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