440 symbol_type(elf_file_t ef, Elf_Size r_info) 1441 { 1442 const Elf_Sym *ref; 1443 1444 if (ELF_R_SYM(r_info)) { 1445 ref = ef->symtab + ELF_R_SYM(r_info); 1446 return (ELF_ST_TYPE(ref->st_info)); 1447 } 1448 return (STT_NOTYPE); 1449 } 1450 1451 static int 1452 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc, 1453 bool ifuncs) 1454 { 1455 const Elf_Rel *rel; 1456 const Elf_Rela *rela; 1457 const char *symname; 1458 1459 TSENTER(); 1460 #define APPLY_RELOCS(iter, tbl, tblsize, type) do { \ 1461 for ((iter) = (tbl); (iter) != NULL && \ 1462 (iter) < (tbl) + (tblsize) / sizeof(*(iter)); (iter)++) { \ 1463 if ((symbol_type(ef, (iter)->r_info) == \ 1464 STT_GNU_IFUNC || \ 1465 elf_is_ifunc_reloc((iter)->r_info)) != ifuncs) \ 1466 continue; \ 1467 if (reloc(&ef->lf, (Elf_Addr)ef->address, \ 1468 (iter), (type), lookup)) { \ 1469 symname = symbol_name(ef, (iter)->r_info); \ 1470 printf("link_elf: symbol %s undefined\n", \ 1471 symname); \ 1472 return (ENOENT); \ 1473 } \ 1474 } \ 1475 } while (0) 1476 1477 APPLY_RELOCS(rel, ef->rel, ef->relsize, ELF_RELOC_REL); 1478 TSENTER2("ef->rela"); 1479 APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA); 1480 TSEXIT2("ef->rela"); 1481 APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL); 1482 APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA); 1483 1484 #undef APPLY_RELOCS 1485 1486 TSEXIT(); 1487 return (0); 1488 } 1489 1490 static int 1491 relocate_file(elf_file_t ef) 1492 { 1493 int error; 1494 1495 error = relocate_file1(ef, elf_lookup, elf_reloc, false); 1496 if (error == 0) 1497 error = relocate_file1(ef, elf_lookup, elf_reloc, true); 1498 return (error); 1499 } 1500 1501 /* 1502 * SysV hash function for symbol table lookup. It is specified by the 1503 * System V ABI. 1504 */ 1505 static Elf32_Word 1506 elf_hash(const char *name) 1507 { 1508 const unsigned char *p = (const unsigned char *)name; 1509 Elf32_Word h = 0; 1510 1511 while (*p != '\0') { 1512 h = (h << 4) + *p++; 1513 h ^= (h >> 24) & 0xf0; 1514 } 1515 return (h & 0x0fffffff); 1516 } 1517 1518 static int 1519 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym, 1520 bool see_local) 1521 { 1522 elf_file_t ef = (elf_file_t) lf; 1523 unsigned long symnum; 1524 const Elf_Sym* symp; 1525 const char *strp; 1526 Elf32_Word hash; 1527 1528 /* If we don't have a hash, bail. */ 1529 if (ef->buckets == NULL || ef->nbuckets == 0) { 1530 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1531 return (ENOENT); 1532 } 1533 1534 /* First, search hashed global symbols */ 1535 hash = elf_hash(name); 1536 symnum = ef->buckets[hash % ef->nbuckets]; 1537 1538 while (symnum != STN_UNDEF) { 1539 if (symnum >= ef->nchains) { 1540 printf("%s: corrupt symbol table\n", __func__); 1541 return (ENOENT); 1542 } 1543 1544 symp = ef->symtab + symnum; 1545 if (symp->st_name == 0) { 1546 printf("%s: corrupt symbol table\n", __func__); 1547 return (ENOENT); 1548 } 1549 1550 strp = ef->strtab + symp->st_name; 1551 1552 if (strcmp(name, strp) == 0) { 1553 if (symp->st_shndx != SHN_UNDEF || 1554 (symp->st_value != 0 && 1555 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1556 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1557 if (see_local || 1558 ELF_ST_BIND(symp->st_info) != STB_LOCAL) { 1559 *sym = (c_linker_sym_t) symp; 1560 return (0); 1561 } 1562 } 1563 return (ENOENT); 1564 } 1565 1566 symnum = ef->chains[symnum]; 1567 } 1568 1569 return (ENOENT); 1570 } 1571 1572 static int 1573 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1574 { 1575 if (link_elf_leak_locals) 1576 return (link_elf_lookup_debug_symbol(lf, name, sym)); 1577 return (link_elf_lookup_symbol1(lf, name, sym, false)); 1578 } 1579 1580 static int 1581 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name, 1582 c_linker_sym_t *sym) 1583 { 1584 elf_file_t ef = (elf_file_t)lf; 1585 const Elf_Sym* symp; 1586 const char *strp; 1587 int i; 1588 1589 if (link_elf_lookup_symbol1(lf, name, sym, true) == 0) 1590 return (0); 1591 1592 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1593 strp = ef->ddbstrtab + symp->st_name; 1594 if (strcmp(name, strp) == 0) { 1595 if (symp->st_shndx != SHN_UNDEF || 1596 (symp->st_value != 0 && 1597 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1598 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1599 *sym = (c_linker_sym_t) symp; 1600 return (0); 1601 } 1602 return (ENOENT); 1603 } 1604 } 1605 1606 return (ENOENT); 1607 } 1608 1609 static int 1610 link_elf_lookup_debug_symbol_ctf(linker_file_t lf, const char *name, 1611 c_linker_sym_t *sym, linker_ctf_t *lc) 1612 { 1613 elf_file_t ef = (elf_file_t)lf; 1614 const Elf_Sym *symp; 1615 const char *strp; 1616 int i; 1617 1618 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1619 strp = ef->ddbstrtab + symp->st_name; 1620 if (strcmp(name, strp) == 0) { 1621 if (symp->st_shndx != SHN_UNDEF || 1622 (symp->st_value != 0 && 1623 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1624 ELF_ST_TYPE(symp->st_info) == 1625 STT_GNU_IFUNC))) { 1626 *sym = (c_linker_sym_t)symp; 1627 break; 1628 } 1629 return (ENOENT); 1630 } 1631 } 1632 1633 /* Populate CTF info structure if symbol was found. */ 1634 return (i < ef->ddbsymcnt ? link_elf_ctf_get_ddb(lf, lc) : ENOENT); 1635 } 1636 1637 static int 1638 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym, 1639 linker_symval_t *symval, bool see_local) 1640 { 1641 elf_file_t ef; 1642 const Elf_Sym *es; 1643 caddr_t val; 1644 1645 ef = (elf_file_t)lf; 1646 es = (const Elf_Sym *)sym; 1647 if (es >= ef->symtab && es < ef->symtab + ef->nchains) { 1648 if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL) 1649 return (ENOENT); 1650 symval->name = ef->strtab + es->st_name; 1651 val = (caddr_t)ef->address + es->st_value; 1652 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1653 val = ((caddr_t (*)(void))val)(); 1654 symval->value = val; 1655 symval->size = es->st_size; 1656 return (0); 1657 } 1658 return (ENOENT); 1659 } 1660 1661 static int 1662 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1663 linker_symval_t *symval) 1664 { 1665 if (link_elf_leak_locals) 1666 return (link_elf_debug_symbol_values(lf, sym, symval)); 1667 return (link_elf_symbol_values1(lf, sym, symval, false)); 1668 } 1669 1670 static int 1671 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1672 linker_symval_t *symval) 1673 { 1674 elf_file_t ef = (elf_file_t)lf; 1675 const Elf_Sym *es = (const Elf_Sym *)sym; 1676 caddr_t val; 1677 1678 if (link_elf_symbol_values1(lf, sym, symval, true) == 0) 1679 return (0); 1680 if (ef->symtab == ef->ddbsymtab) 1681 return (ENOENT); 1682 1683 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1684 symval->name = ef->ddbstrtab + es->st_name; 1685 val = (caddr_t)ef->address + es->st_value; 1686 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1687 val = ((caddr_t (*)(void))val)(); 1688 symval->value = val; 1689 symval->size = es->st_size; 1690 return (0); 1691 } 1692 return (ENOENT); 1693 } 1694 1695 static int 1696 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1697 c_linker_sym_t *sym, long *diffp) 1698 { 1699 elf_file_t ef = (elf_file_t)lf; 1700 u_long off = (uintptr_t)(void *)value; 1701 u_long diff = off; 1702 u_long st_value; 1703 const Elf_Sym *es; 1704 const Elf_Sym *best = NULL; 1705 int i; 1706 1707 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1708 if (es->st_name == 0) 1709 continue; 1710 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1711 if (off >= st_value) { 1712 if (off - st_value < diff) { 1713 diff = off - st_value; 1714 best = es; 1715 if (diff == 0) 1716 break; 1717 } else if (off - st_value == diff) { 1718 best = es; 1719 } 1720 } 1721 } 1722 if (best == NULL) 1723 *diffp = off; 1724 else 1725 *diffp = diff; 1726 *sym = (c_linker_sym_t) best; 1727 1728 return (0); 1729 } 1730 1731 /* 1732 * Look up a linker set on an ELF system. 1733 */ 1734 static int 1735 link_elf_lookup_set(linker_file_t lf, const char *name, 1736 void ***startp, void ***stopp, int *countp) 1737 { 1738 c_linker_sym_t sym; 1739 linker_symval_t symval; 1740 char *setsym; 1741 void **start, **stop; 1742 int len, error = 0, count; 1743 1744 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1745 setsym = malloc(len, M_LINKER, M_WAITOK); 1746 1747 /* get address of first entry */ 1748 snprintf(setsym, len, "%s%s", "__start_set_", name); 1749 error = link_elf_lookup_symbol(lf, setsym, &sym); 1750 if (error != 0) 1751 goto out; 1752 link_elf_symbol_values(lf, sym, &symval); 1753 if (symval.value == 0) { 1754 error = ESRCH; 1755 goto out; 1756 } 1757 start = (void **)symval.value; 1758 1759 /* get address of last entry */ 1760 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1761 error = link_elf_lookup_symbol(lf, setsym, &sym); 1762 if (error != 0) 1763 goto out; 1764 link_elf_symbol_values(lf, sym, &symval); 1765 if (symval.value == 0) { 1766 error = ESRCH; 1767 goto out; 1768 } 1769 stop = (void **)symval.value; 1770 1771 /* and the number of entries */ 1772 count = stop - start; 1773 1774 /* and copy out */ 1775 if (startp != NULL) 1776 *startp = start; 1777 if (stopp != NULL) 1778 *stopp = stop; 1779 if (countp != NULL) 1780 *countp = count; 1781 1782 out: 1783 free(setsym, M_LINKER); 1784 return (error); 1785 } 1786 1787 static int 1788 link_elf_each_function_name(linker_file_t file, 1789 int (*callback)(const char *, void *), void *opaque) 1790 { 1791 elf_file_t ef = (elf_file_t)file; 1792 const Elf_Sym *symp; 1793 int i, error; 1794 1795 /* Exhaustive search */ 1796 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1797 if (symp->st_value != 0 && 1798 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1799 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1800 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1801 if (error != 0) 1802 return (error); 1803 } 1804 } 1805 return (0); 1806 } 1807 1808 static int 1809 link_elf_each_function_nameval(linker_file_t file, 1810 linker_function_nameval_callback_t callback, void *opaque) 1811 { 1812 linker_symval_t symval; 1813 elf_file_t ef = (elf_file_t)file; 1814 const Elf_Sym *symp; 1815 int i, error; 1816 1817 /* Exhaustive search */ 1818 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1819 if (symp->st_value != 0 && 1820 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1821 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1822 error = link_elf_debug_symbol_values(file, 1823 (c_linker_sym_t) symp, &symval); 1824 if (error == 0) 1825 error = callback(file, i, &symval, opaque); 1826 if (error != 0) 1827 return (error); 1828 } 1829 } 1830 return (0); 1831 } 1832 1833 const Elf_Sym * 1834 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1835 { 1836 elf_file_t ef = (elf_file_t)lf; 1837 1838 if (symidx >= ef->nchains) 1839 return (NULL); 1840 return (ef->symtab + symidx); 1841 } 1842 1843 const char * 1844 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1845 { 1846 elf_file_t ef = (elf_file_t)lf; 1847 const Elf_Sym *sym; 1848 1849 if (symidx >= ef->nchains) 1850 return (NULL); 1851 sym = ef->symtab + symidx; 1852 return (ef->strtab + sym->st_name); 1853 } 1854 1855 /* 1856 * Symbol lookup function that can be used when the symbol index is known (ie 1857 * in relocations). It uses the symbol index instead of doing a fully fledged 1858 * hash table based lookup when such is valid. For example for local symbols. 1859 * This is not only more efficient, it's also more correct. It's not always 1860 * the case that the symbol can be found through the hash table. 1861 */ 1862 static int 1863 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1864 { 1865 elf_file_t ef = (elf_file_t)lf; 1866 const Elf_Sym *sym; 1867 const char *symbol; 1868 Elf_Addr addr, start, base; 1869 1870 /* Don't even try to lookup the symbol if the index is bogus. */ 1871 if (symidx >= ef->nchains) { 1872 *res = 0; 1873 return (EINVAL); 1874 } 1875 1876 sym = ef->symtab + symidx; 1877 1878 /* 1879 * Don't do a full lookup when the symbol is local. It may even 1880 * fail because it may not be found through the hash table. 1881 */ 1882 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1883 /* Force lookup failure when we have an insanity. */ 1884 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) { 1885 *res = 0; 1886 return (EINVAL); 1887 } 1888 *res = ((Elf_Addr)ef->address + sym->st_value); 1889 return (0); 1890 } 1891 1892 /* 1893 * XXX we can avoid doing a hash table based lookup for global 1894 * symbols as well. This however is not always valid, so we'll 1895 * just do it the hard way for now. Performance tweaks can 1896 * always be added. 1897 */ 1898 1899 symbol = ef->strtab + sym->st_name; 1900 1901 /* Force a lookup failure if the symbol name is bogus. */ 1902 if (*symbol == 0) { 1903 *res = 0; 1904 return (EINVAL); 1905 } 1906 1907 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1908 if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1909 *res = 0; 1910 return (EINVAL); 1911 } 1912 1913 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1914 addr = addr - start + base; 1915 #ifdef VIMAGE 1916 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1917 addr = addr - start + base; 1918 #endif 1919 *res = addr; 1920 return (0); 1921 } 1922 1923 static void 1924 link_elf_reloc_local(linker_file_t lf) 1925 { 1926 const Elf_Rel *rellim; 1927 const Elf_Rel *rel; 1928 const Elf_Rela *relalim; 1929 const Elf_Rela *rela; 1930 elf_file_t ef = (elf_file_t)lf; 1931 1932 /* Perform relocations without addend if there are any: */ 1933 if ((rel = ef->rel) != NULL) { 1934 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1935 while (rel < rellim) { 1936 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1937 ELF_RELOC_REL, elf_lookup); 1938 rel++; 1939 } 1940 } 1941 1942 /* Perform relocations with addend if there are any: */ 1943 if ((rela = ef->rela) != NULL) { 1944 relalim = (const Elf_Rela *) 1945 ((const char *)ef->rela + ef->relasize); 1946 while (rela < relalim) { 1947 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1948 ELF_RELOC_RELA, elf_lookup); 1949 rela++; 1950 } 1951 } 1952 } 1953 1954 static long 1955 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1956 { 1957 elf_file_t ef = (elf_file_t)lf; 1958 1959 *symtab = ef->ddbsymtab; 1960 1961 if (*symtab == NULL) 1962 return (0); 1963 1964 return (ef->ddbsymcnt); 1965 } 1966 1967 static long 1968 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1969 { 1970 elf_file_t ef = (elf_file_t)lf; 1971 1972 *strtab = ef->ddbstrtab; 1973 1974 if (*strtab == NULL) 1975 return (0); 1976 1977 return (ef->ddbstrcnt); 1978 } 1979 1980 #ifdef VIMAGE 1981 static void 1982 link_elf_propagate_vnets(linker_file_t lf) 1983 { 1984 elf_file_t ef = (elf_file_t)lf; 1985 int size; 1986 1987 if (ef->vnet_base != 0) { 1988 size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start; 1989 vnet_data_copy((void *)ef->vnet_base, size); 1990 } 1991 } 1992 #endif 1993 1994 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) || defined(__powerpc__) 1995 /* 1996 * Use this lookup routine when performing relocations early during boot. 1997 * The generic lookup routine depends on kobj, which is not initialized 1998 * at that point. 1999 */ 2000 static int 2001 elf_lookup_ifunc(linker_file_t lf, Elf_Size symidx, int deps __unused, 2002 Elf_Addr *res) 2003 { 2004 elf_file_t ef; 2005 const Elf_Sym *symp; 2006 caddr_t val; 2007 2008 ef = (elf_file_t)lf; 2009 symp = ef->symtab + symidx; 2010 if (ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC) { 2011 val = (caddr_t)ef->address + symp->st_value; 2012 *res = ((Elf_Addr (*)(void))val)(); 2013 return (0); 2014 } 2015 return (ENOENT); 2016 } 2017 2018 void 2019 link_elf_ireloc(caddr_t kmdp) 2020 { 2021 struct elf_file eff; 2022 elf_file_t ef; 2023 2024 TSENTER(); 2025 ef = &eff; 2026 2027 bzero_early(ef, sizeof(*ef)); 2028 2029 ef->modptr = kmdp; 2030 ef->dynamic = (Elf_Dyn *)&_DYNAMIC; 2031 2032 #ifdef RELOCATABLE_KERNEL 2033 ef->address = (caddr_t) (__startkernel - KERNBASE); 2034 #else 2035 ef->address = 0; 2036 #endif 2037 parse_dynamic(ef); 2038 2039 link_elf_preload_parse_symbols(ef); 2040 relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true); 2041 TSEXIT(); 2042 } 2043 2044 #if defined(__aarch64__) || defined(__amd64__) 2045 void 2046 link_elf_late_ireloc(void) 2047 { 2048 elf_file_t ef; 2049 2050 KASSERT(linker_kernel_file != NULL, 2051 ("link_elf_late_ireloc: No kernel linker file found")); 2052 ef = (elf_file_t)linker_kernel_file; 2053 2054 relocate_file1(ef, elf_lookup_ifunc, elf_reloc_late, true); 2055 } 2056 #endif 2057 #endif 2058