1 /*- 2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 4 * Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>. 5 * Copyright 2012 John Marino <draco@marino.st>. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 /* 32 * Dynamic linker for ELF. 33 * 34 * John Polstra <jdp@polstra.com>. 35 */ 36 37 #ifndef __GNUC__ 38 #error "GCC is needed to compile this file" 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/mount.h> 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 #include <sys/sysctl.h> 46 #include <sys/uio.h> 47 #include <sys/utsname.h> 48 #include <sys/ktrace.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "rtld.h" 62 #include "libmap.h" 63 #include "rtld_tls.h" 64 #include "rtld_printf.h" 65 #include "notes.h" 66 67 #ifndef COMPAT_32BIT 68 #define PATH_RTLD "/libexec/ld-elf.so.1" 69 #else 70 #define PATH_RTLD "/libexec/ld-elf32.so.1" 71 #endif 72 73 /* Types. */ 74 typedef void (*func_ptr_type)(); 75 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 76 77 /* 78 * Function declarations. 79 */ 80 static const char *basename(const char *); 81 static void die(void) __dead2; 82 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 83 const Elf_Dyn **, const Elf_Dyn **); 84 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 85 const Elf_Dyn *); 86 static void digest_dynamic(Obj_Entry *, int); 87 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 88 static Obj_Entry *dlcheck(void *); 89 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 90 int lo_flags, int mode, RtldLockState *lockstate); 91 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 92 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 93 static bool donelist_check(DoneList *, const Obj_Entry *); 94 static void errmsg_restore(char *); 95 static char *errmsg_save(void); 96 static void *fill_search_info(const char *, size_t, void *); 97 static char *find_library(const char *, const Obj_Entry *); 98 static const char *gethints(bool); 99 static void init_dag(Obj_Entry *); 100 static void init_rtld(caddr_t, Elf_Auxinfo **); 101 static void initlist_add_neededs(Needed_Entry *, Objlist *); 102 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 103 static void linkmap_add(Obj_Entry *); 104 static void linkmap_delete(Obj_Entry *); 105 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 106 static void unload_filtees(Obj_Entry *); 107 static int load_needed_objects(Obj_Entry *, int); 108 static int load_preload_objects(void); 109 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 110 static void map_stacks_exec(RtldLockState *); 111 static Obj_Entry *obj_from_addr(const void *); 112 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 113 static void objlist_call_init(Objlist *, RtldLockState *); 114 static void objlist_clear(Objlist *); 115 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 116 static void objlist_init(Objlist *); 117 static void objlist_push_head(Objlist *, Obj_Entry *); 118 static void objlist_push_tail(Objlist *, Obj_Entry *); 119 static void objlist_remove(Objlist *, Obj_Entry *); 120 static void *path_enumerate(const char *, path_enum_proc, void *); 121 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 122 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 123 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 124 int flags, RtldLockState *lockstate); 125 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 126 RtldLockState *); 127 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 128 int flags, RtldLockState *lockstate); 129 static int rtld_dirname(const char *, char *); 130 static int rtld_dirname_abs(const char *, char *); 131 static void *rtld_dlopen(const char *name, int fd, int mode); 132 static void rtld_exit(void); 133 static char *search_library_path(const char *, const char *); 134 static const void **get_program_var_addr(const char *, RtldLockState *); 135 static void set_program_var(const char *, const void *); 136 static int symlook_default(SymLook *, const Obj_Entry *refobj); 137 static int symlook_global(SymLook *, DoneList *); 138 static void symlook_init_from_req(SymLook *, const SymLook *); 139 static int symlook_list(SymLook *, const Objlist *, DoneList *); 140 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 141 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 142 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 143 static void trace_loaded_objects(Obj_Entry *); 144 static void unlink_object(Obj_Entry *); 145 static void unload_object(Obj_Entry *); 146 static void unref_dag(Obj_Entry *); 147 static void ref_dag(Obj_Entry *); 148 static char *origin_subst_one(char *, const char *, const char *, bool); 149 static char *origin_subst(char *, const char *); 150 static void preinit_main(void); 151 static int rtld_verify_versions(const Objlist *); 152 static int rtld_verify_object_versions(Obj_Entry *); 153 static void object_add_name(Obj_Entry *, const char *); 154 static int object_match_name(const Obj_Entry *, const char *); 155 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 156 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 157 struct dl_phdr_info *phdr_info); 158 static uint32_t gnu_hash(const char *); 159 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 160 const unsigned long); 161 162 void r_debug_state(struct r_debug *, struct link_map *) __noinline; 163 164 /* 165 * Data declarations. 166 */ 167 static char *error_message; /* Message for dlerror(), or NULL */ 168 struct r_debug r_debug; /* for GDB; */ 169 static bool libmap_disable; /* Disable libmap */ 170 static bool ld_loadfltr; /* Immediate filters processing */ 171 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 172 static bool trust; /* False for setuid and setgid programs */ 173 static bool dangerous_ld_env; /* True if environment variables have been 174 used to affect the libraries loaded */ 175 static char *ld_bind_now; /* Environment variable for immediate binding */ 176 static char *ld_debug; /* Environment variable for debugging */ 177 static char *ld_library_path; /* Environment variable for search path */ 178 static char *ld_preload; /* Environment variable for libraries to 179 load first */ 180 static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 181 static char *ld_tracing; /* Called from ldd to print libs */ 182 static char *ld_utrace; /* Use utrace() to log events. */ 183 static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 184 static Obj_Entry **obj_tail; /* Link field of last object in list */ 185 static Obj_Entry *obj_main; /* The main program shared object */ 186 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 187 static unsigned int obj_count; /* Number of objects in obj_list */ 188 static unsigned int obj_loads; /* Number of objects in obj_list */ 189 190 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 191 STAILQ_HEAD_INITIALIZER(list_global); 192 static Objlist list_main = /* Objects loaded at program startup */ 193 STAILQ_HEAD_INITIALIZER(list_main); 194 static Objlist list_fini = /* Objects needing fini() calls */ 195 STAILQ_HEAD_INITIALIZER(list_fini); 196 197 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 198 199 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 200 201 extern Elf_Dyn _DYNAMIC; 202 #pragma weak _DYNAMIC 203 #ifndef RTLD_IS_DYNAMIC 204 #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 205 #endif 206 207 int osreldate, pagesize; 208 209 long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 210 211 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 212 static int max_stack_flags; 213 214 /* 215 * Global declarations normally provided by crt1. The dynamic linker is 216 * not built with crt1, so we have to provide them ourselves. 217 */ 218 char *__progname; 219 char **environ; 220 221 /* 222 * Used to pass argc, argv to init functions. 223 */ 224 int main_argc; 225 char **main_argv; 226 227 /* 228 * Globals to control TLS allocation. 229 */ 230 size_t tls_last_offset; /* Static TLS offset of last module */ 231 size_t tls_last_size; /* Static TLS size of last module */ 232 size_t tls_static_space; /* Static TLS space allocated */ 233 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 234 int tls_max_index = 1; /* Largest module index allocated */ 235 236 bool ld_library_path_rpath = false; 237 238 /* 239 * Fill in a DoneList with an allocation large enough to hold all of 240 * the currently-loaded objects. Keep this as a macro since it calls 241 * alloca and we want that to occur within the scope of the caller. 242 */ 243 #define donelist_init(dlp) \ 244 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 245 assert((dlp)->objs != NULL), \ 246 (dlp)->num_alloc = obj_count, \ 247 (dlp)->num_used = 0) 248 249 #define UTRACE_DLOPEN_START 1 250 #define UTRACE_DLOPEN_STOP 2 251 #define UTRACE_DLCLOSE_START 3 252 #define UTRACE_DLCLOSE_STOP 4 253 #define UTRACE_LOAD_OBJECT 5 254 #define UTRACE_UNLOAD_OBJECT 6 255 #define UTRACE_ADD_RUNDEP 7 256 #define UTRACE_PRELOAD_FINISHED 8 257 #define UTRACE_INIT_CALL 9 258 #define UTRACE_FINI_CALL 10 259 260 struct utrace_rtld { 261 char sig[4]; /* 'RTLD' */ 262 int event; 263 void *handle; 264 void *mapbase; /* Used for 'parent' and 'init/fini' */ 265 size_t mapsize; 266 int refcnt; /* Used for 'mode' */ 267 char name[MAXPATHLEN]; 268 }; 269 270 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 271 if (ld_utrace != NULL) \ 272 ld_utrace_log(e, h, mb, ms, r, n); \ 273 } while (0) 274 275 static void 276 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 277 int refcnt, const char *name) 278 { 279 struct utrace_rtld ut; 280 281 ut.sig[0] = 'R'; 282 ut.sig[1] = 'T'; 283 ut.sig[2] = 'L'; 284 ut.sig[3] = 'D'; 285 ut.event = event; 286 ut.handle = handle; 287 ut.mapbase = mapbase; 288 ut.mapsize = mapsize; 289 ut.refcnt = refcnt; 290 bzero(ut.name, sizeof(ut.name)); 291 if (name) 292 strlcpy(ut.name, name, sizeof(ut.name)); 293 utrace(&ut, sizeof(ut)); 294 } 295 296 /* 297 * Main entry point for dynamic linking. The first argument is the 298 * stack pointer. The stack is expected to be laid out as described 299 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 300 * Specifically, the stack pointer points to a word containing 301 * ARGC. Following that in the stack is a null-terminated sequence 302 * of pointers to argument strings. Then comes a null-terminated 303 * sequence of pointers to environment strings. Finally, there is a 304 * sequence of "auxiliary vector" entries. 305 * 306 * The second argument points to a place to store the dynamic linker's 307 * exit procedure pointer and the third to a place to store the main 308 * program's object. 309 * 310 * The return value is the main program's entry point. 311 */ 312 func_ptr_type 313 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 314 { 315 Elf_Auxinfo *aux_info[AT_COUNT]; 316 int i; 317 int argc; 318 char **argv; 319 char **env; 320 Elf_Auxinfo *aux; 321 Elf_Auxinfo *auxp; 322 const char *argv0; 323 Objlist_Entry *entry; 324 Obj_Entry *obj; 325 Obj_Entry **preload_tail; 326 Objlist initlist; 327 RtldLockState lockstate; 328 char *library_path_rpath; 329 int mib[2]; 330 size_t len; 331 332 /* 333 * On entry, the dynamic linker itself has not been relocated yet. 334 * Be very careful not to reference any global data until after 335 * init_rtld has returned. It is OK to reference file-scope statics 336 * and string constants, and to call static and global functions. 337 */ 338 339 /* Find the auxiliary vector on the stack. */ 340 argc = *sp++; 341 argv = (char **) sp; 342 sp += argc + 1; /* Skip over arguments and NULL terminator */ 343 env = (char **) sp; 344 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 345 ; 346 aux = (Elf_Auxinfo *) sp; 347 348 /* Digest the auxiliary vector. */ 349 for (i = 0; i < AT_COUNT; i++) 350 aux_info[i] = NULL; 351 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 352 if (auxp->a_type < AT_COUNT) 353 aux_info[auxp->a_type] = auxp; 354 } 355 356 /* Initialize and relocate ourselves. */ 357 assert(aux_info[AT_BASE] != NULL); 358 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 359 360 __progname = obj_rtld.path; 361 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 362 environ = env; 363 main_argc = argc; 364 main_argv = argv; 365 366 if (aux_info[AT_CANARY] != NULL && 367 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 368 i = aux_info[AT_CANARYLEN]->a_un.a_val; 369 if (i > sizeof(__stack_chk_guard)) 370 i = sizeof(__stack_chk_guard); 371 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 372 } else { 373 mib[0] = CTL_KERN; 374 mib[1] = KERN_ARND; 375 376 len = sizeof(__stack_chk_guard); 377 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 378 len != sizeof(__stack_chk_guard)) { 379 /* If sysctl was unsuccessful, use the "terminator canary". */ 380 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 381 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 382 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 383 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 384 } 385 } 386 387 trust = !issetugid(); 388 389 ld_bind_now = getenv(LD_ "BIND_NOW"); 390 /* 391 * If the process is tainted, then we un-set the dangerous environment 392 * variables. The process will be marked as tainted until setuid(2) 393 * is called. If any child process calls setuid(2) we do not want any 394 * future processes to honor the potentially un-safe variables. 395 */ 396 if (!trust) { 397 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 398 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 399 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 400 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 401 _rtld_error("environment corrupt; aborting"); 402 die(); 403 } 404 } 405 ld_debug = getenv(LD_ "DEBUG"); 406 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 407 libmap_override = getenv(LD_ "LIBMAP"); 408 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 409 ld_preload = getenv(LD_ "PRELOAD"); 410 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 411 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 412 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 413 if (library_path_rpath != NULL) { 414 if (library_path_rpath[0] == 'y' || 415 library_path_rpath[0] == 'Y' || 416 library_path_rpath[0] == '1') 417 ld_library_path_rpath = true; 418 else 419 ld_library_path_rpath = false; 420 } 421 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 422 (ld_library_path != NULL) || (ld_preload != NULL) || 423 (ld_elf_hints_path != NULL) || ld_loadfltr; 424 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 425 ld_utrace = getenv(LD_ "UTRACE"); 426 427 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 428 ld_elf_hints_path = _PATH_ELF_HINTS; 429 430 if (ld_debug != NULL && *ld_debug != '\0') 431 debug = 1; 432 dbg("%s is initialized, base address = %p", __progname, 433 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 434 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 435 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 436 437 dbg("initializing thread locks"); 438 lockdflt_init(); 439 440 /* 441 * Load the main program, or process its program header if it is 442 * already loaded. 443 */ 444 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 445 int fd = aux_info[AT_EXECFD]->a_un.a_val; 446 dbg("loading main program"); 447 obj_main = map_object(fd, argv0, NULL); 448 close(fd); 449 if (obj_main == NULL) 450 die(); 451 max_stack_flags = obj->stack_flags; 452 } else { /* Main program already loaded. */ 453 const Elf_Phdr *phdr; 454 int phnum; 455 caddr_t entry; 456 457 dbg("processing main program's program header"); 458 assert(aux_info[AT_PHDR] != NULL); 459 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 460 assert(aux_info[AT_PHNUM] != NULL); 461 phnum = aux_info[AT_PHNUM]->a_un.a_val; 462 assert(aux_info[AT_PHENT] != NULL); 463 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 464 assert(aux_info[AT_ENTRY] != NULL); 465 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 466 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 467 die(); 468 } 469 470 if (aux_info[AT_EXECPATH] != 0) { 471 char *kexecpath; 472 char buf[MAXPATHLEN]; 473 474 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 475 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 476 if (kexecpath[0] == '/') 477 obj_main->path = kexecpath; 478 else if (getcwd(buf, sizeof(buf)) == NULL || 479 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 480 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 481 obj_main->path = xstrdup(argv0); 482 else 483 obj_main->path = xstrdup(buf); 484 } else { 485 dbg("No AT_EXECPATH"); 486 obj_main->path = xstrdup(argv0); 487 } 488 dbg("obj_main path %s", obj_main->path); 489 obj_main->mainprog = true; 490 491 if (aux_info[AT_STACKPROT] != NULL && 492 aux_info[AT_STACKPROT]->a_un.a_val != 0) 493 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 494 495 /* 496 * Get the actual dynamic linker pathname from the executable if 497 * possible. (It should always be possible.) That ensures that 498 * gdb will find the right dynamic linker even if a non-standard 499 * one is being used. 500 */ 501 if (obj_main->interp != NULL && 502 strcmp(obj_main->interp, obj_rtld.path) != 0) { 503 free(obj_rtld.path); 504 obj_rtld.path = xstrdup(obj_main->interp); 505 __progname = obj_rtld.path; 506 } 507 508 digest_dynamic(obj_main, 0); 509 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 510 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 511 obj_main->dynsymcount); 512 513 linkmap_add(obj_main); 514 linkmap_add(&obj_rtld); 515 516 /* Link the main program into the list of objects. */ 517 *obj_tail = obj_main; 518 obj_tail = &obj_main->next; 519 obj_count++; 520 obj_loads++; 521 522 /* Initialize a fake symbol for resolving undefined weak references. */ 523 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 524 sym_zero.st_shndx = SHN_UNDEF; 525 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 526 527 if (!libmap_disable) 528 libmap_disable = (bool)lm_init(libmap_override); 529 530 dbg("loading LD_PRELOAD libraries"); 531 if (load_preload_objects() == -1) 532 die(); 533 preload_tail = obj_tail; 534 535 dbg("loading needed objects"); 536 if (load_needed_objects(obj_main, 0) == -1) 537 die(); 538 539 /* Make a list of all objects loaded at startup. */ 540 for (obj = obj_list; obj != NULL; obj = obj->next) { 541 objlist_push_tail(&list_main, obj); 542 obj->refcount++; 543 } 544 545 dbg("checking for required versions"); 546 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 547 die(); 548 549 if (ld_tracing) { /* We're done */ 550 trace_loaded_objects(obj_main); 551 exit(0); 552 } 553 554 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 555 dump_relocations(obj_main); 556 exit (0); 557 } 558 559 /* 560 * Processing tls relocations requires having the tls offsets 561 * initialized. Prepare offsets before starting initial 562 * relocation processing. 563 */ 564 dbg("initializing initial thread local storage offsets"); 565 STAILQ_FOREACH(entry, &list_main, link) { 566 /* 567 * Allocate all the initial objects out of the static TLS 568 * block even if they didn't ask for it. 569 */ 570 allocate_tls_offset(entry->obj); 571 } 572 573 if (relocate_objects(obj_main, 574 ld_bind_now != NULL && *ld_bind_now != '\0', 575 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 576 die(); 577 578 dbg("doing copy relocations"); 579 if (do_copy_relocations(obj_main) == -1) 580 die(); 581 582 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 583 dump_relocations(obj_main); 584 exit (0); 585 } 586 587 /* 588 * Setup TLS for main thread. This must be done after the 589 * relocations are processed, since tls initialization section 590 * might be the subject for relocations. 591 */ 592 dbg("initializing initial thread local storage"); 593 allocate_initial_tls(obj_list); 594 595 dbg("initializing key program variables"); 596 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 597 set_program_var("environ", env); 598 set_program_var("__elf_aux_vector", aux); 599 600 /* Make a list of init functions to call. */ 601 objlist_init(&initlist); 602 initlist_add_objects(obj_list, preload_tail, &initlist); 603 604 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 605 606 map_stacks_exec(NULL); 607 608 dbg("resolving ifuncs"); 609 if (resolve_objects_ifunc(obj_main, 610 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 611 NULL) == -1) 612 die(); 613 614 if (!obj_main->crt_no_init) { 615 /* 616 * Make sure we don't call the main program's init and fini 617 * functions for binaries linked with old crt1 which calls 618 * _init itself. 619 */ 620 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 621 obj_main->preinit_array = obj_main->init_array = 622 obj_main->fini_array = (Elf_Addr)NULL; 623 } 624 625 wlock_acquire(rtld_bind_lock, &lockstate); 626 if (obj_main->crt_no_init) 627 preinit_main(); 628 objlist_call_init(&initlist, &lockstate); 629 objlist_clear(&initlist); 630 dbg("loading filtees"); 631 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 632 if (ld_loadfltr || obj->z_loadfltr) 633 load_filtees(obj, 0, &lockstate); 634 } 635 lock_release(rtld_bind_lock, &lockstate); 636 637 dbg("transferring control to program entry point = %p", obj_main->entry); 638 639 /* Return the exit procedure and the program entry point. */ 640 *exit_proc = rtld_exit; 641 *objp = obj_main; 642 return (func_ptr_type) obj_main->entry; 643 } 644 645 void * 646 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 647 { 648 void *ptr; 649 Elf_Addr target; 650 651 ptr = (void *)make_function_pointer(def, obj); 652 target = ((Elf_Addr (*)(void))ptr)(); 653 return ((void *)target); 654 } 655 656 Elf_Addr 657 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 658 { 659 const Elf_Rel *rel; 660 const Elf_Sym *def; 661 const Obj_Entry *defobj; 662 Elf_Addr *where; 663 Elf_Addr target; 664 RtldLockState lockstate; 665 666 rlock_acquire(rtld_bind_lock, &lockstate); 667 if (sigsetjmp(lockstate.env, 0) != 0) 668 lock_upgrade(rtld_bind_lock, &lockstate); 669 if (obj->pltrel) 670 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 671 else 672 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 673 674 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 675 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 676 &lockstate); 677 if (def == NULL) 678 die(); 679 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 680 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 681 else 682 target = (Elf_Addr)(defobj->relocbase + def->st_value); 683 684 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 685 defobj->strtab + def->st_name, basename(obj->path), 686 (void *)target, basename(defobj->path)); 687 688 /* 689 * Write the new contents for the jmpslot. Note that depending on 690 * architecture, the value which we need to return back to the 691 * lazy binding trampoline may or may not be the target 692 * address. The value returned from reloc_jmpslot() is the value 693 * that the trampoline needs. 694 */ 695 target = reloc_jmpslot(where, target, defobj, obj, rel); 696 lock_release(rtld_bind_lock, &lockstate); 697 return target; 698 } 699 700 /* 701 * Error reporting function. Use it like printf. If formats the message 702 * into a buffer, and sets things up so that the next call to dlerror() 703 * will return the message. 704 */ 705 void 706 _rtld_error(const char *fmt, ...) 707 { 708 static char buf[512]; 709 va_list ap; 710 711 va_start(ap, fmt); 712 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 713 error_message = buf; 714 va_end(ap); 715 } 716 717 /* 718 * Return a dynamically-allocated copy of the current error message, if any. 719 */ 720 static char * 721 errmsg_save(void) 722 { 723 return error_message == NULL ? NULL : xstrdup(error_message); 724 } 725 726 /* 727 * Restore the current error message from a copy which was previously saved 728 * by errmsg_save(). The copy is freed. 729 */ 730 static void 731 errmsg_restore(char *saved_msg) 732 { 733 if (saved_msg == NULL) 734 error_message = NULL; 735 else { 736 _rtld_error("%s", saved_msg); 737 free(saved_msg); 738 } 739 } 740 741 static const char * 742 basename(const char *name) 743 { 744 const char *p = strrchr(name, '/'); 745 return p != NULL ? p + 1 : name; 746 } 747 748 static struct utsname uts; 749 750 static char * 751 origin_subst_one(char *real, const char *kw, const char *subst, 752 bool may_free) 753 { 754 char *p, *p1, *res, *resp; 755 int subst_len, kw_len, subst_count, old_len, new_len; 756 757 kw_len = strlen(kw); 758 759 /* 760 * First, count the number of the keyword occurences, to 761 * preallocate the final string. 762 */ 763 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 764 p1 = strstr(p, kw); 765 if (p1 == NULL) 766 break; 767 } 768 769 /* 770 * If the keyword is not found, just return. 771 */ 772 if (subst_count == 0) 773 return (may_free ? real : xstrdup(real)); 774 775 /* 776 * There is indeed something to substitute. Calculate the 777 * length of the resulting string, and allocate it. 778 */ 779 subst_len = strlen(subst); 780 old_len = strlen(real); 781 new_len = old_len + (subst_len - kw_len) * subst_count; 782 res = xmalloc(new_len + 1); 783 784 /* 785 * Now, execute the substitution loop. 786 */ 787 for (p = real, resp = res, *resp = '\0';;) { 788 p1 = strstr(p, kw); 789 if (p1 != NULL) { 790 /* Copy the prefix before keyword. */ 791 memcpy(resp, p, p1 - p); 792 resp += p1 - p; 793 /* Keyword replacement. */ 794 memcpy(resp, subst, subst_len); 795 resp += subst_len; 796 *resp = '\0'; 797 p = p1 + kw_len; 798 } else 799 break; 800 } 801 802 /* Copy to the end of string and finish. */ 803 strcat(resp, p); 804 if (may_free) 805 free(real); 806 return (res); 807 } 808 809 static char * 810 origin_subst(char *real, const char *origin_path) 811 { 812 char *res1, *res2, *res3, *res4; 813 814 if (uts.sysname[0] == '\0') { 815 if (uname(&uts) != 0) { 816 _rtld_error("utsname failed: %d", errno); 817 return (NULL); 818 } 819 } 820 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 821 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 822 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 823 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 824 return (res4); 825 } 826 827 static void 828 die(void) 829 { 830 const char *msg = dlerror(); 831 832 if (msg == NULL) 833 msg = "Fatal error"; 834 rtld_fdputstr(STDERR_FILENO, msg); 835 rtld_fdputchar(STDERR_FILENO, '\n'); 836 _exit(1); 837 } 838 839 /* 840 * Process a shared object's DYNAMIC section, and save the important 841 * information in its Obj_Entry structure. 842 */ 843 static void 844 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 845 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 846 { 847 const Elf_Dyn *dynp; 848 Needed_Entry **needed_tail = &obj->needed; 849 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 850 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 851 const Elf_Hashelt *hashtab; 852 const Elf32_Word *hashval; 853 Elf32_Word bkt, nmaskwords; 854 int bloom_size32; 855 bool nmw_power2; 856 int plttype = DT_REL; 857 858 *dyn_rpath = NULL; 859 *dyn_soname = NULL; 860 *dyn_runpath = NULL; 861 862 obj->bind_now = false; 863 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 864 switch (dynp->d_tag) { 865 866 case DT_REL: 867 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 868 break; 869 870 case DT_RELSZ: 871 obj->relsize = dynp->d_un.d_val; 872 break; 873 874 case DT_RELENT: 875 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 876 break; 877 878 case DT_JMPREL: 879 obj->pltrel = (const Elf_Rel *) 880 (obj->relocbase + dynp->d_un.d_ptr); 881 break; 882 883 case DT_PLTRELSZ: 884 obj->pltrelsize = dynp->d_un.d_val; 885 break; 886 887 case DT_RELA: 888 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 889 break; 890 891 case DT_RELASZ: 892 obj->relasize = dynp->d_un.d_val; 893 break; 894 895 case DT_RELAENT: 896 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 897 break; 898 899 case DT_PLTREL: 900 plttype = dynp->d_un.d_val; 901 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 902 break; 903 904 case DT_SYMTAB: 905 obj->symtab = (const Elf_Sym *) 906 (obj->relocbase + dynp->d_un.d_ptr); 907 break; 908 909 case DT_SYMENT: 910 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 911 break; 912 913 case DT_STRTAB: 914 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 915 break; 916 917 case DT_STRSZ: 918 obj->strsize = dynp->d_un.d_val; 919 break; 920 921 case DT_VERNEED: 922 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 923 dynp->d_un.d_val); 924 break; 925 926 case DT_VERNEEDNUM: 927 obj->verneednum = dynp->d_un.d_val; 928 break; 929 930 case DT_VERDEF: 931 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 932 dynp->d_un.d_val); 933 break; 934 935 case DT_VERDEFNUM: 936 obj->verdefnum = dynp->d_un.d_val; 937 break; 938 939 case DT_VERSYM: 940 obj->versyms = (const Elf_Versym *)(obj->relocbase + 941 dynp->d_un.d_val); 942 break; 943 944 case DT_HASH: 945 { 946 hashtab = (const Elf_Hashelt *)(obj->relocbase + 947 dynp->d_un.d_ptr); 948 obj->nbuckets = hashtab[0]; 949 obj->nchains = hashtab[1]; 950 obj->buckets = hashtab + 2; 951 obj->chains = obj->buckets + obj->nbuckets; 952 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 953 obj->buckets != NULL; 954 } 955 break; 956 957 case DT_GNU_HASH: 958 { 959 hashtab = (const Elf_Hashelt *)(obj->relocbase + 960 dynp->d_un.d_ptr); 961 obj->nbuckets_gnu = hashtab[0]; 962 obj->symndx_gnu = hashtab[1]; 963 nmaskwords = hashtab[2]; 964 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 965 /* Number of bitmask words is required to be power of 2 */ 966 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 967 obj->maskwords_bm_gnu = nmaskwords - 1; 968 obj->shift2_gnu = hashtab[3]; 969 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 970 obj->buckets_gnu = hashtab + 4 + bloom_size32; 971 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 972 obj->symndx_gnu; 973 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 974 obj->buckets_gnu != NULL; 975 } 976 break; 977 978 case DT_NEEDED: 979 if (!obj->rtld) { 980 Needed_Entry *nep = NEW(Needed_Entry); 981 nep->name = dynp->d_un.d_val; 982 nep->obj = NULL; 983 nep->next = NULL; 984 985 *needed_tail = nep; 986 needed_tail = &nep->next; 987 } 988 break; 989 990 case DT_FILTER: 991 if (!obj->rtld) { 992 Needed_Entry *nep = NEW(Needed_Entry); 993 nep->name = dynp->d_un.d_val; 994 nep->obj = NULL; 995 nep->next = NULL; 996 997 *needed_filtees_tail = nep; 998 needed_filtees_tail = &nep->next; 999 } 1000 break; 1001 1002 case DT_AUXILIARY: 1003 if (!obj->rtld) { 1004 Needed_Entry *nep = NEW(Needed_Entry); 1005 nep->name = dynp->d_un.d_val; 1006 nep->obj = NULL; 1007 nep->next = NULL; 1008 1009 *needed_aux_filtees_tail = nep; 1010 needed_aux_filtees_tail = &nep->next; 1011 } 1012 break; 1013 1014 case DT_PLTGOT: 1015 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1016 break; 1017 1018 case DT_TEXTREL: 1019 obj->textrel = true; 1020 break; 1021 1022 case DT_SYMBOLIC: 1023 obj->symbolic = true; 1024 break; 1025 1026 case DT_RPATH: 1027 /* 1028 * We have to wait until later to process this, because we 1029 * might not have gotten the address of the string table yet. 1030 */ 1031 *dyn_rpath = dynp; 1032 break; 1033 1034 case DT_SONAME: 1035 *dyn_soname = dynp; 1036 break; 1037 1038 case DT_RUNPATH: 1039 *dyn_runpath = dynp; 1040 break; 1041 1042 case DT_INIT: 1043 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1044 break; 1045 1046 case DT_PREINIT_ARRAY: 1047 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1048 break; 1049 1050 case DT_PREINIT_ARRAYSZ: 1051 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1052 break; 1053 1054 case DT_INIT_ARRAY: 1055 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1056 break; 1057 1058 case DT_INIT_ARRAYSZ: 1059 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1060 break; 1061 1062 case DT_FINI: 1063 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1064 break; 1065 1066 case DT_FINI_ARRAY: 1067 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1068 break; 1069 1070 case DT_FINI_ARRAYSZ: 1071 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1072 break; 1073 1074 /* 1075 * Don't process DT_DEBUG on MIPS as the dynamic section 1076 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1077 */ 1078 1079 #ifndef __mips__ 1080 case DT_DEBUG: 1081 /* XXX - not implemented yet */ 1082 if (!early) 1083 dbg("Filling in DT_DEBUG entry"); 1084 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1085 break; 1086 #endif 1087 1088 case DT_FLAGS: 1089 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1090 obj->z_origin = true; 1091 if (dynp->d_un.d_val & DF_SYMBOLIC) 1092 obj->symbolic = true; 1093 if (dynp->d_un.d_val & DF_TEXTREL) 1094 obj->textrel = true; 1095 if (dynp->d_un.d_val & DF_BIND_NOW) 1096 obj->bind_now = true; 1097 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1098 ;*/ 1099 break; 1100 #ifdef __mips__ 1101 case DT_MIPS_LOCAL_GOTNO: 1102 obj->local_gotno = dynp->d_un.d_val; 1103 break; 1104 1105 case DT_MIPS_SYMTABNO: 1106 obj->symtabno = dynp->d_un.d_val; 1107 break; 1108 1109 case DT_MIPS_GOTSYM: 1110 obj->gotsym = dynp->d_un.d_val; 1111 break; 1112 1113 case DT_MIPS_RLD_MAP: 1114 #ifdef notyet 1115 if (!early) 1116 dbg("Filling in DT_DEBUG entry"); 1117 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1118 #endif 1119 break; 1120 #endif 1121 1122 case DT_FLAGS_1: 1123 if (dynp->d_un.d_val & DF_1_NOOPEN) 1124 obj->z_noopen = true; 1125 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1126 obj->z_origin = true; 1127 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1128 XXX ;*/ 1129 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1130 obj->bind_now = true; 1131 if (dynp->d_un.d_val & DF_1_NODELETE) 1132 obj->z_nodelete = true; 1133 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1134 obj->z_loadfltr = true; 1135 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1136 obj->z_nodeflib = true; 1137 break; 1138 1139 default: 1140 if (!early) { 1141 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1142 (long)dynp->d_tag); 1143 } 1144 break; 1145 } 1146 } 1147 1148 obj->traced = false; 1149 1150 if (plttype == DT_RELA) { 1151 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1152 obj->pltrel = NULL; 1153 obj->pltrelasize = obj->pltrelsize; 1154 obj->pltrelsize = 0; 1155 } 1156 1157 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1158 if (obj->valid_hash_sysv) 1159 obj->dynsymcount = obj->nchains; 1160 else if (obj->valid_hash_gnu) { 1161 obj->dynsymcount = 0; 1162 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1163 if (obj->buckets_gnu[bkt] == 0) 1164 continue; 1165 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1166 do 1167 obj->dynsymcount++; 1168 while ((*hashval++ & 1u) == 0); 1169 } 1170 obj->dynsymcount += obj->symndx_gnu; 1171 } 1172 } 1173 1174 static void 1175 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1176 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1177 { 1178 1179 if (obj->z_origin && obj->origin_path == NULL) { 1180 obj->origin_path = xmalloc(PATH_MAX); 1181 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1182 die(); 1183 } 1184 1185 if (dyn_runpath != NULL) { 1186 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1187 if (obj->z_origin) 1188 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1189 } 1190 else if (dyn_rpath != NULL) { 1191 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1192 if (obj->z_origin) 1193 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1194 } 1195 1196 if (dyn_soname != NULL) 1197 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1198 } 1199 1200 static void 1201 digest_dynamic(Obj_Entry *obj, int early) 1202 { 1203 const Elf_Dyn *dyn_rpath; 1204 const Elf_Dyn *dyn_soname; 1205 const Elf_Dyn *dyn_runpath; 1206 1207 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1208 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1209 } 1210 1211 /* 1212 * Process a shared object's program header. This is used only for the 1213 * main program, when the kernel has already loaded the main program 1214 * into memory before calling the dynamic linker. It creates and 1215 * returns an Obj_Entry structure. 1216 */ 1217 static Obj_Entry * 1218 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1219 { 1220 Obj_Entry *obj; 1221 const Elf_Phdr *phlimit = phdr + phnum; 1222 const Elf_Phdr *ph; 1223 Elf_Addr note_start, note_end; 1224 int nsegs = 0; 1225 1226 obj = obj_new(); 1227 for (ph = phdr; ph < phlimit; ph++) { 1228 if (ph->p_type != PT_PHDR) 1229 continue; 1230 1231 obj->phdr = phdr; 1232 obj->phsize = ph->p_memsz; 1233 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1234 break; 1235 } 1236 1237 obj->stack_flags = PF_X | PF_R | PF_W; 1238 1239 for (ph = phdr; ph < phlimit; ph++) { 1240 switch (ph->p_type) { 1241 1242 case PT_INTERP: 1243 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1244 break; 1245 1246 case PT_LOAD: 1247 if (nsegs == 0) { /* First load segment */ 1248 obj->vaddrbase = trunc_page(ph->p_vaddr); 1249 obj->mapbase = obj->vaddrbase + obj->relocbase; 1250 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1251 obj->vaddrbase; 1252 } else { /* Last load segment */ 1253 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1254 obj->vaddrbase; 1255 } 1256 nsegs++; 1257 break; 1258 1259 case PT_DYNAMIC: 1260 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1261 break; 1262 1263 case PT_TLS: 1264 obj->tlsindex = 1; 1265 obj->tlssize = ph->p_memsz; 1266 obj->tlsalign = ph->p_align; 1267 obj->tlsinitsize = ph->p_filesz; 1268 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1269 break; 1270 1271 case PT_GNU_STACK: 1272 obj->stack_flags = ph->p_flags; 1273 break; 1274 1275 case PT_GNU_RELRO: 1276 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1277 obj->relro_size = round_page(ph->p_memsz); 1278 break; 1279 1280 case PT_NOTE: 1281 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1282 note_end = note_start + ph->p_filesz; 1283 digest_notes(obj, note_start, note_end); 1284 break; 1285 } 1286 } 1287 if (nsegs < 1) { 1288 _rtld_error("%s: too few PT_LOAD segments", path); 1289 return NULL; 1290 } 1291 1292 obj->entry = entry; 1293 return obj; 1294 } 1295 1296 void 1297 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1298 { 1299 const Elf_Note *note; 1300 const char *note_name; 1301 uintptr_t p; 1302 1303 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1304 note = (const Elf_Note *)((const char *)(note + 1) + 1305 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1306 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1307 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1308 note->n_descsz != sizeof(int32_t)) 1309 continue; 1310 if (note->n_type != ABI_NOTETYPE && 1311 note->n_type != CRT_NOINIT_NOTETYPE) 1312 continue; 1313 note_name = (const char *)(note + 1); 1314 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1315 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1316 continue; 1317 switch (note->n_type) { 1318 case ABI_NOTETYPE: 1319 /* FreeBSD osrel note */ 1320 p = (uintptr_t)(note + 1); 1321 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1322 obj->osrel = *(const int32_t *)(p); 1323 dbg("note osrel %d", obj->osrel); 1324 break; 1325 case CRT_NOINIT_NOTETYPE: 1326 /* FreeBSD 'crt does not call init' note */ 1327 obj->crt_no_init = true; 1328 dbg("note crt_no_init"); 1329 break; 1330 } 1331 } 1332 } 1333 1334 static Obj_Entry * 1335 dlcheck(void *handle) 1336 { 1337 Obj_Entry *obj; 1338 1339 for (obj = obj_list; obj != NULL; obj = obj->next) 1340 if (obj == (Obj_Entry *) handle) 1341 break; 1342 1343 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1344 _rtld_error("Invalid shared object handle %p", handle); 1345 return NULL; 1346 } 1347 return obj; 1348 } 1349 1350 /* 1351 * If the given object is already in the donelist, return true. Otherwise 1352 * add the object to the list and return false. 1353 */ 1354 static bool 1355 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1356 { 1357 unsigned int i; 1358 1359 for (i = 0; i < dlp->num_used; i++) 1360 if (dlp->objs[i] == obj) 1361 return true; 1362 /* 1363 * Our donelist allocation should always be sufficient. But if 1364 * our threads locking isn't working properly, more shared objects 1365 * could have been loaded since we allocated the list. That should 1366 * never happen, but we'll handle it properly just in case it does. 1367 */ 1368 if (dlp->num_used < dlp->num_alloc) 1369 dlp->objs[dlp->num_used++] = obj; 1370 return false; 1371 } 1372 1373 /* 1374 * Hash function for symbol table lookup. Don't even think about changing 1375 * this. It is specified by the System V ABI. 1376 */ 1377 unsigned long 1378 elf_hash(const char *name) 1379 { 1380 const unsigned char *p = (const unsigned char *) name; 1381 unsigned long h = 0; 1382 unsigned long g; 1383 1384 while (*p != '\0') { 1385 h = (h << 4) + *p++; 1386 if ((g = h & 0xf0000000) != 0) 1387 h ^= g >> 24; 1388 h &= ~g; 1389 } 1390 return h; 1391 } 1392 1393 /* 1394 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1395 * unsigned in case it's implemented with a wider type. 1396 */ 1397 static uint32_t 1398 gnu_hash(const char *s) 1399 { 1400 uint32_t h; 1401 unsigned char c; 1402 1403 h = 5381; 1404 for (c = *s; c != '\0'; c = *++s) 1405 h = h * 33 + c; 1406 return (h & 0xffffffff); 1407 } 1408 1409 /* 1410 * Find the library with the given name, and return its full pathname. 1411 * The returned string is dynamically allocated. Generates an error 1412 * message and returns NULL if the library cannot be found. 1413 * 1414 * If the second argument is non-NULL, then it refers to an already- 1415 * loaded shared object, whose library search path will be searched. 1416 * 1417 * The search order is: 1418 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1419 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1420 * LD_LIBRARY_PATH 1421 * DT_RUNPATH in the referencing file 1422 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1423 * from list) 1424 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1425 * 1426 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1427 */ 1428 static char * 1429 find_library(const char *xname, const Obj_Entry *refobj) 1430 { 1431 char *pathname; 1432 char *name; 1433 bool nodeflib, objgiven; 1434 1435 objgiven = refobj != NULL; 1436 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1437 if (xname[0] != '/' && !trust) { 1438 _rtld_error("Absolute pathname required for shared object \"%s\"", 1439 xname); 1440 return NULL; 1441 } 1442 if (objgiven && refobj->z_origin) { 1443 return (origin_subst(__DECONST(char *, xname), 1444 refobj->origin_path)); 1445 } else { 1446 return (xstrdup(xname)); 1447 } 1448 } 1449 1450 if (libmap_disable || !objgiven || 1451 (name = lm_find(refobj->path, xname)) == NULL) 1452 name = (char *)xname; 1453 1454 dbg(" Searching for \"%s\"", name); 1455 1456 /* 1457 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1458 * back to pre-conforming behaviour if user requested so with 1459 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1460 * nodeflib. 1461 */ 1462 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1463 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1464 (refobj != NULL && 1465 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1466 (pathname = search_library_path(name, gethints(false))) != NULL || 1467 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1468 return (pathname); 1469 } else { 1470 nodeflib = objgiven ? refobj->z_nodeflib : false; 1471 if ((objgiven && 1472 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1473 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1474 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1475 (pathname = search_library_path(name, ld_library_path)) != NULL || 1476 (objgiven && 1477 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1478 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1479 (objgiven && !nodeflib && 1480 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1481 return (pathname); 1482 } 1483 1484 if (objgiven && refobj->path != NULL) { 1485 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1486 name, basename(refobj->path)); 1487 } else { 1488 _rtld_error("Shared object \"%s\" not found", name); 1489 } 1490 return NULL; 1491 } 1492 1493 /* 1494 * Given a symbol number in a referencing object, find the corresponding 1495 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1496 * no definition was found. Returns a pointer to the Obj_Entry of the 1497 * defining object via the reference parameter DEFOBJ_OUT. 1498 */ 1499 const Elf_Sym * 1500 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1501 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1502 RtldLockState *lockstate) 1503 { 1504 const Elf_Sym *ref; 1505 const Elf_Sym *def; 1506 const Obj_Entry *defobj; 1507 SymLook req; 1508 const char *name; 1509 int res; 1510 1511 /* 1512 * If we have already found this symbol, get the information from 1513 * the cache. 1514 */ 1515 if (symnum >= refobj->dynsymcount) 1516 return NULL; /* Bad object */ 1517 if (cache != NULL && cache[symnum].sym != NULL) { 1518 *defobj_out = cache[symnum].obj; 1519 return cache[symnum].sym; 1520 } 1521 1522 ref = refobj->symtab + symnum; 1523 name = refobj->strtab + ref->st_name; 1524 def = NULL; 1525 defobj = NULL; 1526 1527 /* 1528 * We don't have to do a full scale lookup if the symbol is local. 1529 * We know it will bind to the instance in this load module; to 1530 * which we already have a pointer (ie ref). By not doing a lookup, 1531 * we not only improve performance, but it also avoids unresolvable 1532 * symbols when local symbols are not in the hash table. This has 1533 * been seen with the ia64 toolchain. 1534 */ 1535 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1536 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1537 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1538 symnum); 1539 } 1540 symlook_init(&req, name); 1541 req.flags = flags; 1542 req.ventry = fetch_ventry(refobj, symnum); 1543 req.lockstate = lockstate; 1544 res = symlook_default(&req, refobj); 1545 if (res == 0) { 1546 def = req.sym_out; 1547 defobj = req.defobj_out; 1548 } 1549 } else { 1550 def = ref; 1551 defobj = refobj; 1552 } 1553 1554 /* 1555 * If we found no definition and the reference is weak, treat the 1556 * symbol as having the value zero. 1557 */ 1558 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1559 def = &sym_zero; 1560 defobj = obj_main; 1561 } 1562 1563 if (def != NULL) { 1564 *defobj_out = defobj; 1565 /* Record the information in the cache to avoid subsequent lookups. */ 1566 if (cache != NULL) { 1567 cache[symnum].sym = def; 1568 cache[symnum].obj = defobj; 1569 } 1570 } else { 1571 if (refobj != &obj_rtld) 1572 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1573 } 1574 return def; 1575 } 1576 1577 /* 1578 * Return the search path from the ldconfig hints file, reading it if 1579 * necessary. If nostdlib is true, then the default search paths are 1580 * not added to result. 1581 * 1582 * Returns NULL if there are problems with the hints file, 1583 * or if the search path there is empty. 1584 */ 1585 static const char * 1586 gethints(bool nostdlib) 1587 { 1588 static char *hints, *filtered_path; 1589 struct elfhints_hdr hdr; 1590 struct fill_search_info_args sargs, hargs; 1591 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1592 struct dl_serpath *SLPpath, *hintpath; 1593 char *p; 1594 unsigned int SLPndx, hintndx, fndx, fcount; 1595 int fd; 1596 size_t flen; 1597 bool skip; 1598 1599 /* First call, read the hints file */ 1600 if (hints == NULL) { 1601 /* Keep from trying again in case the hints file is bad. */ 1602 hints = ""; 1603 1604 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1605 return (NULL); 1606 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1607 hdr.magic != ELFHINTS_MAGIC || 1608 hdr.version != 1) { 1609 close(fd); 1610 return (NULL); 1611 } 1612 p = xmalloc(hdr.dirlistlen + 1); 1613 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1614 read(fd, p, hdr.dirlistlen + 1) != 1615 (ssize_t)hdr.dirlistlen + 1) { 1616 free(p); 1617 close(fd); 1618 return (NULL); 1619 } 1620 hints = p; 1621 close(fd); 1622 } 1623 1624 /* 1625 * If caller agreed to receive list which includes the default 1626 * paths, we are done. Otherwise, if we still did not 1627 * calculated filtered result, do it now. 1628 */ 1629 if (!nostdlib) 1630 return (hints[0] != '\0' ? hints : NULL); 1631 if (filtered_path != NULL) 1632 goto filt_ret; 1633 1634 /* 1635 * Obtain the list of all configured search paths, and the 1636 * list of the default paths. 1637 * 1638 * First estimate the size of the results. 1639 */ 1640 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1641 smeta.dls_cnt = 0; 1642 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1643 hmeta.dls_cnt = 0; 1644 1645 sargs.request = RTLD_DI_SERINFOSIZE; 1646 sargs.serinfo = &smeta; 1647 hargs.request = RTLD_DI_SERINFOSIZE; 1648 hargs.serinfo = &hmeta; 1649 1650 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1651 path_enumerate(p, fill_search_info, &hargs); 1652 1653 SLPinfo = xmalloc(smeta.dls_size); 1654 hintinfo = xmalloc(hmeta.dls_size); 1655 1656 /* 1657 * Next fetch both sets of paths. 1658 */ 1659 sargs.request = RTLD_DI_SERINFO; 1660 sargs.serinfo = SLPinfo; 1661 sargs.serpath = &SLPinfo->dls_serpath[0]; 1662 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1663 1664 hargs.request = RTLD_DI_SERINFO; 1665 hargs.serinfo = hintinfo; 1666 hargs.serpath = &hintinfo->dls_serpath[0]; 1667 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1668 1669 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1670 path_enumerate(p, fill_search_info, &hargs); 1671 1672 /* 1673 * Now calculate the difference between two sets, by excluding 1674 * standard paths from the full set. 1675 */ 1676 fndx = 0; 1677 fcount = 0; 1678 filtered_path = xmalloc(hdr.dirlistlen + 1); 1679 hintpath = &hintinfo->dls_serpath[0]; 1680 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1681 skip = false; 1682 SLPpath = &SLPinfo->dls_serpath[0]; 1683 /* 1684 * Check each standard path against current. 1685 */ 1686 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1687 /* matched, skip the path */ 1688 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1689 skip = true; 1690 break; 1691 } 1692 } 1693 if (skip) 1694 continue; 1695 /* 1696 * Not matched against any standard path, add the path 1697 * to result. Separate consequtive paths with ':'. 1698 */ 1699 if (fcount > 0) { 1700 filtered_path[fndx] = ':'; 1701 fndx++; 1702 } 1703 fcount++; 1704 flen = strlen(hintpath->dls_name); 1705 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1706 fndx += flen; 1707 } 1708 filtered_path[fndx] = '\0'; 1709 1710 free(SLPinfo); 1711 free(hintinfo); 1712 1713 filt_ret: 1714 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1715 } 1716 1717 static void 1718 init_dag(Obj_Entry *root) 1719 { 1720 const Needed_Entry *needed; 1721 const Objlist_Entry *elm; 1722 DoneList donelist; 1723 1724 if (root->dag_inited) 1725 return; 1726 donelist_init(&donelist); 1727 1728 /* Root object belongs to own DAG. */ 1729 objlist_push_tail(&root->dldags, root); 1730 objlist_push_tail(&root->dagmembers, root); 1731 donelist_check(&donelist, root); 1732 1733 /* 1734 * Add dependencies of root object to DAG in breadth order 1735 * by exploiting the fact that each new object get added 1736 * to the tail of the dagmembers list. 1737 */ 1738 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1739 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1740 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1741 continue; 1742 objlist_push_tail(&needed->obj->dldags, root); 1743 objlist_push_tail(&root->dagmembers, needed->obj); 1744 } 1745 } 1746 root->dag_inited = true; 1747 } 1748 1749 static void 1750 process_nodelete(Obj_Entry *root) 1751 { 1752 const Objlist_Entry *elm; 1753 1754 /* 1755 * Walk over object DAG and process every dependent object that 1756 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1757 * which then should have its reference upped separately. 1758 */ 1759 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1760 if (elm->obj != NULL && elm->obj->z_nodelete && 1761 !elm->obj->ref_nodel) { 1762 dbg("obj %s nodelete", elm->obj->path); 1763 init_dag(elm->obj); 1764 ref_dag(elm->obj); 1765 elm->obj->ref_nodel = true; 1766 } 1767 } 1768 } 1769 /* 1770 * Initialize the dynamic linker. The argument is the address at which 1771 * the dynamic linker has been mapped into memory. The primary task of 1772 * this function is to relocate the dynamic linker. 1773 */ 1774 static void 1775 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1776 { 1777 Obj_Entry objtmp; /* Temporary rtld object */ 1778 const Elf_Dyn *dyn_rpath; 1779 const Elf_Dyn *dyn_soname; 1780 const Elf_Dyn *dyn_runpath; 1781 1782 /* 1783 * Conjure up an Obj_Entry structure for the dynamic linker. 1784 * 1785 * The "path" member can't be initialized yet because string constants 1786 * cannot yet be accessed. Below we will set it correctly. 1787 */ 1788 memset(&objtmp, 0, sizeof(objtmp)); 1789 objtmp.path = NULL; 1790 objtmp.rtld = true; 1791 objtmp.mapbase = mapbase; 1792 #ifdef PIC 1793 objtmp.relocbase = mapbase; 1794 #endif 1795 if (RTLD_IS_DYNAMIC()) { 1796 objtmp.dynamic = rtld_dynamic(&objtmp); 1797 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1798 assert(objtmp.needed == NULL); 1799 #if !defined(__mips__) 1800 /* MIPS has a bogus DT_TEXTREL. */ 1801 assert(!objtmp.textrel); 1802 #endif 1803 1804 /* 1805 * Temporarily put the dynamic linker entry into the object list, so 1806 * that symbols can be found. 1807 */ 1808 1809 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1810 } 1811 1812 /* Initialize the object list. */ 1813 obj_tail = &obj_list; 1814 1815 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1816 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1817 1818 if (aux_info[AT_PAGESZ] != NULL) 1819 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1820 if (aux_info[AT_OSRELDATE] != NULL) 1821 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1822 1823 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1824 1825 /* Replace the path with a dynamically allocated copy. */ 1826 obj_rtld.path = xstrdup(PATH_RTLD); 1827 1828 r_debug.r_brk = r_debug_state; 1829 r_debug.r_state = RT_CONSISTENT; 1830 } 1831 1832 /* 1833 * Add the init functions from a needed object list (and its recursive 1834 * needed objects) to "list". This is not used directly; it is a helper 1835 * function for initlist_add_objects(). The write lock must be held 1836 * when this function is called. 1837 */ 1838 static void 1839 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1840 { 1841 /* Recursively process the successor needed objects. */ 1842 if (needed->next != NULL) 1843 initlist_add_neededs(needed->next, list); 1844 1845 /* Process the current needed object. */ 1846 if (needed->obj != NULL) 1847 initlist_add_objects(needed->obj, &needed->obj->next, list); 1848 } 1849 1850 /* 1851 * Scan all of the DAGs rooted in the range of objects from "obj" to 1852 * "tail" and add their init functions to "list". This recurses over 1853 * the DAGs and ensure the proper init ordering such that each object's 1854 * needed libraries are initialized before the object itself. At the 1855 * same time, this function adds the objects to the global finalization 1856 * list "list_fini" in the opposite order. The write lock must be 1857 * held when this function is called. 1858 */ 1859 static void 1860 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1861 { 1862 1863 if (obj->init_scanned || obj->init_done) 1864 return; 1865 obj->init_scanned = true; 1866 1867 /* Recursively process the successor objects. */ 1868 if (&obj->next != tail) 1869 initlist_add_objects(obj->next, tail, list); 1870 1871 /* Recursively process the needed objects. */ 1872 if (obj->needed != NULL) 1873 initlist_add_neededs(obj->needed, list); 1874 if (obj->needed_filtees != NULL) 1875 initlist_add_neededs(obj->needed_filtees, list); 1876 if (obj->needed_aux_filtees != NULL) 1877 initlist_add_neededs(obj->needed_aux_filtees, list); 1878 1879 /* Add the object to the init list. */ 1880 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1881 obj->init_array != (Elf_Addr)NULL) 1882 objlist_push_tail(list, obj); 1883 1884 /* Add the object to the global fini list in the reverse order. */ 1885 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1886 && !obj->on_fini_list) { 1887 objlist_push_head(&list_fini, obj); 1888 obj->on_fini_list = true; 1889 } 1890 } 1891 1892 #ifndef FPTR_TARGET 1893 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1894 #endif 1895 1896 static void 1897 free_needed_filtees(Needed_Entry *n) 1898 { 1899 Needed_Entry *needed, *needed1; 1900 1901 for (needed = n; needed != NULL; needed = needed->next) { 1902 if (needed->obj != NULL) { 1903 dlclose(needed->obj); 1904 needed->obj = NULL; 1905 } 1906 } 1907 for (needed = n; needed != NULL; needed = needed1) { 1908 needed1 = needed->next; 1909 free(needed); 1910 } 1911 } 1912 1913 static void 1914 unload_filtees(Obj_Entry *obj) 1915 { 1916 1917 free_needed_filtees(obj->needed_filtees); 1918 obj->needed_filtees = NULL; 1919 free_needed_filtees(obj->needed_aux_filtees); 1920 obj->needed_aux_filtees = NULL; 1921 obj->filtees_loaded = false; 1922 } 1923 1924 static void 1925 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1926 RtldLockState *lockstate) 1927 { 1928 1929 for (; needed != NULL; needed = needed->next) { 1930 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1931 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1932 RTLD_LOCAL, lockstate); 1933 } 1934 } 1935 1936 static void 1937 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1938 { 1939 1940 lock_restart_for_upgrade(lockstate); 1941 if (!obj->filtees_loaded) { 1942 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1943 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1944 obj->filtees_loaded = true; 1945 } 1946 } 1947 1948 static int 1949 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1950 { 1951 Obj_Entry *obj1; 1952 1953 for (; needed != NULL; needed = needed->next) { 1954 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1955 flags & ~RTLD_LO_NOLOAD); 1956 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1957 return (-1); 1958 } 1959 return (0); 1960 } 1961 1962 /* 1963 * Given a shared object, traverse its list of needed objects, and load 1964 * each of them. Returns 0 on success. Generates an error message and 1965 * returns -1 on failure. 1966 */ 1967 static int 1968 load_needed_objects(Obj_Entry *first, int flags) 1969 { 1970 Obj_Entry *obj; 1971 1972 for (obj = first; obj != NULL; obj = obj->next) { 1973 if (process_needed(obj, obj->needed, flags) == -1) 1974 return (-1); 1975 } 1976 return (0); 1977 } 1978 1979 static int 1980 load_preload_objects(void) 1981 { 1982 char *p = ld_preload; 1983 static const char delim[] = " \t:;"; 1984 1985 if (p == NULL) 1986 return 0; 1987 1988 p += strspn(p, delim); 1989 while (*p != '\0') { 1990 size_t len = strcspn(p, delim); 1991 char savech; 1992 1993 savech = p[len]; 1994 p[len] = '\0'; 1995 if (load_object(p, -1, NULL, 0) == NULL) 1996 return -1; /* XXX - cleanup */ 1997 p[len] = savech; 1998 p += len; 1999 p += strspn(p, delim); 2000 } 2001 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2002 return 0; 2003 } 2004 2005 static const char * 2006 printable_path(const char *path) 2007 { 2008 2009 return (path == NULL ? "<unknown>" : path); 2010 } 2011 2012 /* 2013 * Load a shared object into memory, if it is not already loaded. The 2014 * object may be specified by name or by user-supplied file descriptor 2015 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2016 * duplicate is. 2017 * 2018 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2019 * on failure. 2020 */ 2021 static Obj_Entry * 2022 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2023 { 2024 Obj_Entry *obj; 2025 int fd; 2026 struct stat sb; 2027 char *path; 2028 2029 if (name != NULL) { 2030 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2031 if (object_match_name(obj, name)) 2032 return (obj); 2033 } 2034 2035 path = find_library(name, refobj); 2036 if (path == NULL) 2037 return (NULL); 2038 } else 2039 path = NULL; 2040 2041 /* 2042 * If we didn't find a match by pathname, or the name is not 2043 * supplied, open the file and check again by device and inode. 2044 * This avoids false mismatches caused by multiple links or ".." 2045 * in pathnames. 2046 * 2047 * To avoid a race, we open the file and use fstat() rather than 2048 * using stat(). 2049 */ 2050 fd = -1; 2051 if (fd_u == -1) { 2052 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2053 _rtld_error("Cannot open \"%s\"", path); 2054 free(path); 2055 return (NULL); 2056 } 2057 } else { 2058 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2059 if (fd == -1) { 2060 _rtld_error("Cannot dup fd"); 2061 free(path); 2062 return (NULL); 2063 } 2064 } 2065 if (fstat(fd, &sb) == -1) { 2066 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2067 close(fd); 2068 free(path); 2069 return NULL; 2070 } 2071 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2072 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2073 break; 2074 if (obj != NULL && name != NULL) { 2075 object_add_name(obj, name); 2076 free(path); 2077 close(fd); 2078 return obj; 2079 } 2080 if (flags & RTLD_LO_NOLOAD) { 2081 free(path); 2082 close(fd); 2083 return (NULL); 2084 } 2085 2086 /* First use of this object, so we must map it in */ 2087 obj = do_load_object(fd, name, path, &sb, flags); 2088 if (obj == NULL) 2089 free(path); 2090 close(fd); 2091 2092 return obj; 2093 } 2094 2095 static Obj_Entry * 2096 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2097 int flags) 2098 { 2099 Obj_Entry *obj; 2100 struct statfs fs; 2101 2102 /* 2103 * but first, make sure that environment variables haven't been 2104 * used to circumvent the noexec flag on a filesystem. 2105 */ 2106 if (dangerous_ld_env) { 2107 if (fstatfs(fd, &fs) != 0) { 2108 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2109 return NULL; 2110 } 2111 if (fs.f_flags & MNT_NOEXEC) { 2112 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2113 return NULL; 2114 } 2115 } 2116 dbg("loading \"%s\"", printable_path(path)); 2117 obj = map_object(fd, printable_path(path), sbp); 2118 if (obj == NULL) 2119 return NULL; 2120 2121 /* 2122 * If DT_SONAME is present in the object, digest_dynamic2 already 2123 * added it to the object names. 2124 */ 2125 if (name != NULL) 2126 object_add_name(obj, name); 2127 obj->path = path; 2128 digest_dynamic(obj, 0); 2129 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2130 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2131 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2132 RTLD_LO_DLOPEN) { 2133 dbg("refusing to load non-loadable \"%s\"", obj->path); 2134 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2135 munmap(obj->mapbase, obj->mapsize); 2136 obj_free(obj); 2137 return (NULL); 2138 } 2139 2140 *obj_tail = obj; 2141 obj_tail = &obj->next; 2142 obj_count++; 2143 obj_loads++; 2144 linkmap_add(obj); /* for GDB & dlinfo() */ 2145 max_stack_flags |= obj->stack_flags; 2146 2147 dbg(" %p .. %p: %s", obj->mapbase, 2148 obj->mapbase + obj->mapsize - 1, obj->path); 2149 if (obj->textrel) 2150 dbg(" WARNING: %s has impure text", obj->path); 2151 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2152 obj->path); 2153 2154 return obj; 2155 } 2156 2157 static Obj_Entry * 2158 obj_from_addr(const void *addr) 2159 { 2160 Obj_Entry *obj; 2161 2162 for (obj = obj_list; obj != NULL; obj = obj->next) { 2163 if (addr < (void *) obj->mapbase) 2164 continue; 2165 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2166 return obj; 2167 } 2168 return NULL; 2169 } 2170 2171 static void 2172 preinit_main(void) 2173 { 2174 Elf_Addr *preinit_addr; 2175 int index; 2176 2177 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2178 if (preinit_addr == NULL) 2179 return; 2180 2181 for (index = 0; index < obj_main->preinit_array_num; index++) { 2182 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2183 dbg("calling preinit function for %s at %p", obj_main->path, 2184 (void *)preinit_addr[index]); 2185 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2186 0, 0, obj_main->path); 2187 call_init_pointer(obj_main, preinit_addr[index]); 2188 } 2189 } 2190 } 2191 2192 /* 2193 * Call the finalization functions for each of the objects in "list" 2194 * belonging to the DAG of "root" and referenced once. If NULL "root" 2195 * is specified, every finalization function will be called regardless 2196 * of the reference count and the list elements won't be freed. All of 2197 * the objects are expected to have non-NULL fini functions. 2198 */ 2199 static void 2200 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2201 { 2202 Objlist_Entry *elm; 2203 char *saved_msg; 2204 Elf_Addr *fini_addr; 2205 int index; 2206 2207 assert(root == NULL || root->refcount == 1); 2208 2209 /* 2210 * Preserve the current error message since a fini function might 2211 * call into the dynamic linker and overwrite it. 2212 */ 2213 saved_msg = errmsg_save(); 2214 do { 2215 STAILQ_FOREACH(elm, list, link) { 2216 if (root != NULL && (elm->obj->refcount != 1 || 2217 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2218 continue; 2219 /* Remove object from fini list to prevent recursive invocation. */ 2220 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2221 /* 2222 * XXX: If a dlopen() call references an object while the 2223 * fini function is in progress, we might end up trying to 2224 * unload the referenced object in dlclose() or the object 2225 * won't be unloaded although its fini function has been 2226 * called. 2227 */ 2228 lock_release(rtld_bind_lock, lockstate); 2229 2230 /* 2231 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2232 * When this happens, DT_FINI_ARRAY is processed first. 2233 */ 2234 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2235 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2236 for (index = elm->obj->fini_array_num - 1; index >= 0; 2237 index--) { 2238 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2239 dbg("calling fini function for %s at %p", 2240 elm->obj->path, (void *)fini_addr[index]); 2241 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2242 (void *)fini_addr[index], 0, 0, elm->obj->path); 2243 call_initfini_pointer(elm->obj, fini_addr[index]); 2244 } 2245 } 2246 } 2247 if (elm->obj->fini != (Elf_Addr)NULL) { 2248 dbg("calling fini function for %s at %p", elm->obj->path, 2249 (void *)elm->obj->fini); 2250 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2251 0, 0, elm->obj->path); 2252 call_initfini_pointer(elm->obj, elm->obj->fini); 2253 } 2254 wlock_acquire(rtld_bind_lock, lockstate); 2255 /* No need to free anything if process is going down. */ 2256 if (root != NULL) 2257 free(elm); 2258 /* 2259 * We must restart the list traversal after every fini call 2260 * because a dlclose() call from the fini function or from 2261 * another thread might have modified the reference counts. 2262 */ 2263 break; 2264 } 2265 } while (elm != NULL); 2266 errmsg_restore(saved_msg); 2267 } 2268 2269 /* 2270 * Call the initialization functions for each of the objects in 2271 * "list". All of the objects are expected to have non-NULL init 2272 * functions. 2273 */ 2274 static void 2275 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2276 { 2277 Objlist_Entry *elm; 2278 Obj_Entry *obj; 2279 char *saved_msg; 2280 Elf_Addr *init_addr; 2281 int index; 2282 2283 /* 2284 * Clean init_scanned flag so that objects can be rechecked and 2285 * possibly initialized earlier if any of vectors called below 2286 * cause the change by using dlopen. 2287 */ 2288 for (obj = obj_list; obj != NULL; obj = obj->next) 2289 obj->init_scanned = false; 2290 2291 /* 2292 * Preserve the current error message since an init function might 2293 * call into the dynamic linker and overwrite it. 2294 */ 2295 saved_msg = errmsg_save(); 2296 STAILQ_FOREACH(elm, list, link) { 2297 if (elm->obj->init_done) /* Initialized early. */ 2298 continue; 2299 /* 2300 * Race: other thread might try to use this object before current 2301 * one completes the initilization. Not much can be done here 2302 * without better locking. 2303 */ 2304 elm->obj->init_done = true; 2305 lock_release(rtld_bind_lock, lockstate); 2306 2307 /* 2308 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2309 * When this happens, DT_INIT is processed first. 2310 */ 2311 if (elm->obj->init != (Elf_Addr)NULL) { 2312 dbg("calling init function for %s at %p", elm->obj->path, 2313 (void *)elm->obj->init); 2314 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2315 0, 0, elm->obj->path); 2316 call_initfini_pointer(elm->obj, elm->obj->init); 2317 } 2318 init_addr = (Elf_Addr *)elm->obj->init_array; 2319 if (init_addr != NULL) { 2320 for (index = 0; index < elm->obj->init_array_num; index++) { 2321 if (init_addr[index] != 0 && init_addr[index] != 1) { 2322 dbg("calling init function for %s at %p", elm->obj->path, 2323 (void *)init_addr[index]); 2324 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2325 (void *)init_addr[index], 0, 0, elm->obj->path); 2326 call_init_pointer(elm->obj, init_addr[index]); 2327 } 2328 } 2329 } 2330 wlock_acquire(rtld_bind_lock, lockstate); 2331 } 2332 errmsg_restore(saved_msg); 2333 } 2334 2335 static void 2336 objlist_clear(Objlist *list) 2337 { 2338 Objlist_Entry *elm; 2339 2340 while (!STAILQ_EMPTY(list)) { 2341 elm = STAILQ_FIRST(list); 2342 STAILQ_REMOVE_HEAD(list, link); 2343 free(elm); 2344 } 2345 } 2346 2347 static Objlist_Entry * 2348 objlist_find(Objlist *list, const Obj_Entry *obj) 2349 { 2350 Objlist_Entry *elm; 2351 2352 STAILQ_FOREACH(elm, list, link) 2353 if (elm->obj == obj) 2354 return elm; 2355 return NULL; 2356 } 2357 2358 static void 2359 objlist_init(Objlist *list) 2360 { 2361 STAILQ_INIT(list); 2362 } 2363 2364 static void 2365 objlist_push_head(Objlist *list, Obj_Entry *obj) 2366 { 2367 Objlist_Entry *elm; 2368 2369 elm = NEW(Objlist_Entry); 2370 elm->obj = obj; 2371 STAILQ_INSERT_HEAD(list, elm, link); 2372 } 2373 2374 static void 2375 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2376 { 2377 Objlist_Entry *elm; 2378 2379 elm = NEW(Objlist_Entry); 2380 elm->obj = obj; 2381 STAILQ_INSERT_TAIL(list, elm, link); 2382 } 2383 2384 static void 2385 objlist_remove(Objlist *list, Obj_Entry *obj) 2386 { 2387 Objlist_Entry *elm; 2388 2389 if ((elm = objlist_find(list, obj)) != NULL) { 2390 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2391 free(elm); 2392 } 2393 } 2394 2395 /* 2396 * Relocate dag rooted in the specified object. 2397 * Returns 0 on success, or -1 on failure. 2398 */ 2399 2400 static int 2401 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2402 int flags, RtldLockState *lockstate) 2403 { 2404 Objlist_Entry *elm; 2405 int error; 2406 2407 error = 0; 2408 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2409 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2410 lockstate); 2411 if (error == -1) 2412 break; 2413 } 2414 return (error); 2415 } 2416 2417 /* 2418 * Relocate single object. 2419 * Returns 0 on success, or -1 on failure. 2420 */ 2421 static int 2422 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2423 int flags, RtldLockState *lockstate) 2424 { 2425 2426 if (obj->relocated) 2427 return (0); 2428 obj->relocated = true; 2429 if (obj != rtldobj) 2430 dbg("relocating \"%s\"", obj->path); 2431 2432 if (obj->symtab == NULL || obj->strtab == NULL || 2433 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2434 _rtld_error("%s: Shared object has no run-time symbol table", 2435 obj->path); 2436 return (-1); 2437 } 2438 2439 if (obj->textrel) { 2440 /* There are relocations to the write-protected text segment. */ 2441 if (mprotect(obj->mapbase, obj->textsize, 2442 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2443 _rtld_error("%s: Cannot write-enable text segment: %s", 2444 obj->path, rtld_strerror(errno)); 2445 return (-1); 2446 } 2447 } 2448 2449 /* Process the non-PLT relocations. */ 2450 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2451 return (-1); 2452 2453 if (obj->textrel) { /* Re-protected the text segment. */ 2454 if (mprotect(obj->mapbase, obj->textsize, 2455 PROT_READ|PROT_EXEC) == -1) { 2456 _rtld_error("%s: Cannot write-protect text segment: %s", 2457 obj->path, rtld_strerror(errno)); 2458 return (-1); 2459 } 2460 } 2461 2462 2463 /* Set the special PLT or GOT entries. */ 2464 init_pltgot(obj); 2465 2466 /* Process the PLT relocations. */ 2467 if (reloc_plt(obj) == -1) 2468 return (-1); 2469 /* Relocate the jump slots if we are doing immediate binding. */ 2470 if (obj->bind_now || bind_now) 2471 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2472 return (-1); 2473 2474 if (obj->relro_size > 0) { 2475 if (mprotect(obj->relro_page, obj->relro_size, 2476 PROT_READ) == -1) { 2477 _rtld_error("%s: Cannot enforce relro protection: %s", 2478 obj->path, rtld_strerror(errno)); 2479 return (-1); 2480 } 2481 } 2482 2483 /* 2484 * Set up the magic number and version in the Obj_Entry. These 2485 * were checked in the crt1.o from the original ElfKit, so we 2486 * set them for backward compatibility. 2487 */ 2488 obj->magic = RTLD_MAGIC; 2489 obj->version = RTLD_VERSION; 2490 2491 return (0); 2492 } 2493 2494 /* 2495 * Relocate newly-loaded shared objects. The argument is a pointer to 2496 * the Obj_Entry for the first such object. All objects from the first 2497 * to the end of the list of objects are relocated. Returns 0 on success, 2498 * or -1 on failure. 2499 */ 2500 static int 2501 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2502 int flags, RtldLockState *lockstate) 2503 { 2504 Obj_Entry *obj; 2505 int error; 2506 2507 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2508 error = relocate_object(obj, bind_now, rtldobj, flags, 2509 lockstate); 2510 if (error == -1) 2511 break; 2512 } 2513 return (error); 2514 } 2515 2516 /* 2517 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2518 * referencing STT_GNU_IFUNC symbols is postponed till the other 2519 * relocations are done. The indirect functions specified as 2520 * ifunc are allowed to call other symbols, so we need to have 2521 * objects relocated before asking for resolution from indirects. 2522 * 2523 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2524 * instead of the usual lazy handling of PLT slots. It is 2525 * consistent with how GNU does it. 2526 */ 2527 static int 2528 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2529 RtldLockState *lockstate) 2530 { 2531 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2532 return (-1); 2533 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2534 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2535 return (-1); 2536 return (0); 2537 } 2538 2539 static int 2540 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2541 RtldLockState *lockstate) 2542 { 2543 Obj_Entry *obj; 2544 2545 for (obj = first; obj != NULL; obj = obj->next) { 2546 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2547 return (-1); 2548 } 2549 return (0); 2550 } 2551 2552 static int 2553 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2554 RtldLockState *lockstate) 2555 { 2556 Objlist_Entry *elm; 2557 2558 STAILQ_FOREACH(elm, list, link) { 2559 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2560 lockstate) == -1) 2561 return (-1); 2562 } 2563 return (0); 2564 } 2565 2566 /* 2567 * Cleanup procedure. It will be called (by the atexit mechanism) just 2568 * before the process exits. 2569 */ 2570 static void 2571 rtld_exit(void) 2572 { 2573 RtldLockState lockstate; 2574 2575 wlock_acquire(rtld_bind_lock, &lockstate); 2576 dbg("rtld_exit()"); 2577 objlist_call_fini(&list_fini, NULL, &lockstate); 2578 /* No need to remove the items from the list, since we are exiting. */ 2579 if (!libmap_disable) 2580 lm_fini(); 2581 lock_release(rtld_bind_lock, &lockstate); 2582 } 2583 2584 static void * 2585 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2586 { 2587 #ifdef COMPAT_32BIT 2588 const char *trans; 2589 #endif 2590 if (path == NULL) 2591 return (NULL); 2592 2593 path += strspn(path, ":;"); 2594 while (*path != '\0') { 2595 size_t len; 2596 char *res; 2597 2598 len = strcspn(path, ":;"); 2599 #ifdef COMPAT_32BIT 2600 trans = lm_findn(NULL, path, len); 2601 if (trans) 2602 res = callback(trans, strlen(trans), arg); 2603 else 2604 #endif 2605 res = callback(path, len, arg); 2606 2607 if (res != NULL) 2608 return (res); 2609 2610 path += len; 2611 path += strspn(path, ":;"); 2612 } 2613 2614 return (NULL); 2615 } 2616 2617 struct try_library_args { 2618 const char *name; 2619 size_t namelen; 2620 char *buffer; 2621 size_t buflen; 2622 }; 2623 2624 static void * 2625 try_library_path(const char *dir, size_t dirlen, void *param) 2626 { 2627 struct try_library_args *arg; 2628 2629 arg = param; 2630 if (*dir == '/' || trust) { 2631 char *pathname; 2632 2633 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2634 return (NULL); 2635 2636 pathname = arg->buffer; 2637 strncpy(pathname, dir, dirlen); 2638 pathname[dirlen] = '/'; 2639 strcpy(pathname + dirlen + 1, arg->name); 2640 2641 dbg(" Trying \"%s\"", pathname); 2642 if (access(pathname, F_OK) == 0) { /* We found it */ 2643 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2644 strcpy(pathname, arg->buffer); 2645 return (pathname); 2646 } 2647 } 2648 return (NULL); 2649 } 2650 2651 static char * 2652 search_library_path(const char *name, const char *path) 2653 { 2654 char *p; 2655 struct try_library_args arg; 2656 2657 if (path == NULL) 2658 return NULL; 2659 2660 arg.name = name; 2661 arg.namelen = strlen(name); 2662 arg.buffer = xmalloc(PATH_MAX); 2663 arg.buflen = PATH_MAX; 2664 2665 p = path_enumerate(path, try_library_path, &arg); 2666 2667 free(arg.buffer); 2668 2669 return (p); 2670 } 2671 2672 int 2673 dlclose(void *handle) 2674 { 2675 Obj_Entry *root; 2676 RtldLockState lockstate; 2677 2678 wlock_acquire(rtld_bind_lock, &lockstate); 2679 root = dlcheck(handle); 2680 if (root == NULL) { 2681 lock_release(rtld_bind_lock, &lockstate); 2682 return -1; 2683 } 2684 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2685 root->path); 2686 2687 /* Unreference the object and its dependencies. */ 2688 root->dl_refcount--; 2689 2690 if (root->refcount == 1) { 2691 /* 2692 * The object will be no longer referenced, so we must unload it. 2693 * First, call the fini functions. 2694 */ 2695 objlist_call_fini(&list_fini, root, &lockstate); 2696 2697 unref_dag(root); 2698 2699 /* Finish cleaning up the newly-unreferenced objects. */ 2700 GDB_STATE(RT_DELETE,&root->linkmap); 2701 unload_object(root); 2702 GDB_STATE(RT_CONSISTENT,NULL); 2703 } else 2704 unref_dag(root); 2705 2706 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2707 lock_release(rtld_bind_lock, &lockstate); 2708 return 0; 2709 } 2710 2711 char * 2712 dlerror(void) 2713 { 2714 char *msg = error_message; 2715 error_message = NULL; 2716 return msg; 2717 } 2718 2719 /* 2720 * This function is deprecated and has no effect. 2721 */ 2722 void 2723 dllockinit(void *context, 2724 void *(*lock_create)(void *context), 2725 void (*rlock_acquire)(void *lock), 2726 void (*wlock_acquire)(void *lock), 2727 void (*lock_release)(void *lock), 2728 void (*lock_destroy)(void *lock), 2729 void (*context_destroy)(void *context)) 2730 { 2731 static void *cur_context; 2732 static void (*cur_context_destroy)(void *); 2733 2734 /* Just destroy the context from the previous call, if necessary. */ 2735 if (cur_context_destroy != NULL) 2736 cur_context_destroy(cur_context); 2737 cur_context = context; 2738 cur_context_destroy = context_destroy; 2739 } 2740 2741 void * 2742 dlopen(const char *name, int mode) 2743 { 2744 2745 return (rtld_dlopen(name, -1, mode)); 2746 } 2747 2748 void * 2749 fdlopen(int fd, int mode) 2750 { 2751 2752 return (rtld_dlopen(NULL, fd, mode)); 2753 } 2754 2755 static void * 2756 rtld_dlopen(const char *name, int fd, int mode) 2757 { 2758 RtldLockState lockstate; 2759 int lo_flags; 2760 2761 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2762 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2763 if (ld_tracing != NULL) { 2764 rlock_acquire(rtld_bind_lock, &lockstate); 2765 if (sigsetjmp(lockstate.env, 0) != 0) 2766 lock_upgrade(rtld_bind_lock, &lockstate); 2767 environ = (char **)*get_program_var_addr("environ", &lockstate); 2768 lock_release(rtld_bind_lock, &lockstate); 2769 } 2770 lo_flags = RTLD_LO_DLOPEN; 2771 if (mode & RTLD_NODELETE) 2772 lo_flags |= RTLD_LO_NODELETE; 2773 if (mode & RTLD_NOLOAD) 2774 lo_flags |= RTLD_LO_NOLOAD; 2775 if (ld_tracing != NULL) 2776 lo_flags |= RTLD_LO_TRACE; 2777 2778 return (dlopen_object(name, fd, obj_main, lo_flags, 2779 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2780 } 2781 2782 static void 2783 dlopen_cleanup(Obj_Entry *obj) 2784 { 2785 2786 obj->dl_refcount--; 2787 unref_dag(obj); 2788 if (obj->refcount == 0) 2789 unload_object(obj); 2790 } 2791 2792 static Obj_Entry * 2793 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2794 int mode, RtldLockState *lockstate) 2795 { 2796 Obj_Entry **old_obj_tail; 2797 Obj_Entry *obj; 2798 Objlist initlist; 2799 RtldLockState mlockstate; 2800 int result; 2801 2802 objlist_init(&initlist); 2803 2804 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2805 wlock_acquire(rtld_bind_lock, &mlockstate); 2806 lockstate = &mlockstate; 2807 } 2808 GDB_STATE(RT_ADD,NULL); 2809 2810 old_obj_tail = obj_tail; 2811 obj = NULL; 2812 if (name == NULL && fd == -1) { 2813 obj = obj_main; 2814 obj->refcount++; 2815 } else { 2816 obj = load_object(name, fd, refobj, lo_flags); 2817 } 2818 2819 if (obj) { 2820 obj->dl_refcount++; 2821 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2822 objlist_push_tail(&list_global, obj); 2823 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2824 assert(*old_obj_tail == obj); 2825 result = load_needed_objects(obj, 2826 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2827 init_dag(obj); 2828 ref_dag(obj); 2829 if (result != -1) 2830 result = rtld_verify_versions(&obj->dagmembers); 2831 if (result != -1 && ld_tracing) 2832 goto trace; 2833 if (result == -1 || relocate_object_dag(obj, 2834 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2835 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2836 lockstate) == -1) { 2837 dlopen_cleanup(obj); 2838 obj = NULL; 2839 } else if (lo_flags & RTLD_LO_EARLY) { 2840 /* 2841 * Do not call the init functions for early loaded 2842 * filtees. The image is still not initialized enough 2843 * for them to work. 2844 * 2845 * Our object is found by the global object list and 2846 * will be ordered among all init calls done right 2847 * before transferring control to main. 2848 */ 2849 } else { 2850 /* Make list of init functions to call. */ 2851 initlist_add_objects(obj, &obj->next, &initlist); 2852 } 2853 /* 2854 * Process all no_delete objects here, given them own 2855 * DAGs to prevent their dependencies from being unloaded. 2856 * This has to be done after we have loaded all of the 2857 * dependencies, so that we do not miss any. 2858 */ 2859 if (obj != NULL) 2860 process_nodelete(obj); 2861 } else { 2862 /* 2863 * Bump the reference counts for objects on this DAG. If 2864 * this is the first dlopen() call for the object that was 2865 * already loaded as a dependency, initialize the dag 2866 * starting at it. 2867 */ 2868 init_dag(obj); 2869 ref_dag(obj); 2870 2871 if ((lo_flags & RTLD_LO_TRACE) != 0) 2872 goto trace; 2873 } 2874 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2875 obj->z_nodelete) && !obj->ref_nodel) { 2876 dbg("obj %s nodelete", obj->path); 2877 ref_dag(obj); 2878 obj->z_nodelete = obj->ref_nodel = true; 2879 } 2880 } 2881 2882 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2883 name); 2884 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2885 2886 if (!(lo_flags & RTLD_LO_EARLY)) { 2887 map_stacks_exec(lockstate); 2888 } 2889 2890 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2891 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2892 lockstate) == -1) { 2893 objlist_clear(&initlist); 2894 dlopen_cleanup(obj); 2895 if (lockstate == &mlockstate) 2896 lock_release(rtld_bind_lock, lockstate); 2897 return (NULL); 2898 } 2899 2900 if (!(lo_flags & RTLD_LO_EARLY)) { 2901 /* Call the init functions. */ 2902 objlist_call_init(&initlist, lockstate); 2903 } 2904 objlist_clear(&initlist); 2905 if (lockstate == &mlockstate) 2906 lock_release(rtld_bind_lock, lockstate); 2907 return obj; 2908 trace: 2909 trace_loaded_objects(obj); 2910 if (lockstate == &mlockstate) 2911 lock_release(rtld_bind_lock, lockstate); 2912 exit(0); 2913 } 2914 2915 static void * 2916 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2917 int flags) 2918 { 2919 DoneList donelist; 2920 const Obj_Entry *obj, *defobj; 2921 const Elf_Sym *def; 2922 SymLook req; 2923 RtldLockState lockstate; 2924 #ifndef __ia64__ 2925 tls_index ti; 2926 #endif 2927 int res; 2928 2929 def = NULL; 2930 defobj = NULL; 2931 symlook_init(&req, name); 2932 req.ventry = ve; 2933 req.flags = flags | SYMLOOK_IN_PLT; 2934 req.lockstate = &lockstate; 2935 2936 rlock_acquire(rtld_bind_lock, &lockstate); 2937 if (sigsetjmp(lockstate.env, 0) != 0) 2938 lock_upgrade(rtld_bind_lock, &lockstate); 2939 if (handle == NULL || handle == RTLD_NEXT || 2940 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2941 2942 if ((obj = obj_from_addr(retaddr)) == NULL) { 2943 _rtld_error("Cannot determine caller's shared object"); 2944 lock_release(rtld_bind_lock, &lockstate); 2945 return NULL; 2946 } 2947 if (handle == NULL) { /* Just the caller's shared object. */ 2948 res = symlook_obj(&req, obj); 2949 if (res == 0) { 2950 def = req.sym_out; 2951 defobj = req.defobj_out; 2952 } 2953 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2954 handle == RTLD_SELF) { /* ... caller included */ 2955 if (handle == RTLD_NEXT) 2956 obj = obj->next; 2957 for (; obj != NULL; obj = obj->next) { 2958 res = symlook_obj(&req, obj); 2959 if (res == 0) { 2960 if (def == NULL || 2961 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2962 def = req.sym_out; 2963 defobj = req.defobj_out; 2964 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2965 break; 2966 } 2967 } 2968 } 2969 /* 2970 * Search the dynamic linker itself, and possibly resolve the 2971 * symbol from there. This is how the application links to 2972 * dynamic linker services such as dlopen. 2973 */ 2974 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2975 res = symlook_obj(&req, &obj_rtld); 2976 if (res == 0) { 2977 def = req.sym_out; 2978 defobj = req.defobj_out; 2979 } 2980 } 2981 } else { 2982 assert(handle == RTLD_DEFAULT); 2983 res = symlook_default(&req, obj); 2984 if (res == 0) { 2985 defobj = req.defobj_out; 2986 def = req.sym_out; 2987 } 2988 } 2989 } else { 2990 if ((obj = dlcheck(handle)) == NULL) { 2991 lock_release(rtld_bind_lock, &lockstate); 2992 return NULL; 2993 } 2994 2995 donelist_init(&donelist); 2996 if (obj->mainprog) { 2997 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 2998 res = symlook_global(&req, &donelist); 2999 if (res == 0) { 3000 def = req.sym_out; 3001 defobj = req.defobj_out; 3002 } 3003 /* 3004 * Search the dynamic linker itself, and possibly resolve the 3005 * symbol from there. This is how the application links to 3006 * dynamic linker services such as dlopen. 3007 */ 3008 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3009 res = symlook_obj(&req, &obj_rtld); 3010 if (res == 0) { 3011 def = req.sym_out; 3012 defobj = req.defobj_out; 3013 } 3014 } 3015 } 3016 else { 3017 /* Search the whole DAG rooted at the given object. */ 3018 res = symlook_list(&req, &obj->dagmembers, &donelist); 3019 if (res == 0) { 3020 def = req.sym_out; 3021 defobj = req.defobj_out; 3022 } 3023 } 3024 } 3025 3026 if (def != NULL) { 3027 lock_release(rtld_bind_lock, &lockstate); 3028 3029 /* 3030 * The value required by the caller is derived from the value 3031 * of the symbol. For the ia64 architecture, we need to 3032 * construct a function descriptor which the caller can use to 3033 * call the function with the right 'gp' value. For other 3034 * architectures and for non-functions, the value is simply 3035 * the relocated value of the symbol. 3036 */ 3037 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3038 return (make_function_pointer(def, defobj)); 3039 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3040 return (rtld_resolve_ifunc(defobj, def)); 3041 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3042 #ifdef __ia64__ 3043 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3044 #else 3045 ti.ti_module = defobj->tlsindex; 3046 ti.ti_offset = def->st_value; 3047 return (__tls_get_addr(&ti)); 3048 #endif 3049 } else 3050 return (defobj->relocbase + def->st_value); 3051 } 3052 3053 _rtld_error("Undefined symbol \"%s\"", name); 3054 lock_release(rtld_bind_lock, &lockstate); 3055 return NULL; 3056 } 3057 3058 void * 3059 dlsym(void *handle, const char *name) 3060 { 3061 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3062 SYMLOOK_DLSYM); 3063 } 3064 3065 dlfunc_t 3066 dlfunc(void *handle, const char *name) 3067 { 3068 union { 3069 void *d; 3070 dlfunc_t f; 3071 } rv; 3072 3073 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3074 SYMLOOK_DLSYM); 3075 return (rv.f); 3076 } 3077 3078 void * 3079 dlvsym(void *handle, const char *name, const char *version) 3080 { 3081 Ver_Entry ventry; 3082 3083 ventry.name = version; 3084 ventry.file = NULL; 3085 ventry.hash = elf_hash(version); 3086 ventry.flags= 0; 3087 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3088 SYMLOOK_DLSYM); 3089 } 3090 3091 int 3092 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3093 { 3094 const Obj_Entry *obj; 3095 RtldLockState lockstate; 3096 3097 rlock_acquire(rtld_bind_lock, &lockstate); 3098 obj = obj_from_addr(addr); 3099 if (obj == NULL) { 3100 _rtld_error("No shared object contains address"); 3101 lock_release(rtld_bind_lock, &lockstate); 3102 return (0); 3103 } 3104 rtld_fill_dl_phdr_info(obj, phdr_info); 3105 lock_release(rtld_bind_lock, &lockstate); 3106 return (1); 3107 } 3108 3109 int 3110 dladdr(const void *addr, Dl_info *info) 3111 { 3112 const Obj_Entry *obj; 3113 const Elf_Sym *def; 3114 void *symbol_addr; 3115 unsigned long symoffset; 3116 RtldLockState lockstate; 3117 3118 rlock_acquire(rtld_bind_lock, &lockstate); 3119 obj = obj_from_addr(addr); 3120 if (obj == NULL) { 3121 _rtld_error("No shared object contains address"); 3122 lock_release(rtld_bind_lock, &lockstate); 3123 return 0; 3124 } 3125 info->dli_fname = obj->path; 3126 info->dli_fbase = obj->mapbase; 3127 info->dli_saddr = (void *)0; 3128 info->dli_sname = NULL; 3129 3130 /* 3131 * Walk the symbol list looking for the symbol whose address is 3132 * closest to the address sent in. 3133 */ 3134 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3135 def = obj->symtab + symoffset; 3136 3137 /* 3138 * For skip the symbol if st_shndx is either SHN_UNDEF or 3139 * SHN_COMMON. 3140 */ 3141 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3142 continue; 3143 3144 /* 3145 * If the symbol is greater than the specified address, or if it 3146 * is further away from addr than the current nearest symbol, 3147 * then reject it. 3148 */ 3149 symbol_addr = obj->relocbase + def->st_value; 3150 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3151 continue; 3152 3153 /* Update our idea of the nearest symbol. */ 3154 info->dli_sname = obj->strtab + def->st_name; 3155 info->dli_saddr = symbol_addr; 3156 3157 /* Exact match? */ 3158 if (info->dli_saddr == addr) 3159 break; 3160 } 3161 lock_release(rtld_bind_lock, &lockstate); 3162 return 1; 3163 } 3164 3165 int 3166 dlinfo(void *handle, int request, void *p) 3167 { 3168 const Obj_Entry *obj; 3169 RtldLockState lockstate; 3170 int error; 3171 3172 rlock_acquire(rtld_bind_lock, &lockstate); 3173 3174 if (handle == NULL || handle == RTLD_SELF) { 3175 void *retaddr; 3176 3177 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3178 if ((obj = obj_from_addr(retaddr)) == NULL) 3179 _rtld_error("Cannot determine caller's shared object"); 3180 } else 3181 obj = dlcheck(handle); 3182 3183 if (obj == NULL) { 3184 lock_release(rtld_bind_lock, &lockstate); 3185 return (-1); 3186 } 3187 3188 error = 0; 3189 switch (request) { 3190 case RTLD_DI_LINKMAP: 3191 *((struct link_map const **)p) = &obj->linkmap; 3192 break; 3193 case RTLD_DI_ORIGIN: 3194 error = rtld_dirname(obj->path, p); 3195 break; 3196 3197 case RTLD_DI_SERINFOSIZE: 3198 case RTLD_DI_SERINFO: 3199 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3200 break; 3201 3202 default: 3203 _rtld_error("Invalid request %d passed to dlinfo()", request); 3204 error = -1; 3205 } 3206 3207 lock_release(rtld_bind_lock, &lockstate); 3208 3209 return (error); 3210 } 3211 3212 static void 3213 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3214 { 3215 3216 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3217 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 3218 STAILQ_FIRST(&obj->names)->name : obj->path; 3219 phdr_info->dlpi_phdr = obj->phdr; 3220 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3221 phdr_info->dlpi_tls_modid = obj->tlsindex; 3222 phdr_info->dlpi_tls_data = obj->tlsinit; 3223 phdr_info->dlpi_adds = obj_loads; 3224 phdr_info->dlpi_subs = obj_loads - obj_count; 3225 } 3226 3227 int 3228 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3229 { 3230 struct dl_phdr_info phdr_info; 3231 const Obj_Entry *obj; 3232 RtldLockState bind_lockstate, phdr_lockstate; 3233 int error; 3234 3235 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3236 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3237 3238 error = 0; 3239 3240 for (obj = obj_list; obj != NULL; obj = obj->next) { 3241 rtld_fill_dl_phdr_info(obj, &phdr_info); 3242 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3243 break; 3244 3245 } 3246 lock_release(rtld_bind_lock, &bind_lockstate); 3247 lock_release(rtld_phdr_lock, &phdr_lockstate); 3248 3249 return (error); 3250 } 3251 3252 static void * 3253 fill_search_info(const char *dir, size_t dirlen, void *param) 3254 { 3255 struct fill_search_info_args *arg; 3256 3257 arg = param; 3258 3259 if (arg->request == RTLD_DI_SERINFOSIZE) { 3260 arg->serinfo->dls_cnt ++; 3261 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3262 } else { 3263 struct dl_serpath *s_entry; 3264 3265 s_entry = arg->serpath; 3266 s_entry->dls_name = arg->strspace; 3267 s_entry->dls_flags = arg->flags; 3268 3269 strncpy(arg->strspace, dir, dirlen); 3270 arg->strspace[dirlen] = '\0'; 3271 3272 arg->strspace += dirlen + 1; 3273 arg->serpath++; 3274 } 3275 3276 return (NULL); 3277 } 3278 3279 static int 3280 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3281 { 3282 struct dl_serinfo _info; 3283 struct fill_search_info_args args; 3284 3285 args.request = RTLD_DI_SERINFOSIZE; 3286 args.serinfo = &_info; 3287 3288 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3289 _info.dls_cnt = 0; 3290 3291 path_enumerate(obj->rpath, fill_search_info, &args); 3292 path_enumerate(ld_library_path, fill_search_info, &args); 3293 path_enumerate(obj->runpath, fill_search_info, &args); 3294 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3295 if (!obj->z_nodeflib) 3296 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3297 3298 3299 if (request == RTLD_DI_SERINFOSIZE) { 3300 info->dls_size = _info.dls_size; 3301 info->dls_cnt = _info.dls_cnt; 3302 return (0); 3303 } 3304 3305 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3306 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3307 return (-1); 3308 } 3309 3310 args.request = RTLD_DI_SERINFO; 3311 args.serinfo = info; 3312 args.serpath = &info->dls_serpath[0]; 3313 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3314 3315 args.flags = LA_SER_RUNPATH; 3316 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3317 return (-1); 3318 3319 args.flags = LA_SER_LIBPATH; 3320 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3321 return (-1); 3322 3323 args.flags = LA_SER_RUNPATH; 3324 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3325 return (-1); 3326 3327 args.flags = LA_SER_CONFIG; 3328 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3329 != NULL) 3330 return (-1); 3331 3332 args.flags = LA_SER_DEFAULT; 3333 if (!obj->z_nodeflib && 3334 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3335 return (-1); 3336 return (0); 3337 } 3338 3339 static int 3340 rtld_dirname(const char *path, char *bname) 3341 { 3342 const char *endp; 3343 3344 /* Empty or NULL string gets treated as "." */ 3345 if (path == NULL || *path == '\0') { 3346 bname[0] = '.'; 3347 bname[1] = '\0'; 3348 return (0); 3349 } 3350 3351 /* Strip trailing slashes */ 3352 endp = path + strlen(path) - 1; 3353 while (endp > path && *endp == '/') 3354 endp--; 3355 3356 /* Find the start of the dir */ 3357 while (endp > path && *endp != '/') 3358 endp--; 3359 3360 /* Either the dir is "/" or there are no slashes */ 3361 if (endp == path) { 3362 bname[0] = *endp == '/' ? '/' : '.'; 3363 bname[1] = '\0'; 3364 return (0); 3365 } else { 3366 do { 3367 endp--; 3368 } while (endp > path && *endp == '/'); 3369 } 3370 3371 if (endp - path + 2 > PATH_MAX) 3372 { 3373 _rtld_error("Filename is too long: %s", path); 3374 return(-1); 3375 } 3376 3377 strncpy(bname, path, endp - path + 1); 3378 bname[endp - path + 1] = '\0'; 3379 return (0); 3380 } 3381 3382 static int 3383 rtld_dirname_abs(const char *path, char *base) 3384 { 3385 char base_rel[PATH_MAX]; 3386 3387 if (rtld_dirname(path, base) == -1) 3388 return (-1); 3389 if (base[0] == '/') 3390 return (0); 3391 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3392 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3393 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3394 return (-1); 3395 strcpy(base, base_rel); 3396 return (0); 3397 } 3398 3399 static void 3400 linkmap_add(Obj_Entry *obj) 3401 { 3402 struct link_map *l = &obj->linkmap; 3403 struct link_map *prev; 3404 3405 obj->linkmap.l_name = obj->path; 3406 obj->linkmap.l_addr = obj->mapbase; 3407 obj->linkmap.l_ld = obj->dynamic; 3408 #ifdef __mips__ 3409 /* GDB needs load offset on MIPS to use the symbols */ 3410 obj->linkmap.l_offs = obj->relocbase; 3411 #endif 3412 3413 if (r_debug.r_map == NULL) { 3414 r_debug.r_map = l; 3415 return; 3416 } 3417 3418 /* 3419 * Scan to the end of the list, but not past the entry for the 3420 * dynamic linker, which we want to keep at the very end. 3421 */ 3422 for (prev = r_debug.r_map; 3423 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3424 prev = prev->l_next) 3425 ; 3426 3427 /* Link in the new entry. */ 3428 l->l_prev = prev; 3429 l->l_next = prev->l_next; 3430 if (l->l_next != NULL) 3431 l->l_next->l_prev = l; 3432 prev->l_next = l; 3433 } 3434 3435 static void 3436 linkmap_delete(Obj_Entry *obj) 3437 { 3438 struct link_map *l = &obj->linkmap; 3439 3440 if (l->l_prev == NULL) { 3441 if ((r_debug.r_map = l->l_next) != NULL) 3442 l->l_next->l_prev = NULL; 3443 return; 3444 } 3445 3446 if ((l->l_prev->l_next = l->l_next) != NULL) 3447 l->l_next->l_prev = l->l_prev; 3448 } 3449 3450 /* 3451 * Function for the debugger to set a breakpoint on to gain control. 3452 * 3453 * The two parameters allow the debugger to easily find and determine 3454 * what the runtime loader is doing and to whom it is doing it. 3455 * 3456 * When the loadhook trap is hit (r_debug_state, set at program 3457 * initialization), the arguments can be found on the stack: 3458 * 3459 * +8 struct link_map *m 3460 * +4 struct r_debug *rd 3461 * +0 RetAddr 3462 */ 3463 void 3464 r_debug_state(struct r_debug* rd, struct link_map *m) 3465 { 3466 /* 3467 * The following is a hack to force the compiler to emit calls to 3468 * this function, even when optimizing. If the function is empty, 3469 * the compiler is not obliged to emit any code for calls to it, 3470 * even when marked __noinline. However, gdb depends on those 3471 * calls being made. 3472 */ 3473 __asm __volatile("" : : : "memory"); 3474 } 3475 3476 /* 3477 * Get address of the pointer variable in the main program. 3478 * Prefer non-weak symbol over the weak one. 3479 */ 3480 static const void ** 3481 get_program_var_addr(const char *name, RtldLockState *lockstate) 3482 { 3483 SymLook req; 3484 DoneList donelist; 3485 3486 symlook_init(&req, name); 3487 req.lockstate = lockstate; 3488 donelist_init(&donelist); 3489 if (symlook_global(&req, &donelist) != 0) 3490 return (NULL); 3491 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3492 return ((const void **)make_function_pointer(req.sym_out, 3493 req.defobj_out)); 3494 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3495 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3496 else 3497 return ((const void **)(req.defobj_out->relocbase + 3498 req.sym_out->st_value)); 3499 } 3500 3501 /* 3502 * Set a pointer variable in the main program to the given value. This 3503 * is used to set key variables such as "environ" before any of the 3504 * init functions are called. 3505 */ 3506 static void 3507 set_program_var(const char *name, const void *value) 3508 { 3509 const void **addr; 3510 3511 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3512 dbg("\"%s\": *%p <-- %p", name, addr, value); 3513 *addr = value; 3514 } 3515 } 3516 3517 /* 3518 * Search the global objects, including dependencies and main object, 3519 * for the given symbol. 3520 */ 3521 static int 3522 symlook_global(SymLook *req, DoneList *donelist) 3523 { 3524 SymLook req1; 3525 const Objlist_Entry *elm; 3526 int res; 3527 3528 symlook_init_from_req(&req1, req); 3529 3530 /* Search all objects loaded at program start up. */ 3531 if (req->defobj_out == NULL || 3532 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3533 res = symlook_list(&req1, &list_main, donelist); 3534 if (res == 0 && (req->defobj_out == NULL || 3535 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3536 req->sym_out = req1.sym_out; 3537 req->defobj_out = req1.defobj_out; 3538 assert(req->defobj_out != NULL); 3539 } 3540 } 3541 3542 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3543 STAILQ_FOREACH(elm, &list_global, link) { 3544 if (req->defobj_out != NULL && 3545 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3546 break; 3547 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3548 if (res == 0 && (req->defobj_out == NULL || 3549 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3550 req->sym_out = req1.sym_out; 3551 req->defobj_out = req1.defobj_out; 3552 assert(req->defobj_out != NULL); 3553 } 3554 } 3555 3556 return (req->sym_out != NULL ? 0 : ESRCH); 3557 } 3558 3559 /* 3560 * Given a symbol name in a referencing object, find the corresponding 3561 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3562 * no definition was found. Returns a pointer to the Obj_Entry of the 3563 * defining object via the reference parameter DEFOBJ_OUT. 3564 */ 3565 static int 3566 symlook_default(SymLook *req, const Obj_Entry *refobj) 3567 { 3568 DoneList donelist; 3569 const Objlist_Entry *elm; 3570 SymLook req1; 3571 int res; 3572 3573 donelist_init(&donelist); 3574 symlook_init_from_req(&req1, req); 3575 3576 /* Look first in the referencing object if linked symbolically. */ 3577 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3578 res = symlook_obj(&req1, refobj); 3579 if (res == 0) { 3580 req->sym_out = req1.sym_out; 3581 req->defobj_out = req1.defobj_out; 3582 assert(req->defobj_out != NULL); 3583 } 3584 } 3585 3586 symlook_global(req, &donelist); 3587 3588 /* Search all dlopened DAGs containing the referencing object. */ 3589 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3590 if (req->sym_out != NULL && 3591 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3592 break; 3593 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3594 if (res == 0 && (req->sym_out == NULL || 3595 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3596 req->sym_out = req1.sym_out; 3597 req->defobj_out = req1.defobj_out; 3598 assert(req->defobj_out != NULL); 3599 } 3600 } 3601 3602 /* 3603 * Search the dynamic linker itself, and possibly resolve the 3604 * symbol from there. This is how the application links to 3605 * dynamic linker services such as dlopen. 3606 */ 3607 if (req->sym_out == NULL || 3608 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3609 res = symlook_obj(&req1, &obj_rtld); 3610 if (res == 0) { 3611 req->sym_out = req1.sym_out; 3612 req->defobj_out = req1.defobj_out; 3613 assert(req->defobj_out != NULL); 3614 } 3615 } 3616 3617 return (req->sym_out != NULL ? 0 : ESRCH); 3618 } 3619 3620 static int 3621 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3622 { 3623 const Elf_Sym *def; 3624 const Obj_Entry *defobj; 3625 const Objlist_Entry *elm; 3626 SymLook req1; 3627 int res; 3628 3629 def = NULL; 3630 defobj = NULL; 3631 STAILQ_FOREACH(elm, objlist, link) { 3632 if (donelist_check(dlp, elm->obj)) 3633 continue; 3634 symlook_init_from_req(&req1, req); 3635 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3636 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3637 def = req1.sym_out; 3638 defobj = req1.defobj_out; 3639 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3640 break; 3641 } 3642 } 3643 } 3644 if (def != NULL) { 3645 req->sym_out = def; 3646 req->defobj_out = defobj; 3647 return (0); 3648 } 3649 return (ESRCH); 3650 } 3651 3652 /* 3653 * Search the chain of DAGS cointed to by the given Needed_Entry 3654 * for a symbol of the given name. Each DAG is scanned completely 3655 * before advancing to the next one. Returns a pointer to the symbol, 3656 * or NULL if no definition was found. 3657 */ 3658 static int 3659 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3660 { 3661 const Elf_Sym *def; 3662 const Needed_Entry *n; 3663 const Obj_Entry *defobj; 3664 SymLook req1; 3665 int res; 3666 3667 def = NULL; 3668 defobj = NULL; 3669 symlook_init_from_req(&req1, req); 3670 for (n = needed; n != NULL; n = n->next) { 3671 if (n->obj == NULL || 3672 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3673 continue; 3674 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3675 def = req1.sym_out; 3676 defobj = req1.defobj_out; 3677 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3678 break; 3679 } 3680 } 3681 if (def != NULL) { 3682 req->sym_out = def; 3683 req->defobj_out = defobj; 3684 return (0); 3685 } 3686 return (ESRCH); 3687 } 3688 3689 /* 3690 * Search the symbol table of a single shared object for a symbol of 3691 * the given name and version, if requested. Returns a pointer to the 3692 * symbol, or NULL if no definition was found. If the object is 3693 * filter, return filtered symbol from filtee. 3694 * 3695 * The symbol's hash value is passed in for efficiency reasons; that 3696 * eliminates many recomputations of the hash value. 3697 */ 3698 int 3699 symlook_obj(SymLook *req, const Obj_Entry *obj) 3700 { 3701 DoneList donelist; 3702 SymLook req1; 3703 int flags, res, mres; 3704 3705 /* 3706 * If there is at least one valid hash at this point, we prefer to 3707 * use the faster GNU version if available. 3708 */ 3709 if (obj->valid_hash_gnu) 3710 mres = symlook_obj1_gnu(req, obj); 3711 else if (obj->valid_hash_sysv) 3712 mres = symlook_obj1_sysv(req, obj); 3713 else 3714 return (EINVAL); 3715 3716 if (mres == 0) { 3717 if (obj->needed_filtees != NULL) { 3718 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3719 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3720 donelist_init(&donelist); 3721 symlook_init_from_req(&req1, req); 3722 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3723 if (res == 0) { 3724 req->sym_out = req1.sym_out; 3725 req->defobj_out = req1.defobj_out; 3726 } 3727 return (res); 3728 } 3729 if (obj->needed_aux_filtees != NULL) { 3730 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3731 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3732 donelist_init(&donelist); 3733 symlook_init_from_req(&req1, req); 3734 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3735 if (res == 0) { 3736 req->sym_out = req1.sym_out; 3737 req->defobj_out = req1.defobj_out; 3738 return (res); 3739 } 3740 } 3741 } 3742 return (mres); 3743 } 3744 3745 /* Symbol match routine common to both hash functions */ 3746 static bool 3747 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3748 const unsigned long symnum) 3749 { 3750 Elf_Versym verndx; 3751 const Elf_Sym *symp; 3752 const char *strp; 3753 3754 symp = obj->symtab + symnum; 3755 strp = obj->strtab + symp->st_name; 3756 3757 switch (ELF_ST_TYPE(symp->st_info)) { 3758 case STT_FUNC: 3759 case STT_NOTYPE: 3760 case STT_OBJECT: 3761 case STT_COMMON: 3762 case STT_GNU_IFUNC: 3763 if (symp->st_value == 0) 3764 return (false); 3765 /* fallthrough */ 3766 case STT_TLS: 3767 if (symp->st_shndx != SHN_UNDEF) 3768 break; 3769 #ifndef __mips__ 3770 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3771 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3772 break; 3773 /* fallthrough */ 3774 #endif 3775 default: 3776 return (false); 3777 } 3778 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3779 return (false); 3780 3781 if (req->ventry == NULL) { 3782 if (obj->versyms != NULL) { 3783 verndx = VER_NDX(obj->versyms[symnum]); 3784 if (verndx > obj->vernum) { 3785 _rtld_error( 3786 "%s: symbol %s references wrong version %d", 3787 obj->path, obj->strtab + symnum, verndx); 3788 return (false); 3789 } 3790 /* 3791 * If we are not called from dlsym (i.e. this 3792 * is a normal relocation from unversioned 3793 * binary), accept the symbol immediately if 3794 * it happens to have first version after this 3795 * shared object became versioned. Otherwise, 3796 * if symbol is versioned and not hidden, 3797 * remember it. If it is the only symbol with 3798 * this name exported by the shared object, it 3799 * will be returned as a match by the calling 3800 * function. If symbol is global (verndx < 2) 3801 * accept it unconditionally. 3802 */ 3803 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3804 verndx == VER_NDX_GIVEN) { 3805 result->sym_out = symp; 3806 return (true); 3807 } 3808 else if (verndx >= VER_NDX_GIVEN) { 3809 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3810 == 0) { 3811 if (result->vsymp == NULL) 3812 result->vsymp = symp; 3813 result->vcount++; 3814 } 3815 return (false); 3816 } 3817 } 3818 result->sym_out = symp; 3819 return (true); 3820 } 3821 if (obj->versyms == NULL) { 3822 if (object_match_name(obj, req->ventry->name)) { 3823 _rtld_error("%s: object %s should provide version %s " 3824 "for symbol %s", obj_rtld.path, obj->path, 3825 req->ventry->name, obj->strtab + symnum); 3826 return (false); 3827 } 3828 } else { 3829 verndx = VER_NDX(obj->versyms[symnum]); 3830 if (verndx > obj->vernum) { 3831 _rtld_error("%s: symbol %s references wrong version %d", 3832 obj->path, obj->strtab + symnum, verndx); 3833 return (false); 3834 } 3835 if (obj->vertab[verndx].hash != req->ventry->hash || 3836 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3837 /* 3838 * Version does not match. Look if this is a 3839 * global symbol and if it is not hidden. If 3840 * global symbol (verndx < 2) is available, 3841 * use it. Do not return symbol if we are 3842 * called by dlvsym, because dlvsym looks for 3843 * a specific version and default one is not 3844 * what dlvsym wants. 3845 */ 3846 if ((req->flags & SYMLOOK_DLSYM) || 3847 (verndx >= VER_NDX_GIVEN) || 3848 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3849 return (false); 3850 } 3851 } 3852 result->sym_out = symp; 3853 return (true); 3854 } 3855 3856 /* 3857 * Search for symbol using SysV hash function. 3858 * obj->buckets is known not to be NULL at this point; the test for this was 3859 * performed with the obj->valid_hash_sysv assignment. 3860 */ 3861 static int 3862 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3863 { 3864 unsigned long symnum; 3865 Sym_Match_Result matchres; 3866 3867 matchres.sym_out = NULL; 3868 matchres.vsymp = NULL; 3869 matchres.vcount = 0; 3870 3871 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3872 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3873 if (symnum >= obj->nchains) 3874 return (ESRCH); /* Bad object */ 3875 3876 if (matched_symbol(req, obj, &matchres, symnum)) { 3877 req->sym_out = matchres.sym_out; 3878 req->defobj_out = obj; 3879 return (0); 3880 } 3881 } 3882 if (matchres.vcount == 1) { 3883 req->sym_out = matchres.vsymp; 3884 req->defobj_out = obj; 3885 return (0); 3886 } 3887 return (ESRCH); 3888 } 3889 3890 /* Search for symbol using GNU hash function */ 3891 static int 3892 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3893 { 3894 Elf_Addr bloom_word; 3895 const Elf32_Word *hashval; 3896 Elf32_Word bucket; 3897 Sym_Match_Result matchres; 3898 unsigned int h1, h2; 3899 unsigned long symnum; 3900 3901 matchres.sym_out = NULL; 3902 matchres.vsymp = NULL; 3903 matchres.vcount = 0; 3904 3905 /* Pick right bitmask word from Bloom filter array */ 3906 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3907 obj->maskwords_bm_gnu]; 3908 3909 /* Calculate modulus word size of gnu hash and its derivative */ 3910 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3911 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3912 3913 /* Filter out the "definitely not in set" queries */ 3914 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3915 return (ESRCH); 3916 3917 /* Locate hash chain and corresponding value element*/ 3918 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3919 if (bucket == 0) 3920 return (ESRCH); 3921 hashval = &obj->chain_zero_gnu[bucket]; 3922 do { 3923 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3924 symnum = hashval - obj->chain_zero_gnu; 3925 if (matched_symbol(req, obj, &matchres, symnum)) { 3926 req->sym_out = matchres.sym_out; 3927 req->defobj_out = obj; 3928 return (0); 3929 } 3930 } 3931 } while ((*hashval++ & 1) == 0); 3932 if (matchres.vcount == 1) { 3933 req->sym_out = matchres.vsymp; 3934 req->defobj_out = obj; 3935 return (0); 3936 } 3937 return (ESRCH); 3938 } 3939 3940 static void 3941 trace_loaded_objects(Obj_Entry *obj) 3942 { 3943 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3944 int c; 3945 3946 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3947 main_local = ""; 3948 3949 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3950 fmt1 = "\t%o => %p (%x)\n"; 3951 3952 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3953 fmt2 = "\t%o (%x)\n"; 3954 3955 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3956 3957 for (; obj; obj = obj->next) { 3958 Needed_Entry *needed; 3959 char *name, *path; 3960 bool is_lib; 3961 3962 if (list_containers && obj->needed != NULL) 3963 rtld_printf("%s:\n", obj->path); 3964 for (needed = obj->needed; needed; needed = needed->next) { 3965 if (needed->obj != NULL) { 3966 if (needed->obj->traced && !list_containers) 3967 continue; 3968 needed->obj->traced = true; 3969 path = needed->obj->path; 3970 } else 3971 path = "not found"; 3972 3973 name = (char *)obj->strtab + needed->name; 3974 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 3975 3976 fmt = is_lib ? fmt1 : fmt2; 3977 while ((c = *fmt++) != '\0') { 3978 switch (c) { 3979 default: 3980 rtld_putchar(c); 3981 continue; 3982 case '\\': 3983 switch (c = *fmt) { 3984 case '\0': 3985 continue; 3986 case 'n': 3987 rtld_putchar('\n'); 3988 break; 3989 case 't': 3990 rtld_putchar('\t'); 3991 break; 3992 } 3993 break; 3994 case '%': 3995 switch (c = *fmt) { 3996 case '\0': 3997 continue; 3998 case '%': 3999 default: 4000 rtld_putchar(c); 4001 break; 4002 case 'A': 4003 rtld_putstr(main_local); 4004 break; 4005 case 'a': 4006 rtld_putstr(obj_main->path); 4007 break; 4008 case 'o': 4009 rtld_putstr(name); 4010 break; 4011 #if 0 4012 case 'm': 4013 rtld_printf("%d", sodp->sod_major); 4014 break; 4015 case 'n': 4016 rtld_printf("%d", sodp->sod_minor); 4017 break; 4018 #endif 4019 case 'p': 4020 rtld_putstr(path); 4021 break; 4022 case 'x': 4023 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4024 0); 4025 break; 4026 } 4027 break; 4028 } 4029 ++fmt; 4030 } 4031 } 4032 } 4033 } 4034 4035 /* 4036 * Unload a dlopened object and its dependencies from memory and from 4037 * our data structures. It is assumed that the DAG rooted in the 4038 * object has already been unreferenced, and that the object has a 4039 * reference count of 0. 4040 */ 4041 static void 4042 unload_object(Obj_Entry *root) 4043 { 4044 Obj_Entry *obj; 4045 Obj_Entry **linkp; 4046 4047 assert(root->refcount == 0); 4048 4049 /* 4050 * Pass over the DAG removing unreferenced objects from 4051 * appropriate lists. 4052 */ 4053 unlink_object(root); 4054 4055 /* Unmap all objects that are no longer referenced. */ 4056 linkp = &obj_list->next; 4057 while ((obj = *linkp) != NULL) { 4058 if (obj->refcount == 0) { 4059 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4060 obj->path); 4061 dbg("unloading \"%s\"", obj->path); 4062 unload_filtees(root); 4063 munmap(obj->mapbase, obj->mapsize); 4064 linkmap_delete(obj); 4065 *linkp = obj->next; 4066 obj_count--; 4067 obj_free(obj); 4068 } else 4069 linkp = &obj->next; 4070 } 4071 obj_tail = linkp; 4072 } 4073 4074 static void 4075 unlink_object(Obj_Entry *root) 4076 { 4077 Objlist_Entry *elm; 4078 4079 if (root->refcount == 0) { 4080 /* Remove the object from the RTLD_GLOBAL list. */ 4081 objlist_remove(&list_global, root); 4082 4083 /* Remove the object from all objects' DAG lists. */ 4084 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4085 objlist_remove(&elm->obj->dldags, root); 4086 if (elm->obj != root) 4087 unlink_object(elm->obj); 4088 } 4089 } 4090 } 4091 4092 static void 4093 ref_dag(Obj_Entry *root) 4094 { 4095 Objlist_Entry *elm; 4096 4097 assert(root->dag_inited); 4098 STAILQ_FOREACH(elm, &root->dagmembers, link) 4099 elm->obj->refcount++; 4100 } 4101 4102 static void 4103 unref_dag(Obj_Entry *root) 4104 { 4105 Objlist_Entry *elm; 4106 4107 assert(root->dag_inited); 4108 STAILQ_FOREACH(elm, &root->dagmembers, link) 4109 elm->obj->refcount--; 4110 } 4111 4112 /* 4113 * Common code for MD __tls_get_addr(). 4114 */ 4115 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4116 static void * 4117 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4118 { 4119 Elf_Addr *newdtv, *dtv; 4120 RtldLockState lockstate; 4121 int to_copy; 4122 4123 dtv = *dtvp; 4124 /* Check dtv generation in case new modules have arrived */ 4125 if (dtv[0] != tls_dtv_generation) { 4126 wlock_acquire(rtld_bind_lock, &lockstate); 4127 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4128 to_copy = dtv[1]; 4129 if (to_copy > tls_max_index) 4130 to_copy = tls_max_index; 4131 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4132 newdtv[0] = tls_dtv_generation; 4133 newdtv[1] = tls_max_index; 4134 free(dtv); 4135 lock_release(rtld_bind_lock, &lockstate); 4136 dtv = *dtvp = newdtv; 4137 } 4138 4139 /* Dynamically allocate module TLS if necessary */ 4140 if (dtv[index + 1] == 0) { 4141 /* Signal safe, wlock will block out signals. */ 4142 wlock_acquire(rtld_bind_lock, &lockstate); 4143 if (!dtv[index + 1]) 4144 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4145 lock_release(rtld_bind_lock, &lockstate); 4146 } 4147 return ((void *)(dtv[index + 1] + offset)); 4148 } 4149 4150 void * 4151 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4152 { 4153 Elf_Addr *dtv; 4154 4155 dtv = *dtvp; 4156 /* Check dtv generation in case new modules have arrived */ 4157 if (__predict_true(dtv[0] == tls_dtv_generation && 4158 dtv[index + 1] != 0)) 4159 return ((void *)(dtv[index + 1] + offset)); 4160 return (tls_get_addr_slow(dtvp, index, offset)); 4161 } 4162 4163 #if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4164 4165 /* 4166 * Allocate Static TLS using the Variant I method. 4167 */ 4168 void * 4169 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4170 { 4171 Obj_Entry *obj; 4172 char *tcb; 4173 Elf_Addr **tls; 4174 Elf_Addr *dtv; 4175 Elf_Addr addr; 4176 int i; 4177 4178 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4179 return (oldtcb); 4180 4181 assert(tcbsize >= TLS_TCB_SIZE); 4182 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4183 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4184 4185 if (oldtcb != NULL) { 4186 memcpy(tls, oldtcb, tls_static_space); 4187 free(oldtcb); 4188 4189 /* Adjust the DTV. */ 4190 dtv = tls[0]; 4191 for (i = 0; i < dtv[1]; i++) { 4192 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4193 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4194 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4195 } 4196 } 4197 } else { 4198 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4199 tls[0] = dtv; 4200 dtv[0] = tls_dtv_generation; 4201 dtv[1] = tls_max_index; 4202 4203 for (obj = objs; obj; obj = obj->next) { 4204 if (obj->tlsoffset > 0) { 4205 addr = (Elf_Addr)tls + obj->tlsoffset; 4206 if (obj->tlsinitsize > 0) 4207 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4208 if (obj->tlssize > obj->tlsinitsize) 4209 memset((void*) (addr + obj->tlsinitsize), 0, 4210 obj->tlssize - obj->tlsinitsize); 4211 dtv[obj->tlsindex + 1] = addr; 4212 } 4213 } 4214 } 4215 4216 return (tcb); 4217 } 4218 4219 void 4220 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4221 { 4222 Elf_Addr *dtv; 4223 Elf_Addr tlsstart, tlsend; 4224 int dtvsize, i; 4225 4226 assert(tcbsize >= TLS_TCB_SIZE); 4227 4228 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4229 tlsend = tlsstart + tls_static_space; 4230 4231 dtv = *(Elf_Addr **)tlsstart; 4232 dtvsize = dtv[1]; 4233 for (i = 0; i < dtvsize; i++) { 4234 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4235 free((void*)dtv[i+2]); 4236 } 4237 } 4238 free(dtv); 4239 free(tcb); 4240 } 4241 4242 #endif 4243 4244 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4245 4246 /* 4247 * Allocate Static TLS using the Variant II method. 4248 */ 4249 void * 4250 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4251 { 4252 Obj_Entry *obj; 4253 size_t size; 4254 char *tls; 4255 Elf_Addr *dtv, *olddtv; 4256 Elf_Addr segbase, oldsegbase, addr; 4257 int i; 4258 4259 size = round(tls_static_space, tcbalign); 4260 4261 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4262 tls = xcalloc(1, size + tcbsize); 4263 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4264 4265 segbase = (Elf_Addr)(tls + size); 4266 ((Elf_Addr*)segbase)[0] = segbase; 4267 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4268 4269 dtv[0] = tls_dtv_generation; 4270 dtv[1] = tls_max_index; 4271 4272 if (oldtls) { 4273 /* 4274 * Copy the static TLS block over whole. 4275 */ 4276 oldsegbase = (Elf_Addr) oldtls; 4277 memcpy((void *)(segbase - tls_static_space), 4278 (const void *)(oldsegbase - tls_static_space), 4279 tls_static_space); 4280 4281 /* 4282 * If any dynamic TLS blocks have been created tls_get_addr(), 4283 * move them over. 4284 */ 4285 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4286 for (i = 0; i < olddtv[1]; i++) { 4287 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4288 dtv[i+2] = olddtv[i+2]; 4289 olddtv[i+2] = 0; 4290 } 4291 } 4292 4293 /* 4294 * We assume that this block was the one we created with 4295 * allocate_initial_tls(). 4296 */ 4297 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4298 } else { 4299 for (obj = objs; obj; obj = obj->next) { 4300 if (obj->tlsoffset) { 4301 addr = segbase - obj->tlsoffset; 4302 memset((void*) (addr + obj->tlsinitsize), 4303 0, obj->tlssize - obj->tlsinitsize); 4304 if (obj->tlsinit) 4305 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4306 dtv[obj->tlsindex + 1] = addr; 4307 } 4308 } 4309 } 4310 4311 return (void*) segbase; 4312 } 4313 4314 void 4315 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4316 { 4317 size_t size; 4318 Elf_Addr* dtv; 4319 int dtvsize, i; 4320 Elf_Addr tlsstart, tlsend; 4321 4322 /* 4323 * Figure out the size of the initial TLS block so that we can 4324 * find stuff which ___tls_get_addr() allocated dynamically. 4325 */ 4326 size = round(tls_static_space, tcbalign); 4327 4328 dtv = ((Elf_Addr**)tls)[1]; 4329 dtvsize = dtv[1]; 4330 tlsend = (Elf_Addr) tls; 4331 tlsstart = tlsend - size; 4332 for (i = 0; i < dtvsize; i++) { 4333 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 4334 free((void*) dtv[i+2]); 4335 } 4336 } 4337 4338 free((void*) tlsstart); 4339 free((void*) dtv); 4340 } 4341 4342 #endif 4343 4344 /* 4345 * Allocate TLS block for module with given index. 4346 */ 4347 void * 4348 allocate_module_tls(int index) 4349 { 4350 Obj_Entry* obj; 4351 char* p; 4352 4353 for (obj = obj_list; obj; obj = obj->next) { 4354 if (obj->tlsindex == index) 4355 break; 4356 } 4357 if (!obj) { 4358 _rtld_error("Can't find module with TLS index %d", index); 4359 die(); 4360 } 4361 4362 p = malloc(obj->tlssize); 4363 if (p == NULL) { 4364 _rtld_error("Cannot allocate TLS block for index %d", index); 4365 die(); 4366 } 4367 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4368 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4369 4370 return p; 4371 } 4372 4373 bool 4374 allocate_tls_offset(Obj_Entry *obj) 4375 { 4376 size_t off; 4377 4378 if (obj->tls_done) 4379 return true; 4380 4381 if (obj->tlssize == 0) { 4382 obj->tls_done = true; 4383 return true; 4384 } 4385 4386 if (obj->tlsindex == 1) 4387 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4388 else 4389 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4390 obj->tlssize, obj->tlsalign); 4391 4392 /* 4393 * If we have already fixed the size of the static TLS block, we 4394 * must stay within that size. When allocating the static TLS, we 4395 * leave a small amount of space spare to be used for dynamically 4396 * loading modules which use static TLS. 4397 */ 4398 if (tls_static_space) { 4399 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4400 return false; 4401 } 4402 4403 tls_last_offset = obj->tlsoffset = off; 4404 tls_last_size = obj->tlssize; 4405 obj->tls_done = true; 4406 4407 return true; 4408 } 4409 4410 void 4411 free_tls_offset(Obj_Entry *obj) 4412 { 4413 4414 /* 4415 * If we were the last thing to allocate out of the static TLS 4416 * block, we give our space back to the 'allocator'. This is a 4417 * simplistic workaround to allow libGL.so.1 to be loaded and 4418 * unloaded multiple times. 4419 */ 4420 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4421 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4422 tls_last_offset -= obj->tlssize; 4423 tls_last_size = 0; 4424 } 4425 } 4426 4427 void * 4428 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4429 { 4430 void *ret; 4431 RtldLockState lockstate; 4432 4433 wlock_acquire(rtld_bind_lock, &lockstate); 4434 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4435 lock_release(rtld_bind_lock, &lockstate); 4436 return (ret); 4437 } 4438 4439 void 4440 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4441 { 4442 RtldLockState lockstate; 4443 4444 wlock_acquire(rtld_bind_lock, &lockstate); 4445 free_tls(tcb, tcbsize, tcbalign); 4446 lock_release(rtld_bind_lock, &lockstate); 4447 } 4448 4449 static void 4450 object_add_name(Obj_Entry *obj, const char *name) 4451 { 4452 Name_Entry *entry; 4453 size_t len; 4454 4455 len = strlen(name); 4456 entry = malloc(sizeof(Name_Entry) + len); 4457 4458 if (entry != NULL) { 4459 strcpy(entry->name, name); 4460 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4461 } 4462 } 4463 4464 static int 4465 object_match_name(const Obj_Entry *obj, const char *name) 4466 { 4467 Name_Entry *entry; 4468 4469 STAILQ_FOREACH(entry, &obj->names, link) { 4470 if (strcmp(name, entry->name) == 0) 4471 return (1); 4472 } 4473 return (0); 4474 } 4475 4476 static Obj_Entry * 4477 locate_dependency(const Obj_Entry *obj, const char *name) 4478 { 4479 const Objlist_Entry *entry; 4480 const Needed_Entry *needed; 4481 4482 STAILQ_FOREACH(entry, &list_main, link) { 4483 if (object_match_name(entry->obj, name)) 4484 return entry->obj; 4485 } 4486 4487 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4488 if (strcmp(obj->strtab + needed->name, name) == 0 || 4489 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4490 /* 4491 * If there is DT_NEEDED for the name we are looking for, 4492 * we are all set. Note that object might not be found if 4493 * dependency was not loaded yet, so the function can 4494 * return NULL here. This is expected and handled 4495 * properly by the caller. 4496 */ 4497 return (needed->obj); 4498 } 4499 } 4500 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4501 obj->path, name); 4502 die(); 4503 } 4504 4505 static int 4506 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4507 const Elf_Vernaux *vna) 4508 { 4509 const Elf_Verdef *vd; 4510 const char *vername; 4511 4512 vername = refobj->strtab + vna->vna_name; 4513 vd = depobj->verdef; 4514 if (vd == NULL) { 4515 _rtld_error("%s: version %s required by %s not defined", 4516 depobj->path, vername, refobj->path); 4517 return (-1); 4518 } 4519 for (;;) { 4520 if (vd->vd_version != VER_DEF_CURRENT) { 4521 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4522 depobj->path, vd->vd_version); 4523 return (-1); 4524 } 4525 if (vna->vna_hash == vd->vd_hash) { 4526 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4527 ((char *)vd + vd->vd_aux); 4528 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4529 return (0); 4530 } 4531 if (vd->vd_next == 0) 4532 break; 4533 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4534 } 4535 if (vna->vna_flags & VER_FLG_WEAK) 4536 return (0); 4537 _rtld_error("%s: version %s required by %s not found", 4538 depobj->path, vername, refobj->path); 4539 return (-1); 4540 } 4541 4542 static int 4543 rtld_verify_object_versions(Obj_Entry *obj) 4544 { 4545 const Elf_Verneed *vn; 4546 const Elf_Verdef *vd; 4547 const Elf_Verdaux *vda; 4548 const Elf_Vernaux *vna; 4549 const Obj_Entry *depobj; 4550 int maxvernum, vernum; 4551 4552 if (obj->ver_checked) 4553 return (0); 4554 obj->ver_checked = true; 4555 4556 maxvernum = 0; 4557 /* 4558 * Walk over defined and required version records and figure out 4559 * max index used by any of them. Do very basic sanity checking 4560 * while there. 4561 */ 4562 vn = obj->verneed; 4563 while (vn != NULL) { 4564 if (vn->vn_version != VER_NEED_CURRENT) { 4565 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4566 obj->path, vn->vn_version); 4567 return (-1); 4568 } 4569 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4570 for (;;) { 4571 vernum = VER_NEED_IDX(vna->vna_other); 4572 if (vernum > maxvernum) 4573 maxvernum = vernum; 4574 if (vna->vna_next == 0) 4575 break; 4576 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4577 } 4578 if (vn->vn_next == 0) 4579 break; 4580 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4581 } 4582 4583 vd = obj->verdef; 4584 while (vd != NULL) { 4585 if (vd->vd_version != VER_DEF_CURRENT) { 4586 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4587 obj->path, vd->vd_version); 4588 return (-1); 4589 } 4590 vernum = VER_DEF_IDX(vd->vd_ndx); 4591 if (vernum > maxvernum) 4592 maxvernum = vernum; 4593 if (vd->vd_next == 0) 4594 break; 4595 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4596 } 4597 4598 if (maxvernum == 0) 4599 return (0); 4600 4601 /* 4602 * Store version information in array indexable by version index. 4603 * Verify that object version requirements are satisfied along the 4604 * way. 4605 */ 4606 obj->vernum = maxvernum + 1; 4607 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4608 4609 vd = obj->verdef; 4610 while (vd != NULL) { 4611 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4612 vernum = VER_DEF_IDX(vd->vd_ndx); 4613 assert(vernum <= maxvernum); 4614 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4615 obj->vertab[vernum].hash = vd->vd_hash; 4616 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4617 obj->vertab[vernum].file = NULL; 4618 obj->vertab[vernum].flags = 0; 4619 } 4620 if (vd->vd_next == 0) 4621 break; 4622 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4623 } 4624 4625 vn = obj->verneed; 4626 while (vn != NULL) { 4627 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4628 if (depobj == NULL) 4629 return (-1); 4630 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4631 for (;;) { 4632 if (check_object_provided_version(obj, depobj, vna)) 4633 return (-1); 4634 vernum = VER_NEED_IDX(vna->vna_other); 4635 assert(vernum <= maxvernum); 4636 obj->vertab[vernum].hash = vna->vna_hash; 4637 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4638 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4639 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4640 VER_INFO_HIDDEN : 0; 4641 if (vna->vna_next == 0) 4642 break; 4643 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4644 } 4645 if (vn->vn_next == 0) 4646 break; 4647 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4648 } 4649 return 0; 4650 } 4651 4652 static int 4653 rtld_verify_versions(const Objlist *objlist) 4654 { 4655 Objlist_Entry *entry; 4656 int rc; 4657 4658 rc = 0; 4659 STAILQ_FOREACH(entry, objlist, link) { 4660 /* 4661 * Skip dummy objects or objects that have their version requirements 4662 * already checked. 4663 */ 4664 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4665 continue; 4666 if (rtld_verify_object_versions(entry->obj) == -1) { 4667 rc = -1; 4668 if (ld_tracing == NULL) 4669 break; 4670 } 4671 } 4672 if (rc == 0 || ld_tracing != NULL) 4673 rc = rtld_verify_object_versions(&obj_rtld); 4674 return rc; 4675 } 4676 4677 const Ver_Entry * 4678 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4679 { 4680 Elf_Versym vernum; 4681 4682 if (obj->vertab) { 4683 vernum = VER_NDX(obj->versyms[symnum]); 4684 if (vernum >= obj->vernum) { 4685 _rtld_error("%s: symbol %s has wrong verneed value %d", 4686 obj->path, obj->strtab + symnum, vernum); 4687 } else if (obj->vertab[vernum].hash != 0) { 4688 return &obj->vertab[vernum]; 4689 } 4690 } 4691 return NULL; 4692 } 4693 4694 int 4695 _rtld_get_stack_prot(void) 4696 { 4697 4698 return (stack_prot); 4699 } 4700 4701 static void 4702 map_stacks_exec(RtldLockState *lockstate) 4703 { 4704 void (*thr_map_stacks_exec)(void); 4705 4706 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4707 return; 4708 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4709 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4710 if (thr_map_stacks_exec != NULL) { 4711 stack_prot |= PROT_EXEC; 4712 thr_map_stacks_exec(); 4713 } 4714 } 4715 4716 void 4717 symlook_init(SymLook *dst, const char *name) 4718 { 4719 4720 bzero(dst, sizeof(*dst)); 4721 dst->name = name; 4722 dst->hash = elf_hash(name); 4723 dst->hash_gnu = gnu_hash(name); 4724 } 4725 4726 static void 4727 symlook_init_from_req(SymLook *dst, const SymLook *src) 4728 { 4729 4730 dst->name = src->name; 4731 dst->hash = src->hash; 4732 dst->hash_gnu = src->hash_gnu; 4733 dst->ventry = src->ventry; 4734 dst->flags = src->flags; 4735 dst->defobj_out = NULL; 4736 dst->sym_out = NULL; 4737 dst->lockstate = src->lockstate; 4738 } 4739 4740 /* 4741 * Overrides for libc_pic-provided functions. 4742 */ 4743 4744 int 4745 __getosreldate(void) 4746 { 4747 size_t len; 4748 int oid[2]; 4749 int error, osrel; 4750 4751 if (osreldate != 0) 4752 return (osreldate); 4753 4754 oid[0] = CTL_KERN; 4755 oid[1] = KERN_OSRELDATE; 4756 osrel = 0; 4757 len = sizeof(osrel); 4758 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4759 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4760 osreldate = osrel; 4761 return (osreldate); 4762 } 4763 4764 void 4765 exit(int status) 4766 { 4767 4768 _exit(status); 4769 } 4770 4771 void (*__cleanup)(void); 4772 int __isthreaded = 0; 4773 int _thread_autoinit_dummy_decl = 1; 4774 4775 /* 4776 * No unresolved symbols for rtld. 4777 */ 4778 void 4779 __pthread_cxa_finalize(struct dl_phdr_info *a) 4780 { 4781 } 4782 4783 void 4784 __stack_chk_fail(void) 4785 { 4786 4787 _rtld_error("stack overflow detected; terminated"); 4788 die(); 4789 } 4790 __weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4791 4792 void 4793 __chk_fail(void) 4794 { 4795 4796 _rtld_error("buffer overflow detected; terminated"); 4797 die(); 4798 } 4799 4800 const char * 4801 rtld_strerror(int errnum) 4802 { 4803 4804 if (errnum < 0 || errnum >= sys_nerr) 4805 return ("Unknown error"); 4806 return (sys_errlist[errnum]); 4807 } 4808