1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <[email protected]>. 6 * Copyright 2009-2013 Konstantin Belousov <[email protected]>. 7 * Copyright 2012 John Marino <[email protected]>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <[email protected]>. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/uio.h> 50 #include <sys/utsname.h> 51 #include <sys/ktrace.h> 52 53 #include <dlfcn.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "debug.h" 64 #include "rtld.h" 65 #include "libmap.h" 66 #include "paths.h" 67 #include "rtld_tls.h" 68 #include "rtld_printf.h" 69 #include "rtld_utrace.h" 70 #include "notes.h" 71 72 /* Types. */ 73 typedef void (*func_ptr_type)(); 74 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 75 76 /* 77 * Function declarations. 78 */ 79 static const char *basename(const char *); 80 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 81 const Elf_Dyn **, const Elf_Dyn **); 82 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 83 const Elf_Dyn *); 84 static void digest_dynamic(Obj_Entry *, int); 85 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 86 static Obj_Entry *dlcheck(void *); 87 static int dlclose_locked(void *, RtldLockState *); 88 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 89 int lo_flags, int mode, RtldLockState *lockstate); 90 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 91 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 92 static bool donelist_check(DoneList *, const Obj_Entry *); 93 static void errmsg_restore(char *); 94 static char *errmsg_save(void); 95 static void *fill_search_info(const char *, size_t, void *); 96 static char *find_library(const char *, const Obj_Entry *, int *); 97 static const char *gethints(bool); 98 static void hold_object(Obj_Entry *); 99 static void unhold_object(Obj_Entry *); 100 static void init_dag(Obj_Entry *); 101 static void init_marker(Obj_Entry *); 102 static void init_pagesizes(Elf_Auxinfo **aux_info); 103 static void init_rtld(caddr_t, Elf_Auxinfo **); 104 static void initlist_add_neededs(Needed_Entry *, Objlist *); 105 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 106 static void linkmap_add(Obj_Entry *); 107 static void linkmap_delete(Obj_Entry *); 108 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 109 static void unload_filtees(Obj_Entry *, RtldLockState *); 110 static int load_needed_objects(Obj_Entry *, int); 111 static int load_preload_objects(void); 112 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 113 static void map_stacks_exec(RtldLockState *); 114 static int obj_enforce_relro(Obj_Entry *); 115 static Obj_Entry *obj_from_addr(const void *); 116 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 117 static void objlist_call_init(Objlist *, RtldLockState *); 118 static void objlist_clear(Objlist *); 119 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 120 static void objlist_init(Objlist *); 121 static void objlist_push_head(Objlist *, Obj_Entry *); 122 static void objlist_push_tail(Objlist *, Obj_Entry *); 123 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 124 static void objlist_remove(Objlist *, Obj_Entry *); 125 static int open_binary_fd(const char *argv0, bool search_in_path); 126 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp); 127 static int parse_integer(const char *); 128 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 129 static void print_usage(const char *argv0); 130 static void release_object(Obj_Entry *); 131 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 132 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 133 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 134 int flags, RtldLockState *lockstate); 135 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 136 RtldLockState *); 137 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 138 int flags, RtldLockState *lockstate); 139 static int rtld_dirname(const char *, char *); 140 static int rtld_dirname_abs(const char *, char *); 141 static void *rtld_dlopen(const char *name, int fd, int mode); 142 static void rtld_exit(void); 143 static char *search_library_path(const char *, const char *, const char *, 144 int *); 145 static char *search_library_pathfds(const char *, const char *, int *); 146 static const void **get_program_var_addr(const char *, RtldLockState *); 147 static void set_program_var(const char *, const void *); 148 static int symlook_default(SymLook *, const Obj_Entry *refobj); 149 static int symlook_global(SymLook *, DoneList *); 150 static void symlook_init_from_req(SymLook *, const SymLook *); 151 static int symlook_list(SymLook *, const Objlist *, DoneList *); 152 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 153 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 154 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 155 static void trace_loaded_objects(Obj_Entry *); 156 static void unlink_object(Obj_Entry *); 157 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 158 static void unref_dag(Obj_Entry *); 159 static void ref_dag(Obj_Entry *); 160 static char *origin_subst_one(Obj_Entry *, char *, const char *, 161 const char *, bool); 162 static char *origin_subst(Obj_Entry *, char *); 163 static bool obj_resolve_origin(Obj_Entry *obj); 164 static void preinit_main(void); 165 static int rtld_verify_versions(const Objlist *); 166 static int rtld_verify_object_versions(Obj_Entry *); 167 static void object_add_name(Obj_Entry *, const char *); 168 static int object_match_name(const Obj_Entry *, const char *); 169 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 170 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 171 struct dl_phdr_info *phdr_info); 172 static uint32_t gnu_hash(const char *); 173 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 174 const unsigned long); 175 176 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 177 void _r_debug_postinit(struct link_map *) __noinline __exported; 178 179 int __sys_openat(int, const char *, int, ...); 180 181 /* 182 * Data declarations. 183 */ 184 static char *error_message; /* Message for dlerror(), or NULL */ 185 struct r_debug r_debug __exported; /* for GDB; */ 186 static bool libmap_disable; /* Disable libmap */ 187 static bool ld_loadfltr; /* Immediate filters processing */ 188 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 189 static bool trust; /* False for setuid and setgid programs */ 190 static bool dangerous_ld_env; /* True if environment variables have been 191 used to affect the libraries loaded */ 192 bool ld_bind_not; /* Disable PLT update */ 193 static char *ld_bind_now; /* Environment variable for immediate binding */ 194 static char *ld_debug; /* Environment variable for debugging */ 195 static char *ld_library_path; /* Environment variable for search path */ 196 static char *ld_library_dirs; /* Environment variable for library descriptors */ 197 static char *ld_preload; /* Environment variable for libraries to 198 load first */ 199 static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 200 static char *ld_tracing; /* Called from ldd to print libs */ 201 static char *ld_utrace; /* Use utrace() to log events. */ 202 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 203 static Obj_Entry *obj_main; /* The main program shared object */ 204 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 205 static unsigned int obj_count; /* Number of objects in obj_list */ 206 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 207 208 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 209 STAILQ_HEAD_INITIALIZER(list_global); 210 static Objlist list_main = /* Objects loaded at program startup */ 211 STAILQ_HEAD_INITIALIZER(list_main); 212 static Objlist list_fini = /* Objects needing fini() calls */ 213 STAILQ_HEAD_INITIALIZER(list_fini); 214 215 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 216 217 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 218 219 extern Elf_Dyn _DYNAMIC; 220 #pragma weak _DYNAMIC 221 222 int dlclose(void *) __exported; 223 char *dlerror(void) __exported; 224 void *dlopen(const char *, int) __exported; 225 void *fdlopen(int, int) __exported; 226 void *dlsym(void *, const char *) __exported; 227 dlfunc_t dlfunc(void *, const char *) __exported; 228 void *dlvsym(void *, const char *, const char *) __exported; 229 int dladdr(const void *, Dl_info *) __exported; 230 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 231 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 232 int dlinfo(void *, int , void *) __exported; 233 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 234 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 235 int _rtld_get_stack_prot(void) __exported; 236 int _rtld_is_dlopened(void *) __exported; 237 void _rtld_error(const char *, ...) __exported; 238 239 int npagesizes, osreldate; 240 size_t *pagesizes; 241 242 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 243 static int max_stack_flags; 244 245 /* 246 * Global declarations normally provided by crt1. The dynamic linker is 247 * not built with crt1, so we have to provide them ourselves. 248 */ 249 char *__progname; 250 char **environ; 251 252 /* 253 * Used to pass argc, argv to init functions. 254 */ 255 int main_argc; 256 char **main_argv; 257 258 /* 259 * Globals to control TLS allocation. 260 */ 261 size_t tls_last_offset; /* Static TLS offset of last module */ 262 size_t tls_last_size; /* Static TLS size of last module */ 263 size_t tls_static_space; /* Static TLS space allocated */ 264 size_t tls_static_max_align; 265 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 266 int tls_max_index = 1; /* Largest module index allocated */ 267 268 bool ld_library_path_rpath = false; 269 270 /* 271 * Globals for path names, and such 272 */ 273 char *ld_elf_hints_default = _PATH_ELF_HINTS; 274 char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 275 char *ld_path_rtld = _PATH_RTLD; 276 char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 277 char *ld_env_prefix = LD_; 278 279 /* 280 * Fill in a DoneList with an allocation large enough to hold all of 281 * the currently-loaded objects. Keep this as a macro since it calls 282 * alloca and we want that to occur within the scope of the caller. 283 */ 284 #define donelist_init(dlp) \ 285 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 286 assert((dlp)->objs != NULL), \ 287 (dlp)->num_alloc = obj_count, \ 288 (dlp)->num_used = 0) 289 290 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 291 if (ld_utrace != NULL) \ 292 ld_utrace_log(e, h, mb, ms, r, n); \ 293 } while (0) 294 295 static void 296 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 297 int refcnt, const char *name) 298 { 299 struct utrace_rtld ut; 300 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 301 302 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 303 ut.event = event; 304 ut.handle = handle; 305 ut.mapbase = mapbase; 306 ut.mapsize = mapsize; 307 ut.refcnt = refcnt; 308 bzero(ut.name, sizeof(ut.name)); 309 if (name) 310 strlcpy(ut.name, name, sizeof(ut.name)); 311 utrace(&ut, sizeof(ut)); 312 } 313 314 #ifdef RTLD_VARIANT_ENV_NAMES 315 /* 316 * construct the env variable based on the type of binary that's 317 * running. 318 */ 319 static inline const char * 320 _LD(const char *var) 321 { 322 static char buffer[128]; 323 324 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 325 strlcat(buffer, var, sizeof(buffer)); 326 return (buffer); 327 } 328 #else 329 #define _LD(x) LD_ x 330 #endif 331 332 /* 333 * Main entry point for dynamic linking. The first argument is the 334 * stack pointer. The stack is expected to be laid out as described 335 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 336 * Specifically, the stack pointer points to a word containing 337 * ARGC. Following that in the stack is a null-terminated sequence 338 * of pointers to argument strings. Then comes a null-terminated 339 * sequence of pointers to environment strings. Finally, there is a 340 * sequence of "auxiliary vector" entries. 341 * 342 * The second argument points to a place to store the dynamic linker's 343 * exit procedure pointer and the third to a place to store the main 344 * program's object. 345 * 346 * The return value is the main program's entry point. 347 */ 348 func_ptr_type 349 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 350 { 351 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 352 Objlist_Entry *entry; 353 Obj_Entry *last_interposer, *obj, *preload_tail; 354 const Elf_Phdr *phdr; 355 Objlist initlist; 356 RtldLockState lockstate; 357 struct stat st; 358 Elf_Addr *argcp; 359 char **argv, *argv0, **env, **envp, *kexecpath, *library_path_rpath; 360 caddr_t imgentry; 361 char buf[MAXPATHLEN]; 362 int argc, fd, i, phnum, rtld_argc; 363 bool dir_enable, explicit_fd, search_in_path; 364 365 /* 366 * On entry, the dynamic linker itself has not been relocated yet. 367 * Be very careful not to reference any global data until after 368 * init_rtld has returned. It is OK to reference file-scope statics 369 * and string constants, and to call static and global functions. 370 */ 371 372 /* Find the auxiliary vector on the stack. */ 373 argcp = sp; 374 argc = *sp++; 375 argv = (char **) sp; 376 sp += argc + 1; /* Skip over arguments and NULL terminator */ 377 env = (char **) sp; 378 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 379 ; 380 aux = (Elf_Auxinfo *) sp; 381 382 /* Digest the auxiliary vector. */ 383 for (i = 0; i < AT_COUNT; i++) 384 aux_info[i] = NULL; 385 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 386 if (auxp->a_type < AT_COUNT) 387 aux_info[auxp->a_type] = auxp; 388 } 389 390 /* Initialize and relocate ourselves. */ 391 assert(aux_info[AT_BASE] != NULL); 392 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 393 394 __progname = obj_rtld.path; 395 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 396 environ = env; 397 main_argc = argc; 398 main_argv = argv; 399 400 trust = !issetugid(); 401 402 md_abi_variant_hook(aux_info); 403 404 fd = -1; 405 if (aux_info[AT_EXECFD] != NULL) { 406 fd = aux_info[AT_EXECFD]->a_un.a_val; 407 } else { 408 assert(aux_info[AT_PHDR] != NULL); 409 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 410 if (phdr == obj_rtld.phdr) { 411 if (!trust) { 412 _rtld_error("Tainted process refusing to run binary %s", 413 argv0); 414 rtld_die(); 415 } 416 dbg("opening main program in direct exec mode"); 417 if (argc >= 2) { 418 rtld_argc = parse_args(argv, argc, &search_in_path, &fd); 419 argv0 = argv[rtld_argc]; 420 explicit_fd = (fd != -1); 421 if (!explicit_fd) 422 fd = open_binary_fd(argv0, search_in_path); 423 if (fstat(fd, &st) == -1) { 424 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 425 explicit_fd ? "user-provided descriptor" : argv0, 426 rtld_strerror(errno)); 427 rtld_die(); 428 } 429 430 /* 431 * Rough emulation of the permission checks done by 432 * execve(2), only Unix DACs are checked, ACLs are 433 * ignored. Preserve the semantic of disabling owner 434 * to execute if owner x bit is cleared, even if 435 * others x bit is enabled. 436 * mmap(2) does not allow to mmap with PROT_EXEC if 437 * binary' file comes from noexec mount. We cannot 438 * set VV_TEXT on the binary. 439 */ 440 dir_enable = false; 441 if (st.st_uid == geteuid()) { 442 if ((st.st_mode & S_IXUSR) != 0) 443 dir_enable = true; 444 } else if (st.st_gid == getegid()) { 445 if ((st.st_mode & S_IXGRP) != 0) 446 dir_enable = true; 447 } else if ((st.st_mode & S_IXOTH) != 0) { 448 dir_enable = true; 449 } 450 if (!dir_enable) { 451 _rtld_error("No execute permission for binary %s", 452 argv0); 453 rtld_die(); 454 } 455 456 /* 457 * For direct exec mode, argv[0] is the interpreter 458 * name, we must remove it and shift arguments left 459 * before invoking binary main. Since stack layout 460 * places environment pointers and aux vectors right 461 * after the terminating NULL, we must shift 462 * environment and aux as well. 463 */ 464 main_argc = argc - rtld_argc; 465 for (i = 0; i <= main_argc; i++) 466 argv[i] = argv[i + rtld_argc]; 467 *argcp -= rtld_argc; 468 environ = env = envp = argv + main_argc + 1; 469 do { 470 *envp = *(envp + rtld_argc); 471 envp++; 472 } while (*envp != NULL); 473 aux = auxp = (Elf_Auxinfo *)envp; 474 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 475 for (;; auxp++, auxpf++) { 476 *auxp = *auxpf; 477 if (auxp->a_type == AT_NULL) 478 break; 479 } 480 } else { 481 _rtld_error("No binary"); 482 rtld_die(); 483 } 484 } 485 } 486 487 ld_bind_now = getenv(_LD("BIND_NOW")); 488 489 /* 490 * If the process is tainted, then we un-set the dangerous environment 491 * variables. The process will be marked as tainted until setuid(2) 492 * is called. If any child process calls setuid(2) we do not want any 493 * future processes to honor the potentially un-safe variables. 494 */ 495 if (!trust) { 496 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 497 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 498 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 499 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 500 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) { 501 _rtld_error("environment corrupt; aborting"); 502 rtld_die(); 503 } 504 } 505 ld_debug = getenv(_LD("DEBUG")); 506 if (ld_bind_now == NULL) 507 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 508 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 509 libmap_override = getenv(_LD("LIBMAP")); 510 ld_library_path = getenv(_LD("LIBRARY_PATH")); 511 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 512 ld_preload = getenv(_LD("PRELOAD")); 513 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 514 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 515 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 516 if (library_path_rpath != NULL) { 517 if (library_path_rpath[0] == 'y' || 518 library_path_rpath[0] == 'Y' || 519 library_path_rpath[0] == '1') 520 ld_library_path_rpath = true; 521 else 522 ld_library_path_rpath = false; 523 } 524 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 525 (ld_library_path != NULL) || (ld_preload != NULL) || 526 (ld_elf_hints_path != NULL) || ld_loadfltr; 527 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 528 ld_utrace = getenv(_LD("UTRACE")); 529 530 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 531 ld_elf_hints_path = ld_elf_hints_default; 532 533 if (ld_debug != NULL && *ld_debug != '\0') 534 debug = 1; 535 dbg("%s is initialized, base address = %p", __progname, 536 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 537 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 538 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 539 540 dbg("initializing thread locks"); 541 lockdflt_init(); 542 543 /* 544 * Load the main program, or process its program header if it is 545 * already loaded. 546 */ 547 if (fd != -1) { /* Load the main program. */ 548 dbg("loading main program"); 549 obj_main = map_object(fd, argv0, NULL); 550 close(fd); 551 if (obj_main == NULL) 552 rtld_die(); 553 max_stack_flags = obj_main->stack_flags; 554 } else { /* Main program already loaded. */ 555 dbg("processing main program's program header"); 556 assert(aux_info[AT_PHDR] != NULL); 557 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 558 assert(aux_info[AT_PHNUM] != NULL); 559 phnum = aux_info[AT_PHNUM]->a_un.a_val; 560 assert(aux_info[AT_PHENT] != NULL); 561 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 562 assert(aux_info[AT_ENTRY] != NULL); 563 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 564 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 565 rtld_die(); 566 } 567 568 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 569 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 570 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 571 if (kexecpath[0] == '/') 572 obj_main->path = kexecpath; 573 else if (getcwd(buf, sizeof(buf)) == NULL || 574 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 575 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 576 obj_main->path = xstrdup(argv0); 577 else 578 obj_main->path = xstrdup(buf); 579 } else { 580 dbg("No AT_EXECPATH or direct exec"); 581 obj_main->path = xstrdup(argv0); 582 } 583 dbg("obj_main path %s", obj_main->path); 584 obj_main->mainprog = true; 585 586 if (aux_info[AT_STACKPROT] != NULL && 587 aux_info[AT_STACKPROT]->a_un.a_val != 0) 588 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 589 590 #ifndef COMPAT_32BIT 591 /* 592 * Get the actual dynamic linker pathname from the executable if 593 * possible. (It should always be possible.) That ensures that 594 * gdb will find the right dynamic linker even if a non-standard 595 * one is being used. 596 */ 597 if (obj_main->interp != NULL && 598 strcmp(obj_main->interp, obj_rtld.path) != 0) { 599 free(obj_rtld.path); 600 obj_rtld.path = xstrdup(obj_main->interp); 601 __progname = obj_rtld.path; 602 } 603 #endif 604 605 digest_dynamic(obj_main, 0); 606 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 607 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 608 obj_main->dynsymcount); 609 610 linkmap_add(obj_main); 611 linkmap_add(&obj_rtld); 612 613 /* Link the main program into the list of objects. */ 614 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 615 obj_count++; 616 obj_loads++; 617 618 /* Initialize a fake symbol for resolving undefined weak references. */ 619 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 620 sym_zero.st_shndx = SHN_UNDEF; 621 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 622 623 if (!libmap_disable) 624 libmap_disable = (bool)lm_init(libmap_override); 625 626 dbg("loading LD_PRELOAD libraries"); 627 if (load_preload_objects() == -1) 628 rtld_die(); 629 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 630 631 dbg("loading needed objects"); 632 if (load_needed_objects(obj_main, 0) == -1) 633 rtld_die(); 634 635 /* Make a list of all objects loaded at startup. */ 636 last_interposer = obj_main; 637 TAILQ_FOREACH(obj, &obj_list, next) { 638 if (obj->marker) 639 continue; 640 if (obj->z_interpose && obj != obj_main) { 641 objlist_put_after(&list_main, last_interposer, obj); 642 last_interposer = obj; 643 } else { 644 objlist_push_tail(&list_main, obj); 645 } 646 obj->refcount++; 647 } 648 649 dbg("checking for required versions"); 650 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 651 rtld_die(); 652 653 if (ld_tracing) { /* We're done */ 654 trace_loaded_objects(obj_main); 655 exit(0); 656 } 657 658 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 659 dump_relocations(obj_main); 660 exit (0); 661 } 662 663 /* 664 * Processing tls relocations requires having the tls offsets 665 * initialized. Prepare offsets before starting initial 666 * relocation processing. 667 */ 668 dbg("initializing initial thread local storage offsets"); 669 STAILQ_FOREACH(entry, &list_main, link) { 670 /* 671 * Allocate all the initial objects out of the static TLS 672 * block even if they didn't ask for it. 673 */ 674 allocate_tls_offset(entry->obj); 675 } 676 677 if (relocate_objects(obj_main, 678 ld_bind_now != NULL && *ld_bind_now != '\0', 679 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 680 rtld_die(); 681 682 dbg("doing copy relocations"); 683 if (do_copy_relocations(obj_main) == -1) 684 rtld_die(); 685 686 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 687 dump_relocations(obj_main); 688 exit (0); 689 } 690 691 ifunc_init(aux); 692 693 /* 694 * Setup TLS for main thread. This must be done after the 695 * relocations are processed, since tls initialization section 696 * might be the subject for relocations. 697 */ 698 dbg("initializing initial thread local storage"); 699 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 700 701 dbg("initializing key program variables"); 702 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 703 set_program_var("environ", env); 704 set_program_var("__elf_aux_vector", aux); 705 706 /* Make a list of init functions to call. */ 707 objlist_init(&initlist); 708 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 709 preload_tail, &initlist); 710 711 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 712 713 map_stacks_exec(NULL); 714 715 dbg("resolving ifuncs"); 716 if (resolve_objects_ifunc(obj_main, 717 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 718 NULL) == -1) 719 rtld_die(); 720 721 dbg("enforcing main obj relro"); 722 if (obj_enforce_relro(obj_main) == -1) 723 rtld_die(); 724 725 if (!obj_main->crt_no_init) { 726 /* 727 * Make sure we don't call the main program's init and fini 728 * functions for binaries linked with old crt1 which calls 729 * _init itself. 730 */ 731 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 732 obj_main->preinit_array = obj_main->init_array = 733 obj_main->fini_array = (Elf_Addr)NULL; 734 } 735 736 /* 737 * Execute MD initializers required before we call the objects' 738 * init functions. 739 */ 740 pre_init(); 741 742 wlock_acquire(rtld_bind_lock, &lockstate); 743 if (obj_main->crt_no_init) 744 preinit_main(); 745 objlist_call_init(&initlist, &lockstate); 746 _r_debug_postinit(&obj_main->linkmap); 747 objlist_clear(&initlist); 748 dbg("loading filtees"); 749 TAILQ_FOREACH(obj, &obj_list, next) { 750 if (obj->marker) 751 continue; 752 if (ld_loadfltr || obj->z_loadfltr) 753 load_filtees(obj, 0, &lockstate); 754 } 755 lock_release(rtld_bind_lock, &lockstate); 756 757 dbg("transferring control to program entry point = %p", obj_main->entry); 758 759 /* Return the exit procedure and the program entry point. */ 760 *exit_proc = rtld_exit; 761 *objp = obj_main; 762 return (func_ptr_type) obj_main->entry; 763 } 764 765 void * 766 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 767 { 768 void *ptr; 769 Elf_Addr target; 770 771 ptr = (void *)make_function_pointer(def, obj); 772 target = call_ifunc_resolver(ptr); 773 return ((void *)target); 774 } 775 776 /* 777 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 778 * Changes to this function should be applied there as well. 779 */ 780 Elf_Addr 781 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 782 { 783 const Elf_Rel *rel; 784 const Elf_Sym *def; 785 const Obj_Entry *defobj; 786 Elf_Addr *where; 787 Elf_Addr target; 788 RtldLockState lockstate; 789 790 rlock_acquire(rtld_bind_lock, &lockstate); 791 if (sigsetjmp(lockstate.env, 0) != 0) 792 lock_upgrade(rtld_bind_lock, &lockstate); 793 if (obj->pltrel) 794 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 795 else 796 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 797 798 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 799 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 800 NULL, &lockstate); 801 if (def == NULL) 802 rtld_die(); 803 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 804 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 805 else 806 target = (Elf_Addr)(defobj->relocbase + def->st_value); 807 808 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 809 defobj->strtab + def->st_name, basename(obj->path), 810 (void *)target, basename(defobj->path)); 811 812 /* 813 * Write the new contents for the jmpslot. Note that depending on 814 * architecture, the value which we need to return back to the 815 * lazy binding trampoline may or may not be the target 816 * address. The value returned from reloc_jmpslot() is the value 817 * that the trampoline needs. 818 */ 819 target = reloc_jmpslot(where, target, defobj, obj, rel); 820 lock_release(rtld_bind_lock, &lockstate); 821 return target; 822 } 823 824 /* 825 * Error reporting function. Use it like printf. If formats the message 826 * into a buffer, and sets things up so that the next call to dlerror() 827 * will return the message. 828 */ 829 void 830 _rtld_error(const char *fmt, ...) 831 { 832 static char buf[512]; 833 va_list ap; 834 835 va_start(ap, fmt); 836 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 837 error_message = buf; 838 va_end(ap); 839 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message); 840 } 841 842 /* 843 * Return a dynamically-allocated copy of the current error message, if any. 844 */ 845 static char * 846 errmsg_save(void) 847 { 848 return error_message == NULL ? NULL : xstrdup(error_message); 849 } 850 851 /* 852 * Restore the current error message from a copy which was previously saved 853 * by errmsg_save(). The copy is freed. 854 */ 855 static void 856 errmsg_restore(char *saved_msg) 857 { 858 if (saved_msg == NULL) 859 error_message = NULL; 860 else { 861 _rtld_error("%s", saved_msg); 862 free(saved_msg); 863 } 864 } 865 866 static const char * 867 basename(const char *name) 868 { 869 const char *p = strrchr(name, '/'); 870 return p != NULL ? p + 1 : name; 871 } 872 873 static struct utsname uts; 874 875 static char * 876 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 877 const char *subst, bool may_free) 878 { 879 char *p, *p1, *res, *resp; 880 int subst_len, kw_len, subst_count, old_len, new_len; 881 882 kw_len = strlen(kw); 883 884 /* 885 * First, count the number of the keyword occurrences, to 886 * preallocate the final string. 887 */ 888 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 889 p1 = strstr(p, kw); 890 if (p1 == NULL) 891 break; 892 } 893 894 /* 895 * If the keyword is not found, just return. 896 * 897 * Return non-substituted string if resolution failed. We 898 * cannot do anything more reasonable, the failure mode of the 899 * caller is unresolved library anyway. 900 */ 901 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 902 return (may_free ? real : xstrdup(real)); 903 if (obj != NULL) 904 subst = obj->origin_path; 905 906 /* 907 * There is indeed something to substitute. Calculate the 908 * length of the resulting string, and allocate it. 909 */ 910 subst_len = strlen(subst); 911 old_len = strlen(real); 912 new_len = old_len + (subst_len - kw_len) * subst_count; 913 res = xmalloc(new_len + 1); 914 915 /* 916 * Now, execute the substitution loop. 917 */ 918 for (p = real, resp = res, *resp = '\0';;) { 919 p1 = strstr(p, kw); 920 if (p1 != NULL) { 921 /* Copy the prefix before keyword. */ 922 memcpy(resp, p, p1 - p); 923 resp += p1 - p; 924 /* Keyword replacement. */ 925 memcpy(resp, subst, subst_len); 926 resp += subst_len; 927 *resp = '\0'; 928 p = p1 + kw_len; 929 } else 930 break; 931 } 932 933 /* Copy to the end of string and finish. */ 934 strcat(resp, p); 935 if (may_free) 936 free(real); 937 return (res); 938 } 939 940 static char * 941 origin_subst(Obj_Entry *obj, char *real) 942 { 943 char *res1, *res2, *res3, *res4; 944 945 if (obj == NULL || !trust) 946 return (xstrdup(real)); 947 if (uts.sysname[0] == '\0') { 948 if (uname(&uts) != 0) { 949 _rtld_error("utsname failed: %d", errno); 950 return (NULL); 951 } 952 } 953 res1 = origin_subst_one(obj, real, "$ORIGIN", NULL, false); 954 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 955 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 956 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 957 return (res4); 958 } 959 960 void 961 rtld_die(void) 962 { 963 const char *msg = dlerror(); 964 965 if (msg == NULL) 966 msg = "Fatal error"; 967 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 968 rtld_fdputstr(STDERR_FILENO, msg); 969 rtld_fdputchar(STDERR_FILENO, '\n'); 970 _exit(1); 971 } 972 973 /* 974 * Process a shared object's DYNAMIC section, and save the important 975 * information in its Obj_Entry structure. 976 */ 977 static void 978 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 979 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 980 { 981 const Elf_Dyn *dynp; 982 Needed_Entry **needed_tail = &obj->needed; 983 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 984 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 985 const Elf_Hashelt *hashtab; 986 const Elf32_Word *hashval; 987 Elf32_Word bkt, nmaskwords; 988 int bloom_size32; 989 int plttype = DT_REL; 990 991 *dyn_rpath = NULL; 992 *dyn_soname = NULL; 993 *dyn_runpath = NULL; 994 995 obj->bind_now = false; 996 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 997 switch (dynp->d_tag) { 998 999 case DT_REL: 1000 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 1001 break; 1002 1003 case DT_RELSZ: 1004 obj->relsize = dynp->d_un.d_val; 1005 break; 1006 1007 case DT_RELENT: 1008 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1009 break; 1010 1011 case DT_JMPREL: 1012 obj->pltrel = (const Elf_Rel *) 1013 (obj->relocbase + dynp->d_un.d_ptr); 1014 break; 1015 1016 case DT_PLTRELSZ: 1017 obj->pltrelsize = dynp->d_un.d_val; 1018 break; 1019 1020 case DT_RELA: 1021 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 1022 break; 1023 1024 case DT_RELASZ: 1025 obj->relasize = dynp->d_un.d_val; 1026 break; 1027 1028 case DT_RELAENT: 1029 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1030 break; 1031 1032 case DT_PLTREL: 1033 plttype = dynp->d_un.d_val; 1034 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1035 break; 1036 1037 case DT_SYMTAB: 1038 obj->symtab = (const Elf_Sym *) 1039 (obj->relocbase + dynp->d_un.d_ptr); 1040 break; 1041 1042 case DT_SYMENT: 1043 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1044 break; 1045 1046 case DT_STRTAB: 1047 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 1048 break; 1049 1050 case DT_STRSZ: 1051 obj->strsize = dynp->d_un.d_val; 1052 break; 1053 1054 case DT_VERNEED: 1055 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 1056 dynp->d_un.d_val); 1057 break; 1058 1059 case DT_VERNEEDNUM: 1060 obj->verneednum = dynp->d_un.d_val; 1061 break; 1062 1063 case DT_VERDEF: 1064 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 1065 dynp->d_un.d_val); 1066 break; 1067 1068 case DT_VERDEFNUM: 1069 obj->verdefnum = dynp->d_un.d_val; 1070 break; 1071 1072 case DT_VERSYM: 1073 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1074 dynp->d_un.d_val); 1075 break; 1076 1077 case DT_HASH: 1078 { 1079 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1080 dynp->d_un.d_ptr); 1081 obj->nbuckets = hashtab[0]; 1082 obj->nchains = hashtab[1]; 1083 obj->buckets = hashtab + 2; 1084 obj->chains = obj->buckets + obj->nbuckets; 1085 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1086 obj->buckets != NULL; 1087 } 1088 break; 1089 1090 case DT_GNU_HASH: 1091 { 1092 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1093 dynp->d_un.d_ptr); 1094 obj->nbuckets_gnu = hashtab[0]; 1095 obj->symndx_gnu = hashtab[1]; 1096 nmaskwords = hashtab[2]; 1097 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1098 obj->maskwords_bm_gnu = nmaskwords - 1; 1099 obj->shift2_gnu = hashtab[3]; 1100 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 1101 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1102 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1103 obj->symndx_gnu; 1104 /* Number of bitmask words is required to be power of 2 */ 1105 obj->valid_hash_gnu = powerof2(nmaskwords) && 1106 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1107 } 1108 break; 1109 1110 case DT_NEEDED: 1111 if (!obj->rtld) { 1112 Needed_Entry *nep = NEW(Needed_Entry); 1113 nep->name = dynp->d_un.d_val; 1114 nep->obj = NULL; 1115 nep->next = NULL; 1116 1117 *needed_tail = nep; 1118 needed_tail = &nep->next; 1119 } 1120 break; 1121 1122 case DT_FILTER: 1123 if (!obj->rtld) { 1124 Needed_Entry *nep = NEW(Needed_Entry); 1125 nep->name = dynp->d_un.d_val; 1126 nep->obj = NULL; 1127 nep->next = NULL; 1128 1129 *needed_filtees_tail = nep; 1130 needed_filtees_tail = &nep->next; 1131 } 1132 break; 1133 1134 case DT_AUXILIARY: 1135 if (!obj->rtld) { 1136 Needed_Entry *nep = NEW(Needed_Entry); 1137 nep->name = dynp->d_un.d_val; 1138 nep->obj = NULL; 1139 nep->next = NULL; 1140 1141 *needed_aux_filtees_tail = nep; 1142 needed_aux_filtees_tail = &nep->next; 1143 } 1144 break; 1145 1146 case DT_PLTGOT: 1147 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1148 break; 1149 1150 case DT_TEXTREL: 1151 obj->textrel = true; 1152 break; 1153 1154 case DT_SYMBOLIC: 1155 obj->symbolic = true; 1156 break; 1157 1158 case DT_RPATH: 1159 /* 1160 * We have to wait until later to process this, because we 1161 * might not have gotten the address of the string table yet. 1162 */ 1163 *dyn_rpath = dynp; 1164 break; 1165 1166 case DT_SONAME: 1167 *dyn_soname = dynp; 1168 break; 1169 1170 case DT_RUNPATH: 1171 *dyn_runpath = dynp; 1172 break; 1173 1174 case DT_INIT: 1175 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1176 break; 1177 1178 case DT_PREINIT_ARRAY: 1179 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1180 break; 1181 1182 case DT_PREINIT_ARRAYSZ: 1183 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1184 break; 1185 1186 case DT_INIT_ARRAY: 1187 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1188 break; 1189 1190 case DT_INIT_ARRAYSZ: 1191 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1192 break; 1193 1194 case DT_FINI: 1195 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1196 break; 1197 1198 case DT_FINI_ARRAY: 1199 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1200 break; 1201 1202 case DT_FINI_ARRAYSZ: 1203 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1204 break; 1205 1206 /* 1207 * Don't process DT_DEBUG on MIPS as the dynamic section 1208 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1209 */ 1210 1211 #ifndef __mips__ 1212 case DT_DEBUG: 1213 if (!early) 1214 dbg("Filling in DT_DEBUG entry"); 1215 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1216 break; 1217 #endif 1218 1219 case DT_FLAGS: 1220 if (dynp->d_un.d_val & DF_ORIGIN) 1221 obj->z_origin = true; 1222 if (dynp->d_un.d_val & DF_SYMBOLIC) 1223 obj->symbolic = true; 1224 if (dynp->d_un.d_val & DF_TEXTREL) 1225 obj->textrel = true; 1226 if (dynp->d_un.d_val & DF_BIND_NOW) 1227 obj->bind_now = true; 1228 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1229 ;*/ 1230 break; 1231 #ifdef __mips__ 1232 case DT_MIPS_LOCAL_GOTNO: 1233 obj->local_gotno = dynp->d_un.d_val; 1234 break; 1235 1236 case DT_MIPS_SYMTABNO: 1237 obj->symtabno = dynp->d_un.d_val; 1238 break; 1239 1240 case DT_MIPS_GOTSYM: 1241 obj->gotsym = dynp->d_un.d_val; 1242 break; 1243 1244 case DT_MIPS_RLD_MAP: 1245 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1246 break; 1247 1248 case DT_MIPS_PLTGOT: 1249 obj->mips_pltgot = (Elf_Addr *) (obj->relocbase + 1250 dynp->d_un.d_ptr); 1251 break; 1252 1253 #endif 1254 1255 #ifdef __powerpc64__ 1256 case DT_PPC64_GLINK: 1257 obj->glink = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1258 break; 1259 #endif 1260 1261 case DT_FLAGS_1: 1262 if (dynp->d_un.d_val & DF_1_NOOPEN) 1263 obj->z_noopen = true; 1264 if (dynp->d_un.d_val & DF_1_ORIGIN) 1265 obj->z_origin = true; 1266 if (dynp->d_un.d_val & DF_1_GLOBAL) 1267 obj->z_global = true; 1268 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1269 obj->bind_now = true; 1270 if (dynp->d_un.d_val & DF_1_NODELETE) 1271 obj->z_nodelete = true; 1272 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1273 obj->z_loadfltr = true; 1274 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1275 obj->z_interpose = true; 1276 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1277 obj->z_nodeflib = true; 1278 break; 1279 1280 default: 1281 if (!early) { 1282 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1283 (long)dynp->d_tag); 1284 } 1285 break; 1286 } 1287 } 1288 1289 obj->traced = false; 1290 1291 if (plttype == DT_RELA) { 1292 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1293 obj->pltrel = NULL; 1294 obj->pltrelasize = obj->pltrelsize; 1295 obj->pltrelsize = 0; 1296 } 1297 1298 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1299 if (obj->valid_hash_sysv) 1300 obj->dynsymcount = obj->nchains; 1301 else if (obj->valid_hash_gnu) { 1302 obj->dynsymcount = 0; 1303 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1304 if (obj->buckets_gnu[bkt] == 0) 1305 continue; 1306 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1307 do 1308 obj->dynsymcount++; 1309 while ((*hashval++ & 1u) == 0); 1310 } 1311 obj->dynsymcount += obj->symndx_gnu; 1312 } 1313 } 1314 1315 static bool 1316 obj_resolve_origin(Obj_Entry *obj) 1317 { 1318 1319 if (obj->origin_path != NULL) 1320 return (true); 1321 obj->origin_path = xmalloc(PATH_MAX); 1322 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1323 } 1324 1325 static void 1326 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1327 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1328 { 1329 1330 if (obj->z_origin && !obj_resolve_origin(obj)) 1331 rtld_die(); 1332 1333 if (dyn_runpath != NULL) { 1334 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1335 obj->runpath = origin_subst(obj, obj->runpath); 1336 } else if (dyn_rpath != NULL) { 1337 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1338 obj->rpath = origin_subst(obj, obj->rpath); 1339 } 1340 if (dyn_soname != NULL) 1341 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1342 } 1343 1344 static void 1345 digest_dynamic(Obj_Entry *obj, int early) 1346 { 1347 const Elf_Dyn *dyn_rpath; 1348 const Elf_Dyn *dyn_soname; 1349 const Elf_Dyn *dyn_runpath; 1350 1351 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1352 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1353 } 1354 1355 /* 1356 * Process a shared object's program header. This is used only for the 1357 * main program, when the kernel has already loaded the main program 1358 * into memory before calling the dynamic linker. It creates and 1359 * returns an Obj_Entry structure. 1360 */ 1361 static Obj_Entry * 1362 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1363 { 1364 Obj_Entry *obj; 1365 const Elf_Phdr *phlimit = phdr + phnum; 1366 const Elf_Phdr *ph; 1367 Elf_Addr note_start, note_end; 1368 int nsegs = 0; 1369 1370 obj = obj_new(); 1371 for (ph = phdr; ph < phlimit; ph++) { 1372 if (ph->p_type != PT_PHDR) 1373 continue; 1374 1375 obj->phdr = phdr; 1376 obj->phsize = ph->p_memsz; 1377 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1378 break; 1379 } 1380 1381 obj->stack_flags = PF_X | PF_R | PF_W; 1382 1383 for (ph = phdr; ph < phlimit; ph++) { 1384 switch (ph->p_type) { 1385 1386 case PT_INTERP: 1387 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1388 break; 1389 1390 case PT_LOAD: 1391 if (nsegs == 0) { /* First load segment */ 1392 obj->vaddrbase = trunc_page(ph->p_vaddr); 1393 obj->mapbase = obj->vaddrbase + obj->relocbase; 1394 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1395 obj->vaddrbase; 1396 } else { /* Last load segment */ 1397 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1398 obj->vaddrbase; 1399 } 1400 nsegs++; 1401 break; 1402 1403 case PT_DYNAMIC: 1404 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1405 break; 1406 1407 case PT_TLS: 1408 obj->tlsindex = 1; 1409 obj->tlssize = ph->p_memsz; 1410 obj->tlsalign = ph->p_align; 1411 obj->tlsinitsize = ph->p_filesz; 1412 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1413 break; 1414 1415 case PT_GNU_STACK: 1416 obj->stack_flags = ph->p_flags; 1417 break; 1418 1419 case PT_GNU_RELRO: 1420 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1421 obj->relro_size = round_page(ph->p_memsz); 1422 break; 1423 1424 case PT_NOTE: 1425 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1426 note_end = note_start + ph->p_filesz; 1427 digest_notes(obj, note_start, note_end); 1428 break; 1429 } 1430 } 1431 if (nsegs < 1) { 1432 _rtld_error("%s: too few PT_LOAD segments", path); 1433 return NULL; 1434 } 1435 1436 obj->entry = entry; 1437 return obj; 1438 } 1439 1440 void 1441 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1442 { 1443 const Elf_Note *note; 1444 const char *note_name; 1445 uintptr_t p; 1446 1447 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1448 note = (const Elf_Note *)((const char *)(note + 1) + 1449 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1450 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1451 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1452 note->n_descsz != sizeof(int32_t)) 1453 continue; 1454 if (note->n_type != NT_FREEBSD_ABI_TAG && 1455 note->n_type != NT_FREEBSD_NOINIT_TAG) 1456 continue; 1457 note_name = (const char *)(note + 1); 1458 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1459 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1460 continue; 1461 switch (note->n_type) { 1462 case NT_FREEBSD_ABI_TAG: 1463 /* FreeBSD osrel note */ 1464 p = (uintptr_t)(note + 1); 1465 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1466 obj->osrel = *(const int32_t *)(p); 1467 dbg("note osrel %d", obj->osrel); 1468 break; 1469 case NT_FREEBSD_NOINIT_TAG: 1470 /* FreeBSD 'crt does not call init' note */ 1471 obj->crt_no_init = true; 1472 dbg("note crt_no_init"); 1473 break; 1474 } 1475 } 1476 } 1477 1478 static Obj_Entry * 1479 dlcheck(void *handle) 1480 { 1481 Obj_Entry *obj; 1482 1483 TAILQ_FOREACH(obj, &obj_list, next) { 1484 if (obj == (Obj_Entry *) handle) 1485 break; 1486 } 1487 1488 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1489 _rtld_error("Invalid shared object handle %p", handle); 1490 return NULL; 1491 } 1492 return obj; 1493 } 1494 1495 /* 1496 * If the given object is already in the donelist, return true. Otherwise 1497 * add the object to the list and return false. 1498 */ 1499 static bool 1500 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1501 { 1502 unsigned int i; 1503 1504 for (i = 0; i < dlp->num_used; i++) 1505 if (dlp->objs[i] == obj) 1506 return true; 1507 /* 1508 * Our donelist allocation should always be sufficient. But if 1509 * our threads locking isn't working properly, more shared objects 1510 * could have been loaded since we allocated the list. That should 1511 * never happen, but we'll handle it properly just in case it does. 1512 */ 1513 if (dlp->num_used < dlp->num_alloc) 1514 dlp->objs[dlp->num_used++] = obj; 1515 return false; 1516 } 1517 1518 /* 1519 * Hash function for symbol table lookup. Don't even think about changing 1520 * this. It is specified by the System V ABI. 1521 */ 1522 unsigned long 1523 elf_hash(const char *name) 1524 { 1525 const unsigned char *p = (const unsigned char *) name; 1526 unsigned long h = 0; 1527 unsigned long g; 1528 1529 while (*p != '\0') { 1530 h = (h << 4) + *p++; 1531 if ((g = h & 0xf0000000) != 0) 1532 h ^= g >> 24; 1533 h &= ~g; 1534 } 1535 return h; 1536 } 1537 1538 /* 1539 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1540 * unsigned in case it's implemented with a wider type. 1541 */ 1542 static uint32_t 1543 gnu_hash(const char *s) 1544 { 1545 uint32_t h; 1546 unsigned char c; 1547 1548 h = 5381; 1549 for (c = *s; c != '\0'; c = *++s) 1550 h = h * 33 + c; 1551 return (h & 0xffffffff); 1552 } 1553 1554 1555 /* 1556 * Find the library with the given name, and return its full pathname. 1557 * The returned string is dynamically allocated. Generates an error 1558 * message and returns NULL if the library cannot be found. 1559 * 1560 * If the second argument is non-NULL, then it refers to an already- 1561 * loaded shared object, whose library search path will be searched. 1562 * 1563 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1564 * descriptor (which is close-on-exec) will be passed out via the third 1565 * argument. 1566 * 1567 * The search order is: 1568 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1569 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1570 * LD_LIBRARY_PATH 1571 * DT_RUNPATH in the referencing file 1572 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1573 * from list) 1574 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1575 * 1576 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1577 */ 1578 static char * 1579 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1580 { 1581 char *name, *pathname, *refobj_path; 1582 bool nodeflib, objgiven; 1583 1584 objgiven = refobj != NULL; 1585 1586 if (libmap_disable || !objgiven || 1587 (name = lm_find(refobj->path, xname)) == NULL) 1588 name = (char *)xname; 1589 1590 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1591 if (name[0] != '/' && !trust) { 1592 _rtld_error("Absolute pathname required " 1593 "for shared object \"%s\"", name); 1594 return (NULL); 1595 } 1596 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1597 __DECONST(char *, name))); 1598 } 1599 1600 dbg(" Searching for \"%s\"", name); 1601 refobj_path = objgiven ? refobj->path : NULL; 1602 1603 /* 1604 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1605 * back to pre-conforming behaviour if user requested so with 1606 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1607 * nodeflib. 1608 */ 1609 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1610 pathname = search_library_path(name, ld_library_path, 1611 refobj_path, fdp); 1612 if (pathname != NULL) 1613 return (pathname); 1614 if (refobj != NULL) { 1615 pathname = search_library_path(name, refobj->rpath, 1616 refobj_path, fdp); 1617 if (pathname != NULL) 1618 return (pathname); 1619 } 1620 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1621 if (pathname != NULL) 1622 return (pathname); 1623 pathname = search_library_path(name, gethints(false), 1624 refobj_path, fdp); 1625 if (pathname != NULL) 1626 return (pathname); 1627 pathname = search_library_path(name, ld_standard_library_path, 1628 refobj_path, fdp); 1629 if (pathname != NULL) 1630 return (pathname); 1631 } else { 1632 nodeflib = objgiven ? refobj->z_nodeflib : false; 1633 if (objgiven) { 1634 pathname = search_library_path(name, refobj->rpath, 1635 refobj->path, fdp); 1636 if (pathname != NULL) 1637 return (pathname); 1638 } 1639 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1640 pathname = search_library_path(name, obj_main->rpath, 1641 refobj_path, fdp); 1642 if (pathname != NULL) 1643 return (pathname); 1644 } 1645 pathname = search_library_path(name, ld_library_path, 1646 refobj_path, fdp); 1647 if (pathname != NULL) 1648 return (pathname); 1649 if (objgiven) { 1650 pathname = search_library_path(name, refobj->runpath, 1651 refobj_path, fdp); 1652 if (pathname != NULL) 1653 return (pathname); 1654 } 1655 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1656 if (pathname != NULL) 1657 return (pathname); 1658 pathname = search_library_path(name, gethints(nodeflib), 1659 refobj_path, fdp); 1660 if (pathname != NULL) 1661 return (pathname); 1662 if (objgiven && !nodeflib) { 1663 pathname = search_library_path(name, 1664 ld_standard_library_path, refobj_path, fdp); 1665 if (pathname != NULL) 1666 return (pathname); 1667 } 1668 } 1669 1670 if (objgiven && refobj->path != NULL) { 1671 _rtld_error("Shared object \"%s\" not found, " 1672 "required by \"%s\"", name, basename(refobj->path)); 1673 } else { 1674 _rtld_error("Shared object \"%s\" not found", name); 1675 } 1676 return (NULL); 1677 } 1678 1679 /* 1680 * Given a symbol number in a referencing object, find the corresponding 1681 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1682 * no definition was found. Returns a pointer to the Obj_Entry of the 1683 * defining object via the reference parameter DEFOBJ_OUT. 1684 */ 1685 const Elf_Sym * 1686 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1687 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1688 RtldLockState *lockstate) 1689 { 1690 const Elf_Sym *ref; 1691 const Elf_Sym *def; 1692 const Obj_Entry *defobj; 1693 const Ver_Entry *ve; 1694 SymLook req; 1695 const char *name; 1696 int res; 1697 1698 /* 1699 * If we have already found this symbol, get the information from 1700 * the cache. 1701 */ 1702 if (symnum >= refobj->dynsymcount) 1703 return NULL; /* Bad object */ 1704 if (cache != NULL && cache[symnum].sym != NULL) { 1705 *defobj_out = cache[symnum].obj; 1706 return cache[symnum].sym; 1707 } 1708 1709 ref = refobj->symtab + symnum; 1710 name = refobj->strtab + ref->st_name; 1711 def = NULL; 1712 defobj = NULL; 1713 ve = NULL; 1714 1715 /* 1716 * We don't have to do a full scale lookup if the symbol is local. 1717 * We know it will bind to the instance in this load module; to 1718 * which we already have a pointer (ie ref). By not doing a lookup, 1719 * we not only improve performance, but it also avoids unresolvable 1720 * symbols when local symbols are not in the hash table. This has 1721 * been seen with the ia64 toolchain. 1722 */ 1723 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1724 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1725 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1726 symnum); 1727 } 1728 symlook_init(&req, name); 1729 req.flags = flags; 1730 ve = req.ventry = fetch_ventry(refobj, symnum); 1731 req.lockstate = lockstate; 1732 res = symlook_default(&req, refobj); 1733 if (res == 0) { 1734 def = req.sym_out; 1735 defobj = req.defobj_out; 1736 } 1737 } else { 1738 def = ref; 1739 defobj = refobj; 1740 } 1741 1742 /* 1743 * If we found no definition and the reference is weak, treat the 1744 * symbol as having the value zero. 1745 */ 1746 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1747 def = &sym_zero; 1748 defobj = obj_main; 1749 } 1750 1751 if (def != NULL) { 1752 *defobj_out = defobj; 1753 /* Record the information in the cache to avoid subsequent lookups. */ 1754 if (cache != NULL) { 1755 cache[symnum].sym = def; 1756 cache[symnum].obj = defobj; 1757 } 1758 } else { 1759 if (refobj != &obj_rtld) 1760 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1761 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1762 } 1763 return def; 1764 } 1765 1766 /* 1767 * Return the search path from the ldconfig hints file, reading it if 1768 * necessary. If nostdlib is true, then the default search paths are 1769 * not added to result. 1770 * 1771 * Returns NULL if there are problems with the hints file, 1772 * or if the search path there is empty. 1773 */ 1774 static const char * 1775 gethints(bool nostdlib) 1776 { 1777 static char *hints, *filtered_path; 1778 static struct elfhints_hdr hdr; 1779 struct fill_search_info_args sargs, hargs; 1780 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1781 struct dl_serpath *SLPpath, *hintpath; 1782 char *p; 1783 struct stat hint_stat; 1784 unsigned int SLPndx, hintndx, fndx, fcount; 1785 int fd; 1786 size_t flen; 1787 uint32_t dl; 1788 bool skip; 1789 1790 /* First call, read the hints file */ 1791 if (hints == NULL) { 1792 /* Keep from trying again in case the hints file is bad. */ 1793 hints = ""; 1794 1795 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1796 return (NULL); 1797 1798 /* 1799 * Check of hdr.dirlistlen value against type limit 1800 * intends to pacify static analyzers. Further 1801 * paranoia leads to checks that dirlist is fully 1802 * contained in the file range. 1803 */ 1804 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1805 hdr.magic != ELFHINTS_MAGIC || 1806 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1807 fstat(fd, &hint_stat) == -1) { 1808 cleanup1: 1809 close(fd); 1810 hdr.dirlistlen = 0; 1811 return (NULL); 1812 } 1813 dl = hdr.strtab; 1814 if (dl + hdr.dirlist < dl) 1815 goto cleanup1; 1816 dl += hdr.dirlist; 1817 if (dl + hdr.dirlistlen < dl) 1818 goto cleanup1; 1819 dl += hdr.dirlistlen; 1820 if (dl > hint_stat.st_size) 1821 goto cleanup1; 1822 p = xmalloc(hdr.dirlistlen + 1); 1823 if (pread(fd, p, hdr.dirlistlen + 1, 1824 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1825 p[hdr.dirlistlen] != '\0') { 1826 free(p); 1827 goto cleanup1; 1828 } 1829 hints = p; 1830 close(fd); 1831 } 1832 1833 /* 1834 * If caller agreed to receive list which includes the default 1835 * paths, we are done. Otherwise, if we still did not 1836 * calculated filtered result, do it now. 1837 */ 1838 if (!nostdlib) 1839 return (hints[0] != '\0' ? hints : NULL); 1840 if (filtered_path != NULL) 1841 goto filt_ret; 1842 1843 /* 1844 * Obtain the list of all configured search paths, and the 1845 * list of the default paths. 1846 * 1847 * First estimate the size of the results. 1848 */ 1849 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1850 smeta.dls_cnt = 0; 1851 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1852 hmeta.dls_cnt = 0; 1853 1854 sargs.request = RTLD_DI_SERINFOSIZE; 1855 sargs.serinfo = &smeta; 1856 hargs.request = RTLD_DI_SERINFOSIZE; 1857 hargs.serinfo = &hmeta; 1858 1859 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1860 &sargs); 1861 path_enumerate(hints, fill_search_info, NULL, &hargs); 1862 1863 SLPinfo = xmalloc(smeta.dls_size); 1864 hintinfo = xmalloc(hmeta.dls_size); 1865 1866 /* 1867 * Next fetch both sets of paths. 1868 */ 1869 sargs.request = RTLD_DI_SERINFO; 1870 sargs.serinfo = SLPinfo; 1871 sargs.serpath = &SLPinfo->dls_serpath[0]; 1872 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1873 1874 hargs.request = RTLD_DI_SERINFO; 1875 hargs.serinfo = hintinfo; 1876 hargs.serpath = &hintinfo->dls_serpath[0]; 1877 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1878 1879 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1880 &sargs); 1881 path_enumerate(hints, fill_search_info, NULL, &hargs); 1882 1883 /* 1884 * Now calculate the difference between two sets, by excluding 1885 * standard paths from the full set. 1886 */ 1887 fndx = 0; 1888 fcount = 0; 1889 filtered_path = xmalloc(hdr.dirlistlen + 1); 1890 hintpath = &hintinfo->dls_serpath[0]; 1891 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1892 skip = false; 1893 SLPpath = &SLPinfo->dls_serpath[0]; 1894 /* 1895 * Check each standard path against current. 1896 */ 1897 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1898 /* matched, skip the path */ 1899 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1900 skip = true; 1901 break; 1902 } 1903 } 1904 if (skip) 1905 continue; 1906 /* 1907 * Not matched against any standard path, add the path 1908 * to result. Separate consequtive paths with ':'. 1909 */ 1910 if (fcount > 0) { 1911 filtered_path[fndx] = ':'; 1912 fndx++; 1913 } 1914 fcount++; 1915 flen = strlen(hintpath->dls_name); 1916 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1917 fndx += flen; 1918 } 1919 filtered_path[fndx] = '\0'; 1920 1921 free(SLPinfo); 1922 free(hintinfo); 1923 1924 filt_ret: 1925 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1926 } 1927 1928 static void 1929 init_dag(Obj_Entry *root) 1930 { 1931 const Needed_Entry *needed; 1932 const Objlist_Entry *elm; 1933 DoneList donelist; 1934 1935 if (root->dag_inited) 1936 return; 1937 donelist_init(&donelist); 1938 1939 /* Root object belongs to own DAG. */ 1940 objlist_push_tail(&root->dldags, root); 1941 objlist_push_tail(&root->dagmembers, root); 1942 donelist_check(&donelist, root); 1943 1944 /* 1945 * Add dependencies of root object to DAG in breadth order 1946 * by exploiting the fact that each new object get added 1947 * to the tail of the dagmembers list. 1948 */ 1949 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1950 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1951 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1952 continue; 1953 objlist_push_tail(&needed->obj->dldags, root); 1954 objlist_push_tail(&root->dagmembers, needed->obj); 1955 } 1956 } 1957 root->dag_inited = true; 1958 } 1959 1960 static void 1961 init_marker(Obj_Entry *marker) 1962 { 1963 1964 bzero(marker, sizeof(*marker)); 1965 marker->marker = true; 1966 } 1967 1968 Obj_Entry * 1969 globallist_curr(const Obj_Entry *obj) 1970 { 1971 1972 for (;;) { 1973 if (obj == NULL) 1974 return (NULL); 1975 if (!obj->marker) 1976 return (__DECONST(Obj_Entry *, obj)); 1977 obj = TAILQ_PREV(obj, obj_entry_q, next); 1978 } 1979 } 1980 1981 Obj_Entry * 1982 globallist_next(const Obj_Entry *obj) 1983 { 1984 1985 for (;;) { 1986 obj = TAILQ_NEXT(obj, next); 1987 if (obj == NULL) 1988 return (NULL); 1989 if (!obj->marker) 1990 return (__DECONST(Obj_Entry *, obj)); 1991 } 1992 } 1993 1994 /* Prevent the object from being unmapped while the bind lock is dropped. */ 1995 static void 1996 hold_object(Obj_Entry *obj) 1997 { 1998 1999 obj->holdcount++; 2000 } 2001 2002 static void 2003 unhold_object(Obj_Entry *obj) 2004 { 2005 2006 assert(obj->holdcount > 0); 2007 if (--obj->holdcount == 0 && obj->unholdfree) 2008 release_object(obj); 2009 } 2010 2011 static void 2012 process_z(Obj_Entry *root) 2013 { 2014 const Objlist_Entry *elm; 2015 Obj_Entry *obj; 2016 2017 /* 2018 * Walk over object DAG and process every dependent object 2019 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2020 * to grow their own DAG. 2021 * 2022 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2023 * symlook_global() to work. 2024 * 2025 * For DF_1_NODELETE, the DAG should have its reference upped. 2026 */ 2027 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2028 obj = elm->obj; 2029 if (obj == NULL) 2030 continue; 2031 if (obj->z_nodelete && !obj->ref_nodel) { 2032 dbg("obj %s -z nodelete", obj->path); 2033 init_dag(obj); 2034 ref_dag(obj); 2035 obj->ref_nodel = true; 2036 } 2037 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2038 dbg("obj %s -z global", obj->path); 2039 objlist_push_tail(&list_global, obj); 2040 init_dag(obj); 2041 } 2042 } 2043 } 2044 /* 2045 * Initialize the dynamic linker. The argument is the address at which 2046 * the dynamic linker has been mapped into memory. The primary task of 2047 * this function is to relocate the dynamic linker. 2048 */ 2049 static void 2050 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2051 { 2052 Obj_Entry objtmp; /* Temporary rtld object */ 2053 const Elf_Ehdr *ehdr; 2054 const Elf_Dyn *dyn_rpath; 2055 const Elf_Dyn *dyn_soname; 2056 const Elf_Dyn *dyn_runpath; 2057 2058 #ifdef RTLD_INIT_PAGESIZES_EARLY 2059 /* The page size is required by the dynamic memory allocator. */ 2060 init_pagesizes(aux_info); 2061 #endif 2062 2063 /* 2064 * Conjure up an Obj_Entry structure for the dynamic linker. 2065 * 2066 * The "path" member can't be initialized yet because string constants 2067 * cannot yet be accessed. Below we will set it correctly. 2068 */ 2069 memset(&objtmp, 0, sizeof(objtmp)); 2070 objtmp.path = NULL; 2071 objtmp.rtld = true; 2072 objtmp.mapbase = mapbase; 2073 #ifdef PIC 2074 objtmp.relocbase = mapbase; 2075 #endif 2076 2077 objtmp.dynamic = rtld_dynamic(&objtmp); 2078 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2079 assert(objtmp.needed == NULL); 2080 #if !defined(__mips__) 2081 /* MIPS has a bogus DT_TEXTREL. */ 2082 assert(!objtmp.textrel); 2083 #endif 2084 /* 2085 * Temporarily put the dynamic linker entry into the object list, so 2086 * that symbols can be found. 2087 */ 2088 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2089 2090 ehdr = (Elf_Ehdr *)mapbase; 2091 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2092 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2093 2094 /* Initialize the object list. */ 2095 TAILQ_INIT(&obj_list); 2096 2097 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2098 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2099 2100 #ifndef RTLD_INIT_PAGESIZES_EARLY 2101 /* The page size is required by the dynamic memory allocator. */ 2102 init_pagesizes(aux_info); 2103 #endif 2104 2105 if (aux_info[AT_OSRELDATE] != NULL) 2106 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2107 2108 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2109 2110 /* Replace the path with a dynamically allocated copy. */ 2111 obj_rtld.path = xstrdup(ld_path_rtld); 2112 2113 r_debug.r_brk = r_debug_state; 2114 r_debug.r_state = RT_CONSISTENT; 2115 } 2116 2117 /* 2118 * Retrieve the array of supported page sizes. The kernel provides the page 2119 * sizes in increasing order. 2120 */ 2121 static void 2122 init_pagesizes(Elf_Auxinfo **aux_info) 2123 { 2124 static size_t psa[MAXPAGESIZES]; 2125 int mib[2]; 2126 size_t len, size; 2127 2128 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2129 NULL) { 2130 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2131 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2132 } else { 2133 len = 2; 2134 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2135 size = sizeof(psa); 2136 else { 2137 /* As a fallback, retrieve the base page size. */ 2138 size = sizeof(psa[0]); 2139 if (aux_info[AT_PAGESZ] != NULL) { 2140 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2141 goto psa_filled; 2142 } else { 2143 mib[0] = CTL_HW; 2144 mib[1] = HW_PAGESIZE; 2145 len = 2; 2146 } 2147 } 2148 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2149 _rtld_error("sysctl for hw.pagesize(s) failed"); 2150 rtld_die(); 2151 } 2152 psa_filled: 2153 pagesizes = psa; 2154 } 2155 npagesizes = size / sizeof(pagesizes[0]); 2156 /* Discard any invalid entries at the end of the array. */ 2157 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2158 npagesizes--; 2159 } 2160 2161 /* 2162 * Add the init functions from a needed object list (and its recursive 2163 * needed objects) to "list". This is not used directly; it is a helper 2164 * function for initlist_add_objects(). The write lock must be held 2165 * when this function is called. 2166 */ 2167 static void 2168 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2169 { 2170 /* Recursively process the successor needed objects. */ 2171 if (needed->next != NULL) 2172 initlist_add_neededs(needed->next, list); 2173 2174 /* Process the current needed object. */ 2175 if (needed->obj != NULL) 2176 initlist_add_objects(needed->obj, needed->obj, list); 2177 } 2178 2179 /* 2180 * Scan all of the DAGs rooted in the range of objects from "obj" to 2181 * "tail" and add their init functions to "list". This recurses over 2182 * the DAGs and ensure the proper init ordering such that each object's 2183 * needed libraries are initialized before the object itself. At the 2184 * same time, this function adds the objects to the global finalization 2185 * list "list_fini" in the opposite order. The write lock must be 2186 * held when this function is called. 2187 */ 2188 static void 2189 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2190 { 2191 Obj_Entry *nobj; 2192 2193 if (obj->init_scanned || obj->init_done) 2194 return; 2195 obj->init_scanned = true; 2196 2197 /* Recursively process the successor objects. */ 2198 nobj = globallist_next(obj); 2199 if (nobj != NULL && obj != tail) 2200 initlist_add_objects(nobj, tail, list); 2201 2202 /* Recursively process the needed objects. */ 2203 if (obj->needed != NULL) 2204 initlist_add_neededs(obj->needed, list); 2205 if (obj->needed_filtees != NULL) 2206 initlist_add_neededs(obj->needed_filtees, list); 2207 if (obj->needed_aux_filtees != NULL) 2208 initlist_add_neededs(obj->needed_aux_filtees, list); 2209 2210 /* Add the object to the init list. */ 2211 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 2212 obj->init_array != (Elf_Addr)NULL) 2213 objlist_push_tail(list, obj); 2214 2215 /* Add the object to the global fini list in the reverse order. */ 2216 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2217 && !obj->on_fini_list) { 2218 objlist_push_head(&list_fini, obj); 2219 obj->on_fini_list = true; 2220 } 2221 } 2222 2223 #ifndef FPTR_TARGET 2224 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2225 #endif 2226 2227 static void 2228 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2229 { 2230 Needed_Entry *needed, *needed1; 2231 2232 for (needed = n; needed != NULL; needed = needed->next) { 2233 if (needed->obj != NULL) { 2234 dlclose_locked(needed->obj, lockstate); 2235 needed->obj = NULL; 2236 } 2237 } 2238 for (needed = n; needed != NULL; needed = needed1) { 2239 needed1 = needed->next; 2240 free(needed); 2241 } 2242 } 2243 2244 static void 2245 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2246 { 2247 2248 free_needed_filtees(obj->needed_filtees, lockstate); 2249 obj->needed_filtees = NULL; 2250 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2251 obj->needed_aux_filtees = NULL; 2252 obj->filtees_loaded = false; 2253 } 2254 2255 static void 2256 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2257 RtldLockState *lockstate) 2258 { 2259 2260 for (; needed != NULL; needed = needed->next) { 2261 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2262 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2263 RTLD_LOCAL, lockstate); 2264 } 2265 } 2266 2267 static void 2268 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2269 { 2270 2271 lock_restart_for_upgrade(lockstate); 2272 if (!obj->filtees_loaded) { 2273 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2274 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2275 obj->filtees_loaded = true; 2276 } 2277 } 2278 2279 static int 2280 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2281 { 2282 Obj_Entry *obj1; 2283 2284 for (; needed != NULL; needed = needed->next) { 2285 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2286 flags & ~RTLD_LO_NOLOAD); 2287 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2288 return (-1); 2289 } 2290 return (0); 2291 } 2292 2293 /* 2294 * Given a shared object, traverse its list of needed objects, and load 2295 * each of them. Returns 0 on success. Generates an error message and 2296 * returns -1 on failure. 2297 */ 2298 static int 2299 load_needed_objects(Obj_Entry *first, int flags) 2300 { 2301 Obj_Entry *obj; 2302 2303 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2304 if (obj->marker) 2305 continue; 2306 if (process_needed(obj, obj->needed, flags) == -1) 2307 return (-1); 2308 } 2309 return (0); 2310 } 2311 2312 static int 2313 load_preload_objects(void) 2314 { 2315 char *p = ld_preload; 2316 Obj_Entry *obj; 2317 static const char delim[] = " \t:;"; 2318 2319 if (p == NULL) 2320 return 0; 2321 2322 p += strspn(p, delim); 2323 while (*p != '\0') { 2324 size_t len = strcspn(p, delim); 2325 char savech; 2326 2327 savech = p[len]; 2328 p[len] = '\0'; 2329 obj = load_object(p, -1, NULL, 0); 2330 if (obj == NULL) 2331 return -1; /* XXX - cleanup */ 2332 obj->z_interpose = true; 2333 p[len] = savech; 2334 p += len; 2335 p += strspn(p, delim); 2336 } 2337 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2338 return 0; 2339 } 2340 2341 static const char * 2342 printable_path(const char *path) 2343 { 2344 2345 return (path == NULL ? "<unknown>" : path); 2346 } 2347 2348 /* 2349 * Load a shared object into memory, if it is not already loaded. The 2350 * object may be specified by name or by user-supplied file descriptor 2351 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2352 * duplicate is. 2353 * 2354 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2355 * on failure. 2356 */ 2357 static Obj_Entry * 2358 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2359 { 2360 Obj_Entry *obj; 2361 int fd; 2362 struct stat sb; 2363 char *path; 2364 2365 fd = -1; 2366 if (name != NULL) { 2367 TAILQ_FOREACH(obj, &obj_list, next) { 2368 if (obj->marker || obj->doomed) 2369 continue; 2370 if (object_match_name(obj, name)) 2371 return (obj); 2372 } 2373 2374 path = find_library(name, refobj, &fd); 2375 if (path == NULL) 2376 return (NULL); 2377 } else 2378 path = NULL; 2379 2380 if (fd >= 0) { 2381 /* 2382 * search_library_pathfds() opens a fresh file descriptor for the 2383 * library, so there is no need to dup(). 2384 */ 2385 } else if (fd_u == -1) { 2386 /* 2387 * If we didn't find a match by pathname, or the name is not 2388 * supplied, open the file and check again by device and inode. 2389 * This avoids false mismatches caused by multiple links or ".." 2390 * in pathnames. 2391 * 2392 * To avoid a race, we open the file and use fstat() rather than 2393 * using stat(). 2394 */ 2395 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2396 _rtld_error("Cannot open \"%s\"", path); 2397 free(path); 2398 return (NULL); 2399 } 2400 } else { 2401 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2402 if (fd == -1) { 2403 _rtld_error("Cannot dup fd"); 2404 free(path); 2405 return (NULL); 2406 } 2407 } 2408 if (fstat(fd, &sb) == -1) { 2409 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2410 close(fd); 2411 free(path); 2412 return NULL; 2413 } 2414 TAILQ_FOREACH(obj, &obj_list, next) { 2415 if (obj->marker || obj->doomed) 2416 continue; 2417 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2418 break; 2419 } 2420 if (obj != NULL && name != NULL) { 2421 object_add_name(obj, name); 2422 free(path); 2423 close(fd); 2424 return obj; 2425 } 2426 if (flags & RTLD_LO_NOLOAD) { 2427 free(path); 2428 close(fd); 2429 return (NULL); 2430 } 2431 2432 /* First use of this object, so we must map it in */ 2433 obj = do_load_object(fd, name, path, &sb, flags); 2434 if (obj == NULL) 2435 free(path); 2436 close(fd); 2437 2438 return obj; 2439 } 2440 2441 static Obj_Entry * 2442 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2443 int flags) 2444 { 2445 Obj_Entry *obj; 2446 struct statfs fs; 2447 2448 /* 2449 * but first, make sure that environment variables haven't been 2450 * used to circumvent the noexec flag on a filesystem. 2451 */ 2452 if (dangerous_ld_env) { 2453 if (fstatfs(fd, &fs) != 0) { 2454 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2455 return NULL; 2456 } 2457 if (fs.f_flags & MNT_NOEXEC) { 2458 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2459 return NULL; 2460 } 2461 } 2462 dbg("loading \"%s\"", printable_path(path)); 2463 obj = map_object(fd, printable_path(path), sbp); 2464 if (obj == NULL) 2465 return NULL; 2466 2467 /* 2468 * If DT_SONAME is present in the object, digest_dynamic2 already 2469 * added it to the object names. 2470 */ 2471 if (name != NULL) 2472 object_add_name(obj, name); 2473 obj->path = path; 2474 digest_dynamic(obj, 0); 2475 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2476 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2477 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2478 RTLD_LO_DLOPEN) { 2479 dbg("refusing to load non-loadable \"%s\"", obj->path); 2480 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2481 munmap(obj->mapbase, obj->mapsize); 2482 obj_free(obj); 2483 return (NULL); 2484 } 2485 2486 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2487 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2488 obj_count++; 2489 obj_loads++; 2490 linkmap_add(obj); /* for GDB & dlinfo() */ 2491 max_stack_flags |= obj->stack_flags; 2492 2493 dbg(" %p .. %p: %s", obj->mapbase, 2494 obj->mapbase + obj->mapsize - 1, obj->path); 2495 if (obj->textrel) 2496 dbg(" WARNING: %s has impure text", obj->path); 2497 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2498 obj->path); 2499 2500 return obj; 2501 } 2502 2503 static Obj_Entry * 2504 obj_from_addr(const void *addr) 2505 { 2506 Obj_Entry *obj; 2507 2508 TAILQ_FOREACH(obj, &obj_list, next) { 2509 if (obj->marker) 2510 continue; 2511 if (addr < (void *) obj->mapbase) 2512 continue; 2513 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2514 return obj; 2515 } 2516 return NULL; 2517 } 2518 2519 static void 2520 preinit_main(void) 2521 { 2522 Elf_Addr *preinit_addr; 2523 int index; 2524 2525 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2526 if (preinit_addr == NULL) 2527 return; 2528 2529 for (index = 0; index < obj_main->preinit_array_num; index++) { 2530 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2531 dbg("calling preinit function for %s at %p", obj_main->path, 2532 (void *)preinit_addr[index]); 2533 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2534 0, 0, obj_main->path); 2535 call_init_pointer(obj_main, preinit_addr[index]); 2536 } 2537 } 2538 } 2539 2540 /* 2541 * Call the finalization functions for each of the objects in "list" 2542 * belonging to the DAG of "root" and referenced once. If NULL "root" 2543 * is specified, every finalization function will be called regardless 2544 * of the reference count and the list elements won't be freed. All of 2545 * the objects are expected to have non-NULL fini functions. 2546 */ 2547 static void 2548 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2549 { 2550 Objlist_Entry *elm; 2551 char *saved_msg; 2552 Elf_Addr *fini_addr; 2553 int index; 2554 2555 assert(root == NULL || root->refcount == 1); 2556 2557 if (root != NULL) 2558 root->doomed = true; 2559 2560 /* 2561 * Preserve the current error message since a fini function might 2562 * call into the dynamic linker and overwrite it. 2563 */ 2564 saved_msg = errmsg_save(); 2565 do { 2566 STAILQ_FOREACH(elm, list, link) { 2567 if (root != NULL && (elm->obj->refcount != 1 || 2568 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2569 continue; 2570 /* Remove object from fini list to prevent recursive invocation. */ 2571 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2572 /* Ensure that new references cannot be acquired. */ 2573 elm->obj->doomed = true; 2574 2575 hold_object(elm->obj); 2576 lock_release(rtld_bind_lock, lockstate); 2577 /* 2578 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2579 * When this happens, DT_FINI_ARRAY is processed first. 2580 */ 2581 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2582 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2583 for (index = elm->obj->fini_array_num - 1; index >= 0; 2584 index--) { 2585 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2586 dbg("calling fini function for %s at %p", 2587 elm->obj->path, (void *)fini_addr[index]); 2588 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2589 (void *)fini_addr[index], 0, 0, elm->obj->path); 2590 call_initfini_pointer(elm->obj, fini_addr[index]); 2591 } 2592 } 2593 } 2594 if (elm->obj->fini != (Elf_Addr)NULL) { 2595 dbg("calling fini function for %s at %p", elm->obj->path, 2596 (void *)elm->obj->fini); 2597 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2598 0, 0, elm->obj->path); 2599 call_initfini_pointer(elm->obj, elm->obj->fini); 2600 } 2601 wlock_acquire(rtld_bind_lock, lockstate); 2602 unhold_object(elm->obj); 2603 /* No need to free anything if process is going down. */ 2604 if (root != NULL) 2605 free(elm); 2606 /* 2607 * We must restart the list traversal after every fini call 2608 * because a dlclose() call from the fini function or from 2609 * another thread might have modified the reference counts. 2610 */ 2611 break; 2612 } 2613 } while (elm != NULL); 2614 errmsg_restore(saved_msg); 2615 } 2616 2617 /* 2618 * Call the initialization functions for each of the objects in 2619 * "list". All of the objects are expected to have non-NULL init 2620 * functions. 2621 */ 2622 static void 2623 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2624 { 2625 Objlist_Entry *elm; 2626 Obj_Entry *obj; 2627 char *saved_msg; 2628 Elf_Addr *init_addr; 2629 int index; 2630 2631 /* 2632 * Clean init_scanned flag so that objects can be rechecked and 2633 * possibly initialized earlier if any of vectors called below 2634 * cause the change by using dlopen. 2635 */ 2636 TAILQ_FOREACH(obj, &obj_list, next) { 2637 if (obj->marker) 2638 continue; 2639 obj->init_scanned = false; 2640 } 2641 2642 /* 2643 * Preserve the current error message since an init function might 2644 * call into the dynamic linker and overwrite it. 2645 */ 2646 saved_msg = errmsg_save(); 2647 STAILQ_FOREACH(elm, list, link) { 2648 if (elm->obj->init_done) /* Initialized early. */ 2649 continue; 2650 /* 2651 * Race: other thread might try to use this object before current 2652 * one completes the initialization. Not much can be done here 2653 * without better locking. 2654 */ 2655 elm->obj->init_done = true; 2656 hold_object(elm->obj); 2657 lock_release(rtld_bind_lock, lockstate); 2658 2659 /* 2660 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2661 * When this happens, DT_INIT is processed first. 2662 */ 2663 if (elm->obj->init != (Elf_Addr)NULL) { 2664 dbg("calling init function for %s at %p", elm->obj->path, 2665 (void *)elm->obj->init); 2666 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2667 0, 0, elm->obj->path); 2668 call_initfini_pointer(elm->obj, elm->obj->init); 2669 } 2670 init_addr = (Elf_Addr *)elm->obj->init_array; 2671 if (init_addr != NULL) { 2672 for (index = 0; index < elm->obj->init_array_num; index++) { 2673 if (init_addr[index] != 0 && init_addr[index] != 1) { 2674 dbg("calling init function for %s at %p", elm->obj->path, 2675 (void *)init_addr[index]); 2676 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2677 (void *)init_addr[index], 0, 0, elm->obj->path); 2678 call_init_pointer(elm->obj, init_addr[index]); 2679 } 2680 } 2681 } 2682 wlock_acquire(rtld_bind_lock, lockstate); 2683 unhold_object(elm->obj); 2684 } 2685 errmsg_restore(saved_msg); 2686 } 2687 2688 static void 2689 objlist_clear(Objlist *list) 2690 { 2691 Objlist_Entry *elm; 2692 2693 while (!STAILQ_EMPTY(list)) { 2694 elm = STAILQ_FIRST(list); 2695 STAILQ_REMOVE_HEAD(list, link); 2696 free(elm); 2697 } 2698 } 2699 2700 static Objlist_Entry * 2701 objlist_find(Objlist *list, const Obj_Entry *obj) 2702 { 2703 Objlist_Entry *elm; 2704 2705 STAILQ_FOREACH(elm, list, link) 2706 if (elm->obj == obj) 2707 return elm; 2708 return NULL; 2709 } 2710 2711 static void 2712 objlist_init(Objlist *list) 2713 { 2714 STAILQ_INIT(list); 2715 } 2716 2717 static void 2718 objlist_push_head(Objlist *list, Obj_Entry *obj) 2719 { 2720 Objlist_Entry *elm; 2721 2722 elm = NEW(Objlist_Entry); 2723 elm->obj = obj; 2724 STAILQ_INSERT_HEAD(list, elm, link); 2725 } 2726 2727 static void 2728 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2729 { 2730 Objlist_Entry *elm; 2731 2732 elm = NEW(Objlist_Entry); 2733 elm->obj = obj; 2734 STAILQ_INSERT_TAIL(list, elm, link); 2735 } 2736 2737 static void 2738 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2739 { 2740 Objlist_Entry *elm, *listelm; 2741 2742 STAILQ_FOREACH(listelm, list, link) { 2743 if (listelm->obj == listobj) 2744 break; 2745 } 2746 elm = NEW(Objlist_Entry); 2747 elm->obj = obj; 2748 if (listelm != NULL) 2749 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2750 else 2751 STAILQ_INSERT_TAIL(list, elm, link); 2752 } 2753 2754 static void 2755 objlist_remove(Objlist *list, Obj_Entry *obj) 2756 { 2757 Objlist_Entry *elm; 2758 2759 if ((elm = objlist_find(list, obj)) != NULL) { 2760 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2761 free(elm); 2762 } 2763 } 2764 2765 /* 2766 * Relocate dag rooted in the specified object. 2767 * Returns 0 on success, or -1 on failure. 2768 */ 2769 2770 static int 2771 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2772 int flags, RtldLockState *lockstate) 2773 { 2774 Objlist_Entry *elm; 2775 int error; 2776 2777 error = 0; 2778 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2779 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2780 lockstate); 2781 if (error == -1) 2782 break; 2783 } 2784 return (error); 2785 } 2786 2787 /* 2788 * Prepare for, or clean after, relocating an object marked with 2789 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 2790 * segments are remapped read-write. After relocations are done, the 2791 * segment's permissions are returned back to the modes specified in 2792 * the phdrs. If any relocation happened, or always for wired 2793 * program, COW is triggered. 2794 */ 2795 static int 2796 reloc_textrel_prot(Obj_Entry *obj, bool before) 2797 { 2798 const Elf_Phdr *ph; 2799 void *base; 2800 size_t l, sz; 2801 int prot; 2802 2803 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 2804 l--, ph++) { 2805 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 2806 continue; 2807 base = obj->relocbase + trunc_page(ph->p_vaddr); 2808 sz = round_page(ph->p_vaddr + ph->p_filesz) - 2809 trunc_page(ph->p_vaddr); 2810 prot = convert_prot(ph->p_flags) | (before ? PROT_WRITE : 0); 2811 if (mprotect(base, sz, prot) == -1) { 2812 _rtld_error("%s: Cannot write-%sable text segment: %s", 2813 obj->path, before ? "en" : "dis", 2814 rtld_strerror(errno)); 2815 return (-1); 2816 } 2817 } 2818 return (0); 2819 } 2820 2821 /* 2822 * Relocate single object. 2823 * Returns 0 on success, or -1 on failure. 2824 */ 2825 static int 2826 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2827 int flags, RtldLockState *lockstate) 2828 { 2829 2830 if (obj->relocated) 2831 return (0); 2832 obj->relocated = true; 2833 if (obj != rtldobj) 2834 dbg("relocating \"%s\"", obj->path); 2835 2836 if (obj->symtab == NULL || obj->strtab == NULL || 2837 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2838 _rtld_error("%s: Shared object has no run-time symbol table", 2839 obj->path); 2840 return (-1); 2841 } 2842 2843 /* There are relocations to the write-protected text segment. */ 2844 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 2845 return (-1); 2846 2847 /* Process the non-PLT non-IFUNC relocations. */ 2848 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2849 return (-1); 2850 2851 /* Re-protected the text segment. */ 2852 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 2853 return (-1); 2854 2855 /* Set the special PLT or GOT entries. */ 2856 init_pltgot(obj); 2857 2858 /* Process the PLT relocations. */ 2859 if (reloc_plt(obj) == -1) 2860 return (-1); 2861 /* Relocate the jump slots if we are doing immediate binding. */ 2862 if (obj->bind_now || bind_now) 2863 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2864 return (-1); 2865 2866 /* 2867 * Process the non-PLT IFUNC relocations. The relocations are 2868 * processed in two phases, because IFUNC resolvers may 2869 * reference other symbols, which must be readily processed 2870 * before resolvers are called. 2871 */ 2872 if (obj->non_plt_gnu_ifunc && 2873 reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate)) 2874 return (-1); 2875 2876 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 2877 return (-1); 2878 2879 /* 2880 * Set up the magic number and version in the Obj_Entry. These 2881 * were checked in the crt1.o from the original ElfKit, so we 2882 * set them for backward compatibility. 2883 */ 2884 obj->magic = RTLD_MAGIC; 2885 obj->version = RTLD_VERSION; 2886 2887 return (0); 2888 } 2889 2890 /* 2891 * Relocate newly-loaded shared objects. The argument is a pointer to 2892 * the Obj_Entry for the first such object. All objects from the first 2893 * to the end of the list of objects are relocated. Returns 0 on success, 2894 * or -1 on failure. 2895 */ 2896 static int 2897 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2898 int flags, RtldLockState *lockstate) 2899 { 2900 Obj_Entry *obj; 2901 int error; 2902 2903 for (error = 0, obj = first; obj != NULL; 2904 obj = TAILQ_NEXT(obj, next)) { 2905 if (obj->marker) 2906 continue; 2907 error = relocate_object(obj, bind_now, rtldobj, flags, 2908 lockstate); 2909 if (error == -1) 2910 break; 2911 } 2912 return (error); 2913 } 2914 2915 /* 2916 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2917 * referencing STT_GNU_IFUNC symbols is postponed till the other 2918 * relocations are done. The indirect functions specified as 2919 * ifunc are allowed to call other symbols, so we need to have 2920 * objects relocated before asking for resolution from indirects. 2921 * 2922 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2923 * instead of the usual lazy handling of PLT slots. It is 2924 * consistent with how GNU does it. 2925 */ 2926 static int 2927 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2928 RtldLockState *lockstate) 2929 { 2930 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2931 return (-1); 2932 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2933 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2934 return (-1); 2935 return (0); 2936 } 2937 2938 static int 2939 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2940 RtldLockState *lockstate) 2941 { 2942 Obj_Entry *obj; 2943 2944 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2945 if (obj->marker) 2946 continue; 2947 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2948 return (-1); 2949 } 2950 return (0); 2951 } 2952 2953 static int 2954 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2955 RtldLockState *lockstate) 2956 { 2957 Objlist_Entry *elm; 2958 2959 STAILQ_FOREACH(elm, list, link) { 2960 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2961 lockstate) == -1) 2962 return (-1); 2963 } 2964 return (0); 2965 } 2966 2967 /* 2968 * Cleanup procedure. It will be called (by the atexit mechanism) just 2969 * before the process exits. 2970 */ 2971 static void 2972 rtld_exit(void) 2973 { 2974 RtldLockState lockstate; 2975 2976 wlock_acquire(rtld_bind_lock, &lockstate); 2977 dbg("rtld_exit()"); 2978 objlist_call_fini(&list_fini, NULL, &lockstate); 2979 /* No need to remove the items from the list, since we are exiting. */ 2980 if (!libmap_disable) 2981 lm_fini(); 2982 lock_release(rtld_bind_lock, &lockstate); 2983 } 2984 2985 /* 2986 * Iterate over a search path, translate each element, and invoke the 2987 * callback on the result. 2988 */ 2989 static void * 2990 path_enumerate(const char *path, path_enum_proc callback, 2991 const char *refobj_path, void *arg) 2992 { 2993 const char *trans; 2994 if (path == NULL) 2995 return (NULL); 2996 2997 path += strspn(path, ":;"); 2998 while (*path != '\0') { 2999 size_t len; 3000 char *res; 3001 3002 len = strcspn(path, ":;"); 3003 trans = lm_findn(refobj_path, path, len); 3004 if (trans) 3005 res = callback(trans, strlen(trans), arg); 3006 else 3007 res = callback(path, len, arg); 3008 3009 if (res != NULL) 3010 return (res); 3011 3012 path += len; 3013 path += strspn(path, ":;"); 3014 } 3015 3016 return (NULL); 3017 } 3018 3019 struct try_library_args { 3020 const char *name; 3021 size_t namelen; 3022 char *buffer; 3023 size_t buflen; 3024 int fd; 3025 }; 3026 3027 static void * 3028 try_library_path(const char *dir, size_t dirlen, void *param) 3029 { 3030 struct try_library_args *arg; 3031 int fd; 3032 3033 arg = param; 3034 if (*dir == '/' || trust) { 3035 char *pathname; 3036 3037 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3038 return (NULL); 3039 3040 pathname = arg->buffer; 3041 strncpy(pathname, dir, dirlen); 3042 pathname[dirlen] = '/'; 3043 strcpy(pathname + dirlen + 1, arg->name); 3044 3045 dbg(" Trying \"%s\"", pathname); 3046 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3047 if (fd >= 0) { 3048 dbg(" Opened \"%s\", fd %d", pathname, fd); 3049 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3050 strcpy(pathname, arg->buffer); 3051 arg->fd = fd; 3052 return (pathname); 3053 } else { 3054 dbg(" Failed to open \"%s\": %s", 3055 pathname, rtld_strerror(errno)); 3056 } 3057 } 3058 return (NULL); 3059 } 3060 3061 static char * 3062 search_library_path(const char *name, const char *path, 3063 const char *refobj_path, int *fdp) 3064 { 3065 char *p; 3066 struct try_library_args arg; 3067 3068 if (path == NULL) 3069 return NULL; 3070 3071 arg.name = name; 3072 arg.namelen = strlen(name); 3073 arg.buffer = xmalloc(PATH_MAX); 3074 arg.buflen = PATH_MAX; 3075 arg.fd = -1; 3076 3077 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3078 *fdp = arg.fd; 3079 3080 free(arg.buffer); 3081 3082 return (p); 3083 } 3084 3085 3086 /* 3087 * Finds the library with the given name using the directory descriptors 3088 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3089 * 3090 * Returns a freshly-opened close-on-exec file descriptor for the library, 3091 * or -1 if the library cannot be found. 3092 */ 3093 static char * 3094 search_library_pathfds(const char *name, const char *path, int *fdp) 3095 { 3096 char *envcopy, *fdstr, *found, *last_token; 3097 size_t len; 3098 int dirfd, fd; 3099 3100 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3101 3102 /* Don't load from user-specified libdirs into setuid binaries. */ 3103 if (!trust) 3104 return (NULL); 3105 3106 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3107 if (path == NULL) 3108 return (NULL); 3109 3110 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3111 if (name[0] == '/') { 3112 dbg("Absolute path (%s) passed to %s", name, __func__); 3113 return (NULL); 3114 } 3115 3116 /* 3117 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3118 * copy of the path, as strtok_r rewrites separator tokens 3119 * with '\0'. 3120 */ 3121 found = NULL; 3122 envcopy = xstrdup(path); 3123 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3124 fdstr = strtok_r(NULL, ":", &last_token)) { 3125 dirfd = parse_integer(fdstr); 3126 if (dirfd < 0) { 3127 _rtld_error("failed to parse directory FD: '%s'", 3128 fdstr); 3129 break; 3130 } 3131 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3132 if (fd >= 0) { 3133 *fdp = fd; 3134 len = strlen(fdstr) + strlen(name) + 3; 3135 found = xmalloc(len); 3136 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3137 _rtld_error("error generating '%d/%s'", 3138 dirfd, name); 3139 rtld_die(); 3140 } 3141 dbg("open('%s') => %d", found, fd); 3142 break; 3143 } 3144 } 3145 free(envcopy); 3146 3147 return (found); 3148 } 3149 3150 3151 int 3152 dlclose(void *handle) 3153 { 3154 RtldLockState lockstate; 3155 int error; 3156 3157 wlock_acquire(rtld_bind_lock, &lockstate); 3158 error = dlclose_locked(handle, &lockstate); 3159 lock_release(rtld_bind_lock, &lockstate); 3160 return (error); 3161 } 3162 3163 static int 3164 dlclose_locked(void *handle, RtldLockState *lockstate) 3165 { 3166 Obj_Entry *root; 3167 3168 root = dlcheck(handle); 3169 if (root == NULL) 3170 return -1; 3171 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3172 root->path); 3173 3174 /* Unreference the object and its dependencies. */ 3175 root->dl_refcount--; 3176 3177 if (root->refcount == 1) { 3178 /* 3179 * The object will be no longer referenced, so we must unload it. 3180 * First, call the fini functions. 3181 */ 3182 objlist_call_fini(&list_fini, root, lockstate); 3183 3184 unref_dag(root); 3185 3186 /* Finish cleaning up the newly-unreferenced objects. */ 3187 GDB_STATE(RT_DELETE,&root->linkmap); 3188 unload_object(root, lockstate); 3189 GDB_STATE(RT_CONSISTENT,NULL); 3190 } else 3191 unref_dag(root); 3192 3193 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3194 return 0; 3195 } 3196 3197 char * 3198 dlerror(void) 3199 { 3200 char *msg = error_message; 3201 error_message = NULL; 3202 return msg; 3203 } 3204 3205 /* 3206 * This function is deprecated and has no effect. 3207 */ 3208 void 3209 dllockinit(void *context, 3210 void *(*lock_create)(void *context), 3211 void (*rlock_acquire)(void *lock), 3212 void (*wlock_acquire)(void *lock), 3213 void (*lock_release)(void *lock), 3214 void (*lock_destroy)(void *lock), 3215 void (*context_destroy)(void *context)) 3216 { 3217 static void *cur_context; 3218 static void (*cur_context_destroy)(void *); 3219 3220 /* Just destroy the context from the previous call, if necessary. */ 3221 if (cur_context_destroy != NULL) 3222 cur_context_destroy(cur_context); 3223 cur_context = context; 3224 cur_context_destroy = context_destroy; 3225 } 3226 3227 void * 3228 dlopen(const char *name, int mode) 3229 { 3230 3231 return (rtld_dlopen(name, -1, mode)); 3232 } 3233 3234 void * 3235 fdlopen(int fd, int mode) 3236 { 3237 3238 return (rtld_dlopen(NULL, fd, mode)); 3239 } 3240 3241 static void * 3242 rtld_dlopen(const char *name, int fd, int mode) 3243 { 3244 RtldLockState lockstate; 3245 int lo_flags; 3246 3247 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3248 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3249 if (ld_tracing != NULL) { 3250 rlock_acquire(rtld_bind_lock, &lockstate); 3251 if (sigsetjmp(lockstate.env, 0) != 0) 3252 lock_upgrade(rtld_bind_lock, &lockstate); 3253 environ = (char **)*get_program_var_addr("environ", &lockstate); 3254 lock_release(rtld_bind_lock, &lockstate); 3255 } 3256 lo_flags = RTLD_LO_DLOPEN; 3257 if (mode & RTLD_NODELETE) 3258 lo_flags |= RTLD_LO_NODELETE; 3259 if (mode & RTLD_NOLOAD) 3260 lo_flags |= RTLD_LO_NOLOAD; 3261 if (ld_tracing != NULL) 3262 lo_flags |= RTLD_LO_TRACE; 3263 3264 return (dlopen_object(name, fd, obj_main, lo_flags, 3265 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3266 } 3267 3268 static void 3269 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3270 { 3271 3272 obj->dl_refcount--; 3273 unref_dag(obj); 3274 if (obj->refcount == 0) 3275 unload_object(obj, lockstate); 3276 } 3277 3278 static Obj_Entry * 3279 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3280 int mode, RtldLockState *lockstate) 3281 { 3282 Obj_Entry *old_obj_tail; 3283 Obj_Entry *obj; 3284 Objlist initlist; 3285 RtldLockState mlockstate; 3286 int result; 3287 3288 objlist_init(&initlist); 3289 3290 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3291 wlock_acquire(rtld_bind_lock, &mlockstate); 3292 lockstate = &mlockstate; 3293 } 3294 GDB_STATE(RT_ADD,NULL); 3295 3296 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3297 obj = NULL; 3298 if (name == NULL && fd == -1) { 3299 obj = obj_main; 3300 obj->refcount++; 3301 } else { 3302 obj = load_object(name, fd, refobj, lo_flags); 3303 } 3304 3305 if (obj) { 3306 obj->dl_refcount++; 3307 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3308 objlist_push_tail(&list_global, obj); 3309 if (globallist_next(old_obj_tail) != NULL) { 3310 /* We loaded something new. */ 3311 assert(globallist_next(old_obj_tail) == obj); 3312 result = load_needed_objects(obj, 3313 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 3314 init_dag(obj); 3315 ref_dag(obj); 3316 if (result != -1) 3317 result = rtld_verify_versions(&obj->dagmembers); 3318 if (result != -1 && ld_tracing) 3319 goto trace; 3320 if (result == -1 || relocate_object_dag(obj, 3321 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3322 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3323 lockstate) == -1) { 3324 dlopen_cleanup(obj, lockstate); 3325 obj = NULL; 3326 } else if (lo_flags & RTLD_LO_EARLY) { 3327 /* 3328 * Do not call the init functions for early loaded 3329 * filtees. The image is still not initialized enough 3330 * for them to work. 3331 * 3332 * Our object is found by the global object list and 3333 * will be ordered among all init calls done right 3334 * before transferring control to main. 3335 */ 3336 } else { 3337 /* Make list of init functions to call. */ 3338 initlist_add_objects(obj, obj, &initlist); 3339 } 3340 /* 3341 * Process all no_delete or global objects here, given 3342 * them own DAGs to prevent their dependencies from being 3343 * unloaded. This has to be done after we have loaded all 3344 * of the dependencies, so that we do not miss any. 3345 */ 3346 if (obj != NULL) 3347 process_z(obj); 3348 } else { 3349 /* 3350 * Bump the reference counts for objects on this DAG. If 3351 * this is the first dlopen() call for the object that was 3352 * already loaded as a dependency, initialize the dag 3353 * starting at it. 3354 */ 3355 init_dag(obj); 3356 ref_dag(obj); 3357 3358 if ((lo_flags & RTLD_LO_TRACE) != 0) 3359 goto trace; 3360 } 3361 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3362 obj->z_nodelete) && !obj->ref_nodel) { 3363 dbg("obj %s nodelete", obj->path); 3364 ref_dag(obj); 3365 obj->z_nodelete = obj->ref_nodel = true; 3366 } 3367 } 3368 3369 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3370 name); 3371 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3372 3373 if (!(lo_flags & RTLD_LO_EARLY)) { 3374 map_stacks_exec(lockstate); 3375 } 3376 3377 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3378 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3379 lockstate) == -1) { 3380 objlist_clear(&initlist); 3381 dlopen_cleanup(obj, lockstate); 3382 if (lockstate == &mlockstate) 3383 lock_release(rtld_bind_lock, lockstate); 3384 return (NULL); 3385 } 3386 3387 if (!(lo_flags & RTLD_LO_EARLY)) { 3388 /* Call the init functions. */ 3389 objlist_call_init(&initlist, lockstate); 3390 } 3391 objlist_clear(&initlist); 3392 if (lockstate == &mlockstate) 3393 lock_release(rtld_bind_lock, lockstate); 3394 return obj; 3395 trace: 3396 trace_loaded_objects(obj); 3397 if (lockstate == &mlockstate) 3398 lock_release(rtld_bind_lock, lockstate); 3399 exit(0); 3400 } 3401 3402 static void * 3403 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3404 int flags) 3405 { 3406 DoneList donelist; 3407 const Obj_Entry *obj, *defobj; 3408 const Elf_Sym *def; 3409 SymLook req; 3410 RtldLockState lockstate; 3411 tls_index ti; 3412 void *sym; 3413 int res; 3414 3415 def = NULL; 3416 defobj = NULL; 3417 symlook_init(&req, name); 3418 req.ventry = ve; 3419 req.flags = flags | SYMLOOK_IN_PLT; 3420 req.lockstate = &lockstate; 3421 3422 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3423 rlock_acquire(rtld_bind_lock, &lockstate); 3424 if (sigsetjmp(lockstate.env, 0) != 0) 3425 lock_upgrade(rtld_bind_lock, &lockstate); 3426 if (handle == NULL || handle == RTLD_NEXT || 3427 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3428 3429 if ((obj = obj_from_addr(retaddr)) == NULL) { 3430 _rtld_error("Cannot determine caller's shared object"); 3431 lock_release(rtld_bind_lock, &lockstate); 3432 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3433 return NULL; 3434 } 3435 if (handle == NULL) { /* Just the caller's shared object. */ 3436 res = symlook_obj(&req, obj); 3437 if (res == 0) { 3438 def = req.sym_out; 3439 defobj = req.defobj_out; 3440 } 3441 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3442 handle == RTLD_SELF) { /* ... caller included */ 3443 if (handle == RTLD_NEXT) 3444 obj = globallist_next(obj); 3445 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3446 if (obj->marker) 3447 continue; 3448 res = symlook_obj(&req, obj); 3449 if (res == 0) { 3450 if (def == NULL || 3451 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3452 def = req.sym_out; 3453 defobj = req.defobj_out; 3454 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3455 break; 3456 } 3457 } 3458 } 3459 /* 3460 * Search the dynamic linker itself, and possibly resolve the 3461 * symbol from there. This is how the application links to 3462 * dynamic linker services such as dlopen. 3463 */ 3464 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3465 res = symlook_obj(&req, &obj_rtld); 3466 if (res == 0) { 3467 def = req.sym_out; 3468 defobj = req.defobj_out; 3469 } 3470 } 3471 } else { 3472 assert(handle == RTLD_DEFAULT); 3473 res = symlook_default(&req, obj); 3474 if (res == 0) { 3475 defobj = req.defobj_out; 3476 def = req.sym_out; 3477 } 3478 } 3479 } else { 3480 if ((obj = dlcheck(handle)) == NULL) { 3481 lock_release(rtld_bind_lock, &lockstate); 3482 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3483 return NULL; 3484 } 3485 3486 donelist_init(&donelist); 3487 if (obj->mainprog) { 3488 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3489 res = symlook_global(&req, &donelist); 3490 if (res == 0) { 3491 def = req.sym_out; 3492 defobj = req.defobj_out; 3493 } 3494 /* 3495 * Search the dynamic linker itself, and possibly resolve the 3496 * symbol from there. This is how the application links to 3497 * dynamic linker services such as dlopen. 3498 */ 3499 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3500 res = symlook_obj(&req, &obj_rtld); 3501 if (res == 0) { 3502 def = req.sym_out; 3503 defobj = req.defobj_out; 3504 } 3505 } 3506 } 3507 else { 3508 /* Search the whole DAG rooted at the given object. */ 3509 res = symlook_list(&req, &obj->dagmembers, &donelist); 3510 if (res == 0) { 3511 def = req.sym_out; 3512 defobj = req.defobj_out; 3513 } 3514 } 3515 } 3516 3517 if (def != NULL) { 3518 lock_release(rtld_bind_lock, &lockstate); 3519 3520 /* 3521 * The value required by the caller is derived from the value 3522 * of the symbol. this is simply the relocated value of the 3523 * symbol. 3524 */ 3525 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3526 sym = make_function_pointer(def, defobj); 3527 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3528 sym = rtld_resolve_ifunc(defobj, def); 3529 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3530 ti.ti_module = defobj->tlsindex; 3531 ti.ti_offset = def->st_value; 3532 sym = __tls_get_addr(&ti); 3533 } else 3534 sym = defobj->relocbase + def->st_value; 3535 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3536 return (sym); 3537 } 3538 3539 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3540 ve != NULL ? ve->name : ""); 3541 lock_release(rtld_bind_lock, &lockstate); 3542 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3543 return NULL; 3544 } 3545 3546 void * 3547 dlsym(void *handle, const char *name) 3548 { 3549 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3550 SYMLOOK_DLSYM); 3551 } 3552 3553 dlfunc_t 3554 dlfunc(void *handle, const char *name) 3555 { 3556 union { 3557 void *d; 3558 dlfunc_t f; 3559 } rv; 3560 3561 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3562 SYMLOOK_DLSYM); 3563 return (rv.f); 3564 } 3565 3566 void * 3567 dlvsym(void *handle, const char *name, const char *version) 3568 { 3569 Ver_Entry ventry; 3570 3571 ventry.name = version; 3572 ventry.file = NULL; 3573 ventry.hash = elf_hash(version); 3574 ventry.flags= 0; 3575 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3576 SYMLOOK_DLSYM); 3577 } 3578 3579 int 3580 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3581 { 3582 const Obj_Entry *obj; 3583 RtldLockState lockstate; 3584 3585 rlock_acquire(rtld_bind_lock, &lockstate); 3586 obj = obj_from_addr(addr); 3587 if (obj == NULL) { 3588 _rtld_error("No shared object contains address"); 3589 lock_release(rtld_bind_lock, &lockstate); 3590 return (0); 3591 } 3592 rtld_fill_dl_phdr_info(obj, phdr_info); 3593 lock_release(rtld_bind_lock, &lockstate); 3594 return (1); 3595 } 3596 3597 int 3598 dladdr(const void *addr, Dl_info *info) 3599 { 3600 const Obj_Entry *obj; 3601 const Elf_Sym *def; 3602 void *symbol_addr; 3603 unsigned long symoffset; 3604 RtldLockState lockstate; 3605 3606 rlock_acquire(rtld_bind_lock, &lockstate); 3607 obj = obj_from_addr(addr); 3608 if (obj == NULL) { 3609 _rtld_error("No shared object contains address"); 3610 lock_release(rtld_bind_lock, &lockstate); 3611 return 0; 3612 } 3613 info->dli_fname = obj->path; 3614 info->dli_fbase = obj->mapbase; 3615 info->dli_saddr = (void *)0; 3616 info->dli_sname = NULL; 3617 3618 /* 3619 * Walk the symbol list looking for the symbol whose address is 3620 * closest to the address sent in. 3621 */ 3622 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3623 def = obj->symtab + symoffset; 3624 3625 /* 3626 * For skip the symbol if st_shndx is either SHN_UNDEF or 3627 * SHN_COMMON. 3628 */ 3629 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3630 continue; 3631 3632 /* 3633 * If the symbol is greater than the specified address, or if it 3634 * is further away from addr than the current nearest symbol, 3635 * then reject it. 3636 */ 3637 symbol_addr = obj->relocbase + def->st_value; 3638 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3639 continue; 3640 3641 /* Update our idea of the nearest symbol. */ 3642 info->dli_sname = obj->strtab + def->st_name; 3643 info->dli_saddr = symbol_addr; 3644 3645 /* Exact match? */ 3646 if (info->dli_saddr == addr) 3647 break; 3648 } 3649 lock_release(rtld_bind_lock, &lockstate); 3650 return 1; 3651 } 3652 3653 int 3654 dlinfo(void *handle, int request, void *p) 3655 { 3656 const Obj_Entry *obj; 3657 RtldLockState lockstate; 3658 int error; 3659 3660 rlock_acquire(rtld_bind_lock, &lockstate); 3661 3662 if (handle == NULL || handle == RTLD_SELF) { 3663 void *retaddr; 3664 3665 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3666 if ((obj = obj_from_addr(retaddr)) == NULL) 3667 _rtld_error("Cannot determine caller's shared object"); 3668 } else 3669 obj = dlcheck(handle); 3670 3671 if (obj == NULL) { 3672 lock_release(rtld_bind_lock, &lockstate); 3673 return (-1); 3674 } 3675 3676 error = 0; 3677 switch (request) { 3678 case RTLD_DI_LINKMAP: 3679 *((struct link_map const **)p) = &obj->linkmap; 3680 break; 3681 case RTLD_DI_ORIGIN: 3682 error = rtld_dirname(obj->path, p); 3683 break; 3684 3685 case RTLD_DI_SERINFOSIZE: 3686 case RTLD_DI_SERINFO: 3687 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3688 break; 3689 3690 default: 3691 _rtld_error("Invalid request %d passed to dlinfo()", request); 3692 error = -1; 3693 } 3694 3695 lock_release(rtld_bind_lock, &lockstate); 3696 3697 return (error); 3698 } 3699 3700 static void 3701 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3702 { 3703 3704 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3705 phdr_info->dlpi_name = obj->path; 3706 phdr_info->dlpi_phdr = obj->phdr; 3707 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3708 phdr_info->dlpi_tls_modid = obj->tlsindex; 3709 phdr_info->dlpi_tls_data = obj->tlsinit; 3710 phdr_info->dlpi_adds = obj_loads; 3711 phdr_info->dlpi_subs = obj_loads - obj_count; 3712 } 3713 3714 int 3715 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3716 { 3717 struct dl_phdr_info phdr_info; 3718 Obj_Entry *obj, marker; 3719 RtldLockState bind_lockstate, phdr_lockstate; 3720 int error; 3721 3722 init_marker(&marker); 3723 error = 0; 3724 3725 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3726 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3727 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3728 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3729 rtld_fill_dl_phdr_info(obj, &phdr_info); 3730 hold_object(obj); 3731 lock_release(rtld_bind_lock, &bind_lockstate); 3732 3733 error = callback(&phdr_info, sizeof phdr_info, param); 3734 3735 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3736 unhold_object(obj); 3737 obj = globallist_next(&marker); 3738 TAILQ_REMOVE(&obj_list, &marker, next); 3739 if (error != 0) { 3740 lock_release(rtld_bind_lock, &bind_lockstate); 3741 lock_release(rtld_phdr_lock, &phdr_lockstate); 3742 return (error); 3743 } 3744 } 3745 3746 if (error == 0) { 3747 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3748 lock_release(rtld_bind_lock, &bind_lockstate); 3749 error = callback(&phdr_info, sizeof(phdr_info), param); 3750 } 3751 lock_release(rtld_phdr_lock, &phdr_lockstate); 3752 return (error); 3753 } 3754 3755 static void * 3756 fill_search_info(const char *dir, size_t dirlen, void *param) 3757 { 3758 struct fill_search_info_args *arg; 3759 3760 arg = param; 3761 3762 if (arg->request == RTLD_DI_SERINFOSIZE) { 3763 arg->serinfo->dls_cnt ++; 3764 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3765 } else { 3766 struct dl_serpath *s_entry; 3767 3768 s_entry = arg->serpath; 3769 s_entry->dls_name = arg->strspace; 3770 s_entry->dls_flags = arg->flags; 3771 3772 strncpy(arg->strspace, dir, dirlen); 3773 arg->strspace[dirlen] = '\0'; 3774 3775 arg->strspace += dirlen + 1; 3776 arg->serpath++; 3777 } 3778 3779 return (NULL); 3780 } 3781 3782 static int 3783 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3784 { 3785 struct dl_serinfo _info; 3786 struct fill_search_info_args args; 3787 3788 args.request = RTLD_DI_SERINFOSIZE; 3789 args.serinfo = &_info; 3790 3791 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3792 _info.dls_cnt = 0; 3793 3794 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 3795 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 3796 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 3797 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 3798 if (!obj->z_nodeflib) 3799 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 3800 3801 3802 if (request == RTLD_DI_SERINFOSIZE) { 3803 info->dls_size = _info.dls_size; 3804 info->dls_cnt = _info.dls_cnt; 3805 return (0); 3806 } 3807 3808 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3809 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3810 return (-1); 3811 } 3812 3813 args.request = RTLD_DI_SERINFO; 3814 args.serinfo = info; 3815 args.serpath = &info->dls_serpath[0]; 3816 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3817 3818 args.flags = LA_SER_RUNPATH; 3819 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 3820 return (-1); 3821 3822 args.flags = LA_SER_LIBPATH; 3823 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 3824 return (-1); 3825 3826 args.flags = LA_SER_RUNPATH; 3827 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 3828 return (-1); 3829 3830 args.flags = LA_SER_CONFIG; 3831 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 3832 != NULL) 3833 return (-1); 3834 3835 args.flags = LA_SER_DEFAULT; 3836 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 3837 fill_search_info, NULL, &args) != NULL) 3838 return (-1); 3839 return (0); 3840 } 3841 3842 static int 3843 rtld_dirname(const char *path, char *bname) 3844 { 3845 const char *endp; 3846 3847 /* Empty or NULL string gets treated as "." */ 3848 if (path == NULL || *path == '\0') { 3849 bname[0] = '.'; 3850 bname[1] = '\0'; 3851 return (0); 3852 } 3853 3854 /* Strip trailing slashes */ 3855 endp = path + strlen(path) - 1; 3856 while (endp > path && *endp == '/') 3857 endp--; 3858 3859 /* Find the start of the dir */ 3860 while (endp > path && *endp != '/') 3861 endp--; 3862 3863 /* Either the dir is "/" or there are no slashes */ 3864 if (endp == path) { 3865 bname[0] = *endp == '/' ? '/' : '.'; 3866 bname[1] = '\0'; 3867 return (0); 3868 } else { 3869 do { 3870 endp--; 3871 } while (endp > path && *endp == '/'); 3872 } 3873 3874 if (endp - path + 2 > PATH_MAX) 3875 { 3876 _rtld_error("Filename is too long: %s", path); 3877 return(-1); 3878 } 3879 3880 strncpy(bname, path, endp - path + 1); 3881 bname[endp - path + 1] = '\0'; 3882 return (0); 3883 } 3884 3885 static int 3886 rtld_dirname_abs(const char *path, char *base) 3887 { 3888 char *last; 3889 3890 if (realpath(path, base) == NULL) 3891 return (-1); 3892 dbg("%s -> %s", path, base); 3893 last = strrchr(base, '/'); 3894 if (last == NULL) 3895 return (-1); 3896 if (last != base) 3897 *last = '\0'; 3898 return (0); 3899 } 3900 3901 static void 3902 linkmap_add(Obj_Entry *obj) 3903 { 3904 struct link_map *l = &obj->linkmap; 3905 struct link_map *prev; 3906 3907 obj->linkmap.l_name = obj->path; 3908 obj->linkmap.l_addr = obj->mapbase; 3909 obj->linkmap.l_ld = obj->dynamic; 3910 #ifdef __mips__ 3911 /* GDB needs load offset on MIPS to use the symbols */ 3912 obj->linkmap.l_offs = obj->relocbase; 3913 #endif 3914 3915 if (r_debug.r_map == NULL) { 3916 r_debug.r_map = l; 3917 return; 3918 } 3919 3920 /* 3921 * Scan to the end of the list, but not past the entry for the 3922 * dynamic linker, which we want to keep at the very end. 3923 */ 3924 for (prev = r_debug.r_map; 3925 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3926 prev = prev->l_next) 3927 ; 3928 3929 /* Link in the new entry. */ 3930 l->l_prev = prev; 3931 l->l_next = prev->l_next; 3932 if (l->l_next != NULL) 3933 l->l_next->l_prev = l; 3934 prev->l_next = l; 3935 } 3936 3937 static void 3938 linkmap_delete(Obj_Entry *obj) 3939 { 3940 struct link_map *l = &obj->linkmap; 3941 3942 if (l->l_prev == NULL) { 3943 if ((r_debug.r_map = l->l_next) != NULL) 3944 l->l_next->l_prev = NULL; 3945 return; 3946 } 3947 3948 if ((l->l_prev->l_next = l->l_next) != NULL) 3949 l->l_next->l_prev = l->l_prev; 3950 } 3951 3952 /* 3953 * Function for the debugger to set a breakpoint on to gain control. 3954 * 3955 * The two parameters allow the debugger to easily find and determine 3956 * what the runtime loader is doing and to whom it is doing it. 3957 * 3958 * When the loadhook trap is hit (r_debug_state, set at program 3959 * initialization), the arguments can be found on the stack: 3960 * 3961 * +8 struct link_map *m 3962 * +4 struct r_debug *rd 3963 * +0 RetAddr 3964 */ 3965 void 3966 r_debug_state(struct r_debug* rd, struct link_map *m) 3967 { 3968 /* 3969 * The following is a hack to force the compiler to emit calls to 3970 * this function, even when optimizing. If the function is empty, 3971 * the compiler is not obliged to emit any code for calls to it, 3972 * even when marked __noinline. However, gdb depends on those 3973 * calls being made. 3974 */ 3975 __compiler_membar(); 3976 } 3977 3978 /* 3979 * A function called after init routines have completed. This can be used to 3980 * break before a program's entry routine is called, and can be used when 3981 * main is not available in the symbol table. 3982 */ 3983 void 3984 _r_debug_postinit(struct link_map *m) 3985 { 3986 3987 /* See r_debug_state(). */ 3988 __compiler_membar(); 3989 } 3990 3991 static void 3992 release_object(Obj_Entry *obj) 3993 { 3994 3995 if (obj->holdcount > 0) { 3996 obj->unholdfree = true; 3997 return; 3998 } 3999 munmap(obj->mapbase, obj->mapsize); 4000 linkmap_delete(obj); 4001 obj_free(obj); 4002 } 4003 4004 /* 4005 * Get address of the pointer variable in the main program. 4006 * Prefer non-weak symbol over the weak one. 4007 */ 4008 static const void ** 4009 get_program_var_addr(const char *name, RtldLockState *lockstate) 4010 { 4011 SymLook req; 4012 DoneList donelist; 4013 4014 symlook_init(&req, name); 4015 req.lockstate = lockstate; 4016 donelist_init(&donelist); 4017 if (symlook_global(&req, &donelist) != 0) 4018 return (NULL); 4019 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4020 return ((const void **)make_function_pointer(req.sym_out, 4021 req.defobj_out)); 4022 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4023 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4024 else 4025 return ((const void **)(req.defobj_out->relocbase + 4026 req.sym_out->st_value)); 4027 } 4028 4029 /* 4030 * Set a pointer variable in the main program to the given value. This 4031 * is used to set key variables such as "environ" before any of the 4032 * init functions are called. 4033 */ 4034 static void 4035 set_program_var(const char *name, const void *value) 4036 { 4037 const void **addr; 4038 4039 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4040 dbg("\"%s\": *%p <-- %p", name, addr, value); 4041 *addr = value; 4042 } 4043 } 4044 4045 /* 4046 * Search the global objects, including dependencies and main object, 4047 * for the given symbol. 4048 */ 4049 static int 4050 symlook_global(SymLook *req, DoneList *donelist) 4051 { 4052 SymLook req1; 4053 const Objlist_Entry *elm; 4054 int res; 4055 4056 symlook_init_from_req(&req1, req); 4057 4058 /* Search all objects loaded at program start up. */ 4059 if (req->defobj_out == NULL || 4060 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4061 res = symlook_list(&req1, &list_main, donelist); 4062 if (res == 0 && (req->defobj_out == NULL || 4063 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4064 req->sym_out = req1.sym_out; 4065 req->defobj_out = req1.defobj_out; 4066 assert(req->defobj_out != NULL); 4067 } 4068 } 4069 4070 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4071 STAILQ_FOREACH(elm, &list_global, link) { 4072 if (req->defobj_out != NULL && 4073 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4074 break; 4075 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4076 if (res == 0 && (req->defobj_out == NULL || 4077 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4078 req->sym_out = req1.sym_out; 4079 req->defobj_out = req1.defobj_out; 4080 assert(req->defobj_out != NULL); 4081 } 4082 } 4083 4084 return (req->sym_out != NULL ? 0 : ESRCH); 4085 } 4086 4087 /* 4088 * Given a symbol name in a referencing object, find the corresponding 4089 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4090 * no definition was found. Returns a pointer to the Obj_Entry of the 4091 * defining object via the reference parameter DEFOBJ_OUT. 4092 */ 4093 static int 4094 symlook_default(SymLook *req, const Obj_Entry *refobj) 4095 { 4096 DoneList donelist; 4097 const Objlist_Entry *elm; 4098 SymLook req1; 4099 int res; 4100 4101 donelist_init(&donelist); 4102 symlook_init_from_req(&req1, req); 4103 4104 /* 4105 * Look first in the referencing object if linked symbolically, 4106 * and similarly handle protected symbols. 4107 */ 4108 res = symlook_obj(&req1, refobj); 4109 if (res == 0 && (refobj->symbolic || 4110 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4111 req->sym_out = req1.sym_out; 4112 req->defobj_out = req1.defobj_out; 4113 assert(req->defobj_out != NULL); 4114 } 4115 if (refobj->symbolic || req->defobj_out != NULL) 4116 donelist_check(&donelist, refobj); 4117 4118 symlook_global(req, &donelist); 4119 4120 /* Search all dlopened DAGs containing the referencing object. */ 4121 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4122 if (req->sym_out != NULL && 4123 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4124 break; 4125 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4126 if (res == 0 && (req->sym_out == NULL || 4127 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4128 req->sym_out = req1.sym_out; 4129 req->defobj_out = req1.defobj_out; 4130 assert(req->defobj_out != NULL); 4131 } 4132 } 4133 4134 /* 4135 * Search the dynamic linker itself, and possibly resolve the 4136 * symbol from there. This is how the application links to 4137 * dynamic linker services such as dlopen. 4138 */ 4139 if (req->sym_out == NULL || 4140 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4141 res = symlook_obj(&req1, &obj_rtld); 4142 if (res == 0) { 4143 req->sym_out = req1.sym_out; 4144 req->defobj_out = req1.defobj_out; 4145 assert(req->defobj_out != NULL); 4146 } 4147 } 4148 4149 return (req->sym_out != NULL ? 0 : ESRCH); 4150 } 4151 4152 static int 4153 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4154 { 4155 const Elf_Sym *def; 4156 const Obj_Entry *defobj; 4157 const Objlist_Entry *elm; 4158 SymLook req1; 4159 int res; 4160 4161 def = NULL; 4162 defobj = NULL; 4163 STAILQ_FOREACH(elm, objlist, link) { 4164 if (donelist_check(dlp, elm->obj)) 4165 continue; 4166 symlook_init_from_req(&req1, req); 4167 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4168 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4169 def = req1.sym_out; 4170 defobj = req1.defobj_out; 4171 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4172 break; 4173 } 4174 } 4175 } 4176 if (def != NULL) { 4177 req->sym_out = def; 4178 req->defobj_out = defobj; 4179 return (0); 4180 } 4181 return (ESRCH); 4182 } 4183 4184 /* 4185 * Search the chain of DAGS cointed to by the given Needed_Entry 4186 * for a symbol of the given name. Each DAG is scanned completely 4187 * before advancing to the next one. Returns a pointer to the symbol, 4188 * or NULL if no definition was found. 4189 */ 4190 static int 4191 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4192 { 4193 const Elf_Sym *def; 4194 const Needed_Entry *n; 4195 const Obj_Entry *defobj; 4196 SymLook req1; 4197 int res; 4198 4199 def = NULL; 4200 defobj = NULL; 4201 symlook_init_from_req(&req1, req); 4202 for (n = needed; n != NULL; n = n->next) { 4203 if (n->obj == NULL || 4204 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4205 continue; 4206 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4207 def = req1.sym_out; 4208 defobj = req1.defobj_out; 4209 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4210 break; 4211 } 4212 } 4213 if (def != NULL) { 4214 req->sym_out = def; 4215 req->defobj_out = defobj; 4216 return (0); 4217 } 4218 return (ESRCH); 4219 } 4220 4221 /* 4222 * Search the symbol table of a single shared object for a symbol of 4223 * the given name and version, if requested. Returns a pointer to the 4224 * symbol, or NULL if no definition was found. If the object is 4225 * filter, return filtered symbol from filtee. 4226 * 4227 * The symbol's hash value is passed in for efficiency reasons; that 4228 * eliminates many recomputations of the hash value. 4229 */ 4230 int 4231 symlook_obj(SymLook *req, const Obj_Entry *obj) 4232 { 4233 DoneList donelist; 4234 SymLook req1; 4235 int flags, res, mres; 4236 4237 /* 4238 * If there is at least one valid hash at this point, we prefer to 4239 * use the faster GNU version if available. 4240 */ 4241 if (obj->valid_hash_gnu) 4242 mres = symlook_obj1_gnu(req, obj); 4243 else if (obj->valid_hash_sysv) 4244 mres = symlook_obj1_sysv(req, obj); 4245 else 4246 return (EINVAL); 4247 4248 if (mres == 0) { 4249 if (obj->needed_filtees != NULL) { 4250 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4251 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4252 donelist_init(&donelist); 4253 symlook_init_from_req(&req1, req); 4254 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4255 if (res == 0) { 4256 req->sym_out = req1.sym_out; 4257 req->defobj_out = req1.defobj_out; 4258 } 4259 return (res); 4260 } 4261 if (obj->needed_aux_filtees != NULL) { 4262 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4263 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4264 donelist_init(&donelist); 4265 symlook_init_from_req(&req1, req); 4266 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4267 if (res == 0) { 4268 req->sym_out = req1.sym_out; 4269 req->defobj_out = req1.defobj_out; 4270 return (res); 4271 } 4272 } 4273 } 4274 return (mres); 4275 } 4276 4277 /* Symbol match routine common to both hash functions */ 4278 static bool 4279 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4280 const unsigned long symnum) 4281 { 4282 Elf_Versym verndx; 4283 const Elf_Sym *symp; 4284 const char *strp; 4285 4286 symp = obj->symtab + symnum; 4287 strp = obj->strtab + symp->st_name; 4288 4289 switch (ELF_ST_TYPE(symp->st_info)) { 4290 case STT_FUNC: 4291 case STT_NOTYPE: 4292 case STT_OBJECT: 4293 case STT_COMMON: 4294 case STT_GNU_IFUNC: 4295 if (symp->st_value == 0) 4296 return (false); 4297 /* fallthrough */ 4298 case STT_TLS: 4299 if (symp->st_shndx != SHN_UNDEF) 4300 break; 4301 #ifndef __mips__ 4302 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4303 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4304 break; 4305 /* fallthrough */ 4306 #endif 4307 default: 4308 return (false); 4309 } 4310 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4311 return (false); 4312 4313 if (req->ventry == NULL) { 4314 if (obj->versyms != NULL) { 4315 verndx = VER_NDX(obj->versyms[symnum]); 4316 if (verndx > obj->vernum) { 4317 _rtld_error( 4318 "%s: symbol %s references wrong version %d", 4319 obj->path, obj->strtab + symnum, verndx); 4320 return (false); 4321 } 4322 /* 4323 * If we are not called from dlsym (i.e. this 4324 * is a normal relocation from unversioned 4325 * binary), accept the symbol immediately if 4326 * it happens to have first version after this 4327 * shared object became versioned. Otherwise, 4328 * if symbol is versioned and not hidden, 4329 * remember it. If it is the only symbol with 4330 * this name exported by the shared object, it 4331 * will be returned as a match by the calling 4332 * function. If symbol is global (verndx < 2) 4333 * accept it unconditionally. 4334 */ 4335 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4336 verndx == VER_NDX_GIVEN) { 4337 result->sym_out = symp; 4338 return (true); 4339 } 4340 else if (verndx >= VER_NDX_GIVEN) { 4341 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4342 == 0) { 4343 if (result->vsymp == NULL) 4344 result->vsymp = symp; 4345 result->vcount++; 4346 } 4347 return (false); 4348 } 4349 } 4350 result->sym_out = symp; 4351 return (true); 4352 } 4353 if (obj->versyms == NULL) { 4354 if (object_match_name(obj, req->ventry->name)) { 4355 _rtld_error("%s: object %s should provide version %s " 4356 "for symbol %s", obj_rtld.path, obj->path, 4357 req->ventry->name, obj->strtab + symnum); 4358 return (false); 4359 } 4360 } else { 4361 verndx = VER_NDX(obj->versyms[symnum]); 4362 if (verndx > obj->vernum) { 4363 _rtld_error("%s: symbol %s references wrong version %d", 4364 obj->path, obj->strtab + symnum, verndx); 4365 return (false); 4366 } 4367 if (obj->vertab[verndx].hash != req->ventry->hash || 4368 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4369 /* 4370 * Version does not match. Look if this is a 4371 * global symbol and if it is not hidden. If 4372 * global symbol (verndx < 2) is available, 4373 * use it. Do not return symbol if we are 4374 * called by dlvsym, because dlvsym looks for 4375 * a specific version and default one is not 4376 * what dlvsym wants. 4377 */ 4378 if ((req->flags & SYMLOOK_DLSYM) || 4379 (verndx >= VER_NDX_GIVEN) || 4380 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4381 return (false); 4382 } 4383 } 4384 result->sym_out = symp; 4385 return (true); 4386 } 4387 4388 /* 4389 * Search for symbol using SysV hash function. 4390 * obj->buckets is known not to be NULL at this point; the test for this was 4391 * performed with the obj->valid_hash_sysv assignment. 4392 */ 4393 static int 4394 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4395 { 4396 unsigned long symnum; 4397 Sym_Match_Result matchres; 4398 4399 matchres.sym_out = NULL; 4400 matchres.vsymp = NULL; 4401 matchres.vcount = 0; 4402 4403 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4404 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4405 if (symnum >= obj->nchains) 4406 return (ESRCH); /* Bad object */ 4407 4408 if (matched_symbol(req, obj, &matchres, symnum)) { 4409 req->sym_out = matchres.sym_out; 4410 req->defobj_out = obj; 4411 return (0); 4412 } 4413 } 4414 if (matchres.vcount == 1) { 4415 req->sym_out = matchres.vsymp; 4416 req->defobj_out = obj; 4417 return (0); 4418 } 4419 return (ESRCH); 4420 } 4421 4422 /* Search for symbol using GNU hash function */ 4423 static int 4424 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4425 { 4426 Elf_Addr bloom_word; 4427 const Elf32_Word *hashval; 4428 Elf32_Word bucket; 4429 Sym_Match_Result matchres; 4430 unsigned int h1, h2; 4431 unsigned long symnum; 4432 4433 matchres.sym_out = NULL; 4434 matchres.vsymp = NULL; 4435 matchres.vcount = 0; 4436 4437 /* Pick right bitmask word from Bloom filter array */ 4438 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4439 obj->maskwords_bm_gnu]; 4440 4441 /* Calculate modulus word size of gnu hash and its derivative */ 4442 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4443 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4444 4445 /* Filter out the "definitely not in set" queries */ 4446 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4447 return (ESRCH); 4448 4449 /* Locate hash chain and corresponding value element*/ 4450 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4451 if (bucket == 0) 4452 return (ESRCH); 4453 hashval = &obj->chain_zero_gnu[bucket]; 4454 do { 4455 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4456 symnum = hashval - obj->chain_zero_gnu; 4457 if (matched_symbol(req, obj, &matchres, symnum)) { 4458 req->sym_out = matchres.sym_out; 4459 req->defobj_out = obj; 4460 return (0); 4461 } 4462 } 4463 } while ((*hashval++ & 1) == 0); 4464 if (matchres.vcount == 1) { 4465 req->sym_out = matchres.vsymp; 4466 req->defobj_out = obj; 4467 return (0); 4468 } 4469 return (ESRCH); 4470 } 4471 4472 static void 4473 trace_loaded_objects(Obj_Entry *obj) 4474 { 4475 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4476 int c; 4477 4478 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4479 main_local = ""; 4480 4481 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4482 fmt1 = "\t%o => %p (%x)\n"; 4483 4484 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4485 fmt2 = "\t%o (%x)\n"; 4486 4487 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4488 4489 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4490 Needed_Entry *needed; 4491 char *name, *path; 4492 bool is_lib; 4493 4494 if (obj->marker) 4495 continue; 4496 if (list_containers && obj->needed != NULL) 4497 rtld_printf("%s:\n", obj->path); 4498 for (needed = obj->needed; needed; needed = needed->next) { 4499 if (needed->obj != NULL) { 4500 if (needed->obj->traced && !list_containers) 4501 continue; 4502 needed->obj->traced = true; 4503 path = needed->obj->path; 4504 } else 4505 path = "not found"; 4506 4507 name = (char *)obj->strtab + needed->name; 4508 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4509 4510 fmt = is_lib ? fmt1 : fmt2; 4511 while ((c = *fmt++) != '\0') { 4512 switch (c) { 4513 default: 4514 rtld_putchar(c); 4515 continue; 4516 case '\\': 4517 switch (c = *fmt) { 4518 case '\0': 4519 continue; 4520 case 'n': 4521 rtld_putchar('\n'); 4522 break; 4523 case 't': 4524 rtld_putchar('\t'); 4525 break; 4526 } 4527 break; 4528 case '%': 4529 switch (c = *fmt) { 4530 case '\0': 4531 continue; 4532 case '%': 4533 default: 4534 rtld_putchar(c); 4535 break; 4536 case 'A': 4537 rtld_putstr(main_local); 4538 break; 4539 case 'a': 4540 rtld_putstr(obj_main->path); 4541 break; 4542 case 'o': 4543 rtld_putstr(name); 4544 break; 4545 #if 0 4546 case 'm': 4547 rtld_printf("%d", sodp->sod_major); 4548 break; 4549 case 'n': 4550 rtld_printf("%d", sodp->sod_minor); 4551 break; 4552 #endif 4553 case 'p': 4554 rtld_putstr(path); 4555 break; 4556 case 'x': 4557 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4558 0); 4559 break; 4560 } 4561 break; 4562 } 4563 ++fmt; 4564 } 4565 } 4566 } 4567 } 4568 4569 /* 4570 * Unload a dlopened object and its dependencies from memory and from 4571 * our data structures. It is assumed that the DAG rooted in the 4572 * object has already been unreferenced, and that the object has a 4573 * reference count of 0. 4574 */ 4575 static void 4576 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4577 { 4578 Obj_Entry marker, *obj, *next; 4579 4580 assert(root->refcount == 0); 4581 4582 /* 4583 * Pass over the DAG removing unreferenced objects from 4584 * appropriate lists. 4585 */ 4586 unlink_object(root); 4587 4588 /* Unmap all objects that are no longer referenced. */ 4589 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4590 next = TAILQ_NEXT(obj, next); 4591 if (obj->marker || obj->refcount != 0) 4592 continue; 4593 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4594 obj->mapsize, 0, obj->path); 4595 dbg("unloading \"%s\"", obj->path); 4596 /* 4597 * Unlink the object now to prevent new references from 4598 * being acquired while the bind lock is dropped in 4599 * recursive dlclose() invocations. 4600 */ 4601 TAILQ_REMOVE(&obj_list, obj, next); 4602 obj_count--; 4603 4604 if (obj->filtees_loaded) { 4605 if (next != NULL) { 4606 init_marker(&marker); 4607 TAILQ_INSERT_BEFORE(next, &marker, next); 4608 unload_filtees(obj, lockstate); 4609 next = TAILQ_NEXT(&marker, next); 4610 TAILQ_REMOVE(&obj_list, &marker, next); 4611 } else 4612 unload_filtees(obj, lockstate); 4613 } 4614 release_object(obj); 4615 } 4616 } 4617 4618 static void 4619 unlink_object(Obj_Entry *root) 4620 { 4621 Objlist_Entry *elm; 4622 4623 if (root->refcount == 0) { 4624 /* Remove the object from the RTLD_GLOBAL list. */ 4625 objlist_remove(&list_global, root); 4626 4627 /* Remove the object from all objects' DAG lists. */ 4628 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4629 objlist_remove(&elm->obj->dldags, root); 4630 if (elm->obj != root) 4631 unlink_object(elm->obj); 4632 } 4633 } 4634 } 4635 4636 static void 4637 ref_dag(Obj_Entry *root) 4638 { 4639 Objlist_Entry *elm; 4640 4641 assert(root->dag_inited); 4642 STAILQ_FOREACH(elm, &root->dagmembers, link) 4643 elm->obj->refcount++; 4644 } 4645 4646 static void 4647 unref_dag(Obj_Entry *root) 4648 { 4649 Objlist_Entry *elm; 4650 4651 assert(root->dag_inited); 4652 STAILQ_FOREACH(elm, &root->dagmembers, link) 4653 elm->obj->refcount--; 4654 } 4655 4656 /* 4657 * Common code for MD __tls_get_addr(). 4658 */ 4659 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4660 static void * 4661 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4662 { 4663 Elf_Addr *newdtv, *dtv; 4664 RtldLockState lockstate; 4665 int to_copy; 4666 4667 dtv = *dtvp; 4668 /* Check dtv generation in case new modules have arrived */ 4669 if (dtv[0] != tls_dtv_generation) { 4670 wlock_acquire(rtld_bind_lock, &lockstate); 4671 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4672 to_copy = dtv[1]; 4673 if (to_copy > tls_max_index) 4674 to_copy = tls_max_index; 4675 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4676 newdtv[0] = tls_dtv_generation; 4677 newdtv[1] = tls_max_index; 4678 free(dtv); 4679 lock_release(rtld_bind_lock, &lockstate); 4680 dtv = *dtvp = newdtv; 4681 } 4682 4683 /* Dynamically allocate module TLS if necessary */ 4684 if (dtv[index + 1] == 0) { 4685 /* Signal safe, wlock will block out signals. */ 4686 wlock_acquire(rtld_bind_lock, &lockstate); 4687 if (!dtv[index + 1]) 4688 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4689 lock_release(rtld_bind_lock, &lockstate); 4690 } 4691 return ((void *)(dtv[index + 1] + offset)); 4692 } 4693 4694 void * 4695 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4696 { 4697 Elf_Addr *dtv; 4698 4699 dtv = *dtvp; 4700 /* Check dtv generation in case new modules have arrived */ 4701 if (__predict_true(dtv[0] == tls_dtv_generation && 4702 dtv[index + 1] != 0)) 4703 return ((void *)(dtv[index + 1] + offset)); 4704 return (tls_get_addr_slow(dtvp, index, offset)); 4705 } 4706 4707 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4708 defined(__powerpc__) || defined(__riscv) 4709 4710 /* 4711 * Return pointer to allocated TLS block 4712 */ 4713 static void * 4714 get_tls_block_ptr(void *tcb, size_t tcbsize) 4715 { 4716 size_t extra_size, post_size, pre_size, tls_block_size; 4717 size_t tls_init_align; 4718 4719 tls_init_align = MAX(obj_main->tlsalign, 1); 4720 4721 /* Compute fragments sizes. */ 4722 extra_size = tcbsize - TLS_TCB_SIZE; 4723 post_size = calculate_tls_post_size(tls_init_align); 4724 tls_block_size = tcbsize + post_size; 4725 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4726 4727 return ((char *)tcb - pre_size - extra_size); 4728 } 4729 4730 /* 4731 * Allocate Static TLS using the Variant I method. 4732 * 4733 * For details on the layout, see lib/libc/gen/tls.c. 4734 * 4735 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4736 * it is based on tls_last_offset, and TLS offsets here are really TCB 4737 * offsets, whereas libc's tls_static_space is just the executable's static 4738 * TLS segment. 4739 */ 4740 void * 4741 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4742 { 4743 Obj_Entry *obj; 4744 char *tls_block; 4745 Elf_Addr *dtv, **tcb; 4746 Elf_Addr addr; 4747 int i; 4748 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4749 size_t tls_init_align; 4750 4751 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4752 return (oldtcb); 4753 4754 assert(tcbsize >= TLS_TCB_SIZE); 4755 maxalign = MAX(tcbalign, tls_static_max_align); 4756 tls_init_align = MAX(obj_main->tlsalign, 1); 4757 4758 /* Compute fragmets sizes. */ 4759 extra_size = tcbsize - TLS_TCB_SIZE; 4760 post_size = calculate_tls_post_size(tls_init_align); 4761 tls_block_size = tcbsize + post_size; 4762 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4763 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 4764 4765 /* Allocate whole TLS block */ 4766 tls_block = malloc_aligned(tls_block_size, maxalign); 4767 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 4768 4769 if (oldtcb != NULL) { 4770 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 4771 tls_static_space); 4772 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 4773 4774 /* Adjust the DTV. */ 4775 dtv = tcb[0]; 4776 for (i = 0; i < dtv[1]; i++) { 4777 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4778 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4779 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 4780 } 4781 } 4782 } else { 4783 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4784 tcb[0] = dtv; 4785 dtv[0] = tls_dtv_generation; 4786 dtv[1] = tls_max_index; 4787 4788 for (obj = globallist_curr(objs); obj != NULL; 4789 obj = globallist_next(obj)) { 4790 if (obj->tlsoffset > 0) { 4791 addr = (Elf_Addr)tcb + obj->tlsoffset; 4792 if (obj->tlsinitsize > 0) 4793 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4794 if (obj->tlssize > obj->tlsinitsize) 4795 memset((void*) (addr + obj->tlsinitsize), 0, 4796 obj->tlssize - obj->tlsinitsize); 4797 dtv[obj->tlsindex + 1] = addr; 4798 } 4799 } 4800 } 4801 4802 return (tcb); 4803 } 4804 4805 void 4806 free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4807 { 4808 Elf_Addr *dtv; 4809 Elf_Addr tlsstart, tlsend; 4810 size_t post_size; 4811 size_t dtvsize, i, tls_init_align; 4812 4813 assert(tcbsize >= TLS_TCB_SIZE); 4814 tls_init_align = MAX(obj_main->tlsalign, 1); 4815 4816 /* Compute fragments sizes. */ 4817 post_size = calculate_tls_post_size(tls_init_align); 4818 4819 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 4820 tlsend = (Elf_Addr)tcb + tls_static_space; 4821 4822 dtv = *(Elf_Addr **)tcb; 4823 dtvsize = dtv[1]; 4824 for (i = 0; i < dtvsize; i++) { 4825 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4826 free((void*)dtv[i+2]); 4827 } 4828 } 4829 free(dtv); 4830 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 4831 } 4832 4833 #endif 4834 4835 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4836 4837 /* 4838 * Allocate Static TLS using the Variant II method. 4839 */ 4840 void * 4841 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4842 { 4843 Obj_Entry *obj; 4844 size_t size, ralign; 4845 char *tls; 4846 Elf_Addr *dtv, *olddtv; 4847 Elf_Addr segbase, oldsegbase, addr; 4848 int i; 4849 4850 ralign = tcbalign; 4851 if (tls_static_max_align > ralign) 4852 ralign = tls_static_max_align; 4853 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4854 4855 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4856 tls = malloc_aligned(size, ralign); 4857 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4858 4859 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4860 ((Elf_Addr*)segbase)[0] = segbase; 4861 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4862 4863 dtv[0] = tls_dtv_generation; 4864 dtv[1] = tls_max_index; 4865 4866 if (oldtls) { 4867 /* 4868 * Copy the static TLS block over whole. 4869 */ 4870 oldsegbase = (Elf_Addr) oldtls; 4871 memcpy((void *)(segbase - tls_static_space), 4872 (const void *)(oldsegbase - tls_static_space), 4873 tls_static_space); 4874 4875 /* 4876 * If any dynamic TLS blocks have been created tls_get_addr(), 4877 * move them over. 4878 */ 4879 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4880 for (i = 0; i < olddtv[1]; i++) { 4881 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4882 dtv[i+2] = olddtv[i+2]; 4883 olddtv[i+2] = 0; 4884 } 4885 } 4886 4887 /* 4888 * We assume that this block was the one we created with 4889 * allocate_initial_tls(). 4890 */ 4891 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4892 } else { 4893 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4894 if (obj->marker || obj->tlsoffset == 0) 4895 continue; 4896 addr = segbase - obj->tlsoffset; 4897 memset((void*) (addr + obj->tlsinitsize), 4898 0, obj->tlssize - obj->tlsinitsize); 4899 if (obj->tlsinit) 4900 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4901 dtv[obj->tlsindex + 1] = addr; 4902 } 4903 } 4904 4905 return (void*) segbase; 4906 } 4907 4908 void 4909 free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4910 { 4911 Elf_Addr* dtv; 4912 size_t size, ralign; 4913 int dtvsize, i; 4914 Elf_Addr tlsstart, tlsend; 4915 4916 /* 4917 * Figure out the size of the initial TLS block so that we can 4918 * find stuff which ___tls_get_addr() allocated dynamically. 4919 */ 4920 ralign = tcbalign; 4921 if (tls_static_max_align > ralign) 4922 ralign = tls_static_max_align; 4923 size = round(tls_static_space, ralign); 4924 4925 dtv = ((Elf_Addr**)tls)[1]; 4926 dtvsize = dtv[1]; 4927 tlsend = (Elf_Addr) tls; 4928 tlsstart = tlsend - size; 4929 for (i = 0; i < dtvsize; i++) { 4930 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4931 free_aligned((void *)dtv[i + 2]); 4932 } 4933 } 4934 4935 free_aligned((void *)tlsstart); 4936 free((void*) dtv); 4937 } 4938 4939 #endif 4940 4941 /* 4942 * Allocate TLS block for module with given index. 4943 */ 4944 void * 4945 allocate_module_tls(int index) 4946 { 4947 Obj_Entry* obj; 4948 char* p; 4949 4950 TAILQ_FOREACH(obj, &obj_list, next) { 4951 if (obj->marker) 4952 continue; 4953 if (obj->tlsindex == index) 4954 break; 4955 } 4956 if (!obj) { 4957 _rtld_error("Can't find module with TLS index %d", index); 4958 rtld_die(); 4959 } 4960 4961 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4962 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4963 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4964 4965 return p; 4966 } 4967 4968 bool 4969 allocate_tls_offset(Obj_Entry *obj) 4970 { 4971 size_t off; 4972 4973 if (obj->tls_done) 4974 return true; 4975 4976 if (obj->tlssize == 0) { 4977 obj->tls_done = true; 4978 return true; 4979 } 4980 4981 if (tls_last_offset == 0) 4982 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4983 else 4984 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4985 obj->tlssize, obj->tlsalign); 4986 4987 /* 4988 * If we have already fixed the size of the static TLS block, we 4989 * must stay within that size. When allocating the static TLS, we 4990 * leave a small amount of space spare to be used for dynamically 4991 * loading modules which use static TLS. 4992 */ 4993 if (tls_static_space != 0) { 4994 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4995 return false; 4996 } else if (obj->tlsalign > tls_static_max_align) { 4997 tls_static_max_align = obj->tlsalign; 4998 } 4999 5000 tls_last_offset = obj->tlsoffset = off; 5001 tls_last_size = obj->tlssize; 5002 obj->tls_done = true; 5003 5004 return true; 5005 } 5006 5007 void 5008 free_tls_offset(Obj_Entry *obj) 5009 { 5010 5011 /* 5012 * If we were the last thing to allocate out of the static TLS 5013 * block, we give our space back to the 'allocator'. This is a 5014 * simplistic workaround to allow libGL.so.1 to be loaded and 5015 * unloaded multiple times. 5016 */ 5017 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5018 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5019 tls_last_offset -= obj->tlssize; 5020 tls_last_size = 0; 5021 } 5022 } 5023 5024 void * 5025 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5026 { 5027 void *ret; 5028 RtldLockState lockstate; 5029 5030 wlock_acquire(rtld_bind_lock, &lockstate); 5031 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5032 tcbsize, tcbalign); 5033 lock_release(rtld_bind_lock, &lockstate); 5034 return (ret); 5035 } 5036 5037 void 5038 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5039 { 5040 RtldLockState lockstate; 5041 5042 wlock_acquire(rtld_bind_lock, &lockstate); 5043 free_tls(tcb, tcbsize, tcbalign); 5044 lock_release(rtld_bind_lock, &lockstate); 5045 } 5046 5047 static void 5048 object_add_name(Obj_Entry *obj, const char *name) 5049 { 5050 Name_Entry *entry; 5051 size_t len; 5052 5053 len = strlen(name); 5054 entry = malloc(sizeof(Name_Entry) + len); 5055 5056 if (entry != NULL) { 5057 strcpy(entry->name, name); 5058 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5059 } 5060 } 5061 5062 static int 5063 object_match_name(const Obj_Entry *obj, const char *name) 5064 { 5065 Name_Entry *entry; 5066 5067 STAILQ_FOREACH(entry, &obj->names, link) { 5068 if (strcmp(name, entry->name) == 0) 5069 return (1); 5070 } 5071 return (0); 5072 } 5073 5074 static Obj_Entry * 5075 locate_dependency(const Obj_Entry *obj, const char *name) 5076 { 5077 const Objlist_Entry *entry; 5078 const Needed_Entry *needed; 5079 5080 STAILQ_FOREACH(entry, &list_main, link) { 5081 if (object_match_name(entry->obj, name)) 5082 return entry->obj; 5083 } 5084 5085 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5086 if (strcmp(obj->strtab + needed->name, name) == 0 || 5087 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5088 /* 5089 * If there is DT_NEEDED for the name we are looking for, 5090 * we are all set. Note that object might not be found if 5091 * dependency was not loaded yet, so the function can 5092 * return NULL here. This is expected and handled 5093 * properly by the caller. 5094 */ 5095 return (needed->obj); 5096 } 5097 } 5098 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5099 obj->path, name); 5100 rtld_die(); 5101 } 5102 5103 static int 5104 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5105 const Elf_Vernaux *vna) 5106 { 5107 const Elf_Verdef *vd; 5108 const char *vername; 5109 5110 vername = refobj->strtab + vna->vna_name; 5111 vd = depobj->verdef; 5112 if (vd == NULL) { 5113 _rtld_error("%s: version %s required by %s not defined", 5114 depobj->path, vername, refobj->path); 5115 return (-1); 5116 } 5117 for (;;) { 5118 if (vd->vd_version != VER_DEF_CURRENT) { 5119 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5120 depobj->path, vd->vd_version); 5121 return (-1); 5122 } 5123 if (vna->vna_hash == vd->vd_hash) { 5124 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5125 ((char *)vd + vd->vd_aux); 5126 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5127 return (0); 5128 } 5129 if (vd->vd_next == 0) 5130 break; 5131 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 5132 } 5133 if (vna->vna_flags & VER_FLG_WEAK) 5134 return (0); 5135 _rtld_error("%s: version %s required by %s not found", 5136 depobj->path, vername, refobj->path); 5137 return (-1); 5138 } 5139 5140 static int 5141 rtld_verify_object_versions(Obj_Entry *obj) 5142 { 5143 const Elf_Verneed *vn; 5144 const Elf_Verdef *vd; 5145 const Elf_Verdaux *vda; 5146 const Elf_Vernaux *vna; 5147 const Obj_Entry *depobj; 5148 int maxvernum, vernum; 5149 5150 if (obj->ver_checked) 5151 return (0); 5152 obj->ver_checked = true; 5153 5154 maxvernum = 0; 5155 /* 5156 * Walk over defined and required version records and figure out 5157 * max index used by any of them. Do very basic sanity checking 5158 * while there. 5159 */ 5160 vn = obj->verneed; 5161 while (vn != NULL) { 5162 if (vn->vn_version != VER_NEED_CURRENT) { 5163 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5164 obj->path, vn->vn_version); 5165 return (-1); 5166 } 5167 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 5168 for (;;) { 5169 vernum = VER_NEED_IDX(vna->vna_other); 5170 if (vernum > maxvernum) 5171 maxvernum = vernum; 5172 if (vna->vna_next == 0) 5173 break; 5174 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 5175 } 5176 if (vn->vn_next == 0) 5177 break; 5178 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 5179 } 5180 5181 vd = obj->verdef; 5182 while (vd != NULL) { 5183 if (vd->vd_version != VER_DEF_CURRENT) { 5184 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5185 obj->path, vd->vd_version); 5186 return (-1); 5187 } 5188 vernum = VER_DEF_IDX(vd->vd_ndx); 5189 if (vernum > maxvernum) 5190 maxvernum = vernum; 5191 if (vd->vd_next == 0) 5192 break; 5193 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 5194 } 5195 5196 if (maxvernum == 0) 5197 return (0); 5198 5199 /* 5200 * Store version information in array indexable by version index. 5201 * Verify that object version requirements are satisfied along the 5202 * way. 5203 */ 5204 obj->vernum = maxvernum + 1; 5205 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5206 5207 vd = obj->verdef; 5208 while (vd != NULL) { 5209 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5210 vernum = VER_DEF_IDX(vd->vd_ndx); 5211 assert(vernum <= maxvernum); 5212 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 5213 obj->vertab[vernum].hash = vd->vd_hash; 5214 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5215 obj->vertab[vernum].file = NULL; 5216 obj->vertab[vernum].flags = 0; 5217 } 5218 if (vd->vd_next == 0) 5219 break; 5220 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 5221 } 5222 5223 vn = obj->verneed; 5224 while (vn != NULL) { 5225 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5226 if (depobj == NULL) 5227 return (-1); 5228 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 5229 for (;;) { 5230 if (check_object_provided_version(obj, depobj, vna)) 5231 return (-1); 5232 vernum = VER_NEED_IDX(vna->vna_other); 5233 assert(vernum <= maxvernum); 5234 obj->vertab[vernum].hash = vna->vna_hash; 5235 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5236 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5237 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5238 VER_INFO_HIDDEN : 0; 5239 if (vna->vna_next == 0) 5240 break; 5241 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 5242 } 5243 if (vn->vn_next == 0) 5244 break; 5245 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 5246 } 5247 return 0; 5248 } 5249 5250 static int 5251 rtld_verify_versions(const Objlist *objlist) 5252 { 5253 Objlist_Entry *entry; 5254 int rc; 5255 5256 rc = 0; 5257 STAILQ_FOREACH(entry, objlist, link) { 5258 /* 5259 * Skip dummy objects or objects that have their version requirements 5260 * already checked. 5261 */ 5262 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5263 continue; 5264 if (rtld_verify_object_versions(entry->obj) == -1) { 5265 rc = -1; 5266 if (ld_tracing == NULL) 5267 break; 5268 } 5269 } 5270 if (rc == 0 || ld_tracing != NULL) 5271 rc = rtld_verify_object_versions(&obj_rtld); 5272 return rc; 5273 } 5274 5275 const Ver_Entry * 5276 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5277 { 5278 Elf_Versym vernum; 5279 5280 if (obj->vertab) { 5281 vernum = VER_NDX(obj->versyms[symnum]); 5282 if (vernum >= obj->vernum) { 5283 _rtld_error("%s: symbol %s has wrong verneed value %d", 5284 obj->path, obj->strtab + symnum, vernum); 5285 } else if (obj->vertab[vernum].hash != 0) { 5286 return &obj->vertab[vernum]; 5287 } 5288 } 5289 return NULL; 5290 } 5291 5292 int 5293 _rtld_get_stack_prot(void) 5294 { 5295 5296 return (stack_prot); 5297 } 5298 5299 int 5300 _rtld_is_dlopened(void *arg) 5301 { 5302 Obj_Entry *obj; 5303 RtldLockState lockstate; 5304 int res; 5305 5306 rlock_acquire(rtld_bind_lock, &lockstate); 5307 obj = dlcheck(arg); 5308 if (obj == NULL) 5309 obj = obj_from_addr(arg); 5310 if (obj == NULL) { 5311 _rtld_error("No shared object contains address"); 5312 lock_release(rtld_bind_lock, &lockstate); 5313 return (-1); 5314 } 5315 res = obj->dlopened ? 1 : 0; 5316 lock_release(rtld_bind_lock, &lockstate); 5317 return (res); 5318 } 5319 5320 int 5321 obj_enforce_relro(Obj_Entry *obj) 5322 { 5323 5324 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5325 PROT_READ) == -1) { 5326 _rtld_error("%s: Cannot enforce relro protection: %s", 5327 obj->path, rtld_strerror(errno)); 5328 return (-1); 5329 } 5330 return (0); 5331 } 5332 5333 static void 5334 map_stacks_exec(RtldLockState *lockstate) 5335 { 5336 void (*thr_map_stacks_exec)(void); 5337 5338 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5339 return; 5340 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5341 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5342 if (thr_map_stacks_exec != NULL) { 5343 stack_prot |= PROT_EXEC; 5344 thr_map_stacks_exec(); 5345 } 5346 } 5347 5348 void 5349 symlook_init(SymLook *dst, const char *name) 5350 { 5351 5352 bzero(dst, sizeof(*dst)); 5353 dst->name = name; 5354 dst->hash = elf_hash(name); 5355 dst->hash_gnu = gnu_hash(name); 5356 } 5357 5358 static void 5359 symlook_init_from_req(SymLook *dst, const SymLook *src) 5360 { 5361 5362 dst->name = src->name; 5363 dst->hash = src->hash; 5364 dst->hash_gnu = src->hash_gnu; 5365 dst->ventry = src->ventry; 5366 dst->flags = src->flags; 5367 dst->defobj_out = NULL; 5368 dst->sym_out = NULL; 5369 dst->lockstate = src->lockstate; 5370 } 5371 5372 static int 5373 open_binary_fd(const char *argv0, bool search_in_path) 5374 { 5375 char *pathenv, *pe, binpath[PATH_MAX]; 5376 int fd; 5377 5378 if (search_in_path && strchr(argv0, '/') == NULL) { 5379 pathenv = getenv("PATH"); 5380 if (pathenv == NULL) { 5381 _rtld_error("-p and no PATH environment variable"); 5382 rtld_die(); 5383 } 5384 pathenv = strdup(pathenv); 5385 if (pathenv == NULL) { 5386 _rtld_error("Cannot allocate memory"); 5387 rtld_die(); 5388 } 5389 fd = -1; 5390 errno = ENOENT; 5391 while ((pe = strsep(&pathenv, ":")) != NULL) { 5392 if (strlcpy(binpath, pe, sizeof(binpath)) >= 5393 sizeof(binpath)) 5394 continue; 5395 if (binpath[0] != '\0' && 5396 strlcat(binpath, "/", sizeof(binpath)) >= 5397 sizeof(binpath)) 5398 continue; 5399 if (strlcat(binpath, argv0, sizeof(binpath)) >= 5400 sizeof(binpath)) 5401 continue; 5402 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5403 if (fd != -1 || errno != ENOENT) 5404 break; 5405 } 5406 free(pathenv); 5407 } else { 5408 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5409 } 5410 5411 if (fd == -1) { 5412 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5413 rtld_die(); 5414 } 5415 return (fd); 5416 } 5417 5418 /* 5419 * Parse a set of command-line arguments. 5420 */ 5421 static int 5422 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp) 5423 { 5424 const char *arg; 5425 int fd, i, j, arglen; 5426 char opt; 5427 5428 dbg("Parsing command-line arguments"); 5429 *use_pathp = false; 5430 *fdp = -1; 5431 5432 for (i = 1; i < argc; i++ ) { 5433 arg = argv[i]; 5434 dbg("argv[%d]: '%s'", i, arg); 5435 5436 /* 5437 * rtld arguments end with an explicit "--" or with the first 5438 * non-prefixed argument. 5439 */ 5440 if (strcmp(arg, "--") == 0) { 5441 i++; 5442 break; 5443 } 5444 if (arg[0] != '-') 5445 break; 5446 5447 /* 5448 * All other arguments are single-character options that can 5449 * be combined, so we need to search through `arg` for them. 5450 */ 5451 arglen = strlen(arg); 5452 for (j = 1; j < arglen; j++) { 5453 opt = arg[j]; 5454 if (opt == 'h') { 5455 print_usage(argv[0]); 5456 _exit(0); 5457 } else if (opt == 'f') { 5458 /* 5459 * -f XX can be used to specify a descriptor for the 5460 * binary named at the command line (i.e., the later 5461 * argument will specify the process name but the 5462 * descriptor is what will actually be executed) 5463 */ 5464 if (j != arglen - 1) { 5465 /* -f must be the last option in, e.g., -abcf */ 5466 _rtld_error("Invalid options: %s", arg); 5467 rtld_die(); 5468 } 5469 i++; 5470 fd = parse_integer(argv[i]); 5471 if (fd == -1) { 5472 _rtld_error("Invalid file descriptor: '%s'", 5473 argv[i]); 5474 rtld_die(); 5475 } 5476 *fdp = fd; 5477 break; 5478 } else if (opt == 'p') { 5479 *use_pathp = true; 5480 } else { 5481 _rtld_error("Invalid argument: '%s'", arg); 5482 print_usage(argv[0]); 5483 rtld_die(); 5484 } 5485 } 5486 } 5487 5488 return (i); 5489 } 5490 5491 /* 5492 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5493 */ 5494 static int 5495 parse_integer(const char *str) 5496 { 5497 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5498 const char *orig; 5499 int n; 5500 char c; 5501 5502 orig = str; 5503 n = 0; 5504 for (c = *str; c != '\0'; c = *++str) { 5505 if (c < '0' || c > '9') 5506 return (-1); 5507 5508 n *= RADIX; 5509 n += c - '0'; 5510 } 5511 5512 /* Make sure we actually parsed something. */ 5513 if (str == orig) 5514 return (-1); 5515 return (n); 5516 } 5517 5518 static void 5519 print_usage(const char *argv0) 5520 { 5521 5522 rtld_printf("Usage: %s [-h] [-f <FD>] [--] <binary> [<args>]\n" 5523 "\n" 5524 "Options:\n" 5525 " -h Display this help message\n" 5526 " -p Search in PATH for named binary\n" 5527 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5528 " -- End of RTLD options\n" 5529 " <binary> Name of process to execute\n" 5530 " <args> Arguments to the executed process\n", argv0); 5531 } 5532 5533 /* 5534 * Overrides for libc_pic-provided functions. 5535 */ 5536 5537 int 5538 __getosreldate(void) 5539 { 5540 size_t len; 5541 int oid[2]; 5542 int error, osrel; 5543 5544 if (osreldate != 0) 5545 return (osreldate); 5546 5547 oid[0] = CTL_KERN; 5548 oid[1] = KERN_OSRELDATE; 5549 osrel = 0; 5550 len = sizeof(osrel); 5551 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5552 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5553 osreldate = osrel; 5554 return (osreldate); 5555 } 5556 5557 void 5558 exit(int status) 5559 { 5560 5561 _exit(status); 5562 } 5563 5564 void (*__cleanup)(void); 5565 int __isthreaded = 0; 5566 int _thread_autoinit_dummy_decl = 1; 5567 5568 /* 5569 * No unresolved symbols for rtld. 5570 */ 5571 void 5572 __pthread_cxa_finalize(struct dl_phdr_info *a) 5573 { 5574 } 5575 5576 const char * 5577 rtld_strerror(int errnum) 5578 { 5579 5580 if (errnum < 0 || errnum >= sys_nerr) 5581 return ("Unknown error"); 5582 return (sys_errlist[errnum]); 5583 } 5584