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