1 /*- 2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 4 * Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>. 5 * Copyright 2012 John Marino <draco@marino.st>. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 /* 32 * Dynamic linker for ELF. 33 * 34 * John Polstra <jdp@polstra.com>. 35 */ 36 37 #ifndef __GNUC__ 38 #error "GCC is needed to compile this file" 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/mount.h> 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 #include <sys/sysctl.h> 46 #include <sys/uio.h> 47 #include <sys/utsname.h> 48 #include <sys/ktrace.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "rtld.h" 62 #include "libmap.h" 63 #include "rtld_tls.h" 64 #include "rtld_printf.h" 65 #include "notes.h" 66 67 #ifndef COMPAT_32BIT 68 #define PATH_RTLD "/libexec/ld-elf.so.1" 69 #else 70 #define PATH_RTLD "/libexec/ld-elf32.so.1" 71 #endif 72 73 /* Types. */ 74 typedef void (*func_ptr_type)(); 75 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 76 77 /* 78 * Function declarations. 79 */ 80 static const char *basename(const char *); 81 static void die(void) __dead2; 82 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 83 const Elf_Dyn **, const Elf_Dyn **); 84 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 85 const Elf_Dyn *); 86 static void digest_dynamic(Obj_Entry *, int); 87 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 88 static Obj_Entry *dlcheck(void *); 89 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 90 int lo_flags, int mode, RtldLockState *lockstate); 91 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 92 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 93 static bool donelist_check(DoneList *, const Obj_Entry *); 94 static void errmsg_restore(char *); 95 static char *errmsg_save(void); 96 static void *fill_search_info(const char *, size_t, void *); 97 static char *find_library(const char *, const Obj_Entry *, int *); 98 static const char *gethints(bool); 99 static void init_dag(Obj_Entry *); 100 static void init_pagesizes(Elf_Auxinfo **aux_info); 101 static void init_rtld(caddr_t, Elf_Auxinfo **); 102 static void initlist_add_neededs(Needed_Entry *, Objlist *); 103 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 104 static void linkmap_add(Obj_Entry *); 105 static void linkmap_delete(Obj_Entry *); 106 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 107 static void unload_filtees(Obj_Entry *); 108 static int load_needed_objects(Obj_Entry *, int); 109 static int load_preload_objects(void); 110 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 111 static void map_stacks_exec(RtldLockState *); 112 static Obj_Entry *obj_from_addr(const void *); 113 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 114 static void objlist_call_init(Objlist *, RtldLockState *); 115 static void objlist_clear(Objlist *); 116 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 117 static void objlist_init(Objlist *); 118 static void objlist_push_head(Objlist *, Obj_Entry *); 119 static void objlist_push_tail(Objlist *, Obj_Entry *); 120 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 121 static void objlist_remove(Objlist *, Obj_Entry *); 122 static int parse_libdir(const char *); 123 static void *path_enumerate(const char *, path_enum_proc, void *); 124 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 125 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 126 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 127 int flags, RtldLockState *lockstate); 128 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 129 RtldLockState *); 130 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 131 int flags, RtldLockState *lockstate); 132 static int rtld_dirname(const char *, char *); 133 static int rtld_dirname_abs(const char *, char *); 134 static void *rtld_dlopen(const char *name, int fd, int mode); 135 static void rtld_exit(void); 136 static char *search_library_path(const char *, const char *); 137 static char *search_library_pathfds(const char *, const char *, int *); 138 static const void **get_program_var_addr(const char *, RtldLockState *); 139 static void set_program_var(const char *, const void *); 140 static int symlook_default(SymLook *, const Obj_Entry *refobj); 141 static int symlook_global(SymLook *, DoneList *); 142 static void symlook_init_from_req(SymLook *, const SymLook *); 143 static int symlook_list(SymLook *, const Objlist *, DoneList *); 144 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 145 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 146 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 147 static void trace_loaded_objects(Obj_Entry *); 148 static void unlink_object(Obj_Entry *); 149 static void unload_object(Obj_Entry *); 150 static void unref_dag(Obj_Entry *); 151 static void ref_dag(Obj_Entry *); 152 static char *origin_subst_one(char *, const char *, const char *, bool); 153 static char *origin_subst(char *, const char *); 154 static void preinit_main(void); 155 static int rtld_verify_versions(const Objlist *); 156 static int rtld_verify_object_versions(Obj_Entry *); 157 static void object_add_name(Obj_Entry *, const char *); 158 static int object_match_name(const Obj_Entry *, const char *); 159 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 160 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 161 struct dl_phdr_info *phdr_info); 162 static uint32_t gnu_hash(const char *); 163 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 164 const unsigned long); 165 166 void r_debug_state(struct r_debug *, struct link_map *) __noinline; 167 void _r_debug_postinit(struct link_map *) __noinline; 168 169 int __sys_openat(int, const char *, int, ...); 170 171 /* 172 * Data declarations. 173 */ 174 static char *error_message; /* Message for dlerror(), or NULL */ 175 struct r_debug r_debug; /* for GDB; */ 176 static bool libmap_disable; /* Disable libmap */ 177 static bool ld_loadfltr; /* Immediate filters processing */ 178 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 179 static bool trust; /* False for setuid and setgid programs */ 180 static bool dangerous_ld_env; /* True if environment variables have been 181 used to affect the libraries loaded */ 182 static char *ld_bind_now; /* Environment variable for immediate binding */ 183 static char *ld_debug; /* Environment variable for debugging */ 184 static char *ld_library_path; /* Environment variable for search path */ 185 static char *ld_library_dirs; /* Environment variable for library descriptors */ 186 static char *ld_preload; /* Environment variable for libraries to 187 load first */ 188 static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 189 static char *ld_tracing; /* Called from ldd to print libs */ 190 static char *ld_utrace; /* Use utrace() to log events. */ 191 static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 192 static Obj_Entry **obj_tail; /* Link field of last object in list */ 193 static Obj_Entry *obj_main; /* The main program shared object */ 194 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 195 static unsigned int obj_count; /* Number of objects in obj_list */ 196 static unsigned int obj_loads; /* Number of objects in obj_list */ 197 198 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 199 STAILQ_HEAD_INITIALIZER(list_global); 200 static Objlist list_main = /* Objects loaded at program startup */ 201 STAILQ_HEAD_INITIALIZER(list_main); 202 static Objlist list_fini = /* Objects needing fini() calls */ 203 STAILQ_HEAD_INITIALIZER(list_fini); 204 205 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 206 207 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 208 209 extern Elf_Dyn _DYNAMIC; 210 #pragma weak _DYNAMIC 211 #ifndef RTLD_IS_DYNAMIC 212 #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 213 #endif 214 215 int npagesizes, osreldate; 216 size_t *pagesizes; 217 218 long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 219 220 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 221 static int max_stack_flags; 222 223 /* 224 * Global declarations normally provided by crt1. The dynamic linker is 225 * not built with crt1, so we have to provide them ourselves. 226 */ 227 char *__progname; 228 char **environ; 229 230 /* 231 * Used to pass argc, argv to init functions. 232 */ 233 int main_argc; 234 char **main_argv; 235 236 /* 237 * Globals to control TLS allocation. 238 */ 239 size_t tls_last_offset; /* Static TLS offset of last module */ 240 size_t tls_last_size; /* Static TLS size of last module */ 241 size_t tls_static_space; /* Static TLS space allocated */ 242 size_t tls_static_max_align; 243 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 244 int tls_max_index = 1; /* Largest module index allocated */ 245 246 bool ld_library_path_rpath = false; 247 248 /* 249 * Fill in a DoneList with an allocation large enough to hold all of 250 * the currently-loaded objects. Keep this as a macro since it calls 251 * alloca and we want that to occur within the scope of the caller. 252 */ 253 #define donelist_init(dlp) \ 254 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 255 assert((dlp)->objs != NULL), \ 256 (dlp)->num_alloc = obj_count, \ 257 (dlp)->num_used = 0) 258 259 #define UTRACE_DLOPEN_START 1 260 #define UTRACE_DLOPEN_STOP 2 261 #define UTRACE_DLCLOSE_START 3 262 #define UTRACE_DLCLOSE_STOP 4 263 #define UTRACE_LOAD_OBJECT 5 264 #define UTRACE_UNLOAD_OBJECT 6 265 #define UTRACE_ADD_RUNDEP 7 266 #define UTRACE_PRELOAD_FINISHED 8 267 #define UTRACE_INIT_CALL 9 268 #define UTRACE_FINI_CALL 10 269 270 struct utrace_rtld { 271 char sig[4]; /* 'RTLD' */ 272 int event; 273 void *handle; 274 void *mapbase; /* Used for 'parent' and 'init/fini' */ 275 size_t mapsize; 276 int refcnt; /* Used for 'mode' */ 277 char name[MAXPATHLEN]; 278 }; 279 280 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 281 if (ld_utrace != NULL) \ 282 ld_utrace_log(e, h, mb, ms, r, n); \ 283 } while (0) 284 285 static void 286 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 287 int refcnt, const char *name) 288 { 289 struct utrace_rtld ut; 290 291 ut.sig[0] = 'R'; 292 ut.sig[1] = 'T'; 293 ut.sig[2] = 'L'; 294 ut.sig[3] = 'D'; 295 ut.event = event; 296 ut.handle = handle; 297 ut.mapbase = mapbase; 298 ut.mapsize = mapsize; 299 ut.refcnt = refcnt; 300 bzero(ut.name, sizeof(ut.name)); 301 if (name) 302 strlcpy(ut.name, name, sizeof(ut.name)); 303 utrace(&ut, sizeof(ut)); 304 } 305 306 /* 307 * Main entry point for dynamic linking. The first argument is the 308 * stack pointer. The stack is expected to be laid out as described 309 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 310 * Specifically, the stack pointer points to a word containing 311 * ARGC. Following that in the stack is a null-terminated sequence 312 * of pointers to argument strings. Then comes a null-terminated 313 * sequence of pointers to environment strings. Finally, there is a 314 * sequence of "auxiliary vector" entries. 315 * 316 * The second argument points to a place to store the dynamic linker's 317 * exit procedure pointer and the third to a place to store the main 318 * program's object. 319 * 320 * The return value is the main program's entry point. 321 */ 322 func_ptr_type 323 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 324 { 325 Elf_Auxinfo *aux_info[AT_COUNT]; 326 int i; 327 int argc; 328 char **argv; 329 char **env; 330 Elf_Auxinfo *aux; 331 Elf_Auxinfo *auxp; 332 const char *argv0; 333 Objlist_Entry *entry; 334 Obj_Entry *obj; 335 Obj_Entry **preload_tail; 336 Obj_Entry *last_interposer; 337 Objlist initlist; 338 RtldLockState lockstate; 339 char *library_path_rpath; 340 int mib[2]; 341 size_t len; 342 343 /* 344 * On entry, the dynamic linker itself has not been relocated yet. 345 * Be very careful not to reference any global data until after 346 * init_rtld has returned. It is OK to reference file-scope statics 347 * and string constants, and to call static and global functions. 348 */ 349 350 /* Find the auxiliary vector on the stack. */ 351 argc = *sp++; 352 argv = (char **) sp; 353 sp += argc + 1; /* Skip over arguments and NULL terminator */ 354 env = (char **) sp; 355 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 356 ; 357 aux = (Elf_Auxinfo *) sp; 358 359 /* Digest the auxiliary vector. */ 360 for (i = 0; i < AT_COUNT; i++) 361 aux_info[i] = NULL; 362 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 363 if (auxp->a_type < AT_COUNT) 364 aux_info[auxp->a_type] = auxp; 365 } 366 367 /* Initialize and relocate ourselves. */ 368 assert(aux_info[AT_BASE] != NULL); 369 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 370 371 __progname = obj_rtld.path; 372 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 373 environ = env; 374 main_argc = argc; 375 main_argv = argv; 376 377 if (aux_info[AT_CANARY] != NULL && 378 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 379 i = aux_info[AT_CANARYLEN]->a_un.a_val; 380 if (i > sizeof(__stack_chk_guard)) 381 i = sizeof(__stack_chk_guard); 382 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 383 } else { 384 mib[0] = CTL_KERN; 385 mib[1] = KERN_ARND; 386 387 len = sizeof(__stack_chk_guard); 388 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 389 len != sizeof(__stack_chk_guard)) { 390 /* If sysctl was unsuccessful, use the "terminator canary". */ 391 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 392 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 393 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 394 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 395 } 396 } 397 398 trust = !issetugid(); 399 400 ld_bind_now = getenv(LD_ "BIND_NOW"); 401 /* 402 * If the process is tainted, then we un-set the dangerous environment 403 * variables. The process will be marked as tainted until setuid(2) 404 * is called. If any child process calls setuid(2) we do not want any 405 * future processes to honor the potentially un-safe variables. 406 */ 407 if (!trust) { 408 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 409 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBRARY_PATH_FDS") || 410 unsetenv(LD_ "LIBMAP_DISABLE") || 411 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 412 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 413 _rtld_error("environment corrupt; aborting"); 414 die(); 415 } 416 } 417 ld_debug = getenv(LD_ "DEBUG"); 418 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 419 libmap_override = getenv(LD_ "LIBMAP"); 420 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 421 ld_library_dirs = getenv(LD_ "LIBRARY_PATH_FDS"); 422 ld_preload = getenv(LD_ "PRELOAD"); 423 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 424 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 425 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 426 if (library_path_rpath != NULL) { 427 if (library_path_rpath[0] == 'y' || 428 library_path_rpath[0] == 'Y' || 429 library_path_rpath[0] == '1') 430 ld_library_path_rpath = true; 431 else 432 ld_library_path_rpath = false; 433 } 434 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 435 (ld_library_path != NULL) || (ld_preload != NULL) || 436 (ld_elf_hints_path != NULL) || ld_loadfltr; 437 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 438 ld_utrace = getenv(LD_ "UTRACE"); 439 440 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 441 ld_elf_hints_path = _PATH_ELF_HINTS; 442 443 if (ld_debug != NULL && *ld_debug != '\0') 444 debug = 1; 445 dbg("%s is initialized, base address = %p", __progname, 446 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 447 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 448 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 449 450 dbg("initializing thread locks"); 451 lockdflt_init(); 452 453 /* 454 * Load the main program, or process its program header if it is 455 * already loaded. 456 */ 457 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 458 int fd = aux_info[AT_EXECFD]->a_un.a_val; 459 dbg("loading main program"); 460 obj_main = map_object(fd, argv0, NULL); 461 close(fd); 462 if (obj_main == NULL) 463 die(); 464 max_stack_flags = obj->stack_flags; 465 } else { /* Main program already loaded. */ 466 const Elf_Phdr *phdr; 467 int phnum; 468 caddr_t entry; 469 470 dbg("processing main program's program header"); 471 assert(aux_info[AT_PHDR] != NULL); 472 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 473 assert(aux_info[AT_PHNUM] != NULL); 474 phnum = aux_info[AT_PHNUM]->a_un.a_val; 475 assert(aux_info[AT_PHENT] != NULL); 476 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 477 assert(aux_info[AT_ENTRY] != NULL); 478 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 479 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 480 die(); 481 } 482 483 if (aux_info[AT_EXECPATH] != 0) { 484 char *kexecpath; 485 char buf[MAXPATHLEN]; 486 487 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 488 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 489 if (kexecpath[0] == '/') 490 obj_main->path = kexecpath; 491 else if (getcwd(buf, sizeof(buf)) == NULL || 492 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 493 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 494 obj_main->path = xstrdup(argv0); 495 else 496 obj_main->path = xstrdup(buf); 497 } else { 498 dbg("No AT_EXECPATH"); 499 obj_main->path = xstrdup(argv0); 500 } 501 dbg("obj_main path %s", obj_main->path); 502 obj_main->mainprog = true; 503 504 if (aux_info[AT_STACKPROT] != NULL && 505 aux_info[AT_STACKPROT]->a_un.a_val != 0) 506 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 507 508 #ifndef COMPAT_32BIT 509 /* 510 * Get the actual dynamic linker pathname from the executable if 511 * possible. (It should always be possible.) That ensures that 512 * gdb will find the right dynamic linker even if a non-standard 513 * one is being used. 514 */ 515 if (obj_main->interp != NULL && 516 strcmp(obj_main->interp, obj_rtld.path) != 0) { 517 free(obj_rtld.path); 518 obj_rtld.path = xstrdup(obj_main->interp); 519 __progname = obj_rtld.path; 520 } 521 #endif 522 523 digest_dynamic(obj_main, 0); 524 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 525 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 526 obj_main->dynsymcount); 527 528 linkmap_add(obj_main); 529 linkmap_add(&obj_rtld); 530 531 /* Link the main program into the list of objects. */ 532 *obj_tail = obj_main; 533 obj_tail = &obj_main->next; 534 obj_count++; 535 obj_loads++; 536 537 /* Initialize a fake symbol for resolving undefined weak references. */ 538 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 539 sym_zero.st_shndx = SHN_UNDEF; 540 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 541 542 if (!libmap_disable) 543 libmap_disable = (bool)lm_init(libmap_override); 544 545 dbg("loading LD_PRELOAD libraries"); 546 if (load_preload_objects() == -1) 547 die(); 548 preload_tail = obj_tail; 549 550 dbg("loading needed objects"); 551 if (load_needed_objects(obj_main, 0) == -1) 552 die(); 553 554 /* Make a list of all objects loaded at startup. */ 555 last_interposer = obj_main; 556 for (obj = obj_list; obj != NULL; obj = obj->next) { 557 if (obj->z_interpose && obj != obj_main) { 558 objlist_put_after(&list_main, last_interposer, obj); 559 last_interposer = obj; 560 } else { 561 objlist_push_tail(&list_main, obj); 562 } 563 obj->refcount++; 564 } 565 566 dbg("checking for required versions"); 567 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 568 die(); 569 570 if (ld_tracing) { /* We're done */ 571 trace_loaded_objects(obj_main); 572 exit(0); 573 } 574 575 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 576 dump_relocations(obj_main); 577 exit (0); 578 } 579 580 /* 581 * Processing tls relocations requires having the tls offsets 582 * initialized. Prepare offsets before starting initial 583 * relocation processing. 584 */ 585 dbg("initializing initial thread local storage offsets"); 586 STAILQ_FOREACH(entry, &list_main, link) { 587 /* 588 * Allocate all the initial objects out of the static TLS 589 * block even if they didn't ask for it. 590 */ 591 allocate_tls_offset(entry->obj); 592 } 593 594 if (relocate_objects(obj_main, 595 ld_bind_now != NULL && *ld_bind_now != '\0', 596 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 597 die(); 598 599 dbg("doing copy relocations"); 600 if (do_copy_relocations(obj_main) == -1) 601 die(); 602 603 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 604 dump_relocations(obj_main); 605 exit (0); 606 } 607 608 /* 609 * Setup TLS for main thread. This must be done after the 610 * relocations are processed, since tls initialization section 611 * might be the subject for relocations. 612 */ 613 dbg("initializing initial thread local storage"); 614 allocate_initial_tls(obj_list); 615 616 dbg("initializing key program variables"); 617 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 618 set_program_var("environ", env); 619 set_program_var("__elf_aux_vector", aux); 620 621 /* Make a list of init functions to call. */ 622 objlist_init(&initlist); 623 initlist_add_objects(obj_list, preload_tail, &initlist); 624 625 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 626 627 map_stacks_exec(NULL); 628 629 dbg("resolving ifuncs"); 630 if (resolve_objects_ifunc(obj_main, 631 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 632 NULL) == -1) 633 die(); 634 635 if (!obj_main->crt_no_init) { 636 /* 637 * Make sure we don't call the main program's init and fini 638 * functions for binaries linked with old crt1 which calls 639 * _init itself. 640 */ 641 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 642 obj_main->preinit_array = obj_main->init_array = 643 obj_main->fini_array = (Elf_Addr)NULL; 644 } 645 646 wlock_acquire(rtld_bind_lock, &lockstate); 647 if (obj_main->crt_no_init) 648 preinit_main(); 649 objlist_call_init(&initlist, &lockstate); 650 _r_debug_postinit(&obj_main->linkmap); 651 objlist_clear(&initlist); 652 dbg("loading filtees"); 653 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 654 if (ld_loadfltr || obj->z_loadfltr) 655 load_filtees(obj, 0, &lockstate); 656 } 657 lock_release(rtld_bind_lock, &lockstate); 658 659 dbg("transferring control to program entry point = %p", obj_main->entry); 660 661 /* Return the exit procedure and the program entry point. */ 662 *exit_proc = rtld_exit; 663 *objp = obj_main; 664 return (func_ptr_type) obj_main->entry; 665 } 666 667 void * 668 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 669 { 670 void *ptr; 671 Elf_Addr target; 672 673 ptr = (void *)make_function_pointer(def, obj); 674 target = ((Elf_Addr (*)(void))ptr)(); 675 return ((void *)target); 676 } 677 678 Elf_Addr 679 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 680 { 681 const Elf_Rel *rel; 682 const Elf_Sym *def; 683 const Obj_Entry *defobj; 684 Elf_Addr *where; 685 Elf_Addr target; 686 RtldLockState lockstate; 687 688 rlock_acquire(rtld_bind_lock, &lockstate); 689 if (sigsetjmp(lockstate.env, 0) != 0) 690 lock_upgrade(rtld_bind_lock, &lockstate); 691 if (obj->pltrel) 692 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 693 else 694 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 695 696 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 697 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 698 &lockstate); 699 if (def == NULL) 700 die(); 701 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 702 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 703 else 704 target = (Elf_Addr)(defobj->relocbase + def->st_value); 705 706 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 707 defobj->strtab + def->st_name, basename(obj->path), 708 (void *)target, basename(defobj->path)); 709 710 /* 711 * Write the new contents for the jmpslot. Note that depending on 712 * architecture, the value which we need to return back to the 713 * lazy binding trampoline may or may not be the target 714 * address. The value returned from reloc_jmpslot() is the value 715 * that the trampoline needs. 716 */ 717 target = reloc_jmpslot(where, target, defobj, obj, rel); 718 lock_release(rtld_bind_lock, &lockstate); 719 return target; 720 } 721 722 /* 723 * Error reporting function. Use it like printf. If formats the message 724 * into a buffer, and sets things up so that the next call to dlerror() 725 * will return the message. 726 */ 727 void 728 _rtld_error(const char *fmt, ...) 729 { 730 static char buf[512]; 731 va_list ap; 732 733 va_start(ap, fmt); 734 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 735 error_message = buf; 736 va_end(ap); 737 } 738 739 /* 740 * Return a dynamically-allocated copy of the current error message, if any. 741 */ 742 static char * 743 errmsg_save(void) 744 { 745 return error_message == NULL ? NULL : xstrdup(error_message); 746 } 747 748 /* 749 * Restore the current error message from a copy which was previously saved 750 * by errmsg_save(). The copy is freed. 751 */ 752 static void 753 errmsg_restore(char *saved_msg) 754 { 755 if (saved_msg == NULL) 756 error_message = NULL; 757 else { 758 _rtld_error("%s", saved_msg); 759 free(saved_msg); 760 } 761 } 762 763 static const char * 764 basename(const char *name) 765 { 766 const char *p = strrchr(name, '/'); 767 return p != NULL ? p + 1 : name; 768 } 769 770 static struct utsname uts; 771 772 static char * 773 origin_subst_one(char *real, const char *kw, const char *subst, 774 bool may_free) 775 { 776 char *p, *p1, *res, *resp; 777 int subst_len, kw_len, subst_count, old_len, new_len; 778 779 kw_len = strlen(kw); 780 781 /* 782 * First, count the number of the keyword occurences, to 783 * preallocate the final string. 784 */ 785 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 786 p1 = strstr(p, kw); 787 if (p1 == NULL) 788 break; 789 } 790 791 /* 792 * If the keyword is not found, just return. 793 */ 794 if (subst_count == 0) 795 return (may_free ? real : xstrdup(real)); 796 797 /* 798 * There is indeed something to substitute. Calculate the 799 * length of the resulting string, and allocate it. 800 */ 801 subst_len = strlen(subst); 802 old_len = strlen(real); 803 new_len = old_len + (subst_len - kw_len) * subst_count; 804 res = xmalloc(new_len + 1); 805 806 /* 807 * Now, execute the substitution loop. 808 */ 809 for (p = real, resp = res, *resp = '\0';;) { 810 p1 = strstr(p, kw); 811 if (p1 != NULL) { 812 /* Copy the prefix before keyword. */ 813 memcpy(resp, p, p1 - p); 814 resp += p1 - p; 815 /* Keyword replacement. */ 816 memcpy(resp, subst, subst_len); 817 resp += subst_len; 818 *resp = '\0'; 819 p = p1 + kw_len; 820 } else 821 break; 822 } 823 824 /* Copy to the end of string and finish. */ 825 strcat(resp, p); 826 if (may_free) 827 free(real); 828 return (res); 829 } 830 831 static char * 832 origin_subst(char *real, const char *origin_path) 833 { 834 char *res1, *res2, *res3, *res4; 835 836 if (uts.sysname[0] == '\0') { 837 if (uname(&uts) != 0) { 838 _rtld_error("utsname failed: %d", errno); 839 return (NULL); 840 } 841 } 842 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 843 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 844 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 845 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 846 return (res4); 847 } 848 849 static void 850 die(void) 851 { 852 const char *msg = dlerror(); 853 854 if (msg == NULL) 855 msg = "Fatal error"; 856 rtld_fdputstr(STDERR_FILENO, msg); 857 rtld_fdputchar(STDERR_FILENO, '\n'); 858 _exit(1); 859 } 860 861 /* 862 * Process a shared object's DYNAMIC section, and save the important 863 * information in its Obj_Entry structure. 864 */ 865 static void 866 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 867 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 868 { 869 const Elf_Dyn *dynp; 870 Needed_Entry **needed_tail = &obj->needed; 871 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 872 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 873 const Elf_Hashelt *hashtab; 874 const Elf32_Word *hashval; 875 Elf32_Word bkt, nmaskwords; 876 int bloom_size32; 877 bool nmw_power2; 878 int plttype = DT_REL; 879 880 *dyn_rpath = NULL; 881 *dyn_soname = NULL; 882 *dyn_runpath = NULL; 883 884 obj->bind_now = false; 885 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 886 switch (dynp->d_tag) { 887 888 case DT_REL: 889 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 890 break; 891 892 case DT_RELSZ: 893 obj->relsize = dynp->d_un.d_val; 894 break; 895 896 case DT_RELENT: 897 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 898 break; 899 900 case DT_JMPREL: 901 obj->pltrel = (const Elf_Rel *) 902 (obj->relocbase + dynp->d_un.d_ptr); 903 break; 904 905 case DT_PLTRELSZ: 906 obj->pltrelsize = dynp->d_un.d_val; 907 break; 908 909 case DT_RELA: 910 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 911 break; 912 913 case DT_RELASZ: 914 obj->relasize = dynp->d_un.d_val; 915 break; 916 917 case DT_RELAENT: 918 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 919 break; 920 921 case DT_PLTREL: 922 plttype = dynp->d_un.d_val; 923 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 924 break; 925 926 case DT_SYMTAB: 927 obj->symtab = (const Elf_Sym *) 928 (obj->relocbase + dynp->d_un.d_ptr); 929 break; 930 931 case DT_SYMENT: 932 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 933 break; 934 935 case DT_STRTAB: 936 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 937 break; 938 939 case DT_STRSZ: 940 obj->strsize = dynp->d_un.d_val; 941 break; 942 943 case DT_VERNEED: 944 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 945 dynp->d_un.d_val); 946 break; 947 948 case DT_VERNEEDNUM: 949 obj->verneednum = dynp->d_un.d_val; 950 break; 951 952 case DT_VERDEF: 953 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 954 dynp->d_un.d_val); 955 break; 956 957 case DT_VERDEFNUM: 958 obj->verdefnum = dynp->d_un.d_val; 959 break; 960 961 case DT_VERSYM: 962 obj->versyms = (const Elf_Versym *)(obj->relocbase + 963 dynp->d_un.d_val); 964 break; 965 966 case DT_HASH: 967 { 968 hashtab = (const Elf_Hashelt *)(obj->relocbase + 969 dynp->d_un.d_ptr); 970 obj->nbuckets = hashtab[0]; 971 obj->nchains = hashtab[1]; 972 obj->buckets = hashtab + 2; 973 obj->chains = obj->buckets + obj->nbuckets; 974 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 975 obj->buckets != NULL; 976 } 977 break; 978 979 case DT_GNU_HASH: 980 { 981 hashtab = (const Elf_Hashelt *)(obj->relocbase + 982 dynp->d_un.d_ptr); 983 obj->nbuckets_gnu = hashtab[0]; 984 obj->symndx_gnu = hashtab[1]; 985 nmaskwords = hashtab[2]; 986 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 987 /* Number of bitmask words is required to be power of 2 */ 988 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 989 obj->maskwords_bm_gnu = nmaskwords - 1; 990 obj->shift2_gnu = hashtab[3]; 991 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 992 obj->buckets_gnu = hashtab + 4 + bloom_size32; 993 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 994 obj->symndx_gnu; 995 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 996 obj->buckets_gnu != NULL; 997 } 998 break; 999 1000 case DT_NEEDED: 1001 if (!obj->rtld) { 1002 Needed_Entry *nep = NEW(Needed_Entry); 1003 nep->name = dynp->d_un.d_val; 1004 nep->obj = NULL; 1005 nep->next = NULL; 1006 1007 *needed_tail = nep; 1008 needed_tail = &nep->next; 1009 } 1010 break; 1011 1012 case DT_FILTER: 1013 if (!obj->rtld) { 1014 Needed_Entry *nep = NEW(Needed_Entry); 1015 nep->name = dynp->d_un.d_val; 1016 nep->obj = NULL; 1017 nep->next = NULL; 1018 1019 *needed_filtees_tail = nep; 1020 needed_filtees_tail = &nep->next; 1021 } 1022 break; 1023 1024 case DT_AUXILIARY: 1025 if (!obj->rtld) { 1026 Needed_Entry *nep = NEW(Needed_Entry); 1027 nep->name = dynp->d_un.d_val; 1028 nep->obj = NULL; 1029 nep->next = NULL; 1030 1031 *needed_aux_filtees_tail = nep; 1032 needed_aux_filtees_tail = &nep->next; 1033 } 1034 break; 1035 1036 case DT_PLTGOT: 1037 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1038 break; 1039 1040 case DT_TEXTREL: 1041 obj->textrel = true; 1042 break; 1043 1044 case DT_SYMBOLIC: 1045 obj->symbolic = true; 1046 break; 1047 1048 case DT_RPATH: 1049 /* 1050 * We have to wait until later to process this, because we 1051 * might not have gotten the address of the string table yet. 1052 */ 1053 *dyn_rpath = dynp; 1054 break; 1055 1056 case DT_SONAME: 1057 *dyn_soname = dynp; 1058 break; 1059 1060 case DT_RUNPATH: 1061 *dyn_runpath = dynp; 1062 break; 1063 1064 case DT_INIT: 1065 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1066 break; 1067 1068 case DT_PREINIT_ARRAY: 1069 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1070 break; 1071 1072 case DT_PREINIT_ARRAYSZ: 1073 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1074 break; 1075 1076 case DT_INIT_ARRAY: 1077 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1078 break; 1079 1080 case DT_INIT_ARRAYSZ: 1081 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1082 break; 1083 1084 case DT_FINI: 1085 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1086 break; 1087 1088 case DT_FINI_ARRAY: 1089 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1090 break; 1091 1092 case DT_FINI_ARRAYSZ: 1093 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1094 break; 1095 1096 /* 1097 * Don't process DT_DEBUG on MIPS as the dynamic section 1098 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1099 */ 1100 1101 #ifndef __mips__ 1102 case DT_DEBUG: 1103 /* XXX - not implemented yet */ 1104 if (!early) 1105 dbg("Filling in DT_DEBUG entry"); 1106 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1107 break; 1108 #endif 1109 1110 case DT_FLAGS: 1111 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1112 obj->z_origin = true; 1113 if (dynp->d_un.d_val & DF_SYMBOLIC) 1114 obj->symbolic = true; 1115 if (dynp->d_un.d_val & DF_TEXTREL) 1116 obj->textrel = true; 1117 if (dynp->d_un.d_val & DF_BIND_NOW) 1118 obj->bind_now = true; 1119 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1120 ;*/ 1121 break; 1122 #ifdef __mips__ 1123 case DT_MIPS_LOCAL_GOTNO: 1124 obj->local_gotno = dynp->d_un.d_val; 1125 break; 1126 1127 case DT_MIPS_SYMTABNO: 1128 obj->symtabno = dynp->d_un.d_val; 1129 break; 1130 1131 case DT_MIPS_GOTSYM: 1132 obj->gotsym = dynp->d_un.d_val; 1133 break; 1134 1135 case DT_MIPS_RLD_MAP: 1136 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1137 break; 1138 #endif 1139 1140 case DT_FLAGS_1: 1141 if (dynp->d_un.d_val & DF_1_NOOPEN) 1142 obj->z_noopen = true; 1143 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1144 obj->z_origin = true; 1145 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1146 XXX ;*/ 1147 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1148 obj->bind_now = true; 1149 if (dynp->d_un.d_val & DF_1_NODELETE) 1150 obj->z_nodelete = true; 1151 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1152 obj->z_loadfltr = true; 1153 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1154 obj->z_interpose = true; 1155 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1156 obj->z_nodeflib = true; 1157 break; 1158 1159 default: 1160 if (!early) { 1161 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1162 (long)dynp->d_tag); 1163 } 1164 break; 1165 } 1166 } 1167 1168 obj->traced = false; 1169 1170 if (plttype == DT_RELA) { 1171 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1172 obj->pltrel = NULL; 1173 obj->pltrelasize = obj->pltrelsize; 1174 obj->pltrelsize = 0; 1175 } 1176 1177 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1178 if (obj->valid_hash_sysv) 1179 obj->dynsymcount = obj->nchains; 1180 else if (obj->valid_hash_gnu) { 1181 obj->dynsymcount = 0; 1182 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1183 if (obj->buckets_gnu[bkt] == 0) 1184 continue; 1185 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1186 do 1187 obj->dynsymcount++; 1188 while ((*hashval++ & 1u) == 0); 1189 } 1190 obj->dynsymcount += obj->symndx_gnu; 1191 } 1192 } 1193 1194 static void 1195 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1196 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1197 { 1198 1199 if (obj->z_origin && obj->origin_path == NULL) { 1200 obj->origin_path = xmalloc(PATH_MAX); 1201 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1202 die(); 1203 } 1204 1205 if (dyn_runpath != NULL) { 1206 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1207 if (obj->z_origin) 1208 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1209 } 1210 else if (dyn_rpath != NULL) { 1211 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1212 if (obj->z_origin) 1213 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1214 } 1215 1216 if (dyn_soname != NULL) 1217 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1218 } 1219 1220 static void 1221 digest_dynamic(Obj_Entry *obj, int early) 1222 { 1223 const Elf_Dyn *dyn_rpath; 1224 const Elf_Dyn *dyn_soname; 1225 const Elf_Dyn *dyn_runpath; 1226 1227 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1228 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1229 } 1230 1231 /* 1232 * Process a shared object's program header. This is used only for the 1233 * main program, when the kernel has already loaded the main program 1234 * into memory before calling the dynamic linker. It creates and 1235 * returns an Obj_Entry structure. 1236 */ 1237 static Obj_Entry * 1238 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1239 { 1240 Obj_Entry *obj; 1241 const Elf_Phdr *phlimit = phdr + phnum; 1242 const Elf_Phdr *ph; 1243 Elf_Addr note_start, note_end; 1244 int nsegs = 0; 1245 1246 obj = obj_new(); 1247 for (ph = phdr; ph < phlimit; ph++) { 1248 if (ph->p_type != PT_PHDR) 1249 continue; 1250 1251 obj->phdr = phdr; 1252 obj->phsize = ph->p_memsz; 1253 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1254 break; 1255 } 1256 1257 obj->stack_flags = PF_X | PF_R | PF_W; 1258 1259 for (ph = phdr; ph < phlimit; ph++) { 1260 switch (ph->p_type) { 1261 1262 case PT_INTERP: 1263 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1264 break; 1265 1266 case PT_LOAD: 1267 if (nsegs == 0) { /* First load segment */ 1268 obj->vaddrbase = trunc_page(ph->p_vaddr); 1269 obj->mapbase = obj->vaddrbase + obj->relocbase; 1270 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1271 obj->vaddrbase; 1272 } else { /* Last load segment */ 1273 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1274 obj->vaddrbase; 1275 } 1276 nsegs++; 1277 break; 1278 1279 case PT_DYNAMIC: 1280 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1281 break; 1282 1283 case PT_TLS: 1284 obj->tlsindex = 1; 1285 obj->tlssize = ph->p_memsz; 1286 obj->tlsalign = ph->p_align; 1287 obj->tlsinitsize = ph->p_filesz; 1288 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1289 break; 1290 1291 case PT_GNU_STACK: 1292 obj->stack_flags = ph->p_flags; 1293 break; 1294 1295 case PT_GNU_RELRO: 1296 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1297 obj->relro_size = round_page(ph->p_memsz); 1298 break; 1299 1300 case PT_NOTE: 1301 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1302 note_end = note_start + ph->p_filesz; 1303 digest_notes(obj, note_start, note_end); 1304 break; 1305 } 1306 } 1307 if (nsegs < 1) { 1308 _rtld_error("%s: too few PT_LOAD segments", path); 1309 return NULL; 1310 } 1311 1312 obj->entry = entry; 1313 return obj; 1314 } 1315 1316 void 1317 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1318 { 1319 const Elf_Note *note; 1320 const char *note_name; 1321 uintptr_t p; 1322 1323 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1324 note = (const Elf_Note *)((const char *)(note + 1) + 1325 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1326 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1327 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1328 note->n_descsz != sizeof(int32_t)) 1329 continue; 1330 if (note->n_type != ABI_NOTETYPE && 1331 note->n_type != CRT_NOINIT_NOTETYPE) 1332 continue; 1333 note_name = (const char *)(note + 1); 1334 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1335 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1336 continue; 1337 switch (note->n_type) { 1338 case ABI_NOTETYPE: 1339 /* FreeBSD osrel note */ 1340 p = (uintptr_t)(note + 1); 1341 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1342 obj->osrel = *(const int32_t *)(p); 1343 dbg("note osrel %d", obj->osrel); 1344 break; 1345 case CRT_NOINIT_NOTETYPE: 1346 /* FreeBSD 'crt does not call init' note */ 1347 obj->crt_no_init = true; 1348 dbg("note crt_no_init"); 1349 break; 1350 } 1351 } 1352 } 1353 1354 static Obj_Entry * 1355 dlcheck(void *handle) 1356 { 1357 Obj_Entry *obj; 1358 1359 for (obj = obj_list; obj != NULL; obj = obj->next) 1360 if (obj == (Obj_Entry *) handle) 1361 break; 1362 1363 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1364 _rtld_error("Invalid shared object handle %p", handle); 1365 return NULL; 1366 } 1367 return obj; 1368 } 1369 1370 /* 1371 * If the given object is already in the donelist, return true. Otherwise 1372 * add the object to the list and return false. 1373 */ 1374 static bool 1375 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1376 { 1377 unsigned int i; 1378 1379 for (i = 0; i < dlp->num_used; i++) 1380 if (dlp->objs[i] == obj) 1381 return true; 1382 /* 1383 * Our donelist allocation should always be sufficient. But if 1384 * our threads locking isn't working properly, more shared objects 1385 * could have been loaded since we allocated the list. That should 1386 * never happen, but we'll handle it properly just in case it does. 1387 */ 1388 if (dlp->num_used < dlp->num_alloc) 1389 dlp->objs[dlp->num_used++] = obj; 1390 return false; 1391 } 1392 1393 /* 1394 * Hash function for symbol table lookup. Don't even think about changing 1395 * this. It is specified by the System V ABI. 1396 */ 1397 unsigned long 1398 elf_hash(const char *name) 1399 { 1400 const unsigned char *p = (const unsigned char *) name; 1401 unsigned long h = 0; 1402 unsigned long g; 1403 1404 while (*p != '\0') { 1405 h = (h << 4) + *p++; 1406 if ((g = h & 0xf0000000) != 0) 1407 h ^= g >> 24; 1408 h &= ~g; 1409 } 1410 return h; 1411 } 1412 1413 /* 1414 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1415 * unsigned in case it's implemented with a wider type. 1416 */ 1417 static uint32_t 1418 gnu_hash(const char *s) 1419 { 1420 uint32_t h; 1421 unsigned char c; 1422 1423 h = 5381; 1424 for (c = *s; c != '\0'; c = *++s) 1425 h = h * 33 + c; 1426 return (h & 0xffffffff); 1427 } 1428 1429 1430 /* 1431 * Find the library with the given name, and return its full pathname. 1432 * The returned string is dynamically allocated. Generates an error 1433 * message and returns NULL if the library cannot be found. 1434 * 1435 * If the second argument is non-NULL, then it refers to an already- 1436 * loaded shared object, whose library search path will be searched. 1437 * 1438 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1439 * descriptor (which is close-on-exec) will be passed out via the third 1440 * argument. 1441 * 1442 * The search order is: 1443 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1444 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1445 * LD_LIBRARY_PATH 1446 * DT_RUNPATH in the referencing file 1447 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1448 * from list) 1449 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1450 * 1451 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1452 */ 1453 static char * 1454 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1455 { 1456 char *pathname; 1457 char *name; 1458 bool nodeflib, objgiven; 1459 1460 objgiven = refobj != NULL; 1461 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1462 if (xname[0] != '/' && !trust) { 1463 _rtld_error("Absolute pathname required for shared object \"%s\"", 1464 xname); 1465 return NULL; 1466 } 1467 if (objgiven && refobj->z_origin) { 1468 return (origin_subst(__DECONST(char *, xname), 1469 refobj->origin_path)); 1470 } else { 1471 return (xstrdup(xname)); 1472 } 1473 } 1474 1475 if (libmap_disable || !objgiven || 1476 (name = lm_find(refobj->path, xname)) == NULL) 1477 name = (char *)xname; 1478 1479 dbg(" Searching for \"%s\"", name); 1480 1481 /* 1482 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1483 * back to pre-conforming behaviour if user requested so with 1484 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1485 * nodeflib. 1486 */ 1487 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1488 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1489 (refobj != NULL && 1490 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1491 (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL || 1492 (pathname = search_library_path(name, gethints(false))) != NULL || 1493 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1494 return (pathname); 1495 } else { 1496 nodeflib = objgiven ? refobj->z_nodeflib : false; 1497 if ((objgiven && 1498 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1499 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1500 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1501 (pathname = search_library_path(name, ld_library_path)) != NULL || 1502 (objgiven && 1503 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1504 (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL || 1505 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1506 (objgiven && !nodeflib && 1507 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1508 return (pathname); 1509 } 1510 1511 if (objgiven && refobj->path != NULL) { 1512 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1513 name, basename(refobj->path)); 1514 } else { 1515 _rtld_error("Shared object \"%s\" not found", name); 1516 } 1517 return NULL; 1518 } 1519 1520 /* 1521 * Given a symbol number in a referencing object, find the corresponding 1522 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1523 * no definition was found. Returns a pointer to the Obj_Entry of the 1524 * defining object via the reference parameter DEFOBJ_OUT. 1525 */ 1526 const Elf_Sym * 1527 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1528 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1529 RtldLockState *lockstate) 1530 { 1531 const Elf_Sym *ref; 1532 const Elf_Sym *def; 1533 const Obj_Entry *defobj; 1534 SymLook req; 1535 const char *name; 1536 int res; 1537 1538 /* 1539 * If we have already found this symbol, get the information from 1540 * the cache. 1541 */ 1542 if (symnum >= refobj->dynsymcount) 1543 return NULL; /* Bad object */ 1544 if (cache != NULL && cache[symnum].sym != NULL) { 1545 *defobj_out = cache[symnum].obj; 1546 return cache[symnum].sym; 1547 } 1548 1549 ref = refobj->symtab + symnum; 1550 name = refobj->strtab + ref->st_name; 1551 def = NULL; 1552 defobj = NULL; 1553 1554 /* 1555 * We don't have to do a full scale lookup if the symbol is local. 1556 * We know it will bind to the instance in this load module; to 1557 * which we already have a pointer (ie ref). By not doing a lookup, 1558 * we not only improve performance, but it also avoids unresolvable 1559 * symbols when local symbols are not in the hash table. This has 1560 * been seen with the ia64 toolchain. 1561 */ 1562 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1563 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1564 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1565 symnum); 1566 } 1567 symlook_init(&req, name); 1568 req.flags = flags; 1569 req.ventry = fetch_ventry(refobj, symnum); 1570 req.lockstate = lockstate; 1571 res = symlook_default(&req, refobj); 1572 if (res == 0) { 1573 def = req.sym_out; 1574 defobj = req.defobj_out; 1575 } 1576 } else { 1577 def = ref; 1578 defobj = refobj; 1579 } 1580 1581 /* 1582 * If we found no definition and the reference is weak, treat the 1583 * symbol as having the value zero. 1584 */ 1585 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1586 def = &sym_zero; 1587 defobj = obj_main; 1588 } 1589 1590 if (def != NULL) { 1591 *defobj_out = defobj; 1592 /* Record the information in the cache to avoid subsequent lookups. */ 1593 if (cache != NULL) { 1594 cache[symnum].sym = def; 1595 cache[symnum].obj = defobj; 1596 } 1597 } else { 1598 if (refobj != &obj_rtld) 1599 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1600 } 1601 return def; 1602 } 1603 1604 /* 1605 * Return the search path from the ldconfig hints file, reading it if 1606 * necessary. If nostdlib is true, then the default search paths are 1607 * not added to result. 1608 * 1609 * Returns NULL if there are problems with the hints file, 1610 * or if the search path there is empty. 1611 */ 1612 static const char * 1613 gethints(bool nostdlib) 1614 { 1615 static char *hints, *filtered_path; 1616 struct elfhints_hdr hdr; 1617 struct fill_search_info_args sargs, hargs; 1618 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1619 struct dl_serpath *SLPpath, *hintpath; 1620 char *p; 1621 unsigned int SLPndx, hintndx, fndx, fcount; 1622 int fd; 1623 size_t flen; 1624 bool skip; 1625 1626 /* First call, read the hints file */ 1627 if (hints == NULL) { 1628 /* Keep from trying again in case the hints file is bad. */ 1629 hints = ""; 1630 1631 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1632 return (NULL); 1633 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1634 hdr.magic != ELFHINTS_MAGIC || 1635 hdr.version != 1) { 1636 close(fd); 1637 return (NULL); 1638 } 1639 p = xmalloc(hdr.dirlistlen + 1); 1640 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1641 read(fd, p, hdr.dirlistlen + 1) != 1642 (ssize_t)hdr.dirlistlen + 1) { 1643 free(p); 1644 close(fd); 1645 return (NULL); 1646 } 1647 hints = p; 1648 close(fd); 1649 } 1650 1651 /* 1652 * If caller agreed to receive list which includes the default 1653 * paths, we are done. Otherwise, if we still did not 1654 * calculated filtered result, do it now. 1655 */ 1656 if (!nostdlib) 1657 return (hints[0] != '\0' ? hints : NULL); 1658 if (filtered_path != NULL) 1659 goto filt_ret; 1660 1661 /* 1662 * Obtain the list of all configured search paths, and the 1663 * list of the default paths. 1664 * 1665 * First estimate the size of the results. 1666 */ 1667 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1668 smeta.dls_cnt = 0; 1669 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1670 hmeta.dls_cnt = 0; 1671 1672 sargs.request = RTLD_DI_SERINFOSIZE; 1673 sargs.serinfo = &smeta; 1674 hargs.request = RTLD_DI_SERINFOSIZE; 1675 hargs.serinfo = &hmeta; 1676 1677 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1678 path_enumerate(p, fill_search_info, &hargs); 1679 1680 SLPinfo = xmalloc(smeta.dls_size); 1681 hintinfo = xmalloc(hmeta.dls_size); 1682 1683 /* 1684 * Next fetch both sets of paths. 1685 */ 1686 sargs.request = RTLD_DI_SERINFO; 1687 sargs.serinfo = SLPinfo; 1688 sargs.serpath = &SLPinfo->dls_serpath[0]; 1689 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1690 1691 hargs.request = RTLD_DI_SERINFO; 1692 hargs.serinfo = hintinfo; 1693 hargs.serpath = &hintinfo->dls_serpath[0]; 1694 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1695 1696 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1697 path_enumerate(p, fill_search_info, &hargs); 1698 1699 /* 1700 * Now calculate the difference between two sets, by excluding 1701 * standard paths from the full set. 1702 */ 1703 fndx = 0; 1704 fcount = 0; 1705 filtered_path = xmalloc(hdr.dirlistlen + 1); 1706 hintpath = &hintinfo->dls_serpath[0]; 1707 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1708 skip = false; 1709 SLPpath = &SLPinfo->dls_serpath[0]; 1710 /* 1711 * Check each standard path against current. 1712 */ 1713 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1714 /* matched, skip the path */ 1715 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1716 skip = true; 1717 break; 1718 } 1719 } 1720 if (skip) 1721 continue; 1722 /* 1723 * Not matched against any standard path, add the path 1724 * to result. Separate consequtive paths with ':'. 1725 */ 1726 if (fcount > 0) { 1727 filtered_path[fndx] = ':'; 1728 fndx++; 1729 } 1730 fcount++; 1731 flen = strlen(hintpath->dls_name); 1732 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1733 fndx += flen; 1734 } 1735 filtered_path[fndx] = '\0'; 1736 1737 free(SLPinfo); 1738 free(hintinfo); 1739 1740 filt_ret: 1741 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1742 } 1743 1744 static void 1745 init_dag(Obj_Entry *root) 1746 { 1747 const Needed_Entry *needed; 1748 const Objlist_Entry *elm; 1749 DoneList donelist; 1750 1751 if (root->dag_inited) 1752 return; 1753 donelist_init(&donelist); 1754 1755 /* Root object belongs to own DAG. */ 1756 objlist_push_tail(&root->dldags, root); 1757 objlist_push_tail(&root->dagmembers, root); 1758 donelist_check(&donelist, root); 1759 1760 /* 1761 * Add dependencies of root object to DAG in breadth order 1762 * by exploiting the fact that each new object get added 1763 * to the tail of the dagmembers list. 1764 */ 1765 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1766 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1767 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1768 continue; 1769 objlist_push_tail(&needed->obj->dldags, root); 1770 objlist_push_tail(&root->dagmembers, needed->obj); 1771 } 1772 } 1773 root->dag_inited = true; 1774 } 1775 1776 static void 1777 process_nodelete(Obj_Entry *root) 1778 { 1779 const Objlist_Entry *elm; 1780 1781 /* 1782 * Walk over object DAG and process every dependent object that 1783 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1784 * which then should have its reference upped separately. 1785 */ 1786 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1787 if (elm->obj != NULL && elm->obj->z_nodelete && 1788 !elm->obj->ref_nodel) { 1789 dbg("obj %s nodelete", elm->obj->path); 1790 init_dag(elm->obj); 1791 ref_dag(elm->obj); 1792 elm->obj->ref_nodel = true; 1793 } 1794 } 1795 } 1796 /* 1797 * Initialize the dynamic linker. The argument is the address at which 1798 * the dynamic linker has been mapped into memory. The primary task of 1799 * this function is to relocate the dynamic linker. 1800 */ 1801 static void 1802 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1803 { 1804 Obj_Entry objtmp; /* Temporary rtld object */ 1805 const Elf_Dyn *dyn_rpath; 1806 const Elf_Dyn *dyn_soname; 1807 const Elf_Dyn *dyn_runpath; 1808 1809 #ifdef RTLD_INIT_PAGESIZES_EARLY 1810 /* The page size is required by the dynamic memory allocator. */ 1811 init_pagesizes(aux_info); 1812 #endif 1813 1814 /* 1815 * Conjure up an Obj_Entry structure for the dynamic linker. 1816 * 1817 * The "path" member can't be initialized yet because string constants 1818 * cannot yet be accessed. Below we will set it correctly. 1819 */ 1820 memset(&objtmp, 0, sizeof(objtmp)); 1821 objtmp.path = NULL; 1822 objtmp.rtld = true; 1823 objtmp.mapbase = mapbase; 1824 #ifdef PIC 1825 objtmp.relocbase = mapbase; 1826 #endif 1827 if (RTLD_IS_DYNAMIC()) { 1828 objtmp.dynamic = rtld_dynamic(&objtmp); 1829 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1830 assert(objtmp.needed == NULL); 1831 #if !defined(__mips__) 1832 /* MIPS has a bogus DT_TEXTREL. */ 1833 assert(!objtmp.textrel); 1834 #endif 1835 1836 /* 1837 * Temporarily put the dynamic linker entry into the object list, so 1838 * that symbols can be found. 1839 */ 1840 1841 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1842 } 1843 1844 /* Initialize the object list. */ 1845 obj_tail = &obj_list; 1846 1847 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1848 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1849 1850 #ifndef RTLD_INIT_PAGESIZES_EARLY 1851 /* The page size is required by the dynamic memory allocator. */ 1852 init_pagesizes(aux_info); 1853 #endif 1854 1855 if (aux_info[AT_OSRELDATE] != NULL) 1856 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1857 1858 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1859 1860 /* Replace the path with a dynamically allocated copy. */ 1861 obj_rtld.path = xstrdup(PATH_RTLD); 1862 1863 r_debug.r_brk = r_debug_state; 1864 r_debug.r_state = RT_CONSISTENT; 1865 } 1866 1867 /* 1868 * Retrieve the array of supported page sizes. The kernel provides the page 1869 * sizes in increasing order. 1870 */ 1871 static void 1872 init_pagesizes(Elf_Auxinfo **aux_info) 1873 { 1874 static size_t psa[MAXPAGESIZES]; 1875 int mib[2]; 1876 size_t len, size; 1877 1878 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 1879 NULL) { 1880 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 1881 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 1882 } else { 1883 len = 2; 1884 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 1885 size = sizeof(psa); 1886 else { 1887 /* As a fallback, retrieve the base page size. */ 1888 size = sizeof(psa[0]); 1889 if (aux_info[AT_PAGESZ] != NULL) { 1890 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 1891 goto psa_filled; 1892 } else { 1893 mib[0] = CTL_HW; 1894 mib[1] = HW_PAGESIZE; 1895 len = 2; 1896 } 1897 } 1898 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 1899 _rtld_error("sysctl for hw.pagesize(s) failed"); 1900 die(); 1901 } 1902 psa_filled: 1903 pagesizes = psa; 1904 } 1905 npagesizes = size / sizeof(pagesizes[0]); 1906 /* Discard any invalid entries at the end of the array. */ 1907 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 1908 npagesizes--; 1909 } 1910 1911 /* 1912 * Add the init functions from a needed object list (and its recursive 1913 * needed objects) to "list". This is not used directly; it is a helper 1914 * function for initlist_add_objects(). The write lock must be held 1915 * when this function is called. 1916 */ 1917 static void 1918 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1919 { 1920 /* Recursively process the successor needed objects. */ 1921 if (needed->next != NULL) 1922 initlist_add_neededs(needed->next, list); 1923 1924 /* Process the current needed object. */ 1925 if (needed->obj != NULL) 1926 initlist_add_objects(needed->obj, &needed->obj->next, list); 1927 } 1928 1929 /* 1930 * Scan all of the DAGs rooted in the range of objects from "obj" to 1931 * "tail" and add their init functions to "list". This recurses over 1932 * the DAGs and ensure the proper init ordering such that each object's 1933 * needed libraries are initialized before the object itself. At the 1934 * same time, this function adds the objects to the global finalization 1935 * list "list_fini" in the opposite order. The write lock must be 1936 * held when this function is called. 1937 */ 1938 static void 1939 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1940 { 1941 1942 if (obj->init_scanned || obj->init_done) 1943 return; 1944 obj->init_scanned = true; 1945 1946 /* Recursively process the successor objects. */ 1947 if (&obj->next != tail) 1948 initlist_add_objects(obj->next, tail, list); 1949 1950 /* Recursively process the needed objects. */ 1951 if (obj->needed != NULL) 1952 initlist_add_neededs(obj->needed, list); 1953 if (obj->needed_filtees != NULL) 1954 initlist_add_neededs(obj->needed_filtees, list); 1955 if (obj->needed_aux_filtees != NULL) 1956 initlist_add_neededs(obj->needed_aux_filtees, list); 1957 1958 /* Add the object to the init list. */ 1959 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1960 obj->init_array != (Elf_Addr)NULL) 1961 objlist_push_tail(list, obj); 1962 1963 /* Add the object to the global fini list in the reverse order. */ 1964 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1965 && !obj->on_fini_list) { 1966 objlist_push_head(&list_fini, obj); 1967 obj->on_fini_list = true; 1968 } 1969 } 1970 1971 #ifndef FPTR_TARGET 1972 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 1973 #endif 1974 1975 static void 1976 free_needed_filtees(Needed_Entry *n) 1977 { 1978 Needed_Entry *needed, *needed1; 1979 1980 for (needed = n; needed != NULL; needed = needed->next) { 1981 if (needed->obj != NULL) { 1982 dlclose(needed->obj); 1983 needed->obj = NULL; 1984 } 1985 } 1986 for (needed = n; needed != NULL; needed = needed1) { 1987 needed1 = needed->next; 1988 free(needed); 1989 } 1990 } 1991 1992 static void 1993 unload_filtees(Obj_Entry *obj) 1994 { 1995 1996 free_needed_filtees(obj->needed_filtees); 1997 obj->needed_filtees = NULL; 1998 free_needed_filtees(obj->needed_aux_filtees); 1999 obj->needed_aux_filtees = NULL; 2000 obj->filtees_loaded = false; 2001 } 2002 2003 static void 2004 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2005 RtldLockState *lockstate) 2006 { 2007 2008 for (; needed != NULL; needed = needed->next) { 2009 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2010 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2011 RTLD_LOCAL, lockstate); 2012 } 2013 } 2014 2015 static void 2016 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2017 { 2018 2019 lock_restart_for_upgrade(lockstate); 2020 if (!obj->filtees_loaded) { 2021 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2022 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2023 obj->filtees_loaded = true; 2024 } 2025 } 2026 2027 static int 2028 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2029 { 2030 Obj_Entry *obj1; 2031 2032 for (; needed != NULL; needed = needed->next) { 2033 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2034 flags & ~RTLD_LO_NOLOAD); 2035 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2036 return (-1); 2037 } 2038 return (0); 2039 } 2040 2041 /* 2042 * Given a shared object, traverse its list of needed objects, and load 2043 * each of them. Returns 0 on success. Generates an error message and 2044 * returns -1 on failure. 2045 */ 2046 static int 2047 load_needed_objects(Obj_Entry *first, int flags) 2048 { 2049 Obj_Entry *obj; 2050 2051 for (obj = first; obj != NULL; obj = obj->next) { 2052 if (process_needed(obj, obj->needed, flags) == -1) 2053 return (-1); 2054 } 2055 return (0); 2056 } 2057 2058 static int 2059 load_preload_objects(void) 2060 { 2061 char *p = ld_preload; 2062 Obj_Entry *obj; 2063 static const char delim[] = " \t:;"; 2064 2065 if (p == NULL) 2066 return 0; 2067 2068 p += strspn(p, delim); 2069 while (*p != '\0') { 2070 size_t len = strcspn(p, delim); 2071 char savech; 2072 2073 savech = p[len]; 2074 p[len] = '\0'; 2075 obj = load_object(p, -1, NULL, 0); 2076 if (obj == NULL) 2077 return -1; /* XXX - cleanup */ 2078 obj->z_interpose = true; 2079 p[len] = savech; 2080 p += len; 2081 p += strspn(p, delim); 2082 } 2083 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2084 return 0; 2085 } 2086 2087 static const char * 2088 printable_path(const char *path) 2089 { 2090 2091 return (path == NULL ? "<unknown>" : path); 2092 } 2093 2094 /* 2095 * Load a shared object into memory, if it is not already loaded. The 2096 * object may be specified by name or by user-supplied file descriptor 2097 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2098 * duplicate is. 2099 * 2100 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2101 * on failure. 2102 */ 2103 static Obj_Entry * 2104 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2105 { 2106 Obj_Entry *obj; 2107 int fd; 2108 struct stat sb; 2109 char *path; 2110 2111 fd = -1; 2112 if (name != NULL) { 2113 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2114 if (object_match_name(obj, name)) 2115 return (obj); 2116 } 2117 2118 path = find_library(name, refobj, &fd); 2119 if (path == NULL) 2120 return (NULL); 2121 } else 2122 path = NULL; 2123 2124 if (fd >= 0) { 2125 /* 2126 * search_library_pathfds() opens a fresh file descriptor for the 2127 * library, so there is no need to dup(). 2128 */ 2129 } else if (fd_u == -1) { 2130 /* 2131 * If we didn't find a match by pathname, or the name is not 2132 * supplied, open the file and check again by device and inode. 2133 * This avoids false mismatches caused by multiple links or ".." 2134 * in pathnames. 2135 * 2136 * To avoid a race, we open the file and use fstat() rather than 2137 * using stat(). 2138 */ 2139 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2140 _rtld_error("Cannot open \"%s\"", path); 2141 free(path); 2142 return (NULL); 2143 } 2144 } else { 2145 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2146 if (fd == -1) { 2147 _rtld_error("Cannot dup fd"); 2148 free(path); 2149 return (NULL); 2150 } 2151 } 2152 if (fstat(fd, &sb) == -1) { 2153 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2154 close(fd); 2155 free(path); 2156 return NULL; 2157 } 2158 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2159 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2160 break; 2161 if (obj != NULL && name != NULL) { 2162 object_add_name(obj, name); 2163 free(path); 2164 close(fd); 2165 return obj; 2166 } 2167 if (flags & RTLD_LO_NOLOAD) { 2168 free(path); 2169 close(fd); 2170 return (NULL); 2171 } 2172 2173 /* First use of this object, so we must map it in */ 2174 obj = do_load_object(fd, name, path, &sb, flags); 2175 if (obj == NULL) 2176 free(path); 2177 close(fd); 2178 2179 return obj; 2180 } 2181 2182 static Obj_Entry * 2183 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2184 int flags) 2185 { 2186 Obj_Entry *obj; 2187 struct statfs fs; 2188 2189 /* 2190 * but first, make sure that environment variables haven't been 2191 * used to circumvent the noexec flag on a filesystem. 2192 */ 2193 if (dangerous_ld_env) { 2194 if (fstatfs(fd, &fs) != 0) { 2195 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2196 return NULL; 2197 } 2198 if (fs.f_flags & MNT_NOEXEC) { 2199 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2200 return NULL; 2201 } 2202 } 2203 dbg("loading \"%s\"", printable_path(path)); 2204 obj = map_object(fd, printable_path(path), sbp); 2205 if (obj == NULL) 2206 return NULL; 2207 2208 /* 2209 * If DT_SONAME is present in the object, digest_dynamic2 already 2210 * added it to the object names. 2211 */ 2212 if (name != NULL) 2213 object_add_name(obj, name); 2214 obj->path = path; 2215 digest_dynamic(obj, 0); 2216 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2217 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2218 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2219 RTLD_LO_DLOPEN) { 2220 dbg("refusing to load non-loadable \"%s\"", obj->path); 2221 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2222 munmap(obj->mapbase, obj->mapsize); 2223 obj_free(obj); 2224 return (NULL); 2225 } 2226 2227 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2228 *obj_tail = obj; 2229 obj_tail = &obj->next; 2230 obj_count++; 2231 obj_loads++; 2232 linkmap_add(obj); /* for GDB & dlinfo() */ 2233 max_stack_flags |= obj->stack_flags; 2234 2235 dbg(" %p .. %p: %s", obj->mapbase, 2236 obj->mapbase + obj->mapsize - 1, obj->path); 2237 if (obj->textrel) 2238 dbg(" WARNING: %s has impure text", obj->path); 2239 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2240 obj->path); 2241 2242 return obj; 2243 } 2244 2245 static Obj_Entry * 2246 obj_from_addr(const void *addr) 2247 { 2248 Obj_Entry *obj; 2249 2250 for (obj = obj_list; obj != NULL; obj = obj->next) { 2251 if (addr < (void *) obj->mapbase) 2252 continue; 2253 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2254 return obj; 2255 } 2256 return NULL; 2257 } 2258 2259 static void 2260 preinit_main(void) 2261 { 2262 Elf_Addr *preinit_addr; 2263 int index; 2264 2265 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2266 if (preinit_addr == NULL) 2267 return; 2268 2269 for (index = 0; index < obj_main->preinit_array_num; index++) { 2270 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2271 dbg("calling preinit function for %s at %p", obj_main->path, 2272 (void *)preinit_addr[index]); 2273 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2274 0, 0, obj_main->path); 2275 call_init_pointer(obj_main, preinit_addr[index]); 2276 } 2277 } 2278 } 2279 2280 /* 2281 * Call the finalization functions for each of the objects in "list" 2282 * belonging to the DAG of "root" and referenced once. If NULL "root" 2283 * is specified, every finalization function will be called regardless 2284 * of the reference count and the list elements won't be freed. All of 2285 * the objects are expected to have non-NULL fini functions. 2286 */ 2287 static void 2288 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2289 { 2290 Objlist_Entry *elm; 2291 char *saved_msg; 2292 Elf_Addr *fini_addr; 2293 int index; 2294 2295 assert(root == NULL || root->refcount == 1); 2296 2297 /* 2298 * Preserve the current error message since a fini function might 2299 * call into the dynamic linker and overwrite it. 2300 */ 2301 saved_msg = errmsg_save(); 2302 do { 2303 STAILQ_FOREACH(elm, list, link) { 2304 if (root != NULL && (elm->obj->refcount != 1 || 2305 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2306 continue; 2307 /* Remove object from fini list to prevent recursive invocation. */ 2308 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2309 /* 2310 * XXX: If a dlopen() call references an object while the 2311 * fini function is in progress, we might end up trying to 2312 * unload the referenced object in dlclose() or the object 2313 * won't be unloaded although its fini function has been 2314 * called. 2315 */ 2316 lock_release(rtld_bind_lock, lockstate); 2317 2318 /* 2319 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2320 * When this happens, DT_FINI_ARRAY is processed first. 2321 */ 2322 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2323 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2324 for (index = elm->obj->fini_array_num - 1; index >= 0; 2325 index--) { 2326 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2327 dbg("calling fini function for %s at %p", 2328 elm->obj->path, (void *)fini_addr[index]); 2329 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2330 (void *)fini_addr[index], 0, 0, elm->obj->path); 2331 call_initfini_pointer(elm->obj, fini_addr[index]); 2332 } 2333 } 2334 } 2335 if (elm->obj->fini != (Elf_Addr)NULL) { 2336 dbg("calling fini function for %s at %p", elm->obj->path, 2337 (void *)elm->obj->fini); 2338 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2339 0, 0, elm->obj->path); 2340 call_initfini_pointer(elm->obj, elm->obj->fini); 2341 } 2342 wlock_acquire(rtld_bind_lock, lockstate); 2343 /* No need to free anything if process is going down. */ 2344 if (root != NULL) 2345 free(elm); 2346 /* 2347 * We must restart the list traversal after every fini call 2348 * because a dlclose() call from the fini function or from 2349 * another thread might have modified the reference counts. 2350 */ 2351 break; 2352 } 2353 } while (elm != NULL); 2354 errmsg_restore(saved_msg); 2355 } 2356 2357 /* 2358 * Call the initialization functions for each of the objects in 2359 * "list". All of the objects are expected to have non-NULL init 2360 * functions. 2361 */ 2362 static void 2363 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2364 { 2365 Objlist_Entry *elm; 2366 Obj_Entry *obj; 2367 char *saved_msg; 2368 Elf_Addr *init_addr; 2369 int index; 2370 2371 /* 2372 * Clean init_scanned flag so that objects can be rechecked and 2373 * possibly initialized earlier if any of vectors called below 2374 * cause the change by using dlopen. 2375 */ 2376 for (obj = obj_list; obj != NULL; obj = obj->next) 2377 obj->init_scanned = false; 2378 2379 /* 2380 * Preserve the current error message since an init function might 2381 * call into the dynamic linker and overwrite it. 2382 */ 2383 saved_msg = errmsg_save(); 2384 STAILQ_FOREACH(elm, list, link) { 2385 if (elm->obj->init_done) /* Initialized early. */ 2386 continue; 2387 /* 2388 * Race: other thread might try to use this object before current 2389 * one completes the initilization. Not much can be done here 2390 * without better locking. 2391 */ 2392 elm->obj->init_done = true; 2393 lock_release(rtld_bind_lock, lockstate); 2394 2395 /* 2396 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2397 * When this happens, DT_INIT is processed first. 2398 */ 2399 if (elm->obj->init != (Elf_Addr)NULL) { 2400 dbg("calling init function for %s at %p", elm->obj->path, 2401 (void *)elm->obj->init); 2402 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2403 0, 0, elm->obj->path); 2404 call_initfini_pointer(elm->obj, elm->obj->init); 2405 } 2406 init_addr = (Elf_Addr *)elm->obj->init_array; 2407 if (init_addr != NULL) { 2408 for (index = 0; index < elm->obj->init_array_num; index++) { 2409 if (init_addr[index] != 0 && init_addr[index] != 1) { 2410 dbg("calling init function for %s at %p", elm->obj->path, 2411 (void *)init_addr[index]); 2412 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2413 (void *)init_addr[index], 0, 0, elm->obj->path); 2414 call_init_pointer(elm->obj, init_addr[index]); 2415 } 2416 } 2417 } 2418 wlock_acquire(rtld_bind_lock, lockstate); 2419 } 2420 errmsg_restore(saved_msg); 2421 } 2422 2423 static void 2424 objlist_clear(Objlist *list) 2425 { 2426 Objlist_Entry *elm; 2427 2428 while (!STAILQ_EMPTY(list)) { 2429 elm = STAILQ_FIRST(list); 2430 STAILQ_REMOVE_HEAD(list, link); 2431 free(elm); 2432 } 2433 } 2434 2435 static Objlist_Entry * 2436 objlist_find(Objlist *list, const Obj_Entry *obj) 2437 { 2438 Objlist_Entry *elm; 2439 2440 STAILQ_FOREACH(elm, list, link) 2441 if (elm->obj == obj) 2442 return elm; 2443 return NULL; 2444 } 2445 2446 static void 2447 objlist_init(Objlist *list) 2448 { 2449 STAILQ_INIT(list); 2450 } 2451 2452 static void 2453 objlist_push_head(Objlist *list, Obj_Entry *obj) 2454 { 2455 Objlist_Entry *elm; 2456 2457 elm = NEW(Objlist_Entry); 2458 elm->obj = obj; 2459 STAILQ_INSERT_HEAD(list, elm, link); 2460 } 2461 2462 static void 2463 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2464 { 2465 Objlist_Entry *elm; 2466 2467 elm = NEW(Objlist_Entry); 2468 elm->obj = obj; 2469 STAILQ_INSERT_TAIL(list, elm, link); 2470 } 2471 2472 static void 2473 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2474 { 2475 Objlist_Entry *elm, *listelm; 2476 2477 STAILQ_FOREACH(listelm, list, link) { 2478 if (listelm->obj == listobj) 2479 break; 2480 } 2481 elm = NEW(Objlist_Entry); 2482 elm->obj = obj; 2483 if (listelm != NULL) 2484 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2485 else 2486 STAILQ_INSERT_TAIL(list, elm, link); 2487 } 2488 2489 static void 2490 objlist_remove(Objlist *list, Obj_Entry *obj) 2491 { 2492 Objlist_Entry *elm; 2493 2494 if ((elm = objlist_find(list, obj)) != NULL) { 2495 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2496 free(elm); 2497 } 2498 } 2499 2500 /* 2501 * Relocate dag rooted in the specified object. 2502 * Returns 0 on success, or -1 on failure. 2503 */ 2504 2505 static int 2506 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2507 int flags, RtldLockState *lockstate) 2508 { 2509 Objlist_Entry *elm; 2510 int error; 2511 2512 error = 0; 2513 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2514 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2515 lockstate); 2516 if (error == -1) 2517 break; 2518 } 2519 return (error); 2520 } 2521 2522 /* 2523 * Relocate single object. 2524 * Returns 0 on success, or -1 on failure. 2525 */ 2526 static int 2527 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2528 int flags, RtldLockState *lockstate) 2529 { 2530 2531 if (obj->relocated) 2532 return (0); 2533 obj->relocated = true; 2534 if (obj != rtldobj) 2535 dbg("relocating \"%s\"", obj->path); 2536 2537 if (obj->symtab == NULL || obj->strtab == NULL || 2538 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2539 _rtld_error("%s: Shared object has no run-time symbol table", 2540 obj->path); 2541 return (-1); 2542 } 2543 2544 if (obj->textrel) { 2545 /* There are relocations to the write-protected text segment. */ 2546 if (mprotect(obj->mapbase, obj->textsize, 2547 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2548 _rtld_error("%s: Cannot write-enable text segment: %s", 2549 obj->path, rtld_strerror(errno)); 2550 return (-1); 2551 } 2552 } 2553 2554 /* Process the non-PLT non-IFUNC relocations. */ 2555 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2556 return (-1); 2557 2558 if (obj->textrel) { /* Re-protected the text segment. */ 2559 if (mprotect(obj->mapbase, obj->textsize, 2560 PROT_READ|PROT_EXEC) == -1) { 2561 _rtld_error("%s: Cannot write-protect text segment: %s", 2562 obj->path, rtld_strerror(errno)); 2563 return (-1); 2564 } 2565 } 2566 2567 /* Set the special PLT or GOT entries. */ 2568 init_pltgot(obj); 2569 2570 /* Process the PLT relocations. */ 2571 if (reloc_plt(obj) == -1) 2572 return (-1); 2573 /* Relocate the jump slots if we are doing immediate binding. */ 2574 if (obj->bind_now || bind_now) 2575 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2576 return (-1); 2577 2578 /* 2579 * Process the non-PLT IFUNC relocations. The relocations are 2580 * processed in two phases, because IFUNC resolvers may 2581 * reference other symbols, which must be readily processed 2582 * before resolvers are called. 2583 */ 2584 if (obj->non_plt_gnu_ifunc && 2585 reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate)) 2586 return (-1); 2587 2588 if (obj->relro_size > 0) { 2589 if (mprotect(obj->relro_page, obj->relro_size, 2590 PROT_READ) == -1) { 2591 _rtld_error("%s: Cannot enforce relro protection: %s", 2592 obj->path, rtld_strerror(errno)); 2593 return (-1); 2594 } 2595 } 2596 2597 /* 2598 * Set up the magic number and version in the Obj_Entry. These 2599 * were checked in the crt1.o from the original ElfKit, so we 2600 * set them for backward compatibility. 2601 */ 2602 obj->magic = RTLD_MAGIC; 2603 obj->version = RTLD_VERSION; 2604 2605 return (0); 2606 } 2607 2608 /* 2609 * Relocate newly-loaded shared objects. The argument is a pointer to 2610 * the Obj_Entry for the first such object. All objects from the first 2611 * to the end of the list of objects are relocated. Returns 0 on success, 2612 * or -1 on failure. 2613 */ 2614 static int 2615 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2616 int flags, RtldLockState *lockstate) 2617 { 2618 Obj_Entry *obj; 2619 int error; 2620 2621 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2622 error = relocate_object(obj, bind_now, rtldobj, flags, 2623 lockstate); 2624 if (error == -1) 2625 break; 2626 } 2627 return (error); 2628 } 2629 2630 /* 2631 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2632 * referencing STT_GNU_IFUNC symbols is postponed till the other 2633 * relocations are done. The indirect functions specified as 2634 * ifunc are allowed to call other symbols, so we need to have 2635 * objects relocated before asking for resolution from indirects. 2636 * 2637 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2638 * instead of the usual lazy handling of PLT slots. It is 2639 * consistent with how GNU does it. 2640 */ 2641 static int 2642 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2643 RtldLockState *lockstate) 2644 { 2645 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2646 return (-1); 2647 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2648 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2649 return (-1); 2650 return (0); 2651 } 2652 2653 static int 2654 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2655 RtldLockState *lockstate) 2656 { 2657 Obj_Entry *obj; 2658 2659 for (obj = first; obj != NULL; obj = obj->next) { 2660 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2661 return (-1); 2662 } 2663 return (0); 2664 } 2665 2666 static int 2667 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2668 RtldLockState *lockstate) 2669 { 2670 Objlist_Entry *elm; 2671 2672 STAILQ_FOREACH(elm, list, link) { 2673 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2674 lockstate) == -1) 2675 return (-1); 2676 } 2677 return (0); 2678 } 2679 2680 /* 2681 * Cleanup procedure. It will be called (by the atexit mechanism) just 2682 * before the process exits. 2683 */ 2684 static void 2685 rtld_exit(void) 2686 { 2687 RtldLockState lockstate; 2688 2689 wlock_acquire(rtld_bind_lock, &lockstate); 2690 dbg("rtld_exit()"); 2691 objlist_call_fini(&list_fini, NULL, &lockstate); 2692 /* No need to remove the items from the list, since we are exiting. */ 2693 if (!libmap_disable) 2694 lm_fini(); 2695 lock_release(rtld_bind_lock, &lockstate); 2696 } 2697 2698 /* 2699 * Iterate over a search path, translate each element, and invoke the 2700 * callback on the result. 2701 */ 2702 static void * 2703 path_enumerate(const char *path, path_enum_proc callback, void *arg) 2704 { 2705 const char *trans; 2706 if (path == NULL) 2707 return (NULL); 2708 2709 path += strspn(path, ":;"); 2710 while (*path != '\0') { 2711 size_t len; 2712 char *res; 2713 2714 len = strcspn(path, ":;"); 2715 trans = lm_findn(NULL, path, len); 2716 if (trans) 2717 res = callback(trans, strlen(trans), arg); 2718 else 2719 res = callback(path, len, arg); 2720 2721 if (res != NULL) 2722 return (res); 2723 2724 path += len; 2725 path += strspn(path, ":;"); 2726 } 2727 2728 return (NULL); 2729 } 2730 2731 struct try_library_args { 2732 const char *name; 2733 size_t namelen; 2734 char *buffer; 2735 size_t buflen; 2736 }; 2737 2738 static void * 2739 try_library_path(const char *dir, size_t dirlen, void *param) 2740 { 2741 struct try_library_args *arg; 2742 2743 arg = param; 2744 if (*dir == '/' || trust) { 2745 char *pathname; 2746 2747 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2748 return (NULL); 2749 2750 pathname = arg->buffer; 2751 strncpy(pathname, dir, dirlen); 2752 pathname[dirlen] = '/'; 2753 strcpy(pathname + dirlen + 1, arg->name); 2754 2755 dbg(" Trying \"%s\"", pathname); 2756 if (access(pathname, F_OK) == 0) { /* We found it */ 2757 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2758 strcpy(pathname, arg->buffer); 2759 return (pathname); 2760 } 2761 } 2762 return (NULL); 2763 } 2764 2765 static char * 2766 search_library_path(const char *name, const char *path) 2767 { 2768 char *p; 2769 struct try_library_args arg; 2770 2771 if (path == NULL) 2772 return NULL; 2773 2774 arg.name = name; 2775 arg.namelen = strlen(name); 2776 arg.buffer = xmalloc(PATH_MAX); 2777 arg.buflen = PATH_MAX; 2778 2779 p = path_enumerate(path, try_library_path, &arg); 2780 2781 free(arg.buffer); 2782 2783 return (p); 2784 } 2785 2786 2787 /* 2788 * Finds the library with the given name using the directory descriptors 2789 * listed in the LD_LIBRARY_PATH_FDS environment variable. 2790 * 2791 * Returns a freshly-opened close-on-exec file descriptor for the library, 2792 * or -1 if the library cannot be found. 2793 */ 2794 static char * 2795 search_library_pathfds(const char *name, const char *path, int *fdp) 2796 { 2797 char *envcopy, *fdstr, *found, *last_token; 2798 size_t len; 2799 int dirfd, fd; 2800 2801 dbg("%s('%s', '%s', fdp)", __func__, name, path); 2802 2803 /* Don't load from user-specified libdirs into setuid binaries. */ 2804 if (!trust) 2805 return (NULL); 2806 2807 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 2808 if (path == NULL) 2809 return (NULL); 2810 2811 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 2812 if (name[0] == '/') { 2813 dbg("Absolute path (%s) passed to %s", name, __func__); 2814 return (NULL); 2815 } 2816 2817 /* 2818 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 2819 * copy of the path, as strtok_r rewrites separator tokens 2820 * with '\0'. 2821 */ 2822 found = NULL; 2823 envcopy = xstrdup(path); 2824 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 2825 fdstr = strtok_r(NULL, ":", &last_token)) { 2826 dirfd = parse_libdir(fdstr); 2827 if (dirfd < 0) 2828 break; 2829 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC); 2830 if (fd >= 0) { 2831 *fdp = fd; 2832 len = strlen(fdstr) + strlen(name) + 3; 2833 found = xmalloc(len); 2834 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 2835 _rtld_error("error generating '%d/%s'", 2836 dirfd, name); 2837 die(); 2838 } 2839 dbg("open('%s') => %d", found, fd); 2840 break; 2841 } 2842 } 2843 free(envcopy); 2844 2845 return (found); 2846 } 2847 2848 2849 int 2850 dlclose(void *handle) 2851 { 2852 Obj_Entry *root; 2853 RtldLockState lockstate; 2854 2855 wlock_acquire(rtld_bind_lock, &lockstate); 2856 root = dlcheck(handle); 2857 if (root == NULL) { 2858 lock_release(rtld_bind_lock, &lockstate); 2859 return -1; 2860 } 2861 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2862 root->path); 2863 2864 /* Unreference the object and its dependencies. */ 2865 root->dl_refcount--; 2866 2867 if (root->refcount == 1) { 2868 /* 2869 * The object will be no longer referenced, so we must unload it. 2870 * First, call the fini functions. 2871 */ 2872 objlist_call_fini(&list_fini, root, &lockstate); 2873 2874 unref_dag(root); 2875 2876 /* Finish cleaning up the newly-unreferenced objects. */ 2877 GDB_STATE(RT_DELETE,&root->linkmap); 2878 unload_object(root); 2879 GDB_STATE(RT_CONSISTENT,NULL); 2880 } else 2881 unref_dag(root); 2882 2883 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2884 lock_release(rtld_bind_lock, &lockstate); 2885 return 0; 2886 } 2887 2888 char * 2889 dlerror(void) 2890 { 2891 char *msg = error_message; 2892 error_message = NULL; 2893 return msg; 2894 } 2895 2896 /* 2897 * This function is deprecated and has no effect. 2898 */ 2899 void 2900 dllockinit(void *context, 2901 void *(*lock_create)(void *context), 2902 void (*rlock_acquire)(void *lock), 2903 void (*wlock_acquire)(void *lock), 2904 void (*lock_release)(void *lock), 2905 void (*lock_destroy)(void *lock), 2906 void (*context_destroy)(void *context)) 2907 { 2908 static void *cur_context; 2909 static void (*cur_context_destroy)(void *); 2910 2911 /* Just destroy the context from the previous call, if necessary. */ 2912 if (cur_context_destroy != NULL) 2913 cur_context_destroy(cur_context); 2914 cur_context = context; 2915 cur_context_destroy = context_destroy; 2916 } 2917 2918 void * 2919 dlopen(const char *name, int mode) 2920 { 2921 2922 return (rtld_dlopen(name, -1, mode)); 2923 } 2924 2925 void * 2926 fdlopen(int fd, int mode) 2927 { 2928 2929 return (rtld_dlopen(NULL, fd, mode)); 2930 } 2931 2932 static void * 2933 rtld_dlopen(const char *name, int fd, int mode) 2934 { 2935 RtldLockState lockstate; 2936 int lo_flags; 2937 2938 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2939 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2940 if (ld_tracing != NULL) { 2941 rlock_acquire(rtld_bind_lock, &lockstate); 2942 if (sigsetjmp(lockstate.env, 0) != 0) 2943 lock_upgrade(rtld_bind_lock, &lockstate); 2944 environ = (char **)*get_program_var_addr("environ", &lockstate); 2945 lock_release(rtld_bind_lock, &lockstate); 2946 } 2947 lo_flags = RTLD_LO_DLOPEN; 2948 if (mode & RTLD_NODELETE) 2949 lo_flags |= RTLD_LO_NODELETE; 2950 if (mode & RTLD_NOLOAD) 2951 lo_flags |= RTLD_LO_NOLOAD; 2952 if (ld_tracing != NULL) 2953 lo_flags |= RTLD_LO_TRACE; 2954 2955 return (dlopen_object(name, fd, obj_main, lo_flags, 2956 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2957 } 2958 2959 static void 2960 dlopen_cleanup(Obj_Entry *obj) 2961 { 2962 2963 obj->dl_refcount--; 2964 unref_dag(obj); 2965 if (obj->refcount == 0) 2966 unload_object(obj); 2967 } 2968 2969 static Obj_Entry * 2970 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2971 int mode, RtldLockState *lockstate) 2972 { 2973 Obj_Entry **old_obj_tail; 2974 Obj_Entry *obj; 2975 Objlist initlist; 2976 RtldLockState mlockstate; 2977 int result; 2978 2979 objlist_init(&initlist); 2980 2981 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2982 wlock_acquire(rtld_bind_lock, &mlockstate); 2983 lockstate = &mlockstate; 2984 } 2985 GDB_STATE(RT_ADD,NULL); 2986 2987 old_obj_tail = obj_tail; 2988 obj = NULL; 2989 if (name == NULL && fd == -1) { 2990 obj = obj_main; 2991 obj->refcount++; 2992 } else { 2993 obj = load_object(name, fd, refobj, lo_flags); 2994 } 2995 2996 if (obj) { 2997 obj->dl_refcount++; 2998 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2999 objlist_push_tail(&list_global, obj); 3000 if (*old_obj_tail != NULL) { /* We loaded something new. */ 3001 assert(*old_obj_tail == obj); 3002 result = load_needed_objects(obj, 3003 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 3004 init_dag(obj); 3005 ref_dag(obj); 3006 if (result != -1) 3007 result = rtld_verify_versions(&obj->dagmembers); 3008 if (result != -1 && ld_tracing) 3009 goto trace; 3010 if (result == -1 || relocate_object_dag(obj, 3011 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3012 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3013 lockstate) == -1) { 3014 dlopen_cleanup(obj); 3015 obj = NULL; 3016 } else if (lo_flags & RTLD_LO_EARLY) { 3017 /* 3018 * Do not call the init functions for early loaded 3019 * filtees. The image is still not initialized enough 3020 * for them to work. 3021 * 3022 * Our object is found by the global object list and 3023 * will be ordered among all init calls done right 3024 * before transferring control to main. 3025 */ 3026 } else { 3027 /* Make list of init functions to call. */ 3028 initlist_add_objects(obj, &obj->next, &initlist); 3029 } 3030 /* 3031 * Process all no_delete objects here, given them own 3032 * DAGs to prevent their dependencies from being unloaded. 3033 * This has to be done after we have loaded all of the 3034 * dependencies, so that we do not miss any. 3035 */ 3036 if (obj != NULL) 3037 process_nodelete(obj); 3038 } else { 3039 /* 3040 * Bump the reference counts for objects on this DAG. If 3041 * this is the first dlopen() call for the object that was 3042 * already loaded as a dependency, initialize the dag 3043 * starting at it. 3044 */ 3045 init_dag(obj); 3046 ref_dag(obj); 3047 3048 if ((lo_flags & RTLD_LO_TRACE) != 0) 3049 goto trace; 3050 } 3051 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3052 obj->z_nodelete) && !obj->ref_nodel) { 3053 dbg("obj %s nodelete", obj->path); 3054 ref_dag(obj); 3055 obj->z_nodelete = obj->ref_nodel = true; 3056 } 3057 } 3058 3059 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3060 name); 3061 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3062 3063 if (!(lo_flags & RTLD_LO_EARLY)) { 3064 map_stacks_exec(lockstate); 3065 } 3066 3067 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3068 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3069 lockstate) == -1) { 3070 objlist_clear(&initlist); 3071 dlopen_cleanup(obj); 3072 if (lockstate == &mlockstate) 3073 lock_release(rtld_bind_lock, lockstate); 3074 return (NULL); 3075 } 3076 3077 if (!(lo_flags & RTLD_LO_EARLY)) { 3078 /* Call the init functions. */ 3079 objlist_call_init(&initlist, lockstate); 3080 } 3081 objlist_clear(&initlist); 3082 if (lockstate == &mlockstate) 3083 lock_release(rtld_bind_lock, lockstate); 3084 return obj; 3085 trace: 3086 trace_loaded_objects(obj); 3087 if (lockstate == &mlockstate) 3088 lock_release(rtld_bind_lock, lockstate); 3089 exit(0); 3090 } 3091 3092 static void * 3093 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3094 int flags) 3095 { 3096 DoneList donelist; 3097 const Obj_Entry *obj, *defobj; 3098 const Elf_Sym *def; 3099 SymLook req; 3100 RtldLockState lockstate; 3101 tls_index ti; 3102 int res; 3103 3104 def = NULL; 3105 defobj = NULL; 3106 symlook_init(&req, name); 3107 req.ventry = ve; 3108 req.flags = flags | SYMLOOK_IN_PLT; 3109 req.lockstate = &lockstate; 3110 3111 rlock_acquire(rtld_bind_lock, &lockstate); 3112 if (sigsetjmp(lockstate.env, 0) != 0) 3113 lock_upgrade(rtld_bind_lock, &lockstate); 3114 if (handle == NULL || handle == RTLD_NEXT || 3115 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3116 3117 if ((obj = obj_from_addr(retaddr)) == NULL) { 3118 _rtld_error("Cannot determine caller's shared object"); 3119 lock_release(rtld_bind_lock, &lockstate); 3120 return NULL; 3121 } 3122 if (handle == NULL) { /* Just the caller's shared object. */ 3123 res = symlook_obj(&req, obj); 3124 if (res == 0) { 3125 def = req.sym_out; 3126 defobj = req.defobj_out; 3127 } 3128 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3129 handle == RTLD_SELF) { /* ... caller included */ 3130 if (handle == RTLD_NEXT) 3131 obj = obj->next; 3132 for (; obj != NULL; obj = obj->next) { 3133 res = symlook_obj(&req, obj); 3134 if (res == 0) { 3135 if (def == NULL || 3136 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3137 def = req.sym_out; 3138 defobj = req.defobj_out; 3139 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3140 break; 3141 } 3142 } 3143 } 3144 /* 3145 * Search the dynamic linker itself, and possibly resolve the 3146 * symbol from there. This is how the application links to 3147 * dynamic linker services such as dlopen. 3148 */ 3149 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3150 res = symlook_obj(&req, &obj_rtld); 3151 if (res == 0) { 3152 def = req.sym_out; 3153 defobj = req.defobj_out; 3154 } 3155 } 3156 } else { 3157 assert(handle == RTLD_DEFAULT); 3158 res = symlook_default(&req, obj); 3159 if (res == 0) { 3160 defobj = req.defobj_out; 3161 def = req.sym_out; 3162 } 3163 } 3164 } else { 3165 if ((obj = dlcheck(handle)) == NULL) { 3166 lock_release(rtld_bind_lock, &lockstate); 3167 return NULL; 3168 } 3169 3170 donelist_init(&donelist); 3171 if (obj->mainprog) { 3172 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3173 res = symlook_global(&req, &donelist); 3174 if (res == 0) { 3175 def = req.sym_out; 3176 defobj = req.defobj_out; 3177 } 3178 /* 3179 * Search the dynamic linker itself, and possibly resolve the 3180 * symbol from there. This is how the application links to 3181 * dynamic linker services such as dlopen. 3182 */ 3183 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3184 res = symlook_obj(&req, &obj_rtld); 3185 if (res == 0) { 3186 def = req.sym_out; 3187 defobj = req.defobj_out; 3188 } 3189 } 3190 } 3191 else { 3192 /* Search the whole DAG rooted at the given object. */ 3193 res = symlook_list(&req, &obj->dagmembers, &donelist); 3194 if (res == 0) { 3195 def = req.sym_out; 3196 defobj = req.defobj_out; 3197 } 3198 } 3199 } 3200 3201 if (def != NULL) { 3202 lock_release(rtld_bind_lock, &lockstate); 3203 3204 /* 3205 * The value required by the caller is derived from the value 3206 * of the symbol. this is simply the relocated value of the 3207 * symbol. 3208 */ 3209 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3210 return (make_function_pointer(def, defobj)); 3211 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3212 return (rtld_resolve_ifunc(defobj, def)); 3213 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3214 ti.ti_module = defobj->tlsindex; 3215 ti.ti_offset = def->st_value; 3216 return (__tls_get_addr(&ti)); 3217 } else 3218 return (defobj->relocbase + def->st_value); 3219 } 3220 3221 _rtld_error("Undefined symbol \"%s\"", name); 3222 lock_release(rtld_bind_lock, &lockstate); 3223 return NULL; 3224 } 3225 3226 void * 3227 dlsym(void *handle, const char *name) 3228 { 3229 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3230 SYMLOOK_DLSYM); 3231 } 3232 3233 dlfunc_t 3234 dlfunc(void *handle, const char *name) 3235 { 3236 union { 3237 void *d; 3238 dlfunc_t f; 3239 } rv; 3240 3241 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3242 SYMLOOK_DLSYM); 3243 return (rv.f); 3244 } 3245 3246 void * 3247 dlvsym(void *handle, const char *name, const char *version) 3248 { 3249 Ver_Entry ventry; 3250 3251 ventry.name = version; 3252 ventry.file = NULL; 3253 ventry.hash = elf_hash(version); 3254 ventry.flags= 0; 3255 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3256 SYMLOOK_DLSYM); 3257 } 3258 3259 int 3260 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3261 { 3262 const Obj_Entry *obj; 3263 RtldLockState lockstate; 3264 3265 rlock_acquire(rtld_bind_lock, &lockstate); 3266 obj = obj_from_addr(addr); 3267 if (obj == NULL) { 3268 _rtld_error("No shared object contains address"); 3269 lock_release(rtld_bind_lock, &lockstate); 3270 return (0); 3271 } 3272 rtld_fill_dl_phdr_info(obj, phdr_info); 3273 lock_release(rtld_bind_lock, &lockstate); 3274 return (1); 3275 } 3276 3277 int 3278 dladdr(const void *addr, Dl_info *info) 3279 { 3280 const Obj_Entry *obj; 3281 const Elf_Sym *def; 3282 void *symbol_addr; 3283 unsigned long symoffset; 3284 RtldLockState lockstate; 3285 3286 rlock_acquire(rtld_bind_lock, &lockstate); 3287 obj = obj_from_addr(addr); 3288 if (obj == NULL) { 3289 _rtld_error("No shared object contains address"); 3290 lock_release(rtld_bind_lock, &lockstate); 3291 return 0; 3292 } 3293 info->dli_fname = obj->path; 3294 info->dli_fbase = obj->mapbase; 3295 info->dli_saddr = (void *)0; 3296 info->dli_sname = NULL; 3297 3298 /* 3299 * Walk the symbol list looking for the symbol whose address is 3300 * closest to the address sent in. 3301 */ 3302 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3303 def = obj->symtab + symoffset; 3304 3305 /* 3306 * For skip the symbol if st_shndx is either SHN_UNDEF or 3307 * SHN_COMMON. 3308 */ 3309 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3310 continue; 3311 3312 /* 3313 * If the symbol is greater than the specified address, or if it 3314 * is further away from addr than the current nearest symbol, 3315 * then reject it. 3316 */ 3317 symbol_addr = obj->relocbase + def->st_value; 3318 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3319 continue; 3320 3321 /* Update our idea of the nearest symbol. */ 3322 info->dli_sname = obj->strtab + def->st_name; 3323 info->dli_saddr = symbol_addr; 3324 3325 /* Exact match? */ 3326 if (info->dli_saddr == addr) 3327 break; 3328 } 3329 lock_release(rtld_bind_lock, &lockstate); 3330 return 1; 3331 } 3332 3333 int 3334 dlinfo(void *handle, int request, void *p) 3335 { 3336 const Obj_Entry *obj; 3337 RtldLockState lockstate; 3338 int error; 3339 3340 rlock_acquire(rtld_bind_lock, &lockstate); 3341 3342 if (handle == NULL || handle == RTLD_SELF) { 3343 void *retaddr; 3344 3345 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3346 if ((obj = obj_from_addr(retaddr)) == NULL) 3347 _rtld_error("Cannot determine caller's shared object"); 3348 } else 3349 obj = dlcheck(handle); 3350 3351 if (obj == NULL) { 3352 lock_release(rtld_bind_lock, &lockstate); 3353 return (-1); 3354 } 3355 3356 error = 0; 3357 switch (request) { 3358 case RTLD_DI_LINKMAP: 3359 *((struct link_map const **)p) = &obj->linkmap; 3360 break; 3361 case RTLD_DI_ORIGIN: 3362 error = rtld_dirname(obj->path, p); 3363 break; 3364 3365 case RTLD_DI_SERINFOSIZE: 3366 case RTLD_DI_SERINFO: 3367 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3368 break; 3369 3370 default: 3371 _rtld_error("Invalid request %d passed to dlinfo()", request); 3372 error = -1; 3373 } 3374 3375 lock_release(rtld_bind_lock, &lockstate); 3376 3377 return (error); 3378 } 3379 3380 static void 3381 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3382 { 3383 3384 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3385 phdr_info->dlpi_name = obj->path; 3386 phdr_info->dlpi_phdr = obj->phdr; 3387 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3388 phdr_info->dlpi_tls_modid = obj->tlsindex; 3389 phdr_info->dlpi_tls_data = obj->tlsinit; 3390 phdr_info->dlpi_adds = obj_loads; 3391 phdr_info->dlpi_subs = obj_loads - obj_count; 3392 } 3393 3394 int 3395 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3396 { 3397 struct dl_phdr_info phdr_info; 3398 const Obj_Entry *obj; 3399 RtldLockState bind_lockstate, phdr_lockstate; 3400 int error; 3401 3402 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3403 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3404 3405 error = 0; 3406 3407 for (obj = obj_list; obj != NULL; obj = obj->next) { 3408 rtld_fill_dl_phdr_info(obj, &phdr_info); 3409 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3410 break; 3411 3412 } 3413 if (error == 0) { 3414 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3415 error = callback(&phdr_info, sizeof(phdr_info), param); 3416 } 3417 3418 lock_release(rtld_bind_lock, &bind_lockstate); 3419 lock_release(rtld_phdr_lock, &phdr_lockstate); 3420 3421 return (error); 3422 } 3423 3424 static void * 3425 fill_search_info(const char *dir, size_t dirlen, void *param) 3426 { 3427 struct fill_search_info_args *arg; 3428 3429 arg = param; 3430 3431 if (arg->request == RTLD_DI_SERINFOSIZE) { 3432 arg->serinfo->dls_cnt ++; 3433 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3434 } else { 3435 struct dl_serpath *s_entry; 3436 3437 s_entry = arg->serpath; 3438 s_entry->dls_name = arg->strspace; 3439 s_entry->dls_flags = arg->flags; 3440 3441 strncpy(arg->strspace, dir, dirlen); 3442 arg->strspace[dirlen] = '\0'; 3443 3444 arg->strspace += dirlen + 1; 3445 arg->serpath++; 3446 } 3447 3448 return (NULL); 3449 } 3450 3451 static int 3452 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3453 { 3454 struct dl_serinfo _info; 3455 struct fill_search_info_args args; 3456 3457 args.request = RTLD_DI_SERINFOSIZE; 3458 args.serinfo = &_info; 3459 3460 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3461 _info.dls_cnt = 0; 3462 3463 path_enumerate(obj->rpath, fill_search_info, &args); 3464 path_enumerate(ld_library_path, fill_search_info, &args); 3465 path_enumerate(obj->runpath, fill_search_info, &args); 3466 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3467 if (!obj->z_nodeflib) 3468 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3469 3470 3471 if (request == RTLD_DI_SERINFOSIZE) { 3472 info->dls_size = _info.dls_size; 3473 info->dls_cnt = _info.dls_cnt; 3474 return (0); 3475 } 3476 3477 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3478 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3479 return (-1); 3480 } 3481 3482 args.request = RTLD_DI_SERINFO; 3483 args.serinfo = info; 3484 args.serpath = &info->dls_serpath[0]; 3485 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3486 3487 args.flags = LA_SER_RUNPATH; 3488 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3489 return (-1); 3490 3491 args.flags = LA_SER_LIBPATH; 3492 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3493 return (-1); 3494 3495 args.flags = LA_SER_RUNPATH; 3496 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3497 return (-1); 3498 3499 args.flags = LA_SER_CONFIG; 3500 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3501 != NULL) 3502 return (-1); 3503 3504 args.flags = LA_SER_DEFAULT; 3505 if (!obj->z_nodeflib && 3506 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3507 return (-1); 3508 return (0); 3509 } 3510 3511 static int 3512 rtld_dirname(const char *path, char *bname) 3513 { 3514 const char *endp; 3515 3516 /* Empty or NULL string gets treated as "." */ 3517 if (path == NULL || *path == '\0') { 3518 bname[0] = '.'; 3519 bname[1] = '\0'; 3520 return (0); 3521 } 3522 3523 /* Strip trailing slashes */ 3524 endp = path + strlen(path) - 1; 3525 while (endp > path && *endp == '/') 3526 endp--; 3527 3528 /* Find the start of the dir */ 3529 while (endp > path && *endp != '/') 3530 endp--; 3531 3532 /* Either the dir is "/" or there are no slashes */ 3533 if (endp == path) { 3534 bname[0] = *endp == '/' ? '/' : '.'; 3535 bname[1] = '\0'; 3536 return (0); 3537 } else { 3538 do { 3539 endp--; 3540 } while (endp > path && *endp == '/'); 3541 } 3542 3543 if (endp - path + 2 > PATH_MAX) 3544 { 3545 _rtld_error("Filename is too long: %s", path); 3546 return(-1); 3547 } 3548 3549 strncpy(bname, path, endp - path + 1); 3550 bname[endp - path + 1] = '\0'; 3551 return (0); 3552 } 3553 3554 static int 3555 rtld_dirname_abs(const char *path, char *base) 3556 { 3557 char base_rel[PATH_MAX]; 3558 3559 if (rtld_dirname(path, base) == -1) 3560 return (-1); 3561 if (base[0] == '/') 3562 return (0); 3563 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3564 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3565 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3566 return (-1); 3567 strcpy(base, base_rel); 3568 return (0); 3569 } 3570 3571 static void 3572 linkmap_add(Obj_Entry *obj) 3573 { 3574 struct link_map *l = &obj->linkmap; 3575 struct link_map *prev; 3576 3577 obj->linkmap.l_name = obj->path; 3578 obj->linkmap.l_addr = obj->mapbase; 3579 obj->linkmap.l_ld = obj->dynamic; 3580 #ifdef __mips__ 3581 /* GDB needs load offset on MIPS to use the symbols */ 3582 obj->linkmap.l_offs = obj->relocbase; 3583 #endif 3584 3585 if (r_debug.r_map == NULL) { 3586 r_debug.r_map = l; 3587 return; 3588 } 3589 3590 /* 3591 * Scan to the end of the list, but not past the entry for the 3592 * dynamic linker, which we want to keep at the very end. 3593 */ 3594 for (prev = r_debug.r_map; 3595 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3596 prev = prev->l_next) 3597 ; 3598 3599 /* Link in the new entry. */ 3600 l->l_prev = prev; 3601 l->l_next = prev->l_next; 3602 if (l->l_next != NULL) 3603 l->l_next->l_prev = l; 3604 prev->l_next = l; 3605 } 3606 3607 static void 3608 linkmap_delete(Obj_Entry *obj) 3609 { 3610 struct link_map *l = &obj->linkmap; 3611 3612 if (l->l_prev == NULL) { 3613 if ((r_debug.r_map = l->l_next) != NULL) 3614 l->l_next->l_prev = NULL; 3615 return; 3616 } 3617 3618 if ((l->l_prev->l_next = l->l_next) != NULL) 3619 l->l_next->l_prev = l->l_prev; 3620 } 3621 3622 /* 3623 * Function for the debugger to set a breakpoint on to gain control. 3624 * 3625 * The two parameters allow the debugger to easily find and determine 3626 * what the runtime loader is doing and to whom it is doing it. 3627 * 3628 * When the loadhook trap is hit (r_debug_state, set at program 3629 * initialization), the arguments can be found on the stack: 3630 * 3631 * +8 struct link_map *m 3632 * +4 struct r_debug *rd 3633 * +0 RetAddr 3634 */ 3635 void 3636 r_debug_state(struct r_debug* rd, struct link_map *m) 3637 { 3638 /* 3639 * The following is a hack to force the compiler to emit calls to 3640 * this function, even when optimizing. If the function is empty, 3641 * the compiler is not obliged to emit any code for calls to it, 3642 * even when marked __noinline. However, gdb depends on those 3643 * calls being made. 3644 */ 3645 __compiler_membar(); 3646 } 3647 3648 /* 3649 * A function called after init routines have completed. This can be used to 3650 * break before a program's entry routine is called, and can be used when 3651 * main is not available in the symbol table. 3652 */ 3653 void 3654 _r_debug_postinit(struct link_map *m) 3655 { 3656 3657 /* See r_debug_state(). */ 3658 __compiler_membar(); 3659 } 3660 3661 /* 3662 * Get address of the pointer variable in the main program. 3663 * Prefer non-weak symbol over the weak one. 3664 */ 3665 static const void ** 3666 get_program_var_addr(const char *name, RtldLockState *lockstate) 3667 { 3668 SymLook req; 3669 DoneList donelist; 3670 3671 symlook_init(&req, name); 3672 req.lockstate = lockstate; 3673 donelist_init(&donelist); 3674 if (symlook_global(&req, &donelist) != 0) 3675 return (NULL); 3676 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3677 return ((const void **)make_function_pointer(req.sym_out, 3678 req.defobj_out)); 3679 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3680 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3681 else 3682 return ((const void **)(req.defobj_out->relocbase + 3683 req.sym_out->st_value)); 3684 } 3685 3686 /* 3687 * Set a pointer variable in the main program to the given value. This 3688 * is used to set key variables such as "environ" before any of the 3689 * init functions are called. 3690 */ 3691 static void 3692 set_program_var(const char *name, const void *value) 3693 { 3694 const void **addr; 3695 3696 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3697 dbg("\"%s\": *%p <-- %p", name, addr, value); 3698 *addr = value; 3699 } 3700 } 3701 3702 /* 3703 * Search the global objects, including dependencies and main object, 3704 * for the given symbol. 3705 */ 3706 static int 3707 symlook_global(SymLook *req, DoneList *donelist) 3708 { 3709 SymLook req1; 3710 const Objlist_Entry *elm; 3711 int res; 3712 3713 symlook_init_from_req(&req1, req); 3714 3715 /* Search all objects loaded at program start up. */ 3716 if (req->defobj_out == NULL || 3717 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3718 res = symlook_list(&req1, &list_main, donelist); 3719 if (res == 0 && (req->defobj_out == NULL || 3720 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3721 req->sym_out = req1.sym_out; 3722 req->defobj_out = req1.defobj_out; 3723 assert(req->defobj_out != NULL); 3724 } 3725 } 3726 3727 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3728 STAILQ_FOREACH(elm, &list_global, link) { 3729 if (req->defobj_out != NULL && 3730 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3731 break; 3732 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3733 if (res == 0 && (req->defobj_out == NULL || 3734 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3735 req->sym_out = req1.sym_out; 3736 req->defobj_out = req1.defobj_out; 3737 assert(req->defobj_out != NULL); 3738 } 3739 } 3740 3741 return (req->sym_out != NULL ? 0 : ESRCH); 3742 } 3743 3744 /* 3745 * Given a symbol name in a referencing object, find the corresponding 3746 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3747 * no definition was found. Returns a pointer to the Obj_Entry of the 3748 * defining object via the reference parameter DEFOBJ_OUT. 3749 */ 3750 static int 3751 symlook_default(SymLook *req, const Obj_Entry *refobj) 3752 { 3753 DoneList donelist; 3754 const Objlist_Entry *elm; 3755 SymLook req1; 3756 int res; 3757 3758 donelist_init(&donelist); 3759 symlook_init_from_req(&req1, req); 3760 3761 /* Look first in the referencing object if linked symbolically. */ 3762 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3763 res = symlook_obj(&req1, refobj); 3764 if (res == 0) { 3765 req->sym_out = req1.sym_out; 3766 req->defobj_out = req1.defobj_out; 3767 assert(req->defobj_out != NULL); 3768 } 3769 } 3770 3771 symlook_global(req, &donelist); 3772 3773 /* Search all dlopened DAGs containing the referencing object. */ 3774 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3775 if (req->sym_out != NULL && 3776 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3777 break; 3778 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3779 if (res == 0 && (req->sym_out == NULL || 3780 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3781 req->sym_out = req1.sym_out; 3782 req->defobj_out = req1.defobj_out; 3783 assert(req->defobj_out != NULL); 3784 } 3785 } 3786 3787 /* 3788 * Search the dynamic linker itself, and possibly resolve the 3789 * symbol from there. This is how the application links to 3790 * dynamic linker services such as dlopen. 3791 */ 3792 if (req->sym_out == NULL || 3793 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3794 res = symlook_obj(&req1, &obj_rtld); 3795 if (res == 0) { 3796 req->sym_out = req1.sym_out; 3797 req->defobj_out = req1.defobj_out; 3798 assert(req->defobj_out != NULL); 3799 } 3800 } 3801 3802 return (req->sym_out != NULL ? 0 : ESRCH); 3803 } 3804 3805 static int 3806 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3807 { 3808 const Elf_Sym *def; 3809 const Obj_Entry *defobj; 3810 const Objlist_Entry *elm; 3811 SymLook req1; 3812 int res; 3813 3814 def = NULL; 3815 defobj = NULL; 3816 STAILQ_FOREACH(elm, objlist, link) { 3817 if (donelist_check(dlp, elm->obj)) 3818 continue; 3819 symlook_init_from_req(&req1, req); 3820 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3821 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3822 def = req1.sym_out; 3823 defobj = req1.defobj_out; 3824 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3825 break; 3826 } 3827 } 3828 } 3829 if (def != NULL) { 3830 req->sym_out = def; 3831 req->defobj_out = defobj; 3832 return (0); 3833 } 3834 return (ESRCH); 3835 } 3836 3837 /* 3838 * Search the chain of DAGS cointed to by the given Needed_Entry 3839 * for a symbol of the given name. Each DAG is scanned completely 3840 * before advancing to the next one. Returns a pointer to the symbol, 3841 * or NULL if no definition was found. 3842 */ 3843 static int 3844 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3845 { 3846 const Elf_Sym *def; 3847 const Needed_Entry *n; 3848 const Obj_Entry *defobj; 3849 SymLook req1; 3850 int res; 3851 3852 def = NULL; 3853 defobj = NULL; 3854 symlook_init_from_req(&req1, req); 3855 for (n = needed; n != NULL; n = n->next) { 3856 if (n->obj == NULL || 3857 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3858 continue; 3859 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3860 def = req1.sym_out; 3861 defobj = req1.defobj_out; 3862 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3863 break; 3864 } 3865 } 3866 if (def != NULL) { 3867 req->sym_out = def; 3868 req->defobj_out = defobj; 3869 return (0); 3870 } 3871 return (ESRCH); 3872 } 3873 3874 /* 3875 * Search the symbol table of a single shared object for a symbol of 3876 * the given name and version, if requested. Returns a pointer to the 3877 * symbol, or NULL if no definition was found. If the object is 3878 * filter, return filtered symbol from filtee. 3879 * 3880 * The symbol's hash value is passed in for efficiency reasons; that 3881 * eliminates many recomputations of the hash value. 3882 */ 3883 int 3884 symlook_obj(SymLook *req, const Obj_Entry *obj) 3885 { 3886 DoneList donelist; 3887 SymLook req1; 3888 int flags, res, mres; 3889 3890 /* 3891 * If there is at least one valid hash at this point, we prefer to 3892 * use the faster GNU version if available. 3893 */ 3894 if (obj->valid_hash_gnu) 3895 mres = symlook_obj1_gnu(req, obj); 3896 else if (obj->valid_hash_sysv) 3897 mres = symlook_obj1_sysv(req, obj); 3898 else 3899 return (EINVAL); 3900 3901 if (mres == 0) { 3902 if (obj->needed_filtees != NULL) { 3903 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3904 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3905 donelist_init(&donelist); 3906 symlook_init_from_req(&req1, req); 3907 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3908 if (res == 0) { 3909 req->sym_out = req1.sym_out; 3910 req->defobj_out = req1.defobj_out; 3911 } 3912 return (res); 3913 } 3914 if (obj->needed_aux_filtees != NULL) { 3915 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3916 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3917 donelist_init(&donelist); 3918 symlook_init_from_req(&req1, req); 3919 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3920 if (res == 0) { 3921 req->sym_out = req1.sym_out; 3922 req->defobj_out = req1.defobj_out; 3923 return (res); 3924 } 3925 } 3926 } 3927 return (mres); 3928 } 3929 3930 /* Symbol match routine common to both hash functions */ 3931 static bool 3932 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3933 const unsigned long symnum) 3934 { 3935 Elf_Versym verndx; 3936 const Elf_Sym *symp; 3937 const char *strp; 3938 3939 symp = obj->symtab + symnum; 3940 strp = obj->strtab + symp->st_name; 3941 3942 switch (ELF_ST_TYPE(symp->st_info)) { 3943 case STT_FUNC: 3944 case STT_NOTYPE: 3945 case STT_OBJECT: 3946 case STT_COMMON: 3947 case STT_GNU_IFUNC: 3948 if (symp->st_value == 0) 3949 return (false); 3950 /* fallthrough */ 3951 case STT_TLS: 3952 if (symp->st_shndx != SHN_UNDEF) 3953 break; 3954 #ifndef __mips__ 3955 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3956 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3957 break; 3958 /* fallthrough */ 3959 #endif 3960 default: 3961 return (false); 3962 } 3963 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3964 return (false); 3965 3966 if (req->ventry == NULL) { 3967 if (obj->versyms != NULL) { 3968 verndx = VER_NDX(obj->versyms[symnum]); 3969 if (verndx > obj->vernum) { 3970 _rtld_error( 3971 "%s: symbol %s references wrong version %d", 3972 obj->path, obj->strtab + symnum, verndx); 3973 return (false); 3974 } 3975 /* 3976 * If we are not called from dlsym (i.e. this 3977 * is a normal relocation from unversioned 3978 * binary), accept the symbol immediately if 3979 * it happens to have first version after this 3980 * shared object became versioned. Otherwise, 3981 * if symbol is versioned and not hidden, 3982 * remember it. If it is the only symbol with 3983 * this name exported by the shared object, it 3984 * will be returned as a match by the calling 3985 * function. If symbol is global (verndx < 2) 3986 * accept it unconditionally. 3987 */ 3988 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3989 verndx == VER_NDX_GIVEN) { 3990 result->sym_out = symp; 3991 return (true); 3992 } 3993 else if (verndx >= VER_NDX_GIVEN) { 3994 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3995 == 0) { 3996 if (result->vsymp == NULL) 3997 result->vsymp = symp; 3998 result->vcount++; 3999 } 4000 return (false); 4001 } 4002 } 4003 result->sym_out = symp; 4004 return (true); 4005 } 4006 if (obj->versyms == NULL) { 4007 if (object_match_name(obj, req->ventry->name)) { 4008 _rtld_error("%s: object %s should provide version %s " 4009 "for symbol %s", obj_rtld.path, obj->path, 4010 req->ventry->name, obj->strtab + symnum); 4011 return (false); 4012 } 4013 } else { 4014 verndx = VER_NDX(obj->versyms[symnum]); 4015 if (verndx > obj->vernum) { 4016 _rtld_error("%s: symbol %s references wrong version %d", 4017 obj->path, obj->strtab + symnum, verndx); 4018 return (false); 4019 } 4020 if (obj->vertab[verndx].hash != req->ventry->hash || 4021 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4022 /* 4023 * Version does not match. Look if this is a 4024 * global symbol and if it is not hidden. If 4025 * global symbol (verndx < 2) is available, 4026 * use it. Do not return symbol if we are 4027 * called by dlvsym, because dlvsym looks for 4028 * a specific version and default one is not 4029 * what dlvsym wants. 4030 */ 4031 if ((req->flags & SYMLOOK_DLSYM) || 4032 (verndx >= VER_NDX_GIVEN) || 4033 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4034 return (false); 4035 } 4036 } 4037 result->sym_out = symp; 4038 return (true); 4039 } 4040 4041 /* 4042 * Search for symbol using SysV hash function. 4043 * obj->buckets is known not to be NULL at this point; the test for this was 4044 * performed with the obj->valid_hash_sysv assignment. 4045 */ 4046 static int 4047 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4048 { 4049 unsigned long symnum; 4050 Sym_Match_Result matchres; 4051 4052 matchres.sym_out = NULL; 4053 matchres.vsymp = NULL; 4054 matchres.vcount = 0; 4055 4056 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4057 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4058 if (symnum >= obj->nchains) 4059 return (ESRCH); /* Bad object */ 4060 4061 if (matched_symbol(req, obj, &matchres, symnum)) { 4062 req->sym_out = matchres.sym_out; 4063 req->defobj_out = obj; 4064 return (0); 4065 } 4066 } 4067 if (matchres.vcount == 1) { 4068 req->sym_out = matchres.vsymp; 4069 req->defobj_out = obj; 4070 return (0); 4071 } 4072 return (ESRCH); 4073 } 4074 4075 /* Search for symbol using GNU hash function */ 4076 static int 4077 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4078 { 4079 Elf_Addr bloom_word; 4080 const Elf32_Word *hashval; 4081 Elf32_Word bucket; 4082 Sym_Match_Result matchres; 4083 unsigned int h1, h2; 4084 unsigned long symnum; 4085 4086 matchres.sym_out = NULL; 4087 matchres.vsymp = NULL; 4088 matchres.vcount = 0; 4089 4090 /* Pick right bitmask word from Bloom filter array */ 4091 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4092 obj->maskwords_bm_gnu]; 4093 4094 /* Calculate modulus word size of gnu hash and its derivative */ 4095 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4096 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4097 4098 /* Filter out the "definitely not in set" queries */ 4099 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4100 return (ESRCH); 4101 4102 /* Locate hash chain and corresponding value element*/ 4103 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4104 if (bucket == 0) 4105 return (ESRCH); 4106 hashval = &obj->chain_zero_gnu[bucket]; 4107 do { 4108 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4109 symnum = hashval - obj->chain_zero_gnu; 4110 if (matched_symbol(req, obj, &matchres, symnum)) { 4111 req->sym_out = matchres.sym_out; 4112 req->defobj_out = obj; 4113 return (0); 4114 } 4115 } 4116 } while ((*hashval++ & 1) == 0); 4117 if (matchres.vcount == 1) { 4118 req->sym_out = matchres.vsymp; 4119 req->defobj_out = obj; 4120 return (0); 4121 } 4122 return (ESRCH); 4123 } 4124 4125 static void 4126 trace_loaded_objects(Obj_Entry *obj) 4127 { 4128 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4129 int c; 4130 4131 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 4132 main_local = ""; 4133 4134 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 4135 fmt1 = "\t%o => %p (%x)\n"; 4136 4137 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 4138 fmt2 = "\t%o (%x)\n"; 4139 4140 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 4141 4142 for (; obj; obj = obj->next) { 4143 Needed_Entry *needed; 4144 char *name, *path; 4145 bool is_lib; 4146 4147 if (list_containers && obj->needed != NULL) 4148 rtld_printf("%s:\n", obj->path); 4149 for (needed = obj->needed; needed; needed = needed->next) { 4150 if (needed->obj != NULL) { 4151 if (needed->obj->traced && !list_containers) 4152 continue; 4153 needed->obj->traced = true; 4154 path = needed->obj->path; 4155 } else 4156 path = "not found"; 4157 4158 name = (char *)obj->strtab + needed->name; 4159 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4160 4161 fmt = is_lib ? fmt1 : fmt2; 4162 while ((c = *fmt++) != '\0') { 4163 switch (c) { 4164 default: 4165 rtld_putchar(c); 4166 continue; 4167 case '\\': 4168 switch (c = *fmt) { 4169 case '\0': 4170 continue; 4171 case 'n': 4172 rtld_putchar('\n'); 4173 break; 4174 case 't': 4175 rtld_putchar('\t'); 4176 break; 4177 } 4178 break; 4179 case '%': 4180 switch (c = *fmt) { 4181 case '\0': 4182 continue; 4183 case '%': 4184 default: 4185 rtld_putchar(c); 4186 break; 4187 case 'A': 4188 rtld_putstr(main_local); 4189 break; 4190 case 'a': 4191 rtld_putstr(obj_main->path); 4192 break; 4193 case 'o': 4194 rtld_putstr(name); 4195 break; 4196 #if 0 4197 case 'm': 4198 rtld_printf("%d", sodp->sod_major); 4199 break; 4200 case 'n': 4201 rtld_printf("%d", sodp->sod_minor); 4202 break; 4203 #endif 4204 case 'p': 4205 rtld_putstr(path); 4206 break; 4207 case 'x': 4208 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4209 0); 4210 break; 4211 } 4212 break; 4213 } 4214 ++fmt; 4215 } 4216 } 4217 } 4218 } 4219 4220 /* 4221 * Unload a dlopened object and its dependencies from memory and from 4222 * our data structures. It is assumed that the DAG rooted in the 4223 * object has already been unreferenced, and that the object has a 4224 * reference count of 0. 4225 */ 4226 static void 4227 unload_object(Obj_Entry *root) 4228 { 4229 Obj_Entry *obj; 4230 Obj_Entry **linkp; 4231 4232 assert(root->refcount == 0); 4233 4234 /* 4235 * Pass over the DAG removing unreferenced objects from 4236 * appropriate lists. 4237 */ 4238 unlink_object(root); 4239 4240 /* Unmap all objects that are no longer referenced. */ 4241 linkp = &obj_list->next; 4242 while ((obj = *linkp) != NULL) { 4243 if (obj->refcount == 0) { 4244 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4245 obj->path); 4246 dbg("unloading \"%s\"", obj->path); 4247 unload_filtees(root); 4248 munmap(obj->mapbase, obj->mapsize); 4249 linkmap_delete(obj); 4250 *linkp = obj->next; 4251 obj_count--; 4252 obj_free(obj); 4253 } else 4254 linkp = &obj->next; 4255 } 4256 obj_tail = linkp; 4257 } 4258 4259 static void 4260 unlink_object(Obj_Entry *root) 4261 { 4262 Objlist_Entry *elm; 4263 4264 if (root->refcount == 0) { 4265 /* Remove the object from the RTLD_GLOBAL list. */ 4266 objlist_remove(&list_global, root); 4267 4268 /* Remove the object from all objects' DAG lists. */ 4269 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4270 objlist_remove(&elm->obj->dldags, root); 4271 if (elm->obj != root) 4272 unlink_object(elm->obj); 4273 } 4274 } 4275 } 4276 4277 static void 4278 ref_dag(Obj_Entry *root) 4279 { 4280 Objlist_Entry *elm; 4281 4282 assert(root->dag_inited); 4283 STAILQ_FOREACH(elm, &root->dagmembers, link) 4284 elm->obj->refcount++; 4285 } 4286 4287 static void 4288 unref_dag(Obj_Entry *root) 4289 { 4290 Objlist_Entry *elm; 4291 4292 assert(root->dag_inited); 4293 STAILQ_FOREACH(elm, &root->dagmembers, link) 4294 elm->obj->refcount--; 4295 } 4296 4297 /* 4298 * Common code for MD __tls_get_addr(). 4299 */ 4300 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4301 static void * 4302 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4303 { 4304 Elf_Addr *newdtv, *dtv; 4305 RtldLockState lockstate; 4306 int to_copy; 4307 4308 dtv = *dtvp; 4309 /* Check dtv generation in case new modules have arrived */ 4310 if (dtv[0] != tls_dtv_generation) { 4311 wlock_acquire(rtld_bind_lock, &lockstate); 4312 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4313 to_copy = dtv[1]; 4314 if (to_copy > tls_max_index) 4315 to_copy = tls_max_index; 4316 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4317 newdtv[0] = tls_dtv_generation; 4318 newdtv[1] = tls_max_index; 4319 free(dtv); 4320 lock_release(rtld_bind_lock, &lockstate); 4321 dtv = *dtvp = newdtv; 4322 } 4323 4324 /* Dynamically allocate module TLS if necessary */ 4325 if (dtv[index + 1] == 0) { 4326 /* Signal safe, wlock will block out signals. */ 4327 wlock_acquire(rtld_bind_lock, &lockstate); 4328 if (!dtv[index + 1]) 4329 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4330 lock_release(rtld_bind_lock, &lockstate); 4331 } 4332 return ((void *)(dtv[index + 1] + offset)); 4333 } 4334 4335 void * 4336 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4337 { 4338 Elf_Addr *dtv; 4339 4340 dtv = *dtvp; 4341 /* Check dtv generation in case new modules have arrived */ 4342 if (__predict_true(dtv[0] == tls_dtv_generation && 4343 dtv[index + 1] != 0)) 4344 return ((void *)(dtv[index + 1] + offset)); 4345 return (tls_get_addr_slow(dtvp, index, offset)); 4346 } 4347 4348 #if defined(__arm__) || defined(__mips__) || defined(__powerpc__) 4349 4350 /* 4351 * Allocate Static TLS using the Variant I method. 4352 */ 4353 void * 4354 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4355 { 4356 Obj_Entry *obj; 4357 char *tcb; 4358 Elf_Addr **tls; 4359 Elf_Addr *dtv; 4360 Elf_Addr addr; 4361 int i; 4362 4363 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4364 return (oldtcb); 4365 4366 assert(tcbsize >= TLS_TCB_SIZE); 4367 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4368 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4369 4370 if (oldtcb != NULL) { 4371 memcpy(tls, oldtcb, tls_static_space); 4372 free(oldtcb); 4373 4374 /* Adjust the DTV. */ 4375 dtv = tls[0]; 4376 for (i = 0; i < dtv[1]; i++) { 4377 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4378 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4379 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4380 } 4381 } 4382 } else { 4383 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4384 tls[0] = dtv; 4385 dtv[0] = tls_dtv_generation; 4386 dtv[1] = tls_max_index; 4387 4388 for (obj = objs; obj; obj = obj->next) { 4389 if (obj->tlsoffset > 0) { 4390 addr = (Elf_Addr)tls + obj->tlsoffset; 4391 if (obj->tlsinitsize > 0) 4392 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4393 if (obj->tlssize > obj->tlsinitsize) 4394 memset((void*) (addr + obj->tlsinitsize), 0, 4395 obj->tlssize - obj->tlsinitsize); 4396 dtv[obj->tlsindex + 1] = addr; 4397 } 4398 } 4399 } 4400 4401 return (tcb); 4402 } 4403 4404 void 4405 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4406 { 4407 Elf_Addr *dtv; 4408 Elf_Addr tlsstart, tlsend; 4409 int dtvsize, i; 4410 4411 assert(tcbsize >= TLS_TCB_SIZE); 4412 4413 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4414 tlsend = tlsstart + tls_static_space; 4415 4416 dtv = *(Elf_Addr **)tlsstart; 4417 dtvsize = dtv[1]; 4418 for (i = 0; i < dtvsize; i++) { 4419 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4420 free((void*)dtv[i+2]); 4421 } 4422 } 4423 free(dtv); 4424 free(tcb); 4425 } 4426 4427 #endif 4428 4429 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4430 4431 /* 4432 * Allocate Static TLS using the Variant II method. 4433 */ 4434 void * 4435 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4436 { 4437 Obj_Entry *obj; 4438 size_t size, ralign; 4439 char *tls; 4440 Elf_Addr *dtv, *olddtv; 4441 Elf_Addr segbase, oldsegbase, addr; 4442 int i; 4443 4444 ralign = tcbalign; 4445 if (tls_static_max_align > ralign) 4446 ralign = tls_static_max_align; 4447 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4448 4449 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4450 tls = malloc_aligned(size, ralign); 4451 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4452 4453 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4454 ((Elf_Addr*)segbase)[0] = segbase; 4455 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4456 4457 dtv[0] = tls_dtv_generation; 4458 dtv[1] = tls_max_index; 4459 4460 if (oldtls) { 4461 /* 4462 * Copy the static TLS block over whole. 4463 */ 4464 oldsegbase = (Elf_Addr) oldtls; 4465 memcpy((void *)(segbase - tls_static_space), 4466 (const void *)(oldsegbase - tls_static_space), 4467 tls_static_space); 4468 4469 /* 4470 * If any dynamic TLS blocks have been created tls_get_addr(), 4471 * move them over. 4472 */ 4473 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4474 for (i = 0; i < olddtv[1]; i++) { 4475 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4476 dtv[i+2] = olddtv[i+2]; 4477 olddtv[i+2] = 0; 4478 } 4479 } 4480 4481 /* 4482 * We assume that this block was the one we created with 4483 * allocate_initial_tls(). 4484 */ 4485 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4486 } else { 4487 for (obj = objs; obj; obj = obj->next) { 4488 if (obj->tlsoffset) { 4489 addr = segbase - obj->tlsoffset; 4490 memset((void*) (addr + obj->tlsinitsize), 4491 0, obj->tlssize - obj->tlsinitsize); 4492 if (obj->tlsinit) 4493 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4494 dtv[obj->tlsindex + 1] = addr; 4495 } 4496 } 4497 } 4498 4499 return (void*) segbase; 4500 } 4501 4502 void 4503 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4504 { 4505 Elf_Addr* dtv; 4506 size_t size, ralign; 4507 int dtvsize, i; 4508 Elf_Addr tlsstart, tlsend; 4509 4510 /* 4511 * Figure out the size of the initial TLS block so that we can 4512 * find stuff which ___tls_get_addr() allocated dynamically. 4513 */ 4514 ralign = tcbalign; 4515 if (tls_static_max_align > ralign) 4516 ralign = tls_static_max_align; 4517 size = round(tls_static_space, ralign); 4518 4519 dtv = ((Elf_Addr**)tls)[1]; 4520 dtvsize = dtv[1]; 4521 tlsend = (Elf_Addr) tls; 4522 tlsstart = tlsend - size; 4523 for (i = 0; i < dtvsize; i++) { 4524 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4525 free_aligned((void *)dtv[i + 2]); 4526 } 4527 } 4528 4529 free_aligned((void *)tlsstart); 4530 free((void*) dtv); 4531 } 4532 4533 #endif 4534 4535 /* 4536 * Allocate TLS block for module with given index. 4537 */ 4538 void * 4539 allocate_module_tls(int index) 4540 { 4541 Obj_Entry* obj; 4542 char* p; 4543 4544 for (obj = obj_list; obj; obj = obj->next) { 4545 if (obj->tlsindex == index) 4546 break; 4547 } 4548 if (!obj) { 4549 _rtld_error("Can't find module with TLS index %d", index); 4550 die(); 4551 } 4552 4553 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4554 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4555 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4556 4557 return p; 4558 } 4559 4560 bool 4561 allocate_tls_offset(Obj_Entry *obj) 4562 { 4563 size_t off; 4564 4565 if (obj->tls_done) 4566 return true; 4567 4568 if (obj->tlssize == 0) { 4569 obj->tls_done = true; 4570 return true; 4571 } 4572 4573 if (obj->tlsindex == 1) 4574 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4575 else 4576 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4577 obj->tlssize, obj->tlsalign); 4578 4579 /* 4580 * If we have already fixed the size of the static TLS block, we 4581 * must stay within that size. When allocating the static TLS, we 4582 * leave a small amount of space spare to be used for dynamically 4583 * loading modules which use static TLS. 4584 */ 4585 if (tls_static_space != 0) { 4586 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4587 return false; 4588 } else if (obj->tlsalign > tls_static_max_align) { 4589 tls_static_max_align = obj->tlsalign; 4590 } 4591 4592 tls_last_offset = obj->tlsoffset = off; 4593 tls_last_size = obj->tlssize; 4594 obj->tls_done = true; 4595 4596 return true; 4597 } 4598 4599 void 4600 free_tls_offset(Obj_Entry *obj) 4601 { 4602 4603 /* 4604 * If we were the last thing to allocate out of the static TLS 4605 * block, we give our space back to the 'allocator'. This is a 4606 * simplistic workaround to allow libGL.so.1 to be loaded and 4607 * unloaded multiple times. 4608 */ 4609 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4610 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4611 tls_last_offset -= obj->tlssize; 4612 tls_last_size = 0; 4613 } 4614 } 4615 4616 void * 4617 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4618 { 4619 void *ret; 4620 RtldLockState lockstate; 4621 4622 wlock_acquire(rtld_bind_lock, &lockstate); 4623 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4624 lock_release(rtld_bind_lock, &lockstate); 4625 return (ret); 4626 } 4627 4628 void 4629 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4630 { 4631 RtldLockState lockstate; 4632 4633 wlock_acquire(rtld_bind_lock, &lockstate); 4634 free_tls(tcb, tcbsize, tcbalign); 4635 lock_release(rtld_bind_lock, &lockstate); 4636 } 4637 4638 static void 4639 object_add_name(Obj_Entry *obj, const char *name) 4640 { 4641 Name_Entry *entry; 4642 size_t len; 4643 4644 len = strlen(name); 4645 entry = malloc(sizeof(Name_Entry) + len); 4646 4647 if (entry != NULL) { 4648 strcpy(entry->name, name); 4649 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4650 } 4651 } 4652 4653 static int 4654 object_match_name(const Obj_Entry *obj, const char *name) 4655 { 4656 Name_Entry *entry; 4657 4658 STAILQ_FOREACH(entry, &obj->names, link) { 4659 if (strcmp(name, entry->name) == 0) 4660 return (1); 4661 } 4662 return (0); 4663 } 4664 4665 static Obj_Entry * 4666 locate_dependency(const Obj_Entry *obj, const char *name) 4667 { 4668 const Objlist_Entry *entry; 4669 const Needed_Entry *needed; 4670 4671 STAILQ_FOREACH(entry, &list_main, link) { 4672 if (object_match_name(entry->obj, name)) 4673 return entry->obj; 4674 } 4675 4676 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4677 if (strcmp(obj->strtab + needed->name, name) == 0 || 4678 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4679 /* 4680 * If there is DT_NEEDED for the name we are looking for, 4681 * we are all set. Note that object might not be found if 4682 * dependency was not loaded yet, so the function can 4683 * return NULL here. This is expected and handled 4684 * properly by the caller. 4685 */ 4686 return (needed->obj); 4687 } 4688 } 4689 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4690 obj->path, name); 4691 die(); 4692 } 4693 4694 static int 4695 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4696 const Elf_Vernaux *vna) 4697 { 4698 const Elf_Verdef *vd; 4699 const char *vername; 4700 4701 vername = refobj->strtab + vna->vna_name; 4702 vd = depobj->verdef; 4703 if (vd == NULL) { 4704 _rtld_error("%s: version %s required by %s not defined", 4705 depobj->path, vername, refobj->path); 4706 return (-1); 4707 } 4708 for (;;) { 4709 if (vd->vd_version != VER_DEF_CURRENT) { 4710 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4711 depobj->path, vd->vd_version); 4712 return (-1); 4713 } 4714 if (vna->vna_hash == vd->vd_hash) { 4715 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4716 ((char *)vd + vd->vd_aux); 4717 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4718 return (0); 4719 } 4720 if (vd->vd_next == 0) 4721 break; 4722 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4723 } 4724 if (vna->vna_flags & VER_FLG_WEAK) 4725 return (0); 4726 _rtld_error("%s: version %s required by %s not found", 4727 depobj->path, vername, refobj->path); 4728 return (-1); 4729 } 4730 4731 static int 4732 rtld_verify_object_versions(Obj_Entry *obj) 4733 { 4734 const Elf_Verneed *vn; 4735 const Elf_Verdef *vd; 4736 const Elf_Verdaux *vda; 4737 const Elf_Vernaux *vna; 4738 const Obj_Entry *depobj; 4739 int maxvernum, vernum; 4740 4741 if (obj->ver_checked) 4742 return (0); 4743 obj->ver_checked = true; 4744 4745 maxvernum = 0; 4746 /* 4747 * Walk over defined and required version records and figure out 4748 * max index used by any of them. Do very basic sanity checking 4749 * while there. 4750 */ 4751 vn = obj->verneed; 4752 while (vn != NULL) { 4753 if (vn->vn_version != VER_NEED_CURRENT) { 4754 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4755 obj->path, vn->vn_version); 4756 return (-1); 4757 } 4758 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4759 for (;;) { 4760 vernum = VER_NEED_IDX(vna->vna_other); 4761 if (vernum > maxvernum) 4762 maxvernum = vernum; 4763 if (vna->vna_next == 0) 4764 break; 4765 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4766 } 4767 if (vn->vn_next == 0) 4768 break; 4769 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4770 } 4771 4772 vd = obj->verdef; 4773 while (vd != NULL) { 4774 if (vd->vd_version != VER_DEF_CURRENT) { 4775 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4776 obj->path, vd->vd_version); 4777 return (-1); 4778 } 4779 vernum = VER_DEF_IDX(vd->vd_ndx); 4780 if (vernum > maxvernum) 4781 maxvernum = vernum; 4782 if (vd->vd_next == 0) 4783 break; 4784 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4785 } 4786 4787 if (maxvernum == 0) 4788 return (0); 4789 4790 /* 4791 * Store version information in array indexable by version index. 4792 * Verify that object version requirements are satisfied along the 4793 * way. 4794 */ 4795 obj->vernum = maxvernum + 1; 4796 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4797 4798 vd = obj->verdef; 4799 while (vd != NULL) { 4800 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4801 vernum = VER_DEF_IDX(vd->vd_ndx); 4802 assert(vernum <= maxvernum); 4803 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4804 obj->vertab[vernum].hash = vd->vd_hash; 4805 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4806 obj->vertab[vernum].file = NULL; 4807 obj->vertab[vernum].flags = 0; 4808 } 4809 if (vd->vd_next == 0) 4810 break; 4811 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4812 } 4813 4814 vn = obj->verneed; 4815 while (vn != NULL) { 4816 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4817 if (depobj == NULL) 4818 return (-1); 4819 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4820 for (;;) { 4821 if (check_object_provided_version(obj, depobj, vna)) 4822 return (-1); 4823 vernum = VER_NEED_IDX(vna->vna_other); 4824 assert(vernum <= maxvernum); 4825 obj->vertab[vernum].hash = vna->vna_hash; 4826 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4827 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4828 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4829 VER_INFO_HIDDEN : 0; 4830 if (vna->vna_next == 0) 4831 break; 4832 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4833 } 4834 if (vn->vn_next == 0) 4835 break; 4836 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4837 } 4838 return 0; 4839 } 4840 4841 static int 4842 rtld_verify_versions(const Objlist *objlist) 4843 { 4844 Objlist_Entry *entry; 4845 int rc; 4846 4847 rc = 0; 4848 STAILQ_FOREACH(entry, objlist, link) { 4849 /* 4850 * Skip dummy objects or objects that have their version requirements 4851 * already checked. 4852 */ 4853 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4854 continue; 4855 if (rtld_verify_object_versions(entry->obj) == -1) { 4856 rc = -1; 4857 if (ld_tracing == NULL) 4858 break; 4859 } 4860 } 4861 if (rc == 0 || ld_tracing != NULL) 4862 rc = rtld_verify_object_versions(&obj_rtld); 4863 return rc; 4864 } 4865 4866 const Ver_Entry * 4867 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4868 { 4869 Elf_Versym vernum; 4870 4871 if (obj->vertab) { 4872 vernum = VER_NDX(obj->versyms[symnum]); 4873 if (vernum >= obj->vernum) { 4874 _rtld_error("%s: symbol %s has wrong verneed value %d", 4875 obj->path, obj->strtab + symnum, vernum); 4876 } else if (obj->vertab[vernum].hash != 0) { 4877 return &obj->vertab[vernum]; 4878 } 4879 } 4880 return NULL; 4881 } 4882 4883 int 4884 _rtld_get_stack_prot(void) 4885 { 4886 4887 return (stack_prot); 4888 } 4889 4890 int 4891 _rtld_is_dlopened(void *arg) 4892 { 4893 Obj_Entry *obj; 4894 RtldLockState lockstate; 4895 int res; 4896 4897 rlock_acquire(rtld_bind_lock, &lockstate); 4898 obj = dlcheck(arg); 4899 if (obj == NULL) 4900 obj = obj_from_addr(arg); 4901 if (obj == NULL) { 4902 _rtld_error("No shared object contains address"); 4903 lock_release(rtld_bind_lock, &lockstate); 4904 return (-1); 4905 } 4906 res = obj->dlopened ? 1 : 0; 4907 lock_release(rtld_bind_lock, &lockstate); 4908 return (res); 4909 } 4910 4911 static void 4912 map_stacks_exec(RtldLockState *lockstate) 4913 { 4914 void (*thr_map_stacks_exec)(void); 4915 4916 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4917 return; 4918 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4919 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4920 if (thr_map_stacks_exec != NULL) { 4921 stack_prot |= PROT_EXEC; 4922 thr_map_stacks_exec(); 4923 } 4924 } 4925 4926 void 4927 symlook_init(SymLook *dst, const char *name) 4928 { 4929 4930 bzero(dst, sizeof(*dst)); 4931 dst->name = name; 4932 dst->hash = elf_hash(name); 4933 dst->hash_gnu = gnu_hash(name); 4934 } 4935 4936 static void 4937 symlook_init_from_req(SymLook *dst, const SymLook *src) 4938 { 4939 4940 dst->name = src->name; 4941 dst->hash = src->hash; 4942 dst->hash_gnu = src->hash_gnu; 4943 dst->ventry = src->ventry; 4944 dst->flags = src->flags; 4945 dst->defobj_out = NULL; 4946 dst->sym_out = NULL; 4947 dst->lockstate = src->lockstate; 4948 } 4949 4950 4951 /* 4952 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 4953 */ 4954 static int 4955 parse_libdir(const char *str) 4956 { 4957 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 4958 const char *orig; 4959 int fd; 4960 char c; 4961 4962 orig = str; 4963 fd = 0; 4964 for (c = *str; c != '\0'; c = *++str) { 4965 if (c < '0' || c > '9') 4966 return (-1); 4967 4968 fd *= RADIX; 4969 fd += c - '0'; 4970 } 4971 4972 /* Make sure we actually parsed something. */ 4973 if (str == orig) { 4974 _rtld_error("failed to parse directory FD from '%s'", str); 4975 return (-1); 4976 } 4977 return (fd); 4978 } 4979 4980 /* 4981 * Overrides for libc_pic-provided functions. 4982 */ 4983 4984 int 4985 __getosreldate(void) 4986 { 4987 size_t len; 4988 int oid[2]; 4989 int error, osrel; 4990 4991 if (osreldate != 0) 4992 return (osreldate); 4993 4994 oid[0] = CTL_KERN; 4995 oid[1] = KERN_OSRELDATE; 4996 osrel = 0; 4997 len = sizeof(osrel); 4998 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4999 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5000 osreldate = osrel; 5001 return (osreldate); 5002 } 5003 5004 void 5005 exit(int status) 5006 { 5007 5008 _exit(status); 5009 } 5010 5011 void (*__cleanup)(void); 5012 int __isthreaded = 0; 5013 int _thread_autoinit_dummy_decl = 1; 5014 5015 /* 5016 * No unresolved symbols for rtld. 5017 */ 5018 void 5019 __pthread_cxa_finalize(struct dl_phdr_info *a) 5020 { 5021 } 5022 5023 void 5024 __stack_chk_fail(void) 5025 { 5026 5027 _rtld_error("stack overflow detected; terminated"); 5028 die(); 5029 } 5030 __weak_reference(__stack_chk_fail, __stack_chk_fail_local); 5031 5032 void 5033 __chk_fail(void) 5034 { 5035 5036 _rtld_error("buffer overflow detected; terminated"); 5037 die(); 5038 } 5039 5040 const char * 5041 rtld_strerror(int errnum) 5042 { 5043 5044 if (errnum < 0 || errnum >= sys_nerr) 5045 return ("Unknown error"); 5046 return (sys_errlist[errnum]); 5047 } 5048