1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <jdp@polstra.com>. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/uio.h> 50 #include <sys/utsname.h> 51 #include <sys/ktrace.h> 52 53 #include <dlfcn.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "debug.h" 64 #include "rtld.h" 65 #include "libmap.h" 66 #include "paths.h" 67 #include "rtld_tls.h" 68 #include "rtld_printf.h" 69 #include "rtld_malloc.h" 70 #include "rtld_utrace.h" 71 #include "notes.h" 72 #include "rtld_libc.h" 73 74 /* Types. */ 75 typedef void (*func_ptr_type)(void); 76 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 77 78 79 /* Variables that cannot be static: */ 80 extern struct r_debug r_debug; /* For GDB */ 81 extern int _thread_autoinit_dummy_decl; 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 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 254 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 255 256 257 int npagesizes; 258 static int osreldate; 259 size_t *pagesizes; 260 261 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 262 static int max_stack_flags; 263 264 /* 265 * Global declarations normally provided by crt1. The dynamic linker is 266 * not built with crt1, so we have to provide them ourselves. 267 */ 268 char *__progname; 269 char **environ; 270 271 /* 272 * Used to pass argc, argv to init functions. 273 */ 274 int main_argc; 275 char **main_argv; 276 277 /* 278 * Globals to control TLS allocation. 279 */ 280 size_t tls_last_offset; /* Static TLS offset of last module */ 281 size_t tls_last_size; /* Static TLS size of last module */ 282 size_t tls_static_space; /* Static TLS space allocated */ 283 static size_t tls_static_max_align; 284 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 285 int tls_max_index = 1; /* Largest module index allocated */ 286 287 static bool ld_library_path_rpath = false; 288 289 /* 290 * Globals for path names, and such 291 */ 292 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 293 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 294 const char *ld_path_rtld = _PATH_RTLD; 295 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 296 const char *ld_env_prefix = LD_; 297 298 static void (*rtld_exit_ptr)(void); 299 300 /* 301 * Fill in a DoneList with an allocation large enough to hold all of 302 * the currently-loaded objects. Keep this as a macro since it calls 303 * alloca and we want that to occur within the scope of the caller. 304 */ 305 #define donelist_init(dlp) \ 306 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 307 assert((dlp)->objs != NULL), \ 308 (dlp)->num_alloc = obj_count, \ 309 (dlp)->num_used = 0) 310 311 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 312 if (ld_utrace != NULL) \ 313 ld_utrace_log(e, h, mb, ms, r, n); \ 314 } while (0) 315 316 static void 317 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 318 int refcnt, const char *name) 319 { 320 struct utrace_rtld ut; 321 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 322 323 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 324 ut.event = event; 325 ut.handle = handle; 326 ut.mapbase = mapbase; 327 ut.mapsize = mapsize; 328 ut.refcnt = refcnt; 329 bzero(ut.name, sizeof(ut.name)); 330 if (name) 331 strlcpy(ut.name, name, sizeof(ut.name)); 332 utrace(&ut, sizeof(ut)); 333 } 334 335 #ifdef RTLD_VARIANT_ENV_NAMES 336 /* 337 * construct the env variable based on the type of binary that's 338 * running. 339 */ 340 static inline const char * 341 _LD(const char *var) 342 { 343 static char buffer[128]; 344 345 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 346 strlcat(buffer, var, sizeof(buffer)); 347 return (buffer); 348 } 349 #else 350 #define _LD(x) LD_ x 351 #endif 352 353 /* 354 * Main entry point for dynamic linking. The first argument is the 355 * stack pointer. The stack is expected to be laid out as described 356 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 357 * Specifically, the stack pointer points to a word containing 358 * ARGC. Following that in the stack is a null-terminated sequence 359 * of pointers to argument strings. Then comes a null-terminated 360 * sequence of pointers to environment strings. Finally, there is a 361 * sequence of "auxiliary vector" entries. 362 * 363 * The second argument points to a place to store the dynamic linker's 364 * exit procedure pointer and the third to a place to store the main 365 * program's object. 366 * 367 * The return value is the main program's entry point. 368 */ 369 func_ptr_type 370 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 371 { 372 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 373 Objlist_Entry *entry; 374 Obj_Entry *last_interposer, *obj, *preload_tail; 375 const Elf_Phdr *phdr; 376 Objlist initlist; 377 RtldLockState lockstate; 378 struct stat st; 379 Elf_Addr *argcp; 380 char **argv, **env, **envp, *kexecpath, *library_path_rpath; 381 const char *argv0; 382 caddr_t imgentry; 383 char buf[MAXPATHLEN]; 384 int argc, fd, i, phnum, rtld_argc; 385 bool dir_enable, explicit_fd, search_in_path; 386 387 /* 388 * On entry, the dynamic linker itself has not been relocated yet. 389 * Be very careful not to reference any global data until after 390 * init_rtld has returned. It is OK to reference file-scope statics 391 * and string constants, and to call static and global functions. 392 */ 393 394 /* Find the auxiliary vector on the stack. */ 395 argcp = sp; 396 argc = *sp++; 397 argv = (char **) sp; 398 sp += argc + 1; /* Skip over arguments and NULL terminator */ 399 env = (char **) sp; 400 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 401 ; 402 aux = (Elf_Auxinfo *) sp; 403 404 /* Digest the auxiliary vector. */ 405 for (i = 0; i < AT_COUNT; i++) 406 aux_info[i] = NULL; 407 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 408 if (auxp->a_type < AT_COUNT) 409 aux_info[auxp->a_type] = auxp; 410 } 411 412 /* Initialize and relocate ourselves. */ 413 assert(aux_info[AT_BASE] != NULL); 414 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 415 416 __progname = obj_rtld.path; 417 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 418 environ = env; 419 main_argc = argc; 420 main_argv = argv; 421 422 trust = !issetugid(); 423 424 md_abi_variant_hook(aux_info); 425 426 fd = -1; 427 if (aux_info[AT_EXECFD] != NULL) { 428 fd = aux_info[AT_EXECFD]->a_un.a_val; 429 } else { 430 assert(aux_info[AT_PHDR] != NULL); 431 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 432 if (phdr == obj_rtld.phdr) { 433 if (!trust) { 434 _rtld_error("Tainted process refusing to run binary %s", 435 argv0); 436 rtld_die(); 437 } 438 dbg("opening main program in direct exec mode"); 439 if (argc >= 2) { 440 rtld_argc = parse_args(argv, argc, &search_in_path, &fd); 441 argv0 = argv[rtld_argc]; 442 explicit_fd = (fd != -1); 443 if (!explicit_fd) 444 fd = open_binary_fd(argv0, search_in_path); 445 if (fstat(fd, &st) == -1) { 446 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 447 explicit_fd ? "user-provided descriptor" : argv0, 448 rtld_strerror(errno)); 449 rtld_die(); 450 } 451 452 /* 453 * Rough emulation of the permission checks done by 454 * execve(2), only Unix DACs are checked, ACLs are 455 * ignored. Preserve the semantic of disabling owner 456 * to execute if owner x bit is cleared, even if 457 * others x bit is enabled. 458 * mmap(2) does not allow to mmap with PROT_EXEC if 459 * binary' file comes from noexec mount. We cannot 460 * set a text reference on the binary. 461 */ 462 dir_enable = false; 463 if (st.st_uid == geteuid()) { 464 if ((st.st_mode & S_IXUSR) != 0) 465 dir_enable = true; 466 } else if (st.st_gid == getegid()) { 467 if ((st.st_mode & S_IXGRP) != 0) 468 dir_enable = true; 469 } else if ((st.st_mode & S_IXOTH) != 0) { 470 dir_enable = true; 471 } 472 if (!dir_enable) { 473 _rtld_error("No execute permission for binary %s", 474 argv0); 475 rtld_die(); 476 } 477 478 /* 479 * For direct exec mode, argv[0] is the interpreter 480 * name, we must remove it and shift arguments left 481 * before invoking binary main. Since stack layout 482 * places environment pointers and aux vectors right 483 * after the terminating NULL, we must shift 484 * environment and aux as well. 485 */ 486 main_argc = argc - rtld_argc; 487 for (i = 0; i <= main_argc; i++) 488 argv[i] = argv[i + rtld_argc]; 489 *argcp -= rtld_argc; 490 environ = env = envp = argv + main_argc + 1; 491 do { 492 *envp = *(envp + rtld_argc); 493 envp++; 494 } while (*envp != NULL); 495 aux = auxp = (Elf_Auxinfo *)envp; 496 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 497 for (;; auxp++, auxpf++) { 498 *auxp = *auxpf; 499 if (auxp->a_type == AT_NULL) 500 break; 501 } 502 /* Since the auxiliary vector has moved, redigest it. */ 503 for (i = 0; i < AT_COUNT; i++) 504 aux_info[i] = NULL; 505 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 506 if (auxp->a_type < AT_COUNT) 507 aux_info[auxp->a_type] = auxp; 508 } 509 } else { 510 _rtld_error("No binary"); 511 rtld_die(); 512 } 513 } 514 } 515 516 ld_bind_now = getenv(_LD("BIND_NOW")); 517 518 /* 519 * If the process is tainted, then we un-set the dangerous environment 520 * variables. The process will be marked as tainted until setuid(2) 521 * is called. If any child process calls setuid(2) we do not want any 522 * future processes to honor the potentially un-safe variables. 523 */ 524 if (!trust) { 525 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 526 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 527 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 528 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 529 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) { 530 _rtld_error("environment corrupt; aborting"); 531 rtld_die(); 532 } 533 } 534 ld_debug = getenv(_LD("DEBUG")); 535 if (ld_bind_now == NULL) 536 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 537 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 538 libmap_override = getenv(_LD("LIBMAP")); 539 ld_library_path = getenv(_LD("LIBRARY_PATH")); 540 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 541 ld_preload = getenv(_LD("PRELOAD")); 542 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 543 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 544 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 545 if (library_path_rpath != NULL) { 546 if (library_path_rpath[0] == 'y' || 547 library_path_rpath[0] == 'Y' || 548 library_path_rpath[0] == '1') 549 ld_library_path_rpath = true; 550 else 551 ld_library_path_rpath = false; 552 } 553 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 554 (ld_library_path != NULL) || (ld_preload != NULL) || 555 (ld_elf_hints_path != NULL) || ld_loadfltr; 556 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 557 ld_utrace = getenv(_LD("UTRACE")); 558 559 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 560 ld_elf_hints_path = ld_elf_hints_default; 561 562 if (ld_debug != NULL && *ld_debug != '\0') 563 debug = 1; 564 dbg("%s is initialized, base address = %p", __progname, 565 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 566 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 567 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 568 569 dbg("initializing thread locks"); 570 lockdflt_init(); 571 572 /* 573 * Load the main program, or process its program header if it is 574 * already loaded. 575 */ 576 if (fd != -1) { /* Load the main program. */ 577 dbg("loading main program"); 578 obj_main = map_object(fd, argv0, NULL); 579 close(fd); 580 if (obj_main == NULL) 581 rtld_die(); 582 max_stack_flags = obj_main->stack_flags; 583 } else { /* Main program already loaded. */ 584 dbg("processing main program's program header"); 585 assert(aux_info[AT_PHDR] != NULL); 586 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 587 assert(aux_info[AT_PHNUM] != NULL); 588 phnum = aux_info[AT_PHNUM]->a_un.a_val; 589 assert(aux_info[AT_PHENT] != NULL); 590 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 591 assert(aux_info[AT_ENTRY] != NULL); 592 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 593 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 594 rtld_die(); 595 } 596 597 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 598 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 599 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 600 if (kexecpath[0] == '/') 601 obj_main->path = kexecpath; 602 else if (getcwd(buf, sizeof(buf)) == NULL || 603 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 604 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 605 obj_main->path = xstrdup(argv0); 606 else 607 obj_main->path = xstrdup(buf); 608 } else { 609 dbg("No AT_EXECPATH or direct exec"); 610 obj_main->path = xstrdup(argv0); 611 } 612 dbg("obj_main path %s", obj_main->path); 613 obj_main->mainprog = true; 614 615 if (aux_info[AT_STACKPROT] != NULL && 616 aux_info[AT_STACKPROT]->a_un.a_val != 0) 617 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 618 619 #ifndef COMPAT_32BIT 620 /* 621 * Get the actual dynamic linker pathname from the executable if 622 * possible. (It should always be possible.) That ensures that 623 * gdb will find the right dynamic linker even if a non-standard 624 * one is being used. 625 */ 626 if (obj_main->interp != NULL && 627 strcmp(obj_main->interp, obj_rtld.path) != 0) { 628 free(obj_rtld.path); 629 obj_rtld.path = xstrdup(obj_main->interp); 630 __progname = obj_rtld.path; 631 } 632 #endif 633 634 digest_dynamic(obj_main, 0); 635 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 636 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 637 obj_main->dynsymcount); 638 639 linkmap_add(obj_main); 640 linkmap_add(&obj_rtld); 641 642 /* Link the main program into the list of objects. */ 643 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 644 obj_count++; 645 obj_loads++; 646 647 /* Initialize a fake symbol for resolving undefined weak references. */ 648 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 649 sym_zero.st_shndx = SHN_UNDEF; 650 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 651 652 if (!libmap_disable) 653 libmap_disable = (bool)lm_init(libmap_override); 654 655 dbg("loading LD_PRELOAD libraries"); 656 if (load_preload_objects() == -1) 657 rtld_die(); 658 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 659 660 dbg("loading needed objects"); 661 if (load_needed_objects(obj_main, 0) == -1) 662 rtld_die(); 663 664 /* Make a list of all objects loaded at startup. */ 665 last_interposer = obj_main; 666 TAILQ_FOREACH(obj, &obj_list, next) { 667 if (obj->marker) 668 continue; 669 if (obj->z_interpose && obj != obj_main) { 670 objlist_put_after(&list_main, last_interposer, obj); 671 last_interposer = obj; 672 } else { 673 objlist_push_tail(&list_main, obj); 674 } 675 obj->refcount++; 676 } 677 678 dbg("checking for required versions"); 679 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 680 rtld_die(); 681 682 if (ld_tracing) { /* We're done */ 683 trace_loaded_objects(obj_main); 684 exit(0); 685 } 686 687 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 688 dump_relocations(obj_main); 689 exit (0); 690 } 691 692 /* 693 * Processing tls relocations requires having the tls offsets 694 * initialized. Prepare offsets before starting initial 695 * relocation processing. 696 */ 697 dbg("initializing initial thread local storage offsets"); 698 STAILQ_FOREACH(entry, &list_main, link) { 699 /* 700 * Allocate all the initial objects out of the static TLS 701 * block even if they didn't ask for it. 702 */ 703 allocate_tls_offset(entry->obj); 704 } 705 706 if (relocate_objects(obj_main, 707 ld_bind_now != NULL && *ld_bind_now != '\0', 708 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 709 rtld_die(); 710 711 dbg("doing copy relocations"); 712 if (do_copy_relocations(obj_main) == -1) 713 rtld_die(); 714 715 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 716 dump_relocations(obj_main); 717 exit (0); 718 } 719 720 ifunc_init(aux); 721 722 /* 723 * Setup TLS for main thread. This must be done after the 724 * relocations are processed, since tls initialization section 725 * might be the subject for relocations. 726 */ 727 dbg("initializing initial thread local storage"); 728 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 729 730 dbg("initializing key program variables"); 731 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 732 set_program_var("environ", env); 733 set_program_var("__elf_aux_vector", aux); 734 735 /* Make a list of init functions to call. */ 736 objlist_init(&initlist); 737 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 738 preload_tail, &initlist); 739 740 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 741 742 map_stacks_exec(NULL); 743 744 if (!obj_main->crt_no_init) { 745 /* 746 * Make sure we don't call the main program's init and fini 747 * functions for binaries linked with old crt1 which calls 748 * _init itself. 749 */ 750 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 751 obj_main->preinit_array = obj_main->init_array = 752 obj_main->fini_array = (Elf_Addr)NULL; 753 } 754 755 /* 756 * Execute MD initializers required before we call the objects' 757 * init functions. 758 */ 759 pre_init(); 760 761 wlock_acquire(rtld_bind_lock, &lockstate); 762 763 dbg("resolving ifuncs"); 764 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 765 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 766 rtld_die(); 767 768 rtld_exit_ptr = rtld_exit; 769 if (obj_main->crt_no_init) 770 preinit_main(); 771 objlist_call_init(&initlist, &lockstate); 772 _r_debug_postinit(&obj_main->linkmap); 773 objlist_clear(&initlist); 774 dbg("loading filtees"); 775 TAILQ_FOREACH(obj, &obj_list, next) { 776 if (obj->marker) 777 continue; 778 if (ld_loadfltr || obj->z_loadfltr) 779 load_filtees(obj, 0, &lockstate); 780 } 781 782 dbg("enforcing main obj relro"); 783 if (obj_enforce_relro(obj_main) == -1) 784 rtld_die(); 785 786 lock_release(rtld_bind_lock, &lockstate); 787 788 dbg("transferring control to program entry point = %p", obj_main->entry); 789 790 /* Return the exit procedure and the program entry point. */ 791 *exit_proc = rtld_exit_ptr; 792 *objp = obj_main; 793 return (func_ptr_type) obj_main->entry; 794 } 795 796 void * 797 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 798 { 799 void *ptr; 800 Elf_Addr target; 801 802 ptr = (void *)make_function_pointer(def, obj); 803 target = call_ifunc_resolver(ptr); 804 return ((void *)target); 805 } 806 807 /* 808 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 809 * Changes to this function should be applied there as well. 810 */ 811 Elf_Addr 812 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 813 { 814 const Elf_Rel *rel; 815 const Elf_Sym *def; 816 const Obj_Entry *defobj; 817 Elf_Addr *where; 818 Elf_Addr target; 819 RtldLockState lockstate; 820 821 rlock_acquire(rtld_bind_lock, &lockstate); 822 if (sigsetjmp(lockstate.env, 0) != 0) 823 lock_upgrade(rtld_bind_lock, &lockstate); 824 if (obj->pltrel) 825 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 826 else 827 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 828 829 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 830 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 831 NULL, &lockstate); 832 if (def == NULL) 833 rtld_die(); 834 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 835 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 836 else 837 target = (Elf_Addr)(defobj->relocbase + def->st_value); 838 839 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 840 defobj->strtab + def->st_name, basename(obj->path), 841 (void *)target, basename(defobj->path)); 842 843 /* 844 * Write the new contents for the jmpslot. Note that depending on 845 * architecture, the value which we need to return back to the 846 * lazy binding trampoline may or may not be the target 847 * address. The value returned from reloc_jmpslot() is the value 848 * that the trampoline needs. 849 */ 850 target = reloc_jmpslot(where, target, defobj, obj, rel); 851 lock_release(rtld_bind_lock, &lockstate); 852 return target; 853 } 854 855 /* 856 * Error reporting function. Use it like printf. If formats the message 857 * into a buffer, and sets things up so that the next call to dlerror() 858 * will return the message. 859 */ 860 void 861 _rtld_error(const char *fmt, ...) 862 { 863 static char buf[512]; 864 va_list ap; 865 866 va_start(ap, fmt); 867 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 868 error_message = buf; 869 va_end(ap); 870 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message); 871 } 872 873 /* 874 * Return a dynamically-allocated copy of the current error message, if any. 875 */ 876 static char * 877 errmsg_save(void) 878 { 879 return error_message == NULL ? NULL : xstrdup(error_message); 880 } 881 882 /* 883 * Restore the current error message from a copy which was previously saved 884 * by errmsg_save(). The copy is freed. 885 */ 886 static void 887 errmsg_restore(char *saved_msg) 888 { 889 if (saved_msg == NULL) 890 error_message = NULL; 891 else { 892 _rtld_error("%s", saved_msg); 893 free(saved_msg); 894 } 895 } 896 897 static const char * 898 basename(const char *name) 899 { 900 const char *p = strrchr(name, '/'); 901 return p != NULL ? p + 1 : name; 902 } 903 904 static struct utsname uts; 905 906 static char * 907 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 908 const char *subst, bool may_free) 909 { 910 char *p, *p1, *res, *resp; 911 int subst_len, kw_len, subst_count, old_len, new_len; 912 913 kw_len = strlen(kw); 914 915 /* 916 * First, count the number of the keyword occurrences, to 917 * preallocate the final string. 918 */ 919 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 920 p1 = strstr(p, kw); 921 if (p1 == NULL) 922 break; 923 } 924 925 /* 926 * If the keyword is not found, just return. 927 * 928 * Return non-substituted string if resolution failed. We 929 * cannot do anything more reasonable, the failure mode of the 930 * caller is unresolved library anyway. 931 */ 932 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 933 return (may_free ? real : xstrdup(real)); 934 if (obj != NULL) 935 subst = obj->origin_path; 936 937 /* 938 * There is indeed something to substitute. Calculate the 939 * length of the resulting string, and allocate it. 940 */ 941 subst_len = strlen(subst); 942 old_len = strlen(real); 943 new_len = old_len + (subst_len - kw_len) * subst_count; 944 res = xmalloc(new_len + 1); 945 946 /* 947 * Now, execute the substitution loop. 948 */ 949 for (p = real, resp = res, *resp = '\0';;) { 950 p1 = strstr(p, kw); 951 if (p1 != NULL) { 952 /* Copy the prefix before keyword. */ 953 memcpy(resp, p, p1 - p); 954 resp += p1 - p; 955 /* Keyword replacement. */ 956 memcpy(resp, subst, subst_len); 957 resp += subst_len; 958 *resp = '\0'; 959 p = p1 + kw_len; 960 } else 961 break; 962 } 963 964 /* Copy to the end of string and finish. */ 965 strcat(resp, p); 966 if (may_free) 967 free(real); 968 return (res); 969 } 970 971 static char * 972 origin_subst(Obj_Entry *obj, const char *real) 973 { 974 char *res1, *res2, *res3, *res4; 975 976 if (obj == NULL || !trust) 977 return (xstrdup(real)); 978 if (uts.sysname[0] == '\0') { 979 if (uname(&uts) != 0) { 980 _rtld_error("utsname failed: %d", errno); 981 return (NULL); 982 } 983 } 984 /* __DECONST is safe here since without may_free real is unchanged */ 985 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 986 false); 987 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 988 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 989 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 990 return (res4); 991 } 992 993 void 994 rtld_die(void) 995 { 996 const char *msg = dlerror(); 997 998 if (msg == NULL) 999 msg = "Fatal error"; 1000 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1001 rtld_fdputstr(STDERR_FILENO, msg); 1002 rtld_fdputchar(STDERR_FILENO, '\n'); 1003 _exit(1); 1004 } 1005 1006 /* 1007 * Process a shared object's DYNAMIC section, and save the important 1008 * information in its Obj_Entry structure. 1009 */ 1010 static void 1011 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1012 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1013 { 1014 const Elf_Dyn *dynp; 1015 Needed_Entry **needed_tail = &obj->needed; 1016 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1017 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1018 const Elf_Hashelt *hashtab; 1019 const Elf32_Word *hashval; 1020 Elf32_Word bkt, nmaskwords; 1021 int bloom_size32; 1022 int plttype = DT_REL; 1023 1024 *dyn_rpath = NULL; 1025 *dyn_soname = NULL; 1026 *dyn_runpath = NULL; 1027 1028 obj->bind_now = false; 1029 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 1030 switch (dynp->d_tag) { 1031 1032 case DT_REL: 1033 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1034 break; 1035 1036 case DT_RELSZ: 1037 obj->relsize = dynp->d_un.d_val; 1038 break; 1039 1040 case DT_RELENT: 1041 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1042 break; 1043 1044 case DT_JMPREL: 1045 obj->pltrel = (const Elf_Rel *) 1046 (obj->relocbase + dynp->d_un.d_ptr); 1047 break; 1048 1049 case DT_PLTRELSZ: 1050 obj->pltrelsize = dynp->d_un.d_val; 1051 break; 1052 1053 case DT_RELA: 1054 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1055 break; 1056 1057 case DT_RELASZ: 1058 obj->relasize = dynp->d_un.d_val; 1059 break; 1060 1061 case DT_RELAENT: 1062 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1063 break; 1064 1065 case DT_PLTREL: 1066 plttype = dynp->d_un.d_val; 1067 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1068 break; 1069 1070 case DT_SYMTAB: 1071 obj->symtab = (const Elf_Sym *) 1072 (obj->relocbase + dynp->d_un.d_ptr); 1073 break; 1074 1075 case DT_SYMENT: 1076 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1077 break; 1078 1079 case DT_STRTAB: 1080 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1081 break; 1082 1083 case DT_STRSZ: 1084 obj->strsize = dynp->d_un.d_val; 1085 break; 1086 1087 case DT_VERNEED: 1088 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1089 dynp->d_un.d_val); 1090 break; 1091 1092 case DT_VERNEEDNUM: 1093 obj->verneednum = dynp->d_un.d_val; 1094 break; 1095 1096 case DT_VERDEF: 1097 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1098 dynp->d_un.d_val); 1099 break; 1100 1101 case DT_VERDEFNUM: 1102 obj->verdefnum = dynp->d_un.d_val; 1103 break; 1104 1105 case DT_VERSYM: 1106 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1107 dynp->d_un.d_val); 1108 break; 1109 1110 case DT_HASH: 1111 { 1112 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1113 dynp->d_un.d_ptr); 1114 obj->nbuckets = hashtab[0]; 1115 obj->nchains = hashtab[1]; 1116 obj->buckets = hashtab + 2; 1117 obj->chains = obj->buckets + obj->nbuckets; 1118 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1119 obj->buckets != NULL; 1120 } 1121 break; 1122 1123 case DT_GNU_HASH: 1124 { 1125 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1126 dynp->d_un.d_ptr); 1127 obj->nbuckets_gnu = hashtab[0]; 1128 obj->symndx_gnu = hashtab[1]; 1129 nmaskwords = hashtab[2]; 1130 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1131 obj->maskwords_bm_gnu = nmaskwords - 1; 1132 obj->shift2_gnu = hashtab[3]; 1133 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1134 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1135 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1136 obj->symndx_gnu; 1137 /* Number of bitmask words is required to be power of 2 */ 1138 obj->valid_hash_gnu = powerof2(nmaskwords) && 1139 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1140 } 1141 break; 1142 1143 case DT_NEEDED: 1144 if (!obj->rtld) { 1145 Needed_Entry *nep = NEW(Needed_Entry); 1146 nep->name = dynp->d_un.d_val; 1147 nep->obj = NULL; 1148 nep->next = NULL; 1149 1150 *needed_tail = nep; 1151 needed_tail = &nep->next; 1152 } 1153 break; 1154 1155 case DT_FILTER: 1156 if (!obj->rtld) { 1157 Needed_Entry *nep = NEW(Needed_Entry); 1158 nep->name = dynp->d_un.d_val; 1159 nep->obj = NULL; 1160 nep->next = NULL; 1161 1162 *needed_filtees_tail = nep; 1163 needed_filtees_tail = &nep->next; 1164 } 1165 break; 1166 1167 case DT_AUXILIARY: 1168 if (!obj->rtld) { 1169 Needed_Entry *nep = NEW(Needed_Entry); 1170 nep->name = dynp->d_un.d_val; 1171 nep->obj = NULL; 1172 nep->next = NULL; 1173 1174 *needed_aux_filtees_tail = nep; 1175 needed_aux_filtees_tail = &nep->next; 1176 } 1177 break; 1178 1179 case DT_PLTGOT: 1180 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1181 break; 1182 1183 case DT_TEXTREL: 1184 obj->textrel = true; 1185 break; 1186 1187 case DT_SYMBOLIC: 1188 obj->symbolic = true; 1189 break; 1190 1191 case DT_RPATH: 1192 /* 1193 * We have to wait until later to process this, because we 1194 * might not have gotten the address of the string table yet. 1195 */ 1196 *dyn_rpath = dynp; 1197 break; 1198 1199 case DT_SONAME: 1200 *dyn_soname = dynp; 1201 break; 1202 1203 case DT_RUNPATH: 1204 *dyn_runpath = dynp; 1205 break; 1206 1207 case DT_INIT: 1208 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1209 break; 1210 1211 case DT_PREINIT_ARRAY: 1212 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1213 break; 1214 1215 case DT_PREINIT_ARRAYSZ: 1216 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1217 break; 1218 1219 case DT_INIT_ARRAY: 1220 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1221 break; 1222 1223 case DT_INIT_ARRAYSZ: 1224 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1225 break; 1226 1227 case DT_FINI: 1228 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1229 break; 1230 1231 case DT_FINI_ARRAY: 1232 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1233 break; 1234 1235 case DT_FINI_ARRAYSZ: 1236 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1237 break; 1238 1239 /* 1240 * Don't process DT_DEBUG on MIPS as the dynamic section 1241 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1242 */ 1243 1244 #ifndef __mips__ 1245 case DT_DEBUG: 1246 if (!early) 1247 dbg("Filling in DT_DEBUG entry"); 1248 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1249 break; 1250 #endif 1251 1252 case DT_FLAGS: 1253 if (dynp->d_un.d_val & DF_ORIGIN) 1254 obj->z_origin = true; 1255 if (dynp->d_un.d_val & DF_SYMBOLIC) 1256 obj->symbolic = true; 1257 if (dynp->d_un.d_val & DF_TEXTREL) 1258 obj->textrel = true; 1259 if (dynp->d_un.d_val & DF_BIND_NOW) 1260 obj->bind_now = true; 1261 if (dynp->d_un.d_val & DF_STATIC_TLS) 1262 obj->static_tls = true; 1263 break; 1264 #ifdef __mips__ 1265 case DT_MIPS_LOCAL_GOTNO: 1266 obj->local_gotno = dynp->d_un.d_val; 1267 break; 1268 1269 case DT_MIPS_SYMTABNO: 1270 obj->symtabno = dynp->d_un.d_val; 1271 break; 1272 1273 case DT_MIPS_GOTSYM: 1274 obj->gotsym = dynp->d_un.d_val; 1275 break; 1276 1277 case DT_MIPS_RLD_MAP: 1278 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1279 break; 1280 1281 case DT_MIPS_RLD_MAP_REL: 1282 // The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map 1283 // section relative to the address of the tag itself. 1284 *((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) = 1285 (Elf_Addr) &r_debug; 1286 break; 1287 1288 case DT_MIPS_PLTGOT: 1289 obj->mips_pltgot = (Elf_Addr *)(obj->relocbase + 1290 dynp->d_un.d_ptr); 1291 break; 1292 1293 #endif 1294 1295 #ifdef __powerpc__ 1296 #ifdef __powerpc64__ 1297 case DT_PPC64_GLINK: 1298 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1299 break; 1300 #else 1301 case DT_PPC_GOT: 1302 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1303 break; 1304 #endif 1305 #endif 1306 1307 case DT_FLAGS_1: 1308 if (dynp->d_un.d_val & DF_1_NOOPEN) 1309 obj->z_noopen = true; 1310 if (dynp->d_un.d_val & DF_1_ORIGIN) 1311 obj->z_origin = true; 1312 if (dynp->d_un.d_val & DF_1_GLOBAL) 1313 obj->z_global = true; 1314 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1315 obj->bind_now = true; 1316 if (dynp->d_un.d_val & DF_1_NODELETE) 1317 obj->z_nodelete = true; 1318 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1319 obj->z_loadfltr = true; 1320 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1321 obj->z_interpose = true; 1322 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1323 obj->z_nodeflib = true; 1324 break; 1325 1326 default: 1327 if (!early) { 1328 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1329 (long)dynp->d_tag); 1330 } 1331 break; 1332 } 1333 } 1334 1335 obj->traced = false; 1336 1337 if (plttype == DT_RELA) { 1338 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1339 obj->pltrel = NULL; 1340 obj->pltrelasize = obj->pltrelsize; 1341 obj->pltrelsize = 0; 1342 } 1343 1344 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1345 if (obj->valid_hash_sysv) 1346 obj->dynsymcount = obj->nchains; 1347 else if (obj->valid_hash_gnu) { 1348 obj->dynsymcount = 0; 1349 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1350 if (obj->buckets_gnu[bkt] == 0) 1351 continue; 1352 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1353 do 1354 obj->dynsymcount++; 1355 while ((*hashval++ & 1u) == 0); 1356 } 1357 obj->dynsymcount += obj->symndx_gnu; 1358 } 1359 } 1360 1361 static bool 1362 obj_resolve_origin(Obj_Entry *obj) 1363 { 1364 1365 if (obj->origin_path != NULL) 1366 return (true); 1367 obj->origin_path = xmalloc(PATH_MAX); 1368 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1369 } 1370 1371 static void 1372 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1373 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1374 { 1375 1376 if (obj->z_origin && !obj_resolve_origin(obj)) 1377 rtld_die(); 1378 1379 if (dyn_runpath != NULL) { 1380 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1381 obj->runpath = origin_subst(obj, obj->runpath); 1382 } else if (dyn_rpath != NULL) { 1383 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1384 obj->rpath = origin_subst(obj, obj->rpath); 1385 } 1386 if (dyn_soname != NULL) 1387 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1388 } 1389 1390 static void 1391 digest_dynamic(Obj_Entry *obj, int early) 1392 { 1393 const Elf_Dyn *dyn_rpath; 1394 const Elf_Dyn *dyn_soname; 1395 const Elf_Dyn *dyn_runpath; 1396 1397 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1398 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1399 } 1400 1401 /* 1402 * Process a shared object's program header. This is used only for the 1403 * main program, when the kernel has already loaded the main program 1404 * into memory before calling the dynamic linker. It creates and 1405 * returns an Obj_Entry structure. 1406 */ 1407 static Obj_Entry * 1408 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1409 { 1410 Obj_Entry *obj; 1411 const Elf_Phdr *phlimit = phdr + phnum; 1412 const Elf_Phdr *ph; 1413 Elf_Addr note_start, note_end; 1414 int nsegs = 0; 1415 1416 obj = obj_new(); 1417 for (ph = phdr; ph < phlimit; ph++) { 1418 if (ph->p_type != PT_PHDR) 1419 continue; 1420 1421 obj->phdr = phdr; 1422 obj->phsize = ph->p_memsz; 1423 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1424 break; 1425 } 1426 1427 obj->stack_flags = PF_X | PF_R | PF_W; 1428 1429 for (ph = phdr; ph < phlimit; ph++) { 1430 switch (ph->p_type) { 1431 1432 case PT_INTERP: 1433 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1434 break; 1435 1436 case PT_LOAD: 1437 if (nsegs == 0) { /* First load segment */ 1438 obj->vaddrbase = trunc_page(ph->p_vaddr); 1439 obj->mapbase = obj->vaddrbase + obj->relocbase; 1440 } else { /* Last load segment */ 1441 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1442 obj->vaddrbase; 1443 } 1444 nsegs++; 1445 break; 1446 1447 case PT_DYNAMIC: 1448 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1449 break; 1450 1451 case PT_TLS: 1452 obj->tlsindex = 1; 1453 obj->tlssize = ph->p_memsz; 1454 obj->tlsalign = ph->p_align; 1455 obj->tlsinitsize = ph->p_filesz; 1456 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1457 break; 1458 1459 case PT_GNU_STACK: 1460 obj->stack_flags = ph->p_flags; 1461 break; 1462 1463 case PT_GNU_RELRO: 1464 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1465 obj->relro_size = round_page(ph->p_memsz); 1466 break; 1467 1468 case PT_NOTE: 1469 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1470 note_end = note_start + ph->p_filesz; 1471 digest_notes(obj, note_start, note_end); 1472 break; 1473 } 1474 } 1475 if (nsegs < 1) { 1476 _rtld_error("%s: too few PT_LOAD segments", path); 1477 return NULL; 1478 } 1479 1480 obj->entry = entry; 1481 return obj; 1482 } 1483 1484 void 1485 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1486 { 1487 const Elf_Note *note; 1488 const char *note_name; 1489 uintptr_t p; 1490 1491 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1492 note = (const Elf_Note *)((const char *)(note + 1) + 1493 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1494 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1495 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1496 note->n_descsz != sizeof(int32_t)) 1497 continue; 1498 if (note->n_type != NT_FREEBSD_ABI_TAG && 1499 note->n_type != NT_FREEBSD_FEATURE_CTL && 1500 note->n_type != NT_FREEBSD_NOINIT_TAG) 1501 continue; 1502 note_name = (const char *)(note + 1); 1503 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1504 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1505 continue; 1506 switch (note->n_type) { 1507 case NT_FREEBSD_ABI_TAG: 1508 /* FreeBSD osrel note */ 1509 p = (uintptr_t)(note + 1); 1510 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1511 obj->osrel = *(const int32_t *)(p); 1512 dbg("note osrel %d", obj->osrel); 1513 break; 1514 case NT_FREEBSD_FEATURE_CTL: 1515 /* FreeBSD ABI feature control note */ 1516 p = (uintptr_t)(note + 1); 1517 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1518 obj->fctl0 = *(const uint32_t *)(p); 1519 dbg("note fctl0 %#x", obj->fctl0); 1520 break; 1521 case NT_FREEBSD_NOINIT_TAG: 1522 /* FreeBSD 'crt does not call init' note */ 1523 obj->crt_no_init = true; 1524 dbg("note crt_no_init"); 1525 break; 1526 } 1527 } 1528 } 1529 1530 static Obj_Entry * 1531 dlcheck(void *handle) 1532 { 1533 Obj_Entry *obj; 1534 1535 TAILQ_FOREACH(obj, &obj_list, next) { 1536 if (obj == (Obj_Entry *) handle) 1537 break; 1538 } 1539 1540 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1541 _rtld_error("Invalid shared object handle %p", handle); 1542 return NULL; 1543 } 1544 return obj; 1545 } 1546 1547 /* 1548 * If the given object is already in the donelist, return true. Otherwise 1549 * add the object to the list and return false. 1550 */ 1551 static bool 1552 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1553 { 1554 unsigned int i; 1555 1556 for (i = 0; i < dlp->num_used; i++) 1557 if (dlp->objs[i] == obj) 1558 return true; 1559 /* 1560 * Our donelist allocation should always be sufficient. But if 1561 * our threads locking isn't working properly, more shared objects 1562 * could have been loaded since we allocated the list. That should 1563 * never happen, but we'll handle it properly just in case it does. 1564 */ 1565 if (dlp->num_used < dlp->num_alloc) 1566 dlp->objs[dlp->num_used++] = obj; 1567 return false; 1568 } 1569 1570 /* 1571 * Hash function for symbol table lookup. Don't even think about changing 1572 * this. It is specified by the System V ABI. 1573 */ 1574 unsigned long 1575 elf_hash(const char *name) 1576 { 1577 const unsigned char *p = (const unsigned char *) name; 1578 unsigned long h = 0; 1579 unsigned long g; 1580 1581 while (*p != '\0') { 1582 h = (h << 4) + *p++; 1583 if ((g = h & 0xf0000000) != 0) 1584 h ^= g >> 24; 1585 h &= ~g; 1586 } 1587 return h; 1588 } 1589 1590 /* 1591 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1592 * unsigned in case it's implemented with a wider type. 1593 */ 1594 static uint32_t 1595 gnu_hash(const char *s) 1596 { 1597 uint32_t h; 1598 unsigned char c; 1599 1600 h = 5381; 1601 for (c = *s; c != '\0'; c = *++s) 1602 h = h * 33 + c; 1603 return (h & 0xffffffff); 1604 } 1605 1606 1607 /* 1608 * Find the library with the given name, and return its full pathname. 1609 * The returned string is dynamically allocated. Generates an error 1610 * message and returns NULL if the library cannot be found. 1611 * 1612 * If the second argument is non-NULL, then it refers to an already- 1613 * loaded shared object, whose library search path will be searched. 1614 * 1615 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1616 * descriptor (which is close-on-exec) will be passed out via the third 1617 * argument. 1618 * 1619 * The search order is: 1620 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1621 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1622 * LD_LIBRARY_PATH 1623 * DT_RUNPATH in the referencing file 1624 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1625 * from list) 1626 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1627 * 1628 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1629 */ 1630 static char * 1631 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1632 { 1633 char *pathname, *refobj_path; 1634 const char *name; 1635 bool nodeflib, objgiven; 1636 1637 objgiven = refobj != NULL; 1638 1639 if (libmap_disable || !objgiven || 1640 (name = lm_find(refobj->path, xname)) == NULL) 1641 name = xname; 1642 1643 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1644 if (name[0] != '/' && !trust) { 1645 _rtld_error("Absolute pathname required " 1646 "for shared object \"%s\"", name); 1647 return (NULL); 1648 } 1649 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1650 __DECONST(char *, name))); 1651 } 1652 1653 dbg(" Searching for \"%s\"", name); 1654 refobj_path = objgiven ? refobj->path : NULL; 1655 1656 /* 1657 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1658 * back to pre-conforming behaviour if user requested so with 1659 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1660 * nodeflib. 1661 */ 1662 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1663 pathname = search_library_path(name, ld_library_path, 1664 refobj_path, fdp); 1665 if (pathname != NULL) 1666 return (pathname); 1667 if (refobj != NULL) { 1668 pathname = search_library_path(name, refobj->rpath, 1669 refobj_path, fdp); 1670 if (pathname != NULL) 1671 return (pathname); 1672 } 1673 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1674 if (pathname != NULL) 1675 return (pathname); 1676 pathname = search_library_path(name, gethints(false), 1677 refobj_path, fdp); 1678 if (pathname != NULL) 1679 return (pathname); 1680 pathname = search_library_path(name, ld_standard_library_path, 1681 refobj_path, fdp); 1682 if (pathname != NULL) 1683 return (pathname); 1684 } else { 1685 nodeflib = objgiven ? refobj->z_nodeflib : false; 1686 if (objgiven) { 1687 pathname = search_library_path(name, refobj->rpath, 1688 refobj->path, fdp); 1689 if (pathname != NULL) 1690 return (pathname); 1691 } 1692 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1693 pathname = search_library_path(name, obj_main->rpath, 1694 refobj_path, fdp); 1695 if (pathname != NULL) 1696 return (pathname); 1697 } 1698 pathname = search_library_path(name, ld_library_path, 1699 refobj_path, fdp); 1700 if (pathname != NULL) 1701 return (pathname); 1702 if (objgiven) { 1703 pathname = search_library_path(name, refobj->runpath, 1704 refobj_path, fdp); 1705 if (pathname != NULL) 1706 return (pathname); 1707 } 1708 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1709 if (pathname != NULL) 1710 return (pathname); 1711 pathname = search_library_path(name, gethints(nodeflib), 1712 refobj_path, fdp); 1713 if (pathname != NULL) 1714 return (pathname); 1715 if (objgiven && !nodeflib) { 1716 pathname = search_library_path(name, 1717 ld_standard_library_path, refobj_path, fdp); 1718 if (pathname != NULL) 1719 return (pathname); 1720 } 1721 } 1722 1723 if (objgiven && refobj->path != NULL) { 1724 _rtld_error("Shared object \"%s\" not found, " 1725 "required by \"%s\"", name, basename(refobj->path)); 1726 } else { 1727 _rtld_error("Shared object \"%s\" not found", name); 1728 } 1729 return (NULL); 1730 } 1731 1732 /* 1733 * Given a symbol number in a referencing object, find the corresponding 1734 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1735 * no definition was found. Returns a pointer to the Obj_Entry of the 1736 * defining object via the reference parameter DEFOBJ_OUT. 1737 */ 1738 const Elf_Sym * 1739 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1740 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1741 RtldLockState *lockstate) 1742 { 1743 const Elf_Sym *ref; 1744 const Elf_Sym *def; 1745 const Obj_Entry *defobj; 1746 const Ver_Entry *ve; 1747 SymLook req; 1748 const char *name; 1749 int res; 1750 1751 /* 1752 * If we have already found this symbol, get the information from 1753 * the cache. 1754 */ 1755 if (symnum >= refobj->dynsymcount) 1756 return NULL; /* Bad object */ 1757 if (cache != NULL && cache[symnum].sym != NULL) { 1758 *defobj_out = cache[symnum].obj; 1759 return cache[symnum].sym; 1760 } 1761 1762 ref = refobj->symtab + symnum; 1763 name = refobj->strtab + ref->st_name; 1764 def = NULL; 1765 defobj = NULL; 1766 ve = NULL; 1767 1768 /* 1769 * We don't have to do a full scale lookup if the symbol is local. 1770 * We know it will bind to the instance in this load module; to 1771 * which we already have a pointer (ie ref). By not doing a lookup, 1772 * we not only improve performance, but it also avoids unresolvable 1773 * symbols when local symbols are not in the hash table. This has 1774 * been seen with the ia64 toolchain. 1775 */ 1776 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1777 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1778 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1779 symnum); 1780 } 1781 symlook_init(&req, name); 1782 req.flags = flags; 1783 ve = req.ventry = fetch_ventry(refobj, symnum); 1784 req.lockstate = lockstate; 1785 res = symlook_default(&req, refobj); 1786 if (res == 0) { 1787 def = req.sym_out; 1788 defobj = req.defobj_out; 1789 } 1790 } else { 1791 def = ref; 1792 defobj = refobj; 1793 } 1794 1795 /* 1796 * If we found no definition and the reference is weak, treat the 1797 * symbol as having the value zero. 1798 */ 1799 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1800 def = &sym_zero; 1801 defobj = obj_main; 1802 } 1803 1804 if (def != NULL) { 1805 *defobj_out = defobj; 1806 /* Record the information in the cache to avoid subsequent lookups. */ 1807 if (cache != NULL) { 1808 cache[symnum].sym = def; 1809 cache[symnum].obj = defobj; 1810 } 1811 } else { 1812 if (refobj != &obj_rtld) 1813 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1814 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1815 } 1816 return def; 1817 } 1818 1819 /* 1820 * Return the search path from the ldconfig hints file, reading it if 1821 * necessary. If nostdlib is true, then the default search paths are 1822 * not added to result. 1823 * 1824 * Returns NULL if there are problems with the hints file, 1825 * or if the search path there is empty. 1826 */ 1827 static const char * 1828 gethints(bool nostdlib) 1829 { 1830 static char *filtered_path; 1831 static const char *hints; 1832 static struct elfhints_hdr hdr; 1833 struct fill_search_info_args sargs, hargs; 1834 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1835 struct dl_serpath *SLPpath, *hintpath; 1836 char *p; 1837 struct stat hint_stat; 1838 unsigned int SLPndx, hintndx, fndx, fcount; 1839 int fd; 1840 size_t flen; 1841 uint32_t dl; 1842 bool skip; 1843 1844 /* First call, read the hints file */ 1845 if (hints == NULL) { 1846 /* Keep from trying again in case the hints file is bad. */ 1847 hints = ""; 1848 1849 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1850 return (NULL); 1851 1852 /* 1853 * Check of hdr.dirlistlen value against type limit 1854 * intends to pacify static analyzers. Further 1855 * paranoia leads to checks that dirlist is fully 1856 * contained in the file range. 1857 */ 1858 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1859 hdr.magic != ELFHINTS_MAGIC || 1860 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1861 fstat(fd, &hint_stat) == -1) { 1862 cleanup1: 1863 close(fd); 1864 hdr.dirlistlen = 0; 1865 return (NULL); 1866 } 1867 dl = hdr.strtab; 1868 if (dl + hdr.dirlist < dl) 1869 goto cleanup1; 1870 dl += hdr.dirlist; 1871 if (dl + hdr.dirlistlen < dl) 1872 goto cleanup1; 1873 dl += hdr.dirlistlen; 1874 if (dl > hint_stat.st_size) 1875 goto cleanup1; 1876 p = xmalloc(hdr.dirlistlen + 1); 1877 if (pread(fd, p, hdr.dirlistlen + 1, 1878 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1879 p[hdr.dirlistlen] != '\0') { 1880 free(p); 1881 goto cleanup1; 1882 } 1883 hints = p; 1884 close(fd); 1885 } 1886 1887 /* 1888 * If caller agreed to receive list which includes the default 1889 * paths, we are done. Otherwise, if we still did not 1890 * calculated filtered result, do it now. 1891 */ 1892 if (!nostdlib) 1893 return (hints[0] != '\0' ? hints : NULL); 1894 if (filtered_path != NULL) 1895 goto filt_ret; 1896 1897 /* 1898 * Obtain the list of all configured search paths, and the 1899 * list of the default paths. 1900 * 1901 * First estimate the size of the results. 1902 */ 1903 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1904 smeta.dls_cnt = 0; 1905 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1906 hmeta.dls_cnt = 0; 1907 1908 sargs.request = RTLD_DI_SERINFOSIZE; 1909 sargs.serinfo = &smeta; 1910 hargs.request = RTLD_DI_SERINFOSIZE; 1911 hargs.serinfo = &hmeta; 1912 1913 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1914 &sargs); 1915 path_enumerate(hints, fill_search_info, NULL, &hargs); 1916 1917 SLPinfo = xmalloc(smeta.dls_size); 1918 hintinfo = xmalloc(hmeta.dls_size); 1919 1920 /* 1921 * Next fetch both sets of paths. 1922 */ 1923 sargs.request = RTLD_DI_SERINFO; 1924 sargs.serinfo = SLPinfo; 1925 sargs.serpath = &SLPinfo->dls_serpath[0]; 1926 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1927 1928 hargs.request = RTLD_DI_SERINFO; 1929 hargs.serinfo = hintinfo; 1930 hargs.serpath = &hintinfo->dls_serpath[0]; 1931 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1932 1933 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1934 &sargs); 1935 path_enumerate(hints, fill_search_info, NULL, &hargs); 1936 1937 /* 1938 * Now calculate the difference between two sets, by excluding 1939 * standard paths from the full set. 1940 */ 1941 fndx = 0; 1942 fcount = 0; 1943 filtered_path = xmalloc(hdr.dirlistlen + 1); 1944 hintpath = &hintinfo->dls_serpath[0]; 1945 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1946 skip = false; 1947 SLPpath = &SLPinfo->dls_serpath[0]; 1948 /* 1949 * Check each standard path against current. 1950 */ 1951 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1952 /* matched, skip the path */ 1953 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1954 skip = true; 1955 break; 1956 } 1957 } 1958 if (skip) 1959 continue; 1960 /* 1961 * Not matched against any standard path, add the path 1962 * to result. Separate consequtive paths with ':'. 1963 */ 1964 if (fcount > 0) { 1965 filtered_path[fndx] = ':'; 1966 fndx++; 1967 } 1968 fcount++; 1969 flen = strlen(hintpath->dls_name); 1970 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1971 fndx += flen; 1972 } 1973 filtered_path[fndx] = '\0'; 1974 1975 free(SLPinfo); 1976 free(hintinfo); 1977 1978 filt_ret: 1979 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1980 } 1981 1982 static void 1983 init_dag(Obj_Entry *root) 1984 { 1985 const Needed_Entry *needed; 1986 const Objlist_Entry *elm; 1987 DoneList donelist; 1988 1989 if (root->dag_inited) 1990 return; 1991 donelist_init(&donelist); 1992 1993 /* Root object belongs to own DAG. */ 1994 objlist_push_tail(&root->dldags, root); 1995 objlist_push_tail(&root->dagmembers, root); 1996 donelist_check(&donelist, root); 1997 1998 /* 1999 * Add dependencies of root object to DAG in breadth order 2000 * by exploiting the fact that each new object get added 2001 * to the tail of the dagmembers list. 2002 */ 2003 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2004 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2005 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2006 continue; 2007 objlist_push_tail(&needed->obj->dldags, root); 2008 objlist_push_tail(&root->dagmembers, needed->obj); 2009 } 2010 } 2011 root->dag_inited = true; 2012 } 2013 2014 static void 2015 init_marker(Obj_Entry *marker) 2016 { 2017 2018 bzero(marker, sizeof(*marker)); 2019 marker->marker = true; 2020 } 2021 2022 Obj_Entry * 2023 globallist_curr(const Obj_Entry *obj) 2024 { 2025 2026 for (;;) { 2027 if (obj == NULL) 2028 return (NULL); 2029 if (!obj->marker) 2030 return (__DECONST(Obj_Entry *, obj)); 2031 obj = TAILQ_PREV(obj, obj_entry_q, next); 2032 } 2033 } 2034 2035 Obj_Entry * 2036 globallist_next(const Obj_Entry *obj) 2037 { 2038 2039 for (;;) { 2040 obj = TAILQ_NEXT(obj, next); 2041 if (obj == NULL) 2042 return (NULL); 2043 if (!obj->marker) 2044 return (__DECONST(Obj_Entry *, obj)); 2045 } 2046 } 2047 2048 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2049 static void 2050 hold_object(Obj_Entry *obj) 2051 { 2052 2053 obj->holdcount++; 2054 } 2055 2056 static void 2057 unhold_object(Obj_Entry *obj) 2058 { 2059 2060 assert(obj->holdcount > 0); 2061 if (--obj->holdcount == 0 && obj->unholdfree) 2062 release_object(obj); 2063 } 2064 2065 static void 2066 process_z(Obj_Entry *root) 2067 { 2068 const Objlist_Entry *elm; 2069 Obj_Entry *obj; 2070 2071 /* 2072 * Walk over object DAG and process every dependent object 2073 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2074 * to grow their own DAG. 2075 * 2076 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2077 * symlook_global() to work. 2078 * 2079 * For DF_1_NODELETE, the DAG should have its reference upped. 2080 */ 2081 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2082 obj = elm->obj; 2083 if (obj == NULL) 2084 continue; 2085 if (obj->z_nodelete && !obj->ref_nodel) { 2086 dbg("obj %s -z nodelete", obj->path); 2087 init_dag(obj); 2088 ref_dag(obj); 2089 obj->ref_nodel = true; 2090 } 2091 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2092 dbg("obj %s -z global", obj->path); 2093 objlist_push_tail(&list_global, obj); 2094 init_dag(obj); 2095 } 2096 } 2097 } 2098 /* 2099 * Initialize the dynamic linker. The argument is the address at which 2100 * the dynamic linker has been mapped into memory. The primary task of 2101 * this function is to relocate the dynamic linker. 2102 */ 2103 static void 2104 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2105 { 2106 Obj_Entry objtmp; /* Temporary rtld object */ 2107 const Elf_Ehdr *ehdr; 2108 const Elf_Dyn *dyn_rpath; 2109 const Elf_Dyn *dyn_soname; 2110 const Elf_Dyn *dyn_runpath; 2111 2112 #ifdef RTLD_INIT_PAGESIZES_EARLY 2113 /* The page size is required by the dynamic memory allocator. */ 2114 init_pagesizes(aux_info); 2115 #endif 2116 2117 /* 2118 * Conjure up an Obj_Entry structure for the dynamic linker. 2119 * 2120 * The "path" member can't be initialized yet because string constants 2121 * cannot yet be accessed. Below we will set it correctly. 2122 */ 2123 memset(&objtmp, 0, sizeof(objtmp)); 2124 objtmp.path = NULL; 2125 objtmp.rtld = true; 2126 objtmp.mapbase = mapbase; 2127 #ifdef PIC 2128 objtmp.relocbase = mapbase; 2129 #endif 2130 2131 objtmp.dynamic = rtld_dynamic(&objtmp); 2132 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2133 assert(objtmp.needed == NULL); 2134 #if !defined(__mips__) 2135 /* MIPS has a bogus DT_TEXTREL. */ 2136 assert(!objtmp.textrel); 2137 #endif 2138 /* 2139 * Temporarily put the dynamic linker entry into the object list, so 2140 * that symbols can be found. 2141 */ 2142 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2143 2144 ehdr = (Elf_Ehdr *)mapbase; 2145 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2146 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2147 2148 /* Initialize the object list. */ 2149 TAILQ_INIT(&obj_list); 2150 2151 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2152 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2153 2154 #ifndef RTLD_INIT_PAGESIZES_EARLY 2155 /* The page size is required by the dynamic memory allocator. */ 2156 init_pagesizes(aux_info); 2157 #endif 2158 2159 if (aux_info[AT_OSRELDATE] != NULL) 2160 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2161 2162 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2163 2164 /* Replace the path with a dynamically allocated copy. */ 2165 obj_rtld.path = xstrdup(ld_path_rtld); 2166 2167 r_debug.r_brk = r_debug_state; 2168 r_debug.r_state = RT_CONSISTENT; 2169 } 2170 2171 /* 2172 * Retrieve the array of supported page sizes. The kernel provides the page 2173 * sizes in increasing order. 2174 */ 2175 static void 2176 init_pagesizes(Elf_Auxinfo **aux_info) 2177 { 2178 static size_t psa[MAXPAGESIZES]; 2179 int mib[2]; 2180 size_t len, size; 2181 2182 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2183 NULL) { 2184 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2185 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2186 } else { 2187 len = 2; 2188 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2189 size = sizeof(psa); 2190 else { 2191 /* As a fallback, retrieve the base page size. */ 2192 size = sizeof(psa[0]); 2193 if (aux_info[AT_PAGESZ] != NULL) { 2194 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2195 goto psa_filled; 2196 } else { 2197 mib[0] = CTL_HW; 2198 mib[1] = HW_PAGESIZE; 2199 len = 2; 2200 } 2201 } 2202 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2203 _rtld_error("sysctl for hw.pagesize(s) failed"); 2204 rtld_die(); 2205 } 2206 psa_filled: 2207 pagesizes = psa; 2208 } 2209 npagesizes = size / sizeof(pagesizes[0]); 2210 /* Discard any invalid entries at the end of the array. */ 2211 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2212 npagesizes--; 2213 } 2214 2215 /* 2216 * Add the init functions from a needed object list (and its recursive 2217 * needed objects) to "list". This is not used directly; it is a helper 2218 * function for initlist_add_objects(). The write lock must be held 2219 * when this function is called. 2220 */ 2221 static void 2222 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2223 { 2224 /* Recursively process the successor needed objects. */ 2225 if (needed->next != NULL) 2226 initlist_add_neededs(needed->next, list); 2227 2228 /* Process the current needed object. */ 2229 if (needed->obj != NULL) 2230 initlist_add_objects(needed->obj, needed->obj, list); 2231 } 2232 2233 /* 2234 * Scan all of the DAGs rooted in the range of objects from "obj" to 2235 * "tail" and add their init functions to "list". This recurses over 2236 * the DAGs and ensure the proper init ordering such that each object's 2237 * needed libraries are initialized before the object itself. At the 2238 * same time, this function adds the objects to the global finalization 2239 * list "list_fini" in the opposite order. The write lock must be 2240 * held when this function is called. 2241 */ 2242 static void 2243 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2244 { 2245 Obj_Entry *nobj; 2246 2247 if (obj->init_scanned || obj->init_done) 2248 return; 2249 obj->init_scanned = true; 2250 2251 /* Recursively process the successor objects. */ 2252 nobj = globallist_next(obj); 2253 if (nobj != NULL && obj != tail) 2254 initlist_add_objects(nobj, tail, list); 2255 2256 /* Recursively process the needed objects. */ 2257 if (obj->needed != NULL) 2258 initlist_add_neededs(obj->needed, list); 2259 if (obj->needed_filtees != NULL) 2260 initlist_add_neededs(obj->needed_filtees, list); 2261 if (obj->needed_aux_filtees != NULL) 2262 initlist_add_neededs(obj->needed_aux_filtees, list); 2263 2264 /* Add the object to the init list. */ 2265 objlist_push_tail(list, obj); 2266 2267 /* Add the object to the global fini list in the reverse order. */ 2268 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2269 && !obj->on_fini_list) { 2270 objlist_push_head(&list_fini, obj); 2271 obj->on_fini_list = true; 2272 } 2273 } 2274 2275 #ifndef FPTR_TARGET 2276 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2277 #endif 2278 2279 static void 2280 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2281 { 2282 Needed_Entry *needed, *needed1; 2283 2284 for (needed = n; needed != NULL; needed = needed->next) { 2285 if (needed->obj != NULL) { 2286 dlclose_locked(needed->obj, lockstate); 2287 needed->obj = NULL; 2288 } 2289 } 2290 for (needed = n; needed != NULL; needed = needed1) { 2291 needed1 = needed->next; 2292 free(needed); 2293 } 2294 } 2295 2296 static void 2297 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2298 { 2299 2300 free_needed_filtees(obj->needed_filtees, lockstate); 2301 obj->needed_filtees = NULL; 2302 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2303 obj->needed_aux_filtees = NULL; 2304 obj->filtees_loaded = false; 2305 } 2306 2307 static void 2308 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2309 RtldLockState *lockstate) 2310 { 2311 2312 for (; needed != NULL; needed = needed->next) { 2313 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2314 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2315 RTLD_LOCAL, lockstate); 2316 } 2317 } 2318 2319 static void 2320 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2321 { 2322 2323 lock_restart_for_upgrade(lockstate); 2324 if (!obj->filtees_loaded) { 2325 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2326 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2327 obj->filtees_loaded = true; 2328 } 2329 } 2330 2331 static int 2332 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2333 { 2334 Obj_Entry *obj1; 2335 2336 for (; needed != NULL; needed = needed->next) { 2337 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2338 flags & ~RTLD_LO_NOLOAD); 2339 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2340 return (-1); 2341 } 2342 return (0); 2343 } 2344 2345 /* 2346 * Given a shared object, traverse its list of needed objects, and load 2347 * each of them. Returns 0 on success. Generates an error message and 2348 * returns -1 on failure. 2349 */ 2350 static int 2351 load_needed_objects(Obj_Entry *first, int flags) 2352 { 2353 Obj_Entry *obj; 2354 2355 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2356 if (obj->marker) 2357 continue; 2358 if (process_needed(obj, obj->needed, flags) == -1) 2359 return (-1); 2360 } 2361 return (0); 2362 } 2363 2364 static int 2365 load_preload_objects(void) 2366 { 2367 char *p = ld_preload; 2368 Obj_Entry *obj; 2369 static const char delim[] = " \t:;"; 2370 2371 if (p == NULL) 2372 return 0; 2373 2374 p += strspn(p, delim); 2375 while (*p != '\0') { 2376 size_t len = strcspn(p, delim); 2377 char savech; 2378 2379 savech = p[len]; 2380 p[len] = '\0'; 2381 obj = load_object(p, -1, NULL, 0); 2382 if (obj == NULL) 2383 return -1; /* XXX - cleanup */ 2384 obj->z_interpose = true; 2385 p[len] = savech; 2386 p += len; 2387 p += strspn(p, delim); 2388 } 2389 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2390 return 0; 2391 } 2392 2393 static const char * 2394 printable_path(const char *path) 2395 { 2396 2397 return (path == NULL ? "<unknown>" : path); 2398 } 2399 2400 /* 2401 * Load a shared object into memory, if it is not already loaded. The 2402 * object may be specified by name or by user-supplied file descriptor 2403 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2404 * duplicate is. 2405 * 2406 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2407 * on failure. 2408 */ 2409 static Obj_Entry * 2410 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2411 { 2412 Obj_Entry *obj; 2413 int fd; 2414 struct stat sb; 2415 char *path; 2416 2417 fd = -1; 2418 if (name != NULL) { 2419 TAILQ_FOREACH(obj, &obj_list, next) { 2420 if (obj->marker || obj->doomed) 2421 continue; 2422 if (object_match_name(obj, name)) 2423 return (obj); 2424 } 2425 2426 path = find_library(name, refobj, &fd); 2427 if (path == NULL) 2428 return (NULL); 2429 } else 2430 path = NULL; 2431 2432 if (fd >= 0) { 2433 /* 2434 * search_library_pathfds() opens a fresh file descriptor for the 2435 * library, so there is no need to dup(). 2436 */ 2437 } else if (fd_u == -1) { 2438 /* 2439 * If we didn't find a match by pathname, or the name is not 2440 * supplied, open the file and check again by device and inode. 2441 * This avoids false mismatches caused by multiple links or ".." 2442 * in pathnames. 2443 * 2444 * To avoid a race, we open the file and use fstat() rather than 2445 * using stat(). 2446 */ 2447 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2448 _rtld_error("Cannot open \"%s\"", path); 2449 free(path); 2450 return (NULL); 2451 } 2452 } else { 2453 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2454 if (fd == -1) { 2455 _rtld_error("Cannot dup fd"); 2456 free(path); 2457 return (NULL); 2458 } 2459 } 2460 if (fstat(fd, &sb) == -1) { 2461 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2462 close(fd); 2463 free(path); 2464 return NULL; 2465 } 2466 TAILQ_FOREACH(obj, &obj_list, next) { 2467 if (obj->marker || obj->doomed) 2468 continue; 2469 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2470 break; 2471 } 2472 if (obj != NULL && name != NULL) { 2473 object_add_name(obj, name); 2474 free(path); 2475 close(fd); 2476 return obj; 2477 } 2478 if (flags & RTLD_LO_NOLOAD) { 2479 free(path); 2480 close(fd); 2481 return (NULL); 2482 } 2483 2484 /* First use of this object, so we must map it in */ 2485 obj = do_load_object(fd, name, path, &sb, flags); 2486 if (obj == NULL) 2487 free(path); 2488 close(fd); 2489 2490 return obj; 2491 } 2492 2493 static Obj_Entry * 2494 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2495 int flags) 2496 { 2497 Obj_Entry *obj; 2498 struct statfs fs; 2499 2500 /* 2501 * but first, make sure that environment variables haven't been 2502 * used to circumvent the noexec flag on a filesystem. 2503 */ 2504 if (dangerous_ld_env) { 2505 if (fstatfs(fd, &fs) != 0) { 2506 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2507 return NULL; 2508 } 2509 if (fs.f_flags & MNT_NOEXEC) { 2510 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2511 return NULL; 2512 } 2513 } 2514 dbg("loading \"%s\"", printable_path(path)); 2515 obj = map_object(fd, printable_path(path), sbp); 2516 if (obj == NULL) 2517 return NULL; 2518 2519 /* 2520 * If DT_SONAME is present in the object, digest_dynamic2 already 2521 * added it to the object names. 2522 */ 2523 if (name != NULL) 2524 object_add_name(obj, name); 2525 obj->path = path; 2526 digest_dynamic(obj, 0); 2527 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2528 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2529 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2530 RTLD_LO_DLOPEN) { 2531 dbg("refusing to load non-loadable \"%s\"", obj->path); 2532 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2533 munmap(obj->mapbase, obj->mapsize); 2534 obj_free(obj); 2535 return (NULL); 2536 } 2537 2538 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2539 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2540 obj_count++; 2541 obj_loads++; 2542 linkmap_add(obj); /* for GDB & dlinfo() */ 2543 max_stack_flags |= obj->stack_flags; 2544 2545 dbg(" %p .. %p: %s", obj->mapbase, 2546 obj->mapbase + obj->mapsize - 1, obj->path); 2547 if (obj->textrel) 2548 dbg(" WARNING: %s has impure text", obj->path); 2549 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2550 obj->path); 2551 2552 return obj; 2553 } 2554 2555 static Obj_Entry * 2556 obj_from_addr(const void *addr) 2557 { 2558 Obj_Entry *obj; 2559 2560 TAILQ_FOREACH(obj, &obj_list, next) { 2561 if (obj->marker) 2562 continue; 2563 if (addr < (void *) obj->mapbase) 2564 continue; 2565 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2566 return obj; 2567 } 2568 return NULL; 2569 } 2570 2571 static void 2572 preinit_main(void) 2573 { 2574 Elf_Addr *preinit_addr; 2575 int index; 2576 2577 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2578 if (preinit_addr == NULL) 2579 return; 2580 2581 for (index = 0; index < obj_main->preinit_array_num; index++) { 2582 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2583 dbg("calling preinit function for %s at %p", obj_main->path, 2584 (void *)preinit_addr[index]); 2585 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2586 0, 0, obj_main->path); 2587 call_init_pointer(obj_main, preinit_addr[index]); 2588 } 2589 } 2590 } 2591 2592 /* 2593 * Call the finalization functions for each of the objects in "list" 2594 * belonging to the DAG of "root" and referenced once. If NULL "root" 2595 * is specified, every finalization function will be called regardless 2596 * of the reference count and the list elements won't be freed. All of 2597 * the objects are expected to have non-NULL fini functions. 2598 */ 2599 static void 2600 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2601 { 2602 Objlist_Entry *elm; 2603 char *saved_msg; 2604 Elf_Addr *fini_addr; 2605 int index; 2606 2607 assert(root == NULL || root->refcount == 1); 2608 2609 if (root != NULL) 2610 root->doomed = true; 2611 2612 /* 2613 * Preserve the current error message since a fini function might 2614 * call into the dynamic linker and overwrite it. 2615 */ 2616 saved_msg = errmsg_save(); 2617 do { 2618 STAILQ_FOREACH(elm, list, link) { 2619 if (root != NULL && (elm->obj->refcount != 1 || 2620 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2621 continue; 2622 /* Remove object from fini list to prevent recursive invocation. */ 2623 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2624 /* Ensure that new references cannot be acquired. */ 2625 elm->obj->doomed = true; 2626 2627 hold_object(elm->obj); 2628 lock_release(rtld_bind_lock, lockstate); 2629 /* 2630 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2631 * When this happens, DT_FINI_ARRAY is processed first. 2632 */ 2633 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2634 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2635 for (index = elm->obj->fini_array_num - 1; index >= 0; 2636 index--) { 2637 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2638 dbg("calling fini function for %s at %p", 2639 elm->obj->path, (void *)fini_addr[index]); 2640 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2641 (void *)fini_addr[index], 0, 0, elm->obj->path); 2642 call_initfini_pointer(elm->obj, fini_addr[index]); 2643 } 2644 } 2645 } 2646 if (elm->obj->fini != (Elf_Addr)NULL) { 2647 dbg("calling fini function for %s at %p", elm->obj->path, 2648 (void *)elm->obj->fini); 2649 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2650 0, 0, elm->obj->path); 2651 call_initfini_pointer(elm->obj, elm->obj->fini); 2652 } 2653 wlock_acquire(rtld_bind_lock, lockstate); 2654 unhold_object(elm->obj); 2655 /* No need to free anything if process is going down. */ 2656 if (root != NULL) 2657 free(elm); 2658 /* 2659 * We must restart the list traversal after every fini call 2660 * because a dlclose() call from the fini function or from 2661 * another thread might have modified the reference counts. 2662 */ 2663 break; 2664 } 2665 } while (elm != NULL); 2666 errmsg_restore(saved_msg); 2667 } 2668 2669 /* 2670 * Call the initialization functions for each of the objects in 2671 * "list". All of the objects are expected to have non-NULL init 2672 * functions. 2673 */ 2674 static void 2675 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2676 { 2677 Objlist_Entry *elm; 2678 Obj_Entry *obj; 2679 char *saved_msg; 2680 Elf_Addr *init_addr; 2681 void (*reg)(void (*)(void)); 2682 int index; 2683 2684 /* 2685 * Clean init_scanned flag so that objects can be rechecked and 2686 * possibly initialized earlier if any of vectors called below 2687 * cause the change by using dlopen. 2688 */ 2689 TAILQ_FOREACH(obj, &obj_list, next) { 2690 if (obj->marker) 2691 continue; 2692 obj->init_scanned = false; 2693 } 2694 2695 /* 2696 * Preserve the current error message since an init function might 2697 * call into the dynamic linker and overwrite it. 2698 */ 2699 saved_msg = errmsg_save(); 2700 STAILQ_FOREACH(elm, list, link) { 2701 if (elm->obj->init_done) /* Initialized early. */ 2702 continue; 2703 /* 2704 * Race: other thread might try to use this object before current 2705 * one completes the initialization. Not much can be done here 2706 * without better locking. 2707 */ 2708 elm->obj->init_done = true; 2709 hold_object(elm->obj); 2710 reg = NULL; 2711 if (elm->obj == obj_main && obj_main->crt_no_init) { 2712 reg = (void (*)(void (*)(void)))get_program_var_addr( 2713 "__libc_atexit", lockstate); 2714 } 2715 lock_release(rtld_bind_lock, lockstate); 2716 if (reg != NULL) { 2717 reg(rtld_exit); 2718 rtld_exit_ptr = rtld_nop_exit; 2719 } 2720 2721 /* 2722 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2723 * When this happens, DT_INIT is processed first. 2724 */ 2725 if (elm->obj->init != (Elf_Addr)NULL) { 2726 dbg("calling init function for %s at %p", elm->obj->path, 2727 (void *)elm->obj->init); 2728 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2729 0, 0, elm->obj->path); 2730 call_initfini_pointer(elm->obj, elm->obj->init); 2731 } 2732 init_addr = (Elf_Addr *)elm->obj->init_array; 2733 if (init_addr != NULL) { 2734 for (index = 0; index < elm->obj->init_array_num; index++) { 2735 if (init_addr[index] != 0 && init_addr[index] != 1) { 2736 dbg("calling init function for %s at %p", elm->obj->path, 2737 (void *)init_addr[index]); 2738 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2739 (void *)init_addr[index], 0, 0, elm->obj->path); 2740 call_init_pointer(elm->obj, init_addr[index]); 2741 } 2742 } 2743 } 2744 wlock_acquire(rtld_bind_lock, lockstate); 2745 unhold_object(elm->obj); 2746 } 2747 errmsg_restore(saved_msg); 2748 } 2749 2750 static void 2751 objlist_clear(Objlist *list) 2752 { 2753 Objlist_Entry *elm; 2754 2755 while (!STAILQ_EMPTY(list)) { 2756 elm = STAILQ_FIRST(list); 2757 STAILQ_REMOVE_HEAD(list, link); 2758 free(elm); 2759 } 2760 } 2761 2762 static Objlist_Entry * 2763 objlist_find(Objlist *list, const Obj_Entry *obj) 2764 { 2765 Objlist_Entry *elm; 2766 2767 STAILQ_FOREACH(elm, list, link) 2768 if (elm->obj == obj) 2769 return elm; 2770 return NULL; 2771 } 2772 2773 static void 2774 objlist_init(Objlist *list) 2775 { 2776 STAILQ_INIT(list); 2777 } 2778 2779 static void 2780 objlist_push_head(Objlist *list, Obj_Entry *obj) 2781 { 2782 Objlist_Entry *elm; 2783 2784 elm = NEW(Objlist_Entry); 2785 elm->obj = obj; 2786 STAILQ_INSERT_HEAD(list, elm, link); 2787 } 2788 2789 static void 2790 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2791 { 2792 Objlist_Entry *elm; 2793 2794 elm = NEW(Objlist_Entry); 2795 elm->obj = obj; 2796 STAILQ_INSERT_TAIL(list, elm, link); 2797 } 2798 2799 static void 2800 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2801 { 2802 Objlist_Entry *elm, *listelm; 2803 2804 STAILQ_FOREACH(listelm, list, link) { 2805 if (listelm->obj == listobj) 2806 break; 2807 } 2808 elm = NEW(Objlist_Entry); 2809 elm->obj = obj; 2810 if (listelm != NULL) 2811 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2812 else 2813 STAILQ_INSERT_TAIL(list, elm, link); 2814 } 2815 2816 static void 2817 objlist_remove(Objlist *list, Obj_Entry *obj) 2818 { 2819 Objlist_Entry *elm; 2820 2821 if ((elm = objlist_find(list, obj)) != NULL) { 2822 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2823 free(elm); 2824 } 2825 } 2826 2827 /* 2828 * Relocate dag rooted in the specified object. 2829 * Returns 0 on success, or -1 on failure. 2830 */ 2831 2832 static int 2833 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2834 int flags, RtldLockState *lockstate) 2835 { 2836 Objlist_Entry *elm; 2837 int error; 2838 2839 error = 0; 2840 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2841 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2842 lockstate); 2843 if (error == -1) 2844 break; 2845 } 2846 return (error); 2847 } 2848 2849 /* 2850 * Prepare for, or clean after, relocating an object marked with 2851 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 2852 * segments are remapped read-write. After relocations are done, the 2853 * segment's permissions are returned back to the modes specified in 2854 * the phdrs. If any relocation happened, or always for wired 2855 * program, COW is triggered. 2856 */ 2857 static int 2858 reloc_textrel_prot(Obj_Entry *obj, bool before) 2859 { 2860 const Elf_Phdr *ph; 2861 void *base; 2862 size_t l, sz; 2863 int prot; 2864 2865 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 2866 l--, ph++) { 2867 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 2868 continue; 2869 base = obj->relocbase + trunc_page(ph->p_vaddr); 2870 sz = round_page(ph->p_vaddr + ph->p_filesz) - 2871 trunc_page(ph->p_vaddr); 2872 prot = convert_prot(ph->p_flags) | (before ? PROT_WRITE : 0); 2873 if (mprotect(base, sz, prot) == -1) { 2874 _rtld_error("%s: Cannot write-%sable text segment: %s", 2875 obj->path, before ? "en" : "dis", 2876 rtld_strerror(errno)); 2877 return (-1); 2878 } 2879 } 2880 return (0); 2881 } 2882 2883 /* 2884 * Relocate single object. 2885 * Returns 0 on success, or -1 on failure. 2886 */ 2887 static int 2888 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2889 int flags, RtldLockState *lockstate) 2890 { 2891 2892 if (obj->relocated) 2893 return (0); 2894 obj->relocated = true; 2895 if (obj != rtldobj) 2896 dbg("relocating \"%s\"", obj->path); 2897 2898 if (obj->symtab == NULL || obj->strtab == NULL || 2899 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2900 _rtld_error("%s: Shared object has no run-time symbol table", 2901 obj->path); 2902 return (-1); 2903 } 2904 2905 /* There are relocations to the write-protected text segment. */ 2906 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 2907 return (-1); 2908 2909 /* Process the non-PLT non-IFUNC relocations. */ 2910 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2911 return (-1); 2912 2913 /* Re-protected the text segment. */ 2914 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 2915 return (-1); 2916 2917 /* Set the special PLT or GOT entries. */ 2918 init_pltgot(obj); 2919 2920 /* Process the PLT relocations. */ 2921 if (reloc_plt(obj, flags, lockstate) == -1) 2922 return (-1); 2923 /* Relocate the jump slots if we are doing immediate binding. */ 2924 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 2925 lockstate) == -1) 2926 return (-1); 2927 2928 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 2929 return (-1); 2930 2931 /* 2932 * Set up the magic number and version in the Obj_Entry. These 2933 * were checked in the crt1.o from the original ElfKit, so we 2934 * set them for backward compatibility. 2935 */ 2936 obj->magic = RTLD_MAGIC; 2937 obj->version = RTLD_VERSION; 2938 2939 return (0); 2940 } 2941 2942 /* 2943 * Relocate newly-loaded shared objects. The argument is a pointer to 2944 * the Obj_Entry for the first such object. All objects from the first 2945 * to the end of the list of objects are relocated. Returns 0 on success, 2946 * or -1 on failure. 2947 */ 2948 static int 2949 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2950 int flags, RtldLockState *lockstate) 2951 { 2952 Obj_Entry *obj; 2953 int error; 2954 2955 for (error = 0, obj = first; obj != NULL; 2956 obj = TAILQ_NEXT(obj, next)) { 2957 if (obj->marker) 2958 continue; 2959 error = relocate_object(obj, bind_now, rtldobj, flags, 2960 lockstate); 2961 if (error == -1) 2962 break; 2963 } 2964 return (error); 2965 } 2966 2967 /* 2968 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2969 * referencing STT_GNU_IFUNC symbols is postponed till the other 2970 * relocations are done. The indirect functions specified as 2971 * ifunc are allowed to call other symbols, so we need to have 2972 * objects relocated before asking for resolution from indirects. 2973 * 2974 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2975 * instead of the usual lazy handling of PLT slots. It is 2976 * consistent with how GNU does it. 2977 */ 2978 static int 2979 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2980 RtldLockState *lockstate) 2981 { 2982 2983 if (obj->ifuncs_resolved) 2984 return (0); 2985 obj->ifuncs_resolved = true; 2986 if (!obj->irelative && !((obj->bind_now || bind_now) && obj->gnu_ifunc)) 2987 return (0); 2988 if (obj_disable_relro(obj) == -1 || 2989 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 2990 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2991 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 2992 obj_enforce_relro(obj) == -1) 2993 return (-1); 2994 return (0); 2995 } 2996 2997 static int 2998 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2999 RtldLockState *lockstate) 3000 { 3001 Objlist_Entry *elm; 3002 Obj_Entry *obj; 3003 3004 STAILQ_FOREACH(elm, list, link) { 3005 obj = elm->obj; 3006 if (obj->marker) 3007 continue; 3008 if (resolve_object_ifunc(obj, bind_now, flags, 3009 lockstate) == -1) 3010 return (-1); 3011 } 3012 return (0); 3013 } 3014 3015 /* 3016 * Cleanup procedure. It will be called (by the atexit mechanism) just 3017 * before the process exits. 3018 */ 3019 static void 3020 rtld_exit(void) 3021 { 3022 RtldLockState lockstate; 3023 3024 wlock_acquire(rtld_bind_lock, &lockstate); 3025 dbg("rtld_exit()"); 3026 objlist_call_fini(&list_fini, NULL, &lockstate); 3027 /* No need to remove the items from the list, since we are exiting. */ 3028 if (!libmap_disable) 3029 lm_fini(); 3030 lock_release(rtld_bind_lock, &lockstate); 3031 } 3032 3033 static void 3034 rtld_nop_exit(void) 3035 { 3036 } 3037 3038 /* 3039 * Iterate over a search path, translate each element, and invoke the 3040 * callback on the result. 3041 */ 3042 static void * 3043 path_enumerate(const char *path, path_enum_proc callback, 3044 const char *refobj_path, void *arg) 3045 { 3046 const char *trans; 3047 if (path == NULL) 3048 return (NULL); 3049 3050 path += strspn(path, ":;"); 3051 while (*path != '\0') { 3052 size_t len; 3053 char *res; 3054 3055 len = strcspn(path, ":;"); 3056 trans = lm_findn(refobj_path, path, len); 3057 if (trans) 3058 res = callback(trans, strlen(trans), arg); 3059 else 3060 res = callback(path, len, arg); 3061 3062 if (res != NULL) 3063 return (res); 3064 3065 path += len; 3066 path += strspn(path, ":;"); 3067 } 3068 3069 return (NULL); 3070 } 3071 3072 struct try_library_args { 3073 const char *name; 3074 size_t namelen; 3075 char *buffer; 3076 size_t buflen; 3077 int fd; 3078 }; 3079 3080 static void * 3081 try_library_path(const char *dir, size_t dirlen, void *param) 3082 { 3083 struct try_library_args *arg; 3084 int fd; 3085 3086 arg = param; 3087 if (*dir == '/' || trust) { 3088 char *pathname; 3089 3090 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3091 return (NULL); 3092 3093 pathname = arg->buffer; 3094 strncpy(pathname, dir, dirlen); 3095 pathname[dirlen] = '/'; 3096 strcpy(pathname + dirlen + 1, arg->name); 3097 3098 dbg(" Trying \"%s\"", pathname); 3099 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3100 if (fd >= 0) { 3101 dbg(" Opened \"%s\", fd %d", pathname, fd); 3102 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3103 strcpy(pathname, arg->buffer); 3104 arg->fd = fd; 3105 return (pathname); 3106 } else { 3107 dbg(" Failed to open \"%s\": %s", 3108 pathname, rtld_strerror(errno)); 3109 } 3110 } 3111 return (NULL); 3112 } 3113 3114 static char * 3115 search_library_path(const char *name, const char *path, 3116 const char *refobj_path, int *fdp) 3117 { 3118 char *p; 3119 struct try_library_args arg; 3120 3121 if (path == NULL) 3122 return NULL; 3123 3124 arg.name = name; 3125 arg.namelen = strlen(name); 3126 arg.buffer = xmalloc(PATH_MAX); 3127 arg.buflen = PATH_MAX; 3128 arg.fd = -1; 3129 3130 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3131 *fdp = arg.fd; 3132 3133 free(arg.buffer); 3134 3135 return (p); 3136 } 3137 3138 3139 /* 3140 * Finds the library with the given name using the directory descriptors 3141 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3142 * 3143 * Returns a freshly-opened close-on-exec file descriptor for the library, 3144 * or -1 if the library cannot be found. 3145 */ 3146 static char * 3147 search_library_pathfds(const char *name, const char *path, int *fdp) 3148 { 3149 char *envcopy, *fdstr, *found, *last_token; 3150 size_t len; 3151 int dirfd, fd; 3152 3153 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3154 3155 /* Don't load from user-specified libdirs into setuid binaries. */ 3156 if (!trust) 3157 return (NULL); 3158 3159 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3160 if (path == NULL) 3161 return (NULL); 3162 3163 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3164 if (name[0] == '/') { 3165 dbg("Absolute path (%s) passed to %s", name, __func__); 3166 return (NULL); 3167 } 3168 3169 /* 3170 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3171 * copy of the path, as strtok_r rewrites separator tokens 3172 * with '\0'. 3173 */ 3174 found = NULL; 3175 envcopy = xstrdup(path); 3176 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3177 fdstr = strtok_r(NULL, ":", &last_token)) { 3178 dirfd = parse_integer(fdstr); 3179 if (dirfd < 0) { 3180 _rtld_error("failed to parse directory FD: '%s'", 3181 fdstr); 3182 break; 3183 } 3184 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3185 if (fd >= 0) { 3186 *fdp = fd; 3187 len = strlen(fdstr) + strlen(name) + 3; 3188 found = xmalloc(len); 3189 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3190 _rtld_error("error generating '%d/%s'", 3191 dirfd, name); 3192 rtld_die(); 3193 } 3194 dbg("open('%s') => %d", found, fd); 3195 break; 3196 } 3197 } 3198 free(envcopy); 3199 3200 return (found); 3201 } 3202 3203 3204 int 3205 dlclose(void *handle) 3206 { 3207 RtldLockState lockstate; 3208 int error; 3209 3210 wlock_acquire(rtld_bind_lock, &lockstate); 3211 error = dlclose_locked(handle, &lockstate); 3212 lock_release(rtld_bind_lock, &lockstate); 3213 return (error); 3214 } 3215 3216 static int 3217 dlclose_locked(void *handle, RtldLockState *lockstate) 3218 { 3219 Obj_Entry *root; 3220 3221 root = dlcheck(handle); 3222 if (root == NULL) 3223 return -1; 3224 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3225 root->path); 3226 3227 /* Unreference the object and its dependencies. */ 3228 root->dl_refcount--; 3229 3230 if (root->refcount == 1) { 3231 /* 3232 * The object will be no longer referenced, so we must unload it. 3233 * First, call the fini functions. 3234 */ 3235 objlist_call_fini(&list_fini, root, lockstate); 3236 3237 unref_dag(root); 3238 3239 /* Finish cleaning up the newly-unreferenced objects. */ 3240 GDB_STATE(RT_DELETE,&root->linkmap); 3241 unload_object(root, lockstate); 3242 GDB_STATE(RT_CONSISTENT,NULL); 3243 } else 3244 unref_dag(root); 3245 3246 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3247 return 0; 3248 } 3249 3250 char * 3251 dlerror(void) 3252 { 3253 char *msg = error_message; 3254 error_message = NULL; 3255 return msg; 3256 } 3257 3258 /* 3259 * This function is deprecated and has no effect. 3260 */ 3261 void 3262 dllockinit(void *context, 3263 void *(*_lock_create)(void *context) __unused, 3264 void (*_rlock_acquire)(void *lock) __unused, 3265 void (*_wlock_acquire)(void *lock) __unused, 3266 void (*_lock_release)(void *lock) __unused, 3267 void (*_lock_destroy)(void *lock) __unused, 3268 void (*context_destroy)(void *context)) 3269 { 3270 static void *cur_context; 3271 static void (*cur_context_destroy)(void *); 3272 3273 /* Just destroy the context from the previous call, if necessary. */ 3274 if (cur_context_destroy != NULL) 3275 cur_context_destroy(cur_context); 3276 cur_context = context; 3277 cur_context_destroy = context_destroy; 3278 } 3279 3280 void * 3281 dlopen(const char *name, int mode) 3282 { 3283 3284 return (rtld_dlopen(name, -1, mode)); 3285 } 3286 3287 void * 3288 fdlopen(int fd, int mode) 3289 { 3290 3291 return (rtld_dlopen(NULL, fd, mode)); 3292 } 3293 3294 static void * 3295 rtld_dlopen(const char *name, int fd, int mode) 3296 { 3297 RtldLockState lockstate; 3298 int lo_flags; 3299 3300 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3301 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3302 if (ld_tracing != NULL) { 3303 rlock_acquire(rtld_bind_lock, &lockstate); 3304 if (sigsetjmp(lockstate.env, 0) != 0) 3305 lock_upgrade(rtld_bind_lock, &lockstate); 3306 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3307 lock_release(rtld_bind_lock, &lockstate); 3308 } 3309 lo_flags = RTLD_LO_DLOPEN; 3310 if (mode & RTLD_NODELETE) 3311 lo_flags |= RTLD_LO_NODELETE; 3312 if (mode & RTLD_NOLOAD) 3313 lo_flags |= RTLD_LO_NOLOAD; 3314 if (ld_tracing != NULL) 3315 lo_flags |= RTLD_LO_TRACE; 3316 3317 return (dlopen_object(name, fd, obj_main, lo_flags, 3318 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3319 } 3320 3321 static void 3322 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3323 { 3324 3325 obj->dl_refcount--; 3326 unref_dag(obj); 3327 if (obj->refcount == 0) 3328 unload_object(obj, lockstate); 3329 } 3330 3331 static Obj_Entry * 3332 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3333 int mode, RtldLockState *lockstate) 3334 { 3335 Obj_Entry *old_obj_tail; 3336 Obj_Entry *obj; 3337 Objlist initlist; 3338 RtldLockState mlockstate; 3339 int result; 3340 3341 objlist_init(&initlist); 3342 3343 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3344 wlock_acquire(rtld_bind_lock, &mlockstate); 3345 lockstate = &mlockstate; 3346 } 3347 GDB_STATE(RT_ADD,NULL); 3348 3349 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3350 obj = NULL; 3351 if (name == NULL && fd == -1) { 3352 obj = obj_main; 3353 obj->refcount++; 3354 } else { 3355 obj = load_object(name, fd, refobj, lo_flags); 3356 } 3357 3358 if (obj) { 3359 obj->dl_refcount++; 3360 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3361 objlist_push_tail(&list_global, obj); 3362 if (globallist_next(old_obj_tail) != NULL) { 3363 /* We loaded something new. */ 3364 assert(globallist_next(old_obj_tail) == obj); 3365 result = 0; 3366 if ((lo_flags & RTLD_LO_EARLY) == 0 && obj->static_tls && 3367 !allocate_tls_offset(obj)) { 3368 _rtld_error("%s: No space available " 3369 "for static Thread Local Storage", obj->path); 3370 result = -1; 3371 } 3372 if (result != -1) 3373 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3374 RTLD_LO_EARLY)); 3375 init_dag(obj); 3376 ref_dag(obj); 3377 if (result != -1) 3378 result = rtld_verify_versions(&obj->dagmembers); 3379 if (result != -1 && ld_tracing) 3380 goto trace; 3381 if (result == -1 || relocate_object_dag(obj, 3382 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3383 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3384 lockstate) == -1) { 3385 dlopen_cleanup(obj, lockstate); 3386 obj = NULL; 3387 } else if (lo_flags & RTLD_LO_EARLY) { 3388 /* 3389 * Do not call the init functions for early loaded 3390 * filtees. The image is still not initialized enough 3391 * for them to work. 3392 * 3393 * Our object is found by the global object list and 3394 * will be ordered among all init calls done right 3395 * before transferring control to main. 3396 */ 3397 } else { 3398 /* Make list of init functions to call. */ 3399 initlist_add_objects(obj, obj, &initlist); 3400 } 3401 /* 3402 * Process all no_delete or global objects here, given 3403 * them own DAGs to prevent their dependencies from being 3404 * unloaded. This has to be done after we have loaded all 3405 * of the dependencies, so that we do not miss any. 3406 */ 3407 if (obj != NULL) 3408 process_z(obj); 3409 } else { 3410 /* 3411 * Bump the reference counts for objects on this DAG. If 3412 * this is the first dlopen() call for the object that was 3413 * already loaded as a dependency, initialize the dag 3414 * starting at it. 3415 */ 3416 init_dag(obj); 3417 ref_dag(obj); 3418 3419 if ((lo_flags & RTLD_LO_TRACE) != 0) 3420 goto trace; 3421 } 3422 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3423 obj->z_nodelete) && !obj->ref_nodel) { 3424 dbg("obj %s nodelete", obj->path); 3425 ref_dag(obj); 3426 obj->z_nodelete = obj->ref_nodel = true; 3427 } 3428 } 3429 3430 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3431 name); 3432 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3433 3434 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3435 map_stacks_exec(lockstate); 3436 if (obj != NULL) 3437 distribute_static_tls(&initlist, lockstate); 3438 } 3439 3440 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3441 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3442 lockstate) == -1) { 3443 objlist_clear(&initlist); 3444 dlopen_cleanup(obj, lockstate); 3445 if (lockstate == &mlockstate) 3446 lock_release(rtld_bind_lock, lockstate); 3447 return (NULL); 3448 } 3449 3450 if (!(lo_flags & RTLD_LO_EARLY)) { 3451 /* Call the init functions. */ 3452 objlist_call_init(&initlist, lockstate); 3453 } 3454 objlist_clear(&initlist); 3455 if (lockstate == &mlockstate) 3456 lock_release(rtld_bind_lock, lockstate); 3457 return obj; 3458 trace: 3459 trace_loaded_objects(obj); 3460 if (lockstate == &mlockstate) 3461 lock_release(rtld_bind_lock, lockstate); 3462 exit(0); 3463 } 3464 3465 static void * 3466 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3467 int flags) 3468 { 3469 DoneList donelist; 3470 const Obj_Entry *obj, *defobj; 3471 const Elf_Sym *def; 3472 SymLook req; 3473 RtldLockState lockstate; 3474 tls_index ti; 3475 void *sym; 3476 int res; 3477 3478 def = NULL; 3479 defobj = NULL; 3480 symlook_init(&req, name); 3481 req.ventry = ve; 3482 req.flags = flags | SYMLOOK_IN_PLT; 3483 req.lockstate = &lockstate; 3484 3485 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3486 rlock_acquire(rtld_bind_lock, &lockstate); 3487 if (sigsetjmp(lockstate.env, 0) != 0) 3488 lock_upgrade(rtld_bind_lock, &lockstate); 3489 if (handle == NULL || handle == RTLD_NEXT || 3490 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3491 3492 if ((obj = obj_from_addr(retaddr)) == NULL) { 3493 _rtld_error("Cannot determine caller's shared object"); 3494 lock_release(rtld_bind_lock, &lockstate); 3495 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3496 return NULL; 3497 } 3498 if (handle == NULL) { /* Just the caller's shared object. */ 3499 res = symlook_obj(&req, obj); 3500 if (res == 0) { 3501 def = req.sym_out; 3502 defobj = req.defobj_out; 3503 } 3504 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3505 handle == RTLD_SELF) { /* ... caller included */ 3506 if (handle == RTLD_NEXT) 3507 obj = globallist_next(obj); 3508 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3509 if (obj->marker) 3510 continue; 3511 res = symlook_obj(&req, obj); 3512 if (res == 0) { 3513 if (def == NULL || 3514 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3515 def = req.sym_out; 3516 defobj = req.defobj_out; 3517 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3518 break; 3519 } 3520 } 3521 } 3522 /* 3523 * Search the dynamic linker itself, and possibly resolve the 3524 * symbol from there. This is how the application links to 3525 * dynamic linker services such as dlopen. 3526 */ 3527 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3528 res = symlook_obj(&req, &obj_rtld); 3529 if (res == 0) { 3530 def = req.sym_out; 3531 defobj = req.defobj_out; 3532 } 3533 } 3534 } else { 3535 assert(handle == RTLD_DEFAULT); 3536 res = symlook_default(&req, obj); 3537 if (res == 0) { 3538 defobj = req.defobj_out; 3539 def = req.sym_out; 3540 } 3541 } 3542 } else { 3543 if ((obj = dlcheck(handle)) == NULL) { 3544 lock_release(rtld_bind_lock, &lockstate); 3545 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3546 return NULL; 3547 } 3548 3549 donelist_init(&donelist); 3550 if (obj->mainprog) { 3551 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3552 res = symlook_global(&req, &donelist); 3553 if (res == 0) { 3554 def = req.sym_out; 3555 defobj = req.defobj_out; 3556 } 3557 /* 3558 * Search the dynamic linker itself, and possibly resolve the 3559 * symbol from there. This is how the application links to 3560 * dynamic linker services such as dlopen. 3561 */ 3562 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3563 res = symlook_obj(&req, &obj_rtld); 3564 if (res == 0) { 3565 def = req.sym_out; 3566 defobj = req.defobj_out; 3567 } 3568 } 3569 } 3570 else { 3571 /* Search the whole DAG rooted at the given object. */ 3572 res = symlook_list(&req, &obj->dagmembers, &donelist); 3573 if (res == 0) { 3574 def = req.sym_out; 3575 defobj = req.defobj_out; 3576 } 3577 } 3578 } 3579 3580 if (def != NULL) { 3581 lock_release(rtld_bind_lock, &lockstate); 3582 3583 /* 3584 * The value required by the caller is derived from the value 3585 * of the symbol. this is simply the relocated value of the 3586 * symbol. 3587 */ 3588 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3589 sym = make_function_pointer(def, defobj); 3590 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3591 sym = rtld_resolve_ifunc(defobj, def); 3592 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3593 ti.ti_module = defobj->tlsindex; 3594 ti.ti_offset = def->st_value; 3595 sym = __tls_get_addr(&ti); 3596 } else 3597 sym = defobj->relocbase + def->st_value; 3598 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3599 return (sym); 3600 } 3601 3602 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3603 ve != NULL ? ve->name : ""); 3604 lock_release(rtld_bind_lock, &lockstate); 3605 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3606 return NULL; 3607 } 3608 3609 void * 3610 dlsym(void *handle, const char *name) 3611 { 3612 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3613 SYMLOOK_DLSYM); 3614 } 3615 3616 dlfunc_t 3617 dlfunc(void *handle, const char *name) 3618 { 3619 union { 3620 void *d; 3621 dlfunc_t f; 3622 } rv; 3623 3624 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3625 SYMLOOK_DLSYM); 3626 return (rv.f); 3627 } 3628 3629 void * 3630 dlvsym(void *handle, const char *name, const char *version) 3631 { 3632 Ver_Entry ventry; 3633 3634 ventry.name = version; 3635 ventry.file = NULL; 3636 ventry.hash = elf_hash(version); 3637 ventry.flags= 0; 3638 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3639 SYMLOOK_DLSYM); 3640 } 3641 3642 int 3643 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3644 { 3645 const Obj_Entry *obj; 3646 RtldLockState lockstate; 3647 3648 rlock_acquire(rtld_bind_lock, &lockstate); 3649 obj = obj_from_addr(addr); 3650 if (obj == NULL) { 3651 _rtld_error("No shared object contains address"); 3652 lock_release(rtld_bind_lock, &lockstate); 3653 return (0); 3654 } 3655 rtld_fill_dl_phdr_info(obj, phdr_info); 3656 lock_release(rtld_bind_lock, &lockstate); 3657 return (1); 3658 } 3659 3660 int 3661 dladdr(const void *addr, Dl_info *info) 3662 { 3663 const Obj_Entry *obj; 3664 const Elf_Sym *def; 3665 void *symbol_addr; 3666 unsigned long symoffset; 3667 RtldLockState lockstate; 3668 3669 rlock_acquire(rtld_bind_lock, &lockstate); 3670 obj = obj_from_addr(addr); 3671 if (obj == NULL) { 3672 _rtld_error("No shared object contains address"); 3673 lock_release(rtld_bind_lock, &lockstate); 3674 return 0; 3675 } 3676 info->dli_fname = obj->path; 3677 info->dli_fbase = obj->mapbase; 3678 info->dli_saddr = (void *)0; 3679 info->dli_sname = NULL; 3680 3681 /* 3682 * Walk the symbol list looking for the symbol whose address is 3683 * closest to the address sent in. 3684 */ 3685 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3686 def = obj->symtab + symoffset; 3687 3688 /* 3689 * For skip the symbol if st_shndx is either SHN_UNDEF or 3690 * SHN_COMMON. 3691 */ 3692 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3693 continue; 3694 3695 /* 3696 * If the symbol is greater than the specified address, or if it 3697 * is further away from addr than the current nearest symbol, 3698 * then reject it. 3699 */ 3700 symbol_addr = obj->relocbase + def->st_value; 3701 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3702 continue; 3703 3704 /* Update our idea of the nearest symbol. */ 3705 info->dli_sname = obj->strtab + def->st_name; 3706 info->dli_saddr = symbol_addr; 3707 3708 /* Exact match? */ 3709 if (info->dli_saddr == addr) 3710 break; 3711 } 3712 lock_release(rtld_bind_lock, &lockstate); 3713 return 1; 3714 } 3715 3716 int 3717 dlinfo(void *handle, int request, void *p) 3718 { 3719 const Obj_Entry *obj; 3720 RtldLockState lockstate; 3721 int error; 3722 3723 rlock_acquire(rtld_bind_lock, &lockstate); 3724 3725 if (handle == NULL || handle == RTLD_SELF) { 3726 void *retaddr; 3727 3728 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3729 if ((obj = obj_from_addr(retaddr)) == NULL) 3730 _rtld_error("Cannot determine caller's shared object"); 3731 } else 3732 obj = dlcheck(handle); 3733 3734 if (obj == NULL) { 3735 lock_release(rtld_bind_lock, &lockstate); 3736 return (-1); 3737 } 3738 3739 error = 0; 3740 switch (request) { 3741 case RTLD_DI_LINKMAP: 3742 *((struct link_map const **)p) = &obj->linkmap; 3743 break; 3744 case RTLD_DI_ORIGIN: 3745 error = rtld_dirname(obj->path, p); 3746 break; 3747 3748 case RTLD_DI_SERINFOSIZE: 3749 case RTLD_DI_SERINFO: 3750 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3751 break; 3752 3753 default: 3754 _rtld_error("Invalid request %d passed to dlinfo()", request); 3755 error = -1; 3756 } 3757 3758 lock_release(rtld_bind_lock, &lockstate); 3759 3760 return (error); 3761 } 3762 3763 static void 3764 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3765 { 3766 3767 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3768 phdr_info->dlpi_name = obj->path; 3769 phdr_info->dlpi_phdr = obj->phdr; 3770 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3771 phdr_info->dlpi_tls_modid = obj->tlsindex; 3772 phdr_info->dlpi_tls_data = obj->tlsinit; 3773 phdr_info->dlpi_adds = obj_loads; 3774 phdr_info->dlpi_subs = obj_loads - obj_count; 3775 } 3776 3777 int 3778 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3779 { 3780 struct dl_phdr_info phdr_info; 3781 Obj_Entry *obj, marker; 3782 RtldLockState bind_lockstate, phdr_lockstate; 3783 int error; 3784 3785 init_marker(&marker); 3786 error = 0; 3787 3788 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3789 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3790 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3791 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3792 rtld_fill_dl_phdr_info(obj, &phdr_info); 3793 hold_object(obj); 3794 lock_release(rtld_bind_lock, &bind_lockstate); 3795 3796 error = callback(&phdr_info, sizeof phdr_info, param); 3797 3798 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3799 unhold_object(obj); 3800 obj = globallist_next(&marker); 3801 TAILQ_REMOVE(&obj_list, &marker, next); 3802 if (error != 0) { 3803 lock_release(rtld_bind_lock, &bind_lockstate); 3804 lock_release(rtld_phdr_lock, &phdr_lockstate); 3805 return (error); 3806 } 3807 } 3808 3809 if (error == 0) { 3810 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3811 lock_release(rtld_bind_lock, &bind_lockstate); 3812 error = callback(&phdr_info, sizeof(phdr_info), param); 3813 } 3814 lock_release(rtld_phdr_lock, &phdr_lockstate); 3815 return (error); 3816 } 3817 3818 static void * 3819 fill_search_info(const char *dir, size_t dirlen, void *param) 3820 { 3821 struct fill_search_info_args *arg; 3822 3823 arg = param; 3824 3825 if (arg->request == RTLD_DI_SERINFOSIZE) { 3826 arg->serinfo->dls_cnt ++; 3827 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3828 } else { 3829 struct dl_serpath *s_entry; 3830 3831 s_entry = arg->serpath; 3832 s_entry->dls_name = arg->strspace; 3833 s_entry->dls_flags = arg->flags; 3834 3835 strncpy(arg->strspace, dir, dirlen); 3836 arg->strspace[dirlen] = '\0'; 3837 3838 arg->strspace += dirlen + 1; 3839 arg->serpath++; 3840 } 3841 3842 return (NULL); 3843 } 3844 3845 static int 3846 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3847 { 3848 struct dl_serinfo _info; 3849 struct fill_search_info_args args; 3850 3851 args.request = RTLD_DI_SERINFOSIZE; 3852 args.serinfo = &_info; 3853 3854 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3855 _info.dls_cnt = 0; 3856 3857 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 3858 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 3859 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 3860 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 3861 if (!obj->z_nodeflib) 3862 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 3863 3864 3865 if (request == RTLD_DI_SERINFOSIZE) { 3866 info->dls_size = _info.dls_size; 3867 info->dls_cnt = _info.dls_cnt; 3868 return (0); 3869 } 3870 3871 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3872 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3873 return (-1); 3874 } 3875 3876 args.request = RTLD_DI_SERINFO; 3877 args.serinfo = info; 3878 args.serpath = &info->dls_serpath[0]; 3879 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3880 3881 args.flags = LA_SER_RUNPATH; 3882 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 3883 return (-1); 3884 3885 args.flags = LA_SER_LIBPATH; 3886 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 3887 return (-1); 3888 3889 args.flags = LA_SER_RUNPATH; 3890 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 3891 return (-1); 3892 3893 args.flags = LA_SER_CONFIG; 3894 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 3895 != NULL) 3896 return (-1); 3897 3898 args.flags = LA_SER_DEFAULT; 3899 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 3900 fill_search_info, NULL, &args) != NULL) 3901 return (-1); 3902 return (0); 3903 } 3904 3905 static int 3906 rtld_dirname(const char *path, char *bname) 3907 { 3908 const char *endp; 3909 3910 /* Empty or NULL string gets treated as "." */ 3911 if (path == NULL || *path == '\0') { 3912 bname[0] = '.'; 3913 bname[1] = '\0'; 3914 return (0); 3915 } 3916 3917 /* Strip trailing slashes */ 3918 endp = path + strlen(path) - 1; 3919 while (endp > path && *endp == '/') 3920 endp--; 3921 3922 /* Find the start of the dir */ 3923 while (endp > path && *endp != '/') 3924 endp--; 3925 3926 /* Either the dir is "/" or there are no slashes */ 3927 if (endp == path) { 3928 bname[0] = *endp == '/' ? '/' : '.'; 3929 bname[1] = '\0'; 3930 return (0); 3931 } else { 3932 do { 3933 endp--; 3934 } while (endp > path && *endp == '/'); 3935 } 3936 3937 if (endp - path + 2 > PATH_MAX) 3938 { 3939 _rtld_error("Filename is too long: %s", path); 3940 return(-1); 3941 } 3942 3943 strncpy(bname, path, endp - path + 1); 3944 bname[endp - path + 1] = '\0'; 3945 return (0); 3946 } 3947 3948 static int 3949 rtld_dirname_abs(const char *path, char *base) 3950 { 3951 char *last; 3952 3953 if (realpath(path, base) == NULL) 3954 return (-1); 3955 dbg("%s -> %s", path, base); 3956 last = strrchr(base, '/'); 3957 if (last == NULL) 3958 return (-1); 3959 if (last != base) 3960 *last = '\0'; 3961 return (0); 3962 } 3963 3964 static void 3965 linkmap_add(Obj_Entry *obj) 3966 { 3967 struct link_map *l = &obj->linkmap; 3968 struct link_map *prev; 3969 3970 obj->linkmap.l_name = obj->path; 3971 obj->linkmap.l_addr = obj->mapbase; 3972 obj->linkmap.l_ld = obj->dynamic; 3973 #ifdef __mips__ 3974 /* GDB needs load offset on MIPS to use the symbols */ 3975 obj->linkmap.l_offs = obj->relocbase; 3976 #endif 3977 3978 if (r_debug.r_map == NULL) { 3979 r_debug.r_map = l; 3980 return; 3981 } 3982 3983 /* 3984 * Scan to the end of the list, but not past the entry for the 3985 * dynamic linker, which we want to keep at the very end. 3986 */ 3987 for (prev = r_debug.r_map; 3988 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3989 prev = prev->l_next) 3990 ; 3991 3992 /* Link in the new entry. */ 3993 l->l_prev = prev; 3994 l->l_next = prev->l_next; 3995 if (l->l_next != NULL) 3996 l->l_next->l_prev = l; 3997 prev->l_next = l; 3998 } 3999 4000 static void 4001 linkmap_delete(Obj_Entry *obj) 4002 { 4003 struct link_map *l = &obj->linkmap; 4004 4005 if (l->l_prev == NULL) { 4006 if ((r_debug.r_map = l->l_next) != NULL) 4007 l->l_next->l_prev = NULL; 4008 return; 4009 } 4010 4011 if ((l->l_prev->l_next = l->l_next) != NULL) 4012 l->l_next->l_prev = l->l_prev; 4013 } 4014 4015 /* 4016 * Function for the debugger to set a breakpoint on to gain control. 4017 * 4018 * The two parameters allow the debugger to easily find and determine 4019 * what the runtime loader is doing and to whom it is doing it. 4020 * 4021 * When the loadhook trap is hit (r_debug_state, set at program 4022 * initialization), the arguments can be found on the stack: 4023 * 4024 * +8 struct link_map *m 4025 * +4 struct r_debug *rd 4026 * +0 RetAddr 4027 */ 4028 void 4029 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4030 { 4031 /* 4032 * The following is a hack to force the compiler to emit calls to 4033 * this function, even when optimizing. If the function is empty, 4034 * the compiler is not obliged to emit any code for calls to it, 4035 * even when marked __noinline. However, gdb depends on those 4036 * calls being made. 4037 */ 4038 __compiler_membar(); 4039 } 4040 4041 /* 4042 * A function called after init routines have completed. This can be used to 4043 * break before a program's entry routine is called, and can be used when 4044 * main is not available in the symbol table. 4045 */ 4046 void 4047 _r_debug_postinit(struct link_map *m __unused) 4048 { 4049 4050 /* See r_debug_state(). */ 4051 __compiler_membar(); 4052 } 4053 4054 static void 4055 release_object(Obj_Entry *obj) 4056 { 4057 4058 if (obj->holdcount > 0) { 4059 obj->unholdfree = true; 4060 return; 4061 } 4062 munmap(obj->mapbase, obj->mapsize); 4063 linkmap_delete(obj); 4064 obj_free(obj); 4065 } 4066 4067 /* 4068 * Get address of the pointer variable in the main program. 4069 * Prefer non-weak symbol over the weak one. 4070 */ 4071 static const void ** 4072 get_program_var_addr(const char *name, RtldLockState *lockstate) 4073 { 4074 SymLook req; 4075 DoneList donelist; 4076 4077 symlook_init(&req, name); 4078 req.lockstate = lockstate; 4079 donelist_init(&donelist); 4080 if (symlook_global(&req, &donelist) != 0) 4081 return (NULL); 4082 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4083 return ((const void **)make_function_pointer(req.sym_out, 4084 req.defobj_out)); 4085 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4086 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4087 else 4088 return ((const void **)(req.defobj_out->relocbase + 4089 req.sym_out->st_value)); 4090 } 4091 4092 /* 4093 * Set a pointer variable in the main program to the given value. This 4094 * is used to set key variables such as "environ" before any of the 4095 * init functions are called. 4096 */ 4097 static void 4098 set_program_var(const char *name, const void *value) 4099 { 4100 const void **addr; 4101 4102 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4103 dbg("\"%s\": *%p <-- %p", name, addr, value); 4104 *addr = value; 4105 } 4106 } 4107 4108 /* 4109 * Search the global objects, including dependencies and main object, 4110 * for the given symbol. 4111 */ 4112 static int 4113 symlook_global(SymLook *req, DoneList *donelist) 4114 { 4115 SymLook req1; 4116 const Objlist_Entry *elm; 4117 int res; 4118 4119 symlook_init_from_req(&req1, req); 4120 4121 /* Search all objects loaded at program start up. */ 4122 if (req->defobj_out == NULL || 4123 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4124 res = symlook_list(&req1, &list_main, donelist); 4125 if (res == 0 && (req->defobj_out == NULL || 4126 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4127 req->sym_out = req1.sym_out; 4128 req->defobj_out = req1.defobj_out; 4129 assert(req->defobj_out != NULL); 4130 } 4131 } 4132 4133 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4134 STAILQ_FOREACH(elm, &list_global, link) { 4135 if (req->defobj_out != NULL && 4136 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4137 break; 4138 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4139 if (res == 0 && (req->defobj_out == NULL || 4140 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4141 req->sym_out = req1.sym_out; 4142 req->defobj_out = req1.defobj_out; 4143 assert(req->defobj_out != NULL); 4144 } 4145 } 4146 4147 return (req->sym_out != NULL ? 0 : ESRCH); 4148 } 4149 4150 /* 4151 * Given a symbol name in a referencing object, find the corresponding 4152 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4153 * no definition was found. Returns a pointer to the Obj_Entry of the 4154 * defining object via the reference parameter DEFOBJ_OUT. 4155 */ 4156 static int 4157 symlook_default(SymLook *req, const Obj_Entry *refobj) 4158 { 4159 DoneList donelist; 4160 const Objlist_Entry *elm; 4161 SymLook req1; 4162 int res; 4163 4164 donelist_init(&donelist); 4165 symlook_init_from_req(&req1, req); 4166 4167 /* 4168 * Look first in the referencing object if linked symbolically, 4169 * and similarly handle protected symbols. 4170 */ 4171 res = symlook_obj(&req1, refobj); 4172 if (res == 0 && (refobj->symbolic || 4173 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4174 req->sym_out = req1.sym_out; 4175 req->defobj_out = req1.defobj_out; 4176 assert(req->defobj_out != NULL); 4177 } 4178 if (refobj->symbolic || req->defobj_out != NULL) 4179 donelist_check(&donelist, refobj); 4180 4181 symlook_global(req, &donelist); 4182 4183 /* Search all dlopened DAGs containing the referencing object. */ 4184 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4185 if (req->sym_out != NULL && 4186 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4187 break; 4188 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4189 if (res == 0 && (req->sym_out == NULL || 4190 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4191 req->sym_out = req1.sym_out; 4192 req->defobj_out = req1.defobj_out; 4193 assert(req->defobj_out != NULL); 4194 } 4195 } 4196 4197 /* 4198 * Search the dynamic linker itself, and possibly resolve the 4199 * symbol from there. This is how the application links to 4200 * dynamic linker services such as dlopen. 4201 */ 4202 if (req->sym_out == NULL || 4203 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4204 res = symlook_obj(&req1, &obj_rtld); 4205 if (res == 0) { 4206 req->sym_out = req1.sym_out; 4207 req->defobj_out = req1.defobj_out; 4208 assert(req->defobj_out != NULL); 4209 } 4210 } 4211 4212 return (req->sym_out != NULL ? 0 : ESRCH); 4213 } 4214 4215 static int 4216 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4217 { 4218 const Elf_Sym *def; 4219 const Obj_Entry *defobj; 4220 const Objlist_Entry *elm; 4221 SymLook req1; 4222 int res; 4223 4224 def = NULL; 4225 defobj = NULL; 4226 STAILQ_FOREACH(elm, objlist, link) { 4227 if (donelist_check(dlp, elm->obj)) 4228 continue; 4229 symlook_init_from_req(&req1, req); 4230 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4231 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4232 def = req1.sym_out; 4233 defobj = req1.defobj_out; 4234 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4235 break; 4236 } 4237 } 4238 } 4239 if (def != NULL) { 4240 req->sym_out = def; 4241 req->defobj_out = defobj; 4242 return (0); 4243 } 4244 return (ESRCH); 4245 } 4246 4247 /* 4248 * Search the chain of DAGS cointed to by the given Needed_Entry 4249 * for a symbol of the given name. Each DAG is scanned completely 4250 * before advancing to the next one. Returns a pointer to the symbol, 4251 * or NULL if no definition was found. 4252 */ 4253 static int 4254 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4255 { 4256 const Elf_Sym *def; 4257 const Needed_Entry *n; 4258 const Obj_Entry *defobj; 4259 SymLook req1; 4260 int res; 4261 4262 def = NULL; 4263 defobj = NULL; 4264 symlook_init_from_req(&req1, req); 4265 for (n = needed; n != NULL; n = n->next) { 4266 if (n->obj == NULL || 4267 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4268 continue; 4269 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4270 def = req1.sym_out; 4271 defobj = req1.defobj_out; 4272 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4273 break; 4274 } 4275 } 4276 if (def != NULL) { 4277 req->sym_out = def; 4278 req->defobj_out = defobj; 4279 return (0); 4280 } 4281 return (ESRCH); 4282 } 4283 4284 /* 4285 * Search the symbol table of a single shared object for a symbol of 4286 * the given name and version, if requested. Returns a pointer to the 4287 * symbol, or NULL if no definition was found. If the object is 4288 * filter, return filtered symbol from filtee. 4289 * 4290 * The symbol's hash value is passed in for efficiency reasons; that 4291 * eliminates many recomputations of the hash value. 4292 */ 4293 int 4294 symlook_obj(SymLook *req, const Obj_Entry *obj) 4295 { 4296 DoneList donelist; 4297 SymLook req1; 4298 int flags, res, mres; 4299 4300 /* 4301 * If there is at least one valid hash at this point, we prefer to 4302 * use the faster GNU version if available. 4303 */ 4304 if (obj->valid_hash_gnu) 4305 mres = symlook_obj1_gnu(req, obj); 4306 else if (obj->valid_hash_sysv) 4307 mres = symlook_obj1_sysv(req, obj); 4308 else 4309 return (EINVAL); 4310 4311 if (mres == 0) { 4312 if (obj->needed_filtees != NULL) { 4313 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4314 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4315 donelist_init(&donelist); 4316 symlook_init_from_req(&req1, req); 4317 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4318 if (res == 0) { 4319 req->sym_out = req1.sym_out; 4320 req->defobj_out = req1.defobj_out; 4321 } 4322 return (res); 4323 } 4324 if (obj->needed_aux_filtees != NULL) { 4325 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4326 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4327 donelist_init(&donelist); 4328 symlook_init_from_req(&req1, req); 4329 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4330 if (res == 0) { 4331 req->sym_out = req1.sym_out; 4332 req->defobj_out = req1.defobj_out; 4333 return (res); 4334 } 4335 } 4336 } 4337 return (mres); 4338 } 4339 4340 /* Symbol match routine common to both hash functions */ 4341 static bool 4342 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4343 const unsigned long symnum) 4344 { 4345 Elf_Versym verndx; 4346 const Elf_Sym *symp; 4347 const char *strp; 4348 4349 symp = obj->symtab + symnum; 4350 strp = obj->strtab + symp->st_name; 4351 4352 switch (ELF_ST_TYPE(symp->st_info)) { 4353 case STT_FUNC: 4354 case STT_NOTYPE: 4355 case STT_OBJECT: 4356 case STT_COMMON: 4357 case STT_GNU_IFUNC: 4358 if (symp->st_value == 0) 4359 return (false); 4360 /* fallthrough */ 4361 case STT_TLS: 4362 if (symp->st_shndx != SHN_UNDEF) 4363 break; 4364 #ifndef __mips__ 4365 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4366 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4367 break; 4368 #endif 4369 /* fallthrough */ 4370 default: 4371 return (false); 4372 } 4373 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4374 return (false); 4375 4376 if (req->ventry == NULL) { 4377 if (obj->versyms != NULL) { 4378 verndx = VER_NDX(obj->versyms[symnum]); 4379 if (verndx > obj->vernum) { 4380 _rtld_error( 4381 "%s: symbol %s references wrong version %d", 4382 obj->path, obj->strtab + symnum, verndx); 4383 return (false); 4384 } 4385 /* 4386 * If we are not called from dlsym (i.e. this 4387 * is a normal relocation from unversioned 4388 * binary), accept the symbol immediately if 4389 * it happens to have first version after this 4390 * shared object became versioned. Otherwise, 4391 * if symbol is versioned and not hidden, 4392 * remember it. If it is the only symbol with 4393 * this name exported by the shared object, it 4394 * will be returned as a match by the calling 4395 * function. If symbol is global (verndx < 2) 4396 * accept it unconditionally. 4397 */ 4398 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4399 verndx == VER_NDX_GIVEN) { 4400 result->sym_out = symp; 4401 return (true); 4402 } 4403 else if (verndx >= VER_NDX_GIVEN) { 4404 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4405 == 0) { 4406 if (result->vsymp == NULL) 4407 result->vsymp = symp; 4408 result->vcount++; 4409 } 4410 return (false); 4411 } 4412 } 4413 result->sym_out = symp; 4414 return (true); 4415 } 4416 if (obj->versyms == NULL) { 4417 if (object_match_name(obj, req->ventry->name)) { 4418 _rtld_error("%s: object %s should provide version %s " 4419 "for symbol %s", obj_rtld.path, obj->path, 4420 req->ventry->name, obj->strtab + symnum); 4421 return (false); 4422 } 4423 } else { 4424 verndx = VER_NDX(obj->versyms[symnum]); 4425 if (verndx > obj->vernum) { 4426 _rtld_error("%s: symbol %s references wrong version %d", 4427 obj->path, obj->strtab + symnum, verndx); 4428 return (false); 4429 } 4430 if (obj->vertab[verndx].hash != req->ventry->hash || 4431 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4432 /* 4433 * Version does not match. Look if this is a 4434 * global symbol and if it is not hidden. If 4435 * global symbol (verndx < 2) is available, 4436 * use it. Do not return symbol if we are 4437 * called by dlvsym, because dlvsym looks for 4438 * a specific version and default one is not 4439 * what dlvsym wants. 4440 */ 4441 if ((req->flags & SYMLOOK_DLSYM) || 4442 (verndx >= VER_NDX_GIVEN) || 4443 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4444 return (false); 4445 } 4446 } 4447 result->sym_out = symp; 4448 return (true); 4449 } 4450 4451 /* 4452 * Search for symbol using SysV hash function. 4453 * obj->buckets is known not to be NULL at this point; the test for this was 4454 * performed with the obj->valid_hash_sysv assignment. 4455 */ 4456 static int 4457 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4458 { 4459 unsigned long symnum; 4460 Sym_Match_Result matchres; 4461 4462 matchres.sym_out = NULL; 4463 matchres.vsymp = NULL; 4464 matchres.vcount = 0; 4465 4466 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4467 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4468 if (symnum >= obj->nchains) 4469 return (ESRCH); /* Bad object */ 4470 4471 if (matched_symbol(req, obj, &matchres, symnum)) { 4472 req->sym_out = matchres.sym_out; 4473 req->defobj_out = obj; 4474 return (0); 4475 } 4476 } 4477 if (matchres.vcount == 1) { 4478 req->sym_out = matchres.vsymp; 4479 req->defobj_out = obj; 4480 return (0); 4481 } 4482 return (ESRCH); 4483 } 4484 4485 /* Search for symbol using GNU hash function */ 4486 static int 4487 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4488 { 4489 Elf_Addr bloom_word; 4490 const Elf32_Word *hashval; 4491 Elf32_Word bucket; 4492 Sym_Match_Result matchres; 4493 unsigned int h1, h2; 4494 unsigned long symnum; 4495 4496 matchres.sym_out = NULL; 4497 matchres.vsymp = NULL; 4498 matchres.vcount = 0; 4499 4500 /* Pick right bitmask word from Bloom filter array */ 4501 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4502 obj->maskwords_bm_gnu]; 4503 4504 /* Calculate modulus word size of gnu hash and its derivative */ 4505 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4506 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4507 4508 /* Filter out the "definitely not in set" queries */ 4509 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4510 return (ESRCH); 4511 4512 /* Locate hash chain and corresponding value element*/ 4513 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4514 if (bucket == 0) 4515 return (ESRCH); 4516 hashval = &obj->chain_zero_gnu[bucket]; 4517 do { 4518 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4519 symnum = hashval - obj->chain_zero_gnu; 4520 if (matched_symbol(req, obj, &matchres, symnum)) { 4521 req->sym_out = matchres.sym_out; 4522 req->defobj_out = obj; 4523 return (0); 4524 } 4525 } 4526 } while ((*hashval++ & 1) == 0); 4527 if (matchres.vcount == 1) { 4528 req->sym_out = matchres.vsymp; 4529 req->defobj_out = obj; 4530 return (0); 4531 } 4532 return (ESRCH); 4533 } 4534 4535 static void 4536 trace_loaded_objects(Obj_Entry *obj) 4537 { 4538 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4539 int c; 4540 4541 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4542 main_local = ""; 4543 4544 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4545 fmt1 = "\t%o => %p (%x)\n"; 4546 4547 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4548 fmt2 = "\t%o (%x)\n"; 4549 4550 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4551 4552 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4553 Needed_Entry *needed; 4554 const char *name, *path; 4555 bool is_lib; 4556 4557 if (obj->marker) 4558 continue; 4559 if (list_containers && obj->needed != NULL) 4560 rtld_printf("%s:\n", obj->path); 4561 for (needed = obj->needed; needed; needed = needed->next) { 4562 if (needed->obj != NULL) { 4563 if (needed->obj->traced && !list_containers) 4564 continue; 4565 needed->obj->traced = true; 4566 path = needed->obj->path; 4567 } else 4568 path = "not found"; 4569 4570 name = obj->strtab + needed->name; 4571 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4572 4573 fmt = is_lib ? fmt1 : fmt2; 4574 while ((c = *fmt++) != '\0') { 4575 switch (c) { 4576 default: 4577 rtld_putchar(c); 4578 continue; 4579 case '\\': 4580 switch (c = *fmt) { 4581 case '\0': 4582 continue; 4583 case 'n': 4584 rtld_putchar('\n'); 4585 break; 4586 case 't': 4587 rtld_putchar('\t'); 4588 break; 4589 } 4590 break; 4591 case '%': 4592 switch (c = *fmt) { 4593 case '\0': 4594 continue; 4595 case '%': 4596 default: 4597 rtld_putchar(c); 4598 break; 4599 case 'A': 4600 rtld_putstr(main_local); 4601 break; 4602 case 'a': 4603 rtld_putstr(obj_main->path); 4604 break; 4605 case 'o': 4606 rtld_putstr(name); 4607 break; 4608 #if 0 4609 case 'm': 4610 rtld_printf("%d", sodp->sod_major); 4611 break; 4612 case 'n': 4613 rtld_printf("%d", sodp->sod_minor); 4614 break; 4615 #endif 4616 case 'p': 4617 rtld_putstr(path); 4618 break; 4619 case 'x': 4620 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4621 0); 4622 break; 4623 } 4624 break; 4625 } 4626 ++fmt; 4627 } 4628 } 4629 } 4630 } 4631 4632 /* 4633 * Unload a dlopened object and its dependencies from memory and from 4634 * our data structures. It is assumed that the DAG rooted in the 4635 * object has already been unreferenced, and that the object has a 4636 * reference count of 0. 4637 */ 4638 static void 4639 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4640 { 4641 Obj_Entry marker, *obj, *next; 4642 4643 assert(root->refcount == 0); 4644 4645 /* 4646 * Pass over the DAG removing unreferenced objects from 4647 * appropriate lists. 4648 */ 4649 unlink_object(root); 4650 4651 /* Unmap all objects that are no longer referenced. */ 4652 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4653 next = TAILQ_NEXT(obj, next); 4654 if (obj->marker || obj->refcount != 0) 4655 continue; 4656 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4657 obj->mapsize, 0, obj->path); 4658 dbg("unloading \"%s\"", obj->path); 4659 /* 4660 * Unlink the object now to prevent new references from 4661 * being acquired while the bind lock is dropped in 4662 * recursive dlclose() invocations. 4663 */ 4664 TAILQ_REMOVE(&obj_list, obj, next); 4665 obj_count--; 4666 4667 if (obj->filtees_loaded) { 4668 if (next != NULL) { 4669 init_marker(&marker); 4670 TAILQ_INSERT_BEFORE(next, &marker, next); 4671 unload_filtees(obj, lockstate); 4672 next = TAILQ_NEXT(&marker, next); 4673 TAILQ_REMOVE(&obj_list, &marker, next); 4674 } else 4675 unload_filtees(obj, lockstate); 4676 } 4677 release_object(obj); 4678 } 4679 } 4680 4681 static void 4682 unlink_object(Obj_Entry *root) 4683 { 4684 Objlist_Entry *elm; 4685 4686 if (root->refcount == 0) { 4687 /* Remove the object from the RTLD_GLOBAL list. */ 4688 objlist_remove(&list_global, root); 4689 4690 /* Remove the object from all objects' DAG lists. */ 4691 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4692 objlist_remove(&elm->obj->dldags, root); 4693 if (elm->obj != root) 4694 unlink_object(elm->obj); 4695 } 4696 } 4697 } 4698 4699 static void 4700 ref_dag(Obj_Entry *root) 4701 { 4702 Objlist_Entry *elm; 4703 4704 assert(root->dag_inited); 4705 STAILQ_FOREACH(elm, &root->dagmembers, link) 4706 elm->obj->refcount++; 4707 } 4708 4709 static void 4710 unref_dag(Obj_Entry *root) 4711 { 4712 Objlist_Entry *elm; 4713 4714 assert(root->dag_inited); 4715 STAILQ_FOREACH(elm, &root->dagmembers, link) 4716 elm->obj->refcount--; 4717 } 4718 4719 /* 4720 * Common code for MD __tls_get_addr(). 4721 */ 4722 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4723 static void * 4724 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4725 { 4726 Elf_Addr *newdtv, *dtv; 4727 RtldLockState lockstate; 4728 int to_copy; 4729 4730 dtv = *dtvp; 4731 /* Check dtv generation in case new modules have arrived */ 4732 if (dtv[0] != tls_dtv_generation) { 4733 wlock_acquire(rtld_bind_lock, &lockstate); 4734 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4735 to_copy = dtv[1]; 4736 if (to_copy > tls_max_index) 4737 to_copy = tls_max_index; 4738 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4739 newdtv[0] = tls_dtv_generation; 4740 newdtv[1] = tls_max_index; 4741 free(dtv); 4742 lock_release(rtld_bind_lock, &lockstate); 4743 dtv = *dtvp = newdtv; 4744 } 4745 4746 /* Dynamically allocate module TLS if necessary */ 4747 if (dtv[index + 1] == 0) { 4748 /* Signal safe, wlock will block out signals. */ 4749 wlock_acquire(rtld_bind_lock, &lockstate); 4750 if (!dtv[index + 1]) 4751 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4752 lock_release(rtld_bind_lock, &lockstate); 4753 } 4754 return ((void *)(dtv[index + 1] + offset)); 4755 } 4756 4757 void * 4758 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4759 { 4760 Elf_Addr *dtv; 4761 4762 dtv = *dtvp; 4763 /* Check dtv generation in case new modules have arrived */ 4764 if (__predict_true(dtv[0] == tls_dtv_generation && 4765 dtv[index + 1] != 0)) 4766 return ((void *)(dtv[index + 1] + offset)); 4767 return (tls_get_addr_slow(dtvp, index, offset)); 4768 } 4769 4770 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4771 defined(__powerpc__) || defined(__riscv) 4772 4773 /* 4774 * Return pointer to allocated TLS block 4775 */ 4776 static void * 4777 get_tls_block_ptr(void *tcb, size_t tcbsize) 4778 { 4779 size_t extra_size, post_size, pre_size, tls_block_size; 4780 size_t tls_init_align; 4781 4782 tls_init_align = MAX(obj_main->tlsalign, 1); 4783 4784 /* Compute fragments sizes. */ 4785 extra_size = tcbsize - TLS_TCB_SIZE; 4786 post_size = calculate_tls_post_size(tls_init_align); 4787 tls_block_size = tcbsize + post_size; 4788 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4789 4790 return ((char *)tcb - pre_size - extra_size); 4791 } 4792 4793 /* 4794 * Allocate Static TLS using the Variant I method. 4795 * 4796 * For details on the layout, see lib/libc/gen/tls.c. 4797 * 4798 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4799 * it is based on tls_last_offset, and TLS offsets here are really TCB 4800 * offsets, whereas libc's tls_static_space is just the executable's static 4801 * TLS segment. 4802 */ 4803 void * 4804 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4805 { 4806 Obj_Entry *obj; 4807 char *tls_block; 4808 Elf_Addr *dtv, **tcb; 4809 Elf_Addr addr; 4810 Elf_Addr i; 4811 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4812 size_t tls_init_align; 4813 4814 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4815 return (oldtcb); 4816 4817 assert(tcbsize >= TLS_TCB_SIZE); 4818 maxalign = MAX(tcbalign, tls_static_max_align); 4819 tls_init_align = MAX(obj_main->tlsalign, 1); 4820 4821 /* Compute fragmets sizes. */ 4822 extra_size = tcbsize - TLS_TCB_SIZE; 4823 post_size = calculate_tls_post_size(tls_init_align); 4824 tls_block_size = tcbsize + post_size; 4825 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4826 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 4827 4828 /* Allocate whole TLS block */ 4829 tls_block = malloc_aligned(tls_block_size, maxalign); 4830 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 4831 4832 if (oldtcb != NULL) { 4833 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 4834 tls_static_space); 4835 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 4836 4837 /* Adjust the DTV. */ 4838 dtv = tcb[0]; 4839 for (i = 0; i < dtv[1]; i++) { 4840 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4841 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4842 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 4843 } 4844 } 4845 } else { 4846 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4847 tcb[0] = dtv; 4848 dtv[0] = tls_dtv_generation; 4849 dtv[1] = tls_max_index; 4850 4851 for (obj = globallist_curr(objs); obj != NULL; 4852 obj = globallist_next(obj)) { 4853 if (obj->tlsoffset > 0) { 4854 addr = (Elf_Addr)tcb + obj->tlsoffset; 4855 if (obj->tlsinitsize > 0) 4856 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4857 if (obj->tlssize > obj->tlsinitsize) 4858 memset((void*)(addr + obj->tlsinitsize), 0, 4859 obj->tlssize - obj->tlsinitsize); 4860 dtv[obj->tlsindex + 1] = addr; 4861 } 4862 } 4863 } 4864 4865 return (tcb); 4866 } 4867 4868 void 4869 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 4870 { 4871 Elf_Addr *dtv; 4872 Elf_Addr tlsstart, tlsend; 4873 size_t post_size; 4874 size_t dtvsize, i, tls_init_align; 4875 4876 assert(tcbsize >= TLS_TCB_SIZE); 4877 tls_init_align = MAX(obj_main->tlsalign, 1); 4878 4879 /* Compute fragments sizes. */ 4880 post_size = calculate_tls_post_size(tls_init_align); 4881 4882 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 4883 tlsend = (Elf_Addr)tcb + tls_static_space; 4884 4885 dtv = *(Elf_Addr **)tcb; 4886 dtvsize = dtv[1]; 4887 for (i = 0; i < dtvsize; i++) { 4888 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4889 free((void*)dtv[i+2]); 4890 } 4891 } 4892 free(dtv); 4893 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 4894 } 4895 4896 #endif 4897 4898 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4899 4900 /* 4901 * Allocate Static TLS using the Variant II method. 4902 */ 4903 void * 4904 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4905 { 4906 Obj_Entry *obj; 4907 size_t size, ralign; 4908 char *tls; 4909 Elf_Addr *dtv, *olddtv; 4910 Elf_Addr segbase, oldsegbase, addr; 4911 size_t i; 4912 4913 ralign = tcbalign; 4914 if (tls_static_max_align > ralign) 4915 ralign = tls_static_max_align; 4916 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4917 4918 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4919 tls = malloc_aligned(size, ralign); 4920 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4921 4922 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4923 ((Elf_Addr*)segbase)[0] = segbase; 4924 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4925 4926 dtv[0] = tls_dtv_generation; 4927 dtv[1] = tls_max_index; 4928 4929 if (oldtls) { 4930 /* 4931 * Copy the static TLS block over whole. 4932 */ 4933 oldsegbase = (Elf_Addr) oldtls; 4934 memcpy((void *)(segbase - tls_static_space), 4935 (const void *)(oldsegbase - tls_static_space), 4936 tls_static_space); 4937 4938 /* 4939 * If any dynamic TLS blocks have been created tls_get_addr(), 4940 * move them over. 4941 */ 4942 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4943 for (i = 0; i < olddtv[1]; i++) { 4944 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4945 dtv[i+2] = olddtv[i+2]; 4946 olddtv[i+2] = 0; 4947 } 4948 } 4949 4950 /* 4951 * We assume that this block was the one we created with 4952 * allocate_initial_tls(). 4953 */ 4954 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4955 } else { 4956 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4957 if (obj->marker || obj->tlsoffset == 0) 4958 continue; 4959 addr = segbase - obj->tlsoffset; 4960 memset((void*)(addr + obj->tlsinitsize), 4961 0, obj->tlssize - obj->tlsinitsize); 4962 if (obj->tlsinit) { 4963 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4964 obj->static_tls_copied = true; 4965 } 4966 dtv[obj->tlsindex + 1] = addr; 4967 } 4968 } 4969 4970 return (void*) segbase; 4971 } 4972 4973 void 4974 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 4975 { 4976 Elf_Addr* dtv; 4977 size_t size, ralign; 4978 int dtvsize, i; 4979 Elf_Addr tlsstart, tlsend; 4980 4981 /* 4982 * Figure out the size of the initial TLS block so that we can 4983 * find stuff which ___tls_get_addr() allocated dynamically. 4984 */ 4985 ralign = tcbalign; 4986 if (tls_static_max_align > ralign) 4987 ralign = tls_static_max_align; 4988 size = round(tls_static_space, ralign); 4989 4990 dtv = ((Elf_Addr**)tls)[1]; 4991 dtvsize = dtv[1]; 4992 tlsend = (Elf_Addr) tls; 4993 tlsstart = tlsend - size; 4994 for (i = 0; i < dtvsize; i++) { 4995 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4996 free_aligned((void *)dtv[i + 2]); 4997 } 4998 } 4999 5000 free_aligned((void *)tlsstart); 5001 free((void*) dtv); 5002 } 5003 5004 #endif 5005 5006 /* 5007 * Allocate TLS block for module with given index. 5008 */ 5009 void * 5010 allocate_module_tls(int index) 5011 { 5012 Obj_Entry* obj; 5013 char* p; 5014 5015 TAILQ_FOREACH(obj, &obj_list, next) { 5016 if (obj->marker) 5017 continue; 5018 if (obj->tlsindex == index) 5019 break; 5020 } 5021 if (!obj) { 5022 _rtld_error("Can't find module with TLS index %d", index); 5023 rtld_die(); 5024 } 5025 5026 p = malloc_aligned(obj->tlssize, obj->tlsalign); 5027 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5028 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5029 5030 return p; 5031 } 5032 5033 bool 5034 allocate_tls_offset(Obj_Entry *obj) 5035 { 5036 size_t off; 5037 5038 if (obj->tls_done) 5039 return true; 5040 5041 if (obj->tlssize == 0) { 5042 obj->tls_done = true; 5043 return true; 5044 } 5045 5046 if (tls_last_offset == 0) 5047 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 5048 else 5049 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5050 obj->tlssize, obj->tlsalign); 5051 5052 /* 5053 * If we have already fixed the size of the static TLS block, we 5054 * must stay within that size. When allocating the static TLS, we 5055 * leave a small amount of space spare to be used for dynamically 5056 * loading modules which use static TLS. 5057 */ 5058 if (tls_static_space != 0) { 5059 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 5060 return false; 5061 } else if (obj->tlsalign > tls_static_max_align) { 5062 tls_static_max_align = obj->tlsalign; 5063 } 5064 5065 tls_last_offset = obj->tlsoffset = off; 5066 tls_last_size = obj->tlssize; 5067 obj->tls_done = true; 5068 5069 return true; 5070 } 5071 5072 void 5073 free_tls_offset(Obj_Entry *obj) 5074 { 5075 5076 /* 5077 * If we were the last thing to allocate out of the static TLS 5078 * block, we give our space back to the 'allocator'. This is a 5079 * simplistic workaround to allow libGL.so.1 to be loaded and 5080 * unloaded multiple times. 5081 */ 5082 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5083 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5084 tls_last_offset -= obj->tlssize; 5085 tls_last_size = 0; 5086 } 5087 } 5088 5089 void * 5090 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5091 { 5092 void *ret; 5093 RtldLockState lockstate; 5094 5095 wlock_acquire(rtld_bind_lock, &lockstate); 5096 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5097 tcbsize, tcbalign); 5098 lock_release(rtld_bind_lock, &lockstate); 5099 return (ret); 5100 } 5101 5102 void 5103 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5104 { 5105 RtldLockState lockstate; 5106 5107 wlock_acquire(rtld_bind_lock, &lockstate); 5108 free_tls(tcb, tcbsize, tcbalign); 5109 lock_release(rtld_bind_lock, &lockstate); 5110 } 5111 5112 static void 5113 object_add_name(Obj_Entry *obj, const char *name) 5114 { 5115 Name_Entry *entry; 5116 size_t len; 5117 5118 len = strlen(name); 5119 entry = malloc(sizeof(Name_Entry) + len); 5120 5121 if (entry != NULL) { 5122 strcpy(entry->name, name); 5123 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5124 } 5125 } 5126 5127 static int 5128 object_match_name(const Obj_Entry *obj, const char *name) 5129 { 5130 Name_Entry *entry; 5131 5132 STAILQ_FOREACH(entry, &obj->names, link) { 5133 if (strcmp(name, entry->name) == 0) 5134 return (1); 5135 } 5136 return (0); 5137 } 5138 5139 static Obj_Entry * 5140 locate_dependency(const Obj_Entry *obj, const char *name) 5141 { 5142 const Objlist_Entry *entry; 5143 const Needed_Entry *needed; 5144 5145 STAILQ_FOREACH(entry, &list_main, link) { 5146 if (object_match_name(entry->obj, name)) 5147 return entry->obj; 5148 } 5149 5150 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5151 if (strcmp(obj->strtab + needed->name, name) == 0 || 5152 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5153 /* 5154 * If there is DT_NEEDED for the name we are looking for, 5155 * we are all set. Note that object might not be found if 5156 * dependency was not loaded yet, so the function can 5157 * return NULL here. This is expected and handled 5158 * properly by the caller. 5159 */ 5160 return (needed->obj); 5161 } 5162 } 5163 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5164 obj->path, name); 5165 rtld_die(); 5166 } 5167 5168 static int 5169 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5170 const Elf_Vernaux *vna) 5171 { 5172 const Elf_Verdef *vd; 5173 const char *vername; 5174 5175 vername = refobj->strtab + vna->vna_name; 5176 vd = depobj->verdef; 5177 if (vd == NULL) { 5178 _rtld_error("%s: version %s required by %s not defined", 5179 depobj->path, vername, refobj->path); 5180 return (-1); 5181 } 5182 for (;;) { 5183 if (vd->vd_version != VER_DEF_CURRENT) { 5184 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5185 depobj->path, vd->vd_version); 5186 return (-1); 5187 } 5188 if (vna->vna_hash == vd->vd_hash) { 5189 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5190 ((const char *)vd + vd->vd_aux); 5191 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5192 return (0); 5193 } 5194 if (vd->vd_next == 0) 5195 break; 5196 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5197 } 5198 if (vna->vna_flags & VER_FLG_WEAK) 5199 return (0); 5200 _rtld_error("%s: version %s required by %s not found", 5201 depobj->path, vername, refobj->path); 5202 return (-1); 5203 } 5204 5205 static int 5206 rtld_verify_object_versions(Obj_Entry *obj) 5207 { 5208 const Elf_Verneed *vn; 5209 const Elf_Verdef *vd; 5210 const Elf_Verdaux *vda; 5211 const Elf_Vernaux *vna; 5212 const Obj_Entry *depobj; 5213 int maxvernum, vernum; 5214 5215 if (obj->ver_checked) 5216 return (0); 5217 obj->ver_checked = true; 5218 5219 maxvernum = 0; 5220 /* 5221 * Walk over defined and required version records and figure out 5222 * max index used by any of them. Do very basic sanity checking 5223 * while there. 5224 */ 5225 vn = obj->verneed; 5226 while (vn != NULL) { 5227 if (vn->vn_version != VER_NEED_CURRENT) { 5228 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5229 obj->path, vn->vn_version); 5230 return (-1); 5231 } 5232 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5233 for (;;) { 5234 vernum = VER_NEED_IDX(vna->vna_other); 5235 if (vernum > maxvernum) 5236 maxvernum = vernum; 5237 if (vna->vna_next == 0) 5238 break; 5239 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5240 } 5241 if (vn->vn_next == 0) 5242 break; 5243 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5244 } 5245 5246 vd = obj->verdef; 5247 while (vd != NULL) { 5248 if (vd->vd_version != VER_DEF_CURRENT) { 5249 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5250 obj->path, vd->vd_version); 5251 return (-1); 5252 } 5253 vernum = VER_DEF_IDX(vd->vd_ndx); 5254 if (vernum > maxvernum) 5255 maxvernum = vernum; 5256 if (vd->vd_next == 0) 5257 break; 5258 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5259 } 5260 5261 if (maxvernum == 0) 5262 return (0); 5263 5264 /* 5265 * Store version information in array indexable by version index. 5266 * Verify that object version requirements are satisfied along the 5267 * way. 5268 */ 5269 obj->vernum = maxvernum + 1; 5270 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5271 5272 vd = obj->verdef; 5273 while (vd != NULL) { 5274 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5275 vernum = VER_DEF_IDX(vd->vd_ndx); 5276 assert(vernum <= maxvernum); 5277 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5278 obj->vertab[vernum].hash = vd->vd_hash; 5279 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5280 obj->vertab[vernum].file = NULL; 5281 obj->vertab[vernum].flags = 0; 5282 } 5283 if (vd->vd_next == 0) 5284 break; 5285 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5286 } 5287 5288 vn = obj->verneed; 5289 while (vn != NULL) { 5290 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5291 if (depobj == NULL) 5292 return (-1); 5293 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5294 for (;;) { 5295 if (check_object_provided_version(obj, depobj, vna)) 5296 return (-1); 5297 vernum = VER_NEED_IDX(vna->vna_other); 5298 assert(vernum <= maxvernum); 5299 obj->vertab[vernum].hash = vna->vna_hash; 5300 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5301 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5302 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5303 VER_INFO_HIDDEN : 0; 5304 if (vna->vna_next == 0) 5305 break; 5306 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5307 } 5308 if (vn->vn_next == 0) 5309 break; 5310 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5311 } 5312 return 0; 5313 } 5314 5315 static int 5316 rtld_verify_versions(const Objlist *objlist) 5317 { 5318 Objlist_Entry *entry; 5319 int rc; 5320 5321 rc = 0; 5322 STAILQ_FOREACH(entry, objlist, link) { 5323 /* 5324 * Skip dummy objects or objects that have their version requirements 5325 * already checked. 5326 */ 5327 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5328 continue; 5329 if (rtld_verify_object_versions(entry->obj) == -1) { 5330 rc = -1; 5331 if (ld_tracing == NULL) 5332 break; 5333 } 5334 } 5335 if (rc == 0 || ld_tracing != NULL) 5336 rc = rtld_verify_object_versions(&obj_rtld); 5337 return rc; 5338 } 5339 5340 const Ver_Entry * 5341 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5342 { 5343 Elf_Versym vernum; 5344 5345 if (obj->vertab) { 5346 vernum = VER_NDX(obj->versyms[symnum]); 5347 if (vernum >= obj->vernum) { 5348 _rtld_error("%s: symbol %s has wrong verneed value %d", 5349 obj->path, obj->strtab + symnum, vernum); 5350 } else if (obj->vertab[vernum].hash != 0) { 5351 return &obj->vertab[vernum]; 5352 } 5353 } 5354 return NULL; 5355 } 5356 5357 int 5358 _rtld_get_stack_prot(void) 5359 { 5360 5361 return (stack_prot); 5362 } 5363 5364 int 5365 _rtld_is_dlopened(void *arg) 5366 { 5367 Obj_Entry *obj; 5368 RtldLockState lockstate; 5369 int res; 5370 5371 rlock_acquire(rtld_bind_lock, &lockstate); 5372 obj = dlcheck(arg); 5373 if (obj == NULL) 5374 obj = obj_from_addr(arg); 5375 if (obj == NULL) { 5376 _rtld_error("No shared object contains address"); 5377 lock_release(rtld_bind_lock, &lockstate); 5378 return (-1); 5379 } 5380 res = obj->dlopened ? 1 : 0; 5381 lock_release(rtld_bind_lock, &lockstate); 5382 return (res); 5383 } 5384 5385 static int 5386 obj_remap_relro(Obj_Entry *obj, int prot) 5387 { 5388 5389 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5390 prot) == -1) { 5391 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5392 obj->path, prot, rtld_strerror(errno)); 5393 return (-1); 5394 } 5395 return (0); 5396 } 5397 5398 static int 5399 obj_disable_relro(Obj_Entry *obj) 5400 { 5401 5402 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5403 } 5404 5405 static int 5406 obj_enforce_relro(Obj_Entry *obj) 5407 { 5408 5409 return (obj_remap_relro(obj, PROT_READ)); 5410 } 5411 5412 static void 5413 map_stacks_exec(RtldLockState *lockstate) 5414 { 5415 void (*thr_map_stacks_exec)(void); 5416 5417 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5418 return; 5419 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5420 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5421 if (thr_map_stacks_exec != NULL) { 5422 stack_prot |= PROT_EXEC; 5423 thr_map_stacks_exec(); 5424 } 5425 } 5426 5427 static void 5428 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5429 { 5430 Objlist_Entry *elm; 5431 Obj_Entry *obj; 5432 void (*distrib)(size_t, void *, size_t, size_t); 5433 5434 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5435 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5436 if (distrib == NULL) 5437 return; 5438 STAILQ_FOREACH(elm, list, link) { 5439 obj = elm->obj; 5440 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5441 continue; 5442 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5443 obj->tlssize); 5444 obj->static_tls_copied = true; 5445 } 5446 } 5447 5448 void 5449 symlook_init(SymLook *dst, const char *name) 5450 { 5451 5452 bzero(dst, sizeof(*dst)); 5453 dst->name = name; 5454 dst->hash = elf_hash(name); 5455 dst->hash_gnu = gnu_hash(name); 5456 } 5457 5458 static void 5459 symlook_init_from_req(SymLook *dst, const SymLook *src) 5460 { 5461 5462 dst->name = src->name; 5463 dst->hash = src->hash; 5464 dst->hash_gnu = src->hash_gnu; 5465 dst->ventry = src->ventry; 5466 dst->flags = src->flags; 5467 dst->defobj_out = NULL; 5468 dst->sym_out = NULL; 5469 dst->lockstate = src->lockstate; 5470 } 5471 5472 static int 5473 open_binary_fd(const char *argv0, bool search_in_path) 5474 { 5475 char *pathenv, *pe, binpath[PATH_MAX]; 5476 int fd; 5477 5478 if (search_in_path && strchr(argv0, '/') == NULL) { 5479 pathenv = getenv("PATH"); 5480 if (pathenv == NULL) { 5481 _rtld_error("-p and no PATH environment variable"); 5482 rtld_die(); 5483 } 5484 pathenv = strdup(pathenv); 5485 if (pathenv == NULL) { 5486 _rtld_error("Cannot allocate memory"); 5487 rtld_die(); 5488 } 5489 fd = -1; 5490 errno = ENOENT; 5491 while ((pe = strsep(&pathenv, ":")) != NULL) { 5492 if (strlcpy(binpath, pe, sizeof(binpath)) >= 5493 sizeof(binpath)) 5494 continue; 5495 if (binpath[0] != '\0' && 5496 strlcat(binpath, "/", sizeof(binpath)) >= 5497 sizeof(binpath)) 5498 continue; 5499 if (strlcat(binpath, argv0, sizeof(binpath)) >= 5500 sizeof(binpath)) 5501 continue; 5502 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5503 if (fd != -1 || errno != ENOENT) 5504 break; 5505 } 5506 free(pathenv); 5507 } else { 5508 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5509 } 5510 5511 if (fd == -1) { 5512 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5513 rtld_die(); 5514 } 5515 return (fd); 5516 } 5517 5518 /* 5519 * Parse a set of command-line arguments. 5520 */ 5521 static int 5522 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp) 5523 { 5524 const char *arg; 5525 int fd, i, j, arglen; 5526 char opt; 5527 5528 dbg("Parsing command-line arguments"); 5529 *use_pathp = false; 5530 *fdp = -1; 5531 5532 for (i = 1; i < argc; i++ ) { 5533 arg = argv[i]; 5534 dbg("argv[%d]: '%s'", i, arg); 5535 5536 /* 5537 * rtld arguments end with an explicit "--" or with the first 5538 * non-prefixed argument. 5539 */ 5540 if (strcmp(arg, "--") == 0) { 5541 i++; 5542 break; 5543 } 5544 if (arg[0] != '-') 5545 break; 5546 5547 /* 5548 * All other arguments are single-character options that can 5549 * be combined, so we need to search through `arg` for them. 5550 */ 5551 arglen = strlen(arg); 5552 for (j = 1; j < arglen; j++) { 5553 opt = arg[j]; 5554 if (opt == 'h') { 5555 print_usage(argv[0]); 5556 _exit(0); 5557 } else if (opt == 'f') { 5558 /* 5559 * -f XX can be used to specify a descriptor for the 5560 * binary named at the command line (i.e., the later 5561 * argument will specify the process name but the 5562 * descriptor is what will actually be executed) 5563 */ 5564 if (j != arglen - 1) { 5565 /* -f must be the last option in, e.g., -abcf */ 5566 _rtld_error("Invalid options: %s", arg); 5567 rtld_die(); 5568 } 5569 i++; 5570 fd = parse_integer(argv[i]); 5571 if (fd == -1) { 5572 _rtld_error("Invalid file descriptor: '%s'", 5573 argv[i]); 5574 rtld_die(); 5575 } 5576 *fdp = fd; 5577 break; 5578 } else if (opt == 'p') { 5579 *use_pathp = true; 5580 } else { 5581 _rtld_error("Invalid argument: '%s'", arg); 5582 print_usage(argv[0]); 5583 rtld_die(); 5584 } 5585 } 5586 } 5587 5588 return (i); 5589 } 5590 5591 /* 5592 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5593 */ 5594 static int 5595 parse_integer(const char *str) 5596 { 5597 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5598 const char *orig; 5599 int n; 5600 char c; 5601 5602 orig = str; 5603 n = 0; 5604 for (c = *str; c != '\0'; c = *++str) { 5605 if (c < '0' || c > '9') 5606 return (-1); 5607 5608 n *= RADIX; 5609 n += c - '0'; 5610 } 5611 5612 /* Make sure we actually parsed something. */ 5613 if (str == orig) 5614 return (-1); 5615 return (n); 5616 } 5617 5618 static void 5619 print_usage(const char *argv0) 5620 { 5621 5622 rtld_printf("Usage: %s [-h] [-f <FD>] [--] <binary> [<args>]\n" 5623 "\n" 5624 "Options:\n" 5625 " -h Display this help message\n" 5626 " -p Search in PATH for named binary\n" 5627 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5628 " -- End of RTLD options\n" 5629 " <binary> Name of process to execute\n" 5630 " <args> Arguments to the executed process\n", argv0); 5631 } 5632 5633 /* 5634 * Overrides for libc_pic-provided functions. 5635 */ 5636 5637 int 5638 __getosreldate(void) 5639 { 5640 size_t len; 5641 int oid[2]; 5642 int error, osrel; 5643 5644 if (osreldate != 0) 5645 return (osreldate); 5646 5647 oid[0] = CTL_KERN; 5648 oid[1] = KERN_OSRELDATE; 5649 osrel = 0; 5650 len = sizeof(osrel); 5651 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5652 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5653 osreldate = osrel; 5654 return (osreldate); 5655 } 5656 const char * 5657 rtld_strerror(int errnum) 5658 { 5659 5660 if (errnum < 0 || errnum >= sys_nerr) 5661 return ("Unknown error"); 5662 return (sys_errlist[errnum]); 5663 } 5664 5665 /* 5666 * No ifunc relocations. 5667 */ 5668 void * 5669 memset(void *dest, int c, size_t len) 5670 { 5671 size_t i; 5672 5673 for (i = 0; i < len; i++) 5674 ((char *)dest)[i] = c; 5675 return (dest); 5676 } 5677 5678 void 5679 bzero(void *dest, size_t len) 5680 { 5681 size_t i; 5682 5683 for (i = 0; i < len; i++) 5684 ((char *)dest)[i] = 0; 5685 } 5686 5687 /* malloc */ 5688 void * 5689 malloc(size_t nbytes) 5690 { 5691 5692 return (__crt_malloc(nbytes)); 5693 } 5694 5695 void * 5696 calloc(size_t num, size_t size) 5697 { 5698 5699 return (__crt_calloc(num, size)); 5700 } 5701 5702 void 5703 free(void *cp) 5704 { 5705 5706 __crt_free(cp); 5707 } 5708 5709 void * 5710 realloc(void *cp, size_t nbytes) 5711 { 5712 5713 return (__crt_realloc(cp, nbytes)); 5714 } 5715