1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <[email protected]>. 6 * Copyright 2009-2013 Konstantin Belousov <[email protected]>. 7 * Copyright 2012 John Marino <[email protected]>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <[email protected]>. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/uio.h> 50 #include <sys/utsname.h> 51 #include <sys/ktrace.h> 52 53 #include <dlfcn.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "debug.h" 64 #include "rtld.h" 65 #include "libmap.h" 66 #include "paths.h" 67 #include "rtld_tls.h" 68 #include "rtld_printf.h" 69 #include "rtld_malloc.h" 70 #include "rtld_utrace.h" 71 #include "notes.h" 72 73 /* Types. */ 74 typedef void (*func_ptr_type)(void); 75 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 76 77 78 /* Variables that cannot be static: */ 79 extern struct r_debug r_debug; /* For GDB */ 80 extern int _thread_autoinit_dummy_decl; 81 extern char* __progname; 82 extern void (*__cleanup)(void); 83 84 85 /* 86 * Function declarations. 87 */ 88 static const char *basename(const char *); 89 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 90 const Elf_Dyn **, const Elf_Dyn **); 91 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 92 const Elf_Dyn *); 93 static void digest_dynamic(Obj_Entry *, int); 94 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 95 static void distribute_static_tls(Objlist *, RtldLockState *); 96 static Obj_Entry *dlcheck(void *); 97 static int dlclose_locked(void *, RtldLockState *); 98 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 99 int lo_flags, int mode, RtldLockState *lockstate); 100 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 101 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 102 static bool donelist_check(DoneList *, const Obj_Entry *); 103 static void errmsg_restore(char *); 104 static char *errmsg_save(void); 105 static void *fill_search_info(const char *, size_t, void *); 106 static char *find_library(const char *, const Obj_Entry *, int *); 107 static const char *gethints(bool); 108 static void hold_object(Obj_Entry *); 109 static void unhold_object(Obj_Entry *); 110 static void init_dag(Obj_Entry *); 111 static void init_marker(Obj_Entry *); 112 static void init_pagesizes(Elf_Auxinfo **aux_info); 113 static void init_rtld(caddr_t, Elf_Auxinfo **); 114 static void initlist_add_neededs(Needed_Entry *, Objlist *); 115 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 116 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 117 static void linkmap_add(Obj_Entry *); 118 static void linkmap_delete(Obj_Entry *); 119 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 120 static void unload_filtees(Obj_Entry *, RtldLockState *); 121 static int load_needed_objects(Obj_Entry *, int); 122 static int load_preload_objects(void); 123 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 124 static void map_stacks_exec(RtldLockState *); 125 static int obj_disable_relro(Obj_Entry *); 126 static int obj_enforce_relro(Obj_Entry *); 127 static Obj_Entry *obj_from_addr(const void *); 128 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 129 static void objlist_call_init(Objlist *, RtldLockState *); 130 static void objlist_clear(Objlist *); 131 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 132 static void objlist_init(Objlist *); 133 static void objlist_push_head(Objlist *, Obj_Entry *); 134 static void objlist_push_tail(Objlist *, Obj_Entry *); 135 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 136 static void objlist_remove(Objlist *, Obj_Entry *); 137 static int open_binary_fd(const char *argv0, bool search_in_path); 138 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp); 139 static int parse_integer(const char *); 140 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 141 static void print_usage(const char *argv0); 142 static void release_object(Obj_Entry *); 143 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 144 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 145 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 146 int flags, RtldLockState *lockstate); 147 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 148 RtldLockState *); 149 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 150 static int rtld_dirname(const char *, char *); 151 static int rtld_dirname_abs(const char *, char *); 152 static void *rtld_dlopen(const char *name, int fd, int mode); 153 static void rtld_exit(void); 154 static void rtld_nop_exit(void); 155 static char *search_library_path(const char *, const char *, const char *, 156 int *); 157 static char *search_library_pathfds(const char *, const char *, int *); 158 static const void **get_program_var_addr(const char *, RtldLockState *); 159 static void set_program_var(const char *, const void *); 160 static int symlook_default(SymLook *, const Obj_Entry *refobj); 161 static int symlook_global(SymLook *, DoneList *); 162 static void symlook_init_from_req(SymLook *, const SymLook *); 163 static int symlook_list(SymLook *, const Objlist *, DoneList *); 164 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 165 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 166 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 167 static void trace_loaded_objects(Obj_Entry *); 168 static void unlink_object(Obj_Entry *); 169 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 170 static void unref_dag(Obj_Entry *); 171 static void ref_dag(Obj_Entry *); 172 static char *origin_subst_one(Obj_Entry *, char *, const char *, 173 const char *, bool); 174 static char *origin_subst(Obj_Entry *, const char *); 175 static bool obj_resolve_origin(Obj_Entry *obj); 176 static void preinit_main(void); 177 static int rtld_verify_versions(const Objlist *); 178 static int rtld_verify_object_versions(Obj_Entry *); 179 static void object_add_name(Obj_Entry *, const char *); 180 static int object_match_name(const Obj_Entry *, const char *); 181 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 182 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 183 struct dl_phdr_info *phdr_info); 184 static uint32_t gnu_hash(const char *); 185 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 186 const unsigned long); 187 188 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 189 void _r_debug_postinit(struct link_map *) __noinline __exported; 190 191 int __sys_openat(int, const char *, int, ...); 192 193 /* 194 * Data declarations. 195 */ 196 static char *error_message; /* Message for dlerror(), or NULL */ 197 struct r_debug r_debug __exported; /* for GDB; */ 198 static bool libmap_disable; /* Disable libmap */ 199 static bool ld_loadfltr; /* Immediate filters processing */ 200 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 201 static bool trust; /* False for setuid and setgid programs */ 202 static bool dangerous_ld_env; /* True if environment variables have been 203 used to affect the libraries loaded */ 204 bool ld_bind_not; /* Disable PLT update */ 205 static char *ld_bind_now; /* Environment variable for immediate binding */ 206 static char *ld_debug; /* Environment variable for debugging */ 207 static char *ld_library_path; /* Environment variable for search path */ 208 static char *ld_library_dirs; /* Environment variable for library descriptors */ 209 static char *ld_preload; /* Environment variable for libraries to 210 load first */ 211 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 212 static const char *ld_tracing; /* Called from ldd to print libs */ 213 static char *ld_utrace; /* Use utrace() to log events. */ 214 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 215 static Obj_Entry *obj_main; /* The main program shared object */ 216 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 217 static unsigned int obj_count; /* Number of objects in obj_list */ 218 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 219 220 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 221 STAILQ_HEAD_INITIALIZER(list_global); 222 static Objlist list_main = /* Objects loaded at program startup */ 223 STAILQ_HEAD_INITIALIZER(list_main); 224 static Objlist list_fini = /* Objects needing fini() calls */ 225 STAILQ_HEAD_INITIALIZER(list_fini); 226 227 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 228 229 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 230 231 extern Elf_Dyn _DYNAMIC; 232 #pragma weak _DYNAMIC 233 234 int dlclose(void *) __exported; 235 char *dlerror(void) __exported; 236 void *dlopen(const char *, int) __exported; 237 void *fdlopen(int, int) __exported; 238 void *dlsym(void *, const char *) __exported; 239 dlfunc_t dlfunc(void *, const char *) __exported; 240 void *dlvsym(void *, const char *, const char *) __exported; 241 int dladdr(const void *, Dl_info *) __exported; 242 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 243 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 244 int dlinfo(void *, int , void *) __exported; 245 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 246 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 247 int _rtld_get_stack_prot(void) __exported; 248 int _rtld_is_dlopened(void *) __exported; 249 void _rtld_error(const char *, ...) __exported; 250 251 /* Only here to fix -Wmissing-prototypes warnings */ 252 int __getosreldate(void); 253 void __pthread_cxa_finalize(struct dl_phdr_info *a); 254 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 255 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 256 257 258 int npagesizes; 259 static int osreldate; 260 size_t *pagesizes; 261 262 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 263 static int max_stack_flags; 264 265 /* 266 * Global declarations normally provided by crt1. The dynamic linker is 267 * not built with crt1, so we have to provide them ourselves. 268 */ 269 char *__progname; 270 char **environ; 271 272 /* 273 * Used to pass argc, argv to init functions. 274 */ 275 int main_argc; 276 char **main_argv; 277 278 /* 279 * Globals to control TLS allocation. 280 */ 281 size_t tls_last_offset; /* Static TLS offset of last module */ 282 size_t tls_last_size; /* Static TLS size of last module */ 283 size_t tls_static_space; /* Static TLS space allocated */ 284 static size_t tls_static_max_align; 285 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 286 int tls_max_index = 1; /* Largest module index allocated */ 287 288 static bool ld_library_path_rpath = false; 289 290 /* 291 * Globals for path names, and such 292 */ 293 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 294 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 295 const char *ld_path_rtld = _PATH_RTLD; 296 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 297 const char *ld_env_prefix = LD_; 298 299 static void (*rtld_exit_ptr)(void); 300 301 /* 302 * Fill in a DoneList with an allocation large enough to hold all of 303 * the currently-loaded objects. Keep this as a macro since it calls 304 * alloca and we want that to occur within the scope of the caller. 305 */ 306 #define donelist_init(dlp) \ 307 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 308 assert((dlp)->objs != NULL), \ 309 (dlp)->num_alloc = obj_count, \ 310 (dlp)->num_used = 0) 311 312 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 313 if (ld_utrace != NULL) \ 314 ld_utrace_log(e, h, mb, ms, r, n); \ 315 } while (0) 316 317 static void 318 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 319 int refcnt, const char *name) 320 { 321 struct utrace_rtld ut; 322 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 323 324 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 325 ut.event = event; 326 ut.handle = handle; 327 ut.mapbase = mapbase; 328 ut.mapsize = mapsize; 329 ut.refcnt = refcnt; 330 bzero(ut.name, sizeof(ut.name)); 331 if (name) 332 strlcpy(ut.name, name, sizeof(ut.name)); 333 utrace(&ut, sizeof(ut)); 334 } 335 336 #ifdef RTLD_VARIANT_ENV_NAMES 337 /* 338 * construct the env variable based on the type of binary that's 339 * running. 340 */ 341 static inline const char * 342 _LD(const char *var) 343 { 344 static char buffer[128]; 345 346 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 347 strlcat(buffer, var, sizeof(buffer)); 348 return (buffer); 349 } 350 #else 351 #define _LD(x) LD_ x 352 #endif 353 354 /* 355 * Main entry point for dynamic linking. The first argument is the 356 * stack pointer. The stack is expected to be laid out as described 357 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 358 * Specifically, the stack pointer points to a word containing 359 * ARGC. Following that in the stack is a null-terminated sequence 360 * of pointers to argument strings. Then comes a null-terminated 361 * sequence of pointers to environment strings. Finally, there is a 362 * sequence of "auxiliary vector" entries. 363 * 364 * The second argument points to a place to store the dynamic linker's 365 * exit procedure pointer and the third to a place to store the main 366 * program's object. 367 * 368 * The return value is the main program's entry point. 369 */ 370 func_ptr_type 371 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 372 { 373 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 374 Objlist_Entry *entry; 375 Obj_Entry *last_interposer, *obj, *preload_tail; 376 const Elf_Phdr *phdr; 377 Objlist initlist; 378 RtldLockState lockstate; 379 struct stat st; 380 Elf_Addr *argcp; 381 char **argv, **env, **envp, *kexecpath, *library_path_rpath; 382 const char *argv0; 383 caddr_t imgentry; 384 char buf[MAXPATHLEN]; 385 int argc, fd, i, phnum, rtld_argc; 386 bool dir_enable, explicit_fd, search_in_path; 387 388 /* 389 * On entry, the dynamic linker itself has not been relocated yet. 390 * Be very careful not to reference any global data until after 391 * init_rtld has returned. It is OK to reference file-scope statics 392 * and string constants, and to call static and global functions. 393 */ 394 395 /* Find the auxiliary vector on the stack. */ 396 argcp = sp; 397 argc = *sp++; 398 argv = (char **) sp; 399 sp += argc + 1; /* Skip over arguments and NULL terminator */ 400 env = (char **) sp; 401 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 402 ; 403 aux = (Elf_Auxinfo *) sp; 404 405 /* Digest the auxiliary vector. */ 406 for (i = 0; i < AT_COUNT; i++) 407 aux_info[i] = NULL; 408 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 409 if (auxp->a_type < AT_COUNT) 410 aux_info[auxp->a_type] = auxp; 411 } 412 413 /* Initialize and relocate ourselves. */ 414 assert(aux_info[AT_BASE] != NULL); 415 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 416 417 __progname = obj_rtld.path; 418 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 419 environ = env; 420 main_argc = argc; 421 main_argv = argv; 422 423 trust = !issetugid(); 424 425 md_abi_variant_hook(aux_info); 426 427 fd = -1; 428 if (aux_info[AT_EXECFD] != NULL) { 429 fd = aux_info[AT_EXECFD]->a_un.a_val; 430 } else { 431 assert(aux_info[AT_PHDR] != NULL); 432 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 433 if (phdr == obj_rtld.phdr) { 434 if (!trust) { 435 _rtld_error("Tainted process refusing to run binary %s", 436 argv0); 437 rtld_die(); 438 } 439 dbg("opening main program in direct exec mode"); 440 if (argc >= 2) { 441 rtld_argc = parse_args(argv, argc, &search_in_path, &fd); 442 argv0 = argv[rtld_argc]; 443 explicit_fd = (fd != -1); 444 if (!explicit_fd) 445 fd = open_binary_fd(argv0, search_in_path); 446 if (fstat(fd, &st) == -1) { 447 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 448 explicit_fd ? "user-provided descriptor" : argv0, 449 rtld_strerror(errno)); 450 rtld_die(); 451 } 452 453 /* 454 * Rough emulation of the permission checks done by 455 * execve(2), only Unix DACs are checked, ACLs are 456 * ignored. Preserve the semantic of disabling owner 457 * to execute if owner x bit is cleared, even if 458 * others x bit is enabled. 459 * mmap(2) does not allow to mmap with PROT_EXEC if 460 * binary' file comes from noexec mount. We cannot 461 * set a text reference on the binary. 462 */ 463 dir_enable = false; 464 if (st.st_uid == geteuid()) { 465 if ((st.st_mode & S_IXUSR) != 0) 466 dir_enable = true; 467 } else if (st.st_gid == getegid()) { 468 if ((st.st_mode & S_IXGRP) != 0) 469 dir_enable = true; 470 } else if ((st.st_mode & S_IXOTH) != 0) { 471 dir_enable = true; 472 } 473 if (!dir_enable) { 474 _rtld_error("No execute permission for binary %s", 475 argv0); 476 rtld_die(); 477 } 478 479 /* 480 * For direct exec mode, argv[0] is the interpreter 481 * name, we must remove it and shift arguments left 482 * before invoking binary main. Since stack layout 483 * places environment pointers and aux vectors right 484 * after the terminating NULL, we must shift 485 * environment and aux as well. 486 */ 487 main_argc = argc - rtld_argc; 488 for (i = 0; i <= main_argc; i++) 489 argv[i] = argv[i + rtld_argc]; 490 *argcp -= rtld_argc; 491 environ = env = envp = argv + main_argc + 1; 492 do { 493 *envp = *(envp + rtld_argc); 494 envp++; 495 } while (*envp != NULL); 496 aux = auxp = (Elf_Auxinfo *)envp; 497 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 498 for (;; auxp++, auxpf++) { 499 *auxp = *auxpf; 500 if (auxp->a_type == AT_NULL) 501 break; 502 } 503 } else { 504 _rtld_error("No binary"); 505 rtld_die(); 506 } 507 } 508 } 509 510 ld_bind_now = getenv(_LD("BIND_NOW")); 511 512 /* 513 * If the process is tainted, then we un-set the dangerous environment 514 * variables. The process will be marked as tainted until setuid(2) 515 * is called. If any child process calls setuid(2) we do not want any 516 * future processes to honor the potentially un-safe variables. 517 */ 518 if (!trust) { 519 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 520 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 521 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 522 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 523 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) { 524 _rtld_error("environment corrupt; aborting"); 525 rtld_die(); 526 } 527 } 528 ld_debug = getenv(_LD("DEBUG")); 529 if (ld_bind_now == NULL) 530 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 531 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 532 libmap_override = getenv(_LD("LIBMAP")); 533 ld_library_path = getenv(_LD("LIBRARY_PATH")); 534 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 535 ld_preload = getenv(_LD("PRELOAD")); 536 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 537 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 538 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 539 if (library_path_rpath != NULL) { 540 if (library_path_rpath[0] == 'y' || 541 library_path_rpath[0] == 'Y' || 542 library_path_rpath[0] == '1') 543 ld_library_path_rpath = true; 544 else 545 ld_library_path_rpath = false; 546 } 547 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 548 (ld_library_path != NULL) || (ld_preload != NULL) || 549 (ld_elf_hints_path != NULL) || ld_loadfltr; 550 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 551 ld_utrace = getenv(_LD("UTRACE")); 552 553 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 554 ld_elf_hints_path = ld_elf_hints_default; 555 556 if (ld_debug != NULL && *ld_debug != '\0') 557 debug = 1; 558 dbg("%s is initialized, base address = %p", __progname, 559 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 560 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 561 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 562 563 dbg("initializing thread locks"); 564 lockdflt_init(); 565 566 /* 567 * Load the main program, or process its program header if it is 568 * already loaded. 569 */ 570 if (fd != -1) { /* Load the main program. */ 571 dbg("loading main program"); 572 obj_main = map_object(fd, argv0, NULL); 573 close(fd); 574 if (obj_main == NULL) 575 rtld_die(); 576 max_stack_flags = obj_main->stack_flags; 577 } else { /* Main program already loaded. */ 578 dbg("processing main program's program header"); 579 assert(aux_info[AT_PHDR] != NULL); 580 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 581 assert(aux_info[AT_PHNUM] != NULL); 582 phnum = aux_info[AT_PHNUM]->a_un.a_val; 583 assert(aux_info[AT_PHENT] != NULL); 584 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 585 assert(aux_info[AT_ENTRY] != NULL); 586 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 587 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 588 rtld_die(); 589 } 590 591 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 592 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 593 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 594 if (kexecpath[0] == '/') 595 obj_main->path = kexecpath; 596 else if (getcwd(buf, sizeof(buf)) == NULL || 597 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 598 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 599 obj_main->path = xstrdup(argv0); 600 else 601 obj_main->path = xstrdup(buf); 602 } else { 603 dbg("No AT_EXECPATH or direct exec"); 604 obj_main->path = xstrdup(argv0); 605 } 606 dbg("obj_main path %s", obj_main->path); 607 obj_main->mainprog = true; 608 609 if (aux_info[AT_STACKPROT] != NULL && 610 aux_info[AT_STACKPROT]->a_un.a_val != 0) 611 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 612 613 #ifndef COMPAT_32BIT 614 /* 615 * Get the actual dynamic linker pathname from the executable if 616 * possible. (It should always be possible.) That ensures that 617 * gdb will find the right dynamic linker even if a non-standard 618 * one is being used. 619 */ 620 if (obj_main->interp != NULL && 621 strcmp(obj_main->interp, obj_rtld.path) != 0) { 622 free(obj_rtld.path); 623 obj_rtld.path = xstrdup(obj_main->interp); 624 __progname = obj_rtld.path; 625 } 626 #endif 627 628 digest_dynamic(obj_main, 0); 629 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 630 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 631 obj_main->dynsymcount); 632 633 linkmap_add(obj_main); 634 linkmap_add(&obj_rtld); 635 636 /* Link the main program into the list of objects. */ 637 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 638 obj_count++; 639 obj_loads++; 640 641 /* Initialize a fake symbol for resolving undefined weak references. */ 642 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 643 sym_zero.st_shndx = SHN_UNDEF; 644 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 645 646 if (!libmap_disable) 647 libmap_disable = (bool)lm_init(libmap_override); 648 649 dbg("loading LD_PRELOAD libraries"); 650 if (load_preload_objects() == -1) 651 rtld_die(); 652 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 653 654 dbg("loading needed objects"); 655 if (load_needed_objects(obj_main, 0) == -1) 656 rtld_die(); 657 658 /* Make a list of all objects loaded at startup. */ 659 last_interposer = obj_main; 660 TAILQ_FOREACH(obj, &obj_list, next) { 661 if (obj->marker) 662 continue; 663 if (obj->z_interpose && obj != obj_main) { 664 objlist_put_after(&list_main, last_interposer, obj); 665 last_interposer = obj; 666 } else { 667 objlist_push_tail(&list_main, obj); 668 } 669 obj->refcount++; 670 } 671 672 dbg("checking for required versions"); 673 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 674 rtld_die(); 675 676 if (ld_tracing) { /* We're done */ 677 trace_loaded_objects(obj_main); 678 exit(0); 679 } 680 681 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 682 dump_relocations(obj_main); 683 exit (0); 684 } 685 686 /* 687 * Processing tls relocations requires having the tls offsets 688 * initialized. Prepare offsets before starting initial 689 * relocation processing. 690 */ 691 dbg("initializing initial thread local storage offsets"); 692 STAILQ_FOREACH(entry, &list_main, link) { 693 /* 694 * Allocate all the initial objects out of the static TLS 695 * block even if they didn't ask for it. 696 */ 697 allocate_tls_offset(entry->obj); 698 } 699 700 if (relocate_objects(obj_main, 701 ld_bind_now != NULL && *ld_bind_now != '\0', 702 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 703 rtld_die(); 704 705 dbg("doing copy relocations"); 706 if (do_copy_relocations(obj_main) == -1) 707 rtld_die(); 708 709 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 710 dump_relocations(obj_main); 711 exit (0); 712 } 713 714 ifunc_init(aux); 715 716 /* 717 * Setup TLS for main thread. This must be done after the 718 * relocations are processed, since tls initialization section 719 * might be the subject for relocations. 720 */ 721 dbg("initializing initial thread local storage"); 722 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 723 724 dbg("initializing key program variables"); 725 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 726 set_program_var("environ", env); 727 set_program_var("__elf_aux_vector", aux); 728 729 /* Make a list of init functions to call. */ 730 objlist_init(&initlist); 731 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 732 preload_tail, &initlist); 733 734 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 735 736 map_stacks_exec(NULL); 737 738 if (!obj_main->crt_no_init) { 739 /* 740 * Make sure we don't call the main program's init and fini 741 * functions for binaries linked with old crt1 which calls 742 * _init itself. 743 */ 744 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 745 obj_main->preinit_array = obj_main->init_array = 746 obj_main->fini_array = (Elf_Addr)NULL; 747 } 748 749 /* 750 * Execute MD initializers required before we call the objects' 751 * init functions. 752 */ 753 pre_init(); 754 755 wlock_acquire(rtld_bind_lock, &lockstate); 756 757 dbg("resolving ifuncs"); 758 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 759 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 760 rtld_die(); 761 762 rtld_exit_ptr = rtld_exit; 763 if (obj_main->crt_no_init) 764 preinit_main(); 765 objlist_call_init(&initlist, &lockstate); 766 _r_debug_postinit(&obj_main->linkmap); 767 objlist_clear(&initlist); 768 dbg("loading filtees"); 769 TAILQ_FOREACH(obj, &obj_list, next) { 770 if (obj->marker) 771 continue; 772 if (ld_loadfltr || obj->z_loadfltr) 773 load_filtees(obj, 0, &lockstate); 774 } 775 776 dbg("enforcing main obj relro"); 777 if (obj_enforce_relro(obj_main) == -1) 778 rtld_die(); 779 780 lock_release(rtld_bind_lock, &lockstate); 781 782 dbg("transferring control to program entry point = %p", obj_main->entry); 783 784 /* Return the exit procedure and the program entry point. */ 785 *exit_proc = rtld_exit_ptr; 786 *objp = obj_main; 787 return (func_ptr_type) obj_main->entry; 788 } 789 790 void * 791 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 792 { 793 void *ptr; 794 Elf_Addr target; 795 796 ptr = (void *)make_function_pointer(def, obj); 797 target = call_ifunc_resolver(ptr); 798 return ((void *)target); 799 } 800 801 /* 802 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 803 * Changes to this function should be applied there as well. 804 */ 805 Elf_Addr 806 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 807 { 808 const Elf_Rel *rel; 809 const Elf_Sym *def; 810 const Obj_Entry *defobj; 811 Elf_Addr *where; 812 Elf_Addr target; 813 RtldLockState lockstate; 814 815 rlock_acquire(rtld_bind_lock, &lockstate); 816 if (sigsetjmp(lockstate.env, 0) != 0) 817 lock_upgrade(rtld_bind_lock, &lockstate); 818 if (obj->pltrel) 819 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 820 else 821 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 822 823 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 824 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 825 NULL, &lockstate); 826 if (def == NULL) 827 rtld_die(); 828 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 829 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 830 else 831 target = (Elf_Addr)(defobj->relocbase + def->st_value); 832 833 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 834 defobj->strtab + def->st_name, basename(obj->path), 835 (void *)target, basename(defobj->path)); 836 837 /* 838 * Write the new contents for the jmpslot. Note that depending on 839 * architecture, the value which we need to return back to the 840 * lazy binding trampoline may or may not be the target 841 * address. The value returned from reloc_jmpslot() is the value 842 * that the trampoline needs. 843 */ 844 target = reloc_jmpslot(where, target, defobj, obj, rel); 845 lock_release(rtld_bind_lock, &lockstate); 846 return target; 847 } 848 849 /* 850 * Error reporting function. Use it like printf. If formats the message 851 * into a buffer, and sets things up so that the next call to dlerror() 852 * will return the message. 853 */ 854 void 855 _rtld_error(const char *fmt, ...) 856 { 857 static char buf[512]; 858 va_list ap; 859 860 va_start(ap, fmt); 861 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 862 error_message = buf; 863 va_end(ap); 864 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message); 865 } 866 867 /* 868 * Return a dynamically-allocated copy of the current error message, if any. 869 */ 870 static char * 871 errmsg_save(void) 872 { 873 return error_message == NULL ? NULL : xstrdup(error_message); 874 } 875 876 /* 877 * Restore the current error message from a copy which was previously saved 878 * by errmsg_save(). The copy is freed. 879 */ 880 static void 881 errmsg_restore(char *saved_msg) 882 { 883 if (saved_msg == NULL) 884 error_message = NULL; 885 else { 886 _rtld_error("%s", saved_msg); 887 free(saved_msg); 888 } 889 } 890 891 static const char * 892 basename(const char *name) 893 { 894 const char *p = strrchr(name, '/'); 895 return p != NULL ? p + 1 : name; 896 } 897 898 static struct utsname uts; 899 900 static char * 901 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 902 const char *subst, bool may_free) 903 { 904 char *p, *p1, *res, *resp; 905 int subst_len, kw_len, subst_count, old_len, new_len; 906 907 kw_len = strlen(kw); 908 909 /* 910 * First, count the number of the keyword occurrences, to 911 * preallocate the final string. 912 */ 913 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 914 p1 = strstr(p, kw); 915 if (p1 == NULL) 916 break; 917 } 918 919 /* 920 * If the keyword is not found, just return. 921 * 922 * Return non-substituted string if resolution failed. We 923 * cannot do anything more reasonable, the failure mode of the 924 * caller is unresolved library anyway. 925 */ 926 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 927 return (may_free ? real : xstrdup(real)); 928 if (obj != NULL) 929 subst = obj->origin_path; 930 931 /* 932 * There is indeed something to substitute. Calculate the 933 * length of the resulting string, and allocate it. 934 */ 935 subst_len = strlen(subst); 936 old_len = strlen(real); 937 new_len = old_len + (subst_len - kw_len) * subst_count; 938 res = xmalloc(new_len + 1); 939 940 /* 941 * Now, execute the substitution loop. 942 */ 943 for (p = real, resp = res, *resp = '\0';;) { 944 p1 = strstr(p, kw); 945 if (p1 != NULL) { 946 /* Copy the prefix before keyword. */ 947 memcpy(resp, p, p1 - p); 948 resp += p1 - p; 949 /* Keyword replacement. */ 950 memcpy(resp, subst, subst_len); 951 resp += subst_len; 952 *resp = '\0'; 953 p = p1 + kw_len; 954 } else 955 break; 956 } 957 958 /* Copy to the end of string and finish. */ 959 strcat(resp, p); 960 if (may_free) 961 free(real); 962 return (res); 963 } 964 965 static char * 966 origin_subst(Obj_Entry *obj, const char *real) 967 { 968 char *res1, *res2, *res3, *res4; 969 970 if (obj == NULL || !trust) 971 return (xstrdup(real)); 972 if (uts.sysname[0] == '\0') { 973 if (uname(&uts) != 0) { 974 _rtld_error("utsname failed: %d", errno); 975 return (NULL); 976 } 977 } 978 /* __DECONST is safe here since without may_free real is unchanged */ 979 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 980 false); 981 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 982 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 983 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 984 return (res4); 985 } 986 987 void 988 rtld_die(void) 989 { 990 const char *msg = dlerror(); 991 992 if (msg == NULL) 993 msg = "Fatal error"; 994 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 995 rtld_fdputstr(STDERR_FILENO, msg); 996 rtld_fdputchar(STDERR_FILENO, '\n'); 997 _exit(1); 998 } 999 1000 /* 1001 * Process a shared object's DYNAMIC section, and save the important 1002 * information in its Obj_Entry structure. 1003 */ 1004 static void 1005 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1006 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1007 { 1008 const Elf_Dyn *dynp; 1009 Needed_Entry **needed_tail = &obj->needed; 1010 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1011 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1012 const Elf_Hashelt *hashtab; 1013 const Elf32_Word *hashval; 1014 Elf32_Word bkt, nmaskwords; 1015 int bloom_size32; 1016 int plttype = DT_REL; 1017 1018 *dyn_rpath = NULL; 1019 *dyn_soname = NULL; 1020 *dyn_runpath = NULL; 1021 1022 obj->bind_now = false; 1023 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 1024 switch (dynp->d_tag) { 1025 1026 case DT_REL: 1027 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1028 break; 1029 1030 case DT_RELSZ: 1031 obj->relsize = dynp->d_un.d_val; 1032 break; 1033 1034 case DT_RELENT: 1035 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1036 break; 1037 1038 case DT_JMPREL: 1039 obj->pltrel = (const Elf_Rel *) 1040 (obj->relocbase + dynp->d_un.d_ptr); 1041 break; 1042 1043 case DT_PLTRELSZ: 1044 obj->pltrelsize = dynp->d_un.d_val; 1045 break; 1046 1047 case DT_RELA: 1048 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1049 break; 1050 1051 case DT_RELASZ: 1052 obj->relasize = dynp->d_un.d_val; 1053 break; 1054 1055 case DT_RELAENT: 1056 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1057 break; 1058 1059 case DT_PLTREL: 1060 plttype = dynp->d_un.d_val; 1061 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1062 break; 1063 1064 case DT_SYMTAB: 1065 obj->symtab = (const Elf_Sym *) 1066 (obj->relocbase + dynp->d_un.d_ptr); 1067 break; 1068 1069 case DT_SYMENT: 1070 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1071 break; 1072 1073 case DT_STRTAB: 1074 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1075 break; 1076 1077 case DT_STRSZ: 1078 obj->strsize = dynp->d_un.d_val; 1079 break; 1080 1081 case DT_VERNEED: 1082 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1083 dynp->d_un.d_val); 1084 break; 1085 1086 case DT_VERNEEDNUM: 1087 obj->verneednum = dynp->d_un.d_val; 1088 break; 1089 1090 case DT_VERDEF: 1091 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1092 dynp->d_un.d_val); 1093 break; 1094 1095 case DT_VERDEFNUM: 1096 obj->verdefnum = dynp->d_un.d_val; 1097 break; 1098 1099 case DT_VERSYM: 1100 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1101 dynp->d_un.d_val); 1102 break; 1103 1104 case DT_HASH: 1105 { 1106 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1107 dynp->d_un.d_ptr); 1108 obj->nbuckets = hashtab[0]; 1109 obj->nchains = hashtab[1]; 1110 obj->buckets = hashtab + 2; 1111 obj->chains = obj->buckets + obj->nbuckets; 1112 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1113 obj->buckets != NULL; 1114 } 1115 break; 1116 1117 case DT_GNU_HASH: 1118 { 1119 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1120 dynp->d_un.d_ptr); 1121 obj->nbuckets_gnu = hashtab[0]; 1122 obj->symndx_gnu = hashtab[1]; 1123 nmaskwords = hashtab[2]; 1124 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1125 obj->maskwords_bm_gnu = nmaskwords - 1; 1126 obj->shift2_gnu = hashtab[3]; 1127 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1128 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1129 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1130 obj->symndx_gnu; 1131 /* Number of bitmask words is required to be power of 2 */ 1132 obj->valid_hash_gnu = powerof2(nmaskwords) && 1133 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1134 } 1135 break; 1136 1137 case DT_NEEDED: 1138 if (!obj->rtld) { 1139 Needed_Entry *nep = NEW(Needed_Entry); 1140 nep->name = dynp->d_un.d_val; 1141 nep->obj = NULL; 1142 nep->next = NULL; 1143 1144 *needed_tail = nep; 1145 needed_tail = &nep->next; 1146 } 1147 break; 1148 1149 case DT_FILTER: 1150 if (!obj->rtld) { 1151 Needed_Entry *nep = NEW(Needed_Entry); 1152 nep->name = dynp->d_un.d_val; 1153 nep->obj = NULL; 1154 nep->next = NULL; 1155 1156 *needed_filtees_tail = nep; 1157 needed_filtees_tail = &nep->next; 1158 } 1159 break; 1160 1161 case DT_AUXILIARY: 1162 if (!obj->rtld) { 1163 Needed_Entry *nep = NEW(Needed_Entry); 1164 nep->name = dynp->d_un.d_val; 1165 nep->obj = NULL; 1166 nep->next = NULL; 1167 1168 *needed_aux_filtees_tail = nep; 1169 needed_aux_filtees_tail = &nep->next; 1170 } 1171 break; 1172 1173 case DT_PLTGOT: 1174 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1175 break; 1176 1177 case DT_TEXTREL: 1178 obj->textrel = true; 1179 break; 1180 1181 case DT_SYMBOLIC: 1182 obj->symbolic = true; 1183 break; 1184 1185 case DT_RPATH: 1186 /* 1187 * We have to wait until later to process this, because we 1188 * might not have gotten the address of the string table yet. 1189 */ 1190 *dyn_rpath = dynp; 1191 break; 1192 1193 case DT_SONAME: 1194 *dyn_soname = dynp; 1195 break; 1196 1197 case DT_RUNPATH: 1198 *dyn_runpath = dynp; 1199 break; 1200 1201 case DT_INIT: 1202 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1203 break; 1204 1205 case DT_PREINIT_ARRAY: 1206 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1207 break; 1208 1209 case DT_PREINIT_ARRAYSZ: 1210 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1211 break; 1212 1213 case DT_INIT_ARRAY: 1214 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1215 break; 1216 1217 case DT_INIT_ARRAYSZ: 1218 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1219 break; 1220 1221 case DT_FINI: 1222 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1223 break; 1224 1225 case DT_FINI_ARRAY: 1226 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1227 break; 1228 1229 case DT_FINI_ARRAYSZ: 1230 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1231 break; 1232 1233 /* 1234 * Don't process DT_DEBUG on MIPS as the dynamic section 1235 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1236 */ 1237 1238 #ifndef __mips__ 1239 case DT_DEBUG: 1240 if (!early) 1241 dbg("Filling in DT_DEBUG entry"); 1242 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1243 break; 1244 #endif 1245 1246 case DT_FLAGS: 1247 if (dynp->d_un.d_val & DF_ORIGIN) 1248 obj->z_origin = true; 1249 if (dynp->d_un.d_val & DF_SYMBOLIC) 1250 obj->symbolic = true; 1251 if (dynp->d_un.d_val & DF_TEXTREL) 1252 obj->textrel = true; 1253 if (dynp->d_un.d_val & DF_BIND_NOW) 1254 obj->bind_now = true; 1255 if (dynp->d_un.d_val & DF_STATIC_TLS) 1256 obj->static_tls = true; 1257 break; 1258 #ifdef __mips__ 1259 case DT_MIPS_LOCAL_GOTNO: 1260 obj->local_gotno = dynp->d_un.d_val; 1261 break; 1262 1263 case DT_MIPS_SYMTABNO: 1264 obj->symtabno = dynp->d_un.d_val; 1265 break; 1266 1267 case DT_MIPS_GOTSYM: 1268 obj->gotsym = dynp->d_un.d_val; 1269 break; 1270 1271 case DT_MIPS_RLD_MAP: 1272 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (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 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1422 obj->vaddrbase; 1423 } else { /* Last load segment */ 1424 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1425 obj->vaddrbase; 1426 } 1427 nsegs++; 1428 break; 1429 1430 case PT_DYNAMIC: 1431 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1432 break; 1433 1434 case PT_TLS: 1435 obj->tlsindex = 1; 1436 obj->tlssize = ph->p_memsz; 1437 obj->tlsalign = ph->p_align; 1438 obj->tlsinitsize = ph->p_filesz; 1439 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1440 break; 1441 1442 case PT_GNU_STACK: 1443 obj->stack_flags = ph->p_flags; 1444 break; 1445 1446 case PT_GNU_RELRO: 1447 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1448 obj->relro_size = round_page(ph->p_memsz); 1449 break; 1450 1451 case PT_NOTE: 1452 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1453 note_end = note_start + ph->p_filesz; 1454 digest_notes(obj, note_start, note_end); 1455 break; 1456 } 1457 } 1458 if (nsegs < 1) { 1459 _rtld_error("%s: too few PT_LOAD segments", path); 1460 return NULL; 1461 } 1462 1463 obj->entry = entry; 1464 return obj; 1465 } 1466 1467 void 1468 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1469 { 1470 const Elf_Note *note; 1471 const char *note_name; 1472 uintptr_t p; 1473 1474 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1475 note = (const Elf_Note *)((const char *)(note + 1) + 1476 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1477 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1478 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1479 note->n_descsz != sizeof(int32_t)) 1480 continue; 1481 if (note->n_type != NT_FREEBSD_ABI_TAG && 1482 note->n_type != NT_FREEBSD_FEATURE_CTL && 1483 note->n_type != NT_FREEBSD_NOINIT_TAG) 1484 continue; 1485 note_name = (const char *)(note + 1); 1486 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1487 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1488 continue; 1489 switch (note->n_type) { 1490 case NT_FREEBSD_ABI_TAG: 1491 /* FreeBSD osrel note */ 1492 p = (uintptr_t)(note + 1); 1493 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1494 obj->osrel = *(const int32_t *)(p); 1495 dbg("note osrel %d", obj->osrel); 1496 break; 1497 case NT_FREEBSD_FEATURE_CTL: 1498 /* FreeBSD ABI feature control note */ 1499 p = (uintptr_t)(note + 1); 1500 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1501 obj->fctl0 = *(const uint32_t *)(p); 1502 dbg("note fctl0 %#x", obj->fctl0); 1503 break; 1504 case NT_FREEBSD_NOINIT_TAG: 1505 /* FreeBSD 'crt does not call init' note */ 1506 obj->crt_no_init = true; 1507 dbg("note crt_no_init"); 1508 break; 1509 } 1510 } 1511 } 1512 1513 static Obj_Entry * 1514 dlcheck(void *handle) 1515 { 1516 Obj_Entry *obj; 1517 1518 TAILQ_FOREACH(obj, &obj_list, next) { 1519 if (obj == (Obj_Entry *) handle) 1520 break; 1521 } 1522 1523 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1524 _rtld_error("Invalid shared object handle %p", handle); 1525 return NULL; 1526 } 1527 return obj; 1528 } 1529 1530 /* 1531 * If the given object is already in the donelist, return true. Otherwise 1532 * add the object to the list and return false. 1533 */ 1534 static bool 1535 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1536 { 1537 unsigned int i; 1538 1539 for (i = 0; i < dlp->num_used; i++) 1540 if (dlp->objs[i] == obj) 1541 return true; 1542 /* 1543 * Our donelist allocation should always be sufficient. But if 1544 * our threads locking isn't working properly, more shared objects 1545 * could have been loaded since we allocated the list. That should 1546 * never happen, but we'll handle it properly just in case it does. 1547 */ 1548 if (dlp->num_used < dlp->num_alloc) 1549 dlp->objs[dlp->num_used++] = obj; 1550 return false; 1551 } 1552 1553 /* 1554 * Hash function for symbol table lookup. Don't even think about changing 1555 * this. It is specified by the System V ABI. 1556 */ 1557 unsigned long 1558 elf_hash(const char *name) 1559 { 1560 const unsigned char *p = (const unsigned char *) name; 1561 unsigned long h = 0; 1562 unsigned long g; 1563 1564 while (*p != '\0') { 1565 h = (h << 4) + *p++; 1566 if ((g = h & 0xf0000000) != 0) 1567 h ^= g >> 24; 1568 h &= ~g; 1569 } 1570 return h; 1571 } 1572 1573 /* 1574 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1575 * unsigned in case it's implemented with a wider type. 1576 */ 1577 static uint32_t 1578 gnu_hash(const char *s) 1579 { 1580 uint32_t h; 1581 unsigned char c; 1582 1583 h = 5381; 1584 for (c = *s; c != '\0'; c = *++s) 1585 h = h * 33 + c; 1586 return (h & 0xffffffff); 1587 } 1588 1589 1590 /* 1591 * Find the library with the given name, and return its full pathname. 1592 * The returned string is dynamically allocated. Generates an error 1593 * message and returns NULL if the library cannot be found. 1594 * 1595 * If the second argument is non-NULL, then it refers to an already- 1596 * loaded shared object, whose library search path will be searched. 1597 * 1598 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1599 * descriptor (which is close-on-exec) will be passed out via the third 1600 * argument. 1601 * 1602 * The search order is: 1603 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1604 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1605 * LD_LIBRARY_PATH 1606 * DT_RUNPATH in the referencing file 1607 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1608 * from list) 1609 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1610 * 1611 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1612 */ 1613 static char * 1614 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1615 { 1616 char *pathname, *refobj_path; 1617 const char *name; 1618 bool nodeflib, objgiven; 1619 1620 objgiven = refobj != NULL; 1621 1622 if (libmap_disable || !objgiven || 1623 (name = lm_find(refobj->path, xname)) == NULL) 1624 name = xname; 1625 1626 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1627 if (name[0] != '/' && !trust) { 1628 _rtld_error("Absolute pathname required " 1629 "for shared object \"%s\"", name); 1630 return (NULL); 1631 } 1632 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1633 __DECONST(char *, name))); 1634 } 1635 1636 dbg(" Searching for \"%s\"", name); 1637 refobj_path = objgiven ? refobj->path : NULL; 1638 1639 /* 1640 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1641 * back to pre-conforming behaviour if user requested so with 1642 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1643 * nodeflib. 1644 */ 1645 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1646 pathname = search_library_path(name, ld_library_path, 1647 refobj_path, fdp); 1648 if (pathname != NULL) 1649 return (pathname); 1650 if (refobj != NULL) { 1651 pathname = search_library_path(name, refobj->rpath, 1652 refobj_path, fdp); 1653 if (pathname != NULL) 1654 return (pathname); 1655 } 1656 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1657 if (pathname != NULL) 1658 return (pathname); 1659 pathname = search_library_path(name, gethints(false), 1660 refobj_path, fdp); 1661 if (pathname != NULL) 1662 return (pathname); 1663 pathname = search_library_path(name, ld_standard_library_path, 1664 refobj_path, fdp); 1665 if (pathname != NULL) 1666 return (pathname); 1667 } else { 1668 nodeflib = objgiven ? refobj->z_nodeflib : false; 1669 if (objgiven) { 1670 pathname = search_library_path(name, refobj->rpath, 1671 refobj->path, fdp); 1672 if (pathname != NULL) 1673 return (pathname); 1674 } 1675 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1676 pathname = search_library_path(name, obj_main->rpath, 1677 refobj_path, fdp); 1678 if (pathname != NULL) 1679 return (pathname); 1680 } 1681 pathname = search_library_path(name, ld_library_path, 1682 refobj_path, fdp); 1683 if (pathname != NULL) 1684 return (pathname); 1685 if (objgiven) { 1686 pathname = search_library_path(name, refobj->runpath, 1687 refobj_path, fdp); 1688 if (pathname != NULL) 1689 return (pathname); 1690 } 1691 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1692 if (pathname != NULL) 1693 return (pathname); 1694 pathname = search_library_path(name, gethints(nodeflib), 1695 refobj_path, fdp); 1696 if (pathname != NULL) 1697 return (pathname); 1698 if (objgiven && !nodeflib) { 1699 pathname = search_library_path(name, 1700 ld_standard_library_path, refobj_path, fdp); 1701 if (pathname != NULL) 1702 return (pathname); 1703 } 1704 } 1705 1706 if (objgiven && refobj->path != NULL) { 1707 _rtld_error("Shared object \"%s\" not found, " 1708 "required by \"%s\"", name, basename(refobj->path)); 1709 } else { 1710 _rtld_error("Shared object \"%s\" not found", name); 1711 } 1712 return (NULL); 1713 } 1714 1715 /* 1716 * Given a symbol number in a referencing object, find the corresponding 1717 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1718 * no definition was found. Returns a pointer to the Obj_Entry of the 1719 * defining object via the reference parameter DEFOBJ_OUT. 1720 */ 1721 const Elf_Sym * 1722 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1723 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1724 RtldLockState *lockstate) 1725 { 1726 const Elf_Sym *ref; 1727 const Elf_Sym *def; 1728 const Obj_Entry *defobj; 1729 const Ver_Entry *ve; 1730 SymLook req; 1731 const char *name; 1732 int res; 1733 1734 /* 1735 * If we have already found this symbol, get the information from 1736 * the cache. 1737 */ 1738 if (symnum >= refobj->dynsymcount) 1739 return NULL; /* Bad object */ 1740 if (cache != NULL && cache[symnum].sym != NULL) { 1741 *defobj_out = cache[symnum].obj; 1742 return cache[symnum].sym; 1743 } 1744 1745 ref = refobj->symtab + symnum; 1746 name = refobj->strtab + ref->st_name; 1747 def = NULL; 1748 defobj = NULL; 1749 ve = NULL; 1750 1751 /* 1752 * We don't have to do a full scale lookup if the symbol is local. 1753 * We know it will bind to the instance in this load module; to 1754 * which we already have a pointer (ie ref). By not doing a lookup, 1755 * we not only improve performance, but it also avoids unresolvable 1756 * symbols when local symbols are not in the hash table. This has 1757 * been seen with the ia64 toolchain. 1758 */ 1759 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1760 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1761 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1762 symnum); 1763 } 1764 symlook_init(&req, name); 1765 req.flags = flags; 1766 ve = req.ventry = fetch_ventry(refobj, symnum); 1767 req.lockstate = lockstate; 1768 res = symlook_default(&req, refobj); 1769 if (res == 0) { 1770 def = req.sym_out; 1771 defobj = req.defobj_out; 1772 } 1773 } else { 1774 def = ref; 1775 defobj = refobj; 1776 } 1777 1778 /* 1779 * If we found no definition and the reference is weak, treat the 1780 * symbol as having the value zero. 1781 */ 1782 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1783 def = &sym_zero; 1784 defobj = obj_main; 1785 } 1786 1787 if (def != NULL) { 1788 *defobj_out = defobj; 1789 /* Record the information in the cache to avoid subsequent lookups. */ 1790 if (cache != NULL) { 1791 cache[symnum].sym = def; 1792 cache[symnum].obj = defobj; 1793 } 1794 } else { 1795 if (refobj != &obj_rtld) 1796 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1797 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1798 } 1799 return def; 1800 } 1801 1802 /* 1803 * Return the search path from the ldconfig hints file, reading it if 1804 * necessary. If nostdlib is true, then the default search paths are 1805 * not added to result. 1806 * 1807 * Returns NULL if there are problems with the hints file, 1808 * or if the search path there is empty. 1809 */ 1810 static const char * 1811 gethints(bool nostdlib) 1812 { 1813 static char *filtered_path; 1814 static const char *hints; 1815 static struct elfhints_hdr hdr; 1816 struct fill_search_info_args sargs, hargs; 1817 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1818 struct dl_serpath *SLPpath, *hintpath; 1819 char *p; 1820 struct stat hint_stat; 1821 unsigned int SLPndx, hintndx, fndx, fcount; 1822 int fd; 1823 size_t flen; 1824 uint32_t dl; 1825 bool skip; 1826 1827 /* First call, read the hints file */ 1828 if (hints == NULL) { 1829 /* Keep from trying again in case the hints file is bad. */ 1830 hints = ""; 1831 1832 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1833 return (NULL); 1834 1835 /* 1836 * Check of hdr.dirlistlen value against type limit 1837 * intends to pacify static analyzers. Further 1838 * paranoia leads to checks that dirlist is fully 1839 * contained in the file range. 1840 */ 1841 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1842 hdr.magic != ELFHINTS_MAGIC || 1843 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1844 fstat(fd, &hint_stat) == -1) { 1845 cleanup1: 1846 close(fd); 1847 hdr.dirlistlen = 0; 1848 return (NULL); 1849 } 1850 dl = hdr.strtab; 1851 if (dl + hdr.dirlist < dl) 1852 goto cleanup1; 1853 dl += hdr.dirlist; 1854 if (dl + hdr.dirlistlen < dl) 1855 goto cleanup1; 1856 dl += hdr.dirlistlen; 1857 if (dl > hint_stat.st_size) 1858 goto cleanup1; 1859 p = xmalloc(hdr.dirlistlen + 1); 1860 if (pread(fd, p, hdr.dirlistlen + 1, 1861 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1862 p[hdr.dirlistlen] != '\0') { 1863 free(p); 1864 goto cleanup1; 1865 } 1866 hints = p; 1867 close(fd); 1868 } 1869 1870 /* 1871 * If caller agreed to receive list which includes the default 1872 * paths, we are done. Otherwise, if we still did not 1873 * calculated filtered result, do it now. 1874 */ 1875 if (!nostdlib) 1876 return (hints[0] != '\0' ? hints : NULL); 1877 if (filtered_path != NULL) 1878 goto filt_ret; 1879 1880 /* 1881 * Obtain the list of all configured search paths, and the 1882 * list of the default paths. 1883 * 1884 * First estimate the size of the results. 1885 */ 1886 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1887 smeta.dls_cnt = 0; 1888 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1889 hmeta.dls_cnt = 0; 1890 1891 sargs.request = RTLD_DI_SERINFOSIZE; 1892 sargs.serinfo = &smeta; 1893 hargs.request = RTLD_DI_SERINFOSIZE; 1894 hargs.serinfo = &hmeta; 1895 1896 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1897 &sargs); 1898 path_enumerate(hints, fill_search_info, NULL, &hargs); 1899 1900 SLPinfo = xmalloc(smeta.dls_size); 1901 hintinfo = xmalloc(hmeta.dls_size); 1902 1903 /* 1904 * Next fetch both sets of paths. 1905 */ 1906 sargs.request = RTLD_DI_SERINFO; 1907 sargs.serinfo = SLPinfo; 1908 sargs.serpath = &SLPinfo->dls_serpath[0]; 1909 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1910 1911 hargs.request = RTLD_DI_SERINFO; 1912 hargs.serinfo = hintinfo; 1913 hargs.serpath = &hintinfo->dls_serpath[0]; 1914 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1915 1916 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1917 &sargs); 1918 path_enumerate(hints, fill_search_info, NULL, &hargs); 1919 1920 /* 1921 * Now calculate the difference between two sets, by excluding 1922 * standard paths from the full set. 1923 */ 1924 fndx = 0; 1925 fcount = 0; 1926 filtered_path = xmalloc(hdr.dirlistlen + 1); 1927 hintpath = &hintinfo->dls_serpath[0]; 1928 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1929 skip = false; 1930 SLPpath = &SLPinfo->dls_serpath[0]; 1931 /* 1932 * Check each standard path against current. 1933 */ 1934 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1935 /* matched, skip the path */ 1936 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1937 skip = true; 1938 break; 1939 } 1940 } 1941 if (skip) 1942 continue; 1943 /* 1944 * Not matched against any standard path, add the path 1945 * to result. Separate consequtive paths with ':'. 1946 */ 1947 if (fcount > 0) { 1948 filtered_path[fndx] = ':'; 1949 fndx++; 1950 } 1951 fcount++; 1952 flen = strlen(hintpath->dls_name); 1953 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1954 fndx += flen; 1955 } 1956 filtered_path[fndx] = '\0'; 1957 1958 free(SLPinfo); 1959 free(hintinfo); 1960 1961 filt_ret: 1962 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1963 } 1964 1965 static void 1966 init_dag(Obj_Entry *root) 1967 { 1968 const Needed_Entry *needed; 1969 const Objlist_Entry *elm; 1970 DoneList donelist; 1971 1972 if (root->dag_inited) 1973 return; 1974 donelist_init(&donelist); 1975 1976 /* Root object belongs to own DAG. */ 1977 objlist_push_tail(&root->dldags, root); 1978 objlist_push_tail(&root->dagmembers, root); 1979 donelist_check(&donelist, root); 1980 1981 /* 1982 * Add dependencies of root object to DAG in breadth order 1983 * by exploiting the fact that each new object get added 1984 * to the tail of the dagmembers list. 1985 */ 1986 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1987 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1988 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1989 continue; 1990 objlist_push_tail(&needed->obj->dldags, root); 1991 objlist_push_tail(&root->dagmembers, needed->obj); 1992 } 1993 } 1994 root->dag_inited = true; 1995 } 1996 1997 static void 1998 init_marker(Obj_Entry *marker) 1999 { 2000 2001 bzero(marker, sizeof(*marker)); 2002 marker->marker = true; 2003 } 2004 2005 Obj_Entry * 2006 globallist_curr(const Obj_Entry *obj) 2007 { 2008 2009 for (;;) { 2010 if (obj == NULL) 2011 return (NULL); 2012 if (!obj->marker) 2013 return (__DECONST(Obj_Entry *, obj)); 2014 obj = TAILQ_PREV(obj, obj_entry_q, next); 2015 } 2016 } 2017 2018 Obj_Entry * 2019 globallist_next(const Obj_Entry *obj) 2020 { 2021 2022 for (;;) { 2023 obj = TAILQ_NEXT(obj, next); 2024 if (obj == NULL) 2025 return (NULL); 2026 if (!obj->marker) 2027 return (__DECONST(Obj_Entry *, obj)); 2028 } 2029 } 2030 2031 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2032 static void 2033 hold_object(Obj_Entry *obj) 2034 { 2035 2036 obj->holdcount++; 2037 } 2038 2039 static void 2040 unhold_object(Obj_Entry *obj) 2041 { 2042 2043 assert(obj->holdcount > 0); 2044 if (--obj->holdcount == 0 && obj->unholdfree) 2045 release_object(obj); 2046 } 2047 2048 static void 2049 process_z(Obj_Entry *root) 2050 { 2051 const Objlist_Entry *elm; 2052 Obj_Entry *obj; 2053 2054 /* 2055 * Walk over object DAG and process every dependent object 2056 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2057 * to grow their own DAG. 2058 * 2059 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2060 * symlook_global() to work. 2061 * 2062 * For DF_1_NODELETE, the DAG should have its reference upped. 2063 */ 2064 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2065 obj = elm->obj; 2066 if (obj == NULL) 2067 continue; 2068 if (obj->z_nodelete && !obj->ref_nodel) { 2069 dbg("obj %s -z nodelete", obj->path); 2070 init_dag(obj); 2071 ref_dag(obj); 2072 obj->ref_nodel = true; 2073 } 2074 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2075 dbg("obj %s -z global", obj->path); 2076 objlist_push_tail(&list_global, obj); 2077 init_dag(obj); 2078 } 2079 } 2080 } 2081 /* 2082 * Initialize the dynamic linker. The argument is the address at which 2083 * the dynamic linker has been mapped into memory. The primary task of 2084 * this function is to relocate the dynamic linker. 2085 */ 2086 static void 2087 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2088 { 2089 Obj_Entry objtmp; /* Temporary rtld object */ 2090 const Elf_Ehdr *ehdr; 2091 const Elf_Dyn *dyn_rpath; 2092 const Elf_Dyn *dyn_soname; 2093 const Elf_Dyn *dyn_runpath; 2094 2095 #ifdef RTLD_INIT_PAGESIZES_EARLY 2096 /* The page size is required by the dynamic memory allocator. */ 2097 init_pagesizes(aux_info); 2098 #endif 2099 2100 /* 2101 * Conjure up an Obj_Entry structure for the dynamic linker. 2102 * 2103 * The "path" member can't be initialized yet because string constants 2104 * cannot yet be accessed. Below we will set it correctly. 2105 */ 2106 memset(&objtmp, 0, sizeof(objtmp)); 2107 objtmp.path = NULL; 2108 objtmp.rtld = true; 2109 objtmp.mapbase = mapbase; 2110 #ifdef PIC 2111 objtmp.relocbase = mapbase; 2112 #endif 2113 2114 objtmp.dynamic = rtld_dynamic(&objtmp); 2115 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2116 assert(objtmp.needed == NULL); 2117 #if !defined(__mips__) 2118 /* MIPS has a bogus DT_TEXTREL. */ 2119 assert(!objtmp.textrel); 2120 #endif 2121 /* 2122 * Temporarily put the dynamic linker entry into the object list, so 2123 * that symbols can be found. 2124 */ 2125 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2126 2127 ehdr = (Elf_Ehdr *)mapbase; 2128 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2129 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2130 2131 /* Initialize the object list. */ 2132 TAILQ_INIT(&obj_list); 2133 2134 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2135 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2136 2137 #ifndef RTLD_INIT_PAGESIZES_EARLY 2138 /* The page size is required by the dynamic memory allocator. */ 2139 init_pagesizes(aux_info); 2140 #endif 2141 2142 if (aux_info[AT_OSRELDATE] != NULL) 2143 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2144 2145 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2146 2147 /* Replace the path with a dynamically allocated copy. */ 2148 obj_rtld.path = xstrdup(ld_path_rtld); 2149 2150 r_debug.r_brk = r_debug_state; 2151 r_debug.r_state = RT_CONSISTENT; 2152 } 2153 2154 /* 2155 * Retrieve the array of supported page sizes. The kernel provides the page 2156 * sizes in increasing order. 2157 */ 2158 static void 2159 init_pagesizes(Elf_Auxinfo **aux_info) 2160 { 2161 static size_t psa[MAXPAGESIZES]; 2162 int mib[2]; 2163 size_t len, size; 2164 2165 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2166 NULL) { 2167 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2168 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2169 } else { 2170 len = 2; 2171 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2172 size = sizeof(psa); 2173 else { 2174 /* As a fallback, retrieve the base page size. */ 2175 size = sizeof(psa[0]); 2176 if (aux_info[AT_PAGESZ] != NULL) { 2177 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2178 goto psa_filled; 2179 } else { 2180 mib[0] = CTL_HW; 2181 mib[1] = HW_PAGESIZE; 2182 len = 2; 2183 } 2184 } 2185 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2186 _rtld_error("sysctl for hw.pagesize(s) failed"); 2187 rtld_die(); 2188 } 2189 psa_filled: 2190 pagesizes = psa; 2191 } 2192 npagesizes = size / sizeof(pagesizes[0]); 2193 /* Discard any invalid entries at the end of the array. */ 2194 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2195 npagesizes--; 2196 } 2197 2198 /* 2199 * Add the init functions from a needed object list (and its recursive 2200 * needed objects) to "list". This is not used directly; it is a helper 2201 * function for initlist_add_objects(). The write lock must be held 2202 * when this function is called. 2203 */ 2204 static void 2205 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2206 { 2207 /* Recursively process the successor needed objects. */ 2208 if (needed->next != NULL) 2209 initlist_add_neededs(needed->next, list); 2210 2211 /* Process the current needed object. */ 2212 if (needed->obj != NULL) 2213 initlist_add_objects(needed->obj, needed->obj, list); 2214 } 2215 2216 /* 2217 * Scan all of the DAGs rooted in the range of objects from "obj" to 2218 * "tail" and add their init functions to "list". This recurses over 2219 * the DAGs and ensure the proper init ordering such that each object's 2220 * needed libraries are initialized before the object itself. At the 2221 * same time, this function adds the objects to the global finalization 2222 * list "list_fini" in the opposite order. The write lock must be 2223 * held when this function is called. 2224 */ 2225 static void 2226 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2227 { 2228 Obj_Entry *nobj; 2229 2230 if (obj->init_scanned || obj->init_done) 2231 return; 2232 obj->init_scanned = true; 2233 2234 /* Recursively process the successor objects. */ 2235 nobj = globallist_next(obj); 2236 if (nobj != NULL && obj != tail) 2237 initlist_add_objects(nobj, tail, list); 2238 2239 /* Recursively process the needed objects. */ 2240 if (obj->needed != NULL) 2241 initlist_add_neededs(obj->needed, list); 2242 if (obj->needed_filtees != NULL) 2243 initlist_add_neededs(obj->needed_filtees, list); 2244 if (obj->needed_aux_filtees != NULL) 2245 initlist_add_neededs(obj->needed_aux_filtees, list); 2246 2247 /* Add the object to the init list. */ 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 void (*reg)(void (*)(void)); 2665 int index; 2666 2667 /* 2668 * Clean init_scanned flag so that objects can be rechecked and 2669 * possibly initialized earlier if any of vectors called below 2670 * cause the change by using dlopen. 2671 */ 2672 TAILQ_FOREACH(obj, &obj_list, next) { 2673 if (obj->marker) 2674 continue; 2675 obj->init_scanned = false; 2676 } 2677 2678 /* 2679 * Preserve the current error message since an init function might 2680 * call into the dynamic linker and overwrite it. 2681 */ 2682 saved_msg = errmsg_save(); 2683 STAILQ_FOREACH(elm, list, link) { 2684 if (elm->obj->init_done) /* Initialized early. */ 2685 continue; 2686 /* 2687 * Race: other thread might try to use this object before current 2688 * one completes the initialization. Not much can be done here 2689 * without better locking. 2690 */ 2691 elm->obj->init_done = true; 2692 hold_object(elm->obj); 2693 reg = NULL; 2694 if (elm->obj == obj_main && obj_main->crt_no_init) { 2695 reg = (void (*)(void (*)(void)))get_program_var_addr( 2696 "__libc_atexit", lockstate); 2697 } 2698 lock_release(rtld_bind_lock, lockstate); 2699 if (reg != NULL) { 2700 reg(rtld_exit); 2701 rtld_exit_ptr = rtld_nop_exit; 2702 } 2703 2704 /* 2705 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2706 * When this happens, DT_INIT is processed first. 2707 */ 2708 if (elm->obj->init != (Elf_Addr)NULL) { 2709 dbg("calling init function for %s at %p", elm->obj->path, 2710 (void *)elm->obj->init); 2711 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2712 0, 0, elm->obj->path); 2713 call_initfini_pointer(elm->obj, elm->obj->init); 2714 } 2715 init_addr = (Elf_Addr *)elm->obj->init_array; 2716 if (init_addr != NULL) { 2717 for (index = 0; index < elm->obj->init_array_num; index++) { 2718 if (init_addr[index] != 0 && init_addr[index] != 1) { 2719 dbg("calling init function for %s at %p", elm->obj->path, 2720 (void *)init_addr[index]); 2721 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2722 (void *)init_addr[index], 0, 0, elm->obj->path); 2723 call_init_pointer(elm->obj, init_addr[index]); 2724 } 2725 } 2726 } 2727 wlock_acquire(rtld_bind_lock, lockstate); 2728 unhold_object(elm->obj); 2729 } 2730 errmsg_restore(saved_msg); 2731 } 2732 2733 static void 2734 objlist_clear(Objlist *list) 2735 { 2736 Objlist_Entry *elm; 2737 2738 while (!STAILQ_EMPTY(list)) { 2739 elm = STAILQ_FIRST(list); 2740 STAILQ_REMOVE_HEAD(list, link); 2741 free(elm); 2742 } 2743 } 2744 2745 static Objlist_Entry * 2746 objlist_find(Objlist *list, const Obj_Entry *obj) 2747 { 2748 Objlist_Entry *elm; 2749 2750 STAILQ_FOREACH(elm, list, link) 2751 if (elm->obj == obj) 2752 return elm; 2753 return NULL; 2754 } 2755 2756 static void 2757 objlist_init(Objlist *list) 2758 { 2759 STAILQ_INIT(list); 2760 } 2761 2762 static void 2763 objlist_push_head(Objlist *list, Obj_Entry *obj) 2764 { 2765 Objlist_Entry *elm; 2766 2767 elm = NEW(Objlist_Entry); 2768 elm->obj = obj; 2769 STAILQ_INSERT_HEAD(list, elm, link); 2770 } 2771 2772 static void 2773 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2774 { 2775 Objlist_Entry *elm; 2776 2777 elm = NEW(Objlist_Entry); 2778 elm->obj = obj; 2779 STAILQ_INSERT_TAIL(list, elm, link); 2780 } 2781 2782 static void 2783 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2784 { 2785 Objlist_Entry *elm, *listelm; 2786 2787 STAILQ_FOREACH(listelm, list, link) { 2788 if (listelm->obj == listobj) 2789 break; 2790 } 2791 elm = NEW(Objlist_Entry); 2792 elm->obj = obj; 2793 if (listelm != NULL) 2794 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2795 else 2796 STAILQ_INSERT_TAIL(list, elm, link); 2797 } 2798 2799 static void 2800 objlist_remove(Objlist *list, Obj_Entry *obj) 2801 { 2802 Objlist_Entry *elm; 2803 2804 if ((elm = objlist_find(list, obj)) != NULL) { 2805 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2806 free(elm); 2807 } 2808 } 2809 2810 /* 2811 * Relocate dag rooted in the specified object. 2812 * Returns 0 on success, or -1 on failure. 2813 */ 2814 2815 static int 2816 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2817 int flags, RtldLockState *lockstate) 2818 { 2819 Objlist_Entry *elm; 2820 int error; 2821 2822 error = 0; 2823 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2824 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2825 lockstate); 2826 if (error == -1) 2827 break; 2828 } 2829 return (error); 2830 } 2831 2832 /* 2833 * Prepare for, or clean after, relocating an object marked with 2834 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 2835 * segments are remapped read-write. After relocations are done, the 2836 * segment's permissions are returned back to the modes specified in 2837 * the phdrs. If any relocation happened, or always for wired 2838 * program, COW is triggered. 2839 */ 2840 static int 2841 reloc_textrel_prot(Obj_Entry *obj, bool before) 2842 { 2843 const Elf_Phdr *ph; 2844 void *base; 2845 size_t l, sz; 2846 int prot; 2847 2848 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 2849 l--, ph++) { 2850 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 2851 continue; 2852 base = obj->relocbase + trunc_page(ph->p_vaddr); 2853 sz = round_page(ph->p_vaddr + ph->p_filesz) - 2854 trunc_page(ph->p_vaddr); 2855 prot = convert_prot(ph->p_flags) | (before ? PROT_WRITE : 0); 2856 if (mprotect(base, sz, prot) == -1) { 2857 _rtld_error("%s: Cannot write-%sable text segment: %s", 2858 obj->path, before ? "en" : "dis", 2859 rtld_strerror(errno)); 2860 return (-1); 2861 } 2862 } 2863 return (0); 2864 } 2865 2866 /* 2867 * Relocate single object. 2868 * Returns 0 on success, or -1 on failure. 2869 */ 2870 static int 2871 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2872 int flags, RtldLockState *lockstate) 2873 { 2874 2875 if (obj->relocated) 2876 return (0); 2877 obj->relocated = true; 2878 if (obj != rtldobj) 2879 dbg("relocating \"%s\"", obj->path); 2880 2881 if (obj->symtab == NULL || obj->strtab == NULL || 2882 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2883 _rtld_error("%s: Shared object has no run-time symbol table", 2884 obj->path); 2885 return (-1); 2886 } 2887 2888 /* There are relocations to the write-protected text segment. */ 2889 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 2890 return (-1); 2891 2892 /* Process the non-PLT non-IFUNC relocations. */ 2893 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2894 return (-1); 2895 2896 /* Re-protected the text segment. */ 2897 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 2898 return (-1); 2899 2900 /* Set the special PLT or GOT entries. */ 2901 init_pltgot(obj); 2902 2903 /* Process the PLT relocations. */ 2904 if (reloc_plt(obj, flags, lockstate) == -1) 2905 return (-1); 2906 /* Relocate the jump slots if we are doing immediate binding. */ 2907 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 2908 lockstate) == -1) 2909 return (-1); 2910 2911 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 2912 return (-1); 2913 2914 /* 2915 * Set up the magic number and version in the Obj_Entry. These 2916 * were checked in the crt1.o from the original ElfKit, so we 2917 * set them for backward compatibility. 2918 */ 2919 obj->magic = RTLD_MAGIC; 2920 obj->version = RTLD_VERSION; 2921 2922 return (0); 2923 } 2924 2925 /* 2926 * Relocate newly-loaded shared objects. The argument is a pointer to 2927 * the Obj_Entry for the first such object. All objects from the first 2928 * to the end of the list of objects are relocated. Returns 0 on success, 2929 * or -1 on failure. 2930 */ 2931 static int 2932 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2933 int flags, RtldLockState *lockstate) 2934 { 2935 Obj_Entry *obj; 2936 int error; 2937 2938 for (error = 0, obj = first; obj != NULL; 2939 obj = TAILQ_NEXT(obj, next)) { 2940 if (obj->marker) 2941 continue; 2942 error = relocate_object(obj, bind_now, rtldobj, flags, 2943 lockstate); 2944 if (error == -1) 2945 break; 2946 } 2947 return (error); 2948 } 2949 2950 /* 2951 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2952 * referencing STT_GNU_IFUNC symbols is postponed till the other 2953 * relocations are done. The indirect functions specified as 2954 * ifunc are allowed to call other symbols, so we need to have 2955 * objects relocated before asking for resolution from indirects. 2956 * 2957 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2958 * instead of the usual lazy handling of PLT slots. It is 2959 * consistent with how GNU does it. 2960 */ 2961 static int 2962 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2963 RtldLockState *lockstate) 2964 { 2965 2966 if (obj->ifuncs_resolved) 2967 return (0); 2968 obj->ifuncs_resolved = true; 2969 if (!obj->irelative && !((obj->bind_now || bind_now) && obj->gnu_ifunc)) 2970 return (0); 2971 if (obj_disable_relro(obj) == -1 || 2972 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 2973 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2974 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 2975 obj_enforce_relro(obj) == -1) 2976 return (-1); 2977 return (0); 2978 } 2979 2980 static int 2981 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2982 RtldLockState *lockstate) 2983 { 2984 Objlist_Entry *elm; 2985 Obj_Entry *obj; 2986 2987 STAILQ_FOREACH(elm, list, link) { 2988 obj = elm->obj; 2989 if (obj->marker) 2990 continue; 2991 if (resolve_object_ifunc(obj, bind_now, flags, 2992 lockstate) == -1) 2993 return (-1); 2994 } 2995 return (0); 2996 } 2997 2998 /* 2999 * Cleanup procedure. It will be called (by the atexit mechanism) just 3000 * before the process exits. 3001 */ 3002 static void 3003 rtld_exit(void) 3004 { 3005 RtldLockState lockstate; 3006 3007 wlock_acquire(rtld_bind_lock, &lockstate); 3008 dbg("rtld_exit()"); 3009 objlist_call_fini(&list_fini, NULL, &lockstate); 3010 /* No need to remove the items from the list, since we are exiting. */ 3011 if (!libmap_disable) 3012 lm_fini(); 3013 lock_release(rtld_bind_lock, &lockstate); 3014 } 3015 3016 static void 3017 rtld_nop_exit(void) 3018 { 3019 } 3020 3021 /* 3022 * Iterate over a search path, translate each element, and invoke the 3023 * callback on the result. 3024 */ 3025 static void * 3026 path_enumerate(const char *path, path_enum_proc callback, 3027 const char *refobj_path, void *arg) 3028 { 3029 const char *trans; 3030 if (path == NULL) 3031 return (NULL); 3032 3033 path += strspn(path, ":;"); 3034 while (*path != '\0') { 3035 size_t len; 3036 char *res; 3037 3038 len = strcspn(path, ":;"); 3039 trans = lm_findn(refobj_path, path, len); 3040 if (trans) 3041 res = callback(trans, strlen(trans), arg); 3042 else 3043 res = callback(path, len, arg); 3044 3045 if (res != NULL) 3046 return (res); 3047 3048 path += len; 3049 path += strspn(path, ":;"); 3050 } 3051 3052 return (NULL); 3053 } 3054 3055 struct try_library_args { 3056 const char *name; 3057 size_t namelen; 3058 char *buffer; 3059 size_t buflen; 3060 int fd; 3061 }; 3062 3063 static void * 3064 try_library_path(const char *dir, size_t dirlen, void *param) 3065 { 3066 struct try_library_args *arg; 3067 int fd; 3068 3069 arg = param; 3070 if (*dir == '/' || trust) { 3071 char *pathname; 3072 3073 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3074 return (NULL); 3075 3076 pathname = arg->buffer; 3077 strncpy(pathname, dir, dirlen); 3078 pathname[dirlen] = '/'; 3079 strcpy(pathname + dirlen + 1, arg->name); 3080 3081 dbg(" Trying \"%s\"", pathname); 3082 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3083 if (fd >= 0) { 3084 dbg(" Opened \"%s\", fd %d", pathname, fd); 3085 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3086 strcpy(pathname, arg->buffer); 3087 arg->fd = fd; 3088 return (pathname); 3089 } else { 3090 dbg(" Failed to open \"%s\": %s", 3091 pathname, rtld_strerror(errno)); 3092 } 3093 } 3094 return (NULL); 3095 } 3096 3097 static char * 3098 search_library_path(const char *name, const char *path, 3099 const char *refobj_path, int *fdp) 3100 { 3101 char *p; 3102 struct try_library_args arg; 3103 3104 if (path == NULL) 3105 return NULL; 3106 3107 arg.name = name; 3108 arg.namelen = strlen(name); 3109 arg.buffer = xmalloc(PATH_MAX); 3110 arg.buflen = PATH_MAX; 3111 arg.fd = -1; 3112 3113 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3114 *fdp = arg.fd; 3115 3116 free(arg.buffer); 3117 3118 return (p); 3119 } 3120 3121 3122 /* 3123 * Finds the library with the given name using the directory descriptors 3124 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3125 * 3126 * Returns a freshly-opened close-on-exec file descriptor for the library, 3127 * or -1 if the library cannot be found. 3128 */ 3129 static char * 3130 search_library_pathfds(const char *name, const char *path, int *fdp) 3131 { 3132 char *envcopy, *fdstr, *found, *last_token; 3133 size_t len; 3134 int dirfd, fd; 3135 3136 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3137 3138 /* Don't load from user-specified libdirs into setuid binaries. */ 3139 if (!trust) 3140 return (NULL); 3141 3142 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3143 if (path == NULL) 3144 return (NULL); 3145 3146 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3147 if (name[0] == '/') { 3148 dbg("Absolute path (%s) passed to %s", name, __func__); 3149 return (NULL); 3150 } 3151 3152 /* 3153 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3154 * copy of the path, as strtok_r rewrites separator tokens 3155 * with '\0'. 3156 */ 3157 found = NULL; 3158 envcopy = xstrdup(path); 3159 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3160 fdstr = strtok_r(NULL, ":", &last_token)) { 3161 dirfd = parse_integer(fdstr); 3162 if (dirfd < 0) { 3163 _rtld_error("failed to parse directory FD: '%s'", 3164 fdstr); 3165 break; 3166 } 3167 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3168 if (fd >= 0) { 3169 *fdp = fd; 3170 len = strlen(fdstr) + strlen(name) + 3; 3171 found = xmalloc(len); 3172 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3173 _rtld_error("error generating '%d/%s'", 3174 dirfd, name); 3175 rtld_die(); 3176 } 3177 dbg("open('%s') => %d", found, fd); 3178 break; 3179 } 3180 } 3181 free(envcopy); 3182 3183 return (found); 3184 } 3185 3186 3187 int 3188 dlclose(void *handle) 3189 { 3190 RtldLockState lockstate; 3191 int error; 3192 3193 wlock_acquire(rtld_bind_lock, &lockstate); 3194 error = dlclose_locked(handle, &lockstate); 3195 lock_release(rtld_bind_lock, &lockstate); 3196 return (error); 3197 } 3198 3199 static int 3200 dlclose_locked(void *handle, RtldLockState *lockstate) 3201 { 3202 Obj_Entry *root; 3203 3204 root = dlcheck(handle); 3205 if (root == NULL) 3206 return -1; 3207 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3208 root->path); 3209 3210 /* Unreference the object and its dependencies. */ 3211 root->dl_refcount--; 3212 3213 if (root->refcount == 1) { 3214 /* 3215 * The object will be no longer referenced, so we must unload it. 3216 * First, call the fini functions. 3217 */ 3218 objlist_call_fini(&list_fini, root, lockstate); 3219 3220 unref_dag(root); 3221 3222 /* Finish cleaning up the newly-unreferenced objects. */ 3223 GDB_STATE(RT_DELETE,&root->linkmap); 3224 unload_object(root, lockstate); 3225 GDB_STATE(RT_CONSISTENT,NULL); 3226 } else 3227 unref_dag(root); 3228 3229 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3230 return 0; 3231 } 3232 3233 char * 3234 dlerror(void) 3235 { 3236 char *msg = error_message; 3237 error_message = NULL; 3238 return msg; 3239 } 3240 3241 /* 3242 * This function is deprecated and has no effect. 3243 */ 3244 void 3245 dllockinit(void *context, 3246 void *(*_lock_create)(void *context) __unused, 3247 void (*_rlock_acquire)(void *lock) __unused, 3248 void (*_wlock_acquire)(void *lock) __unused, 3249 void (*_lock_release)(void *lock) __unused, 3250 void (*_lock_destroy)(void *lock) __unused, 3251 void (*context_destroy)(void *context)) 3252 { 3253 static void *cur_context; 3254 static void (*cur_context_destroy)(void *); 3255 3256 /* Just destroy the context from the previous call, if necessary. */ 3257 if (cur_context_destroy != NULL) 3258 cur_context_destroy(cur_context); 3259 cur_context = context; 3260 cur_context_destroy = context_destroy; 3261 } 3262 3263 void * 3264 dlopen(const char *name, int mode) 3265 { 3266 3267 return (rtld_dlopen(name, -1, mode)); 3268 } 3269 3270 void * 3271 fdlopen(int fd, int mode) 3272 { 3273 3274 return (rtld_dlopen(NULL, fd, mode)); 3275 } 3276 3277 static void * 3278 rtld_dlopen(const char *name, int fd, int mode) 3279 { 3280 RtldLockState lockstate; 3281 int lo_flags; 3282 3283 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3284 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3285 if (ld_tracing != NULL) { 3286 rlock_acquire(rtld_bind_lock, &lockstate); 3287 if (sigsetjmp(lockstate.env, 0) != 0) 3288 lock_upgrade(rtld_bind_lock, &lockstate); 3289 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3290 lock_release(rtld_bind_lock, &lockstate); 3291 } 3292 lo_flags = RTLD_LO_DLOPEN; 3293 if (mode & RTLD_NODELETE) 3294 lo_flags |= RTLD_LO_NODELETE; 3295 if (mode & RTLD_NOLOAD) 3296 lo_flags |= RTLD_LO_NOLOAD; 3297 if (ld_tracing != NULL) 3298 lo_flags |= RTLD_LO_TRACE; 3299 3300 return (dlopen_object(name, fd, obj_main, lo_flags, 3301 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3302 } 3303 3304 static void 3305 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3306 { 3307 3308 obj->dl_refcount--; 3309 unref_dag(obj); 3310 if (obj->refcount == 0) 3311 unload_object(obj, lockstate); 3312 } 3313 3314 static Obj_Entry * 3315 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3316 int mode, RtldLockState *lockstate) 3317 { 3318 Obj_Entry *old_obj_tail; 3319 Obj_Entry *obj; 3320 Objlist initlist; 3321 RtldLockState mlockstate; 3322 int result; 3323 3324 objlist_init(&initlist); 3325 3326 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3327 wlock_acquire(rtld_bind_lock, &mlockstate); 3328 lockstate = &mlockstate; 3329 } 3330 GDB_STATE(RT_ADD,NULL); 3331 3332 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3333 obj = NULL; 3334 if (name == NULL && fd == -1) { 3335 obj = obj_main; 3336 obj->refcount++; 3337 } else { 3338 obj = load_object(name, fd, refobj, lo_flags); 3339 } 3340 3341 if (obj) { 3342 obj->dl_refcount++; 3343 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3344 objlist_push_tail(&list_global, obj); 3345 if (globallist_next(old_obj_tail) != NULL) { 3346 /* We loaded something new. */ 3347 assert(globallist_next(old_obj_tail) == obj); 3348 result = 0; 3349 if ((lo_flags & RTLD_LO_EARLY) == 0 && obj->static_tls && 3350 !allocate_tls_offset(obj)) { 3351 _rtld_error("%s: No space available " 3352 "for static Thread Local Storage", obj->path); 3353 result = -1; 3354 } 3355 if (result != -1) 3356 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3357 RTLD_LO_EARLY)); 3358 init_dag(obj); 3359 ref_dag(obj); 3360 if (result != -1) 3361 result = rtld_verify_versions(&obj->dagmembers); 3362 if (result != -1 && ld_tracing) 3363 goto trace; 3364 if (result == -1 || relocate_object_dag(obj, 3365 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3366 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3367 lockstate) == -1) { 3368 dlopen_cleanup(obj, lockstate); 3369 obj = NULL; 3370 } else if (lo_flags & RTLD_LO_EARLY) { 3371 /* 3372 * Do not call the init functions for early loaded 3373 * filtees. The image is still not initialized enough 3374 * for them to work. 3375 * 3376 * Our object is found by the global object list and 3377 * will be ordered among all init calls done right 3378 * before transferring control to main. 3379 */ 3380 } else { 3381 /* Make list of init functions to call. */ 3382 initlist_add_objects(obj, obj, &initlist); 3383 } 3384 /* 3385 * Process all no_delete or global objects here, given 3386 * them own DAGs to prevent their dependencies from being 3387 * unloaded. This has to be done after we have loaded all 3388 * of the dependencies, so that we do not miss any. 3389 */ 3390 if (obj != NULL) 3391 process_z(obj); 3392 } else { 3393 /* 3394 * Bump the reference counts for objects on this DAG. If 3395 * this is the first dlopen() call for the object that was 3396 * already loaded as a dependency, initialize the dag 3397 * starting at it. 3398 */ 3399 init_dag(obj); 3400 ref_dag(obj); 3401 3402 if ((lo_flags & RTLD_LO_TRACE) != 0) 3403 goto trace; 3404 } 3405 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3406 obj->z_nodelete) && !obj->ref_nodel) { 3407 dbg("obj %s nodelete", obj->path); 3408 ref_dag(obj); 3409 obj->z_nodelete = obj->ref_nodel = true; 3410 } 3411 } 3412 3413 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3414 name); 3415 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3416 3417 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3418 map_stacks_exec(lockstate); 3419 if (obj != NULL) 3420 distribute_static_tls(&initlist, lockstate); 3421 } 3422 3423 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3424 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3425 lockstate) == -1) { 3426 objlist_clear(&initlist); 3427 dlopen_cleanup(obj, lockstate); 3428 if (lockstate == &mlockstate) 3429 lock_release(rtld_bind_lock, lockstate); 3430 return (NULL); 3431 } 3432 3433 if (!(lo_flags & RTLD_LO_EARLY)) { 3434 /* Call the init functions. */ 3435 objlist_call_init(&initlist, lockstate); 3436 } 3437 objlist_clear(&initlist); 3438 if (lockstate == &mlockstate) 3439 lock_release(rtld_bind_lock, lockstate); 3440 return obj; 3441 trace: 3442 trace_loaded_objects(obj); 3443 if (lockstate == &mlockstate) 3444 lock_release(rtld_bind_lock, lockstate); 3445 exit(0); 3446 } 3447 3448 static void * 3449 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3450 int flags) 3451 { 3452 DoneList donelist; 3453 const Obj_Entry *obj, *defobj; 3454 const Elf_Sym *def; 3455 SymLook req; 3456 RtldLockState lockstate; 3457 tls_index ti; 3458 void *sym; 3459 int res; 3460 3461 def = NULL; 3462 defobj = NULL; 3463 symlook_init(&req, name); 3464 req.ventry = ve; 3465 req.flags = flags | SYMLOOK_IN_PLT; 3466 req.lockstate = &lockstate; 3467 3468 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3469 rlock_acquire(rtld_bind_lock, &lockstate); 3470 if (sigsetjmp(lockstate.env, 0) != 0) 3471 lock_upgrade(rtld_bind_lock, &lockstate); 3472 if (handle == NULL || handle == RTLD_NEXT || 3473 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3474 3475 if ((obj = obj_from_addr(retaddr)) == NULL) { 3476 _rtld_error("Cannot determine caller's shared object"); 3477 lock_release(rtld_bind_lock, &lockstate); 3478 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3479 return NULL; 3480 } 3481 if (handle == NULL) { /* Just the caller's shared object. */ 3482 res = symlook_obj(&req, obj); 3483 if (res == 0) { 3484 def = req.sym_out; 3485 defobj = req.defobj_out; 3486 } 3487 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3488 handle == RTLD_SELF) { /* ... caller included */ 3489 if (handle == RTLD_NEXT) 3490 obj = globallist_next(obj); 3491 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3492 if (obj->marker) 3493 continue; 3494 res = symlook_obj(&req, obj); 3495 if (res == 0) { 3496 if (def == NULL || 3497 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3498 def = req.sym_out; 3499 defobj = req.defobj_out; 3500 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3501 break; 3502 } 3503 } 3504 } 3505 /* 3506 * Search the dynamic linker itself, and possibly resolve the 3507 * symbol from there. This is how the application links to 3508 * dynamic linker services such as dlopen. 3509 */ 3510 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3511 res = symlook_obj(&req, &obj_rtld); 3512 if (res == 0) { 3513 def = req.sym_out; 3514 defobj = req.defobj_out; 3515 } 3516 } 3517 } else { 3518 assert(handle == RTLD_DEFAULT); 3519 res = symlook_default(&req, obj); 3520 if (res == 0) { 3521 defobj = req.defobj_out; 3522 def = req.sym_out; 3523 } 3524 } 3525 } else { 3526 if ((obj = dlcheck(handle)) == NULL) { 3527 lock_release(rtld_bind_lock, &lockstate); 3528 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3529 return NULL; 3530 } 3531 3532 donelist_init(&donelist); 3533 if (obj->mainprog) { 3534 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3535 res = symlook_global(&req, &donelist); 3536 if (res == 0) { 3537 def = req.sym_out; 3538 defobj = req.defobj_out; 3539 } 3540 /* 3541 * Search the dynamic linker itself, and possibly resolve the 3542 * symbol from there. This is how the application links to 3543 * dynamic linker services such as dlopen. 3544 */ 3545 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3546 res = symlook_obj(&req, &obj_rtld); 3547 if (res == 0) { 3548 def = req.sym_out; 3549 defobj = req.defobj_out; 3550 } 3551 } 3552 } 3553 else { 3554 /* Search the whole DAG rooted at the given object. */ 3555 res = symlook_list(&req, &obj->dagmembers, &donelist); 3556 if (res == 0) { 3557 def = req.sym_out; 3558 defobj = req.defobj_out; 3559 } 3560 } 3561 } 3562 3563 if (def != NULL) { 3564 lock_release(rtld_bind_lock, &lockstate); 3565 3566 /* 3567 * The value required by the caller is derived from the value 3568 * of the symbol. this is simply the relocated value of the 3569 * symbol. 3570 */ 3571 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3572 sym = make_function_pointer(def, defobj); 3573 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3574 sym = rtld_resolve_ifunc(defobj, def); 3575 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3576 ti.ti_module = defobj->tlsindex; 3577 ti.ti_offset = def->st_value; 3578 sym = __tls_get_addr(&ti); 3579 } else 3580 sym = defobj->relocbase + def->st_value; 3581 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3582 return (sym); 3583 } 3584 3585 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3586 ve != NULL ? ve->name : ""); 3587 lock_release(rtld_bind_lock, &lockstate); 3588 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3589 return NULL; 3590 } 3591 3592 void * 3593 dlsym(void *handle, const char *name) 3594 { 3595 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3596 SYMLOOK_DLSYM); 3597 } 3598 3599 dlfunc_t 3600 dlfunc(void *handle, const char *name) 3601 { 3602 union { 3603 void *d; 3604 dlfunc_t f; 3605 } rv; 3606 3607 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3608 SYMLOOK_DLSYM); 3609 return (rv.f); 3610 } 3611 3612 void * 3613 dlvsym(void *handle, const char *name, const char *version) 3614 { 3615 Ver_Entry ventry; 3616 3617 ventry.name = version; 3618 ventry.file = NULL; 3619 ventry.hash = elf_hash(version); 3620 ventry.flags= 0; 3621 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3622 SYMLOOK_DLSYM); 3623 } 3624 3625 int 3626 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3627 { 3628 const Obj_Entry *obj; 3629 RtldLockState lockstate; 3630 3631 rlock_acquire(rtld_bind_lock, &lockstate); 3632 obj = obj_from_addr(addr); 3633 if (obj == NULL) { 3634 _rtld_error("No shared object contains address"); 3635 lock_release(rtld_bind_lock, &lockstate); 3636 return (0); 3637 } 3638 rtld_fill_dl_phdr_info(obj, phdr_info); 3639 lock_release(rtld_bind_lock, &lockstate); 3640 return (1); 3641 } 3642 3643 int 3644 dladdr(const void *addr, Dl_info *info) 3645 { 3646 const Obj_Entry *obj; 3647 const Elf_Sym *def; 3648 void *symbol_addr; 3649 unsigned long symoffset; 3650 RtldLockState lockstate; 3651 3652 rlock_acquire(rtld_bind_lock, &lockstate); 3653 obj = obj_from_addr(addr); 3654 if (obj == NULL) { 3655 _rtld_error("No shared object contains address"); 3656 lock_release(rtld_bind_lock, &lockstate); 3657 return 0; 3658 } 3659 info->dli_fname = obj->path; 3660 info->dli_fbase = obj->mapbase; 3661 info->dli_saddr = (void *)0; 3662 info->dli_sname = NULL; 3663 3664 /* 3665 * Walk the symbol list looking for the symbol whose address is 3666 * closest to the address sent in. 3667 */ 3668 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3669 def = obj->symtab + symoffset; 3670 3671 /* 3672 * For skip the symbol if st_shndx is either SHN_UNDEF or 3673 * SHN_COMMON. 3674 */ 3675 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3676 continue; 3677 3678 /* 3679 * If the symbol is greater than the specified address, or if it 3680 * is further away from addr than the current nearest symbol, 3681 * then reject it. 3682 */ 3683 symbol_addr = obj->relocbase + def->st_value; 3684 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3685 continue; 3686 3687 /* Update our idea of the nearest symbol. */ 3688 info->dli_sname = obj->strtab + def->st_name; 3689 info->dli_saddr = symbol_addr; 3690 3691 /* Exact match? */ 3692 if (info->dli_saddr == addr) 3693 break; 3694 } 3695 lock_release(rtld_bind_lock, &lockstate); 3696 return 1; 3697 } 3698 3699 int 3700 dlinfo(void *handle, int request, void *p) 3701 { 3702 const Obj_Entry *obj; 3703 RtldLockState lockstate; 3704 int error; 3705 3706 rlock_acquire(rtld_bind_lock, &lockstate); 3707 3708 if (handle == NULL || handle == RTLD_SELF) { 3709 void *retaddr; 3710 3711 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3712 if ((obj = obj_from_addr(retaddr)) == NULL) 3713 _rtld_error("Cannot determine caller's shared object"); 3714 } else 3715 obj = dlcheck(handle); 3716 3717 if (obj == NULL) { 3718 lock_release(rtld_bind_lock, &lockstate); 3719 return (-1); 3720 } 3721 3722 error = 0; 3723 switch (request) { 3724 case RTLD_DI_LINKMAP: 3725 *((struct link_map const **)p) = &obj->linkmap; 3726 break; 3727 case RTLD_DI_ORIGIN: 3728 error = rtld_dirname(obj->path, p); 3729 break; 3730 3731 case RTLD_DI_SERINFOSIZE: 3732 case RTLD_DI_SERINFO: 3733 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3734 break; 3735 3736 default: 3737 _rtld_error("Invalid request %d passed to dlinfo()", request); 3738 error = -1; 3739 } 3740 3741 lock_release(rtld_bind_lock, &lockstate); 3742 3743 return (error); 3744 } 3745 3746 static void 3747 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3748 { 3749 3750 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3751 phdr_info->dlpi_name = obj->path; 3752 phdr_info->dlpi_phdr = obj->phdr; 3753 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3754 phdr_info->dlpi_tls_modid = obj->tlsindex; 3755 phdr_info->dlpi_tls_data = obj->tlsinit; 3756 phdr_info->dlpi_adds = obj_loads; 3757 phdr_info->dlpi_subs = obj_loads - obj_count; 3758 } 3759 3760 int 3761 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3762 { 3763 struct dl_phdr_info phdr_info; 3764 Obj_Entry *obj, marker; 3765 RtldLockState bind_lockstate, phdr_lockstate; 3766 int error; 3767 3768 init_marker(&marker); 3769 error = 0; 3770 3771 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3772 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3773 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3774 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3775 rtld_fill_dl_phdr_info(obj, &phdr_info); 3776 hold_object(obj); 3777 lock_release(rtld_bind_lock, &bind_lockstate); 3778 3779 error = callback(&phdr_info, sizeof phdr_info, param); 3780 3781 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3782 unhold_object(obj); 3783 obj = globallist_next(&marker); 3784 TAILQ_REMOVE(&obj_list, &marker, next); 3785 if (error != 0) { 3786 lock_release(rtld_bind_lock, &bind_lockstate); 3787 lock_release(rtld_phdr_lock, &phdr_lockstate); 3788 return (error); 3789 } 3790 } 3791 3792 if (error == 0) { 3793 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3794 lock_release(rtld_bind_lock, &bind_lockstate); 3795 error = callback(&phdr_info, sizeof(phdr_info), param); 3796 } 3797 lock_release(rtld_phdr_lock, &phdr_lockstate); 3798 return (error); 3799 } 3800 3801 static void * 3802 fill_search_info(const char *dir, size_t dirlen, void *param) 3803 { 3804 struct fill_search_info_args *arg; 3805 3806 arg = param; 3807 3808 if (arg->request == RTLD_DI_SERINFOSIZE) { 3809 arg->serinfo->dls_cnt ++; 3810 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3811 } else { 3812 struct dl_serpath *s_entry; 3813 3814 s_entry = arg->serpath; 3815 s_entry->dls_name = arg->strspace; 3816 s_entry->dls_flags = arg->flags; 3817 3818 strncpy(arg->strspace, dir, dirlen); 3819 arg->strspace[dirlen] = '\0'; 3820 3821 arg->strspace += dirlen + 1; 3822 arg->serpath++; 3823 } 3824 3825 return (NULL); 3826 } 3827 3828 static int 3829 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3830 { 3831 struct dl_serinfo _info; 3832 struct fill_search_info_args args; 3833 3834 args.request = RTLD_DI_SERINFOSIZE; 3835 args.serinfo = &_info; 3836 3837 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3838 _info.dls_cnt = 0; 3839 3840 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 3841 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 3842 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 3843 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 3844 if (!obj->z_nodeflib) 3845 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 3846 3847 3848 if (request == RTLD_DI_SERINFOSIZE) { 3849 info->dls_size = _info.dls_size; 3850 info->dls_cnt = _info.dls_cnt; 3851 return (0); 3852 } 3853 3854 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3855 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3856 return (-1); 3857 } 3858 3859 args.request = RTLD_DI_SERINFO; 3860 args.serinfo = info; 3861 args.serpath = &info->dls_serpath[0]; 3862 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3863 3864 args.flags = LA_SER_RUNPATH; 3865 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 3866 return (-1); 3867 3868 args.flags = LA_SER_LIBPATH; 3869 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 3870 return (-1); 3871 3872 args.flags = LA_SER_RUNPATH; 3873 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 3874 return (-1); 3875 3876 args.flags = LA_SER_CONFIG; 3877 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 3878 != NULL) 3879 return (-1); 3880 3881 args.flags = LA_SER_DEFAULT; 3882 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 3883 fill_search_info, NULL, &args) != NULL) 3884 return (-1); 3885 return (0); 3886 } 3887 3888 static int 3889 rtld_dirname(const char *path, char *bname) 3890 { 3891 const char *endp; 3892 3893 /* Empty or NULL string gets treated as "." */ 3894 if (path == NULL || *path == '\0') { 3895 bname[0] = '.'; 3896 bname[1] = '\0'; 3897 return (0); 3898 } 3899 3900 /* Strip trailing slashes */ 3901 endp = path + strlen(path) - 1; 3902 while (endp > path && *endp == '/') 3903 endp--; 3904 3905 /* Find the start of the dir */ 3906 while (endp > path && *endp != '/') 3907 endp--; 3908 3909 /* Either the dir is "/" or there are no slashes */ 3910 if (endp == path) { 3911 bname[0] = *endp == '/' ? '/' : '.'; 3912 bname[1] = '\0'; 3913 return (0); 3914 } else { 3915 do { 3916 endp--; 3917 } while (endp > path && *endp == '/'); 3918 } 3919 3920 if (endp - path + 2 > PATH_MAX) 3921 { 3922 _rtld_error("Filename is too long: %s", path); 3923 return(-1); 3924 } 3925 3926 strncpy(bname, path, endp - path + 1); 3927 bname[endp - path + 1] = '\0'; 3928 return (0); 3929 } 3930 3931 static int 3932 rtld_dirname_abs(const char *path, char *base) 3933 { 3934 char *last; 3935 3936 if (realpath(path, base) == NULL) 3937 return (-1); 3938 dbg("%s -> %s", path, base); 3939 last = strrchr(base, '/'); 3940 if (last == NULL) 3941 return (-1); 3942 if (last != base) 3943 *last = '\0'; 3944 return (0); 3945 } 3946 3947 static void 3948 linkmap_add(Obj_Entry *obj) 3949 { 3950 struct link_map *l = &obj->linkmap; 3951 struct link_map *prev; 3952 3953 obj->linkmap.l_name = obj->path; 3954 obj->linkmap.l_addr = obj->mapbase; 3955 obj->linkmap.l_ld = obj->dynamic; 3956 #ifdef __mips__ 3957 /* GDB needs load offset on MIPS to use the symbols */ 3958 obj->linkmap.l_offs = obj->relocbase; 3959 #endif 3960 3961 if (r_debug.r_map == NULL) { 3962 r_debug.r_map = l; 3963 return; 3964 } 3965 3966 /* 3967 * Scan to the end of the list, but not past the entry for the 3968 * dynamic linker, which we want to keep at the very end. 3969 */ 3970 for (prev = r_debug.r_map; 3971 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3972 prev = prev->l_next) 3973 ; 3974 3975 /* Link in the new entry. */ 3976 l->l_prev = prev; 3977 l->l_next = prev->l_next; 3978 if (l->l_next != NULL) 3979 l->l_next->l_prev = l; 3980 prev->l_next = l; 3981 } 3982 3983 static void 3984 linkmap_delete(Obj_Entry *obj) 3985 { 3986 struct link_map *l = &obj->linkmap; 3987 3988 if (l->l_prev == NULL) { 3989 if ((r_debug.r_map = l->l_next) != NULL) 3990 l->l_next->l_prev = NULL; 3991 return; 3992 } 3993 3994 if ((l->l_prev->l_next = l->l_next) != NULL) 3995 l->l_next->l_prev = l->l_prev; 3996 } 3997 3998 /* 3999 * Function for the debugger to set a breakpoint on to gain control. 4000 * 4001 * The two parameters allow the debugger to easily find and determine 4002 * what the runtime loader is doing and to whom it is doing it. 4003 * 4004 * When the loadhook trap is hit (r_debug_state, set at program 4005 * initialization), the arguments can be found on the stack: 4006 * 4007 * +8 struct link_map *m 4008 * +4 struct r_debug *rd 4009 * +0 RetAddr 4010 */ 4011 void 4012 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4013 { 4014 /* 4015 * The following is a hack to force the compiler to emit calls to 4016 * this function, even when optimizing. If the function is empty, 4017 * the compiler is not obliged to emit any code for calls to it, 4018 * even when marked __noinline. However, gdb depends on those 4019 * calls being made. 4020 */ 4021 __compiler_membar(); 4022 } 4023 4024 /* 4025 * A function called after init routines have completed. This can be used to 4026 * break before a program's entry routine is called, and can be used when 4027 * main is not available in the symbol table. 4028 */ 4029 void 4030 _r_debug_postinit(struct link_map *m __unused) 4031 { 4032 4033 /* See r_debug_state(). */ 4034 __compiler_membar(); 4035 } 4036 4037 static void 4038 release_object(Obj_Entry *obj) 4039 { 4040 4041 if (obj->holdcount > 0) { 4042 obj->unholdfree = true; 4043 return; 4044 } 4045 munmap(obj->mapbase, obj->mapsize); 4046 linkmap_delete(obj); 4047 obj_free(obj); 4048 } 4049 4050 /* 4051 * Get address of the pointer variable in the main program. 4052 * Prefer non-weak symbol over the weak one. 4053 */ 4054 static const void ** 4055 get_program_var_addr(const char *name, RtldLockState *lockstate) 4056 { 4057 SymLook req; 4058 DoneList donelist; 4059 4060 symlook_init(&req, name); 4061 req.lockstate = lockstate; 4062 donelist_init(&donelist); 4063 if (symlook_global(&req, &donelist) != 0) 4064 return (NULL); 4065 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4066 return ((const void **)make_function_pointer(req.sym_out, 4067 req.defobj_out)); 4068 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4069 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4070 else 4071 return ((const void **)(req.defobj_out->relocbase + 4072 req.sym_out->st_value)); 4073 } 4074 4075 /* 4076 * Set a pointer variable in the main program to the given value. This 4077 * is used to set key variables such as "environ" before any of the 4078 * init functions are called. 4079 */ 4080 static void 4081 set_program_var(const char *name, const void *value) 4082 { 4083 const void **addr; 4084 4085 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4086 dbg("\"%s\": *%p <-- %p", name, addr, value); 4087 *addr = value; 4088 } 4089 } 4090 4091 /* 4092 * Search the global objects, including dependencies and main object, 4093 * for the given symbol. 4094 */ 4095 static int 4096 symlook_global(SymLook *req, DoneList *donelist) 4097 { 4098 SymLook req1; 4099 const Objlist_Entry *elm; 4100 int res; 4101 4102 symlook_init_from_req(&req1, req); 4103 4104 /* Search all objects loaded at program start up. */ 4105 if (req->defobj_out == NULL || 4106 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4107 res = symlook_list(&req1, &list_main, donelist); 4108 if (res == 0 && (req->defobj_out == NULL || 4109 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4110 req->sym_out = req1.sym_out; 4111 req->defobj_out = req1.defobj_out; 4112 assert(req->defobj_out != NULL); 4113 } 4114 } 4115 4116 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4117 STAILQ_FOREACH(elm, &list_global, link) { 4118 if (req->defobj_out != NULL && 4119 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4120 break; 4121 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4122 if (res == 0 && (req->defobj_out == NULL || 4123 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4124 req->sym_out = req1.sym_out; 4125 req->defobj_out = req1.defobj_out; 4126 assert(req->defobj_out != NULL); 4127 } 4128 } 4129 4130 return (req->sym_out != NULL ? 0 : ESRCH); 4131 } 4132 4133 /* 4134 * Given a symbol name in a referencing object, find the corresponding 4135 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4136 * no definition was found. Returns a pointer to the Obj_Entry of the 4137 * defining object via the reference parameter DEFOBJ_OUT. 4138 */ 4139 static int 4140 symlook_default(SymLook *req, const Obj_Entry *refobj) 4141 { 4142 DoneList donelist; 4143 const Objlist_Entry *elm; 4144 SymLook req1; 4145 int res; 4146 4147 donelist_init(&donelist); 4148 symlook_init_from_req(&req1, req); 4149 4150 /* 4151 * Look first in the referencing object if linked symbolically, 4152 * and similarly handle protected symbols. 4153 */ 4154 res = symlook_obj(&req1, refobj); 4155 if (res == 0 && (refobj->symbolic || 4156 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4157 req->sym_out = req1.sym_out; 4158 req->defobj_out = req1.defobj_out; 4159 assert(req->defobj_out != NULL); 4160 } 4161 if (refobj->symbolic || req->defobj_out != NULL) 4162 donelist_check(&donelist, refobj); 4163 4164 symlook_global(req, &donelist); 4165 4166 /* Search all dlopened DAGs containing the referencing object. */ 4167 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4168 if (req->sym_out != NULL && 4169 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4170 break; 4171 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4172 if (res == 0 && (req->sym_out == NULL || 4173 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4174 req->sym_out = req1.sym_out; 4175 req->defobj_out = req1.defobj_out; 4176 assert(req->defobj_out != NULL); 4177 } 4178 } 4179 4180 /* 4181 * Search the dynamic linker itself, and possibly resolve the 4182 * symbol from there. This is how the application links to 4183 * dynamic linker services such as dlopen. 4184 */ 4185 if (req->sym_out == NULL || 4186 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4187 res = symlook_obj(&req1, &obj_rtld); 4188 if (res == 0) { 4189 req->sym_out = req1.sym_out; 4190 req->defobj_out = req1.defobj_out; 4191 assert(req->defobj_out != NULL); 4192 } 4193 } 4194 4195 return (req->sym_out != NULL ? 0 : ESRCH); 4196 } 4197 4198 static int 4199 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4200 { 4201 const Elf_Sym *def; 4202 const Obj_Entry *defobj; 4203 const Objlist_Entry *elm; 4204 SymLook req1; 4205 int res; 4206 4207 def = NULL; 4208 defobj = NULL; 4209 STAILQ_FOREACH(elm, objlist, link) { 4210 if (donelist_check(dlp, elm->obj)) 4211 continue; 4212 symlook_init_from_req(&req1, req); 4213 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4214 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4215 def = req1.sym_out; 4216 defobj = req1.defobj_out; 4217 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4218 break; 4219 } 4220 } 4221 } 4222 if (def != NULL) { 4223 req->sym_out = def; 4224 req->defobj_out = defobj; 4225 return (0); 4226 } 4227 return (ESRCH); 4228 } 4229 4230 /* 4231 * Search the chain of DAGS cointed to by the given Needed_Entry 4232 * for a symbol of the given name. Each DAG is scanned completely 4233 * before advancing to the next one. Returns a pointer to the symbol, 4234 * or NULL if no definition was found. 4235 */ 4236 static int 4237 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4238 { 4239 const Elf_Sym *def; 4240 const Needed_Entry *n; 4241 const Obj_Entry *defobj; 4242 SymLook req1; 4243 int res; 4244 4245 def = NULL; 4246 defobj = NULL; 4247 symlook_init_from_req(&req1, req); 4248 for (n = needed; n != NULL; n = n->next) { 4249 if (n->obj == NULL || 4250 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4251 continue; 4252 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4253 def = req1.sym_out; 4254 defobj = req1.defobj_out; 4255 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4256 break; 4257 } 4258 } 4259 if (def != NULL) { 4260 req->sym_out = def; 4261 req->defobj_out = defobj; 4262 return (0); 4263 } 4264 return (ESRCH); 4265 } 4266 4267 /* 4268 * Search the symbol table of a single shared object for a symbol of 4269 * the given name and version, if requested. Returns a pointer to the 4270 * symbol, or NULL if no definition was found. If the object is 4271 * filter, return filtered symbol from filtee. 4272 * 4273 * The symbol's hash value is passed in for efficiency reasons; that 4274 * eliminates many recomputations of the hash value. 4275 */ 4276 int 4277 symlook_obj(SymLook *req, const Obj_Entry *obj) 4278 { 4279 DoneList donelist; 4280 SymLook req1; 4281 int flags, res, mres; 4282 4283 /* 4284 * If there is at least one valid hash at this point, we prefer to 4285 * use the faster GNU version if available. 4286 */ 4287 if (obj->valid_hash_gnu) 4288 mres = symlook_obj1_gnu(req, obj); 4289 else if (obj->valid_hash_sysv) 4290 mres = symlook_obj1_sysv(req, obj); 4291 else 4292 return (EINVAL); 4293 4294 if (mres == 0) { 4295 if (obj->needed_filtees != NULL) { 4296 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4297 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4298 donelist_init(&donelist); 4299 symlook_init_from_req(&req1, req); 4300 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4301 if (res == 0) { 4302 req->sym_out = req1.sym_out; 4303 req->defobj_out = req1.defobj_out; 4304 } 4305 return (res); 4306 } 4307 if (obj->needed_aux_filtees != NULL) { 4308 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4309 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4310 donelist_init(&donelist); 4311 symlook_init_from_req(&req1, req); 4312 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4313 if (res == 0) { 4314 req->sym_out = req1.sym_out; 4315 req->defobj_out = req1.defobj_out; 4316 return (res); 4317 } 4318 } 4319 } 4320 return (mres); 4321 } 4322 4323 /* Symbol match routine common to both hash functions */ 4324 static bool 4325 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4326 const unsigned long symnum) 4327 { 4328 Elf_Versym verndx; 4329 const Elf_Sym *symp; 4330 const char *strp; 4331 4332 symp = obj->symtab + symnum; 4333 strp = obj->strtab + symp->st_name; 4334 4335 switch (ELF_ST_TYPE(symp->st_info)) { 4336 case STT_FUNC: 4337 case STT_NOTYPE: 4338 case STT_OBJECT: 4339 case STT_COMMON: 4340 case STT_GNU_IFUNC: 4341 if (symp->st_value == 0) 4342 return (false); 4343 /* fallthrough */ 4344 case STT_TLS: 4345 if (symp->st_shndx != SHN_UNDEF) 4346 break; 4347 #ifndef __mips__ 4348 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4349 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4350 break; 4351 #endif 4352 /* fallthrough */ 4353 default: 4354 return (false); 4355 } 4356 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4357 return (false); 4358 4359 if (req->ventry == NULL) { 4360 if (obj->versyms != NULL) { 4361 verndx = VER_NDX(obj->versyms[symnum]); 4362 if (verndx > obj->vernum) { 4363 _rtld_error( 4364 "%s: symbol %s references wrong version %d", 4365 obj->path, obj->strtab + symnum, verndx); 4366 return (false); 4367 } 4368 /* 4369 * If we are not called from dlsym (i.e. this 4370 * is a normal relocation from unversioned 4371 * binary), accept the symbol immediately if 4372 * it happens to have first version after this 4373 * shared object became versioned. Otherwise, 4374 * if symbol is versioned and not hidden, 4375 * remember it. If it is the only symbol with 4376 * this name exported by the shared object, it 4377 * will be returned as a match by the calling 4378 * function. If symbol is global (verndx < 2) 4379 * accept it unconditionally. 4380 */ 4381 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4382 verndx == VER_NDX_GIVEN) { 4383 result->sym_out = symp; 4384 return (true); 4385 } 4386 else if (verndx >= VER_NDX_GIVEN) { 4387 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4388 == 0) { 4389 if (result->vsymp == NULL) 4390 result->vsymp = symp; 4391 result->vcount++; 4392 } 4393 return (false); 4394 } 4395 } 4396 result->sym_out = symp; 4397 return (true); 4398 } 4399 if (obj->versyms == NULL) { 4400 if (object_match_name(obj, req->ventry->name)) { 4401 _rtld_error("%s: object %s should provide version %s " 4402 "for symbol %s", obj_rtld.path, obj->path, 4403 req->ventry->name, obj->strtab + symnum); 4404 return (false); 4405 } 4406 } else { 4407 verndx = VER_NDX(obj->versyms[symnum]); 4408 if (verndx > obj->vernum) { 4409 _rtld_error("%s: symbol %s references wrong version %d", 4410 obj->path, obj->strtab + symnum, verndx); 4411 return (false); 4412 } 4413 if (obj->vertab[verndx].hash != req->ventry->hash || 4414 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4415 /* 4416 * Version does not match. Look if this is a 4417 * global symbol and if it is not hidden. If 4418 * global symbol (verndx < 2) is available, 4419 * use it. Do not return symbol if we are 4420 * called by dlvsym, because dlvsym looks for 4421 * a specific version and default one is not 4422 * what dlvsym wants. 4423 */ 4424 if ((req->flags & SYMLOOK_DLSYM) || 4425 (verndx >= VER_NDX_GIVEN) || 4426 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4427 return (false); 4428 } 4429 } 4430 result->sym_out = symp; 4431 return (true); 4432 } 4433 4434 /* 4435 * Search for symbol using SysV hash function. 4436 * obj->buckets is known not to be NULL at this point; the test for this was 4437 * performed with the obj->valid_hash_sysv assignment. 4438 */ 4439 static int 4440 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4441 { 4442 unsigned long symnum; 4443 Sym_Match_Result matchres; 4444 4445 matchres.sym_out = NULL; 4446 matchres.vsymp = NULL; 4447 matchres.vcount = 0; 4448 4449 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4450 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4451 if (symnum >= obj->nchains) 4452 return (ESRCH); /* Bad object */ 4453 4454 if (matched_symbol(req, obj, &matchres, symnum)) { 4455 req->sym_out = matchres.sym_out; 4456 req->defobj_out = obj; 4457 return (0); 4458 } 4459 } 4460 if (matchres.vcount == 1) { 4461 req->sym_out = matchres.vsymp; 4462 req->defobj_out = obj; 4463 return (0); 4464 } 4465 return (ESRCH); 4466 } 4467 4468 /* Search for symbol using GNU hash function */ 4469 static int 4470 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4471 { 4472 Elf_Addr bloom_word; 4473 const Elf32_Word *hashval; 4474 Elf32_Word bucket; 4475 Sym_Match_Result matchres; 4476 unsigned int h1, h2; 4477 unsigned long symnum; 4478 4479 matchres.sym_out = NULL; 4480 matchres.vsymp = NULL; 4481 matchres.vcount = 0; 4482 4483 /* Pick right bitmask word from Bloom filter array */ 4484 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4485 obj->maskwords_bm_gnu]; 4486 4487 /* Calculate modulus word size of gnu hash and its derivative */ 4488 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4489 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4490 4491 /* Filter out the "definitely not in set" queries */ 4492 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4493 return (ESRCH); 4494 4495 /* Locate hash chain and corresponding value element*/ 4496 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4497 if (bucket == 0) 4498 return (ESRCH); 4499 hashval = &obj->chain_zero_gnu[bucket]; 4500 do { 4501 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4502 symnum = hashval - obj->chain_zero_gnu; 4503 if (matched_symbol(req, obj, &matchres, symnum)) { 4504 req->sym_out = matchres.sym_out; 4505 req->defobj_out = obj; 4506 return (0); 4507 } 4508 } 4509 } while ((*hashval++ & 1) == 0); 4510 if (matchres.vcount == 1) { 4511 req->sym_out = matchres.vsymp; 4512 req->defobj_out = obj; 4513 return (0); 4514 } 4515 return (ESRCH); 4516 } 4517 4518 static void 4519 trace_loaded_objects(Obj_Entry *obj) 4520 { 4521 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4522 int c; 4523 4524 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4525 main_local = ""; 4526 4527 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4528 fmt1 = "\t%o => %p (%x)\n"; 4529 4530 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4531 fmt2 = "\t%o (%x)\n"; 4532 4533 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4534 4535 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4536 Needed_Entry *needed; 4537 const char *name, *path; 4538 bool is_lib; 4539 4540 if (obj->marker) 4541 continue; 4542 if (list_containers && obj->needed != NULL) 4543 rtld_printf("%s:\n", obj->path); 4544 for (needed = obj->needed; needed; needed = needed->next) { 4545 if (needed->obj != NULL) { 4546 if (needed->obj->traced && !list_containers) 4547 continue; 4548 needed->obj->traced = true; 4549 path = needed->obj->path; 4550 } else 4551 path = "not found"; 4552 4553 name = obj->strtab + needed->name; 4554 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4555 4556 fmt = is_lib ? fmt1 : fmt2; 4557 while ((c = *fmt++) != '\0') { 4558 switch (c) { 4559 default: 4560 rtld_putchar(c); 4561 continue; 4562 case '\\': 4563 switch (c = *fmt) { 4564 case '\0': 4565 continue; 4566 case 'n': 4567 rtld_putchar('\n'); 4568 break; 4569 case 't': 4570 rtld_putchar('\t'); 4571 break; 4572 } 4573 break; 4574 case '%': 4575 switch (c = *fmt) { 4576 case '\0': 4577 continue; 4578 case '%': 4579 default: 4580 rtld_putchar(c); 4581 break; 4582 case 'A': 4583 rtld_putstr(main_local); 4584 break; 4585 case 'a': 4586 rtld_putstr(obj_main->path); 4587 break; 4588 case 'o': 4589 rtld_putstr(name); 4590 break; 4591 #if 0 4592 case 'm': 4593 rtld_printf("%d", sodp->sod_major); 4594 break; 4595 case 'n': 4596 rtld_printf("%d", sodp->sod_minor); 4597 break; 4598 #endif 4599 case 'p': 4600 rtld_putstr(path); 4601 break; 4602 case 'x': 4603 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4604 0); 4605 break; 4606 } 4607 break; 4608 } 4609 ++fmt; 4610 } 4611 } 4612 } 4613 } 4614 4615 /* 4616 * Unload a dlopened object and its dependencies from memory and from 4617 * our data structures. It is assumed that the DAG rooted in the 4618 * object has already been unreferenced, and that the object has a 4619 * reference count of 0. 4620 */ 4621 static void 4622 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4623 { 4624 Obj_Entry marker, *obj, *next; 4625 4626 assert(root->refcount == 0); 4627 4628 /* 4629 * Pass over the DAG removing unreferenced objects from 4630 * appropriate lists. 4631 */ 4632 unlink_object(root); 4633 4634 /* Unmap all objects that are no longer referenced. */ 4635 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4636 next = TAILQ_NEXT(obj, next); 4637 if (obj->marker || obj->refcount != 0) 4638 continue; 4639 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4640 obj->mapsize, 0, obj->path); 4641 dbg("unloading \"%s\"", obj->path); 4642 /* 4643 * Unlink the object now to prevent new references from 4644 * being acquired while the bind lock is dropped in 4645 * recursive dlclose() invocations. 4646 */ 4647 TAILQ_REMOVE(&obj_list, obj, next); 4648 obj_count--; 4649 4650 if (obj->filtees_loaded) { 4651 if (next != NULL) { 4652 init_marker(&marker); 4653 TAILQ_INSERT_BEFORE(next, &marker, next); 4654 unload_filtees(obj, lockstate); 4655 next = TAILQ_NEXT(&marker, next); 4656 TAILQ_REMOVE(&obj_list, &marker, next); 4657 } else 4658 unload_filtees(obj, lockstate); 4659 } 4660 release_object(obj); 4661 } 4662 } 4663 4664 static void 4665 unlink_object(Obj_Entry *root) 4666 { 4667 Objlist_Entry *elm; 4668 4669 if (root->refcount == 0) { 4670 /* Remove the object from the RTLD_GLOBAL list. */ 4671 objlist_remove(&list_global, root); 4672 4673 /* Remove the object from all objects' DAG lists. */ 4674 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4675 objlist_remove(&elm->obj->dldags, root); 4676 if (elm->obj != root) 4677 unlink_object(elm->obj); 4678 } 4679 } 4680 } 4681 4682 static void 4683 ref_dag(Obj_Entry *root) 4684 { 4685 Objlist_Entry *elm; 4686 4687 assert(root->dag_inited); 4688 STAILQ_FOREACH(elm, &root->dagmembers, link) 4689 elm->obj->refcount++; 4690 } 4691 4692 static void 4693 unref_dag(Obj_Entry *root) 4694 { 4695 Objlist_Entry *elm; 4696 4697 assert(root->dag_inited); 4698 STAILQ_FOREACH(elm, &root->dagmembers, link) 4699 elm->obj->refcount--; 4700 } 4701 4702 /* 4703 * Common code for MD __tls_get_addr(). 4704 */ 4705 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4706 static void * 4707 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4708 { 4709 Elf_Addr *newdtv, *dtv; 4710 RtldLockState lockstate; 4711 int to_copy; 4712 4713 dtv = *dtvp; 4714 /* Check dtv generation in case new modules have arrived */ 4715 if (dtv[0] != tls_dtv_generation) { 4716 wlock_acquire(rtld_bind_lock, &lockstate); 4717 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4718 to_copy = dtv[1]; 4719 if (to_copy > tls_max_index) 4720 to_copy = tls_max_index; 4721 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4722 newdtv[0] = tls_dtv_generation; 4723 newdtv[1] = tls_max_index; 4724 free(dtv); 4725 lock_release(rtld_bind_lock, &lockstate); 4726 dtv = *dtvp = newdtv; 4727 } 4728 4729 /* Dynamically allocate module TLS if necessary */ 4730 if (dtv[index + 1] == 0) { 4731 /* Signal safe, wlock will block out signals. */ 4732 wlock_acquire(rtld_bind_lock, &lockstate); 4733 if (!dtv[index + 1]) 4734 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4735 lock_release(rtld_bind_lock, &lockstate); 4736 } 4737 return ((void *)(dtv[index + 1] + offset)); 4738 } 4739 4740 void * 4741 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4742 { 4743 Elf_Addr *dtv; 4744 4745 dtv = *dtvp; 4746 /* Check dtv generation in case new modules have arrived */ 4747 if (__predict_true(dtv[0] == tls_dtv_generation && 4748 dtv[index + 1] != 0)) 4749 return ((void *)(dtv[index + 1] + offset)); 4750 return (tls_get_addr_slow(dtvp, index, offset)); 4751 } 4752 4753 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4754 defined(__powerpc__) || defined(__riscv) 4755 4756 /* 4757 * Return pointer to allocated TLS block 4758 */ 4759 static void * 4760 get_tls_block_ptr(void *tcb, size_t tcbsize) 4761 { 4762 size_t extra_size, post_size, pre_size, tls_block_size; 4763 size_t tls_init_align; 4764 4765 tls_init_align = MAX(obj_main->tlsalign, 1); 4766 4767 /* Compute fragments sizes. */ 4768 extra_size = tcbsize - TLS_TCB_SIZE; 4769 post_size = calculate_tls_post_size(tls_init_align); 4770 tls_block_size = tcbsize + post_size; 4771 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4772 4773 return ((char *)tcb - pre_size - extra_size); 4774 } 4775 4776 /* 4777 * Allocate Static TLS using the Variant I method. 4778 * 4779 * For details on the layout, see lib/libc/gen/tls.c. 4780 * 4781 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4782 * it is based on tls_last_offset, and TLS offsets here are really TCB 4783 * offsets, whereas libc's tls_static_space is just the executable's static 4784 * TLS segment. 4785 */ 4786 void * 4787 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4788 { 4789 Obj_Entry *obj; 4790 char *tls_block; 4791 Elf_Addr *dtv, **tcb; 4792 Elf_Addr addr; 4793 Elf_Addr i; 4794 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4795 size_t tls_init_align; 4796 4797 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4798 return (oldtcb); 4799 4800 assert(tcbsize >= TLS_TCB_SIZE); 4801 maxalign = MAX(tcbalign, tls_static_max_align); 4802 tls_init_align = MAX(obj_main->tlsalign, 1); 4803 4804 /* Compute fragmets sizes. */ 4805 extra_size = tcbsize - TLS_TCB_SIZE; 4806 post_size = calculate_tls_post_size(tls_init_align); 4807 tls_block_size = tcbsize + post_size; 4808 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4809 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 4810 4811 /* Allocate whole TLS block */ 4812 tls_block = malloc_aligned(tls_block_size, maxalign); 4813 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 4814 4815 if (oldtcb != NULL) { 4816 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 4817 tls_static_space); 4818 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 4819 4820 /* Adjust the DTV. */ 4821 dtv = tcb[0]; 4822 for (i = 0; i < dtv[1]; i++) { 4823 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4824 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4825 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 4826 } 4827 } 4828 } else { 4829 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4830 tcb[0] = dtv; 4831 dtv[0] = tls_dtv_generation; 4832 dtv[1] = tls_max_index; 4833 4834 for (obj = globallist_curr(objs); obj != NULL; 4835 obj = globallist_next(obj)) { 4836 if (obj->tlsoffset > 0) { 4837 addr = (Elf_Addr)tcb + obj->tlsoffset; 4838 if (obj->tlsinitsize > 0) 4839 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4840 if (obj->tlssize > obj->tlsinitsize) 4841 memset((void*)(addr + obj->tlsinitsize), 0, 4842 obj->tlssize - obj->tlsinitsize); 4843 dtv[obj->tlsindex + 1] = addr; 4844 } 4845 } 4846 } 4847 4848 return (tcb); 4849 } 4850 4851 void 4852 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 4853 { 4854 Elf_Addr *dtv; 4855 Elf_Addr tlsstart, tlsend; 4856 size_t post_size; 4857 size_t dtvsize, i, tls_init_align; 4858 4859 assert(tcbsize >= TLS_TCB_SIZE); 4860 tls_init_align = MAX(obj_main->tlsalign, 1); 4861 4862 /* Compute fragments sizes. */ 4863 post_size = calculate_tls_post_size(tls_init_align); 4864 4865 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 4866 tlsend = (Elf_Addr)tcb + tls_static_space; 4867 4868 dtv = *(Elf_Addr **)tcb; 4869 dtvsize = dtv[1]; 4870 for (i = 0; i < dtvsize; i++) { 4871 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4872 free((void*)dtv[i+2]); 4873 } 4874 } 4875 free(dtv); 4876 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 4877 } 4878 4879 #endif 4880 4881 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4882 4883 /* 4884 * Allocate Static TLS using the Variant II method. 4885 */ 4886 void * 4887 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4888 { 4889 Obj_Entry *obj; 4890 size_t size, ralign; 4891 char *tls; 4892 Elf_Addr *dtv, *olddtv; 4893 Elf_Addr segbase, oldsegbase, addr; 4894 size_t i; 4895 4896 ralign = tcbalign; 4897 if (tls_static_max_align > ralign) 4898 ralign = tls_static_max_align; 4899 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4900 4901 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4902 tls = malloc_aligned(size, ralign); 4903 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4904 4905 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4906 ((Elf_Addr*)segbase)[0] = segbase; 4907 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4908 4909 dtv[0] = tls_dtv_generation; 4910 dtv[1] = tls_max_index; 4911 4912 if (oldtls) { 4913 /* 4914 * Copy the static TLS block over whole. 4915 */ 4916 oldsegbase = (Elf_Addr) oldtls; 4917 memcpy((void *)(segbase - tls_static_space), 4918 (const void *)(oldsegbase - tls_static_space), 4919 tls_static_space); 4920 4921 /* 4922 * If any dynamic TLS blocks have been created tls_get_addr(), 4923 * move them over. 4924 */ 4925 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4926 for (i = 0; i < olddtv[1]; i++) { 4927 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4928 dtv[i+2] = olddtv[i+2]; 4929 olddtv[i+2] = 0; 4930 } 4931 } 4932 4933 /* 4934 * We assume that this block was the one we created with 4935 * allocate_initial_tls(). 4936 */ 4937 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4938 } else { 4939 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4940 if (obj->marker || obj->tlsoffset == 0) 4941 continue; 4942 addr = segbase - obj->tlsoffset; 4943 memset((void*)(addr + obj->tlsinitsize), 4944 0, obj->tlssize - obj->tlsinitsize); 4945 if (obj->tlsinit) { 4946 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4947 obj->static_tls_copied = true; 4948 } 4949 dtv[obj->tlsindex + 1] = addr; 4950 } 4951 } 4952 4953 return (void*) segbase; 4954 } 4955 4956 void 4957 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 4958 { 4959 Elf_Addr* dtv; 4960 size_t size, ralign; 4961 int dtvsize, i; 4962 Elf_Addr tlsstart, tlsend; 4963 4964 /* 4965 * Figure out the size of the initial TLS block so that we can 4966 * find stuff which ___tls_get_addr() allocated dynamically. 4967 */ 4968 ralign = tcbalign; 4969 if (tls_static_max_align > ralign) 4970 ralign = tls_static_max_align; 4971 size = round(tls_static_space, ralign); 4972 4973 dtv = ((Elf_Addr**)tls)[1]; 4974 dtvsize = dtv[1]; 4975 tlsend = (Elf_Addr) tls; 4976 tlsstart = tlsend - size; 4977 for (i = 0; i < dtvsize; i++) { 4978 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4979 free_aligned((void *)dtv[i + 2]); 4980 } 4981 } 4982 4983 free_aligned((void *)tlsstart); 4984 free((void*) dtv); 4985 } 4986 4987 #endif 4988 4989 /* 4990 * Allocate TLS block for module with given index. 4991 */ 4992 void * 4993 allocate_module_tls(int index) 4994 { 4995 Obj_Entry* obj; 4996 char* p; 4997 4998 TAILQ_FOREACH(obj, &obj_list, next) { 4999 if (obj->marker) 5000 continue; 5001 if (obj->tlsindex == index) 5002 break; 5003 } 5004 if (!obj) { 5005 _rtld_error("Can't find module with TLS index %d", index); 5006 rtld_die(); 5007 } 5008 5009 p = malloc_aligned(obj->tlssize, obj->tlsalign); 5010 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5011 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5012 5013 return p; 5014 } 5015 5016 bool 5017 allocate_tls_offset(Obj_Entry *obj) 5018 { 5019 size_t off; 5020 5021 if (obj->tls_done) 5022 return true; 5023 5024 if (obj->tlssize == 0) { 5025 obj->tls_done = true; 5026 return true; 5027 } 5028 5029 if (tls_last_offset == 0) 5030 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 5031 else 5032 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5033 obj->tlssize, obj->tlsalign); 5034 5035 /* 5036 * If we have already fixed the size of the static TLS block, we 5037 * must stay within that size. When allocating the static TLS, we 5038 * leave a small amount of space spare to be used for dynamically 5039 * loading modules which use static TLS. 5040 */ 5041 if (tls_static_space != 0) { 5042 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 5043 return false; 5044 } else if (obj->tlsalign > tls_static_max_align) { 5045 tls_static_max_align = obj->tlsalign; 5046 } 5047 5048 tls_last_offset = obj->tlsoffset = off; 5049 tls_last_size = obj->tlssize; 5050 obj->tls_done = true; 5051 5052 return true; 5053 } 5054 5055 void 5056 free_tls_offset(Obj_Entry *obj) 5057 { 5058 5059 /* 5060 * If we were the last thing to allocate out of the static TLS 5061 * block, we give our space back to the 'allocator'. This is a 5062 * simplistic workaround to allow libGL.so.1 to be loaded and 5063 * unloaded multiple times. 5064 */ 5065 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5066 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5067 tls_last_offset -= obj->tlssize; 5068 tls_last_size = 0; 5069 } 5070 } 5071 5072 void * 5073 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5074 { 5075 void *ret; 5076 RtldLockState lockstate; 5077 5078 wlock_acquire(rtld_bind_lock, &lockstate); 5079 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5080 tcbsize, tcbalign); 5081 lock_release(rtld_bind_lock, &lockstate); 5082 return (ret); 5083 } 5084 5085 void 5086 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5087 { 5088 RtldLockState lockstate; 5089 5090 wlock_acquire(rtld_bind_lock, &lockstate); 5091 free_tls(tcb, tcbsize, tcbalign); 5092 lock_release(rtld_bind_lock, &lockstate); 5093 } 5094 5095 static void 5096 object_add_name(Obj_Entry *obj, const char *name) 5097 { 5098 Name_Entry *entry; 5099 size_t len; 5100 5101 len = strlen(name); 5102 entry = malloc(sizeof(Name_Entry) + len); 5103 5104 if (entry != NULL) { 5105 strcpy(entry->name, name); 5106 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5107 } 5108 } 5109 5110 static int 5111 object_match_name(const Obj_Entry *obj, const char *name) 5112 { 5113 Name_Entry *entry; 5114 5115 STAILQ_FOREACH(entry, &obj->names, link) { 5116 if (strcmp(name, entry->name) == 0) 5117 return (1); 5118 } 5119 return (0); 5120 } 5121 5122 static Obj_Entry * 5123 locate_dependency(const Obj_Entry *obj, const char *name) 5124 { 5125 const Objlist_Entry *entry; 5126 const Needed_Entry *needed; 5127 5128 STAILQ_FOREACH(entry, &list_main, link) { 5129 if (object_match_name(entry->obj, name)) 5130 return entry->obj; 5131 } 5132 5133 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5134 if (strcmp(obj->strtab + needed->name, name) == 0 || 5135 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5136 /* 5137 * If there is DT_NEEDED for the name we are looking for, 5138 * we are all set. Note that object might not be found if 5139 * dependency was not loaded yet, so the function can 5140 * return NULL here. This is expected and handled 5141 * properly by the caller. 5142 */ 5143 return (needed->obj); 5144 } 5145 } 5146 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5147 obj->path, name); 5148 rtld_die(); 5149 } 5150 5151 static int 5152 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5153 const Elf_Vernaux *vna) 5154 { 5155 const Elf_Verdef *vd; 5156 const char *vername; 5157 5158 vername = refobj->strtab + vna->vna_name; 5159 vd = depobj->verdef; 5160 if (vd == NULL) { 5161 _rtld_error("%s: version %s required by %s not defined", 5162 depobj->path, vername, refobj->path); 5163 return (-1); 5164 } 5165 for (;;) { 5166 if (vd->vd_version != VER_DEF_CURRENT) { 5167 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5168 depobj->path, vd->vd_version); 5169 return (-1); 5170 } 5171 if (vna->vna_hash == vd->vd_hash) { 5172 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5173 ((const char *)vd + vd->vd_aux); 5174 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5175 return (0); 5176 } 5177 if (vd->vd_next == 0) 5178 break; 5179 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5180 } 5181 if (vna->vna_flags & VER_FLG_WEAK) 5182 return (0); 5183 _rtld_error("%s: version %s required by %s not found", 5184 depobj->path, vername, refobj->path); 5185 return (-1); 5186 } 5187 5188 static int 5189 rtld_verify_object_versions(Obj_Entry *obj) 5190 { 5191 const Elf_Verneed *vn; 5192 const Elf_Verdef *vd; 5193 const Elf_Verdaux *vda; 5194 const Elf_Vernaux *vna; 5195 const Obj_Entry *depobj; 5196 int maxvernum, vernum; 5197 5198 if (obj->ver_checked) 5199 return (0); 5200 obj->ver_checked = true; 5201 5202 maxvernum = 0; 5203 /* 5204 * Walk over defined and required version records and figure out 5205 * max index used by any of them. Do very basic sanity checking 5206 * while there. 5207 */ 5208 vn = obj->verneed; 5209 while (vn != NULL) { 5210 if (vn->vn_version != VER_NEED_CURRENT) { 5211 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5212 obj->path, vn->vn_version); 5213 return (-1); 5214 } 5215 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5216 for (;;) { 5217 vernum = VER_NEED_IDX(vna->vna_other); 5218 if (vernum > maxvernum) 5219 maxvernum = vernum; 5220 if (vna->vna_next == 0) 5221 break; 5222 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5223 } 5224 if (vn->vn_next == 0) 5225 break; 5226 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5227 } 5228 5229 vd = obj->verdef; 5230 while (vd != NULL) { 5231 if (vd->vd_version != VER_DEF_CURRENT) { 5232 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5233 obj->path, vd->vd_version); 5234 return (-1); 5235 } 5236 vernum = VER_DEF_IDX(vd->vd_ndx); 5237 if (vernum > maxvernum) 5238 maxvernum = vernum; 5239 if (vd->vd_next == 0) 5240 break; 5241 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5242 } 5243 5244 if (maxvernum == 0) 5245 return (0); 5246 5247 /* 5248 * Store version information in array indexable by version index. 5249 * Verify that object version requirements are satisfied along the 5250 * way. 5251 */ 5252 obj->vernum = maxvernum + 1; 5253 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5254 5255 vd = obj->verdef; 5256 while (vd != NULL) { 5257 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5258 vernum = VER_DEF_IDX(vd->vd_ndx); 5259 assert(vernum <= maxvernum); 5260 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5261 obj->vertab[vernum].hash = vd->vd_hash; 5262 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5263 obj->vertab[vernum].file = NULL; 5264 obj->vertab[vernum].flags = 0; 5265 } 5266 if (vd->vd_next == 0) 5267 break; 5268 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5269 } 5270 5271 vn = obj->verneed; 5272 while (vn != NULL) { 5273 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5274 if (depobj == NULL) 5275 return (-1); 5276 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5277 for (;;) { 5278 if (check_object_provided_version(obj, depobj, vna)) 5279 return (-1); 5280 vernum = VER_NEED_IDX(vna->vna_other); 5281 assert(vernum <= maxvernum); 5282 obj->vertab[vernum].hash = vna->vna_hash; 5283 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5284 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5285 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5286 VER_INFO_HIDDEN : 0; 5287 if (vna->vna_next == 0) 5288 break; 5289 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5290 } 5291 if (vn->vn_next == 0) 5292 break; 5293 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5294 } 5295 return 0; 5296 } 5297 5298 static int 5299 rtld_verify_versions(const Objlist *objlist) 5300 { 5301 Objlist_Entry *entry; 5302 int rc; 5303 5304 rc = 0; 5305 STAILQ_FOREACH(entry, objlist, link) { 5306 /* 5307 * Skip dummy objects or objects that have their version requirements 5308 * already checked. 5309 */ 5310 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5311 continue; 5312 if (rtld_verify_object_versions(entry->obj) == -1) { 5313 rc = -1; 5314 if (ld_tracing == NULL) 5315 break; 5316 } 5317 } 5318 if (rc == 0 || ld_tracing != NULL) 5319 rc = rtld_verify_object_versions(&obj_rtld); 5320 return rc; 5321 } 5322 5323 const Ver_Entry * 5324 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5325 { 5326 Elf_Versym vernum; 5327 5328 if (obj->vertab) { 5329 vernum = VER_NDX(obj->versyms[symnum]); 5330 if (vernum >= obj->vernum) { 5331 _rtld_error("%s: symbol %s has wrong verneed value %d", 5332 obj->path, obj->strtab + symnum, vernum); 5333 } else if (obj->vertab[vernum].hash != 0) { 5334 return &obj->vertab[vernum]; 5335 } 5336 } 5337 return NULL; 5338 } 5339 5340 int 5341 _rtld_get_stack_prot(void) 5342 { 5343 5344 return (stack_prot); 5345 } 5346 5347 int 5348 _rtld_is_dlopened(void *arg) 5349 { 5350 Obj_Entry *obj; 5351 RtldLockState lockstate; 5352 int res; 5353 5354 rlock_acquire(rtld_bind_lock, &lockstate); 5355 obj = dlcheck(arg); 5356 if (obj == NULL) 5357 obj = obj_from_addr(arg); 5358 if (obj == NULL) { 5359 _rtld_error("No shared object contains address"); 5360 lock_release(rtld_bind_lock, &lockstate); 5361 return (-1); 5362 } 5363 res = obj->dlopened ? 1 : 0; 5364 lock_release(rtld_bind_lock, &lockstate); 5365 return (res); 5366 } 5367 5368 static int 5369 obj_remap_relro(Obj_Entry *obj, int prot) 5370 { 5371 5372 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5373 prot) == -1) { 5374 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5375 obj->path, prot, rtld_strerror(errno)); 5376 return (-1); 5377 } 5378 return (0); 5379 } 5380 5381 static int 5382 obj_disable_relro(Obj_Entry *obj) 5383 { 5384 5385 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5386 } 5387 5388 static int 5389 obj_enforce_relro(Obj_Entry *obj) 5390 { 5391 5392 return (obj_remap_relro(obj, PROT_READ)); 5393 } 5394 5395 static void 5396 map_stacks_exec(RtldLockState *lockstate) 5397 { 5398 void (*thr_map_stacks_exec)(void); 5399 5400 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5401 return; 5402 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5403 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5404 if (thr_map_stacks_exec != NULL) { 5405 stack_prot |= PROT_EXEC; 5406 thr_map_stacks_exec(); 5407 } 5408 } 5409 5410 static void 5411 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5412 { 5413 Objlist_Entry *elm; 5414 Obj_Entry *obj; 5415 void (*distrib)(size_t, void *, size_t, size_t); 5416 5417 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5418 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5419 if (distrib == NULL) 5420 return; 5421 STAILQ_FOREACH(elm, list, link) { 5422 obj = elm->obj; 5423 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5424 continue; 5425 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5426 obj->tlssize); 5427 obj->static_tls_copied = true; 5428 } 5429 } 5430 5431 void 5432 symlook_init(SymLook *dst, const char *name) 5433 { 5434 5435 bzero(dst, sizeof(*dst)); 5436 dst->name = name; 5437 dst->hash = elf_hash(name); 5438 dst->hash_gnu = gnu_hash(name); 5439 } 5440 5441 static void 5442 symlook_init_from_req(SymLook *dst, const SymLook *src) 5443 { 5444 5445 dst->name = src->name; 5446 dst->hash = src->hash; 5447 dst->hash_gnu = src->hash_gnu; 5448 dst->ventry = src->ventry; 5449 dst->flags = src->flags; 5450 dst->defobj_out = NULL; 5451 dst->sym_out = NULL; 5452 dst->lockstate = src->lockstate; 5453 } 5454 5455 static int 5456 open_binary_fd(const char *argv0, bool search_in_path) 5457 { 5458 char *pathenv, *pe, binpath[PATH_MAX]; 5459 int fd; 5460 5461 if (search_in_path && strchr(argv0, '/') == NULL) { 5462 pathenv = getenv("PATH"); 5463 if (pathenv == NULL) { 5464 _rtld_error("-p and no PATH environment variable"); 5465 rtld_die(); 5466 } 5467 pathenv = strdup(pathenv); 5468 if (pathenv == NULL) { 5469 _rtld_error("Cannot allocate memory"); 5470 rtld_die(); 5471 } 5472 fd = -1; 5473 errno = ENOENT; 5474 while ((pe = strsep(&pathenv, ":")) != NULL) { 5475 if (strlcpy(binpath, pe, sizeof(binpath)) >= 5476 sizeof(binpath)) 5477 continue; 5478 if (binpath[0] != '\0' && 5479 strlcat(binpath, "/", sizeof(binpath)) >= 5480 sizeof(binpath)) 5481 continue; 5482 if (strlcat(binpath, argv0, sizeof(binpath)) >= 5483 sizeof(binpath)) 5484 continue; 5485 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5486 if (fd != -1 || errno != ENOENT) 5487 break; 5488 } 5489 free(pathenv); 5490 } else { 5491 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5492 } 5493 5494 if (fd == -1) { 5495 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5496 rtld_die(); 5497 } 5498 return (fd); 5499 } 5500 5501 /* 5502 * Parse a set of command-line arguments. 5503 */ 5504 static int 5505 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp) 5506 { 5507 const char *arg; 5508 int fd, i, j, arglen; 5509 char opt; 5510 5511 dbg("Parsing command-line arguments"); 5512 *use_pathp = false; 5513 *fdp = -1; 5514 5515 for (i = 1; i < argc; i++ ) { 5516 arg = argv[i]; 5517 dbg("argv[%d]: '%s'", i, arg); 5518 5519 /* 5520 * rtld arguments end with an explicit "--" or with the first 5521 * non-prefixed argument. 5522 */ 5523 if (strcmp(arg, "--") == 0) { 5524 i++; 5525 break; 5526 } 5527 if (arg[0] != '-') 5528 break; 5529 5530 /* 5531 * All other arguments are single-character options that can 5532 * be combined, so we need to search through `arg` for them. 5533 */ 5534 arglen = strlen(arg); 5535 for (j = 1; j < arglen; j++) { 5536 opt = arg[j]; 5537 if (opt == 'h') { 5538 print_usage(argv[0]); 5539 _exit(0); 5540 } else if (opt == 'f') { 5541 /* 5542 * -f XX can be used to specify a descriptor for the 5543 * binary named at the command line (i.e., the later 5544 * argument will specify the process name but the 5545 * descriptor is what will actually be executed) 5546 */ 5547 if (j != arglen - 1) { 5548 /* -f must be the last option in, e.g., -abcf */ 5549 _rtld_error("Invalid options: %s", arg); 5550 rtld_die(); 5551 } 5552 i++; 5553 fd = parse_integer(argv[i]); 5554 if (fd == -1) { 5555 _rtld_error("Invalid file descriptor: '%s'", 5556 argv[i]); 5557 rtld_die(); 5558 } 5559 *fdp = fd; 5560 break; 5561 } else if (opt == 'p') { 5562 *use_pathp = true; 5563 } else { 5564 _rtld_error("Invalid argument: '%s'", arg); 5565 print_usage(argv[0]); 5566 rtld_die(); 5567 } 5568 } 5569 } 5570 5571 return (i); 5572 } 5573 5574 /* 5575 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5576 */ 5577 static int 5578 parse_integer(const char *str) 5579 { 5580 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5581 const char *orig; 5582 int n; 5583 char c; 5584 5585 orig = str; 5586 n = 0; 5587 for (c = *str; c != '\0'; c = *++str) { 5588 if (c < '0' || c > '9') 5589 return (-1); 5590 5591 n *= RADIX; 5592 n += c - '0'; 5593 } 5594 5595 /* Make sure we actually parsed something. */ 5596 if (str == orig) 5597 return (-1); 5598 return (n); 5599 } 5600 5601 static void 5602 print_usage(const char *argv0) 5603 { 5604 5605 rtld_printf("Usage: %s [-h] [-f <FD>] [--] <binary> [<args>]\n" 5606 "\n" 5607 "Options:\n" 5608 " -h Display this help message\n" 5609 " -p Search in PATH for named binary\n" 5610 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5611 " -- End of RTLD options\n" 5612 " <binary> Name of process to execute\n" 5613 " <args> Arguments to the executed process\n", argv0); 5614 } 5615 5616 /* 5617 * Overrides for libc_pic-provided functions. 5618 */ 5619 5620 int 5621 __getosreldate(void) 5622 { 5623 size_t len; 5624 int oid[2]; 5625 int error, osrel; 5626 5627 if (osreldate != 0) 5628 return (osreldate); 5629 5630 oid[0] = CTL_KERN; 5631 oid[1] = KERN_OSRELDATE; 5632 osrel = 0; 5633 len = sizeof(osrel); 5634 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5635 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5636 osreldate = osrel; 5637 return (osreldate); 5638 } 5639 5640 void 5641 exit(int status) 5642 { 5643 5644 _exit(status); 5645 } 5646 5647 void (*__cleanup)(void); 5648 int __isthreaded = 0; 5649 int _thread_autoinit_dummy_decl = 1; 5650 5651 /* 5652 * No unresolved symbols for rtld. 5653 */ 5654 void 5655 __pthread_cxa_finalize(struct dl_phdr_info *a __unused) 5656 { 5657 } 5658 5659 const char * 5660 rtld_strerror(int errnum) 5661 { 5662 5663 if (errnum < 0 || errnum >= sys_nerr) 5664 return ("Unknown error"); 5665 return (sys_errlist[errnum]); 5666 } 5667 5668 /* 5669 * No ifunc relocations. 5670 */ 5671 void * 5672 memset(void *dest, int c, size_t len) 5673 { 5674 size_t i; 5675 5676 for (i = 0; i < len; i++) 5677 ((char *)dest)[i] = c; 5678 return (dest); 5679 } 5680 5681 void 5682 bzero(void *dest, size_t len) 5683 { 5684 size_t i; 5685 5686 for (i = 0; i < len; i++) 5687 ((char *)dest)[i] = 0; 5688 } 5689 5690 /* malloc */ 5691 void * 5692 malloc(size_t nbytes) 5693 { 5694 5695 return (__crt_malloc(nbytes)); 5696 } 5697 5698 void * 5699 calloc(size_t num, size_t size) 5700 { 5701 5702 return (__crt_calloc(num, size)); 5703 } 5704 5705 void 5706 free(void *cp) 5707 { 5708 5709 __crt_free(cp); 5710 } 5711 5712 void * 5713 realloc(void *cp, size_t nbytes) 5714 { 5715 5716 return (__crt_realloc(cp, nbytes)); 5717 } 5718