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_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 120 static void objlist_remove(Objlist *, Obj_Entry *); 121 static void *path_enumerate(const char *, path_enum_proc, void *); 122 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 123 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 124 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 125 int flags, RtldLockState *lockstate); 126 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 127 RtldLockState *); 128 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 129 int flags, RtldLockState *lockstate); 130 static int rtld_dirname(const char *, char *); 131 static int rtld_dirname_abs(const char *, char *); 132 static void *rtld_dlopen(const char *name, int fd, int mode); 133 static void rtld_exit(void); 134 static char *search_library_path(const char *, const char *); 135 static const void **get_program_var_addr(const char *, RtldLockState *); 136 static void set_program_var(const char *, const void *); 137 static int symlook_default(SymLook *, const Obj_Entry *refobj); 138 static int symlook_global(SymLook *, DoneList *); 139 static void symlook_init_from_req(SymLook *, const SymLook *); 140 static int symlook_list(SymLook *, const Objlist *, DoneList *); 141 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 142 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 143 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 144 static void trace_loaded_objects(Obj_Entry *); 145 static void unlink_object(Obj_Entry *); 146 static void unload_object(Obj_Entry *); 147 static void unref_dag(Obj_Entry *); 148 static void ref_dag(Obj_Entry *); 149 static char *origin_subst_one(char *, const char *, const char *, bool); 150 static char *origin_subst(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 Obj_Entry *last_interposer; 328 Objlist initlist; 329 RtldLockState lockstate; 330 char *library_path_rpath; 331 int mib[2]; 332 size_t len; 333 334 /* 335 * On entry, the dynamic linker itself has not been relocated yet. 336 * Be very careful not to reference any global data until after 337 * init_rtld has returned. It is OK to reference file-scope statics 338 * and string constants, and to call static and global functions. 339 */ 340 341 /* Find the auxiliary vector on the stack. */ 342 argc = *sp++; 343 argv = (char **) sp; 344 sp += argc + 1; /* Skip over arguments and NULL terminator */ 345 env = (char **) sp; 346 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 347 ; 348 aux = (Elf_Auxinfo *) sp; 349 350 /* Digest the auxiliary vector. */ 351 for (i = 0; i < AT_COUNT; i++) 352 aux_info[i] = NULL; 353 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 354 if (auxp->a_type < AT_COUNT) 355 aux_info[auxp->a_type] = auxp; 356 } 357 358 /* Initialize and relocate ourselves. */ 359 assert(aux_info[AT_BASE] != NULL); 360 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 361 362 __progname = obj_rtld.path; 363 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 364 environ = env; 365 main_argc = argc; 366 main_argv = argv; 367 368 if (aux_info[AT_CANARY] != NULL && 369 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 370 i = aux_info[AT_CANARYLEN]->a_un.a_val; 371 if (i > sizeof(__stack_chk_guard)) 372 i = sizeof(__stack_chk_guard); 373 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 374 } else { 375 mib[0] = CTL_KERN; 376 mib[1] = KERN_ARND; 377 378 len = sizeof(__stack_chk_guard); 379 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 380 len != sizeof(__stack_chk_guard)) { 381 /* If sysctl was unsuccessful, use the "terminator canary". */ 382 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 383 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 384 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 385 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 386 } 387 } 388 389 trust = !issetugid(); 390 391 ld_bind_now = getenv(LD_ "BIND_NOW"); 392 /* 393 * If the process is tainted, then we un-set the dangerous environment 394 * variables. The process will be marked as tainted until setuid(2) 395 * is called. If any child process calls setuid(2) we do not want any 396 * future processes to honor the potentially un-safe variables. 397 */ 398 if (!trust) { 399 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 400 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 401 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 402 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 403 _rtld_error("environment corrupt; aborting"); 404 die(); 405 } 406 } 407 ld_debug = getenv(LD_ "DEBUG"); 408 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 409 libmap_override = getenv(LD_ "LIBMAP"); 410 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 411 ld_preload = getenv(LD_ "PRELOAD"); 412 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 413 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 414 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 415 if (library_path_rpath != NULL) { 416 if (library_path_rpath[0] == 'y' || 417 library_path_rpath[0] == 'Y' || 418 library_path_rpath[0] == '1') 419 ld_library_path_rpath = true; 420 else 421 ld_library_path_rpath = false; 422 } 423 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 424 (ld_library_path != NULL) || (ld_preload != NULL) || 425 (ld_elf_hints_path != NULL) || ld_loadfltr; 426 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 427 ld_utrace = getenv(LD_ "UTRACE"); 428 429 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 430 ld_elf_hints_path = _PATH_ELF_HINTS; 431 432 if (ld_debug != NULL && *ld_debug != '\0') 433 debug = 1; 434 dbg("%s is initialized, base address = %p", __progname, 435 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 436 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 437 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 438 439 dbg("initializing thread locks"); 440 lockdflt_init(); 441 442 /* 443 * Load the main program, or process its program header if it is 444 * already loaded. 445 */ 446 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 447 int fd = aux_info[AT_EXECFD]->a_un.a_val; 448 dbg("loading main program"); 449 obj_main = map_object(fd, argv0, NULL); 450 close(fd); 451 if (obj_main == NULL) 452 die(); 453 max_stack_flags = obj->stack_flags; 454 } else { /* Main program already loaded. */ 455 const Elf_Phdr *phdr; 456 int phnum; 457 caddr_t entry; 458 459 dbg("processing main program's program header"); 460 assert(aux_info[AT_PHDR] != NULL); 461 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 462 assert(aux_info[AT_PHNUM] != NULL); 463 phnum = aux_info[AT_PHNUM]->a_un.a_val; 464 assert(aux_info[AT_PHENT] != NULL); 465 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 466 assert(aux_info[AT_ENTRY] != NULL); 467 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 468 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 469 die(); 470 } 471 472 if (aux_info[AT_EXECPATH] != 0) { 473 char *kexecpath; 474 char buf[MAXPATHLEN]; 475 476 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 477 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 478 if (kexecpath[0] == '/') 479 obj_main->path = kexecpath; 480 else if (getcwd(buf, sizeof(buf)) == NULL || 481 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 482 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 483 obj_main->path = xstrdup(argv0); 484 else 485 obj_main->path = xstrdup(buf); 486 } else { 487 dbg("No AT_EXECPATH"); 488 obj_main->path = xstrdup(argv0); 489 } 490 dbg("obj_main path %s", obj_main->path); 491 obj_main->mainprog = true; 492 493 if (aux_info[AT_STACKPROT] != NULL && 494 aux_info[AT_STACKPROT]->a_un.a_val != 0) 495 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 496 497 /* 498 * Get the actual dynamic linker pathname from the executable if 499 * possible. (It should always be possible.) That ensures that 500 * gdb will find the right dynamic linker even if a non-standard 501 * one is being used. 502 */ 503 if (obj_main->interp != NULL && 504 strcmp(obj_main->interp, obj_rtld.path) != 0) { 505 free(obj_rtld.path); 506 obj_rtld.path = xstrdup(obj_main->interp); 507 __progname = obj_rtld.path; 508 } 509 510 digest_dynamic(obj_main, 0); 511 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 512 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 513 obj_main->dynsymcount); 514 515 linkmap_add(obj_main); 516 linkmap_add(&obj_rtld); 517 518 /* Link the main program into the list of objects. */ 519 *obj_tail = obj_main; 520 obj_tail = &obj_main->next; 521 obj_count++; 522 obj_loads++; 523 524 /* Initialize a fake symbol for resolving undefined weak references. */ 525 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 526 sym_zero.st_shndx = SHN_UNDEF; 527 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 528 529 if (!libmap_disable) 530 libmap_disable = (bool)lm_init(libmap_override); 531 532 dbg("loading LD_PRELOAD libraries"); 533 if (load_preload_objects() == -1) 534 die(); 535 preload_tail = obj_tail; 536 537 dbg("loading needed objects"); 538 if (load_needed_objects(obj_main, 0) == -1) 539 die(); 540 541 /* Make a list of all objects loaded at startup. */ 542 last_interposer = obj_main; 543 for (obj = obj_list; obj != NULL; obj = obj->next) { 544 if (obj->z_interpose && obj != obj_main) { 545 objlist_put_after(&list_main, last_interposer, obj); 546 last_interposer = obj; 547 } else { 548 objlist_push_tail(&list_main, obj); 549 } 550 obj->refcount++; 551 } 552 553 dbg("checking for required versions"); 554 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 555 die(); 556 557 if (ld_tracing) { /* We're done */ 558 trace_loaded_objects(obj_main); 559 exit(0); 560 } 561 562 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 563 dump_relocations(obj_main); 564 exit (0); 565 } 566 567 /* 568 * Processing tls relocations requires having the tls offsets 569 * initialized. Prepare offsets before starting initial 570 * relocation processing. 571 */ 572 dbg("initializing initial thread local storage offsets"); 573 STAILQ_FOREACH(entry, &list_main, link) { 574 /* 575 * Allocate all the initial objects out of the static TLS 576 * block even if they didn't ask for it. 577 */ 578 allocate_tls_offset(entry->obj); 579 } 580 581 if (relocate_objects(obj_main, 582 ld_bind_now != NULL && *ld_bind_now != '\0', 583 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 584 die(); 585 586 dbg("doing copy relocations"); 587 if (do_copy_relocations(obj_main) == -1) 588 die(); 589 590 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 591 dump_relocations(obj_main); 592 exit (0); 593 } 594 595 /* 596 * Setup TLS for main thread. This must be done after the 597 * relocations are processed, since tls initialization section 598 * might be the subject for relocations. 599 */ 600 dbg("initializing initial thread local storage"); 601 allocate_initial_tls(obj_list); 602 603 dbg("initializing key program variables"); 604 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 605 set_program_var("environ", env); 606 set_program_var("__elf_aux_vector", aux); 607 608 /* Make a list of init functions to call. */ 609 objlist_init(&initlist); 610 initlist_add_objects(obj_list, preload_tail, &initlist); 611 612 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 613 614 map_stacks_exec(NULL); 615 616 dbg("resolving ifuncs"); 617 if (resolve_objects_ifunc(obj_main, 618 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 619 NULL) == -1) 620 die(); 621 622 if (!obj_main->crt_no_init) { 623 /* 624 * Make sure we don't call the main program's init and fini 625 * functions for binaries linked with old crt1 which calls 626 * _init itself. 627 */ 628 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 629 obj_main->preinit_array = obj_main->init_array = 630 obj_main->fini_array = (Elf_Addr)NULL; 631 } 632 633 wlock_acquire(rtld_bind_lock, &lockstate); 634 if (obj_main->crt_no_init) 635 preinit_main(); 636 objlist_call_init(&initlist, &lockstate); 637 objlist_clear(&initlist); 638 dbg("loading filtees"); 639 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 640 if (ld_loadfltr || obj->z_loadfltr) 641 load_filtees(obj, 0, &lockstate); 642 } 643 lock_release(rtld_bind_lock, &lockstate); 644 645 dbg("transferring control to program entry point = %p", obj_main->entry); 646 647 /* Return the exit procedure and the program entry point. */ 648 *exit_proc = rtld_exit; 649 *objp = obj_main; 650 return (func_ptr_type) obj_main->entry; 651 } 652 653 void * 654 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 655 { 656 void *ptr; 657 Elf_Addr target; 658 659 ptr = (void *)make_function_pointer(def, obj); 660 target = ((Elf_Addr (*)(void))ptr)(); 661 return ((void *)target); 662 } 663 664 Elf_Addr 665 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 666 { 667 const Elf_Rel *rel; 668 const Elf_Sym *def; 669 const Obj_Entry *defobj; 670 Elf_Addr *where; 671 Elf_Addr target; 672 RtldLockState lockstate; 673 674 rlock_acquire(rtld_bind_lock, &lockstate); 675 if (sigsetjmp(lockstate.env, 0) != 0) 676 lock_upgrade(rtld_bind_lock, &lockstate); 677 if (obj->pltrel) 678 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 679 else 680 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 681 682 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 683 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 684 &lockstate); 685 if (def == NULL) 686 die(); 687 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 688 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 689 else 690 target = (Elf_Addr)(defobj->relocbase + def->st_value); 691 692 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 693 defobj->strtab + def->st_name, basename(obj->path), 694 (void *)target, basename(defobj->path)); 695 696 /* 697 * Write the new contents for the jmpslot. Note that depending on 698 * architecture, the value which we need to return back to the 699 * lazy binding trampoline may or may not be the target 700 * address. The value returned from reloc_jmpslot() is the value 701 * that the trampoline needs. 702 */ 703 target = reloc_jmpslot(where, target, defobj, obj, rel); 704 lock_release(rtld_bind_lock, &lockstate); 705 return target; 706 } 707 708 /* 709 * Error reporting function. Use it like printf. If formats the message 710 * into a buffer, and sets things up so that the next call to dlerror() 711 * will return the message. 712 */ 713 void 714 _rtld_error(const char *fmt, ...) 715 { 716 static char buf[512]; 717 va_list ap; 718 719 va_start(ap, fmt); 720 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 721 error_message = buf; 722 va_end(ap); 723 } 724 725 /* 726 * Return a dynamically-allocated copy of the current error message, if any. 727 */ 728 static char * 729 errmsg_save(void) 730 { 731 return error_message == NULL ? NULL : xstrdup(error_message); 732 } 733 734 /* 735 * Restore the current error message from a copy which was previously saved 736 * by errmsg_save(). The copy is freed. 737 */ 738 static void 739 errmsg_restore(char *saved_msg) 740 { 741 if (saved_msg == NULL) 742 error_message = NULL; 743 else { 744 _rtld_error("%s", saved_msg); 745 free(saved_msg); 746 } 747 } 748 749 static const char * 750 basename(const char *name) 751 { 752 const char *p = strrchr(name, '/'); 753 return p != NULL ? p + 1 : name; 754 } 755 756 static struct utsname uts; 757 758 static char * 759 origin_subst_one(char *real, const char *kw, const char *subst, 760 bool may_free) 761 { 762 char *p, *p1, *res, *resp; 763 int subst_len, kw_len, subst_count, old_len, new_len; 764 765 kw_len = strlen(kw); 766 767 /* 768 * First, count the number of the keyword occurences, to 769 * preallocate the final string. 770 */ 771 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 772 p1 = strstr(p, kw); 773 if (p1 == NULL) 774 break; 775 } 776 777 /* 778 * If the keyword is not found, just return. 779 */ 780 if (subst_count == 0) 781 return (may_free ? real : xstrdup(real)); 782 783 /* 784 * There is indeed something to substitute. Calculate the 785 * length of the resulting string, and allocate it. 786 */ 787 subst_len = strlen(subst); 788 old_len = strlen(real); 789 new_len = old_len + (subst_len - kw_len) * subst_count; 790 res = xmalloc(new_len + 1); 791 792 /* 793 * Now, execute the substitution loop. 794 */ 795 for (p = real, resp = res, *resp = '\0';;) { 796 p1 = strstr(p, kw); 797 if (p1 != NULL) { 798 /* Copy the prefix before keyword. */ 799 memcpy(resp, p, p1 - p); 800 resp += p1 - p; 801 /* Keyword replacement. */ 802 memcpy(resp, subst, subst_len); 803 resp += subst_len; 804 *resp = '\0'; 805 p = p1 + kw_len; 806 } else 807 break; 808 } 809 810 /* Copy to the end of string and finish. */ 811 strcat(resp, p); 812 if (may_free) 813 free(real); 814 return (res); 815 } 816 817 static char * 818 origin_subst(char *real, const char *origin_path) 819 { 820 char *res1, *res2, *res3, *res4; 821 822 if (uts.sysname[0] == '\0') { 823 if (uname(&uts) != 0) { 824 _rtld_error("utsname failed: %d", errno); 825 return (NULL); 826 } 827 } 828 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 829 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 830 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 831 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 832 return (res4); 833 } 834 835 static void 836 die(void) 837 { 838 const char *msg = dlerror(); 839 840 if (msg == NULL) 841 msg = "Fatal error"; 842 rtld_fdputstr(STDERR_FILENO, msg); 843 rtld_fdputchar(STDERR_FILENO, '\n'); 844 _exit(1); 845 } 846 847 /* 848 * Process a shared object's DYNAMIC section, and save the important 849 * information in its Obj_Entry structure. 850 */ 851 static void 852 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 853 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 854 { 855 const Elf_Dyn *dynp; 856 Needed_Entry **needed_tail = &obj->needed; 857 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 858 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 859 const Elf_Hashelt *hashtab; 860 const Elf32_Word *hashval; 861 Elf32_Word bkt, nmaskwords; 862 int bloom_size32; 863 bool nmw_power2; 864 int plttype = DT_REL; 865 866 *dyn_rpath = NULL; 867 *dyn_soname = NULL; 868 *dyn_runpath = NULL; 869 870 obj->bind_now = false; 871 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 872 switch (dynp->d_tag) { 873 874 case DT_REL: 875 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 876 break; 877 878 case DT_RELSZ: 879 obj->relsize = dynp->d_un.d_val; 880 break; 881 882 case DT_RELENT: 883 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 884 break; 885 886 case DT_JMPREL: 887 obj->pltrel = (const Elf_Rel *) 888 (obj->relocbase + dynp->d_un.d_ptr); 889 break; 890 891 case DT_PLTRELSZ: 892 obj->pltrelsize = dynp->d_un.d_val; 893 break; 894 895 case DT_RELA: 896 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 897 break; 898 899 case DT_RELASZ: 900 obj->relasize = dynp->d_un.d_val; 901 break; 902 903 case DT_RELAENT: 904 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 905 break; 906 907 case DT_PLTREL: 908 plttype = dynp->d_un.d_val; 909 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 910 break; 911 912 case DT_SYMTAB: 913 obj->symtab = (const Elf_Sym *) 914 (obj->relocbase + dynp->d_un.d_ptr); 915 break; 916 917 case DT_SYMENT: 918 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 919 break; 920 921 case DT_STRTAB: 922 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 923 break; 924 925 case DT_STRSZ: 926 obj->strsize = dynp->d_un.d_val; 927 break; 928 929 case DT_VERNEED: 930 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 931 dynp->d_un.d_val); 932 break; 933 934 case DT_VERNEEDNUM: 935 obj->verneednum = dynp->d_un.d_val; 936 break; 937 938 case DT_VERDEF: 939 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 940 dynp->d_un.d_val); 941 break; 942 943 case DT_VERDEFNUM: 944 obj->verdefnum = dynp->d_un.d_val; 945 break; 946 947 case DT_VERSYM: 948 obj->versyms = (const Elf_Versym *)(obj->relocbase + 949 dynp->d_un.d_val); 950 break; 951 952 case DT_HASH: 953 { 954 hashtab = (const Elf_Hashelt *)(obj->relocbase + 955 dynp->d_un.d_ptr); 956 obj->nbuckets = hashtab[0]; 957 obj->nchains = hashtab[1]; 958 obj->buckets = hashtab + 2; 959 obj->chains = obj->buckets + obj->nbuckets; 960 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 961 obj->buckets != NULL; 962 } 963 break; 964 965 case DT_GNU_HASH: 966 { 967 hashtab = (const Elf_Hashelt *)(obj->relocbase + 968 dynp->d_un.d_ptr); 969 obj->nbuckets_gnu = hashtab[0]; 970 obj->symndx_gnu = hashtab[1]; 971 nmaskwords = hashtab[2]; 972 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 973 /* Number of bitmask words is required to be power of 2 */ 974 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 975 obj->maskwords_bm_gnu = nmaskwords - 1; 976 obj->shift2_gnu = hashtab[3]; 977 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 978 obj->buckets_gnu = hashtab + 4 + bloom_size32; 979 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 980 obj->symndx_gnu; 981 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 982 obj->buckets_gnu != NULL; 983 } 984 break; 985 986 case DT_NEEDED: 987 if (!obj->rtld) { 988 Needed_Entry *nep = NEW(Needed_Entry); 989 nep->name = dynp->d_un.d_val; 990 nep->obj = NULL; 991 nep->next = NULL; 992 993 *needed_tail = nep; 994 needed_tail = &nep->next; 995 } 996 break; 997 998 case DT_FILTER: 999 if (!obj->rtld) { 1000 Needed_Entry *nep = NEW(Needed_Entry); 1001 nep->name = dynp->d_un.d_val; 1002 nep->obj = NULL; 1003 nep->next = NULL; 1004 1005 *needed_filtees_tail = nep; 1006 needed_filtees_tail = &nep->next; 1007 } 1008 break; 1009 1010 case DT_AUXILIARY: 1011 if (!obj->rtld) { 1012 Needed_Entry *nep = NEW(Needed_Entry); 1013 nep->name = dynp->d_un.d_val; 1014 nep->obj = NULL; 1015 nep->next = NULL; 1016 1017 *needed_aux_filtees_tail = nep; 1018 needed_aux_filtees_tail = &nep->next; 1019 } 1020 break; 1021 1022 case DT_PLTGOT: 1023 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1024 break; 1025 1026 case DT_TEXTREL: 1027 obj->textrel = true; 1028 break; 1029 1030 case DT_SYMBOLIC: 1031 obj->symbolic = true; 1032 break; 1033 1034 case DT_RPATH: 1035 /* 1036 * We have to wait until later to process this, because we 1037 * might not have gotten the address of the string table yet. 1038 */ 1039 *dyn_rpath = dynp; 1040 break; 1041 1042 case DT_SONAME: 1043 *dyn_soname = dynp; 1044 break; 1045 1046 case DT_RUNPATH: 1047 *dyn_runpath = dynp; 1048 break; 1049 1050 case DT_INIT: 1051 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1052 break; 1053 1054 case DT_PREINIT_ARRAY: 1055 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1056 break; 1057 1058 case DT_PREINIT_ARRAYSZ: 1059 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1060 break; 1061 1062 case DT_INIT_ARRAY: 1063 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1064 break; 1065 1066 case DT_INIT_ARRAYSZ: 1067 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1068 break; 1069 1070 case DT_FINI: 1071 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1072 break; 1073 1074 case DT_FINI_ARRAY: 1075 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1076 break; 1077 1078 case DT_FINI_ARRAYSZ: 1079 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1080 break; 1081 1082 /* 1083 * Don't process DT_DEBUG on MIPS as the dynamic section 1084 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1085 */ 1086 1087 #ifndef __mips__ 1088 case DT_DEBUG: 1089 /* XXX - not implemented yet */ 1090 if (!early) 1091 dbg("Filling in DT_DEBUG entry"); 1092 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1093 break; 1094 #endif 1095 1096 case DT_FLAGS: 1097 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1098 obj->z_origin = true; 1099 if (dynp->d_un.d_val & DF_SYMBOLIC) 1100 obj->symbolic = true; 1101 if (dynp->d_un.d_val & DF_TEXTREL) 1102 obj->textrel = true; 1103 if (dynp->d_un.d_val & DF_BIND_NOW) 1104 obj->bind_now = true; 1105 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1106 ;*/ 1107 break; 1108 #ifdef __mips__ 1109 case DT_MIPS_LOCAL_GOTNO: 1110 obj->local_gotno = dynp->d_un.d_val; 1111 break; 1112 1113 case DT_MIPS_SYMTABNO: 1114 obj->symtabno = dynp->d_un.d_val; 1115 break; 1116 1117 case DT_MIPS_GOTSYM: 1118 obj->gotsym = dynp->d_un.d_val; 1119 break; 1120 1121 case DT_MIPS_RLD_MAP: 1122 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1123 break; 1124 #endif 1125 1126 case DT_FLAGS_1: 1127 if (dynp->d_un.d_val & DF_1_NOOPEN) 1128 obj->z_noopen = true; 1129 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1130 obj->z_origin = true; 1131 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1132 XXX ;*/ 1133 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1134 obj->bind_now = true; 1135 if (dynp->d_un.d_val & DF_1_NODELETE) 1136 obj->z_nodelete = true; 1137 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1138 obj->z_loadfltr = true; 1139 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1140 obj->z_interpose = true; 1141 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1142 obj->z_nodeflib = true; 1143 break; 1144 1145 default: 1146 if (!early) { 1147 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1148 (long)dynp->d_tag); 1149 } 1150 break; 1151 } 1152 } 1153 1154 obj->traced = false; 1155 1156 if (plttype == DT_RELA) { 1157 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1158 obj->pltrel = NULL; 1159 obj->pltrelasize = obj->pltrelsize; 1160 obj->pltrelsize = 0; 1161 } 1162 1163 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1164 if (obj->valid_hash_sysv) 1165 obj->dynsymcount = obj->nchains; 1166 else if (obj->valid_hash_gnu) { 1167 obj->dynsymcount = 0; 1168 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1169 if (obj->buckets_gnu[bkt] == 0) 1170 continue; 1171 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1172 do 1173 obj->dynsymcount++; 1174 while ((*hashval++ & 1u) == 0); 1175 } 1176 obj->dynsymcount += obj->symndx_gnu; 1177 } 1178 } 1179 1180 static void 1181 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1182 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1183 { 1184 1185 if (obj->z_origin && obj->origin_path == NULL) { 1186 obj->origin_path = xmalloc(PATH_MAX); 1187 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1188 die(); 1189 } 1190 1191 if (dyn_runpath != NULL) { 1192 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1193 if (obj->z_origin) 1194 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1195 } 1196 else if (dyn_rpath != NULL) { 1197 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1198 if (obj->z_origin) 1199 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1200 } 1201 1202 if (dyn_soname != NULL) 1203 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1204 } 1205 1206 static void 1207 digest_dynamic(Obj_Entry *obj, int early) 1208 { 1209 const Elf_Dyn *dyn_rpath; 1210 const Elf_Dyn *dyn_soname; 1211 const Elf_Dyn *dyn_runpath; 1212 1213 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1214 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1215 } 1216 1217 /* 1218 * Process a shared object's program header. This is used only for the 1219 * main program, when the kernel has already loaded the main program 1220 * into memory before calling the dynamic linker. It creates and 1221 * returns an Obj_Entry structure. 1222 */ 1223 static Obj_Entry * 1224 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1225 { 1226 Obj_Entry *obj; 1227 const Elf_Phdr *phlimit = phdr + phnum; 1228 const Elf_Phdr *ph; 1229 Elf_Addr note_start, note_end; 1230 int nsegs = 0; 1231 1232 obj = obj_new(); 1233 for (ph = phdr; ph < phlimit; ph++) { 1234 if (ph->p_type != PT_PHDR) 1235 continue; 1236 1237 obj->phdr = phdr; 1238 obj->phsize = ph->p_memsz; 1239 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1240 break; 1241 } 1242 1243 obj->stack_flags = PF_X | PF_R | PF_W; 1244 1245 for (ph = phdr; ph < phlimit; ph++) { 1246 switch (ph->p_type) { 1247 1248 case PT_INTERP: 1249 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1250 break; 1251 1252 case PT_LOAD: 1253 if (nsegs == 0) { /* First load segment */ 1254 obj->vaddrbase = trunc_page(ph->p_vaddr); 1255 obj->mapbase = obj->vaddrbase + obj->relocbase; 1256 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1257 obj->vaddrbase; 1258 } else { /* Last load segment */ 1259 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1260 obj->vaddrbase; 1261 } 1262 nsegs++; 1263 break; 1264 1265 case PT_DYNAMIC: 1266 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1267 break; 1268 1269 case PT_TLS: 1270 obj->tlsindex = 1; 1271 obj->tlssize = ph->p_memsz; 1272 obj->tlsalign = ph->p_align; 1273 obj->tlsinitsize = ph->p_filesz; 1274 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1275 break; 1276 1277 case PT_GNU_STACK: 1278 obj->stack_flags = ph->p_flags; 1279 break; 1280 1281 case PT_GNU_RELRO: 1282 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1283 obj->relro_size = round_page(ph->p_memsz); 1284 break; 1285 1286 case PT_NOTE: 1287 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1288 note_end = note_start + ph->p_filesz; 1289 digest_notes(obj, note_start, note_end); 1290 break; 1291 } 1292 } 1293 if (nsegs < 1) { 1294 _rtld_error("%s: too few PT_LOAD segments", path); 1295 return NULL; 1296 } 1297 1298 obj->entry = entry; 1299 return obj; 1300 } 1301 1302 void 1303 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1304 { 1305 const Elf_Note *note; 1306 const char *note_name; 1307 uintptr_t p; 1308 1309 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1310 note = (const Elf_Note *)((const char *)(note + 1) + 1311 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1312 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1313 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1314 note->n_descsz != sizeof(int32_t)) 1315 continue; 1316 if (note->n_type != ABI_NOTETYPE && 1317 note->n_type != CRT_NOINIT_NOTETYPE) 1318 continue; 1319 note_name = (const char *)(note + 1); 1320 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1321 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1322 continue; 1323 switch (note->n_type) { 1324 case ABI_NOTETYPE: 1325 /* FreeBSD osrel note */ 1326 p = (uintptr_t)(note + 1); 1327 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1328 obj->osrel = *(const int32_t *)(p); 1329 dbg("note osrel %d", obj->osrel); 1330 break; 1331 case CRT_NOINIT_NOTETYPE: 1332 /* FreeBSD 'crt does not call init' note */ 1333 obj->crt_no_init = true; 1334 dbg("note crt_no_init"); 1335 break; 1336 } 1337 } 1338 } 1339 1340 static Obj_Entry * 1341 dlcheck(void *handle) 1342 { 1343 Obj_Entry *obj; 1344 1345 for (obj = obj_list; obj != NULL; obj = obj->next) 1346 if (obj == (Obj_Entry *) handle) 1347 break; 1348 1349 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1350 _rtld_error("Invalid shared object handle %p", handle); 1351 return NULL; 1352 } 1353 return obj; 1354 } 1355 1356 /* 1357 * If the given object is already in the donelist, return true. Otherwise 1358 * add the object to the list and return false. 1359 */ 1360 static bool 1361 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1362 { 1363 unsigned int i; 1364 1365 for (i = 0; i < dlp->num_used; i++) 1366 if (dlp->objs[i] == obj) 1367 return true; 1368 /* 1369 * Our donelist allocation should always be sufficient. But if 1370 * our threads locking isn't working properly, more shared objects 1371 * could have been loaded since we allocated the list. That should 1372 * never happen, but we'll handle it properly just in case it does. 1373 */ 1374 if (dlp->num_used < dlp->num_alloc) 1375 dlp->objs[dlp->num_used++] = obj; 1376 return false; 1377 } 1378 1379 /* 1380 * Hash function for symbol table lookup. Don't even think about changing 1381 * this. It is specified by the System V ABI. 1382 */ 1383 unsigned long 1384 elf_hash(const char *name) 1385 { 1386 const unsigned char *p = (const unsigned char *) name; 1387 unsigned long h = 0; 1388 unsigned long g; 1389 1390 while (*p != '\0') { 1391 h = (h << 4) + *p++; 1392 if ((g = h & 0xf0000000) != 0) 1393 h ^= g >> 24; 1394 h &= ~g; 1395 } 1396 return h; 1397 } 1398 1399 /* 1400 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1401 * unsigned in case it's implemented with a wider type. 1402 */ 1403 static uint32_t 1404 gnu_hash(const char *s) 1405 { 1406 uint32_t h; 1407 unsigned char c; 1408 1409 h = 5381; 1410 for (c = *s; c != '\0'; c = *++s) 1411 h = h * 33 + c; 1412 return (h & 0xffffffff); 1413 } 1414 1415 /* 1416 * Find the library with the given name, and return its full pathname. 1417 * The returned string is dynamically allocated. Generates an error 1418 * message and returns NULL if the library cannot be found. 1419 * 1420 * If the second argument is non-NULL, then it refers to an already- 1421 * loaded shared object, whose library search path will be searched. 1422 * 1423 * The search order is: 1424 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1425 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1426 * LD_LIBRARY_PATH 1427 * DT_RUNPATH in the referencing file 1428 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1429 * from list) 1430 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1431 * 1432 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1433 */ 1434 static char * 1435 find_library(const char *xname, const Obj_Entry *refobj) 1436 { 1437 char *pathname; 1438 char *name; 1439 bool nodeflib, objgiven; 1440 1441 objgiven = refobj != NULL; 1442 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1443 if (xname[0] != '/' && !trust) { 1444 _rtld_error("Absolute pathname required for shared object \"%s\"", 1445 xname); 1446 return NULL; 1447 } 1448 if (objgiven && refobj->z_origin) { 1449 return (origin_subst(__DECONST(char *, xname), 1450 refobj->origin_path)); 1451 } else { 1452 return (xstrdup(xname)); 1453 } 1454 } 1455 1456 if (libmap_disable || !objgiven || 1457 (name = lm_find(refobj->path, xname)) == NULL) 1458 name = (char *)xname; 1459 1460 dbg(" Searching for \"%s\"", name); 1461 1462 /* 1463 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1464 * back to pre-conforming behaviour if user requested so with 1465 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1466 * nodeflib. 1467 */ 1468 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1469 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1470 (refobj != NULL && 1471 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1472 (pathname = search_library_path(name, gethints(false))) != NULL || 1473 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1474 return (pathname); 1475 } else { 1476 nodeflib = objgiven ? refobj->z_nodeflib : false; 1477 if ((objgiven && 1478 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1479 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1480 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1481 (pathname = search_library_path(name, ld_library_path)) != NULL || 1482 (objgiven && 1483 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1484 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1485 (objgiven && !nodeflib && 1486 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1487 return (pathname); 1488 } 1489 1490 if (objgiven && refobj->path != NULL) { 1491 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1492 name, basename(refobj->path)); 1493 } else { 1494 _rtld_error("Shared object \"%s\" not found", name); 1495 } 1496 return NULL; 1497 } 1498 1499 /* 1500 * Given a symbol number in a referencing object, find the corresponding 1501 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1502 * no definition was found. Returns a pointer to the Obj_Entry of the 1503 * defining object via the reference parameter DEFOBJ_OUT. 1504 */ 1505 const Elf_Sym * 1506 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1507 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1508 RtldLockState *lockstate) 1509 { 1510 const Elf_Sym *ref; 1511 const Elf_Sym *def; 1512 const Obj_Entry *defobj; 1513 SymLook req; 1514 const char *name; 1515 int res; 1516 1517 /* 1518 * If we have already found this symbol, get the information from 1519 * the cache. 1520 */ 1521 if (symnum >= refobj->dynsymcount) 1522 return NULL; /* Bad object */ 1523 if (cache != NULL && cache[symnum].sym != NULL) { 1524 *defobj_out = cache[symnum].obj; 1525 return cache[symnum].sym; 1526 } 1527 1528 ref = refobj->symtab + symnum; 1529 name = refobj->strtab + ref->st_name; 1530 def = NULL; 1531 defobj = NULL; 1532 1533 /* 1534 * We don't have to do a full scale lookup if the symbol is local. 1535 * We know it will bind to the instance in this load module; to 1536 * which we already have a pointer (ie ref). By not doing a lookup, 1537 * we not only improve performance, but it also avoids unresolvable 1538 * symbols when local symbols are not in the hash table. This has 1539 * been seen with the ia64 toolchain. 1540 */ 1541 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1542 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1543 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1544 symnum); 1545 } 1546 symlook_init(&req, name); 1547 req.flags = flags; 1548 req.ventry = fetch_ventry(refobj, symnum); 1549 req.lockstate = lockstate; 1550 res = symlook_default(&req, refobj); 1551 if (res == 0) { 1552 def = req.sym_out; 1553 defobj = req.defobj_out; 1554 } 1555 } else { 1556 def = ref; 1557 defobj = refobj; 1558 } 1559 1560 /* 1561 * If we found no definition and the reference is weak, treat the 1562 * symbol as having the value zero. 1563 */ 1564 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1565 def = &sym_zero; 1566 defobj = obj_main; 1567 } 1568 1569 if (def != NULL) { 1570 *defobj_out = defobj; 1571 /* Record the information in the cache to avoid subsequent lookups. */ 1572 if (cache != NULL) { 1573 cache[symnum].sym = def; 1574 cache[symnum].obj = defobj; 1575 } 1576 } else { 1577 if (refobj != &obj_rtld) 1578 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1579 } 1580 return def; 1581 } 1582 1583 /* 1584 * Return the search path from the ldconfig hints file, reading it if 1585 * necessary. If nostdlib is true, then the default search paths are 1586 * not added to result. 1587 * 1588 * Returns NULL if there are problems with the hints file, 1589 * or if the search path there is empty. 1590 */ 1591 static const char * 1592 gethints(bool nostdlib) 1593 { 1594 static char *hints, *filtered_path; 1595 struct elfhints_hdr hdr; 1596 struct fill_search_info_args sargs, hargs; 1597 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1598 struct dl_serpath *SLPpath, *hintpath; 1599 char *p; 1600 unsigned int SLPndx, hintndx, fndx, fcount; 1601 int fd; 1602 size_t flen; 1603 bool skip; 1604 1605 /* First call, read the hints file */ 1606 if (hints == NULL) { 1607 /* Keep from trying again in case the hints file is bad. */ 1608 hints = ""; 1609 1610 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1611 return (NULL); 1612 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1613 hdr.magic != ELFHINTS_MAGIC || 1614 hdr.version != 1) { 1615 close(fd); 1616 return (NULL); 1617 } 1618 p = xmalloc(hdr.dirlistlen + 1); 1619 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1620 read(fd, p, hdr.dirlistlen + 1) != 1621 (ssize_t)hdr.dirlistlen + 1) { 1622 free(p); 1623 close(fd); 1624 return (NULL); 1625 } 1626 hints = p; 1627 close(fd); 1628 } 1629 1630 /* 1631 * If caller agreed to receive list which includes the default 1632 * paths, we are done. Otherwise, if we still did not 1633 * calculated filtered result, do it now. 1634 */ 1635 if (!nostdlib) 1636 return (hints[0] != '\0' ? hints : NULL); 1637 if (filtered_path != NULL) 1638 goto filt_ret; 1639 1640 /* 1641 * Obtain the list of all configured search paths, and the 1642 * list of the default paths. 1643 * 1644 * First estimate the size of the results. 1645 */ 1646 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1647 smeta.dls_cnt = 0; 1648 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1649 hmeta.dls_cnt = 0; 1650 1651 sargs.request = RTLD_DI_SERINFOSIZE; 1652 sargs.serinfo = &smeta; 1653 hargs.request = RTLD_DI_SERINFOSIZE; 1654 hargs.serinfo = &hmeta; 1655 1656 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1657 path_enumerate(p, fill_search_info, &hargs); 1658 1659 SLPinfo = xmalloc(smeta.dls_size); 1660 hintinfo = xmalloc(hmeta.dls_size); 1661 1662 /* 1663 * Next fetch both sets of paths. 1664 */ 1665 sargs.request = RTLD_DI_SERINFO; 1666 sargs.serinfo = SLPinfo; 1667 sargs.serpath = &SLPinfo->dls_serpath[0]; 1668 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1669 1670 hargs.request = RTLD_DI_SERINFO; 1671 hargs.serinfo = hintinfo; 1672 hargs.serpath = &hintinfo->dls_serpath[0]; 1673 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1674 1675 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1676 path_enumerate(p, fill_search_info, &hargs); 1677 1678 /* 1679 * Now calculate the difference between two sets, by excluding 1680 * standard paths from the full set. 1681 */ 1682 fndx = 0; 1683 fcount = 0; 1684 filtered_path = xmalloc(hdr.dirlistlen + 1); 1685 hintpath = &hintinfo->dls_serpath[0]; 1686 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1687 skip = false; 1688 SLPpath = &SLPinfo->dls_serpath[0]; 1689 /* 1690 * Check each standard path against current. 1691 */ 1692 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1693 /* matched, skip the path */ 1694 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1695 skip = true; 1696 break; 1697 } 1698 } 1699 if (skip) 1700 continue; 1701 /* 1702 * Not matched against any standard path, add the path 1703 * to result. Separate consequtive paths with ':'. 1704 */ 1705 if (fcount > 0) { 1706 filtered_path[fndx] = ':'; 1707 fndx++; 1708 } 1709 fcount++; 1710 flen = strlen(hintpath->dls_name); 1711 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1712 fndx += flen; 1713 } 1714 filtered_path[fndx] = '\0'; 1715 1716 free(SLPinfo); 1717 free(hintinfo); 1718 1719 filt_ret: 1720 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1721 } 1722 1723 static void 1724 init_dag(Obj_Entry *root) 1725 { 1726 const Needed_Entry *needed; 1727 const Objlist_Entry *elm; 1728 DoneList donelist; 1729 1730 if (root->dag_inited) 1731 return; 1732 donelist_init(&donelist); 1733 1734 /* Root object belongs to own DAG. */ 1735 objlist_push_tail(&root->dldags, root); 1736 objlist_push_tail(&root->dagmembers, root); 1737 donelist_check(&donelist, root); 1738 1739 /* 1740 * Add dependencies of root object to DAG in breadth order 1741 * by exploiting the fact that each new object get added 1742 * to the tail of the dagmembers list. 1743 */ 1744 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1745 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1746 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1747 continue; 1748 objlist_push_tail(&needed->obj->dldags, root); 1749 objlist_push_tail(&root->dagmembers, needed->obj); 1750 } 1751 } 1752 root->dag_inited = true; 1753 } 1754 1755 static void 1756 process_nodelete(Obj_Entry *root) 1757 { 1758 const Objlist_Entry *elm; 1759 1760 /* 1761 * Walk over object DAG and process every dependent object that 1762 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1763 * which then should have its reference upped separately. 1764 */ 1765 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1766 if (elm->obj != NULL && elm->obj->z_nodelete && 1767 !elm->obj->ref_nodel) { 1768 dbg("obj %s nodelete", elm->obj->path); 1769 init_dag(elm->obj); 1770 ref_dag(elm->obj); 1771 elm->obj->ref_nodel = true; 1772 } 1773 } 1774 } 1775 /* 1776 * Initialize the dynamic linker. The argument is the address at which 1777 * the dynamic linker has been mapped into memory. The primary task of 1778 * this function is to relocate the dynamic linker. 1779 */ 1780 static void 1781 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1782 { 1783 Obj_Entry objtmp; /* Temporary rtld object */ 1784 const Elf_Dyn *dyn_rpath; 1785 const Elf_Dyn *dyn_soname; 1786 const Elf_Dyn *dyn_runpath; 1787 1788 /* 1789 * Conjure up an Obj_Entry structure for the dynamic linker. 1790 * 1791 * The "path" member can't be initialized yet because string constants 1792 * cannot yet be accessed. Below we will set it correctly. 1793 */ 1794 memset(&objtmp, 0, sizeof(objtmp)); 1795 objtmp.path = NULL; 1796 objtmp.rtld = true; 1797 objtmp.mapbase = mapbase; 1798 #ifdef PIC 1799 objtmp.relocbase = mapbase; 1800 #endif 1801 if (RTLD_IS_DYNAMIC()) { 1802 objtmp.dynamic = rtld_dynamic(&objtmp); 1803 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1804 assert(objtmp.needed == NULL); 1805 #if !defined(__mips__) 1806 /* MIPS has a bogus DT_TEXTREL. */ 1807 assert(!objtmp.textrel); 1808 #endif 1809 1810 /* 1811 * Temporarily put the dynamic linker entry into the object list, so 1812 * that symbols can be found. 1813 */ 1814 1815 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1816 } 1817 1818 /* Initialize the object list. */ 1819 obj_tail = &obj_list; 1820 1821 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1822 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1823 1824 if (aux_info[AT_PAGESZ] != NULL) 1825 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1826 if (aux_info[AT_OSRELDATE] != NULL) 1827 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1828 1829 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1830 1831 /* Replace the path with a dynamically allocated copy. */ 1832 obj_rtld.path = xstrdup(PATH_RTLD); 1833 1834 r_debug.r_brk = r_debug_state; 1835 r_debug.r_state = RT_CONSISTENT; 1836 } 1837 1838 /* 1839 * Add the init functions from a needed object list (and its recursive 1840 * needed objects) to "list". This is not used directly; it is a helper 1841 * function for initlist_add_objects(). The write lock must be held 1842 * when this function is called. 1843 */ 1844 static void 1845 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1846 { 1847 /* Recursively process the successor needed objects. */ 1848 if (needed->next != NULL) 1849 initlist_add_neededs(needed->next, list); 1850 1851 /* Process the current needed object. */ 1852 if (needed->obj != NULL) 1853 initlist_add_objects(needed->obj, &needed->obj->next, list); 1854 } 1855 1856 /* 1857 * Scan all of the DAGs rooted in the range of objects from "obj" to 1858 * "tail" and add their init functions to "list". This recurses over 1859 * the DAGs and ensure the proper init ordering such that each object's 1860 * needed libraries are initialized before the object itself. At the 1861 * same time, this function adds the objects to the global finalization 1862 * list "list_fini" in the opposite order. The write lock must be 1863 * held when this function is called. 1864 */ 1865 static void 1866 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1867 { 1868 1869 if (obj->init_scanned || obj->init_done) 1870 return; 1871 obj->init_scanned = true; 1872 1873 /* Recursively process the successor objects. */ 1874 if (&obj->next != tail) 1875 initlist_add_objects(obj->next, tail, list); 1876 1877 /* Recursively process the needed objects. */ 1878 if (obj->needed != NULL) 1879 initlist_add_neededs(obj->needed, list); 1880 if (obj->needed_filtees != NULL) 1881 initlist_add_neededs(obj->needed_filtees, list); 1882 if (obj->needed_aux_filtees != NULL) 1883 initlist_add_neededs(obj->needed_aux_filtees, list); 1884 1885 /* Add the object to the init list. */ 1886 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1887 obj->init_array != (Elf_Addr)NULL) 1888 objlist_push_tail(list, obj); 1889 1890 /* Add the object to the global fini list in the reverse order. */ 1891 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1892 && !obj->on_fini_list) { 1893 objlist_push_head(&list_fini, obj); 1894 obj->on_fini_list = true; 1895 } 1896 } 1897 1898 #ifndef FPTR_TARGET 1899 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1900 #endif 1901 1902 static void 1903 free_needed_filtees(Needed_Entry *n) 1904 { 1905 Needed_Entry *needed, *needed1; 1906 1907 for (needed = n; needed != NULL; needed = needed->next) { 1908 if (needed->obj != NULL) { 1909 dlclose(needed->obj); 1910 needed->obj = NULL; 1911 } 1912 } 1913 for (needed = n; needed != NULL; needed = needed1) { 1914 needed1 = needed->next; 1915 free(needed); 1916 } 1917 } 1918 1919 static void 1920 unload_filtees(Obj_Entry *obj) 1921 { 1922 1923 free_needed_filtees(obj->needed_filtees); 1924 obj->needed_filtees = NULL; 1925 free_needed_filtees(obj->needed_aux_filtees); 1926 obj->needed_aux_filtees = NULL; 1927 obj->filtees_loaded = false; 1928 } 1929 1930 static void 1931 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1932 RtldLockState *lockstate) 1933 { 1934 1935 for (; needed != NULL; needed = needed->next) { 1936 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1937 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1938 RTLD_LOCAL, lockstate); 1939 } 1940 } 1941 1942 static void 1943 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1944 { 1945 1946 lock_restart_for_upgrade(lockstate); 1947 if (!obj->filtees_loaded) { 1948 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1949 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1950 obj->filtees_loaded = true; 1951 } 1952 } 1953 1954 static int 1955 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1956 { 1957 Obj_Entry *obj1; 1958 1959 for (; needed != NULL; needed = needed->next) { 1960 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1961 flags & ~RTLD_LO_NOLOAD); 1962 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1963 return (-1); 1964 } 1965 return (0); 1966 } 1967 1968 /* 1969 * Given a shared object, traverse its list of needed objects, and load 1970 * each of them. Returns 0 on success. Generates an error message and 1971 * returns -1 on failure. 1972 */ 1973 static int 1974 load_needed_objects(Obj_Entry *first, int flags) 1975 { 1976 Obj_Entry *obj; 1977 1978 for (obj = first; obj != NULL; obj = obj->next) { 1979 if (process_needed(obj, obj->needed, flags) == -1) 1980 return (-1); 1981 } 1982 return (0); 1983 } 1984 1985 static int 1986 load_preload_objects(void) 1987 { 1988 char *p = ld_preload; 1989 Obj_Entry *obj; 1990 static const char delim[] = " \t:;"; 1991 1992 if (p == NULL) 1993 return 0; 1994 1995 p += strspn(p, delim); 1996 while (*p != '\0') { 1997 size_t len = strcspn(p, delim); 1998 char savech; 1999 2000 savech = p[len]; 2001 p[len] = '\0'; 2002 obj = load_object(p, -1, NULL, 0); 2003 if (obj == NULL) 2004 return -1; /* XXX - cleanup */ 2005 obj->z_interpose = true; 2006 p[len] = savech; 2007 p += len; 2008 p += strspn(p, delim); 2009 } 2010 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2011 return 0; 2012 } 2013 2014 static const char * 2015 printable_path(const char *path) 2016 { 2017 2018 return (path == NULL ? "<unknown>" : path); 2019 } 2020 2021 /* 2022 * Load a shared object into memory, if it is not already loaded. The 2023 * object may be specified by name or by user-supplied file descriptor 2024 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2025 * duplicate is. 2026 * 2027 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2028 * on failure. 2029 */ 2030 static Obj_Entry * 2031 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2032 { 2033 Obj_Entry *obj; 2034 int fd; 2035 struct stat sb; 2036 char *path; 2037 2038 if (name != NULL) { 2039 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2040 if (object_match_name(obj, name)) 2041 return (obj); 2042 } 2043 2044 path = find_library(name, refobj); 2045 if (path == NULL) 2046 return (NULL); 2047 } else 2048 path = NULL; 2049 2050 /* 2051 * If we didn't find a match by pathname, or the name is not 2052 * supplied, open the file and check again by device and inode. 2053 * This avoids false mismatches caused by multiple links or ".." 2054 * in pathnames. 2055 * 2056 * To avoid a race, we open the file and use fstat() rather than 2057 * using stat(). 2058 */ 2059 fd = -1; 2060 if (fd_u == -1) { 2061 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2062 _rtld_error("Cannot open \"%s\"", path); 2063 free(path); 2064 return (NULL); 2065 } 2066 } else { 2067 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2068 if (fd == -1) { 2069 _rtld_error("Cannot dup fd"); 2070 free(path); 2071 return (NULL); 2072 } 2073 } 2074 if (fstat(fd, &sb) == -1) { 2075 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2076 close(fd); 2077 free(path); 2078 return NULL; 2079 } 2080 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2081 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2082 break; 2083 if (obj != NULL && name != NULL) { 2084 object_add_name(obj, name); 2085 free(path); 2086 close(fd); 2087 return obj; 2088 } 2089 if (flags & RTLD_LO_NOLOAD) { 2090 free(path); 2091 close(fd); 2092 return (NULL); 2093 } 2094 2095 /* First use of this object, so we must map it in */ 2096 obj = do_load_object(fd, name, path, &sb, flags); 2097 if (obj == NULL) 2098 free(path); 2099 close(fd); 2100 2101 return obj; 2102 } 2103 2104 static Obj_Entry * 2105 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2106 int flags) 2107 { 2108 Obj_Entry *obj; 2109 struct statfs fs; 2110 2111 /* 2112 * but first, make sure that environment variables haven't been 2113 * used to circumvent the noexec flag on a filesystem. 2114 */ 2115 if (dangerous_ld_env) { 2116 if (fstatfs(fd, &fs) != 0) { 2117 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2118 return NULL; 2119 } 2120 if (fs.f_flags & MNT_NOEXEC) { 2121 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2122 return NULL; 2123 } 2124 } 2125 dbg("loading \"%s\"", printable_path(path)); 2126 obj = map_object(fd, printable_path(path), sbp); 2127 if (obj == NULL) 2128 return NULL; 2129 2130 /* 2131 * If DT_SONAME is present in the object, digest_dynamic2 already 2132 * added it to the object names. 2133 */ 2134 if (name != NULL) 2135 object_add_name(obj, name); 2136 obj->path = path; 2137 digest_dynamic(obj, 0); 2138 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2139 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2140 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2141 RTLD_LO_DLOPEN) { 2142 dbg("refusing to load non-loadable \"%s\"", obj->path); 2143 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2144 munmap(obj->mapbase, obj->mapsize); 2145 obj_free(obj); 2146 return (NULL); 2147 } 2148 2149 *obj_tail = obj; 2150 obj_tail = &obj->next; 2151 obj_count++; 2152 obj_loads++; 2153 linkmap_add(obj); /* for GDB & dlinfo() */ 2154 max_stack_flags |= obj->stack_flags; 2155 2156 dbg(" %p .. %p: %s", obj->mapbase, 2157 obj->mapbase + obj->mapsize - 1, obj->path); 2158 if (obj->textrel) 2159 dbg(" WARNING: %s has impure text", obj->path); 2160 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2161 obj->path); 2162 2163 return obj; 2164 } 2165 2166 static Obj_Entry * 2167 obj_from_addr(const void *addr) 2168 { 2169 Obj_Entry *obj; 2170 2171 for (obj = obj_list; obj != NULL; obj = obj->next) { 2172 if (addr < (void *) obj->mapbase) 2173 continue; 2174 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2175 return obj; 2176 } 2177 return NULL; 2178 } 2179 2180 static void 2181 preinit_main(void) 2182 { 2183 Elf_Addr *preinit_addr; 2184 int index; 2185 2186 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2187 if (preinit_addr == NULL) 2188 return; 2189 2190 for (index = 0; index < obj_main->preinit_array_num; index++) { 2191 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2192 dbg("calling preinit function for %s at %p", obj_main->path, 2193 (void *)preinit_addr[index]); 2194 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2195 0, 0, obj_main->path); 2196 call_init_pointer(obj_main, preinit_addr[index]); 2197 } 2198 } 2199 } 2200 2201 /* 2202 * Call the finalization functions for each of the objects in "list" 2203 * belonging to the DAG of "root" and referenced once. If NULL "root" 2204 * is specified, every finalization function will be called regardless 2205 * of the reference count and the list elements won't be freed. All of 2206 * the objects are expected to have non-NULL fini functions. 2207 */ 2208 static void 2209 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2210 { 2211 Objlist_Entry *elm; 2212 char *saved_msg; 2213 Elf_Addr *fini_addr; 2214 int index; 2215 2216 assert(root == NULL || root->refcount == 1); 2217 2218 /* 2219 * Preserve the current error message since a fini function might 2220 * call into the dynamic linker and overwrite it. 2221 */ 2222 saved_msg = errmsg_save(); 2223 do { 2224 STAILQ_FOREACH(elm, list, link) { 2225 if (root != NULL && (elm->obj->refcount != 1 || 2226 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2227 continue; 2228 /* Remove object from fini list to prevent recursive invocation. */ 2229 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2230 /* 2231 * XXX: If a dlopen() call references an object while the 2232 * fini function is in progress, we might end up trying to 2233 * unload the referenced object in dlclose() or the object 2234 * won't be unloaded although its fini function has been 2235 * called. 2236 */ 2237 lock_release(rtld_bind_lock, lockstate); 2238 2239 /* 2240 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2241 * When this happens, DT_FINI_ARRAY is processed first. 2242 */ 2243 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2244 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2245 for (index = elm->obj->fini_array_num - 1; index >= 0; 2246 index--) { 2247 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2248 dbg("calling fini function for %s at %p", 2249 elm->obj->path, (void *)fini_addr[index]); 2250 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2251 (void *)fini_addr[index], 0, 0, elm->obj->path); 2252 call_initfini_pointer(elm->obj, fini_addr[index]); 2253 } 2254 } 2255 } 2256 if (elm->obj->fini != (Elf_Addr)NULL) { 2257 dbg("calling fini function for %s at %p", elm->obj->path, 2258 (void *)elm->obj->fini); 2259 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2260 0, 0, elm->obj->path); 2261 call_initfini_pointer(elm->obj, elm->obj->fini); 2262 } 2263 wlock_acquire(rtld_bind_lock, lockstate); 2264 /* No need to free anything if process is going down. */ 2265 if (root != NULL) 2266 free(elm); 2267 /* 2268 * We must restart the list traversal after every fini call 2269 * because a dlclose() call from the fini function or from 2270 * another thread might have modified the reference counts. 2271 */ 2272 break; 2273 } 2274 } while (elm != NULL); 2275 errmsg_restore(saved_msg); 2276 } 2277 2278 /* 2279 * Call the initialization functions for each of the objects in 2280 * "list". All of the objects are expected to have non-NULL init 2281 * functions. 2282 */ 2283 static void 2284 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2285 { 2286 Objlist_Entry *elm; 2287 Obj_Entry *obj; 2288 char *saved_msg; 2289 Elf_Addr *init_addr; 2290 int index; 2291 2292 /* 2293 * Clean init_scanned flag so that objects can be rechecked and 2294 * possibly initialized earlier if any of vectors called below 2295 * cause the change by using dlopen. 2296 */ 2297 for (obj = obj_list; obj != NULL; obj = obj->next) 2298 obj->init_scanned = false; 2299 2300 /* 2301 * Preserve the current error message since an init function might 2302 * call into the dynamic linker and overwrite it. 2303 */ 2304 saved_msg = errmsg_save(); 2305 STAILQ_FOREACH(elm, list, link) { 2306 if (elm->obj->init_done) /* Initialized early. */ 2307 continue; 2308 /* 2309 * Race: other thread might try to use this object before current 2310 * one completes the initilization. Not much can be done here 2311 * without better locking. 2312 */ 2313 elm->obj->init_done = true; 2314 lock_release(rtld_bind_lock, lockstate); 2315 2316 /* 2317 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2318 * When this happens, DT_INIT is processed first. 2319 */ 2320 if (elm->obj->init != (Elf_Addr)NULL) { 2321 dbg("calling init function for %s at %p", elm->obj->path, 2322 (void *)elm->obj->init); 2323 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2324 0, 0, elm->obj->path); 2325 call_initfini_pointer(elm->obj, elm->obj->init); 2326 } 2327 init_addr = (Elf_Addr *)elm->obj->init_array; 2328 if (init_addr != NULL) { 2329 for (index = 0; index < elm->obj->init_array_num; index++) { 2330 if (init_addr[index] != 0 && init_addr[index] != 1) { 2331 dbg("calling init function for %s at %p", elm->obj->path, 2332 (void *)init_addr[index]); 2333 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2334 (void *)init_addr[index], 0, 0, elm->obj->path); 2335 call_init_pointer(elm->obj, init_addr[index]); 2336 } 2337 } 2338 } 2339 wlock_acquire(rtld_bind_lock, lockstate); 2340 } 2341 errmsg_restore(saved_msg); 2342 } 2343 2344 static void 2345 objlist_clear(Objlist *list) 2346 { 2347 Objlist_Entry *elm; 2348 2349 while (!STAILQ_EMPTY(list)) { 2350 elm = STAILQ_FIRST(list); 2351 STAILQ_REMOVE_HEAD(list, link); 2352 free(elm); 2353 } 2354 } 2355 2356 static Objlist_Entry * 2357 objlist_find(Objlist *list, const Obj_Entry *obj) 2358 { 2359 Objlist_Entry *elm; 2360 2361 STAILQ_FOREACH(elm, list, link) 2362 if (elm->obj == obj) 2363 return elm; 2364 return NULL; 2365 } 2366 2367 static void 2368 objlist_init(Objlist *list) 2369 { 2370 STAILQ_INIT(list); 2371 } 2372 2373 static void 2374 objlist_push_head(Objlist *list, Obj_Entry *obj) 2375 { 2376 Objlist_Entry *elm; 2377 2378 elm = NEW(Objlist_Entry); 2379 elm->obj = obj; 2380 STAILQ_INSERT_HEAD(list, elm, link); 2381 } 2382 2383 static void 2384 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2385 { 2386 Objlist_Entry *elm; 2387 2388 elm = NEW(Objlist_Entry); 2389 elm->obj = obj; 2390 STAILQ_INSERT_TAIL(list, elm, link); 2391 } 2392 2393 static void 2394 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2395 { 2396 Objlist_Entry *elm, *listelm; 2397 2398 STAILQ_FOREACH(listelm, list, link) { 2399 if (listelm->obj == listobj) 2400 break; 2401 } 2402 elm = NEW(Objlist_Entry); 2403 elm->obj = obj; 2404 if (listelm != NULL) 2405 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2406 else 2407 STAILQ_INSERT_TAIL(list, elm, link); 2408 } 2409 2410 static void 2411 objlist_remove(Objlist *list, Obj_Entry *obj) 2412 { 2413 Objlist_Entry *elm; 2414 2415 if ((elm = objlist_find(list, obj)) != NULL) { 2416 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2417 free(elm); 2418 } 2419 } 2420 2421 /* 2422 * Relocate dag rooted in the specified object. 2423 * Returns 0 on success, or -1 on failure. 2424 */ 2425 2426 static int 2427 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2428 int flags, RtldLockState *lockstate) 2429 { 2430 Objlist_Entry *elm; 2431 int error; 2432 2433 error = 0; 2434 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2435 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2436 lockstate); 2437 if (error == -1) 2438 break; 2439 } 2440 return (error); 2441 } 2442 2443 /* 2444 * Relocate single object. 2445 * Returns 0 on success, or -1 on failure. 2446 */ 2447 static int 2448 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2449 int flags, RtldLockState *lockstate) 2450 { 2451 2452 if (obj->relocated) 2453 return (0); 2454 obj->relocated = true; 2455 if (obj != rtldobj) 2456 dbg("relocating \"%s\"", obj->path); 2457 2458 if (obj->symtab == NULL || obj->strtab == NULL || 2459 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2460 _rtld_error("%s: Shared object has no run-time symbol table", 2461 obj->path); 2462 return (-1); 2463 } 2464 2465 if (obj->textrel) { 2466 /* There are relocations to the write-protected text segment. */ 2467 if (mprotect(obj->mapbase, obj->textsize, 2468 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2469 _rtld_error("%s: Cannot write-enable text segment: %s", 2470 obj->path, rtld_strerror(errno)); 2471 return (-1); 2472 } 2473 } 2474 2475 /* Process the non-PLT relocations. */ 2476 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2477 return (-1); 2478 2479 if (obj->textrel) { /* Re-protected the text segment. */ 2480 if (mprotect(obj->mapbase, obj->textsize, 2481 PROT_READ|PROT_EXEC) == -1) { 2482 _rtld_error("%s: Cannot write-protect text segment: %s", 2483 obj->path, rtld_strerror(errno)); 2484 return (-1); 2485 } 2486 } 2487 2488 2489 /* Set the special PLT or GOT entries. */ 2490 init_pltgot(obj); 2491 2492 /* Process the PLT relocations. */ 2493 if (reloc_plt(obj) == -1) 2494 return (-1); 2495 /* Relocate the jump slots if we are doing immediate binding. */ 2496 if (obj->bind_now || bind_now) 2497 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2498 return (-1); 2499 2500 if (obj->relro_size > 0) { 2501 if (mprotect(obj->relro_page, obj->relro_size, 2502 PROT_READ) == -1) { 2503 _rtld_error("%s: Cannot enforce relro protection: %s", 2504 obj->path, rtld_strerror(errno)); 2505 return (-1); 2506 } 2507 } 2508 2509 /* 2510 * Set up the magic number and version in the Obj_Entry. These 2511 * were checked in the crt1.o from the original ElfKit, so we 2512 * set them for backward compatibility. 2513 */ 2514 obj->magic = RTLD_MAGIC; 2515 obj->version = RTLD_VERSION; 2516 2517 return (0); 2518 } 2519 2520 /* 2521 * Relocate newly-loaded shared objects. The argument is a pointer to 2522 * the Obj_Entry for the first such object. All objects from the first 2523 * to the end of the list of objects are relocated. Returns 0 on success, 2524 * or -1 on failure. 2525 */ 2526 static int 2527 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2528 int flags, RtldLockState *lockstate) 2529 { 2530 Obj_Entry *obj; 2531 int error; 2532 2533 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2534 error = relocate_object(obj, bind_now, rtldobj, flags, 2535 lockstate); 2536 if (error == -1) 2537 break; 2538 } 2539 return (error); 2540 } 2541 2542 /* 2543 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2544 * referencing STT_GNU_IFUNC symbols is postponed till the other 2545 * relocations are done. The indirect functions specified as 2546 * ifunc are allowed to call other symbols, so we need to have 2547 * objects relocated before asking for resolution from indirects. 2548 * 2549 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2550 * instead of the usual lazy handling of PLT slots. It is 2551 * consistent with how GNU does it. 2552 */ 2553 static int 2554 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2555 RtldLockState *lockstate) 2556 { 2557 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2558 return (-1); 2559 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2560 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2561 return (-1); 2562 return (0); 2563 } 2564 2565 static int 2566 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2567 RtldLockState *lockstate) 2568 { 2569 Obj_Entry *obj; 2570 2571 for (obj = first; obj != NULL; obj = obj->next) { 2572 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2573 return (-1); 2574 } 2575 return (0); 2576 } 2577 2578 static int 2579 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2580 RtldLockState *lockstate) 2581 { 2582 Objlist_Entry *elm; 2583 2584 STAILQ_FOREACH(elm, list, link) { 2585 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2586 lockstate) == -1) 2587 return (-1); 2588 } 2589 return (0); 2590 } 2591 2592 /* 2593 * Cleanup procedure. It will be called (by the atexit mechanism) just 2594 * before the process exits. 2595 */ 2596 static void 2597 rtld_exit(void) 2598 { 2599 RtldLockState lockstate; 2600 2601 wlock_acquire(rtld_bind_lock, &lockstate); 2602 dbg("rtld_exit()"); 2603 objlist_call_fini(&list_fini, NULL, &lockstate); 2604 /* No need to remove the items from the list, since we are exiting. */ 2605 if (!libmap_disable) 2606 lm_fini(); 2607 lock_release(rtld_bind_lock, &lockstate); 2608 } 2609 2610 /* 2611 * Iterate over a search path, translate each element, and invoke the 2612 * callback on the result. 2613 */ 2614 static void * 2615 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2616 { 2617 const char *trans; 2618 if (path == NULL) 2619 return (NULL); 2620 2621 path += strspn(path, ":;"); 2622 while (*path != '\0') { 2623 size_t len; 2624 char *res; 2625 2626 len = strcspn(path, ":;"); 2627 trans = lm_findn(NULL, path, len); 2628 if (trans) 2629 res = callback(trans, strlen(trans), arg); 2630 else 2631 res = callback(path, len, arg); 2632 2633 if (res != NULL) 2634 return (res); 2635 2636 path += len; 2637 path += strspn(path, ":;"); 2638 } 2639 2640 return (NULL); 2641 } 2642 2643 struct try_library_args { 2644 const char *name; 2645 size_t namelen; 2646 char *buffer; 2647 size_t buflen; 2648 }; 2649 2650 static void * 2651 try_library_path(const char *dir, size_t dirlen, void *param) 2652 { 2653 struct try_library_args *arg; 2654 2655 arg = param; 2656 if (*dir == '/' || trust) { 2657 char *pathname; 2658 2659 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2660 return (NULL); 2661 2662 pathname = arg->buffer; 2663 strncpy(pathname, dir, dirlen); 2664 pathname[dirlen] = '/'; 2665 strcpy(pathname + dirlen + 1, arg->name); 2666 2667 dbg(" Trying \"%s\"", pathname); 2668 if (access(pathname, F_OK) == 0) { /* We found it */ 2669 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2670 strcpy(pathname, arg->buffer); 2671 return (pathname); 2672 } 2673 } 2674 return (NULL); 2675 } 2676 2677 static char * 2678 search_library_path(const char *name, const char *path) 2679 { 2680 char *p; 2681 struct try_library_args arg; 2682 2683 if (path == NULL) 2684 return NULL; 2685 2686 arg.name = name; 2687 arg.namelen = strlen(name); 2688 arg.buffer = xmalloc(PATH_MAX); 2689 arg.buflen = PATH_MAX; 2690 2691 p = path_enumerate(path, try_library_path, &arg); 2692 2693 free(arg.buffer); 2694 2695 return (p); 2696 } 2697 2698 int 2699 dlclose(void *handle) 2700 { 2701 Obj_Entry *root; 2702 RtldLockState lockstate; 2703 2704 wlock_acquire(rtld_bind_lock, &lockstate); 2705 root = dlcheck(handle); 2706 if (root == NULL) { 2707 lock_release(rtld_bind_lock, &lockstate); 2708 return -1; 2709 } 2710 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2711 root->path); 2712 2713 /* Unreference the object and its dependencies. */ 2714 root->dl_refcount--; 2715 2716 if (root->refcount == 1) { 2717 /* 2718 * The object will be no longer referenced, so we must unload it. 2719 * First, call the fini functions. 2720 */ 2721 objlist_call_fini(&list_fini, root, &lockstate); 2722 2723 unref_dag(root); 2724 2725 /* Finish cleaning up the newly-unreferenced objects. */ 2726 GDB_STATE(RT_DELETE,&root->linkmap); 2727 unload_object(root); 2728 GDB_STATE(RT_CONSISTENT,NULL); 2729 } else 2730 unref_dag(root); 2731 2732 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2733 lock_release(rtld_bind_lock, &lockstate); 2734 return 0; 2735 } 2736 2737 char * 2738 dlerror(void) 2739 { 2740 char *msg = error_message; 2741 error_message = NULL; 2742 return msg; 2743 } 2744 2745 /* 2746 * This function is deprecated and has no effect. 2747 */ 2748 void 2749 dllockinit(void *context, 2750 void *(*lock_create)(void *context), 2751 void (*rlock_acquire)(void *lock), 2752 void (*wlock_acquire)(void *lock), 2753 void (*lock_release)(void *lock), 2754 void (*lock_destroy)(void *lock), 2755 void (*context_destroy)(void *context)) 2756 { 2757 static void *cur_context; 2758 static void (*cur_context_destroy)(void *); 2759 2760 /* Just destroy the context from the previous call, if necessary. */ 2761 if (cur_context_destroy != NULL) 2762 cur_context_destroy(cur_context); 2763 cur_context = context; 2764 cur_context_destroy = context_destroy; 2765 } 2766 2767 void * 2768 dlopen(const char *name, int mode) 2769 { 2770 2771 return (rtld_dlopen(name, -1, mode)); 2772 } 2773 2774 void * 2775 fdlopen(int fd, int mode) 2776 { 2777 2778 return (rtld_dlopen(NULL, fd, mode)); 2779 } 2780 2781 static void * 2782 rtld_dlopen(const char *name, int fd, int mode) 2783 { 2784 RtldLockState lockstate; 2785 int lo_flags; 2786 2787 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2788 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2789 if (ld_tracing != NULL) { 2790 rlock_acquire(rtld_bind_lock, &lockstate); 2791 if (sigsetjmp(lockstate.env, 0) != 0) 2792 lock_upgrade(rtld_bind_lock, &lockstate); 2793 environ = (char **)*get_program_var_addr("environ", &lockstate); 2794 lock_release(rtld_bind_lock, &lockstate); 2795 } 2796 lo_flags = RTLD_LO_DLOPEN; 2797 if (mode & RTLD_NODELETE) 2798 lo_flags |= RTLD_LO_NODELETE; 2799 if (mode & RTLD_NOLOAD) 2800 lo_flags |= RTLD_LO_NOLOAD; 2801 if (ld_tracing != NULL) 2802 lo_flags |= RTLD_LO_TRACE; 2803 2804 return (dlopen_object(name, fd, obj_main, lo_flags, 2805 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2806 } 2807 2808 static void 2809 dlopen_cleanup(Obj_Entry *obj) 2810 { 2811 2812 obj->dl_refcount--; 2813 unref_dag(obj); 2814 if (obj->refcount == 0) 2815 unload_object(obj); 2816 } 2817 2818 static Obj_Entry * 2819 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2820 int mode, RtldLockState *lockstate) 2821 { 2822 Obj_Entry **old_obj_tail; 2823 Obj_Entry *obj; 2824 Objlist initlist; 2825 RtldLockState mlockstate; 2826 int result; 2827 2828 objlist_init(&initlist); 2829 2830 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2831 wlock_acquire(rtld_bind_lock, &mlockstate); 2832 lockstate = &mlockstate; 2833 } 2834 GDB_STATE(RT_ADD,NULL); 2835 2836 old_obj_tail = obj_tail; 2837 obj = NULL; 2838 if (name == NULL && fd == -1) { 2839 obj = obj_main; 2840 obj->refcount++; 2841 } else { 2842 obj = load_object(name, fd, refobj, lo_flags); 2843 } 2844 2845 if (obj) { 2846 obj->dl_refcount++; 2847 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2848 objlist_push_tail(&list_global, obj); 2849 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2850 assert(*old_obj_tail == obj); 2851 result = load_needed_objects(obj, 2852 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2853 init_dag(obj); 2854 ref_dag(obj); 2855 if (result != -1) 2856 result = rtld_verify_versions(&obj->dagmembers); 2857 if (result != -1 && ld_tracing) 2858 goto trace; 2859 if (result == -1 || relocate_object_dag(obj, 2860 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2861 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2862 lockstate) == -1) { 2863 dlopen_cleanup(obj); 2864 obj = NULL; 2865 } else if (lo_flags & RTLD_LO_EARLY) { 2866 /* 2867 * Do not call the init functions for early loaded 2868 * filtees. The image is still not initialized enough 2869 * for them to work. 2870 * 2871 * Our object is found by the global object list and 2872 * will be ordered among all init calls done right 2873 * before transferring control to main. 2874 */ 2875 } else { 2876 /* Make list of init functions to call. */ 2877 initlist_add_objects(obj, &obj->next, &initlist); 2878 } 2879 /* 2880 * Process all no_delete objects here, given them own 2881 * DAGs to prevent their dependencies from being unloaded. 2882 * This has to be done after we have loaded all of the 2883 * dependencies, so that we do not miss any. 2884 */ 2885 if (obj != NULL) 2886 process_nodelete(obj); 2887 } else { 2888 /* 2889 * Bump the reference counts for objects on this DAG. If 2890 * this is the first dlopen() call for the object that was 2891 * already loaded as a dependency, initialize the dag 2892 * starting at it. 2893 */ 2894 init_dag(obj); 2895 ref_dag(obj); 2896 2897 if ((lo_flags & RTLD_LO_TRACE) != 0) 2898 goto trace; 2899 } 2900 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2901 obj->z_nodelete) && !obj->ref_nodel) { 2902 dbg("obj %s nodelete", obj->path); 2903 ref_dag(obj); 2904 obj->z_nodelete = obj->ref_nodel = true; 2905 } 2906 } 2907 2908 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2909 name); 2910 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2911 2912 if (!(lo_flags & RTLD_LO_EARLY)) { 2913 map_stacks_exec(lockstate); 2914 } 2915 2916 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2917 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2918 lockstate) == -1) { 2919 objlist_clear(&initlist); 2920 dlopen_cleanup(obj); 2921 if (lockstate == &mlockstate) 2922 lock_release(rtld_bind_lock, lockstate); 2923 return (NULL); 2924 } 2925 2926 if (!(lo_flags & RTLD_LO_EARLY)) { 2927 /* Call the init functions. */ 2928 objlist_call_init(&initlist, lockstate); 2929 } 2930 objlist_clear(&initlist); 2931 if (lockstate == &mlockstate) 2932 lock_release(rtld_bind_lock, lockstate); 2933 return obj; 2934 trace: 2935 trace_loaded_objects(obj); 2936 if (lockstate == &mlockstate) 2937 lock_release(rtld_bind_lock, lockstate); 2938 exit(0); 2939 } 2940 2941 static void * 2942 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2943 int flags) 2944 { 2945 DoneList donelist; 2946 const Obj_Entry *obj, *defobj; 2947 const Elf_Sym *def; 2948 SymLook req; 2949 RtldLockState lockstate; 2950 #ifndef __ia64__ 2951 tls_index ti; 2952 #endif 2953 int res; 2954 2955 def = NULL; 2956 defobj = NULL; 2957 symlook_init(&req, name); 2958 req.ventry = ve; 2959 req.flags = flags | SYMLOOK_IN_PLT; 2960 req.lockstate = &lockstate; 2961 2962 rlock_acquire(rtld_bind_lock, &lockstate); 2963 if (sigsetjmp(lockstate.env, 0) != 0) 2964 lock_upgrade(rtld_bind_lock, &lockstate); 2965 if (handle == NULL || handle == RTLD_NEXT || 2966 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2967 2968 if ((obj = obj_from_addr(retaddr)) == NULL) { 2969 _rtld_error("Cannot determine caller's shared object"); 2970 lock_release(rtld_bind_lock, &lockstate); 2971 return NULL; 2972 } 2973 if (handle == NULL) { /* Just the caller's shared object. */ 2974 res = symlook_obj(&req, obj); 2975 if (res == 0) { 2976 def = req.sym_out; 2977 defobj = req.defobj_out; 2978 } 2979 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2980 handle == RTLD_SELF) { /* ... caller included */ 2981 if (handle == RTLD_NEXT) 2982 obj = obj->next; 2983 for (; obj != NULL; obj = obj->next) { 2984 res = symlook_obj(&req, obj); 2985 if (res == 0) { 2986 if (def == NULL || 2987 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2988 def = req.sym_out; 2989 defobj = req.defobj_out; 2990 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2991 break; 2992 } 2993 } 2994 } 2995 /* 2996 * Search the dynamic linker itself, and possibly resolve the 2997 * symbol from there. This is how the application links to 2998 * dynamic linker services such as dlopen. 2999 */ 3000 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3001 res = symlook_obj(&req, &obj_rtld); 3002 if (res == 0) { 3003 def = req.sym_out; 3004 defobj = req.defobj_out; 3005 } 3006 } 3007 } else { 3008 assert(handle == RTLD_DEFAULT); 3009 res = symlook_default(&req, obj); 3010 if (res == 0) { 3011 defobj = req.defobj_out; 3012 def = req.sym_out; 3013 } 3014 } 3015 } else { 3016 if ((obj = dlcheck(handle)) == NULL) { 3017 lock_release(rtld_bind_lock, &lockstate); 3018 return NULL; 3019 } 3020 3021 donelist_init(&donelist); 3022 if (obj->mainprog) { 3023 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3024 res = symlook_global(&req, &donelist); 3025 if (res == 0) { 3026 def = req.sym_out; 3027 defobj = req.defobj_out; 3028 } 3029 /* 3030 * Search the dynamic linker itself, and possibly resolve the 3031 * symbol from there. This is how the application links to 3032 * dynamic linker services such as dlopen. 3033 */ 3034 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3035 res = symlook_obj(&req, &obj_rtld); 3036 if (res == 0) { 3037 def = req.sym_out; 3038 defobj = req.defobj_out; 3039 } 3040 } 3041 } 3042 else { 3043 /* Search the whole DAG rooted at the given object. */ 3044 res = symlook_list(&req, &obj->dagmembers, &donelist); 3045 if (res == 0) { 3046 def = req.sym_out; 3047 defobj = req.defobj_out; 3048 } 3049 } 3050 } 3051 3052 if (def != NULL) { 3053 lock_release(rtld_bind_lock, &lockstate); 3054 3055 /* 3056 * The value required by the caller is derived from the value 3057 * of the symbol. For the ia64 architecture, we need to 3058 * construct a function descriptor which the caller can use to 3059 * call the function with the right 'gp' value. For other 3060 * architectures and for non-functions, the value is simply 3061 * the relocated value of the symbol. 3062 */ 3063 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3064 return (make_function_pointer(def, defobj)); 3065 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3066 return (rtld_resolve_ifunc(defobj, def)); 3067 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3068 #ifdef __ia64__ 3069 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3070 #else 3071 ti.ti_module = defobj->tlsindex; 3072 ti.ti_offset = def->st_value; 3073 return (__tls_get_addr(&ti)); 3074 #endif 3075 } else 3076 return (defobj->relocbase + def->st_value); 3077 } 3078 3079 _rtld_error("Undefined symbol \"%s\"", name); 3080 lock_release(rtld_bind_lock, &lockstate); 3081 return NULL; 3082 } 3083 3084 void * 3085 dlsym(void *handle, const char *name) 3086 { 3087 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3088 SYMLOOK_DLSYM); 3089 } 3090 3091 dlfunc_t 3092 dlfunc(void *handle, const char *name) 3093 { 3094 union { 3095 void *d; 3096 dlfunc_t f; 3097 } rv; 3098 3099 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3100 SYMLOOK_DLSYM); 3101 return (rv.f); 3102 } 3103 3104 void * 3105 dlvsym(void *handle, const char *name, const char *version) 3106 { 3107 Ver_Entry ventry; 3108 3109 ventry.name = version; 3110 ventry.file = NULL; 3111 ventry.hash = elf_hash(version); 3112 ventry.flags= 0; 3113 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3114 SYMLOOK_DLSYM); 3115 } 3116 3117 int 3118 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3119 { 3120 const Obj_Entry *obj; 3121 RtldLockState lockstate; 3122 3123 rlock_acquire(rtld_bind_lock, &lockstate); 3124 obj = obj_from_addr(addr); 3125 if (obj == NULL) { 3126 _rtld_error("No shared object contains address"); 3127 lock_release(rtld_bind_lock, &lockstate); 3128 return (0); 3129 } 3130 rtld_fill_dl_phdr_info(obj, phdr_info); 3131 lock_release(rtld_bind_lock, &lockstate); 3132 return (1); 3133 } 3134 3135 int 3136 dladdr(const void *addr, Dl_info *info) 3137 { 3138 const Obj_Entry *obj; 3139 const Elf_Sym *def; 3140 void *symbol_addr; 3141 unsigned long symoffset; 3142 RtldLockState lockstate; 3143 3144 rlock_acquire(rtld_bind_lock, &lockstate); 3145 obj = obj_from_addr(addr); 3146 if (obj == NULL) { 3147 _rtld_error("No shared object contains address"); 3148 lock_release(rtld_bind_lock, &lockstate); 3149 return 0; 3150 } 3151 info->dli_fname = obj->path; 3152 info->dli_fbase = obj->mapbase; 3153 info->dli_saddr = (void *)0; 3154 info->dli_sname = NULL; 3155 3156 /* 3157 * Walk the symbol list looking for the symbol whose address is 3158 * closest to the address sent in. 3159 */ 3160 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3161 def = obj->symtab + symoffset; 3162 3163 /* 3164 * For skip the symbol if st_shndx is either SHN_UNDEF or 3165 * SHN_COMMON. 3166 */ 3167 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3168 continue; 3169 3170 /* 3171 * If the symbol is greater than the specified address, or if it 3172 * is further away from addr than the current nearest symbol, 3173 * then reject it. 3174 */ 3175 symbol_addr = obj->relocbase + def->st_value; 3176 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3177 continue; 3178 3179 /* Update our idea of the nearest symbol. */ 3180 info->dli_sname = obj->strtab + def->st_name; 3181 info->dli_saddr = symbol_addr; 3182 3183 /* Exact match? */ 3184 if (info->dli_saddr == addr) 3185 break; 3186 } 3187 lock_release(rtld_bind_lock, &lockstate); 3188 return 1; 3189 } 3190 3191 int 3192 dlinfo(void *handle, int request, void *p) 3193 { 3194 const Obj_Entry *obj; 3195 RtldLockState lockstate; 3196 int error; 3197 3198 rlock_acquire(rtld_bind_lock, &lockstate); 3199 3200 if (handle == NULL || handle == RTLD_SELF) { 3201 void *retaddr; 3202 3203 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3204 if ((obj = obj_from_addr(retaddr)) == NULL) 3205 _rtld_error("Cannot determine caller's shared object"); 3206 } else 3207 obj = dlcheck(handle); 3208 3209 if (obj == NULL) { 3210 lock_release(rtld_bind_lock, &lockstate); 3211 return (-1); 3212 } 3213 3214 error = 0; 3215 switch (request) { 3216 case RTLD_DI_LINKMAP: 3217 *((struct link_map const **)p) = &obj->linkmap; 3218 break; 3219 case RTLD_DI_ORIGIN: 3220 error = rtld_dirname(obj->path, p); 3221 break; 3222 3223 case RTLD_DI_SERINFOSIZE: 3224 case RTLD_DI_SERINFO: 3225 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3226 break; 3227 3228 default: 3229 _rtld_error("Invalid request %d passed to dlinfo()", request); 3230 error = -1; 3231 } 3232 3233 lock_release(rtld_bind_lock, &lockstate); 3234 3235 return (error); 3236 } 3237 3238 static void 3239 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3240 { 3241 3242 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3243 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 3244 STAILQ_FIRST(&obj->names)->name : obj->path; 3245 phdr_info->dlpi_phdr = obj->phdr; 3246 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3247 phdr_info->dlpi_tls_modid = obj->tlsindex; 3248 phdr_info->dlpi_tls_data = obj->tlsinit; 3249 phdr_info->dlpi_adds = obj_loads; 3250 phdr_info->dlpi_subs = obj_loads - obj_count; 3251 } 3252 3253 int 3254 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3255 { 3256 struct dl_phdr_info phdr_info; 3257 const Obj_Entry *obj; 3258 RtldLockState bind_lockstate, phdr_lockstate; 3259 int error; 3260 3261 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3262 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3263 3264 error = 0; 3265 3266 for (obj = obj_list; obj != NULL; obj = obj->next) { 3267 rtld_fill_dl_phdr_info(obj, &phdr_info); 3268 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3269 break; 3270 3271 } 3272 lock_release(rtld_bind_lock, &bind_lockstate); 3273 lock_release(rtld_phdr_lock, &phdr_lockstate); 3274 3275 return (error); 3276 } 3277 3278 static void * 3279 fill_search_info(const char *dir, size_t dirlen, void *param) 3280 { 3281 struct fill_search_info_args *arg; 3282 3283 arg = param; 3284 3285 if (arg->request == RTLD_DI_SERINFOSIZE) { 3286 arg->serinfo->dls_cnt ++; 3287 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3288 } else { 3289 struct dl_serpath *s_entry; 3290 3291 s_entry = arg->serpath; 3292 s_entry->dls_name = arg->strspace; 3293 s_entry->dls_flags = arg->flags; 3294 3295 strncpy(arg->strspace, dir, dirlen); 3296 arg->strspace[dirlen] = '\0'; 3297 3298 arg->strspace += dirlen + 1; 3299 arg->serpath++; 3300 } 3301 3302 return (NULL); 3303 } 3304 3305 static int 3306 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3307 { 3308 struct dl_serinfo _info; 3309 struct fill_search_info_args args; 3310 3311 args.request = RTLD_DI_SERINFOSIZE; 3312 args.serinfo = &_info; 3313 3314 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3315 _info.dls_cnt = 0; 3316 3317 path_enumerate(obj->rpath, fill_search_info, &args); 3318 path_enumerate(ld_library_path, fill_search_info, &args); 3319 path_enumerate(obj->runpath, fill_search_info, &args); 3320 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3321 if (!obj->z_nodeflib) 3322 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3323 3324 3325 if (request == RTLD_DI_SERINFOSIZE) { 3326 info->dls_size = _info.dls_size; 3327 info->dls_cnt = _info.dls_cnt; 3328 return (0); 3329 } 3330 3331 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3332 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3333 return (-1); 3334 } 3335 3336 args.request = RTLD_DI_SERINFO; 3337 args.serinfo = info; 3338 args.serpath = &info->dls_serpath[0]; 3339 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3340 3341 args.flags = LA_SER_RUNPATH; 3342 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3343 return (-1); 3344 3345 args.flags = LA_SER_LIBPATH; 3346 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3347 return (-1); 3348 3349 args.flags = LA_SER_RUNPATH; 3350 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3351 return (-1); 3352 3353 args.flags = LA_SER_CONFIG; 3354 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3355 != NULL) 3356 return (-1); 3357 3358 args.flags = LA_SER_DEFAULT; 3359 if (!obj->z_nodeflib && 3360 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3361 return (-1); 3362 return (0); 3363 } 3364 3365 static int 3366 rtld_dirname(const char *path, char *bname) 3367 { 3368 const char *endp; 3369 3370 /* Empty or NULL string gets treated as "." */ 3371 if (path == NULL || *path == '\0') { 3372 bname[0] = '.'; 3373 bname[1] = '\0'; 3374 return (0); 3375 } 3376 3377 /* Strip trailing slashes */ 3378 endp = path + strlen(path) - 1; 3379 while (endp > path && *endp == '/') 3380 endp--; 3381 3382 /* Find the start of the dir */ 3383 while (endp > path && *endp != '/') 3384 endp--; 3385 3386 /* Either the dir is "/" or there are no slashes */ 3387 if (endp == path) { 3388 bname[0] = *endp == '/' ? '/' : '.'; 3389 bname[1] = '\0'; 3390 return (0); 3391 } else { 3392 do { 3393 endp--; 3394 } while (endp > path && *endp == '/'); 3395 } 3396 3397 if (endp - path + 2 > PATH_MAX) 3398 { 3399 _rtld_error("Filename is too long: %s", path); 3400 return(-1); 3401 } 3402 3403 strncpy(bname, path, endp - path + 1); 3404 bname[endp - path + 1] = '\0'; 3405 return (0); 3406 } 3407 3408 static int 3409 rtld_dirname_abs(const char *path, char *base) 3410 { 3411 char base_rel[PATH_MAX]; 3412 3413 if (rtld_dirname(path, base) == -1) 3414 return (-1); 3415 if (base[0] == '/') 3416 return (0); 3417 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3418 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3419 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3420 return (-1); 3421 strcpy(base, base_rel); 3422 return (0); 3423 } 3424 3425 static void 3426 linkmap_add(Obj_Entry *obj) 3427 { 3428 struct link_map *l = &obj->linkmap; 3429 struct link_map *prev; 3430 3431 obj->linkmap.l_name = obj->path; 3432 obj->linkmap.l_addr = obj->mapbase; 3433 obj->linkmap.l_ld = obj->dynamic; 3434 #ifdef __mips__ 3435 /* GDB needs load offset on MIPS to use the symbols */ 3436 obj->linkmap.l_offs = obj->relocbase; 3437 #endif 3438 3439 if (r_debug.r_map == NULL) { 3440 r_debug.r_map = l; 3441 return; 3442 } 3443 3444 /* 3445 * Scan to the end of the list, but not past the entry for the 3446 * dynamic linker, which we want to keep at the very end. 3447 */ 3448 for (prev = r_debug.r_map; 3449 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3450 prev = prev->l_next) 3451 ; 3452 3453 /* Link in the new entry. */ 3454 l->l_prev = prev; 3455 l->l_next = prev->l_next; 3456 if (l->l_next != NULL) 3457 l->l_next->l_prev = l; 3458 prev->l_next = l; 3459 } 3460 3461 static void 3462 linkmap_delete(Obj_Entry *obj) 3463 { 3464 struct link_map *l = &obj->linkmap; 3465 3466 if (l->l_prev == NULL) { 3467 if ((r_debug.r_map = l->l_next) != NULL) 3468 l->l_next->l_prev = NULL; 3469 return; 3470 } 3471 3472 if ((l->l_prev->l_next = l->l_next) != NULL) 3473 l->l_next->l_prev = l->l_prev; 3474 } 3475 3476 /* 3477 * Function for the debugger to set a breakpoint on to gain control. 3478 * 3479 * The two parameters allow the debugger to easily find and determine 3480 * what the runtime loader is doing and to whom it is doing it. 3481 * 3482 * When the loadhook trap is hit (r_debug_state, set at program 3483 * initialization), the arguments can be found on the stack: 3484 * 3485 * +8 struct link_map *m 3486 * +4 struct r_debug *rd 3487 * +0 RetAddr 3488 */ 3489 void 3490 r_debug_state(struct r_debug* rd, struct link_map *m) 3491 { 3492 /* 3493 * The following is a hack to force the compiler to emit calls to 3494 * this function, even when optimizing. If the function is empty, 3495 * the compiler is not obliged to emit any code for calls to it, 3496 * even when marked __noinline. However, gdb depends on those 3497 * calls being made. 3498 */ 3499 __asm __volatile("" : : : "memory"); 3500 } 3501 3502 /* 3503 * Get address of the pointer variable in the main program. 3504 * Prefer non-weak symbol over the weak one. 3505 */ 3506 static const void ** 3507 get_program_var_addr(const char *name, RtldLockState *lockstate) 3508 { 3509 SymLook req; 3510 DoneList donelist; 3511 3512 symlook_init(&req, name); 3513 req.lockstate = lockstate; 3514 donelist_init(&donelist); 3515 if (symlook_global(&req, &donelist) != 0) 3516 return (NULL); 3517 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3518 return ((const void **)make_function_pointer(req.sym_out, 3519 req.defobj_out)); 3520 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3521 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3522 else 3523 return ((const void **)(req.defobj_out->relocbase + 3524 req.sym_out->st_value)); 3525 } 3526 3527 /* 3528 * Set a pointer variable in the main program to the given value. This 3529 * is used to set key variables such as "environ" before any of the 3530 * init functions are called. 3531 */ 3532 static void 3533 set_program_var(const char *name, const void *value) 3534 { 3535 const void **addr; 3536 3537 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3538 dbg("\"%s\": *%p <-- %p", name, addr, value); 3539 *addr = value; 3540 } 3541 } 3542 3543 /* 3544 * Search the global objects, including dependencies and main object, 3545 * for the given symbol. 3546 */ 3547 static int 3548 symlook_global(SymLook *req, DoneList *donelist) 3549 { 3550 SymLook req1; 3551 const Objlist_Entry *elm; 3552 int res; 3553 3554 symlook_init_from_req(&req1, req); 3555 3556 /* Search all objects loaded at program start up. */ 3557 if (req->defobj_out == NULL || 3558 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3559 res = symlook_list(&req1, &list_main, donelist); 3560 if (res == 0 && (req->defobj_out == NULL || 3561 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3562 req->sym_out = req1.sym_out; 3563 req->defobj_out = req1.defobj_out; 3564 assert(req->defobj_out != NULL); 3565 } 3566 } 3567 3568 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3569 STAILQ_FOREACH(elm, &list_global, link) { 3570 if (req->defobj_out != NULL && 3571 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3572 break; 3573 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3574 if (res == 0 && (req->defobj_out == NULL || 3575 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3576 req->sym_out = req1.sym_out; 3577 req->defobj_out = req1.defobj_out; 3578 assert(req->defobj_out != NULL); 3579 } 3580 } 3581 3582 return (req->sym_out != NULL ? 0 : ESRCH); 3583 } 3584 3585 /* 3586 * Given a symbol name in a referencing object, find the corresponding 3587 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3588 * no definition was found. Returns a pointer to the Obj_Entry of the 3589 * defining object via the reference parameter DEFOBJ_OUT. 3590 */ 3591 static int 3592 symlook_default(SymLook *req, const Obj_Entry *refobj) 3593 { 3594 DoneList donelist; 3595 const Objlist_Entry *elm; 3596 SymLook req1; 3597 int res; 3598 3599 donelist_init(&donelist); 3600 symlook_init_from_req(&req1, req); 3601 3602 /* Look first in the referencing object if linked symbolically. */ 3603 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3604 res = symlook_obj(&req1, refobj); 3605 if (res == 0) { 3606 req->sym_out = req1.sym_out; 3607 req->defobj_out = req1.defobj_out; 3608 assert(req->defobj_out != NULL); 3609 } 3610 } 3611 3612 symlook_global(req, &donelist); 3613 3614 /* Search all dlopened DAGs containing the referencing object. */ 3615 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3616 if (req->sym_out != NULL && 3617 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3618 break; 3619 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3620 if (res == 0 && (req->sym_out == NULL || 3621 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3622 req->sym_out = req1.sym_out; 3623 req->defobj_out = req1.defobj_out; 3624 assert(req->defobj_out != NULL); 3625 } 3626 } 3627 3628 /* 3629 * Search the dynamic linker itself, and possibly resolve the 3630 * symbol from there. This is how the application links to 3631 * dynamic linker services such as dlopen. 3632 */ 3633 if (req->sym_out == NULL || 3634 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3635 res = symlook_obj(&req1, &obj_rtld); 3636 if (res == 0) { 3637 req->sym_out = req1.sym_out; 3638 req->defobj_out = req1.defobj_out; 3639 assert(req->defobj_out != NULL); 3640 } 3641 } 3642 3643 return (req->sym_out != NULL ? 0 : ESRCH); 3644 } 3645 3646 static int 3647 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3648 { 3649 const Elf_Sym *def; 3650 const Obj_Entry *defobj; 3651 const Objlist_Entry *elm; 3652 SymLook req1; 3653 int res; 3654 3655 def = NULL; 3656 defobj = NULL; 3657 STAILQ_FOREACH(elm, objlist, link) { 3658 if (donelist_check(dlp, elm->obj)) 3659 continue; 3660 symlook_init_from_req(&req1, req); 3661 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3662 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3663 def = req1.sym_out; 3664 defobj = req1.defobj_out; 3665 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3666 break; 3667 } 3668 } 3669 } 3670 if (def != NULL) { 3671 req->sym_out = def; 3672 req->defobj_out = defobj; 3673 return (0); 3674 } 3675 return (ESRCH); 3676 } 3677 3678 /* 3679 * Search the chain of DAGS cointed to by the given Needed_Entry 3680 * for a symbol of the given name. Each DAG is scanned completely 3681 * before advancing to the next one. Returns a pointer to the symbol, 3682 * or NULL if no definition was found. 3683 */ 3684 static int 3685 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3686 { 3687 const Elf_Sym *def; 3688 const Needed_Entry *n; 3689 const Obj_Entry *defobj; 3690 SymLook req1; 3691 int res; 3692 3693 def = NULL; 3694 defobj = NULL; 3695 symlook_init_from_req(&req1, req); 3696 for (n = needed; n != NULL; n = n->next) { 3697 if (n->obj == NULL || 3698 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3699 continue; 3700 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3701 def = req1.sym_out; 3702 defobj = req1.defobj_out; 3703 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3704 break; 3705 } 3706 } 3707 if (def != NULL) { 3708 req->sym_out = def; 3709 req->defobj_out = defobj; 3710 return (0); 3711 } 3712 return (ESRCH); 3713 } 3714 3715 /* 3716 * Search the symbol table of a single shared object for a symbol of 3717 * the given name and version, if requested. Returns a pointer to the 3718 * symbol, or NULL if no definition was found. If the object is 3719 * filter, return filtered symbol from filtee. 3720 * 3721 * The symbol's hash value is passed in for efficiency reasons; that 3722 * eliminates many recomputations of the hash value. 3723 */ 3724 int 3725 symlook_obj(SymLook *req, const Obj_Entry *obj) 3726 { 3727 DoneList donelist; 3728 SymLook req1; 3729 int flags, res, mres; 3730 3731 /* 3732 * If there is at least one valid hash at this point, we prefer to 3733 * use the faster GNU version if available. 3734 */ 3735 if (obj->valid_hash_gnu) 3736 mres = symlook_obj1_gnu(req, obj); 3737 else if (obj->valid_hash_sysv) 3738 mres = symlook_obj1_sysv(req, obj); 3739 else 3740 return (EINVAL); 3741 3742 if (mres == 0) { 3743 if (obj->needed_filtees != NULL) { 3744 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3745 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3746 donelist_init(&donelist); 3747 symlook_init_from_req(&req1, req); 3748 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3749 if (res == 0) { 3750 req->sym_out = req1.sym_out; 3751 req->defobj_out = req1.defobj_out; 3752 } 3753 return (res); 3754 } 3755 if (obj->needed_aux_filtees != NULL) { 3756 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3757 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3758 donelist_init(&donelist); 3759 symlook_init_from_req(&req1, req); 3760 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3761 if (res == 0) { 3762 req->sym_out = req1.sym_out; 3763 req->defobj_out = req1.defobj_out; 3764 return (res); 3765 } 3766 } 3767 } 3768 return (mres); 3769 } 3770 3771 /* Symbol match routine common to both hash functions */ 3772 static bool 3773 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3774 const unsigned long symnum) 3775 { 3776 Elf_Versym verndx; 3777 const Elf_Sym *symp; 3778 const char *strp; 3779 3780 symp = obj->symtab + symnum; 3781 strp = obj->strtab + symp->st_name; 3782 3783 switch (ELF_ST_TYPE(symp->st_info)) { 3784 case STT_FUNC: 3785 case STT_NOTYPE: 3786 case STT_OBJECT: 3787 case STT_COMMON: 3788 case STT_GNU_IFUNC: 3789 if (symp->st_value == 0) 3790 return (false); 3791 /* fallthrough */ 3792 case STT_TLS: 3793 if (symp->st_shndx != SHN_UNDEF) 3794 break; 3795 #ifndef __mips__ 3796 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3797 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3798 break; 3799 /* fallthrough */ 3800 #endif 3801 default: 3802 return (false); 3803 } 3804 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3805 return (false); 3806 3807 if (req->ventry == NULL) { 3808 if (obj->versyms != NULL) { 3809 verndx = VER_NDX(obj->versyms[symnum]); 3810 if (verndx > obj->vernum) { 3811 _rtld_error( 3812 "%s: symbol %s references wrong version %d", 3813 obj->path, obj->strtab + symnum, verndx); 3814 return (false); 3815 } 3816 /* 3817 * If we are not called from dlsym (i.e. this 3818 * is a normal relocation from unversioned 3819 * binary), accept the symbol immediately if 3820 * it happens to have first version after this 3821 * shared object became versioned. Otherwise, 3822 * if symbol is versioned and not hidden, 3823 * remember it. If it is the only symbol with 3824 * this name exported by the shared object, it 3825 * will be returned as a match by the calling 3826 * function. If symbol is global (verndx < 2) 3827 * accept it unconditionally. 3828 */ 3829 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3830 verndx == VER_NDX_GIVEN) { 3831 result->sym_out = symp; 3832 return (true); 3833 } 3834 else if (verndx >= VER_NDX_GIVEN) { 3835 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3836 == 0) { 3837 if (result->vsymp == NULL) 3838 result->vsymp = symp; 3839 result->vcount++; 3840 } 3841 return (false); 3842 } 3843 } 3844 result->sym_out = symp; 3845 return (true); 3846 } 3847 if (obj->versyms == NULL) { 3848 if (object_match_name(obj, req->ventry->name)) { 3849 _rtld_error("%s: object %s should provide version %s " 3850 "for symbol %s", obj_rtld.path, obj->path, 3851 req->ventry->name, obj->strtab + symnum); 3852 return (false); 3853 } 3854 } else { 3855 verndx = VER_NDX(obj->versyms[symnum]); 3856 if (verndx > obj->vernum) { 3857 _rtld_error("%s: symbol %s references wrong version %d", 3858 obj->path, obj->strtab + symnum, verndx); 3859 return (false); 3860 } 3861 if (obj->vertab[verndx].hash != req->ventry->hash || 3862 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3863 /* 3864 * Version does not match. Look if this is a 3865 * global symbol and if it is not hidden. If 3866 * global symbol (verndx < 2) is available, 3867 * use it. Do not return symbol if we are 3868 * called by dlvsym, because dlvsym looks for 3869 * a specific version and default one is not 3870 * what dlvsym wants. 3871 */ 3872 if ((req->flags & SYMLOOK_DLSYM) || 3873 (verndx >= VER_NDX_GIVEN) || 3874 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3875 return (false); 3876 } 3877 } 3878 result->sym_out = symp; 3879 return (true); 3880 } 3881 3882 /* 3883 * Search for symbol using SysV hash function. 3884 * obj->buckets is known not to be NULL at this point; the test for this was 3885 * performed with the obj->valid_hash_sysv assignment. 3886 */ 3887 static int 3888 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3889 { 3890 unsigned long symnum; 3891 Sym_Match_Result matchres; 3892 3893 matchres.sym_out = NULL; 3894 matchres.vsymp = NULL; 3895 matchres.vcount = 0; 3896 3897 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3898 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3899 if (symnum >= obj->nchains) 3900 return (ESRCH); /* Bad object */ 3901 3902 if (matched_symbol(req, obj, &matchres, symnum)) { 3903 req->sym_out = matchres.sym_out; 3904 req->defobj_out = obj; 3905 return (0); 3906 } 3907 } 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 /* Search for symbol using GNU hash function */ 3917 static int 3918 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3919 { 3920 Elf_Addr bloom_word; 3921 const Elf32_Word *hashval; 3922 Elf32_Word bucket; 3923 Sym_Match_Result matchres; 3924 unsigned int h1, h2; 3925 unsigned long symnum; 3926 3927 matchres.sym_out = NULL; 3928 matchres.vsymp = NULL; 3929 matchres.vcount = 0; 3930 3931 /* Pick right bitmask word from Bloom filter array */ 3932 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3933 obj->maskwords_bm_gnu]; 3934 3935 /* Calculate modulus word size of gnu hash and its derivative */ 3936 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3937 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3938 3939 /* Filter out the "definitely not in set" queries */ 3940 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3941 return (ESRCH); 3942 3943 /* Locate hash chain and corresponding value element*/ 3944 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3945 if (bucket == 0) 3946 return (ESRCH); 3947 hashval = &obj->chain_zero_gnu[bucket]; 3948 do { 3949 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3950 symnum = hashval - obj->chain_zero_gnu; 3951 if (matched_symbol(req, obj, &matchres, symnum)) { 3952 req->sym_out = matchres.sym_out; 3953 req->defobj_out = obj; 3954 return (0); 3955 } 3956 } 3957 } while ((*hashval++ & 1) == 0); 3958 if (matchres.vcount == 1) { 3959 req->sym_out = matchres.vsymp; 3960 req->defobj_out = obj; 3961 return (0); 3962 } 3963 return (ESRCH); 3964 } 3965 3966 static void 3967 trace_loaded_objects(Obj_Entry *obj) 3968 { 3969 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3970 int c; 3971 3972 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3973 main_local = ""; 3974 3975 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3976 fmt1 = "\t%o => %p (%x)\n"; 3977 3978 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3979 fmt2 = "\t%o (%x)\n"; 3980 3981 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3982 3983 for (; obj; obj = obj->next) { 3984 Needed_Entry *needed; 3985 char *name, *path; 3986 bool is_lib; 3987 3988 if (list_containers && obj->needed != NULL) 3989 rtld_printf("%s:\n", obj->path); 3990 for (needed = obj->needed; needed; needed = needed->next) { 3991 if (needed->obj != NULL) { 3992 if (needed->obj->traced && !list_containers) 3993 continue; 3994 needed->obj->traced = true; 3995 path = needed->obj->path; 3996 } else 3997 path = "not found"; 3998 3999 name = (char *)obj->strtab + needed->name; 4000 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4001 4002 fmt = is_lib ? fmt1 : fmt2; 4003 while ((c = *fmt++) != '\0') { 4004 switch (c) { 4005 default: 4006 rtld_putchar(c); 4007 continue; 4008 case '\\': 4009 switch (c = *fmt) { 4010 case '\0': 4011 continue; 4012 case 'n': 4013 rtld_putchar('\n'); 4014 break; 4015 case 't': 4016 rtld_putchar('\t'); 4017 break; 4018 } 4019 break; 4020 case '%': 4021 switch (c = *fmt) { 4022 case '\0': 4023 continue; 4024 case '%': 4025 default: 4026 rtld_putchar(c); 4027 break; 4028 case 'A': 4029 rtld_putstr(main_local); 4030 break; 4031 case 'a': 4032 rtld_putstr(obj_main->path); 4033 break; 4034 case 'o': 4035 rtld_putstr(name); 4036 break; 4037 #if 0 4038 case 'm': 4039 rtld_printf("%d", sodp->sod_major); 4040 break; 4041 case 'n': 4042 rtld_printf("%d", sodp->sod_minor); 4043 break; 4044 #endif 4045 case 'p': 4046 rtld_putstr(path); 4047 break; 4048 case 'x': 4049 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4050 0); 4051 break; 4052 } 4053 break; 4054 } 4055 ++fmt; 4056 } 4057 } 4058 } 4059 } 4060 4061 /* 4062 * Unload a dlopened object and its dependencies from memory and from 4063 * our data structures. It is assumed that the DAG rooted in the 4064 * object has already been unreferenced, and that the object has a 4065 * reference count of 0. 4066 */ 4067 static void 4068 unload_object(Obj_Entry *root) 4069 { 4070 Obj_Entry *obj; 4071 Obj_Entry **linkp; 4072 4073 assert(root->refcount == 0); 4074 4075 /* 4076 * Pass over the DAG removing unreferenced objects from 4077 * appropriate lists. 4078 */ 4079 unlink_object(root); 4080 4081 /* Unmap all objects that are no longer referenced. */ 4082 linkp = &obj_list->next; 4083 while ((obj = *linkp) != NULL) { 4084 if (obj->refcount == 0) { 4085 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4086 obj->path); 4087 dbg("unloading \"%s\"", obj->path); 4088 unload_filtees(root); 4089 munmap(obj->mapbase, obj->mapsize); 4090 linkmap_delete(obj); 4091 *linkp = obj->next; 4092 obj_count--; 4093 obj_free(obj); 4094 } else 4095 linkp = &obj->next; 4096 } 4097 obj_tail = linkp; 4098 } 4099 4100 static void 4101 unlink_object(Obj_Entry *root) 4102 { 4103 Objlist_Entry *elm; 4104 4105 if (root->refcount == 0) { 4106 /* Remove the object from the RTLD_GLOBAL list. */ 4107 objlist_remove(&list_global, root); 4108 4109 /* Remove the object from all objects' DAG lists. */ 4110 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4111 objlist_remove(&elm->obj->dldags, root); 4112 if (elm->obj != root) 4113 unlink_object(elm->obj); 4114 } 4115 } 4116 } 4117 4118 static void 4119 ref_dag(Obj_Entry *root) 4120 { 4121 Objlist_Entry *elm; 4122 4123 assert(root->dag_inited); 4124 STAILQ_FOREACH(elm, &root->dagmembers, link) 4125 elm->obj->refcount++; 4126 } 4127 4128 static void 4129 unref_dag(Obj_Entry *root) 4130 { 4131 Objlist_Entry *elm; 4132 4133 assert(root->dag_inited); 4134 STAILQ_FOREACH(elm, &root->dagmembers, link) 4135 elm->obj->refcount--; 4136 } 4137 4138 /* 4139 * Common code for MD __tls_get_addr(). 4140 */ 4141 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4142 static void * 4143 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4144 { 4145 Elf_Addr *newdtv, *dtv; 4146 RtldLockState lockstate; 4147 int to_copy; 4148 4149 dtv = *dtvp; 4150 /* Check dtv generation in case new modules have arrived */ 4151 if (dtv[0] != tls_dtv_generation) { 4152 wlock_acquire(rtld_bind_lock, &lockstate); 4153 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4154 to_copy = dtv[1]; 4155 if (to_copy > tls_max_index) 4156 to_copy = tls_max_index; 4157 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4158 newdtv[0] = tls_dtv_generation; 4159 newdtv[1] = tls_max_index; 4160 free(dtv); 4161 lock_release(rtld_bind_lock, &lockstate); 4162 dtv = *dtvp = newdtv; 4163 } 4164 4165 /* Dynamically allocate module TLS if necessary */ 4166 if (dtv[index + 1] == 0) { 4167 /* Signal safe, wlock will block out signals. */ 4168 wlock_acquire(rtld_bind_lock, &lockstate); 4169 if (!dtv[index + 1]) 4170 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4171 lock_release(rtld_bind_lock, &lockstate); 4172 } 4173 return ((void *)(dtv[index + 1] + offset)); 4174 } 4175 4176 void * 4177 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4178 { 4179 Elf_Addr *dtv; 4180 4181 dtv = *dtvp; 4182 /* Check dtv generation in case new modules have arrived */ 4183 if (__predict_true(dtv[0] == tls_dtv_generation && 4184 dtv[index + 1] != 0)) 4185 return ((void *)(dtv[index + 1] + offset)); 4186 return (tls_get_addr_slow(dtvp, index, offset)); 4187 } 4188 4189 #if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4190 4191 /* 4192 * Allocate Static TLS using the Variant I method. 4193 */ 4194 void * 4195 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4196 { 4197 Obj_Entry *obj; 4198 char *tcb; 4199 Elf_Addr **tls; 4200 Elf_Addr *dtv; 4201 Elf_Addr addr; 4202 int i; 4203 4204 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4205 return (oldtcb); 4206 4207 assert(tcbsize >= TLS_TCB_SIZE); 4208 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4209 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4210 4211 if (oldtcb != NULL) { 4212 memcpy(tls, oldtcb, tls_static_space); 4213 free(oldtcb); 4214 4215 /* Adjust the DTV. */ 4216 dtv = tls[0]; 4217 for (i = 0; i < dtv[1]; i++) { 4218 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4219 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4220 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4221 } 4222 } 4223 } else { 4224 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4225 tls[0] = dtv; 4226 dtv[0] = tls_dtv_generation; 4227 dtv[1] = tls_max_index; 4228 4229 for (obj = objs; obj; obj = obj->next) { 4230 if (obj->tlsoffset > 0) { 4231 addr = (Elf_Addr)tls + obj->tlsoffset; 4232 if (obj->tlsinitsize > 0) 4233 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4234 if (obj->tlssize > obj->tlsinitsize) 4235 memset((void*) (addr + obj->tlsinitsize), 0, 4236 obj->tlssize - obj->tlsinitsize); 4237 dtv[obj->tlsindex + 1] = addr; 4238 } 4239 } 4240 } 4241 4242 return (tcb); 4243 } 4244 4245 void 4246 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4247 { 4248 Elf_Addr *dtv; 4249 Elf_Addr tlsstart, tlsend; 4250 int dtvsize, i; 4251 4252 assert(tcbsize >= TLS_TCB_SIZE); 4253 4254 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4255 tlsend = tlsstart + tls_static_space; 4256 4257 dtv = *(Elf_Addr **)tlsstart; 4258 dtvsize = dtv[1]; 4259 for (i = 0; i < dtvsize; i++) { 4260 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4261 free((void*)dtv[i+2]); 4262 } 4263 } 4264 free(dtv); 4265 free(tcb); 4266 } 4267 4268 #endif 4269 4270 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4271 4272 /* 4273 * Allocate Static TLS using the Variant II method. 4274 */ 4275 void * 4276 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4277 { 4278 Obj_Entry *obj; 4279 size_t size; 4280 char *tls; 4281 Elf_Addr *dtv, *olddtv; 4282 Elf_Addr segbase, oldsegbase, addr; 4283 int i; 4284 4285 size = round(tls_static_space, tcbalign); 4286 4287 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4288 tls = xcalloc(1, size + tcbsize); 4289 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4290 4291 segbase = (Elf_Addr)(tls + size); 4292 ((Elf_Addr*)segbase)[0] = segbase; 4293 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4294 4295 dtv[0] = tls_dtv_generation; 4296 dtv[1] = tls_max_index; 4297 4298 if (oldtls) { 4299 /* 4300 * Copy the static TLS block over whole. 4301 */ 4302 oldsegbase = (Elf_Addr) oldtls; 4303 memcpy((void *)(segbase - tls_static_space), 4304 (const void *)(oldsegbase - tls_static_space), 4305 tls_static_space); 4306 4307 /* 4308 * If any dynamic TLS blocks have been created tls_get_addr(), 4309 * move them over. 4310 */ 4311 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4312 for (i = 0; i < olddtv[1]; i++) { 4313 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4314 dtv[i+2] = olddtv[i+2]; 4315 olddtv[i+2] = 0; 4316 } 4317 } 4318 4319 /* 4320 * We assume that this block was the one we created with 4321 * allocate_initial_tls(). 4322 */ 4323 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4324 } else { 4325 for (obj = objs; obj; obj = obj->next) { 4326 if (obj->tlsoffset) { 4327 addr = segbase - obj->tlsoffset; 4328 memset((void*) (addr + obj->tlsinitsize), 4329 0, obj->tlssize - obj->tlsinitsize); 4330 if (obj->tlsinit) 4331 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4332 dtv[obj->tlsindex + 1] = addr; 4333 } 4334 } 4335 } 4336 4337 return (void*) segbase; 4338 } 4339 4340 void 4341 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4342 { 4343 size_t size; 4344 Elf_Addr* dtv; 4345 int dtvsize, i; 4346 Elf_Addr tlsstart, tlsend; 4347 4348 /* 4349 * Figure out the size of the initial TLS block so that we can 4350 * find stuff which ___tls_get_addr() allocated dynamically. 4351 */ 4352 size = round(tls_static_space, tcbalign); 4353 4354 dtv = ((Elf_Addr**)tls)[1]; 4355 dtvsize = dtv[1]; 4356 tlsend = (Elf_Addr) tls; 4357 tlsstart = tlsend - size; 4358 for (i = 0; i < dtvsize; i++) { 4359 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) { 4360 free((void*) dtv[i+2]); 4361 } 4362 } 4363 4364 free((void*) tlsstart); 4365 free((void*) dtv); 4366 } 4367 4368 #endif 4369 4370 /* 4371 * Allocate TLS block for module with given index. 4372 */ 4373 void * 4374 allocate_module_tls(int index) 4375 { 4376 Obj_Entry* obj; 4377 char* p; 4378 4379 for (obj = obj_list; obj; obj = obj->next) { 4380 if (obj->tlsindex == index) 4381 break; 4382 } 4383 if (!obj) { 4384 _rtld_error("Can't find module with TLS index %d", index); 4385 die(); 4386 } 4387 4388 p = malloc(obj->tlssize); 4389 if (p == NULL) { 4390 _rtld_error("Cannot allocate TLS block for index %d", index); 4391 die(); 4392 } 4393 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4394 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4395 4396 return p; 4397 } 4398 4399 bool 4400 allocate_tls_offset(Obj_Entry *obj) 4401 { 4402 size_t off; 4403 4404 if (obj->tls_done) 4405 return true; 4406 4407 if (obj->tlssize == 0) { 4408 obj->tls_done = true; 4409 return true; 4410 } 4411 4412 if (obj->tlsindex == 1) 4413 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4414 else 4415 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4416 obj->tlssize, obj->tlsalign); 4417 4418 /* 4419 * If we have already fixed the size of the static TLS block, we 4420 * must stay within that size. When allocating the static TLS, we 4421 * leave a small amount of space spare to be used for dynamically 4422 * loading modules which use static TLS. 4423 */ 4424 if (tls_static_space) { 4425 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4426 return false; 4427 } 4428 4429 tls_last_offset = obj->tlsoffset = off; 4430 tls_last_size = obj->tlssize; 4431 obj->tls_done = true; 4432 4433 return true; 4434 } 4435 4436 void 4437 free_tls_offset(Obj_Entry *obj) 4438 { 4439 4440 /* 4441 * If we were the last thing to allocate out of the static TLS 4442 * block, we give our space back to the 'allocator'. This is a 4443 * simplistic workaround to allow libGL.so.1 to be loaded and 4444 * unloaded multiple times. 4445 */ 4446 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4447 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4448 tls_last_offset -= obj->tlssize; 4449 tls_last_size = 0; 4450 } 4451 } 4452 4453 void * 4454 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4455 { 4456 void *ret; 4457 RtldLockState lockstate; 4458 4459 wlock_acquire(rtld_bind_lock, &lockstate); 4460 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4461 lock_release(rtld_bind_lock, &lockstate); 4462 return (ret); 4463 } 4464 4465 void 4466 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4467 { 4468 RtldLockState lockstate; 4469 4470 wlock_acquire(rtld_bind_lock, &lockstate); 4471 free_tls(tcb, tcbsize, tcbalign); 4472 lock_release(rtld_bind_lock, &lockstate); 4473 } 4474 4475 static void 4476 object_add_name(Obj_Entry *obj, const char *name) 4477 { 4478 Name_Entry *entry; 4479 size_t len; 4480 4481 len = strlen(name); 4482 entry = malloc(sizeof(Name_Entry) + len); 4483 4484 if (entry != NULL) { 4485 strcpy(entry->name, name); 4486 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4487 } 4488 } 4489 4490 static int 4491 object_match_name(const Obj_Entry *obj, const char *name) 4492 { 4493 Name_Entry *entry; 4494 4495 STAILQ_FOREACH(entry, &obj->names, link) { 4496 if (strcmp(name, entry->name) == 0) 4497 return (1); 4498 } 4499 return (0); 4500 } 4501 4502 static Obj_Entry * 4503 locate_dependency(const Obj_Entry *obj, const char *name) 4504 { 4505 const Objlist_Entry *entry; 4506 const Needed_Entry *needed; 4507 4508 STAILQ_FOREACH(entry, &list_main, link) { 4509 if (object_match_name(entry->obj, name)) 4510 return entry->obj; 4511 } 4512 4513 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4514 if (strcmp(obj->strtab + needed->name, name) == 0 || 4515 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4516 /* 4517 * If there is DT_NEEDED for the name we are looking for, 4518 * we are all set. Note that object might not be found if 4519 * dependency was not loaded yet, so the function can 4520 * return NULL here. This is expected and handled 4521 * properly by the caller. 4522 */ 4523 return (needed->obj); 4524 } 4525 } 4526 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4527 obj->path, name); 4528 die(); 4529 } 4530 4531 static int 4532 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4533 const Elf_Vernaux *vna) 4534 { 4535 const Elf_Verdef *vd; 4536 const char *vername; 4537 4538 vername = refobj->strtab + vna->vna_name; 4539 vd = depobj->verdef; 4540 if (vd == NULL) { 4541 _rtld_error("%s: version %s required by %s not defined", 4542 depobj->path, vername, refobj->path); 4543 return (-1); 4544 } 4545 for (;;) { 4546 if (vd->vd_version != VER_DEF_CURRENT) { 4547 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4548 depobj->path, vd->vd_version); 4549 return (-1); 4550 } 4551 if (vna->vna_hash == vd->vd_hash) { 4552 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4553 ((char *)vd + vd->vd_aux); 4554 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4555 return (0); 4556 } 4557 if (vd->vd_next == 0) 4558 break; 4559 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4560 } 4561 if (vna->vna_flags & VER_FLG_WEAK) 4562 return (0); 4563 _rtld_error("%s: version %s required by %s not found", 4564 depobj->path, vername, refobj->path); 4565 return (-1); 4566 } 4567 4568 static int 4569 rtld_verify_object_versions(Obj_Entry *obj) 4570 { 4571 const Elf_Verneed *vn; 4572 const Elf_Verdef *vd; 4573 const Elf_Verdaux *vda; 4574 const Elf_Vernaux *vna; 4575 const Obj_Entry *depobj; 4576 int maxvernum, vernum; 4577 4578 if (obj->ver_checked) 4579 return (0); 4580 obj->ver_checked = true; 4581 4582 maxvernum = 0; 4583 /* 4584 * Walk over defined and required version records and figure out 4585 * max index used by any of them. Do very basic sanity checking 4586 * while there. 4587 */ 4588 vn = obj->verneed; 4589 while (vn != NULL) { 4590 if (vn->vn_version != VER_NEED_CURRENT) { 4591 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4592 obj->path, vn->vn_version); 4593 return (-1); 4594 } 4595 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4596 for (;;) { 4597 vernum = VER_NEED_IDX(vna->vna_other); 4598 if (vernum > maxvernum) 4599 maxvernum = vernum; 4600 if (vna->vna_next == 0) 4601 break; 4602 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4603 } 4604 if (vn->vn_next == 0) 4605 break; 4606 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4607 } 4608 4609 vd = obj->verdef; 4610 while (vd != NULL) { 4611 if (vd->vd_version != VER_DEF_CURRENT) { 4612 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4613 obj->path, vd->vd_version); 4614 return (-1); 4615 } 4616 vernum = VER_DEF_IDX(vd->vd_ndx); 4617 if (vernum > maxvernum) 4618 maxvernum = vernum; 4619 if (vd->vd_next == 0) 4620 break; 4621 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4622 } 4623 4624 if (maxvernum == 0) 4625 return (0); 4626 4627 /* 4628 * Store version information in array indexable by version index. 4629 * Verify that object version requirements are satisfied along the 4630 * way. 4631 */ 4632 obj->vernum = maxvernum + 1; 4633 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4634 4635 vd = obj->verdef; 4636 while (vd != NULL) { 4637 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4638 vernum = VER_DEF_IDX(vd->vd_ndx); 4639 assert(vernum <= maxvernum); 4640 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4641 obj->vertab[vernum].hash = vd->vd_hash; 4642 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4643 obj->vertab[vernum].file = NULL; 4644 obj->vertab[vernum].flags = 0; 4645 } 4646 if (vd->vd_next == 0) 4647 break; 4648 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4649 } 4650 4651 vn = obj->verneed; 4652 while (vn != NULL) { 4653 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4654 if (depobj == NULL) 4655 return (-1); 4656 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4657 for (;;) { 4658 if (check_object_provided_version(obj, depobj, vna)) 4659 return (-1); 4660 vernum = VER_NEED_IDX(vna->vna_other); 4661 assert(vernum <= maxvernum); 4662 obj->vertab[vernum].hash = vna->vna_hash; 4663 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4664 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4665 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4666 VER_INFO_HIDDEN : 0; 4667 if (vna->vna_next == 0) 4668 break; 4669 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4670 } 4671 if (vn->vn_next == 0) 4672 break; 4673 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4674 } 4675 return 0; 4676 } 4677 4678 static int 4679 rtld_verify_versions(const Objlist *objlist) 4680 { 4681 Objlist_Entry *entry; 4682 int rc; 4683 4684 rc = 0; 4685 STAILQ_FOREACH(entry, objlist, link) { 4686 /* 4687 * Skip dummy objects or objects that have their version requirements 4688 * already checked. 4689 */ 4690 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4691 continue; 4692 if (rtld_verify_object_versions(entry->obj) == -1) { 4693 rc = -1; 4694 if (ld_tracing == NULL) 4695 break; 4696 } 4697 } 4698 if (rc == 0 || ld_tracing != NULL) 4699 rc = rtld_verify_object_versions(&obj_rtld); 4700 return rc; 4701 } 4702 4703 const Ver_Entry * 4704 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4705 { 4706 Elf_Versym vernum; 4707 4708 if (obj->vertab) { 4709 vernum = VER_NDX(obj->versyms[symnum]); 4710 if (vernum >= obj->vernum) { 4711 _rtld_error("%s: symbol %s has wrong verneed value %d", 4712 obj->path, obj->strtab + symnum, vernum); 4713 } else if (obj->vertab[vernum].hash != 0) { 4714 return &obj->vertab[vernum]; 4715 } 4716 } 4717 return NULL; 4718 } 4719 4720 int 4721 _rtld_get_stack_prot(void) 4722 { 4723 4724 return (stack_prot); 4725 } 4726 4727 static void 4728 map_stacks_exec(RtldLockState *lockstate) 4729 { 4730 void (*thr_map_stacks_exec)(void); 4731 4732 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4733 return; 4734 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4735 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4736 if (thr_map_stacks_exec != NULL) { 4737 stack_prot |= PROT_EXEC; 4738 thr_map_stacks_exec(); 4739 } 4740 } 4741 4742 void 4743 symlook_init(SymLook *dst, const char *name) 4744 { 4745 4746 bzero(dst, sizeof(*dst)); 4747 dst->name = name; 4748 dst->hash = elf_hash(name); 4749 dst->hash_gnu = gnu_hash(name); 4750 } 4751 4752 static void 4753 symlook_init_from_req(SymLook *dst, const SymLook *src) 4754 { 4755 4756 dst->name = src->name; 4757 dst->hash = src->hash; 4758 dst->hash_gnu = src->hash_gnu; 4759 dst->ventry = src->ventry; 4760 dst->flags = src->flags; 4761 dst->defobj_out = NULL; 4762 dst->sym_out = NULL; 4763 dst->lockstate = src->lockstate; 4764 } 4765 4766 /* 4767 * Overrides for libc_pic-provided functions. 4768 */ 4769 4770 int 4771 __getosreldate(void) 4772 { 4773 size_t len; 4774 int oid[2]; 4775 int error, osrel; 4776 4777 if (osreldate != 0) 4778 return (osreldate); 4779 4780 oid[0] = CTL_KERN; 4781 oid[1] = KERN_OSRELDATE; 4782 osrel = 0; 4783 len = sizeof(osrel); 4784 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4785 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4786 osreldate = osrel; 4787 return (osreldate); 4788 } 4789 4790 void 4791 exit(int status) 4792 { 4793 4794 _exit(status); 4795 } 4796 4797 void (*__cleanup)(void); 4798 int __isthreaded = 0; 4799 int _thread_autoinit_dummy_decl = 1; 4800 4801 /* 4802 * No unresolved symbols for rtld. 4803 */ 4804 void 4805 __pthread_cxa_finalize(struct dl_phdr_info *a) 4806 { 4807 } 4808 4809 void 4810 __stack_chk_fail(void) 4811 { 4812 4813 _rtld_error("stack overflow detected; terminated"); 4814 die(); 4815 } 4816 __weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4817 4818 void 4819 __chk_fail(void) 4820 { 4821 4822 _rtld_error("buffer overflow detected; terminated"); 4823 die(); 4824 } 4825 4826 const char * 4827 rtld_strerror(int errnum) 4828 { 4829 4830 if (errnum < 0 || errnum >= sys_nerr) 4831 return ("Unknown error"); 4832 return (sys_errlist[errnum]); 4833 } 4834