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 case PT_GNU_RELRO: 1119 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1120 obj->relro_size = round_page(ph->p_memsz); 1121 break; 1122 } 1123 } 1124 if (nsegs < 1) { 1125 _rtld_error("%s: too few PT_LOAD segments", path); 1126 return NULL; 1127 } 1128 1129 obj->entry = entry; 1130 return obj; 1131 } 1132 1133 static Obj_Entry * 1134 dlcheck(void *handle) 1135 { 1136 Obj_Entry *obj; 1137 1138 for (obj = obj_list; obj != NULL; obj = obj->next) 1139 if (obj == (Obj_Entry *) handle) 1140 break; 1141 1142 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1143 _rtld_error("Invalid shared object handle %p", handle); 1144 return NULL; 1145 } 1146 return obj; 1147 } 1148 1149 /* 1150 * If the given object is already in the donelist, return true. Otherwise 1151 * add the object to the list and return false. 1152 */ 1153 static bool 1154 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1155 { 1156 unsigned int i; 1157 1158 for (i = 0; i < dlp->num_used; i++) 1159 if (dlp->objs[i] == obj) 1160 return true; 1161 /* 1162 * Our donelist allocation should always be sufficient. But if 1163 * our threads locking isn't working properly, more shared objects 1164 * could have been loaded since we allocated the list. That should 1165 * never happen, but we'll handle it properly just in case it does. 1166 */ 1167 if (dlp->num_used < dlp->num_alloc) 1168 dlp->objs[dlp->num_used++] = obj; 1169 return false; 1170 } 1171 1172 /* 1173 * Hash function for symbol table lookup. Don't even think about changing 1174 * this. It is specified by the System V ABI. 1175 */ 1176 unsigned long 1177 elf_hash(const char *name) 1178 { 1179 const unsigned char *p = (const unsigned char *) name; 1180 unsigned long h = 0; 1181 unsigned long g; 1182 1183 while (*p != '\0') { 1184 h = (h << 4) + *p++; 1185 if ((g = h & 0xf0000000) != 0) 1186 h ^= g >> 24; 1187 h &= ~g; 1188 } 1189 return h; 1190 } 1191 1192 /* 1193 * Find the library with the given name, and return its full pathname. 1194 * The returned string is dynamically allocated. Generates an error 1195 * message and returns NULL if the library cannot be found. 1196 * 1197 * If the second argument is non-NULL, then it refers to an already- 1198 * loaded shared object, whose library search path will be searched. 1199 * 1200 * The search order is: 1201 * LD_LIBRARY_PATH 1202 * rpath in the referencing file 1203 * ldconfig hints 1204 * /lib:/usr/lib 1205 */ 1206 static char * 1207 find_library(const char *xname, const Obj_Entry *refobj) 1208 { 1209 char *pathname; 1210 char *name; 1211 1212 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1213 if (xname[0] != '/' && !trust) { 1214 _rtld_error("Absolute pathname required for shared object \"%s\"", 1215 xname); 1216 return NULL; 1217 } 1218 if (refobj != NULL && refobj->z_origin) 1219 return origin_subst(xname, refobj->origin_path); 1220 else 1221 return xstrdup(xname); 1222 } 1223 1224 if (libmap_disable || (refobj == NULL) || 1225 (name = lm_find(refobj->path, xname)) == NULL) 1226 name = (char *)xname; 1227 1228 dbg(" Searching for \"%s\"", name); 1229 1230 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1231 (refobj != NULL && 1232 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1233 (pathname = search_library_path(name, gethints())) != NULL || 1234 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1235 return pathname; 1236 1237 if(refobj != NULL && refobj->path != NULL) { 1238 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1239 name, basename(refobj->path)); 1240 } else { 1241 _rtld_error("Shared object \"%s\" not found", name); 1242 } 1243 return NULL; 1244 } 1245 1246 /* 1247 * Given a symbol number in a referencing object, find the corresponding 1248 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1249 * no definition was found. Returns a pointer to the Obj_Entry of the 1250 * defining object via the reference parameter DEFOBJ_OUT. 1251 */ 1252 const Elf_Sym * 1253 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1254 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1255 RtldLockState *lockstate) 1256 { 1257 const Elf_Sym *ref; 1258 const Elf_Sym *def; 1259 const Obj_Entry *defobj; 1260 SymLook req; 1261 const char *name; 1262 int res; 1263 1264 /* 1265 * If we have already found this symbol, get the information from 1266 * the cache. 1267 */ 1268 if (symnum >= refobj->nchains) 1269 return NULL; /* Bad object */ 1270 if (cache != NULL && cache[symnum].sym != NULL) { 1271 *defobj_out = cache[symnum].obj; 1272 return cache[symnum].sym; 1273 } 1274 1275 ref = refobj->symtab + symnum; 1276 name = refobj->strtab + ref->st_name; 1277 def = NULL; 1278 defobj = NULL; 1279 1280 /* 1281 * We don't have to do a full scale lookup if the symbol is local. 1282 * We know it will bind to the instance in this load module; to 1283 * which we already have a pointer (ie ref). By not doing a lookup, 1284 * we not only improve performance, but it also avoids unresolvable 1285 * symbols when local symbols are not in the hash table. This has 1286 * been seen with the ia64 toolchain. 1287 */ 1288 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1289 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1290 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1291 symnum); 1292 } 1293 symlook_init(&req, name); 1294 req.flags = flags; 1295 req.ventry = fetch_ventry(refobj, symnum); 1296 req.lockstate = lockstate; 1297 res = symlook_default(&req, refobj); 1298 if (res == 0) { 1299 def = req.sym_out; 1300 defobj = req.defobj_out; 1301 } 1302 } else { 1303 def = ref; 1304 defobj = refobj; 1305 } 1306 1307 /* 1308 * If we found no definition and the reference is weak, treat the 1309 * symbol as having the value zero. 1310 */ 1311 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1312 def = &sym_zero; 1313 defobj = obj_main; 1314 } 1315 1316 if (def != NULL) { 1317 *defobj_out = defobj; 1318 /* Record the information in the cache to avoid subsequent lookups. */ 1319 if (cache != NULL) { 1320 cache[symnum].sym = def; 1321 cache[symnum].obj = defobj; 1322 } 1323 } else { 1324 if (refobj != &obj_rtld) 1325 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1326 } 1327 return def; 1328 } 1329 1330 /* 1331 * Return the search path from the ldconfig hints file, reading it if 1332 * necessary. Returns NULL if there are problems with the hints file, 1333 * or if the search path there is empty. 1334 */ 1335 static const char * 1336 gethints(void) 1337 { 1338 static char *hints; 1339 1340 if (hints == NULL) { 1341 int fd; 1342 struct elfhints_hdr hdr; 1343 char *p; 1344 1345 /* Keep from trying again in case the hints file is bad. */ 1346 hints = ""; 1347 1348 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1) 1349 return NULL; 1350 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1351 hdr.magic != ELFHINTS_MAGIC || 1352 hdr.version != 1) { 1353 close(fd); 1354 return NULL; 1355 } 1356 p = xmalloc(hdr.dirlistlen + 1); 1357 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1358 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) { 1359 free(p); 1360 close(fd); 1361 return NULL; 1362 } 1363 hints = p; 1364 close(fd); 1365 } 1366 return hints[0] != '\0' ? hints : NULL; 1367 } 1368 1369 static void 1370 init_dag(Obj_Entry *root) 1371 { 1372 const Needed_Entry *needed; 1373 const Objlist_Entry *elm; 1374 DoneList donelist; 1375 1376 if (root->dag_inited) 1377 return; 1378 donelist_init(&donelist); 1379 1380 /* Root object belongs to own DAG. */ 1381 objlist_push_tail(&root->dldags, root); 1382 objlist_push_tail(&root->dagmembers, root); 1383 donelist_check(&donelist, root); 1384 1385 /* 1386 * Add dependencies of root object to DAG in breadth order 1387 * by exploiting the fact that each new object get added 1388 * to the tail of the dagmembers list. 1389 */ 1390 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1391 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1392 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1393 continue; 1394 objlist_push_tail(&needed->obj->dldags, root); 1395 objlist_push_tail(&root->dagmembers, needed->obj); 1396 } 1397 } 1398 root->dag_inited = true; 1399 } 1400 1401 /* 1402 * Initialize the dynamic linker. The argument is the address at which 1403 * the dynamic linker has been mapped into memory. The primary task of 1404 * this function is to relocate the dynamic linker. 1405 */ 1406 static void 1407 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1408 { 1409 Obj_Entry objtmp; /* Temporary rtld object */ 1410 const Elf_Dyn *dyn_rpath; 1411 const Elf_Dyn *dyn_soname; 1412 1413 /* 1414 * Conjure up an Obj_Entry structure for the dynamic linker. 1415 * 1416 * The "path" member can't be initialized yet because string constants 1417 * cannot yet be accessed. Below we will set it correctly. 1418 */ 1419 memset(&objtmp, 0, sizeof(objtmp)); 1420 objtmp.path = NULL; 1421 objtmp.rtld = true; 1422 objtmp.mapbase = mapbase; 1423 #ifdef PIC 1424 objtmp.relocbase = mapbase; 1425 #endif 1426 if (RTLD_IS_DYNAMIC()) { 1427 objtmp.dynamic = rtld_dynamic(&objtmp); 1428 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname); 1429 assert(objtmp.needed == NULL); 1430 #if !defined(__mips__) 1431 /* MIPS has a bogus DT_TEXTREL. */ 1432 assert(!objtmp.textrel); 1433 #endif 1434 1435 /* 1436 * Temporarily put the dynamic linker entry into the object list, so 1437 * that symbols can be found. 1438 */ 1439 1440 relocate_objects(&objtmp, true, &objtmp, NULL); 1441 } 1442 1443 /* Initialize the object list. */ 1444 obj_tail = &obj_list; 1445 1446 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1447 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1448 1449 if (aux_info[AT_PAGESZ] != NULL) 1450 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1451 if (aux_info[AT_OSRELDATE] != NULL) 1452 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1453 1454 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname); 1455 1456 /* Replace the path with a dynamically allocated copy. */ 1457 obj_rtld.path = xstrdup(PATH_RTLD); 1458 1459 r_debug.r_brk = r_debug_state; 1460 r_debug.r_state = RT_CONSISTENT; 1461 } 1462 1463 /* 1464 * Add the init functions from a needed object list (and its recursive 1465 * needed objects) to "list". This is not used directly; it is a helper 1466 * function for initlist_add_objects(). The write lock must be held 1467 * when this function is called. 1468 */ 1469 static void 1470 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1471 { 1472 /* Recursively process the successor needed objects. */ 1473 if (needed->next != NULL) 1474 initlist_add_neededs(needed->next, list); 1475 1476 /* Process the current needed object. */ 1477 if (needed->obj != NULL) 1478 initlist_add_objects(needed->obj, &needed->obj->next, list); 1479 } 1480 1481 /* 1482 * Scan all of the DAGs rooted in the range of objects from "obj" to 1483 * "tail" and add their init functions to "list". This recurses over 1484 * the DAGs and ensure the proper init ordering such that each object's 1485 * needed libraries are initialized before the object itself. At the 1486 * same time, this function adds the objects to the global finalization 1487 * list "list_fini" in the opposite order. The write lock must be 1488 * held when this function is called. 1489 */ 1490 static void 1491 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1492 { 1493 if (obj->init_scanned || obj->init_done) 1494 return; 1495 obj->init_scanned = true; 1496 1497 /* Recursively process the successor objects. */ 1498 if (&obj->next != tail) 1499 initlist_add_objects(obj->next, tail, list); 1500 1501 /* Recursively process the needed objects. */ 1502 if (obj->needed != NULL) 1503 initlist_add_neededs(obj->needed, list); 1504 1505 /* Add the object to the init list. */ 1506 if (obj->init != (Elf_Addr)NULL) 1507 objlist_push_tail(list, obj); 1508 1509 /* Add the object to the global fini list in the reverse order. */ 1510 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) { 1511 objlist_push_head(&list_fini, obj); 1512 obj->on_fini_list = true; 1513 } 1514 } 1515 1516 #ifndef FPTR_TARGET 1517 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1518 #endif 1519 1520 static void 1521 free_needed_filtees(Needed_Entry *n) 1522 { 1523 Needed_Entry *needed, *needed1; 1524 1525 for (needed = n; needed != NULL; needed = needed->next) { 1526 if (needed->obj != NULL) { 1527 dlclose(needed->obj); 1528 needed->obj = NULL; 1529 } 1530 } 1531 for (needed = n; needed != NULL; needed = needed1) { 1532 needed1 = needed->next; 1533 free(needed); 1534 } 1535 } 1536 1537 static void 1538 unload_filtees(Obj_Entry *obj) 1539 { 1540 1541 free_needed_filtees(obj->needed_filtees); 1542 obj->needed_filtees = NULL; 1543 free_needed_filtees(obj->needed_aux_filtees); 1544 obj->needed_aux_filtees = NULL; 1545 obj->filtees_loaded = false; 1546 } 1547 1548 static void 1549 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags) 1550 { 1551 1552 for (; needed != NULL; needed = needed->next) { 1553 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1554 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1555 RTLD_LOCAL); 1556 } 1557 } 1558 1559 static void 1560 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1561 { 1562 1563 lock_restart_for_upgrade(lockstate); 1564 if (!obj->filtees_loaded) { 1565 load_filtee1(obj, obj->needed_filtees, flags); 1566 load_filtee1(obj, obj->needed_aux_filtees, flags); 1567 obj->filtees_loaded = true; 1568 } 1569 } 1570 1571 static int 1572 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1573 { 1574 Obj_Entry *obj1; 1575 1576 for (; needed != NULL; needed = needed->next) { 1577 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1578 flags & ~RTLD_LO_NOLOAD); 1579 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1580 return (-1); 1581 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) { 1582 dbg("obj %s nodelete", obj1->path); 1583 init_dag(obj1); 1584 ref_dag(obj1); 1585 obj1->ref_nodel = true; 1586 } 1587 } 1588 return (0); 1589 } 1590 1591 /* 1592 * Given a shared object, traverse its list of needed objects, and load 1593 * each of them. Returns 0 on success. Generates an error message and 1594 * returns -1 on failure. 1595 */ 1596 static int 1597 load_needed_objects(Obj_Entry *first, int flags) 1598 { 1599 Obj_Entry *obj; 1600 1601 for (obj = first; obj != NULL; obj = obj->next) { 1602 if (process_needed(obj, obj->needed, flags) == -1) 1603 return (-1); 1604 } 1605 return (0); 1606 } 1607 1608 static int 1609 load_preload_objects(void) 1610 { 1611 char *p = ld_preload; 1612 static const char delim[] = " \t:;"; 1613 1614 if (p == NULL) 1615 return 0; 1616 1617 p += strspn(p, delim); 1618 while (*p != '\0') { 1619 size_t len = strcspn(p, delim); 1620 char savech; 1621 1622 savech = p[len]; 1623 p[len] = '\0'; 1624 if (load_object(p, -1, NULL, 0) == NULL) 1625 return -1; /* XXX - cleanup */ 1626 p[len] = savech; 1627 p += len; 1628 p += strspn(p, delim); 1629 } 1630 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 1631 return 0; 1632 } 1633 1634 static const char * 1635 printable_path(const char *path) 1636 { 1637 1638 return (path == NULL ? "<unknown>" : path); 1639 } 1640 1641 /* 1642 * Load a shared object into memory, if it is not already loaded. The 1643 * object may be specified by name or by user-supplied file descriptor 1644 * fd_u. In the later case, the fd_u descriptor is not closed, but its 1645 * duplicate is. 1646 * 1647 * Returns a pointer to the Obj_Entry for the object. Returns NULL 1648 * on failure. 1649 */ 1650 static Obj_Entry * 1651 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 1652 { 1653 Obj_Entry *obj; 1654 int fd; 1655 struct stat sb; 1656 char *path; 1657 1658 if (name != NULL) { 1659 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 1660 if (object_match_name(obj, name)) 1661 return (obj); 1662 } 1663 1664 path = find_library(name, refobj); 1665 if (path == NULL) 1666 return (NULL); 1667 } else 1668 path = NULL; 1669 1670 /* 1671 * If we didn't find a match by pathname, or the name is not 1672 * supplied, open the file and check again by device and inode. 1673 * This avoids false mismatches caused by multiple links or ".." 1674 * in pathnames. 1675 * 1676 * To avoid a race, we open the file and use fstat() rather than 1677 * using stat(). 1678 */ 1679 fd = -1; 1680 if (fd_u == -1) { 1681 if ((fd = open(path, O_RDONLY)) == -1) { 1682 _rtld_error("Cannot open \"%s\"", path); 1683 free(path); 1684 return (NULL); 1685 } 1686 } else { 1687 fd = dup(fd_u); 1688 if (fd == -1) { 1689 _rtld_error("Cannot dup fd"); 1690 free(path); 1691 return (NULL); 1692 } 1693 } 1694 if (fstat(fd, &sb) == -1) { 1695 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 1696 close(fd); 1697 free(path); 1698 return NULL; 1699 } 1700 for (obj = obj_list->next; obj != NULL; obj = obj->next) 1701 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 1702 break; 1703 if (obj != NULL && name != NULL) { 1704 object_add_name(obj, name); 1705 free(path); 1706 close(fd); 1707 return obj; 1708 } 1709 if (flags & RTLD_LO_NOLOAD) { 1710 free(path); 1711 close(fd); 1712 return (NULL); 1713 } 1714 1715 /* First use of this object, so we must map it in */ 1716 obj = do_load_object(fd, name, path, &sb, flags); 1717 if (obj == NULL) 1718 free(path); 1719 close(fd); 1720 1721 return obj; 1722 } 1723 1724 static Obj_Entry * 1725 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 1726 int flags) 1727 { 1728 Obj_Entry *obj; 1729 struct statfs fs; 1730 1731 /* 1732 * but first, make sure that environment variables haven't been 1733 * used to circumvent the noexec flag on a filesystem. 1734 */ 1735 if (dangerous_ld_env) { 1736 if (fstatfs(fd, &fs) != 0) { 1737 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 1738 return NULL; 1739 } 1740 if (fs.f_flags & MNT_NOEXEC) { 1741 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 1742 return NULL; 1743 } 1744 } 1745 dbg("loading \"%s\"", printable_path(path)); 1746 obj = map_object(fd, printable_path(path), sbp); 1747 if (obj == NULL) 1748 return NULL; 1749 1750 /* 1751 * If DT_SONAME is present in the object, digest_dynamic2 already 1752 * added it to the object names. 1753 */ 1754 if (name != NULL) 1755 object_add_name(obj, name); 1756 obj->path = path; 1757 digest_dynamic(obj, 0); 1758 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 1759 RTLD_LO_DLOPEN) { 1760 dbg("refusing to load non-loadable \"%s\"", obj->path); 1761 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 1762 munmap(obj->mapbase, obj->mapsize); 1763 obj_free(obj); 1764 return (NULL); 1765 } 1766 1767 *obj_tail = obj; 1768 obj_tail = &obj->next; 1769 obj_count++; 1770 obj_loads++; 1771 linkmap_add(obj); /* for GDB & dlinfo() */ 1772 max_stack_flags |= obj->stack_flags; 1773 1774 dbg(" %p .. %p: %s", obj->mapbase, 1775 obj->mapbase + obj->mapsize - 1, obj->path); 1776 if (obj->textrel) 1777 dbg(" WARNING: %s has impure text", obj->path); 1778 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 1779 obj->path); 1780 1781 return obj; 1782 } 1783 1784 static Obj_Entry * 1785 obj_from_addr(const void *addr) 1786 { 1787 Obj_Entry *obj; 1788 1789 for (obj = obj_list; obj != NULL; obj = obj->next) { 1790 if (addr < (void *) obj->mapbase) 1791 continue; 1792 if (addr < (void *) (obj->mapbase + obj->mapsize)) 1793 return obj; 1794 } 1795 return NULL; 1796 } 1797 1798 /* 1799 * Call the finalization functions for each of the objects in "list" 1800 * belonging to the DAG of "root" and referenced once. If NULL "root" 1801 * is specified, every finalization function will be called regardless 1802 * of the reference count and the list elements won't be freed. All of 1803 * the objects are expected to have non-NULL fini functions. 1804 */ 1805 static void 1806 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 1807 { 1808 Objlist_Entry *elm; 1809 char *saved_msg; 1810 1811 assert(root == NULL || root->refcount == 1); 1812 1813 /* 1814 * Preserve the current error message since a fini function might 1815 * call into the dynamic linker and overwrite it. 1816 */ 1817 saved_msg = errmsg_save(); 1818 do { 1819 STAILQ_FOREACH(elm, list, link) { 1820 if (root != NULL && (elm->obj->refcount != 1 || 1821 objlist_find(&root->dagmembers, elm->obj) == NULL)) 1822 continue; 1823 dbg("calling fini function for %s at %p", elm->obj->path, 1824 (void *)elm->obj->fini); 1825 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0, 1826 elm->obj->path); 1827 /* Remove object from fini list to prevent recursive invocation. */ 1828 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 1829 /* 1830 * XXX: If a dlopen() call references an object while the 1831 * fini function is in progress, we might end up trying to 1832 * unload the referenced object in dlclose() or the object 1833 * won't be unloaded although its fini function has been 1834 * called. 1835 */ 1836 lock_release(rtld_bind_lock, lockstate); 1837 call_initfini_pointer(elm->obj, elm->obj->fini); 1838 wlock_acquire(rtld_bind_lock, lockstate); 1839 /* No need to free anything if process is going down. */ 1840 if (root != NULL) 1841 free(elm); 1842 /* 1843 * We must restart the list traversal after every fini call 1844 * because a dlclose() call from the fini function or from 1845 * another thread might have modified the reference counts. 1846 */ 1847 break; 1848 } 1849 } while (elm != NULL); 1850 errmsg_restore(saved_msg); 1851 } 1852 1853 /* 1854 * Call the initialization functions for each of the objects in 1855 * "list". All of the objects are expected to have non-NULL init 1856 * functions. 1857 */ 1858 static void 1859 objlist_call_init(Objlist *list, RtldLockState *lockstate) 1860 { 1861 Objlist_Entry *elm; 1862 Obj_Entry *obj; 1863 char *saved_msg; 1864 1865 /* 1866 * Clean init_scanned flag so that objects can be rechecked and 1867 * possibly initialized earlier if any of vectors called below 1868 * cause the change by using dlopen. 1869 */ 1870 for (obj = obj_list; obj != NULL; obj = obj->next) 1871 obj->init_scanned = false; 1872 1873 /* 1874 * Preserve the current error message since an init function might 1875 * call into the dynamic linker and overwrite it. 1876 */ 1877 saved_msg = errmsg_save(); 1878 STAILQ_FOREACH(elm, list, link) { 1879 if (elm->obj->init_done) /* Initialized early. */ 1880 continue; 1881 dbg("calling init function for %s at %p", elm->obj->path, 1882 (void *)elm->obj->init); 1883 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0, 1884 elm->obj->path); 1885 /* 1886 * Race: other thread might try to use this object before current 1887 * one completes the initilization. Not much can be done here 1888 * without better locking. 1889 */ 1890 elm->obj->init_done = true; 1891 lock_release(rtld_bind_lock, lockstate); 1892 call_initfini_pointer(elm->obj, elm->obj->init); 1893 wlock_acquire(rtld_bind_lock, lockstate); 1894 } 1895 errmsg_restore(saved_msg); 1896 } 1897 1898 static void 1899 objlist_clear(Objlist *list) 1900 { 1901 Objlist_Entry *elm; 1902 1903 while (!STAILQ_EMPTY(list)) { 1904 elm = STAILQ_FIRST(list); 1905 STAILQ_REMOVE_HEAD(list, link); 1906 free(elm); 1907 } 1908 } 1909 1910 static Objlist_Entry * 1911 objlist_find(Objlist *list, const Obj_Entry *obj) 1912 { 1913 Objlist_Entry *elm; 1914 1915 STAILQ_FOREACH(elm, list, link) 1916 if (elm->obj == obj) 1917 return elm; 1918 return NULL; 1919 } 1920 1921 static void 1922 objlist_init(Objlist *list) 1923 { 1924 STAILQ_INIT(list); 1925 } 1926 1927 static void 1928 objlist_push_head(Objlist *list, Obj_Entry *obj) 1929 { 1930 Objlist_Entry *elm; 1931 1932 elm = NEW(Objlist_Entry); 1933 elm->obj = obj; 1934 STAILQ_INSERT_HEAD(list, elm, link); 1935 } 1936 1937 static void 1938 objlist_push_tail(Objlist *list, Obj_Entry *obj) 1939 { 1940 Objlist_Entry *elm; 1941 1942 elm = NEW(Objlist_Entry); 1943 elm->obj = obj; 1944 STAILQ_INSERT_TAIL(list, elm, link); 1945 } 1946 1947 static void 1948 objlist_remove(Objlist *list, Obj_Entry *obj) 1949 { 1950 Objlist_Entry *elm; 1951 1952 if ((elm = objlist_find(list, obj)) != NULL) { 1953 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 1954 free(elm); 1955 } 1956 } 1957 1958 /* 1959 * Relocate newly-loaded shared objects. The argument is a pointer to 1960 * the Obj_Entry for the first such object. All objects from the first 1961 * to the end of the list of objects are relocated. Returns 0 on success, 1962 * or -1 on failure. 1963 */ 1964 static int 1965 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 1966 RtldLockState *lockstate) 1967 { 1968 Obj_Entry *obj; 1969 1970 for (obj = first; obj != NULL; obj = obj->next) { 1971 if (obj != rtldobj) 1972 dbg("relocating \"%s\"", obj->path); 1973 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL || 1974 obj->symtab == NULL || obj->strtab == NULL) { 1975 _rtld_error("%s: Shared object has no run-time symbol table", 1976 obj->path); 1977 return -1; 1978 } 1979 1980 if (obj->textrel) { 1981 /* There are relocations to the write-protected text segment. */ 1982 if (mprotect(obj->mapbase, obj->textsize, 1983 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 1984 _rtld_error("%s: Cannot write-enable text segment: %s", 1985 obj->path, strerror(errno)); 1986 return -1; 1987 } 1988 } 1989 1990 /* Process the non-PLT relocations. */ 1991 if (reloc_non_plt(obj, rtldobj, lockstate)) 1992 return -1; 1993 1994 if (obj->textrel) { /* Re-protected the text segment. */ 1995 if (mprotect(obj->mapbase, obj->textsize, 1996 PROT_READ|PROT_EXEC) == -1) { 1997 _rtld_error("%s: Cannot write-protect text segment: %s", 1998 obj->path, strerror(errno)); 1999 return -1; 2000 } 2001 } 2002 2003 2004 /* Set the special PLT or GOT entries. */ 2005 init_pltgot(obj); 2006 2007 /* Process the PLT relocations. */ 2008 if (reloc_plt(obj) == -1) 2009 return -1; 2010 /* Relocate the jump slots if we are doing immediate binding. */ 2011 if (obj->bind_now || bind_now) 2012 if (reloc_jmpslots(obj, lockstate) == -1) 2013 return -1; 2014 2015 if (obj->relro_size > 0) { 2016 if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) { 2017 _rtld_error("%s: Cannot enforce relro protection: %s", 2018 obj->path, strerror(errno)); 2019 return -1; 2020 } 2021 } 2022 2023 /* 2024 * Set up the magic number and version in the Obj_Entry. These 2025 * were checked in the crt1.o from the original ElfKit, so we 2026 * set them for backward compatibility. 2027 */ 2028 obj->magic = RTLD_MAGIC; 2029 obj->version = RTLD_VERSION; 2030 } 2031 2032 return (0); 2033 } 2034 2035 /* 2036 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2037 * referencing STT_GNU_IFUNC symbols is postponed till the other 2038 * relocations are done. The indirect functions specified as 2039 * ifunc are allowed to call other symbols, so we need to have 2040 * objects relocated before asking for resolution from indirects. 2041 * 2042 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2043 * instead of the usual lazy handling of PLT slots. It is 2044 * consistent with how GNU does it. 2045 */ 2046 static int 2047 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, RtldLockState *lockstate) 2048 { 2049 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2050 return (-1); 2051 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2052 reloc_gnu_ifunc(obj, lockstate) == -1) 2053 return (-1); 2054 return (0); 2055 } 2056 2057 static int 2058 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, RtldLockState *lockstate) 2059 { 2060 Obj_Entry *obj; 2061 2062 for (obj = first; obj != NULL; obj = obj->next) { 2063 if (resolve_object_ifunc(obj, bind_now, lockstate) == -1) 2064 return (-1); 2065 } 2066 return (0); 2067 } 2068 2069 static int 2070 initlist_objects_ifunc(Objlist *list, bool bind_now, RtldLockState *lockstate) 2071 { 2072 Objlist_Entry *elm; 2073 2074 STAILQ_FOREACH(elm, list, link) { 2075 if (resolve_object_ifunc(elm->obj, bind_now, lockstate) == -1) 2076 return (-1); 2077 } 2078 return (0); 2079 } 2080 2081 /* 2082 * Cleanup procedure. It will be called (by the atexit mechanism) just 2083 * before the process exits. 2084 */ 2085 static void 2086 rtld_exit(void) 2087 { 2088 RtldLockState lockstate; 2089 2090 wlock_acquire(rtld_bind_lock, &lockstate); 2091 dbg("rtld_exit()"); 2092 objlist_call_fini(&list_fini, NULL, &lockstate); 2093 /* No need to remove the items from the list, since we are exiting. */ 2094 if (!libmap_disable) 2095 lm_fini(); 2096 lock_release(rtld_bind_lock, &lockstate); 2097 } 2098 2099 static void * 2100 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2101 { 2102 #ifdef COMPAT_32BIT 2103 const char *trans; 2104 #endif 2105 if (path == NULL) 2106 return (NULL); 2107 2108 path += strspn(path, ":;"); 2109 while (*path != '\0') { 2110 size_t len; 2111 char *res; 2112 2113 len = strcspn(path, ":;"); 2114 #ifdef COMPAT_32BIT 2115 trans = lm_findn(NULL, path, len); 2116 if (trans) 2117 res = callback(trans, strlen(trans), arg); 2118 else 2119 #endif 2120 res = callback(path, len, arg); 2121 2122 if (res != NULL) 2123 return (res); 2124 2125 path += len; 2126 path += strspn(path, ":;"); 2127 } 2128 2129 return (NULL); 2130 } 2131 2132 struct try_library_args { 2133 const char *name; 2134 size_t namelen; 2135 char *buffer; 2136 size_t buflen; 2137 }; 2138 2139 static void * 2140 try_library_path(const char *dir, size_t dirlen, void *param) 2141 { 2142 struct try_library_args *arg; 2143 2144 arg = param; 2145 if (*dir == '/' || trust) { 2146 char *pathname; 2147 2148 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2149 return (NULL); 2150 2151 pathname = arg->buffer; 2152 strncpy(pathname, dir, dirlen); 2153 pathname[dirlen] = '/'; 2154 strcpy(pathname + dirlen + 1, arg->name); 2155 2156 dbg(" Trying \"%s\"", pathname); 2157 if (access(pathname, F_OK) == 0) { /* We found it */ 2158 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2159 strcpy(pathname, arg->buffer); 2160 return (pathname); 2161 } 2162 } 2163 return (NULL); 2164 } 2165 2166 static char * 2167 search_library_path(const char *name, const char *path) 2168 { 2169 char *p; 2170 struct try_library_args arg; 2171 2172 if (path == NULL) 2173 return NULL; 2174 2175 arg.name = name; 2176 arg.namelen = strlen(name); 2177 arg.buffer = xmalloc(PATH_MAX); 2178 arg.buflen = PATH_MAX; 2179 2180 p = path_enumerate(path, try_library_path, &arg); 2181 2182 free(arg.buffer); 2183 2184 return (p); 2185 } 2186 2187 int 2188 dlclose(void *handle) 2189 { 2190 Obj_Entry *root; 2191 RtldLockState lockstate; 2192 2193 wlock_acquire(rtld_bind_lock, &lockstate); 2194 root = dlcheck(handle); 2195 if (root == NULL) { 2196 lock_release(rtld_bind_lock, &lockstate); 2197 return -1; 2198 } 2199 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2200 root->path); 2201 2202 /* Unreference the object and its dependencies. */ 2203 root->dl_refcount--; 2204 2205 if (root->refcount == 1) { 2206 /* 2207 * The object will be no longer referenced, so we must unload it. 2208 * First, call the fini functions. 2209 */ 2210 objlist_call_fini(&list_fini, root, &lockstate); 2211 2212 unref_dag(root); 2213 2214 /* Finish cleaning up the newly-unreferenced objects. */ 2215 GDB_STATE(RT_DELETE,&root->linkmap); 2216 unload_object(root); 2217 GDB_STATE(RT_CONSISTENT,NULL); 2218 } else 2219 unref_dag(root); 2220 2221 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2222 lock_release(rtld_bind_lock, &lockstate); 2223 return 0; 2224 } 2225 2226 char * 2227 dlerror(void) 2228 { 2229 char *msg = error_message; 2230 error_message = NULL; 2231 return msg; 2232 } 2233 2234 /* 2235 * This function is deprecated and has no effect. 2236 */ 2237 void 2238 dllockinit(void *context, 2239 void *(*lock_create)(void *context), 2240 void (*rlock_acquire)(void *lock), 2241 void (*wlock_acquire)(void *lock), 2242 void (*lock_release)(void *lock), 2243 void (*lock_destroy)(void *lock), 2244 void (*context_destroy)(void *context)) 2245 { 2246 static void *cur_context; 2247 static void (*cur_context_destroy)(void *); 2248 2249 /* Just destroy the context from the previous call, if necessary. */ 2250 if (cur_context_destroy != NULL) 2251 cur_context_destroy(cur_context); 2252 cur_context = context; 2253 cur_context_destroy = context_destroy; 2254 } 2255 2256 void * 2257 dlopen(const char *name, int mode) 2258 { 2259 2260 return (rtld_dlopen(name, -1, mode)); 2261 } 2262 2263 void * 2264 fdlopen(int fd, int mode) 2265 { 2266 2267 return (rtld_dlopen(NULL, fd, mode)); 2268 } 2269 2270 static void * 2271 rtld_dlopen(const char *name, int fd, int mode) 2272 { 2273 RtldLockState lockstate; 2274 int lo_flags; 2275 2276 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2277 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2278 if (ld_tracing != NULL) { 2279 rlock_acquire(rtld_bind_lock, &lockstate); 2280 if (sigsetjmp(lockstate.env, 0) != 0) 2281 lock_upgrade(rtld_bind_lock, &lockstate); 2282 environ = (char **)*get_program_var_addr("environ", &lockstate); 2283 lock_release(rtld_bind_lock, &lockstate); 2284 } 2285 lo_flags = RTLD_LO_DLOPEN; 2286 if (mode & RTLD_NODELETE) 2287 lo_flags |= RTLD_LO_NODELETE; 2288 if (mode & RTLD_NOLOAD) 2289 lo_flags |= RTLD_LO_NOLOAD; 2290 if (ld_tracing != NULL) 2291 lo_flags |= RTLD_LO_TRACE; 2292 2293 return (dlopen_object(name, fd, obj_main, lo_flags, 2294 mode & (RTLD_MODEMASK | RTLD_GLOBAL))); 2295 } 2296 2297 static void 2298 dlopen_cleanup(Obj_Entry *obj) 2299 { 2300 2301 obj->dl_refcount--; 2302 unref_dag(obj); 2303 if (obj->refcount == 0) 2304 unload_object(obj); 2305 } 2306 2307 static Obj_Entry * 2308 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2309 int mode) 2310 { 2311 Obj_Entry **old_obj_tail; 2312 Obj_Entry *obj; 2313 Objlist initlist; 2314 RtldLockState lockstate; 2315 int result; 2316 2317 objlist_init(&initlist); 2318 2319 wlock_acquire(rtld_bind_lock, &lockstate); 2320 GDB_STATE(RT_ADD,NULL); 2321 2322 old_obj_tail = obj_tail; 2323 obj = NULL; 2324 if (name == NULL && fd == -1) { 2325 obj = obj_main; 2326 obj->refcount++; 2327 } else { 2328 obj = load_object(name, fd, refobj, lo_flags); 2329 } 2330 2331 if (obj) { 2332 obj->dl_refcount++; 2333 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2334 objlist_push_tail(&list_global, obj); 2335 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2336 assert(*old_obj_tail == obj); 2337 result = load_needed_objects(obj, lo_flags & RTLD_LO_DLOPEN); 2338 init_dag(obj); 2339 ref_dag(obj); 2340 if (result != -1) 2341 result = rtld_verify_versions(&obj->dagmembers); 2342 if (result != -1 && ld_tracing) 2343 goto trace; 2344 if (result == -1 || (relocate_objects(obj, (mode & RTLD_MODEMASK) 2345 == RTLD_NOW, &obj_rtld, &lockstate)) == -1) { 2346 dlopen_cleanup(obj); 2347 obj = NULL; 2348 } else { 2349 /* Make list of init functions to call. */ 2350 initlist_add_objects(obj, &obj->next, &initlist); 2351 } 2352 } else { 2353 2354 /* 2355 * Bump the reference counts for objects on this DAG. If 2356 * this is the first dlopen() call for the object that was 2357 * already loaded as a dependency, initialize the dag 2358 * starting at it. 2359 */ 2360 init_dag(obj); 2361 ref_dag(obj); 2362 2363 if ((lo_flags & RTLD_LO_TRACE) != 0) 2364 goto trace; 2365 } 2366 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2367 obj->z_nodelete) && !obj->ref_nodel) { 2368 dbg("obj %s nodelete", obj->path); 2369 ref_dag(obj); 2370 obj->z_nodelete = obj->ref_nodel = true; 2371 } 2372 } 2373 2374 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2375 name); 2376 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2377 2378 map_stacks_exec(&lockstate); 2379 2380 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2381 &lockstate) == -1) { 2382 objlist_clear(&initlist); 2383 dlopen_cleanup(obj); 2384 lock_release(rtld_bind_lock, &lockstate); 2385 return (NULL); 2386 } 2387 2388 /* Call the init functions. */ 2389 objlist_call_init(&initlist, &lockstate); 2390 objlist_clear(&initlist); 2391 lock_release(rtld_bind_lock, &lockstate); 2392 return obj; 2393 trace: 2394 trace_loaded_objects(obj); 2395 lock_release(rtld_bind_lock, &lockstate); 2396 exit(0); 2397 } 2398 2399 static void * 2400 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2401 int flags) 2402 { 2403 DoneList donelist; 2404 const Obj_Entry *obj, *defobj; 2405 const Elf_Sym *def; 2406 SymLook req; 2407 RtldLockState lockstate; 2408 int res; 2409 2410 def = NULL; 2411 defobj = NULL; 2412 symlook_init(&req, name); 2413 req.ventry = ve; 2414 req.flags = flags | SYMLOOK_IN_PLT; 2415 req.lockstate = &lockstate; 2416 2417 rlock_acquire(rtld_bind_lock, &lockstate); 2418 if (sigsetjmp(lockstate.env, 0) != 0) 2419 lock_upgrade(rtld_bind_lock, &lockstate); 2420 if (handle == NULL || handle == RTLD_NEXT || 2421 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2422 2423 if ((obj = obj_from_addr(retaddr)) == NULL) { 2424 _rtld_error("Cannot determine caller's shared object"); 2425 lock_release(rtld_bind_lock, &lockstate); 2426 return NULL; 2427 } 2428 if (handle == NULL) { /* Just the caller's shared object. */ 2429 res = symlook_obj(&req, obj); 2430 if (res == 0) { 2431 def = req.sym_out; 2432 defobj = req.defobj_out; 2433 } 2434 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2435 handle == RTLD_SELF) { /* ... caller included */ 2436 if (handle == RTLD_NEXT) 2437 obj = obj->next; 2438 for (; obj != NULL; obj = obj->next) { 2439 res = symlook_obj(&req, obj); 2440 if (res == 0) { 2441 if (def == NULL || 2442 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2443 def = req.sym_out; 2444 defobj = req.defobj_out; 2445 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2446 break; 2447 } 2448 } 2449 } 2450 /* 2451 * Search the dynamic linker itself, and possibly resolve the 2452 * symbol from there. This is how the application links to 2453 * dynamic linker services such as dlopen. 2454 */ 2455 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2456 res = symlook_obj(&req, &obj_rtld); 2457 if (res == 0) { 2458 def = req.sym_out; 2459 defobj = req.defobj_out; 2460 } 2461 } 2462 } else { 2463 assert(handle == RTLD_DEFAULT); 2464 res = symlook_default(&req, obj); 2465 if (res == 0) { 2466 defobj = req.defobj_out; 2467 def = req.sym_out; 2468 } 2469 } 2470 } else { 2471 if ((obj = dlcheck(handle)) == NULL) { 2472 lock_release(rtld_bind_lock, &lockstate); 2473 return NULL; 2474 } 2475 2476 donelist_init(&donelist); 2477 if (obj->mainprog) { 2478 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 2479 res = symlook_global(&req, &donelist); 2480 if (res == 0) { 2481 def = req.sym_out; 2482 defobj = req.defobj_out; 2483 } 2484 /* 2485 * Search the dynamic linker itself, and possibly resolve the 2486 * symbol from there. This is how the application links to 2487 * dynamic linker services such as dlopen. 2488 */ 2489 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2490 res = symlook_obj(&req, &obj_rtld); 2491 if (res == 0) { 2492 def = req.sym_out; 2493 defobj = req.defobj_out; 2494 } 2495 } 2496 } 2497 else { 2498 /* Search the whole DAG rooted at the given object. */ 2499 res = symlook_list(&req, &obj->dagmembers, &donelist); 2500 if (res == 0) { 2501 def = req.sym_out; 2502 defobj = req.defobj_out; 2503 } 2504 } 2505 } 2506 2507 if (def != NULL) { 2508 lock_release(rtld_bind_lock, &lockstate); 2509 2510 /* 2511 * The value required by the caller is derived from the value 2512 * of the symbol. For the ia64 architecture, we need to 2513 * construct a function descriptor which the caller can use to 2514 * call the function with the right 'gp' value. For other 2515 * architectures and for non-functions, the value is simply 2516 * the relocated value of the symbol. 2517 */ 2518 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 2519 return (make_function_pointer(def, defobj)); 2520 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 2521 return (rtld_resolve_ifunc(defobj, def)); 2522 else 2523 return (defobj->relocbase + def->st_value); 2524 } 2525 2526 _rtld_error("Undefined symbol \"%s\"", name); 2527 lock_release(rtld_bind_lock, &lockstate); 2528 return NULL; 2529 } 2530 2531 void * 2532 dlsym(void *handle, const char *name) 2533 { 2534 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 2535 SYMLOOK_DLSYM); 2536 } 2537 2538 dlfunc_t 2539 dlfunc(void *handle, const char *name) 2540 { 2541 union { 2542 void *d; 2543 dlfunc_t f; 2544 } rv; 2545 2546 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 2547 SYMLOOK_DLSYM); 2548 return (rv.f); 2549 } 2550 2551 void * 2552 dlvsym(void *handle, const char *name, const char *version) 2553 { 2554 Ver_Entry ventry; 2555 2556 ventry.name = version; 2557 ventry.file = NULL; 2558 ventry.hash = elf_hash(version); 2559 ventry.flags= 0; 2560 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 2561 SYMLOOK_DLSYM); 2562 } 2563 2564 int 2565 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 2566 { 2567 const Obj_Entry *obj; 2568 RtldLockState lockstate; 2569 2570 rlock_acquire(rtld_bind_lock, &lockstate); 2571 obj = obj_from_addr(addr); 2572 if (obj == NULL) { 2573 _rtld_error("No shared object contains address"); 2574 lock_release(rtld_bind_lock, &lockstate); 2575 return (0); 2576 } 2577 rtld_fill_dl_phdr_info(obj, phdr_info); 2578 lock_release(rtld_bind_lock, &lockstate); 2579 return (1); 2580 } 2581 2582 int 2583 dladdr(const void *addr, Dl_info *info) 2584 { 2585 const Obj_Entry *obj; 2586 const Elf_Sym *def; 2587 void *symbol_addr; 2588 unsigned long symoffset; 2589 RtldLockState lockstate; 2590 2591 rlock_acquire(rtld_bind_lock, &lockstate); 2592 obj = obj_from_addr(addr); 2593 if (obj == NULL) { 2594 _rtld_error("No shared object contains address"); 2595 lock_release(rtld_bind_lock, &lockstate); 2596 return 0; 2597 } 2598 info->dli_fname = obj->path; 2599 info->dli_fbase = obj->mapbase; 2600 info->dli_saddr = (void *)0; 2601 info->dli_sname = NULL; 2602 2603 /* 2604 * Walk the symbol list looking for the symbol whose address is 2605 * closest to the address sent in. 2606 */ 2607 for (symoffset = 0; symoffset < obj->nchains; symoffset++) { 2608 def = obj->symtab + symoffset; 2609 2610 /* 2611 * For skip the symbol if st_shndx is either SHN_UNDEF or 2612 * SHN_COMMON. 2613 */ 2614 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 2615 continue; 2616 2617 /* 2618 * If the symbol is greater than the specified address, or if it 2619 * is further away from addr than the current nearest symbol, 2620 * then reject it. 2621 */ 2622 symbol_addr = obj->relocbase + def->st_value; 2623 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 2624 continue; 2625 2626 /* Update our idea of the nearest symbol. */ 2627 info->dli_sname = obj->strtab + def->st_name; 2628 info->dli_saddr = symbol_addr; 2629 2630 /* Exact match? */ 2631 if (info->dli_saddr == addr) 2632 break; 2633 } 2634 lock_release(rtld_bind_lock, &lockstate); 2635 return 1; 2636 } 2637 2638 int 2639 dlinfo(void *handle, int request, void *p) 2640 { 2641 const Obj_Entry *obj; 2642 RtldLockState lockstate; 2643 int error; 2644 2645 rlock_acquire(rtld_bind_lock, &lockstate); 2646 2647 if (handle == NULL || handle == RTLD_SELF) { 2648 void *retaddr; 2649 2650 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 2651 if ((obj = obj_from_addr(retaddr)) == NULL) 2652 _rtld_error("Cannot determine caller's shared object"); 2653 } else 2654 obj = dlcheck(handle); 2655 2656 if (obj == NULL) { 2657 lock_release(rtld_bind_lock, &lockstate); 2658 return (-1); 2659 } 2660 2661 error = 0; 2662 switch (request) { 2663 case RTLD_DI_LINKMAP: 2664 *((struct link_map const **)p) = &obj->linkmap; 2665 break; 2666 case RTLD_DI_ORIGIN: 2667 error = rtld_dirname(obj->path, p); 2668 break; 2669 2670 case RTLD_DI_SERINFOSIZE: 2671 case RTLD_DI_SERINFO: 2672 error = do_search_info(obj, request, (struct dl_serinfo *)p); 2673 break; 2674 2675 default: 2676 _rtld_error("Invalid request %d passed to dlinfo()", request); 2677 error = -1; 2678 } 2679 2680 lock_release(rtld_bind_lock, &lockstate); 2681 2682 return (error); 2683 } 2684 2685 static void 2686 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 2687 { 2688 2689 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 2690 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 2691 STAILQ_FIRST(&obj->names)->name : obj->path; 2692 phdr_info->dlpi_phdr = obj->phdr; 2693 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 2694 phdr_info->dlpi_tls_modid = obj->tlsindex; 2695 phdr_info->dlpi_tls_data = obj->tlsinit; 2696 phdr_info->dlpi_adds = obj_loads; 2697 phdr_info->dlpi_subs = obj_loads - obj_count; 2698 } 2699 2700 int 2701 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 2702 { 2703 struct dl_phdr_info phdr_info; 2704 const Obj_Entry *obj; 2705 RtldLockState bind_lockstate, phdr_lockstate; 2706 int error; 2707 2708 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 2709 rlock_acquire(rtld_bind_lock, &bind_lockstate); 2710 2711 error = 0; 2712 2713 for (obj = obj_list; obj != NULL; obj = obj->next) { 2714 rtld_fill_dl_phdr_info(obj, &phdr_info); 2715 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 2716 break; 2717 2718 } 2719 lock_release(rtld_bind_lock, &bind_lockstate); 2720 lock_release(rtld_phdr_lock, &phdr_lockstate); 2721 2722 return (error); 2723 } 2724 2725 struct fill_search_info_args { 2726 int request; 2727 unsigned int flags; 2728 Dl_serinfo *serinfo; 2729 Dl_serpath *serpath; 2730 char *strspace; 2731 }; 2732 2733 static void * 2734 fill_search_info(const char *dir, size_t dirlen, void *param) 2735 { 2736 struct fill_search_info_args *arg; 2737 2738 arg = param; 2739 2740 if (arg->request == RTLD_DI_SERINFOSIZE) { 2741 arg->serinfo->dls_cnt ++; 2742 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1; 2743 } else { 2744 struct dl_serpath *s_entry; 2745 2746 s_entry = arg->serpath; 2747 s_entry->dls_name = arg->strspace; 2748 s_entry->dls_flags = arg->flags; 2749 2750 strncpy(arg->strspace, dir, dirlen); 2751 arg->strspace[dirlen] = '\0'; 2752 2753 arg->strspace += dirlen + 1; 2754 arg->serpath++; 2755 } 2756 2757 return (NULL); 2758 } 2759 2760 static int 2761 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 2762 { 2763 struct dl_serinfo _info; 2764 struct fill_search_info_args args; 2765 2766 args.request = RTLD_DI_SERINFOSIZE; 2767 args.serinfo = &_info; 2768 2769 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2770 _info.dls_cnt = 0; 2771 2772 path_enumerate(ld_library_path, fill_search_info, &args); 2773 path_enumerate(obj->rpath, fill_search_info, &args); 2774 path_enumerate(gethints(), fill_search_info, &args); 2775 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 2776 2777 2778 if (request == RTLD_DI_SERINFOSIZE) { 2779 info->dls_size = _info.dls_size; 2780 info->dls_cnt = _info.dls_cnt; 2781 return (0); 2782 } 2783 2784 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 2785 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 2786 return (-1); 2787 } 2788 2789 args.request = RTLD_DI_SERINFO; 2790 args.serinfo = info; 2791 args.serpath = &info->dls_serpath[0]; 2792 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 2793 2794 args.flags = LA_SER_LIBPATH; 2795 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 2796 return (-1); 2797 2798 args.flags = LA_SER_RUNPATH; 2799 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 2800 return (-1); 2801 2802 args.flags = LA_SER_CONFIG; 2803 if (path_enumerate(gethints(), fill_search_info, &args) != NULL) 2804 return (-1); 2805 2806 args.flags = LA_SER_DEFAULT; 2807 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 2808 return (-1); 2809 return (0); 2810 } 2811 2812 static int 2813 rtld_dirname(const char *path, char *bname) 2814 { 2815 const char *endp; 2816 2817 /* Empty or NULL string gets treated as "." */ 2818 if (path == NULL || *path == '\0') { 2819 bname[0] = '.'; 2820 bname[1] = '\0'; 2821 return (0); 2822 } 2823 2824 /* Strip trailing slashes */ 2825 endp = path + strlen(path) - 1; 2826 while (endp > path && *endp == '/') 2827 endp--; 2828 2829 /* Find the start of the dir */ 2830 while (endp > path && *endp != '/') 2831 endp--; 2832 2833 /* Either the dir is "/" or there are no slashes */ 2834 if (endp == path) { 2835 bname[0] = *endp == '/' ? '/' : '.'; 2836 bname[1] = '\0'; 2837 return (0); 2838 } else { 2839 do { 2840 endp--; 2841 } while (endp > path && *endp == '/'); 2842 } 2843 2844 if (endp - path + 2 > PATH_MAX) 2845 { 2846 _rtld_error("Filename is too long: %s", path); 2847 return(-1); 2848 } 2849 2850 strncpy(bname, path, endp - path + 1); 2851 bname[endp - path + 1] = '\0'; 2852 return (0); 2853 } 2854 2855 static int 2856 rtld_dirname_abs(const char *path, char *base) 2857 { 2858 char base_rel[PATH_MAX]; 2859 2860 if (rtld_dirname(path, base) == -1) 2861 return (-1); 2862 if (base[0] == '/') 2863 return (0); 2864 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 2865 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 2866 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 2867 return (-1); 2868 strcpy(base, base_rel); 2869 return (0); 2870 } 2871 2872 static void 2873 linkmap_add(Obj_Entry *obj) 2874 { 2875 struct link_map *l = &obj->linkmap; 2876 struct link_map *prev; 2877 2878 obj->linkmap.l_name = obj->path; 2879 obj->linkmap.l_addr = obj->mapbase; 2880 obj->linkmap.l_ld = obj->dynamic; 2881 #ifdef __mips__ 2882 /* GDB needs load offset on MIPS to use the symbols */ 2883 obj->linkmap.l_offs = obj->relocbase; 2884 #endif 2885 2886 if (r_debug.r_map == NULL) { 2887 r_debug.r_map = l; 2888 return; 2889 } 2890 2891 /* 2892 * Scan to the end of the list, but not past the entry for the 2893 * dynamic linker, which we want to keep at the very end. 2894 */ 2895 for (prev = r_debug.r_map; 2896 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 2897 prev = prev->l_next) 2898 ; 2899 2900 /* Link in the new entry. */ 2901 l->l_prev = prev; 2902 l->l_next = prev->l_next; 2903 if (l->l_next != NULL) 2904 l->l_next->l_prev = l; 2905 prev->l_next = l; 2906 } 2907 2908 static void 2909 linkmap_delete(Obj_Entry *obj) 2910 { 2911 struct link_map *l = &obj->linkmap; 2912 2913 if (l->l_prev == NULL) { 2914 if ((r_debug.r_map = l->l_next) != NULL) 2915 l->l_next->l_prev = NULL; 2916 return; 2917 } 2918 2919 if ((l->l_prev->l_next = l->l_next) != NULL) 2920 l->l_next->l_prev = l->l_prev; 2921 } 2922 2923 /* 2924 * Function for the debugger to set a breakpoint on to gain control. 2925 * 2926 * The two parameters allow the debugger to easily find and determine 2927 * what the runtime loader is doing and to whom it is doing it. 2928 * 2929 * When the loadhook trap is hit (r_debug_state, set at program 2930 * initialization), the arguments can be found on the stack: 2931 * 2932 * +8 struct link_map *m 2933 * +4 struct r_debug *rd 2934 * +0 RetAddr 2935 */ 2936 void 2937 r_debug_state(struct r_debug* rd, struct link_map *m) 2938 { 2939 /* 2940 * The following is a hack to force the compiler to emit calls to 2941 * this function, even when optimizing. If the function is empty, 2942 * the compiler is not obliged to emit any code for calls to it, 2943 * even when marked __noinline. However, gdb depends on those 2944 * calls being made. 2945 */ 2946 __asm __volatile("" : : : "memory"); 2947 } 2948 2949 /* 2950 * Get address of the pointer variable in the main program. 2951 * Prefer non-weak symbol over the weak one. 2952 */ 2953 static const void ** 2954 get_program_var_addr(const char *name, RtldLockState *lockstate) 2955 { 2956 SymLook req; 2957 DoneList donelist; 2958 2959 symlook_init(&req, name); 2960 req.lockstate = lockstate; 2961 donelist_init(&donelist); 2962 if (symlook_global(&req, &donelist) != 0) 2963 return (NULL); 2964 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 2965 return ((const void **)make_function_pointer(req.sym_out, 2966 req.defobj_out)); 2967 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 2968 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 2969 else 2970 return ((const void **)(req.defobj_out->relocbase + 2971 req.sym_out->st_value)); 2972 } 2973 2974 /* 2975 * Set a pointer variable in the main program to the given value. This 2976 * is used to set key variables such as "environ" before any of the 2977 * init functions are called. 2978 */ 2979 static void 2980 set_program_var(const char *name, const void *value) 2981 { 2982 const void **addr; 2983 2984 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 2985 dbg("\"%s\": *%p <-- %p", name, addr, value); 2986 *addr = value; 2987 } 2988 } 2989 2990 /* 2991 * Search the global objects, including dependencies and main object, 2992 * for the given symbol. 2993 */ 2994 static int 2995 symlook_global(SymLook *req, DoneList *donelist) 2996 { 2997 SymLook req1; 2998 const Objlist_Entry *elm; 2999 int res; 3000 3001 symlook_init_from_req(&req1, req); 3002 3003 /* Search all objects loaded at program start up. */ 3004 if (req->defobj_out == NULL || 3005 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3006 res = symlook_list(&req1, &list_main, donelist); 3007 if (res == 0 && (req->defobj_out == NULL || 3008 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3009 req->sym_out = req1.sym_out; 3010 req->defobj_out = req1.defobj_out; 3011 assert(req->defobj_out != NULL); 3012 } 3013 } 3014 3015 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3016 STAILQ_FOREACH(elm, &list_global, link) { 3017 if (req->defobj_out != NULL && 3018 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3019 break; 3020 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3021 if (res == 0 && (req->defobj_out == NULL || 3022 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3023 req->sym_out = req1.sym_out; 3024 req->defobj_out = req1.defobj_out; 3025 assert(req->defobj_out != NULL); 3026 } 3027 } 3028 3029 return (req->sym_out != NULL ? 0 : ESRCH); 3030 } 3031 3032 /* 3033 * Given a symbol name in a referencing object, find the corresponding 3034 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3035 * no definition was found. Returns a pointer to the Obj_Entry of the 3036 * defining object via the reference parameter DEFOBJ_OUT. 3037 */ 3038 static int 3039 symlook_default(SymLook *req, const Obj_Entry *refobj) 3040 { 3041 DoneList donelist; 3042 const Objlist_Entry *elm; 3043 SymLook req1; 3044 int res; 3045 3046 donelist_init(&donelist); 3047 symlook_init_from_req(&req1, req); 3048 3049 /* Look first in the referencing object if linked symbolically. */ 3050 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3051 res = symlook_obj(&req1, refobj); 3052 if (res == 0) { 3053 req->sym_out = req1.sym_out; 3054 req->defobj_out = req1.defobj_out; 3055 assert(req->defobj_out != NULL); 3056 } 3057 } 3058 3059 symlook_global(req, &donelist); 3060 3061 /* Search all dlopened DAGs containing the referencing object. */ 3062 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3063 if (req->sym_out != NULL && 3064 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3065 break; 3066 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3067 if (res == 0 && (req->sym_out == NULL || 3068 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3069 req->sym_out = req1.sym_out; 3070 req->defobj_out = req1.defobj_out; 3071 assert(req->defobj_out != NULL); 3072 } 3073 } 3074 3075 /* 3076 * Search the dynamic linker itself, and possibly resolve the 3077 * symbol from there. This is how the application links to 3078 * dynamic linker services such as dlopen. 3079 */ 3080 if (req->sym_out == NULL || 3081 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3082 res = symlook_obj(&req1, &obj_rtld); 3083 if (res == 0) { 3084 req->sym_out = req1.sym_out; 3085 req->defobj_out = req1.defobj_out; 3086 assert(req->defobj_out != NULL); 3087 } 3088 } 3089 3090 return (req->sym_out != NULL ? 0 : ESRCH); 3091 } 3092 3093 static int 3094 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3095 { 3096 const Elf_Sym *def; 3097 const Obj_Entry *defobj; 3098 const Objlist_Entry *elm; 3099 SymLook req1; 3100 int res; 3101 3102 def = NULL; 3103 defobj = NULL; 3104 STAILQ_FOREACH(elm, objlist, link) { 3105 if (donelist_check(dlp, elm->obj)) 3106 continue; 3107 symlook_init_from_req(&req1, req); 3108 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3109 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3110 def = req1.sym_out; 3111 defobj = req1.defobj_out; 3112 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3113 break; 3114 } 3115 } 3116 } 3117 if (def != NULL) { 3118 req->sym_out = def; 3119 req->defobj_out = defobj; 3120 return (0); 3121 } 3122 return (ESRCH); 3123 } 3124 3125 /* 3126 * Search the chain of DAGS cointed to by the given Needed_Entry 3127 * for a symbol of the given name. Each DAG is scanned completely 3128 * before advancing to the next one. Returns a pointer to the symbol, 3129 * or NULL if no definition was found. 3130 */ 3131 static int 3132 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3133 { 3134 const Elf_Sym *def; 3135 const Needed_Entry *n; 3136 const Obj_Entry *defobj; 3137 SymLook req1; 3138 int res; 3139 3140 def = NULL; 3141 defobj = NULL; 3142 symlook_init_from_req(&req1, req); 3143 for (n = needed; n != NULL; n = n->next) { 3144 if (n->obj == NULL || 3145 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3146 continue; 3147 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3148 def = req1.sym_out; 3149 defobj = req1.defobj_out; 3150 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3151 break; 3152 } 3153 } 3154 if (def != NULL) { 3155 req->sym_out = def; 3156 req->defobj_out = defobj; 3157 return (0); 3158 } 3159 return (ESRCH); 3160 } 3161 3162 /* 3163 * Search the symbol table of a single shared object for a symbol of 3164 * the given name and version, if requested. Returns a pointer to the 3165 * symbol, or NULL if no definition was found. If the object is 3166 * filter, return filtered symbol from filtee. 3167 * 3168 * The symbol's hash value is passed in for efficiency reasons; that 3169 * eliminates many recomputations of the hash value. 3170 */ 3171 int 3172 symlook_obj(SymLook *req, const Obj_Entry *obj) 3173 { 3174 DoneList donelist; 3175 SymLook req1; 3176 int res, mres; 3177 3178 mres = symlook_obj1(req, obj); 3179 if (mres == 0) { 3180 if (obj->needed_filtees != NULL) { 3181 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate); 3182 donelist_init(&donelist); 3183 symlook_init_from_req(&req1, req); 3184 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3185 if (res == 0) { 3186 req->sym_out = req1.sym_out; 3187 req->defobj_out = req1.defobj_out; 3188 } 3189 return (res); 3190 } 3191 if (obj->needed_aux_filtees != NULL) { 3192 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate); 3193 donelist_init(&donelist); 3194 symlook_init_from_req(&req1, req); 3195 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3196 if (res == 0) { 3197 req->sym_out = req1.sym_out; 3198 req->defobj_out = req1.defobj_out; 3199 return (res); 3200 } 3201 } 3202 } 3203 return (mres); 3204 } 3205 3206 static int 3207 symlook_obj1(SymLook *req, const Obj_Entry *obj) 3208 { 3209 unsigned long symnum; 3210 const Elf_Sym *vsymp; 3211 Elf_Versym verndx; 3212 int vcount; 3213 3214 if (obj->buckets == NULL) 3215 return (ESRCH); 3216 3217 vsymp = NULL; 3218 vcount = 0; 3219 symnum = obj->buckets[req->hash % obj->nbuckets]; 3220 3221 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3222 const Elf_Sym *symp; 3223 const char *strp; 3224 3225 if (symnum >= obj->nchains) 3226 return (ESRCH); /* Bad object */ 3227 3228 symp = obj->symtab + symnum; 3229 strp = obj->strtab + symp->st_name; 3230 3231 switch (ELF_ST_TYPE(symp->st_info)) { 3232 case STT_FUNC: 3233 case STT_NOTYPE: 3234 case STT_OBJECT: 3235 case STT_GNU_IFUNC: 3236 if (symp->st_value == 0) 3237 continue; 3238 /* fallthrough */ 3239 case STT_TLS: 3240 if (symp->st_shndx != SHN_UNDEF) 3241 break; 3242 #ifndef __mips__ 3243 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3244 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3245 break; 3246 /* fallthrough */ 3247 #endif 3248 default: 3249 continue; 3250 } 3251 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3252 continue; 3253 3254 if (req->ventry == NULL) { 3255 if (obj->versyms != NULL) { 3256 verndx = VER_NDX(obj->versyms[symnum]); 3257 if (verndx > obj->vernum) { 3258 _rtld_error("%s: symbol %s references wrong version %d", 3259 obj->path, obj->strtab + symnum, verndx); 3260 continue; 3261 } 3262 /* 3263 * If we are not called from dlsym (i.e. this is a normal 3264 * relocation from unversioned binary), accept the symbol 3265 * immediately if it happens to have first version after 3266 * this shared object became versioned. Otherwise, if 3267 * symbol is versioned and not hidden, remember it. If it 3268 * is the only symbol with this name exported by the 3269 * shared object, it will be returned as a match at the 3270 * end of the function. If symbol is global (verndx < 2) 3271 * accept it unconditionally. 3272 */ 3273 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3274 verndx == VER_NDX_GIVEN) { 3275 req->sym_out = symp; 3276 req->defobj_out = obj; 3277 return (0); 3278 } 3279 else if (verndx >= VER_NDX_GIVEN) { 3280 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) { 3281 if (vsymp == NULL) 3282 vsymp = symp; 3283 vcount ++; 3284 } 3285 continue; 3286 } 3287 } 3288 req->sym_out = symp; 3289 req->defobj_out = obj; 3290 return (0); 3291 } else { 3292 if (obj->versyms == NULL) { 3293 if (object_match_name(obj, req->ventry->name)) { 3294 _rtld_error("%s: object %s should provide version %s for " 3295 "symbol %s", obj_rtld.path, obj->path, 3296 req->ventry->name, obj->strtab + symnum); 3297 continue; 3298 } 3299 } else { 3300 verndx = VER_NDX(obj->versyms[symnum]); 3301 if (verndx > obj->vernum) { 3302 _rtld_error("%s: symbol %s references wrong version %d", 3303 obj->path, obj->strtab + symnum, verndx); 3304 continue; 3305 } 3306 if (obj->vertab[verndx].hash != req->ventry->hash || 3307 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3308 /* 3309 * Version does not match. Look if this is a global symbol 3310 * and if it is not hidden. If global symbol (verndx < 2) 3311 * is available, use it. Do not return symbol if we are 3312 * called by dlvsym, because dlvsym looks for a specific 3313 * version and default one is not what dlvsym wants. 3314 */ 3315 if ((req->flags & SYMLOOK_DLSYM) || 3316 (obj->versyms[symnum] & VER_NDX_HIDDEN) || 3317 (verndx >= VER_NDX_GIVEN)) 3318 continue; 3319 } 3320 } 3321 req->sym_out = symp; 3322 req->defobj_out = obj; 3323 return (0); 3324 } 3325 } 3326 if (vcount == 1) { 3327 req->sym_out = vsymp; 3328 req->defobj_out = obj; 3329 return (0); 3330 } 3331 return (ESRCH); 3332 } 3333 3334 static void 3335 trace_loaded_objects(Obj_Entry *obj) 3336 { 3337 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3338 int c; 3339 3340 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3341 main_local = ""; 3342 3343 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3344 fmt1 = "\t%o => %p (%x)\n"; 3345 3346 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3347 fmt2 = "\t%o (%x)\n"; 3348 3349 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3350 3351 for (; obj; obj = obj->next) { 3352 Needed_Entry *needed; 3353 char *name, *path; 3354 bool is_lib; 3355 3356 if (list_containers && obj->needed != NULL) 3357 rtld_printf("%s:\n", obj->path); 3358 for (needed = obj->needed; needed; needed = needed->next) { 3359 if (needed->obj != NULL) { 3360 if (needed->obj->traced && !list_containers) 3361 continue; 3362 needed->obj->traced = true; 3363 path = needed->obj->path; 3364 } else 3365 path = "not found"; 3366 3367 name = (char *)obj->strtab + needed->name; 3368 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 3369 3370 fmt = is_lib ? fmt1 : fmt2; 3371 while ((c = *fmt++) != '\0') { 3372 switch (c) { 3373 default: 3374 rtld_putchar(c); 3375 continue; 3376 case '\\': 3377 switch (c = *fmt) { 3378 case '\0': 3379 continue; 3380 case 'n': 3381 rtld_putchar('\n'); 3382 break; 3383 case 't': 3384 rtld_putchar('\t'); 3385 break; 3386 } 3387 break; 3388 case '%': 3389 switch (c = *fmt) { 3390 case '\0': 3391 continue; 3392 case '%': 3393 default: 3394 rtld_putchar(c); 3395 break; 3396 case 'A': 3397 rtld_putstr(main_local); 3398 break; 3399 case 'a': 3400 rtld_putstr(obj_main->path); 3401 break; 3402 case 'o': 3403 rtld_putstr(name); 3404 break; 3405 #if 0 3406 case 'm': 3407 rtld_printf("%d", sodp->sod_major); 3408 break; 3409 case 'n': 3410 rtld_printf("%d", sodp->sod_minor); 3411 break; 3412 #endif 3413 case 'p': 3414 rtld_putstr(path); 3415 break; 3416 case 'x': 3417 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 3418 0); 3419 break; 3420 } 3421 break; 3422 } 3423 ++fmt; 3424 } 3425 } 3426 } 3427 } 3428 3429 /* 3430 * Unload a dlopened object and its dependencies from memory and from 3431 * our data structures. It is assumed that the DAG rooted in the 3432 * object has already been unreferenced, and that the object has a 3433 * reference count of 0. 3434 */ 3435 static void 3436 unload_object(Obj_Entry *root) 3437 { 3438 Obj_Entry *obj; 3439 Obj_Entry **linkp; 3440 3441 assert(root->refcount == 0); 3442 3443 /* 3444 * Pass over the DAG removing unreferenced objects from 3445 * appropriate lists. 3446 */ 3447 unlink_object(root); 3448 3449 /* Unmap all objects that are no longer referenced. */ 3450 linkp = &obj_list->next; 3451 while ((obj = *linkp) != NULL) { 3452 if (obj->refcount == 0) { 3453 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3454 obj->path); 3455 dbg("unloading \"%s\"", obj->path); 3456 unload_filtees(root); 3457 munmap(obj->mapbase, obj->mapsize); 3458 linkmap_delete(obj); 3459 *linkp = obj->next; 3460 obj_count--; 3461 obj_free(obj); 3462 } else 3463 linkp = &obj->next; 3464 } 3465 obj_tail = linkp; 3466 } 3467 3468 static void 3469 unlink_object(Obj_Entry *root) 3470 { 3471 Objlist_Entry *elm; 3472 3473 if (root->refcount == 0) { 3474 /* Remove the object from the RTLD_GLOBAL list. */ 3475 objlist_remove(&list_global, root); 3476 3477 /* Remove the object from all objects' DAG lists. */ 3478 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3479 objlist_remove(&elm->obj->dldags, root); 3480 if (elm->obj != root) 3481 unlink_object(elm->obj); 3482 } 3483 } 3484 } 3485 3486 static void 3487 ref_dag(Obj_Entry *root) 3488 { 3489 Objlist_Entry *elm; 3490 3491 assert(root->dag_inited); 3492 STAILQ_FOREACH(elm, &root->dagmembers, link) 3493 elm->obj->refcount++; 3494 } 3495 3496 static void 3497 unref_dag(Obj_Entry *root) 3498 { 3499 Objlist_Entry *elm; 3500 3501 assert(root->dag_inited); 3502 STAILQ_FOREACH(elm, &root->dagmembers, link) 3503 elm->obj->refcount--; 3504 } 3505 3506 /* 3507 * Common code for MD __tls_get_addr(). 3508 */ 3509 void * 3510 tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset) 3511 { 3512 Elf_Addr* dtv = *dtvp; 3513 RtldLockState lockstate; 3514 3515 /* Check dtv generation in case new modules have arrived */ 3516 if (dtv[0] != tls_dtv_generation) { 3517 Elf_Addr* newdtv; 3518 int to_copy; 3519 3520 wlock_acquire(rtld_bind_lock, &lockstate); 3521 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); 3522 to_copy = dtv[1]; 3523 if (to_copy > tls_max_index) 3524 to_copy = tls_max_index; 3525 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 3526 newdtv[0] = tls_dtv_generation; 3527 newdtv[1] = tls_max_index; 3528 free(dtv); 3529 lock_release(rtld_bind_lock, &lockstate); 3530 dtv = *dtvp = newdtv; 3531 } 3532 3533 /* Dynamically allocate module TLS if necessary */ 3534 if (!dtv[index + 1]) { 3535 /* Signal safe, wlock will block out signals. */ 3536 wlock_acquire(rtld_bind_lock, &lockstate); 3537 if (!dtv[index + 1]) 3538 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 3539 lock_release(rtld_bind_lock, &lockstate); 3540 } 3541 return (void*) (dtv[index + 1] + offset); 3542 } 3543 3544 /* XXX not sure what variants to use for arm. */ 3545 3546 #if defined(__ia64__) || defined(__powerpc__) 3547 3548 /* 3549 * Allocate Static TLS using the Variant I method. 3550 */ 3551 void * 3552 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 3553 { 3554 Obj_Entry *obj; 3555 char *tcb; 3556 Elf_Addr **tls; 3557 Elf_Addr *dtv; 3558 Elf_Addr addr; 3559 int i; 3560 3561 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 3562 return (oldtcb); 3563 3564 assert(tcbsize >= TLS_TCB_SIZE); 3565 tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 3566 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 3567 3568 if (oldtcb != NULL) { 3569 memcpy(tls, oldtcb, tls_static_space); 3570 free(oldtcb); 3571 3572 /* Adjust the DTV. */ 3573 dtv = tls[0]; 3574 for (i = 0; i < dtv[1]; i++) { 3575 if (dtv[i+2] >= (Elf_Addr)oldtcb && 3576 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 3577 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 3578 } 3579 } 3580 } else { 3581 dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr)); 3582 tls[0] = dtv; 3583 dtv[0] = tls_dtv_generation; 3584 dtv[1] = tls_max_index; 3585 3586 for (obj = objs; obj; obj = obj->next) { 3587 if (obj->tlsoffset > 0) { 3588 addr = (Elf_Addr)tls + obj->tlsoffset; 3589 if (obj->tlsinitsize > 0) 3590 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 3591 if (obj->tlssize > obj->tlsinitsize) 3592 memset((void*) (addr + obj->tlsinitsize), 0, 3593 obj->tlssize - obj->tlsinitsize); 3594 dtv[obj->tlsindex + 1] = addr; 3595 } 3596 } 3597 } 3598 3599 return (tcb); 3600 } 3601 3602 void 3603 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 3604 { 3605 Elf_Addr *dtv; 3606 Elf_Addr tlsstart, tlsend; 3607 int dtvsize, i; 3608 3609 assert(tcbsize >= TLS_TCB_SIZE); 3610 3611 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 3612 tlsend = tlsstart + tls_static_space; 3613 3614 dtv = *(Elf_Addr **)tlsstart; 3615 dtvsize = dtv[1]; 3616 for (i = 0; i < dtvsize; i++) { 3617 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 3618 free((void*)dtv[i+2]); 3619 } 3620 } 3621 free(dtv); 3622 free(tcb); 3623 } 3624 3625 #endif 3626 3627 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \ 3628 defined(__arm__) || defined(__mips__) 3629 3630 /* 3631 * Allocate Static TLS using the Variant II method. 3632 */ 3633 void * 3634 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 3635 { 3636 Obj_Entry *obj; 3637 size_t size; 3638 char *tls; 3639 Elf_Addr *dtv, *olddtv; 3640 Elf_Addr segbase, oldsegbase, addr; 3641 int i; 3642 3643 size = round(tls_static_space, tcbalign); 3644 3645 assert(tcbsize >= 2*sizeof(Elf_Addr)); 3646 tls = calloc(1, size + tcbsize); 3647 dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); 3648 3649 segbase = (Elf_Addr)(tls + size); 3650 ((Elf_Addr*)segbase)[0] = segbase; 3651 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 3652 3653 dtv[0] = tls_dtv_generation; 3654 dtv[1] = tls_max_index; 3655 3656 if (oldtls) { 3657 /* 3658 * Copy the static TLS block over whole. 3659 */ 3660 oldsegbase = (Elf_Addr) oldtls; 3661 memcpy((void *)(segbase - tls_static_space), 3662 (const void *)(oldsegbase - tls_static_space), 3663 tls_static_space); 3664 3665 /* 3666 * If any dynamic TLS blocks have been created tls_get_addr(), 3667 * move them over. 3668 */ 3669 olddtv = ((Elf_Addr**)oldsegbase)[1]; 3670 for (i = 0; i < olddtv[1]; i++) { 3671 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 3672 dtv[i+2] = olddtv[i+2]; 3673 olddtv[i+2] = 0; 3674 } 3675 } 3676 3677 /* 3678 * We assume that this block was the one we created with 3679 * allocate_initial_tls(). 3680 */ 3681 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 3682 } else { 3683 for (obj = objs; obj; obj = obj->next) { 3684 if (obj->tlsoffset) { 3685 addr = segbase - obj->tlsoffset; 3686 memset((void*) (addr + obj->tlsinitsize), 3687 0, obj->tlssize - obj->tlsinitsize); 3688 if (obj->tlsinit) 3689 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 3690 dtv[obj->tlsindex + 1] = addr; 3691 } 3692 } 3693 } 3694 3695 return (void*) segbase; 3696 } 3697 3698 void 3699 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 3700 { 3701 size_t size; 3702 Elf_Addr* dtv; 3703 int dtvsize, i; 3704 Elf_Addr tlsstart, tlsend; 3705 3706 /* 3707 * Figure out the size of the initial TLS block so that we can 3708 * find stuff which ___tls_get_addr() allocated dynamically. 3709 */ 3710 size = round(tls_static_space, tcbalign); 3711 3712 dtv = ((Elf_Addr**)tls)[1]; 3713 dtvsize = dtv[1]; 3714 tlsend = (Elf_Addr) tls; 3715 tlsstart = tlsend - size; 3716 for (i = 0; i < dtvsize; i++) { 3717 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 3718 free((void*) dtv[i+2]); 3719 } 3720 } 3721 3722 free((void*) tlsstart); 3723 free((void*) dtv); 3724 } 3725 3726 #endif 3727 3728 /* 3729 * Allocate TLS block for module with given index. 3730 */ 3731 void * 3732 allocate_module_tls(int index) 3733 { 3734 Obj_Entry* obj; 3735 char* p; 3736 3737 for (obj = obj_list; obj; obj = obj->next) { 3738 if (obj->tlsindex == index) 3739 break; 3740 } 3741 if (!obj) { 3742 _rtld_error("Can't find module with TLS index %d", index); 3743 die(); 3744 } 3745 3746 p = malloc(obj->tlssize); 3747 if (p == NULL) { 3748 _rtld_error("Cannot allocate TLS block for index %d", index); 3749 die(); 3750 } 3751 memcpy(p, obj->tlsinit, obj->tlsinitsize); 3752 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 3753 3754 return p; 3755 } 3756 3757 bool 3758 allocate_tls_offset(Obj_Entry *obj) 3759 { 3760 size_t off; 3761 3762 if (obj->tls_done) 3763 return true; 3764 3765 if (obj->tlssize == 0) { 3766 obj->tls_done = true; 3767 return true; 3768 } 3769 3770 if (obj->tlsindex == 1) 3771 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 3772 else 3773 off = calculate_tls_offset(tls_last_offset, tls_last_size, 3774 obj->tlssize, obj->tlsalign); 3775 3776 /* 3777 * If we have already fixed the size of the static TLS block, we 3778 * must stay within that size. When allocating the static TLS, we 3779 * leave a small amount of space spare to be used for dynamically 3780 * loading modules which use static TLS. 3781 */ 3782 if (tls_static_space) { 3783 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 3784 return false; 3785 } 3786 3787 tls_last_offset = obj->tlsoffset = off; 3788 tls_last_size = obj->tlssize; 3789 obj->tls_done = true; 3790 3791 return true; 3792 } 3793 3794 void 3795 free_tls_offset(Obj_Entry *obj) 3796 { 3797 3798 /* 3799 * If we were the last thing to allocate out of the static TLS 3800 * block, we give our space back to the 'allocator'. This is a 3801 * simplistic workaround to allow libGL.so.1 to be loaded and 3802 * unloaded multiple times. 3803 */ 3804 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 3805 == calculate_tls_end(tls_last_offset, tls_last_size)) { 3806 tls_last_offset -= obj->tlssize; 3807 tls_last_size = 0; 3808 } 3809 } 3810 3811 void * 3812 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 3813 { 3814 void *ret; 3815 RtldLockState lockstate; 3816 3817 wlock_acquire(rtld_bind_lock, &lockstate); 3818 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 3819 lock_release(rtld_bind_lock, &lockstate); 3820 return (ret); 3821 } 3822 3823 void 3824 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 3825 { 3826 RtldLockState lockstate; 3827 3828 wlock_acquire(rtld_bind_lock, &lockstate); 3829 free_tls(tcb, tcbsize, tcbalign); 3830 lock_release(rtld_bind_lock, &lockstate); 3831 } 3832 3833 static void 3834 object_add_name(Obj_Entry *obj, const char *name) 3835 { 3836 Name_Entry *entry; 3837 size_t len; 3838 3839 len = strlen(name); 3840 entry = malloc(sizeof(Name_Entry) + len); 3841 3842 if (entry != NULL) { 3843 strcpy(entry->name, name); 3844 STAILQ_INSERT_TAIL(&obj->names, entry, link); 3845 } 3846 } 3847 3848 static int 3849 object_match_name(const Obj_Entry *obj, const char *name) 3850 { 3851 Name_Entry *entry; 3852 3853 STAILQ_FOREACH(entry, &obj->names, link) { 3854 if (strcmp(name, entry->name) == 0) 3855 return (1); 3856 } 3857 return (0); 3858 } 3859 3860 static Obj_Entry * 3861 locate_dependency(const Obj_Entry *obj, const char *name) 3862 { 3863 const Objlist_Entry *entry; 3864 const Needed_Entry *needed; 3865 3866 STAILQ_FOREACH(entry, &list_main, link) { 3867 if (object_match_name(entry->obj, name)) 3868 return entry->obj; 3869 } 3870 3871 for (needed = obj->needed; needed != NULL; needed = needed->next) { 3872 if (strcmp(obj->strtab + needed->name, name) == 0 || 3873 (needed->obj != NULL && object_match_name(needed->obj, name))) { 3874 /* 3875 * If there is DT_NEEDED for the name we are looking for, 3876 * we are all set. Note that object might not be found if 3877 * dependency was not loaded yet, so the function can 3878 * return NULL here. This is expected and handled 3879 * properly by the caller. 3880 */ 3881 return (needed->obj); 3882 } 3883 } 3884 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 3885 obj->path, name); 3886 die(); 3887 } 3888 3889 static int 3890 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 3891 const Elf_Vernaux *vna) 3892 { 3893 const Elf_Verdef *vd; 3894 const char *vername; 3895 3896 vername = refobj->strtab + vna->vna_name; 3897 vd = depobj->verdef; 3898 if (vd == NULL) { 3899 _rtld_error("%s: version %s required by %s not defined", 3900 depobj->path, vername, refobj->path); 3901 return (-1); 3902 } 3903 for (;;) { 3904 if (vd->vd_version != VER_DEF_CURRENT) { 3905 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 3906 depobj->path, vd->vd_version); 3907 return (-1); 3908 } 3909 if (vna->vna_hash == vd->vd_hash) { 3910 const Elf_Verdaux *aux = (const Elf_Verdaux *) 3911 ((char *)vd + vd->vd_aux); 3912 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 3913 return (0); 3914 } 3915 if (vd->vd_next == 0) 3916 break; 3917 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3918 } 3919 if (vna->vna_flags & VER_FLG_WEAK) 3920 return (0); 3921 _rtld_error("%s: version %s required by %s not found", 3922 depobj->path, vername, refobj->path); 3923 return (-1); 3924 } 3925 3926 static int 3927 rtld_verify_object_versions(Obj_Entry *obj) 3928 { 3929 const Elf_Verneed *vn; 3930 const Elf_Verdef *vd; 3931 const Elf_Verdaux *vda; 3932 const Elf_Vernaux *vna; 3933 const Obj_Entry *depobj; 3934 int maxvernum, vernum; 3935 3936 maxvernum = 0; 3937 /* 3938 * Walk over defined and required version records and figure out 3939 * max index used by any of them. Do very basic sanity checking 3940 * while there. 3941 */ 3942 vn = obj->verneed; 3943 while (vn != NULL) { 3944 if (vn->vn_version != VER_NEED_CURRENT) { 3945 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 3946 obj->path, vn->vn_version); 3947 return (-1); 3948 } 3949 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 3950 for (;;) { 3951 vernum = VER_NEED_IDX(vna->vna_other); 3952 if (vernum > maxvernum) 3953 maxvernum = vernum; 3954 if (vna->vna_next == 0) 3955 break; 3956 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 3957 } 3958 if (vn->vn_next == 0) 3959 break; 3960 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 3961 } 3962 3963 vd = obj->verdef; 3964 while (vd != NULL) { 3965 if (vd->vd_version != VER_DEF_CURRENT) { 3966 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 3967 obj->path, vd->vd_version); 3968 return (-1); 3969 } 3970 vernum = VER_DEF_IDX(vd->vd_ndx); 3971 if (vernum > maxvernum) 3972 maxvernum = vernum; 3973 if (vd->vd_next == 0) 3974 break; 3975 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 3976 } 3977 3978 if (maxvernum == 0) 3979 return (0); 3980 3981 /* 3982 * Store version information in array indexable by version index. 3983 * Verify that object version requirements are satisfied along the 3984 * way. 3985 */ 3986 obj->vernum = maxvernum + 1; 3987 obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry)); 3988 3989 vd = obj->verdef; 3990 while (vd != NULL) { 3991 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 3992 vernum = VER_DEF_IDX(vd->vd_ndx); 3993 assert(vernum <= maxvernum); 3994 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 3995 obj->vertab[vernum].hash = vd->vd_hash; 3996 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 3997 obj->vertab[vernum].file = NULL; 3998 obj->vertab[vernum].flags = 0; 3999 } 4000 if (vd->vd_next == 0) 4001 break; 4002 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4003 } 4004 4005 vn = obj->verneed; 4006 while (vn != NULL) { 4007 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4008 if (depobj == NULL) 4009 return (-1); 4010 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4011 for (;;) { 4012 if (check_object_provided_version(obj, depobj, vna)) 4013 return (-1); 4014 vernum = VER_NEED_IDX(vna->vna_other); 4015 assert(vernum <= maxvernum); 4016 obj->vertab[vernum].hash = vna->vna_hash; 4017 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4018 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4019 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4020 VER_INFO_HIDDEN : 0; 4021 if (vna->vna_next == 0) 4022 break; 4023 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4024 } 4025 if (vn->vn_next == 0) 4026 break; 4027 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4028 } 4029 return 0; 4030 } 4031 4032 static int 4033 rtld_verify_versions(const Objlist *objlist) 4034 { 4035 Objlist_Entry *entry; 4036 int rc; 4037 4038 rc = 0; 4039 STAILQ_FOREACH(entry, objlist, link) { 4040 /* 4041 * Skip dummy objects or objects that have their version requirements 4042 * already checked. 4043 */ 4044 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4045 continue; 4046 if (rtld_verify_object_versions(entry->obj) == -1) { 4047 rc = -1; 4048 if (ld_tracing == NULL) 4049 break; 4050 } 4051 } 4052 if (rc == 0 || ld_tracing != NULL) 4053 rc = rtld_verify_object_versions(&obj_rtld); 4054 return rc; 4055 } 4056 4057 const Ver_Entry * 4058 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4059 { 4060 Elf_Versym vernum; 4061 4062 if (obj->vertab) { 4063 vernum = VER_NDX(obj->versyms[symnum]); 4064 if (vernum >= obj->vernum) { 4065 _rtld_error("%s: symbol %s has wrong verneed value %d", 4066 obj->path, obj->strtab + symnum, vernum); 4067 } else if (obj->vertab[vernum].hash != 0) { 4068 return &obj->vertab[vernum]; 4069 } 4070 } 4071 return NULL; 4072 } 4073 4074 int 4075 _rtld_get_stack_prot(void) 4076 { 4077 4078 return (stack_prot); 4079 } 4080 4081 static void 4082 map_stacks_exec(RtldLockState *lockstate) 4083 { 4084 void (*thr_map_stacks_exec)(void); 4085 4086 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4087 return; 4088 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4089 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4090 if (thr_map_stacks_exec != NULL) { 4091 stack_prot |= PROT_EXEC; 4092 thr_map_stacks_exec(); 4093 } 4094 } 4095 4096 void 4097 symlook_init(SymLook *dst, const char *name) 4098 { 4099 4100 bzero(dst, sizeof(*dst)); 4101 dst->name = name; 4102 dst->hash = elf_hash(name); 4103 } 4104 4105 static void 4106 symlook_init_from_req(SymLook *dst, const SymLook *src) 4107 { 4108 4109 dst->name = src->name; 4110 dst->hash = src->hash; 4111 dst->ventry = src->ventry; 4112 dst->flags = src->flags; 4113 dst->defobj_out = NULL; 4114 dst->sym_out = NULL; 4115 dst->lockstate = src->lockstate; 4116 } 4117 4118 /* 4119 * Overrides for libc_pic-provided functions. 4120 */ 4121 4122 int 4123 __getosreldate(void) 4124 { 4125 size_t len; 4126 int oid[2]; 4127 int error, osrel; 4128 4129 if (osreldate != 0) 4130 return (osreldate); 4131 4132 oid[0] = CTL_KERN; 4133 oid[1] = KERN_OSRELDATE; 4134 osrel = 0; 4135 len = sizeof(osrel); 4136 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4137 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4138 osreldate = osrel; 4139 return (osreldate); 4140 } 4141 4142 /* 4143 * No unresolved symbols for rtld. 4144 */ 4145 void 4146 __pthread_cxa_finalize(struct dl_phdr_info *a) 4147 { 4148 } 4149