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 #include <sys/resident.h> 50 #include <sys/tls.h> 51 52 #include <machine/tls.h> 53 54 #include <dlfcn.h> 55 #include <err.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <stdarg.h> 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 #include <unistd.h> 63 64 #include "debug.h" 65 #include "rtld.h" 66 #include "libmap.h" 67 #include "rtld_printf.h" 68 #include "notes.h" 69 70 #define PATH_RTLD "/usr/libexec/ld-elf.so.2" 71 #define LD_ARY_CACHE 16 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 *_getenv_ld(const char *id); 81 static void die(void) __dead2; 82 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 83 const Elf_Dyn **, const Elf_Dyn **); 84 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 85 const Elf_Dyn *); 86 static void digest_dynamic(Obj_Entry *, int); 87 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 88 static Obj_Entry *dlcheck(void *); 89 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 90 int lo_flags, int mode, RtldLockState *lockstate); 91 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 92 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 93 static bool donelist_check(DoneList *, const Obj_Entry *); 94 static void errmsg_restore(char *); 95 static char *errmsg_save(void); 96 static void *fill_search_info(const char *, size_t, void *); 97 static char *find_library(const char *, const Obj_Entry *); 98 static const char *gethints(bool); 99 static void init_dag(Obj_Entry *); 100 static void init_rtld(caddr_t, Elf_Auxinfo **); 101 static void initlist_add_neededs(Needed_Entry *, Objlist *); 102 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 103 static void linkmap_add(Obj_Entry *); 104 static void linkmap_delete(Obj_Entry *); 105 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 106 static void unload_filtees(Obj_Entry *); 107 static int load_needed_objects(Obj_Entry *, int); 108 static int load_preload_objects(void); 109 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 110 static void map_stacks_exec(RtldLockState *); 111 static Obj_Entry *obj_from_addr(const void *); 112 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 113 static void objlist_call_init(Objlist *, RtldLockState *); 114 static void objlist_clear(Objlist *); 115 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 116 static void objlist_init(Objlist *); 117 static void objlist_push_head(Objlist *, Obj_Entry *); 118 static void objlist_push_tail(Objlist *, Obj_Entry *); 119 static void objlist_remove(Objlist *, Obj_Entry *); 120 static void *path_enumerate(const char *, path_enum_proc, void *); 121 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 122 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 123 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 124 int flags, RtldLockState *lockstate); 125 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 126 RtldLockState *); 127 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 128 int flags, RtldLockState *lockstate); 129 static int rtld_dirname(const char *, char *); 130 static int rtld_dirname_abs(const char *, char *); 131 static void *rtld_dlopen(const char *name, int fd, int mode); 132 static void rtld_exit(void); 133 static char *search_library_path(const char *, const char *); 134 static const void **get_program_var_addr(const char *, RtldLockState *); 135 static void set_program_var(const char *, const void *); 136 static int symlook_default(SymLook *, const Obj_Entry *refobj); 137 static int symlook_global(SymLook *, DoneList *); 138 static void symlook_init_from_req(SymLook *, const SymLook *); 139 static int symlook_list(SymLook *, const Objlist *, DoneList *); 140 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 141 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 142 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 143 static void trace_loaded_objects(Obj_Entry *); 144 static void unlink_object(Obj_Entry *); 145 static void unload_object(Obj_Entry *); 146 static void unref_dag(Obj_Entry *); 147 static void ref_dag(Obj_Entry *); 148 static char *origin_subst_one(char *, const char *, const char *, bool); 149 static char *origin_subst(char *, const char *); 150 static void preinit_main(void); 151 static int rtld_verify_versions(const Objlist *); 152 static int rtld_verify_object_versions(Obj_Entry *); 153 static void object_add_name(Obj_Entry *, const char *); 154 static int object_match_name(const Obj_Entry *, const char *); 155 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 156 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 157 struct dl_phdr_info *phdr_info); 158 static uint_fast32_t gnu_hash (const char *); 159 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 160 const unsigned long); 161 162 void r_debug_state(struct r_debug *, struct link_map *) __noinline; 163 164 /* 165 * Data declarations. 166 */ 167 static char *error_message; /* Message for dlerror(), or NULL */ 168 struct r_debug r_debug; /* for GDB; */ 169 static bool libmap_disable; /* Disable libmap */ 170 static bool ld_loadfltr; /* Immediate filters processing */ 171 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 172 static bool trust; /* False for setuid and setgid programs */ 173 static bool dangerous_ld_env; /* True if environment variables have been 174 used to affect the libraries loaded */ 175 static const char *ld_bind_now; /* Environment variable for immediate binding */ 176 static const char *ld_debug; /* Environment variable for debugging */ 177 static const char *ld_library_path; /* Environment variable for search path */ 178 static char *ld_preload; /* Environment variable for libraries to 179 load first */ 180 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 181 static const char *ld_tracing; /* Called from ldd to print libs */ 182 static const char *ld_utrace; /* Use utrace() to log events. */ 183 static int (*rtld_functrace)( /* Optional function call tracing hook */ 184 const char *caller_obj, 185 const char *callee_obj, 186 const char *callee_func, 187 void *stack); 188 static const Obj_Entry *rtld_functrace_obj; /* Object thereof */ 189 static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 190 static Obj_Entry **obj_tail; /* Link field of last object in list */ 191 static Obj_Entry **preload_tail; 192 static Obj_Entry *obj_main; /* The main program shared object */ 193 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 194 static unsigned int obj_count; /* Number of objects in obj_list */ 195 static unsigned int obj_loads; /* Number of objects in obj_list */ 196 197 static int ld_resident; /* Non-zero if resident */ 198 static const char *ld_ary[LD_ARY_CACHE]; 199 static int ld_index; 200 static Objlist initlist; 201 202 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 203 STAILQ_HEAD_INITIALIZER(list_global); 204 static Objlist list_main = /* Objects loaded at program startup */ 205 STAILQ_HEAD_INITIALIZER(list_main); 206 static Objlist list_fini = /* Objects needing fini() calls */ 207 STAILQ_HEAD_INITIALIZER(list_fini); 208 209 static Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 210 const char *__ld_sharedlib_base; 211 212 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 213 214 extern Elf_Dyn _DYNAMIC; 215 #pragma weak _DYNAMIC 216 #ifndef RTLD_IS_DYNAMIC 217 #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 218 #endif 219 220 #ifdef ENABLE_OSRELDATE 221 int osreldate; 222 #endif 223 224 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 225 static int max_stack_flags; 226 227 /* 228 * Global declarations normally provided by crt1. The dynamic linker is 229 * not built with crt1, so we have to provide them ourselves. 230 */ 231 char *__progname; 232 char **environ; 233 234 /* 235 * Used to pass argc, argv to init functions. 236 */ 237 int main_argc; 238 char **main_argv; 239 240 /* 241 * Globals to control TLS allocation. 242 */ 243 size_t tls_last_offset; /* Static TLS offset of last module */ 244 size_t tls_last_size; /* Static TLS size of last module */ 245 size_t tls_static_space; /* Static TLS space allocated */ 246 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 247 int tls_max_index = 1; /* Largest module index allocated */ 248 249 /* 250 * Fill in a DoneList with an allocation large enough to hold all of 251 * the currently-loaded objects. Keep this as a macro since it calls 252 * alloca and we want that to occur within the scope of the caller. 253 */ 254 #define donelist_init(dlp) \ 255 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 256 assert((dlp)->objs != NULL), \ 257 (dlp)->num_alloc = obj_count, \ 258 (dlp)->num_used = 0) 259 260 #define UTRACE_DLOPEN_START 1 261 #define UTRACE_DLOPEN_STOP 2 262 #define UTRACE_DLCLOSE_START 3 263 #define UTRACE_DLCLOSE_STOP 4 264 #define UTRACE_LOAD_OBJECT 5 265 #define UTRACE_UNLOAD_OBJECT 6 266 #define UTRACE_ADD_RUNDEP 7 267 #define UTRACE_PRELOAD_FINISHED 8 268 #define UTRACE_INIT_CALL 9 269 #define UTRACE_FINI_CALL 10 270 271 struct utrace_rtld { 272 char sig[4]; /* 'RTLD' */ 273 int event; 274 void *handle; 275 void *mapbase; /* Used for 'parent' and 'init/fini' */ 276 size_t mapsize; 277 int refcnt; /* Used for 'mode' */ 278 char name[MAXPATHLEN]; 279 }; 280 281 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 282 if (ld_utrace != NULL) \ 283 ld_utrace_log(e, h, mb, ms, r, n); \ 284 } while (0) 285 286 static void 287 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 288 int refcnt, const char *name) 289 { 290 struct utrace_rtld ut; 291 292 ut.sig[0] = 'R'; 293 ut.sig[1] = 'T'; 294 ut.sig[2] = 'L'; 295 ut.sig[3] = 'D'; 296 ut.event = event; 297 ut.handle = handle; 298 ut.mapbase = mapbase; 299 ut.mapsize = mapsize; 300 ut.refcnt = refcnt; 301 bzero(ut.name, sizeof(ut.name)); 302 if (name) 303 strlcpy(ut.name, name, sizeof(ut.name)); 304 utrace(&ut, sizeof(ut)); 305 } 306 307 /* 308 * Main entry point for dynamic linking. The first argument is the 309 * stack pointer. The stack is expected to be laid out as described 310 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 311 * Specifically, the stack pointer points to a word containing 312 * ARGC. Following that in the stack is a null-terminated sequence 313 * of pointers to argument strings. Then comes a null-terminated 314 * sequence of pointers to environment strings. Finally, there is a 315 * sequence of "auxiliary vector" entries. 316 * 317 * The second argument points to a place to store the dynamic linker's 318 * exit procedure pointer and the third to a place to store the main 319 * program's object. 320 * 321 * The return value is the main program's entry point. 322 */ 323 func_ptr_type 324 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 325 { 326 Elf_Auxinfo *aux_info[AT_COUNT]; 327 int i; 328 int argc; 329 char **argv; 330 char **env; 331 Elf_Auxinfo *aux; 332 Elf_Auxinfo *auxp; 333 const char *argv0; 334 Objlist_Entry *entry; 335 Obj_Entry *obj; 336 337 /* marino: DO NOT MOVE THESE VARIABLES TO _rtld 338 Obj_Entry **preload_tail; 339 Objlist initlist; 340 from global to here. It will break the DWARF2 unwind scheme. 341 The system compilers were unaffected, but not gcc 4.6 342 */ 343 344 /* 345 * On entry, the dynamic linker itself has not been relocated yet. 346 * Be very careful not to reference any global data until after 347 * init_rtld has returned. It is OK to reference file-scope statics 348 * and string constants, and to call static and global functions. 349 */ 350 351 /* Find the auxiliary vector on the stack. */ 352 argc = *sp++; 353 argv = (char **) sp; 354 sp += argc + 1; /* Skip over arguments and NULL terminator */ 355 env = (char **) sp; 356 357 /* 358 * If we aren't already resident we have to dig out some more info. 359 * Note that auxinfo does not exist when we are resident. 360 * 361 * I'm not sure about the ld_resident check. It seems to read zero 362 * prior to relocation, which is what we want. When running from a 363 * resident copy everything will be relocated so we are definitely 364 * good there. 365 */ 366 if (ld_resident == 0) { 367 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 368 ; 369 aux = (Elf_Auxinfo *) sp; 370 371 /* Digest the auxiliary vector. */ 372 for (i = 0; i < AT_COUNT; i++) 373 aux_info[i] = NULL; 374 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 375 if (auxp->a_type < AT_COUNT) 376 aux_info[auxp->a_type] = auxp; 377 } 378 379 /* Initialize and relocate ourselves. */ 380 assert(aux_info[AT_BASE] != NULL); 381 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 382 } 383 384 ld_index = 0; /* don't use old env cache in case we are resident */ 385 __progname = obj_rtld.path; 386 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 387 environ = env; 388 main_argc = argc; 389 main_argv = argv; 390 391 trust = !issetugid(); 392 393 ld_bind_now = _getenv_ld("LD_BIND_NOW"); 394 /* 395 * If the process is tainted, then we un-set the dangerous environment 396 * variables. The process will be marked as tainted until setuid(2) 397 * is called. If any child process calls setuid(2) we do not want any 398 * future processes to honor the potentially un-safe variables. 399 */ 400 if (!trust) { 401 if ( unsetenv("LD_DEBUG") 402 || unsetenv("LD_PRELOAD") 403 || unsetenv("LD_LIBRARY_PATH") 404 || unsetenv("LD_ELF_HINTS_PATH") 405 || unsetenv("LD_LIBMAP") 406 || unsetenv("LD_LIBMAP_DISABLE") 407 || unsetenv("LD_LOADFLTR") 408 || unsetenv("LD_SHAREDLIB_BASE") 409 ) { 410 _rtld_error("environment corrupt; aborting"); 411 die(); 412 } 413 } 414 __ld_sharedlib_base = _getenv_ld("LD_SHAREDLIB_BASE"); 415 ld_debug = _getenv_ld("LD_DEBUG"); 416 libmap_disable = _getenv_ld("LD_LIBMAP_DISABLE") != NULL; 417 libmap_override = (char *)_getenv_ld("LD_LIBMAP"); 418 ld_library_path = _getenv_ld("LD_LIBRARY_PATH"); 419 ld_preload = (char *)_getenv_ld("LD_PRELOAD"); 420 ld_elf_hints_path = _getenv_ld("LD_ELF_HINTS_PATH"); 421 ld_loadfltr = _getenv_ld("LD_LOADFLTR") != NULL; 422 dangerous_ld_env = (ld_library_path != NULL) 423 || (ld_preload != NULL) 424 || (ld_elf_hints_path != NULL) 425 || ld_loadfltr 426 || (libmap_override != NULL) 427 || libmap_disable 428 ; 429 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS"); 430 ld_utrace = _getenv_ld("LD_UTRACE"); 431 432 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 433 ld_elf_hints_path = _PATH_ELF_HINTS; 434 435 if (ld_debug != NULL && *ld_debug != '\0') 436 debug = 1; 437 dbg("%s is initialized, base address = %p", __progname, 438 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 439 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 440 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 441 442 dbg("initializing thread locks"); 443 lockdflt_init(); 444 445 /* 446 * If we are resident we can skip work that we have already done. 447 * Note that the stack is reset and there is no Elf_Auxinfo 448 * when running from a resident image, and the static globals setup 449 * between here and resident_skip will have already been setup. 450 */ 451 if (ld_resident) 452 goto resident_skip1; 453 454 /* 455 * Load the main program, or process its program header if it is 456 * already loaded. 457 */ 458 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 459 int fd = aux_info[AT_EXECFD]->a_un.a_val; 460 dbg("loading main program"); 461 obj_main = map_object(fd, argv0, NULL); 462 close(fd); 463 if (obj_main == NULL) 464 die(); 465 max_stack_flags = obj->stack_flags; 466 } else { /* Main program already loaded. */ 467 const Elf_Phdr *phdr; 468 int phnum; 469 caddr_t entry; 470 471 dbg("processing main program's program header"); 472 assert(aux_info[AT_PHDR] != NULL); 473 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 474 assert(aux_info[AT_PHNUM] != NULL); 475 phnum = aux_info[AT_PHNUM]->a_un.a_val; 476 assert(aux_info[AT_PHENT] != NULL); 477 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 478 assert(aux_info[AT_ENTRY] != NULL); 479 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 480 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 481 die(); 482 } 483 484 char buf[MAXPATHLEN]; 485 if (aux_info[AT_EXECPATH] != NULL) { 486 char *kexecpath; 487 488 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 489 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 490 if (kexecpath[0] == '/') 491 obj_main->path = kexecpath; 492 else if (getcwd(buf, sizeof(buf)) == NULL || 493 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 494 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 495 obj_main->path = xstrdup(argv0); 496 else 497 obj_main->path = xstrdup(buf); 498 } else { 499 char resolved[MAXPATHLEN]; 500 dbg("No AT_EXECPATH"); 501 if (argv0[0] == '/') { 502 if (realpath(argv0, resolved) != NULL) 503 obj_main->path = xstrdup(resolved); 504 else 505 obj_main->path = xstrdup(argv0); 506 } else { 507 if (getcwd(buf, sizeof(buf)) != NULL 508 && strlcat(buf, "/", sizeof(buf)) < sizeof(buf) 509 && strlcat(buf, argv0, sizeof (buf)) < sizeof(buf) 510 && access(buf, R_OK) == 0 511 && realpath(buf, resolved) != NULL) 512 obj_main->path = xstrdup(resolved); 513 else 514 obj_main->path = xstrdup(argv0); 515 } 516 } 517 dbg("obj_main path %s", obj_main->path); 518 obj_main->mainprog = true; 519 520 if (aux_info[AT_STACKPROT] != NULL && 521 aux_info[AT_STACKPROT]->a_un.a_val != 0) 522 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 523 524 /* 525 * Get the actual dynamic linker pathname from the executable if 526 * possible. (It should always be possible.) That ensures that 527 * gdb will find the right dynamic linker even if a non-standard 528 * one is being used. 529 */ 530 if (obj_main->interp != NULL && 531 strcmp(obj_main->interp, obj_rtld.path) != 0) { 532 free(obj_rtld.path); 533 obj_rtld.path = xstrdup(obj_main->interp); 534 __progname = obj_rtld.path; 535 } 536 537 digest_dynamic(obj_main, 0); 538 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 539 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 540 obj_main->dynsymcount); 541 542 linkmap_add(obj_main); 543 linkmap_add(&obj_rtld); 544 545 /* Link the main program into the list of objects. */ 546 *obj_tail = obj_main; 547 obj_tail = &obj_main->next; 548 obj_count++; 549 obj_loads++; 550 551 /* Initialize a fake symbol for resolving undefined weak references. */ 552 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 553 sym_zero.st_shndx = SHN_UNDEF; 554 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 555 556 if (!libmap_disable) 557 libmap_disable = (bool)lm_init(libmap_override); 558 559 dbg("loading LD_PRELOAD libraries"); 560 if (load_preload_objects() == -1) 561 die(); 562 preload_tail = obj_tail; 563 564 dbg("loading needed objects"); 565 if (load_needed_objects(obj_main, 0) == -1) 566 die(); 567 568 /* Make a list of all objects loaded at startup. */ 569 for (obj = obj_list; obj != NULL; obj = obj->next) { 570 objlist_push_tail(&list_main, obj); 571 obj->refcount++; 572 } 573 574 dbg("checking for required versions"); 575 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 576 die(); 577 578 resident_skip1: 579 580 if (ld_tracing) { /* We're done */ 581 trace_loaded_objects(obj_main); 582 exit(0); 583 } 584 585 if (ld_resident) /* XXX clean this up! */ 586 goto resident_skip2; 587 588 if (_getenv_ld("LD_DUMP_REL_PRE") != NULL) { 589 dump_relocations(obj_main); 590 exit (0); 591 } 592 593 /* setup TLS for main thread */ 594 dbg("initializing initial thread local storage"); 595 STAILQ_FOREACH(entry, &list_main, link) { 596 /* 597 * Allocate all the initial objects out of the static TLS 598 * block even if they didn't ask for it. 599 */ 600 allocate_tls_offset(entry->obj); 601 } 602 603 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA; 604 605 /* 606 * Do not try to allocate the TLS here, let libc do it itself. 607 * (crt1 for the program will call _init_tls()) 608 */ 609 610 if (relocate_objects(obj_main, 611 ld_bind_now != NULL && *ld_bind_now != '\0', 612 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 613 die(); 614 615 dbg("doing copy relocations"); 616 if (do_copy_relocations(obj_main) == -1) 617 die(); 618 619 resident_skip2: 620 621 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) { 622 if (exec_sys_unregister(-1) < 0) { 623 dbg("exec_sys_unregister failed %d\n", errno); 624 exit(errno); 625 } 626 dbg("exec_sys_unregister success\n"); 627 exit(0); 628 } 629 630 if (_getenv_ld("LD_DUMP_REL_POST") != NULL) { 631 dump_relocations(obj_main); 632 exit (0); 633 } 634 635 dbg("initializing key program variables"); 636 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 637 set_program_var("environ", env); 638 set_program_var("__elf_aux_vector", aux); 639 640 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) { 641 extern void resident_start(void); 642 ld_resident = 1; 643 if (exec_sys_register(resident_start) < 0) { 644 dbg("exec_sys_register failed %d\n", errno); 645 exit(errno); 646 } 647 dbg("exec_sys_register success\n"); 648 exit(0); 649 } 650 651 /* Make a list of init functions to call. */ 652 objlist_init(&initlist); 653 initlist_add_objects(obj_list, preload_tail, &initlist); 654 655 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 656 657 map_stacks_exec(NULL); 658 659 dbg("resolving ifuncs"); 660 if (resolve_objects_ifunc(obj_main, 661 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 662 NULL) == -1) 663 die(); 664 665 /* 666 * Do NOT call the initlist here, give libc a chance to set up 667 * the initial TLS segment. crt1 will then call _rtld_call_init(). 668 */ 669 670 dbg("transferring control to program entry point = %p", obj_main->entry); 671 672 /* Return the exit procedure and the program entry point. */ 673 *exit_proc = rtld_exit; 674 *objp = obj_main; 675 return (func_ptr_type) obj_main->entry; 676 } 677 678 /* 679 * Call the initialization list for dynamically loaded libraries. 680 * (called from crt1.c). 681 */ 682 void 683 _rtld_call_init(void) 684 { 685 RtldLockState lockstate; 686 Obj_Entry *obj; 687 688 if (!obj_main->note_present && obj_main->valid_hash_gnu) { 689 /* 690 * The use of a linker script with a PHDRS directive that does not include 691 * PT_NOTE will block the crt_no_init note. In this case we'll look for the 692 * recently added GNU hash dynamic tag which gets built by default. It is 693 * extremely unlikely to find a pre-3.1 binary without a PT_NOTE header and 694 * a gnu hash tag. If gnu hash found, consider binary to use new crt code. 695 */ 696 obj_main->crt_no_init = true; 697 dbg("Setting crt_no_init without presence of PT_NOTE header"); 698 } 699 700 wlock_acquire(rtld_bind_lock, &lockstate); 701 if (obj_main->crt_no_init) 702 preinit_main(); 703 else { 704 /* 705 * Make sure we don't call the main program's init and fini functions 706 * for binaries linked with old crt1 which calls _init itself. 707 */ 708 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 709 obj_main->init_array = obj_main->fini_array = (Elf_Addr)NULL; 710 } 711 objlist_call_init(&initlist, &lockstate); 712 objlist_clear(&initlist); 713 dbg("loading filtees"); 714 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 715 if (ld_loadfltr || obj->z_loadfltr) 716 load_filtees(obj, 0, &lockstate); 717 } 718 lock_release(rtld_bind_lock, &lockstate); 719 } 720 721 void * 722 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 723 { 724 void *ptr; 725 Elf_Addr target; 726 727 ptr = (void *)make_function_pointer(def, obj); 728 target = ((Elf_Addr (*)(void))ptr)(); 729 return ((void *)target); 730 } 731 732 Elf_Addr 733 _rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack) 734 { 735 const Elf_Rel *rel; 736 const Elf_Sym *def; 737 const Obj_Entry *defobj; 738 Elf_Addr *where; 739 Elf_Addr target; 740 RtldLockState lockstate; 741 742 rlock_acquire(rtld_bind_lock, &lockstate); 743 if (sigsetjmp(lockstate.env, 0) != 0) 744 lock_upgrade(rtld_bind_lock, &lockstate); 745 if (obj->pltrel) 746 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 747 else 748 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 749 750 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 751 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 752 &lockstate); 753 if (def == NULL) 754 die(); 755 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 756 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 757 else 758 target = (Elf_Addr)(defobj->relocbase + def->st_value); 759 760 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 761 defobj->strtab + def->st_name, basename(obj->path), 762 (void *)target, basename(defobj->path)); 763 764 /* 765 * If we have a function call tracing hook, and the 766 * hook would like to keep tracing this one function, 767 * prevent the relocation so we will wind up here 768 * the next time again. 769 * 770 * We don't want to functrace calls from the functracer 771 * to avoid recursive loops. 772 */ 773 if (rtld_functrace != NULL && obj != rtld_functrace_obj) { 774 if (rtld_functrace(obj->path, 775 defobj->path, 776 defobj->strtab + def->st_name, 777 stack)) { 778 lock_release(rtld_bind_lock, &lockstate); 779 return target; 780 } 781 } 782 783 /* 784 * Write the new contents for the jmpslot. Note that depending on 785 * architecture, the value which we need to return back to the 786 * lazy binding trampoline may or may not be the target 787 * address. The value returned from reloc_jmpslot() is the value 788 * that the trampoline needs. 789 */ 790 target = reloc_jmpslot(where, target, defobj, obj, rel); 791 lock_release(rtld_bind_lock, &lockstate); 792 return target; 793 } 794 795 /* 796 * Error reporting function. Use it like printf. If formats the message 797 * into a buffer, and sets things up so that the next call to dlerror() 798 * will return the message. 799 */ 800 void 801 _rtld_error(const char *fmt, ...) 802 { 803 static char buf[512]; 804 va_list ap; 805 806 va_start(ap, fmt); 807 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 808 error_message = buf; 809 va_end(ap); 810 } 811 812 /* 813 * Return a dynamically-allocated copy of the current error message, if any. 814 */ 815 static char * 816 errmsg_save(void) 817 { 818 return error_message == NULL ? NULL : xstrdup(error_message); 819 } 820 821 /* 822 * Restore the current error message from a copy which was previously saved 823 * by errmsg_save(). The copy is freed. 824 */ 825 static void 826 errmsg_restore(char *saved_msg) 827 { 828 if (saved_msg == NULL) 829 error_message = NULL; 830 else { 831 _rtld_error("%s", saved_msg); 832 free(saved_msg); 833 } 834 } 835 836 const char * 837 basename(const char *name) 838 { 839 const char *p = strrchr(name, '/'); 840 return p != NULL ? p + 1 : name; 841 } 842 843 static struct utsname uts; 844 845 static char * 846 origin_subst_one(char *real, const char *kw, const char *subst, 847 bool may_free) 848 { 849 char *p, *p1, *res, *resp; 850 int subst_len, kw_len, subst_count, old_len, new_len; 851 852 kw_len = strlen(kw); 853 854 /* 855 * First, count the number of the keyword occurences, to 856 * preallocate the final string. 857 */ 858 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 859 p1 = strstr(p, kw); 860 if (p1 == NULL) 861 break; 862 } 863 864 /* 865 * If the keyword is not found, just return. 866 */ 867 if (subst_count == 0) 868 return (may_free ? real : xstrdup(real)); 869 870 /* 871 * There is indeed something to substitute. Calculate the 872 * length of the resulting string, and allocate it. 873 */ 874 subst_len = strlen(subst); 875 old_len = strlen(real); 876 new_len = old_len + (subst_len - kw_len) * subst_count; 877 res = xmalloc(new_len + 1); 878 879 /* 880 * Now, execute the substitution loop. 881 */ 882 for (p = real, resp = res, *resp = '\0';;) { 883 p1 = strstr(p, kw); 884 if (p1 != NULL) { 885 /* Copy the prefix before keyword. */ 886 memcpy(resp, p, p1 - p); 887 resp += p1 - p; 888 /* Keyword replacement. */ 889 memcpy(resp, subst, subst_len); 890 resp += subst_len; 891 *resp = '\0'; 892 p = p1 + kw_len; 893 } else 894 break; 895 } 896 897 /* Copy to the end of string and finish. */ 898 strcat(resp, p); 899 if (may_free) 900 free(real); 901 return (res); 902 } 903 904 static char * 905 origin_subst(char *real, const char *origin_path) 906 { 907 char *res1, *res2, *res3, *res4; 908 909 if (uts.sysname[0] == '\0') { 910 if (uname(&uts) != 0) { 911 _rtld_error("utsname failed: %d", errno); 912 return (NULL); 913 } 914 } 915 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 916 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 917 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 918 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 919 return (res4); 920 } 921 922 static void 923 die(void) 924 { 925 const char *msg = dlerror(); 926 927 if (msg == NULL) 928 msg = "Fatal error"; 929 rtld_fdputstr(STDERR_FILENO, msg); 930 rtld_fdputchar(STDERR_FILENO, '\n'); 931 _exit(1); 932 } 933 934 /* 935 * Process a shared object's DYNAMIC section, and save the important 936 * information in its Obj_Entry structure. 937 */ 938 static void 939 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 940 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 941 { 942 const Elf_Dyn *dynp; 943 Needed_Entry **needed_tail = &obj->needed; 944 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 945 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 946 const Elf_Hashelt *hashtab; 947 const Elf32_Word *hashval; 948 Elf32_Word bkt, nmaskwords; 949 int bloom_size32; 950 bool nmw_power2; 951 int plttype = DT_REL; 952 953 *dyn_rpath = NULL; 954 *dyn_soname = NULL; 955 *dyn_runpath = NULL; 956 957 obj->bind_now = false; 958 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 959 switch (dynp->d_tag) { 960 961 case DT_REL: 962 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 963 break; 964 965 case DT_RELSZ: 966 obj->relsize = dynp->d_un.d_val; 967 break; 968 969 case DT_RELENT: 970 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 971 break; 972 973 case DT_JMPREL: 974 obj->pltrel = (const Elf_Rel *) 975 (obj->relocbase + dynp->d_un.d_ptr); 976 break; 977 978 case DT_PLTRELSZ: 979 obj->pltrelsize = dynp->d_un.d_val; 980 break; 981 982 case DT_RELA: 983 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 984 break; 985 986 case DT_RELASZ: 987 obj->relasize = dynp->d_un.d_val; 988 break; 989 990 case DT_RELAENT: 991 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 992 break; 993 994 case DT_PLTREL: 995 plttype = dynp->d_un.d_val; 996 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 997 break; 998 999 case DT_SYMTAB: 1000 obj->symtab = (const Elf_Sym *) 1001 (obj->relocbase + dynp->d_un.d_ptr); 1002 break; 1003 1004 case DT_SYMENT: 1005 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1006 break; 1007 1008 case DT_STRTAB: 1009 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 1010 break; 1011 1012 case DT_STRSZ: 1013 obj->strsize = dynp->d_un.d_val; 1014 break; 1015 1016 case DT_VERNEED: 1017 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 1018 dynp->d_un.d_val); 1019 break; 1020 1021 case DT_VERNEEDNUM: 1022 obj->verneednum = dynp->d_un.d_val; 1023 break; 1024 1025 case DT_VERDEF: 1026 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 1027 dynp->d_un.d_val); 1028 break; 1029 1030 case DT_VERDEFNUM: 1031 obj->verdefnum = dynp->d_un.d_val; 1032 break; 1033 1034 case DT_VERSYM: 1035 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1036 dynp->d_un.d_val); 1037 break; 1038 1039 case DT_HASH: 1040 { 1041 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1042 dynp->d_un.d_ptr); 1043 obj->nbuckets = hashtab[0]; 1044 obj->nchains = hashtab[1]; 1045 obj->buckets = hashtab + 2; 1046 obj->chains = obj->buckets + obj->nbuckets; 1047 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1048 obj->buckets != NULL; 1049 } 1050 break; 1051 1052 case DT_GNU_HASH: 1053 { 1054 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1055 dynp->d_un.d_ptr); 1056 obj->nbuckets_gnu = hashtab[0]; 1057 obj->symndx_gnu = hashtab[1]; 1058 nmaskwords = hashtab[2]; 1059 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1060 /* Number of bitmask words is required to be power of 2 */ 1061 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 1062 obj->maskwords_bm_gnu = nmaskwords - 1; 1063 obj->shift2_gnu = hashtab[3]; 1064 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 1065 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1066 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1067 obj->symndx_gnu; 1068 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 1069 obj->buckets_gnu != NULL; 1070 } 1071 break; 1072 1073 case DT_NEEDED: 1074 if (!obj->rtld) { 1075 Needed_Entry *nep = NEW(Needed_Entry); 1076 nep->name = dynp->d_un.d_val; 1077 nep->obj = NULL; 1078 nep->next = NULL; 1079 1080 *needed_tail = nep; 1081 needed_tail = &nep->next; 1082 } 1083 break; 1084 1085 case DT_FILTER: 1086 if (!obj->rtld) { 1087 Needed_Entry *nep = NEW(Needed_Entry); 1088 nep->name = dynp->d_un.d_val; 1089 nep->obj = NULL; 1090 nep->next = NULL; 1091 1092 *needed_filtees_tail = nep; 1093 needed_filtees_tail = &nep->next; 1094 } 1095 break; 1096 1097 case DT_AUXILIARY: 1098 if (!obj->rtld) { 1099 Needed_Entry *nep = NEW(Needed_Entry); 1100 nep->name = dynp->d_un.d_val; 1101 nep->obj = NULL; 1102 nep->next = NULL; 1103 1104 *needed_aux_filtees_tail = nep; 1105 needed_aux_filtees_tail = &nep->next; 1106 } 1107 break; 1108 1109 case DT_PLTGOT: 1110 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1111 break; 1112 1113 case DT_TEXTREL: 1114 obj->textrel = true; 1115 break; 1116 1117 case DT_SYMBOLIC: 1118 obj->symbolic = true; 1119 break; 1120 1121 case DT_RPATH: 1122 /* 1123 * We have to wait until later to process this, because we 1124 * might not have gotten the address of the string table yet. 1125 */ 1126 *dyn_rpath = dynp; 1127 break; 1128 1129 case DT_SONAME: 1130 *dyn_soname = dynp; 1131 break; 1132 1133 case DT_RUNPATH: 1134 *dyn_runpath = dynp; 1135 break; 1136 1137 case DT_INIT: 1138 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1139 break; 1140 1141 case DT_FINI: 1142 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1143 break; 1144 1145 case DT_PREINIT_ARRAY: 1146 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1147 break; 1148 1149 case DT_INIT_ARRAY: 1150 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1151 break; 1152 1153 case DT_FINI_ARRAY: 1154 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1155 break; 1156 1157 case DT_PREINIT_ARRAYSZ: 1158 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1159 break; 1160 1161 case DT_INIT_ARRAYSZ: 1162 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1163 break; 1164 1165 case DT_FINI_ARRAYSZ: 1166 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1167 break; 1168 1169 case DT_DEBUG: 1170 /* XXX - not implemented yet */ 1171 if (!early) 1172 dbg("Filling in DT_DEBUG entry"); 1173 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1174 break; 1175 1176 case DT_FLAGS: 1177 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1178 obj->z_origin = true; 1179 if (dynp->d_un.d_val & DF_SYMBOLIC) 1180 obj->symbolic = true; 1181 if (dynp->d_un.d_val & DF_TEXTREL) 1182 obj->textrel = true; 1183 if (dynp->d_un.d_val & DF_BIND_NOW) 1184 obj->bind_now = true; 1185 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1186 ;*/ 1187 break; 1188 1189 case DT_FLAGS_1: 1190 if (dynp->d_un.d_val & DF_1_NOOPEN) 1191 obj->z_noopen = true; 1192 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1193 obj->z_origin = true; 1194 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1195 XXX ;*/ 1196 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1197 obj->bind_now = true; 1198 if (dynp->d_un.d_val & DF_1_NODELETE) 1199 obj->z_nodelete = true; 1200 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1201 obj->z_loadfltr = true; 1202 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1203 obj->z_nodeflib = true; 1204 break; 1205 1206 default: 1207 if (!early) { 1208 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1209 (long)dynp->d_tag); 1210 } 1211 break; 1212 } 1213 } 1214 1215 obj->traced = false; 1216 1217 if (plttype == DT_RELA) { 1218 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1219 obj->pltrel = NULL; 1220 obj->pltrelasize = obj->pltrelsize; 1221 obj->pltrelsize = 0; 1222 } 1223 1224 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1225 if (obj->valid_hash_sysv) 1226 obj->dynsymcount = obj->nchains; 1227 else if (obj->valid_hash_gnu) { 1228 obj->dynsymcount = 0; 1229 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1230 if (obj->buckets_gnu[bkt] == 0) 1231 continue; 1232 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1233 do 1234 obj->dynsymcount++; 1235 while ((*hashval++ & 1u) == 0); 1236 } 1237 obj->dynsymcount += obj->symndx_gnu; 1238 } 1239 } 1240 1241 static void 1242 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1243 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1244 { 1245 1246 if (obj->z_origin && obj->origin_path == NULL) { 1247 obj->origin_path = xmalloc(PATH_MAX); 1248 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1249 die(); 1250 } 1251 1252 if (dyn_runpath != NULL) { 1253 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1254 if (obj->z_origin) 1255 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1256 } 1257 else if (dyn_rpath != NULL) { 1258 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1259 if (obj->z_origin) 1260 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1261 } 1262 1263 if (dyn_soname != NULL) 1264 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1265 } 1266 1267 static void 1268 digest_dynamic(Obj_Entry *obj, int early) 1269 { 1270 const Elf_Dyn *dyn_rpath; 1271 const Elf_Dyn *dyn_soname; 1272 const Elf_Dyn *dyn_runpath; 1273 1274 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1275 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1276 } 1277 1278 /* 1279 * Process a shared object's program header. This is used only for the 1280 * main program, when the kernel has already loaded the main program 1281 * into memory before calling the dynamic linker. It creates and 1282 * returns an Obj_Entry structure. 1283 */ 1284 static Obj_Entry * 1285 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1286 { 1287 Obj_Entry *obj; 1288 const Elf_Phdr *phlimit = phdr + phnum; 1289 const Elf_Phdr *ph; 1290 Elf_Addr note_start, note_end; 1291 int nsegs = 0; 1292 1293 obj = obj_new(); 1294 for (ph = phdr; ph < phlimit; ph++) { 1295 if (ph->p_type != PT_PHDR) 1296 continue; 1297 1298 obj->phdr = phdr; 1299 obj->phsize = ph->p_memsz; 1300 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1301 break; 1302 } 1303 1304 obj->stack_flags = PF_X | PF_R | PF_W; 1305 1306 for (ph = phdr; ph < phlimit; ph++) { 1307 switch (ph->p_type) { 1308 1309 case PT_INTERP: 1310 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1311 break; 1312 1313 case PT_LOAD: 1314 if (nsegs == 0) { /* First load segment */ 1315 obj->vaddrbase = trunc_page(ph->p_vaddr); 1316 obj->mapbase = obj->vaddrbase + obj->relocbase; 1317 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1318 obj->vaddrbase; 1319 } else { /* Last load segment */ 1320 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1321 obj->vaddrbase; 1322 } 1323 nsegs++; 1324 break; 1325 1326 case PT_DYNAMIC: 1327 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1328 break; 1329 1330 case PT_TLS: 1331 obj->tlsindex = 1; 1332 obj->tlssize = ph->p_memsz; 1333 obj->tlsalign = ph->p_align; 1334 obj->tlsinitsize = ph->p_filesz; 1335 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1336 break; 1337 1338 case PT_GNU_STACK: 1339 obj->stack_flags = ph->p_flags; 1340 break; 1341 1342 case PT_GNU_RELRO: 1343 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1344 obj->relro_size = round_page(ph->p_memsz); 1345 break; 1346 1347 case PT_NOTE: 1348 obj->note_present = true; 1349 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1350 note_end = note_start + ph->p_filesz; 1351 digest_notes(obj, note_start, note_end); 1352 break; 1353 } 1354 } 1355 if (nsegs < 1) { 1356 _rtld_error("%s: too few PT_LOAD segments", path); 1357 return NULL; 1358 } 1359 1360 obj->entry = entry; 1361 return obj; 1362 } 1363 1364 void 1365 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1366 { 1367 const Elf_Note *note; 1368 const char *note_name; 1369 uintptr_t p; 1370 1371 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1372 note = (const Elf_Note *)((const char *)(note + 1) + 1373 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1374 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1375 if (note->n_namesz != sizeof(NOTE_VENDOR) || 1376 note->n_descsz != sizeof(int32_t)) 1377 continue; 1378 if (note->n_type != ABI_NOTETYPE && 1379 note->n_type != CRT_NOINIT_NOTETYPE) 1380 continue; 1381 note_name = (const char *)(note + 1); 1382 if (strncmp(NOTE_VENDOR, note_name, sizeof(NOTE_VENDOR)) != 0) 1383 continue; 1384 switch (note->n_type) { 1385 case ABI_NOTETYPE: 1386 /* DragonFly osrel note */ 1387 p = (uintptr_t)(note + 1); 1388 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1389 obj->osrel = *(const int32_t *)(p); 1390 dbg("note osrel %d", obj->osrel); 1391 break; 1392 case CRT_NOINIT_NOTETYPE: 1393 /* DragonFly 'crt does not call init' note */ 1394 obj->crt_no_init = true; 1395 dbg("note crt_no_init"); 1396 break; 1397 } 1398 } 1399 } 1400 1401 static Obj_Entry * 1402 dlcheck(void *handle) 1403 { 1404 Obj_Entry *obj; 1405 1406 for (obj = obj_list; obj != NULL; obj = obj->next) 1407 if (obj == (Obj_Entry *) handle) 1408 break; 1409 1410 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1411 _rtld_error("Invalid shared object handle %p", handle); 1412 return NULL; 1413 } 1414 return obj; 1415 } 1416 1417 /* 1418 * If the given object is already in the donelist, return true. Otherwise 1419 * add the object to the list and return false. 1420 */ 1421 static bool 1422 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1423 { 1424 unsigned int i; 1425 1426 for (i = 0; i < dlp->num_used; i++) 1427 if (dlp->objs[i] == obj) 1428 return true; 1429 /* 1430 * Our donelist allocation should always be sufficient. But if 1431 * our threads locking isn't working properly, more shared objects 1432 * could have been loaded since we allocated the list. That should 1433 * never happen, but we'll handle it properly just in case it does. 1434 */ 1435 if (dlp->num_used < dlp->num_alloc) 1436 dlp->objs[dlp->num_used++] = obj; 1437 return false; 1438 } 1439 1440 /* 1441 * Hash function for symbol table lookup. Don't even think about changing 1442 * this. It is specified by the System V ABI. 1443 */ 1444 unsigned long 1445 elf_hash(const char *name) 1446 { 1447 const unsigned char *p = (const unsigned char *) name; 1448 unsigned long h = 0; 1449 unsigned long g; 1450 1451 while (*p != '\0') { 1452 h = (h << 4) + *p++; 1453 if ((g = h & 0xf0000000) != 0) 1454 h ^= g >> 24; 1455 h &= ~g; 1456 } 1457 return h; 1458 } 1459 1460 /* 1461 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1462 * unsigned in case it's implemented with a wider type. 1463 */ 1464 static uint_fast32_t 1465 gnu_hash(const char *s) 1466 { 1467 uint_fast32_t h; 1468 unsigned char c; 1469 1470 h = 5381; 1471 for (c = *s; c != '\0'; c = *++s) 1472 h = h * 33 + c; 1473 return (h & 0xffffffff); 1474 } 1475 1476 /* 1477 * Find the library with the given name, and return its full pathname. 1478 * The returned string is dynamically allocated. Generates an error 1479 * message and returns NULL if the library cannot be found. 1480 * 1481 * If the second argument is non-NULL, then it refers to an already- 1482 * loaded shared object, whose library search path will be searched. 1483 * 1484 * The search order is: 1485 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1486 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1487 * LD_LIBRARY_PATH 1488 * DT_RUNPATH in the referencing file 1489 * ldconfig hints (if -z nodefaultlib, filter out /usr/lib from list) 1490 * /usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1491 * 1492 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1493 */ 1494 static char * 1495 find_library(const char *xname, const Obj_Entry *refobj) 1496 { 1497 char *pathname; 1498 char *name; 1499 bool nodeflib, objgiven; 1500 1501 objgiven = refobj != NULL; 1502 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1503 if (xname[0] != '/' && !trust) { 1504 _rtld_error("Absolute pathname required for shared object \"%s\"", 1505 xname); 1506 return NULL; 1507 } 1508 if (objgiven && refobj->z_origin) { 1509 return (origin_subst(__DECONST(char *, xname), 1510 refobj->origin_path)); 1511 } else { 1512 return (xstrdup(xname)); 1513 } 1514 } 1515 1516 if (libmap_disable || !objgiven || 1517 (name = lm_find(refobj->path, xname)) == NULL) 1518 name = (char *)xname; 1519 1520 dbg(" Searching for \"%s\"", name); 1521 1522 nodeflib = objgiven ? refobj->z_nodeflib : false; 1523 if ((objgiven && 1524 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1525 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1526 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1527 (pathname = search_library_path(name, ld_library_path)) != NULL || 1528 (objgiven && 1529 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1530 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1531 (objgiven && !nodeflib && 1532 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1533 return (pathname); 1534 1535 if (objgiven && refobj->path != NULL) { 1536 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1537 name, basename(refobj->path)); 1538 } else { 1539 _rtld_error("Shared object \"%s\" not found", name); 1540 } 1541 return NULL; 1542 } 1543 1544 /* 1545 * Given a symbol number in a referencing object, find the corresponding 1546 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1547 * no definition was found. Returns a pointer to the Obj_Entry of the 1548 * defining object via the reference parameter DEFOBJ_OUT. 1549 */ 1550 const Elf_Sym * 1551 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1552 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1553 RtldLockState *lockstate) 1554 { 1555 const Elf_Sym *ref; 1556 const Elf_Sym *def; 1557 const Obj_Entry *defobj; 1558 SymLook req; 1559 const char *name; 1560 int res; 1561 1562 /* 1563 * If we have already found this symbol, get the information from 1564 * the cache. 1565 */ 1566 if (symnum >= refobj->dynsymcount) 1567 return NULL; /* Bad object */ 1568 if (cache != NULL && cache[symnum].sym != NULL) { 1569 *defobj_out = cache[symnum].obj; 1570 return cache[symnum].sym; 1571 } 1572 1573 ref = refobj->symtab + symnum; 1574 name = refobj->strtab + ref->st_name; 1575 def = NULL; 1576 defobj = NULL; 1577 1578 /* 1579 * We don't have to do a full scale lookup if the symbol is local. 1580 * We know it will bind to the instance in this load module; to 1581 * which we already have a pointer (ie ref). By not doing a lookup, 1582 * we not only improve performance, but it also avoids unresolvable 1583 * symbols when local symbols are not in the hash table. 1584 * 1585 * This might occur for TLS module relocations, which simply use 1586 * symbol 0. 1587 */ 1588 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1589 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1590 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1591 symnum); 1592 } 1593 symlook_init(&req, name); 1594 req.flags = flags; 1595 req.ventry = fetch_ventry(refobj, symnum); 1596 req.lockstate = lockstate; 1597 res = symlook_default(&req, refobj); 1598 if (res == 0) { 1599 def = req.sym_out; 1600 defobj = req.defobj_out; 1601 } 1602 } else { 1603 def = ref; 1604 defobj = refobj; 1605 } 1606 1607 /* 1608 * If we found no definition and the reference is weak, treat the 1609 * symbol as having the value zero. 1610 */ 1611 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1612 def = &sym_zero; 1613 defobj = obj_main; 1614 } 1615 1616 if (def != NULL) { 1617 *defobj_out = defobj; 1618 /* Record the information in the cache to avoid subsequent lookups. */ 1619 if (cache != NULL) { 1620 cache[symnum].sym = def; 1621 cache[symnum].obj = defobj; 1622 } 1623 } else { 1624 if (refobj != &obj_rtld) 1625 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1626 } 1627 return def; 1628 } 1629 1630 /* 1631 * Return the search path from the ldconfig hints file, reading it if 1632 * necessary. If nostdlib is true, then the default search paths are 1633 * not added to result. 1634 * 1635 * Returns NULL if there are problems with the hints file, 1636 * or if the search path there is empty. 1637 */ 1638 static const char * 1639 gethints(bool nostdlib) 1640 { 1641 static char *hints, *filtered_path; 1642 struct elfhints_hdr hdr; 1643 struct fill_search_info_args sargs, hargs; 1644 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1645 struct dl_serpath *SLPpath, *hintpath; 1646 char *p; 1647 unsigned int SLPndx, hintndx, fndx, fcount; 1648 int fd; 1649 size_t flen; 1650 bool skip; 1651 1652 /* First call, read the hints file */ 1653 if (hints == NULL) { 1654 /* Keep from trying again in case the hints file is bad. */ 1655 hints = ""; 1656 1657 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1658 return (NULL); 1659 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1660 hdr.magic != ELFHINTS_MAGIC || 1661 hdr.version != 1) { 1662 close(fd); 1663 return (NULL); 1664 } 1665 p = xmalloc(hdr.dirlistlen + 1); 1666 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1667 read(fd, p, hdr.dirlistlen + 1) != 1668 (ssize_t)hdr.dirlistlen + 1) { 1669 free(p); 1670 close(fd); 1671 return (NULL); 1672 } 1673 hints = p; 1674 close(fd); 1675 } 1676 1677 /* 1678 * If caller agreed to receive list which includes the default 1679 * paths, we are done. Otherwise, if we still have not 1680 * calculated filtered result, do it now. 1681 */ 1682 if (!nostdlib) 1683 return (hints[0] != '\0' ? hints : NULL); 1684 if (filtered_path != NULL) 1685 goto filt_ret; 1686 1687 /* 1688 * Obtain the list of all configured search paths, and the 1689 * list of the default paths. 1690 * 1691 * First estimate the size of the results. 1692 */ 1693 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1694 smeta.dls_cnt = 0; 1695 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1696 hmeta.dls_cnt = 0; 1697 1698 sargs.request = RTLD_DI_SERINFOSIZE; 1699 sargs.serinfo = &smeta; 1700 hargs.request = RTLD_DI_SERINFOSIZE; 1701 hargs.serinfo = &hmeta; 1702 1703 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1704 path_enumerate(p, fill_search_info, &hargs); 1705 1706 SLPinfo = xmalloc(smeta.dls_size); 1707 hintinfo = xmalloc(hmeta.dls_size); 1708 1709 /* 1710 * Next fetch both sets of paths. 1711 */ 1712 sargs.request = RTLD_DI_SERINFO; 1713 sargs.serinfo = SLPinfo; 1714 sargs.serpath = &SLPinfo->dls_serpath[0]; 1715 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1716 1717 hargs.request = RTLD_DI_SERINFO; 1718 hargs.serinfo = hintinfo; 1719 hargs.serpath = &hintinfo->dls_serpath[0]; 1720 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1721 1722 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1723 path_enumerate(p, fill_search_info, &hargs); 1724 1725 /* 1726 * Now calculate the difference between two sets, by excluding 1727 * standard paths from the full set. 1728 */ 1729 fndx = 0; 1730 fcount = 0; 1731 filtered_path = xmalloc(hdr.dirlistlen + 1); 1732 hintpath = &hintinfo->dls_serpath[0]; 1733 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1734 skip = false; 1735 SLPpath = &SLPinfo->dls_serpath[0]; 1736 /* 1737 * Check each standard path against current. 1738 */ 1739 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1740 /* matched, skip the path */ 1741 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1742 skip = true; 1743 break; 1744 } 1745 } 1746 if (skip) 1747 continue; 1748 /* 1749 * Not matched against any standard path, add the path 1750 * to result. Separate consecutive paths with ':'. 1751 */ 1752 if (fcount > 0) { 1753 filtered_path[fndx] = ':'; 1754 fndx++; 1755 } 1756 fcount++; 1757 flen = strlen(hintpath->dls_name); 1758 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1759 fndx += flen; 1760 } 1761 filtered_path[fndx] = '\0'; 1762 1763 free(SLPinfo); 1764 free(hintinfo); 1765 1766 filt_ret: 1767 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1768 } 1769 1770 static void 1771 init_dag(Obj_Entry *root) 1772 { 1773 const Needed_Entry *needed; 1774 const Objlist_Entry *elm; 1775 DoneList donelist; 1776 1777 if (root->dag_inited) 1778 return; 1779 donelist_init(&donelist); 1780 1781 /* Root object belongs to own DAG. */ 1782 objlist_push_tail(&root->dldags, root); 1783 objlist_push_tail(&root->dagmembers, root); 1784 donelist_check(&donelist, root); 1785 1786 /* 1787 * Add dependencies of root object to DAG in breadth order 1788 * by exploiting the fact that each new object get added 1789 * to the tail of the dagmembers list. 1790 */ 1791 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1792 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1793 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1794 continue; 1795 objlist_push_tail(&needed->obj->dldags, root); 1796 objlist_push_tail(&root->dagmembers, needed->obj); 1797 } 1798 } 1799 root->dag_inited = true; 1800 } 1801 1802 static void 1803 process_nodelete(Obj_Entry *root) 1804 { 1805 const Objlist_Entry *elm; 1806 1807 /* 1808 * Walk over object DAG and process every dependent object that 1809 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1810 * which then should have its reference upped separately. 1811 */ 1812 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1813 if (elm->obj != NULL && elm->obj->z_nodelete && 1814 !elm->obj->ref_nodel) { 1815 dbg("obj %s nodelete", elm->obj->path); 1816 init_dag(elm->obj); 1817 ref_dag(elm->obj); 1818 elm->obj->ref_nodel = true; 1819 } 1820 } 1821 } 1822 1823 /* 1824 * Initialize the dynamic linker. The argument is the address at which 1825 * the dynamic linker has been mapped into memory. The primary task of 1826 * this function is to relocate the dynamic linker. 1827 */ 1828 static void 1829 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1830 { 1831 Obj_Entry objtmp; /* Temporary rtld object */ 1832 const Elf_Dyn *dyn_rpath; 1833 const Elf_Dyn *dyn_soname; 1834 const Elf_Dyn *dyn_runpath; 1835 1836 /* 1837 * Conjure up an Obj_Entry structure for the dynamic linker. 1838 * 1839 * The "path" member can't be initialized yet because string constants 1840 * cannot yet be accessed. Below we will set it correctly. 1841 */ 1842 memset(&objtmp, 0, sizeof(objtmp)); 1843 objtmp.path = NULL; 1844 objtmp.rtld = true; 1845 objtmp.mapbase = mapbase; 1846 #ifdef PIC 1847 objtmp.relocbase = mapbase; 1848 #endif 1849 if (RTLD_IS_DYNAMIC()) { 1850 objtmp.dynamic = rtld_dynamic(&objtmp); 1851 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1852 assert(objtmp.needed == NULL); 1853 assert(!objtmp.textrel); 1854 1855 /* 1856 * Temporarily put the dynamic linker entry into the object list, so 1857 * that symbols can be found. 1858 */ 1859 1860 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1861 } 1862 1863 /* Initialize the object list. */ 1864 obj_tail = &obj_list; 1865 1866 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1867 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1868 1869 #ifdef ENABLE_OSRELDATE 1870 if (aux_info[AT_OSRELDATE] != NULL) 1871 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1872 #endif 1873 1874 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1875 1876 /* Replace the path with a dynamically allocated copy. */ 1877 obj_rtld.path = xstrdup(PATH_RTLD); 1878 1879 r_debug.r_brk = r_debug_state; 1880 r_debug.r_state = RT_CONSISTENT; 1881 } 1882 1883 /* 1884 * Add the init functions from a needed object list (and its recursive 1885 * needed objects) to "list". This is not used directly; it is a helper 1886 * function for initlist_add_objects(). The write lock must be held 1887 * when this function is called. 1888 */ 1889 static void 1890 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1891 { 1892 /* Recursively process the successor needed objects. */ 1893 if (needed->next != NULL) 1894 initlist_add_neededs(needed->next, list); 1895 1896 /* Process the current needed object. */ 1897 if (needed->obj != NULL) 1898 initlist_add_objects(needed->obj, &needed->obj->next, list); 1899 } 1900 1901 /* 1902 * Scan all of the DAGs rooted in the range of objects from "obj" to 1903 * "tail" and add their init functions to "list". This recurses over 1904 * the DAGs and ensure the proper init ordering such that each object's 1905 * needed libraries are initialized before the object itself. At the 1906 * same time, this function adds the objects to the global finalization 1907 * list "list_fini" in the opposite order. The write lock must be 1908 * held when this function is called. 1909 */ 1910 static void 1911 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1912 { 1913 1914 if (obj->init_scanned || obj->init_done) 1915 return; 1916 obj->init_scanned = true; 1917 1918 /* Recursively process the successor objects. */ 1919 if (&obj->next != tail) 1920 initlist_add_objects(obj->next, tail, list); 1921 1922 /* Recursively process the needed objects. */ 1923 if (obj->needed != NULL) 1924 initlist_add_neededs(obj->needed, list); 1925 if (obj->needed_filtees != NULL) 1926 initlist_add_neededs(obj->needed_filtees, list); 1927 if (obj->needed_aux_filtees != NULL) 1928 initlist_add_neededs(obj->needed_aux_filtees, list); 1929 1930 /* Add the object to the init list. */ 1931 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1932 obj->init_array != (Elf_Addr)NULL) 1933 objlist_push_tail(list, obj); 1934 1935 /* Add the object to the global fini list in the reverse order. */ 1936 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1937 && !obj->on_fini_list) { 1938 objlist_push_head(&list_fini, obj); 1939 obj->on_fini_list = true; 1940 } 1941 } 1942 1943 #ifndef FPTR_TARGET 1944 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1945 #endif 1946 1947 static void 1948 free_needed_filtees(Needed_Entry *n) 1949 { 1950 Needed_Entry *needed, *needed1; 1951 1952 for (needed = n; needed != NULL; needed = needed->next) { 1953 if (needed->obj != NULL) { 1954 dlclose(needed->obj); 1955 needed->obj = NULL; 1956 } 1957 } 1958 for (needed = n; needed != NULL; needed = needed1) { 1959 needed1 = needed->next; 1960 free(needed); 1961 } 1962 } 1963 1964 static void 1965 unload_filtees(Obj_Entry *obj) 1966 { 1967 1968 free_needed_filtees(obj->needed_filtees); 1969 obj->needed_filtees = NULL; 1970 free_needed_filtees(obj->needed_aux_filtees); 1971 obj->needed_aux_filtees = NULL; 1972 obj->filtees_loaded = false; 1973 } 1974 1975 static void 1976 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1977 RtldLockState *lockstate) 1978 { 1979 1980 for (; needed != NULL; needed = needed->next) { 1981 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1982 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1983 RTLD_LOCAL, lockstate); 1984 } 1985 } 1986 1987 static void 1988 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1989 { 1990 1991 lock_restart_for_upgrade(lockstate); 1992 if (!obj->filtees_loaded) { 1993 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1994 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1995 obj->filtees_loaded = true; 1996 } 1997 } 1998 1999 static int 2000 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2001 { 2002 Obj_Entry *obj1; 2003 2004 for (; needed != NULL; needed = needed->next) { 2005 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2006 flags & ~RTLD_LO_NOLOAD); 2007 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2008 return (-1); 2009 } 2010 return (0); 2011 } 2012 2013 /* 2014 * Given a shared object, traverse its list of needed objects, and load 2015 * each of them. Returns 0 on success. Generates an error message and 2016 * returns -1 on failure. 2017 */ 2018 static int 2019 load_needed_objects(Obj_Entry *first, int flags) 2020 { 2021 Obj_Entry *obj; 2022 2023 for (obj = first; obj != NULL; obj = obj->next) { 2024 if (process_needed(obj, obj->needed, flags) == -1) 2025 return (-1); 2026 } 2027 return (0); 2028 } 2029 2030 static int 2031 load_preload_objects(void) 2032 { 2033 char *p = ld_preload; 2034 static const char delim[] = " \t:;"; 2035 2036 if (p == NULL) 2037 return 0; 2038 2039 p += strspn(p, delim); 2040 while (*p != '\0') { 2041 size_t len = strcspn(p, delim); 2042 char savech; 2043 Obj_Entry *obj; 2044 SymLook req; 2045 int res; 2046 2047 savech = p[len]; 2048 p[len] = '\0'; 2049 obj = load_object(p, -1, NULL, 0); 2050 if (obj == NULL) 2051 return -1; /* XXX - cleanup */ 2052 p[len] = savech; 2053 p += len; 2054 p += strspn(p, delim); 2055 2056 /* Check for the magic tracing function */ 2057 symlook_init(&req, RTLD_FUNCTRACE); 2058 res = symlook_obj(&req, obj); 2059 if (res == 0) { 2060 rtld_functrace = (void *)(req.defobj_out->relocbase + 2061 req.sym_out->st_value); 2062 rtld_functrace_obj = req.defobj_out; 2063 } 2064 } 2065 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2066 return 0; 2067 } 2068 2069 static const char * 2070 printable_path(const char *path) 2071 { 2072 2073 return (path == NULL ? "<unknown>" : path); 2074 } 2075 2076 /* 2077 * Load a shared object into memory, if it is not already loaded. The 2078 * object may be specified by name or by user-supplied file descriptor 2079 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2080 * duplicate is. 2081 * 2082 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2083 * on failure. 2084 */ 2085 static Obj_Entry * 2086 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2087 { 2088 Obj_Entry *obj; 2089 int fd; 2090 struct stat sb; 2091 char *path; 2092 2093 if (name != NULL) { 2094 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2095 if (object_match_name(obj, name)) 2096 return (obj); 2097 } 2098 2099 path = find_library(name, refobj); 2100 if (path == NULL) 2101 return (NULL); 2102 } else 2103 path = NULL; 2104 2105 /* 2106 * If we didn't find a match by pathname, or the name is not 2107 * supplied, open the file and check again by device and inode. 2108 * This avoids false mismatches caused by multiple links or ".." 2109 * in pathnames. 2110 * 2111 * To avoid a race, we open the file and use fstat() rather than 2112 * using stat(). 2113 */ 2114 fd = -1; 2115 if (fd_u == -1) { 2116 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2117 _rtld_error("Cannot open \"%s\"", path); 2118 free(path); 2119 return (NULL); 2120 } 2121 } else { 2122 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2123 if (fd == -1) { 2124 /* 2125 * Temporary, remove at 3.6 branch 2126 * User might not have latest kernel installed 2127 * so fall back to old command for a while 2128 */ 2129 fd = dup(fd_u); 2130 if (fd == -1 || (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)) { 2131 _rtld_error("Cannot dup fd"); 2132 free(path); 2133 return (NULL); 2134 } 2135 } 2136 } 2137 if (fstat(fd, &sb) == -1) { 2138 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2139 close(fd); 2140 free(path); 2141 return NULL; 2142 } 2143 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2144 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2145 break; 2146 if (obj != NULL && name != NULL) { 2147 object_add_name(obj, name); 2148 free(path); 2149 close(fd); 2150 return obj; 2151 } 2152 if (flags & RTLD_LO_NOLOAD) { 2153 free(path); 2154 close(fd); 2155 return (NULL); 2156 } 2157 2158 /* First use of this object, so we must map it in */ 2159 obj = do_load_object(fd, name, path, &sb, flags); 2160 if (obj == NULL) 2161 free(path); 2162 close(fd); 2163 2164 return obj; 2165 } 2166 2167 static Obj_Entry * 2168 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2169 int flags) 2170 { 2171 Obj_Entry *obj; 2172 struct statfs fs; 2173 2174 /* 2175 * but first, make sure that environment variables haven't been 2176 * used to circumvent the noexec flag on a filesystem. 2177 */ 2178 if (dangerous_ld_env) { 2179 if (fstatfs(fd, &fs) != 0) { 2180 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2181 return NULL; 2182 } 2183 if (fs.f_flags & MNT_NOEXEC) { 2184 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2185 return NULL; 2186 } 2187 } 2188 dbg("loading \"%s\"", printable_path(path)); 2189 obj = map_object(fd, printable_path(path), sbp); 2190 if (obj == NULL) 2191 return NULL; 2192 2193 /* 2194 * If DT_SONAME is present in the object, digest_dynamic2 already 2195 * added it to the object names. 2196 */ 2197 if (name != NULL) 2198 object_add_name(obj, name); 2199 obj->path = path; 2200 digest_dynamic(obj, 0); 2201 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2202 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2203 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2204 RTLD_LO_DLOPEN) { 2205 dbg("refusing to load non-loadable \"%s\"", obj->path); 2206 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2207 munmap(obj->mapbase, obj->mapsize); 2208 obj_free(obj); 2209 return (NULL); 2210 } 2211 2212 *obj_tail = obj; 2213 obj_tail = &obj->next; 2214 obj_count++; 2215 obj_loads++; 2216 linkmap_add(obj); /* for GDB & dlinfo() */ 2217 max_stack_flags |= obj->stack_flags; 2218 2219 dbg(" %p .. %p: %s", obj->mapbase, 2220 obj->mapbase + obj->mapsize - 1, obj->path); 2221 if (obj->textrel) 2222 dbg(" WARNING: %s has impure text", obj->path); 2223 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2224 obj->path); 2225 2226 return obj; 2227 } 2228 2229 static Obj_Entry * 2230 obj_from_addr(const void *addr) 2231 { 2232 Obj_Entry *obj; 2233 2234 for (obj = obj_list; obj != NULL; obj = obj->next) { 2235 if (addr < (void *) obj->mapbase) 2236 continue; 2237 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2238 return obj; 2239 } 2240 return NULL; 2241 } 2242 2243 /* 2244 * If the main program is defined with a .preinit_array section, call 2245 * each function in order. This must occur before the initialization 2246 * of any shared object or the main program. 2247 */ 2248 static void 2249 preinit_main(void) 2250 { 2251 Elf_Addr *preinit_addr; 2252 int index; 2253 2254 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2255 if (preinit_addr == NULL) 2256 return; 2257 2258 for (index = 0; index < obj_main->preinit_array_num; index++) { 2259 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2260 dbg("calling preinit function for %s at %p", obj_main->path, 2261 (void *)preinit_addr[index]); 2262 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2263 0, 0, obj_main->path); 2264 call_init_pointer(obj_main, preinit_addr[index]); 2265 } 2266 } 2267 } 2268 2269 /* 2270 * Call the finalization functions for each of the objects in "list" 2271 * belonging to the DAG of "root" and referenced once. If NULL "root" 2272 * is specified, every finalization function will be called regardless 2273 * of the reference count and the list elements won't be freed. All of 2274 * the objects are expected to have non-NULL fini functions. 2275 */ 2276 static void 2277 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2278 { 2279 Objlist_Entry *elm; 2280 char *saved_msg; 2281 Elf_Addr *fini_addr; 2282 int index; 2283 2284 assert(root == NULL || root->refcount == 1); 2285 2286 /* 2287 * Preserve the current error message since a fini function might 2288 * call into the dynamic linker and overwrite it. 2289 */ 2290 saved_msg = errmsg_save(); 2291 do { 2292 STAILQ_FOREACH(elm, list, link) { 2293 if (root != NULL && (elm->obj->refcount != 1 || 2294 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2295 continue; 2296 2297 /* Remove object from fini list to prevent recursive invocation. */ 2298 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2299 /* 2300 * XXX: If a dlopen() call references an object while the 2301 * fini function is in progress, we might end up trying to 2302 * unload the referenced object in dlclose() or the object 2303 * won't be unloaded although its fini function has been 2304 * called. 2305 */ 2306 lock_release(rtld_bind_lock, lockstate); 2307 2308 /* 2309 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. When this 2310 * happens, DT_FINI_ARRAY is processed first, and it is also processed 2311 * backwards. It is possible to encounter DT_FINI_ARRAY elements with 2312 * values of 0 or 1, but they need to be ignored. 2313 */ 2314 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2315 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2316 for (index = elm->obj->fini_array_num - 1; index >= 0; index--) { 2317 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2318 dbg("calling fini array function for %s at %p", 2319 elm->obj->path, (void *)fini_addr[index]); 2320 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2321 (void *)fini_addr[index], 0, 0, elm->obj->path); 2322 call_initfini_pointer(elm->obj, fini_addr[index]); 2323 } 2324 } 2325 } 2326 if (elm->obj->fini != (Elf_Addr)NULL) { 2327 dbg("calling fini function for %s at %p", elm->obj->path, 2328 (void *)elm->obj->fini); 2329 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2330 0, 0, elm->obj->path); 2331 call_initfini_pointer(elm->obj, elm->obj->fini); 2332 } 2333 wlock_acquire(rtld_bind_lock, lockstate); 2334 /* No need to free anything if process is going down. */ 2335 if (root != NULL) 2336 free(elm); 2337 /* 2338 * We must restart the list traversal after every fini call 2339 * because a dlclose() call from the fini function or from 2340 * another thread might have modified the reference counts. 2341 */ 2342 break; 2343 } 2344 } while (elm != NULL); 2345 errmsg_restore(saved_msg); 2346 } 2347 2348 /* 2349 * Call the initialization functions for each of the objects in 2350 * "list". All of the objects are expected to have non-NULL init 2351 * functions. 2352 */ 2353 static void 2354 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2355 { 2356 Objlist_Entry *elm; 2357 Obj_Entry *obj; 2358 char *saved_msg; 2359 Elf_Addr *init_addr; 2360 int index; 2361 2362 /* 2363 * Clean init_scanned flag so that objects can be rechecked and 2364 * possibly initialized earlier if any of vectors called below 2365 * cause the change by using dlopen. 2366 */ 2367 for (obj = obj_list; obj != NULL; obj = obj->next) 2368 obj->init_scanned = false; 2369 2370 /* 2371 * Preserve the current error message since an init function might 2372 * call into the dynamic linker and overwrite it. 2373 */ 2374 saved_msg = errmsg_save(); 2375 STAILQ_FOREACH(elm, list, link) { 2376 if (elm->obj->init_done) /* Initialized early. */ 2377 continue; 2378 2379 /* 2380 * Race: other thread might try to use this object before current 2381 * one completes the initilization. Not much can be done here 2382 * without better locking. 2383 */ 2384 elm->obj->init_done = true; 2385 lock_release(rtld_bind_lock, lockstate); 2386 2387 /* 2388 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. When 2389 * this happens, DT_INIT is processed first. It is possible to 2390 * encounter DT_INIT_ARRAY elements with values of 0 or 1, but they 2391 * need to be ignored. 2392 */ 2393 if (elm->obj->init != (Elf_Addr)NULL) { 2394 dbg("calling init function for %s at %p", elm->obj->path, 2395 (void *)elm->obj->init); 2396 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2397 0, 0, elm->obj->path); 2398 call_initfini_pointer(elm->obj, elm->obj->init); 2399 } 2400 init_addr = (Elf_Addr *)elm->obj->init_array; 2401 if (init_addr != NULL) { 2402 for (index = 0; index < elm->obj->init_array_num; index++) { 2403 if (init_addr[index] != 0 && init_addr[index] != 1) { 2404 dbg("calling init array function for %s at %p", elm->obj->path, 2405 (void *)init_addr[index]); 2406 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2407 (void *)init_addr[index], 0, 0, elm->obj->path); 2408 call_init_pointer(elm->obj, init_addr[index]); 2409 } 2410 } 2411 } 2412 wlock_acquire(rtld_bind_lock, lockstate); 2413 } 2414 errmsg_restore(saved_msg); 2415 } 2416 2417 static void 2418 objlist_clear(Objlist *list) 2419 { 2420 Objlist_Entry *elm; 2421 2422 while (!STAILQ_EMPTY(list)) { 2423 elm = STAILQ_FIRST(list); 2424 STAILQ_REMOVE_HEAD(list, link); 2425 free(elm); 2426 } 2427 } 2428 2429 static Objlist_Entry * 2430 objlist_find(Objlist *list, const Obj_Entry *obj) 2431 { 2432 Objlist_Entry *elm; 2433 2434 STAILQ_FOREACH(elm, list, link) 2435 if (elm->obj == obj) 2436 return elm; 2437 return NULL; 2438 } 2439 2440 static void 2441 objlist_init(Objlist *list) 2442 { 2443 STAILQ_INIT(list); 2444 } 2445 2446 static void 2447 objlist_push_head(Objlist *list, Obj_Entry *obj) 2448 { 2449 Objlist_Entry *elm; 2450 2451 elm = NEW(Objlist_Entry); 2452 elm->obj = obj; 2453 STAILQ_INSERT_HEAD(list, elm, link); 2454 } 2455 2456 static void 2457 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2458 { 2459 Objlist_Entry *elm; 2460 2461 elm = NEW(Objlist_Entry); 2462 elm->obj = obj; 2463 STAILQ_INSERT_TAIL(list, elm, link); 2464 } 2465 2466 static void 2467 objlist_remove(Objlist *list, Obj_Entry *obj) 2468 { 2469 Objlist_Entry *elm; 2470 2471 if ((elm = objlist_find(list, obj)) != NULL) { 2472 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2473 free(elm); 2474 } 2475 } 2476 2477 /* 2478 * Relocate dag rooted in the specified object. 2479 * Returns 0 on success, or -1 on failure. 2480 */ 2481 2482 static int 2483 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2484 int flags, RtldLockState *lockstate) 2485 { 2486 Objlist_Entry *elm; 2487 int error; 2488 2489 error = 0; 2490 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2491 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2492 lockstate); 2493 if (error == -1) 2494 break; 2495 } 2496 return (error); 2497 } 2498 2499 /* 2500 * Relocate single object. 2501 * Returns 0 on success, or -1 on failure. 2502 */ 2503 static int 2504 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2505 int flags, RtldLockState *lockstate) 2506 { 2507 2508 if (obj->relocated) 2509 return (0); 2510 obj->relocated = true; 2511 if (obj != rtldobj) 2512 dbg("relocating \"%s\"", obj->path); 2513 2514 if (obj->symtab == NULL || obj->strtab == NULL || 2515 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2516 _rtld_error("%s: Shared object has no run-time symbol table", 2517 obj->path); 2518 return (-1); 2519 } 2520 2521 if (obj->textrel) { 2522 /* There are relocations to the write-protected text segment. */ 2523 if (mprotect(obj->mapbase, obj->textsize, 2524 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2525 _rtld_error("%s: Cannot write-enable text segment: %s", 2526 obj->path, rtld_strerror(errno)); 2527 return (-1); 2528 } 2529 } 2530 2531 /* Process the non-PLT relocations. */ 2532 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2533 return (-1); 2534 2535 /* 2536 * Reprotect the text segment. Make sure it is included in the 2537 * core dump since we modified it. This unfortunately causes the 2538 * entire text segment to core-out but we don't have much of a 2539 * choice. We could try to only reenable core dumps on pages 2540 * in which relocations occured but that is likely most of the text 2541 * pages anyway, and even that would not work because the rest of 2542 * the text pages would wind up as a read-only OBJT_DEFAULT object 2543 * (created due to our modifications) backed by the original OBJT_VNODE 2544 * object, and the ELF coredump code is currently only able to dump 2545 * vnode records for pure vnode-backed mappings, not vnode backings 2546 * to memory objects. 2547 */ 2548 if (obj->textrel) { 2549 madvise(obj->mapbase, obj->textsize, MADV_CORE); 2550 if (mprotect(obj->mapbase, obj->textsize, 2551 PROT_READ|PROT_EXEC) == -1) { 2552 _rtld_error("%s: Cannot write-protect text segment: %s", 2553 obj->path, rtld_strerror(errno)); 2554 return (-1); 2555 } 2556 } 2557 2558 2559 /* Set the special PLT or GOT entries. */ 2560 init_pltgot(obj); 2561 2562 /* Process the PLT relocations. */ 2563 if (reloc_plt(obj) == -1) 2564 return (-1); 2565 /* Relocate the jump slots if we are doing immediate binding. */ 2566 if (obj->bind_now || bind_now) 2567 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2568 return (-1); 2569 2570 /* 2571 * Set up the magic number and version in the Obj_Entry. These 2572 * were checked in the crt1.o from the original ElfKit, so we 2573 * set them for backward compatibility. 2574 */ 2575 obj->magic = RTLD_MAGIC; 2576 obj->version = RTLD_VERSION; 2577 2578 /* 2579 * Set relocated data to read-only status if protection specified 2580 */ 2581 2582 if (obj->relro_size) { 2583 if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) { 2584 _rtld_error("%s: Cannot enforce relro relocation: %s", 2585 obj->path, rtld_strerror(errno)); 2586 return (-1); 2587 } 2588 } 2589 return (0); 2590 } 2591 2592 /* 2593 * Relocate newly-loaded shared objects. The argument is a pointer to 2594 * the Obj_Entry for the first such object. All objects from the first 2595 * to the end of the list of objects are relocated. Returns 0 on success, 2596 * or -1 on failure. 2597 */ 2598 static int 2599 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2600 int flags, RtldLockState *lockstate) 2601 { 2602 Obj_Entry *obj; 2603 int error; 2604 2605 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2606 error = relocate_object(obj, bind_now, rtldobj, flags, 2607 lockstate); 2608 if (error == -1) 2609 break; 2610 } 2611 return (error); 2612 } 2613 2614 /* 2615 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2616 * referencing STT_GNU_IFUNC symbols is postponed till the other 2617 * relocations are done. The indirect functions specified as 2618 * ifunc are allowed to call other symbols, so we need to have 2619 * objects relocated before asking for resolution from indirects. 2620 * 2621 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2622 * instead of the usual lazy handling of PLT slots. It is 2623 * consistent with how GNU does it. 2624 */ 2625 static int 2626 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2627 RtldLockState *lockstate) 2628 { 2629 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2630 return (-1); 2631 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2632 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2633 return (-1); 2634 return (0); 2635 } 2636 2637 static int 2638 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2639 RtldLockState *lockstate) 2640 { 2641 Obj_Entry *obj; 2642 2643 for (obj = first; obj != NULL; obj = obj->next) { 2644 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2645 return (-1); 2646 } 2647 return (0); 2648 } 2649 2650 static int 2651 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2652 RtldLockState *lockstate) 2653 { 2654 Objlist_Entry *elm; 2655 2656 STAILQ_FOREACH(elm, list, link) { 2657 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2658 lockstate) == -1) 2659 return (-1); 2660 } 2661 return (0); 2662 } 2663 2664 /* 2665 * Cleanup procedure. It will be called (by the atexit mechanism) just 2666 * before the process exits. 2667 */ 2668 static void 2669 rtld_exit(void) 2670 { 2671 RtldLockState lockstate; 2672 2673 wlock_acquire(rtld_bind_lock, &lockstate); 2674 dbg("rtld_exit()"); 2675 objlist_call_fini(&list_fini, NULL, &lockstate); 2676 /* No need to remove the items from the list, since we are exiting. */ 2677 if (!libmap_disable) 2678 lm_fini(); 2679 lock_release(rtld_bind_lock, &lockstate); 2680 } 2681 2682 static void * 2683 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2684 { 2685 if (path == NULL) 2686 return (NULL); 2687 2688 path += strspn(path, ":;"); 2689 while (*path != '\0') { 2690 size_t len; 2691 char *res; 2692 2693 len = strcspn(path, ":;"); 2694 res = callback(path, len, arg); 2695 2696 if (res != NULL) 2697 return (res); 2698 2699 path += len; 2700 path += strspn(path, ":;"); 2701 } 2702 2703 return (NULL); 2704 } 2705 2706 struct try_library_args { 2707 const char *name; 2708 size_t namelen; 2709 char *buffer; 2710 size_t buflen; 2711 }; 2712 2713 static void * 2714 try_library_path(const char *dir, size_t dirlen, void *param) 2715 { 2716 struct try_library_args *arg; 2717 2718 arg = param; 2719 if (*dir == '/' || trust) { 2720 char *pathname; 2721 2722 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2723 return (NULL); 2724 2725 pathname = arg->buffer; 2726 strncpy(pathname, dir, dirlen); 2727 pathname[dirlen] = '/'; 2728 strcpy(pathname + dirlen + 1, arg->name); 2729 2730 dbg(" Trying \"%s\"", pathname); 2731 if (access(pathname, F_OK) == 0) { /* We found it */ 2732 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2733 strcpy(pathname, arg->buffer); 2734 return (pathname); 2735 } 2736 } 2737 return (NULL); 2738 } 2739 2740 static char * 2741 search_library_path(const char *name, const char *path) 2742 { 2743 char *p; 2744 struct try_library_args arg; 2745 2746 if (path == NULL) 2747 return NULL; 2748 2749 arg.name = name; 2750 arg.namelen = strlen(name); 2751 arg.buffer = xmalloc(PATH_MAX); 2752 arg.buflen = PATH_MAX; 2753 2754 p = path_enumerate(path, try_library_path, &arg); 2755 2756 free(arg.buffer); 2757 2758 return (p); 2759 } 2760 2761 int 2762 dlclose(void *handle) 2763 { 2764 Obj_Entry *root; 2765 RtldLockState lockstate; 2766 2767 wlock_acquire(rtld_bind_lock, &lockstate); 2768 root = dlcheck(handle); 2769 if (root == NULL) { 2770 lock_release(rtld_bind_lock, &lockstate); 2771 return -1; 2772 } 2773 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2774 root->path); 2775 2776 /* Unreference the object and its dependencies. */ 2777 root->dl_refcount--; 2778 2779 if (root->refcount == 1) { 2780 /* 2781 * The object will be no longer referenced, so we must unload it. 2782 * First, call the fini functions. 2783 */ 2784 objlist_call_fini(&list_fini, root, &lockstate); 2785 2786 unref_dag(root); 2787 2788 /* Finish cleaning up the newly-unreferenced objects. */ 2789 GDB_STATE(RT_DELETE,&root->linkmap); 2790 unload_object(root); 2791 GDB_STATE(RT_CONSISTENT,NULL); 2792 } else 2793 unref_dag(root); 2794 2795 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2796 lock_release(rtld_bind_lock, &lockstate); 2797 return 0; 2798 } 2799 2800 char * 2801 dlerror(void) 2802 { 2803 char *msg = error_message; 2804 error_message = NULL; 2805 return msg; 2806 } 2807 2808 void * 2809 dlopen(const char *name, int mode) 2810 { 2811 2812 return (rtld_dlopen(name, -1, mode)); 2813 } 2814 2815 void * 2816 fdlopen(int fd, int mode) 2817 { 2818 2819 return (rtld_dlopen(NULL, fd, mode)); 2820 } 2821 2822 static void * 2823 rtld_dlopen(const char *name, int fd, int mode) 2824 { 2825 RtldLockState lockstate; 2826 int lo_flags; 2827 2828 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2829 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2830 if (ld_tracing != NULL) { 2831 rlock_acquire(rtld_bind_lock, &lockstate); 2832 if (sigsetjmp(lockstate.env, 0) != 0) 2833 lock_upgrade(rtld_bind_lock, &lockstate); 2834 environ = (char **)*get_program_var_addr("environ", &lockstate); 2835 lock_release(rtld_bind_lock, &lockstate); 2836 } 2837 lo_flags = RTLD_LO_DLOPEN; 2838 if (mode & RTLD_NODELETE) 2839 lo_flags |= RTLD_LO_NODELETE; 2840 if (mode & RTLD_NOLOAD) 2841 lo_flags |= RTLD_LO_NOLOAD; 2842 if (ld_tracing != NULL) 2843 lo_flags |= RTLD_LO_TRACE; 2844 2845 return (dlopen_object(name, fd, obj_main, lo_flags, 2846 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2847 } 2848 2849 static void 2850 dlopen_cleanup(Obj_Entry *obj) 2851 { 2852 2853 obj->dl_refcount--; 2854 unref_dag(obj); 2855 if (obj->refcount == 0) 2856 unload_object(obj); 2857 } 2858 2859 static Obj_Entry * 2860 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2861 int mode, RtldLockState *lockstate) 2862 { 2863 Obj_Entry **old_obj_tail; 2864 Obj_Entry *obj; 2865 Objlist initlist; 2866 RtldLockState mlockstate; 2867 int result; 2868 2869 objlist_init(&initlist); 2870 2871 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2872 wlock_acquire(rtld_bind_lock, &mlockstate); 2873 lockstate = &mlockstate; 2874 } 2875 GDB_STATE(RT_ADD,NULL); 2876 2877 old_obj_tail = obj_tail; 2878 obj = NULL; 2879 if (name == NULL && fd == -1) { 2880 obj = obj_main; 2881 obj->refcount++; 2882 } else { 2883 obj = load_object(name, fd, refobj, lo_flags); 2884 } 2885 2886 if (obj) { 2887 obj->dl_refcount++; 2888 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2889 objlist_push_tail(&list_global, obj); 2890 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2891 assert(*old_obj_tail == obj); 2892 result = load_needed_objects(obj, 2893 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2894 init_dag(obj); 2895 ref_dag(obj); 2896 if (result != -1) 2897 result = rtld_verify_versions(&obj->dagmembers); 2898 if (result != -1 && ld_tracing) 2899 goto trace; 2900 if (result == -1 || relocate_object_dag(obj, 2901 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2902 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2903 lockstate) == -1) { 2904 dlopen_cleanup(obj); 2905 obj = NULL; 2906 } else if (lo_flags & RTLD_LO_EARLY) { 2907 /* 2908 * Do not call the init functions for early loaded 2909 * filtees. The image is still not initialized enough 2910 * for them to work. 2911 * 2912 * Our object is found by the global object list and 2913 * will be ordered among all init calls done right 2914 * before transferring control to main. 2915 */ 2916 } else { 2917 /* Make list of init functions to call. */ 2918 initlist_add_objects(obj, &obj->next, &initlist); 2919 } 2920 /* 2921 * Process all no_delete objects here, given them own 2922 * DAGs to prevent their dependencies from being unloaded. 2923 * This has to be done after we have loaded all of the 2924 * dependencies, so that we do not miss any. 2925 */ 2926 if (obj != NULL) 2927 process_nodelete(obj); 2928 } else { 2929 /* 2930 * Bump the reference counts for objects on this DAG. If 2931 * this is the first dlopen() call for the object that was 2932 * already loaded as a dependency, initialize the dag 2933 * starting at it. 2934 */ 2935 init_dag(obj); 2936 ref_dag(obj); 2937 2938 if ((lo_flags & RTLD_LO_TRACE) != 0) 2939 goto trace; 2940 } 2941 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2942 obj->z_nodelete) && !obj->ref_nodel) { 2943 dbg("obj %s nodelete", obj->path); 2944 ref_dag(obj); 2945 obj->z_nodelete = obj->ref_nodel = true; 2946 } 2947 } 2948 2949 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2950 name); 2951 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2952 2953 if (!(lo_flags & RTLD_LO_EARLY)) { 2954 map_stacks_exec(lockstate); 2955 } 2956 2957 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2958 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2959 lockstate) == -1) { 2960 objlist_clear(&initlist); 2961 dlopen_cleanup(obj); 2962 if (lockstate == &mlockstate) 2963 lock_release(rtld_bind_lock, lockstate); 2964 return (NULL); 2965 } 2966 2967 if (!(lo_flags & RTLD_LO_EARLY)) { 2968 /* Call the init functions. */ 2969 objlist_call_init(&initlist, lockstate); 2970 } 2971 objlist_clear(&initlist); 2972 if (lockstate == &mlockstate) 2973 lock_release(rtld_bind_lock, lockstate); 2974 return obj; 2975 trace: 2976 trace_loaded_objects(obj); 2977 if (lockstate == &mlockstate) 2978 lock_release(rtld_bind_lock, lockstate); 2979 exit(0); 2980 } 2981 2982 static void * 2983 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2984 int flags) 2985 { 2986 DoneList donelist; 2987 const Obj_Entry *obj, *defobj; 2988 const Elf_Sym *def; 2989 SymLook req; 2990 RtldLockState lockstate; 2991 tls_index ti; 2992 int res; 2993 2994 def = NULL; 2995 defobj = NULL; 2996 symlook_init(&req, name); 2997 req.ventry = ve; 2998 req.flags = flags | SYMLOOK_IN_PLT; 2999 req.lockstate = &lockstate; 3000 3001 rlock_acquire(rtld_bind_lock, &lockstate); 3002 if (sigsetjmp(lockstate.env, 0) != 0) 3003 lock_upgrade(rtld_bind_lock, &lockstate); 3004 if (handle == NULL || handle == RTLD_NEXT || 3005 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3006 3007 if ((obj = obj_from_addr(retaddr)) == NULL) { 3008 _rtld_error("Cannot determine caller's shared object"); 3009 lock_release(rtld_bind_lock, &lockstate); 3010 return NULL; 3011 } 3012 if (handle == NULL) { /* Just the caller's shared object. */ 3013 res = symlook_obj(&req, obj); 3014 if (res == 0) { 3015 def = req.sym_out; 3016 defobj = req.defobj_out; 3017 } 3018 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3019 handle == RTLD_SELF) { /* ... caller included */ 3020 if (handle == RTLD_NEXT) 3021 obj = obj->next; 3022 for (; obj != NULL; obj = obj->next) { 3023 res = symlook_obj(&req, obj); 3024 if (res == 0) { 3025 if (def == NULL || 3026 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3027 def = req.sym_out; 3028 defobj = req.defobj_out; 3029 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3030 break; 3031 } 3032 } 3033 } 3034 /* 3035 * Search the dynamic linker itself, and possibly resolve the 3036 * symbol from there. This is how the application links to 3037 * dynamic linker services such as dlopen. 3038 */ 3039 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3040 res = symlook_obj(&req, &obj_rtld); 3041 if (res == 0) { 3042 def = req.sym_out; 3043 defobj = req.defobj_out; 3044 } 3045 } 3046 } else { 3047 assert(handle == RTLD_DEFAULT); 3048 res = symlook_default(&req, obj); 3049 if (res == 0) { 3050 defobj = req.defobj_out; 3051 def = req.sym_out; 3052 } 3053 } 3054 } else { 3055 if ((obj = dlcheck(handle)) == NULL) { 3056 lock_release(rtld_bind_lock, &lockstate); 3057 return NULL; 3058 } 3059 3060 donelist_init(&donelist); 3061 if (obj->mainprog) { 3062 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3063 res = symlook_global(&req, &donelist); 3064 if (res == 0) { 3065 def = req.sym_out; 3066 defobj = req.defobj_out; 3067 } 3068 /* 3069 * Search the dynamic linker itself, and possibly resolve the 3070 * symbol from there. This is how the application links to 3071 * dynamic linker services such as dlopen. 3072 */ 3073 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3074 res = symlook_obj(&req, &obj_rtld); 3075 if (res == 0) { 3076 def = req.sym_out; 3077 defobj = req.defobj_out; 3078 } 3079 } 3080 } 3081 else { 3082 /* Search the whole DAG rooted at the given object. */ 3083 res = symlook_list(&req, &obj->dagmembers, &donelist); 3084 if (res == 0) { 3085 def = req.sym_out; 3086 defobj = req.defobj_out; 3087 } 3088 } 3089 } 3090 3091 if (def != NULL) { 3092 lock_release(rtld_bind_lock, &lockstate); 3093 3094 /* 3095 * The value required by the caller is derived from the value 3096 * of the symbol. For the ia64 architecture, we need to 3097 * construct a function descriptor which the caller can use to 3098 * call the function with the right 'gp' value. For other 3099 * architectures and for non-functions, the value is simply 3100 * the relocated value of the symbol. 3101 */ 3102 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3103 return (make_function_pointer(def, defobj)); 3104 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3105 return (rtld_resolve_ifunc(defobj, def)); 3106 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3107 ti.ti_module = defobj->tlsindex; 3108 ti.ti_offset = def->st_value; 3109 return (__tls_get_addr(&ti)); 3110 } else 3111 return (defobj->relocbase + def->st_value); 3112 } 3113 3114 _rtld_error("Undefined symbol \"%s\"", name); 3115 lock_release(rtld_bind_lock, &lockstate); 3116 return NULL; 3117 } 3118 3119 void * 3120 dlsym(void *handle, const char *name) 3121 { 3122 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3123 SYMLOOK_DLSYM); 3124 } 3125 3126 dlfunc_t 3127 dlfunc(void *handle, const char *name) 3128 { 3129 union { 3130 void *d; 3131 dlfunc_t f; 3132 } rv; 3133 3134 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3135 SYMLOOK_DLSYM); 3136 return (rv.f); 3137 } 3138 3139 void * 3140 dlvsym(void *handle, const char *name, const char *version) 3141 { 3142 Ver_Entry ventry; 3143 3144 ventry.name = version; 3145 ventry.file = NULL; 3146 ventry.hash = elf_hash(version); 3147 ventry.flags= 0; 3148 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3149 SYMLOOK_DLSYM); 3150 } 3151 3152 int 3153 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3154 { 3155 const Obj_Entry *obj; 3156 RtldLockState lockstate; 3157 3158 rlock_acquire(rtld_bind_lock, &lockstate); 3159 obj = obj_from_addr(addr); 3160 if (obj == NULL) { 3161 _rtld_error("No shared object contains address"); 3162 lock_release(rtld_bind_lock, &lockstate); 3163 return (0); 3164 } 3165 rtld_fill_dl_phdr_info(obj, phdr_info); 3166 lock_release(rtld_bind_lock, &lockstate); 3167 return (1); 3168 } 3169 3170 int 3171 dladdr(const void *addr, Dl_info *info) 3172 { 3173 const Obj_Entry *obj; 3174 const Elf_Sym *def; 3175 void *symbol_addr; 3176 unsigned long symoffset; 3177 RtldLockState lockstate; 3178 3179 rlock_acquire(rtld_bind_lock, &lockstate); 3180 obj = obj_from_addr(addr); 3181 if (obj == NULL) { 3182 _rtld_error("No shared object contains address"); 3183 lock_release(rtld_bind_lock, &lockstate); 3184 return 0; 3185 } 3186 info->dli_fname = obj->path; 3187 info->dli_fbase = obj->mapbase; 3188 info->dli_saddr = NULL; 3189 info->dli_sname = NULL; 3190 3191 /* 3192 * Walk the symbol list looking for the symbol whose address is 3193 * closest to the address sent in. 3194 */ 3195 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3196 def = obj->symtab + symoffset; 3197 3198 /* 3199 * For skip the symbol if st_shndx is either SHN_UNDEF or 3200 * SHN_COMMON. 3201 */ 3202 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3203 continue; 3204 3205 /* 3206 * If the symbol is greater than the specified address, or if it 3207 * is further away from addr than the current nearest symbol, 3208 * then reject it. 3209 */ 3210 symbol_addr = obj->relocbase + def->st_value; 3211 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3212 continue; 3213 3214 /* Update our idea of the nearest symbol. */ 3215 info->dli_sname = obj->strtab + def->st_name; 3216 info->dli_saddr = symbol_addr; 3217 3218 /* Exact match? */ 3219 if (info->dli_saddr == addr) 3220 break; 3221 } 3222 lock_release(rtld_bind_lock, &lockstate); 3223 return 1; 3224 } 3225 3226 int 3227 dlinfo(void *handle, int request, void *p) 3228 { 3229 const Obj_Entry *obj; 3230 RtldLockState lockstate; 3231 int error; 3232 3233 rlock_acquire(rtld_bind_lock, &lockstate); 3234 3235 if (handle == NULL || handle == RTLD_SELF) { 3236 void *retaddr; 3237 3238 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3239 if ((obj = obj_from_addr(retaddr)) == NULL) 3240 _rtld_error("Cannot determine caller's shared object"); 3241 } else 3242 obj = dlcheck(handle); 3243 3244 if (obj == NULL) { 3245 lock_release(rtld_bind_lock, &lockstate); 3246 return (-1); 3247 } 3248 3249 error = 0; 3250 switch (request) { 3251 case RTLD_DI_LINKMAP: 3252 *((struct link_map const **)p) = &obj->linkmap; 3253 break; 3254 case RTLD_DI_ORIGIN: 3255 error = rtld_dirname(obj->path, p); 3256 break; 3257 3258 case RTLD_DI_SERINFOSIZE: 3259 case RTLD_DI_SERINFO: 3260 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3261 break; 3262 3263 default: 3264 _rtld_error("Invalid request %d passed to dlinfo()", request); 3265 error = -1; 3266 } 3267 3268 lock_release(rtld_bind_lock, &lockstate); 3269 3270 return (error); 3271 } 3272 3273 static void 3274 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3275 { 3276 3277 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3278 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 3279 STAILQ_FIRST(&obj->names)->name : obj->path; 3280 phdr_info->dlpi_phdr = obj->phdr; 3281 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3282 phdr_info->dlpi_tls_modid = obj->tlsindex; 3283 phdr_info->dlpi_tls_data = obj->tlsinit; 3284 phdr_info->dlpi_adds = obj_loads; 3285 phdr_info->dlpi_subs = obj_loads - obj_count; 3286 } 3287 3288 int 3289 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3290 { 3291 struct dl_phdr_info phdr_info; 3292 const Obj_Entry *obj; 3293 RtldLockState bind_lockstate, phdr_lockstate; 3294 int error; 3295 3296 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3297 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3298 3299 error = 0; 3300 3301 for (obj = obj_list; obj != NULL; obj = obj->next) { 3302 rtld_fill_dl_phdr_info(obj, &phdr_info); 3303 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3304 break; 3305 3306 } 3307 lock_release(rtld_bind_lock, &bind_lockstate); 3308 lock_release(rtld_phdr_lock, &phdr_lockstate); 3309 3310 return (error); 3311 } 3312 3313 static void * 3314 fill_search_info(const char *dir, size_t dirlen, void *param) 3315 { 3316 struct fill_search_info_args *arg; 3317 3318 arg = param; 3319 3320 if (arg->request == RTLD_DI_SERINFOSIZE) { 3321 arg->serinfo->dls_cnt ++; 3322 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3323 } else { 3324 struct dl_serpath *s_entry; 3325 3326 s_entry = arg->serpath; 3327 s_entry->dls_name = arg->strspace; 3328 s_entry->dls_flags = arg->flags; 3329 3330 strncpy(arg->strspace, dir, dirlen); 3331 arg->strspace[dirlen] = '\0'; 3332 3333 arg->strspace += dirlen + 1; 3334 arg->serpath++; 3335 } 3336 3337 return (NULL); 3338 } 3339 3340 static int 3341 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3342 { 3343 struct dl_serinfo _info; 3344 struct fill_search_info_args args; 3345 3346 args.request = RTLD_DI_SERINFOSIZE; 3347 args.serinfo = &_info; 3348 3349 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3350 _info.dls_cnt = 0; 3351 3352 path_enumerate(obj->rpath, fill_search_info, &args); 3353 path_enumerate(ld_library_path, fill_search_info, &args); 3354 path_enumerate(obj->runpath, fill_search_info, &args); 3355 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3356 if (!obj->z_nodeflib) 3357 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3358 3359 3360 if (request == RTLD_DI_SERINFOSIZE) { 3361 info->dls_size = _info.dls_size; 3362 info->dls_cnt = _info.dls_cnt; 3363 return (0); 3364 } 3365 3366 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3367 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3368 return (-1); 3369 } 3370 3371 args.request = RTLD_DI_SERINFO; 3372 args.serinfo = info; 3373 args.serpath = &info->dls_serpath[0]; 3374 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3375 3376 args.flags = LA_SER_RUNPATH; 3377 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3378 return (-1); 3379 3380 args.flags = LA_SER_LIBPATH; 3381 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3382 return (-1); 3383 3384 args.flags = LA_SER_RUNPATH; 3385 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3386 return (-1); 3387 3388 args.flags = LA_SER_CONFIG; 3389 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3390 != NULL) 3391 return (-1); 3392 3393 args.flags = LA_SER_DEFAULT; 3394 if (!obj->z_nodeflib && 3395 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3396 return (-1); 3397 return (0); 3398 } 3399 3400 static int 3401 rtld_dirname(const char *path, char *bname) 3402 { 3403 const char *endp; 3404 3405 /* Empty or NULL string gets treated as "." */ 3406 if (path == NULL || *path == '\0') { 3407 bname[0] = '.'; 3408 bname[1] = '\0'; 3409 return (0); 3410 } 3411 3412 /* Strip trailing slashes */ 3413 endp = path + strlen(path) - 1; 3414 while (endp > path && *endp == '/') 3415 endp--; 3416 3417 /* Find the start of the dir */ 3418 while (endp > path && *endp != '/') 3419 endp--; 3420 3421 /* Either the dir is "/" or there are no slashes */ 3422 if (endp == path) { 3423 bname[0] = *endp == '/' ? '/' : '.'; 3424 bname[1] = '\0'; 3425 return (0); 3426 } else { 3427 do { 3428 endp--; 3429 } while (endp > path && *endp == '/'); 3430 } 3431 3432 if (endp - path + 2 > PATH_MAX) 3433 { 3434 _rtld_error("Filename is too long: %s", path); 3435 return(-1); 3436 } 3437 3438 strncpy(bname, path, endp - path + 1); 3439 bname[endp - path + 1] = '\0'; 3440 return (0); 3441 } 3442 3443 static int 3444 rtld_dirname_abs(const char *path, char *base) 3445 { 3446 char base_rel[PATH_MAX]; 3447 3448 if (rtld_dirname(path, base) == -1) 3449 return (-1); 3450 if (base[0] == '/') 3451 return (0); 3452 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3453 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3454 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3455 return (-1); 3456 strcpy(base, base_rel); 3457 return (0); 3458 } 3459 3460 static void 3461 linkmap_add(Obj_Entry *obj) 3462 { 3463 struct link_map *l = &obj->linkmap; 3464 struct link_map *prev; 3465 3466 obj->linkmap.l_name = obj->path; 3467 obj->linkmap.l_addr = obj->mapbase; 3468 obj->linkmap.l_ld = obj->dynamic; 3469 #ifdef __mips__ 3470 /* GDB needs load offset on MIPS to use the symbols */ 3471 obj->linkmap.l_offs = obj->relocbase; 3472 #endif 3473 3474 if (r_debug.r_map == NULL) { 3475 r_debug.r_map = l; 3476 return; 3477 } 3478 3479 /* 3480 * Scan to the end of the list, but not past the entry for the 3481 * dynamic linker, which we want to keep at the very end. 3482 */ 3483 for (prev = r_debug.r_map; 3484 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3485 prev = prev->l_next) 3486 ; 3487 3488 /* Link in the new entry. */ 3489 l->l_prev = prev; 3490 l->l_next = prev->l_next; 3491 if (l->l_next != NULL) 3492 l->l_next->l_prev = l; 3493 prev->l_next = l; 3494 } 3495 3496 static void 3497 linkmap_delete(Obj_Entry *obj) 3498 { 3499 struct link_map *l = &obj->linkmap; 3500 3501 if (l->l_prev == NULL) { 3502 if ((r_debug.r_map = l->l_next) != NULL) 3503 l->l_next->l_prev = NULL; 3504 return; 3505 } 3506 3507 if ((l->l_prev->l_next = l->l_next) != NULL) 3508 l->l_next->l_prev = l->l_prev; 3509 } 3510 3511 /* 3512 * Function for the debugger to set a breakpoint on to gain control. 3513 * 3514 * The two parameters allow the debugger to easily find and determine 3515 * what the runtime loader is doing and to whom it is doing it. 3516 * 3517 * When the loadhook trap is hit (r_debug_state, set at program 3518 * initialization), the arguments can be found on the stack: 3519 * 3520 * +8 struct link_map *m 3521 * +4 struct r_debug *rd 3522 * +0 RetAddr 3523 */ 3524 void 3525 r_debug_state(struct r_debug* rd, struct link_map *m) 3526 { 3527 /* 3528 * The following is a hack to force the compiler to emit calls to 3529 * this function, even when optimizing. If the function is empty, 3530 * the compiler is not obliged to emit any code for calls to it, 3531 * even when marked __noinline. However, gdb depends on those 3532 * calls being made. 3533 */ 3534 __asm __volatile("" : : : "memory"); 3535 } 3536 3537 /* 3538 * Get address of the pointer variable in the main program. 3539 * Prefer non-weak symbol over the weak one. 3540 */ 3541 static const void ** 3542 get_program_var_addr(const char *name, RtldLockState *lockstate) 3543 { 3544 SymLook req; 3545 DoneList donelist; 3546 3547 symlook_init(&req, name); 3548 req.lockstate = lockstate; 3549 donelist_init(&donelist); 3550 if (symlook_global(&req, &donelist) != 0) 3551 return (NULL); 3552 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3553 return ((const void **)make_function_pointer(req.sym_out, 3554 req.defobj_out)); 3555 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3556 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3557 else 3558 return ((const void **)(req.defobj_out->relocbase + 3559 req.sym_out->st_value)); 3560 } 3561 3562 /* 3563 * Set a pointer variable in the main program to the given value. This 3564 * is used to set key variables such as "environ" before any of the 3565 * init functions are called. 3566 */ 3567 static void 3568 set_program_var(const char *name, const void *value) 3569 { 3570 const void **addr; 3571 3572 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3573 dbg("\"%s\": *%p <-- %p", name, addr, value); 3574 *addr = value; 3575 } 3576 } 3577 3578 /* 3579 * Search the global objects, including dependencies and main object, 3580 * for the given symbol. 3581 */ 3582 static int 3583 symlook_global(SymLook *req, DoneList *donelist) 3584 { 3585 SymLook req1; 3586 const Objlist_Entry *elm; 3587 int res; 3588 3589 symlook_init_from_req(&req1, req); 3590 3591 /* Search all objects loaded at program start up. */ 3592 if (req->defobj_out == NULL || 3593 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3594 res = symlook_list(&req1, &list_main, donelist); 3595 if (res == 0 && (req->defobj_out == NULL || 3596 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3597 req->sym_out = req1.sym_out; 3598 req->defobj_out = req1.defobj_out; 3599 assert(req->defobj_out != NULL); 3600 } 3601 } 3602 3603 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3604 STAILQ_FOREACH(elm, &list_global, link) { 3605 if (req->defobj_out != NULL && 3606 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3607 break; 3608 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3609 if (res == 0 && (req->defobj_out == NULL || 3610 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3611 req->sym_out = req1.sym_out; 3612 req->defobj_out = req1.defobj_out; 3613 assert(req->defobj_out != NULL); 3614 } 3615 } 3616 3617 return (req->sym_out != NULL ? 0 : ESRCH); 3618 } 3619 3620 /* 3621 * This is a special version of getenv which is far more efficient 3622 * at finding LD_ environment vars. 3623 */ 3624 static 3625 const char * 3626 _getenv_ld(const char *id) 3627 { 3628 const char *envp; 3629 int i, j; 3630 int idlen = strlen(id); 3631 3632 if (ld_index == LD_ARY_CACHE) 3633 return(getenv(id)); 3634 if (ld_index == 0) { 3635 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) { 3636 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_') 3637 ld_ary[j++] = envp; 3638 } 3639 if (j == 0) 3640 ld_ary[j++] = ""; 3641 ld_index = j; 3642 } 3643 for (i = ld_index - 1; i >= 0; --i) { 3644 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=') 3645 return(ld_ary[i] + idlen + 1); 3646 } 3647 return(NULL); 3648 } 3649 3650 /* 3651 * Given a symbol name in a referencing object, find the corresponding 3652 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3653 * no definition was found. Returns a pointer to the Obj_Entry of the 3654 * defining object via the reference parameter DEFOBJ_OUT. 3655 */ 3656 static int 3657 symlook_default(SymLook *req, const Obj_Entry *refobj) 3658 { 3659 DoneList donelist; 3660 const Objlist_Entry *elm; 3661 SymLook req1; 3662 int res; 3663 3664 donelist_init(&donelist); 3665 symlook_init_from_req(&req1, req); 3666 3667 /* Look first in the referencing object if linked symbolically. */ 3668 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3669 res = symlook_obj(&req1, refobj); 3670 if (res == 0) { 3671 req->sym_out = req1.sym_out; 3672 req->defobj_out = req1.defobj_out; 3673 assert(req->defobj_out != NULL); 3674 } 3675 } 3676 3677 symlook_global(req, &donelist); 3678 3679 /* Search all dlopened DAGs containing the referencing object. */ 3680 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3681 if (req->sym_out != NULL && 3682 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3683 break; 3684 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3685 if (res == 0 && (req->sym_out == NULL || 3686 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3687 req->sym_out = req1.sym_out; 3688 req->defobj_out = req1.defobj_out; 3689 assert(req->defobj_out != NULL); 3690 } 3691 } 3692 3693 /* 3694 * Search the dynamic linker itself, and possibly resolve the 3695 * symbol from there. This is how the application links to 3696 * dynamic linker services such as dlopen. 3697 */ 3698 if (req->sym_out == NULL || 3699 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3700 res = symlook_obj(&req1, &obj_rtld); 3701 if (res == 0) { 3702 req->sym_out = req1.sym_out; 3703 req->defobj_out = req1.defobj_out; 3704 assert(req->defobj_out != NULL); 3705 } 3706 } 3707 3708 return (req->sym_out != NULL ? 0 : ESRCH); 3709 } 3710 3711 static int 3712 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3713 { 3714 const Elf_Sym *def; 3715 const Obj_Entry *defobj; 3716 const Objlist_Entry *elm; 3717 SymLook req1; 3718 int res; 3719 3720 def = NULL; 3721 defobj = NULL; 3722 STAILQ_FOREACH(elm, objlist, link) { 3723 if (donelist_check(dlp, elm->obj)) 3724 continue; 3725 symlook_init_from_req(&req1, req); 3726 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3727 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3728 def = req1.sym_out; 3729 defobj = req1.defobj_out; 3730 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3731 break; 3732 } 3733 } 3734 } 3735 if (def != NULL) { 3736 req->sym_out = def; 3737 req->defobj_out = defobj; 3738 return (0); 3739 } 3740 return (ESRCH); 3741 } 3742 3743 /* 3744 * Search the chain of DAGS cointed to by the given Needed_Entry 3745 * for a symbol of the given name. Each DAG is scanned completely 3746 * before advancing to the next one. Returns a pointer to the symbol, 3747 * or NULL if no definition was found. 3748 */ 3749 static int 3750 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3751 { 3752 const Elf_Sym *def; 3753 const Needed_Entry *n; 3754 const Obj_Entry *defobj; 3755 SymLook req1; 3756 int res; 3757 3758 def = NULL; 3759 defobj = NULL; 3760 symlook_init_from_req(&req1, req); 3761 for (n = needed; n != NULL; n = n->next) { 3762 if (n->obj == NULL || 3763 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3764 continue; 3765 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3766 def = req1.sym_out; 3767 defobj = req1.defobj_out; 3768 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3769 break; 3770 } 3771 } 3772 if (def != NULL) { 3773 req->sym_out = def; 3774 req->defobj_out = defobj; 3775 return (0); 3776 } 3777 return (ESRCH); 3778 } 3779 3780 /* 3781 * Search the symbol table of a single shared object for a symbol of 3782 * the given name and version, if requested. Returns a pointer to the 3783 * symbol, or NULL if no definition was found. If the object is 3784 * filter, return filtered symbol from filtee. 3785 * 3786 * The symbol's hash value is passed in for efficiency reasons; that 3787 * eliminates many recomputations of the hash value. 3788 */ 3789 int 3790 symlook_obj(SymLook *req, const Obj_Entry *obj) 3791 { 3792 DoneList donelist; 3793 SymLook req1; 3794 int flags, res, mres; 3795 3796 /* 3797 * If there is at least one valid hash at this point, we prefer to 3798 * use the faster GNU version if available. 3799 */ 3800 if (obj->valid_hash_gnu) 3801 mres = symlook_obj1_gnu(req, obj); 3802 else if (obj->valid_hash_sysv) 3803 mres = symlook_obj1_sysv(req, obj); 3804 else 3805 return (EINVAL); 3806 3807 if (mres == 0) { 3808 if (obj->needed_filtees != NULL) { 3809 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3810 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3811 donelist_init(&donelist); 3812 symlook_init_from_req(&req1, req); 3813 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3814 if (res == 0) { 3815 req->sym_out = req1.sym_out; 3816 req->defobj_out = req1.defobj_out; 3817 } 3818 return (res); 3819 } 3820 if (obj->needed_aux_filtees != NULL) { 3821 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3822 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3823 donelist_init(&donelist); 3824 symlook_init_from_req(&req1, req); 3825 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3826 if (res == 0) { 3827 req->sym_out = req1.sym_out; 3828 req->defobj_out = req1.defobj_out; 3829 return (res); 3830 } 3831 } 3832 } 3833 return (mres); 3834 } 3835 3836 /* Symbol match routine common to both hash functions */ 3837 static bool 3838 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3839 const unsigned long symnum) 3840 { 3841 Elf_Versym verndx; 3842 const Elf_Sym *symp; 3843 const char *strp; 3844 3845 symp = obj->symtab + symnum; 3846 strp = obj->strtab + symp->st_name; 3847 3848 switch (ELF_ST_TYPE(symp->st_info)) { 3849 case STT_FUNC: 3850 case STT_NOTYPE: 3851 case STT_OBJECT: 3852 case STT_COMMON: 3853 case STT_GNU_IFUNC: 3854 if (symp->st_value == 0) 3855 return (false); 3856 /* fallthrough */ 3857 case STT_TLS: 3858 if (symp->st_shndx != SHN_UNDEF) 3859 break; 3860 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3861 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3862 break; 3863 /* fallthrough */ 3864 default: 3865 return (false); 3866 } 3867 if (strcmp(req->name, strp) != 0) 3868 return (false); 3869 3870 if (req->ventry == NULL) { 3871 if (obj->versyms != NULL) { 3872 verndx = VER_NDX(obj->versyms[symnum]); 3873 if (verndx > obj->vernum) { 3874 _rtld_error( 3875 "%s: symbol %s references wrong version %d", 3876 obj->path, obj->strtab + symnum, verndx); 3877 return (false); 3878 } 3879 /* 3880 * If we are not called from dlsym (i.e. this 3881 * is a normal relocation from unversioned 3882 * binary), accept the symbol immediately if 3883 * it happens to have first version after this 3884 * shared object became versioned. Otherwise, 3885 * if symbol is versioned and not hidden, 3886 * remember it. If it is the only symbol with 3887 * this name exported by the shared object, it 3888 * will be returned as a match by the calling 3889 * function. If symbol is global (verndx < 2) 3890 * accept it unconditionally. 3891 */ 3892 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3893 verndx == VER_NDX_GIVEN) { 3894 result->sym_out = symp; 3895 return (true); 3896 } 3897 else if (verndx >= VER_NDX_GIVEN) { 3898 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3899 == 0) { 3900 if (result->vsymp == NULL) 3901 result->vsymp = symp; 3902 result->vcount++; 3903 } 3904 return (false); 3905 } 3906 } 3907 result->sym_out = symp; 3908 return (true); 3909 } 3910 if (obj->versyms == NULL) { 3911 if (object_match_name(obj, req->ventry->name)) { 3912 _rtld_error("%s: object %s should provide version %s " 3913 "for symbol %s", obj_rtld.path, obj->path, 3914 req->ventry->name, obj->strtab + symnum); 3915 return (false); 3916 } 3917 } else { 3918 verndx = VER_NDX(obj->versyms[symnum]); 3919 if (verndx > obj->vernum) { 3920 _rtld_error("%s: symbol %s references wrong version %d", 3921 obj->path, obj->strtab + symnum, verndx); 3922 return (false); 3923 } 3924 if (obj->vertab[verndx].hash != req->ventry->hash || 3925 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3926 /* 3927 * Version does not match. Look if this is a 3928 * global symbol and if it is not hidden. If 3929 * global symbol (verndx < 2) is available, 3930 * use it. Do not return symbol if we are 3931 * called by dlvsym, because dlvsym looks for 3932 * a specific version and default one is not 3933 * what dlvsym wants. 3934 */ 3935 if ((req->flags & SYMLOOK_DLSYM) || 3936 (verndx >= VER_NDX_GIVEN) || 3937 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3938 return (false); 3939 } 3940 } 3941 result->sym_out = symp; 3942 return (true); 3943 } 3944 3945 /* 3946 * Search for symbol using SysV hash function. 3947 * obj->buckets is known not to be NULL at this point; the test for this was 3948 * performed with the obj->valid_hash_sysv assignment. 3949 */ 3950 static int 3951 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3952 { 3953 unsigned long symnum; 3954 Sym_Match_Result matchres; 3955 3956 matchres.sym_out = NULL; 3957 matchres.vsymp = NULL; 3958 matchres.vcount = 0; 3959 3960 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3961 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3962 if (symnum >= obj->nchains) 3963 return (ESRCH); /* Bad object */ 3964 3965 if (matched_symbol(req, obj, &matchres, symnum)) { 3966 req->sym_out = matchres.sym_out; 3967 req->defobj_out = obj; 3968 return (0); 3969 } 3970 } 3971 if (matchres.vcount == 1) { 3972 req->sym_out = matchres.vsymp; 3973 req->defobj_out = obj; 3974 return (0); 3975 } 3976 return (ESRCH); 3977 } 3978 3979 /* Search for symbol using GNU hash function */ 3980 static int 3981 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3982 { 3983 Elf_Addr bloom_word; 3984 const Elf32_Word *hashval; 3985 Elf32_Word bucket; 3986 Sym_Match_Result matchres; 3987 unsigned int h1, h2; 3988 unsigned long symnum; 3989 3990 matchres.sym_out = NULL; 3991 matchres.vsymp = NULL; 3992 matchres.vcount = 0; 3993 3994 /* Pick right bitmask word from Bloom filter array */ 3995 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3996 obj->maskwords_bm_gnu]; 3997 3998 /* Calculate modulus word size of gnu hash and its derivative */ 3999 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4000 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4001 4002 /* Filter out the "definitely not in set" queries */ 4003 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4004 return (ESRCH); 4005 4006 /* Locate hash chain and corresponding value element*/ 4007 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4008 if (bucket == 0) 4009 return (ESRCH); 4010 hashval = &obj->chain_zero_gnu[bucket]; 4011 do { 4012 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4013 symnum = hashval - obj->chain_zero_gnu; 4014 if (matched_symbol(req, obj, &matchres, symnum)) { 4015 req->sym_out = matchres.sym_out; 4016 req->defobj_out = obj; 4017 return (0); 4018 } 4019 } 4020 } while ((*hashval++ & 1) == 0); 4021 if (matchres.vcount == 1) { 4022 req->sym_out = matchres.vsymp; 4023 req->defobj_out = obj; 4024 return (0); 4025 } 4026 return (ESRCH); 4027 } 4028 4029 static void 4030 trace_loaded_objects(Obj_Entry *obj) 4031 { 4032 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4033 int c; 4034 4035 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 4036 main_local = ""; 4037 4038 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL) 4039 fmt1 = "\t%o => %p (%x)\n"; 4040 4041 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL) 4042 fmt2 = "\t%o (%x)\n"; 4043 4044 list_containers = _getenv_ld("LD_TRACE_LOADED_OBJECTS_ALL"); 4045 4046 for (; obj; obj = obj->next) { 4047 Needed_Entry *needed; 4048 char *name, *path; 4049 bool is_lib; 4050 4051 if (list_containers && obj->needed != NULL) 4052 rtld_printf("%s:\n", obj->path); 4053 for (needed = obj->needed; needed; needed = needed->next) { 4054 if (needed->obj != NULL) { 4055 if (needed->obj->traced && !list_containers) 4056 continue; 4057 needed->obj->traced = true; 4058 path = needed->obj->path; 4059 } else 4060 path = "not found"; 4061 4062 name = (char *)obj->strtab + needed->name; 4063 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4064 4065 fmt = is_lib ? fmt1 : fmt2; 4066 while ((c = *fmt++) != '\0') { 4067 switch (c) { 4068 default: 4069 rtld_putchar(c); 4070 continue; 4071 case '\\': 4072 switch (c = *fmt) { 4073 case '\0': 4074 continue; 4075 case 'n': 4076 rtld_putchar('\n'); 4077 break; 4078 case 't': 4079 rtld_putchar('\t'); 4080 break; 4081 } 4082 break; 4083 case '%': 4084 switch (c = *fmt) { 4085 case '\0': 4086 continue; 4087 case '%': 4088 default: 4089 rtld_putchar(c); 4090 break; 4091 case 'A': 4092 rtld_putstr(main_local); 4093 break; 4094 case 'a': 4095 rtld_putstr(obj_main->path); 4096 break; 4097 case 'o': 4098 rtld_putstr(name); 4099 break; 4100 case 'p': 4101 rtld_putstr(path); 4102 break; 4103 case 'x': 4104 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4105 0); 4106 break; 4107 } 4108 break; 4109 } 4110 ++fmt; 4111 } 4112 } 4113 } 4114 } 4115 4116 /* 4117 * Unload a dlopened object and its dependencies from memory and from 4118 * our data structures. It is assumed that the DAG rooted in the 4119 * object has already been unreferenced, and that the object has a 4120 * reference count of 0. 4121 */ 4122 static void 4123 unload_object(Obj_Entry *root) 4124 { 4125 Obj_Entry *obj; 4126 Obj_Entry **linkp; 4127 4128 assert(root->refcount == 0); 4129 4130 /* 4131 * Pass over the DAG removing unreferenced objects from 4132 * appropriate lists. 4133 */ 4134 unlink_object(root); 4135 4136 /* Unmap all objects that are no longer referenced. */ 4137 linkp = &obj_list->next; 4138 while ((obj = *linkp) != NULL) { 4139 if (obj->refcount == 0) { 4140 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4141 obj->path); 4142 dbg("unloading \"%s\"", obj->path); 4143 unload_filtees(root); 4144 munmap(obj->mapbase, obj->mapsize); 4145 linkmap_delete(obj); 4146 *linkp = obj->next; 4147 obj_count--; 4148 obj_free(obj); 4149 } else 4150 linkp = &obj->next; 4151 } 4152 obj_tail = linkp; 4153 } 4154 4155 static void 4156 unlink_object(Obj_Entry *root) 4157 { 4158 Objlist_Entry *elm; 4159 4160 if (root->refcount == 0) { 4161 /* Remove the object from the RTLD_GLOBAL list. */ 4162 objlist_remove(&list_global, root); 4163 4164 /* Remove the object from all objects' DAG lists. */ 4165 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4166 objlist_remove(&elm->obj->dldags, root); 4167 if (elm->obj != root) 4168 unlink_object(elm->obj); 4169 } 4170 } 4171 } 4172 4173 static void 4174 ref_dag(Obj_Entry *root) 4175 { 4176 Objlist_Entry *elm; 4177 4178 assert(root->dag_inited); 4179 STAILQ_FOREACH(elm, &root->dagmembers, link) 4180 elm->obj->refcount++; 4181 } 4182 4183 static void 4184 unref_dag(Obj_Entry *root) 4185 { 4186 Objlist_Entry *elm; 4187 4188 assert(root->dag_inited); 4189 STAILQ_FOREACH(elm, &root->dagmembers, link) 4190 elm->obj->refcount--; 4191 } 4192 4193 /* 4194 * Common code for MD __tls_get_addr(). 4195 */ 4196 void * 4197 tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset) 4198 { 4199 Elf_Addr* dtv = *dtvp; 4200 RtldLockState lockstate; 4201 4202 /* Check dtv generation in case new modules have arrived */ 4203 if (dtv[0] != tls_dtv_generation) { 4204 Elf_Addr* newdtv; 4205 int to_copy; 4206 4207 wlock_acquire(rtld_bind_lock, &lockstate); 4208 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4209 to_copy = dtv[1]; 4210 if (to_copy > tls_max_index) 4211 to_copy = tls_max_index; 4212 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4213 newdtv[0] = tls_dtv_generation; 4214 newdtv[1] = tls_max_index; 4215 free(dtv); 4216 lock_release(rtld_bind_lock, &lockstate); 4217 dtv = *dtvp = newdtv; 4218 } 4219 4220 /* Dynamically allocate module TLS if necessary */ 4221 if (!dtv[index + 1]) { 4222 /* Signal safe, wlock will block out signals. */ 4223 wlock_acquire(rtld_bind_lock, &lockstate); 4224 if (!dtv[index + 1]) 4225 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4226 lock_release(rtld_bind_lock, &lockstate); 4227 } 4228 return (void*) (dtv[index + 1] + offset); 4229 } 4230 4231 #if defined(RTLD_STATIC_TLS_VARIANT_II) 4232 4233 /* 4234 * Allocate the static TLS area. Return a pointer to the TCB. The 4235 * static area is based on negative offsets relative to the tcb. 4236 * 4237 * The TCB contains an errno pointer for the system call layer, but because 4238 * we are the RTLD we really have no idea how the caller was compiled so 4239 * the information has to be passed in. errno can either be: 4240 * 4241 * type 0 errno is a simple non-TLS global pointer. 4242 * (special case for e.g. libc_rtld) 4243 * type 1 errno accessed by GOT entry (dynamically linked programs) 4244 * type 2 errno accessed by %gs:OFFSET (statically linked programs) 4245 */ 4246 struct tls_tcb * 4247 allocate_tls(Obj_Entry *objs) 4248 { 4249 Obj_Entry *obj; 4250 size_t data_size; 4251 size_t dtv_size; 4252 struct tls_tcb *tcb; 4253 Elf_Addr *dtv; 4254 Elf_Addr addr; 4255 4256 /* 4257 * Allocate the new TCB. static TLS storage is placed just before the 4258 * TCB to support the %gs:OFFSET (negative offset) model. 4259 */ 4260 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) & 4261 ~RTLD_STATIC_TLS_ALIGN_MASK; 4262 tcb = malloc(data_size + sizeof(*tcb)); 4263 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */ 4264 4265 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr); 4266 dtv = malloc(dtv_size); 4267 bzero(dtv, dtv_size); 4268 4269 #ifdef RTLD_TCB_HAS_SELF_POINTER 4270 tcb->tcb_self = tcb; 4271 #endif 4272 tcb->tcb_dtv = dtv; 4273 tcb->tcb_pthread = NULL; 4274 4275 dtv[0] = tls_dtv_generation; 4276 dtv[1] = tls_max_index; 4277 4278 for (obj = objs; obj; obj = obj->next) { 4279 if (obj->tlsoffset) { 4280 addr = (Elf_Addr)tcb - obj->tlsoffset; 4281 memset((void *)(addr + obj->tlsinitsize), 4282 0, obj->tlssize - obj->tlsinitsize); 4283 if (obj->tlsinit) 4284 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4285 dtv[obj->tlsindex + 1] = addr; 4286 } 4287 } 4288 return(tcb); 4289 } 4290 4291 void 4292 free_tls(struct tls_tcb *tcb) 4293 { 4294 Elf_Addr *dtv; 4295 int dtv_size, i; 4296 Elf_Addr tls_start, tls_end; 4297 size_t data_size; 4298 4299 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) & 4300 ~RTLD_STATIC_TLS_ALIGN_MASK; 4301 4302 dtv = tcb->tcb_dtv; 4303 dtv_size = dtv[1]; 4304 tls_end = (Elf_Addr)tcb; 4305 tls_start = (Elf_Addr)tcb - data_size; 4306 for (i = 0; i < dtv_size; i++) { 4307 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) { 4308 free((void *)dtv[i+2]); 4309 } 4310 } 4311 4312 free((void*) tls_start); 4313 } 4314 4315 #else 4316 #error "Unsupported TLS layout" 4317 #endif 4318 4319 /* 4320 * Allocate TLS block for module with given index. 4321 */ 4322 void * 4323 allocate_module_tls(int index) 4324 { 4325 Obj_Entry* obj; 4326 char* p; 4327 4328 for (obj = obj_list; obj; obj = obj->next) { 4329 if (obj->tlsindex == index) 4330 break; 4331 } 4332 if (!obj) { 4333 _rtld_error("Can't find module with TLS index %d", index); 4334 die(); 4335 } 4336 4337 p = malloc(obj->tlssize); 4338 if (p == NULL) { 4339 _rtld_error("Cannot allocate TLS block for index %d", index); 4340 die(); 4341 } 4342 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4343 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4344 4345 return p; 4346 } 4347 4348 bool 4349 allocate_tls_offset(Obj_Entry *obj) 4350 { 4351 size_t off; 4352 4353 if (obj->tls_done) 4354 return true; 4355 4356 if (obj->tlssize == 0) { 4357 obj->tls_done = true; 4358 return true; 4359 } 4360 4361 if (obj->tlsindex == 1) 4362 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4363 else 4364 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4365 obj->tlssize, obj->tlsalign); 4366 4367 /* 4368 * If we have already fixed the size of the static TLS block, we 4369 * must stay within that size. When allocating the static TLS, we 4370 * leave a small amount of space spare to be used for dynamically 4371 * loading modules which use static TLS. 4372 */ 4373 if (tls_static_space) { 4374 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4375 return false; 4376 } 4377 4378 tls_last_offset = obj->tlsoffset = off; 4379 tls_last_size = obj->tlssize; 4380 obj->tls_done = true; 4381 4382 return true; 4383 } 4384 4385 void 4386 free_tls_offset(Obj_Entry *obj) 4387 { 4388 #ifdef RTLD_STATIC_TLS_VARIANT_II 4389 /* 4390 * If we were the last thing to allocate out of the static TLS 4391 * block, we give our space back to the 'allocator'. This is a 4392 * simplistic workaround to allow libGL.so.1 to be loaded and 4393 * unloaded multiple times. We only handle the Variant II 4394 * mechanism for now - this really needs a proper allocator. 4395 */ 4396 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4397 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4398 tls_last_offset -= obj->tlssize; 4399 tls_last_size = 0; 4400 } 4401 #endif 4402 } 4403 4404 struct tls_tcb * 4405 _rtld_allocate_tls(void) 4406 { 4407 struct tls_tcb *new_tcb; 4408 RtldLockState lockstate; 4409 4410 wlock_acquire(rtld_bind_lock, &lockstate); 4411 new_tcb = allocate_tls(obj_list); 4412 lock_release(rtld_bind_lock, &lockstate); 4413 return (new_tcb); 4414 } 4415 4416 void 4417 _rtld_free_tls(struct tls_tcb *tcb) 4418 { 4419 RtldLockState lockstate; 4420 4421 wlock_acquire(rtld_bind_lock, &lockstate); 4422 free_tls(tcb); 4423 lock_release(rtld_bind_lock, &lockstate); 4424 } 4425 4426 static void 4427 object_add_name(Obj_Entry *obj, const char *name) 4428 { 4429 Name_Entry *entry; 4430 size_t len; 4431 4432 len = strlen(name); 4433 entry = malloc(sizeof(Name_Entry) + len); 4434 4435 if (entry != NULL) { 4436 strcpy(entry->name, name); 4437 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4438 } 4439 } 4440 4441 static int 4442 object_match_name(const Obj_Entry *obj, const char *name) 4443 { 4444 Name_Entry *entry; 4445 4446 STAILQ_FOREACH(entry, &obj->names, link) { 4447 if (strcmp(name, entry->name) == 0) 4448 return (1); 4449 } 4450 return (0); 4451 } 4452 4453 static Obj_Entry * 4454 locate_dependency(const Obj_Entry *obj, const char *name) 4455 { 4456 const Objlist_Entry *entry; 4457 const Needed_Entry *needed; 4458 4459 STAILQ_FOREACH(entry, &list_main, link) { 4460 if (object_match_name(entry->obj, name)) 4461 return entry->obj; 4462 } 4463 4464 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4465 if (strcmp(obj->strtab + needed->name, name) == 0 || 4466 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4467 /* 4468 * If there is DT_NEEDED for the name we are looking for, 4469 * we are all set. Note that object might not be found if 4470 * dependency was not loaded yet, so the function can 4471 * return NULL here. This is expected and handled 4472 * properly by the caller. 4473 */ 4474 return (needed->obj); 4475 } 4476 } 4477 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4478 obj->path, name); 4479 die(); 4480 } 4481 4482 static int 4483 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4484 const Elf_Vernaux *vna) 4485 { 4486 const Elf_Verdef *vd; 4487 const char *vername; 4488 4489 vername = refobj->strtab + vna->vna_name; 4490 vd = depobj->verdef; 4491 if (vd == NULL) { 4492 _rtld_error("%s: version %s required by %s not defined", 4493 depobj->path, vername, refobj->path); 4494 return (-1); 4495 } 4496 for (;;) { 4497 if (vd->vd_version != VER_DEF_CURRENT) { 4498 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4499 depobj->path, vd->vd_version); 4500 return (-1); 4501 } 4502 if (vna->vna_hash == vd->vd_hash) { 4503 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4504 ((char *)vd + vd->vd_aux); 4505 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4506 return (0); 4507 } 4508 if (vd->vd_next == 0) 4509 break; 4510 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4511 } 4512 if (vna->vna_flags & VER_FLG_WEAK) 4513 return (0); 4514 _rtld_error("%s: version %s required by %s not found", 4515 depobj->path, vername, refobj->path); 4516 return (-1); 4517 } 4518 4519 static int 4520 rtld_verify_object_versions(Obj_Entry *obj) 4521 { 4522 const Elf_Verneed *vn; 4523 const Elf_Verdef *vd; 4524 const Elf_Verdaux *vda; 4525 const Elf_Vernaux *vna; 4526 const Obj_Entry *depobj; 4527 int maxvernum, vernum; 4528 4529 if (obj->ver_checked) 4530 return (0); 4531 obj->ver_checked = true; 4532 4533 maxvernum = 0; 4534 /* 4535 * Walk over defined and required version records and figure out 4536 * max index used by any of them. Do very basic sanity checking 4537 * while there. 4538 */ 4539 vn = obj->verneed; 4540 while (vn != NULL) { 4541 if (vn->vn_version != VER_NEED_CURRENT) { 4542 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4543 obj->path, vn->vn_version); 4544 return (-1); 4545 } 4546 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4547 for (;;) { 4548 vernum = VER_NEED_IDX(vna->vna_other); 4549 if (vernum > maxvernum) 4550 maxvernum = vernum; 4551 if (vna->vna_next == 0) 4552 break; 4553 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4554 } 4555 if (vn->vn_next == 0) 4556 break; 4557 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4558 } 4559 4560 vd = obj->verdef; 4561 while (vd != NULL) { 4562 if (vd->vd_version != VER_DEF_CURRENT) { 4563 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4564 obj->path, vd->vd_version); 4565 return (-1); 4566 } 4567 vernum = VER_DEF_IDX(vd->vd_ndx); 4568 if (vernum > maxvernum) 4569 maxvernum = vernum; 4570 if (vd->vd_next == 0) 4571 break; 4572 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4573 } 4574 4575 if (maxvernum == 0) 4576 return (0); 4577 4578 /* 4579 * Store version information in array indexable by version index. 4580 * Verify that object version requirements are satisfied along the 4581 * way. 4582 */ 4583 obj->vernum = maxvernum + 1; 4584 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4585 4586 vd = obj->verdef; 4587 while (vd != NULL) { 4588 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4589 vernum = VER_DEF_IDX(vd->vd_ndx); 4590 assert(vernum <= maxvernum); 4591 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4592 obj->vertab[vernum].hash = vd->vd_hash; 4593 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4594 obj->vertab[vernum].file = NULL; 4595 obj->vertab[vernum].flags = 0; 4596 } 4597 if (vd->vd_next == 0) 4598 break; 4599 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4600 } 4601 4602 vn = obj->verneed; 4603 while (vn != NULL) { 4604 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4605 if (depobj == NULL) 4606 return (-1); 4607 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4608 for (;;) { 4609 if (check_object_provided_version(obj, depobj, vna)) 4610 return (-1); 4611 vernum = VER_NEED_IDX(vna->vna_other); 4612 assert(vernum <= maxvernum); 4613 obj->vertab[vernum].hash = vna->vna_hash; 4614 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4615 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4616 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4617 VER_INFO_HIDDEN : 0; 4618 if (vna->vna_next == 0) 4619 break; 4620 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4621 } 4622 if (vn->vn_next == 0) 4623 break; 4624 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4625 } 4626 return 0; 4627 } 4628 4629 static int 4630 rtld_verify_versions(const Objlist *objlist) 4631 { 4632 Objlist_Entry *entry; 4633 int rc; 4634 4635 rc = 0; 4636 STAILQ_FOREACH(entry, objlist, link) { 4637 /* 4638 * Skip dummy objects or objects that have their version requirements 4639 * already checked. 4640 */ 4641 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4642 continue; 4643 if (rtld_verify_object_versions(entry->obj) == -1) { 4644 rc = -1; 4645 if (ld_tracing == NULL) 4646 break; 4647 } 4648 } 4649 if (rc == 0 || ld_tracing != NULL) 4650 rc = rtld_verify_object_versions(&obj_rtld); 4651 return rc; 4652 } 4653 4654 const Ver_Entry * 4655 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4656 { 4657 Elf_Versym vernum; 4658 4659 if (obj->vertab) { 4660 vernum = VER_NDX(obj->versyms[symnum]); 4661 if (vernum >= obj->vernum) { 4662 _rtld_error("%s: symbol %s has wrong verneed value %d", 4663 obj->path, obj->strtab + symnum, vernum); 4664 } else if (obj->vertab[vernum].hash != 0) { 4665 return &obj->vertab[vernum]; 4666 } 4667 } 4668 return NULL; 4669 } 4670 4671 int 4672 _rtld_get_stack_prot(void) 4673 { 4674 4675 return (stack_prot); 4676 } 4677 4678 static void 4679 map_stacks_exec(RtldLockState *lockstate) 4680 { 4681 return; 4682 /* 4683 * Stack protection must be implemented in the kernel before the dynamic 4684 * linker can handle PT_GNU_STACK sections. 4685 * The following is the FreeBSD implementation of map_stacks_exec() 4686 * void (*thr_map_stacks_exec)(void); 4687 * 4688 * if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4689 * return; 4690 * thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4691 * get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4692 * if (thr_map_stacks_exec != NULL) { 4693 * stack_prot |= PROT_EXEC; 4694 * thr_map_stacks_exec(); 4695 * } 4696 */ 4697 } 4698 4699 void 4700 symlook_init(SymLook *dst, const char *name) 4701 { 4702 4703 bzero(dst, sizeof(*dst)); 4704 dst->name = name; 4705 dst->hash = elf_hash(name); 4706 dst->hash_gnu = gnu_hash(name); 4707 } 4708 4709 static void 4710 symlook_init_from_req(SymLook *dst, const SymLook *src) 4711 { 4712 4713 dst->name = src->name; 4714 dst->hash = src->hash; 4715 dst->hash_gnu = src->hash_gnu; 4716 dst->ventry = src->ventry; 4717 dst->flags = src->flags; 4718 dst->defobj_out = NULL; 4719 dst->sym_out = NULL; 4720 dst->lockstate = src->lockstate; 4721 } 4722 4723 #ifdef ENABLE_OSRELDATE 4724 /* 4725 * Overrides for libc_pic-provided functions. 4726 */ 4727 4728 int 4729 __getosreldate(void) 4730 { 4731 size_t len; 4732 int oid[2]; 4733 int error, osrel; 4734 4735 if (osreldate != 0) 4736 return (osreldate); 4737 4738 oid[0] = CTL_KERN; 4739 oid[1] = KERN_OSRELDATE; 4740 osrel = 0; 4741 len = sizeof(osrel); 4742 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4743 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4744 osreldate = osrel; 4745 return (osreldate); 4746 } 4747 #endif 4748 4749 /* 4750 * No unresolved symbols for rtld. 4751 */ 4752 void 4753 __pthread_cxa_finalize(struct dl_phdr_info *a) 4754 { 4755 } 4756 4757 const char * 4758 rtld_strerror(int errnum) 4759 { 4760 4761 if (errnum < 0 || errnum >= sys_nerr) 4762 return ("Unknown error"); 4763 return (sys_errlist[errnum]); 4764 } 4765