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 <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 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 <jdp@polstra.com>. 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)(void); 74 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 75 76 77 /* Variables that cannot be static: */ 78 extern struct r_debug r_debug; /* For GDB */ 79 extern int _thread_autoinit_dummy_decl; 80 extern char* __progname; 81 extern void (*__cleanup)(void); 82 83 84 /* 85 * Function declarations. 86 */ 87 static const char *basename(const char *); 88 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 89 const Elf_Dyn **, const Elf_Dyn **); 90 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 91 const Elf_Dyn *); 92 static void digest_dynamic(Obj_Entry *, int); 93 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 94 static Obj_Entry *dlcheck(void *); 95 static int dlclose_locked(void *, RtldLockState *); 96 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 97 int lo_flags, int mode, RtldLockState *lockstate); 98 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 99 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 100 static bool donelist_check(DoneList *, const Obj_Entry *); 101 static void errmsg_restore(char *); 102 static char *errmsg_save(void); 103 static void *fill_search_info(const char *, size_t, void *); 104 static char *find_library(const char *, const Obj_Entry *, int *); 105 static const char *gethints(bool); 106 static void hold_object(Obj_Entry *); 107 static void unhold_object(Obj_Entry *); 108 static void init_dag(Obj_Entry *); 109 static void init_marker(Obj_Entry *); 110 static void init_pagesizes(Elf_Auxinfo **aux_info); 111 static void init_rtld(caddr_t, Elf_Auxinfo **); 112 static void initlist_add_neededs(Needed_Entry *, Objlist *); 113 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 114 static void linkmap_add(Obj_Entry *); 115 static void linkmap_delete(Obj_Entry *); 116 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 117 static void unload_filtees(Obj_Entry *, RtldLockState *); 118 static int load_needed_objects(Obj_Entry *, int); 119 static int load_preload_objects(void); 120 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 121 static void map_stacks_exec(RtldLockState *); 122 static int obj_enforce_relro(Obj_Entry *); 123 static Obj_Entry *obj_from_addr(const void *); 124 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 125 static void objlist_call_init(Objlist *, RtldLockState *); 126 static void objlist_clear(Objlist *); 127 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 128 static void objlist_init(Objlist *); 129 static void objlist_push_head(Objlist *, Obj_Entry *); 130 static void objlist_push_tail(Objlist *, Obj_Entry *); 131 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 132 static void objlist_remove(Objlist *, Obj_Entry *); 133 static int open_binary_fd(const char *argv0, bool search_in_path); 134 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp); 135 static int parse_integer(const char *); 136 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 137 static void print_usage(const char *argv0); 138 static void release_object(Obj_Entry *); 139 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 140 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 141 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 142 int flags, RtldLockState *lockstate); 143 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 144 RtldLockState *); 145 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 146 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 147 int flags, RtldLockState *lockstate); 148 static int rtld_dirname(const char *, char *); 149 static int rtld_dirname_abs(const char *, char *); 150 static void *rtld_dlopen(const char *name, int fd, int mode); 151 static void rtld_exit(void); 152 static char *search_library_path(const char *, const char *, const char *, 153 int *); 154 static char *search_library_pathfds(const char *, const char *, int *); 155 static const void **get_program_var_addr(const char *, RtldLockState *); 156 static void set_program_var(const char *, const void *); 157 static int symlook_default(SymLook *, const Obj_Entry *refobj); 158 static int symlook_global(SymLook *, DoneList *); 159 static void symlook_init_from_req(SymLook *, const SymLook *); 160 static int symlook_list(SymLook *, const Objlist *, DoneList *); 161 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 162 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 163 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 164 static void trace_loaded_objects(Obj_Entry *); 165 static void unlink_object(Obj_Entry *); 166 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 167 static void unref_dag(Obj_Entry *); 168 static void ref_dag(Obj_Entry *); 169 static char *origin_subst_one(Obj_Entry *, char *, const char *, 170 const char *, bool); 171 static char *origin_subst(Obj_Entry *, const char *); 172 static bool obj_resolve_origin(Obj_Entry *obj); 173 static void preinit_main(void); 174 static int rtld_verify_versions(const Objlist *); 175 static int rtld_verify_object_versions(Obj_Entry *); 176 static void object_add_name(Obj_Entry *, const char *); 177 static int object_match_name(const Obj_Entry *, const char *); 178 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 179 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 180 struct dl_phdr_info *phdr_info); 181 static uint32_t gnu_hash(const char *); 182 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 183 const unsigned long); 184 185 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 186 void _r_debug_postinit(struct link_map *) __noinline __exported; 187 188 int __sys_openat(int, const char *, int, ...); 189 190 /* 191 * Data declarations. 192 */ 193 static char *error_message; /* Message for dlerror(), or NULL */ 194 struct r_debug r_debug __exported; /* for GDB; */ 195 static bool libmap_disable; /* Disable libmap */ 196 static bool ld_loadfltr; /* Immediate filters processing */ 197 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 198 static bool trust; /* False for setuid and setgid programs */ 199 static bool dangerous_ld_env; /* True if environment variables have been 200 used to affect the libraries loaded */ 201 bool ld_bind_not; /* Disable PLT update */ 202 static char *ld_bind_now; /* Environment variable for immediate binding */ 203 static char *ld_debug; /* Environment variable for debugging */ 204 static char *ld_library_path; /* Environment variable for search path */ 205 static char *ld_library_dirs; /* Environment variable for library descriptors */ 206 static char *ld_preload; /* Environment variable for libraries to 207 load first */ 208 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 209 static const char *ld_tracing; /* Called from ldd to print libs */ 210 static char *ld_utrace; /* Use utrace() to log events. */ 211 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 212 static Obj_Entry *obj_main; /* The main program shared object */ 213 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 214 static unsigned int obj_count; /* Number of objects in obj_list */ 215 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 216 217 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 218 STAILQ_HEAD_INITIALIZER(list_global); 219 static Objlist list_main = /* Objects loaded at program startup */ 220 STAILQ_HEAD_INITIALIZER(list_main); 221 static Objlist list_fini = /* Objects needing fini() calls */ 222 STAILQ_HEAD_INITIALIZER(list_fini); 223 224 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 225 226 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 227 228 extern Elf_Dyn _DYNAMIC; 229 #pragma weak _DYNAMIC 230 231 int dlclose(void *) __exported; 232 char *dlerror(void) __exported; 233 void *dlopen(const char *, int) __exported; 234 void *fdlopen(int, int) __exported; 235 void *dlsym(void *, const char *) __exported; 236 dlfunc_t dlfunc(void *, const char *) __exported; 237 void *dlvsym(void *, const char *, const char *) __exported; 238 int dladdr(const void *, Dl_info *) __exported; 239 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 240 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 241 int dlinfo(void *, int , void *) __exported; 242 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 243 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 244 int _rtld_get_stack_prot(void) __exported; 245 int _rtld_is_dlopened(void *) __exported; 246 void _rtld_error(const char *, ...) __exported; 247 248 /* Only here to fix -Wmissing-prototypes warnings */ 249 int __getosreldate(void); 250 void __pthread_cxa_finalize(struct dl_phdr_info *a); 251 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 252 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 253 254 255 int npagesizes; 256 static int osreldate; 257 size_t *pagesizes; 258 259 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 260 static int max_stack_flags; 261 262 /* 263 * Global declarations normally provided by crt1. The dynamic linker is 264 * not built with crt1, so we have to provide them ourselves. 265 */ 266 char *__progname; 267 char **environ; 268 269 /* 270 * Used to pass argc, argv to init functions. 271 */ 272 int main_argc; 273 char **main_argv; 274 275 /* 276 * Globals to control TLS allocation. 277 */ 278 size_t tls_last_offset; /* Static TLS offset of last module */ 279 size_t tls_last_size; /* Static TLS size of last module */ 280 size_t tls_static_space; /* Static TLS space allocated */ 281 static size_t tls_static_max_align; 282 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 283 int tls_max_index = 1; /* Largest module index allocated */ 284 285 static bool ld_library_path_rpath = false; 286 287 /* 288 * Globals for path names, and such 289 */ 290 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 291 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 292 const char *ld_path_rtld = _PATH_RTLD; 293 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 294 const char *ld_env_prefix = LD_; 295 296 /* 297 * Fill in a DoneList with an allocation large enough to hold all of 298 * the currently-loaded objects. Keep this as a macro since it calls 299 * alloca and we want that to occur within the scope of the caller. 300 */ 301 #define donelist_init(dlp) \ 302 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 303 assert((dlp)->objs != NULL), \ 304 (dlp)->num_alloc = obj_count, \ 305 (dlp)->num_used = 0) 306 307 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 308 if (ld_utrace != NULL) \ 309 ld_utrace_log(e, h, mb, ms, r, n); \ 310 } while (0) 311 312 static void 313 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 314 int refcnt, const char *name) 315 { 316 struct utrace_rtld ut; 317 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 318 319 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 320 ut.event = event; 321 ut.handle = handle; 322 ut.mapbase = mapbase; 323 ut.mapsize = mapsize; 324 ut.refcnt = refcnt; 325 bzero(ut.name, sizeof(ut.name)); 326 if (name) 327 strlcpy(ut.name, name, sizeof(ut.name)); 328 utrace(&ut, sizeof(ut)); 329 } 330 331 #ifdef RTLD_VARIANT_ENV_NAMES 332 /* 333 * construct the env variable based on the type of binary that's 334 * running. 335 */ 336 static inline const char * 337 _LD(const char *var) 338 { 339 static char buffer[128]; 340 341 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 342 strlcat(buffer, var, sizeof(buffer)); 343 return (buffer); 344 } 345 #else 346 #define _LD(x) LD_ x 347 #endif 348 349 /* 350 * Main entry point for dynamic linking. The first argument is the 351 * stack pointer. The stack is expected to be laid out as described 352 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 353 * Specifically, the stack pointer points to a word containing 354 * ARGC. Following that in the stack is a null-terminated sequence 355 * of pointers to argument strings. Then comes a null-terminated 356 * sequence of pointers to environment strings. Finally, there is a 357 * sequence of "auxiliary vector" entries. 358 * 359 * The second argument points to a place to store the dynamic linker's 360 * exit procedure pointer and the third to a place to store the main 361 * program's object. 362 * 363 * The return value is the main program's entry point. 364 */ 365 func_ptr_type 366 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 367 { 368 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 369 Objlist_Entry *entry; 370 Obj_Entry *last_interposer, *obj, *preload_tail; 371 const Elf_Phdr *phdr; 372 Objlist initlist; 373 RtldLockState lockstate; 374 struct stat st; 375 Elf_Addr *argcp; 376 char **argv, **env, **envp, *kexecpath, *library_path_rpath; 377 const char *argv0; 378 caddr_t imgentry; 379 char buf[MAXPATHLEN]; 380 int argc, fd, i, phnum, rtld_argc; 381 bool dir_enable, explicit_fd, search_in_path; 382 383 /* 384 * On entry, the dynamic linker itself has not been relocated yet. 385 * Be very careful not to reference any global data until after 386 * init_rtld has returned. It is OK to reference file-scope statics 387 * and string constants, and to call static and global functions. 388 */ 389 390 /* Find the auxiliary vector on the stack. */ 391 argcp = sp; 392 argc = *sp++; 393 argv = (char **) sp; 394 sp += argc + 1; /* Skip over arguments and NULL terminator */ 395 env = (char **) sp; 396 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 397 ; 398 aux = (Elf_Auxinfo *) sp; 399 400 /* Digest the auxiliary vector. */ 401 for (i = 0; i < AT_COUNT; i++) 402 aux_info[i] = NULL; 403 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 404 if (auxp->a_type < AT_COUNT) 405 aux_info[auxp->a_type] = auxp; 406 } 407 408 /* Initialize and relocate ourselves. */ 409 assert(aux_info[AT_BASE] != NULL); 410 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 411 412 __progname = obj_rtld.path; 413 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 414 environ = env; 415 main_argc = argc; 416 main_argv = argv; 417 418 trust = !issetugid(); 419 420 md_abi_variant_hook(aux_info); 421 422 fd = -1; 423 if (aux_info[AT_EXECFD] != NULL) { 424 fd = aux_info[AT_EXECFD]->a_un.a_val; 425 } else { 426 assert(aux_info[AT_PHDR] != NULL); 427 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 428 if (phdr == obj_rtld.phdr) { 429 if (!trust) { 430 _rtld_error("Tainted process refusing to run binary %s", 431 argv0); 432 rtld_die(); 433 } 434 dbg("opening main program in direct exec mode"); 435 if (argc >= 2) { 436 rtld_argc = parse_args(argv, argc, &search_in_path, &fd); 437 argv0 = argv[rtld_argc]; 438 explicit_fd = (fd != -1); 439 if (!explicit_fd) 440 fd = open_binary_fd(argv0, search_in_path); 441 if (fstat(fd, &st) == -1) { 442 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 443 explicit_fd ? "user-provided descriptor" : argv0, 444 rtld_strerror(errno)); 445 rtld_die(); 446 } 447 448 /* 449 * Rough emulation of the permission checks done by 450 * execve(2), only Unix DACs are checked, ACLs are 451 * ignored. Preserve the semantic of disabling owner 452 * to execute if owner x bit is cleared, even if 453 * others x bit is enabled. 454 * mmap(2) does not allow to mmap with PROT_EXEC if 455 * binary' file comes from noexec mount. We cannot 456 * set VV_TEXT on the binary. 457 */ 458 dir_enable = false; 459 if (st.st_uid == geteuid()) { 460 if ((st.st_mode & S_IXUSR) != 0) 461 dir_enable = true; 462 } else if (st.st_gid == getegid()) { 463 if ((st.st_mode & S_IXGRP) != 0) 464 dir_enable = true; 465 } else if ((st.st_mode & S_IXOTH) != 0) { 466 dir_enable = true; 467 } 468 if (!dir_enable) { 469 _rtld_error("No execute permission for binary %s", 470 argv0); 471 rtld_die(); 472 } 473 474 /* 475 * For direct exec mode, argv[0] is the interpreter 476 * name, we must remove it and shift arguments left 477 * before invoking binary main. Since stack layout 478 * places environment pointers and aux vectors right 479 * after the terminating NULL, we must shift 480 * environment and aux as well. 481 */ 482 main_argc = argc - rtld_argc; 483 for (i = 0; i <= main_argc; i++) 484 argv[i] = argv[i + rtld_argc]; 485 *argcp -= rtld_argc; 486 environ = env = envp = argv + main_argc + 1; 487 do { 488 *envp = *(envp + rtld_argc); 489 envp++; 490 } while (*envp != NULL); 491 aux = auxp = (Elf_Auxinfo *)envp; 492 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 493 for (;; auxp++, auxpf++) { 494 *auxp = *auxpf; 495 if (auxp->a_type == AT_NULL) 496 break; 497 } 498 } else { 499 _rtld_error("No binary"); 500 rtld_die(); 501 } 502 } 503 } 504 505 ld_bind_now = getenv(_LD("BIND_NOW")); 506 507 /* 508 * If the process is tainted, then we un-set the dangerous environment 509 * variables. The process will be marked as tainted until setuid(2) 510 * is called. If any child process calls setuid(2) we do not want any 511 * future processes to honor the potentially un-safe variables. 512 */ 513 if (!trust) { 514 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 515 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 516 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 517 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 518 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) { 519 _rtld_error("environment corrupt; aborting"); 520 rtld_die(); 521 } 522 } 523 ld_debug = getenv(_LD("DEBUG")); 524 if (ld_bind_now == NULL) 525 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 526 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 527 libmap_override = getenv(_LD("LIBMAP")); 528 ld_library_path = getenv(_LD("LIBRARY_PATH")); 529 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 530 ld_preload = getenv(_LD("PRELOAD")); 531 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 532 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 533 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 534 if (library_path_rpath != NULL) { 535 if (library_path_rpath[0] == 'y' || 536 library_path_rpath[0] == 'Y' || 537 library_path_rpath[0] == '1') 538 ld_library_path_rpath = true; 539 else 540 ld_library_path_rpath = false; 541 } 542 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 543 (ld_library_path != NULL) || (ld_preload != NULL) || 544 (ld_elf_hints_path != NULL) || ld_loadfltr; 545 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 546 ld_utrace = getenv(_LD("UTRACE")); 547 548 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 549 ld_elf_hints_path = ld_elf_hints_default; 550 551 if (ld_debug != NULL && *ld_debug != '\0') 552 debug = 1; 553 dbg("%s is initialized, base address = %p", __progname, 554 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 555 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 556 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 557 558 dbg("initializing thread locks"); 559 lockdflt_init(); 560 561 /* 562 * Load the main program, or process its program header if it is 563 * already loaded. 564 */ 565 if (fd != -1) { /* Load the main program. */ 566 dbg("loading main program"); 567 obj_main = map_object(fd, argv0, NULL); 568 close(fd); 569 if (obj_main == NULL) 570 rtld_die(); 571 max_stack_flags = obj_main->stack_flags; 572 } else { /* Main program already loaded. */ 573 dbg("processing main program's program header"); 574 assert(aux_info[AT_PHDR] != NULL); 575 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 576 assert(aux_info[AT_PHNUM] != NULL); 577 phnum = aux_info[AT_PHNUM]->a_un.a_val; 578 assert(aux_info[AT_PHENT] != NULL); 579 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 580 assert(aux_info[AT_ENTRY] != NULL); 581 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 582 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 583 rtld_die(); 584 } 585 586 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 587 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 588 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 589 if (kexecpath[0] == '/') 590 obj_main->path = kexecpath; 591 else if (getcwd(buf, sizeof(buf)) == NULL || 592 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 593 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 594 obj_main->path = xstrdup(argv0); 595 else 596 obj_main->path = xstrdup(buf); 597 } else { 598 dbg("No AT_EXECPATH or direct exec"); 599 obj_main->path = xstrdup(argv0); 600 } 601 dbg("obj_main path %s", obj_main->path); 602 obj_main->mainprog = true; 603 604 if (aux_info[AT_STACKPROT] != NULL && 605 aux_info[AT_STACKPROT]->a_un.a_val != 0) 606 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 607 608 #ifndef COMPAT_32BIT 609 /* 610 * Get the actual dynamic linker pathname from the executable if 611 * possible. (It should always be possible.) That ensures that 612 * gdb will find the right dynamic linker even if a non-standard 613 * one is being used. 614 */ 615 if (obj_main->interp != NULL && 616 strcmp(obj_main->interp, obj_rtld.path) != 0) { 617 free(obj_rtld.path); 618 obj_rtld.path = xstrdup(obj_main->interp); 619 __progname = obj_rtld.path; 620 } 621 #endif 622 623 digest_dynamic(obj_main, 0); 624 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 625 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 626 obj_main->dynsymcount); 627 628 linkmap_add(obj_main); 629 linkmap_add(&obj_rtld); 630 631 /* Link the main program into the list of objects. */ 632 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 633 obj_count++; 634 obj_loads++; 635 636 /* Initialize a fake symbol for resolving undefined weak references. */ 637 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 638 sym_zero.st_shndx = SHN_UNDEF; 639 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 640 641 if (!libmap_disable) 642 libmap_disable = (bool)lm_init(libmap_override); 643 644 dbg("loading LD_PRELOAD libraries"); 645 if (load_preload_objects() == -1) 646 rtld_die(); 647 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 648 649 dbg("loading needed objects"); 650 if (load_needed_objects(obj_main, 0) == -1) 651 rtld_die(); 652 653 /* Make a list of all objects loaded at startup. */ 654 last_interposer = obj_main; 655 TAILQ_FOREACH(obj, &obj_list, next) { 656 if (obj->marker) 657 continue; 658 if (obj->z_interpose && obj != obj_main) { 659 objlist_put_after(&list_main, last_interposer, obj); 660 last_interposer = obj; 661 } else { 662 objlist_push_tail(&list_main, obj); 663 } 664 obj->refcount++; 665 } 666 667 dbg("checking for required versions"); 668 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 669 rtld_die(); 670 671 if (ld_tracing) { /* We're done */ 672 trace_loaded_objects(obj_main); 673 exit(0); 674 } 675 676 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 677 dump_relocations(obj_main); 678 exit (0); 679 } 680 681 /* 682 * Processing tls relocations requires having the tls offsets 683 * initialized. Prepare offsets before starting initial 684 * relocation processing. 685 */ 686 dbg("initializing initial thread local storage offsets"); 687 STAILQ_FOREACH(entry, &list_main, link) { 688 /* 689 * Allocate all the initial objects out of the static TLS 690 * block even if they didn't ask for it. 691 */ 692 allocate_tls_offset(entry->obj); 693 } 694 695 if (relocate_objects(obj_main, 696 ld_bind_now != NULL && *ld_bind_now != '\0', 697 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 698 rtld_die(); 699 700 dbg("doing copy relocations"); 701 if (do_copy_relocations(obj_main) == -1) 702 rtld_die(); 703 704 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 705 dump_relocations(obj_main); 706 exit (0); 707 } 708 709 ifunc_init(aux); 710 711 /* 712 * Setup TLS for main thread. This must be done after the 713 * relocations are processed, since tls initialization section 714 * might be the subject for relocations. 715 */ 716 dbg("initializing initial thread local storage"); 717 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 718 719 dbg("initializing key program variables"); 720 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 721 set_program_var("environ", env); 722 set_program_var("__elf_aux_vector", aux); 723 724 /* Make a list of init functions to call. */ 725 objlist_init(&initlist); 726 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 727 preload_tail, &initlist); 728 729 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 730 731 map_stacks_exec(NULL); 732 733 dbg("resolving ifuncs"); 734 if (resolve_objects_ifunc(obj_main, 735 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 736 NULL) == -1) 737 rtld_die(); 738 739 dbg("enforcing main obj relro"); 740 if (obj_enforce_relro(obj_main) == -1) 741 rtld_die(); 742 743 if (!obj_main->crt_no_init) { 744 /* 745 * Make sure we don't call the main program's init and fini 746 * functions for binaries linked with old crt1 which calls 747 * _init itself. 748 */ 749 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 750 obj_main->preinit_array = obj_main->init_array = 751 obj_main->fini_array = (Elf_Addr)NULL; 752 } 753 754 /* 755 * Execute MD initializers required before we call the objects' 756 * init functions. 757 */ 758 pre_init(); 759 760 wlock_acquire(rtld_bind_lock, &lockstate); 761 if (obj_main->crt_no_init) 762 preinit_main(); 763 objlist_call_init(&initlist, &lockstate); 764 _r_debug_postinit(&obj_main->linkmap); 765 objlist_clear(&initlist); 766 dbg("loading filtees"); 767 TAILQ_FOREACH(obj, &obj_list, next) { 768 if (obj->marker) 769 continue; 770 if (ld_loadfltr || obj->z_loadfltr) 771 load_filtees(obj, 0, &lockstate); 772 } 773 lock_release(rtld_bind_lock, &lockstate); 774 775 dbg("transferring control to program entry point = %p", obj_main->entry); 776 777 /* Return the exit procedure and the program entry point. */ 778 *exit_proc = rtld_exit; 779 *objp = obj_main; 780 return (func_ptr_type) obj_main->entry; 781 } 782 783 void * 784 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 785 { 786 void *ptr; 787 Elf_Addr target; 788 789 ptr = (void *)make_function_pointer(def, obj); 790 target = call_ifunc_resolver(ptr); 791 return ((void *)target); 792 } 793 794 /* 795 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 796 * Changes to this function should be applied there as well. 797 */ 798 Elf_Addr 799 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 800 { 801 const Elf_Rel *rel; 802 const Elf_Sym *def; 803 const Obj_Entry *defobj; 804 Elf_Addr *where; 805 Elf_Addr target; 806 RtldLockState lockstate; 807 808 rlock_acquire(rtld_bind_lock, &lockstate); 809 if (sigsetjmp(lockstate.env, 0) != 0) 810 lock_upgrade(rtld_bind_lock, &lockstate); 811 if (obj->pltrel) 812 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 813 else 814 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 815 816 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 817 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 818 NULL, &lockstate); 819 if (def == NULL) 820 rtld_die(); 821 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 822 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 823 else 824 target = (Elf_Addr)(defobj->relocbase + def->st_value); 825 826 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 827 defobj->strtab + def->st_name, basename(obj->path), 828 (void *)target, basename(defobj->path)); 829 830 /* 831 * Write the new contents for the jmpslot. Note that depending on 832 * architecture, the value which we need to return back to the 833 * lazy binding trampoline may or may not be the target 834 * address. The value returned from reloc_jmpslot() is the value 835 * that the trampoline needs. 836 */ 837 target = reloc_jmpslot(where, target, defobj, obj, rel); 838 lock_release(rtld_bind_lock, &lockstate); 839 return target; 840 } 841 842 /* 843 * Error reporting function. Use it like printf. If formats the message 844 * into a buffer, and sets things up so that the next call to dlerror() 845 * will return the message. 846 */ 847 void 848 _rtld_error(const char *fmt, ...) 849 { 850 static char buf[512]; 851 va_list ap; 852 853 va_start(ap, fmt); 854 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 855 error_message = buf; 856 va_end(ap); 857 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message); 858 } 859 860 /* 861 * Return a dynamically-allocated copy of the current error message, if any. 862 */ 863 static char * 864 errmsg_save(void) 865 { 866 return error_message == NULL ? NULL : xstrdup(error_message); 867 } 868 869 /* 870 * Restore the current error message from a copy which was previously saved 871 * by errmsg_save(). The copy is freed. 872 */ 873 static void 874 errmsg_restore(char *saved_msg) 875 { 876 if (saved_msg == NULL) 877 error_message = NULL; 878 else { 879 _rtld_error("%s", saved_msg); 880 free(saved_msg); 881 } 882 } 883 884 static const char * 885 basename(const char *name) 886 { 887 const char *p = strrchr(name, '/'); 888 return p != NULL ? p + 1 : name; 889 } 890 891 static struct utsname uts; 892 893 static char * 894 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 895 const char *subst, bool may_free) 896 { 897 char *p, *p1, *res, *resp; 898 int subst_len, kw_len, subst_count, old_len, new_len; 899 900 kw_len = strlen(kw); 901 902 /* 903 * First, count the number of the keyword occurrences, to 904 * preallocate the final string. 905 */ 906 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 907 p1 = strstr(p, kw); 908 if (p1 == NULL) 909 break; 910 } 911 912 /* 913 * If the keyword is not found, just return. 914 * 915 * Return non-substituted string if resolution failed. We 916 * cannot do anything more reasonable, the failure mode of the 917 * caller is unresolved library anyway. 918 */ 919 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 920 return (may_free ? real : xstrdup(real)); 921 if (obj != NULL) 922 subst = obj->origin_path; 923 924 /* 925 * There is indeed something to substitute. Calculate the 926 * length of the resulting string, and allocate it. 927 */ 928 subst_len = strlen(subst); 929 old_len = strlen(real); 930 new_len = old_len + (subst_len - kw_len) * subst_count; 931 res = xmalloc(new_len + 1); 932 933 /* 934 * Now, execute the substitution loop. 935 */ 936 for (p = real, resp = res, *resp = '\0';;) { 937 p1 = strstr(p, kw); 938 if (p1 != NULL) { 939 /* Copy the prefix before keyword. */ 940 memcpy(resp, p, p1 - p); 941 resp += p1 - p; 942 /* Keyword replacement. */ 943 memcpy(resp, subst, subst_len); 944 resp += subst_len; 945 *resp = '\0'; 946 p = p1 + kw_len; 947 } else 948 break; 949 } 950 951 /* Copy to the end of string and finish. */ 952 strcat(resp, p); 953 if (may_free) 954 free(real); 955 return (res); 956 } 957 958 static char * 959 origin_subst(Obj_Entry *obj, const char *real) 960 { 961 char *res1, *res2, *res3, *res4; 962 963 if (obj == NULL || !trust) 964 return (xstrdup(real)); 965 if (uts.sysname[0] == '\0') { 966 if (uname(&uts) != 0) { 967 _rtld_error("utsname failed: %d", errno); 968 return (NULL); 969 } 970 } 971 /* __DECONST is safe here since without may_free real is unchanged */ 972 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 973 false); 974 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 975 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 976 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 977 return (res4); 978 } 979 980 void 981 rtld_die(void) 982 { 983 const char *msg = dlerror(); 984 985 if (msg == NULL) 986 msg = "Fatal error"; 987 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 988 rtld_fdputstr(STDERR_FILENO, msg); 989 rtld_fdputchar(STDERR_FILENO, '\n'); 990 _exit(1); 991 } 992 993 /* 994 * Process a shared object's DYNAMIC section, and save the important 995 * information in its Obj_Entry structure. 996 */ 997 static void 998 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 999 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1000 { 1001 const Elf_Dyn *dynp; 1002 Needed_Entry **needed_tail = &obj->needed; 1003 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1004 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1005 const Elf_Hashelt *hashtab; 1006 const Elf32_Word *hashval; 1007 Elf32_Word bkt, nmaskwords; 1008 int bloom_size32; 1009 int plttype = DT_REL; 1010 1011 *dyn_rpath = NULL; 1012 *dyn_soname = NULL; 1013 *dyn_runpath = NULL; 1014 1015 obj->bind_now = false; 1016 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 1017 switch (dynp->d_tag) { 1018 1019 case DT_REL: 1020 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1021 break; 1022 1023 case DT_RELSZ: 1024 obj->relsize = dynp->d_un.d_val; 1025 break; 1026 1027 case DT_RELENT: 1028 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1029 break; 1030 1031 case DT_JMPREL: 1032 obj->pltrel = (const Elf_Rel *) 1033 (obj->relocbase + dynp->d_un.d_ptr); 1034 break; 1035 1036 case DT_PLTRELSZ: 1037 obj->pltrelsize = dynp->d_un.d_val; 1038 break; 1039 1040 case DT_RELA: 1041 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1042 break; 1043 1044 case DT_RELASZ: 1045 obj->relasize = dynp->d_un.d_val; 1046 break; 1047 1048 case DT_RELAENT: 1049 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1050 break; 1051 1052 case DT_PLTREL: 1053 plttype = dynp->d_un.d_val; 1054 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1055 break; 1056 1057 case DT_SYMTAB: 1058 obj->symtab = (const Elf_Sym *) 1059 (obj->relocbase + dynp->d_un.d_ptr); 1060 break; 1061 1062 case DT_SYMENT: 1063 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1064 break; 1065 1066 case DT_STRTAB: 1067 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1068 break; 1069 1070 case DT_STRSZ: 1071 obj->strsize = dynp->d_un.d_val; 1072 break; 1073 1074 case DT_VERNEED: 1075 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1076 dynp->d_un.d_val); 1077 break; 1078 1079 case DT_VERNEEDNUM: 1080 obj->verneednum = dynp->d_un.d_val; 1081 break; 1082 1083 case DT_VERDEF: 1084 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1085 dynp->d_un.d_val); 1086 break; 1087 1088 case DT_VERDEFNUM: 1089 obj->verdefnum = dynp->d_un.d_val; 1090 break; 1091 1092 case DT_VERSYM: 1093 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1094 dynp->d_un.d_val); 1095 break; 1096 1097 case DT_HASH: 1098 { 1099 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1100 dynp->d_un.d_ptr); 1101 obj->nbuckets = hashtab[0]; 1102 obj->nchains = hashtab[1]; 1103 obj->buckets = hashtab + 2; 1104 obj->chains = obj->buckets + obj->nbuckets; 1105 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1106 obj->buckets != NULL; 1107 } 1108 break; 1109 1110 case DT_GNU_HASH: 1111 { 1112 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1113 dynp->d_un.d_ptr); 1114 obj->nbuckets_gnu = hashtab[0]; 1115 obj->symndx_gnu = hashtab[1]; 1116 nmaskwords = hashtab[2]; 1117 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1118 obj->maskwords_bm_gnu = nmaskwords - 1; 1119 obj->shift2_gnu = hashtab[3]; 1120 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1121 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1122 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1123 obj->symndx_gnu; 1124 /* Number of bitmask words is required to be power of 2 */ 1125 obj->valid_hash_gnu = powerof2(nmaskwords) && 1126 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1127 } 1128 break; 1129 1130 case DT_NEEDED: 1131 if (!obj->rtld) { 1132 Needed_Entry *nep = NEW(Needed_Entry); 1133 nep->name = dynp->d_un.d_val; 1134 nep->obj = NULL; 1135 nep->next = NULL; 1136 1137 *needed_tail = nep; 1138 needed_tail = &nep->next; 1139 } 1140 break; 1141 1142 case DT_FILTER: 1143 if (!obj->rtld) { 1144 Needed_Entry *nep = NEW(Needed_Entry); 1145 nep->name = dynp->d_un.d_val; 1146 nep->obj = NULL; 1147 nep->next = NULL; 1148 1149 *needed_filtees_tail = nep; 1150 needed_filtees_tail = &nep->next; 1151 } 1152 break; 1153 1154 case DT_AUXILIARY: 1155 if (!obj->rtld) { 1156 Needed_Entry *nep = NEW(Needed_Entry); 1157 nep->name = dynp->d_un.d_val; 1158 nep->obj = NULL; 1159 nep->next = NULL; 1160 1161 *needed_aux_filtees_tail = nep; 1162 needed_aux_filtees_tail = &nep->next; 1163 } 1164 break; 1165 1166 case DT_PLTGOT: 1167 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1168 break; 1169 1170 case DT_TEXTREL: 1171 obj->textrel = true; 1172 break; 1173 1174 case DT_SYMBOLIC: 1175 obj->symbolic = true; 1176 break; 1177 1178 case DT_RPATH: 1179 /* 1180 * We have to wait until later to process this, because we 1181 * might not have gotten the address of the string table yet. 1182 */ 1183 *dyn_rpath = dynp; 1184 break; 1185 1186 case DT_SONAME: 1187 *dyn_soname = dynp; 1188 break; 1189 1190 case DT_RUNPATH: 1191 *dyn_runpath = dynp; 1192 break; 1193 1194 case DT_INIT: 1195 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1196 break; 1197 1198 case DT_PREINIT_ARRAY: 1199 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1200 break; 1201 1202 case DT_PREINIT_ARRAYSZ: 1203 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1204 break; 1205 1206 case DT_INIT_ARRAY: 1207 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1208 break; 1209 1210 case DT_INIT_ARRAYSZ: 1211 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1212 break; 1213 1214 case DT_FINI: 1215 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1216 break; 1217 1218 case DT_FINI_ARRAY: 1219 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1220 break; 1221 1222 case DT_FINI_ARRAYSZ: 1223 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1224 break; 1225 1226 /* 1227 * Don't process DT_DEBUG on MIPS as the dynamic section 1228 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1229 */ 1230 1231 #ifndef __mips__ 1232 case DT_DEBUG: 1233 if (!early) 1234 dbg("Filling in DT_DEBUG entry"); 1235 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1236 break; 1237 #endif 1238 1239 case DT_FLAGS: 1240 if (dynp->d_un.d_val & DF_ORIGIN) 1241 obj->z_origin = true; 1242 if (dynp->d_un.d_val & DF_SYMBOLIC) 1243 obj->symbolic = true; 1244 if (dynp->d_un.d_val & DF_TEXTREL) 1245 obj->textrel = true; 1246 if (dynp->d_un.d_val & DF_BIND_NOW) 1247 obj->bind_now = true; 1248 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1249 ;*/ 1250 break; 1251 #ifdef __mips__ 1252 case DT_MIPS_LOCAL_GOTNO: 1253 obj->local_gotno = dynp->d_un.d_val; 1254 break; 1255 1256 case DT_MIPS_SYMTABNO: 1257 obj->symtabno = dynp->d_un.d_val; 1258 break; 1259 1260 case DT_MIPS_GOTSYM: 1261 obj->gotsym = dynp->d_un.d_val; 1262 break; 1263 1264 case DT_MIPS_RLD_MAP: 1265 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1266 break; 1267 1268 case DT_MIPS_RLD_MAP_REL: 1269 // The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map 1270 // section relative to the address of the tag itself. 1271 *((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) = 1272 (Elf_Addr) &r_debug; 1273 break; 1274 1275 case DT_MIPS_PLTGOT: 1276 obj->mips_pltgot = (Elf_Addr *)(obj->relocbase + 1277 dynp->d_un.d_ptr); 1278 break; 1279 1280 #endif 1281 1282 #ifdef __powerpc64__ 1283 case DT_PPC64_GLINK: 1284 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1285 break; 1286 #endif 1287 1288 case DT_FLAGS_1: 1289 if (dynp->d_un.d_val & DF_1_NOOPEN) 1290 obj->z_noopen = true; 1291 if (dynp->d_un.d_val & DF_1_ORIGIN) 1292 obj->z_origin = true; 1293 if (dynp->d_un.d_val & DF_1_GLOBAL) 1294 obj->z_global = true; 1295 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1296 obj->bind_now = true; 1297 if (dynp->d_un.d_val & DF_1_NODELETE) 1298 obj->z_nodelete = true; 1299 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1300 obj->z_loadfltr = true; 1301 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1302 obj->z_interpose = true; 1303 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1304 obj->z_nodeflib = true; 1305 break; 1306 1307 default: 1308 if (!early) { 1309 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1310 (long)dynp->d_tag); 1311 } 1312 break; 1313 } 1314 } 1315 1316 obj->traced = false; 1317 1318 if (plttype == DT_RELA) { 1319 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1320 obj->pltrel = NULL; 1321 obj->pltrelasize = obj->pltrelsize; 1322 obj->pltrelsize = 0; 1323 } 1324 1325 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1326 if (obj->valid_hash_sysv) 1327 obj->dynsymcount = obj->nchains; 1328 else if (obj->valid_hash_gnu) { 1329 obj->dynsymcount = 0; 1330 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1331 if (obj->buckets_gnu[bkt] == 0) 1332 continue; 1333 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1334 do 1335 obj->dynsymcount++; 1336 while ((*hashval++ & 1u) == 0); 1337 } 1338 obj->dynsymcount += obj->symndx_gnu; 1339 } 1340 } 1341 1342 static bool 1343 obj_resolve_origin(Obj_Entry *obj) 1344 { 1345 1346 if (obj->origin_path != NULL) 1347 return (true); 1348 obj->origin_path = xmalloc(PATH_MAX); 1349 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1350 } 1351 1352 static void 1353 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1354 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1355 { 1356 1357 if (obj->z_origin && !obj_resolve_origin(obj)) 1358 rtld_die(); 1359 1360 if (dyn_runpath != NULL) { 1361 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1362 obj->runpath = origin_subst(obj, obj->runpath); 1363 } else if (dyn_rpath != NULL) { 1364 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1365 obj->rpath = origin_subst(obj, obj->rpath); 1366 } 1367 if (dyn_soname != NULL) 1368 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1369 } 1370 1371 static void 1372 digest_dynamic(Obj_Entry *obj, int early) 1373 { 1374 const Elf_Dyn *dyn_rpath; 1375 const Elf_Dyn *dyn_soname; 1376 const Elf_Dyn *dyn_runpath; 1377 1378 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1379 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1380 } 1381 1382 /* 1383 * Process a shared object's program header. This is used only for the 1384 * main program, when the kernel has already loaded the main program 1385 * into memory before calling the dynamic linker. It creates and 1386 * returns an Obj_Entry structure. 1387 */ 1388 static Obj_Entry * 1389 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1390 { 1391 Obj_Entry *obj; 1392 const Elf_Phdr *phlimit = phdr + phnum; 1393 const Elf_Phdr *ph; 1394 Elf_Addr note_start, note_end; 1395 int nsegs = 0; 1396 1397 obj = obj_new(); 1398 for (ph = phdr; ph < phlimit; ph++) { 1399 if (ph->p_type != PT_PHDR) 1400 continue; 1401 1402 obj->phdr = phdr; 1403 obj->phsize = ph->p_memsz; 1404 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1405 break; 1406 } 1407 1408 obj->stack_flags = PF_X | PF_R | PF_W; 1409 1410 for (ph = phdr; ph < phlimit; ph++) { 1411 switch (ph->p_type) { 1412 1413 case PT_INTERP: 1414 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1415 break; 1416 1417 case PT_LOAD: 1418 if (nsegs == 0) { /* First load segment */ 1419 obj->vaddrbase = trunc_page(ph->p_vaddr); 1420 obj->mapbase = obj->vaddrbase + obj->relocbase; 1421 } else { /* Last load segment */ 1422 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1423 obj->vaddrbase; 1424 } 1425 nsegs++; 1426 break; 1427 1428 case PT_DYNAMIC: 1429 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1430 break; 1431 1432 case PT_TLS: 1433 obj->tlsindex = 1; 1434 obj->tlssize = ph->p_memsz; 1435 obj->tlsalign = ph->p_align; 1436 obj->tlsinitsize = ph->p_filesz; 1437 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1438 break; 1439 1440 case PT_GNU_STACK: 1441 obj->stack_flags = ph->p_flags; 1442 break; 1443 1444 case PT_GNU_RELRO: 1445 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1446 obj->relro_size = round_page(ph->p_memsz); 1447 break; 1448 1449 case PT_NOTE: 1450 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1451 note_end = note_start + ph->p_filesz; 1452 digest_notes(obj, note_start, note_end); 1453 break; 1454 } 1455 } 1456 if (nsegs < 1) { 1457 _rtld_error("%s: too few PT_LOAD segments", path); 1458 return NULL; 1459 } 1460 1461 obj->entry = entry; 1462 return obj; 1463 } 1464 1465 void 1466 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1467 { 1468 const Elf_Note *note; 1469 const char *note_name; 1470 uintptr_t p; 1471 1472 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1473 note = (const Elf_Note *)((const char *)(note + 1) + 1474 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1475 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1476 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1477 note->n_descsz != sizeof(int32_t)) 1478 continue; 1479 if (note->n_type != NT_FREEBSD_ABI_TAG && 1480 note->n_type != NT_FREEBSD_FEATURE_CTL && 1481 note->n_type != NT_FREEBSD_NOINIT_TAG) 1482 continue; 1483 note_name = (const char *)(note + 1); 1484 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1485 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1486 continue; 1487 switch (note->n_type) { 1488 case NT_FREEBSD_ABI_TAG: 1489 /* FreeBSD osrel note */ 1490 p = (uintptr_t)(note + 1); 1491 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1492 obj->osrel = *(const int32_t *)(p); 1493 dbg("note osrel %d", obj->osrel); 1494 break; 1495 case NT_FREEBSD_FEATURE_CTL: 1496 /* FreeBSD ABI feature control note */ 1497 p = (uintptr_t)(note + 1); 1498 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1499 obj->fctl0 = *(const uint32_t *)(p); 1500 dbg("note fctl0 %#x", obj->fctl0); 1501 break; 1502 case NT_FREEBSD_NOINIT_TAG: 1503 /* FreeBSD 'crt does not call init' note */ 1504 obj->crt_no_init = true; 1505 dbg("note crt_no_init"); 1506 break; 1507 } 1508 } 1509 } 1510 1511 static Obj_Entry * 1512 dlcheck(void *handle) 1513 { 1514 Obj_Entry *obj; 1515 1516 TAILQ_FOREACH(obj, &obj_list, next) { 1517 if (obj == (Obj_Entry *) handle) 1518 break; 1519 } 1520 1521 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1522 _rtld_error("Invalid shared object handle %p", handle); 1523 return NULL; 1524 } 1525 return obj; 1526 } 1527 1528 /* 1529 * If the given object is already in the donelist, return true. Otherwise 1530 * add the object to the list and return false. 1531 */ 1532 static bool 1533 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1534 { 1535 unsigned int i; 1536 1537 for (i = 0; i < dlp->num_used; i++) 1538 if (dlp->objs[i] == obj) 1539 return true; 1540 /* 1541 * Our donelist allocation should always be sufficient. But if 1542 * our threads locking isn't working properly, more shared objects 1543 * could have been loaded since we allocated the list. That should 1544 * never happen, but we'll handle it properly just in case it does. 1545 */ 1546 if (dlp->num_used < dlp->num_alloc) 1547 dlp->objs[dlp->num_used++] = obj; 1548 return false; 1549 } 1550 1551 /* 1552 * Hash function for symbol table lookup. Don't even think about changing 1553 * this. It is specified by the System V ABI. 1554 */ 1555 unsigned long 1556 elf_hash(const char *name) 1557 { 1558 const unsigned char *p = (const unsigned char *) name; 1559 unsigned long h = 0; 1560 unsigned long g; 1561 1562 while (*p != '\0') { 1563 h = (h << 4) + *p++; 1564 if ((g = h & 0xf0000000) != 0) 1565 h ^= g >> 24; 1566 h &= ~g; 1567 } 1568 return h; 1569 } 1570 1571 /* 1572 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1573 * unsigned in case it's implemented with a wider type. 1574 */ 1575 static uint32_t 1576 gnu_hash(const char *s) 1577 { 1578 uint32_t h; 1579 unsigned char c; 1580 1581 h = 5381; 1582 for (c = *s; c != '\0'; c = *++s) 1583 h = h * 33 + c; 1584 return (h & 0xffffffff); 1585 } 1586 1587 1588 /* 1589 * Find the library with the given name, and return its full pathname. 1590 * The returned string is dynamically allocated. Generates an error 1591 * message and returns NULL if the library cannot be found. 1592 * 1593 * If the second argument is non-NULL, then it refers to an already- 1594 * loaded shared object, whose library search path will be searched. 1595 * 1596 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1597 * descriptor (which is close-on-exec) will be passed out via the third 1598 * argument. 1599 * 1600 * The search order is: 1601 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1602 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1603 * LD_LIBRARY_PATH 1604 * DT_RUNPATH in the referencing file 1605 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1606 * from list) 1607 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1608 * 1609 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1610 */ 1611 static char * 1612 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1613 { 1614 char *pathname, *refobj_path; 1615 const char *name; 1616 bool nodeflib, objgiven; 1617 1618 objgiven = refobj != NULL; 1619 1620 if (libmap_disable || !objgiven || 1621 (name = lm_find(refobj->path, xname)) == NULL) 1622 name = xname; 1623 1624 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1625 if (name[0] != '/' && !trust) { 1626 _rtld_error("Absolute pathname required " 1627 "for shared object \"%s\"", name); 1628 return (NULL); 1629 } 1630 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1631 __DECONST(char *, name))); 1632 } 1633 1634 dbg(" Searching for \"%s\"", name); 1635 refobj_path = objgiven ? refobj->path : NULL; 1636 1637 /* 1638 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1639 * back to pre-conforming behaviour if user requested so with 1640 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1641 * nodeflib. 1642 */ 1643 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1644 pathname = search_library_path(name, ld_library_path, 1645 refobj_path, fdp); 1646 if (pathname != NULL) 1647 return (pathname); 1648 if (refobj != NULL) { 1649 pathname = search_library_path(name, refobj->rpath, 1650 refobj_path, fdp); 1651 if (pathname != NULL) 1652 return (pathname); 1653 } 1654 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1655 if (pathname != NULL) 1656 return (pathname); 1657 pathname = search_library_path(name, gethints(false), 1658 refobj_path, fdp); 1659 if (pathname != NULL) 1660 return (pathname); 1661 pathname = search_library_path(name, ld_standard_library_path, 1662 refobj_path, fdp); 1663 if (pathname != NULL) 1664 return (pathname); 1665 } else { 1666 nodeflib = objgiven ? refobj->z_nodeflib : false; 1667 if (objgiven) { 1668 pathname = search_library_path(name, refobj->rpath, 1669 refobj->path, fdp); 1670 if (pathname != NULL) 1671 return (pathname); 1672 } 1673 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1674 pathname = search_library_path(name, obj_main->rpath, 1675 refobj_path, fdp); 1676 if (pathname != NULL) 1677 return (pathname); 1678 } 1679 pathname = search_library_path(name, ld_library_path, 1680 refobj_path, fdp); 1681 if (pathname != NULL) 1682 return (pathname); 1683 if (objgiven) { 1684 pathname = search_library_path(name, refobj->runpath, 1685 refobj_path, fdp); 1686 if (pathname != NULL) 1687 return (pathname); 1688 } 1689 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1690 if (pathname != NULL) 1691 return (pathname); 1692 pathname = search_library_path(name, gethints(nodeflib), 1693 refobj_path, fdp); 1694 if (pathname != NULL) 1695 return (pathname); 1696 if (objgiven && !nodeflib) { 1697 pathname = search_library_path(name, 1698 ld_standard_library_path, refobj_path, fdp); 1699 if (pathname != NULL) 1700 return (pathname); 1701 } 1702 } 1703 1704 if (objgiven && refobj->path != NULL) { 1705 _rtld_error("Shared object \"%s\" not found, " 1706 "required by \"%s\"", name, basename(refobj->path)); 1707 } else { 1708 _rtld_error("Shared object \"%s\" not found", name); 1709 } 1710 return (NULL); 1711 } 1712 1713 /* 1714 * Given a symbol number in a referencing object, find the corresponding 1715 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1716 * no definition was found. Returns a pointer to the Obj_Entry of the 1717 * defining object via the reference parameter DEFOBJ_OUT. 1718 */ 1719 const Elf_Sym * 1720 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1721 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1722 RtldLockState *lockstate) 1723 { 1724 const Elf_Sym *ref; 1725 const Elf_Sym *def; 1726 const Obj_Entry *defobj; 1727 const Ver_Entry *ve; 1728 SymLook req; 1729 const char *name; 1730 int res; 1731 1732 /* 1733 * If we have already found this symbol, get the information from 1734 * the cache. 1735 */ 1736 if (symnum >= refobj->dynsymcount) 1737 return NULL; /* Bad object */ 1738 if (cache != NULL && cache[symnum].sym != NULL) { 1739 *defobj_out = cache[symnum].obj; 1740 return cache[symnum].sym; 1741 } 1742 1743 ref = refobj->symtab + symnum; 1744 name = refobj->strtab + ref->st_name; 1745 def = NULL; 1746 defobj = NULL; 1747 ve = NULL; 1748 1749 /* 1750 * We don't have to do a full scale lookup if the symbol is local. 1751 * We know it will bind to the instance in this load module; to 1752 * which we already have a pointer (ie ref). By not doing a lookup, 1753 * we not only improve performance, but it also avoids unresolvable 1754 * symbols when local symbols are not in the hash table. This has 1755 * been seen with the ia64 toolchain. 1756 */ 1757 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1758 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1759 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1760 symnum); 1761 } 1762 symlook_init(&req, name); 1763 req.flags = flags; 1764 ve = req.ventry = fetch_ventry(refobj, symnum); 1765 req.lockstate = lockstate; 1766 res = symlook_default(&req, refobj); 1767 if (res == 0) { 1768 def = req.sym_out; 1769 defobj = req.defobj_out; 1770 } 1771 } else { 1772 def = ref; 1773 defobj = refobj; 1774 } 1775 1776 /* 1777 * If we found no definition and the reference is weak, treat the 1778 * symbol as having the value zero. 1779 */ 1780 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1781 def = &sym_zero; 1782 defobj = obj_main; 1783 } 1784 1785 if (def != NULL) { 1786 *defobj_out = defobj; 1787 /* Record the information in the cache to avoid subsequent lookups. */ 1788 if (cache != NULL) { 1789 cache[symnum].sym = def; 1790 cache[symnum].obj = defobj; 1791 } 1792 } else { 1793 if (refobj != &obj_rtld) 1794 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1795 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1796 } 1797 return def; 1798 } 1799 1800 /* 1801 * Return the search path from the ldconfig hints file, reading it if 1802 * necessary. If nostdlib is true, then the default search paths are 1803 * not added to result. 1804 * 1805 * Returns NULL if there are problems with the hints file, 1806 * or if the search path there is empty. 1807 */ 1808 static const char * 1809 gethints(bool nostdlib) 1810 { 1811 static char *filtered_path; 1812 static const char *hints; 1813 static struct elfhints_hdr hdr; 1814 struct fill_search_info_args sargs, hargs; 1815 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1816 struct dl_serpath *SLPpath, *hintpath; 1817 char *p; 1818 struct stat hint_stat; 1819 unsigned int SLPndx, hintndx, fndx, fcount; 1820 int fd; 1821 size_t flen; 1822 uint32_t dl; 1823 bool skip; 1824 1825 /* First call, read the hints file */ 1826 if (hints == NULL) { 1827 /* Keep from trying again in case the hints file is bad. */ 1828 hints = ""; 1829 1830 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1831 return (NULL); 1832 1833 /* 1834 * Check of hdr.dirlistlen value against type limit 1835 * intends to pacify static analyzers. Further 1836 * paranoia leads to checks that dirlist is fully 1837 * contained in the file range. 1838 */ 1839 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1840 hdr.magic != ELFHINTS_MAGIC || 1841 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1842 fstat(fd, &hint_stat) == -1) { 1843 cleanup1: 1844 close(fd); 1845 hdr.dirlistlen = 0; 1846 return (NULL); 1847 } 1848 dl = hdr.strtab; 1849 if (dl + hdr.dirlist < dl) 1850 goto cleanup1; 1851 dl += hdr.dirlist; 1852 if (dl + hdr.dirlistlen < dl) 1853 goto cleanup1; 1854 dl += hdr.dirlistlen; 1855 if (dl > hint_stat.st_size) 1856 goto cleanup1; 1857 p = xmalloc(hdr.dirlistlen + 1); 1858 if (pread(fd, p, hdr.dirlistlen + 1, 1859 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1860 p[hdr.dirlistlen] != '\0') { 1861 free(p); 1862 goto cleanup1; 1863 } 1864 hints = p; 1865 close(fd); 1866 } 1867 1868 /* 1869 * If caller agreed to receive list which includes the default 1870 * paths, we are done. Otherwise, if we still did not 1871 * calculated filtered result, do it now. 1872 */ 1873 if (!nostdlib) 1874 return (hints[0] != '\0' ? hints : NULL); 1875 if (filtered_path != NULL) 1876 goto filt_ret; 1877 1878 /* 1879 * Obtain the list of all configured search paths, and the 1880 * list of the default paths. 1881 * 1882 * First estimate the size of the results. 1883 */ 1884 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1885 smeta.dls_cnt = 0; 1886 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1887 hmeta.dls_cnt = 0; 1888 1889 sargs.request = RTLD_DI_SERINFOSIZE; 1890 sargs.serinfo = &smeta; 1891 hargs.request = RTLD_DI_SERINFOSIZE; 1892 hargs.serinfo = &hmeta; 1893 1894 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1895 &sargs); 1896 path_enumerate(hints, fill_search_info, NULL, &hargs); 1897 1898 SLPinfo = xmalloc(smeta.dls_size); 1899 hintinfo = xmalloc(hmeta.dls_size); 1900 1901 /* 1902 * Next fetch both sets of paths. 1903 */ 1904 sargs.request = RTLD_DI_SERINFO; 1905 sargs.serinfo = SLPinfo; 1906 sargs.serpath = &SLPinfo->dls_serpath[0]; 1907 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1908 1909 hargs.request = RTLD_DI_SERINFO; 1910 hargs.serinfo = hintinfo; 1911 hargs.serpath = &hintinfo->dls_serpath[0]; 1912 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1913 1914 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1915 &sargs); 1916 path_enumerate(hints, fill_search_info, NULL, &hargs); 1917 1918 /* 1919 * Now calculate the difference between two sets, by excluding 1920 * standard paths from the full set. 1921 */ 1922 fndx = 0; 1923 fcount = 0; 1924 filtered_path = xmalloc(hdr.dirlistlen + 1); 1925 hintpath = &hintinfo->dls_serpath[0]; 1926 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1927 skip = false; 1928 SLPpath = &SLPinfo->dls_serpath[0]; 1929 /* 1930 * Check each standard path against current. 1931 */ 1932 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1933 /* matched, skip the path */ 1934 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1935 skip = true; 1936 break; 1937 } 1938 } 1939 if (skip) 1940 continue; 1941 /* 1942 * Not matched against any standard path, add the path 1943 * to result. Separate consequtive paths with ':'. 1944 */ 1945 if (fcount > 0) { 1946 filtered_path[fndx] = ':'; 1947 fndx++; 1948 } 1949 fcount++; 1950 flen = strlen(hintpath->dls_name); 1951 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1952 fndx += flen; 1953 } 1954 filtered_path[fndx] = '\0'; 1955 1956 free(SLPinfo); 1957 free(hintinfo); 1958 1959 filt_ret: 1960 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1961 } 1962 1963 static void 1964 init_dag(Obj_Entry *root) 1965 { 1966 const Needed_Entry *needed; 1967 const Objlist_Entry *elm; 1968 DoneList donelist; 1969 1970 if (root->dag_inited) 1971 return; 1972 donelist_init(&donelist); 1973 1974 /* Root object belongs to own DAG. */ 1975 objlist_push_tail(&root->dldags, root); 1976 objlist_push_tail(&root->dagmembers, root); 1977 donelist_check(&donelist, root); 1978 1979 /* 1980 * Add dependencies of root object to DAG in breadth order 1981 * by exploiting the fact that each new object get added 1982 * to the tail of the dagmembers list. 1983 */ 1984 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1985 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1986 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1987 continue; 1988 objlist_push_tail(&needed->obj->dldags, root); 1989 objlist_push_tail(&root->dagmembers, needed->obj); 1990 } 1991 } 1992 root->dag_inited = true; 1993 } 1994 1995 static void 1996 init_marker(Obj_Entry *marker) 1997 { 1998 1999 bzero(marker, sizeof(*marker)); 2000 marker->marker = true; 2001 } 2002 2003 Obj_Entry * 2004 globallist_curr(const Obj_Entry *obj) 2005 { 2006 2007 for (;;) { 2008 if (obj == NULL) 2009 return (NULL); 2010 if (!obj->marker) 2011 return (__DECONST(Obj_Entry *, obj)); 2012 obj = TAILQ_PREV(obj, obj_entry_q, next); 2013 } 2014 } 2015 2016 Obj_Entry * 2017 globallist_next(const Obj_Entry *obj) 2018 { 2019 2020 for (;;) { 2021 obj = TAILQ_NEXT(obj, next); 2022 if (obj == NULL) 2023 return (NULL); 2024 if (!obj->marker) 2025 return (__DECONST(Obj_Entry *, obj)); 2026 } 2027 } 2028 2029 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2030 static void 2031 hold_object(Obj_Entry *obj) 2032 { 2033 2034 obj->holdcount++; 2035 } 2036 2037 static void 2038 unhold_object(Obj_Entry *obj) 2039 { 2040 2041 assert(obj->holdcount > 0); 2042 if (--obj->holdcount == 0 && obj->unholdfree) 2043 release_object(obj); 2044 } 2045 2046 static void 2047 process_z(Obj_Entry *root) 2048 { 2049 const Objlist_Entry *elm; 2050 Obj_Entry *obj; 2051 2052 /* 2053 * Walk over object DAG and process every dependent object 2054 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2055 * to grow their own DAG. 2056 * 2057 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2058 * symlook_global() to work. 2059 * 2060 * For DF_1_NODELETE, the DAG should have its reference upped. 2061 */ 2062 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2063 obj = elm->obj; 2064 if (obj == NULL) 2065 continue; 2066 if (obj->z_nodelete && !obj->ref_nodel) { 2067 dbg("obj %s -z nodelete", obj->path); 2068 init_dag(obj); 2069 ref_dag(obj); 2070 obj->ref_nodel = true; 2071 } 2072 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2073 dbg("obj %s -z global", obj->path); 2074 objlist_push_tail(&list_global, obj); 2075 init_dag(obj); 2076 } 2077 } 2078 } 2079 /* 2080 * Initialize the dynamic linker. The argument is the address at which 2081 * the dynamic linker has been mapped into memory. The primary task of 2082 * this function is to relocate the dynamic linker. 2083 */ 2084 static void 2085 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2086 { 2087 Obj_Entry objtmp; /* Temporary rtld object */ 2088 const Elf_Ehdr *ehdr; 2089 const Elf_Dyn *dyn_rpath; 2090 const Elf_Dyn *dyn_soname; 2091 const Elf_Dyn *dyn_runpath; 2092 2093 #ifdef RTLD_INIT_PAGESIZES_EARLY 2094 /* The page size is required by the dynamic memory allocator. */ 2095 init_pagesizes(aux_info); 2096 #endif 2097 2098 /* 2099 * Conjure up an Obj_Entry structure for the dynamic linker. 2100 * 2101 * The "path" member can't be initialized yet because string constants 2102 * cannot yet be accessed. Below we will set it correctly. 2103 */ 2104 memset(&objtmp, 0, sizeof(objtmp)); 2105 objtmp.path = NULL; 2106 objtmp.rtld = true; 2107 objtmp.mapbase = mapbase; 2108 #ifdef PIC 2109 objtmp.relocbase = mapbase; 2110 #endif 2111 2112 objtmp.dynamic = rtld_dynamic(&objtmp); 2113 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2114 assert(objtmp.needed == NULL); 2115 #if !defined(__mips__) 2116 /* MIPS has a bogus DT_TEXTREL. */ 2117 assert(!objtmp.textrel); 2118 #endif 2119 /* 2120 * Temporarily put the dynamic linker entry into the object list, so 2121 * that symbols can be found. 2122 */ 2123 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2124 2125 ehdr = (Elf_Ehdr *)mapbase; 2126 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2127 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2128 2129 /* Initialize the object list. */ 2130 TAILQ_INIT(&obj_list); 2131 2132 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2133 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2134 2135 #ifndef RTLD_INIT_PAGESIZES_EARLY 2136 /* The page size is required by the dynamic memory allocator. */ 2137 init_pagesizes(aux_info); 2138 #endif 2139 2140 if (aux_info[AT_OSRELDATE] != NULL) 2141 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2142 2143 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2144 2145 /* Replace the path with a dynamically allocated copy. */ 2146 obj_rtld.path = xstrdup(ld_path_rtld); 2147 2148 r_debug.r_brk = r_debug_state; 2149 r_debug.r_state = RT_CONSISTENT; 2150 } 2151 2152 /* 2153 * Retrieve the array of supported page sizes. The kernel provides the page 2154 * sizes in increasing order. 2155 */ 2156 static void 2157 init_pagesizes(Elf_Auxinfo **aux_info) 2158 { 2159 static size_t psa[MAXPAGESIZES]; 2160 int mib[2]; 2161 size_t len, size; 2162 2163 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2164 NULL) { 2165 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2166 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2167 } else { 2168 len = 2; 2169 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2170 size = sizeof(psa); 2171 else { 2172 /* As a fallback, retrieve the base page size. */ 2173 size = sizeof(psa[0]); 2174 if (aux_info[AT_PAGESZ] != NULL) { 2175 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2176 goto psa_filled; 2177 } else { 2178 mib[0] = CTL_HW; 2179 mib[1] = HW_PAGESIZE; 2180 len = 2; 2181 } 2182 } 2183 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2184 _rtld_error("sysctl for hw.pagesize(s) failed"); 2185 rtld_die(); 2186 } 2187 psa_filled: 2188 pagesizes = psa; 2189 } 2190 npagesizes = size / sizeof(pagesizes[0]); 2191 /* Discard any invalid entries at the end of the array. */ 2192 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2193 npagesizes--; 2194 } 2195 2196 /* 2197 * Add the init functions from a needed object list (and its recursive 2198 * needed objects) to "list". This is not used directly; it is a helper 2199 * function for initlist_add_objects(). The write lock must be held 2200 * when this function is called. 2201 */ 2202 static void 2203 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2204 { 2205 /* Recursively process the successor needed objects. */ 2206 if (needed->next != NULL) 2207 initlist_add_neededs(needed->next, list); 2208 2209 /* Process the current needed object. */ 2210 if (needed->obj != NULL) 2211 initlist_add_objects(needed->obj, needed->obj, list); 2212 } 2213 2214 /* 2215 * Scan all of the DAGs rooted in the range of objects from "obj" to 2216 * "tail" and add their init functions to "list". This recurses over 2217 * the DAGs and ensure the proper init ordering such that each object's 2218 * needed libraries are initialized before the object itself. At the 2219 * same time, this function adds the objects to the global finalization 2220 * list "list_fini" in the opposite order. The write lock must be 2221 * held when this function is called. 2222 */ 2223 static void 2224 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2225 { 2226 Obj_Entry *nobj; 2227 2228 if (obj->init_scanned || obj->init_done) 2229 return; 2230 obj->init_scanned = true; 2231 2232 /* Recursively process the successor objects. */ 2233 nobj = globallist_next(obj); 2234 if (nobj != NULL && obj != tail) 2235 initlist_add_objects(nobj, tail, list); 2236 2237 /* Recursively process the needed objects. */ 2238 if (obj->needed != NULL) 2239 initlist_add_neededs(obj->needed, list); 2240 if (obj->needed_filtees != NULL) 2241 initlist_add_neededs(obj->needed_filtees, list); 2242 if (obj->needed_aux_filtees != NULL) 2243 initlist_add_neededs(obj->needed_aux_filtees, list); 2244 2245 /* Add the object to the init list. */ 2246 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 2247 obj->init_array != (Elf_Addr)NULL) 2248 objlist_push_tail(list, obj); 2249 2250 /* Add the object to the global fini list in the reverse order. */ 2251 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2252 && !obj->on_fini_list) { 2253 objlist_push_head(&list_fini, obj); 2254 obj->on_fini_list = true; 2255 } 2256 } 2257 2258 #ifndef FPTR_TARGET 2259 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2260 #endif 2261 2262 static void 2263 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2264 { 2265 Needed_Entry *needed, *needed1; 2266 2267 for (needed = n; needed != NULL; needed = needed->next) { 2268 if (needed->obj != NULL) { 2269 dlclose_locked(needed->obj, lockstate); 2270 needed->obj = NULL; 2271 } 2272 } 2273 for (needed = n; needed != NULL; needed = needed1) { 2274 needed1 = needed->next; 2275 free(needed); 2276 } 2277 } 2278 2279 static void 2280 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2281 { 2282 2283 free_needed_filtees(obj->needed_filtees, lockstate); 2284 obj->needed_filtees = NULL; 2285 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2286 obj->needed_aux_filtees = NULL; 2287 obj->filtees_loaded = false; 2288 } 2289 2290 static void 2291 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2292 RtldLockState *lockstate) 2293 { 2294 2295 for (; needed != NULL; needed = needed->next) { 2296 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2297 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2298 RTLD_LOCAL, lockstate); 2299 } 2300 } 2301 2302 static void 2303 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2304 { 2305 2306 lock_restart_for_upgrade(lockstate); 2307 if (!obj->filtees_loaded) { 2308 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2309 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2310 obj->filtees_loaded = true; 2311 } 2312 } 2313 2314 static int 2315 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2316 { 2317 Obj_Entry *obj1; 2318 2319 for (; needed != NULL; needed = needed->next) { 2320 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2321 flags & ~RTLD_LO_NOLOAD); 2322 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2323 return (-1); 2324 } 2325 return (0); 2326 } 2327 2328 /* 2329 * Given a shared object, traverse its list of needed objects, and load 2330 * each of them. Returns 0 on success. Generates an error message and 2331 * returns -1 on failure. 2332 */ 2333 static int 2334 load_needed_objects(Obj_Entry *first, int flags) 2335 { 2336 Obj_Entry *obj; 2337 2338 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2339 if (obj->marker) 2340 continue; 2341 if (process_needed(obj, obj->needed, flags) == -1) 2342 return (-1); 2343 } 2344 return (0); 2345 } 2346 2347 static int 2348 load_preload_objects(void) 2349 { 2350 char *p = ld_preload; 2351 Obj_Entry *obj; 2352 static const char delim[] = " \t:;"; 2353 2354 if (p == NULL) 2355 return 0; 2356 2357 p += strspn(p, delim); 2358 while (*p != '\0') { 2359 size_t len = strcspn(p, delim); 2360 char savech; 2361 2362 savech = p[len]; 2363 p[len] = '\0'; 2364 obj = load_object(p, -1, NULL, 0); 2365 if (obj == NULL) 2366 return -1; /* XXX - cleanup */ 2367 obj->z_interpose = true; 2368 p[len] = savech; 2369 p += len; 2370 p += strspn(p, delim); 2371 } 2372 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2373 return 0; 2374 } 2375 2376 static const char * 2377 printable_path(const char *path) 2378 { 2379 2380 return (path == NULL ? "<unknown>" : path); 2381 } 2382 2383 /* 2384 * Load a shared object into memory, if it is not already loaded. The 2385 * object may be specified by name or by user-supplied file descriptor 2386 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2387 * duplicate is. 2388 * 2389 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2390 * on failure. 2391 */ 2392 static Obj_Entry * 2393 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2394 { 2395 Obj_Entry *obj; 2396 int fd; 2397 struct stat sb; 2398 char *path; 2399 2400 fd = -1; 2401 if (name != NULL) { 2402 TAILQ_FOREACH(obj, &obj_list, next) { 2403 if (obj->marker || obj->doomed) 2404 continue; 2405 if (object_match_name(obj, name)) 2406 return (obj); 2407 } 2408 2409 path = find_library(name, refobj, &fd); 2410 if (path == NULL) 2411 return (NULL); 2412 } else 2413 path = NULL; 2414 2415 if (fd >= 0) { 2416 /* 2417 * search_library_pathfds() opens a fresh file descriptor for the 2418 * library, so there is no need to dup(). 2419 */ 2420 } else if (fd_u == -1) { 2421 /* 2422 * If we didn't find a match by pathname, or the name is not 2423 * supplied, open the file and check again by device and inode. 2424 * This avoids false mismatches caused by multiple links or ".." 2425 * in pathnames. 2426 * 2427 * To avoid a race, we open the file and use fstat() rather than 2428 * using stat(). 2429 */ 2430 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2431 _rtld_error("Cannot open \"%s\"", path); 2432 free(path); 2433 return (NULL); 2434 } 2435 } else { 2436 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2437 if (fd == -1) { 2438 _rtld_error("Cannot dup fd"); 2439 free(path); 2440 return (NULL); 2441 } 2442 } 2443 if (fstat(fd, &sb) == -1) { 2444 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2445 close(fd); 2446 free(path); 2447 return NULL; 2448 } 2449 TAILQ_FOREACH(obj, &obj_list, next) { 2450 if (obj->marker || obj->doomed) 2451 continue; 2452 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2453 break; 2454 } 2455 if (obj != NULL && name != NULL) { 2456 object_add_name(obj, name); 2457 free(path); 2458 close(fd); 2459 return obj; 2460 } 2461 if (flags & RTLD_LO_NOLOAD) { 2462 free(path); 2463 close(fd); 2464 return (NULL); 2465 } 2466 2467 /* First use of this object, so we must map it in */ 2468 obj = do_load_object(fd, name, path, &sb, flags); 2469 if (obj == NULL) 2470 free(path); 2471 close(fd); 2472 2473 return obj; 2474 } 2475 2476 static Obj_Entry * 2477 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2478 int flags) 2479 { 2480 Obj_Entry *obj; 2481 struct statfs fs; 2482 2483 /* 2484 * but first, make sure that environment variables haven't been 2485 * used to circumvent the noexec flag on a filesystem. 2486 */ 2487 if (dangerous_ld_env) { 2488 if (fstatfs(fd, &fs) != 0) { 2489 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2490 return NULL; 2491 } 2492 if (fs.f_flags & MNT_NOEXEC) { 2493 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2494 return NULL; 2495 } 2496 } 2497 dbg("loading \"%s\"", printable_path(path)); 2498 obj = map_object(fd, printable_path(path), sbp); 2499 if (obj == NULL) 2500 return NULL; 2501 2502 /* 2503 * If DT_SONAME is present in the object, digest_dynamic2 already 2504 * added it to the object names. 2505 */ 2506 if (name != NULL) 2507 object_add_name(obj, name); 2508 obj->path = path; 2509 digest_dynamic(obj, 0); 2510 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2511 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2512 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2513 RTLD_LO_DLOPEN) { 2514 dbg("refusing to load non-loadable \"%s\"", obj->path); 2515 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2516 munmap(obj->mapbase, obj->mapsize); 2517 obj_free(obj); 2518 return (NULL); 2519 } 2520 2521 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2522 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2523 obj_count++; 2524 obj_loads++; 2525 linkmap_add(obj); /* for GDB & dlinfo() */ 2526 max_stack_flags |= obj->stack_flags; 2527 2528 dbg(" %p .. %p: %s", obj->mapbase, 2529 obj->mapbase + obj->mapsize - 1, obj->path); 2530 if (obj->textrel) 2531 dbg(" WARNING: %s has impure text", obj->path); 2532 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2533 obj->path); 2534 2535 return obj; 2536 } 2537 2538 static Obj_Entry * 2539 obj_from_addr(const void *addr) 2540 { 2541 Obj_Entry *obj; 2542 2543 TAILQ_FOREACH(obj, &obj_list, next) { 2544 if (obj->marker) 2545 continue; 2546 if (addr < (void *) obj->mapbase) 2547 continue; 2548 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2549 return obj; 2550 } 2551 return NULL; 2552 } 2553 2554 static void 2555 preinit_main(void) 2556 { 2557 Elf_Addr *preinit_addr; 2558 int index; 2559 2560 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2561 if (preinit_addr == NULL) 2562 return; 2563 2564 for (index = 0; index < obj_main->preinit_array_num; index++) { 2565 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2566 dbg("calling preinit function for %s at %p", obj_main->path, 2567 (void *)preinit_addr[index]); 2568 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2569 0, 0, obj_main->path); 2570 call_init_pointer(obj_main, preinit_addr[index]); 2571 } 2572 } 2573 } 2574 2575 /* 2576 * Call the finalization functions for each of the objects in "list" 2577 * belonging to the DAG of "root" and referenced once. If NULL "root" 2578 * is specified, every finalization function will be called regardless 2579 * of the reference count and the list elements won't be freed. All of 2580 * the objects are expected to have non-NULL fini functions. 2581 */ 2582 static void 2583 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2584 { 2585 Objlist_Entry *elm; 2586 char *saved_msg; 2587 Elf_Addr *fini_addr; 2588 int index; 2589 2590 assert(root == NULL || root->refcount == 1); 2591 2592 if (root != NULL) 2593 root->doomed = true; 2594 2595 /* 2596 * Preserve the current error message since a fini function might 2597 * call into the dynamic linker and overwrite it. 2598 */ 2599 saved_msg = errmsg_save(); 2600 do { 2601 STAILQ_FOREACH(elm, list, link) { 2602 if (root != NULL && (elm->obj->refcount != 1 || 2603 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2604 continue; 2605 /* Remove object from fini list to prevent recursive invocation. */ 2606 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2607 /* Ensure that new references cannot be acquired. */ 2608 elm->obj->doomed = true; 2609 2610 hold_object(elm->obj); 2611 lock_release(rtld_bind_lock, lockstate); 2612 /* 2613 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2614 * When this happens, DT_FINI_ARRAY is processed first. 2615 */ 2616 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2617 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2618 for (index = elm->obj->fini_array_num - 1; index >= 0; 2619 index--) { 2620 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2621 dbg("calling fini function for %s at %p", 2622 elm->obj->path, (void *)fini_addr[index]); 2623 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2624 (void *)fini_addr[index], 0, 0, elm->obj->path); 2625 call_initfini_pointer(elm->obj, fini_addr[index]); 2626 } 2627 } 2628 } 2629 if (elm->obj->fini != (Elf_Addr)NULL) { 2630 dbg("calling fini function for %s at %p", elm->obj->path, 2631 (void *)elm->obj->fini); 2632 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2633 0, 0, elm->obj->path); 2634 call_initfini_pointer(elm->obj, elm->obj->fini); 2635 } 2636 wlock_acquire(rtld_bind_lock, lockstate); 2637 unhold_object(elm->obj); 2638 /* No need to free anything if process is going down. */ 2639 if (root != NULL) 2640 free(elm); 2641 /* 2642 * We must restart the list traversal after every fini call 2643 * because a dlclose() call from the fini function or from 2644 * another thread might have modified the reference counts. 2645 */ 2646 break; 2647 } 2648 } while (elm != NULL); 2649 errmsg_restore(saved_msg); 2650 } 2651 2652 /* 2653 * Call the initialization functions for each of the objects in 2654 * "list". All of the objects are expected to have non-NULL init 2655 * functions. 2656 */ 2657 static void 2658 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2659 { 2660 Objlist_Entry *elm; 2661 Obj_Entry *obj; 2662 char *saved_msg; 2663 Elf_Addr *init_addr; 2664 int index; 2665 2666 /* 2667 * Clean init_scanned flag so that objects can be rechecked and 2668 * possibly initialized earlier if any of vectors called below 2669 * cause the change by using dlopen. 2670 */ 2671 TAILQ_FOREACH(obj, &obj_list, next) { 2672 if (obj->marker) 2673 continue; 2674 obj->init_scanned = false; 2675 } 2676 2677 /* 2678 * Preserve the current error message since an init function might 2679 * call into the dynamic linker and overwrite it. 2680 */ 2681 saved_msg = errmsg_save(); 2682 STAILQ_FOREACH(elm, list, link) { 2683 if (elm->obj->init_done) /* Initialized early. */ 2684 continue; 2685 /* 2686 * Race: other thread might try to use this object before current 2687 * one completes the initialization. Not much can be done here 2688 * without better locking. 2689 */ 2690 elm->obj->init_done = true; 2691 hold_object(elm->obj); 2692 lock_release(rtld_bind_lock, lockstate); 2693 2694 /* 2695 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2696 * When this happens, DT_INIT is processed first. 2697 */ 2698 if (elm->obj->init != (Elf_Addr)NULL) { 2699 dbg("calling init function for %s at %p", elm->obj->path, 2700 (void *)elm->obj->init); 2701 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2702 0, 0, elm->obj->path); 2703 call_initfini_pointer(elm->obj, elm->obj->init); 2704 } 2705 init_addr = (Elf_Addr *)elm->obj->init_array; 2706 if (init_addr != NULL) { 2707 for (index = 0; index < elm->obj->init_array_num; index++) { 2708 if (init_addr[index] != 0 && init_addr[index] != 1) { 2709 dbg("calling init function for %s at %p", elm->obj->path, 2710 (void *)init_addr[index]); 2711 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2712 (void *)init_addr[index], 0, 0, elm->obj->path); 2713 call_init_pointer(elm->obj, init_addr[index]); 2714 } 2715 } 2716 } 2717 wlock_acquire(rtld_bind_lock, lockstate); 2718 unhold_object(elm->obj); 2719 } 2720 errmsg_restore(saved_msg); 2721 } 2722 2723 static void 2724 objlist_clear(Objlist *list) 2725 { 2726 Objlist_Entry *elm; 2727 2728 while (!STAILQ_EMPTY(list)) { 2729 elm = STAILQ_FIRST(list); 2730 STAILQ_REMOVE_HEAD(list, link); 2731 free(elm); 2732 } 2733 } 2734 2735 static Objlist_Entry * 2736 objlist_find(Objlist *list, const Obj_Entry *obj) 2737 { 2738 Objlist_Entry *elm; 2739 2740 STAILQ_FOREACH(elm, list, link) 2741 if (elm->obj == obj) 2742 return elm; 2743 return NULL; 2744 } 2745 2746 static void 2747 objlist_init(Objlist *list) 2748 { 2749 STAILQ_INIT(list); 2750 } 2751 2752 static void 2753 objlist_push_head(Objlist *list, Obj_Entry *obj) 2754 { 2755 Objlist_Entry *elm; 2756 2757 elm = NEW(Objlist_Entry); 2758 elm->obj = obj; 2759 STAILQ_INSERT_HEAD(list, elm, link); 2760 } 2761 2762 static void 2763 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2764 { 2765 Objlist_Entry *elm; 2766 2767 elm = NEW(Objlist_Entry); 2768 elm->obj = obj; 2769 STAILQ_INSERT_TAIL(list, elm, link); 2770 } 2771 2772 static void 2773 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2774 { 2775 Objlist_Entry *elm, *listelm; 2776 2777 STAILQ_FOREACH(listelm, list, link) { 2778 if (listelm->obj == listobj) 2779 break; 2780 } 2781 elm = NEW(Objlist_Entry); 2782 elm->obj = obj; 2783 if (listelm != NULL) 2784 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2785 else 2786 STAILQ_INSERT_TAIL(list, elm, link); 2787 } 2788 2789 static void 2790 objlist_remove(Objlist *list, Obj_Entry *obj) 2791 { 2792 Objlist_Entry *elm; 2793 2794 if ((elm = objlist_find(list, obj)) != NULL) { 2795 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2796 free(elm); 2797 } 2798 } 2799 2800 /* 2801 * Relocate dag rooted in the specified object. 2802 * Returns 0 on success, or -1 on failure. 2803 */ 2804 2805 static int 2806 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2807 int flags, RtldLockState *lockstate) 2808 { 2809 Objlist_Entry *elm; 2810 int error; 2811 2812 error = 0; 2813 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2814 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2815 lockstate); 2816 if (error == -1) 2817 break; 2818 } 2819 return (error); 2820 } 2821 2822 /* 2823 * Prepare for, or clean after, relocating an object marked with 2824 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 2825 * segments are remapped read-write. After relocations are done, the 2826 * segment's permissions are returned back to the modes specified in 2827 * the phdrs. If any relocation happened, or always for wired 2828 * program, COW is triggered. 2829 */ 2830 static int 2831 reloc_textrel_prot(Obj_Entry *obj, bool before) 2832 { 2833 const Elf_Phdr *ph; 2834 void *base; 2835 size_t l, sz; 2836 int prot; 2837 2838 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 2839 l--, ph++) { 2840 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 2841 continue; 2842 base = obj->relocbase + trunc_page(ph->p_vaddr); 2843 sz = round_page(ph->p_vaddr + ph->p_filesz) - 2844 trunc_page(ph->p_vaddr); 2845 prot = convert_prot(ph->p_flags) | (before ? PROT_WRITE : 0); 2846 if (mprotect(base, sz, prot) == -1) { 2847 _rtld_error("%s: Cannot write-%sable text segment: %s", 2848 obj->path, before ? "en" : "dis", 2849 rtld_strerror(errno)); 2850 return (-1); 2851 } 2852 } 2853 return (0); 2854 } 2855 2856 /* 2857 * Relocate single object. 2858 * Returns 0 on success, or -1 on failure. 2859 */ 2860 static int 2861 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2862 int flags, RtldLockState *lockstate) 2863 { 2864 2865 if (obj->relocated) 2866 return (0); 2867 obj->relocated = true; 2868 if (obj != rtldobj) 2869 dbg("relocating \"%s\"", obj->path); 2870 2871 if (obj->symtab == NULL || obj->strtab == NULL || 2872 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2873 _rtld_error("%s: Shared object has no run-time symbol table", 2874 obj->path); 2875 return (-1); 2876 } 2877 2878 /* There are relocations to the write-protected text segment. */ 2879 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 2880 return (-1); 2881 2882 /* Process the non-PLT non-IFUNC relocations. */ 2883 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2884 return (-1); 2885 2886 /* Re-protected the text segment. */ 2887 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 2888 return (-1); 2889 2890 /* Set the special PLT or GOT entries. */ 2891 init_pltgot(obj); 2892 2893 /* Process the PLT relocations. */ 2894 if (reloc_plt(obj) == -1) 2895 return (-1); 2896 /* Relocate the jump slots if we are doing immediate binding. */ 2897 if (obj->bind_now || bind_now) { 2898 if (reloc_jmpslots(obj, flags, lockstate) == -1 || 2899 resolve_object_ifunc(obj, true, flags, lockstate) == -1) 2900 return (-1); 2901 } 2902 2903 /* 2904 * Process the non-PLT IFUNC relocations. The relocations are 2905 * processed in two phases, because IFUNC resolvers may 2906 * reference other symbols, which must be readily processed 2907 * before resolvers are called. 2908 */ 2909 if (obj->non_plt_gnu_ifunc && 2910 reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate)) 2911 return (-1); 2912 2913 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 2914 return (-1); 2915 2916 /* 2917 * Set up the magic number and version in the Obj_Entry. These 2918 * were checked in the crt1.o from the original ElfKit, so we 2919 * set them for backward compatibility. 2920 */ 2921 obj->magic = RTLD_MAGIC; 2922 obj->version = RTLD_VERSION; 2923 2924 return (0); 2925 } 2926 2927 /* 2928 * Relocate newly-loaded shared objects. The argument is a pointer to 2929 * the Obj_Entry for the first such object. All objects from the first 2930 * to the end of the list of objects are relocated. Returns 0 on success, 2931 * or -1 on failure. 2932 */ 2933 static int 2934 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2935 int flags, RtldLockState *lockstate) 2936 { 2937 Obj_Entry *obj; 2938 int error; 2939 2940 for (error = 0, obj = first; obj != NULL; 2941 obj = TAILQ_NEXT(obj, next)) { 2942 if (obj->marker) 2943 continue; 2944 error = relocate_object(obj, bind_now, rtldobj, flags, 2945 lockstate); 2946 if (error == -1) 2947 break; 2948 } 2949 return (error); 2950 } 2951 2952 /* 2953 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2954 * referencing STT_GNU_IFUNC symbols is postponed till the other 2955 * relocations are done. The indirect functions specified as 2956 * ifunc are allowed to call other symbols, so we need to have 2957 * objects relocated before asking for resolution from indirects. 2958 * 2959 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2960 * instead of the usual lazy handling of PLT slots. It is 2961 * consistent with how GNU does it. 2962 */ 2963 static int 2964 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2965 RtldLockState *lockstate) 2966 { 2967 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2968 return (-1); 2969 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2970 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2971 return (-1); 2972 return (0); 2973 } 2974 2975 static int 2976 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2977 RtldLockState *lockstate) 2978 { 2979 Obj_Entry *obj; 2980 2981 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2982 if (obj->marker) 2983 continue; 2984 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2985 return (-1); 2986 } 2987 return (0); 2988 } 2989 2990 static int 2991 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2992 RtldLockState *lockstate) 2993 { 2994 Objlist_Entry *elm; 2995 2996 STAILQ_FOREACH(elm, list, link) { 2997 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2998 lockstate) == -1) 2999 return (-1); 3000 } 3001 return (0); 3002 } 3003 3004 /* 3005 * Cleanup procedure. It will be called (by the atexit mechanism) just 3006 * before the process exits. 3007 */ 3008 static void 3009 rtld_exit(void) 3010 { 3011 RtldLockState lockstate; 3012 3013 wlock_acquire(rtld_bind_lock, &lockstate); 3014 dbg("rtld_exit()"); 3015 objlist_call_fini(&list_fini, NULL, &lockstate); 3016 /* No need to remove the items from the list, since we are exiting. */ 3017 if (!libmap_disable) 3018 lm_fini(); 3019 lock_release(rtld_bind_lock, &lockstate); 3020 } 3021 3022 /* 3023 * Iterate over a search path, translate each element, and invoke the 3024 * callback on the result. 3025 */ 3026 static void * 3027 path_enumerate(const char *path, path_enum_proc callback, 3028 const char *refobj_path, void *arg) 3029 { 3030 const char *trans; 3031 if (path == NULL) 3032 return (NULL); 3033 3034 path += strspn(path, ":;"); 3035 while (*path != '\0') { 3036 size_t len; 3037 char *res; 3038 3039 len = strcspn(path, ":;"); 3040 trans = lm_findn(refobj_path, path, len); 3041 if (trans) 3042 res = callback(trans, strlen(trans), arg); 3043 else 3044 res = callback(path, len, arg); 3045 3046 if (res != NULL) 3047 return (res); 3048 3049 path += len; 3050 path += strspn(path, ":;"); 3051 } 3052 3053 return (NULL); 3054 } 3055 3056 struct try_library_args { 3057 const char *name; 3058 size_t namelen; 3059 char *buffer; 3060 size_t buflen; 3061 int fd; 3062 }; 3063 3064 static void * 3065 try_library_path(const char *dir, size_t dirlen, void *param) 3066 { 3067 struct try_library_args *arg; 3068 int fd; 3069 3070 arg = param; 3071 if (*dir == '/' || trust) { 3072 char *pathname; 3073 3074 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3075 return (NULL); 3076 3077 pathname = arg->buffer; 3078 strncpy(pathname, dir, dirlen); 3079 pathname[dirlen] = '/'; 3080 strcpy(pathname + dirlen + 1, arg->name); 3081 3082 dbg(" Trying \"%s\"", pathname); 3083 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3084 if (fd >= 0) { 3085 dbg(" Opened \"%s\", fd %d", pathname, fd); 3086 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3087 strcpy(pathname, arg->buffer); 3088 arg->fd = fd; 3089 return (pathname); 3090 } else { 3091 dbg(" Failed to open \"%s\": %s", 3092 pathname, rtld_strerror(errno)); 3093 } 3094 } 3095 return (NULL); 3096 } 3097 3098 static char * 3099 search_library_path(const char *name, const char *path, 3100 const char *refobj_path, int *fdp) 3101 { 3102 char *p; 3103 struct try_library_args arg; 3104 3105 if (path == NULL) 3106 return NULL; 3107 3108 arg.name = name; 3109 arg.namelen = strlen(name); 3110 arg.buffer = xmalloc(PATH_MAX); 3111 arg.buflen = PATH_MAX; 3112 arg.fd = -1; 3113 3114 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3115 *fdp = arg.fd; 3116 3117 free(arg.buffer); 3118 3119 return (p); 3120 } 3121 3122 3123 /* 3124 * Finds the library with the given name using the directory descriptors 3125 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3126 * 3127 * Returns a freshly-opened close-on-exec file descriptor for the library, 3128 * or -1 if the library cannot be found. 3129 */ 3130 static char * 3131 search_library_pathfds(const char *name, const char *path, int *fdp) 3132 { 3133 char *envcopy, *fdstr, *found, *last_token; 3134 size_t len; 3135 int dirfd, fd; 3136 3137 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3138 3139 /* Don't load from user-specified libdirs into setuid binaries. */ 3140 if (!trust) 3141 return (NULL); 3142 3143 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3144 if (path == NULL) 3145 return (NULL); 3146 3147 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3148 if (name[0] == '/') { 3149 dbg("Absolute path (%s) passed to %s", name, __func__); 3150 return (NULL); 3151 } 3152 3153 /* 3154 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3155 * copy of the path, as strtok_r rewrites separator tokens 3156 * with '\0'. 3157 */ 3158 found = NULL; 3159 envcopy = xstrdup(path); 3160 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3161 fdstr = strtok_r(NULL, ":", &last_token)) { 3162 dirfd = parse_integer(fdstr); 3163 if (dirfd < 0) { 3164 _rtld_error("failed to parse directory FD: '%s'", 3165 fdstr); 3166 break; 3167 } 3168 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3169 if (fd >= 0) { 3170 *fdp = fd; 3171 len = strlen(fdstr) + strlen(name) + 3; 3172 found = xmalloc(len); 3173 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3174 _rtld_error("error generating '%d/%s'", 3175 dirfd, name); 3176 rtld_die(); 3177 } 3178 dbg("open('%s') => %d", found, fd); 3179 break; 3180 } 3181 } 3182 free(envcopy); 3183 3184 return (found); 3185 } 3186 3187 3188 int 3189 dlclose(void *handle) 3190 { 3191 RtldLockState lockstate; 3192 int error; 3193 3194 wlock_acquire(rtld_bind_lock, &lockstate); 3195 error = dlclose_locked(handle, &lockstate); 3196 lock_release(rtld_bind_lock, &lockstate); 3197 return (error); 3198 } 3199 3200 static int 3201 dlclose_locked(void *handle, RtldLockState *lockstate) 3202 { 3203 Obj_Entry *root; 3204 3205 root = dlcheck(handle); 3206 if (root == NULL) 3207 return -1; 3208 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3209 root->path); 3210 3211 /* Unreference the object and its dependencies. */ 3212 root->dl_refcount--; 3213 3214 if (root->refcount == 1) { 3215 /* 3216 * The object will be no longer referenced, so we must unload it. 3217 * First, call the fini functions. 3218 */ 3219 objlist_call_fini(&list_fini, root, lockstate); 3220 3221 unref_dag(root); 3222 3223 /* Finish cleaning up the newly-unreferenced objects. */ 3224 GDB_STATE(RT_DELETE,&root->linkmap); 3225 unload_object(root, lockstate); 3226 GDB_STATE(RT_CONSISTENT,NULL); 3227 } else 3228 unref_dag(root); 3229 3230 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3231 return 0; 3232 } 3233 3234 char * 3235 dlerror(void) 3236 { 3237 char *msg = error_message; 3238 error_message = NULL; 3239 return msg; 3240 } 3241 3242 /* 3243 * This function is deprecated and has no effect. 3244 */ 3245 void 3246 dllockinit(void *context, 3247 void *(*_lock_create)(void *context) __unused, 3248 void (*_rlock_acquire)(void *lock) __unused, 3249 void (*_wlock_acquire)(void *lock) __unused, 3250 void (*_lock_release)(void *lock) __unused, 3251 void (*_lock_destroy)(void *lock) __unused, 3252 void (*context_destroy)(void *context)) 3253 { 3254 static void *cur_context; 3255 static void (*cur_context_destroy)(void *); 3256 3257 /* Just destroy the context from the previous call, if necessary. */ 3258 if (cur_context_destroy != NULL) 3259 cur_context_destroy(cur_context); 3260 cur_context = context; 3261 cur_context_destroy = context_destroy; 3262 } 3263 3264 void * 3265 dlopen(const char *name, int mode) 3266 { 3267 3268 return (rtld_dlopen(name, -1, mode)); 3269 } 3270 3271 void * 3272 fdlopen(int fd, int mode) 3273 { 3274 3275 return (rtld_dlopen(NULL, fd, mode)); 3276 } 3277 3278 static void * 3279 rtld_dlopen(const char *name, int fd, int mode) 3280 { 3281 RtldLockState lockstate; 3282 int lo_flags; 3283 3284 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3285 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3286 if (ld_tracing != NULL) { 3287 rlock_acquire(rtld_bind_lock, &lockstate); 3288 if (sigsetjmp(lockstate.env, 0) != 0) 3289 lock_upgrade(rtld_bind_lock, &lockstate); 3290 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3291 lock_release(rtld_bind_lock, &lockstate); 3292 } 3293 lo_flags = RTLD_LO_DLOPEN; 3294 if (mode & RTLD_NODELETE) 3295 lo_flags |= RTLD_LO_NODELETE; 3296 if (mode & RTLD_NOLOAD) 3297 lo_flags |= RTLD_LO_NOLOAD; 3298 if (ld_tracing != NULL) 3299 lo_flags |= RTLD_LO_TRACE; 3300 3301 return (dlopen_object(name, fd, obj_main, lo_flags, 3302 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3303 } 3304 3305 static void 3306 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3307 { 3308 3309 obj->dl_refcount--; 3310 unref_dag(obj); 3311 if (obj->refcount == 0) 3312 unload_object(obj, lockstate); 3313 } 3314 3315 static Obj_Entry * 3316 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3317 int mode, RtldLockState *lockstate) 3318 { 3319 Obj_Entry *old_obj_tail; 3320 Obj_Entry *obj; 3321 Objlist initlist; 3322 RtldLockState mlockstate; 3323 int result; 3324 3325 objlist_init(&initlist); 3326 3327 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3328 wlock_acquire(rtld_bind_lock, &mlockstate); 3329 lockstate = &mlockstate; 3330 } 3331 GDB_STATE(RT_ADD,NULL); 3332 3333 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3334 obj = NULL; 3335 if (name == NULL && fd == -1) { 3336 obj = obj_main; 3337 obj->refcount++; 3338 } else { 3339 obj = load_object(name, fd, refobj, lo_flags); 3340 } 3341 3342 if (obj) { 3343 obj->dl_refcount++; 3344 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3345 objlist_push_tail(&list_global, obj); 3346 if (globallist_next(old_obj_tail) != NULL) { 3347 /* We loaded something new. */ 3348 assert(globallist_next(old_obj_tail) == obj); 3349 result = load_needed_objects(obj, 3350 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 3351 init_dag(obj); 3352 ref_dag(obj); 3353 if (result != -1) 3354 result = rtld_verify_versions(&obj->dagmembers); 3355 if (result != -1 && ld_tracing) 3356 goto trace; 3357 if (result == -1 || relocate_object_dag(obj, 3358 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3359 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3360 lockstate) == -1) { 3361 dlopen_cleanup(obj, lockstate); 3362 obj = NULL; 3363 } else if (lo_flags & RTLD_LO_EARLY) { 3364 /* 3365 * Do not call the init functions for early loaded 3366 * filtees. The image is still not initialized enough 3367 * for them to work. 3368 * 3369 * Our object is found by the global object list and 3370 * will be ordered among all init calls done right 3371 * before transferring control to main. 3372 */ 3373 } else { 3374 /* Make list of init functions to call. */ 3375 initlist_add_objects(obj, obj, &initlist); 3376 } 3377 /* 3378 * Process all no_delete or global objects here, given 3379 * them own DAGs to prevent their dependencies from being 3380 * unloaded. This has to be done after we have loaded all 3381 * of the dependencies, so that we do not miss any. 3382 */ 3383 if (obj != NULL) 3384 process_z(obj); 3385 } else { 3386 /* 3387 * Bump the reference counts for objects on this DAG. If 3388 * this is the first dlopen() call for the object that was 3389 * already loaded as a dependency, initialize the dag 3390 * starting at it. 3391 */ 3392 init_dag(obj); 3393 ref_dag(obj); 3394 3395 if ((lo_flags & RTLD_LO_TRACE) != 0) 3396 goto trace; 3397 } 3398 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3399 obj->z_nodelete) && !obj->ref_nodel) { 3400 dbg("obj %s nodelete", obj->path); 3401 ref_dag(obj); 3402 obj->z_nodelete = obj->ref_nodel = true; 3403 } 3404 } 3405 3406 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3407 name); 3408 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3409 3410 if (!(lo_flags & RTLD_LO_EARLY)) { 3411 map_stacks_exec(lockstate); 3412 } 3413 3414 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3415 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3416 lockstate) == -1) { 3417 objlist_clear(&initlist); 3418 dlopen_cleanup(obj, lockstate); 3419 if (lockstate == &mlockstate) 3420 lock_release(rtld_bind_lock, lockstate); 3421 return (NULL); 3422 } 3423 3424 if (!(lo_flags & RTLD_LO_EARLY)) { 3425 /* Call the init functions. */ 3426 objlist_call_init(&initlist, lockstate); 3427 } 3428 objlist_clear(&initlist); 3429 if (lockstate == &mlockstate) 3430 lock_release(rtld_bind_lock, lockstate); 3431 return obj; 3432 trace: 3433 trace_loaded_objects(obj); 3434 if (lockstate == &mlockstate) 3435 lock_release(rtld_bind_lock, lockstate); 3436 exit(0); 3437 } 3438 3439 static void * 3440 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3441 int flags) 3442 { 3443 DoneList donelist; 3444 const Obj_Entry *obj, *defobj; 3445 const Elf_Sym *def; 3446 SymLook req; 3447 RtldLockState lockstate; 3448 tls_index ti; 3449 void *sym; 3450 int res; 3451 3452 def = NULL; 3453 defobj = NULL; 3454 symlook_init(&req, name); 3455 req.ventry = ve; 3456 req.flags = flags | SYMLOOK_IN_PLT; 3457 req.lockstate = &lockstate; 3458 3459 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3460 rlock_acquire(rtld_bind_lock, &lockstate); 3461 if (sigsetjmp(lockstate.env, 0) != 0) 3462 lock_upgrade(rtld_bind_lock, &lockstate); 3463 if (handle == NULL || handle == RTLD_NEXT || 3464 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3465 3466 if ((obj = obj_from_addr(retaddr)) == NULL) { 3467 _rtld_error("Cannot determine caller's shared object"); 3468 lock_release(rtld_bind_lock, &lockstate); 3469 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3470 return NULL; 3471 } 3472 if (handle == NULL) { /* Just the caller's shared object. */ 3473 res = symlook_obj(&req, obj); 3474 if (res == 0) { 3475 def = req.sym_out; 3476 defobj = req.defobj_out; 3477 } 3478 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3479 handle == RTLD_SELF) { /* ... caller included */ 3480 if (handle == RTLD_NEXT) 3481 obj = globallist_next(obj); 3482 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3483 if (obj->marker) 3484 continue; 3485 res = symlook_obj(&req, obj); 3486 if (res == 0) { 3487 if (def == NULL || 3488 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3489 def = req.sym_out; 3490 defobj = req.defobj_out; 3491 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3492 break; 3493 } 3494 } 3495 } 3496 /* 3497 * Search the dynamic linker itself, and possibly resolve the 3498 * symbol from there. This is how the application links to 3499 * dynamic linker services such as dlopen. 3500 */ 3501 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3502 res = symlook_obj(&req, &obj_rtld); 3503 if (res == 0) { 3504 def = req.sym_out; 3505 defobj = req.defobj_out; 3506 } 3507 } 3508 } else { 3509 assert(handle == RTLD_DEFAULT); 3510 res = symlook_default(&req, obj); 3511 if (res == 0) { 3512 defobj = req.defobj_out; 3513 def = req.sym_out; 3514 } 3515 } 3516 } else { 3517 if ((obj = dlcheck(handle)) == NULL) { 3518 lock_release(rtld_bind_lock, &lockstate); 3519 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3520 return NULL; 3521 } 3522 3523 donelist_init(&donelist); 3524 if (obj->mainprog) { 3525 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3526 res = symlook_global(&req, &donelist); 3527 if (res == 0) { 3528 def = req.sym_out; 3529 defobj = req.defobj_out; 3530 } 3531 /* 3532 * Search the dynamic linker itself, and possibly resolve the 3533 * symbol from there. This is how the application links to 3534 * dynamic linker services such as dlopen. 3535 */ 3536 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3537 res = symlook_obj(&req, &obj_rtld); 3538 if (res == 0) { 3539 def = req.sym_out; 3540 defobj = req.defobj_out; 3541 } 3542 } 3543 } 3544 else { 3545 /* Search the whole DAG rooted at the given object. */ 3546 res = symlook_list(&req, &obj->dagmembers, &donelist); 3547 if (res == 0) { 3548 def = req.sym_out; 3549 defobj = req.defobj_out; 3550 } 3551 } 3552 } 3553 3554 if (def != NULL) { 3555 lock_release(rtld_bind_lock, &lockstate); 3556 3557 /* 3558 * The value required by the caller is derived from the value 3559 * of the symbol. this is simply the relocated value of the 3560 * symbol. 3561 */ 3562 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3563 sym = make_function_pointer(def, defobj); 3564 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3565 sym = rtld_resolve_ifunc(defobj, def); 3566 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3567 ti.ti_module = defobj->tlsindex; 3568 ti.ti_offset = def->st_value; 3569 sym = __tls_get_addr(&ti); 3570 } else 3571 sym = defobj->relocbase + def->st_value; 3572 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3573 return (sym); 3574 } 3575 3576 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3577 ve != NULL ? ve->name : ""); 3578 lock_release(rtld_bind_lock, &lockstate); 3579 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3580 return NULL; 3581 } 3582 3583 void * 3584 dlsym(void *handle, const char *name) 3585 { 3586 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3587 SYMLOOK_DLSYM); 3588 } 3589 3590 dlfunc_t 3591 dlfunc(void *handle, const char *name) 3592 { 3593 union { 3594 void *d; 3595 dlfunc_t f; 3596 } rv; 3597 3598 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3599 SYMLOOK_DLSYM); 3600 return (rv.f); 3601 } 3602 3603 void * 3604 dlvsym(void *handle, const char *name, const char *version) 3605 { 3606 Ver_Entry ventry; 3607 3608 ventry.name = version; 3609 ventry.file = NULL; 3610 ventry.hash = elf_hash(version); 3611 ventry.flags= 0; 3612 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3613 SYMLOOK_DLSYM); 3614 } 3615 3616 int 3617 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3618 { 3619 const Obj_Entry *obj; 3620 RtldLockState lockstate; 3621 3622 rlock_acquire(rtld_bind_lock, &lockstate); 3623 obj = obj_from_addr(addr); 3624 if (obj == NULL) { 3625 _rtld_error("No shared object contains address"); 3626 lock_release(rtld_bind_lock, &lockstate); 3627 return (0); 3628 } 3629 rtld_fill_dl_phdr_info(obj, phdr_info); 3630 lock_release(rtld_bind_lock, &lockstate); 3631 return (1); 3632 } 3633 3634 int 3635 dladdr(const void *addr, Dl_info *info) 3636 { 3637 const Obj_Entry *obj; 3638 const Elf_Sym *def; 3639 void *symbol_addr; 3640 unsigned long symoffset; 3641 RtldLockState lockstate; 3642 3643 rlock_acquire(rtld_bind_lock, &lockstate); 3644 obj = obj_from_addr(addr); 3645 if (obj == NULL) { 3646 _rtld_error("No shared object contains address"); 3647 lock_release(rtld_bind_lock, &lockstate); 3648 return 0; 3649 } 3650 info->dli_fname = obj->path; 3651 info->dli_fbase = obj->mapbase; 3652 info->dli_saddr = (void *)0; 3653 info->dli_sname = NULL; 3654 3655 /* 3656 * Walk the symbol list looking for the symbol whose address is 3657 * closest to the address sent in. 3658 */ 3659 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3660 def = obj->symtab + symoffset; 3661 3662 /* 3663 * For skip the symbol if st_shndx is either SHN_UNDEF or 3664 * SHN_COMMON. 3665 */ 3666 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3667 continue; 3668 3669 /* 3670 * If the symbol is greater than the specified address, or if it 3671 * is further away from addr than the current nearest symbol, 3672 * then reject it. 3673 */ 3674 symbol_addr = obj->relocbase + def->st_value; 3675 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3676 continue; 3677 3678 /* Update our idea of the nearest symbol. */ 3679 info->dli_sname = obj->strtab + def->st_name; 3680 info->dli_saddr = symbol_addr; 3681 3682 /* Exact match? */ 3683 if (info->dli_saddr == addr) 3684 break; 3685 } 3686 lock_release(rtld_bind_lock, &lockstate); 3687 return 1; 3688 } 3689 3690 int 3691 dlinfo(void *handle, int request, void *p) 3692 { 3693 const Obj_Entry *obj; 3694 RtldLockState lockstate; 3695 int error; 3696 3697 rlock_acquire(rtld_bind_lock, &lockstate); 3698 3699 if (handle == NULL || handle == RTLD_SELF) { 3700 void *retaddr; 3701 3702 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3703 if ((obj = obj_from_addr(retaddr)) == NULL) 3704 _rtld_error("Cannot determine caller's shared object"); 3705 } else 3706 obj = dlcheck(handle); 3707 3708 if (obj == NULL) { 3709 lock_release(rtld_bind_lock, &lockstate); 3710 return (-1); 3711 } 3712 3713 error = 0; 3714 switch (request) { 3715 case RTLD_DI_LINKMAP: 3716 *((struct link_map const **)p) = &obj->linkmap; 3717 break; 3718 case RTLD_DI_ORIGIN: 3719 error = rtld_dirname(obj->path, p); 3720 break; 3721 3722 case RTLD_DI_SERINFOSIZE: 3723 case RTLD_DI_SERINFO: 3724 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3725 break; 3726 3727 default: 3728 _rtld_error("Invalid request %d passed to dlinfo()", request); 3729 error = -1; 3730 } 3731 3732 lock_release(rtld_bind_lock, &lockstate); 3733 3734 return (error); 3735 } 3736 3737 static void 3738 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3739 { 3740 3741 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3742 phdr_info->dlpi_name = obj->path; 3743 phdr_info->dlpi_phdr = obj->phdr; 3744 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3745 phdr_info->dlpi_tls_modid = obj->tlsindex; 3746 phdr_info->dlpi_tls_data = obj->tlsinit; 3747 phdr_info->dlpi_adds = obj_loads; 3748 phdr_info->dlpi_subs = obj_loads - obj_count; 3749 } 3750 3751 int 3752 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3753 { 3754 struct dl_phdr_info phdr_info; 3755 Obj_Entry *obj, marker; 3756 RtldLockState bind_lockstate, phdr_lockstate; 3757 int error; 3758 3759 init_marker(&marker); 3760 error = 0; 3761 3762 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3763 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3764 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3765 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3766 rtld_fill_dl_phdr_info(obj, &phdr_info); 3767 hold_object(obj); 3768 lock_release(rtld_bind_lock, &bind_lockstate); 3769 3770 error = callback(&phdr_info, sizeof phdr_info, param); 3771 3772 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3773 unhold_object(obj); 3774 obj = globallist_next(&marker); 3775 TAILQ_REMOVE(&obj_list, &marker, next); 3776 if (error != 0) { 3777 lock_release(rtld_bind_lock, &bind_lockstate); 3778 lock_release(rtld_phdr_lock, &phdr_lockstate); 3779 return (error); 3780 } 3781 } 3782 3783 if (error == 0) { 3784 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3785 lock_release(rtld_bind_lock, &bind_lockstate); 3786 error = callback(&phdr_info, sizeof(phdr_info), param); 3787 } 3788 lock_release(rtld_phdr_lock, &phdr_lockstate); 3789 return (error); 3790 } 3791 3792 static void * 3793 fill_search_info(const char *dir, size_t dirlen, void *param) 3794 { 3795 struct fill_search_info_args *arg; 3796 3797 arg = param; 3798 3799 if (arg->request == RTLD_DI_SERINFOSIZE) { 3800 arg->serinfo->dls_cnt ++; 3801 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3802 } else { 3803 struct dl_serpath *s_entry; 3804 3805 s_entry = arg->serpath; 3806 s_entry->dls_name = arg->strspace; 3807 s_entry->dls_flags = arg->flags; 3808 3809 strncpy(arg->strspace, dir, dirlen); 3810 arg->strspace[dirlen] = '\0'; 3811 3812 arg->strspace += dirlen + 1; 3813 arg->serpath++; 3814 } 3815 3816 return (NULL); 3817 } 3818 3819 static int 3820 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3821 { 3822 struct dl_serinfo _info; 3823 struct fill_search_info_args args; 3824 3825 args.request = RTLD_DI_SERINFOSIZE; 3826 args.serinfo = &_info; 3827 3828 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3829 _info.dls_cnt = 0; 3830 3831 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 3832 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 3833 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 3834 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 3835 if (!obj->z_nodeflib) 3836 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 3837 3838 3839 if (request == RTLD_DI_SERINFOSIZE) { 3840 info->dls_size = _info.dls_size; 3841 info->dls_cnt = _info.dls_cnt; 3842 return (0); 3843 } 3844 3845 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3846 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3847 return (-1); 3848 } 3849 3850 args.request = RTLD_DI_SERINFO; 3851 args.serinfo = info; 3852 args.serpath = &info->dls_serpath[0]; 3853 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3854 3855 args.flags = LA_SER_RUNPATH; 3856 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 3857 return (-1); 3858 3859 args.flags = LA_SER_LIBPATH; 3860 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 3861 return (-1); 3862 3863 args.flags = LA_SER_RUNPATH; 3864 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 3865 return (-1); 3866 3867 args.flags = LA_SER_CONFIG; 3868 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 3869 != NULL) 3870 return (-1); 3871 3872 args.flags = LA_SER_DEFAULT; 3873 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 3874 fill_search_info, NULL, &args) != NULL) 3875 return (-1); 3876 return (0); 3877 } 3878 3879 static int 3880 rtld_dirname(const char *path, char *bname) 3881 { 3882 const char *endp; 3883 3884 /* Empty or NULL string gets treated as "." */ 3885 if (path == NULL || *path == '\0') { 3886 bname[0] = '.'; 3887 bname[1] = '\0'; 3888 return (0); 3889 } 3890 3891 /* Strip trailing slashes */ 3892 endp = path + strlen(path) - 1; 3893 while (endp > path && *endp == '/') 3894 endp--; 3895 3896 /* Find the start of the dir */ 3897 while (endp > path && *endp != '/') 3898 endp--; 3899 3900 /* Either the dir is "/" or there are no slashes */ 3901 if (endp == path) { 3902 bname[0] = *endp == '/' ? '/' : '.'; 3903 bname[1] = '\0'; 3904 return (0); 3905 } else { 3906 do { 3907 endp--; 3908 } while (endp > path && *endp == '/'); 3909 } 3910 3911 if (endp - path + 2 > PATH_MAX) 3912 { 3913 _rtld_error("Filename is too long: %s", path); 3914 return(-1); 3915 } 3916 3917 strncpy(bname, path, endp - path + 1); 3918 bname[endp - path + 1] = '\0'; 3919 return (0); 3920 } 3921 3922 static int 3923 rtld_dirname_abs(const char *path, char *base) 3924 { 3925 char *last; 3926 3927 if (realpath(path, base) == NULL) 3928 return (-1); 3929 dbg("%s -> %s", path, base); 3930 last = strrchr(base, '/'); 3931 if (last == NULL) 3932 return (-1); 3933 if (last != base) 3934 *last = '\0'; 3935 return (0); 3936 } 3937 3938 static void 3939 linkmap_add(Obj_Entry *obj) 3940 { 3941 struct link_map *l = &obj->linkmap; 3942 struct link_map *prev; 3943 3944 obj->linkmap.l_name = obj->path; 3945 obj->linkmap.l_addr = obj->mapbase; 3946 obj->linkmap.l_ld = obj->dynamic; 3947 #ifdef __mips__ 3948 /* GDB needs load offset on MIPS to use the symbols */ 3949 obj->linkmap.l_offs = obj->relocbase; 3950 #endif 3951 3952 if (r_debug.r_map == NULL) { 3953 r_debug.r_map = l; 3954 return; 3955 } 3956 3957 /* 3958 * Scan to the end of the list, but not past the entry for the 3959 * dynamic linker, which we want to keep at the very end. 3960 */ 3961 for (prev = r_debug.r_map; 3962 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3963 prev = prev->l_next) 3964 ; 3965 3966 /* Link in the new entry. */ 3967 l->l_prev = prev; 3968 l->l_next = prev->l_next; 3969 if (l->l_next != NULL) 3970 l->l_next->l_prev = l; 3971 prev->l_next = l; 3972 } 3973 3974 static void 3975 linkmap_delete(Obj_Entry *obj) 3976 { 3977 struct link_map *l = &obj->linkmap; 3978 3979 if (l->l_prev == NULL) { 3980 if ((r_debug.r_map = l->l_next) != NULL) 3981 l->l_next->l_prev = NULL; 3982 return; 3983 } 3984 3985 if ((l->l_prev->l_next = l->l_next) != NULL) 3986 l->l_next->l_prev = l->l_prev; 3987 } 3988 3989 /* 3990 * Function for the debugger to set a breakpoint on to gain control. 3991 * 3992 * The two parameters allow the debugger to easily find and determine 3993 * what the runtime loader is doing and to whom it is doing it. 3994 * 3995 * When the loadhook trap is hit (r_debug_state, set at program 3996 * initialization), the arguments can be found on the stack: 3997 * 3998 * +8 struct link_map *m 3999 * +4 struct r_debug *rd 4000 * +0 RetAddr 4001 */ 4002 void 4003 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4004 { 4005 /* 4006 * The following is a hack to force the compiler to emit calls to 4007 * this function, even when optimizing. If the function is empty, 4008 * the compiler is not obliged to emit any code for calls to it, 4009 * even when marked __noinline. However, gdb depends on those 4010 * calls being made. 4011 */ 4012 __compiler_membar(); 4013 } 4014 4015 /* 4016 * A function called after init routines have completed. This can be used to 4017 * break before a program's entry routine is called, and can be used when 4018 * main is not available in the symbol table. 4019 */ 4020 void 4021 _r_debug_postinit(struct link_map *m __unused) 4022 { 4023 4024 /* See r_debug_state(). */ 4025 __compiler_membar(); 4026 } 4027 4028 static void 4029 release_object(Obj_Entry *obj) 4030 { 4031 4032 if (obj->holdcount > 0) { 4033 obj->unholdfree = true; 4034 return; 4035 } 4036 munmap(obj->mapbase, obj->mapsize); 4037 linkmap_delete(obj); 4038 obj_free(obj); 4039 } 4040 4041 /* 4042 * Get address of the pointer variable in the main program. 4043 * Prefer non-weak symbol over the weak one. 4044 */ 4045 static const void ** 4046 get_program_var_addr(const char *name, RtldLockState *lockstate) 4047 { 4048 SymLook req; 4049 DoneList donelist; 4050 4051 symlook_init(&req, name); 4052 req.lockstate = lockstate; 4053 donelist_init(&donelist); 4054 if (symlook_global(&req, &donelist) != 0) 4055 return (NULL); 4056 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4057 return ((const void **)make_function_pointer(req.sym_out, 4058 req.defobj_out)); 4059 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4060 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4061 else 4062 return ((const void **)(req.defobj_out->relocbase + 4063 req.sym_out->st_value)); 4064 } 4065 4066 /* 4067 * Set a pointer variable in the main program to the given value. This 4068 * is used to set key variables such as "environ" before any of the 4069 * init functions are called. 4070 */ 4071 static void 4072 set_program_var(const char *name, const void *value) 4073 { 4074 const void **addr; 4075 4076 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4077 dbg("\"%s\": *%p <-- %p", name, addr, value); 4078 *addr = value; 4079 } 4080 } 4081 4082 /* 4083 * Search the global objects, including dependencies and main object, 4084 * for the given symbol. 4085 */ 4086 static int 4087 symlook_global(SymLook *req, DoneList *donelist) 4088 { 4089 SymLook req1; 4090 const Objlist_Entry *elm; 4091 int res; 4092 4093 symlook_init_from_req(&req1, req); 4094 4095 /* Search all objects loaded at program start up. */ 4096 if (req->defobj_out == NULL || 4097 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4098 res = symlook_list(&req1, &list_main, donelist); 4099 if (res == 0 && (req->defobj_out == NULL || 4100 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4101 req->sym_out = req1.sym_out; 4102 req->defobj_out = req1.defobj_out; 4103 assert(req->defobj_out != NULL); 4104 } 4105 } 4106 4107 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4108 STAILQ_FOREACH(elm, &list_global, link) { 4109 if (req->defobj_out != NULL && 4110 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4111 break; 4112 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4113 if (res == 0 && (req->defobj_out == NULL || 4114 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4115 req->sym_out = req1.sym_out; 4116 req->defobj_out = req1.defobj_out; 4117 assert(req->defobj_out != NULL); 4118 } 4119 } 4120 4121 return (req->sym_out != NULL ? 0 : ESRCH); 4122 } 4123 4124 /* 4125 * Given a symbol name in a referencing object, find the corresponding 4126 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4127 * no definition was found. Returns a pointer to the Obj_Entry of the 4128 * defining object via the reference parameter DEFOBJ_OUT. 4129 */ 4130 static int 4131 symlook_default(SymLook *req, const Obj_Entry *refobj) 4132 { 4133 DoneList donelist; 4134 const Objlist_Entry *elm; 4135 SymLook req1; 4136 int res; 4137 4138 donelist_init(&donelist); 4139 symlook_init_from_req(&req1, req); 4140 4141 /* 4142 * Look first in the referencing object if linked symbolically, 4143 * and similarly handle protected symbols. 4144 */ 4145 res = symlook_obj(&req1, refobj); 4146 if (res == 0 && (refobj->symbolic || 4147 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4148 req->sym_out = req1.sym_out; 4149 req->defobj_out = req1.defobj_out; 4150 assert(req->defobj_out != NULL); 4151 } 4152 if (refobj->symbolic || req->defobj_out != NULL) 4153 donelist_check(&donelist, refobj); 4154 4155 symlook_global(req, &donelist); 4156 4157 /* Search all dlopened DAGs containing the referencing object. */ 4158 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4159 if (req->sym_out != NULL && 4160 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4161 break; 4162 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4163 if (res == 0 && (req->sym_out == NULL || 4164 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4165 req->sym_out = req1.sym_out; 4166 req->defobj_out = req1.defobj_out; 4167 assert(req->defobj_out != NULL); 4168 } 4169 } 4170 4171 /* 4172 * Search the dynamic linker itself, and possibly resolve the 4173 * symbol from there. This is how the application links to 4174 * dynamic linker services such as dlopen. 4175 */ 4176 if (req->sym_out == NULL || 4177 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4178 res = symlook_obj(&req1, &obj_rtld); 4179 if (res == 0) { 4180 req->sym_out = req1.sym_out; 4181 req->defobj_out = req1.defobj_out; 4182 assert(req->defobj_out != NULL); 4183 } 4184 } 4185 4186 return (req->sym_out != NULL ? 0 : ESRCH); 4187 } 4188 4189 static int 4190 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4191 { 4192 const Elf_Sym *def; 4193 const Obj_Entry *defobj; 4194 const Objlist_Entry *elm; 4195 SymLook req1; 4196 int res; 4197 4198 def = NULL; 4199 defobj = NULL; 4200 STAILQ_FOREACH(elm, objlist, link) { 4201 if (donelist_check(dlp, elm->obj)) 4202 continue; 4203 symlook_init_from_req(&req1, req); 4204 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4205 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4206 def = req1.sym_out; 4207 defobj = req1.defobj_out; 4208 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4209 break; 4210 } 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 chain of DAGS cointed to by the given Needed_Entry 4223 * for a symbol of the given name. Each DAG is scanned completely 4224 * before advancing to the next one. Returns a pointer to the symbol, 4225 * or NULL if no definition was found. 4226 */ 4227 static int 4228 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4229 { 4230 const Elf_Sym *def; 4231 const Needed_Entry *n; 4232 const Obj_Entry *defobj; 4233 SymLook req1; 4234 int res; 4235 4236 def = NULL; 4237 defobj = NULL; 4238 symlook_init_from_req(&req1, req); 4239 for (n = needed; n != NULL; n = n->next) { 4240 if (n->obj == NULL || 4241 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4242 continue; 4243 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4244 def = req1.sym_out; 4245 defobj = req1.defobj_out; 4246 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4247 break; 4248 } 4249 } 4250 if (def != NULL) { 4251 req->sym_out = def; 4252 req->defobj_out = defobj; 4253 return (0); 4254 } 4255 return (ESRCH); 4256 } 4257 4258 /* 4259 * Search the symbol table of a single shared object for a symbol of 4260 * the given name and version, if requested. Returns a pointer to the 4261 * symbol, or NULL if no definition was found. If the object is 4262 * filter, return filtered symbol from filtee. 4263 * 4264 * The symbol's hash value is passed in for efficiency reasons; that 4265 * eliminates many recomputations of the hash value. 4266 */ 4267 int 4268 symlook_obj(SymLook *req, const Obj_Entry *obj) 4269 { 4270 DoneList donelist; 4271 SymLook req1; 4272 int flags, res, mres; 4273 4274 /* 4275 * If there is at least one valid hash at this point, we prefer to 4276 * use the faster GNU version if available. 4277 */ 4278 if (obj->valid_hash_gnu) 4279 mres = symlook_obj1_gnu(req, obj); 4280 else if (obj->valid_hash_sysv) 4281 mres = symlook_obj1_sysv(req, obj); 4282 else 4283 return (EINVAL); 4284 4285 if (mres == 0) { 4286 if (obj->needed_filtees != NULL) { 4287 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4288 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4289 donelist_init(&donelist); 4290 symlook_init_from_req(&req1, req); 4291 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4292 if (res == 0) { 4293 req->sym_out = req1.sym_out; 4294 req->defobj_out = req1.defobj_out; 4295 } 4296 return (res); 4297 } 4298 if (obj->needed_aux_filtees != NULL) { 4299 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4300 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4301 donelist_init(&donelist); 4302 symlook_init_from_req(&req1, req); 4303 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4304 if (res == 0) { 4305 req->sym_out = req1.sym_out; 4306 req->defobj_out = req1.defobj_out; 4307 return (res); 4308 } 4309 } 4310 } 4311 return (mres); 4312 } 4313 4314 /* Symbol match routine common to both hash functions */ 4315 static bool 4316 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4317 const unsigned long symnum) 4318 { 4319 Elf_Versym verndx; 4320 const Elf_Sym *symp; 4321 const char *strp; 4322 4323 symp = obj->symtab + symnum; 4324 strp = obj->strtab + symp->st_name; 4325 4326 switch (ELF_ST_TYPE(symp->st_info)) { 4327 case STT_FUNC: 4328 case STT_NOTYPE: 4329 case STT_OBJECT: 4330 case STT_COMMON: 4331 case STT_GNU_IFUNC: 4332 if (symp->st_value == 0) 4333 return (false); 4334 /* fallthrough */ 4335 case STT_TLS: 4336 if (symp->st_shndx != SHN_UNDEF) 4337 break; 4338 #ifndef __mips__ 4339 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4340 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4341 break; 4342 #endif 4343 /* fallthrough */ 4344 default: 4345 return (false); 4346 } 4347 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4348 return (false); 4349 4350 if (req->ventry == NULL) { 4351 if (obj->versyms != NULL) { 4352 verndx = VER_NDX(obj->versyms[symnum]); 4353 if (verndx > obj->vernum) { 4354 _rtld_error( 4355 "%s: symbol %s references wrong version %d", 4356 obj->path, obj->strtab + symnum, verndx); 4357 return (false); 4358 } 4359 /* 4360 * If we are not called from dlsym (i.e. this 4361 * is a normal relocation from unversioned 4362 * binary), accept the symbol immediately if 4363 * it happens to have first version after this 4364 * shared object became versioned. Otherwise, 4365 * if symbol is versioned and not hidden, 4366 * remember it. If it is the only symbol with 4367 * this name exported by the shared object, it 4368 * will be returned as a match by the calling 4369 * function. If symbol is global (verndx < 2) 4370 * accept it unconditionally. 4371 */ 4372 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4373 verndx == VER_NDX_GIVEN) { 4374 result->sym_out = symp; 4375 return (true); 4376 } 4377 else if (verndx >= VER_NDX_GIVEN) { 4378 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4379 == 0) { 4380 if (result->vsymp == NULL) 4381 result->vsymp = symp; 4382 result->vcount++; 4383 } 4384 return (false); 4385 } 4386 } 4387 result->sym_out = symp; 4388 return (true); 4389 } 4390 if (obj->versyms == NULL) { 4391 if (object_match_name(obj, req->ventry->name)) { 4392 _rtld_error("%s: object %s should provide version %s " 4393 "for symbol %s", obj_rtld.path, obj->path, 4394 req->ventry->name, obj->strtab + symnum); 4395 return (false); 4396 } 4397 } else { 4398 verndx = VER_NDX(obj->versyms[symnum]); 4399 if (verndx > obj->vernum) { 4400 _rtld_error("%s: symbol %s references wrong version %d", 4401 obj->path, obj->strtab + symnum, verndx); 4402 return (false); 4403 } 4404 if (obj->vertab[verndx].hash != req->ventry->hash || 4405 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4406 /* 4407 * Version does not match. Look if this is a 4408 * global symbol and if it is not hidden. If 4409 * global symbol (verndx < 2) is available, 4410 * use it. Do not return symbol if we are 4411 * called by dlvsym, because dlvsym looks for 4412 * a specific version and default one is not 4413 * what dlvsym wants. 4414 */ 4415 if ((req->flags & SYMLOOK_DLSYM) || 4416 (verndx >= VER_NDX_GIVEN) || 4417 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4418 return (false); 4419 } 4420 } 4421 result->sym_out = symp; 4422 return (true); 4423 } 4424 4425 /* 4426 * Search for symbol using SysV hash function. 4427 * obj->buckets is known not to be NULL at this point; the test for this was 4428 * performed with the obj->valid_hash_sysv assignment. 4429 */ 4430 static int 4431 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4432 { 4433 unsigned long symnum; 4434 Sym_Match_Result matchres; 4435 4436 matchres.sym_out = NULL; 4437 matchres.vsymp = NULL; 4438 matchres.vcount = 0; 4439 4440 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4441 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4442 if (symnum >= obj->nchains) 4443 return (ESRCH); /* Bad object */ 4444 4445 if (matched_symbol(req, obj, &matchres, symnum)) { 4446 req->sym_out = matchres.sym_out; 4447 req->defobj_out = obj; 4448 return (0); 4449 } 4450 } 4451 if (matchres.vcount == 1) { 4452 req->sym_out = matchres.vsymp; 4453 req->defobj_out = obj; 4454 return (0); 4455 } 4456 return (ESRCH); 4457 } 4458 4459 /* Search for symbol using GNU hash function */ 4460 static int 4461 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4462 { 4463 Elf_Addr bloom_word; 4464 const Elf32_Word *hashval; 4465 Elf32_Word bucket; 4466 Sym_Match_Result matchres; 4467 unsigned int h1, h2; 4468 unsigned long symnum; 4469 4470 matchres.sym_out = NULL; 4471 matchres.vsymp = NULL; 4472 matchres.vcount = 0; 4473 4474 /* Pick right bitmask word from Bloom filter array */ 4475 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4476 obj->maskwords_bm_gnu]; 4477 4478 /* Calculate modulus word size of gnu hash and its derivative */ 4479 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4480 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4481 4482 /* Filter out the "definitely not in set" queries */ 4483 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4484 return (ESRCH); 4485 4486 /* Locate hash chain and corresponding value element*/ 4487 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4488 if (bucket == 0) 4489 return (ESRCH); 4490 hashval = &obj->chain_zero_gnu[bucket]; 4491 do { 4492 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4493 symnum = hashval - obj->chain_zero_gnu; 4494 if (matched_symbol(req, obj, &matchres, symnum)) { 4495 req->sym_out = matchres.sym_out; 4496 req->defobj_out = obj; 4497 return (0); 4498 } 4499 } 4500 } while ((*hashval++ & 1) == 0); 4501 if (matchres.vcount == 1) { 4502 req->sym_out = matchres.vsymp; 4503 req->defobj_out = obj; 4504 return (0); 4505 } 4506 return (ESRCH); 4507 } 4508 4509 static void 4510 trace_loaded_objects(Obj_Entry *obj) 4511 { 4512 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4513 int c; 4514 4515 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4516 main_local = ""; 4517 4518 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4519 fmt1 = "\t%o => %p (%x)\n"; 4520 4521 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4522 fmt2 = "\t%o (%x)\n"; 4523 4524 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4525 4526 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4527 Needed_Entry *needed; 4528 const char *name, *path; 4529 bool is_lib; 4530 4531 if (obj->marker) 4532 continue; 4533 if (list_containers && obj->needed != NULL) 4534 rtld_printf("%s:\n", obj->path); 4535 for (needed = obj->needed; needed; needed = needed->next) { 4536 if (needed->obj != NULL) { 4537 if (needed->obj->traced && !list_containers) 4538 continue; 4539 needed->obj->traced = true; 4540 path = needed->obj->path; 4541 } else 4542 path = "not found"; 4543 4544 name = obj->strtab + needed->name; 4545 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4546 4547 fmt = is_lib ? fmt1 : fmt2; 4548 while ((c = *fmt++) != '\0') { 4549 switch (c) { 4550 default: 4551 rtld_putchar(c); 4552 continue; 4553 case '\\': 4554 switch (c = *fmt) { 4555 case '\0': 4556 continue; 4557 case 'n': 4558 rtld_putchar('\n'); 4559 break; 4560 case 't': 4561 rtld_putchar('\t'); 4562 break; 4563 } 4564 break; 4565 case '%': 4566 switch (c = *fmt) { 4567 case '\0': 4568 continue; 4569 case '%': 4570 default: 4571 rtld_putchar(c); 4572 break; 4573 case 'A': 4574 rtld_putstr(main_local); 4575 break; 4576 case 'a': 4577 rtld_putstr(obj_main->path); 4578 break; 4579 case 'o': 4580 rtld_putstr(name); 4581 break; 4582 #if 0 4583 case 'm': 4584 rtld_printf("%d", sodp->sod_major); 4585 break; 4586 case 'n': 4587 rtld_printf("%d", sodp->sod_minor); 4588 break; 4589 #endif 4590 case 'p': 4591 rtld_putstr(path); 4592 break; 4593 case 'x': 4594 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4595 0); 4596 break; 4597 } 4598 break; 4599 } 4600 ++fmt; 4601 } 4602 } 4603 } 4604 } 4605 4606 /* 4607 * Unload a dlopened object and its dependencies from memory and from 4608 * our data structures. It is assumed that the DAG rooted in the 4609 * object has already been unreferenced, and that the object has a 4610 * reference count of 0. 4611 */ 4612 static void 4613 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4614 { 4615 Obj_Entry marker, *obj, *next; 4616 4617 assert(root->refcount == 0); 4618 4619 /* 4620 * Pass over the DAG removing unreferenced objects from 4621 * appropriate lists. 4622 */ 4623 unlink_object(root); 4624 4625 /* Unmap all objects that are no longer referenced. */ 4626 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4627 next = TAILQ_NEXT(obj, next); 4628 if (obj->marker || obj->refcount != 0) 4629 continue; 4630 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4631 obj->mapsize, 0, obj->path); 4632 dbg("unloading \"%s\"", obj->path); 4633 /* 4634 * Unlink the object now to prevent new references from 4635 * being acquired while the bind lock is dropped in 4636 * recursive dlclose() invocations. 4637 */ 4638 TAILQ_REMOVE(&obj_list, obj, next); 4639 obj_count--; 4640 4641 if (obj->filtees_loaded) { 4642 if (next != NULL) { 4643 init_marker(&marker); 4644 TAILQ_INSERT_BEFORE(next, &marker, next); 4645 unload_filtees(obj, lockstate); 4646 next = TAILQ_NEXT(&marker, next); 4647 TAILQ_REMOVE(&obj_list, &marker, next); 4648 } else 4649 unload_filtees(obj, lockstate); 4650 } 4651 release_object(obj); 4652 } 4653 } 4654 4655 static void 4656 unlink_object(Obj_Entry *root) 4657 { 4658 Objlist_Entry *elm; 4659 4660 if (root->refcount == 0) { 4661 /* Remove the object from the RTLD_GLOBAL list. */ 4662 objlist_remove(&list_global, root); 4663 4664 /* Remove the object from all objects' DAG lists. */ 4665 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4666 objlist_remove(&elm->obj->dldags, root); 4667 if (elm->obj != root) 4668 unlink_object(elm->obj); 4669 } 4670 } 4671 } 4672 4673 static void 4674 ref_dag(Obj_Entry *root) 4675 { 4676 Objlist_Entry *elm; 4677 4678 assert(root->dag_inited); 4679 STAILQ_FOREACH(elm, &root->dagmembers, link) 4680 elm->obj->refcount++; 4681 } 4682 4683 static void 4684 unref_dag(Obj_Entry *root) 4685 { 4686 Objlist_Entry *elm; 4687 4688 assert(root->dag_inited); 4689 STAILQ_FOREACH(elm, &root->dagmembers, link) 4690 elm->obj->refcount--; 4691 } 4692 4693 /* 4694 * Common code for MD __tls_get_addr(). 4695 */ 4696 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4697 static void * 4698 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4699 { 4700 Elf_Addr *newdtv, *dtv; 4701 RtldLockState lockstate; 4702 int to_copy; 4703 4704 dtv = *dtvp; 4705 /* Check dtv generation in case new modules have arrived */ 4706 if (dtv[0] != tls_dtv_generation) { 4707 wlock_acquire(rtld_bind_lock, &lockstate); 4708 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4709 to_copy = dtv[1]; 4710 if (to_copy > tls_max_index) 4711 to_copy = tls_max_index; 4712 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4713 newdtv[0] = tls_dtv_generation; 4714 newdtv[1] = tls_max_index; 4715 free(dtv); 4716 lock_release(rtld_bind_lock, &lockstate); 4717 dtv = *dtvp = newdtv; 4718 } 4719 4720 /* Dynamically allocate module TLS if necessary */ 4721 if (dtv[index + 1] == 0) { 4722 /* Signal safe, wlock will block out signals. */ 4723 wlock_acquire(rtld_bind_lock, &lockstate); 4724 if (!dtv[index + 1]) 4725 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4726 lock_release(rtld_bind_lock, &lockstate); 4727 } 4728 return ((void *)(dtv[index + 1] + offset)); 4729 } 4730 4731 void * 4732 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4733 { 4734 Elf_Addr *dtv; 4735 4736 dtv = *dtvp; 4737 /* Check dtv generation in case new modules have arrived */ 4738 if (__predict_true(dtv[0] == tls_dtv_generation && 4739 dtv[index + 1] != 0)) 4740 return ((void *)(dtv[index + 1] + offset)); 4741 return (tls_get_addr_slow(dtvp, index, offset)); 4742 } 4743 4744 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4745 defined(__powerpc__) || defined(__riscv) 4746 4747 /* 4748 * Return pointer to allocated TLS block 4749 */ 4750 static void * 4751 get_tls_block_ptr(void *tcb, size_t tcbsize) 4752 { 4753 size_t extra_size, post_size, pre_size, tls_block_size; 4754 size_t tls_init_align; 4755 4756 tls_init_align = MAX(obj_main->tlsalign, 1); 4757 4758 /* Compute fragments 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 4764 return ((char *)tcb - pre_size - extra_size); 4765 } 4766 4767 /* 4768 * Allocate Static TLS using the Variant I method. 4769 * 4770 * For details on the layout, see lib/libc/gen/tls.c. 4771 * 4772 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4773 * it is based on tls_last_offset, and TLS offsets here are really TCB 4774 * offsets, whereas libc's tls_static_space is just the executable's static 4775 * TLS segment. 4776 */ 4777 void * 4778 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4779 { 4780 Obj_Entry *obj; 4781 char *tls_block; 4782 Elf_Addr *dtv, **tcb; 4783 Elf_Addr addr; 4784 Elf_Addr i; 4785 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4786 size_t tls_init_align; 4787 4788 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4789 return (oldtcb); 4790 4791 assert(tcbsize >= TLS_TCB_SIZE); 4792 maxalign = MAX(tcbalign, tls_static_max_align); 4793 tls_init_align = MAX(obj_main->tlsalign, 1); 4794 4795 /* Compute fragmets sizes. */ 4796 extra_size = tcbsize - TLS_TCB_SIZE; 4797 post_size = calculate_tls_post_size(tls_init_align); 4798 tls_block_size = tcbsize + post_size; 4799 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4800 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 4801 4802 /* Allocate whole TLS block */ 4803 tls_block = malloc_aligned(tls_block_size, maxalign); 4804 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 4805 4806 if (oldtcb != NULL) { 4807 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 4808 tls_static_space); 4809 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 4810 4811 /* Adjust the DTV. */ 4812 dtv = tcb[0]; 4813 for (i = 0; i < dtv[1]; i++) { 4814 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4815 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4816 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 4817 } 4818 } 4819 } else { 4820 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4821 tcb[0] = dtv; 4822 dtv[0] = tls_dtv_generation; 4823 dtv[1] = tls_max_index; 4824 4825 for (obj = globallist_curr(objs); obj != NULL; 4826 obj = globallist_next(obj)) { 4827 if (obj->tlsoffset > 0) { 4828 addr = (Elf_Addr)tcb + obj->tlsoffset; 4829 if (obj->tlsinitsize > 0) 4830 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4831 if (obj->tlssize > obj->tlsinitsize) 4832 memset((void*)(addr + obj->tlsinitsize), 0, 4833 obj->tlssize - obj->tlsinitsize); 4834 dtv[obj->tlsindex + 1] = addr; 4835 } 4836 } 4837 } 4838 4839 return (tcb); 4840 } 4841 4842 void 4843 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 4844 { 4845 Elf_Addr *dtv; 4846 Elf_Addr tlsstart, tlsend; 4847 size_t post_size; 4848 size_t dtvsize, i, tls_init_align; 4849 4850 assert(tcbsize >= TLS_TCB_SIZE); 4851 tls_init_align = MAX(obj_main->tlsalign, 1); 4852 4853 /* Compute fragments sizes. */ 4854 post_size = calculate_tls_post_size(tls_init_align); 4855 4856 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 4857 tlsend = (Elf_Addr)tcb + tls_static_space; 4858 4859 dtv = *(Elf_Addr **)tcb; 4860 dtvsize = dtv[1]; 4861 for (i = 0; i < dtvsize; i++) { 4862 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4863 free((void*)dtv[i+2]); 4864 } 4865 } 4866 free(dtv); 4867 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 4868 } 4869 4870 #endif 4871 4872 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4873 4874 /* 4875 * Allocate Static TLS using the Variant II method. 4876 */ 4877 void * 4878 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4879 { 4880 Obj_Entry *obj; 4881 size_t size, ralign; 4882 char *tls; 4883 Elf_Addr *dtv, *olddtv; 4884 Elf_Addr segbase, oldsegbase, addr; 4885 size_t i; 4886 4887 ralign = tcbalign; 4888 if (tls_static_max_align > ralign) 4889 ralign = tls_static_max_align; 4890 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4891 4892 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4893 tls = malloc_aligned(size, ralign); 4894 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4895 4896 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4897 ((Elf_Addr*)segbase)[0] = segbase; 4898 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4899 4900 dtv[0] = tls_dtv_generation; 4901 dtv[1] = tls_max_index; 4902 4903 if (oldtls) { 4904 /* 4905 * Copy the static TLS block over whole. 4906 */ 4907 oldsegbase = (Elf_Addr) oldtls; 4908 memcpy((void *)(segbase - tls_static_space), 4909 (const void *)(oldsegbase - tls_static_space), 4910 tls_static_space); 4911 4912 /* 4913 * If any dynamic TLS blocks have been created tls_get_addr(), 4914 * move them over. 4915 */ 4916 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4917 for (i = 0; i < olddtv[1]; i++) { 4918 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4919 dtv[i+2] = olddtv[i+2]; 4920 olddtv[i+2] = 0; 4921 } 4922 } 4923 4924 /* 4925 * We assume that this block was the one we created with 4926 * allocate_initial_tls(). 4927 */ 4928 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4929 } else { 4930 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4931 if (obj->marker || obj->tlsoffset == 0) 4932 continue; 4933 addr = segbase - obj->tlsoffset; 4934 memset((void*)(addr + obj->tlsinitsize), 4935 0, obj->tlssize - obj->tlsinitsize); 4936 if (obj->tlsinit) 4937 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4938 dtv[obj->tlsindex + 1] = addr; 4939 } 4940 } 4941 4942 return (void*) segbase; 4943 } 4944 4945 void 4946 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 4947 { 4948 Elf_Addr* dtv; 4949 size_t size, ralign; 4950 int dtvsize, i; 4951 Elf_Addr tlsstart, tlsend; 4952 4953 /* 4954 * Figure out the size of the initial TLS block so that we can 4955 * find stuff which ___tls_get_addr() allocated dynamically. 4956 */ 4957 ralign = tcbalign; 4958 if (tls_static_max_align > ralign) 4959 ralign = tls_static_max_align; 4960 size = round(tls_static_space, ralign); 4961 4962 dtv = ((Elf_Addr**)tls)[1]; 4963 dtvsize = dtv[1]; 4964 tlsend = (Elf_Addr) tls; 4965 tlsstart = tlsend - size; 4966 for (i = 0; i < dtvsize; i++) { 4967 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4968 free_aligned((void *)dtv[i + 2]); 4969 } 4970 } 4971 4972 free_aligned((void *)tlsstart); 4973 free((void*) dtv); 4974 } 4975 4976 #endif 4977 4978 /* 4979 * Allocate TLS block for module with given index. 4980 */ 4981 void * 4982 allocate_module_tls(int index) 4983 { 4984 Obj_Entry* obj; 4985 char* p; 4986 4987 TAILQ_FOREACH(obj, &obj_list, next) { 4988 if (obj->marker) 4989 continue; 4990 if (obj->tlsindex == index) 4991 break; 4992 } 4993 if (!obj) { 4994 _rtld_error("Can't find module with TLS index %d", index); 4995 rtld_die(); 4996 } 4997 4998 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4999 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5000 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5001 5002 return p; 5003 } 5004 5005 bool 5006 allocate_tls_offset(Obj_Entry *obj) 5007 { 5008 size_t off; 5009 5010 if (obj->tls_done) 5011 return true; 5012 5013 if (obj->tlssize == 0) { 5014 obj->tls_done = true; 5015 return true; 5016 } 5017 5018 if (tls_last_offset == 0) 5019 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 5020 else 5021 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5022 obj->tlssize, obj->tlsalign); 5023 5024 /* 5025 * If we have already fixed the size of the static TLS block, we 5026 * must stay within that size. When allocating the static TLS, we 5027 * leave a small amount of space spare to be used for dynamically 5028 * loading modules which use static TLS. 5029 */ 5030 if (tls_static_space != 0) { 5031 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 5032 return false; 5033 } else if (obj->tlsalign > tls_static_max_align) { 5034 tls_static_max_align = obj->tlsalign; 5035 } 5036 5037 tls_last_offset = obj->tlsoffset = off; 5038 tls_last_size = obj->tlssize; 5039 obj->tls_done = true; 5040 5041 return true; 5042 } 5043 5044 void 5045 free_tls_offset(Obj_Entry *obj) 5046 { 5047 5048 /* 5049 * If we were the last thing to allocate out of the static TLS 5050 * block, we give our space back to the 'allocator'. This is a 5051 * simplistic workaround to allow libGL.so.1 to be loaded and 5052 * unloaded multiple times. 5053 */ 5054 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5055 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5056 tls_last_offset -= obj->tlssize; 5057 tls_last_size = 0; 5058 } 5059 } 5060 5061 void * 5062 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5063 { 5064 void *ret; 5065 RtldLockState lockstate; 5066 5067 wlock_acquire(rtld_bind_lock, &lockstate); 5068 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5069 tcbsize, tcbalign); 5070 lock_release(rtld_bind_lock, &lockstate); 5071 return (ret); 5072 } 5073 5074 void 5075 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5076 { 5077 RtldLockState lockstate; 5078 5079 wlock_acquire(rtld_bind_lock, &lockstate); 5080 free_tls(tcb, tcbsize, tcbalign); 5081 lock_release(rtld_bind_lock, &lockstate); 5082 } 5083 5084 static void 5085 object_add_name(Obj_Entry *obj, const char *name) 5086 { 5087 Name_Entry *entry; 5088 size_t len; 5089 5090 len = strlen(name); 5091 entry = malloc(sizeof(Name_Entry) + len); 5092 5093 if (entry != NULL) { 5094 strcpy(entry->name, name); 5095 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5096 } 5097 } 5098 5099 static int 5100 object_match_name(const Obj_Entry *obj, const char *name) 5101 { 5102 Name_Entry *entry; 5103 5104 STAILQ_FOREACH(entry, &obj->names, link) { 5105 if (strcmp(name, entry->name) == 0) 5106 return (1); 5107 } 5108 return (0); 5109 } 5110 5111 static Obj_Entry * 5112 locate_dependency(const Obj_Entry *obj, const char *name) 5113 { 5114 const Objlist_Entry *entry; 5115 const Needed_Entry *needed; 5116 5117 STAILQ_FOREACH(entry, &list_main, link) { 5118 if (object_match_name(entry->obj, name)) 5119 return entry->obj; 5120 } 5121 5122 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5123 if (strcmp(obj->strtab + needed->name, name) == 0 || 5124 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5125 /* 5126 * If there is DT_NEEDED for the name we are looking for, 5127 * we are all set. Note that object might not be found if 5128 * dependency was not loaded yet, so the function can 5129 * return NULL here. This is expected and handled 5130 * properly by the caller. 5131 */ 5132 return (needed->obj); 5133 } 5134 } 5135 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5136 obj->path, name); 5137 rtld_die(); 5138 } 5139 5140 static int 5141 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5142 const Elf_Vernaux *vna) 5143 { 5144 const Elf_Verdef *vd; 5145 const char *vername; 5146 5147 vername = refobj->strtab + vna->vna_name; 5148 vd = depobj->verdef; 5149 if (vd == NULL) { 5150 _rtld_error("%s: version %s required by %s not defined", 5151 depobj->path, vername, refobj->path); 5152 return (-1); 5153 } 5154 for (;;) { 5155 if (vd->vd_version != VER_DEF_CURRENT) { 5156 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5157 depobj->path, vd->vd_version); 5158 return (-1); 5159 } 5160 if (vna->vna_hash == vd->vd_hash) { 5161 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5162 ((const char *)vd + vd->vd_aux); 5163 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5164 return (0); 5165 } 5166 if (vd->vd_next == 0) 5167 break; 5168 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5169 } 5170 if (vna->vna_flags & VER_FLG_WEAK) 5171 return (0); 5172 _rtld_error("%s: version %s required by %s not found", 5173 depobj->path, vername, refobj->path); 5174 return (-1); 5175 } 5176 5177 static int 5178 rtld_verify_object_versions(Obj_Entry *obj) 5179 { 5180 const Elf_Verneed *vn; 5181 const Elf_Verdef *vd; 5182 const Elf_Verdaux *vda; 5183 const Elf_Vernaux *vna; 5184 const Obj_Entry *depobj; 5185 int maxvernum, vernum; 5186 5187 if (obj->ver_checked) 5188 return (0); 5189 obj->ver_checked = true; 5190 5191 maxvernum = 0; 5192 /* 5193 * Walk over defined and required version records and figure out 5194 * max index used by any of them. Do very basic sanity checking 5195 * while there. 5196 */ 5197 vn = obj->verneed; 5198 while (vn != NULL) { 5199 if (vn->vn_version != VER_NEED_CURRENT) { 5200 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5201 obj->path, vn->vn_version); 5202 return (-1); 5203 } 5204 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5205 for (;;) { 5206 vernum = VER_NEED_IDX(vna->vna_other); 5207 if (vernum > maxvernum) 5208 maxvernum = vernum; 5209 if (vna->vna_next == 0) 5210 break; 5211 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5212 } 5213 if (vn->vn_next == 0) 5214 break; 5215 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5216 } 5217 5218 vd = obj->verdef; 5219 while (vd != NULL) { 5220 if (vd->vd_version != VER_DEF_CURRENT) { 5221 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5222 obj->path, vd->vd_version); 5223 return (-1); 5224 } 5225 vernum = VER_DEF_IDX(vd->vd_ndx); 5226 if (vernum > maxvernum) 5227 maxvernum = vernum; 5228 if (vd->vd_next == 0) 5229 break; 5230 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5231 } 5232 5233 if (maxvernum == 0) 5234 return (0); 5235 5236 /* 5237 * Store version information in array indexable by version index. 5238 * Verify that object version requirements are satisfied along the 5239 * way. 5240 */ 5241 obj->vernum = maxvernum + 1; 5242 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5243 5244 vd = obj->verdef; 5245 while (vd != NULL) { 5246 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5247 vernum = VER_DEF_IDX(vd->vd_ndx); 5248 assert(vernum <= maxvernum); 5249 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5250 obj->vertab[vernum].hash = vd->vd_hash; 5251 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5252 obj->vertab[vernum].file = NULL; 5253 obj->vertab[vernum].flags = 0; 5254 } 5255 if (vd->vd_next == 0) 5256 break; 5257 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5258 } 5259 5260 vn = obj->verneed; 5261 while (vn != NULL) { 5262 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5263 if (depobj == NULL) 5264 return (-1); 5265 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5266 for (;;) { 5267 if (check_object_provided_version(obj, depobj, vna)) 5268 return (-1); 5269 vernum = VER_NEED_IDX(vna->vna_other); 5270 assert(vernum <= maxvernum); 5271 obj->vertab[vernum].hash = vna->vna_hash; 5272 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5273 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5274 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5275 VER_INFO_HIDDEN : 0; 5276 if (vna->vna_next == 0) 5277 break; 5278 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5279 } 5280 if (vn->vn_next == 0) 5281 break; 5282 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5283 } 5284 return 0; 5285 } 5286 5287 static int 5288 rtld_verify_versions(const Objlist *objlist) 5289 { 5290 Objlist_Entry *entry; 5291 int rc; 5292 5293 rc = 0; 5294 STAILQ_FOREACH(entry, objlist, link) { 5295 /* 5296 * Skip dummy objects or objects that have their version requirements 5297 * already checked. 5298 */ 5299 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5300 continue; 5301 if (rtld_verify_object_versions(entry->obj) == -1) { 5302 rc = -1; 5303 if (ld_tracing == NULL) 5304 break; 5305 } 5306 } 5307 if (rc == 0 || ld_tracing != NULL) 5308 rc = rtld_verify_object_versions(&obj_rtld); 5309 return rc; 5310 } 5311 5312 const Ver_Entry * 5313 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5314 { 5315 Elf_Versym vernum; 5316 5317 if (obj->vertab) { 5318 vernum = VER_NDX(obj->versyms[symnum]); 5319 if (vernum >= obj->vernum) { 5320 _rtld_error("%s: symbol %s has wrong verneed value %d", 5321 obj->path, obj->strtab + symnum, vernum); 5322 } else if (obj->vertab[vernum].hash != 0) { 5323 return &obj->vertab[vernum]; 5324 } 5325 } 5326 return NULL; 5327 } 5328 5329 int 5330 _rtld_get_stack_prot(void) 5331 { 5332 5333 return (stack_prot); 5334 } 5335 5336 int 5337 _rtld_is_dlopened(void *arg) 5338 { 5339 Obj_Entry *obj; 5340 RtldLockState lockstate; 5341 int res; 5342 5343 rlock_acquire(rtld_bind_lock, &lockstate); 5344 obj = dlcheck(arg); 5345 if (obj == NULL) 5346 obj = obj_from_addr(arg); 5347 if (obj == NULL) { 5348 _rtld_error("No shared object contains address"); 5349 lock_release(rtld_bind_lock, &lockstate); 5350 return (-1); 5351 } 5352 res = obj->dlopened ? 1 : 0; 5353 lock_release(rtld_bind_lock, &lockstate); 5354 return (res); 5355 } 5356 5357 int 5358 obj_enforce_relro(Obj_Entry *obj) 5359 { 5360 5361 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5362 PROT_READ) == -1) { 5363 _rtld_error("%s: Cannot enforce relro protection: %s", 5364 obj->path, rtld_strerror(errno)); 5365 return (-1); 5366 } 5367 return (0); 5368 } 5369 5370 static void 5371 map_stacks_exec(RtldLockState *lockstate) 5372 { 5373 void (*thr_map_stacks_exec)(void); 5374 5375 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5376 return; 5377 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5378 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5379 if (thr_map_stacks_exec != NULL) { 5380 stack_prot |= PROT_EXEC; 5381 thr_map_stacks_exec(); 5382 } 5383 } 5384 5385 void 5386 symlook_init(SymLook *dst, const char *name) 5387 { 5388 5389 bzero(dst, sizeof(*dst)); 5390 dst->name = name; 5391 dst->hash = elf_hash(name); 5392 dst->hash_gnu = gnu_hash(name); 5393 } 5394 5395 static void 5396 symlook_init_from_req(SymLook *dst, const SymLook *src) 5397 { 5398 5399 dst->name = src->name; 5400 dst->hash = src->hash; 5401 dst->hash_gnu = src->hash_gnu; 5402 dst->ventry = src->ventry; 5403 dst->flags = src->flags; 5404 dst->defobj_out = NULL; 5405 dst->sym_out = NULL; 5406 dst->lockstate = src->lockstate; 5407 } 5408 5409 static int 5410 open_binary_fd(const char *argv0, bool search_in_path) 5411 { 5412 char *pathenv, *pe, binpath[PATH_MAX]; 5413 int fd; 5414 5415 if (search_in_path && strchr(argv0, '/') == NULL) { 5416 pathenv = getenv("PATH"); 5417 if (pathenv == NULL) { 5418 _rtld_error("-p and no PATH environment variable"); 5419 rtld_die(); 5420 } 5421 pathenv = strdup(pathenv); 5422 if (pathenv == NULL) { 5423 _rtld_error("Cannot allocate memory"); 5424 rtld_die(); 5425 } 5426 fd = -1; 5427 errno = ENOENT; 5428 while ((pe = strsep(&pathenv, ":")) != NULL) { 5429 if (strlcpy(binpath, pe, sizeof(binpath)) >= 5430 sizeof(binpath)) 5431 continue; 5432 if (binpath[0] != '\0' && 5433 strlcat(binpath, "/", sizeof(binpath)) >= 5434 sizeof(binpath)) 5435 continue; 5436 if (strlcat(binpath, argv0, sizeof(binpath)) >= 5437 sizeof(binpath)) 5438 continue; 5439 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5440 if (fd != -1 || errno != ENOENT) 5441 break; 5442 } 5443 free(pathenv); 5444 } else { 5445 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5446 } 5447 5448 if (fd == -1) { 5449 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5450 rtld_die(); 5451 } 5452 return (fd); 5453 } 5454 5455 /* 5456 * Parse a set of command-line arguments. 5457 */ 5458 static int 5459 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp) 5460 { 5461 const char *arg; 5462 int fd, i, j, arglen; 5463 char opt; 5464 5465 dbg("Parsing command-line arguments"); 5466 *use_pathp = false; 5467 *fdp = -1; 5468 5469 for (i = 1; i < argc; i++ ) { 5470 arg = argv[i]; 5471 dbg("argv[%d]: '%s'", i, arg); 5472 5473 /* 5474 * rtld arguments end with an explicit "--" or with the first 5475 * non-prefixed argument. 5476 */ 5477 if (strcmp(arg, "--") == 0) { 5478 i++; 5479 break; 5480 } 5481 if (arg[0] != '-') 5482 break; 5483 5484 /* 5485 * All other arguments are single-character options that can 5486 * be combined, so we need to search through `arg` for them. 5487 */ 5488 arglen = strlen(arg); 5489 for (j = 1; j < arglen; j++) { 5490 opt = arg[j]; 5491 if (opt == 'h') { 5492 print_usage(argv[0]); 5493 _exit(0); 5494 } else if (opt == 'f') { 5495 /* 5496 * -f XX can be used to specify a descriptor for the 5497 * binary named at the command line (i.e., the later 5498 * argument will specify the process name but the 5499 * descriptor is what will actually be executed) 5500 */ 5501 if (j != arglen - 1) { 5502 /* -f must be the last option in, e.g., -abcf */ 5503 _rtld_error("Invalid options: %s", arg); 5504 rtld_die(); 5505 } 5506 i++; 5507 fd = parse_integer(argv[i]); 5508 if (fd == -1) { 5509 _rtld_error("Invalid file descriptor: '%s'", 5510 argv[i]); 5511 rtld_die(); 5512 } 5513 *fdp = fd; 5514 break; 5515 } else if (opt == 'p') { 5516 *use_pathp = true; 5517 } else { 5518 _rtld_error("Invalid argument: '%s'", arg); 5519 print_usage(argv[0]); 5520 rtld_die(); 5521 } 5522 } 5523 } 5524 5525 return (i); 5526 } 5527 5528 /* 5529 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5530 */ 5531 static int 5532 parse_integer(const char *str) 5533 { 5534 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5535 const char *orig; 5536 int n; 5537 char c; 5538 5539 orig = str; 5540 n = 0; 5541 for (c = *str; c != '\0'; c = *++str) { 5542 if (c < '0' || c > '9') 5543 return (-1); 5544 5545 n *= RADIX; 5546 n += c - '0'; 5547 } 5548 5549 /* Make sure we actually parsed something. */ 5550 if (str == orig) 5551 return (-1); 5552 return (n); 5553 } 5554 5555 static void 5556 print_usage(const char *argv0) 5557 { 5558 5559 rtld_printf("Usage: %s [-h] [-f <FD>] [--] <binary> [<args>]\n" 5560 "\n" 5561 "Options:\n" 5562 " -h Display this help message\n" 5563 " -p Search in PATH for named binary\n" 5564 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5565 " -- End of RTLD options\n" 5566 " <binary> Name of process to execute\n" 5567 " <args> Arguments to the executed process\n", argv0); 5568 } 5569 5570 /* 5571 * Overrides for libc_pic-provided functions. 5572 */ 5573 5574 int 5575 __getosreldate(void) 5576 { 5577 size_t len; 5578 int oid[2]; 5579 int error, osrel; 5580 5581 if (osreldate != 0) 5582 return (osreldate); 5583 5584 oid[0] = CTL_KERN; 5585 oid[1] = KERN_OSRELDATE; 5586 osrel = 0; 5587 len = sizeof(osrel); 5588 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5589 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5590 osreldate = osrel; 5591 return (osreldate); 5592 } 5593 5594 void 5595 exit(int status) 5596 { 5597 5598 _exit(status); 5599 } 5600 5601 void (*__cleanup)(void); 5602 int __isthreaded = 0; 5603 int _thread_autoinit_dummy_decl = 1; 5604 5605 /* 5606 * No unresolved symbols for rtld. 5607 */ 5608 void 5609 __pthread_cxa_finalize(struct dl_phdr_info *a __unused) 5610 { 5611 } 5612 5613 const char * 5614 rtld_strerror(int errnum) 5615 { 5616 5617 if (errnum < 0 || errnum >= sys_nerr) 5618 return ("Unknown error"); 5619 return (sys_errlist[errnum]); 5620 } 5621