1 /*- 2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 4 * Copyright 2009, 2010, 2011 Konstantin Belousov <kib@FreeBSD.ORG>. 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 ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 /* 31 * Dynamic linker for ELF. 32 * 33 * John Polstra <jdp@polstra.com>. 34 */ 35 36 #ifndef __GNUC__ 37 #error "GCC is needed to compile this file" 38 #endif 39 40 #include <sys/param.h> 41 #include <sys/mount.h> 42 #include <sys/mman.h> 43 #include <sys/stat.h> 44 #include <sys/sysctl.h> 45 #include <sys/uio.h> 46 #include <sys/utsname.h> 47 #include <sys/ktrace.h> 48 49 #include <dlfcn.h> 50 #include <err.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <stdarg.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 59 #include "debug.h" 60 #include "rtld.h" 61 #include "libmap.h" 62 #include "rtld_tls.h" 63 #include "rtld_printf.h" 64 65 #ifndef COMPAT_32BIT 66 #define PATH_RTLD "/libexec/ld-elf.so.1" 67 #else 68 #define PATH_RTLD "/libexec/ld-elf32.so.1" 69 #endif 70 71 /* Types. */ 72 typedef void (*func_ptr_type)(); 73 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 74 75 /* 76 * Function declarations. 77 */ 78 static const char *basename(const char *); 79 static void die(void) __dead2; 80 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 81 const Elf_Dyn **); 82 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *); 83 static void digest_dynamic(Obj_Entry *, int); 84 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 85 static Obj_Entry *dlcheck(void *); 86 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 87 int lo_flags, int mode); 88 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 89 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 90 static bool donelist_check(DoneList *, const Obj_Entry *); 91 static void errmsg_restore(char *); 92 static char *errmsg_save(void); 93 static void *fill_search_info(const char *, size_t, void *); 94 static char *find_library(const char *, const Obj_Entry *); 95 static const char *gethints(void); 96 static void init_dag(Obj_Entry *); 97 static void init_rtld(caddr_t, Elf_Auxinfo **); 98 static void initlist_add_neededs(Needed_Entry *, Objlist *); 99 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 100 static void linkmap_add(Obj_Entry *); 101 static void linkmap_delete(Obj_Entry *); 102 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 103 static void unload_filtees(Obj_Entry *); 104 static int load_needed_objects(Obj_Entry *, int); 105 static int load_preload_objects(void); 106 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 107 static void map_stacks_exec(RtldLockState *); 108 static Obj_Entry *obj_from_addr(const void *); 109 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 110 static void objlist_call_init(Objlist *, RtldLockState *); 111 static void objlist_clear(Objlist *); 112 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 113 static void objlist_init(Objlist *); 114 static void objlist_push_head(Objlist *, Obj_Entry *); 115 static void objlist_push_tail(Objlist *, Obj_Entry *); 116 static void objlist_remove(Objlist *, Obj_Entry *); 117 static void *path_enumerate(const char *, path_enum_proc, void *); 118 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, RtldLockState *); 119 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 120 RtldLockState *lockstate); 121 static int rtld_dirname(const char *, char *); 122 static int rtld_dirname_abs(const char *, char *); 123 static void *rtld_dlopen(const char *name, int fd, int mode); 124 static void rtld_exit(void); 125 static char *search_library_path(const char *, const char *); 126 static const void **get_program_var_addr(const char *, RtldLockState *); 127 static void set_program_var(const char *, const void *); 128 static int symlook_default(SymLook *, const Obj_Entry *refobj); 129 static int symlook_global(SymLook *, DoneList *); 130 static void symlook_init_from_req(SymLook *, const SymLook *); 131 static int symlook_list(SymLook *, const Objlist *, DoneList *); 132 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 133 static int symlook_obj1(SymLook *, const Obj_Entry *); 134 static void trace_loaded_objects(Obj_Entry *); 135 static void unlink_object(Obj_Entry *); 136 static void unload_object(Obj_Entry *); 137 static void unref_dag(Obj_Entry *); 138 static void ref_dag(Obj_Entry *); 139 static int origin_subst_one(char **, const char *, const char *, 140 const char *, char *); 141 static char *origin_subst(const char *, const char *); 142 static int rtld_verify_versions(const Objlist *); 143 static int rtld_verify_object_versions(Obj_Entry *); 144 static void object_add_name(Obj_Entry *, const char *); 145 static int object_match_name(const Obj_Entry *, const char *); 146 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 147 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 148 struct dl_phdr_info *phdr_info); 149 150 void r_debug_state(struct r_debug *, struct link_map *) __noinline; 151 152 /* 153 * Data declarations. 154 */ 155 static char *error_message; /* Message for dlerror(), or NULL */ 156 struct r_debug r_debug; /* for GDB; */ 157 static bool libmap_disable; /* Disable libmap */ 158 static bool ld_loadfltr; /* Immediate filters processing */ 159 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 160 static bool trust; /* False for setuid and setgid programs */ 161 static bool dangerous_ld_env; /* True if environment variables have been 162 used to affect the libraries loaded */ 163 static char *ld_bind_now; /* Environment variable for immediate binding */ 164 static char *ld_debug; /* Environment variable for debugging */ 165 static char *ld_library_path; /* Environment variable for search path */ 166 static char *ld_preload; /* Environment variable for libraries to 167 load first */ 168 static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 169 static char *ld_tracing; /* Called from ldd to print libs */ 170 static char *ld_utrace; /* Use utrace() to log events. */ 171 static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 172 static Obj_Entry **obj_tail; /* Link field of last object in list */ 173 static Obj_Entry *obj_main; /* The main program shared object */ 174 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 175 static unsigned int obj_count; /* Number of objects in obj_list */ 176 static unsigned int obj_loads; /* Number of objects in obj_list */ 177 178 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 179 STAILQ_HEAD_INITIALIZER(list_global); 180 static Objlist list_main = /* Objects loaded at program startup */ 181 STAILQ_HEAD_INITIALIZER(list_main); 182 static Objlist list_fini = /* Objects needing fini() calls */ 183 STAILQ_HEAD_INITIALIZER(list_fini); 184 185 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 186 187 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 188 189 extern Elf_Dyn _DYNAMIC; 190 #pragma weak _DYNAMIC 191 #ifndef RTLD_IS_DYNAMIC 192 #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 193 #endif 194 195 int osreldate, pagesize; 196 197 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 198 static int max_stack_flags; 199 200 /* 201 * Global declarations normally provided by crt1. The dynamic linker is 202 * not built with crt1, so we have to provide them ourselves. 203 */ 204 char *__progname; 205 char **environ; 206 207 /* 208 * Globals to control TLS allocation. 209 */ 210 size_t tls_last_offset; /* Static TLS offset of last module */ 211 size_t tls_last_size; /* Static TLS size of last module */ 212 size_t tls_static_space; /* Static TLS space allocated */ 213 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 214 int tls_max_index = 1; /* Largest module index allocated */ 215 216 /* 217 * Fill in a DoneList with an allocation large enough to hold all of 218 * the currently-loaded objects. Keep this as a macro since it calls 219 * alloca and we want that to occur within the scope of the caller. 220 */ 221 #define donelist_init(dlp) \ 222 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 223 assert((dlp)->objs != NULL), \ 224 (dlp)->num_alloc = obj_count, \ 225 (dlp)->num_used = 0) 226 227 #define UTRACE_DLOPEN_START 1 228 #define UTRACE_DLOPEN_STOP 2 229 #define UTRACE_DLCLOSE_START 3 230 #define UTRACE_DLCLOSE_STOP 4 231 #define UTRACE_LOAD_OBJECT 5 232 #define UTRACE_UNLOAD_OBJECT 6 233 #define UTRACE_ADD_RUNDEP 7 234 #define UTRACE_PRELOAD_FINISHED 8 235 #define UTRACE_INIT_CALL 9 236 #define UTRACE_FINI_CALL 10 237 238 struct utrace_rtld { 239 char sig[4]; /* 'RTLD' */ 240 int event; 241 void *handle; 242 void *mapbase; /* Used for 'parent' and 'init/fini' */ 243 size_t mapsize; 244 int refcnt; /* Used for 'mode' */ 245 char name[MAXPATHLEN]; 246 }; 247 248 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 249 if (ld_utrace != NULL) \ 250 ld_utrace_log(e, h, mb, ms, r, n); \ 251 } while (0) 252 253 static void 254 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 255 int refcnt, const char *name) 256 { 257 struct utrace_rtld ut; 258 259 ut.sig[0] = 'R'; 260 ut.sig[1] = 'T'; 261 ut.sig[2] = 'L'; 262 ut.sig[3] = 'D'; 263 ut.event = event; 264 ut.handle = handle; 265 ut.mapbase = mapbase; 266 ut.mapsize = mapsize; 267 ut.refcnt = refcnt; 268 bzero(ut.name, sizeof(ut.name)); 269 if (name) 270 strlcpy(ut.name, name, sizeof(ut.name)); 271 utrace(&ut, sizeof(ut)); 272 } 273 274 /* 275 * Main entry point for dynamic linking. The first argument is the 276 * stack pointer. The stack is expected to be laid out as described 277 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 278 * Specifically, the stack pointer points to a word containing 279 * ARGC. Following that in the stack is a null-terminated sequence 280 * of pointers to argument strings. Then comes a null-terminated 281 * sequence of pointers to environment strings. Finally, there is a 282 * sequence of "auxiliary vector" entries. 283 * 284 * The second argument points to a place to store the dynamic linker's 285 * exit procedure pointer and the third to a place to store the main 286 * program's object. 287 * 288 * The return value is the main program's entry point. 289 */ 290 func_ptr_type 291 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 292 { 293 Elf_Auxinfo *aux_info[AT_COUNT]; 294 int i; 295 int argc; 296 char **argv; 297 char **env; 298 Elf_Auxinfo *aux; 299 Elf_Auxinfo *auxp; 300 const char *argv0; 301 Objlist_Entry *entry; 302 Obj_Entry *obj; 303 Obj_Entry **preload_tail; 304 Objlist initlist; 305 RtldLockState lockstate; 306 307 /* 308 * On entry, the dynamic linker itself has not been relocated yet. 309 * Be very careful not to reference any global data until after 310 * init_rtld has returned. It is OK to reference file-scope statics 311 * and string constants, and to call static and global functions. 312 */ 313 314 /* Find the auxiliary vector on the stack. */ 315 argc = *sp++; 316 argv = (char **) sp; 317 sp += argc + 1; /* Skip over arguments and NULL terminator */ 318 env = (char **) sp; 319 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 320 ; 321 aux = (Elf_Auxinfo *) sp; 322 323 /* Digest the auxiliary vector. */ 324 for (i = 0; i < AT_COUNT; i++) 325 aux_info[i] = NULL; 326 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 327 if (auxp->a_type < AT_COUNT) 328 aux_info[auxp->a_type] = auxp; 329 } 330 331 /* Initialize and relocate ourselves. */ 332 assert(aux_info[AT_BASE] != NULL); 333 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 334 335 __progname = obj_rtld.path; 336 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 337 environ = env; 338 339 trust = !issetugid(); 340 341 ld_bind_now = getenv(LD_ "BIND_NOW"); 342 /* 343 * If the process is tainted, then we un-set the dangerous environment 344 * variables. The process will be marked as tainted until setuid(2) 345 * is called. If any child process calls setuid(2) we do not want any 346 * future processes to honor the potentially un-safe variables. 347 */ 348 if (!trust) { 349 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 350 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 351 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 352 unsetenv(LD_ "LOADFLTR")) { 353 _rtld_error("environment corrupt; aborting"); 354 die(); 355 } 356 } 357 ld_debug = getenv(LD_ "DEBUG"); 358 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 359 libmap_override = getenv(LD_ "LIBMAP"); 360 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 361 ld_preload = getenv(LD_ "PRELOAD"); 362 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 363 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 364 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 365 (ld_library_path != NULL) || (ld_preload != NULL) || 366 (ld_elf_hints_path != NULL) || ld_loadfltr; 367 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 368 ld_utrace = getenv(LD_ "UTRACE"); 369 370 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 371 ld_elf_hints_path = _PATH_ELF_HINTS; 372 373 if (ld_debug != NULL && *ld_debug != '\0') 374 debug = 1; 375 dbg("%s is initialized, base address = %p", __progname, 376 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 377 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 378 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 379 380 dbg("initializing thread locks"); 381 lockdflt_init(); 382 383 /* 384 * Load the main program, or process its program header if it is 385 * already loaded. 386 */ 387 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 388 int fd = aux_info[AT_EXECFD]->a_un.a_val; 389 dbg("loading main program"); 390 obj_main = map_object(fd, argv0, NULL); 391 close(fd); 392 if (obj_main == NULL) 393 die(); 394 max_stack_flags = obj->stack_flags; 395 } else { /* Main program already loaded. */ 396 const Elf_Phdr *phdr; 397 int phnum; 398 caddr_t entry; 399 400 dbg("processing main program's program header"); 401 assert(aux_info[AT_PHDR] != NULL); 402 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 403 assert(aux_info[AT_PHNUM] != NULL); 404 phnum = aux_info[AT_PHNUM]->a_un.a_val; 405 assert(aux_info[AT_PHENT] != NULL); 406 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 407 assert(aux_info[AT_ENTRY] != NULL); 408 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 409 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 410 die(); 411 } 412 413 if (aux_info[AT_EXECPATH] != 0) { 414 char *kexecpath; 415 char buf[MAXPATHLEN]; 416 417 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 418 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 419 if (kexecpath[0] == '/') 420 obj_main->path = kexecpath; 421 else if (getcwd(buf, sizeof(buf)) == NULL || 422 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 423 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 424 obj_main->path = xstrdup(argv0); 425 else 426 obj_main->path = xstrdup(buf); 427 } else { 428 dbg("No AT_EXECPATH"); 429 obj_main->path = xstrdup(argv0); 430 } 431 dbg("obj_main path %s", obj_main->path); 432 obj_main->mainprog = true; 433 434 if (aux_info[AT_STACKPROT] != NULL && 435 aux_info[AT_STACKPROT]->a_un.a_val != 0) 436 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 437 438 /* 439 * Get the actual dynamic linker pathname from the executable if 440 * possible. (It should always be possible.) That ensures that 441 * gdb will find the right dynamic linker even if a non-standard 442 * one is being used. 443 */ 444 if (obj_main->interp != NULL && 445 strcmp(obj_main->interp, obj_rtld.path) != 0) { 446 free(obj_rtld.path); 447 obj_rtld.path = xstrdup(obj_main->interp); 448 __progname = obj_rtld.path; 449 } 450 451 digest_dynamic(obj_main, 0); 452 453 linkmap_add(obj_main); 454 linkmap_add(&obj_rtld); 455 456 /* Link the main program into the list of objects. */ 457 *obj_tail = obj_main; 458 obj_tail = &obj_main->next; 459 obj_count++; 460 obj_loads++; 461 /* Make sure we don't call the main program's init and fini functions. */ 462 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 463 464 /* Initialize a fake symbol for resolving undefined weak references. */ 465 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 466 sym_zero.st_shndx = SHN_UNDEF; 467 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 468 469 if (!libmap_disable) 470 libmap_disable = (bool)lm_init(libmap_override); 471 472 dbg("loading LD_PRELOAD libraries"); 473 if (load_preload_objects() == -1) 474 die(); 475 preload_tail = obj_tail; 476 477 dbg("loading needed objects"); 478 if (load_needed_objects(obj_main, 0) == -1) 479 die(); 480 481 /* Make a list of all objects loaded at startup. */ 482 for (obj = obj_list; obj != NULL; obj = obj->next) { 483 objlist_push_tail(&list_main, obj); 484 obj->refcount++; 485 } 486 487 dbg("checking for required versions"); 488 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 489 die(); 490 491 if (ld_tracing) { /* We're done */ 492 trace_loaded_objects(obj_main); 493 exit(0); 494 } 495 496 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 497 dump_relocations(obj_main); 498 exit (0); 499 } 500 501 /* 502 * Processing tls relocations requires having the tls offsets 503 * initialized. Prepare offsets before starting initial 504 * relocation processing. 505 */ 506 dbg("initializing initial thread local storage offsets"); 507 STAILQ_FOREACH(entry, &list_main, link) { 508 /* 509 * Allocate all the initial objects out of the static TLS 510 * block even if they didn't ask for it. 511 */ 512 allocate_tls_offset(entry->obj); 513 } 514 515 if (relocate_objects(obj_main, 516 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, NULL) == -1) 517 die(); 518 519 dbg("doing copy relocations"); 520 if (do_copy_relocations(obj_main) == -1) 521 die(); 522 523 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 524 dump_relocations(obj_main); 525 exit (0); 526 } 527 528 /* 529 * Setup TLS for main thread. This must be done after the 530 * relocations are processed, since tls initialization section 531 * might be the subject for relocations. 532 */ 533 dbg("initializing initial thread local storage"); 534 allocate_initial_tls(obj_list); 535 536 dbg("initializing key program variables"); 537 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 538 set_program_var("environ", env); 539 set_program_var("__elf_aux_vector", aux); 540 541 /* Make a list of init functions to call. */ 542 objlist_init(&initlist); 543 initlist_add_objects(obj_list, preload_tail, &initlist); 544 545 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 546 547 map_stacks_exec(NULL); 548 549 dbg("resolving ifuncs"); 550 if (resolve_objects_ifunc(obj_main, 551 ld_bind_now != NULL && *ld_bind_now != '\0', NULL) == -1) 552 die(); 553 554 wlock_acquire(rtld_bind_lock, &lockstate); 555 objlist_call_init(&initlist, &lockstate); 556 objlist_clear(&initlist); 557 dbg("loading filtees"); 558 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 559 if (ld_loadfltr || obj->z_loadfltr) 560 load_filtees(obj, 0, &lockstate); 561 } 562 lock_release(rtld_bind_lock, &lockstate); 563 564 dbg("transferring control to program entry point = %p", obj_main->entry); 565 566 /* Return the exit procedure and the program entry point. */ 567 *exit_proc = rtld_exit; 568 *objp = obj_main; 569 return (func_ptr_type) obj_main->entry; 570 } 571 572 void * 573 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 574 { 575 void *ptr; 576 Elf_Addr target; 577 578 ptr = (void *)make_function_pointer(def, obj); 579 target = ((Elf_Addr (*)(void))ptr)(); 580 return ((void *)target); 581 } 582 583 Elf_Addr 584 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 585 { 586 const Elf_Rel *rel; 587 const Elf_Sym *def; 588 const Obj_Entry *defobj; 589 Elf_Addr *where; 590 Elf_Addr target; 591 RtldLockState lockstate; 592 593 rlock_acquire(rtld_bind_lock, &lockstate); 594 if (sigsetjmp(lockstate.env, 0) != 0) 595 lock_upgrade(rtld_bind_lock, &lockstate); 596 if (obj->pltrel) 597 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 598 else 599 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 600 601 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 602 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 603 &lockstate); 604 if (def == NULL) 605 die(); 606 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 607 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 608 else 609 target = (Elf_Addr)(defobj->relocbase + def->st_value); 610 611 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 612 defobj->strtab + def->st_name, basename(obj->path), 613 (void *)target, basename(defobj->path)); 614 615 /* 616 * Write the new contents for the jmpslot. Note that depending on 617 * architecture, the value which we need to return back to the 618 * lazy binding trampoline may or may not be the target 619 * address. The value returned from reloc_jmpslot() is the value 620 * that the trampoline needs. 621 */ 622 target = reloc_jmpslot(where, target, defobj, obj, rel); 623 lock_release(rtld_bind_lock, &lockstate); 624 return target; 625 } 626 627 /* 628 * Error reporting function. Use it like printf. If formats the message 629 * into a buffer, and sets things up so that the next call to dlerror() 630 * will return the message. 631 */ 632 void 633 _rtld_error(const char *fmt, ...) 634 { 635 static char buf[512]; 636 va_list ap; 637 638 va_start(ap, fmt); 639 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 640 error_message = buf; 641 va_end(ap); 642 } 643 644 /* 645 * Return a dynamically-allocated copy of the current error message, if any. 646 */ 647 static char * 648 errmsg_save(void) 649 { 650 return error_message == NULL ? NULL : xstrdup(error_message); 651 } 652 653 /* 654 * Restore the current error message from a copy which was previously saved 655 * by errmsg_save(). The copy is freed. 656 */ 657 static void 658 errmsg_restore(char *saved_msg) 659 { 660 if (saved_msg == NULL) 661 error_message = NULL; 662 else { 663 _rtld_error("%s", saved_msg); 664 free(saved_msg); 665 } 666 } 667 668 static const char * 669 basename(const char *name) 670 { 671 const char *p = strrchr(name, '/'); 672 return p != NULL ? p + 1 : name; 673 } 674 675 static struct utsname uts; 676 677 static int 678 origin_subst_one(char **res, const char *real, const char *kw, const char *subst, 679 char *may_free) 680 { 681 const char *p, *p1; 682 char *res1; 683 int subst_len; 684 int kw_len; 685 686 res1 = *res = NULL; 687 p = real; 688 subst_len = kw_len = 0; 689 for (;;) { 690 p1 = strstr(p, kw); 691 if (p1 != NULL) { 692 if (subst_len == 0) { 693 subst_len = strlen(subst); 694 kw_len = strlen(kw); 695 } 696 if (*res == NULL) { 697 *res = xmalloc(PATH_MAX); 698 res1 = *res; 699 } 700 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) { 701 _rtld_error("Substitution of %s in %s cannot be performed", 702 kw, real); 703 if (may_free != NULL) 704 free(may_free); 705 free(res); 706 return (false); 707 } 708 memcpy(res1, p, p1 - p); 709 res1 += p1 - p; 710 memcpy(res1, subst, subst_len); 711 res1 += subst_len; 712 p = p1 + kw_len; 713 } else { 714 if (*res == NULL) { 715 if (may_free != NULL) 716 *res = may_free; 717 else 718 *res = xstrdup(real); 719 return (true); 720 } 721 *res1 = '\0'; 722 if (may_free != NULL) 723 free(may_free); 724 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) { 725 free(res); 726 return (false); 727 } 728 return (true); 729 } 730 } 731 } 732 733 static char * 734 origin_subst(const char *real, const char *origin_path) 735 { 736 char *res1, *res2, *res3, *res4; 737 738 if (uts.sysname[0] == '\0') { 739 if (uname(&uts) != 0) { 740 _rtld_error("utsname failed: %d", errno); 741 return (NULL); 742 } 743 } 744 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) || 745 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) || 746 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) || 747 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3)) 748 return (NULL); 749 return (res4); 750 } 751 752 static void 753 die(void) 754 { 755 const char *msg = dlerror(); 756 757 if (msg == NULL) 758 msg = "Fatal error"; 759 rtld_fdputstr(STDERR_FILENO, msg); 760 _exit(1); 761 } 762 763 /* 764 * Process a shared object's DYNAMIC section, and save the important 765 * information in its Obj_Entry structure. 766 */ 767 static void 768 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 769 const Elf_Dyn **dyn_soname) 770 { 771 const Elf_Dyn *dynp; 772 Needed_Entry **needed_tail = &obj->needed; 773 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 774 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 775 int plttype = DT_REL; 776 777 *dyn_rpath = NULL; 778 *dyn_soname = NULL; 779 780 obj->bind_now = false; 781 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 782 switch (dynp->d_tag) { 783 784 case DT_REL: 785 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 786 break; 787 788 case DT_RELSZ: 789 obj->relsize = dynp->d_un.d_val; 790 break; 791 792 case DT_RELENT: 793 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 794 break; 795 796 case DT_JMPREL: 797 obj->pltrel = (const Elf_Rel *) 798 (obj->relocbase + dynp->d_un.d_ptr); 799 break; 800 801 case DT_PLTRELSZ: 802 obj->pltrelsize = dynp->d_un.d_val; 803 break; 804 805 case DT_RELA: 806 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 807 break; 808 809 case DT_RELASZ: 810 obj->relasize = dynp->d_un.d_val; 811 break; 812 813 case DT_RELAENT: 814 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 815 break; 816 817 case DT_PLTREL: 818 plttype = dynp->d_un.d_val; 819 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 820 break; 821 822 case DT_SYMTAB: 823 obj->symtab = (const Elf_Sym *) 824 (obj->relocbase + dynp->d_un.d_ptr); 825 break; 826 827 case DT_SYMENT: 828 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 829 break; 830 831 case DT_STRTAB: 832 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 833 break; 834 835 case DT_STRSZ: 836 obj->strsize = dynp->d_un.d_val; 837 break; 838 839 case DT_VERNEED: 840 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 841 dynp->d_un.d_val); 842 break; 843 844 case DT_VERNEEDNUM: 845 obj->verneednum = dynp->d_un.d_val; 846 break; 847 848 case DT_VERDEF: 849 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 850 dynp->d_un.d_val); 851 break; 852 853 case DT_VERDEFNUM: 854 obj->verdefnum = dynp->d_un.d_val; 855 break; 856 857 case DT_VERSYM: 858 obj->versyms = (const Elf_Versym *)(obj->relocbase + 859 dynp->d_un.d_val); 860 break; 861 862 case DT_HASH: 863 { 864 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 865 (obj->relocbase + dynp->d_un.d_ptr); 866 obj->nbuckets = hashtab[0]; 867 obj->nchains = hashtab[1]; 868 obj->buckets = hashtab + 2; 869 obj->chains = obj->buckets + obj->nbuckets; 870 } 871 break; 872 873 case DT_NEEDED: 874 if (!obj->rtld) { 875 Needed_Entry *nep = NEW(Needed_Entry); 876 nep->name = dynp->d_un.d_val; 877 nep->obj = NULL; 878 nep->next = NULL; 879 880 *needed_tail = nep; 881 needed_tail = &nep->next; 882 } 883 break; 884 885 case DT_FILTER: 886 if (!obj->rtld) { 887 Needed_Entry *nep = NEW(Needed_Entry); 888 nep->name = dynp->d_un.d_val; 889 nep->obj = NULL; 890 nep->next = NULL; 891 892 *needed_filtees_tail = nep; 893 needed_filtees_tail = &nep->next; 894 } 895 break; 896 897 case DT_AUXILIARY: 898 if (!obj->rtld) { 899 Needed_Entry *nep = NEW(Needed_Entry); 900 nep->name = dynp->d_un.d_val; 901 nep->obj = NULL; 902 nep->next = NULL; 903 904 *needed_aux_filtees_tail = nep; 905 needed_aux_filtees_tail = &nep->next; 906 } 907 break; 908 909 case DT_PLTGOT: 910 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 911 break; 912 913 case DT_TEXTREL: 914 obj->textrel = true; 915 break; 916 917 case DT_SYMBOLIC: 918 obj->symbolic = true; 919 break; 920 921 case DT_RPATH: 922 case DT_RUNPATH: /* XXX: process separately */ 923 /* 924 * We have to wait until later to process this, because we 925 * might not have gotten the address of the string table yet. 926 */ 927 *dyn_rpath = dynp; 928 break; 929 930 case DT_SONAME: 931 *dyn_soname = dynp; 932 break; 933 934 case DT_INIT: 935 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 936 break; 937 938 case DT_FINI: 939 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 940 break; 941 942 /* 943 * Don't process DT_DEBUG on MIPS as the dynamic section 944 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 945 */ 946 947 #ifndef __mips__ 948 case DT_DEBUG: 949 /* XXX - not implemented yet */ 950 if (!early) 951 dbg("Filling in DT_DEBUG entry"); 952 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 953 break; 954 #endif 955 956 case DT_FLAGS: 957 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 958 obj->z_origin = true; 959 if (dynp->d_un.d_val & DF_SYMBOLIC) 960 obj->symbolic = true; 961 if (dynp->d_un.d_val & DF_TEXTREL) 962 obj->textrel = true; 963 if (dynp->d_un.d_val & DF_BIND_NOW) 964 obj->bind_now = true; 965 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 966 ;*/ 967 break; 968 #ifdef __mips__ 969 case DT_MIPS_LOCAL_GOTNO: 970 obj->local_gotno = dynp->d_un.d_val; 971 break; 972 973 case DT_MIPS_SYMTABNO: 974 obj->symtabno = dynp->d_un.d_val; 975 break; 976 977 case DT_MIPS_GOTSYM: 978 obj->gotsym = dynp->d_un.d_val; 979 break; 980 981 case DT_MIPS_RLD_MAP: 982 #ifdef notyet 983 if (!early) 984 dbg("Filling in DT_DEBUG entry"); 985 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 986 #endif 987 break; 988 #endif 989 990 case DT_FLAGS_1: 991 if (dynp->d_un.d_val & DF_1_NOOPEN) 992 obj->z_noopen = true; 993 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 994 obj->z_origin = true; 995 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 996 XXX ;*/ 997 if (dynp->d_un.d_val & DF_1_BIND_NOW) 998 obj->bind_now = true; 999 if (dynp->d_un.d_val & DF_1_NODELETE) 1000 obj->z_nodelete = true; 1001 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1002 obj->z_loadfltr = true; 1003 break; 1004 1005 default: 1006 if (!early) { 1007 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1008 (long)dynp->d_tag); 1009 } 1010 break; 1011 } 1012 } 1013 1014 obj->traced = false; 1015 1016 if (plttype == DT_RELA) { 1017 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1018 obj->pltrel = NULL; 1019 obj->pltrelasize = obj->pltrelsize; 1020 obj->pltrelsize = 0; 1021 } 1022 } 1023 1024 static void 1025 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1026 const Elf_Dyn *dyn_soname) 1027 { 1028 1029 if (obj->z_origin && obj->origin_path == NULL) { 1030 obj->origin_path = xmalloc(PATH_MAX); 1031 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1032 die(); 1033 } 1034 1035 if (dyn_rpath != NULL) { 1036 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1037 if (obj->z_origin) 1038 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1039 } 1040 1041 if (dyn_soname != NULL) 1042 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1043 } 1044 1045 static void 1046 digest_dynamic(Obj_Entry *obj, int early) 1047 { 1048 const Elf_Dyn *dyn_rpath; 1049 const Elf_Dyn *dyn_soname; 1050 1051 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname); 1052 digest_dynamic2(obj, dyn_rpath, dyn_soname); 1053 } 1054 1055 /* 1056 * Process a shared object's program header. This is used only for the 1057 * main program, when the kernel has already loaded the main program 1058 * into memory before calling the dynamic linker. It creates and 1059 * returns an Obj_Entry structure. 1060 */ 1061 static Obj_Entry * 1062 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1063 { 1064 Obj_Entry *obj; 1065 const Elf_Phdr *phlimit = phdr + phnum; 1066 const Elf_Phdr *ph; 1067 int nsegs = 0; 1068 1069 obj = obj_new(); 1070 for (ph = phdr; ph < phlimit; ph++) { 1071 if (ph->p_type != PT_PHDR) 1072 continue; 1073 1074 obj->phdr = phdr; 1075 obj->phsize = ph->p_memsz; 1076 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1077 break; 1078 } 1079 1080 obj->stack_flags = PF_X | PF_R | PF_W; 1081 1082 for (ph = phdr; ph < phlimit; ph++) { 1083 switch (ph->p_type) { 1084 1085 case PT_INTERP: 1086 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1087 break; 1088 1089 case PT_LOAD: 1090 if (nsegs == 0) { /* First load segment */ 1091 obj->vaddrbase = trunc_page(ph->p_vaddr); 1092 obj->mapbase = obj->vaddrbase + obj->relocbase; 1093 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1094 obj->vaddrbase; 1095 } else { /* Last load segment */ 1096 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1097 obj->vaddrbase; 1098 } 1099 nsegs++; 1100 break; 1101 1102 case PT_DYNAMIC: 1103 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1104 break; 1105 1106 case PT_TLS: 1107 obj->tlsindex = 1; 1108 obj->tlssize = ph->p_memsz; 1109 obj->tlsalign = ph->p_align; 1110 obj->tlsinitsize = ph->p_filesz; 1111 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1112 break; 1113 1114 case PT_GNU_STACK: 1115 obj->stack_flags = ph->p_flags; 1116 break; 1117 } 1118 } 1119 if (nsegs < 1) { 1120 _rtld_error("%s: too few PT_LOAD segments", path); 1121 return NULL; 1122 } 1123 1124 obj->entry = entry; 1125 return obj; 1126 } 1127 1128 static Obj_Entry * 1129 dlcheck(void *handle) 1130 { 1131 Obj_Entry *obj; 1132 1133 for (obj = obj_list; obj != NULL; obj = obj->next) 1134 if (obj == (Obj_Entry *) handle) 1135 break; 1136 1137 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1138 _rtld_error("Invalid shared object handle %p", handle); 1139 return NULL; 1140 } 1141 return obj; 1142 } 1143 1144 /* 1145 * If the given object is already in the donelist, return true. Otherwise 1146 * add the object to the list and return false. 1147 */ 1148 static bool 1149 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1150 { 1151 unsigned int i; 1152 1153 for (i = 0; i < dlp->num_used; i++) 1154 if (dlp->objs[i] == obj) 1155 return true; 1156 /* 1157 * Our donelist allocation should always be sufficient. But if 1158 * our threads locking isn't working properly, more shared objects 1159 * could have been loaded since we allocated the list. That should 1160 * never happen, but we'll handle it properly just in case it does. 1161 */ 1162 if (dlp->num_used < dlp->num_alloc) 1163 dlp->objs[dlp->num_used++] = obj; 1164 return false; 1165 } 1166 1167 /* 1168 * Hash function for symbol table lookup. Don't even think about changing 1169 * this. It is specified by the System V ABI. 1170 */ 1171 unsigned long 1172 elf_hash(const char *name) 1173 { 1174 const unsigned char *p = (const unsigned char *) name; 1175 unsigned long h = 0; 1176 unsigned long g; 1177 1178 while (*p != '\0') { 1179 h = (h << 4) + *p++; 1180 if ((g = h & 0xf0000000) != 0) 1181 h ^= g >> 24; 1182 h &= ~g; 1183 } 1184 return h; 1185 } 1186 1187 /* 1188 * Find the library with the given name, and return its full pathname. 1189 * The returned string is dynamically allocated. Generates an error 1190 * message and returns NULL if the library cannot be found. 1191 * 1192 * If the second argument is non-NULL, then it refers to an already- 1193 * loaded shared object, whose library search path will be searched. 1194 * 1195 * The search order is: 1196 * LD_LIBRARY_PATH 1197 * rpath in the referencing file 1198 * ldconfig hints 1199 * /lib:/usr/lib 1200 */ 1201 static char * 1202 find_library(const char *xname, const Obj_Entry *refobj) 1203 { 1204 char *pathname; 1205 char *name; 1206 1207 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1208 if (xname[0] != '/' && !trust) { 1209 _rtld_error("Absolute pathname required for shared object \"%s\"", 1210 xname); 1211 return NULL; 1212 } 1213 if (refobj != NULL && refobj->z_origin) 1214 return origin_subst(xname, refobj->origin_path); 1215 else 1216 return xstrdup(xname); 1217 } 1218 1219 if (libmap_disable || (refobj == NULL) || 1220 (name = lm_find(refobj->path, xname)) == NULL) 1221 name = (char *)xname; 1222 1223 dbg(" Searching for \"%s\"", name); 1224 1225 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1226 (refobj != NULL && 1227 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1228 (pathname = search_library_path(name, gethints())) != NULL || 1229 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1230 return pathname; 1231 1232 if(refobj != NULL && refobj->path != NULL) { 1233 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1234 name, basename(refobj->path)); 1235 } else { 1236 _rtld_error("Shared object \"%s\" not found", name); 1237 } 1238 return NULL; 1239 } 1240 1241 /* 1242 * Given a symbol number in a referencing object, find the corresponding 1243 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1244 * no definition was found. Returns a pointer to the Obj_Entry of the 1245 * defining object via the reference parameter DEFOBJ_OUT. 1246 */ 1247 const Elf_Sym * 1248 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1249 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1250 RtldLockState *lockstate) 1251 { 1252 const Elf_Sym *ref; 1253 const Elf_Sym *def; 1254 const Obj_Entry *defobj; 1255 SymLook req; 1256 const char *name; 1257 int res; 1258 1259 /* 1260 * If we have already found this symbol, get the information from 1261 * the cache. 1262 */ 1263 if (symnum >= refobj->nchains) 1264 return NULL; /* Bad object */ 1265 if (cache != NULL && cache[symnum].sym != NULL) { 1266 *defobj_out = cache[symnum].obj; 1267 return cache[symnum].sym; 1268 } 1269 1270 ref = refobj->symtab + symnum; 1271 name = refobj->strtab + ref->st_name; 1272 def = NULL; 1273 defobj = NULL; 1274 1275 /* 1276 * We don't have to do a full scale lookup if the symbol is local. 1277 * We know it will bind to the instance in this load module; to 1278 * which we already have a pointer (ie ref). By not doing a lookup, 1279 * we not only improve performance, but it also avoids unresolvable 1280 * symbols when local symbols are not in the hash table. This has 1281 * been seen with the ia64 toolchain. 1282 */ 1283 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1284 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1285 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1286 symnum); 1287 } 1288 symlook_init(&req, name); 1289 req.flags = flags; 1290 req.ventry = fetch_ventry(refobj, symnum); 1291 req.lockstate = lockstate; 1292 res = symlook_default(&req, refobj); 1293 if (res == 0) { 1294 def = req.sym_out; 1295 defobj = req.defobj_out; 1296 } 1297 } else { 1298 def = ref; 1299 defobj = refobj; 1300 } 1301 1302 /* 1303 * If we found no definition and the reference is weak, treat the 1304 * symbol as having the value zero. 1305 */ 1306 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1307 def = &sym_zero; 1308 defobj = obj_main; 1309 } 1310 1311 if (def != NULL) { 1312 *defobj_out = defobj; 1313 /* Record the information in the cache to avoid subsequent lookups. */ 1314 if (cache != NULL) { 1315 cache[symnum].sym = def; 1316 cache[symnum].obj = defobj; 1317 } 1318 } else { 1319 if (refobj != &obj_rtld) 1320 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1321 } 1322 return def; 1323 } 1324 1325 /* 1326 * Return the search path from the ldconfig hints file, reading it if 1327 * necessary. Returns NULL if there are problems with the hints file, 1328 * or if the search path there is empty. 1329 */ 1330 static const char * 1331 gethints(void) 1332 { 1333 static char *hints; 1334 1335 if (hints == NULL) { 1336 int fd; 1337 struct elfhints_hdr hdr; 1338 char *p; 1339 1340 /* Keep from trying again in case the hints file is bad. */ 1341 hints = ""; 1342 1343 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1) 1344 return NULL; 1345 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1346 hdr.magic != ELFHINTS_MAGIC || 1347 hdr.version != 1) { 1348 close(fd); 1349 return NULL; 1350 } 1351 p = xmalloc(hdr.dirlistlen + 1); 1352 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1353 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) { 1354 free(p); 1355 close(fd); 1356 return NULL; 1357 } 1358 hints = p; 1359 close(fd); 1360 } 1361 return hints[0] != '\0' ? hints : NULL; 1362 } 1363 1364 static void 1365 init_dag(Obj_Entry *root) 1366 { 1367 const Needed_Entry *needed; 1368 const Objlist_Entry *elm; 1369 DoneList donelist; 1370 1371 if (root->dag_inited) 1372 return; 1373 donelist_init(&donelist); 1374 1375 /* Root object belongs to own DAG. */ 1376 objlist_push_tail(&root->dldags, root); 1377 objlist_push_tail(&root->dagmembers, root); 1378 donelist_check(&donelist, root); 1379 1380 /* 1381 * Add dependencies of root object to DAG in breadth order 1382 * by exploiting the fact that each new object get added 1383 * to the tail of the dagmembers list. 1384 */ 1385 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1386 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1387 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1388 continue; 1389 objlist_push_tail(&needed->obj->dldags, root); 1390 objlist_push_tail(&root->dagmembers, needed->obj); 1391 } 1392 } 1393 root->dag_inited = true; 1394 } 1395 1396 /* 1397 * Initialize the dynamic linker. The argument is the address at which 1398 * the dynamic linker has been mapped into memory. The primary task of 1399 * this function is to relocate the dynamic linker. 1400 */ 1401 static void 1402 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1403 { 1404 Obj_Entry objtmp; /* Temporary rtld object */ 1405 const Elf_Dyn *dyn_rpath; 1406 const Elf_Dyn *dyn_soname; 1407 1408 /* 1409 * Conjure up an Obj_Entry structure for the dynamic linker. 1410 * 1411 * The "path" member can't be initialized yet because string constants 1412 * cannot yet be accessed. Below we will set it correctly. 1413 */ 1414 memset(&objtmp, 0, sizeof(objtmp)); 1415 objtmp.path = NULL; 1416 objtmp.rtld = true; 1417 objtmp.mapbase = mapbase; 1418 #ifdef PIC 1419 objtmp.relocbase = mapbase; 1420 #endif 1421 if (RTLD_IS_DYNAMIC()) { 1422 objtmp.dynamic = rtld_dynamic(&objtmp); 1423 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname); 1424 assert(objtmp.needed == NULL); 1425 #if !defined(__mips__) 1426 /* MIPS has a bogus DT_TEXTREL. */ 1427 assert(!objtmp.textrel); 1428 #endif 1429 1430 /* 1431 * Temporarily put the dynamic linker entry into the object list, so 1432 * that symbols can be found. 1433 */ 1434 1435 relocate_objects(&objtmp, true, &objtmp, NULL); 1436 } 1437 1438 /* Initialize the object list. */ 1439 obj_tail = &obj_list; 1440 1441 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1442 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1443 1444 if (aux_info[AT_PAGESZ] != NULL) 1445 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1446 if (aux_info[AT_OSRELDATE] != NULL) 1447 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1448 1449 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname); 1450 1451 /* Replace the path with a dynamically allocated copy. */ 1452 obj_rtld.path = xstrdup(PATH_RTLD); 1453 1454 r_debug.r_brk = r_debug_state; 1455 r_debug.r_state = RT_CONSISTENT; 1456 } 1457 1458 /* 1459 * Add the init functions from a needed object list (and its recursive 1460 * needed objects) to "list". This is not used directly; it is a helper 1461 * function for initlist_add_objects(). The write lock must be held 1462 * when this function is called. 1463 */ 1464 static void 1465 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1466 { 1467 /* Recursively process the successor needed objects. */ 1468 if (needed->next != NULL) 1469 initlist_add_neededs(needed->next, list); 1470 1471 /* Process the current needed object. */ 1472 if (needed->obj != NULL) 1473 initlist_add_objects(needed->obj, &needed->obj->next, list); 1474 } 1475 1476 /* 1477 * Scan all of the DAGs rooted in the range of objects from "obj" to 1478 * "tail" and add their init functions to "list". This recurses over 1479 * the DAGs and ensure the proper init ordering such that each object's 1480 * needed libraries are initialized before the object itself. At the 1481 * same time, this function adds the objects to the global finalization 1482 * list "list_fini" in the opposite order. The write lock must be 1483 * held when this function is called. 1484 */ 1485 static void 1486 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1487 { 1488 if (obj->init_scanned || obj->init_done) 1489 return; 1490 obj->init_scanned = true; 1491 1492 /* Recursively process the successor objects. */ 1493 if (&obj->next != tail) 1494 initlist_add_objects(obj->next, tail, list); 1495 1496 /* Recursively process the needed objects. */ 1497 if (obj->needed != NULL) 1498 initlist_add_neededs(obj->needed, list); 1499 1500 /* Add the object to the init list. */ 1501 if (obj->init != (Elf_Addr)NULL) 1502 objlist_push_tail(list, obj); 1503 1504 /* Add the object to the global fini list in the reverse order. */ 1505 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) { 1506 objlist_push_head(&list_fini, obj); 1507 obj->on_fini_list = true; 1508 } 1509 } 1510 1511 #ifndef FPTR_TARGET 1512 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1513 #endif 1514 1515 static void 1516 free_needed_filtees(Needed_Entry *n) 1517 { 1518 Needed_Entry *needed, *needed1; 1519 1520 for (needed = n; needed != NULL; needed = needed->next) { 1521 if (needed->obj != NULL) { 1522 dlclose(needed->obj); 1523 needed->obj = NULL; 1524 } 1525 } 1526 for (needed = n; needed != NULL; needed = needed1) { 1527 needed1 = needed->next; 1528 free(needed); 1529 } 1530 } 1531 1532 static void 1533 unload_filtees(Obj_Entry *obj) 1534 { 1535 1536 free_needed_filtees(obj->needed_filtees); 1537 obj->needed_filtees = NULL; 1538 free_needed_filtees(obj->needed_aux_filtees); 1539 obj->needed_aux_filtees = NULL; 1540 obj->filtees_loaded = false; 1541 } 1542 1543 static void 1544 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags) 1545 { 1546 1547 for (; needed != NULL; needed = needed->next) { 1548 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1549 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1550 RTLD_LOCAL); 1551 } 1552 } 1553 1554 static void 1555 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1556 { 1557 1558 lock_restart_for_upgrade(lockstate); 1559 if (!obj->filtees_loaded) { 1560 load_filtee1(obj, obj->needed_filtees, flags); 1561 load_filtee1(obj, obj->needed_aux_filtees, flags); 1562 obj->filtees_loaded = true; 1563 } 1564 } 1565 1566 static int 1567 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1568 { 1569 Obj_Entry *obj1; 1570 1571 for (; needed != NULL; needed = needed->next) { 1572 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1573 flags & ~RTLD_LO_NOLOAD); 1574 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1575 return (-1); 1576 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) { 1577 dbg("obj %s nodelete", obj1->path); 1578 init_dag(obj1); 1579 ref_dag(obj1); 1580 obj1->ref_nodel = true; 1581 } 1582 } 1583 return (0); 1584 } 1585 1586 /* 1587 * Given a shared object, traverse its list of needed objects, and load 1588 * each of them. Returns 0 on success. Generates an error message and 1589 * returns -1 on failure. 1590 */ 1591 static int 1592 load_needed_objects(Obj_Entry *first, int flags) 1593 { 1594 Obj_Entry *obj; 1595 1596 for (obj = first; obj != NULL; obj = obj->next) { 1597 if (process_needed(obj, obj->needed, flags) == -1) 1598 return (-1); 1599 } 1600 return (0); 1601 } 1602 1603 static int 1604 load_preload_objects(void) 1605 { 1606 char *p = ld_preload; 1607 static const char delim[] = " \t:;"; 1608 1609 if (p == NULL) 1610 return 0; 1611 1612 p += strspn(p, delim); 1613 while (*p != '\0') { 1614 size_t len = strcspn(p, delim); 1615 char savech; 1616 1617 savech = p[len]; 1618 p[len] = '\0'; 1619 if (load_object(p, -1, NULL, 0) == NULL) 1620 return -1; /* XXX - cleanup */ 1621 p[len] = savech; 1622 p += len; 1623 p += strspn(p, delim); 1624 } 1625 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 1626 return 0; 1627 } 1628 1629 static const char * 1630 printable_path(const char *path) 1631 { 1632 1633 return (path == NULL ? "<unknown>" : path); 1634 } 1635 1636 /* 1637 * Load a shared object into memory, if it is not already loaded. The 1638 * object may be specified by name or by user-supplied file descriptor 1639 * fd_u. In the later case, the fd_u descriptor is not closed, but its 1640 * duplicate is. 1641 * 1642 * Returns a pointer to the Obj_Entry for the object. Returns NULL 1643 * on failure. 1644 */ 1645 static Obj_Entry * 1646 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 1647 { 1648 Obj_Entry *obj; 1649 int fd; 1650 struct stat sb; 1651 char *path; 1652 1653 if (name != NULL) { 1654 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 1655 if (object_match_name(obj, name)) 1656 return (obj); 1657 } 1658 1659 path = find_library(name, refobj); 1660 if (path == NULL) 1661 return (NULL); 1662 } else 1663 path = NULL; 1664 1665 /* 1666 * If we didn't find a match by pathname, or the name is not 1667 * supplied, open the file and check again by device and inode. 1668 * This avoids false mismatches caused by multiple links or ".." 1669 * in pathnames. 1670 * 1671 * To avoid a race, we open the file and use fstat() rather than 1672 * using stat(). 1673 */ 1674 fd = -1; 1675 if (fd_u == -1) { 1676 if ((fd = open(path, O_RDONLY)) == -1) { 1677 _rtld_error("Cannot open \"%s\"", path); 1678 free(path); 1679 return (NULL); 1680 } 1681 } else { 1682 fd = dup(fd_u); 1683 if (fd == -1) { 1684 _rtld_error("Cannot dup fd"); 1685 free(path); 1686 return (NULL); 1687 } 1688 } 1689 if (fstat(fd, &sb) == -1) { 1690 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 1691 close(fd); 1692 free(path); 1693 return NULL; 1694 } 1695 for (obj = obj_list->next; obj != NULL; obj = obj->next) 1696 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 1697 break; 1698 if (obj != NULL && name != NULL) { 1699 object_add_name(obj, name); 1700 free(path); 1701 close(fd); 1702 return obj; 1703 } 1704 if (flags & RTLD_LO_NOLOAD) { 1705 free(path); 1706 close(fd); 1707 return (NULL); 1708 } 1709 1710 /* First use of this object, so we must map it in */ 1711 obj = do_load_object(fd, name, path, &sb, flags); 1712 if (obj == NULL) 1713 free(path); 1714 close(fd); 1715 1716 return obj; 1717 } 1718 1719 static Obj_Entry * 1720 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 1721 int flags) 1722 { 1723 Obj_Entry *obj; 1724 struct statfs fs; 1725 1726 /* 1727 * but first, make sure that environment variables haven't been 1728 * used to circumvent the noexec flag on a filesystem. 1729 */ 1730 if (dangerous_ld_env) { 1731 if (fstatfs(fd, &fs) != 0) { 1732 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 1733 return NULL; 1734 } 1735 if (fs.f_flags & MNT_NOEXEC) { 1736 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 1737 return NULL; 1738 } 1739 } 1740 dbg("loading \"%s\"", printable_path(path)); 1741 obj = map_object(fd, printable_path(path), sbp); 1742 if (obj == NULL) 1743 return NULL; 1744 1745 /* 1746 * If DT_SONAME is present in the object, digest_dynamic2 already 1747 * added it to the object names. 1748 */ 1749 if (name != NULL) 1750 object_add_name(obj, name); 1751 obj->path = path; 1752 digest_dynamic(obj, 0); 1753 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 1754 RTLD_LO_DLOPEN) { 1755 dbg("refusing to load non-loadable \"%s\"", obj->path); 1756 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 1757 munmap(obj->mapbase, obj->mapsize); 1758 obj_free(obj); 1759 return (NULL); 1760 } 1761 1762 *obj_tail = obj; 1763 obj_tail = &obj->next; 1764 obj_count++; 1765 obj_loads++; 1766 linkmap_add(obj); /* for GDB & dlinfo() */ 1767 max_stack_flags |= obj->stack_flags; 1768 1769 dbg(" %p .. %p: %s", obj->mapbase, 1770 obj->mapbase + obj->mapsize - 1, obj->path); 1771 if (obj->textrel) 1772 dbg(" WARNING: %s has impure text", obj->path); 1773 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 1774 obj->path); 1775 1776 return obj; 1777 } 1778 1779 static Obj_Entry * 1780 obj_from_addr(const void *addr) 1781 { 1782 Obj_Entry *obj; 1783 1784 for (obj = obj_list; obj != NULL; obj = obj->next) { 1785 if (addr < (void *) obj->mapbase) 1786 continue; 1787 if (addr < (void *) (obj->mapbase + obj->mapsize)) 1788 return obj; 1789 } 1790 return NULL; 1791 } 1792 1793 /* 1794 * Call the finalization functions for each of the objects in "list" 1795 * belonging to the DAG of "root" and referenced once. If NULL "root" 1796 * is specified, every finalization function will be called regardless 1797 * of the reference count and the list elements won't be freed. All of 1798 * the objects are expected to have non-NULL fini functions. 1799 */ 1800 static void 1801 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 1802 { 1803 Objlist_Entry *elm; 1804 char *saved_msg; 1805 1806 assert(root == NULL || root->refcount == 1); 1807 1808 /* 1809 * Preserve the current error message since a fini function might 1810 * call into the dynamic linker and overwrite it. 1811 */ 1812 saved_msg = errmsg_save(); 1813 do { 1814 STAILQ_FOREACH(elm, list, link) { 1815 if (root != NULL && (elm->obj->refcount != 1 || 1816 objlist_find(&root->dagmembers, elm->obj) == NULL)) 1817 continue; 1818 dbg("calling fini function for %s at %p", elm->obj->path, 1819 (void *)elm->obj->fini); 1820 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0, 1821 elm->obj->path); 1822 /* Remove object from fini list to prevent recursive invocation. */ 1823 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 1824 /* 1825 * XXX: If a dlopen() call references an object while the 1826 * fini function is in progress, we might end up trying to 1827 * unload the referenced object in dlclose() or the object 1828 * won't be unloaded although its fini function has been 1829 * called. 1830 */ 1831 lock_release(rtld_bind_lock, lockstate); 1832 call_initfini_pointer(elm->obj, elm->obj->fini); 1833 wlock_acquire(rtld_bind_lock, lockstate); 1834 /* No need to free anything if process is going down. */ 1835 if (root != NULL) 1836 free(elm); 1837 /* 1838 * We must restart the list traversal after every fini call 1839 * because a dlclose() call from the fini function or from 1840 * another thread might have modified the reference counts. 1841 */ 1842 break; 1843 } 1844 } while (elm != NULL); 1845 errmsg_restore(saved_msg); 1846 } 1847 1848 /* 1849 * Call the initialization functions for each of the objects in 1850 * "list". All of the objects are expected to have non-NULL init 1851 * functions. 1852 */ 1853 static void 1854 objlist_call_init(Objlist *list, RtldLockState *lockstate) 1855 { 1856 Objlist_Entry *elm; 1857 Obj_Entry *obj; 1858 char *saved_msg; 1859 1860 /* 1861 * Clean init_scanned flag so that objects can be rechecked and 1862 * possibly initialized earlier if any of vectors called below 1863 * cause the change by using dlopen. 1864 */ 1865 for (obj = obj_list; obj != NULL; obj = obj->next) 1866 obj->init_scanned = false; 1867 1868 /* 1869 * Preserve the current error message since an init function might 1870 * call into the dynamic linker and overwrite it. 1871 */ 1872 saved_msg = errmsg_save(); 1873 STAILQ_FOREACH(elm, list, link) { 1874 if (elm->obj->init_done) /* Initialized early. */ 1875 continue; 1876 dbg("calling init function for %s at %p", elm->obj->path, 1877 (void *)elm->obj->init); 1878 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0, 1879 elm->obj->path); 1880 /* 1881 * Race: other thread might try to use this object before current 1882 * one completes the initilization. Not much can be done here 1883 * without better locking. 1884 */ 1885 elm->obj->init_done = true; 1886 lock_release(rtld_bind_lock, lockstate); 1887 call_initfini_pointer(elm->obj, elm->obj->init); 1888 wlock_acquire(rtld_bind_lock, lockstate); 1889 } 1890 errmsg_restore(saved_msg); 1891 } 1892 1893 static void 1894 objlist_clear(Objlist *list) 1895 { 1896 Objlist_Entry *elm; 1897 1898 while (!STAILQ_EMPTY(list)) { 1899 elm = STAILQ_FIRST(list); 1900 STAILQ_REMOVE_HEAD(list, link); 1901 free(elm); 1902 } 1903 } 1904 1905 static Objlist_Entry * 1906 objlist_find(Objlist *list, const Obj_Entry *obj) 1907 { 1908 Objlist_Entry *elm; 1909 1910 STAILQ_FOREACH(elm, list, link) 1911 if (elm->obj == obj) 1912 return elm; 1913 return NULL; 1914 } 1915 1916 static void 1917 objlist_init(Objlist *list) 1918 { 1919 STAILQ_INIT(list); 1920 } 1921 1922 static void 1923 objlist_push_head(Objlist *list, Obj_Entry *obj) 1924 { 1925 Objlist_Entry *elm; 1926 1927 elm = NEW(Objlist_Entry); 1928 elm->obj = obj; 1929 STAILQ_INSERT_HEAD(list, elm, link); 1930 } 1931 1932 static void 1933 objlist_push_tail(Objlist *list, Obj_Entry *obj) 1934 { 1935 Objlist_Entry *elm; 1936 1937 elm = NEW(Objlist_Entry); 1938 elm->obj = obj; 1939 STAILQ_INSERT_TAIL(list, elm, link); 1940 } 1941 1942 static void 1943 objlist_remove(Objlist *list, Obj_Entry *obj) 1944 { 1945 Objlist_Entry *elm; 1946 1947 if ((elm = objlist_find(list, obj)) != NULL) { 1948 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 1949 free(elm); 1950 } 1951 } 1952 1953 /* 1954 * Relocate newly-loaded shared objects. The argument is a pointer to 1955 * the Obj_Entry for the first such object. All objects from the first 1956 * to the end of the list of objects are relocated. Returns 0 on success, 1957 * or -1 on failure. 1958 */ 1959 static int 1960 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 1961 RtldLockState *lockstate) 1962 { 1963 Obj_Entry *obj; 1964 1965 for (obj = first; obj != NULL; obj = obj->next) { 1966 if (obj != rtldobj) 1967 dbg("relocating \"%s\"", obj->path); 1968 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL || 1969 obj->symtab == NULL || obj->strtab == NULL) { 1970 _rtld_error("%s: Shared object has no run-time symbol table", 1971 obj->path); 1972 return -1; 1973 } 1974 1975 if (obj->textrel) { 1976 /* There are relocations to the write-protected text segment. */ 1977 if (mprotect(obj->mapbase, obj->textsize, 1978 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 1979 _rtld_error("%s: Cannot write-enable text segment: %s", 1980 obj->path, strerror(errno)); 1981 return -1; 1982 } 1983 } 1984 1985 /* Process the non-PLT relocations. */ 1986 if (reloc_non_plt(obj, rtldobj, lockstate)) 1987 return -1; 1988 1989 if (obj->textrel) { /* Re-protected the text segment. */ 1990 if (mprotect(obj->mapbase, obj->textsize, 1991 PROT_READ|PROT_EXEC) == -1) { 1992 _rtld_error("%s: Cannot write-protect text segment: %s", 1993 obj->path, strerror(errno)); 1994 return -1; 1995 } 1996 } 1997 1998 1999 /* Set the special PLT or GOT entries. */ 2000 init_pltgot(obj); 2001 2002 /* Process the PLT relocations. */ 2003 if (reloc_plt(obj) == -1) 2004 return -1; 2005 /* Relocate the jump slots if we are doing immediate binding. */ 2006 if (obj->bind_now || bind_now) 2007 if (reloc_jmpslots(obj, lockstate) == -1) 2008 return -1; 2009 2010 /* 2011 * Set up the magic number and version in the Obj_Entry. These 2012 * were checked in the crt1.o from the original ElfKit, so we 2013 * set them for backward compatibility. 2014 */ 2015 obj->magic = RTLD_MAGIC; 2016 obj->version = RTLD_VERSION; 2017 } 2018 2019 return (0); 2020 } 2021 2022 /* 2023 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2024 * referencing STT_GNU_IFUNC symbols is postponed till the other 2025 * relocations are done. The indirect functions specified as 2026 * ifunc are allowed to call other symbols, so we need to have 2027 * objects relocated before asking for resolution from indirects. 2028 * 2029 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2030 * instead of the usual lazy handling of PLT slots. It is 2031 * consistent with how GNU does it. 2032 */ 2033 static int 2034 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, RtldLockState *lockstate) 2035 { 2036 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2037 return (-1); 2038 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2039 reloc_gnu_ifunc(obj, lockstate) == -1) 2040 return (-1); 2041 return (0); 2042 } 2043 2044 static int 2045 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, RtldLockState *lockstate) 2046 { 2047 Obj_Entry *obj; 2048 2049 for (obj = first; obj != NULL; obj = obj->next) { 2050 if (resolve_object_ifunc(obj, bind_now, lockstate) == -1) 2051 return (-1); 2052 } 2053 return (0); 2054 } 2055 2056 static int 2057 initlist_objects_ifunc(Objlist *list, bool bind_now, RtldLockState *lockstate) 2058 { 2059 Objlist_Entry *elm; 2060 2061 STAILQ_FOREACH(elm, list, link) { 2062 if (resolve_object_ifunc(elm->obj, bind_now, lockstate) == -1) 2063 return (-1); 2064 } 2065 return (0); 2066 } 2067 2068 /* 2069 * Cleanup procedure. It will be called (by the atexit mechanism) just 2070 * before the process exits. 2071 */ 2072 static void 2073 rtld_exit(void) 2074 { 2075 RtldLockState lockstate; 2076 2077 wlock_acquire(rtld_bind_lock, &lockstate); 2078 dbg("rtld_exit()"); 2079 objlist_call_fini(&list_fini, NULL, &lockstate); 2080 /* No need to remove the items from the list, since we are exiting. */ 2081 if (!libmap_disable) 2082 lm_fini(); 2083 lock_release(rtld_bind_lock, &lockstate); 2084 } 2085 2086 static void * 2087 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2088 { 2089 #ifdef COMPAT_32BIT 2090 const char *trans; 2091 #endif 2092 if (path == NULL) 2093 return (NULL); 2094 2095 path += strspn(path, ":;"); 2096 while (*path != '\0') { 2097 size_t len; 2098 char *res; 2099 2100 len = strcspn(path, ":;"); 2101 #ifdef COMPAT_32BIT 2102 trans = lm_findn(NULL, path, len); 2103 if (trans) 2104 res = callback(trans, strlen(trans), arg); 2105 else 2106 #endif 2107 res = callback(path, len, arg); 2108 2109 if (res != NULL) 2110 return (res); 2111 2112 path += len; 2113 path += strspn(path, ":;"); 2114 } 2115 2116 return (NULL); 2117 } 2118 2119 struct try_library_args { 2120 const char *name; 2121 size_t namelen; 2122 char *buffer; 2123 size_t buflen; 2124 }; 2125 2126 static void * 2127 try_library_path(const char *dir, size_t dirlen, void *param) 2128 { 2129 struct try_library_args *arg; 2130 2131 arg = param; 2132 if (*dir == '/' || trust) { 2133 char *pathname; 2134 2135 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2136 return (NULL); 2137 2138 pathname = arg->buffer; 2139 strncpy(pathname, dir, dirlen); 2140 pathname[dirlen] = '/'; 2141 strcpy(pathname + dirlen + 1, arg->name); 2142 2143 dbg(" Trying \"%s\"", pathname); 2144 if (access(pathname, F_OK) == 0) { /* We found it */ 2145 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2146 strcpy(pathname, arg->buffer); 2147 return (pathname); 2148 } 2149 } 2150 return (NULL); 2151 } 2152 2153 static char * 2154 search_library_path(const char *name, const char *path) 2155 { 2156 char *p; 2157 struct try_library_args arg; 2158 2159 if (path == NULL) 2160 return NULL; 2161 2162 arg.name = name; 2163 arg.namelen = strlen(name); 2164 arg.buffer = xmalloc(PATH_MAX); 2165 arg.buflen = PATH_MAX; 2166 2167 p = path_enumerate(path, try_library_path, &arg); 2168 2169 free(arg.buffer); 2170 2171 return (p); 2172 } 2173 2174 int 2175 dlclose(void *handle) 2176 { 2177 Obj_Entry *root; 2178 RtldLockState lockstate; 2179 2180 wlock_acquire(rtld_bind_lock, &lockstate); 2181 root = dlcheck(handle); 2182 if (root == NULL) { 2183 lock_release(rtld_bind_lock, &lockstate); 2184 return -1; 2185 } 2186 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2187 root->path); 2188 2189 /* Unreference the object and its dependencies. */ 2190 root->dl_refcount--; 2191 2192 if (root->refcount == 1) { 2193 /* 2194 * The object will be no longer referenced, so we must unload it. 2195 * First, call the fini functions. 2196 */ 2197 objlist_call_fini(&list_fini, root, &lockstate); 2198 2199 unref_dag(root); 2200 2201 /* Finish cleaning up the newly-unreferenced objects. */ 2202 GDB_STATE(RT_DELETE,&root->linkmap); 2203 unload_object(root); 2204 GDB_STATE(RT_CONSISTENT,NULL); 2205 } else 2206 unref_dag(root); 2207 2208 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2209 lock_release(rtld_bind_lock, &lockstate); 2210 return 0; 2211 } 2212 2213 char * 2214 dlerror(void) 2215 { 2216 char *msg = error_message; 2217 error_message = NULL; 2218 return msg; 2219 } 2220 2221 /* 2222 * This function is deprecated and has no effect. 2223 */ 2224 void 2225 dllockinit(void *context, 2226 void *(*lock_create)(void *context), 2227 void (*rlock_acquire)(void *lock), 2228 void (*wlock_acquire)(void *lock), 2229 void (*lock_release)(void *lock), 2230 void (*lock_destroy)(void *lock), 2231 void (*context_destroy)(void *context)) 2232 { 2233 static void *cur_context; 2234 static void (*cur_context_destroy)(void *); 2235 2236 /* Just destroy the context from the previous call, if necessary. */ 2237 if (cur_context_destroy != NULL) 2238 cur_context_destroy(cur_context); 2239 cur_context = context; 2240 cur_context_destroy = context_destroy; 2241 } 2242 2243 void * 2244 dlopen(const char *name, int mode) 2245 { 2246 2247 return (rtld_dlopen(name, -1, mode)); 2248 } 2249 2250 void * 2251 fdlopen(int fd, int mode) 2252 { 2253 2254 return (rtld_dlopen(NULL, fd, mode)); 2255 } 2256 2257 static void * 2258 rtld_dlopen(const char *name, int fd, int mode) 2259 { 2260 RtldLockState lockstate; 2261 int lo_flags; 2262 2263 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2264 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2265 if (ld_tracing != NULL) { 2266 rlock_acquire(rtld_bind_lock, &lockstate); 2267 if (sigsetjmp(lockstate.env, 0) != 0) 2268 lock_upgrade(rtld_bind_lock, &lockstate); 2269 environ = (char **)*get_program_var_addr("environ", &lockstate); 2270 lock_release(rtld_bind_lock, &lockstate); 2271 } 2272 lo_flags = RTLD_LO_DLOPEN; 2273 if (mode & RTLD_NODELETE) 2274 lo_flags |= RTLD_LO_NODELETE; 2275 if (mode & RTLD_NOLOAD) 2276 lo_flags |= RTLD_LO_NOLOAD; 2277 if (ld_tracing != NULL) 2278 lo_flags |= RTLD_LO_TRACE; 2279 2280 return (dlopen_object(name, fd, obj_main, lo_flags, 2281 mode & (RTLD_MODEMASK | RTLD_GLOBAL))); 2282 } 2283 2284 static void 2285 dlopen_cleanup(Obj_Entry *obj) 2286 { 2287 2288 obj->dl_refcount--; 2289 unref_dag(obj); 2290 if (obj->refcount == 0) 2291 unload_object(obj); 2292 } 2293 2294 static Obj_Entry * 2295 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2296 int mode) 2297 { 2298 Obj_Entry **old_obj_tail; 2299 Obj_Entry *obj; 2300 Objlist initlist; 2301 RtldLockState lockstate; 2302 int result; 2303 2304 objlist_init(&initlist); 2305 2306 wlock_acquire(rtld_bind_lock, &lockstate); 2307 GDB_STATE(RT_ADD,NULL); 2308 2309 old_obj_tail = obj_tail; 2310 obj = NULL; 2311 if (name == NULL && fd == -1) { 2312 obj = obj_main; 2313 obj->refcount++; 2314 } else { 2315 obj = load_object(name, fd, refobj, lo_flags); 2316 } 2317 2318 if (obj) { 2319 obj->dl_refcount++; 2320 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2321 objlist_push_tail(&list_global, obj); 2322 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2323 assert(*old_obj_tail == obj); 2324 result = load_needed_objects(obj, lo_flags & RTLD_LO_DLOPEN); 2325 init_dag(obj); 2326 ref_dag(obj); 2327 if (result != -1) 2328 result = rtld_verify_versions(&obj->dagmembers); 2329 if (result != -1 && ld_tracing) 2330 goto trace; 2331 if (result == -1 || (relocate_objects(obj, (mode & RTLD_MODEMASK) 2332 == RTLD_NOW, &obj_rtld, &lockstate)) == -1) { 2333 dlopen_cleanup(obj); 2334 obj = NULL; 2335 } else { 2336 /* Make list of init functions to call. */ 2337 initlist_add_objects(obj, &obj->next, &initlist); 2338 } 2339 } else { 2340 2341 /* 2342 * Bump the reference counts for objects on this DAG. If 2343 * this is the first dlopen() call for the object that was 2344 * already loaded as a dependency, initialize the dag 2345 * starting at it. 2346 */ 2347 init_dag(obj); 2348 ref_dag(obj); 2349 2350 if ((lo_flags & RTLD_LO_TRACE) != 0) 2351 goto trace; 2352 } 2353 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2354 obj->z_nodelete) && !obj->ref_nodel) { 2355 dbg("obj %s nodelete", obj->path); 2356 ref_dag(obj); 2357 obj->z_nodelete = obj->ref_nodel = true; 2358 } 2359 } 2360 2361 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2362 name); 2363 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2364 2365 map_stacks_exec(&lockstate); 2366 2367 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2368 &lockstate) == -1) { 2369 objlist_clear(&initlist); 2370 dlopen_cleanup(obj); 2371 lock_release(rtld_bind_lock, &lockstate); 2372 return (NULL); 2373 } 2374 2375 /* Call the init functions. */ 2376 objlist_call_init(&initlist, &lockstate); 2377 objlist_clear(&initlist); 2378 lock_release(rtld_bind_lock, &lockstate); 2379 return obj; 2380 trace: 2381 trace_loaded_objects(obj); 2382 lock_release(rtld_bind_lock, &lockstate); 2383 exit(0); 2384 } 2385 2386 static void * 2387 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2388 int flags) 2389 { 2390 DoneList donelist; 2391 const Obj_Entry *obj, *defobj; 2392 const Elf_Sym *def; 2393 SymLook req; 2394 RtldLockState lockstate; 2395 int res; 2396 2397 def = NULL; 2398 defobj = NULL; 2399 symlook_init(&req, name); 2400 req.ventry = ve; 2401 req.flags = flags | SYMLOOK_IN_PLT; 2402 req.lockstate = &lockstate; 2403 2404 rlock_acquire(rtld_bind_lock, &lockstate); 2405 if (sigsetjmp(lockstate.env, 0) != 0) 2406 lock_upgrade(rtld_bind_lock, &lockstate); 2407 if (handle == NULL || handle == RTLD_NEXT || 2408 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2409 2410 if ((obj = obj_from_addr(retaddr)) == NULL) { 2411 _rtld_error("Cannot determine caller's shared object"); 2412 lock_release(rtld_bind_lock, &lockstate); 2413 return NULL; 2414 } 2415 if (handle == NULL) { /* Just the caller's shared object. */ 2416 res = symlook_obj(&req, obj); 2417 if (res == 0) { 2418 def = req.sym_out; 2419 defobj = req.defobj_out; 2420 } 2421 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2422 handle == RTLD_SELF) { /* ... caller included */ 2423 if (handle == RTLD_NEXT) 2424 obj = obj->next; 2425 for (; obj != NULL; obj = obj->next) { 2426 res = symlook_obj(&req, obj); 2427 if (res == 0) { 2428 if (def == NULL || 2429 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2430 def = req.sym_out; 2431 defobj = req.defobj_out; 2432 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2433 break; 2434 } 2435 } 2436 } 2437 /* 2438 * Search the dynamic linker itself, and possibly resolve the 2439 * symbol from there. This is how the application links to 2440 * dynamic linker services such as dlopen. 2441 */ 2442 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2443 res = symlook_obj(&req, &obj_rtld); 2444 if (res == 0) { 2445 def = req.sym_out; 2446 defobj = req.defobj_out; 2447 } 2448 } 2449 } else { 2450 assert(handle == RTLD_DEFAULT); 2451 res = symlook_default(&req, obj); 2452 if (res == 0) { 2453 defobj = req.defobj_out; 2454 def = req.sym_out; 2455 } 2456 } 2457 } else { 2458 if ((obj = dlcheck(handle)) == NULL) { 2459 lock_release(rtld_bind_lock, &lockstate); 2460 return NULL; 2461 } 2462 2463 donelist_init(&donelist); 2464 if (obj->mainprog) { 2465 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 2466 res = symlook_global(&req, &donelist); 2467 if (res == 0) { 2468 def = req.sym_out; 2469 defobj = req.defobj_out; 2470 } 2471 /* 2472 * Search the dynamic linker itself, and possibly resolve the 2473 * symbol from there. This is how the application links to 2474 * dynamic linker services such as dlopen. 2475 */ 2476 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2477 res = symlook_obj(&req, &obj_rtld); 2478 if (res == 0) { 2479 def = req.sym_out; 2480 defobj = req.defobj_out; 2481 } 2482 } 2483 } 2484 else { 2485 /* Search the whole DAG rooted at the given object. */ 2486 res = symlook_list(&req, &obj->dagmembers, &donelist); 2487 if (res == 0) { 2488 def = req.sym_out; 2489 defobj = req.defobj_out; 2490 } 2491 } 2492 } 2493 2494 if (def != NULL) { 2495 lock_release(rtld_bind_lock, &lockstate); 2496 2497 /* 2498 * The value required by the caller is derived from the value 2499 * of the symbol. For the ia64 architecture, we need to 2500 * construct a function descriptor which the caller can use to 2501 * call the function with the right 'gp' value. For other 2502 * architectures and for non-functions, the value is simply 2503 * the relocated value of the symbol. 2504 */ 2505 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 2506 return (make_function_pointer(def, defobj)); 2507 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 2508 return (rtld_resolve_ifunc(defobj, def)); 2509 else 2510 return (defobj->relocbase + def->st_value); 2511 } 2512 2513 _rtld_error("Undefined symbol \"%s\"", name); 2514 lock_release(rtld_bind_lock, &lockstate); 2515 return NULL; 2516 } 2517 2518 void * 2519 dlsym(void *handle, const char *name) 2520 { 2521 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 2522 SYMLOOK_DLSYM); 2523 } 2524 2525 dlfunc_t 2526 dlfunc(void *handle, const char *name) 2527 { 2528 union { 2529 void *d; 2530 dlfunc_t f; 2531 } rv; 2532 2533 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 2534 SYMLOOK_DLSYM); 2535 return (rv.f); 2536 } 2537 2538 void * 2539 dlvsym(void *handle, const char *name, const char *version) 2540 { 2541 Ver_Entry ventry; 2542 2543 ventry.name = version; 2544 ventry.file = NULL; 2545 ventry.hash = elf_hash(version); 2546 ventry.flags= 0; 2547 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 2548 SYMLOOK_DLSYM); 2549 } 2550 2551 int 2552 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 2553 { 2554 const Obj_Entry *obj; 2555 RtldLockState lockstate; 2556 2557 rlock_acquire(rtld_bind_lock, &lockstate); 2558 obj = obj_from_addr(addr); 2559 if (obj == NULL) { 2560 _rtld_error("No shared object contains address"); 2561 lock_release(rtld_bind_lock, &lockstate); 2562 return (0); 2563 } 2564 rtld_fill_dl_phdr_info(obj, phdr_info); 2565 lock_release(rtld_bind_lock, &lockstate); 2566 return (1); 2567 } 2568 2569 int 2570 dladdr(const void *addr, Dl_info *info) 2571 { 2572 const Obj_Entry *obj; 2573 const Elf_Sym *def; 2574 void *symbol_addr; 2575 unsigned long symoffset; 2576 RtldLockState lockstate; 2577 2578 rlock_acquire(rtld_bind_lock, &lockstate); 2579 obj = obj_from_addr(addr); 2580 if (obj == NULL) { 2581 _rtld_error("No shared object contains address"); 2582 lock_release(rtld_bind_lock, &lockstate); 2583 return 0; 2584 } 2585 info->dli_fname = obj->path; 2586 info->dli_fbase = obj->mapbase; 2587 info->dli_saddr = (void *)0; 2588 info->dli_sname = NULL; 2589 2590 /* 2591 * Walk the symbol list looking for the symbol whose address is 2592 * closest to the address sent in. 2593 */ 2594 for (symoffset = 0; symoffset < obj->nchains; symoffset++) { 2595 def = obj->symtab + symoffset; 2596 2597 /* 2598 * For skip the symbol if st_shndx is either SHN_UNDEF or 2599 * SHN_COMMON. 2600 */ 2601 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 2602 continue; 2603 2604 /* 2605 * If the symbol is greater than the specified address, or if it 2606 * is further away from addr than the current nearest symbol, 2607 * then reject it. 2608 */ 2609 symbol_addr = obj->relocbase + def->st_value; 2610 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 2611 continue; 2612 2613 /* Update our idea of the nearest symbol. */ 2614 info->dli_sname = obj->strtab + def->st_name; 2615 info->dli_saddr = symbol_addr; 2616 2617 /* Exact match? */ 2618 if (info->dli_saddr == addr) 2619 break; 2620 } 2621 lock_release(rtld_bind_lock, &lockstate); 2622 return 1; 2623 } 2624 2625 int 2626 dlinfo(void *handle, int request, void *p) 2627 { 2628 const Obj_Entry *obj; 2629 RtldLockState lockstate; 2630 int error; 2631 2632 rlock_acquire(rtld_bind_lock, &lockstate); 2633 2634 if (handle == NULL || handle == RTLD_SELF) { 2635 void *retaddr; 2636 2637 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 2638 if ((obj = obj_from_addr(retaddr)) == NULL) 2639 _rtld_error("Cannot determine caller's shared object"); 2640 } else 2641 obj = dlcheck(handle); 2642 2643 if (obj == NULL) { 2644 lock_release(rtld_bind_lock, &lockstate); 2645 return (-1); 2646 } 2647 2648 error = 0; 2649 switch (request) { 2650 case RTLD_DI_LINKMAP: 2651 *((struct link_map const **)p) = &obj->linkmap; 2652 break; 2653 case RTLD_DI_ORIGIN: 2654 error = rtld_dirname(obj->path, p); 2655 break; 2656 2657 case RTLD_DI_SERINFOSIZE: 2658 case RTLD_DI_SERINFO: 2659 error = do_search_info(obj, request, (struct dl_serinfo *)p); 2660 break; 2661 2662 default: 2663 _rtld_error("Invalid request %d passed to dlinfo()", request); 2664 error = -1; 2665 } 2666 2667 lock_release(rtld_bind_lock, &lockstate); 2668 2669 return (error); 2670 } 2671 2672 static void 2673 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 2674 { 2675 2676 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 2677 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 2678 STAILQ_FIRST(&obj->names)->name : obj->path; 2679 phdr_info->dlpi_phdr = obj->phdr; 2680 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 2681 phdr_info->dlpi_tls_modid = obj->tlsindex; 2682 phdr_info->dlpi_tls_data = obj->tlsinit; 2683 phdr_info->dlpi_adds = obj_loads; 2684 phdr_info->dlpi_subs = obj_loads - obj_count; 2685 } 2686 2687 int 2688 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 2689 { 2690 struct dl_phdr_info phdr_info; 2691 const Obj_Entry *obj; 2692 RtldLockState bind_lockstate, phdr_lockstate; 2693 int error; 2694 2695 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 2696 rlock_acquire(rtld_bind_lock, &bind_lockstate); 2697 2698 error = 0; 2699 2700 for (obj = obj_list; obj != NULL; obj = obj->next) { 2701 rtld_fill_dl_phdr_info(obj, &phdr_info); 2702 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 2703 break; 2704 2705 } 2706 lock_release(rtld_bind_lock, &bind_lockstate); 2707 lock_release(rtld_phdr_lock, &phdr_lockstate); 2708 2709 return (error); 2710 } 2711 2712 struct fill_search_info_args { 2713 int request; 2714 unsigned int flags; 2715 Dl_serinfo *serinfo; 2716 Dl_serpath *serpath; 2717 char *strspace; 2718 }; 2719 2720 static void * 2721 fill_search_info(const char *dir, size_t dirlen, void *param) 2722 { 2723 struct fill_search_info_args *arg; 2724 2725 arg = param; 2726 2727 if (arg->request == RTLD_DI_SERINFOSIZE) { 2728 arg->serinfo->dls_cnt ++; 2729 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1; 2730 } else { 2731 struct dl_serpath *s_entry; 2732 2733 s_entry = arg->serpath; 2734 s_entry->dls_name = arg->strspace; 2735 s_entry->dls_flags = arg->flags; 2736 2737 strncpy(arg->strspace, dir, dirlen); 2738 arg->strspace[dirlen] = '\0'; 2739 2740 arg->strspace += dirlen + 1; 2741 arg->serpath++; 2742 } 2743 2744 return (NULL); 2745 } 2746 2747 static int 2748 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 2749 { 2750 struct dl_serinfo _info; 2751 struct fill_search_info_args args; 2752 2753 args.request = RTLD_DI_SERINFOSIZE; 2754 args.serinfo = &_info; 2755 2756 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2757 _info.dls_cnt = 0; 2758 2759 path_enumerate(ld_library_path, fill_search_info, &args); 2760 path_enumerate(obj->rpath, fill_search_info, &args); 2761 path_enumerate(gethints(), fill_search_info, &args); 2762 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 2763 2764 2765 if (request == RTLD_DI_SERINFOSIZE) { 2766 info->dls_size = _info.dls_size; 2767 info->dls_cnt = _info.dls_cnt; 2768 return (0); 2769 } 2770 2771 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 2772 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 2773 return (-1); 2774 } 2775 2776 args.request = RTLD_DI_SERINFO; 2777 args.serinfo = info; 2778 args.serpath = &info->dls_serpath[0]; 2779 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 2780 2781 args.flags = LA_SER_LIBPATH; 2782 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 2783 return (-1); 2784 2785 args.flags = LA_SER_RUNPATH; 2786 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 2787 return (-1); 2788 2789 args.flags = LA_SER_CONFIG; 2790 if (path_enumerate(gethints(), fill_search_info, &args) != NULL) 2791 return (-1); 2792 2793 args.flags = LA_SER_DEFAULT; 2794 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 2795 return (-1); 2796 return (0); 2797 } 2798 2799 static int 2800 rtld_dirname(const char *path, char *bname) 2801 { 2802 const char *endp; 2803 2804 /* Empty or NULL string gets treated as "." */ 2805 if (path == NULL || *path == '\0') { 2806 bname[0] = '.'; 2807 bname[1] = '\0'; 2808 return (0); 2809 } 2810 2811 /* Strip trailing slashes */ 2812 endp = path + strlen(path) - 1; 2813 while (endp > path && *endp == '/') 2814 endp--; 2815 2816 /* Find the start of the dir */ 2817 while (endp > path && *endp != '/') 2818 endp--; 2819 2820 /* Either the dir is "/" or there are no slashes */ 2821 if (endp == path) { 2822 bname[0] = *endp == '/' ? '/' : '.'; 2823 bname[1] = '\0'; 2824 return (0); 2825 } else { 2826 do { 2827 endp--; 2828 } while (endp > path && *endp == '/'); 2829 } 2830 2831 if (endp - path + 2 > PATH_MAX) 2832 { 2833 _rtld_error("Filename is too long: %s", path); 2834 return(-1); 2835 } 2836 2837 strncpy(bname, path, endp - path + 1); 2838 bname[endp - path + 1] = '\0'; 2839 return (0); 2840 } 2841 2842 static int 2843 rtld_dirname_abs(const char *path, char *base) 2844 { 2845 char base_rel[PATH_MAX]; 2846 2847 if (rtld_dirname(path, base) == -1) 2848 return (-1); 2849 if (base[0] == '/') 2850 return (0); 2851 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 2852 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 2853 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 2854 return (-1); 2855 strcpy(base, base_rel); 2856 return (0); 2857 } 2858 2859 static void 2860 linkmap_add(Obj_Entry *obj) 2861 { 2862 struct link_map *l = &obj->linkmap; 2863 struct link_map *prev; 2864 2865 obj->linkmap.l_name = obj->path; 2866 obj->linkmap.l_addr = obj->mapbase; 2867 obj->linkmap.l_ld = obj->dynamic; 2868 #ifdef __mips__ 2869 /* GDB needs load offset on MIPS to use the symbols */ 2870 obj->linkmap.l_offs = obj->relocbase; 2871 #endif 2872 2873 if (r_debug.r_map == NULL) { 2874 r_debug.r_map = l; 2875 return; 2876 } 2877 2878 /* 2879 * Scan to the end of the list, but not past the entry for the 2880 * dynamic linker, which we want to keep at the very end. 2881 */ 2882 for (prev = r_debug.r_map; 2883 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 2884 prev = prev->l_next) 2885 ; 2886 2887 /* Link in the new entry. */ 2888 l->l_prev = prev; 2889 l->l_next = prev->l_next; 2890 if (l->l_next != NULL) 2891 l->l_next->l_prev = l; 2892 prev->l_next = l; 2893 } 2894 2895 static void 2896 linkmap_delete(Obj_Entry *obj) 2897 { 2898 struct link_map *l = &obj->linkmap; 2899 2900 if (l->l_prev == NULL) { 2901 if ((r_debug.r_map = l->l_next) != NULL) 2902 l->l_next->l_prev = NULL; 2903 return; 2904 } 2905 2906 if ((l->l_prev->l_next = l->l_next) != NULL) 2907 l->l_next->l_prev = l->l_prev; 2908 } 2909 2910 /* 2911 * Function for the debugger to set a breakpoint on to gain control. 2912 * 2913 * The two parameters allow the debugger to easily find and determine 2914 * what the runtime loader is doing and to whom it is doing it. 2915 * 2916 * When the loadhook trap is hit (r_debug_state, set at program 2917 * initialization), the arguments can be found on the stack: 2918 * 2919 * +8 struct link_map *m 2920 * +4 struct r_debug *rd 2921 * +0 RetAddr 2922 */ 2923 void 2924 r_debug_state(struct r_debug* rd, struct link_map *m) 2925 { 2926 /* 2927 * The following is a hack to force the compiler to emit calls to 2928 * this function, even when optimizing. If the function is empty, 2929 * the compiler is not obliged to emit any code for calls to it, 2930 * even when marked __noinline. However, gdb depends on those 2931 * calls being made. 2932 */ 2933 __asm __volatile("" : : : "memory"); 2934 } 2935 2936 /* 2937 * Get address of the pointer variable in the main program. 2938 * Prefer non-weak symbol over the weak one. 2939 */ 2940 static const void ** 2941 get_program_var_addr(const char *name, RtldLockState *lockstate) 2942 { 2943 SymLook req; 2944 DoneList donelist; 2945 2946 symlook_init(&req, name); 2947 req.lockstate = lockstate; 2948 donelist_init(&donelist); 2949 if (symlook_global(&req, &donelist) != 0) 2950 return (NULL); 2951 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 2952 return ((const void **)make_function_pointer(req.sym_out, 2953 req.defobj_out)); 2954 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 2955 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 2956 else 2957 return ((const void **)(req.defobj_out->relocbase + 2958 req.sym_out->st_value)); 2959 } 2960 2961 /* 2962 * Set a pointer variable in the main program to the given value. This 2963 * is used to set key variables such as "environ" before any of the 2964 * init functions are called. 2965 */ 2966 static void 2967 set_program_var(const char *name, const void *value) 2968 { 2969 const void **addr; 2970 2971 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 2972 dbg("\"%s\": *%p <-- %p", name, addr, value); 2973 *addr = value; 2974 } 2975 } 2976 2977 /* 2978 * Search the global objects, including dependencies and main object, 2979 * for the given symbol. 2980 */ 2981 static int 2982 symlook_global(SymLook *req, DoneList *donelist) 2983 { 2984 SymLook req1; 2985 const Objlist_Entry *elm; 2986 int res; 2987 2988 symlook_init_from_req(&req1, req); 2989 2990 /* Search all objects loaded at program start up. */ 2991 if (req->defobj_out == NULL || 2992 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 2993 res = symlook_list(&req1, &list_main, donelist); 2994 if (res == 0 && (req->defobj_out == NULL || 2995 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 2996 req->sym_out = req1.sym_out; 2997 req->defobj_out = req1.defobj_out; 2998 assert(req->defobj_out != NULL); 2999 } 3000 } 3001 3002 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3003 STAILQ_FOREACH(elm, &list_global, link) { 3004 if (req->defobj_out != NULL && 3005 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3006 break; 3007 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3008 if (res == 0 && (req->defobj_out == NULL || 3009 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3010 req->sym_out = req1.sym_out; 3011 req->defobj_out = req1.defobj_out; 3012 assert(req->defobj_out != NULL); 3013 } 3014 } 3015 3016 return (req->sym_out != NULL ? 0 : ESRCH); 3017 } 3018 3019 /* 3020 * Given a symbol name in a referencing object, find the corresponding 3021 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3022 * no definition was found. Returns a pointer to the Obj_Entry of the 3023 * defining object via the reference parameter DEFOBJ_OUT. 3024 */ 3025 static int 3026 symlook_default(SymLook *req, const Obj_Entry *refobj) 3027 { 3028 DoneList donelist; 3029 const Objlist_Entry *elm; 3030 SymLook req1; 3031 int res; 3032 3033 donelist_init(&donelist); 3034 symlook_init_from_req(&req1, req); 3035 3036 /* Look first in the referencing object if linked symbolically. */ 3037 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3038 res = symlook_obj(&req1, refobj); 3039 if (res == 0) { 3040 req->sym_out = req1.sym_out; 3041 req->defobj_out = req1.defobj_out; 3042 assert(req->defobj_out != NULL); 3043 } 3044 } 3045 3046 symlook_global(req, &donelist); 3047 3048 /* Search all dlopened DAGs containing the referencing object. */ 3049 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3050 if (req->sym_out != NULL && 3051 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3052 break; 3053 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3054 if (res == 0 && (req->sym_out == NULL || 3055 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3056 req->sym_out = req1.sym_out; 3057 req->defobj_out = req1.defobj_out; 3058 assert(req->defobj_out != NULL); 3059 } 3060 } 3061 3062 /* 3063 * Search the dynamic linker itself, and possibly resolve the 3064 * symbol from there. This is how the application links to 3065 * dynamic linker services such as dlopen. 3066 */ 3067 if (req->sym_out == NULL || 3068 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3069 res = symlook_obj(&req1, &obj_rtld); 3070 if (res == 0) { 3071 req->sym_out = req1.sym_out; 3072 req->defobj_out = req1.defobj_out; 3073 assert(req->defobj_out != NULL); 3074 } 3075 } 3076 3077 return (req->sym_out != NULL ? 0 : ESRCH); 3078 } 3079 3080 static int 3081 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3082 { 3083 const Elf_Sym *def; 3084 const Obj_Entry *defobj; 3085 const Objlist_Entry *elm; 3086 SymLook req1; 3087 int res; 3088 3089 def = NULL; 3090 defobj = NULL; 3091 STAILQ_FOREACH(elm, objlist, link) { 3092 if (donelist_check(dlp, elm->obj)) 3093 continue; 3094 symlook_init_from_req(&req1, req); 3095 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3096 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3097 def = req1.sym_out; 3098 defobj = req1.defobj_out; 3099 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3100 break; 3101 } 3102 } 3103 } 3104 if (def != NULL) { 3105 req->sym_out = def; 3106 req->defobj_out = defobj; 3107 return (0); 3108 } 3109 return (ESRCH); 3110 } 3111 3112 /* 3113 * Search the chain of DAGS cointed to by the given Needed_Entry 3114 * for a symbol of the given name. Each DAG is scanned completely 3115 * before advancing to the next one. Returns a pointer to the symbol, 3116 * or NULL if no definition was found. 3117 */ 3118 static int 3119 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3120 { 3121 const Elf_Sym *def; 3122 const Needed_Entry *n; 3123 const Obj_Entry *defobj; 3124 SymLook req1; 3125 int res; 3126 3127 def = NULL; 3128 defobj = NULL; 3129 symlook_init_from_req(&req1, req); 3130 for (n = needed; n != NULL; n = n->next) { 3131 if (n->obj == NULL || 3132 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3133 continue; 3134 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3135 def = req1.sym_out; 3136 defobj = req1.defobj_out; 3137 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3138 break; 3139 } 3140 } 3141 if (def != NULL) { 3142 req->sym_out = def; 3143 req->defobj_out = defobj; 3144 return (0); 3145 } 3146 return (ESRCH); 3147 } 3148 3149 /* 3150 * Search the symbol table of a single shared object for a symbol of 3151 * the given name and version, if requested. Returns a pointer to the 3152 * symbol, or NULL if no definition was found. If the object is 3153 * filter, return filtered symbol from filtee. 3154 * 3155 * The symbol's hash value is passed in for efficiency reasons; that 3156 * eliminates many recomputations of the hash value. 3157 */ 3158 int 3159 symlook_obj(SymLook *req, const Obj_Entry *obj) 3160 { 3161 DoneList donelist; 3162 SymLook req1; 3163 int res, mres; 3164 3165 mres = symlook_obj1(req, obj); 3166 if (mres == 0) { 3167 if (obj->needed_filtees != NULL) { 3168 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate); 3169 donelist_init(&donelist); 3170 symlook_init_from_req(&req1, req); 3171 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3172 if (res == 0) { 3173 req->sym_out = req1.sym_out; 3174 req->defobj_out = req1.defobj_out; 3175 } 3176 return (res); 3177 } 3178 if (obj->needed_aux_filtees != NULL) { 3179 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate); 3180 donelist_init(&donelist); 3181 symlook_init_from_req(&req1, req); 3182 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3183 if (res == 0) { 3184 req->sym_out = req1.sym_out; 3185 req->defobj_out = req1.defobj_out; 3186 return (res); 3187 } 3188 } 3189 } 3190 return (mres); 3191 } 3192 3193 static int 3194 symlook_obj1(SymLook *req, const Obj_Entry *obj) 3195 { 3196 unsigned long symnum; 3197 const Elf_Sym *vsymp; 3198 Elf_Versym verndx; 3199 int vcount; 3200 3201 if (obj->buckets == NULL) 3202 return (ESRCH); 3203 3204 vsymp = NULL; 3205 vcount = 0; 3206 symnum = obj->buckets[req->hash % obj->nbuckets]; 3207 3208 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3209 const Elf_Sym *symp; 3210 const char *strp; 3211 3212 if (symnum >= obj->nchains) 3213 return (ESRCH); /* Bad object */ 3214 3215 symp = obj->symtab + symnum; 3216 strp = obj->strtab + symp->st_name; 3217 3218 switch (ELF_ST_TYPE(symp->st_info)) { 3219 case STT_FUNC: 3220 case STT_NOTYPE: 3221 case STT_OBJECT: 3222 case STT_GNU_IFUNC: 3223 if (symp->st_value == 0) 3224 continue; 3225 /* fallthrough */ 3226 case STT_TLS: 3227 if (symp->st_shndx != SHN_UNDEF) 3228 break; 3229 #ifndef __mips__ 3230 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3231 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3232 break; 3233 /* fallthrough */ 3234 #endif 3235 default: 3236 continue; 3237 } 3238 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3239 continue; 3240 3241 if (req->ventry == NULL) { 3242 if (obj->versyms != NULL) { 3243 verndx = VER_NDX(obj->versyms[symnum]); 3244 if (verndx > obj->vernum) { 3245 _rtld_error("%s: symbol %s references wrong version %d", 3246 obj->path, obj->strtab + symnum, verndx); 3247 continue; 3248 } 3249 /* 3250 * If we are not called from dlsym (i.e. this is a normal 3251 * relocation from unversioned binary), accept the symbol 3252 * immediately if it happens to have first version after 3253 * this shared object became versioned. Otherwise, if 3254 * symbol is versioned and not hidden, remember it. If it 3255 * is the only symbol with this name exported by the 3256 * shared object, it will be returned as a match at the 3257 * end of the function. If symbol is global (verndx < 2) 3258 * accept it unconditionally. 3259 */ 3260 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3261 verndx == VER_NDX_GIVEN) { 3262 req->sym_out = symp; 3263 req->defobj_out = obj; 3264 return (0); 3265 } 3266 else if (verndx >= VER_NDX_GIVEN) { 3267 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) { 3268 if (vsymp == NULL) 3269 vsymp = symp; 3270 vcount ++; 3271 } 3272 continue; 3273 } 3274 } 3275 req->sym_out = symp; 3276 req->defobj_out = obj; 3277 return (0); 3278 } else { 3279 if (obj->versyms == NULL) { 3280 if (object_match_name(obj, req->ventry->name)) { 3281 _rtld_error("%s: object %s should provide version %s for " 3282 "symbol %s", obj_rtld.path, obj->path, 3283 req->ventry->name, obj->strtab + symnum); 3284 continue; 3285 } 3286 } else { 3287 verndx = VER_NDX(obj->versyms[symnum]); 3288 if (verndx > obj->vernum) { 3289 _rtld_error("%s: symbol %s references wrong version %d", 3290 obj->path, obj->strtab + symnum, verndx); 3291 continue; 3292 } 3293 if (obj->vertab[verndx].hash != req->ventry->hash || 3294 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3295 /* 3296 * Version does not match. Look if this is a global symbol 3297 * and if it is not hidden. If global symbol (verndx < 2) 3298 * is available, use it. Do not return symbol if we are 3299 * called by dlvsym, because dlvsym looks for a specific 3300 * version and default one is not what dlvsym wants. 3301 */ 3302 if ((req->flags & SYMLOOK_DLSYM) || 3303 (obj->versyms[symnum] & VER_NDX_HIDDEN) || 3304 (verndx >= VER_NDX_GIVEN)) 3305 continue; 3306 } 3307 } 3308 req->sym_out = symp; 3309 req->defobj_out = obj; 3310 return (0); 3311 } 3312 } 3313 if (vcount == 1) { 3314 req->sym_out = vsymp; 3315 req->defobj_out = obj; 3316 return (0); 3317 } 3318 return (ESRCH); 3319 } 3320 3321 static void 3322 trace_loaded_objects(Obj_Entry *obj) 3323 { 3324 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3325 int c; 3326 3327 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3328 main_local = ""; 3329 3330 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3331 fmt1 = "\t%o => %p (%x)\n"; 3332 3333 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3334 fmt2 = "\t%o (%x)\n"; 3335 3336 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3337 3338 for (; obj; obj = obj->next) { 3339 Needed_Entry *needed; 3340 char *name, *path; 3341 bool is_lib; 3342 3343 if (list_containers && obj->needed != NULL) 3344 rtld_printf("%s:\n", obj->path); 3345 for (needed = obj->needed; needed; needed = needed->next) { 3346 if (needed->obj != NULL) { 3347 if (needed->obj->traced && !list_containers) 3348 continue; 3349 needed->obj->traced = true; 3350 path = needed->obj->path; 3351 } else 3352 path = "not found"; 3353 3354 name = (char *)obj->strtab + needed->name; 3355 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 3356 3357 fmt = is_lib ? fmt1 : fmt2; 3358 while ((c = *fmt++) != '\0') { 3359 switch (c) { 3360 default: 3361 rtld_putchar(c); 3362 continue; 3363 case '\\': 3364 switch (c = *fmt) { 3365 case '\0': 3366 continue; 3367 case 'n': 3368 rtld_putchar('\n'); 3369 break; 3370 case 't': 3371 rtld_putchar('\t'); 3372 break; 3373 } 3374 break; 3375 case '%': 3376 switch (c = *fmt) { 3377 case '\0': 3378 continue; 3379 case '%': 3380 default: 3381 rtld_putchar(c); 3382 break; 3383 case 'A': 3384 rtld_putstr(main_local); 3385 break; 3386 case 'a': 3387 rtld_putstr(obj_main->path); 3388 break; 3389 case 'o': 3390 rtld_putstr(name); 3391 break; 3392 #if 0 3393 case 'm': 3394 rtld_printf("%d", sodp->sod_major); 3395 break; 3396 case 'n': 3397 rtld_printf("%d", sodp->sod_minor); 3398 break; 3399 #endif 3400 case 'p': 3401 rtld_putstr(path); 3402 break; 3403 case 'x': 3404 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 3405 0); 3406 break; 3407 } 3408 break; 3409 } 3410 ++fmt; 3411 } 3412 } 3413 } 3414 } 3415 3416 /* 3417 * Unload a dlopened object and its dependencies from memory and from 3418 * our data structures. It is assumed that the DAG rooted in the 3419 * object has already been unreferenced, and that the object has a 3420 * reference count of 0. 3421 */ 3422 static void 3423 unload_object(Obj_Entry *root) 3424 { 3425 Obj_Entry *obj; 3426 Obj_Entry **linkp; 3427 3428 assert(root->refcount == 0); 3429 3430 /* 3431 * Pass over the DAG removing unreferenced objects from 3432 * appropriate lists. 3433 */ 3434 unlink_object(root); 3435 3436 /* Unmap all objects that are no longer referenced. */ 3437 linkp = &obj_list->next; 3438 while ((obj = *linkp) != NULL) { 3439 if (obj->refcount == 0) { 3440 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3441 obj->path); 3442 dbg("unloading \"%s\"", obj->path); 3443 unload_filtees(root); 3444 munmap(obj->mapbase, obj->mapsize); 3445 linkmap_delete(obj); 3446 *linkp = obj->next; 3447 obj_count--; 3448 obj_free(obj); 3449 } else 3450 linkp = &obj->next; 3451 } 3452 obj_tail = linkp; 3453 } 3454 3455 static void 3456 unlink_object(Obj_Entry *root) 3457 { 3458 Objlist_Entry *elm; 3459 3460 if (root->refcount == 0) { 3461 /* Remove the object from the RTLD_GLOBAL list. */ 3462 objlist_remove(&list_global, root); 3463 3464 /* Remove the object from all objects' DAG lists. */ 3465 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3466 objlist_remove(&elm->obj->dldags, root); 3467 if (elm->obj != root) 3468 unlink_object(elm->obj); 3469 } 3470 } 3471 } 3472 3473 static void 3474 ref_dag(Obj_Entry *root) 3475 { 3476 Objlist_Entry *elm; 3477 3478 assert(root->dag_inited); 3479 STAILQ_FOREACH(elm, &root->dagmembers, link) 3480 elm->obj->refcount++; 3481 } 3482 3483 static void 3484 unref_dag(Obj_Entry *root) 3485 { 3486 Objlist_Entry *elm; 3487 3488 assert(root->dag_inited); 3489 STAILQ_FOREACH(elm, &root->dagmembers, link) 3490 elm->obj->refcount--; 3491 } 3492 3493 /* 3494 * Common code for MD __tls_get_addr(). 3495 */ 3496 void * 3497 tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset) 3498 { 3499 Elf_Addr* dtv = *dtvp; 3500 RtldLockState lockstate; 3501 3502 /* Check dtv generation in case new modules have arrived */ 3503 if (dtv[0] != tls_dtv_generation) { 3504 Elf_Addr* newdtv; 3505 int to_copy; 3506 3507 wlock_acquire(rtld_bind_lock, &lockstate); 3508 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); 3509 to_copy = dtv[1]; 3510 if (to_copy > tls_max_index) 3511 to_copy = tls_max_index; 3512 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 3513 newdtv[0] = tls_dtv_generation; 3514 newdtv[1] = tls_max_index; 3515 free(dtv); 3516 lock_release(rtld_bind_lock, &lockstate); 3517 dtv = *dtvp = newdtv; 3518 } 3519 3520 /* Dynamically allocate module TLS if necessary */ 3521 if (!dtv[index + 1]) { 3522 /* Signal safe, wlock will block out signals. */ 3523 wlock_acquire(rtld_bind_lock, &lockstate); 3524 if (!dtv[index + 1]) 3525 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 3526 lock_release(rtld_bind_lock, &lockstate); 3527 } 3528 return (void*) (dtv[index + 1] + offset); 3529 } 3530 3531 /* XXX not sure what variants to use for arm. */ 3532 3533 #if defined(__ia64__) || defined(__powerpc__) 3534 3535 /* 3536 * Allocate Static TLS using the Variant I method. 3537 */ 3538 void * 3539 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 3540 { 3541 Obj_Entry *obj; 3542 char *tcb; 3543 Elf_Addr **tls; 3544 Elf_Addr *dtv; 3545 Elf_Addr addr; 3546 int i; 3547 3548 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 3549 return (oldtcb); 3550 3551 assert(tcbsize >= TLS_TCB_SIZE); 3552 tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 3553 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 3554 3555 if (oldtcb != NULL) { 3556 memcpy(tls, oldtcb, tls_static_space); 3557 free(oldtcb); 3558 3559 /* Adjust the DTV. */ 3560 dtv = tls[0]; 3561 for (i = 0; i < dtv[1]; i++) { 3562 if (dtv[i+2] >= (Elf_Addr)oldtcb && 3563 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 3564 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 3565 } 3566 } 3567 } else { 3568 dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr)); 3569 tls[0] = dtv; 3570 dtv[0] = tls_dtv_generation; 3571 dtv[1] = tls_max_index; 3572 3573 for (obj = objs; obj; obj = obj->next) { 3574 if (obj->tlsoffset > 0) { 3575 addr = (Elf_Addr)tls + obj->tlsoffset; 3576 if (obj->tlsinitsize > 0) 3577 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 3578 if (obj->tlssize > obj->tlsinitsize) 3579 memset((void*) (addr + obj->tlsinitsize), 0, 3580 obj->tlssize - obj->tlsinitsize); 3581 dtv[obj->tlsindex + 1] = addr; 3582 } 3583 } 3584 } 3585 3586 return (tcb); 3587 } 3588 3589 void 3590 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 3591 { 3592 Elf_Addr *dtv; 3593 Elf_Addr tlsstart, tlsend; 3594 int dtvsize, i; 3595 3596 assert(tcbsize >= TLS_TCB_SIZE); 3597 3598 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 3599 tlsend = tlsstart + tls_static_space; 3600 3601 dtv = *(Elf_Addr **)tlsstart; 3602 dtvsize = dtv[1]; 3603 for (i = 0; i < dtvsize; i++) { 3604 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 3605 free((void*)dtv[i+2]); 3606 } 3607 } 3608 free(dtv); 3609 free(tcb); 3610 } 3611 3612 #endif 3613 3614 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \ 3615 defined(__arm__) || defined(__mips__) 3616 3617 /* 3618 * Allocate Static TLS using the Variant II method. 3619 */ 3620 void * 3621 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 3622 { 3623 Obj_Entry *obj; 3624 size_t size; 3625 char *tls; 3626 Elf_Addr *dtv, *olddtv; 3627 Elf_Addr segbase, oldsegbase, addr; 3628 int i; 3629 3630 size = round(tls_static_space, tcbalign); 3631 3632 assert(tcbsize >= 2*sizeof(Elf_Addr)); 3633 tls = calloc(1, size + tcbsize); 3634 dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); 3635 3636 segbase = (Elf_Addr)(tls + size); 3637 ((Elf_Addr*)segbase)[0] = segbase; 3638 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 3639 3640 dtv[0] = tls_dtv_generation; 3641 dtv[1] = tls_max_index; 3642 3643 if (oldtls) { 3644 /* 3645 * Copy the static TLS block over whole. 3646 */ 3647 oldsegbase = (Elf_Addr) oldtls; 3648 memcpy((void *)(segbase - tls_static_space), 3649 (const void *)(oldsegbase - tls_static_space), 3650 tls_static_space); 3651 3652 /* 3653 * If any dynamic TLS blocks have been created tls_get_addr(), 3654 * move them over. 3655 */ 3656 olddtv = ((Elf_Addr**)oldsegbase)[1]; 3657 for (i = 0; i < olddtv[1]; i++) { 3658 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 3659 dtv[i+2] = olddtv[i+2]; 3660 olddtv[i+2] = 0; 3661 } 3662 } 3663 3664 /* 3665 * We assume that this block was the one we created with 3666 * allocate_initial_tls(). 3667 */ 3668 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 3669 } else { 3670 for (obj = objs; obj; obj = obj->next) { 3671 if (obj->tlsoffset) { 3672 addr = segbase - obj->tlsoffset; 3673 memset((void*) (addr + obj->tlsinitsize), 3674 0, obj->tlssize - obj->tlsinitsize); 3675 if (obj->tlsinit) 3676 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 3677 dtv[obj->tlsindex + 1] = addr; 3678 } 3679 } 3680 } 3681 3682 return (void*) segbase; 3683 } 3684 3685 void 3686 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 3687 { 3688 size_t size; 3689 Elf_Addr* dtv; 3690 int dtvsize, i; 3691 Elf_Addr tlsstart, tlsend; 3692 3693 /* 3694 * Figure out the size of the initial TLS block so that we can 3695 * find stuff which ___tls_get_addr() allocated dynamically. 3696 */ 3697 size = round(tls_static_space, tcbalign); 3698 3699 dtv = ((Elf_Addr**)tls)[1]; 3700 dtvsize = dtv[1]; 3701 tlsend = (Elf_Addr) tls; 3702 tlsstart = tlsend - size; 3703 for (i = 0; i < dtvsize; i++) { 3704 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 3705 free((void*) dtv[i+2]); 3706 } 3707 } 3708 3709 free((void*) tlsstart); 3710 free((void*) dtv); 3711 } 3712 3713 #endif 3714 3715 /* 3716 * Allocate TLS block for module with given index. 3717 */ 3718 void * 3719 allocate_module_tls(int index) 3720 { 3721 Obj_Entry* obj; 3722 char* p; 3723 3724 for (obj = obj_list; obj; obj = obj->next) { 3725 if (obj->tlsindex == index) 3726 break; 3727 } 3728 if (!obj) { 3729 _rtld_error("Can't find module with TLS index %d", index); 3730 die(); 3731 } 3732 3733 p = malloc(obj->tlssize); 3734 if (p == NULL) { 3735 _rtld_error("Cannot allocate TLS block for index %d", index); 3736 die(); 3737 } 3738 memcpy(p, obj->tlsinit, obj->tlsinitsize); 3739 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 3740 3741 return p; 3742 } 3743 3744 bool 3745 allocate_tls_offset(Obj_Entry *obj) 3746 { 3747 size_t off; 3748 3749 if (obj->tls_done) 3750 return true; 3751 3752 if (obj->tlssize == 0) { 3753 obj->tls_done = true; 3754 return true; 3755 } 3756 3757 if (obj->tlsindex == 1) 3758 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 3759 else 3760 off = calculate_tls_offset(tls_last_offset, tls_last_size, 3761 obj->tlssize, obj->tlsalign); 3762 3763 /* 3764 * If we have already fixed the size of the static TLS block, we 3765 * must stay within that size. When allocating the static TLS, we 3766 * leave a small amount of space spare to be used for dynamically 3767 * loading modules which use static TLS. 3768 */ 3769 if (tls_static_space) { 3770 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 3771 return false; 3772 } 3773 3774 tls_last_offset = obj->tlsoffset = off; 3775 tls_last_size = obj->tlssize; 3776 obj->tls_done = true; 3777 3778 return true; 3779 } 3780 3781 void 3782 free_tls_offset(Obj_Entry *obj) 3783 { 3784 3785 /* 3786 * If we were the last thing to allocate out of the static TLS 3787 * block, we give our space back to the 'allocator'. This is a 3788 * simplistic workaround to allow libGL.so.1 to be loaded and 3789 * unloaded multiple times. 3790 */ 3791 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 3792 == calculate_tls_end(tls_last_offset, tls_last_size)) { 3793 tls_last_offset -= obj->tlssize; 3794 tls_last_size = 0; 3795 } 3796 } 3797 3798 void * 3799 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 3800 { 3801 void *ret; 3802 RtldLockState lockstate; 3803 3804 wlock_acquire(rtld_bind_lock, &lockstate); 3805 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 3806 lock_release(rtld_bind_lock, &lockstate); 3807 return (ret); 3808 } 3809 3810 void 3811 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 3812 { 3813 RtldLockState lockstate; 3814 3815 wlock_acquire(rtld_bind_lock, &lockstate); 3816 free_tls(tcb, tcbsize, tcbalign); 3817 lock_release(rtld_bind_lock, &lockstate); 3818 } 3819 3820 static void 3821 object_add_name(Obj_Entry *obj, const char *name) 3822 { 3823 Name_Entry *entry; 3824 size_t len; 3825 3826 len = strlen(name); 3827 entry = malloc(sizeof(Name_Entry) + len); 3828 3829 if (entry != NULL) { 3830 strcpy(entry->name, name); 3831 STAILQ_INSERT_TAIL(&obj->names, entry, link); 3832 } 3833 } 3834 3835 static int 3836 object_match_name(const Obj_Entry *obj, const char *name) 3837 { 3838 Name_Entry *entry; 3839 3840 STAILQ_FOREACH(entry, &obj->names, link) { 3841 if (strcmp(name, entry->name) == 0) 3842 return (1); 3843 } 3844 return (0); 3845 } 3846 3847 static Obj_Entry * 3848 locate_dependency(const Obj_Entry *obj, const char *name) 3849 { 3850 const Objlist_Entry *entry; 3851 const Needed_Entry *needed; 3852 3853 STAILQ_FOREACH(entry, &list_main, link) { 3854 if (object_match_name(entry->obj, name)) 3855 return entry->obj; 3856 } 3857 3858 for (needed = obj->needed; needed != NULL; needed = needed->next) { 3859 if (strcmp(obj->strtab + needed->name, name) == 0 || 3860 (needed->obj != NULL && object_match_name(needed->obj, name))) { 3861 /* 3862 * If there is DT_NEEDED for the name we are looking for, 3863 * we are all set. Note that object might not be found if 3864 * dependency was not loaded yet, so the function can 3865 * return NULL here. This is expected and handled 3866 * properly by the caller. 3867 */ 3868 return (needed->obj); 3869 } 3870 } 3871 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 3872 obj->path, name); 3873 die(); 3874 } 3875 3876 static int 3877 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 3878 const Elf_Vernaux *vna) 3879 { 3880 const Elf_Verdef *vd; 3881 const char *vername; 3882 3883 vername = refobj->strtab + vna->vna_name; 3884 vd = depobj->verdef; 3885 if (vd == NULL) { 3886 _rtld_error("%s: version %s required by %s not defined", 3887 depobj->path, vername, refobj->path); 3888 return (-1); 3889 } 3890 for (;;) { 3891 if (vd->vd_version != VER_DEF_CURRENT) { 3892 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 3893 depobj->path, vd->vd_version); 3894 return (-1); 3895 } 3896 if (vna->vna_hash == vd->vd_hash) { 3897 const Elf_Verdaux *aux = (const Elf_Verdaux *) 3898 ((char *)vd + vd->vd_aux); 3899 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 3900 return (0); 3901 } 3902 if (vd->vd_next == 0) 3903 break; 3904 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3905 } 3906 if (vna->vna_flags & VER_FLG_WEAK) 3907 return (0); 3908 _rtld_error("%s: version %s required by %s not found", 3909 depobj->path, vername, refobj->path); 3910 return (-1); 3911 } 3912 3913 static int 3914 rtld_verify_object_versions(Obj_Entry *obj) 3915 { 3916 const Elf_Verneed *vn; 3917 const Elf_Verdef *vd; 3918 const Elf_Verdaux *vda; 3919 const Elf_Vernaux *vna; 3920 const Obj_Entry *depobj; 3921 int maxvernum, vernum; 3922 3923 maxvernum = 0; 3924 /* 3925 * Walk over defined and required version records and figure out 3926 * max index used by any of them. Do very basic sanity checking 3927 * while there. 3928 */ 3929 vn = obj->verneed; 3930 while (vn != NULL) { 3931 if (vn->vn_version != VER_NEED_CURRENT) { 3932 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 3933 obj->path, vn->vn_version); 3934 return (-1); 3935 } 3936 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 3937 for (;;) { 3938 vernum = VER_NEED_IDX(vna->vna_other); 3939 if (vernum > maxvernum) 3940 maxvernum = vernum; 3941 if (vna->vna_next == 0) 3942 break; 3943 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 3944 } 3945 if (vn->vn_next == 0) 3946 break; 3947 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 3948 } 3949 3950 vd = obj->verdef; 3951 while (vd != NULL) { 3952 if (vd->vd_version != VER_DEF_CURRENT) { 3953 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 3954 obj->path, vd->vd_version); 3955 return (-1); 3956 } 3957 vernum = VER_DEF_IDX(vd->vd_ndx); 3958 if (vernum > maxvernum) 3959 maxvernum = vernum; 3960 if (vd->vd_next == 0) 3961 break; 3962 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3963 } 3964 3965 if (maxvernum == 0) 3966 return (0); 3967 3968 /* 3969 * Store version information in array indexable by version index. 3970 * Verify that object version requirements are satisfied along the 3971 * way. 3972 */ 3973 obj->vernum = maxvernum + 1; 3974 obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry)); 3975 3976 vd = obj->verdef; 3977 while (vd != NULL) { 3978 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 3979 vernum = VER_DEF_IDX(vd->vd_ndx); 3980 assert(vernum <= maxvernum); 3981 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 3982 obj->vertab[vernum].hash = vd->vd_hash; 3983 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 3984 obj->vertab[vernum].file = NULL; 3985 obj->vertab[vernum].flags = 0; 3986 } 3987 if (vd->vd_next == 0) 3988 break; 3989 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3990 } 3991 3992 vn = obj->verneed; 3993 while (vn != NULL) { 3994 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 3995 if (depobj == NULL) 3996 return (-1); 3997 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 3998 for (;;) { 3999 if (check_object_provided_version(obj, depobj, vna)) 4000 return (-1); 4001 vernum = VER_NEED_IDX(vna->vna_other); 4002 assert(vernum <= maxvernum); 4003 obj->vertab[vernum].hash = vna->vna_hash; 4004 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4005 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4006 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4007 VER_INFO_HIDDEN : 0; 4008 if (vna->vna_next == 0) 4009 break; 4010 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4011 } 4012 if (vn->vn_next == 0) 4013 break; 4014 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4015 } 4016 return 0; 4017 } 4018 4019 static int 4020 rtld_verify_versions(const Objlist *objlist) 4021 { 4022 Objlist_Entry *entry; 4023 int rc; 4024 4025 rc = 0; 4026 STAILQ_FOREACH(entry, objlist, link) { 4027 /* 4028 * Skip dummy objects or objects that have their version requirements 4029 * already checked. 4030 */ 4031 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4032 continue; 4033 if (rtld_verify_object_versions(entry->obj) == -1) { 4034 rc = -1; 4035 if (ld_tracing == NULL) 4036 break; 4037 } 4038 } 4039 if (rc == 0 || ld_tracing != NULL) 4040 rc = rtld_verify_object_versions(&obj_rtld); 4041 return rc; 4042 } 4043 4044 const Ver_Entry * 4045 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4046 { 4047 Elf_Versym vernum; 4048 4049 if (obj->vertab) { 4050 vernum = VER_NDX(obj->versyms[symnum]); 4051 if (vernum >= obj->vernum) { 4052 _rtld_error("%s: symbol %s has wrong verneed value %d", 4053 obj->path, obj->strtab + symnum, vernum); 4054 } else if (obj->vertab[vernum].hash != 0) { 4055 return &obj->vertab[vernum]; 4056 } 4057 } 4058 return NULL; 4059 } 4060 4061 int 4062 _rtld_get_stack_prot(void) 4063 { 4064 4065 return (stack_prot); 4066 } 4067 4068 static void 4069 map_stacks_exec(RtldLockState *lockstate) 4070 { 4071 void (*thr_map_stacks_exec)(void); 4072 4073 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4074 return; 4075 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4076 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4077 if (thr_map_stacks_exec != NULL) { 4078 stack_prot |= PROT_EXEC; 4079 thr_map_stacks_exec(); 4080 } 4081 } 4082 4083 void 4084 symlook_init(SymLook *dst, const char *name) 4085 { 4086 4087 bzero(dst, sizeof(*dst)); 4088 dst->name = name; 4089 dst->hash = elf_hash(name); 4090 } 4091 4092 static void 4093 symlook_init_from_req(SymLook *dst, const SymLook *src) 4094 { 4095 4096 dst->name = src->name; 4097 dst->hash = src->hash; 4098 dst->ventry = src->ventry; 4099 dst->flags = src->flags; 4100 dst->defobj_out = NULL; 4101 dst->sym_out = NULL; 4102 dst->lockstate = src->lockstate; 4103 } 4104 4105 /* 4106 * Overrides for libc_pic-provided functions. 4107 */ 4108 4109 int 4110 __getosreldate(void) 4111 { 4112 size_t len; 4113 int oid[2]; 4114 int error, osrel; 4115 4116 if (osreldate != 0) 4117 return (osreldate); 4118 4119 oid[0] = CTL_KERN; 4120 oid[1] = KERN_OSRELDATE; 4121 osrel = 0; 4122 len = sizeof(osrel); 4123 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4124 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4125 osreldate = osrel; 4126 return (osreldate); 4127 } 4128 4129 /* 4130 * No unresolved symbols for rtld. 4131 */ 4132 void 4133 __pthread_cxa_finalize(struct dl_phdr_info *a) 4134 { 4135 } 4136