1 /*- 2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 4 * Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>. 5 * Copyright 2012 John Marino <draco@marino.st>. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 /* 32 * Dynamic linker for ELF. 33 * 34 * John Polstra <jdp@polstra.com>. 35 */ 36 37 #ifndef __GNUC__ 38 #error "GCC is needed to compile this file" 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/mount.h> 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 #include <sys/sysctl.h> 46 #include <sys/uio.h> 47 #include <sys/utsname.h> 48 #include <sys/ktrace.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "rtld.h" 62 #include "libmap.h" 63 #include "rtld_tls.h" 64 #include "rtld_printf.h" 65 #include "notes.h" 66 67 #ifndef COMPAT_32BIT 68 #define PATH_RTLD "/libexec/ld-elf.so.1" 69 #else 70 #define PATH_RTLD "/libexec/ld-elf32.so.1" 71 #endif 72 73 /* Types. */ 74 typedef void (*func_ptr_type)(); 75 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 76 77 /* 78 * Function declarations. 79 */ 80 static const char *basename(const char *); 81 static void die(void) __dead2; 82 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 83 const Elf_Dyn **, const Elf_Dyn **); 84 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 85 const Elf_Dyn *); 86 static void digest_dynamic(Obj_Entry *, int); 87 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 88 static Obj_Entry *dlcheck(void *); 89 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 90 int lo_flags, int mode, RtldLockState *lockstate); 91 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 92 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 93 static bool donelist_check(DoneList *, const Obj_Entry *); 94 static void errmsg_restore(char *); 95 static char *errmsg_save(void); 96 static void *fill_search_info(const char *, size_t, void *); 97 static char *find_library(const char *, const Obj_Entry *); 98 static const char *gethints(bool); 99 static void init_dag(Obj_Entry *); 100 static void init_rtld(caddr_t, Elf_Auxinfo **); 101 static void initlist_add_neededs(Needed_Entry *, Objlist *); 102 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 103 static void linkmap_add(Obj_Entry *); 104 static void linkmap_delete(Obj_Entry *); 105 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 106 static void unload_filtees(Obj_Entry *); 107 static int load_needed_objects(Obj_Entry *, int); 108 static int load_preload_objects(void); 109 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 110 static void map_stacks_exec(RtldLockState *); 111 static Obj_Entry *obj_from_addr(const void *); 112 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 113 static void objlist_call_init(Objlist *, RtldLockState *); 114 static void objlist_clear(Objlist *); 115 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 116 static void objlist_init(Objlist *); 117 static void objlist_push_head(Objlist *, Obj_Entry *); 118 static void objlist_push_tail(Objlist *, Obj_Entry *); 119 static void objlist_remove(Objlist *, Obj_Entry *); 120 static void *path_enumerate(const char *, path_enum_proc, void *); 121 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 122 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 123 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 124 int flags, RtldLockState *lockstate); 125 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 126 RtldLockState *); 127 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 128 int flags, RtldLockState *lockstate); 129 static int rtld_dirname(const char *, char *); 130 static int rtld_dirname_abs(const char *, char *); 131 static void *rtld_dlopen(const char *name, int fd, int mode); 132 static void rtld_exit(void); 133 static char *search_library_path(const char *, const char *); 134 static const void **get_program_var_addr(const char *, RtldLockState *); 135 static void set_program_var(const char *, const void *); 136 static int symlook_default(SymLook *, const Obj_Entry *refobj); 137 static int symlook_global(SymLook *, DoneList *); 138 static void symlook_init_from_req(SymLook *, const SymLook *); 139 static int symlook_list(SymLook *, const Objlist *, DoneList *); 140 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 141 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 142 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 143 static void trace_loaded_objects(Obj_Entry *); 144 static void unlink_object(Obj_Entry *); 145 static void unload_object(Obj_Entry *); 146 static void unref_dag(Obj_Entry *); 147 static void ref_dag(Obj_Entry *); 148 static char *origin_subst_one(char *, const char *, const char *, bool); 149 static char *origin_subst(char *, const char *); 150 static void preinit_main(void); 151 static int rtld_verify_versions(const Objlist *); 152 static int rtld_verify_object_versions(Obj_Entry *); 153 static void object_add_name(Obj_Entry *, const char *); 154 static int object_match_name(const Obj_Entry *, const char *); 155 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 156 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 157 struct dl_phdr_info *phdr_info); 158 static uint32_t gnu_hash(const char *); 159 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 160 const unsigned long); 161 162 void r_debug_state(struct r_debug *, struct link_map *) __noinline; 163 164 /* 165 * Data declarations. 166 */ 167 static char *error_message; /* Message for dlerror(), or NULL */ 168 struct r_debug r_debug; /* for GDB; */ 169 static bool libmap_disable; /* Disable libmap */ 170 static bool ld_loadfltr; /* Immediate filters processing */ 171 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 172 static bool trust; /* False for setuid and setgid programs */ 173 static bool dangerous_ld_env; /* True if environment variables have been 174 used to affect the libraries loaded */ 175 static char *ld_bind_now; /* Environment variable for immediate binding */ 176 static char *ld_debug; /* Environment variable for debugging */ 177 static char *ld_library_path; /* Environment variable for search path */ 178 static char *ld_preload; /* Environment variable for libraries to 179 load first */ 180 static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 181 static char *ld_tracing; /* Called from ldd to print libs */ 182 static char *ld_utrace; /* Use utrace() to log events. */ 183 static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 184 static Obj_Entry **obj_tail; /* Link field of last object in list */ 185 static Obj_Entry *obj_main; /* The main program shared object */ 186 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 187 static unsigned int obj_count; /* Number of objects in obj_list */ 188 static unsigned int obj_loads; /* Number of objects in obj_list */ 189 190 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 191 STAILQ_HEAD_INITIALIZER(list_global); 192 static Objlist list_main = /* Objects loaded at program startup */ 193 STAILQ_HEAD_INITIALIZER(list_main); 194 static Objlist list_fini = /* Objects needing fini() calls */ 195 STAILQ_HEAD_INITIALIZER(list_fini); 196 197 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 198 199 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 200 201 extern Elf_Dyn _DYNAMIC; 202 #pragma weak _DYNAMIC 203 #ifndef RTLD_IS_DYNAMIC 204 #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 205 #endif 206 207 int osreldate, pagesize; 208 209 long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 210 211 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 212 static int max_stack_flags; 213 214 /* 215 * Global declarations normally provided by crt1. The dynamic linker is 216 * not built with crt1, so we have to provide them ourselves. 217 */ 218 char *__progname; 219 char **environ; 220 221 /* 222 * Used to pass argc, argv to init functions. 223 */ 224 int main_argc; 225 char **main_argv; 226 227 /* 228 * Globals to control TLS allocation. 229 */ 230 size_t tls_last_offset; /* Static TLS offset of last module */ 231 size_t tls_last_size; /* Static TLS size of last module */ 232 size_t tls_static_space; /* Static TLS space allocated */ 233 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 234 int tls_max_index = 1; /* Largest module index allocated */ 235 236 bool ld_library_path_rpath = false; 237 238 /* 239 * Fill in a DoneList with an allocation large enough to hold all of 240 * the currently-loaded objects. Keep this as a macro since it calls 241 * alloca and we want that to occur within the scope of the caller. 242 */ 243 #define donelist_init(dlp) \ 244 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 245 assert((dlp)->objs != NULL), \ 246 (dlp)->num_alloc = obj_count, \ 247 (dlp)->num_used = 0) 248 249 #define UTRACE_DLOPEN_START 1 250 #define UTRACE_DLOPEN_STOP 2 251 #define UTRACE_DLCLOSE_START 3 252 #define UTRACE_DLCLOSE_STOP 4 253 #define UTRACE_LOAD_OBJECT 5 254 #define UTRACE_UNLOAD_OBJECT 6 255 #define UTRACE_ADD_RUNDEP 7 256 #define UTRACE_PRELOAD_FINISHED 8 257 #define UTRACE_INIT_CALL 9 258 #define UTRACE_FINI_CALL 10 259 260 struct utrace_rtld { 261 char sig[4]; /* 'RTLD' */ 262 int event; 263 void *handle; 264 void *mapbase; /* Used for 'parent' and 'init/fini' */ 265 size_t mapsize; 266 int refcnt; /* Used for 'mode' */ 267 char name[MAXPATHLEN]; 268 }; 269 270 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 271 if (ld_utrace != NULL) \ 272 ld_utrace_log(e, h, mb, ms, r, n); \ 273 } while (0) 274 275 static void 276 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 277 int refcnt, const char *name) 278 { 279 struct utrace_rtld ut; 280 281 ut.sig[0] = 'R'; 282 ut.sig[1] = 'T'; 283 ut.sig[2] = 'L'; 284 ut.sig[3] = 'D'; 285 ut.event = event; 286 ut.handle = handle; 287 ut.mapbase = mapbase; 288 ut.mapsize = mapsize; 289 ut.refcnt = refcnt; 290 bzero(ut.name, sizeof(ut.name)); 291 if (name) 292 strlcpy(ut.name, name, sizeof(ut.name)); 293 utrace(&ut, sizeof(ut)); 294 } 295 296 /* 297 * Main entry point for dynamic linking. The first argument is the 298 * stack pointer. The stack is expected to be laid out as described 299 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 300 * Specifically, the stack pointer points to a word containing 301 * ARGC. Following that in the stack is a null-terminated sequence 302 * of pointers to argument strings. Then comes a null-terminated 303 * sequence of pointers to environment strings. Finally, there is a 304 * sequence of "auxiliary vector" entries. 305 * 306 * The second argument points to a place to store the dynamic linker's 307 * exit procedure pointer and the third to a place to store the main 308 * program's object. 309 * 310 * The return value is the main program's entry point. 311 */ 312 func_ptr_type 313 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 314 { 315 Elf_Auxinfo *aux_info[AT_COUNT]; 316 int i; 317 int argc; 318 char **argv; 319 char **env; 320 Elf_Auxinfo *aux; 321 Elf_Auxinfo *auxp; 322 const char *argv0; 323 Objlist_Entry *entry; 324 Obj_Entry *obj; 325 Obj_Entry **preload_tail; 326 Objlist initlist; 327 RtldLockState lockstate; 328 char *library_path_rpath; 329 int mib[2]; 330 size_t len; 331 332 /* 333 * On entry, the dynamic linker itself has not been relocated yet. 334 * Be very careful not to reference any global data until after 335 * init_rtld has returned. It is OK to reference file-scope statics 336 * and string constants, and to call static and global functions. 337 */ 338 339 /* Find the auxiliary vector on the stack. */ 340 argc = *sp++; 341 argv = (char **) sp; 342 sp += argc + 1; /* Skip over arguments and NULL terminator */ 343 env = (char **) sp; 344 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 345 ; 346 aux = (Elf_Auxinfo *) sp; 347 348 /* Digest the auxiliary vector. */ 349 for (i = 0; i < AT_COUNT; i++) 350 aux_info[i] = NULL; 351 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 352 if (auxp->a_type < AT_COUNT) 353 aux_info[auxp->a_type] = auxp; 354 } 355 356 /* Initialize and relocate ourselves. */ 357 assert(aux_info[AT_BASE] != NULL); 358 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 359 360 __progname = obj_rtld.path; 361 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 362 environ = env; 363 main_argc = argc; 364 main_argv = argv; 365 366 if (aux_info[AT_CANARY] != NULL && 367 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 368 i = aux_info[AT_CANARYLEN]->a_un.a_val; 369 if (i > sizeof(__stack_chk_guard)) 370 i = sizeof(__stack_chk_guard); 371 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 372 } else { 373 mib[0] = CTL_KERN; 374 mib[1] = KERN_ARND; 375 376 len = sizeof(__stack_chk_guard); 377 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 378 len != sizeof(__stack_chk_guard)) { 379 /* If sysctl was unsuccessful, use the "terminator canary". */ 380 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 381 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 382 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 383 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 384 } 385 } 386 387 trust = !issetugid(); 388 389 ld_bind_now = getenv(LD_ "BIND_NOW"); 390 /* 391 * If the process is tainted, then we un-set the dangerous environment 392 * variables. The process will be marked as tainted until setuid(2) 393 * is called. If any child process calls setuid(2) we do not want any 394 * future processes to honor the potentially un-safe variables. 395 */ 396 if (!trust) { 397 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 398 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 399 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 400 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 401 _rtld_error("environment corrupt; aborting"); 402 die(); 403 } 404 } 405 ld_debug = getenv(LD_ "DEBUG"); 406 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 407 libmap_override = getenv(LD_ "LIBMAP"); 408 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 409 ld_preload = getenv(LD_ "PRELOAD"); 410 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 411 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 412 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 413 if (library_path_rpath != NULL) { 414 if (library_path_rpath[0] == 'y' || 415 library_path_rpath[0] == 'Y' || 416 library_path_rpath[0] == '1') 417 ld_library_path_rpath = true; 418 else 419 ld_library_path_rpath = false; 420 } 421 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 422 (ld_library_path != NULL) || (ld_preload != NULL) || 423 (ld_elf_hints_path != NULL) || ld_loadfltr; 424 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 425 ld_utrace = getenv(LD_ "UTRACE"); 426 427 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 428 ld_elf_hints_path = _PATH_ELF_HINTS; 429 430 if (ld_debug != NULL && *ld_debug != '\0') 431 debug = 1; 432 dbg("%s is initialized, base address = %p", __progname, 433 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 434 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 435 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 436 437 dbg("initializing thread locks"); 438 lockdflt_init(); 439 440 /* 441 * Load the main program, or process its program header if it is 442 * already loaded. 443 */ 444 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 445 int fd = aux_info[AT_EXECFD]->a_un.a_val; 446 dbg("loading main program"); 447 obj_main = map_object(fd, argv0, NULL); 448 close(fd); 449 if (obj_main == NULL) 450 die(); 451 max_stack_flags = obj->stack_flags; 452 } else { /* Main program already loaded. */ 453 const Elf_Phdr *phdr; 454 int phnum; 455 caddr_t entry; 456 457 dbg("processing main program's program header"); 458 assert(aux_info[AT_PHDR] != NULL); 459 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 460 assert(aux_info[AT_PHNUM] != NULL); 461 phnum = aux_info[AT_PHNUM]->a_un.a_val; 462 assert(aux_info[AT_PHENT] != NULL); 463 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 464 assert(aux_info[AT_ENTRY] != NULL); 465 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 466 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 467 die(); 468 } 469 470 if (aux_info[AT_EXECPATH] != 0) { 471 char *kexecpath; 472 char buf[MAXPATHLEN]; 473 474 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 475 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 476 if (kexecpath[0] == '/') 477 obj_main->path = kexecpath; 478 else if (getcwd(buf, sizeof(buf)) == NULL || 479 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 480 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 481 obj_main->path = xstrdup(argv0); 482 else 483 obj_main->path = xstrdup(buf); 484 } else { 485 dbg("No AT_EXECPATH"); 486 obj_main->path = xstrdup(argv0); 487 } 488 dbg("obj_main path %s", obj_main->path); 489 obj_main->mainprog = true; 490 491 if (aux_info[AT_STACKPROT] != NULL && 492 aux_info[AT_STACKPROT]->a_un.a_val != 0) 493 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 494 495 /* 496 * Get the actual dynamic linker pathname from the executable if 497 * possible. (It should always be possible.) That ensures that 498 * gdb will find the right dynamic linker even if a non-standard 499 * one is being used. 500 */ 501 if (obj_main->interp != NULL && 502 strcmp(obj_main->interp, obj_rtld.path) != 0) { 503 free(obj_rtld.path); 504 obj_rtld.path = xstrdup(obj_main->interp); 505 __progname = obj_rtld.path; 506 } 507 508 digest_dynamic(obj_main, 0); 509 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 510 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 511 obj_main->dynsymcount); 512 513 linkmap_add(obj_main); 514 linkmap_add(&obj_rtld); 515 516 /* Link the main program into the list of objects. */ 517 *obj_tail = obj_main; 518 obj_tail = &obj_main->next; 519 obj_count++; 520 obj_loads++; 521 522 /* Initialize a fake symbol for resolving undefined weak references. */ 523 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 524 sym_zero.st_shndx = SHN_UNDEF; 525 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 526 527 if (!libmap_disable) 528 libmap_disable = (bool)lm_init(libmap_override); 529 530 dbg("loading LD_PRELOAD libraries"); 531 if (load_preload_objects() == -1) 532 die(); 533 preload_tail = obj_tail; 534 535 dbg("loading needed objects"); 536 if (load_needed_objects(obj_main, 0) == -1) 537 die(); 538 539 /* Make a list of all objects loaded at startup. */ 540 for (obj = obj_list; obj != NULL; obj = obj->next) { 541 objlist_push_tail(&list_main, obj); 542 obj->refcount++; 543 } 544 545 dbg("checking for required versions"); 546 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 547 die(); 548 549 if (ld_tracing) { /* We're done */ 550 trace_loaded_objects(obj_main); 551 exit(0); 552 } 553 554 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 555 dump_relocations(obj_main); 556 exit (0); 557 } 558 559 /* 560 * Processing tls relocations requires having the tls offsets 561 * initialized. Prepare offsets before starting initial 562 * relocation processing. 563 */ 564 dbg("initializing initial thread local storage offsets"); 565 STAILQ_FOREACH(entry, &list_main, link) { 566 /* 567 * Allocate all the initial objects out of the static TLS 568 * block even if they didn't ask for it. 569 */ 570 allocate_tls_offset(entry->obj); 571 } 572 573 if (relocate_objects(obj_main, 574 ld_bind_now != NULL && *ld_bind_now != '\0', 575 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 576 die(); 577 578 dbg("doing copy relocations"); 579 if (do_copy_relocations(obj_main) == -1) 580 die(); 581 582 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 583 dump_relocations(obj_main); 584 exit (0); 585 } 586 587 /* 588 * Setup TLS for main thread. This must be done after the 589 * relocations are processed, since tls initialization section 590 * might be the subject for relocations. 591 */ 592 dbg("initializing initial thread local storage"); 593 allocate_initial_tls(obj_list); 594 595 dbg("initializing key program variables"); 596 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 597 set_program_var("environ", env); 598 set_program_var("__elf_aux_vector", aux); 599 600 /* Make a list of init functions to call. */ 601 objlist_init(&initlist); 602 initlist_add_objects(obj_list, preload_tail, &initlist); 603 604 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 605 606 map_stacks_exec(NULL); 607 608 dbg("resolving ifuncs"); 609 if (resolve_objects_ifunc(obj_main, 610 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 611 NULL) == -1) 612 die(); 613 614 if (!obj_main->crt_no_init) { 615 /* 616 * Make sure we don't call the main program's init and fini 617 * functions for binaries linked with old crt1 which calls 618 * _init itself. 619 */ 620 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 621 obj_main->preinit_array = obj_main->init_array = 622 obj_main->fini_array = (Elf_Addr)NULL; 623 } 624 625 wlock_acquire(rtld_bind_lock, &lockstate); 626 if (obj_main->crt_no_init) 627 preinit_main(); 628 objlist_call_init(&initlist, &lockstate); 629 objlist_clear(&initlist); 630 dbg("loading filtees"); 631 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 632 if (ld_loadfltr || obj->z_loadfltr) 633 load_filtees(obj, 0, &lockstate); 634 } 635 lock_release(rtld_bind_lock, &lockstate); 636 637 dbg("transferring control to program entry point = %p", obj_main->entry); 638 639 /* Return the exit procedure and the program entry point. */ 640 *exit_proc = rtld_exit; 641 *objp = obj_main; 642 return (func_ptr_type) obj_main->entry; 643 } 644 645 void * 646 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 647 { 648 void *ptr; 649 Elf_Addr target; 650 651 ptr = (void *)make_function_pointer(def, obj); 652 target = ((Elf_Addr (*)(void))ptr)(); 653 return ((void *)target); 654 } 655 656 Elf_Addr 657 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 658 { 659 const Elf_Rel *rel; 660 const Elf_Sym *def; 661 const Obj_Entry *defobj; 662 Elf_Addr *where; 663 Elf_Addr target; 664 RtldLockState lockstate; 665 666 rlock_acquire(rtld_bind_lock, &lockstate); 667 if (sigsetjmp(lockstate.env, 0) != 0) 668 lock_upgrade(rtld_bind_lock, &lockstate); 669 if (obj->pltrel) 670 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 671 else 672 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 673 674 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 675 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 676 &lockstate); 677 if (def == NULL) 678 die(); 679 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 680 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 681 else 682 target = (Elf_Addr)(defobj->relocbase + def->st_value); 683 684 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 685 defobj->strtab + def->st_name, basename(obj->path), 686 (void *)target, basename(defobj->path)); 687 688 /* 689 * Write the new contents for the jmpslot. Note that depending on 690 * architecture, the value which we need to return back to the 691 * lazy binding trampoline may or may not be the target 692 * address. The value returned from reloc_jmpslot() is the value 693 * that the trampoline needs. 694 */ 695 target = reloc_jmpslot(where, target, defobj, obj, rel); 696 lock_release(rtld_bind_lock, &lockstate); 697 return target; 698 } 699 700 /* 701 * Error reporting function. Use it like printf. If formats the message 702 * into a buffer, and sets things up so that the next call to dlerror() 703 * will return the message. 704 */ 705 void 706 _rtld_error(const char *fmt, ...) 707 { 708 static char buf[512]; 709 va_list ap; 710 711 va_start(ap, fmt); 712 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 713 error_message = buf; 714 va_end(ap); 715 } 716 717 /* 718 * Return a dynamically-allocated copy of the current error message, if any. 719 */ 720 static char * 721 errmsg_save(void) 722 { 723 return error_message == NULL ? NULL : xstrdup(error_message); 724 } 725 726 /* 727 * Restore the current error message from a copy which was previously saved 728 * by errmsg_save(). The copy is freed. 729 */ 730 static void 731 errmsg_restore(char *saved_msg) 732 { 733 if (saved_msg == NULL) 734 error_message = NULL; 735 else { 736 _rtld_error("%s", saved_msg); 737 free(saved_msg); 738 } 739 } 740 741 static const char * 742 basename(const char *name) 743 { 744 const char *p = strrchr(name, '/'); 745 return p != NULL ? p + 1 : name; 746 } 747 748 static struct utsname uts; 749 750 static char * 751 origin_subst_one(char *real, const char *kw, const char *subst, 752 bool may_free) 753 { 754 char *p, *p1, *res, *resp; 755 int subst_len, kw_len, subst_count, old_len, new_len; 756 757 kw_len = strlen(kw); 758 759 /* 760 * First, count the number of the keyword occurences, to 761 * preallocate the final string. 762 */ 763 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 764 p1 = strstr(p, kw); 765 if (p1 == NULL) 766 break; 767 } 768 769 /* 770 * If the keyword is not found, just return. 771 */ 772 if (subst_count == 0) 773 return (may_free ? real : xstrdup(real)); 774 775 /* 776 * There is indeed something to substitute. Calculate the 777 * length of the resulting string, and allocate it. 778 */ 779 subst_len = strlen(subst); 780 old_len = strlen(real); 781 new_len = old_len + (subst_len - kw_len) * subst_count; 782 res = xmalloc(new_len + 1); 783 784 /* 785 * Now, execute the substitution loop. 786 */ 787 for (p = real, resp = res;;) { 788 p1 = strstr(p, kw); 789 if (p1 != NULL) { 790 /* Copy the prefix before keyword. */ 791 memcpy(resp, p, p1 - p); 792 resp += p1 - p; 793 /* Keyword replacement. */ 794 memcpy(resp, subst, subst_len); 795 resp += subst_len; 796 p = p1 + kw_len; 797 } else 798 break; 799 } 800 801 /* Copy to the end of string and finish. */ 802 strcat(resp, p); 803 if (may_free) 804 free(real); 805 return (res); 806 } 807 808 static char * 809 origin_subst(char *real, const char *origin_path) 810 { 811 char *res1, *res2, *res3, *res4; 812 813 if (uts.sysname[0] == '\0') { 814 if (uname(&uts) != 0) { 815 _rtld_error("utsname failed: %d", errno); 816 return (NULL); 817 } 818 } 819 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 820 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 821 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 822 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 823 return (res4); 824 } 825 826 static void 827 die(void) 828 { 829 const char *msg = dlerror(); 830 831 if (msg == NULL) 832 msg = "Fatal error"; 833 rtld_fdputstr(STDERR_FILENO, msg); 834 rtld_fdputchar(STDERR_FILENO, '\n'); 835 _exit(1); 836 } 837 838 /* 839 * Process a shared object's DYNAMIC section, and save the important 840 * information in its Obj_Entry structure. 841 */ 842 static void 843 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 844 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 845 { 846 const Elf_Dyn *dynp; 847 Needed_Entry **needed_tail = &obj->needed; 848 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 849 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 850 const Elf_Hashelt *hashtab; 851 const Elf32_Word *hashval; 852 Elf32_Word bkt, nmaskwords; 853 int bloom_size32; 854 bool nmw_power2; 855 int plttype = DT_REL; 856 857 *dyn_rpath = NULL; 858 *dyn_soname = NULL; 859 *dyn_runpath = NULL; 860 861 obj->bind_now = false; 862 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 863 switch (dynp->d_tag) { 864 865 case DT_REL: 866 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 867 break; 868 869 case DT_RELSZ: 870 obj->relsize = dynp->d_un.d_val; 871 break; 872 873 case DT_RELENT: 874 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 875 break; 876 877 case DT_JMPREL: 878 obj->pltrel = (const Elf_Rel *) 879 (obj->relocbase + dynp->d_un.d_ptr); 880 break; 881 882 case DT_PLTRELSZ: 883 obj->pltrelsize = dynp->d_un.d_val; 884 break; 885 886 case DT_RELA: 887 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 888 break; 889 890 case DT_RELASZ: 891 obj->relasize = dynp->d_un.d_val; 892 break; 893 894 case DT_RELAENT: 895 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 896 break; 897 898 case DT_PLTREL: 899 plttype = dynp->d_un.d_val; 900 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 901 break; 902 903 case DT_SYMTAB: 904 obj->symtab = (const Elf_Sym *) 905 (obj->relocbase + dynp->d_un.d_ptr); 906 break; 907 908 case DT_SYMENT: 909 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 910 break; 911 912 case DT_STRTAB: 913 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 914 break; 915 916 case DT_STRSZ: 917 obj->strsize = dynp->d_un.d_val; 918 break; 919 920 case DT_VERNEED: 921 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 922 dynp->d_un.d_val); 923 break; 924 925 case DT_VERNEEDNUM: 926 obj->verneednum = dynp->d_un.d_val; 927 break; 928 929 case DT_VERDEF: 930 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 931 dynp->d_un.d_val); 932 break; 933 934 case DT_VERDEFNUM: 935 obj->verdefnum = dynp->d_un.d_val; 936 break; 937 938 case DT_VERSYM: 939 obj->versyms = (const Elf_Versym *)(obj->relocbase + 940 dynp->d_un.d_val); 941 break; 942 943 case DT_HASH: 944 { 945 hashtab = (const Elf_Hashelt *)(obj->relocbase + 946 dynp->d_un.d_ptr); 947 obj->nbuckets = hashtab[0]; 948 obj->nchains = hashtab[1]; 949 obj->buckets = hashtab + 2; 950 obj->chains = obj->buckets + obj->nbuckets; 951 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 952 obj->buckets != NULL; 953 } 954 break; 955 956 case DT_GNU_HASH: 957 { 958 hashtab = (const Elf_Hashelt *)(obj->relocbase + 959 dynp->d_un.d_ptr); 960 obj->nbuckets_gnu = hashtab[0]; 961 obj->symndx_gnu = hashtab[1]; 962 nmaskwords = hashtab[2]; 963 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 964 /* Number of bitmask words is required to be power of 2 */ 965 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 966 obj->maskwords_bm_gnu = nmaskwords - 1; 967 obj->shift2_gnu = hashtab[3]; 968 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 969 obj->buckets_gnu = hashtab + 4 + bloom_size32; 970 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 971 obj->symndx_gnu; 972 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 973 obj->buckets_gnu != NULL; 974 } 975 break; 976 977 case DT_NEEDED: 978 if (!obj->rtld) { 979 Needed_Entry *nep = NEW(Needed_Entry); 980 nep->name = dynp->d_un.d_val; 981 nep->obj = NULL; 982 nep->next = NULL; 983 984 *needed_tail = nep; 985 needed_tail = &nep->next; 986 } 987 break; 988 989 case DT_FILTER: 990 if (!obj->rtld) { 991 Needed_Entry *nep = NEW(Needed_Entry); 992 nep->name = dynp->d_un.d_val; 993 nep->obj = NULL; 994 nep->next = NULL; 995 996 *needed_filtees_tail = nep; 997 needed_filtees_tail = &nep->next; 998 } 999 break; 1000 1001 case DT_AUXILIARY: 1002 if (!obj->rtld) { 1003 Needed_Entry *nep = NEW(Needed_Entry); 1004 nep->name = dynp->d_un.d_val; 1005 nep->obj = NULL; 1006 nep->next = NULL; 1007 1008 *needed_aux_filtees_tail = nep; 1009 needed_aux_filtees_tail = &nep->next; 1010 } 1011 break; 1012 1013 case DT_PLTGOT: 1014 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1015 break; 1016 1017 case DT_TEXTREL: 1018 obj->textrel = true; 1019 break; 1020 1021 case DT_SYMBOLIC: 1022 obj->symbolic = true; 1023 break; 1024 1025 case DT_RPATH: 1026 /* 1027 * We have to wait until later to process this, because we 1028 * might not have gotten the address of the string table yet. 1029 */ 1030 *dyn_rpath = dynp; 1031 break; 1032 1033 case DT_SONAME: 1034 *dyn_soname = dynp; 1035 break; 1036 1037 case DT_RUNPATH: 1038 *dyn_runpath = dynp; 1039 break; 1040 1041 case DT_INIT: 1042 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1043 break; 1044 1045 case DT_PREINIT_ARRAY: 1046 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1047 break; 1048 1049 case DT_PREINIT_ARRAYSZ: 1050 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1051 break; 1052 1053 case DT_INIT_ARRAY: 1054 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1055 break; 1056 1057 case DT_INIT_ARRAYSZ: 1058 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1059 break; 1060 1061 case DT_FINI: 1062 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1063 break; 1064 1065 case DT_FINI_ARRAY: 1066 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1067 break; 1068 1069 case DT_FINI_ARRAYSZ: 1070 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1071 break; 1072 1073 /* 1074 * Don't process DT_DEBUG on MIPS as the dynamic section 1075 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1076 */ 1077 1078 #ifndef __mips__ 1079 case DT_DEBUG: 1080 /* XXX - not implemented yet */ 1081 if (!early) 1082 dbg("Filling in DT_DEBUG entry"); 1083 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1084 break; 1085 #endif 1086 1087 case DT_FLAGS: 1088 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1089 obj->z_origin = true; 1090 if (dynp->d_un.d_val & DF_SYMBOLIC) 1091 obj->symbolic = true; 1092 if (dynp->d_un.d_val & DF_TEXTREL) 1093 obj->textrel = true; 1094 if (dynp->d_un.d_val & DF_BIND_NOW) 1095 obj->bind_now = true; 1096 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1097 ;*/ 1098 break; 1099 #ifdef __mips__ 1100 case DT_MIPS_LOCAL_GOTNO: 1101 obj->local_gotno = dynp->d_un.d_val; 1102 break; 1103 1104 case DT_MIPS_SYMTABNO: 1105 obj->symtabno = dynp->d_un.d_val; 1106 break; 1107 1108 case DT_MIPS_GOTSYM: 1109 obj->gotsym = dynp->d_un.d_val; 1110 break; 1111 1112 case DT_MIPS_RLD_MAP: 1113 #ifdef notyet 1114 if (!early) 1115 dbg("Filling in DT_DEBUG entry"); 1116 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1117 #endif 1118 break; 1119 #endif 1120 1121 case DT_FLAGS_1: 1122 if (dynp->d_un.d_val & DF_1_NOOPEN) 1123 obj->z_noopen = true; 1124 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1125 obj->z_origin = true; 1126 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1127 XXX ;*/ 1128 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1129 obj->bind_now = true; 1130 if (dynp->d_un.d_val & DF_1_NODELETE) 1131 obj->z_nodelete = true; 1132 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1133 obj->z_loadfltr = true; 1134 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1135 obj->z_nodeflib = true; 1136 break; 1137 1138 default: 1139 if (!early) { 1140 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1141 (long)dynp->d_tag); 1142 } 1143 break; 1144 } 1145 } 1146 1147 obj->traced = false; 1148 1149 if (plttype == DT_RELA) { 1150 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1151 obj->pltrel = NULL; 1152 obj->pltrelasize = obj->pltrelsize; 1153 obj->pltrelsize = 0; 1154 } 1155 1156 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1157 if (obj->valid_hash_sysv) 1158 obj->dynsymcount = obj->nchains; 1159 else if (obj->valid_hash_gnu) { 1160 obj->dynsymcount = 0; 1161 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1162 if (obj->buckets_gnu[bkt] == 0) 1163 continue; 1164 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1165 do 1166 obj->dynsymcount++; 1167 while ((*hashval++ & 1u) == 0); 1168 } 1169 obj->dynsymcount += obj->symndx_gnu; 1170 } 1171 } 1172 1173 static void 1174 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1175 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1176 { 1177 1178 if (obj->z_origin && obj->origin_path == NULL) { 1179 obj->origin_path = xmalloc(PATH_MAX); 1180 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1181 die(); 1182 } 1183 1184 if (dyn_runpath != NULL) { 1185 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1186 if (obj->z_origin) 1187 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1188 } 1189 else if (dyn_rpath != NULL) { 1190 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1191 if (obj->z_origin) 1192 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1193 } 1194 1195 if (dyn_soname != NULL) 1196 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1197 } 1198 1199 static void 1200 digest_dynamic(Obj_Entry *obj, int early) 1201 { 1202 const Elf_Dyn *dyn_rpath; 1203 const Elf_Dyn *dyn_soname; 1204 const Elf_Dyn *dyn_runpath; 1205 1206 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1207 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1208 } 1209 1210 /* 1211 * Process a shared object's program header. This is used only for the 1212 * main program, when the kernel has already loaded the main program 1213 * into memory before calling the dynamic linker. It creates and 1214 * returns an Obj_Entry structure. 1215 */ 1216 static Obj_Entry * 1217 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1218 { 1219 Obj_Entry *obj; 1220 const Elf_Phdr *phlimit = phdr + phnum; 1221 const Elf_Phdr *ph; 1222 Elf_Addr note_start, note_end; 1223 int nsegs = 0; 1224 1225 obj = obj_new(); 1226 for (ph = phdr; ph < phlimit; ph++) { 1227 if (ph->p_type != PT_PHDR) 1228 continue; 1229 1230 obj->phdr = phdr; 1231 obj->phsize = ph->p_memsz; 1232 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1233 break; 1234 } 1235 1236 obj->stack_flags = PF_X | PF_R | PF_W; 1237 1238 for (ph = phdr; ph < phlimit; ph++) { 1239 switch (ph->p_type) { 1240 1241 case PT_INTERP: 1242 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1243 break; 1244 1245 case PT_LOAD: 1246 if (nsegs == 0) { /* First load segment */ 1247 obj->vaddrbase = trunc_page(ph->p_vaddr); 1248 obj->mapbase = obj->vaddrbase + obj->relocbase; 1249 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1250 obj->vaddrbase; 1251 } else { /* Last load segment */ 1252 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1253 obj->vaddrbase; 1254 } 1255 nsegs++; 1256 break; 1257 1258 case PT_DYNAMIC: 1259 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1260 break; 1261 1262 case PT_TLS: 1263 obj->tlsindex = 1; 1264 obj->tlssize = ph->p_memsz; 1265 obj->tlsalign = ph->p_align; 1266 obj->tlsinitsize = ph->p_filesz; 1267 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1268 break; 1269 1270 case PT_GNU_STACK: 1271 obj->stack_flags = ph->p_flags; 1272 break; 1273 1274 case PT_GNU_RELRO: 1275 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1276 obj->relro_size = round_page(ph->p_memsz); 1277 break; 1278 1279 case PT_NOTE: 1280 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1281 note_end = note_start + ph->p_filesz; 1282 digest_notes(obj, note_start, note_end); 1283 break; 1284 } 1285 } 1286 if (nsegs < 1) { 1287 _rtld_error("%s: too few PT_LOAD segments", path); 1288 return NULL; 1289 } 1290 1291 obj->entry = entry; 1292 return obj; 1293 } 1294 1295 void 1296 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1297 { 1298 const Elf_Note *note; 1299 const char *note_name; 1300 uintptr_t p; 1301 1302 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1303 note = (const Elf_Note *)((const char *)(note + 1) + 1304 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1305 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1306 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1307 note->n_descsz != sizeof(int32_t)) 1308 continue; 1309 if (note->n_type != ABI_NOTETYPE && 1310 note->n_type != CRT_NOINIT_NOTETYPE) 1311 continue; 1312 note_name = (const char *)(note + 1); 1313 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1314 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1315 continue; 1316 switch (note->n_type) { 1317 case ABI_NOTETYPE: 1318 /* FreeBSD osrel note */ 1319 p = (uintptr_t)(note + 1); 1320 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1321 obj->osrel = *(const int32_t *)(p); 1322 dbg("note osrel %d", obj->osrel); 1323 break; 1324 case CRT_NOINIT_NOTETYPE: 1325 /* FreeBSD 'crt does not call init' note */ 1326 obj->crt_no_init = true; 1327 dbg("note crt_no_init"); 1328 break; 1329 } 1330 } 1331 } 1332 1333 static Obj_Entry * 1334 dlcheck(void *handle) 1335 { 1336 Obj_Entry *obj; 1337 1338 for (obj = obj_list; obj != NULL; obj = obj->next) 1339 if (obj == (Obj_Entry *) handle) 1340 break; 1341 1342 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1343 _rtld_error("Invalid shared object handle %p", handle); 1344 return NULL; 1345 } 1346 return obj; 1347 } 1348 1349 /* 1350 * If the given object is already in the donelist, return true. Otherwise 1351 * add the object to the list and return false. 1352 */ 1353 static bool 1354 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1355 { 1356 unsigned int i; 1357 1358 for (i = 0; i < dlp->num_used; i++) 1359 if (dlp->objs[i] == obj) 1360 return true; 1361 /* 1362 * Our donelist allocation should always be sufficient. But if 1363 * our threads locking isn't working properly, more shared objects 1364 * could have been loaded since we allocated the list. That should 1365 * never happen, but we'll handle it properly just in case it does. 1366 */ 1367 if (dlp->num_used < dlp->num_alloc) 1368 dlp->objs[dlp->num_used++] = obj; 1369 return false; 1370 } 1371 1372 /* 1373 * Hash function for symbol table lookup. Don't even think about changing 1374 * this. It is specified by the System V ABI. 1375 */ 1376 unsigned long 1377 elf_hash(const char *name) 1378 { 1379 const unsigned char *p = (const unsigned char *) name; 1380 unsigned long h = 0; 1381 unsigned long g; 1382 1383 while (*p != '\0') { 1384 h = (h << 4) + *p++; 1385 if ((g = h & 0xf0000000) != 0) 1386 h ^= g >> 24; 1387 h &= ~g; 1388 } 1389 return h; 1390 } 1391 1392 /* 1393 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1394 * unsigned in case it's implemented with a wider type. 1395 */ 1396 static uint32_t 1397 gnu_hash(const char *s) 1398 { 1399 uint32_t h; 1400 unsigned char c; 1401 1402 h = 5381; 1403 for (c = *s; c != '\0'; c = *++s) 1404 h = h * 33 + c; 1405 return (h & 0xffffffff); 1406 } 1407 1408 /* 1409 * Find the library with the given name, and return its full pathname. 1410 * The returned string is dynamically allocated. Generates an error 1411 * message and returns NULL if the library cannot be found. 1412 * 1413 * If the second argument is non-NULL, then it refers to an already- 1414 * loaded shared object, whose library search path will be searched. 1415 * 1416 * The search order is: 1417 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1418 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1419 * LD_LIBRARY_PATH 1420 * DT_RUNPATH in the referencing file 1421 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1422 * from list) 1423 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1424 * 1425 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1426 */ 1427 static char * 1428 find_library(const char *xname, const Obj_Entry *refobj) 1429 { 1430 char *pathname; 1431 char *name; 1432 bool nodeflib, objgiven; 1433 1434 objgiven = refobj != NULL; 1435 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1436 if (xname[0] != '/' && !trust) { 1437 _rtld_error("Absolute pathname required for shared object \"%s\"", 1438 xname); 1439 return NULL; 1440 } 1441 if (objgiven && refobj->z_origin) { 1442 return (origin_subst(__DECONST(char *, xname), 1443 refobj->origin_path)); 1444 } else { 1445 return (xstrdup(xname)); 1446 } 1447 } 1448 1449 if (libmap_disable || !objgiven || 1450 (name = lm_find(refobj->path, xname)) == NULL) 1451 name = (char *)xname; 1452 1453 dbg(" Searching for \"%s\"", name); 1454 1455 /* 1456 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1457 * back to pre-conforming behaviour if user requested so with 1458 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1459 * nodeflib. 1460 */ 1461 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1462 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1463 (refobj != NULL && 1464 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1465 (pathname = search_library_path(name, gethints(false))) != NULL || 1466 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1467 return (pathname); 1468 } else { 1469 nodeflib = objgiven ? refobj->z_nodeflib : false; 1470 if ((objgiven && 1471 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1472 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1473 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1474 (pathname = search_library_path(name, ld_library_path)) != NULL || 1475 (objgiven && 1476 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1477 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1478 (objgiven && !nodeflib && 1479 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1480 return (pathname); 1481 } 1482 1483 if (objgiven && refobj->path != NULL) { 1484 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1485 name, basename(refobj->path)); 1486 } else { 1487 _rtld_error("Shared object \"%s\" not found", name); 1488 } 1489 return NULL; 1490 } 1491 1492 /* 1493 * Given a symbol number in a referencing object, find the corresponding 1494 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1495 * no definition was found. Returns a pointer to the Obj_Entry of the 1496 * defining object via the reference parameter DEFOBJ_OUT. 1497 */ 1498 const Elf_Sym * 1499 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1500 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1501 RtldLockState *lockstate) 1502 { 1503 const Elf_Sym *ref; 1504 const Elf_Sym *def; 1505 const Obj_Entry *defobj; 1506 SymLook req; 1507 const char *name; 1508 int res; 1509 1510 /* 1511 * If we have already found this symbol, get the information from 1512 * the cache. 1513 */ 1514 if (symnum >= refobj->dynsymcount) 1515 return NULL; /* Bad object */ 1516 if (cache != NULL && cache[symnum].sym != NULL) { 1517 *defobj_out = cache[symnum].obj; 1518 return cache[symnum].sym; 1519 } 1520 1521 ref = refobj->symtab + symnum; 1522 name = refobj->strtab + ref->st_name; 1523 def = NULL; 1524 defobj = NULL; 1525 1526 /* 1527 * We don't have to do a full scale lookup if the symbol is local. 1528 * We know it will bind to the instance in this load module; to 1529 * which we already have a pointer (ie ref). By not doing a lookup, 1530 * we not only improve performance, but it also avoids unresolvable 1531 * symbols when local symbols are not in the hash table. This has 1532 * been seen with the ia64 toolchain. 1533 */ 1534 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1535 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1536 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1537 symnum); 1538 } 1539 symlook_init(&req, name); 1540 req.flags = flags; 1541 req.ventry = fetch_ventry(refobj, symnum); 1542 req.lockstate = lockstate; 1543 res = symlook_default(&req, refobj); 1544 if (res == 0) { 1545 def = req.sym_out; 1546 defobj = req.defobj_out; 1547 } 1548 } else { 1549 def = ref; 1550 defobj = refobj; 1551 } 1552 1553 /* 1554 * If we found no definition and the reference is weak, treat the 1555 * symbol as having the value zero. 1556 */ 1557 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1558 def = &sym_zero; 1559 defobj = obj_main; 1560 } 1561 1562 if (def != NULL) { 1563 *defobj_out = defobj; 1564 /* Record the information in the cache to avoid subsequent lookups. */ 1565 if (cache != NULL) { 1566 cache[symnum].sym = def; 1567 cache[symnum].obj = defobj; 1568 } 1569 } else { 1570 if (refobj != &obj_rtld) 1571 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1572 } 1573 return def; 1574 } 1575 1576 /* 1577 * Return the search path from the ldconfig hints file, reading it if 1578 * necessary. If nostdlib is true, then the default search paths are 1579 * not added to result. 1580 * 1581 * Returns NULL if there are problems with the hints file, 1582 * or if the search path there is empty. 1583 */ 1584 static const char * 1585 gethints(bool nostdlib) 1586 { 1587 static char *hints, *filtered_path; 1588 struct elfhints_hdr hdr; 1589 struct fill_search_info_args sargs, hargs; 1590 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1591 struct dl_serpath *SLPpath, *hintpath; 1592 char *p; 1593 unsigned int SLPndx, hintndx, fndx, fcount; 1594 int fd; 1595 size_t flen; 1596 bool skip; 1597 1598 /* First call, read the hints file */ 1599 if (hints == NULL) { 1600 /* Keep from trying again in case the hints file is bad. */ 1601 hints = ""; 1602 1603 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1604 return (NULL); 1605 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1606 hdr.magic != ELFHINTS_MAGIC || 1607 hdr.version != 1) { 1608 close(fd); 1609 return (NULL); 1610 } 1611 p = xmalloc(hdr.dirlistlen + 1); 1612 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1613 read(fd, p, hdr.dirlistlen + 1) != 1614 (ssize_t)hdr.dirlistlen + 1) { 1615 free(p); 1616 close(fd); 1617 return (NULL); 1618 } 1619 hints = p; 1620 close(fd); 1621 } 1622 1623 /* 1624 * If caller agreed to receive list which includes the default 1625 * paths, we are done. Otherwise, if we still did not 1626 * calculated filtered result, do it now. 1627 */ 1628 if (!nostdlib) 1629 return (hints[0] != '\0' ? hints : NULL); 1630 if (filtered_path != NULL) 1631 goto filt_ret; 1632 1633 /* 1634 * Obtain the list of all configured search paths, and the 1635 * list of the default paths. 1636 * 1637 * First estimate the size of the results. 1638 */ 1639 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1640 smeta.dls_cnt = 0; 1641 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1642 hmeta.dls_cnt = 0; 1643 1644 sargs.request = RTLD_DI_SERINFOSIZE; 1645 sargs.serinfo = &smeta; 1646 hargs.request = RTLD_DI_SERINFOSIZE; 1647 hargs.serinfo = &hmeta; 1648 1649 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1650 path_enumerate(p, fill_search_info, &hargs); 1651 1652 SLPinfo = xmalloc(smeta.dls_size); 1653 hintinfo = xmalloc(hmeta.dls_size); 1654 1655 /* 1656 * Next fetch both sets of paths. 1657 */ 1658 sargs.request = RTLD_DI_SERINFO; 1659 sargs.serinfo = SLPinfo; 1660 sargs.serpath = &SLPinfo->dls_serpath[0]; 1661 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1662 1663 hargs.request = RTLD_DI_SERINFO; 1664 hargs.serinfo = hintinfo; 1665 hargs.serpath = &hintinfo->dls_serpath[0]; 1666 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1667 1668 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1669 path_enumerate(p, fill_search_info, &hargs); 1670 1671 /* 1672 * Now calculate the difference between two sets, by excluding 1673 * standard paths from the full set. 1674 */ 1675 fndx = 0; 1676 fcount = 0; 1677 filtered_path = xmalloc(hdr.dirlistlen + 1); 1678 hintpath = &hintinfo->dls_serpath[0]; 1679 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1680 skip = false; 1681 SLPpath = &SLPinfo->dls_serpath[0]; 1682 /* 1683 * Check each standard path against current. 1684 */ 1685 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1686 /* matched, skip the path */ 1687 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1688 skip = true; 1689 break; 1690 } 1691 } 1692 if (skip) 1693 continue; 1694 /* 1695 * Not matched against any standard path, add the path 1696 * to result. Separate consequtive paths with ':'. 1697 */ 1698 if (fcount > 0) { 1699 filtered_path[fndx] = ':'; 1700 fndx++; 1701 } 1702 fcount++; 1703 flen = strlen(hintpath->dls_name); 1704 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1705 fndx += flen; 1706 } 1707 filtered_path[fndx] = '\0'; 1708 1709 free(SLPinfo); 1710 free(hintinfo); 1711 1712 filt_ret: 1713 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1714 } 1715 1716 static void 1717 init_dag(Obj_Entry *root) 1718 { 1719 const Needed_Entry *needed; 1720 const Objlist_Entry *elm; 1721 DoneList donelist; 1722 1723 if (root->dag_inited) 1724 return; 1725 donelist_init(&donelist); 1726 1727 /* Root object belongs to own DAG. */ 1728 objlist_push_tail(&root->dldags, root); 1729 objlist_push_tail(&root->dagmembers, root); 1730 donelist_check(&donelist, root); 1731 1732 /* 1733 * Add dependencies of root object to DAG in breadth order 1734 * by exploiting the fact that each new object get added 1735 * to the tail of the dagmembers list. 1736 */ 1737 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1738 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1739 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1740 continue; 1741 objlist_push_tail(&needed->obj->dldags, root); 1742 objlist_push_tail(&root->dagmembers, needed->obj); 1743 } 1744 } 1745 root->dag_inited = true; 1746 } 1747 1748 static void 1749 process_nodelete(Obj_Entry *root) 1750 { 1751 const Objlist_Entry *elm; 1752 1753 /* 1754 * Walk over object DAG and process every dependent object that 1755 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1756 * which then should have its reference upped separately. 1757 */ 1758 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1759 if (elm->obj != NULL && elm->obj->z_nodelete && 1760 !elm->obj->ref_nodel) { 1761 dbg("obj %s nodelete", elm->obj->path); 1762 init_dag(elm->obj); 1763 ref_dag(elm->obj); 1764 elm->obj->ref_nodel = true; 1765 } 1766 } 1767 } 1768 /* 1769 * Initialize the dynamic linker. The argument is the address at which 1770 * the dynamic linker has been mapped into memory. The primary task of 1771 * this function is to relocate the dynamic linker. 1772 */ 1773 static void 1774 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1775 { 1776 Obj_Entry objtmp; /* Temporary rtld object */ 1777 const Elf_Dyn *dyn_rpath; 1778 const Elf_Dyn *dyn_soname; 1779 const Elf_Dyn *dyn_runpath; 1780 1781 /* 1782 * Conjure up an Obj_Entry structure for the dynamic linker. 1783 * 1784 * The "path" member can't be initialized yet because string constants 1785 * cannot yet be accessed. Below we will set it correctly. 1786 */ 1787 memset(&objtmp, 0, sizeof(objtmp)); 1788 objtmp.path = NULL; 1789 objtmp.rtld = true; 1790 objtmp.mapbase = mapbase; 1791 #ifdef PIC 1792 objtmp.relocbase = mapbase; 1793 #endif 1794 if (RTLD_IS_DYNAMIC()) { 1795 objtmp.dynamic = rtld_dynamic(&objtmp); 1796 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1797 assert(objtmp.needed == NULL); 1798 #if !defined(__mips__) 1799 /* MIPS has a bogus DT_TEXTREL. */ 1800 assert(!objtmp.textrel); 1801 #endif 1802 1803 /* 1804 * Temporarily put the dynamic linker entry into the object list, so 1805 * that symbols can be found. 1806 */ 1807 1808 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1809 } 1810 1811 /* Initialize the object list. */ 1812 obj_tail = &obj_list; 1813 1814 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1815 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1816 1817 if (aux_info[AT_PAGESZ] != NULL) 1818 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1819 if (aux_info[AT_OSRELDATE] != NULL) 1820 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1821 1822 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1823 1824 /* Replace the path with a dynamically allocated copy. */ 1825 obj_rtld.path = xstrdup(PATH_RTLD); 1826 1827 r_debug.r_brk = r_debug_state; 1828 r_debug.r_state = RT_CONSISTENT; 1829 } 1830 1831 /* 1832 * Add the init functions from a needed object list (and its recursive 1833 * needed objects) to "list". This is not used directly; it is a helper 1834 * function for initlist_add_objects(). The write lock must be held 1835 * when this function is called. 1836 */ 1837 static void 1838 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1839 { 1840 /* Recursively process the successor needed objects. */ 1841 if (needed->next != NULL) 1842 initlist_add_neededs(needed->next, list); 1843 1844 /* Process the current needed object. */ 1845 if (needed->obj != NULL) 1846 initlist_add_objects(needed->obj, &needed->obj->next, list); 1847 } 1848 1849 /* 1850 * Scan all of the DAGs rooted in the range of objects from "obj" to 1851 * "tail" and add their init functions to "list". This recurses over 1852 * the DAGs and ensure the proper init ordering such that each object's 1853 * needed libraries are initialized before the object itself. At the 1854 * same time, this function adds the objects to the global finalization 1855 * list "list_fini" in the opposite order. The write lock must be 1856 * held when this function is called. 1857 */ 1858 static void 1859 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1860 { 1861 1862 if (obj->init_scanned || obj->init_done) 1863 return; 1864 obj->init_scanned = true; 1865 1866 /* Recursively process the successor objects. */ 1867 if (&obj->next != tail) 1868 initlist_add_objects(obj->next, tail, list); 1869 1870 /* Recursively process the needed objects. */ 1871 if (obj->needed != NULL) 1872 initlist_add_neededs(obj->needed, list); 1873 if (obj->needed_filtees != NULL) 1874 initlist_add_neededs(obj->needed_filtees, list); 1875 if (obj->needed_aux_filtees != NULL) 1876 initlist_add_neededs(obj->needed_aux_filtees, list); 1877 1878 /* Add the object to the init list. */ 1879 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1880 obj->init_array != (Elf_Addr)NULL) 1881 objlist_push_tail(list, obj); 1882 1883 /* Add the object to the global fini list in the reverse order. */ 1884 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1885 && !obj->on_fini_list) { 1886 objlist_push_head(&list_fini, obj); 1887 obj->on_fini_list = true; 1888 } 1889 } 1890 1891 #ifndef FPTR_TARGET 1892 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1893 #endif 1894 1895 static void 1896 free_needed_filtees(Needed_Entry *n) 1897 { 1898 Needed_Entry *needed, *needed1; 1899 1900 for (needed = n; needed != NULL; needed = needed->next) { 1901 if (needed->obj != NULL) { 1902 dlclose(needed->obj); 1903 needed->obj = NULL; 1904 } 1905 } 1906 for (needed = n; needed != NULL; needed = needed1) { 1907 needed1 = needed->next; 1908 free(needed); 1909 } 1910 } 1911 1912 static void 1913 unload_filtees(Obj_Entry *obj) 1914 { 1915 1916 free_needed_filtees(obj->needed_filtees); 1917 obj->needed_filtees = NULL; 1918 free_needed_filtees(obj->needed_aux_filtees); 1919 obj->needed_aux_filtees = NULL; 1920 obj->filtees_loaded = false; 1921 } 1922 1923 static void 1924 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1925 RtldLockState *lockstate) 1926 { 1927 1928 for (; needed != NULL; needed = needed->next) { 1929 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1930 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1931 RTLD_LOCAL, lockstate); 1932 } 1933 } 1934 1935 static void 1936 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1937 { 1938 1939 lock_restart_for_upgrade(lockstate); 1940 if (!obj->filtees_loaded) { 1941 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1942 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1943 obj->filtees_loaded = true; 1944 } 1945 } 1946 1947 static int 1948 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1949 { 1950 Obj_Entry *obj1; 1951 1952 for (; needed != NULL; needed = needed->next) { 1953 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1954 flags & ~RTLD_LO_NOLOAD); 1955 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1956 return (-1); 1957 } 1958 return (0); 1959 } 1960 1961 /* 1962 * Given a shared object, traverse its list of needed objects, and load 1963 * each of them. Returns 0 on success. Generates an error message and 1964 * returns -1 on failure. 1965 */ 1966 static int 1967 load_needed_objects(Obj_Entry *first, int flags) 1968 { 1969 Obj_Entry *obj; 1970 1971 for (obj = first; obj != NULL; obj = obj->next) { 1972 if (process_needed(obj, obj->needed, flags) == -1) 1973 return (-1); 1974 } 1975 return (0); 1976 } 1977 1978 static int 1979 load_preload_objects(void) 1980 { 1981 char *p = ld_preload; 1982 static const char delim[] = " \t:;"; 1983 1984 if (p == NULL) 1985 return 0; 1986 1987 p += strspn(p, delim); 1988 while (*p != '\0') { 1989 size_t len = strcspn(p, delim); 1990 char savech; 1991 1992 savech = p[len]; 1993 p[len] = '\0'; 1994 if (load_object(p, -1, NULL, 0) == NULL) 1995 return -1; /* XXX - cleanup */ 1996 p[len] = savech; 1997 p += len; 1998 p += strspn(p, delim); 1999 } 2000 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2001 return 0; 2002 } 2003 2004 static const char * 2005 printable_path(const char *path) 2006 { 2007 2008 return (path == NULL ? "<unknown>" : path); 2009 } 2010 2011 /* 2012 * Load a shared object into memory, if it is not already loaded. The 2013 * object may be specified by name or by user-supplied file descriptor 2014 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2015 * duplicate is. 2016 * 2017 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2018 * on failure. 2019 */ 2020 static Obj_Entry * 2021 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2022 { 2023 Obj_Entry *obj; 2024 int fd; 2025 struct stat sb; 2026 char *path; 2027 2028 if (name != NULL) { 2029 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2030 if (object_match_name(obj, name)) 2031 return (obj); 2032 } 2033 2034 path = find_library(name, refobj); 2035 if (path == NULL) 2036 return (NULL); 2037 } else 2038 path = NULL; 2039 2040 /* 2041 * If we didn't find a match by pathname, or the name is not 2042 * supplied, open the file and check again by device and inode. 2043 * This avoids false mismatches caused by multiple links or ".." 2044 * in pathnames. 2045 * 2046 * To avoid a race, we open the file and use fstat() rather than 2047 * using stat(). 2048 */ 2049 fd = -1; 2050 if (fd_u == -1) { 2051 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2052 _rtld_error("Cannot open \"%s\"", path); 2053 free(path); 2054 return (NULL); 2055 } 2056 } else { 2057 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2058 if (fd == -1) { 2059 _rtld_error("Cannot dup fd"); 2060 free(path); 2061 return (NULL); 2062 } 2063 } 2064 if (fstat(fd, &sb) == -1) { 2065 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2066 close(fd); 2067 free(path); 2068 return NULL; 2069 } 2070 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2071 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2072 break; 2073 if (obj != NULL && name != NULL) { 2074 object_add_name(obj, name); 2075 free(path); 2076 close(fd); 2077 return obj; 2078 } 2079 if (flags & RTLD_LO_NOLOAD) { 2080 free(path); 2081 close(fd); 2082 return (NULL); 2083 } 2084 2085 /* First use of this object, so we must map it in */ 2086 obj = do_load_object(fd, name, path, &sb, flags); 2087 if (obj == NULL) 2088 free(path); 2089 close(fd); 2090 2091 return obj; 2092 } 2093 2094 static Obj_Entry * 2095 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2096 int flags) 2097 { 2098 Obj_Entry *obj; 2099 struct statfs fs; 2100 2101 /* 2102 * but first, make sure that environment variables haven't been 2103 * used to circumvent the noexec flag on a filesystem. 2104 */ 2105 if (dangerous_ld_env) { 2106 if (fstatfs(fd, &fs) != 0) { 2107 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2108 return NULL; 2109 } 2110 if (fs.f_flags & MNT_NOEXEC) { 2111 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2112 return NULL; 2113 } 2114 } 2115 dbg("loading \"%s\"", printable_path(path)); 2116 obj = map_object(fd, printable_path(path), sbp); 2117 if (obj == NULL) 2118 return NULL; 2119 2120 /* 2121 * If DT_SONAME is present in the object, digest_dynamic2 already 2122 * added it to the object names. 2123 */ 2124 if (name != NULL) 2125 object_add_name(obj, name); 2126 obj->path = path; 2127 digest_dynamic(obj, 0); 2128 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2129 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2130 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2131 RTLD_LO_DLOPEN) { 2132 dbg("refusing to load non-loadable \"%s\"", obj->path); 2133 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2134 munmap(obj->mapbase, obj->mapsize); 2135 obj_free(obj); 2136 return (NULL); 2137 } 2138 2139 *obj_tail = obj; 2140 obj_tail = &obj->next; 2141 obj_count++; 2142 obj_loads++; 2143 linkmap_add(obj); /* for GDB & dlinfo() */ 2144 max_stack_flags |= obj->stack_flags; 2145 2146 dbg(" %p .. %p: %s", obj->mapbase, 2147 obj->mapbase + obj->mapsize - 1, obj->path); 2148 if (obj->textrel) 2149 dbg(" WARNING: %s has impure text", obj->path); 2150 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2151 obj->path); 2152 2153 return obj; 2154 } 2155 2156 static Obj_Entry * 2157 obj_from_addr(const void *addr) 2158 { 2159 Obj_Entry *obj; 2160 2161 for (obj = obj_list; obj != NULL; obj = obj->next) { 2162 if (addr < (void *) obj->mapbase) 2163 continue; 2164 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2165 return obj; 2166 } 2167 return NULL; 2168 } 2169 2170 static void 2171 preinit_main(void) 2172 { 2173 Elf_Addr *preinit_addr; 2174 int index; 2175 2176 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2177 if (preinit_addr == NULL) 2178 return; 2179 2180 for (index = 0; index < obj_main->preinit_array_num; index++) { 2181 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2182 dbg("calling preinit function for %s at %p", obj_main->path, 2183 (void *)preinit_addr[index]); 2184 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2185 0, 0, obj_main->path); 2186 call_init_pointer(obj_main, preinit_addr[index]); 2187 } 2188 } 2189 } 2190 2191 /* 2192 * Call the finalization functions for each of the objects in "list" 2193 * belonging to the DAG of "root" and referenced once. If NULL "root" 2194 * is specified, every finalization function will be called regardless 2195 * of the reference count and the list elements won't be freed. All of 2196 * the objects are expected to have non-NULL fini functions. 2197 */ 2198 static void 2199 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2200 { 2201 Objlist_Entry *elm; 2202 char *saved_msg; 2203 Elf_Addr *fini_addr; 2204 int index; 2205 2206 assert(root == NULL || root->refcount == 1); 2207 2208 /* 2209 * Preserve the current error message since a fini function might 2210 * call into the dynamic linker and overwrite it. 2211 */ 2212 saved_msg = errmsg_save(); 2213 do { 2214 STAILQ_FOREACH(elm, list, link) { 2215 if (root != NULL && (elm->obj->refcount != 1 || 2216 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2217 continue; 2218 /* Remove object from fini list to prevent recursive invocation. */ 2219 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2220 /* 2221 * XXX: If a dlopen() call references an object while the 2222 * fini function is in progress, we might end up trying to 2223 * unload the referenced object in dlclose() or the object 2224 * won't be unloaded although its fini function has been 2225 * called. 2226 */ 2227 lock_release(rtld_bind_lock, lockstate); 2228 2229 /* 2230 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2231 * When this happens, DT_FINI_ARRAY is processed first. 2232 */ 2233 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2234 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2235 for (index = elm->obj->fini_array_num - 1; index >= 0; 2236 index--) { 2237 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2238 dbg("calling fini function for %s at %p", 2239 elm->obj->path, (void *)fini_addr[index]); 2240 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2241 (void *)fini_addr[index], 0, 0, elm->obj->path); 2242 call_initfini_pointer(elm->obj, fini_addr[index]); 2243 } 2244 } 2245 } 2246 if (elm->obj->fini != (Elf_Addr)NULL) { 2247 dbg("calling fini function for %s at %p", elm->obj->path, 2248 (void *)elm->obj->fini); 2249 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2250 0, 0, elm->obj->path); 2251 call_initfini_pointer(elm->obj, elm->obj->fini); 2252 } 2253 wlock_acquire(rtld_bind_lock, lockstate); 2254 /* No need to free anything if process is going down. */ 2255 if (root != NULL) 2256 free(elm); 2257 /* 2258 * We must restart the list traversal after every fini call 2259 * because a dlclose() call from the fini function or from 2260 * another thread might have modified the reference counts. 2261 */ 2262 break; 2263 } 2264 } while (elm != NULL); 2265 errmsg_restore(saved_msg); 2266 } 2267 2268 /* 2269 * Call the initialization functions for each of the objects in 2270 * "list". All of the objects are expected to have non-NULL init 2271 * functions. 2272 */ 2273 static void 2274 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2275 { 2276 Objlist_Entry *elm; 2277 Obj_Entry *obj; 2278 char *saved_msg; 2279 Elf_Addr *init_addr; 2280 int index; 2281 2282 /* 2283 * Clean init_scanned flag so that objects can be rechecked and 2284 * possibly initialized earlier if any of vectors called below 2285 * cause the change by using dlopen. 2286 */ 2287 for (obj = obj_list; obj != NULL; obj = obj->next) 2288 obj->init_scanned = false; 2289 2290 /* 2291 * Preserve the current error message since an init function might 2292 * call into the dynamic linker and overwrite it. 2293 */ 2294 saved_msg = errmsg_save(); 2295 STAILQ_FOREACH(elm, list, link) { 2296 if (elm->obj->init_done) /* Initialized early. */ 2297 continue; 2298 /* 2299 * Race: other thread might try to use this object before current 2300 * one completes the initilization. Not much can be done here 2301 * without better locking. 2302 */ 2303 elm->obj->init_done = true; 2304 lock_release(rtld_bind_lock, lockstate); 2305 2306 /* 2307 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2308 * When this happens, DT_INIT is processed first. 2309 */ 2310 if (elm->obj->init != (Elf_Addr)NULL) { 2311 dbg("calling init function for %s at %p", elm->obj->path, 2312 (void *)elm->obj->init); 2313 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2314 0, 0, elm->obj->path); 2315 call_initfini_pointer(elm->obj, elm->obj->init); 2316 } 2317 init_addr = (Elf_Addr *)elm->obj->init_array; 2318 if (init_addr != NULL) { 2319 for (index = 0; index < elm->obj->init_array_num; index++) { 2320 if (init_addr[index] != 0 && init_addr[index] != 1) { 2321 dbg("calling init function for %s at %p", elm->obj->path, 2322 (void *)init_addr[index]); 2323 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2324 (void *)init_addr[index], 0, 0, elm->obj->path); 2325 call_init_pointer(elm->obj, init_addr[index]); 2326 } 2327 } 2328 } 2329 wlock_acquire(rtld_bind_lock, lockstate); 2330 } 2331 errmsg_restore(saved_msg); 2332 } 2333 2334 static void 2335 objlist_clear(Objlist *list) 2336 { 2337 Objlist_Entry *elm; 2338 2339 while (!STAILQ_EMPTY(list)) { 2340 elm = STAILQ_FIRST(list); 2341 STAILQ_REMOVE_HEAD(list, link); 2342 free(elm); 2343 } 2344 } 2345 2346 static Objlist_Entry * 2347 objlist_find(Objlist *list, const Obj_Entry *obj) 2348 { 2349 Objlist_Entry *elm; 2350 2351 STAILQ_FOREACH(elm, list, link) 2352 if (elm->obj == obj) 2353 return elm; 2354 return NULL; 2355 } 2356 2357 static void 2358 objlist_init(Objlist *list) 2359 { 2360 STAILQ_INIT(list); 2361 } 2362 2363 static void 2364 objlist_push_head(Objlist *list, Obj_Entry *obj) 2365 { 2366 Objlist_Entry *elm; 2367 2368 elm = NEW(Objlist_Entry); 2369 elm->obj = obj; 2370 STAILQ_INSERT_HEAD(list, elm, link); 2371 } 2372 2373 static void 2374 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2375 { 2376 Objlist_Entry *elm; 2377 2378 elm = NEW(Objlist_Entry); 2379 elm->obj = obj; 2380 STAILQ_INSERT_TAIL(list, elm, link); 2381 } 2382 2383 static void 2384 objlist_remove(Objlist *list, Obj_Entry *obj) 2385 { 2386 Objlist_Entry *elm; 2387 2388 if ((elm = objlist_find(list, obj)) != NULL) { 2389 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2390 free(elm); 2391 } 2392 } 2393 2394 /* 2395 * Relocate dag rooted in the specified object. 2396 * Returns 0 on success, or -1 on failure. 2397 */ 2398 2399 static int 2400 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2401 int flags, RtldLockState *lockstate) 2402 { 2403 Objlist_Entry *elm; 2404 int error; 2405 2406 error = 0; 2407 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2408 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2409 lockstate); 2410 if (error == -1) 2411 break; 2412 } 2413 return (error); 2414 } 2415 2416 /* 2417 * Relocate single object. 2418 * Returns 0 on success, or -1 on failure. 2419 */ 2420 static int 2421 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2422 int flags, RtldLockState *lockstate) 2423 { 2424 2425 if (obj->relocated) 2426 return (0); 2427 obj->relocated = true; 2428 if (obj != rtldobj) 2429 dbg("relocating \"%s\"", obj->path); 2430 2431 if (obj->symtab == NULL || obj->strtab == NULL || 2432 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2433 _rtld_error("%s: Shared object has no run-time symbol table", 2434 obj->path); 2435 return (-1); 2436 } 2437 2438 if (obj->textrel) { 2439 /* There are relocations to the write-protected text segment. */ 2440 if (mprotect(obj->mapbase, obj->textsize, 2441 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2442 _rtld_error("%s: Cannot write-enable text segment: %s", 2443 obj->path, rtld_strerror(errno)); 2444 return (-1); 2445 } 2446 } 2447 2448 /* Process the non-PLT relocations. */ 2449 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2450 return (-1); 2451 2452 if (obj->textrel) { /* Re-protected the text segment. */ 2453 if (mprotect(obj->mapbase, obj->textsize, 2454 PROT_READ|PROT_EXEC) == -1) { 2455 _rtld_error("%s: Cannot write-protect text segment: %s", 2456 obj->path, rtld_strerror(errno)); 2457 return (-1); 2458 } 2459 } 2460 2461 2462 /* Set the special PLT or GOT entries. */ 2463 init_pltgot(obj); 2464 2465 /* Process the PLT relocations. */ 2466 if (reloc_plt(obj) == -1) 2467 return (-1); 2468 /* Relocate the jump slots if we are doing immediate binding. */ 2469 if (obj->bind_now || bind_now) 2470 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2471 return (-1); 2472 2473 if (obj->relro_size > 0) { 2474 if (mprotect(obj->relro_page, obj->relro_size, 2475 PROT_READ) == -1) { 2476 _rtld_error("%s: Cannot enforce relro protection: %s", 2477 obj->path, rtld_strerror(errno)); 2478 return (-1); 2479 } 2480 } 2481 2482 /* 2483 * Set up the magic number and version in the Obj_Entry. These 2484 * were checked in the crt1.o from the original ElfKit, so we 2485 * set them for backward compatibility. 2486 */ 2487 obj->magic = RTLD_MAGIC; 2488 obj->version = RTLD_VERSION; 2489 2490 return (0); 2491 } 2492 2493 /* 2494 * Relocate newly-loaded shared objects. The argument is a pointer to 2495 * the Obj_Entry for the first such object. All objects from the first 2496 * to the end of the list of objects are relocated. Returns 0 on success, 2497 * or -1 on failure. 2498 */ 2499 static int 2500 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2501 int flags, RtldLockState *lockstate) 2502 { 2503 Obj_Entry *obj; 2504 int error; 2505 2506 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2507 error = relocate_object(obj, bind_now, rtldobj, flags, 2508 lockstate); 2509 if (error == -1) 2510 break; 2511 } 2512 return (error); 2513 } 2514 2515 /* 2516 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2517 * referencing STT_GNU_IFUNC symbols is postponed till the other 2518 * relocations are done. The indirect functions specified as 2519 * ifunc are allowed to call other symbols, so we need to have 2520 * objects relocated before asking for resolution from indirects. 2521 * 2522 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2523 * instead of the usual lazy handling of PLT slots. It is 2524 * consistent with how GNU does it. 2525 */ 2526 static int 2527 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2528 RtldLockState *lockstate) 2529 { 2530 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2531 return (-1); 2532 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2533 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2534 return (-1); 2535 return (0); 2536 } 2537 2538 static int 2539 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2540 RtldLockState *lockstate) 2541 { 2542 Obj_Entry *obj; 2543 2544 for (obj = first; obj != NULL; obj = obj->next) { 2545 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2546 return (-1); 2547 } 2548 return (0); 2549 } 2550 2551 static int 2552 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2553 RtldLockState *lockstate) 2554 { 2555 Objlist_Entry *elm; 2556 2557 STAILQ_FOREACH(elm, list, link) { 2558 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2559 lockstate) == -1) 2560 return (-1); 2561 } 2562 return (0); 2563 } 2564 2565 /* 2566 * Cleanup procedure. It will be called (by the atexit mechanism) just 2567 * before the process exits. 2568 */ 2569 static void 2570 rtld_exit(void) 2571 { 2572 RtldLockState lockstate; 2573 2574 wlock_acquire(rtld_bind_lock, &lockstate); 2575 dbg("rtld_exit()"); 2576 objlist_call_fini(&list_fini, NULL, &lockstate); 2577 /* No need to remove the items from the list, since we are exiting. */ 2578 if (!libmap_disable) 2579 lm_fini(); 2580 lock_release(rtld_bind_lock, &lockstate); 2581 } 2582 2583 static void * 2584 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2585 { 2586 #ifdef COMPAT_32BIT 2587 const char *trans; 2588 #endif 2589 if (path == NULL) 2590 return (NULL); 2591 2592 path += strspn(path, ":;"); 2593 while (*path != '\0') { 2594 size_t len; 2595 char *res; 2596 2597 len = strcspn(path, ":;"); 2598 #ifdef COMPAT_32BIT 2599 trans = lm_findn(NULL, path, len); 2600 if (trans) 2601 res = callback(trans, strlen(trans), arg); 2602 else 2603 #endif 2604 res = callback(path, len, arg); 2605 2606 if (res != NULL) 2607 return (res); 2608 2609 path += len; 2610 path += strspn(path, ":;"); 2611 } 2612 2613 return (NULL); 2614 } 2615 2616 struct try_library_args { 2617 const char *name; 2618 size_t namelen; 2619 char *buffer; 2620 size_t buflen; 2621 }; 2622 2623 static void * 2624 try_library_path(const char *dir, size_t dirlen, void *param) 2625 { 2626 struct try_library_args *arg; 2627 2628 arg = param; 2629 if (*dir == '/' || trust) { 2630 char *pathname; 2631 2632 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2633 return (NULL); 2634 2635 pathname = arg->buffer; 2636 strncpy(pathname, dir, dirlen); 2637 pathname[dirlen] = '/'; 2638 strcpy(pathname + dirlen + 1, arg->name); 2639 2640 dbg(" Trying \"%s\"", pathname); 2641 if (access(pathname, F_OK) == 0) { /* We found it */ 2642 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2643 strcpy(pathname, arg->buffer); 2644 return (pathname); 2645 } 2646 } 2647 return (NULL); 2648 } 2649 2650 static char * 2651 search_library_path(const char *name, const char *path) 2652 { 2653 char *p; 2654 struct try_library_args arg; 2655 2656 if (path == NULL) 2657 return NULL; 2658 2659 arg.name = name; 2660 arg.namelen = strlen(name); 2661 arg.buffer = xmalloc(PATH_MAX); 2662 arg.buflen = PATH_MAX; 2663 2664 p = path_enumerate(path, try_library_path, &arg); 2665 2666 free(arg.buffer); 2667 2668 return (p); 2669 } 2670 2671 int 2672 dlclose(void *handle) 2673 { 2674 Obj_Entry *root; 2675 RtldLockState lockstate; 2676 2677 wlock_acquire(rtld_bind_lock, &lockstate); 2678 root = dlcheck(handle); 2679 if (root == NULL) { 2680 lock_release(rtld_bind_lock, &lockstate); 2681 return -1; 2682 } 2683 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2684 root->path); 2685 2686 /* Unreference the object and its dependencies. */ 2687 root->dl_refcount--; 2688 2689 if (root->refcount == 1) { 2690 /* 2691 * The object will be no longer referenced, so we must unload it. 2692 * First, call the fini functions. 2693 */ 2694 objlist_call_fini(&list_fini, root, &lockstate); 2695 2696 unref_dag(root); 2697 2698 /* Finish cleaning up the newly-unreferenced objects. */ 2699 GDB_STATE(RT_DELETE,&root->linkmap); 2700 unload_object(root); 2701 GDB_STATE(RT_CONSISTENT,NULL); 2702 } else 2703 unref_dag(root); 2704 2705 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2706 lock_release(rtld_bind_lock, &lockstate); 2707 return 0; 2708 } 2709 2710 char * 2711 dlerror(void) 2712 { 2713 char *msg = error_message; 2714 error_message = NULL; 2715 return msg; 2716 } 2717 2718 /* 2719 * This function is deprecated and has no effect. 2720 */ 2721 void 2722 dllockinit(void *context, 2723 void *(*lock_create)(void *context), 2724 void (*rlock_acquire)(void *lock), 2725 void (*wlock_acquire)(void *lock), 2726 void (*lock_release)(void *lock), 2727 void (*lock_destroy)(void *lock), 2728 void (*context_destroy)(void *context)) 2729 { 2730 static void *cur_context; 2731 static void (*cur_context_destroy)(void *); 2732 2733 /* Just destroy the context from the previous call, if necessary. */ 2734 if (cur_context_destroy != NULL) 2735 cur_context_destroy(cur_context); 2736 cur_context = context; 2737 cur_context_destroy = context_destroy; 2738 } 2739 2740 void * 2741 dlopen(const char *name, int mode) 2742 { 2743 2744 return (rtld_dlopen(name, -1, mode)); 2745 } 2746 2747 void * 2748 fdlopen(int fd, int mode) 2749 { 2750 2751 return (rtld_dlopen(NULL, fd, mode)); 2752 } 2753 2754 static void * 2755 rtld_dlopen(const char *name, int fd, int mode) 2756 { 2757 RtldLockState lockstate; 2758 int lo_flags; 2759 2760 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2761 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2762 if (ld_tracing != NULL) { 2763 rlock_acquire(rtld_bind_lock, &lockstate); 2764 if (sigsetjmp(lockstate.env, 0) != 0) 2765 lock_upgrade(rtld_bind_lock, &lockstate); 2766 environ = (char **)*get_program_var_addr("environ", &lockstate); 2767 lock_release(rtld_bind_lock, &lockstate); 2768 } 2769 lo_flags = RTLD_LO_DLOPEN; 2770 if (mode & RTLD_NODELETE) 2771 lo_flags |= RTLD_LO_NODELETE; 2772 if (mode & RTLD_NOLOAD) 2773 lo_flags |= RTLD_LO_NOLOAD; 2774 if (ld_tracing != NULL) 2775 lo_flags |= RTLD_LO_TRACE; 2776 2777 return (dlopen_object(name, fd, obj_main, lo_flags, 2778 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2779 } 2780 2781 static void 2782 dlopen_cleanup(Obj_Entry *obj) 2783 { 2784 2785 obj->dl_refcount--; 2786 unref_dag(obj); 2787 if (obj->refcount == 0) 2788 unload_object(obj); 2789 } 2790 2791 static Obj_Entry * 2792 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2793 int mode, RtldLockState *lockstate) 2794 { 2795 Obj_Entry **old_obj_tail; 2796 Obj_Entry *obj; 2797 Objlist initlist; 2798 RtldLockState mlockstate; 2799 int result; 2800 2801 objlist_init(&initlist); 2802 2803 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2804 wlock_acquire(rtld_bind_lock, &mlockstate); 2805 lockstate = &mlockstate; 2806 } 2807 GDB_STATE(RT_ADD,NULL); 2808 2809 old_obj_tail = obj_tail; 2810 obj = NULL; 2811 if (name == NULL && fd == -1) { 2812 obj = obj_main; 2813 obj->refcount++; 2814 } else { 2815 obj = load_object(name, fd, refobj, lo_flags); 2816 } 2817 2818 if (obj) { 2819 obj->dl_refcount++; 2820 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2821 objlist_push_tail(&list_global, obj); 2822 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2823 assert(*old_obj_tail == obj); 2824 result = load_needed_objects(obj, 2825 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2826 init_dag(obj); 2827 ref_dag(obj); 2828 if (result != -1) 2829 result = rtld_verify_versions(&obj->dagmembers); 2830 if (result != -1 && ld_tracing) 2831 goto trace; 2832 if (result == -1 || relocate_object_dag(obj, 2833 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2834 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2835 lockstate) == -1) { 2836 dlopen_cleanup(obj); 2837 obj = NULL; 2838 } else if (lo_flags & RTLD_LO_EARLY) { 2839 /* 2840 * Do not call the init functions for early loaded 2841 * filtees. The image is still not initialized enough 2842 * for them to work. 2843 * 2844 * Our object is found by the global object list and 2845 * will be ordered among all init calls done right 2846 * before transferring control to main. 2847 */ 2848 } else { 2849 /* Make list of init functions to call. */ 2850 initlist_add_objects(obj, &obj->next, &initlist); 2851 } 2852 /* 2853 * Process all no_delete objects here, given them own 2854 * DAGs to prevent their dependencies from being unloaded. 2855 * This has to be done after we have loaded all of the 2856 * dependencies, so that we do not miss any. 2857 */ 2858 if (obj != NULL) 2859 process_nodelete(obj); 2860 } else { 2861 /* 2862 * Bump the reference counts for objects on this DAG. If 2863 * this is the first dlopen() call for the object that was 2864 * already loaded as a dependency, initialize the dag 2865 * starting at it. 2866 */ 2867 init_dag(obj); 2868 ref_dag(obj); 2869 2870 if ((lo_flags & RTLD_LO_TRACE) != 0) 2871 goto trace; 2872 } 2873 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2874 obj->z_nodelete) && !obj->ref_nodel) { 2875 dbg("obj %s nodelete", obj->path); 2876 ref_dag(obj); 2877 obj->z_nodelete = obj->ref_nodel = true; 2878 } 2879 } 2880 2881 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2882 name); 2883 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2884 2885 if (!(lo_flags & RTLD_LO_EARLY)) { 2886 map_stacks_exec(lockstate); 2887 } 2888 2889 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2890 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2891 lockstate) == -1) { 2892 objlist_clear(&initlist); 2893 dlopen_cleanup(obj); 2894 if (lockstate == &mlockstate) 2895 lock_release(rtld_bind_lock, lockstate); 2896 return (NULL); 2897 } 2898 2899 if (!(lo_flags & RTLD_LO_EARLY)) { 2900 /* Call the init functions. */ 2901 objlist_call_init(&initlist, lockstate); 2902 } 2903 objlist_clear(&initlist); 2904 if (lockstate == &mlockstate) 2905 lock_release(rtld_bind_lock, lockstate); 2906 return obj; 2907 trace: 2908 trace_loaded_objects(obj); 2909 if (lockstate == &mlockstate) 2910 lock_release(rtld_bind_lock, lockstate); 2911 exit(0); 2912 } 2913 2914 static void * 2915 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2916 int flags) 2917 { 2918 DoneList donelist; 2919 const Obj_Entry *obj, *defobj; 2920 const Elf_Sym *def; 2921 SymLook req; 2922 RtldLockState lockstate; 2923 #ifndef __ia64__ 2924 tls_index ti; 2925 #endif 2926 int res; 2927 2928 def = NULL; 2929 defobj = NULL; 2930 symlook_init(&req, name); 2931 req.ventry = ve; 2932 req.flags = flags | SYMLOOK_IN_PLT; 2933 req.lockstate = &lockstate; 2934 2935 rlock_acquire(rtld_bind_lock, &lockstate); 2936 if (sigsetjmp(lockstate.env, 0) != 0) 2937 lock_upgrade(rtld_bind_lock, &lockstate); 2938 if (handle == NULL || handle == RTLD_NEXT || 2939 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2940 2941 if ((obj = obj_from_addr(retaddr)) == NULL) { 2942 _rtld_error("Cannot determine caller's shared object"); 2943 lock_release(rtld_bind_lock, &lockstate); 2944 return NULL; 2945 } 2946 if (handle == NULL) { /* Just the caller's shared object. */ 2947 res = symlook_obj(&req, obj); 2948 if (res == 0) { 2949 def = req.sym_out; 2950 defobj = req.defobj_out; 2951 } 2952 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2953 handle == RTLD_SELF) { /* ... caller included */ 2954 if (handle == RTLD_NEXT) 2955 obj = obj->next; 2956 for (; obj != NULL; obj = obj->next) { 2957 res = symlook_obj(&req, obj); 2958 if (res == 0) { 2959 if (def == NULL || 2960 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2961 def = req.sym_out; 2962 defobj = req.defobj_out; 2963 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2964 break; 2965 } 2966 } 2967 } 2968 /* 2969 * Search the dynamic linker itself, and possibly resolve the 2970 * symbol from there. This is how the application links to 2971 * dynamic linker services such as dlopen. 2972 */ 2973 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2974 res = symlook_obj(&req, &obj_rtld); 2975 if (res == 0) { 2976 def = req.sym_out; 2977 defobj = req.defobj_out; 2978 } 2979 } 2980 } else { 2981 assert(handle == RTLD_DEFAULT); 2982 res = symlook_default(&req, obj); 2983 if (res == 0) { 2984 defobj = req.defobj_out; 2985 def = req.sym_out; 2986 } 2987 } 2988 } else { 2989 if ((obj = dlcheck(handle)) == NULL) { 2990 lock_release(rtld_bind_lock, &lockstate); 2991 return NULL; 2992 } 2993 2994 donelist_init(&donelist); 2995 if (obj->mainprog) { 2996 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 2997 res = symlook_global(&req, &donelist); 2998 if (res == 0) { 2999 def = req.sym_out; 3000 defobj = req.defobj_out; 3001 } 3002 /* 3003 * Search the dynamic linker itself, and possibly resolve the 3004 * symbol from there. This is how the application links to 3005 * dynamic linker services such as dlopen. 3006 */ 3007 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3008 res = symlook_obj(&req, &obj_rtld); 3009 if (res == 0) { 3010 def = req.sym_out; 3011 defobj = req.defobj_out; 3012 } 3013 } 3014 } 3015 else { 3016 /* Search the whole DAG rooted at the given object. */ 3017 res = symlook_list(&req, &obj->dagmembers, &donelist); 3018 if (res == 0) { 3019 def = req.sym_out; 3020 defobj = req.defobj_out; 3021 } 3022 } 3023 } 3024 3025 if (def != NULL) { 3026 lock_release(rtld_bind_lock, &lockstate); 3027 3028 /* 3029 * The value required by the caller is derived from the value 3030 * of the symbol. For the ia64 architecture, we need to 3031 * construct a function descriptor which the caller can use to 3032 * call the function with the right 'gp' value. For other 3033 * architectures and for non-functions, the value is simply 3034 * the relocated value of the symbol. 3035 */ 3036 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3037 return (make_function_pointer(def, defobj)); 3038 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3039 return (rtld_resolve_ifunc(defobj, def)); 3040 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3041 #ifdef __ia64__ 3042 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3043 #else 3044 ti.ti_module = defobj->tlsindex; 3045 ti.ti_offset = def->st_value; 3046 return (__tls_get_addr(&ti)); 3047 #endif 3048 } else 3049 return (defobj->relocbase + def->st_value); 3050 } 3051 3052 _rtld_error("Undefined symbol \"%s\"", name); 3053 lock_release(rtld_bind_lock, &lockstate); 3054 return NULL; 3055 } 3056 3057 void * 3058 dlsym(void *handle, const char *name) 3059 { 3060 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3061 SYMLOOK_DLSYM); 3062 } 3063 3064 dlfunc_t 3065 dlfunc(void *handle, const char *name) 3066 { 3067 union { 3068 void *d; 3069 dlfunc_t f; 3070 } rv; 3071 3072 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3073 SYMLOOK_DLSYM); 3074 return (rv.f); 3075 } 3076 3077 void * 3078 dlvsym(void *handle, const char *name, const char *version) 3079 { 3080 Ver_Entry ventry; 3081 3082 ventry.name = version; 3083 ventry.file = NULL; 3084 ventry.hash = elf_hash(version); 3085 ventry.flags= 0; 3086 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3087 SYMLOOK_DLSYM); 3088 } 3089 3090 int 3091 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3092 { 3093 const Obj_Entry *obj; 3094 RtldLockState lockstate; 3095 3096 rlock_acquire(rtld_bind_lock, &lockstate); 3097 obj = obj_from_addr(addr); 3098 if (obj == NULL) { 3099 _rtld_error("No shared object contains address"); 3100 lock_release(rtld_bind_lock, &lockstate); 3101 return (0); 3102 } 3103 rtld_fill_dl_phdr_info(obj, phdr_info); 3104 lock_release(rtld_bind_lock, &lockstate); 3105 return (1); 3106 } 3107 3108 int 3109 dladdr(const void *addr, Dl_info *info) 3110 { 3111 const Obj_Entry *obj; 3112 const Elf_Sym *def; 3113 void *symbol_addr; 3114 unsigned long symoffset; 3115 RtldLockState lockstate; 3116 3117 rlock_acquire(rtld_bind_lock, &lockstate); 3118 obj = obj_from_addr(addr); 3119 if (obj == NULL) { 3120 _rtld_error("No shared object contains address"); 3121 lock_release(rtld_bind_lock, &lockstate); 3122 return 0; 3123 } 3124 info->dli_fname = obj->path; 3125 info->dli_fbase = obj->mapbase; 3126 info->dli_saddr = (void *)0; 3127 info->dli_sname = NULL; 3128 3129 /* 3130 * Walk the symbol list looking for the symbol whose address is 3131 * closest to the address sent in. 3132 */ 3133 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3134 def = obj->symtab + symoffset; 3135 3136 /* 3137 * For skip the symbol if st_shndx is either SHN_UNDEF or 3138 * SHN_COMMON. 3139 */ 3140 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3141 continue; 3142 3143 /* 3144 * If the symbol is greater than the specified address, or if it 3145 * is further away from addr than the current nearest symbol, 3146 * then reject it. 3147 */ 3148 symbol_addr = obj->relocbase + def->st_value; 3149 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3150 continue; 3151 3152 /* Update our idea of the nearest symbol. */ 3153 info->dli_sname = obj->strtab + def->st_name; 3154 info->dli_saddr = symbol_addr; 3155 3156 /* Exact match? */ 3157 if (info->dli_saddr == addr) 3158 break; 3159 } 3160 lock_release(rtld_bind_lock, &lockstate); 3161 return 1; 3162 } 3163 3164 int 3165 dlinfo(void *handle, int request, void *p) 3166 { 3167 const Obj_Entry *obj; 3168 RtldLockState lockstate; 3169 int error; 3170 3171 rlock_acquire(rtld_bind_lock, &lockstate); 3172 3173 if (handle == NULL || handle == RTLD_SELF) { 3174 void *retaddr; 3175 3176 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3177 if ((obj = obj_from_addr(retaddr)) == NULL) 3178 _rtld_error("Cannot determine caller's shared object"); 3179 } else 3180 obj = dlcheck(handle); 3181 3182 if (obj == NULL) { 3183 lock_release(rtld_bind_lock, &lockstate); 3184 return (-1); 3185 } 3186 3187 error = 0; 3188 switch (request) { 3189 case RTLD_DI_LINKMAP: 3190 *((struct link_map const **)p) = &obj->linkmap; 3191 break; 3192 case RTLD_DI_ORIGIN: 3193 error = rtld_dirname(obj->path, p); 3194 break; 3195 3196 case RTLD_DI_SERINFOSIZE: 3197 case RTLD_DI_SERINFO: 3198 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3199 break; 3200 3201 default: 3202 _rtld_error("Invalid request %d passed to dlinfo()", request); 3203 error = -1; 3204 } 3205 3206 lock_release(rtld_bind_lock, &lockstate); 3207 3208 return (error); 3209 } 3210 3211 static void 3212 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3213 { 3214 3215 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3216 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 3217 STAILQ_FIRST(&obj->names)->name : obj->path; 3218 phdr_info->dlpi_phdr = obj->phdr; 3219 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3220 phdr_info->dlpi_tls_modid = obj->tlsindex; 3221 phdr_info->dlpi_tls_data = obj->tlsinit; 3222 phdr_info->dlpi_adds = obj_loads; 3223 phdr_info->dlpi_subs = obj_loads - obj_count; 3224 } 3225 3226 int 3227 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3228 { 3229 struct dl_phdr_info phdr_info; 3230 const Obj_Entry *obj; 3231 RtldLockState bind_lockstate, phdr_lockstate; 3232 int error; 3233 3234 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3235 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3236 3237 error = 0; 3238 3239 for (obj = obj_list; obj != NULL; obj = obj->next) { 3240 rtld_fill_dl_phdr_info(obj, &phdr_info); 3241 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3242 break; 3243 3244 } 3245 lock_release(rtld_bind_lock, &bind_lockstate); 3246 lock_release(rtld_phdr_lock, &phdr_lockstate); 3247 3248 return (error); 3249 } 3250 3251 static void * 3252 fill_search_info(const char *dir, size_t dirlen, void *param) 3253 { 3254 struct fill_search_info_args *arg; 3255 3256 arg = param; 3257 3258 if (arg->request == RTLD_DI_SERINFOSIZE) { 3259 arg->serinfo->dls_cnt ++; 3260 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3261 } else { 3262 struct dl_serpath *s_entry; 3263 3264 s_entry = arg->serpath; 3265 s_entry->dls_name = arg->strspace; 3266 s_entry->dls_flags = arg->flags; 3267 3268 strncpy(arg->strspace, dir, dirlen); 3269 arg->strspace[dirlen] = '\0'; 3270 3271 arg->strspace += dirlen + 1; 3272 arg->serpath++; 3273 } 3274 3275 return (NULL); 3276 } 3277 3278 static int 3279 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3280 { 3281 struct dl_serinfo _info; 3282 struct fill_search_info_args args; 3283 3284 args.request = RTLD_DI_SERINFOSIZE; 3285 args.serinfo = &_info; 3286 3287 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3288 _info.dls_cnt = 0; 3289 3290 path_enumerate(obj->rpath, fill_search_info, &args); 3291 path_enumerate(ld_library_path, fill_search_info, &args); 3292 path_enumerate(obj->runpath, fill_search_info, &args); 3293 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3294 if (!obj->z_nodeflib) 3295 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3296 3297 3298 if (request == RTLD_DI_SERINFOSIZE) { 3299 info->dls_size = _info.dls_size; 3300 info->dls_cnt = _info.dls_cnt; 3301 return (0); 3302 } 3303 3304 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3305 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3306 return (-1); 3307 } 3308 3309 args.request = RTLD_DI_SERINFO; 3310 args.serinfo = info; 3311 args.serpath = &info->dls_serpath[0]; 3312 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3313 3314 args.flags = LA_SER_RUNPATH; 3315 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3316 return (-1); 3317 3318 args.flags = LA_SER_LIBPATH; 3319 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3320 return (-1); 3321 3322 args.flags = LA_SER_RUNPATH; 3323 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3324 return (-1); 3325 3326 args.flags = LA_SER_CONFIG; 3327 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3328 != NULL) 3329 return (-1); 3330 3331 args.flags = LA_SER_DEFAULT; 3332 if (!obj->z_nodeflib && 3333 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3334 return (-1); 3335 return (0); 3336 } 3337 3338 static int 3339 rtld_dirname(const char *path, char *bname) 3340 { 3341 const char *endp; 3342 3343 /* Empty or NULL string gets treated as "." */ 3344 if (path == NULL || *path == '\0') { 3345 bname[0] = '.'; 3346 bname[1] = '\0'; 3347 return (0); 3348 } 3349 3350 /* Strip trailing slashes */ 3351 endp = path + strlen(path) - 1; 3352 while (endp > path && *endp == '/') 3353 endp--; 3354 3355 /* Find the start of the dir */ 3356 while (endp > path && *endp != '/') 3357 endp--; 3358 3359 /* Either the dir is "/" or there are no slashes */ 3360 if (endp == path) { 3361 bname[0] = *endp == '/' ? '/' : '.'; 3362 bname[1] = '\0'; 3363 return (0); 3364 } else { 3365 do { 3366 endp--; 3367 } while (endp > path && *endp == '/'); 3368 } 3369 3370 if (endp - path + 2 > PATH_MAX) 3371 { 3372 _rtld_error("Filename is too long: %s", path); 3373 return(-1); 3374 } 3375 3376 strncpy(bname, path, endp - path + 1); 3377 bname[endp - path + 1] = '\0'; 3378 return (0); 3379 } 3380 3381 static int 3382 rtld_dirname_abs(const char *path, char *base) 3383 { 3384 char base_rel[PATH_MAX]; 3385 3386 if (rtld_dirname(path, base) == -1) 3387 return (-1); 3388 if (base[0] == '/') 3389 return (0); 3390 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3391 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3392 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3393 return (-1); 3394 strcpy(base, base_rel); 3395 return (0); 3396 } 3397 3398 static void 3399 linkmap_add(Obj_Entry *obj) 3400 { 3401 struct link_map *l = &obj->linkmap; 3402 struct link_map *prev; 3403 3404 obj->linkmap.l_name = obj->path; 3405 obj->linkmap.l_addr = obj->mapbase; 3406 obj->linkmap.l_ld = obj->dynamic; 3407 #ifdef __mips__ 3408 /* GDB needs load offset on MIPS to use the symbols */ 3409 obj->linkmap.l_offs = obj->relocbase; 3410 #endif 3411 3412 if (r_debug.r_map == NULL) { 3413 r_debug.r_map = l; 3414 return; 3415 } 3416 3417 /* 3418 * Scan to the end of the list, but not past the entry for the 3419 * dynamic linker, which we want to keep at the very end. 3420 */ 3421 for (prev = r_debug.r_map; 3422 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3423 prev = prev->l_next) 3424 ; 3425 3426 /* Link in the new entry. */ 3427 l->l_prev = prev; 3428 l->l_next = prev->l_next; 3429 if (l->l_next != NULL) 3430 l->l_next->l_prev = l; 3431 prev->l_next = l; 3432 } 3433 3434 static void 3435 linkmap_delete(Obj_Entry *obj) 3436 { 3437 struct link_map *l = &obj->linkmap; 3438 3439 if (l->l_prev == NULL) { 3440 if ((r_debug.r_map = l->l_next) != NULL) 3441 l->l_next->l_prev = NULL; 3442 return; 3443 } 3444 3445 if ((l->l_prev->l_next = l->l_next) != NULL) 3446 l->l_next->l_prev = l->l_prev; 3447 } 3448 3449 /* 3450 * Function for the debugger to set a breakpoint on to gain control. 3451 * 3452 * The two parameters allow the debugger to easily find and determine 3453 * what the runtime loader is doing and to whom it is doing it. 3454 * 3455 * When the loadhook trap is hit (r_debug_state, set at program 3456 * initialization), the arguments can be found on the stack: 3457 * 3458 * +8 struct link_map *m 3459 * +4 struct r_debug *rd 3460 * +0 RetAddr 3461 */ 3462 void 3463 r_debug_state(struct r_debug* rd, struct link_map *m) 3464 { 3465 /* 3466 * The following is a hack to force the compiler to emit calls to 3467 * this function, even when optimizing. If the function is empty, 3468 * the compiler is not obliged to emit any code for calls to it, 3469 * even when marked __noinline. However, gdb depends on those 3470 * calls being made. 3471 */ 3472 __asm __volatile("" : : : "memory"); 3473 } 3474 3475 /* 3476 * Get address of the pointer variable in the main program. 3477 * Prefer non-weak symbol over the weak one. 3478 */ 3479 static const void ** 3480 get_program_var_addr(const char *name, RtldLockState *lockstate) 3481 { 3482 SymLook req; 3483 DoneList donelist; 3484 3485 symlook_init(&req, name); 3486 req.lockstate = lockstate; 3487 donelist_init(&donelist); 3488 if (symlook_global(&req, &donelist) != 0) 3489 return (NULL); 3490 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3491 return ((const void **)make_function_pointer(req.sym_out, 3492 req.defobj_out)); 3493 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3494 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3495 else 3496 return ((const void **)(req.defobj_out->relocbase + 3497 req.sym_out->st_value)); 3498 } 3499 3500 /* 3501 * Set a pointer variable in the main program to the given value. This 3502 * is used to set key variables such as "environ" before any of the 3503 * init functions are called. 3504 */ 3505 static void 3506 set_program_var(const char *name, const void *value) 3507 { 3508 const void **addr; 3509 3510 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3511 dbg("\"%s\": *%p <-- %p", name, addr, value); 3512 *addr = value; 3513 } 3514 } 3515 3516 /* 3517 * Search the global objects, including dependencies and main object, 3518 * for the given symbol. 3519 */ 3520 static int 3521 symlook_global(SymLook *req, DoneList *donelist) 3522 { 3523 SymLook req1; 3524 const Objlist_Entry *elm; 3525 int res; 3526 3527 symlook_init_from_req(&req1, req); 3528 3529 /* Search all objects loaded at program start up. */ 3530 if (req->defobj_out == NULL || 3531 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3532 res = symlook_list(&req1, &list_main, donelist); 3533 if (res == 0 && (req->defobj_out == NULL || 3534 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3535 req->sym_out = req1.sym_out; 3536 req->defobj_out = req1.defobj_out; 3537 assert(req->defobj_out != NULL); 3538 } 3539 } 3540 3541 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3542 STAILQ_FOREACH(elm, &list_global, link) { 3543 if (req->defobj_out != NULL && 3544 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3545 break; 3546 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3547 if (res == 0 && (req->defobj_out == NULL || 3548 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3549 req->sym_out = req1.sym_out; 3550 req->defobj_out = req1.defobj_out; 3551 assert(req->defobj_out != NULL); 3552 } 3553 } 3554 3555 return (req->sym_out != NULL ? 0 : ESRCH); 3556 } 3557 3558 /* 3559 * Given a symbol name in a referencing object, find the corresponding 3560 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3561 * no definition was found. Returns a pointer to the Obj_Entry of the 3562 * defining object via the reference parameter DEFOBJ_OUT. 3563 */ 3564 static int 3565 symlook_default(SymLook *req, const Obj_Entry *refobj) 3566 { 3567 DoneList donelist; 3568 const Objlist_Entry *elm; 3569 SymLook req1; 3570 int res; 3571 3572 donelist_init(&donelist); 3573 symlook_init_from_req(&req1, req); 3574 3575 /* Look first in the referencing object if linked symbolically. */ 3576 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3577 res = symlook_obj(&req1, refobj); 3578 if (res == 0) { 3579 req->sym_out = req1.sym_out; 3580 req->defobj_out = req1.defobj_out; 3581 assert(req->defobj_out != NULL); 3582 } 3583 } 3584 3585 symlook_global(req, &donelist); 3586 3587 /* Search all dlopened DAGs containing the referencing object. */ 3588 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3589 if (req->sym_out != NULL && 3590 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3591 break; 3592 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3593 if (res == 0 && (req->sym_out == NULL || 3594 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3595 req->sym_out = req1.sym_out; 3596 req->defobj_out = req1.defobj_out; 3597 assert(req->defobj_out != NULL); 3598 } 3599 } 3600 3601 /* 3602 * Search the dynamic linker itself, and possibly resolve the 3603 * symbol from there. This is how the application links to 3604 * dynamic linker services such as dlopen. 3605 */ 3606 if (req->sym_out == NULL || 3607 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3608 res = symlook_obj(&req1, &obj_rtld); 3609 if (res == 0) { 3610 req->sym_out = req1.sym_out; 3611 req->defobj_out = req1.defobj_out; 3612 assert(req->defobj_out != NULL); 3613 } 3614 } 3615 3616 return (req->sym_out != NULL ? 0 : ESRCH); 3617 } 3618 3619 static int 3620 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3621 { 3622 const Elf_Sym *def; 3623 const Obj_Entry *defobj; 3624 const Objlist_Entry *elm; 3625 SymLook req1; 3626 int res; 3627 3628 def = NULL; 3629 defobj = NULL; 3630 STAILQ_FOREACH(elm, objlist, link) { 3631 if (donelist_check(dlp, elm->obj)) 3632 continue; 3633 symlook_init_from_req(&req1, req); 3634 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3635 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3636 def = req1.sym_out; 3637 defobj = req1.defobj_out; 3638 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3639 break; 3640 } 3641 } 3642 } 3643 if (def != NULL) { 3644 req->sym_out = def; 3645 req->defobj_out = defobj; 3646 return (0); 3647 } 3648 return (ESRCH); 3649 } 3650 3651 /* 3652 * Search the chain of DAGS cointed to by the given Needed_Entry 3653 * for a symbol of the given name. Each DAG is scanned completely 3654 * before advancing to the next one. Returns a pointer to the symbol, 3655 * or NULL if no definition was found. 3656 */ 3657 static int 3658 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3659 { 3660 const Elf_Sym *def; 3661 const Needed_Entry *n; 3662 const Obj_Entry *defobj; 3663 SymLook req1; 3664 int res; 3665 3666 def = NULL; 3667 defobj = NULL; 3668 symlook_init_from_req(&req1, req); 3669 for (n = needed; n != NULL; n = n->next) { 3670 if (n->obj == NULL || 3671 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3672 continue; 3673 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3674 def = req1.sym_out; 3675 defobj = req1.defobj_out; 3676 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3677 break; 3678 } 3679 } 3680 if (def != NULL) { 3681 req->sym_out = def; 3682 req->defobj_out = defobj; 3683 return (0); 3684 } 3685 return (ESRCH); 3686 } 3687 3688 /* 3689 * Search the symbol table of a single shared object for a symbol of 3690 * the given name and version, if requested. Returns a pointer to the 3691 * symbol, or NULL if no definition was found. If the object is 3692 * filter, return filtered symbol from filtee. 3693 * 3694 * The symbol's hash value is passed in for efficiency reasons; that 3695 * eliminates many recomputations of the hash value. 3696 */ 3697 int 3698 symlook_obj(SymLook *req, const Obj_Entry *obj) 3699 { 3700 DoneList donelist; 3701 SymLook req1; 3702 int flags, res, mres; 3703 3704 /* 3705 * If there is at least one valid hash at this point, we prefer to 3706 * use the faster GNU version if available. 3707 */ 3708 if (obj->valid_hash_gnu) 3709 mres = symlook_obj1_gnu(req, obj); 3710 else if (obj->valid_hash_sysv) 3711 mres = symlook_obj1_sysv(req, obj); 3712 else 3713 return (EINVAL); 3714 3715 if (mres == 0) { 3716 if (obj->needed_filtees != NULL) { 3717 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3718 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3719 donelist_init(&donelist); 3720 symlook_init_from_req(&req1, req); 3721 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3722 if (res == 0) { 3723 req->sym_out = req1.sym_out; 3724 req->defobj_out = req1.defobj_out; 3725 } 3726 return (res); 3727 } 3728 if (obj->needed_aux_filtees != NULL) { 3729 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3730 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3731 donelist_init(&donelist); 3732 symlook_init_from_req(&req1, req); 3733 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3734 if (res == 0) { 3735 req->sym_out = req1.sym_out; 3736 req->defobj_out = req1.defobj_out; 3737 return (res); 3738 } 3739 } 3740 } 3741 return (mres); 3742 } 3743 3744 /* Symbol match routine common to both hash functions */ 3745 static bool 3746 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3747 const unsigned long symnum) 3748 { 3749 Elf_Versym verndx; 3750 const Elf_Sym *symp; 3751 const char *strp; 3752 3753 symp = obj->symtab + symnum; 3754 strp = obj->strtab + symp->st_name; 3755 3756 switch (ELF_ST_TYPE(symp->st_info)) { 3757 case STT_FUNC: 3758 case STT_NOTYPE: 3759 case STT_OBJECT: 3760 case STT_COMMON: 3761 case STT_GNU_IFUNC: 3762 if (symp->st_value == 0) 3763 return (false); 3764 /* fallthrough */ 3765 case STT_TLS: 3766 if (symp->st_shndx != SHN_UNDEF) 3767 break; 3768 #ifndef __mips__ 3769 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3770 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3771 break; 3772 /* fallthrough */ 3773 #endif 3774 default: 3775 return (false); 3776 } 3777 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3778 return (false); 3779 3780 if (req->ventry == NULL) { 3781 if (obj->versyms != NULL) { 3782 verndx = VER_NDX(obj->versyms[symnum]); 3783 if (verndx > obj->vernum) { 3784 _rtld_error( 3785 "%s: symbol %s references wrong version %d", 3786 obj->path, obj->strtab + symnum, verndx); 3787 return (false); 3788 } 3789 /* 3790 * If we are not called from dlsym (i.e. this 3791 * is a normal relocation from unversioned 3792 * binary), accept the symbol immediately if 3793 * it happens to have first version after this 3794 * shared object became versioned. Otherwise, 3795 * if symbol is versioned and not hidden, 3796 * remember it. If it is the only symbol with 3797 * this name exported by the shared object, it 3798 * will be returned as a match by the calling 3799 * function. If symbol is global (verndx < 2) 3800 * accept it unconditionally. 3801 */ 3802 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3803 verndx == VER_NDX_GIVEN) { 3804 result->sym_out = symp; 3805 return (true); 3806 } 3807 else if (verndx >= VER_NDX_GIVEN) { 3808 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3809 == 0) { 3810 if (result->vsymp == NULL) 3811 result->vsymp = symp; 3812 result->vcount++; 3813 } 3814 return (false); 3815 } 3816 } 3817 result->sym_out = symp; 3818 return (true); 3819 } 3820 if (obj->versyms == NULL) { 3821 if (object_match_name(obj, req->ventry->name)) { 3822 _rtld_error("%s: object %s should provide version %s " 3823 "for symbol %s", obj_rtld.path, obj->path, 3824 req->ventry->name, obj->strtab + symnum); 3825 return (false); 3826 } 3827 } else { 3828 verndx = VER_NDX(obj->versyms[symnum]); 3829 if (verndx > obj->vernum) { 3830 _rtld_error("%s: symbol %s references wrong version %d", 3831 obj->path, obj->strtab + symnum, verndx); 3832 return (false); 3833 } 3834 if (obj->vertab[verndx].hash != req->ventry->hash || 3835 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3836 /* 3837 * Version does not match. Look if this is a 3838 * global symbol and if it is not hidden. If 3839 * global symbol (verndx < 2) is available, 3840 * use it. Do not return symbol if we are 3841 * called by dlvsym, because dlvsym looks for 3842 * a specific version and default one is not 3843 * what dlvsym wants. 3844 */ 3845 if ((req->flags & SYMLOOK_DLSYM) || 3846 (verndx >= VER_NDX_GIVEN) || 3847 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3848 return (false); 3849 } 3850 } 3851 result->sym_out = symp; 3852 return (true); 3853 } 3854 3855 /* 3856 * Search for symbol using SysV hash function. 3857 * obj->buckets is known not to be NULL at this point; the test for this was 3858 * performed with the obj->valid_hash_sysv assignment. 3859 */ 3860 static int 3861 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3862 { 3863 unsigned long symnum; 3864 Sym_Match_Result matchres; 3865 3866 matchres.sym_out = NULL; 3867 matchres.vsymp = NULL; 3868 matchres.vcount = 0; 3869 3870 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3871 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3872 if (symnum >= obj->nchains) 3873 return (ESRCH); /* Bad object */ 3874 3875 if (matched_symbol(req, obj, &matchres, symnum)) { 3876 req->sym_out = matchres.sym_out; 3877 req->defobj_out = obj; 3878 return (0); 3879 } 3880 } 3881 if (matchres.vcount == 1) { 3882 req->sym_out = matchres.vsymp; 3883 req->defobj_out = obj; 3884 return (0); 3885 } 3886 return (ESRCH); 3887 } 3888 3889 /* Search for symbol using GNU hash function */ 3890 static int 3891 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3892 { 3893 Elf_Addr bloom_word; 3894 const Elf32_Word *hashval; 3895 Elf32_Word bucket; 3896 Sym_Match_Result matchres; 3897 unsigned int h1, h2; 3898 unsigned long symnum; 3899 3900 matchres.sym_out = NULL; 3901 matchres.vsymp = NULL; 3902 matchres.vcount = 0; 3903 3904 /* Pick right bitmask word from Bloom filter array */ 3905 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3906 obj->maskwords_bm_gnu]; 3907 3908 /* Calculate modulus word size of gnu hash and its derivative */ 3909 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3910 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3911 3912 /* Filter out the "definitely not in set" queries */ 3913 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3914 return (ESRCH); 3915 3916 /* Locate hash chain and corresponding value element*/ 3917 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3918 if (bucket == 0) 3919 return (ESRCH); 3920 hashval = &obj->chain_zero_gnu[bucket]; 3921 do { 3922 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3923 symnum = hashval - obj->chain_zero_gnu; 3924 if (matched_symbol(req, obj, &matchres, symnum)) { 3925 req->sym_out = matchres.sym_out; 3926 req->defobj_out = obj; 3927 return (0); 3928 } 3929 } 3930 } while ((*hashval++ & 1) == 0); 3931 if (matchres.vcount == 1) { 3932 req->sym_out = matchres.vsymp; 3933 req->defobj_out = obj; 3934 return (0); 3935 } 3936 return (ESRCH); 3937 } 3938 3939 static void 3940 trace_loaded_objects(Obj_Entry *obj) 3941 { 3942 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3943 int c; 3944 3945 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3946 main_local = ""; 3947 3948 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3949 fmt1 = "\t%o => %p (%x)\n"; 3950 3951 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3952 fmt2 = "\t%o (%x)\n"; 3953 3954 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3955 3956 for (; obj; obj = obj->next) { 3957 Needed_Entry *needed; 3958 char *name, *path; 3959 bool is_lib; 3960 3961 if (list_containers && obj->needed != NULL) 3962 rtld_printf("%s:\n", obj->path); 3963 for (needed = obj->needed; needed; needed = needed->next) { 3964 if (needed->obj != NULL) { 3965 if (needed->obj->traced && !list_containers) 3966 continue; 3967 needed->obj->traced = true; 3968 path = needed->obj->path; 3969 } else 3970 path = "not found"; 3971 3972 name = (char *)obj->strtab + needed->name; 3973 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 3974 3975 fmt = is_lib ? fmt1 : fmt2; 3976 while ((c = *fmt++) != '\0') { 3977 switch (c) { 3978 default: 3979 rtld_putchar(c); 3980 continue; 3981 case '\\': 3982 switch (c = *fmt) { 3983 case '\0': 3984 continue; 3985 case 'n': 3986 rtld_putchar('\n'); 3987 break; 3988 case 't': 3989 rtld_putchar('\t'); 3990 break; 3991 } 3992 break; 3993 case '%': 3994 switch (c = *fmt) { 3995 case '\0': 3996 continue; 3997 case '%': 3998 default: 3999 rtld_putchar(c); 4000 break; 4001 case 'A': 4002 rtld_putstr(main_local); 4003 break; 4004 case 'a': 4005 rtld_putstr(obj_main->path); 4006 break; 4007 case 'o': 4008 rtld_putstr(name); 4009 break; 4010 #if 0 4011 case 'm': 4012 rtld_printf("%d", sodp->sod_major); 4013 break; 4014 case 'n': 4015 rtld_printf("%d", sodp->sod_minor); 4016 break; 4017 #endif 4018 case 'p': 4019 rtld_putstr(path); 4020 break; 4021 case 'x': 4022 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4023 0); 4024 break; 4025 } 4026 break; 4027 } 4028 ++fmt; 4029 } 4030 } 4031 } 4032 } 4033 4034 /* 4035 * Unload a dlopened object and its dependencies from memory and from 4036 * our data structures. It is assumed that the DAG rooted in the 4037 * object has already been unreferenced, and that the object has a 4038 * reference count of 0. 4039 */ 4040 static void 4041 unload_object(Obj_Entry *root) 4042 { 4043 Obj_Entry *obj; 4044 Obj_Entry **linkp; 4045 4046 assert(root->refcount == 0); 4047 4048 /* 4049 * Pass over the DAG removing unreferenced objects from 4050 * appropriate lists. 4051 */ 4052 unlink_object(root); 4053 4054 /* Unmap all objects that are no longer referenced. */ 4055 linkp = &obj_list->next; 4056 while ((obj = *linkp) != NULL) { 4057 if (obj->refcount == 0) { 4058 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4059 obj->path); 4060 dbg("unloading \"%s\"", obj->path); 4061 unload_filtees(root); 4062 munmap(obj->mapbase, obj->mapsize); 4063 linkmap_delete(obj); 4064 *linkp = obj->next; 4065 obj_count--; 4066 obj_free(obj); 4067 } else 4068 linkp = &obj->next; 4069 } 4070 obj_tail = linkp; 4071 } 4072 4073 static void 4074 unlink_object(Obj_Entry *root) 4075 { 4076 Objlist_Entry *elm; 4077 4078 if (root->refcount == 0) { 4079 /* Remove the object from the RTLD_GLOBAL list. */ 4080 objlist_remove(&list_global, root); 4081 4082 /* Remove the object from all objects' DAG lists. */ 4083 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4084 objlist_remove(&elm->obj->dldags, root); 4085 if (elm->obj != root) 4086 unlink_object(elm->obj); 4087 } 4088 } 4089 } 4090 4091 static void 4092 ref_dag(Obj_Entry *root) 4093 { 4094 Objlist_Entry *elm; 4095 4096 assert(root->dag_inited); 4097 STAILQ_FOREACH(elm, &root->dagmembers, link) 4098 elm->obj->refcount++; 4099 } 4100 4101 static void 4102 unref_dag(Obj_Entry *root) 4103 { 4104 Objlist_Entry *elm; 4105 4106 assert(root->dag_inited); 4107 STAILQ_FOREACH(elm, &root->dagmembers, link) 4108 elm->obj->refcount--; 4109 } 4110 4111 /* 4112 * Common code for MD __tls_get_addr(). 4113 */ 4114 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4115 static void * 4116 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4117 { 4118 Elf_Addr *newdtv, *dtv; 4119 RtldLockState lockstate; 4120 int to_copy; 4121 4122 dtv = *dtvp; 4123 /* Check dtv generation in case new modules have arrived */ 4124 if (dtv[0] != tls_dtv_generation) { 4125 wlock_acquire(rtld_bind_lock, &lockstate); 4126 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4127 to_copy = dtv[1]; 4128 if (to_copy > tls_max_index) 4129 to_copy = tls_max_index; 4130 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4131 newdtv[0] = tls_dtv_generation; 4132 newdtv[1] = tls_max_index; 4133 free(dtv); 4134 lock_release(rtld_bind_lock, &lockstate); 4135 dtv = *dtvp = newdtv; 4136 } 4137 4138 /* Dynamically allocate module TLS if necessary */ 4139 if (dtv[index + 1] == 0) { 4140 /* Signal safe, wlock will block out signals. */ 4141 wlock_acquire(rtld_bind_lock, &lockstate); 4142 if (!dtv[index + 1]) 4143 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4144 lock_release(rtld_bind_lock, &lockstate); 4145 } 4146 return ((void *)(dtv[index + 1] + offset)); 4147 } 4148 4149 void * 4150 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4151 { 4152 Elf_Addr *dtv; 4153 4154 dtv = *dtvp; 4155 /* Check dtv generation in case new modules have arrived */ 4156 if (__predict_true(dtv[0] == tls_dtv_generation && 4157 dtv[index + 1] != 0)) 4158 return ((void *)(dtv[index + 1] + offset)); 4159 return (tls_get_addr_slow(dtvp, index, offset)); 4160 } 4161 4162 #if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4163 4164 /* 4165 * Allocate Static TLS using the Variant I method. 4166 */ 4167 void * 4168 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4169 { 4170 Obj_Entry *obj; 4171 char *tcb; 4172 Elf_Addr **tls; 4173 Elf_Addr *dtv; 4174 Elf_Addr addr; 4175 int i; 4176 4177 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4178 return (oldtcb); 4179 4180 assert(tcbsize >= TLS_TCB_SIZE); 4181 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4182 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4183 4184 if (oldtcb != NULL) { 4185 memcpy(tls, oldtcb, tls_static_space); 4186 free(oldtcb); 4187 4188 /* Adjust the DTV. */ 4189 dtv = tls[0]; 4190 for (i = 0; i < dtv[1]; i++) { 4191 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4192 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4193 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4194 } 4195 } 4196 } else { 4197 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4198 tls[0] = dtv; 4199 dtv[0] = tls_dtv_generation; 4200 dtv[1] = tls_max_index; 4201 4202 for (obj = objs; obj; obj = obj->next) { 4203 if (obj->tlsoffset > 0) { 4204 addr = (Elf_Addr)tls + obj->tlsoffset; 4205 if (obj->tlsinitsize > 0) 4206 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4207 if (obj->tlssize > obj->tlsinitsize) 4208 memset((void*) (addr + obj->tlsinitsize), 0, 4209 obj->tlssize - obj->tlsinitsize); 4210 dtv[obj->tlsindex + 1] = addr; 4211 } 4212 } 4213 } 4214 4215 return (tcb); 4216 } 4217 4218 void 4219 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4220 { 4221 Elf_Addr *dtv; 4222 Elf_Addr tlsstart, tlsend; 4223 int dtvsize, i; 4224 4225 assert(tcbsize >= TLS_TCB_SIZE); 4226 4227 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4228 tlsend = tlsstart + tls_static_space; 4229 4230 dtv = *(Elf_Addr **)tlsstart; 4231 dtvsize = dtv[1]; 4232 for (i = 0; i < dtvsize; i++) { 4233 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4234 free((void*)dtv[i+2]); 4235 } 4236 } 4237 free(dtv); 4238 free(tcb); 4239 } 4240 4241 #endif 4242 4243 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4244 4245 /* 4246 * Allocate Static TLS using the Variant II method. 4247 */ 4248 void * 4249 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4250 { 4251 Obj_Entry *obj; 4252 size_t size; 4253 char *tls; 4254 Elf_Addr *dtv, *olddtv; 4255 Elf_Addr segbase, oldsegbase, addr; 4256 int i; 4257 4258 size = round(tls_static_space, tcbalign); 4259 4260 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4261 tls = xcalloc(1, size + tcbsize); 4262 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4263 4264 segbase = (Elf_Addr)(tls + size); 4265 ((Elf_Addr*)segbase)[0] = segbase; 4266 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4267 4268 dtv[0] = tls_dtv_generation; 4269 dtv[1] = tls_max_index; 4270 4271 if (oldtls) { 4272 /* 4273 * Copy the static TLS block over whole. 4274 */ 4275 oldsegbase = (Elf_Addr) oldtls; 4276 memcpy((void *)(segbase - tls_static_space), 4277 (const void *)(oldsegbase - tls_static_space), 4278 tls_static_space); 4279 4280 /* 4281 * If any dynamic TLS blocks have been created tls_get_addr(), 4282 * move them over. 4283 */ 4284 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4285 for (i = 0; i < olddtv[1]; i++) { 4286 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4287 dtv[i+2] = olddtv[i+2]; 4288 olddtv[i+2] = 0; 4289 } 4290 } 4291 4292 /* 4293 * We assume that this block was the one we created with 4294 * allocate_initial_tls(). 4295 */ 4296 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4297 } else { 4298 for (obj = objs; obj; obj = obj->next) { 4299 if (obj->tlsoffset) { 4300 addr = segbase - obj->tlsoffset; 4301 memset((void*) (addr + obj->tlsinitsize), 4302 0, obj->tlssize - obj->tlsinitsize); 4303 if (obj->tlsinit) 4304 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4305 dtv[obj->tlsindex + 1] = addr; 4306 } 4307 } 4308 } 4309 4310 return (void*) segbase; 4311 } 4312 4313 void 4314 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4315 { 4316 size_t size; 4317 Elf_Addr* dtv; 4318 int dtvsize, i; 4319 Elf_Addr tlsstart, tlsend; 4320 4321 /* 4322 * Figure out the size of the initial TLS block so that we can 4323 * find stuff which ___tls_get_addr() allocated dynamically. 4324 */ 4325 size = round(tls_static_space, tcbalign); 4326 4327 dtv = ((Elf_Addr**)tls)[1]; 4328 dtvsize = dtv[1]; 4329 tlsend = (Elf_Addr) tls; 4330 tlsstart = tlsend - size; 4331 for (i = 0; i < dtvsize; i++) { 4332 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 4333 free((void*) dtv[i+2]); 4334 } 4335 } 4336 4337 free((void*) tlsstart); 4338 free((void*) dtv); 4339 } 4340 4341 #endif 4342 4343 /* 4344 * Allocate TLS block for module with given index. 4345 */ 4346 void * 4347 allocate_module_tls(int index) 4348 { 4349 Obj_Entry* obj; 4350 char* p; 4351 4352 for (obj = obj_list; obj; obj = obj->next) { 4353 if (obj->tlsindex == index) 4354 break; 4355 } 4356 if (!obj) { 4357 _rtld_error("Can't find module with TLS index %d", index); 4358 die(); 4359 } 4360 4361 p = malloc(obj->tlssize); 4362 if (p == NULL) { 4363 _rtld_error("Cannot allocate TLS block for index %d", index); 4364 die(); 4365 } 4366 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4367 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4368 4369 return p; 4370 } 4371 4372 bool 4373 allocate_tls_offset(Obj_Entry *obj) 4374 { 4375 size_t off; 4376 4377 if (obj->tls_done) 4378 return true; 4379 4380 if (obj->tlssize == 0) { 4381 obj->tls_done = true; 4382 return true; 4383 } 4384 4385 if (obj->tlsindex == 1) 4386 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4387 else 4388 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4389 obj->tlssize, obj->tlsalign); 4390 4391 /* 4392 * If we have already fixed the size of the static TLS block, we 4393 * must stay within that size. When allocating the static TLS, we 4394 * leave a small amount of space spare to be used for dynamically 4395 * loading modules which use static TLS. 4396 */ 4397 if (tls_static_space) { 4398 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4399 return false; 4400 } 4401 4402 tls_last_offset = obj->tlsoffset = off; 4403 tls_last_size = obj->tlssize; 4404 obj->tls_done = true; 4405 4406 return true; 4407 } 4408 4409 void 4410 free_tls_offset(Obj_Entry *obj) 4411 { 4412 4413 /* 4414 * If we were the last thing to allocate out of the static TLS 4415 * block, we give our space back to the 'allocator'. This is a 4416 * simplistic workaround to allow libGL.so.1 to be loaded and 4417 * unloaded multiple times. 4418 */ 4419 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4420 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4421 tls_last_offset -= obj->tlssize; 4422 tls_last_size = 0; 4423 } 4424 } 4425 4426 void * 4427 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4428 { 4429 void *ret; 4430 RtldLockState lockstate; 4431 4432 wlock_acquire(rtld_bind_lock, &lockstate); 4433 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4434 lock_release(rtld_bind_lock, &lockstate); 4435 return (ret); 4436 } 4437 4438 void 4439 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4440 { 4441 RtldLockState lockstate; 4442 4443 wlock_acquire(rtld_bind_lock, &lockstate); 4444 free_tls(tcb, tcbsize, tcbalign); 4445 lock_release(rtld_bind_lock, &lockstate); 4446 } 4447 4448 static void 4449 object_add_name(Obj_Entry *obj, const char *name) 4450 { 4451 Name_Entry *entry; 4452 size_t len; 4453 4454 len = strlen(name); 4455 entry = malloc(sizeof(Name_Entry) + len); 4456 4457 if (entry != NULL) { 4458 strcpy(entry->name, name); 4459 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4460 } 4461 } 4462 4463 static int 4464 object_match_name(const Obj_Entry *obj, const char *name) 4465 { 4466 Name_Entry *entry; 4467 4468 STAILQ_FOREACH(entry, &obj->names, link) { 4469 if (strcmp(name, entry->name) == 0) 4470 return (1); 4471 } 4472 return (0); 4473 } 4474 4475 static Obj_Entry * 4476 locate_dependency(const Obj_Entry *obj, const char *name) 4477 { 4478 const Objlist_Entry *entry; 4479 const Needed_Entry *needed; 4480 4481 STAILQ_FOREACH(entry, &list_main, link) { 4482 if (object_match_name(entry->obj, name)) 4483 return entry->obj; 4484 } 4485 4486 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4487 if (strcmp(obj->strtab + needed->name, name) == 0 || 4488 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4489 /* 4490 * If there is DT_NEEDED for the name we are looking for, 4491 * we are all set. Note that object might not be found if 4492 * dependency was not loaded yet, so the function can 4493 * return NULL here. This is expected and handled 4494 * properly by the caller. 4495 */ 4496 return (needed->obj); 4497 } 4498 } 4499 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4500 obj->path, name); 4501 die(); 4502 } 4503 4504 static int 4505 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4506 const Elf_Vernaux *vna) 4507 { 4508 const Elf_Verdef *vd; 4509 const char *vername; 4510 4511 vername = refobj->strtab + vna->vna_name; 4512 vd = depobj->verdef; 4513 if (vd == NULL) { 4514 _rtld_error("%s: version %s required by %s not defined", 4515 depobj->path, vername, refobj->path); 4516 return (-1); 4517 } 4518 for (;;) { 4519 if (vd->vd_version != VER_DEF_CURRENT) { 4520 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4521 depobj->path, vd->vd_version); 4522 return (-1); 4523 } 4524 if (vna->vna_hash == vd->vd_hash) { 4525 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4526 ((char *)vd + vd->vd_aux); 4527 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4528 return (0); 4529 } 4530 if (vd->vd_next == 0) 4531 break; 4532 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4533 } 4534 if (vna->vna_flags & VER_FLG_WEAK) 4535 return (0); 4536 _rtld_error("%s: version %s required by %s not found", 4537 depobj->path, vername, refobj->path); 4538 return (-1); 4539 } 4540 4541 static int 4542 rtld_verify_object_versions(Obj_Entry *obj) 4543 { 4544 const Elf_Verneed *vn; 4545 const Elf_Verdef *vd; 4546 const Elf_Verdaux *vda; 4547 const Elf_Vernaux *vna; 4548 const Obj_Entry *depobj; 4549 int maxvernum, vernum; 4550 4551 if (obj->ver_checked) 4552 return (0); 4553 obj->ver_checked = true; 4554 4555 maxvernum = 0; 4556 /* 4557 * Walk over defined and required version records and figure out 4558 * max index used by any of them. Do very basic sanity checking 4559 * while there. 4560 */ 4561 vn = obj->verneed; 4562 while (vn != NULL) { 4563 if (vn->vn_version != VER_NEED_CURRENT) { 4564 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4565 obj->path, vn->vn_version); 4566 return (-1); 4567 } 4568 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4569 for (;;) { 4570 vernum = VER_NEED_IDX(vna->vna_other); 4571 if (vernum > maxvernum) 4572 maxvernum = vernum; 4573 if (vna->vna_next == 0) 4574 break; 4575 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4576 } 4577 if (vn->vn_next == 0) 4578 break; 4579 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4580 } 4581 4582 vd = obj->verdef; 4583 while (vd != NULL) { 4584 if (vd->vd_version != VER_DEF_CURRENT) { 4585 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4586 obj->path, vd->vd_version); 4587 return (-1); 4588 } 4589 vernum = VER_DEF_IDX(vd->vd_ndx); 4590 if (vernum > maxvernum) 4591 maxvernum = vernum; 4592 if (vd->vd_next == 0) 4593 break; 4594 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4595 } 4596 4597 if (maxvernum == 0) 4598 return (0); 4599 4600 /* 4601 * Store version information in array indexable by version index. 4602 * Verify that object version requirements are satisfied along the 4603 * way. 4604 */ 4605 obj->vernum = maxvernum + 1; 4606 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4607 4608 vd = obj->verdef; 4609 while (vd != NULL) { 4610 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4611 vernum = VER_DEF_IDX(vd->vd_ndx); 4612 assert(vernum <= maxvernum); 4613 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4614 obj->vertab[vernum].hash = vd->vd_hash; 4615 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4616 obj->vertab[vernum].file = NULL; 4617 obj->vertab[vernum].flags = 0; 4618 } 4619 if (vd->vd_next == 0) 4620 break; 4621 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4622 } 4623 4624 vn = obj->verneed; 4625 while (vn != NULL) { 4626 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4627 if (depobj == NULL) 4628 return (-1); 4629 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4630 for (;;) { 4631 if (check_object_provided_version(obj, depobj, vna)) 4632 return (-1); 4633 vernum = VER_NEED_IDX(vna->vna_other); 4634 assert(vernum <= maxvernum); 4635 obj->vertab[vernum].hash = vna->vna_hash; 4636 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4637 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4638 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4639 VER_INFO_HIDDEN : 0; 4640 if (vna->vna_next == 0) 4641 break; 4642 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4643 } 4644 if (vn->vn_next == 0) 4645 break; 4646 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4647 } 4648 return 0; 4649 } 4650 4651 static int 4652 rtld_verify_versions(const Objlist *objlist) 4653 { 4654 Objlist_Entry *entry; 4655 int rc; 4656 4657 rc = 0; 4658 STAILQ_FOREACH(entry, objlist, link) { 4659 /* 4660 * Skip dummy objects or objects that have their version requirements 4661 * already checked. 4662 */ 4663 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4664 continue; 4665 if (rtld_verify_object_versions(entry->obj) == -1) { 4666 rc = -1; 4667 if (ld_tracing == NULL) 4668 break; 4669 } 4670 } 4671 if (rc == 0 || ld_tracing != NULL) 4672 rc = rtld_verify_object_versions(&obj_rtld); 4673 return rc; 4674 } 4675 4676 const Ver_Entry * 4677 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4678 { 4679 Elf_Versym vernum; 4680 4681 if (obj->vertab) { 4682 vernum = VER_NDX(obj->versyms[symnum]); 4683 if (vernum >= obj->vernum) { 4684 _rtld_error("%s: symbol %s has wrong verneed value %d", 4685 obj->path, obj->strtab + symnum, vernum); 4686 } else if (obj->vertab[vernum].hash != 0) { 4687 return &obj->vertab[vernum]; 4688 } 4689 } 4690 return NULL; 4691 } 4692 4693 int 4694 _rtld_get_stack_prot(void) 4695 { 4696 4697 return (stack_prot); 4698 } 4699 4700 static void 4701 map_stacks_exec(RtldLockState *lockstate) 4702 { 4703 void (*thr_map_stacks_exec)(void); 4704 4705 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4706 return; 4707 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4708 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4709 if (thr_map_stacks_exec != NULL) { 4710 stack_prot |= PROT_EXEC; 4711 thr_map_stacks_exec(); 4712 } 4713 } 4714 4715 void 4716 symlook_init(SymLook *dst, const char *name) 4717 { 4718 4719 bzero(dst, sizeof(*dst)); 4720 dst->name = name; 4721 dst->hash = elf_hash(name); 4722 dst->hash_gnu = gnu_hash(name); 4723 } 4724 4725 static void 4726 symlook_init_from_req(SymLook *dst, const SymLook *src) 4727 { 4728 4729 dst->name = src->name; 4730 dst->hash = src->hash; 4731 dst->hash_gnu = src->hash_gnu; 4732 dst->ventry = src->ventry; 4733 dst->flags = src->flags; 4734 dst->defobj_out = NULL; 4735 dst->sym_out = NULL; 4736 dst->lockstate = src->lockstate; 4737 } 4738 4739 /* 4740 * Overrides for libc_pic-provided functions. 4741 */ 4742 4743 int 4744 __getosreldate(void) 4745 { 4746 size_t len; 4747 int oid[2]; 4748 int error, osrel; 4749 4750 if (osreldate != 0) 4751 return (osreldate); 4752 4753 oid[0] = CTL_KERN; 4754 oid[1] = KERN_OSRELDATE; 4755 osrel = 0; 4756 len = sizeof(osrel); 4757 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4758 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4759 osreldate = osrel; 4760 return (osreldate); 4761 } 4762 4763 void 4764 exit(int status) 4765 { 4766 4767 _exit(status); 4768 } 4769 4770 void (*__cleanup)(void); 4771 int __isthreaded = 0; 4772 int _thread_autoinit_dummy_decl = 1; 4773 4774 /* 4775 * No unresolved symbols for rtld. 4776 */ 4777 void 4778 __pthread_cxa_finalize(struct dl_phdr_info *a) 4779 { 4780 } 4781 4782 void 4783 __stack_chk_fail(void) 4784 { 4785 4786 _rtld_error("stack overflow detected; terminated"); 4787 die(); 4788 } 4789 __weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4790 4791 void 4792 __chk_fail(void) 4793 { 4794 4795 _rtld_error("buffer overflow detected; terminated"); 4796 die(); 4797 } 4798 4799 const char * 4800 rtld_strerror(int errnum) 4801 { 4802 4803 if (errnum < 0 || errnum >= sys_nerr) 4804 return ("Unknown error"); 4805 return (sys_errlist[errnum]); 4806 } 4807