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(elf_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 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 = (char *)preload_search_info(preload_kmdp, MODINFO_NAME); 461 if (modname == NULL) 462 modname = "kernel"; 463 linker_kernel_file = linker_make_file(modname, &link_elf_class); 464 if (linker_kernel_file == NULL) 465 panic("%s: Can't create linker structures for kernel", 466 __func__); 467 468 ef = (elf_file_t) linker_kernel_file; 469 ef->preloaded = 1; 470 #ifdef RELOCATABLE_KERNEL 471 /* Compute relative displacement */ 472 ef->address = (caddr_t) (__startkernel - KERNBASE); 473 #else 474 ef->address = 0; 475 #endif 476 #ifdef SPARSE_MAPPING 477 ef->object = NULL; 478 #endif 479 ef->dynamic = dp; 480 481 if (dp != NULL) 482 parse_dynamic(ef); 483 #ifdef RELOCATABLE_KERNEL 484 linker_kernel_file->address = (caddr_t)__startkernel; 485 linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel); 486 kern_relbase = (unsigned long)__startkernel; 487 #else 488 linker_kernel_file->address += KERNBASE; 489 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 490 #endif 491 492 if (preload_kmdp != NULL) { 493 ef->modptr = preload_kmdp; 494 baseptr = preload_search_info(preload_kmdp, MODINFO_ADDR); 495 if (baseptr != NULL) 496 linker_kernel_file->address = *(caddr_t *)baseptr; 497 sizeptr = preload_search_info(preload_kmdp, MODINFO_SIZE); 498 if (sizeptr != NULL) 499 linker_kernel_file->size = *(size_t *)sizeptr; 500 ctors_addrp = (Elf_Addr *)preload_search_info(preload_kmdp, 501 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 502 ctors_sizep = (Elf_Size *)preload_search_info(preload_kmdp, 503 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 504 if (ctors_addrp != NULL && ctors_sizep != NULL) { 505 linker_kernel_file->ctors_addr = ef->address + 506 *ctors_addrp; 507 linker_kernel_file->ctors_size = *ctors_sizep; 508 } 509 } 510 (void)link_elf_preload_parse_symbols(ef); 511 512 #ifdef GDB 513 r_debug.r_map = NULL; 514 r_debug.r_brk = r_debug_state; 515 r_debug.r_state = RT_CONSISTENT; 516 #endif 517 518 (void)link_elf_link_common_finish(linker_kernel_file); 519 linker_kernel_file->flags |= LINKER_FILE_LINKED; 520 TAILQ_INIT(&set_pcpu_list); 521 ef->pcpu_start = DPCPU_START; 522 ef->pcpu_stop = DPCPU_STOP; 523 ef->pcpu_base = DPCPU_START; 524 #ifdef VIMAGE 525 TAILQ_INIT(&set_vnet_list); 526 vnet_save_init((void *)VNET_START, VNET_STOP - VNET_START); 527 ef->vnet_start = VNET_START; 528 ef->vnet_stop = VNET_STOP; 529 ef->vnet_base = VNET_START; 530 #endif 531 } 532 533 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL); 534 535 static int 536 link_elf_preload_parse_symbols(elf_file_t ef) 537 { 538 caddr_t pointer; 539 caddr_t ssym, esym, base; 540 caddr_t strtab; 541 int strcnt; 542 Elf_Sym *symtab; 543 int symcnt; 544 545 if (ef->modptr == NULL) 546 return (0); 547 pointer = preload_search_info(ef->modptr, 548 MODINFO_METADATA | MODINFOMD_SSYM); 549 if (pointer == NULL) 550 return (0); 551 ssym = *(caddr_t *)pointer; 552 pointer = preload_search_info(ef->modptr, 553 MODINFO_METADATA | MODINFOMD_ESYM); 554 if (pointer == NULL) 555 return (0); 556 esym = *(caddr_t *)pointer; 557 558 base = ssym; 559 560 symcnt = *(long *)base; 561 base += sizeof(long); 562 symtab = (Elf_Sym *)base; 563 base += roundup(symcnt, sizeof(long)); 564 565 if (base > esym || base < ssym) { 566 printf("Symbols are corrupt!\n"); 567 return (EINVAL); 568 } 569 570 strcnt = *(long *)base; 571 base += sizeof(long); 572 strtab = base; 573 base += roundup(strcnt, sizeof(long)); 574 575 if (base > esym || base < ssym) { 576 printf("Symbols are corrupt!\n"); 577 return (EINVAL); 578 } 579 580 ef->ddbsymtab = symtab; 581 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 582 ef->ddbstrtab = strtab; 583 ef->ddbstrcnt = strcnt; 584 585 return (0); 586 } 587 588 static int 589 parse_dynamic(elf_file_t ef) 590 { 591 Elf_Dyn *dp; 592 int plttype = DT_REL; 593 594 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 595 switch (dp->d_tag) { 596 case DT_HASH: 597 { 598 /* From src/libexec/rtld-elf/rtld.c */ 599 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 600 (ef->address + dp->d_un.d_ptr); 601 ef->nbuckets = hashtab[0]; 602 ef->nchains = hashtab[1]; 603 ef->buckets = hashtab + 2; 604 ef->chains = ef->buckets + ef->nbuckets; 605 break; 606 } 607 case DT_STRTAB: 608 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 609 break; 610 case DT_STRSZ: 611 ef->strsz = dp->d_un.d_val; 612 break; 613 case DT_SYMTAB: 614 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 615 break; 616 case DT_SYMENT: 617 if (dp->d_un.d_val != sizeof(Elf_Sym)) 618 return (ENOEXEC); 619 break; 620 case DT_PLTGOT: 621 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 622 break; 623 case DT_REL: 624 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 625 break; 626 case DT_RELSZ: 627 ef->relsize = dp->d_un.d_val; 628 break; 629 case DT_RELENT: 630 if (dp->d_un.d_val != sizeof(Elf_Rel)) 631 return (ENOEXEC); 632 break; 633 case DT_JMPREL: 634 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 635 break; 636 case DT_PLTRELSZ: 637 ef->pltrelsize = dp->d_un.d_val; 638 break; 639 case DT_RELA: 640 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 641 break; 642 case DT_RELASZ: 643 ef->relasize = dp->d_un.d_val; 644 break; 645 case DT_RELAENT: 646 if (dp->d_un.d_val != sizeof(Elf_Rela)) 647 return (ENOEXEC); 648 break; 649 case DT_PLTREL: 650 plttype = dp->d_un.d_val; 651 if (plttype != DT_REL && plttype != DT_RELA) 652 return (ENOEXEC); 653 break; 654 #ifdef GDB 655 case DT_DEBUG: 656 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 657 break; 658 #endif 659 } 660 } 661 662 if (plttype == DT_RELA) { 663 ef->pltrela = (const Elf_Rela *)ef->pltrel; 664 ef->pltrel = NULL; 665 ef->pltrelasize = ef->pltrelsize; 666 ef->pltrelsize = 0; 667 } 668 669 ef->ddbsymtab = ef->symtab; 670 ef->ddbsymcnt = ef->nchains; 671 ef->ddbstrtab = ef->strtab; 672 ef->ddbstrcnt = ef->strsz; 673 674 return elf_cpu_parse_dynamic(ef->address, ef->dynamic); 675 } 676 677 #define LS_PADDING 0x90909090 678 static int 679 parse_dpcpu(elf_file_t ef) 680 { 681 int error, size; 682 #if defined(__i386__) 683 uint32_t pad; 684 #endif 685 686 ef->pcpu_start = 0; 687 ef->pcpu_stop = 0; 688 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 689 (void ***)&ef->pcpu_stop, NULL); 690 /* Error just means there is no pcpu set to relocate. */ 691 if (error != 0) 692 return (0); 693 size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start; 694 /* Empty set? */ 695 if (size < 1) 696 return (0); 697 #if defined(__i386__) 698 /* In case we do find __start/stop_set_ symbols double-check. */ 699 if (size < 4) { 700 uprintf("Kernel module '%s' must be recompiled with " 701 "linker script\n", ef->lf.pathname); 702 return (ENOEXEC); 703 } 704 705 /* Padding from linker-script correct? */ 706 pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad)); 707 if (pad != LS_PADDING) { 708 uprintf("Kernel module '%s' must be recompiled with " 709 "linker script, invalid padding %#04x (%#04x)\n", 710 ef->lf.pathname, pad, LS_PADDING); 711 return (ENOEXEC); 712 } 713 /* If we only have valid padding, nothing to do. */ 714 if (size == 4) 715 return (0); 716 #endif 717 /* 718 * Allocate space in the primary pcpu area. Copy in our 719 * initialization from the data section and then initialize 720 * all per-cpu storage from that. 721 */ 722 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size); 723 if (ef->pcpu_base == 0) { 724 printf("%s: pcpu module space is out of space; " 725 "cannot allocate %d for %s\n", 726 __func__, size, ef->lf.pathname); 727 return (ENOSPC); 728 } 729 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size); 730 dpcpu_copy((void *)ef->pcpu_base, size); 731 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 732 ef->pcpu_base); 733 734 return (0); 735 } 736 737 #ifdef VIMAGE 738 static int 739 parse_vnet(elf_file_t ef) 740 { 741 int error, size; 742 #if defined(__i386__) 743 uint32_t pad; 744 #endif 745 746 ef->vnet_start = 0; 747 ef->vnet_stop = 0; 748 ef->vnet_base = 0; 749 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 750 (void ***)&ef->vnet_stop, NULL); 751 /* Error just means there is no vnet data set to relocate. */ 752 if (error != 0) 753 return (0); 754 size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start; 755 /* Empty set? */ 756 if (size < 1) 757 return (0); 758 #if defined(__i386__) 759 /* In case we do find __start/stop_set_ symbols double-check. */ 760 if (size < 4) { 761 uprintf("Kernel module '%s' must be recompiled with " 762 "linker script\n", ef->lf.pathname); 763 return (ENOEXEC); 764 } 765 766 /* Padding from linker-script correct? */ 767 pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad)); 768 if (pad != LS_PADDING) { 769 uprintf("Kernel module '%s' must be recompiled with " 770 "linker script, invalid padding %#04x (%#04x)\n", 771 ef->lf.pathname, pad, LS_PADDING); 772 return (ENOEXEC); 773 } 774 /* If we only have valid padding, nothing to do. */ 775 if (size == 4) 776 return (0); 777 #endif 778 /* 779 * Allocate space in the primary vnet area. Copy in our 780 * initialization from the data section and then initialize 781 * all per-vnet storage from that. 782 */ 783 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size); 784 if (ef->vnet_base == 0) { 785 printf("%s: vnet module space is out of space; " 786 "cannot allocate %d for %s\n", 787 __func__, size, ef->lf.pathname); 788 return (ENOSPC); 789 } 790 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size); 791 vnet_save_init((void *)ef->vnet_base, size); 792 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 793 ef->vnet_base); 794 795 return (0); 796 } 797 #endif 798 #undef LS_PADDING 799 800 /* 801 * Apply the specified protection to the loadable segments of a preloaded linker 802 * file. If "reset" is not set, the original segment protections are ORed in. 803 */ 804 static int 805 preload_protect1(elf_file_t ef, vm_prot_t prot, bool reset) 806 { 807 #if defined(__aarch64__) || defined(__amd64__) 808 Elf_Ehdr *hdr; 809 Elf_Phdr *phdr, *phlimit; 810 vm_prot_t nprot; 811 int error; 812 813 error = 0; 814 hdr = (Elf_Ehdr *)ef->address; 815 phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff); 816 phlimit = phdr + hdr->e_phnum; 817 for (; phdr < phlimit; phdr++) { 818 if (phdr->p_type != PT_LOAD) 819 continue; 820 821 nprot = VM_PROT_NONE; 822 if (!reset) { 823 nprot = VM_PROT_READ; 824 if ((phdr->p_flags & PF_W) != 0) 825 nprot |= VM_PROT_WRITE; 826 if ((phdr->p_flags & PF_X) != 0) 827 nprot |= VM_PROT_EXECUTE; 828 } 829 error = pmap_change_prot((vm_offset_t)ef->address + 830 phdr->p_vaddr, round_page(phdr->p_memsz), prot | nprot); 831 if (error != 0) 832 break; 833 } 834 return (error); 835 #else 836 return (0); 837 #endif 838 } 839 840 static int 841 preload_protect(elf_file_t ef, vm_prot_t prot) 842 { 843 return (preload_protect1(ef, prot, false)); 844 } 845 846 static int 847 preload_protect_reset(elf_file_t ef, vm_prot_t prot) 848 { 849 return (preload_protect1(ef, prot, true)); 850 } 851 852 #ifdef __arm__ 853 /* 854 * Locate the ARM exception/unwind table info for DDB and stack(9) use by 855 * searching for the section header that describes it. There may be no unwind 856 * info, for example in a module containing only data. 857 */ 858 static void 859 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr) 860 { 861 int i; 862 863 for (i = 0; i < nhdr; i++) { 864 if (shdr[i].sh_type == SHT_ARM_EXIDX) { 865 lf->exidx_addr = shdr[i].sh_addr + lf->address; 866 lf->exidx_size = shdr[i].sh_size; 867 break; 868 } 869 } 870 } 871 872 /* 873 * Locate the section headers metadata in a preloaded module, then use it to 874 * locate the exception/unwind table in the module. The size of the metadata 875 * block is stored in a uint32 word immediately before the data itself, and a 876 * comment in preload_search_info() says it is safe to rely on that. 877 */ 878 static void 879 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr) 880 { 881 uint32_t *modinfo; 882 Elf_Shdr *shdr; 883 uint32_t nhdr; 884 885 modinfo = (uint32_t *)preload_search_info(modptr, 886 MODINFO_METADATA | MODINFOMD_SHDR); 887 if (modinfo != NULL) { 888 shdr = (Elf_Shdr *)modinfo; 889 nhdr = modinfo[-1] / sizeof(Elf_Shdr); 890 link_elf_locate_exidx(lf, shdr, nhdr); 891 } 892 } 893 894 #endif /* __arm__ */ 895 896 static int 897 link_elf_link_preload(linker_class_t cls, const char *filename, 898 linker_file_t *result) 899 { 900 Elf_Addr *ctors_addrp; 901 Elf_Size *ctors_sizep; 902 caddr_t modptr, baseptr, sizeptr, dynptr; 903 char *type; 904 elf_file_t ef; 905 linker_file_t lf; 906 int error; 907 vm_offset_t dp; 908 909 /* Look to see if we have the file preloaded */ 910 modptr = preload_search_by_name(filename); 911 if (modptr == NULL) 912 return (ENOENT); 913 914 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 915 baseptr = preload_search_info(modptr, MODINFO_ADDR); 916 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 917 dynptr = preload_search_info(modptr, 918 MODINFO_METADATA | MODINFOMD_DYNAMIC); 919 if (type == NULL || strcmp(type, preload_modtype) != 0) 920 return (EFTYPE); 921 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 922 return (EINVAL); 923 924 lf = linker_make_file(filename, &link_elf_class); 925 if (lf == NULL) 926 return (ENOMEM); 927 928 ef = (elf_file_t) lf; 929 ef->preloaded = 1; 930 ef->modptr = modptr; 931 ef->address = *(caddr_t *)baseptr; 932 #ifdef SPARSE_MAPPING 933 ef->object = NULL; 934 #endif 935 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 936 ef->dynamic = (Elf_Dyn *)dp; 937 lf->address = ef->address; 938 lf->size = *(size_t *)sizeptr; 939 940 ctors_addrp = (Elf_Addr *)preload_search_info(modptr, 941 MODINFO_METADATA | MODINFOMD_CTORS_ADDR); 942 ctors_sizep = (Elf_Size *)preload_search_info(modptr, 943 MODINFO_METADATA | MODINFOMD_CTORS_SIZE); 944 if (ctors_addrp != NULL && ctors_sizep != NULL) { 945 lf->ctors_addr = ef->address + *ctors_addrp; 946 lf->ctors_size = *ctors_sizep; 947 } 948 949 #ifdef __arm__ 950 link_elf_locate_exidx_preload(lf, modptr); 951 #endif 952 953 error = parse_dynamic(ef); 954 if (error == 0) 955 error = parse_dpcpu(ef); 956 #ifdef VIMAGE 957 if (error == 0) 958 error = parse_vnet(ef); 959 #endif 960 if (error == 0) 961 error = preload_protect(ef, VM_PROT_ALL); 962 if (error != 0) { 963 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 964 return (error); 965 } 966 link_elf_reloc_local(lf); 967 *result = lf; 968 return (0); 969 } 970 971 static int 972 link_elf_link_preload_finish(linker_file_t lf) 973 { 974 elf_file_t ef; 975 int error; 976 977 ef = (elf_file_t) lf; 978 error = relocate_file(ef); 979 if (error == 0) 980 error = preload_protect(ef, VM_PROT_NONE); 981 if (error != 0) 982 return (error); 983 (void)link_elf_preload_parse_symbols(ef); 984 985 return (link_elf_link_common_finish(lf)); 986 } 987 988 static int 989 link_elf_load_file(linker_class_t cls, const char* filename, 990 linker_file_t* result) 991 { 992 struct nameidata nd; 993 struct thread* td = curthread; /* XXX */ 994 Elf_Ehdr *hdr; 995 caddr_t firstpage, segbase; 996 int nbytes, i; 997 Elf_Phdr *phdr; 998 Elf_Phdr *phlimit; 999 Elf_Phdr *segs[MAXSEGS]; 1000 int nsegs; 1001 Elf_Phdr *phdyn; 1002 caddr_t mapbase; 1003 size_t mapsize; 1004 Elf_Addr base_vaddr; 1005 Elf_Addr base_vlimit; 1006 int error = 0; 1007 ssize_t resid; 1008 int flags; 1009 elf_file_t ef; 1010 linker_file_t lf; 1011 Elf_Shdr *shdr; 1012 int symtabindex; 1013 int symstrindex; 1014 int shstrindex; 1015 int symcnt; 1016 int strcnt; 1017 char *shstrs; 1018 1019 shdr = NULL; 1020 lf = NULL; 1021 shstrs = NULL; 1022 1023 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename); 1024 flags = FREAD; 1025 error = vn_open(&nd, &flags, 0, NULL); 1026 if (error != 0) 1027 return (error); 1028 NDFREE_PNBUF(&nd); 1029 if (nd.ni_vp->v_type != VREG) { 1030 error = ENOEXEC; 1031 firstpage = NULL; 1032 goto out; 1033 } 1034 #ifdef MAC 1035 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 1036 if (error != 0) { 1037 firstpage = NULL; 1038 goto out; 1039 } 1040 #endif 1041 1042 /* 1043 * Read the elf header from the file. 1044 */ 1045 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 1046 hdr = (Elf_Ehdr *)firstpage; 1047 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 1048 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1049 &resid, td); 1050 nbytes = PAGE_SIZE - resid; 1051 if (error != 0) 1052 goto out; 1053 1054 if (!IS_ELF(*hdr)) { 1055 error = ENOEXEC; 1056 goto out; 1057 } 1058 1059 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 1060 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 1061 link_elf_error(filename, "Unsupported file layout"); 1062 error = ENOEXEC; 1063 goto out; 1064 } 1065 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 1066 hdr->e_version != EV_CURRENT) { 1067 link_elf_error(filename, "Unsupported file version"); 1068 error = ENOEXEC; 1069 goto out; 1070 } 1071 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 1072 error = ENOSYS; 1073 goto out; 1074 } 1075 if (hdr->e_machine != ELF_TARG_MACH) { 1076 link_elf_error(filename, "Unsupported machine"); 1077 error = ENOEXEC; 1078 goto out; 1079 } 1080 1081 /* 1082 * We rely on the program header being in the first page. 1083 * This is not strictly required by the ABI specification, but 1084 * it seems to always true in practice. And, it simplifies 1085 * things considerably. 1086 */ 1087 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 1088 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 1089 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 1090 link_elf_error(filename, "Unreadable program headers"); 1091 1092 /* 1093 * Scan the program header entries, and save key information. 1094 * 1095 * We rely on there being exactly two load segments, text and data, 1096 * in that order. 1097 */ 1098 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 1099 phlimit = phdr + hdr->e_phnum; 1100 nsegs = 0; 1101 phdyn = NULL; 1102 while (phdr < phlimit) { 1103 switch (phdr->p_type) { 1104 case PT_LOAD: 1105 if (nsegs == MAXSEGS) { 1106 link_elf_error(filename, "Too many sections"); 1107 error = ENOEXEC; 1108 goto out; 1109 } 1110 /* 1111 * XXX: We just trust they come in right order ?? 1112 */ 1113 segs[nsegs] = phdr; 1114 ++nsegs; 1115 break; 1116 1117 case PT_DYNAMIC: 1118 phdyn = phdr; 1119 break; 1120 1121 case PT_INTERP: 1122 error = ENOSYS; 1123 goto out; 1124 } 1125 1126 ++phdr; 1127 } 1128 if (phdyn == NULL) { 1129 link_elf_error(filename, "Object is not dynamically-linked"); 1130 error = ENOEXEC; 1131 goto out; 1132 } 1133 if (nsegs == 0) { 1134 link_elf_error(filename, "No sections"); 1135 error = ENOEXEC; 1136 goto out; 1137 } 1138 1139 /* 1140 * Allocate the entire address space of the object, to stake 1141 * out our contiguous region, and to establish the base 1142 * address for relocation. 1143 */ 1144 base_vaddr = trunc_page(segs[0]->p_vaddr); 1145 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 1146 segs[nsegs - 1]->p_memsz); 1147 mapsize = base_vlimit - base_vaddr; 1148 1149 lf = linker_make_file(filename, &link_elf_class); 1150 if (lf == NULL) { 1151 error = ENOMEM; 1152 goto out; 1153 } 1154 1155 ef = (elf_file_t) lf; 1156 #ifdef SPARSE_MAPPING 1157 ef->object = vm_pager_allocate(OBJT_PHYS, NULL, mapsize, VM_PROT_ALL, 1158 0, thread0.td_ucred); 1159 if (ef->object == NULL) { 1160 error = ENOMEM; 1161 goto out; 1162 } 1163 #ifdef __amd64__ 1164 mapbase = (caddr_t)KERNBASE; 1165 #else 1166 mapbase = (caddr_t)vm_map_min(kernel_map); 1167 #endif 1168 /* 1169 * Mapping protections are downgraded after relocation processing. 1170 */ 1171 error = vm_map_find(kernel_map, ef->object, 0, 1172 (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE, 1173 VM_PROT_ALL, VM_PROT_ALL, 0); 1174 if (error != 0) { 1175 vm_object_deallocate(ef->object); 1176 ef->object = NULL; 1177 goto out; 1178 } 1179 #else 1180 mapbase = malloc_exec(mapsize, M_LINKER, M_WAITOK); 1181 #endif 1182 ef->address = mapbase; 1183 1184 /* 1185 * Read the text and data sections and zero the bss. 1186 */ 1187 for (i = 0; i < nsegs; i++) { 1188 segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 1189 1190 #ifdef SPARSE_MAPPING 1191 /* 1192 * Consecutive segments may have different mapping permissions, 1193 * so be strict and verify that their mappings do not overlap. 1194 */ 1195 if (((vm_offset_t)segbase & PAGE_MASK) != 0) { 1196 error = EINVAL; 1197 goto out; 1198 } 1199 1200 error = vm_map_wire(kernel_map, 1201 (vm_offset_t)segbase, 1202 (vm_offset_t)segbase + round_page(segs[i]->p_memsz), 1203 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 1204 if (error != KERN_SUCCESS) { 1205 error = ENOMEM; 1206 goto out; 1207 } 1208 #endif 1209 1210 error = vn_rdwr(UIO_READ, nd.ni_vp, 1211 segbase, segs[i]->p_filesz, segs[i]->p_offset, 1212 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1213 &resid, td); 1214 if (error != 0) 1215 goto out; 1216 bzero(segbase + segs[i]->p_filesz, 1217 segs[i]->p_memsz - segs[i]->p_filesz); 1218 } 1219 1220 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 1221 1222 lf->address = ef->address; 1223 lf->size = mapsize; 1224 1225 error = parse_dynamic(ef); 1226 if (error != 0) 1227 goto out; 1228 error = parse_dpcpu(ef); 1229 if (error != 0) 1230 goto out; 1231 #ifdef VIMAGE 1232 error = parse_vnet(ef); 1233 if (error != 0) 1234 goto out; 1235 #endif 1236 link_elf_reloc_local(lf); 1237 1238 VOP_UNLOCK(nd.ni_vp); 1239 error = linker_load_dependencies(lf); 1240 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 1241 if (error != 0) 1242 goto out; 1243 error = relocate_file(ef); 1244 if (error != 0) 1245 goto out; 1246 1247 #ifdef SPARSE_MAPPING 1248 /* 1249 * Downgrade permissions on text segment mappings now that relocation 1250 * processing is complete. Restrict permissions on read-only segments. 1251 */ 1252 for (i = 0; i < nsegs; i++) { 1253 vm_prot_t prot; 1254 1255 if (segs[i]->p_type != PT_LOAD) 1256 continue; 1257 1258 prot = VM_PROT_READ; 1259 if ((segs[i]->p_flags & PF_W) != 0) 1260 prot |= VM_PROT_WRITE; 1261 if ((segs[i]->p_flags & PF_X) != 0) 1262 prot |= VM_PROT_EXECUTE; 1263 segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 1264 error = vm_map_protect(kernel_map, 1265 (vm_offset_t)segbase, 1266 (vm_offset_t)segbase + round_page(segs[i]->p_memsz), 1267 prot, 0, VM_MAP_PROTECT_SET_PROT); 1268 if (error != KERN_SUCCESS) { 1269 error = ENOMEM; 1270 goto out; 1271 } 1272 } 1273 #endif 1274 1275 /* 1276 * Try and load the symbol table if it's present. (you can 1277 * strip it!) 1278 */ 1279 nbytes = hdr->e_shnum * hdr->e_shentsize; 1280 if (nbytes == 0 || hdr->e_shoff == 0) 1281 goto nosyms; 1282 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1283 error = vn_rdwr(UIO_READ, nd.ni_vp, 1284 (caddr_t)shdr, nbytes, hdr->e_shoff, 1285 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1286 &resid, td); 1287 if (error != 0) 1288 goto out; 1289 1290 /* Read section string table */ 1291 shstrindex = hdr->e_shstrndx; 1292 if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB && 1293 shdr[shstrindex].sh_size != 0) { 1294 nbytes = shdr[shstrindex].sh_size; 1295 shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1296 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes, 1297 shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 1298 td->td_ucred, NOCRED, &resid, td); 1299 if (error) 1300 goto out; 1301 } 1302 1303 symtabindex = -1; 1304 symstrindex = -1; 1305 for (i = 0; i < hdr->e_shnum; i++) { 1306 if (shdr[i].sh_type == SHT_SYMTAB) { 1307 symtabindex = i; 1308 symstrindex = shdr[i].sh_link; 1309 } else if (shstrs != NULL && shdr[i].sh_name != 0 && 1310 strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) { 1311 /* Record relocated address and size of .ctors. */ 1312 lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr; 1313 lf->ctors_size = shdr[i].sh_size; 1314 } 1315 } 1316 if (symtabindex < 0 || symstrindex < 0) 1317 goto nosyms; 1318 1319 symcnt = shdr[symtabindex].sh_size; 1320 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1321 strcnt = shdr[symstrindex].sh_size; 1322 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1323 1324 error = vn_rdwr(UIO_READ, nd.ni_vp, 1325 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1326 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1327 &resid, td); 1328 if (error != 0) 1329 goto out; 1330 error = vn_rdwr(UIO_READ, nd.ni_vp, 1331 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1332 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1333 &resid, td); 1334 if (error != 0) 1335 goto out; 1336 1337 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1338 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1339 ef->ddbstrcnt = strcnt; 1340 ef->ddbstrtab = ef->strbase; 1341 1342 nosyms: 1343 1344 #ifdef __arm__ 1345 link_elf_locate_exidx(lf, shdr, hdr->e_shnum); 1346 #endif 1347 1348 error = link_elf_link_common_finish(lf); 1349 if (error != 0) 1350 goto out; 1351 1352 *result = lf; 1353 1354 out: 1355 VOP_UNLOCK(nd.ni_vp); 1356 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1357 if (error != 0 && lf != NULL) 1358 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1359 free(shdr, M_LINKER); 1360 free(firstpage, M_LINKER); 1361 free(shstrs, M_LINKER); 1362 1363 return (error); 1364 } 1365 1366 Elf_Addr 1367 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1368 { 1369 elf_file_t ef; 1370 1371 KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class, 1372 ("elf_relocaddr: unexpected linker file %p", lf)); 1373 1374 ef = (elf_file_t)lf; 1375 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1376 return ((x - ef->pcpu_start) + ef->pcpu_base); 1377 #ifdef VIMAGE 1378 if (x >= ef->vnet_start && x < ef->vnet_stop) 1379 return ((x - ef->vnet_start) + ef->vnet_base); 1380 #endif 1381 return (x); 1382 } 1383 1384 static void 1385 link_elf_unload_file(linker_file_t file) 1386 { 1387 elf_file_t ef = (elf_file_t) file; 1388 1389 if (ef->pcpu_base != 0) { 1390 dpcpu_free((void *)ef->pcpu_base, 1391 ef->pcpu_stop - ef->pcpu_start); 1392 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1393 } 1394 #ifdef VIMAGE 1395 if (ef->vnet_base != 0) { 1396 vnet_data_free((void *)ef->vnet_base, 1397 ef->vnet_stop - ef->vnet_start); 1398 elf_set_delete(&set_vnet_list, ef->vnet_start); 1399 } 1400 #endif 1401 #ifdef GDB 1402 if (ef->gdb.l_ld != NULL) { 1403 GDB_STATE(RT_DELETE); 1404 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1405 link_elf_delete_gdb(&ef->gdb); 1406 GDB_STATE(RT_CONSISTENT); 1407 } 1408 #endif 1409 1410 /* Notify MD code that a module is being unloaded. */ 1411 elf_cpu_unload_file(file); 1412 1413 if (ef->preloaded) { 1414 link_elf_unload_preload(ef); 1415 return; 1416 } 1417 1418 #ifdef SPARSE_MAPPING 1419 if (ef->object != NULL) { 1420 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1421 (vm_offset_t) ef->address 1422 + (ef->object->size << PAGE_SHIFT)); 1423 } 1424 #else 1425 free(ef->address, M_LINKER); 1426 #endif 1427 free(ef->symbase, M_LINKER); 1428 free(ef->strbase, M_LINKER); 1429 free(ef->ctftab, M_LINKER); 1430 free(ef->ctfoff, M_LINKER); 1431 free(ef->typoff, M_LINKER); 1432 } 1433 1434 static void 1435 link_elf_unload_preload(elf_file_t ef) 1436 { 1437 /* 1438 * Reset mapping protections to their original state. This affects the 1439 * direct map alias of the module mapping as well. 1440 */ 1441 preload_protect_reset(ef, VM_PROT_RW); 1442 1443 if (ef->lf.pathname != NULL) 1444 preload_delete_name(ef->lf.pathname); 1445 } 1446 1447 static const char * 1448 symbol_name(elf_file_t ef, Elf_Size r_info) 1449 { 1450 const Elf_Sym *ref; 1451 1452 if (ELF_R_SYM(r_info)) { 1453 ref = ef->symtab + ELF_R_SYM(r_info); 1454 return (ef->strtab + ref->st_name); 1455 } 1456 return (NULL); 1457 } 1458 1459 static int 1460 symbol_type(elf_file_t ef, Elf_Size r_info) 1461 { 1462 const Elf_Sym *ref; 1463 1464 if (ELF_R_SYM(r_info)) { 1465 ref = ef->symtab + ELF_R_SYM(r_info); 1466 return (ELF_ST_TYPE(ref->st_info)); 1467 } 1468 return (STT_NOTYPE); 1469 } 1470 1471 static int 1472 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc, 1473 bool ifuncs) 1474 { 1475 const Elf_Rel *rel; 1476 const Elf_Rela *rela; 1477 const char *symname; 1478 1479 TSENTER(); 1480 #define APPLY_RELOCS(iter, tbl, tblsize, type) do { \ 1481 for ((iter) = (tbl); (iter) != NULL && \ 1482 (iter) < (tbl) + (tblsize) / sizeof(*(iter)); (iter)++) { \ 1483 if ((symbol_type(ef, (iter)->r_info) == \ 1484 STT_GNU_IFUNC || \ 1485 elf_is_ifunc_reloc((iter)->r_info)) != ifuncs) \ 1486 continue; \ 1487 if (reloc(&ef->lf, (Elf_Addr)ef->address, \ 1488 (iter), (type), lookup)) { \ 1489 symname = symbol_name(ef, (iter)->r_info); \ 1490 printf("link_elf: symbol %s undefined\n", \ 1491 symname); \ 1492 return (ENOENT); \ 1493 } \ 1494 } \ 1495 } while (0) 1496 1497 APPLY_RELOCS(rel, ef->rel, ef->relsize, ELF_RELOC_REL); 1498 TSENTER2("ef->rela"); 1499 APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA); 1500 TSEXIT2("ef->rela"); 1501 APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL); 1502 APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA); 1503 1504 #undef APPLY_RELOCS 1505 1506 TSEXIT(); 1507 return (0); 1508 } 1509 1510 static int 1511 relocate_file(elf_file_t ef) 1512 { 1513 int error; 1514 1515 error = relocate_file1(ef, elf_lookup, elf_reloc, false); 1516 if (error == 0) 1517 error = relocate_file1(ef, elf_lookup, elf_reloc, true); 1518 return (error); 1519 } 1520 1521 /* 1522 * SysV hash function for symbol table lookup. It is specified by the 1523 * System V ABI. 1524 */ 1525 static Elf32_Word 1526 elf_hash(const char *name) 1527 { 1528 const unsigned char *p = (const unsigned char *)name; 1529 Elf32_Word h = 0; 1530 1531 while (*p != '\0') { 1532 h = (h << 4) + *p++; 1533 h ^= (h >> 24) & 0xf0; 1534 } 1535 return (h & 0x0fffffff); 1536 } 1537 1538 static int 1539 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym, 1540 bool see_local) 1541 { 1542 elf_file_t ef = (elf_file_t) lf; 1543 unsigned long symnum; 1544 const Elf_Sym* symp; 1545 const char *strp; 1546 Elf32_Word hash; 1547 1548 /* If we don't have a hash, bail. */ 1549 if (ef->buckets == NULL || ef->nbuckets == 0) { 1550 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1551 return (ENOENT); 1552 } 1553 1554 /* First, search hashed global symbols */ 1555 hash = elf_hash(name); 1556 symnum = ef->buckets[hash % ef->nbuckets]; 1557 1558 while (symnum != STN_UNDEF) { 1559 if (symnum >= ef->nchains) { 1560 printf("%s: corrupt symbol table\n", __func__); 1561 return (ENOENT); 1562 } 1563 1564 symp = ef->symtab + symnum; 1565 if (symp->st_name == 0) { 1566 printf("%s: corrupt symbol table\n", __func__); 1567 return (ENOENT); 1568 } 1569 1570 strp = ef->strtab + symp->st_name; 1571 1572 if (strcmp(name, strp) == 0) { 1573 if (symp->st_shndx != SHN_UNDEF || 1574 (symp->st_value != 0 && 1575 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1576 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1577 if (see_local || 1578 ELF_ST_BIND(symp->st_info) != STB_LOCAL) { 1579 *sym = (c_linker_sym_t) symp; 1580 return (0); 1581 } 1582 } 1583 return (ENOENT); 1584 } 1585 1586 symnum = ef->chains[symnum]; 1587 } 1588 1589 return (ENOENT); 1590 } 1591 1592 static int 1593 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) 1594 { 1595 if (link_elf_leak_locals) 1596 return (link_elf_lookup_debug_symbol(lf, name, sym)); 1597 return (link_elf_lookup_symbol1(lf, name, sym, false)); 1598 } 1599 1600 static int 1601 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name, 1602 c_linker_sym_t *sym) 1603 { 1604 elf_file_t ef = (elf_file_t)lf; 1605 const Elf_Sym* symp; 1606 const char *strp; 1607 int i; 1608 1609 if (link_elf_lookup_symbol1(lf, name, sym, true) == 0) 1610 return (0); 1611 1612 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1613 strp = ef->ddbstrtab + symp->st_name; 1614 if (strcmp(name, strp) == 0) { 1615 if (symp->st_shndx != SHN_UNDEF || 1616 (symp->st_value != 0 && 1617 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1618 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) { 1619 *sym = (c_linker_sym_t) symp; 1620 return (0); 1621 } 1622 return (ENOENT); 1623 } 1624 } 1625 1626 return (ENOENT); 1627 } 1628 1629 static int 1630 link_elf_lookup_debug_symbol_ctf(linker_file_t lf, const char *name, 1631 c_linker_sym_t *sym, linker_ctf_t *lc) 1632 { 1633 elf_file_t ef = (elf_file_t)lf; 1634 const Elf_Sym *symp; 1635 const char *strp; 1636 int i; 1637 1638 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1639 strp = ef->ddbstrtab + symp->st_name; 1640 if (strcmp(name, strp) == 0) { 1641 if (symp->st_shndx != SHN_UNDEF || 1642 (symp->st_value != 0 && 1643 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1644 ELF_ST_TYPE(symp->st_info) == 1645 STT_GNU_IFUNC))) { 1646 *sym = (c_linker_sym_t)symp; 1647 break; 1648 } 1649 return (ENOENT); 1650 } 1651 } 1652 1653 /* Populate CTF info structure if symbol was found. */ 1654 return (i < ef->ddbsymcnt ? link_elf_ctf_get_ddb(lf, lc) : ENOENT); 1655 } 1656 1657 static void 1658 link_elf_ifunc_symbol_value(linker_file_t lf, caddr_t *valp, size_t *sizep) 1659 { 1660 c_linker_sym_t sym; 1661 elf_file_t ef; 1662 const Elf_Sym *es; 1663 caddr_t val; 1664 long off; 1665 1666 val = *valp; 1667 ef = (elf_file_t)lf; 1668 1669 /* Provide the value and size of the target symbol, if available. */ 1670 val = ((caddr_t (*)(void))val)(); 1671 if (link_elf_search_symbol(lf, val, &sym, &off) == 0 && off == 0) { 1672 es = (const Elf_Sym *)sym; 1673 *valp = (caddr_t)ef->address + es->st_value; 1674 *sizep = es->st_size; 1675 } else { 1676 *valp = val; 1677 *sizep = 0; 1678 } 1679 } 1680 1681 static int 1682 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym, 1683 linker_symval_t *symval, bool see_local) 1684 { 1685 elf_file_t ef; 1686 const Elf_Sym *es; 1687 caddr_t val; 1688 size_t size; 1689 1690 ef = (elf_file_t)lf; 1691 es = (const Elf_Sym *)sym; 1692 if (es >= ef->symtab && es < ef->symtab + ef->nchains) { 1693 if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL) 1694 return (ENOENT); 1695 symval->name = ef->strtab + es->st_name; 1696 val = (caddr_t)ef->address + es->st_value; 1697 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1698 link_elf_ifunc_symbol_value(lf, &val, &size); 1699 else 1700 size = es->st_size; 1701 symval->value = val; 1702 symval->size = size; 1703 return (0); 1704 } 1705 return (ENOENT); 1706 } 1707 1708 static int 1709 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1710 linker_symval_t *symval) 1711 { 1712 if (link_elf_leak_locals) 1713 return (link_elf_debug_symbol_values(lf, sym, symval)); 1714 return (link_elf_symbol_values1(lf, sym, symval, false)); 1715 } 1716 1717 static int 1718 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1719 linker_symval_t *symval) 1720 { 1721 elf_file_t ef = (elf_file_t)lf; 1722 const Elf_Sym *es = (const Elf_Sym *)sym; 1723 caddr_t val; 1724 size_t size; 1725 1726 if (link_elf_symbol_values1(lf, sym, symval, true) == 0) 1727 return (0); 1728 if (ef->symtab == ef->ddbsymtab) 1729 return (ENOENT); 1730 1731 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1732 symval->name = ef->ddbstrtab + es->st_name; 1733 val = (caddr_t)ef->address + es->st_value; 1734 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC) 1735 link_elf_ifunc_symbol_value(lf, &val, &size); 1736 else 1737 size = es->st_size; 1738 symval->value = val; 1739 symval->size = size; 1740 return (0); 1741 } 1742 return (ENOENT); 1743 } 1744 1745 static int 1746 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1747 c_linker_sym_t *sym, long *diffp) 1748 { 1749 elf_file_t ef = (elf_file_t)lf; 1750 u_long off = (uintptr_t)(void *)value; 1751 u_long diff = off; 1752 u_long st_value; 1753 const Elf_Sym *es; 1754 const Elf_Sym *best = NULL; 1755 int i; 1756 1757 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1758 if (es->st_name == 0) 1759 continue; 1760 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1761 if (off >= st_value) { 1762 if (off - st_value < diff) { 1763 diff = off - st_value; 1764 best = es; 1765 if (diff == 0) 1766 break; 1767 } else if (off - st_value == diff) { 1768 best = es; 1769 } 1770 } 1771 } 1772 if (best == NULL) 1773 *diffp = off; 1774 else 1775 *diffp = diff; 1776 *sym = (c_linker_sym_t) best; 1777 1778 return (0); 1779 } 1780 1781 /* 1782 * Look up a linker set on an ELF system. 1783 */ 1784 static int 1785 link_elf_lookup_set(linker_file_t lf, const char *name, 1786 void ***startp, void ***stopp, int *countp) 1787 { 1788 c_linker_sym_t sym; 1789 linker_symval_t symval; 1790 char *setsym; 1791 void **start, **stop; 1792 int len, error = 0, count; 1793 1794 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1795 setsym = malloc(len, M_LINKER, M_WAITOK); 1796 1797 /* get address of first entry */ 1798 snprintf(setsym, len, "%s%s", "__start_set_", name); 1799 error = link_elf_lookup_symbol(lf, setsym, &sym); 1800 if (error != 0) 1801 goto out; 1802 link_elf_symbol_values(lf, sym, &symval); 1803 if (symval.value == 0) { 1804 error = ESRCH; 1805 goto out; 1806 } 1807 start = (void **)symval.value; 1808 1809 /* get address of last entry */ 1810 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1811 error = link_elf_lookup_symbol(lf, setsym, &sym); 1812 if (error != 0) 1813 goto out; 1814 link_elf_symbol_values(lf, sym, &symval); 1815 if (symval.value == 0) { 1816 error = ESRCH; 1817 goto out; 1818 } 1819 stop = (void **)symval.value; 1820 1821 /* and the number of entries */ 1822 count = stop - start; 1823 1824 /* and copy out */ 1825 if (startp != NULL) 1826 *startp = start; 1827 if (stopp != NULL) 1828 *stopp = stop; 1829 if (countp != NULL) 1830 *countp = count; 1831 1832 out: 1833 free(setsym, M_LINKER); 1834 return (error); 1835 } 1836 1837 static int 1838 link_elf_each_function_name(linker_file_t file, 1839 int (*callback)(const char *, void *), void *opaque) 1840 { 1841 elf_file_t ef = (elf_file_t)file; 1842 const Elf_Sym *symp; 1843 int i, error; 1844 1845 /* Exhaustive search */ 1846 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1847 if (symp->st_value != 0 && 1848 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1849 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1850 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1851 if (error != 0) 1852 return (error); 1853 } 1854 } 1855 return (0); 1856 } 1857 1858 static int 1859 link_elf_each_function_nameval(linker_file_t file, 1860 linker_function_nameval_callback_t callback, void *opaque) 1861 { 1862 linker_symval_t symval; 1863 elf_file_t ef = (elf_file_t)file; 1864 const Elf_Sym *symp; 1865 int i, error; 1866 1867 /* Exhaustive search */ 1868 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1869 if (symp->st_value != 0 && 1870 (ELF_ST_TYPE(symp->st_info) == STT_FUNC || 1871 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) { 1872 error = link_elf_debug_symbol_values(file, 1873 (c_linker_sym_t) symp, &symval); 1874 if (error == 0) 1875 error = callback(file, i, &symval, opaque); 1876 if (error != 0) 1877 return (error); 1878 } 1879 } 1880 return (0); 1881 } 1882 1883 const Elf_Sym * 1884 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1885 { 1886 elf_file_t ef = (elf_file_t)lf; 1887 1888 if (symidx >= ef->nchains) 1889 return (NULL); 1890 return (ef->symtab + symidx); 1891 } 1892 1893 const char * 1894 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1895 { 1896 elf_file_t ef = (elf_file_t)lf; 1897 const Elf_Sym *sym; 1898 1899 if (symidx >= ef->nchains) 1900 return (NULL); 1901 sym = ef->symtab + symidx; 1902 return (ef->strtab + sym->st_name); 1903 } 1904 1905 /* 1906 * Symbol lookup function that can be used when the symbol index is known (ie 1907 * in relocations). It uses the symbol index instead of doing a fully fledged 1908 * hash table based lookup when such is valid. For example for local symbols. 1909 * This is not only more efficient, it's also more correct. It's not always 1910 * the case that the symbol can be found through the hash table. 1911 */ 1912 static int 1913 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) 1914 { 1915 elf_file_t ef = (elf_file_t)lf; 1916 const Elf_Sym *sym; 1917 const char *symbol; 1918 Elf_Addr addr, start, base; 1919 1920 /* Don't even try to lookup the symbol if the index is bogus. */ 1921 if (symidx >= ef->nchains) { 1922 *res = 0; 1923 return (EINVAL); 1924 } 1925 1926 sym = ef->symtab + symidx; 1927 1928 /* 1929 * Don't do a full lookup when the symbol is local. It may even 1930 * fail because it may not be found through the hash table. 1931 */ 1932 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1933 /* Force lookup failure when we have an insanity. */ 1934 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) { 1935 *res = 0; 1936 return (EINVAL); 1937 } 1938 *res = ((Elf_Addr)ef->address + sym->st_value); 1939 return (0); 1940 } 1941 1942 /* 1943 * XXX we can avoid doing a hash table based lookup for global 1944 * symbols as well. This however is not always valid, so we'll 1945 * just do it the hard way for now. Performance tweaks can 1946 * always be added. 1947 */ 1948 1949 symbol = ef->strtab + sym->st_name; 1950 1951 /* Force a lookup failure if the symbol name is bogus. */ 1952 if (*symbol == 0) { 1953 *res = 0; 1954 return (EINVAL); 1955 } 1956 1957 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1958 if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) { 1959 *res = 0; 1960 return (EINVAL); 1961 } 1962 1963 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1964 addr = addr - start + base; 1965 #ifdef VIMAGE 1966 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1967 addr = addr - start + base; 1968 #endif 1969 *res = addr; 1970 return (0); 1971 } 1972 1973 static void 1974 link_elf_reloc_local(linker_file_t lf) 1975 { 1976 const Elf_Rel *rellim; 1977 const Elf_Rel *rel; 1978 const Elf_Rela *relalim; 1979 const Elf_Rela *rela; 1980 elf_file_t ef = (elf_file_t)lf; 1981 1982 /* Perform relocations without addend if there are any: */ 1983 if ((rel = ef->rel) != NULL) { 1984 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1985 while (rel < rellim) { 1986 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1987 ELF_RELOC_REL, elf_lookup); 1988 rel++; 1989 } 1990 } 1991 1992 /* Perform relocations with addend if there are any: */ 1993 if ((rela = ef->rela) != NULL) { 1994 relalim = (const Elf_Rela *) 1995 ((const char *)ef->rela + ef->relasize); 1996 while (rela < relalim) { 1997 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1998 ELF_RELOC_RELA, elf_lookup); 1999 rela++; 2000 } 2001 } 2002 } 2003 2004 static long 2005 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 2006 { 2007 elf_file_t ef = (elf_file_t)lf; 2008 2009 *symtab = ef->ddbsymtab; 2010 2011 if (*symtab == NULL) 2012 return (0); 2013 2014 return (ef->ddbsymcnt); 2015 } 2016 2017 static long 2018 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 2019 { 2020 elf_file_t ef = (elf_file_t)lf; 2021 2022 *strtab = ef->ddbstrtab; 2023 2024 if (*strtab == NULL) 2025 return (0); 2026 2027 return (ef->ddbstrcnt); 2028 } 2029 2030 #ifdef VIMAGE 2031 static void 2032 link_elf_propagate_vnets(linker_file_t lf) 2033 { 2034 elf_file_t ef = (elf_file_t)lf; 2035 int size; 2036 2037 if (ef->vnet_base != 0) { 2038 size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start; 2039 vnet_data_copy((void *)ef->vnet_base, size); 2040 } 2041 } 2042 #endif 2043 2044 #if !defined(__riscv) 2045 /* 2046 * Use this lookup routine when performing relocations early during boot. 2047 * The generic lookup routine depends on kobj, which is not initialized 2048 * at that point. 2049 */ 2050 static int 2051 elf_lookup_ifunc(linker_file_t lf, Elf_Size symidx, int deps __unused, 2052 Elf_Addr *res) 2053 { 2054 elf_file_t ef; 2055 const Elf_Sym *symp; 2056 caddr_t val; 2057 2058 ef = (elf_file_t)lf; 2059 symp = ef->symtab + symidx; 2060 if (ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC) { 2061 val = (caddr_t)ef->address + symp->st_value; 2062 *res = ((Elf_Addr (*)(void))val)(); 2063 return (0); 2064 } 2065 return (ENOENT); 2066 } 2067 2068 void 2069 link_elf_ireloc(void) 2070 { 2071 struct elf_file eff; 2072 elf_file_t ef; 2073 2074 TSENTER(); 2075 ef = &eff; 2076 2077 bzero_early(ef, sizeof(*ef)); 2078 2079 ef->modptr = preload_kmdp; 2080 ef->dynamic = (Elf_Dyn *)&_DYNAMIC; 2081 2082 #ifdef RELOCATABLE_KERNEL 2083 ef->address = (caddr_t) (__startkernel - KERNBASE); 2084 #else 2085 ef->address = 0; 2086 #endif 2087 parse_dynamic(ef); 2088 2089 link_elf_preload_parse_symbols(ef); 2090 relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true); 2091 TSEXIT(); 2092 } 2093 2094 #if defined(__aarch64__) || defined(__amd64__) 2095 void 2096 link_elf_late_ireloc(void) 2097 { 2098 elf_file_t ef; 2099 2100 KASSERT(linker_kernel_file != NULL, 2101 ("link_elf_late_ireloc: No kernel linker file found")); 2102 ef = (elf_file_t)linker_kernel_file; 2103 2104 relocate_file1(ef, elf_lookup_ifunc, elf_reloc_late, true); 2105 } 2106 #endif 2107 #endif 2108