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 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1115 break; 1116 #endif 1117 1118 case DT_FLAGS_1: 1119 if (dynp->d_un.d_val & DF_1_NOOPEN) 1120 obj->z_noopen = true; 1121 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1122 obj->z_origin = true; 1123 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1124 XXX ;*/ 1125 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1126 obj->bind_now = true; 1127 if (dynp->d_un.d_val & DF_1_NODELETE) 1128 obj->z_nodelete = true; 1129 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1130 obj->z_loadfltr = true; 1131 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1132 obj->z_nodeflib = true; 1133 break; 1134 1135 default: 1136 if (!early) { 1137 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1138 (long)dynp->d_tag); 1139 } 1140 break; 1141 } 1142 } 1143 1144 obj->traced = false; 1145 1146 if (plttype == DT_RELA) { 1147 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1148 obj->pltrel = NULL; 1149 obj->pltrelasize = obj->pltrelsize; 1150 obj->pltrelsize = 0; 1151 } 1152 1153 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1154 if (obj->valid_hash_sysv) 1155 obj->dynsymcount = obj->nchains; 1156 else if (obj->valid_hash_gnu) { 1157 obj->dynsymcount = 0; 1158 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1159 if (obj->buckets_gnu[bkt] == 0) 1160 continue; 1161 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1162 do 1163 obj->dynsymcount++; 1164 while ((*hashval++ & 1u) == 0); 1165 } 1166 obj->dynsymcount += obj->symndx_gnu; 1167 } 1168 } 1169 1170 static void 1171 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1172 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1173 { 1174 1175 if (obj->z_origin && obj->origin_path == NULL) { 1176 obj->origin_path = xmalloc(PATH_MAX); 1177 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1178 die(); 1179 } 1180 1181 if (dyn_runpath != NULL) { 1182 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1183 if (obj->z_origin) 1184 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1185 } 1186 else if (dyn_rpath != NULL) { 1187 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1188 if (obj->z_origin) 1189 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1190 } 1191 1192 if (dyn_soname != NULL) 1193 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1194 } 1195 1196 static void 1197 digest_dynamic(Obj_Entry *obj, int early) 1198 { 1199 const Elf_Dyn *dyn_rpath; 1200 const Elf_Dyn *dyn_soname; 1201 const Elf_Dyn *dyn_runpath; 1202 1203 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1204 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1205 } 1206 1207 /* 1208 * Process a shared object's program header. This is used only for the 1209 * main program, when the kernel has already loaded the main program 1210 * into memory before calling the dynamic linker. It creates and 1211 * returns an Obj_Entry structure. 1212 */ 1213 static Obj_Entry * 1214 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1215 { 1216 Obj_Entry *obj; 1217 const Elf_Phdr *phlimit = phdr + phnum; 1218 const Elf_Phdr *ph; 1219 Elf_Addr note_start, note_end; 1220 int nsegs = 0; 1221 1222 obj = obj_new(); 1223 for (ph = phdr; ph < phlimit; ph++) { 1224 if (ph->p_type != PT_PHDR) 1225 continue; 1226 1227 obj->phdr = phdr; 1228 obj->phsize = ph->p_memsz; 1229 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1230 break; 1231 } 1232 1233 obj->stack_flags = PF_X | PF_R | PF_W; 1234 1235 for (ph = phdr; ph < phlimit; ph++) { 1236 switch (ph->p_type) { 1237 1238 case PT_INTERP: 1239 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1240 break; 1241 1242 case PT_LOAD: 1243 if (nsegs == 0) { /* First load segment */ 1244 obj->vaddrbase = trunc_page(ph->p_vaddr); 1245 obj->mapbase = obj->vaddrbase + obj->relocbase; 1246 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1247 obj->vaddrbase; 1248 } else { /* Last load segment */ 1249 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1250 obj->vaddrbase; 1251 } 1252 nsegs++; 1253 break; 1254 1255 case PT_DYNAMIC: 1256 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1257 break; 1258 1259 case PT_TLS: 1260 obj->tlsindex = 1; 1261 obj->tlssize = ph->p_memsz; 1262 obj->tlsalign = ph->p_align; 1263 obj->tlsinitsize = ph->p_filesz; 1264 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1265 break; 1266 1267 case PT_GNU_STACK: 1268 obj->stack_flags = ph->p_flags; 1269 break; 1270 1271 case PT_GNU_RELRO: 1272 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1273 obj->relro_size = round_page(ph->p_memsz); 1274 break; 1275 1276 case PT_NOTE: 1277 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1278 note_end = note_start + ph->p_filesz; 1279 digest_notes(obj, note_start, note_end); 1280 break; 1281 } 1282 } 1283 if (nsegs < 1) { 1284 _rtld_error("%s: too few PT_LOAD segments", path); 1285 return NULL; 1286 } 1287 1288 obj->entry = entry; 1289 return obj; 1290 } 1291 1292 void 1293 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1294 { 1295 const Elf_Note *note; 1296 const char *note_name; 1297 uintptr_t p; 1298 1299 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1300 note = (const Elf_Note *)((const char *)(note + 1) + 1301 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1302 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1303 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1304 note->n_descsz != sizeof(int32_t)) 1305 continue; 1306 if (note->n_type != ABI_NOTETYPE && 1307 note->n_type != CRT_NOINIT_NOTETYPE) 1308 continue; 1309 note_name = (const char *)(note + 1); 1310 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1311 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1312 continue; 1313 switch (note->n_type) { 1314 case ABI_NOTETYPE: 1315 /* FreeBSD osrel note */ 1316 p = (uintptr_t)(note + 1); 1317 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1318 obj->osrel = *(const int32_t *)(p); 1319 dbg("note osrel %d", obj->osrel); 1320 break; 1321 case CRT_NOINIT_NOTETYPE: 1322 /* FreeBSD 'crt does not call init' note */ 1323 obj->crt_no_init = true; 1324 dbg("note crt_no_init"); 1325 break; 1326 } 1327 } 1328 } 1329 1330 static Obj_Entry * 1331 dlcheck(void *handle) 1332 { 1333 Obj_Entry *obj; 1334 1335 for (obj = obj_list; obj != NULL; obj = obj->next) 1336 if (obj == (Obj_Entry *) handle) 1337 break; 1338 1339 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1340 _rtld_error("Invalid shared object handle %p", handle); 1341 return NULL; 1342 } 1343 return obj; 1344 } 1345 1346 /* 1347 * If the given object is already in the donelist, return true. Otherwise 1348 * add the object to the list and return false. 1349 */ 1350 static bool 1351 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1352 { 1353 unsigned int i; 1354 1355 for (i = 0; i < dlp->num_used; i++) 1356 if (dlp->objs[i] == obj) 1357 return true; 1358 /* 1359 * Our donelist allocation should always be sufficient. But if 1360 * our threads locking isn't working properly, more shared objects 1361 * could have been loaded since we allocated the list. That should 1362 * never happen, but we'll handle it properly just in case it does. 1363 */ 1364 if (dlp->num_used < dlp->num_alloc) 1365 dlp->objs[dlp->num_used++] = obj; 1366 return false; 1367 } 1368 1369 /* 1370 * Hash function for symbol table lookup. Don't even think about changing 1371 * this. It is specified by the System V ABI. 1372 */ 1373 unsigned long 1374 elf_hash(const char *name) 1375 { 1376 const unsigned char *p = (const unsigned char *) name; 1377 unsigned long h = 0; 1378 unsigned long g; 1379 1380 while (*p != '\0') { 1381 h = (h << 4) + *p++; 1382 if ((g = h & 0xf0000000) != 0) 1383 h ^= g >> 24; 1384 h &= ~g; 1385 } 1386 return h; 1387 } 1388 1389 /* 1390 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1391 * unsigned in case it's implemented with a wider type. 1392 */ 1393 static uint32_t 1394 gnu_hash(const char *s) 1395 { 1396 uint32_t h; 1397 unsigned char c; 1398 1399 h = 5381; 1400 for (c = *s; c != '\0'; c = *++s) 1401 h = h * 33 + c; 1402 return (h & 0xffffffff); 1403 } 1404 1405 /* 1406 * Find the library with the given name, and return its full pathname. 1407 * The returned string is dynamically allocated. Generates an error 1408 * message and returns NULL if the library cannot be found. 1409 * 1410 * If the second argument is non-NULL, then it refers to an already- 1411 * loaded shared object, whose library search path will be searched. 1412 * 1413 * The search order is: 1414 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1415 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1416 * LD_LIBRARY_PATH 1417 * DT_RUNPATH in the referencing file 1418 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1419 * from list) 1420 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1421 * 1422 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1423 */ 1424 static char * 1425 find_library(const char *xname, const Obj_Entry *refobj) 1426 { 1427 char *pathname; 1428 char *name; 1429 bool nodeflib, objgiven; 1430 1431 objgiven = refobj != NULL; 1432 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1433 if (xname[0] != '/' && !trust) { 1434 _rtld_error("Absolute pathname required for shared object \"%s\"", 1435 xname); 1436 return NULL; 1437 } 1438 if (objgiven && refobj->z_origin) { 1439 return (origin_subst(__DECONST(char *, xname), 1440 refobj->origin_path)); 1441 } else { 1442 return (xstrdup(xname)); 1443 } 1444 } 1445 1446 if (libmap_disable || !objgiven || 1447 (name = lm_find(refobj->path, xname)) == NULL) 1448 name = (char *)xname; 1449 1450 dbg(" Searching for \"%s\"", name); 1451 1452 /* 1453 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1454 * back to pre-conforming behaviour if user requested so with 1455 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1456 * nodeflib. 1457 */ 1458 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1459 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1460 (refobj != NULL && 1461 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1462 (pathname = search_library_path(name, gethints(false))) != NULL || 1463 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1464 return (pathname); 1465 } else { 1466 nodeflib = objgiven ? refobj->z_nodeflib : false; 1467 if ((objgiven && 1468 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1469 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1470 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1471 (pathname = search_library_path(name, ld_library_path)) != NULL || 1472 (objgiven && 1473 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1474 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1475 (objgiven && !nodeflib && 1476 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1477 return (pathname); 1478 } 1479 1480 if (objgiven && refobj->path != NULL) { 1481 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1482 name, basename(refobj->path)); 1483 } else { 1484 _rtld_error("Shared object \"%s\" not found", name); 1485 } 1486 return NULL; 1487 } 1488 1489 /* 1490 * Given a symbol number in a referencing object, find the corresponding 1491 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1492 * no definition was found. Returns a pointer to the Obj_Entry of the 1493 * defining object via the reference parameter DEFOBJ_OUT. 1494 */ 1495 const Elf_Sym * 1496 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1497 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1498 RtldLockState *lockstate) 1499 { 1500 const Elf_Sym *ref; 1501 const Elf_Sym *def; 1502 const Obj_Entry *defobj; 1503 SymLook req; 1504 const char *name; 1505 int res; 1506 1507 /* 1508 * If we have already found this symbol, get the information from 1509 * the cache. 1510 */ 1511 if (symnum >= refobj->dynsymcount) 1512 return NULL; /* Bad object */ 1513 if (cache != NULL && cache[symnum].sym != NULL) { 1514 *defobj_out = cache[symnum].obj; 1515 return cache[symnum].sym; 1516 } 1517 1518 ref = refobj->symtab + symnum; 1519 name = refobj->strtab + ref->st_name; 1520 def = NULL; 1521 defobj = NULL; 1522 1523 /* 1524 * We don't have to do a full scale lookup if the symbol is local. 1525 * We know it will bind to the instance in this load module; to 1526 * which we already have a pointer (ie ref). By not doing a lookup, 1527 * we not only improve performance, but it also avoids unresolvable 1528 * symbols when local symbols are not in the hash table. This has 1529 * been seen with the ia64 toolchain. 1530 */ 1531 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1532 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1533 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1534 symnum); 1535 } 1536 symlook_init(&req, name); 1537 req.flags = flags; 1538 req.ventry = fetch_ventry(refobj, symnum); 1539 req.lockstate = lockstate; 1540 res = symlook_default(&req, refobj); 1541 if (res == 0) { 1542 def = req.sym_out; 1543 defobj = req.defobj_out; 1544 } 1545 } else { 1546 def = ref; 1547 defobj = refobj; 1548 } 1549 1550 /* 1551 * If we found no definition and the reference is weak, treat the 1552 * symbol as having the value zero. 1553 */ 1554 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1555 def = &sym_zero; 1556 defobj = obj_main; 1557 } 1558 1559 if (def != NULL) { 1560 *defobj_out = defobj; 1561 /* Record the information in the cache to avoid subsequent lookups. */ 1562 if (cache != NULL) { 1563 cache[symnum].sym = def; 1564 cache[symnum].obj = defobj; 1565 } 1566 } else { 1567 if (refobj != &obj_rtld) 1568 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1569 } 1570 return def; 1571 } 1572 1573 /* 1574 * Return the search path from the ldconfig hints file, reading it if 1575 * necessary. If nostdlib is true, then the default search paths are 1576 * not added to result. 1577 * 1578 * Returns NULL if there are problems with the hints file, 1579 * or if the search path there is empty. 1580 */ 1581 static const char * 1582 gethints(bool nostdlib) 1583 { 1584 static char *hints, *filtered_path; 1585 struct elfhints_hdr hdr; 1586 struct fill_search_info_args sargs, hargs; 1587 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1588 struct dl_serpath *SLPpath, *hintpath; 1589 char *p; 1590 unsigned int SLPndx, hintndx, fndx, fcount; 1591 int fd; 1592 size_t flen; 1593 bool skip; 1594 1595 /* First call, read the hints file */ 1596 if (hints == NULL) { 1597 /* Keep from trying again in case the hints file is bad. */ 1598 hints = ""; 1599 1600 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1601 return (NULL); 1602 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1603 hdr.magic != ELFHINTS_MAGIC || 1604 hdr.version != 1) { 1605 close(fd); 1606 return (NULL); 1607 } 1608 p = xmalloc(hdr.dirlistlen + 1); 1609 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1610 read(fd, p, hdr.dirlistlen + 1) != 1611 (ssize_t)hdr.dirlistlen + 1) { 1612 free(p); 1613 close(fd); 1614 return (NULL); 1615 } 1616 hints = p; 1617 close(fd); 1618 } 1619 1620 /* 1621 * If caller agreed to receive list which includes the default 1622 * paths, we are done. Otherwise, if we still did not 1623 * calculated filtered result, do it now. 1624 */ 1625 if (!nostdlib) 1626 return (hints[0] != '\0' ? hints : NULL); 1627 if (filtered_path != NULL) 1628 goto filt_ret; 1629 1630 /* 1631 * Obtain the list of all configured search paths, and the 1632 * list of the default paths. 1633 * 1634 * First estimate the size of the results. 1635 */ 1636 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1637 smeta.dls_cnt = 0; 1638 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1639 hmeta.dls_cnt = 0; 1640 1641 sargs.request = RTLD_DI_SERINFOSIZE; 1642 sargs.serinfo = &smeta; 1643 hargs.request = RTLD_DI_SERINFOSIZE; 1644 hargs.serinfo = &hmeta; 1645 1646 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1647 path_enumerate(p, fill_search_info, &hargs); 1648 1649 SLPinfo = xmalloc(smeta.dls_size); 1650 hintinfo = xmalloc(hmeta.dls_size); 1651 1652 /* 1653 * Next fetch both sets of paths. 1654 */ 1655 sargs.request = RTLD_DI_SERINFO; 1656 sargs.serinfo = SLPinfo; 1657 sargs.serpath = &SLPinfo->dls_serpath[0]; 1658 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1659 1660 hargs.request = RTLD_DI_SERINFO; 1661 hargs.serinfo = hintinfo; 1662 hargs.serpath = &hintinfo->dls_serpath[0]; 1663 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1664 1665 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1666 path_enumerate(p, fill_search_info, &hargs); 1667 1668 /* 1669 * Now calculate the difference between two sets, by excluding 1670 * standard paths from the full set. 1671 */ 1672 fndx = 0; 1673 fcount = 0; 1674 filtered_path = xmalloc(hdr.dirlistlen + 1); 1675 hintpath = &hintinfo->dls_serpath[0]; 1676 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1677 skip = false; 1678 SLPpath = &SLPinfo->dls_serpath[0]; 1679 /* 1680 * Check each standard path against current. 1681 */ 1682 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1683 /* matched, skip the path */ 1684 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1685 skip = true; 1686 break; 1687 } 1688 } 1689 if (skip) 1690 continue; 1691 /* 1692 * Not matched against any standard path, add the path 1693 * to result. Separate consequtive paths with ':'. 1694 */ 1695 if (fcount > 0) { 1696 filtered_path[fndx] = ':'; 1697 fndx++; 1698 } 1699 fcount++; 1700 flen = strlen(hintpath->dls_name); 1701 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1702 fndx += flen; 1703 } 1704 filtered_path[fndx] = '\0'; 1705 1706 free(SLPinfo); 1707 free(hintinfo); 1708 1709 filt_ret: 1710 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1711 } 1712 1713 static void 1714 init_dag(Obj_Entry *root) 1715 { 1716 const Needed_Entry *needed; 1717 const Objlist_Entry *elm; 1718 DoneList donelist; 1719 1720 if (root->dag_inited) 1721 return; 1722 donelist_init(&donelist); 1723 1724 /* Root object belongs to own DAG. */ 1725 objlist_push_tail(&root->dldags, root); 1726 objlist_push_tail(&root->dagmembers, root); 1727 donelist_check(&donelist, root); 1728 1729 /* 1730 * Add dependencies of root object to DAG in breadth order 1731 * by exploiting the fact that each new object get added 1732 * to the tail of the dagmembers list. 1733 */ 1734 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1735 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1736 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1737 continue; 1738 objlist_push_tail(&needed->obj->dldags, root); 1739 objlist_push_tail(&root->dagmembers, needed->obj); 1740 } 1741 } 1742 root->dag_inited = true; 1743 } 1744 1745 static void 1746 process_nodelete(Obj_Entry *root) 1747 { 1748 const Objlist_Entry *elm; 1749 1750 /* 1751 * Walk over object DAG and process every dependent object that 1752 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1753 * which then should have its reference upped separately. 1754 */ 1755 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1756 if (elm->obj != NULL && elm->obj->z_nodelete && 1757 !elm->obj->ref_nodel) { 1758 dbg("obj %s nodelete", elm->obj->path); 1759 init_dag(elm->obj); 1760 ref_dag(elm->obj); 1761 elm->obj->ref_nodel = true; 1762 } 1763 } 1764 } 1765 /* 1766 * Initialize the dynamic linker. The argument is the address at which 1767 * the dynamic linker has been mapped into memory. The primary task of 1768 * this function is to relocate the dynamic linker. 1769 */ 1770 static void 1771 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1772 { 1773 Obj_Entry objtmp; /* Temporary rtld object */ 1774 const Elf_Dyn *dyn_rpath; 1775 const Elf_Dyn *dyn_soname; 1776 const Elf_Dyn *dyn_runpath; 1777 1778 /* 1779 * Conjure up an Obj_Entry structure for the dynamic linker. 1780 * 1781 * The "path" member can't be initialized yet because string constants 1782 * cannot yet be accessed. Below we will set it correctly. 1783 */ 1784 memset(&objtmp, 0, sizeof(objtmp)); 1785 objtmp.path = NULL; 1786 objtmp.rtld = true; 1787 objtmp.mapbase = mapbase; 1788 #ifdef PIC 1789 objtmp.relocbase = mapbase; 1790 #endif 1791 if (RTLD_IS_DYNAMIC()) { 1792 objtmp.dynamic = rtld_dynamic(&objtmp); 1793 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1794 assert(objtmp.needed == NULL); 1795 #if !defined(__mips__) 1796 /* MIPS has a bogus DT_TEXTREL. */ 1797 assert(!objtmp.textrel); 1798 #endif 1799 1800 /* 1801 * Temporarily put the dynamic linker entry into the object list, so 1802 * that symbols can be found. 1803 */ 1804 1805 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1806 } 1807 1808 /* Initialize the object list. */ 1809 obj_tail = &obj_list; 1810 1811 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1812 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1813 1814 if (aux_info[AT_PAGESZ] != NULL) 1815 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1816 if (aux_info[AT_OSRELDATE] != NULL) 1817 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1818 1819 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1820 1821 /* Replace the path with a dynamically allocated copy. */ 1822 obj_rtld.path = xstrdup(PATH_RTLD); 1823 1824 r_debug.r_brk = r_debug_state; 1825 r_debug.r_state = RT_CONSISTENT; 1826 } 1827 1828 /* 1829 * Add the init functions from a needed object list (and its recursive 1830 * needed objects) to "list". This is not used directly; it is a helper 1831 * function for initlist_add_objects(). The write lock must be held 1832 * when this function is called. 1833 */ 1834 static void 1835 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1836 { 1837 /* Recursively process the successor needed objects. */ 1838 if (needed->next != NULL) 1839 initlist_add_neededs(needed->next, list); 1840 1841 /* Process the current needed object. */ 1842 if (needed->obj != NULL) 1843 initlist_add_objects(needed->obj, &needed->obj->next, list); 1844 } 1845 1846 /* 1847 * Scan all of the DAGs rooted in the range of objects from "obj" to 1848 * "tail" and add their init functions to "list". This recurses over 1849 * the DAGs and ensure the proper init ordering such that each object's 1850 * needed libraries are initialized before the object itself. At the 1851 * same time, this function adds the objects to the global finalization 1852 * list "list_fini" in the opposite order. The write lock must be 1853 * held when this function is called. 1854 */ 1855 static void 1856 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1857 { 1858 1859 if (obj->init_scanned || obj->init_done) 1860 return; 1861 obj->init_scanned = true; 1862 1863 /* Recursively process the successor objects. */ 1864 if (&obj->next != tail) 1865 initlist_add_objects(obj->next, tail, list); 1866 1867 /* Recursively process the needed objects. */ 1868 if (obj->needed != NULL) 1869 initlist_add_neededs(obj->needed, list); 1870 if (obj->needed_filtees != NULL) 1871 initlist_add_neededs(obj->needed_filtees, list); 1872 if (obj->needed_aux_filtees != NULL) 1873 initlist_add_neededs(obj->needed_aux_filtees, list); 1874 1875 /* Add the object to the init list. */ 1876 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1877 obj->init_array != (Elf_Addr)NULL) 1878 objlist_push_tail(list, obj); 1879 1880 /* Add the object to the global fini list in the reverse order. */ 1881 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1882 && !obj->on_fini_list) { 1883 objlist_push_head(&list_fini, obj); 1884 obj->on_fini_list = true; 1885 } 1886 } 1887 1888 #ifndef FPTR_TARGET 1889 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1890 #endif 1891 1892 static void 1893 free_needed_filtees(Needed_Entry *n) 1894 { 1895 Needed_Entry *needed, *needed1; 1896 1897 for (needed = n; needed != NULL; needed = needed->next) { 1898 if (needed->obj != NULL) { 1899 dlclose(needed->obj); 1900 needed->obj = NULL; 1901 } 1902 } 1903 for (needed = n; needed != NULL; needed = needed1) { 1904 needed1 = needed->next; 1905 free(needed); 1906 } 1907 } 1908 1909 static void 1910 unload_filtees(Obj_Entry *obj) 1911 { 1912 1913 free_needed_filtees(obj->needed_filtees); 1914 obj->needed_filtees = NULL; 1915 free_needed_filtees(obj->needed_aux_filtees); 1916 obj->needed_aux_filtees = NULL; 1917 obj->filtees_loaded = false; 1918 } 1919 1920 static void 1921 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1922 RtldLockState *lockstate) 1923 { 1924 1925 for (; needed != NULL; needed = needed->next) { 1926 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1927 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1928 RTLD_LOCAL, lockstate); 1929 } 1930 } 1931 1932 static void 1933 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1934 { 1935 1936 lock_restart_for_upgrade(lockstate); 1937 if (!obj->filtees_loaded) { 1938 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1939 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1940 obj->filtees_loaded = true; 1941 } 1942 } 1943 1944 static int 1945 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1946 { 1947 Obj_Entry *obj1; 1948 1949 for (; needed != NULL; needed = needed->next) { 1950 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1951 flags & ~RTLD_LO_NOLOAD); 1952 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1953 return (-1); 1954 } 1955 return (0); 1956 } 1957 1958 /* 1959 * Given a shared object, traverse its list of needed objects, and load 1960 * each of them. Returns 0 on success. Generates an error message and 1961 * returns -1 on failure. 1962 */ 1963 static int 1964 load_needed_objects(Obj_Entry *first, int flags) 1965 { 1966 Obj_Entry *obj; 1967 1968 for (obj = first; obj != NULL; obj = obj->next) { 1969 if (process_needed(obj, obj->needed, flags) == -1) 1970 return (-1); 1971 } 1972 return (0); 1973 } 1974 1975 static int 1976 load_preload_objects(void) 1977 { 1978 char *p = ld_preload; 1979 static const char delim[] = " \t:;"; 1980 1981 if (p == NULL) 1982 return 0; 1983 1984 p += strspn(p, delim); 1985 while (*p != '\0') { 1986 size_t len = strcspn(p, delim); 1987 char savech; 1988 1989 savech = p[len]; 1990 p[len] = '\0'; 1991 if (load_object(p, -1, NULL, 0) == NULL) 1992 return -1; /* XXX - cleanup */ 1993 p[len] = savech; 1994 p += len; 1995 p += strspn(p, delim); 1996 } 1997 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 1998 return 0; 1999 } 2000 2001 static const char * 2002 printable_path(const char *path) 2003 { 2004 2005 return (path == NULL ? "<unknown>" : path); 2006 } 2007 2008 /* 2009 * Load a shared object into memory, if it is not already loaded. The 2010 * object may be specified by name or by user-supplied file descriptor 2011 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2012 * duplicate is. 2013 * 2014 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2015 * on failure. 2016 */ 2017 static Obj_Entry * 2018 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2019 { 2020 Obj_Entry *obj; 2021 int fd; 2022 struct stat sb; 2023 char *path; 2024 2025 if (name != NULL) { 2026 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2027 if (object_match_name(obj, name)) 2028 return (obj); 2029 } 2030 2031 path = find_library(name, refobj); 2032 if (path == NULL) 2033 return (NULL); 2034 } else 2035 path = NULL; 2036 2037 /* 2038 * If we didn't find a match by pathname, or the name is not 2039 * supplied, open the file and check again by device and inode. 2040 * This avoids false mismatches caused by multiple links or ".." 2041 * in pathnames. 2042 * 2043 * To avoid a race, we open the file and use fstat() rather than 2044 * using stat(). 2045 */ 2046 fd = -1; 2047 if (fd_u == -1) { 2048 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2049 _rtld_error("Cannot open \"%s\"", path); 2050 free(path); 2051 return (NULL); 2052 } 2053 } else { 2054 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2055 if (fd == -1) { 2056 _rtld_error("Cannot dup fd"); 2057 free(path); 2058 return (NULL); 2059 } 2060 } 2061 if (fstat(fd, &sb) == -1) { 2062 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2063 close(fd); 2064 free(path); 2065 return NULL; 2066 } 2067 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2068 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2069 break; 2070 if (obj != NULL && name != NULL) { 2071 object_add_name(obj, name); 2072 free(path); 2073 close(fd); 2074 return obj; 2075 } 2076 if (flags & RTLD_LO_NOLOAD) { 2077 free(path); 2078 close(fd); 2079 return (NULL); 2080 } 2081 2082 /* First use of this object, so we must map it in */ 2083 obj = do_load_object(fd, name, path, &sb, flags); 2084 if (obj == NULL) 2085 free(path); 2086 close(fd); 2087 2088 return obj; 2089 } 2090 2091 static Obj_Entry * 2092 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2093 int flags) 2094 { 2095 Obj_Entry *obj; 2096 struct statfs fs; 2097 2098 /* 2099 * but first, make sure that environment variables haven't been 2100 * used to circumvent the noexec flag on a filesystem. 2101 */ 2102 if (dangerous_ld_env) { 2103 if (fstatfs(fd, &fs) != 0) { 2104 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2105 return NULL; 2106 } 2107 if (fs.f_flags & MNT_NOEXEC) { 2108 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2109 return NULL; 2110 } 2111 } 2112 dbg("loading \"%s\"", printable_path(path)); 2113 obj = map_object(fd, printable_path(path), sbp); 2114 if (obj == NULL) 2115 return NULL; 2116 2117 /* 2118 * If DT_SONAME is present in the object, digest_dynamic2 already 2119 * added it to the object names. 2120 */ 2121 if (name != NULL) 2122 object_add_name(obj, name); 2123 obj->path = path; 2124 digest_dynamic(obj, 0); 2125 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2126 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2127 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2128 RTLD_LO_DLOPEN) { 2129 dbg("refusing to load non-loadable \"%s\"", obj->path); 2130 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2131 munmap(obj->mapbase, obj->mapsize); 2132 obj_free(obj); 2133 return (NULL); 2134 } 2135 2136 *obj_tail = obj; 2137 obj_tail = &obj->next; 2138 obj_count++; 2139 obj_loads++; 2140 linkmap_add(obj); /* for GDB & dlinfo() */ 2141 max_stack_flags |= obj->stack_flags; 2142 2143 dbg(" %p .. %p: %s", obj->mapbase, 2144 obj->mapbase + obj->mapsize - 1, obj->path); 2145 if (obj->textrel) 2146 dbg(" WARNING: %s has impure text", obj->path); 2147 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2148 obj->path); 2149 2150 return obj; 2151 } 2152 2153 static Obj_Entry * 2154 obj_from_addr(const void *addr) 2155 { 2156 Obj_Entry *obj; 2157 2158 for (obj = obj_list; obj != NULL; obj = obj->next) { 2159 if (addr < (void *) obj->mapbase) 2160 continue; 2161 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2162 return obj; 2163 } 2164 return NULL; 2165 } 2166 2167 static void 2168 preinit_main(void) 2169 { 2170 Elf_Addr *preinit_addr; 2171 int index; 2172 2173 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2174 if (preinit_addr == NULL) 2175 return; 2176 2177 for (index = 0; index < obj_main->preinit_array_num; index++) { 2178 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2179 dbg("calling preinit function for %s at %p", obj_main->path, 2180 (void *)preinit_addr[index]); 2181 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2182 0, 0, obj_main->path); 2183 call_init_pointer(obj_main, preinit_addr[index]); 2184 } 2185 } 2186 } 2187 2188 /* 2189 * Call the finalization functions for each of the objects in "list" 2190 * belonging to the DAG of "root" and referenced once. If NULL "root" 2191 * is specified, every finalization function will be called regardless 2192 * of the reference count and the list elements won't be freed. All of 2193 * the objects are expected to have non-NULL fini functions. 2194 */ 2195 static void 2196 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2197 { 2198 Objlist_Entry *elm; 2199 char *saved_msg; 2200 Elf_Addr *fini_addr; 2201 int index; 2202 2203 assert(root == NULL || root->refcount == 1); 2204 2205 /* 2206 * Preserve the current error message since a fini function might 2207 * call into the dynamic linker and overwrite it. 2208 */ 2209 saved_msg = errmsg_save(); 2210 do { 2211 STAILQ_FOREACH(elm, list, link) { 2212 if (root != NULL && (elm->obj->refcount != 1 || 2213 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2214 continue; 2215 /* Remove object from fini list to prevent recursive invocation. */ 2216 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2217 /* 2218 * XXX: If a dlopen() call references an object while the 2219 * fini function is in progress, we might end up trying to 2220 * unload the referenced object in dlclose() or the object 2221 * won't be unloaded although its fini function has been 2222 * called. 2223 */ 2224 lock_release(rtld_bind_lock, lockstate); 2225 2226 /* 2227 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2228 * When this happens, DT_FINI_ARRAY is processed first. 2229 */ 2230 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2231 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2232 for (index = elm->obj->fini_array_num - 1; index >= 0; 2233 index--) { 2234 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2235 dbg("calling fini function for %s at %p", 2236 elm->obj->path, (void *)fini_addr[index]); 2237 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2238 (void *)fini_addr[index], 0, 0, elm->obj->path); 2239 call_initfini_pointer(elm->obj, fini_addr[index]); 2240 } 2241 } 2242 } 2243 if (elm->obj->fini != (Elf_Addr)NULL) { 2244 dbg("calling fini function for %s at %p", elm->obj->path, 2245 (void *)elm->obj->fini); 2246 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2247 0, 0, elm->obj->path); 2248 call_initfini_pointer(elm->obj, elm->obj->fini); 2249 } 2250 wlock_acquire(rtld_bind_lock, lockstate); 2251 /* No need to free anything if process is going down. */ 2252 if (root != NULL) 2253 free(elm); 2254 /* 2255 * We must restart the list traversal after every fini call 2256 * because a dlclose() call from the fini function or from 2257 * another thread might have modified the reference counts. 2258 */ 2259 break; 2260 } 2261 } while (elm != NULL); 2262 errmsg_restore(saved_msg); 2263 } 2264 2265 /* 2266 * Call the initialization functions for each of the objects in 2267 * "list". All of the objects are expected to have non-NULL init 2268 * functions. 2269 */ 2270 static void 2271 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2272 { 2273 Objlist_Entry *elm; 2274 Obj_Entry *obj; 2275 char *saved_msg; 2276 Elf_Addr *init_addr; 2277 int index; 2278 2279 /* 2280 * Clean init_scanned flag so that objects can be rechecked and 2281 * possibly initialized earlier if any of vectors called below 2282 * cause the change by using dlopen. 2283 */ 2284 for (obj = obj_list; obj != NULL; obj = obj->next) 2285 obj->init_scanned = false; 2286 2287 /* 2288 * Preserve the current error message since an init function might 2289 * call into the dynamic linker and overwrite it. 2290 */ 2291 saved_msg = errmsg_save(); 2292 STAILQ_FOREACH(elm, list, link) { 2293 if (elm->obj->init_done) /* Initialized early. */ 2294 continue; 2295 /* 2296 * Race: other thread might try to use this object before current 2297 * one completes the initilization. Not much can be done here 2298 * without better locking. 2299 */ 2300 elm->obj->init_done = true; 2301 lock_release(rtld_bind_lock, lockstate); 2302 2303 /* 2304 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2305 * When this happens, DT_INIT is processed first. 2306 */ 2307 if (elm->obj->init != (Elf_Addr)NULL) { 2308 dbg("calling init function for %s at %p", elm->obj->path, 2309 (void *)elm->obj->init); 2310 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2311 0, 0, elm->obj->path); 2312 call_initfini_pointer(elm->obj, elm->obj->init); 2313 } 2314 init_addr = (Elf_Addr *)elm->obj->init_array; 2315 if (init_addr != NULL) { 2316 for (index = 0; index < elm->obj->init_array_num; index++) { 2317 if (init_addr[index] != 0 && init_addr[index] != 1) { 2318 dbg("calling init function for %s at %p", elm->obj->path, 2319 (void *)init_addr[index]); 2320 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2321 (void *)init_addr[index], 0, 0, elm->obj->path); 2322 call_init_pointer(elm->obj, init_addr[index]); 2323 } 2324 } 2325 } 2326 wlock_acquire(rtld_bind_lock, lockstate); 2327 } 2328 errmsg_restore(saved_msg); 2329 } 2330 2331 static void 2332 objlist_clear(Objlist *list) 2333 { 2334 Objlist_Entry *elm; 2335 2336 while (!STAILQ_EMPTY(list)) { 2337 elm = STAILQ_FIRST(list); 2338 STAILQ_REMOVE_HEAD(list, link); 2339 free(elm); 2340 } 2341 } 2342 2343 static Objlist_Entry * 2344 objlist_find(Objlist *list, const Obj_Entry *obj) 2345 { 2346 Objlist_Entry *elm; 2347 2348 STAILQ_FOREACH(elm, list, link) 2349 if (elm->obj == obj) 2350 return elm; 2351 return NULL; 2352 } 2353 2354 static void 2355 objlist_init(Objlist *list) 2356 { 2357 STAILQ_INIT(list); 2358 } 2359 2360 static void 2361 objlist_push_head(Objlist *list, Obj_Entry *obj) 2362 { 2363 Objlist_Entry *elm; 2364 2365 elm = NEW(Objlist_Entry); 2366 elm->obj = obj; 2367 STAILQ_INSERT_HEAD(list, elm, link); 2368 } 2369 2370 static void 2371 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2372 { 2373 Objlist_Entry *elm; 2374 2375 elm = NEW(Objlist_Entry); 2376 elm->obj = obj; 2377 STAILQ_INSERT_TAIL(list, elm, link); 2378 } 2379 2380 static void 2381 objlist_remove(Objlist *list, Obj_Entry *obj) 2382 { 2383 Objlist_Entry *elm; 2384 2385 if ((elm = objlist_find(list, obj)) != NULL) { 2386 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2387 free(elm); 2388 } 2389 } 2390 2391 /* 2392 * Relocate dag rooted in the specified object. 2393 * Returns 0 on success, or -1 on failure. 2394 */ 2395 2396 static int 2397 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2398 int flags, RtldLockState *lockstate) 2399 { 2400 Objlist_Entry *elm; 2401 int error; 2402 2403 error = 0; 2404 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2405 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2406 lockstate); 2407 if (error == -1) 2408 break; 2409 } 2410 return (error); 2411 } 2412 2413 /* 2414 * Relocate single object. 2415 * Returns 0 on success, or -1 on failure. 2416 */ 2417 static int 2418 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2419 int flags, RtldLockState *lockstate) 2420 { 2421 2422 if (obj->relocated) 2423 return (0); 2424 obj->relocated = true; 2425 if (obj != rtldobj) 2426 dbg("relocating \"%s\"", obj->path); 2427 2428 if (obj->symtab == NULL || obj->strtab == NULL || 2429 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2430 _rtld_error("%s: Shared object has no run-time symbol table", 2431 obj->path); 2432 return (-1); 2433 } 2434 2435 if (obj->textrel) { 2436 /* There are relocations to the write-protected text segment. */ 2437 if (mprotect(obj->mapbase, obj->textsize, 2438 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2439 _rtld_error("%s: Cannot write-enable text segment: %s", 2440 obj->path, rtld_strerror(errno)); 2441 return (-1); 2442 } 2443 } 2444 2445 /* Process the non-PLT relocations. */ 2446 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2447 return (-1); 2448 2449 if (obj->textrel) { /* Re-protected the text segment. */ 2450 if (mprotect(obj->mapbase, obj->textsize, 2451 PROT_READ|PROT_EXEC) == -1) { 2452 _rtld_error("%s: Cannot write-protect text segment: %s", 2453 obj->path, rtld_strerror(errno)); 2454 return (-1); 2455 } 2456 } 2457 2458 2459 /* Set the special PLT or GOT entries. */ 2460 init_pltgot(obj); 2461 2462 /* Process the PLT relocations. */ 2463 if (reloc_plt(obj) == -1) 2464 return (-1); 2465 /* Relocate the jump slots if we are doing immediate binding. */ 2466 if (obj->bind_now || bind_now) 2467 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2468 return (-1); 2469 2470 if (obj->relro_size > 0) { 2471 if (mprotect(obj->relro_page, obj->relro_size, 2472 PROT_READ) == -1) { 2473 _rtld_error("%s: Cannot enforce relro protection: %s", 2474 obj->path, rtld_strerror(errno)); 2475 return (-1); 2476 } 2477 } 2478 2479 /* 2480 * Set up the magic number and version in the Obj_Entry. These 2481 * were checked in the crt1.o from the original ElfKit, so we 2482 * set them for backward compatibility. 2483 */ 2484 obj->magic = RTLD_MAGIC; 2485 obj->version = RTLD_VERSION; 2486 2487 return (0); 2488 } 2489 2490 /* 2491 * Relocate newly-loaded shared objects. The argument is a pointer to 2492 * the Obj_Entry for the first such object. All objects from the first 2493 * to the end of the list of objects are relocated. Returns 0 on success, 2494 * or -1 on failure. 2495 */ 2496 static int 2497 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2498 int flags, RtldLockState *lockstate) 2499 { 2500 Obj_Entry *obj; 2501 int error; 2502 2503 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2504 error = relocate_object(obj, bind_now, rtldobj, flags, 2505 lockstate); 2506 if (error == -1) 2507 break; 2508 } 2509 return (error); 2510 } 2511 2512 /* 2513 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2514 * referencing STT_GNU_IFUNC symbols is postponed till the other 2515 * relocations are done. The indirect functions specified as 2516 * ifunc are allowed to call other symbols, so we need to have 2517 * objects relocated before asking for resolution from indirects. 2518 * 2519 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2520 * instead of the usual lazy handling of PLT slots. It is 2521 * consistent with how GNU does it. 2522 */ 2523 static int 2524 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2525 RtldLockState *lockstate) 2526 { 2527 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2528 return (-1); 2529 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2530 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2531 return (-1); 2532 return (0); 2533 } 2534 2535 static int 2536 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2537 RtldLockState *lockstate) 2538 { 2539 Obj_Entry *obj; 2540 2541 for (obj = first; obj != NULL; obj = obj->next) { 2542 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2543 return (-1); 2544 } 2545 return (0); 2546 } 2547 2548 static int 2549 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2550 RtldLockState *lockstate) 2551 { 2552 Objlist_Entry *elm; 2553 2554 STAILQ_FOREACH(elm, list, link) { 2555 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2556 lockstate) == -1) 2557 return (-1); 2558 } 2559 return (0); 2560 } 2561 2562 /* 2563 * Cleanup procedure. It will be called (by the atexit mechanism) just 2564 * before the process exits. 2565 */ 2566 static void 2567 rtld_exit(void) 2568 { 2569 RtldLockState lockstate; 2570 2571 wlock_acquire(rtld_bind_lock, &lockstate); 2572 dbg("rtld_exit()"); 2573 objlist_call_fini(&list_fini, NULL, &lockstate); 2574 /* No need to remove the items from the list, since we are exiting. */ 2575 if (!libmap_disable) 2576 lm_fini(); 2577 lock_release(rtld_bind_lock, &lockstate); 2578 } 2579 2580 /* 2581 * Iterate over a search path, translate each element, and invoke the 2582 * callback on the result. 2583 */ 2584 static void * 2585 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2586 { 2587 const char *trans; 2588 if (path == NULL) 2589 return (NULL); 2590 2591 path += strspn(path, ":;"); 2592 while (*path != '\0') { 2593 size_t len; 2594 char *res; 2595 2596 len = strcspn(path, ":;"); 2597 trans = lm_findn(NULL, path, len); 2598 if (trans) 2599 res = callback(trans, strlen(trans), arg); 2600 else 2601 res = callback(path, len, arg); 2602 2603 if (res != NULL) 2604 return (res); 2605 2606 path += len; 2607 path += strspn(path, ":;"); 2608 } 2609 2610 return (NULL); 2611 } 2612 2613 struct try_library_args { 2614 const char *name; 2615 size_t namelen; 2616 char *buffer; 2617 size_t buflen; 2618 }; 2619 2620 static void * 2621 try_library_path(const char *dir, size_t dirlen, void *param) 2622 { 2623 struct try_library_args *arg; 2624 2625 arg = param; 2626 if (*dir == '/' || trust) { 2627 char *pathname; 2628 2629 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2630 return (NULL); 2631 2632 pathname = arg->buffer; 2633 strncpy(pathname, dir, dirlen); 2634 pathname[dirlen] = '/'; 2635 strcpy(pathname + dirlen + 1, arg->name); 2636 2637 dbg(" Trying \"%s\"", pathname); 2638 if (access(pathname, F_OK) == 0) { /* We found it */ 2639 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2640 strcpy(pathname, arg->buffer); 2641 return (pathname); 2642 } 2643 } 2644 return (NULL); 2645 } 2646 2647 static char * 2648 search_library_path(const char *name, const char *path) 2649 { 2650 char *p; 2651 struct try_library_args arg; 2652 2653 if (path == NULL) 2654 return NULL; 2655 2656 arg.name = name; 2657 arg.namelen = strlen(name); 2658 arg.buffer = xmalloc(PATH_MAX); 2659 arg.buflen = PATH_MAX; 2660 2661 p = path_enumerate(path, try_library_path, &arg); 2662 2663 free(arg.buffer); 2664 2665 return (p); 2666 } 2667 2668 int 2669 dlclose(void *handle) 2670 { 2671 Obj_Entry *root; 2672 RtldLockState lockstate; 2673 2674 wlock_acquire(rtld_bind_lock, &lockstate); 2675 root = dlcheck(handle); 2676 if (root == NULL) { 2677 lock_release(rtld_bind_lock, &lockstate); 2678 return -1; 2679 } 2680 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2681 root->path); 2682 2683 /* Unreference the object and its dependencies. */ 2684 root->dl_refcount--; 2685 2686 if (root->refcount == 1) { 2687 /* 2688 * The object will be no longer referenced, so we must unload it. 2689 * First, call the fini functions. 2690 */ 2691 objlist_call_fini(&list_fini, root, &lockstate); 2692 2693 unref_dag(root); 2694 2695 /* Finish cleaning up the newly-unreferenced objects. */ 2696 GDB_STATE(RT_DELETE,&root->linkmap); 2697 unload_object(root); 2698 GDB_STATE(RT_CONSISTENT,NULL); 2699 } else 2700 unref_dag(root); 2701 2702 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2703 lock_release(rtld_bind_lock, &lockstate); 2704 return 0; 2705 } 2706 2707 char * 2708 dlerror(void) 2709 { 2710 char *msg = error_message; 2711 error_message = NULL; 2712 return msg; 2713 } 2714 2715 /* 2716 * This function is deprecated and has no effect. 2717 */ 2718 void 2719 dllockinit(void *context, 2720 void *(*lock_create)(void *context), 2721 void (*rlock_acquire)(void *lock), 2722 void (*wlock_acquire)(void *lock), 2723 void (*lock_release)(void *lock), 2724 void (*lock_destroy)(void *lock), 2725 void (*context_destroy)(void *context)) 2726 { 2727 static void *cur_context; 2728 static void (*cur_context_destroy)(void *); 2729 2730 /* Just destroy the context from the previous call, if necessary. */ 2731 if (cur_context_destroy != NULL) 2732 cur_context_destroy(cur_context); 2733 cur_context = context; 2734 cur_context_destroy = context_destroy; 2735 } 2736 2737 void * 2738 dlopen(const char *name, int mode) 2739 { 2740 2741 return (rtld_dlopen(name, -1, mode)); 2742 } 2743 2744 void * 2745 fdlopen(int fd, int mode) 2746 { 2747 2748 return (rtld_dlopen(NULL, fd, mode)); 2749 } 2750 2751 static void * 2752 rtld_dlopen(const char *name, int fd, int mode) 2753 { 2754 RtldLockState lockstate; 2755 int lo_flags; 2756 2757 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2758 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2759 if (ld_tracing != NULL) { 2760 rlock_acquire(rtld_bind_lock, &lockstate); 2761 if (sigsetjmp(lockstate.env, 0) != 0) 2762 lock_upgrade(rtld_bind_lock, &lockstate); 2763 environ = (char **)*get_program_var_addr("environ", &lockstate); 2764 lock_release(rtld_bind_lock, &lockstate); 2765 } 2766 lo_flags = RTLD_LO_DLOPEN; 2767 if (mode & RTLD_NODELETE) 2768 lo_flags |= RTLD_LO_NODELETE; 2769 if (mode & RTLD_NOLOAD) 2770 lo_flags |= RTLD_LO_NOLOAD; 2771 if (ld_tracing != NULL) 2772 lo_flags |= RTLD_LO_TRACE; 2773 2774 return (dlopen_object(name, fd, obj_main, lo_flags, 2775 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2776 } 2777 2778 static void 2779 dlopen_cleanup(Obj_Entry *obj) 2780 { 2781 2782 obj->dl_refcount--; 2783 unref_dag(obj); 2784 if (obj->refcount == 0) 2785 unload_object(obj); 2786 } 2787 2788 static Obj_Entry * 2789 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2790 int mode, RtldLockState *lockstate) 2791 { 2792 Obj_Entry **old_obj_tail; 2793 Obj_Entry *obj; 2794 Objlist initlist; 2795 RtldLockState mlockstate; 2796 int result; 2797 2798 objlist_init(&initlist); 2799 2800 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2801 wlock_acquire(rtld_bind_lock, &mlockstate); 2802 lockstate = &mlockstate; 2803 } 2804 GDB_STATE(RT_ADD,NULL); 2805 2806 old_obj_tail = obj_tail; 2807 obj = NULL; 2808 if (name == NULL && fd == -1) { 2809 obj = obj_main; 2810 obj->refcount++; 2811 } else { 2812 obj = load_object(name, fd, refobj, lo_flags); 2813 } 2814 2815 if (obj) { 2816 obj->dl_refcount++; 2817 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2818 objlist_push_tail(&list_global, obj); 2819 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2820 assert(*old_obj_tail == obj); 2821 result = load_needed_objects(obj, 2822 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2823 init_dag(obj); 2824 ref_dag(obj); 2825 if (result != -1) 2826 result = rtld_verify_versions(&obj->dagmembers); 2827 if (result != -1 && ld_tracing) 2828 goto trace; 2829 if (result == -1 || relocate_object_dag(obj, 2830 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2831 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2832 lockstate) == -1) { 2833 dlopen_cleanup(obj); 2834 obj = NULL; 2835 } else if (lo_flags & RTLD_LO_EARLY) { 2836 /* 2837 * Do not call the init functions for early loaded 2838 * filtees. The image is still not initialized enough 2839 * for them to work. 2840 * 2841 * Our object is found by the global object list and 2842 * will be ordered among all init calls done right 2843 * before transferring control to main. 2844 */ 2845 } else { 2846 /* Make list of init functions to call. */ 2847 initlist_add_objects(obj, &obj->next, &initlist); 2848 } 2849 /* 2850 * Process all no_delete objects here, given them own 2851 * DAGs to prevent their dependencies from being unloaded. 2852 * This has to be done after we have loaded all of the 2853 * dependencies, so that we do not miss any. 2854 */ 2855 if (obj != NULL) 2856 process_nodelete(obj); 2857 } else { 2858 /* 2859 * Bump the reference counts for objects on this DAG. If 2860 * this is the first dlopen() call for the object that was 2861 * already loaded as a dependency, initialize the dag 2862 * starting at it. 2863 */ 2864 init_dag(obj); 2865 ref_dag(obj); 2866 2867 if ((lo_flags & RTLD_LO_TRACE) != 0) 2868 goto trace; 2869 } 2870 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2871 obj->z_nodelete) && !obj->ref_nodel) { 2872 dbg("obj %s nodelete", obj->path); 2873 ref_dag(obj); 2874 obj->z_nodelete = obj->ref_nodel = true; 2875 } 2876 } 2877 2878 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2879 name); 2880 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2881 2882 if (!(lo_flags & RTLD_LO_EARLY)) { 2883 map_stacks_exec(lockstate); 2884 } 2885 2886 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2887 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2888 lockstate) == -1) { 2889 objlist_clear(&initlist); 2890 dlopen_cleanup(obj); 2891 if (lockstate == &mlockstate) 2892 lock_release(rtld_bind_lock, lockstate); 2893 return (NULL); 2894 } 2895 2896 if (!(lo_flags & RTLD_LO_EARLY)) { 2897 /* Call the init functions. */ 2898 objlist_call_init(&initlist, lockstate); 2899 } 2900 objlist_clear(&initlist); 2901 if (lockstate == &mlockstate) 2902 lock_release(rtld_bind_lock, lockstate); 2903 return obj; 2904 trace: 2905 trace_loaded_objects(obj); 2906 if (lockstate == &mlockstate) 2907 lock_release(rtld_bind_lock, lockstate); 2908 exit(0); 2909 } 2910 2911 static void * 2912 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2913 int flags) 2914 { 2915 DoneList donelist; 2916 const Obj_Entry *obj, *defobj; 2917 const Elf_Sym *def; 2918 SymLook req; 2919 RtldLockState lockstate; 2920 #ifndef __ia64__ 2921 tls_index ti; 2922 #endif 2923 int res; 2924 2925 def = NULL; 2926 defobj = NULL; 2927 symlook_init(&req, name); 2928 req.ventry = ve; 2929 req.flags = flags | SYMLOOK_IN_PLT; 2930 req.lockstate = &lockstate; 2931 2932 rlock_acquire(rtld_bind_lock, &lockstate); 2933 if (sigsetjmp(lockstate.env, 0) != 0) 2934 lock_upgrade(rtld_bind_lock, &lockstate); 2935 if (handle == NULL || handle == RTLD_NEXT || 2936 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2937 2938 if ((obj = obj_from_addr(retaddr)) == NULL) { 2939 _rtld_error("Cannot determine caller's shared object"); 2940 lock_release(rtld_bind_lock, &lockstate); 2941 return NULL; 2942 } 2943 if (handle == NULL) { /* Just the caller's shared object. */ 2944 res = symlook_obj(&req, obj); 2945 if (res == 0) { 2946 def = req.sym_out; 2947 defobj = req.defobj_out; 2948 } 2949 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2950 handle == RTLD_SELF) { /* ... caller included */ 2951 if (handle == RTLD_NEXT) 2952 obj = obj->next; 2953 for (; obj != NULL; obj = obj->next) { 2954 res = symlook_obj(&req, obj); 2955 if (res == 0) { 2956 if (def == NULL || 2957 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2958 def = req.sym_out; 2959 defobj = req.defobj_out; 2960 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2961 break; 2962 } 2963 } 2964 } 2965 /* 2966 * Search the dynamic linker itself, and possibly resolve the 2967 * symbol from there. This is how the application links to 2968 * dynamic linker services such as dlopen. 2969 */ 2970 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 2971 res = symlook_obj(&req, &obj_rtld); 2972 if (res == 0) { 2973 def = req.sym_out; 2974 defobj = req.defobj_out; 2975 } 2976 } 2977 } else { 2978 assert(handle == RTLD_DEFAULT); 2979 res = symlook_default(&req, obj); 2980 if (res == 0) { 2981 defobj = req.defobj_out; 2982 def = req.sym_out; 2983 } 2984 } 2985 } else { 2986 if ((obj = dlcheck(handle)) == NULL) { 2987 lock_release(rtld_bind_lock, &lockstate); 2988 return NULL; 2989 } 2990 2991 donelist_init(&donelist); 2992 if (obj->mainprog) { 2993 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 2994 res = symlook_global(&req, &donelist); 2995 if (res == 0) { 2996 def = req.sym_out; 2997 defobj = req.defobj_out; 2998 } 2999 /* 3000 * Search the dynamic linker itself, and possibly resolve the 3001 * symbol from there. This is how the application links to 3002 * dynamic linker services such as dlopen. 3003 */ 3004 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3005 res = symlook_obj(&req, &obj_rtld); 3006 if (res == 0) { 3007 def = req.sym_out; 3008 defobj = req.defobj_out; 3009 } 3010 } 3011 } 3012 else { 3013 /* Search the whole DAG rooted at the given object. */ 3014 res = symlook_list(&req, &obj->dagmembers, &donelist); 3015 if (res == 0) { 3016 def = req.sym_out; 3017 defobj = req.defobj_out; 3018 } 3019 } 3020 } 3021 3022 if (def != NULL) { 3023 lock_release(rtld_bind_lock, &lockstate); 3024 3025 /* 3026 * The value required by the caller is derived from the value 3027 * of the symbol. For the ia64 architecture, we need to 3028 * construct a function descriptor which the caller can use to 3029 * call the function with the right 'gp' value. For other 3030 * architectures and for non-functions, the value is simply 3031 * the relocated value of the symbol. 3032 */ 3033 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3034 return (make_function_pointer(def, defobj)); 3035 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3036 return (rtld_resolve_ifunc(defobj, def)); 3037 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3038 #ifdef __ia64__ 3039 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3040 #else 3041 ti.ti_module = defobj->tlsindex; 3042 ti.ti_offset = def->st_value; 3043 return (__tls_get_addr(&ti)); 3044 #endif 3045 } else 3046 return (defobj->relocbase + def->st_value); 3047 } 3048 3049 _rtld_error("Undefined symbol \"%s\"", name); 3050 lock_release(rtld_bind_lock, &lockstate); 3051 return NULL; 3052 } 3053 3054 void * 3055 dlsym(void *handle, const char *name) 3056 { 3057 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3058 SYMLOOK_DLSYM); 3059 } 3060 3061 dlfunc_t 3062 dlfunc(void *handle, const char *name) 3063 { 3064 union { 3065 void *d; 3066 dlfunc_t f; 3067 } rv; 3068 3069 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3070 SYMLOOK_DLSYM); 3071 return (rv.f); 3072 } 3073 3074 void * 3075 dlvsym(void *handle, const char *name, const char *version) 3076 { 3077 Ver_Entry ventry; 3078 3079 ventry.name = version; 3080 ventry.file = NULL; 3081 ventry.hash = elf_hash(version); 3082 ventry.flags= 0; 3083 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3084 SYMLOOK_DLSYM); 3085 } 3086 3087 int 3088 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3089 { 3090 const Obj_Entry *obj; 3091 RtldLockState lockstate; 3092 3093 rlock_acquire(rtld_bind_lock, &lockstate); 3094 obj = obj_from_addr(addr); 3095 if (obj == NULL) { 3096 _rtld_error("No shared object contains address"); 3097 lock_release(rtld_bind_lock, &lockstate); 3098 return (0); 3099 } 3100 rtld_fill_dl_phdr_info(obj, phdr_info); 3101 lock_release(rtld_bind_lock, &lockstate); 3102 return (1); 3103 } 3104 3105 int 3106 dladdr(const void *addr, Dl_info *info) 3107 { 3108 const Obj_Entry *obj; 3109 const Elf_Sym *def; 3110 void *symbol_addr; 3111 unsigned long symoffset; 3112 RtldLockState lockstate; 3113 3114 rlock_acquire(rtld_bind_lock, &lockstate); 3115 obj = obj_from_addr(addr); 3116 if (obj == NULL) { 3117 _rtld_error("No shared object contains address"); 3118 lock_release(rtld_bind_lock, &lockstate); 3119 return 0; 3120 } 3121 info->dli_fname = obj->path; 3122 info->dli_fbase = obj->mapbase; 3123 info->dli_saddr = (void *)0; 3124 info->dli_sname = NULL; 3125 3126 /* 3127 * Walk the symbol list looking for the symbol whose address is 3128 * closest to the address sent in. 3129 */ 3130 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3131 def = obj->symtab + symoffset; 3132 3133 /* 3134 * For skip the symbol if st_shndx is either SHN_UNDEF or 3135 * SHN_COMMON. 3136 */ 3137 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3138 continue; 3139 3140 /* 3141 * If the symbol is greater than the specified address, or if it 3142 * is further away from addr than the current nearest symbol, 3143 * then reject it. 3144 */ 3145 symbol_addr = obj->relocbase + def->st_value; 3146 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3147 continue; 3148 3149 /* Update our idea of the nearest symbol. */ 3150 info->dli_sname = obj->strtab + def->st_name; 3151 info->dli_saddr = symbol_addr; 3152 3153 /* Exact match? */ 3154 if (info->dli_saddr == addr) 3155 break; 3156 } 3157 lock_release(rtld_bind_lock, &lockstate); 3158 return 1; 3159 } 3160 3161 int 3162 dlinfo(void *handle, int request, void *p) 3163 { 3164 const Obj_Entry *obj; 3165 RtldLockState lockstate; 3166 int error; 3167 3168 rlock_acquire(rtld_bind_lock, &lockstate); 3169 3170 if (handle == NULL || handle == RTLD_SELF) { 3171 void *retaddr; 3172 3173 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3174 if ((obj = obj_from_addr(retaddr)) == NULL) 3175 _rtld_error("Cannot determine caller's shared object"); 3176 } else 3177 obj = dlcheck(handle); 3178 3179 if (obj == NULL) { 3180 lock_release(rtld_bind_lock, &lockstate); 3181 return (-1); 3182 } 3183 3184 error = 0; 3185 switch (request) { 3186 case RTLD_DI_LINKMAP: 3187 *((struct link_map const **)p) = &obj->linkmap; 3188 break; 3189 case RTLD_DI_ORIGIN: 3190 error = rtld_dirname(obj->path, p); 3191 break; 3192 3193 case RTLD_DI_SERINFOSIZE: 3194 case RTLD_DI_SERINFO: 3195 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3196 break; 3197 3198 default: 3199 _rtld_error("Invalid request %d passed to dlinfo()", request); 3200 error = -1; 3201 } 3202 3203 lock_release(rtld_bind_lock, &lockstate); 3204 3205 return (error); 3206 } 3207 3208 static void 3209 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3210 { 3211 3212 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3213 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 3214 STAILQ_FIRST(&obj->names)->name : obj->path; 3215 phdr_info->dlpi_phdr = obj->phdr; 3216 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3217 phdr_info->dlpi_tls_modid = obj->tlsindex; 3218 phdr_info->dlpi_tls_data = obj->tlsinit; 3219 phdr_info->dlpi_adds = obj_loads; 3220 phdr_info->dlpi_subs = obj_loads - obj_count; 3221 } 3222 3223 int 3224 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3225 { 3226 struct dl_phdr_info phdr_info; 3227 const Obj_Entry *obj; 3228 RtldLockState bind_lockstate, phdr_lockstate; 3229 int error; 3230 3231 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3232 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3233 3234 error = 0; 3235 3236 for (obj = obj_list; obj != NULL; obj = obj->next) { 3237 rtld_fill_dl_phdr_info(obj, &phdr_info); 3238 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3239 break; 3240 3241 } 3242 lock_release(rtld_bind_lock, &bind_lockstate); 3243 lock_release(rtld_phdr_lock, &phdr_lockstate); 3244 3245 return (error); 3246 } 3247 3248 static void * 3249 fill_search_info(const char *dir, size_t dirlen, void *param) 3250 { 3251 struct fill_search_info_args *arg; 3252 3253 arg = param; 3254 3255 if (arg->request == RTLD_DI_SERINFOSIZE) { 3256 arg->serinfo->dls_cnt ++; 3257 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3258 } else { 3259 struct dl_serpath *s_entry; 3260 3261 s_entry = arg->serpath; 3262 s_entry->dls_name = arg->strspace; 3263 s_entry->dls_flags = arg->flags; 3264 3265 strncpy(arg->strspace, dir, dirlen); 3266 arg->strspace[dirlen] = '\0'; 3267 3268 arg->strspace += dirlen + 1; 3269 arg->serpath++; 3270 } 3271 3272 return (NULL); 3273 } 3274 3275 static int 3276 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3277 { 3278 struct dl_serinfo _info; 3279 struct fill_search_info_args args; 3280 3281 args.request = RTLD_DI_SERINFOSIZE; 3282 args.serinfo = &_info; 3283 3284 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3285 _info.dls_cnt = 0; 3286 3287 path_enumerate(obj->rpath, fill_search_info, &args); 3288 path_enumerate(ld_library_path, fill_search_info, &args); 3289 path_enumerate(obj->runpath, fill_search_info, &args); 3290 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3291 if (!obj->z_nodeflib) 3292 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3293 3294 3295 if (request == RTLD_DI_SERINFOSIZE) { 3296 info->dls_size = _info.dls_size; 3297 info->dls_cnt = _info.dls_cnt; 3298 return (0); 3299 } 3300 3301 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3302 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3303 return (-1); 3304 } 3305 3306 args.request = RTLD_DI_SERINFO; 3307 args.serinfo = info; 3308 args.serpath = &info->dls_serpath[0]; 3309 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3310 3311 args.flags = LA_SER_RUNPATH; 3312 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3313 return (-1); 3314 3315 args.flags = LA_SER_LIBPATH; 3316 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3317 return (-1); 3318 3319 args.flags = LA_SER_RUNPATH; 3320 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3321 return (-1); 3322 3323 args.flags = LA_SER_CONFIG; 3324 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3325 != NULL) 3326 return (-1); 3327 3328 args.flags = LA_SER_DEFAULT; 3329 if (!obj->z_nodeflib && 3330 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3331 return (-1); 3332 return (0); 3333 } 3334 3335 static int 3336 rtld_dirname(const char *path, char *bname) 3337 { 3338 const char *endp; 3339 3340 /* Empty or NULL string gets treated as "." */ 3341 if (path == NULL || *path == '\0') { 3342 bname[0] = '.'; 3343 bname[1] = '\0'; 3344 return (0); 3345 } 3346 3347 /* Strip trailing slashes */ 3348 endp = path + strlen(path) - 1; 3349 while (endp > path && *endp == '/') 3350 endp--; 3351 3352 /* Find the start of the dir */ 3353 while (endp > path && *endp != '/') 3354 endp--; 3355 3356 /* Either the dir is "/" or there are no slashes */ 3357 if (endp == path) { 3358 bname[0] = *endp == '/' ? '/' : '.'; 3359 bname[1] = '\0'; 3360 return (0); 3361 } else { 3362 do { 3363 endp--; 3364 } while (endp > path && *endp == '/'); 3365 } 3366 3367 if (endp - path + 2 > PATH_MAX) 3368 { 3369 _rtld_error("Filename is too long: %s", path); 3370 return(-1); 3371 } 3372 3373 strncpy(bname, path, endp - path + 1); 3374 bname[endp - path + 1] = '\0'; 3375 return (0); 3376 } 3377 3378 static int 3379 rtld_dirname_abs(const char *path, char *base) 3380 { 3381 char base_rel[PATH_MAX]; 3382 3383 if (rtld_dirname(path, base) == -1) 3384 return (-1); 3385 if (base[0] == '/') 3386 return (0); 3387 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3388 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3389 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3390 return (-1); 3391 strcpy(base, base_rel); 3392 return (0); 3393 } 3394 3395 static void 3396 linkmap_add(Obj_Entry *obj) 3397 { 3398 struct link_map *l = &obj->linkmap; 3399 struct link_map *prev; 3400 3401 obj->linkmap.l_name = obj->path; 3402 obj->linkmap.l_addr = obj->mapbase; 3403 obj->linkmap.l_ld = obj->dynamic; 3404 #ifdef __mips__ 3405 /* GDB needs load offset on MIPS to use the symbols */ 3406 obj->linkmap.l_offs = obj->relocbase; 3407 #endif 3408 3409 if (r_debug.r_map == NULL) { 3410 r_debug.r_map = l; 3411 return; 3412 } 3413 3414 /* 3415 * Scan to the end of the list, but not past the entry for the 3416 * dynamic linker, which we want to keep at the very end. 3417 */ 3418 for (prev = r_debug.r_map; 3419 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3420 prev = prev->l_next) 3421 ; 3422 3423 /* Link in the new entry. */ 3424 l->l_prev = prev; 3425 l->l_next = prev->l_next; 3426 if (l->l_next != NULL) 3427 l->l_next->l_prev = l; 3428 prev->l_next = l; 3429 } 3430 3431 static void 3432 linkmap_delete(Obj_Entry *obj) 3433 { 3434 struct link_map *l = &obj->linkmap; 3435 3436 if (l->l_prev == NULL) { 3437 if ((r_debug.r_map = l->l_next) != NULL) 3438 l->l_next->l_prev = NULL; 3439 return; 3440 } 3441 3442 if ((l->l_prev->l_next = l->l_next) != NULL) 3443 l->l_next->l_prev = l->l_prev; 3444 } 3445 3446 /* 3447 * Function for the debugger to set a breakpoint on to gain control. 3448 * 3449 * The two parameters allow the debugger to easily find and determine 3450 * what the runtime loader is doing and to whom it is doing it. 3451 * 3452 * When the loadhook trap is hit (r_debug_state, set at program 3453 * initialization), the arguments can be found on the stack: 3454 * 3455 * +8 struct link_map *m 3456 * +4 struct r_debug *rd 3457 * +0 RetAddr 3458 */ 3459 void 3460 r_debug_state(struct r_debug* rd, struct link_map *m) 3461 { 3462 /* 3463 * The following is a hack to force the compiler to emit calls to 3464 * this function, even when optimizing. If the function is empty, 3465 * the compiler is not obliged to emit any code for calls to it, 3466 * even when marked __noinline. However, gdb depends on those 3467 * calls being made. 3468 */ 3469 __asm __volatile("" : : : "memory"); 3470 } 3471 3472 /* 3473 * Get address of the pointer variable in the main program. 3474 * Prefer non-weak symbol over the weak one. 3475 */ 3476 static const void ** 3477 get_program_var_addr(const char *name, RtldLockState *lockstate) 3478 { 3479 SymLook req; 3480 DoneList donelist; 3481 3482 symlook_init(&req, name); 3483 req.lockstate = lockstate; 3484 donelist_init(&donelist); 3485 if (symlook_global(&req, &donelist) != 0) 3486 return (NULL); 3487 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3488 return ((const void **)make_function_pointer(req.sym_out, 3489 req.defobj_out)); 3490 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3491 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3492 else 3493 return ((const void **)(req.defobj_out->relocbase + 3494 req.sym_out->st_value)); 3495 } 3496 3497 /* 3498 * Set a pointer variable in the main program to the given value. This 3499 * is used to set key variables such as "environ" before any of the 3500 * init functions are called. 3501 */ 3502 static void 3503 set_program_var(const char *name, const void *value) 3504 { 3505 const void **addr; 3506 3507 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3508 dbg("\"%s\": *%p <-- %p", name, addr, value); 3509 *addr = value; 3510 } 3511 } 3512 3513 /* 3514 * Search the global objects, including dependencies and main object, 3515 * for the given symbol. 3516 */ 3517 static int 3518 symlook_global(SymLook *req, DoneList *donelist) 3519 { 3520 SymLook req1; 3521 const Objlist_Entry *elm; 3522 int res; 3523 3524 symlook_init_from_req(&req1, req); 3525 3526 /* Search all objects loaded at program start up. */ 3527 if (req->defobj_out == NULL || 3528 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3529 res = symlook_list(&req1, &list_main, donelist); 3530 if (res == 0 && (req->defobj_out == NULL || 3531 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3532 req->sym_out = req1.sym_out; 3533 req->defobj_out = req1.defobj_out; 3534 assert(req->defobj_out != NULL); 3535 } 3536 } 3537 3538 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3539 STAILQ_FOREACH(elm, &list_global, link) { 3540 if (req->defobj_out != NULL && 3541 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3542 break; 3543 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3544 if (res == 0 && (req->defobj_out == NULL || 3545 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3546 req->sym_out = req1.sym_out; 3547 req->defobj_out = req1.defobj_out; 3548 assert(req->defobj_out != NULL); 3549 } 3550 } 3551 3552 return (req->sym_out != NULL ? 0 : ESRCH); 3553 } 3554 3555 /* 3556 * Given a symbol name in a referencing object, find the corresponding 3557 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3558 * no definition was found. Returns a pointer to the Obj_Entry of the 3559 * defining object via the reference parameter DEFOBJ_OUT. 3560 */ 3561 static int 3562 symlook_default(SymLook *req, const Obj_Entry *refobj) 3563 { 3564 DoneList donelist; 3565 const Objlist_Entry *elm; 3566 SymLook req1; 3567 int res; 3568 3569 donelist_init(&donelist); 3570 symlook_init_from_req(&req1, req); 3571 3572 /* Look first in the referencing object if linked symbolically. */ 3573 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3574 res = symlook_obj(&req1, refobj); 3575 if (res == 0) { 3576 req->sym_out = req1.sym_out; 3577 req->defobj_out = req1.defobj_out; 3578 assert(req->defobj_out != NULL); 3579 } 3580 } 3581 3582 symlook_global(req, &donelist); 3583 3584 /* Search all dlopened DAGs containing the referencing object. */ 3585 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3586 if (req->sym_out != NULL && 3587 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3588 break; 3589 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3590 if (res == 0 && (req->sym_out == NULL || 3591 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3592 req->sym_out = req1.sym_out; 3593 req->defobj_out = req1.defobj_out; 3594 assert(req->defobj_out != NULL); 3595 } 3596 } 3597 3598 /* 3599 * Search the dynamic linker itself, and possibly resolve the 3600 * symbol from there. This is how the application links to 3601 * dynamic linker services such as dlopen. 3602 */ 3603 if (req->sym_out == NULL || 3604 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3605 res = symlook_obj(&req1, &obj_rtld); 3606 if (res == 0) { 3607 req->sym_out = req1.sym_out; 3608 req->defobj_out = req1.defobj_out; 3609 assert(req->defobj_out != NULL); 3610 } 3611 } 3612 3613 return (req->sym_out != NULL ? 0 : ESRCH); 3614 } 3615 3616 static int 3617 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3618 { 3619 const Elf_Sym *def; 3620 const Obj_Entry *defobj; 3621 const Objlist_Entry *elm; 3622 SymLook req1; 3623 int res; 3624 3625 def = NULL; 3626 defobj = NULL; 3627 STAILQ_FOREACH(elm, objlist, link) { 3628 if (donelist_check(dlp, elm->obj)) 3629 continue; 3630 symlook_init_from_req(&req1, req); 3631 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3632 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3633 def = req1.sym_out; 3634 defobj = req1.defobj_out; 3635 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3636 break; 3637 } 3638 } 3639 } 3640 if (def != NULL) { 3641 req->sym_out = def; 3642 req->defobj_out = defobj; 3643 return (0); 3644 } 3645 return (ESRCH); 3646 } 3647 3648 /* 3649 * Search the chain of DAGS cointed to by the given Needed_Entry 3650 * for a symbol of the given name. Each DAG is scanned completely 3651 * before advancing to the next one. Returns a pointer to the symbol, 3652 * or NULL if no definition was found. 3653 */ 3654 static int 3655 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3656 { 3657 const Elf_Sym *def; 3658 const Needed_Entry *n; 3659 const Obj_Entry *defobj; 3660 SymLook req1; 3661 int res; 3662 3663 def = NULL; 3664 defobj = NULL; 3665 symlook_init_from_req(&req1, req); 3666 for (n = needed; n != NULL; n = n->next) { 3667 if (n->obj == NULL || 3668 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3669 continue; 3670 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3671 def = req1.sym_out; 3672 defobj = req1.defobj_out; 3673 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3674 break; 3675 } 3676 } 3677 if (def != NULL) { 3678 req->sym_out = def; 3679 req->defobj_out = defobj; 3680 return (0); 3681 } 3682 return (ESRCH); 3683 } 3684 3685 /* 3686 * Search the symbol table of a single shared object for a symbol of 3687 * the given name and version, if requested. Returns a pointer to the 3688 * symbol, or NULL if no definition was found. If the object is 3689 * filter, return filtered symbol from filtee. 3690 * 3691 * The symbol's hash value is passed in for efficiency reasons; that 3692 * eliminates many recomputations of the hash value. 3693 */ 3694 int 3695 symlook_obj(SymLook *req, const Obj_Entry *obj) 3696 { 3697 DoneList donelist; 3698 SymLook req1; 3699 int flags, res, mres; 3700 3701 /* 3702 * If there is at least one valid hash at this point, we prefer to 3703 * use the faster GNU version if available. 3704 */ 3705 if (obj->valid_hash_gnu) 3706 mres = symlook_obj1_gnu(req, obj); 3707 else if (obj->valid_hash_sysv) 3708 mres = symlook_obj1_sysv(req, obj); 3709 else 3710 return (EINVAL); 3711 3712 if (mres == 0) { 3713 if (obj->needed_filtees != NULL) { 3714 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3715 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3716 donelist_init(&donelist); 3717 symlook_init_from_req(&req1, req); 3718 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3719 if (res == 0) { 3720 req->sym_out = req1.sym_out; 3721 req->defobj_out = req1.defobj_out; 3722 } 3723 return (res); 3724 } 3725 if (obj->needed_aux_filtees != NULL) { 3726 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3727 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3728 donelist_init(&donelist); 3729 symlook_init_from_req(&req1, req); 3730 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3731 if (res == 0) { 3732 req->sym_out = req1.sym_out; 3733 req->defobj_out = req1.defobj_out; 3734 return (res); 3735 } 3736 } 3737 } 3738 return (mres); 3739 } 3740 3741 /* Symbol match routine common to both hash functions */ 3742 static bool 3743 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3744 const unsigned long symnum) 3745 { 3746 Elf_Versym verndx; 3747 const Elf_Sym *symp; 3748 const char *strp; 3749 3750 symp = obj->symtab + symnum; 3751 strp = obj->strtab + symp->st_name; 3752 3753 switch (ELF_ST_TYPE(symp->st_info)) { 3754 case STT_FUNC: 3755 case STT_NOTYPE: 3756 case STT_OBJECT: 3757 case STT_COMMON: 3758 case STT_GNU_IFUNC: 3759 if (symp->st_value == 0) 3760 return (false); 3761 /* fallthrough */ 3762 case STT_TLS: 3763 if (symp->st_shndx != SHN_UNDEF) 3764 break; 3765 #ifndef __mips__ 3766 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3767 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3768 break; 3769 /* fallthrough */ 3770 #endif 3771 default: 3772 return (false); 3773 } 3774 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3775 return (false); 3776 3777 if (req->ventry == NULL) { 3778 if (obj->versyms != NULL) { 3779 verndx = VER_NDX(obj->versyms[symnum]); 3780 if (verndx > obj->vernum) { 3781 _rtld_error( 3782 "%s: symbol %s references wrong version %d", 3783 obj->path, obj->strtab + symnum, verndx); 3784 return (false); 3785 } 3786 /* 3787 * If we are not called from dlsym (i.e. this 3788 * is a normal relocation from unversioned 3789 * binary), accept the symbol immediately if 3790 * it happens to have first version after this 3791 * shared object became versioned. Otherwise, 3792 * if symbol is versioned and not hidden, 3793 * remember it. If it is the only symbol with 3794 * this name exported by the shared object, it 3795 * will be returned as a match by the calling 3796 * function. If symbol is global (verndx < 2) 3797 * accept it unconditionally. 3798 */ 3799 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3800 verndx == VER_NDX_GIVEN) { 3801 result->sym_out = symp; 3802 return (true); 3803 } 3804 else if (verndx >= VER_NDX_GIVEN) { 3805 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3806 == 0) { 3807 if (result->vsymp == NULL) 3808 result->vsymp = symp; 3809 result->vcount++; 3810 } 3811 return (false); 3812 } 3813 } 3814 result->sym_out = symp; 3815 return (true); 3816 } 3817 if (obj->versyms == NULL) { 3818 if (object_match_name(obj, req->ventry->name)) { 3819 _rtld_error("%s: object %s should provide version %s " 3820 "for symbol %s", obj_rtld.path, obj->path, 3821 req->ventry->name, obj->strtab + symnum); 3822 return (false); 3823 } 3824 } else { 3825 verndx = VER_NDX(obj->versyms[symnum]); 3826 if (verndx > obj->vernum) { 3827 _rtld_error("%s: symbol %s references wrong version %d", 3828 obj->path, obj->strtab + symnum, verndx); 3829 return (false); 3830 } 3831 if (obj->vertab[verndx].hash != req->ventry->hash || 3832 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3833 /* 3834 * Version does not match. Look if this is a 3835 * global symbol and if it is not hidden. If 3836 * global symbol (verndx < 2) is available, 3837 * use it. Do not return symbol if we are 3838 * called by dlvsym, because dlvsym looks for 3839 * a specific version and default one is not 3840 * what dlvsym wants. 3841 */ 3842 if ((req->flags & SYMLOOK_DLSYM) || 3843 (verndx >= VER_NDX_GIVEN) || 3844 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3845 return (false); 3846 } 3847 } 3848 result->sym_out = symp; 3849 return (true); 3850 } 3851 3852 /* 3853 * Search for symbol using SysV hash function. 3854 * obj->buckets is known not to be NULL at this point; the test for this was 3855 * performed with the obj->valid_hash_sysv assignment. 3856 */ 3857 static int 3858 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3859 { 3860 unsigned long symnum; 3861 Sym_Match_Result matchres; 3862 3863 matchres.sym_out = NULL; 3864 matchres.vsymp = NULL; 3865 matchres.vcount = 0; 3866 3867 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3868 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3869 if (symnum >= obj->nchains) 3870 return (ESRCH); /* Bad object */ 3871 3872 if (matched_symbol(req, obj, &matchres, symnum)) { 3873 req->sym_out = matchres.sym_out; 3874 req->defobj_out = obj; 3875 return (0); 3876 } 3877 } 3878 if (matchres.vcount == 1) { 3879 req->sym_out = matchres.vsymp; 3880 req->defobj_out = obj; 3881 return (0); 3882 } 3883 return (ESRCH); 3884 } 3885 3886 /* Search for symbol using GNU hash function */ 3887 static int 3888 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3889 { 3890 Elf_Addr bloom_word; 3891 const Elf32_Word *hashval; 3892 Elf32_Word bucket; 3893 Sym_Match_Result matchres; 3894 unsigned int h1, h2; 3895 unsigned long symnum; 3896 3897 matchres.sym_out = NULL; 3898 matchres.vsymp = NULL; 3899 matchres.vcount = 0; 3900 3901 /* Pick right bitmask word from Bloom filter array */ 3902 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3903 obj->maskwords_bm_gnu]; 3904 3905 /* Calculate modulus word size of gnu hash and its derivative */ 3906 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3907 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3908 3909 /* Filter out the "definitely not in set" queries */ 3910 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3911 return (ESRCH); 3912 3913 /* Locate hash chain and corresponding value element*/ 3914 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3915 if (bucket == 0) 3916 return (ESRCH); 3917 hashval = &obj->chain_zero_gnu[bucket]; 3918 do { 3919 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3920 symnum = hashval - obj->chain_zero_gnu; 3921 if (matched_symbol(req, obj, &matchres, symnum)) { 3922 req->sym_out = matchres.sym_out; 3923 req->defobj_out = obj; 3924 return (0); 3925 } 3926 } 3927 } while ((*hashval++ & 1) == 0); 3928 if (matchres.vcount == 1) { 3929 req->sym_out = matchres.vsymp; 3930 req->defobj_out = obj; 3931 return (0); 3932 } 3933 return (ESRCH); 3934 } 3935 3936 static void 3937 trace_loaded_objects(Obj_Entry *obj) 3938 { 3939 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3940 int c; 3941 3942 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3943 main_local = ""; 3944 3945 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3946 fmt1 = "\t%o => %p (%x)\n"; 3947 3948 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3949 fmt2 = "\t%o (%x)\n"; 3950 3951 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3952 3953 for (; obj; obj = obj->next) { 3954 Needed_Entry *needed; 3955 char *name, *path; 3956 bool is_lib; 3957 3958 if (list_containers && obj->needed != NULL) 3959 rtld_printf("%s:\n", obj->path); 3960 for (needed = obj->needed; needed; needed = needed->next) { 3961 if (needed->obj != NULL) { 3962 if (needed->obj->traced && !list_containers) 3963 continue; 3964 needed->obj->traced = true; 3965 path = needed->obj->path; 3966 } else 3967 path = "not found"; 3968 3969 name = (char *)obj->strtab + needed->name; 3970 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 3971 3972 fmt = is_lib ? fmt1 : fmt2; 3973 while ((c = *fmt++) != '\0') { 3974 switch (c) { 3975 default: 3976 rtld_putchar(c); 3977 continue; 3978 case '\\': 3979 switch (c = *fmt) { 3980 case '\0': 3981 continue; 3982 case 'n': 3983 rtld_putchar('\n'); 3984 break; 3985 case 't': 3986 rtld_putchar('\t'); 3987 break; 3988 } 3989 break; 3990 case '%': 3991 switch (c = *fmt) { 3992 case '\0': 3993 continue; 3994 case '%': 3995 default: 3996 rtld_putchar(c); 3997 break; 3998 case 'A': 3999 rtld_putstr(main_local); 4000 break; 4001 case 'a': 4002 rtld_putstr(obj_main->path); 4003 break; 4004 case 'o': 4005 rtld_putstr(name); 4006 break; 4007 #if 0 4008 case 'm': 4009 rtld_printf("%d", sodp->sod_major); 4010 break; 4011 case 'n': 4012 rtld_printf("%d", sodp->sod_minor); 4013 break; 4014 #endif 4015 case 'p': 4016 rtld_putstr(path); 4017 break; 4018 case 'x': 4019 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4020 0); 4021 break; 4022 } 4023 break; 4024 } 4025 ++fmt; 4026 } 4027 } 4028 } 4029 } 4030 4031 /* 4032 * Unload a dlopened object and its dependencies from memory and from 4033 * our data structures. It is assumed that the DAG rooted in the 4034 * object has already been unreferenced, and that the object has a 4035 * reference count of 0. 4036 */ 4037 static void 4038 unload_object(Obj_Entry *root) 4039 { 4040 Obj_Entry *obj; 4041 Obj_Entry **linkp; 4042 4043 assert(root->refcount == 0); 4044 4045 /* 4046 * Pass over the DAG removing unreferenced objects from 4047 * appropriate lists. 4048 */ 4049 unlink_object(root); 4050 4051 /* Unmap all objects that are no longer referenced. */ 4052 linkp = &obj_list->next; 4053 while ((obj = *linkp) != NULL) { 4054 if (obj->refcount == 0) { 4055 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4056 obj->path); 4057 dbg("unloading \"%s\"", obj->path); 4058 unload_filtees(root); 4059 munmap(obj->mapbase, obj->mapsize); 4060 linkmap_delete(obj); 4061 *linkp = obj->next; 4062 obj_count--; 4063 obj_free(obj); 4064 } else 4065 linkp = &obj->next; 4066 } 4067 obj_tail = linkp; 4068 } 4069 4070 static void 4071 unlink_object(Obj_Entry *root) 4072 { 4073 Objlist_Entry *elm; 4074 4075 if (root->refcount == 0) { 4076 /* Remove the object from the RTLD_GLOBAL list. */ 4077 objlist_remove(&list_global, root); 4078 4079 /* Remove the object from all objects' DAG lists. */ 4080 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4081 objlist_remove(&elm->obj->dldags, root); 4082 if (elm->obj != root) 4083 unlink_object(elm->obj); 4084 } 4085 } 4086 } 4087 4088 static void 4089 ref_dag(Obj_Entry *root) 4090 { 4091 Objlist_Entry *elm; 4092 4093 assert(root->dag_inited); 4094 STAILQ_FOREACH(elm, &root->dagmembers, link) 4095 elm->obj->refcount++; 4096 } 4097 4098 static void 4099 unref_dag(Obj_Entry *root) 4100 { 4101 Objlist_Entry *elm; 4102 4103 assert(root->dag_inited); 4104 STAILQ_FOREACH(elm, &root->dagmembers, link) 4105 elm->obj->refcount--; 4106 } 4107 4108 /* 4109 * Common code for MD __tls_get_addr(). 4110 */ 4111 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4112 static void * 4113 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4114 { 4115 Elf_Addr *newdtv, *dtv; 4116 RtldLockState lockstate; 4117 int to_copy; 4118 4119 dtv = *dtvp; 4120 /* Check dtv generation in case new modules have arrived */ 4121 if (dtv[0] != tls_dtv_generation) { 4122 wlock_acquire(rtld_bind_lock, &lockstate); 4123 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4124 to_copy = dtv[1]; 4125 if (to_copy > tls_max_index) 4126 to_copy = tls_max_index; 4127 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4128 newdtv[0] = tls_dtv_generation; 4129 newdtv[1] = tls_max_index; 4130 free(dtv); 4131 lock_release(rtld_bind_lock, &lockstate); 4132 dtv = *dtvp = newdtv; 4133 } 4134 4135 /* Dynamically allocate module TLS if necessary */ 4136 if (dtv[index + 1] == 0) { 4137 /* Signal safe, wlock will block out signals. */ 4138 wlock_acquire(rtld_bind_lock, &lockstate); 4139 if (!dtv[index + 1]) 4140 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4141 lock_release(rtld_bind_lock, &lockstate); 4142 } 4143 return ((void *)(dtv[index + 1] + offset)); 4144 } 4145 4146 void * 4147 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4148 { 4149 Elf_Addr *dtv; 4150 4151 dtv = *dtvp; 4152 /* Check dtv generation in case new modules have arrived */ 4153 if (__predict_true(dtv[0] == tls_dtv_generation && 4154 dtv[index + 1] != 0)) 4155 return ((void *)(dtv[index + 1] + offset)); 4156 return (tls_get_addr_slow(dtvp, index, offset)); 4157 } 4158 4159 #if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4160 4161 /* 4162 * Allocate Static TLS using the Variant I method. 4163 */ 4164 void * 4165 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4166 { 4167 Obj_Entry *obj; 4168 char *tcb; 4169 Elf_Addr **tls; 4170 Elf_Addr *dtv; 4171 Elf_Addr addr; 4172 int i; 4173 4174 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4175 return (oldtcb); 4176 4177 assert(tcbsize >= TLS_TCB_SIZE); 4178 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4179 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4180 4181 if (oldtcb != NULL) { 4182 memcpy(tls, oldtcb, tls_static_space); 4183 free(oldtcb); 4184 4185 /* Adjust the DTV. */ 4186 dtv = tls[0]; 4187 for (i = 0; i < dtv[1]; i++) { 4188 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4189 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4190 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4191 } 4192 } 4193 } else { 4194 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4195 tls[0] = dtv; 4196 dtv[0] = tls_dtv_generation; 4197 dtv[1] = tls_max_index; 4198 4199 for (obj = objs; obj; obj = obj->next) { 4200 if (obj->tlsoffset > 0) { 4201 addr = (Elf_Addr)tls + obj->tlsoffset; 4202 if (obj->tlsinitsize > 0) 4203 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4204 if (obj->tlssize > obj->tlsinitsize) 4205 memset((void*) (addr + obj->tlsinitsize), 0, 4206 obj->tlssize - obj->tlsinitsize); 4207 dtv[obj->tlsindex + 1] = addr; 4208 } 4209 } 4210 } 4211 4212 return (tcb); 4213 } 4214 4215 void 4216 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4217 { 4218 Elf_Addr *dtv; 4219 Elf_Addr tlsstart, tlsend; 4220 int dtvsize, i; 4221 4222 assert(tcbsize >= TLS_TCB_SIZE); 4223 4224 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4225 tlsend = tlsstart + tls_static_space; 4226 4227 dtv = *(Elf_Addr **)tlsstart; 4228 dtvsize = dtv[1]; 4229 for (i = 0; i < dtvsize; i++) { 4230 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4231 free((void*)dtv[i+2]); 4232 } 4233 } 4234 free(dtv); 4235 free(tcb); 4236 } 4237 4238 #endif 4239 4240 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4241 4242 /* 4243 * Allocate Static TLS using the Variant II method. 4244 */ 4245 void * 4246 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4247 { 4248 Obj_Entry *obj; 4249 size_t size; 4250 char *tls; 4251 Elf_Addr *dtv, *olddtv; 4252 Elf_Addr segbase, oldsegbase, addr; 4253 int i; 4254 4255 size = round(tls_static_space, tcbalign); 4256 4257 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4258 tls = xcalloc(1, size + tcbsize); 4259 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4260 4261 segbase = (Elf_Addr)(tls + size); 4262 ((Elf_Addr*)segbase)[0] = segbase; 4263 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4264 4265 dtv[0] = tls_dtv_generation; 4266 dtv[1] = tls_max_index; 4267 4268 if (oldtls) { 4269 /* 4270 * Copy the static TLS block over whole. 4271 */ 4272 oldsegbase = (Elf_Addr) oldtls; 4273 memcpy((void *)(segbase - tls_static_space), 4274 (const void *)(oldsegbase - tls_static_space), 4275 tls_static_space); 4276 4277 /* 4278 * If any dynamic TLS blocks have been created tls_get_addr(), 4279 * move them over. 4280 */ 4281 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4282 for (i = 0; i < olddtv[1]; i++) { 4283 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4284 dtv[i+2] = olddtv[i+2]; 4285 olddtv[i+2] = 0; 4286 } 4287 } 4288 4289 /* 4290 * We assume that this block was the one we created with 4291 * allocate_initial_tls(). 4292 */ 4293 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4294 } else { 4295 for (obj = objs; obj; obj = obj->next) { 4296 if (obj->tlsoffset) { 4297 addr = segbase - obj->tlsoffset; 4298 memset((void*) (addr + obj->tlsinitsize), 4299 0, obj->tlssize - obj->tlsinitsize); 4300 if (obj->tlsinit) 4301 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4302 dtv[obj->tlsindex + 1] = addr; 4303 } 4304 } 4305 } 4306 4307 return (void*) segbase; 4308 } 4309 4310 void 4311 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4312 { 4313 size_t size; 4314 Elf_Addr* dtv; 4315 int dtvsize, i; 4316 Elf_Addr tlsstart, tlsend; 4317 4318 /* 4319 * Figure out the size of the initial TLS block so that we can 4320 * find stuff which ___tls_get_addr() allocated dynamically. 4321 */ 4322 size = round(tls_static_space, tcbalign); 4323 4324 dtv = ((Elf_Addr**)tls)[1]; 4325 dtvsize = dtv[1]; 4326 tlsend = (Elf_Addr) tls; 4327 tlsstart = tlsend - size; 4328 for (i = 0; i < dtvsize; i++) { 4329 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 4330 free((void*) dtv[i+2]); 4331 } 4332 } 4333 4334 free((void*) tlsstart); 4335 free((void*) dtv); 4336 } 4337 4338 #endif 4339 4340 /* 4341 * Allocate TLS block for module with given index. 4342 */ 4343 void * 4344 allocate_module_tls(int index) 4345 { 4346 Obj_Entry* obj; 4347 char* p; 4348 4349 for (obj = obj_list; obj; obj = obj->next) { 4350 if (obj->tlsindex == index) 4351 break; 4352 } 4353 if (!obj) { 4354 _rtld_error("Can't find module with TLS index %d", index); 4355 die(); 4356 } 4357 4358 p = malloc(obj->tlssize); 4359 if (p == NULL) { 4360 _rtld_error("Cannot allocate TLS block for index %d", index); 4361 die(); 4362 } 4363 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4364 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4365 4366 return p; 4367 } 4368 4369 bool 4370 allocate_tls_offset(Obj_Entry *obj) 4371 { 4372 size_t off; 4373 4374 if (obj->tls_done) 4375 return true; 4376 4377 if (obj->tlssize == 0) { 4378 obj->tls_done = true; 4379 return true; 4380 } 4381 4382 if (obj->tlsindex == 1) 4383 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4384 else 4385 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4386 obj->tlssize, obj->tlsalign); 4387 4388 /* 4389 * If we have already fixed the size of the static TLS block, we 4390 * must stay within that size. When allocating the static TLS, we 4391 * leave a small amount of space spare to be used for dynamically 4392 * loading modules which use static TLS. 4393 */ 4394 if (tls_static_space) { 4395 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4396 return false; 4397 } 4398 4399 tls_last_offset = obj->tlsoffset = off; 4400 tls_last_size = obj->tlssize; 4401 obj->tls_done = true; 4402 4403 return true; 4404 } 4405 4406 void 4407 free_tls_offset(Obj_Entry *obj) 4408 { 4409 4410 /* 4411 * If we were the last thing to allocate out of the static TLS 4412 * block, we give our space back to the 'allocator'. This is a 4413 * simplistic workaround to allow libGL.so.1 to be loaded and 4414 * unloaded multiple times. 4415 */ 4416 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4417 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4418 tls_last_offset -= obj->tlssize; 4419 tls_last_size = 0; 4420 } 4421 } 4422 4423 void * 4424 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4425 { 4426 void *ret; 4427 RtldLockState lockstate; 4428 4429 wlock_acquire(rtld_bind_lock, &lockstate); 4430 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4431 lock_release(rtld_bind_lock, &lockstate); 4432 return (ret); 4433 } 4434 4435 void 4436 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4437 { 4438 RtldLockState lockstate; 4439 4440 wlock_acquire(rtld_bind_lock, &lockstate); 4441 free_tls(tcb, tcbsize, tcbalign); 4442 lock_release(rtld_bind_lock, &lockstate); 4443 } 4444 4445 static void 4446 object_add_name(Obj_Entry *obj, const char *name) 4447 { 4448 Name_Entry *entry; 4449 size_t len; 4450 4451 len = strlen(name); 4452 entry = malloc(sizeof(Name_Entry) + len); 4453 4454 if (entry != NULL) { 4455 strcpy(entry->name, name); 4456 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4457 } 4458 } 4459 4460 static int 4461 object_match_name(const Obj_Entry *obj, const char *name) 4462 { 4463 Name_Entry *entry; 4464 4465 STAILQ_FOREACH(entry, &obj->names, link) { 4466 if (strcmp(name, entry->name) == 0) 4467 return (1); 4468 } 4469 return (0); 4470 } 4471 4472 static Obj_Entry * 4473 locate_dependency(const Obj_Entry *obj, const char *name) 4474 { 4475 const Objlist_Entry *entry; 4476 const Needed_Entry *needed; 4477 4478 STAILQ_FOREACH(entry, &list_main, link) { 4479 if (object_match_name(entry->obj, name)) 4480 return entry->obj; 4481 } 4482 4483 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4484 if (strcmp(obj->strtab + needed->name, name) == 0 || 4485 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4486 /* 4487 * If there is DT_NEEDED for the name we are looking for, 4488 * we are all set. Note that object might not be found if 4489 * dependency was not loaded yet, so the function can 4490 * return NULL here. This is expected and handled 4491 * properly by the caller. 4492 */ 4493 return (needed->obj); 4494 } 4495 } 4496 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4497 obj->path, name); 4498 die(); 4499 } 4500 4501 static int 4502 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4503 const Elf_Vernaux *vna) 4504 { 4505 const Elf_Verdef *vd; 4506 const char *vername; 4507 4508 vername = refobj->strtab + vna->vna_name; 4509 vd = depobj->verdef; 4510 if (vd == NULL) { 4511 _rtld_error("%s: version %s required by %s not defined", 4512 depobj->path, vername, refobj->path); 4513 return (-1); 4514 } 4515 for (;;) { 4516 if (vd->vd_version != VER_DEF_CURRENT) { 4517 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4518 depobj->path, vd->vd_version); 4519 return (-1); 4520 } 4521 if (vna->vna_hash == vd->vd_hash) { 4522 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4523 ((char *)vd + vd->vd_aux); 4524 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4525 return (0); 4526 } 4527 if (vd->vd_next == 0) 4528 break; 4529 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4530 } 4531 if (vna->vna_flags & VER_FLG_WEAK) 4532 return (0); 4533 _rtld_error("%s: version %s required by %s not found", 4534 depobj->path, vername, refobj->path); 4535 return (-1); 4536 } 4537 4538 static int 4539 rtld_verify_object_versions(Obj_Entry *obj) 4540 { 4541 const Elf_Verneed *vn; 4542 const Elf_Verdef *vd; 4543 const Elf_Verdaux *vda; 4544 const Elf_Vernaux *vna; 4545 const Obj_Entry *depobj; 4546 int maxvernum, vernum; 4547 4548 if (obj->ver_checked) 4549 return (0); 4550 obj->ver_checked = true; 4551 4552 maxvernum = 0; 4553 /* 4554 * Walk over defined and required version records and figure out 4555 * max index used by any of them. Do very basic sanity checking 4556 * while there. 4557 */ 4558 vn = obj->verneed; 4559 while (vn != NULL) { 4560 if (vn->vn_version != VER_NEED_CURRENT) { 4561 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4562 obj->path, vn->vn_version); 4563 return (-1); 4564 } 4565 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4566 for (;;) { 4567 vernum = VER_NEED_IDX(vna->vna_other); 4568 if (vernum > maxvernum) 4569 maxvernum = vernum; 4570 if (vna->vna_next == 0) 4571 break; 4572 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4573 } 4574 if (vn->vn_next == 0) 4575 break; 4576 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4577 } 4578 4579 vd = obj->verdef; 4580 while (vd != NULL) { 4581 if (vd->vd_version != VER_DEF_CURRENT) { 4582 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4583 obj->path, vd->vd_version); 4584 return (-1); 4585 } 4586 vernum = VER_DEF_IDX(vd->vd_ndx); 4587 if (vernum > maxvernum) 4588 maxvernum = vernum; 4589 if (vd->vd_next == 0) 4590 break; 4591 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4592 } 4593 4594 if (maxvernum == 0) 4595 return (0); 4596 4597 /* 4598 * Store version information in array indexable by version index. 4599 * Verify that object version requirements are satisfied along the 4600 * way. 4601 */ 4602 obj->vernum = maxvernum + 1; 4603 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4604 4605 vd = obj->verdef; 4606 while (vd != NULL) { 4607 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4608 vernum = VER_DEF_IDX(vd->vd_ndx); 4609 assert(vernum <= maxvernum); 4610 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4611 obj->vertab[vernum].hash = vd->vd_hash; 4612 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4613 obj->vertab[vernum].file = NULL; 4614 obj->vertab[vernum].flags = 0; 4615 } 4616 if (vd->vd_next == 0) 4617 break; 4618 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4619 } 4620 4621 vn = obj->verneed; 4622 while (vn != NULL) { 4623 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4624 if (depobj == NULL) 4625 return (-1); 4626 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4627 for (;;) { 4628 if (check_object_provided_version(obj, depobj, vna)) 4629 return (-1); 4630 vernum = VER_NEED_IDX(vna->vna_other); 4631 assert(vernum <= maxvernum); 4632 obj->vertab[vernum].hash = vna->vna_hash; 4633 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4634 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4635 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4636 VER_INFO_HIDDEN : 0; 4637 if (vna->vna_next == 0) 4638 break; 4639 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4640 } 4641 if (vn->vn_next == 0) 4642 break; 4643 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4644 } 4645 return 0; 4646 } 4647 4648 static int 4649 rtld_verify_versions(const Objlist *objlist) 4650 { 4651 Objlist_Entry *entry; 4652 int rc; 4653 4654 rc = 0; 4655 STAILQ_FOREACH(entry, objlist, link) { 4656 /* 4657 * Skip dummy objects or objects that have their version requirements 4658 * already checked. 4659 */ 4660 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4661 continue; 4662 if (rtld_verify_object_versions(entry->obj) == -1) { 4663 rc = -1; 4664 if (ld_tracing == NULL) 4665 break; 4666 } 4667 } 4668 if (rc == 0 || ld_tracing != NULL) 4669 rc = rtld_verify_object_versions(&obj_rtld); 4670 return rc; 4671 } 4672 4673 const Ver_Entry * 4674 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4675 { 4676 Elf_Versym vernum; 4677 4678 if (obj->vertab) { 4679 vernum = VER_NDX(obj->versyms[symnum]); 4680 if (vernum >= obj->vernum) { 4681 _rtld_error("%s: symbol %s has wrong verneed value %d", 4682 obj->path, obj->strtab + symnum, vernum); 4683 } else if (obj->vertab[vernum].hash != 0) { 4684 return &obj->vertab[vernum]; 4685 } 4686 } 4687 return NULL; 4688 } 4689 4690 int 4691 _rtld_get_stack_prot(void) 4692 { 4693 4694 return (stack_prot); 4695 } 4696 4697 static void 4698 map_stacks_exec(RtldLockState *lockstate) 4699 { 4700 void (*thr_map_stacks_exec)(void); 4701 4702 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4703 return; 4704 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4705 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4706 if (thr_map_stacks_exec != NULL) { 4707 stack_prot |= PROT_EXEC; 4708 thr_map_stacks_exec(); 4709 } 4710 } 4711 4712 void 4713 symlook_init(SymLook *dst, const char *name) 4714 { 4715 4716 bzero(dst, sizeof(*dst)); 4717 dst->name = name; 4718 dst->hash = elf_hash(name); 4719 dst->hash_gnu = gnu_hash(name); 4720 } 4721 4722 static void 4723 symlook_init_from_req(SymLook *dst, const SymLook *src) 4724 { 4725 4726 dst->name = src->name; 4727 dst->hash = src->hash; 4728 dst->hash_gnu = src->hash_gnu; 4729 dst->ventry = src->ventry; 4730 dst->flags = src->flags; 4731 dst->defobj_out = NULL; 4732 dst->sym_out = NULL; 4733 dst->lockstate = src->lockstate; 4734 } 4735 4736 /* 4737 * Overrides for libc_pic-provided functions. 4738 */ 4739 4740 int 4741 __getosreldate(void) 4742 { 4743 size_t len; 4744 int oid[2]; 4745 int error, osrel; 4746 4747 if (osreldate != 0) 4748 return (osreldate); 4749 4750 oid[0] = CTL_KERN; 4751 oid[1] = KERN_OSRELDATE; 4752 osrel = 0; 4753 len = sizeof(osrel); 4754 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4755 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4756 osreldate = osrel; 4757 return (osreldate); 4758 } 4759 4760 void 4761 exit(int status) 4762 { 4763 4764 _exit(status); 4765 } 4766 4767 void (*__cleanup)(void); 4768 int __isthreaded = 0; 4769 int _thread_autoinit_dummy_decl = 1; 4770 4771 /* 4772 * No unresolved symbols for rtld. 4773 */ 4774 void 4775 __pthread_cxa_finalize(struct dl_phdr_info *a) 4776 { 4777 } 4778 4779 void 4780 __stack_chk_fail(void) 4781 { 4782 4783 _rtld_error("stack overflow detected; terminated"); 4784 die(); 4785 } 4786 __weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4787 4788 void 4789 __chk_fail(void) 4790 { 4791 4792 _rtld_error("buffer overflow detected; terminated"); 4793 die(); 4794 } 4795 4796 const char * 4797 rtld_strerror(int errnum) 4798 { 4799 4800 if (errnum < 0 || errnum >= sys_nerr) 4801 return ("Unknown error"); 4802 return (sys_errlist[errnum]); 4803 } 4804